* 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin: (57 commits)
fs: scale mntget/mntput
fs: rename vfsmount counter helpers
fs: implement faster dentry memcmp
fs: prefetch inode data in dcache lookup
fs: improve scalability of pseudo filesystems
fs: dcache per-inode inode alias locking
fs: dcache per-bucket dcache hash locking
bit_spinlock: add required includes
kernel: add bl_list
xfs: provide simple rcu-walk ACL implementation
btrfs: provide simple rcu-walk ACL implementation
ext2,3,4: provide simple rcu-walk ACL implementation
fs: provide simple rcu-walk generic_check_acl implementation
fs: provide rcu-walk aware permission i_ops
fs: rcu-walk aware d_revalidate method
fs: cache optimise dentry and inode for rcu-walk
fs: dcache reduce branches in lookup path
fs: dcache remove d_mounted
fs: fs_struct use seqlock
fs: rcu-walk for path lookup
...
--------------------------- dentry_operations --------------------------
prototypes:
- int (*d_revalidate)(struct dentry *, int);
- int (*d_hash) (struct dentry *, struct qstr *);
- int (*d_compare) (struct dentry *, struct qstr *, struct qstr *);
+ int (*d_revalidate)(struct dentry *, struct nameidata *);
+ int (*d_hash)(const struct dentry *, const struct inode *,
+ struct qstr *);
+ int (*d_compare)(const struct dentry *, const struct inode *,
+ const struct dentry *, const struct inode *,
+ unsigned int, const char *, const struct qstr *);
int (*d_delete)(struct dentry *);
void (*d_release)(struct dentry *);
void (*d_iput)(struct dentry *, struct inode *);
char *(*d_dname)((struct dentry *dentry, char *buffer, int buflen);
locking rules:
- dcache_lock rename_lock ->d_lock may block
-d_revalidate: no no no yes
-d_hash no no no yes
-d_compare: no yes no no
-d_delete: yes no yes no
-d_release: no no no yes
-d_iput: no no no yes
+ rename_lock ->d_lock may block rcu-walk
+d_revalidate: no no yes (ref-walk) maybe
+d_hash no no no maybe
+d_compare: yes no no maybe
+d_delete: no yes no no
+d_release: no no yes no
+d_iput: no no yes no
d_dname: no no no no
--------------------------- inode_operations ---------------------------
void * (*follow_link) (struct dentry *, struct nameidata *);
void (*put_link) (struct dentry *, struct nameidata *, void *);
void (*truncate) (struct inode *);
- int (*permission) (struct inode *, int, struct nameidata *);
- int (*check_acl)(struct inode *, int);
+ int (*permission) (struct inode *, int, unsigned int);
+ int (*check_acl)(struct inode *, int, unsigned int);
int (*setattr) (struct dentry *, struct iattr *);
int (*getattr) (struct vfsmount *, struct dentry *, struct kstat *);
int (*setxattr) (struct dentry *, const char *,const void *,size_t,int);
put_link: no
truncate: yes (see below)
setattr: yes
-permission: no
+permission: no (may not block if called in rcu-walk mode)
check_acl: no
getattr: no
setxattr: yes
+++ /dev/null
-RCU-based dcache locking model
-==============================
-
-On many workloads, the most common operation on dcache is to look up a
-dentry, given a parent dentry and the name of the child. Typically,
-for every open(), stat() etc., the dentry corresponding to the
-pathname will be looked up by walking the tree starting with the first
-component of the pathname and using that dentry along with the next
-component to look up the next level and so on. Since it is a frequent
-operation for workloads like multiuser environments and web servers,
-it is important to optimize this path.
-
-Prior to 2.5.10, dcache_lock was acquired in d_lookup and thus in
-every component during path look-up. Since 2.5.10 onwards, fast-walk
-algorithm changed this by holding the dcache_lock at the beginning and
-walking as many cached path component dentries as possible. This
-significantly decreases the number of acquisition of
-dcache_lock. However it also increases the lock hold time
-significantly and affects performance in large SMP machines. Since
-2.5.62 kernel, dcache has been using a new locking model that uses RCU
-to make dcache look-up lock-free.
-
-The current dcache locking model is not very different from the
-existing dcache locking model. Prior to 2.5.62 kernel, dcache_lock
-protected the hash chain, d_child, d_alias, d_lru lists as well as
-d_inode and several other things like mount look-up. RCU-based changes
-affect only the way the hash chain is protected. For everything else
-the dcache_lock must be taken for both traversing as well as
-updating. The hash chain updates too take the dcache_lock. The
-significant change is the way d_lookup traverses the hash chain, it
-doesn't acquire the dcache_lock for this and rely on RCU to ensure
-that the dentry has not been *freed*.
-
-
-Dcache locking details
-======================
-
-For many multi-user workloads, open() and stat() on files are very
-frequently occurring operations. Both involve walking of path names to
-find the dentry corresponding to the concerned file. In 2.4 kernel,
-dcache_lock was held during look-up of each path component. Contention
-and cache-line bouncing of this global lock caused significant
-scalability problems. With the introduction of RCU in Linux kernel,
-this was worked around by making the look-up of path components during
-path walking lock-free.
-
-
-Safe lock-free look-up of dcache hash table
-===========================================
-
-Dcache is a complex data structure with the hash table entries also
-linked together in other lists. In 2.4 kernel, dcache_lock protected
-all the lists. We applied RCU only on hash chain walking. The rest of
-the lists are still protected by dcache_lock. Some of the important
-changes are :
-
-1. The deletion from hash chain is done using hlist_del_rcu() macro
- which doesn't initialize next pointer of the deleted dentry and
- this allows us to walk safely lock-free while a deletion is
- happening.
-
-2. Insertion of a dentry into the hash table is done using
- hlist_add_head_rcu() which take care of ordering the writes - the
- writes to the dentry must be visible before the dentry is
- inserted. This works in conjunction with hlist_for_each_rcu(),
- which has since been replaced by hlist_for_each_entry_rcu(), while
- walking the hash chain. The only requirement is that all
- initialization to the dentry must be done before
- hlist_add_head_rcu() since we don't have dcache_lock protection
- while traversing the hash chain. This isn't different from the
- existing code.
-
-3. The dentry looked up without holding dcache_lock by cannot be
- returned for walking if it is unhashed. It then may have a NULL
- d_inode or other bogosity since RCU doesn't protect the other
- fields in the dentry. We therefore use a flag DCACHE_UNHASHED to
- indicate unhashed dentries and use this in conjunction with a
- per-dentry lock (d_lock). Once looked up without the dcache_lock,
- we acquire the per-dentry lock (d_lock) and check if the dentry is
- unhashed. If so, the look-up is failed. If not, the reference count
- of the dentry is increased and the dentry is returned.
-
-4. Once a dentry is looked up, it must be ensured during the path walk
- for that component it doesn't go away. In pre-2.5.10 code, this was
- done holding a reference to the dentry. dcache_rcu does the same.
- In some sense, dcache_rcu path walking looks like the pre-2.5.10
- version.
-
-5. All dentry hash chain updates must take the dcache_lock as well as
- the per-dentry lock in that order. dput() does this to ensure that
- a dentry that has just been looked up in another CPU doesn't get
- deleted before dget() can be done on it.
-
-6. There are several ways to do reference counting of RCU protected
- objects. One such example is in ipv4 route cache where deferred
- freeing (using call_rcu()) is done as soon as the reference count
- goes to zero. This cannot be done in the case of dentries because
- tearing down of dentries require blocking (dentry_iput()) which
- isn't supported from RCU callbacks. Instead, tearing down of
- dentries happen synchronously in dput(), but actual freeing happens
- later when RCU grace period is over. This allows safe lock-free
- walking of the hash chains, but a matched dentry may have been
- partially torn down. The checking of DCACHE_UNHASHED flag with
- d_lock held detects such dentries and prevents them from being
- returned from look-up.
-
-
-Maintaining POSIX rename semantics
-==================================
-
-Since look-up of dentries is lock-free, it can race against a
-concurrent rename operation. For example, during rename of file A to
-B, look-up of either A or B must succeed. So, if look-up of B happens
-after A has been removed from the hash chain but not added to the new
-hash chain, it may fail. Also, a comparison while the name is being
-written concurrently by a rename may result in false positive matches
-violating rename semantics. Issues related to race with rename are
-handled as described below :
-
-1. Look-up can be done in two ways - d_lookup() which is safe from
- simultaneous renames and __d_lookup() which is not. If
- __d_lookup() fails, it must be followed up by a d_lookup() to
- correctly determine whether a dentry is in the hash table or
- not. d_lookup() protects look-ups using a sequence lock
- (rename_lock).
-
-2. The name associated with a dentry (d_name) may be changed if a
- rename is allowed to happen simultaneously. To avoid memcmp() in
- __d_lookup() go out of bounds due to a rename and false positive
- comparison, the name comparison is done while holding the
- per-dentry lock. This prevents concurrent renames during this
- operation.
-
-3. Hash table walking during look-up may move to a different bucket as
- the current dentry is moved to a different bucket due to rename.
- But we use hlists in dcache hash table and they are
- null-terminated. So, even if a dentry moves to a different bucket,
- hash chain walk will terminate. [with a list_head list, it may not
- since termination is when the list_head in the original bucket is
- reached]. Since we redo the d_parent check and compare name while
- holding d_lock, lock-free look-up will not race against d_move().
-
-4. There can be a theoretical race when a dentry keeps coming back to
- original bucket due to double moves. Due to this look-up may
- consider that it has never moved and can end up in a infinite loop.
- But this is not any worse that theoretical livelocks we already
- have in the kernel.
-
-
-Important guidelines for filesystem developers related to dcache_rcu
-====================================================================
-
-1. Existing dcache interfaces (pre-2.5.62) exported to filesystem
- don't change. Only dcache internal implementation changes. However
- filesystems *must not* delete from the dentry hash chains directly
- using the list macros like allowed earlier. They must use dcache
- APIs like d_drop() or __d_drop() depending on the situation.
-
-2. d_flags is now protected by a per-dentry lock (d_lock). All access
- to d_flags must be protected by it.
-
-3. For a hashed dentry, checking of d_count needs to be protected by
- d_lock.
-
-
-Papers and other documentation on dcache locking
-================================================
-
-1. Scaling dcache with RCU (http://linuxjournal.com/article.php?sid=7124).
-
-2. http://lse.sourceforge.net/locking/dcache/dcache.html
-
-
-
--- /dev/null
+Path walking and name lookup locking
+====================================
+
+Path resolution is the finding a dentry corresponding to a path name string, by
+performing a path walk. Typically, for every open(), stat() etc., the path name
+will be resolved. Paths are resolved by walking the namespace tree, starting
+with the first component of the pathname (eg. root or cwd) with a known dentry,
+then finding the child of that dentry, which is named the next component in the
+path string. Then repeating the lookup from the child dentry and finding its
+child with the next element, and so on.
+
+Since it is a frequent operation for workloads like multiuser environments and
+web servers, it is important to optimize this code.
+
+Path walking synchronisation history:
+Prior to 2.5.10, dcache_lock was acquired in d_lookup (dcache hash lookup) and
+thus in every component during path look-up. Since 2.5.10 onwards, fast-walk
+algorithm changed this by holding the dcache_lock at the beginning and walking
+as many cached path component dentries as possible. This significantly
+decreases the number of acquisition of dcache_lock. However it also increases
+the lock hold time significantly and affects performance in large SMP machines.
+Since 2.5.62 kernel, dcache has been using a new locking model that uses RCU to
+make dcache look-up lock-free.
+
+All the above algorithms required taking a lock and reference count on the
+dentry that was looked up, so that may be used as the basis for walking the
+next path element. This is inefficient and unscalable. It is inefficient
+because of the locks and atomic operations required for every dentry element
+slows things down. It is not scalable because many parallel applications that
+are path-walk intensive tend to do path lookups starting from a common dentry
+(usually, the root "/" or current working directory). So contention on these
+common path elements causes lock and cacheline queueing.
+
+Since 2.6.38, RCU is used to make a significant part of the entire path walk
+(including dcache look-up) completely "store-free" (so, no locks, atomics, or
+even stores into cachelines of common dentries). This is known as "rcu-walk"
+path walking.
+
+Path walking overview
+=====================
+
+A name string specifies a start (root directory, cwd, fd-relative) and a
+sequence of elements (directory entry names), which together refer to a path in
+the namespace. A path is represented as a (dentry, vfsmount) tuple. The name
+elements are sub-strings, seperated by '/'.
+
+Name lookups will want to find a particular path that a name string refers to
+(usually the final element, or parent of final element). This is done by taking
+the path given by the name's starting point (which we know in advance -- eg.
+current->fs->cwd or current->fs->root) as the first parent of the lookup. Then
+iteratively for each subsequent name element, look up the child of the current
+parent with the given name and if it is not the desired entry, make it the
+parent for the next lookup.
+
+A parent, of course, must be a directory, and we must have appropriate
+permissions on the parent inode to be able to walk into it.
+
+Turning the child into a parent for the next lookup requires more checks and
+procedures. Symlinks essentially substitute the symlink name for the target
+name in the name string, and require some recursive path walking. Mount points
+must be followed into (thus changing the vfsmount that subsequent path elements
+refer to), switching from the mount point path to the root of the particular
+mounted vfsmount. These behaviours are variously modified depending on the
+exact path walking flags.
+
+Path walking then must, broadly, do several particular things:
+- find the start point of the walk;
+- perform permissions and validity checks on inodes;
+- perform dcache hash name lookups on (parent, name element) tuples;
+- traverse mount points;
+- traverse symlinks;
+- lookup and create missing parts of the path on demand.
+
+Safe store-free look-up of dcache hash table
+============================================
+
+Dcache name lookup
+------------------
+In order to lookup a dcache (parent, name) tuple, we take a hash on the tuple
+and use that to select a bucket in the dcache-hash table. The list of entries
+in that bucket is then walked, and we do a full comparison of each entry
+against our (parent, name) tuple.
+
+The hash lists are RCU protected, so list walking is not serialised with
+concurrent updates (insertion, deletion from the hash). This is a standard RCU
+list application with the exception of renames, which will be covered below.
+
+Parent and name members of a dentry, as well as its membership in the dcache
+hash, and its inode are protected by the per-dentry d_lock spinlock. A
+reference is taken on the dentry (while the fields are verified under d_lock),
+and this stabilises its d_inode pointer and actual inode. This gives a stable
+point to perform the next step of our path walk against.
+
+These members are also protected by d_seq seqlock, although this offers
+read-only protection and no durability of results, so care must be taken when
+using d_seq for synchronisation (see seqcount based lookups, below).
+
+Renames
+-------
+Back to the rename case. In usual RCU protected lists, the only operations that
+will happen to an object is insertion, and then eventually removal from the
+list. The object will not be reused until an RCU grace period is complete.
+This ensures the RCU list traversal primitives can run over the object without
+problems (see RCU documentation for how this works).
+
+However when a dentry is renamed, its hash value can change, requiring it to be
+moved to a new hash list. Allocating and inserting a new alias would be
+expensive and also problematic for directory dentries. Latency would be far to
+high to wait for a grace period after removing the dentry and before inserting
+it in the new hash bucket. So what is done is to insert the dentry into the
+new list immediately.
+
+However, when the dentry's list pointers are updated to point to objects in the
+new list before waiting for a grace period, this can result in a concurrent RCU
+lookup of the old list veering off into the new (incorrect) list and missing
+the remaining dentries on the list.
+
+There is no fundamental problem with walking down the wrong list, because the
+dentry comparisons will never match. However it is fatal to miss a matching
+dentry. So a seqlock is used to detect when a rename has occurred, and so the
+lookup can be retried.
+
+ 1 2 3
+ +---+ +---+ +---+
+hlist-->| N-+->| N-+->| N-+->
+head <--+-P |<-+-P |<-+-P |
+ +---+ +---+ +---+
+
+Rename of dentry 2 may require it deleted from the above list, and inserted
+into a new list. Deleting 2 gives the following list.
+
+ 1 3
+ +---+ +---+ (don't worry, the longer pointers do not
+hlist-->| N-+-------->| N-+-> impose a measurable performance overhead
+head <--+-P |<--------+-P | on modern CPUs)
+ +---+ +---+
+ ^ 2 ^
+ | +---+ |
+ | | N-+----+
+ +----+-P |
+ +---+
+
+This is a standard RCU-list deletion, which leaves the deleted object's
+pointers intact, so a concurrent list walker that is currently looking at
+object 2 will correctly continue to object 3 when it is time to traverse the
+next object.
+
+However, when inserting object 2 onto a new list, we end up with this:
+
+ 1 3
+ +---+ +---+
+hlist-->| N-+-------->| N-+->
+head <--+-P |<--------+-P |
+ +---+ +---+
+ 2
+ +---+
+ | N-+---->
+ <----+-P |
+ +---+
+
+Because we didn't wait for a grace period, there may be a concurrent lookup
+still at 2. Now when it follows 2's 'next' pointer, it will walk off into
+another list without ever having checked object 3.
+
+A related, but distinctly different, issue is that of rename atomicity versus
+lookup operations. If a file is renamed from 'A' to 'B', a lookup must only
+find either 'A' or 'B'. So if a lookup of 'A' returns NULL, a subsequent lookup
+of 'B' must succeed (note the reverse is not true).
+
+Between deleting the dentry from the old hash list, and inserting it on the new
+hash list, a lookup may find neither 'A' nor 'B' matching the dentry. The same
+rename seqlock is also used to cover this race in much the same way, by
+retrying a negative lookup result if a rename was in progress.
+
+Seqcount based lookups
+----------------------
+In refcount based dcache lookups, d_lock is used to serialise access to
+the dentry, stabilising it while comparing its name and parent and then
+taking a reference count (the reference count then gives a stable place to
+start the next part of the path walk from).
+
+As explained above, we would like to do path walking without taking locks or
+reference counts on intermediate dentries along the path. To do this, a per
+dentry seqlock (d_seq) is used to take a "coherent snapshot" of what the dentry
+looks like (its name, parent, and inode). That snapshot is then used to start
+the next part of the path walk. When loading the coherent snapshot under d_seq,
+care must be taken to load the members up-front, and use those pointers rather
+than reloading from the dentry later on (otherwise we'd have interesting things
+like d_inode going NULL underneath us, if the name was unlinked).
+
+Also important is to avoid performing any destructive operations (pretty much:
+no non-atomic stores to shared data), and to recheck the seqcount when we are
+"done" with the operation. Retry or abort if the seqcount does not match.
+Avoiding destructive or changing operations means we can easily unwind from
+failure.
+
+What this means is that a caller, provided they are holding RCU lock to
+protect the dentry object from disappearing, can perform a seqcount based
+lookup which does not increment the refcount on the dentry or write to
+it in any way. This returned dentry can be used for subsequent operations,
+provided that d_seq is rechecked after that operation is complete.
+
+Inodes are also rcu freed, so the seqcount lookup dentry's inode may also be
+queried for permissions.
+
+With this two parts of the puzzle, we can do path lookups without taking
+locks or refcounts on dentry elements.
+
+RCU-walk path walking design
+============================
+
+Path walking code now has two distinct modes, ref-walk and rcu-walk. ref-walk
+is the traditional[*] way of performing dcache lookups using d_lock to
+serialise concurrent modifications to the dentry and take a reference count on
+it. ref-walk is simple and obvious, and may sleep, take locks, etc while path
+walking is operating on each dentry. rcu-walk uses seqcount based dentry
+lookups, and can perform lookup of intermediate elements without any stores to
+shared data in the dentry or inode. rcu-walk can not be applied to all cases,
+eg. if the filesystem must sleep or perform non trivial operations, rcu-walk
+must be switched to ref-walk mode.
+
+[*] RCU is still used for the dentry hash lookup in ref-walk, but not the full
+ path walk.
+
+Where ref-walk uses a stable, refcounted ``parent'' to walk the remaining
+path string, rcu-walk uses a d_seq protected snapshot. When looking up a
+child of this parent snapshot, we open d_seq critical section on the child
+before closing d_seq critical section on the parent. This gives an interlocking
+ladder of snapshots to walk down.
+
+
+ proc 101
+ /----------------\
+ / comm: "vi" \
+ / fs.root: dentry0 \
+ \ fs.cwd: dentry2 /
+ \ /
+ \----------------/
+
+So when vi wants to open("/home/npiggin/test.c", O_RDWR), then it will
+start from current->fs->root, which is a pinned dentry. Alternatively,
+"./test.c" would start from cwd; both names refer to the same path in
+the context of proc101.
+
+ dentry 0
+ +---------------------+ rcu-walk begins here, we note d_seq, check the
+ | name: "/" | inode's permission, and then look up the next
+ | inode: 10 | path element which is "home"...
+ | children:"home", ...|
+ +---------------------+
+ |
+ dentry 1 V
+ +---------------------+ ... which brings us here. We find dentry1 via
+ | name: "home" | hash lookup, then note d_seq and compare name
+ | inode: 678 | string and parent pointer. When we have a match,
+ | children:"npiggin" | we now recheck the d_seq of dentry0. Then we
+ +---------------------+ check inode and look up the next element.
+ |
+ dentry2 V
+ +---------------------+ Note: if dentry0 is now modified, lookup is
+ | name: "npiggin" | not necessarily invalid, so we need only keep a
+ | inode: 543 | parent for d_seq verification, and grandparents
+ | children:"a.c", ... | can be forgotten.
+ +---------------------+
+ |
+ dentry3 V
+ +---------------------+ At this point we have our destination dentry.
+ | name: "a.c" | We now take its d_lock, verify d_seq of this
+ | inode: 14221 | dentry. If that checks out, we can increment
+ | children:NULL | its refcount because we're holding d_lock.
+ +---------------------+
+
+Taking a refcount on a dentry from rcu-walk mode, by taking its d_lock,
+re-checking its d_seq, and then incrementing its refcount is called
+"dropping rcu" or dropping from rcu-walk into ref-walk mode.
+
+It is, in some sense, a bit of a house of cards. If the seqcount check of the
+parent snapshot fails, the house comes down, because we had closed the d_seq
+section on the grandparent, so we have nothing left to stand on. In that case,
+the path walk must be fully restarted (which we do in ref-walk mode, to avoid
+live locks). It is costly to have a full restart, but fortunately they are
+quite rare.
+
+When we reach a point where sleeping is required, or a filesystem callout
+requires ref-walk, then instead of restarting the walk, we attempt to drop rcu
+at the last known good dentry we have. Avoiding a full restart in ref-walk in
+these cases is fundamental for performance and scalability because blocking
+operations such as creates and unlinks are not uncommon.
+
+The detailed design for rcu-walk is like this:
+* LOOKUP_RCU is set in nd->flags, which distinguishes rcu-walk from ref-walk.
+* Take the RCU lock for the entire path walk, starting with the acquiring
+ of the starting path (eg. root/cwd/fd-path). So now dentry refcounts are
+ not required for dentry persistence.
+* synchronize_rcu is called when unregistering a filesystem, so we can
+ access d_ops and i_ops during rcu-walk.
+* Similarly take the vfsmount lock for the entire path walk. So now mnt
+ refcounts are not required for persistence. Also we are free to perform mount
+ lookups, and to assume dentry mount points and mount roots are stable up and
+ down the path.
+* Have a per-dentry seqlock to protect the dentry name, parent, and inode,
+ so we can load this tuple atomically, and also check whether any of its
+ members have changed.
+* Dentry lookups (based on parent, candidate string tuple) recheck the parent
+ sequence after the child is found in case anything changed in the parent
+ during the path walk.
+* inode is also RCU protected so we can load d_inode and use the inode for
+ limited things.
+* i_mode, i_uid, i_gid can be tested for exec permissions during path walk.
+* i_op can be loaded.
+* When the destination dentry is reached, drop rcu there (ie. take d_lock,
+ verify d_seq, increment refcount).
+* If seqlock verification fails anywhere along the path, do a full restart
+ of the path lookup in ref-walk mode. -ECHILD tends to be used (for want of
+ a better errno) to signal an rcu-walk failure.
+
+The cases where rcu-walk cannot continue are:
+* NULL dentry (ie. any uncached path element)
+* Following links
+
+It may be possible eventually to make following links rcu-walk aware.
+
+Uncached path elements will always require dropping to ref-walk mode, at the
+very least because i_mutex needs to be grabbed, and objects allocated.
+
+Final note:
+"store-free" path walking is not strictly store free. We take vfsmount lock
+and refcounts (both of which can be made per-cpu), and we also store to the
+stack (which is essentially CPU-local), and we also have to take locks and
+refcount on final dentry.
+
+The point is that shared data, where practically possible, is not locked
+or stored into. The result is massive improvements in performance and
+scalability of path resolution.
+
+
+Interesting statistics
+======================
+
+The following table gives rcu lookup statistics for a few simple workloads
+(2s12c24t Westmere, debian non-graphical system). Ungraceful are attempts to
+drop rcu that fail due to d_seq failure and requiring the entire path lookup
+again. Other cases are successful rcu-drops that are required before the final
+element, nodentry for missing dentry, revalidate for filesystem revalidate
+routine requiring rcu drop, permission for permission check requiring drop,
+and link for symlink traversal requiring drop.
+
+ rcu-lookups restart nodentry link revalidate permission
+bootup 47121 0 4624 1010 10283 7852
+dbench 25386793 0 6778659(26.7%) 55 549 1156
+kbuild 2696672 10 64442(2.3%) 108764(4.0%) 1 1590
+git diff 39605 0 28 2 0 106
+vfstest 24185492 4945 708725(2.9%) 1076136(4.4%) 0 2651
+
+What this shows is that failed rcu-walk lookups, ie. ones that are restarted
+entirely with ref-walk, are quite rare. Even the "vfstest" case which
+specifically has concurrent renames/mkdir/rmdir/ creat/unlink/etc to excercise
+such races is not showing a huge amount of restarts.
+
+Dropping from rcu-walk to ref-walk mean that we have encountered a dentry where
+the reference count needs to be taken for some reason. This is either because
+we have reached the target of the path walk, or because we have encountered a
+condition that can't be resolved in rcu-walk mode. Ideally, we drop rcu-walk
+only when we have reached the target dentry, so the other statistics show where
+this does not happen.
+
+Note that a graceful drop from rcu-walk mode due to something such as the
+dentry not existing (which can be common) is not necessarily a failure of
+rcu-walk scheme, because some elements of the path may have been walked in
+rcu-walk mode. The further we get from common path elements (such as cwd or
+root), the less contended the dentry is likely to be. The closer we are to
+common path elements, the more likely they will exist in dentry cache.
+
+
+Papers and other documentation on dcache locking
+================================================
+
+1. Scaling dcache with RCU (http://linuxjournal.com/article.php?sid=7124).
+
+2. http://lse.sourceforge.net/locking/dcache/dcache.html
+
+
->d_parent changes are not protected by BKL anymore. Read access is safe
if at least one of the following is true:
* filesystem has no cross-directory rename()
- * dcache_lock is held
* we know that parent had been locked (e.g. we are looking at
->d_parent of ->lookup() argument).
* we are called from ->rename().
may happen while the inode is in the middle of ->write_inode(); e.g. if you blindly
free the on-disk inode, you may end up doing that while ->write_inode() is writing
to it.
+
+---
+[mandatory]
+
+ .d_delete() now only advises the dcache as to whether or not to cache
+unreferenced dentries, and is now only called when the dentry refcount goes to
+0. Even on 0 refcount transition, it must be able to tolerate being called 0,
+1, or more times (eg. constant, idempotent).
+
+---
+[mandatory]
+
+ .d_compare() calling convention and locking rules are significantly
+changed. Read updated documentation in Documentation/filesystems/vfs.txt (and
+look at examples of other filesystems) for guidance.
+
+---
+[mandatory]
+
+ .d_hash() calling convention and locking rules are significantly
+changed. Read updated documentation in Documentation/filesystems/vfs.txt (and
+look at examples of other filesystems) for guidance.
+
+---
+[mandatory]
+ dcache_lock is gone, replaced by fine grained locks. See fs/dcache.c
+for details of what locks to replace dcache_lock with in order to protect
+particular things. Most of the time, a filesystem only needs ->d_lock, which
+protects *all* the dcache state of a given dentry.
+
+--
+[mandatory]
+
+ Filesystems must RCU-free their inodes, if they can have been accessed
+via rcu-walk path walk (basically, if the file can have had a path name in the
+vfs namespace).
+
+ i_dentry and i_rcu share storage in a union, and the vfs expects
+i_dentry to be reinitialized before it is freed, so an:
+
+ INIT_LIST_HEAD(&inode->i_dentry);
+
+must be done in the RCU callback.
+
+--
+[recommended]
+ vfs now tries to do path walking in "rcu-walk mode", which avoids
+atomic operations and scalability hazards on dentries and inodes (see
+Documentation/filesystems/path-walk.txt). d_hash and d_compare changes (above)
+are examples of the changes required to support this. For more complex
+filesystem callbacks, the vfs drops out of rcu-walk mode before the fs call, so
+no changes are required to the filesystem. However, this is costly and loses
+the benefits of rcu-walk mode. We will begin to add filesystem callbacks that
+are rcu-walk aware, shown below. Filesystems should take advantage of this
+where possible.
+
+--
+[mandatory]
+ d_revalidate is a callback that is made on every path element (if
+the filesystem provides it), which requires dropping out of rcu-walk mode. This
+may now be called in rcu-walk mode (nd->flags & LOOKUP_RCU). -ECHILD should be
+returned if the filesystem cannot handle rcu-walk. See
+Documentation/filesystems/vfs.txt for more details.
+
+ permission and check_acl are inode permission checks that are called
+on many or all directory inodes on the way down a path walk (to check for
+exec permission). These must now be rcu-walk aware (flags & IPERM_RCU). See
+Documentation/filesystems/vfs.txt for more details.
void * (*follow_link) (struct dentry *, struct nameidata *);
void (*put_link) (struct dentry *, struct nameidata *, void *);
void (*truncate) (struct inode *);
- int (*permission) (struct inode *, int, struct nameidata *);
+ int (*permission) (struct inode *, int, unsigned int);
+ int (*check_acl)(struct inode *, int, unsigned int);
int (*setattr) (struct dentry *, struct iattr *);
int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *);
int (*setxattr) (struct dentry *, const char *,const void *,size_t,int);
permission: called by the VFS to check for access rights on a POSIX-like
filesystem.
+ May be called in rcu-walk mode (flags & IPERM_RCU). If in rcu-walk
+ mode, the filesystem must check the permission without blocking or
+ storing to the inode.
+
+ If a situation is encountered that rcu-walk cannot handle, return
+ -ECHILD and it will be called again in ref-walk mode.
+
setattr: called by the VFS to set attributes for a file. This method
is called by chmod(2) and related system calls.
struct dentry_operations {
int (*d_revalidate)(struct dentry *, struct nameidata *);
- int (*d_hash) (struct dentry *, struct qstr *);
- int (*d_compare) (struct dentry *, struct qstr *, struct qstr *);
- int (*d_delete)(struct dentry *);
+ int (*d_hash)(const struct dentry *, const struct inode *,
+ struct qstr *);
+ int (*d_compare)(const struct dentry *, const struct inode *,
+ const struct dentry *, const struct inode *,
+ unsigned int, const char *, const struct qstr *);
+ int (*d_delete)(const struct dentry *);
void (*d_release)(struct dentry *);
void (*d_iput)(struct dentry *, struct inode *);
char *(*d_dname)(struct dentry *, char *, int);
dcache. Most filesystems leave this as NULL, because all their
dentries in the dcache are valid
- d_hash: called when the VFS adds a dentry to the hash table
+ d_revalidate may be called in rcu-walk mode (nd->flags & LOOKUP_RCU).
+ If in rcu-walk mode, the filesystem must revalidate the dentry without
+ blocking or storing to the dentry, d_parent and d_inode should not be
+ used without care (because they can go NULL), instead nd->inode should
+ be used.
+
+ If a situation is encountered that rcu-walk cannot handle, return
+ -ECHILD and it will be called again in ref-walk mode.
+
+ d_hash: called when the VFS adds a dentry to the hash table. The first
+ dentry passed to d_hash is the parent directory that the name is
+ to be hashed into. The inode is the dentry's inode.
+
+ Same locking and synchronisation rules as d_compare regarding
+ what is safe to dereference etc.
+
+ d_compare: called to compare a dentry name with a given name. The first
+ dentry is the parent of the dentry to be compared, the second is
+ the parent's inode, then the dentry and inode (may be NULL) of the
+ child dentry. len and name string are properties of the dentry to be
+ compared. qstr is the name to compare it with.
+
+ Must be constant and idempotent, and should not take locks if
+ possible, and should not or store into the dentry or inodes.
+ Should not dereference pointers outside the dentry or inodes without
+ lots of care (eg. d_parent, d_inode, d_name should not be used).
+
+ However, our vfsmount is pinned, and RCU held, so the dentries and
+ inodes won't disappear, neither will our sb or filesystem module.
+ ->i_sb and ->d_sb may be used.
- d_compare: called when a dentry should be compared with another
+ It is a tricky calling convention because it needs to be called under
+ "rcu-walk", ie. without any locks or references on things.
- d_delete: called when the last reference to a dentry is
- deleted. This means no-one is using the dentry, however it is
- still valid and in the dcache
+ d_delete: called when the last reference to a dentry is dropped and the
+ dcache is deciding whether or not to cache it. Return 1 to delete
+ immediately, or 0 to cache the dentry. Default is NULL which means to
+ always cache a reachable dentry. d_delete must be constant and
+ idempotent.
d_release: called when a dentry is really deallocated
the usage count)
dput: close a handle for a dentry (decrements the usage count). If
- the usage count drops to 0, the "d_delete" method is called
- and the dentry is placed on the unused list if the dentry is
- still in its parents hash list. Putting the dentry on the
- unused list just means that if the system needs some RAM, it
- goes through the unused list of dentries and deallocates them.
- If the dentry has already been unhashed and the usage count
- drops to 0, in this case the dentry is deallocated after the
- "d_delete" method is called
+ the usage count drops to 0, and the dentry is still in its
+ parent's hash, the "d_delete" method is called to check whether
+ it should be cached. If it should not be cached, or if the dentry
+ is not hashed, it is deleted. Otherwise cached dentries are put
+ into an LRU list to be reclaimed on memory shortage.
d_drop: this unhashes a dentry from its parents hash list. A
subsequent call to dput() will deallocate the dentry if its
* any operations on the root directory. However, we need a non-trivial
* d_name - pfm: will go nicely and kill the special-casing in procfs.
*/
-static struct vfsmount *pfmfs_mnt;
+static struct vfsmount *pfmfs_mnt __read_mostly;
static int __init
init_pfm_fs(void)
};
static int
-pfmfs_delete_dentry(struct dentry *dentry)
+pfmfs_delete_dentry(const struct dentry *dentry)
{
return 1;
}
}
path.mnt = mntget(pfmfs_mnt);
- path.dentry->d_op = &pfmfs_dentry_operations;
+ d_set_d_op(path.dentry, &pfmfs_dentry_operations);
d_add(path.dentry, inode);
file = alloc_file(&path, FMODE_READ, &pfm_file_ops);
return &ei->vfs_inode;
}
-static void
-spufs_destroy_inode(struct inode *inode)
+static void spufs_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(spufs_inode_cache, SPUFS_I(inode));
}
+static void spufs_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, spufs_i_callback);
+}
+
static void
spufs_init_once(void *p)
{
mutex_lock(&dir->d_inode->i_mutex);
list_for_each_entry_safe(dentry, tmp, &dir->d_subdirs, d_u.d_child) {
- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
if (!(d_unhashed(dentry)) && dentry->d_inode) {
- dget_locked(dentry);
+ dget_dlock(dentry);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
simple_unlink(dir->d_inode, dentry);
- spin_unlock(&dcache_lock);
+ /* XXX: what was dcache_lock protecting here? Other
+ * filesystems (IB, configfs) release dcache_lock
+ * before unlink */
dput(dentry);
} else {
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
}
}
shrink_dcache_parent(dir);
goto bail;
}
- spin_lock(&dcache_lock);
spin_lock(&tmp->d_lock);
if (!(d_unhashed(tmp) && tmp->d_inode)) {
- dget_locked(tmp);
+ dget_dlock(tmp);
__d_drop(tmp);
spin_unlock(&tmp->d_lock);
- spin_unlock(&dcache_lock);
simple_unlink(parent->d_inode, tmp);
- } else {
+ } else
spin_unlock(&tmp->d_lock);
- spin_unlock(&dcache_lock);
- }
ret = 0;
bail:
goto bail;
}
- spin_lock(&dcache_lock);
spin_lock(&tmp->d_lock);
if (!(d_unhashed(tmp) && tmp->d_inode)) {
- dget_locked(tmp);
+ dget_dlock(tmp);
__d_drop(tmp);
spin_unlock(&tmp->d_lock);
- spin_unlock(&dcache_lock);
simple_unlink(parent->d_inode, tmp);
} else {
spin_unlock(&tmp->d_lock);
- spin_unlock(&dcache_lock);
}
ret = 0;
static void __exit cleanup_mtdchar(void)
{
unregister_mtd_user(&mtdchar_notifier);
- mntput(mtd_inode_mnt);
+ mntput_long(mtd_inode_mnt);
unregister_filesystem(&mtd_inodefs_type);
__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
}
* yet completely filled in, and revalidate has to delay such
* lookups..
*/
-static int autofs_revalidate(struct dentry * dentry, struct nameidata *nd)
+static int autofs_revalidate(struct dentry *dentry, struct nameidata *nd)
{
struct inode * dir;
struct autofs_sb_info *sbi;
struct autofs_dir_ent *ent;
int res;
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
lock_kernel();
dir = dentry->d_parent->d_inode;
sbi = autofs_sbi(dir->i_sb);
*
* We need to do this before we release the directory semaphore.
*/
- dentry->d_op = &autofs_dentry_operations;
+ d_set_d_op(dentry, &autofs_dentry_operations);
dentry->d_flags |= DCACHE_AUTOFS_PENDING;
d_add(dentry, NULL);
.set_page_dirty = __set_page_dirty_nobuffers,
};
+static void pohmelfs_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
+ kmem_cache_free(pohmelfs_inode_cache, POHMELFS_I(inode));
+}
+
/*
* ->detroy_inode() callback. Deletes inode from the caches
* and frees private data.
dprintk("%s: pi: %p, inode: %p, ino: %llu.\n",
__func__, pi, &pi->vfs_inode, pi->ino);
- kmem_cache_free(pohmelfs_inode_cache, pi);
atomic_long_dec(&psb->total_inodes);
+ call_rcu(&inode->i_rcu, pohmelfs_i_callback);
}
/*
int pohmelfs_path_length(struct pohmelfs_inode *pi)
{
struct dentry *d, *root, *first;
- int len = 1; /* Root slash */
+ int len;
+ unsigned seq;
- first = d = d_find_alias(&pi->vfs_inode);
- if (!d) {
+ first = d_find_alias(&pi->vfs_inode);
+ if (!first) {
dprintk("%s: ino: %llu, mode: %o.\n", __func__, pi->ino, pi->vfs_inode.i_mode);
return -ENOENT;
}
root = dget(current->fs->root.dentry);
spin_unlock(¤t->fs->lock);
- spin_lock(&dcache_lock);
+rename_retry:
+ len = 1; /* Root slash */
+ d = first;
+ seq = read_seqbegin(&rename_lock);
+ rcu_read_lock();
if (!IS_ROOT(d) && d_unhashed(d))
len += UNHASHED_OBSCURE_STRING_SIZE; /* Obscure " (deleted)" string */
len += d->d_name.len + 1; /* Plus slash */
d = d->d_parent;
}
- spin_unlock(&dcache_lock);
+ rcu_read_unlock();
+ if (read_seqretry(&rename_lock, seq))
+ goto rename_retry;
dput(root);
dput(first);
struct list_head *next;
struct dentry *dentry;
- spin_lock(&dcache_lock);
+ spin_lock(&parent->d_lock);
next = parent->d_subdirs.next;
while (next != &parent->d_subdirs) {
dentry = list_entry(next, struct dentry, d_u.d_child);
smb_age_dentry(server, dentry);
next = next->next;
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&parent->d_lock);
}
/*
}
/* If a pointer is invalid, we search the dentry. */
- spin_lock(&dcache_lock);
+ spin_lock(&parent->d_lock);
next = parent->d_subdirs.next;
while (next != &parent->d_subdirs) {
dent = list_entry(next, struct dentry, d_u.d_child);
if ((unsigned long)dent->d_fsdata == fpos) {
if (dent->d_inode)
- dget_locked(dent);
+ dget(dent);
else
dent = NULL;
goto out_unlock;
}
dent = NULL;
out_unlock:
- spin_unlock(&dcache_lock);
+ spin_unlock(&parent->d_lock);
return dent;
}
qname->hash = full_name_hash(qname->name, qname->len);
if (dentry->d_op && dentry->d_op->d_hash)
- if (dentry->d_op->d_hash(dentry, qname) != 0)
+ if (dentry->d_op->d_hash(dentry, inode, qname) != 0)
goto end_advance;
newdent = d_lookup(dentry, qname);
goto end_advance;
} else {
hashed = 1;
- memcpy((char *) newdent->d_name.name, qname->name,
- newdent->d_name.len);
+ /* dir i_mutex is locked because we're in readdir */
+ dentry_update_name_case(newdent, qname);
}
if (!newdent->d_inode) {
#include <linux/ctype.h>
#include <linux/net.h>
#include <linux/sched.h>
+#include <linux/namei.h>
#include "smb_fs.h"
#include "smb_mount.h"
* Dentry operations routines
*/
static int smb_lookup_validate(struct dentry *, struct nameidata *);
-static int smb_hash_dentry(struct dentry *, struct qstr *);
-static int smb_compare_dentry(struct dentry *, struct qstr *, struct qstr *);
-static int smb_delete_dentry(struct dentry *);
+static int smb_hash_dentry(const struct dentry *, const struct inode *,
+ struct qstr *);
+static int smb_compare_dentry(const struct dentry *,
+ const struct inode *,
+ const struct dentry *, const struct inode *,
+ unsigned int, const char *, const struct qstr *);
+static int smb_delete_dentry(const struct dentry *);
static const struct dentry_operations smbfs_dentry_operations =
{
* This is the callback when the dcache has a lookup hit.
*/
static int
-smb_lookup_validate(struct dentry * dentry, struct nameidata *nd)
+smb_lookup_validate(struct dentry *dentry, struct nameidata *nd)
{
- struct smb_sb_info *server = server_from_dentry(dentry);
- struct inode * inode = dentry->d_inode;
- unsigned long age = jiffies - dentry->d_time;
+ struct smb_sb_info *server;
+ struct inode *inode;
+ unsigned long age;
int valid;
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ server = server_from_dentry(dentry);
+ inode = dentry->d_inode;
+ age = jiffies - dentry->d_time;
+
/*
* The default validation is based on dentry age:
* we believe in dentries for a few seconds. (But each
}
static int
-smb_hash_dentry(struct dentry *dir, struct qstr *this)
+smb_hash_dentry(const struct dentry *dir, const struct inode *inode,
+ struct qstr *this)
{
unsigned long hash;
int i;
}
static int
-smb_compare_dentry(struct dentry *dir, struct qstr *a, struct qstr *b)
+smb_compare_dentry(const struct dentry *parent,
+ const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name)
{
int i, result = 1;
- if (a->len != b->len)
+ if (len != name->len)
goto out;
- for (i=0; i < a->len; i++) {
- if (tolower(a->name[i]) != tolower(b->name[i]))
+ for (i=0; i < len; i++) {
+ if (tolower(str[i]) != tolower(name->name[i]))
goto out;
}
result = 0;
* We use this to unhash dentries with bad inodes.
*/
static int
-smb_delete_dentry(struct dentry * dentry)
+smb_delete_dentry(const struct dentry *dentry)
{
if (dentry->d_inode) {
if (is_bad_inode(dentry->d_inode)) {
struct smb_sb_info *server = server_from_dentry(dentry);
if (server->mnt->flags & SMB_MOUNT_CASE)
- dentry->d_op = &smbfs_dentry_operations_case;
+ d_set_d_op(dentry, &smbfs_dentry_operations_case);
else
- dentry->d_op = &smbfs_dentry_operations;
+ d_set_d_op(dentry, &smbfs_dentry_operations);
dentry->d_time = jiffies;
}
add_entry:
server = server_from_dentry(dentry);
if (server->mnt->flags & SMB_MOUNT_CASE)
- dentry->d_op = &smbfs_dentry_operations_case;
+ d_set_d_op(dentry, &smbfs_dentry_operations_case);
else
- dentry->d_op = &smbfs_dentry_operations;
+ d_set_d_op(dentry, &smbfs_dentry_operations);
d_add(dentry, inode);
smb_renew_times(dentry);
* privileges, so we need our own check for this.
*/
static int
-smb_file_permission(struct inode *inode, int mask)
+smb_file_permission(struct inode *inode, int mask, unsigned int flags)
{
int mode = inode->i_mode;
int error = 0;
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
+
VERBOSE("mode=%x, mask=%x\n", mode, mask);
/* Look at user permissions */
return &ei->vfs_inode;
}
-static void smb_destroy_inode(struct inode *inode)
+static void smb_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(smb_inode_cachep, SMB_I(inode));
}
+static void smb_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, smb_i_callback);
+}
+
static void init_once(void *foo)
{
struct smb_inode_info *ei = (struct smb_inode_info *) foo;
{
struct list_head *list;
- spin_lock(&dcache_lock);
-
+ spin_lock(&dentry->d_lock);
list_for_each(list, &dentry->d_subdirs) {
struct dentry *de = list_entry(list, struct dentry, d_u.d_child);
+
+ spin_lock_nested(&de->d_lock, DENTRY_D_LOCK_NESTED);
if (usbfs_positive(de)) {
- spin_unlock(&dcache_lock);
+ spin_unlock(&de->d_lock);
+ spin_unlock(&dentry->d_lock);
return 0;
}
+ spin_unlock(&de->d_lock);
}
-
- spin_unlock(&dcache_lock);
+ spin_unlock(&dentry->d_lock);
return 1;
}
return acl;
}
-int v9fs_check_acl(struct inode *inode, int mask)
+int v9fs_check_acl(struct inode *inode, int mask, unsigned int flags)
{
struct posix_acl *acl;
struct v9fs_session_info *v9ses;
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
+
v9ses = v9fs_inode2v9ses(inode);
if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) {
/*
#ifdef CONFIG_9P_FS_POSIX_ACL
extern int v9fs_get_acl(struct inode *, struct p9_fid *);
-extern int v9fs_check_acl(struct inode *inode, int mask);
+extern int v9fs_check_acl(struct inode *inode, int mask, unsigned int flags);
extern int v9fs_acl_chmod(struct dentry *);
extern int v9fs_set_create_acl(struct dentry *,
struct posix_acl *, struct posix_acl *);
*
*/
-static int v9fs_dentry_delete(struct dentry *dentry)
+static int v9fs_dentry_delete(const struct dentry *dentry)
{
P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_name.name,
dentry);
*
*/
-static int v9fs_cached_dentry_delete(struct dentry *dentry)
+static int v9fs_cached_dentry_delete(const struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_name.name,
*
*/
-void v9fs_destroy_inode(struct inode *inode)
+static void v9fs_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(vcookie_cache, v9fs_inode2cookie(inode));
}
+
+void v9fs_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, v9fs_i_callback);
+}
#endif
/**
{
struct dentry *dentry;
- spin_lock(&dcache_lock);
+ spin_lock(&inode->i_lock);
/* Directory should have only one entry. */
BUG_ON(S_ISDIR(inode->i_mode) && !list_is_singular(&inode->i_dentry));
dentry = list_entry(inode->i_dentry.next, struct dentry, d_alias);
- spin_unlock(&dcache_lock);
+ spin_unlock(&inode->i_lock);
return dentry;
}
}
if (v9ses->cache)
- dentry->d_op = &v9fs_cached_dentry_operations;
+ d_set_d_op(dentry, &v9fs_cached_dentry_operations);
else
- dentry->d_op = &v9fs_dentry_operations;
+ d_set_d_op(dentry, &v9fs_dentry_operations);
d_instantiate(dentry, inode);
err = v9fs_fid_add(dentry, fid);
err);
goto error;
}
- dentry->d_op = &v9fs_cached_dentry_operations;
+ d_set_d_op(dentry, &v9fs_cached_dentry_operations);
d_instantiate(dentry, inode);
err = v9fs_fid_add(dentry, fid);
if (err < 0)
err = PTR_ERR(inode);
goto error;
}
- dentry->d_op = &v9fs_dentry_operations;
+ d_set_d_op(dentry, &v9fs_dentry_operations);
d_instantiate(dentry, inode);
}
/* Now set the ACL based on the default value */
err);
goto error;
}
- dentry->d_op = &v9fs_cached_dentry_operations;
+ d_set_d_op(dentry, &v9fs_cached_dentry_operations);
d_instantiate(dentry, inode);
err = v9fs_fid_add(dentry, fid);
if (err < 0)
err = PTR_ERR(inode);
goto error;
}
- dentry->d_op = &v9fs_dentry_operations;
+ d_set_d_op(dentry, &v9fs_dentry_operations);
d_instantiate(dentry, inode);
}
/* Now set the ACL based on the default value */
inst_out:
if (v9ses->cache)
- dentry->d_op = &v9fs_cached_dentry_operations;
+ d_set_d_op(dentry, &v9fs_cached_dentry_operations);
else
- dentry->d_op = &v9fs_dentry_operations;
+ d_set_d_op(dentry, &v9fs_dentry_operations);
d_add(dentry, inode);
return NULL;
err);
goto error;
}
- dentry->d_op = &v9fs_cached_dentry_operations;
+ d_set_d_op(dentry, &v9fs_cached_dentry_operations);
d_instantiate(dentry, inode);
err = v9fs_fid_add(dentry, fid);
if (err < 0)
err = PTR_ERR(inode);
goto error;
}
- dentry->d_op = &v9fs_dentry_operations;
+ d_set_d_op(dentry, &v9fs_dentry_operations);
d_instantiate(dentry, inode);
}
ihold(old_dentry->d_inode);
}
- dentry->d_op = old_dentry->d_op;
+ d_set_d_op(dentry, old_dentry->d_op);
d_instantiate(dentry, old_dentry->d_inode);
return err;
err);
goto error;
}
- dentry->d_op = &v9fs_cached_dentry_operations;
+ d_set_d_op(dentry, &v9fs_cached_dentry_operations);
d_instantiate(dentry, inode);
err = v9fs_fid_add(dentry, fid);
if (err < 0)
err = PTR_ERR(inode);
goto error;
}
- dentry->d_op = &v9fs_dentry_operations;
+ d_set_d_op(dentry, &v9fs_dentry_operations);
d_instantiate(dentry, inode);
}
/* Now set the ACL based on the default value */
};
static int
-adfs_hash(struct dentry *parent, struct qstr *qstr)
+adfs_hash(const struct dentry *parent, const struct inode *inode,
+ struct qstr *qstr)
{
const unsigned int name_len = ADFS_SB(parent->d_sb)->s_namelen;
const unsigned char *name;
* requirements of the underlying filesystem.
*/
static int
-adfs_compare(struct dentry *parent, struct qstr *entry, struct qstr *name)
+adfs_compare(const struct dentry *parent, const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name)
{
int i;
- if (entry->len != name->len)
+ if (len != name->len)
return 1;
for (i = 0; i < name->len; i++) {
char a, b;
- a = entry->name[i];
+ a = str[i];
b = name->name[i];
if (a >= 'A' && a <= 'Z')
struct object_info obj;
int error;
- dentry->d_op = &adfs_dentry_operations;
+ d_set_d_op(dentry, &adfs_dentry_operations);
lock_kernel();
error = adfs_dir_lookup_byname(dir, &dentry->d_name, &obj);
if (error == 0) {
return &ei->vfs_inode;
}
-static void adfs_destroy_inode(struct inode *inode)
+static void adfs_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(adfs_inode_cachep, ADFS_I(inode));
}
+static void adfs_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, adfs_i_callback);
+}
+
static void init_once(void *foo)
{
struct adfs_inode_info *ei = (struct adfs_inode_info *) foo;
adfs_error(sb, "get root inode failed\n");
goto error;
} else
- sb->s_root->d_op = &adfs_dentry_operations;
+ d_set_d_op(sb->s_root, &adfs_dentry_operations);
unlock_kernel();
return 0;
void *data = dentry->d_fsdata;
struct list_head *head, *next;
- spin_lock(&dcache_lock);
+ spin_lock(&inode->i_lock);
head = &inode->i_dentry;
next = head->next;
while (next != head) {
}
next = next->next;
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&inode->i_lock);
}
typedef int (*toupper_t)(int);
static int affs_toupper(int ch);
-static int affs_hash_dentry(struct dentry *, struct qstr *);
-static int affs_compare_dentry(struct dentry *, struct qstr *, struct qstr *);
+static int affs_hash_dentry(const struct dentry *,
+ const struct inode *, struct qstr *);
+static int affs_compare_dentry(const struct dentry *parent,
+ const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name);
static int affs_intl_toupper(int ch);
-static int affs_intl_hash_dentry(struct dentry *, struct qstr *);
-static int affs_intl_compare_dentry(struct dentry *, struct qstr *, struct qstr *);
+static int affs_intl_hash_dentry(const struct dentry *,
+ const struct inode *, struct qstr *);
+static int affs_intl_compare_dentry(const struct dentry *parent,
+ const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name);
const struct dentry_operations affs_dentry_operations = {
.d_hash = affs_hash_dentry,
* Note: the dentry argument is the parent dentry.
*/
static inline int
-__affs_hash_dentry(struct dentry *dentry, struct qstr *qstr, toupper_t toupper)
+__affs_hash_dentry(struct qstr *qstr, toupper_t toupper)
{
const u8 *name = qstr->name;
unsigned long hash;
int i;
- i = affs_check_name(qstr->name,qstr->len);
+ i = affs_check_name(qstr->name, qstr->len);
if (i)
return i;
}
static int
-affs_hash_dentry(struct dentry *dentry, struct qstr *qstr)
+affs_hash_dentry(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *qstr)
{
- return __affs_hash_dentry(dentry, qstr, affs_toupper);
+ return __affs_hash_dentry(qstr, affs_toupper);
}
static int
-affs_intl_hash_dentry(struct dentry *dentry, struct qstr *qstr)
+affs_intl_hash_dentry(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *qstr)
{
- return __affs_hash_dentry(dentry, qstr, affs_intl_toupper);
+ return __affs_hash_dentry(qstr, affs_intl_toupper);
}
-static inline int
-__affs_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b, toupper_t toupper)
+static inline int __affs_compare_dentry(unsigned int len,
+ const char *str, const struct qstr *name, toupper_t toupper)
{
- const u8 *aname = a->name;
- const u8 *bname = b->name;
- int len;
+ const u8 *aname = str;
+ const u8 *bname = name->name;
- /* 'a' is the qstr of an already existing dentry, so the name
- * must be valid. 'b' must be validated first.
+ /*
+ * 'str' is the name of an already existing dentry, so the name
+ * must be valid. 'name' must be validated first.
*/
- if (affs_check_name(b->name,b->len))
+ if (affs_check_name(name->name, name->len))
return 1;
- /* If the names are longer than the allowed 30 chars,
+ /*
+ * If the names are longer than the allowed 30 chars,
* the excess is ignored, so their length may differ.
*/
- len = a->len;
if (len >= 30) {
- if (b->len < 30)
+ if (name->len < 30)
return 1;
len = 30;
- } else if (len != b->len)
+ } else if (len != name->len)
return 1;
for (; len > 0; len--)
}
static int
-affs_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b)
+affs_compare_dentry(const struct dentry *parent, const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name)
{
- return __affs_compare_dentry(dentry, a, b, affs_toupper);
+ return __affs_compare_dentry(len, str, name, affs_toupper);
}
static int
-affs_intl_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b)
+affs_intl_compare_dentry(const struct dentry *parent,const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name)
{
- return __affs_compare_dentry(dentry, a, b, affs_intl_toupper);
+ return __affs_compare_dentry(len, str, name, affs_intl_toupper);
}
/*
if (IS_ERR(inode))
return ERR_CAST(inode);
}
- dentry->d_op = AFFS_SB(sb)->s_flags & SF_INTL ? &affs_intl_dentry_operations : &affs_dentry_operations;
+ d_set_d_op(dentry, AFFS_SB(sb)->s_flags & SF_INTL ? &affs_intl_dentry_operations : &affs_dentry_operations);
d_add(dentry, inode);
return NULL;
}
return &i->vfs_inode;
}
-static void affs_destroy_inode(struct inode *inode)
+static void affs_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
}
+static void affs_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, affs_i_callback);
+}
+
static void init_once(void *foo)
{
struct affs_inode_info *ei = (struct affs_inode_info *) foo;
printk(KERN_ERR "AFFS: Get root inode failed\n");
goto out_error;
}
- sb->s_root->d_op = &affs_dentry_operations;
+ d_set_d_op(sb->s_root, &affs_dentry_operations);
pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
return 0;
#include <linux/module.h>
#include <linux/init.h>
#include <linux/fs.h>
+#include <linux/namei.h>
#include <linux/pagemap.h>
#include <linux/ctype.h>
#include <linux/sched.h>
static int afs_dir_open(struct inode *inode, struct file *file);
static int afs_readdir(struct file *file, void *dirent, filldir_t filldir);
static int afs_d_revalidate(struct dentry *dentry, struct nameidata *nd);
-static int afs_d_delete(struct dentry *dentry);
+static int afs_d_delete(const struct dentry *dentry);
static void afs_d_release(struct dentry *dentry);
static int afs_lookup_filldir(void *_cookie, const char *name, int nlen,
loff_t fpos, u64 ino, unsigned dtype);
}
success:
- dentry->d_op = &afs_fs_dentry_operations;
+ d_set_d_op(dentry, &afs_fs_dentry_operations);
d_add(dentry, inode);
_leave(" = 0 { vn=%u u=%u } -> { ino=%lu v=%llu }",
void *dir_version;
int ret;
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
vnode = AFS_FS_I(dentry->d_inode);
if (dentry->d_inode)
* - called from dput() when d_count is going to 0.
* - return 1 to request dentry be unhashed, 0 otherwise
*/
-static int afs_d_delete(struct dentry *dentry)
+static int afs_d_delete(const struct dentry *dentry)
{
_enter("%s", dentry->d_name.name);
extern void afs_cache_permit(struct afs_vnode *, struct key *, long);
extern void afs_zap_permits(struct rcu_head *);
extern struct key *afs_request_key(struct afs_cell *);
-extern int afs_permission(struct inode *, int);
+extern int afs_permission(struct inode *, int, unsigned int);
/*
* server.c
* - AFS ACLs are attached to directories only, and a file is controlled by its
* parent directory's ACL
*/
-int afs_permission(struct inode *inode, int mask)
+int afs_permission(struct inode *inode, int mask, unsigned int flags)
{
struct afs_vnode *vnode = AFS_FS_I(inode);
afs_access_t uninitialized_var(access);
struct key *key;
int ret;
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
+
_enter("{{%x:%u},%lx},%x,",
vnode->fid.vid, vnode->fid.vnode, vnode->flags, mask);
}
key_put(key);
- ret = generic_permission(inode, mask, NULL);
+ ret = generic_permission(inode, mask, flags, NULL);
_leave(" = %d", ret);
return ret;
return &vnode->vfs_inode;
}
+static void afs_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ struct afs_vnode *vnode = AFS_FS_I(inode);
+ INIT_LIST_HEAD(&inode->i_dentry);
+ kmem_cache_free(afs_inode_cachep, vnode);
+}
+
/*
* destroy an AFS inode struct
*/
ASSERTCMP(vnode->server, ==, NULL);
- kmem_cache_free(afs_inode_cachep, vnode);
+ call_rcu(&inode->i_rcu, afs_i_callback);
atomic_dec(&afs_count_active_inodes);
}
this.name = name;
this.len = strlen(name);
this.hash = 0;
- path.dentry = d_alloc(anon_inode_mnt->mnt_sb->s_root, &this);
+ path.dentry = d_alloc_pseudo(anon_inode_mnt->mnt_sb, &this);
if (!path.dentry)
goto err_module;
*/
ihold(anon_inode_inode);
- path.dentry->d_op = &anon_inodefs_dentry_operations;
+ d_set_d_op(path.dentry, &anon_inodefs_dentry_operations);
d_instantiate(path.dentry, anon_inode_inode);
error = -ENFILE;
return 0;
err_mntput:
- mntput(anon_inode_mnt);
+ mntput_long(anon_inode_mnt);
err_unregister_filesystem:
unregister_filesystem(&anon_inode_fs_type);
err_exit:
#include <linux/auto_fs4.h>
#include <linux/auto_dev-ioctl.h>
#include <linux/mutex.h>
+#include <linux/spinlock.h>
#include <linux/list.h>
/* This is the range of ioctl() numbers we claim as ours */
current->pid, __func__, ##args); \
} while (0)
+extern spinlock_t autofs4_lock;
+
/* Unified info structure. This is pointed to by both the dentry and
inode structures. Each file in the filesystem has an instance of this
structure. It holds a reference to the dentry, so dentries are never
return dentry->d_inode && !d_unhashed(dentry);
}
-static inline int __simple_empty(struct dentry *dentry)
+static inline void __autofs4_add_expiring(struct dentry *dentry)
{
- struct dentry *child;
- int ret = 0;
-
- list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child)
- if (simple_positive(child))
- goto out;
- ret = 1;
-out:
- return ret;
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ if (ino) {
+ if (list_empty(&ino->expiring))
+ list_add(&ino->expiring, &sbi->expiring_list);
+ }
+ return;
}
static inline void autofs4_add_expiring(struct dentry *dentry)
}
/*
- * Calculate next entry in top down tree traversal.
- * From next_mnt in namespace.c - elegant.
+ * Calculate and dget next entry in top down tree traversal.
*/
-static struct dentry *next_dentry(struct dentry *p, struct dentry *root)
+static struct dentry *get_next_positive_dentry(struct dentry *prev,
+ struct dentry *root)
{
- struct list_head *next = p->d_subdirs.next;
+ struct list_head *next;
+ struct dentry *p, *ret;
+
+ if (prev == NULL)
+ return dget(prev);
+ spin_lock(&autofs4_lock);
+relock:
+ p = prev;
+ spin_lock(&p->d_lock);
+again:
+ next = p->d_subdirs.next;
if (next == &p->d_subdirs) {
while (1) {
- if (p == root)
+ struct dentry *parent;
+
+ if (p == root) {
+ spin_unlock(&p->d_lock);
+ spin_unlock(&autofs4_lock);
+ dput(prev);
return NULL;
+ }
+
+ parent = p->d_parent;
+ if (!spin_trylock(&parent->d_lock)) {
+ spin_unlock(&p->d_lock);
+ cpu_relax();
+ goto relock;
+ }
+ spin_unlock(&p->d_lock);
next = p->d_u.d_child.next;
- if (next != &p->d_parent->d_subdirs)
+ p = parent;
+ if (next != &parent->d_subdirs)
break;
- p = p->d_parent;
}
}
- return list_entry(next, struct dentry, d_u.d_child);
+ ret = list_entry(next, struct dentry, d_u.d_child);
+
+ spin_lock_nested(&ret->d_lock, DENTRY_D_LOCK_NESTED);
+ /* Negative dentry - try next */
+ if (!simple_positive(ret)) {
+ spin_unlock(&ret->d_lock);
+ p = ret;
+ goto again;
+ }
+ dget_dlock(ret);
+ spin_unlock(&ret->d_lock);
+ spin_unlock(&p->d_lock);
+ spin_unlock(&autofs4_lock);
+
+ dput(prev);
+
+ return ret;
}
/*
if (!simple_positive(top))
return 1;
- spin_lock(&dcache_lock);
- for (p = top; p; p = next_dentry(p, top)) {
- /* Negative dentry - give up */
- if (!simple_positive(p))
- continue;
-
+ p = NULL;
+ while ((p = get_next_positive_dentry(p, top))) {
DPRINTK("dentry %p %.*s",
p, (int) p->d_name.len, p->d_name.name);
- p = dget(p);
- spin_unlock(&dcache_lock);
-
/*
* Is someone visiting anywhere in the subtree ?
* If there's no mount we need to check the usage
else
ino_count++;
- if (atomic_read(&p->d_count) > ino_count) {
+ if (p->d_count > ino_count) {
top_ino->last_used = jiffies;
dput(p);
return 1;
}
}
- dput(p);
- spin_lock(&dcache_lock);
}
- spin_unlock(&dcache_lock);
/* Timeout of a tree mount is ultimately determined by its top dentry */
if (!autofs4_can_expire(top, timeout, do_now))
DPRINTK("parent %p %.*s",
parent, (int)parent->d_name.len, parent->d_name.name);
- spin_lock(&dcache_lock);
- for (p = parent; p; p = next_dentry(p, parent)) {
- /* Negative dentry - give up */
- if (!simple_positive(p))
- continue;
-
+ p = NULL;
+ while ((p = get_next_positive_dentry(p, parent))) {
DPRINTK("dentry %p %.*s",
p, (int) p->d_name.len, p->d_name.name);
- p = dget(p);
- spin_unlock(&dcache_lock);
-
if (d_mountpoint(p)) {
/* Can we umount this guy */
if (autofs4_mount_busy(mnt, p))
- goto cont;
+ continue;
/* Can we expire this guy */
if (autofs4_can_expire(p, timeout, do_now))
return p;
}
-cont:
- dput(p);
- spin_lock(&dcache_lock);
}
- spin_unlock(&dcache_lock);
return NULL;
}
struct autofs_info *ino = autofs4_dentry_ino(root);
if (d_mountpoint(root)) {
ino->flags |= AUTOFS_INF_MOUNTPOINT;
- root->d_mounted--;
+ spin_lock(&root->d_lock);
+ root->d_flags &= ~DCACHE_MOUNTED;
+ spin_unlock(&root->d_lock);
}
ino->flags |= AUTOFS_INF_EXPIRING;
init_completion(&ino->expire_complete);
{
unsigned long timeout;
struct dentry *root = sb->s_root;
+ struct dentry *dentry;
struct dentry *expired = NULL;
- struct list_head *next;
int do_now = how & AUTOFS_EXP_IMMEDIATE;
int exp_leaves = how & AUTOFS_EXP_LEAVES;
struct autofs_info *ino;
now = jiffies;
timeout = sbi->exp_timeout;
- spin_lock(&dcache_lock);
- next = root->d_subdirs.next;
-
- /* On exit from the loop expire is set to a dgot dentry
- * to expire or it's NULL */
- while ( next != &root->d_subdirs ) {
- struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child);
-
- /* Negative dentry - give up */
- if (!simple_positive(dentry)) {
- next = next->next;
- continue;
- }
-
- dentry = dget(dentry);
- spin_unlock(&dcache_lock);
-
+ dentry = NULL;
+ while ((dentry = get_next_positive_dentry(dentry, root))) {
spin_lock(&sbi->fs_lock);
ino = autofs4_dentry_ino(dentry);
/* Path walk currently on this dentry? */
ino_count = atomic_read(&ino->count) + 2;
- if (atomic_read(&dentry->d_count) > ino_count)
+ if (dentry->d_count > ino_count)
goto next;
/* Can we umount this guy */
if (!exp_leaves) {
/* Path walk currently on this dentry? */
ino_count = atomic_read(&ino->count) + 1;
- if (atomic_read(&dentry->d_count) > ino_count)
+ if (dentry->d_count > ino_count)
goto next;
if (!autofs4_tree_busy(mnt, dentry, timeout, do_now)) {
} else {
/* Path walk currently on this dentry? */
ino_count = atomic_read(&ino->count) + 1;
- if (atomic_read(&dentry->d_count) > ino_count)
+ if (dentry->d_count > ino_count)
goto next;
expired = autofs4_check_leaves(mnt, dentry, timeout, do_now);
}
next:
spin_unlock(&sbi->fs_lock);
- dput(dentry);
- spin_lock(&dcache_lock);
- next = next->next;
}
- spin_unlock(&dcache_lock);
return NULL;
found:
ino->flags |= AUTOFS_INF_EXPIRING;
init_completion(&ino->expire_complete);
spin_unlock(&sbi->fs_lock);
- spin_lock(&dcache_lock);
+ spin_lock(&autofs4_lock);
+ spin_lock(&expired->d_parent->d_lock);
+ spin_lock_nested(&expired->d_lock, DENTRY_D_LOCK_NESTED);
list_move(&expired->d_parent->d_subdirs, &expired->d_u.d_child);
- spin_unlock(&dcache_lock);
+ spin_unlock(&expired->d_lock);
+ spin_unlock(&expired->d_parent->d_lock);
+ spin_unlock(&autofs4_lock);
return expired;
}
spin_lock(&sbi->fs_lock);
if (ino->flags & AUTOFS_INF_MOUNTPOINT) {
- sb->s_root->d_mounted++;
+ spin_lock(&sb->s_root->d_lock);
+ /*
+ * If we haven't been expired away, then reset
+ * mounted status.
+ */
+ if (mnt->mnt_parent != mnt)
+ sb->s_root->d_flags |= DCACHE_MOUNTED;
+ spin_unlock(&sb->s_root->d_lock);
ino->flags &= ~AUTOFS_INF_MOUNTPOINT;
}
ino->flags &= ~AUTOFS_INF_EXPIRING;
goto fail_iput;
pipe = NULL;
- root->d_op = &autofs4_sb_dentry_operations;
+ d_set_d_op(root, &autofs4_sb_dentry_operations);
root->d_fsdata = ino;
/* Can this call block? */
#include "autofs_i.h"
+DEFINE_SPINLOCK(autofs4_lock);
+
static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *);
static int autofs4_dir_unlink(struct inode *,struct dentry *);
static int autofs4_dir_rmdir(struct inode *,struct dentry *);
* autofs file system so just let the libfs routines handle
* it.
*/
- spin_lock(&dcache_lock);
+ spin_lock(&autofs4_lock);
+ spin_lock(&dentry->d_lock);
if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
- spin_unlock(&dcache_lock);
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&autofs4_lock);
return -ENOENT;
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&autofs4_lock);
out:
return dcache_dir_open(inode, file);
/* We trigger a mount for almost all flags */
lookup_type = autofs4_need_mount(nd->flags);
spin_lock(&sbi->fs_lock);
- spin_lock(&dcache_lock);
+ spin_lock(&autofs4_lock);
+ spin_lock(&dentry->d_lock);
if (!(lookup_type || ino->flags & AUTOFS_INF_PENDING)) {
- spin_unlock(&dcache_lock);
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&autofs4_lock);
spin_unlock(&sbi->fs_lock);
goto follow;
}
*/
if (ino->flags & AUTOFS_INF_PENDING ||
(!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs))) {
- spin_unlock(&dcache_lock);
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&autofs4_lock);
spin_unlock(&sbi->fs_lock);
status = try_to_fill_dentry(dentry, nd->flags);
goto follow;
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&autofs4_lock);
spin_unlock(&sbi->fs_lock);
follow:
/*
*/
static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
{
- struct inode *dir = dentry->d_parent->d_inode;
- struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
- int oz_mode = autofs4_oz_mode(sbi);
+ struct inode *dir;
+ struct autofs_sb_info *sbi;
+ int oz_mode;
int flags = nd ? nd->flags : 0;
int status = 1;
+ if (flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ dir = dentry->d_parent->d_inode;
+ sbi = autofs4_sbi(dir->i_sb);
+ oz_mode = autofs4_oz_mode(sbi);
+
/* Pending dentry */
spin_lock(&sbi->fs_lock);
if (autofs4_ispending(dentry)) {
return 0;
/* Check for a non-mountpoint directory with no contents */
- spin_lock(&dcache_lock);
+ spin_lock(&autofs4_lock);
+ spin_lock(&dentry->d_lock);
if (S_ISDIR(dentry->d_inode->i_mode) &&
!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
DPRINTK("dentry=%p %.*s, emptydir",
dentry, dentry->d_name.len, dentry->d_name.name);
- spin_unlock(&dcache_lock);
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&autofs4_lock);
/* The daemon never causes a mount to trigger */
if (oz_mode)
return status;
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&autofs4_lock);
return 1;
}
const unsigned char *str = name->name;
struct list_head *p, *head;
- spin_lock(&dcache_lock);
+ spin_lock(&autofs4_lock);
spin_lock(&sbi->lookup_lock);
head = &sbi->active_list;
list_for_each(p, head) {
spin_lock(&active->d_lock);
/* Already gone? */
- if (atomic_read(&active->d_count) == 0)
+ if (active->d_count == 0)
goto next;
qstr = &active->d_name;
goto next;
if (d_unhashed(active)) {
- dget(active);
+ dget_dlock(active);
spin_unlock(&active->d_lock);
spin_unlock(&sbi->lookup_lock);
- spin_unlock(&dcache_lock);
+ spin_unlock(&autofs4_lock);
return active;
}
next:
spin_unlock(&active->d_lock);
}
spin_unlock(&sbi->lookup_lock);
- spin_unlock(&dcache_lock);
+ spin_unlock(&autofs4_lock);
return NULL;
}
const unsigned char *str = name->name;
struct list_head *p, *head;
- spin_lock(&dcache_lock);
+ spin_lock(&autofs4_lock);
spin_lock(&sbi->lookup_lock);
head = &sbi->expiring_list;
list_for_each(p, head) {
goto next;
if (d_unhashed(expiring)) {
- dget(expiring);
+ dget_dlock(expiring);
spin_unlock(&expiring->d_lock);
spin_unlock(&sbi->lookup_lock);
- spin_unlock(&dcache_lock);
+ spin_unlock(&autofs4_lock);
return expiring;
}
next:
spin_unlock(&expiring->d_lock);
}
spin_unlock(&sbi->lookup_lock);
- spin_unlock(&dcache_lock);
+ spin_unlock(&autofs4_lock);
return NULL;
}
* we check for the hashed dentry and return the newly
* hashed dentry.
*/
- dentry->d_op = &autofs4_root_dentry_operations;
+ d_set_d_op(dentry, &autofs4_root_dentry_operations);
/*
* And we need to ensure that the same dentry is used for
d_add(dentry, inode);
if (dir == dir->i_sb->s_root->d_inode)
- dentry->d_op = &autofs4_root_dentry_operations;
+ d_set_d_op(dentry, &autofs4_root_dentry_operations);
else
- dentry->d_op = &autofs4_dentry_operations;
+ d_set_d_op(dentry, &autofs4_dentry_operations);
dentry->d_fsdata = ino;
ino->dentry = dget(dentry);
dir->i_mtime = CURRENT_TIME;
- spin_lock(&dcache_lock);
+ spin_lock(&autofs4_lock);
autofs4_add_expiring(dentry);
spin_lock(&dentry->d_lock);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
+ spin_unlock(&autofs4_lock);
return 0;
}
if (!autofs4_oz_mode(sbi))
return -EACCES;
- spin_lock(&dcache_lock);
+ spin_lock(&autofs4_lock);
+ spin_lock(&sbi->lookup_lock);
+ spin_lock(&dentry->d_lock);
if (!list_empty(&dentry->d_subdirs)) {
- spin_unlock(&dcache_lock);
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&sbi->lookup_lock);
+ spin_unlock(&autofs4_lock);
return -ENOTEMPTY;
}
- autofs4_add_expiring(dentry);
- spin_lock(&dentry->d_lock);
+ __autofs4_add_expiring(dentry);
+ spin_unlock(&sbi->lookup_lock);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
+ spin_unlock(&autofs4_lock);
if (atomic_dec_and_test(&ino->count)) {
p_ino = autofs4_dentry_ino(dentry->d_parent);
d_add(dentry, inode);
if (dir == dir->i_sb->s_root->d_inode)
- dentry->d_op = &autofs4_root_dentry_operations;
+ d_set_d_op(dentry, &autofs4_root_dentry_operations);
else
- dentry->d_op = &autofs4_dentry_operations;
+ d_set_d_op(dentry, &autofs4_dentry_operations);
dentry->d_fsdata = ino;
ino->dentry = dget(dentry);
{
struct dentry *root = sbi->sb->s_root;
struct dentry *tmp;
- char *buf = *name;
+ char *buf;
char *p;
- int len = 0;
+ int len;
+ unsigned seq;
- spin_lock(&dcache_lock);
+rename_retry:
+ buf = *name;
+ len = 0;
+
+ seq = read_seqbegin(&rename_lock);
+ rcu_read_lock();
+ spin_lock(&autofs4_lock);
for (tmp = dentry ; tmp != root ; tmp = tmp->d_parent)
len += tmp->d_name.len + 1;
if (!len || --len > NAME_MAX) {
- spin_unlock(&dcache_lock);
+ spin_unlock(&autofs4_lock);
+ rcu_read_unlock();
+ if (read_seqretry(&rename_lock, seq))
+ goto rename_retry;
return 0;
}
p -= tmp->d_name.len;
strncpy(p, tmp->d_name.name, tmp->d_name.len);
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&autofs4_lock);
+ rcu_read_unlock();
+ if (read_seqretry(&rename_lock, seq))
+ goto rename_retry;
return len;
}
return -EIO;
}
-static int bad_inode_permission(struct inode *inode, int mask)
+static int bad_inode_permission(struct inode *inode, int mask, unsigned int flags)
{
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
+
return -EIO;
}
return &bi->vfs_inode;
}
-static void
-befs_destroy_inode(struct inode *inode)
+static void befs_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
}
+static void befs_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, befs_i_callback);
+}
+
static void init_once(void *foo)
{
struct befs_inode_info *bi = (struct befs_inode_info *) foo;
return &bi->vfs_inode;
}
-static void bfs_destroy_inode(struct inode *inode)
+static void bfs_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
}
+static void bfs_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, bfs_i_callback);
+}
+
static void init_once(void *foo)
{
struct bfs_inode_info *bi = foo;
return &ei->vfs_inode;
}
-static void bdev_destroy_inode(struct inode *inode)
+static void bdev_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
struct bdev_inode *bdi = BDEV_I(inode);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(bdev_cachep, bdi);
}
+static void bdev_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, bdev_i_callback);
+}
+
static void init_once(void *foo)
{
struct bdev_inode *ei = (struct bdev_inode *) foo;
return ret;
}
-int btrfs_check_acl(struct inode *inode, int mask)
+int btrfs_check_acl(struct inode *inode, int mask, unsigned int flags)
{
- struct posix_acl *acl;
int error = -EAGAIN;
- acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
+ if (flags & IPERM_FLAG_RCU) {
+ if (!negative_cached_acl(inode, ACL_TYPE_ACCESS))
+ error = -ECHILD;
- if (IS_ERR(acl))
- return PTR_ERR(acl);
- if (acl) {
- error = posix_acl_permission(inode, acl, mask);
- posix_acl_release(acl);
+ } else {
+ struct posix_acl *acl;
+ acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+ if (acl) {
+ error = posix_acl_permission(inode, acl, mask);
+ posix_acl_release(acl);
+ }
}
return error;
/* acl.c */
#ifdef CONFIG_BTRFS_FS_POSIX_ACL
-int btrfs_check_acl(struct inode *inode, int mask);
+int btrfs_check_acl(struct inode *inode, int mask, unsigned int flags);
#else
#define btrfs_check_acl NULL
#endif
dentry = d_obtain_alias(inode);
if (!IS_ERR(dentry))
- dentry->d_op = &btrfs_dentry_operations;
+ d_set_d_op(dentry, &btrfs_dentry_operations);
return dentry;
fail:
srcu_read_unlock(&fs_info->subvol_srcu, index);
key.offset = 0;
dentry = d_obtain_alias(btrfs_iget(root->fs_info->sb, &key, root, NULL));
if (!IS_ERR(dentry))
- dentry->d_op = &btrfs_dentry_operations;
+ d_set_d_op(dentry, &btrfs_dentry_operations);
return dentry;
fail:
btrfs_free_path(path);
int index;
int ret;
- dentry->d_op = &btrfs_dentry_operations;
+ d_set_d_op(dentry, &btrfs_dentry_operations);
if (dentry->d_name.len > BTRFS_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
return inode;
}
-static int btrfs_dentry_delete(struct dentry *dentry)
+static int btrfs_dentry_delete(const struct dentry *dentry)
{
struct btrfs_root *root;
return inode;
}
+static void btrfs_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
+ kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
+}
+
void btrfs_destroy_inode(struct inode *inode)
{
struct btrfs_ordered_extent *ordered;
inode_tree_del(inode);
btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
free:
- kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
+ call_rcu(&inode->i_rcu, btrfs_i_callback);
}
int btrfs_drop_inode(struct inode *inode)
return __set_page_dirty_nobuffers(page);
}
-static int btrfs_permission(struct inode *inode, int mask)
+static int btrfs_permission(struct inode *inode, int mask, unsigned int flags)
{
if ((BTRFS_I(inode)->flags & BTRFS_INODE_READONLY) && (mask & MAY_WRITE))
return -EACCES;
- return generic_permission(inode, mask, btrfs_check_acl);
+ return generic_permission(inode, mask, flags, btrfs_check_acl);
}
static const struct inode_operations btrfs_dir_inode_operations = {
if (dentry->d_parent == NULL || /* nfs fh_to_dentry */
ceph_snap(dentry->d_parent->d_inode) == CEPH_NOSNAP)
- dentry->d_op = &ceph_dentry_ops;
+ d_set_d_op(dentry, &ceph_dentry_ops);
else if (ceph_snap(dentry->d_parent->d_inode) == CEPH_SNAPDIR)
- dentry->d_op = &ceph_snapdir_dentry_ops;
+ d_set_d_op(dentry, &ceph_snapdir_dentry_ops);
else
- dentry->d_op = &ceph_snap_dentry_ops;
+ d_set_d_op(dentry, &ceph_snap_dentry_ops);
di = kmem_cache_alloc(ceph_dentry_cachep, GFP_NOFS | __GFP_ZERO);
if (!di)
dout("__dcache_readdir %p at %llu (last %p)\n", dir, filp->f_pos,
last);
- spin_lock(&dcache_lock);
+ spin_lock(&parent->d_lock);
/* start at beginning? */
if (filp->f_pos == 2 || last == NULL ||
fi->at_end = 1;
goto out_unlock;
}
+ spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
if (!d_unhashed(dentry) && dentry->d_inode &&
ceph_snap(dentry->d_inode) != CEPH_SNAPDIR &&
ceph_ino(dentry->d_inode) != CEPH_INO_CEPH &&
dentry->d_name.len, dentry->d_name.name, di->offset,
filp->f_pos, d_unhashed(dentry) ? " unhashed" : "",
!dentry->d_inode ? " null" : "");
+ spin_unlock(&dentry->d_lock);
p = p->prev;
dentry = list_entry(p, struct dentry, d_u.d_child);
di = ceph_dentry(dentry);
}
- atomic_inc(&dentry->d_count);
- spin_unlock(&dcache_lock);
+ dget_dlock(dentry);
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&parent->d_lock);
dout(" %llu (%llu) dentry %p %.*s %p\n", di->offset, filp->f_pos,
dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
filp->f_pos++;
- /* make sure a dentry wasn't dropped while we didn't have dcache_lock */
+ /* make sure a dentry wasn't dropped while we didn't have parent lock */
if (!ceph_i_test(dir, CEPH_I_COMPLETE)) {
dout(" lost I_COMPLETE on %p; falling back to mds\n", dir);
err = -EAGAIN;
goto out;
}
- spin_lock(&dcache_lock);
+ spin_lock(&parent->d_lock);
p = p->prev; /* advance to next dentry */
goto more;
out_unlock:
- spin_unlock(&dcache_lock);
+ spin_unlock(&parent->d_lock);
out:
if (last)
dput(last);
*/
static int ceph_d_revalidate(struct dentry *dentry, struct nameidata *nd)
{
- struct inode *dir = dentry->d_parent->d_inode;
+ struct inode *dir;
+
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ dir = dentry->d_parent->d_inode;
dout("d_revalidate %p '%.*s' inode %p offset %lld\n", dentry,
dentry->d_name.len, dentry->d_name.name, dentry->d_inode,
return &ci->vfs_inode;
}
+static void ceph_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ struct ceph_inode_info *ci = ceph_inode(inode);
+
+ INIT_LIST_HEAD(&inode->i_dentry);
+ kmem_cache_free(ceph_inode_cachep, ci);
+}
+
void ceph_destroy_inode(struct inode *inode)
{
struct ceph_inode_info *ci = ceph_inode(inode);
if (ci->i_xattrs.prealloc_blob)
ceph_buffer_put(ci->i_xattrs.prealloc_blob);
- kmem_cache_free(ceph_inode_cachep, ci);
+ call_rcu(&inode->i_rcu, ceph_i_callback);
}
di->offset = ceph_inode(inode)->i_max_offset++;
spin_unlock(&inode->i_lock);
- spin_lock(&dcache_lock);
- spin_lock(&dn->d_lock);
+ spin_lock(&dir->d_lock);
+ spin_lock_nested(&dn->d_lock, DENTRY_D_LOCK_NESTED);
list_move(&dn->d_u.d_child, &dir->d_subdirs);
dout("set_dentry_offset %p %lld (%p %p)\n", dn, di->offset,
dn->d_u.d_child.prev, dn->d_u.d_child.next);
spin_unlock(&dn->d_lock);
- spin_unlock(&dcache_lock);
+ spin_unlock(&dir->d_lock);
}
/*
} else if (realdn) {
dout("dn %p (%d) spliced with %p (%d) "
"inode %p ino %llx.%llx\n",
- dn, atomic_read(&dn->d_count),
- realdn, atomic_read(&realdn->d_count),
+ dn, dn->d_count,
+ realdn, realdn->d_count,
realdn->d_inode, ceph_vinop(realdn->d_inode));
dput(dn);
dn = realdn;
goto retry_lookup;
} else {
/* reorder parent's d_subdirs */
- spin_lock(&dcache_lock);
- spin_lock(&dn->d_lock);
+ spin_lock(&parent->d_lock);
+ spin_lock_nested(&dn->d_lock, DENTRY_D_LOCK_NESTED);
list_move(&dn->d_u.d_child, &parent->d_subdirs);
spin_unlock(&dn->d_lock);
- spin_unlock(&dcache_lock);
+ spin_unlock(&parent->d_lock);
}
di = dn->d_fsdata;
* Check inode permissions. We verify we have a valid value for
* the AUTH cap, then call the generic handler.
*/
-int ceph_permission(struct inode *inode, int mask)
+int ceph_permission(struct inode *inode, int mask, unsigned int flags)
{
- int err = ceph_do_getattr(inode, CEPH_CAP_AUTH_SHARED);
+ int err;
+
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
+
+ err = ceph_do_getattr(inode, CEPH_CAP_AUTH_SHARED);
if (!err)
- err = generic_permission(inode, mask, NULL);
+ err = generic_permission(inode, mask, flags, NULL);
return err;
}
*base = ceph_ino(temp->d_inode);
*plen = len;
dout("build_path on %p %d built %llx '%.*s'\n",
- dentry, atomic_read(&dentry->d_count), *base, len, path);
+ dentry, dentry->d_count, *base, len, path);
return path;
}
extern void ceph_queue_writeback(struct inode *inode);
extern int ceph_do_getattr(struct inode *inode, int mask);
-extern int ceph_permission(struct inode *inode, int mask);
+extern int ceph_permission(struct inode *inode, int mask, unsigned int flags);
extern int ceph_setattr(struct dentry *dentry, struct iattr *attr);
extern int ceph_getattr(struct vfsmount *mnt, struct dentry *dentry,
struct kstat *stat);
return 0;
}
-static int cifs_permission(struct inode *inode, int mask)
+static int cifs_permission(struct inode *inode, int mask, unsigned int flags)
{
struct cifs_sb_info *cifs_sb;
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
+
cifs_sb = CIFS_SB(inode->i_sb);
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_PERM) {
on the client (above and beyond ACL on servers) for
servers which do not support setting and viewing mode bits,
so allowing client to check permissions is useful */
- return generic_permission(inode, mask, NULL);
+ return generic_permission(inode, mask, flags, NULL);
}
static struct kmem_cache *cifs_inode_cachep;
return &cifs_inode->vfs_inode;
}
+static void cifs_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
+ kmem_cache_free(cifs_inode_cachep, CIFS_I(inode));
+}
+
static void
cifs_destroy_inode(struct inode *inode)
{
- kmem_cache_free(cifs_inode_cachep, CIFS_I(inode));
+ call_rcu(&inode->i_rcu, cifs_i_callback);
}
static void
struct inode *newinode)
{
if (tcon->nocase)
- direntry->d_op = &cifs_ci_dentry_ops;
+ d_set_d_op(direntry, &cifs_ci_dentry_ops);
else
- direntry->d_op = &cifs_dentry_ops;
+ d_set_d_op(direntry, &cifs_dentry_ops);
d_instantiate(direntry, newinode);
}
rc = cifs_get_inode_info_unix(&newinode, full_path,
inode->i_sb, xid);
if (pTcon->nocase)
- direntry->d_op = &cifs_ci_dentry_ops;
+ d_set_d_op(direntry, &cifs_ci_dentry_ops);
else
- direntry->d_op = &cifs_dentry_ops;
+ d_set_d_op(direntry, &cifs_dentry_ops);
if (rc == 0)
d_instantiate(direntry, newinode);
if ((rc == 0) && (newInode != NULL)) {
if (pTcon->nocase)
- direntry->d_op = &cifs_ci_dentry_ops;
+ d_set_d_op(direntry, &cifs_ci_dentry_ops);
else
- direntry->d_op = &cifs_dentry_ops;
+ d_set_d_op(direntry, &cifs_dentry_ops);
d_add(direntry, newInode);
if (posix_open) {
filp = lookup_instantiate_filp(nd, direntry,
rc = 0;
direntry->d_time = jiffies;
if (pTcon->nocase)
- direntry->d_op = &cifs_ci_dentry_ops;
+ d_set_d_op(direntry, &cifs_ci_dentry_ops);
else
- direntry->d_op = &cifs_dentry_ops;
+ d_set_d_op(direntry, &cifs_dentry_ops);
d_add(direntry, NULL);
/* if it was once a directory (but how can we tell?) we could do
shrink_dcache_parent(direntry); */
static int
cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
{
- int isValid = 1;
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
if (direntry->d_inode) {
if (cifs_revalidate_dentry(direntry))
return 0;
- } else {
- cFYI(1, "neg dentry 0x%p name = %s",
- direntry, direntry->d_name.name);
- if (time_after(jiffies, direntry->d_time + HZ) ||
- !lookupCacheEnabled) {
- d_drop(direntry);
- isValid = 0;
- }
+ else
+ return 1;
}
- return isValid;
+ /*
+ * This may be nfsd (or something), anyway, we can't see the
+ * intent of this. So, since this can be for creation, drop it.
+ */
+ if (!nd)
+ return 0;
+
+ /*
+ * Drop the negative dentry, in order to make sure to use the
+ * case sensitive name which is specified by user if this is
+ * for creation.
+ */
+ if (!(nd->flags & (LOOKUP_CONTINUE | LOOKUP_PARENT))) {
+ if (nd->flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
+ return 0;
+ }
+
+ if (time_after(jiffies, direntry->d_time + HZ) || !lookupCacheEnabled)
+ return 0;
+
+ return 1;
}
/* static int cifs_d_delete(struct dentry *direntry)
/* d_delete: cifs_d_delete, */ /* not needed except for debugging */
};
-static int cifs_ci_hash(struct dentry *dentry, struct qstr *q)
+static int cifs_ci_hash(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *q)
{
- struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
+ struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
unsigned long hash;
int i;
return 0;
}
-static int cifs_ci_compare(struct dentry *dentry, struct qstr *a,
- struct qstr *b)
+static int cifs_ci_compare(const struct dentry *parent,
+ const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name)
{
- struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
-
- if ((a->len == b->len) &&
- (nls_strnicmp(codepage, a->name, b->name, a->len) == 0)) {
- /*
- * To preserve case, don't let an existing negative dentry's
- * case take precedence. If a is not a negative dentry, this
- * should have no side effects
- */
- memcpy((void *)a->name, b->name, a->len);
+ struct nls_table *codepage = CIFS_SB(pinode->i_sb)->local_nls;
+
+ if ((name->len == len) &&
+ (nls_strnicmp(codepage, name->name, str, len) == 0))
return 0;
- }
return 1;
}
{
struct dentry *dentry;
- spin_lock(&dcache_lock);
+ spin_lock(&inode->i_lock);
list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
if (!d_unhashed(dentry) || IS_ROOT(dentry)) {
- spin_unlock(&dcache_lock);
+ spin_unlock(&inode->i_lock);
return true;
}
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&inode->i_lock);
return false;
}
to set uid/gid */
inc_nlink(inode);
if (pTcon->nocase)
- direntry->d_op = &cifs_ci_dentry_ops;
+ d_set_d_op(direntry, &cifs_ci_dentry_ops);
else
- direntry->d_op = &cifs_dentry_ops;
+ d_set_d_op(direntry, &cifs_dentry_ops);
cifs_unix_basic_to_fattr(&fattr, pInfo, cifs_sb);
cifs_fill_uniqueid(inode->i_sb, &fattr);
inode->i_sb, xid, NULL);
if (pTcon->nocase)
- direntry->d_op = &cifs_ci_dentry_ops;
+ d_set_d_op(direntry, &cifs_ci_dentry_ops);
else
- direntry->d_op = &cifs_dentry_ops;
+ d_set_d_op(direntry, &cifs_dentry_ops);
d_instantiate(direntry, newinode);
/* setting nlink not necessary except in cases where we
* failed to get it from the server or was set bogus */
rc);
} else {
if (pTcon->nocase)
- direntry->d_op = &cifs_ci_dentry_ops;
+ d_set_d_op(direntry, &cifs_ci_dentry_ops);
else
- direntry->d_op = &cifs_dentry_ops;
+ d_set_d_op(direntry, &cifs_dentry_ops);
d_instantiate(direntry, newinode);
}
}
cFYI(1, "For %s", name->name);
if (parent->d_op && parent->d_op->d_hash)
- parent->d_op->d_hash(parent, name);
+ parent->d_op->d_hash(parent, parent->d_inode, name);
else
name->hash = full_name_hash(name->name, name->len);
}
if (cifs_sb_master_tcon(CIFS_SB(sb))->nocase)
- dentry->d_op = &cifs_ci_dentry_ops;
+ d_set_d_op(dentry, &cifs_ci_dentry_ops);
else
- dentry->d_op = &cifs_dentry_ops;
+ d_set_d_op(dentry, &cifs_dentry_ops);
alias = d_materialise_unique(dentry, inode);
if (alias != NULL) {
struct list_head *child;
struct dentry *de;
- spin_lock(&dcache_lock);
+ spin_lock(&parent->d_lock);
list_for_each(child, &parent->d_subdirs)
{
de = list_entry(child, struct dentry, d_u.d_child);
continue;
coda_flag_inode(de->d_inode, flag);
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&parent->d_lock);
return;
}
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/spinlock.h>
+#include <linux/namei.h>
#include <asm/uaccess.h>
/* dentry ops */
static int coda_dentry_revalidate(struct dentry *de, struct nameidata *nd);
-static int coda_dentry_delete(struct dentry *);
+static int coda_dentry_delete(const struct dentry *);
/* support routines */
static int coda_venus_readdir(struct file *coda_file, void *buf,
return ERR_PTR(error);
exit:
- entry->d_op = &coda_dentry_operations;
+ d_set_d_op(entry, &coda_dentry_operations);
if (inode && (type & CODA_NOCACHE))
coda_flag_inode(inode, C_VATTR | C_PURGE);
}
-int coda_permission(struct inode *inode, int mask)
+int coda_permission(struct inode *inode, int mask, unsigned int flags)
{
int error;
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
+
mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
if (!mask)
/* called when a cache lookup succeeds */
static int coda_dentry_revalidate(struct dentry *de, struct nameidata *nd)
{
- struct inode *inode = de->d_inode;
+ struct inode *inode;
struct coda_inode_info *cii;
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ inode = de->d_inode;
if (!inode || coda_isroot(inode))
goto out;
if (is_bad_inode(inode))
if (cii->c_flags & C_FLUSH)
coda_flag_inode_children(inode, C_FLUSH);
- if (atomic_read(&de->d_count) > 1)
+ if (de->d_count > 1)
/* pretend it's valid, but don't change the flags */
goto out;
* This is the callback from dput() when d_count is going to 0.
* We use this to unhash dentries with bad inodes.
*/
-static int coda_dentry_delete(struct dentry * dentry)
+static int coda_dentry_delete(const struct dentry * dentry)
{
int flags;
return &ei->vfs_inode;
}
-static void coda_destroy_inode(struct inode *inode)
+static void coda_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(coda_inode_cachep, ITOC(inode));
}
+static void coda_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, coda_i_callback);
+}
+
static void init_once(void *foo)
{
struct coda_inode_info *ei = (struct coda_inode_info *) foo;
#include <linux/coda_psdev.h>
/* pioctl ops */
-static int coda_ioctl_permission(struct inode *inode, int mask);
+static int coda_ioctl_permission(struct inode *inode, int mask, unsigned int flags);
static long coda_pioctl(struct file *filp, unsigned int cmd,
unsigned long user_data);
};
/* the coda pioctl inode ops */
-static int coda_ioctl_permission(struct inode *inode, int mask)
+static int coda_ioctl_permission(struct inode *inode, int mask, unsigned int flags)
{
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
return (mask & MAY_EXEC) ? -EACCES : 0;
}
{
struct config_item * item = NULL;
- spin_lock(&dcache_lock);
+ spin_lock(&dentry->d_lock);
if (!d_unhashed(dentry)) {
struct configfs_dirent * sd = dentry->d_fsdata;
if (sd->s_type & CONFIGFS_ITEM_LINK) {
} else
item = config_item_get(sd->s_element);
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&dentry->d_lock);
return item;
}
* We _must_ delete our dentries on last dput, as the chain-to-parent
* behavior is required to clear the parents of default_groups.
*/
-static int configfs_d_delete(struct dentry *dentry)
+static int configfs_d_delete(const struct dentry *dentry)
{
return 1;
}
sd->s_mode = mode;
sd->s_dentry = dentry;
- if (dentry) {
+ if (dentry)
dentry->d_fsdata = configfs_get(sd);
- dentry->d_op = &configfs_dentry_ops;
- }
return 0;
}
error = configfs_create(d, mode, init_dir);
if (!error) {
inc_nlink(p->d_inode);
- (d)->d_op = &configfs_dentry_ops;
} else {
struct configfs_dirent *sd = d->d_fsdata;
if (sd) {
CONFIGFS_ITEM_LINK);
if (!err) {
err = configfs_create(dentry, mode, init_symlink);
- if (!err)
- dentry->d_op = &configfs_dentry_ops;
- else {
+ if (err) {
struct configfs_dirent *sd = dentry->d_fsdata;
if (sd) {
spin_lock(&configfs_dirent_lock);
if (d->d_inode)
simple_rmdir(parent->d_inode,d);
- pr_debug(" o %s removing done (%d)\n",d->d_name.name,
- atomic_read(&d->d_count));
+ pr_debug(" o %s removing done (%d)\n",d->d_name.name, d->d_count);
dput(parent);
}
return error;
}
- dentry->d_op = &configfs_dentry_ops;
+ d_set_d_op(dentry, &configfs_dentry_ops);
d_rehash(dentry);
return 0;
* If it doesn't exist and it isn't a NOT_PINNED item,
* it must be negative.
*/
- return simple_lookup(dir, dentry, nd);
+ if (dentry->d_name.len > NAME_MAX)
+ return ERR_PTR(-ENAMETOOLONG);
+ d_set_d_op(dentry, &configfs_dentry_ops);
+ d_add(dentry, NULL);
+ return NULL;
}
out:
ret = -ENOMEM;
child = d_alloc(parent, &name);
if (child) {
+ d_set_d_op(child, &configfs_dentry_ops);
d_add(child, NULL);
ret = configfs_attach_group(&parent_group->cg_item,
err = -ENOMEM;
dentry = d_alloc(configfs_sb->s_root, &name);
if (dentry) {
+ d_set_d_op(dentry, &configfs_dentry_ops);
d_add(dentry, NULL);
err = configfs_attach_group(sd->s_element, &group->cg_item,
struct dentry * dentry = sd->s_dentry;
if (dentry) {
- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
if (!(d_unhashed(dentry) && dentry->d_inode)) {
- dget_locked(dentry);
+ dget_dlock(dentry);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
simple_unlink(parent->d_inode, dentry);
- } else {
+ } else
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
- }
}
}
#include <linux/bootmem.h>
#include <linux/fs_struct.h>
#include <linux/hardirq.h>
+#include <linux/bit_spinlock.h>
+#include <linux/rculist_bl.h>
#include "internal.h"
+/*
+ * Usage:
+ * dcache->d_inode->i_lock protects:
+ * - i_dentry, d_alias, d_inode of aliases
+ * dcache_hash_bucket lock protects:
+ * - the dcache hash table
+ * s_anon bl list spinlock protects:
+ * - the s_anon list (see __d_drop)
+ * dcache_lru_lock protects:
+ * - the dcache lru lists and counters
+ * d_lock protects:
+ * - d_flags
+ * - d_name
+ * - d_lru
+ * - d_count
+ * - d_unhashed()
+ * - d_parent and d_subdirs
+ * - childrens' d_child and d_parent
+ * - d_alias, d_inode
+ *
+ * Ordering:
+ * dentry->d_inode->i_lock
+ * dentry->d_lock
+ * dcache_lru_lock
+ * dcache_hash_bucket lock
+ * s_anon lock
+ *
+ * If there is an ancestor relationship:
+ * dentry->d_parent->...->d_parent->d_lock
+ * ...
+ * dentry->d_parent->d_lock
+ * dentry->d_lock
+ *
+ * If no ancestor relationship:
+ * if (dentry1 < dentry2)
+ * dentry1->d_lock
+ * dentry2->d_lock
+ */
int sysctl_vfs_cache_pressure __read_mostly = 100;
EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure);
- __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lock);
+static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lru_lock);
__cacheline_aligned_in_smp DEFINE_SEQLOCK(rename_lock);
-EXPORT_SYMBOL(dcache_lock);
+EXPORT_SYMBOL(rename_lock);
static struct kmem_cache *dentry_cache __read_mostly;
-#define DNAME_INLINE_LEN (sizeof(struct dentry)-offsetof(struct dentry,d_iname))
-
/*
* This is the single most critical data structure when it comes
* to the dcache: the hashtable for lookups. Somebody should try
static unsigned int d_hash_mask __read_mostly;
static unsigned int d_hash_shift __read_mostly;
-static struct hlist_head *dentry_hashtable __read_mostly;
+
+struct dcache_hash_bucket {
+ struct hlist_bl_head head;
+};
+static struct dcache_hash_bucket *dentry_hashtable __read_mostly;
+
+static inline struct dcache_hash_bucket *d_hash(struct dentry *parent,
+ unsigned long hash)
+{
+ hash += ((unsigned long) parent ^ GOLDEN_RATIO_PRIME) / L1_CACHE_BYTES;
+ hash = hash ^ ((hash ^ GOLDEN_RATIO_PRIME) >> D_HASHBITS);
+ return dentry_hashtable + (hash & D_HASHMASK);
+}
+
+static inline void spin_lock_bucket(struct dcache_hash_bucket *b)
+{
+ bit_spin_lock(0, (unsigned long *)&b->head.first);
+}
+
+static inline void spin_unlock_bucket(struct dcache_hash_bucket *b)
+{
+ __bit_spin_unlock(0, (unsigned long *)&b->head.first);
+}
/* Statistics gathering. */
struct dentry_stat_t dentry_stat = {
.age_limit = 45,
};
-static struct percpu_counter nr_dentry __cacheline_aligned_in_smp;
-static struct percpu_counter nr_dentry_unused __cacheline_aligned_in_smp;
+static DEFINE_PER_CPU(unsigned int, nr_dentry);
#if defined(CONFIG_SYSCTL) && defined(CONFIG_PROC_FS)
+static int get_nr_dentry(void)
+{
+ int i;
+ int sum = 0;
+ for_each_possible_cpu(i)
+ sum += per_cpu(nr_dentry, i);
+ return sum < 0 ? 0 : sum;
+}
+
int proc_nr_dentry(ctl_table *table, int write, void __user *buffer,
size_t *lenp, loff_t *ppos)
{
- dentry_stat.nr_dentry = percpu_counter_sum_positive(&nr_dentry);
- dentry_stat.nr_unused = percpu_counter_sum_positive(&nr_dentry_unused);
+ dentry_stat.nr_dentry = get_nr_dentry();
return proc_dointvec(table, write, buffer, lenp, ppos);
}
#endif
}
/*
- * no dcache_lock, please.
+ * no locks, please.
*/
static void d_free(struct dentry *dentry)
{
- percpu_counter_dec(&nr_dentry);
+ BUG_ON(dentry->d_count);
+ this_cpu_dec(nr_dentry);
if (dentry->d_op && dentry->d_op->d_release)
dentry->d_op->d_release(dentry);
/* if dentry was never inserted into hash, immediate free is OK */
- if (hlist_unhashed(&dentry->d_hash))
+ if (hlist_bl_unhashed(&dentry->d_hash))
__d_free(&dentry->d_u.d_rcu);
else
call_rcu(&dentry->d_u.d_rcu, __d_free);
}
+/**
+ * dentry_rcuwalk_barrier - invalidate in-progress rcu-walk lookups
+ * After this call, in-progress rcu-walk path lookup will fail. This
+ * should be called after unhashing, and after changing d_inode (if
+ * the dentry has not already been unhashed).
+ */
+static inline void dentry_rcuwalk_barrier(struct dentry *dentry)
+{
+ assert_spin_locked(&dentry->d_lock);
+ /* Go through a barrier */
+ write_seqcount_barrier(&dentry->d_seq);
+}
+
/*
* Release the dentry's inode, using the filesystem
- * d_iput() operation if defined.
+ * d_iput() operation if defined. Dentry has no refcount
+ * and is unhashed.
*/
static void dentry_iput(struct dentry * dentry)
__releases(dentry->d_lock)
- __releases(dcache_lock)
+ __releases(dentry->d_inode->i_lock)
{
struct inode *inode = dentry->d_inode;
if (inode) {
dentry->d_inode = NULL;
list_del_init(&dentry->d_alias);
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
+ spin_unlock(&inode->i_lock);
if (!inode->i_nlink)
fsnotify_inoderemove(inode);
if (dentry->d_op && dentry->d_op->d_iput)
iput(inode);
} else {
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
}
}
/*
- * dentry_lru_(add|del|move_tail) must be called with dcache_lock held.
+ * Release the dentry's inode, using the filesystem
+ * d_iput() operation if defined. dentry remains in-use.
+ */
+static void dentry_unlink_inode(struct dentry * dentry)
+ __releases(dentry->d_lock)
+ __releases(dentry->d_inode->i_lock)
+{
+ struct inode *inode = dentry->d_inode;
+ dentry->d_inode = NULL;
+ list_del_init(&dentry->d_alias);
+ dentry_rcuwalk_barrier(dentry);
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&inode->i_lock);
+ if (!inode->i_nlink)
+ fsnotify_inoderemove(inode);
+ if (dentry->d_op && dentry->d_op->d_iput)
+ dentry->d_op->d_iput(dentry, inode);
+ else
+ iput(inode);
+}
+
+/*
+ * dentry_lru_(add|del|move_tail) must be called with d_lock held.
*/
static void dentry_lru_add(struct dentry *dentry)
{
if (list_empty(&dentry->d_lru)) {
+ spin_lock(&dcache_lru_lock);
list_add(&dentry->d_lru, &dentry->d_sb->s_dentry_lru);
dentry->d_sb->s_nr_dentry_unused++;
- percpu_counter_inc(&nr_dentry_unused);
+ dentry_stat.nr_unused++;
+ spin_unlock(&dcache_lru_lock);
}
}
+static void __dentry_lru_del(struct dentry *dentry)
+{
+ list_del_init(&dentry->d_lru);
+ dentry->d_sb->s_nr_dentry_unused--;
+ dentry_stat.nr_unused--;
+}
+
static void dentry_lru_del(struct dentry *dentry)
{
if (!list_empty(&dentry->d_lru)) {
- list_del_init(&dentry->d_lru);
- dentry->d_sb->s_nr_dentry_unused--;
- percpu_counter_dec(&nr_dentry_unused);
+ spin_lock(&dcache_lru_lock);
+ __dentry_lru_del(dentry);
+ spin_unlock(&dcache_lru_lock);
}
}
static void dentry_lru_move_tail(struct dentry *dentry)
{
+ spin_lock(&dcache_lru_lock);
if (list_empty(&dentry->d_lru)) {
list_add_tail(&dentry->d_lru, &dentry->d_sb->s_dentry_lru);
dentry->d_sb->s_nr_dentry_unused++;
- percpu_counter_inc(&nr_dentry_unused);
+ dentry_stat.nr_unused++;
} else {
list_move_tail(&dentry->d_lru, &dentry->d_sb->s_dentry_lru);
}
+ spin_unlock(&dcache_lru_lock);
}
/**
* The dentry must already be unhashed and removed from the LRU.
*
* If this is the root of the dentry tree, return NULL.
+ *
+ * dentry->d_lock and parent->d_lock must be held by caller, and are dropped by
+ * d_kill.
*/
-static struct dentry *d_kill(struct dentry *dentry)
+static struct dentry *d_kill(struct dentry *dentry, struct dentry *parent)
__releases(dentry->d_lock)
- __releases(dcache_lock)
+ __releases(parent->d_lock)
+ __releases(dentry->d_inode->i_lock)
{
- struct dentry *parent;
-
+ dentry->d_parent = NULL;
list_del(&dentry->d_u.d_child);
- /*drops the locks, at that point nobody can reach this dentry */
+ if (parent)
+ spin_unlock(&parent->d_lock);
dentry_iput(dentry);
+ /*
+ * dentry_iput drops the locks, at which point nobody (except
+ * transient RCU lookups) can reach this dentry.
+ */
+ d_free(dentry);
+ return parent;
+}
+
+/**
+ * d_drop - drop a dentry
+ * @dentry: dentry to drop
+ *
+ * d_drop() unhashes the entry from the parent dentry hashes, so that it won't
+ * be found through a VFS lookup any more. Note that this is different from
+ * deleting the dentry - d_delete will try to mark the dentry negative if
+ * possible, giving a successful _negative_ lookup, while d_drop will
+ * just make the cache lookup fail.
+ *
+ * d_drop() is used mainly for stuff that wants to invalidate a dentry for some
+ * reason (NFS timeouts or autofs deletes).
+ *
+ * __d_drop requires dentry->d_lock.
+ */
+void __d_drop(struct dentry *dentry)
+{
+ if (!(dentry->d_flags & DCACHE_UNHASHED)) {
+ if (unlikely(dentry->d_flags & DCACHE_DISCONNECTED)) {
+ bit_spin_lock(0,
+ (unsigned long *)&dentry->d_sb->s_anon.first);
+ dentry->d_flags |= DCACHE_UNHASHED;
+ hlist_bl_del_init(&dentry->d_hash);
+ __bit_spin_unlock(0,
+ (unsigned long *)&dentry->d_sb->s_anon.first);
+ } else {
+ struct dcache_hash_bucket *b;
+ b = d_hash(dentry->d_parent, dentry->d_name.hash);
+ spin_lock_bucket(b);
+ /*
+ * We may not actually need to put DCACHE_UNHASHED
+ * manipulations under the hash lock, but follow
+ * the principle of least surprise.
+ */
+ dentry->d_flags |= DCACHE_UNHASHED;
+ hlist_bl_del_rcu(&dentry->d_hash);
+ spin_unlock_bucket(b);
+ dentry_rcuwalk_barrier(dentry);
+ }
+ }
+}
+EXPORT_SYMBOL(__d_drop);
+
+void d_drop(struct dentry *dentry)
+{
+ spin_lock(&dentry->d_lock);
+ __d_drop(dentry);
+ spin_unlock(&dentry->d_lock);
+}
+EXPORT_SYMBOL(d_drop);
+
+/*
+ * Finish off a dentry we've decided to kill.
+ * dentry->d_lock must be held, returns with it unlocked.
+ * If ref is non-zero, then decrement the refcount too.
+ * Returns dentry requiring refcount drop, or NULL if we're done.
+ */
+static inline struct dentry *dentry_kill(struct dentry *dentry, int ref)
+ __releases(dentry->d_lock)
+{
+ struct inode *inode;
+ struct dentry *parent;
+
+ inode = dentry->d_inode;
+ if (inode && !spin_trylock(&inode->i_lock)) {
+relock:
+ spin_unlock(&dentry->d_lock);
+ cpu_relax();
+ return dentry; /* try again with same dentry */
+ }
if (IS_ROOT(dentry))
parent = NULL;
else
parent = dentry->d_parent;
- d_free(dentry);
- return parent;
+ if (parent && !spin_trylock(&parent->d_lock)) {
+ if (inode)
+ spin_unlock(&inode->i_lock);
+ goto relock;
+ }
+
+ if (ref)
+ dentry->d_count--;
+ /* if dentry was on the d_lru list delete it from there */
+ dentry_lru_del(dentry);
+ /* if it was on the hash then remove it */
+ __d_drop(dentry);
+ return d_kill(dentry, parent);
}
/*
* call the dentry unlink method as well as removing it from the queues and
* releasing its resources. If the parent dentries were scheduled for release
* they too may now get deleted.
- *
- * no dcache lock, please.
*/
-
void dput(struct dentry *dentry)
{
if (!dentry)
return;
repeat:
- if (atomic_read(&dentry->d_count) == 1)
+ if (dentry->d_count == 1)
might_sleep();
- if (!atomic_dec_and_lock(&dentry->d_count, &dcache_lock))
- return;
-
spin_lock(&dentry->d_lock);
- if (atomic_read(&dentry->d_count)) {
+ BUG_ON(!dentry->d_count);
+ if (dentry->d_count > 1) {
+ dentry->d_count--;
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
return;
}
- /*
- * AV: ->d_delete() is _NOT_ allowed to block now.
- */
- if (dentry->d_op && dentry->d_op->d_delete) {
+ if (dentry->d_flags & DCACHE_OP_DELETE) {
if (dentry->d_op->d_delete(dentry))
- goto unhash_it;
+ goto kill_it;
}
/* Unreachable? Get rid of it */
dentry->d_flags |= DCACHE_REFERENCED;
dentry_lru_add(dentry);
- spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
+ dentry->d_count--;
+ spin_unlock(&dentry->d_lock);
return;
-unhash_it:
- __d_drop(dentry);
kill_it:
- /* if dentry was on the d_lru list delete it from there */
- dentry_lru_del(dentry);
- dentry = d_kill(dentry);
+ dentry = dentry_kill(dentry, 1);
if (dentry)
goto repeat;
}
/*
* If it's already been dropped, return OK.
*/
- spin_lock(&dcache_lock);
+ spin_lock(&dentry->d_lock);
if (d_unhashed(dentry)) {
- spin_unlock(&dcache_lock);
+ spin_unlock(&dentry->d_lock);
return 0;
}
/*
* to get rid of unused child entries.
*/
if (!list_empty(&dentry->d_subdirs)) {
- spin_unlock(&dcache_lock);
+ spin_unlock(&dentry->d_lock);
shrink_dcache_parent(dentry);
- spin_lock(&dcache_lock);
+ spin_lock(&dentry->d_lock);
}
/*
* we might still populate it if it was a
* working directory or similar).
*/
- spin_lock(&dentry->d_lock);
- if (atomic_read(&dentry->d_count) > 1) {
+ if (dentry->d_count > 1) {
if (dentry->d_inode && S_ISDIR(dentry->d_inode->i_mode)) {
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
return -EBUSY;
}
}
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
return 0;
}
EXPORT_SYMBOL(d_invalidate);
-/* This should be called _only_ with dcache_lock held */
-static inline struct dentry * __dget_locked(struct dentry *dentry)
+/* This must be called with d_lock held */
+static inline void __dget_dlock(struct dentry *dentry)
{
- atomic_inc(&dentry->d_count);
- dentry_lru_del(dentry);
- return dentry;
+ dentry->d_count++;
}
-struct dentry * dget_locked(struct dentry *dentry)
+static inline void __dget(struct dentry *dentry)
{
- return __dget_locked(dentry);
+ spin_lock(&dentry->d_lock);
+ __dget_dlock(dentry);
+ spin_unlock(&dentry->d_lock);
+}
+
+struct dentry *dget_parent(struct dentry *dentry)
+{
+ struct dentry *ret;
+
+repeat:
+ /*
+ * Don't need rcu_dereference because we re-check it was correct under
+ * the lock.
+ */
+ rcu_read_lock();
+ ret = dentry->d_parent;
+ if (!ret) {
+ rcu_read_unlock();
+ goto out;
+ }
+ spin_lock(&ret->d_lock);
+ if (unlikely(ret != dentry->d_parent)) {
+ spin_unlock(&ret->d_lock);
+ rcu_read_unlock();
+ goto repeat;
+ }
+ rcu_read_unlock();
+ BUG_ON(!ret->d_count);
+ ret->d_count++;
+ spin_unlock(&ret->d_lock);
+out:
+ return ret;
}
-EXPORT_SYMBOL(dget_locked);
+EXPORT_SYMBOL(dget_parent);
/**
* d_find_alias - grab a hashed alias of inode
* any other hashed alias over that one unless @want_discon is set,
* in which case only return an IS_ROOT, DCACHE_DISCONNECTED alias.
*/
-
-static struct dentry * __d_find_alias(struct inode *inode, int want_discon)
+static struct dentry *__d_find_alias(struct inode *inode, int want_discon)
{
- struct list_head *head, *next, *tmp;
- struct dentry *alias, *discon_alias=NULL;
+ struct dentry *alias, *discon_alias;
- head = &inode->i_dentry;
- next = inode->i_dentry.next;
- while (next != head) {
- tmp = next;
- next = tmp->next;
- prefetch(next);
- alias = list_entry(tmp, struct dentry, d_alias);
+again:
+ discon_alias = NULL;
+ list_for_each_entry(alias, &inode->i_dentry, d_alias) {
+ spin_lock(&alias->d_lock);
if (S_ISDIR(inode->i_mode) || !d_unhashed(alias)) {
if (IS_ROOT(alias) &&
- (alias->d_flags & DCACHE_DISCONNECTED))
+ (alias->d_flags & DCACHE_DISCONNECTED)) {
discon_alias = alias;
- else if (!want_discon) {
- __dget_locked(alias);
+ } else if (!want_discon) {
+ __dget_dlock(alias);
+ spin_unlock(&alias->d_lock);
+ return alias;
+ }
+ }
+ spin_unlock(&alias->d_lock);
+ }
+ if (discon_alias) {
+ alias = discon_alias;
+ spin_lock(&alias->d_lock);
+ if (S_ISDIR(inode->i_mode) || !d_unhashed(alias)) {
+ if (IS_ROOT(alias) &&
+ (alias->d_flags & DCACHE_DISCONNECTED)) {
+ __dget_dlock(alias);
+ spin_unlock(&alias->d_lock);
return alias;
}
}
+ spin_unlock(&alias->d_lock);
+ goto again;
}
- if (discon_alias)
- __dget_locked(discon_alias);
- return discon_alias;
+ return NULL;
}
-struct dentry * d_find_alias(struct inode *inode)
+struct dentry *d_find_alias(struct inode *inode)
{
struct dentry *de = NULL;
if (!list_empty(&inode->i_dentry)) {
- spin_lock(&dcache_lock);
+ spin_lock(&inode->i_lock);
de = __d_find_alias(inode, 0);
- spin_unlock(&dcache_lock);
+ spin_unlock(&inode->i_lock);
}
return de;
}
{
struct dentry *dentry;
restart:
- spin_lock(&dcache_lock);
+ spin_lock(&inode->i_lock);
list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
spin_lock(&dentry->d_lock);
- if (!atomic_read(&dentry->d_count)) {
- __dget_locked(dentry);
+ if (!dentry->d_count) {
+ __dget_dlock(dentry);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
+ spin_unlock(&inode->i_lock);
dput(dentry);
goto restart;
}
spin_unlock(&dentry->d_lock);
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&inode->i_lock);
}
EXPORT_SYMBOL(d_prune_aliases);
/*
- * Throw away a dentry - free the inode, dput the parent. This requires that
- * the LRU list has already been removed.
+ * Try to throw away a dentry - free the inode, dput the parent.
+ * Requires dentry->d_lock is held, and dentry->d_count == 0.
+ * Releases dentry->d_lock.
*
- * Try to prune ancestors as well. This is necessary to prevent
- * quadratic behavior of shrink_dcache_parent(), but is also expected
- * to be beneficial in reducing dentry cache fragmentation.
+ * This may fail if locks cannot be acquired no problem, just try again.
*/
-static void prune_one_dentry(struct dentry * dentry)
+static void try_prune_one_dentry(struct dentry *dentry)
__releases(dentry->d_lock)
- __releases(dcache_lock)
- __acquires(dcache_lock)
{
- __d_drop(dentry);
- dentry = d_kill(dentry);
+ struct dentry *parent;
+ parent = dentry_kill(dentry, 0);
/*
- * Prune ancestors. Locking is simpler than in dput(),
- * because dcache_lock needs to be taken anyway.
+ * If dentry_kill returns NULL, we have nothing more to do.
+ * if it returns the same dentry, trylocks failed. In either
+ * case, just loop again.
+ *
+ * Otherwise, we need to prune ancestors too. This is necessary
+ * to prevent quadratic behavior of shrink_dcache_parent(), but
+ * is also expected to be beneficial in reducing dentry cache
+ * fragmentation.
*/
- spin_lock(&dcache_lock);
+ if (!parent)
+ return;
+ if (parent == dentry)
+ return;
+
+ /* Prune ancestors. */
+ dentry = parent;
while (dentry) {
- if (!atomic_dec_and_lock(&dentry->d_count, &dentry->d_lock))
+ spin_lock(&dentry->d_lock);
+ if (dentry->d_count > 1) {
+ dentry->d_count--;
+ spin_unlock(&dentry->d_lock);
return;
-
- if (dentry->d_op && dentry->d_op->d_delete)
- dentry->d_op->d_delete(dentry);
- dentry_lru_del(dentry);
- __d_drop(dentry);
- dentry = d_kill(dentry);
- spin_lock(&dcache_lock);
+ }
+ dentry = dentry_kill(dentry, 1);
}
}
{
struct dentry *dentry;
- while (!list_empty(list)) {
- dentry = list_entry(list->prev, struct dentry, d_lru);
- dentry_lru_del(dentry);
+ rcu_read_lock();
+ for (;;) {
+ dentry = list_entry_rcu(list->prev, struct dentry, d_lru);
+ if (&dentry->d_lru == list)
+ break; /* empty */
+ spin_lock(&dentry->d_lock);
+ if (dentry != list_entry(list->prev, struct dentry, d_lru)) {
+ spin_unlock(&dentry->d_lock);
+ continue;
+ }
/*
* We found an inuse dentry which was not removed from
* the LRU because of laziness during lookup. Do not free
* it - just keep it off the LRU list.
*/
- spin_lock(&dentry->d_lock);
- if (atomic_read(&dentry->d_count)) {
+ if (dentry->d_count) {
+ dentry_lru_del(dentry);
spin_unlock(&dentry->d_lock);
continue;
}
- prune_one_dentry(dentry);
- /* dentry->d_lock was dropped in prune_one_dentry() */
- cond_resched_lock(&dcache_lock);
+
+ rcu_read_unlock();
+
+ try_prune_one_dentry(dentry);
+
+ rcu_read_lock();
}
+ rcu_read_unlock();
}
/**
LIST_HEAD(tmp);
int cnt = *count;
- spin_lock(&dcache_lock);
+relock:
+ spin_lock(&dcache_lru_lock);
while (!list_empty(&sb->s_dentry_lru)) {
dentry = list_entry(sb->s_dentry_lru.prev,
struct dentry, d_lru);
BUG_ON(dentry->d_sb != sb);
+ if (!spin_trylock(&dentry->d_lock)) {
+ spin_unlock(&dcache_lru_lock);
+ cpu_relax();
+ goto relock;
+ }
+
/*
* If we are honouring the DCACHE_REFERENCED flag and the
* dentry has this flag set, don't free it. Clear the flag
* and put it back on the LRU.
*/
- if (flags & DCACHE_REFERENCED) {
- spin_lock(&dentry->d_lock);
- if (dentry->d_flags & DCACHE_REFERENCED) {
- dentry->d_flags &= ~DCACHE_REFERENCED;
- list_move(&dentry->d_lru, &referenced);
- spin_unlock(&dentry->d_lock);
- cond_resched_lock(&dcache_lock);
- continue;
- }
+ if (flags & DCACHE_REFERENCED &&
+ dentry->d_flags & DCACHE_REFERENCED) {
+ dentry->d_flags &= ~DCACHE_REFERENCED;
+ list_move(&dentry->d_lru, &referenced);
spin_unlock(&dentry->d_lock);
+ } else {
+ list_move_tail(&dentry->d_lru, &tmp);
+ spin_unlock(&dentry->d_lock);
+ if (!--cnt)
+ break;
}
-
- list_move_tail(&dentry->d_lru, &tmp);
- if (!--cnt)
- break;
- cond_resched_lock(&dcache_lock);
+ cond_resched_lock(&dcache_lru_lock);
}
-
- *count = cnt;
- shrink_dentry_list(&tmp);
-
if (!list_empty(&referenced))
list_splice(&referenced, &sb->s_dentry_lru);
- spin_unlock(&dcache_lock);
+ spin_unlock(&dcache_lru_lock);
+ shrink_dentry_list(&tmp);
+
+ *count = cnt;
}
/**
{
struct super_block *sb, *p = NULL;
int w_count;
- int unused = percpu_counter_sum_positive(&nr_dentry_unused);
+ int unused = dentry_stat.nr_unused;
int prune_ratio;
int pruned;
if (unused == 0 || count == 0)
return;
- spin_lock(&dcache_lock);
if (count >= unused)
prune_ratio = 1;
else
if (down_read_trylock(&sb->s_umount)) {
if ((sb->s_root != NULL) &&
(!list_empty(&sb->s_dentry_lru))) {
- spin_unlock(&dcache_lock);
__shrink_dcache_sb(sb, &w_count,
DCACHE_REFERENCED);
pruned -= w_count;
- spin_lock(&dcache_lock);
}
up_read(&sb->s_umount);
}
if (p)
__put_super(p);
spin_unlock(&sb_lock);
- spin_unlock(&dcache_lock);
}
/**
{
LIST_HEAD(tmp);
- spin_lock(&dcache_lock);
+ spin_lock(&dcache_lru_lock);
while (!list_empty(&sb->s_dentry_lru)) {
list_splice_init(&sb->s_dentry_lru, &tmp);
+ spin_unlock(&dcache_lru_lock);
shrink_dentry_list(&tmp);
+ spin_lock(&dcache_lru_lock);
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&dcache_lru_lock);
}
EXPORT_SYMBOL(shrink_dcache_sb);
BUG_ON(!IS_ROOT(dentry));
/* detach this root from the system */
- spin_lock(&dcache_lock);
+ spin_lock(&dentry->d_lock);
dentry_lru_del(dentry);
__d_drop(dentry);
- spin_unlock(&dcache_lock);
+ spin_unlock(&dentry->d_lock);
for (;;) {
/* descend to the first leaf in the current subtree */
/* this is a branch with children - detach all of them
* from the system in one go */
- spin_lock(&dcache_lock);
+ spin_lock(&dentry->d_lock);
list_for_each_entry(loop, &dentry->d_subdirs,
d_u.d_child) {
+ spin_lock_nested(&loop->d_lock,
+ DENTRY_D_LOCK_NESTED);
dentry_lru_del(loop);
__d_drop(loop);
- cond_resched_lock(&dcache_lock);
+ spin_unlock(&loop->d_lock);
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&dentry->d_lock);
/* move to the first child */
dentry = list_entry(dentry->d_subdirs.next,
do {
struct inode *inode;
- if (atomic_read(&dentry->d_count) != 0) {
+ if (dentry->d_count != 0) {
printk(KERN_ERR
"BUG: Dentry %p{i=%lx,n=%s}"
" still in use (%d)"
dentry->d_inode ?
dentry->d_inode->i_ino : 0UL,
dentry->d_name.name,
- atomic_read(&dentry->d_count),
+ dentry->d_count,
dentry->d_sb->s_type->name,
dentry->d_sb->s_id);
BUG();
}
- if (IS_ROOT(dentry))
+ if (IS_ROOT(dentry)) {
parent = NULL;
- else {
+ list_del(&dentry->d_u.d_child);
+ } else {
parent = dentry->d_parent;
- atomic_dec(&parent->d_count);
+ spin_lock(&parent->d_lock);
+ parent->d_count--;
+ list_del(&dentry->d_u.d_child);
+ spin_unlock(&parent->d_lock);
}
- list_del(&dentry->d_u.d_child);
detached++;
inode = dentry->d_inode;
/*
* destroy the dentries attached to a superblock on unmounting
- * - we don't need to use dentry->d_lock, and only need dcache_lock when
- * removing the dentry from the system lists and hashes because:
+ * - we don't need to use dentry->d_lock because:
* - the superblock is detached from all mountings and open files, so the
* dentry trees will not be rearranged by the VFS
* - s_umount is write-locked, so the memory pressure shrinker will ignore
dentry = sb->s_root;
sb->s_root = NULL;
- atomic_dec(&dentry->d_count);
+ spin_lock(&dentry->d_lock);
+ dentry->d_count--;
+ spin_unlock(&dentry->d_lock);
shrink_dcache_for_umount_subtree(dentry);
- while (!hlist_empty(&sb->s_anon)) {
- dentry = hlist_entry(sb->s_anon.first, struct dentry, d_hash);
+ while (!hlist_bl_empty(&sb->s_anon)) {
+ dentry = hlist_bl_entry(hlist_bl_first(&sb->s_anon), struct dentry, d_hash);
shrink_dcache_for_umount_subtree(dentry);
}
}
* Return true if the parent or its subdirectories contain
* a mount point
*/
-
int have_submounts(struct dentry *parent)
{
- struct dentry *this_parent = parent;
+ struct dentry *this_parent;
struct list_head *next;
+ unsigned seq;
+ int locked = 0;
+
+ seq = read_seqbegin(&rename_lock);
+again:
+ this_parent = parent;
- spin_lock(&dcache_lock);
if (d_mountpoint(parent))
goto positive;
+ spin_lock(&this_parent->d_lock);
repeat:
next = this_parent->d_subdirs.next;
resume:
struct list_head *tmp = next;
struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
next = tmp->next;
+
+ spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
/* Have we found a mount point ? */
- if (d_mountpoint(dentry))
+ if (d_mountpoint(dentry)) {
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&this_parent->d_lock);
goto positive;
+ }
if (!list_empty(&dentry->d_subdirs)) {
+ spin_unlock(&this_parent->d_lock);
+ spin_release(&dentry->d_lock.dep_map, 1, _RET_IP_);
this_parent = dentry;
+ spin_acquire(&this_parent->d_lock.dep_map, 0, 1, _RET_IP_);
goto repeat;
}
+ spin_unlock(&dentry->d_lock);
}
/*
* All done at this level ... ascend and resume the search.
*/
if (this_parent != parent) {
- next = this_parent->d_u.d_child.next;
- this_parent = this_parent->d_parent;
+ struct dentry *tmp;
+ struct dentry *child;
+
+ tmp = this_parent->d_parent;
+ rcu_read_lock();
+ spin_unlock(&this_parent->d_lock);
+ child = this_parent;
+ this_parent = tmp;
+ spin_lock(&this_parent->d_lock);
+ /* might go back up the wrong parent if we have had a rename
+ * or deletion */
+ if (this_parent != child->d_parent ||
+ (!locked && read_seqretry(&rename_lock, seq))) {
+ spin_unlock(&this_parent->d_lock);
+ rcu_read_unlock();
+ goto rename_retry;
+ }
+ rcu_read_unlock();
+ next = child->d_u.d_child.next;
goto resume;
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&this_parent->d_lock);
+ if (!locked && read_seqretry(&rename_lock, seq))
+ goto rename_retry;
+ if (locked)
+ write_sequnlock(&rename_lock);
return 0; /* No mount points found in tree */
positive:
- spin_unlock(&dcache_lock);
+ if (!locked && read_seqretry(&rename_lock, seq))
+ goto rename_retry;
+ if (locked)
+ write_sequnlock(&rename_lock);
return 1;
+
+rename_retry:
+ locked = 1;
+ write_seqlock(&rename_lock);
+ goto again;
}
EXPORT_SYMBOL(have_submounts);
*/
static int select_parent(struct dentry * parent)
{
- struct dentry *this_parent = parent;
+ struct dentry *this_parent;
struct list_head *next;
+ unsigned seq;
int found = 0;
+ int locked = 0;
- spin_lock(&dcache_lock);
+ seq = read_seqbegin(&rename_lock);
+again:
+ this_parent = parent;
+ spin_lock(&this_parent->d_lock);
repeat:
next = this_parent->d_subdirs.next;
resume:
struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
next = tmp->next;
+ spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
+
/*
* move only zero ref count dentries to the end
* of the unused list for prune_dcache
*/
- if (!atomic_read(&dentry->d_count)) {
+ if (!dentry->d_count) {
dentry_lru_move_tail(dentry);
found++;
} else {
* ensures forward progress). We'll be coming back to find
* the rest.
*/
- if (found && need_resched())
+ if (found && need_resched()) {
+ spin_unlock(&dentry->d_lock);
goto out;
+ }
/*
* Descend a level if the d_subdirs list is non-empty.
*/
if (!list_empty(&dentry->d_subdirs)) {
+ spin_unlock(&this_parent->d_lock);
+ spin_release(&dentry->d_lock.dep_map, 1, _RET_IP_);
this_parent = dentry;
+ spin_acquire(&this_parent->d_lock.dep_map, 0, 1, _RET_IP_);
goto repeat;
}
+
+ spin_unlock(&dentry->d_lock);
}
/*
* All done at this level ... ascend and resume the search.
*/
if (this_parent != parent) {
- next = this_parent->d_u.d_child.next;
- this_parent = this_parent->d_parent;
+ struct dentry *tmp;
+ struct dentry *child;
+
+ tmp = this_parent->d_parent;
+ rcu_read_lock();
+ spin_unlock(&this_parent->d_lock);
+ child = this_parent;
+ this_parent = tmp;
+ spin_lock(&this_parent->d_lock);
+ /* might go back up the wrong parent if we have had a rename
+ * or deletion */
+ if (this_parent != child->d_parent ||
+ (!locked && read_seqretry(&rename_lock, seq))) {
+ spin_unlock(&this_parent->d_lock);
+ rcu_read_unlock();
+ goto rename_retry;
+ }
+ rcu_read_unlock();
+ next = child->d_u.d_child.next;
goto resume;
}
out:
- spin_unlock(&dcache_lock);
+ spin_unlock(&this_parent->d_lock);
+ if (!locked && read_seqretry(&rename_lock, seq))
+ goto rename_retry;
+ if (locked)
+ write_sequnlock(&rename_lock);
return found;
+
+rename_retry:
+ if (found)
+ return found;
+ locked = 1;
+ write_seqlock(&rename_lock);
+ goto again;
}
/**
*/
static int shrink_dcache_memory(struct shrinker *shrink, int nr, gfp_t gfp_mask)
{
- int nr_unused;
-
if (nr) {
if (!(gfp_mask & __GFP_FS))
return -1;
prune_dcache(nr);
}
- nr_unused = percpu_counter_sum_positive(&nr_dentry_unused);
- return (nr_unused / 100) * sysctl_vfs_cache_pressure;
+ return (dentry_stat.nr_unused / 100) * sysctl_vfs_cache_pressure;
}
static struct shrinker dcache_shrinker = {
memcpy(dname, name->name, name->len);
dname[name->len] = 0;
- atomic_set(&dentry->d_count, 1);
+ dentry->d_count = 1;
dentry->d_flags = DCACHE_UNHASHED;
spin_lock_init(&dentry->d_lock);
+ seqcount_init(&dentry->d_seq);
dentry->d_inode = NULL;
dentry->d_parent = NULL;
dentry->d_sb = NULL;
dentry->d_op = NULL;
dentry->d_fsdata = NULL;
- dentry->d_mounted = 0;
- INIT_HLIST_NODE(&dentry->d_hash);
+ INIT_HLIST_BL_NODE(&dentry->d_hash);
INIT_LIST_HEAD(&dentry->d_lru);
INIT_LIST_HEAD(&dentry->d_subdirs);
INIT_LIST_HEAD(&dentry->d_alias);
+ INIT_LIST_HEAD(&dentry->d_u.d_child);
if (parent) {
- dentry->d_parent = dget(parent);
+ spin_lock(&parent->d_lock);
+ /*
+ * don't need child lock because it is not subject
+ * to concurrency here
+ */
+ __dget_dlock(parent);
+ dentry->d_parent = parent;
dentry->d_sb = parent->d_sb;
- } else {
- INIT_LIST_HEAD(&dentry->d_u.d_child);
- }
-
- spin_lock(&dcache_lock);
- if (parent)
list_add(&dentry->d_u.d_child, &parent->d_subdirs);
- spin_unlock(&dcache_lock);
+ spin_unlock(&parent->d_lock);
+ }
- percpu_counter_inc(&nr_dentry);
+ this_cpu_inc(nr_dentry);
return dentry;
}
EXPORT_SYMBOL(d_alloc);
+struct dentry *d_alloc_pseudo(struct super_block *sb, const struct qstr *name)
+{
+ struct dentry *dentry = d_alloc(NULL, name);
+ if (dentry) {
+ dentry->d_sb = sb;
+ dentry->d_parent = dentry;
+ dentry->d_flags |= DCACHE_DISCONNECTED;
+ }
+ return dentry;
+}
+EXPORT_SYMBOL(d_alloc_pseudo);
+
struct dentry *d_alloc_name(struct dentry *parent, const char *name)
{
struct qstr q;
}
EXPORT_SYMBOL(d_alloc_name);
-/* the caller must hold dcache_lock */
+void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op)
+{
+ BUG_ON(dentry->d_op);
+ BUG_ON(dentry->d_flags & (DCACHE_OP_HASH |
+ DCACHE_OP_COMPARE |
+ DCACHE_OP_REVALIDATE |
+ DCACHE_OP_DELETE ));
+ dentry->d_op = op;
+ if (!op)
+ return;
+ if (op->d_hash)
+ dentry->d_flags |= DCACHE_OP_HASH;
+ if (op->d_compare)
+ dentry->d_flags |= DCACHE_OP_COMPARE;
+ if (op->d_revalidate)
+ dentry->d_flags |= DCACHE_OP_REVALIDATE;
+ if (op->d_delete)
+ dentry->d_flags |= DCACHE_OP_DELETE;
+
+}
+EXPORT_SYMBOL(d_set_d_op);
+
static void __d_instantiate(struct dentry *dentry, struct inode *inode)
{
+ spin_lock(&dentry->d_lock);
if (inode)
list_add(&dentry->d_alias, &inode->i_dentry);
dentry->d_inode = inode;
+ dentry_rcuwalk_barrier(dentry);
+ spin_unlock(&dentry->d_lock);
fsnotify_d_instantiate(dentry, inode);
}
void d_instantiate(struct dentry *entry, struct inode * inode)
{
BUG_ON(!list_empty(&entry->d_alias));
- spin_lock(&dcache_lock);
+ if (inode)
+ spin_lock(&inode->i_lock);
__d_instantiate(entry, inode);
- spin_unlock(&dcache_lock);
+ if (inode)
+ spin_unlock(&inode->i_lock);
security_d_instantiate(entry, inode);
}
EXPORT_SYMBOL(d_instantiate);
list_for_each_entry(alias, &inode->i_dentry, d_alias) {
struct qstr *qstr = &alias->d_name;
+ /*
+ * Don't need alias->d_lock here, because aliases with
+ * d_parent == entry->d_parent are not subject to name or
+ * parent changes, because the parent inode i_mutex is held.
+ */
if (qstr->hash != hash)
continue;
if (alias->d_parent != entry->d_parent)
continue;
- if (qstr->len != len)
+ if (dentry_cmp(qstr->name, qstr->len, name, len))
continue;
- if (memcmp(qstr->name, name, len))
- continue;
- dget_locked(alias);
+ __dget(alias);
return alias;
}
BUG_ON(!list_empty(&entry->d_alias));
- spin_lock(&dcache_lock);
+ if (inode)
+ spin_lock(&inode->i_lock);
result = __d_instantiate_unique(entry, inode);
- spin_unlock(&dcache_lock);
+ if (inode)
+ spin_unlock(&inode->i_lock);
if (!result) {
security_d_instantiate(entry, inode);
}
EXPORT_SYMBOL(d_alloc_root);
-static inline struct hlist_head *d_hash(struct dentry *parent,
- unsigned long hash)
-{
- hash += ((unsigned long) parent ^ GOLDEN_RATIO_PRIME) / L1_CACHE_BYTES;
- hash = hash ^ ((hash ^ GOLDEN_RATIO_PRIME) >> D_HASHBITS);
- return dentry_hashtable + (hash & D_HASHMASK);
-}
-
/**
* d_obtain_alias - find or allocate a dentry for a given inode
* @inode: inode to allocate the dentry for
}
tmp->d_parent = tmp; /* make sure dput doesn't croak */
- spin_lock(&dcache_lock);
+
+ spin_lock(&inode->i_lock);
res = __d_find_alias(inode, 0);
if (res) {
- spin_unlock(&dcache_lock);
+ spin_unlock(&inode->i_lock);
dput(tmp);
goto out_iput;
}
tmp->d_sb = inode->i_sb;
tmp->d_inode = inode;
tmp->d_flags |= DCACHE_DISCONNECTED;
- tmp->d_flags &= ~DCACHE_UNHASHED;
list_add(&tmp->d_alias, &inode->i_dentry);
- hlist_add_head(&tmp->d_hash, &inode->i_sb->s_anon);
+ bit_spin_lock(0, (unsigned long *)&tmp->d_sb->s_anon.first);
+ tmp->d_flags &= ~DCACHE_UNHASHED;
+ hlist_bl_add_head(&tmp->d_hash, &tmp->d_sb->s_anon);
+ __bit_spin_unlock(0, (unsigned long *)&tmp->d_sb->s_anon.first);
spin_unlock(&tmp->d_lock);
+ spin_unlock(&inode->i_lock);
- spin_unlock(&dcache_lock);
return tmp;
out_iput:
struct dentry *new = NULL;
if (inode && S_ISDIR(inode->i_mode)) {
- spin_lock(&dcache_lock);
+ spin_lock(&inode->i_lock);
new = __d_find_alias(inode, 1);
if (new) {
BUG_ON(!(new->d_flags & DCACHE_DISCONNECTED));
- spin_unlock(&dcache_lock);
+ spin_unlock(&inode->i_lock);
security_d_instantiate(new, inode);
d_move(new, dentry);
iput(inode);
} else {
- /* already taking dcache_lock, so d_add() by hand */
+ /* already taking inode->i_lock, so d_add() by hand */
__d_instantiate(dentry, inode);
- spin_unlock(&dcache_lock);
+ spin_unlock(&inode->i_lock);
security_d_instantiate(dentry, inode);
d_rehash(dentry);
}
* Negative dentry: instantiate it unless the inode is a directory and
* already has a dentry.
*/
- spin_lock(&dcache_lock);
+ spin_lock(&inode->i_lock);
if (!S_ISDIR(inode->i_mode) || list_empty(&inode->i_dentry)) {
__d_instantiate(found, inode);
- spin_unlock(&dcache_lock);
+ spin_unlock(&inode->i_lock);
security_d_instantiate(found, inode);
return found;
}
* reference to it, move it in place and use it.
*/
new = list_entry(inode->i_dentry.next, struct dentry, d_alias);
- dget_locked(new);
- spin_unlock(&dcache_lock);
+ __dget(new);
+ spin_unlock(&inode->i_lock);
security_d_instantiate(found, inode);
d_move(new, found);
iput(inode);
EXPORT_SYMBOL(d_add_ci);
/**
+ * __d_lookup_rcu - search for a dentry (racy, store-free)
+ * @parent: parent dentry
+ * @name: qstr of name we wish to find
+ * @seq: returns d_seq value at the point where the dentry was found
+ * @inode: returns dentry->d_inode when the inode was found valid.
+ * Returns: dentry, or NULL
+ *
+ * __d_lookup_rcu is the dcache lookup function for rcu-walk name
+ * resolution (store-free path walking) design described in
+ * Documentation/filesystems/path-lookup.txt.
+ *
+ * This is not to be used outside core vfs.
+ *
+ * __d_lookup_rcu must only be used in rcu-walk mode, ie. with vfsmount lock
+ * held, and rcu_read_lock held. The returned dentry must not be stored into
+ * without taking d_lock and checking d_seq sequence count against @seq
+ * returned here.
+ *
+ * A refcount may be taken on the found dentry with the __d_rcu_to_refcount
+ * function.
+ *
+ * Alternatively, __d_lookup_rcu may be called again to look up the child of
+ * the returned dentry, so long as its parent's seqlock is checked after the
+ * child is looked up. Thus, an interlocking stepping of sequence lock checks
+ * is formed, giving integrity down the path walk.
+ */
+struct dentry *__d_lookup_rcu(struct dentry *parent, struct qstr *name,
+ unsigned *seq, struct inode **inode)
+{
+ unsigned int len = name->len;
+ unsigned int hash = name->hash;
+ const unsigned char *str = name->name;
+ struct dcache_hash_bucket *b = d_hash(parent, hash);
+ struct hlist_bl_node *node;
+ struct dentry *dentry;
+
+ /*
+ * Note: There is significant duplication with __d_lookup_rcu which is
+ * required to prevent single threaded performance regressions
+ * especially on architectures where smp_rmb (in seqcounts) are costly.
+ * Keep the two functions in sync.
+ */
+
+ /*
+ * The hash list is protected using RCU.
+ *
+ * Carefully use d_seq when comparing a candidate dentry, to avoid
+ * races with d_move().
+ *
+ * It is possible that concurrent renames can mess up our list
+ * walk here and result in missing our dentry, resulting in the
+ * false-negative result. d_lookup() protects against concurrent
+ * renames using rename_lock seqlock.
+ *
+ * See Documentation/vfs/dcache-locking.txt for more details.
+ */
+ hlist_bl_for_each_entry_rcu(dentry, node, &b->head, d_hash) {
+ struct inode *i;
+ const char *tname;
+ int tlen;
+
+ if (dentry->d_name.hash != hash)
+ continue;
+
+seqretry:
+ *seq = read_seqcount_begin(&dentry->d_seq);
+ if (dentry->d_parent != parent)
+ continue;
+ if (d_unhashed(dentry))
+ continue;
+ tlen = dentry->d_name.len;
+ tname = dentry->d_name.name;
+ i = dentry->d_inode;
+ prefetch(tname);
+ if (i)
+ prefetch(i);
+ /*
+ * This seqcount check is required to ensure name and
+ * len are loaded atomically, so as not to walk off the
+ * edge of memory when walking. If we could load this
+ * atomically some other way, we could drop this check.
+ */
+ if (read_seqcount_retry(&dentry->d_seq, *seq))
+ goto seqretry;
+ if (parent->d_flags & DCACHE_OP_COMPARE) {
+ if (parent->d_op->d_compare(parent, *inode,
+ dentry, i,
+ tlen, tname, name))
+ continue;
+ } else {
+ if (dentry_cmp(tname, tlen, str, len))
+ continue;
+ }
+ /*
+ * No extra seqcount check is required after the name
+ * compare. The caller must perform a seqcount check in
+ * order to do anything useful with the returned dentry
+ * anyway.
+ */
+ *inode = i;
+ return dentry;
+ }
+ return NULL;
+}
+
+/**
* d_lookup - search for a dentry
* @parent: parent dentry
* @name: qstr of name we wish to find
* dentry is returned. The caller must use dput to free the entry when it has
* finished using it. %NULL is returned if the dentry does not exist.
*/
-struct dentry * d_lookup(struct dentry * parent, struct qstr * name)
+struct dentry *d_lookup(struct dentry *parent, struct qstr *name)
{
- struct dentry * dentry = NULL;
- unsigned long seq;
+ struct dentry *dentry;
+ unsigned seq;
do {
seq = read_seqbegin(&rename_lock);
}
EXPORT_SYMBOL(d_lookup);
-/*
+/**
* __d_lookup - search for a dentry (racy)
* @parent: parent dentry
* @name: qstr of name we wish to find
*
* __d_lookup callers must be commented.
*/
-struct dentry * __d_lookup(struct dentry * parent, struct qstr * name)
+struct dentry *__d_lookup(struct dentry *parent, struct qstr *name)
{
unsigned int len = name->len;
unsigned int hash = name->hash;
const unsigned char *str = name->name;
- struct hlist_head *head = d_hash(parent,hash);
+ struct dcache_hash_bucket *b = d_hash(parent, hash);
+ struct hlist_bl_node *node;
struct dentry *found = NULL;
- struct hlist_node *node;
struct dentry *dentry;
/*
+ * Note: There is significant duplication with __d_lookup_rcu which is
+ * required to prevent single threaded performance regressions
+ * especially on architectures where smp_rmb (in seqcounts) are costly.
+ * Keep the two functions in sync.
+ */
+
+ /*
* The hash list is protected using RCU.
*
* Take d_lock when comparing a candidate dentry, to avoid races
*/
rcu_read_lock();
- hlist_for_each_entry_rcu(dentry, node, head, d_hash) {
- struct qstr *qstr;
+ hlist_bl_for_each_entry_rcu(dentry, node, &b->head, d_hash) {
+ const char *tname;
+ int tlen;
if (dentry->d_name.hash != hash)
continue;
- if (dentry->d_parent != parent)
- continue;
spin_lock(&dentry->d_lock);
-
- /*
- * Recheck the dentry after taking the lock - d_move may have
- * changed things. Don't bother checking the hash because
- * we're about to compare the whole name anyway.
- */
if (dentry->d_parent != parent)
goto next;
-
- /* non-existing due to RCU? */
if (d_unhashed(dentry))
goto next;
* It is safe to compare names since d_move() cannot
* change the qstr (protected by d_lock).
*/
- qstr = &dentry->d_name;
- if (parent->d_op && parent->d_op->d_compare) {
- if (parent->d_op->d_compare(parent, qstr, name))
+ tlen = dentry->d_name.len;
+ tname = dentry->d_name.name;
+ if (parent->d_flags & DCACHE_OP_COMPARE) {
+ if (parent->d_op->d_compare(parent, parent->d_inode,
+ dentry, dentry->d_inode,
+ tlen, tname, name))
goto next;
} else {
- if (qstr->len != len)
- goto next;
- if (memcmp(qstr->name, str, len))
+ if (dentry_cmp(tname, tlen, str, len))
goto next;
}
- atomic_inc(&dentry->d_count);
+ dentry->d_count++;
found = dentry;
spin_unlock(&dentry->d_lock);
break;
* routine may choose to leave the hash value unchanged.
*/
name->hash = full_name_hash(name->name, name->len);
- if (dir->d_op && dir->d_op->d_hash) {
- if (dir->d_op->d_hash(dir, name) < 0)
+ if (dir->d_flags & DCACHE_OP_HASH) {
+ if (dir->d_op->d_hash(dir, dir->d_inode, name) < 0)
goto out;
}
dentry = d_lookup(dir, name);
}
/**
- * d_validate - verify dentry provided from insecure source
+ * d_validate - verify dentry provided from insecure source (deprecated)
* @dentry: The dentry alleged to be valid child of @dparent
* @dparent: The parent dentry (known to be valid)
*
* An insecure source has sent us a dentry, here we verify it and dget() it.
* This is used by ncpfs in its readdir implementation.
* Zero is returned in the dentry is invalid.
+ *
+ * This function is slow for big directories, and deprecated, do not use it.
*/
-int d_validate(struct dentry *dentry, struct dentry *parent)
+int d_validate(struct dentry *dentry, struct dentry *dparent)
{
- struct hlist_head *head = d_hash(parent, dentry->d_name.hash);
- struct hlist_node *node;
- struct dentry *d;
-
- /* Check whether the ptr might be valid at all.. */
- if (!kmem_ptr_validate(dentry_cache, dentry))
- return 0;
- if (dentry->d_parent != parent)
- return 0;
+ struct dentry *child;
- rcu_read_lock();
- hlist_for_each_entry_rcu(d, node, head, d_hash) {
- if (d == dentry) {
- dget(dentry);
+ spin_lock(&dparent->d_lock);
+ list_for_each_entry(child, &dparent->d_subdirs, d_u.d_child) {
+ if (dentry == child) {
+ spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
+ __dget_dlock(dentry);
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&dparent->d_lock);
return 1;
}
}
- rcu_read_unlock();
+ spin_unlock(&dparent->d_lock);
+
return 0;
}
EXPORT_SYMBOL(d_validate);
void d_delete(struct dentry * dentry)
{
+ struct inode *inode;
int isdir = 0;
/*
* Are we the only user?
*/
- spin_lock(&dcache_lock);
+again:
spin_lock(&dentry->d_lock);
- isdir = S_ISDIR(dentry->d_inode->i_mode);
- if (atomic_read(&dentry->d_count) == 1) {
+ inode = dentry->d_inode;
+ isdir = S_ISDIR(inode->i_mode);
+ if (dentry->d_count == 1) {
+ if (inode && !spin_trylock(&inode->i_lock)) {
+ spin_unlock(&dentry->d_lock);
+ cpu_relax();
+ goto again;
+ }
dentry->d_flags &= ~DCACHE_CANT_MOUNT;
- dentry_iput(dentry);
+ dentry_unlink_inode(dentry);
fsnotify_nameremove(dentry, isdir);
return;
}
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
fsnotify_nameremove(dentry, isdir);
}
EXPORT_SYMBOL(d_delete);
-static void __d_rehash(struct dentry * entry, struct hlist_head *list)
+static void __d_rehash(struct dentry * entry, struct dcache_hash_bucket *b)
{
-
+ BUG_ON(!d_unhashed(entry));
+ spin_lock_bucket(b);
entry->d_flags &= ~DCACHE_UNHASHED;
- hlist_add_head_rcu(&entry->d_hash, list);
+ hlist_bl_add_head_rcu(&entry->d_hash, &b->head);
+ spin_unlock_bucket(b);
}
static void _d_rehash(struct dentry * entry)
void d_rehash(struct dentry * entry)
{
- spin_lock(&dcache_lock);
spin_lock(&entry->d_lock);
_d_rehash(entry);
spin_unlock(&entry->d_lock);
- spin_unlock(&dcache_lock);
}
EXPORT_SYMBOL(d_rehash);
-/*
- * When switching names, the actual string doesn't strictly have to
- * be preserved in the target - because we're dropping the target
- * anyway. As such, we can just do a simple memcpy() to copy over
- * the new name before we switch.
+/**
+ * dentry_update_name_case - update case insensitive dentry with a new name
+ * @dentry: dentry to be updated
+ * @name: new name
*
- * Note that we have to be a lot more careful about getting the hash
- * switched - we have to switch the hash value properly even if it
- * then no longer matches the actual (corrupted) string of the target.
- * The hash value has to match the hash queue that the dentry is on..
+ * Update a case insensitive dentry with new case of name.
+ *
+ * dentry must have been returned by d_lookup with name @name. Old and new
+ * name lengths must match (ie. no d_compare which allows mismatched name
+ * lengths).
+ *
+ * Parent inode i_mutex must be held over d_lookup and into this call (to
+ * keep renames and concurrent inserts, and readdir(2) away).
*/
+void dentry_update_name_case(struct dentry *dentry, struct qstr *name)
+{
+ BUG_ON(!mutex_is_locked(&dentry->d_inode->i_mutex));
+ BUG_ON(dentry->d_name.len != name->len); /* d_lookup gives this */
+
+ spin_lock(&dentry->d_lock);
+ write_seqcount_begin(&dentry->d_seq);
+ memcpy((unsigned char *)dentry->d_name.name, name->name, name->len);
+ write_seqcount_end(&dentry->d_seq);
+ spin_unlock(&dentry->d_lock);
+}
+EXPORT_SYMBOL(dentry_update_name_case);
+
static void switch_names(struct dentry *dentry, struct dentry *target)
{
if (dname_external(target)) {
swap(dentry->d_name.len, target->d_name.len);
}
+static void dentry_lock_for_move(struct dentry *dentry, struct dentry *target)
+{
+ /*
+ * XXXX: do we really need to take target->d_lock?
+ */
+ if (IS_ROOT(dentry) || dentry->d_parent == target->d_parent)
+ spin_lock(&target->d_parent->d_lock);
+ else {
+ if (d_ancestor(dentry->d_parent, target->d_parent)) {
+ spin_lock(&dentry->d_parent->d_lock);
+ spin_lock_nested(&target->d_parent->d_lock,
+ DENTRY_D_LOCK_NESTED);
+ } else {
+ spin_lock(&target->d_parent->d_lock);
+ spin_lock_nested(&dentry->d_parent->d_lock,
+ DENTRY_D_LOCK_NESTED);
+ }
+ }
+ if (target < dentry) {
+ spin_lock_nested(&target->d_lock, 2);
+ spin_lock_nested(&dentry->d_lock, 3);
+ } else {
+ spin_lock_nested(&dentry->d_lock, 2);
+ spin_lock_nested(&target->d_lock, 3);
+ }
+}
+
+static void dentry_unlock_parents_for_move(struct dentry *dentry,
+ struct dentry *target)
+{
+ if (target->d_parent != dentry->d_parent)
+ spin_unlock(&dentry->d_parent->d_lock);
+ if (target->d_parent != target)
+ spin_unlock(&target->d_parent->d_lock);
+}
+
/*
- * We cannibalize "target" when moving dentry on top of it,
- * because it's going to be thrown away anyway. We could be more
- * polite about it, though.
- *
- * This forceful removal will result in ugly /proc output if
- * somebody holds a file open that got deleted due to a rename.
- * We could be nicer about the deleted file, and let it show
- * up under the name it had before it was deleted rather than
- * under the original name of the file that was moved on top of it.
+ * When switching names, the actual string doesn't strictly have to
+ * be preserved in the target - because we're dropping the target
+ * anyway. As such, we can just do a simple memcpy() to copy over
+ * the new name before we switch.
+ *
+ * Note that we have to be a lot more careful about getting the hash
+ * switched - we have to switch the hash value properly even if it
+ * then no longer matches the actual (corrupted) string of the target.
+ * The hash value has to match the hash queue that the dentry is on..
*/
-
/*
- * d_move_locked - move a dentry
+ * d_move - move a dentry
* @dentry: entry to move
* @target: new dentry
*
* Update the dcache to reflect the move of a file name. Negative
* dcache entries should not be moved in this way.
*/
-static void d_move_locked(struct dentry * dentry, struct dentry * target)
+void d_move(struct dentry * dentry, struct dentry * target)
{
- struct hlist_head *list;
-
if (!dentry->d_inode)
printk(KERN_WARNING "VFS: moving negative dcache entry\n");
+ BUG_ON(d_ancestor(dentry, target));
+ BUG_ON(d_ancestor(target, dentry));
+
write_seqlock(&rename_lock);
- /*
- * XXXX: do we really need to take target->d_lock?
- */
- if (target < dentry) {
- spin_lock(&target->d_lock);
- spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
- } else {
- spin_lock(&dentry->d_lock);
- spin_lock_nested(&target->d_lock, DENTRY_D_LOCK_NESTED);
- }
- /* Move the dentry to the target hash queue, if on different bucket */
- if (d_unhashed(dentry))
- goto already_unhashed;
+ dentry_lock_for_move(dentry, target);
- hlist_del_rcu(&dentry->d_hash);
+ write_seqcount_begin(&dentry->d_seq);
+ write_seqcount_begin(&target->d_seq);
-already_unhashed:
- list = d_hash(target->d_parent, target->d_name.hash);
- __d_rehash(dentry, list);
+ /* __d_drop does write_seqcount_barrier, but they're OK to nest. */
+
+ /*
+ * Move the dentry to the target hash queue. Don't bother checking
+ * for the same hash queue because of how unlikely it is.
+ */
+ __d_drop(dentry);
+ __d_rehash(dentry, d_hash(target->d_parent, target->d_name.hash));
/* Unhash the target: dput() will then get rid of it */
__d_drop(target);
}
list_add(&dentry->d_u.d_child, &dentry->d_parent->d_subdirs);
+
+ write_seqcount_end(&target->d_seq);
+ write_seqcount_end(&dentry->d_seq);
+
+ dentry_unlock_parents_for_move(dentry, target);
spin_unlock(&target->d_lock);
fsnotify_d_move(dentry);
spin_unlock(&dentry->d_lock);
write_sequnlock(&rename_lock);
}
-
-/**
- * d_move - move a dentry
- * @dentry: entry to move
- * @target: new dentry
- *
- * Update the dcache to reflect the move of a file name. Negative
- * dcache entries should not be moved in this way.
- */
-
-void d_move(struct dentry * dentry, struct dentry * target)
-{
- spin_lock(&dcache_lock);
- d_move_locked(dentry, target);
- spin_unlock(&dcache_lock);
-}
EXPORT_SYMBOL(d_move);
/**
* This helper attempts to cope with remotely renamed directories
*
* It assumes that the caller is already holding
- * dentry->d_parent->d_inode->i_mutex and the dcache_lock
+ * dentry->d_parent->d_inode->i_mutex and the inode->i_lock
*
* Note: If ever the locking in lock_rename() changes, then please
* remember to update this too...
*/
-static struct dentry *__d_unalias(struct dentry *dentry, struct dentry *alias)
- __releases(dcache_lock)
+static struct dentry *__d_unalias(struct inode *inode,
+ struct dentry *dentry, struct dentry *alias)
{
struct mutex *m1 = NULL, *m2 = NULL;
struct dentry *ret;
goto out_err;
m2 = &alias->d_parent->d_inode->i_mutex;
out_unalias:
- d_move_locked(alias, dentry);
+ d_move(alias, dentry);
ret = alias;
out_err:
- spin_unlock(&dcache_lock);
+ spin_unlock(&inode->i_lock);
if (m2)
mutex_unlock(m2);
if (m1)
/*
* Prepare an anonymous dentry for life in the superblock's dentry tree as a
* named dentry in place of the dentry to be replaced.
+ * returns with anon->d_lock held!
*/
static void __d_materialise_dentry(struct dentry *dentry, struct dentry *anon)
{
struct dentry *dparent, *aparent;
- switch_names(dentry, anon);
- swap(dentry->d_name.hash, anon->d_name.hash);
+ dentry_lock_for_move(anon, dentry);
+
+ write_seqcount_begin(&dentry->d_seq);
+ write_seqcount_begin(&anon->d_seq);
dparent = dentry->d_parent;
aparent = anon->d_parent;
+ switch_names(dentry, anon);
+ swap(dentry->d_name.hash, anon->d_name.hash);
+
dentry->d_parent = (aparent == anon) ? dentry : aparent;
list_del(&dentry->d_u.d_child);
if (!IS_ROOT(dentry))
else
INIT_LIST_HEAD(&anon->d_u.d_child);
+ write_seqcount_end(&dentry->d_seq);
+ write_seqcount_end(&anon->d_seq);
+
+ dentry_unlock_parents_for_move(anon, dentry);
+ spin_unlock(&dentry->d_lock);
+
+ /* anon->d_lock still locked, returns locked */
anon->d_flags &= ~DCACHE_DISCONNECTED;
}
BUG_ON(!d_unhashed(dentry));
- spin_lock(&dcache_lock);
-
if (!inode) {
actual = dentry;
__d_instantiate(dentry, NULL);
- goto found_lock;
+ d_rehash(actual);
+ goto out_nolock;
}
+ spin_lock(&inode->i_lock);
+
if (S_ISDIR(inode->i_mode)) {
struct dentry *alias;
/* Is this an anonymous mountpoint that we could splice
* into our tree? */
if (IS_ROOT(alias)) {
- spin_lock(&alias->d_lock);
__d_materialise_dentry(dentry, alias);
__d_drop(alias);
goto found;
}
/* Nope, but we must(!) avoid directory aliasing */
- actual = __d_unalias(dentry, alias);
+ actual = __d_unalias(inode, dentry, alias);
if (IS_ERR(actual))
dput(alias);
goto out_nolock;
actual = __d_instantiate_unique(dentry, inode);
if (!actual)
actual = dentry;
- else if (unlikely(!d_unhashed(actual)))
- goto shouldnt_be_hashed;
+ else
+ BUG_ON(!d_unhashed(actual));
-found_lock:
spin_lock(&actual->d_lock);
found:
_d_rehash(actual);
spin_unlock(&actual->d_lock);
- spin_unlock(&dcache_lock);
+ spin_unlock(&inode->i_lock);
out_nolock:
if (actual == dentry) {
security_d_instantiate(dentry, inode);
iput(inode);
return actual;
-
-shouldnt_be_hashed:
- spin_unlock(&dcache_lock);
- BUG();
}
EXPORT_SYMBOL_GPL(d_materialise_unique);
* @buffer: pointer to the end of the buffer
* @buflen: pointer to buffer length
*
- * Caller holds the dcache_lock.
+ * Caller holds the rename_lock.
*
* If path is not reachable from the supplied root, then the value of
* root is changed (without modifying refcounts).
}
parent = dentry->d_parent;
prefetch(parent);
+ spin_lock(&dentry->d_lock);
error = prepend_name(buffer, buflen, &dentry->d_name);
+ spin_unlock(&dentry->d_lock);
if (!error)
error = prepend(buffer, buflen, "/", 1);
if (error)
int error;
prepend(&res, &buflen, "\0", 1);
- spin_lock(&dcache_lock);
+ write_seqlock(&rename_lock);
error = prepend_path(path, root, &res, &buflen);
- spin_unlock(&dcache_lock);
+ write_sequnlock(&rename_lock);
if (error)
return ERR_PTR(error);
return path->dentry->d_op->d_dname(path->dentry, buf, buflen);
get_fs_root(current->fs, &root);
- spin_lock(&dcache_lock);
+ write_seqlock(&rename_lock);
tmp = root;
error = path_with_deleted(path, &tmp, &res, &buflen);
if (error)
res = ERR_PTR(error);
- spin_unlock(&dcache_lock);
+ write_sequnlock(&rename_lock);
path_put(&root);
return res;
}
return path->dentry->d_op->d_dname(path->dentry, buf, buflen);
get_fs_root(current->fs, &root);
- spin_lock(&dcache_lock);
+ write_seqlock(&rename_lock);
tmp = root;
error = path_with_deleted(path, &tmp, &res, &buflen);
if (!error && !path_equal(&tmp, &root))
error = prepend_unreachable(&res, &buflen);
- spin_unlock(&dcache_lock);
+ write_sequnlock(&rename_lock);
path_put(&root);
if (error)
res = ERR_PTR(error);
/*
* Write full pathname from the root of the filesystem into the buffer.
*/
-char *__dentry_path(struct dentry *dentry, char *buf, int buflen)
+static char *__dentry_path(struct dentry *dentry, char *buf, int buflen)
{
char *end = buf + buflen;
char *retval;
while (!IS_ROOT(dentry)) {
struct dentry *parent = dentry->d_parent;
+ int error;
prefetch(parent);
- if ((prepend_name(&end, &buflen, &dentry->d_name) != 0) ||
- (prepend(&end, &buflen, "/", 1) != 0))
+ spin_lock(&dentry->d_lock);
+ error = prepend_name(&end, &buflen, &dentry->d_name);
+ spin_unlock(&dentry->d_lock);
+ if (error != 0 || prepend(&end, &buflen, "/", 1) != 0)
goto Elong;
retval = end;
Elong:
return ERR_PTR(-ENAMETOOLONG);
}
-EXPORT_SYMBOL(__dentry_path);
+
+char *dentry_path_raw(struct dentry *dentry, char *buf, int buflen)
+{
+ char *retval;
+
+ write_seqlock(&rename_lock);
+ retval = __dentry_path(dentry, buf, buflen);
+ write_sequnlock(&rename_lock);
+
+ return retval;
+}
+EXPORT_SYMBOL(dentry_path_raw);
char *dentry_path(struct dentry *dentry, char *buf, int buflen)
{
char *p = NULL;
char *retval;
- spin_lock(&dcache_lock);
+ write_seqlock(&rename_lock);
if (d_unlinked(dentry)) {
p = buf + buflen;
if (prepend(&p, &buflen, "//deleted", 10) != 0)
buflen++;
}
retval = __dentry_path(dentry, buf, buflen);
- spin_unlock(&dcache_lock);
+ write_sequnlock(&rename_lock);
if (!IS_ERR(retval) && p)
*p = '/'; /* restore '/' overriden with '\0' */
return retval;
Elong:
- spin_unlock(&dcache_lock);
return ERR_PTR(-ENAMETOOLONG);
}
get_fs_root_and_pwd(current->fs, &root, &pwd);
error = -ENOENT;
- spin_lock(&dcache_lock);
+ write_seqlock(&rename_lock);
if (!d_unlinked(pwd.dentry)) {
unsigned long len;
struct path tmp = root;
prepend(&cwd, &buflen, "\0", 1);
error = prepend_path(&pwd, &tmp, &cwd, &buflen);
- spin_unlock(&dcache_lock);
+ write_sequnlock(&rename_lock);
if (error)
goto out;
if (copy_to_user(buf, cwd, len))
error = -EFAULT;
}
- } else
- spin_unlock(&dcache_lock);
+ } else {
+ write_sequnlock(&rename_lock);
+ }
out:
path_put(&pwd);
int is_subdir(struct dentry *new_dentry, struct dentry *old_dentry)
{
int result;
- unsigned long seq;
+ unsigned seq;
if (new_dentry == old_dentry)
return 1;
- /*
- * Need rcu_readlock to protect against the d_parent trashing
- * due to d_move
- */
- rcu_read_lock();
do {
/* for restarting inner loop in case of seq retry */
seq = read_seqbegin(&rename_lock);
+ /*
+ * Need rcu_readlock to protect against the d_parent trashing
+ * due to d_move
+ */
+ rcu_read_lock();
if (d_ancestor(old_dentry, new_dentry))
result = 1;
else
result = 0;
+ rcu_read_unlock();
} while (read_seqretry(&rename_lock, seq));
- rcu_read_unlock();
return result;
}
void d_genocide(struct dentry *root)
{
- struct dentry *this_parent = root;
+ struct dentry *this_parent;
struct list_head *next;
+ unsigned seq;
+ int locked = 0;
- spin_lock(&dcache_lock);
+ seq = read_seqbegin(&rename_lock);
+again:
+ this_parent = root;
+ spin_lock(&this_parent->d_lock);
repeat:
next = this_parent->d_subdirs.next;
resume:
struct list_head *tmp = next;
struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
next = tmp->next;
- if (d_unhashed(dentry)||!dentry->d_inode)
+
+ spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
+ if (d_unhashed(dentry) || !dentry->d_inode) {
+ spin_unlock(&dentry->d_lock);
continue;
+ }
if (!list_empty(&dentry->d_subdirs)) {
+ spin_unlock(&this_parent->d_lock);
+ spin_release(&dentry->d_lock.dep_map, 1, _RET_IP_);
this_parent = dentry;
+ spin_acquire(&this_parent->d_lock.dep_map, 0, 1, _RET_IP_);
goto repeat;
}
- atomic_dec(&dentry->d_count);
+ if (!(dentry->d_flags & DCACHE_GENOCIDE)) {
+ dentry->d_flags |= DCACHE_GENOCIDE;
+ dentry->d_count--;
+ }
+ spin_unlock(&dentry->d_lock);
}
if (this_parent != root) {
- next = this_parent->d_u.d_child.next;
- atomic_dec(&this_parent->d_count);
- this_parent = this_parent->d_parent;
+ struct dentry *tmp;
+ struct dentry *child;
+
+ tmp = this_parent->d_parent;
+ if (!(this_parent->d_flags & DCACHE_GENOCIDE)) {
+ this_parent->d_flags |= DCACHE_GENOCIDE;
+ this_parent->d_count--;
+ }
+ rcu_read_lock();
+ spin_unlock(&this_parent->d_lock);
+ child = this_parent;
+ this_parent = tmp;
+ spin_lock(&this_parent->d_lock);
+ /* might go back up the wrong parent if we have had a rename
+ * or deletion */
+ if (this_parent != child->d_parent ||
+ (!locked && read_seqretry(&rename_lock, seq))) {
+ spin_unlock(&this_parent->d_lock);
+ rcu_read_unlock();
+ goto rename_retry;
+ }
+ rcu_read_unlock();
+ next = child->d_u.d_child.next;
goto resume;
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&this_parent->d_lock);
+ if (!locked && read_seqretry(&rename_lock, seq))
+ goto rename_retry;
+ if (locked)
+ write_sequnlock(&rename_lock);
+ return;
+
+rename_retry:
+ locked = 1;
+ write_seqlock(&rename_lock);
+ goto again;
}
/**
dentry_hashtable =
alloc_large_system_hash("Dentry cache",
- sizeof(struct hlist_head),
+ sizeof(struct dcache_hash_bucket),
dhash_entries,
13,
HASH_EARLY,
0);
for (loop = 0; loop < (1 << d_hash_shift); loop++)
- INIT_HLIST_HEAD(&dentry_hashtable[loop]);
+ INIT_HLIST_BL_HEAD(&dentry_hashtable[loop].head);
}
static void __init dcache_init(void)
{
int loop;
- percpu_counter_init(&nr_dentry, 0);
- percpu_counter_init(&nr_dentry_unused, 0);
-
/*
* A constructor could be added for stable state like the lists,
* but it is probably not worth it because of the cache nature
dentry_hashtable =
alloc_large_system_hash("Dentry cache",
- sizeof(struct hlist_head),
+ sizeof(struct dcache_hash_bucket),
dhash_entries,
13,
0,
0);
for (loop = 0; loop < (1 << d_hash_shift); loop++)
- INIT_HLIST_HEAD(&dentry_hashtable[loop]);
+ INIT_HLIST_BL_HEAD(&dentry_hashtable[loop].head);
}
/* SLAB cache for __getname() consumers */
*/
static int ecryptfs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
{
- struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
- struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
+ struct dentry *lower_dentry;
+ struct vfsmount *lower_mnt;
struct dentry *dentry_save;
struct vfsmount *vfsmount_save;
int rc = 1;
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ lower_dentry = ecryptfs_dentry_to_lower(dentry);
+ lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
if (!lower_dentry->d_op || !lower_dentry->d_op->d_revalidate)
goto out;
dentry_save = nd->path.dentry;
ecryptfs_dentry->d_parent));
lower_inode = lower_dentry->d_inode;
fsstack_copy_attr_atime(ecryptfs_dir_inode, lower_dir_dentry->d_inode);
- BUG_ON(!atomic_read(&lower_dentry->d_count));
+ BUG_ON(!lower_dentry->d_count);
ecryptfs_set_dentry_private(ecryptfs_dentry,
kmem_cache_alloc(ecryptfs_dentry_info_cache,
GFP_KERNEL));
struct qstr lower_name;
int rc = 0;
- ecryptfs_dentry->d_op = &ecryptfs_dops;
+ d_set_d_op(ecryptfs_dentry, &ecryptfs_dops);
if ((ecryptfs_dentry->d_name.len == 1
&& !strcmp(ecryptfs_dentry->d_name.name, "."))
|| (ecryptfs_dentry->d_name.len == 2
lower_name.hash = ecryptfs_dentry->d_name.hash;
if (lower_dir_dentry->d_op && lower_dir_dentry->d_op->d_hash) {
rc = lower_dir_dentry->d_op->d_hash(lower_dir_dentry,
- &lower_name);
+ lower_dir_dentry->d_inode, &lower_name);
if (rc < 0)
goto out_d_drop;
}
lower_name.hash = full_name_hash(lower_name.name, lower_name.len);
if (lower_dir_dentry->d_op && lower_dir_dentry->d_op->d_hash) {
rc = lower_dir_dentry->d_op->d_hash(lower_dir_dentry,
- &lower_name);
+ lower_dir_dentry->d_inode, &lower_name);
if (rc < 0)
goto out_d_drop;
}
}
static int
-ecryptfs_permission(struct inode *inode, int mask)
+ecryptfs_permission(struct inode *inode, int mask, unsigned int flags)
{
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
return inode_permission(ecryptfs_inode_to_lower(inode), mask);
}
if (special_file(lower_inode->i_mode))
init_special_inode(inode, lower_inode->i_mode,
lower_inode->i_rdev);
- dentry->d_op = &ecryptfs_dops;
+ d_set_d_op(dentry, &ecryptfs_dops);
fsstack_copy_attr_all(inode, lower_inode);
/* This size will be overwritten for real files w/ headers and
* other metadata */
deactivate_locked_super(s);
goto out;
}
- s->s_root->d_op = &ecryptfs_dops;
+ d_set_d_op(s->s_root, &ecryptfs_dops);
s->s_root->d_sb = s;
s->s_root->d_parent = s->s_root;
return inode;
}
+static void ecryptfs_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ struct ecryptfs_inode_info *inode_info;
+ inode_info = ecryptfs_inode_to_private(inode);
+
+ INIT_LIST_HEAD(&inode->i_dentry);
+ kmem_cache_free(ecryptfs_inode_info_cache, inode_info);
+}
+
/**
* ecryptfs_destroy_inode
* @inode: The ecryptfs inode
}
}
ecryptfs_destroy_crypt_stat(&inode_info->crypt_stat);
- kmem_cache_free(ecryptfs_inode_info_cache, inode_info);
+ call_rcu(&inode->i_rcu, ecryptfs_i_callback);
}
/**
return &ei->vfs_inode;
}
-static void efs_destroy_inode(struct inode *inode)
+static void efs_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(efs_inode_cachep, INODE_INFO(inode));
}
+static void efs_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, efs_i_callback);
+}
+
static void init_once(void *foo)
{
struct efs_inode_info *ei = (struct efs_inode_info *) foo;
return &oi->vfs_inode;
}
+static void exofs_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
+ kmem_cache_free(exofs_inode_cachep, exofs_i(inode));
+}
+
/*
* Remove an inode from the cache
*/
static void exofs_destroy_inode(struct inode *inode)
{
- kmem_cache_free(exofs_inode_cachep, exofs_i(inode));
+ call_rcu(&inode->i_rcu, exofs_i_callback);
}
/*
void *context)
{
struct dentry *dentry, *toput = NULL;
+ struct inode *inode;
if (acceptable(context, result))
return result;
- spin_lock(&dcache_lock);
- list_for_each_entry(dentry, &result->d_inode->i_dentry, d_alias) {
- dget_locked(dentry);
- spin_unlock(&dcache_lock);
+ inode = result->d_inode;
+ spin_lock(&inode->i_lock);
+ list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
+ dget(dentry);
+ spin_unlock(&inode->i_lock);
if (toput)
dput(toput);
if (dentry != result && acceptable(context, dentry)) {
dput(result);
return dentry;
}
- spin_lock(&dcache_lock);
+ spin_lock(&inode->i_lock);
toput = dentry;
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&inode->i_lock);
if (toput)
dput(toput);
}
int
-ext2_check_acl(struct inode *inode, int mask)
+ext2_check_acl(struct inode *inode, int mask, unsigned int flags)
{
- struct posix_acl *acl = ext2_get_acl(inode, ACL_TYPE_ACCESS);
+ struct posix_acl *acl;
+
+ if (flags & IPERM_FLAG_RCU) {
+ if (!negative_cached_acl(inode, ACL_TYPE_ACCESS))
+ return -ECHILD;
+ return -EAGAIN;
+ }
+ acl = ext2_get_acl(inode, ACL_TYPE_ACCESS);
if (IS_ERR(acl))
return PTR_ERR(acl);
if (acl) {
#ifdef CONFIG_EXT2_FS_POSIX_ACL
/* acl.c */
-extern int ext2_check_acl (struct inode *, int);
+extern int ext2_check_acl (struct inode *, int, unsigned int);
extern int ext2_acl_chmod (struct inode *);
extern int ext2_init_acl (struct inode *, struct inode *);
return &ei->vfs_inode;
}
-static void ext2_destroy_inode(struct inode *inode)
+static void ext2_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
}
+static void ext2_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, ext2_i_callback);
+}
+
static void init_once(void *foo)
{
struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
}
int
-ext3_check_acl(struct inode *inode, int mask)
+ext3_check_acl(struct inode *inode, int mask, unsigned int flags)
{
- struct posix_acl *acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
+ struct posix_acl *acl;
+
+ if (flags & IPERM_FLAG_RCU) {
+ if (!negative_cached_acl(inode, ACL_TYPE_ACCESS))
+ return -ECHILD;
+ return -EAGAIN;
+ }
+ acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
if (IS_ERR(acl))
return PTR_ERR(acl);
if (acl) {
#ifdef CONFIG_EXT3_FS_POSIX_ACL
/* acl.c */
-extern int ext3_check_acl (struct inode *, int);
+extern int ext3_check_acl (struct inode *, int, unsigned int);
extern int ext3_acl_chmod (struct inode *);
extern int ext3_init_acl (handle_t *, struct inode *, struct inode *);
return &ei->vfs_inode;
}
+static void ext3_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
+ kmem_cache_free(ext3_inode_cachep, EXT3_I(inode));
+}
+
static void ext3_destroy_inode(struct inode *inode)
{
if (!list_empty(&(EXT3_I(inode)->i_orphan))) {
false);
dump_stack();
}
- kmem_cache_free(ext3_inode_cachep, EXT3_I(inode));
+ call_rcu(&inode->i_rcu, ext3_i_callback);
}
static void init_once(void *foo)
}
int
-ext4_check_acl(struct inode *inode, int mask)
+ext4_check_acl(struct inode *inode, int mask, unsigned int flags)
{
- struct posix_acl *acl = ext4_get_acl(inode, ACL_TYPE_ACCESS);
+ struct posix_acl *acl;
+
+ if (flags & IPERM_FLAG_RCU) {
+ if (!negative_cached_acl(inode, ACL_TYPE_ACCESS))
+ return -ECHILD;
+ return -EAGAIN;
+ }
+ acl = ext4_get_acl(inode, ACL_TYPE_ACCESS);
if (IS_ERR(acl))
return PTR_ERR(acl);
if (acl) {
#ifdef CONFIG_EXT4_FS_POSIX_ACL
/* acl.c */
-extern int ext4_check_acl(struct inode *, int);
+extern int ext4_check_acl(struct inode *, int, unsigned int);
extern int ext4_acl_chmod(struct inode *);
extern int ext4_init_acl(handle_t *, struct inode *, struct inode *);
return drop;
}
+static void ext4_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
+ kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
+}
+
static void ext4_destroy_inode(struct inode *inode)
{
ext4_ioend_wait(inode);
true);
dump_stack();
}
- kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
+ call_rcu(&inode->i_rcu, ext4_i_callback);
}
static void init_once(void *foo)
return &ei->vfs_inode;
}
-static void fat_destroy_inode(struct inode *inode)
+static void fat_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
}
+static void fat_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, fat_i_callback);
+}
+
static void init_once(void *foo)
{
struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
*/
result = d_obtain_alias(inode);
if (!IS_ERR(result))
- result->d_op = sb->s_root->d_op;
+ d_set_d_op(result, sb->s_root->d_op);
return result;
}
parent = d_obtain_alias(inode);
if (!IS_ERR(parent))
- parent->d_op = sb->s_root->d_op;
+ d_set_d_op(parent, sb->s_root->d_op);
out:
unlock_super(sb);
* that the existing dentry can be used. The msdos fs routines will
* return ENOENT or EINVAL as appropriate.
*/
-static int msdos_hash(struct dentry *dentry, struct qstr *qstr)
+static int msdos_hash(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *qstr)
{
struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
unsigned char msdos_name[MSDOS_NAME];
* Compare two msdos names. If either of the names are invalid,
* we fall back to doing the standard name comparison.
*/
-static int msdos_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b)
+static int msdos_cmp(const struct dentry *parent, const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name)
{
- struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
+ struct fat_mount_options *options = &MSDOS_SB(parent->d_sb)->options;
unsigned char a_msdos_name[MSDOS_NAME], b_msdos_name[MSDOS_NAME];
int error;
- error = msdos_format_name(a->name, a->len, a_msdos_name, options);
+ error = msdos_format_name(name->name, name->len, a_msdos_name, options);
if (error)
goto old_compare;
- error = msdos_format_name(b->name, b->len, b_msdos_name, options);
+ error = msdos_format_name(str, len, b_msdos_name, options);
if (error)
goto old_compare;
error = memcmp(a_msdos_name, b_msdos_name, MSDOS_NAME);
old_compare:
error = 1;
- if (a->len == b->len)
- error = memcmp(a->name, b->name, a->len);
+ if (name->len == len)
+ error = memcmp(name->name, str, len);
goto out;
}
}
out:
unlock_super(sb);
- dentry->d_op = &msdos_dentry_operations;
+ d_set_d_op(dentry, &msdos_dentry_operations);
dentry = d_splice_alias(inode, dentry);
if (dentry)
- dentry->d_op = &msdos_dentry_operations;
+ d_set_d_op(dentry, &msdos_dentry_operations);
return dentry;
error:
}
sb->s_flags |= MS_NOATIME;
- sb->s_root->d_op = &msdos_dentry_operations;
+ d_set_d_op(sb->s_root, &msdos_dentry_operations);
unlock_super(sb);
return 0;
}
static int vfat_revalidate(struct dentry *dentry, struct nameidata *nd)
{
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
/* This is not negative dentry. Always valid. */
if (dentry->d_inode)
return 1;
static int vfat_revalidate_ci(struct dentry *dentry, struct nameidata *nd)
{
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
/*
* This is not negative dentry. Always valid.
*
}
/* returns the length of a struct qstr, ignoring trailing dots */
-static unsigned int vfat_striptail_len(struct qstr *qstr)
+static unsigned int __vfat_striptail_len(unsigned int len, const char *name)
{
- unsigned int len = qstr->len;
-
- while (len && qstr->name[len - 1] == '.')
+ while (len && name[len - 1] == '.')
len--;
return len;
}
+static unsigned int vfat_striptail_len(const struct qstr *qstr)
+{
+ return __vfat_striptail_len(qstr->len, qstr->name);
+}
+
/*
* Compute the hash for the vfat name corresponding to the dentry.
* Note: if the name is invalid, we leave the hash code unchanged so
* that the existing dentry can be used. The vfat fs routines will
* return ENOENT or EINVAL as appropriate.
*/
-static int vfat_hash(struct dentry *dentry, struct qstr *qstr)
+static int vfat_hash(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *qstr)
{
qstr->hash = full_name_hash(qstr->name, vfat_striptail_len(qstr));
return 0;
* that the existing dentry can be used. The vfat fs routines will
* return ENOENT or EINVAL as appropriate.
*/
-static int vfat_hashi(struct dentry *dentry, struct qstr *qstr)
+static int vfat_hashi(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *qstr)
{
- struct nls_table *t = MSDOS_SB(dentry->d_inode->i_sb)->nls_io;
+ struct nls_table *t = MSDOS_SB(dentry->d_sb)->nls_io;
const unsigned char *name;
unsigned int len;
unsigned long hash;
/*
* Case insensitive compare of two vfat names.
*/
-static int vfat_cmpi(struct dentry *dentry, struct qstr *a, struct qstr *b)
+static int vfat_cmpi(const struct dentry *parent, const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name)
{
- struct nls_table *t = MSDOS_SB(dentry->d_inode->i_sb)->nls_io;
+ struct nls_table *t = MSDOS_SB(parent->d_sb)->nls_io;
unsigned int alen, blen;
/* A filename cannot end in '.' or we treat it like it has none */
- alen = vfat_striptail_len(a);
- blen = vfat_striptail_len(b);
+ alen = vfat_striptail_len(name);
+ blen = __vfat_striptail_len(len, str);
if (alen == blen) {
- if (nls_strnicmp(t, a->name, b->name, alen) == 0)
+ if (nls_strnicmp(t, name->name, str, alen) == 0)
return 0;
}
return 1;
/*
* Case sensitive compare of two vfat names.
*/
-static int vfat_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b)
+static int vfat_cmp(const struct dentry *parent, const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name)
{
unsigned int alen, blen;
/* A filename cannot end in '.' or we treat it like it has none */
- alen = vfat_striptail_len(a);
- blen = vfat_striptail_len(b);
+ alen = vfat_striptail_len(name);
+ blen = __vfat_striptail_len(len, str);
if (alen == blen) {
- if (strncmp(a->name, b->name, alen) == 0)
+ if (strncmp(name->name, str, alen) == 0)
return 0;
}
return 1;
out:
unlock_super(sb);
- dentry->d_op = sb->s_root->d_op;
+ d_set_d_op(dentry, sb->s_root->d_op);
dentry->d_time = dentry->d_parent->d_inode->i_version;
dentry = d_splice_alias(inode, dentry);
if (dentry) {
- dentry->d_op = sb->s_root->d_op;
+ d_set_d_op(dentry, sb->s_root->d_op);
dentry->d_time = dentry->d_parent->d_inode->i_version;
}
return dentry;
}
if (MSDOS_SB(sb)->options.name_check != 's')
- sb->s_root->d_op = &vfat_ci_dentry_ops;
+ d_set_d_op(sb->s_root, &vfat_ci_dentry_ops);
else
- sb->s_root->d_op = &vfat_dentry_ops;
+ d_set_d_op(sb->s_root, &vfat_dentry_ops);
unlock_super(sb);
return 0;
tmp = &(*tmp)->next;
}
write_unlock(&file_systems_lock);
+
+ synchronize_rcu();
+
return -EINVAL;
}
return ip;
}
+static void vxfs_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
+ kmem_cache_free(vxfs_inode_cachep, inode->i_private);
+}
+
/**
* vxfs_evict_inode - remove inode from main memory
* @ip: inode to discard.
{
truncate_inode_pages(&ip->i_data, 0);
end_writeback(ip);
- kmem_cache_free(vxfs_inode_cachep, ip->i_private);
+ call_rcu(&ip->i_rcu, vxfs_i_callback);
}
struct path old_root;
spin_lock(&fs->lock);
+ write_seqcount_begin(&fs->seq);
old_root = fs->root;
fs->root = *path;
- path_get(path);
+ path_get_long(path);
+ write_seqcount_end(&fs->seq);
spin_unlock(&fs->lock);
if (old_root.dentry)
- path_put(&old_root);
+ path_put_long(&old_root);
}
/*
struct path old_pwd;
spin_lock(&fs->lock);
+ write_seqcount_begin(&fs->seq);
old_pwd = fs->pwd;
fs->pwd = *path;
- path_get(path);
+ path_get_long(path);
+ write_seqcount_end(&fs->seq);
spin_unlock(&fs->lock);
if (old_pwd.dentry)
- path_put(&old_pwd);
+ path_put_long(&old_pwd);
}
void chroot_fs_refs(struct path *old_root, struct path *new_root)
fs = p->fs;
if (fs) {
spin_lock(&fs->lock);
+ write_seqcount_begin(&fs->seq);
if (fs->root.dentry == old_root->dentry
&& fs->root.mnt == old_root->mnt) {
- path_get(new_root);
+ path_get_long(new_root);
fs->root = *new_root;
count++;
}
if (fs->pwd.dentry == old_root->dentry
&& fs->pwd.mnt == old_root->mnt) {
- path_get(new_root);
+ path_get_long(new_root);
fs->pwd = *new_root;
count++;
}
+ write_seqcount_end(&fs->seq);
spin_unlock(&fs->lock);
}
task_unlock(p);
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
while (count--)
- path_put(old_root);
+ path_put_long(old_root);
}
void free_fs_struct(struct fs_struct *fs)
{
- path_put(&fs->root);
- path_put(&fs->pwd);
+ path_put_long(&fs->root);
+ path_put_long(&fs->pwd);
kmem_cache_free(fs_cachep, fs);
}
int kill;
task_lock(tsk);
spin_lock(&fs->lock);
+ write_seqcount_begin(&fs->seq);
tsk->fs = NULL;
kill = !--fs->users;
+ write_seqcount_end(&fs->seq);
spin_unlock(&fs->lock);
task_unlock(tsk);
if (kill)
fs->users = 1;
fs->in_exec = 0;
spin_lock_init(&fs->lock);
+ seqcount_init(&fs->seq);
fs->umask = old->umask;
- get_fs_root_and_pwd(old, &fs->root, &fs->pwd);
+
+ spin_lock(&old->lock);
+ fs->root = old->root;
+ path_get_long(&fs->root);
+ fs->pwd = old->pwd;
+ path_get_long(&fs->pwd);
+ spin_unlock(&old->lock);
}
return fs;
}
struct fs_struct init_fs = {
.users = 1,
.lock = __SPIN_LOCK_UNLOCKED(init_fs.lock),
+ .seq = SEQCNT_ZERO,
.umask = 0022,
};
*/
static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd)
{
- struct inode *inode = entry->d_inode;
+ struct inode *inode;
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ inode = entry->d_inode;
if (inode && is_bad_inode(inode))
return 0;
else if (fuse_dentry_time(entry) < get_jiffies_64()) {
}
entry = newent ? newent : entry;
- entry->d_op = &fuse_dentry_operations;
+ d_set_d_op(entry, &fuse_dentry_operations);
if (outarg_valid)
fuse_change_entry_timeout(entry, &outarg);
else
* access request is sent. Execute permission is still checked
* locally based on file mode.
*/
-static int fuse_permission(struct inode *inode, int mask)
+static int fuse_permission(struct inode *inode, int mask, unsigned int flags)
{
struct fuse_conn *fc = get_fuse_conn(inode);
bool refreshed = false;
int err = 0;
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
+
if (!fuse_allow_task(fc, current))
return -EACCES;
}
if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
- err = generic_permission(inode, mask, NULL);
+ err = generic_permission(inode, mask, flags, NULL);
/* If permission is denied, try to refresh file
attributes. This is also needed, because the root
if (err == -EACCES && !refreshed) {
err = fuse_do_getattr(inode, NULL, NULL);
if (!err)
- err = generic_permission(inode, mask, NULL);
+ err = generic_permission(inode, mask,
+ flags, NULL);
}
/* Note: the opposite of the above test does not
return inode;
}
+static void fuse_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
+ kmem_cache_free(fuse_inode_cachep, inode);
+}
+
static void fuse_destroy_inode(struct inode *inode)
{
struct fuse_inode *fi = get_fuse_inode(inode);
BUG_ON(!list_empty(&fi->queued_writes));
if (fi->forget_req)
fuse_request_free(fi->forget_req);
- kmem_cache_free(fuse_inode_cachep, inode);
+ call_rcu(&inode->i_rcu, fuse_i_callback);
}
void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
entry = d_obtain_alias(inode);
if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID) {
- entry->d_op = &fuse_dentry_operations;
+ d_set_d_op(entry, &fuse_dentry_operations);
fuse_invalidate_entry_cache(entry);
}
parent = d_obtain_alias(inode);
if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID) {
- parent->d_op = &fuse_dentry_operations;
+ d_set_d_op(parent, &fuse_dentry_operations);
fuse_invalidate_entry_cache(parent);
}
}
int
-generic_check_acl(struct inode *inode, int mask)
+generic_check_acl(struct inode *inode, int mask, unsigned int flags)
{
- struct posix_acl *acl = get_cached_acl(inode, ACL_TYPE_ACCESS);
-
- if (acl) {
- int error = posix_acl_permission(inode, acl, mask);
- posix_acl_release(acl);
- return error;
+ if (flags & IPERM_FLAG_RCU) {
+ if (!negative_cached_acl(inode, ACL_TYPE_ACCESS))
+ return -ECHILD;
+ } else {
+ struct posix_acl *acl;
+
+ acl = get_cached_acl(inode, ACL_TYPE_ACCESS);
+ if (acl) {
+ int error = posix_acl_permission(inode, acl, mask);
+ posix_acl_release(acl);
+ return error;
+ }
}
return -EAGAIN;
}
* Returns: errno
*/
-int gfs2_check_acl(struct inode *inode, int mask)
+int gfs2_check_acl(struct inode *inode, int mask, unsigned int flags)
{
struct posix_acl *acl;
int error;
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
+
acl = gfs2_acl_get(GFS2_I(inode), ACL_TYPE_ACCESS);
if (IS_ERR(acl))
return PTR_ERR(acl);
#define GFS2_POSIX_ACL_DEFAULT "posix_acl_default"
#define GFS2_ACL_MAX_ENTRIES 25
-extern int gfs2_check_acl(struct inode *inode, int mask);
+extern int gfs2_check_acl(struct inode *inode, int mask, unsigned int);
extern int gfs2_acl_create(struct gfs2_inode *dip, struct inode *inode);
extern int gfs2_acl_chmod(struct gfs2_inode *ip, struct iattr *attr);
extern const struct xattr_handler gfs2_xattr_system_handler;
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/gfs2_ondisk.h>
+#include <linux/namei.h>
#include <linux/crc32.h>
#include "gfs2.h"
static int gfs2_drevalidate(struct dentry *dentry, struct nameidata *nd)
{
- struct dentry *parent = dget_parent(dentry);
- struct gfs2_sbd *sdp = GFS2_SB(parent->d_inode);
- struct gfs2_inode *dip = GFS2_I(parent->d_inode);
- struct inode *inode = dentry->d_inode;
+ struct dentry *parent;
+ struct gfs2_sbd *sdp;
+ struct gfs2_inode *dip;
+ struct inode *inode;
struct gfs2_holder d_gh;
struct gfs2_inode *ip = NULL;
int error;
int had_lock = 0;
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ parent = dget_parent(dentry);
+ sdp = GFS2_SB(parent->d_inode);
+ dip = GFS2_I(parent->d_inode);
+ inode = dentry->d_inode;
+
if (inode) {
if (is_bad_inode(inode))
goto invalid;
return 0;
}
-static int gfs2_dhash(struct dentry *dentry, struct qstr *str)
+static int gfs2_dhash(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *str)
{
str->hash = gfs2_disk_hash(str->name, str->len);
return 0;
}
-static int gfs2_dentry_delete(struct dentry *dentry)
+static int gfs2_dentry_delete(const struct dentry *dentry)
{
struct gfs2_inode *ginode;
dentry = d_obtain_alias(gfs2_lookupi(child->d_inode, &gfs2_qdotdot, 1));
if (!IS_ERR(dentry))
- dentry->d_op = &gfs2_dops;
+ d_set_d_op(dentry, &gfs2_dops);
return dentry;
}
out_inode:
dentry = d_obtain_alias(inode);
if (!IS_ERR(dentry))
- dentry->d_op = &gfs2_dops;
+ d_set_d_op(dentry, &gfs2_dops);
return dentry;
}
!capable(CAP_LINUX_IMMUTABLE))
goto out;
if (!IS_IMMUTABLE(inode)) {
- error = gfs2_permission(inode, MAY_WRITE);
+ error = gfs2_permission(inode, MAY_WRITE, 0);
if (error)
goto out;
}
}
if (!is_root) {
- error = gfs2_permission(dir, MAY_EXEC);
+ error = gfs2_permission(dir, MAY_EXEC, 0);
if (error)
goto out;
}
{
int error;
- error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC);
+ error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC, 0);
if (error)
return error;
extern struct inode *gfs2_createi(struct gfs2_holder *ghs,
const struct qstr *name,
unsigned int mode, dev_t dev);
-extern int gfs2_permission(struct inode *inode, int mask);
+extern int gfs2_permission(struct inode *inode, int mask, unsigned int flags);
extern int gfs2_setattr_simple(struct gfs2_inode *ip, struct iattr *attr);
extern struct inode *gfs2_lookup_simple(struct inode *dip, const char *name);
extern void gfs2_dinode_out(const struct gfs2_inode *ip, void *buf);
iput(inode);
return -ENOMEM;
}
- dentry->d_op = &gfs2_dops;
+ d_set_d_op(dentry, &gfs2_dops);
*dptr = dentry;
return 0;
}
{
struct inode *inode = NULL;
- dentry->d_op = &gfs2_dops;
+ d_set_d_op(dentry, &gfs2_dops);
inode = gfs2_lookupi(dir, &dentry->d_name, 0);
if (inode && IS_ERR(inode))
if (error)
goto out_child;
- error = gfs2_permission(dir, MAY_WRITE | MAY_EXEC);
+ error = gfs2_permission(dir, MAY_WRITE | MAY_EXEC, 0);
if (error)
goto out_gunlock;
if (IS_APPEND(&dip->i_inode))
return -EPERM;
- error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC);
+ error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC, 0);
if (error)
return error;
}
}
} else {
- error = gfs2_permission(ndir, MAY_WRITE | MAY_EXEC);
+ error = gfs2_permission(ndir, MAY_WRITE | MAY_EXEC, 0);
if (error)
goto out_gunlock;
/* Check out the dir to be renamed */
if (dir_rename) {
- error = gfs2_permission(odentry->d_inode, MAY_WRITE);
+ error = gfs2_permission(odentry->d_inode, MAY_WRITE, 0);
if (error)
goto out_gunlock;
}
* Returns: errno
*/
-int gfs2_permission(struct inode *inode, int mask)
+int gfs2_permission(struct inode *inode, int mask, unsigned int flags)
{
- struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_inode *ip;
struct gfs2_holder i_gh;
int error;
int unlock = 0;
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
+
+ ip = GFS2_I(inode);
if (gfs2_glock_is_locked_by_me(ip->i_gl) == NULL) {
error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
if (error)
if ((mask & MAY_WRITE) && IS_IMMUTABLE(inode))
error = -EACCES;
else
- error = generic_permission(inode, mask, gfs2_check_acl);
+ error = generic_permission(inode, mask, flags, gfs2_check_acl);
if (unlock)
gfs2_glock_dq_uninit(&i_gh);
return &ip->i_inode;
}
-static void gfs2_destroy_inode(struct inode *inode)
+static void gfs2_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(gfs2_inode_cachep, inode);
}
+static void gfs2_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, gfs2_i_callback);
+}
+
const struct super_operations gfs2_super_ops = {
.alloc_inode = gfs2_alloc_inode,
.destroy_inode = gfs2_destroy_inode,
struct inode *inode = NULL;
int res;
- dentry->d_op = &hfs_dentry_operations;
+ d_set_d_op(dentry, &hfs_dentry_operations);
hfs_find_init(HFS_SB(dir->i_sb)->cat_tree, &fd);
hfs_cat_build_key(dir->i_sb, fd.search_key, dir->i_ino, &dentry->d_name);
/* string.c */
extern const struct dentry_operations hfs_dentry_operations;
-extern int hfs_hash_dentry(struct dentry *, struct qstr *);
+extern int hfs_hash_dentry(const struct dentry *, const struct inode *,
+ struct qstr *);
extern int hfs_strcmp(const unsigned char *, unsigned int,
const unsigned char *, unsigned int);
-extern int hfs_compare_dentry(struct dentry *, struct qstr *, struct qstr *);
+extern int hfs_compare_dentry(const struct dentry *parent,
+ const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name);
/* trans.c */
extern void hfs_asc2mac(struct super_block *, struct hfs_name *, struct qstr *);
/*
* Hash a string to an integer in a case-independent way
*/
-int hfs_hash_dentry(struct dentry *dentry, struct qstr *this)
+int hfs_hash_dentry(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *this)
{
const unsigned char *name = this->name;
unsigned int hash, len = this->len;
* Test for equality of two strings in the HFS filename character ordering.
* return 1 on failure and 0 on success
*/
-int hfs_compare_dentry(struct dentry *dentry, struct qstr *s1, struct qstr *s2)
+int hfs_compare_dentry(const struct dentry *parent, const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name)
{
const unsigned char *n1, *n2;
- int len;
- len = s1->len;
if (len >= HFS_NAMELEN) {
- if (s2->len < HFS_NAMELEN)
+ if (name->len < HFS_NAMELEN)
return 1;
len = HFS_NAMELEN;
- } else if (len != s2->len)
+ } else if (len != name->len)
return 1;
- n1 = s1->name;
- n2 = s2->name;
+ n1 = str;
+ n2 = name->name;
while (len--) {
if (caseorder[*n1++] != caseorder[*n2++])
return 1;
return i ? &i->vfs_inode : NULL;
}
-static void hfs_destroy_inode(struct inode *inode)
+static void hfs_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
}
+static void hfs_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, hfs_i_callback);
+}
+
static const struct super_operations hfs_super_operations = {
.alloc_inode = hfs_alloc_inode,
.destroy_inode = hfs_destroy_inode,
if (!sb->s_root)
goto bail_iput;
- sb->s_root->d_op = &hfs_dentry_operations;
+ d_set_d_op(sb->s_root, &hfs_dentry_operations);
/* everything's okay */
return 0;
* This file contains the code to do various system dependent things.
*/
+#include <linux/namei.h>
#include "hfs_fs.h"
/* dentry case-handling: just lowercase everything */
static int hfs_revalidate_dentry(struct dentry *dentry, struct nameidata *nd)
{
- struct inode *inode = dentry->d_inode;
+ struct inode *inode;
int diff;
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ inode = dentry->d_inode;
if(!inode)
return 1;
sb = dir->i_sb;
- dentry->d_op = &hfsplus_dentry_operations;
+ d_set_d_op(dentry, &hfsplus_dentry_operations);
dentry->d_fsdata = NULL;
hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino, &dentry->d_name);
int hfsplus_strcmp(const struct hfsplus_unistr *, const struct hfsplus_unistr *);
int hfsplus_uni2asc(struct super_block *, const struct hfsplus_unistr *, char *, int *);
int hfsplus_asc2uni(struct super_block *, struct hfsplus_unistr *, const char *, int);
-int hfsplus_hash_dentry(struct dentry *dentry, struct qstr *str);
-int hfsplus_compare_dentry(struct dentry *dentry, struct qstr *s1, struct qstr *s2);
+int hfsplus_hash_dentry(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *str);
+int hfsplus_compare_dentry(const struct dentry *parent,
+ const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name);
/* wrapper.c */
int hfsplus_read_wrapper(struct super_block *);
err = -ENOMEM;
goto cleanup;
}
- sb->s_root->d_op = &hfsplus_dentry_operations;
+ d_set_d_op(sb->s_root, &hfsplus_dentry_operations);
str.len = sizeof(HFSP_HIDDENDIR_NAME) - 1;
str.name = HFSP_HIDDENDIR_NAME;
return i ? &i->vfs_inode : NULL;
}
-static void hfsplus_destroy_inode(struct inode *inode)
+static void hfsplus_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(hfsplus_inode_cachep, HFSPLUS_I(inode));
}
+static void hfsplus_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, hfsplus_i_callback);
+}
+
#define HFSPLUS_INODE_SIZE sizeof(struct hfsplus_inode_info)
static struct dentry *hfsplus_mount(struct file_system_type *fs_type,
* Composed unicode characters are decomposed and case-folding is performed
* if the appropriate bits are (un)set on the superblock.
*/
-int hfsplus_hash_dentry(struct dentry *dentry, struct qstr *str)
+int hfsplus_hash_dentry(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *str)
{
struct super_block *sb = dentry->d_sb;
const char *astr;
* Composed unicode characters are decomposed and case-folding is performed
* if the appropriate bits are (un)set on the superblock.
*/
-int hfsplus_compare_dentry(struct dentry *dentry, struct qstr *s1, struct qstr *s2)
+int hfsplus_compare_dentry(const struct dentry *parent,
+ const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name)
{
- struct super_block *sb = dentry->d_sb;
+ struct super_block *sb = parent->d_sb;
int casefold, decompose, size;
int dsize1, dsize2, len1, len2;
const u16 *dstr1, *dstr2;
casefold = test_bit(HFSPLUS_SB_CASEFOLD, &HFSPLUS_SB(sb)->flags);
decompose = !test_bit(HFSPLUS_SB_NODECOMPOSE, &HFSPLUS_SB(sb)->flags);
- astr1 = s1->name;
- len1 = s1->len;
- astr2 = s2->name;
- len2 = s2->len;
+ astr1 = str;
+ len1 = len;
+ astr2 = name->name;
+ len2 = name->len;
dsize1 = dsize2 = 0;
dstr1 = dstr2 = NULL;
#define FILE_HOSTFS_I(file) HOSTFS_I((file)->f_path.dentry->d_inode)
-static int hostfs_d_delete(struct dentry *dentry)
+static int hostfs_d_delete(const struct dentry *dentry)
{
return 1;
}
static char *__dentry_name(struct dentry *dentry, char *name)
{
- char *p = __dentry_path(dentry, name, PATH_MAX);
+ char *p = dentry_path_raw(dentry, name, PATH_MAX);
char *root;
size_t len;
- spin_unlock(&dcache_lock);
-
root = dentry->d_sb->s_fs_info;
len = strlen(root);
if (IS_ERR(p)) {
if (!name)
return NULL;
- spin_lock(&dcache_lock);
return __dentry_name(dentry, name); /* will unlock */
}
static char *inode_name(struct inode *ino)
{
struct dentry *dentry;
- char *name = __getname();
- if (!name)
- return NULL;
+ char *name;
- spin_lock(&dcache_lock);
- if (list_empty(&ino->i_dentry)) {
- spin_unlock(&dcache_lock);
- __putname(name);
+ dentry = d_find_alias(ino);
+ if (!dentry)
return NULL;
- }
- dentry = list_first_entry(&ino->i_dentry, struct dentry, d_alias);
- return __dentry_name(dentry, name); /* will unlock */
+
+ name = dentry_name(dentry);
+
+ dput(dentry);
+
+ return name;
}
static char *follow_link(char *link)
}
}
-static void hostfs_destroy_inode(struct inode *inode)
+static void hostfs_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kfree(HOSTFS_I(inode));
}
+static void hostfs_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, hostfs_i_callback);
+}
+
static int hostfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
{
const char *root_path = vfs->mnt_sb->s_fs_info;
goto out_put;
d_add(dentry, inode);
- dentry->d_op = &hostfs_dentry_ops;
+ d_set_d_op(dentry, &hostfs_dentry_ops);
return NULL;
out_put:
return err;
}
-int hostfs_permission(struct inode *ino, int desired)
+int hostfs_permission(struct inode *ino, int desired, unsigned int flags)
{
char *name;
int r = 0, w = 0, x = 0, err;
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
+
if (desired & MAY_READ) r = 1;
if (desired & MAY_WRITE) w = 1;
if (desired & MAY_EXEC) x = 1;
err = access_file(name, r, w, x);
__putname(name);
if (!err)
- err = generic_permission(ino, desired, NULL);
+ err = generic_permission(ino, desired, flags, NULL);
return err;
}
* Note: the dentry argument is the parent dentry.
*/
-static int hpfs_hash_dentry(struct dentry *dentry, struct qstr *qstr)
+static int hpfs_hash_dentry(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *qstr)
{
unsigned long hash;
int i;
return 0;
}
-static int hpfs_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b)
+static int hpfs_compare_dentry(const struct dentry *parent,
+ const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name)
{
- unsigned al=a->len;
- unsigned bl=b->len;
- hpfs_adjust_length(a->name, &al);
+ unsigned al = len;
+ unsigned bl = name->len;
+
+ hpfs_adjust_length(str, &al);
/*hpfs_adjust_length(b->name, &bl);*/
- /* 'a' is the qstr of an already existing dentry, so the name
- * must be valid. 'b' must be validated first.
+
+ /*
+ * 'str' is the nane of an already existing dentry, so the name
+ * must be valid. 'name' must be validated first.
*/
- if (hpfs_chk_name(b->name, &bl))
+ if (hpfs_chk_name(name->name, &bl))
return 1;
- if (hpfs_compare_names(dentry->d_sb, a->name, al, b->name, bl, 0))
+ if (hpfs_compare_names(parent->d_sb, str, al, name->name, bl, 0))
return 1;
return 0;
}
void hpfs_set_dentry_operations(struct dentry *dentry)
{
- dentry->d_op = &hpfs_dentry_operations;
+ d_set_d_op(dentry, &hpfs_dentry_operations);
}
unlock_kernel();
return -ENOSPC;
}
- if (generic_permission(inode, MAY_WRITE, NULL) ||
+ if (generic_permission(inode, MAY_WRITE, 0, NULL) ||
!S_ISREG(inode->i_mode) ||
get_write_access(inode)) {
d_rehash(dentry);
return &ei->vfs_inode;
}
-static void hpfs_destroy_inode(struct inode *inode)
+static void hpfs_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(hpfs_inode_cachep, hpfs_i(inode));
}
+static void hpfs_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, hpfs_i_callback);
+}
+
static void init_once(void *foo)
{
struct hpfs_inode_info *ei = (struct hpfs_inode_info *) foo;
mntput(ino->i_sb->s_fs_info);
}
-static void hppfs_destroy_inode(struct inode *inode)
+static void hppfs_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kfree(HPPFS_I(inode));
}
+static void hppfs_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, hppfs_i_callback);
+}
+
static const struct super_operations hppfs_sbops = {
.alloc_inode = hppfs_alloc_inode,
.destroy_inode = hppfs_destroy_inode,
return &p->vfs_inode;
}
+static void hugetlbfs_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
+ kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
+}
+
static void hugetlbfs_destroy_inode(struct inode *inode)
{
hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb));
mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy);
- kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
+ call_rcu(&inode->i_rcu, hugetlbfs_i_callback);
}
static const struct address_space_operations hugetlbfs_aops = {
*/
struct inodes_stat_t inodes_stat;
-static struct percpu_counter nr_inodes __cacheline_aligned_in_smp;
-static struct percpu_counter nr_inodes_unused __cacheline_aligned_in_smp;
+static DEFINE_PER_CPU(unsigned int, nr_inodes);
static struct kmem_cache *inode_cachep __read_mostly;
-static inline int get_nr_inodes(void)
+static int get_nr_inodes(void)
{
- return percpu_counter_sum_positive(&nr_inodes);
+ int i;
+ int sum = 0;
+ for_each_possible_cpu(i)
+ sum += per_cpu(nr_inodes, i);
+ return sum < 0 ? 0 : sum;
}
static inline int get_nr_inodes_unused(void)
{
- return percpu_counter_sum_positive(&nr_inodes_unused);
+ return inodes_stat.nr_unused;
}
int get_nr_dirty_inodes(void)
{
+ /* not actually dirty inodes, but a wild approximation */
int nr_dirty = get_nr_inodes() - get_nr_inodes_unused();
return nr_dirty > 0 ? nr_dirty : 0;
-
}
/*
void __user *buffer, size_t *lenp, loff_t *ppos)
{
inodes_stat.nr_inodes = get_nr_inodes();
- inodes_stat.nr_unused = get_nr_inodes_unused();
return proc_dointvec(table, write, buffer, lenp, ppos);
}
#endif
inode->i_fsnotify_mask = 0;
#endif
- percpu_counter_inc(&nr_inodes);
+ this_cpu_inc(nr_inodes);
return 0;
out:
return inode;
}
+void free_inode_nonrcu(struct inode *inode)
+{
+ kmem_cache_free(inode_cachep, inode);
+}
+EXPORT_SYMBOL(free_inode_nonrcu);
+
void __destroy_inode(struct inode *inode)
{
BUG_ON(inode_has_buffers(inode));
if (inode->i_default_acl && inode->i_default_acl != ACL_NOT_CACHED)
posix_acl_release(inode->i_default_acl);
#endif
- percpu_counter_dec(&nr_inodes);
+ this_cpu_dec(nr_inodes);
}
EXPORT_SYMBOL(__destroy_inode);
+static void i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
+ kmem_cache_free(inode_cachep, inode);
+}
+
static void destroy_inode(struct inode *inode)
{
BUG_ON(!list_empty(&inode->i_lru));
if (inode->i_sb->s_op->destroy_inode)
inode->i_sb->s_op->destroy_inode(inode);
else
- kmem_cache_free(inode_cachep, (inode));
+ call_rcu(&inode->i_rcu, i_callback);
}
/*
{
if (list_empty(&inode->i_lru)) {
list_add(&inode->i_lru, &inode_lru);
- percpu_counter_inc(&nr_inodes_unused);
+ inodes_stat.nr_unused++;
}
}
{
if (!list_empty(&inode->i_lru)) {
list_del_init(&inode->i_lru);
- percpu_counter_dec(&nr_inodes_unused);
+ inodes_stat.nr_unused--;
}
}
BUG_ON(!(inode->i_state & I_FREEING));
BUG_ON(inode->i_state & I_CLEAR);
inode_sync_wait(inode);
+ /* don't need i_lock here, no concurrent mods to i_state */
inode->i_state = I_FREEING | I_CLEAR;
}
EXPORT_SYMBOL(end_writeback);
list_move(&inode->i_lru, &dispose);
list_del_init(&inode->i_wb_list);
if (!(inode->i_state & (I_DIRTY | I_SYNC)))
- percpu_counter_dec(&nr_inodes_unused);
+ inodes_stat.nr_unused--;
}
spin_unlock(&inode_lock);
list_move(&inode->i_lru, &dispose);
list_del_init(&inode->i_wb_list);
if (!(inode->i_state & (I_DIRTY | I_SYNC)))
- percpu_counter_dec(&nr_inodes_unused);
+ inodes_stat.nr_unused--;
}
spin_unlock(&inode_lock);
if (atomic_read(&inode->i_count) ||
(inode->i_state & ~I_REFERENCED)) {
list_del_init(&inode->i_lru);
- percpu_counter_dec(&nr_inodes_unused);
+ inodes_stat.nr_unused--;
continue;
}
*/
list_move(&inode->i_lru, &freeable);
list_del_init(&inode->i_wb_list);
- percpu_counter_dec(&nr_inodes_unused);
+ inodes_stat.nr_unused--;
}
if (current_is_kswapd())
__count_vm_events(KSWAPD_INODESTEAL, reap);
SLAB_MEM_SPREAD),
init_once);
register_shrinker(&icache_shrinker);
- percpu_counter_init(&nr_inodes, 0);
- percpu_counter_init(&nr_inodes_unused, 0);
/* Hash may have been set up in inode_init_early */
if (!hashdist)
extern void free_vfsmnt(struct vfsmount *);
extern struct vfsmount *alloc_vfsmnt(const char *);
+extern unsigned int mnt_get_count(struct vfsmount *mnt);
extern struct vfsmount *__lookup_mnt(struct vfsmount *, struct dentry *, int);
extern void mnt_set_mountpoint(struct vfsmount *, struct dentry *,
struct vfsmount *);
#define BEQUIET
-static int isofs_hashi(struct dentry *parent, struct qstr *qstr);
-static int isofs_hash(struct dentry *parent, struct qstr *qstr);
-static int isofs_dentry_cmpi(struct dentry *dentry, struct qstr *a, struct qstr *b);
-static int isofs_dentry_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b);
+static int isofs_hashi(const struct dentry *parent, const struct inode *inode,
+ struct qstr *qstr);
+static int isofs_hash(const struct dentry *parent, const struct inode *inode,
+ struct qstr *qstr);
+static int isofs_dentry_cmpi(const struct dentry *parent,
+ const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name);
+static int isofs_dentry_cmp(const struct dentry *parent,
+ const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name);
#ifdef CONFIG_JOLIET
-static int isofs_hashi_ms(struct dentry *parent, struct qstr *qstr);
-static int isofs_hash_ms(struct dentry *parent, struct qstr *qstr);
-static int isofs_dentry_cmpi_ms(struct dentry *dentry, struct qstr *a, struct qstr *b);
-static int isofs_dentry_cmp_ms(struct dentry *dentry, struct qstr *a, struct qstr *b);
+static int isofs_hashi_ms(const struct dentry *parent, const struct inode *inode,
+ struct qstr *qstr);
+static int isofs_hash_ms(const struct dentry *parent, const struct inode *inode,
+ struct qstr *qstr);
+static int isofs_dentry_cmpi_ms(const struct dentry *parent,
+ const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name);
+static int isofs_dentry_cmp_ms(const struct dentry *parent,
+ const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name);
#endif
static void isofs_put_super(struct super_block *sb)
return &ei->vfs_inode;
}
-static void isofs_destroy_inode(struct inode *inode)
+static void isofs_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(isofs_inode_cachep, ISOFS_I(inode));
}
+static void isofs_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, isofs_i_callback);
+}
+
static void init_once(void *foo)
{
struct iso_inode_info *ei = foo;
* Compute the hash for the isofs name corresponding to the dentry.
*/
static int
-isofs_hash_common(struct dentry *dentry, struct qstr *qstr, int ms)
+isofs_hash_common(const struct dentry *dentry, struct qstr *qstr, int ms)
{
const char *name;
int len;
* Compute the hash for the isofs name corresponding to the dentry.
*/
static int
-isofs_hashi_common(struct dentry *dentry, struct qstr *qstr, int ms)
+isofs_hashi_common(const struct dentry *dentry, struct qstr *qstr, int ms)
{
const char *name;
int len;
}
/*
- * Case insensitive compare of two isofs names.
- */
-static int isofs_dentry_cmpi_common(struct dentry *dentry, struct qstr *a,
- struct qstr *b, int ms)
-{
- int alen, blen;
-
- /* A filename cannot end in '.' or we treat it like it has none */
- alen = a->len;
- blen = b->len;
- if (ms) {
- while (alen && a->name[alen-1] == '.')
- alen--;
- while (blen && b->name[blen-1] == '.')
- blen--;
- }
- if (alen == blen) {
- if (strnicmp(a->name, b->name, alen) == 0)
- return 0;
- }
- return 1;
-}
-
-/*
- * Case sensitive compare of two isofs names.
+ * Compare of two isofs names.
*/
-static int isofs_dentry_cmp_common(struct dentry *dentry, struct qstr *a,
- struct qstr *b, int ms)
+static int isofs_dentry_cmp_common(
+ unsigned int len, const char *str,
+ const struct qstr *name, int ms, int ci)
{
int alen, blen;
/* A filename cannot end in '.' or we treat it like it has none */
- alen = a->len;
- blen = b->len;
+ alen = name->len;
+ blen = len;
if (ms) {
- while (alen && a->name[alen-1] == '.')
+ while (alen && name->name[alen-1] == '.')
alen--;
- while (blen && b->name[blen-1] == '.')
+ while (blen && str[blen-1] == '.')
blen--;
}
if (alen == blen) {
- if (strncmp(a->name, b->name, alen) == 0)
- return 0;
+ if (ci) {
+ if (strnicmp(name->name, str, alen) == 0)
+ return 0;
+ } else {
+ if (strncmp(name->name, str, alen) == 0)
+ return 0;
+ }
}
return 1;
}
static int
-isofs_hash(struct dentry *dentry, struct qstr *qstr)
+isofs_hash(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *qstr)
{
return isofs_hash_common(dentry, qstr, 0);
}
static int
-isofs_hashi(struct dentry *dentry, struct qstr *qstr)
+isofs_hashi(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *qstr)
{
return isofs_hashi_common(dentry, qstr, 0);
}
static int
-isofs_dentry_cmp(struct dentry *dentry,struct qstr *a,struct qstr *b)
+isofs_dentry_cmp(const struct dentry *parent, const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name)
{
- return isofs_dentry_cmp_common(dentry, a, b, 0);
+ return isofs_dentry_cmp_common(len, str, name, 0, 0);
}
static int
-isofs_dentry_cmpi(struct dentry *dentry,struct qstr *a,struct qstr *b)
+isofs_dentry_cmpi(const struct dentry *parent, const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name)
{
- return isofs_dentry_cmpi_common(dentry, a, b, 0);
+ return isofs_dentry_cmp_common(len, str, name, 0, 1);
}
#ifdef CONFIG_JOLIET
static int
-isofs_hash_ms(struct dentry *dentry, struct qstr *qstr)
+isofs_hash_ms(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *qstr)
{
return isofs_hash_common(dentry, qstr, 1);
}
static int
-isofs_hashi_ms(struct dentry *dentry, struct qstr *qstr)
+isofs_hashi_ms(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *qstr)
{
return isofs_hashi_common(dentry, qstr, 1);
}
static int
-isofs_dentry_cmp_ms(struct dentry *dentry,struct qstr *a,struct qstr *b)
+isofs_dentry_cmp_ms(const struct dentry *parent, const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name)
{
- return isofs_dentry_cmp_common(dentry, a, b, 1);
+ return isofs_dentry_cmp_common(len, str, name, 1, 0);
}
static int
-isofs_dentry_cmpi_ms(struct dentry *dentry,struct qstr *a,struct qstr *b)
+isofs_dentry_cmpi_ms(const struct dentry *parent, const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name)
{
- return isofs_dentry_cmpi_common(dentry, a, b, 1);
+ return isofs_dentry_cmp_common(len, str, name, 1, 1);
}
#endif
table += 2;
if (opt.check == 'r')
table++;
- s->s_root->d_op = &isofs_dentry_ops[table];
+ d_set_d_op(s->s_root, &isofs_dentry_ops[table]);
kfree(opt.iocharset);
qstr.name = compare;
qstr.len = dlen;
- return dentry->d_op->d_compare(dentry, &dentry->d_name, &qstr);
+ return dentry->d_op->d_compare(NULL, NULL, NULL, NULL,
+ dentry->d_name.len, dentry->d_name.name, &qstr);
}
/*
struct inode *inode;
struct page *page;
- dentry->d_op = dir->i_sb->s_root->d_op;
+ d_set_d_op(dentry, dir->i_sb->s_root->d_op);
page = alloc_page(GFP_USER);
if (!page)
return rc;
}
-int jffs2_check_acl(struct inode *inode, int mask)
+int jffs2_check_acl(struct inode *inode, int mask, unsigned int flags)
{
struct posix_acl *acl;
int rc;
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
+
acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
if (IS_ERR(acl))
return PTR_ERR(acl);
#ifdef CONFIG_JFFS2_FS_POSIX_ACL
-extern int jffs2_check_acl(struct inode *, int);
+extern int jffs2_check_acl(struct inode *, int, unsigned int);
extern int jffs2_acl_chmod(struct inode *);
extern int jffs2_init_acl_pre(struct inode *, struct inode *, int *);
extern int jffs2_init_acl_post(struct inode *);
return &f->vfs_inode;
}
-static void jffs2_destroy_inode(struct inode *inode)
+static void jffs2_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode));
}
+static void jffs2_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, jffs2_i_callback);
+}
+
static void jffs2_i_init_once(void *foo)
{
struct jffs2_inode_info *f = foo;
return rc;
}
-int jfs_check_acl(struct inode *inode, int mask)
+int jfs_check_acl(struct inode *inode, int mask, unsigned int flags)
{
- struct posix_acl *acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
+ struct posix_acl *acl;
+
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
+ acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
if (IS_ERR(acl))
return PTR_ERR(acl);
if (acl) {
#ifdef CONFIG_JFS_POSIX_ACL
-int jfs_check_acl(struct inode *, int);
+int jfs_check_acl(struct inode *, int, unsigned int flags);
int jfs_init_acl(tid_t, struct inode *, struct inode *);
int jfs_acl_chmod(struct inode *inode);
*/
#include <linux/fs.h>
+#include <linux/namei.h>
#include <linux/ctype.h>
#include <linux/quotaops.h>
#include <linux/exportfs.h>
jfs_info("jfs_lookup: name = %s", name);
if (JFS_SBI(dip->i_sb)->mntflag & JFS_OS2)
- dentry->d_op = &jfs_ci_dentry_operations;
+ d_set_d_op(dentry, &jfs_ci_dentry_operations);
if ((name[0] == '.') && (len == 1))
inum = dip->i_ino;
dentry = d_splice_alias(ip, dentry);
if (dentry && (JFS_SBI(dip->i_sb)->mntflag & JFS_OS2))
- dentry->d_op = &jfs_ci_dentry_operations;
+ d_set_d_op(dentry, &jfs_ci_dentry_operations);
return dentry;
}
.llseek = generic_file_llseek,
};
-static int jfs_ci_hash(struct dentry *dir, struct qstr *this)
+static int jfs_ci_hash(const struct dentry *dir, const struct inode *inode,
+ struct qstr *this)
{
unsigned long hash;
int i;
return 0;
}
-static int jfs_ci_compare(struct dentry *dir, struct qstr *a, struct qstr *b)
+static int jfs_ci_compare(const struct dentry *parent,
+ const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name)
{
int i, result = 1;
- if (a->len != b->len)
+ if (len != name->len)
goto out;
- for (i=0; i < a->len; i++) {
- if (tolower(a->name[i]) != tolower(b->name[i]))
+ for (i=0; i < len; i++) {
+ if (tolower(str[i]) != tolower(name->name[i]))
goto out;
}
result = 0;
+out:
+ return result;
+}
+static int jfs_ci_revalidate(struct dentry *dentry, struct nameidata *nd)
+{
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
/*
- * We want creates to preserve case. A negative dentry, a, that
- * has a different case than b may cause a new entry to be created
- * with the wrong case. Since we can't tell if a comes from a negative
- * dentry, we blindly replace it with b. This should be harmless if
- * a is not a negative dentry.
+ * This is not negative dentry. Always valid.
+ *
+ * Note, rename() to existing directory entry will have ->d_inode,
+ * and will use existing name which isn't specified name by user.
+ *
+ * We may be able to drop this positive dentry here. But dropping
+ * positive dentry isn't good idea. So it's unsupported like
+ * rename("filename", "FILENAME") for now.
*/
- memcpy((unsigned char *)a->name, b->name, a->len);
-out:
- return result;
+ if (dentry->d_inode)
+ return 1;
+
+ /*
+ * This may be nfsd (or something), anyway, we can't see the
+ * intent of this. So, since this can be for creation, drop it.
+ */
+ if (!nd)
+ return 0;
+
+ /*
+ * Drop the negative dentry, in order to make sure to use the
+ * case sensitive name which is specified by user if this is
+ * for creation.
+ */
+ if (!(nd->flags & (LOOKUP_CONTINUE | LOOKUP_PARENT))) {
+ if (nd->flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
+ return 0;
+ }
+ return 1;
}
const struct dentry_operations jfs_ci_dentry_operations =
{
.d_hash = jfs_ci_hash,
.d_compare = jfs_ci_compare,
+ .d_revalidate = jfs_ci_revalidate,
};
return &jfs_inode->vfs_inode;
}
+static void jfs_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ struct jfs_inode_info *ji = JFS_IP(inode);
+ INIT_LIST_HEAD(&inode->i_dentry);
+ kmem_cache_free(jfs_inode_cachep, ji);
+}
+
static void jfs_destroy_inode(struct inode *inode)
{
struct jfs_inode_info *ji = JFS_IP(inode);
ji->active_ag = -1;
}
spin_unlock_irq(&ji->ag_lock);
- kmem_cache_free(jfs_inode_cachep, ji);
+ call_rcu(&inode->i_rcu, jfs_i_callback);
}
static int jfs_statfs(struct dentry *dentry, struct kstatfs *buf)
goto out_no_root;
if (sbi->mntflag & JFS_OS2)
- sb->s_root->d_op = &jfs_ci_dentry_operations;
+ d_set_d_op(sb->s_root, &jfs_ci_dentry_operations);
/* logical blocks are represented by 40 bits in pxd_t, etc. */
sb->s_maxbytes = ((u64) sb->s_blocksize) << 40;
#include <asm/uaccess.h>
+static inline int simple_positive(struct dentry *dentry)
+{
+ return dentry->d_inode && !d_unhashed(dentry);
+}
+
int simple_getattr(struct vfsmount *mnt, struct dentry *dentry,
struct kstat *stat)
{
* Retaining negative dentries for an in-memory filesystem just wastes
* memory and lookup time: arrange for them to be deleted immediately.
*/
-static int simple_delete_dentry(struct dentry *dentry)
+static int simple_delete_dentry(const struct dentry *dentry)
{
return 1;
}
if (dentry->d_name.len > NAME_MAX)
return ERR_PTR(-ENAMETOOLONG);
- dentry->d_op = &simple_dentry_operations;
+ d_set_d_op(dentry, &simple_dentry_operations);
d_add(dentry, NULL);
return NULL;
}
loff_t dcache_dir_lseek(struct file *file, loff_t offset, int origin)
{
- mutex_lock(&file->f_path.dentry->d_inode->i_mutex);
+ struct dentry *dentry = file->f_path.dentry;
+ mutex_lock(&dentry->d_inode->i_mutex);
switch (origin) {
case 1:
offset += file->f_pos;
if (offset >= 0)
break;
default:
- mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
+ mutex_unlock(&dentry->d_inode->i_mutex);
return -EINVAL;
}
if (offset != file->f_pos) {
struct dentry *cursor = file->private_data;
loff_t n = file->f_pos - 2;
- spin_lock(&dcache_lock);
+ spin_lock(&dentry->d_lock);
+ /* d_lock not required for cursor */
list_del(&cursor->d_u.d_child);
- p = file->f_path.dentry->d_subdirs.next;
- while (n && p != &file->f_path.dentry->d_subdirs) {
+ p = dentry->d_subdirs.next;
+ while (n && p != &dentry->d_subdirs) {
struct dentry *next;
next = list_entry(p, struct dentry, d_u.d_child);
- if (!d_unhashed(next) && next->d_inode)
+ spin_lock_nested(&next->d_lock, DENTRY_D_LOCK_NESTED);
+ if (simple_positive(next))
n--;
+ spin_unlock(&next->d_lock);
p = p->next;
}
list_add_tail(&cursor->d_u.d_child, p);
- spin_unlock(&dcache_lock);
+ spin_unlock(&dentry->d_lock);
}
}
- mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
+ mutex_unlock(&dentry->d_inode->i_mutex);
return offset;
}
i++;
/* fallthrough */
default:
- spin_lock(&dcache_lock);
+ spin_lock(&dentry->d_lock);
if (filp->f_pos == 2)
list_move(q, &dentry->d_subdirs);
for (p=q->next; p != &dentry->d_subdirs; p=p->next) {
struct dentry *next;
next = list_entry(p, struct dentry, d_u.d_child);
- if (d_unhashed(next) || !next->d_inode)
+ spin_lock_nested(&next->d_lock, DENTRY_D_LOCK_NESTED);
+ if (!simple_positive(next)) {
+ spin_unlock(&next->d_lock);
continue;
+ }
- spin_unlock(&dcache_lock);
+ spin_unlock(&next->d_lock);
+ spin_unlock(&dentry->d_lock);
if (filldir(dirent, next->d_name.name,
next->d_name.len, filp->f_pos,
next->d_inode->i_ino,
dt_type(next->d_inode)) < 0)
return 0;
- spin_lock(&dcache_lock);
+ spin_lock(&dentry->d_lock);
+ spin_lock_nested(&next->d_lock, DENTRY_D_LOCK_NESTED);
/* next is still alive */
list_move(q, p);
+ spin_unlock(&next->d_lock);
p = q;
filp->f_pos++;
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&dentry->d_lock);
}
return 0;
}
return 0;
}
-static inline int simple_positive(struct dentry *dentry)
-{
- return dentry->d_inode && !d_unhashed(dentry);
-}
-
int simple_empty(struct dentry *dentry)
{
struct dentry *child;
int ret = 0;
- spin_lock(&dcache_lock);
- list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child)
- if (simple_positive(child))
+ spin_lock(&dentry->d_lock);
+ list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child) {
+ spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED);
+ if (simple_positive(child)) {
+ spin_unlock(&child->d_lock);
goto out;
+ }
+ spin_unlock(&child->d_lock);
+ }
ret = 1;
out:
- spin_unlock(&dcache_lock);
+ spin_unlock(&dentry->d_lock);
return ret;
}
if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0))
goto out;
if ((arg == F_WRLCK)
- && ((atomic_read(&dentry->d_count) > 1)
+ && ((dentry->d_count > 1)
|| (atomic_read(&inode->i_count) > 1)))
goto out;
}
return __logfs_create(dir, dentry, inode, target, destlen);
}
-static int logfs_permission(struct inode *inode, int mask)
+static int logfs_permission(struct inode *inode, int mask, unsigned int flags)
{
- return generic_permission(inode, mask, NULL);
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
+ return generic_permission(inode, mask, flags, NULL);
}
static int logfs_link(struct dentry *old_dentry, struct inode *dir,
return __logfs_iget(sb, ino);
}
+static void logfs_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
+ kmem_cache_free(logfs_inode_cache, logfs_inode(inode));
+}
+
static void __logfs_destroy_inode(struct inode *inode)
{
struct logfs_inode *li = logfs_inode(inode);
BUG_ON(li->li_block);
list_del(&li->li_freeing_list);
- kmem_cache_free(logfs_inode_cache, li);
+ call_rcu(&inode->i_rcu, logfs_i_callback);
}
static void logfs_destroy_inode(struct inode *inode)
return &ei->vfs_inode;
}
-static void minix_destroy_inode(struct inode *inode)
+static void minix_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(minix_inode_cachep, minix_i(inode));
}
+static void minix_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, minix_i_callback);
+}
+
static void init_once(void *foo)
{
struct minix_inode_info *ei = (struct minix_inode_info *) foo;
struct inode * inode = NULL;
ino_t ino;
- dentry->d_op = dir->i_sb->s_root->d_op;
+ d_set_d_op(dentry, dir->i_sb->s_root->d_op);
if (dentry->d_name.len > minix_sb(dir->i_sb)->s_namelen)
return ERR_PTR(-ENAMETOOLONG);
/*
* This does basic POSIX ACL permission checking
*/
-static int acl_permission_check(struct inode *inode, int mask,
- int (*check_acl)(struct inode *inode, int mask))
+static int acl_permission_check(struct inode *inode, int mask, unsigned int flags,
+ int (*check_acl)(struct inode *inode, int mask, unsigned int flags))
{
umode_t mode = inode->i_mode;
mode >>= 6;
else {
if (IS_POSIXACL(inode) && (mode & S_IRWXG) && check_acl) {
- int error = check_acl(inode, mask);
+ int error = check_acl(inode, mask, flags);
if (error != -EAGAIN)
return error;
}
}
/**
- * generic_permission - check for access rights on a Posix-like filesystem
+ * generic_permission - check for access rights on a Posix-like filesystem
* @inode: inode to check access rights for
* @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC)
* @check_acl: optional callback to check for Posix ACLs
+ * @flags IPERM_FLAG_ flags.
*
* Used to check for read/write/execute permissions on a file.
* We use "fsuid" for this, letting us set arbitrary permissions
* for filesystem access without changing the "normal" uids which
- * are used for other things..
+ * are used for other things.
+ *
+ * generic_permission is rcu-walk aware. It returns -ECHILD in case an rcu-walk
+ * request cannot be satisfied (eg. requires blocking or too much complexity).
+ * It would then be called again in ref-walk mode.
*/
-int generic_permission(struct inode *inode, int mask,
- int (*check_acl)(struct inode *inode, int mask))
+int generic_permission(struct inode *inode, int mask, unsigned int flags,
+ int (*check_acl)(struct inode *inode, int mask, unsigned int flags))
{
int ret;
/*
* Do the basic POSIX ACL permission checks.
*/
- ret = acl_permission_check(inode, mask, check_acl);
+ ret = acl_permission_check(inode, mask, flags, check_acl);
if (ret != -EACCES)
return ret;
}
if (inode->i_op->permission)
- retval = inode->i_op->permission(inode, mask);
+ retval = inode->i_op->permission(inode, mask, 0);
else
- retval = generic_permission(inode, mask, inode->i_op->check_acl);
+ retval = generic_permission(inode, mask, 0,
+ inode->i_op->check_acl);
if (retval)
return retval;
EXPORT_SYMBOL(path_get);
/**
+ * path_get_long - get a long reference to a path
+ * @path: path to get the reference to
+ *
+ * Given a path increment the reference count to the dentry and the vfsmount.
+ */
+void path_get_long(struct path *path)
+{
+ mntget_long(path->mnt);
+ dget(path->dentry);
+}
+
+/**
* path_put - put a reference to a path
* @path: path to put the reference to
*
EXPORT_SYMBOL(path_put);
/**
+ * path_put_long - put a long reference to a path
+ * @path: path to put the reference to
+ *
+ * Given a path decrement the reference count to the dentry and the vfsmount.
+ */
+void path_put_long(struct path *path)
+{
+ dput(path->dentry);
+ mntput_long(path->mnt);
+}
+
+/**
+ * nameidata_drop_rcu - drop this nameidata out of rcu-walk
+ * @nd: nameidata pathwalk data to drop
+ * @Returns: 0 on success, -ECHLID on failure
+ *
+ * Path walking has 2 modes, rcu-walk and ref-walk (see
+ * Documentation/filesystems/path-lookup.txt). __drop_rcu* functions attempt
+ * to drop out of rcu-walk mode and take normal reference counts on dentries
+ * and vfsmounts to transition to rcu-walk mode. __drop_rcu* functions take
+ * refcounts at the last known good point before rcu-walk got stuck, so
+ * ref-walk may continue from there. If this is not successful (eg. a seqcount
+ * has changed), then failure is returned and path walk restarts from the
+ * beginning in ref-walk mode.
+ *
+ * nameidata_drop_rcu attempts to drop the current nd->path and nd->root into
+ * ref-walk. Must be called from rcu-walk context.
+ */
+static int nameidata_drop_rcu(struct nameidata *nd)
+{
+ struct fs_struct *fs = current->fs;
+ struct dentry *dentry = nd->path.dentry;
+
+ BUG_ON(!(nd->flags & LOOKUP_RCU));
+ if (nd->root.mnt) {
+ spin_lock(&fs->lock);
+ if (nd->root.mnt != fs->root.mnt ||
+ nd->root.dentry != fs->root.dentry)
+ goto err_root;
+ }
+ spin_lock(&dentry->d_lock);
+ if (!__d_rcu_to_refcount(dentry, nd->seq))
+ goto err;
+ BUG_ON(nd->inode != dentry->d_inode);
+ spin_unlock(&dentry->d_lock);
+ if (nd->root.mnt) {
+ path_get(&nd->root);
+ spin_unlock(&fs->lock);
+ }
+ mntget(nd->path.mnt);
+
+ rcu_read_unlock();
+ br_read_unlock(vfsmount_lock);
+ nd->flags &= ~LOOKUP_RCU;
+ return 0;
+err:
+ spin_unlock(&dentry->d_lock);
+err_root:
+ if (nd->root.mnt)
+ spin_unlock(&fs->lock);
+ return -ECHILD;
+}
+
+/* Try to drop out of rcu-walk mode if we were in it, otherwise do nothing. */
+static inline int nameidata_drop_rcu_maybe(struct nameidata *nd)
+{
+ if (nd->flags & LOOKUP_RCU)
+ return nameidata_drop_rcu(nd);
+ return 0;
+}
+
+/**
+ * nameidata_dentry_drop_rcu - drop nameidata and dentry out of rcu-walk
+ * @nd: nameidata pathwalk data to drop
+ * @dentry: dentry to drop
+ * @Returns: 0 on success, -ECHLID on failure
+ *
+ * nameidata_dentry_drop_rcu attempts to drop the current nd->path and nd->root,
+ * and dentry into ref-walk. @dentry must be a path found by a do_lookup call on
+ * @nd. Must be called from rcu-walk context.
+ */
+static int nameidata_dentry_drop_rcu(struct nameidata *nd, struct dentry *dentry)
+{
+ struct fs_struct *fs = current->fs;
+ struct dentry *parent = nd->path.dentry;
+
+ BUG_ON(!(nd->flags & LOOKUP_RCU));
+ if (nd->root.mnt) {
+ spin_lock(&fs->lock);
+ if (nd->root.mnt != fs->root.mnt ||
+ nd->root.dentry != fs->root.dentry)
+ goto err_root;
+ }
+ spin_lock(&parent->d_lock);
+ spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
+ if (!__d_rcu_to_refcount(dentry, nd->seq))
+ goto err;
+ /*
+ * If the sequence check on the child dentry passed, then the child has
+ * not been removed from its parent. This means the parent dentry must
+ * be valid and able to take a reference at this point.
+ */
+ BUG_ON(!IS_ROOT(dentry) && dentry->d_parent != parent);
+ BUG_ON(!parent->d_count);
+ parent->d_count++;
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&parent->d_lock);
+ if (nd->root.mnt) {
+ path_get(&nd->root);
+ spin_unlock(&fs->lock);
+ }
+ mntget(nd->path.mnt);
+
+ rcu_read_unlock();
+ br_read_unlock(vfsmount_lock);
+ nd->flags &= ~LOOKUP_RCU;
+ return 0;
+err:
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&parent->d_lock);
+err_root:
+ if (nd->root.mnt)
+ spin_unlock(&fs->lock);
+ return -ECHILD;
+}
+
+/* Try to drop out of rcu-walk mode if we were in it, otherwise do nothing. */
+static inline int nameidata_dentry_drop_rcu_maybe(struct nameidata *nd, struct dentry *dentry)
+{
+ if (nd->flags & LOOKUP_RCU)
+ return nameidata_dentry_drop_rcu(nd, dentry);
+ return 0;
+}
+
+/**
+ * nameidata_drop_rcu_last - drop nameidata ending path walk out of rcu-walk
+ * @nd: nameidata pathwalk data to drop
+ * @Returns: 0 on success, -ECHLID on failure
+ *
+ * nameidata_drop_rcu_last attempts to drop the current nd->path into ref-walk.
+ * nd->path should be the final element of the lookup, so nd->root is discarded.
+ * Must be called from rcu-walk context.
+ */
+static int nameidata_drop_rcu_last(struct nameidata *nd)
+{
+ struct dentry *dentry = nd->path.dentry;
+
+ BUG_ON(!(nd->flags & LOOKUP_RCU));
+ nd->flags &= ~LOOKUP_RCU;
+ nd->root.mnt = NULL;
+ spin_lock(&dentry->d_lock);
+ if (!__d_rcu_to_refcount(dentry, nd->seq))
+ goto err_unlock;
+ BUG_ON(nd->inode != dentry->d_inode);
+ spin_unlock(&dentry->d_lock);
+
+ mntget(nd->path.mnt);
+
+ rcu_read_unlock();
+ br_read_unlock(vfsmount_lock);
+
+ return 0;
+
+err_unlock:
+ spin_unlock(&dentry->d_lock);
+ rcu_read_unlock();
+ br_read_unlock(vfsmount_lock);
+ return -ECHILD;
+}
+
+/* Try to drop out of rcu-walk mode if we were in it, otherwise do nothing. */
+static inline int nameidata_drop_rcu_last_maybe(struct nameidata *nd)
+{
+ if (likely(nd->flags & LOOKUP_RCU))
+ return nameidata_drop_rcu_last(nd);
+ return 0;
+}
+
+/**
* release_open_intent - free up open intent resources
* @nd: pointer to nameidata
*/
fput(nd->intent.open.file);
}
+static int d_revalidate(struct dentry *dentry, struct nameidata *nd)
+{
+ int status;
+
+ status = dentry->d_op->d_revalidate(dentry, nd);
+ if (status == -ECHILD) {
+ if (nameidata_dentry_drop_rcu(nd, dentry))
+ return status;
+ status = dentry->d_op->d_revalidate(dentry, nd);
+ }
+
+ return status;
+}
+
static inline struct dentry *
do_revalidate(struct dentry *dentry, struct nameidata *nd)
{
- int status = dentry->d_op->d_revalidate(dentry, nd);
+ int status;
+
+ status = d_revalidate(dentry, nd);
if (unlikely(status <= 0)) {
/*
* The dentry failed validation.
* the dentry otherwise d_revalidate is asking us
* to return a fail status.
*/
- if (!status) {
+ if (status < 0) {
+ /* If we're in rcu-walk, we don't have a ref */
+ if (!(nd->flags & LOOKUP_RCU))
+ dput(dentry);
+ dentry = ERR_PTR(status);
+
+ } else {
+ /* Don't d_invalidate in rcu-walk mode */
+ if (nameidata_dentry_drop_rcu_maybe(nd, dentry))
+ return ERR_PTR(-ECHILD);
if (!d_invalidate(dentry)) {
dput(dentry);
dentry = NULL;
}
- } else {
- dput(dentry);
- dentry = ERR_PTR(status);
}
}
return dentry;
}
+static inline int need_reval_dot(struct dentry *dentry)
+{
+ if (likely(!(dentry->d_flags & DCACHE_OP_REVALIDATE)))
+ return 0;
+
+ if (likely(!(dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT)))
+ return 0;
+
+ return 1;
+}
+
/*
* force_reval_path - force revalidation of a dentry
*
/*
* only check on filesystems where it's possible for the dentry to
- * become stale. It's assumed that if this flag is set then the
- * d_revalidate op will also be defined.
+ * become stale.
*/
- if (!(dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT))
+ if (!need_reval_dot(dentry))
return 0;
- status = dentry->d_op->d_revalidate(dentry, nd);
+ status = d_revalidate(dentry, nd);
if (status > 0)
return 0;
* short-cut DAC fails, then call ->permission() to do more
* complete permission check.
*/
-static int exec_permission(struct inode *inode)
+static inline int exec_permission(struct inode *inode, unsigned int flags)
{
int ret;
if (inode->i_op->permission) {
- ret = inode->i_op->permission(inode, MAY_EXEC);
- if (!ret)
- goto ok;
- return ret;
+ ret = inode->i_op->permission(inode, MAY_EXEC, flags);
+ } else {
+ ret = acl_permission_check(inode, MAY_EXEC, flags,
+ inode->i_op->check_acl);
}
- ret = acl_permission_check(inode, MAY_EXEC, inode->i_op->check_acl);
- if (!ret)
+ if (likely(!ret))
goto ok;
+ if (ret == -ECHILD)
+ return ret;
if (capable(CAP_DAC_OVERRIDE) || capable(CAP_DAC_READ_SEARCH))
goto ok;
return ret;
ok:
- return security_inode_permission(inode, MAY_EXEC);
+ return security_inode_exec_permission(inode, flags);
}
static __always_inline void set_root(struct nameidata *nd)
static int link_path_walk(const char *, struct nameidata *);
+static __always_inline void set_root_rcu(struct nameidata *nd)
+{
+ if (!nd->root.mnt) {
+ struct fs_struct *fs = current->fs;
+ unsigned seq;
+
+ do {
+ seq = read_seqcount_begin(&fs->seq);
+ nd->root = fs->root;
+ } while (read_seqcount_retry(&fs->seq, seq));
+ }
+}
+
static __always_inline int __vfs_follow_link(struct nameidata *nd, const char *link)
{
+ int ret;
+
if (IS_ERR(link))
goto fail;
nd->path = nd->root;
path_get(&nd->root);
}
+ nd->inode = nd->path.dentry->d_inode;
- return link_path_walk(link, nd);
+ ret = link_path_walk(link, nd);
+ return ret;
fail:
path_put(&nd->path);
return PTR_ERR(link);
static inline void path_to_nameidata(struct path *path, struct nameidata *nd)
{
- dput(nd->path.dentry);
- if (nd->path.mnt != path->mnt) {
- mntput(nd->path.mnt);
- nd->path.mnt = path->mnt;
+ if (!(nd->flags & LOOKUP_RCU)) {
+ dput(nd->path.dentry);
+ if (nd->path.mnt != path->mnt)
+ mntput(nd->path.mnt);
}
+ nd->path.mnt = path->mnt;
nd->path.dentry = path->dentry;
}
if (path->mnt != nd->path.mnt) {
path_to_nameidata(path, nd);
+ nd->inode = nd->path.dentry->d_inode;
dget(dentry);
}
mntget(path->mnt);
+
nd->last_type = LAST_BIND;
*p = dentry->d_inode->i_op->follow_link(dentry, nd);
error = PTR_ERR(*p);
return err;
}
+static int follow_up_rcu(struct path *path)
+{
+ struct vfsmount *parent;
+ struct dentry *mountpoint;
+
+ parent = path->mnt->mnt_parent;
+ if (parent == path->mnt)
+ return 0;
+ mountpoint = path->mnt->mnt_mountpoint;
+ path->dentry = mountpoint;
+ path->mnt = parent;
+ return 1;
+}
+
int follow_up(struct path *path)
{
struct vfsmount *parent;
return 1;
}
-/* no need for dcache_lock, as serialization is taken care in
- * namespace.c
+/*
+ * serialization is taken care of in namespace.c
*/
+static void __follow_mount_rcu(struct nameidata *nd, struct path *path,
+ struct inode **inode)
+{
+ while (d_mountpoint(path->dentry)) {
+ struct vfsmount *mounted;
+ mounted = __lookup_mnt(path->mnt, path->dentry, 1);
+ if (!mounted)
+ return;
+ path->mnt = mounted;
+ path->dentry = mounted->mnt_root;
+ nd->seq = read_seqcount_begin(&path->dentry->d_seq);
+ *inode = path->dentry->d_inode;
+ }
+}
+
static int __follow_mount(struct path *path)
{
int res = 0;
}
}
-/* no need for dcache_lock, as serialization is taken care in
- * namespace.c
- */
int follow_down(struct path *path)
{
struct vfsmount *mounted;
return 0;
}
-static __always_inline void follow_dotdot(struct nameidata *nd)
+static int follow_dotdot_rcu(struct nameidata *nd)
+{
+ struct inode *inode = nd->inode;
+
+ set_root_rcu(nd);
+
+ while(1) {
+ if (nd->path.dentry == nd->root.dentry &&
+ nd->path.mnt == nd->root.mnt) {
+ break;
+ }
+ if (nd->path.dentry != nd->path.mnt->mnt_root) {
+ struct dentry *old = nd->path.dentry;
+ struct dentry *parent = old->d_parent;
+ unsigned seq;
+
+ seq = read_seqcount_begin(&parent->d_seq);
+ if (read_seqcount_retry(&old->d_seq, nd->seq))
+ return -ECHILD;
+ inode = parent->d_inode;
+ nd->path.dentry = parent;
+ nd->seq = seq;
+ break;
+ }
+ if (!follow_up_rcu(&nd->path))
+ break;
+ nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
+ inode = nd->path.dentry->d_inode;
+ }
+ __follow_mount_rcu(nd, &nd->path, &inode);
+ nd->inode = inode;
+
+ return 0;
+}
+
+static void follow_dotdot(struct nameidata *nd)
{
set_root(nd);
break;
}
follow_mount(&nd->path);
+ nd->inode = nd->path.dentry->d_inode;
}
/*
* It _is_ time-critical.
*/
static int do_lookup(struct nameidata *nd, struct qstr *name,
- struct path *path)
+ struct path *path, struct inode **inode)
{
struct vfsmount *mnt = nd->path.mnt;
- struct dentry *dentry, *parent;
+ struct dentry *dentry, *parent = nd->path.dentry;
struct inode *dir;
/*
* See if the low-level filesystem might want
* to use its own hash..
*/
- if (nd->path.dentry->d_op && nd->path.dentry->d_op->d_hash) {
- int err = nd->path.dentry->d_op->d_hash(nd->path.dentry, name);
+ if (unlikely(parent->d_flags & DCACHE_OP_HASH)) {
+ int err = parent->d_op->d_hash(parent, nd->inode, name);
if (err < 0)
return err;
}
* of a false negative due to a concurrent rename, we're going to
* do the non-racy lookup, below.
*/
- dentry = __d_lookup(nd->path.dentry, name);
- if (!dentry)
- goto need_lookup;
+ if (nd->flags & LOOKUP_RCU) {
+ unsigned seq;
+
+ *inode = nd->inode;
+ dentry = __d_lookup_rcu(parent, name, &seq, inode);
+ if (!dentry) {
+ if (nameidata_drop_rcu(nd))
+ return -ECHILD;
+ goto need_lookup;
+ }
+ /* Memory barrier in read_seqcount_begin of child is enough */
+ if (__read_seqcount_retry(&parent->d_seq, nd->seq))
+ return -ECHILD;
+
+ nd->seq = seq;
+ if (dentry->d_flags & DCACHE_OP_REVALIDATE)
+ goto need_revalidate;
+ path->mnt = mnt;
+ path->dentry = dentry;
+ __follow_mount_rcu(nd, path, inode);
+ } else {
+ dentry = __d_lookup(parent, name);
+ if (!dentry)
+ goto need_lookup;
found:
- if (dentry->d_op && dentry->d_op->d_revalidate)
- goto need_revalidate;
+ if (dentry->d_flags & DCACHE_OP_REVALIDATE)
+ goto need_revalidate;
done:
- path->mnt = mnt;
- path->dentry = dentry;
- __follow_mount(path);
+ path->mnt = mnt;
+ path->dentry = dentry;
+ __follow_mount(path);
+ *inode = path->dentry->d_inode;
+ }
return 0;
need_lookup:
- parent = nd->path.dentry;
dir = parent->d_inode;
+ BUG_ON(nd->inode != dir);
mutex_lock(&dir->i_mutex);
/*
static int link_path_walk(const char *name, struct nameidata *nd)
{
struct path next;
- struct inode *inode;
int err;
unsigned int lookup_flags = nd->flags;
if (!*name)
goto return_reval;
- inode = nd->path.dentry->d_inode;
if (nd->depth)
lookup_flags = LOOKUP_FOLLOW | (nd->flags & LOOKUP_CONTINUE);
/* At this point we know we have a real path component. */
for(;;) {
+ struct inode *inode;
unsigned long hash;
struct qstr this;
unsigned int c;
nd->flags |= LOOKUP_CONTINUE;
- err = exec_permission(inode);
+ if (nd->flags & LOOKUP_RCU) {
+ err = exec_permission(nd->inode, IPERM_FLAG_RCU);
+ if (err == -ECHILD) {
+ if (nameidata_drop_rcu(nd))
+ return -ECHILD;
+ goto exec_again;
+ }
+ } else {
+exec_again:
+ err = exec_permission(nd->inode, 0);
+ }
if (err)
break;
if (this.name[0] == '.') switch (this.len) {
default:
break;
- case 2:
+ case 2:
if (this.name[1] != '.')
break;
- follow_dotdot(nd);
- inode = nd->path.dentry->d_inode;
+ if (nd->flags & LOOKUP_RCU) {
+ if (follow_dotdot_rcu(nd))
+ return -ECHILD;
+ } else
+ follow_dotdot(nd);
/* fallthrough */
case 1:
continue;
}
/* This does the actual lookups.. */
- err = do_lookup(nd, &this, &next);
+ err = do_lookup(nd, &this, &next, &inode);
if (err)
break;
-
err = -ENOENT;
- inode = next.dentry->d_inode;
if (!inode)
goto out_dput;
if (inode->i_op->follow_link) {
+ /* We commonly drop rcu-walk here */
+ if (nameidata_dentry_drop_rcu_maybe(nd, next.dentry))
+ return -ECHILD;
+ BUG_ON(inode != next.dentry->d_inode);
err = do_follow_link(&next, nd);
if (err)
goto return_err;
+ nd->inode = nd->path.dentry->d_inode;
err = -ENOENT;
- inode = nd->path.dentry->d_inode;
- if (!inode)
+ if (!nd->inode)
break;
- } else
+ } else {
path_to_nameidata(&next, nd);
+ nd->inode = inode;
+ }
err = -ENOTDIR;
- if (!inode->i_op->lookup)
+ if (!nd->inode->i_op->lookup)
break;
continue;
/* here ends the main loop */
if (this.name[0] == '.') switch (this.len) {
default:
break;
- case 2:
+ case 2:
if (this.name[1] != '.')
break;
- follow_dotdot(nd);
- inode = nd->path.dentry->d_inode;
+ if (nd->flags & LOOKUP_RCU) {
+ if (follow_dotdot_rcu(nd))
+ return -ECHILD;
+ } else
+ follow_dotdot(nd);
/* fallthrough */
case 1:
goto return_reval;
}
- err = do_lookup(nd, &this, &next);
+ err = do_lookup(nd, &this, &next, &inode);
if (err)
break;
- inode = next.dentry->d_inode;
if (follow_on_final(inode, lookup_flags)) {
+ if (nameidata_dentry_drop_rcu_maybe(nd, next.dentry))
+ return -ECHILD;
+ BUG_ON(inode != next.dentry->d_inode);
err = do_follow_link(&next, nd);
if (err)
goto return_err;
- inode = nd->path.dentry->d_inode;
- } else
+ nd->inode = nd->path.dentry->d_inode;
+ } else {
path_to_nameidata(&next, nd);
+ nd->inode = inode;
+ }
err = -ENOENT;
- if (!inode)
+ if (!nd->inode)
break;
if (lookup_flags & LOOKUP_DIRECTORY) {
err = -ENOTDIR;
- if (!inode->i_op->lookup)
+ if (!nd->inode->i_op->lookup)
break;
}
goto return_base;
* We bypassed the ordinary revalidation routines.
* We may need to check the cached dentry for staleness.
*/
- if (nd->path.dentry && nd->path.dentry->d_sb &&
- (nd->path.dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT)) {
- err = -ESTALE;
+ if (need_reval_dot(nd->path.dentry)) {
/* Note: we do not d_invalidate() */
- if (!nd->path.dentry->d_op->d_revalidate(
- nd->path.dentry, nd))
+ err = d_revalidate(nd->path.dentry, nd);
+ if (!err)
+ err = -ESTALE;
+ if (err < 0)
break;
}
return_base:
+ if (nameidata_drop_rcu_last_maybe(nd))
+ return -ECHILD;
return 0;
out_dput:
- path_put_conditional(&next, nd);
+ if (!(nd->flags & LOOKUP_RCU))
+ path_put_conditional(&next, nd);
break;
}
- path_put(&nd->path);
+ if (!(nd->flags & LOOKUP_RCU))
+ path_put(&nd->path);
return_err:
return err;
}
+static inline int path_walk_rcu(const char *name, struct nameidata *nd)
+{
+ current->total_link_count = 0;
+
+ return link_path_walk(name, nd);
+}
+
+static inline int path_walk_simple(const char *name, struct nameidata *nd)
+{
+ current->total_link_count = 0;
+
+ return link_path_walk(name, nd);
+}
+
static int path_walk(const char *name, struct nameidata *nd)
{
struct path save = nd->path;
return result;
}
+static void path_finish_rcu(struct nameidata *nd)
+{
+ if (nd->flags & LOOKUP_RCU) {
+ /* RCU dangling. Cancel it. */
+ nd->flags &= ~LOOKUP_RCU;
+ nd->root.mnt = NULL;
+ rcu_read_unlock();
+ br_read_unlock(vfsmount_lock);
+ }
+ if (nd->file)
+ fput(nd->file);
+}
+
+static int path_init_rcu(int dfd, const char *name, unsigned int flags, struct nameidata *nd)
+{
+ int retval = 0;
+ int fput_needed;
+ struct file *file;
+
+ nd->last_type = LAST_ROOT; /* if there are only slashes... */
+ nd->flags = flags | LOOKUP_RCU;
+ nd->depth = 0;
+ nd->root.mnt = NULL;
+ nd->file = NULL;
+
+ if (*name=='/') {
+ struct fs_struct *fs = current->fs;
+ unsigned seq;
+
+ br_read_lock(vfsmount_lock);
+ rcu_read_lock();
+
+ do {
+ seq = read_seqcount_begin(&fs->seq);
+ nd->root = fs->root;
+ nd->path = nd->root;
+ nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq);
+ } while (read_seqcount_retry(&fs->seq, seq));
+
+ } else if (dfd == AT_FDCWD) {
+ struct fs_struct *fs = current->fs;
+ unsigned seq;
+
+ br_read_lock(vfsmount_lock);
+ rcu_read_lock();
+
+ do {
+ seq = read_seqcount_begin(&fs->seq);
+ nd->path = fs->pwd;
+ nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq);
+ } while (read_seqcount_retry(&fs->seq, seq));
+
+ } else {
+ struct dentry *dentry;
+
+ file = fget_light(dfd, &fput_needed);
+ retval = -EBADF;
+ if (!file)
+ goto out_fail;
+
+ dentry = file->f_path.dentry;
+
+ retval = -ENOTDIR;
+ if (!S_ISDIR(dentry->d_inode->i_mode))
+ goto fput_fail;
+
+ retval = file_permission(file, MAY_EXEC);
+ if (retval)
+ goto fput_fail;
+
+ nd->path = file->f_path;
+ if (fput_needed)
+ nd->file = file;
+
+ nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq);
+ br_read_lock(vfsmount_lock);
+ rcu_read_lock();
+ }
+ nd->inode = nd->path.dentry->d_inode;
+ return 0;
+
+fput_fail:
+ fput_light(file, fput_needed);
+out_fail:
+ return retval;
+}
+
static int path_init(int dfd, const char *name, unsigned int flags, struct nameidata *nd)
{
int retval = 0;
fput_light(file, fput_needed);
}
+ nd->inode = nd->path.dentry->d_inode;
return 0;
fput_fail:
static int do_path_lookup(int dfd, const char *name,
unsigned int flags, struct nameidata *nd)
{
- int retval = path_init(dfd, name, flags, nd);
- if (!retval)
- retval = path_walk(name, nd);
- if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry &&
- nd->path.dentry->d_inode))
- audit_inode(name, nd->path.dentry);
+ int retval;
+
+ /*
+ * Path walking is largely split up into 2 different synchronisation
+ * schemes, rcu-walk and ref-walk (explained in
+ * Documentation/filesystems/path-lookup.txt). These share much of the
+ * path walk code, but some things particularly setup, cleanup, and
+ * following mounts are sufficiently divergent that functions are
+ * duplicated. Typically there is a function foo(), and its RCU
+ * analogue, foo_rcu().
+ *
+ * -ECHILD is the error number of choice (just to avoid clashes) that
+ * is returned if some aspect of an rcu-walk fails. Such an error must
+ * be handled by restarting a traditional ref-walk (which will always
+ * be able to complete).
+ */
+ retval = path_init_rcu(dfd, name, flags, nd);
+ if (unlikely(retval))
+ return retval;
+ retval = path_walk_rcu(name, nd);
+ path_finish_rcu(nd);
if (nd->root.mnt) {
path_put(&nd->root);
nd->root.mnt = NULL;
}
+
+ if (unlikely(retval == -ECHILD || retval == -ESTALE)) {
+ /* slower, locked walk */
+ if (retval == -ESTALE)
+ flags |= LOOKUP_REVAL;
+ retval = path_init(dfd, name, flags, nd);
+ if (unlikely(retval))
+ return retval;
+ retval = path_walk(name, nd);
+ if (nd->root.mnt) {
+ path_put(&nd->root);
+ nd->root.mnt = NULL;
+ }
+ }
+
+ if (likely(!retval)) {
+ if (unlikely(!audit_dummy_context())) {
+ if (nd->path.dentry && nd->inode)
+ audit_inode(name, nd->path.dentry);
+ }
+ }
+
return retval;
}
path_get(&nd->path);
nd->root = nd->path;
path_get(&nd->root);
+ nd->inode = nd->path.dentry->d_inode;
retval = path_walk(name, nd);
if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry &&
- nd->path.dentry->d_inode))
+ nd->inode))
audit_inode(name, nd->path.dentry);
path_put(&nd->root);
struct dentry *dentry;
int err;
- err = exec_permission(inode);
+ err = exec_permission(inode, 0);
if (err)
return ERR_PTR(err);
* See if the low-level filesystem might want
* to use its own hash..
*/
- if (base->d_op && base->d_op->d_hash) {
- err = base->d_op->d_hash(base, name);
+ if (base->d_flags & DCACHE_OP_HASH) {
+ err = base->d_op->d_hash(base, inode, name);
dentry = ERR_PTR(err);
if (err < 0)
goto out;
*/
dentry = d_lookup(base, name);
- if (dentry && dentry->d_op && dentry->d_op->d_revalidate)
+ if (dentry && (dentry->d_flags & DCACHE_OP_REVALIDATE))
dentry = do_revalidate(dentry, nd);
if (!dentry)
mutex_unlock(&dir->d_inode->i_mutex);
dput(nd->path.dentry);
nd->path.dentry = path->dentry;
+
if (error)
return error;
/* Don't check for write permission, don't truncate */
return ERR_PTR(error);
}
+/*
+ * Handle O_CREAT case for do_filp_open
+ */
static struct file *do_last(struct nameidata *nd, struct path *path,
int open_flag, int acc_mode,
int mode, const char *pathname)
follow_dotdot(nd);
dir = nd->path.dentry;
case LAST_DOT:
- if (nd->path.mnt->mnt_sb->s_type->fs_flags & FS_REVAL_DOT) {
- if (!dir->d_op->d_revalidate(dir, nd)) {
+ if (need_reval_dot(dir)) {
+ error = d_revalidate(nd->path.dentry, nd);
+ if (!error)
error = -ESTALE;
+ if (error < 0)
goto exit;
- }
}
/* fallthrough */
case LAST_ROOT:
- if (open_flag & O_CREAT)
- goto exit;
- /* fallthrough */
+ goto exit;
case LAST_BIND:
audit_inode(pathname, dir);
goto ok;
}
/* trailing slashes? */
- if (nd->last.name[nd->last.len]) {
- if (open_flag & O_CREAT)
- goto exit;
- nd->flags |= LOOKUP_DIRECTORY | LOOKUP_FOLLOW;
- }
-
- /* just plain open? */
- if (!(open_flag & O_CREAT)) {
- error = do_lookup(nd, &nd->last, path);
- if (error)
- goto exit;
- error = -ENOENT;
- if (!path->dentry->d_inode)
- goto exit_dput;
- if (path->dentry->d_inode->i_op->follow_link)
- return NULL;
- error = -ENOTDIR;
- if (nd->flags & LOOKUP_DIRECTORY) {
- if (!path->dentry->d_inode->i_op->lookup)
- goto exit_dput;
- }
- path_to_nameidata(path, nd);
- audit_inode(pathname, nd->path.dentry);
- goto ok;
- }
+ if (nd->last.name[nd->last.len])
+ goto exit;
- /* OK, it's O_CREAT */
mutex_lock(&dir->d_inode->i_mutex);
path->dentry = lookup_hash(nd);
return NULL;
path_to_nameidata(path, nd);
+ nd->inode = path->dentry->d_inode;
error = -EISDIR;
- if (S_ISDIR(path->dentry->d_inode->i_mode))
+ if (S_ISDIR(nd->inode->i_mode))
goto exit;
ok:
filp = finish_open(nd, open_flag, acc_mode);
struct path path;
int count = 0;
int flag = open_to_namei_flags(open_flag);
- int force_reval = 0;
+ int flags;
if (!(open_flag & O_CREAT))
mode = 0;
if (open_flag & O_APPEND)
acc_mode |= MAY_APPEND;
- /* find the parent */
-reval:
- error = path_init(dfd, pathname, LOOKUP_PARENT, &nd);
+ flags = LOOKUP_OPEN;
+ if (open_flag & O_CREAT) {
+ flags |= LOOKUP_CREATE;
+ if (open_flag & O_EXCL)
+ flags |= LOOKUP_EXCL;
+ }
+ if (open_flag & O_DIRECTORY)
+ flags |= LOOKUP_DIRECTORY;
+ if (!(open_flag & O_NOFOLLOW))
+ flags |= LOOKUP_FOLLOW;
+
+ filp = get_empty_filp();
+ if (!filp)
+ return ERR_PTR(-ENFILE);
+
+ filp->f_flags = open_flag;
+ nd.intent.open.file = filp;
+ nd.intent.open.flags = flag;
+ nd.intent.open.create_mode = mode;
+
+ if (open_flag & O_CREAT)
+ goto creat;
+
+ /* !O_CREAT, simple open */
+ error = do_path_lookup(dfd, pathname, flags, &nd);
+ if (unlikely(error))
+ goto out_filp;
+ error = -ELOOP;
+ if (!(nd.flags & LOOKUP_FOLLOW)) {
+ if (nd.inode->i_op->follow_link)
+ goto out_path;
+ }
+ error = -ENOTDIR;
+ if (nd.flags & LOOKUP_DIRECTORY) {
+ if (!nd.inode->i_op->lookup)
+ goto out_path;
+ }
+ audit_inode(pathname, nd.path.dentry);
+ filp = finish_open(&nd, open_flag, acc_mode);
+ return filp;
+
+creat:
+ /* OK, have to create the file. Find the parent. */
+ error = path_init_rcu(dfd, pathname,
+ LOOKUP_PARENT | (flags & LOOKUP_REVAL), &nd);
if (error)
- return ERR_PTR(error);
- if (force_reval)
- nd.flags |= LOOKUP_REVAL;
+ goto out_filp;
+ error = path_walk_rcu(pathname, &nd);
+ path_finish_rcu(&nd);
+ if (unlikely(error == -ECHILD || error == -ESTALE)) {
+ /* slower, locked walk */
+ if (error == -ESTALE) {
+reval:
+ flags |= LOOKUP_REVAL;
+ }
+ error = path_init(dfd, pathname,
+ LOOKUP_PARENT | (flags & LOOKUP_REVAL), &nd);
+ if (error)
+ goto out_filp;
- current->total_link_count = 0;
- error = link_path_walk(pathname, &nd);
- if (error) {
- filp = ERR_PTR(error);
- goto out;
+ error = path_walk_simple(pathname, &nd);
}
- if (unlikely(!audit_dummy_context()) && (open_flag & O_CREAT))
+ if (unlikely(error))
+ goto out_filp;
+ if (unlikely(!audit_dummy_context()))
audit_inode(pathname, nd.path.dentry);
/*
* We have the parent and last component.
*/
-
- error = -ENFILE;
- filp = get_empty_filp();
- if (filp == NULL)
- goto exit_parent;
- nd.intent.open.file = filp;
- filp->f_flags = open_flag;
- nd.intent.open.flags = flag;
- nd.intent.open.create_mode = mode;
- nd.flags &= ~LOOKUP_PARENT;
- nd.flags |= LOOKUP_OPEN;
- if (open_flag & O_CREAT) {
- nd.flags |= LOOKUP_CREATE;
- if (open_flag & O_EXCL)
- nd.flags |= LOOKUP_EXCL;
- }
- if (open_flag & O_DIRECTORY)
- nd.flags |= LOOKUP_DIRECTORY;
- if (!(open_flag & O_NOFOLLOW))
- nd.flags |= LOOKUP_FOLLOW;
+ nd.flags = flags;
filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname);
while (unlikely(!filp)) { /* trailing symlink */
struct path holder;
- struct inode *inode = path.dentry->d_inode;
void *cookie;
error = -ELOOP;
/* S_ISDIR part is a temporary automount kludge */
- if (!(nd.flags & LOOKUP_FOLLOW) && !S_ISDIR(inode->i_mode))
+ if (!(nd.flags & LOOKUP_FOLLOW) && !S_ISDIR(nd.inode->i_mode))
goto exit_dput;
if (count++ == 32)
goto exit_dput;
goto exit_dput;
error = __do_follow_link(&path, &nd, &cookie);
if (unlikely(error)) {
+ if (!IS_ERR(cookie) && nd.inode->i_op->put_link)
+ nd.inode->i_op->put_link(path.dentry, &nd, cookie);
/* nd.path had been dropped */
- if (!IS_ERR(cookie) && inode->i_op->put_link)
- inode->i_op->put_link(path.dentry, &nd, cookie);
- path_put(&path);
- release_open_intent(&nd);
- filp = ERR_PTR(error);
- goto out;
+ nd.path = path;
+ goto out_path;
}
holder = path;
nd.flags &= ~LOOKUP_PARENT;
filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname);
- if (inode->i_op->put_link)
- inode->i_op->put_link(holder.dentry, &nd, cookie);
+ if (nd.inode->i_op->put_link)
+ nd.inode->i_op->put_link(holder.dentry, &nd, cookie);
path_put(&holder);
}
out:
if (nd.root.mnt)
path_put(&nd.root);
- if (filp == ERR_PTR(-ESTALE) && !force_reval) {
- force_reval = 1;
+ if (filp == ERR_PTR(-ESTALE) && !(flags & LOOKUP_REVAL))
goto reval;
- }
return filp;
exit_dput:
path_put_conditional(&path, &nd);
+out_path:
+ path_put(&nd.path);
+out_filp:
if (!IS_ERR(nd.intent.open.file))
release_open_intent(&nd);
-exit_parent:
- path_put(&nd.path);
filp = ERR_PTR(error);
goto out;
}
{
dget(dentry);
shrink_dcache_parent(dentry);
- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
- if (atomic_read(&dentry->d_count) == 2)
+ if (dentry->d_count == 2)
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
}
int vfs_rmdir(struct inode *dir, struct dentry *dentry)
mnt->mnt_group_id = 0;
}
+/*
+ * vfsmount lock must be held for read
+ */
+static inline void mnt_add_count(struct vfsmount *mnt, int n)
+{
+#ifdef CONFIG_SMP
+ this_cpu_add(mnt->mnt_pcp->mnt_count, n);
+#else
+ preempt_disable();
+ mnt->mnt_count += n;
+ preempt_enable();
+#endif
+}
+
+static inline void mnt_set_count(struct vfsmount *mnt, int n)
+{
+#ifdef CONFIG_SMP
+ this_cpu_write(mnt->mnt_pcp->mnt_count, n);
+#else
+ mnt->mnt_count = n;
+#endif
+}
+
+/*
+ * vfsmount lock must be held for read
+ */
+static inline void mnt_inc_count(struct vfsmount *mnt)
+{
+ mnt_add_count(mnt, 1);
+}
+
+/*
+ * vfsmount lock must be held for read
+ */
+static inline void mnt_dec_count(struct vfsmount *mnt)
+{
+ mnt_add_count(mnt, -1);
+}
+
+/*
+ * vfsmount lock must be held for write
+ */
+unsigned int mnt_get_count(struct vfsmount *mnt)
+{
+#ifdef CONFIG_SMP
+ unsigned int count = atomic_read(&mnt->mnt_longrefs);
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ count += per_cpu_ptr(mnt->mnt_pcp, cpu)->mnt_count;
+ }
+
+ return count;
+#else
+ return mnt->mnt_count;
+#endif
+}
+
struct vfsmount *alloc_vfsmnt(const char *name)
{
struct vfsmount *mnt = kmem_cache_zalloc(mnt_cache, GFP_KERNEL);
goto out_free_id;
}
- atomic_set(&mnt->mnt_count, 1);
+#ifdef CONFIG_SMP
+ mnt->mnt_pcp = alloc_percpu(struct mnt_pcp);
+ if (!mnt->mnt_pcp)
+ goto out_free_devname;
+
+ atomic_set(&mnt->mnt_longrefs, 1);
+#else
+ mnt->mnt_count = 1;
+ mnt->mnt_writers = 0;
+#endif
+
INIT_LIST_HEAD(&mnt->mnt_hash);
INIT_LIST_HEAD(&mnt->mnt_child);
INIT_LIST_HEAD(&mnt->mnt_mounts);
#ifdef CONFIG_FSNOTIFY
INIT_HLIST_HEAD(&mnt->mnt_fsnotify_marks);
#endif
-#ifdef CONFIG_SMP
- mnt->mnt_writers = alloc_percpu(int);
- if (!mnt->mnt_writers)
- goto out_free_devname;
-#else
- mnt->mnt_writers = 0;
-#endif
}
return mnt;
}
EXPORT_SYMBOL_GPL(__mnt_is_readonly);
-static inline void inc_mnt_writers(struct vfsmount *mnt)
+static inline void mnt_inc_writers(struct vfsmount *mnt)
{
#ifdef CONFIG_SMP
- (*per_cpu_ptr(mnt->mnt_writers, smp_processor_id()))++;
+ this_cpu_inc(mnt->mnt_pcp->mnt_writers);
#else
mnt->mnt_writers++;
#endif
}
-static inline void dec_mnt_writers(struct vfsmount *mnt)
+static inline void mnt_dec_writers(struct vfsmount *mnt)
{
#ifdef CONFIG_SMP
- (*per_cpu_ptr(mnt->mnt_writers, smp_processor_id()))--;
+ this_cpu_dec(mnt->mnt_pcp->mnt_writers);
#else
mnt->mnt_writers--;
#endif
}
-static unsigned int count_mnt_writers(struct vfsmount *mnt)
+static unsigned int mnt_get_writers(struct vfsmount *mnt)
{
#ifdef CONFIG_SMP
unsigned int count = 0;
int cpu;
for_each_possible_cpu(cpu) {
- count += *per_cpu_ptr(mnt->mnt_writers, cpu);
+ count += per_cpu_ptr(mnt->mnt_pcp, cpu)->mnt_writers;
}
return count;
int ret = 0;
preempt_disable();
- inc_mnt_writers(mnt);
+ mnt_inc_writers(mnt);
/*
- * The store to inc_mnt_writers must be visible before we pass
+ * The store to mnt_inc_writers must be visible before we pass
* MNT_WRITE_HOLD loop below, so that the slowpath can see our
* incremented count after it has set MNT_WRITE_HOLD.
*/
*/
smp_rmb();
if (__mnt_is_readonly(mnt)) {
- dec_mnt_writers(mnt);
+ mnt_dec_writers(mnt);
ret = -EROFS;
goto out;
}
if (__mnt_is_readonly(mnt))
return -EROFS;
preempt_disable();
- inc_mnt_writers(mnt);
+ mnt_inc_writers(mnt);
preempt_enable();
return 0;
}
void mnt_drop_write(struct vfsmount *mnt)
{
preempt_disable();
- dec_mnt_writers(mnt);
+ mnt_dec_writers(mnt);
preempt_enable();
}
EXPORT_SYMBOL_GPL(mnt_drop_write);
* MNT_WRITE_HOLD, so it can't be decremented by another CPU while
* we're counting up here.
*/
- if (count_mnt_writers(mnt) > 0)
+ if (mnt_get_writers(mnt) > 0)
ret = -EBUSY;
else
mnt->mnt_flags |= MNT_READONLY;
kfree(mnt->mnt_devname);
mnt_free_id(mnt);
#ifdef CONFIG_SMP
- free_percpu(mnt->mnt_writers);
+ free_percpu(mnt->mnt_pcp);
#endif
kmem_cache_free(mnt_cache, mnt);
}
}
/*
+ * Clear dentry's mounted state if it has no remaining mounts.
+ * vfsmount_lock must be held for write.
+ */
+static void dentry_reset_mounted(struct vfsmount *mnt, struct dentry *dentry)
+{
+ unsigned u;
+
+ for (u = 0; u < HASH_SIZE; u++) {
+ struct vfsmount *p;
+
+ list_for_each_entry(p, &mount_hashtable[u], mnt_hash) {
+ if (p->mnt_mountpoint == dentry)
+ return;
+ }
+ }
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags &= ~DCACHE_MOUNTED;
+ spin_unlock(&dentry->d_lock);
+}
+
+/*
* vfsmount lock must be held for write
*/
static void detach_mnt(struct vfsmount *mnt, struct path *old_path)
mnt->mnt_mountpoint = mnt->mnt_root;
list_del_init(&mnt->mnt_child);
list_del_init(&mnt->mnt_hash);
- old_path->dentry->d_mounted--;
+ dentry_reset_mounted(old_path->mnt, old_path->dentry);
}
/*
{
child_mnt->mnt_parent = mntget(mnt);
child_mnt->mnt_mountpoint = dget(dentry);
- dentry->d_mounted++;
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags |= DCACHE_MOUNTED;
+ spin_unlock(&dentry->d_lock);
}
/*
return NULL;
}
-static inline void __mntput(struct vfsmount *mnt)
+static inline void mntfree(struct vfsmount *mnt)
{
struct super_block *sb = mnt->mnt_sb;
+
/*
* This probably indicates that somebody messed
* up a mnt_want/drop_write() pair. If this
* to make r/w->r/o transitions.
*/
/*
- * atomic_dec_and_lock() used to deal with ->mnt_count decrements
- * provides barriers, so count_mnt_writers() below is safe. AV
+ * The locking used to deal with mnt_count decrement provides barriers,
+ * so mnt_get_writers() below is safe.
*/
- WARN_ON(count_mnt_writers(mnt));
+ WARN_ON(mnt_get_writers(mnt));
fsnotify_vfsmount_delete(mnt);
dput(mnt->mnt_root);
free_vfsmnt(mnt);
deactivate_super(sb);
}
-void mntput_no_expire(struct vfsmount *mnt)
-{
-repeat:
- if (atomic_add_unless(&mnt->mnt_count, -1, 1))
- return;
+#ifdef CONFIG_SMP
+static inline void __mntput(struct vfsmount *mnt, int longrefs)
+{
+ if (!longrefs) {
+put_again:
+ br_read_lock(vfsmount_lock);
+ if (likely(atomic_read(&mnt->mnt_longrefs))) {
+ mnt_dec_count(mnt);
+ br_read_unlock(vfsmount_lock);
+ return;
+ }
+ br_read_unlock(vfsmount_lock);
+ } else {
+ BUG_ON(!atomic_read(&mnt->mnt_longrefs));
+ if (atomic_add_unless(&mnt->mnt_longrefs, -1, 1))
+ return;
+ }
+
br_write_lock(vfsmount_lock);
- if (!atomic_dec_and_test(&mnt->mnt_count)) {
+ if (!longrefs)
+ mnt_dec_count(mnt);
+ else
+ atomic_dec(&mnt->mnt_longrefs);
+ if (mnt_get_count(mnt)) {
br_write_unlock(vfsmount_lock);
return;
}
- if (likely(!mnt->mnt_pinned)) {
+ if (unlikely(mnt->mnt_pinned)) {
+ mnt_add_count(mnt, mnt->mnt_pinned + 1);
+ mnt->mnt_pinned = 0;
br_write_unlock(vfsmount_lock);
- __mntput(mnt);
+ acct_auto_close_mnt(mnt);
+ goto put_again;
+ }
+ br_write_unlock(vfsmount_lock);
+ mntfree(mnt);
+}
+#else
+static inline void __mntput(struct vfsmount *mnt, int longrefs)
+{
+put_again:
+ mnt_dec_count(mnt);
+ if (likely(mnt_get_count(mnt)))
return;
+ br_write_lock(vfsmount_lock);
+ if (unlikely(mnt->mnt_pinned)) {
+ mnt_add_count(mnt, mnt->mnt_pinned + 1);
+ mnt->mnt_pinned = 0;
+ br_write_unlock(vfsmount_lock);
+ acct_auto_close_mnt(mnt);
+ goto put_again;
}
- atomic_add(mnt->mnt_pinned + 1, &mnt->mnt_count);
- mnt->mnt_pinned = 0;
br_write_unlock(vfsmount_lock);
- acct_auto_close_mnt(mnt);
- goto repeat;
+ mntfree(mnt);
+}
+#endif
+
+static void mntput_no_expire(struct vfsmount *mnt)
+{
+ __mntput(mnt, 0);
+}
+
+void mntput(struct vfsmount *mnt)
+{
+ if (mnt) {
+ /* avoid cacheline pingpong, hope gcc doesn't get "smart" */
+ if (unlikely(mnt->mnt_expiry_mark))
+ mnt->mnt_expiry_mark = 0;
+ __mntput(mnt, 0);
+ }
+}
+EXPORT_SYMBOL(mntput);
+
+struct vfsmount *mntget(struct vfsmount *mnt)
+{
+ if (mnt)
+ mnt_inc_count(mnt);
+ return mnt;
}
-EXPORT_SYMBOL(mntput_no_expire);
+EXPORT_SYMBOL(mntget);
+
+void mntput_long(struct vfsmount *mnt)
+{
+#ifdef CONFIG_SMP
+ if (mnt) {
+ /* avoid cacheline pingpong, hope gcc doesn't get "smart" */
+ if (unlikely(mnt->mnt_expiry_mark))
+ mnt->mnt_expiry_mark = 0;
+ __mntput(mnt, 1);
+ }
+#else
+ mntput(mnt);
+#endif
+}
+EXPORT_SYMBOL(mntput_long);
+
+struct vfsmount *mntget_long(struct vfsmount *mnt)
+{
+#ifdef CONFIG_SMP
+ if (mnt)
+ atomic_inc(&mnt->mnt_longrefs);
+ return mnt;
+#else
+ return mntget(mnt);
+#endif
+}
+EXPORT_SYMBOL(mntget_long);
void mnt_pin(struct vfsmount *mnt)
{
mnt->mnt_pinned++;
br_write_unlock(vfsmount_lock);
}
-
EXPORT_SYMBOL(mnt_pin);
void mnt_unpin(struct vfsmount *mnt)
{
br_write_lock(vfsmount_lock);
if (mnt->mnt_pinned) {
- atomic_inc(&mnt->mnt_count);
+ mnt_inc_count(mnt);
mnt->mnt_pinned--;
}
br_write_unlock(vfsmount_lock);
}
-
EXPORT_SYMBOL(mnt_unpin);
static inline void mangle(struct seq_file *m, const char *s)
int minimum_refs = 0;
struct vfsmount *p;
- br_read_lock(vfsmount_lock);
+ /* write lock needed for mnt_get_count */
+ br_write_lock(vfsmount_lock);
for (p = mnt; p; p = next_mnt(p, mnt)) {
- actual_refs += atomic_read(&p->mnt_count);
+ actual_refs += mnt_get_count(p);
minimum_refs += 2;
}
- br_read_unlock(vfsmount_lock);
+ br_write_unlock(vfsmount_lock);
if (actual_refs > minimum_refs)
return 0;
{
int ret = 1;
down_read(&namespace_sem);
- br_read_lock(vfsmount_lock);
+ br_write_lock(vfsmount_lock);
if (propagate_mount_busy(mnt, 2))
ret = 0;
- br_read_unlock(vfsmount_lock);
+ br_write_unlock(vfsmount_lock);
up_read(&namespace_sem);
return ret;
}
dput(dentry);
mntput(m);
}
- mntput(mnt);
+ mntput_long(mnt);
}
}
list_del_init(&p->mnt_child);
if (p->mnt_parent != p) {
p->mnt_parent->mnt_ghosts++;
- p->mnt_mountpoint->d_mounted--;
+ dentry_reset_mounted(p->mnt_parent, p->mnt_mountpoint);
}
change_mnt_propagation(p, MS_PRIVATE);
}
flags & (MNT_FORCE | MNT_DETACH))
return -EINVAL;
- if (atomic_read(&mnt->mnt_count) != 2)
+ /*
+ * probably don't strictly need the lock here if we examined
+ * all race cases, but it's a slowpath.
+ */
+ br_write_lock(vfsmount_lock);
+ if (mnt_get_count(mnt) != 2) {
+ br_write_lock(vfsmount_lock);
return -EBUSY;
+ }
+ br_write_unlock(vfsmount_lock);
if (!xchg(&mnt->mnt_expiry_mark, 1))
return -EAGAIN;
unlock:
up_write(&namespace_sem);
- mntput(newmnt);
+ mntput_long(newmnt);
return err;
}
if (fs) {
if (p == fs->root.mnt) {
rootmnt = p;
- fs->root.mnt = mntget(q);
+ fs->root.mnt = mntget_long(q);
}
if (p == fs->pwd.mnt) {
pwdmnt = p;
- fs->pwd.mnt = mntget(q);
+ fs->pwd.mnt = mntget_long(q);
}
}
p = next_mnt(p, mnt_ns->root);
up_write(&namespace_sem);
if (rootmnt)
- mntput(rootmnt);
+ mntput_long(rootmnt);
if (pwdmnt)
- mntput(pwdmnt);
+ mntput_long(pwdmnt);
return new_ns;
}
touch_mnt_namespace(current->nsproxy->mnt_ns);
br_write_unlock(vfsmount_lock);
chroot_fs_refs(&root, &new);
+
error = 0;
path_put(&root_parent);
path_put(&parent_path);
mnt = do_kern_mount("rootfs", 0, "rootfs", NULL);
if (IS_ERR(mnt))
panic("Can't create rootfs");
+
ns = create_mnt_ns(mnt);
if (IS_ERR(ns))
panic("Can't allocate initial namespace");
#include <linux/kernel.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
+#include <linux/namei.h>
#include <asm/uaccess.h>
#include <asm/byteorder.h>
* Dentry operations routines
*/
static int ncp_lookup_validate(struct dentry *, struct nameidata *);
-static int ncp_hash_dentry(struct dentry *, struct qstr *);
-static int ncp_compare_dentry (struct dentry *, struct qstr *, struct qstr *);
-static int ncp_delete_dentry(struct dentry *);
+static int ncp_hash_dentry(const struct dentry *, const struct inode *,
+ struct qstr *);
+static int ncp_compare_dentry(const struct dentry *, const struct inode *,
+ const struct dentry *, const struct inode *,
+ unsigned int, const char *, const struct qstr *);
+static int ncp_delete_dentry(const struct dentry *);
static const struct dentry_operations ncp_dentry_operations =
{
#define ncp_preserve_case(i) (ncp_namespace(i) != NW_NS_DOS)
-static inline int ncp_case_sensitive(struct dentry *dentry)
+static inline int ncp_case_sensitive(const struct inode *i)
{
#ifdef CONFIG_NCPFS_NFS_NS
- return ncp_namespace(dentry->d_inode) == NW_NS_NFS;
+ return ncp_namespace(i) == NW_NS_NFS;
#else
return 0;
#endif /* CONFIG_NCPFS_NFS_NS */
* is case-sensitive.
*/
static int
-ncp_hash_dentry(struct dentry *dentry, struct qstr *this)
+ncp_hash_dentry(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *this)
{
- if (!ncp_case_sensitive(dentry)) {
+ if (!ncp_case_sensitive(inode)) {
+ struct super_block *sb = dentry->d_sb;
struct nls_table *t;
unsigned long hash;
int i;
- t = NCP_IO_TABLE(dentry);
+ t = NCP_IO_TABLE(sb);
hash = init_name_hash();
for (i=0; i<this->len ; i++)
hash = partial_name_hash(ncp_tolower(t, this->name[i]),
}
static int
-ncp_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b)
+ncp_compare_dentry(const struct dentry *parent, const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name)
{
- if (a->len != b->len)
+ if (len != name->len)
return 1;
- if (ncp_case_sensitive(dentry))
- return strncmp(a->name, b->name, a->len);
+ if (ncp_case_sensitive(pinode))
+ return strncmp(str, name->name, len);
- return ncp_strnicmp(NCP_IO_TABLE(dentry), a->name, b->name, a->len);
+ return ncp_strnicmp(NCP_IO_TABLE(pinode->i_sb), str, name->name, len);
}
/*
* Closing files can be safely postponed until iput() - it's done there anyway.
*/
static int
-ncp_delete_dentry(struct dentry * dentry)
+ncp_delete_dentry(const struct dentry * dentry)
{
struct inode *inode = dentry->d_inode;
int res, val = 0, len;
__u8 __name[NCP_MAXPATHLEN + 1];
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
parent = dget_parent(dentry);
dir = parent->d_inode;
}
/* If a pointer is invalid, we search the dentry. */
- spin_lock(&dcache_lock);
+ spin_lock(&parent->d_lock);
next = parent->d_subdirs.next;
while (next != &parent->d_subdirs) {
dent = list_entry(next, struct dentry, d_u.d_child);
if ((unsigned long)dent->d_fsdata == fpos) {
if (dent->d_inode)
- dget_locked(dent);
+ dget(dent);
else
dent = NULL;
- spin_unlock(&dcache_lock);
+ spin_unlock(&parent->d_lock);
goto out;
}
next = next->next;
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&parent->d_lock);
return NULL;
out:
qname.hash = full_name_hash(qname.name, qname.len);
if (dentry->d_op && dentry->d_op->d_hash)
- if (dentry->d_op->d_hash(dentry, &qname) != 0)
+ if (dentry->d_op->d_hash(dentry, dentry->d_inode, &qname) != 0)
goto end_advance;
newdent = d_lookup(dentry, &qname);
shrink_dcache_parent(newdent);
/*
- * It is not as dangerous as it looks. NetWare's OS2 namespace is
- * case preserving yet case insensitive. So we update dentry's name
- * as received from server. We found dentry via d_lookup with our
- * hash, so we know that hash does not change, and so replacing name
- * should be reasonably safe.
+ * NetWare's OS2 namespace is case preserving yet case
+ * insensitive. So we update dentry's name as received from
+ * server. Parent dir's i_mutex is locked because we're in
+ * readdir.
*/
- if (qname.len == newdent->d_name.len &&
- memcmp(newdent->d_name.name, qname.name, newdent->d_name.len)) {
- struct inode *inode = newdent->d_inode;
-
- /*
- * Inside ncpfs all uses of d_name are either for debugging,
- * or on functions which acquire inode mutex (mknod, creat,
- * lookup). So grab i_mutex here, to be sure. d_path
- * uses dcache_lock when generating path, so we should too.
- * And finally d_compare is protected by dentry's d_lock, so
- * here we go.
- */
- if (inode)
- mutex_lock(&inode->i_mutex);
- spin_lock(&dcache_lock);
- spin_lock(&newdent->d_lock);
- memcpy((char *) newdent->d_name.name, qname.name,
- newdent->d_name.len);
- spin_unlock(&newdent->d_lock);
- spin_unlock(&dcache_lock);
- if (inode)
- mutex_unlock(&inode->i_mutex);
- }
+ dentry_update_name_case(newdent, &qname);
}
if (!newdent->d_inode) {
entry->ino = iunique(dir->i_sb, 2);
inode = ncp_iget(dir->i_sb, entry);
if (inode) {
- newdent->d_op = &ncp_dentry_operations;
+ d_set_d_op(newdent, &ncp_dentry_operations);
d_instantiate(newdent, inode);
if (!hashed)
d_rehash(newdent);
} else {
struct inode *inode = newdent->d_inode;
- mutex_lock(&inode->i_mutex);
+ mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
ncp_update_inode2(inode, entry);
mutex_unlock(&inode->i_mutex);
}
if (inode) {
ncp_new_dentry(dentry);
add_entry:
- dentry->d_op = &ncp_dentry_operations;
+ d_set_d_op(dentry, &ncp_dentry_operations);
d_add(dentry, inode);
error = 0;
}
#include <linux/vfs.h>
#include <linux/mount.h>
#include <linux/seq_file.h>
+#include <linux/namei.h>
#include <linux/ncp_fs.h>
return &ei->vfs_inode;
}
-static void ncp_destroy_inode(struct inode *inode)
+static void ncp_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(ncp_inode_cachep, NCP_FINFO(inode));
}
+static void ncp_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, ncp_i_callback);
+}
+
static void init_once(void *foo)
{
struct ncp_inode_info *ei = (struct ncp_inode_info *) foo;
sb->s_root = d_alloc_root(root_inode);
if (!sb->s_root)
goto out_no_root;
- sb->s_root->d_op = &ncp_root_dentry_operations;
+ d_set_d_op(sb->s_root, &ncp_root_dentry_operations);
return 0;
out_no_root:
const unsigned char *, unsigned int, int);
#define NCP_ESC ':'
-#define NCP_IO_TABLE(dentry) (NCP_SERVER((dentry)->d_inode)->nls_io)
+#define NCP_IO_TABLE(sb) (NCP_SBP(sb)->nls_io)
#define ncp_tolower(t, c) nls_tolower(t, c)
#define ncp_toupper(t, c) nls_toupper(t, c)
#define ncp_strnicmp(t, s1, s2, len) \
int ncp__vol2io(unsigned char *, unsigned int *,
const unsigned char *, unsigned int, int);
-#define NCP_IO_TABLE(dentry) NULL
+#define NCP_IO_TABLE(sb) NULL
#define ncp_tolower(t, c) tolower(c)
#define ncp_toupper(t, c) toupper(c)
#define ncp_io2vol(S,m,i,n,k,U) ncp__io2vol(m,i,n,k,U)
#define ncp_vol2io(S,m,i,n,k,U) ncp__vol2io(m,i,n,k,U)
-static inline int ncp_strnicmp(struct nls_table *t, const unsigned char *s1,
- const unsigned char *s2, int len)
+static inline int ncp_strnicmp(const struct nls_table *t,
+ const unsigned char *s1, const unsigned char *s2, int len)
{
while (len--) {
if (tolower(*s1++) != tolower(*s2++))
struct list_head *next;
struct dentry *dentry;
- spin_lock(&dcache_lock);
+ spin_lock(&parent->d_lock);
next = parent->d_subdirs.next;
while (next != &parent->d_subdirs) {
dentry = list_entry(next, struct dentry, d_u.d_child);
next = next->next;
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&parent->d_lock);
}
static inline void
struct list_head *next;
struct dentry *dentry;
- spin_lock(&dcache_lock);
+ spin_lock(&parent->d_lock);
next = parent->d_subdirs.next;
while (next != &parent->d_subdirs) {
dentry = list_entry(next, struct dentry, d_u.d_child);
ncp_age_dentry(server, dentry);
next = next->next;
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&parent->d_lock);
}
struct ncp_cache_head {
if (dentry == NULL)
return;
- dentry->d_op = NFS_PROTO(dir)->dentry_ops;
+ d_set_d_op(dentry, NFS_PROTO(dir)->dentry_ops);
inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr);
if (IS_ERR(inode))
goto out;
* component of the path.
* We check for this using LOOKUP_CONTINUE and LOOKUP_PARENT.
*/
-static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd, unsigned int mask)
+static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd,
+ unsigned int mask)
{
if (nd->flags & (LOOKUP_CONTINUE|LOOKUP_PARENT))
return 0;
* If the parent directory is seen to have changed, we throw out the
* cached dentry and do a new lookup.
*/
-static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd)
+static int nfs_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
{
struct inode *dir;
struct inode *inode;
struct nfs_fattr *fattr = NULL;
int error;
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
parent = dget_parent(dentry);
dir = parent->d_inode;
nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
/*
* This is called from dput() when d_count is going to 0.
*/
-static int nfs_dentry_delete(struct dentry *dentry)
+static int nfs_dentry_delete(const struct dentry *dentry)
{
dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n",
dentry->d_parent->d_name.name, dentry->d_name.name,
if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
goto out;
- dentry->d_op = NFS_PROTO(dir)->dentry_ops;
+ d_set_d_op(dentry, NFS_PROTO(dir)->dentry_ops);
/*
* If we're doing an exclusive create, optimize away the lookup
res = ERR_PTR(-ENAMETOOLONG);
goto out;
}
- dentry->d_op = NFS_PROTO(dir)->dentry_ops;
+ d_set_d_op(dentry, NFS_PROTO(dir)->dentry_ops);
/* Let vfs_create() deal with O_EXCL. Instantiate, but don't hash
* the dentry. */
dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id,
dir->i_ino, dentry->d_name.name);
- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
- if (atomic_read(&dentry->d_count) > 1) {
+ if (dentry->d_count > 1) {
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
/* Start asynchronous writeout of the inode */
write_inode_now(dentry->d_inode, 0);
error = nfs_sillyrename(dir, dentry);
need_rehash = 1;
}
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
error = nfs_safe_remove(dentry);
if (!error || error == -ENOENT) {
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
dfprintk(VFS, "NFS: rename(%s/%s -> %s/%s, ct=%d)\n",
old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
new_dentry->d_parent->d_name.name, new_dentry->d_name.name,
- atomic_read(&new_dentry->d_count));
+ new_dentry->d_count);
/*
* For non-directories, check whether the target is busy and if so,
rehash = new_dentry;
}
- if (atomic_read(&new_dentry->d_count) > 2) {
+ if (new_dentry->d_count > 2) {
int err;
/* copy the target dentry's name */
return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags));
}
-int nfs_permission(struct inode *inode, int mask)
+int nfs_permission(struct inode *inode, int mask, unsigned int flags)
{
struct rpc_cred *cred;
int res = 0;
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
+
nfs_inc_stats(inode, NFSIOS_VFSACCESS);
if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
out_notsup:
res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
if (res == 0)
- res = generic_permission(inode, mask, NULL);
+ res = generic_permission(inode, mask, flags, NULL);
goto out;
}
* This again causes shrink_dcache_for_umount_subtree() to
* Oops, since the test for IS_ROOT() will fail.
*/
- spin_lock(&dcache_lock);
+ spin_lock(&sb->s_root->d_inode->i_lock);
+ spin_lock(&sb->s_root->d_lock);
list_del_init(&sb->s_root->d_alias);
- spin_unlock(&dcache_lock);
+ spin_unlock(&sb->s_root->d_lock);
+ spin_unlock(&sb->s_root->d_inode->i_lock);
}
return 0;
}
security_d_instantiate(ret, inode);
if (ret->d_op == NULL)
- ret->d_op = server->nfs_client->rpc_ops->dentry_ops;
+ d_set_d_op(ret, server->nfs_client->rpc_ops->dentry_ops);
out:
nfs_free_fattr(fsinfo.fattr);
return ret;
security_d_instantiate(ret, inode);
if (ret->d_op == NULL)
- ret->d_op = server->nfs_client->rpc_ops->dentry_ops;
+ d_set_d_op(ret, server->nfs_client->rpc_ops->dentry_ops);
out:
nfs_free_fattr(fattr);
return &nfsi->vfs_inode;
}
-void nfs_destroy_inode(struct inode *inode)
+static void nfs_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
}
+void nfs_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, nfs_i_callback);
+}
+
static inline void nfs4_init_once(struct nfs_inode *nfsi)
{
#ifdef CONFIG_NFS_V4
const struct dentry *dentry,
char *buffer, ssize_t buflen)
{
- char *end = buffer+buflen;
+ char *end;
int namelen;
+ unsigned seq;
+rename_retry:
+ end = buffer+buflen;
*--end = '\0';
buflen--;
- spin_lock(&dcache_lock);
+
+ seq = read_seqbegin(&rename_lock);
+ rcu_read_lock();
while (!IS_ROOT(dentry) && dentry != droot) {
namelen = dentry->d_name.len;
buflen -= namelen + 1;
*--end = '/';
dentry = dentry->d_parent;
}
- spin_unlock(&dcache_lock);
+ rcu_read_unlock();
+ if (read_seqretry(&rename_lock, seq))
+ goto rename_retry;
if (*end != '/') {
if (--buflen < 0)
goto Elong;
memcpy(end, base, namelen);
return end;
Elong_unlock:
- spin_unlock(&dcache_lock);
+ rcu_read_unlock();
+ if (read_seqretry(&rename_lock, seq))
+ goto rename_retry;
Elong:
return ERR_PTR(-ENAMETOOLONG);
}
dfprintk(VFS, "NFS: silly-rename(%s/%s, ct=%d)\n",
dentry->d_parent->d_name.name, dentry->d_name.name,
- atomic_read(&dentry->d_count));
+ dentry->d_count);
nfs_inc_stats(dir, NFSIOS_SILLYRENAME);
/*
goto out_dput_new;
if (svc_msnfs(ffhp) &&
- ((atomic_read(&odentry->d_count) > 1)
- || (atomic_read(&ndentry->d_count) > 1))) {
+ ((odentry->d_count > 1) || (ndentry->d_count > 1))) {
host_err = -EPERM;
goto out_dput_new;
}
if (type != S_IFDIR) { /* It's UNLINK */
#ifdef MSNFS
if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
- (atomic_read(&rdentry->d_count) > 1)) {
+ (rdentry->d_count > 1)) {
host_err = -EPERM;
} else
#endif
return err;
}
-int nilfs_permission(struct inode *inode, int mask)
+int nilfs_permission(struct inode *inode, int mask, unsigned int flags)
{
- struct nilfs_root *root = NILFS_I(inode)->i_root;
+ struct nilfs_root *root;
+
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
+ root = NILFS_I(inode)->i_root;
if ((mask & MAY_WRITE) && root &&
root->cno != NILFS_CPTREE_CURRENT_CNO)
return -EROFS; /* snapshot is not writable */
- return generic_permission(inode, mask, NULL);
+ return generic_permission(inode, mask, flags, NULL);
}
int nilfs_load_inode_block(struct nilfs_sb_info *sbi, struct inode *inode,
extern void nilfs_truncate(struct inode *);
extern void nilfs_evict_inode(struct inode *);
extern int nilfs_setattr(struct dentry *, struct iattr *);
-int nilfs_permission(struct inode *inode, int mask);
+int nilfs_permission(struct inode *inode, int mask, unsigned int flags);
extern int nilfs_load_inode_block(struct nilfs_sb_info *, struct inode *,
struct buffer_head **);
extern int nilfs_inode_dirty(struct inode *);
return &ii->vfs_inode;
}
-void nilfs_destroy_inode(struct inode *inode)
+static void nilfs_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
+ INIT_LIST_HEAD(&inode->i_dentry);
+
if (mdi) {
kfree(mdi->mi_bgl); /* kfree(NULL) is safe */
kfree(mdi);
kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
}
+void nilfs_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, nilfs_i_callback);
+}
+
static int nilfs_sync_super(struct nilfs_sb_info *sbi, int flag)
{
struct the_nilfs *nilfs = sbi->s_nilfs;
static int nilfs_tree_was_touched(struct dentry *root_dentry)
{
- return atomic_read(&root_dentry->d_count) > 1;
+ return root_dentry->d_count > 1;
}
/**
/* determine if the children should tell inode about their events */
watched = fsnotify_inode_watches_children(inode);
- spin_lock(&dcache_lock);
+ spin_lock(&inode->i_lock);
/* run all of the dentries associated with this inode. Since this is a
* directory, there damn well better only be one item on this list */
list_for_each_entry(alias, &inode->i_dentry, d_alias) {
/* run all of the children of the original inode and fix their
* d_flags to indicate parental interest (their parent is the
* original inode) */
+ spin_lock(&alias->d_lock);
list_for_each_entry(child, &alias->d_subdirs, d_u.d_child) {
if (!child->d_inode)
continue;
- spin_lock(&child->d_lock);
+ spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED);
if (watched)
child->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED;
else
child->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED;
spin_unlock(&child->d_lock);
}
+ spin_unlock(&alias->d_lock);
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&inode->i_lock);
}
/* Notify this dentry's parent about a child's events. */
return NULL;
}
+static void ntfs_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
+ kmem_cache_free(ntfs_big_inode_cache, NTFS_I(inode));
+}
+
void ntfs_destroy_big_inode(struct inode *inode)
{
ntfs_inode *ni = NTFS_I(inode);
BUG_ON(ni->page);
if (!atomic_dec_and_test(&ni->count))
BUG();
- kmem_cache_free(ntfs_big_inode_cache, NTFS_I(inode));
+ call_rcu(&inode->i_rcu, ntfs_i_callback);
}
static inline ntfs_inode *ntfs_alloc_extent_inode(void)
return ret;
}
-int ocfs2_check_acl(struct inode *inode, int mask)
+int ocfs2_check_acl(struct inode *inode, int mask, unsigned int flags)
{
- struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ struct ocfs2_super *osb;
struct buffer_head *di_bh = NULL;
struct posix_acl *acl;
int ret = -EAGAIN;
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
+
+ osb = OCFS2_SB(inode->i_sb);
if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
return ret;
__le32 e_id;
};
-extern int ocfs2_check_acl(struct inode *, int);
+extern int ocfs2_check_acl(struct inode *, int, unsigned int);
extern int ocfs2_acl_chmod(struct inode *);
extern int ocfs2_init_acl(handle_t *, struct inode *, struct inode *,
struct buffer_head *, struct buffer_head *,
static int ocfs2_dentry_revalidate(struct dentry *dentry,
struct nameidata *nd)
{
- struct inode *inode = dentry->d_inode;
+ struct inode *inode;
int ret = 0; /* if all else fails, just return false */
- struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
+ struct ocfs2_super *osb;
+
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ inode = dentry->d_inode;
+ osb = OCFS2_SB(dentry->d_sb);
mlog_entry("(0x%p, '%.*s')\n", dentry,
dentry->d_name.len, dentry->d_name.name);
struct list_head *p;
struct dentry *dentry = NULL;
- spin_lock(&dcache_lock);
-
+ spin_lock(&inode->i_lock);
list_for_each(p, &inode->i_dentry) {
dentry = list_entry(p, struct dentry, d_alias);
+ spin_lock(&dentry->d_lock);
if (ocfs2_match_dentry(dentry, parent_blkno, skip_unhashed)) {
mlog(0, "dentry found: %.*s\n",
dentry->d_name.len, dentry->d_name.name);
- dget_locked(dentry);
+ dget_dlock(dentry);
+ spin_unlock(&dentry->d_lock);
break;
}
+ spin_unlock(&dentry->d_lock);
dentry = NULL;
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&inode->i_lock);
return dentry;
}
return &ip->ip_vfs_inode;
}
-static void dlmfs_destroy_inode(struct inode *inode)
+static void dlmfs_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(dlmfs_inode_cache, DLMFS_I(inode));
}
+static void dlmfs_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, dlmfs_i_callback);
+}
+
static void dlmfs_evict_inode(struct inode *inode)
{
int status;
result = d_obtain_alias(inode);
if (!IS_ERR(result))
- result->d_op = &ocfs2_dentry_ops;
+ d_set_d_op(result, &ocfs2_dentry_ops);
else
mlog_errno(PTR_ERR(result));
parent = d_obtain_alias(ocfs2_iget(OCFS2_SB(dir->i_sb), blkno, 0, 0));
if (!IS_ERR(parent))
- parent->d_op = &ocfs2_dentry_ops;
+ d_set_d_op(parent, &ocfs2_dentry_ops);
bail_unlock:
ocfs2_inode_unlock(dir, 0);
return err;
}
-int ocfs2_permission(struct inode *inode, int mask)
+int ocfs2_permission(struct inode *inode, int mask, unsigned int flags)
{
int ret;
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
+
mlog_entry_void();
ret = ocfs2_inode_lock(inode, NULL, 0);
goto out;
}
- ret = generic_permission(inode, mask, ocfs2_check_acl);
+ ret = generic_permission(inode, mask, flags, ocfs2_check_acl);
ocfs2_inode_unlock(inode, 0);
out:
int ocfs2_setattr(struct dentry *dentry, struct iattr *attr);
int ocfs2_getattr(struct vfsmount *mnt, struct dentry *dentry,
struct kstat *stat);
-int ocfs2_permission(struct inode *inode, int mask);
+int ocfs2_permission(struct inode *inode, int mask, unsigned int flags);
int ocfs2_should_update_atime(struct inode *inode,
struct vfsmount *vfsmnt);
spin_unlock(&oi->ip_lock);
bail_add:
- dentry->d_op = &ocfs2_dentry_ops;
+ d_set_d_op(dentry, &ocfs2_dentry_ops);
ret = d_splice_alias(inode, dentry);
if (inode) {
mlog_errno(status);
goto leave;
}
- dentry->d_op = &ocfs2_dentry_ops;
+ d_set_d_op(dentry, &ocfs2_dentry_ops);
status = ocfs2_add_entry(handle, dentry, inode,
OCFS2_I(inode)->ip_blkno, parent_fe_bh,
}
ihold(inode);
- dentry->d_op = &ocfs2_dentry_ops;
+ d_set_d_op(dentry, &ocfs2_dentry_ops);
d_instantiate(dentry, inode);
out_commit:
mlog_errno(status);
goto bail;
}
- dentry->d_op = &ocfs2_dentry_ops;
+ d_set_d_op(dentry, &ocfs2_dentry_ops);
status = ocfs2_add_entry(handle, dentry, inode,
le64_to_cpu(fe->i_blkno), parent_fe_bh,
goto out_commit;
}
- dentry->d_op = &ocfs2_dentry_ops;
+ d_set_d_op(dentry, &ocfs2_dentry_ops);
d_instantiate(dentry, inode);
status = 0;
out_commit:
return &oi->vfs_inode;
}
-static void ocfs2_destroy_inode(struct inode *inode)
+static void ocfs2_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(ocfs2_inode_cachep, OCFS2_I(inode));
}
+static void ocfs2_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, ocfs2_i_callback);
+}
+
static unsigned long long ocfs2_max_file_offset(unsigned int bbits,
unsigned int cbits)
{
return &oi->vfs_inode;
}
-static void openprom_destroy_inode(struct inode *inode)
+static void openprom_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(op_inode_cachep, OP_I(inode));
}
+static void openprom_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, openprom_i_callback);
+}
+
static struct inode *openprom_iget(struct super_block *sb, ino_t ino)
{
struct inode *inode;
goto err;
err = -ENOMEM;
- path.dentry = d_alloc(pipe_mnt->mnt_sb->s_root, &name);
+ path.dentry = d_alloc_pseudo(pipe_mnt->mnt_sb, &name);
if (!path.dentry)
goto err_inode;
path.mnt = mntget(pipe_mnt);
- path.dentry->d_op = &pipefs_dentry_operations;
+ d_set_d_op(path.dentry, &pipefs_dentry_operations);
d_instantiate(path.dentry, inode);
err = -ENFILE;
return ret;
}
+static const struct super_operations pipefs_ops = {
+ .destroy_inode = free_inode_nonrcu,
+};
+
/*
* pipefs should _never_ be mounted by userland - too much of security hassle,
* no real gain from having the whole whorehouse mounted. So we don't need
static struct dentry *pipefs_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
- return mount_pseudo(fs_type, "pipe:", NULL, PIPEFS_MAGIC);
+ return mount_pseudo(fs_type, "pipe:", &pipefs_ops, PIPEFS_MAGIC);
}
static struct file_system_type pipe_fs_type = {
static void __exit exit_pipe_fs(void)
{
unregister_filesystem(&pipe_fs_type);
- mntput(pipe_mnt);
+ mntput_long(pipe_mnt);
}
fs_initcall(init_pipe_fs);
*/
static inline int do_refcount_check(struct vfsmount *mnt, int count)
{
- int mycount = atomic_read(&mnt->mnt_count) - mnt->mnt_ghosts;
+ int mycount = mnt_get_count(mnt) - mnt->mnt_ghosts;
return (mycount > count);
}
* Check if any of these mounts that **do not have submounts**
* have more references than 'refcnt'. If so return busy.
*
- * vfsmount lock must be held for read or write
+ * vfsmount lock must be held for write
*/
int propagate_mount_busy(struct vfsmount *mnt, int refcnt)
{
*/
static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
{
- struct inode *inode = dentry->d_inode;
- struct task_struct *task = get_proc_task(inode);
+ struct inode *inode;
+ struct task_struct *task;
const struct cred *cred;
+ if (nd && nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ inode = dentry->d_inode;
+ task = get_proc_task(inode);
+
if (task) {
if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
task_dumpable(task)) {
return 0;
}
-static int pid_delete_dentry(struct dentry * dentry)
+static int pid_delete_dentry(const struct dentry * dentry)
{
/* Is the task we represent dead?
* If so, then don't put the dentry on the lru list,
static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
{
- struct inode *inode = dentry->d_inode;
- struct task_struct *task = get_proc_task(inode);
- int fd = proc_fd(inode);
+ struct inode *inode;
+ struct task_struct *task;
+ int fd;
struct files_struct *files;
const struct cred *cred;
+ if (nd && nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ inode = dentry->d_inode;
+ task = get_proc_task(inode);
+ fd = proc_fd(inode);
+
if (task) {
files = get_files_struct(task);
if (files) {
inode->i_op = &proc_pid_link_inode_operations;
inode->i_size = 64;
ei->op.proc_get_link = proc_fd_link;
- dentry->d_op = &tid_fd_dentry_operations;
+ d_set_d_op(dentry, &tid_fd_dentry_operations);
d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
if (tid_fd_revalidate(dentry, NULL))
* /proc/pid/fd needs a special permission handler so that a process can still
* access /proc/self/fd after it has executed a setuid().
*/
-static int proc_fd_permission(struct inode *inode, int mask)
+static int proc_fd_permission(struct inode *inode, int mask, unsigned int flags)
{
int rv;
- rv = generic_permission(inode, mask, NULL);
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
+ rv = generic_permission(inode, mask, flags, NULL);
if (rv == 0)
return 0;
if (task_pid(current) == proc_pid(inode))
ei->fd = fd;
inode->i_mode = S_IFREG | S_IRUSR;
inode->i_fop = &proc_fdinfo_file_operations;
- dentry->d_op = &tid_fd_dentry_operations;
+ d_set_d_op(dentry, &tid_fd_dentry_operations);
d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
if (tid_fd_revalidate(dentry, NULL))
if (p->fop)
inode->i_fop = p->fop;
ei->op = p->op;
- dentry->d_op = &pid_dentry_operations;
+ d_set_d_op(dentry, &pid_dentry_operations);
d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
if (pid_revalidate(dentry, NULL))
*/
static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd)
{
- struct inode *inode = dentry->d_inode;
- struct task_struct *task = get_proc_task(inode);
+ struct inode *inode;
+ struct task_struct *task;
+
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ inode = dentry->d_inode;
+ task = get_proc_task(inode);
if (task) {
put_task_struct(task);
return 1;
if (p->fop)
inode->i_fop = p->fop;
ei->op = p->op;
- dentry->d_op = &proc_base_dentry_operations;
+ d_set_d_op(dentry, &proc_base_dentry_operations);
d_add(dentry, inode);
error = NULL;
out:
inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff,
ARRAY_SIZE(tgid_base_stuff));
- dentry->d_op = &pid_dentry_operations;
+ d_set_d_op(dentry, &pid_dentry_operations);
d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff,
ARRAY_SIZE(tid_base_stuff));
- dentry->d_op = &pid_dentry_operations;
+ d_set_d_op(dentry, &pid_dentry_operations);
d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
* smarter: we could keep a "volatile" flag in the
* inode to indicate which ones to keep.
*/
-static int proc_delete_dentry(struct dentry * dentry)
+static int proc_delete_dentry(const struct dentry * dentry)
{
return 1;
}
out_unlock:
if (inode) {
- dentry->d_op = &proc_dentry_operations;
+ d_set_d_op(dentry, &proc_dentry_operations);
d_add(dentry, inode);
return NULL;
}
return inode;
}
-static void proc_destroy_inode(struct inode *inode)
+static void proc_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(proc_inode_cachep, PROC_I(inode));
}
+static void proc_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, proc_i_callback);
+}
+
static void init_once(void *foo)
{
struct proc_inode *ei = (struct proc_inode *) foo;
#include <linux/sysctl.h>
#include <linux/proc_fs.h>
#include <linux/security.h>
+#include <linux/namei.h>
#include "internal.h"
static const struct dentry_operations proc_sys_dentry_operations;
goto out;
err = NULL;
- dentry->d_op = &proc_sys_dentry_operations;
+ d_set_d_op(dentry, &proc_sys_dentry_operations);
d_add(dentry, inode);
out:
dput(child);
return -ENOMEM;
} else {
- child->d_op = &proc_sys_dentry_operations;
+ d_set_d_op(child, &proc_sys_dentry_operations);
d_add(child, inode);
}
} else {
return ret;
}
-static int proc_sys_permission(struct inode *inode, int mask)
+static int proc_sys_permission(struct inode *inode, int mask,unsigned int flags)
{
/*
* sysctl entries that are not writeable,
struct ctl_table *table;
int error;
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
+
/* Executable files are not allowed under /proc/sys/ */
if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode))
return -EACCES;
static int proc_sys_revalidate(struct dentry *dentry, struct nameidata *nd)
{
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
return !PROC_I(dentry->d_inode)->sysctl->unregistering;
}
-static int proc_sys_delete(struct dentry *dentry)
+static int proc_sys_delete(const struct dentry *dentry)
{
return !!PROC_I(dentry->d_inode)->sysctl->unregistering;
}
-static int proc_sys_compare(struct dentry *dir, struct qstr *qstr,
- struct qstr *name)
+static int proc_sys_compare(const struct dentry *parent,
+ const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name)
{
- struct dentry *dentry = container_of(qstr, struct dentry, d_name);
- if (qstr->len != name->len)
+ /* Although proc doesn't have negative dentries, rcu-walk means
+ * that inode here can be NULL */
+ if (!inode)
+ return 0;
+ if (name->len != len)
return 1;
- if (memcmp(qstr->name, name->name, name->len))
+ if (memcmp(name->name, str, len))
return 1;
- return !sysctl_is_seen(PROC_I(dentry->d_inode)->sysctl);
+ return !sysctl_is_seen(PROC_I(inode)->sysctl);
}
static const struct dentry_operations proc_sys_dentry_operations = {
return &ei->vfs_inode;
}
-static void qnx4_destroy_inode(struct inode *inode)
+static void qnx4_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode));
}
+static void qnx4_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, qnx4_i_callback);
+}
+
static void init_once(void *foo)
{
struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo;
return &ei->vfs_inode;
}
-static void reiserfs_destroy_inode(struct inode *inode)
+static void reiserfs_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(reiserfs_inode_cachep, REISERFS_I(inode));
}
+static void reiserfs_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, reiserfs_i_callback);
+}
+
static void init_once(void *foo)
{
struct reiserfs_inode_info *ei = (struct reiserfs_inode_info *)foo;
return err;
}
-static int reiserfs_check_acl(struct inode *inode, int mask)
+static int reiserfs_check_acl(struct inode *inode, int mask, unsigned int flags)
{
struct posix_acl *acl;
int error = -EAGAIN; /* do regular unix permission checks by default */
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
+
acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
if (acl) {
return 0;
}
-int reiserfs_permission(struct inode *inode, int mask)
+int reiserfs_permission(struct inode *inode, int mask, unsigned int flags)
{
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
/*
* We don't do permission checks on the internal objects.
* Permissions are determined by the "owning" object.
* Stat data v1 doesn't support ACLs.
*/
if (get_inode_sd_version(inode) != STAT_DATA_V1)
- return generic_permission(inode, mask, reiserfs_check_acl);
+ return generic_permission(inode, mask, flags,
+ reiserfs_check_acl);
#endif
- return generic_permission(inode, mask, NULL);
+ return generic_permission(inode, mask, flags, NULL);
}
static int xattr_hide_revalidate(struct dentry *dentry, struct nameidata *nd)
{
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
return -EPERM;
}
strlen(PRIVROOT_NAME));
if (!IS_ERR(dentry)) {
REISERFS_SB(s)->priv_root = dentry;
- dentry->d_op = &xattr_lookup_poison_ops;
+ d_set_d_op(dentry, &xattr_lookup_poison_ops);
if (dentry->d_inode)
dentry->d_inode->i_flags |= S_PRIVATE;
} else
/*
* return a spent inode to the slab cache
*/
-static void romfs_destroy_inode(struct inode *inode)
+static void romfs_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(romfs_inode_cachep, ROMFS_I(inode));
}
+static void romfs_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, romfs_i_callback);
+}
+
/*
* get filesystem statistics
*/
}
-static void squashfs_destroy_inode(struct inode *inode)
+static void squashfs_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(squashfs_inode_cachep, squashfs_i(inode));
}
+static void squashfs_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, squashfs_i_callback);
+}
+
static struct file_system_type squashfs_fs_type = {
.owner = THIS_MODULE,
#include <linux/idr.h>
#include <linux/mutex.h>
#include <linux/backing-dev.h>
+#include <linux/rculist_bl.h>
#include "internal.h"
INIT_LIST_HEAD(&s->s_files);
#endif
INIT_LIST_HEAD(&s->s_instances);
- INIT_HLIST_HEAD(&s->s_anon);
+ INIT_HLIST_BL_HEAD(&s->s_anon);
INIT_LIST_HEAD(&s->s_inodes);
INIT_LIST_HEAD(&s->s_dentry_lru);
init_rwsem(&s->s_umount);
return mnt;
err:
- mntput(mnt);
+ mntput_long(mnt);
return ERR_PTR(err);
}
goto repeat;
}
-static int sysfs_dentry_delete(struct dentry *dentry)
+static int sysfs_dentry_delete(const struct dentry *dentry)
{
struct sysfs_dirent *sd = dentry->d_fsdata;
return !!(sd->s_flags & SYSFS_FLAG_REMOVED);
static int sysfs_dentry_revalidate(struct dentry *dentry, struct nameidata *nd)
{
- struct sysfs_dirent *sd = dentry->d_fsdata;
+ struct sysfs_dirent *sd;
int is_dir;
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ sd = dentry->d_fsdata;
mutex_lock(&sysfs_mutex);
/* The sysfs dirent has been deleted */
/* instantiate and hash dentry */
ret = d_find_alias(inode);
if (!ret) {
- dentry->d_op = &sysfs_dentry_ops;
+ d_set_d_op(dentry, &sysfs_dentry_ops);
dentry->d_fsdata = sysfs_get(sd);
d_add(dentry, inode);
} else {
return -ENOENT;
}
-int sysfs_permission(struct inode *inode, int mask)
+int sysfs_permission(struct inode *inode, int mask, unsigned int flags)
{
- struct sysfs_dirent *sd = inode->i_private;
+ struct sysfs_dirent *sd;
+
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
+
+ sd = inode->i_private;
mutex_lock(&sysfs_mutex);
sysfs_refresh_inode(sd, inode);
mutex_unlock(&sysfs_mutex);
- return generic_permission(inode, mask, NULL);
+ return generic_permission(inode, mask, flags, NULL);
}
struct inode *sysfs_get_inode(struct super_block *sb, struct sysfs_dirent *sd);
void sysfs_evict_inode(struct inode *inode);
int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr *iattr);
-int sysfs_permission(struct inode *inode, int mask);
+int sysfs_permission(struct inode *inode, int mask, unsigned int flags);
int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat);
int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
return &si->vfs_inode;
}
-static void sysv_destroy_inode(struct inode *inode)
+static void sysv_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
}
+static void sysv_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, sysv_i_callback);
+}
+
static void init_once(void *p)
{
struct sysv_inode_info *si = (struct sysv_inode_info *)p;
return err;
}
-static int sysv_hash(struct dentry *dentry, struct qstr *qstr)
+static int sysv_hash(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *qstr)
{
/* Truncate the name in place, avoids having to define a compare
function. */
struct inode * inode = NULL;
ino_t ino;
- dentry->d_op = dir->i_sb->s_root->d_op;
+ d_set_d_op(dentry, dir->i_sb->s_root->d_op);
if (dentry->d_name.len > SYSV_NAMELEN)
return ERR_PTR(-ENAMETOOLONG);
ino = sysv_inode_by_name(dentry);
if (sbi->s_forced_ro)
sb->s_flags |= MS_RDONLY;
if (sbi->s_truncate)
- sb->s_root->d_op = &sysv_dentry_operations;
+ d_set_d_op(sb->s_root, &sysv_dentry_operations);
return 1;
}
return &ui->vfs_inode;
};
+static void ubifs_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ struct ubifs_inode *ui = ubifs_inode(inode);
+ INIT_LIST_HEAD(&inode->i_dentry);
+ kmem_cache_free(ubifs_inode_slab, ui);
+}
+
static void ubifs_destroy_inode(struct inode *inode)
{
struct ubifs_inode *ui = ubifs_inode(inode);
kfree(ui->data);
- kmem_cache_free(ubifs_inode_slab, inode);
+ call_rcu(&inode->i_rcu, ubifs_i_callback);
}
/*
return &ei->vfs_inode;
}
-static void udf_destroy_inode(struct inode *inode)
+static void udf_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(udf_inode_cachep, UDF_I(inode));
}
+static void udf_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, udf_i_callback);
+}
+
static void init_once(void *foo)
{
struct udf_inode_info *ei = (struct udf_inode_info *)foo;
return &ei->vfs_inode;
}
-static void ufs_destroy_inode(struct inode *inode)
+static void ufs_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(ufs_inode_cachep, UFS_I(inode));
}
+static void ufs_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, ufs_i_callback);
+}
+
static void init_once(void *foo)
{
struct ufs_inode_info *ei = (struct ufs_inode_info *) foo;
}
int
-xfs_check_acl(struct inode *inode, int mask)
+xfs_check_acl(struct inode *inode, int mask, unsigned int flags)
{
- struct xfs_inode *ip = XFS_I(inode);
+ struct xfs_inode *ip;
struct posix_acl *acl;
int error = -EAGAIN;
+ ip = XFS_I(inode);
trace_xfs_check_acl(ip);
/*
if (!XFS_IFORK_Q(ip))
return -EAGAIN;
+ if (flags & IPERM_FLAG_RCU) {
+ if (!negative_cached_acl(inode, ACL_TYPE_ACCESS))
+ return -ECHILD;
+ return -EAGAIN;
+ }
+
acl = xfs_get_acl(inode, ACL_TYPE_ACCESS);
if (IS_ERR(acl))
return PTR_ERR(acl);
#define SGI_ACL_DEFAULT_SIZE (sizeof(SGI_ACL_DEFAULT)-1)
#ifdef CONFIG_XFS_POSIX_ACL
-extern int xfs_check_acl(struct inode *inode, int mask);
+extern int xfs_check_acl(struct inode *inode, int mask, unsigned int flags);
extern struct posix_acl *xfs_get_acl(struct inode *inode, int type);
extern int xfs_inherit_acl(struct inode *inode, struct posix_acl *default_acl);
extern int xfs_acl_chmod(struct inode *inode);
return ip;
}
+STATIC void
+xfs_inode_free_callback(
+ struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ struct xfs_inode *ip = XFS_I(inode);
+
+ INIT_LIST_HEAD(&inode->i_dentry);
+ kmem_zone_free(xfs_inode_zone, ip);
+}
+
void
xfs_inode_free(
struct xfs_inode *ip)
ASSERT(!spin_is_locked(&ip->i_flags_lock));
ASSERT(completion_done(&ip->i_flush));
- kmem_zone_free(xfs_inode_zone, ip);
+ call_rcu(&ip->i_vnode.i_rcu, xfs_inode_free_callback);
}
/*
#ifndef __LINUX_BIT_SPINLOCK_H
#define __LINUX_BIT_SPINLOCK_H
+#include <linux/kernel.h>
+#include <linux/preempt.h>
+#include <asm/atomic.h>
+
/*
* bit-based spin_lock()
*
/* operations shared over more than one file */
int coda_open(struct inode *i, struct file *f);
int coda_release(struct inode *i, struct file *f);
-int coda_permission(struct inode *inode, int mask);
+int coda_permission(struct inode *inode, int mask, unsigned int flags);
int coda_revalidate_inode(struct dentry *);
int coda_getattr(struct vfsmount *, struct dentry *, struct kstat *);
int coda_setattr(struct dentry *, struct iattr *);
#include <asm/atomic.h>
#include <linux/list.h>
#include <linux/rculist.h>
+#include <linux/rculist_bl.h>
#include <linux/spinlock.h>
+#include <linux/seqlock.h>
#include <linux/cache.h>
#include <linux/rcupdate.h>
};
extern struct dentry_stat_t dentry_stat;
+/*
+ * Compare 2 name strings, return 0 if they match, otherwise non-zero.
+ * The strings are both count bytes long, and count is non-zero.
+ */
+static inline int dentry_cmp(const unsigned char *cs, size_t scount,
+ const unsigned char *ct, size_t tcount)
+{
+ int ret;
+ if (scount != tcount)
+ return 1;
+ do {
+ ret = (*cs != *ct);
+ if (ret)
+ break;
+ cs++;
+ ct++;
+ tcount--;
+ } while (tcount);
+ return ret;
+}
+
/* Name hashing routines. Initial hash value */
/* Hash courtesy of the R5 hash in reiserfs modulo sign bits */
#define init_name_hash() 0
* large memory footprint increase).
*/
#ifdef CONFIG_64BIT
-#define DNAME_INLINE_LEN_MIN 32 /* 192 bytes */
+# define DNAME_INLINE_LEN 32 /* 192 bytes */
#else
-#define DNAME_INLINE_LEN_MIN 40 /* 128 bytes */
+# ifdef CONFIG_SMP
+# define DNAME_INLINE_LEN 36 /* 128 bytes */
+# else
+# define DNAME_INLINE_LEN 40 /* 128 bytes */
+# endif
#endif
struct dentry {
- atomic_t d_count;
+ /* RCU lookup touched fields */
unsigned int d_flags; /* protected by d_lock */
- spinlock_t d_lock; /* per dentry lock */
- int d_mounted;
- struct inode *d_inode; /* Where the name belongs to - NULL is
- * negative */
- /*
- * The next three fields are touched by __d_lookup. Place them here
- * so they all fit in a cache line.
- */
- struct hlist_node d_hash; /* lookup hash list */
+ seqcount_t d_seq; /* per dentry seqlock */
+ struct hlist_bl_node d_hash; /* lookup hash list */
struct dentry *d_parent; /* parent directory */
struct qstr d_name;
+ struct inode *d_inode; /* Where the name belongs to - NULL is
+ * negative */
+ unsigned char d_iname[DNAME_INLINE_LEN]; /* small names */
+
+ /* Ref lookup also touches following */
+ unsigned int d_count; /* protected by d_lock */
+ spinlock_t d_lock; /* per dentry lock */
+ const struct dentry_operations *d_op;
+ struct super_block *d_sb; /* The root of the dentry tree */
+ unsigned long d_time; /* used by d_revalidate */
+ void *d_fsdata; /* fs-specific data */
struct list_head d_lru; /* LRU list */
/*
} d_u;
struct list_head d_subdirs; /* our children */
struct list_head d_alias; /* inode alias list */
- unsigned long d_time; /* used by d_revalidate */
- const struct dentry_operations *d_op;
- struct super_block *d_sb; /* The root of the dentry tree */
- void *d_fsdata; /* fs-specific data */
-
- unsigned char d_iname[DNAME_INLINE_LEN_MIN]; /* small names */
};
/*
struct dentry_operations {
int (*d_revalidate)(struct dentry *, struct nameidata *);
- int (*d_hash) (struct dentry *, struct qstr *);
- int (*d_compare) (struct dentry *, struct qstr *, struct qstr *);
- int (*d_delete)(struct dentry *);
+ int (*d_hash)(const struct dentry *, const struct inode *,
+ struct qstr *);
+ int (*d_compare)(const struct dentry *, const struct inode *,
+ const struct dentry *, const struct inode *,
+ unsigned int, const char *, const struct qstr *);
+ int (*d_delete)(const struct dentry *);
void (*d_release)(struct dentry *);
void (*d_iput)(struct dentry *, struct inode *);
char *(*d_dname)(struct dentry *, char *, int);
-};
-
-/* the dentry parameter passed to d_hash and d_compare is the parent
- * directory of the entries to be compared. It is used in case these
- * functions need any directory specific information for determining
- * equivalency classes. Using the dentry itself might not work, as it
- * might be a negative dentry which has no information associated with
- * it */
+} ____cacheline_aligned;
/*
-locking rules:
- big lock dcache_lock d_lock may block
-d_revalidate: no no no yes
-d_hash no no no yes
-d_compare: no yes yes no
-d_delete: no yes no no
-d_release: no no no yes
-d_iput: no no no yes
+ * Locking rules for dentry_operations callbacks are to be found in
+ * Documentation/filesystems/Locking. Keep it updated!
+ *
+ * FUrther descriptions are found in Documentation/filesystems/vfs.txt.
+ * Keep it updated too!
*/
/* d_flags entries */
#define DCACHE_AUTOFS_PENDING 0x0001 /* autofs: "under construction" */
-#define DCACHE_NFSFS_RENAMED 0x0002 /* this dentry has been "silly
- * renamed" and has to be
- * deleted on the last dput()
- */
-#define DCACHE_DISCONNECTED 0x0004
- /* This dentry is possibly not currently connected to the dcache tree,
- * in which case its parent will either be itself, or will have this
- * flag as well. nfsd will not use a dentry with this bit set, but will
- * first endeavour to clear the bit either by discovering that it is
- * connected, or by performing lookup operations. Any filesystem which
- * supports nfsd_operations MUST have a lookup function which, if it finds
- * a directory inode with a DCACHE_DISCONNECTED dentry, will d_move
- * that dentry into place and return that dentry rather than the passed one,
- * typically using d_splice_alias.
- */
+#define DCACHE_NFSFS_RENAMED 0x0002
+ /* this dentry has been "silly renamed" and has to be deleted on the last
+ * dput() */
+
+#define DCACHE_DISCONNECTED 0x0004
+ /* This dentry is possibly not currently connected to the dcache tree, in
+ * which case its parent will either be itself, or will have this flag as
+ * well. nfsd will not use a dentry with this bit set, but will first
+ * endeavour to clear the bit either by discovering that it is connected,
+ * or by performing lookup operations. Any filesystem which supports
+ * nfsd_operations MUST have a lookup function which, if it finds a
+ * directory inode with a DCACHE_DISCONNECTED dentry, will d_move that
+ * dentry into place and return that dentry rather than the passed one,
+ * typically using d_splice_alias. */
#define DCACHE_REFERENCED 0x0008 /* Recently used, don't discard. */
#define DCACHE_UNHASHED 0x0010
-
-#define DCACHE_INOTIFY_PARENT_WATCHED 0x0020 /* Parent inode is watched by inotify */
+#define DCACHE_INOTIFY_PARENT_WATCHED 0x0020
+ /* Parent inode is watched by inotify */
#define DCACHE_COOKIE 0x0040 /* For use by dcookie subsystem */
-
-#define DCACHE_FSNOTIFY_PARENT_WATCHED 0x0080 /* Parent inode is watched by some fsnotify listener */
+#define DCACHE_FSNOTIFY_PARENT_WATCHED 0x0080
+ /* Parent inode is watched by some fsnotify listener */
#define DCACHE_CANT_MOUNT 0x0100
+#define DCACHE_GENOCIDE 0x0200
+#define DCACHE_MOUNTED 0x0400 /* is a mountpoint */
-extern spinlock_t dcache_lock;
-extern seqlock_t rename_lock;
-
-/**
- * d_drop - drop a dentry
- * @dentry: dentry to drop
- *
- * d_drop() unhashes the entry from the parent dentry hashes, so that it won't
- * be found through a VFS lookup any more. Note that this is different from
- * deleting the dentry - d_delete will try to mark the dentry negative if
- * possible, giving a successful _negative_ lookup, while d_drop will
- * just make the cache lookup fail.
- *
- * d_drop() is used mainly for stuff that wants to invalidate a dentry for some
- * reason (NFS timeouts or autofs deletes).
- *
- * __d_drop requires dentry->d_lock.
- */
-
-static inline void __d_drop(struct dentry *dentry)
-{
- if (!(dentry->d_flags & DCACHE_UNHASHED)) {
- dentry->d_flags |= DCACHE_UNHASHED;
- hlist_del_rcu(&dentry->d_hash);
- }
-}
+#define DCACHE_OP_HASH 0x1000
+#define DCACHE_OP_COMPARE 0x2000
+#define DCACHE_OP_REVALIDATE 0x4000
+#define DCACHE_OP_DELETE 0x8000
-static inline void d_drop(struct dentry *dentry)
-{
- spin_lock(&dcache_lock);
- spin_lock(&dentry->d_lock);
- __d_drop(dentry);
- spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
-}
+extern seqlock_t rename_lock;
static inline int dname_external(struct dentry *dentry)
{
extern void d_instantiate(struct dentry *, struct inode *);
extern struct dentry * d_instantiate_unique(struct dentry *, struct inode *);
extern struct dentry * d_materialise_unique(struct dentry *, struct inode *);
+extern void __d_drop(struct dentry *dentry);
+extern void d_drop(struct dentry *dentry);
extern void d_delete(struct dentry *);
+extern void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op);
/* allocate/de-allocate */
extern struct dentry * d_alloc(struct dentry *, const struct qstr *);
+extern struct dentry * d_alloc_pseudo(struct super_block *, const struct qstr *);
extern struct dentry * d_splice_alias(struct inode *, struct dentry *);
extern struct dentry * d_add_ci(struct dentry *, struct inode *, struct qstr *);
extern struct dentry * d_obtain_alias(struct inode *);
return res;
}
+extern void dentry_update_name_case(struct dentry *, struct qstr *);
+
/* used for rename() and baskets */
extern void d_move(struct dentry *, struct dentry *);
extern struct dentry *d_ancestor(struct dentry *, struct dentry *);
/* appendix may either be NULL or be used for transname suffixes */
-extern struct dentry * d_lookup(struct dentry *, struct qstr *);
-extern struct dentry * __d_lookup(struct dentry *, struct qstr *);
-extern struct dentry * d_hash_and_lookup(struct dentry *, struct qstr *);
+extern struct dentry *d_lookup(struct dentry *, struct qstr *);
+extern struct dentry *d_hash_and_lookup(struct dentry *, struct qstr *);
+extern struct dentry *__d_lookup(struct dentry *, struct qstr *);
+extern struct dentry *__d_lookup_rcu(struct dentry *parent, struct qstr *name,
+ unsigned *seq, struct inode **inode);
+
+/**
+ * __d_rcu_to_refcount - take a refcount on dentry if sequence check is ok
+ * @dentry: dentry to take a ref on
+ * @seq: seqcount to verify against
+ * @Returns: 0 on failure, else 1.
+ *
+ * __d_rcu_to_refcount operates on a dentry,seq pair that was returned
+ * by __d_lookup_rcu, to get a reference on an rcu-walk dentry.
+ */
+static inline int __d_rcu_to_refcount(struct dentry *dentry, unsigned seq)
+{
+ int ret = 0;
+
+ assert_spin_locked(&dentry->d_lock);
+ if (!read_seqcount_retry(&dentry->d_seq, seq)) {
+ ret = 1;
+ dentry->d_count++;
+ }
+
+ return ret;
+}
/* validate "insecure" dentry pointer */
extern int d_validate(struct dentry *, struct dentry *);
extern char *__d_path(const struct path *path, struct path *root, char *, int);
extern char *d_path(const struct path *, char *, int);
extern char *d_path_with_unreachable(const struct path *, char *, int);
-extern char *__dentry_path(struct dentry *, char *, int);
+extern char *dentry_path_raw(struct dentry *, char *, int);
extern char *dentry_path(struct dentry *, char *, int);
/* Allocation counts.. */
/**
- * dget, dget_locked - get a reference to a dentry
+ * dget, dget_dlock - get a reference to a dentry
* @dentry: dentry to get a reference to
*
* Given a dentry or %NULL pointer increment the reference count
* if appropriate and return the dentry. A dentry will not be
- * destroyed when it has references. dget() should never be
- * called for dentries with zero reference counter. For these cases
- * (preferably none, functions in dcache.c are sufficient for normal
- * needs and they take necessary precautions) you should hold dcache_lock
- * and call dget_locked() instead of dget().
+ * destroyed when it has references.
*/
-
+static inline struct dentry *dget_dlock(struct dentry *dentry)
+{
+ if (dentry)
+ dentry->d_count++;
+ return dentry;
+}
+
static inline struct dentry *dget(struct dentry *dentry)
{
if (dentry) {
- BUG_ON(!atomic_read(&dentry->d_count));
- atomic_inc(&dentry->d_count);
+ spin_lock(&dentry->d_lock);
+ dget_dlock(dentry);
+ spin_unlock(&dentry->d_lock);
}
return dentry;
}
-extern struct dentry * dget_locked(struct dentry *);
+extern struct dentry *dget_parent(struct dentry *dentry);
/**
* d_unhashed - is dentry hashed
spin_unlock(&dentry->d_lock);
}
-static inline struct dentry *dget_parent(struct dentry *dentry)
-{
- struct dentry *ret;
-
- spin_lock(&dentry->d_lock);
- ret = dget(dentry->d_parent);
- spin_unlock(&dentry->d_lock);
- return ret;
-}
-
extern void dput(struct dentry *);
static inline int d_mountpoint(struct dentry *dentry)
{
- return dentry->d_mounted;
+ return dentry->d_flags & DCACHE_MOUNTED;
}
extern struct vfsmount *lookup_mnt(struct path *);
#include <linux/capability.h>
#include <linux/semaphore.h>
#include <linux/fiemap.h>
+#include <linux/rculist_bl.h>
#include <asm/atomic.h>
#include <asm/byteorder.h>
#define ACL_NOT_CACHED ((void *)(-1))
struct inode {
+ /* RCU path lookup touches following: */
+ umode_t i_mode;
+ uid_t i_uid;
+ gid_t i_gid;
+ const struct inode_operations *i_op;
+ struct super_block *i_sb;
+
+ spinlock_t i_lock; /* i_blocks, i_bytes, maybe i_size */
+ unsigned int i_flags;
+ struct mutex i_mutex;
+
+ unsigned long i_state;
+ unsigned long dirtied_when; /* jiffies of first dirtying */
+
struct hlist_node i_hash;
struct list_head i_wb_list; /* backing dev IO list */
struct list_head i_lru; /* inode LRU list */
struct list_head i_sb_list;
- struct list_head i_dentry;
+ union {
+ struct list_head i_dentry;
+ struct rcu_head i_rcu;
+ };
unsigned long i_ino;
atomic_t i_count;
unsigned int i_nlink;
- uid_t i_uid;
- gid_t i_gid;
dev_t i_rdev;
unsigned int i_blkbits;
u64 i_version;
struct timespec i_ctime;
blkcnt_t i_blocks;
unsigned short i_bytes;
- umode_t i_mode;
- spinlock_t i_lock; /* i_blocks, i_bytes, maybe i_size */
- struct mutex i_mutex;
struct rw_semaphore i_alloc_sem;
- const struct inode_operations *i_op;
const struct file_operations *i_fop; /* former ->i_op->default_file_ops */
- struct super_block *i_sb;
struct file_lock *i_flock;
struct address_space *i_mapping;
struct address_space i_data;
struct hlist_head i_fsnotify_marks;
#endif
- unsigned long i_state;
- unsigned long dirtied_when; /* jiffies of first dirtying */
-
- unsigned int i_flags;
-
#ifdef CONFIG_IMA
/* protected by i_lock */
unsigned int i_readcount; /* struct files open RO */
const struct xattr_handler **s_xattr;
struct list_head s_inodes; /* all inodes */
- struct hlist_head s_anon; /* anonymous dentries for (nfs) exporting */
+ struct hlist_bl_head s_anon; /* anonymous dentries for (nfs) exporting */
#ifdef CONFIG_SMP
struct list_head __percpu *s_files;
#else
struct list_head s_files;
#endif
- /* s_dentry_lru and s_nr_dentry_unused are protected by dcache_lock */
+ /* s_dentry_lru, s_nr_dentry_unused protected by dcache.c lru locks */
struct list_head s_dentry_lru; /* unused dentry lru */
int s_nr_dentry_unused; /* # of dentry on lru */
int (*setlease)(struct file *, long, struct file_lock **);
};
+#define IPERM_FLAG_RCU 0x0001
+
struct inode_operations {
- int (*create) (struct inode *,struct dentry *,int, struct nameidata *);
struct dentry * (*lookup) (struct inode *,struct dentry *, struct nameidata *);
+ void * (*follow_link) (struct dentry *, struct nameidata *);
+ int (*permission) (struct inode *, int, unsigned int);
+ int (*check_acl)(struct inode *, int, unsigned int);
+
+ int (*readlink) (struct dentry *, char __user *,int);
+ void (*put_link) (struct dentry *, struct nameidata *, void *);
+
+ int (*create) (struct inode *,struct dentry *,int, struct nameidata *);
int (*link) (struct dentry *,struct inode *,struct dentry *);
int (*unlink) (struct inode *,struct dentry *);
int (*symlink) (struct inode *,struct dentry *,const char *);
int (*mknod) (struct inode *,struct dentry *,int,dev_t);
int (*rename) (struct inode *, struct dentry *,
struct inode *, struct dentry *);
- int (*readlink) (struct dentry *, char __user *,int);
- void * (*follow_link) (struct dentry *, struct nameidata *);
- void (*put_link) (struct dentry *, struct nameidata *, void *);
void (*truncate) (struct inode *);
- int (*permission) (struct inode *, int);
- int (*check_acl)(struct inode *, int);
int (*setattr) (struct dentry *, struct iattr *);
int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *);
int (*setxattr) (struct dentry *, const char *,const void *,size_t,int);
loff_t len);
int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
u64 len);
-};
+} ____cacheline_aligned;
struct seq_file;
#endif
extern int notify_change(struct dentry *, struct iattr *);
extern int inode_permission(struct inode *, int);
-extern int generic_permission(struct inode *, int,
- int (*check_acl)(struct inode *, int));
+extern int generic_permission(struct inode *, int, unsigned int,
+ int (*check_acl)(struct inode *, int, unsigned int));
static inline bool execute_ok(struct inode *inode)
{
extern void end_writeback(struct inode *);
extern void __destroy_inode(struct inode *);
extern struct inode *new_inode(struct super_block *);
+extern void free_inode_nonrcu(struct inode *inode);
extern int should_remove_suid(struct dentry *);
extern int file_remove_suid(struct file *);
{
ino_t res;
+ /*
+ * Don't strictly need d_lock here? If the parent ino could change
+ * then surely we'd have a deeper race in the caller?
+ */
spin_lock(&dentry->d_lock);
res = dentry->d_parent->d_inode->i_ino;
spin_unlock(&dentry->d_lock);
#define _LINUX_FS_STRUCT_H
#include <linux/path.h>
+#include <linux/spinlock.h>
+#include <linux/seqlock.h>
struct fs_struct {
int users;
spinlock_t lock;
+ seqcount_t seq;
int umask;
int in_exec;
struct path root, pwd;
/*
* fsnotify_d_instantiate - instantiate a dentry for inode
- * Called with dcache_lock held.
*/
static inline void fsnotify_d_instantiate(struct dentry *dentry,
struct inode *inode)
/*
* fsnotify_d_move - dentry has been moved
- * Called with dcache_lock and dentry->d_lock held.
*/
static inline void fsnotify_d_move(struct dentry *dentry)
{
{
struct dentry *parent;
- assert_spin_locked(&dcache_lock);
assert_spin_locked(&dentry->d_lock);
+ /*
+ * Serialisation of setting PARENT_WATCHED on the dentries is provided
+ * by d_lock. If inotify_inode_watched changes after we have taken
+ * d_lock, the following __fsnotify_update_child_dentry_flags call will
+ * find our entry, so it will spin until we complete here, and update
+ * us with the new state.
+ */
parent = dentry->d_parent;
if (parent->d_inode && fsnotify_inode_watches_children(parent->d_inode))
dentry->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED;
/*
* fsnotify_d_instantiate - instantiate a dentry for inode
- * Called with dcache_lock held.
*/
static inline void __fsnotify_d_instantiate(struct dentry *dentry, struct inode *inode)
{
if (!inode)
return;
- assert_spin_locked(&dcache_lock);
-
spin_lock(&dentry->d_lock);
__fsnotify_update_dcache_flags(dentry);
spin_unlock(&dentry->d_lock);
int generic_acl_init(struct inode *, struct inode *);
int generic_acl_chmod(struct inode *);
-int generic_check_acl(struct inode *inode, int mask);
+int generic_check_acl(struct inode *inode, int mask, unsigned int flags);
#endif /* LINUX_GENERIC_ACL_H */
--- /dev/null
+#ifndef _LINUX_LIST_BL_H
+#define _LINUX_LIST_BL_H
+
+#include <linux/list.h>
+
+/*
+ * Special version of lists, where head of the list has a lock in the lowest
+ * bit. This is useful for scalable hash tables without increasing memory
+ * footprint overhead.
+ *
+ * For modification operations, the 0 bit of hlist_bl_head->first
+ * pointer must be set.
+ *
+ * With some small modifications, this can easily be adapted to store several
+ * arbitrary bits (not just a single lock bit), if the need arises to store
+ * some fast and compact auxiliary data.
+ */
+
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+#define LIST_BL_LOCKMASK 1UL
+#else
+#define LIST_BL_LOCKMASK 0UL
+#endif
+
+#ifdef CONFIG_DEBUG_LIST
+#define LIST_BL_BUG_ON(x) BUG_ON(x)
+#else
+#define LIST_BL_BUG_ON(x)
+#endif
+
+
+struct hlist_bl_head {
+ struct hlist_bl_node *first;
+};
+
+struct hlist_bl_node {
+ struct hlist_bl_node *next, **pprev;
+};
+#define INIT_HLIST_BL_HEAD(ptr) \
+ ((ptr)->first = NULL)
+
+static inline void INIT_HLIST_BL_NODE(struct hlist_bl_node *h)
+{
+ h->next = NULL;
+ h->pprev = NULL;
+}
+
+#define hlist_bl_entry(ptr, type, member) container_of(ptr,type,member)
+
+static inline int hlist_bl_unhashed(const struct hlist_bl_node *h)
+{
+ return !h->pprev;
+}
+
+static inline struct hlist_bl_node *hlist_bl_first(struct hlist_bl_head *h)
+{
+ return (struct hlist_bl_node *)
+ ((unsigned long)h->first & ~LIST_BL_LOCKMASK);
+}
+
+static inline void hlist_bl_set_first(struct hlist_bl_head *h,
+ struct hlist_bl_node *n)
+{
+ LIST_BL_BUG_ON((unsigned long)n & LIST_BL_LOCKMASK);
+ LIST_BL_BUG_ON(!((unsigned long)h->first & LIST_BL_LOCKMASK));
+ h->first = (struct hlist_bl_node *)((unsigned long)n | LIST_BL_LOCKMASK);
+}
+
+static inline int hlist_bl_empty(const struct hlist_bl_head *h)
+{
+ return !((unsigned long)h->first & ~LIST_BL_LOCKMASK);
+}
+
+static inline void hlist_bl_add_head(struct hlist_bl_node *n,
+ struct hlist_bl_head *h)
+{
+ struct hlist_bl_node *first = hlist_bl_first(h);
+
+ n->next = first;
+ if (first)
+ first->pprev = &n->next;
+ n->pprev = &h->first;
+ hlist_bl_set_first(h, n);
+}
+
+static inline void __hlist_bl_del(struct hlist_bl_node *n)
+{
+ struct hlist_bl_node *next = n->next;
+ struct hlist_bl_node **pprev = n->pprev;
+
+ LIST_BL_BUG_ON((unsigned long)n & LIST_BL_LOCKMASK);
+
+ /* pprev may be `first`, so be careful not to lose the lock bit */
+ *pprev = (struct hlist_bl_node *)
+ ((unsigned long)next |
+ ((unsigned long)*pprev & LIST_BL_LOCKMASK));
+ if (next)
+ next->pprev = pprev;
+}
+
+static inline void hlist_bl_del(struct hlist_bl_node *n)
+{
+ __hlist_bl_del(n);
+ n->next = LIST_POISON1;
+ n->pprev = LIST_POISON2;
+}
+
+static inline void hlist_bl_del_init(struct hlist_bl_node *n)
+{
+ if (!hlist_bl_unhashed(n)) {
+ __hlist_bl_del(n);
+ INIT_HLIST_BL_NODE(n);
+ }
+}
+
+/**
+ * hlist_bl_for_each_entry - iterate over list of given type
+ * @tpos: the type * to use as a loop cursor.
+ * @pos: the &struct hlist_node to use as a loop cursor.
+ * @head: the head for your list.
+ * @member: the name of the hlist_node within the struct.
+ *
+ */
+#define hlist_bl_for_each_entry(tpos, pos, head, member) \
+ for (pos = hlist_bl_first(head); \
+ pos && \
+ ({ tpos = hlist_bl_entry(pos, typeof(*tpos), member); 1;}); \
+ pos = pos->next)
+
+/**
+ * hlist_bl_for_each_entry_safe - iterate over list of given type safe against removal of list entry
+ * @tpos: the type * to use as a loop cursor.
+ * @pos: the &struct hlist_node to use as a loop cursor.
+ * @n: another &struct hlist_node to use as temporary storage
+ * @head: the head for your list.
+ * @member: the name of the hlist_node within the struct.
+ */
+#define hlist_bl_for_each_entry_safe(tpos, pos, n, head, member) \
+ for (pos = hlist_bl_first(head); \
+ pos && ({ n = pos->next; 1; }) && \
+ ({ tpos = hlist_bl_entry(pos, typeof(*tpos), member); 1;}); \
+ pos = n)
+
+#endif
#include <linux/list.h>
#include <linux/nodemask.h>
#include <linux/spinlock.h>
+#include <linux/seqlock.h>
#include <asm/atomic.h>
struct super_block;
#define MNT_INTERNAL 0x4000
+struct mnt_pcp {
+ int mnt_count;
+ int mnt_writers;
+};
+
struct vfsmount {
struct list_head mnt_hash;
struct vfsmount *mnt_parent; /* fs we are mounted on */
struct dentry *mnt_mountpoint; /* dentry of mountpoint */
struct dentry *mnt_root; /* root of the mounted tree */
struct super_block *mnt_sb; /* pointer to superblock */
+#ifdef CONFIG_SMP
+ struct mnt_pcp __percpu *mnt_pcp;
+ atomic_t mnt_longrefs;
+#else
+ int mnt_count;
+ int mnt_writers;
+#endif
struct list_head mnt_mounts; /* list of children, anchored here */
struct list_head mnt_child; /* and going through their mnt_child */
int mnt_flags;
struct mnt_namespace *mnt_ns; /* containing namespace */
int mnt_id; /* mount identifier */
int mnt_group_id; /* peer group identifier */
- /*
- * We put mnt_count & mnt_expiry_mark at the end of struct vfsmount
- * to let these frequently modified fields in a separate cache line
- * (so that reads of mnt_flags wont ping-pong on SMP machines)
- */
- atomic_t mnt_count;
int mnt_expiry_mark; /* true if marked for expiry */
int mnt_pinned;
int mnt_ghosts;
-#ifdef CONFIG_SMP
- int __percpu *mnt_writers;
-#else
- int mnt_writers;
-#endif
};
-static inline int *get_mnt_writers_ptr(struct vfsmount *mnt)
-{
-#ifdef CONFIG_SMP
- return mnt->mnt_writers;
-#else
- return &mnt->mnt_writers;
-#endif
-}
-
-static inline struct vfsmount *mntget(struct vfsmount *mnt)
-{
- if (mnt)
- atomic_inc(&mnt->mnt_count);
- return mnt;
-}
-
struct file; /* forward dec */
extern int mnt_want_write(struct vfsmount *mnt);
extern int mnt_want_write_file(struct file *file);
extern int mnt_clone_write(struct vfsmount *mnt);
extern void mnt_drop_write(struct vfsmount *mnt);
-extern void mntput_no_expire(struct vfsmount *mnt);
+extern void mntput(struct vfsmount *mnt);
+extern struct vfsmount *mntget(struct vfsmount *mnt);
+extern void mntput_long(struct vfsmount *mnt);
+extern struct vfsmount *mntget_long(struct vfsmount *mnt);
extern void mnt_pin(struct vfsmount *mnt);
extern void mnt_unpin(struct vfsmount *mnt);
extern int __mnt_is_readonly(struct vfsmount *mnt);
-static inline void mntput(struct vfsmount *mnt)
-{
- if (mnt) {
- mnt->mnt_expiry_mark = 0;
- mntput_no_expire(mnt);
- }
-}
-
extern struct vfsmount *do_kern_mount(const char *fstype, int flags,
const char *name, void *data);
struct path path;
struct qstr last;
struct path root;
+ struct file *file;
+ struct inode *inode; /* path.dentry.d_inode */
unsigned int flags;
+ unsigned seq;
int last_type;
unsigned depth;
char *saved_names[MAX_NESTED_LINKS + 1];
* - require a directory
* - ending slashes ok even for nonexistent files
* - internal "there are more path components" flag
- * - locked when lookup done with dcache_lock held
* - dentry cache is untrusted; force a real lookup
*/
-#define LOOKUP_FOLLOW 1
-#define LOOKUP_DIRECTORY 2
-#define LOOKUP_CONTINUE 4
-#define LOOKUP_PARENT 16
-#define LOOKUP_REVAL 64
+#define LOOKUP_FOLLOW 0x0001
+#define LOOKUP_DIRECTORY 0x0002
+#define LOOKUP_CONTINUE 0x0004
+
+#define LOOKUP_PARENT 0x0010
+#define LOOKUP_REVAL 0x0020
+#define LOOKUP_RCU 0x0040
/*
* Intent data
*/
__u8 file_handle[6];
};
-static inline struct ncp_server *NCP_SBP(struct super_block *sb)
+static inline struct ncp_server *NCP_SBP(const struct super_block *sb)
{
return sb->s_fs_info;
}
#define NCP_SERVER(inode) NCP_SBP((inode)->i_sb)
-static inline struct ncp_inode_info *NCP_FINFO(struct inode *inode)
+static inline struct ncp_inode_info *NCP_FINFO(const struct inode *inode)
{
return container_of(inode, struct ncp_inode_info, vfs_inode);
}
extern int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr);
extern int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr);
extern int nfs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
-extern int nfs_permission(struct inode *, int);
+extern int nfs_permission(struct inode *, int, unsigned int);
extern int nfs_open(struct inode *, struct file *);
extern int nfs_release(struct inode *, struct file *);
extern int nfs_attribute_timeout(struct inode *inode);
};
extern void path_get(struct path *);
+extern void path_get_long(struct path *);
extern void path_put(struct path *);
+extern void path_put_long(struct path *);
static inline int path_equal(const struct path *path1, const struct path *path2)
{
return acl;
}
+static inline int negative_cached_acl(struct inode *inode, int type)
+{
+ struct posix_acl **p, *acl;
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ p = &inode->i_acl;
+ break;
+ case ACL_TYPE_DEFAULT:
+ p = &inode->i_default_acl;
+ break;
+ default:
+ BUG();
+ }
+ acl = ACCESS_ONCE(*p);
+ if (acl)
+ return 0;
+ return 1;
+}
+
static inline void set_cached_acl(struct inode *inode,
int type,
struct posix_acl *acl)
--- /dev/null
+#ifndef _LINUX_RCULIST_BL_H
+#define _LINUX_RCULIST_BL_H
+
+/*
+ * RCU-protected bl list version. See include/linux/list_bl.h.
+ */
+#include <linux/list_bl.h>
+#include <linux/rcupdate.h>
+
+static inline void hlist_bl_set_first_rcu(struct hlist_bl_head *h,
+ struct hlist_bl_node *n)
+{
+ LIST_BL_BUG_ON((unsigned long)n & LIST_BL_LOCKMASK);
+ LIST_BL_BUG_ON(!((unsigned long)h->first & LIST_BL_LOCKMASK));
+ rcu_assign_pointer(h->first,
+ (struct hlist_bl_node *)((unsigned long)n | LIST_BL_LOCKMASK));
+}
+
+static inline struct hlist_bl_node *hlist_bl_first_rcu(struct hlist_bl_head *h)
+{
+ return (struct hlist_bl_node *)
+ ((unsigned long)rcu_dereference(h->first) & ~LIST_BL_LOCKMASK);
+}
+
+/**
+ * hlist_bl_del_init_rcu - deletes entry from hash list with re-initialization
+ * @n: the element to delete from the hash list.
+ *
+ * Note: hlist_bl_unhashed() on the node returns true after this. It is
+ * useful for RCU based read lockfree traversal if the writer side
+ * must know if the list entry is still hashed or already unhashed.
+ *
+ * In particular, it means that we can not poison the forward pointers
+ * that may still be used for walking the hash list and we can only
+ * zero the pprev pointer so list_unhashed() will return true after
+ * this.
+ *
+ * The caller must take whatever precautions are necessary (such as
+ * holding appropriate locks) to avoid racing with another
+ * list-mutation primitive, such as hlist_bl_add_head_rcu() or
+ * hlist_bl_del_rcu(), running on this same list. However, it is
+ * perfectly legal to run concurrently with the _rcu list-traversal
+ * primitives, such as hlist_bl_for_each_entry_rcu().
+ */
+static inline void hlist_bl_del_init_rcu(struct hlist_bl_node *n)
+{
+ if (!hlist_bl_unhashed(n)) {
+ __hlist_bl_del(n);
+ n->pprev = NULL;
+ }
+}
+
+/**
+ * hlist_bl_del_rcu - deletes entry from hash list without re-initialization
+ * @n: the element to delete from the hash list.
+ *
+ * Note: hlist_bl_unhashed() on entry does not return true after this,
+ * the entry is in an undefined state. It is useful for RCU based
+ * lockfree traversal.
+ *
+ * In particular, it means that we can not poison the forward
+ * pointers that may still be used for walking the hash list.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as hlist_bl_add_head_rcu()
+ * or hlist_bl_del_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * hlist_bl_for_each_entry().
+ */
+static inline void hlist_bl_del_rcu(struct hlist_bl_node *n)
+{
+ __hlist_bl_del(n);
+ n->pprev = LIST_POISON2;
+}
+
+/**
+ * hlist_bl_add_head_rcu
+ * @n: the element to add to the hash list.
+ * @h: the list to add to.
+ *
+ * Description:
+ * Adds the specified element to the specified hlist_bl,
+ * while permitting racing traversals.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as hlist_bl_add_head_rcu()
+ * or hlist_bl_del_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * hlist_bl_for_each_entry_rcu(), used to prevent memory-consistency
+ * problems on Alpha CPUs. Regardless of the type of CPU, the
+ * list-traversal primitive must be guarded by rcu_read_lock().
+ */
+static inline void hlist_bl_add_head_rcu(struct hlist_bl_node *n,
+ struct hlist_bl_head *h)
+{
+ struct hlist_bl_node *first;
+
+ /* don't need hlist_bl_first_rcu because we're under lock */
+ first = hlist_bl_first(h);
+
+ n->next = first;
+ if (first)
+ first->pprev = &n->next;
+ n->pprev = &h->first;
+
+ /* need _rcu because we can have concurrent lock free readers */
+ hlist_bl_set_first_rcu(h, n);
+}
+/**
+ * hlist_bl_for_each_entry_rcu - iterate over rcu list of given type
+ * @tpos: the type * to use as a loop cursor.
+ * @pos: the &struct hlist_bl_node to use as a loop cursor.
+ * @head: the head for your list.
+ * @member: the name of the hlist_bl_node within the struct.
+ *
+ */
+#define hlist_bl_for_each_entry_rcu(tpos, pos, head, member) \
+ for (pos = hlist_bl_first_rcu(head); \
+ pos && \
+ ({ tpos = hlist_bl_entry(pos, typeof(*tpos), member); 1; }); \
+ pos = rcu_dereference_raw(pos->next))
+
+#endif
int reiserfs_lookup_privroot(struct super_block *sb);
int reiserfs_delete_xattrs(struct inode *inode);
int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs);
-int reiserfs_permission(struct inode *inode, int mask);
+int reiserfs_permission(struct inode *inode, int mask, unsigned int flags);
#ifdef CONFIG_REISERFS_FS_XATTR
#define has_xattr_dir(inode) (REISERFS_I(inode)->i_flags & i_has_xattr_dir)
* called when the actual read/write operations are performed.
* @inode contains the inode structure to check.
* @mask contains the permission mask.
- * @nd contains the nameidata (may be NULL).
* Return 0 if permission is granted.
* @inode_setattr:
* Check permission before setting file attributes. Note that the kernel
int security_inode_readlink(struct dentry *dentry);
int security_inode_follow_link(struct dentry *dentry, struct nameidata *nd);
int security_inode_permission(struct inode *inode, int mask);
+int security_inode_exec_permission(struct inode *inode, unsigned int flags);
int security_inode_setattr(struct dentry *dentry, struct iattr *attr);
int security_inode_getattr(struct vfsmount *mnt, struct dentry *dentry);
int security_inode_setxattr(struct dentry *dentry, const char *name,
return 0;
}
+static inline int security_inode_exec_permission(struct inode *inode,
+ unsigned int flags)
+{
+ return 0;
+}
+
static inline int security_inode_setattr(struct dentry *dentry,
struct iattr *attr)
{
{
smp_rmb();
- return (sl->sequence != start);
+ return unlikely(sl->sequence != start);
}
#define SEQCNT_ZERO { 0 }
#define seqcount_init(x) do { *(x) = (seqcount_t) SEQCNT_ZERO; } while (0)
-/* Start of read using pointer to a sequence counter only. */
-static inline unsigned read_seqcount_begin(const seqcount_t *s)
+/**
+ * __read_seqcount_begin - begin a seq-read critical section (without barrier)
+ * @s: pointer to seqcount_t
+ * Returns: count to be passed to read_seqcount_retry
+ *
+ * __read_seqcount_begin is like read_seqcount_begin, but has no smp_rmb()
+ * barrier. Callers should ensure that smp_rmb() or equivalent ordering is
+ * provided before actually loading any of the variables that are to be
+ * protected in this critical section.
+ *
+ * Use carefully, only in critical code, and comment how the barrier is
+ * provided.
+ */
+static inline unsigned __read_seqcount_begin(const seqcount_t *s)
{
unsigned ret;
repeat:
ret = s->sequence;
- smp_rmb();
if (unlikely(ret & 1)) {
cpu_relax();
goto repeat;
return ret;
}
-/*
- * Test if reader processed invalid data because sequence number has changed.
+/**
+ * read_seqcount_begin - begin a seq-read critical section
+ * @s: pointer to seqcount_t
+ * Returns: count to be passed to read_seqcount_retry
+ *
+ * read_seqcount_begin opens a read critical section of the given seqcount.
+ * Validity of the critical section is tested by checking read_seqcount_retry
+ * function.
+ */
+static inline unsigned read_seqcount_begin(const seqcount_t *s)
+{
+ unsigned ret = __read_seqcount_begin(s);
+ smp_rmb();
+ return ret;
+}
+
+/**
+ * __read_seqcount_retry - end a seq-read critical section (without barrier)
+ * @s: pointer to seqcount_t
+ * @start: count, from read_seqcount_begin
+ * Returns: 1 if retry is required, else 0
+ *
+ * __read_seqcount_retry is like read_seqcount_retry, but has no smp_rmb()
+ * barrier. Callers should ensure that smp_rmb() or equivalent ordering is
+ * provided before actually loading any of the variables that are to be
+ * protected in this critical section.
+ *
+ * Use carefully, only in critical code, and comment how the barrier is
+ * provided.
+ */
+static inline int __read_seqcount_retry(const seqcount_t *s, unsigned start)
+{
+ return unlikely(s->sequence != start);
+}
+
+/**
+ * read_seqcount_retry - end a seq-read critical section
+ * @s: pointer to seqcount_t
+ * @start: count, from read_seqcount_begin
+ * Returns: 1 if retry is required, else 0
+ *
+ * read_seqcount_retry closes a read critical section of the given seqcount.
+ * If the critical section was invalid, it must be ignored (and typically
+ * retried).
*/
static inline int read_seqcount_retry(const seqcount_t *s, unsigned start)
{
smp_rmb();
- return s->sequence != start;
+ return __read_seqcount_retry(s, start);
}
s->sequence++;
}
+/**
+ * write_seqcount_barrier - invalidate in-progress read-side seq operations
+ * @s: pointer to seqcount_t
+ *
+ * After write_seqcount_barrier, no read-side seq operations will complete
+ * successfully and see data older than this.
+ */
+static inline void write_seqcount_barrier(seqcount_t *s)
+{
+ smp_wmb();
+ s->sequence+=2;
+}
+
/*
* Possible sw/hw IRQ protected versions of the interfaces.
*/
void kmem_cache_free(struct kmem_cache *, void *);
unsigned int kmem_cache_size(struct kmem_cache *);
const char *kmem_cache_name(struct kmem_cache *);
-int kern_ptr_validate(const void *ptr, unsigned long size);
-int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr);
/*
* Please use this macro to create slab caches. Simply specify the
return &ei->vfs_inode;
}
-static void mqueue_destroy_inode(struct inode *inode)
+static void mqueue_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode));
}
+static void mqueue_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, mqueue_i_callback);
+}
+
static void mqueue_evict_inode(struct inode *inode)
{
struct mqueue_inode_info *info;
* -> cgroup_mkdir.
*/
+static struct dentry *cgroup_lookup(struct inode *dir,
+ struct dentry *dentry, struct nameidata *nd);
static int cgroup_mkdir(struct inode *dir, struct dentry *dentry, int mode);
static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry);
static int cgroup_populate_dir(struct cgroup *cgrp);
struct list_head *node;
BUG_ON(!mutex_is_locked(&dentry->d_inode->i_mutex));
- spin_lock(&dcache_lock);
+ spin_lock(&dentry->d_lock);
node = dentry->d_subdirs.next;
while (node != &dentry->d_subdirs) {
struct dentry *d = list_entry(node, struct dentry, d_u.d_child);
+
+ spin_lock_nested(&d->d_lock, DENTRY_D_LOCK_NESTED);
list_del_init(node);
if (d->d_inode) {
/* This should never be called on a cgroup
* directory with child cgroups */
BUG_ON(d->d_inode->i_mode & S_IFDIR);
- d = dget_locked(d);
- spin_unlock(&dcache_lock);
+ dget_dlock(d);
+ spin_unlock(&d->d_lock);
+ spin_unlock(&dentry->d_lock);
d_delete(d);
simple_unlink(dentry->d_inode, d);
dput(d);
- spin_lock(&dcache_lock);
- }
+ spin_lock(&dentry->d_lock);
+ } else
+ spin_unlock(&d->d_lock);
node = dentry->d_subdirs.next;
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&dentry->d_lock);
}
/*
*/
static void cgroup_d_remove_dir(struct dentry *dentry)
{
+ struct dentry *parent;
+
cgroup_clear_directory(dentry);
- spin_lock(&dcache_lock);
+ parent = dentry->d_parent;
+ spin_lock(&parent->d_lock);
+ spin_lock(&dentry->d_lock);
list_del_init(&dentry->d_u.d_child);
- spin_unlock(&dcache_lock);
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&parent->d_lock);
remove_dir(dentry);
}
};
static const struct inode_operations cgroup_dir_inode_operations = {
- .lookup = simple_lookup,
+ .lookup = cgroup_lookup,
.mkdir = cgroup_mkdir,
.rmdir = cgroup_rmdir,
.rename = cgroup_rename,
return __d_cft(file->f_dentry);
}
-static int cgroup_create_file(struct dentry *dentry, mode_t mode,
- struct super_block *sb)
+static int cgroup_delete_dentry(const struct dentry *dentry)
+{
+ return 1;
+}
+
+static struct dentry *cgroup_lookup(struct inode *dir,
+ struct dentry *dentry, struct nameidata *nd)
{
- static const struct dentry_operations cgroup_dops = {
+ static const struct dentry_operations cgroup_dentry_operations = {
+ .d_delete = cgroup_delete_dentry,
.d_iput = cgroup_diput,
};
+ if (dentry->d_name.len > NAME_MAX)
+ return ERR_PTR(-ENAMETOOLONG);
+ d_set_d_op(dentry, &cgroup_dentry_operations);
+ d_add(dentry, NULL);
+ return NULL;
+}
+
+static int cgroup_create_file(struct dentry *dentry, mode_t mode,
+ struct super_block *sb)
+{
struct inode *inode;
if (!dentry)
inode->i_size = 0;
inode->i_fop = &cgroup_file_operations;
}
- dentry->d_op = &cgroup_dops;
d_instantiate(dentry, inode);
dget(dentry); /* Extra count - pin the dentry in core */
return 0;
list_del(&cgrp->sibling);
cgroup_unlock_hierarchy(cgrp->root);
- spin_lock(&cgrp->dentry->d_lock);
d = dget(cgrp->dentry);
- spin_unlock(&d->d_lock);
cgroup_d_remove_dir(d);
dput(d);
* ->inode_lock (zap_pte_range->set_page_dirty)
* ->private_lock (zap_pte_range->__set_page_dirty_buffers)
*
- * ->task->proc_lock
- * ->dcache_lock (proc_pid_lookup)
- *
* (code doesn't rely on that order, so you could switch it around)
* ->tasklist_lock (memory_failure, collect_procs_ao)
* ->i_mmap_lock
return &p->vfs_inode;
}
+static void shmem_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
+ kmem_cache_free(shmem_inode_cachep, SHMEM_I(inode));
+}
+
static void shmem_destroy_inode(struct inode *inode)
{
if ((inode->i_mode & S_IFMT) == S_IFREG) {
/* only struct inode is valid if it's an inline symlink */
mpol_free_shared_policy(&SHMEM_I(inode)->policy);
}
- kmem_cache_free(shmem_inode_cachep, SHMEM_I(inode));
+ call_rcu(&inode->i_rcu, shmem_i_callback);
}
static void init_once(void *foo)
/*
* Map pages beginning at addr to the given cache and slab. This is required
* for the slab allocator to be able to lookup the cache and slab of a
- * virtual address for kfree, ksize, kmem_ptr_validate, and slab debugging.
+ * virtual address for kfree, ksize, and slab debugging.
*/
static void slab_map_pages(struct kmem_cache *cache, struct slab *slab,
void *addr)
EXPORT_SYMBOL(kmem_cache_alloc_notrace);
#endif
-/**
- * kmem_ptr_validate - check if an untrusted pointer might be a slab entry.
- * @cachep: the cache we're checking against
- * @ptr: pointer to validate
- *
- * This verifies that the untrusted pointer looks sane;
- * it is _not_ a guarantee that the pointer is actually
- * part of the slab cache in question, but it at least
- * validates that the pointer can be dereferenced and
- * looks half-way sane.
- *
- * Currently only used for dentry validation.
- */
-int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr)
-{
- unsigned long size = cachep->buffer_size;
- struct page *page;
-
- if (unlikely(!kern_ptr_validate(ptr, size)))
- goto out;
- page = virt_to_page(ptr);
- if (unlikely(!PageSlab(page)))
- goto out;
- if (unlikely(page_get_cache(page) != cachep))
- goto out;
- return 1;
-out:
- return 0;
-}
-
#ifdef CONFIG_NUMA
void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
{
}
EXPORT_SYMBOL(kmem_cache_shrink);
-int kmem_ptr_validate(struct kmem_cache *a, const void *b)
-{
- return 0;
-}
-
static unsigned int slob_ready __read_mostly;
int slab_is_available(void)
}
EXPORT_SYMBOL(kmem_cache_free);
-/* Figure out on which slab page the object resides */
-static struct page *get_object_page(const void *x)
-{
- struct page *page = virt_to_head_page(x);
-
- if (!PageSlab(page))
- return NULL;
-
- return page;
-}
-
/*
* Object placement in a slab is made very easy because we always start at
* offset 0. If we tune the size of the object to the alignment then we can
}
/*
- * Check if a given pointer is valid
- */
-int kmem_ptr_validate(struct kmem_cache *s, const void *object)
-{
- struct page *page;
-
- if (!kern_ptr_validate(object, s->size))
- return 0;
-
- page = get_object_page(object);
-
- if (!page || s != page->slab)
- /* No slab or wrong slab */
- return 0;
-
- if (!check_valid_pointer(s, page, object))
- return 0;
-
- /*
- * We could also check if the object is on the slabs freelist.
- * But this would be too expensive and it seems that the main
- * purpose of kmem_ptr_valid() is to check if the object belongs
- * to a certain slab.
- */
- return 1;
-}
-EXPORT_SYMBOL(kmem_ptr_validate);
-
-/*
* Determine the size of a slab object
*/
unsigned int kmem_cache_size(struct kmem_cache *s)
}
EXPORT_SYMBOL(kzfree);
-int kern_ptr_validate(const void *ptr, unsigned long size)
-{
- unsigned long addr = (unsigned long)ptr;
- unsigned long min_addr = PAGE_OFFSET;
- unsigned long align_mask = sizeof(void *) - 1;
-
- if (unlikely(addr < min_addr))
- goto out;
- if (unlikely(addr > (unsigned long)high_memory - size))
- goto out;
- if (unlikely(addr & align_mask))
- goto out;
- if (unlikely(!kern_addr_valid(addr)))
- goto out;
- if (unlikely(!kern_addr_valid(addr + size - 1)))
- goto out;
- return 1;
-out:
- return 0;
-}
-
/*
* strndup_user - duplicate an existing string from user space
* @s: The string to duplicate
}
+
static void wq_free_rcu(struct rcu_head *head)
{
struct socket_wq *wq = container_of(head, struct socket_wq, rcu);
if (unlikely(fd < 0))
return fd;
- path.dentry = d_alloc(sock_mnt->mnt_sb->s_root, &name);
+ path.dentry = d_alloc_pseudo(sock_mnt->mnt_sb, &name);
if (unlikely(!path.dentry)) {
put_unused_fd(fd);
return -ENOMEM;
}
path.mnt = mntget(sock_mnt);
- path.dentry->d_op = &sockfs_dentry_operations;
+ d_set_d_op(path.dentry, &sockfs_dentry_operations);
d_instantiate(path.dentry, SOCK_INODE(sock));
SOCK_INODE(sock)->i_fop = &socket_file_ops;
static int __init sock_init(void)
{
+ int err;
+
/*
* Initialize sock SLAB cache.
*/
*/
init_inodecache();
- register_filesystem(&sock_fs_type);
+
+ err = register_filesystem(&sock_fs_type);
+ if (err)
+ goto out_fs;
sock_mnt = kern_mount(&sock_fs_type);
+ if (IS_ERR(sock_mnt)) {
+ err = PTR_ERR(sock_mnt);
+ goto out_mount;
+ }
/* The real protocol initialization is performed in later initcalls.
*/
skb_timestamping_init();
#endif
- return 0;
+out:
+ return err;
+
+out_mount:
+ unregister_filesystem(&sock_fs_type);
+out_fs:
+ goto out;
}
core_initcall(sock_init); /* early initcall */
}
static void
-rpc_destroy_inode(struct inode *inode)
+rpc_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
}
+static void
+rpc_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, rpc_i_callback);
+}
+
static int
rpc_pipe_open(struct inode *inode, struct file *filp)
{
}
EXPORT_SYMBOL_GPL(rpc_put_mount);
-static int rpc_delete_dentry(struct dentry *dentry)
+static int rpc_delete_dentry(const struct dentry *dentry)
{
return 1;
}
}
}
if (!dentry->d_inode)
- dentry->d_op = &rpc_dentry_operations;
+ d_set_d_op(dentry, &rpc_dentry_operations);
out_err:
return dentry;
}
return security_ops->inode_permission(inode, mask);
}
+int security_inode_exec_permission(struct inode *inode, unsigned int flags)
+{
+ if (unlikely(IS_PRIVATE(inode)))
+ return 0;
+ if (flags)
+ return -ECHILD;
+ return security_ops->inode_permission(inode, MAY_EXEC);
+}
+
int security_inode_setattr(struct dentry *dentry, struct iattr *attr)
{
if (unlikely(IS_PRIVATE(dentry->d_inode)))
{
struct list_head *node;
- spin_lock(&dcache_lock);
+ spin_lock(&de->d_lock);
node = de->d_subdirs.next;
while (node != &de->d_subdirs) {
struct dentry *d = list_entry(node, struct dentry, d_u.d_child);
+
+ spin_lock_nested(&d->d_lock, DENTRY_D_LOCK_NESTED);
list_del_init(node);
if (d->d_inode) {
- d = dget_locked(d);
- spin_unlock(&dcache_lock);
+ dget_dlock(d);
+ spin_unlock(&de->d_lock);
+ spin_unlock(&d->d_lock);
d_delete(d);
simple_unlink(de->d_inode, d);
dput(d);
- spin_lock(&dcache_lock);
- }
+ spin_lock(&de->d_lock);
+ } else
+ spin_unlock(&d->d_lock);
node = de->d_subdirs.next;
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&de->d_lock);
}
#define BOOL_DIR_NAME "booleans"
#include <linux/slab.h>
#include <net/sock.h>
#include "common.h"
+#include "../../fs/internal.h"
/**
* tomoyo_encode: Convert binary string to ascii string.
projects / profile / ivi / kernel-adaptation-intel-automotive.git / commitdiff