/**
* unlazy_walk - try to switch to ref-walk mode.
* @nd: nameidata pathwalk data
- * @dentry: child of nd->path.dentry or NULL
- * @seq: seq number to check dentry against
* Returns: 0 on success, -ECHILD on failure
*
- * unlazy_walk attempts to legitimize the current nd->path, nd->root and dentry
- * for ref-walk mode. @dentry must be a path found by a do_lookup call on
- * @nd or NULL. Must be called from rcu-walk context.
+ * unlazy_walk attempts to legitimize the current nd->path and nd->root
+ * for ref-walk mode.
+ * Must be called from rcu-walk context.
* Nothing should touch nameidata between unlazy_walk() failure and
* terminate_walk().
*/
-static int unlazy_walk(struct nameidata *nd, struct dentry *dentry, unsigned seq)
+static int unlazy_walk(struct nameidata *nd)
{
struct dentry *parent = nd->path.dentry;
nd->flags &= ~LOOKUP_RCU;
if (unlikely(!legitimize_links(nd)))
goto out2;
+ if (unlikely(!legitimize_path(nd, &nd->path, nd->seq)))
+ goto out1;
+ if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT)) {
+ if (unlikely(!legitimize_path(nd, &nd->root, nd->root_seq)))
+ goto out;
+ }
+ rcu_read_unlock();
+ BUG_ON(nd->inode != parent->d_inode);
+ return 0;
+
+out2:
+ nd->path.mnt = NULL;
+ nd->path.dentry = NULL;
+out1:
+ if (!(nd->flags & LOOKUP_ROOT))
+ nd->root.mnt = NULL;
+out:
+ rcu_read_unlock();
+ return -ECHILD;
+}
+
+/**
+ * unlazy_child - try to switch to ref-walk mode.
+ * @nd: nameidata pathwalk data
+ * @dentry: child of nd->path.dentry
+ * @seq: seq number to check dentry against
+ * Returns: 0 on success, -ECHILD on failure
+ *
+ * unlazy_child attempts to legitimize the current nd->path, nd->root and dentry
+ * for ref-walk mode. @dentry must be a path found by a do_lookup call on
+ * @nd. Must be called from rcu-walk context.
+ * Nothing should touch nameidata between unlazy_child() failure and
+ * terminate_walk().
+ */
+static int unlazy_child(struct nameidata *nd, struct dentry *dentry, unsigned seq)
+{
+ BUG_ON(!(nd->flags & LOOKUP_RCU));
+
+ nd->flags &= ~LOOKUP_RCU;
+ if (unlikely(!legitimize_links(nd)))
+ goto out2;
if (unlikely(!legitimize_mnt(nd->path.mnt, nd->m_seq)))
goto out2;
- if (unlikely(!lockref_get_not_dead(&parent->d_lockref)))
+ if (unlikely(!lockref_get_not_dead(&nd->path.dentry->d_lockref)))
goto out1;
/*
- * For a negative lookup, the lookup sequence point is the parents
- * sequence point, and it only needs to revalidate the parent dentry.
- *
- * For a positive lookup, we need to move both the parent and the
- * dentry from the RCU domain to be properly refcounted. And the
- * sequence number in the dentry validates *both* dentry counters,
- * since we checked the sequence number of the parent after we got
- * the child sequence number. So we know the parent must still
- * be valid if the child sequence number is still valid.
+ * We need to move both the parent and the dentry from the RCU domain
+ * to be properly refcounted. And the sequence number in the dentry
+ * validates *both* dentry counters, since we checked the sequence
+ * number of the parent after we got the child sequence number. So we
+ * know the parent must still be valid if the child sequence number is
*/
- if (!dentry) {
- if (read_seqcount_retry(&parent->d_seq, nd->seq))
- goto out;
- BUG_ON(nd->inode != parent->d_inode);
- } else {
- if (!lockref_get_not_dead(&dentry->d_lockref))
- goto out;
- if (read_seqcount_retry(&dentry->d_seq, seq))
- goto drop_dentry;
+ if (unlikely(!lockref_get_not_dead(&dentry->d_lockref)))
+ goto out;
+ if (unlikely(read_seqcount_retry(&dentry->d_seq, seq))) {
+ rcu_read_unlock();
+ dput(dentry);
+ goto drop_root_mnt;
}
-
/*
* Sequence counts matched. Now make sure that the root is
* still valid and get it if required.
rcu_read_unlock();
return 0;
-drop_dentry:
- rcu_read_unlock();
- dput(dentry);
- goto drop_root_mnt;
out2:
nd->path.mnt = NULL;
out1:
return -ECHILD;
}
-static int unlazy_link(struct nameidata *nd, struct path *link, unsigned seq)
-{
- if (unlikely(!legitimize_path(nd, link, seq))) {
- drop_links(nd);
- nd->depth = 0;
- nd->flags &= ~LOOKUP_RCU;
- nd->path.mnt = NULL;
- nd->path.dentry = NULL;
- if (!(nd->flags & LOOKUP_ROOT))
- nd->root.mnt = NULL;
- rcu_read_unlock();
- } else if (likely(unlazy_walk(nd, NULL, 0)) == 0) {
- return 0;
- }
- path_put(link);
- return -ECHILD;
-}
-
static inline int d_revalidate(struct dentry *dentry, unsigned int flags)
{
- return dentry->d_op->d_revalidate(dentry, flags);
+ if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE))
+ return dentry->d_op->d_revalidate(dentry, flags);
+ else
+ return 1;
}
/**
if (nd->flags & LOOKUP_RCU) {
if (!(nd->flags & LOOKUP_ROOT))
nd->root.mnt = NULL;
- if (unlikely(unlazy_walk(nd, NULL, 0)))
+ if (unlikely(unlazy_walk(nd)))
return -ECHILD;
}
touch_atime(&last->link);
cond_resched();
} else if (atime_needs_update_rcu(&last->link, inode)) {
- if (unlikely(unlazy_walk(nd, NULL, 0)))
+ if (unlikely(unlazy_walk(nd)))
return ERR_PTR(-ECHILD);
touch_atime(&last->link);
}
if (nd->flags & LOOKUP_RCU) {
res = get(NULL, inode, &last->done);
if (res == ERR_PTR(-ECHILD)) {
- if (unlikely(unlazy_walk(nd, NULL, 0)))
+ if (unlikely(unlazy_walk(nd)))
return ERR_PTR(-ECHILD);
res = get(dentry, inode, &last->done);
}
bool *need_mntput)
{
struct vfsmount *mnt;
- const struct cred *old_cred;
int err;
if (!path->dentry->d_op || !path->dentry->d_op->d_automount)
if (nd->total_link_count >= 40)
return -ELOOP;
- old_cred = override_creds(&init_cred);
mnt = path->dentry->d_op->d_automount(path);
- revert_creds(old_cred);
if (IS_ERR(mnt)) {
/*
* The filesystem is allowed to return -EISDIR here to indicate
struct dentry *dir,
unsigned int flags)
{
- struct dentry *dentry;
- int error;
-
- dentry = d_lookup(dir, name);
+ struct dentry *dentry = d_lookup(dir, name);
if (dentry) {
- if (dentry->d_flags & DCACHE_OP_REVALIDATE) {
- error = d_revalidate(dentry, flags);
- if (unlikely(error <= 0)) {
- if (!error)
- d_invalidate(dentry);
- dput(dentry);
- return ERR_PTR(error);
- }
+ int error = d_revalidate(dentry, flags);
+ if (unlikely(error <= 0)) {
+ if (!error)
+ d_invalidate(dentry);
+ dput(dentry);
+ return ERR_PTR(error);
}
}
return dentry;
bool negative;
dentry = __d_lookup_rcu(parent, &nd->last, &seq);
if (unlikely(!dentry)) {
- if (unlazy_walk(nd, NULL, 0))
+ if (unlazy_walk(nd))
return -ECHILD;
return 0;
}
return -ECHILD;
*seqp = seq;
- if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE))
- status = d_revalidate(dentry, nd->flags);
- if (unlikely(status <= 0)) {
- if (unlazy_walk(nd, dentry, seq))
- return -ECHILD;
- if (status == -ECHILD)
- status = d_revalidate(dentry, nd->flags);
- } else {
+ status = d_revalidate(dentry, nd->flags);
+ if (likely(status > 0)) {
/*
* Note: do negative dentry check after revalidation in
* case that drops it.
path->dentry = dentry;
if (likely(__follow_mount_rcu(nd, path, inode, seqp)))
return 1;
- if (unlazy_walk(nd, dentry, seq))
- return -ECHILD;
}
+ if (unlazy_child(nd, dentry, seq))
+ return -ECHILD;
+ if (unlikely(status == -ECHILD))
+ /* we'd been told to redo it in non-rcu mode */
+ status = d_revalidate(dentry, nd->flags);
} else {
dentry = __d_lookup(parent, &nd->last);
if (unlikely(!dentry))
return 0;
- if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE))
- status = d_revalidate(dentry, nd->flags);
+ status = d_revalidate(dentry, nd->flags);
}
if (unlikely(status <= 0)) {
if (!status)
if (IS_ERR(dentry))
goto out;
if (unlikely(!d_in_lookup(dentry))) {
- if ((dentry->d_flags & DCACHE_OP_REVALIDATE) &&
- !(flags & LOOKUP_NO_REVAL)) {
+ if (!(flags & LOOKUP_NO_REVAL)) {
int error = d_revalidate(dentry, flags);
if (unlikely(error <= 0)) {
if (!error) {
int err = inode_permission(nd->inode, MAY_EXEC|MAY_NOT_BLOCK);
if (err != -ECHILD)
return err;
- if (unlazy_walk(nd, NULL, 0))
+ if (unlazy_walk(nd))
return -ECHILD;
}
return inode_permission(nd->inode, MAY_EXEC);
error = nd_alloc_stack(nd);
if (unlikely(error)) {
if (error == -ECHILD) {
- if (unlikely(unlazy_link(nd, link, seq)))
- return -ECHILD;
- error = nd_alloc_stack(nd);
+ if (unlikely(!legitimize_path(nd, link, seq))) {
+ drop_links(nd);
+ nd->depth = 0;
+ nd->flags &= ~LOOKUP_RCU;
+ nd->path.mnt = NULL;
+ nd->path.dentry = NULL;
+ if (!(nd->flags & LOOKUP_ROOT))
+ nd->root.mnt = NULL;
+ rcu_read_unlock();
+ } else if (likely(unlazy_walk(nd)) == 0)
+ error = nd_alloc_stack(nd);
}
if (error) {
path_put(link);
}
if (unlikely(!d_can_lookup(nd->path.dentry))) {
if (nd->flags & LOOKUP_RCU) {
- if (unlazy_walk(nd, NULL, 0))
+ if (unlazy_walk(nd))
return -ECHILD;
}
return -ENOTDIR;
/* If we're in rcuwalk, drop out of it to handle last component */
if (nd->flags & LOOKUP_RCU) {
- if (unlazy_walk(nd, NULL, 0))
+ if (unlazy_walk(nd))
return -ECHILD;
}
static int may_o_create(const struct path *dir, struct dentry *dentry, umode_t mode)
{
+ struct user_namespace *s_user_ns;
int error = security_path_mknod(dir, dentry, mode, 0);
if (error)
return error;
+ s_user_ns = dir->dentry->d_sb->s_user_ns;
+ if (!kuid_has_mapping(s_user_ns, current_fsuid()) ||
+ !kgid_has_mapping(s_user_ns, current_fsgid()))
+ return -EOVERFLOW;
+
error = inode_permission(dir->dentry->d_inode, MAY_WRITE | MAY_EXEC);
if (error)
return error;
if (d_in_lookup(dentry))
break;
- if (!(dentry->d_flags & DCACHE_OP_REVALIDATE))
- break;
-
error = d_revalidate(dentry, nd->flags);
if (likely(error > 0))
break;
return error;
}
+ struct dentry *vfs_tmpfile(struct dentry *dentry, umode_t mode, int open_flag)
+ {
+ static const struct qstr name = QSTR_INIT("/", 1);
+ struct dentry *child = NULL;
+ struct inode *dir = dentry->d_inode;
+ struct inode *inode;
+ int error;
+
+ /* we want directory to be writable */
+ error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
+ if (error)
+ goto out_err;
+ error = -EOPNOTSUPP;
+ if (!dir->i_op->tmpfile)
+ goto out_err;
+ error = -ENOMEM;
+ child = d_alloc(dentry, &name);
+ if (unlikely(!child))
+ goto out_err;
+ error = dir->i_op->tmpfile(dir, child, mode);
+ if (error)
+ goto out_err;
+ error = -ENOENT;
+ inode = child->d_inode;
+ if (unlikely(!inode))
+ goto out_err;
+ if (!(open_flag & O_EXCL)) {
+ spin_lock(&inode->i_lock);
+ inode->i_state |= I_LINKABLE;
+ spin_unlock(&inode->i_lock);
+ }
+ return child;
+
+ out_err:
+ dput(child);
+ return ERR_PTR(error);
+ }
+ EXPORT_SYMBOL(vfs_tmpfile);
+
static int do_tmpfile(struct nameidata *nd, unsigned flags,
const struct open_flags *op,
struct file *file, int *opened)
{
- static const struct qstr name = QSTR_INIT("/", 1);
struct dentry *child;
- struct inode *dir;
struct path path;
int error = path_lookupat(nd, flags | LOOKUP_DIRECTORY, &path);
if (unlikely(error))
error = mnt_want_write(path.mnt);
if (unlikely(error))
goto out;
- dir = path.dentry->d_inode;
- /* we want directory to be writable */
- error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
- if (error)
+ child = vfs_tmpfile(path.dentry, op->mode, op->open_flag);
+ error = PTR_ERR(child);
+ if (unlikely(IS_ERR(child)))
goto out2;
- if (!dir->i_op->tmpfile) {
- error = -EOPNOTSUPP;
- goto out2;
- }
- child = d_alloc(path.dentry, &name);
- if (unlikely(!child)) {
- error = -ENOMEM;
- goto out2;
- }
dput(path.dentry);
path.dentry = child;
- error = dir->i_op->tmpfile(dir, child, op->mode);
- if (error)
- goto out2;
audit_inode(nd->name, child, 0);
/* Don't check for other permissions, the inode was just created */
error = may_open(&path, 0, op->open_flag);
if (error)
goto out2;
error = open_check_o_direct(file);
- if (error) {
+ if (error)
fput(file);
- } else if (!(op->open_flag & O_EXCL)) {
- struct inode *inode = file_inode(file);
- spin_lock(&inode->i_lock);
- inode->i_state |= I_LINKABLE;
- spin_unlock(&inode->i_lock);
- }
out2:
mnt_drop_write(path.mnt);
out:
int bd_invalidated;
struct gendisk * bd_disk;
struct request_queue * bd_queue;
+ struct backing_dev_info *bd_bdi;
struct list_head bd_list;
/*
* Private data. You must have bd_claim'ed the block_device
extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *, struct inode **, unsigned int);
extern int vfs_whiteout(struct inode *, struct dentry *);
+ extern struct dentry *vfs_tmpfile(struct dentry *dentry, umode_t mode,
+ int open_flag);
+
/*
* VFS file helper functions.
*/
int (*set_acl)(struct inode *, struct posix_acl *, int);
} ____cacheline_aligned;
+ static inline ssize_t call_read_iter(struct file *file, struct kiocb *kio,
+ struct iov_iter *iter)
+ {
+ return file->f_op->read_iter(kio, iter);
+ }
+
+ static inline ssize_t call_write_iter(struct file *file, struct kiocb *kio,
+ struct iov_iter *iter)
+ {
+ return file->f_op->write_iter(kio, iter);
+ }
+
+ static inline int call_mmap(struct file *file, struct vm_area_struct *vma)
+ {
+ return file->f_op->mmap(file, vma);
+ }
+
+ static inline int call_fsync(struct file *file, loff_t start, loff_t end,
+ int datasync)
+ {
+ return file->f_op->fsync(file, start, end, datasync);
+ }
+
ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
unsigned long nr_segs, unsigned long fast_segs,
struct iovec *fast_pointer,
extern int vfs_dedupe_file_range(struct file *file,
struct file_dedupe_range *same);
- static inline int do_clone_file_range(struct file *file_in, loff_t pos_in,
- struct file *file_out, loff_t pos_out,
- u64 len)
- {
- int ret;
-
- sb_start_write(file_inode(file_out)->i_sb);
- ret = vfs_clone_file_range(file_in, pos_in, file_out, pos_out, len);
- sb_end_write(file_inode(file_out)->i_sb);
-
- return ret;
- }
-
struct super_operations {
struct inode *(*alloc_inode)(struct super_block *sb);
void (*destroy_inode)(struct inode *);
#ifdef CONFIG_BLOCK
extern int register_blkdev(unsigned int, const char *);
extern void unregister_blkdev(unsigned int, const char *);
+extern void bdev_unhash_inode(dev_t dev);
extern struct block_device *bdget(dev_t);
extern struct block_device *bdgrab(struct block_device *bdev);
extern void bd_set_size(struct block_device *, loff_t size);
__sb_end_write(file_inode(file)->i_sb, SB_FREEZE_WRITE);
}
+ static inline int do_clone_file_range(struct file *file_in, loff_t pos_in,
+ struct file *file_out, loff_t pos_out,
+ u64 len)
+ {
+ int ret;
+
+ file_start_write(file_out);
+ ret = vfs_clone_file_range(file_in, pos_in, file_out, pos_out, len);
+ file_end_write(file_out);
+
+ return ret;
+ }
+
/*
* get_write_access() gets write permission for a file.
* put_write_access() releases this write permission.
projects / platform / kernel / linux-exynos.git / commitdiff