X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=fs%2Fnamei.c;h=7d694194024ac4d2459e7cc3d60014bdff64e3ba;hb=16b1c1cd71176ab0a76b26818fbf12db9183ed57;hp=e70ebab9624bb8666b9c0b70598c83be14bfc63c;hpb=be122abe4bcd6d39b37892daae28c8bf5e4030fc;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git diff --git a/fs/namei.c b/fs/namei.c index e70ebab..7d69419 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -16,6 +16,7 @@ #include #include +#include #include #include #include @@ -448,7 +449,7 @@ static int unlazy_walk(struct nameidata *nd, struct dentry *dentry) mntget(nd->path.mnt); rcu_read_unlock(); - br_read_unlock(vfsmount_lock); + br_read_unlock(&vfsmount_lock); nd->flags &= ~LOOKUP_RCU; return 0; @@ -506,14 +507,14 @@ static int complete_walk(struct nameidata *nd) if (unlikely(!__d_rcu_to_refcount(dentry, nd->seq))) { spin_unlock(&dentry->d_lock); rcu_read_unlock(); - br_read_unlock(vfsmount_lock); + br_read_unlock(&vfsmount_lock); return -ECHILD; } BUG_ON(nd->inode != dentry->d_inode); spin_unlock(&dentry->d_lock); mntget(nd->path.mnt); rcu_read_unlock(); - br_read_unlock(vfsmount_lock); + br_read_unlock(&vfsmount_lock); } if (likely(!(nd->flags & LOOKUP_JUMPED))) @@ -680,15 +681,15 @@ int follow_up(struct path *path) struct mount *parent; struct dentry *mountpoint; - br_read_lock(vfsmount_lock); + br_read_lock(&vfsmount_lock); parent = mnt->mnt_parent; if (&parent->mnt == path->mnt) { - br_read_unlock(vfsmount_lock); + br_read_unlock(&vfsmount_lock); return 0; } mntget(&parent->mnt); mountpoint = dget(mnt->mnt_mountpoint); - br_read_unlock(vfsmount_lock); + br_read_unlock(&vfsmount_lock); dput(path->dentry); path->dentry = mountpoint; mntput(path->mnt); @@ -946,7 +947,7 @@ failed: if (!(nd->flags & LOOKUP_ROOT)) nd->root.mnt = NULL; rcu_read_unlock(); - br_read_unlock(vfsmount_lock); + br_read_unlock(&vfsmount_lock); return -ECHILD; } @@ -1124,8 +1125,8 @@ static struct dentry *__lookup_hash(struct qstr *name, * small and for now I'd prefer to have fast path as straight as possible. * It _is_ time-critical. */ -static int do_lookup(struct nameidata *nd, struct qstr *name, - struct path *path, struct inode **inode) +static int lookup_fast(struct nameidata *nd, struct qstr *name, + struct path *path, struct inode **inode) { struct vfsmount *mnt = nd->path.mnt; struct dentry *dentry, *parent = nd->path.dentry; @@ -1207,7 +1208,7 @@ unlazy: goto need_lookup; } } -done: + path->mnt = mnt; path->dentry = dentry; err = follow_managed(path, nd->flags); @@ -1221,6 +1222,17 @@ done: return 0; need_lookup: + return 1; +} + +/* Fast lookup failed, do it the slow way */ +static int lookup_slow(struct nameidata *nd, struct qstr *name, + struct path *path) +{ + struct dentry *dentry, *parent; + int err; + + parent = nd->path.dentry; BUG_ON(nd->inode != parent->d_inode); mutex_lock(&parent->d_inode->i_mutex); @@ -1228,7 +1240,16 @@ need_lookup: mutex_unlock(&parent->d_inode->i_mutex); if (IS_ERR(dentry)) return PTR_ERR(dentry); - goto done; + path->mnt = nd->path.mnt; + path->dentry = dentry; + err = follow_managed(path, nd->flags); + if (unlikely(err < 0)) { + path_put_conditional(path, nd); + return err; + } + if (err) + nd->flags |= LOOKUP_JUMPED; + return 0; } static inline int may_lookup(struct nameidata *nd) @@ -1264,7 +1285,7 @@ static void terminate_walk(struct nameidata *nd) if (!(nd->flags & LOOKUP_ROOT)) nd->root.mnt = NULL; rcu_read_unlock(); - br_read_unlock(vfsmount_lock); + br_read_unlock(&vfsmount_lock); } } @@ -1300,21 +1321,26 @@ static inline int walk_component(struct nameidata *nd, struct path *path, */ if (unlikely(type != LAST_NORM)) return handle_dots(nd, type); - err = do_lookup(nd, name, path, &inode); + err = lookup_fast(nd, name, path, &inode); if (unlikely(err)) { - terminate_walk(nd); - return err; - } - if (!inode) { - path_to_nameidata(path, nd); - terminate_walk(nd); - return -ENOENT; + if (err < 0) + goto out_err; + + err = lookup_slow(nd, name, path); + if (err < 0) + goto out_err; + + inode = path->dentry->d_inode; } + err = -ENOENT; + if (!inode) + goto out_path_put; + if (should_follow_link(inode, follow)) { if (nd->flags & LOOKUP_RCU) { if (unlikely(unlazy_walk(nd, path->dentry))) { - terminate_walk(nd); - return -ECHILD; + err = -ECHILD; + goto out_err; } } BUG_ON(inode != path->dentry->d_inode); @@ -1323,6 +1349,12 @@ static inline int walk_component(struct nameidata *nd, struct path *path, path_to_nameidata(path, nd); nd->inode = inode; return 0; + +out_path_put: + path_to_nameidata(path, nd); +out_err: + terminate_walk(nd); + return err; } /* @@ -1451,7 +1483,8 @@ EXPORT_SYMBOL(full_name_hash); */ static inline unsigned long hash_name(const char *name, unsigned int *hashp) { - unsigned long a, mask, hash, len; + unsigned long a, b, adata, bdata, mask, hash, len; + const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS; hash = a = 0; len = -sizeof(unsigned long); @@ -1459,17 +1492,18 @@ static inline unsigned long hash_name(const char *name, unsigned int *hashp) hash = (hash + a) * 9; len += sizeof(unsigned long); a = load_unaligned_zeropad(name+len); - /* Do we have any NUL or '/' bytes in this word? */ - mask = has_zero(a) | has_zero(a ^ REPEAT_BYTE('/')); - } while (!mask); - - /* The mask *below* the first high bit set */ - mask = (mask - 1) & ~mask; - mask >>= 7; - hash += a & mask; + b = a ^ REPEAT_BYTE('/'); + } while (!(has_zero(a, &adata, &constants) | has_zero(b, &bdata, &constants))); + + adata = prep_zero_mask(a, adata, &constants); + bdata = prep_zero_mask(b, bdata, &constants); + + mask = create_zero_mask(adata | bdata); + + hash += a & zero_bytemask(mask); *hashp = fold_hash(hash); - return len + count_masked_bytes(mask); + return len + find_zero(mask); } #else @@ -1617,7 +1651,7 @@ static int path_init(int dfd, const char *name, unsigned int flags, nd->path = nd->root; nd->inode = inode; if (flags & LOOKUP_RCU) { - br_read_lock(vfsmount_lock); + br_read_lock(&vfsmount_lock); rcu_read_lock(); nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq); } else { @@ -1630,7 +1664,7 @@ static int path_init(int dfd, const char *name, unsigned int flags, if (*name=='/') { if (flags & LOOKUP_RCU) { - br_read_lock(vfsmount_lock); + br_read_lock(&vfsmount_lock); rcu_read_lock(); set_root_rcu(nd); } else { @@ -1643,7 +1677,7 @@ static int path_init(int dfd, const char *name, unsigned int flags, struct fs_struct *fs = current->fs; unsigned seq; - br_read_lock(vfsmount_lock); + br_read_lock(&vfsmount_lock); rcu_read_lock(); do { @@ -1679,7 +1713,7 @@ static int path_init(int dfd, const char *name, unsigned int flags, if (fput_needed) *fp = file; nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq); - br_read_lock(vfsmount_lock); + br_read_lock(&vfsmount_lock); rcu_read_lock(); } else { path_get(&file->f_path); @@ -2166,6 +2200,10 @@ static struct file *do_last(struct nameidata *nd, struct path *path, int want_write = 0; int acc_mode = op->acc_mode; struct file *filp; + struct inode *inode; + int symlink_ok = 0; + struct path save_parent = { .dentry = NULL, .mnt = NULL }; + bool retried = false; int error; nd->flags &= ~LOOKUP_PARENT; @@ -2197,30 +2235,23 @@ static struct file *do_last(struct nameidata *nd, struct path *path, } if (!(open_flag & O_CREAT)) { - int symlink_ok = 0; if (nd->last.name[nd->last.len]) nd->flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY; if (open_flag & O_PATH && !(nd->flags & LOOKUP_FOLLOW)) symlink_ok = 1; /* we _can_ be in RCU mode here */ - error = walk_component(nd, path, &nd->last, LAST_NORM, - !symlink_ok); - if (error < 0) - return ERR_PTR(error); - if (error) /* symlink */ - return NULL; - /* sayonara */ - error = complete_walk(nd); - if (error) - return ERR_PTR(error); + error = lookup_fast(nd, &nd->last, path, &inode); + if (unlikely(error)) { + if (error < 0) + goto exit; - error = -ENOTDIR; - if (nd->flags & LOOKUP_DIRECTORY) { - if (!nd->inode->i_op->lookup) + error = lookup_slow(nd, &nd->last, path); + if (error < 0) goto exit; + + inode = path->dentry->d_inode; } - audit_inode(pathname, nd->path.dentry); - goto ok; + goto finish_lookup; } /* create side of things */ @@ -2238,6 +2269,7 @@ static struct file *do_last(struct nameidata *nd, struct path *path, if (nd->last.name[nd->last.len]) goto exit; +retry_lookup: mutex_lock(&dir->d_inode->i_mutex); dentry = lookup_hash(nd); @@ -2299,22 +2331,49 @@ static struct file *do_last(struct nameidata *nd, struct path *path, if (error) nd->flags |= LOOKUP_JUMPED; + BUG_ON(nd->flags & LOOKUP_RCU); + inode = path->dentry->d_inode; +finish_lookup: + /* we _can_ be in RCU mode here */ error = -ENOENT; - if (!path->dentry->d_inode) - goto exit_dput; + if (!inode) { + path_to_nameidata(path, nd); + goto exit; + } - if (path->dentry->d_inode->i_op->follow_link) + if (should_follow_link(inode, !symlink_ok)) { + if (nd->flags & LOOKUP_RCU) { + if (unlikely(unlazy_walk(nd, path->dentry))) { + error = -ECHILD; + goto exit; + } + } + BUG_ON(inode != path->dentry->d_inode); return NULL; + } - path_to_nameidata(path, nd); - nd->inode = path->dentry->d_inode; + if ((nd->flags & LOOKUP_RCU) || nd->path.mnt != path->mnt) { + path_to_nameidata(path, nd); + } else { + save_parent.dentry = nd->path.dentry; + save_parent.mnt = mntget(path->mnt); + nd->path.dentry = path->dentry; + + } + nd->inode = inode; /* Why this, you ask? _Now_ we might have grown LOOKUP_JUMPED... */ error = complete_walk(nd); - if (error) + if (error) { + path_put(&save_parent); return ERR_PTR(error); + } error = -EISDIR; - if (S_ISDIR(nd->inode->i_mode)) + if ((open_flag & O_CREAT) && S_ISDIR(nd->inode->i_mode)) + goto exit; + error = -ENOTDIR; + if ((nd->flags & LOOKUP_DIRECTORY) && !nd->inode->i_op->lookup) goto exit; + audit_inode(pathname, nd->path.dentry); ok: if (!S_ISREG(nd->inode->i_mode)) will_truncate = 0; @@ -2330,6 +2389,20 @@ common: if (error) goto exit; filp = nameidata_to_filp(nd); + if (filp == ERR_PTR(-EOPENSTALE) && save_parent.dentry && !retried) { + BUG_ON(save_parent.dentry != dir); + path_put(&nd->path); + nd->path = save_parent; + nd->inode = dir->d_inode; + save_parent.mnt = NULL; + save_parent.dentry = NULL; + if (want_write) { + mnt_drop_write(nd->path.mnt); + want_write = 0; + } + retried = true; + goto retry_lookup; + } if (!IS_ERR(filp)) { error = ima_file_check(filp, op->acc_mode); if (error) { @@ -2349,7 +2422,8 @@ common: out: if (want_write) mnt_drop_write(nd->path.mnt); - path_put(&nd->path); + path_put(&save_parent); + terminate_walk(nd); return filp; exit_mutex_unlock: @@ -2412,6 +2486,12 @@ out: if (base) fput(base); release_open_intent(nd); + if (filp == ERR_PTR(-EOPENSTALE)) { + if (flags & LOOKUP_RCU) + filp = ERR_PTR(-ECHILD); + else + filp = ERR_PTR(-ESTALE); + } return filp; out_filp: