diff options
| -rw-r--r-- | fs/namei.c | 27 | ||||
| -rw-r--r-- | fs/proc/base.c | 3 | ||||
| -rw-r--r-- | include/linux/namei.h | 2 |
3 files changed, 20 insertions, 12 deletions
@@ -586,6 +586,21 @@ static inline void path_to_nameidata(const struct path *path, nd->path.dentry = path->dentry; } +/* + * Helper to directly jump to a known parsed path from ->follow_link, + * caller must have taken a reference to path beforehand. + */ +void nd_jump_link(struct nameidata *nd, struct path *path) +{ + path_put(&nd->path); + + nd->path = *path; + nd->inode = nd->path.dentry->d_inode; + nd->flags |= LOOKUP_JUMPED; + + BUG_ON(nd->inode->i_op->follow_link); +} + static inline void put_link(struct nameidata *nd, struct path *link, void *cookie) { struct inode *inode = link->dentry->d_inode; @@ -630,17 +645,9 @@ follow_link(struct path *link, struct nameidata *nd, void **p) s = nd_get_link(nd); if (s) { error = __vfs_follow_link(nd, s); - } else if (nd->last_type == LAST_BIND) { - nd->flags |= LOOKUP_JUMPED; - nd->inode = nd->path.dentry->d_inode; - if (nd->inode->i_op->follow_link) { - /* stepped on a _really_ weird one */ - path_put(&nd->path); - error = -ELOOP; - } + if (unlikely(error)) + put_link(nd, link, *p); } - if (unlikely(error)) - put_link(nd, link, *p); return error; diff --git a/fs/proc/base.c b/fs/proc/base.c index 3bd5ac1..2772208 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1438,8 +1438,7 @@ static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) if (error) goto out; - path_put(&nd->path); - nd->path = path; + nd_jump_link(nd, &path); return NULL; out: return ERR_PTR(error); diff --git a/include/linux/namei.h b/include/linux/namei.h index f593148..d2ef8b3 100644 --- a/include/linux/namei.h +++ b/include/linux/namei.h @@ -80,6 +80,8 @@ extern int follow_up(struct path *); extern struct dentry *lock_rename(struct dentry *, struct dentry *); extern void unlock_rename(struct dentry *, struct dentry *); +extern void nd_jump_link(struct nameidata *nd, struct path *path); + static inline void nd_set_link(struct nameidata *nd, char *path) { nd->saved_names[nd->depth] = path; |