diff options
Diffstat (limited to 'fs/namei.c')
| -rw-r--r-- | fs/namei.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/fs/namei.c b/fs/namei.c index 60c0a78ebca7..646db9cf2579 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2252,6 +2252,35 @@ static inline int lookup_last(struct nameidata *nd) return walk_component(nd, 0); } +static int handle_lookup_down(struct nameidata *nd) +{ + struct path path = nd->path; + struct inode *inode = nd->inode; + unsigned seq = nd->seq; + int err; + + if (nd->flags & LOOKUP_RCU) { + /* + * don't bother with unlazy_walk on failure - we are + * at the very beginning of walk, so we lose nothing + * if we simply redo everything in non-RCU mode + */ + if (unlikely(!__follow_mount_rcu(nd, &path, &inode, &seq))) + return -ECHILD; + } else { + dget(path.dentry); + err = follow_managed(&path, nd); + if (unlikely(err < 0)) + return err; + inode = d_backing_inode(path.dentry); + seq = 0; + } + path_to_nameidata(&path, nd); + nd->inode = inode; + nd->seq = seq; + return 0; +} + /* Returns 0 and nd will be valid on success; Retuns error, otherwise. */ static int path_lookupat(struct nameidata *nd, unsigned flags, struct path *path) { @@ -2260,6 +2289,15 @@ static int path_lookupat(struct nameidata *nd, unsigned flags, struct path *path if (IS_ERR(s)) return PTR_ERR(s); + + if (unlikely(flags & LOOKUP_DOWN)) { + err = handle_lookup_down(nd); + if (unlikely(err < 0)) { + terminate_walk(nd); + return err; + } + } + while (!(err = link_path_walk(s, nd)) && ((err = lookup_last(nd)) > 0)) { s = trailing_symlink(nd); |