diff options
Diffstat (limited to 'fs/namei.c')
| -rw-r--r-- | fs/namei.c | 48 |
1 files changed, 40 insertions, 8 deletions
diff --git a/fs/namei.c b/fs/namei.c index 7286f87ce863..6571a5f5112e 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2142,7 +2142,6 @@ OK: static const char *path_init(struct nameidata *nd, unsigned flags) { - int retval = 0; const char *s = nd->name->name; if (!*s) @@ -2154,13 +2153,8 @@ static const char *path_init(struct nameidata *nd, unsigned flags) if (flags & LOOKUP_ROOT) { struct dentry *root = nd->root.dentry; struct inode *inode = root->d_inode; - if (*s) { - if (!d_can_lookup(root)) - return ERR_PTR(-ENOTDIR); - retval = inode_permission(inode, MAY_EXEC); - if (retval) - return ERR_PTR(retval); - } + if (*s && unlikely(!d_can_lookup(root))) + return ERR_PTR(-ENOTDIR); nd->path = nd->root; nd->inode = inode; if (flags & LOOKUP_RCU) { @@ -2258,6 +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) { @@ -2266,6 +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); |