diff options
| -rw-r--r-- | fs/namei.c | 63 |
1 files changed, 53 insertions, 10 deletions
diff --git a/fs/namei.c b/fs/namei.c index 9e7b18a8be6..a3431639e16 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1588,12 +1588,23 @@ out_fail: return retval; } +static inline int lookup_last(struct nameidata *nd, struct path *path) +{ + if (nd->last_type == LAST_NORM && nd->last.name[nd->last.len]) + nd->flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY; + + nd->flags &= ~LOOKUP_PARENT; + return walk_component(nd, path, &nd->last, nd->last_type, + nd->flags & LOOKUP_FOLLOW); +} + /* Returns 0 and nd will be valid on success; Retuns error, otherwise. */ static int path_lookupat(int dfd, const char *name, unsigned int flags, struct nameidata *nd) { struct file *base = NULL; - int retval; + struct path path; + int err; /* * Path walking is largely split up into 2 different synchronisation @@ -1609,23 +1620,55 @@ static int path_lookupat(int dfd, const char *name, * be handled by restarting a traditional ref-walk (which will always * be able to complete). */ - retval = path_init(dfd, name, flags, nd, &base); + err = path_init(dfd, name, flags | LOOKUP_PARENT, nd, &base); - if (unlikely(retval)) - return retval; + if (unlikely(err)) + return err; current->total_link_count = 0; - retval = link_path_walk(name, nd); + err = link_path_walk(name, nd); + + if (!err && !(flags & LOOKUP_PARENT)) { + int count = 0; + err = lookup_last(nd, &path); + while (err > 0) { + void *cookie; + struct path link = path; + struct inode *inode = link.dentry->d_inode; + + if (count++ > 32) { + path_put_conditional(&path, nd); + path_put(&nd->path); + err = -ELOOP; + break; + } + cond_resched(); + nd->flags |= LOOKUP_PARENT; + err = __do_follow_link(&link, nd, &cookie); + if (!err) + err = lookup_last(nd, &path); + if (!IS_ERR(cookie) && inode->i_op->put_link) + inode->i_op->put_link(link.dentry, nd, cookie); + path_put(&link); + } + } if (nd->flags & LOOKUP_RCU) { /* went all way through without dropping RCU */ - BUG_ON(retval); + BUG_ON(err); if (nameidata_drop_rcu_last(nd)) - retval = -ECHILD; + err = -ECHILD; } - if (!retval) - retval = handle_reval_path(nd); + if (!err) + err = handle_reval_path(nd); + + if (!err && nd->flags & LOOKUP_DIRECTORY) { + if (!nd->inode->i_op->lookup) { + path_put(&nd->path); + return -ENOTDIR; + } + } if (base) fput(base); @@ -1634,7 +1677,7 @@ static int path_lookupat(int dfd, const char *name, path_put(&nd->root); nd->root.mnt = NULL; } - return retval; + return err; } static int do_path_lookup(int dfd, const char *name, |