do_last: regularize the logics around following symlinks
authorAl Viro <viro@zeniv.linux.org.uk>
Wed, 22 Apr 2015 16:10:45 +0000 (12:10 -0400)
committerAl Viro <viro@zeniv.linux.org.uk>
Mon, 11 May 2015 02:18:31 +0000 (22:18 -0400)
With LOOKUP_FOLLOW we unlazy and return 1; without it we either
fail with ELOOP or, for O_PATH opens, succeed.  No need to mix
those cases...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
fs/namei.c

index 3e452338f1b7be913ddc5cc359a97f7308853cac..54cbfe799249238756b761818ea95385c9e133b8 100644 (file)
@@ -3046,9 +3046,7 @@ retry_lookup:
                goto out;
        }
 finish_lookup:
-       /* we _can_ be in RCU mode here */
-       if (should_follow_link(path->dentry,
-                       !(open_flag & O_PATH) || (nd->flags & LOOKUP_FOLLOW))) {
+       if (should_follow_link(path->dentry, nd->flags & LOOKUP_FOLLOW)) {
                if (nd->flags & LOOKUP_RCU) {
                        if (unlikely(nd->path.mnt != path->mnt ||
                                     unlazy_walk(nd, path->dentry))) {
@@ -3057,14 +3055,15 @@ finish_lookup:
                        }
                }
                BUG_ON(inode != path->dentry->d_inode);
-               if (!(nd->flags & LOOKUP_FOLLOW)) {
-                       path_put_conditional(path, nd);
-                       path_put(&nd->path);
-                       return -ELOOP;
-               }
                return 1;
        }
 
+       if (unlikely(d_is_symlink(path->dentry)) && !(open_flag & O_PATH)) {
+               path_to_nameidata(path, nd);
+               error = -ELOOP;
+               goto out;
+       }
+
        if ((nd->flags & LOOKUP_RCU) || nd->path.mnt != path->mnt) {
                path_to_nameidata(path, nd);
        } else {