From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sun, 10 May 2015 14:50:41 +0000 (-0400)
Subject: namei: simpler treatment of symlinks with nothing other that / in the body
X-Git-Tag: firefly_0821_release~176^2~1459^2~83
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=4f697a5e173023a4f566339452a9d6f2cc7bd7dc;p=firefly-linux-kernel-4.4.55.git

namei: simpler treatment of symlinks with nothing other that / in the body

Instead of saving name and branching to OK:, where we'll immediately restore
it, and call walk_component() with WALK_PUT|WALK_GET and nd->last_type being
LAST_BIND, which is equivalent to put_link(nd), err = 0, we can just treat
that the same way we'd treat procfs-style "jump" symlinks - do put_link(nd)
and move on.

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

diff --git a/fs/namei.c b/fs/namei.c
index 678aeef85490..c5eb77a57974 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1865,11 +1865,13 @@ OK:
 						;
 				}
 				nd->inode = nd->path.dentry->d_inode;
-				nd->stack[nd->depth - 1].name = name;
-				if (!*s)
-					goto OK;
-				name = s;
-				continue;
+				if (unlikely(!*s)) {
+					put_link(nd);
+				} else {
+					nd->stack[nd->depth - 1].name = name;
+					name = s;
+					continue;
+				}
 			}
 		}
 		if (!d_can_lookup(nd->path.dentry)) {