[PATCH 3.11 113/144] Fix mountpoint reference leakage in linkat

[Luis Henriques]

3.11.10.7 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Oleg Drokin <green at linuxhacker.ru>

commit d22e6338db7f613dd4f6095c190682fcc519e4b7 upstream.

Recent changes to retry on ESTALE in linkat
(commit 442e31ca5a49e398351b2954b51f578353fdf210)
introduced a mountpoint reference leak and a small memory
leak in case a filesystem link operation returns ESTALE
which is pretty normal for distributed filesystems like
lustre, nfs and so on.
Free old_path in such a case.

[AV: there was another missing path_put() nearby - on the previous
goto retry]

Signed-off-by: Oleg Drokin: <green at linuxhacker.ru>
Signed-off-by: Al Viro <viro at zeniv.linux.org.uk>
[ luis: backported to 3.11:
  - dropped AV changes as they are not applicable to 3.11 kernel ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 fs/namei.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/namei.c b/fs/namei.c
index df9946e..b8f1f7f 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3708,6 +3708,7 @@ retry:
 out_dput:
 	done_path_create(&new_path, new_dentry);
 	if (retry_estale(error, how)) {
+		path_put(&old_path);
 		how |= LOOKUP_REVAL;
 		goto retry;
 	}
-- 
1.9.1