From: Ilija Hadzic <ihadzic@research.bell-labs.com>
Date: Tue, 12 Nov 2013 23:11:45 +0000 (-0800)
Subject: devpts: plug the memory leak in kill_sb
X-Git-Tag: v3.4.72~52
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=510e627f364a15db3b0848de1429d15f1473b95e;p=platform%2Fkernel%2Flinux-stable.git

devpts: plug the memory leak in kill_sb

commit 66da0e1f9034140ae2f571ef96e254a25083906c upstream.

When devpts is unmounted, there may be a no-longer-used IDR tree hanging
off the superblock we are about to kill.  This needs to be cleaned up
before destroying the SB.

The leak is usually not a big deal because unmounting devpts is typically
done when shutting down the whole machine.  However, shutting down an LXC
container instead of a physical machine exposes the problem (the garbage
is detectable with kmemleak).

Signed-off-by: Ilija Hadzic <ihadzic@research.bell-labs.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
index 10f5e0b..901c3d7 100644
--- a/fs/devpts/inode.c
+++ b/fs/devpts/inode.c
@@ -475,6 +475,7 @@ static void devpts_kill_sb(struct super_block *sb)
 {
 	struct pts_fs_info *fsi = DEVPTS_SB(sb);
 
+	ida_destroy(&fsi->allocated_ptys);
 	kfree(fsi);
 	kill_litter_super(sb);
 }