[3.16.y-ckt stable] Patch "dm btree: fix leak of bufio-backed block in btree_split_beneath error path" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    dm btree: fix leak of bufio-backed block in btree_split_beneath error path

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt20.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 7694a33a5bf53fb63c13bae8696c0672f387337e Mon Sep 17 00:00:00 2001
From: Mike Snitzer <snitzer at redhat.com>
Date: Thu, 22 Oct 2015 10:56:40 -0400
Subject: dm btree: fix leak of bufio-backed block in btree_split_beneath error
 path

commit 4dcb8b57df3593dcb20481d9d6cf79d1dc1534be upstream.

btree_split_beneath()'s error path had an outstanding FIXME that speaks
directly to the potential for _not_ cleaning up a previously allocated
bufio-backed block.

Fix this by releasing the previously allocated bufio block using
unlock_block().

Reported-by: Mikulas Patocka <mpatocka at redhat.com>
Signed-off-by: Mike Snitzer <snitzer at redhat.com>
Acked-by: Joe Thornber <thornber at redhat.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/md/persistent-data/dm-btree.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/persistent-data/dm-btree.c b/drivers/md/persistent-data/dm-btree.c
index c7726cebc495..d6e47033b5e0 100644
--- a/drivers/md/persistent-data/dm-btree.c
+++ b/drivers/md/persistent-data/dm-btree.c
@@ -523,7 +523,7 @@ static int btree_split_beneath(struct shadow_spine *s, uint64_t key)

 	r = new_block(s->info, &right);
 	if (r < 0) {
-		/* FIXME: put left */
+		unlock_block(s->info, left);
 		return r;
 	}