Patch "dm btree remove: fix bug in redistribute3" has been added to the 3.14-stable tree

Patch "dm btree remove: fix bug in redistribute3" has been added to the 3.14-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    dm btree remove: fix bug in redistribute3

to the 3.14-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     dm-btree-remove-fix-bug-in-redistribute3.patch
and it can be found in the queue-3.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 4c7e309340ff85072e96f529582d159002c36734 Mon Sep 17 00:00:00 2001
From: Dennis Yang <shinrairis@gmail.com>
Date: Fri, 26 Jun 2015 15:25:48 +0100
Subject: dm btree remove: fix bug in redistribute3

From: Dennis Yang <shinrairis@gmail.com>

commit 4c7e309340ff85072e96f529582d159002c36734 upstream.

redistribute3() shares entries out across 3 nodes.  Some entries were
being moved the wrong way, breaking the ordering.  This manifested as a
BUG() in dm-btree-remove.c:shift() when entries were removed from the
btree.

For additional context see:
https://www.redhat.com/archives/dm-devel/2015-May/msg00113.html

Signed-off-by: Dennis Yang <shinrairis@gmail.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/md/persistent-data/dm-btree-remove.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/md/persistent-data/dm-btree-remove.c
+++ b/drivers/md/persistent-data/dm-btree-remove.c
@@ -309,8 +309,8 @@ static void redistribute3(struct dm_btre
 
 		if (s < 0 && nr_center < -s) {
 			/* not enough in central node */
-			shift(left, center, nr_center);
-			s = nr_center - target;
+			shift(left, center, -nr_center);
+			s += nr_center;
 			shift(left, right, s);
 			nr_right += s;
 		} else
@@ -323,7 +323,7 @@ static void redistribute3(struct dm_btre
 		if (s > 0 && nr_center < s) {
 			/* not enough in central node */
 			shift(center, right, nr_center);
-			s = target - nr_center;
+			s -= nr_center;
 			shift(left, right, s);
 			nr_left -= s;
 		} else


Patches currently in stable-queue which might be from shinrairis@gmail.com are

queue-3.14/dm-btree-remove-fix-bug-in-redistribute3.patch