lkml.org 
[lkml]   [2015]   [Jul]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.1 116/267] dm btree remove: fix bug in redistribute3
Date
4.1-stable review patch.  If anyone has any objections, please let me know.

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

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



\
 
 \ /
  Last update: 2015-08-01 00:01    [W:0.641 / U:0.076 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site