From: Dennis Yang Date: Fri, 26 Jun 2015 14:25:48 +0000 (+0100) Subject: dm btree remove: fix bug in redistribute3 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=4c7e309340ff85072e96f529582d159002c36734;p=linux-beck.git dm btree remove: fix bug in redistribute3 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 Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org --- diff --git a/drivers/md/persistent-data/dm-btree-remove.c b/drivers/md/persistent-data/dm-btree-remove.c index e04cfd2d60ef..9836c0ae897c 100644 --- 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_btree_info *info, struct btree_node *parent, 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_btree_info *info, struct btree_node *parent, 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