| 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 |
