md/raid10: fix bug which causes all RAID10 reshapes to move no data.
The recent comment:
commit 7e83ccbecd608b971f340e951c9e84cd0343002f
md/raid10: Allow skipping recovery when clean arrays are assembled
Causes raid10 to skip a recovery in certain cases where it is safe to
do so. Unfortunately it also causes a reshape to be skipped which is
never safe. The result is that an attempt to reshape a RAID10 will
appear to complete instantly, but no data will have been moves so the
array will now contain garbage.
(If nothing is written, you can recovery by simple performing the
reverse reshape which will also complete instantly).
Bug was introduced in 3.10, so this is suitable for 3.10-stable.
Cc: stable@vger.kernel.org (3.10)
Cc: Martin Wilck <mwilck@arcor.de>
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 3480bf7c..cd066b6 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -2931,14 +2931,13 @@
*/
if (mddev->bitmap == NULL &&
mddev->recovery_cp == MaxSector &&
+ mddev->reshape_position == MaxSector &&
+ !test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
+ !test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
conf->fullsync == 0) {
*skipped = 1;
- max_sector = mddev->dev_sectors;
- if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
- test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
- max_sector = mddev->resync_max_sectors;
- return max_sector - sector_nr;
+ return mddev->dev_sectors - sector_nr;
}
skipped: