This is a note to let you know that I've just added the patch titled
dm raid: fix discard limits for raid1 and raid10
to the 5.9-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-raid-fix-discard-limits-for-raid1-and-raid10.patch
and it can be found in the queue-5.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ba4db06d47008d44d789bd54bf849665577a6468
Author: Mike Snitzer <snitzer@xxxxxxxxxx>
Date: Thu Sep 24 13:14:52 2020 -0400
dm raid: fix discard limits for raid1 and raid10
[ Upstream commit e0910c8e4f87bb9f767e61a778b0d9271c4dc512 ]
Block core warned that discard_granularity was 0 for dm-raid with
personality of raid1. Reason is that raid_io_hints() was incorrectly
special-casing raid1 rather than raid0.
But since commit 29efc390b9462 ("md/md0: optimize raid0 discard
handling") even raid0 properly handles large discards.
Fix raid_io_hints() by removing discard limits settings for raid1.
Also, fix limits for raid10 by properly stacking underlying limits as
done in blk_stack_limits().
Depends-on: 29efc390b9462 ("md/md0: optimize raid0 discard handling")
Fixes: 61697a6abd24a ("dm: eliminate 'split_discard_bios' flag from DM target interface")
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Zdenek Kabelac <zkabelac@xxxxxxxxxx>
Reported-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 8d2b835d7a108..b45232f9b5c6c 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -3730,12 +3730,14 @@ static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
blk_limits_io_opt(limits, chunk_size_bytes * mddev_data_stripes(rs));
/*
- * RAID1 and RAID10 personalities require bio splitting,
- * RAID0/4/5/6 don't and process large discard bios properly.
+ * RAID10 personality requires bio splitting,
+ * RAID0/1/4/5/6 don't and process large discard bios properly.
*/
- if (rs_is_raid1(rs) || rs_is_raid10(rs)) {
- limits->discard_granularity = chunk_size_bytes;
- limits->max_discard_sectors = rs->md.chunk_sectors;
+ if (rs_is_raid10(rs)) {
+ limits->discard_granularity = max(chunk_size_bytes,
+ limits->discard_granularity);
+ limits->max_discard_sectors = min_not_zero(rs->md.chunk_sectors,
+ limits->max_discard_sectors);
}
}
