From e0910c8e4f87bb9f767e61a778b0d9271c4dc512 Mon Sep 17 00:00:00 2001
From: Mike Snitzer <snitzer@redhat.com>
Date: Thu, 24 Sep 2020 13:14:52 -0400
Subject: [PATCH] dm raid: fix discard limits for raid1 and raid10
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@vger.kernel.org
Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
---
drivers/md/dm-raid.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 56b723d012ac1..dc8568ab96f24 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);
}
}
--
GitLab