From cc07d72bf350b77faeffee1c37bc52197171473f 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
Git-commit: cc07d72bf350b77faeffee1c37bc52197171473f
Patch-mainline: v5.11-rc4
References: git-fixes

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.

Fix raid_io_hints() by removing discard limits settings for
raid1. Check for raid0 instead.

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>
Reported-by: Stephan Bärwolf <stephan@matrixstorm.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Coly Li <colyli@suse.de>

---
 drivers/md/dm-raid.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 23c38777e8f6..cab12b2251ba 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -3729,10 +3729,10 @@ 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.
+	 * RAID0 and RAID10 personalities require bio splitting,
+	 * RAID1/4/5/6 don't and process large discard bios properly.
 	 */
-	if (rs_is_raid1(rs) || rs_is_raid10(rs)) {
+	if (rs_is_raid0(rs) || rs_is_raid10(rs)) {
 		limits->discard_granularity = chunk_size_bytes;
 		limits->max_discard_sectors = rs->md.chunk_sectors;
 	}
-- 
2.26.2