[PATCH 4.19 064/148] dm raid: fix false positive for requeue needed during reshape

[Sasha Levin]

From: Ming Lei <ming.lei@xxxxxxxxxx>

[ Upstream commit b25b8f4b8ecef0f48c05f0c3572daeabefe16526 ]

An empty flush doesn't have a payload, so it should never be looked at
when considering to possibly requeue a bio for the case when a reshape
is in progress.

Fixes: 9dbd1aa3a81c ("dm raid: add reshaping support to the target")
Reported-by: Patrick Plenefisch <simonpatp@xxxxxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/md/dm-raid.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 72aa5097b68ff..1759134fce824 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -3348,14 +3348,14 @@ static int raid_map(struct dm_target *ti, struct bio *bio)
 	struct mddev *mddev = &rs->md;
 
 	/*
-	 * If we're reshaping to add disk(s)), ti->len and
+	 * If we're reshaping to add disk(s), ti->len and
 	 * mddev->array_sectors will differ during the process
 	 * (ti->len > mddev->array_sectors), so we have to requeue
 	 * bios with addresses > mddev->array_sectors here or
 	 * there will occur accesses past EOD of the component
 	 * data images thus erroring the raid set.
 	 */
-	if (unlikely(bio_end_sector(bio) > mddev->array_sectors))
+	if (unlikely(bio_has_data(bio) && bio_end_sector(bio) > mddev->array_sectors))
 		return DM_MAPIO_REQUEUE;
 
 	md_handle_request(mddev, bio);
-- 
2.43.0