[PATCH 5.15 154/317] dm raid: fix false positive for requeue needed during reshape

From: Sasha Levin
Date: Mon Mar 25 2024 - 04:21:14 EST


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 8d489933d5792..04769fb20cf7f 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -3329,14 +3329,14 @@ 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