Patch "dm raid: fix false positive for requeue needed during reshape" has been added to the 4.19-stable tree

Patch "dm raid: fix false positive for requeue needed during reshape" has been added to the 4.19-stable tree

[Sasha Levin]

This is a note to let you know that I've just added the patch titled

    dm raid: fix false positive for requeue needed during reshape

to the 4.19-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-false-positive-for-requeue-needed-during.patch
and it can be found in the queue-4.19 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.



commit 68a5e24e3ed59d8e222cf19768e374b3c816031c
Author: Ming Lei <ming.lei@redhat.com>
Date:   Mon Mar 11 13:42:55 2024 -0400

    dm raid: fix false positive for requeue needed during reshape
    
    [ 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@gmail.com>
    Signed-off-by: Ming Lei <ming.lei@redhat.com>
    Signed-off-by: Mike Snitzer <snitzer@kernel.org>
    Signed-off-by: Sasha Levin <sashal@kernel.org>

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);