md/raid0: Atomic write support

Set BLK_FEAT_ATOMIC_WRITES_STACKED to enable atomic writes. All other
stacked device request queue limits should automatically be set properly.
With regards to atomic write max bytes limit, this will be set at
hw_max_sectors and this is limited by the stripe width, which we want.

Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20241118105018.1870052-4-john.g.garry@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index baaf5f8b80ae1c10fc3b80f448f5f40240238b8e..7049ec7fb8eb4449b9e62db6410bf5e97fc6ec57 100644 (file)
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -384,6 +384,7 @@ static int raid0_set_limits(struct mddev *mddev)
        lim.max_write_zeroes_sectors = mddev->chunk_sectors;
        lim.io_min = mddev->chunk_sectors << 9;
        lim.io_opt = lim.io_min * mddev->raid_disks;
+       lim.features |= BLK_FEAT_ATOMIC_WRITES_STACKED;
        err = mddev_stack_rdev_limits(mddev, &lim, MDDEV_STACK_INTEGRITY);
        if (err) {
                queue_limits_cancel_update(mddev->gendisk->queue);