null_blk: Do not request ELEVATOR_F_ZBD_SEQ_WRITE elevator feature

With zone write plugging enabled at the block layer level, a zoned
device can only ever see at most a single write operation per zone.
There is thus no need to request a block scheduler with strick per-zone
sequential write ordering control through the ELEVATOR_F_ZBD_SEQ_WRITE
feature. Removing this allows using a zoned null_blk device with any
scheduler, including "none".

Signed-off-by: Damien Le Moal <[email protected]>
Reviewed-by: Hannes Reinecke <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Bart Van Assche <[email protected]>
Reviewed-by: Chaitanya Kulkarni <[email protected]>
Tested-by: Hans Holmberg <[email protected]>
Tested-by: Dennis Maisenbacher <[email protected]>
Reviewed-by: Martin K. Petersen <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

1 files changed, 0 insertions, 1 deletions

diff --git a/drivers/block/null_blk/zoned.c b/drivers/block/null_blk/zoned.c
index 1689e2584104..8e217f8fadcd 100644
--- a/drivers/block/null_blk/zoned.c
+++ b/drivers/block/null_blk/zoned.c
@@ -165,7 +165,6 @@ int null_register_zoned_dev(struct nullb *nullb)
 	struct request_queue *q = nullb->q;
 
 	blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q);
-	blk_queue_required_elevator_features(q, ELEVATOR_F_ZBD_SEQ_WRITE);
 	nullb->disk->nr_zones = bdev_nr_zones(nullb->disk->part0);
 	return blk_revalidate_disk_zones(nullb->disk, NULL);
 }