Using the helper blk_queue_required_elevator_features(), set the elevator feature ELEVATOR_F_ZBD_SEQ_WRITE as required for the request queue of null_blk devices created with zoned mode enabled. This feature requirement can always be satisfied as the mq-deadline elevator is always selected for in-kernel compilation when CONFIG_BLK_DEV_ZONED (zoned block device support) is enabled. Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> --- drivers/block/null_blk_main.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c index b26a178d064d..b29b273690b0 100644 --- a/drivers/block/null_blk_main.c +++ b/drivers/block/null_blk_main.c @@ -1695,6 +1695,8 @@ static int null_add_dev(struct nullb_device *dev) blk_queue_chunk_sectors(nullb->q, dev->zone_size_sects); nullb->q->limits.zoned = BLK_ZONED_HM; blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, nullb->q); + blk_queue_required_elevator_features(nullb->q, + ELEVATOR_F_ZBD_SEQ_WRITE); } nullb->q->queuedata = nullb; -- 2.21.0