[v3,16/30] ublk_drv: Do not request ELEVATOR_F_ZBD_SEQ_WRITE elevator feature

Commit Message

Damien Le Moal March 28, 2024, 12:43 a.m. UTC

With zone write plugging enabled at the block layer level, any zone
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 ublk device with any
scheduler, including "none".

Signed-off-by: Damien Le Moal <[e-mail]>
Reviewed-by: Hannes Reinecke <[e-mail]>
---
 drivers/block/ublk_drv.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

Comments

Christoph Hellwig March 28, 2024, 4:50 a.m. UTC | #1

Looks good:

Reviewed-by: Christoph Hellwig <[e-mail]>

Bart Van Assche March 29, 2024, 9:28 p.m. UTC | #2

Reviewed-by: Bart Van Assche <[e-mail]>

Patch

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index bea3d5cf8a83..ab6af84e327c 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -249,8 +249,7 @@  static int ublk_dev_param_zoned_validate(const struct ublk_device *ub)
 static void ublk_dev_param_zoned_apply(struct ublk_device *ub)
 {
 	blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, ub->ub_disk->queue);
-	blk_queue_required_elevator_features(ub->ub_disk->queue,
-					     ELEVATOR_F_ZBD_SEQ_WRITE);
+
 	ub->ub_disk->nr_zones = ublk_get_nr_zones(ub);
 }