On 10/19/23 02:54, Bart Van Assche wrote: > An I/O scheduler that serializes zoned writes is only needed if the SCSI > LLD does not preserve the write order. Hence only set > ELEVATOR_F_ZBD_SEQ_WRITE if the LLD does not preserve the write order. > > Reviewed-by: Damien Le Moal <dlemoal@xxxxxxxxxx> > Cc: Martin K. Petersen <martin.petersen@xxxxxxxxxx> > Cc: Christoph Hellwig <hch@xxxxxx> > Cc: Ming Lei <ming.lei@xxxxxxxxxx> > Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx> > --- > drivers/scsi/sd_zbc.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c > index a25215507668..718b31bed878 100644 > --- a/drivers/scsi/sd_zbc.c > +++ b/drivers/scsi/sd_zbc.c > @@ -955,7 +955,9 @@ int sd_zbc_read_zones(struct scsi_disk *sdkp, u8 buf[SD_BUF_SIZE]) > > /* The drive satisfies the kernel restrictions: set it up */ > blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q); > - blk_queue_required_elevator_features(q, ELEVATOR_F_ZBD_SEQ_WRITE); > + if (!q->limits.driver_preserves_write_order) Where is this limit introduced ? I do not see it anywhere in your patches. Did I miss something ? > + blk_queue_required_elevator_features(q, > + ELEVATOR_F_ZBD_SEQ_WRITE); > if (sdkp->zones_max_open == U32_MAX) > disk_set_max_open_zones(disk, 0); > else -- Damien Le Moal Western Digital Research