[PATCH v14 11/19] scsi: sd_zbc: Only require an I/O scheduler if needed

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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)
+		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



[Index of Archives]     [Linux RAID]     [Linux SCSI]     [Linux ATA RAID]     [IDE]     [Linux Wireless]     [Linux Kernel]     [ATH6KL]     [Linux Bluetooth]     [Linux Netdev]     [Kernel Newbies]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Device Mapper]

  Powered by Linux