[PATCH 0/2] sd fixes for zoned block devices

[PATCH 0/2] sd fixes for zoned block devices

[Damien Le Moal]

2 small fixes in this series:
(1) Fix sd_read_cache_type so that DPOFUA is not disabled for zoned block
devices supporting it.
(2) Ignore the zoned field of the block device characteristics page for
host-managed zoned block devices as there is no good match defined explicitely
for HM by the standard.

Damien Le Moal (2):
  sd: Fix wrong DPOFUA disable in sd_read_cache_type
  sd: Ignore zoned field for host-managed devices

 drivers/scsi/sd.c | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

-- 
2.9.3

[PATCH 1/2] sd: Fix wrong DPOFUA disable in sd_read_cache_type

[Damien Le Moal]

Zoned block devices force the use of READ/WRITE(16) commands by setting
sdkp->use_16_for_rw and clearing sdkp->use_10_for_rw. This result in
DPOFUA always being disabled for these drives as the assumed use of
the deprecated READ/WRITE(6) commands only looks at sdkp->use_10_for_rw.
Strenghten the test by also checking that sdkp->use_16_for_rw is false.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
---
 drivers/scsi/sd.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index b193304..d7aaacf 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2600,7 +2600,8 @@ sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
 		if (sdp->broken_fua) {
 			sd_first_printk(KERN_NOTICE, sdkp, "Disabling FUA\n");
 			sdkp->DPOFUA = 0;
-		} else if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw) {
+		} else if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw &&
+			   !sdkp->device->use_16_for_rw) {
 			sd_first_printk(KERN_NOTICE, sdkp,
 				  "Uses READ/WRITE(6), disabling FUA\n");
 			sdkp->DPOFUA = 0;
-- 
2.9.3

[PATCH 2/2] sd: Ignore zoned field for host-managed devices

[Damien Le Moal]

There is no good match of the zoned filed of the block device
characteristics page for host-managed devices. For these devices, the
zoning model is derived directly from the device type. So ignore the
zoned field for these drives.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
---
 drivers/scsi/sd.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index d7aaacf..6e6d4a4 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2784,13 +2784,21 @@ static void sd_read_block_characteristics(struct scsi_disk *sdkp)
 		queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, q);
 	}
 
-	sdkp->zoned = (buffer[8] >> 4) & 3;
-	if (sdkp->zoned == 1)
-		q->limits.zoned = BLK_ZONED_HA;
-	else if (sdkp->device->type == TYPE_ZBC)
+	if (sdkp->device->type == TYPE_ZBC) {
+		/* Host-managed */
 		q->limits.zoned = BLK_ZONED_HM;
-	else
-		q->limits.zoned = BLK_ZONED_NONE;
+	} else {
+		sdkp->zoned = (buffer[8] >> 4) & 3;
+		if (sdkp->zoned == 1)
+			/* Host-aware */
+			q->limits.zoned = BLK_ZONED_HA;
+		else
+			/*
+			 * Treat drive-managed devices as
+			 * regular block devices.
+			 */
+			q->limits.zoned = BLK_ZONED_NONE;
+	}
 	if (blk_queue_is_zoned(q) && sdkp->first_scan)
 		sd_printk(KERN_NOTICE, sdkp, "Host-%s zoned block device\n",
 		      q->limits.zoned == BLK_ZONED_HM ? "managed" : "aware");
-- 
2.9.3

Re: [PATCH 1/2] sd: Fix wrong DPOFUA disable in sd_read_cache_type

[Hannes Reinecke]

On 01/12/2017 07:25 AM, Damien Le Moal wrote:
> Zoned block devices force the use of READ/WRITE(16) commands by setting
> sdkp->use_16_for_rw and clearing sdkp->use_10_for_rw. This result in
> DPOFUA always being disabled for these drives as the assumed use of
> the deprecated READ/WRITE(6) commands only looks at sdkp->use_10_for_rw.
> Strenghten the test by also checking that sdkp->use_16_for_rw is false.
>
> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
> ---
>  drivers/scsi/sd.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
> index b193304..d7aaacf 100644
> --- a/drivers/scsi/sd.c
> +++ b/drivers/scsi/sd.c
> @@ -2600,7 +2600,8 @@ sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
>  		if (sdp->broken_fua) {
>  			sd_first_printk(KERN_NOTICE, sdkp, "Disabling FUA\n");
>  			sdkp->DPOFUA = 0;
> -		} else if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw) {
> +		} else if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw &&
> +			   !sdkp->device->use_16_for_rw) {
>  			sd_first_printk(KERN_NOTICE, sdkp,
>  				  "Uses READ/WRITE(6), disabling FUA\n");
>  			sdkp->DPOFUA = 0;
>
Reviewed-by: Hannes Reinecke <hare@suse.com>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		   Teamlead Storage & Networking
hare@suse.de			               +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)

Re: [PATCH 2/2] sd: Ignore zoned field for host-managed devices

[Hannes Reinecke]

On 01/12/2017 07:25 AM, Damien Le Moal wrote:
> There is no good match of the zoned filed of the block device
> characteristics page for host-managed devices. For these devices, the
> zoning model is derived directly from the device type. So ignore the
> zoned field for these drives.
>
> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
> ---
>  drivers/scsi/sd.c | 20 ++++++++++++++------
>  1 file changed, 14 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
> index d7aaacf..6e6d4a4 100644
> --- a/drivers/scsi/sd.c
> +++ b/drivers/scsi/sd.c
> @@ -2784,13 +2784,21 @@ static void sd_read_block_characteristics(struct scsi_disk *sdkp)
>  		queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, q);
>  	}
>
> -	sdkp->zoned = (buffer[8] >> 4) & 3;
> -	if (sdkp->zoned == 1)
> -		q->limits.zoned = BLK_ZONED_HA;
> -	else if (sdkp->device->type == TYPE_ZBC)
> +	if (sdkp->device->type == TYPE_ZBC) {
> +		/* Host-managed */
>  		q->limits.zoned = BLK_ZONED_HM;
> -	else
> -		q->limits.zoned = BLK_ZONED_NONE;
> +	} else {
> +		sdkp->zoned = (buffer[8] >> 4) & 3;
> +		if (sdkp->zoned == 1)
> +			/* Host-aware */
> +			q->limits.zoned = BLK_ZONED_HA;
> +		else
> +			/*
> +			 * Treat drive-managed devices as
> +			 * regular block devices.
> +			 */
> +			q->limits.zoned = BLK_ZONED_NONE;
> +	}
>  	if (blk_queue_is_zoned(q) && sdkp->first_scan)
>  		sd_printk(KERN_NOTICE, sdkp, "Host-%s zoned block device\n",
>  		      q->limits.zoned == BLK_ZONED_HM ? "managed" : "aware");
>
Reviewed-by: Hannes Reinecke <hare@suse.com>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		   Teamlead Storage & Networking
hare@suse.de			               +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)

Re: [PATCH 0/2] sd fixes for zoned block devices

[Martin K. Petersen]

>>>>> "Damien" == Damien Le Moal <damien.lemoal@wdc.com> writes:

Damien> 2 small fixes in this series: (1) Fix sd_read_cache_type so that
Damien> DPOFUA is not disabled for zoned block devices supporting it.
Damien> (2) Ignore the zoned field of the block device characteristics
Damien> page for host-managed zoned block devices as there is no good
Damien> match defined explicitely for HM by the standard.

Damien> Damien Le Moal (2): sd: Fix wrong DPOFUA disable in
Damien> sd_read_cache_type sd: Ignore zoned field for host-managed
Damien> devices

Applied to 4.10/scsi-fixes.

-- 
Martin K. Petersen	Oracle Linux Engineering