[PATCH 0/2] Cleanup sd_zbc zone checks.

[PATCH 0/2] Cleanup sd_zbc zone checks.

[Damien Le Moal]

A couple of small patches to cleanup sd_zbc zone checks formerly
implemented in sd_zbc_check_zones() and now moved to the block layer as
generic code. The first patch removes a superfluous check present in the
block layer. The second patch renames sd_zbc_check_zones() to be clear
about the function role.

Damien Le Moal (2):
  scsi: sd_zbc: Simplify sd_zbc_check_zones()
  scsi: sd_zbc: Rename sd_zbc_check_zones()

 drivers/scsi/sd_zbc.c | 38 +++++++++++++-------------------------
 1 file changed, 13 insertions(+), 25 deletions(-)

-- 
2.23.0

[PATCH 1/2] scsi: sd_zbc: Simplify sd_zbc_check_zones()

[Damien Le Moal]

Now that the block layer generic zone revalidation code in
blk_revalidate_disk_zones() checks for power of 2 zone size, there is
no need to do it in sd_zbc_check_zones(). Remove this check.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
---
 drivers/scsi/sd_zbc.c | 15 ++-------------
 1 file changed, 2 insertions(+), 13 deletions(-)

diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
index e0bd4cf17230..aca6367ced06 100644
--- a/drivers/scsi/sd_zbc.c
+++ b/drivers/scsi/sd_zbc.c
@@ -325,14 +325,11 @@ static int sd_zbc_check_zoned_characteristics(struct scsi_disk *sdkp,
 }
 
 /**
- * sd_zbc_check_zones - Check the device capacity and zone sizes
+ * sd_zbc_check_zones - Check the device capacity and zone size
  * @sdkp: Target disk
  *
  * Check that the device capacity as reported by READ CAPACITY matches the
- * max_lba value (plus one)of the report zones command reply. Also check that
- * all zones of the device have an equal size, only allowing the last zone of
- * the disk to have a smaller size (runt zone). The zone size must also be a
- * power of two.
+ * max_lba value (plus one)of the report zones command reply.
  *
  * Returns the zone size in number of blocks upon success or an error code
  * upon failure.
@@ -366,14 +363,6 @@ static int sd_zbc_check_zones(struct scsi_disk *sdkp, unsigned char *buf,
 	/* Parse REPORT ZONES header */
 	rec = buf + 64;
 	zone_blocks = get_unaligned_be64(&rec[8]);
-	if (!zone_blocks || !is_power_of_2(zone_blocks)) {
-		if (sdkp->first_scan)
-			sd_printk(KERN_NOTICE, sdkp,
-				  "Devices with non power of 2 zone "
-				  "size are not supported\n");
-		return -ENODEV;
-	}
-
 	if (logical_to_sectors(sdkp->device, zone_blocks) > UINT_MAX) {
 		if (sdkp->first_scan)
 			sd_printk(KERN_NOTICE, sdkp,
-- 
2.23.0

[PATCH 2/2] scsi: sd_zbc: Rename sd_zbc_check_zones()

[Damien Le Moal]

Now that the block layer implement zone checks on revalidate,
sd_zbc_check_zones() is reduced getting the zone size and verifying the
device capacity for device with RC_BASIS=0. Be clear about this by
renaming sd_zbc_check_zones() to sd_zbc_check_capacity() and updating
the function description and comments.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
---
 drivers/scsi/sd_zbc.c | 27 +++++++++++++--------------
 1 file changed, 13 insertions(+), 14 deletions(-)

diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
index aca6367ced06..e4282bce5834 100644
--- a/drivers/scsi/sd_zbc.c
+++ b/drivers/scsi/sd_zbc.c
@@ -325,19 +325,21 @@ static int sd_zbc_check_zoned_characteristics(struct scsi_disk *sdkp,
 }
 
 /**
- * sd_zbc_check_zones - Check the device capacity and zone size
+ * sd_zbc_check_capacity - Check the device capacity
  * @sdkp: Target disk
+ * @buf: command buffer
+ * @zblock: zone size in number of blocks
  *
- * Check that the device capacity as reported by READ CAPACITY matches the
- * max_lba value (plus one)of the report zones command reply.
+ * Get the device zone size and check that the device capacity as reported
+ * by READ CAPACITY matches the max_lba value (plus one) of the report zones
+ * command reply for devices with RC_BASIS == 0.
  *
- * Returns the zone size in number of blocks upon success or an error code
- * upon failure.
+ * Returns 0 upon success or an error code upon failure.
  */
-static int sd_zbc_check_zones(struct scsi_disk *sdkp, unsigned char *buf,
-			      u32 *zblocks)
+static int sd_zbc_check_capacity(struct scsi_disk *sdkp, unsigned char *buf,
+				 u32 *zblocks)
 {
-	u64 zone_blocks = 0;
+	u64 zone_blocks;
 	sector_t max_lba;
 	unsigned char *rec;
 	int ret;
@@ -360,7 +362,7 @@ static int sd_zbc_check_zones(struct scsi_disk *sdkp, unsigned char *buf,
 		}
 	}
 
-	/* Parse REPORT ZONES header */
+	/* Get the size of the first reported zone */
 	rec = buf + 64;
 	zone_blocks = get_unaligned_be64(&rec[8]);
 	if (logical_to_sectors(sdkp->device, zone_blocks) > UINT_MAX) {
@@ -394,11 +396,8 @@ int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buf)
 	if (ret)
 		goto err;
 
-	/*
-	 * Check zone size: only devices with a constant zone size (except
-	 * an eventual last runt zone) that is a power of 2 are supported.
-	 */
-	ret = sd_zbc_check_zones(sdkp, buf, &zone_blocks);
+	/* Check the device capacity reported by report zones */
+	ret = sd_zbc_check_capacity(sdkp, buf, &zone_blocks);
 	if (ret != 0)
 		goto err;
 
-- 
2.23.0

Re: [PATCH 0/2] Cleanup sd_zbc zone checks.

[Martin K. Petersen]

Damien,

> A couple of small patches to cleanup sd_zbc zone checks formerly
> implemented in sd_zbc_check_zones() and now moved to the block layer as
> generic code. The first patch removes a superfluous check present in the
> block layer. The second patch renames sd_zbc_check_zones() to be clear
> about the function role.

Applied to 5.6/scsi-queue, thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering