[PATCH v3 1/5] scsi: sd_zbc: Set zone limits before revalidating zones

[Damien Le Moal]

In sd_zbc_revalidate_zones(), execute blk_queue_chunk_sectors() and
blk_queue_max_zone_append_sectors() to respectively set a ZBC device
zone size and maximum zone append sector limit before executing
blk_revalidate_disk_zones(). This is to allow the block layer zone
reavlidation to check these device characteristics prior to checking all
zones of the device.

Since blk_queue_max_zone_append_sectors() already caps the device
maximum zone append limit to the zone size and to the maximum command
size, the max_append value passed to blk_queue_max_zone_append_sectors()
is simplified to the maximum number of segments times the number of
sectors per page.

Signed-off-by: Damien Le Moal <dlemoal at kernel.org>
Reviewed-by: Bart Van Assche <bvanassche at acm.org>
---
 drivers/scsi/sd_zbc.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
index abbd08933ac7..a25215507668 100644
--- a/drivers/scsi/sd_zbc.c
+++ b/drivers/scsi/sd_zbc.c
@@ -831,7 +831,6 @@ int sd_zbc_revalidate_zones(struct scsi_disk *sdkp)
 	struct request_queue *q = disk->queue;
 	u32 zone_blocks = sdkp->early_zone_info.zone_blocks;
 	unsigned int nr_zones = sdkp->early_zone_info.nr_zones;
-	u32 max_append;
 	int ret = 0;
 	unsigned int flags;
 
@@ -876,6 +875,11 @@ int sd_zbc_revalidate_zones(struct scsi_disk *sdkp)
 		goto unlock;
 	}
 
+	blk_queue_chunk_sectors(q,
+			logical_to_sectors(sdkp->device, zone_blocks));
+	blk_queue_max_zone_append_sectors(q,
+			q->limits.max_segments << PAGE_SECTORS_SHIFT);
+
 	ret = blk_revalidate_disk_zones(disk, sd_zbc_revalidate_zones_cb);
 
 	memalloc_noio_restore(flags);
@@ -888,12 +892,6 @@ int sd_zbc_revalidate_zones(struct scsi_disk *sdkp)
 		goto unlock;
 	}
 
-	max_append = min_t(u32, logical_to_sectors(sdkp->device, zone_blocks),
-			   q->limits.max_segments << PAGE_SECTORS_SHIFT);
-	max_append = min_t(u32, max_append, queue_max_hw_sectors(q));
-
-	blk_queue_max_zone_append_sectors(q, max_append);
-
 	sd_zbc_print_zones(sdkp);
 
 unlock:
-- 
2.41.0