Commit 288b3271 authored Mar 06, 2023 by Shin'ichiro Kawasaki Committed by Martin K. Petersen Mar 06, 2023

scsi: sd: Fix wrong zone_write_granularity value during revalidate

When the sd driver revalidates host-managed SMR disks, it calls
disk_set_zoned() which changes the zone_write_granularity attribute value
to the logical block size regardless of the device type. After that, the sd
driver overwrites the value in sd_zbc_read_zone() with the physical block
size, since ZBC/ZAC requires this for host-managed disks. Between the calls
to disk_set_zoned() and sd_zbc_read_zone(), there exists a window where the
attribute shows the logical block size as the zone_write_granularity value,
which is wrong for host-managed disks. The duration of the window is from
20ms to 200ms, depending on report zone command execution time.

To avoid the wrong zone_write_granularity value between disk_set_zoned()
and sd_zbc_read_zone(), modify the value not in sd_zbc_read_zone() but
just after disk_set_zoned() call.

Fixes: a805a4fa ("block: introduce zone_write_granularity limit")
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/r/20230306063024.3376959-1-shinichiro.kawasaki@wdc.com

Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

parent 11d9874c

drivers/scsi/sd.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -2988,8 +2988,13 @@ static void sd_read_block_characteristics(struct scsi_disk *sdkp)
		}

		if (sdkp->device->type == TYPE_ZBC) {
		/* Host-managed */
		/*
		* Host-managed: Per ZBC and ZAC specifications, writes in
		* sequential write required zones of host-managed devices must
		* be aligned to the device physical block size.
		*/
		disk_set_zoned(sdkp->disk, BLK_ZONED_HM);
		blk_queue_zone_write_granularity(q, sdkp->physical_block_size);
		} else {
		sdkp->zoned = zoned;
		if (sdkp->zoned == 1) {

drivers/scsi/sd_zbc.c

+0 −8

Original line number	Diff line number	Diff line
		@@ -965,14 +965,6 @@ int sd_zbc_read_zones(struct scsi_disk *sdkp, u8 buf[SD_BUF_SIZE])
		disk_set_max_active_zones(disk, 0);
		nr_zones = round_up(sdkp->capacity, zone_blocks) >> ilog2(zone_blocks);

		/*
		* Per ZBC and ZAC specifications, writes in sequential write required
		* zones of host-managed devices must be aligned to the device physical
		* block size.
		*/
		if (blk_queue_zoned_model(q) == BLK_ZONED_HM)
		blk_queue_zone_write_granularity(q, sdkp->physical_block_size);

		sdkp->early_zone_info.nr_zones = nr_zones;
		sdkp->early_zone_info.zone_blocks = zone_blocks;