commit 288b3271d920c9ba949c3bab0f749f4cecc70e09 upstream.
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: a805a4fa4fa3 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a805a4fa4fa376bbc145762bb8b09caa2fa8af48 ]
Per ZBC and ZAC specifications, host-managed SMR hard-disks mandate that
all writes into sequential write required zones be aligned to the device
physical block size. However, NVMe ZNS does not have this constraint and
allows write operations into sequential zones to be aligned to the
device logical block size. This inconsistency does not help with
software portability across device types.
To solve this, introduce the zone_write_granularity queue limit to
indicate the alignment constraint, in bytes, of write operations into
zones of a zoned block device. This new limit is exported as a
read-only sysfs queue attribute and the helper
blk_queue_zone_write_granularity() introduced for drivers to set this
limit.
The function blk_queue_set_zoned() is modified to set this new limit to
the device logical block size by default. NVMe ZNS devices as well as
zoned nullb devices use this default value as is. The scsi disk driver
is modified to execute the blk_queue_zone_write_granularity() helper to
set the zone write granularity of host-managed SMR disks to the disk
physical block size.
The accessor functions queue_zone_write_granularity() and
bdev_zone_write_granularity() are also introduced.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@edc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: c8f6f88d2592 ("block: Clear zone limits for a non-zoned stacked queue")
Signed-off-by: Sasha Levin <sashal@kernel.org>
