Damien Le Moal 6b4bb49e34 block: introduce zone_write_granularity limit ... [ Upstream commit a805a4fa4f ] 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: c8f6f88d25 ("block: Clear zone limits for a non-zoned stacked queue") Signed-off-by: Sasha Levin <sashal@kernel.org>		2024-04-13 12:58:07 +02:00
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bfq-iosched.rst	…
biodoc.rst	It's been a busy cycle for documentation - hopefully the busiest for a	2020-08-04 22:47:54 -07:00
biovecs.rst	…
blk-mq.rst	docs: block: blk-mq.rst: get rid of :c:type	2020-10-15 07:49:43 +02:00
capability.rst	…
cmdline-partition.rst	…
data-integrity.rst	…
deadline-iosched.rst	…
index.rst	…
inline-encryption.rst	docs: get rid of :c:type explicit declarations for structs	2020-10-15 07:49:40 +02:00
ioprio.rst	…
kyber-iosched.rst	…
null_blk.rst	…
pr.rst	…
queue-sysfs.rst	block: introduce zone_write_granularity limit	2024-04-13 12:58:07 +02:00
request.rst	…
stat.rst	…
switching-sched.rst	…
writeback_cache_control.rst	…