diff options
| author | Damien Le Moal <damien.lemoal@wdc.com> | 2021-01-28 13:47:30 +0900 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-02-10 07:44:40 -0700 |
| commit | a805a4fa4fa376bbc145762bb8b09caa2fa8af48 (patch) | |
| tree | 214b6eeff827c08180785b7814b7a2b8c99d6386 /include/linux/blkdev.h | |
| parent | eafc63a9f78e315e7a93c455859b776713da8b69 (diff) | |
block: introduce zone_write_granularity limit
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>
Diffstat (limited to 'include/linux/blkdev.h')
| -rw-r--r-- | include/linux/blkdev.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 0dea268bd61b..9149f4a5adb3 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -337,6 +337,7 @@ struct queue_limits { unsigned int max_zone_append_sectors; unsigned int discard_granularity; unsigned int discard_alignment; + unsigned int zone_write_granularity; unsigned short max_segments; unsigned short max_integrity_segments; @@ -1160,6 +1161,8 @@ extern void blk_queue_logical_block_size(struct request_queue *, unsigned int); extern void blk_queue_max_zone_append_sectors(struct request_queue *q, unsigned int max_zone_append_sectors); extern void blk_queue_physical_block_size(struct request_queue *, unsigned int); +void blk_queue_zone_write_granularity(struct request_queue *q, + unsigned int size); extern void blk_queue_alignment_offset(struct request_queue *q, unsigned int alignment); void blk_queue_update_readahead(struct request_queue *q); @@ -1473,6 +1476,18 @@ static inline int bdev_io_opt(struct block_device *bdev) return queue_io_opt(bdev_get_queue(bdev)); } +static inline unsigned int +queue_zone_write_granularity(const struct request_queue *q) +{ + return q->limits.zone_write_granularity; +} + +static inline unsigned int +bdev_zone_write_granularity(struct block_device *bdev) +{ + return queue_zone_write_granularity(bdev_get_queue(bdev)); +} + static inline int queue_alignment_offset(const struct request_queue *q) { if (q->limits.misaligned) |