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| author | Damien Le Moal <damien.lemoal@wdc.com> | 2021-01-28 05:47:30 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-02-10 15:44:40 +0100 |
| commit | a805a4fa4fa376bbc145762bb8b09caa2fa8af48 (patch) | |
| tree | 214b6eeff827c08180785b7814b7a2b8c99d6386 /block/blk-sysfs.c | |
| parent | block: use blk_queue_set_zoned in add_partition() (diff) | |
| download | linux-a805a4fa4fa376bbc145762bb8b09caa2fa8af48.tar.xz linux-a805a4fa4fa376bbc145762bb8b09caa2fa8af48.zip | |
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 'block/blk-sysfs.c')
| -rw-r--r-- | block/blk-sysfs.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index b513f1683af0..ae39c7f3d83d 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -219,6 +219,12 @@ static ssize_t queue_write_zeroes_max_show(struct request_queue *q, char *page) (unsigned long long)q->limits.max_write_zeroes_sectors << 9); } +static ssize_t queue_zone_write_granularity_show(struct request_queue *q, + char *page) +{ + return queue_var_show(queue_zone_write_granularity(q), page); +} + static ssize_t queue_zone_append_max_show(struct request_queue *q, char *page) { unsigned long long max_sectors = q->limits.max_zone_append_sectors; @@ -585,6 +591,7 @@ QUEUE_RO_ENTRY(queue_discard_zeroes_data, "discard_zeroes_data"); QUEUE_RO_ENTRY(queue_write_same_max, "write_same_max_bytes"); QUEUE_RO_ENTRY(queue_write_zeroes_max, "write_zeroes_max_bytes"); QUEUE_RO_ENTRY(queue_zone_append_max, "zone_append_max_bytes"); +QUEUE_RO_ENTRY(queue_zone_write_granularity, "zone_write_granularity"); QUEUE_RO_ENTRY(queue_zoned, "zoned"); QUEUE_RO_ENTRY(queue_nr_zones, "nr_zones"); @@ -639,6 +646,7 @@ static struct attribute *queue_attrs[] = { &queue_write_same_max_entry.attr, &queue_write_zeroes_max_entry.attr, &queue_zone_append_max_entry.attr, + &queue_zone_write_granularity_entry.attr, &queue_nonrot_entry.attr, &queue_zoned_entry.attr, &queue_nr_zones_entry.attr, |