Commit d2f526ba authored by Keith Busch's avatar Keith Busch Committed by Jens Axboe
Browse files

block: introduce max_write_streams queue limit 



Drivers with hardware that support write streams need a way to export how
many are available so applications can generically query this.

Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Reviewed-by: default avatarNitesh Shetty <nj.shetty@samsung.com>
Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
[hch: renamed hints to streams, removed stacking]
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarKanchan Joshi <joshi.k@samsung.com>
Link: https://lore.kernel.org/r/20250506121732.8211-4-joshi.k@samsung.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 5006f85e

Documentation/ABI/stable/sysfs-block

+7 −0
Original line number Diff line number Diff line
@@ -547,6 +547,13 @@ Description: 
		[RO] Maximum size in bytes of a single element in a DMA

		scatter/gather list.



What:		/sys/block/<disk>/queue/max_write_streams

Date:		November 2024

Contact:	linux-block@vger.kernel.org

Description:

		[RO] Maximum number of write streams supported, 0 if not

		supported. If supported, valid values are 1 through

		max_write_streams, inclusive.



What:		/sys/block/<disk>/queue/max_segments

Date:		March 2010

block/blk-sysfs.c

+3 −0
Original line number Diff line number Diff line
@@ -134,6 +134,7 @@ QUEUE_SYSFS_LIMIT_SHOW(max_segments) 
QUEUE_SYSFS_LIMIT_SHOW(max_discard_segments)

QUEUE_SYSFS_LIMIT_SHOW(max_integrity_segments)

QUEUE_SYSFS_LIMIT_SHOW(max_segment_size)

QUEUE_SYSFS_LIMIT_SHOW(max_write_streams)

QUEUE_SYSFS_LIMIT_SHOW(logical_block_size)

QUEUE_SYSFS_LIMIT_SHOW(physical_block_size)

QUEUE_SYSFS_LIMIT_SHOW(chunk_sectors)
@@ -488,6 +489,7 @@ QUEUE_LIM_RO_ENTRY(queue_max_hw_sectors, "max_hw_sectors_kb"); 
QUEUE_LIM_RO_ENTRY(queue_max_segments, "max_segments");

QUEUE_LIM_RO_ENTRY(queue_max_integrity_segments, "max_integrity_segments");

QUEUE_LIM_RO_ENTRY(queue_max_segment_size, "max_segment_size");

QUEUE_LIM_RO_ENTRY(queue_max_write_streams, "max_write_streams");

QUEUE_RW_ENTRY(elv_iosched, "scheduler");



QUEUE_LIM_RO_ENTRY(queue_logical_block_size, "logical_block_size");
@@ -642,6 +644,7 @@ static struct attribute *queue_attrs[] = { 
	&queue_max_discard_segments_entry.attr,

	&queue_max_integrity_segments_entry.attr,

	&queue_max_segment_size_entry.attr,

	&queue_max_write_streams_entry.attr,

	&queue_hw_sector_size_entry.attr,

	&queue_logical_block_size_entry.attr,

	&queue_physical_block_size_entry.attr,

include/linux/blkdev.h

+9 −0
Original line number Diff line number Diff line
@@ -404,6 +404,8 @@ struct queue_limits { 
	unsigned short		max_integrity_segments;

	unsigned short		max_discard_segments;



	unsigned short		max_write_streams;



	unsigned int		max_open_zones;

	unsigned int		max_active_zones;
@@ -1270,6 +1272,13 @@ static inline unsigned int bdev_max_segments(struct block_device *bdev) 
	return queue_max_segments(bdev_get_queue(bdev));

}



static inline unsigned short bdev_max_write_streams(struct block_device *bdev)

{

	if (bdev_is_partition(bdev))

		return 0;

	return bdev_limits(bdev)->max_write_streams;

}



static inline unsigned queue_logical_block_size(const struct request_queue *q)

{

	return q->limits.logical_block_size;