Commit 559218d4 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: pre-calculate max_zone_append_sectors 



max_zone_append_sectors differs from all other queue limits in that the
final value used is not stored in the queue_limits but needs to be
obtained using queue_limits_max_zone_append_sectors helper.  This not
only adds (tiny) extra overhead to the I/O path, but also can be easily
forgotten in file system code.

Add a new max_hw_zone_append_sectors value to queue_limits which is
set by the driver, and calculate max_zone_append_sectors from that and
the other inputs in blk_validate_zoned_limits, similar to how
max_sectors is calculated to fix this.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20241104073955.112324-3-hch@lst.de


Reviewed-by: default avatarDamien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20241108154657.845768-2-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 0ef2b9e6

block/blk-core.c

+1 −1
Original line number Diff line number Diff line
@@ -607,7 +607,7 @@ static inline blk_status_t blk_check_zone_append(struct request_queue *q, 
		return BLK_STS_IOERR;



	/* Make sure the BIO is small enough and will not get split */

	if (nr_sectors > queue_max_zone_append_sectors(q))

	if (nr_sectors > q->limits.max_zone_append_sectors)

		return BLK_STS_IOERR;



	bio->bi_opf |= REQ_NOMERGE;

block/blk-merge.c

+1 −2
Original line number Diff line number Diff line
@@ -392,11 +392,10 @@ struct bio *bio_split_rw(struct bio *bio, const struct queue_limits *lim, 
struct bio *bio_split_zone_append(struct bio *bio,

		const struct queue_limits *lim, unsigned *nr_segs)

{

	unsigned int max_sectors = queue_limits_max_zone_append_sectors(lim);

	int split_sectors;



	split_sectors = bio_split_rw_at(bio, lim, nr_segs,

			max_sectors << SECTOR_SHIFT);

			lim->max_zone_append_sectors << SECTOR_SHIFT);

	if (WARN_ON_ONCE(split_sectors > 0))

		split_sectors = -EINVAL;

	return bio_submit_split(bio, split_sectors);

block/blk-settings.c

+13 −14
Original line number Diff line number Diff line
@@ -50,7 +50,7 @@ void blk_set_stacking_limits(struct queue_limits *lim) 
	lim->max_sectors = UINT_MAX;

	lim->max_dev_sectors = UINT_MAX;

	lim->max_write_zeroes_sectors = UINT_MAX;

	lim->max_zone_append_sectors = UINT_MAX;

	lim->max_hw_zone_append_sectors = UINT_MAX;

	lim->max_user_discard_sectors = UINT_MAX;

}

EXPORT_SYMBOL(blk_set_stacking_limits);
@@ -91,17 +91,16 @@ static int blk_validate_zoned_limits(struct queue_limits *lim) 
	if (lim->zone_write_granularity < lim->logical_block_size)

		lim->zone_write_granularity = lim->logical_block_size;



	if (lim->max_zone_append_sectors) {

	/*

		 * The Zone Append size is limited by the maximum I/O size

		 * and the zone size given that it can't span zones.

	 * The Zone Append size is limited by the maximum I/O size and the zone

	 * size given that it can't span zones.

	 *

	 * If no max_hw_zone_append_sectors limit is provided, the block layer

	 * will emulated it, else we're also bound by the hardware limit.

	 */

	lim->max_zone_append_sectors =

			min3(lim->max_hw_sectors,

			     lim->max_zone_append_sectors,

			     lim->chunk_sectors);

	}



		min_not_zero(lim->max_hw_zone_append_sectors,

			min(lim->chunk_sectors, lim->max_hw_sectors));

	return 0;

}
@@ -527,8 +526,8 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, 
	t->max_dev_sectors = min_not_zero(t->max_dev_sectors, b->max_dev_sectors);

	t->max_write_zeroes_sectors = min(t->max_write_zeroes_sectors,

					b->max_write_zeroes_sectors);

	t->max_zone_append_sectors = min(queue_limits_max_zone_append_sectors(t),

					 queue_limits_max_zone_append_sectors(b));

	t->max_hw_zone_append_sectors = min(t->max_hw_zone_append_sectors,

					b->max_hw_zone_append_sectors);



	t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask,

					    b->seg_boundary_mask);

block/blk-sysfs.c

+3 −14
Original line number Diff line number Diff line
@@ -131,6 +131,7 @@ QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_BYTES(max_hw_discard_sectors) 
QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_BYTES(max_write_zeroes_sectors)

QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_BYTES(atomic_write_max_sectors)

QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_BYTES(atomic_write_boundary_sectors)

QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_BYTES(max_zone_append_sectors)



#define QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_KB(_field)			\

static ssize_t queue_##_field##_show(struct gendisk *disk, char *page)	\
@@ -178,18 +179,6 @@ static ssize_t queue_max_discard_sectors_store(struct gendisk *disk, 
	return ret;

}



/*

 * For zone append queue_max_zone_append_sectors does not just return the

 * underlying queue limits, but actually contains a calculation.  Because of

 * that we can't simply use QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_BYTES here.

 */

static ssize_t queue_zone_append_max_show(struct gendisk *disk, char *page)

{

	return sprintf(page, "%llu\n",

		(u64)queue_max_zone_append_sectors(disk->queue) <<

			SECTOR_SHIFT);

}



static ssize_t

queue_max_sectors_store(struct gendisk *disk, const char *page, size_t count)

{
@@ -479,7 +468,7 @@ QUEUE_RO_ENTRY(queue_atomic_write_unit_min, "atomic_write_unit_min_bytes"); 


QUEUE_RO_ENTRY(queue_write_same_max, "write_same_max_bytes");

QUEUE_RO_ENTRY(queue_max_write_zeroes_sectors, "write_zeroes_max_bytes");

QUEUE_RO_ENTRY(queue_zone_append_max, "zone_append_max_bytes");

QUEUE_RO_ENTRY(queue_max_zone_append_sectors, "zone_append_max_bytes");

QUEUE_RO_ENTRY(queue_zone_write_granularity, "zone_write_granularity");



QUEUE_RO_ENTRY(queue_zoned, "zoned");
@@ -607,7 +596,7 @@ static struct attribute *queue_attrs[] = { 
	&queue_atomic_write_unit_max_entry.attr,

	&queue_write_same_max_entry.attr,

	&queue_max_write_zeroes_sectors_entry.attr,

	&queue_zone_append_max_entry.attr,

	&queue_max_zone_append_sectors_entry.attr,

	&queue_zone_write_granularity_entry.attr,

	&queue_rotational_entry.attr,

	&queue_zoned_entry.attr,

drivers/block/null_blk/zoned.c

+1 −1
Original line number Diff line number Diff line
@@ -166,7 +166,7 @@ int null_init_zoned_dev(struct nullb_device *dev, 


	lim->features |= BLK_FEAT_ZONED;

	lim->chunk_sectors = dev->zone_size_sects;

	lim->max_zone_append_sectors = dev->zone_append_max_sectors;

	lim->max_hw_zone_append_sectors = dev->zone_append_max_sectors;

	lim->max_open_zones = dev->zone_max_open;

	lim->max_active_zones = dev->zone_max_active;

	return 0;