Commit cf0fbf89 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: add a bdev_max_discard_sectors helper 



Add a helper to query the number of sectors support per each discard bio
based on the block device and use this helper to stop various places from
poking into the request_queue to see if discard is supported and if so how
much.  This mirrors what is done e.g. for write zeroes as well.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Acked-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> [drbd]
Acked-by: Coly Li <colyli@suse.de> [bcache]
Acked-by: David Sterba <dsterba@suse.com> [btrfs]
Reviewed-by: default avatarChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220415045258.199825-24-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent e3cc28ea

drivers/block/drbd/drbd_nl.c

+5 −3
Original line number Diff line number Diff line
@@ -1439,7 +1439,8 @@ static bool write_ordering_changed(struct disk_conf *a, struct disk_conf *b) 
static void sanitize_disk_conf(struct drbd_device *device, struct disk_conf *disk_conf,

			       struct drbd_backing_dev *nbc)

{

	struct request_queue * const q = nbc->backing_bdev->bd_disk->queue;

	struct block_device *bdev = nbc->backing_bdev;

	struct request_queue *q = bdev->bd_disk->queue;



	if (disk_conf->al_extents < DRBD_AL_EXTENTS_MIN)

		disk_conf->al_extents = DRBD_AL_EXTENTS_MIN;
@@ -1455,6 +1456,7 @@ static void sanitize_disk_conf(struct drbd_device *device, struct disk_conf *dis 


	if (disk_conf->rs_discard_granularity) {

		int orig_value = disk_conf->rs_discard_granularity;

		sector_t discard_size = bdev_max_discard_sectors(bdev) << 9;

		int remainder;



		if (q->limits.discard_granularity > disk_conf->rs_discard_granularity)
@@ -1463,8 +1465,8 @@ static void sanitize_disk_conf(struct drbd_device *device, struct disk_conf *dis 
		remainder = disk_conf->rs_discard_granularity % q->limits.discard_granularity;

		disk_conf->rs_discard_granularity += remainder;



		if (disk_conf->rs_discard_granularity > q->limits.max_discard_sectors << 9)

			disk_conf->rs_discard_granularity = q->limits.max_discard_sectors << 9;

		if (disk_conf->rs_discard_granularity > discard_size)

			disk_conf->rs_discard_granularity = discard_size;



		if (disk_conf->rs_discard_granularity != orig_value)

			drbd_info(device, "rs_discard_granularity changed to %d\n",

drivers/block/drbd/drbd_receiver.c

+1 −1
Original line number Diff line number Diff line
@@ -1524,7 +1524,7 @@ int drbd_issue_discard_or_zero_out(struct drbd_device *device, sector_t start, u 
	granularity = max(q->limits.discard_granularity >> 9, 1U);

	alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;



	max_discard_sectors = min(q->limits.max_discard_sectors, (1U << 22));

	max_discard_sectors = min(bdev_max_discard_sectors(bdev), (1U << 22));

	max_discard_sectors -= max_discard_sectors % granularity;

	if (unlikely(!max_discard_sectors))

		goto zero_out;

drivers/block/rnbd/rnbd-srv-dev.h

+1 −2
Original line number Diff line number Diff line
@@ -52,8 +52,7 @@ static inline int rnbd_dev_get_max_discard_sects(const struct rnbd_dev *dev) 
	if (!blk_queue_discard(bdev_get_queue(dev->bdev)))

		return 0;



	return blk_queue_get_max_sectors(bdev_get_queue(dev->bdev),

					 REQ_OP_DISCARD);

	return bdev_max_discard_sectors(dev->bdev);

}



static inline int rnbd_dev_get_discard_granularity(const struct rnbd_dev *dev)

drivers/md/dm-io.c

+1 −1
Original line number Diff line number Diff line
@@ -311,7 +311,7 @@ static void do_region(int op, int op_flags, unsigned region, 
	 * Reject unsupported discard and write same requests.

	 */

	if (op == REQ_OP_DISCARD)

		special_cmd_max_sectors = q->limits.max_discard_sectors;

		special_cmd_max_sectors = bdev_max_discard_sectors(where->bdev);

	else if (op == REQ_OP_WRITE_ZEROES)

		special_cmd_max_sectors = q->limits.max_write_zeroes_sectors;

	if ((op == REQ_OP_DISCARD || op == REQ_OP_WRITE_ZEROES) &&

drivers/target/target_core_device.c

+3 −4
Original line number Diff line number Diff line
@@ -829,9 +829,8 @@ struct se_device *target_alloc_device(struct se_hba *hba, const char *name) 
}



/*

 * Check if the underlying struct block_device request_queue supports

 * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM

 * in ATA and we need to set TPE=1

 * Check if the underlying struct block_device supports discard and if yes

 * configure the UNMAP parameters.

 */

bool target_configure_unmap_from_queue(struct se_dev_attrib *attrib,

				       struct block_device *bdev)
@@ -843,7 +842,7 @@ bool target_configure_unmap_from_queue(struct se_dev_attrib *attrib, 
		return false;



	attrib->max_unmap_lba_count =

		q->limits.max_discard_sectors >> (ilog2(block_size) - 9);

		bdev_max_discard_sectors(bdev) >> (ilog2(block_size) - 9);

	/*

	 * Currently hardcoded to 1 in Linux/SCSI code..

	 */