Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 7acf0277 authored by Mikulas Patocka's avatar Mikulas Patocka Committed by Alasdair G Kergon
Browse files

dm: introduce split_discard_requests 



This patch introduces a new variable split_discard_requests. It can be
set by targets so that discard requests are split on max_io_len
boundaries.

When split_discard_requests is not set, discard requests are only split on
boundaries between targets, as was the case before this patch.

Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent 55f2b8bd

drivers/md/dm.c

+4 −1
Original line number Diff line number Diff line
@@ -1215,7 +1215,10 @@ static int __clone_and_map_discard(struct clone_info *ci) 
		if (!ti->num_discard_requests)

			return -EOPNOTSUPP;



		if (!ti->split_discard_requests)

			len = min(ci->sector_count, max_io_len_target_boundary(ci->sector, ti));

		else

			len = min(ci->sector_count, max_io_len(ci->sector, ti));



		__issue_target_requests(ci, ti, ti->num_discard_requests, len);

include/linux/device-mapper.h

+6 −0
Original line number Diff line number Diff line
@@ -217,6 +217,12 @@ struct dm_target { 
	 */

	unsigned discards_supported:1;



	/*

	 * Set if the target required discard request to be split

	 * on max_io_len boundary.

	 */

	unsigned split_discard_requests:1;



	/*

	 * Set if this target does not return zeroes on discarded blocks.

	 */