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: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This commit is contained in:
Mikulas Patocka
2012-07-27 15:08:03 +01:00
committed by Alasdair G Kergon
parent 55f2b8bdb0
commit 7acf0277ce
2 changed files with 10 additions and 1 deletions

View File

@@ -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.
*/