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authorMikulas Patocka <mpatocka@redhat.com>2012-07-27 16:08:03 +0200
committerAlasdair G Kergon <agk@redhat.com>2012-07-27 16:08:03 +0200
commit7acf0277cea0f2da89ffffcc9892bea23f618e63 (patch)
tree5f5c77f9ab0750826691d53a027cdcd786771fbb /drivers/md
parentdm thin: support for non power of 2 pool blocksize (diff)
downloadlinux-7acf0277cea0f2da89ffffcc9892bea23f618e63.tar.xz
linux-7acf0277cea0f2da89ffffcc9892bea23f618e63.zip
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>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/dm.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 415c2803c0c9..4e09b6ff5b49 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1215,7 +1215,10 @@ static int __clone_and_map_discard(struct clone_info *ci)
if (!ti->num_discard_requests)
return -EOPNOTSUPP;
- len = min(ci->sector_count, max_io_len_target_boundary(ci->sector, ti));
+ 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);