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| author | Mikulas Patocka <mpatocka@redhat.com> | 2012-07-27 16:08:03 +0200 |
|---|---|---|
| committer | Alasdair G Kergon <agk@redhat.com> | 2012-07-27 16:08:03 +0200 |
| commit | 7acf0277cea0f2da89ffffcc9892bea23f618e63 (patch) | |
| tree | 5f5c77f9ab0750826691d53a027cdcd786771fbb | |
| parent | dm thin: support for non power of 2 pool blocksize (diff) | |
| download | linux-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>
| -rw-r--r-- | drivers/md/dm.c | 5 | ||||
| -rw-r--r-- | include/linux/device-mapper.h | 6 |
2 files changed, 10 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); diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index b19c1e189a68..8bdbbfce759a 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -218,6 +218,12 @@ 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. */ unsigned discard_zeroes_data_unsupported:1; |