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authorAlasdair G Kergon <agk@redhat.com>2013-01-31 14:23:36 +0000
committerAlasdair G Kergon <agk@redhat.com>2013-01-31 14:23:36 +0000
commitfe7af2d3babefabd96a39e8b0d58ede88f3c7993 (patch)
tree43f3facbed2274c5cec7df6ef2fc9ecdfa527f4c /drivers/md/dm.c
parent0f640dca08330dfc7820d610578e5935b5e654b2 (diff)
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dm: fix write same requests counting
When processing write same requests, fix dm to send the configured number of WRITE SAME requests to the target rather than the number of discards, which is not always the same. Device-mapper WRITE SAME support was introduced by commit 23508a96cd2e857d57044a2ed7d305f2d9daf441 ("dm: add WRITE SAME support"). Signed-off-by: Alasdair G Kergon <agk@redhat.com> Acked-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm.c')
-rw-r--r--drivers/md/dm.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index c72e4d5a9617..314a0e2faf79 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1188,6 +1188,7 @@ static int __clone_and_map_changing_extent_only(struct clone_info *ci,
{
struct dm_target *ti;
sector_t len;
+ unsigned num_requests;
do {
ti = dm_table_find_target(ci->map, ci->sector);
@@ -1200,7 +1201,8 @@ static int __clone_and_map_changing_extent_only(struct clone_info *ci,
* reconfiguration might also have changed that since the
* check was performed.
*/
- if (!get_num_requests || !get_num_requests(ti))
+ num_requests = get_num_requests ? get_num_requests(ti) : 0;
+ if (!num_requests)
return -EOPNOTSUPP;
if (is_split_required && !is_split_required(ti))
@@ -1208,7 +1210,7 @@ static int __clone_and_map_changing_extent_only(struct clone_info *ci,
else
len = min(ci->sector_count, max_io_len(ci->sector, ti));
- __issue_target_requests(ci, ti, ti->num_discard_requests, len);
+ __issue_target_requests(ci, ti, num_requests, len);
ci->sector += len;
} while (ci->sector_count -= len);