Merge tag 'dm-3.5-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm

Pull device-mapper discard fixes from Alasdair G Kergon:
  - avoid a crash in dm-raid1 when discards coincide with mirror
    recovery;
  - avoid discarding shared data that's still needed in dm-thin;
  - don't guarantee that discarded blocks will be wiped in dm-raid1.

* tag 'dm-3.5-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
  dm raid1: set discard_zeroes_data_unsupported
  dm thin: do not send discards to shared blocks
  dm raid1: fix crash with mirror recovery and discard

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index ce59824fb414..68694da0d21d 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -1245,7 +1245,10 @@ static void process_discard(struct thin_c *tc, struct bio *bio)
 
                         cell_release_singleton(cell, bio);
                         cell_release_singleton(cell2, bio);
-                        remap_and_issue(tc, bio, lookup_result.block);
+                        if ((!lookup_result.shared) && pool->pf.discard_passdown)
+                                remap_and_issue(tc, bio, lookup_result.block);
+                        else
+                                bio_endio(bio, 0);
                 }
                 break;
 
@@ -2628,6 +2631,7 @@ static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv)
         if (tc->pool->pf.discard_enabled) {
                 ti->discards_supported = 1;
                 ti->num_discard_requests = 1;
+                ti->discard_zeroes_data_unsupported = 1;
         }
 
         dm_put(pool_md);