Three fixes for device-mapper discard processing:

- 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.
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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
This commit is contained in:
Linus Torvalds 2012-07-20 11:51:22 -07:00
commit 935173744a
3 changed files with 11 additions and 3 deletions

View File

@ -1084,6 +1084,7 @@ static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv)
ti->split_io = dm_rh_get_region_size(ms->rh);
ti->num_flush_requests = 1;
ti->num_discard_requests = 1;
ti->discard_zeroes_data_unsupported = 1;
ms->kmirrord_wq = alloc_workqueue("kmirrord",
WQ_NON_REENTRANT | WQ_MEM_RECLAIM, 0);
@ -1214,7 +1215,7 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio,
* We need to dec pending if this was a write.
*/
if (rw == WRITE) {
if (!(bio->bi_rw & REQ_FLUSH))
if (!(bio->bi_rw & (REQ_FLUSH | REQ_DISCARD)))
dm_rh_dec(ms->rh, map_context->ll);
return error;
}

View File

@ -404,6 +404,9 @@ void dm_rh_mark_nosync(struct dm_region_hash *rh, struct bio *bio)
return;
}
if (bio->bi_rw & REQ_DISCARD)
return;
/* We must inform the log that the sync count has changed. */
log->type->set_region_sync(log, region, 0);
@ -524,7 +527,7 @@ void dm_rh_inc_pending(struct dm_region_hash *rh, struct bio_list *bios)
struct bio *bio;
for (bio = bios->head; bio; bio = bio->bi_next) {
if (bio->bi_rw & REQ_FLUSH)
if (bio->bi_rw & (REQ_FLUSH | REQ_DISCARD))
continue;
rh_inc(rh, dm_rh_bio_to_region(rh, bio));
}

View File

@ -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);