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authorSasha Levin <sasha.levin@oracle.com>2015-04-09 20:13:50 -0400
committerSasha Levin <sasha.levin@oracle.com>2015-04-16 20:11:47 -0400
commit58533aeccead3c0a2a1d989f5e1df5f2d8c09702 (patch)
tree381939b65bf089af06bde020258bad28241088ba
parent0f4687c37c09794b8f1d701edb1372149cedd2eb (diff)
dm thin: fix to consistently zero-fill reads to unprovisioned blocks
[ Upstream commit 5f027a3bf184d1d36e68745f7cd3718a8b879cc0 ] It was always intended that a read to an unprovisioned block will return zeroes regardless of whether the pool is in read-only or read-write mode. thin_bio_map() was inconsistent with its handling of such reads when the pool is in read-only mode, it now properly zero-fills the bios it returns in response to unprovisioned block reads. Eliminate thin_bio_map()'s special read-only mode handling of -ENODATA and just allow the IO to be deferred to the worker which will result in pool->process_bio() handling the IO (which already properly zero-fills reads to unprovisioned blocks). Reported-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
-rw-r--r--drivers/md/dm-thin.c11
1 files changed, 0 insertions, 11 deletions
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index ac6b0ff161ea..0801e35b9940 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -2003,17 +2003,6 @@ static int thin_bio_map(struct dm_target *ti, struct bio *bio)
return DM_MAPIO_REMAPPED;
case -ENODATA:
- if (get_pool_mode(tc->pool) == PM_READ_ONLY) {
- /*
- * This block isn't provisioned, and we have no way
- * of doing so.
- */
- handle_unserviceable_bio(tc->pool, bio);
- cell_defer_no_holder_no_free(tc, &cell1);
- return DM_MAPIO_SUBMITTED;
- }
- /* fall through */
-
case -EWOULDBLOCK:
/*
* In future, the failed dm_thin_find_block above could