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| author | Sasha Levin <sasha.levin@oracle.com> | 2015-04-09 20:13:50 -0400 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2015-04-16 20:11:47 -0400 |
| commit | 58533aeccead3c0a2a1d989f5e1df5f2d8c09702 (patch) | |
| tree | 381939b65bf089af06bde020258bad28241088ba | |
| parent | 0f4687c37c09794b8f1d701edb1372149cedd2eb (diff) | |
| download | lwn-58533aeccead3c0a2a1d989f5e1df5f2d8c09702.tar.gz lwn-58533aeccead3c0a2a1d989f5e1df5f2d8c09702.zip | |
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.c | 11 |
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 |