[PATCH] dm verity: fix error handling for check_at_most_once

[Yeongjin Gil]

In verity_work(), the return value of verity_verify_io() is converted to
blk_status and passed to verity_finish_io(). BTW, when a bit is set in
v->validated_blocks, verity_verify_io() skips verification regardless of
I/O error for the corresponding bio. In this case, the I/O error could
not be returned properly, and as a result, there is a problem that
abnormal data could be read for the corresponding block.

To fix this problem, when an I/O error occurs, do not skip verification
even if the bit related is set in v->validated_blocks.

Fixes: 843f38d382b1 ("dm verity: add 'check_at_most_once' option to only validate hashes once")

Signed-off-by: Sungjong Seo <sj1557.seo@xxxxxxxxxxx>
Signed-off-by: Yeongjin Gil <youngjin.gil@xxxxxxxxxxx>
---
 drivers/md/dm-verity-target.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c
index ade83ef3b439..9316399b920e 100644
--- a/drivers/md/dm-verity-target.c
+++ b/drivers/md/dm-verity-target.c
@@ -523,7 +523,7 @@ static int verity_verify_io(struct dm_verity_io *io)
 		sector_t cur_block = io->block + b;
 		struct ahash_request *req = verity_io_hash_req(v, io);
 
-		if (v->validated_blocks &&
+		if (v->validated_blocks && bio->bi_status == BLK_STS_OK &&
 		    likely(test_bit(cur_block, v->validated_blocks))) {
 			verity_bv_skip_block(v, io, iter);
 			continue;
-- 
2.39.2