From e8c5d45f82ce0c238a4817739892fe8897a3dcc3 Mon Sep 17 00:00:00 2001
From: Yeongjin Gil <youngjin.gil@samsung.com>
Date: Mon, 20 Mar 2023 15:59:32 +0900
Subject: [PATCH] dm verity: fix error handling for check_at_most_once on FEC
Git-commit: e8c5d45f82ce0c238a4817739892fe8897a3dcc3
Patch-mainline: v6.4-rc1
References: git-fixes

In verity_end_io(), if bi_status is not BLK_STS_OK, it can be return
directly. But if FEC configured, it is desired to correct the data page
through verity_verify_io. And the return value will be 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.

(Coly Li: refreshed for Linux 4.12 based SUSE kernel)

Fixes: 843f38d382b1 ("dm verity: add 'check_at_most_once' option to only validate hashes once")
Cc: stable@vger.kernel.org
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Yeongjin Gil <youngjin.gil@samsung.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Coly Li <colyli@suse.de>

---
 drivers/md/dm-verity-target.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/md/dm-verity-target.c
+++ b/drivers/md/dm-verity-target.c
@@ -477,7 +477,7 @@ static int verity_verify_io(struct dm_ve
 		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, &io->iter);
 			continue;