From: Mikulas Patocka <mpatocka@redhat.com>

Date: Sun, 22 Jan 2023 14:03:56 -0500

Subject: [PATCH] dm flakey: fix logic when corrupting a bio

References: bsc#1012628

Patch-mainline: 6.2.3

Git-commit: aa56b9b75996ff4c76a0a4181c2fa0206c3d91cc

commit aa56b9b75996ff4c76a0a4181c2fa0206c3d91cc upstream.

If "corrupt_bio_byte" is set to corrupt reads and corrupt_bio_flags is

used, dm-flakey would erroneously return all writes as errors. Likewise,

if "corrupt_bio_byte" is set to corrupt writes, dm-flakey would return

errors for all reads.

Fix the logic so that if fc->corrupt_bio_byte is non-zero, dm-flakey

will not abort reads on writes with an error.

Cc: stable@vger.kernel.org

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>

Signed-off-by: Mike Snitzer <snitzer@kernel.org>

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Jiri Slaby <jslaby@suse.cz>

---

 drivers/md/dm-flakey.c | 23 +++++++++++++----------

 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/md/dm-flakey.c b/drivers/md/dm-flakey.c

index 89fa7a68..220bbf35 100644

--- a/drivers/md/dm-flakey.c

+++ b/drivers/md/dm-flakey.c

@@ -361,9 +361,11 @@ static int flakey_map(struct dm_target *ti, struct bio *bio)

 		/*

 		 * Corrupt matching writes.

 		 */

-		if (fc->corrupt_bio_byte && (fc->corrupt_bio_rw == WRITE)) {

-			if (all_corrupt_bio_flags_match(bio, fc))

-				corrupt_bio_data(bio, fc);

+		if (fc->corrupt_bio_byte) {

+			if (fc->corrupt_bio_rw == WRITE) {

+				if (all_corrupt_bio_flags_match(bio, fc))

+					corrupt_bio_data(bio, fc);

+			}

 			goto map_bio;

 		}

@@ -389,13 +391,14 @@ static int flakey_end_io(struct dm_target *ti, struct bio *bio,

 		return DM_ENDIO_DONE;

 	if (!*error && pb->bio_submitted && (bio_data_dir(bio) == READ)) {

-		if (fc->corrupt_bio_byte && (fc->corrupt_bio_rw == READ) &&

-		    all_corrupt_bio_flags_match(bio, fc)) {

-			/*

-			 * Corrupt successful matching READs while in down state.

-			 */

-			corrupt_bio_data(bio, fc);

-

+		if (fc->corrupt_bio_byte) {

+			if ((fc->corrupt_bio_rw == READ) &&

+			    all_corrupt_bio_flags_match(bio, fc)) {

+				/*

+				 * Corrupt successful matching READs while in down state.

+				 */

+				corrupt_bio_data(bio, fc);

+			}

 		} else if (!test_bit(DROP_WRITES, &fc->flags) &&

 			   !test_bit(ERROR_WRITES, &fc->flags)) {

 			/*

-- 

2.35.3