dm integrity: do not check integrity for failed read operations

Even though read operations fail, dm_integrity_map_continue() calls
integrity_metadata() to check integrity. In this case, just complete
these.

This also makes it so read I/O errors do not generate integrity warnings
in the kernel log.

Cc: [e-mail]
Signed-off-by: Hyunchul Lee <[e-mail]>
Acked-by: Milan Broz <[e-mail]>
Acked-by: Mikulas Patocka <[e-mail]>
Signed-off-by: Mike Snitzer <[e-mail]>

drivers/md/dm-integrity.c

···
 
 	if (need_sync_io) {
 		wait_for_completion_io(&read_comp);
-		integrity_metadata(&dio->work);
+		if (likely(!bio->bi_status))
+			integrity_metadata(&dio->work);
+		else
+			dec_in_flight(dio);
+
 	} else {
 		INIT_WORK(&dio->work, integrity_metadata);
 		queue_work(ic->metadata_wq, &dio->work);