block: add a sanity check for non-write flush/fua bios

Check that the PREFUSH and FUA flags are only set on write bios, given that the flush state machine expects that. [Damien] The check is also extended to REQ_OP_ZONE_APPEND operations as these are data write operations used by btrfs and zonefs and may also have the REQ_FUA bit set. Reported-by: Damien Le Moal <[email protected]> Signed-off-by: Christoph Hellwig <[email protected]> Signed-off-by: Damien Le Moal <[email protected]> Reviewed-by: Jens Axboe <[email protected]> Reviewed-by: Niklas Cassel <[email protected]> Reviewed-by: Hannes Reinecke <[email protected]>
pop-os · Jan 13, 2023 · b4a6bb3 · b4a6bb3
1 parent 002c487
commit b4a6bb3
Showing 1 changed file with 9 additions and 5 deletions.
diff --git a/block/blk-core.c b/block/blk-core.c
@@ -744,12 +744,16 @@ void submit_bio_noacct(struct bio *bio)
 	 * Filter flush bio's early so that bio based drivers without flush
 	 * support don't have to worry about them.
 	 */
-	if (op_is_flush(bio->bi_opf) &&
-	    !test_bit(QUEUE_FLAG_WC, &q->queue_flags)) {
-		bio->bi_opf &= ~(REQ_PREFLUSH | REQ_FUA);
-		if (!bio_sectors(bio)) {
-			status = BLK_STS_OK;
+	if (op_is_flush(bio->bi_opf)) {
+		if (WARN_ON_ONCE(bio_op(bio) != REQ_OP_WRITE &&
+				 bio_op(bio) != REQ_OP_ZONE_APPEND))
 			goto end_io;
+		if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags)) {
+			bio->bi_opf &= ~(REQ_PREFLUSH | REQ_FUA);
+			if (!bio_sectors(bio)) {
+				status = BLK_STS_OK;
+				goto end_io;
+			}
 		}
 	}