blk-mq: dont assume rq->errors is set when returning an error from ->queue_rq

rq->errors never has been part of the communication protocol between drivers
and the block stack and most drivers will not have initialized it.

Return -EIO to upper layers when the driver returns BLK_MQ_RQ_QUEUE_ERROR
unconditionally.  If a driver want to return a different error it can easily
do so by returning success after calling blk_mq_end_io itself.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index a59b056..0480710 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -605,8 +605,8 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
                        break;
                default:
                        pr_err("blk-mq: bad return on queue: %d\n", ret);
-                       rq->errors = -EIO;
                case BLK_MQ_RQ_QUEUE_ERROR:
+                       rq->errors = -EIO;
                        blk_mq_end_io(rq, rq->errors);
                        break;
                }