blk-mq: add helper to insert requests from irq context
Both the cache flush state machine and the SCSI midlayer want to submit
requests from irq context, and the current per-request requeue_work
unfortunately causes corruption due to sharing with the csd field for
flushes. Replace them with a per-request_queue list of requests to
be requeued.
Based on an earlier test by Ming Lei.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Ming Lei <tom.leiming@gmail.com>
Tested-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/blk-flush.c b/block/blk-flush.c
index ec7a224..ef608b3 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -130,21 +130,13 @@
blk_clear_rq_complete(rq);
}
-static void mq_flush_run(struct work_struct *work)
-{
- struct request *rq;
-
- rq = container_of(work, struct request, requeue_work);
-
- memset(&rq->csd, 0, sizeof(rq->csd));
- blk_mq_insert_request(rq, false, true, false);
-}
-
static bool blk_flush_queue_rq(struct request *rq, bool add_front)
{
if (rq->q->mq_ops) {
- INIT_WORK(&rq->requeue_work, mq_flush_run);
- kblockd_schedule_work(&rq->requeue_work);
+ struct request_queue *q = rq->q;
+
+ blk_mq_add_to_requeue_list(rq, add_front);
+ blk_mq_kick_requeue_list(q);
return false;
} else {
if (add_front)