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>
This commit is contained in:
Christoph Hellwig
2014-05-28 08:08:02 -06:00
committed by Jens Axboe
parent 7738dac4f6
commit 6fca6a611c
4 changed files with 73 additions and 14 deletions

View File

@@ -172,6 +172,8 @@ void blk_mq_end_io(struct request *rq, int error);
void __blk_mq_end_io(struct request *rq, int error);
void blk_mq_requeue_request(struct request *rq);
void blk_mq_add_to_requeue_list(struct request *rq, bool at_head);
void blk_mq_kick_requeue_list(struct request_queue *q);
void blk_mq_complete_request(struct request *rq);
void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx);