blk-mq: introduce blk_mq_complete_request_sync()
In NVMe's error handler, follows the typical steps of tearing down hardware for recovering controller: 1) stop blk_mq hw queues 2) stop the real hw queues 3) cancel in-flight requests via blk_mq_tagset_busy_iter(tags, cancel_request, ...) cancel_request(): mark the request as abort blk_mq_complete_request(req); 4) destroy real hw queues However, there may be race between #3 and #4, because blk_mq_complete_request() may run q->mq_ops->complete(rq) remotelly and asynchronously, and ->complete(rq) may be run after #4. This patch introduces blk_mq_complete_request_sync() for fixing the above race. Cc: Sagi Grimberg <sagi@grimberg.me> Cc: Bart Van Assche <bvanassche@acm.org> Cc: James Smart <james.smart@broadcom.com> Cc: linux-nvme@lists.infradead.org Reviewed-by:Keith Busch <keith.busch@intel.com> Reviewed-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
Ming Lei <ming.lei@redhat.com> Signed-off-by:
Jens Axboe <axboe@kernel.dk>
parent
1978f30a
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