Commit c1e2b842 authored Aug 10, 2020 by Ming Lei Committed by Jens Axboe Aug 11, 2020

block: fix double account of flush request's driver tag



In case of none scheduler, we share data request's driver tag for
flush request, so have to mark the flush request as INFLIGHT for
avoiding double account of this driver tag.

Fixes: 568f2700 ("blk-mq: centralise related handling into blk_mq_get_driver_tag")
Reported-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Matthew Wilcox <willy@infradead.org>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent fe6a8fc5

block/blk-flush.c

+9 −2

Original line number	Diff line number	Diff line
		@@ -308,9 +308,16 @@ static void blk_kick_flush(struct request_queue q, struct blk_flush_queue fq,
		flush_rq->mq_ctx = first_rq->mq_ctx;
		flush_rq->mq_hctx = first_rq->mq_hctx;

		if (!q->elevator)
		if (!q->elevator) {
		flush_rq->tag = first_rq->tag;
		else

		/*
		* We borrow data request's driver tag, so have to mark
		* this flush request as INFLIGHT for avoiding double
		* account of this driver tag
		*/
		flush_rq->rq_flags \|= RQF_MQ_INFLIGHT;
		} else
		flush_rq->internal_tag = first_rq->internal_tag;

		flush_rq->cmd_flags = REQ_OP_FLUSH \| REQ_PREFLUSH;

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