Commit 32ac5a9b authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

blk-mq: avoid a mess of casts for blk_end_sync_rq 



Instead of trying to cast a __bitwise 32-bit integer to a larger integer
and then a pointer, just allow a struct with the blk_status_t and the
completion on stack and set the end_io_data to that.  Use the
opportunity to move the code to where it belongs and drop rather
confusing comments.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarKeith Busch <kbusch@kernel.org>
Reviewed-by: default avatarChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220524121530.943123-3-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent ae948fd6

block/blk-mq.c

+20 −23
Original line number Diff line number Diff line
@@ -1151,24 +1151,6 @@ void blk_mq_start_request(struct request *rq) 
}

EXPORT_SYMBOL(blk_mq_start_request);



/**

 * blk_end_sync_rq - executes a completion event on a request

 * @rq: request to complete

 * @error: end I/O status of the request

 */

static void blk_end_sync_rq(struct request *rq, blk_status_t error)

{

	struct completion *waiting = rq->end_io_data;



	rq->end_io_data = (void *)(uintptr_t)error;



	/*

	 * complete last, if this is a stack request the process (and thus

	 * the rq pointer) could be invalid right after this complete()

	 */

	complete(waiting);

}



/*

 * Allow 2x BLK_MAX_REQUEST_COUNT requests on plug queue for multiple

 * queues. This is important for md arrays to benefit from merging
@@ -1231,6 +1213,19 @@ void blk_execute_rq_nowait(struct request *rq, bool at_head, rq_end_io_fn *done) 
}

EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);



struct blk_rq_wait {

	struct completion done;

	blk_status_t ret;

};



static void blk_end_sync_rq(struct request *rq, blk_status_t ret)

{

	struct blk_rq_wait *wait = rq->end_io_data;



	wait->ret = ret;

	complete(&wait->done);

}



static bool blk_rq_is_poll(struct request *rq)

{

	if (!rq->mq_hctx)
@@ -1262,7 +1257,9 @@ static void blk_rq_poll_completion(struct request *rq, struct completion *wait) 
 */

blk_status_t blk_execute_rq(struct request *rq, bool at_head)

{

	DECLARE_COMPLETION_ONSTACK(wait);

	struct blk_rq_wait wait = {

		.done = COMPLETION_INITIALIZER_ONSTACK(wait.done),

	};



	WARN_ON(irqs_disabled());

	WARN_ON(!blk_rq_is_passthrough(rq));
@@ -1274,7 +1271,7 @@ blk_status_t blk_execute_rq(struct request *rq, bool at_head) 
	blk_mq_sched_insert_request(rq, at_head, true, false);



	if (blk_rq_is_poll(rq)) {

		blk_rq_poll_completion(rq, &wait);

		blk_rq_poll_completion(rq, &wait.done);

	} else {

		/*

		 * Prevent hang_check timer from firing at us during very long
@@ -1283,14 +1280,14 @@ blk_status_t blk_execute_rq(struct request *rq, bool at_head) 
		unsigned long hang_check = sysctl_hung_task_timeout_secs;



		if (hang_check)

			while (!wait_for_completion_io_timeout(&wait,

			while (!wait_for_completion_io_timeout(&wait.done,

					hang_check * (HZ/2)))

				;

		else

			wait_for_completion_io(&wait);

			wait_for_completion_io(&wait.done);

	}



	return (blk_status_t)(uintptr_t)rq->end_io_data;

	return wait.ret;

}

EXPORT_SYMBOL(blk_execute_rq);