Commit d2528be7 authored by Keith Busch's avatar Keith Busch Committed by Jens Axboe
Browse files

block: introduce rq_list_move 



When iterating a list, a particular request may need to be moved for
special handling. Provide a helper function to achieve that so drivers
don't need to reimplement rqlist manipulation.

Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220105170518.3181469-4-kbusch@kernel.org


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 3764fd05

include/linux/blk-mq.h

+17 −0
Original line number Diff line number Diff line
@@ -249,6 +249,23 @@ static inline unsigned short req_get_ioprio(struct request *req) 
#define rq_list_next(rq)	(rq)->rq_next

#define rq_list_empty(list)	((list) == (struct request *) NULL)



/**

 * rq_list_move() - move a struct request from one list to another

 * @src: The source list @rq is currently in

 * @dst: The destination list that @rq will be appended to

 * @rq: The request to move

 * @prev: The request preceding @rq in @src (NULL if @rq is the head)

 */

static void inline rq_list_move(struct request **src, struct request **dst,

				struct request *rq, struct request *prev)

{

	if (prev)

		prev->rq_next = rq->rq_next;

	else

		*src = rq->rq_next;

	rq_list_add(dst, rq);

}



enum blk_eh_timer_return {

	BLK_EH_DONE,		/* drivers has completed the command */

	BLK_EH_RESET_TIMER,	/* reset timer and try again */