Commit 95363efd authored by Jens Axboe's avatar Jens Axboe
Browse files

blk-mq: allow blk_mq_init_commands() to return failure 



If drivers do dynamic allocation in the hardware command init
path, then we need to be able to handle and return failures.

And if they do allocations or mappings in the init command path,
then we need a cleanup function to free up that space at exit
time. So add blk_mq_free_commands() as the cleanup function.

This is required for the mtip32xx driver conversion to blk-mq.

Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 89f8b33c

block/blk-mq.c

+45 −7
Original line number Diff line number Diff line
@@ -1058,33 +1058,71 @@ static void blk_mq_hctx_notify(void *data, unsigned long action, 
	blk_mq_put_ctx(ctx);

}



static void blk_mq_init_hw_commands(struct blk_mq_hw_ctx *hctx,

				    void (*init)(void *, struct blk_mq_hw_ctx *,

static int blk_mq_init_hw_commands(struct blk_mq_hw_ctx *hctx,

				   int (*init)(void *, struct blk_mq_hw_ctx *,

					struct request *, unsigned int),

				   void *data)

{

	unsigned int i;

	int ret = 0;



	for (i = 0; i < hctx->queue_depth; i++) {

		struct request *rq = hctx->rqs[i];



		init(data, hctx, rq, i);

		ret = init(data, hctx, rq, i);

		if (ret)

			break;

	}



	return ret;

}



void blk_mq_init_commands(struct request_queue *q,

			  void (*init)(void *, struct blk_mq_hw_ctx *,

int blk_mq_init_commands(struct request_queue *q,

			 int (*init)(void *, struct blk_mq_hw_ctx *,

					struct request *, unsigned int),

			 void *data)

{

	struct blk_mq_hw_ctx *hctx;

	unsigned int i;

	int ret = 0;



	queue_for_each_hw_ctx(q, hctx, i)

		blk_mq_init_hw_commands(hctx, init, data);

	queue_for_each_hw_ctx(q, hctx, i) {

		ret = blk_mq_init_hw_commands(hctx, init, data);

		if (ret)

			break;

	}



	return ret;

}

EXPORT_SYMBOL(blk_mq_init_commands);



static void blk_mq_free_hw_commands(struct blk_mq_hw_ctx *hctx,

				    void (*free)(void *, struct blk_mq_hw_ctx *,

					struct request *, unsigned int),

				    void *data)

{

	unsigned int i;



	for (i = 0; i < hctx->queue_depth; i++) {

		struct request *rq = hctx->rqs[i];



		free(data, hctx, rq, i);

	}

}



void blk_mq_free_commands(struct request_queue *q,

			  void (*free)(void *, struct blk_mq_hw_ctx *,

					struct request *, unsigned int),

			  void *data)

{

	struct blk_mq_hw_ctx *hctx;

	unsigned int i;



	queue_for_each_hw_ctx(q, hctx, i)

		blk_mq_free_hw_commands(hctx, free, data);

}

EXPORT_SYMBOL(blk_mq_free_commands);



static void blk_mq_free_rq_map(struct blk_mq_hw_ctx *hctx)

{

	struct page *page;

drivers/block/virtio_blk.c

+2 −1
Original line number Diff line number Diff line
@@ -490,13 +490,14 @@ static struct blk_mq_reg virtio_mq_reg = { 
	.flags		= BLK_MQ_F_SHOULD_MERGE,

};



static void virtblk_init_vbr(void *data, struct blk_mq_hw_ctx *hctx,

static int virtblk_init_vbr(void *data, struct blk_mq_hw_ctx *hctx,

			     struct request *rq, unsigned int nr)

{

	struct virtio_blk *vblk = data;

	struct virtblk_req *vbr = rq->special;



	sg_init_table(vbr->sg, vblk->sg_elems);

	return 0;

}



static int virtblk_probe(struct virtio_device *vdev)

include/linux/blk-mq.h

+2 −1
Original line number Diff line number Diff line
@@ -117,7 +117,8 @@ enum { 
struct request_queue *blk_mq_init_queue(struct blk_mq_reg *, void *);

int blk_mq_register_disk(struct gendisk *);

void blk_mq_unregister_disk(struct gendisk *);

void blk_mq_init_commands(struct request_queue *, void (*init)(void *data, struct blk_mq_hw_ctx *, struct request *, unsigned int), void *data);

int blk_mq_init_commands(struct request_queue *, int (*init)(void *data, struct blk_mq_hw_ctx *, struct request *, unsigned int), void *data);

void blk_mq_free_commands(struct request_queue *, void (*free)(void *data, struct blk_mq_hw_ctx *, struct request *, unsigned int), void *data);



void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);

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