dm: remove support for stacking dm-mq on .request_fn device(s) (c5248f79) · Commits · 戴 / test

drivers/md/dm-mpath.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -418,7 +418,10 @@ static int __multipath_map(struct dm_target ti, struct request clone,
		spin_unlock_irq(&m->lock);

		if (clone) {
		/* Old request-based interface: allocated clone is passed in */
		/*
		* Old request-based interface: allocated clone is passed in.
		* Used by: .request_fn stacked on .request_fn path(s).
		*/
		clone->q = bdev_get_queue(bdev);
		clone->rq_disk = bdev->bd_disk;
		clone->cmd_flags \|= REQ_FAILFAST_TRANSPORT;

drivers/md/dm.c

+16 −39

Original line number	Diff line number	Diff line
		@@ -1141,11 +1141,6 @@ static void free_rq_clone(struct request *clone)
		else if (!md->queue->mq_ops)
		/* request_fn queue stacked on request_fn queue(s) */
		free_clone_request(md, clone);
		/*
		* NOTE: for the blk-mq queue stacked on request_fn queue(s) case:
		* no need to call free_clone_request() because we leverage blk-mq by
		* allocating the clone at the end of the blk-mq pdu (see: clone_rq)
		*/

		if (!md->queue->mq_ops)
		free_rq_tio(tio);
		@@ -1866,23 +1861,17 @@ static struct request clone_rq(struct request rq, struct mapped_device *md,
		struct dm_rq_target_io *tio, gfp_t gfp_mask)
		{
		/*
		* Do not allocate a clone if tio->clone was already set
		* (see: dm_mq_queue_rq).
		* Create clone for use with .request_fn request_queue
		*/
		bool alloc_clone = !tio->clone;
		struct request *clone;

		if (alloc_clone) {
		clone = alloc_clone_request(md, gfp_mask);
		if (!clone)
		return NULL;
		} else
		clone = tio->clone;

		blk_rq_init(NULL, clone);
		if (setup_clone(clone, rq, tio, gfp_mask)) {
		/* -ENOMEM */
		if (alloc_clone)
		free_clone_request(md, clone);
		return NULL;
		}
		@@ -2692,15 +2681,6 @@ static int dm_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
		*/
		tio->ti = ti;

		/*
		* Both the table and md type cannot change after initial table load
		*/
		if (dm_get_md_type(md) == DM_TYPE_REQUEST_BASED) {
		/* clone request is allocated at the end of the pdu */
		tio->clone = (void *)blk_mq_rq_to_pdu(rq) + sizeof(struct dm_rq_target_io);
		(void) clone_rq(rq, md, tio, GFP_ATOMIC);
		queue_kthread_work(&md->kworker, &tio->work);
		} else {
		/* Direct call is fine since .queue_rq allows allocations */
		if (map_request(tio, rq, md) == DM_MAPIO_REQUEUE) {
		/* Undo dm_start_request() before requeuing */
		@@ -2708,7 +2688,6 @@ static int dm_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
		rq_completed(md, rq_data_dir(rq), false);
		return BLK_MQ_RQ_QUEUE_BUSY;
		}
		}

		return BLK_MQ_RQ_QUEUE_OK;
		}
		@@ -2726,6 +2705,11 @@ static int dm_init_request_based_blk_mq_queue(struct mapped_device *md)
		struct request_queue *q;
		int err;

		if (dm_get_md_type(md) == DM_TYPE_REQUEST_BASED) {
		DMERR("request-based dm-mq may only be stacked on blk-mq device(s)");
		return -EINVAL;
		}

		md->tag_set = kzalloc(sizeof(struct blk_mq_tag_set), GFP_KERNEL);
		if (!md->tag_set)
		return -ENOMEM;
		@@ -2738,10 +2722,6 @@ static int dm_init_request_based_blk_mq_queue(struct mapped_device *md)
		md->tag_set->driver_data = md;

		md->tag_set->cmd_size = sizeof(struct dm_rq_target_io);
		if (md_type == DM_TYPE_REQUEST_BASED) {
		/* put the memory for non-blk-mq clone at the end of the pdu */
		md->tag_set->cmd_size += sizeof(struct request);
		}

		err = blk_mq_alloc_tag_set(md->tag_set);
		if (err)
		@@ -2758,9 +2738,6 @@ static int dm_init_request_based_blk_mq_queue(struct mapped_device *md)
		/* backfill 'mq' sysfs registration normally done in blk_register_queue */
		blk_mq_register_disk(md->disk);

		if (md_type == DM_TYPE_REQUEST_BASED)
		init_rq_based_worker_thread(md);

		return 0;

		out_tag_set:

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