Commit 591ddcfc authored by Mike Snitzer's avatar Mike Snitzer
Browse files

dm: allow immutable request-based targets to use blk-mq pdu 



This will allow DM multipath to use a portion of the blk-mq pdu space
for target data (e.g. struct dm_mpath_io).

Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 30187e1d

drivers/md/dm-ioctl.c

+1 −1
Original line number Diff line number Diff line
@@ -1304,7 +1304,7 @@ static int table_load(struct dm_ioctl *param, size_t param_size) 
		dm_set_md_type(md, dm_table_get_type(t));



		/* setup md->queue to reflect md's type (may block) */

		r = dm_setup_md_queue(md);

		r = dm_setup_md_queue(md, t);

		if (r) {

			DMWARN("unable to set up device queue for new table.");

			goto err_unlock_md_type;

drivers/md/dm.c

+26 −7
Original line number Diff line number Diff line
@@ -224,7 +224,8 @@ struct mapped_device { 


	/* for blk-mq request-based DM support */

	struct blk_mq_tag_set *tag_set;

	bool use_blk_mq;

	bool use_blk_mq:1;

	bool init_tio_pdu:1;

};



#ifdef CONFIG_DM_MQ_DEFAULT
@@ -243,6 +244,7 @@ bool dm_use_blk_mq(struct mapped_device *md) 
{

	return md->use_blk_mq;

}

EXPORT_SYMBOL_GPL(dm_use_blk_mq);



/*

 * For mempools pre-allocation at the table loading time.
@@ -1889,6 +1891,12 @@ static void init_tio(struct dm_rq_target_io *tio, struct request *rq, 
	tio->clone = NULL;

	tio->orig = rq;

	tio->error = 0;

	/*

	 * Avoid initializing info for blk-mq; it passes

	 * target-specific data through info.ptr

	 * (see: dm_mq_init_request)

	 */

	if (!md->init_tio_pdu)

		memset(&tio->info, 0, sizeof(tio->info));

	if (md->kworker_task)

		init_kthread_work(&tio->work, map_tio_request);
@@ -2313,6 +2321,7 @@ static struct mapped_device *alloc_dev(int minor) 
		goto bad_io_barrier;



	md->use_blk_mq = use_blk_mq;

	md->init_tio_pdu = false;

	md->type = DM_TYPE_NONE;

	mutex_init(&md->suspend_lock);

	mutex_init(&md->type_lock);
@@ -2653,6 +2662,11 @@ static int dm_mq_init_request(void *data, struct request *rq, 
	 */

	tio->md = md;



	if (md->init_tio_pdu) {

		/* target-specific per-io data is immediately after the tio */

		tio->info.ptr = tio + 1;

	}



	return 0;

}
@@ -2704,7 +2718,8 @@ static struct blk_mq_ops dm_mq_ops = { 
	.init_request = dm_mq_init_request,

};



static int dm_mq_init_request_queue(struct mapped_device *md)

static int dm_mq_init_request_queue(struct mapped_device *md,

				    struct dm_target *immutable_tgt)

{

	struct request_queue *q;

	int err;
@@ -2726,6 +2741,11 @@ static int dm_mq_init_request_queue(struct mapped_device *md) 
	md->tag_set->driver_data = md;



	md->tag_set->cmd_size = sizeof(struct dm_rq_target_io);

	if (immutable_tgt && immutable_tgt->per_io_data_size) {

		/* any target-specific per-io data is immediately after the tio */

		md->tag_set->cmd_size += immutable_tgt->per_io_data_size;

		md->init_tio_pdu = true;

	}



	err = blk_mq_alloc_tag_set(md->tag_set);

	if (err)
@@ -2763,7 +2783,7 @@ static unsigned filter_md_type(unsigned type, struct mapped_device *md) 
/*

 * Setup the DM device's queue based on md's type

 */

int dm_setup_md_queue(struct mapped_device *md)

int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t)

{

	int r;

	unsigned md_type = filter_md_type(dm_get_md_type(md), md);
@@ -2777,7 +2797,7 @@ int dm_setup_md_queue(struct mapped_device *md) 
		}

		break;

	case DM_TYPE_MQ_REQUEST_BASED:

		r = dm_mq_init_request_queue(md);

		r = dm_mq_init_request_queue(md, dm_table_get_immutable_target(t));

		if (r) {

			DMERR("Cannot initialize queue for request-based dm-mq mapped device");

			return r;
@@ -3505,8 +3525,7 @@ struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, unsigned t 
		if (!pool_size)

			pool_size = dm_get_reserved_rq_based_ios();

		front_pad = offsetof(struct dm_rq_clone_bio_info, clone);

		/* per_io_data_size is not used. */

		WARN_ON(per_io_data_size != 0);

		/* per_io_data_size is used for blk-mq pdu at queue allocation */

		break;

	default:

		BUG();

drivers/md/dm.h

+1 −1
Original line number Diff line number Diff line
@@ -86,7 +86,7 @@ void dm_set_md_type(struct mapped_device *md, unsigned type); 
unsigned dm_get_md_type(struct mapped_device *md);

struct target_type *dm_get_immutable_target_type(struct mapped_device *md);



int dm_setup_md_queue(struct mapped_device *md);

int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t);



/*

 * To check the return value from dm_table_find_target().