Commit 65803c20 authored by Mike Snitzer's avatar Mike Snitzer
Browse files

dm table: train hybrid target type detection to select blk-mq if appropriate 



Otherwise replacing the multipath target with the error target fails:
  device-mapper: ioctl: can't change device type after initial table load.

The error target was mistakenly considered to be target type
DM_TYPE_REQUEST_BASED rather than DM_TYPE_MQ_REQUEST_BASED even if the
target it was to replace was of type DM_TYPE_MQ_REQUEST_BASED.

Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent e5863d9a

drivers/md/dm-table.c

+20 −15
Original line number Diff line number Diff line
@@ -831,7 +831,7 @@ static int dm_table_set_type(struct dm_table *t) 
	struct dm_target *tgt;

	struct dm_dev_internal *dd;

	struct list_head *devices;

	unsigned live_md_type;

	unsigned live_md_type = dm_get_md_type(t->md);



	for (i = 0; i < t->num_targets; i++) {

		tgt = t->targets + i;
@@ -855,8 +855,8 @@ static int dm_table_set_type(struct dm_table *t) 
		 * Determine the type from the live device.

		 * Default to bio-based if device is new.

		 */

		live_md_type = dm_get_md_type(t->md);

		if (live_md_type == DM_TYPE_REQUEST_BASED)

		if (live_md_type == DM_TYPE_REQUEST_BASED ||

		    live_md_type == DM_TYPE_MQ_REQUEST_BASED)

			request_based = 1;

		else

			bio_based = 1;
@@ -870,6 +870,17 @@ static int dm_table_set_type(struct dm_table *t) 


	BUG_ON(!request_based); /* No targets in this table */



	/*

	 * Request-based dm supports only tables that have a single target now.

	 * To support multiple targets, request splitting support is needed,

	 * and that needs lots of changes in the block-layer.

	 * (e.g. request completion process for partial completion.)

	 */

	if (t->num_targets > 1) {

		DMWARN("Request-based dm doesn't support multiple targets yet");

		return -EINVAL;

	}



	/* Non-request-stackable devices can't be used for request-based dm */

	devices = dm_table_get_devices(t);

	list_for_each_entry(dd, devices, list) {
@@ -893,20 +904,14 @@ static int dm_table_set_type(struct dm_table *t) 
				      " are blk-mq request-stackable");

				return -EINVAL;

			}

	}

		t->type = DM_TYPE_MQ_REQUEST_BASED;



	/*

	 * Request-based dm supports only tables that have a single target now.

	 * To support multiple targets, request splitting support is needed,

	 * and that needs lots of changes in the block-layer.

	 * (e.g. request completion process for partial completion.)

	 */

	if (t->num_targets > 1) {

		DMWARN("Request-based dm doesn't support multiple targets yet");

		return -EINVAL;

	}

	} else if (hybrid && list_empty(devices) && live_md_type != DM_TYPE_NONE) {

		/* inherit live MD type */

		t->type = live_md_type;



	t->type = !use_blk_mq ? DM_TYPE_REQUEST_BASED : DM_TYPE_MQ_REQUEST_BASED;

	} else

		t->type = DM_TYPE_REQUEST_BASED;



	return 0;

}

drivers/md/dm.h

+2 −1
Original line number Diff line number Diff line
@@ -101,7 +101,8 @@ int dm_setup_md_queue(struct mapped_device *md); 
/*

 * To check whether the target type is request-based or not (bio-based).

 */

#define dm_target_request_based(t) ((t)->type->map_rq != NULL)

#define dm_target_request_based(t) (((t)->type->map_rq != NULL) || \

				    ((t)->type->clone_and_map_rq != NULL))



/*

 * To check whether the target type is a hybrid (capable of being

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