Commit eaa160ed authored by Mike Snitzer's avatar Mike Snitzer
Browse files

dm table: fix NVMe bio-based dm_table_determine_type() validation 



The 'verify_rq_based:' code in dm_table_determine_type() was checking
all devices in the DM table rather than only checking the data devices.
Fix this by using the immutable target's iterate_devices method.

Also, tweak the block of dm_table_determine_type() code that decides
whether to upgrade from DM_TYPE_BIO_BASED to DM_TYPE_NVME_BIO_BASED so
that it makes sure the immutable_target doesn't support require
splitting IOs.

These changes have been verified to allow a "thin-pool" target whose
data device is an NVMe device to be upgraded to DM_TYPE_NVME_BIO_BASED.
Using the thin-pool in NVMe bio-based mode was verified to pass all the
device-mapper-test-suite's "thin-provisioning" tests.

Also verified that request-based DM multipath (with queue_mode "rq" and
"mq") works as expected using the 'mptest' harness.

Fixes: 22c11858 ("dm: introduce DM_TYPE_NVME_BIO_BASED")
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent c12c9a3c

drivers/md/dm-table.c

+35 −22
Original line number Diff line number Diff line
@@ -912,13 +912,31 @@ static bool dm_table_supports_dax(struct dm_table *t) 


static bool dm_table_does_not_support_partial_completion(struct dm_table *t);



struct verify_rq_based_data {

	unsigned sq_count;

	unsigned mq_count;

};



static int device_is_rq_based(struct dm_target *ti, struct dm_dev *dev,

			      sector_t start, sector_t len, void *data)

{

	struct request_queue *q = bdev_get_queue(dev->bdev);

	struct verify_rq_based_data *v = data;



	if (q->mq_ops)

		v->mq_count++;

	else

		v->sq_count++;



	return queue_is_rq_based(q);

}



static int dm_table_determine_type(struct dm_table *t)

{

	unsigned i;

	unsigned bio_based = 0, request_based = 0, hybrid = 0;

	unsigned sq_count = 0, mq_count = 0;

	struct verify_rq_based_data v = {.sq_count = 0, .mq_count = 0};

	struct dm_target *tgt;

	struct dm_dev_internal *dd;

	struct list_head *devices = dm_table_get_devices(t);

	enum dm_queue_mode live_md_type = dm_get_md_type(t->md);
@@ -972,11 +990,15 @@ static int dm_table_determine_type(struct dm_table *t) 
		if (dm_table_supports_dax(t) ||

		    (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) {

			t->type = DM_TYPE_DAX_BIO_BASED;

		} else if ((dm_table_get_immutable_target(t) &&

			    dm_table_does_not_support_partial_completion(t)) ||

			   (list_empty(devices) && live_md_type == DM_TYPE_NVME_BIO_BASED)) {

		} else {

			/* Check if upgrading to NVMe bio-based is valid or required */

			tgt = dm_table_get_immutable_target(t);

			if (tgt && !tgt->max_io_len && dm_table_does_not_support_partial_completion(t)) {

				t->type = DM_TYPE_NVME_BIO_BASED;

			goto verify_rq_based;

				goto verify_rq_based; /* must be stacked directly on NVMe (blk-mq) */

			} else if (list_empty(devices) && live_md_type == DM_TYPE_NVME_BIO_BASED) {

				t->type = DM_TYPE_NVME_BIO_BASED;

			}

		}

		return 0;

	}
@@ -1025,25 +1047,16 @@ verify_rq_based: 
	}



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

	list_for_each_entry(dd, devices, list) {

		struct request_queue *q = bdev_get_queue(dd->dm_dev->bdev);



		if (!queue_is_rq_based(q)) {

			DMERR("table load rejected: including"

			      " non-request-stackable devices");

	if (!tgt->type->iterate_devices ||

	    !tgt->type->iterate_devices(tgt, device_is_rq_based, &v)) {

		DMERR("table load rejected: including non-request-stackable devices");

		return -EINVAL;

	}



		if (q->mq_ops)

			mq_count++;

		else

			sq_count++;

	}

	if (sq_count && mq_count) {

	if (v.sq_count && v.mq_count) {

		DMERR("table load rejected: not all devices are blk-mq request-stackable");

		return -EINVAL;

	}

	t->all_blk_mq = mq_count > 0;

	t->all_blk_mq = v.mq_count > 0;



	if (!t->all_blk_mq &&

	    (t->type == DM_TYPE_MQ_REQUEST_BASED || t->type == DM_TYPE_NVME_BIO_BASED)) {

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