Commit 2e9ee095 authored by Pankaj Gupta's avatar Pankaj Gupta Committed by Dan Williams
Browse files

dm: enable synchronous dax 



This patch sets dax device 'DAXDEV_SYNC' flag if all the target
devices of device mapper support synchrononous DAX. If device
mapper consists of both synchronous and asynchronous dax devices,
we don't set 'DAXDEV_SYNC' flag.

'dm_table_supports_dax' is refactored to pass 'iterate_devices_fn'
as argument so that the callers can pass the appropriate functions.

Suggested-by: default avatarMike Snitzer <snitzer@redhat.com>
Signed-off-by: default avatarPankaj Gupta <pagupta@redhat.com>
Reviewed-by: default avatarMike Snitzer <snitzer@redhat.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent fefc1d97

drivers/md/dm-table.c

+18 −6
Original line number Diff line number Diff line
@@ -881,7 +881,7 @@ void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type) 
EXPORT_SYMBOL_GPL(dm_table_set_type);



/* validate the dax capability of the target device span */

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

int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,

				       sector_t start, sector_t len, void *data)

{

	int blocksize = *(int *) data;
@@ -890,7 +890,15 @@ static int device_supports_dax(struct dm_target *ti, struct dm_dev *dev, 
			start, len);

}



bool dm_table_supports_dax(struct dm_table *t, int blocksize)

/* Check devices support synchronous DAX */

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

				       sector_t start, sector_t len, void *data)

{

	return dax_synchronous(dev->dax_dev);

}



bool dm_table_supports_dax(struct dm_table *t,

			  iterate_devices_callout_fn iterate_fn, int *blocksize)

{

	struct dm_target *ti;

	unsigned i;
@@ -903,8 +911,7 @@ bool dm_table_supports_dax(struct dm_table *t, int blocksize) 
			return false;



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

		    !ti->type->iterate_devices(ti, device_supports_dax,

			    &blocksize))

			!ti->type->iterate_devices(ti, iterate_fn, blocksize))

			return false;

	}
@@ -940,6 +947,7 @@ static int dm_table_determine_type(struct dm_table *t) 
	struct dm_target *tgt;

	struct list_head *devices = dm_table_get_devices(t);

	enum dm_queue_mode live_md_type = dm_get_md_type(t->md);

	int page_size = PAGE_SIZE;



	if (t->type != DM_TYPE_NONE) {

		/* target already set the table's type */
@@ -984,7 +992,7 @@ static int dm_table_determine_type(struct dm_table *t) 
verify_bio_based:

		/* We must use this table as bio-based */

		t->type = DM_TYPE_BIO_BASED;

		if (dm_table_supports_dax(t, PAGE_SIZE) ||

		if (dm_table_supports_dax(t, device_supports_dax, &page_size) ||

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

			t->type = DM_TYPE_DAX_BIO_BASED;

		} else {
@@ -1883,6 +1891,7 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, 
			       struct queue_limits *limits)

{

	bool wc = false, fua = false;

	int page_size = PAGE_SIZE;



	/*

	 * Copy table's limits to the DM device's request_queue
@@ -1910,8 +1919,11 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, 
	}

	blk_queue_write_cache(q, wc, fua);



	if (dm_table_supports_dax(t, PAGE_SIZE))

	if (dm_table_supports_dax(t, device_supports_dax, &page_size)) {

		blk_queue_flag_set(QUEUE_FLAG_DAX, q);

		if (dm_table_supports_dax(t, device_synchronous, NULL))

			set_dax_synchronous(t->md->dax_dev);

	}

	else

		blk_queue_flag_clear(QUEUE_FLAG_DAX, q);

drivers/md/dm.c

+1 −1
Original line number Diff line number Diff line
@@ -1119,7 +1119,7 @@ static bool dm_dax_supported(struct dax_device *dax_dev, struct block_device *bd 
	if (!map)

		return false;



	ret = dm_table_supports_dax(map, blocksize);

	ret = dm_table_supports_dax(map, device_supports_dax, &blocksize);



	dm_put_live_table(md, srcu_idx);

drivers/md/dm.h

+4 −1
Original line number Diff line number Diff line
@@ -72,7 +72,10 @@ bool dm_table_bio_based(struct dm_table *t); 
bool dm_table_request_based(struct dm_table *t);

void dm_table_free_md_mempools(struct dm_table *t);

struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);

bool dm_table_supports_dax(struct dm_table *t, int blocksize);

bool dm_table_supports_dax(struct dm_table *t, iterate_devices_callout_fn fn,

			   int *blocksize);

int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,

			   sector_t start, sector_t len, void *data);



void dm_lock_md_type(struct mapped_device *md);

void dm_unlock_md_type(struct mapped_device *md);

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