Merge tag 'libnvdimm-for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull dax and libnvdimm updates from Dan Williams:
 "The bulk of this is a rework of the dax_operations API after
  discovering the obstacles it posed to the work-in-progress DAX+reflink
  support for XFS and other copy-on-write filesystem mechanics.

  Primarily the need to plumb a block_device through the API to handle
  partition offsets was a sticking point and Christoph untangled that
  dependency in addition to other cleanups to make landing the
  DAX+reflink support easier.

  The DAX_PMEM_COMPAT option has been around for 4 years and not only
  are distributions shipping userspace that understand the current
  configuration API, but some are not even bothering to turn this option
  on anymore, so it seems a good time to remove it per the deprecation
  schedule. Recall that this was added after the device-dax subsystem
  moved from /sys/class/dax to /sys/bus/dax for its sysfs organization.
  All recent functionality depends on /sys/bus/dax.

  Some other miscellaneous cleanups and reflink prep patches are
  included as well.

  Summary:

   - Simplify the dax_operations API:

      - Eliminate bdev_dax_pgoff() in favor of the filesystem
        maintaining and applying a partition offset to all its DAX iomap
        operations.

      - Remove wrappers and device-mapper stacked callbacks for
        ->copy_from_iter() and ->copy_to_iter() in favor of moving
        block_device relative offset responsibility to the
        dax_direct_access() caller.

      - Remove the need for an @bdev in filesystem-DAX infrastructure

      - Remove unused uio helpers copy_from_iter_flushcache() and
        copy_mc_to_iter() as only the non-check_copy_size() versions are
        used for DAX.

   - Prepare XFS for the pending (next merge window) DAX+reflink support

   - Remove deprecated DEV_DAX_PMEM_COMPAT support

   - Cleanup a straggling misuse of the GUID api"

* tag 'libnvdimm-for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (38 commits)
  iomap: Fix error handling in iomap_zero_iter()
  ACPI: NFIT: Import GUID before use
  dax: remove the copy_from_iter and copy_to_iter methods
  dax: remove the DAXDEV_F_SYNC flag
  dax: simplify dax_synchronous and set_dax_synchronous
  uio: remove copy_from_iter_flushcache() and copy_mc_to_iter()
  iomap: turn the byte variable in iomap_zero_iter into a ssize_t
  memremap: remove support for external pgmap refcounts
  fsdax: don't require CONFIG_BLOCK
  iomap: build the block based code conditionally
  dax: fix up some of the block device related ifdefs
  fsdax: shift partition offset handling into the file systems
  dax: return the partition offset from fs_dax_get_by_bdev
  iomap: add a IOMAP_DAX flag
  xfs: pass the mapping flags to xfs_bmbt_to_iomap
  xfs: use xfs_direct_write_iomap_ops for DAX zeroing
  xfs: move dax device handling into xfs_{alloc,free}_buftarg
  ext4: cleanup the dax handling in ext4_fill_super
  ext2: cleanup the dax handling in ext2_fill_super
  fsdax: decouple zeroing from the iomap buffered I/O code
  ...

7 files changed, 58 insertions, 307 deletions

diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index 66ba16713f69..1b97a11d7151 100644
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c
@@ -162,71 +162,34 @@ static int linear_iterate_devices(struct dm_target *ti,
 	return fn(ti, lc->dev, lc->start, ti->len, data);
 }
 
-#if IS_ENABLED(CONFIG_DAX_DRIVER)
-static long linear_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
-		long nr_pages, void **kaddr, pfn_t *pfn)
+#if IS_ENABLED(CONFIG_FS_DAX)
+static struct dax_device *linear_dax_pgoff(struct dm_target *ti, pgoff_t *pgoff)
 {
-	long ret;
 	struct linear_c *lc = ti->private;
-	struct block_device *bdev = lc->dev->bdev;
-	struct dax_device *dax_dev = lc->dev->dax_dev;
-	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
-
-	dev_sector = linear_map_sector(ti, sector);
-	ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages * PAGE_SIZE, &pgoff);
-	if (ret)
-		return ret;
-	return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn);
-}
+	sector_t sector = linear_map_sector(ti, *pgoff << PAGE_SECTORS_SHIFT);
 
-static size_t linear_dax_copy_from_iter(struct dm_target *ti, pgoff_t pgoff,
-		void *addr, size_t bytes, struct iov_iter *i)
-{
-	struct linear_c *lc = ti->private;
-	struct block_device *bdev = lc->dev->bdev;
-	struct dax_device *dax_dev = lc->dev->dax_dev;
-	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
-
-	dev_sector = linear_map_sector(ti, sector);
-	if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
-		return 0;
-	return dax_copy_from_iter(dax_dev, pgoff, addr, bytes, i);
+	*pgoff = (get_start_sect(lc->dev->bdev) + sector) >> PAGE_SECTORS_SHIFT;
+	return lc->dev->dax_dev;
 }
 
-static size_t linear_dax_copy_to_iter(struct dm_target *ti, pgoff_t pgoff,
-		void *addr, size_t bytes, struct iov_iter *i)
+static long linear_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
+		long nr_pages, void **kaddr, pfn_t *pfn)
 {
-	struct linear_c *lc = ti->private;
-	struct block_device *bdev = lc->dev->bdev;
-	struct dax_device *dax_dev = lc->dev->dax_dev;
-	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
-
-	dev_sector = linear_map_sector(ti, sector);
-	if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
-		return 0;
-	return dax_copy_to_iter(dax_dev, pgoff, addr, bytes, i);
+	struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff);
+
+	return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn);
 }
 
 static int linear_dax_zero_page_range(struct dm_target *ti, pgoff_t pgoff,
 				      size_t nr_pages)
 {
-	int ret;
-	struct linear_c *lc = ti->private;
-	struct block_device *bdev = lc->dev->bdev;
-	struct dax_device *dax_dev = lc->dev->dax_dev;
-	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
-
-	dev_sector = linear_map_sector(ti, sector);
-	ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages << PAGE_SHIFT, &pgoff);
-	if (ret)
-		return ret;
+	struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff);
+
 	return dax_zero_page_range(dax_dev, pgoff, nr_pages);
 }
 
 #else
 #define linear_dax_direct_access NULL
-#define linear_dax_copy_from_iter NULL
-#define linear_dax_copy_to_iter NULL
 #define linear_dax_zero_page_range NULL
 #endif
 
@@ -244,8 +207,6 @@ static struct target_type linear_target = {
 	.prepare_ioctl = linear_prepare_ioctl,
 	.iterate_devices = linear_iterate_devices,
 	.direct_access = linear_dax_direct_access,
-	.dax_copy_from_iter = linear_dax_copy_from_iter,
-	.dax_copy_to_iter = linear_dax_copy_to_iter,
 	.dax_zero_page_range = linear_dax_zero_page_range,
 };
 
diff --git a/drivers/md/dm-log-writes.c b/drivers/md/dm-log-writes.c
index 0b3ef977ceeb..139b09b06eda 100644
--- a/drivers/md/dm-log-writes.c
+++ b/drivers/md/dm-log-writes.c
@@ -901,120 +901,34 @@ static void log_writes_io_hints(struct dm_target *ti, struct queue_limits *limit
 	limits->io_min = limits->physical_block_size;
 }
 
-#if IS_ENABLED(CONFIG_DAX_DRIVER)
-static int log_dax(struct log_writes_c *lc, sector_t sector, size_t bytes,
-		   struct iov_iter *i)
+#if IS_ENABLED(CONFIG_FS_DAX)
+static struct dax_device *log_writes_dax_pgoff(struct dm_target *ti,
+		pgoff_t *pgoff)
 {
-	struct pending_block *block;
-
-	if (!bytes)
-		return 0;
-
-	block = kzalloc(sizeof(struct pending_block), GFP_KERNEL);
-	if (!block) {
-		DMERR("Error allocating dax pending block");
-		return -ENOMEM;
-	}
-
-	block->data = kzalloc(bytes, GFP_KERNEL);
-	if (!block->data) {
-		DMERR("Error allocating dax data space");
-		kfree(block);
-		return -ENOMEM;
-	}
-
-	/* write data provided via the iterator */
-	if (!copy_from_iter(block->data, bytes, i)) {
-		DMERR("Error copying dax data");
-		kfree(block->data);
-		kfree(block);
-		return -EIO;
-	}
-
-	/* rewind the iterator so that the block driver can use it */
-	iov_iter_revert(i, bytes);
-
-	block->datalen = bytes;
-	block->sector = bio_to_dev_sectors(lc, sector);
-	block->nr_sectors = ALIGN(bytes, lc->sectorsize) >> lc->sectorshift;
-
-	atomic_inc(&lc->pending_blocks);
-	spin_lock_irq(&lc->blocks_lock);
-	list_add_tail(&block->list, &lc->unflushed_blocks);
-	spin_unlock_irq(&lc->blocks_lock);
-	wake_up_process(lc->log_kthread);
+	struct log_writes_c *lc = ti->private;
 
-	return 0;
+	*pgoff += (get_start_sect(lc->dev->bdev) >> PAGE_SECTORS_SHIFT);
+	return lc->dev->dax_dev;
 }
 
 static long log_writes_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
 					 long nr_pages, void **kaddr, pfn_t *pfn)
 {
-	struct log_writes_c *lc = ti->private;
-	sector_t sector = pgoff * PAGE_SECTORS;
-	int ret;
-
-	ret = bdev_dax_pgoff(lc->dev->bdev, sector, nr_pages * PAGE_SIZE, &pgoff);
-	if (ret)
-		return ret;
-	return dax_direct_access(lc->dev->dax_dev, pgoff, nr_pages, kaddr, pfn);
-}
-
-static size_t log_writes_dax_copy_from_iter(struct dm_target *ti,
-					    pgoff_t pgoff, void *addr, size_t bytes,
-					    struct iov_iter *i)
-{
-	struct log_writes_c *lc = ti->private;
-	sector_t sector = pgoff * PAGE_SECTORS;
-	int err;
-
-	if (bdev_dax_pgoff(lc->dev->bdev, sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
-		return 0;
-
-	/* Don't bother doing anything if logging has been disabled */
-	if (!lc->logging_enabled)
-		goto dax_copy;
-
-	err = log_dax(lc, sector, bytes, i);
-	if (err) {
-		DMWARN("Error %d logging DAX write", err);
-		return 0;
-	}
-dax_copy:
-	return dax_copy_from_iter(lc->dev->dax_dev, pgoff, addr, bytes, i);
-}
-
-static size_t log_writes_dax_copy_to_iter(struct dm_target *ti,
-					  pgoff_t pgoff, void *addr, size_t bytes,
-					  struct iov_iter *i)
-{
-	struct log_writes_c *lc = ti->private;
-	sector_t sector = pgoff * PAGE_SECTORS;
+	struct dax_device *dax_dev = log_writes_dax_pgoff(ti, &pgoff);
 
-	if (bdev_dax_pgoff(lc->dev->bdev, sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
-		return 0;
-	return dax_copy_to_iter(lc->dev->dax_dev, pgoff, addr, bytes, i);
+	return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn);
 }
 
 static int log_writes_dax_zero_page_range(struct dm_target *ti, pgoff_t pgoff,
 					  size_t nr_pages)
 {
-	int ret;
-	struct log_writes_c *lc = ti->private;
-	sector_t sector = pgoff * PAGE_SECTORS;
-
-	ret = bdev_dax_pgoff(lc->dev->bdev, sector, nr_pages << PAGE_SHIFT,
-			     &pgoff);
-	if (ret)
-		return ret;
-	return dax_zero_page_range(lc->dev->dax_dev, pgoff,
-				   nr_pages << PAGE_SHIFT);
+	struct dax_device *dax_dev = log_writes_dax_pgoff(ti, &pgoff);
+
+	return dax_zero_page_range(dax_dev, pgoff, nr_pages << PAGE_SHIFT);
 }
 
 #else
 #define log_writes_dax_direct_access NULL
-#define log_writes_dax_copy_from_iter NULL
-#define log_writes_dax_copy_to_iter NULL
 #define log_writes_dax_zero_page_range NULL
 #endif
 
@@ -1032,8 +946,6 @@ static struct target_type log_writes_target = {
 	.iterate_devices = log_writes_iterate_devices,
 	.io_hints = log_writes_io_hints,
 	.direct_access = log_writes_dax_direct_access,
-	.dax_copy_from_iter = log_writes_dax_copy_from_iter,
-	.dax_copy_to_iter = log_writes_dax_copy_to_iter,
 	.dax_zero_page_range = log_writes_dax_zero_page_range,
 };
 
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index 6660b6b53d5b..e566115ec0bb 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -300,91 +300,40 @@ static int stripe_map(struct dm_target *ti, struct bio *bio)
 	return DM_MAPIO_REMAPPED;
 }
 
-#if IS_ENABLED(CONFIG_DAX_DRIVER)
-static long stripe_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
-		long nr_pages, void **kaddr, pfn_t *pfn)
+#if IS_ENABLED(CONFIG_FS_DAX)
+static struct dax_device *stripe_dax_pgoff(struct dm_target *ti, pgoff_t *pgoff)
 {
-	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
 	struct stripe_c *sc = ti->private;
-	struct dax_device *dax_dev;
 	struct block_device *bdev;
+	sector_t dev_sector;
 	uint32_t stripe;
-	long ret;
 
-	stripe_map_sector(sc, sector, &stripe, &dev_sector);
+	stripe_map_sector(sc, *pgoff * PAGE_SECTORS, &stripe, &dev_sector);
 	dev_sector += sc->stripe[stripe].physical_start;
-	dax_dev = sc->stripe[stripe].dev->dax_dev;
 	bdev = sc->stripe[stripe].dev->bdev;
 
-	ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages * PAGE_SIZE, &pgoff);
-	if (ret)
-		return ret;
-	return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn);
+	*pgoff = (get_start_sect(bdev) + dev_sector) >> PAGE_SECTORS_SHIFT;
+	return sc->stripe[stripe].dev->dax_dev;
 }
 
-static size_t stripe_dax_copy_from_iter(struct dm_target *ti, pgoff_t pgoff,
-		void *addr, size_t bytes, struct iov_iter *i)
+static long stripe_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
+		long nr_pages, void **kaddr, pfn_t *pfn)
 {
-	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
-	struct stripe_c *sc = ti->private;
-	struct dax_device *dax_dev;
-	struct block_device *bdev;
-	uint32_t stripe;
-
-	stripe_map_sector(sc, sector, &stripe, &dev_sector);
-	dev_sector += sc->stripe[stripe].physical_start;
-	dax_dev = sc->stripe[stripe].dev->dax_dev;
-	bdev = sc->stripe[stripe].dev->bdev;
+	struct dax_device *dax_dev = stripe_dax_pgoff(ti, &pgoff);
 
-	if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
-		return 0;
-	return dax_copy_from_iter(dax_dev, pgoff, addr, bytes, i);
-}
-
-static size_t stripe_dax_copy_to_iter(struct dm_target *ti, pgoff_t pgoff,
-		void *addr, size_t bytes, struct iov_iter *i)
-{
-	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
-	struct stripe_c *sc = ti->private;
-	struct dax_device *dax_dev;
-	struct block_device *bdev;
-	uint32_t stripe;
-
-	stripe_map_sector(sc, sector, &stripe, &dev_sector);
-	dev_sector += sc->stripe[stripe].physical_start;
-	dax_dev = sc->stripe[stripe].dev->dax_dev;
-	bdev = sc->stripe[stripe].dev->bdev;
-
-	if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
-		return 0;
-	return dax_copy_to_iter(dax_dev, pgoff, addr, bytes, i);
+	return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn);
 }
 
 static int stripe_dax_zero_page_range(struct dm_target *ti, pgoff_t pgoff,
 				      size_t nr_pages)
 {
-	int ret;
-	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
-	struct stripe_c *sc = ti->private;
-	struct dax_device *dax_dev;
-	struct block_device *bdev;
-	uint32_t stripe;
-
-	stripe_map_sector(sc, sector, &stripe, &dev_sector);
-	dev_sector += sc->stripe[stripe].physical_start;
-	dax_dev = sc->stripe[stripe].dev->dax_dev;
-	bdev = sc->stripe[stripe].dev->bdev;
+	struct dax_device *dax_dev = stripe_dax_pgoff(ti, &pgoff);
 
-	ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages << PAGE_SHIFT, &pgoff);
-	if (ret)
-		return ret;
 	return dax_zero_page_range(dax_dev, pgoff, nr_pages);
 }
 
 #else
 #define stripe_dax_direct_access NULL
-#define stripe_dax_copy_from_iter NULL
-#define stripe_dax_copy_to_iter NULL
 #define stripe_dax_zero_page_range NULL
 #endif
 
@@ -521,8 +470,6 @@ static struct target_type stripe_target = {
 	.iterate_devices = stripe_iterate_devices,
 	.io_hints = stripe_io_hints,
 	.direct_access = stripe_dax_direct_access,
-	.dax_copy_from_iter = stripe_dax_copy_from_iter,
-	.dax_copy_to_iter = stripe_dax_copy_to_iter,
 	.dax_zero_page_range = stripe_dax_zero_page_range,
 };
 
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index aa173f5bdc3d..e43096cfe9e2 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -806,12 +806,14 @@ 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 */
-int device_not_dax_capable(struct dm_target *ti, struct dm_dev *dev,
+static int device_not_dax_capable(struct dm_target *ti, struct dm_dev *dev,
 			sector_t start, sector_t len, void *data)
 {
-	int blocksize = *(int *) data;
+	if (dev->dax_dev)
+		return false;
 
-	return !dax_supported(dev->dax_dev, dev->bdev, blocksize, start, len);
+	DMDEBUG("%pg: error: dax unsupported by block device", dev->bdev);
+	return true;
 }
 
 /* Check devices support synchronous DAX */
@@ -821,8 +823,8 @@ static int device_not_dax_synchronous_capable(struct dm_target *ti, struct dm_de
 	return !dev->dax_dev || !dax_synchronous(dev->dax_dev);
 }
 
-bool dm_table_supports_dax(struct dm_table *t,
-			   iterate_devices_callout_fn iterate_fn, int *blocksize)
+static bool dm_table_supports_dax(struct dm_table *t,
+			   iterate_devices_callout_fn iterate_fn)
 {
 	struct dm_target *ti;
 	unsigned i;
@@ -835,7 +837,7 @@ bool dm_table_supports_dax(struct dm_table *t,
 			return false;
 
 		if (!ti->type->iterate_devices ||
-		    ti->type->iterate_devices(ti, iterate_fn, blocksize))
+		    ti->type->iterate_devices(ti, iterate_fn, NULL))
 			return false;
 	}
 
@@ -862,7 +864,6 @@ 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 */
@@ -906,7 +907,7 @@ 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, device_not_dax_capable, &page_size) ||
+		if (dm_table_supports_dax(t, device_not_dax_capable) ||
 		    (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) {
 			t->type = DM_TYPE_DAX_BIO_BASED;
 		}
@@ -1976,7 +1977,6 @@ int 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;
 	int r;
 
 	/*
@@ -2010,9 +2010,9 @@ int 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, device_not_dax_capable, &page_size)) {
+	if (dm_table_supports_dax(t, device_not_dax_capable)) {
 		blk_queue_flag_set(QUEUE_FLAG_DAX, q);
-		if (dm_table_supports_dax(t, device_not_dax_synchronous_capable, NULL))
+		if (dm_table_supports_dax(t, device_not_dax_synchronous_capable))
 			set_dax_synchronous(t->md->dax_dev);
 	}
 	else
diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c
index 4b8991cde223..4f31591d2d25 100644
--- a/drivers/md/dm-writecache.c
+++ b/drivers/md/dm-writecache.c
@@ -38,7 +38,7 @@
 #define BITMAP_GRANULARITY	PAGE_SIZE
 #endif
 
-#if IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API) && IS_ENABLED(CONFIG_DAX_DRIVER)
+#if IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API) && IS_ENABLED(CONFIG_FS_DAX)
 #define DM_WRITECACHE_HAS_PMEM
 #endif
 
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 280918cdcabd..c0ae8087c602 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -637,7 +637,7 @@ static int open_table_device(struct table_device *td, dev_t dev,
 			     struct mapped_device *md)
 {
 	struct block_device *bdev;
-
+	u64 part_off;
 	int r;
 
 	BUG_ON(td->dm_dev.bdev);
@@ -653,7 +653,7 @@ static int open_table_device(struct table_device *td, dev_t dev,
 	}
 
 	td->dm_dev.bdev = bdev;
-	td->dm_dev.dax_dev = fs_dax_get_by_bdev(bdev);
+	td->dm_dev.dax_dev = fs_dax_get_by_bdev(bdev, &part_off);
 	return 0;
 }
 
@@ -1027,74 +1027,6 @@ static long dm_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff,
 	return ret;
 }
 
-static bool dm_dax_supported(struct dax_device *dax_dev, struct block_device *bdev,
-		int blocksize, sector_t start, sector_t len)
-{
-	struct mapped_device *md = dax_get_private(dax_dev);
-	struct dm_table *map;
-	bool ret = false;
-	int srcu_idx;
-
-	map = dm_get_live_table(md, &srcu_idx);
-	if (!map)
-		goto out;
-
-	ret = dm_table_supports_dax(map, device_not_dax_capable, &blocksize);
-
-out:
-	dm_put_live_table(md, srcu_idx);
-
-	return ret;
-}
-
-static size_t dm_dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
-				    void *addr, size_t bytes, struct iov_iter *i)
-{
-	struct mapped_device *md = dax_get_private(dax_dev);
-	sector_t sector = pgoff * PAGE_SECTORS;
-	struct dm_target *ti;
-	long ret = 0;
-	int srcu_idx;
-
-	ti = dm_dax_get_live_target(md, sector, &srcu_idx);
-
-	if (!ti)
-		goto out;
-	if (!ti->type->dax_copy_from_iter) {
-		ret = copy_from_iter(addr, bytes, i);
-		goto out;
-	}
-	ret = ti->type->dax_copy_from_iter(ti, pgoff, addr, bytes, i);
- out:
-	dm_put_live_table(md, srcu_idx);
-
-	return ret;
-}
-
-static size_t dm_dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff,
-		void *addr, size_t bytes, struct iov_iter *i)
-{
-	struct mapped_device *md = dax_get_private(dax_dev);
-	sector_t sector = pgoff * PAGE_SECTORS;
-	struct dm_target *ti;
-	long ret = 0;
-	int srcu_idx;
-
-	ti = dm_dax_get_live_target(md, sector, &srcu_idx);
-
-	if (!ti)
-		goto out;
-	if (!ti->type->dax_copy_to_iter) {
-		ret = copy_to_iter(addr, bytes, i);
-		goto out;
-	}
-	ret = ti->type->dax_copy_to_iter(ti, pgoff, addr, bytes, i);
- out:
-	dm_put_live_table(md, srcu_idx);
-
-	return ret;
-}
-
 static int dm_dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff,
 				  size_t nr_pages)
 {
@@ -1683,6 +1615,7 @@ static void cleanup_mapped_device(struct mapped_device *md)
 	bioset_exit(&md->io_bs);
 
 	if (md->dax_dev) {
+		dax_remove_host(md->disk);
 		kill_dax(md->dax_dev);
 		put_dax(md->dax_dev);
 		md->dax_dev = NULL;
@@ -1784,10 +1717,15 @@ static struct mapped_device *alloc_dev(int minor)
 	md->disk->private_data = md;
 	sprintf(md->disk->disk_name, "dm-%d", minor);
 
-	if (IS_ENABLED(CONFIG_DAX_DRIVER)) {
-		md->dax_dev = alloc_dax(md, md->disk->disk_name,
-					&dm_dax_ops, 0);
-		if (IS_ERR(md->dax_dev))
+	if (IS_ENABLED(CONFIG_FS_DAX)) {
+		md->dax_dev = alloc_dax(md, &dm_dax_ops);
+		if (IS_ERR(md->dax_dev)) {
+			md->dax_dev = NULL;
+			goto bad;
+		}
+		set_dax_nocache(md->dax_dev);
+		set_dax_nomc(md->dax_dev);
+		if (dax_add_host(md->dax_dev, md->disk))
 			goto bad;
 	}
 
@@ -3041,9 +2979,6 @@ static const struct block_device_operations dm_rq_blk_dops = {
 
 static const struct dax_operations dm_dax_ops = {
 	.direct_access = dm_dax_direct_access,
-	.dax_supported = dm_dax_supported,
-	.copy_from_iter = dm_dax_copy_from_iter,
-	.copy_to_iter = dm_dax_copy_to_iter,
 	.zero_page_range = dm_dax_zero_page_range,
 };
 
diff --git a/drivers/md/dm.h b/drivers/md/dm.h
index 742d9c80efe1..9013dc1a7b00 100644
--- a/drivers/md/dm.h
+++ b/drivers/md/dm.h
@@ -73,10 +73,6 @@ 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, iterate_devices_callout_fn fn,
-			   int *blocksize);
-int device_not_dax_capable(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);