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
  ...

1 files changed, 34 insertions, 46 deletions

diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index c7ac486ca5d3..e8f37bdc8354 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -331,13 +331,34 @@ xfs_set_inode_alloc(
 	return xfs_is_inode32(mp) ? maxagi : agcount;
 }
 
-static bool
-xfs_buftarg_is_dax(
-	struct super_block	*sb,
-	struct xfs_buftarg	*bt)
+static int
+xfs_setup_dax_always(
+	struct xfs_mount	*mp)
 {
-	return dax_supported(bt->bt_daxdev, bt->bt_bdev, sb->s_blocksize, 0,
-			bdev_nr_sectors(bt->bt_bdev));
+	if (!mp->m_ddev_targp->bt_daxdev &&
+	    (!mp->m_rtdev_targp || !mp->m_rtdev_targp->bt_daxdev)) {
+		xfs_alert(mp,
+			"DAX unsupported by block device. Turning off DAX.");
+		goto disable_dax;
+	}
+
+	if (mp->m_super->s_blocksize != PAGE_SIZE) {
+		xfs_alert(mp,
+			"DAX not supported for blocksize. Turning off DAX.");
+		goto disable_dax;
+	}
+
+	if (xfs_has_reflink(mp)) {
+		xfs_alert(mp, "DAX and reflink cannot be used together!");
+		return -EINVAL;
+	}
+
+	xfs_warn(mp, "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
+	return 0;
+
+disable_dax:
+	xfs_mount_set_dax_mode(mp, XFS_DAX_NEVER);
+	return 0;
 }
 
 STATIC int
@@ -370,26 +391,19 @@ STATIC void
 xfs_close_devices(
 	struct xfs_mount	*mp)
 {
-	struct dax_device *dax_ddev = mp->m_ddev_targp->bt_daxdev;
-
 	if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp) {
 		struct block_device *logdev = mp->m_logdev_targp->bt_bdev;
-		struct dax_device *dax_logdev = mp->m_logdev_targp->bt_daxdev;
 
 		xfs_free_buftarg(mp->m_logdev_targp);
 		xfs_blkdev_put(logdev);
-		fs_put_dax(dax_logdev);
 	}
 	if (mp->m_rtdev_targp) {
 		struct block_device *rtdev = mp->m_rtdev_targp->bt_bdev;
-		struct dax_device *dax_rtdev = mp->m_rtdev_targp->bt_daxdev;
 
 		xfs_free_buftarg(mp->m_rtdev_targp);
 		xfs_blkdev_put(rtdev);
-		fs_put_dax(dax_rtdev);
 	}
 	xfs_free_buftarg(mp->m_ddev_targp);
-	fs_put_dax(dax_ddev);
 }
 
 /*
@@ -407,8 +421,6 @@ xfs_open_devices(
 	struct xfs_mount	*mp)
 {
 	struct block_device	*ddev = mp->m_super->s_bdev;
-	struct dax_device	*dax_ddev = fs_dax_get_by_bdev(ddev);
-	struct dax_device	*dax_logdev = NULL, *dax_rtdev = NULL;
 	struct block_device	*logdev = NULL, *rtdev = NULL;
 	int			error;
 
@@ -418,8 +430,7 @@ xfs_open_devices(
 	if (mp->m_logname) {
 		error = xfs_blkdev_get(mp, mp->m_logname, &logdev);
 		if (error)
-			goto out;
-		dax_logdev = fs_dax_get_by_bdev(logdev);
+			return error;
 	}
 
 	if (mp->m_rtname) {
@@ -433,25 +444,24 @@ xfs_open_devices(
 			error = -EINVAL;
 			goto out_close_rtdev;
 		}
-		dax_rtdev = fs_dax_get_by_bdev(rtdev);
 	}
 
 	/*
 	 * Setup xfs_mount buffer target pointers
 	 */
 	error = -ENOMEM;
-	mp->m_ddev_targp = xfs_alloc_buftarg(mp, ddev, dax_ddev);
+	mp->m_ddev_targp = xfs_alloc_buftarg(mp, ddev);
 	if (!mp->m_ddev_targp)
 		goto out_close_rtdev;
 
 	if (rtdev) {
-		mp->m_rtdev_targp = xfs_alloc_buftarg(mp, rtdev, dax_rtdev);
+		mp->m_rtdev_targp = xfs_alloc_buftarg(mp, rtdev);
 		if (!mp->m_rtdev_targp)
 			goto out_free_ddev_targ;
 	}
 
 	if (logdev && logdev != ddev) {
-		mp->m_logdev_targp = xfs_alloc_buftarg(mp, logdev, dax_logdev);
+		mp->m_logdev_targp = xfs_alloc_buftarg(mp, logdev);
 		if (!mp->m_logdev_targp)
 			goto out_free_rtdev_targ;
 	} else {
@@ -467,14 +477,9 @@ xfs_open_devices(
 	xfs_free_buftarg(mp->m_ddev_targp);
  out_close_rtdev:
 	xfs_blkdev_put(rtdev);
-	fs_put_dax(dax_rtdev);
  out_close_logdev:
-	if (logdev && logdev != ddev) {
+	if (logdev && logdev != ddev)
 		xfs_blkdev_put(logdev);
-		fs_put_dax(dax_logdev);
-	}
- out:
-	fs_put_dax(dax_ddev);
 	return error;
 }
 
@@ -1593,26 +1598,9 @@ xfs_fs_fill_super(
 		sb->s_flags |= SB_I_VERSION;
 
 	if (xfs_has_dax_always(mp)) {
-		bool rtdev_is_dax = false, datadev_is_dax;
-
-		xfs_warn(mp,
-		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
-
-		datadev_is_dax = xfs_buftarg_is_dax(sb, mp->m_ddev_targp);
-		if (mp->m_rtdev_targp)
-			rtdev_is_dax = xfs_buftarg_is_dax(sb,
-						mp->m_rtdev_targp);
-		if (!rtdev_is_dax && !datadev_is_dax) {
-			xfs_alert(mp,
-			"DAX unsupported by block device. Turning off DAX.");
-			xfs_mount_set_dax_mode(mp, XFS_DAX_NEVER);
-		}
-		if (xfs_has_reflink(mp)) {
-			xfs_alert(mp,
-		"DAX and reflink cannot be used together!");
-			error = -EINVAL;
+		error = xfs_setup_dax_always(mp);
+		if (error)
 			goto out_filestream_unmount;
-		}
 	}
 
 	if (xfs_has_discard(mp)) {