Merge tag 'libnvdimm-for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm updates from Dan Williams:
 "The bulk of this has been in multiple -next releases. There were a few
  late breaking fixes and small features that got added in the last
  couple days, but the whole set has received a build success
  notification from the kbuild robot.

  Change summary:

   - Region media error reporting: A libnvdimm region device is the
     parent to one or more namespaces. To date, media errors have been
     reported via the "badblocks" attribute attached to pmem block
     devices for namespaces in "raw" or "memory" mode. Given that
     namespaces can be in "device-dax" or "btt-sector" mode this new
     interface reports media errors generically, i.e. independent of
     namespace modes or state.

     This subsequently allows userspace tooling to craft "ACPI 6.1
     Section 9.20.7.6 Function Index 4 - Clear Uncorrectable Error"
     requests and submit them via the ioctl path for NVDIMM root bus
     devices.

   - Introduce 'struct dax_device' and 'struct dax_operations': Prompted
     by a request from Linus and feedback from Christoph this allows for
     dax capable drivers to publish their own custom dax operations.
     This fixes the broken assumption that all dax operations are
     related to a persistent memory device, and makes it easier for
     other architectures and platforms to add customized persistent
     memory support.

   - 'libnvdimm' core updates: A new "deep_flush" sysfs attribute is
     available for storage appliance applications to manually trigger
     memory controllers to drain write-pending buffers that would
     otherwise be flushed automatically by the platform ADR
     (asynchronous-DRAM-refresh) mechanism at a power loss event.
     Support for "locked" DIMMs is included to prevent namespaces from
     surfacing when the namespace label data area is locked. Finally,
     fixes for various reported deadlocks and crashes, also tagged for
     -stable.

   - ACPI / nfit driver updates: General updates of the nfit driver to
     add DSM command overrides, ACPI 6.1 health state flags support, DSM
     payload debug available by default, and various fixes.

  Acknowledgements that came after the branch was pushed:

   - commmit 565851c972b5 "device-dax: fix sysfs attribute deadlock":
     Tested-by: Yi Zhang <yizhan@redhat.com>

   - commit 23f498448362 "libnvdimm: rework region badblocks clearing"
     Tested-by: Toshi Kani <toshi.kani@hpe.com>"

* tag 'libnvdimm-for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (52 commits)
  libnvdimm, pfn: fix 'npfns' vs section alignment
  libnvdimm: handle locked label storage areas
  libnvdimm: convert NDD_ flags to use bitops, introduce NDD_LOCKED
  brd: fix uninitialized use of brd->dax_dev
  block, dax: use correct format string in bdev_dax_supported
  device-dax: fix sysfs attribute deadlock
  libnvdimm: restore "libnvdimm: band aid btt vs clear poison locking"
  libnvdimm: fix nvdimm_bus_lock() vs device_lock() ordering
  libnvdimm: rework region badblocks clearing
  acpi, nfit: kill ACPI_NFIT_DEBUG
  libnvdimm: fix clear length of nvdimm_forget_poison()
  libnvdimm, pmem: fix a NULL pointer BUG in nd_pmem_notify
  libnvdimm, region: sysfs trigger for nvdimm_flush()
  libnvdimm: fix phys_addr for nvdimm_clear_poison
  x86, dax, pmem: remove indirection around memcpy_from_pmem()
  block: remove block_device_operations ->direct_access()
  block, dax: convert bdev_dax_supported() to dax_direct_access()
  filesystem-dax: convert to dax_direct_access()
  Revert "block: use DAX for partition table reads"
  ext2, ext4, xfs: retrieve dax_device for iomap operations
  ...

1 files changed, 35 insertions, 82 deletions

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 0d435c794d76..2a305c1a2d88 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -18,6 +18,7 @@
 #include <linux/module.h>
 #include <linux/blkpg.h>
 #include <linux/magic.h>
+#include <linux/dax.h>
 #include <linux/buffer_head.h>
 #include <linux/swap.h>
 #include <linux/pagevec.h>
@@ -716,50 +717,18 @@ int bdev_write_page(struct block_device *bdev, sector_t sector,
 }
 EXPORT_SYMBOL_GPL(bdev_write_page);
 
-/**
- * bdev_direct_access() - Get the address for directly-accessibly memory
- * @bdev: The device containing the memory
- * @dax: control and output parameters for ->direct_access
- *
- * If a block device is made up of directly addressable memory, this function
- * will tell the caller the PFN and the address of the memory.  The address
- * may be directly dereferenced within the kernel without the need to call
- * ioremap(), kmap() or similar.  The PFN is suitable for inserting into
- * page tables.
- *
- * Return: negative errno if an error occurs, otherwise the number of bytes
- * accessible at this address.
- */
-long bdev_direct_access(struct block_device *bdev, struct blk_dax_ctl *dax)
+int bdev_dax_pgoff(struct block_device *bdev, sector_t sector, size_t size,
+		pgoff_t *pgoff)
 {
-	sector_t sector = dax->sector;
-	long avail, size = dax->size;
-	const struct block_device_operations *ops = bdev->bd_disk->fops;
+	phys_addr_t phys_off = (get_start_sect(bdev) + sector) * 512;
 
-	/*
-	 * The device driver is allowed to sleep, in order to make the
-	 * memory directly accessible.
-	 */
-	might_sleep();
-
-	if (size < 0)
-		return size;
-	if (!blk_queue_dax(bdev_get_queue(bdev)) || !ops->direct_access)
-		return -EOPNOTSUPP;
-	if ((sector + DIV_ROUND_UP(size, 512)) >
-					part_nr_sects_read(bdev->bd_part))
-		return -ERANGE;
-	sector += get_start_sect(bdev);
-	if (sector % (PAGE_SIZE / 512))
+	if (pgoff)
+		*pgoff = PHYS_PFN(phys_off);
+	if (phys_off % PAGE_SIZE || size % PAGE_SIZE)
 		return -EINVAL;
-	avail = ops->direct_access(bdev, sector, &dax->addr, &dax->pfn, size);
-	if (!avail)
-		return -ERANGE;
-	if (avail > 0 && avail & ~PAGE_MASK)
-		return -ENXIO;
-	return min(avail, size);
+	return 0;
 }
-EXPORT_SYMBOL_GPL(bdev_direct_access);
+EXPORT_SYMBOL(bdev_dax_pgoff);
 
 /**
  * bdev_dax_supported() - Check if the device supports dax for filesystem
@@ -773,62 +742,46 @@ EXPORT_SYMBOL_GPL(bdev_direct_access);
  */
 int bdev_dax_supported(struct super_block *sb, int blocksize)
 {
-	struct blk_dax_ctl dax = {
-		.sector = 0,
-		.size = PAGE_SIZE,
-	};
-	int err;
+	struct block_device *bdev = sb->s_bdev;
+	struct dax_device *dax_dev;
+	pgoff_t pgoff;
+	int err, id;
+	void *kaddr;
+	pfn_t pfn;
+	long len;
 
 	if (blocksize != PAGE_SIZE) {
 		vfs_msg(sb, KERN_ERR, "error: unsupported blocksize for dax");
 		return -EINVAL;
 	}
 
-	err = bdev_direct_access(sb->s_bdev, &dax);
-	if (err < 0) {
-		switch (err) {
-		case -EOPNOTSUPP:
-			vfs_msg(sb, KERN_ERR,
-				"error: device does not support dax");
-			break;
-		case -EINVAL:
-			vfs_msg(sb, KERN_ERR,
-				"error: unaligned partition for dax");
-			break;
-		default:
-			vfs_msg(sb, KERN_ERR,
-				"error: dax access failed (%d)", err);
-		}
+	err = bdev_dax_pgoff(bdev, 0, PAGE_SIZE, &pgoff);
+	if (err) {
+		vfs_msg(sb, KERN_ERR, "error: unaligned partition for dax");
 		return err;
 	}
 
-	return 0;
-}
-EXPORT_SYMBOL_GPL(bdev_dax_supported);
-
-/**
- * bdev_dax_capable() - Return if the raw device is capable for dax
- * @bdev: The device for raw block device access
- */
-bool bdev_dax_capable(struct block_device *bdev)
-{
-	struct blk_dax_ctl dax = {
-		.size = PAGE_SIZE,
-	};
+	dax_dev = dax_get_by_host(bdev->bd_disk->disk_name);
+	if (!dax_dev) {
+		vfs_msg(sb, KERN_ERR, "error: device does not support dax");
+		return -EOPNOTSUPP;
+	}
 
-	if (!IS_ENABLED(CONFIG_FS_DAX))
-		return false;
+	id = dax_read_lock();
+	len = dax_direct_access(dax_dev, pgoff, 1, &kaddr, &pfn);
+	dax_read_unlock(id);
 
-	dax.sector = 0;
-	if (bdev_direct_access(bdev, &dax) < 0)
-		return false;
+	put_dax(dax_dev);
 
-	dax.sector = bdev->bd_part->nr_sects - (PAGE_SIZE / 512);
-	if (bdev_direct_access(bdev, &dax) < 0)
-		return false;
+	if (len < 1) {
+		vfs_msg(sb, KERN_ERR,
+				"error: dax access failed (%ld)", len);
+		return len < 0 ? len : -EIO;
+	}
 
-	return true;
+	return 0;
 }
+EXPORT_SYMBOL_GPL(bdev_dax_supported);
 
 /*
  * pseudo-fs