Merge tag 'libnvdimm-for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm updates from Dan Williams:
 "The bulk of this has appeared in -next and independently received a
  build success notification from the kbuild robot.  The 'for-4.5/block-
  dax' topic branch was rebased over the weekend to drop the "block
  device end-of-life" rework that Al would like to see re-implemented
  with a notifier, and to address bug reports against the badblocks
  integration.

  There is pending feedback against "libnvdimm: Add a poison list and
  export badblocks" received last week.  Linda identified some localized
  fixups that we will handle incrementally.

  Summary:

   - Media error handling: The 'badblocks' implementation that
     originated in md-raid is up-levelled to a generic capability of a
     block device.  This initial implementation is limited to being
     consulted in the pmem block-i/o path.  Later, 'badblocks' will be
     consulted when creating dax mappings.

   - Raw block device dax: For virtualization and other cases that want
     large contiguous mappings of persistent memory, add the capability
     to dax-mmap a block device directly.

   - Increased /dev/mem restrictions: Add an option to treat all
     io-memory as IORESOURCE_EXCLUSIVE, i.e. disable /dev/mem access
     while a driver is actively using an address range.  This behavior
     is controlled via the new CONFIG_IO_STRICT_DEVMEM option and can be
     overridden by the existing "iomem=relaxed" kernel command line
     option.

   - Miscellaneous fixes include a 'pfn'-device huge page alignment fix,
     block device shutdown crash fix, and other small libnvdimm fixes"

* tag 'libnvdimm-for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (32 commits)
  block: kill disk_{check|set|clear|alloc}_badblocks
  libnvdimm, pmem: nvdimm_read_bytes() badblocks support
  pmem, dax: disable dax in the presence of bad blocks
  pmem: fail io-requests to known bad blocks
  libnvdimm: convert to statically allocated badblocks
  libnvdimm: don't fail init for full badblocks list
  block, badblocks: introduce devm_init_badblocks
  block: clarify badblocks lifetime
  badblocks: rename badblocks_free to badblocks_exit
  libnvdimm, pmem: move definition of nvdimm_namespace_add_poison to nd.h
  libnvdimm: Add a poison list and export badblocks
  nfit_test: Enable DSMs for all test NFITs
  md: convert to use the generic badblocks code
  block: Add badblock management for gendisks
  badblocks: Add core badblock management code
  block: fix del_gendisk() vs blkdev_ioctl crash
  block: enable dax for raw block devices
  block: introduce bdev_file_inode()
  restrict /dev/mem to idle io memory ranges
  arch: consolidate CONFIG_STRICT_DEVM in lib/Kconfig.debug
  ...

1 files changed, 71 insertions, 0 deletions

diff --git a/block/ioctl.c b/block/ioctl.c
index 0918aed2d847..2c84683aada5 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -4,6 +4,7 @@
 #include <linux/gfp.h>
 #include <linux/blkpg.h>
 #include <linux/hdreg.h>
+#include <linux/badblocks.h>
 #include <linux/backing-dev.h>
 #include <linux/fs.h>
 #include <linux/blktrace_api.h>
@@ -406,6 +407,71 @@ static inline int is_unrecognized_ioctl(int ret)
 		ret == -ENOIOCTLCMD;
 }
 
+#ifdef CONFIG_FS_DAX
+bool blkdev_dax_capable(struct block_device *bdev)
+{
+	struct gendisk *disk = bdev->bd_disk;
+
+	if (!disk->fops->direct_access)
+		return false;
+
+	/*
+	 * If the partition is not aligned on a page boundary, we can't
+	 * do dax I/O to it.
+	 */
+	if ((bdev->bd_part->start_sect % (PAGE_SIZE / 512))
+			|| (bdev->bd_part->nr_sects % (PAGE_SIZE / 512)))
+		return false;
+
+	/*
+	 * If the device has known bad blocks, force all I/O through the
+	 * driver / page cache.
+	 *
+	 * TODO: support finer grained dax error handling
+	 */
+	if (disk->bb && disk->bb->count)
+		return false;
+
+	return true;
+}
+
+static int blkdev_daxset(struct block_device *bdev, unsigned long argp)
+{
+	unsigned long arg;
+	int rc = 0;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
+	if (get_user(arg, (int __user *)(argp)))
+		return -EFAULT;
+	arg = !!arg;
+	if (arg == !!(bdev->bd_inode->i_flags & S_DAX))
+		return 0;
+
+	if (arg)
+		arg = S_DAX;
+
+	if (arg && !blkdev_dax_capable(bdev))
+		return -ENOTTY;
+
+	mutex_lock(&bdev->bd_inode->i_mutex);
+	if (bdev->bd_map_count == 0)
+		inode_set_flags(bdev->bd_inode, arg, S_DAX);
+	else
+		rc = -EBUSY;
+	mutex_unlock(&bdev->bd_inode->i_mutex);
+	return rc;
+}
+#else
+static int blkdev_daxset(struct block_device *bdev, int arg)
+{
+	if (arg)
+		return -ENOTTY;
+	return 0;
+}
+#endif
+
 static int blkdev_flushbuf(struct block_device *bdev, fmode_t mode,
 		unsigned cmd, unsigned long arg)
 {
@@ -568,6 +634,11 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
 	case BLKTRACESETUP:
 	case BLKTRACETEARDOWN:
 		return blk_trace_ioctl(bdev, cmd, argp);
+	case BLKDAXSET:
+		return blkdev_daxset(bdev, arg);
+	case BLKDAXGET:
+		return put_int(arg, !!(bdev->bd_inode->i_flags & S_DAX));
+		break;
 	case IOC_PR_REGISTER:
 		return blkdev_pr_register(bdev, argp);
 	case IOC_PR_RESERVE: