Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm fixes from Dan Williams:
 "1/ Fixes to the libnvdimm 'pfn' device that establishes a reserved
     area for storing a struct page array.

  2/ Fixes for dax operations on a raw block device to prevent pagecache
     collisions with dax mappings.

  3/ A fix for pfn_t usage in vm_insert_mixed that lead to a null
     pointer de-reference.

  These have received build success notification from the kbuild robot
  across 153 configs and pass the latest ndctl tests"

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  phys_to_pfn_t: use phys_addr_t
  mm: fix pfn_t to page conversion in vm_insert_mixed
  block: use DAX for partition table reads
  block: revert runtime dax control of the raw block device
  fs, block: force direct-I/O for dax-enabled block devices
  devm_memremap_pages: fix vmem_altmap lifetime + alignment handling
  libnvdimm, pfn: fix restoring memmap location
  libnvdimm: fix mode determination for e820 devices

block/ioctl.c

@@ -434,42 +434,6 @@ bool blkdev_dax_capable(struct block_device *bdev)
 
 	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;
-
-	inode_lock(bdev->bd_inode);
-	if (bdev->bd_map_count == 0)
-		inode_set_flags(bdev->bd_inode, arg, S_DAX);
-	else
-		rc = -EBUSY;
-	inode_unlock(bdev->bd_inode);
-	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,
@@ -634,8 +598,6 @@ 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;

block/partition-generic.c

@@ -16,6 +16,7 @@
 #include <linux/kmod.h>
 #include <linux/ctype.h>
 #include <linux/genhd.h>
+#include <linux/dax.h>
 #include <linux/blktrace_api.h>
 
 #include "partitions/check.h"
@@ -550,13 +551,24 @@ int invalidate_partitions(struct gendisk *disk, struct block_device *bdev)
 	return 0;
 }
 
-unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
+static struct page *read_pagecache_sector(struct block_device *bdev, sector_t n)
 {
 	struct address_space *mapping = bdev->bd_inode->i_mapping;
+
+	return read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
+			NULL);
+}
+
+unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
+{
 	struct page *page;
 
-	page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
-				 NULL);
+	/* don't populate page cache for dax capable devices */
+	if (IS_DAX(bdev->bd_inode))
+		page = read_dax_sector(bdev, n);
+	else
+		page = read_pagecache_sector(bdev, n);
+
 	if (!IS_ERR(page)) {
 		if (PageError(page))
 			goto fail;