Merge tag 'dax-misc-for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull misc DAX updates from Vishal Verma:
 "DAX error handling for 4.7

   - Until now, dax has been disabled if media errors were found on any
     device.  This enables the use of DAX in the presence of these
     errors by making all sector-aligned zeroing go through the driver.

   - The driver (already) has the ability to clear errors on writes that
     are sent through the block layer using 'DSMs' defined in ACPI 6.1.

  Other misc changes:

   - When mounting DAX filesystems, check to make sure the partition is
     page aligned.  This is a requirement for DAX, and previously, we
     allowed such unaligned mounts to succeed, but subsequent
     reads/writes would fail.

   - Misc/cleanup fixes from Jan that remove unused code from DAX
     related to zeroing, writeback, and some size checks"

* tag 'dax-misc-for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  dax: fix a comment in dax_zero_page_range and dax_truncate_page
  dax: for truncate/hole-punch, do zeroing through the driver if possible
  dax: export a low-level __dax_zero_page_range helper
  dax: use sb_issue_zerout instead of calling dax_clear_sectors
  dax: enable dax in the presence of known media errors (badblocks)
  dax: fallback from pmd to pte on error
  block: Update blkdev_dax_capable() for consistency
  xfs: Add alignment check for DAX mount
  ext2: Add alignment check for DAX mount
  ext4: Add alignment check for DAX mount
  block: Add bdev_dax_supported() for dax mount checks
  block: Add vfs_msg() interface
  dax: Remove redundant inode size checks
  dax: Remove pointless writeback from dax_do_io()
  dax: Remove zeroing from dax_io()
  dax: Remove dead zeroing code from fault handlers
  ext2: Avoid DAX zeroing to corrupt data
  ext2: Fix block zeroing in ext2_get_blocks() for DAX
  dax: Remove complete_unwritten argument
  DAX: move RADIX_DAX_ definitions to dax.c

3 files changed, 12 insertions, 4 deletions

diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index 51a071e32221..c04bd9bc39fd 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -381,7 +381,7 @@ static int brd_rw_page(struct block_device *bdev, sector_t sector,
 
 #ifdef CONFIG_BLK_DEV_RAM_DAX
 static long brd_direct_access(struct block_device *bdev, sector_t sector,
-                        void __pmem **kaddr, pfn_t *pfn)
+                        void __pmem **kaddr, pfn_t *pfn, long size)
 {
         struct brd_device *brd = bdev->bd_disk->private_data;
         struct page *page;
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 042baec56931..608fc4464574 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -164,14 +164,22 @@ static int pmem_rw_page(struct block_device *bdev, sector_t sector,
 }
 
 static long pmem_direct_access(struct block_device *bdev, sector_t sector,
-                      void __pmem **kaddr, pfn_t *pfn)
+                      void __pmem **kaddr, pfn_t *pfn, long size)
 {
         struct pmem_device *pmem = bdev->bd_queue->queuedata;
         resource_size_t offset = sector * 512 + pmem->data_offset;
 
+        if (unlikely(is_bad_pmem(&pmem->bb, sector, size)))
+                return -EIO;
         *kaddr = pmem->virt_addr + offset;
         *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
 
+        /*
+         * If badblocks are present, limit known good range to the
+         * requested range.
+         */
+        if (unlikely(pmem->bb.count))
+                return size;
         return pmem->size - pmem->pfn_pad - offset;
 }
 
diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c
index b83908670a9a..bed53c46dd90 100644
--- a/drivers/s390/block/dcssblk.c
+++ b/drivers/s390/block/dcssblk.c
@@ -31,7 +31,7 @@ static void dcssblk_release(struct gendisk *disk, fmode_t mode);
 static blk_qc_t dcssblk_make_request(struct request_queue *q,
                                                 struct bio *bio);
 static long dcssblk_direct_access(struct block_device *bdev, sector_t secnum,
-                         void __pmem **kaddr, pfn_t *pfn);
+                         void __pmem **kaddr, pfn_t *pfn, long size);
 
 static char dcssblk_segments[DCSSBLK_PARM_LEN] = "\0";
 
@@ -884,7 +884,7 @@ fail:
 
 static long
 dcssblk_direct_access (struct block_device *bdev, sector_t secnum,
-                        void __pmem **kaddr, pfn_t *pfn)
+                        void __pmem **kaddr, pfn_t *pfn, long size)
 {
         struct dcssblk_dev_info *dev_info;
         unsigned long offset, dev_sz;