• Linus Torvalds's avatar
    Merge tag 'libnvdimm-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm · 7d3bf613
    Linus Torvalds authored
    Pull libnvdimm updates from Dan Williams:
     "This adds a user for the new 'bytes-remaining' updates to
      memcpy_mcsafe() that you already received through Ingo via the
      x86-dax- for-linus pull.
      Not included here, but still targeting this cycle, is support for
      handling memory media errors (poison) consumed via userspace dax
       - DAX broke a fundamental assumption of truncate of file mapped
         pages. The truncate path assumed that it is safe to disconnect a
         pinned page from a file and let the filesystem reclaim the physical
         block. With DAX the page is equivalent to the filesystem block.
         Introduce dax_layout_busy_page() to enable filesystems to wait for
         pinned DAX pages to be released. Without this wait a filesystem
         could allocate blocks under active device-DMA to a new file.
       - DAX arranges for the block layer to be bypassed and uses
         dax_direct_access() + copy_to_iter() to satisfy read(2) calls.
         However, the memcpy_mcsafe() facility is available through the pmem
         block driver. In order to safely handle media errors, via the DAX
         block-layer bypass, introduce copy_to_iter_mcsafe().
       - Fix cache management policy relative to the ACPI NFIT Platform
         Capabilities Structure to properly elide cache flushes when they
         are not necessary. The table indicates whether CPU caches are
         power-fail protected. Clarify that a deep flush is always performed
         on REQ_{FUA,PREFLUSH} requests"
    * tag 'libnvdimm-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (21 commits)
      dax: Use dax_write_cache* helpers
      libnvdimm, pmem: Do not flush power-fail protected CPU caches
      libnvdimm, pmem: Unconditionally deep flush on *sync
      libnvdimm, pmem: Complete REQ_FLUSH => REQ_PREFLUSH
      acpi, nfit: Remove ecc_unit_size
      dax: dax_insert_mapping_entry always succeeds
      libnvdimm, e820: Register all pmem resources
      libnvdimm: Debug probe times
      linvdimm, pmem: Preserve read-only setting for pmem devices
      x86, nfit_test: Add unit test for memcpy_mcsafe()
      pmem: Switch to copy_to_iter_mcsafe()
      dax: Report bytes remaining in dax_iomap_actor()
      dax: Introduce a ->copy_to_iter dax operation
      uio, lib: Fix CONFIG_ARCH_HAS_UACCESS_MCSAFE compilation
      xfs, dax: introduce xfs_break_dax_layouts()
      xfs: prepare xfs_break_layouts() for another layout type
      xfs: prepare xfs_break_layouts() to be called with XFS_MMAPLOCK_EXCL
      mm, fs, dax: handle layout changes to pinned dax mappings
      mm: fix __gup_device_huge vs unmap
dax.c 46.7 KB