[RFC PATCH v2 0/7] xfs: reflink & dedupe for fsdax (read/write path).

[Shiyang Ruan]

This patchset aims to take care of this issue to make reflink and dedupe
work correctly (actually in read/write path, there still has some problems,
such as the page->mapping and page->index issue, in mmap path) in XFS under
fsdax mode.

It is based on Goldwyn's patchsets: "v4 Btrfs dax support" and the latest
iomap.  I borrowed some patches related and made a few fix to make it
basically works fine.

For dax framework: 
  1. adapt to the latest change in iomap (two iomaps).

For XFS:
  1. distinguish dax write/zero from normal write/zero.
  2. remap extents after COW.
  3. add file contents comparison function based on dax framework.
  4. use xfs_break_layouts() instead of break_layout to support dax.


Goldwyn Rodrigues (3):
  dax: replace mmap entry in case of CoW
  fs: dedup file range to use a compare function
  dax: memcpy before zeroing range

Shiyang Ruan (4):
  dax: Introduce dax_copy_edges() for COW.
  dax: copy data before write.
  xfs: handle copy-on-write in fsdax write() path.
  xfs: support dedupe for fsdax.

 fs/btrfs/ioctl.c       |   3 +-
 fs/dax.c               | 211 +++++++++++++++++++++++++++++++++++++----
 fs/iomap/buffered-io.c |   8 +-
 fs/ocfs2/file.c        |   2 +-
 fs/read_write.c        |  11 ++-
 fs/xfs/xfs_bmap_util.c |   6 +-
 fs/xfs/xfs_file.c      |  10 +-
 fs/xfs/xfs_iomap.c     |   3 +-
 fs/xfs/xfs_iops.c      |  11 ++-
 fs/xfs/xfs_reflink.c   |  79 ++++++++-------
 include/linux/dax.h    |  16 ++--
 include/linux/fs.h     |   9 +-
 12 files changed, 291 insertions(+), 78 deletions(-)

-- 
2.23.0