xfs: support CoW in fsdax mode

In fsdax mode, WRITE and ZERO on a shared extent need CoW performed. 
After that, new allocated extents needs to be remapped to the file.  So,
add a CoW identification in ->iomap_begin(), and implement ->iomap_end()
to do the remapping work.

[[email protected]: make xfs_dax_fault() static]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Shiyang Ruan <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Dave Chinner <[email protected]>
Cc: Goldwyn Rodrigues <[email protected]>
Cc: Goldwyn Rodrigues <[email protected]>
Cc: Jane Chu <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Miaohe Lin <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Ritesh Harjani <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions