[PATCH v8 5/7] fsdax: Dedup file range to use a compare function

With dax we cannot deal with readpage() etc. So, we create a dax comparison function which is similar with vfs_dedupe_file_range_compare(). And introduce dax_remap_file_range_prep() for filesystem use. Signed-off-by: Goldwyn Rodrigues Signed-off-by: Shiyang Ruan Reviewed-by: Darrick J. Wong

[PATCH v8 6/7] 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. Add an implementation of ->iomap_end() for dax write ops to do the remapping work. Signed-off-by: Shiyang Ruan --- fs/dax.c | 39

[PATCH v8 4/7] fsdax: Add dax_iomap_cow_copy() for dax_iomap_zero

Punch hole on a reflinked file needs dax_iomap_cow_copy() too. Otherwise, data in not aligned area will be not correct. So, add the srcmap to dax_iomap_zero() and replace memset() as dax_iomap_cow_copy(). Signed-off-by: Shiyang Ruan Reviewed-by: Ritesh Harjani Reviewed-by: Darrick J. Wong ---

[PATCH v8 3/7] fsdax: Replace mmap entry in case of CoW

We replace the existing entry to the newly allocated one in case of CoW. Also, we mark the entry as PAGECACHE_TAG_TOWRITE so writeback marks this entry as writeprotected. This helps us snapshots so new write pagefaults after snapshots trigger a CoW. Signed-off-by: Goldwyn Rodrigues

[PATCH v8 0/7] fsdax,xfs: Add reflink support for fsdax

This patchset is attempt to add CoW support for fsdax, and take XFS, which has both reflink and fsdax feature, as an example. Changes from V7: - Patch 3: Update to iter model[1] - Patch 4: Add the missing memset() in CoW case - Remove iomap_iter2(), use 2 nested iomap_iter() instead - Patch

[PATCH v8 2/7] fsdax: Introduce dax_iomap_cow_copy()

In the case where the iomap is a write operation and iomap is not equal to srcmap after iomap_begin, we consider it is a CoW operation. In this case, the destination (iomap->addr) points to a newly allocated extent. It is needed to copy the data from srcmap to the extent. In theory, it is

[PATCH v8 1/7] fsdax: Output address in dax_iomap_pfn() and rename it

Add address output in dax_iomap_pfn() in order to perform a memcpy() in CoW case. Since this function both output address and pfn, rename it to dax_iomap_direct_access(). Signed-off-by: Shiyang Ruan Reviewed-by: Christoph Hellwig Reviewed-by: Ritesh Harjani Reviewed-by: Dan Williams ---

[PATCH v8 7/7] xfs: Add dax dedupe support

Introduce xfs_mmaplock_two_inodes_and_break_dax_layout() for dax files who are going to be deduped. After that, call compare range function only when files are both DAX or not. Signed-off-by: Shiyang Ruan Reviewed-by: Darrick J. Wong --- fs/xfs/xfs_file.c| 2 +- fs/xfs/xfs_inode.c | 57