This patchset is a try to resolve the shared 'page cache' problem for fsdax. In order to track multiple mappings and indexes on one page, I introduced a dax-rmap rb-tree to manage the relationship. A dax entry will be associated more than once if is shared. At the second time we associate this entry, we create this rb-tree and store its root in page->private(not used in fsdax). Insert (->mapping, ->index) when dax_associate_entry() and delete it when dax_disassociate_entry(). We can iterate the dax-rmap rb-tree before any other operations on mappings of files. Such as memory-failure and rmap. Same as before, I borrowed and made some changes on Goldwyn's patchsets. These patches makes up for the lack of CoW mechanism in fsdax. The rests are dax & reflink support for xfs. (Rebased to 5.7-rc2) Shiyang Ruan (8): fs/dax: Introduce dax-rmap btree for reflink mm: add dax-rmap for memory-failure and rmap fs/dax: Introduce dax_copy_edges() for COW fs/dax: copy data before write fs/dax: replace mmap entry in case of CoW fs/dax: dedup file range to use a compare function fs/xfs: handle CoW for fsdax write() path fs/xfs: support dedupe for fsdax fs/dax.c | 343 +++++++++++++++++++++++++++++++++++++---- 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 | 11 ++ include/linux/fs.h | 9 +- mm/memory-failure.c | 63 ++++++-- mm/rmap.c | 54 +++++-- 12 files changed, 498 insertions(+), 104 deletions(-) -- 2.26.2
