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.

Link: https://lkml.kernel.org/r/20220603053738.1218681-15-ruansy.fnst@fujitsu.com
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.wiliams@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 45d8e64..92a3af1 100644 (file)
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -808,7 +808,7 @@ xfs_wait_dax_page(
        xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
 }
 
-static int
+int
 xfs_break_dax_layouts(
        struct inode            *inode,
        bool                    *retry)

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 52d6f2c..6f25178 100644 (file)
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -3767,6 +3767,50 @@ retry:
        return 0;
 }
 
+static int
+xfs_mmaplock_two_inodes_and_break_dax_layout(
+       struct xfs_inode        *ip1,
+       struct xfs_inode        *ip2)
+{
+       int                     error;
+       bool                    retry;
+       struct page             *page;
+
+       if (ip1->i_ino > ip2->i_ino)
+               swap(ip1, ip2);
+
+again:
+       retry = false;
+       /* Lock the first inode */
+       xfs_ilock(ip1, XFS_MMAPLOCK_EXCL);
+       error = xfs_break_dax_layouts(VFS_I(ip1), &retry);
+       if (error || retry) {
+               xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
+               if (error == 0 && retry)
+                       goto again;
+               return error;
+       }
+
+       if (ip1 == ip2)
+               return 0;
+
+       /* Nested lock the second inode */
+       xfs_ilock(ip2, xfs_lock_inumorder(XFS_MMAPLOCK_EXCL, 1));
+       /*
+        * We cannot use xfs_break_dax_layouts() directly here because it may
+        * need to unlock & lock the XFS_MMAPLOCK_EXCL which is not suitable
+        * for this nested lock case.
+        */
+       page = dax_layout_busy_page(VFS_I(ip2)->i_mapping);
+       if (page && page_ref_count(page) != 1) {
+               xfs_iunlock(ip2, XFS_MMAPLOCK_EXCL);
+               xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
+               goto again;
+       }
+
+       return 0;
+}
+
 /*
  * Lock two inodes so that userspace cannot initiate I/O via file syscalls or
  * mmap activity.
@@ -3781,8 +3825,19 @@ xfs_ilock2_io_mmap(
        ret = xfs_iolock_two_inodes_and_break_layout(VFS_I(ip1), VFS_I(ip2));
        if (ret)
                return ret;
-       filemap_invalidate_lock_two(VFS_I(ip1)->i_mapping,
-                                   VFS_I(ip2)->i_mapping);
+
+       if (IS_DAX(VFS_I(ip1)) && IS_DAX(VFS_I(ip2))) {
+               ret = xfs_mmaplock_two_inodes_and_break_dax_layout(ip1, ip2);
+               if (ret) {
+                       inode_unlock(VFS_I(ip2));
+                       if (ip1 != ip2)
+                               inode_unlock(VFS_I(ip1));
+                       return ret;
+               }
+       } else
+               filemap_invalidate_lock_two(VFS_I(ip1)->i_mapping,
+                                           VFS_I(ip2)->i_mapping);
+
        return 0;
 }
 
@@ -3792,8 +3847,14 @@ xfs_iunlock2_io_mmap(
        struct xfs_inode        *ip1,
        struct xfs_inode        *ip2)
 {
-       filemap_invalidate_unlock_two(VFS_I(ip1)->i_mapping,
-                                     VFS_I(ip2)->i_mapping);
+       if (IS_DAX(VFS_I(ip1)) && IS_DAX(VFS_I(ip2))) {
+               xfs_iunlock(ip2, XFS_MMAPLOCK_EXCL);
+               if (ip1 != ip2)
+                       xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
+       } else
+               filemap_invalidate_unlock_two(VFS_I(ip1)->i_mapping,
+                                             VFS_I(ip2)->i_mapping);
+
        inode_unlock(VFS_I(ip2));
        if (ip1 != ip2)
                inode_unlock(VFS_I(ip1));

diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 7be6f8e..8313cc8 100644 (file)
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -467,6 +467,7 @@ xfs_itruncate_extents(
 }
 
 /* from xfs_file.c */
+int    xfs_break_dax_layouts(struct inode *inode, bool *retry);
 int    xfs_break_layouts(struct inode *inode, uint *iolock,
                enum layout_break_reason reason);
 

diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index cbaf36d..d07f06f 100644 (file)
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -1363,8 +1363,8 @@ xfs_reflink_remap_prep(
        if (XFS_IS_REALTIME_INODE(src) || XFS_IS_REALTIME_INODE(dest))
                goto out_unlock;
 
-       /* Don't share DAX file data for now. */
-       if (IS_DAX(inode_in) || IS_DAX(inode_out))
+       /* Don't share DAX file data with non-DAX file. */
+       if (IS_DAX(inode_in) != IS_DAX(inode_out))
                goto out_unlock;
 
        if (!IS_DAX(inode_in))