Merge tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git...

[sfrench/cifs-2.6.git] / fs / xfs / xfs_inode.c

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 3022918bf96ac74c3da33e53aa569ad23e77b56a..28493c8e9bb231accb53884e1fd126c9d366c407 100644 (file)
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -3447,6 +3447,50 @@ 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.
@@ -3461,8 +3505,19 @@ 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;
 }
 
@@ -3472,8 +3527,14 @@ 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));