1 files changed, 15 insertions, 16 deletions

diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index 22a5dcb70b32..7efa23e72a90 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -1599,13 +1599,6 @@ xfs_swap_extent_flush(
         /* Verify O_DIRECT for ftmp */
         if (VFS_I(ip)->i_mapping->nrpages)
                 return -EINVAL;
-
-        /*
-         * Don't try to swap extents on mmap()d files because we can't lock
-         * out races against page faults safely.
-         */
-        if (mapping_mapped(VFS_I(ip)->i_mapping))
-                return -EBUSY;
         return 0;
 }
 
@@ -1633,13 +1626,14 @@ xfs_swap_extents(
         }
 
         /*
-         * Lock up the inodes against other IO and truncate to begin with.
-         * Then we can ensure the inodes are flushed and have no page cache
-         * safely. Once we have done this we can take the ilocks and do the rest
-         * of the checks.
+         * Lock the inodes against other IO, page faults and truncate to
+         * begin with.  Then we can ensure the inodes are flushed and have no
+         * page cache safely. Once we have done this we can take the ilocks and
+         * do the rest of the checks.
          */
-        lock_flags = XFS_IOLOCK_EXCL;
+        lock_flags = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
         xfs_lock_two_inodes(ip, tip, XFS_IOLOCK_EXCL);
+        xfs_lock_two_inodes(ip, tip, XFS_MMAPLOCK_EXCL);
 
         /* Verify that both files have the same format */
         if ((ip->i_d.di_mode & S_IFMT) != (tip->i_d.di_mode & S_IFMT)) {
@@ -1666,8 +1660,16 @@ xfs_swap_extents(
                 xfs_trans_cancel(tp, 0);
                 goto out_unlock;
         }
+
+        /*
+         * Lock and join the inodes to the tansaction so that transaction commit
+         * or cancel will unlock the inodes from this point onwards.
+         */
         xfs_lock_two_inodes(ip, tip, XFS_ILOCK_EXCL);
         lock_flags |= XFS_ILOCK_EXCL;
+        xfs_trans_ijoin(tp, ip, lock_flags);
+        xfs_trans_ijoin(tp, tip, lock_flags);
+
 
         /* Verify all data are being swapped */
         if (sxp->sx_offset != 0 ||
@@ -1720,9 +1722,6 @@ xfs_swap_extents(
                         goto out_trans_cancel;
         }
 
-        xfs_trans_ijoin(tp, ip, lock_flags);
-        xfs_trans_ijoin(tp, tip, lock_flags);
-
         /*
          * Before we've swapped the forks, lets set the owners of the forks
          * appropriately. We have to do this as we are demand paging the btree
@@ -1856,5 +1855,5 @@ out_unlock:
 
 out_trans_cancel:
         xfs_trans_cancel(tp, 0);
-        goto out_unlock;
+        goto out;
 }