1 files changed, 20 insertions, 16 deletions

diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 5b81f7f41b80..33c389934238 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -871,22 +871,6 @@ xfs_setattr_size(
 		return error;
 
 	/*
-	 * We are going to log the inode size change in this transaction so
-	 * any previous writes that are beyond the on disk EOF and the new
-	 * EOF that have not been written out need to be written here.  If we
-	 * do not write the data out, we expose ourselves to the null files
-	 * problem. Note that this includes any block zeroing we did above;
-	 * otherwise those blocks may not be zeroed after a crash.
-	 */
-	if (did_zeroing ||
-	    (newsize > ip->i_d.di_size && oldsize != ip->i_d.di_size)) {
-		error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
-						      ip->i_d.di_size, newsize);
-		if (error)
-			return error;
-	}
-
-	/*
 	 * We've already locked out new page faults, so now we can safely remove
 	 * pages from the page cache knowing they won't get refaulted until we
 	 * drop the XFS_MMAP_EXCL lock after the extent manipulations are
@@ -902,9 +886,29 @@ xfs_setattr_size(
 	 * user visible changes). There's not much we can do about this, except
 	 * to hope that the caller sees ENOMEM and retries the truncate
 	 * operation.
+	 *
+	 * And we update in-core i_size and truncate page cache beyond newsize
+	 * before writeback the [di_size, newsize] range, so we're guaranteed
+	 * not to write stale data past the new EOF on truncate down.
 	 */
 	truncate_setsize(inode, newsize);
 
+	/*
+	 * We are going to log the inode size change in this transaction so
+	 * any previous writes that are beyond the on disk EOF and the new
+	 * EOF that have not been written out need to be written here.  If we
+	 * do not write the data out, we expose ourselves to the null files
+	 * problem. Note that this includes any block zeroing we did above;
+	 * otherwise those blocks may not be zeroed after a crash.
+	 */
+	if (did_zeroing ||
+	    (newsize > ip->i_d.di_size && oldsize != ip->i_d.di_size)) {
+		error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
+						ip->i_d.di_size, newsize - 1);
+		if (error)
+			return error;
+	}
+
 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
 	if (error)
 		return error;