[PATCH 1/2] ocfs2: Add group extend for online resize

This patch adds the ability for a userspace program to request an extend of
last cluster group on an Ocfs2 file system. The request is made via ioctl,
OCFS2_IOC_GROUP_EXTEND. This is derived from EXT3_IOC_GROUP_EXTEND, but is
obviously Ocfs2 specific.

tunefs.ocfs2 would call this for an online-resize operation if the last
cluster group isn't full.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/ocfs2_fs.h b/fs/ocfs2/ocfs2_fs.h
index 6ef8767..19ac421b 100644
--- a/fs/ocfs2/ocfs2_fs.h
+++ b/fs/ocfs2/ocfs2_fs.h
@@ -231,6 +231,8 @@
 #define OCFS2_IOC_RESVSP64	_IOW ('X', 42, struct ocfs2_space_resv)
 #define OCFS2_IOC_UNRESVSP64	_IOW ('X', 43, struct ocfs2_space_resv)
 
+#define OCFS2_IOC_GROUP_EXTEND	_IOW('o', 1, int)
+
 /*
  * Journal Flags (ocfs2_dinode.id1.journal1.i_flags)
  */