ocfs2: add extent block stealing for ocfs2 v5

This patch add extent block (metadata) stealing mechanism for
extent allocation. This mechanism is same as the inode stealing.
if no room in slot specific extent_alloc, we will try to
allocate extent block from the next slot.

Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Acked-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
diff --git a/fs/ocfs2/suballoc.h b/fs/ocfs2/suballoc.h
index 8c9a78a..fa60723 100644
--- a/fs/ocfs2/suballoc.h
+++ b/fs/ocfs2/suballoc.h
@@ -56,6 +56,7 @@
 				 is the same as ~0 - unlimited */
 };
 
+void ocfs2_init_steal_slots(struct ocfs2_super *osb);
 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac);
 static inline int ocfs2_alloc_context_bits_left(struct ocfs2_alloc_context *ac)
 {