ext4: fix online resize with mballoc

Update group infos when updating a group's descriptor.
Add group infos when adding a group's descriptor.
Refresh cache pages used by mb_alloc when changes occur.
This will probably need modifications when META_BG resizing will be allowed.

Signed-off-by: Frederic Bohe <frederic.bohe@bull.net>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 2c4b485..64edb09 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1033,6 +1033,10 @@
 extern void exit_ext4_mballoc(void);
 extern void ext4_mb_free_blocks(handle_t *, struct inode *,
 		unsigned long, unsigned long, int, unsigned long *);
+extern int ext4_mb_add_more_groupinfo(struct super_block *sb,
+		ext4_group_t i, struct ext4_group_desc *desc);
+extern void ext4_mb_update_group_info(struct ext4_group_info *grp,
+		ext4_grpblk_t add);
 
 
 /* inode.c */