nilfs2: record used amount of each checkpoint in checkpoint list

This records the number of used blocks per checkpoint in each
checkpoint entry of cpfile.  Even though userland tools can get the
block count via nilfs_get_cpinfo ioctl, it was not updated by the
nilfs2 kernel code.  This fixes the issue and makes it available for
userland tools to calculate used amount per checkpoint.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Jiro SEKIBA <jir@unicus.jp>
diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h
index 45b1fd1..03ba4d8 100644
--- a/fs/nilfs2/nilfs.h
+++ b/fs/nilfs2/nilfs.h
@@ -251,6 +251,8 @@
 				       void **);
 
 /* inode.c */
+void nilfs_inode_add_blocks(struct inode *inode, int n);
+void nilfs_inode_sub_blocks(struct inode *inode, int n);
 extern struct inode *nilfs_new_inode(struct inode *, int);
 extern void nilfs_free_inode(struct inode *);
 extern int nilfs_get_block(struct inode *, sector_t, struct buffer_head *, int);