ocfs2: Fix up i_blocks calculation to know about holes

Older file systems which didn't support holes did a dumb calculation of
i_blocks based on i_size. This is no longer accurate, so fix things up to
take actual allocation into account.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/inode.h b/fs/ocfs2/inode.h
index a9ced00..aa84353 100644
--- a/fs/ocfs2/inode.h
+++ b/fs/ocfs2/inode.h
@@ -138,4 +138,11 @@
 
 void ocfs2_set_inode_flags(struct inode *inode);
 
+static inline blkcnt_t ocfs2_inode_sector_count(struct inode *inode)
+{
+	int c_to_s_bits = OCFS2_SB(inode->i_sb)->s_clustersize_bits - 9;
+
+	return (blkcnt_t)(OCFS2_I(inode)->ip_clusters << c_to_s_bits);
+}
+
 #endif /* OCFS2_INODE_H */