ocfs2: Take the inode out of the metadata read/write paths.

We are really passing the inode into the ocfs2_read/write_blocks()
functions to get at the metadata cache.  This commit passes the cache
directly into the metadata block functions, divorcing them from the
inode.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
diff --git a/fs/ocfs2/inode.h b/fs/ocfs2/inode.h
index cd1caca..b0a71b2 100644
--- a/fs/ocfs2/inode.h
+++ b/fs/ocfs2/inode.h
@@ -120,6 +120,11 @@
 extern const struct address_space_operations ocfs2_aops;
 extern const struct ocfs2_caching_operations ocfs2_inode_caching_ops;
 
+static inline struct ocfs2_caching_info *INODE_CACHE(struct inode *inode)
+{
+	return &OCFS2_I(inode)->ip_metadata_cache;
+}
+
 void ocfs2_clear_inode(struct inode *inode);
 void ocfs2_delete_inode(struct inode *inode);
 void ocfs2_drop_inode(struct inode *inode);