ocfs2_dlmfs: Use the stackglue.

Rather than directly using o2dlm, dlmfs can now use the stackglue.  This
allows it to use userspace cluster stacks and fs/dlm.  This commit
forces o2cb for now.  A latter commit will bump the protocol version and
allow non-o2cb stacks.

This is one big sed, really.  LKM_xxMODE becomes DLM_LOCK_xx.  LKM_flag
becomes DLM_LKF_flag.

We also learn to check that the LVB is valid before reading it.  Any DLM
can lose the contents of the LVB during a complicated recovery.  userdlm
should be checking this.  Now it does.  dlmfs will return 0 from read(2)
if the LVB was invalid.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
diff --git a/fs/ocfs2/dlmfs/userdlm.h b/fs/ocfs2/dlmfs/userdlm.h
index 0c3cc03..3b42d79 100644
--- a/fs/ocfs2/dlmfs/userdlm.h
+++ b/fs/ocfs2/dlmfs/userdlm.h
@@ -57,7 +57,7 @@
 	int                      l_level;
 	unsigned int             l_ro_holders;
 	unsigned int             l_ex_holders;
-	struct dlm_lockstatus    l_lksb;
+	struct ocfs2_dlm_lksb    l_lksb;
 
 	int                      l_requested;
 	int                      l_blocking;
@@ -80,15 +80,15 @@
 void user_dlm_write_lvb(struct inode *inode,
 			const char *val,
 			unsigned int len);
-void user_dlm_read_lvb(struct inode *inode,
-		       char *val,
-		       unsigned int len);
-struct dlm_ctxt *user_dlm_register_context(struct qstr *name,
-					   struct dlm_protocol_version *proto);
-void user_dlm_unregister_context(struct dlm_ctxt *dlm);
+ssize_t user_dlm_read_lvb(struct inode *inode,
+			  char *val,
+			  unsigned int len);
+struct ocfs2_cluster_connection *user_dlm_register(struct qstr *name);
+void user_dlm_unregister(struct ocfs2_cluster_connection *conn);
+void user_dlm_set_locking_protocol(void);
 
 struct dlmfs_inode_private {
-	struct dlm_ctxt             *ip_dlm;
+	struct ocfs2_cluster_connection	*ip_conn;
 
 	struct user_lock_res ip_lockres; /* unused for directories. */
 	struct inode         *ip_parent;