ocfs2: add clustername to cluster connection

This is an effort of removing ocfs2_controld.pcmk and getting ocfs2 DLM
handling up to the times with respect to DLM (>=4.0.1) and corosync
(2.3.x).  AFAIK, cman also is being phased out for a unified corosync
cluster stack.

fs/dlm performs all the functions with respect to fencing and node
management and provides the API's to do so for ocfs2.  For all future
references, DLM stands for fs/dlm code.

The advantages are:
 + No need to run an additional userspace daemon (ocfs2_controld)
 + No controld device handling and controld protocol
 + Shifting responsibilities of node management to DLM layer

For backward compatibility, we are keeping the controld handling code.
Once enough time has passed we can remove a significant portion of the
code.  This was tested by using the kernel with changes on older
unmodified tools.  The kernel used ocfs2_controld as expected, and
displayed the appropriate warning message.

This feature requires modification in the userspace ocfs2-tools.  The
changes can be found at: https://github.com/goldwynr/ocfs2-tools branch:
nocontrold Currently, not many checks are present in the userspace code,
but that would change soon.

This patch (of 6):

Add clustername to cluster connection.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ocfs2/stackglue.h b/fs/ocfs2/stackglue.h
index 1ec56fd..6d90f41 100644
--- a/fs/ocfs2/stackglue.h
+++ b/fs/ocfs2/stackglue.h
@@ -45,6 +45,9 @@
  */
 #define GROUP_NAME_MAX		64
 
+/* This shadows  OCFS2_CLUSTER_NAME_LEN */
+#define CLUSTER_NAME_MAX	16
+
 
 /*
  * ocfs2_protocol_version changes when ocfs2 does something different in
@@ -97,8 +100,10 @@
  * locking compatibility.
  */
 struct ocfs2_cluster_connection {
-	char cc_name[GROUP_NAME_MAX];
+	char cc_name[GROUP_NAME_MAX + 1];
 	int cc_namelen;
+	char cc_cluster_name[CLUSTER_NAME_MAX + 1];
+	int cc_cluster_name_len;
 	struct ocfs2_protocol_version cc_version;
 	struct ocfs2_locking_protocol *cc_proto;
 	void (*cc_recovery_handler)(int node_num, void *recovery_data);
@@ -239,6 +244,8 @@
 
 /* Used by the filesystem */
 int ocfs2_cluster_connect(const char *stack_name,
+			  const char *cluster_name,
+			  int cluster_name_len,
 			  const char *group,
 			  int grouplen,
 			  struct ocfs2_locking_protocol *lproto,