ocfs2: Introduce the new ocfs2_cluster_connect/disconnect() API.

This step introduces a cluster stack agnostic API for initializing and
exiting.  fs/ocfs2/dlmglue.c no longer uses o2cb/o2dlm knowledge to
connect to the stack.  It is all handled in stackglue.c.

heartbeat.c no longer needs to know how it gets called.
ocfs2_do_node_down() is now a clean recovery trigger.

The big gotcha is the ordering of initializations and de-initializations done
underneath ocfs2_cluster_connect().  ocfs2_dlm_init() used to do all
o2dlm initialization in one block.  Thus, the o2dlm functionality of
ocfs2_cluster_connect() is very straightforward.  ocfs2_dlm_shutdown(),
however, did a few things between de-registration of the eviction
callback and actually shutting down the domain.  Now de-registration and
shutdown of the domain are wrapped within the single
ocfs2_cluster_disconnect() call.  I've checked the code paths to make
sure we can safely tear down things in ocfs2_dlm_shutdown() before
calling ocfs2_cluster_disconnect().  The filesystem has already set
itself to ignore the callback.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

1 files changed, 33 insertions, 2 deletions

diff --git a/fs/ocfs2/stackglue.h b/fs/ocfs2/stackglue.h
index 3c91e241892b..3900b5c3933c 100644
--- a/fs/ocfs2/stackglue.h
+++ b/fs/ocfs2/stackglue.h
@@ -32,9 +32,22 @@
  */
 #define DLM_LKF_LOCAL           0x00100000
 
+/*
+ * This shadows DLM_LOCKSPACE_LEN in fs/dlm/dlm_internal.h.  That probably
+ * wants to be in a public header.
+ */
+#define GROUP_NAME_MAX          64
+
+
 #include "dlm/dlmapi.h"
 
+struct ocfs2_protocol_version {
+        u8 pv_major;
+        u8 pv_minor;
+};
+
 struct ocfs2_locking_protocol {
+        struct ocfs2_protocol_version lp_max_version;
         void (*lp_lock_ast)(void *astarg);
         void (*lp_blocking_ast)(void *astarg, int level);
         void (*lp_unlock_ast)(void *astarg, int error);
@@ -44,14 +57,32 @@ union ocfs2_dlm_lksb {
         struct dlm_lockstatus lksb_o2dlm;
 };
 
-int ocfs2_dlm_lock(struct dlm_ctxt *dlm,
+struct ocfs2_cluster_connection {
+        char cc_name[GROUP_NAME_MAX];
+        int cc_namelen;
+        struct ocfs2_protocol_version cc_version;
+        void (*cc_recovery_handler)(int node_num, void *recovery_data);
+        void *cc_recovery_data;
+        void *cc_lockspace;
+        void *cc_private;
+};
+
+int ocfs2_cluster_connect(const char *group,
+                          int grouplen,
+                          void (*recovery_handler)(int node_num,
+                                                   void *recovery_data),
+                          void *recovery_data,
+                          struct ocfs2_cluster_connection **conn);
+int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn);
+
+int ocfs2_dlm_lock(struct ocfs2_cluster_connection *conn,
                    int mode,
                    union ocfs2_dlm_lksb *lksb,
                    u32 flags,
                    void *name,
                    unsigned int namelen,
                    void *astarg);
-int ocfs2_dlm_unlock(struct dlm_ctxt *dlm,
+int ocfs2_dlm_unlock(struct ocfs2_cluster_connection *conn,
                      union ocfs2_dlm_lksb *lksb,
                      u32 flags,
                      void *astarg);