ocfs2: Break out stackglue into modules.
We define the ocfs2_stack_plugin structure to represent a stack driver.
The o2cb stack code is split into stack_o2cb.c. This becomes the
ocfs2_stack_o2cb.ko module.
The stackglue generic functions are similarly split into the
ocfs2_stackglue.ko module. This module now provides an interface to
register drivers. The ocfs2_stack_o2cb driver registers itself. As
part of this interface, ocfs2_stackglue can load drivers on demand.
This is accomplished in ocfs2_cluster_connect().
ocfs2_cluster_disconnect() is now notified when a _hangup() is pending.
If a hangup is pending, it will not release the driver module and will
let _hangup() do that.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
diff --git a/fs/ocfs2/stackglue.h b/fs/ocfs2/stackglue.h
index 0836322..c96c8bb 100644
--- a/fs/ocfs2/stackglue.h
+++ b/fs/ocfs2/stackglue.h
@@ -119,14 +119,21 @@
* Once ->disconnect() has returned, the connection structure will
* be freed. Thus, a stack must not return from ->disconnect()
* until it will no longer reference the conn pointer.
+ *
+ * If hangup_pending is zero, ocfs2_cluster_disconnect() will also
+ * be dropping the reference on the module.
*/
- int (*disconnect)(struct ocfs2_cluster_connection *conn);
+ int (*disconnect)(struct ocfs2_cluster_connection *conn,
+ int hangup_pending);
/*
* ocfs2_cluster_hangup() exists for compatibility with older
* ocfs2 tools. Only the classic stack really needs it. As such
* ->hangup() is not required of all stacks. See the comment by
* ocfs2_cluster_hangup() for more details.
+ *
+ * Note that ocfs2_cluster_hangup() can only be called if
+ * hangup_pending was passed to ocfs2_cluster_disconnect().
*/
void (*hangup)(const char *group, int grouplen);
@@ -184,13 +191,32 @@
void (*dump_lksb)(union ocfs2_dlm_lksb *lksb);
};
+/*
+ * Each stack plugin must describe itself by registering a
+ * ocfs2_stack_plugin structure. This is only seen by stackglue and the
+ * stack driver.
+ */
+struct ocfs2_stack_plugin {
+ char *sp_name;
+ struct ocfs2_stack_operations *sp_ops;
+ struct module *sp_owner;
+
+ /* These are managed by the stackglue code. */
+ struct list_head sp_list;
+ unsigned int sp_count;
+ struct ocfs2_locking_protocol *sp_proto;
+};
+
+
+/* Used by the filesystem */
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_cluster_disconnect(struct ocfs2_cluster_connection *conn,
+ int hangup_pending);
void ocfs2_cluster_hangup(const char *group, int grouplen);
int ocfs2_cluster_this_node(unsigned int *node);
@@ -212,6 +238,8 @@
void ocfs2_stack_glue_set_locking_protocol(struct ocfs2_locking_protocol *proto);
-extern struct ocfs2_locking_protocol *stack_glue_lproto;
-extern struct ocfs2_stack_operations o2cb_stack_ops;
+
+/* Used by stack plugins */
+int ocfs2_stack_glue_register(struct ocfs2_stack_plugin *plugin);
+void ocfs2_stack_glue_unregister(struct ocfs2_stack_plugin *plugin);
#endif /* STACKGLUE_H */