ocfs2: Create ocfs2_stack_operations and split out the o2cb stack.
Define the ocfs2_stack_operations structure. Build o2cb_stack_ops from
all of the o2cb-specific stack functions. Change the generic stack glue
functions to call the stack_ops instead of the o2cb functions directly.
The o2cb functions are moved to stack_o2cb.c. The headers are cleaned up
to where only needed headers are included.
In this code, stackglue.c and stack_o2cb.c refer to some shared
extern variables. When they become modules, that will change.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
diff --git a/fs/ocfs2/stackglue.h b/fs/ocfs2/stackglue.h
index decb147..0836322 100644
--- a/fs/ocfs2/stackglue.h
+++ b/fs/ocfs2/stackglue.h
@@ -25,6 +25,8 @@
#include <linux/list.h>
#include <linux/dlmconstants.h>
+#include "dlm/dlmapi.h"
+
/*
* dlmconstants.h does not have a LOCAL flag. We hope to remove it
* some day, but right now we need it. Let's fake it. This value is larger
@@ -39,13 +41,18 @@
#define GROUP_NAME_MAX 64
-#include "dlm/dlmapi.h"
-
+/*
+ * ocfs2_protocol_version changes when ocfs2 does something different in
+ * its inter-node behavior. See dlmglue.c for more information.
+ */
struct ocfs2_protocol_version {
u8 pv_major;
u8 pv_minor;
};
+/*
+ * The ocfs2_locking_protocol defines the handlers called on ocfs2's behalf.
+ */
struct ocfs2_locking_protocol {
struct ocfs2_protocol_version lp_max_version;
void (*lp_lock_ast)(void *astarg);
@@ -53,10 +60,20 @@
void (*lp_unlock_ast)(void *astarg, int error);
};
+/*
+ * A union of all lock status structures. We define it here so that the
+ * size of the union is known. Lock status structures are embedded in
+ * ocfs2 inodes.
+ */
union ocfs2_dlm_lksb {
struct dlm_lockstatus lksb_o2dlm;
};
+/*
+ * A cluster connection. Mostly opaque to ocfs2, the connection holds
+ * state for the underlying stack. ocfs2 does use cc_version to determine
+ * locking compatibility.
+ */
struct ocfs2_cluster_connection {
char cc_name[GROUP_NAME_MAX];
int cc_namelen;
@@ -67,6 +84,106 @@
void *cc_private;
};
+/*
+ * Each cluster stack implements the stack operations structure. Not used
+ * in the ocfs2 code, the stackglue code translates generic cluster calls
+ * into stack operations.
+ */
+struct ocfs2_stack_operations {
+ /*
+ * The fs code calls ocfs2_cluster_connect() to attach a new
+ * filesystem to the cluster stack. The ->connect() op is passed
+ * an ocfs2_cluster_connection with the name and recovery field
+ * filled in.
+ *
+ * The stack must set up any notification mechanisms and create
+ * the filesystem lockspace in the DLM. The lockspace should be
+ * stored on cc_lockspace. Any other information can be stored on
+ * cc_private.
+ *
+ * ->connect() must not return until it is guaranteed that
+ *
+ * - Node down notifications for the filesystem will be recieved
+ * and passed to conn->cc_recovery_handler().
+ * - Locking requests for the filesystem will be processed.
+ */
+ int (*connect)(struct ocfs2_cluster_connection *conn);
+
+ /*
+ * The fs code calls ocfs2_cluster_disconnect() when a filesystem
+ * no longer needs cluster services. All DLM locks have been
+ * dropped, and recovery notification is being ignored by the
+ * fs code. The stack must disengage from the DLM and discontinue
+ * recovery notification.
+ *
+ * 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.
+ */
+ int (*disconnect)(struct ocfs2_cluster_connection *conn);
+
+ /*
+ * 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.
+ */
+ void (*hangup)(const char *group, int grouplen);
+
+ /*
+ * ->this_node() returns the cluster's unique identifier for the
+ * local node.
+ */
+ int (*this_node)(unsigned int *node);
+
+ /*
+ * Call the underlying dlm lock function. The ->dlm_lock()
+ * callback should convert the flags and mode as appropriate.
+ *
+ * ast and bast functions are not part of the call because the
+ * stack will likely want to wrap ast and bast calls before passing
+ * them to stack->sp_proto.
+ */
+ int (*dlm_lock)(struct ocfs2_cluster_connection *conn,
+ int mode,
+ union ocfs2_dlm_lksb *lksb,
+ u32 flags,
+ void *name,
+ unsigned int namelen,
+ void *astarg);
+
+ /*
+ * Call the underlying dlm unlock function. The ->dlm_unlock()
+ * function should convert the flags as appropriate.
+ *
+ * The unlock ast is not passed, as the stack will want to wrap
+ * it before calling stack->sp_proto->lp_unlock_ast().
+ */
+ int (*dlm_unlock)(struct ocfs2_cluster_connection *conn,
+ union ocfs2_dlm_lksb *lksb,
+ u32 flags,
+ void *astarg);
+
+ /*
+ * Return the status of the current lock status block. The fs
+ * code should never dereference the union. The ->lock_status()
+ * callback pulls out the stack-specific lksb, converts the status
+ * to a proper errno, and returns it.
+ */
+ int (*lock_status)(union ocfs2_dlm_lksb *lksb);
+
+ /*
+ * Pull the lvb pointer off of the stack-specific lksb.
+ */
+ void *(*lock_lvb)(union ocfs2_dlm_lksb *lksb);
+
+ /*
+ * This is an optoinal debugging hook. If provided, the
+ * stack can dump debugging information about this lock.
+ */
+ void (*dump_lksb)(union ocfs2_dlm_lksb *lksb);
+};
+
int ocfs2_cluster_connect(const char *group,
int grouplen,
void (*recovery_handler)(int node_num,
@@ -95,4 +212,6 @@
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;
#endif /* STACKGLUE_H */