linux/fs/ocfs2/stackglue.h

/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * stackglue.h
 *
 * Glue to the underlying cluster stack.
 *
 * Copyright (C) 2007 Oracle.  All rights reserved.
 */


#ifndef STACKGLUE_H
#define STACKGLUE_H

#include <linux/types.h>
#include <linux/list.h>
#include <linux/dlmconstants.h>

#include "dlm/dlmapi.h"
#include <linux/dlm.h>

/* Needed for plock-related prototypes */
struct file;
struct file_lock;

/*
 * 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
 * than any flag in dlmconstants.h.
 */
#define DLM_LKF_LOCAL …

/*
 * This shadows DLM_LOCKSPACE_LEN in fs/dlm/dlm_internal.h.  That probably
 * wants to be in a public header.
 */
#define GROUP_NAME_MAX …

/* This shadows  OCFS2_CLUSTER_NAME_LEN */
#define CLUSTER_NAME_MAX …


/*
 * ocfs2_protocol_version changes when ocfs2 does something different in
 * its inter-node behavior.  See dlmglue.c for more information.
 */
struct ocfs2_protocol_version { … };

/*
 * The dlm_lockstatus struct includes lvb space, but the dlm_lksb struct only
 * has a pointer to separately allocated lvb space.  This struct exists only to
 * include in the lksb union to make space for a combined dlm_lksb and lvb.
 */
struct fsdlm_lksb_plus_lvb { … };

/*
 * 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.
 */
struct ocfs2_cluster_connection;
struct ocfs2_dlm_lksb { … };

/*
 * The ocfs2_locking_protocol defines the handlers called on ocfs2's behalf.
 */
struct ocfs2_locking_protocol { … };


/*
 * 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 { … };

/*
 * 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 { … };

/*
 * 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 { … };


/* 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,
			  void (*recovery_handler)(int node_num,
						   void *recovery_data),
			  void *recovery_data,
			  struct ocfs2_cluster_connection **conn);
/*
 * Used by callers that don't store their stack name.  They must ensure
 * all nodes have the same stack.
 */
int ocfs2_cluster_connect_agnostic(const char *group,
				   int grouplen,
				   struct ocfs2_locking_protocol *lproto,
				   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 hangup_pending);
void ocfs2_cluster_hangup(const char *group, int grouplen);
int ocfs2_cluster_this_node(struct ocfs2_cluster_connection *conn,
			    unsigned int *node);

struct ocfs2_lock_res;
int ocfs2_dlm_lock(struct ocfs2_cluster_connection *conn,
		   int mode,
		   struct ocfs2_dlm_lksb *lksb,
		   u32 flags,
		   void *name,
		   unsigned int namelen);
int ocfs2_dlm_unlock(struct ocfs2_cluster_connection *conn,
		     struct ocfs2_dlm_lksb *lksb,
		     u32 flags);

int ocfs2_dlm_lock_status(struct ocfs2_dlm_lksb *lksb);
int ocfs2_dlm_lvb_valid(struct ocfs2_dlm_lksb *lksb);
void *ocfs2_dlm_lvb(struct ocfs2_dlm_lksb *lksb);
void ocfs2_dlm_dump_lksb(struct ocfs2_dlm_lksb *lksb);

int ocfs2_stack_supports_plocks(void);
int ocfs2_plock(struct ocfs2_cluster_connection *conn, u64 ino,
		struct file *file, int cmd, struct file_lock *fl);

void ocfs2_stack_glue_set_max_proto_version(struct ocfs2_protocol_version *max_proto);


/* Used by stack plugins */
int ocfs2_stack_glue_register(struct ocfs2_stack_plugin *plugin);
void ocfs2_stack_glue_unregister(struct ocfs2_stack_plugin *plugin);

extern struct kset *ocfs2_kset;

#endif  /* STACKGLUE_H */