userdlm.h

linux 内核源代码

/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * userdlm.h
 *
 * Userspace dlm defines
 *
 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */


#ifndef USERDLM_H
#define USERDLM_H

#include <linux/module.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/workqueue.h>

/* user_lock_res->l_flags flags. */
#define USER_LOCK_ATTACHED      (0x00000001) /* have we initialized
					       * the lvb */
#define USER_LOCK_BUSY          (0x00000002) /* we are currently in
					       * dlm_lock */
#define USER_LOCK_BLOCKED       (0x00000004) /* blocked waiting to
					      * downconvert*/
#define USER_LOCK_IN_TEARDOWN   (0x00000008) /* we're currently
					      * destroying this
					      * lock. */
#define USER_LOCK_QUEUED        (0x00000010) /* lock is on the
					      * workqueue */
#define USER_LOCK_IN_CANCEL     (0x00000020)

struct user_lock_res {
	spinlock_t               l_lock;

	int                      l_flags;

#define USER_DLM_LOCK_ID_MAX_LEN  32
	char                     l_name[USER_DLM_LOCK_ID_MAX_LEN];
	int                      l_namelen;
	int                      l_level;
	unsigned int             l_ro_holders;
	unsigned int             l_ex_holders;
	struct dlm_lockstatus    l_lksb;

	int                      l_requested;
	int                      l_blocking;

	wait_queue_head_t        l_event;

	struct work_struct       l_work;
};

extern struct workqueue_struct *user_dlm_worker;

void user_dlm_lock_res_init(struct user_lock_res *lockres,
			    struct dentry *dentry);
int user_dlm_destroy_lock(struct user_lock_res *lockres);
int user_dlm_cluster_lock(struct user_lock_res *lockres,
			  int level,
			  int lkm_flags);
void user_dlm_cluster_unlock(struct user_lock_res *lockres,
			     int level);
void user_dlm_write_lvb(struct inode *inode,
			const char *val,
			unsigned int len);
void user_dlm_read_lvb(struct inode *inode,
		       char *val,
		       unsigned int len);
struct dlm_ctxt *user_dlm_register_context(struct qstr *name);
void user_dlm_unregister_context(struct dlm_ctxt *dlm);

struct dlmfs_inode_private {
	struct dlm_ctxt             *ip_dlm;

	struct user_lock_res ip_lockres; /* unused for directories. */
	struct inode         *ip_parent;

	struct inode         ip_vfs_inode;
};

static inline struct dlmfs_inode_private *
DLMFS_I(struct inode *inode)
{
        return container_of(inode,
			    struct dlmfs_inode_private,
			    ip_vfs_inode);
}

struct dlmfs_filp_private {
	int                  fp_lock_level;
};

#define DLMFS_MAGIC	0x76a9f425

#endif /* USERDLM_H */