path: root/fs/ocfs2/dlm/dlmcommon.h

/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * dlmcommon.h
 *
 * Copyright (C) 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 DLMCOMMON_H
#define DLMCOMMON_H

#include <linux/kref.h>

#define DLM_HB_NODE_DOWN_PRI     (0xf000000)
#define DLM_HB_NODE_UP_PRI       (0x8000000)

#define DLM_LOCKID_NAME_MAX    32

#define DLM_DOMAIN_NAME_MAX_LEN    255
#define DLM_LOCK_RES_OWNER_UNKNOWN     O2NM_MAX_NODES
#define DLM_THREAD_SHUFFLE_INTERVAL    5     // flush everything every 5 passes
#define DLM_THREAD_MS                  200   // flush at least every 200 ms

#define DLM_HASH_SIZE_DEFAULT	(1 << 14)
#if DLM_HASH_SIZE_DEFAULT < PAGE_SIZE
# define DLM_HASH_PAGES		1
#else
# define DLM_HASH_PAGES		(DLM_HASH_SIZE_DEFAULT / PAGE_SIZE)
#endif
#define DLM_BUCKETS_PER_PAGE	(PAGE_SIZE / sizeof(struct hlist_head))
#define DLM_HASH_BUCKETS	(DLM_HASH_PAGES * DLM_BUCKETS_PER_PAGE)

/* Intended to make it easier for us to switch out hash functions */
#define dlm_lockid_hash(_n, _l) full_name_hash(_n, _l)

enum dlm_ast_type {
	DLM_AST = 0,
	DLM_BAST,
	DLM_ASTUNLOCK
};


#define LKM_VALID_FLAGS (LKM_VALBLK | LKM_CONVERT | LKM_UNLOCK | \
			 LKM_CANCEL | LKM_INVVALBLK | LKM_FORCE | \
			 LKM_RECOVERY | LKM_LOCAL | LKM_NOQUEUE)

#define DLM_RECOVERY_LOCK_NAME       "$RECOVERY"
#define DLM_RECOVERY_LOCK_NAME_LEN   9

static inline int dlm_is_recovery_lock(const char *lock_name, int name_len)
{
	if (name_len == DLM_RECOVERY_LOCK_NAME_LEN &&
	    memcmp(lock_name, DLM_RECOVERY_LOCK_NAME, name_len)==0)
		return 1;
	return 0;
}

#define DLM_RECO_STATE_ACTIVE    0x0001
#define DLM_RECO_STATE_FINALIZE  0x0002

struct dlm_recovery_ctxt
{
	struct list_head resources;
	struct list_head received;
	struct list_head node_data;
	u8  new_master;
	u8  dead_node;
	u16 state;
	unsigned long node_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
	wait_queue_head_t event;
};

enum dlm_ctxt_state {
	DLM_CTXT_NEW = 0,
	DLM_CTXT_JOINED,
	DLM_CTXT_IN_SHUTDOWN,
	DLM_CTXT_LEAVING,
};

struct dlm_ctxt
{
	struct list_head list;
	struct hlist_head **lockres_hash;
	struct list_head dirty_list;
	struct list_head purge_list;
	struct list_head pending_asts;
	struct list_head pending_basts;
	unsigned int purge_count;
	spinlock_t spinlock;
	spinlock_t ast_lock;
	char *name;
	u8 node_num;
	u32 key;
	u8  joining_node;
	wait_queue_head_t dlm_join_events;
	unsigned long live_nodes_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
	unsigned long domain_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
	unsigned long recovery_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
	struct dlm_recovery_ctxt reco;
	spinlock_t master_lock;
	struct list_head master_list;
	struct list_head mle_hb_events;

	/* these give a really vague idea of the system load */
	atomic_t local_resources;
	atomic_t remote_resources;
	atomic_t unknown_resources;

	/* NOTE: Next three are protected by dlm_domain_lock */
	struct kref dlm_refs;
	enum dlm_ctxt_state dlm_state;
	unsigned int num_joins;

	struct o2hb_callback_func dlm_hb_up;
	struct o2hb_callback_func dlm_hb_down;
	struct task_struct *dlm_thread_task;
	struct task_struct *dlm_reco_thread_task;
	struct workqueue_struct *dlm_worker;
	wait_queue_head_t dlm_thread_wq;
	wait_queue_head_t dlm_reco_thread_wq;
	wait_queue_head_t ast_wq;
	wait_queue_head_t migration_wq;

	struct work_struct dispatched_work;
	struct list_head work_list;
	spinlock_t work_lock;
	struct list_head dlm_domain_handlers;
	struct list_head	dlm_eviction_callbacks;

	/* The filesystem specifies this at domain registration.  We
	 * cache it here to know what to tell other nodes. */
	struct dlm_protocol_version fs_locking_proto;
	/* This is the inter-dlm communication version */
	struct dlm_protocol_version dlm_locking_proto;
};

static inline struct hlist_head *dlm_lockres_hash(struct dlm_ctxt *dlm, unsigned i)
{
	return dlm->lockres_hash[(i / DLM_BUCKETS_PER_PAGE) % DLM_HASH_PAGES] + (i % DLM_BUCKETS_PER_PAGE);
}

/* these keventd work queue items are for less-frequently
 * called functions that cannot be directly called from the
 * net message handlers for some reason, usually because
 * they need to send net messages of their own. */
void dlm_dispatch_work(struct work_struct *work);

struct dlm_lock_resource;
struct dlm_work_item;

typedef void (dlm_workfunc_t)(struct dlm_work_item *, void *);

struct dlm_request_all_locks_priv
{
	u8 reco_master;
	u8 dead_node;
};

struct dlm_mig_lockres_priv
{
	struct dlm_lock_resource *lockres;
	u8 real_master;
};

struct dlm_assert_master_priv
{
	struct dlm_lock_resource *lockres;
	u8 request_from;
	u32 flags;
	unsigned ignore_higher:1;
};

struct dlm_deref_lockres_priv
{