[PATCH] OCFS2: The Second Oracle Cluster Filesystem

A distributed lock manager built with the cluster file system use case
in mind. The OCFS2 dlm exposes a VMS style API, though things have
been simplified internally. The only lock levels implemented currently
are NLMODE, PRMODE and EXMODE.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com>

1 files changed, 884 insertions, 0 deletions

diff --git a/fs/ocfs2/dlm/dlmcommon.h b/fs/ocfs2/dlm/dlmcommon.h
new file mode 100644
index 00000000000..3fecba0a602
--- /dev/null
+++ b/fs/ocfs2/dlm/dlmcommon.h
@@ -0,0 +1,884 @@
+/* -*- 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_BITS     7
+#define DLM_HASH_SIZE     (1 << DLM_HASH_BITS)
+#define DLM_HASH_MASK     (DLM_HASH_SIZE - 1)
+
+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
+
+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 list_head *resources;
+	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;
+	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;
+};
+
+/* 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(void *data);
+
+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_work_item
+{
+	struct list_head list;
+	dlm_workfunc_t *func;
+	struct dlm_ctxt *dlm;
+	void *data;
+	union {
+		struct dlm_request_all_locks_priv ral;
+		struct dlm_mig_lockres_priv ml;
+		struct dlm_assert_master_priv am;
+	} u;
+};
+
+static inline void dlm_init_work_item(struct dlm_ctxt *dlm,
+				      struct dlm_work_item *i,
+				      dlm_workfunc_t *f, void *data)
+{
+	memset(i, 0, sizeof(*i));
+	i->func = f;
+	INIT_LIST_HEAD(&i->list);
+	i->data = data;
+	i->dlm = dlm;  /* must have already done a dlm_grab on this! */
+}
+
+
+
+static inline void __dlm_set_joining_node(struct dlm_ctxt *dlm,
+					  u8 node)
+{
+	assert_spin_locked(&dlm->spinlock);
+
+	dlm->joining_node = node;
+	wake_up(&dlm->dlm_join_events);
+}
+
+#define DLM_LOCK_RES_UNINITED             0x00000001
+#define DLM_LOCK_RES_RECOVERING           0x00000002
+#define DLM_LOCK_RES_READY                0x00000004
+#define DLM_LOCK_RES_DIRTY                0x00000008
+#define DLM_LOCK_RES_IN_PROGRESS          0x00000010
+#define DLM_LOCK_RES_MIGRATING            0x00000020
+
+#define DLM_PURGE_INTERVAL_MS   (8 * 1000)
+
+struct dlm_lock_resource
+{
+	/* WARNING: Please see the comment in dlm_init_lockres before
+	 * adding fields here. */
+	struct list_head list;
+	struct kref      refs;
+
+	/* please keep these next 3 in this order
+	 * some funcs want to iterate over all lists */
+	struct list_head granted;
+	struct list_head converting;
+	struct list_head blocked;
+
+	struct list_head dirty;
+	struct list_head recovering; // dlm_recovery_ctxt.resources list
+
+	/* unused lock resources have their last_used stamped and are
+	 * put on a list for the dlm thread to run. */
+	struct list_head purge;
+	unsigned long    last_used;
+
+	unsigned migration_pending:1;
+	atomic_t asts_reserved;
+	spinlock_t spinlock;
+	wait_queue_head_t wq;
+	u8  owner;              //node which owns the lock resource, or unknown
+	u16 state;
+	struct qstr lockname;
+	char lvb[DLM_LVB_LEN];
+};
+
+struct dlm_migratable_lock
+{
+	__be64 cookie;
+
+	/* these 3 are just padding for the in-memory structure, but
+	 * list and flags are actually used when sent over the wire */
+	__be16 pad1;
+	u8 list;  // 0=granted, 1=converting, 2=blocked
+	u8 flags;
+
+	s8 type;
+	s8 convert_type;
+	s8 highest_blocked;
+	u8 node;
+};  // 16 bytes
+
+struct dlm_lock
+{
+	struct dlm_migratable_lock ml;
+
+	struct list_head list;
+	struct list_head ast_list;
+	struct list_head bast_list;
+	struct dlm_lock_resource *lockres;
+	spinlock_t spinlock;
+	struct kref lock_refs;
+
+	// ast and bast must be callable while holding a spinlock!
+	dlm_astlockfunc_t *ast;
+	dlm_bastlockfunc_t *bast;
+	void *astdata;
+	struct dlm_lockstatus *lksb;
+	unsigned ast_pending:1,
+		 bast_pending:1,
+		 convert_pending:1,
+		 lock_pending:1,
+		 cancel_pending:1,
+		 unlock_pending:1,
+		 lksb_kernel_allocated:1;
+};
+
+
+#define DLM_LKSB_UNUSED1           0x01
+#define DLM_LKSB_PUT_LVB           0x02
+#define DLM_LKSB_GET_LVB           0x04
+#define DLM_LKSB_UNUSED2           0x08
+#define DLM_LKSB_UNUSED3           0x10
+#define DLM_LKSB_UNUSED4           0x20
+#define DLM_LKSB_UNUSED5           0x40
+#define DLM_LKSB_UNUSED6           0x80
+
+
+enum dlm_lockres_list {
+	DLM_GRANTED_LIST = 0,
+	DLM_CONVERTING_LIST,
+	DLM_BLOCKED_LIST
+};
+
+static inline struct list_head *
+dlm_list_idx_to_ptr(struct dlm_lock_resource *res, enum dlm_lockres_list idx)
+{
+	struct list_head *ret = NULL;
+	if (idx == DLM_GRANTED_LIST)
+		ret = &res->granted;
+	else if (idx == DLM_CONVERTING_LIST)
+		ret = &res->converting;
+	else if (idx == DLM_BLOCKED_LIST)
+		ret = &res->blocked;
+	else
+		BUG();
+	return ret;
+}
+
+
+
+
+struct dlm_node_iter
+{
+	unsigned long node_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
+	int curnode;
+};
+
+
+enum {
+	DLM_MASTER_REQUEST_MSG    = 500,
+	DLM_UNUSED_MSG1,         /* 501 */
+	DLM_ASSERT_MASTER_MSG,	 /* 502 */
+	DLM_CREATE_LOCK_MSG,	 /* 503 */
+	DLM_CONVERT_LOCK_MSG,	 /* 504 */
+	DLM_PROXY_AST_MSG,	 /* 505 */
+	DLM_UNLOCK_LOCK_MSG,	 /* 506 */
+	DLM_UNUSED_MSG2,	 /* 507 */
+	DLM_MIGRATE_REQUEST_MSG, /* 508 */
+	DLM_MIG_LOCKRES_MSG, 	 /* 509 */
+	DLM_QUERY_JOIN_MSG,	 /* 510 */
+	DLM_ASSERT_JOINED_MSG,	 /* 511 */
+	DLM_CANCEL_JOIN_MSG,	 /* 512 */
+	DLM_EXIT_DOMAIN_MSG,	 /* 513 */
+	DLM_MASTER_REQUERY_MSG,	 /* 514 */
+	DLM_LOCK_REQUEST_MSG,	 /* 515 */
+	DLM_RECO_DATA_DONE_MSG,	 /* 516 */
+	DLM_BEGIN_RECO_MSG,	 /* 517 */
+	DLM_FINALIZE_RECO_MSG	 /* 518 */
+};
+
+struct dlm_reco_node_data
+{
+	int state;
+	u8 node_num;
+	struct list_head list;
+};
+
+enum {
+	DLM_RECO_NODE_DATA_DEAD = -1,
+	DLM_RECO_NODE_DATA_INIT = 0,
+	DLM_RECO_NODE_DATA_REQUESTING,
+	DLM_RECO_NODE_DATA_REQUESTED,
+	DLM_RECO_NODE_DATA_RECEIVING,
+	DLM_RECO_NODE_DATA_DONE,
+	DLM_RECO_NODE_DATA_FINALIZE_SENT,
+};
+
+
+enum {
+	DLM_MASTER_RESP_NO = 0,
+	DLM_MASTER_RESP_YES,
+	DLM_MASTER_RESP_MAYBE,
+	DLM_MASTER_RESP_ERROR
+};
+
+
+struct dlm_master_request
+{
+	u8 node_idx;
+	u8 namelen;
+	__be16 pad1;
+	__be32 flags;
+
+	u8 name[O2NM_MAX_NAME_LEN];
+};
+
+#define DLM_ASSERT_MASTER_MLE_CLEANUP      0x00000001
+#define DLM_ASSERT_MASTER_REQUERY          0x00000002
+#define DLM_ASSERT_MASTER_FINISH_MIGRATION 0x00000004
+struct dlm_assert_master
+{
+	u8 node_idx;
+	u8 namelen;
+	__be16 pad1;
+	__be32 flags;
+
+	u8 name[O2NM_MAX_NAME_LEN];
+};
+
+struct dlm_migrate_request
+{
+	u8 master;
+	u8 new_master;
+	u8 namelen;
+	u8 pad1;
+	__be32 pad2;
+	u8 name[O2NM_MAX_NAME_LEN];
+};
+
+struct dlm_master_requery
+{
+	u8 pad1;
+	u8 pad2;
+	u8 node_idx;
+	u8 namelen;
+	__be32 pad3;
+	u8 name[O2NM_MAX_NAME_LEN];
+};
+
+#define DLM_MRES_RECOVERY   0x01
+#define DLM_MRES_MIGRATION  0x02
+#define DLM_MRES_ALL_DONE   0x04
+
+/*
+ * We would like to get one whole lockres into a single network
+ * message whenever possible.  Generally speaking, there will be
+ * at most one dlm_lock on a lockres for each node in the cluster,
+ * plus (infrequently) any additional locks coming in from userdlm.
+ *
+ * struct _dlm_lockres_page
+ * {
+ * 	dlm_migratable_lockres mres;
+ * 	dlm_migratable_lock ml[DLM_MAX_MIGRATABLE_LOCKS];
+ * 	u8 pad[DLM_MIG_LOCKRES_RESERVED];
+ * };
+ *
+ * from ../cluster/tcp.h
+ *    NET_MAX_PAYLOAD_BYTES  (4096 - sizeof(net_msg))
+ *    (roughly 4080 bytes)
+ * and sizeof(dlm_migratable_lockres) = 112 bytes
+ * and sizeof(dlm_migratable_lock) = 16 bytes
+ *
+ * Choosing DLM_MAX_MIGRATABLE_LOCKS=240 and
+ * DLM_MIG_LOCKRES_RESERVED=128 means we have this:
+ *
+ *  (DLM_MAX_MIGRATABLE_LOCKS * sizeof(dlm_migratable_lock)) +
+ *     sizeof(dlm_migratable_lockres) + DLM_MIG_LOCKRES_RESERVED =
+ *        NET_MAX_PAYLOAD_BYTES
+ *  (240 * 16) + 112 + 128 = 4080
+ *
+ * So a lockres would need more than 240 locks before it would
+ * use more than one network packet to recover.  Not too bad.
+ */
+#define DLM_MAX_MIGRATABLE_LOCKS   240
+
+struct dlm_migratable_lockres
+{
+	u8 master;
+	u8 lockname_len;
+	u8 num_locks;    // locks sent in this structure
+	u8 flags;
+	__be32 total_locks; // locks to be sent for this migration cookie
+	__be64 mig_cookie;  // cookie for this lockres migration
+			 // or zero if not needed
+	// 16 bytes
+	u8 lockname[DLM_LOCKID_NAME_MAX];
+	// 48 bytes
+	u8 lvb[DLM_LVB_LEN];
+	// 112 bytes
+	struct dlm_migratable_lock ml[0];  // 16 bytes each, begins at byte 112
+};
+#define DLM_MIG_LOCKRES_MAX_LEN  \
+	(sizeof(struct dlm_migratable_lockres) + \
+	 (sizeof(struct dlm_migratable_lock) * \
+	  DLM_MAX_MIGRATABLE_LOCKS) )
+
+/* from above, 128 bytes
+ * for some undetermined future use */
+#define DLM_MIG_LOCKRES_RESERVED   (NET_MAX_PAYLOAD_BYTES - \
+				    DLM_MIG_LOCKRES_MAX_LEN)
+
+struct dlm_create_lock
+{
+	__be64 cookie;
+
+	__be32 flags;
+	u8 pad1;
+	u8 node_idx;
+	s8 requested_type;
+	u8 namelen;
+
+	u8 name[O2NM_MAX_NAME_LEN];
+};
+
+struct dlm_convert_lock
+{
+	__be64 cookie;
+
+	__be32 flags;
+	u8 pad1;
+	u8 node_idx;
+	s8 requested_type;
+	u8 namelen;
+
+	u8 name[O2NM_MAX_NAME_LEN];
+
+	s8 lvb[0];
+};
+#define DLM_CONVERT_LOCK_MAX_LEN  (sizeof(struct dlm_convert_lock)+DLM_LVB_LEN)
+
+struct dlm_unlock_lock
+{
+	__be64 cookie;
+
+	__be32 flags;
+	__be16 pad1;
+	u8 node_idx;
+	u8 namelen;
+
+	u8 name[O2NM_MAX_NAME_LEN];
+
+	s8 lvb[0];
+};
+#define DLM_UNLOCK_LOCK_MAX_LEN  (sizeof(struct dlm_unlock_lock)+DLM_LVB_LEN)
+
+struct dlm_proxy_ast
+{
+	__be64 cookie;
+
+	__be32 flags;
+	u8 node_idx;
+	u8 type;
+	u8 blocked_type;
+	u8 namelen;
+
+	u8 name[O2NM_MAX_NAME_LEN];
+
+	s8 lvb[0];
+};
+#define DLM_PROXY_AST_MAX_LEN  (sizeof(struct dlm_proxy_ast)+DLM_LVB_LEN)
+
+#define DLM_MOD_KEY (0x666c6172)
+enum dlm_query_join_response {
+	JOIN_DISALLOW = 0,
+	JOIN_OK,
+	JOIN_OK_NO_MAP,
+};
+
+struct dlm_lock_request
+{
+	u8 node_idx;
+	u8 dead_node;
+	__be16 pad1;
+	__be32 pad2;
+};
+
+struct dlm_reco_data_done
+{
+	u8 node_idx;
+	u8 dead_node;
+	__be16 pad1;
+	__be32 pad2;
+
+	/* unused for now */
+	/* eventually we can use this to attempt
+	 * lvb recovery based on each node's info */
+	u8 reco_lvb[DLM_LVB_LEN];
+};
+
+struct dlm_begin_reco
+{
+	u8 node_idx;
+	u8 dead_node;
+	__be16 pad1;
+	__be32 pad2;
+};
+
+
+struct dlm_query_join_request
+{
+	u8 node_idx;
+	u8 pad1[2];
+	u8 name_len;
+	u8 domain[O2NM_MAX_NAME_LEN];
+};
+
+struct dlm_assert_joined
+{
+	u8 node_idx;
+	u8 pad1[2];
+	u8 name_len;
+	u8 domain[O2NM_MAX_NAME_LEN];
+};
+
+struct dlm_cancel_join
+{
+	u8 node_idx;
+	u8 pad1[2];
+	u8 name_len;
+	u8 domain[O2NM_MAX_NAME_LEN];
+};
+
+struct dlm_exit_domain
+{
+	u8 node_idx;
+	u8 pad1[3];
+};
+
+struct dlm_finalize_reco
+{
+	u8 node_idx;
+	u8 dead_node;
+	__be16 pad1;
+	__be32 pad2;
+};
+
+static inline enum dlm_status
+__dlm_lockres_state_to_status(struct dlm_lock_resource *res)
+{
+	enum dlm_status status = DLM_NORMAL;
+
+	assert_spin_locked(&res->spinlock);
+
+	if (res->state & DLM_LOCK_RES_RECOVERING)
+		status = DLM_RECOVERING;
+	else if (res->state & DLM_LOCK_RES_MIGRATING)
+		status = DLM_MIGRATING;
+	else if (res->state & DLM_LOCK_RES_IN_PROGRESS)
+		status = DLM_FORWARD;
+
+	return status;
+}
+
+struct dlm_lock * dlm_new_lock(int type, u8 node, u64 cookie,
+			       struct dlm_lockstatus *lksb);
+void dlm_lock_get(struct dlm_lock *lock);
+void dlm_lock_put(struct dlm_lock *lock);
+
+void dlm_lock_attach_lockres(struct dlm_lock *lock,
+			     struct dlm_lock_resource *res);
+
+int dlm_create_lock_handler(struct o2net_msg *msg, u32 len, void *data);
+int dlm_convert_lock_handler(struct o2net_msg *msg, u32 len, void *data);
+int dlm_proxy_ast_handler(struct o2net_msg *msg, u32 len, void *data);
+
+void dlm_revert_pending_convert(struct dlm_lock_resource *res,
+				struct dlm_lock *lock);
+void dlm_revert_pending_lock(struct dlm_lock_resource *res,
+			     struct dlm_lock *lock);
+
+int dlm_unlock_lock_handler(struct o2net_msg *msg, u32 len, void *data);
+void dlm_commit_pending_cancel(struct dlm_lock_resource *res,
+			       struct dlm_lock *lock);
+void dlm_commit_pending_unlock(struct dlm_lock_resource *res,
+			       struct dlm_lock *lock);
+
+int dlm_launch_thread(struct dlm_ctxt *dlm);
+void dlm_complete_thread(struct dlm_ctxt *dlm);
+int dlm_launch_recovery_thread(struct dlm_ctxt *dlm);
+void dlm_complete_recovery_thread(struct dlm_ctxt *dlm);
+void dlm_wait_for_recovery(struct dlm_ctxt *dlm);
+
+void dlm_put(struct dlm_ctxt *dlm);
+struct dlm_ctxt *dlm_grab(struct dlm_ctxt *dlm);
+int dlm_domain_fully_joined(struct dlm_ctxt *dlm);
+
+void __dlm_lockres_calc_usage(struct dlm_ctxt *dlm,
+			      struct dlm_lock_resource *res);
+void dlm_lockres_calc_usage(struct dlm_ctxt *dlm,
+			    struct dlm_lock_resource *res);
+void dlm_purge_lockres(struct dlm_ctxt *dlm,
+		       struct dlm_lock_resource *lockres);
+void dlm_lockres_get(struct dlm_lock_resource *res);
+void dlm_lockres_put(struct dlm_lock_resource *res);
+void __dlm_unhash_lockres(struct dlm_lock_resource *res);
+void __dlm_insert_lockres(struct dlm_ctxt *dlm,
+			  struct dlm_lock_resource *res);
+struct dlm_lock_resource * __dlm_lookup_lockres(struct dlm_ctxt *dlm,
+						const char *name,
+						unsigned int len);
+struct dlm_lock_resource * dlm_lookup_lockres(struct dlm_ctxt *dlm,
+					      const char *name,
+					      unsigned int len);
+
+int dlm_is_host_down(int errno);
+void dlm_change_lockres_owner(struct dlm_ctxt *dlm,
+			      struct dlm_lock_resource *res,
+			      u8 owner);
+struct dlm_lock_resource * dlm_get_lock_resource(struct dlm_ctxt *dlm,
+						 const char *lockid,
+						 int flags);
+struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm,
+					  const char *name,
+					  unsigned int namelen);
+
+void dlm_queue_ast(struct dlm_ctxt *dlm, struct dlm_lock *lock);
+void dlm_queue_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock);
+void dlm_do_local_ast(struct dlm_ctxt *dlm,
+		      struct dlm_lock_resource *res,
+		      struct dlm_lock *lock);
+int dlm_do_remote_ast(struct dlm_ctxt *dlm,
+		      struct dlm_lock_resource *res,
+		      struct dlm_lock *lock);
+void dlm_do_local_bast(struct dlm_ctxt *dlm,
+		       struct dlm_lock_resource *res,
+		       struct dlm_lock *lock,
+		       int blocked_type);
+int dlm_send_proxy_ast_msg(struct dlm_ctxt *dlm,
+			   struct dlm_lock_resource *res,
+			   struct dlm_lock *lock,
+			   int msg_type,
+			   int blocked_type, int flags);
+static inline int dlm_send_proxy_bast(struct dlm_ctxt *dlm,
+				      struct dlm_lock_resource *res,
+				      struct dlm_lock *lock,
+				      int blocked_type)
+{
+	return dlm_send_proxy_ast_msg(dlm, res, lock, DLM_BAST,
+				      blocked_type, 0);
+}
+
+static inline int dlm_send_proxy_ast(struct dlm_ctxt *dlm,
+				     struct dlm_lock_resource *res,
+				     struct dlm_lock *lock,
+				     int flags)
+{
+	return dlm_send_proxy_ast_msg(dlm, res, lock, DLM_AST,
+				      0, flags);
+}
+
+void dlm_print_one_lock_resource(struct dlm_lock_resource *res);
+void __dlm_print_one_lock_resource(struct dlm_lock_resource *res);
+
+u8 dlm_nm_this_node(struct dlm_ctxt *dlm);
+void dlm_kick_thread(struct dlm_ctxt *dlm, struct dlm_lock_resource *res);
+void __dlm_dirty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res);
+
+
+int dlm_nm_init(struct dlm_ctxt *dlm);
+int dlm_heartbeat_init(struct dlm_ctxt *dlm);
+void dlm_hb_node_down_cb(struct o2nm_node *node, int idx, void *data);
+void dlm_hb_node_up_cb(struct o2nm_node *node, int idx, void *data);
+
+int dlm_lockres_is_dirty(struct dlm_ctxt *dlm, struct dlm_lock_resource *res);
+int dlm_migrate_lockres(struct dlm_ctxt *dlm,
+			struct dlm_lock_resource *res,
+			u8 target);
+int dlm_finish_migration(struct dlm_ctxt *dlm,
+			 struct dlm_lock_resource *res,
+			 u8 old_master);
+void dlm_lockres_release_ast(struct dlm_ctxt *dlm,
+			     struct dlm_lock_resource *res);
+void __dlm_lockres_reserve_ast(struct dlm_lock_resource *res);
+
+int dlm_master_request_handler(struct o2net_msg *msg, u32 len, void *data);
+int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data);
+int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data);
+int dlm_mig_lockres_handler(struct o2net_msg *msg, u32 len, void *data);
+int dlm_master_requery_handler(struct o2net_msg *msg, u32 len, void *data);
+int dlm_request_all_locks_handler(struct o2net_msg *msg, u32 len, void *data);
+int dlm_reco_data_done_handler(struct o2net_msg *msg, u32 len, void *data);
+int dlm_begin_reco_handler(struct o2net_msg *msg, u32 len, void *data);
+int dlm_finalize_reco_handler(struct o2net_msg *msg, u32 len, void *data);
+
+int dlm_dispatch_assert_master(struct dlm_ctxt *dlm,
+			       struct dlm_lock_resource *res,
+			       int ignore_higher,
+			       u8 request_from,
+			       u32 flags);
+
+
+int dlm_send_one_lockres(struct dlm_ctxt *dlm,
+			 struct dlm_lock_resource *res,
+			 struct dlm_migratable_lockres *mres,
+			 u8 send_to,
+			 u8 flags);
+void dlm_move_lockres_to_recovery_list(struct dlm_ctxt *dlm,
+				       struct dlm_lock_resource *res);
+
+/* will exit holding res->spinlock, but may drop in function */
+void __dlm_wait_on_lockres_flags(struct dlm_lock_resource *res, int flags);
+void __dlm_wait_on_lockres_flags_set(struct dlm_lock_resource *res, int flags);
+
+/* will exit holding res->spinlock, but may drop in function */
+static inline void __dlm_wait_on_lockres(struct dlm_lock_resource *res)
+{
+	__dlm_wait_on_lockres_flags(res, (DLM_LOCK_RES_IN_PROGRESS|
+				    	  DLM_LOCK_RES_RECOVERING|
+					  DLM_LOCK_RES_MIGRATING));
+}
+
+
+int dlm_init_mle_cache(void);
+void dlm_destroy_mle_cache(void);
+void dlm_hb_event_notify_attached(struct dlm_ctxt *dlm, int idx, int node_up);
+void dlm_clean_master_list(struct dlm_ctxt *dlm,
+			   u8 dead_node);
+int dlm_lock_basts_flushed(struct dlm_ctxt *dlm, struct dlm_lock *lock);
+
+
+static inline const char * dlm_lock_mode_name(int mode)
+{
+	switch (mode) {
+		case LKM_EXMODE:
+			return "EX";
+		case LKM_PRMODE:
+			return "PR";
+		case LKM_NLMODE:
+			return "NL";
+	}
+	return "UNKNOWN";
+}
+
+
+static inline int dlm_lock_compatible(int existing, int request)
+{
+	/* NO_LOCK compatible with all */
+	if (request == LKM_NLMODE ||
+	    existing == LKM_NLMODE)
+		return 1;
+
+	/* EX incompatible with all non-NO_LOCK */
+	if (request == LKM_EXMODE)
+		return 0;
+
+	/* request must be PR, which is compatible with PR */
+	if (existing == LKM_PRMODE)
+		return 1;
+
+	return 0;
+}
+
+static inline int dlm_lock_on_list(struct list_head *head,
+				   struct dlm_lock *lock)
+{
+	struct list_head *iter;
+	struct dlm_lock *tmplock;
+
+	list_for_each(iter, head) {
+		tmplock = list_entry(iter, struct dlm_lock, list);
+		if (tmplock == lock)
+			return 1;
+	}
+	return 0;
+}
+
+
+static inline enum dlm_status dlm_err_to_dlm_status(int err)
+{
+	enum dlm_status ret;
+	if (err == -ENOMEM)
+		ret = DLM_SYSERR;
+	else if (err == -ETIMEDOUT || o2net_link_down(err, NULL))
+		ret = DLM_NOLOCKMGR;
+	else if (err == -EINVAL)
+		ret = DLM_BADPARAM;
+	else if (err == -ENAMETOOLONG)
+		ret = DLM_IVBUFLEN;
+	else
+		ret = DLM_BADARGS;
+	return ret;
+}
+
+
+static inline void dlm_node_iter_init(unsigned long *map,
+				      struct dlm_node_iter *iter)
+{
+	memcpy(iter->node_map, map, sizeof(iter->node_map));
+	iter->curnode = -1;
+}
+
+static inline int dlm_node_iter_next(struct dlm_node_iter *iter)
+{
+	int bit;
+	bit = find_next_bit(iter->node_map, O2NM_MAX_NODES, iter->curnode+1);
+	if (bit >= O2NM_MAX_NODES) {
+		iter->curnode = O2NM_MAX_NODES;
+		return -ENOENT;
+	}
+	iter->curnode = bit;
+	return bit;
+}
+
+
+
+#endif /* DLMCOMMON_H */