ocfs2/dlm: Create slabcaches for lock and lockres

[linux-2.6/linux-2.6-openrd.git] / 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;
        u8 extra_ref;
};

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

struct dlm_deref_lockres_priv
{
        struct dlm_lock_resource *deref_res;
        u8 deref_node;
};

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;
                struct dlm_deref_lockres_priv dl;
        } 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_LOCK_RES_DROPPING_REF         0x00000040
#define DLM_LOCK_RES_BLOCK_DIRTY          0x00001000
#define DLM_LOCK_RES_SETREF_INPROG        0x00002000

/* max milliseconds to wait to sync up a network failure with a node death */
#define DLM_NODE_DEATH_WAIT_MAX (5 * 1000)

#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 hlist_node hash_node;
        struct qstr lockname;
        struct kref      refs;

        /*
         * Please keep granted, converting, and blocked in this order,
         * as some funcs want to iterate over all lists.
         *
         * All four lists are protected by the hash's reference.
         */
        struct list_head granted;
        struct list_head converting;
        struct list_head blocked;
        struct list_head purge;

        /*
         * These two lists require you to hold an additional reference
         * while they are on the list.
         */
        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. */
        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;
        char lvb[DLM_LVB_LEN];
        unsigned int inflight_locks;
        unsigned long refmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
};

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 int dlm_lvb_is_empty(char *lvb)
{
        int i;
        for (i=0; i<DLM_LVB_LEN; i++)
                if (lvb[i])
                        return 0;
        return 1;
}

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_DEREF_LOCKRES_MSG,   /* 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_RESPONSE_REASSERT       0x00000001
#define DLM_ASSERT_RESPONSE_MASTERY_REF    0x00000002

#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];
};

#define DLM_MIGRATE_RESPONSE_MASTERY_REF   0x00000001

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_code {
        JOIN_DISALLOW = 0,
        JOIN_OK,
        JOIN_OK_NO_MAP,
        JOIN_PROTOCOL_MISMATCH,
};

struct dlm_query_join_packet {
        u8 code;        /* Response code.  dlm_minor and fs_minor
                           are only valid if this is JOIN_OK */
        u8 dlm_minor;   /* The minor version of the protocol the
                           dlm is speaking. */
        u8 fs_minor;    /* The minor version of the protocol the
                           filesystem is speaking. */
        u8 reserved;
};

union dlm_query_join_response {
        u32 intval;
        struct dlm_query_join_packet packet;
};

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;
};


#define BITS_PER_BYTE 8
#define BITS_TO_BYTES(bits) (((bits)+BITS_PER_BYTE-1)/BITS_PER_BYTE)

struct dlm_query_join_request
{
        u8 node_idx;
        u8 pad1[2];
        u8 name_len;
        struct dlm_protocol_version dlm_proto;
        struct dlm_protocol_version fs_proto;
        u8 domain[O2NM_MAX_NAME_LEN];
        u8 node_map[BITS_TO_BYTES(O2NM_MAX_NODES)];
};

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;
        u8 flags;
        u8 pad1;
        __be32 pad2;
};

struct dlm_deref_lockres
{
        u32 pad1;
        u16 pad2;
        u8 node_idx;
        u8 namelen;

        u8 name[O2NM_MAX_NAME_LEN];
};

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;
}

static inline u8 dlm_get_lock_cookie_node(u64 cookie)
{
        u8 ret;
        cookie >>= 56;
        ret = (u8)(cookie & 0xffULL);
        return ret;
}

static inline unsigned long long dlm_get_lock_cookie_seq(u64 cookie)
{
        unsigned long long ret;
        ret = ((unsigned long long)cookie) & 0x00ffffffffffffffULL;
        return ret;
}

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,
                            void **ret_data);
int dlm_convert_lock_handler(struct o2net_msg *msg, u32 len, void *data,
                             void **ret_data);
int dlm_proxy_ast_handler(struct o2net_msg *msg, u32 len, void *data,
                          void **ret_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 **ret_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_kick_recovery_thread(struct dlm_ctxt *dlm);
int dlm_is_node_dead(struct dlm_ctxt *dlm, u8 node);
int dlm_wait_for_node_death(struct dlm_ctxt *dlm, u8 node, int timeout);
int dlm_wait_for_node_recovery(struct dlm_ctxt *dlm, u8 node, int timeout);

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);
static inline void dlm_lockres_get(struct dlm_lock_resource *res)
{
        /* This is called on every lookup, so it might be worth
         * inlining. */
        kref_get(&res->refs);
}
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_full(struct dlm_ctxt *dlm,
                                                     const char *name,
                                                     unsigned int len,
                                                     unsigned int hash);
struct dlm_lock_resource * __dlm_lookup_lockres(struct dlm_ctxt *dlm,
                                                const char *name,
                                                unsigned int len,
                                                unsigned int hash);
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 namelen,
                                                 int flags);
struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm,
                                          const char *name,
                                          unsigned int namelen);

#define dlm_lockres_set_refmap_bit(bit,res)  \
        __dlm_lockres_set_refmap_bit(bit,res,__FILE__,__LINE__)
#define dlm_lockres_clear_refmap_bit(bit,res)  \
        __dlm_lockres_clear_refmap_bit(bit,res,__FILE__,__LINE__)

static inline void __dlm_lockres_set_refmap_bit(int bit,
                                                struct dlm_lock_resource *res,
                                                const char *file,
                                                int line)
{
        //printk("%s:%d:%.*s: setting bit %d\n", file, line,
        //     res->lockname.len, res->lockname.name, bit);
        set_bit(bit, res->refmap);
}

static inline void __dlm_lockres_clear_refmap_bit(int bit,
                                                  struct dlm_lock_resource *res,
                                                  const char *file,
                                                  int line)
{
        //printk("%s:%d:%.*s: clearing bit %d\n", file, line,
        //     res->lockname.len, res->lockname.name, bit);
        clear_bit(bit, res->refmap);
}

void __dlm_lockres_drop_inflight_ref(struct dlm_ctxt *dlm,
                                   struct dlm_lock_resource *res,
                                   const char *file,
                                   int line);
void __dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm,
                                   struct dlm_lock_resource *res,
                                   int new_lockres,
                                   const char *file,
                                   int line);
#define dlm_lockres_drop_inflight_ref(d,r)  \
        __dlm_lockres_drop_inflight_ref(d,r,__FILE__,__LINE__)
#define dlm_lockres_grab_inflight_ref(d,r)  \
        __dlm_lockres_grab_inflight_ref(d,r,0,__FILE__,__LINE__)
#define dlm_lockres_grab_inflight_ref_new(d,r)  \
        __dlm_lockres_grab_inflight_ref(d,r,1,__FILE__,__LINE__)

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_empty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res);
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,
                               void **ret_data);
int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data,
                              void **ret_data);
void dlm_assert_master_post_handler(int status, void *data, void *ret_data);
int dlm_deref_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
                              void **ret_data);
int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data,
                                void **ret_data);
int dlm_mig_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
                            void **ret_data);
int dlm_master_requery_handler(struct o2net_msg *msg, u32 len, void *data,
                               void **ret_data);
int dlm_request_all_locks_handler(struct o2net_msg *msg, u32 len, void *data,
                                  void **ret_data);
int dlm_reco_data_done_handler(struct o2net_msg *msg, u32 len, void *data,
                               void **ret_data);
int dlm_begin_reco_handler(struct o2net_msg *msg, u32 len, void *data,
                           void **ret_data);
int dlm_finalize_reco_handler(struct o2net_msg *msg, u32 len, void *data,
                              void **ret_data);
int dlm_do_master_requery(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
                          u8 nodenum, u8 *real_master);


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));
}

/* create/destroy slab caches */
int dlm_init_master_caches(void);
void dlm_destroy_master_caches(void);

int dlm_init_lock_cache(void);
void dlm_destroy_lock_cache(void);

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);
int dlm_drop_lockres_ref(struct dlm_ctxt *dlm,
                         struct dlm_lock_resource *res);
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);
int __dlm_lockres_has_locks(struct dlm_lock_resource *res);
int __dlm_lockres_unused(struct dlm_lock_resource *res);

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 */