/******************************************************************************
*******************************************************************************
**
**  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
**  Copyright (C) 2004-2011 Red Hat, Inc.  All rights reserved.
**
**  This copyrighted material is made available to anyone wishing to use,
**  modify, copy, or redistribute it subject to the terms and conditions
**  of the GNU General Public License v.2.
**
*******************************************************************************
******************************************************************************/

#ifndef __DLM_INTERNAL_DOT_H__
#define __DLM_INTERNAL_DOT_H__

/*
 * This is the main header file to be included in each DLM source file.
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/ctype.h>
#include <linux/spinlock.h>
#include <linux/vmalloc.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/random.h>
#include <linux/delay.h>
#include <linux/socket.h>
#include <linux/kthread.h>
#include <linux/kobject.h>
#include <linux/kref.h>
#include <linux/kernel.h>
#include <linux/jhash.h>
#include <linux/miscdevice.h>
#include <linux/mutex.h>
#include <linux/idr.h>
#include <linux/ratelimit.h>
#include <asm/uaccess.h>

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

/* Size of the temp buffer midcomms allocates on the stack.
   We try to make this large enough so most messages fit.
   FIXME: should sctp make this unnecessary? */

#define DLM_INBUF_LEN           148

struct dlm_ls;
struct dlm_lkb;
struct dlm_rsb;
struct dlm_member;
struct dlm_rsbtable;
struct dlm_recover;
struct dlm_header;
struct dlm_message;
struct dlm_rcom;
struct dlm_mhandle;

#define log_print(fmt, args...) \
        printk(KERN_ERR "dlm: "fmt"\n" , ##args)
#define log_error(ls, fmt, args...) \
        printk(KERN_ERR "dlm: %s: " fmt "\n", (ls)->ls_name , ##args)

#define log_debug(ls, fmt, args...) \
do { \
        if (dlm_config.ci_log_debug) \
                printk(KERN_DEBUG "dlm: %s: " fmt "\n", \
                       (ls)->ls_name , ##args); \
} while (0)

#define log_limit(ls, fmt, args...) \
do { \
        if (dlm_config.ci_log_debug) \
                printk_ratelimited(KERN_DEBUG "dlm: %s: " fmt "\n", \
                        (ls)->ls_name , ##args); \
} while (0)

#define DLM_ASSERT(x, do) \
{ \
  if (!(x)) \
  { \
    printk(KERN_ERR "\nDLM:  Assertion failed on line %d of file %s\n" \
               "DLM:  assertion:  \"%s\"\n" \
               "DLM:  time = %lu\n", \
               __LINE__, __FILE__, #x, jiffies); \
    {do} \
    printk("\n"); \
    BUG(); \
    panic("DLM:  Record message above and reboot.\n"); \
  } \
}


struct dlm_rsbtable {
        struct rb_root          keep;
        struct rb_root          toss;
        spinlock_t              lock;
};


/*
 * Lockspace member (per node in a ls)
 */

struct dlm_member {
        struct list_head        list;
        int                     nodeid;
        int                     weight;
        int                     slot;
        int                     slot_prev;
        int                     comm_seq;
        uint32_t                generation;
};

/*
 * Save and manage recovery state for a lockspace.
 */

struct dlm_recover {
        struct list_head        list;
        struct dlm_config_node  *nodes;
        int                     nodes_count;
        uint64_t                seq;
};

/*
 * Pass input args to second stage locking function.
 */

struct dlm_args {
        uint32_t                flags;
        void                    (*astfn) (void *astparam);
        void                    *astparam;
        void                    (*bastfn) (void *astparam, int mode);
        int                     mode;
        struct dlm_lksb         *lksb;
        unsigned long           timeout;
};


/*
 * Lock block
 *
 * A lock can be one of three types:
 *
 * local copy      lock is mastered locally
 *                 (lkb_nodeid is zero and DLM_LKF_MSTCPY is not set)
 * process copy    lock is mastered on a remote node
 *                 (lkb_nodeid is non-zero and DLM_LKF_MSTCPY is not set)
 * master copy     master node's copy of a lock owned by remote node
 *                 (lkb_nodeid is non-zero and DLM_LKF_MSTCPY is set)
 *
 * lkb_exflags: a copy of the most recent flags arg provided to dlm_lock or
 * dlm_unlock.  The dlm does not modify these or use any private flags in
 * this field; it only contains DLM_LKF_ flags from dlm.h.  These flags
 * are sent as-is to the remote master when the lock is remote.
 *
 * lkb_flags: internal dlm flags (DLM_IFL_ prefix) from dlm_internal.h.
 * Some internal flags are shared between the master and process nodes;
 * these shared flags are kept in the lower two bytes.  One of these
 * flags set on the master copy will be propagated to the process copy
 * and v.v.  Other internal flags are private to the master or process
 * node (e.g. DLM_IFL_MSTCPY).  These are kept in the high two bytes.
 *
 * lkb_sbflags: status block flags.  These flags are copied directly into
 * the caller's lksb.sb_flags prior to the dlm_lock/dlm_unlock completion
 * ast.  All defined in dlm.h with DLM_SBF_ prefix.
 *
 * lkb_status: the lock status indicates which rsb queue the lock is
 * on, grant, convert, or wait.  DLM_LKSTS_ WAITING/GRANTED/CONVERT
 *
 * lkb_wait_type: the dlm message type (DLM_MSG_ prefix) for which a
 * reply is needed.  Only set when the lkb is on the lockspace waiters
 * list awaiting a reply from a remote node.
 *
 * lkb_nodeid: when the lkb is a local copy, nodeid is 0; when the lkb
 * is a master copy, nodeid specifies the remote lock holder, when the
 * lkb is a process copy, the nodeid specifies the lock master.
 */

/* lkb_status */

#define DLM_LKSTS_WAITING       1
#define DLM_LKSTS_GRANTED       2
#define DLM_LKSTS_CONVERT       3

/* lkb_flags */

#define DLM_IFL_MSTCPY          0x00010000
#define DLM_IFL_RESEND          0x00020000
#define DLM_IFL_DEAD            0x00040000
#define DLM_IFL_OVERLAP_UNLOCK  0x00080000
#define DLM_IFL_OVERLAP_CANCEL  0x00100000
#define DLM_IFL_ENDOFLIFE       0x00200000
#define DLM_IFL_WATCH_TIMEWARN  0x00400000
#define DLM_IFL_TIMEOUT_CANCEL  0x00800000
#define DLM_IFL_DEADLOCK_CANCEL 0x01000000
#define DLM_IFL_STUB_MS         0x02000000 /* magic number for m_flags */
#define DLM_IFL_USER            0x00000001
#define DLM_IFL_ORPHAN          0x00000002

#define DLM_CALLBACKS_SIZE      6

#define DLM_CB_CAST             0x00000001
#define DLM_CB_BAST             0x00000002
#define DLM_CB_SKIP             0x00000004

struct dlm_callback {
        uint64_t                seq;
        uint32_t                flags;          /* DLM_CBF_ */
        int                     sb_status;      /* copy to lksb status */
        uint8_t                 sb_flags;       /* copy to lksb flags */
        int8_t                  mode; /* rq mode of bast, gr mode of cast */
};

struct dlm_lkb {
        struct dlm_rsb          *lkb_resource;  /* the rsb */
        struct kref             lkb_ref;
        int                     lkb_nodeid;     /* copied from rsb */
        int                     lkb_ownpid;     /* pid of lock owner */
        uint32_t                lkb_id;         /* our lock ID */
        uint32_t                lkb_remid;      /* lock ID on remote partner */
        uint32_t                lkb_exflags;    /* external flags from caller */
        uint32_t                lkb_sbflags;    /* lksb flags */
        uint32_t                lkb_flags;      /* internal flags */
        uint32_t                lkb_lvbseq;     /* lvb sequence number */

        int8_t                  lkb_status;     /* granted, waiting, convert */
        int8_t                  lkb_rqmode;     /* requested lock mode */
        int8_t                  lkb_grmode;     /* granted lock mode */
        int8_t                  lkb_highbast;   /* highest mode bast sent for */

        int8_t                  lkb_wait_type;  /* type of reply waiting for */
        int8_t                  lkb_wait_count;
        int                     lkb_wait_nodeid; /* for debugging */

        struct list_head        lkb_statequeue; /* rsb g/c/w list */
        struct list_head        lkb_rsb_lookup; /* waiting for rsb lookup */
        struct list_head        lkb_wait_reply; /* waiting for remote reply */
        struct list_head        lkb_ownqueue;   /* list of locks for a process */
        struct list_head        lkb_time_list;
        ktime_t                 lkb_timestamp;
        ktime_t                 lkb_wait_time;
        unsigned long           lkb_timeout_cs;

        struct mutex            lkb_cb_mutex;
        struct work_struct      lkb_cb_work;
        struct list_head        lkb_cb_list; /* for ls_cb_delay or proc->asts */
        struct dlm_callback     lkb_callbacks[DLM_CALLBACKS_SIZE];
        struct dlm_callback     lkb_last_cast;
        struct dlm_callback     lkb_last_bast;
        ktime_t                 lkb_last_cast_time;     /* for debugging */
        ktime_t                 lkb_last_bast_time;     /* for debugging */

        uint64_t                lkb_recover_seq; /* from ls_recover_seq */

        char                    *lkb_lvbptr;
        struct dlm_lksb         *lkb_lksb;      /* caller's status block */
        void                    (*lkb_astfn) (void *astparam);
        void                    (*lkb_bastfn) (void *astparam, int mode);
        union {
                void                    *lkb_astparam;  /* caller's ast arg */
                struct dlm_user_args    *lkb_ua;
        };
};

/*
 * res_master_nodeid is "normal": 0 is unset/invalid, non-zero is the real
 * nodeid, even when nodeid is our_nodeid.
 *
 * res_nodeid is "odd": -1 is unset/invalid, zero means our_nodeid,
 * greater than zero when another nodeid.
 *
 * (TODO: remove res_nodeid and only use res_master_nodeid)
 */

struct dlm_rsb {
        struct dlm_ls           *res_ls;        /* the lockspace */
        struct kref             res_ref;
        struct mutex            res_mutex;
        unsigned long           res_flags;
        int                     res_length;     /* length of rsb name */
        int                     res_nodeid;
        int                     res_master_nodeid;
        int                     res_dir_nodeid;
        int                     res_id;         /* for ls_recover_idr */
        uint32_t                res_lvbseq;
        uint32_t                res_hash;
        uint32_t                res_bucket;     /* rsbtbl */
        unsigned long           res_toss_time;
        uint32_t                res_first_lkid;
        struct list_head        res_lookup;     /* lkbs waiting on first */
        union {
                struct list_head        res_hashchain;
                struct rb_node          res_hashnode;   /* rsbtbl */
        };
        struct list_head        res_grantqueue;
        struct list_head        res_convertqueue;
        struct list_head        res_waitqueue;

        struct list_head        res_root_list;      /* used for recovery */
        struct list_head        res_recover_list;   /* used for recovery */
        int                     res_recover_locks_count;

        char                    *res_lvbptr;
        char                    res_name[DLM_RESNAME_MAXLEN+1];
};

/* dlm_master_lookup() flags */

#define DLM_LU_RECOVER_DIR      1
#define DLM_LU_RECOVER_MASTER   2

/* dlm_master_lookup() results */

#define DLM_LU_MATCH            1
#define DLM_LU_ADD              2

/* find_rsb() flags */

#define R_REQUEST               0x00000001
#define R_RECEIVE_REQUEST       0x00000002
#define R_RECEIVE_RECOVER       0x00000004

/* rsb_flags */

enum rsb_flags {
        RSB_MASTER_UNCERTAIN,
        RSB_VALNOTVALID,
        RSB_VALNOTVALID_PREV,
        RSB_NEW_MASTER,
        RSB_NEW_MASTER2,
        RSB_RECOVER_CONVERT,
        RSB_RECOVER_GRANT,
};

static inline void rsb_set_flag(struct dlm_rsb *r, enum rsb_flags flag)
{
        __set_bit(flag, &r->res_flags);
}

static inline void rsb_clear_flag(struct dlm_rsb *r, enum rsb_flags flag)
{
        __clear_bit(flag, &r->res_flags);
}

static inline int rsb_flag(struct dlm_rsb *r, enum rsb_flags flag)
{
        return test_bit(flag, &r->res_flags);
}


/* dlm_header is first element of all structs sent between nodes */

#define DLM_HEADER_MAJOR        0x00030000
#define DLM_HEADER_MINOR        0x00000001

#define DLM_HEADER_SLOTS        0x00000001

#define DLM_MSG                 1
#define DLM_RCOM                2

struct dlm_header {
        uint32_t                h_version;
        uint32_t                h_lockspace;
        uint32_t                h_nodeid;       /* nodeid of sender */
        uint16_t                h_length;
        uint8_t                 h_cmd;          /* DLM_MSG, DLM_RCOM */
        uint8_t                 h_pad;
};


#define DLM_MSG_REQUEST         1
#define DLM_MSG_CONVERT         2
#define DLM_MSG_UNLOCK          3
#define DLM_MSG_CANCEL          4
#define DLM_MSG_REQUEST_REPLY   5
#define DLM_MSG_CONVERT_REPLY   6
#define DLM_MSG_UNLOCK_REPLY    7
#define DLM_MSG_CANCEL_REPLY    8
#define DLM_MSG_GRANT           9
#define DLM_MSG_BAST            10
#define DLM_MSG_LOOKUP          11
#define DLM_MSG_REMOVE          12
#define DLM_MSG_LOOKUP_REPLY    13
#define DLM_MSG_PURGE           14

struct dlm_message {
        struct dlm_header       m_header;
        uint32_t                m_type;         /* DLM_MSG_ */
        uint32_t                m_nodeid;
        uint32_t                m_pid;
        uint32_t                m_lkid;         /* lkid on sender */
        uint32_t                m_remid;        /* lkid on receiver */
        uint32_t                m_parent_lkid;
        uint32_t                m_parent_remid;
        uint32_t                m_exflags;
        uint32_t                m_sbflags;
        uint32_t                m_flags;
        uint32_t                m_lvbseq;
        uint32_t                m_hash;
        int                     m_status;
        int                     m_grmode;
        int                     m_rqmode;
        int                     m_bastmode;
        int                     m_asts;
        int                     m_result;       /* 0 or -EXXX */
        char                    m_extra[0];     /* name or lvb */
};


#define DLM_RS_NODES            0x00000001
#define DLM_RS_NODES_ALL        0x00000002
#define DLM_RS_DIR              0x00000004
#define DLM_RS_DIR_ALL          0x00000008
#define DLM_RS_LOCKS            0x00000010
#define DLM_RS_LOCKS_ALL        0x00000020
#define DLM_RS_DONE             0x00000040
#define DLM_RS_DONE_ALL         0x00000080

#define DLM_RCOM_STATUS         1
#define DLM_RCOM_NAMES          2
#define DLM_RCOM_LOOKUP         3
#define DLM_RCOM_LOCK           4
#define DLM_RCOM_STATUS_REPLY   5
#define DLM_RCOM_NAMES_REPLY    6
#define DLM_RCOM_LOOKUP_REPLY   7
#define DLM_RCOM_LOCK_REPLY     8

struct dlm_rcom {
        struct dlm_header       rc_header;
        uint32_t                rc_type;        /* DLM_RCOM_ */
        int                     rc_result;      /* multi-purpose */
        uint64_t                rc_id;          /* match reply with request */
        uint64_t                rc_seq;         /* sender's ls_recover_seq */
        uint64_t                rc_seq_reply;   /* remote ls_recover_seq */
        char                    rc_buf[0];
};

union dlm_packet {
        struct dlm_header       header;         /* common to other two */
        struct dlm_message      message;
        struct dlm_rcom         rcom;
};

#define DLM_RSF_NEED_SLOTS      0x00000001

/* RCOM_STATUS data */
struct rcom_status {
        __le32                  rs_flags;
        __le32                  rs_unused1;
        __le64                  rs_unused2;
};

/* RCOM_STATUS_REPLY data */
struct rcom_config {
        __le32                  rf_lvblen;
        __le32                  rf_lsflags;

        /* DLM_HEADER_SLOTS adds: */
        __le32                  rf_flags;
        __le16                  rf_our_slot;
        __le16                  rf_num_slots;
        __le32                  rf_generation;
        __le32                  rf_unused1;
        __le64                  rf_unused2;
};

struct rcom_slot {
        __le32                  ro_nodeid;
        __le16                  ro_slot;
        __le16                  ro_unused1;
        __le64                  ro_unused2;
};

struct rcom_lock {
        __le32                  rl_ownpid;
        __le32                  rl_lkid;
        __le32                  rl_remid;
        __le32                  rl_parent_lkid;
        __le32                  rl_parent_remid;
        __le32                  rl_exflags;
        __le32                  rl_flags;
        __le32                  rl_lvbseq;
        __le32                  rl_result;
        int8_t                  rl_rqmode;
        int8_t                  rl_grmode;
        int8_t                  rl_status;
        int8_t                  rl_asts;
        __le16                  rl_wait_type;
        __le16                  rl_namelen;
        char                    rl_name[DLM_RESNAME_MAXLEN];
        char                    rl_lvb[0];
};

/*
 * The max number of resources per rsbtbl bucket that shrink will attempt
 * to remove in each iteration.
 */

#define DLM_REMOVE_NAMES_MAX 8

struct dlm_ls {
        struct list_head        ls_list;        /* list of lockspaces */
        dlm_lockspace_t         *ls_local_handle;
        uint32_t                ls_global_id;   /* global unique lockspace ID */
        uint32_t                ls_generation;
        uint32_t                ls_exflags;
        int                     ls_lvblen;
        int                     ls_count;       /* refcount of processes in
                                                   the dlm using this ls */
        int                     ls_create_count; /* create/release refcount */
        unsigned long           ls_flags;       /* LSFL_ */
        unsigned long           ls_scan_time;
        struct kobject          ls_kobj;

        struct idr              ls_lkbidr;
        spinlock_t              ls_lkbidr_spin;

        struct dlm_rsbtable     *ls_rsbtbl;
        uint32_t                ls_rsbtbl_size;

        struct mutex            ls_waiters_mutex;
        struct list_head        ls_waiters;     /* lkbs needing a reply */

        struct mutex            ls_orphans_mutex;
        struct list_head        ls_orphans;

        struct mutex            ls_timeout_mutex;
        struct list_head        ls_timeout;

        spinlock_t              ls_new_rsb_spin;
        int                     ls_new_rsb_count;
        struct list_head        ls_new_rsb;     /* new rsb structs */

        spinlock_t              ls_remove_spin;
        char                    ls_remove_name[DLM_RESNAME_MAXLEN+1];
        char                    *ls_remove_names[DLM_REMOVE_NAMES_MAX];
        int                     ls_remove_len;
        int                     ls_remove_lens[DLM_REMOVE_NAMES_MAX];

        struct list_head        ls_nodes;       /* current nodes in ls */
        struct list_head        ls_nodes_gone;  /* dead node list, recovery */
        int                     ls_num_nodes;   /* number of nodes in ls */
        int                     ls_low_nodeid;
        int                     ls_total_weight;
        int                     *ls_node_array;

        int                     ls_slot;
        int                     ls_num_slots;
        int                     ls_slots_size;
        struct dlm_slot         *ls_slots;

        struct dlm_rsb          ls_stub_rsb;    /* for returning errors */
        struct dlm_lkb          ls_stub_lkb;    /* for returning errors */
        struct dlm_message      ls_stub_ms;     /* for faking a reply */

        struct dentry           *ls_debug_rsb_dentry; /* debugfs */
        struct dentry           *ls_debug_waiters_dentry; /* debugfs */
        struct dentry           *ls_debug_locks_dentry; /* debugfs */
        struct dentry           *ls_debug_all_dentry; /* debugfs */
        struct dentry           *ls_debug_toss_dentry; /* debugfs */

        wait_queue_head_t       ls_uevent_wait; /* user part of join/leave */
        int                     ls_uevent_result;
        struct completion       ls_members_done;
        int                     ls_members_result;

        struct miscdevice       ls_device;

        struct workqueue_struct *ls_callback_wq;

        /* recovery related */

        struct mutex            ls_cb_mutex;
        struct list_head        ls_cb_delay; /* save for queue_work later */
        struct timer_list       ls_timer;
        struct task_struct      *ls_recoverd_task;
        struct mutex            ls_recoverd_active;
        spinlock_t              ls_recover_lock;
        unsigned long           ls_recover_begin; /* jiffies timestamp */
        uint32_t                ls_recover_status; /* DLM_RS_ */
        uint64_t                ls_recover_seq;
        struct dlm_recover      *ls_recover_args;
        struct rw_semaphore     ls_in_recovery; /* block local requests */
        struct rw_semaphore     ls_recv_active; /* block dlm_recv */
        struct list_head        ls_requestqueue;/* queue remote requests */
        struct mutex            ls_requestqueue_mutex;
        struct dlm_rcom         *ls_recover_buf;
        int                     ls_recover_nodeid; /* for debugging */
        unsigned int            ls_recover_dir_sent_res; /* for log info */
        unsigned int            ls_recover_dir_sent_msg; /* for log info */
        unsigned int            ls_recover_locks_in; /* for log info */
        uint64_t                ls_rcom_seq;
        spinlock_t              ls_rcom_spin;
        struct list_head        ls_recover_list;
        spinlock_t              ls_recover_list_lock;
        int                     ls_recover_list_count;
        struct idr              ls_recover_idr;
        spinlock_t              ls_recover_idr_lock;
        wait_queue_head_t       ls_wait_general;
        struct mutex            ls_clear_proc_locks;

        struct list_head        ls_root_list;   /* root resources */
        struct rw_semaphore     ls_root_sem;    /* protect root_list */

        const struct dlm_lockspace_ops *ls_ops;
        void                    *ls_ops_arg;

        int                     ls_namelen;
        char                    ls_name[1];
};

#define LSFL_WORK               0
#define LSFL_RUNNING            1
#define LSFL_RECOVERY_STOP      2
#define LSFL_RCOM_READY         3
#define LSFL_RCOM_WAIT          4
#define LSFL_UEVENT_WAIT        5
#define LSFL_TIMEWARN           6
#define LSFL_CB_DELAY           7
#define LSFL_NODIR              8

/* much of this is just saving user space pointers associated with the
   lock that we pass back to the user lib with an ast */

struct dlm_user_args {
        struct dlm_user_proc    *proc; /* each process that opens the lockspace
                                          device has private data
                                          (dlm_user_proc) on the struct file,
                                          the process's locks point back to it*/
        struct dlm_lksb         lksb;
        struct dlm_lksb __user  *user_lksb;
        void __user             *castparam;
        void __user             *castaddr;
        void __user             *bastparam;
        void __user             *bastaddr;
        uint64_t                xid;
};

#define DLM_PROC_FLAGS_CLOSING 1
#define DLM_PROC_FLAGS_COMPAT  2

/* locks list is kept so we can remove all a process's locks when it
   exits (or orphan those that are persistent) */

struct dlm_user_proc {
        dlm_lockspace_t         *lockspace;
        unsigned long           flags; /* DLM_PROC_FLAGS */
        struct list_head        asts;
        spinlock_t              asts_spin;
        struct list_head        locks;
        spinlock_t              locks_spin;
        struct list_head        unlocking;
        wait_queue_head_t       wait;
};

static inline int dlm_locking_stopped(struct dlm_ls *ls)
{
        return !test_bit(LSFL_RUNNING, &ls->ls_flags);
}

static inline int dlm_recovery_stopped(struct dlm_ls *ls)
{
        return test_bit(LSFL_RECOVERY_STOP, &ls->ls_flags);
}

static inline int dlm_no_directory(struct dlm_ls *ls)
{
        return test_bit(LSFL_NODIR, &ls->ls_flags);
}

int dlm_netlink_init(void);
void dlm_netlink_exit(void);
void dlm_timeout_warn(struct dlm_lkb *lkb);
int dlm_plock_init(void);
void dlm_plock_exit(void);

#ifdef CONFIG_DLM_DEBUG
int dlm_register_debugfs(void);
void dlm_unregister_debugfs(void);
int dlm_create_debug_file(struct dlm_ls *ls);
void dlm_delete_debug_file(struct dlm_ls *ls);
#else
static inline int dlm_register_debugfs(void) { return 0; }
static inline void dlm_unregister_debugfs(void) { }
static inline int dlm_create_debug_file(struct dlm_ls *ls) { return 0; }
static inline void dlm_delete_debug_file(struct dlm_ls *ls) { }
#endif

#endif                          /* __DLM_INTERNAL_DOT_H__ */