linux/fs/dlm/dlm_internal.h
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   1/******************************************************************************
   2*******************************************************************************
   3**
   4**  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
   5**  Copyright (C) 2004-2008 Red Hat, Inc.  All rights reserved.
   6**
   7**  This copyrighted material is made available to anyone wishing to use,
   8**  modify, copy, or redistribute it subject to the terms and conditions
   9**  of the GNU General Public License v.2.
  10**
  11*******************************************************************************
  12******************************************************************************/
  13
  14#ifndef __DLM_INTERNAL_DOT_H__
  15#define __DLM_INTERNAL_DOT_H__
  16
  17/*
  18 * This is the main header file to be included in each DLM source file.
  19 */
  20
  21#include <linux/module.h>
  22#include <linux/slab.h>
  23#include <linux/sched.h>
  24#include <linux/types.h>
  25#include <linux/ctype.h>
  26#include <linux/spinlock.h>
  27#include <linux/vmalloc.h>
  28#include <linux/list.h>
  29#include <linux/errno.h>
  30#include <linux/random.h>
  31#include <linux/delay.h>
  32#include <linux/socket.h>
  33#include <linux/kthread.h>
  34#include <linux/kobject.h>
  35#include <linux/kref.h>
  36#include <linux/kernel.h>
  37#include <linux/jhash.h>
  38#include <linux/miscdevice.h>
  39#include <linux/mutex.h>
  40#include <asm/uaccess.h>
  41
  42#include <linux/dlm.h>
  43#include "config.h"
  44
  45/* Size of the temp buffer midcomms allocates on the stack.
  46   We try to make this large enough so most messages fit.
  47   FIXME: should sctp make this unnecessary? */
  48
  49#define DLM_INBUF_LEN           148
  50
  51struct dlm_ls;
  52struct dlm_lkb;
  53struct dlm_rsb;
  54struct dlm_member;
  55struct dlm_lkbtable;
  56struct dlm_rsbtable;
  57struct dlm_dirtable;
  58struct dlm_direntry;
  59struct dlm_recover;
  60struct dlm_header;
  61struct dlm_message;
  62struct dlm_rcom;
  63struct dlm_mhandle;
  64
  65#define log_print(fmt, args...) \
  66        printk(KERN_ERR "dlm: "fmt"\n" , ##args)
  67#define log_error(ls, fmt, args...) \
  68        printk(KERN_ERR "dlm: %s: " fmt "\n", (ls)->ls_name , ##args)
  69
  70#define log_debug(ls, fmt, args...) \
  71do { \
  72        if (dlm_config.ci_log_debug) \
  73                printk(KERN_DEBUG "dlm: %s: " fmt "\n", \
  74                       (ls)->ls_name , ##args); \
  75} while (0)
  76
  77#define DLM_ASSERT(x, do) \
  78{ \
  79  if (!(x)) \
  80  { \
  81    printk(KERN_ERR "\nDLM:  Assertion failed on line %d of file %s\n" \
  82               "DLM:  assertion:  \"%s\"\n" \
  83               "DLM:  time = %lu\n", \
  84               __LINE__, __FILE__, #x, jiffies); \
  85    {do} \
  86    printk("\n"); \
  87    BUG(); \
  88    panic("DLM:  Record message above and reboot.\n"); \
  89  } \
  90}
  91
  92
  93struct dlm_direntry {
  94        struct list_head        list;
  95        uint32_t                master_nodeid;
  96        uint16_t                length;
  97        char                    name[1];
  98};
  99
 100struct dlm_dirtable {
 101        struct list_head        list;
 102        rwlock_t                lock;
 103};
 104
 105struct dlm_rsbtable {
 106        struct list_head        list;
 107        struct list_head        toss;
 108        rwlock_t                lock;
 109};
 110
 111struct dlm_lkbtable {
 112        struct list_head        list;
 113        rwlock_t                lock;
 114        uint16_t                counter;
 115};
 116
 117/*
 118 * Lockspace member (per node in a ls)
 119 */
 120
 121struct dlm_member {
 122        struct list_head        list;
 123        int                     nodeid;
 124        int                     weight;
 125};
 126
 127/*
 128 * Save and manage recovery state for a lockspace.
 129 */
 130
 131struct dlm_recover {
 132        struct list_head        list;
 133        int                     *nodeids;   /* nodeids of all members */
 134        int                     node_count;
 135        int                     *new;       /* nodeids of new members */
 136        int                     new_count;
 137        uint64_t                seq;
 138};
 139
 140/*
 141 * Pass input args to second stage locking function.
 142 */
 143
 144struct dlm_args {
 145        uint32_t                flags;
 146        void                    (*astfn) (void *astparam);
 147        void                    *astparam;
 148        void                    (*bastfn) (void *astparam, int mode);
 149        int                     mode;
 150        struct dlm_lksb         *lksb;
 151        unsigned long           timeout;
 152};
 153
 154
 155/*
 156 * Lock block
 157 *
 158 * A lock can be one of three types:
 159 *
 160 * local copy      lock is mastered locally
 161 *                 (lkb_nodeid is zero and DLM_LKF_MSTCPY is not set)
 162 * process copy    lock is mastered on a remote node
 163 *                 (lkb_nodeid is non-zero and DLM_LKF_MSTCPY is not set)
 164 * master copy     master node's copy of a lock owned by remote node
 165 *                 (lkb_nodeid is non-zero and DLM_LKF_MSTCPY is set)
 166 *
 167 * lkb_exflags: a copy of the most recent flags arg provided to dlm_lock or
 168 * dlm_unlock.  The dlm does not modify these or use any private flags in
 169 * this field; it only contains DLM_LKF_ flags from dlm.h.  These flags
 170 * are sent as-is to the remote master when the lock is remote.
 171 *
 172 * lkb_flags: internal dlm flags (DLM_IFL_ prefix) from dlm_internal.h.
 173 * Some internal flags are shared between the master and process nodes;
 174 * these shared flags are kept in the lower two bytes.  One of these
 175 * flags set on the master copy will be propagated to the process copy
 176 * and v.v.  Other internal flags are private to the master or process
 177 * node (e.g. DLM_IFL_MSTCPY).  These are kept in the high two bytes.
 178 *
 179 * lkb_sbflags: status block flags.  These flags are copied directly into
 180 * the caller's lksb.sb_flags prior to the dlm_lock/dlm_unlock completion
 181 * ast.  All defined in dlm.h with DLM_SBF_ prefix.
 182 *
 183 * lkb_status: the lock status indicates which rsb queue the lock is
 184 * on, grant, convert, or wait.  DLM_LKSTS_ WAITING/GRANTED/CONVERT
 185 *
 186 * lkb_wait_type: the dlm message type (DLM_MSG_ prefix) for which a
 187 * reply is needed.  Only set when the lkb is on the lockspace waiters
 188 * list awaiting a reply from a remote node.
 189 *
 190 * lkb_nodeid: when the lkb is a local copy, nodeid is 0; when the lkb
 191 * is a master copy, nodeid specifies the remote lock holder, when the
 192 * lkb is a process copy, the nodeid specifies the lock master.
 193 */
 194
 195/* lkb_ast_type */
 196
 197#define AST_COMP                1
 198#define AST_BAST                2
 199
 200/* lkb_status */
 201
 202#define DLM_LKSTS_WAITING       1
 203#define DLM_LKSTS_GRANTED       2
 204#define DLM_LKSTS_CONVERT       3
 205
 206/* lkb_flags */
 207
 208#define DLM_IFL_MSTCPY          0x00010000
 209#define DLM_IFL_RESEND          0x00020000
 210#define DLM_IFL_DEAD            0x00040000
 211#define DLM_IFL_OVERLAP_UNLOCK  0x00080000
 212#define DLM_IFL_OVERLAP_CANCEL  0x00100000
 213#define DLM_IFL_ENDOFLIFE       0x00200000
 214#define DLM_IFL_WATCH_TIMEWARN  0x00400000
 215#define DLM_IFL_TIMEOUT_CANCEL  0x00800000
 216#define DLM_IFL_DEADLOCK_CANCEL 0x01000000
 217#define DLM_IFL_USER            0x00000001
 218#define DLM_IFL_ORPHAN          0x00000002
 219
 220struct dlm_lkb {
 221        struct dlm_rsb          *lkb_resource;  /* the rsb */
 222        struct kref             lkb_ref;
 223        int                     lkb_nodeid;     /* copied from rsb */
 224        int                     lkb_ownpid;     /* pid of lock owner */
 225        uint32_t                lkb_id;         /* our lock ID */
 226        uint32_t                lkb_remid;      /* lock ID on remote partner */
 227        uint32_t                lkb_exflags;    /* external flags from caller */
 228        uint32_t                lkb_sbflags;    /* lksb flags */
 229        uint32_t                lkb_flags;      /* internal flags */
 230        uint32_t                lkb_lvbseq;     /* lvb sequence number */
 231
 232        int8_t                  lkb_status;     /* granted, waiting, convert */
 233        int8_t                  lkb_rqmode;     /* requested lock mode */
 234        int8_t                  lkb_grmode;     /* granted lock mode */
 235        int8_t                  lkb_bastmode;   /* requested mode */
 236        int8_t                  lkb_highbast;   /* highest mode bast sent for */
 237        int8_t                  lkb_wait_type;  /* type of reply waiting for */
 238        int8_t                  lkb_wait_count;
 239        int8_t                  lkb_ast_type;   /* type of ast queued for */
 240
 241        struct list_head        lkb_idtbl_list; /* lockspace lkbtbl */
 242        struct list_head        lkb_statequeue; /* rsb g/c/w list */
 243        struct list_head        lkb_rsb_lookup; /* waiting for rsb lookup */
 244        struct list_head        lkb_wait_reply; /* waiting for remote reply */
 245        struct list_head        lkb_astqueue;   /* need ast to be sent */
 246        struct list_head        lkb_ownqueue;   /* list of locks for a process */
 247        struct list_head        lkb_time_list;
 248        unsigned long           lkb_timestamp;
 249        unsigned long           lkb_timeout_cs;
 250
 251        char                    *lkb_lvbptr;
 252        struct dlm_lksb         *lkb_lksb;      /* caller's status block */
 253        void                    (*lkb_astfn) (void *astparam);
 254        void                    (*lkb_bastfn) (void *astparam, int mode);
 255        union {
 256                void                    *lkb_astparam;  /* caller's ast arg */
 257                struct dlm_user_args    *lkb_ua;
 258        };
 259};
 260
 261
 262struct dlm_rsb {
 263        struct dlm_ls           *res_ls;        /* the lockspace */
 264        struct kref             res_ref;
 265        struct mutex            res_mutex;
 266        unsigned long           res_flags;
 267        int                     res_length;     /* length of rsb name */
 268        int                     res_nodeid;
 269        uint32_t                res_lvbseq;
 270        uint32_t                res_hash;
 271        uint32_t                res_bucket;     /* rsbtbl */
 272        unsigned long           res_toss_time;
 273        uint32_t                res_first_lkid;
 274        struct list_head        res_lookup;     /* lkbs waiting on first */
 275        struct list_head        res_hashchain;  /* rsbtbl */
 276        struct list_head        res_grantqueue;
 277        struct list_head        res_convertqueue;
 278        struct list_head        res_waitqueue;
 279
 280        struct list_head        res_root_list;      /* used for recovery */
 281        struct list_head        res_recover_list;   /* used for recovery */
 282        int                     res_recover_locks_count;
 283
 284        char                    *res_lvbptr;
 285        char                    res_name[1];
 286};
 287
 288/* find_rsb() flags */
 289
 290#define R_MASTER                1       /* only return rsb if it's a master */
 291#define R_CREATE                2       /* create/add rsb if not found */
 292
 293/* rsb_flags */
 294
 295enum rsb_flags {
 296        RSB_MASTER_UNCERTAIN,
 297        RSB_VALNOTVALID,
 298        RSB_VALNOTVALID_PREV,
 299        RSB_NEW_MASTER,
 300        RSB_NEW_MASTER2,
 301        RSB_RECOVER_CONVERT,
 302        RSB_LOCKS_PURGED,
 303};
 304
 305static inline void rsb_set_flag(struct dlm_rsb *r, enum rsb_flags flag)
 306{
 307        __set_bit(flag, &r->res_flags);
 308}
 309
 310static inline void rsb_clear_flag(struct dlm_rsb *r, enum rsb_flags flag)
 311{
 312        __clear_bit(flag, &r->res_flags);
 313}
 314
 315static inline int rsb_flag(struct dlm_rsb *r, enum rsb_flags flag)
 316{
 317        return test_bit(flag, &r->res_flags);
 318}
 319
 320
 321/* dlm_header is first element of all structs sent between nodes */
 322
 323#define DLM_HEADER_MAJOR        0x00030000
 324#define DLM_HEADER_MINOR        0x00000000
 325
 326#define DLM_MSG                 1
 327#define DLM_RCOM                2
 328
 329struct dlm_header {
 330        uint32_t                h_version;
 331        uint32_t                h_lockspace;
 332        uint32_t                h_nodeid;       /* nodeid of sender */
 333        uint16_t                h_length;
 334        uint8_t                 h_cmd;          /* DLM_MSG, DLM_RCOM */
 335        uint8_t                 h_pad;
 336};
 337
 338
 339#define DLM_MSG_REQUEST         1
 340#define DLM_MSG_CONVERT         2
 341#define DLM_MSG_UNLOCK          3
 342#define DLM_MSG_CANCEL          4
 343#define DLM_MSG_REQUEST_REPLY   5
 344#define DLM_MSG_CONVERT_REPLY   6
 345#define DLM_MSG_UNLOCK_REPLY    7
 346#define DLM_MSG_CANCEL_REPLY    8
 347#define DLM_MSG_GRANT           9
 348#define DLM_MSG_BAST            10
 349#define DLM_MSG_LOOKUP          11
 350#define DLM_MSG_REMOVE          12
 351#define DLM_MSG_LOOKUP_REPLY    13
 352#define DLM_MSG_PURGE           14
 353
 354struct dlm_message {
 355        struct dlm_header       m_header;
 356        uint32_t                m_type;         /* DLM_MSG_ */
 357        uint32_t                m_nodeid;
 358        uint32_t                m_pid;
 359        uint32_t                m_lkid;         /* lkid on sender */
 360        uint32_t                m_remid;        /* lkid on receiver */
 361        uint32_t                m_parent_lkid;
 362        uint32_t                m_parent_remid;
 363        uint32_t                m_exflags;
 364        uint32_t                m_sbflags;
 365        uint32_t                m_flags;
 366        uint32_t                m_lvbseq;
 367        uint32_t                m_hash;
 368        int                     m_status;
 369        int                     m_grmode;
 370        int                     m_rqmode;
 371        int                     m_bastmode;
 372        int                     m_asts;
 373        int                     m_result;       /* 0 or -EXXX */
 374        char                    m_extra[0];     /* name or lvb */
 375};
 376
 377
 378#define DLM_RS_NODES            0x00000001
 379#define DLM_RS_NODES_ALL        0x00000002
 380#define DLM_RS_DIR              0x00000004
 381#define DLM_RS_DIR_ALL          0x00000008
 382#define DLM_RS_LOCKS            0x00000010
 383#define DLM_RS_LOCKS_ALL        0x00000020
 384#define DLM_RS_DONE             0x00000040
 385#define DLM_RS_DONE_ALL         0x00000080
 386
 387#define DLM_RCOM_STATUS         1
 388#define DLM_RCOM_NAMES          2
 389#define DLM_RCOM_LOOKUP         3
 390#define DLM_RCOM_LOCK           4
 391#define DLM_RCOM_STATUS_REPLY   5
 392#define DLM_RCOM_NAMES_REPLY    6
 393#define DLM_RCOM_LOOKUP_REPLY   7
 394#define DLM_RCOM_LOCK_REPLY     8
 395
 396struct dlm_rcom {
 397        struct dlm_header       rc_header;
 398        uint32_t                rc_type;        /* DLM_RCOM_ */
 399        int                     rc_result;      /* multi-purpose */
 400        uint64_t                rc_id;          /* match reply with request */
 401        uint64_t                rc_seq;         /* sender's ls_recover_seq */
 402        uint64_t                rc_seq_reply;   /* remote ls_recover_seq */
 403        char                    rc_buf[0];
 404};
 405
 406union dlm_packet {
 407        struct dlm_header       header;         /* common to other two */
 408        struct dlm_message      message;
 409        struct dlm_rcom         rcom;
 410};
 411
 412struct rcom_config {
 413        __le32                  rf_lvblen;
 414        __le32                  rf_lsflags;
 415        __le64                  rf_unused;
 416};
 417
 418struct rcom_lock {
 419        __le32                  rl_ownpid;
 420        __le32                  rl_lkid;
 421        __le32                  rl_remid;
 422        __le32                  rl_parent_lkid;
 423        __le32                  rl_parent_remid;
 424        __le32                  rl_exflags;
 425        __le32                  rl_flags;
 426        __le32                  rl_lvbseq;
 427        __le32                  rl_result;
 428        int8_t                  rl_rqmode;
 429        int8_t                  rl_grmode;
 430        int8_t                  rl_status;
 431        int8_t                  rl_asts;
 432        __le16                  rl_wait_type;
 433        __le16                  rl_namelen;
 434        char                    rl_name[DLM_RESNAME_MAXLEN];
 435        char                    rl_lvb[0];
 436};
 437
 438struct dlm_ls {
 439        struct list_head        ls_list;        /* list of lockspaces */
 440        dlm_lockspace_t         *ls_local_handle;
 441        uint32_t                ls_global_id;   /* global unique lockspace ID */
 442        uint32_t                ls_exflags;
 443        int                     ls_lvblen;
 444        int                     ls_count;       /* refcount of processes in
 445                                                   the dlm using this ls */
 446        int                     ls_create_count; /* create/release refcount */
 447        unsigned long           ls_flags;       /* LSFL_ */
 448        unsigned long           ls_scan_time;
 449        struct kobject          ls_kobj;
 450
 451        struct dlm_rsbtable     *ls_rsbtbl;
 452        uint32_t                ls_rsbtbl_size;
 453
 454        struct dlm_lkbtable     *ls_lkbtbl;
 455        uint32_t                ls_lkbtbl_size;
 456
 457        struct dlm_dirtable     *ls_dirtbl;
 458        uint32_t                ls_dirtbl_size;
 459
 460        struct mutex            ls_waiters_mutex;
 461        struct list_head        ls_waiters;     /* lkbs needing a reply */
 462
 463        struct mutex            ls_orphans_mutex;
 464        struct list_head        ls_orphans;
 465
 466        struct mutex            ls_timeout_mutex;
 467        struct list_head        ls_timeout;
 468
 469        struct list_head        ls_nodes;       /* current nodes in ls */
 470        struct list_head        ls_nodes_gone;  /* dead node list, recovery */
 471        int                     ls_num_nodes;   /* number of nodes in ls */
 472        int                     ls_low_nodeid;
 473        int                     ls_total_weight;
 474        int                     *ls_node_array;
 475        gfp_t                   ls_allocation;
 476
 477        struct dlm_rsb          ls_stub_rsb;    /* for returning errors */
 478        struct dlm_lkb          ls_stub_lkb;    /* for returning errors */
 479        struct dlm_message      ls_stub_ms;     /* for faking a reply */
 480
 481        struct dentry           *ls_debug_rsb_dentry; /* debugfs */
 482        struct dentry           *ls_debug_waiters_dentry; /* debugfs */
 483        struct dentry           *ls_debug_locks_dentry; /* debugfs */
 484
 485        wait_queue_head_t       ls_uevent_wait; /* user part of join/leave */
 486        int                     ls_uevent_result;
 487        struct completion       ls_members_done;
 488        int                     ls_members_result;
 489
 490        struct miscdevice       ls_device;
 491
 492        /* recovery related */
 493
 494        struct timer_list       ls_timer;
 495        struct task_struct      *ls_recoverd_task;
 496        struct mutex            ls_recoverd_active;
 497        spinlock_t              ls_recover_lock;
 498        unsigned long           ls_recover_begin; /* jiffies timestamp */
 499        uint32_t                ls_recover_status; /* DLM_RS_ */
 500        uint64_t                ls_recover_seq;
 501        struct dlm_recover      *ls_recover_args;
 502        struct rw_semaphore     ls_in_recovery; /* block local requests */
 503        struct rw_semaphore     ls_recv_active; /* block dlm_recv */
 504        struct list_head        ls_requestqueue;/* queue remote requests */
 505        struct mutex            ls_requestqueue_mutex;
 506        struct dlm_rcom         *ls_recover_buf;
 507        int                     ls_recover_nodeid; /* for debugging */
 508        uint64_t                ls_rcom_seq;
 509        spinlock_t              ls_rcom_spin;
 510        struct list_head        ls_recover_list;
 511        spinlock_t              ls_recover_list_lock;
 512        int                     ls_recover_list_count;
 513        wait_queue_head_t       ls_wait_general;
 514        struct mutex            ls_clear_proc_locks;
 515
 516        struct list_head        ls_root_list;   /* root resources */
 517        struct rw_semaphore     ls_root_sem;    /* protect root_list */
 518
 519        int                     ls_namelen;
 520        char                    ls_name[1];
 521};
 522
 523#define LSFL_WORK               0
 524#define LSFL_RUNNING            1
 525#define LSFL_RECOVERY_STOP      2
 526#define LSFL_RCOM_READY         3
 527#define LSFL_RCOM_WAIT          4
 528#define LSFL_UEVENT_WAIT        5
 529#define LSFL_TIMEWARN           6
 530
 531/* much of this is just saving user space pointers associated with the
 532   lock that we pass back to the user lib with an ast */
 533
 534struct dlm_user_args {
 535        struct dlm_user_proc    *proc; /* each process that opens the lockspace
 536                                          device has private data
 537                                          (dlm_user_proc) on the struct file,
 538                                          the process's locks point back to it*/
 539        struct dlm_lksb         lksb;
 540        int                     old_mode;
 541        int                     update_user_lvb;
 542        struct dlm_lksb __user  *user_lksb;
 543        void __user             *castparam;
 544        void __user             *castaddr;
 545        void __user             *bastparam;
 546        void __user             *bastaddr;
 547        uint64_t                xid;
 548};
 549
 550#define DLM_PROC_FLAGS_CLOSING 1
 551#define DLM_PROC_FLAGS_COMPAT  2
 552
 553/* locks list is kept so we can remove all a process's locks when it
 554   exits (or orphan those that are persistent) */
 555
 556struct dlm_user_proc {
 557        dlm_lockspace_t         *lockspace;
 558        unsigned long           flags; /* DLM_PROC_FLAGS */
 559        struct list_head        asts;
 560        spinlock_t              asts_spin;
 561        struct list_head        locks;
 562        spinlock_t              locks_spin;
 563        struct list_head        unlocking;
 564        wait_queue_head_t       wait;
 565};
 566
 567static inline int dlm_locking_stopped(struct dlm_ls *ls)
 568{
 569        return !test_bit(LSFL_RUNNING, &ls->ls_flags);
 570}
 571
 572static inline int dlm_recovery_stopped(struct dlm_ls *ls)
 573{
 574        return test_bit(LSFL_RECOVERY_STOP, &ls->ls_flags);
 575}
 576
 577static inline int dlm_no_directory(struct dlm_ls *ls)
 578{
 579        return (ls->ls_exflags & DLM_LSFL_NODIR) ? 1 : 0;
 580}
 581
 582int dlm_netlink_init(void);
 583void dlm_netlink_exit(void);
 584void dlm_timeout_warn(struct dlm_lkb *lkb);
 585int dlm_plock_init(void);
 586void dlm_plock_exit(void);
 587
 588#ifdef CONFIG_DLM_DEBUG
 589int dlm_register_debugfs(void);
 590void dlm_unregister_debugfs(void);
 591int dlm_create_debug_file(struct dlm_ls *ls);
 592void dlm_delete_debug_file(struct dlm_ls *ls);
 593#else
 594static inline int dlm_register_debugfs(void) { return 0; }
 595static inline void dlm_unregister_debugfs(void) { }
 596static inline int dlm_create_debug_file(struct dlm_ls *ls) { return 0; }
 597static inline void dlm_delete_debug_file(struct dlm_ls *ls) { }
 598#endif
 599
 600#endif                          /* __DLM_INTERNAL_DOT_H__ */
 601
 602
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