fs/dlm/dlm_internal.h

   1 /******************************************************************************
   2 *******************************************************************************
   3 **
   4 **  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
   5 **  Copyright (C) 2004-2005 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/mutex.h>
  39 #include <asm/semaphore.h>
  40 #include <asm/uaccess.h>
  41
  42 #include <linux/dlm.h>
  43
  44 #define DLM_LOCKSPACE_LEN       64
  45
  46 /* Size of the temp buffer midcomms allocates on the stack.
  47    We try to make this large enough so most messages fit.
  48    FIXME: should sctp make this unnecessary? */
  49
  50 #define DLM_INBUF_LEN           148
  51
  52 struct dlm_ls;
  53 struct dlm_lkb;
  54 struct dlm_rsb;
  55 struct dlm_member;
  56 struct dlm_lkbtable;
  57 struct dlm_rsbtable;
  58 struct dlm_dirtable;
  59 struct dlm_direntry;
  60 struct dlm_recover;
  61 struct dlm_header;
  62 struct dlm_message;
  63 struct dlm_rcom;
  64 struct dlm_mhandle;
  65
  66 #define log_print(fmt, args...) \
  67         printk(KERN_ERR "dlm: "fmt"\n" , ##args)
  68 #define log_error(ls, fmt, args...) \
  69         printk(KERN_ERR "dlm: %s: " fmt "\n", (ls)->ls_name , ##args)
  70
  71 #ifdef DLM_LOG_DEBUG
  72 #define log_debug(ls, fmt, args...) log_error(ls, fmt, ##args)
  73 #else
  74 #define log_debug(ls, fmt, args...)
  75 #endif
  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
  93 struct dlm_direntry {
  94         struct list_head        list;
  95         uint32_t                master_nodeid;
  96         uint16_t                length;
  97         char                    name[1];
  98 };
  99
 100 struct dlm_dirtable {
 101         struct list_head        list;
 102         rwlock_t                lock;
 103 };
 104
 105 struct dlm_rsbtable {
 106         struct list_head        list;
 107         struct list_head        toss;
 108         rwlock_t                lock;
 109 };
 110
 111 struct 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
 121 struct 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
 131 struct dlm_recover {
 132         struct list_head        list;
 133         int                     *nodeids;
 134         int                     node_count;
 135         uint64_t                seq;
 136 };
 137
 138 /*
 139  * Pass input args to second stage locking function.
 140  */
 141
 142 struct dlm_args {
 143         uint32_t                flags;
 144         void                    *astaddr;
 145         long                    astparam;
 146         void                    *bastaddr;
 147         int                     mode;
 148         struct dlm_lksb         *lksb;
 149 };
 150
 151
 152 /*
 153  * Lock block
 154  *
 155  * A lock can be one of three types:
 156  *
 157  * local copy      lock is mastered locally
 158  *                 (lkb_nodeid is zero and DLM_LKF_MSTCPY is not set)
 159  * process copy    lock is mastered on a remote node
 160  *                 (lkb_nodeid is non-zero and DLM_LKF_MSTCPY is not set)
 161  * master copy     master node's copy of a lock owned by remote node
 162  *                 (lkb_nodeid is non-zero and DLM_LKF_MSTCPY is set)
 163  *
 164  * lkb_exflags: a copy of the most recent flags arg provided to dlm_lock or
 165  * dlm_unlock.  The dlm does not modify these or use any private flags in
 166  * this field; it only contains DLM_LKF_ flags from dlm.h.  These flags
 167  * are sent as-is to the remote master when the lock is remote.
 168  *
 169  * lkb_flags: internal dlm flags (DLM_IFL_ prefix) from dlm_internal.h.
 170  * Some internal flags are shared between the master and process nodes;
 171  * these shared flags are kept in the lower two bytes.  One of these
 172  * flags set on the master copy will be propagated to the process copy
 173  * and v.v.  Other internal flags are private to the master or process
 174  * node (e.g. DLM_IFL_MSTCPY).  These are kept in the high two bytes.
 175  *
 176  * lkb_sbflags: status block flags.  These flags are copied directly into
 177  * the caller's lksb.sb_flags prior to the dlm_lock/dlm_unlock completion
 178  * ast.  All defined in dlm.h with DLM_SBF_ prefix.
 179  *
 180  * lkb_status: the lock status indicates which rsb queue the lock is
 181  * on, grant, convert, or wait.  DLM_LKSTS_ WAITING/GRANTED/CONVERT
 182  *
 183  * lkb_wait_type: the dlm message type (DLM_MSG_ prefix) for which a
 184  * reply is needed.  Only set when the lkb is on the lockspace waiters
 185  * list awaiting a reply from a remote node.
 186  *
 187  * lkb_nodeid: when the lkb is a local copy, nodeid is 0; when the lkb
 188  * is a master copy, nodeid specifies the remote lock holder, when the
 189  * lkb is a process copy, the nodeid specifies the lock master.
 190  */
 191
 192 /* lkb_ast_type */
 193
 194 #define AST_COMP                1
 195 #define AST_BAST                2
 196
 197 /* lkb_status */
 198
 199 #define DLM_LKSTS_WAITING       1
 200 #define DLM_LKSTS_GRANTED       2
 201 #define DLM_LKSTS_CONVERT       3
 202
 203 /* lkb_flags */
 204
 205 #define DLM_IFL_MSTCPY          0x00010000
 206 #define DLM_IFL_RESEND          0x00020000
 207
 208 struct dlm_lkb {
 209         struct dlm_rsb          *lkb_resource;  /* the rsb */
 210         struct kref             lkb_ref;
 211         int                     lkb_nodeid;     /* copied from rsb */
 212         int                     lkb_ownpid;     /* pid of lock owner */
 213         uint32_t                lkb_id;         /* our lock ID */
 214         uint32_t                lkb_remid;      /* lock ID on remote partner */
 215         uint32_t                lkb_exflags;    /* external flags from caller */
 216         uint32_t                lkb_sbflags;    /* lksb flags */
 217         uint32_t                lkb_flags;      /* internal flags */
 218         uint32_t                lkb_lvbseq;     /* lvb sequence number */
 219
 220         int8_t                  lkb_status;     /* granted, waiting, convert */
 221         int8_t                  lkb_rqmode;     /* requested lock mode */
 222         int8_t                  lkb_grmode;     /* granted lock mode */
 223         int8_t                  lkb_bastmode;   /* requested mode */
 224         int8_t                  lkb_highbast;   /* highest mode bast sent for */
 225
 226         int8_t                  lkb_wait_type;  /* type of reply waiting for */
 227         int8_t                  lkb_ast_type;   /* type of ast queued for */
 228
 229         struct list_head        lkb_idtbl_list; /* lockspace lkbtbl */
 230         struct list_head        lkb_statequeue; /* rsb g/c/w list */
 231         struct list_head        lkb_rsb_lookup; /* waiting for rsb lookup */
 232         struct list_head        lkb_wait_reply; /* waiting for remote reply */
 233         struct list_head        lkb_astqueue;   /* need ast to be sent */
 234
 235         char                    *lkb_lvbptr;
 236         struct dlm_lksb         *lkb_lksb;      /* caller's status block */
 237         void                    *lkb_astaddr;   /* caller's ast function */
 238         void                    *lkb_bastaddr;  /* caller's bast function */
 239         long                    lkb_astparam;   /* caller's ast arg */
 240 };
 241
 242
 243 struct dlm_rsb {
 244         struct dlm_ls           *res_ls;        /* the lockspace */
 245         struct kref             res_ref;
 246         struct mutex            res_mutex;
 247         unsigned long           res_flags;
 248         int                     res_length;     /* length of rsb name */
 249         int                     res_nodeid;
 250         uint32_t                res_lvbseq;
 251         uint32_t                res_hash;
 252         uint32_t                res_bucket;     /* rsbtbl */
 253         unsigned long           res_toss_time;
 254         uint32_t                res_first_lkid;
 255         struct list_head        res_lookup;     /* lkbs waiting on first */
 256         struct list_head        res_hashchain;  /* rsbtbl */
 257         struct list_head        res_grantqueue;
 258         struct list_head        res_convertqueue;
 259         struct list_head        res_waitqueue;
 260
 261         struct list_head        res_root_list;      /* used for recovery */
 262         struct list_head        res_recover_list;   /* used for recovery */
 263         int                     res_recover_locks_count;
 264
 265         char                    *res_lvbptr;
 266         char                    res_name[1];
 267 };
 268
 269 /* find_rsb() flags */
 270
 271 #define R_MASTER                1       /* only return rsb if it's a master */
 272 #define R_CREATE                2       /* create/add rsb if not found */
 273
 274 /* rsb_flags */
 275
 276 enum rsb_flags {
 277         RSB_MASTER_UNCERTAIN,
 278         RSB_VALNOTVALID,
 279         RSB_VALNOTVALID_PREV,
 280         RSB_NEW_MASTER,
 281         RSB_NEW_MASTER2,
 282         RSB_RECOVER_CONVERT,
 283 };
 284
 285 static inline void rsb_set_flag(struct dlm_rsb *r, enum rsb_flags flag)
 286 {
 287         __set_bit(flag, &r->res_flags);
 288 }
 289
 290 static inline void rsb_clear_flag(struct dlm_rsb *r, enum rsb_flags flag)
 291 {
 292         __clear_bit(flag, &r->res_flags);
 293 }
 294
 295 static inline int rsb_flag(struct dlm_rsb *r, enum rsb_flags flag)
 296 {
 297         return test_bit(flag, &r->res_flags);
 298 }
 299
 300
 301 /* dlm_header is first element of all structs sent between nodes */
 302
 303 #define DLM_HEADER_MAJOR        0x00020000
 304 #define DLM_HEADER_MINOR        0x00000001
 305
 306 #define DLM_MSG                 1
 307 #define DLM_RCOM                2
 308
 309 struct dlm_header {
 310         uint32_t                h_version;
 311         uint32_t                h_lockspace;
 312         uint32_t                h_nodeid;       /* nodeid of sender */
 313         uint16_t                h_length;
 314         uint8_t                 h_cmd;          /* DLM_MSG, DLM_RCOM */
 315         uint8_t                 h_pad;
 316 };
 317
 318
 319 #define DLM_MSG_REQUEST         1
 320 #define DLM_MSG_CONVERT         2
 321 #define DLM_MSG_UNLOCK          3
 322 #define DLM_MSG_CANCEL          4
 323 #define DLM_MSG_REQUEST_REPLY   5
 324 #define DLM_MSG_CONVERT_REPLY   6
 325 #define DLM_MSG_UNLOCK_REPLY    7
 326 #define DLM_MSG_CANCEL_REPLY    8
 327 #define DLM_MSG_GRANT           9
 328 #define DLM_MSG_BAST            10
 329 #define DLM_MSG_LOOKUP          11
 330 #define DLM_MSG_REMOVE          12
 331 #define DLM_MSG_LOOKUP_REPLY    13
 332
 333 struct dlm_message {
 334         struct dlm_header       m_header;
 335         uint32_t                m_type;         /* DLM_MSG_ */
 336         uint32_t                m_nodeid;
 337         uint32_t                m_pid;
 338         uint32_t                m_lkid;         /* lkid on sender */
 339         uint32_t                m_remid;        /* lkid on receiver */
 340         uint32_t                m_parent_lkid;
 341         uint32_t                m_parent_remid;
 342         uint32_t                m_exflags;
 343         uint32_t                m_sbflags;
 344         uint32_t                m_flags;
 345         uint32_t                m_lvbseq;
 346         uint32_t                m_hash;
 347         int                     m_status;
 348         int                     m_grmode;
 349         int                     m_rqmode;
 350         int                     m_bastmode;
 351         int                     m_asts;
 352         int                     m_result;       /* 0 or -EXXX */
 353         char                    m_extra[0];     /* name or lvb */
 354 };
 355
 356
 357 #define DLM_RS_NODES            0x00000001
 358 #define DLM_RS_NODES_ALL        0x00000002
 359 #define DLM_RS_DIR              0x00000004
 360 #define DLM_RS_DIR_ALL          0x00000008
 361 #define DLM_RS_LOCKS            0x00000010
 362 #define DLM_RS_LOCKS_ALL        0x00000020
 363 #define DLM_RS_DONE             0x00000040
 364 #define DLM_RS_DONE_ALL         0x00000080
 365
 366 #define DLM_RCOM_STATUS         1
 367 #define DLM_RCOM_NAMES          2
 368 #define DLM_RCOM_LOOKUP         3
 369 #define DLM_RCOM_LOCK           4
 370 #define DLM_RCOM_STATUS_REPLY   5
 371 #define DLM_RCOM_NAMES_REPLY    6
 372 #define DLM_RCOM_LOOKUP_REPLY   7
 373 #define DLM_RCOM_LOCK_REPLY     8
 374
 375 struct dlm_rcom {
 376         struct dlm_header       rc_header;
 377         uint32_t                rc_type;        /* DLM_RCOM_ */
 378         int                     rc_result;      /* multi-purpose */
 379         uint64_t                rc_id;          /* match reply with request */
 380         char                    rc_buf[0];
 381 };
 382
 383 struct rcom_config {
 384         uint32_t                rf_lvblen;
 385         uint32_t                rf_lsflags;
 386         uint64_t                rf_unused;
 387 };
 388
 389 struct rcom_lock {
 390         uint32_t                rl_ownpid;
 391         uint32_t                rl_lkid;
 392         uint32_t                rl_remid;
 393         uint32_t                rl_parent_lkid;
 394         uint32_t                rl_parent_remid;
 395         uint32_t                rl_exflags;
 396         uint32_t                rl_flags;
 397         uint32_t                rl_lvbseq;
 398         int                     rl_result;
 399         int8_t                  rl_rqmode;
 400         int8_t                  rl_grmode;
 401         int8_t                  rl_status;
 402         int8_t                  rl_asts;
 403         uint16_t                rl_wait_type;
 404         uint16_t                rl_namelen;
 405         char                    rl_name[DLM_RESNAME_MAXLEN];
 406         char                    rl_lvb[0];
 407 };
 408
 409 struct dlm_ls {
 410         struct list_head        ls_list;        /* list of lockspaces */
 411         uint32_t                ls_global_id;   /* global unique lockspace ID */
 412         uint32_t                ls_exflags;
 413         int                     ls_lvblen;
 414         int                     ls_count;       /* reference count */
 415         unsigned long           ls_flags;       /* LSFL_ */
 416         struct kobject          ls_kobj;
 417
 418         struct dlm_rsbtable     *ls_rsbtbl;
 419         uint32_t                ls_rsbtbl_size;
 420
 421         struct dlm_lkbtable     *ls_lkbtbl;
 422         uint32_t                ls_lkbtbl_size;
 423
 424         struct dlm_dirtable     *ls_dirtbl;
 425         uint32_t                ls_dirtbl_size;
 426
 427         struct mutex            ls_waiters_mutex;
 428         struct list_head        ls_waiters;     /* lkbs needing a reply */
 429
 430         struct list_head        ls_nodes;       /* current nodes in ls */
 431         struct list_head        ls_nodes_gone;  /* dead node list, recovery */
 432         int                     ls_num_nodes;   /* number of nodes in ls */
 433         int                     ls_low_nodeid;
 434         int                     ls_total_weight;
 435         int                     *ls_node_array;
 436
 437         struct dlm_rsb          ls_stub_rsb;    /* for returning errors */
 438         struct dlm_lkb          ls_stub_lkb;    /* for returning errors */
 439         struct dlm_message      ls_stub_ms;     /* for faking a reply */
 440
 441         struct dentry           *ls_debug_dentry; /* debugfs */
 442
 443         wait_queue_head_t       ls_uevent_wait; /* user part of join/leave */
 444         int                     ls_uevent_result;
 445
 446         /* recovery related */
 447
 448         struct timer_list       ls_timer;
 449         struct task_struct      *ls_recoverd_task;
 450         struct mutex            ls_recoverd_active;
 451         spinlock_t              ls_recover_lock;
 452         uint32_t                ls_recover_status; /* DLM_RS_ */
 453         uint64_t                ls_recover_seq;
 454         struct dlm_recover      *ls_recover_args;
 455         struct rw_semaphore     ls_in_recovery; /* block local requests */
 456         struct list_head        ls_requestqueue;/* queue remote requests */
 457         struct mutex            ls_requestqueue_mutex;
 458         char                    *ls_recover_buf;
 459         struct list_head        ls_recover_list;
 460         spinlock_t              ls_recover_list_lock;
 461         int                     ls_recover_list_count;
 462         wait_queue_head_t       ls_wait_general;
 463
 464         struct list_head        ls_root_list;   /* root resources */
 465         struct rw_semaphore     ls_root_sem;    /* protect root_list */
 466
 467         int                     ls_namelen;
 468         char                    ls_name[1];
 469 };
 470
 471 #define LSFL_WORK               0
 472 #define LSFL_RUNNING            1
 473 #define LSFL_RECOVERY_STOP      2
 474 #define LSFL_RCOM_READY         3
 475 #define LSFL_UEVENT_WAIT        4
 476
 477 static inline int dlm_locking_stopped(struct dlm_ls *ls)
 478 {
 479         return !test_bit(LSFL_RUNNING, &ls->ls_flags);
 480 }
 481
 482 static inline int dlm_recovery_stopped(struct dlm_ls *ls)
 483 {
 484         return test_bit(LSFL_RECOVERY_STOP, &ls->ls_flags);
 485 }
 486
 487 static inline int dlm_no_directory(struct dlm_ls *ls)
 488 {
 489         return (ls->ls_exflags & DLM_LSFL_NODIR) ? 1 : 0;
 490 }
 491
 492 #endif                          /* __DLM_INTERNAL_DOT_H__ */
 493