git.oblomov.eu Git - linux-2.6/blob - fs/dlm/rcom.c

   1 /******************************************************************************
   2 *******************************************************************************
   3 **
   4 **  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
   5 **  Copyright (C) 2005-2008 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 #include "dlm_internal.h"
  15 #include "lockspace.h"
  16 #include "member.h"
  17 #include "lowcomms.h"
  18 #include "midcomms.h"
  19 #include "rcom.h"
  20 #include "recover.h"
  21 #include "dir.h"
  22 #include "config.h"
  23 #include "memory.h"
  24 #include "lock.h"
  25 #include "util.h"
  26
  27
  28 static int rcom_response(struct dlm_ls *ls)
  29 {
  30         return test_bit(LSFL_RCOM_READY, &ls->ls_flags);
  31 }
  32
  33 static int create_rcom(struct dlm_ls *ls, int to_nodeid, int type, int len,
  34                        struct dlm_rcom **rc_ret, struct dlm_mhandle **mh_ret)
  35 {
  36         struct dlm_rcom *rc;
  37         struct dlm_mhandle *mh;
  38         char *mb;
  39         int mb_len = sizeof(struct dlm_rcom) + len;
  40
  41         mh = dlm_lowcomms_get_buffer(to_nodeid, mb_len, ls->ls_allocation, &mb);
  42         if (!mh) {
  43                 log_print("create_rcom to %d type %d len %d ENOBUFS",
  44                           to_nodeid, type, len);
  45                 return -ENOBUFS;
  46         }
  47         memset(mb, 0, mb_len);
  48
  49         rc = (struct dlm_rcom *) mb;
  50
  51         rc->rc_header.h_version = (DLM_HEADER_MAJOR | DLM_HEADER_MINOR);
  52         rc->rc_header.h_lockspace = ls->ls_global_id;
  53         rc->rc_header.h_nodeid = dlm_our_nodeid();
  54         rc->rc_header.h_length = mb_len;
  55         rc->rc_header.h_cmd = DLM_RCOM;
  56
  57         rc->rc_type = type;
  58
  59         spin_lock(&ls->ls_recover_lock);
  60         rc->rc_seq = ls->ls_recover_seq;
  61         spin_unlock(&ls->ls_recover_lock);
  62
  63         *mh_ret = mh;
  64         *rc_ret = rc;
  65         return 0;
  66 }
  67
  68 static void send_rcom(struct dlm_ls *ls, struct dlm_mhandle *mh,
  69                       struct dlm_rcom *rc)
  70 {
  71         dlm_rcom_out(rc);
  72         dlm_lowcomms_commit_buffer(mh);
  73 }
  74
  75 /* When replying to a status request, a node also sends back its
  76    configuration values.  The requesting node then checks that the remote
  77    node is configured the same way as itself. */
  78
  79 static void make_config(struct dlm_ls *ls, struct rcom_config *rf)
  80 {
  81         rf->rf_lvblen = cpu_to_le32(ls->ls_lvblen);
  82         rf->rf_lsflags = cpu_to_le32(ls->ls_exflags);
  83 }
  84
  85 static int check_config(struct dlm_ls *ls, struct dlm_rcom *rc, int nodeid)
  86 {
  87         struct rcom_config *rf = (struct rcom_config *) rc->rc_buf;
  88
  89         if ((rc->rc_header.h_version & 0xFFFF0000) != DLM_HEADER_MAJOR) {
  90                 log_error(ls, "version mismatch: %x nodeid %d: %x",
  91                           DLM_HEADER_MAJOR | DLM_HEADER_MINOR, nodeid,
  92                           rc->rc_header.h_version);
  93                 return -EPROTO;
  94         }
  95
  96         if (le32_to_cpu(rf->rf_lvblen) != ls->ls_lvblen ||
  97             le32_to_cpu(rf->rf_lsflags) != ls->ls_exflags) {
  98                 log_error(ls, "config mismatch: %d,%x nodeid %d: %d,%x",
  99                           ls->ls_lvblen, ls->ls_exflags, nodeid,
 100                           le32_to_cpu(rf->rf_lvblen),
 101                           le32_to_cpu(rf->rf_lsflags));
 102                 return -EPROTO;
 103         }
 104         return 0;
 105 }
 106
 107 static void allow_sync_reply(struct dlm_ls *ls, uint64_t *new_seq)
 108 {
 109         spin_lock(&ls->ls_rcom_spin);
 110         *new_seq = ++ls->ls_rcom_seq;
 111         set_bit(LSFL_RCOM_WAIT, &ls->ls_flags);
 112         spin_unlock(&ls->ls_rcom_spin);
 113 }
 114
 115 static void disallow_sync_reply(struct dlm_ls *ls)
 116 {
 117         spin_lock(&ls->ls_rcom_spin);
 118         clear_bit(LSFL_RCOM_WAIT, &ls->ls_flags);
 119         clear_bit(LSFL_RCOM_READY, &ls->ls_flags);
 120         spin_unlock(&ls->ls_rcom_spin);
 121 }
 122
 123 int dlm_rcom_status(struct dlm_ls *ls, int nodeid)
 124 {
 125         struct dlm_rcom *rc;
 126         struct dlm_mhandle *mh;
 127         int error = 0;
 128
 129         ls->ls_recover_nodeid = nodeid;
 130
 131         if (nodeid == dlm_our_nodeid()) {
 132                 rc = ls->ls_recover_buf;
 133                 rc->rc_result = dlm_recover_status(ls);
 134                 goto out;
 135         }
 136
 137         error = create_rcom(ls, nodeid, DLM_RCOM_STATUS, 0, &rc, &mh);
 138         if (error)
 139                 goto out;
 140
 141         allow_sync_reply(ls, &rc->rc_id);
 142         memset(ls->ls_recover_buf, 0, dlm_config.ci_buffer_size);
 143
 144         send_rcom(ls, mh, rc);
 145
 146         error = dlm_wait_function(ls, &rcom_response);
 147         disallow_sync_reply(ls);
 148         if (error)
 149                 goto out;
 150
 151         rc = ls->ls_recover_buf;
 152
 153         if (rc->rc_result == -ESRCH) {
 154                 /* we pretend the remote lockspace exists with 0 status */
 155                 log_debug(ls, "remote node %d not ready", nodeid);
 156                 rc->rc_result = 0;
 157         } else
 158                 error = check_config(ls, rc, nodeid);
 159         /* the caller looks at rc_result for the remote recovery status */
 160  out:
 161         return error;
 162 }
 163
 164 static void receive_rcom_status(struct dlm_ls *ls, struct dlm_rcom *rc_in)
 165 {
 166         struct dlm_rcom *rc;
 167         struct dlm_mhandle *mh;
 168         int error, nodeid = rc_in->rc_header.h_nodeid;
 169
 170         error = create_rcom(ls, nodeid, DLM_RCOM_STATUS_REPLY,
 171                             sizeof(struct rcom_config), &rc, &mh);
 172         if (error)
 173                 return;
 174         rc->rc_id = rc_in->rc_id;
 175         rc->rc_seq_reply = rc_in->rc_seq;
 176         rc->rc_result = dlm_recover_status(ls);
 177         make_config(ls, (struct rcom_config *) rc->rc_buf);
 178
 179         send_rcom(ls, mh, rc);
 180 }
 181
 182 static void receive_sync_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
 183 {
 184         spin_lock(&ls->ls_rcom_spin);
 185         if (!test_bit(LSFL_RCOM_WAIT, &ls->ls_flags) ||
 186             rc_in->rc_id != ls->ls_rcom_seq) {
 187                 log_debug(ls, "reject reply %d from %d seq %llx expect %llx",
 188                           rc_in->rc_type, rc_in->rc_header.h_nodeid,
 189                           (unsigned long long)rc_in->rc_id,
 190                           (unsigned long long)ls->ls_rcom_seq);
 191                 goto out;
 192         }
 193         memcpy(ls->ls_recover_buf, rc_in, rc_in->rc_header.h_length);
 194         set_bit(LSFL_RCOM_READY, &ls->ls_flags);
 195         clear_bit(LSFL_RCOM_WAIT, &ls->ls_flags);
 196         wake_up(&ls->ls_wait_general);
 197  out:
 198         spin_unlock(&ls->ls_rcom_spin);
 199 }
 200
 201 int dlm_rcom_names(struct dlm_ls *ls, int nodeid, char *last_name, int last_len)
 202 {
 203         struct dlm_rcom *rc;
 204         struct dlm_mhandle *mh;
 205         int error = 0;
 206         int max_size = dlm_config.ci_buffer_size - sizeof(struct dlm_rcom);
 207
 208         ls->ls_recover_nodeid = nodeid;
 209
 210         if (nodeid == dlm_our_nodeid()) {
 211                 dlm_copy_master_names(ls, last_name, last_len,
 212                                       ls->ls_recover_buf->rc_buf,
 213                                       max_size, nodeid);
 214                 goto out;
 215         }
 216
 217         error = create_rcom(ls, nodeid, DLM_RCOM_NAMES, last_len, &rc, &mh);
 218         if (error)
 219                 goto out;
 220         memcpy(rc->rc_buf, last_name, last_len);
 221
 222         allow_sync_reply(ls, &rc->rc_id);
 223         memset(ls->ls_recover_buf, 0, dlm_config.ci_buffer_size);
 224
 225         send_rcom(ls, mh, rc);
 226
 227         error = dlm_wait_function(ls, &rcom_response);
 228         disallow_sync_reply(ls);
 229  out:
 230         return error;
 231 }
 232
 233 static void receive_rcom_names(struct dlm_ls *ls, struct dlm_rcom *rc_in)
 234 {
 235         struct dlm_rcom *rc;
 236         struct dlm_mhandle *mh;
 237         int error, inlen, outlen, nodeid;
 238
 239         nodeid = rc_in->rc_header.h_nodeid;
 240         inlen = rc_in->rc_header.h_length - sizeof(struct dlm_rcom);
 241         outlen = dlm_config.ci_buffer_size - sizeof(struct dlm_rcom);
 242
 243         error = create_rcom(ls, nodeid, DLM_RCOM_NAMES_REPLY, outlen, &rc, &mh);
 244         if (error)
 245                 return;
 246         rc->rc_id = rc_in->rc_id;
 247         rc->rc_seq_reply = rc_in->rc_seq;
 248
 249         dlm_copy_master_names(ls, rc_in->rc_buf, inlen, rc->rc_buf, outlen,
 250                               nodeid);
 251         send_rcom(ls, mh, rc);
 252 }
 253
 254 int dlm_send_rcom_lookup(struct dlm_rsb *r, int dir_nodeid)
 255 {
 256         struct dlm_rcom *rc;
 257         struct dlm_mhandle *mh;
 258         struct dlm_ls *ls = r->res_ls;
 259         int error;
 260
 261         error = create_rcom(ls, dir_nodeid, DLM_RCOM_LOOKUP, r->res_length,
 262                             &rc, &mh);
 263         if (error)
 264                 goto out;
 265         memcpy(rc->rc_buf, r->res_name, r->res_length);
 266         rc->rc_id = (unsigned long) r;
 267
 268         send_rcom(ls, mh, rc);
 269  out:
 270         return error;
 271 }
 272
 273 static void receive_rcom_lookup(struct dlm_ls *ls, struct dlm_rcom *rc_in)
 274 {
 275         struct dlm_rcom *rc;
 276         struct dlm_mhandle *mh;
 277         int error, ret_nodeid, nodeid = rc_in->rc_header.h_nodeid;
 278         int len = rc_in->rc_header.h_length - sizeof(struct dlm_rcom);
 279
 280         error = create_rcom(ls, nodeid, DLM_RCOM_LOOKUP_REPLY, 0, &rc, &mh);
 281         if (error)
 282                 return;
 283
 284         error = dlm_dir_lookup(ls, nodeid, rc_in->rc_buf, len, &ret_nodeid);
 285         if (error)
 286                 ret_nodeid = error;
 287         rc->rc_result = ret_nodeid;
 288         rc->rc_id = rc_in->rc_id;
 289         rc->rc_seq_reply = rc_in->rc_seq;
 290
 291         send_rcom(ls, mh, rc);
 292 }
 293
 294 static void receive_rcom_lookup_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
 295 {
 296         dlm_recover_master_reply(ls, rc_in);
 297 }
 298
 299 static void pack_rcom_lock(struct dlm_rsb *r, struct dlm_lkb *lkb,
 300                            struct rcom_lock *rl)
 301 {
 302         memset(rl, 0, sizeof(*rl));
 303
 304         rl->rl_ownpid = cpu_to_le32(lkb->lkb_ownpid);
 305         rl->rl_lkid = cpu_to_le32(lkb->lkb_id);
 306         rl->rl_exflags = cpu_to_le32(lkb->lkb_exflags);
 307         rl->rl_flags = cpu_to_le32(lkb->lkb_flags);
 308         rl->rl_lvbseq = cpu_to_le32(lkb->lkb_lvbseq);
 309         rl->rl_rqmode = lkb->lkb_rqmode;
 310         rl->rl_grmode = lkb->lkb_grmode;
 311         rl->rl_status = lkb->lkb_status;
 312         rl->rl_wait_type = cpu_to_le16(lkb->lkb_wait_type);
 313
 314         if (lkb->lkb_bastaddr)
 315                 rl->rl_asts |= AST_BAST;
 316         if (lkb->lkb_astaddr)
 317                 rl->rl_asts |= AST_COMP;
 318
 319         rl->rl_namelen = cpu_to_le16(r->res_length);
 320         memcpy(rl->rl_name, r->res_name, r->res_length);
 321
 322         /* FIXME: might we have an lvb without DLM_LKF_VALBLK set ?
 323            If so, receive_rcom_lock_args() won't take this copy. */
 324
 325         if (lkb->lkb_lvbptr)
 326                 memcpy(rl->rl_lvb, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);
 327 }
 328
 329 int dlm_send_rcom_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
 330 {
 331         struct dlm_ls *ls = r->res_ls;
 332         struct dlm_rcom *rc;
 333         struct dlm_mhandle *mh;
 334         struct rcom_lock *rl;
 335         int error, len = sizeof(struct rcom_lock);
 336
 337         if (lkb->lkb_lvbptr)
 338                 len += ls->ls_lvblen;
 339
 340         error = create_rcom(ls, r->res_nodeid, DLM_RCOM_LOCK, len, &rc, &mh);
 341         if (error)
 342                 goto out;
 343
 344         rl = (struct rcom_lock *) rc->rc_buf;
 345         pack_rcom_lock(r, lkb, rl);
 346         rc->rc_id = (unsigned long) r;
 347
 348         send_rcom(ls, mh, rc);
 349  out:
 350         return error;
 351 }
 352
 353 static void receive_rcom_lock(struct dlm_ls *ls, struct dlm_rcom *rc_in)
 354 {
 355         struct dlm_rcom *rc;
 356         struct dlm_mhandle *mh;
 357         int error, nodeid = rc_in->rc_header.h_nodeid;
 358
 359         dlm_recover_master_copy(ls, rc_in);
 360
 361         error = create_rcom(ls, nodeid, DLM_RCOM_LOCK_REPLY,
 362                             sizeof(struct rcom_lock), &rc, &mh);
 363         if (error)
 364                 return;
 365
 366         /* We send back the same rcom_lock struct we received, but
 367            dlm_recover_master_copy() has filled in rl_remid and rl_result */
 368
 369         memcpy(rc->rc_buf, rc_in->rc_buf, sizeof(struct rcom_lock));
 370         rc->rc_id = rc_in->rc_id;
 371         rc->rc_seq_reply = rc_in->rc_seq;
 372
 373         send_rcom(ls, mh, rc);
 374 }
 375
 376 /* If the lockspace doesn't exist then still send a status message
 377    back; it's possible that it just doesn't have its global_id yet. */
 378
 379 int dlm_send_ls_not_ready(int nodeid, struct dlm_rcom *rc_in)
 380 {
 381         struct dlm_rcom *rc;
 382         struct rcom_config *rf;
 383         struct dlm_mhandle *mh;
 384         char *mb;
 385         int mb_len = sizeof(struct dlm_rcom) + sizeof(struct rcom_config);
 386
 387         mh = dlm_lowcomms_get_buffer(nodeid, mb_len, GFP_NOFS, &mb);
 388         if (!mh)
 389                 return -ENOBUFS;
 390         memset(mb, 0, mb_len);
 391
 392         rc = (struct dlm_rcom *) mb;
 393
 394         rc->rc_header.h_version = (DLM_HEADER_MAJOR | DLM_HEADER_MINOR);
 395         rc->rc_header.h_lockspace = rc_in->rc_header.h_lockspace;
 396         rc->rc_header.h_nodeid = dlm_our_nodeid();
 397         rc->rc_header.h_length = mb_len;
 398         rc->rc_header.h_cmd = DLM_RCOM;
 399
 400         rc->rc_type = DLM_RCOM_STATUS_REPLY;
 401         rc->rc_id = rc_in->rc_id;
 402         rc->rc_seq_reply = rc_in->rc_seq;
 403         rc->rc_result = -ESRCH;
 404
 405         rf = (struct rcom_config *) rc->rc_buf;
 406         rf->rf_lvblen = cpu_to_le32(~0U);
 407
 408         dlm_rcom_out(rc);
 409         dlm_lowcomms_commit_buffer(mh);
 410
 411         return 0;
 412 }
 413
 414 static int is_old_reply(struct dlm_ls *ls, struct dlm_rcom *rc)
 415 {
 416         uint64_t seq;
 417         int rv = 0;
 418
 419         switch (rc->rc_type) {
 420         case DLM_RCOM_STATUS_REPLY:
 421         case DLM_RCOM_NAMES_REPLY:
 422         case DLM_RCOM_LOOKUP_REPLY:
 423         case DLM_RCOM_LOCK_REPLY:
 424                 spin_lock(&ls->ls_recover_lock);
 425                 seq = ls->ls_recover_seq;
 426                 spin_unlock(&ls->ls_recover_lock);
 427                 if (rc->rc_seq_reply != seq) {
 428                         log_debug(ls, "ignoring old reply %x from %d "
 429                                       "seq_reply %llx expect %llx",
 430                                       rc->rc_type, rc->rc_header.h_nodeid,
 431                                       (unsigned long long)rc->rc_seq_reply,
 432                                       (unsigned long long)seq);
 433                         rv = 1;
 434                 }
 435         }
 436         return rv;
 437 }
 438
 439 /* Called by dlm_recv; corresponds to dlm_receive_message() but special
 440    recovery-only comms are sent through here. */
 441
 442 void dlm_receive_rcom(struct dlm_ls *ls, struct dlm_rcom *rc, int nodeid)
 443 {
 444         if (dlm_recovery_stopped(ls) && (rc->rc_type != DLM_RCOM_STATUS)) {
 445                 log_debug(ls, "ignoring recovery message %x from %d",
 446                           rc->rc_type, nodeid);
 447                 goto out;
 448         }
 449
 450         if (is_old_reply(ls, rc))
 451                 goto out;
 452
 453         switch (rc->rc_type) {
 454         case DLM_RCOM_STATUS:
 455                 receive_rcom_status(ls, rc);
 456                 break;
 457
 458         case DLM_RCOM_NAMES:
 459                 receive_rcom_names(ls, rc);
 460                 break;
 461
 462         case DLM_RCOM_LOOKUP:
 463                 receive_rcom_lookup(ls, rc);
 464                 break;
 465
 466         case DLM_RCOM_LOCK:
 467                 receive_rcom_lock(ls, rc);
 468                 break;
 469
 470         case DLM_RCOM_STATUS_REPLY:
 471                 receive_sync_reply(ls, rc);
 472                 break;
 473
 474         case DLM_RCOM_NAMES_REPLY:
 475                 receive_sync_reply(ls, rc);
 476                 break;
 477
 478         case DLM_RCOM_LOOKUP_REPLY:
 479                 receive_rcom_lookup_reply(ls, rc);
 480                 break;
 481
 482         case DLM_RCOM_LOCK_REPLY:
 483                 dlm_recover_process_copy(ls, rc);
 484                 break;
 485
 486         default:
 487                 log_error(ls, "receive_rcom bad type %d", rc->rc_type);
 488         }
 489  out:
 490         return;
 491 }
 492