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