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) 2005-2007 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 static void receive_rcom_status_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
 201 {
 202         receive_sync_reply(ls, rc_in);
 203 }
 204
 205 int dlm_rcom_names(struct dlm_ls *ls, int nodeid, char *last_name, int last_len)
 206 {
 207         struct dlm_rcom *rc;
 208         struct dlm_mhandle *mh;
 209         int error = 0, len = sizeof(struct dlm_rcom);
 210
 211         ls->ls_recover_nodeid = nodeid;
 212
 213         if (nodeid == dlm_our_nodeid()) {
 214                 dlm_copy_master_names(ls, last_name, last_len,
 215                                       ls->ls_recover_buf + len,
 216                                       dlm_config.ci_buffer_size - len, nodeid);
 217                 goto out;
 218         }
 219
 220         error = create_rcom(ls, nodeid, DLM_RCOM_NAMES, last_len, &rc, &mh);
 221         if (error)
 222                 goto out;
 223         memcpy(rc->rc_buf, last_name, last_len);
 224
 225         allow_sync_reply(ls, &rc->rc_id);
 226         memset(ls->ls_recover_buf, 0, dlm_config.ci_buffer_size);
 227
 228         send_rcom(ls, mh, rc);
 229
 230         error = dlm_wait_function(ls, &rcom_response);
 231         disallow_sync_reply(ls);
 232  out:
 233         return error;
 234 }
 235
 236 static void receive_rcom_names(struct dlm_ls *ls, struct dlm_rcom *rc_in)
 237 {
 238         struct dlm_rcom *rc;
 239         struct dlm_mhandle *mh;
 240         int error, inlen, outlen, nodeid;
 241
 242         nodeid = rc_in->rc_header.h_nodeid;
 243         inlen = rc_in->rc_header.h_length - sizeof(struct dlm_rcom);
 244         outlen = dlm_config.ci_buffer_size - sizeof(struct dlm_rcom);
 245
 246         error = create_rcom(ls, nodeid, DLM_RCOM_NAMES_REPLY, outlen, &rc, &mh);
 247         if (error)
 248                 return;
 249         rc->rc_id = rc_in->rc_id;
 250         rc->rc_seq_reply = rc_in->rc_seq;
 251
 252         dlm_copy_master_names(ls, rc_in->rc_buf, inlen, rc->rc_buf, outlen,
 253                               nodeid);
 254         send_rcom(ls, mh, rc);
 255 }
 256
 257 static void receive_rcom_names_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
 258 {
 259         receive_sync_reply(ls, rc_in);
 260 }
 261
 262 int dlm_send_rcom_lookup(struct dlm_rsb *r, int dir_nodeid)
 263 {
 264         struct dlm_rcom *rc;
 265         struct dlm_mhandle *mh;
 266         struct dlm_ls *ls = r->res_ls;
 267         int error;
 268
 269         error = create_rcom(ls, dir_nodeid, DLM_RCOM_LOOKUP, r->res_length,
 270                             &rc, &mh);
 271         if (error)
 272                 goto out;
 273         memcpy(rc->rc_buf, r->res_name, r->res_length);
 274         rc->rc_id = (unsigned long) r;
 275
 276         send_rcom(ls, mh, rc);
 277  out:
 278         return error;
 279 }
 280
 281 static void receive_rcom_lookup(struct dlm_ls *ls, struct dlm_rcom *rc_in)
 282 {
 283         struct dlm_rcom *rc;
 284         struct dlm_mhandle *mh;
 285         int error, ret_nodeid, nodeid = rc_in->rc_header.h_nodeid;
 286         int len = rc_in->rc_header.h_length - sizeof(struct dlm_rcom);
 287
 288         error = create_rcom(ls, nodeid, DLM_RCOM_LOOKUP_REPLY, 0, &rc, &mh);
 289         if (error)
 290                 return;
 291
 292         error = dlm_dir_lookup(ls, nodeid, rc_in->rc_buf, len, &ret_nodeid);
 293         if (error)
 294                 ret_nodeid = error;
 295         rc->rc_result = ret_nodeid;
 296         rc->rc_id = rc_in->rc_id;
 297         rc->rc_seq_reply = rc_in->rc_seq;
 298
 299         send_rcom(ls, mh, rc);
 300 }
 301
 302 static void receive_rcom_lookup_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
 303 {
 304         dlm_recover_master_reply(ls, rc_in);
 305 }
 306
 307 static void pack_rcom_lock(struct dlm_rsb *r, struct dlm_lkb *lkb,
 308                            struct rcom_lock *rl)
 309 {
 310         memset(rl, 0, sizeof(*rl));
 311
 312         rl->rl_ownpid = lkb->lkb_ownpid;
 313         rl->rl_lkid = lkb->lkb_id;
 314         rl->rl_exflags = lkb->lkb_exflags;
 315         rl->rl_flags = lkb->lkb_flags;
 316         rl->rl_lvbseq = lkb->lkb_lvbseq;
 317         rl->rl_rqmode = lkb->lkb_rqmode;
 318         rl->rl_grmode = lkb->lkb_grmode;
 319         rl->rl_status = lkb->lkb_status;
 320         rl->rl_wait_type = lkb->lkb_wait_type;
 321
 322         if (lkb->lkb_bastaddr)
 323                 rl->rl_asts |= AST_BAST;
 324         if (lkb->lkb_astaddr)
 325                 rl->rl_asts |= AST_COMP;
 326
 327         rl->rl_namelen = r->res_length;
 328         memcpy(rl->rl_name, r->res_name, r->res_length);
 329
 330         /* FIXME: might we have an lvb without DLM_LKF_VALBLK set ?
 331            If so, receive_rcom_lock_args() won't take this copy. */
 332
 333         if (lkb->lkb_lvbptr)
 334                 memcpy(rl->rl_lvb, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);
 335 }
 336
 337 int dlm_send_rcom_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
 338 {
 339         struct dlm_ls *ls = r->res_ls;
 340         struct dlm_rcom *rc;
 341         struct dlm_mhandle *mh;
 342         struct rcom_lock *rl;
 343         int error, len = sizeof(struct rcom_lock);
 344
 345         if (lkb->lkb_lvbptr)
 346                 len += ls->ls_lvblen;
 347
 348         error = create_rcom(ls, r->res_nodeid, DLM_RCOM_LOCK, len, &rc, &mh);
 349         if (error)
 350                 goto out;
 351
 352         rl = (struct rcom_lock *) rc->rc_buf;
 353         pack_rcom_lock(r, lkb, rl);
 354         rc->rc_id = (unsigned long) r;
 355
 356         send_rcom(ls, mh, rc);
 357  out:
 358         return error;
 359 }
 360
 361 static void receive_rcom_lock(struct dlm_ls *ls, struct dlm_rcom *rc_in)
 362 {
 363         struct dlm_rcom *rc;
 364         struct dlm_mhandle *mh;
 365         int error, nodeid = rc_in->rc_header.h_nodeid;
 366
 367         dlm_recover_master_copy(ls, rc_in);
 368
 369         error = create_rcom(ls, nodeid, DLM_RCOM_LOCK_REPLY,
 370                             sizeof(struct rcom_lock), &rc, &mh);
 371         if (error)
 372                 return;
 373
 374         /* We send back the same rcom_lock struct we received, but
 375            dlm_recover_master_copy() has filled in rl_remid and rl_result */
 376
 377         memcpy(rc->rc_buf, rc_in->rc_buf, sizeof(struct rcom_lock));
 378         rc->rc_id = rc_in->rc_id;
 379         rc->rc_seq_reply = rc_in->rc_seq;
 380
 381         send_rcom(ls, mh, rc);
 382 }
 383
 384 static void receive_rcom_lock_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
 385 {
 386         dlm_recover_process_copy(ls, rc_in);
 387 }
 388
 389 /* If the lockspace doesn't exist then still send a status message
 390    back; it's possible that it just doesn't have its global_id yet. */
 391
 392 int dlm_send_ls_not_ready(int nodeid, struct dlm_rcom *rc_in)
 393 {
 394         struct dlm_rcom *rc;
 395         struct rcom_config *rf;
 396         struct dlm_mhandle *mh;
 397         char *mb;
 398         int mb_len = sizeof(struct dlm_rcom) + sizeof(struct rcom_config);
 399
 400         mh = dlm_lowcomms_get_buffer(nodeid, mb_len, GFP_NOFS, &mb);
 401         if (!mh)
 402                 return -ENOBUFS;
 403         memset(mb, 0, mb_len);
 404
 405         rc = (struct dlm_rcom *) mb;
 406
 407         rc->rc_header.h_version = (DLM_HEADER_MAJOR | DLM_HEADER_MINOR);
 408         rc->rc_header.h_lockspace = rc_in->rc_header.h_lockspace;
 409         rc->rc_header.h_nodeid = dlm_our_nodeid();
 410         rc->rc_header.h_length = mb_len;
 411         rc->rc_header.h_cmd = DLM_RCOM;
 412
 413         rc->rc_type = DLM_RCOM_STATUS_REPLY;
 414         rc->rc_id = rc_in->rc_id;
 415         rc->rc_seq_reply = rc_in->rc_seq;
 416         rc->rc_result = -ESRCH;
 417
 418         rf = (struct rcom_config *) rc->rc_buf;
 419         rf->rf_lvblen = -1;
 420
 421         dlm_rcom_out(rc);
 422         dlm_lowcomms_commit_buffer(mh);
 423
 424         return 0;
 425 }
 426
 427 static int is_old_reply(struct dlm_ls *ls, struct dlm_rcom *rc)
 428 {
 429         uint64_t seq;
 430         int rv = 0;
 431
 432         switch (rc->rc_type) {
 433         case DLM_RCOM_STATUS_REPLY:
 434         case DLM_RCOM_NAMES_REPLY:
 435         case DLM_RCOM_LOOKUP_REPLY:
 436         case DLM_RCOM_LOCK_REPLY:
 437                 spin_lock(&ls->ls_recover_lock);
 438                 seq = ls->ls_recover_seq;
 439                 spin_unlock(&ls->ls_recover_lock);
 440                 if (rc->rc_seq_reply != seq) {
 441                         log_debug(ls, "ignoring old reply %x from %d "
 442                                       "seq_reply %llx expect %llx",
 443                                       rc->rc_type, rc->rc_header.h_nodeid,
 444                                       (unsigned long long)rc->rc_seq_reply,
 445                                       (unsigned long long)seq);
 446                         rv = 1;
 447                 }
 448         }
 449         return rv;
 450 }
 451
 452 /* Called by dlm_recv; corresponds to dlm_receive_message() but special
 453    recovery-only comms are sent through here. */
 454
 455 void dlm_receive_rcom(struct dlm_ls *ls, struct dlm_rcom *rc, int nodeid)
 456 {
 457         if (dlm_recovery_stopped(ls) && (rc->rc_type != DLM_RCOM_STATUS)) {
 458                 log_debug(ls, "ignoring recovery message %x from %d",
 459                           rc->rc_type, nodeid);
 460                 goto out;
 461         }
 462
 463         if (is_old_reply(ls, rc))
 464                 goto out;
 465
 466         switch (rc->rc_type) {
 467         case DLM_RCOM_STATUS:
 468                 receive_rcom_status(ls, rc);
 469                 break;
 470
 471         case DLM_RCOM_NAMES:
 472                 receive_rcom_names(ls, rc);
 473                 break;
 474
 475         case DLM_RCOM_LOOKUP:
 476                 receive_rcom_lookup(ls, rc);
 477                 break;
 478
 479         case DLM_RCOM_LOCK:
 480                 receive_rcom_lock(ls, rc);
 481                 break;
 482
 483         case DLM_RCOM_STATUS_REPLY:
 484                 receive_rcom_status_reply(ls, rc);
 485                 break;
 486
 487         case DLM_RCOM_NAMES_REPLY:
 488                 receive_rcom_names_reply(ls, rc);
 489                 break;
 490
 491         case DLM_RCOM_LOOKUP_REPLY:
 492                 receive_rcom_lookup_reply(ls, rc);
 493                 break;
 494
 495         case DLM_RCOM_LOCK_REPLY:
 496                 receive_rcom_lock_reply(ls, rc);
 497                 break;
 498
 499         default:
 500                 DLM_ASSERT(0, printk("rc_type=%x\n", rc->rc_type););
 501         }
 502  out:
 503         return;
 504 }
 505