kernel/fs/ocfs2/dlm/dlmconvert.c

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * dlmconvert.c
   5  *
   6  * underlying calls for lock conversion
   7  *
   8  * Copyright (C) 2004 Oracle.  All rights reserved.
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public
  12  * License as published by the Free Software Foundation; either
  13  * version 2 of the License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public
  21  * License along with this program; if not, write to the
  22  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23  * Boston, MA 021110-1307, USA.
  24  *
  25  */
  26
  27
  28 #include <linux/module.h>
  29 #include <linux/fs.h>
  30 #include <linux/types.h>
  31 #include <linux/highmem.h>
  32 #include <linux/init.h>
  33 #include <linux/sysctl.h>
  34 #include <linux/random.h>
  35 #include <linux/blkdev.h>
  36 #include <linux/socket.h>
  37 #include <linux/inet.h>
  38 #include <linux/spinlock.h>
  39
  40
  41 #include "cluster/heartbeat.h"
  42 #include "cluster/nodemanager.h"
  43 #include "cluster/tcp.h"
  44
  45 #include "dlmapi.h"
  46 #include "dlmcommon.h"
  47
  48 #include "dlmconvert.h"
  49
  50 #define MLOG_MASK_PREFIX ML_DLM
  51 #include "cluster/masklog.h"
  52
  53 /* NOTE: __dlmconvert_master is the only function in here that
  54  * needs a spinlock held on entry (res->spinlock) and it is the
  55  * only one that holds a lock on exit (res->spinlock).
  56  * All other functions in here need no locks and drop all of
  57  * the locks that they acquire. */
  58 static enum dlm_status __dlmconvert_master(struct dlm_ctxt *dlm,
  59                                            struct dlm_lock_resource *res,
  60                                            struct dlm_lock *lock, int flags,
  61                                            int type, int *call_ast,
  62                                            int *kick_thread);
  63 static enum dlm_status dlm_send_remote_convert_request(struct dlm_ctxt *dlm,
  64                                            struct dlm_lock_resource *res,
  65                                            struct dlm_lock *lock, int flags, int type);
  66
  67 /*
  68  * this is only called directly by dlmlock(), and only when the
  69  * local node is the owner of the lockres
  70  * locking:
  71  *   caller needs:  none
  72  *   taken:         takes and drops res->spinlock
  73  *   held on exit:  none
  74  * returns: see __dlmconvert_master
  75  */
  76 enum dlm_status dlmconvert_master(struct dlm_ctxt *dlm,
  77                                   struct dlm_lock_resource *res,
  78                                   struct dlm_lock *lock, int flags, int type)
  79 {
  80         int call_ast = 0, kick_thread = 0;
  81         enum dlm_status status;
  82
  83         spin_lock(&res->spinlock);
  84         /* we are not in a network handler, this is fine */
  85         __dlm_wait_on_lockres(res);
  86         __dlm_lockres_reserve_ast(res);
  87         res->state |= DLM_LOCK_RES_IN_PROGRESS;
  88
  89         status = __dlmconvert_master(dlm, res, lock, flags, type,
  90                                      &call_ast, &kick_thread);
  91
  92         res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
  93         spin_unlock(&res->spinlock);
  94         wake_up(&res->wq);
  95         if (status != DLM_NORMAL && status != DLM_NOTQUEUED)
  96                 dlm_error(status);
  97
  98         /* either queue the ast or release it */
  99         if (call_ast)
 100                 dlm_queue_ast(dlm, lock);
 101         else
 102                 dlm_lockres_release_ast(dlm, res);
 103
 104         if (kick_thread)
 105                 dlm_kick_thread(dlm, res);
 106
 107         return status;
 108 }
 109
 110 /* performs lock conversion at the lockres master site
 111  * locking:
 112  *   caller needs:  res->spinlock
 113  *   taken:         takes and drops lock->spinlock
 114  *   held on exit:  res->spinlock
 115  * returns: DLM_NORMAL, DLM_NOTQUEUED, DLM_DENIED
 116  *   call_ast: whether ast should be called for this lock
 117  *   kick_thread: whether dlm_kick_thread should be called
 118  */
 119 static enum dlm_status __dlmconvert_master(struct dlm_ctxt *dlm,
 120                                            struct dlm_lock_resource *res,
 121                                            struct dlm_lock *lock, int flags,
 122                                            int type, int *call_ast,
 123                                            int *kick_thread)
 124 {
 125         enum dlm_status status = DLM_NORMAL;
 126         struct dlm_lock *tmplock=NULL;
 127
 128         assert_spin_locked(&res->spinlock);
 129
 130         mlog(0, "type=%d, convert_type=%d, new convert_type=%d\n",
 131              lock->ml.type, lock->ml.convert_type, type);
 132
 133         spin_lock(&lock->spinlock);
 134
 135         /* already converting? */
 136         if (lock->ml.convert_type != LKM_IVMODE) {
 137                 mlog(ML_ERROR, "attempted to convert a lock with a lock "
 138                      "conversion pending\n");
 139                 status = DLM_DENIED;
 140                 goto unlock_exit;
 141         }
 142
 143         /* must be on grant queue to convert */
 144         if (!dlm_lock_on_list(&res->granted, lock)) {
 145                 mlog(ML_ERROR, "attempted to convert a lock not on grant "
 146                      "queue\n");
 147                 status = DLM_DENIED;
 148                 goto unlock_exit;
 149         }
 150
 151         if (flags & LKM_VALBLK) {
 152                 switch (lock->ml.type) {
 153                         case LKM_EXMODE:
 154                                 /* EX + LKM_VALBLK + convert == set lvb */
 155                                 mlog(0, "will set lvb: converting %s->%s\n",
 156                                      dlm_lock_mode_name(lock->ml.type),
 157                                      dlm_lock_mode_name(type));
 158                                 lock->lksb->flags |= DLM_LKSB_PUT_LVB;
 159                                 break;
 160                         case LKM_PRMODE:
 161                         case LKM_NLMODE:
 162                                 /* refetch if new level is not NL */
 163                                 if (type > LKM_NLMODE) {
 164                                         mlog(0, "will fetch new value into "
 165                                              "lvb: converting %s->%s\n",
 166                                              dlm_lock_mode_name(lock->ml.type),
 167                                              dlm_lock_mode_name(type));
 168                                         lock->lksb->flags |= DLM_LKSB_GET_LVB;
 169                                 } else {
 170                                         mlog(0, "will NOT fetch new value "
 171                                              "into lvb: converting %s->%s\n",
 172                                              dlm_lock_mode_name(lock->ml.type),
 173                                              dlm_lock_mode_name(type));
 174                                         flags &= ~(LKM_VALBLK);
 175                                 }
 176                                 break;
 177                 }
 178         }
 179
 180
 181         /* in-place downconvert? */
 182         if (type <= lock->ml.type)
 183                 goto grant;
 184
 185         /* upconvert from here on */
 186         status = DLM_NORMAL;
 187         list_for_each_entry(tmplock, &res->granted, list) {
 188                 if (tmplock == lock)
 189                         continue;
 190                 if (!dlm_lock_compatible(tmplock->ml.type, type))
 191                         goto switch_queues;
 192         }
 193
 194         list_for_each_entry(tmplock, &res->converting, list) {
 195                 if (!dlm_lock_compatible(tmplock->ml.type, type))
 196                         goto switch_queues;
 197                 /* existing conversion requests take precedence */
 198                 if (!dlm_lock_compatible(tmplock->ml.convert_type, type))
 199                         goto switch_queues;
 200         }
 201
 202         /* fall thru to grant */
 203
 204 grant:
 205         mlog(0, "res %.*s, granting %s lock\n", res->lockname.len,
 206              res->lockname.name, dlm_lock_mode_name(type));
 207         /* immediately grant the new lock type */
 208         lock->lksb->status = DLM_NORMAL;
 209         if (lock->ml.node == dlm->node_num)
 210                 mlog(0, "doing in-place convert for nonlocal lock\n");
 211         lock->ml.type = type;
 212         if (lock->lksb->flags & DLM_LKSB_PUT_LVB)
 213                 memcpy(res->lvb, lock->lksb->lvb, DLM_LVB_LEN);
 214
 215         status = DLM_NORMAL;
 216         *call_ast = 1;
 217         goto unlock_exit;
 218
 219 switch_queues:
 220         if (flags & LKM_NOQUEUE) {
 221                 mlog(0, "failed to convert NOQUEUE lock %.*s from "
 222                      "%d to %d...\n", res->lockname.len, res->lockname.name,
 223                      lock->ml.type, type);
 224                 status = DLM_NOTQUEUED;
 225                 goto unlock_exit;
 226         }
 227         mlog(0, "res %.*s, queueing...\n", res->lockname.len,
 228              res->lockname.name);
 229
 230         lock->ml.convert_type = type;
 231         /* do not alter lock refcount.  switching lists. */
 232         list_move_tail(&lock->list, &res->converting);
 233
 234 unlock_exit:
 235         spin_unlock(&lock->spinlock);
 236         if (status == DLM_DENIED) {
 237                 __dlm_print_one_lock_resource(res);
 238         }
 239         if (status == DLM_NORMAL)
 240                 *kick_thread = 1;
 241         return status;
 242 }
 243
 244 void dlm_revert_pending_convert(struct dlm_lock_resource *res,
 245                                 struct dlm_lock *lock)
 246 {
 247         /* do not alter lock refcount.  switching lists. */
 248         list_move_tail(&lock->list, &res->granted);
 249         lock->ml.convert_type = LKM_IVMODE;
 250         lock->lksb->flags &= ~(DLM_LKSB_GET_LVB|DLM_LKSB_PUT_LVB);
 251 }
 252
 253 /* messages the master site to do lock conversion
 254  * locking:
 255  *   caller needs:  none
 256  *   taken:         takes and drops res->spinlock, uses DLM_LOCK_RES_IN_PROGRESS
 257  *   held on exit:  none
 258  * returns: DLM_NORMAL, DLM_RECOVERING, status from remote node
 259  */
 260 enum dlm_status dlmconvert_remote(struct dlm_ctxt *dlm,
 261                                   struct dlm_lock_resource *res,
 262                                   struct dlm_lock *lock, int flags, int type)
 263 {
 264         enum dlm_status status;
 265
 266         mlog(0, "type=%d, convert_type=%d, busy=%d\n", lock->ml.type,
 267              lock->ml.convert_type, res->state & DLM_LOCK_RES_IN_PROGRESS);
 268
 269         spin_lock(&res->spinlock);
 270         if (res->state & DLM_LOCK_RES_RECOVERING) {
 271                 mlog(0, "bailing out early since res is RECOVERING "
 272                      "on secondary queue\n");
 273                 /* __dlm_print_one_lock_resource(res); */
 274                 status = DLM_RECOVERING;
 275                 goto bail;
 276         }
 277         /* will exit this call with spinlock held */
 278         __dlm_wait_on_lockres(res);
 279
 280         if (lock->ml.convert_type != LKM_IVMODE) {
 281                 __dlm_print_one_lock_resource(res);
 282                 mlog(ML_ERROR, "converting a remote lock that is already "
 283                      "converting! (cookie=%u:%llu, conv=%d)\n",
 284                      dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
 285                      dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
 286                      lock->ml.convert_type);
 287                 status = DLM_DENIED;
 288                 goto bail;
 289         }
 290
 291         if (lock->ml.type == type && lock->ml.convert_type == LKM_IVMODE) {
 292                 mlog(0, "last convert request returned DLM_RECOVERING, but "
 293                      "owner has already queued and sent ast to me. res %.*s, "
 294                      "(cookie=%u:%llu, type=%d, conv=%d)\n",
 295                      res->lockname.len, res->lockname.name,
 296                      dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
 297                      dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
 298                      lock->ml.type, lock->ml.convert_type);
 299                 status = DLM_NORMAL;
 300                 goto bail;
 301         }
 302
 303         res->state |= DLM_LOCK_RES_IN_PROGRESS;
 304         /* move lock to local convert queue */
 305         /* do not alter lock refcount.  switching lists. */
 306         list_move_tail(&lock->list, &res->converting);
 307         lock->convert_pending = 1;
 308         lock->ml.convert_type = type;
 309
 310         if (flags & LKM_VALBLK) {
 311                 if (lock->ml.type == LKM_EXMODE) {
 312                         flags |= LKM_PUT_LVB;
 313                         lock->lksb->flags |= DLM_LKSB_PUT_LVB;
 314                 } else {
 315                         if (lock->ml.convert_type == LKM_NLMODE)
 316                                 flags &= ~LKM_VALBLK;
 317                         else {
 318                                 flags |= LKM_GET_LVB;
 319                                 lock->lksb->flags |= DLM_LKSB_GET_LVB;
 320                         }
 321                 }
 322         }
 323         spin_unlock(&res->spinlock);
 324
 325         /* no locks held here.
 326          * need to wait for a reply as to whether it got queued or not. */
 327         status = dlm_send_remote_convert_request(dlm, res, lock, flags, type);
 328
 329         spin_lock(&res->spinlock);
 330         res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
 331         /* if it failed, move it back to granted queue.
 332          * if master returns DLM_NORMAL and then down before sending ast,
 333          * it may have already been moved to granted queue, reset to
 334          * DLM_RECOVERING and retry convert */
 335         if (status != DLM_NORMAL) {
 336                 if (status != DLM_NOTQUEUED)
 337                         dlm_error(status);
 338                 dlm_revert_pending_convert(res, lock);
 339         } else if (!lock->convert_pending) {
 340                 mlog(0, "%s: res %.*s, owner died and lock has been moved back "
 341                                 "to granted list, retry convert.\n",
 342                                 dlm->name, res->lockname.len, res->lockname.name);
 343                 status = DLM_RECOVERING;
 344         }
 345
 346         lock->convert_pending = 0;
 347 bail:
 348         spin_unlock(&res->spinlock);
 349
 350         /* TODO: should this be a wake_one? */
 351         /* wake up any IN_PROGRESS waiters */
 352         wake_up(&res->wq);
 353
 354         return status;
 355 }
 356
 357 /* sends DLM_CONVERT_LOCK_MSG to master site
 358  * locking:
 359  *   caller needs:  none
 360  *   taken:         none
 361  *   held on exit:  none
 362  * returns: DLM_NOLOCKMGR, status from remote node
 363  */
 364 static enum dlm_status dlm_send_remote_convert_request(struct dlm_ctxt *dlm,
 365                                            struct dlm_lock_resource *res,
 366                                            struct dlm_lock *lock, int flags, int type)
 367 {
 368         struct dlm_convert_lock convert;
 369         int tmpret;
 370         enum dlm_status ret;
 371         int status = 0;
 372         struct kvec vec[2];
 373         size_t veclen = 1;
 374
 375         mlog(0, "%.*s\n", res->lockname.len, res->lockname.name);
 376
 377         memset(&convert, 0, sizeof(struct dlm_convert_lock));
 378         convert.node_idx = dlm->node_num;
 379         convert.requested_type = type;
 380         convert.cookie = lock->ml.cookie;
 381         convert.namelen = res->lockname.len;
 382         convert.flags = cpu_to_be32(flags);
 383         memcpy(convert.name, res->lockname.name, convert.namelen);
 384
 385         vec[0].iov_len = sizeof(struct dlm_convert_lock);
 386         vec[0].iov_base = &convert;
 387
 388         if (flags & LKM_PUT_LVB) {
 389                 /* extra data to send if we are updating lvb */
 390                 vec[1].iov_len = DLM_LVB_LEN;
 391                 vec[1].iov_base = lock->lksb->lvb;
 392                 veclen++;
 393         }
 394
 395         tmpret = o2net_send_message_vec(DLM_CONVERT_LOCK_MSG, dlm->key,
 396                                         vec, veclen, res->owner, &status);
 397         if (tmpret >= 0) {
 398                 // successfully sent and received
 399                 ret = status;  // this is already a dlm_status
 400                 if (ret == DLM_RECOVERING) {
 401                         mlog(0, "node %u returned DLM_RECOVERING from convert "
 402                              "message!\n", res->owner);
 403                 } else if (ret == DLM_MIGRATING) {
 404                         mlog(0, "node %u returned DLM_MIGRATING from convert "
 405                              "message!\n", res->owner);
 406                 } else if (ret == DLM_FORWARD) {
 407                         mlog(0, "node %u returned DLM_FORWARD from convert "
 408                              "message!\n", res->owner);
 409                 } else if (ret != DLM_NORMAL && ret != DLM_NOTQUEUED)
 410                         dlm_error(ret);
 411         } else {
 412                 mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
 413                      "node %u\n", tmpret, DLM_CONVERT_LOCK_MSG, dlm->key,
 414                      res->owner);
 415                 if (dlm_is_host_down(tmpret)) {
 416                         /* instead of logging the same network error over
 417                          * and over, sleep here and wait for the heartbeat
 418                          * to notice the node is dead.  times out after 5s. */
 419                         dlm_wait_for_node_death(dlm, res->owner,
 420                                                 DLM_NODE_DEATH_WAIT_MAX);
 421                         ret = DLM_RECOVERING;
 422                         mlog(0, "node %u died so returning DLM_RECOVERING "
 423                              "from convert message!\n", res->owner);
 424                 } else {
 425                         ret = dlm_err_to_dlm_status(tmpret);
 426                 }
 427         }
 428
 429         return ret;
 430 }
 431
 432 /* handler for DLM_CONVERT_LOCK_MSG on master site
 433  * locking:
 434  *   caller needs:  none
 435  *   taken:         takes and drop res->spinlock
 436  *   held on exit:  none
 437  * returns: DLM_NORMAL, DLM_IVLOCKID, DLM_BADARGS,
 438  *          status from __dlmconvert_master
 439  */
 440 int dlm_convert_lock_handler(struct o2net_msg *msg, u32 len, void *data,
 441                              void **ret_data)
 442 {
 443         struct dlm_ctxt *dlm = data;
 444         struct dlm_convert_lock *cnv = (struct dlm_convert_lock *)msg->buf;
 445         struct dlm_lock_resource *res = NULL;
 446         struct dlm_lock *lock = NULL;
 447         struct dlm_lock *tmp_lock;
 448         struct dlm_lockstatus *lksb;
 449         enum dlm_status status = DLM_NORMAL;
 450         u32 flags;
 451         int call_ast = 0, kick_thread = 0, ast_reserved = 0, wake = 0;
 452
 453         if (!dlm_grab(dlm)) {
 454                 dlm_error(DLM_REJECTED);
 455                 return DLM_REJECTED;
 456         }
 457
 458         mlog_bug_on_msg(!dlm_domain_fully_joined(dlm),
 459                         "Domain %s not fully joined!\n", dlm->name);
 460
 461         if (cnv->namelen > DLM_LOCKID_NAME_MAX) {
 462                 status = DLM_IVBUFLEN;
 463                 dlm_error(status);
 464                 goto leave;
 465         }
 466
 467         flags = be32_to_cpu(cnv->flags);
 468
 469         if ((flags & (LKM_PUT_LVB|LKM_GET_LVB)) ==
 470              (LKM_PUT_LVB|LKM_GET_LVB)) {
 471                 mlog(ML_ERROR, "both PUT and GET lvb specified\n");
 472                 status = DLM_BADARGS;
 473                 goto leave;
 474         }
 475
 476         mlog(0, "lvb: %s\n", flags & LKM_PUT_LVB ? "put lvb" :
 477              (flags & LKM_GET_LVB ? "get lvb" : "none"));
 478
 479         status = DLM_IVLOCKID;
 480         res = dlm_lookup_lockres(dlm, cnv->name, cnv->namelen);
 481         if (!res) {
 482                 dlm_error(status);
 483                 goto leave;
 484         }
 485
 486         spin_lock(&res->spinlock);
 487         status = __dlm_lockres_state_to_status(res);
 488         if (status != DLM_NORMAL) {
 489                 spin_unlock(&res->spinlock);
 490                 dlm_error(status);
 491                 goto leave;
 492         }
 493         list_for_each_entry(tmp_lock, &res->granted, list) {
 494                 if (tmp_lock->ml.cookie == cnv->cookie &&
 495                     tmp_lock->ml.node == cnv->node_idx) {
 496                         lock = tmp_lock;
 497                         dlm_lock_get(lock);
 498                         break;
 499                 }
 500         }
 501         spin_unlock(&res->spinlock);
 502         if (!lock) {
 503                 status = DLM_IVLOCKID;
 504                 mlog(ML_ERROR, "did not find lock to convert on grant queue! "
 505                                "cookie=%u:%llu\n",
 506                      dlm_get_lock_cookie_node(be64_to_cpu(cnv->cookie)),
 507                      dlm_get_lock_cookie_seq(be64_to_cpu(cnv->cookie)));
 508                 dlm_print_one_lock_resource(res);
 509                 goto leave;
 510         }
 511
 512         /* found the lock */
 513         lksb = lock->lksb;
 514
 515         /* see if caller needed to get/put lvb */
 516         if (flags & LKM_PUT_LVB) {
 517                 BUG_ON(lksb->flags & (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
 518                 lksb->flags |= DLM_LKSB_PUT_LVB;
 519                 memcpy(&lksb->lvb[0], &cnv->lvb[0], DLM_LVB_LEN);
 520         } else if (flags & LKM_GET_LVB) {
 521                 BUG_ON(lksb->flags & (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
 522                 lksb->flags |= DLM_LKSB_GET_LVB;
 523         }
 524
 525         spin_lock(&res->spinlock);
 526         status = __dlm_lockres_state_to_status(res);
 527         if (status == DLM_NORMAL) {
 528                 __dlm_lockres_reserve_ast(res);
 529                 ast_reserved = 1;
 530                 res->state |= DLM_LOCK_RES_IN_PROGRESS;
 531                 status = __dlmconvert_master(dlm, res, lock, flags,
 532                                              cnv->requested_type,
 533                                              &call_ast, &kick_thread);
 534                 res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
 535                 wake = 1;
 536         }
 537         spin_unlock(&res->spinlock);
 538         if (wake)
 539                 wake_up(&res->wq);
 540
 541         if (status != DLM_NORMAL) {
 542                 if (status != DLM_NOTQUEUED)
 543                         dlm_error(status);
 544                 lksb->flags &= ~(DLM_LKSB_GET_LVB|DLM_LKSB_PUT_LVB);
 545         }
 546
 547 leave:
 548         if (lock)
 549                 dlm_lock_put(lock);
 550
 551         /* either queue the ast or release it, if reserved */
 552         if (call_ast)
 553                 dlm_queue_ast(dlm, lock);
 554         else if (ast_reserved)
 555                 dlm_lockres_release_ast(dlm, res);
 556
 557         if (kick_thread)
 558                 dlm_kick_thread(dlm, res);
 559
 560         if (res)
 561                 dlm_lockres_put(res);
 562
 563         dlm_put(dlm);
 564
 565         return status;
 566 }