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