err.no Git - linux-2.6/blob - fs/ocfs2/dlm/dlmlock.c

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * dlmlock.c
   5  *
   6  * underlying calls for lock creation
   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/utsname.h>
  34 #include <linux/init.h>
  35 #include <linux/sysctl.h>
  36 #include <linux/random.h>
  37 #include <linux/blkdev.h>
  38 #include <linux/socket.h>
  39 #include <linux/inet.h>
  40 #include <linux/spinlock.h>
  41 #include <linux/delay.h>
  42
  43
  44 #include "cluster/heartbeat.h"
  45 #include "cluster/nodemanager.h"
  46 #include "cluster/tcp.h"
  47
  48 #include "dlmapi.h"
  49 #include "dlmcommon.h"
  50
  51 #include "dlmconvert.h"
  52
  53 #define MLOG_MASK_PREFIX ML_DLM
  54 #include "cluster/masklog.h"
  55
  56 static spinlock_t dlm_cookie_lock = SPIN_LOCK_UNLOCKED;
  57 static u64 dlm_next_cookie = 1;
  58
  59 static enum dlm_status dlm_send_remote_lock_request(struct dlm_ctxt *dlm,
  60                                                struct dlm_lock_resource *res,
  61                                                struct dlm_lock *lock, int flags);
  62 static void dlm_init_lock(struct dlm_lock *newlock, int type,
  63                           u8 node, u64 cookie);
  64 static void dlm_lock_release(struct kref *kref);
  65 static void dlm_lock_detach_lockres(struct dlm_lock *lock);
  66
  67 /* Tell us whether we can grant a new lock request.
  68  * locking:
  69  *   caller needs:  res->spinlock
  70  *   taken:         none
  71  *   held on exit:  none
  72  * returns: 1 if the lock can be granted, 0 otherwise.
  73  */
  74 static int dlm_can_grant_new_lock(struct dlm_lock_resource *res,
  75                                   struct dlm_lock *lock)
  76 {
  77         struct list_head *iter;
  78         struct dlm_lock *tmplock;
  79
  80         list_for_each(iter, &res->granted) {
  81                 tmplock = list_entry(iter, struct dlm_lock, list);
  82
  83                 if (!dlm_lock_compatible(tmplock->ml.type, lock->ml.type))
  84                         return 0;
  85         }
  86
  87         list_for_each(iter, &res->converting) {
  88                 tmplock = list_entry(iter, struct dlm_lock, list);
  89
  90                 if (!dlm_lock_compatible(tmplock->ml.type, lock->ml.type))
  91                         return 0;
  92         }
  93
  94         return 1;
  95 }
  96
  97 /* performs lock creation at the lockres master site
  98  * locking:
  99  *   caller needs:  none
 100  *   taken:         takes and drops res->spinlock
 101  *   held on exit:  none
 102  * returns: DLM_NORMAL, DLM_NOTQUEUED
 103  */
 104 static enum dlm_status dlmlock_master(struct dlm_ctxt *dlm,
 105                                       struct dlm_lock_resource *res,
 106                                       struct dlm_lock *lock, int flags)
 107 {
 108         int call_ast = 0, kick_thread = 0;
 109         enum dlm_status status = DLM_NORMAL;
 110
 111         mlog_entry("type=%d\n", lock->ml.type);
 112
 113         spin_lock(&res->spinlock);
 114         /* if called from dlm_create_lock_handler, need to
 115          * ensure it will not sleep in dlm_wait_on_lockres */
 116         status = __dlm_lockres_state_to_status(res);
 117         if (status != DLM_NORMAL &&
 118             lock->ml.node != dlm->node_num) {
 119                 /* erf.  state changed after lock was dropped. */
 120                 spin_unlock(&res->spinlock);
 121                 dlm_error(status);
 122                 return status;
 123         }
 124         __dlm_wait_on_lockres(res);
 125         __dlm_lockres_reserve_ast(res);
 126
 127         if (dlm_can_grant_new_lock(res, lock)) {
 128                 mlog(0, "I can grant this lock right away\n");
 129                 /* got it right away */
 130                 lock->lksb->status = DLM_NORMAL;
 131                 status = DLM_NORMAL;
 132                 dlm_lock_get(lock);
 133                 list_add_tail(&lock->list, &res->granted);
 134
 135                 /* for the recovery lock, we can't allow the ast
 136                  * to be queued since the dlmthread is already
 137                  * frozen.  but the recovery lock is always locked
 138                  * with LKM_NOQUEUE so we do not need the ast in
 139                  * this special case */
 140                 if (!dlm_is_recovery_lock(res->lockname.name,
 141                                           res->lockname.len)) {
 142                         kick_thread = 1;
 143                         call_ast = 1;
 144                 } else {
 145                         mlog(0, "%s: returning DLM_NORMAL to "
 146                              "node %u for reco lock\n", dlm->name,
 147                              lock->ml.node);
 148                 }
 149         } else {
 150                 /* for NOQUEUE request, unless we get the
 151                  * lock right away, return DLM_NOTQUEUED */
 152                 if (flags & LKM_NOQUEUE) {
 153                         status = DLM_NOTQUEUED;
 154                         if (dlm_is_recovery_lock(res->lockname.name,
 155                                                  res->lockname.len)) {
 156                                 mlog(0, "%s: returning NOTQUEUED to "
 157                                      "node %u for reco lock\n", dlm->name,
 158                                      lock->ml.node);
 159                         }
 160                 } else {
 161                         dlm_lock_get(lock);
 162                         list_add_tail(&lock->list, &res->blocked);
 163                         kick_thread = 1;
 164                 }
 165         }
 166
 167         spin_unlock(&res->spinlock);
 168         wake_up(&res->wq);
 169
 170         /* either queue the ast or release it */
 171         if (call_ast)
 172                 dlm_queue_ast(dlm, lock);
 173         else
 174                 dlm_lockres_release_ast(dlm, res);
 175
 176         dlm_lockres_calc_usage(dlm, res);
 177         if (kick_thread)
 178                 dlm_kick_thread(dlm, res);
 179
 180         return status;
 181 }
 182
 183 void dlm_revert_pending_lock(struct dlm_lock_resource *res,
 184                              struct dlm_lock *lock)
 185 {
 186         /* remove from local queue if it failed */
 187         list_del_init(&lock->list);
 188         lock->lksb->flags &= ~DLM_LKSB_GET_LVB;
 189 }
 190
 191
 192 /*
 193  * locking:
 194  *   caller needs:  none
 195  *   taken:         takes and drops res->spinlock
 196  *   held on exit:  none
 197  * returns: DLM_DENIED, DLM_RECOVERING, or net status
 198  */
 199 static enum dlm_status dlmlock_remote(struct dlm_ctxt *dlm,
 200                                       struct dlm_lock_resource *res,
 201                                       struct dlm_lock *lock, int flags)
 202 {
 203         enum dlm_status status = DLM_DENIED;
 204         int lockres_changed = 1;
 205
 206         mlog_entry("type=%d\n", lock->ml.type);
 207         mlog(0, "lockres %.*s, flags = 0x%x\n", res->lockname.len,
 208              res->lockname.name, flags);
 209
 210         spin_lock(&res->spinlock);
 211
 212         /* will exit this call with spinlock held */
 213         __dlm_wait_on_lockres(res);
 214         res->state |= DLM_LOCK_RES_IN_PROGRESS;
 215
 216         /* add lock to local (secondary) queue */
 217         dlm_lock_get(lock);
 218         list_add_tail(&lock->list, &res->blocked);
 219         lock->lock_pending = 1;
 220         spin_unlock(&res->spinlock);
 221
 222         /* spec seems to say that you will get DLM_NORMAL when the lock
 223          * has been queued, meaning we need to wait for a reply here. */
 224         status = dlm_send_remote_lock_request(dlm, res, lock, flags);
 225
 226         spin_lock(&res->spinlock);
 227         res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
 228         lock->lock_pending = 0;
 229         if (status != DLM_NORMAL) {
 230                 if (status != DLM_NOTQUEUED) {
 231                         /*
 232                          * DO NOT call calc_usage, as this would unhash
 233                          * the remote lockres before we ever get to use
 234                          * it.  treat as if we never made any change to
 235                          * the lockres.
 236                          */
 237                         lockres_changed = 0;
 238                         dlm_error(status);
 239                 }
 240                 dlm_revert_pending_lock(res, lock);
 241                 dlm_lock_put(lock);
 242         } else if (dlm_is_recovery_lock(res->lockname.name,
 243                                         res->lockname.len)) {
 244                 /* special case for the $RECOVERY lock.
 245                  * there will never be an AST delivered to put
 246                  * this lock on the proper secondary queue
 247                  * (granted), so do it manually. */
 248                 mlog(0, "%s: $RECOVERY lock for this node (%u) is "
 249                      "mastered by %u; got lock, manually granting (no ast)\n",
 250                      dlm->name, dlm->node_num, res->owner);
 251                 list_move_tail(&lock->list, &res->granted);
 252         }
 253         spin_unlock(&res->spinlock);
 254
 255         if (lockres_changed)
 256                 dlm_lockres_calc_usage(dlm, res);
 257
 258         wake_up(&res->wq);
 259         return status;
 260 }
 261
 262
 263 /* for remote lock creation.
 264  * locking:
 265  *   caller needs:  none, but need res->state & DLM_LOCK_RES_IN_PROGRESS
 266  *   taken:         none
 267  *   held on exit:  none
 268  * returns: DLM_NOLOCKMGR, or net status
 269  */
 270 static enum dlm_status dlm_send_remote_lock_request(struct dlm_ctxt *dlm,
 271                                                struct dlm_lock_resource *res,
 272                                                struct dlm_lock *lock, int flags)
 273 {
 274         struct dlm_create_lock create;
 275         int tmpret, status = 0;
 276         enum dlm_status ret;
 277
 278         mlog_entry_void();
 279
 280         memset(&create, 0, sizeof(create));
 281         create.node_idx = dlm->node_num;
 282         create.requested_type = lock->ml.type;
 283         create.cookie = lock->ml.cookie;
 284         create.namelen = res->lockname.len;
 285         create.flags = cpu_to_be32(flags);
 286         memcpy(create.name, res->lockname.name, create.namelen);
 287
 288         tmpret = o2net_send_message(DLM_CREATE_LOCK_MSG, dlm->key, &create,
 289                                     sizeof(create), res->owner, &status);
 290         if (tmpret >= 0) {
 291                 // successfully sent and received
 292                 ret = status;  // this is already a dlm_status
 293                 if (ret == DLM_RECOVERING) {
 294                         mlog(ML_ERROR, "%s:%.*s: BUG.  this is a stale lockres "
 295                              "no longer owned by %u.  that node is coming back "
 296                              "up currently.\n", dlm->name, create.namelen,
 297                              create.name, res->owner);
 298                         dlm_print_one_lock_resource(res);
 299                         BUG();
 300                 }
 301         } else {
 302                 mlog_errno(tmpret);
 303                 if (dlm_is_host_down(tmpret)) {
 304                         ret = DLM_RECOVERING;
 305                         mlog(0, "node %u died so returning DLM_RECOVERING "
 306                              "from lock message!\n", res->owner);
 307                 } else {
 308                         ret = dlm_err_to_dlm_status(tmpret);
 309                 }
 310         }
 311
 312         return ret;
 313 }
 314
 315 void dlm_lock_get(struct dlm_lock *lock)
 316 {
 317         kref_get(&lock->lock_refs);
 318 }
 319
 320 void dlm_lock_put(struct dlm_lock *lock)
 321 {
 322         kref_put(&lock->lock_refs, dlm_lock_release);
 323 }
 324
 325 static void dlm_lock_release(struct kref *kref)
 326 {
 327         struct dlm_lock *lock;
 328
 329         lock = container_of(kref, struct dlm_lock, lock_refs);
 330
 331         BUG_ON(!list_empty(&lock->list));
 332         BUG_ON(!list_empty(&lock->ast_list));
 333         BUG_ON(!list_empty(&lock->bast_list));
 334         BUG_ON(lock->ast_pending);
 335         BUG_ON(lock->bast_pending);
 336
 337         dlm_lock_detach_lockres(lock);
 338
 339         if (lock->lksb_kernel_allocated) {
 340                 mlog(0, "freeing kernel-allocated lksb\n");
 341                 kfree(lock->lksb);
 342         }
 343         kfree(lock);
 344 }
 345
 346 /* associate a lock with it's lockres, getting a ref on the lockres */
 347 void dlm_lock_attach_lockres(struct dlm_lock *lock,
 348                              struct dlm_lock_resource *res)
 349 {
 350         dlm_lockres_get(res);
 351         lock->lockres = res;
 352 }
 353
 354 /* drop ref on lockres, if there is still one associated with lock */
 355 static void dlm_lock_detach_lockres(struct dlm_lock *lock)
 356 {
 357         struct dlm_lock_resource *res;
 358
 359         res = lock->lockres;
 360         if (res) {
 361                 lock->lockres = NULL;
 362                 mlog(0, "removing lock's lockres reference\n");
 363                 dlm_lockres_put(res);
 364         }
 365 }
 366
 367 static void dlm_init_lock(struct dlm_lock *newlock, int type,
 368                           u8 node, u64 cookie)
 369 {
 370         INIT_LIST_HEAD(&newlock->list);
 371         INIT_LIST_HEAD(&newlock->ast_list);
 372         INIT_LIST_HEAD(&newlock->bast_list);
 373         spin_lock_init(&newlock->spinlock);
 374         newlock->ml.type = type;
 375         newlock->ml.convert_type = LKM_IVMODE;
 376         newlock->ml.highest_blocked = LKM_IVMODE;
 377         newlock->ml.node = node;
 378         newlock->ml.pad1 = 0;
 379         newlock->ml.list = 0;
 380         newlock->ml.flags = 0;
 381         newlock->ast = NULL;
 382         newlock->bast = NULL;
 383         newlock->astdata = NULL;
 384         newlock->ml.cookie = cpu_to_be64(cookie);
 385         newlock->ast_pending = 0;
 386         newlock->bast_pending = 0;
 387         newlock->convert_pending = 0;
 388         newlock->lock_pending = 0;
 389         newlock->unlock_pending = 0;
 390         newlock->cancel_pending = 0;
 391         newlock->lksb_kernel_allocated = 0;
 392
 393         kref_init(&newlock->lock_refs);
 394 }
 395
 396 struct dlm_lock * dlm_new_lock(int type, u8 node, u64 cookie,
 397                                struct dlm_lockstatus *lksb)
 398 {
 399         struct dlm_lock *lock;
 400         int kernel_allocated = 0;
 401
 402         lock = kcalloc(1, sizeof(*lock), GFP_KERNEL);
 403         if (!lock)
 404                 return NULL;
 405
 406         if (!lksb) {
 407                 /* zero memory only if kernel-allocated */
 408                 lksb = kcalloc(1, sizeof(*lksb), GFP_KERNEL);
 409                 if (!lksb) {
 410                         kfree(lock);
 411                         return NULL;
 412                 }
 413                 kernel_allocated = 1;
 414         }
 415
 416         dlm_init_lock(lock, type, node, cookie);
 417         if (kernel_allocated)
 418                 lock->lksb_kernel_allocated = 1;
 419         lock->lksb = lksb;
 420         lksb->lockid = lock;
 421         return lock;
 422 }
 423
 424 /* handler for lock creation net message
 425  * locking:
 426  *   caller needs:  none
 427  *   taken:         takes and drops res->spinlock
 428  *   held on exit:  none
 429  * returns: DLM_NORMAL, DLM_SYSERR, DLM_IVLOCKID, DLM_NOTQUEUED
 430  */
 431 int dlm_create_lock_handler(struct o2net_msg *msg, u32 len, void *data)
 432 {
 433         struct dlm_ctxt *dlm = data;
 434         struct dlm_create_lock *create = (struct dlm_create_lock *)msg->buf;
 435         struct dlm_lock_resource *res = NULL;
 436         struct dlm_lock *newlock = NULL;
 437         struct dlm_lockstatus *lksb = NULL;
 438         enum dlm_status status = DLM_NORMAL;
 439         char *name;
 440         unsigned int namelen;
 441
 442         BUG_ON(!dlm);
 443
 444         mlog_entry_void();
 445
 446         if (!dlm_grab(dlm))
 447                 return DLM_REJECTED;
 448
 449         name = create->name;
 450         namelen = create->namelen;
 451         status = DLM_RECOVERING;
 452         if (!dlm_domain_fully_joined(dlm)) {
 453                 mlog(ML_ERROR, "Domain %s not fully joined, but node %u is "
 454                      "sending a create_lock message for lock %.*s!\n",
 455                      dlm->name, create->node_idx, namelen, name);
 456                 dlm_error(status);
 457                 goto leave;
 458         }
 459
 460         status = DLM_IVBUFLEN;
 461         if (namelen > DLM_LOCKID_NAME_MAX) {
 462                 dlm_error(status);
 463                 goto leave;
 464         }
 465
 466         status = DLM_SYSERR;
 467         newlock = dlm_new_lock(create->requested_type,
 468                                create->node_idx,
 469                                be64_to_cpu(create->cookie), NULL);
 470         if (!newlock) {
 471                 dlm_error(status);
 472                 goto leave;
 473         }
 474
 475         lksb = newlock->lksb;
 476
 477         if (be32_to_cpu(create->flags) & LKM_GET_LVB) {
 478                 lksb->flags |= DLM_LKSB_GET_LVB;
 479                 mlog(0, "set DLM_LKSB_GET_LVB flag\n");
 480         }
 481
 482         status = DLM_IVLOCKID;
 483         res = dlm_lookup_lockres(dlm, name, namelen);
 484         if (!res) {
 485                 dlm_error(status);
 486                 goto leave;
 487         }
 488
 489         spin_lock(&res->spinlock);
 490         status = __dlm_lockres_state_to_status(res);
 491         spin_unlock(&res->spinlock);
 492
 493         if (status != DLM_NORMAL) {
 494                 mlog(0, "lockres recovering/migrating/in-progress\n");
 495                 goto leave;
 496         }
 497
 498         dlm_lock_attach_lockres(newlock, res);
 499
 500         status = dlmlock_master(dlm, res, newlock, be32_to_cpu(create->flags));
 501 leave:
 502         if (status != DLM_NORMAL)
 503                 if (newlock)
 504                         dlm_lock_put(newlock);
 505
 506         if (res)
 507                 dlm_lockres_put(res);
 508
 509         dlm_put(dlm);
 510
 511         return status;
 512 }
 513
 514
 515 /* fetch next node-local (u8 nodenum + u56 cookie) into u64 */
 516 static inline void dlm_get_next_cookie(u8 node_num, u64 *cookie)
 517 {
 518         u64 tmpnode = node_num;
 519
 520         /* shift single byte of node num into top 8 bits */
 521         tmpnode <<= 56;
 522
 523         spin_lock(&dlm_cookie_lock);
 524         *cookie = (dlm_next_cookie | tmpnode);
 525         if (++dlm_next_cookie & 0xff00000000000000ull) {
 526                 mlog(0, "This node's cookie will now wrap!\n");
 527                 dlm_next_cookie = 1;
 528         }
 529         spin_unlock(&dlm_cookie_lock);
 530 }
 531
 532 enum dlm_status dlmlock(struct dlm_ctxt *dlm, int mode,
 533                         struct dlm_lockstatus *lksb, int flags,
 534                         const char *name, dlm_astlockfunc_t *ast, void *data,
 535                         dlm_bastlockfunc_t *bast)
 536 {
 537         enum dlm_status status;
 538         struct dlm_lock_resource *res = NULL;
 539         struct dlm_lock *lock = NULL;
 540         int convert = 0, recovery = 0;
 541
 542         /* yes this function is a mess.
 543          * TODO: clean this up.  lots of common code in the
 544          *       lock and convert paths, especially in the retry blocks */
 545         if (!lksb) {
 546                 dlm_error(DLM_BADARGS);
 547                 return DLM_BADARGS;
 548         }
 549
 550         status = DLM_BADPARAM;
 551         if (mode != LKM_EXMODE && mode != LKM_PRMODE && mode != LKM_NLMODE) {
 552                 dlm_error(status);
 553                 goto error;
 554         }
 555
 556         if (flags & ~LKM_VALID_FLAGS) {
 557                 dlm_error(status);
 558                 goto error;
 559         }
 560
 561         convert = (flags & LKM_CONVERT);
 562         recovery = (flags & LKM_RECOVERY);
 563
 564         if (recovery &&
 565             (!dlm_is_recovery_lock(name, strlen(name)) || convert) ) {
 566                 dlm_error(status);
 567                 goto error;
 568         }
 569         if (convert && (flags & LKM_LOCAL)) {
 570                 mlog(ML_ERROR, "strange LOCAL convert request!\n");
 571                 goto error;
 572         }
 573
 574         if (convert) {
 575                 /* CONVERT request */
 576
 577                 /* if converting, must pass in a valid dlm_lock */
 578                 lock = lksb->lockid;
 579                 if (!lock) {
 580                         mlog(ML_ERROR, "NULL lock pointer in convert "
 581                              "request\n");
 582                         goto error;
 583                 }
 584
 585                 res = lock->lockres;
 586                 if (!res) {
 587                         mlog(ML_ERROR, "NULL lockres pointer in convert "
 588                              "request\n");
 589                         goto error;
 590                 }
 591                 dlm_lockres_get(res);
 592
 593                 /* XXX: for ocfs2 purposes, the ast/bast/astdata/lksb are
 594                  * static after the original lock call.  convert requests will
 595                  * ensure that everything is the same, or return DLM_BADARGS.
 596                  * this means that DLM_DENIED_NOASTS will never be returned.
 597                  */
 598                 if (lock->lksb != lksb || lock->ast != ast ||
 599                     lock->bast != bast || lock->astdata != data) {
 600                         status = DLM_BADARGS;
 601                         mlog(ML_ERROR, "new args:  lksb=%p, ast=%p, bast=%p, "
 602                              "astdata=%p\n", lksb, ast, bast, data);
 603                         mlog(ML_ERROR, "orig args: lksb=%p, ast=%p, bast=%p, "
 604                              "astdata=%p\n", lock->lksb, lock->ast,
 605                              lock->bast, lock->astdata);
 606                         goto error;
 607                 }
 608 retry_convert:
 609                 dlm_wait_for_recovery(dlm);
 610
 611                 if (res->owner == dlm->node_num)
 612                         status = dlmconvert_master(dlm, res, lock, flags, mode);
 613                 else
 614                         status = dlmconvert_remote(dlm, res, lock, flags, mode);
 615                 if (status == DLM_RECOVERING || status == DLM_MIGRATING ||
 616                     status == DLM_FORWARD) {
 617                         /* for now, see how this works without sleeping
 618                          * and just retry right away.  I suspect the reco
 619                          * or migration will complete fast enough that
 620                          * no waiting will be necessary */
 621                         mlog(0, "retrying convert with migration/recovery/"
 622                              "in-progress\n");
 623                         msleep(100);
 624                         goto retry_convert;
 625                 }
 626         } else {
 627                 u64 tmpcookie;
 628
 629                 /* LOCK request */
 630                 status = DLM_BADARGS;
 631                 if (!name) {
 632                         dlm_error(status);
 633                         goto error;
 634                 }
 635
 636                 status = DLM_IVBUFLEN;
 637                 if (strlen(name) > DLM_LOCKID_NAME_MAX || strlen(name) < 1) {
 638                         dlm_error(status);
 639                         goto error;
 640                 }
 641
 642                 dlm_get_next_cookie(dlm->node_num, &tmpcookie);
 643                 lock = dlm_new_lock(mode, dlm->node_num, tmpcookie, lksb);
 644                 if (!lock) {
 645                         dlm_error(status);
 646                         goto error;
 647                 }
 648
 649                 if (!recovery)
 650                         dlm_wait_for_recovery(dlm);
 651
 652                 /* find or create the lock resource */
 653                 res = dlm_get_lock_resource(dlm, name, flags);
 654                 if (!res) {
 655                         status = DLM_IVLOCKID;
 656                         dlm_error(status);
 657                         goto error;
 658                 }
 659
 660                 mlog(0, "type=%d, flags = 0x%x\n", mode, flags);
 661                 mlog(0, "creating lock: lock=%p res=%p\n", lock, res);
 662
 663                 dlm_lock_attach_lockres(lock, res);
 664                 lock->ast = ast;
 665                 lock->bast = bast;
 666                 lock->astdata = data;
 667
 668 retry_lock:
 669                 if (flags & LKM_VALBLK) {
 670                         mlog(0, "LKM_VALBLK passed by caller\n");
 671
 672                         /* LVB requests for non PR, PW or EX locks are
 673                          * ignored. */
 674                         if (mode < LKM_PRMODE)
 675                                 flags &= ~LKM_VALBLK;
 676                         else {
 677                                 flags |= LKM_GET_LVB;
 678                                 lock->lksb->flags |= DLM_LKSB_GET_LVB;
 679                         }
 680                 }
 681
 682                 if (res->owner == dlm->node_num)
 683                         status = dlmlock_master(dlm, res, lock, flags);
 684                 else
 685                         status = dlmlock_remote(dlm, res, lock, flags);
 686
 687                 if (status == DLM_RECOVERING || status == DLM_MIGRATING ||
 688                     status == DLM_FORWARD) {
 689                         mlog(0, "retrying lock with migration/"
 690                              "recovery/in progress\n");
 691                         msleep(100);
 692                         /* no waiting for dlm_reco_thread */
 693                         if (recovery) {
 694                                 if (status == DLM_RECOVERING) {
 695                                         mlog(0, "%s: got RECOVERING "
 696                                              "for $REOCVERY lock, master "
 697                                              "was %u\n", dlm->name,
 698                                              res->owner);
 699                                         dlm_wait_for_node_death(dlm, res->owner,
 700                                                         DLM_NODE_DEATH_WAIT_MAX);
 701                                 }
 702                         } else {
 703                                 dlm_wait_for_recovery(dlm);
 704                         }
 705                         goto retry_lock;
 706                 }
 707
 708                 if (status != DLM_NORMAL) {
 709                         lock->lksb->flags &= ~DLM_LKSB_GET_LVB;
 710                         if (status != DLM_NOTQUEUED)
 711                                 dlm_error(status);
 712                         goto error;
 713                 }
 714         }
 715
 716 error:
 717         if (status != DLM_NORMAL) {
 718                 if (lock && !convert)
 719                         dlm_lock_put(lock);
 720                 // this is kind of unnecessary
 721                 lksb->status = status;
 722         }
 723
 724         /* put lockres ref from the convert path
 725          * or from dlm_get_lock_resource */
 726         if (res)
 727                 dlm_lockres_put(res);
 728
 729         return status;
 730 }
 731 EXPORT_SYMBOL_GPL(dlmlock);