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 DEFINE_SPINLOCK(dlm_cookie_lock);
  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_RECOVERING &&
 231                     dlm_is_recovery_lock(res->lockname.name,
 232                                          res->lockname.len)) {
 233                         /* recovery lock was mastered by dead node.
 234                          * we need to have calc_usage shoot down this
 235                          * lockres and completely remaster it. */
 236                         mlog(0, "%s: recovery lock was owned by "
 237                              "dead node %u, remaster it now.\n",
 238                              dlm->name, res->owner);
 239                 } else if (status != DLM_NOTQUEUED) {
 240                         /*
 241                          * DO NOT call calc_usage, as this would unhash
 242                          * the remote lockres before we ever get to use
 243                          * it.  treat as if we never made any change to
 244                          * the lockres.
 245                          */
 246                         lockres_changed = 0;
 247                         dlm_error(status);
 248                 }
 249                 dlm_revert_pending_lock(res, lock);
 250                 dlm_lock_put(lock);
 251         } else if (dlm_is_recovery_lock(res->lockname.name,
 252                                         res->lockname.len)) {
 253                 /* special case for the $RECOVERY lock.
 254                  * there will never be an AST delivered to put
 255                  * this lock on the proper secondary queue
 256                  * (granted), so do it manually. */
 257                 mlog(0, "%s: $RECOVERY lock for this node (%u) is "
 258                      "mastered by %u; got lock, manually granting (no ast)\n",
 259                      dlm->name, dlm->node_num, res->owner);
 260                 list_move_tail(&lock->list, &res->granted);
 261         }
 262         spin_unlock(&res->spinlock);
 263
 264         if (lockres_changed)
 265                 dlm_lockres_calc_usage(dlm, res);
 266
 267         wake_up(&res->wq);
 268         return status;
 269 }
 270
 271
 272 /* for remote lock creation.
 273  * locking:
 274  *   caller needs:  none, but need res->state & DLM_LOCK_RES_IN_PROGRESS
 275  *   taken:         none
 276  *   held on exit:  none
 277  * returns: DLM_NOLOCKMGR, or net status
 278  */
 279 static enum dlm_status dlm_send_remote_lock_request(struct dlm_ctxt *dlm,
 280                                                struct dlm_lock_resource *res,
 281                                                struct dlm_lock *lock, int flags)
 282 {
 283         struct dlm_create_lock create;
 284         int tmpret, status = 0;
 285         enum dlm_status ret;
 286
 287         mlog_entry_void();
 288
 289         memset(&create, 0, sizeof(create));
 290         create.node_idx = dlm->node_num;
 291         create.requested_type = lock->ml.type;
 292         create.cookie = lock->ml.cookie;
 293         create.namelen = res->lockname.len;
 294         create.flags = cpu_to_be32(flags);
 295         memcpy(create.name, res->lockname.name, create.namelen);
 296
 297         tmpret = o2net_send_message(DLM_CREATE_LOCK_MSG, dlm->key, &create,
 298                                     sizeof(create), res->owner, &status);
 299         if (tmpret >= 0) {
 300                 // successfully sent and received
 301                 ret = status;  // this is already a dlm_status
 302                 if (ret == DLM_REJECTED) {
 303                         mlog(ML_ERROR, "%s:%.*s: BUG.  this is a stale lockres "
 304                              "no longer owned by %u.  that node is coming back "
 305                              "up currently.\n", dlm->name, create.namelen,
 306                              create.name, res->owner);
 307                         dlm_print_one_lock_resource(res);
 308                         BUG();
 309                 }
 310         } else {
 311                 mlog_errno(tmpret);
 312                 if (dlm_is_host_down(tmpret)) {
 313                         ret = DLM_RECOVERING;
 314                         mlog(0, "node %u died so returning DLM_RECOVERING "
 315                              "from lock message!\n", res->owner);
 316                 } else {
 317                         ret = dlm_err_to_dlm_status(tmpret);
 318                 }
 319         }
 320
 321         return ret;
 322 }
 323
 324 void dlm_lock_get(struct dlm_lock *lock)
 325 {
 326         kref_get(&lock->lock_refs);
 327 }
 328
 329 void dlm_lock_put(struct dlm_lock *lock)
 330 {
 331         kref_put(&lock->lock_refs, dlm_lock_release);
 332 }
 333
 334 static void dlm_lock_release(struct kref *kref)
 335 {
 336         struct dlm_lock *lock;
 337
 338         lock = container_of(kref, struct dlm_lock, lock_refs);
 339
 340         BUG_ON(!list_empty(&lock->list));
 341         BUG_ON(!list_empty(&lock->ast_list));
 342         BUG_ON(!list_empty(&lock->bast_list));
 343         BUG_ON(lock->ast_pending);
 344         BUG_ON(lock->bast_pending);
 345
 346         dlm_lock_detach_lockres(lock);
 347
 348         if (lock->lksb_kernel_allocated) {
 349                 mlog(0, "freeing kernel-allocated lksb\n");
 350                 kfree(lock->lksb);
 351         }
 352         kfree(lock);
 353 }
 354
 355 /* associate a lock with it's lockres, getting a ref on the lockres */
 356 void dlm_lock_attach_lockres(struct dlm_lock *lock,
 357                              struct dlm_lock_resource *res)
 358 {
 359         dlm_lockres_get(res);
 360         lock->lockres = res;
 361 }
 362
 363 /* drop ref on lockres, if there is still one associated with lock */
 364 static void dlm_lock_detach_lockres(struct dlm_lock *lock)
 365 {
 366         struct dlm_lock_resource *res;
 367
 368         res = lock->lockres;
 369         if (res) {
 370                 lock->lockres = NULL;
 371                 mlog(0, "removing lock's lockres reference\n");
 372                 dlm_lockres_put(res);
 373         }
 374 }
 375
 376 static void dlm_init_lock(struct dlm_lock *newlock, int type,
 377                           u8 node, u64 cookie)
 378 {
 379         INIT_LIST_HEAD(&newlock->list);
 380         INIT_LIST_HEAD(&newlock->ast_list);
 381         INIT_LIST_HEAD(&newlock->bast_list);
 382         spin_lock_init(&newlock->spinlock);
 383         newlock->ml.type = type;
 384         newlock->ml.convert_type = LKM_IVMODE;
 385         newlock->ml.highest_blocked = LKM_IVMODE;
 386         newlock->ml.node = node;
 387         newlock->ml.pad1 = 0;
 388         newlock->ml.list = 0;
 389         newlock->ml.flags = 0;
 390         newlock->ast = NULL;
 391         newlock->bast = NULL;
 392         newlock->astdata = NULL;
 393         newlock->ml.cookie = cpu_to_be64(cookie);
 394         newlock->ast_pending = 0;
 395         newlock->bast_pending = 0;
 396         newlock->convert_pending = 0;
 397         newlock->lock_pending = 0;
 398         newlock->unlock_pending = 0;
 399         newlock->cancel_pending = 0;
 400         newlock->lksb_kernel_allocated = 0;
 401
 402         kref_init(&newlock->lock_refs);
 403 }
 404
 405 struct dlm_lock * dlm_new_lock(int type, u8 node, u64 cookie,
 406                                struct dlm_lockstatus *lksb)
 407 {
 408         struct dlm_lock *lock;
 409         int kernel_allocated = 0;
 410
 411         lock = kcalloc(1, sizeof(*lock), GFP_NOFS);
 412         if (!lock)
 413                 return NULL;
 414
 415         if (!lksb) {
 416                 /* zero memory only if kernel-allocated */
 417                 lksb = kcalloc(1, sizeof(*lksb), GFP_NOFS);
 418                 if (!lksb) {
 419                         kfree(lock);
 420                         return NULL;
 421                 }
 422                 kernel_allocated = 1;
 423         }
 424
 425         dlm_init_lock(lock, type, node, cookie);
 426         if (kernel_allocated)
 427                 lock->lksb_kernel_allocated = 1;
 428         lock->lksb = lksb;
 429         lksb->lockid = lock;
 430         return lock;
 431 }
 432
 433 /* handler for lock creation net message
 434  * locking:
 435  *   caller needs:  none
 436  *   taken:         takes and drops res->spinlock
 437  *   held on exit:  none
 438  * returns: DLM_NORMAL, DLM_SYSERR, DLM_IVLOCKID, DLM_NOTQUEUED
 439  */
 440 int dlm_create_lock_handler(struct o2net_msg *msg, u32 len, void *data)
 441 {
 442         struct dlm_ctxt *dlm = data;
 443         struct dlm_create_lock *create = (struct dlm_create_lock *)msg->buf;
 444         struct dlm_lock_resource *res = NULL;
 445         struct dlm_lock *newlock = NULL;
 446         struct dlm_lockstatus *lksb = NULL;
 447         enum dlm_status status = DLM_NORMAL;
 448         char *name;
 449         unsigned int namelen;
 450
 451         BUG_ON(!dlm);
 452
 453         mlog_entry_void();
 454
 455         if (!dlm_grab(dlm))
 456                 return DLM_REJECTED;
 457
 458         name = create->name;
 459         namelen = create->namelen;
 460         status = DLM_REJECTED;
 461         if (!dlm_domain_fully_joined(dlm)) {
 462                 mlog(ML_ERROR, "Domain %s not fully joined, but node %u is "
 463                      "sending a create_lock message for lock %.*s!\n",
 464                      dlm->name, create->node_idx, namelen, name);
 465                 dlm_error(status);
 466                 goto leave;
 467         }
 468
 469         status = DLM_IVBUFLEN;
 470         if (namelen > DLM_LOCKID_NAME_MAX) {
 471                 dlm_error(status);
 472                 goto leave;
 473         }
 474
 475         status = DLM_SYSERR;
 476         newlock = dlm_new_lock(create->requested_type,
 477                                create->node_idx,
 478                                be64_to_cpu(create->cookie), NULL);
 479         if (!newlock) {
 480                 dlm_error(status);
 481                 goto leave;
 482         }
 483
 484         lksb = newlock->lksb;
 485
 486         if (be32_to_cpu(create->flags) & LKM_GET_LVB) {
 487                 lksb->flags |= DLM_LKSB_GET_LVB;
 488                 mlog(0, "set DLM_LKSB_GET_LVB flag\n");
 489         }
 490
 491         status = DLM_IVLOCKID;
 492         res = dlm_lookup_lockres(dlm, name, namelen);
 493         if (!res) {
 494                 dlm_error(status);
 495                 goto leave;
 496         }
 497
 498         spin_lock(&res->spinlock);
 499         status = __dlm_lockres_state_to_status(res);
 500         spin_unlock(&res->spinlock);
 501
 502         if (status != DLM_NORMAL) {
 503                 mlog(0, "lockres recovering/migrating/in-progress\n");
 504                 goto leave;
 505         }
 506
 507         dlm_lock_attach_lockres(newlock, res);
 508
 509         status = dlmlock_master(dlm, res, newlock, be32_to_cpu(create->flags));
 510 leave:
 511         if (status != DLM_NORMAL)
 512                 if (newlock)
 513                         dlm_lock_put(newlock);
 514
 515         if (res)
 516                 dlm_lockres_put(res);
 517
 518         dlm_put(dlm);
 519
 520         return status;
 521 }
 522
 523
 524 /* fetch next node-local (u8 nodenum + u56 cookie) into u64 */
 525 static inline void dlm_get_next_cookie(u8 node_num, u64 *cookie)
 526 {
 527         u64 tmpnode = node_num;
 528
 529         /* shift single byte of node num into top 8 bits */
 530         tmpnode <<= 56;
 531
 532         spin_lock(&dlm_cookie_lock);
 533         *cookie = (dlm_next_cookie | tmpnode);
 534         if (++dlm_next_cookie & 0xff00000000000000ull) {
 535                 mlog(0, "This node's cookie will now wrap!\n");
 536                 dlm_next_cookie = 1;
 537         }
 538         spin_unlock(&dlm_cookie_lock);
 539 }
 540
 541 enum dlm_status dlmlock(struct dlm_ctxt *dlm, int mode,
 542                         struct dlm_lockstatus *lksb, int flags,
 543                         const char *name, dlm_astlockfunc_t *ast, void *data,
 544                         dlm_bastlockfunc_t *bast)
 545 {
 546         enum dlm_status status;
 547         struct dlm_lock_resource *res = NULL;
 548         struct dlm_lock *lock = NULL;
 549         int convert = 0, recovery = 0;
 550
 551         /* yes this function is a mess.
 552          * TODO: clean this up.  lots of common code in the
 553          *       lock and convert paths, especially in the retry blocks */
 554         if (!lksb) {
 555                 dlm_error(DLM_BADARGS);
 556                 return DLM_BADARGS;
 557         }
 558
 559         status = DLM_BADPARAM;
 560         if (mode != LKM_EXMODE && mode != LKM_PRMODE && mode != LKM_NLMODE) {
 561                 dlm_error(status);
 562                 goto error;
 563         }
 564
 565         if (flags & ~LKM_VALID_FLAGS) {
 566                 dlm_error(status);
 567                 goto error;
 568         }
 569
 570         convert = (flags & LKM_CONVERT);
 571         recovery = (flags & LKM_RECOVERY);
 572
 573         if (recovery &&
 574             (!dlm_is_recovery_lock(name, strlen(name)) || convert) ) {
 575                 dlm_error(status);
 576                 goto error;
 577         }
 578         if (convert && (flags & LKM_LOCAL)) {
 579                 mlog(ML_ERROR, "strange LOCAL convert request!\n");
 580                 goto error;
 581         }
 582
 583         if (convert) {
 584                 /* CONVERT request */
 585
 586                 /* if converting, must pass in a valid dlm_lock */
 587                 lock = lksb->lockid;
 588                 if (!lock) {
 589                         mlog(ML_ERROR, "NULL lock pointer in convert "
 590                              "request\n");
 591                         goto error;
 592                 }
 593
 594                 res = lock->lockres;
 595                 if (!res) {
 596                         mlog(ML_ERROR, "NULL lockres pointer in convert "
 597                              "request\n");
 598                         goto error;
 599                 }
 600                 dlm_lockres_get(res);
 601
 602                 /* XXX: for ocfs2 purposes, the ast/bast/astdata/lksb are
 603                  * static after the original lock call.  convert requests will
 604                  * ensure that everything is the same, or return DLM_BADARGS.
 605                  * this means that DLM_DENIED_NOASTS will never be returned.
 606                  */
 607                 if (lock->lksb != lksb || lock->ast != ast ||
 608                     lock->bast != bast || lock->astdata != data) {
 609                         status = DLM_BADARGS;
 610                         mlog(ML_ERROR, "new args:  lksb=%p, ast=%p, bast=%p, "
 611                              "astdata=%p\n", lksb, ast, bast, data);
 612                         mlog(ML_ERROR, "orig args: lksb=%p, ast=%p, bast=%p, "
 613                              "astdata=%p\n", lock->lksb, lock->ast,
 614                              lock->bast, lock->astdata);
 615                         goto error;
 616                 }
 617 retry_convert:
 618                 dlm_wait_for_recovery(dlm);
 619
 620                 if (res->owner == dlm->node_num)
 621                         status = dlmconvert_master(dlm, res, lock, flags, mode);
 622                 else
 623                         status = dlmconvert_remote(dlm, res, lock, flags, mode);
 624                 if (status == DLM_RECOVERING || status == DLM_MIGRATING ||
 625                     status == DLM_FORWARD) {
 626                         /* for now, see how this works without sleeping
 627                          * and just retry right away.  I suspect the reco
 628                          * or migration will complete fast enough that
 629                          * no waiting will be necessary */
 630                         mlog(0, "retrying convert with migration/recovery/"
 631                              "in-progress\n");
 632                         msleep(100);
 633                         goto retry_convert;
 634                 }
 635         } else {
 636                 u64 tmpcookie;
 637
 638                 /* LOCK request */
 639                 status = DLM_BADARGS;
 640                 if (!name) {
 641                         dlm_error(status);
 642                         goto error;
 643                 }
 644
 645                 status = DLM_IVBUFLEN;
 646                 if (strlen(name) > DLM_LOCKID_NAME_MAX || strlen(name) < 1) {
 647                         dlm_error(status);
 648                         goto error;
 649                 }
 650
 651                 dlm_get_next_cookie(dlm->node_num, &tmpcookie);
 652                 lock = dlm_new_lock(mode, dlm->node_num, tmpcookie, lksb);
 653                 if (!lock) {
 654                         dlm_error(status);
 655                         goto error;
 656                 }
 657
 658                 if (!recovery)
 659                         dlm_wait_for_recovery(dlm);
 660
 661                 /* find or create the lock resource */
 662                 res = dlm_get_lock_resource(dlm, name, flags);
 663                 if (!res) {
 664                         status = DLM_IVLOCKID;
 665                         dlm_error(status);
 666                         goto error;
 667                 }
 668
 669                 mlog(0, "type=%d, flags = 0x%x\n", mode, flags);
 670                 mlog(0, "creating lock: lock=%p res=%p\n", lock, res);
 671
 672                 dlm_lock_attach_lockres(lock, res);
 673                 lock->ast = ast;
 674                 lock->bast = bast;
 675                 lock->astdata = data;
 676
 677 retry_lock:
 678                 if (flags & LKM_VALBLK) {
 679                         mlog(0, "LKM_VALBLK passed by caller\n");
 680
 681                         /* LVB requests for non PR, PW or EX locks are
 682                          * ignored. */
 683                         if (mode < LKM_PRMODE)
 684                                 flags &= ~LKM_VALBLK;
 685                         else {
 686                                 flags |= LKM_GET_LVB;
 687                                 lock->lksb->flags |= DLM_LKSB_GET_LVB;
 688                         }
 689                 }
 690
 691                 if (res->owner == dlm->node_num)
 692                         status = dlmlock_master(dlm, res, lock, flags);
 693                 else
 694                         status = dlmlock_remote(dlm, res, lock, flags);
 695
 696                 if (status == DLM_RECOVERING || status == DLM_MIGRATING ||
 697                     status == DLM_FORWARD) {
 698                         mlog(0, "retrying lock with migration/"
 699                              "recovery/in progress\n");
 700                         msleep(100);
 701                         /* no waiting for dlm_reco_thread */
 702                         if (recovery) {
 703                                 if (status != DLM_RECOVERING)
 704                                         goto retry_lock;
 705
 706                                 mlog(0, "%s: got RECOVERING "
 707                                      "for $RECOVERY lock, master "
 708                                      "was %u\n", dlm->name,
 709                                      res->owner);
 710                                 /* wait to see the node go down, then
 711                                  * drop down and allow the lockres to
 712                                  * get cleaned up.  need to remaster. */
 713                                 dlm_wait_for_node_death(dlm, res->owner,
 714                                                 DLM_NODE_DEATH_WAIT_MAX);
 715                         } else {
 716                                 dlm_wait_for_recovery(dlm);
 717                                 goto retry_lock;
 718                         }
 719                 }
 720
 721                 if (status != DLM_NORMAL) {
 722                         lock->lksb->flags &= ~DLM_LKSB_GET_LVB;
 723                         if (status != DLM_NOTQUEUED)
 724                                 dlm_error(status);
 725                         goto error;
 726                 }
 727         }
 728
 729 error:
 730         if (status != DLM_NORMAL) {
 731                 if (lock && !convert)
 732                         dlm_lock_put(lock);
 733                 // this is kind of unnecessary
 734                 lksb->status = status;
 735         }
 736
 737         /* put lockres ref from the convert path
 738          * or from dlm_get_lock_resource */
 739         if (res)
 740                 dlm_lockres_put(res);
 741
 742         return status;
 743 }
 744 EXPORT_SYMBOL_GPL(dlmlock);