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/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 #include <linux/delay.h>
  41
  42
  43 #include "cluster/heartbeat.h"
  44 #include "cluster/nodemanager.h"
  45 #include "cluster/tcp.h"
  46
  47 #include "dlmapi.h"
  48 #include "dlmcommon.h"
  49
  50 #include "dlmconvert.h"
  51
  52 #define MLOG_MASK_PREFIX ML_DLM
  53 #include "cluster/masklog.h"
  54
  55 static struct kmem_cache *dlm_lock_cache = NULL;
  56
  57 static DEFINE_SPINLOCK(dlm_cookie_lock);
  58 static u64 dlm_next_cookie = 1;
  59
  60 static enum dlm_status dlm_send_remote_lock_request(struct dlm_ctxt *dlm,
  61                                                struct dlm_lock_resource *res,
  62                                                struct dlm_lock *lock, int flags);
  63 static void dlm_init_lock(struct dlm_lock *newlock, int type,
  64                           u8 node, u64 cookie);
  65 static void dlm_lock_release(struct kref *kref);
  66 static void dlm_lock_detach_lockres(struct dlm_lock *lock);
  67
  68 int dlm_init_lock_cache(void)
  69 {
  70         dlm_lock_cache = kmem_cache_create("o2dlm_lock",
  71                                            sizeof(struct dlm_lock),
  72                                            0, SLAB_HWCACHE_ALIGN, NULL);
  73         if (dlm_lock_cache == NULL)
  74                 return -ENOMEM;
  75         return 0;
  76 }
  77
  78 void dlm_destroy_lock_cache(void)
  79 {
  80         if (dlm_lock_cache)
  81                 kmem_cache_destroy(dlm_lock_cache);
  82 }
  83
  84 /* Tell us whether we can grant a new lock request.
  85  * locking:
  86  *   caller needs:  res->spinlock
  87  *   taken:         none
  88  *   held on exit:  none
  89  * returns: 1 if the lock can be granted, 0 otherwise.
  90  */
  91 static int dlm_can_grant_new_lock(struct dlm_lock_resource *res,
  92                                   struct dlm_lock *lock)
  93 {
  94         struct list_head *iter;
  95         struct dlm_lock *tmplock;
  96
  97         list_for_each(iter, &res->granted) {
  98                 tmplock = list_entry(iter, struct dlm_lock, list);
  99
 100                 if (!dlm_lock_compatible(tmplock->ml.type, lock->ml.type))
 101                         return 0;
 102         }
 103
 104         list_for_each(iter, &res->converting) {
 105                 tmplock = list_entry(iter, struct dlm_lock, list);
 106
 107                 if (!dlm_lock_compatible(tmplock->ml.type, lock->ml.type))
 108                         return 0;
 109                 if (!dlm_lock_compatible(tmplock->ml.convert_type,
 110                                          lock->ml.type))
 111                         return 0;
 112         }
 113
 114         return 1;
 115 }
 116
 117 /* performs lock creation at the lockres master site
 118  * locking:
 119  *   caller needs:  none
 120  *   taken:         takes and drops res->spinlock
 121  *   held on exit:  none
 122  * returns: DLM_NORMAL, DLM_NOTQUEUED
 123  */
 124 static enum dlm_status dlmlock_master(struct dlm_ctxt *dlm,
 125                                       struct dlm_lock_resource *res,
 126                                       struct dlm_lock *lock, int flags)
 127 {
 128         int call_ast = 0, kick_thread = 0;
 129         enum dlm_status status = DLM_NORMAL;
 130
 131         mlog(0, "type=%d\n", lock->ml.type);
 132
 133         spin_lock(&res->spinlock);
 134         /* if called from dlm_create_lock_handler, need to
 135          * ensure it will not sleep in dlm_wait_on_lockres */
 136         status = __dlm_lockres_state_to_status(res);
 137         if (status != DLM_NORMAL &&
 138             lock->ml.node != dlm->node_num) {
 139                 /* erf.  state changed after lock was dropped. */
 140                 spin_unlock(&res->spinlock);
 141                 dlm_error(status);
 142                 return status;
 143         }
 144         __dlm_wait_on_lockres(res);
 145         __dlm_lockres_reserve_ast(res);
 146
 147         if (dlm_can_grant_new_lock(res, lock)) {
 148                 mlog(0, "I can grant this lock right away\n");
 149                 /* got it right away */
 150                 lock->lksb->status = DLM_NORMAL;
 151                 status = DLM_NORMAL;
 152                 dlm_lock_get(lock);
 153                 list_add_tail(&lock->list, &res->granted);
 154
 155                 /* for the recovery lock, we can't allow the ast
 156                  * to be queued since the dlmthread is already
 157                  * frozen.  but the recovery lock is always locked
 158                  * with LKM_NOQUEUE so we do not need the ast in
 159                  * this special case */
 160                 if (!dlm_is_recovery_lock(res->lockname.name,
 161                                           res->lockname.len)) {
 162                         kick_thread = 1;
 163                         call_ast = 1;
 164                 } else {
 165                         mlog(0, "%s: returning DLM_NORMAL to "
 166                              "node %u for reco lock\n", dlm->name,
 167                              lock->ml.node);
 168                 }
 169         } else {
 170                 /* for NOQUEUE request, unless we get the
 171                  * lock right away, return DLM_NOTQUEUED */
 172                 if (flags & LKM_NOQUEUE) {
 173                         status = DLM_NOTQUEUED;
 174                         if (dlm_is_recovery_lock(res->lockname.name,
 175                                                  res->lockname.len)) {
 176                                 mlog(0, "%s: returning NOTQUEUED to "
 177                                      "node %u for reco lock\n", dlm->name,
 178                                      lock->ml.node);
 179                         }
 180                 } else {
 181                         dlm_lock_get(lock);
 182                         list_add_tail(&lock->list, &res->blocked);
 183                         kick_thread = 1;
 184                 }
 185         }
 186
 187         spin_unlock(&res->spinlock);
 188         wake_up(&res->wq);
 189
 190         /* either queue the ast or release it */
 191         if (call_ast)
 192                 dlm_queue_ast(dlm, lock);
 193         else
 194                 dlm_lockres_release_ast(dlm, res);
 195
 196         dlm_lockres_calc_usage(dlm, res);
 197         if (kick_thread)
 198                 dlm_kick_thread(dlm, res);
 199
 200         return status;
 201 }
 202
 203 void dlm_revert_pending_lock(struct dlm_lock_resource *res,
 204                              struct dlm_lock *lock)
 205 {
 206         /* remove from local queue if it failed */
 207         list_del_init(&lock->list);
 208         lock->lksb->flags &= ~DLM_LKSB_GET_LVB;
 209 }
 210
 211
 212 /*
 213  * locking:
 214  *   caller needs:  none
 215  *   taken:         takes and drops res->spinlock
 216  *   held on exit:  none
 217  * returns: DLM_DENIED, DLM_RECOVERING, or net status
 218  */
 219 static enum dlm_status dlmlock_remote(struct dlm_ctxt *dlm,
 220                                       struct dlm_lock_resource *res,
 221                                       struct dlm_lock *lock, int flags)
 222 {
 223         enum dlm_status status = DLM_DENIED;
 224         int lockres_changed = 1;
 225
 226         mlog(0, "type=%d, lockres %.*s, flags = 0x%x\n",
 227              lock->ml.type, res->lockname.len,
 228              res->lockname.name, flags);
 229
 230         /*
 231          * Wait if resource is getting recovered, remastered, etc.
 232          * If the resource was remastered and new owner is self, then exit.
 233          */
 234         spin_lock(&res->spinlock);
 235         __dlm_wait_on_lockres(res);
 236         if (res->owner == dlm->node_num) {
 237                 spin_unlock(&res->spinlock);
 238                 return DLM_RECOVERING;
 239         }
 240         res->state |= DLM_LOCK_RES_IN_PROGRESS;
 241
 242         /* add lock to local (secondary) queue */
 243         dlm_lock_get(lock);
 244         list_add_tail(&lock->list, &res->blocked);
 245         lock->lock_pending = 1;
 246         spin_unlock(&res->spinlock);
 247
 248         /* spec seems to say that you will get DLM_NORMAL when the lock
 249          * has been queued, meaning we need to wait for a reply here. */
 250         status = dlm_send_remote_lock_request(dlm, res, lock, flags);
 251
 252         spin_lock(&res->spinlock);
 253         res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
 254         lock->lock_pending = 0;
 255         if (status != DLM_NORMAL) {
 256                 if (status == DLM_RECOVERING &&
 257                     dlm_is_recovery_lock(res->lockname.name,
 258                                          res->lockname.len)) {
 259                         /* recovery lock was mastered by dead node.
 260                          * we need to have calc_usage shoot down this
 261                          * lockres and completely remaster it. */
 262                         mlog(0, "%s: recovery lock was owned by "
 263                              "dead node %u, remaster it now.\n",
 264                              dlm->name, res->owner);
 265                 } else if (status != DLM_NOTQUEUED) {
 266                         /*
 267                          * DO NOT call calc_usage, as this would unhash
 268                          * the remote lockres before we ever get to use
 269                          * it.  treat as if we never made any change to
 270                          * the lockres.
 271                          */
 272                         lockres_changed = 0;
 273                         dlm_error(status);
 274                 }
 275                 dlm_revert_pending_lock(res, lock);
 276                 dlm_lock_put(lock);
 277         } else if (dlm_is_recovery_lock(res->lockname.name,
 278                                         res->lockname.len)) {
 279                 /* special case for the $RECOVERY lock.
 280                  * there will never be an AST delivered to put
 281                  * this lock on the proper secondary queue
 282                  * (granted), so do it manually. */
 283                 mlog(0, "%s: $RECOVERY lock for this node (%u) is "
 284                      "mastered by %u; got lock, manually granting (no ast)\n",
 285                      dlm->name, dlm->node_num, res->owner);
 286                 list_move_tail(&lock->list, &res->granted);
 287         }
 288         spin_unlock(&res->spinlock);
 289
 290         if (lockres_changed)
 291                 dlm_lockres_calc_usage(dlm, res);
 292
 293         wake_up(&res->wq);
 294         return status;
 295 }
 296
 297
 298 /* for remote lock creation.
 299  * locking:
 300  *   caller needs:  none, but need res->state & DLM_LOCK_RES_IN_PROGRESS
 301  *   taken:         none
 302  *   held on exit:  none
 303  * returns: DLM_NOLOCKMGR, or net status
 304  */
 305 static enum dlm_status dlm_send_remote_lock_request(struct dlm_ctxt *dlm,
 306                                                struct dlm_lock_resource *res,
 307                                                struct dlm_lock *lock, int flags)
 308 {
 309         struct dlm_create_lock create;
 310         int tmpret, status = 0;
 311         enum dlm_status ret;
 312
 313         memset(&create, 0, sizeof(create));
 314         create.node_idx = dlm->node_num;
 315         create.requested_type = lock->ml.type;
 316         create.cookie = lock->ml.cookie;
 317         create.namelen = res->lockname.len;
 318         create.flags = cpu_to_be32(flags);
 319         memcpy(create.name, res->lockname.name, create.namelen);
 320
 321         tmpret = o2net_send_message(DLM_CREATE_LOCK_MSG, dlm->key, &create,
 322                                     sizeof(create), res->owner, &status);
 323         if (tmpret >= 0) {
 324                 ret = status;
 325                 if (ret == DLM_REJECTED) {
 326                         mlog(ML_ERROR, "%s: res %.*s, Stale lockres no longer "
 327                              "owned by node %u. That node is coming back up "
 328                              "currently.\n", dlm->name, create.namelen,
 329                              create.name, res->owner);
 330                         dlm_print_one_lock_resource(res);
 331                         BUG();
 332                 }
 333         } else {
 334                 mlog(ML_ERROR, "%s: res %.*s, Error %d send CREATE LOCK to "
 335                      "node %u\n", dlm->name, create.namelen, create.name,
 336                      tmpret, res->owner);
 337                 if (dlm_is_host_down(tmpret))
 338                         ret = DLM_RECOVERING;
 339                 else
 340                         ret = dlm_err_to_dlm_status(tmpret);
 341         }
 342
 343         return ret;
 344 }
 345
 346 void dlm_lock_get(struct dlm_lock *lock)
 347 {
 348         kref_get(&lock->lock_refs);
 349 }
 350
 351 void dlm_lock_put(struct dlm_lock *lock)
 352 {
 353         kref_put(&lock->lock_refs, dlm_lock_release);
 354 }
 355
 356 static void dlm_lock_release(struct kref *kref)
 357 {
 358         struct dlm_lock *lock;
 359
 360         lock = container_of(kref, struct dlm_lock, lock_refs);
 361
 362         BUG_ON(!list_empty(&lock->list));
 363         BUG_ON(!list_empty(&lock->ast_list));
 364         BUG_ON(!list_empty(&lock->bast_list));
 365         BUG_ON(lock->ast_pending);
 366         BUG_ON(lock->bast_pending);
 367
 368         dlm_lock_detach_lockres(lock);
 369
 370         if (lock->lksb_kernel_allocated) {
 371                 mlog(0, "freeing kernel-allocated lksb\n");
 372                 kfree(lock->lksb);
 373         }
 374         kmem_cache_free(dlm_lock_cache, lock);
 375 }
 376
 377 /* associate a lock with it's lockres, getting a ref on the lockres */
 378 void dlm_lock_attach_lockres(struct dlm_lock *lock,
 379                              struct dlm_lock_resource *res)
 380 {
 381         dlm_lockres_get(res);
 382         lock->lockres = res;
 383 }
 384
 385 /* drop ref on lockres, if there is still one associated with lock */
 386 static void dlm_lock_detach_lockres(struct dlm_lock *lock)
 387 {
 388         struct dlm_lock_resource *res;
 389
 390         res = lock->lockres;
 391         if (res) {
 392                 lock->lockres = NULL;
 393                 mlog(0, "removing lock's lockres reference\n");
 394                 dlm_lockres_put(res);
 395         }
 396 }
 397
 398 static void dlm_init_lock(struct dlm_lock *newlock, int type,
 399                           u8 node, u64 cookie)
 400 {
 401         INIT_LIST_HEAD(&newlock->list);
 402         INIT_LIST_HEAD(&newlock->ast_list);
 403         INIT_LIST_HEAD(&newlock->bast_list);
 404         spin_lock_init(&newlock->spinlock);
 405         newlock->ml.type = type;
 406         newlock->ml.convert_type = LKM_IVMODE;
 407         newlock->ml.highest_blocked = LKM_IVMODE;
 408         newlock->ml.node = node;
 409         newlock->ml.pad1 = 0;
 410         newlock->ml.list = 0;
 411         newlock->ml.flags = 0;
 412         newlock->ast = NULL;
 413         newlock->bast = NULL;
 414         newlock->astdata = NULL;
 415         newlock->ml.cookie = cpu_to_be64(cookie);
 416         newlock->ast_pending = 0;
 417         newlock->bast_pending = 0;
 418         newlock->convert_pending = 0;
 419         newlock->lock_pending = 0;
 420         newlock->unlock_pending = 0;
 421         newlock->cancel_pending = 0;
 422         newlock->lksb_kernel_allocated = 0;
 423
 424         kref_init(&newlock->lock_refs);
 425 }
 426
 427 struct dlm_lock * dlm_new_lock(int type, u8 node, u64 cookie,
 428                                struct dlm_lockstatus *lksb)
 429 {
 430         struct dlm_lock *lock;
 431         int kernel_allocated = 0;
 432
 433         lock = kmem_cache_zalloc(dlm_lock_cache, GFP_NOFS);
 434         if (!lock)
 435                 return NULL;
 436
 437         if (!lksb) {
 438                 /* zero memory only if kernel-allocated */
 439                 lksb = kzalloc(sizeof(*lksb), GFP_NOFS);
 440                 if (!lksb) {
 441                         kmem_cache_free(dlm_lock_cache, lock);
 442                         return NULL;
 443                 }
 444                 kernel_allocated = 1;
 445         }
 446
 447         dlm_init_lock(lock, type, node, cookie);
 448         if (kernel_allocated)
 449                 lock->lksb_kernel_allocated = 1;
 450         lock->lksb = lksb;
 451         lksb->lockid = lock;
 452         return lock;
 453 }
 454
 455 /* handler for lock creation net message
 456  * locking:
 457  *   caller needs:  none
 458  *   taken:         takes and drops res->spinlock
 459  *   held on exit:  none
 460  * returns: DLM_NORMAL, DLM_SYSERR, DLM_IVLOCKID, DLM_NOTQUEUED
 461  */
 462 int dlm_create_lock_handler(struct o2net_msg *msg, u32 len, void *data,
 463                             void **ret_data)
 464 {
 465         struct dlm_ctxt *dlm = data;
 466         struct dlm_create_lock *create = (struct dlm_create_lock *)msg->buf;
 467         struct dlm_lock_resource *res = NULL;
 468         struct dlm_lock *newlock = NULL;
 469         struct dlm_lockstatus *lksb = NULL;
 470         enum dlm_status status = DLM_NORMAL;
 471         char *name;
 472         unsigned int namelen;
 473
 474         BUG_ON(!dlm);
 475
 476         if (!dlm_grab(dlm))
 477                 return DLM_REJECTED;
 478
 479         name = create->name;
 480         namelen = create->namelen;
 481         status = DLM_REJECTED;
 482         if (!dlm_domain_fully_joined(dlm)) {
 483                 mlog(ML_ERROR, "Domain %s not fully joined, but node %u is "
 484                      "sending a create_lock message for lock %.*s!\n",
 485                      dlm->name, create->node_idx, namelen, name);
 486                 dlm_error(status);
 487                 goto leave;
 488         }
 489
 490         status = DLM_IVBUFLEN;
 491         if (namelen > DLM_LOCKID_NAME_MAX) {
 492                 dlm_error(status);
 493                 goto leave;
 494         }
 495
 496         status = DLM_SYSERR;
 497         newlock = dlm_new_lock(create->requested_type,
 498                                create->node_idx,
 499                                be64_to_cpu(create->cookie), NULL);
 500         if (!newlock) {
 501                 dlm_error(status);
 502                 goto leave;
 503         }
 504
 505         lksb = newlock->lksb;
 506
 507         if (be32_to_cpu(create->flags) & LKM_GET_LVB) {
 508                 lksb->flags |= DLM_LKSB_GET_LVB;
 509                 mlog(0, "set DLM_LKSB_GET_LVB flag\n");
 510         }
 511
 512         status = DLM_IVLOCKID;
 513         res = dlm_lookup_lockres(dlm, name, namelen);
 514         if (!res) {
 515                 dlm_error(status);
 516                 goto leave;
 517         }
 518
 519         spin_lock(&res->spinlock);
 520         status = __dlm_lockres_state_to_status(res);
 521         spin_unlock(&res->spinlock);
 522
 523         if (status != DLM_NORMAL) {
 524                 mlog(0, "lockres recovering/migrating/in-progress\n");
 525                 goto leave;
 526         }
 527
 528         dlm_lock_attach_lockres(newlock, res);
 529
 530         status = dlmlock_master(dlm, res, newlock, be32_to_cpu(create->flags));
 531 leave:
 532         if (status != DLM_NORMAL)
 533                 if (newlock)
 534                         dlm_lock_put(newlock);
 535
 536         if (res)
 537                 dlm_lockres_put(res);
 538
 539         dlm_put(dlm);
 540
 541         return status;
 542 }
 543
 544
 545 /* fetch next node-local (u8 nodenum + u56 cookie) into u64 */
 546 static inline void dlm_get_next_cookie(u8 node_num, u64 *cookie)
 547 {
 548         u64 tmpnode = node_num;
 549
 550         /* shift single byte of node num into top 8 bits */
 551         tmpnode <<= 56;
 552
 553         spin_lock(&dlm_cookie_lock);
 554         *cookie = (dlm_next_cookie | tmpnode);
 555         if (++dlm_next_cookie & 0xff00000000000000ull) {
 556                 mlog(0, "This node's cookie will now wrap!\n");
 557                 dlm_next_cookie = 1;
 558         }
 559         spin_unlock(&dlm_cookie_lock);
 560 }
 561
 562 enum dlm_status dlmlock(struct dlm_ctxt *dlm, int mode,
 563                         struct dlm_lockstatus *lksb, int flags,
 564                         const char *name, int namelen, dlm_astlockfunc_t *ast,
 565                         void *data, dlm_bastlockfunc_t *bast)
 566 {
 567         enum dlm_status status;
 568         struct dlm_lock_resource *res = NULL;
 569         struct dlm_lock *lock = NULL;
 570         int convert = 0, recovery = 0;
 571
 572         /* yes this function is a mess.
 573          * TODO: clean this up.  lots of common code in the
 574          *       lock and convert paths, especially in the retry blocks */
 575         if (!lksb) {
 576                 dlm_error(DLM_BADARGS);
 577                 return DLM_BADARGS;
 578         }
 579
 580         status = DLM_BADPARAM;
 581         if (mode != LKM_EXMODE && mode != LKM_PRMODE && mode != LKM_NLMODE) {
 582                 dlm_error(status);
 583                 goto error;
 584         }
 585
 586         if (flags & ~LKM_VALID_FLAGS) {
 587                 dlm_error(status);
 588                 goto error;
 589         }
 590
 591         convert = (flags & LKM_CONVERT);
 592         recovery = (flags & LKM_RECOVERY);
 593
 594         if (recovery &&
 595             (!dlm_is_recovery_lock(name, namelen) || convert) ) {
 596                 dlm_error(status);
 597                 goto error;
 598         }
 599         if (convert && (flags & LKM_LOCAL)) {
 600                 mlog(ML_ERROR, "strange LOCAL convert request!\n");
 601                 goto error;
 602         }
 603
 604         if (convert) {
 605                 /* CONVERT request */
 606
 607                 /* if converting, must pass in a valid dlm_lock */
 608                 lock = lksb->lockid;
 609                 if (!lock) {
 610                         mlog(ML_ERROR, "NULL lock pointer in convert "
 611                              "request\n");
 612                         goto error;
 613                 }
 614
 615                 res = lock->lockres;
 616                 if (!res) {
 617                         mlog(ML_ERROR, "NULL lockres pointer in convert "
 618                              "request\n");
 619                         goto error;
 620                 }
 621                 dlm_lockres_get(res);
 622
 623                 /* XXX: for ocfs2 purposes, the ast/bast/astdata/lksb are
 624                  * static after the original lock call.  convert requests will
 625                  * ensure that everything is the same, or return DLM_BADARGS.
 626                  * this means that DLM_DENIED_NOASTS will never be returned.
 627                  */
 628                 if (lock->lksb != lksb || lock->ast != ast ||
 629                     lock->bast != bast || lock->astdata != data) {
 630                         status = DLM_BADARGS;
 631                         mlog(ML_ERROR, "new args:  lksb=%p, ast=%p, bast=%p, "
 632                              "astdata=%p\n", lksb, ast, bast, data);
 633                         mlog(ML_ERROR, "orig args: lksb=%p, ast=%p, bast=%p, "
 634                              "astdata=%p\n", lock->lksb, lock->ast,
 635                              lock->bast, lock->astdata);
 636                         goto error;
 637                 }
 638 retry_convert:
 639                 dlm_wait_for_recovery(dlm);
 640
 641                 if (res->owner == dlm->node_num)
 642                         status = dlmconvert_master(dlm, res, lock, flags, mode);
 643                 else
 644                         status = dlmconvert_remote(dlm, res, lock, flags, mode);
 645                 if (status == DLM_RECOVERING || status == DLM_MIGRATING ||
 646                     status == DLM_FORWARD) {
 647                         /* for now, see how this works without sleeping
 648                          * and just retry right away.  I suspect the reco
 649                          * or migration will complete fast enough that
 650                          * no waiting will be necessary */
 651                         mlog(0, "retrying convert with migration/recovery/"
 652                              "in-progress\n");
 653                         msleep(100);
 654                         goto retry_convert;
 655                 }
 656         } else {
 657                 u64 tmpcookie;
 658
 659                 /* LOCK request */
 660                 status = DLM_BADARGS;
 661                 if (!name) {
 662                         dlm_error(status);
 663                         goto error;
 664                 }
 665
 666                 status = DLM_IVBUFLEN;
 667                 if (namelen > DLM_LOCKID_NAME_MAX || namelen < 1) {
 668                         dlm_error(status);
 669                         goto error;
 670                 }
 671
 672                 dlm_get_next_cookie(dlm->node_num, &tmpcookie);
 673                 lock = dlm_new_lock(mode, dlm->node_num, tmpcookie, lksb);
 674                 if (!lock) {
 675                         dlm_error(status);
 676                         goto error;
 677                 }
 678
 679                 if (!recovery)
 680                         dlm_wait_for_recovery(dlm);
 681
 682                 /* find or create the lock resource */
 683                 res = dlm_get_lock_resource(dlm, name, namelen, flags);
 684                 if (!res) {
 685                         status = DLM_IVLOCKID;
 686                         dlm_error(status);
 687                         goto error;
 688                 }
 689
 690                 mlog(0, "type=%d, flags = 0x%x\n", mode, flags);
 691                 mlog(0, "creating lock: lock=%p res=%p\n", lock, res);
 692
 693                 dlm_lock_attach_lockres(lock, res);
 694                 lock->ast = ast;
 695                 lock->bast = bast;
 696                 lock->astdata = data;
 697
 698 retry_lock:
 699                 if (flags & LKM_VALBLK) {
 700                         mlog(0, "LKM_VALBLK passed by caller\n");
 701
 702                         /* LVB requests for non PR, PW or EX locks are
 703                          * ignored. */
 704                         if (mode < LKM_PRMODE)
 705                                 flags &= ~LKM_VALBLK;
 706                         else {
 707                                 flags |= LKM_GET_LVB;
 708                                 lock->lksb->flags |= DLM_LKSB_GET_LVB;
 709                         }
 710                 }
 711
 712                 if (res->owner == dlm->node_num)
 713                         status = dlmlock_master(dlm, res, lock, flags);
 714                 else
 715                         status = dlmlock_remote(dlm, res, lock, flags);
 716
 717                 if (status == DLM_RECOVERING || status == DLM_MIGRATING ||
 718                     status == DLM_FORWARD) {
 719                         msleep(100);
 720                         if (recovery) {
 721                                 if (status != DLM_RECOVERING)
 722                                         goto retry_lock;
 723                                 /* wait to see the node go down, then
 724                                  * drop down and allow the lockres to
 725                                  * get cleaned up.  need to remaster. */
 726                                 dlm_wait_for_node_death(dlm, res->owner,
 727                                                 DLM_NODE_DEATH_WAIT_MAX);
 728                         } else {
 729                                 dlm_wait_for_recovery(dlm);
 730                                 goto retry_lock;
 731                         }
 732                 }
 733
 734                 /* Inflight taken in dlm_get_lock_resource() is dropped here */
 735                 spin_lock(&res->spinlock);
 736                 dlm_lockres_drop_inflight_ref(dlm, res);
 737                 spin_unlock(&res->spinlock);
 738
 739                 dlm_lockres_calc_usage(dlm, res);
 740                 dlm_kick_thread(dlm, res);
 741
 742                 if (status != DLM_NORMAL) {
 743                         lock->lksb->flags &= ~DLM_LKSB_GET_LVB;
 744                         if (status != DLM_NOTQUEUED)
 745                                 dlm_error(status);
 746                         goto error;
 747                 }
 748         }
 749
 750 error:
 751         if (status != DLM_NORMAL) {
 752                 if (lock && !convert)
 753                         dlm_lock_put(lock);
 754                 // this is kind of unnecessary
 755                 lksb->status = status;
 756         }
 757
 758         /* put lockres ref from the convert path
 759          * or from dlm_get_lock_resource */
 760         if (res)
 761                 dlm_lockres_put(res);
 762
 763         return status;
 764 }
 765 EXPORT_SYMBOL_GPL(dlmlock);