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