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