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         }
 110
 111         return 1;
 112 }
 113
 114 /* performs lock creation at the lockres master site
 115  * locking:
 116  *   caller needs:  none
 117  *   taken:         takes and drops res->spinlock
 118  *   held on exit:  none
 119  * returns: DLM_NORMAL, DLM_NOTQUEUED
 120  */
 121 static enum dlm_status dlmlock_master(struct dlm_ctxt *dlm,
 122                                       struct dlm_lock_resource *res,
 123                                       struct dlm_lock *lock, int flags)
 124 {
 125         int call_ast = 0, kick_thread = 0;
 126         enum dlm_status status = DLM_NORMAL;
 127
 128         mlog_entry("type=%d\n", lock->ml.type);
 129
 130         spin_lock(&res->spinlock);
 131         /* if called from dlm_create_lock_handler, need to
 132          * ensure it will not sleep in dlm_wait_on_lockres */
 133         status = __dlm_lockres_state_to_status(res);
 134         if (status != DLM_NORMAL &&
 135             lock->ml.node != dlm->node_num) {
 136                 /* erf.  state changed after lock was dropped. */
 137                 spin_unlock(&res->spinlock);
 138                 dlm_error(status);
 139                 return status;
 140         }
 141         __dlm_wait_on_lockres(res);
 142         __dlm_lockres_reserve_ast(res);
 143
 144         if (dlm_can_grant_new_lock(res, lock)) {
 145                 mlog(0, "I can grant this lock right away\n");
 146                 /* got it right away */
 147                 lock->lksb->status = DLM_NORMAL;
 148                 status = DLM_NORMAL;
 149                 dlm_lock_get(lock);
 150                 list_add_tail(&lock->list, &res->granted);
 151
 152                 /* for the recovery lock, we can't allow the ast
 153                  * to be queued since the dlmthread is already
 154                  * frozen.  but the recovery lock is always locked
 155                  * with LKM_NOQUEUE so we do not need the ast in
 156                  * this special case */
 157                 if (!dlm_is_recovery_lock(res->lockname.name,
 158                                           res->lockname.len)) {
 159                         kick_thread = 1;
 160                         call_ast = 1;
 161                 } else {
 162                         mlog(0, "%s: returning DLM_NORMAL to "
 163                              "node %u for reco lock\n", dlm->name,
 164                              lock->ml.node);
 165                 }
 166         } else {
 167                 /* for NOQUEUE request, unless we get the
 168                  * lock right away, return DLM_NOTQUEUED */
 169                 if (flags & LKM_NOQUEUE) {
 170                         status = DLM_NOTQUEUED;
 171                         if (dlm_is_recovery_lock(res->lockname.name,
 172                                                  res->lockname.len)) {
 173                                 mlog(0, "%s: returning NOTQUEUED to "
 174                                      "node %u for reco lock\n", dlm->name,
 175                                      lock->ml.node);
 176                         }
 177                 } else {
 178                         dlm_lock_get(lock);
 179                         list_add_tail(&lock->list, &res->blocked);
 180                         kick_thread = 1;
 181                 }
 182         }
 183         /* reduce the inflight count, this may result in the lockres
 184          * being purged below during calc_usage */
 185         if (lock->ml.node == dlm->node_num)
 186                 dlm_lockres_drop_inflight_ref(dlm, res);
 187
 188         spin_unlock(&res->spinlock);
 189         wake_up(&res->wq);
 190
 191         /* either queue the ast or release it */
 192         if (call_ast)
 193                 dlm_queue_ast(dlm, lock);
 194         else
 195                 dlm_lockres_release_ast(dlm, res);
 196
 197         dlm_lockres_calc_usage(dlm, res);
 198         if (kick_thread)
 199                 dlm_kick_thread(dlm, res);
 200
 201         return status;
 202 }
 203
 204 void dlm_revert_pending_lock(struct dlm_lock_resource *res,
 205                              struct dlm_lock *lock)
 206 {
 207         /* remove from local queue if it failed */
 208         list_del_init(&lock->list);
 209         lock->lksb->flags &= ~DLM_LKSB_GET_LVB;
 210 }
 211
 212
 213 /*
 214  * locking:
 215  *   caller needs:  none
 216  *   taken:         takes and drops res->spinlock
 217  *   held on exit:  none
 218  * returns: DLM_DENIED, DLM_RECOVERING, or net status
 219  */
 220 static enum dlm_status dlmlock_remote(struct dlm_ctxt *dlm,
 221                                       struct dlm_lock_resource *res,
 222                                       struct dlm_lock *lock, int flags)
 223 {
 224         enum dlm_status status = DLM_DENIED;
 225         int lockres_changed = 1;
 226
 227         mlog_entry("type=%d\n", lock->ml.type);
 228         mlog(0, "lockres %.*s, flags = 0x%x\n", res->lockname.len,
 229              res->lockname.name, flags);
 230
 231         spin_lock(&res->spinlock);
 232
 233         /* will exit this call with spinlock held */
 234         __dlm_wait_on_lockres(res);
 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         mlog_entry_void();
 309
 310         memset(&create, 0, sizeof(create));
 311         create.node_idx = dlm->node_num;
 312         create.requested_type = lock->ml.type;
 313         create.cookie = lock->ml.cookie;
 314         create.namelen = res->lockname.len;
 315         create.flags = cpu_to_be32(flags);
 316         memcpy(create.name, res->lockname.name, create.namelen);
 317
 318         tmpret = o2net_send_message(DLM_CREATE_LOCK_MSG, dlm->key, &create,
 319                                     sizeof(create), res->owner, &status);
 320         if (tmpret >= 0) {
 321                 // successfully sent and received
 322                 ret = status;  // this is already a dlm_status
 323                 if (ret == DLM_REJECTED) {
 324                         mlog(ML_ERROR, "%s:%.*s: BUG.  this is a stale lockres "
 325                              "no longer owned by %u.  that node is coming back "
 326                              "up currently.\n", dlm->name, create.namelen,
 327                              create.name, res->owner);
 328                         dlm_print_one_lock_resource(res);
 329                         BUG();
 330                 }
 331         } else {
 332                 mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
 333                      "node %u\n", tmpret, DLM_CREATE_LOCK_MSG, dlm->key,
 334                      res->owner);
 335                 if (dlm_is_host_down(tmpret)) {
 336                         ret = DLM_RECOVERING;
 337                         mlog(0, "node %u died so returning DLM_RECOVERING "
 338                              "from lock message!\n", res->owner);
 339                 } else {
 340                         ret = dlm_err_to_dlm_status(tmpret);
 341                 }
 342         }
 343
 344         return ret;
 345 }
 346
 347 void dlm_lock_get(struct dlm_lock *lock)
 348 {
 349         kref_get(&lock->lock_refs);
 350 }
 351
 352 void dlm_lock_put(struct dlm_lock *lock)
 353 {
 354         kref_put(&lock->lock_refs, dlm_lock_release);
 355 }
 356
 357 static void dlm_lock_release(struct kref *kref)
 358 {
 359         struct dlm_lock *lock;
 360
 361         lock = container_of(kref, struct dlm_lock, lock_refs);
 362
 363         BUG_ON(!list_empty(&lock->list));
 364         BUG_ON(!list_empty(&lock->ast_list));
 365         BUG_ON(!list_empty(&lock->bast_list));
 366         BUG_ON(lock->ast_pending);
 367         BUG_ON(lock->bast_pending);
 368
 369         dlm_lock_detach_lockres(lock);
 370
 371         if (lock->lksb_kernel_allocated) {
 372                 mlog(0, "freeing kernel-allocated lksb\n");
 373                 kfree(lock->lksb);
 374         }
 375         kmem_cache_free(dlm_lock_cache, lock);
 376 }
 377
 378 /* associate a lock with it's lockres, getting a ref on the lockres */
 379 void dlm_lock_attach_lockres(struct dlm_lock *lock,
 380                              struct dlm_lock_resource *res)
 381 {
 382         dlm_lockres_get(res);
 383         lock->lockres = res;
 384 }
 385
 386 /* drop ref on lockres, if there is still one associated with lock */
 387 static void dlm_lock_detach_lockres(struct dlm_lock *lock)
 388 {
 389         struct dlm_lock_resource *res;
 390
 391         res = lock->lockres;
 392         if (res) {
 393                 lock->lockres = NULL;
 394                 mlog(0, "removing lock's lockres reference\n");
 395                 dlm_lockres_put(res);
 396         }
 397 }
 398
 399 static void dlm_init_lock(struct dlm_lock *newlock, int type,
 400                           u8 node, u64 cookie)
 401 {
 402         INIT_LIST_HEAD(&newlock->list);
 403         INIT_LIST_HEAD(&newlock->ast_list);
 404         INIT_LIST_HEAD(&newlock->bast_list);
 405         spin_lock_init(&newlock->spinlock);
 406         newlock->ml.type = type;
 407         newlock->ml.convert_type = LKM_IVMODE;
 408         newlock->ml.highest_blocked = LKM_IVMODE;
 409         newlock->ml.node = node;
 410         newlock->ml.pad1 = 0;
 411         newlock->ml.list = 0;
 412         newlock->ml.flags = 0;
 413         newlock->ast = NULL;
 414         newlock->bast = NULL;
 415         newlock->astdata = NULL;
 416         newlock->ml.cookie = cpu_to_be64(cookie);
 417         newlock->ast_pending = 0;
 418         newlock->bast_pending = 0;
 419         newlock->convert_pending = 0;
 420         newlock->lock_pending = 0;
 421         newlock->unlock_pending = 0;
 422         newlock->cancel_pending = 0;
 423         newlock->lksb_kernel_allocated = 0;
 424
 425         kref_init(&newlock->lock_refs);
 426 }
 427
 428 struct dlm_lock * dlm_new_lock(int type, u8 node, u64 cookie,
 429                                struct dlm_lockstatus *lksb)
 430 {
 431         struct dlm_lock *lock;
 432         int kernel_allocated = 0;
 433
 434         lock = kmem_cache_zalloc(dlm_lock_cache, GFP_NOFS);
 435         if (!lock)
 436                 return NULL;
 437
 438         if (!lksb) {
 439                 /* zero memory only if kernel-allocated */
 440                 lksb = kzalloc(sizeof(*lksb), GFP_NOFS);
 441                 if (!lksb) {
 442                         kfree(lock);
 443                         return NULL;
 444                 }
 445                 kernel_allocated = 1;
 446         }
 447
 448         dlm_init_lock(lock, type, node, cookie);
 449         if (kernel_allocated)
 450                 lock->lksb_kernel_allocated = 1;
 451         lock->lksb = lksb;
 452         lksb->lockid = lock;
 453         return lock;
 454 }
 455
 456 /* handler for lock creation net message
 457  * locking:
 458  *   caller needs:  none
 459  *   taken:         takes and drops res->spinlock
 460  *   held on exit:  none
 461  * returns: DLM_NORMAL, DLM_SYSERR, DLM_IVLOCKID, DLM_NOTQUEUED
 462  */
 463 int dlm_create_lock_handler(struct o2net_msg *msg, u32 len, void *data,
 464                             void **ret_data)
 465 {
 466         struct dlm_ctxt *dlm = data;
 467         struct dlm_create_lock *create = (struct dlm_create_lock *)msg->buf;
 468         struct dlm_lock_resource *res = NULL;
 469         struct dlm_lock *newlock = NULL;
 470         struct dlm_lockstatus *lksb = NULL;
 471         enum dlm_status status = DLM_NORMAL;
 472         char *name;
 473         unsigned int namelen;
 474
 475         BUG_ON(!dlm);
 476
 477         mlog_entry_void();
 478
 479         if (!dlm_grab(dlm))
 480                 return DLM_REJECTED;
 481
 482         name = create->name;
 483         namelen = create->namelen;
 484         status = DLM_REJECTED;
 485         if (!dlm_domain_fully_joined(dlm)) {
 486                 mlog(ML_ERROR, "Domain %s not fully joined, but node %u is "
 487                      "sending a create_lock message for lock %.*s!\n",
 488                      dlm->name, create->node_idx, namelen, name);
 489                 dlm_error(status);
 490                 goto leave;
 491         }
 492
 493         status = DLM_IVBUFLEN;
 494         if (namelen > DLM_LOCKID_NAME_MAX) {
 495                 dlm_error(status);
 496                 goto leave;
 497         }
 498
 499         status = DLM_SYSERR;
 500         newlock = dlm_new_lock(create->requested_type,
 501                                create->node_idx,
 502                                be64_to_cpu(create->cookie), NULL);
 503         if (!newlock) {
 504                 dlm_error(status);
 505                 goto leave;
 506         }
 507
 508         lksb = newlock->lksb;
 509
 510         if (be32_to_cpu(create->flags) & LKM_GET_LVB) {
 511                 lksb->flags |= DLM_LKSB_GET_LVB;
 512                 mlog(0, "set DLM_LKSB_GET_LVB flag\n");
 513         }
 514
 515         status = DLM_IVLOCKID;
 516         res = dlm_lookup_lockres(dlm, name, namelen);
 517         if (!res) {
 518                 dlm_error(status);
 519                 goto leave;
 520         }
 521
 522         spin_lock(&res->spinlock);
 523         status = __dlm_lockres_state_to_status(res);
 524         spin_unlock(&res->spinlock);
 525
 526         if (status != DLM_NORMAL) {
 527                 mlog(0, "lockres recovering/migrating/in-progress\n");
 528                 goto leave;
 529         }
 530
 531         dlm_lock_attach_lockres(newlock, res);
 532
 533         status = dlmlock_master(dlm, res, newlock, be32_to_cpu(create->flags));
 534 leave:
 535         if (status != DLM_NORMAL)
 536                 if (newlock)
 537                         dlm_lock_put(newlock);
 538
 539         if (res)
 540                 dlm_lockres_put(res);
 541
 542         dlm_put(dlm);
 543
 544         return status;
 545 }
 546
 547
 548 /* fetch next node-local (u8 nodenum + u56 cookie) into u64 */
 549 static inline void dlm_get_next_cookie(u8 node_num, u64 *cookie)
 550 {
 551         u64 tmpnode = node_num;
 552
 553         /* shift single byte of node num into top 8 bits */
 554         tmpnode <<= 56;
 555
 556         spin_lock(&dlm_cookie_lock);
 557         *cookie = (dlm_next_cookie | tmpnode);
 558         if (++dlm_next_cookie & 0xff00000000000000ull) {
 559                 mlog(0, "This node's cookie will now wrap!\n");
 560                 dlm_next_cookie = 1;
 561         }
 562         spin_unlock(&dlm_cookie_lock);
 563 }
 564
 565 enum dlm_status dlmlock(struct dlm_ctxt *dlm, int mode,
 566                         struct dlm_lockstatus *lksb, int flags,
 567                         const char *name, int namelen, dlm_astlockfunc_t *ast,
 568                         void *data, dlm_bastlockfunc_t *bast)
 569 {
 570         enum dlm_status status;
 571         struct dlm_lock_resource *res = NULL;
 572         struct dlm_lock *lock = NULL;
 573         int convert = 0, recovery = 0;
 574
 575         /* yes this function is a mess.
 576          * TODO: clean this up.  lots of common code in the
 577          *       lock and convert paths, especially in the retry blocks */
 578         if (!lksb) {
 579                 dlm_error(DLM_BADARGS);
 580                 return DLM_BADARGS;
 581         }
 582
 583         status = DLM_BADPARAM;
 584         if (mode != LKM_EXMODE && mode != LKM_PRMODE && mode != LKM_NLMODE) {
 585                 dlm_error(status);
 586                 goto error;
 587         }
 588
 589         if (flags & ~LKM_VALID_FLAGS) {
 590                 dlm_error(status);
 591                 goto error;
 592         }
 593
 594         convert = (flags & LKM_CONVERT);
 595         recovery = (flags & LKM_RECOVERY);
 596
 597         if (recovery &&
 598             (!dlm_is_recovery_lock(name, namelen) || convert) ) {
 599                 dlm_error(status);
 600                 goto error;
 601         }
 602         if (convert && (flags & LKM_LOCAL)) {
 603                 mlog(ML_ERROR, "strange LOCAL convert request!\n");
 604                 goto error;
 605         }
 606
 607         if (convert) {
 608                 /* CONVERT request */
 609
 610                 /* if converting, must pass in a valid dlm_lock */
 611                 lock = lksb->lockid;
 612                 if (!lock) {
 613                         mlog(ML_ERROR, "NULL lock pointer in convert "
 614                              "request\n");
 615                         goto error;
 616                 }
 617
 618                 res = lock->lockres;
 619                 if (!res) {
 620                         mlog(ML_ERROR, "NULL lockres pointer in convert "
 621                              "request\n");
 622                         goto error;
 623                 }
 624                 dlm_lockres_get(res);
 625
 626                 /* XXX: for ocfs2 purposes, the ast/bast/astdata/lksb are
 627                  * static after the original lock call.  convert requests will
 628                  * ensure that everything is the same, or return DLM_BADARGS.
 629                  * this means that DLM_DENIED_NOASTS will never be returned.
 630                  */
 631                 if (lock->lksb != lksb || lock->ast != ast ||
 632                     lock->bast != bast || lock->astdata != data) {
 633                         status = DLM_BADARGS;
 634                         mlog(ML_ERROR, "new args:  lksb=%p, ast=%p, bast=%p, "
 635                              "astdata=%p\n", lksb, ast, bast, data);
 636                         mlog(ML_ERROR, "orig args: lksb=%p, ast=%p, bast=%p, "
 637                              "astdata=%p\n", lock->lksb, lock->ast,
 638                              lock->bast, lock->astdata);
 639                         goto error;
 640                 }
 641 retry_convert:
 642                 dlm_wait_for_recovery(dlm);
 643
 644                 if (res->owner == dlm->node_num)
 645                         status = dlmconvert_master(dlm, res, lock, flags, mode);
 646                 else
 647                         status = dlmconvert_remote(dlm, res, lock, flags, mode);
 648                 if (status == DLM_RECOVERING || status == DLM_MIGRATING ||
 649                     status == DLM_FORWARD) {
 650                         /* for now, see how this works without sleeping
 651                          * and just retry right away.  I suspect the reco
 652                          * or migration will complete fast enough that
 653                          * no waiting will be necessary */
 654                         mlog(0, "retrying convert with migration/recovery/"
 655                              "in-progress\n");
 656                         msleep(100);
 657                         goto retry_convert;
 658                 }
 659         } else {
 660                 u64 tmpcookie;
 661
 662                 /* LOCK request */
 663                 status = DLM_BADARGS;
 664                 if (!name) {
 665                         dlm_error(status);
 666                         goto error;
 667                 }
 668
 669                 status = DLM_IVBUFLEN;
 670                 if (namelen > DLM_LOCKID_NAME_MAX || namelen < 1) {
 671                         dlm_error(status);
 672                         goto error;
 673                 }
 674
 675                 dlm_get_next_cookie(dlm->node_num, &tmpcookie);
 676                 lock = dlm_new_lock(mode, dlm->node_num, tmpcookie, lksb);
 677                 if (!lock) {
 678                         dlm_error(status);
 679                         goto error;
 680                 }
 681
 682                 if (!recovery)
 683                         dlm_wait_for_recovery(dlm);
 684
 685                 /* find or create the lock resource */
 686                 res = dlm_get_lock_resource(dlm, name, namelen, flags);
 687                 if (!res) {
 688                         status = DLM_IVLOCKID;
 689                         dlm_error(status);
 690                         goto error;
 691                 }
 692
 693                 mlog(0, "type=%d, flags = 0x%x\n", mode, flags);
 694                 mlog(0, "creating lock: lock=%p res=%p\n", lock, res);
 695
 696                 dlm_lock_attach_lockres(lock, res);
 697                 lock->ast = ast;
 698                 lock->bast = bast;
 699                 lock->astdata = data;
 700
 701 retry_lock:
 702                 if (flags & LKM_VALBLK) {
 703                         mlog(0, "LKM_VALBLK passed by caller\n");
 704
 705                         /* LVB requests for non PR, PW or EX locks are
 706                          * ignored. */
 707                         if (mode < LKM_PRMODE)
 708                                 flags &= ~LKM_VALBLK;
 709                         else {
 710                                 flags |= LKM_GET_LVB;
 711                                 lock->lksb->flags |= DLM_LKSB_GET_LVB;
 712                         }
 713                 }
 714
 715                 if (res->owner == dlm->node_num)
 716                         status = dlmlock_master(dlm, res, lock, flags);
 717                 else
 718                         status = dlmlock_remote(dlm, res, lock, flags);
 719
 720                 if (status == DLM_RECOVERING || status == DLM_MIGRATING ||
 721                     status == DLM_FORWARD) {
 722                         mlog(0, "retrying lock with migration/"
 723                              "recovery/in progress\n");
 724                         msleep(100);
 725                         /* no waiting for dlm_reco_thread */
 726                         if (recovery) {
 727                                 if (status != DLM_RECOVERING)
 728                                         goto retry_lock;
 729
 730                                 mlog(0, "%s: got RECOVERING "
 731                                      "for $RECOVERY lock, master "
 732                                      "was %u\n", dlm->name,
 733                                      res->owner);
 734                                 /* wait to see the node go down, then
 735                                  * drop down and allow the lockres to
 736                                  * get cleaned up.  need to remaster. */
 737                                 dlm_wait_for_node_death(dlm, res->owner,
 738                                                 DLM_NODE_DEATH_WAIT_MAX);
 739                         } else {
 740                                 dlm_wait_for_recovery(dlm);
 741                                 goto retry_lock;
 742                         }
 743                 }
 744
 745                 if (status != DLM_NORMAL) {
 746                         lock->lksb->flags &= ~DLM_LKSB_GET_LVB;
 747                         if (status != DLM_NOTQUEUED)
 748                                 dlm_error(status);
 749                         goto error;
 750                 }
 751         }
 752
 753 error:
 754         if (status != DLM_NORMAL) {
 755                 if (lock && !convert)
 756                         dlm_lock_put(lock);
 757                 // this is kind of unnecessary
 758                 lksb->status = status;
 759         }
 760
 761         /* put lockres ref from the convert path
 762          * or from dlm_get_lock_resource */
 763         if (res)
 764                 dlm_lockres_put(res);
 765
 766         return status;
 767 }
 768 EXPORT_SYMBOL_GPL(dlmlock);