git.oblomov.eu Git - linux-2.6/blob - fs/ocfs2/dlm/dlmlock.c

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * dlmlock.c
   5  *
   6  * underlying calls for lock creation
   7  *
   8  * Copyright (C) 2004 Oracle.  All rights reserved.
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public
  12  * License as published by the Free Software Foundation; either
  13  * version 2 of the License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public
  21  * License along with this program; if not, write to the
  22  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23  * Boston, MA 021110-1307, USA.
  24  *
  25  */
  26
  27
  28 #include <linux/module.h>
  29 #include <linux/fs.h>
  30 #include <linux/types.h>
  31 #include <linux/slab.h>
  32 #include <linux/highmem.h>
  33 #include <linux/utsname.h>
  34 #include <linux/init.h>
  35 #include <linux/sysctl.h>
  36 #include <linux/random.h>
  37 #include <linux/blkdev.h>
  38 #include <linux/socket.h>
  39 #include <linux/inet.h>
  40 #include <linux/spinlock.h>
  41 #include <linux/delay.h>
  42
  43
  44 #include "cluster/heartbeat.h"
  45 #include "cluster/nodemanager.h"
  46 #include "cluster/tcp.h"
  47
  48 #include "dlmapi.h"
  49 #include "dlmcommon.h"
  50
  51 #include "dlmconvert.h"
  52
  53 #define MLOG_MASK_PREFIX ML_DLM
  54 #include "cluster/masklog.h"
  55
  56 static struct kmem_cache *dlm_lock_cache = NULL;
  57
  58 static DEFINE_SPINLOCK(dlm_cookie_lock);
  59 static u64 dlm_next_cookie = 1;
  60
  61 static enum dlm_status dlm_send_remote_lock_request(struct dlm_ctxt *dlm,
  62                                                struct dlm_lock_resource *res,
  63                                                struct dlm_lock *lock, int flags);
  64 static void dlm_init_lock(struct dlm_lock *newlock, int type,
  65                           u8 node, u64 cookie);
  66 static void dlm_lock_release(struct kref *kref);
  67 static void dlm_lock_detach_lockres(struct dlm_lock *lock);
  68
  69 int dlm_init_lock_cache(void)
  70 {
  71         dlm_lock_cache = kmem_cache_create("o2dlm_lock",
  72                                            sizeof(struct dlm_lock),
  73                                            0, SLAB_HWCACHE_ALIGN, NULL);
  74         if (dlm_lock_cache == NULL)
  75                 return -ENOMEM;
  76         return 0;
  77 }
  78
  79 void dlm_destroy_lock_cache(void)
  80 {
  81         if (dlm_lock_cache)
  82                 kmem_cache_destroy(dlm_lock_cache);
  83 }
  84
  85 /* Tell us whether we can grant a new lock request.
  86  * locking:
  87  *   caller needs:  res->spinlock
  88  *   taken:         none
  89  *   held on exit:  none
  90  * returns: 1 if the lock can be granted, 0 otherwise.
  91  */
  92 static int dlm_can_grant_new_lock(struct dlm_lock_resource *res,
  93                                   struct dlm_lock *lock)
  94 {
  95         struct list_head *iter;
  96         struct dlm_lock *tmplock;
  97
  98         list_for_each(iter, &res->granted) {
  99                 tmplock = list_entry(iter, struct dlm_lock, list);
 100
 101                 if (!dlm_lock_compatible(tmplock->ml.type, lock->ml.type))
 102                         return 0;
 103         }
 104
 105         list_for_each(iter, &res->converting) {
 106                 tmplock = list_entry(iter, struct dlm_lock, list);
 107
 108                 if (!dlm_lock_compatible(tmplock->ml.type, lock->ml.type))
 109                         return 0;
 110         }
 111
 112         return 1;
 113 }
 114
 115 /* performs lock creation at the lockres master site
 116  * locking:
 117  *   caller needs:  none
 118  *   taken:         takes and drops res->spinlock
 119  *   held on exit:  none
 120  * returns: DLM_NORMAL, DLM_NOTQUEUED
 121  */
 122 static enum dlm_status dlmlock_master(struct dlm_ctxt *dlm,
 123                                       struct dlm_lock_resource *res,
 124                                       struct dlm_lock *lock, int flags)
 125 {
 126         int call_ast = 0, kick_thread = 0;
 127         enum dlm_status status = DLM_NORMAL;
 128
 129         mlog_entry("type=%d\n", lock->ml.type);
 130
 131         spin_lock(&res->spinlock);
 132         /* if called from dlm_create_lock_handler, need to
 133          * ensure it will not sleep in dlm_wait_on_lockres */
 134         status = __dlm_lockres_state_to_status(res);
 135         if (status != DLM_NORMAL &&
 136             lock->ml.node != dlm->node_num) {
 137                 /* erf.  state changed after lock was dropped. */
 138                 spin_unlock(&res->spinlock);
 139                 dlm_error(status);
 140                 return status;
 141         }
 142         __dlm_wait_on_lockres(res);
 143         __dlm_lockres_reserve_ast(res);
 144
 145         if (dlm_can_grant_new_lock(res, lock)) {
 146                 mlog(0, "I can grant this lock right away\n");
 147                 /* got it right away */
 148                 lock->lksb->status = DLM_NORMAL;
 149                 status = DLM_NORMAL;
 150                 dlm_lock_get(lock);
 151                 list_add_tail(&lock->list, &res->granted);
 152
 153                 /* for the recovery lock, we can't allow the ast
 154                  * to be queued since the dlmthread is already
 155                  * frozen.  but the recovery lock is always locked
 156                  * with LKM_NOQUEUE so we do not need the ast in
 157                  * this special case */
 158                 if (!dlm_is_recovery_lock(res->lockname.name,
 159                                           res->lockname.len)) {
 160                         kick_thread = 1;
 161                         call_ast = 1;
 162                 } else {
 163                         mlog(0, "%s: returning DLM_NORMAL to "
 164                              "node %u for reco lock\n", dlm->name,
 165                              lock->ml.node);
 166                 }
 167         } else {
 168                 /* for NOQUEUE request, unless we get the
 169                  * lock right away, return DLM_NOTQUEUED */
 170                 if (flags & LKM_NOQUEUE) {
 171                         status = DLM_NOTQUEUED;
 172                         if (dlm_is_recovery_lock(res->lockname.name,
 173                                                  res->lockname.len)) {
 174                                 mlog(0, "%s: returning NOTQUEUED to "
 175                                      "node %u for reco lock\n", dlm->name,
 176                                      lock->ml.node);
 177                         }
 178                 } else {
 179                         dlm_lock_get(lock);
 180                         list_add_tail(&lock->list, &res->blocked);
 181                         kick_thread = 1;
 182                 }
 183         }
 184         /* reduce the inflight count, this may result in the lockres
 185          * being purged below during calc_usage */
 186         if (lock->ml.node == dlm->node_num)
 187                 dlm_lockres_drop_inflight_ref(dlm, res);
 188
 189         spin_unlock(&res->spinlock);
 190         wake_up(&res->wq);
 191
 192         /* either queue the ast or release it */
 193         if (call_ast)
 194                 dlm_queue_ast(dlm, lock);
 195         else
 196                 dlm_lockres_release_ast(dlm, res);
 197
 198         dlm_lockres_calc_usage(dlm, res);
 199         if (kick_thread)
 200                 dlm_kick_thread(dlm, res);
 201
 202         return status;
 203 }
 204
 205 void dlm_revert_pending_lock(struct dlm_lock_resource *res,
 206                              struct dlm_lock *lock)
 207 {
 208         /* remove from local queue if it failed */
 209         list_del_init(&lock->list);
 210         lock->lksb->flags &= ~DLM_LKSB_GET_LVB;
 211 }
 212
 213
 214 /*
 215  * locking:
 216  *   caller needs:  none
 217  *   taken:         takes and drops res->spinlock
 218  *   held on exit:  none
 219  * returns: DLM_DENIED, DLM_RECOVERING, or net status
 220  */
 221 static enum dlm_status dlmlock_remote(struct dlm_ctxt *dlm,
 222                                       struct dlm_lock_resource *res,
 223                                       struct dlm_lock *lock, int flags)
 224 {
 225         enum dlm_status status = DLM_DENIED;
 226         int lockres_changed = 1;
 227
 228         mlog_entry("type=%d\n", lock->ml.type);
 229         mlog(0, "lockres %.*s, flags = 0x%x\n", res->lockname.len,
 230              res->lockname.name, flags);
 231
 232         spin_lock(&res->spinlock);
 233
 234         /* will exit this call with spinlock held */
 235         __dlm_wait_on_lockres(res);
 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         mlog_entry_void();
 310
 311         memset(&create, 0, sizeof(create));
 312         create.node_idx = dlm->node_num;
 313         create.requested_type = lock->ml.type;
 314         create.cookie = lock->ml.cookie;
 315         create.namelen = res->lockname.len;
 316         create.flags = cpu_to_be32(flags);
 317         memcpy(create.name, res->lockname.name, create.namelen);
 318
 319         tmpret = o2net_send_message(DLM_CREATE_LOCK_MSG, dlm->key, &create,
 320                                     sizeof(create), res->owner, &status);
 321         if (tmpret >= 0) {
 322                 // successfully sent and received
 323                 ret = status;  // this is already a dlm_status
 324                 if (ret == DLM_REJECTED) {
 325                         mlog(ML_ERROR, "%s:%.*s: BUG.  this is a stale lockres "
 326                              "no longer owned by %u.  that node is coming back "
 327                              "up currently.\n", dlm->name, create.namelen,
 328                              create.name, res->owner);
 329                         dlm_print_one_lock_resource(res);
 330                         BUG();
 331                 }
 332         } else {
 333                 mlog_errno(tmpret);
 334                 if (dlm_is_host_down(tmpret)) {
 335                         ret = DLM_RECOVERING;
 336                         mlog(0, "node %u died so returning DLM_RECOVERING "
 337                              "from lock message!\n", res->owner);
 338                 } else {
 339                         ret = dlm_err_to_dlm_status(tmpret);
 340                 }
 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 = (struct dlm_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                         kfree(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         mlog_entry_void();
 477
 478         if (!dlm_grab(dlm))
 479                 return DLM_REJECTED;
 480
 481         name = create->name;
 482         namelen = create->namelen;
 483         status = DLM_REJECTED;
 484         if (!dlm_domain_fully_joined(dlm)) {
 485                 mlog(ML_ERROR, "Domain %s not fully joined, but node %u is "
 486                      "sending a create_lock message for lock %.*s!\n",
 487                      dlm->name, create->node_idx, namelen, name);
 488                 dlm_error(status);
 489                 goto leave;
 490         }
 491
 492         status = DLM_IVBUFLEN;
 493         if (namelen > DLM_LOCKID_NAME_MAX) {
 494                 dlm_error(status);
 495                 goto leave;
 496         }
 497
 498         status = DLM_SYSERR;
 499         newlock = dlm_new_lock(create->requested_type,
 500                                create->node_idx,
 501                                be64_to_cpu(create->cookie), NULL);
 502         if (!newlock) {
 503                 dlm_error(status);
 504                 goto leave;
 505         }
 506
 507         lksb = newlock->lksb;
 508
 509         if (be32_to_cpu(create->flags) & LKM_GET_LVB) {
 510                 lksb->flags |= DLM_LKSB_GET_LVB;
 511                 mlog(0, "set DLM_LKSB_GET_LVB flag\n");
 512         }
 513
 514         status = DLM_IVLOCKID;
 515         res = dlm_lookup_lockres(dlm, name, namelen);
 516         if (!res) {
 517                 dlm_error(status);
 518                 goto leave;
 519         }
 520
 521         spin_lock(&res->spinlock);
 522         status = __dlm_lockres_state_to_status(res);
 523         spin_unlock(&res->spinlock);
 524
 525         if (status != DLM_NORMAL) {
 526                 mlog(0, "lockres recovering/migrating/in-progress\n");
 527                 goto leave;
 528         }
 529
 530         dlm_lock_attach_lockres(newlock, res);
 531
 532         status = dlmlock_master(dlm, res, newlock, be32_to_cpu(create->flags));
 533 leave:
 534         if (status != DLM_NORMAL)
 535                 if (newlock)
 536                         dlm_lock_put(newlock);
 537
 538         if (res)
 539                 dlm_lockres_put(res);
 540
 541         dlm_put(dlm);
 542
 543         return status;
 544 }
 545
 546
 547 /* fetch next node-local (u8 nodenum + u56 cookie) into u64 */
 548 static inline void dlm_get_next_cookie(u8 node_num, u64 *cookie)
 549 {
 550         u64 tmpnode = node_num;
 551
 552         /* shift single byte of node num into top 8 bits */
 553         tmpnode <<= 56;
 554
 555         spin_lock(&dlm_cookie_lock);
 556         *cookie = (dlm_next_cookie | tmpnode);
 557         if (++dlm_next_cookie & 0xff00000000000000ull) {
 558                 mlog(0, "This node's cookie will now wrap!\n");
 559                 dlm_next_cookie = 1;
 560         }
 561         spin_unlock(&dlm_cookie_lock);
 562 }
 563
 564 enum dlm_status dlmlock(struct dlm_ctxt *dlm, int mode,
 565                         struct dlm_lockstatus *lksb, int flags,
 566                         const char *name, int namelen, dlm_astlockfunc_t *ast,
 567                         void *data, dlm_bastlockfunc_t *bast)
 568 {
 569         enum dlm_status status;
 570         struct dlm_lock_resource *res = NULL;
 571         struct dlm_lock *lock = NULL;
 572         int convert = 0, recovery = 0;
 573
 574         /* yes this function is a mess.
 575          * TODO: clean this up.  lots of common code in the
 576          *       lock and convert paths, especially in the retry blocks */
 577         if (!lksb) {
 578                 dlm_error(DLM_BADARGS);
 579                 return DLM_BADARGS;
 580         }
 581
 582         status = DLM_BADPARAM;
 583         if (mode != LKM_EXMODE && mode != LKM_PRMODE && mode != LKM_NLMODE) {
 584                 dlm_error(status);
 585                 goto error;
 586         }
 587
 588         if (flags & ~LKM_VALID_FLAGS) {
 589                 dlm_error(status);
 590                 goto error;
 591         }
 592
 593         convert = (flags & LKM_CONVERT);
 594         recovery = (flags & LKM_RECOVERY);
 595
 596         if (recovery &&
 597             (!dlm_is_recovery_lock(name, namelen) || convert) ) {
 598                 dlm_error(status);
 599                 goto error;
 600         }
 601         if (convert && (flags & LKM_LOCAL)) {
 602                 mlog(ML_ERROR, "strange LOCAL convert request!\n");
 603                 goto error;
 604         }
 605
 606         if (convert) {
 607                 /* CONVERT request */
 608
 609                 /* if converting, must pass in a valid dlm_lock */
 610                 lock = lksb->lockid;
 611                 if (!lock) {
 612                         mlog(ML_ERROR, "NULL lock pointer in convert "
 613                              "request\n");
 614                         goto error;
 615                 }
 616
 617                 res = lock->lockres;
 618                 if (!res) {
 619                         mlog(ML_ERROR, "NULL lockres pointer in convert "
 620                              "request\n");
 621                         goto error;
 622                 }
 623                 dlm_lockres_get(res);
 624
 625                 /* XXX: for ocfs2 purposes, the ast/bast/astdata/lksb are
 626                  * static after the original lock call.  convert requests will
 627                  * ensure that everything is the same, or return DLM_BADARGS.
 628                  * this means that DLM_DENIED_NOASTS will never be returned.
 629                  */
 630                 if (lock->lksb != lksb || lock->ast != ast ||
 631                     lock->bast != bast || lock->astdata != data) {
 632                         status = DLM_BADARGS;
 633                         mlog(ML_ERROR, "new args:  lksb=%p, ast=%p, bast=%p, "
 634                              "astdata=%p\n", lksb, ast, bast, data);
 635                         mlog(ML_ERROR, "orig args: lksb=%p, ast=%p, bast=%p, "
 636                              "astdata=%p\n", lock->lksb, lock->ast,
 637                              lock->bast, lock->astdata);
 638                         goto error;
 639                 }
 640 retry_convert:
 641                 dlm_wait_for_recovery(dlm);
 642
 643                 if (res->owner == dlm->node_num)
 644                         status = dlmconvert_master(dlm, res, lock, flags, mode);
 645                 else
 646                         status = dlmconvert_remote(dlm, res, lock, flags, mode);
 647                 if (status == DLM_RECOVERING || status == DLM_MIGRATING ||
 648                     status == DLM_FORWARD) {
 649                         /* for now, see how this works without sleeping
 650                          * and just retry right away.  I suspect the reco
 651                          * or migration will complete fast enough that
 652                          * no waiting will be necessary */
 653                         mlog(0, "retrying convert with migration/recovery/"
 654                              "in-progress\n");
 655                         msleep(100);
 656                         goto retry_convert;
 657                 }
 658         } else {
 659                 u64 tmpcookie;
 660
 661                 /* LOCK request */
 662                 status = DLM_BADARGS;
 663                 if (!name) {
 664                         dlm_error(status);
 665                         goto error;
 666                 }
 667
 668                 status = DLM_IVBUFLEN;
 669                 if (namelen > DLM_LOCKID_NAME_MAX || namelen < 1) {
 670                         dlm_error(status);
 671                         goto error;
 672                 }
 673
 674                 dlm_get_next_cookie(dlm->node_num, &tmpcookie);
 675                 lock = dlm_new_lock(mode, dlm->node_num, tmpcookie, lksb);
 676                 if (!lock) {
 677                         dlm_error(status);
 678                         goto error;
 679                 }
 680
 681                 if (!recovery)
 682                         dlm_wait_for_recovery(dlm);
 683
 684                 /* find or create the lock resource */
 685                 res = dlm_get_lock_resource(dlm, name, namelen, flags);
 686                 if (!res) {
 687                         status = DLM_IVLOCKID;
 688                         dlm_error(status);
 689                         goto error;
 690                 }
 691
 692                 mlog(0, "type=%d, flags = 0x%x\n", mode, flags);
 693                 mlog(0, "creating lock: lock=%p res=%p\n", lock, res);
 694
 695                 dlm_lock_attach_lockres(lock, res);
 696                 lock->ast = ast;
 697                 lock->bast = bast;
 698                 lock->astdata = data;
 699
 700 retry_lock:
 701                 if (flags & LKM_VALBLK) {
 702                         mlog(0, "LKM_VALBLK passed by caller\n");
 703
 704                         /* LVB requests for non PR, PW or EX locks are
 705                          * ignored. */
 706                         if (mode < LKM_PRMODE)
 707                                 flags &= ~LKM_VALBLK;
 708                         else {
 709                                 flags |= LKM_GET_LVB;
 710                                 lock->lksb->flags |= DLM_LKSB_GET_LVB;
 711                         }
 712                 }
 713
 714                 if (res->owner == dlm->node_num)
 715                         status = dlmlock_master(dlm, res, lock, flags);
 716                 else
 717                         status = dlmlock_remote(dlm, res, lock, flags);
 718
 719                 if (status == DLM_RECOVERING || status == DLM_MIGRATING ||
 720                     status == DLM_FORWARD) {
 721                         mlog(0, "retrying lock with migration/"
 722                              "recovery/in progress\n");
 723                         msleep(100);
 724                         /* no waiting for dlm_reco_thread */
 725                         if (recovery) {
 726                                 if (status != DLM_RECOVERING)
 727                                         goto retry_lock;
 728
 729                                 mlog(0, "%s: got RECOVERING "
 730                                      "for $RECOVERY lock, master "
 731                                      "was %u\n", dlm->name,
 732                                      res->owner);
 733                                 /* wait to see the node go down, then
 734                                  * drop down and allow the lockres to
 735                                  * get cleaned up.  need to remaster. */
 736                                 dlm_wait_for_node_death(dlm, res->owner,
 737                                                 DLM_NODE_DEATH_WAIT_MAX);
 738                         } else {
 739                                 dlm_wait_for_recovery(dlm);
 740                                 goto retry_lock;
 741                         }
 742                 }
 743
 744                 if (status != DLM_NORMAL) {
 745                         lock->lksb->flags &= ~DLM_LKSB_GET_LVB;
 746                         if (status != DLM_NOTQUEUED)
 747                                 dlm_error(status);
 748                         goto error;
 749                 }
 750         }
 751
 752 error:
 753         if (status != DLM_NORMAL) {
 754                 if (lock && !convert)
 755                         dlm_lock_put(lock);
 756                 // this is kind of unnecessary
 757                 lksb->status = status;
 758         }
 759
 760         /* put lockres ref from the convert path
 761          * or from dlm_get_lock_resource */
 762         if (res)
 763                 dlm_lockres_put(res);
 764
 765         return status;
 766 }
 767 EXPORT_SYMBOL_GPL(dlmlock);