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