1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* -*- mode: c; c-basic-offset: 8; -*- 3 * vim: noexpandtab sw=8 ts=8 sts=0: 4 * 5 * dlmunlock.c 6 * 7 * underlying calls for unlocking locks 8 * 9 * Copyright (C) 2004 Oracle. All rights reserved. 10 */ 11 12 13 #include <linux/module.h> 14 #include <linux/fs.h> 15 #include <linux/types.h> 16 #include <linux/highmem.h> 17 #include <linux/init.h> 18 #include <linux/sysctl.h> 19 #include <linux/random.h> 20 #include <linux/blkdev.h> 21 #include <linux/socket.h> 22 #include <linux/inet.h> 23 #include <linux/spinlock.h> 24 #include <linux/delay.h> 25 26 #include "cluster/heartbeat.h" 27 #include "cluster/nodemanager.h" 28 #include "cluster/tcp.h" 29 30 #include "dlmapi.h" 31 #include "dlmcommon.h" 32 33 #define MLOG_MASK_PREFIX ML_DLM 34 #include "cluster/masklog.h" 35 36 #define DLM_UNLOCK_FREE_LOCK 0x00000001 37 #define DLM_UNLOCK_CALL_AST 0x00000002 38 #define DLM_UNLOCK_REMOVE_LOCK 0x00000004 39 #define DLM_UNLOCK_REGRANT_LOCK 0x00000008 40 #define DLM_UNLOCK_CLEAR_CONVERT_TYPE 0x00000010 41 42 43 static enum dlm_status dlm_get_cancel_actions(struct dlm_ctxt *dlm, 44 struct dlm_lock_resource *res, 45 struct dlm_lock *lock, 46 struct dlm_lockstatus *lksb, 47 int *actions); 48 static enum dlm_status dlm_get_unlock_actions(struct dlm_ctxt *dlm, 49 struct dlm_lock_resource *res, 50 struct dlm_lock *lock, 51 struct dlm_lockstatus *lksb, 52 int *actions); 53 54 static enum dlm_status dlm_send_remote_unlock_request(struct dlm_ctxt *dlm, 55 struct dlm_lock_resource *res, 56 struct dlm_lock *lock, 57 struct dlm_lockstatus *lksb, 58 int flags, 59 u8 owner); 60 61 62 /* 63 * according to the spec: 64 * http://opendlm.sourceforge.net/cvsmirror/opendlm/docs/dlmbook_final.pdf 65 * 66 * flags & LKM_CANCEL != 0: must be converting or blocked 67 * flags & LKM_CANCEL == 0: must be granted 68 * 69 * So to unlock a converting lock, you must first cancel the 70 * convert (passing LKM_CANCEL in flags), then call the unlock 71 * again (with no LKM_CANCEL in flags). 72 */ 73 74 75 /* 76 * locking: 77 * caller needs: none 78 * taken: res->spinlock and lock->spinlock taken and dropped 79 * held on exit: none 80 * returns: DLM_NORMAL, DLM_NOLOCKMGR, status from network 81 * all callers should have taken an extra ref on lock coming in 82 */ 83 static enum dlm_status dlmunlock_common(struct dlm_ctxt *dlm, 84 struct dlm_lock_resource *res, 85 struct dlm_lock *lock, 86 struct dlm_lockstatus *lksb, 87 int flags, int *call_ast, 88 int master_node) 89 { 90 enum dlm_status status; 91 int actions = 0; 92 int in_use; 93 u8 owner; 94 int recovery_wait = 0; 95 96 mlog(0, "master_node = %d, valblk = %d\n", master_node, 97 flags & LKM_VALBLK); 98 99 if (master_node) 100 BUG_ON(res->owner != dlm->node_num); 101 else 102 BUG_ON(res->owner == dlm->node_num); 103 104 spin_lock(&dlm->ast_lock); 105 /* We want to be sure that we're not freeing a lock 106 * that still has AST's pending... */ 107 in_use = !list_empty(&lock->ast_list); 108 spin_unlock(&dlm->ast_lock); 109 if (in_use && !(flags & LKM_CANCEL)) { 110 mlog(ML_ERROR, "lockres %.*s: Someone is calling dlmunlock " 111 "while waiting for an ast!", res->lockname.len, 112 res->lockname.name); 113 return DLM_BADPARAM; 114 } 115 116 spin_lock(&res->spinlock); 117 if (res->state & DLM_LOCK_RES_IN_PROGRESS) { 118 if (master_node && !(flags & LKM_CANCEL)) { 119 mlog(ML_ERROR, "lockres in progress!\n"); 120 spin_unlock(&res->spinlock); 121 return DLM_FORWARD; 122 } 123 /* ok for this to sleep if not in a network handler */ 124 __dlm_wait_on_lockres(res); 125 res->state |= DLM_LOCK_RES_IN_PROGRESS; 126 } 127 spin_lock(&lock->spinlock); 128 129 if (res->state & DLM_LOCK_RES_RECOVERING) { 130 status = DLM_RECOVERING; 131 goto leave; 132 } 133 134 if (res->state & DLM_LOCK_RES_MIGRATING) { 135 status = DLM_MIGRATING; 136 goto leave; 137 } 138 139 /* see above for what the spec says about 140 * LKM_CANCEL and the lock queue state */ 141 if (flags & LKM_CANCEL) 142 status = dlm_get_cancel_actions(dlm, res, lock, lksb, &actions); 143 else 144 status = dlm_get_unlock_actions(dlm, res, lock, lksb, &actions); 145 146 if (status != DLM_NORMAL && (status != DLM_CANCELGRANT || !master_node)) 147 goto leave; 148 149 /* By now this has been masked out of cancel requests. */ 150 if (flags & LKM_VALBLK) { 151 /* make the final update to the lvb */ 152 if (master_node) 153 memcpy(res->lvb, lksb->lvb, DLM_LVB_LEN); 154 else 155 flags |= LKM_PUT_LVB; /* let the send function 156 * handle it. */ 157 } 158 159 if (!master_node) { 160 owner = res->owner; 161 /* drop locks and send message */ 162 if (flags & LKM_CANCEL) 163 lock->cancel_pending = 1; 164 else 165 lock->unlock_pending = 1; 166 spin_unlock(&lock->spinlock); 167 spin_unlock(&res->spinlock); 168 status = dlm_send_remote_unlock_request(dlm, res, lock, lksb, 169 flags, owner); 170 spin_lock(&res->spinlock); 171 spin_lock(&lock->spinlock); 172 /* if the master told us the lock was already granted, 173 * let the ast handle all of these actions */ 174 if (status == DLM_CANCELGRANT) { 175 actions &= ~(DLM_UNLOCK_REMOVE_LOCK| 176 DLM_UNLOCK_REGRANT_LOCK| 177 DLM_UNLOCK_CLEAR_CONVERT_TYPE); 178 } else if (status == DLM_RECOVERING || 179 status == DLM_MIGRATING || 180 status == DLM_FORWARD || 181 status == DLM_NOLOCKMGR 182 ) { 183 /* must clear the actions because this unlock 184 * is about to be retried. cannot free or do 185 * any list manipulation. */ 186 mlog(0, "%s:%.*s: clearing actions, %s\n", 187 dlm->name, res->lockname.len, 188 res->lockname.name, 189 status==DLM_RECOVERING?"recovering": 190 (status==DLM_MIGRATING?"migrating": 191 (status == DLM_FORWARD ? "forward" : 192 "nolockmanager"))); 193 actions = 0; 194 } 195 if (flags & LKM_CANCEL) 196 lock->cancel_pending = 0; 197 else { 198 if (!lock->unlock_pending) 199 recovery_wait = 1; 200 else 201 lock->unlock_pending = 0; 202 } 203 } 204 205 /* get an extra ref on lock. if we are just switching 206 * lists here, we dont want the lock to go away. */ 207 dlm_lock_get(lock); 208 209 if (actions & DLM_UNLOCK_REMOVE_LOCK) { 210 list_del_init(&lock->list); 211 dlm_lock_put(lock); 212 } 213 if (actions & DLM_UNLOCK_REGRANT_LOCK) { 214 dlm_lock_get(lock); 215 list_add_tail(&lock->list, &res->granted); 216 } 217 if (actions & DLM_UNLOCK_CLEAR_CONVERT_TYPE) { 218 mlog(0, "clearing convert_type at %smaster node\n", 219 master_node ? "" : "non-"); 220 lock->ml.convert_type = LKM_IVMODE; 221 } 222 223 /* remove the extra ref on lock */ 224 dlm_lock_put(lock); 225 226 leave: 227 res->state &= ~DLM_LOCK_RES_IN_PROGRESS; 228 if (!dlm_lock_on_list(&res->converting, lock)) 229 BUG_ON(lock->ml.convert_type != LKM_IVMODE); 230 else 231 BUG_ON(lock->ml.convert_type == LKM_IVMODE); 232 spin_unlock(&lock->spinlock); 233 spin_unlock(&res->spinlock); 234 wake_up(&res->wq); 235 236 if (recovery_wait) { 237 spin_lock(&res->spinlock); 238 /* Unlock request will directly succeed after owner dies, 239 * and the lock is already removed from grant list. We have to 240 * wait for RECOVERING done or we miss the chance to purge it 241 * since the removement is much faster than RECOVERING proc. 242 */ 243 __dlm_wait_on_lockres_flags(res, DLM_LOCK_RES_RECOVERING); 244 spin_unlock(&res->spinlock); 245 } 246 247 /* let the caller's final dlm_lock_put handle the actual kfree */ 248 if (actions & DLM_UNLOCK_FREE_LOCK) { 249 /* this should always be coupled with list removal */ 250 BUG_ON(!(actions & DLM_UNLOCK_REMOVE_LOCK)); 251 mlog(0, "lock %u:%llu should be gone now! refs=%d\n", 252 dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)), 253 dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)), 254 kref_read(&lock->lock_refs)-1); 255 dlm_lock_put(lock); 256 } 257 if (actions & DLM_UNLOCK_CALL_AST) 258 *call_ast = 1; 259 260 /* if cancel or unlock succeeded, lvb work is done */ 261 if (status == DLM_NORMAL) 262 lksb->flags &= ~(DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB); 263 264 return status; 265 } 266 267 void dlm_commit_pending_unlock(struct dlm_lock_resource *res, 268 struct dlm_lock *lock) 269 { 270 /* leave DLM_LKSB_PUT_LVB on the lksb so any final 271 * update of the lvb will be sent to the new master */ 272 list_del_init(&lock->list); 273 } 274 275 void dlm_commit_pending_cancel(struct dlm_lock_resource *res, 276 struct dlm_lock *lock) 277 { 278 list_move_tail(&lock->list, &res->granted); 279 lock->ml.convert_type = LKM_IVMODE; 280 } 281 282 283 static inline enum dlm_status dlmunlock_master(struct dlm_ctxt *dlm, 284 struct dlm_lock_resource *res, 285 struct dlm_lock *lock, 286 struct dlm_lockstatus *lksb, 287 int flags, 288 int *call_ast) 289 { 290 return dlmunlock_common(dlm, res, lock, lksb, flags, call_ast, 1); 291 } 292 293 static inline enum dlm_status dlmunlock_remote(struct dlm_ctxt *dlm, 294 struct dlm_lock_resource *res, 295 struct dlm_lock *lock, 296 struct dlm_lockstatus *lksb, 297 int flags, int *call_ast) 298 { 299 return dlmunlock_common(dlm, res, lock, lksb, flags, call_ast, 0); 300 } 301 302 /* 303 * locking: 304 * caller needs: none 305 * taken: none 306 * held on exit: none 307 * returns: DLM_NORMAL, DLM_NOLOCKMGR, status from network 308 */ 309 static enum dlm_status dlm_send_remote_unlock_request(struct dlm_ctxt *dlm, 310 struct dlm_lock_resource *res, 311 struct dlm_lock *lock, 312 struct dlm_lockstatus *lksb, 313 int flags, 314 u8 owner) 315 { 316 struct dlm_unlock_lock unlock; 317 int tmpret; 318 enum dlm_status ret; 319 int status = 0; 320 struct kvec vec[2]; 321 size_t veclen = 1; 322 323 mlog(0, "%.*s\n", res->lockname.len, res->lockname.name); 324 325 if (owner == dlm->node_num) { 326 /* ended up trying to contact ourself. this means 327 * that the lockres had been remote but became local 328 * via a migration. just retry it, now as local */ 329 mlog(0, "%s:%.*s: this node became the master due to a " 330 "migration, re-evaluate now\n", dlm->name, 331 res->lockname.len, res->lockname.name); 332 return DLM_FORWARD; 333 } 334 335 memset(&unlock, 0, sizeof(unlock)); 336 unlock.node_idx = dlm->node_num; 337 unlock.flags = cpu_to_be32(flags); 338 unlock.cookie = lock->ml.cookie; 339 unlock.namelen = res->lockname.len; 340 memcpy(unlock.name, res->lockname.name, unlock.namelen); 341 342 vec[0].iov_len = sizeof(struct dlm_unlock_lock); 343 vec[0].iov_base = &unlock; 344 345 if (flags & LKM_PUT_LVB) { 346 /* extra data to send if we are updating lvb */ 347 vec[1].iov_len = DLM_LVB_LEN; 348 vec[1].iov_base = lock->lksb->lvb; 349 veclen++; 350 } 351 352 tmpret = o2net_send_message_vec(DLM_UNLOCK_LOCK_MSG, dlm->key, 353 vec, veclen, owner, &status); 354 if (tmpret >= 0) { 355 // successfully sent and received 356 if (status == DLM_FORWARD) 357 mlog(0, "master was in-progress. retry\n"); 358 ret = status; 359 } else { 360 mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to " 361 "node %u\n", tmpret, DLM_UNLOCK_LOCK_MSG, dlm->key, owner); 362 if (dlm_is_host_down(tmpret)) { 363 /* NOTE: this seems strange, but it is what we want. 364 * when the master goes down during a cancel or 365 * unlock, the recovery code completes the operation 366 * as if the master had not died, then passes the 367 * updated state to the recovery master. this thread 368 * just needs to finish out the operation and call 369 * the unlockast. */ 370 if (dlm_is_node_dead(dlm, owner)) 371 ret = DLM_NORMAL; 372 else 373 ret = DLM_NOLOCKMGR; 374 } else { 375 /* something bad. this will BUG in ocfs2 */ 376 ret = dlm_err_to_dlm_status(tmpret); 377 } 378 } 379 380 return ret; 381 } 382 383 /* 384 * locking: 385 * caller needs: none 386 * taken: takes and drops res->spinlock 387 * held on exit: none 388 * returns: DLM_NORMAL, DLM_BADARGS, DLM_IVLOCKID, 389 * return value from dlmunlock_master 390 */ 391 int dlm_unlock_lock_handler(struct o2net_msg *msg, u32 len, void *data, 392 void **ret_data) 393 { 394 struct dlm_ctxt *dlm = data; 395 struct dlm_unlock_lock *unlock = (struct dlm_unlock_lock *)msg->buf; 396 struct dlm_lock_resource *res = NULL; 397 struct dlm_lock *lock = NULL; 398 enum dlm_status status = DLM_NORMAL; 399 int found = 0, i; 400 struct dlm_lockstatus *lksb = NULL; 401 int ignore; 402 u32 flags; 403 struct list_head *queue; 404 405 flags = be32_to_cpu(unlock->flags); 406 407 if (flags & LKM_GET_LVB) { 408 mlog(ML_ERROR, "bad args! GET_LVB specified on unlock!\n"); 409 return DLM_BADARGS; 410 } 411 412 if ((flags & (LKM_PUT_LVB|LKM_CANCEL)) == (LKM_PUT_LVB|LKM_CANCEL)) { 413 mlog(ML_ERROR, "bad args! cannot modify lvb on a CANCEL " 414 "request!\n"); 415 return DLM_BADARGS; 416 } 417 418 if (unlock->namelen > DLM_LOCKID_NAME_MAX) { 419 mlog(ML_ERROR, "Invalid name length in unlock handler!\n"); 420 return DLM_IVBUFLEN; 421 } 422 423 if (!dlm_grab(dlm)) 424 return DLM_FORWARD; 425 426 mlog_bug_on_msg(!dlm_domain_fully_joined(dlm), 427 "Domain %s not fully joined!\n", dlm->name); 428 429 mlog(0, "lvb: %s\n", flags & LKM_PUT_LVB ? "put lvb" : "none"); 430 431 res = dlm_lookup_lockres(dlm, unlock->name, unlock->namelen); 432 if (!res) { 433 /* We assume here that a no lock resource simply means 434 * it was migrated away and destroyed before the other 435 * node could detect it. */ 436 mlog(0, "returning DLM_FORWARD -- res no longer exists\n"); 437 status = DLM_FORWARD; 438 goto not_found; 439 } 440 441 queue=&res->granted; 442 found = 0; 443 spin_lock(&res->spinlock); 444 if (res->state & DLM_LOCK_RES_RECOVERING) { 445 spin_unlock(&res->spinlock); 446 mlog(0, "returning DLM_RECOVERING\n"); 447 status = DLM_RECOVERING; 448 goto leave; 449 } 450 451 if (res->state & DLM_LOCK_RES_MIGRATING) { 452 spin_unlock(&res->spinlock); 453 mlog(0, "returning DLM_MIGRATING\n"); 454 status = DLM_MIGRATING; 455 goto leave; 456 } 457 458 if (res->owner != dlm->node_num) { 459 spin_unlock(&res->spinlock); 460 mlog(0, "returning DLM_FORWARD -- not master\n"); 461 status = DLM_FORWARD; 462 goto leave; 463 } 464 465 for (i=0; i<3; i++) { 466 list_for_each_entry(lock, queue, list) { 467 if (lock->ml.cookie == unlock->cookie && 468 lock->ml.node == unlock->node_idx) { 469 dlm_lock_get(lock); 470 found = 1; 471 break; 472 } 473 } 474 if (found) 475 break; 476 /* scan granted -> converting -> blocked queues */ 477 queue++; 478 } 479 spin_unlock(&res->spinlock); 480 if (!found) { 481 status = DLM_IVLOCKID; 482 goto not_found; 483 } 484 485 /* lock was found on queue */ 486 lksb = lock->lksb; 487 if (flags & (LKM_VALBLK|LKM_PUT_LVB) && 488 lock->ml.type != LKM_EXMODE) 489 flags &= ~(LKM_VALBLK|LKM_PUT_LVB); 490 491 /* unlockast only called on originating node */ 492 if (flags & LKM_PUT_LVB) { 493 lksb->flags |= DLM_LKSB_PUT_LVB; 494 memcpy(&lksb->lvb[0], &unlock->lvb[0], DLM_LVB_LEN); 495 } 496 497 /* if this is in-progress, propagate the DLM_FORWARD 498 * all the way back out */ 499 status = dlmunlock_master(dlm, res, lock, lksb, flags, &ignore); 500 if (status == DLM_FORWARD) 501 mlog(0, "lockres is in progress\n"); 502 503 if (flags & LKM_PUT_LVB) 504 lksb->flags &= ~DLM_LKSB_PUT_LVB; 505 506 dlm_lockres_calc_usage(dlm, res); 507 dlm_kick_thread(dlm, res); 508 509 not_found: 510 if (!found) 511 mlog(ML_ERROR, "failed to find lock to unlock! " 512 "cookie=%u:%llu\n", 513 dlm_get_lock_cookie_node(be64_to_cpu(unlock->cookie)), 514 dlm_get_lock_cookie_seq(be64_to_cpu(unlock->cookie))); 515 else 516 dlm_lock_put(lock); 517 518 leave: 519 if (res) 520 dlm_lockres_put(res); 521 522 dlm_put(dlm); 523 524 return status; 525 } 526 527 528 static enum dlm_status dlm_get_cancel_actions(struct dlm_ctxt *dlm, 529 struct dlm_lock_resource *res, 530 struct dlm_lock *lock, 531 struct dlm_lockstatus *lksb, 532 int *actions) 533 { 534 enum dlm_status status; 535 536 if (dlm_lock_on_list(&res->blocked, lock)) { 537 /* cancel this outright */ 538 status = DLM_NORMAL; 539 *actions = (DLM_UNLOCK_CALL_AST | 540 DLM_UNLOCK_REMOVE_LOCK); 541 } else if (dlm_lock_on_list(&res->converting, lock)) { 542 /* cancel the request, put back on granted */ 543 status = DLM_NORMAL; 544 *actions = (DLM_UNLOCK_CALL_AST | 545 DLM_UNLOCK_REMOVE_LOCK | 546 DLM_UNLOCK_REGRANT_LOCK | 547 DLM_UNLOCK_CLEAR_CONVERT_TYPE); 548 } else if (dlm_lock_on_list(&res->granted, lock)) { 549 /* too late, already granted. */ 550 status = DLM_CANCELGRANT; 551 *actions = DLM_UNLOCK_CALL_AST; 552 } else { 553 mlog(ML_ERROR, "lock to cancel is not on any list!\n"); 554 status = DLM_IVLOCKID; 555 *actions = 0; 556 } 557 return status; 558 } 559 560 static enum dlm_status dlm_get_unlock_actions(struct dlm_ctxt *dlm, 561 struct dlm_lock_resource *res, 562 struct dlm_lock *lock, 563 struct dlm_lockstatus *lksb, 564 int *actions) 565 { 566 enum dlm_status status; 567 568 /* unlock request */ 569 if (!dlm_lock_on_list(&res->granted, lock)) { 570 status = DLM_DENIED; 571 dlm_error(status); 572 *actions = 0; 573 } else { 574 /* unlock granted lock */ 575 status = DLM_NORMAL; 576 *actions = (DLM_UNLOCK_FREE_LOCK | 577 DLM_UNLOCK_CALL_AST | 578 DLM_UNLOCK_REMOVE_LOCK); 579 } 580 return status; 581 } 582 583 /* there seems to be no point in doing this async 584 * since (even for the remote case) there is really 585 * no work to queue up... so just do it and fire the 586 * unlockast by hand when done... */ 587 enum dlm_status dlmunlock(struct dlm_ctxt *dlm, struct dlm_lockstatus *lksb, 588 int flags, dlm_astunlockfunc_t *unlockast, void *data) 589 { 590 enum dlm_status status; 591 struct dlm_lock_resource *res; 592 struct dlm_lock *lock = NULL; 593 int call_ast, is_master; 594 595 if (!lksb) { 596 dlm_error(DLM_BADARGS); 597 return DLM_BADARGS; 598 } 599 600 if (flags & ~(LKM_CANCEL | LKM_VALBLK | LKM_INVVALBLK)) { 601 dlm_error(DLM_BADPARAM); 602 return DLM_BADPARAM; 603 } 604 605 if ((flags & (LKM_VALBLK | LKM_CANCEL)) == (LKM_VALBLK | LKM_CANCEL)) { 606 mlog(0, "VALBLK given with CANCEL: ignoring VALBLK\n"); 607 flags &= ~LKM_VALBLK; 608 } 609 610 if (!lksb->lockid || !lksb->lockid->lockres) { 611 dlm_error(DLM_BADPARAM); 612 return DLM_BADPARAM; 613 } 614 615 lock = lksb->lockid; 616 BUG_ON(!lock); 617 dlm_lock_get(lock); 618 619 res = lock->lockres; 620 BUG_ON(!res); 621 dlm_lockres_get(res); 622 retry: 623 call_ast = 0; 624 /* need to retry up here because owner may have changed */ 625 mlog(0, "lock=%p res=%p\n", lock, res); 626 627 spin_lock(&res->spinlock); 628 is_master = (res->owner == dlm->node_num); 629 if (flags & LKM_VALBLK && lock->ml.type != LKM_EXMODE) 630 flags &= ~LKM_VALBLK; 631 spin_unlock(&res->spinlock); 632 633 if (is_master) { 634 status = dlmunlock_master(dlm, res, lock, lksb, flags, 635 &call_ast); 636 mlog(0, "done calling dlmunlock_master: returned %d, " 637 "call_ast is %d\n", status, call_ast); 638 } else { 639 status = dlmunlock_remote(dlm, res, lock, lksb, flags, 640 &call_ast); 641 mlog(0, "done calling dlmunlock_remote: returned %d, " 642 "call_ast is %d\n", status, call_ast); 643 } 644 645 if (status == DLM_RECOVERING || 646 status == DLM_MIGRATING || 647 status == DLM_FORWARD || 648 status == DLM_NOLOCKMGR) { 649 650 /* We want to go away for a tiny bit to allow recovery 651 * / migration to complete on this resource. I don't 652 * know of any wait queue we could sleep on as this 653 * may be happening on another node. Perhaps the 654 * proper solution is to queue up requests on the 655 * other end? */ 656 657 /* do we want to yield(); ?? */ 658 msleep(50); 659 660 mlog(0, "retrying unlock due to pending recovery/" 661 "migration/in-progress/reconnect\n"); 662 goto retry; 663 } 664 665 if (call_ast) { 666 mlog(0, "calling unlockast(%p, %d)\n", data, status); 667 if (is_master) { 668 /* it is possible that there is one last bast 669 * pending. make sure it is flushed, then 670 * call the unlockast. 671 * not an issue if this is a mastered remotely, 672 * since this lock has been removed from the 673 * lockres queues and cannot be found. */ 674 dlm_kick_thread(dlm, NULL); 675 wait_event(dlm->ast_wq, 676 dlm_lock_basts_flushed(dlm, lock)); 677 } 678 (*unlockast)(data, status); 679 } 680 681 if (status == DLM_CANCELGRANT) 682 status = DLM_NORMAL; 683 684 if (status == DLM_NORMAL) { 685 mlog(0, "kicking the thread\n"); 686 dlm_kick_thread(dlm, res); 687 } else 688 dlm_error(status); 689 690 dlm_lockres_calc_usage(dlm, res); 691 dlm_lockres_put(res); 692 dlm_lock_put(lock); 693 694 mlog(0, "returning status=%d!\n", status); 695 return status; 696 } 697 EXPORT_SYMBOL_GPL(dlmunlock); 698 699