1 /* -*- mode: c; c-basic-offset: 8; -*- 2 * vim: noexpandtab sw=8 ts=8 sts=0: 3 * 4 * dlmthread.c 5 * 6 * standalone DLM module 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/highmem.h> 32 #include <linux/init.h> 33 #include <linux/sysctl.h> 34 #include <linux/random.h> 35 #include <linux/blkdev.h> 36 #include <linux/socket.h> 37 #include <linux/inet.h> 38 #include <linux/timer.h> 39 #include <linux/kthread.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 #include "dlmdomain.h" 50 51 #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_THREAD) 52 #include "cluster/masklog.h" 53 54 static int dlm_thread(void *data); 55 static void dlm_flush_asts(struct dlm_ctxt *dlm); 56 57 #define dlm_lock_is_remote(dlm, lock) ((lock)->ml.node != (dlm)->node_num) 58 59 /* will exit holding res->spinlock, but may drop in function */ 60 /* waits until flags are cleared on res->state */ 61 void __dlm_wait_on_lockres_flags(struct dlm_lock_resource *res, int flags) 62 { 63 DECLARE_WAITQUEUE(wait, current); 64 65 assert_spin_locked(&res->spinlock); 66 67 add_wait_queue(&res->wq, &wait); 68 repeat: 69 set_current_state(TASK_UNINTERRUPTIBLE); 70 if (res->state & flags) { 71 spin_unlock(&res->spinlock); 72 schedule(); 73 spin_lock(&res->spinlock); 74 goto repeat; 75 } 76 remove_wait_queue(&res->wq, &wait); 77 __set_current_state(TASK_RUNNING); 78 } 79 80 int __dlm_lockres_has_locks(struct dlm_lock_resource *res) 81 { 82 if (list_empty(&res->granted) && 83 list_empty(&res->converting) && 84 list_empty(&res->blocked)) 85 return 0; 86 return 1; 87 } 88 89 /* "unused": the lockres has no locks, is not on the dirty list, 90 * has no inflight locks (in the gap between mastery and acquiring 91 * the first lock), and has no bits in its refmap. 92 * truly ready to be freed. */ 93 int __dlm_lockres_unused(struct dlm_lock_resource *res) 94 { 95 int bit; 96 97 assert_spin_locked(&res->spinlock); 98 99 if (__dlm_lockres_has_locks(res)) 100 return 0; 101 102 /* Locks are in the process of being created */ 103 if (res->inflight_locks) 104 return 0; 105 106 if (!list_empty(&res->dirty) || res->state & DLM_LOCK_RES_DIRTY) 107 return 0; 108 109 if (res->state & (DLM_LOCK_RES_RECOVERING| 110 DLM_LOCK_RES_RECOVERY_WAITING)) 111 return 0; 112 113 /* Another node has this resource with this node as the master */ 114 bit = find_next_bit(res->refmap, O2NM_MAX_NODES, 0); 115 if (bit < O2NM_MAX_NODES) 116 return 0; 117 118 return 1; 119 } 120 121 122 /* Call whenever you may have added or deleted something from one of 123 * the lockres queue's. This will figure out whether it belongs on the 124 * unused list or not and does the appropriate thing. */ 125 void __dlm_lockres_calc_usage(struct dlm_ctxt *dlm, 126 struct dlm_lock_resource *res) 127 { 128 assert_spin_locked(&dlm->spinlock); 129 assert_spin_locked(&res->spinlock); 130 131 if (__dlm_lockres_unused(res)){ 132 if (list_empty(&res->purge)) { 133 mlog(0, "%s: Adding res %.*s to purge list\n", 134 dlm->name, res->lockname.len, res->lockname.name); 135 136 res->last_used = jiffies; 137 dlm_lockres_get(res); 138 list_add_tail(&res->purge, &dlm->purge_list); 139 dlm->purge_count++; 140 } 141 } else if (!list_empty(&res->purge)) { 142 mlog(0, "%s: Removing res %.*s from purge list\n", 143 dlm->name, res->lockname.len, res->lockname.name); 144 145 list_del_init(&res->purge); 146 dlm_lockres_put(res); 147 dlm->purge_count--; 148 } 149 } 150 151 void dlm_lockres_calc_usage(struct dlm_ctxt *dlm, 152 struct dlm_lock_resource *res) 153 { 154 spin_lock(&dlm->spinlock); 155 spin_lock(&res->spinlock); 156 157 __dlm_lockres_calc_usage(dlm, res); 158 159 spin_unlock(&res->spinlock); 160 spin_unlock(&dlm->spinlock); 161 } 162 163 /* 164 * Do the real purge work: 165 * unhash the lockres, and 166 * clear flag DLM_LOCK_RES_DROPPING_REF. 167 * It requires dlm and lockres spinlock to be taken. 168 */ 169 void __dlm_do_purge_lockres(struct dlm_ctxt *dlm, 170 struct dlm_lock_resource *res) 171 { 172 assert_spin_locked(&dlm->spinlock); 173 assert_spin_locked(&res->spinlock); 174 175 if (!list_empty(&res->purge)) { 176 mlog(0, "%s: Removing res %.*s from purgelist\n", 177 dlm->name, res->lockname.len, res->lockname.name); 178 list_del_init(&res->purge); 179 dlm_lockres_put(res); 180 dlm->purge_count--; 181 } 182 183 if (!__dlm_lockres_unused(res)) { 184 mlog(ML_ERROR, "%s: res %.*s in use after deref\n", 185 dlm->name, res->lockname.len, res->lockname.name); 186 __dlm_print_one_lock_resource(res); 187 BUG(); 188 } 189 190 __dlm_unhash_lockres(dlm, res); 191 192 spin_lock(&dlm->track_lock); 193 if (!list_empty(&res->tracking)) 194 list_del_init(&res->tracking); 195 else { 196 mlog(ML_ERROR, "%s: Resource %.*s not on the Tracking list\n", 197 dlm->name, res->lockname.len, res->lockname.name); 198 __dlm_print_one_lock_resource(res); 199 } 200 spin_unlock(&dlm->track_lock); 201 202 /* 203 * lockres is not in the hash now. drop the flag and wake up 204 * any processes waiting in dlm_get_lock_resource. 205 */ 206 res->state &= ~DLM_LOCK_RES_DROPPING_REF; 207 } 208 209 static void dlm_purge_lockres(struct dlm_ctxt *dlm, 210 struct dlm_lock_resource *res) 211 { 212 int master; 213 int ret = 0; 214 215 assert_spin_locked(&dlm->spinlock); 216 assert_spin_locked(&res->spinlock); 217 218 master = (res->owner == dlm->node_num); 219 220 mlog(0, "%s: Purging res %.*s, master %d\n", dlm->name, 221 res->lockname.len, res->lockname.name, master); 222 223 if (!master) { 224 if (res->state & DLM_LOCK_RES_DROPPING_REF) { 225 mlog(ML_NOTICE, "%s: res %.*s already in DLM_LOCK_RES_DROPPING_REF state\n", 226 dlm->name, res->lockname.len, res->lockname.name); 227 spin_unlock(&res->spinlock); 228 return; 229 } 230 231 res->state |= DLM_LOCK_RES_DROPPING_REF; 232 /* drop spinlock... retake below */ 233 spin_unlock(&res->spinlock); 234 spin_unlock(&dlm->spinlock); 235 236 spin_lock(&res->spinlock); 237 /* This ensures that clear refmap is sent after the set */ 238 __dlm_wait_on_lockres_flags(res, DLM_LOCK_RES_SETREF_INPROG); 239 spin_unlock(&res->spinlock); 240 241 /* clear our bit from the master's refmap, ignore errors */ 242 ret = dlm_drop_lockres_ref(dlm, res); 243 if (ret < 0) { 244 if (!dlm_is_host_down(ret)) 245 BUG(); 246 } 247 spin_lock(&dlm->spinlock); 248 spin_lock(&res->spinlock); 249 } 250 251 if (!list_empty(&res->purge)) { 252 mlog(0, "%s: Removing res %.*s from purgelist, master %d\n", 253 dlm->name, res->lockname.len, res->lockname.name, master); 254 list_del_init(&res->purge); 255 dlm_lockres_put(res); 256 dlm->purge_count--; 257 } 258 259 if (!master && ret == DLM_DEREF_RESPONSE_INPROG) { 260 mlog(0, "%s: deref %.*s in progress\n", 261 dlm->name, res->lockname.len, res->lockname.name); 262 spin_unlock(&res->spinlock); 263 return; 264 } 265 266 if (!__dlm_lockres_unused(res)) { 267 mlog(ML_ERROR, "%s: res %.*s in use after deref\n", 268 dlm->name, res->lockname.len, res->lockname.name); 269 __dlm_print_one_lock_resource(res); 270 BUG(); 271 } 272 273 __dlm_unhash_lockres(dlm, res); 274 275 spin_lock(&dlm->track_lock); 276 if (!list_empty(&res->tracking)) 277 list_del_init(&res->tracking); 278 else { 279 mlog(ML_ERROR, "Resource %.*s not on the Tracking list\n", 280 res->lockname.len, res->lockname.name); 281 __dlm_print_one_lock_resource(res); 282 } 283 spin_unlock(&dlm->track_lock); 284 285 /* lockres is not in the hash now. drop the flag and wake up 286 * any processes waiting in dlm_get_lock_resource. */ 287 if (!master) { 288 res->state &= ~DLM_LOCK_RES_DROPPING_REF; 289 spin_unlock(&res->spinlock); 290 wake_up(&res->wq); 291 } else 292 spin_unlock(&res->spinlock); 293 } 294 295 static void dlm_run_purge_list(struct dlm_ctxt *dlm, 296 int purge_now) 297 { 298 unsigned int run_max, unused; 299 unsigned long purge_jiffies; 300 struct dlm_lock_resource *lockres; 301 302 spin_lock(&dlm->spinlock); 303 run_max = dlm->purge_count; 304 305 while(run_max && !list_empty(&dlm->purge_list)) { 306 run_max--; 307 308 lockres = list_entry(dlm->purge_list.next, 309 struct dlm_lock_resource, purge); 310 311 spin_lock(&lockres->spinlock); 312 313 purge_jiffies = lockres->last_used + 314 msecs_to_jiffies(DLM_PURGE_INTERVAL_MS); 315 316 /* Make sure that we want to be processing this guy at 317 * this time. */ 318 if (!purge_now && time_after(purge_jiffies, jiffies)) { 319 /* Since resources are added to the purge list 320 * in tail order, we can stop at the first 321 * unpurgable resource -- anyone added after 322 * him will have a greater last_used value */ 323 spin_unlock(&lockres->spinlock); 324 break; 325 } 326 327 /* Status of the lockres *might* change so double 328 * check. If the lockres is unused, holding the dlm 329 * spinlock will prevent people from getting and more 330 * refs on it. */ 331 unused = __dlm_lockres_unused(lockres); 332 if (!unused || 333 (lockres->state & DLM_LOCK_RES_MIGRATING) || 334 (lockres->inflight_assert_workers != 0)) { 335 mlog(0, "%s: res %.*s is in use or being remastered, " 336 "used %d, state %d, assert master workers %u\n", 337 dlm->name, lockres->lockname.len, 338 lockres->lockname.name, 339 !unused, lockres->state, 340 lockres->inflight_assert_workers); 341 list_move_tail(&lockres->purge, &dlm->purge_list); 342 spin_unlock(&lockres->spinlock); 343 continue; 344 } 345 346 dlm_lockres_get(lockres); 347 348 dlm_purge_lockres(dlm, lockres); 349 350 dlm_lockres_put(lockres); 351 352 /* Avoid adding any scheduling latencies */ 353 cond_resched_lock(&dlm->spinlock); 354 } 355 356 spin_unlock(&dlm->spinlock); 357 } 358 359 static void dlm_shuffle_lists(struct dlm_ctxt *dlm, 360 struct dlm_lock_resource *res) 361 { 362 struct dlm_lock *lock, *target; 363 int can_grant = 1; 364 365 /* 366 * Because this function is called with the lockres 367 * spinlock, and because we know that it is not migrating/ 368 * recovering/in-progress, it is fine to reserve asts and 369 * basts right before queueing them all throughout 370 */ 371 assert_spin_locked(&dlm->ast_lock); 372 assert_spin_locked(&res->spinlock); 373 BUG_ON((res->state & (DLM_LOCK_RES_MIGRATING| 374 DLM_LOCK_RES_RECOVERING| 375 DLM_LOCK_RES_IN_PROGRESS))); 376 377 converting: 378 if (list_empty(&res->converting)) 379 goto blocked; 380 mlog(0, "%s: res %.*s has locks on the convert queue\n", dlm->name, 381 res->lockname.len, res->lockname.name); 382 383 target = list_entry(res->converting.next, struct dlm_lock, list); 384 if (target->ml.convert_type == LKM_IVMODE) { 385 mlog(ML_ERROR, "%s: res %.*s converting lock to invalid mode\n", 386 dlm->name, res->lockname.len, res->lockname.name); 387 BUG(); 388 } 389 list_for_each_entry(lock, &res->granted, list) { 390 if (lock==target) 391 continue; 392 if (!dlm_lock_compatible(lock->ml.type, 393 target->ml.convert_type)) { 394 can_grant = 0; 395 /* queue the BAST if not already */ 396 if (lock->ml.highest_blocked == LKM_IVMODE) { 397 __dlm_lockres_reserve_ast(res); 398 __dlm_queue_bast(dlm, lock); 399 } 400 /* update the highest_blocked if needed */ 401 if (lock->ml.highest_blocked < target->ml.convert_type) 402 lock->ml.highest_blocked = 403 target->ml.convert_type; 404 } 405 } 406 407 list_for_each_entry(lock, &res->converting, list) { 408 if (lock==target) 409 continue; 410 if (!dlm_lock_compatible(lock->ml.type, 411 target->ml.convert_type)) { 412 can_grant = 0; 413 if (lock->ml.highest_blocked == LKM_IVMODE) { 414 __dlm_lockres_reserve_ast(res); 415 __dlm_queue_bast(dlm, lock); 416 } 417 if (lock->ml.highest_blocked < target->ml.convert_type) 418 lock->ml.highest_blocked = 419 target->ml.convert_type; 420 } 421 } 422 423 /* we can convert the lock */ 424 if (can_grant) { 425 spin_lock(&target->spinlock); 426 BUG_ON(target->ml.highest_blocked != LKM_IVMODE); 427 428 mlog(0, "%s: res %.*s, AST for Converting lock %u:%llu, type " 429 "%d => %d, node %u\n", dlm->name, res->lockname.len, 430 res->lockname.name, 431 dlm_get_lock_cookie_node(be64_to_cpu(target->ml.cookie)), 432 dlm_get_lock_cookie_seq(be64_to_cpu(target->ml.cookie)), 433 target->ml.type, 434 target->ml.convert_type, target->ml.node); 435 436 target->ml.type = target->ml.convert_type; 437 target->ml.convert_type = LKM_IVMODE; 438 list_move_tail(&target->list, &res->granted); 439 440 BUG_ON(!target->lksb); 441 target->lksb->status = DLM_NORMAL; 442 443 spin_unlock(&target->spinlock); 444 445 __dlm_lockres_reserve_ast(res); 446 __dlm_queue_ast(dlm, target); 447 /* go back and check for more */ 448 goto converting; 449 } 450 451 blocked: 452 if (list_empty(&res->blocked)) 453 goto leave; 454 target = list_entry(res->blocked.next, struct dlm_lock, list); 455 456 list_for_each_entry(lock, &res->granted, list) { 457 if (lock==target) 458 continue; 459 if (!dlm_lock_compatible(lock->ml.type, target->ml.type)) { 460 can_grant = 0; 461 if (lock->ml.highest_blocked == LKM_IVMODE) { 462 __dlm_lockres_reserve_ast(res); 463 __dlm_queue_bast(dlm, lock); 464 } 465 if (lock->ml.highest_blocked < target->ml.type) 466 lock->ml.highest_blocked = target->ml.type; 467 } 468 } 469 470 list_for_each_entry(lock, &res->converting, list) { 471 if (lock==target) 472 continue; 473 if (!dlm_lock_compatible(lock->ml.type, target->ml.type)) { 474 can_grant = 0; 475 if (lock->ml.highest_blocked == LKM_IVMODE) { 476 __dlm_lockres_reserve_ast(res); 477 __dlm_queue_bast(dlm, lock); 478 } 479 if (lock->ml.highest_blocked < target->ml.type) 480 lock->ml.highest_blocked = target->ml.type; 481 } 482 } 483 484 /* we can grant the blocked lock (only 485 * possible if converting list empty) */ 486 if (can_grant) { 487 spin_lock(&target->spinlock); 488 BUG_ON(target->ml.highest_blocked != LKM_IVMODE); 489 490 mlog(0, "%s: res %.*s, AST for Blocked lock %u:%llu, type %d, " 491 "node %u\n", dlm->name, res->lockname.len, 492 res->lockname.name, 493 dlm_get_lock_cookie_node(be64_to_cpu(target->ml.cookie)), 494 dlm_get_lock_cookie_seq(be64_to_cpu(target->ml.cookie)), 495 target->ml.type, target->ml.node); 496 497 /* target->ml.type is already correct */ 498 list_move_tail(&target->list, &res->granted); 499 500 BUG_ON(!target->lksb); 501 target->lksb->status = DLM_NORMAL; 502 503 spin_unlock(&target->spinlock); 504 505 __dlm_lockres_reserve_ast(res); 506 __dlm_queue_ast(dlm, target); 507 /* go back and check for more */ 508 goto converting; 509 } 510 511 leave: 512 return; 513 } 514 515 /* must have NO locks when calling this with res !=NULL * */ 516 void dlm_kick_thread(struct dlm_ctxt *dlm, struct dlm_lock_resource *res) 517 { 518 if (res) { 519 spin_lock(&dlm->spinlock); 520 spin_lock(&res->spinlock); 521 __dlm_dirty_lockres(dlm, res); 522 spin_unlock(&res->spinlock); 523 spin_unlock(&dlm->spinlock); 524 } 525 wake_up(&dlm->dlm_thread_wq); 526 } 527 528 void __dlm_dirty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res) 529 { 530 assert_spin_locked(&dlm->spinlock); 531 assert_spin_locked(&res->spinlock); 532 533 /* don't shuffle secondary queues */ 534 if ((res->owner == dlm->node_num)) { 535 if (res->state & (DLM_LOCK_RES_MIGRATING | 536 DLM_LOCK_RES_BLOCK_DIRTY)) 537 return; 538 539 if (list_empty(&res->dirty)) { 540 /* ref for dirty_list */ 541 dlm_lockres_get(res); 542 list_add_tail(&res->dirty, &dlm->dirty_list); 543 res->state |= DLM_LOCK_RES_DIRTY; 544 } 545 } 546 547 mlog(0, "%s: res %.*s\n", dlm->name, res->lockname.len, 548 res->lockname.name); 549 } 550 551 552 /* Launch the NM thread for the mounted volume */ 553 int dlm_launch_thread(struct dlm_ctxt *dlm) 554 { 555 mlog(0, "Starting dlm_thread...\n"); 556 557 dlm->dlm_thread_task = kthread_run(dlm_thread, dlm, "dlm-%s", 558 dlm->name); 559 if (IS_ERR(dlm->dlm_thread_task)) { 560 mlog_errno(PTR_ERR(dlm->dlm_thread_task)); 561 dlm->dlm_thread_task = NULL; 562 return -EINVAL; 563 } 564 565 return 0; 566 } 567 568 void dlm_complete_thread(struct dlm_ctxt *dlm) 569 { 570 if (dlm->dlm_thread_task) { 571 mlog(ML_KTHREAD, "Waiting for dlm thread to exit\n"); 572 kthread_stop(dlm->dlm_thread_task); 573 dlm->dlm_thread_task = NULL; 574 } 575 } 576 577 static int dlm_dirty_list_empty(struct dlm_ctxt *dlm) 578 { 579 int empty; 580 581 spin_lock(&dlm->spinlock); 582 empty = list_empty(&dlm->dirty_list); 583 spin_unlock(&dlm->spinlock); 584 585 return empty; 586 } 587 588 static void dlm_flush_asts(struct dlm_ctxt *dlm) 589 { 590 int ret; 591 struct dlm_lock *lock; 592 struct dlm_lock_resource *res; 593 u8 hi; 594 595 spin_lock(&dlm->ast_lock); 596 while (!list_empty(&dlm->pending_asts)) { 597 lock = list_entry(dlm->pending_asts.next, 598 struct dlm_lock, ast_list); 599 /* get an extra ref on lock */ 600 dlm_lock_get(lock); 601 res = lock->lockres; 602 mlog(0, "%s: res %.*s, Flush AST for lock %u:%llu, type %d, " 603 "node %u\n", dlm->name, res->lockname.len, 604 res->lockname.name, 605 dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)), 606 dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)), 607 lock->ml.type, lock->ml.node); 608 609 BUG_ON(!lock->ast_pending); 610 611 /* remove from list (including ref) */ 612 list_del_init(&lock->ast_list); 613 dlm_lock_put(lock); 614 spin_unlock(&dlm->ast_lock); 615 616 if (lock->ml.node != dlm->node_num) { 617 ret = dlm_do_remote_ast(dlm, res, lock); 618 if (ret < 0) 619 mlog_errno(ret); 620 } else 621 dlm_do_local_ast(dlm, res, lock); 622 623 spin_lock(&dlm->ast_lock); 624 625 /* possible that another ast was queued while 626 * we were delivering the last one */ 627 if (!list_empty(&lock->ast_list)) { 628 mlog(0, "%s: res %.*s, AST queued while flushing last " 629 "one\n", dlm->name, res->lockname.len, 630 res->lockname.name); 631 } else 632 lock->ast_pending = 0; 633 634 /* drop the extra ref. 635 * this may drop it completely. */ 636 dlm_lock_put(lock); 637 dlm_lockres_release_ast(dlm, res); 638 } 639 640 while (!list_empty(&dlm->pending_basts)) { 641 lock = list_entry(dlm->pending_basts.next, 642 struct dlm_lock, bast_list); 643 /* get an extra ref on lock */ 644 dlm_lock_get(lock); 645 res = lock->lockres; 646 647 BUG_ON(!lock->bast_pending); 648 649 /* get the highest blocked lock, and reset */ 650 spin_lock(&lock->spinlock); 651 BUG_ON(lock->ml.highest_blocked <= LKM_IVMODE); 652 hi = lock->ml.highest_blocked; 653 lock->ml.highest_blocked = LKM_IVMODE; 654 spin_unlock(&lock->spinlock); 655 656 /* remove from list (including ref) */ 657 list_del_init(&lock->bast_list); 658 dlm_lock_put(lock); 659 spin_unlock(&dlm->ast_lock); 660 661 mlog(0, "%s: res %.*s, Flush BAST for lock %u:%llu, " 662 "blocked %d, node %u\n", 663 dlm->name, res->lockname.len, res->lockname.name, 664 dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)), 665 dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)), 666 hi, lock->ml.node); 667 668 if (lock->ml.node != dlm->node_num) { 669 ret = dlm_send_proxy_bast(dlm, res, lock, hi); 670 if (ret < 0) 671 mlog_errno(ret); 672 } else 673 dlm_do_local_bast(dlm, res, lock, hi); 674 675 spin_lock(&dlm->ast_lock); 676 677 /* possible that another bast was queued while 678 * we were delivering the last one */ 679 if (!list_empty(&lock->bast_list)) { 680 mlog(0, "%s: res %.*s, BAST queued while flushing last " 681 "one\n", dlm->name, res->lockname.len, 682 res->lockname.name); 683 } else 684 lock->bast_pending = 0; 685 686 /* drop the extra ref. 687 * this may drop it completely. */ 688 dlm_lock_put(lock); 689 dlm_lockres_release_ast(dlm, res); 690 } 691 wake_up(&dlm->ast_wq); 692 spin_unlock(&dlm->ast_lock); 693 } 694 695 696 #define DLM_THREAD_TIMEOUT_MS (4 * 1000) 697 #define DLM_THREAD_MAX_DIRTY 100 698 #define DLM_THREAD_MAX_ASTS 10 699 700 static int dlm_thread(void *data) 701 { 702 struct dlm_lock_resource *res; 703 struct dlm_ctxt *dlm = data; 704 unsigned long timeout = msecs_to_jiffies(DLM_THREAD_TIMEOUT_MS); 705 706 mlog(0, "dlm thread running for %s...\n", dlm->name); 707 708 while (!kthread_should_stop()) { 709 int n = DLM_THREAD_MAX_DIRTY; 710 711 /* dlm_shutting_down is very point-in-time, but that 712 * doesn't matter as we'll just loop back around if we 713 * get false on the leading edge of a state 714 * transition. */ 715 dlm_run_purge_list(dlm, dlm_shutting_down(dlm)); 716 717 /* We really don't want to hold dlm->spinlock while 718 * calling dlm_shuffle_lists on each lockres that 719 * needs to have its queues adjusted and AST/BASTs 720 * run. So let's pull each entry off the dirty_list 721 * and drop dlm->spinlock ASAP. Once off the list, 722 * res->spinlock needs to be taken again to protect 723 * the queues while calling dlm_shuffle_lists. */ 724 spin_lock(&dlm->spinlock); 725 while (!list_empty(&dlm->dirty_list)) { 726 int delay = 0; 727 res = list_entry(dlm->dirty_list.next, 728 struct dlm_lock_resource, dirty); 729 730 /* peel a lockres off, remove it from the list, 731 * unset the dirty flag and drop the dlm lock */ 732 BUG_ON(!res); 733 dlm_lockres_get(res); 734 735 spin_lock(&res->spinlock); 736 /* We clear the DLM_LOCK_RES_DIRTY state once we shuffle lists below */ 737 list_del_init(&res->dirty); 738 spin_unlock(&res->spinlock); 739 spin_unlock(&dlm->spinlock); 740 /* Drop dirty_list ref */ 741 dlm_lockres_put(res); 742 743 /* lockres can be re-dirtied/re-added to the 744 * dirty_list in this gap, but that is ok */ 745 746 spin_lock(&dlm->ast_lock); 747 spin_lock(&res->spinlock); 748 if (res->owner != dlm->node_num) { 749 __dlm_print_one_lock_resource(res); 750 mlog(ML_ERROR, "%s: inprog %d, mig %d, reco %d," 751 " dirty %d\n", dlm->name, 752 !!(res->state & DLM_LOCK_RES_IN_PROGRESS), 753 !!(res->state & DLM_LOCK_RES_MIGRATING), 754 !!(res->state & DLM_LOCK_RES_RECOVERING), 755 !!(res->state & DLM_LOCK_RES_DIRTY)); 756 } 757 BUG_ON(res->owner != dlm->node_num); 758 759 /* it is now ok to move lockreses in these states 760 * to the dirty list, assuming that they will only be 761 * dirty for a short while. */ 762 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING); 763 if (res->state & (DLM_LOCK_RES_IN_PROGRESS | 764 DLM_LOCK_RES_RECOVERING | 765 DLM_LOCK_RES_RECOVERY_WAITING)) { 766 /* move it to the tail and keep going */ 767 res->state &= ~DLM_LOCK_RES_DIRTY; 768 spin_unlock(&res->spinlock); 769 spin_unlock(&dlm->ast_lock); 770 mlog(0, "%s: res %.*s, inprogress, delay list " 771 "shuffle, state %d\n", dlm->name, 772 res->lockname.len, res->lockname.name, 773 res->state); 774 delay = 1; 775 goto in_progress; 776 } 777 778 /* at this point the lockres is not migrating/ 779 * recovering/in-progress. we have the lockres 780 * spinlock and do NOT have the dlm lock. 781 * safe to reserve/queue asts and run the lists. */ 782 783 /* called while holding lockres lock */ 784 dlm_shuffle_lists(dlm, res); 785 res->state &= ~DLM_LOCK_RES_DIRTY; 786 spin_unlock(&res->spinlock); 787 spin_unlock(&dlm->ast_lock); 788 789 dlm_lockres_calc_usage(dlm, res); 790 791 in_progress: 792 793 spin_lock(&dlm->spinlock); 794 /* if the lock was in-progress, stick 795 * it on the back of the list */ 796 if (delay) { 797 spin_lock(&res->spinlock); 798 __dlm_dirty_lockres(dlm, res); 799 spin_unlock(&res->spinlock); 800 } 801 dlm_lockres_put(res); 802 803 /* unlikely, but we may need to give time to 804 * other tasks */ 805 if (!--n) { 806 mlog(0, "%s: Throttling dlm thread\n", 807 dlm->name); 808 break; 809 } 810 } 811 812 spin_unlock(&dlm->spinlock); 813 dlm_flush_asts(dlm); 814 815 /* yield and continue right away if there is more work to do */ 816 if (!n) { 817 cond_resched(); 818 continue; 819 } 820 821 wait_event_interruptible_timeout(dlm->dlm_thread_wq, 822 !dlm_dirty_list_empty(dlm) || 823 kthread_should_stop(), 824 timeout); 825 } 826 827 mlog(0, "quitting DLM thread\n"); 828 return 0; 829 } 830