dlmglue.c revision 08280f11de91beac2f5234ce5fc2ed246dfe6a86
1/* -*- mode: c; c-basic-offset: 8; -*- 2 * vim: noexpandtab sw=8 ts=8 sts=0: 3 * 4 * dlmglue.c 5 * 6 * Code which implements an OCFS2 specific interface to our DLM. 7 * 8 * Copyright (C) 2003, 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#include <linux/types.h> 27#include <linux/slab.h> 28#include <linux/highmem.h> 29#include <linux/mm.h> 30#include <linux/smp_lock.h> 31#include <linux/crc32.h> 32#include <linux/kthread.h> 33#include <linux/pagemap.h> 34#include <linux/debugfs.h> 35#include <linux/seq_file.h> 36 37#include <cluster/heartbeat.h> 38#include <cluster/nodemanager.h> 39#include <cluster/tcp.h> 40 41#include <dlm/dlmapi.h> 42 43#define MLOG_MASK_PREFIX ML_DLM_GLUE 44#include <cluster/masklog.h> 45 46#include "ocfs2.h" 47 48#include "alloc.h" 49#include "dcache.h" 50#include "dlmglue.h" 51#include "extent_map.h" 52#include "heartbeat.h" 53#include "inode.h" 54#include "journal.h" 55#include "slot_map.h" 56#include "super.h" 57#include "uptodate.h" 58#include "vote.h" 59 60#include "buffer_head_io.h" 61 62struct ocfs2_mask_waiter { 63 struct list_head mw_item; 64 int mw_status; 65 struct completion mw_complete; 66 unsigned long mw_mask; 67 unsigned long mw_goal; 68}; 69 70static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres); 71static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres); 72 73/* 74 * Return value from ocfs2_convert_worker_t functions. 75 * 76 * These control the precise actions of ocfs2_generic_unblock_lock() 77 * and ocfs2_process_blocked_lock() 78 * 79 */ 80enum ocfs2_unblock_action { 81 UNBLOCK_CONTINUE = 0, /* Continue downconvert */ 82 UNBLOCK_CONTINUE_POST = 1, /* Continue downconvert, fire 83 * ->post_unlock callback */ 84 UNBLOCK_STOP_POST = 2, /* Do not downconvert, fire 85 * ->post_unlock() callback. */ 86}; 87 88struct ocfs2_unblock_ctl { 89 int requeue; 90 enum ocfs2_unblock_action unblock_action; 91}; 92 93static int ocfs2_unblock_meta(struct ocfs2_lock_res *lockres, 94 struct ocfs2_unblock_ctl *ctl); 95static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres, 96 int new_level); 97static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres); 98 99static int ocfs2_unblock_data(struct ocfs2_lock_res *lockres, 100 struct ocfs2_unblock_ctl *ctl); 101static int ocfs2_unblock_inode_lock(struct ocfs2_lock_res *lockres, 102 struct ocfs2_unblock_ctl *ctl); 103static int ocfs2_unblock_dentry_lock(struct ocfs2_lock_res *lockres, 104 struct ocfs2_unblock_ctl *ctl); 105static int ocfs2_unblock_osb_lock(struct ocfs2_lock_res *lockres, 106 struct ocfs2_unblock_ctl *ctl); 107 108static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb, 109 struct ocfs2_lock_res *lockres); 110 111/* 112 * OCFS2 Lock Resource Operations 113 * 114 * These fine tune the behavior of the generic dlmglue locking infrastructure. 115 */ 116struct ocfs2_lock_res_ops { 117 /* 118 * Translate an ocfs2_lock_res * into an ocfs2_super *. Define 119 * this callback if ->l_priv is not an ocfs2_super pointer 120 */ 121 struct ocfs2_super * (*get_osb)(struct ocfs2_lock_res *); 122 int (*unblock)(struct ocfs2_lock_res *, struct ocfs2_unblock_ctl *); 123 void (*post_unlock)(struct ocfs2_super *, struct ocfs2_lock_res *); 124 125 /* 126 * Allow a lock type to add checks to determine whether it is 127 * safe to downconvert a lock. Return 0 to re-queue the 128 * downconvert at a later time, nonzero to continue. 129 * 130 * For most locks, the default checks that there are no 131 * incompatible holders are sufficient. 132 * 133 * Called with the lockres spinlock held. 134 */ 135 int (*check_downconvert)(struct ocfs2_lock_res *, int); 136 137 /* 138 * Allows a lock type to populate the lock value block. This 139 * is called on downconvert, and when we drop a lock. 140 * 141 * Locks that want to use this should set LOCK_TYPE_USES_LVB 142 * in the flags field. 143 * 144 * Called with the lockres spinlock held. 145 */ 146 void (*set_lvb)(struct ocfs2_lock_res *); 147 148 /* 149 * LOCK_TYPE_* flags which describe the specific requirements 150 * of a lock type. Descriptions of each individual flag follow. 151 */ 152 int flags; 153}; 154 155/* 156 * Some locks want to "refresh" potentially stale data when a 157 * meaningful (PRMODE or EXMODE) lock level is first obtained. If this 158 * flag is set, the OCFS2_LOCK_NEEDS_REFRESH flag will be set on the 159 * individual lockres l_flags member from the ast function. It is 160 * expected that the locking wrapper will clear the 161 * OCFS2_LOCK_NEEDS_REFRESH flag when done. 162 */ 163#define LOCK_TYPE_REQUIRES_REFRESH 0x1 164 165/* 166 * Indicate that a lock type makes use of the lock value block. The 167 * ->set_lvb lock type callback must be defined. 168 */ 169#define LOCK_TYPE_USES_LVB 0x2 170 171typedef int (ocfs2_convert_worker_t)(struct ocfs2_lock_res *, int); 172static int ocfs2_generic_unblock_lock(struct ocfs2_super *osb, 173 struct ocfs2_lock_res *lockres, 174 struct ocfs2_unblock_ctl *ctl, 175 ocfs2_convert_worker_t *worker); 176 177static struct ocfs2_lock_res_ops ocfs2_inode_rw_lops = { 178 .get_osb = ocfs2_get_inode_osb, 179 .unblock = ocfs2_unblock_inode_lock, 180 .flags = 0, 181}; 182 183static struct ocfs2_lock_res_ops ocfs2_inode_meta_lops = { 184 .get_osb = ocfs2_get_inode_osb, 185 .unblock = ocfs2_unblock_meta, 186 .check_downconvert = ocfs2_check_meta_downconvert, 187 .set_lvb = ocfs2_set_meta_lvb, 188 .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB, 189}; 190 191static struct ocfs2_lock_res_ops ocfs2_inode_data_lops = { 192 .get_osb = ocfs2_get_inode_osb, 193 .unblock = ocfs2_unblock_data, 194 .flags = 0, 195}; 196 197static struct ocfs2_lock_res_ops ocfs2_super_lops = { 198 .unblock = ocfs2_unblock_osb_lock, 199 .flags = LOCK_TYPE_REQUIRES_REFRESH, 200}; 201 202static struct ocfs2_lock_res_ops ocfs2_rename_lops = { 203 .unblock = ocfs2_unblock_osb_lock, 204 .flags = 0, 205}; 206 207static struct ocfs2_lock_res_ops ocfs2_dentry_lops = { 208 .get_osb = ocfs2_get_dentry_osb, 209 .unblock = ocfs2_unblock_dentry_lock, 210 .post_unlock = ocfs2_dentry_post_unlock, 211 .flags = 0, 212}; 213 214static inline int ocfs2_is_inode_lock(struct ocfs2_lock_res *lockres) 215{ 216 return lockres->l_type == OCFS2_LOCK_TYPE_META || 217 lockres->l_type == OCFS2_LOCK_TYPE_DATA || 218 lockres->l_type == OCFS2_LOCK_TYPE_RW; 219} 220 221static inline struct inode *ocfs2_lock_res_inode(struct ocfs2_lock_res *lockres) 222{ 223 BUG_ON(!ocfs2_is_inode_lock(lockres)); 224 225 return (struct inode *) lockres->l_priv; 226} 227 228static inline struct ocfs2_dentry_lock *ocfs2_lock_res_dl(struct ocfs2_lock_res *lockres) 229{ 230 BUG_ON(lockres->l_type != OCFS2_LOCK_TYPE_DENTRY); 231 232 return (struct ocfs2_dentry_lock *)lockres->l_priv; 233} 234 235static inline struct ocfs2_super *ocfs2_get_lockres_osb(struct ocfs2_lock_res *lockres) 236{ 237 if (lockres->l_ops->get_osb) 238 return lockres->l_ops->get_osb(lockres); 239 240 return (struct ocfs2_super *)lockres->l_priv; 241} 242 243static int ocfs2_lock_create(struct ocfs2_super *osb, 244 struct ocfs2_lock_res *lockres, 245 int level, 246 int dlm_flags); 247static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres, 248 int wanted); 249static void ocfs2_cluster_unlock(struct ocfs2_super *osb, 250 struct ocfs2_lock_res *lockres, 251 int level); 252static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres); 253static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres); 254static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres); 255static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres, int level); 256static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb, 257 struct ocfs2_lock_res *lockres); 258static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres, 259 int convert); 260#define ocfs2_log_dlm_error(_func, _stat, _lockres) do { \ 261 mlog(ML_ERROR, "Dlm error \"%s\" while calling %s on " \ 262 "resource %s: %s\n", dlm_errname(_stat), _func, \ 263 _lockres->l_name, dlm_errmsg(_stat)); \ 264} while (0) 265static void ocfs2_vote_on_unlock(struct ocfs2_super *osb, 266 struct ocfs2_lock_res *lockres); 267static int ocfs2_meta_lock_update(struct inode *inode, 268 struct buffer_head **bh); 269static void ocfs2_drop_osb_locks(struct ocfs2_super *osb); 270static inline int ocfs2_highest_compat_lock_level(int level); 271 272static void ocfs2_build_lock_name(enum ocfs2_lock_type type, 273 u64 blkno, 274 u32 generation, 275 char *name) 276{ 277 int len; 278 279 mlog_entry_void(); 280 281 BUG_ON(type >= OCFS2_NUM_LOCK_TYPES); 282 283 len = snprintf(name, OCFS2_LOCK_ID_MAX_LEN, "%c%s%016llx%08x", 284 ocfs2_lock_type_char(type), OCFS2_LOCK_ID_PAD, 285 (long long)blkno, generation); 286 287 BUG_ON(len != (OCFS2_LOCK_ID_MAX_LEN - 1)); 288 289 mlog(0, "built lock resource with name: %s\n", name); 290 291 mlog_exit_void(); 292} 293 294static DEFINE_SPINLOCK(ocfs2_dlm_tracking_lock); 295 296static void ocfs2_add_lockres_tracking(struct ocfs2_lock_res *res, 297 struct ocfs2_dlm_debug *dlm_debug) 298{ 299 mlog(0, "Add tracking for lockres %s\n", res->l_name); 300 301 spin_lock(&ocfs2_dlm_tracking_lock); 302 list_add(&res->l_debug_list, &dlm_debug->d_lockres_tracking); 303 spin_unlock(&ocfs2_dlm_tracking_lock); 304} 305 306static void ocfs2_remove_lockres_tracking(struct ocfs2_lock_res *res) 307{ 308 spin_lock(&ocfs2_dlm_tracking_lock); 309 if (!list_empty(&res->l_debug_list)) 310 list_del_init(&res->l_debug_list); 311 spin_unlock(&ocfs2_dlm_tracking_lock); 312} 313 314static void ocfs2_lock_res_init_common(struct ocfs2_super *osb, 315 struct ocfs2_lock_res *res, 316 enum ocfs2_lock_type type, 317 struct ocfs2_lock_res_ops *ops, 318 void *priv) 319{ 320 res->l_type = type; 321 res->l_ops = ops; 322 res->l_priv = priv; 323 324 res->l_level = LKM_IVMODE; 325 res->l_requested = LKM_IVMODE; 326 res->l_blocking = LKM_IVMODE; 327 res->l_action = OCFS2_AST_INVALID; 328 res->l_unlock_action = OCFS2_UNLOCK_INVALID; 329 330 res->l_flags = OCFS2_LOCK_INITIALIZED; 331 332 ocfs2_add_lockres_tracking(res, osb->osb_dlm_debug); 333} 334 335void ocfs2_lock_res_init_once(struct ocfs2_lock_res *res) 336{ 337 /* This also clears out the lock status block */ 338 memset(res, 0, sizeof(struct ocfs2_lock_res)); 339 spin_lock_init(&res->l_lock); 340 init_waitqueue_head(&res->l_event); 341 INIT_LIST_HEAD(&res->l_blocked_list); 342 INIT_LIST_HEAD(&res->l_mask_waiters); 343} 344 345void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res, 346 enum ocfs2_lock_type type, 347 unsigned int generation, 348 struct inode *inode) 349{ 350 struct ocfs2_lock_res_ops *ops; 351 352 switch(type) { 353 case OCFS2_LOCK_TYPE_RW: 354 ops = &ocfs2_inode_rw_lops; 355 break; 356 case OCFS2_LOCK_TYPE_META: 357 ops = &ocfs2_inode_meta_lops; 358 break; 359 case OCFS2_LOCK_TYPE_DATA: 360 ops = &ocfs2_inode_data_lops; 361 break; 362 default: 363 mlog_bug_on_msg(1, "type: %d\n", type); 364 ops = NULL; /* thanks, gcc */ 365 break; 366 }; 367 368 ocfs2_build_lock_name(type, OCFS2_I(inode)->ip_blkno, 369 generation, res->l_name); 370 ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), res, type, ops, inode); 371} 372 373static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres) 374{ 375 struct inode *inode = ocfs2_lock_res_inode(lockres); 376 377 return OCFS2_SB(inode->i_sb); 378} 379 380static __u64 ocfs2_get_dentry_lock_ino(struct ocfs2_lock_res *lockres) 381{ 382 __be64 inode_blkno_be; 383 384 memcpy(&inode_blkno_be, &lockres->l_name[OCFS2_DENTRY_LOCK_INO_START], 385 sizeof(__be64)); 386 387 return be64_to_cpu(inode_blkno_be); 388} 389 390static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres) 391{ 392 struct ocfs2_dentry_lock *dl = lockres->l_priv; 393 394 return OCFS2_SB(dl->dl_inode->i_sb); 395} 396 397void ocfs2_dentry_lock_res_init(struct ocfs2_dentry_lock *dl, 398 u64 parent, struct inode *inode) 399{ 400 int len; 401 u64 inode_blkno = OCFS2_I(inode)->ip_blkno; 402 __be64 inode_blkno_be = cpu_to_be64(inode_blkno); 403 struct ocfs2_lock_res *lockres = &dl->dl_lockres; 404 405 ocfs2_lock_res_init_once(lockres); 406 407 /* 408 * Unfortunately, the standard lock naming scheme won't work 409 * here because we have two 16 byte values to use. Instead, 410 * we'll stuff the inode number as a binary value. We still 411 * want error prints to show something without garbling the 412 * display, so drop a null byte in there before the inode 413 * number. A future version of OCFS2 will likely use all 414 * binary lock names. The stringified names have been a 415 * tremendous aid in debugging, but now that the debugfs 416 * interface exists, we can mangle things there if need be. 417 * 418 * NOTE: We also drop the standard "pad" value (the total lock 419 * name size stays the same though - the last part is all 420 * zeros due to the memset in ocfs2_lock_res_init_once() 421 */ 422 len = snprintf(lockres->l_name, OCFS2_DENTRY_LOCK_INO_START, 423 "%c%016llx", 424 ocfs2_lock_type_char(OCFS2_LOCK_TYPE_DENTRY), 425 (long long)parent); 426 427 BUG_ON(len != (OCFS2_DENTRY_LOCK_INO_START - 1)); 428 429 memcpy(&lockres->l_name[OCFS2_DENTRY_LOCK_INO_START], &inode_blkno_be, 430 sizeof(__be64)); 431 432 ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), lockres, 433 OCFS2_LOCK_TYPE_DENTRY, &ocfs2_dentry_lops, 434 dl); 435} 436 437static void ocfs2_super_lock_res_init(struct ocfs2_lock_res *res, 438 struct ocfs2_super *osb) 439{ 440 /* Superblock lockres doesn't come from a slab so we call init 441 * once on it manually. */ 442 ocfs2_lock_res_init_once(res); 443 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_SUPER, OCFS2_SUPER_BLOCK_BLKNO, 444 0, res->l_name); 445 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_SUPER, 446 &ocfs2_super_lops, osb); 447} 448 449static void ocfs2_rename_lock_res_init(struct ocfs2_lock_res *res, 450 struct ocfs2_super *osb) 451{ 452 /* Rename lockres doesn't come from a slab so we call init 453 * once on it manually. */ 454 ocfs2_lock_res_init_once(res); 455 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_RENAME, 0, 0, res->l_name); 456 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_RENAME, 457 &ocfs2_rename_lops, osb); 458} 459 460void ocfs2_lock_res_free(struct ocfs2_lock_res *res) 461{ 462 mlog_entry_void(); 463 464 if (!(res->l_flags & OCFS2_LOCK_INITIALIZED)) 465 return; 466 467 ocfs2_remove_lockres_tracking(res); 468 469 mlog_bug_on_msg(!list_empty(&res->l_blocked_list), 470 "Lockres %s is on the blocked list\n", 471 res->l_name); 472 mlog_bug_on_msg(!list_empty(&res->l_mask_waiters), 473 "Lockres %s has mask waiters pending\n", 474 res->l_name); 475 mlog_bug_on_msg(spin_is_locked(&res->l_lock), 476 "Lockres %s is locked\n", 477 res->l_name); 478 mlog_bug_on_msg(res->l_ro_holders, 479 "Lockres %s has %u ro holders\n", 480 res->l_name, res->l_ro_holders); 481 mlog_bug_on_msg(res->l_ex_holders, 482 "Lockres %s has %u ex holders\n", 483 res->l_name, res->l_ex_holders); 484 485 /* Need to clear out the lock status block for the dlm */ 486 memset(&res->l_lksb, 0, sizeof(res->l_lksb)); 487 488 res->l_flags = 0UL; 489 mlog_exit_void(); 490} 491 492static inline void ocfs2_inc_holders(struct ocfs2_lock_res *lockres, 493 int level) 494{ 495 mlog_entry_void(); 496 497 BUG_ON(!lockres); 498 499 switch(level) { 500 case LKM_EXMODE: 501 lockres->l_ex_holders++; 502 break; 503 case LKM_PRMODE: 504 lockres->l_ro_holders++; 505 break; 506 default: 507 BUG(); 508 } 509 510 mlog_exit_void(); 511} 512 513static inline void ocfs2_dec_holders(struct ocfs2_lock_res *lockres, 514 int level) 515{ 516 mlog_entry_void(); 517 518 BUG_ON(!lockres); 519 520 switch(level) { 521 case LKM_EXMODE: 522 BUG_ON(!lockres->l_ex_holders); 523 lockres->l_ex_holders--; 524 break; 525 case LKM_PRMODE: 526 BUG_ON(!lockres->l_ro_holders); 527 lockres->l_ro_holders--; 528 break; 529 default: 530 BUG(); 531 } 532 mlog_exit_void(); 533} 534 535/* WARNING: This function lives in a world where the only three lock 536 * levels are EX, PR, and NL. It *will* have to be adjusted when more 537 * lock types are added. */ 538static inline int ocfs2_highest_compat_lock_level(int level) 539{ 540 int new_level = LKM_EXMODE; 541 542 if (level == LKM_EXMODE) 543 new_level = LKM_NLMODE; 544 else if (level == LKM_PRMODE) 545 new_level = LKM_PRMODE; 546 return new_level; 547} 548 549static void lockres_set_flags(struct ocfs2_lock_res *lockres, 550 unsigned long newflags) 551{ 552 struct list_head *pos, *tmp; 553 struct ocfs2_mask_waiter *mw; 554 555 assert_spin_locked(&lockres->l_lock); 556 557 lockres->l_flags = newflags; 558 559 list_for_each_safe(pos, tmp, &lockres->l_mask_waiters) { 560 mw = list_entry(pos, struct ocfs2_mask_waiter, mw_item); 561 if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal) 562 continue; 563 564 list_del_init(&mw->mw_item); 565 mw->mw_status = 0; 566 complete(&mw->mw_complete); 567 } 568} 569static void lockres_or_flags(struct ocfs2_lock_res *lockres, unsigned long or) 570{ 571 lockres_set_flags(lockres, lockres->l_flags | or); 572} 573static void lockres_clear_flags(struct ocfs2_lock_res *lockres, 574 unsigned long clear) 575{ 576 lockres_set_flags(lockres, lockres->l_flags & ~clear); 577} 578 579static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres) 580{ 581 mlog_entry_void(); 582 583 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY)); 584 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED)); 585 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED)); 586 BUG_ON(lockres->l_blocking <= LKM_NLMODE); 587 588 lockres->l_level = lockres->l_requested; 589 if (lockres->l_level <= 590 ocfs2_highest_compat_lock_level(lockres->l_blocking)) { 591 lockres->l_blocking = LKM_NLMODE; 592 lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED); 593 } 594 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); 595 596 mlog_exit_void(); 597} 598 599static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres) 600{ 601 mlog_entry_void(); 602 603 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY)); 604 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED)); 605 606 /* Convert from RO to EX doesn't really need anything as our 607 * information is already up to data. Convert from NL to 608 * *anything* however should mark ourselves as needing an 609 * update */ 610 if (lockres->l_level == LKM_NLMODE && 611 lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH) 612 lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH); 613 614 lockres->l_level = lockres->l_requested; 615 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); 616 617 mlog_exit_void(); 618} 619 620static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres) 621{ 622 mlog_entry_void(); 623 624 BUG_ON((!lockres->l_flags & OCFS2_LOCK_BUSY)); 625 BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED); 626 627 if (lockres->l_requested > LKM_NLMODE && 628 !(lockres->l_flags & OCFS2_LOCK_LOCAL) && 629 lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH) 630 lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH); 631 632 lockres->l_level = lockres->l_requested; 633 lockres_or_flags(lockres, OCFS2_LOCK_ATTACHED); 634 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); 635 636 mlog_exit_void(); 637} 638 639static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres, 640 int level) 641{ 642 int needs_downconvert = 0; 643 mlog_entry_void(); 644 645 assert_spin_locked(&lockres->l_lock); 646 647 lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED); 648 649 if (level > lockres->l_blocking) { 650 /* only schedule a downconvert if we haven't already scheduled 651 * one that goes low enough to satisfy the level we're 652 * blocking. this also catches the case where we get 653 * duplicate BASTs */ 654 if (ocfs2_highest_compat_lock_level(level) < 655 ocfs2_highest_compat_lock_level(lockres->l_blocking)) 656 needs_downconvert = 1; 657 658 lockres->l_blocking = level; 659 } 660 661 mlog_exit(needs_downconvert); 662 return needs_downconvert; 663} 664 665static void ocfs2_blocking_ast(void *opaque, int level) 666{ 667 struct ocfs2_lock_res *lockres = opaque; 668 struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres); 669 int needs_downconvert; 670 unsigned long flags; 671 672 BUG_ON(level <= LKM_NLMODE); 673 674 mlog(0, "BAST fired for lockres %s, blocking %d, level %d type %s\n", 675 lockres->l_name, level, lockres->l_level, 676 ocfs2_lock_type_string(lockres->l_type)); 677 678 spin_lock_irqsave(&lockres->l_lock, flags); 679 needs_downconvert = ocfs2_generic_handle_bast(lockres, level); 680 if (needs_downconvert) 681 ocfs2_schedule_blocked_lock(osb, lockres); 682 spin_unlock_irqrestore(&lockres->l_lock, flags); 683 684 wake_up(&lockres->l_event); 685 686 ocfs2_kick_vote_thread(osb); 687} 688 689static void ocfs2_locking_ast(void *opaque) 690{ 691 struct ocfs2_lock_res *lockres = opaque; 692 struct dlm_lockstatus *lksb = &lockres->l_lksb; 693 unsigned long flags; 694 695 spin_lock_irqsave(&lockres->l_lock, flags); 696 697 if (lksb->status != DLM_NORMAL) { 698 mlog(ML_ERROR, "lockres %s: lksb status value of %u!\n", 699 lockres->l_name, lksb->status); 700 spin_unlock_irqrestore(&lockres->l_lock, flags); 701 return; 702 } 703 704 switch(lockres->l_action) { 705 case OCFS2_AST_ATTACH: 706 ocfs2_generic_handle_attach_action(lockres); 707 lockres_clear_flags(lockres, OCFS2_LOCK_LOCAL); 708 break; 709 case OCFS2_AST_CONVERT: 710 ocfs2_generic_handle_convert_action(lockres); 711 break; 712 case OCFS2_AST_DOWNCONVERT: 713 ocfs2_generic_handle_downconvert_action(lockres); 714 break; 715 default: 716 mlog(ML_ERROR, "lockres %s: ast fired with invalid action: %u " 717 "lockres flags = 0x%lx, unlock action: %u\n", 718 lockres->l_name, lockres->l_action, lockres->l_flags, 719 lockres->l_unlock_action); 720 BUG(); 721 } 722 723 /* set it to something invalid so if we get called again we 724 * can catch it. */ 725 lockres->l_action = OCFS2_AST_INVALID; 726 727 wake_up(&lockres->l_event); 728 spin_unlock_irqrestore(&lockres->l_lock, flags); 729} 730 731static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres, 732 int convert) 733{ 734 unsigned long flags; 735 736 mlog_entry_void(); 737 spin_lock_irqsave(&lockres->l_lock, flags); 738 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); 739 if (convert) 740 lockres->l_action = OCFS2_AST_INVALID; 741 else 742 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID; 743 spin_unlock_irqrestore(&lockres->l_lock, flags); 744 745 wake_up(&lockres->l_event); 746 mlog_exit_void(); 747} 748 749/* Note: If we detect another process working on the lock (i.e., 750 * OCFS2_LOCK_BUSY), we'll bail out returning 0. It's up to the caller 751 * to do the right thing in that case. 752 */ 753static int ocfs2_lock_create(struct ocfs2_super *osb, 754 struct ocfs2_lock_res *lockres, 755 int level, 756 int dlm_flags) 757{ 758 int ret = 0; 759 enum dlm_status status; 760 unsigned long flags; 761 762 mlog_entry_void(); 763 764 mlog(0, "lock %s, level = %d, flags = %d\n", lockres->l_name, level, 765 dlm_flags); 766 767 spin_lock_irqsave(&lockres->l_lock, flags); 768 if ((lockres->l_flags & OCFS2_LOCK_ATTACHED) || 769 (lockres->l_flags & OCFS2_LOCK_BUSY)) { 770 spin_unlock_irqrestore(&lockres->l_lock, flags); 771 goto bail; 772 } 773 774 lockres->l_action = OCFS2_AST_ATTACH; 775 lockres->l_requested = level; 776 lockres_or_flags(lockres, OCFS2_LOCK_BUSY); 777 spin_unlock_irqrestore(&lockres->l_lock, flags); 778 779 status = dlmlock(osb->dlm, 780 level, 781 &lockres->l_lksb, 782 dlm_flags, 783 lockres->l_name, 784 OCFS2_LOCK_ID_MAX_LEN - 1, 785 ocfs2_locking_ast, 786 lockres, 787 ocfs2_blocking_ast); 788 if (status != DLM_NORMAL) { 789 ocfs2_log_dlm_error("dlmlock", status, lockres); 790 ret = -EINVAL; 791 ocfs2_recover_from_dlm_error(lockres, 1); 792 } 793 794 mlog(0, "lock %s, successfull return from dlmlock\n", lockres->l_name); 795 796bail: 797 mlog_exit(ret); 798 return ret; 799} 800 801static inline int ocfs2_check_wait_flag(struct ocfs2_lock_res *lockres, 802 int flag) 803{ 804 unsigned long flags; 805 int ret; 806 807 spin_lock_irqsave(&lockres->l_lock, flags); 808 ret = lockres->l_flags & flag; 809 spin_unlock_irqrestore(&lockres->l_lock, flags); 810 811 return ret; 812} 813 814static inline void ocfs2_wait_on_busy_lock(struct ocfs2_lock_res *lockres) 815 816{ 817 wait_event(lockres->l_event, 818 !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_BUSY)); 819} 820 821static inline void ocfs2_wait_on_refreshing_lock(struct ocfs2_lock_res *lockres) 822 823{ 824 wait_event(lockres->l_event, 825 !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_REFRESHING)); 826} 827 828/* predict what lock level we'll be dropping down to on behalf 829 * of another node, and return true if the currently wanted 830 * level will be compatible with it. */ 831static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres, 832 int wanted) 833{ 834 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED)); 835 836 return wanted <= ocfs2_highest_compat_lock_level(lockres->l_blocking); 837} 838 839static void ocfs2_init_mask_waiter(struct ocfs2_mask_waiter *mw) 840{ 841 INIT_LIST_HEAD(&mw->mw_item); 842 init_completion(&mw->mw_complete); 843} 844 845static int ocfs2_wait_for_mask(struct ocfs2_mask_waiter *mw) 846{ 847 wait_for_completion(&mw->mw_complete); 848 /* Re-arm the completion in case we want to wait on it again */ 849 INIT_COMPLETION(mw->mw_complete); 850 return mw->mw_status; 851} 852 853static void lockres_add_mask_waiter(struct ocfs2_lock_res *lockres, 854 struct ocfs2_mask_waiter *mw, 855 unsigned long mask, 856 unsigned long goal) 857{ 858 BUG_ON(!list_empty(&mw->mw_item)); 859 860 assert_spin_locked(&lockres->l_lock); 861 862 list_add_tail(&mw->mw_item, &lockres->l_mask_waiters); 863 mw->mw_mask = mask; 864 mw->mw_goal = goal; 865} 866 867/* returns 0 if the mw that was removed was already satisfied, -EBUSY 868 * if the mask still hadn't reached its goal */ 869static int lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres, 870 struct ocfs2_mask_waiter *mw) 871{ 872 unsigned long flags; 873 int ret = 0; 874 875 spin_lock_irqsave(&lockres->l_lock, flags); 876 if (!list_empty(&mw->mw_item)) { 877 if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal) 878 ret = -EBUSY; 879 880 list_del_init(&mw->mw_item); 881 init_completion(&mw->mw_complete); 882 } 883 spin_unlock_irqrestore(&lockres->l_lock, flags); 884 885 return ret; 886 887} 888 889static int ocfs2_cluster_lock(struct ocfs2_super *osb, 890 struct ocfs2_lock_res *lockres, 891 int level, 892 int lkm_flags, 893 int arg_flags) 894{ 895 struct ocfs2_mask_waiter mw; 896 enum dlm_status status; 897 int wait, catch_signals = !(osb->s_mount_opt & OCFS2_MOUNT_NOINTR); 898 int ret = 0; /* gcc doesn't realize wait = 1 guarantees ret is set */ 899 unsigned long flags; 900 901 mlog_entry_void(); 902 903 ocfs2_init_mask_waiter(&mw); 904 905 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) 906 lkm_flags |= LKM_VALBLK; 907 908again: 909 wait = 0; 910 911 if (catch_signals && signal_pending(current)) { 912 ret = -ERESTARTSYS; 913 goto out; 914 } 915 916 spin_lock_irqsave(&lockres->l_lock, flags); 917 918 mlog_bug_on_msg(lockres->l_flags & OCFS2_LOCK_FREEING, 919 "Cluster lock called on freeing lockres %s! flags " 920 "0x%lx\n", lockres->l_name, lockres->l_flags); 921 922 /* We only compare against the currently granted level 923 * here. If the lock is blocked waiting on a downconvert, 924 * we'll get caught below. */ 925 if (lockres->l_flags & OCFS2_LOCK_BUSY && 926 level > lockres->l_level) { 927 /* is someone sitting in dlm_lock? If so, wait on 928 * them. */ 929 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0); 930 wait = 1; 931 goto unlock; 932 } 933 934 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) { 935 /* lock has not been created yet. */ 936 spin_unlock_irqrestore(&lockres->l_lock, flags); 937 938 ret = ocfs2_lock_create(osb, lockres, LKM_NLMODE, 0); 939 if (ret < 0) { 940 mlog_errno(ret); 941 goto out; 942 } 943 goto again; 944 } 945 946 if (lockres->l_flags & OCFS2_LOCK_BLOCKED && 947 !ocfs2_may_continue_on_blocked_lock(lockres, level)) { 948 /* is the lock is currently blocked on behalf of 949 * another node */ 950 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BLOCKED, 0); 951 wait = 1; 952 goto unlock; 953 } 954 955 if (level > lockres->l_level) { 956 if (lockres->l_action != OCFS2_AST_INVALID) 957 mlog(ML_ERROR, "lockres %s has action %u pending\n", 958 lockres->l_name, lockres->l_action); 959 960 lockres->l_action = OCFS2_AST_CONVERT; 961 lockres->l_requested = level; 962 lockres_or_flags(lockres, OCFS2_LOCK_BUSY); 963 spin_unlock_irqrestore(&lockres->l_lock, flags); 964 965 BUG_ON(level == LKM_IVMODE); 966 BUG_ON(level == LKM_NLMODE); 967 968 mlog(0, "lock %s, convert from %d to level = %d\n", 969 lockres->l_name, lockres->l_level, level); 970 971 /* call dlm_lock to upgrade lock now */ 972 status = dlmlock(osb->dlm, 973 level, 974 &lockres->l_lksb, 975 lkm_flags|LKM_CONVERT, 976 lockres->l_name, 977 OCFS2_LOCK_ID_MAX_LEN - 1, 978 ocfs2_locking_ast, 979 lockres, 980 ocfs2_blocking_ast); 981 if (status != DLM_NORMAL) { 982 if ((lkm_flags & LKM_NOQUEUE) && 983 (status == DLM_NOTQUEUED)) 984 ret = -EAGAIN; 985 else { 986 ocfs2_log_dlm_error("dlmlock", status, 987 lockres); 988 ret = -EINVAL; 989 } 990 ocfs2_recover_from_dlm_error(lockres, 1); 991 goto out; 992 } 993 994 mlog(0, "lock %s, successfull return from dlmlock\n", 995 lockres->l_name); 996 997 /* At this point we've gone inside the dlm and need to 998 * complete our work regardless. */ 999 catch_signals = 0; 1000 1001 /* wait for busy to clear and carry on */ 1002 goto again; 1003 } 1004 1005 /* Ok, if we get here then we're good to go. */ 1006 ocfs2_inc_holders(lockres, level); 1007 1008 ret = 0; 1009unlock: 1010 spin_unlock_irqrestore(&lockres->l_lock, flags); 1011out: 1012 /* 1013 * This is helping work around a lock inversion between the page lock 1014 * and dlm locks. One path holds the page lock while calling aops 1015 * which block acquiring dlm locks. The voting thread holds dlm 1016 * locks while acquiring page locks while down converting data locks. 1017 * This block is helping an aop path notice the inversion and back 1018 * off to unlock its page lock before trying the dlm lock again. 1019 */ 1020 if (wait && arg_flags & OCFS2_LOCK_NONBLOCK && 1021 mw.mw_mask & (OCFS2_LOCK_BUSY|OCFS2_LOCK_BLOCKED)) { 1022 wait = 0; 1023 if (lockres_remove_mask_waiter(lockres, &mw)) 1024 ret = -EAGAIN; 1025 else 1026 goto again; 1027 } 1028 if (wait) { 1029 ret = ocfs2_wait_for_mask(&mw); 1030 if (ret == 0) 1031 goto again; 1032 mlog_errno(ret); 1033 } 1034 1035 mlog_exit(ret); 1036 return ret; 1037} 1038 1039static void ocfs2_cluster_unlock(struct ocfs2_super *osb, 1040 struct ocfs2_lock_res *lockres, 1041 int level) 1042{ 1043 unsigned long flags; 1044 1045 mlog_entry_void(); 1046 spin_lock_irqsave(&lockres->l_lock, flags); 1047 ocfs2_dec_holders(lockres, level); 1048 ocfs2_vote_on_unlock(osb, lockres); 1049 spin_unlock_irqrestore(&lockres->l_lock, flags); 1050 mlog_exit_void(); 1051} 1052 1053int ocfs2_create_new_lock(struct ocfs2_super *osb, 1054 struct ocfs2_lock_res *lockres, 1055 int ex, 1056 int local) 1057{ 1058 int level = ex ? LKM_EXMODE : LKM_PRMODE; 1059 unsigned long flags; 1060 int lkm_flags = local ? LKM_LOCAL : 0; 1061 1062 spin_lock_irqsave(&lockres->l_lock, flags); 1063 BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED); 1064 lockres_or_flags(lockres, OCFS2_LOCK_LOCAL); 1065 spin_unlock_irqrestore(&lockres->l_lock, flags); 1066 1067 return ocfs2_lock_create(osb, lockres, level, lkm_flags); 1068} 1069 1070/* Grants us an EX lock on the data and metadata resources, skipping 1071 * the normal cluster directory lookup. Use this ONLY on newly created 1072 * inodes which other nodes can't possibly see, and which haven't been 1073 * hashed in the inode hash yet. This can give us a good performance 1074 * increase as it'll skip the network broadcast normally associated 1075 * with creating a new lock resource. */ 1076int ocfs2_create_new_inode_locks(struct inode *inode) 1077{ 1078 int ret; 1079 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1080 1081 BUG_ON(!inode); 1082 BUG_ON(!ocfs2_inode_is_new(inode)); 1083 1084 mlog_entry_void(); 1085 1086 mlog(0, "Inode %llu\n", (unsigned long long)OCFS2_I(inode)->ip_blkno); 1087 1088 /* NOTE: That we don't increment any of the holder counts, nor 1089 * do we add anything to a journal handle. Since this is 1090 * supposed to be a new inode which the cluster doesn't know 1091 * about yet, there is no need to. As far as the LVB handling 1092 * is concerned, this is basically like acquiring an EX lock 1093 * on a resource which has an invalid one -- we'll set it 1094 * valid when we release the EX. */ 1095 1096 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_rw_lockres, 1, 1); 1097 if (ret) { 1098 mlog_errno(ret); 1099 goto bail; 1100 } 1101 1102 /* 1103 * We don't want to use LKM_LOCAL on a meta data lock as they 1104 * don't use a generation in their lock names. 1105 */ 1106 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_meta_lockres, 1, 0); 1107 if (ret) { 1108 mlog_errno(ret); 1109 goto bail; 1110 } 1111 1112 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_data_lockres, 1, 1); 1113 if (ret) { 1114 mlog_errno(ret); 1115 goto bail; 1116 } 1117 1118bail: 1119 mlog_exit(ret); 1120 return ret; 1121} 1122 1123int ocfs2_rw_lock(struct inode *inode, int write) 1124{ 1125 int status, level; 1126 struct ocfs2_lock_res *lockres; 1127 1128 BUG_ON(!inode); 1129 1130 mlog_entry_void(); 1131 1132 mlog(0, "inode %llu take %s RW lock\n", 1133 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1134 write ? "EXMODE" : "PRMODE"); 1135 1136 lockres = &OCFS2_I(inode)->ip_rw_lockres; 1137 1138 level = write ? LKM_EXMODE : LKM_PRMODE; 1139 1140 status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres, level, 0, 1141 0); 1142 if (status < 0) 1143 mlog_errno(status); 1144 1145 mlog_exit(status); 1146 return status; 1147} 1148 1149void ocfs2_rw_unlock(struct inode *inode, int write) 1150{ 1151 int level = write ? LKM_EXMODE : LKM_PRMODE; 1152 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_rw_lockres; 1153 1154 mlog_entry_void(); 1155 1156 mlog(0, "inode %llu drop %s RW lock\n", 1157 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1158 write ? "EXMODE" : "PRMODE"); 1159 1160 ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level); 1161 1162 mlog_exit_void(); 1163} 1164 1165int ocfs2_data_lock_full(struct inode *inode, 1166 int write, 1167 int arg_flags) 1168{ 1169 int status = 0, level; 1170 struct ocfs2_lock_res *lockres; 1171 1172 BUG_ON(!inode); 1173 1174 mlog_entry_void(); 1175 1176 mlog(0, "inode %llu take %s DATA lock\n", 1177 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1178 write ? "EXMODE" : "PRMODE"); 1179 1180 /* We'll allow faking a readonly data lock for 1181 * rodevices. */ 1182 if (ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb))) { 1183 if (write) { 1184 status = -EROFS; 1185 mlog_errno(status); 1186 } 1187 goto out; 1188 } 1189 1190 lockres = &OCFS2_I(inode)->ip_data_lockres; 1191 1192 level = write ? LKM_EXMODE : LKM_PRMODE; 1193 1194 status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres, level, 1195 0, arg_flags); 1196 if (status < 0 && status != -EAGAIN) 1197 mlog_errno(status); 1198 1199out: 1200 mlog_exit(status); 1201 return status; 1202} 1203 1204/* see ocfs2_meta_lock_with_page() */ 1205int ocfs2_data_lock_with_page(struct inode *inode, 1206 int write, 1207 struct page *page) 1208{ 1209 int ret; 1210 1211 ret = ocfs2_data_lock_full(inode, write, OCFS2_LOCK_NONBLOCK); 1212 if (ret == -EAGAIN) { 1213 unlock_page(page); 1214 if (ocfs2_data_lock(inode, write) == 0) 1215 ocfs2_data_unlock(inode, write); 1216 ret = AOP_TRUNCATED_PAGE; 1217 } 1218 1219 return ret; 1220} 1221 1222static void ocfs2_vote_on_unlock(struct ocfs2_super *osb, 1223 struct ocfs2_lock_res *lockres) 1224{ 1225 int kick = 0; 1226 1227 mlog_entry_void(); 1228 1229 /* If we know that another node is waiting on our lock, kick 1230 * the vote thread * pre-emptively when we reach a release 1231 * condition. */ 1232 if (lockres->l_flags & OCFS2_LOCK_BLOCKED) { 1233 switch(lockres->l_blocking) { 1234 case LKM_EXMODE: 1235 if (!lockres->l_ex_holders && !lockres->l_ro_holders) 1236 kick = 1; 1237 break; 1238 case LKM_PRMODE: 1239 if (!lockres->l_ex_holders) 1240 kick = 1; 1241 break; 1242 default: 1243 BUG(); 1244 } 1245 } 1246 1247 if (kick) 1248 ocfs2_kick_vote_thread(osb); 1249 1250 mlog_exit_void(); 1251} 1252 1253void ocfs2_data_unlock(struct inode *inode, 1254 int write) 1255{ 1256 int level = write ? LKM_EXMODE : LKM_PRMODE; 1257 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_data_lockres; 1258 1259 mlog_entry_void(); 1260 1261 mlog(0, "inode %llu drop %s DATA lock\n", 1262 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1263 write ? "EXMODE" : "PRMODE"); 1264 1265 if (!ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb))) 1266 ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level); 1267 1268 mlog_exit_void(); 1269} 1270 1271#define OCFS2_SEC_BITS 34 1272#define OCFS2_SEC_SHIFT (64 - 34) 1273#define OCFS2_NSEC_MASK ((1ULL << OCFS2_SEC_SHIFT) - 1) 1274 1275/* LVB only has room for 64 bits of time here so we pack it for 1276 * now. */ 1277static u64 ocfs2_pack_timespec(struct timespec *spec) 1278{ 1279 u64 res; 1280 u64 sec = spec->tv_sec; 1281 u32 nsec = spec->tv_nsec; 1282 1283 res = (sec << OCFS2_SEC_SHIFT) | (nsec & OCFS2_NSEC_MASK); 1284 1285 return res; 1286} 1287 1288/* Call this with the lockres locked. I am reasonably sure we don't 1289 * need ip_lock in this function as anyone who would be changing those 1290 * values is supposed to be blocked in ocfs2_meta_lock right now. */ 1291static void __ocfs2_stuff_meta_lvb(struct inode *inode) 1292{ 1293 struct ocfs2_inode_info *oi = OCFS2_I(inode); 1294 struct ocfs2_lock_res *lockres = &oi->ip_meta_lockres; 1295 struct ocfs2_meta_lvb *lvb; 1296 1297 mlog_entry_void(); 1298 1299 lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb; 1300 1301 /* 1302 * Invalidate the LVB of a deleted inode - this way other 1303 * nodes are forced to go to disk and discover the new inode 1304 * status. 1305 */ 1306 if (oi->ip_flags & OCFS2_INODE_DELETED) { 1307 lvb->lvb_version = 0; 1308 goto out; 1309 } 1310 1311 lvb->lvb_version = OCFS2_LVB_VERSION; 1312 lvb->lvb_isize = cpu_to_be64(i_size_read(inode)); 1313 lvb->lvb_iclusters = cpu_to_be32(oi->ip_clusters); 1314 lvb->lvb_iuid = cpu_to_be32(inode->i_uid); 1315 lvb->lvb_igid = cpu_to_be32(inode->i_gid); 1316 lvb->lvb_imode = cpu_to_be16(inode->i_mode); 1317 lvb->lvb_inlink = cpu_to_be16(inode->i_nlink); 1318 lvb->lvb_iatime_packed = 1319 cpu_to_be64(ocfs2_pack_timespec(&inode->i_atime)); 1320 lvb->lvb_ictime_packed = 1321 cpu_to_be64(ocfs2_pack_timespec(&inode->i_ctime)); 1322 lvb->lvb_imtime_packed = 1323 cpu_to_be64(ocfs2_pack_timespec(&inode->i_mtime)); 1324 lvb->lvb_iattr = cpu_to_be32(oi->ip_attr); 1325 lvb->lvb_igeneration = cpu_to_be32(inode->i_generation); 1326 1327out: 1328 mlog_meta_lvb(0, lockres); 1329 1330 mlog_exit_void(); 1331} 1332 1333static void ocfs2_unpack_timespec(struct timespec *spec, 1334 u64 packed_time) 1335{ 1336 spec->tv_sec = packed_time >> OCFS2_SEC_SHIFT; 1337 spec->tv_nsec = packed_time & OCFS2_NSEC_MASK; 1338} 1339 1340static void ocfs2_refresh_inode_from_lvb(struct inode *inode) 1341{ 1342 struct ocfs2_inode_info *oi = OCFS2_I(inode); 1343 struct ocfs2_lock_res *lockres = &oi->ip_meta_lockres; 1344 struct ocfs2_meta_lvb *lvb; 1345 1346 mlog_entry_void(); 1347 1348 mlog_meta_lvb(0, lockres); 1349 1350 lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb; 1351 1352 /* We're safe here without the lockres lock... */ 1353 spin_lock(&oi->ip_lock); 1354 oi->ip_clusters = be32_to_cpu(lvb->lvb_iclusters); 1355 i_size_write(inode, be64_to_cpu(lvb->lvb_isize)); 1356 1357 oi->ip_attr = be32_to_cpu(lvb->lvb_iattr); 1358 ocfs2_set_inode_flags(inode); 1359 1360 /* fast-symlinks are a special case */ 1361 if (S_ISLNK(inode->i_mode) && !oi->ip_clusters) 1362 inode->i_blocks = 0; 1363 else 1364 inode->i_blocks = 1365 ocfs2_align_bytes_to_sectors(i_size_read(inode)); 1366 1367 inode->i_uid = be32_to_cpu(lvb->lvb_iuid); 1368 inode->i_gid = be32_to_cpu(lvb->lvb_igid); 1369 inode->i_mode = be16_to_cpu(lvb->lvb_imode); 1370 inode->i_nlink = be16_to_cpu(lvb->lvb_inlink); 1371 ocfs2_unpack_timespec(&inode->i_atime, 1372 be64_to_cpu(lvb->lvb_iatime_packed)); 1373 ocfs2_unpack_timespec(&inode->i_mtime, 1374 be64_to_cpu(lvb->lvb_imtime_packed)); 1375 ocfs2_unpack_timespec(&inode->i_ctime, 1376 be64_to_cpu(lvb->lvb_ictime_packed)); 1377 spin_unlock(&oi->ip_lock); 1378 1379 mlog_exit_void(); 1380} 1381 1382static inline int ocfs2_meta_lvb_is_trustable(struct inode *inode, 1383 struct ocfs2_lock_res *lockres) 1384{ 1385 struct ocfs2_meta_lvb *lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb; 1386 1387 if (lvb->lvb_version == OCFS2_LVB_VERSION 1388 && be32_to_cpu(lvb->lvb_igeneration) == inode->i_generation) 1389 return 1; 1390 return 0; 1391} 1392 1393/* Determine whether a lock resource needs to be refreshed, and 1394 * arbitrate who gets to refresh it. 1395 * 1396 * 0 means no refresh needed. 1397 * 1398 * > 0 means you need to refresh this and you MUST call 1399 * ocfs2_complete_lock_res_refresh afterwards. */ 1400static int ocfs2_should_refresh_lock_res(struct ocfs2_lock_res *lockres) 1401{ 1402 unsigned long flags; 1403 int status = 0; 1404 1405 mlog_entry_void(); 1406 1407refresh_check: 1408 spin_lock_irqsave(&lockres->l_lock, flags); 1409 if (!(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) { 1410 spin_unlock_irqrestore(&lockres->l_lock, flags); 1411 goto bail; 1412 } 1413 1414 if (lockres->l_flags & OCFS2_LOCK_REFRESHING) { 1415 spin_unlock_irqrestore(&lockres->l_lock, flags); 1416 1417 ocfs2_wait_on_refreshing_lock(lockres); 1418 goto refresh_check; 1419 } 1420 1421 /* Ok, I'll be the one to refresh this lock. */ 1422 lockres_or_flags(lockres, OCFS2_LOCK_REFRESHING); 1423 spin_unlock_irqrestore(&lockres->l_lock, flags); 1424 1425 status = 1; 1426bail: 1427 mlog_exit(status); 1428 return status; 1429} 1430 1431/* If status is non zero, I'll mark it as not being in refresh 1432 * anymroe, but i won't clear the needs refresh flag. */ 1433static inline void ocfs2_complete_lock_res_refresh(struct ocfs2_lock_res *lockres, 1434 int status) 1435{ 1436 unsigned long flags; 1437 mlog_entry_void(); 1438 1439 spin_lock_irqsave(&lockres->l_lock, flags); 1440 lockres_clear_flags(lockres, OCFS2_LOCK_REFRESHING); 1441 if (!status) 1442 lockres_clear_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH); 1443 spin_unlock_irqrestore(&lockres->l_lock, flags); 1444 1445 wake_up(&lockres->l_event); 1446 1447 mlog_exit_void(); 1448} 1449 1450/* may or may not return a bh if it went to disk. */ 1451static int ocfs2_meta_lock_update(struct inode *inode, 1452 struct buffer_head **bh) 1453{ 1454 int status = 0; 1455 struct ocfs2_inode_info *oi = OCFS2_I(inode); 1456 struct ocfs2_lock_res *lockres; 1457 struct ocfs2_dinode *fe; 1458 1459 mlog_entry_void(); 1460 1461 spin_lock(&oi->ip_lock); 1462 if (oi->ip_flags & OCFS2_INODE_DELETED) { 1463 mlog(0, "Orphaned inode %llu was deleted while we " 1464 "were waiting on a lock. ip_flags = 0x%x\n", 1465 (unsigned long long)oi->ip_blkno, oi->ip_flags); 1466 spin_unlock(&oi->ip_lock); 1467 status = -ENOENT; 1468 goto bail; 1469 } 1470 spin_unlock(&oi->ip_lock); 1471 1472 lockres = &oi->ip_meta_lockres; 1473 1474 if (!ocfs2_should_refresh_lock_res(lockres)) 1475 goto bail; 1476 1477 /* This will discard any caching information we might have had 1478 * for the inode metadata. */ 1479 ocfs2_metadata_cache_purge(inode); 1480 1481 /* will do nothing for inode types that don't use the extent 1482 * map (directories, bitmap files, etc) */ 1483 ocfs2_extent_map_trunc(inode, 0); 1484 1485 if (ocfs2_meta_lvb_is_trustable(inode, lockres)) { 1486 mlog(0, "Trusting LVB on inode %llu\n", 1487 (unsigned long long)oi->ip_blkno); 1488 ocfs2_refresh_inode_from_lvb(inode); 1489 } else { 1490 /* Boo, we have to go to disk. */ 1491 /* read bh, cast, ocfs2_refresh_inode */ 1492 status = ocfs2_read_block(OCFS2_SB(inode->i_sb), oi->ip_blkno, 1493 bh, OCFS2_BH_CACHED, inode); 1494 if (status < 0) { 1495 mlog_errno(status); 1496 goto bail_refresh; 1497 } 1498 fe = (struct ocfs2_dinode *) (*bh)->b_data; 1499 1500 /* This is a good chance to make sure we're not 1501 * locking an invalid object. 1502 * 1503 * We bug on a stale inode here because we checked 1504 * above whether it was wiped from disk. The wiping 1505 * node provides a guarantee that we receive that 1506 * message and can mark the inode before dropping any 1507 * locks associated with it. */ 1508 if (!OCFS2_IS_VALID_DINODE(fe)) { 1509 OCFS2_RO_ON_INVALID_DINODE(inode->i_sb, fe); 1510 status = -EIO; 1511 goto bail_refresh; 1512 } 1513 mlog_bug_on_msg(inode->i_generation != 1514 le32_to_cpu(fe->i_generation), 1515 "Invalid dinode %llu disk generation: %u " 1516 "inode->i_generation: %u\n", 1517 (unsigned long long)oi->ip_blkno, 1518 le32_to_cpu(fe->i_generation), 1519 inode->i_generation); 1520 mlog_bug_on_msg(le64_to_cpu(fe->i_dtime) || 1521 !(fe->i_flags & cpu_to_le32(OCFS2_VALID_FL)), 1522 "Stale dinode %llu dtime: %llu flags: 0x%x\n", 1523 (unsigned long long)oi->ip_blkno, 1524 (unsigned long long)le64_to_cpu(fe->i_dtime), 1525 le32_to_cpu(fe->i_flags)); 1526 1527 ocfs2_refresh_inode(inode, fe); 1528 } 1529 1530 status = 0; 1531bail_refresh: 1532 ocfs2_complete_lock_res_refresh(lockres, status); 1533bail: 1534 mlog_exit(status); 1535 return status; 1536} 1537 1538static int ocfs2_assign_bh(struct inode *inode, 1539 struct buffer_head **ret_bh, 1540 struct buffer_head *passed_bh) 1541{ 1542 int status; 1543 1544 if (passed_bh) { 1545 /* Ok, the update went to disk for us, use the 1546 * returned bh. */ 1547 *ret_bh = passed_bh; 1548 get_bh(*ret_bh); 1549 1550 return 0; 1551 } 1552 1553 status = ocfs2_read_block(OCFS2_SB(inode->i_sb), 1554 OCFS2_I(inode)->ip_blkno, 1555 ret_bh, 1556 OCFS2_BH_CACHED, 1557 inode); 1558 if (status < 0) 1559 mlog_errno(status); 1560 1561 return status; 1562} 1563 1564/* 1565 * returns < 0 error if the callback will never be called, otherwise 1566 * the result of the lock will be communicated via the callback. 1567 */ 1568int ocfs2_meta_lock_full(struct inode *inode, 1569 struct ocfs2_journal_handle *handle, 1570 struct buffer_head **ret_bh, 1571 int ex, 1572 int arg_flags) 1573{ 1574 int status, level, dlm_flags, acquired; 1575 struct ocfs2_lock_res *lockres; 1576 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1577 struct buffer_head *local_bh = NULL; 1578 1579 BUG_ON(!inode); 1580 1581 mlog_entry_void(); 1582 1583 mlog(0, "inode %llu, take %s META lock\n", 1584 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1585 ex ? "EXMODE" : "PRMODE"); 1586 1587 status = 0; 1588 acquired = 0; 1589 /* We'll allow faking a readonly metadata lock for 1590 * rodevices. */ 1591 if (ocfs2_is_hard_readonly(osb)) { 1592 if (ex) 1593 status = -EROFS; 1594 goto bail; 1595 } 1596 1597 if (!(arg_flags & OCFS2_META_LOCK_RECOVERY)) 1598 wait_event(osb->recovery_event, 1599 ocfs2_node_map_is_empty(osb, &osb->recovery_map)); 1600 1601 acquired = 0; 1602 lockres = &OCFS2_I(inode)->ip_meta_lockres; 1603 level = ex ? LKM_EXMODE : LKM_PRMODE; 1604 dlm_flags = 0; 1605 if (arg_flags & OCFS2_META_LOCK_NOQUEUE) 1606 dlm_flags |= LKM_NOQUEUE; 1607 1608 status = ocfs2_cluster_lock(osb, lockres, level, dlm_flags, arg_flags); 1609 if (status < 0) { 1610 if (status != -EAGAIN && status != -EIOCBRETRY) 1611 mlog_errno(status); 1612 goto bail; 1613 } 1614 1615 /* Notify the error cleanup path to drop the cluster lock. */ 1616 acquired = 1; 1617 1618 /* We wait twice because a node may have died while we were in 1619 * the lower dlm layers. The second time though, we've 1620 * committed to owning this lock so we don't allow signals to 1621 * abort the operation. */ 1622 if (!(arg_flags & OCFS2_META_LOCK_RECOVERY)) 1623 wait_event(osb->recovery_event, 1624 ocfs2_node_map_is_empty(osb, &osb->recovery_map)); 1625 1626 /* 1627 * We only see this flag if we're being called from 1628 * ocfs2_read_locked_inode(). It means we're locking an inode 1629 * which hasn't been populated yet, so clear the refresh flag 1630 * and let the caller handle it. 1631 */ 1632 if (inode->i_state & I_NEW) { 1633 status = 0; 1634 ocfs2_complete_lock_res_refresh(lockres, 0); 1635 goto bail; 1636 } 1637 1638 /* This is fun. The caller may want a bh back, or it may 1639 * not. ocfs2_meta_lock_update definitely wants one in, but 1640 * may or may not read one, depending on what's in the 1641 * LVB. The result of all of this is that we've *only* gone to 1642 * disk if we have to, so the complexity is worthwhile. */ 1643 status = ocfs2_meta_lock_update(inode, &local_bh); 1644 if (status < 0) { 1645 if (status != -ENOENT) 1646 mlog_errno(status); 1647 goto bail; 1648 } 1649 1650 if (ret_bh) { 1651 status = ocfs2_assign_bh(inode, ret_bh, local_bh); 1652 if (status < 0) { 1653 mlog_errno(status); 1654 goto bail; 1655 } 1656 } 1657 1658 if (handle) { 1659 status = ocfs2_handle_add_lock(handle, inode); 1660 if (status < 0) 1661 mlog_errno(status); 1662 } 1663 1664bail: 1665 if (status < 0) { 1666 if (ret_bh && (*ret_bh)) { 1667 brelse(*ret_bh); 1668 *ret_bh = NULL; 1669 } 1670 if (acquired) 1671 ocfs2_meta_unlock(inode, ex); 1672 } 1673 1674 if (local_bh) 1675 brelse(local_bh); 1676 1677 mlog_exit(status); 1678 return status; 1679} 1680 1681/* 1682 * This is working around a lock inversion between tasks acquiring DLM locks 1683 * while holding a page lock and the vote thread which blocks dlm lock acquiry 1684 * while acquiring page locks. 1685 * 1686 * ** These _with_page variantes are only intended to be called from aop 1687 * methods that hold page locks and return a very specific *positive* error 1688 * code that aop methods pass up to the VFS -- test for errors with != 0. ** 1689 * 1690 * The DLM is called such that it returns -EAGAIN if it would have blocked 1691 * waiting for the vote thread. In that case we unlock our page so the vote 1692 * thread can make progress. Once we've done this we have to return 1693 * AOP_TRUNCATED_PAGE so the aop method that called us can bubble that back up 1694 * into the VFS who will then immediately retry the aop call. 1695 * 1696 * We do a blocking lock and immediate unlock before returning, though, so that 1697 * the lock has a great chance of being cached on this node by the time the VFS 1698 * calls back to retry the aop. This has a potential to livelock as nodes 1699 * ping locks back and forth, but that's a risk we're willing to take to avoid 1700 * the lock inversion simply. 1701 */ 1702int ocfs2_meta_lock_with_page(struct inode *inode, 1703 struct ocfs2_journal_handle *handle, 1704 struct buffer_head **ret_bh, 1705 int ex, 1706 struct page *page) 1707{ 1708 int ret; 1709 1710 ret = ocfs2_meta_lock_full(inode, handle, ret_bh, ex, 1711 OCFS2_LOCK_NONBLOCK); 1712 if (ret == -EAGAIN) { 1713 unlock_page(page); 1714 if (ocfs2_meta_lock(inode, handle, ret_bh, ex) == 0) 1715 ocfs2_meta_unlock(inode, ex); 1716 ret = AOP_TRUNCATED_PAGE; 1717 } 1718 1719 return ret; 1720} 1721 1722void ocfs2_meta_unlock(struct inode *inode, 1723 int ex) 1724{ 1725 int level = ex ? LKM_EXMODE : LKM_PRMODE; 1726 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_meta_lockres; 1727 1728 mlog_entry_void(); 1729 1730 mlog(0, "inode %llu drop %s META lock\n", 1731 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1732 ex ? "EXMODE" : "PRMODE"); 1733 1734 if (!ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb))) 1735 ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level); 1736 1737 mlog_exit_void(); 1738} 1739 1740int ocfs2_super_lock(struct ocfs2_super *osb, 1741 int ex) 1742{ 1743 int status; 1744 int level = ex ? LKM_EXMODE : LKM_PRMODE; 1745 struct ocfs2_lock_res *lockres = &osb->osb_super_lockres; 1746 struct buffer_head *bh; 1747 struct ocfs2_slot_info *si = osb->slot_info; 1748 1749 mlog_entry_void(); 1750 1751 if (ocfs2_is_hard_readonly(osb)) 1752 return -EROFS; 1753 1754 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0); 1755 if (status < 0) { 1756 mlog_errno(status); 1757 goto bail; 1758 } 1759 1760 /* The super block lock path is really in the best position to 1761 * know when resources covered by the lock need to be 1762 * refreshed, so we do it here. Of course, making sense of 1763 * everything is up to the caller :) */ 1764 status = ocfs2_should_refresh_lock_res(lockres); 1765 if (status < 0) { 1766 mlog_errno(status); 1767 goto bail; 1768 } 1769 if (status) { 1770 bh = si->si_bh; 1771 status = ocfs2_read_block(osb, bh->b_blocknr, &bh, 0, 1772 si->si_inode); 1773 if (status == 0) 1774 ocfs2_update_slot_info(si); 1775 1776 ocfs2_complete_lock_res_refresh(lockres, status); 1777 1778 if (status < 0) 1779 mlog_errno(status); 1780 } 1781bail: 1782 mlog_exit(status); 1783 return status; 1784} 1785 1786void ocfs2_super_unlock(struct ocfs2_super *osb, 1787 int ex) 1788{ 1789 int level = ex ? LKM_EXMODE : LKM_PRMODE; 1790 struct ocfs2_lock_res *lockres = &osb->osb_super_lockres; 1791 1792 ocfs2_cluster_unlock(osb, lockres, level); 1793} 1794 1795int ocfs2_rename_lock(struct ocfs2_super *osb) 1796{ 1797 int status; 1798 struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres; 1799 1800 if (ocfs2_is_hard_readonly(osb)) 1801 return -EROFS; 1802 1803 status = ocfs2_cluster_lock(osb, lockres, LKM_EXMODE, 0, 0); 1804 if (status < 0) 1805 mlog_errno(status); 1806 1807 return status; 1808} 1809 1810void ocfs2_rename_unlock(struct ocfs2_super *osb) 1811{ 1812 struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres; 1813 1814 ocfs2_cluster_unlock(osb, lockres, LKM_EXMODE); 1815} 1816 1817int ocfs2_dentry_lock(struct dentry *dentry, int ex) 1818{ 1819 int ret; 1820 int level = ex ? LKM_EXMODE : LKM_PRMODE; 1821 struct ocfs2_dentry_lock *dl = dentry->d_fsdata; 1822 struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb); 1823 1824 BUG_ON(!dl); 1825 1826 if (ocfs2_is_hard_readonly(osb)) 1827 return -EROFS; 1828 1829 ret = ocfs2_cluster_lock(osb, &dl->dl_lockres, level, 0, 0); 1830 if (ret < 0) 1831 mlog_errno(ret); 1832 1833 return ret; 1834} 1835 1836void ocfs2_dentry_unlock(struct dentry *dentry, int ex) 1837{ 1838 int level = ex ? LKM_EXMODE : LKM_PRMODE; 1839 struct ocfs2_dentry_lock *dl = dentry->d_fsdata; 1840 struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb); 1841 1842 ocfs2_cluster_unlock(osb, &dl->dl_lockres, level); 1843} 1844 1845/* Reference counting of the dlm debug structure. We want this because 1846 * open references on the debug inodes can live on after a mount, so 1847 * we can't rely on the ocfs2_super to always exist. */ 1848static void ocfs2_dlm_debug_free(struct kref *kref) 1849{ 1850 struct ocfs2_dlm_debug *dlm_debug; 1851 1852 dlm_debug = container_of(kref, struct ocfs2_dlm_debug, d_refcnt); 1853 1854 kfree(dlm_debug); 1855} 1856 1857void ocfs2_put_dlm_debug(struct ocfs2_dlm_debug *dlm_debug) 1858{ 1859 if (dlm_debug) 1860 kref_put(&dlm_debug->d_refcnt, ocfs2_dlm_debug_free); 1861} 1862 1863static void ocfs2_get_dlm_debug(struct ocfs2_dlm_debug *debug) 1864{ 1865 kref_get(&debug->d_refcnt); 1866} 1867 1868struct ocfs2_dlm_debug *ocfs2_new_dlm_debug(void) 1869{ 1870 struct ocfs2_dlm_debug *dlm_debug; 1871 1872 dlm_debug = kmalloc(sizeof(struct ocfs2_dlm_debug), GFP_KERNEL); 1873 if (!dlm_debug) { 1874 mlog_errno(-ENOMEM); 1875 goto out; 1876 } 1877 1878 kref_init(&dlm_debug->d_refcnt); 1879 INIT_LIST_HEAD(&dlm_debug->d_lockres_tracking); 1880 dlm_debug->d_locking_state = NULL; 1881out: 1882 return dlm_debug; 1883} 1884 1885/* Access to this is arbitrated for us via seq_file->sem. */ 1886struct ocfs2_dlm_seq_priv { 1887 struct ocfs2_dlm_debug *p_dlm_debug; 1888 struct ocfs2_lock_res p_iter_res; 1889 struct ocfs2_lock_res p_tmp_res; 1890}; 1891 1892static struct ocfs2_lock_res *ocfs2_dlm_next_res(struct ocfs2_lock_res *start, 1893 struct ocfs2_dlm_seq_priv *priv) 1894{ 1895 struct ocfs2_lock_res *iter, *ret = NULL; 1896 struct ocfs2_dlm_debug *dlm_debug = priv->p_dlm_debug; 1897 1898 assert_spin_locked(&ocfs2_dlm_tracking_lock); 1899 1900 list_for_each_entry(iter, &start->l_debug_list, l_debug_list) { 1901 /* discover the head of the list */ 1902 if (&iter->l_debug_list == &dlm_debug->d_lockres_tracking) { 1903 mlog(0, "End of list found, %p\n", ret); 1904 break; 1905 } 1906 1907 /* We track our "dummy" iteration lockres' by a NULL 1908 * l_ops field. */ 1909 if (iter->l_ops != NULL) { 1910 ret = iter; 1911 break; 1912 } 1913 } 1914 1915 return ret; 1916} 1917 1918static void *ocfs2_dlm_seq_start(struct seq_file *m, loff_t *pos) 1919{ 1920 struct ocfs2_dlm_seq_priv *priv = m->private; 1921 struct ocfs2_lock_res *iter; 1922 1923 spin_lock(&ocfs2_dlm_tracking_lock); 1924 iter = ocfs2_dlm_next_res(&priv->p_iter_res, priv); 1925 if (iter) { 1926 /* Since lockres' have the lifetime of their container 1927 * (which can be inodes, ocfs2_supers, etc) we want to 1928 * copy this out to a temporary lockres while still 1929 * under the spinlock. Obviously after this we can't 1930 * trust any pointers on the copy returned, but that's 1931 * ok as the information we want isn't typically held 1932 * in them. */ 1933 priv->p_tmp_res = *iter; 1934 iter = &priv->p_tmp_res; 1935 } 1936 spin_unlock(&ocfs2_dlm_tracking_lock); 1937 1938 return iter; 1939} 1940 1941static void ocfs2_dlm_seq_stop(struct seq_file *m, void *v) 1942{ 1943} 1944 1945static void *ocfs2_dlm_seq_next(struct seq_file *m, void *v, loff_t *pos) 1946{ 1947 struct ocfs2_dlm_seq_priv *priv = m->private; 1948 struct ocfs2_lock_res *iter = v; 1949 struct ocfs2_lock_res *dummy = &priv->p_iter_res; 1950 1951 spin_lock(&ocfs2_dlm_tracking_lock); 1952 iter = ocfs2_dlm_next_res(iter, priv); 1953 list_del_init(&dummy->l_debug_list); 1954 if (iter) { 1955 list_add(&dummy->l_debug_list, &iter->l_debug_list); 1956 priv->p_tmp_res = *iter; 1957 iter = &priv->p_tmp_res; 1958 } 1959 spin_unlock(&ocfs2_dlm_tracking_lock); 1960 1961 return iter; 1962} 1963 1964/* So that debugfs.ocfs2 can determine which format is being used */ 1965#define OCFS2_DLM_DEBUG_STR_VERSION 1 1966static int ocfs2_dlm_seq_show(struct seq_file *m, void *v) 1967{ 1968 int i; 1969 char *lvb; 1970 struct ocfs2_lock_res *lockres = v; 1971 1972 if (!lockres) 1973 return -EINVAL; 1974 1975 seq_printf(m, "0x%x\t", OCFS2_DLM_DEBUG_STR_VERSION); 1976 1977 if (lockres->l_type == OCFS2_LOCK_TYPE_DENTRY) 1978 seq_printf(m, "%.*s%08x\t", OCFS2_DENTRY_LOCK_INO_START - 1, 1979 lockres->l_name, 1980 (unsigned int)ocfs2_get_dentry_lock_ino(lockres)); 1981 else 1982 seq_printf(m, "%.*s\t", OCFS2_LOCK_ID_MAX_LEN, lockres->l_name); 1983 1984 seq_printf(m, "%d\t" 1985 "0x%lx\t" 1986 "0x%x\t" 1987 "0x%x\t" 1988 "%u\t" 1989 "%u\t" 1990 "%d\t" 1991 "%d\t", 1992 lockres->l_level, 1993 lockres->l_flags, 1994 lockres->l_action, 1995 lockres->l_unlock_action, 1996 lockres->l_ro_holders, 1997 lockres->l_ex_holders, 1998 lockres->l_requested, 1999 lockres->l_blocking); 2000 2001 /* Dump the raw LVB */ 2002 lvb = lockres->l_lksb.lvb; 2003 for(i = 0; i < DLM_LVB_LEN; i++) 2004 seq_printf(m, "0x%x\t", lvb[i]); 2005 2006 /* End the line */ 2007 seq_printf(m, "\n"); 2008 return 0; 2009} 2010 2011static struct seq_operations ocfs2_dlm_seq_ops = { 2012 .start = ocfs2_dlm_seq_start, 2013 .stop = ocfs2_dlm_seq_stop, 2014 .next = ocfs2_dlm_seq_next, 2015 .show = ocfs2_dlm_seq_show, 2016}; 2017 2018static int ocfs2_dlm_debug_release(struct inode *inode, struct file *file) 2019{ 2020 struct seq_file *seq = (struct seq_file *) file->private_data; 2021 struct ocfs2_dlm_seq_priv *priv = seq->private; 2022 struct ocfs2_lock_res *res = &priv->p_iter_res; 2023 2024 ocfs2_remove_lockres_tracking(res); 2025 ocfs2_put_dlm_debug(priv->p_dlm_debug); 2026 return seq_release_private(inode, file); 2027} 2028 2029static int ocfs2_dlm_debug_open(struct inode *inode, struct file *file) 2030{ 2031 int ret; 2032 struct ocfs2_dlm_seq_priv *priv; 2033 struct seq_file *seq; 2034 struct ocfs2_super *osb; 2035 2036 priv = kzalloc(sizeof(struct ocfs2_dlm_seq_priv), GFP_KERNEL); 2037 if (!priv) { 2038 ret = -ENOMEM; 2039 mlog_errno(ret); 2040 goto out; 2041 } 2042 osb = (struct ocfs2_super *) inode->u.generic_ip; 2043 ocfs2_get_dlm_debug(osb->osb_dlm_debug); 2044 priv->p_dlm_debug = osb->osb_dlm_debug; 2045 INIT_LIST_HEAD(&priv->p_iter_res.l_debug_list); 2046 2047 ret = seq_open(file, &ocfs2_dlm_seq_ops); 2048 if (ret) { 2049 kfree(priv); 2050 mlog_errno(ret); 2051 goto out; 2052 } 2053 2054 seq = (struct seq_file *) file->private_data; 2055 seq->private = priv; 2056 2057 ocfs2_add_lockres_tracking(&priv->p_iter_res, 2058 priv->p_dlm_debug); 2059 2060out: 2061 return ret; 2062} 2063 2064static const struct file_operations ocfs2_dlm_debug_fops = { 2065 .open = ocfs2_dlm_debug_open, 2066 .release = ocfs2_dlm_debug_release, 2067 .read = seq_read, 2068 .llseek = seq_lseek, 2069}; 2070 2071static int ocfs2_dlm_init_debug(struct ocfs2_super *osb) 2072{ 2073 int ret = 0; 2074 struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug; 2075 2076 dlm_debug->d_locking_state = debugfs_create_file("locking_state", 2077 S_IFREG|S_IRUSR, 2078 osb->osb_debug_root, 2079 osb, 2080 &ocfs2_dlm_debug_fops); 2081 if (!dlm_debug->d_locking_state) { 2082 ret = -EINVAL; 2083 mlog(ML_ERROR, 2084 "Unable to create locking state debugfs file.\n"); 2085 goto out; 2086 } 2087 2088 ocfs2_get_dlm_debug(dlm_debug); 2089out: 2090 return ret; 2091} 2092 2093static void ocfs2_dlm_shutdown_debug(struct ocfs2_super *osb) 2094{ 2095 struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug; 2096 2097 if (dlm_debug) { 2098 debugfs_remove(dlm_debug->d_locking_state); 2099 ocfs2_put_dlm_debug(dlm_debug); 2100 } 2101} 2102 2103int ocfs2_dlm_init(struct ocfs2_super *osb) 2104{ 2105 int status; 2106 u32 dlm_key; 2107 struct dlm_ctxt *dlm; 2108 2109 mlog_entry_void(); 2110 2111 status = ocfs2_dlm_init_debug(osb); 2112 if (status < 0) { 2113 mlog_errno(status); 2114 goto bail; 2115 } 2116 2117 /* launch vote thread */ 2118 osb->vote_task = kthread_run(ocfs2_vote_thread, osb, "ocfs2vote"); 2119 if (IS_ERR(osb->vote_task)) { 2120 status = PTR_ERR(osb->vote_task); 2121 osb->vote_task = NULL; 2122 mlog_errno(status); 2123 goto bail; 2124 } 2125 2126 /* used by the dlm code to make message headers unique, each 2127 * node in this domain must agree on this. */ 2128 dlm_key = crc32_le(0, osb->uuid_str, strlen(osb->uuid_str)); 2129 2130 /* for now, uuid == domain */ 2131 dlm = dlm_register_domain(osb->uuid_str, dlm_key); 2132 if (IS_ERR(dlm)) { 2133 status = PTR_ERR(dlm); 2134 mlog_errno(status); 2135 goto bail; 2136 } 2137 2138 ocfs2_super_lock_res_init(&osb->osb_super_lockres, osb); 2139 ocfs2_rename_lock_res_init(&osb->osb_rename_lockres, osb); 2140 2141 dlm_register_eviction_cb(dlm, &osb->osb_eviction_cb); 2142 2143 osb->dlm = dlm; 2144 2145 status = 0; 2146bail: 2147 if (status < 0) { 2148 ocfs2_dlm_shutdown_debug(osb); 2149 if (osb->vote_task) 2150 kthread_stop(osb->vote_task); 2151 } 2152 2153 mlog_exit(status); 2154 return status; 2155} 2156 2157void ocfs2_dlm_shutdown(struct ocfs2_super *osb) 2158{ 2159 mlog_entry_void(); 2160 2161 dlm_unregister_eviction_cb(&osb->osb_eviction_cb); 2162 2163 ocfs2_drop_osb_locks(osb); 2164 2165 if (osb->vote_task) { 2166 kthread_stop(osb->vote_task); 2167 osb->vote_task = NULL; 2168 } 2169 2170 ocfs2_lock_res_free(&osb->osb_super_lockres); 2171 ocfs2_lock_res_free(&osb->osb_rename_lockres); 2172 2173 dlm_unregister_domain(osb->dlm); 2174 osb->dlm = NULL; 2175 2176 ocfs2_dlm_shutdown_debug(osb); 2177 2178 mlog_exit_void(); 2179} 2180 2181static void ocfs2_unlock_ast(void *opaque, enum dlm_status status) 2182{ 2183 struct ocfs2_lock_res *lockres = opaque; 2184 unsigned long flags; 2185 2186 mlog_entry_void(); 2187 2188 mlog(0, "UNLOCK AST called on lock %s, action = %d\n", lockres->l_name, 2189 lockres->l_unlock_action); 2190 2191 spin_lock_irqsave(&lockres->l_lock, flags); 2192 /* We tried to cancel a convert request, but it was already 2193 * granted. All we want to do here is clear our unlock 2194 * state. The wake_up call done at the bottom is redundant 2195 * (ocfs2_prepare_cancel_convert doesn't sleep on this) but doesn't 2196 * hurt anything anyway */ 2197 if (status == DLM_CANCELGRANT && 2198 lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) { 2199 mlog(0, "Got cancelgrant for %s\n", lockres->l_name); 2200 2201 /* We don't clear the busy flag in this case as it 2202 * should have been cleared by the ast which the dlm 2203 * has called. */ 2204 goto complete_unlock; 2205 } 2206 2207 if (status != DLM_NORMAL) { 2208 mlog(ML_ERROR, "Dlm passes status %d for lock %s, " 2209 "unlock_action %d\n", status, lockres->l_name, 2210 lockres->l_unlock_action); 2211 spin_unlock_irqrestore(&lockres->l_lock, flags); 2212 return; 2213 } 2214 2215 switch(lockres->l_unlock_action) { 2216 case OCFS2_UNLOCK_CANCEL_CONVERT: 2217 mlog(0, "Cancel convert success for %s\n", lockres->l_name); 2218 lockres->l_action = OCFS2_AST_INVALID; 2219 break; 2220 case OCFS2_UNLOCK_DROP_LOCK: 2221 lockres->l_level = LKM_IVMODE; 2222 break; 2223 default: 2224 BUG(); 2225 } 2226 2227 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); 2228complete_unlock: 2229 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID; 2230 spin_unlock_irqrestore(&lockres->l_lock, flags); 2231 2232 wake_up(&lockres->l_event); 2233 2234 mlog_exit_void(); 2235} 2236 2237typedef void (ocfs2_pre_drop_cb_t)(struct ocfs2_lock_res *, void *); 2238 2239struct drop_lock_cb { 2240 ocfs2_pre_drop_cb_t *drop_func; 2241 void *drop_data; 2242}; 2243 2244static int ocfs2_drop_lock(struct ocfs2_super *osb, 2245 struct ocfs2_lock_res *lockres, 2246 struct drop_lock_cb *dcb) 2247{ 2248 enum dlm_status status; 2249 unsigned long flags; 2250 int lkm_flags = 0; 2251 2252 /* We didn't get anywhere near actually using this lockres. */ 2253 if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED)) 2254 goto out; 2255 2256 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) 2257 lkm_flags |= LKM_VALBLK; 2258 2259 spin_lock_irqsave(&lockres->l_lock, flags); 2260 2261 mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_FREEING), 2262 "lockres %s, flags 0x%lx\n", 2263 lockres->l_name, lockres->l_flags); 2264 2265 while (lockres->l_flags & OCFS2_LOCK_BUSY) { 2266 mlog(0, "waiting on busy lock \"%s\": flags = %lx, action = " 2267 "%u, unlock_action = %u\n", 2268 lockres->l_name, lockres->l_flags, lockres->l_action, 2269 lockres->l_unlock_action); 2270 2271 spin_unlock_irqrestore(&lockres->l_lock, flags); 2272 2273 /* XXX: Today we just wait on any busy 2274 * locks... Perhaps we need to cancel converts in the 2275 * future? */ 2276 ocfs2_wait_on_busy_lock(lockres); 2277 2278 spin_lock_irqsave(&lockres->l_lock, flags); 2279 } 2280 2281 if (dcb) 2282 dcb->drop_func(lockres, dcb->drop_data); 2283 2284 if (lockres->l_flags & OCFS2_LOCK_BUSY) 2285 mlog(ML_ERROR, "destroying busy lock: \"%s\"\n", 2286 lockres->l_name); 2287 if (lockres->l_flags & OCFS2_LOCK_BLOCKED) 2288 mlog(0, "destroying blocked lock: \"%s\"\n", lockres->l_name); 2289 2290 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) { 2291 spin_unlock_irqrestore(&lockres->l_lock, flags); 2292 goto out; 2293 } 2294 2295 lockres_clear_flags(lockres, OCFS2_LOCK_ATTACHED); 2296 2297 /* make sure we never get here while waiting for an ast to 2298 * fire. */ 2299 BUG_ON(lockres->l_action != OCFS2_AST_INVALID); 2300 2301 /* is this necessary? */ 2302 lockres_or_flags(lockres, OCFS2_LOCK_BUSY); 2303 lockres->l_unlock_action = OCFS2_UNLOCK_DROP_LOCK; 2304 spin_unlock_irqrestore(&lockres->l_lock, flags); 2305 2306 mlog(0, "lock %s\n", lockres->l_name); 2307 2308 status = dlmunlock(osb->dlm, &lockres->l_lksb, lkm_flags, 2309 ocfs2_unlock_ast, lockres); 2310 if (status != DLM_NORMAL) { 2311 ocfs2_log_dlm_error("dlmunlock", status, lockres); 2312 mlog(ML_ERROR, "lockres flags: %lu\n", lockres->l_flags); 2313 dlm_print_one_lock(lockres->l_lksb.lockid); 2314 BUG(); 2315 } 2316 mlog(0, "lock %s, successfull return from dlmunlock\n", 2317 lockres->l_name); 2318 2319 ocfs2_wait_on_busy_lock(lockres); 2320out: 2321 mlog_exit(0); 2322 return 0; 2323} 2324 2325/* Mark the lockres as being dropped. It will no longer be 2326 * queued if blocking, but we still may have to wait on it 2327 * being dequeued from the vote thread before we can consider 2328 * it safe to drop. 2329 * 2330 * You can *not* attempt to call cluster_lock on this lockres anymore. */ 2331void ocfs2_mark_lockres_freeing(struct ocfs2_lock_res *lockres) 2332{ 2333 int status; 2334 struct ocfs2_mask_waiter mw; 2335 unsigned long flags; 2336 2337 ocfs2_init_mask_waiter(&mw); 2338 2339 spin_lock_irqsave(&lockres->l_lock, flags); 2340 lockres->l_flags |= OCFS2_LOCK_FREEING; 2341 while (lockres->l_flags & OCFS2_LOCK_QUEUED) { 2342 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_QUEUED, 0); 2343 spin_unlock_irqrestore(&lockres->l_lock, flags); 2344 2345 mlog(0, "Waiting on lockres %s\n", lockres->l_name); 2346 2347 status = ocfs2_wait_for_mask(&mw); 2348 if (status) 2349 mlog_errno(status); 2350 2351 spin_lock_irqsave(&lockres->l_lock, flags); 2352 } 2353 spin_unlock_irqrestore(&lockres->l_lock, flags); 2354} 2355 2356void ocfs2_simple_drop_lockres(struct ocfs2_super *osb, 2357 struct ocfs2_lock_res *lockres) 2358{ 2359 int ret; 2360 2361 ocfs2_mark_lockres_freeing(lockres); 2362 ret = ocfs2_drop_lock(osb, lockres, NULL); 2363 if (ret) 2364 mlog_errno(ret); 2365} 2366 2367static void ocfs2_drop_osb_locks(struct ocfs2_super *osb) 2368{ 2369 ocfs2_simple_drop_lockres(osb, &osb->osb_super_lockres); 2370 ocfs2_simple_drop_lockres(osb, &osb->osb_rename_lockres); 2371} 2372 2373static void ocfs2_meta_pre_drop(struct ocfs2_lock_res *lockres, void *data) 2374{ 2375 struct inode *inode = data; 2376 2377 /* the metadata lock requires a bit more work as we have an 2378 * LVB to worry about. */ 2379 if (lockres->l_flags & OCFS2_LOCK_ATTACHED && 2380 lockres->l_level == LKM_EXMODE && 2381 !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) 2382 __ocfs2_stuff_meta_lvb(inode); 2383} 2384 2385int ocfs2_drop_inode_locks(struct inode *inode) 2386{ 2387 int status, err; 2388 struct drop_lock_cb meta_dcb = { ocfs2_meta_pre_drop, inode, }; 2389 2390 mlog_entry_void(); 2391 2392 /* No need to call ocfs2_mark_lockres_freeing here - 2393 * ocfs2_clear_inode has done it for us. */ 2394 2395 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb), 2396 &OCFS2_I(inode)->ip_data_lockres, 2397 NULL); 2398 if (err < 0) 2399 mlog_errno(err); 2400 2401 status = err; 2402 2403 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb), 2404 &OCFS2_I(inode)->ip_meta_lockres, 2405 &meta_dcb); 2406 if (err < 0) 2407 mlog_errno(err); 2408 if (err < 0 && !status) 2409 status = err; 2410 2411 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb), 2412 &OCFS2_I(inode)->ip_rw_lockres, 2413 NULL); 2414 if (err < 0) 2415 mlog_errno(err); 2416 if (err < 0 && !status) 2417 status = err; 2418 2419 mlog_exit(status); 2420 return status; 2421} 2422 2423static void ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres, 2424 int new_level) 2425{ 2426 assert_spin_locked(&lockres->l_lock); 2427 2428 BUG_ON(lockres->l_blocking <= LKM_NLMODE); 2429 2430 if (lockres->l_level <= new_level) { 2431 mlog(ML_ERROR, "lockres->l_level (%u) <= new_level (%u)\n", 2432 lockres->l_level, new_level); 2433 BUG(); 2434 } 2435 2436 mlog(0, "lock %s, new_level = %d, l_blocking = %d\n", 2437 lockres->l_name, new_level, lockres->l_blocking); 2438 2439 lockres->l_action = OCFS2_AST_DOWNCONVERT; 2440 lockres->l_requested = new_level; 2441 lockres_or_flags(lockres, OCFS2_LOCK_BUSY); 2442} 2443 2444static int ocfs2_downconvert_lock(struct ocfs2_super *osb, 2445 struct ocfs2_lock_res *lockres, 2446 int new_level, 2447 int lvb) 2448{ 2449 int ret, dlm_flags = LKM_CONVERT; 2450 enum dlm_status status; 2451 2452 mlog_entry_void(); 2453 2454 if (lvb) 2455 dlm_flags |= LKM_VALBLK; 2456 2457 status = dlmlock(osb->dlm, 2458 new_level, 2459 &lockres->l_lksb, 2460 dlm_flags, 2461 lockres->l_name, 2462 OCFS2_LOCK_ID_MAX_LEN - 1, 2463 ocfs2_locking_ast, 2464 lockres, 2465 ocfs2_blocking_ast); 2466 if (status != DLM_NORMAL) { 2467 ocfs2_log_dlm_error("dlmlock", status, lockres); 2468 ret = -EINVAL; 2469 ocfs2_recover_from_dlm_error(lockres, 1); 2470 goto bail; 2471 } 2472 2473 ret = 0; 2474bail: 2475 mlog_exit(ret); 2476 return ret; 2477} 2478 2479/* returns 1 when the caller should unlock and call dlmunlock */ 2480static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb, 2481 struct ocfs2_lock_res *lockres) 2482{ 2483 assert_spin_locked(&lockres->l_lock); 2484 2485 mlog_entry_void(); 2486 mlog(0, "lock %s\n", lockres->l_name); 2487 2488 if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) { 2489 /* If we're already trying to cancel a lock conversion 2490 * then just drop the spinlock and allow the caller to 2491 * requeue this lock. */ 2492 2493 mlog(0, "Lockres %s, skip convert\n", lockres->l_name); 2494 return 0; 2495 } 2496 2497 /* were we in a convert when we got the bast fire? */ 2498 BUG_ON(lockres->l_action != OCFS2_AST_CONVERT && 2499 lockres->l_action != OCFS2_AST_DOWNCONVERT); 2500 /* set things up for the unlockast to know to just 2501 * clear out the ast_action and unset busy, etc. */ 2502 lockres->l_unlock_action = OCFS2_UNLOCK_CANCEL_CONVERT; 2503 2504 mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_BUSY), 2505 "lock %s, invalid flags: 0x%lx\n", 2506 lockres->l_name, lockres->l_flags); 2507 2508 return 1; 2509} 2510 2511static int ocfs2_cancel_convert(struct ocfs2_super *osb, 2512 struct ocfs2_lock_res *lockres) 2513{ 2514 int ret; 2515 enum dlm_status status; 2516 2517 mlog_entry_void(); 2518 mlog(0, "lock %s\n", lockres->l_name); 2519 2520 ret = 0; 2521 status = dlmunlock(osb->dlm, 2522 &lockres->l_lksb, 2523 LKM_CANCEL, 2524 ocfs2_unlock_ast, 2525 lockres); 2526 if (status != DLM_NORMAL) { 2527 ocfs2_log_dlm_error("dlmunlock", status, lockres); 2528 ret = -EINVAL; 2529 ocfs2_recover_from_dlm_error(lockres, 0); 2530 } 2531 2532 mlog(0, "lock %s return from dlmunlock\n", lockres->l_name); 2533 2534 mlog_exit(ret); 2535 return ret; 2536} 2537 2538static int ocfs2_generic_unblock_lock(struct ocfs2_super *osb, 2539 struct ocfs2_lock_res *lockres, 2540 struct ocfs2_unblock_ctl *ctl, 2541 ocfs2_convert_worker_t *worker) 2542{ 2543 unsigned long flags; 2544 int blocking; 2545 int new_level; 2546 int ret = 0; 2547 int set_lvb = 0; 2548 2549 mlog_entry_void(); 2550 2551 spin_lock_irqsave(&lockres->l_lock, flags); 2552 2553 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED)); 2554 2555recheck: 2556 if (lockres->l_flags & OCFS2_LOCK_BUSY) { 2557 ctl->requeue = 1; 2558 ret = ocfs2_prepare_cancel_convert(osb, lockres); 2559 spin_unlock_irqrestore(&lockres->l_lock, flags); 2560 if (ret) { 2561 ret = ocfs2_cancel_convert(osb, lockres); 2562 if (ret < 0) 2563 mlog_errno(ret); 2564 } 2565 goto leave; 2566 } 2567 2568 /* if we're blocking an exclusive and we have *any* holders, 2569 * then requeue. */ 2570 if ((lockres->l_blocking == LKM_EXMODE) 2571 && (lockres->l_ex_holders || lockres->l_ro_holders)) 2572 goto leave_requeue; 2573 2574 /* If it's a PR we're blocking, then only 2575 * requeue if we've got any EX holders */ 2576 if (lockres->l_blocking == LKM_PRMODE && 2577 lockres->l_ex_holders) 2578 goto leave_requeue; 2579 2580 /* 2581 * Can we get a lock in this state if the holder counts are 2582 * zero? The meta data unblock code used to check this. 2583 */ 2584 if ((lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH) 2585 && (lockres->l_flags & OCFS2_LOCK_REFRESHING)) 2586 goto leave_requeue; 2587 2588 new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking); 2589 2590 if (lockres->l_ops->check_downconvert 2591 && !lockres->l_ops->check_downconvert(lockres, new_level)) 2592 goto leave_requeue; 2593 2594 /* If we get here, then we know that there are no more 2595 * incompatible holders (and anyone asking for an incompatible 2596 * lock is blocked). We can now downconvert the lock */ 2597 if (!worker) 2598 goto downconvert; 2599 2600 /* Some lockres types want to do a bit of work before 2601 * downconverting a lock. Allow that here. The worker function 2602 * may sleep, so we save off a copy of what we're blocking as 2603 * it may change while we're not holding the spin lock. */ 2604 blocking = lockres->l_blocking; 2605 spin_unlock_irqrestore(&lockres->l_lock, flags); 2606 2607 ctl->unblock_action = worker(lockres, blocking); 2608 2609 if (ctl->unblock_action == UNBLOCK_STOP_POST) 2610 goto leave; 2611 2612 spin_lock_irqsave(&lockres->l_lock, flags); 2613 if (blocking != lockres->l_blocking) { 2614 /* If this changed underneath us, then we can't drop 2615 * it just yet. */ 2616 goto recheck; 2617 } 2618 2619downconvert: 2620 ctl->requeue = 0; 2621 2622 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) { 2623 if (lockres->l_level == LKM_EXMODE) 2624 set_lvb = 1; 2625 2626 /* 2627 * We only set the lvb if the lock has been fully 2628 * refreshed - otherwise we risk setting stale 2629 * data. Otherwise, there's no need to actually clear 2630 * out the lvb here as it's value is still valid. 2631 */ 2632 if (set_lvb && !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) 2633 lockres->l_ops->set_lvb(lockres); 2634 } 2635 2636 ocfs2_prepare_downconvert(lockres, new_level); 2637 spin_unlock_irqrestore(&lockres->l_lock, flags); 2638 ret = ocfs2_downconvert_lock(osb, lockres, new_level, set_lvb); 2639leave: 2640 mlog_exit(ret); 2641 return ret; 2642 2643leave_requeue: 2644 spin_unlock_irqrestore(&lockres->l_lock, flags); 2645 ctl->requeue = 1; 2646 2647 mlog_exit(0); 2648 return 0; 2649} 2650 2651static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres, 2652 int blocking) 2653{ 2654 struct inode *inode; 2655 struct address_space *mapping; 2656 2657 inode = ocfs2_lock_res_inode(lockres); 2658 mapping = inode->i_mapping; 2659 2660 if (filemap_fdatawrite(mapping)) { 2661 mlog(ML_ERROR, "Could not sync inode %llu for downconvert!", 2662 (unsigned long long)OCFS2_I(inode)->ip_blkno); 2663 } 2664 sync_mapping_buffers(mapping); 2665 if (blocking == LKM_EXMODE) { 2666 truncate_inode_pages(mapping, 0); 2667 unmap_mapping_range(mapping, 0, 0, 0); 2668 } else { 2669 /* We only need to wait on the I/O if we're not also 2670 * truncating pages because truncate_inode_pages waits 2671 * for us above. We don't truncate pages if we're 2672 * blocking anything < EXMODE because we want to keep 2673 * them around in that case. */ 2674 filemap_fdatawait(mapping); 2675 } 2676 2677 return UNBLOCK_CONTINUE; 2678} 2679 2680int ocfs2_unblock_data(struct ocfs2_lock_res *lockres, 2681 struct ocfs2_unblock_ctl *ctl) 2682{ 2683 int status; 2684 struct inode *inode; 2685 struct ocfs2_super *osb; 2686 2687 mlog_entry_void(); 2688 2689 inode = ocfs2_lock_res_inode(lockres); 2690 osb = OCFS2_SB(inode->i_sb); 2691 2692 mlog(0, "unblock inode %llu\n", 2693 (unsigned long long)OCFS2_I(inode)->ip_blkno); 2694 2695 status = ocfs2_generic_unblock_lock(osb, lockres, ctl, 2696 ocfs2_data_convert_worker); 2697 if (status < 0) 2698 mlog_errno(status); 2699 2700 mlog(0, "inode %llu, requeue = %d\n", 2701 (unsigned long long)OCFS2_I(inode)->ip_blkno, ctl->requeue); 2702 2703 mlog_exit(status); 2704 return status; 2705} 2706 2707static int ocfs2_unblock_inode_lock(struct ocfs2_lock_res *lockres, 2708 struct ocfs2_unblock_ctl *ctl) 2709{ 2710 int status; 2711 struct inode *inode; 2712 2713 mlog_entry_void(); 2714 2715 mlog(0, "Unblock lockres %s\n", lockres->l_name); 2716 2717 inode = ocfs2_lock_res_inode(lockres); 2718 2719 status = ocfs2_generic_unblock_lock(OCFS2_SB(inode->i_sb), 2720 lockres, ctl, NULL); 2721 if (status < 0) 2722 mlog_errno(status); 2723 2724 mlog_exit(status); 2725 return status; 2726} 2727 2728static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres, 2729 int new_level) 2730{ 2731 struct inode *inode = ocfs2_lock_res_inode(lockres); 2732 int checkpointed = ocfs2_inode_fully_checkpointed(inode); 2733 2734 BUG_ON(new_level != LKM_NLMODE && new_level != LKM_PRMODE); 2735 BUG_ON(lockres->l_level != LKM_EXMODE && !checkpointed); 2736 2737 if (checkpointed) 2738 return 1; 2739 2740 ocfs2_start_checkpoint(OCFS2_SB(inode->i_sb)); 2741 return 0; 2742} 2743 2744static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres) 2745{ 2746 struct inode *inode = ocfs2_lock_res_inode(lockres); 2747 2748 __ocfs2_stuff_meta_lvb(inode); 2749} 2750 2751static int ocfs2_unblock_meta(struct ocfs2_lock_res *lockres, 2752 struct ocfs2_unblock_ctl *ctl) 2753{ 2754 int status; 2755 struct inode *inode; 2756 2757 mlog_entry_void(); 2758 2759 inode = ocfs2_lock_res_inode(lockres); 2760 2761 mlog(0, "unblock inode %llu\n", 2762 (unsigned long long)OCFS2_I(inode)->ip_blkno); 2763 2764 status = ocfs2_generic_unblock_lock(OCFS2_SB(inode->i_sb), 2765 lockres, ctl, NULL); 2766 if (status < 0) 2767 mlog_errno(status); 2768 2769 mlog(0, "inode %llu, requeue = %d\n", 2770 (unsigned long long)OCFS2_I(inode)->ip_blkno, ctl->requeue); 2771 2772 mlog_exit(status); 2773 return status; 2774} 2775 2776/* 2777 * Does the final reference drop on our dentry lock. Right now this 2778 * happens in the vote thread, but we could choose to simplify the 2779 * dlmglue API and push these off to the ocfs2_wq in the future. 2780 */ 2781static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb, 2782 struct ocfs2_lock_res *lockres) 2783{ 2784 struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres); 2785 ocfs2_dentry_lock_put(osb, dl); 2786} 2787 2788/* 2789 * d_delete() matching dentries before the lock downconvert. 2790 * 2791 * At this point, any process waiting to destroy the 2792 * dentry_lock due to last ref count is stopped by the 2793 * OCFS2_LOCK_QUEUED flag. 2794 * 2795 * We have two potential problems 2796 * 2797 * 1) If we do the last reference drop on our dentry_lock (via dput) 2798 * we'll wind up in ocfs2_release_dentry_lock(), waiting on 2799 * the downconvert to finish. Instead we take an elevated 2800 * reference and push the drop until after we've completed our 2801 * unblock processing. 2802 * 2803 * 2) There might be another process with a final reference, 2804 * waiting on us to finish processing. If this is the case, we 2805 * detect it and exit out - there's no more dentries anyway. 2806 */ 2807static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres, 2808 int blocking) 2809{ 2810 struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres); 2811 struct ocfs2_inode_info *oi = OCFS2_I(dl->dl_inode); 2812 struct dentry *dentry; 2813 unsigned long flags; 2814 int extra_ref = 0; 2815 2816 /* 2817 * This node is blocking another node from getting a read 2818 * lock. This happens when we've renamed within a 2819 * directory. We've forced the other nodes to d_delete(), but 2820 * we never actually dropped our lock because it's still 2821 * valid. The downconvert code will retain a PR for this node, 2822 * so there's no further work to do. 2823 */ 2824 if (blocking == LKM_PRMODE) 2825 return UNBLOCK_CONTINUE; 2826 2827 /* 2828 * Mark this inode as potentially orphaned. The code in 2829 * ocfs2_delete_inode() will figure out whether it actually 2830 * needs to be freed or not. 2831 */ 2832 spin_lock(&oi->ip_lock); 2833 oi->ip_flags |= OCFS2_INODE_MAYBE_ORPHANED; 2834 spin_unlock(&oi->ip_lock); 2835 2836 /* 2837 * Yuck. We need to make sure however that the check of 2838 * OCFS2_LOCK_FREEING and the extra reference are atomic with 2839 * respect to a reference decrement or the setting of that 2840 * flag. 2841 */ 2842 spin_lock_irqsave(&lockres->l_lock, flags); 2843 spin_lock(&dentry_attach_lock); 2844 if (!(lockres->l_flags & OCFS2_LOCK_FREEING) 2845 && dl->dl_count) { 2846 dl->dl_count++; 2847 extra_ref = 1; 2848 } 2849 spin_unlock(&dentry_attach_lock); 2850 spin_unlock_irqrestore(&lockres->l_lock, flags); 2851 2852 mlog(0, "extra_ref = %d\n", extra_ref); 2853 2854 /* 2855 * We have a process waiting on us in ocfs2_dentry_iput(), 2856 * which means we can't have any more outstanding 2857 * aliases. There's no need to do any more work. 2858 */ 2859 if (!extra_ref) 2860 return UNBLOCK_CONTINUE; 2861 2862 spin_lock(&dentry_attach_lock); 2863 while (1) { 2864 dentry = ocfs2_find_local_alias(dl->dl_inode, 2865 dl->dl_parent_blkno, 1); 2866 if (!dentry) 2867 break; 2868 spin_unlock(&dentry_attach_lock); 2869 2870 mlog(0, "d_delete(%.*s);\n", dentry->d_name.len, 2871 dentry->d_name.name); 2872 2873 /* 2874 * The following dcache calls may do an 2875 * iput(). Normally we don't want that from the 2876 * downconverting thread, but in this case it's ok 2877 * because the requesting node already has an 2878 * exclusive lock on the inode, so it can't be queued 2879 * for a downconvert. 2880 */ 2881 d_delete(dentry); 2882 dput(dentry); 2883 2884 spin_lock(&dentry_attach_lock); 2885 } 2886 spin_unlock(&dentry_attach_lock); 2887 2888 /* 2889 * If we are the last holder of this dentry lock, there is no 2890 * reason to downconvert so skip straight to the unlock. 2891 */ 2892 if (dl->dl_count == 1) 2893 return UNBLOCK_STOP_POST; 2894 2895 return UNBLOCK_CONTINUE_POST; 2896} 2897 2898static int ocfs2_unblock_dentry_lock(struct ocfs2_lock_res *lockres, 2899 struct ocfs2_unblock_ctl *ctl) 2900{ 2901 int ret; 2902 struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres); 2903 struct ocfs2_super *osb = OCFS2_SB(dl->dl_inode->i_sb); 2904 2905 mlog(0, "unblock dentry lock: %llu\n", 2906 (unsigned long long)OCFS2_I(dl->dl_inode)->ip_blkno); 2907 2908 ret = ocfs2_generic_unblock_lock(osb, 2909 lockres, 2910 ctl, 2911 ocfs2_dentry_convert_worker); 2912 if (ret < 0) 2913 mlog_errno(ret); 2914 2915 mlog(0, "requeue = %d, post = %d\n", ctl->requeue, ctl->unblock_action); 2916 2917 return ret; 2918} 2919 2920/* Generic unblock function for any lockres whose private data is an 2921 * ocfs2_super pointer. */ 2922static int ocfs2_unblock_osb_lock(struct ocfs2_lock_res *lockres, 2923 struct ocfs2_unblock_ctl *ctl) 2924{ 2925 int status; 2926 struct ocfs2_super *osb; 2927 2928 mlog_entry_void(); 2929 2930 mlog(0, "Unblock lockres %s\n", lockres->l_name); 2931 2932 osb = ocfs2_get_lockres_osb(lockres); 2933 2934 status = ocfs2_generic_unblock_lock(osb, 2935 lockres, 2936 ctl, 2937 NULL); 2938 if (status < 0) 2939 mlog_errno(status); 2940 2941 mlog_exit(status); 2942 return status; 2943} 2944 2945void ocfs2_process_blocked_lock(struct ocfs2_super *osb, 2946 struct ocfs2_lock_res *lockres) 2947{ 2948 int status; 2949 struct ocfs2_unblock_ctl ctl = {0, 0,}; 2950 unsigned long flags; 2951 2952 /* Our reference to the lockres in this function can be 2953 * considered valid until we remove the OCFS2_LOCK_QUEUED 2954 * flag. */ 2955 2956 mlog_entry_void(); 2957 2958 BUG_ON(!lockres); 2959 BUG_ON(!lockres->l_ops); 2960 BUG_ON(!lockres->l_ops->unblock); 2961 2962 mlog(0, "lockres %s blocked.\n", lockres->l_name); 2963 2964 /* Detect whether a lock has been marked as going away while 2965 * the vote thread was processing other things. A lock can 2966 * still be marked with OCFS2_LOCK_FREEING after this check, 2967 * but short circuiting here will still save us some 2968 * performance. */ 2969 spin_lock_irqsave(&lockres->l_lock, flags); 2970 if (lockres->l_flags & OCFS2_LOCK_FREEING) 2971 goto unqueue; 2972 spin_unlock_irqrestore(&lockres->l_lock, flags); 2973 2974 status = lockres->l_ops->unblock(lockres, &ctl); 2975 if (status < 0) 2976 mlog_errno(status); 2977 2978 spin_lock_irqsave(&lockres->l_lock, flags); 2979unqueue: 2980 if (lockres->l_flags & OCFS2_LOCK_FREEING || !ctl.requeue) { 2981 lockres_clear_flags(lockres, OCFS2_LOCK_QUEUED); 2982 } else 2983 ocfs2_schedule_blocked_lock(osb, lockres); 2984 2985 mlog(0, "lockres %s, requeue = %s.\n", lockres->l_name, 2986 ctl.requeue ? "yes" : "no"); 2987 spin_unlock_irqrestore(&lockres->l_lock, flags); 2988 2989 if (ctl.unblock_action != UNBLOCK_CONTINUE 2990 && lockres->l_ops->post_unlock) 2991 lockres->l_ops->post_unlock(osb, lockres); 2992 2993 mlog_exit_void(); 2994} 2995 2996static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb, 2997 struct ocfs2_lock_res *lockres) 2998{ 2999 mlog_entry_void(); 3000 3001 assert_spin_locked(&lockres->l_lock); 3002 3003 if (lockres->l_flags & OCFS2_LOCK_FREEING) { 3004 /* Do not schedule a lock for downconvert when it's on 3005 * the way to destruction - any nodes wanting access 3006 * to the resource will get it soon. */ 3007 mlog(0, "Lockres %s won't be scheduled: flags 0x%lx\n", 3008 lockres->l_name, lockres->l_flags); 3009 return; 3010 } 3011 3012 lockres_or_flags(lockres, OCFS2_LOCK_QUEUED); 3013 3014 spin_lock(&osb->vote_task_lock); 3015 if (list_empty(&lockres->l_blocked_list)) { 3016 list_add_tail(&lockres->l_blocked_list, 3017 &osb->blocked_lock_list); 3018 osb->blocked_lock_count++; 3019 } 3020 spin_unlock(&osb->vote_task_lock); 3021 3022 mlog_exit_void(); 3023} 3024 3025/* This aids in debugging situations where a bad LVB might be involved. */ 3026void ocfs2_dump_meta_lvb_info(u64 level, 3027 const char *function, 3028 unsigned int line, 3029 struct ocfs2_lock_res *lockres) 3030{ 3031 struct ocfs2_meta_lvb *lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb; 3032 3033 mlog(level, "LVB information for %s (called from %s:%u):\n", 3034 lockres->l_name, function, line); 3035 mlog(level, "version: %u, clusters: %u, generation: 0x%x\n", 3036 lvb->lvb_version, be32_to_cpu(lvb->lvb_iclusters), 3037 be32_to_cpu(lvb->lvb_igeneration)); 3038 mlog(level, "size: %llu, uid %u, gid %u, mode 0x%x\n", 3039 (unsigned long long)be64_to_cpu(lvb->lvb_isize), 3040 be32_to_cpu(lvb->lvb_iuid), be32_to_cpu(lvb->lvb_igid), 3041 be16_to_cpu(lvb->lvb_imode)); 3042 mlog(level, "nlink %u, atime_packed 0x%llx, ctime_packed 0x%llx, " 3043 "mtime_packed 0x%llx iattr 0x%x\n", be16_to_cpu(lvb->lvb_inlink), 3044 (long long)be64_to_cpu(lvb->lvb_iatime_packed), 3045 (long long)be64_to_cpu(lvb->lvb_ictime_packed), 3046 (long long)be64_to_cpu(lvb->lvb_imtime_packed), 3047 be32_to_cpu(lvb->lvb_iattr)); 3048} 3049