dlmglue.c revision 7f1a37e31f94b4f1c123d32ce9f69205ab2095bd
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 "file.h" 53#include "heartbeat.h" 54#include "inode.h" 55#include "journal.h" 56#include "slot_map.h" 57#include "super.h" 58#include "uptodate.h" 59#include "vote.h" 60 61#include "buffer_head_io.h" 62 63struct ocfs2_mask_waiter { 64 struct list_head mw_item; 65 int mw_status; 66 struct completion mw_complete; 67 unsigned long mw_mask; 68 unsigned long mw_goal; 69}; 70 71static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres); 72static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres); 73 74/* 75 * Return value from ->downconvert_worker functions. 76 * 77 * These control the precise actions of ocfs2_unblock_lock() 78 * and ocfs2_process_blocked_lock() 79 * 80 */ 81enum ocfs2_unblock_action { 82 UNBLOCK_CONTINUE = 0, /* Continue downconvert */ 83 UNBLOCK_CONTINUE_POST = 1, /* Continue downconvert, fire 84 * ->post_unlock callback */ 85 UNBLOCK_STOP_POST = 2, /* Do not downconvert, fire 86 * ->post_unlock() callback. */ 87}; 88 89struct ocfs2_unblock_ctl { 90 int requeue; 91 enum ocfs2_unblock_action unblock_action; 92}; 93 94static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres, 95 int new_level); 96static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres); 97 98static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres, 99 int blocking); 100 101static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres, 102 int blocking); 103 104static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb, 105 struct ocfs2_lock_res *lockres); 106 107/* 108 * OCFS2 Lock Resource Operations 109 * 110 * These fine tune the behavior of the generic dlmglue locking infrastructure. 111 * 112 * The most basic of lock types can point ->l_priv to their respective 113 * struct ocfs2_super and allow the default actions to manage things. 114 * 115 * Right now, each lock type also needs to implement an init function, 116 * and trivial lock/unlock wrappers. ocfs2_simple_drop_lockres() 117 * should be called when the lock is no longer needed (i.e., object 118 * destruction time). 119 */ 120struct ocfs2_lock_res_ops { 121 /* 122 * Translate an ocfs2_lock_res * into an ocfs2_super *. Define 123 * this callback if ->l_priv is not an ocfs2_super pointer 124 */ 125 struct ocfs2_super * (*get_osb)(struct ocfs2_lock_res *); 126 127 /* 128 * Optionally called in the downconvert (or "vote") thread 129 * after a successful downconvert. The lockres will not be 130 * referenced after this callback is called, so it is safe to 131 * free memory, etc. 132 * 133 * The exact semantics of when this is called are controlled 134 * by ->downconvert_worker() 135 */ 136 void (*post_unlock)(struct ocfs2_super *, struct ocfs2_lock_res *); 137 138 /* 139 * Allow a lock type to add checks to determine whether it is 140 * safe to downconvert a lock. Return 0 to re-queue the 141 * downconvert at a later time, nonzero to continue. 142 * 143 * For most locks, the default checks that there are no 144 * incompatible holders are sufficient. 145 * 146 * Called with the lockres spinlock held. 147 */ 148 int (*check_downconvert)(struct ocfs2_lock_res *, int); 149 150 /* 151 * Allows a lock type to populate the lock value block. This 152 * is called on downconvert, and when we drop a lock. 153 * 154 * Locks that want to use this should set LOCK_TYPE_USES_LVB 155 * in the flags field. 156 * 157 * Called with the lockres spinlock held. 158 */ 159 void (*set_lvb)(struct ocfs2_lock_res *); 160 161 /* 162 * Called from the downconvert thread when it is determined 163 * that a lock will be downconverted. This is called without 164 * any locks held so the function can do work that might 165 * schedule (syncing out data, etc). 166 * 167 * This should return any one of the ocfs2_unblock_action 168 * values, depending on what it wants the thread to do. 169 */ 170 int (*downconvert_worker)(struct ocfs2_lock_res *, int); 171 172 /* 173 * LOCK_TYPE_* flags which describe the specific requirements 174 * of a lock type. Descriptions of each individual flag follow. 175 */ 176 int flags; 177}; 178 179/* 180 * Some locks want to "refresh" potentially stale data when a 181 * meaningful (PRMODE or EXMODE) lock level is first obtained. If this 182 * flag is set, the OCFS2_LOCK_NEEDS_REFRESH flag will be set on the 183 * individual lockres l_flags member from the ast function. It is 184 * expected that the locking wrapper will clear the 185 * OCFS2_LOCK_NEEDS_REFRESH flag when done. 186 */ 187#define LOCK_TYPE_REQUIRES_REFRESH 0x1 188 189/* 190 * Indicate that a lock type makes use of the lock value block. The 191 * ->set_lvb lock type callback must be defined. 192 */ 193#define LOCK_TYPE_USES_LVB 0x2 194 195static struct ocfs2_lock_res_ops ocfs2_inode_rw_lops = { 196 .get_osb = ocfs2_get_inode_osb, 197 .flags = 0, 198}; 199 200static struct ocfs2_lock_res_ops ocfs2_inode_meta_lops = { 201 .get_osb = ocfs2_get_inode_osb, 202 .check_downconvert = ocfs2_check_meta_downconvert, 203 .set_lvb = ocfs2_set_meta_lvb, 204 .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB, 205}; 206 207static struct ocfs2_lock_res_ops ocfs2_inode_data_lops = { 208 .get_osb = ocfs2_get_inode_osb, 209 .downconvert_worker = ocfs2_data_convert_worker, 210 .flags = 0, 211}; 212 213static struct ocfs2_lock_res_ops ocfs2_super_lops = { 214 .flags = LOCK_TYPE_REQUIRES_REFRESH, 215}; 216 217static struct ocfs2_lock_res_ops ocfs2_rename_lops = { 218 .flags = 0, 219}; 220 221static struct ocfs2_lock_res_ops ocfs2_dentry_lops = { 222 .get_osb = ocfs2_get_dentry_osb, 223 .post_unlock = ocfs2_dentry_post_unlock, 224 .downconvert_worker = ocfs2_dentry_convert_worker, 225 .flags = 0, 226}; 227 228static inline int ocfs2_is_inode_lock(struct ocfs2_lock_res *lockres) 229{ 230 return lockres->l_type == OCFS2_LOCK_TYPE_META || 231 lockres->l_type == OCFS2_LOCK_TYPE_DATA || 232 lockres->l_type == OCFS2_LOCK_TYPE_RW; 233} 234 235static inline struct inode *ocfs2_lock_res_inode(struct ocfs2_lock_res *lockres) 236{ 237 BUG_ON(!ocfs2_is_inode_lock(lockres)); 238 239 return (struct inode *) lockres->l_priv; 240} 241 242static inline struct ocfs2_dentry_lock *ocfs2_lock_res_dl(struct ocfs2_lock_res *lockres) 243{ 244 BUG_ON(lockres->l_type != OCFS2_LOCK_TYPE_DENTRY); 245 246 return (struct ocfs2_dentry_lock *)lockres->l_priv; 247} 248 249static inline struct ocfs2_super *ocfs2_get_lockres_osb(struct ocfs2_lock_res *lockres) 250{ 251 if (lockres->l_ops->get_osb) 252 return lockres->l_ops->get_osb(lockres); 253 254 return (struct ocfs2_super *)lockres->l_priv; 255} 256 257static int ocfs2_lock_create(struct ocfs2_super *osb, 258 struct ocfs2_lock_res *lockres, 259 int level, 260 int dlm_flags); 261static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres, 262 int wanted); 263static void ocfs2_cluster_unlock(struct ocfs2_super *osb, 264 struct ocfs2_lock_res *lockres, 265 int level); 266static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres); 267static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres); 268static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres); 269static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres, int level); 270static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb, 271 struct ocfs2_lock_res *lockres); 272static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres, 273 int convert); 274#define ocfs2_log_dlm_error(_func, _stat, _lockres) do { \ 275 mlog(ML_ERROR, "Dlm error \"%s\" while calling %s on " \ 276 "resource %s: %s\n", dlm_errname(_stat), _func, \ 277 _lockres->l_name, dlm_errmsg(_stat)); \ 278} while (0) 279static void ocfs2_vote_on_unlock(struct ocfs2_super *osb, 280 struct ocfs2_lock_res *lockres); 281static int ocfs2_meta_lock_update(struct inode *inode, 282 struct buffer_head **bh); 283static void ocfs2_drop_osb_locks(struct ocfs2_super *osb); 284static inline int ocfs2_highest_compat_lock_level(int level); 285 286static void ocfs2_build_lock_name(enum ocfs2_lock_type type, 287 u64 blkno, 288 u32 generation, 289 char *name) 290{ 291 int len; 292 293 mlog_entry_void(); 294 295 BUG_ON(type >= OCFS2_NUM_LOCK_TYPES); 296 297 len = snprintf(name, OCFS2_LOCK_ID_MAX_LEN, "%c%s%016llx%08x", 298 ocfs2_lock_type_char(type), OCFS2_LOCK_ID_PAD, 299 (long long)blkno, generation); 300 301 BUG_ON(len != (OCFS2_LOCK_ID_MAX_LEN - 1)); 302 303 mlog(0, "built lock resource with name: %s\n", name); 304 305 mlog_exit_void(); 306} 307 308static DEFINE_SPINLOCK(ocfs2_dlm_tracking_lock); 309 310static void ocfs2_add_lockres_tracking(struct ocfs2_lock_res *res, 311 struct ocfs2_dlm_debug *dlm_debug) 312{ 313 mlog(0, "Add tracking for lockres %s\n", res->l_name); 314 315 spin_lock(&ocfs2_dlm_tracking_lock); 316 list_add(&res->l_debug_list, &dlm_debug->d_lockres_tracking); 317 spin_unlock(&ocfs2_dlm_tracking_lock); 318} 319 320static void ocfs2_remove_lockres_tracking(struct ocfs2_lock_res *res) 321{ 322 spin_lock(&ocfs2_dlm_tracking_lock); 323 if (!list_empty(&res->l_debug_list)) 324 list_del_init(&res->l_debug_list); 325 spin_unlock(&ocfs2_dlm_tracking_lock); 326} 327 328static void ocfs2_lock_res_init_common(struct ocfs2_super *osb, 329 struct ocfs2_lock_res *res, 330 enum ocfs2_lock_type type, 331 struct ocfs2_lock_res_ops *ops, 332 void *priv) 333{ 334 res->l_type = type; 335 res->l_ops = ops; 336 res->l_priv = priv; 337 338 res->l_level = LKM_IVMODE; 339 res->l_requested = LKM_IVMODE; 340 res->l_blocking = LKM_IVMODE; 341 res->l_action = OCFS2_AST_INVALID; 342 res->l_unlock_action = OCFS2_UNLOCK_INVALID; 343 344 res->l_flags = OCFS2_LOCK_INITIALIZED; 345 346 ocfs2_add_lockres_tracking(res, osb->osb_dlm_debug); 347} 348 349void ocfs2_lock_res_init_once(struct ocfs2_lock_res *res) 350{ 351 /* This also clears out the lock status block */ 352 memset(res, 0, sizeof(struct ocfs2_lock_res)); 353 spin_lock_init(&res->l_lock); 354 init_waitqueue_head(&res->l_event); 355 INIT_LIST_HEAD(&res->l_blocked_list); 356 INIT_LIST_HEAD(&res->l_mask_waiters); 357} 358 359void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res, 360 enum ocfs2_lock_type type, 361 unsigned int generation, 362 struct inode *inode) 363{ 364 struct ocfs2_lock_res_ops *ops; 365 366 switch(type) { 367 case OCFS2_LOCK_TYPE_RW: 368 ops = &ocfs2_inode_rw_lops; 369 break; 370 case OCFS2_LOCK_TYPE_META: 371 ops = &ocfs2_inode_meta_lops; 372 break; 373 case OCFS2_LOCK_TYPE_DATA: 374 ops = &ocfs2_inode_data_lops; 375 break; 376 default: 377 mlog_bug_on_msg(1, "type: %d\n", type); 378 ops = NULL; /* thanks, gcc */ 379 break; 380 }; 381 382 ocfs2_build_lock_name(type, OCFS2_I(inode)->ip_blkno, 383 generation, res->l_name); 384 ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), res, type, ops, inode); 385} 386 387static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres) 388{ 389 struct inode *inode = ocfs2_lock_res_inode(lockres); 390 391 return OCFS2_SB(inode->i_sb); 392} 393 394static __u64 ocfs2_get_dentry_lock_ino(struct ocfs2_lock_res *lockres) 395{ 396 __be64 inode_blkno_be; 397 398 memcpy(&inode_blkno_be, &lockres->l_name[OCFS2_DENTRY_LOCK_INO_START], 399 sizeof(__be64)); 400 401 return be64_to_cpu(inode_blkno_be); 402} 403 404static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres) 405{ 406 struct ocfs2_dentry_lock *dl = lockres->l_priv; 407 408 return OCFS2_SB(dl->dl_inode->i_sb); 409} 410 411void ocfs2_dentry_lock_res_init(struct ocfs2_dentry_lock *dl, 412 u64 parent, struct inode *inode) 413{ 414 int len; 415 u64 inode_blkno = OCFS2_I(inode)->ip_blkno; 416 __be64 inode_blkno_be = cpu_to_be64(inode_blkno); 417 struct ocfs2_lock_res *lockres = &dl->dl_lockres; 418 419 ocfs2_lock_res_init_once(lockres); 420 421 /* 422 * Unfortunately, the standard lock naming scheme won't work 423 * here because we have two 16 byte values to use. Instead, 424 * we'll stuff the inode number as a binary value. We still 425 * want error prints to show something without garbling the 426 * display, so drop a null byte in there before the inode 427 * number. A future version of OCFS2 will likely use all 428 * binary lock names. The stringified names have been a 429 * tremendous aid in debugging, but now that the debugfs 430 * interface exists, we can mangle things there if need be. 431 * 432 * NOTE: We also drop the standard "pad" value (the total lock 433 * name size stays the same though - the last part is all 434 * zeros due to the memset in ocfs2_lock_res_init_once() 435 */ 436 len = snprintf(lockres->l_name, OCFS2_DENTRY_LOCK_INO_START, 437 "%c%016llx", 438 ocfs2_lock_type_char(OCFS2_LOCK_TYPE_DENTRY), 439 (long long)parent); 440 441 BUG_ON(len != (OCFS2_DENTRY_LOCK_INO_START - 1)); 442 443 memcpy(&lockres->l_name[OCFS2_DENTRY_LOCK_INO_START], &inode_blkno_be, 444 sizeof(__be64)); 445 446 ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), lockres, 447 OCFS2_LOCK_TYPE_DENTRY, &ocfs2_dentry_lops, 448 dl); 449} 450 451static void ocfs2_super_lock_res_init(struct ocfs2_lock_res *res, 452 struct ocfs2_super *osb) 453{ 454 /* Superblock lockres doesn't come from a slab so we call init 455 * once on it manually. */ 456 ocfs2_lock_res_init_once(res); 457 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_SUPER, OCFS2_SUPER_BLOCK_BLKNO, 458 0, res->l_name); 459 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_SUPER, 460 &ocfs2_super_lops, osb); 461} 462 463static void ocfs2_rename_lock_res_init(struct ocfs2_lock_res *res, 464 struct ocfs2_super *osb) 465{ 466 /* Rename lockres doesn't come from a slab so we call init 467 * once on it manually. */ 468 ocfs2_lock_res_init_once(res); 469 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_RENAME, 0, 0, res->l_name); 470 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_RENAME, 471 &ocfs2_rename_lops, osb); 472} 473 474void ocfs2_lock_res_free(struct ocfs2_lock_res *res) 475{ 476 mlog_entry_void(); 477 478 if (!(res->l_flags & OCFS2_LOCK_INITIALIZED)) 479 return; 480 481 ocfs2_remove_lockres_tracking(res); 482 483 mlog_bug_on_msg(!list_empty(&res->l_blocked_list), 484 "Lockres %s is on the blocked list\n", 485 res->l_name); 486 mlog_bug_on_msg(!list_empty(&res->l_mask_waiters), 487 "Lockres %s has mask waiters pending\n", 488 res->l_name); 489 mlog_bug_on_msg(spin_is_locked(&res->l_lock), 490 "Lockres %s is locked\n", 491 res->l_name); 492 mlog_bug_on_msg(res->l_ro_holders, 493 "Lockres %s has %u ro holders\n", 494 res->l_name, res->l_ro_holders); 495 mlog_bug_on_msg(res->l_ex_holders, 496 "Lockres %s has %u ex holders\n", 497 res->l_name, res->l_ex_holders); 498 499 /* Need to clear out the lock status block for the dlm */ 500 memset(&res->l_lksb, 0, sizeof(res->l_lksb)); 501 502 res->l_flags = 0UL; 503 mlog_exit_void(); 504} 505 506static inline void ocfs2_inc_holders(struct ocfs2_lock_res *lockres, 507 int level) 508{ 509 mlog_entry_void(); 510 511 BUG_ON(!lockres); 512 513 switch(level) { 514 case LKM_EXMODE: 515 lockres->l_ex_holders++; 516 break; 517 case LKM_PRMODE: 518 lockres->l_ro_holders++; 519 break; 520 default: 521 BUG(); 522 } 523 524 mlog_exit_void(); 525} 526 527static inline void ocfs2_dec_holders(struct ocfs2_lock_res *lockres, 528 int level) 529{ 530 mlog_entry_void(); 531 532 BUG_ON(!lockres); 533 534 switch(level) { 535 case LKM_EXMODE: 536 BUG_ON(!lockres->l_ex_holders); 537 lockres->l_ex_holders--; 538 break; 539 case LKM_PRMODE: 540 BUG_ON(!lockres->l_ro_holders); 541 lockres->l_ro_holders--; 542 break; 543 default: 544 BUG(); 545 } 546 mlog_exit_void(); 547} 548 549/* WARNING: This function lives in a world where the only three lock 550 * levels are EX, PR, and NL. It *will* have to be adjusted when more 551 * lock types are added. */ 552static inline int ocfs2_highest_compat_lock_level(int level) 553{ 554 int new_level = LKM_EXMODE; 555 556 if (level == LKM_EXMODE) 557 new_level = LKM_NLMODE; 558 else if (level == LKM_PRMODE) 559 new_level = LKM_PRMODE; 560 return new_level; 561} 562 563static void lockres_set_flags(struct ocfs2_lock_res *lockres, 564 unsigned long newflags) 565{ 566 struct list_head *pos, *tmp; 567 struct ocfs2_mask_waiter *mw; 568 569 assert_spin_locked(&lockres->l_lock); 570 571 lockres->l_flags = newflags; 572 573 list_for_each_safe(pos, tmp, &lockres->l_mask_waiters) { 574 mw = list_entry(pos, struct ocfs2_mask_waiter, mw_item); 575 if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal) 576 continue; 577 578 list_del_init(&mw->mw_item); 579 mw->mw_status = 0; 580 complete(&mw->mw_complete); 581 } 582} 583static void lockres_or_flags(struct ocfs2_lock_res *lockres, unsigned long or) 584{ 585 lockres_set_flags(lockres, lockres->l_flags | or); 586} 587static void lockres_clear_flags(struct ocfs2_lock_res *lockres, 588 unsigned long clear) 589{ 590 lockres_set_flags(lockres, lockres->l_flags & ~clear); 591} 592 593static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres) 594{ 595 mlog_entry_void(); 596 597 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY)); 598 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED)); 599 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED)); 600 BUG_ON(lockres->l_blocking <= LKM_NLMODE); 601 602 lockres->l_level = lockres->l_requested; 603 if (lockres->l_level <= 604 ocfs2_highest_compat_lock_level(lockres->l_blocking)) { 605 lockres->l_blocking = LKM_NLMODE; 606 lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED); 607 } 608 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); 609 610 mlog_exit_void(); 611} 612 613static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres) 614{ 615 mlog_entry_void(); 616 617 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY)); 618 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED)); 619 620 /* Convert from RO to EX doesn't really need anything as our 621 * information is already up to data. Convert from NL to 622 * *anything* however should mark ourselves as needing an 623 * update */ 624 if (lockres->l_level == LKM_NLMODE && 625 lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH) 626 lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH); 627 628 lockres->l_level = lockres->l_requested; 629 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); 630 631 mlog_exit_void(); 632} 633 634static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres) 635{ 636 mlog_entry_void(); 637 638 BUG_ON((!lockres->l_flags & OCFS2_LOCK_BUSY)); 639 BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED); 640 641 if (lockres->l_requested > LKM_NLMODE && 642 !(lockres->l_flags & OCFS2_LOCK_LOCAL) && 643 lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH) 644 lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH); 645 646 lockres->l_level = lockres->l_requested; 647 lockres_or_flags(lockres, OCFS2_LOCK_ATTACHED); 648 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); 649 650 mlog_exit_void(); 651} 652 653static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres, 654 int level) 655{ 656 int needs_downconvert = 0; 657 mlog_entry_void(); 658 659 assert_spin_locked(&lockres->l_lock); 660 661 lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED); 662 663 if (level > lockres->l_blocking) { 664 /* only schedule a downconvert if we haven't already scheduled 665 * one that goes low enough to satisfy the level we're 666 * blocking. this also catches the case where we get 667 * duplicate BASTs */ 668 if (ocfs2_highest_compat_lock_level(level) < 669 ocfs2_highest_compat_lock_level(lockres->l_blocking)) 670 needs_downconvert = 1; 671 672 lockres->l_blocking = level; 673 } 674 675 mlog_exit(needs_downconvert); 676 return needs_downconvert; 677} 678 679static void ocfs2_blocking_ast(void *opaque, int level) 680{ 681 struct ocfs2_lock_res *lockres = opaque; 682 struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres); 683 int needs_downconvert; 684 unsigned long flags; 685 686 BUG_ON(level <= LKM_NLMODE); 687 688 mlog(0, "BAST fired for lockres %s, blocking %d, level %d type %s\n", 689 lockres->l_name, level, lockres->l_level, 690 ocfs2_lock_type_string(lockres->l_type)); 691 692 spin_lock_irqsave(&lockres->l_lock, flags); 693 needs_downconvert = ocfs2_generic_handle_bast(lockres, level); 694 if (needs_downconvert) 695 ocfs2_schedule_blocked_lock(osb, lockres); 696 spin_unlock_irqrestore(&lockres->l_lock, flags); 697 698 wake_up(&lockres->l_event); 699 700 ocfs2_kick_vote_thread(osb); 701} 702 703static void ocfs2_locking_ast(void *opaque) 704{ 705 struct ocfs2_lock_res *lockres = opaque; 706 struct dlm_lockstatus *lksb = &lockres->l_lksb; 707 unsigned long flags; 708 709 spin_lock_irqsave(&lockres->l_lock, flags); 710 711 if (lksb->status != DLM_NORMAL) { 712 mlog(ML_ERROR, "lockres %s: lksb status value of %u!\n", 713 lockres->l_name, lksb->status); 714 spin_unlock_irqrestore(&lockres->l_lock, flags); 715 return; 716 } 717 718 switch(lockres->l_action) { 719 case OCFS2_AST_ATTACH: 720 ocfs2_generic_handle_attach_action(lockres); 721 lockres_clear_flags(lockres, OCFS2_LOCK_LOCAL); 722 break; 723 case OCFS2_AST_CONVERT: 724 ocfs2_generic_handle_convert_action(lockres); 725 break; 726 case OCFS2_AST_DOWNCONVERT: 727 ocfs2_generic_handle_downconvert_action(lockres); 728 break; 729 default: 730 mlog(ML_ERROR, "lockres %s: ast fired with invalid action: %u " 731 "lockres flags = 0x%lx, unlock action: %u\n", 732 lockres->l_name, lockres->l_action, lockres->l_flags, 733 lockres->l_unlock_action); 734 BUG(); 735 } 736 737 /* set it to something invalid so if we get called again we 738 * can catch it. */ 739 lockres->l_action = OCFS2_AST_INVALID; 740 741 wake_up(&lockres->l_event); 742 spin_unlock_irqrestore(&lockres->l_lock, flags); 743} 744 745static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres, 746 int convert) 747{ 748 unsigned long flags; 749 750 mlog_entry_void(); 751 spin_lock_irqsave(&lockres->l_lock, flags); 752 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); 753 if (convert) 754 lockres->l_action = OCFS2_AST_INVALID; 755 else 756 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID; 757 spin_unlock_irqrestore(&lockres->l_lock, flags); 758 759 wake_up(&lockres->l_event); 760 mlog_exit_void(); 761} 762 763/* Note: If we detect another process working on the lock (i.e., 764 * OCFS2_LOCK_BUSY), we'll bail out returning 0. It's up to the caller 765 * to do the right thing in that case. 766 */ 767static int ocfs2_lock_create(struct ocfs2_super *osb, 768 struct ocfs2_lock_res *lockres, 769 int level, 770 int dlm_flags) 771{ 772 int ret = 0; 773 enum dlm_status status; 774 unsigned long flags; 775 776 mlog_entry_void(); 777 778 mlog(0, "lock %s, level = %d, flags = %d\n", lockres->l_name, level, 779 dlm_flags); 780 781 spin_lock_irqsave(&lockres->l_lock, flags); 782 if ((lockres->l_flags & OCFS2_LOCK_ATTACHED) || 783 (lockres->l_flags & OCFS2_LOCK_BUSY)) { 784 spin_unlock_irqrestore(&lockres->l_lock, flags); 785 goto bail; 786 } 787 788 lockres->l_action = OCFS2_AST_ATTACH; 789 lockres->l_requested = level; 790 lockres_or_flags(lockres, OCFS2_LOCK_BUSY); 791 spin_unlock_irqrestore(&lockres->l_lock, flags); 792 793 status = dlmlock(osb->dlm, 794 level, 795 &lockres->l_lksb, 796 dlm_flags, 797 lockres->l_name, 798 OCFS2_LOCK_ID_MAX_LEN - 1, 799 ocfs2_locking_ast, 800 lockres, 801 ocfs2_blocking_ast); 802 if (status != DLM_NORMAL) { 803 ocfs2_log_dlm_error("dlmlock", status, lockres); 804 ret = -EINVAL; 805 ocfs2_recover_from_dlm_error(lockres, 1); 806 } 807 808 mlog(0, "lock %s, successfull return from dlmlock\n", lockres->l_name); 809 810bail: 811 mlog_exit(ret); 812 return ret; 813} 814 815static inline int ocfs2_check_wait_flag(struct ocfs2_lock_res *lockres, 816 int flag) 817{ 818 unsigned long flags; 819 int ret; 820 821 spin_lock_irqsave(&lockres->l_lock, flags); 822 ret = lockres->l_flags & flag; 823 spin_unlock_irqrestore(&lockres->l_lock, flags); 824 825 return ret; 826} 827 828static inline void ocfs2_wait_on_busy_lock(struct ocfs2_lock_res *lockres) 829 830{ 831 wait_event(lockres->l_event, 832 !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_BUSY)); 833} 834 835static inline void ocfs2_wait_on_refreshing_lock(struct ocfs2_lock_res *lockres) 836 837{ 838 wait_event(lockres->l_event, 839 !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_REFRESHING)); 840} 841 842/* predict what lock level we'll be dropping down to on behalf 843 * of another node, and return true if the currently wanted 844 * level will be compatible with it. */ 845static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres, 846 int wanted) 847{ 848 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED)); 849 850 return wanted <= ocfs2_highest_compat_lock_level(lockres->l_blocking); 851} 852 853static void ocfs2_init_mask_waiter(struct ocfs2_mask_waiter *mw) 854{ 855 INIT_LIST_HEAD(&mw->mw_item); 856 init_completion(&mw->mw_complete); 857} 858 859static int ocfs2_wait_for_mask(struct ocfs2_mask_waiter *mw) 860{ 861 wait_for_completion(&mw->mw_complete); 862 /* Re-arm the completion in case we want to wait on it again */ 863 INIT_COMPLETION(mw->mw_complete); 864 return mw->mw_status; 865} 866 867static void lockres_add_mask_waiter(struct ocfs2_lock_res *lockres, 868 struct ocfs2_mask_waiter *mw, 869 unsigned long mask, 870 unsigned long goal) 871{ 872 BUG_ON(!list_empty(&mw->mw_item)); 873 874 assert_spin_locked(&lockres->l_lock); 875 876 list_add_tail(&mw->mw_item, &lockres->l_mask_waiters); 877 mw->mw_mask = mask; 878 mw->mw_goal = goal; 879} 880 881/* returns 0 if the mw that was removed was already satisfied, -EBUSY 882 * if the mask still hadn't reached its goal */ 883static int lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres, 884 struct ocfs2_mask_waiter *mw) 885{ 886 unsigned long flags; 887 int ret = 0; 888 889 spin_lock_irqsave(&lockres->l_lock, flags); 890 if (!list_empty(&mw->mw_item)) { 891 if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal) 892 ret = -EBUSY; 893 894 list_del_init(&mw->mw_item); 895 init_completion(&mw->mw_complete); 896 } 897 spin_unlock_irqrestore(&lockres->l_lock, flags); 898 899 return ret; 900 901} 902 903static int ocfs2_cluster_lock(struct ocfs2_super *osb, 904 struct ocfs2_lock_res *lockres, 905 int level, 906 int lkm_flags, 907 int arg_flags) 908{ 909 struct ocfs2_mask_waiter mw; 910 enum dlm_status status; 911 int wait, catch_signals = !(osb->s_mount_opt & OCFS2_MOUNT_NOINTR); 912 int ret = 0; /* gcc doesn't realize wait = 1 guarantees ret is set */ 913 unsigned long flags; 914 915 mlog_entry_void(); 916 917 ocfs2_init_mask_waiter(&mw); 918 919 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) 920 lkm_flags |= LKM_VALBLK; 921 922again: 923 wait = 0; 924 925 if (catch_signals && signal_pending(current)) { 926 ret = -ERESTARTSYS; 927 goto out; 928 } 929 930 spin_lock_irqsave(&lockres->l_lock, flags); 931 932 mlog_bug_on_msg(lockres->l_flags & OCFS2_LOCK_FREEING, 933 "Cluster lock called on freeing lockres %s! flags " 934 "0x%lx\n", lockres->l_name, lockres->l_flags); 935 936 /* We only compare against the currently granted level 937 * here. If the lock is blocked waiting on a downconvert, 938 * we'll get caught below. */ 939 if (lockres->l_flags & OCFS2_LOCK_BUSY && 940 level > lockres->l_level) { 941 /* is someone sitting in dlm_lock? If so, wait on 942 * them. */ 943 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0); 944 wait = 1; 945 goto unlock; 946 } 947 948 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) { 949 /* lock has not been created yet. */ 950 spin_unlock_irqrestore(&lockres->l_lock, flags); 951 952 ret = ocfs2_lock_create(osb, lockres, LKM_NLMODE, 0); 953 if (ret < 0) { 954 mlog_errno(ret); 955 goto out; 956 } 957 goto again; 958 } 959 960 if (lockres->l_flags & OCFS2_LOCK_BLOCKED && 961 !ocfs2_may_continue_on_blocked_lock(lockres, level)) { 962 /* is the lock is currently blocked on behalf of 963 * another node */ 964 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BLOCKED, 0); 965 wait = 1; 966 goto unlock; 967 } 968 969 if (level > lockres->l_level) { 970 if (lockres->l_action != OCFS2_AST_INVALID) 971 mlog(ML_ERROR, "lockres %s has action %u pending\n", 972 lockres->l_name, lockres->l_action); 973 974 lockres->l_action = OCFS2_AST_CONVERT; 975 lockres->l_requested = level; 976 lockres_or_flags(lockres, OCFS2_LOCK_BUSY); 977 spin_unlock_irqrestore(&lockres->l_lock, flags); 978 979 BUG_ON(level == LKM_IVMODE); 980 BUG_ON(level == LKM_NLMODE); 981 982 mlog(0, "lock %s, convert from %d to level = %d\n", 983 lockres->l_name, lockres->l_level, level); 984 985 /* call dlm_lock to upgrade lock now */ 986 status = dlmlock(osb->dlm, 987 level, 988 &lockres->l_lksb, 989 lkm_flags|LKM_CONVERT, 990 lockres->l_name, 991 OCFS2_LOCK_ID_MAX_LEN - 1, 992 ocfs2_locking_ast, 993 lockres, 994 ocfs2_blocking_ast); 995 if (status != DLM_NORMAL) { 996 if ((lkm_flags & LKM_NOQUEUE) && 997 (status == DLM_NOTQUEUED)) 998 ret = -EAGAIN; 999 else { 1000 ocfs2_log_dlm_error("dlmlock", status, 1001 lockres); 1002 ret = -EINVAL; 1003 } 1004 ocfs2_recover_from_dlm_error(lockres, 1); 1005 goto out; 1006 } 1007 1008 mlog(0, "lock %s, successfull return from dlmlock\n", 1009 lockres->l_name); 1010 1011 /* At this point we've gone inside the dlm and need to 1012 * complete our work regardless. */ 1013 catch_signals = 0; 1014 1015 /* wait for busy to clear and carry on */ 1016 goto again; 1017 } 1018 1019 /* Ok, if we get here then we're good to go. */ 1020 ocfs2_inc_holders(lockres, level); 1021 1022 ret = 0; 1023unlock: 1024 spin_unlock_irqrestore(&lockres->l_lock, flags); 1025out: 1026 /* 1027 * This is helping work around a lock inversion between the page lock 1028 * and dlm locks. One path holds the page lock while calling aops 1029 * which block acquiring dlm locks. The voting thread holds dlm 1030 * locks while acquiring page locks while down converting data locks. 1031 * This block is helping an aop path notice the inversion and back 1032 * off to unlock its page lock before trying the dlm lock again. 1033 */ 1034 if (wait && arg_flags & OCFS2_LOCK_NONBLOCK && 1035 mw.mw_mask & (OCFS2_LOCK_BUSY|OCFS2_LOCK_BLOCKED)) { 1036 wait = 0; 1037 if (lockres_remove_mask_waiter(lockres, &mw)) 1038 ret = -EAGAIN; 1039 else 1040 goto again; 1041 } 1042 if (wait) { 1043 ret = ocfs2_wait_for_mask(&mw); 1044 if (ret == 0) 1045 goto again; 1046 mlog_errno(ret); 1047 } 1048 1049 mlog_exit(ret); 1050 return ret; 1051} 1052 1053static void ocfs2_cluster_unlock(struct ocfs2_super *osb, 1054 struct ocfs2_lock_res *lockres, 1055 int level) 1056{ 1057 unsigned long flags; 1058 1059 mlog_entry_void(); 1060 spin_lock_irqsave(&lockres->l_lock, flags); 1061 ocfs2_dec_holders(lockres, level); 1062 ocfs2_vote_on_unlock(osb, lockres); 1063 spin_unlock_irqrestore(&lockres->l_lock, flags); 1064 mlog_exit_void(); 1065} 1066 1067static int ocfs2_create_new_lock(struct ocfs2_super *osb, 1068 struct ocfs2_lock_res *lockres, 1069 int ex, 1070 int local) 1071{ 1072 int level = ex ? LKM_EXMODE : LKM_PRMODE; 1073 unsigned long flags; 1074 int lkm_flags = local ? LKM_LOCAL : 0; 1075 1076 spin_lock_irqsave(&lockres->l_lock, flags); 1077 BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED); 1078 lockres_or_flags(lockres, OCFS2_LOCK_LOCAL); 1079 spin_unlock_irqrestore(&lockres->l_lock, flags); 1080 1081 return ocfs2_lock_create(osb, lockres, level, lkm_flags); 1082} 1083 1084/* Grants us an EX lock on the data and metadata resources, skipping 1085 * the normal cluster directory lookup. Use this ONLY on newly created 1086 * inodes which other nodes can't possibly see, and which haven't been 1087 * hashed in the inode hash yet. This can give us a good performance 1088 * increase as it'll skip the network broadcast normally associated 1089 * with creating a new lock resource. */ 1090int ocfs2_create_new_inode_locks(struct inode *inode) 1091{ 1092 int ret; 1093 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1094 1095 BUG_ON(!inode); 1096 BUG_ON(!ocfs2_inode_is_new(inode)); 1097 1098 mlog_entry_void(); 1099 1100 mlog(0, "Inode %llu\n", (unsigned long long)OCFS2_I(inode)->ip_blkno); 1101 1102 /* NOTE: That we don't increment any of the holder counts, nor 1103 * do we add anything to a journal handle. Since this is 1104 * supposed to be a new inode which the cluster doesn't know 1105 * about yet, there is no need to. As far as the LVB handling 1106 * is concerned, this is basically like acquiring an EX lock 1107 * on a resource which has an invalid one -- we'll set it 1108 * valid when we release the EX. */ 1109 1110 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_rw_lockres, 1, 1); 1111 if (ret) { 1112 mlog_errno(ret); 1113 goto bail; 1114 } 1115 1116 /* 1117 * We don't want to use LKM_LOCAL on a meta data lock as they 1118 * don't use a generation in their lock names. 1119 */ 1120 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_meta_lockres, 1, 0); 1121 if (ret) { 1122 mlog_errno(ret); 1123 goto bail; 1124 } 1125 1126 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_data_lockres, 1, 1); 1127 if (ret) { 1128 mlog_errno(ret); 1129 goto bail; 1130 } 1131 1132bail: 1133 mlog_exit(ret); 1134 return ret; 1135} 1136 1137int ocfs2_rw_lock(struct inode *inode, int write) 1138{ 1139 int status, level; 1140 struct ocfs2_lock_res *lockres; 1141 1142 BUG_ON(!inode); 1143 1144 mlog_entry_void(); 1145 1146 mlog(0, "inode %llu take %s RW lock\n", 1147 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1148 write ? "EXMODE" : "PRMODE"); 1149 1150 lockres = &OCFS2_I(inode)->ip_rw_lockres; 1151 1152 level = write ? LKM_EXMODE : LKM_PRMODE; 1153 1154 status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres, level, 0, 1155 0); 1156 if (status < 0) 1157 mlog_errno(status); 1158 1159 mlog_exit(status); 1160 return status; 1161} 1162 1163void ocfs2_rw_unlock(struct inode *inode, int write) 1164{ 1165 int level = write ? LKM_EXMODE : LKM_PRMODE; 1166 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_rw_lockres; 1167 1168 mlog_entry_void(); 1169 1170 mlog(0, "inode %llu drop %s RW lock\n", 1171 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1172 write ? "EXMODE" : "PRMODE"); 1173 1174 ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level); 1175 1176 mlog_exit_void(); 1177} 1178 1179int ocfs2_data_lock_full(struct inode *inode, 1180 int write, 1181 int arg_flags) 1182{ 1183 int status = 0, level; 1184 struct ocfs2_lock_res *lockres; 1185 1186 BUG_ON(!inode); 1187 1188 mlog_entry_void(); 1189 1190 mlog(0, "inode %llu take %s DATA lock\n", 1191 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1192 write ? "EXMODE" : "PRMODE"); 1193 1194 /* We'll allow faking a readonly data lock for 1195 * rodevices. */ 1196 if (ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb))) { 1197 if (write) { 1198 status = -EROFS; 1199 mlog_errno(status); 1200 } 1201 goto out; 1202 } 1203 1204 lockres = &OCFS2_I(inode)->ip_data_lockres; 1205 1206 level = write ? LKM_EXMODE : LKM_PRMODE; 1207 1208 status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres, level, 1209 0, arg_flags); 1210 if (status < 0 && status != -EAGAIN) 1211 mlog_errno(status); 1212 1213out: 1214 mlog_exit(status); 1215 return status; 1216} 1217 1218/* see ocfs2_meta_lock_with_page() */ 1219int ocfs2_data_lock_with_page(struct inode *inode, 1220 int write, 1221 struct page *page) 1222{ 1223 int ret; 1224 1225 ret = ocfs2_data_lock_full(inode, write, OCFS2_LOCK_NONBLOCK); 1226 if (ret == -EAGAIN) { 1227 unlock_page(page); 1228 if (ocfs2_data_lock(inode, write) == 0) 1229 ocfs2_data_unlock(inode, write); 1230 ret = AOP_TRUNCATED_PAGE; 1231 } 1232 1233 return ret; 1234} 1235 1236static void ocfs2_vote_on_unlock(struct ocfs2_super *osb, 1237 struct ocfs2_lock_res *lockres) 1238{ 1239 int kick = 0; 1240 1241 mlog_entry_void(); 1242 1243 /* If we know that another node is waiting on our lock, kick 1244 * the vote thread * pre-emptively when we reach a release 1245 * condition. */ 1246 if (lockres->l_flags & OCFS2_LOCK_BLOCKED) { 1247 switch(lockres->l_blocking) { 1248 case LKM_EXMODE: 1249 if (!lockres->l_ex_holders && !lockres->l_ro_holders) 1250 kick = 1; 1251 break; 1252 case LKM_PRMODE: 1253 if (!lockres->l_ex_holders) 1254 kick = 1; 1255 break; 1256 default: 1257 BUG(); 1258 } 1259 } 1260 1261 if (kick) 1262 ocfs2_kick_vote_thread(osb); 1263 1264 mlog_exit_void(); 1265} 1266 1267void ocfs2_data_unlock(struct inode *inode, 1268 int write) 1269{ 1270 int level = write ? LKM_EXMODE : LKM_PRMODE; 1271 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_data_lockres; 1272 1273 mlog_entry_void(); 1274 1275 mlog(0, "inode %llu drop %s DATA lock\n", 1276 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1277 write ? "EXMODE" : "PRMODE"); 1278 1279 if (!ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb))) 1280 ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level); 1281 1282 mlog_exit_void(); 1283} 1284 1285#define OCFS2_SEC_BITS 34 1286#define OCFS2_SEC_SHIFT (64 - 34) 1287#define OCFS2_NSEC_MASK ((1ULL << OCFS2_SEC_SHIFT) - 1) 1288 1289/* LVB only has room for 64 bits of time here so we pack it for 1290 * now. */ 1291static u64 ocfs2_pack_timespec(struct timespec *spec) 1292{ 1293 u64 res; 1294 u64 sec = spec->tv_sec; 1295 u32 nsec = spec->tv_nsec; 1296 1297 res = (sec << OCFS2_SEC_SHIFT) | (nsec & OCFS2_NSEC_MASK); 1298 1299 return res; 1300} 1301 1302/* Call this with the lockres locked. I am reasonably sure we don't 1303 * need ip_lock in this function as anyone who would be changing those 1304 * values is supposed to be blocked in ocfs2_meta_lock right now. */ 1305static void __ocfs2_stuff_meta_lvb(struct inode *inode) 1306{ 1307 struct ocfs2_inode_info *oi = OCFS2_I(inode); 1308 struct ocfs2_lock_res *lockres = &oi->ip_meta_lockres; 1309 struct ocfs2_meta_lvb *lvb; 1310 1311 mlog_entry_void(); 1312 1313 lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb; 1314 1315 /* 1316 * Invalidate the LVB of a deleted inode - this way other 1317 * nodes are forced to go to disk and discover the new inode 1318 * status. 1319 */ 1320 if (oi->ip_flags & OCFS2_INODE_DELETED) { 1321 lvb->lvb_version = 0; 1322 goto out; 1323 } 1324 1325 lvb->lvb_version = OCFS2_LVB_VERSION; 1326 lvb->lvb_isize = cpu_to_be64(i_size_read(inode)); 1327 lvb->lvb_iclusters = cpu_to_be32(oi->ip_clusters); 1328 lvb->lvb_iuid = cpu_to_be32(inode->i_uid); 1329 lvb->lvb_igid = cpu_to_be32(inode->i_gid); 1330 lvb->lvb_imode = cpu_to_be16(inode->i_mode); 1331 lvb->lvb_inlink = cpu_to_be16(inode->i_nlink); 1332 lvb->lvb_iatime_packed = 1333 cpu_to_be64(ocfs2_pack_timespec(&inode->i_atime)); 1334 lvb->lvb_ictime_packed = 1335 cpu_to_be64(ocfs2_pack_timespec(&inode->i_ctime)); 1336 lvb->lvb_imtime_packed = 1337 cpu_to_be64(ocfs2_pack_timespec(&inode->i_mtime)); 1338 lvb->lvb_iattr = cpu_to_be32(oi->ip_attr); 1339 lvb->lvb_igeneration = cpu_to_be32(inode->i_generation); 1340 1341out: 1342 mlog_meta_lvb(0, lockres); 1343 1344 mlog_exit_void(); 1345} 1346 1347static void ocfs2_unpack_timespec(struct timespec *spec, 1348 u64 packed_time) 1349{ 1350 spec->tv_sec = packed_time >> OCFS2_SEC_SHIFT; 1351 spec->tv_nsec = packed_time & OCFS2_NSEC_MASK; 1352} 1353 1354static void ocfs2_refresh_inode_from_lvb(struct inode *inode) 1355{ 1356 struct ocfs2_inode_info *oi = OCFS2_I(inode); 1357 struct ocfs2_lock_res *lockres = &oi->ip_meta_lockres; 1358 struct ocfs2_meta_lvb *lvb; 1359 1360 mlog_entry_void(); 1361 1362 mlog_meta_lvb(0, lockres); 1363 1364 lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb; 1365 1366 /* We're safe here without the lockres lock... */ 1367 spin_lock(&oi->ip_lock); 1368 oi->ip_clusters = be32_to_cpu(lvb->lvb_iclusters); 1369 i_size_write(inode, be64_to_cpu(lvb->lvb_isize)); 1370 1371 oi->ip_attr = be32_to_cpu(lvb->lvb_iattr); 1372 ocfs2_set_inode_flags(inode); 1373 1374 /* fast-symlinks are a special case */ 1375 if (S_ISLNK(inode->i_mode) && !oi->ip_clusters) 1376 inode->i_blocks = 0; 1377 else 1378 inode->i_blocks = 1379 ocfs2_align_bytes_to_sectors(i_size_read(inode)); 1380 1381 inode->i_uid = be32_to_cpu(lvb->lvb_iuid); 1382 inode->i_gid = be32_to_cpu(lvb->lvb_igid); 1383 inode->i_mode = be16_to_cpu(lvb->lvb_imode); 1384 inode->i_nlink = be16_to_cpu(lvb->lvb_inlink); 1385 ocfs2_unpack_timespec(&inode->i_atime, 1386 be64_to_cpu(lvb->lvb_iatime_packed)); 1387 ocfs2_unpack_timespec(&inode->i_mtime, 1388 be64_to_cpu(lvb->lvb_imtime_packed)); 1389 ocfs2_unpack_timespec(&inode->i_ctime, 1390 be64_to_cpu(lvb->lvb_ictime_packed)); 1391 spin_unlock(&oi->ip_lock); 1392 1393 mlog_exit_void(); 1394} 1395 1396static inline int ocfs2_meta_lvb_is_trustable(struct inode *inode, 1397 struct ocfs2_lock_res *lockres) 1398{ 1399 struct ocfs2_meta_lvb *lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb; 1400 1401 if (lvb->lvb_version == OCFS2_LVB_VERSION 1402 && be32_to_cpu(lvb->lvb_igeneration) == inode->i_generation) 1403 return 1; 1404 return 0; 1405} 1406 1407/* Determine whether a lock resource needs to be refreshed, and 1408 * arbitrate who gets to refresh it. 1409 * 1410 * 0 means no refresh needed. 1411 * 1412 * > 0 means you need to refresh this and you MUST call 1413 * ocfs2_complete_lock_res_refresh afterwards. */ 1414static int ocfs2_should_refresh_lock_res(struct ocfs2_lock_res *lockres) 1415{ 1416 unsigned long flags; 1417 int status = 0; 1418 1419 mlog_entry_void(); 1420 1421refresh_check: 1422 spin_lock_irqsave(&lockres->l_lock, flags); 1423 if (!(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) { 1424 spin_unlock_irqrestore(&lockres->l_lock, flags); 1425 goto bail; 1426 } 1427 1428 if (lockres->l_flags & OCFS2_LOCK_REFRESHING) { 1429 spin_unlock_irqrestore(&lockres->l_lock, flags); 1430 1431 ocfs2_wait_on_refreshing_lock(lockres); 1432 goto refresh_check; 1433 } 1434 1435 /* Ok, I'll be the one to refresh this lock. */ 1436 lockres_or_flags(lockres, OCFS2_LOCK_REFRESHING); 1437 spin_unlock_irqrestore(&lockres->l_lock, flags); 1438 1439 status = 1; 1440bail: 1441 mlog_exit(status); 1442 return status; 1443} 1444 1445/* If status is non zero, I'll mark it as not being in refresh 1446 * anymroe, but i won't clear the needs refresh flag. */ 1447static inline void ocfs2_complete_lock_res_refresh(struct ocfs2_lock_res *lockres, 1448 int status) 1449{ 1450 unsigned long flags; 1451 mlog_entry_void(); 1452 1453 spin_lock_irqsave(&lockres->l_lock, flags); 1454 lockres_clear_flags(lockres, OCFS2_LOCK_REFRESHING); 1455 if (!status) 1456 lockres_clear_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH); 1457 spin_unlock_irqrestore(&lockres->l_lock, flags); 1458 1459 wake_up(&lockres->l_event); 1460 1461 mlog_exit_void(); 1462} 1463 1464/* may or may not return a bh if it went to disk. */ 1465static int ocfs2_meta_lock_update(struct inode *inode, 1466 struct buffer_head **bh) 1467{ 1468 int status = 0; 1469 struct ocfs2_inode_info *oi = OCFS2_I(inode); 1470 struct ocfs2_lock_res *lockres; 1471 struct ocfs2_dinode *fe; 1472 1473 mlog_entry_void(); 1474 1475 spin_lock(&oi->ip_lock); 1476 if (oi->ip_flags & OCFS2_INODE_DELETED) { 1477 mlog(0, "Orphaned inode %llu was deleted while we " 1478 "were waiting on a lock. ip_flags = 0x%x\n", 1479 (unsigned long long)oi->ip_blkno, oi->ip_flags); 1480 spin_unlock(&oi->ip_lock); 1481 status = -ENOENT; 1482 goto bail; 1483 } 1484 spin_unlock(&oi->ip_lock); 1485 1486 lockres = &oi->ip_meta_lockres; 1487 1488 if (!ocfs2_should_refresh_lock_res(lockres)) 1489 goto bail; 1490 1491 /* This will discard any caching information we might have had 1492 * for the inode metadata. */ 1493 ocfs2_metadata_cache_purge(inode); 1494 1495 /* will do nothing for inode types that don't use the extent 1496 * map (directories, bitmap files, etc) */ 1497 ocfs2_extent_map_trunc(inode, 0); 1498 1499 if (ocfs2_meta_lvb_is_trustable(inode, lockres)) { 1500 mlog(0, "Trusting LVB on inode %llu\n", 1501 (unsigned long long)oi->ip_blkno); 1502 ocfs2_refresh_inode_from_lvb(inode); 1503 } else { 1504 /* Boo, we have to go to disk. */ 1505 /* read bh, cast, ocfs2_refresh_inode */ 1506 status = ocfs2_read_block(OCFS2_SB(inode->i_sb), oi->ip_blkno, 1507 bh, OCFS2_BH_CACHED, inode); 1508 if (status < 0) { 1509 mlog_errno(status); 1510 goto bail_refresh; 1511 } 1512 fe = (struct ocfs2_dinode *) (*bh)->b_data; 1513 1514 /* This is a good chance to make sure we're not 1515 * locking an invalid object. 1516 * 1517 * We bug on a stale inode here because we checked 1518 * above whether it was wiped from disk. The wiping 1519 * node provides a guarantee that we receive that 1520 * message and can mark the inode before dropping any 1521 * locks associated with it. */ 1522 if (!OCFS2_IS_VALID_DINODE(fe)) { 1523 OCFS2_RO_ON_INVALID_DINODE(inode->i_sb, fe); 1524 status = -EIO; 1525 goto bail_refresh; 1526 } 1527 mlog_bug_on_msg(inode->i_generation != 1528 le32_to_cpu(fe->i_generation), 1529 "Invalid dinode %llu disk generation: %u " 1530 "inode->i_generation: %u\n", 1531 (unsigned long long)oi->ip_blkno, 1532 le32_to_cpu(fe->i_generation), 1533 inode->i_generation); 1534 mlog_bug_on_msg(le64_to_cpu(fe->i_dtime) || 1535 !(fe->i_flags & cpu_to_le32(OCFS2_VALID_FL)), 1536 "Stale dinode %llu dtime: %llu flags: 0x%x\n", 1537 (unsigned long long)oi->ip_blkno, 1538 (unsigned long long)le64_to_cpu(fe->i_dtime), 1539 le32_to_cpu(fe->i_flags)); 1540 1541 ocfs2_refresh_inode(inode, fe); 1542 } 1543 1544 status = 0; 1545bail_refresh: 1546 ocfs2_complete_lock_res_refresh(lockres, status); 1547bail: 1548 mlog_exit(status); 1549 return status; 1550} 1551 1552static int ocfs2_assign_bh(struct inode *inode, 1553 struct buffer_head **ret_bh, 1554 struct buffer_head *passed_bh) 1555{ 1556 int status; 1557 1558 if (passed_bh) { 1559 /* Ok, the update went to disk for us, use the 1560 * returned bh. */ 1561 *ret_bh = passed_bh; 1562 get_bh(*ret_bh); 1563 1564 return 0; 1565 } 1566 1567 status = ocfs2_read_block(OCFS2_SB(inode->i_sb), 1568 OCFS2_I(inode)->ip_blkno, 1569 ret_bh, 1570 OCFS2_BH_CACHED, 1571 inode); 1572 if (status < 0) 1573 mlog_errno(status); 1574 1575 return status; 1576} 1577 1578/* 1579 * returns < 0 error if the callback will never be called, otherwise 1580 * the result of the lock will be communicated via the callback. 1581 */ 1582int ocfs2_meta_lock_full(struct inode *inode, 1583 struct buffer_head **ret_bh, 1584 int ex, 1585 int arg_flags) 1586{ 1587 int status, level, dlm_flags, acquired; 1588 struct ocfs2_lock_res *lockres; 1589 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1590 struct buffer_head *local_bh = NULL; 1591 1592 BUG_ON(!inode); 1593 1594 mlog_entry_void(); 1595 1596 mlog(0, "inode %llu, take %s META lock\n", 1597 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1598 ex ? "EXMODE" : "PRMODE"); 1599 1600 status = 0; 1601 acquired = 0; 1602 /* We'll allow faking a readonly metadata lock for 1603 * rodevices. */ 1604 if (ocfs2_is_hard_readonly(osb)) { 1605 if (ex) 1606 status = -EROFS; 1607 goto bail; 1608 } 1609 1610 if (!(arg_flags & OCFS2_META_LOCK_RECOVERY)) 1611 wait_event(osb->recovery_event, 1612 ocfs2_node_map_is_empty(osb, &osb->recovery_map)); 1613 1614 acquired = 0; 1615 lockres = &OCFS2_I(inode)->ip_meta_lockres; 1616 level = ex ? LKM_EXMODE : LKM_PRMODE; 1617 dlm_flags = 0; 1618 if (arg_flags & OCFS2_META_LOCK_NOQUEUE) 1619 dlm_flags |= LKM_NOQUEUE; 1620 1621 status = ocfs2_cluster_lock(osb, lockres, level, dlm_flags, arg_flags); 1622 if (status < 0) { 1623 if (status != -EAGAIN && status != -EIOCBRETRY) 1624 mlog_errno(status); 1625 goto bail; 1626 } 1627 1628 /* Notify the error cleanup path to drop the cluster lock. */ 1629 acquired = 1; 1630 1631 /* We wait twice because a node may have died while we were in 1632 * the lower dlm layers. The second time though, we've 1633 * committed to owning this lock so we don't allow signals to 1634 * abort the operation. */ 1635 if (!(arg_flags & OCFS2_META_LOCK_RECOVERY)) 1636 wait_event(osb->recovery_event, 1637 ocfs2_node_map_is_empty(osb, &osb->recovery_map)); 1638 1639 /* 1640 * We only see this flag if we're being called from 1641 * ocfs2_read_locked_inode(). It means we're locking an inode 1642 * which hasn't been populated yet, so clear the refresh flag 1643 * and let the caller handle it. 1644 */ 1645 if (inode->i_state & I_NEW) { 1646 status = 0; 1647 ocfs2_complete_lock_res_refresh(lockres, 0); 1648 goto bail; 1649 } 1650 1651 /* This is fun. The caller may want a bh back, or it may 1652 * not. ocfs2_meta_lock_update definitely wants one in, but 1653 * may or may not read one, depending on what's in the 1654 * LVB. The result of all of this is that we've *only* gone to 1655 * disk if we have to, so the complexity is worthwhile. */ 1656 status = ocfs2_meta_lock_update(inode, &local_bh); 1657 if (status < 0) { 1658 if (status != -ENOENT) 1659 mlog_errno(status); 1660 goto bail; 1661 } 1662 1663 if (ret_bh) { 1664 status = ocfs2_assign_bh(inode, ret_bh, local_bh); 1665 if (status < 0) { 1666 mlog_errno(status); 1667 goto bail; 1668 } 1669 } 1670 1671bail: 1672 if (status < 0) { 1673 if (ret_bh && (*ret_bh)) { 1674 brelse(*ret_bh); 1675 *ret_bh = NULL; 1676 } 1677 if (acquired) 1678 ocfs2_meta_unlock(inode, ex); 1679 } 1680 1681 if (local_bh) 1682 brelse(local_bh); 1683 1684 mlog_exit(status); 1685 return status; 1686} 1687 1688/* 1689 * This is working around a lock inversion between tasks acquiring DLM locks 1690 * while holding a page lock and the vote thread which blocks dlm lock acquiry 1691 * while acquiring page locks. 1692 * 1693 * ** These _with_page variantes are only intended to be called from aop 1694 * methods that hold page locks and return a very specific *positive* error 1695 * code that aop methods pass up to the VFS -- test for errors with != 0. ** 1696 * 1697 * The DLM is called such that it returns -EAGAIN if it would have blocked 1698 * waiting for the vote thread. In that case we unlock our page so the vote 1699 * thread can make progress. Once we've done this we have to return 1700 * AOP_TRUNCATED_PAGE so the aop method that called us can bubble that back up 1701 * into the VFS who will then immediately retry the aop call. 1702 * 1703 * We do a blocking lock and immediate unlock before returning, though, so that 1704 * the lock has a great chance of being cached on this node by the time the VFS 1705 * calls back to retry the aop. This has a potential to livelock as nodes 1706 * ping locks back and forth, but that's a risk we're willing to take to avoid 1707 * the lock inversion simply. 1708 */ 1709int ocfs2_meta_lock_with_page(struct inode *inode, 1710 struct buffer_head **ret_bh, 1711 int ex, 1712 struct page *page) 1713{ 1714 int ret; 1715 1716 ret = ocfs2_meta_lock_full(inode, ret_bh, ex, OCFS2_LOCK_NONBLOCK); 1717 if (ret == -EAGAIN) { 1718 unlock_page(page); 1719 if (ocfs2_meta_lock(inode, ret_bh, ex) == 0) 1720 ocfs2_meta_unlock(inode, ex); 1721 ret = AOP_TRUNCATED_PAGE; 1722 } 1723 1724 return ret; 1725} 1726 1727int ocfs2_meta_lock_atime(struct inode *inode, 1728 struct vfsmount *vfsmnt, 1729 int *level) 1730{ 1731 int ret; 1732 1733 mlog_entry_void(); 1734 ret = ocfs2_meta_lock(inode, NULL, 0); 1735 if (ret < 0) { 1736 mlog_errno(ret); 1737 return ret; 1738 } 1739 1740 /* 1741 * If we should update atime, we will get EX lock, 1742 * otherwise we just get PR lock. 1743 */ 1744 if (ocfs2_should_update_atime(inode, vfsmnt)) { 1745 struct buffer_head *bh = NULL; 1746 1747 ocfs2_meta_unlock(inode, 0); 1748 ret = ocfs2_meta_lock(inode, &bh, 1); 1749 if (ret < 0) { 1750 mlog_errno(ret); 1751 return ret; 1752 } 1753 *level = 1; 1754 if (ocfs2_should_update_atime(inode, vfsmnt)) 1755 ocfs2_update_inode_atime(inode, bh); 1756 if (bh) 1757 brelse(bh); 1758 } else 1759 *level = 0; 1760 1761 mlog_exit(ret); 1762 return ret; 1763} 1764 1765void ocfs2_meta_unlock(struct inode *inode, 1766 int ex) 1767{ 1768 int level = ex ? LKM_EXMODE : LKM_PRMODE; 1769 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_meta_lockres; 1770 1771 mlog_entry_void(); 1772 1773 mlog(0, "inode %llu drop %s META lock\n", 1774 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1775 ex ? "EXMODE" : "PRMODE"); 1776 1777 if (!ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb))) 1778 ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level); 1779 1780 mlog_exit_void(); 1781} 1782 1783int ocfs2_super_lock(struct ocfs2_super *osb, 1784 int ex) 1785{ 1786 int status; 1787 int level = ex ? LKM_EXMODE : LKM_PRMODE; 1788 struct ocfs2_lock_res *lockres = &osb->osb_super_lockres; 1789 struct buffer_head *bh; 1790 struct ocfs2_slot_info *si = osb->slot_info; 1791 1792 mlog_entry_void(); 1793 1794 if (ocfs2_is_hard_readonly(osb)) 1795 return -EROFS; 1796 1797 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0); 1798 if (status < 0) { 1799 mlog_errno(status); 1800 goto bail; 1801 } 1802 1803 /* The super block lock path is really in the best position to 1804 * know when resources covered by the lock need to be 1805 * refreshed, so we do it here. Of course, making sense of 1806 * everything is up to the caller :) */ 1807 status = ocfs2_should_refresh_lock_res(lockres); 1808 if (status < 0) { 1809 mlog_errno(status); 1810 goto bail; 1811 } 1812 if (status) { 1813 bh = si->si_bh; 1814 status = ocfs2_read_block(osb, bh->b_blocknr, &bh, 0, 1815 si->si_inode); 1816 if (status == 0) 1817 ocfs2_update_slot_info(si); 1818 1819 ocfs2_complete_lock_res_refresh(lockres, status); 1820 1821 if (status < 0) 1822 mlog_errno(status); 1823 } 1824bail: 1825 mlog_exit(status); 1826 return status; 1827} 1828 1829void ocfs2_super_unlock(struct ocfs2_super *osb, 1830 int ex) 1831{ 1832 int level = ex ? LKM_EXMODE : LKM_PRMODE; 1833 struct ocfs2_lock_res *lockres = &osb->osb_super_lockres; 1834 1835 ocfs2_cluster_unlock(osb, lockres, level); 1836} 1837 1838int ocfs2_rename_lock(struct ocfs2_super *osb) 1839{ 1840 int status; 1841 struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres; 1842 1843 if (ocfs2_is_hard_readonly(osb)) 1844 return -EROFS; 1845 1846 status = ocfs2_cluster_lock(osb, lockres, LKM_EXMODE, 0, 0); 1847 if (status < 0) 1848 mlog_errno(status); 1849 1850 return status; 1851} 1852 1853void ocfs2_rename_unlock(struct ocfs2_super *osb) 1854{ 1855 struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres; 1856 1857 ocfs2_cluster_unlock(osb, lockres, LKM_EXMODE); 1858} 1859 1860int ocfs2_dentry_lock(struct dentry *dentry, int ex) 1861{ 1862 int ret; 1863 int level = ex ? LKM_EXMODE : LKM_PRMODE; 1864 struct ocfs2_dentry_lock *dl = dentry->d_fsdata; 1865 struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb); 1866 1867 BUG_ON(!dl); 1868 1869 if (ocfs2_is_hard_readonly(osb)) 1870 return -EROFS; 1871 1872 ret = ocfs2_cluster_lock(osb, &dl->dl_lockres, level, 0, 0); 1873 if (ret < 0) 1874 mlog_errno(ret); 1875 1876 return ret; 1877} 1878 1879void ocfs2_dentry_unlock(struct dentry *dentry, int ex) 1880{ 1881 int level = ex ? LKM_EXMODE : LKM_PRMODE; 1882 struct ocfs2_dentry_lock *dl = dentry->d_fsdata; 1883 struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb); 1884 1885 ocfs2_cluster_unlock(osb, &dl->dl_lockres, level); 1886} 1887 1888/* Reference counting of the dlm debug structure. We want this because 1889 * open references on the debug inodes can live on after a mount, so 1890 * we can't rely on the ocfs2_super to always exist. */ 1891static void ocfs2_dlm_debug_free(struct kref *kref) 1892{ 1893 struct ocfs2_dlm_debug *dlm_debug; 1894 1895 dlm_debug = container_of(kref, struct ocfs2_dlm_debug, d_refcnt); 1896 1897 kfree(dlm_debug); 1898} 1899 1900void ocfs2_put_dlm_debug(struct ocfs2_dlm_debug *dlm_debug) 1901{ 1902 if (dlm_debug) 1903 kref_put(&dlm_debug->d_refcnt, ocfs2_dlm_debug_free); 1904} 1905 1906static void ocfs2_get_dlm_debug(struct ocfs2_dlm_debug *debug) 1907{ 1908 kref_get(&debug->d_refcnt); 1909} 1910 1911struct ocfs2_dlm_debug *ocfs2_new_dlm_debug(void) 1912{ 1913 struct ocfs2_dlm_debug *dlm_debug; 1914 1915 dlm_debug = kmalloc(sizeof(struct ocfs2_dlm_debug), GFP_KERNEL); 1916 if (!dlm_debug) { 1917 mlog_errno(-ENOMEM); 1918 goto out; 1919 } 1920 1921 kref_init(&dlm_debug->d_refcnt); 1922 INIT_LIST_HEAD(&dlm_debug->d_lockres_tracking); 1923 dlm_debug->d_locking_state = NULL; 1924out: 1925 return dlm_debug; 1926} 1927 1928/* Access to this is arbitrated for us via seq_file->sem. */ 1929struct ocfs2_dlm_seq_priv { 1930 struct ocfs2_dlm_debug *p_dlm_debug; 1931 struct ocfs2_lock_res p_iter_res; 1932 struct ocfs2_lock_res p_tmp_res; 1933}; 1934 1935static struct ocfs2_lock_res *ocfs2_dlm_next_res(struct ocfs2_lock_res *start, 1936 struct ocfs2_dlm_seq_priv *priv) 1937{ 1938 struct ocfs2_lock_res *iter, *ret = NULL; 1939 struct ocfs2_dlm_debug *dlm_debug = priv->p_dlm_debug; 1940 1941 assert_spin_locked(&ocfs2_dlm_tracking_lock); 1942 1943 list_for_each_entry(iter, &start->l_debug_list, l_debug_list) { 1944 /* discover the head of the list */ 1945 if (&iter->l_debug_list == &dlm_debug->d_lockres_tracking) { 1946 mlog(0, "End of list found, %p\n", ret); 1947 break; 1948 } 1949 1950 /* We track our "dummy" iteration lockres' by a NULL 1951 * l_ops field. */ 1952 if (iter->l_ops != NULL) { 1953 ret = iter; 1954 break; 1955 } 1956 } 1957 1958 return ret; 1959} 1960 1961static void *ocfs2_dlm_seq_start(struct seq_file *m, loff_t *pos) 1962{ 1963 struct ocfs2_dlm_seq_priv *priv = m->private; 1964 struct ocfs2_lock_res *iter; 1965 1966 spin_lock(&ocfs2_dlm_tracking_lock); 1967 iter = ocfs2_dlm_next_res(&priv->p_iter_res, priv); 1968 if (iter) { 1969 /* Since lockres' have the lifetime of their container 1970 * (which can be inodes, ocfs2_supers, etc) we want to 1971 * copy this out to a temporary lockres while still 1972 * under the spinlock. Obviously after this we can't 1973 * trust any pointers on the copy returned, but that's 1974 * ok as the information we want isn't typically held 1975 * in them. */ 1976 priv->p_tmp_res = *iter; 1977 iter = &priv->p_tmp_res; 1978 } 1979 spin_unlock(&ocfs2_dlm_tracking_lock); 1980 1981 return iter; 1982} 1983 1984static void ocfs2_dlm_seq_stop(struct seq_file *m, void *v) 1985{ 1986} 1987 1988static void *ocfs2_dlm_seq_next(struct seq_file *m, void *v, loff_t *pos) 1989{ 1990 struct ocfs2_dlm_seq_priv *priv = m->private; 1991 struct ocfs2_lock_res *iter = v; 1992 struct ocfs2_lock_res *dummy = &priv->p_iter_res; 1993 1994 spin_lock(&ocfs2_dlm_tracking_lock); 1995 iter = ocfs2_dlm_next_res(iter, priv); 1996 list_del_init(&dummy->l_debug_list); 1997 if (iter) { 1998 list_add(&dummy->l_debug_list, &iter->l_debug_list); 1999 priv->p_tmp_res = *iter; 2000 iter = &priv->p_tmp_res; 2001 } 2002 spin_unlock(&ocfs2_dlm_tracking_lock); 2003 2004 return iter; 2005} 2006 2007/* So that debugfs.ocfs2 can determine which format is being used */ 2008#define OCFS2_DLM_DEBUG_STR_VERSION 1 2009static int ocfs2_dlm_seq_show(struct seq_file *m, void *v) 2010{ 2011 int i; 2012 char *lvb; 2013 struct ocfs2_lock_res *lockres = v; 2014 2015 if (!lockres) 2016 return -EINVAL; 2017 2018 seq_printf(m, "0x%x\t", OCFS2_DLM_DEBUG_STR_VERSION); 2019 2020 if (lockres->l_type == OCFS2_LOCK_TYPE_DENTRY) 2021 seq_printf(m, "%.*s%08x\t", OCFS2_DENTRY_LOCK_INO_START - 1, 2022 lockres->l_name, 2023 (unsigned int)ocfs2_get_dentry_lock_ino(lockres)); 2024 else 2025 seq_printf(m, "%.*s\t", OCFS2_LOCK_ID_MAX_LEN, lockres->l_name); 2026 2027 seq_printf(m, "%d\t" 2028 "0x%lx\t" 2029 "0x%x\t" 2030 "0x%x\t" 2031 "%u\t" 2032 "%u\t" 2033 "%d\t" 2034 "%d\t", 2035 lockres->l_level, 2036 lockres->l_flags, 2037 lockres->l_action, 2038 lockres->l_unlock_action, 2039 lockres->l_ro_holders, 2040 lockres->l_ex_holders, 2041 lockres->l_requested, 2042 lockres->l_blocking); 2043 2044 /* Dump the raw LVB */ 2045 lvb = lockres->l_lksb.lvb; 2046 for(i = 0; i < DLM_LVB_LEN; i++) 2047 seq_printf(m, "0x%x\t", lvb[i]); 2048 2049 /* End the line */ 2050 seq_printf(m, "\n"); 2051 return 0; 2052} 2053 2054static struct seq_operations ocfs2_dlm_seq_ops = { 2055 .start = ocfs2_dlm_seq_start, 2056 .stop = ocfs2_dlm_seq_stop, 2057 .next = ocfs2_dlm_seq_next, 2058 .show = ocfs2_dlm_seq_show, 2059}; 2060 2061static int ocfs2_dlm_debug_release(struct inode *inode, struct file *file) 2062{ 2063 struct seq_file *seq = (struct seq_file *) file->private_data; 2064 struct ocfs2_dlm_seq_priv *priv = seq->private; 2065 struct ocfs2_lock_res *res = &priv->p_iter_res; 2066 2067 ocfs2_remove_lockres_tracking(res); 2068 ocfs2_put_dlm_debug(priv->p_dlm_debug); 2069 return seq_release_private(inode, file); 2070} 2071 2072static int ocfs2_dlm_debug_open(struct inode *inode, struct file *file) 2073{ 2074 int ret; 2075 struct ocfs2_dlm_seq_priv *priv; 2076 struct seq_file *seq; 2077 struct ocfs2_super *osb; 2078 2079 priv = kzalloc(sizeof(struct ocfs2_dlm_seq_priv), GFP_KERNEL); 2080 if (!priv) { 2081 ret = -ENOMEM; 2082 mlog_errno(ret); 2083 goto out; 2084 } 2085 osb = inode->i_private; 2086 ocfs2_get_dlm_debug(osb->osb_dlm_debug); 2087 priv->p_dlm_debug = osb->osb_dlm_debug; 2088 INIT_LIST_HEAD(&priv->p_iter_res.l_debug_list); 2089 2090 ret = seq_open(file, &ocfs2_dlm_seq_ops); 2091 if (ret) { 2092 kfree(priv); 2093 mlog_errno(ret); 2094 goto out; 2095 } 2096 2097 seq = (struct seq_file *) file->private_data; 2098 seq->private = priv; 2099 2100 ocfs2_add_lockres_tracking(&priv->p_iter_res, 2101 priv->p_dlm_debug); 2102 2103out: 2104 return ret; 2105} 2106 2107static const struct file_operations ocfs2_dlm_debug_fops = { 2108 .open = ocfs2_dlm_debug_open, 2109 .release = ocfs2_dlm_debug_release, 2110 .read = seq_read, 2111 .llseek = seq_lseek, 2112}; 2113 2114static int ocfs2_dlm_init_debug(struct ocfs2_super *osb) 2115{ 2116 int ret = 0; 2117 struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug; 2118 2119 dlm_debug->d_locking_state = debugfs_create_file("locking_state", 2120 S_IFREG|S_IRUSR, 2121 osb->osb_debug_root, 2122 osb, 2123 &ocfs2_dlm_debug_fops); 2124 if (!dlm_debug->d_locking_state) { 2125 ret = -EINVAL; 2126 mlog(ML_ERROR, 2127 "Unable to create locking state debugfs file.\n"); 2128 goto out; 2129 } 2130 2131 ocfs2_get_dlm_debug(dlm_debug); 2132out: 2133 return ret; 2134} 2135 2136static void ocfs2_dlm_shutdown_debug(struct ocfs2_super *osb) 2137{ 2138 struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug; 2139 2140 if (dlm_debug) { 2141 debugfs_remove(dlm_debug->d_locking_state); 2142 ocfs2_put_dlm_debug(dlm_debug); 2143 } 2144} 2145 2146int ocfs2_dlm_init(struct ocfs2_super *osb) 2147{ 2148 int status; 2149 u32 dlm_key; 2150 struct dlm_ctxt *dlm; 2151 2152 mlog_entry_void(); 2153 2154 status = ocfs2_dlm_init_debug(osb); 2155 if (status < 0) { 2156 mlog_errno(status); 2157 goto bail; 2158 } 2159 2160 /* launch vote thread */ 2161 osb->vote_task = kthread_run(ocfs2_vote_thread, osb, "ocfs2vote"); 2162 if (IS_ERR(osb->vote_task)) { 2163 status = PTR_ERR(osb->vote_task); 2164 osb->vote_task = NULL; 2165 mlog_errno(status); 2166 goto bail; 2167 } 2168 2169 /* used by the dlm code to make message headers unique, each 2170 * node in this domain must agree on this. */ 2171 dlm_key = crc32_le(0, osb->uuid_str, strlen(osb->uuid_str)); 2172 2173 /* for now, uuid == domain */ 2174 dlm = dlm_register_domain(osb->uuid_str, dlm_key); 2175 if (IS_ERR(dlm)) { 2176 status = PTR_ERR(dlm); 2177 mlog_errno(status); 2178 goto bail; 2179 } 2180 2181 ocfs2_super_lock_res_init(&osb->osb_super_lockres, osb); 2182 ocfs2_rename_lock_res_init(&osb->osb_rename_lockres, osb); 2183 2184 dlm_register_eviction_cb(dlm, &osb->osb_eviction_cb); 2185 2186 osb->dlm = dlm; 2187 2188 status = 0; 2189bail: 2190 if (status < 0) { 2191 ocfs2_dlm_shutdown_debug(osb); 2192 if (osb->vote_task) 2193 kthread_stop(osb->vote_task); 2194 } 2195 2196 mlog_exit(status); 2197 return status; 2198} 2199 2200void ocfs2_dlm_shutdown(struct ocfs2_super *osb) 2201{ 2202 mlog_entry_void(); 2203 2204 dlm_unregister_eviction_cb(&osb->osb_eviction_cb); 2205 2206 ocfs2_drop_osb_locks(osb); 2207 2208 if (osb->vote_task) { 2209 kthread_stop(osb->vote_task); 2210 osb->vote_task = NULL; 2211 } 2212 2213 ocfs2_lock_res_free(&osb->osb_super_lockres); 2214 ocfs2_lock_res_free(&osb->osb_rename_lockres); 2215 2216 dlm_unregister_domain(osb->dlm); 2217 osb->dlm = NULL; 2218 2219 ocfs2_dlm_shutdown_debug(osb); 2220 2221 mlog_exit_void(); 2222} 2223 2224static void ocfs2_unlock_ast(void *opaque, enum dlm_status status) 2225{ 2226 struct ocfs2_lock_res *lockres = opaque; 2227 unsigned long flags; 2228 2229 mlog_entry_void(); 2230 2231 mlog(0, "UNLOCK AST called on lock %s, action = %d\n", lockres->l_name, 2232 lockres->l_unlock_action); 2233 2234 spin_lock_irqsave(&lockres->l_lock, flags); 2235 /* We tried to cancel a convert request, but it was already 2236 * granted. All we want to do here is clear our unlock 2237 * state. The wake_up call done at the bottom is redundant 2238 * (ocfs2_prepare_cancel_convert doesn't sleep on this) but doesn't 2239 * hurt anything anyway */ 2240 if (status == DLM_CANCELGRANT && 2241 lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) { 2242 mlog(0, "Got cancelgrant for %s\n", lockres->l_name); 2243 2244 /* We don't clear the busy flag in this case as it 2245 * should have been cleared by the ast which the dlm 2246 * has called. */ 2247 goto complete_unlock; 2248 } 2249 2250 if (status != DLM_NORMAL) { 2251 mlog(ML_ERROR, "Dlm passes status %d for lock %s, " 2252 "unlock_action %d\n", status, lockres->l_name, 2253 lockres->l_unlock_action); 2254 spin_unlock_irqrestore(&lockres->l_lock, flags); 2255 return; 2256 } 2257 2258 switch(lockres->l_unlock_action) { 2259 case OCFS2_UNLOCK_CANCEL_CONVERT: 2260 mlog(0, "Cancel convert success for %s\n", lockres->l_name); 2261 lockres->l_action = OCFS2_AST_INVALID; 2262 break; 2263 case OCFS2_UNLOCK_DROP_LOCK: 2264 lockres->l_level = LKM_IVMODE; 2265 break; 2266 default: 2267 BUG(); 2268 } 2269 2270 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); 2271complete_unlock: 2272 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID; 2273 spin_unlock_irqrestore(&lockres->l_lock, flags); 2274 2275 wake_up(&lockres->l_event); 2276 2277 mlog_exit_void(); 2278} 2279 2280static int ocfs2_drop_lock(struct ocfs2_super *osb, 2281 struct ocfs2_lock_res *lockres) 2282{ 2283 enum dlm_status status; 2284 unsigned long flags; 2285 int lkm_flags = 0; 2286 2287 /* We didn't get anywhere near actually using this lockres. */ 2288 if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED)) 2289 goto out; 2290 2291 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) 2292 lkm_flags |= LKM_VALBLK; 2293 2294 spin_lock_irqsave(&lockres->l_lock, flags); 2295 2296 mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_FREEING), 2297 "lockres %s, flags 0x%lx\n", 2298 lockres->l_name, lockres->l_flags); 2299 2300 while (lockres->l_flags & OCFS2_LOCK_BUSY) { 2301 mlog(0, "waiting on busy lock \"%s\": flags = %lx, action = " 2302 "%u, unlock_action = %u\n", 2303 lockres->l_name, lockres->l_flags, lockres->l_action, 2304 lockres->l_unlock_action); 2305 2306 spin_unlock_irqrestore(&lockres->l_lock, flags); 2307 2308 /* XXX: Today we just wait on any busy 2309 * locks... Perhaps we need to cancel converts in the 2310 * future? */ 2311 ocfs2_wait_on_busy_lock(lockres); 2312 2313 spin_lock_irqsave(&lockres->l_lock, flags); 2314 } 2315 2316 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) { 2317 if (lockres->l_flags & OCFS2_LOCK_ATTACHED && 2318 lockres->l_level == LKM_EXMODE && 2319 !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) 2320 lockres->l_ops->set_lvb(lockres); 2321 } 2322 2323 if (lockres->l_flags & OCFS2_LOCK_BUSY) 2324 mlog(ML_ERROR, "destroying busy lock: \"%s\"\n", 2325 lockres->l_name); 2326 if (lockres->l_flags & OCFS2_LOCK_BLOCKED) 2327 mlog(0, "destroying blocked lock: \"%s\"\n", lockres->l_name); 2328 2329 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) { 2330 spin_unlock_irqrestore(&lockres->l_lock, flags); 2331 goto out; 2332 } 2333 2334 lockres_clear_flags(lockres, OCFS2_LOCK_ATTACHED); 2335 2336 /* make sure we never get here while waiting for an ast to 2337 * fire. */ 2338 BUG_ON(lockres->l_action != OCFS2_AST_INVALID); 2339 2340 /* is this necessary? */ 2341 lockres_or_flags(lockres, OCFS2_LOCK_BUSY); 2342 lockres->l_unlock_action = OCFS2_UNLOCK_DROP_LOCK; 2343 spin_unlock_irqrestore(&lockres->l_lock, flags); 2344 2345 mlog(0, "lock %s\n", lockres->l_name); 2346 2347 status = dlmunlock(osb->dlm, &lockres->l_lksb, lkm_flags, 2348 ocfs2_unlock_ast, lockres); 2349 if (status != DLM_NORMAL) { 2350 ocfs2_log_dlm_error("dlmunlock", status, lockres); 2351 mlog(ML_ERROR, "lockres flags: %lu\n", lockres->l_flags); 2352 dlm_print_one_lock(lockres->l_lksb.lockid); 2353 BUG(); 2354 } 2355 mlog(0, "lock %s, successfull return from dlmunlock\n", 2356 lockres->l_name); 2357 2358 ocfs2_wait_on_busy_lock(lockres); 2359out: 2360 mlog_exit(0); 2361 return 0; 2362} 2363 2364/* Mark the lockres as being dropped. It will no longer be 2365 * queued if blocking, but we still may have to wait on it 2366 * being dequeued from the vote thread before we can consider 2367 * it safe to drop. 2368 * 2369 * You can *not* attempt to call cluster_lock on this lockres anymore. */ 2370void ocfs2_mark_lockres_freeing(struct ocfs2_lock_res *lockres) 2371{ 2372 int status; 2373 struct ocfs2_mask_waiter mw; 2374 unsigned long flags; 2375 2376 ocfs2_init_mask_waiter(&mw); 2377 2378 spin_lock_irqsave(&lockres->l_lock, flags); 2379 lockres->l_flags |= OCFS2_LOCK_FREEING; 2380 while (lockres->l_flags & OCFS2_LOCK_QUEUED) { 2381 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_QUEUED, 0); 2382 spin_unlock_irqrestore(&lockres->l_lock, flags); 2383 2384 mlog(0, "Waiting on lockres %s\n", lockres->l_name); 2385 2386 status = ocfs2_wait_for_mask(&mw); 2387 if (status) 2388 mlog_errno(status); 2389 2390 spin_lock_irqsave(&lockres->l_lock, flags); 2391 } 2392 spin_unlock_irqrestore(&lockres->l_lock, flags); 2393} 2394 2395void ocfs2_simple_drop_lockres(struct ocfs2_super *osb, 2396 struct ocfs2_lock_res *lockres) 2397{ 2398 int ret; 2399 2400 ocfs2_mark_lockres_freeing(lockres); 2401 ret = ocfs2_drop_lock(osb, lockres); 2402 if (ret) 2403 mlog_errno(ret); 2404} 2405 2406static void ocfs2_drop_osb_locks(struct ocfs2_super *osb) 2407{ 2408 ocfs2_simple_drop_lockres(osb, &osb->osb_super_lockres); 2409 ocfs2_simple_drop_lockres(osb, &osb->osb_rename_lockres); 2410} 2411 2412int ocfs2_drop_inode_locks(struct inode *inode) 2413{ 2414 int status, err; 2415 2416 mlog_entry_void(); 2417 2418 /* No need to call ocfs2_mark_lockres_freeing here - 2419 * ocfs2_clear_inode has done it for us. */ 2420 2421 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb), 2422 &OCFS2_I(inode)->ip_data_lockres); 2423 if (err < 0) 2424 mlog_errno(err); 2425 2426 status = err; 2427 2428 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb), 2429 &OCFS2_I(inode)->ip_meta_lockres); 2430 if (err < 0) 2431 mlog_errno(err); 2432 if (err < 0 && !status) 2433 status = err; 2434 2435 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb), 2436 &OCFS2_I(inode)->ip_rw_lockres); 2437 if (err < 0) 2438 mlog_errno(err); 2439 if (err < 0 && !status) 2440 status = err; 2441 2442 mlog_exit(status); 2443 return status; 2444} 2445 2446static void ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres, 2447 int new_level) 2448{ 2449 assert_spin_locked(&lockres->l_lock); 2450 2451 BUG_ON(lockres->l_blocking <= LKM_NLMODE); 2452 2453 if (lockres->l_level <= new_level) { 2454 mlog(ML_ERROR, "lockres->l_level (%u) <= new_level (%u)\n", 2455 lockres->l_level, new_level); 2456 BUG(); 2457 } 2458 2459 mlog(0, "lock %s, new_level = %d, l_blocking = %d\n", 2460 lockres->l_name, new_level, lockres->l_blocking); 2461 2462 lockres->l_action = OCFS2_AST_DOWNCONVERT; 2463 lockres->l_requested = new_level; 2464 lockres_or_flags(lockres, OCFS2_LOCK_BUSY); 2465} 2466 2467static int ocfs2_downconvert_lock(struct ocfs2_super *osb, 2468 struct ocfs2_lock_res *lockres, 2469 int new_level, 2470 int lvb) 2471{ 2472 int ret, dlm_flags = LKM_CONVERT; 2473 enum dlm_status status; 2474 2475 mlog_entry_void(); 2476 2477 if (lvb) 2478 dlm_flags |= LKM_VALBLK; 2479 2480 status = dlmlock(osb->dlm, 2481 new_level, 2482 &lockres->l_lksb, 2483 dlm_flags, 2484 lockres->l_name, 2485 OCFS2_LOCK_ID_MAX_LEN - 1, 2486 ocfs2_locking_ast, 2487 lockres, 2488 ocfs2_blocking_ast); 2489 if (status != DLM_NORMAL) { 2490 ocfs2_log_dlm_error("dlmlock", status, lockres); 2491 ret = -EINVAL; 2492 ocfs2_recover_from_dlm_error(lockres, 1); 2493 goto bail; 2494 } 2495 2496 ret = 0; 2497bail: 2498 mlog_exit(ret); 2499 return ret; 2500} 2501 2502/* returns 1 when the caller should unlock and call dlmunlock */ 2503static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb, 2504 struct ocfs2_lock_res *lockres) 2505{ 2506 assert_spin_locked(&lockres->l_lock); 2507 2508 mlog_entry_void(); 2509 mlog(0, "lock %s\n", lockres->l_name); 2510 2511 if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) { 2512 /* If we're already trying to cancel a lock conversion 2513 * then just drop the spinlock and allow the caller to 2514 * requeue this lock. */ 2515 2516 mlog(0, "Lockres %s, skip convert\n", lockres->l_name); 2517 return 0; 2518 } 2519 2520 /* were we in a convert when we got the bast fire? */ 2521 BUG_ON(lockres->l_action != OCFS2_AST_CONVERT && 2522 lockres->l_action != OCFS2_AST_DOWNCONVERT); 2523 /* set things up for the unlockast to know to just 2524 * clear out the ast_action and unset busy, etc. */ 2525 lockres->l_unlock_action = OCFS2_UNLOCK_CANCEL_CONVERT; 2526 2527 mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_BUSY), 2528 "lock %s, invalid flags: 0x%lx\n", 2529 lockres->l_name, lockres->l_flags); 2530 2531 return 1; 2532} 2533 2534static int ocfs2_cancel_convert(struct ocfs2_super *osb, 2535 struct ocfs2_lock_res *lockres) 2536{ 2537 int ret; 2538 enum dlm_status status; 2539 2540 mlog_entry_void(); 2541 mlog(0, "lock %s\n", lockres->l_name); 2542 2543 ret = 0; 2544 status = dlmunlock(osb->dlm, 2545 &lockres->l_lksb, 2546 LKM_CANCEL, 2547 ocfs2_unlock_ast, 2548 lockres); 2549 if (status != DLM_NORMAL) { 2550 ocfs2_log_dlm_error("dlmunlock", status, lockres); 2551 ret = -EINVAL; 2552 ocfs2_recover_from_dlm_error(lockres, 0); 2553 } 2554 2555 mlog(0, "lock %s return from dlmunlock\n", lockres->l_name); 2556 2557 mlog_exit(ret); 2558 return ret; 2559} 2560 2561static int ocfs2_unblock_lock(struct ocfs2_super *osb, 2562 struct ocfs2_lock_res *lockres, 2563 struct ocfs2_unblock_ctl *ctl) 2564{ 2565 unsigned long flags; 2566 int blocking; 2567 int new_level; 2568 int ret = 0; 2569 int set_lvb = 0; 2570 2571 mlog_entry_void(); 2572 2573 spin_lock_irqsave(&lockres->l_lock, flags); 2574 2575 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED)); 2576 2577recheck: 2578 if (lockres->l_flags & OCFS2_LOCK_BUSY) { 2579 ctl->requeue = 1; 2580 ret = ocfs2_prepare_cancel_convert(osb, lockres); 2581 spin_unlock_irqrestore(&lockres->l_lock, flags); 2582 if (ret) { 2583 ret = ocfs2_cancel_convert(osb, lockres); 2584 if (ret < 0) 2585 mlog_errno(ret); 2586 } 2587 goto leave; 2588 } 2589 2590 /* if we're blocking an exclusive and we have *any* holders, 2591 * then requeue. */ 2592 if ((lockres->l_blocking == LKM_EXMODE) 2593 && (lockres->l_ex_holders || lockres->l_ro_holders)) 2594 goto leave_requeue; 2595 2596 /* If it's a PR we're blocking, then only 2597 * requeue if we've got any EX holders */ 2598 if (lockres->l_blocking == LKM_PRMODE && 2599 lockres->l_ex_holders) 2600 goto leave_requeue; 2601 2602 /* 2603 * Can we get a lock in this state if the holder counts are 2604 * zero? The meta data unblock code used to check this. 2605 */ 2606 if ((lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH) 2607 && (lockres->l_flags & OCFS2_LOCK_REFRESHING)) 2608 goto leave_requeue; 2609 2610 new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking); 2611 2612 if (lockres->l_ops->check_downconvert 2613 && !lockres->l_ops->check_downconvert(lockres, new_level)) 2614 goto leave_requeue; 2615 2616 /* If we get here, then we know that there are no more 2617 * incompatible holders (and anyone asking for an incompatible 2618 * lock is blocked). We can now downconvert the lock */ 2619 if (!lockres->l_ops->downconvert_worker) 2620 goto downconvert; 2621 2622 /* Some lockres types want to do a bit of work before 2623 * downconverting a lock. Allow that here. The worker function 2624 * may sleep, so we save off a copy of what we're blocking as 2625 * it may change while we're not holding the spin lock. */ 2626 blocking = lockres->l_blocking; 2627 spin_unlock_irqrestore(&lockres->l_lock, flags); 2628 2629 ctl->unblock_action = lockres->l_ops->downconvert_worker(lockres, blocking); 2630 2631 if (ctl->unblock_action == UNBLOCK_STOP_POST) 2632 goto leave; 2633 2634 spin_lock_irqsave(&lockres->l_lock, flags); 2635 if (blocking != lockres->l_blocking) { 2636 /* If this changed underneath us, then we can't drop 2637 * it just yet. */ 2638 goto recheck; 2639 } 2640 2641downconvert: 2642 ctl->requeue = 0; 2643 2644 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) { 2645 if (lockres->l_level == LKM_EXMODE) 2646 set_lvb = 1; 2647 2648 /* 2649 * We only set the lvb if the lock has been fully 2650 * refreshed - otherwise we risk setting stale 2651 * data. Otherwise, there's no need to actually clear 2652 * out the lvb here as it's value is still valid. 2653 */ 2654 if (set_lvb && !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) 2655 lockres->l_ops->set_lvb(lockres); 2656 } 2657 2658 ocfs2_prepare_downconvert(lockres, new_level); 2659 spin_unlock_irqrestore(&lockres->l_lock, flags); 2660 ret = ocfs2_downconvert_lock(osb, lockres, new_level, set_lvb); 2661leave: 2662 mlog_exit(ret); 2663 return ret; 2664 2665leave_requeue: 2666 spin_unlock_irqrestore(&lockres->l_lock, flags); 2667 ctl->requeue = 1; 2668 2669 mlog_exit(0); 2670 return 0; 2671} 2672 2673static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres, 2674 int blocking) 2675{ 2676 struct inode *inode; 2677 struct address_space *mapping; 2678 2679 inode = ocfs2_lock_res_inode(lockres); 2680 mapping = inode->i_mapping; 2681 2682 if (filemap_fdatawrite(mapping)) { 2683 mlog(ML_ERROR, "Could not sync inode %llu for downconvert!", 2684 (unsigned long long)OCFS2_I(inode)->ip_blkno); 2685 } 2686 sync_mapping_buffers(mapping); 2687 if (blocking == LKM_EXMODE) { 2688 truncate_inode_pages(mapping, 0); 2689 unmap_mapping_range(mapping, 0, 0, 0); 2690 } else { 2691 /* We only need to wait on the I/O if we're not also 2692 * truncating pages because truncate_inode_pages waits 2693 * for us above. We don't truncate pages if we're 2694 * blocking anything < EXMODE because we want to keep 2695 * them around in that case. */ 2696 filemap_fdatawait(mapping); 2697 } 2698 2699 return UNBLOCK_CONTINUE; 2700} 2701 2702static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres, 2703 int new_level) 2704{ 2705 struct inode *inode = ocfs2_lock_res_inode(lockres); 2706 int checkpointed = ocfs2_inode_fully_checkpointed(inode); 2707 2708 BUG_ON(new_level != LKM_NLMODE && new_level != LKM_PRMODE); 2709 BUG_ON(lockres->l_level != LKM_EXMODE && !checkpointed); 2710 2711 if (checkpointed) 2712 return 1; 2713 2714 ocfs2_start_checkpoint(OCFS2_SB(inode->i_sb)); 2715 return 0; 2716} 2717 2718static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres) 2719{ 2720 struct inode *inode = ocfs2_lock_res_inode(lockres); 2721 2722 __ocfs2_stuff_meta_lvb(inode); 2723} 2724 2725/* 2726 * Does the final reference drop on our dentry lock. Right now this 2727 * happens in the vote thread, but we could choose to simplify the 2728 * dlmglue API and push these off to the ocfs2_wq in the future. 2729 */ 2730static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb, 2731 struct ocfs2_lock_res *lockres) 2732{ 2733 struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres); 2734 ocfs2_dentry_lock_put(osb, dl); 2735} 2736 2737/* 2738 * d_delete() matching dentries before the lock downconvert. 2739 * 2740 * At this point, any process waiting to destroy the 2741 * dentry_lock due to last ref count is stopped by the 2742 * OCFS2_LOCK_QUEUED flag. 2743 * 2744 * We have two potential problems 2745 * 2746 * 1) If we do the last reference drop on our dentry_lock (via dput) 2747 * we'll wind up in ocfs2_release_dentry_lock(), waiting on 2748 * the downconvert to finish. Instead we take an elevated 2749 * reference and push the drop until after we've completed our 2750 * unblock processing. 2751 * 2752 * 2) There might be another process with a final reference, 2753 * waiting on us to finish processing. If this is the case, we 2754 * detect it and exit out - there's no more dentries anyway. 2755 */ 2756static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres, 2757 int blocking) 2758{ 2759 struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres); 2760 struct ocfs2_inode_info *oi = OCFS2_I(dl->dl_inode); 2761 struct dentry *dentry; 2762 unsigned long flags; 2763 int extra_ref = 0; 2764 2765 /* 2766 * This node is blocking another node from getting a read 2767 * lock. This happens when we've renamed within a 2768 * directory. We've forced the other nodes to d_delete(), but 2769 * we never actually dropped our lock because it's still 2770 * valid. The downconvert code will retain a PR for this node, 2771 * so there's no further work to do. 2772 */ 2773 if (blocking == LKM_PRMODE) 2774 return UNBLOCK_CONTINUE; 2775 2776 /* 2777 * Mark this inode as potentially orphaned. The code in 2778 * ocfs2_delete_inode() will figure out whether it actually 2779 * needs to be freed or not. 2780 */ 2781 spin_lock(&oi->ip_lock); 2782 oi->ip_flags |= OCFS2_INODE_MAYBE_ORPHANED; 2783 spin_unlock(&oi->ip_lock); 2784 2785 /* 2786 * Yuck. We need to make sure however that the check of 2787 * OCFS2_LOCK_FREEING and the extra reference are atomic with 2788 * respect to a reference decrement or the setting of that 2789 * flag. 2790 */ 2791 spin_lock_irqsave(&lockres->l_lock, flags); 2792 spin_lock(&dentry_attach_lock); 2793 if (!(lockres->l_flags & OCFS2_LOCK_FREEING) 2794 && dl->dl_count) { 2795 dl->dl_count++; 2796 extra_ref = 1; 2797 } 2798 spin_unlock(&dentry_attach_lock); 2799 spin_unlock_irqrestore(&lockres->l_lock, flags); 2800 2801 mlog(0, "extra_ref = %d\n", extra_ref); 2802 2803 /* 2804 * We have a process waiting on us in ocfs2_dentry_iput(), 2805 * which means we can't have any more outstanding 2806 * aliases. There's no need to do any more work. 2807 */ 2808 if (!extra_ref) 2809 return UNBLOCK_CONTINUE; 2810 2811 spin_lock(&dentry_attach_lock); 2812 while (1) { 2813 dentry = ocfs2_find_local_alias(dl->dl_inode, 2814 dl->dl_parent_blkno, 1); 2815 if (!dentry) 2816 break; 2817 spin_unlock(&dentry_attach_lock); 2818 2819 mlog(0, "d_delete(%.*s);\n", dentry->d_name.len, 2820 dentry->d_name.name); 2821 2822 /* 2823 * The following dcache calls may do an 2824 * iput(). Normally we don't want that from the 2825 * downconverting thread, but in this case it's ok 2826 * because the requesting node already has an 2827 * exclusive lock on the inode, so it can't be queued 2828 * for a downconvert. 2829 */ 2830 d_delete(dentry); 2831 dput(dentry); 2832 2833 spin_lock(&dentry_attach_lock); 2834 } 2835 spin_unlock(&dentry_attach_lock); 2836 2837 /* 2838 * If we are the last holder of this dentry lock, there is no 2839 * reason to downconvert so skip straight to the unlock. 2840 */ 2841 if (dl->dl_count == 1) 2842 return UNBLOCK_STOP_POST; 2843 2844 return UNBLOCK_CONTINUE_POST; 2845} 2846 2847void ocfs2_process_blocked_lock(struct ocfs2_super *osb, 2848 struct ocfs2_lock_res *lockres) 2849{ 2850 int status; 2851 struct ocfs2_unblock_ctl ctl = {0, 0,}; 2852 unsigned long flags; 2853 2854 /* Our reference to the lockres in this function can be 2855 * considered valid until we remove the OCFS2_LOCK_QUEUED 2856 * flag. */ 2857 2858 mlog_entry_void(); 2859 2860 BUG_ON(!lockres); 2861 BUG_ON(!lockres->l_ops); 2862 2863 mlog(0, "lockres %s blocked.\n", lockres->l_name); 2864 2865 /* Detect whether a lock has been marked as going away while 2866 * the vote thread was processing other things. A lock can 2867 * still be marked with OCFS2_LOCK_FREEING after this check, 2868 * but short circuiting here will still save us some 2869 * performance. */ 2870 spin_lock_irqsave(&lockres->l_lock, flags); 2871 if (lockres->l_flags & OCFS2_LOCK_FREEING) 2872 goto unqueue; 2873 spin_unlock_irqrestore(&lockres->l_lock, flags); 2874 2875 status = ocfs2_unblock_lock(osb, lockres, &ctl); 2876 if (status < 0) 2877 mlog_errno(status); 2878 2879 spin_lock_irqsave(&lockres->l_lock, flags); 2880unqueue: 2881 if (lockres->l_flags & OCFS2_LOCK_FREEING || !ctl.requeue) { 2882 lockres_clear_flags(lockres, OCFS2_LOCK_QUEUED); 2883 } else 2884 ocfs2_schedule_blocked_lock(osb, lockres); 2885 2886 mlog(0, "lockres %s, requeue = %s.\n", lockres->l_name, 2887 ctl.requeue ? "yes" : "no"); 2888 spin_unlock_irqrestore(&lockres->l_lock, flags); 2889 2890 if (ctl.unblock_action != UNBLOCK_CONTINUE 2891 && lockres->l_ops->post_unlock) 2892 lockres->l_ops->post_unlock(osb, lockres); 2893 2894 mlog_exit_void(); 2895} 2896 2897static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb, 2898 struct ocfs2_lock_res *lockres) 2899{ 2900 mlog_entry_void(); 2901 2902 assert_spin_locked(&lockres->l_lock); 2903 2904 if (lockres->l_flags & OCFS2_LOCK_FREEING) { 2905 /* Do not schedule a lock for downconvert when it's on 2906 * the way to destruction - any nodes wanting access 2907 * to the resource will get it soon. */ 2908 mlog(0, "Lockres %s won't be scheduled: flags 0x%lx\n", 2909 lockres->l_name, lockres->l_flags); 2910 return; 2911 } 2912 2913 lockres_or_flags(lockres, OCFS2_LOCK_QUEUED); 2914 2915 spin_lock(&osb->vote_task_lock); 2916 if (list_empty(&lockres->l_blocked_list)) { 2917 list_add_tail(&lockres->l_blocked_list, 2918 &osb->blocked_lock_list); 2919 osb->blocked_lock_count++; 2920 } 2921 spin_unlock(&osb->vote_task_lock); 2922 2923 mlog_exit_void(); 2924} 2925 2926/* This aids in debugging situations where a bad LVB might be involved. */ 2927void ocfs2_dump_meta_lvb_info(u64 level, 2928 const char *function, 2929 unsigned int line, 2930 struct ocfs2_lock_res *lockres) 2931{ 2932 struct ocfs2_meta_lvb *lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb; 2933 2934 mlog(level, "LVB information for %s (called from %s:%u):\n", 2935 lockres->l_name, function, line); 2936 mlog(level, "version: %u, clusters: %u, generation: 0x%x\n", 2937 lvb->lvb_version, be32_to_cpu(lvb->lvb_iclusters), 2938 be32_to_cpu(lvb->lvb_igeneration)); 2939 mlog(level, "size: %llu, uid %u, gid %u, mode 0x%x\n", 2940 (unsigned long long)be64_to_cpu(lvb->lvb_isize), 2941 be32_to_cpu(lvb->lvb_iuid), be32_to_cpu(lvb->lvb_igid), 2942 be16_to_cpu(lvb->lvb_imode)); 2943 mlog(level, "nlink %u, atime_packed 0x%llx, ctime_packed 0x%llx, " 2944 "mtime_packed 0x%llx iattr 0x%x\n", be16_to_cpu(lvb->lvb_inlink), 2945 (long long)be64_to_cpu(lvb->lvb_iatime_packed), 2946 (long long)be64_to_cpu(lvb->lvb_ictime_packed), 2947 (long long)be64_to_cpu(lvb->lvb_imtime_packed), 2948 be32_to_cpu(lvb->lvb_iattr)); 2949} 2950