1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* -*- mode: c; c-basic-offset: 8; -*- 3 * vim: noexpandtab sw=8 ts=8 sts=0: 4 * 5 * dlmglue.c 6 * 7 * Code which implements an OCFS2 specific interface to our DLM. 8 * 9 * Copyright (C) 2003, 2004 Oracle. All rights reserved. 10 */ 11 12 #include <linux/types.h> 13 #include <linux/slab.h> 14 #include <linux/highmem.h> 15 #include <linux/mm.h> 16 #include <linux/kthread.h> 17 #include <linux/pagemap.h> 18 #include <linux/debugfs.h> 19 #include <linux/seq_file.h> 20 #include <linux/time.h> 21 #include <linux/quotaops.h> 22 #include <linux/sched/signal.h> 23 24 #define MLOG_MASK_PREFIX ML_DLM_GLUE 25 #include <cluster/masklog.h> 26 27 #include "ocfs2.h" 28 #include "ocfs2_lockingver.h" 29 30 #include "alloc.h" 31 #include "dcache.h" 32 #include "dlmglue.h" 33 #include "extent_map.h" 34 #include "file.h" 35 #include "heartbeat.h" 36 #include "inode.h" 37 #include "journal.h" 38 #include "stackglue.h" 39 #include "slot_map.h" 40 #include "super.h" 41 #include "uptodate.h" 42 #include "quota.h" 43 #include "refcounttree.h" 44 #include "acl.h" 45 46 #include "buffer_head_io.h" 47 48 struct ocfs2_mask_waiter { 49 struct list_head mw_item; 50 int mw_status; 51 struct completion mw_complete; 52 unsigned long mw_mask; 53 unsigned long mw_goal; 54 #ifdef CONFIG_OCFS2_FS_STATS 55 ktime_t mw_lock_start; 56 #endif 57 }; 58 59 static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres); 60 static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres); 61 static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres); 62 static struct ocfs2_super *ocfs2_get_qinfo_osb(struct ocfs2_lock_res *lockres); 63 64 /* 65 * Return value from ->downconvert_worker functions. 66 * 67 * These control the precise actions of ocfs2_unblock_lock() 68 * and ocfs2_process_blocked_lock() 69 * 70 */ 71 enum ocfs2_unblock_action { 72 UNBLOCK_CONTINUE = 0, /* Continue downconvert */ 73 UNBLOCK_CONTINUE_POST = 1, /* Continue downconvert, fire 74 * ->post_unlock callback */ 75 UNBLOCK_STOP_POST = 2, /* Do not downconvert, fire 76 * ->post_unlock() callback. */ 77 }; 78 79 struct ocfs2_unblock_ctl { 80 int requeue; 81 enum ocfs2_unblock_action unblock_action; 82 }; 83 84 /* Lockdep class keys */ 85 #ifdef CONFIG_DEBUG_LOCK_ALLOC 86 static struct lock_class_key lockdep_keys[OCFS2_NUM_LOCK_TYPES]; 87 #endif 88 89 static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres, 90 int new_level); 91 static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres); 92 93 static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres, 94 int blocking); 95 96 static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres, 97 int blocking); 98 99 static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb, 100 struct ocfs2_lock_res *lockres); 101 102 static void ocfs2_set_qinfo_lvb(struct ocfs2_lock_res *lockres); 103 104 static int ocfs2_check_refcount_downconvert(struct ocfs2_lock_res *lockres, 105 int new_level); 106 static int ocfs2_refcount_convert_worker(struct ocfs2_lock_res *lockres, 107 int blocking); 108 109 #define mlog_meta_lvb(__level, __lockres) ocfs2_dump_meta_lvb_info(__level, __PRETTY_FUNCTION__, __LINE__, __lockres) 110 111 /* This aids in debugging situations where a bad LVB might be involved. */ 112 static void ocfs2_dump_meta_lvb_info(u64 level, 113 const char *function, 114 unsigned int line, 115 struct ocfs2_lock_res *lockres) 116 { 117 struct ocfs2_meta_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb); 118 119 mlog(level, "LVB information for %s (called from %s:%u):\n", 120 lockres->l_name, function, line); 121 mlog(level, "version: %u, clusters: %u, generation: 0x%x\n", 122 lvb->lvb_version, be32_to_cpu(lvb->lvb_iclusters), 123 be32_to_cpu(lvb->lvb_igeneration)); 124 mlog(level, "size: %llu, uid %u, gid %u, mode 0x%x\n", 125 (unsigned long long)be64_to_cpu(lvb->lvb_isize), 126 be32_to_cpu(lvb->lvb_iuid), be32_to_cpu(lvb->lvb_igid), 127 be16_to_cpu(lvb->lvb_imode)); 128 mlog(level, "nlink %u, atime_packed 0x%llx, ctime_packed 0x%llx, " 129 "mtime_packed 0x%llx iattr 0x%x\n", be16_to_cpu(lvb->lvb_inlink), 130 (long long)be64_to_cpu(lvb->lvb_iatime_packed), 131 (long long)be64_to_cpu(lvb->lvb_ictime_packed), 132 (long long)be64_to_cpu(lvb->lvb_imtime_packed), 133 be32_to_cpu(lvb->lvb_iattr)); 134 } 135 136 137 /* 138 * OCFS2 Lock Resource Operations 139 * 140 * These fine tune the behavior of the generic dlmglue locking infrastructure. 141 * 142 * The most basic of lock types can point ->l_priv to their respective 143 * struct ocfs2_super and allow the default actions to manage things. 144 * 145 * Right now, each lock type also needs to implement an init function, 146 * and trivial lock/unlock wrappers. ocfs2_simple_drop_lockres() 147 * should be called when the lock is no longer needed (i.e., object 148 * destruction time). 149 */ 150 struct ocfs2_lock_res_ops { 151 /* 152 * Translate an ocfs2_lock_res * into an ocfs2_super *. Define 153 * this callback if ->l_priv is not an ocfs2_super pointer 154 */ 155 struct ocfs2_super * (*get_osb)(struct ocfs2_lock_res *); 156 157 /* 158 * Optionally called in the downconvert thread after a 159 * successful downconvert. The lockres will not be referenced 160 * after this callback is called, so it is safe to free 161 * memory, etc. 162 * 163 * The exact semantics of when this is called are controlled 164 * by ->downconvert_worker() 165 */ 166 void (*post_unlock)(struct ocfs2_super *, struct ocfs2_lock_res *); 167 168 /* 169 * Allow a lock type to add checks to determine whether it is 170 * safe to downconvert a lock. Return 0 to re-queue the 171 * downconvert at a later time, nonzero to continue. 172 * 173 * For most locks, the default checks that there are no 174 * incompatible holders are sufficient. 175 * 176 * Called with the lockres spinlock held. 177 */ 178 int (*check_downconvert)(struct ocfs2_lock_res *, int); 179 180 /* 181 * Allows a lock type to populate the lock value block. This 182 * is called on downconvert, and when we drop a lock. 183 * 184 * Locks that want to use this should set LOCK_TYPE_USES_LVB 185 * in the flags field. 186 * 187 * Called with the lockres spinlock held. 188 */ 189 void (*set_lvb)(struct ocfs2_lock_res *); 190 191 /* 192 * Called from the downconvert thread when it is determined 193 * that a lock will be downconverted. This is called without 194 * any locks held so the function can do work that might 195 * schedule (syncing out data, etc). 196 * 197 * This should return any one of the ocfs2_unblock_action 198 * values, depending on what it wants the thread to do. 199 */ 200 int (*downconvert_worker)(struct ocfs2_lock_res *, int); 201 202 /* 203 * LOCK_TYPE_* flags which describe the specific requirements 204 * of a lock type. Descriptions of each individual flag follow. 205 */ 206 int flags; 207 }; 208 209 /* 210 * Some locks want to "refresh" potentially stale data when a 211 * meaningful (PRMODE or EXMODE) lock level is first obtained. If this 212 * flag is set, the OCFS2_LOCK_NEEDS_REFRESH flag will be set on the 213 * individual lockres l_flags member from the ast function. It is 214 * expected that the locking wrapper will clear the 215 * OCFS2_LOCK_NEEDS_REFRESH flag when done. 216 */ 217 #define LOCK_TYPE_REQUIRES_REFRESH 0x1 218 219 /* 220 * Indicate that a lock type makes use of the lock value block. The 221 * ->set_lvb lock type callback must be defined. 222 */ 223 #define LOCK_TYPE_USES_LVB 0x2 224 225 static struct ocfs2_lock_res_ops ocfs2_inode_rw_lops = { 226 .get_osb = ocfs2_get_inode_osb, 227 .flags = 0, 228 }; 229 230 static struct ocfs2_lock_res_ops ocfs2_inode_inode_lops = { 231 .get_osb = ocfs2_get_inode_osb, 232 .check_downconvert = ocfs2_check_meta_downconvert, 233 .set_lvb = ocfs2_set_meta_lvb, 234 .downconvert_worker = ocfs2_data_convert_worker, 235 .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB, 236 }; 237 238 static struct ocfs2_lock_res_ops ocfs2_super_lops = { 239 .flags = LOCK_TYPE_REQUIRES_REFRESH, 240 }; 241 242 static struct ocfs2_lock_res_ops ocfs2_rename_lops = { 243 .flags = 0, 244 }; 245 246 static struct ocfs2_lock_res_ops ocfs2_nfs_sync_lops = { 247 .flags = 0, 248 }; 249 250 static struct ocfs2_lock_res_ops ocfs2_trim_fs_lops = { 251 .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB, 252 }; 253 254 static struct ocfs2_lock_res_ops ocfs2_orphan_scan_lops = { 255 .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB, 256 }; 257 258 static struct ocfs2_lock_res_ops ocfs2_dentry_lops = { 259 .get_osb = ocfs2_get_dentry_osb, 260 .post_unlock = ocfs2_dentry_post_unlock, 261 .downconvert_worker = ocfs2_dentry_convert_worker, 262 .flags = 0, 263 }; 264 265 static struct ocfs2_lock_res_ops ocfs2_inode_open_lops = { 266 .get_osb = ocfs2_get_inode_osb, 267 .flags = 0, 268 }; 269 270 static struct ocfs2_lock_res_ops ocfs2_flock_lops = { 271 .get_osb = ocfs2_get_file_osb, 272 .flags = 0, 273 }; 274 275 static struct ocfs2_lock_res_ops ocfs2_qinfo_lops = { 276 .set_lvb = ocfs2_set_qinfo_lvb, 277 .get_osb = ocfs2_get_qinfo_osb, 278 .flags = LOCK_TYPE_REQUIRES_REFRESH | LOCK_TYPE_USES_LVB, 279 }; 280 281 static struct ocfs2_lock_res_ops ocfs2_refcount_block_lops = { 282 .check_downconvert = ocfs2_check_refcount_downconvert, 283 .downconvert_worker = ocfs2_refcount_convert_worker, 284 .flags = 0, 285 }; 286 287 static inline int ocfs2_is_inode_lock(struct ocfs2_lock_res *lockres) 288 { 289 return lockres->l_type == OCFS2_LOCK_TYPE_META || 290 lockres->l_type == OCFS2_LOCK_TYPE_RW || 291 lockres->l_type == OCFS2_LOCK_TYPE_OPEN; 292 } 293 294 static inline struct ocfs2_lock_res *ocfs2_lksb_to_lock_res(struct ocfs2_dlm_lksb *lksb) 295 { 296 return container_of(lksb, struct ocfs2_lock_res, l_lksb); 297 } 298 299 static inline struct inode *ocfs2_lock_res_inode(struct ocfs2_lock_res *lockres) 300 { 301 BUG_ON(!ocfs2_is_inode_lock(lockres)); 302 303 return (struct inode *) lockres->l_priv; 304 } 305 306 static inline struct ocfs2_dentry_lock *ocfs2_lock_res_dl(struct ocfs2_lock_res *lockres) 307 { 308 BUG_ON(lockres->l_type != OCFS2_LOCK_TYPE_DENTRY); 309 310 return (struct ocfs2_dentry_lock *)lockres->l_priv; 311 } 312 313 static inline struct ocfs2_mem_dqinfo *ocfs2_lock_res_qinfo(struct ocfs2_lock_res *lockres) 314 { 315 BUG_ON(lockres->l_type != OCFS2_LOCK_TYPE_QINFO); 316 317 return (struct ocfs2_mem_dqinfo *)lockres->l_priv; 318 } 319 320 static inline struct ocfs2_refcount_tree * 321 ocfs2_lock_res_refcount_tree(struct ocfs2_lock_res *res) 322 { 323 return container_of(res, struct ocfs2_refcount_tree, rf_lockres); 324 } 325 326 static inline struct ocfs2_super *ocfs2_get_lockres_osb(struct ocfs2_lock_res *lockres) 327 { 328 if (lockres->l_ops->get_osb) 329 return lockres->l_ops->get_osb(lockres); 330 331 return (struct ocfs2_super *)lockres->l_priv; 332 } 333 334 static int ocfs2_lock_create(struct ocfs2_super *osb, 335 struct ocfs2_lock_res *lockres, 336 int level, 337 u32 dlm_flags); 338 static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres, 339 int wanted); 340 static void __ocfs2_cluster_unlock(struct ocfs2_super *osb, 341 struct ocfs2_lock_res *lockres, 342 int level, unsigned long caller_ip); 343 static inline void ocfs2_cluster_unlock(struct ocfs2_super *osb, 344 struct ocfs2_lock_res *lockres, 345 int level) 346 { 347 __ocfs2_cluster_unlock(osb, lockres, level, _RET_IP_); 348 } 349 350 static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres); 351 static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres); 352 static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres); 353 static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres, int level); 354 static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb, 355 struct ocfs2_lock_res *lockres); 356 static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres, 357 int convert); 358 #define ocfs2_log_dlm_error(_func, _err, _lockres) do { \ 359 if ((_lockres)->l_type != OCFS2_LOCK_TYPE_DENTRY) \ 360 mlog(ML_ERROR, "DLM error %d while calling %s on resource %s\n", \ 361 _err, _func, _lockres->l_name); \ 362 else \ 363 mlog(ML_ERROR, "DLM error %d while calling %s on resource %.*s%08x\n", \ 364 _err, _func, OCFS2_DENTRY_LOCK_INO_START - 1, (_lockres)->l_name, \ 365 (unsigned int)ocfs2_get_dentry_lock_ino(_lockres)); \ 366 } while (0) 367 static int ocfs2_downconvert_thread(void *arg); 368 static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb, 369 struct ocfs2_lock_res *lockres); 370 static int ocfs2_inode_lock_update(struct inode *inode, 371 struct buffer_head **bh); 372 static void ocfs2_drop_osb_locks(struct ocfs2_super *osb); 373 static inline int ocfs2_highest_compat_lock_level(int level); 374 static unsigned int ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres, 375 int new_level); 376 static int ocfs2_downconvert_lock(struct ocfs2_super *osb, 377 struct ocfs2_lock_res *lockres, 378 int new_level, 379 int lvb, 380 unsigned int generation); 381 static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb, 382 struct ocfs2_lock_res *lockres); 383 static int ocfs2_cancel_convert(struct ocfs2_super *osb, 384 struct ocfs2_lock_res *lockres); 385 386 387 static void ocfs2_build_lock_name(enum ocfs2_lock_type type, 388 u64 blkno, 389 u32 generation, 390 char *name) 391 { 392 int len; 393 394 BUG_ON(type >= OCFS2_NUM_LOCK_TYPES); 395 396 len = snprintf(name, OCFS2_LOCK_ID_MAX_LEN, "%c%s%016llx%08x", 397 ocfs2_lock_type_char(type), OCFS2_LOCK_ID_PAD, 398 (long long)blkno, generation); 399 400 BUG_ON(len != (OCFS2_LOCK_ID_MAX_LEN - 1)); 401 402 mlog(0, "built lock resource with name: %s\n", name); 403 } 404 405 static DEFINE_SPINLOCK(ocfs2_dlm_tracking_lock); 406 407 static void ocfs2_add_lockres_tracking(struct ocfs2_lock_res *res, 408 struct ocfs2_dlm_debug *dlm_debug) 409 { 410 mlog(0, "Add tracking for lockres %s\n", res->l_name); 411 412 spin_lock(&ocfs2_dlm_tracking_lock); 413 list_add(&res->l_debug_list, &dlm_debug->d_lockres_tracking); 414 spin_unlock(&ocfs2_dlm_tracking_lock); 415 } 416 417 static void ocfs2_remove_lockres_tracking(struct ocfs2_lock_res *res) 418 { 419 spin_lock(&ocfs2_dlm_tracking_lock); 420 if (!list_empty(&res->l_debug_list)) 421 list_del_init(&res->l_debug_list); 422 spin_unlock(&ocfs2_dlm_tracking_lock); 423 } 424 425 #ifdef CONFIG_OCFS2_FS_STATS 426 static void ocfs2_init_lock_stats(struct ocfs2_lock_res *res) 427 { 428 res->l_lock_refresh = 0; 429 res->l_lock_wait = 0; 430 memset(&res->l_lock_prmode, 0, sizeof(struct ocfs2_lock_stats)); 431 memset(&res->l_lock_exmode, 0, sizeof(struct ocfs2_lock_stats)); 432 } 433 434 static void ocfs2_update_lock_stats(struct ocfs2_lock_res *res, int level, 435 struct ocfs2_mask_waiter *mw, int ret) 436 { 437 u32 usec; 438 ktime_t kt; 439 struct ocfs2_lock_stats *stats; 440 441 if (level == LKM_PRMODE) 442 stats = &res->l_lock_prmode; 443 else if (level == LKM_EXMODE) 444 stats = &res->l_lock_exmode; 445 else 446 return; 447 448 kt = ktime_sub(ktime_get(), mw->mw_lock_start); 449 usec = ktime_to_us(kt); 450 451 stats->ls_gets++; 452 stats->ls_total += ktime_to_ns(kt); 453 /* overflow */ 454 if (unlikely(stats->ls_gets == 0)) { 455 stats->ls_gets++; 456 stats->ls_total = ktime_to_ns(kt); 457 } 458 459 if (stats->ls_max < usec) 460 stats->ls_max = usec; 461 462 if (ret) 463 stats->ls_fail++; 464 465 stats->ls_last = ktime_to_us(ktime_get_real()); 466 } 467 468 static inline void ocfs2_track_lock_refresh(struct ocfs2_lock_res *lockres) 469 { 470 lockres->l_lock_refresh++; 471 } 472 473 static inline void ocfs2_track_lock_wait(struct ocfs2_lock_res *lockres) 474 { 475 struct ocfs2_mask_waiter *mw; 476 477 if (list_empty(&lockres->l_mask_waiters)) { 478 lockres->l_lock_wait = 0; 479 return; 480 } 481 482 mw = list_first_entry(&lockres->l_mask_waiters, 483 struct ocfs2_mask_waiter, mw_item); 484 lockres->l_lock_wait = 485 ktime_to_us(ktime_mono_to_real(mw->mw_lock_start)); 486 } 487 488 static inline void ocfs2_init_start_time(struct ocfs2_mask_waiter *mw) 489 { 490 mw->mw_lock_start = ktime_get(); 491 } 492 #else 493 static inline void ocfs2_init_lock_stats(struct ocfs2_lock_res *res) 494 { 495 } 496 static inline void ocfs2_update_lock_stats(struct ocfs2_lock_res *res, 497 int level, struct ocfs2_mask_waiter *mw, int ret) 498 { 499 } 500 static inline void ocfs2_track_lock_refresh(struct ocfs2_lock_res *lockres) 501 { 502 } 503 static inline void ocfs2_track_lock_wait(struct ocfs2_lock_res *lockres) 504 { 505 } 506 static inline void ocfs2_init_start_time(struct ocfs2_mask_waiter *mw) 507 { 508 } 509 #endif 510 511 static void ocfs2_lock_res_init_common(struct ocfs2_super *osb, 512 struct ocfs2_lock_res *res, 513 enum ocfs2_lock_type type, 514 struct ocfs2_lock_res_ops *ops, 515 void *priv) 516 { 517 res->l_type = type; 518 res->l_ops = ops; 519 res->l_priv = priv; 520 521 res->l_level = DLM_LOCK_IV; 522 res->l_requested = DLM_LOCK_IV; 523 res->l_blocking = DLM_LOCK_IV; 524 res->l_action = OCFS2_AST_INVALID; 525 res->l_unlock_action = OCFS2_UNLOCK_INVALID; 526 527 res->l_flags = OCFS2_LOCK_INITIALIZED; 528 529 ocfs2_add_lockres_tracking(res, osb->osb_dlm_debug); 530 531 ocfs2_init_lock_stats(res); 532 #ifdef CONFIG_DEBUG_LOCK_ALLOC 533 if (type != OCFS2_LOCK_TYPE_OPEN) 534 lockdep_init_map(&res->l_lockdep_map, ocfs2_lock_type_strings[type], 535 &lockdep_keys[type], 0); 536 else 537 res->l_lockdep_map.key = NULL; 538 #endif 539 } 540 541 void ocfs2_lock_res_init_once(struct ocfs2_lock_res *res) 542 { 543 /* This also clears out the lock status block */ 544 memset(res, 0, sizeof(struct ocfs2_lock_res)); 545 spin_lock_init(&res->l_lock); 546 init_waitqueue_head(&res->l_event); 547 INIT_LIST_HEAD(&res->l_blocked_list); 548 INIT_LIST_HEAD(&res->l_mask_waiters); 549 INIT_LIST_HEAD(&res->l_holders); 550 } 551 552 void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res, 553 enum ocfs2_lock_type type, 554 unsigned int generation, 555 struct inode *inode) 556 { 557 struct ocfs2_lock_res_ops *ops; 558 559 switch(type) { 560 case OCFS2_LOCK_TYPE_RW: 561 ops = &ocfs2_inode_rw_lops; 562 break; 563 case OCFS2_LOCK_TYPE_META: 564 ops = &ocfs2_inode_inode_lops; 565 break; 566 case OCFS2_LOCK_TYPE_OPEN: 567 ops = &ocfs2_inode_open_lops; 568 break; 569 default: 570 mlog_bug_on_msg(1, "type: %d\n", type); 571 ops = NULL; /* thanks, gcc */ 572 break; 573 }; 574 575 ocfs2_build_lock_name(type, OCFS2_I(inode)->ip_blkno, 576 generation, res->l_name); 577 ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), res, type, ops, inode); 578 } 579 580 static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres) 581 { 582 struct inode *inode = ocfs2_lock_res_inode(lockres); 583 584 return OCFS2_SB(inode->i_sb); 585 } 586 587 static struct ocfs2_super *ocfs2_get_qinfo_osb(struct ocfs2_lock_res *lockres) 588 { 589 struct ocfs2_mem_dqinfo *info = lockres->l_priv; 590 591 return OCFS2_SB(info->dqi_gi.dqi_sb); 592 } 593 594 static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres) 595 { 596 struct ocfs2_file_private *fp = lockres->l_priv; 597 598 return OCFS2_SB(fp->fp_file->f_mapping->host->i_sb); 599 } 600 601 static __u64 ocfs2_get_dentry_lock_ino(struct ocfs2_lock_res *lockres) 602 { 603 __be64 inode_blkno_be; 604 605 memcpy(&inode_blkno_be, &lockres->l_name[OCFS2_DENTRY_LOCK_INO_START], 606 sizeof(__be64)); 607 608 return be64_to_cpu(inode_blkno_be); 609 } 610 611 static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres) 612 { 613 struct ocfs2_dentry_lock *dl = lockres->l_priv; 614 615 return OCFS2_SB(dl->dl_inode->i_sb); 616 } 617 618 void ocfs2_dentry_lock_res_init(struct ocfs2_dentry_lock *dl, 619 u64 parent, struct inode *inode) 620 { 621 int len; 622 u64 inode_blkno = OCFS2_I(inode)->ip_blkno; 623 __be64 inode_blkno_be = cpu_to_be64(inode_blkno); 624 struct ocfs2_lock_res *lockres = &dl->dl_lockres; 625 626 ocfs2_lock_res_init_once(lockres); 627 628 /* 629 * Unfortunately, the standard lock naming scheme won't work 630 * here because we have two 16 byte values to use. Instead, 631 * we'll stuff the inode number as a binary value. We still 632 * want error prints to show something without garbling the 633 * display, so drop a null byte in there before the inode 634 * number. A future version of OCFS2 will likely use all 635 * binary lock names. The stringified names have been a 636 * tremendous aid in debugging, but now that the debugfs 637 * interface exists, we can mangle things there if need be. 638 * 639 * NOTE: We also drop the standard "pad" value (the total lock 640 * name size stays the same though - the last part is all 641 * zeros due to the memset in ocfs2_lock_res_init_once() 642 */ 643 len = snprintf(lockres->l_name, OCFS2_DENTRY_LOCK_INO_START, 644 "%c%016llx", 645 ocfs2_lock_type_char(OCFS2_LOCK_TYPE_DENTRY), 646 (long long)parent); 647 648 BUG_ON(len != (OCFS2_DENTRY_LOCK_INO_START - 1)); 649 650 memcpy(&lockres->l_name[OCFS2_DENTRY_LOCK_INO_START], &inode_blkno_be, 651 sizeof(__be64)); 652 653 ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), lockres, 654 OCFS2_LOCK_TYPE_DENTRY, &ocfs2_dentry_lops, 655 dl); 656 } 657 658 static void ocfs2_super_lock_res_init(struct ocfs2_lock_res *res, 659 struct ocfs2_super *osb) 660 { 661 /* Superblock lockres doesn't come from a slab so we call init 662 * once on it manually. */ 663 ocfs2_lock_res_init_once(res); 664 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_SUPER, OCFS2_SUPER_BLOCK_BLKNO, 665 0, res->l_name); 666 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_SUPER, 667 &ocfs2_super_lops, osb); 668 } 669 670 static void ocfs2_rename_lock_res_init(struct ocfs2_lock_res *res, 671 struct ocfs2_super *osb) 672 { 673 /* Rename lockres doesn't come from a slab so we call init 674 * once on it manually. */ 675 ocfs2_lock_res_init_once(res); 676 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_RENAME, 0, 0, res->l_name); 677 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_RENAME, 678 &ocfs2_rename_lops, osb); 679 } 680 681 static void ocfs2_nfs_sync_lock_res_init(struct ocfs2_lock_res *res, 682 struct ocfs2_super *osb) 683 { 684 /* nfs_sync lockres doesn't come from a slab so we call init 685 * once on it manually. */ 686 ocfs2_lock_res_init_once(res); 687 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_NFS_SYNC, 0, 0, res->l_name); 688 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_NFS_SYNC, 689 &ocfs2_nfs_sync_lops, osb); 690 } 691 692 void ocfs2_trim_fs_lock_res_init(struct ocfs2_super *osb) 693 { 694 struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres; 695 696 /* Only one trimfs thread are allowed to work at the same time. */ 697 mutex_lock(&osb->obs_trim_fs_mutex); 698 699 ocfs2_lock_res_init_once(lockres); 700 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_TRIM_FS, 0, 0, lockres->l_name); 701 ocfs2_lock_res_init_common(osb, lockres, OCFS2_LOCK_TYPE_TRIM_FS, 702 &ocfs2_trim_fs_lops, osb); 703 } 704 705 void ocfs2_trim_fs_lock_res_uninit(struct ocfs2_super *osb) 706 { 707 struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres; 708 709 ocfs2_simple_drop_lockres(osb, lockres); 710 ocfs2_lock_res_free(lockres); 711 712 mutex_unlock(&osb->obs_trim_fs_mutex); 713 } 714 715 static void ocfs2_orphan_scan_lock_res_init(struct ocfs2_lock_res *res, 716 struct ocfs2_super *osb) 717 { 718 ocfs2_lock_res_init_once(res); 719 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_ORPHAN_SCAN, 0, 0, res->l_name); 720 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_ORPHAN_SCAN, 721 &ocfs2_orphan_scan_lops, osb); 722 } 723 724 void ocfs2_file_lock_res_init(struct ocfs2_lock_res *lockres, 725 struct ocfs2_file_private *fp) 726 { 727 struct inode *inode = fp->fp_file->f_mapping->host; 728 struct ocfs2_inode_info *oi = OCFS2_I(inode); 729 730 ocfs2_lock_res_init_once(lockres); 731 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_FLOCK, oi->ip_blkno, 732 inode->i_generation, lockres->l_name); 733 ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), lockres, 734 OCFS2_LOCK_TYPE_FLOCK, &ocfs2_flock_lops, 735 fp); 736 lockres->l_flags |= OCFS2_LOCK_NOCACHE; 737 } 738 739 void ocfs2_qinfo_lock_res_init(struct ocfs2_lock_res *lockres, 740 struct ocfs2_mem_dqinfo *info) 741 { 742 ocfs2_lock_res_init_once(lockres); 743 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_QINFO, info->dqi_gi.dqi_type, 744 0, lockres->l_name); 745 ocfs2_lock_res_init_common(OCFS2_SB(info->dqi_gi.dqi_sb), lockres, 746 OCFS2_LOCK_TYPE_QINFO, &ocfs2_qinfo_lops, 747 info); 748 } 749 750 void ocfs2_refcount_lock_res_init(struct ocfs2_lock_res *lockres, 751 struct ocfs2_super *osb, u64 ref_blkno, 752 unsigned int generation) 753 { 754 ocfs2_lock_res_init_once(lockres); 755 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_REFCOUNT, ref_blkno, 756 generation, lockres->l_name); 757 ocfs2_lock_res_init_common(osb, lockres, OCFS2_LOCK_TYPE_REFCOUNT, 758 &ocfs2_refcount_block_lops, osb); 759 } 760 761 void ocfs2_lock_res_free(struct ocfs2_lock_res *res) 762 { 763 if (!(res->l_flags & OCFS2_LOCK_INITIALIZED)) 764 return; 765 766 ocfs2_remove_lockres_tracking(res); 767 768 mlog_bug_on_msg(!list_empty(&res->l_blocked_list), 769 "Lockres %s is on the blocked list\n", 770 res->l_name); 771 mlog_bug_on_msg(!list_empty(&res->l_mask_waiters), 772 "Lockres %s has mask waiters pending\n", 773 res->l_name); 774 mlog_bug_on_msg(spin_is_locked(&res->l_lock), 775 "Lockres %s is locked\n", 776 res->l_name); 777 mlog_bug_on_msg(res->l_ro_holders, 778 "Lockres %s has %u ro holders\n", 779 res->l_name, res->l_ro_holders); 780 mlog_bug_on_msg(res->l_ex_holders, 781 "Lockres %s has %u ex holders\n", 782 res->l_name, res->l_ex_holders); 783 784 /* Need to clear out the lock status block for the dlm */ 785 memset(&res->l_lksb, 0, sizeof(res->l_lksb)); 786 787 res->l_flags = 0UL; 788 } 789 790 /* 791 * Keep a list of processes who have interest in a lockres. 792 * Note: this is now only uesed for check recursive cluster locking. 793 */ 794 static inline void ocfs2_add_holder(struct ocfs2_lock_res *lockres, 795 struct ocfs2_lock_holder *oh) 796 { 797 INIT_LIST_HEAD(&oh->oh_list); 798 oh->oh_owner_pid = get_pid(task_pid(current)); 799 800 spin_lock(&lockres->l_lock); 801 list_add_tail(&oh->oh_list, &lockres->l_holders); 802 spin_unlock(&lockres->l_lock); 803 } 804 805 static struct ocfs2_lock_holder * 806 ocfs2_pid_holder(struct ocfs2_lock_res *lockres, 807 struct pid *pid) 808 { 809 struct ocfs2_lock_holder *oh; 810 811 spin_lock(&lockres->l_lock); 812 list_for_each_entry(oh, &lockres->l_holders, oh_list) { 813 if (oh->oh_owner_pid == pid) { 814 spin_unlock(&lockres->l_lock); 815 return oh; 816 } 817 } 818 spin_unlock(&lockres->l_lock); 819 return NULL; 820 } 821 822 static inline void ocfs2_remove_holder(struct ocfs2_lock_res *lockres, 823 struct ocfs2_lock_holder *oh) 824 { 825 spin_lock(&lockres->l_lock); 826 list_del(&oh->oh_list); 827 spin_unlock(&lockres->l_lock); 828 829 put_pid(oh->oh_owner_pid); 830 } 831 832 833 static inline void ocfs2_inc_holders(struct ocfs2_lock_res *lockres, 834 int level) 835 { 836 BUG_ON(!lockres); 837 838 switch(level) { 839 case DLM_LOCK_EX: 840 lockres->l_ex_holders++; 841 break; 842 case DLM_LOCK_PR: 843 lockres->l_ro_holders++; 844 break; 845 default: 846 BUG(); 847 } 848 } 849 850 static inline void ocfs2_dec_holders(struct ocfs2_lock_res *lockres, 851 int level) 852 { 853 BUG_ON(!lockres); 854 855 switch(level) { 856 case DLM_LOCK_EX: 857 BUG_ON(!lockres->l_ex_holders); 858 lockres->l_ex_holders--; 859 break; 860 case DLM_LOCK_PR: 861 BUG_ON(!lockres->l_ro_holders); 862 lockres->l_ro_holders--; 863 break; 864 default: 865 BUG(); 866 } 867 } 868 869 /* WARNING: This function lives in a world where the only three lock 870 * levels are EX, PR, and NL. It *will* have to be adjusted when more 871 * lock types are added. */ 872 static inline int ocfs2_highest_compat_lock_level(int level) 873 { 874 int new_level = DLM_LOCK_EX; 875 876 if (level == DLM_LOCK_EX) 877 new_level = DLM_LOCK_NL; 878 else if (level == DLM_LOCK_PR) 879 new_level = DLM_LOCK_PR; 880 return new_level; 881 } 882 883 static void lockres_set_flags(struct ocfs2_lock_res *lockres, 884 unsigned long newflags) 885 { 886 struct ocfs2_mask_waiter *mw, *tmp; 887 888 assert_spin_locked(&lockres->l_lock); 889 890 lockres->l_flags = newflags; 891 892 list_for_each_entry_safe(mw, tmp, &lockres->l_mask_waiters, mw_item) { 893 if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal) 894 continue; 895 896 list_del_init(&mw->mw_item); 897 mw->mw_status = 0; 898 complete(&mw->mw_complete); 899 ocfs2_track_lock_wait(lockres); 900 } 901 } 902 static void lockres_or_flags(struct ocfs2_lock_res *lockres, unsigned long or) 903 { 904 lockres_set_flags(lockres, lockres->l_flags | or); 905 } 906 static void lockres_clear_flags(struct ocfs2_lock_res *lockres, 907 unsigned long clear) 908 { 909 lockres_set_flags(lockres, lockres->l_flags & ~clear); 910 } 911 912 static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres) 913 { 914 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY)); 915 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED)); 916 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED)); 917 BUG_ON(lockres->l_blocking <= DLM_LOCK_NL); 918 919 lockres->l_level = lockres->l_requested; 920 if (lockres->l_level <= 921 ocfs2_highest_compat_lock_level(lockres->l_blocking)) { 922 lockres->l_blocking = DLM_LOCK_NL; 923 lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED); 924 } 925 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); 926 } 927 928 static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres) 929 { 930 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY)); 931 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED)); 932 933 /* Convert from RO to EX doesn't really need anything as our 934 * information is already up to data. Convert from NL to 935 * *anything* however should mark ourselves as needing an 936 * update */ 937 if (lockres->l_level == DLM_LOCK_NL && 938 lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH) 939 lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH); 940 941 lockres->l_level = lockres->l_requested; 942 943 /* 944 * We set the OCFS2_LOCK_UPCONVERT_FINISHING flag before clearing 945 * the OCFS2_LOCK_BUSY flag to prevent the dc thread from 946 * downconverting the lock before the upconvert has fully completed. 947 * Do not prevent the dc thread from downconverting if NONBLOCK lock 948 * had already returned. 949 */ 950 if (!(lockres->l_flags & OCFS2_LOCK_NONBLOCK_FINISHED)) 951 lockres_or_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING); 952 else 953 lockres_clear_flags(lockres, OCFS2_LOCK_NONBLOCK_FINISHED); 954 955 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); 956 } 957 958 static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres) 959 { 960 BUG_ON((!(lockres->l_flags & OCFS2_LOCK_BUSY))); 961 BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED); 962 963 if (lockres->l_requested > DLM_LOCK_NL && 964 !(lockres->l_flags & OCFS2_LOCK_LOCAL) && 965 lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH) 966 lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH); 967 968 lockres->l_level = lockres->l_requested; 969 lockres_or_flags(lockres, OCFS2_LOCK_ATTACHED); 970 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); 971 } 972 973 static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres, 974 int level) 975 { 976 int needs_downconvert = 0; 977 978 assert_spin_locked(&lockres->l_lock); 979 980 if (level > lockres->l_blocking) { 981 /* only schedule a downconvert if we haven't already scheduled 982 * one that goes low enough to satisfy the level we're 983 * blocking. this also catches the case where we get 984 * duplicate BASTs */ 985 if (ocfs2_highest_compat_lock_level(level) < 986 ocfs2_highest_compat_lock_level(lockres->l_blocking)) 987 needs_downconvert = 1; 988 989 lockres->l_blocking = level; 990 } 991 992 mlog(ML_BASTS, "lockres %s, block %d, level %d, l_block %d, dwn %d\n", 993 lockres->l_name, level, lockres->l_level, lockres->l_blocking, 994 needs_downconvert); 995 996 if (needs_downconvert) 997 lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED); 998 mlog(0, "needs_downconvert = %d\n", needs_downconvert); 999 return needs_downconvert; 1000 } 1001 1002 /* 1003 * OCFS2_LOCK_PENDING and l_pending_gen. 1004 * 1005 * Why does OCFS2_LOCK_PENDING exist? To close a race between setting 1006 * OCFS2_LOCK_BUSY and calling ocfs2_dlm_lock(). See ocfs2_unblock_lock() 1007 * for more details on the race. 1008 * 1009 * OCFS2_LOCK_PENDING closes the race quite nicely. However, it introduces 1010 * a race on itself. In o2dlm, we can get the ast before ocfs2_dlm_lock() 1011 * returns. The ast clears OCFS2_LOCK_BUSY, and must therefore clear 1012 * OCFS2_LOCK_PENDING at the same time. When ocfs2_dlm_lock() returns, 1013 * the caller is going to try to clear PENDING again. If nothing else is 1014 * happening, __lockres_clear_pending() sees PENDING is unset and does 1015 * nothing. 1016 * 1017 * But what if another path (eg downconvert thread) has just started a 1018 * new locking action? The other path has re-set PENDING. Our path 1019 * cannot clear PENDING, because that will re-open the original race 1020 * window. 1021 * 1022 * [Example] 1023 * 1024 * ocfs2_meta_lock() 1025 * ocfs2_cluster_lock() 1026 * set BUSY 1027 * set PENDING 1028 * drop l_lock 1029 * ocfs2_dlm_lock() 1030 * ocfs2_locking_ast() ocfs2_downconvert_thread() 1031 * clear PENDING ocfs2_unblock_lock() 1032 * take_l_lock 1033 * !BUSY 1034 * ocfs2_prepare_downconvert() 1035 * set BUSY 1036 * set PENDING 1037 * drop l_lock 1038 * take l_lock 1039 * clear PENDING 1040 * drop l_lock 1041 * <window> 1042 * ocfs2_dlm_lock() 1043 * 1044 * So as you can see, we now have a window where l_lock is not held, 1045 * PENDING is not set, and ocfs2_dlm_lock() has not been called. 1046 * 1047 * The core problem is that ocfs2_cluster_lock() has cleared the PENDING 1048 * set by ocfs2_prepare_downconvert(). That wasn't nice. 1049 * 1050 * To solve this we introduce l_pending_gen. A call to 1051 * lockres_clear_pending() will only do so when it is passed a generation 1052 * number that matches the lockres. lockres_set_pending() will return the 1053 * current generation number. When ocfs2_cluster_lock() goes to clear 1054 * PENDING, it passes the generation it got from set_pending(). In our 1055 * example above, the generation numbers will *not* match. Thus, 1056 * ocfs2_cluster_lock() will not clear the PENDING set by 1057 * ocfs2_prepare_downconvert(). 1058 */ 1059 1060 /* Unlocked version for ocfs2_locking_ast() */ 1061 static void __lockres_clear_pending(struct ocfs2_lock_res *lockres, 1062 unsigned int generation, 1063 struct ocfs2_super *osb) 1064 { 1065 assert_spin_locked(&lockres->l_lock); 1066 1067 /* 1068 * The ast and locking functions can race us here. The winner 1069 * will clear pending, the loser will not. 1070 */ 1071 if (!(lockres->l_flags & OCFS2_LOCK_PENDING) || 1072 (lockres->l_pending_gen != generation)) 1073 return; 1074 1075 lockres_clear_flags(lockres, OCFS2_LOCK_PENDING); 1076 lockres->l_pending_gen++; 1077 1078 /* 1079 * The downconvert thread may have skipped us because we 1080 * were PENDING. Wake it up. 1081 */ 1082 if (lockres->l_flags & OCFS2_LOCK_BLOCKED) 1083 ocfs2_wake_downconvert_thread(osb); 1084 } 1085 1086 /* Locked version for callers of ocfs2_dlm_lock() */ 1087 static void lockres_clear_pending(struct ocfs2_lock_res *lockres, 1088 unsigned int generation, 1089 struct ocfs2_super *osb) 1090 { 1091 unsigned long flags; 1092 1093 spin_lock_irqsave(&lockres->l_lock, flags); 1094 __lockres_clear_pending(lockres, generation, osb); 1095 spin_unlock_irqrestore(&lockres->l_lock, flags); 1096 } 1097 1098 static unsigned int lockres_set_pending(struct ocfs2_lock_res *lockres) 1099 { 1100 assert_spin_locked(&lockres->l_lock); 1101 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY)); 1102 1103 lockres_or_flags(lockres, OCFS2_LOCK_PENDING); 1104 1105 return lockres->l_pending_gen; 1106 } 1107 1108 static void ocfs2_blocking_ast(struct ocfs2_dlm_lksb *lksb, int level) 1109 { 1110 struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb); 1111 struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres); 1112 int needs_downconvert; 1113 unsigned long flags; 1114 1115 BUG_ON(level <= DLM_LOCK_NL); 1116 1117 mlog(ML_BASTS, "BAST fired for lockres %s, blocking %d, level %d, " 1118 "type %s\n", lockres->l_name, level, lockres->l_level, 1119 ocfs2_lock_type_string(lockres->l_type)); 1120 1121 /* 1122 * We can skip the bast for locks which don't enable caching - 1123 * they'll be dropped at the earliest possible time anyway. 1124 */ 1125 if (lockres->l_flags & OCFS2_LOCK_NOCACHE) 1126 return; 1127 1128 spin_lock_irqsave(&lockres->l_lock, flags); 1129 needs_downconvert = ocfs2_generic_handle_bast(lockres, level); 1130 if (needs_downconvert) 1131 ocfs2_schedule_blocked_lock(osb, lockres); 1132 spin_unlock_irqrestore(&lockres->l_lock, flags); 1133 1134 wake_up(&lockres->l_event); 1135 1136 ocfs2_wake_downconvert_thread(osb); 1137 } 1138 1139 static void ocfs2_locking_ast(struct ocfs2_dlm_lksb *lksb) 1140 { 1141 struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb); 1142 struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres); 1143 unsigned long flags; 1144 int status; 1145 1146 spin_lock_irqsave(&lockres->l_lock, flags); 1147 1148 status = ocfs2_dlm_lock_status(&lockres->l_lksb); 1149 1150 if (status == -EAGAIN) { 1151 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); 1152 goto out; 1153 } 1154 1155 if (status) { 1156 mlog(ML_ERROR, "lockres %s: lksb status value of %d!\n", 1157 lockres->l_name, status); 1158 spin_unlock_irqrestore(&lockres->l_lock, flags); 1159 return; 1160 } 1161 1162 mlog(ML_BASTS, "AST fired for lockres %s, action %d, unlock %d, " 1163 "level %d => %d\n", lockres->l_name, lockres->l_action, 1164 lockres->l_unlock_action, lockres->l_level, lockres->l_requested); 1165 1166 switch(lockres->l_action) { 1167 case OCFS2_AST_ATTACH: 1168 ocfs2_generic_handle_attach_action(lockres); 1169 lockres_clear_flags(lockres, OCFS2_LOCK_LOCAL); 1170 break; 1171 case OCFS2_AST_CONVERT: 1172 ocfs2_generic_handle_convert_action(lockres); 1173 break; 1174 case OCFS2_AST_DOWNCONVERT: 1175 ocfs2_generic_handle_downconvert_action(lockres); 1176 break; 1177 default: 1178 mlog(ML_ERROR, "lockres %s: AST fired with invalid action: %u, " 1179 "flags 0x%lx, unlock: %u\n", 1180 lockres->l_name, lockres->l_action, lockres->l_flags, 1181 lockres->l_unlock_action); 1182 BUG(); 1183 } 1184 out: 1185 /* set it to something invalid so if we get called again we 1186 * can catch it. */ 1187 lockres->l_action = OCFS2_AST_INVALID; 1188 1189 /* Did we try to cancel this lock? Clear that state */ 1190 if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) 1191 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID; 1192 1193 /* 1194 * We may have beaten the locking functions here. We certainly 1195 * know that dlm_lock() has been called :-) 1196 * Because we can't have two lock calls in flight at once, we 1197 * can use lockres->l_pending_gen. 1198 */ 1199 __lockres_clear_pending(lockres, lockres->l_pending_gen, osb); 1200 1201 wake_up(&lockres->l_event); 1202 spin_unlock_irqrestore(&lockres->l_lock, flags); 1203 } 1204 1205 static void ocfs2_unlock_ast(struct ocfs2_dlm_lksb *lksb, int error) 1206 { 1207 struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb); 1208 unsigned long flags; 1209 1210 mlog(ML_BASTS, "UNLOCK AST fired for lockres %s, action = %d\n", 1211 lockres->l_name, lockres->l_unlock_action); 1212 1213 spin_lock_irqsave(&lockres->l_lock, flags); 1214 if (error) { 1215 mlog(ML_ERROR, "Dlm passes error %d for lock %s, " 1216 "unlock_action %d\n", error, lockres->l_name, 1217 lockres->l_unlock_action); 1218 spin_unlock_irqrestore(&lockres->l_lock, flags); 1219 return; 1220 } 1221 1222 switch(lockres->l_unlock_action) { 1223 case OCFS2_UNLOCK_CANCEL_CONVERT: 1224 mlog(0, "Cancel convert success for %s\n", lockres->l_name); 1225 lockres->l_action = OCFS2_AST_INVALID; 1226 /* Downconvert thread may have requeued this lock, we 1227 * need to wake it. */ 1228 if (lockres->l_flags & OCFS2_LOCK_BLOCKED) 1229 ocfs2_wake_downconvert_thread(ocfs2_get_lockres_osb(lockres)); 1230 break; 1231 case OCFS2_UNLOCK_DROP_LOCK: 1232 lockres->l_level = DLM_LOCK_IV; 1233 break; 1234 default: 1235 BUG(); 1236 } 1237 1238 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); 1239 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID; 1240 wake_up(&lockres->l_event); 1241 spin_unlock_irqrestore(&lockres->l_lock, flags); 1242 } 1243 1244 /* 1245 * This is the filesystem locking protocol. It provides the lock handling 1246 * hooks for the underlying DLM. It has a maximum version number. 1247 * The version number allows interoperability with systems running at 1248 * the same major number and an equal or smaller minor number. 1249 * 1250 * Whenever the filesystem does new things with locks (adds or removes a 1251 * lock, orders them differently, does different things underneath a lock), 1252 * the version must be changed. The protocol is negotiated when joining 1253 * the dlm domain. A node may join the domain if its major version is 1254 * identical to all other nodes and its minor version is greater than 1255 * or equal to all other nodes. When its minor version is greater than 1256 * the other nodes, it will run at the minor version specified by the 1257 * other nodes. 1258 * 1259 * If a locking change is made that will not be compatible with older 1260 * versions, the major number must be increased and the minor version set 1261 * to zero. If a change merely adds a behavior that can be disabled when 1262 * speaking to older versions, the minor version must be increased. If a 1263 * change adds a fully backwards compatible change (eg, LVB changes that 1264 * are just ignored by older versions), the version does not need to be 1265 * updated. 1266 */ 1267 static struct ocfs2_locking_protocol lproto = { 1268 .lp_max_version = { 1269 .pv_major = OCFS2_LOCKING_PROTOCOL_MAJOR, 1270 .pv_minor = OCFS2_LOCKING_PROTOCOL_MINOR, 1271 }, 1272 .lp_lock_ast = ocfs2_locking_ast, 1273 .lp_blocking_ast = ocfs2_blocking_ast, 1274 .lp_unlock_ast = ocfs2_unlock_ast, 1275 }; 1276 1277 void ocfs2_set_locking_protocol(void) 1278 { 1279 ocfs2_stack_glue_set_max_proto_version(&lproto.lp_max_version); 1280 } 1281 1282 static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres, 1283 int convert) 1284 { 1285 unsigned long flags; 1286 1287 spin_lock_irqsave(&lockres->l_lock, flags); 1288 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); 1289 lockres_clear_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING); 1290 if (convert) 1291 lockres->l_action = OCFS2_AST_INVALID; 1292 else 1293 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID; 1294 spin_unlock_irqrestore(&lockres->l_lock, flags); 1295 1296 wake_up(&lockres->l_event); 1297 } 1298 1299 /* Note: If we detect another process working on the lock (i.e., 1300 * OCFS2_LOCK_BUSY), we'll bail out returning 0. It's up to the caller 1301 * to do the right thing in that case. 1302 */ 1303 static int ocfs2_lock_create(struct ocfs2_super *osb, 1304 struct ocfs2_lock_res *lockres, 1305 int level, 1306 u32 dlm_flags) 1307 { 1308 int ret = 0; 1309 unsigned long flags; 1310 unsigned int gen; 1311 1312 mlog(0, "lock %s, level = %d, flags = %u\n", lockres->l_name, level, 1313 dlm_flags); 1314 1315 spin_lock_irqsave(&lockres->l_lock, flags); 1316 if ((lockres->l_flags & OCFS2_LOCK_ATTACHED) || 1317 (lockres->l_flags & OCFS2_LOCK_BUSY)) { 1318 spin_unlock_irqrestore(&lockres->l_lock, flags); 1319 goto bail; 1320 } 1321 1322 lockres->l_action = OCFS2_AST_ATTACH; 1323 lockres->l_requested = level; 1324 lockres_or_flags(lockres, OCFS2_LOCK_BUSY); 1325 gen = lockres_set_pending(lockres); 1326 spin_unlock_irqrestore(&lockres->l_lock, flags); 1327 1328 ret = ocfs2_dlm_lock(osb->cconn, 1329 level, 1330 &lockres->l_lksb, 1331 dlm_flags, 1332 lockres->l_name, 1333 OCFS2_LOCK_ID_MAX_LEN - 1); 1334 lockres_clear_pending(lockres, gen, osb); 1335 if (ret) { 1336 ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres); 1337 ocfs2_recover_from_dlm_error(lockres, 1); 1338 } 1339 1340 mlog(0, "lock %s, return from ocfs2_dlm_lock\n", lockres->l_name); 1341 1342 bail: 1343 return ret; 1344 } 1345 1346 static inline int ocfs2_check_wait_flag(struct ocfs2_lock_res *lockres, 1347 int flag) 1348 { 1349 unsigned long flags; 1350 int ret; 1351 1352 spin_lock_irqsave(&lockres->l_lock, flags); 1353 ret = lockres->l_flags & flag; 1354 spin_unlock_irqrestore(&lockres->l_lock, flags); 1355 1356 return ret; 1357 } 1358 1359 static inline void ocfs2_wait_on_busy_lock(struct ocfs2_lock_res *lockres) 1360 1361 { 1362 wait_event(lockres->l_event, 1363 !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_BUSY)); 1364 } 1365 1366 static inline void ocfs2_wait_on_refreshing_lock(struct ocfs2_lock_res *lockres) 1367 1368 { 1369 wait_event(lockres->l_event, 1370 !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_REFRESHING)); 1371 } 1372 1373 /* predict what lock level we'll be dropping down to on behalf 1374 * of another node, and return true if the currently wanted 1375 * level will be compatible with it. */ 1376 static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres, 1377 int wanted) 1378 { 1379 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED)); 1380 1381 return wanted <= ocfs2_highest_compat_lock_level(lockres->l_blocking); 1382 } 1383 1384 static void ocfs2_init_mask_waiter(struct ocfs2_mask_waiter *mw) 1385 { 1386 INIT_LIST_HEAD(&mw->mw_item); 1387 init_completion(&mw->mw_complete); 1388 ocfs2_init_start_time(mw); 1389 } 1390 1391 static int ocfs2_wait_for_mask(struct ocfs2_mask_waiter *mw) 1392 { 1393 wait_for_completion(&mw->mw_complete); 1394 /* Re-arm the completion in case we want to wait on it again */ 1395 reinit_completion(&mw->mw_complete); 1396 return mw->mw_status; 1397 } 1398 1399 static void lockres_add_mask_waiter(struct ocfs2_lock_res *lockres, 1400 struct ocfs2_mask_waiter *mw, 1401 unsigned long mask, 1402 unsigned long goal) 1403 { 1404 BUG_ON(!list_empty(&mw->mw_item)); 1405 1406 assert_spin_locked(&lockres->l_lock); 1407 1408 list_add_tail(&mw->mw_item, &lockres->l_mask_waiters); 1409 mw->mw_mask = mask; 1410 mw->mw_goal = goal; 1411 ocfs2_track_lock_wait(lockres); 1412 } 1413 1414 /* returns 0 if the mw that was removed was already satisfied, -EBUSY 1415 * if the mask still hadn't reached its goal */ 1416 static int __lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres, 1417 struct ocfs2_mask_waiter *mw) 1418 { 1419 int ret = 0; 1420 1421 assert_spin_locked(&lockres->l_lock); 1422 if (!list_empty(&mw->mw_item)) { 1423 if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal) 1424 ret = -EBUSY; 1425 1426 list_del_init(&mw->mw_item); 1427 init_completion(&mw->mw_complete); 1428 ocfs2_track_lock_wait(lockres); 1429 } 1430 1431 return ret; 1432 } 1433 1434 static int lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres, 1435 struct ocfs2_mask_waiter *mw) 1436 { 1437 unsigned long flags; 1438 int ret = 0; 1439 1440 spin_lock_irqsave(&lockres->l_lock, flags); 1441 ret = __lockres_remove_mask_waiter(lockres, mw); 1442 spin_unlock_irqrestore(&lockres->l_lock, flags); 1443 1444 return ret; 1445 1446 } 1447 1448 static int ocfs2_wait_for_mask_interruptible(struct ocfs2_mask_waiter *mw, 1449 struct ocfs2_lock_res *lockres) 1450 { 1451 int ret; 1452 1453 ret = wait_for_completion_interruptible(&mw->mw_complete); 1454 if (ret) 1455 lockres_remove_mask_waiter(lockres, mw); 1456 else 1457 ret = mw->mw_status; 1458 /* Re-arm the completion in case we want to wait on it again */ 1459 reinit_completion(&mw->mw_complete); 1460 return ret; 1461 } 1462 1463 static int __ocfs2_cluster_lock(struct ocfs2_super *osb, 1464 struct ocfs2_lock_res *lockres, 1465 int level, 1466 u32 lkm_flags, 1467 int arg_flags, 1468 int l_subclass, 1469 unsigned long caller_ip) 1470 { 1471 struct ocfs2_mask_waiter mw; 1472 int wait, catch_signals = !(osb->s_mount_opt & OCFS2_MOUNT_NOINTR); 1473 int ret = 0; /* gcc doesn't realize wait = 1 guarantees ret is set */ 1474 unsigned long flags; 1475 unsigned int gen; 1476 int noqueue_attempted = 0; 1477 int dlm_locked = 0; 1478 int kick_dc = 0; 1479 1480 if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED)) { 1481 mlog_errno(-EINVAL); 1482 return -EINVAL; 1483 } 1484 1485 ocfs2_init_mask_waiter(&mw); 1486 1487 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) 1488 lkm_flags |= DLM_LKF_VALBLK; 1489 1490 again: 1491 wait = 0; 1492 1493 spin_lock_irqsave(&lockres->l_lock, flags); 1494 1495 if (catch_signals && signal_pending(current)) { 1496 ret = -ERESTARTSYS; 1497 goto unlock; 1498 } 1499 1500 mlog_bug_on_msg(lockres->l_flags & OCFS2_LOCK_FREEING, 1501 "Cluster lock called on freeing lockres %s! flags " 1502 "0x%lx\n", lockres->l_name, lockres->l_flags); 1503 1504 /* We only compare against the currently granted level 1505 * here. If the lock is blocked waiting on a downconvert, 1506 * we'll get caught below. */ 1507 if (lockres->l_flags & OCFS2_LOCK_BUSY && 1508 level > lockres->l_level) { 1509 /* is someone sitting in dlm_lock? If so, wait on 1510 * them. */ 1511 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0); 1512 wait = 1; 1513 goto unlock; 1514 } 1515 1516 if (lockres->l_flags & OCFS2_LOCK_UPCONVERT_FINISHING) { 1517 /* 1518 * We've upconverted. If the lock now has a level we can 1519 * work with, we take it. If, however, the lock is not at the 1520 * required level, we go thru the full cycle. One way this could 1521 * happen is if a process requesting an upconvert to PR is 1522 * closely followed by another requesting upconvert to an EX. 1523 * If the process requesting EX lands here, we want it to 1524 * continue attempting to upconvert and let the process 1525 * requesting PR take the lock. 1526 * If multiple processes request upconvert to PR, the first one 1527 * here will take the lock. The others will have to go thru the 1528 * OCFS2_LOCK_BLOCKED check to ensure that there is no pending 1529 * downconvert request. 1530 */ 1531 if (level <= lockres->l_level) 1532 goto update_holders; 1533 } 1534 1535 if (lockres->l_flags & OCFS2_LOCK_BLOCKED && 1536 !ocfs2_may_continue_on_blocked_lock(lockres, level)) { 1537 /* is the lock is currently blocked on behalf of 1538 * another node */ 1539 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BLOCKED, 0); 1540 wait = 1; 1541 goto unlock; 1542 } 1543 1544 if (level > lockres->l_level) { 1545 if (noqueue_attempted > 0) { 1546 ret = -EAGAIN; 1547 goto unlock; 1548 } 1549 if (lkm_flags & DLM_LKF_NOQUEUE) 1550 noqueue_attempted = 1; 1551 1552 if (lockres->l_action != OCFS2_AST_INVALID) 1553 mlog(ML_ERROR, "lockres %s has action %u pending\n", 1554 lockres->l_name, lockres->l_action); 1555 1556 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) { 1557 lockres->l_action = OCFS2_AST_ATTACH; 1558 lkm_flags &= ~DLM_LKF_CONVERT; 1559 } else { 1560 lockres->l_action = OCFS2_AST_CONVERT; 1561 lkm_flags |= DLM_LKF_CONVERT; 1562 } 1563 1564 lockres->l_requested = level; 1565 lockres_or_flags(lockres, OCFS2_LOCK_BUSY); 1566 gen = lockres_set_pending(lockres); 1567 spin_unlock_irqrestore(&lockres->l_lock, flags); 1568 1569 BUG_ON(level == DLM_LOCK_IV); 1570 BUG_ON(level == DLM_LOCK_NL); 1571 1572 mlog(ML_BASTS, "lockres %s, convert from %d to %d\n", 1573 lockres->l_name, lockres->l_level, level); 1574 1575 /* call dlm_lock to upgrade lock now */ 1576 ret = ocfs2_dlm_lock(osb->cconn, 1577 level, 1578 &lockres->l_lksb, 1579 lkm_flags, 1580 lockres->l_name, 1581 OCFS2_LOCK_ID_MAX_LEN - 1); 1582 lockres_clear_pending(lockres, gen, osb); 1583 if (ret) { 1584 if (!(lkm_flags & DLM_LKF_NOQUEUE) || 1585 (ret != -EAGAIN)) { 1586 ocfs2_log_dlm_error("ocfs2_dlm_lock", 1587 ret, lockres); 1588 } 1589 ocfs2_recover_from_dlm_error(lockres, 1); 1590 goto out; 1591 } 1592 dlm_locked = 1; 1593 1594 mlog(0, "lock %s, successful return from ocfs2_dlm_lock\n", 1595 lockres->l_name); 1596 1597 /* At this point we've gone inside the dlm and need to 1598 * complete our work regardless. */ 1599 catch_signals = 0; 1600 1601 /* wait for busy to clear and carry on */ 1602 goto again; 1603 } 1604 1605 update_holders: 1606 /* Ok, if we get here then we're good to go. */ 1607 ocfs2_inc_holders(lockres, level); 1608 1609 ret = 0; 1610 unlock: 1611 lockres_clear_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING); 1612 1613 /* ocfs2_unblock_lock reques on seeing OCFS2_LOCK_UPCONVERT_FINISHING */ 1614 kick_dc = (lockres->l_flags & OCFS2_LOCK_BLOCKED); 1615 1616 spin_unlock_irqrestore(&lockres->l_lock, flags); 1617 if (kick_dc) 1618 ocfs2_wake_downconvert_thread(osb); 1619 out: 1620 /* 1621 * This is helping work around a lock inversion between the page lock 1622 * and dlm locks. One path holds the page lock while calling aops 1623 * which block acquiring dlm locks. The voting thread holds dlm 1624 * locks while acquiring page locks while down converting data locks. 1625 * This block is helping an aop path notice the inversion and back 1626 * off to unlock its page lock before trying the dlm lock again. 1627 */ 1628 if (wait && arg_flags & OCFS2_LOCK_NONBLOCK && 1629 mw.mw_mask & (OCFS2_LOCK_BUSY|OCFS2_LOCK_BLOCKED)) { 1630 wait = 0; 1631 spin_lock_irqsave(&lockres->l_lock, flags); 1632 if (__lockres_remove_mask_waiter(lockres, &mw)) { 1633 if (dlm_locked) 1634 lockres_or_flags(lockres, 1635 OCFS2_LOCK_NONBLOCK_FINISHED); 1636 spin_unlock_irqrestore(&lockres->l_lock, flags); 1637 ret = -EAGAIN; 1638 } else { 1639 spin_unlock_irqrestore(&lockres->l_lock, flags); 1640 goto again; 1641 } 1642 } 1643 if (wait) { 1644 ret = ocfs2_wait_for_mask(&mw); 1645 if (ret == 0) 1646 goto again; 1647 mlog_errno(ret); 1648 } 1649 ocfs2_update_lock_stats(lockres, level, &mw, ret); 1650 1651 #ifdef CONFIG_DEBUG_LOCK_ALLOC 1652 if (!ret && lockres->l_lockdep_map.key != NULL) { 1653 if (level == DLM_LOCK_PR) 1654 rwsem_acquire_read(&lockres->l_lockdep_map, l_subclass, 1655 !!(arg_flags & OCFS2_META_LOCK_NOQUEUE), 1656 caller_ip); 1657 else 1658 rwsem_acquire(&lockres->l_lockdep_map, l_subclass, 1659 !!(arg_flags & OCFS2_META_LOCK_NOQUEUE), 1660 caller_ip); 1661 } 1662 #endif 1663 return ret; 1664 } 1665 1666 static inline int ocfs2_cluster_lock(struct ocfs2_super *osb, 1667 struct ocfs2_lock_res *lockres, 1668 int level, 1669 u32 lkm_flags, 1670 int arg_flags) 1671 { 1672 return __ocfs2_cluster_lock(osb, lockres, level, lkm_flags, arg_flags, 1673 0, _RET_IP_); 1674 } 1675 1676 1677 static void __ocfs2_cluster_unlock(struct ocfs2_super *osb, 1678 struct ocfs2_lock_res *lockres, 1679 int level, 1680 unsigned long caller_ip) 1681 { 1682 unsigned long flags; 1683 1684 spin_lock_irqsave(&lockres->l_lock, flags); 1685 ocfs2_dec_holders(lockres, level); 1686 ocfs2_downconvert_on_unlock(osb, lockres); 1687 spin_unlock_irqrestore(&lockres->l_lock, flags); 1688 #ifdef CONFIG_DEBUG_LOCK_ALLOC 1689 if (lockres->l_lockdep_map.key != NULL) 1690 rwsem_release(&lockres->l_lockdep_map, 1, caller_ip); 1691 #endif 1692 } 1693 1694 static int ocfs2_create_new_lock(struct ocfs2_super *osb, 1695 struct ocfs2_lock_res *lockres, 1696 int ex, 1697 int local) 1698 { 1699 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 1700 unsigned long flags; 1701 u32 lkm_flags = local ? DLM_LKF_LOCAL : 0; 1702 1703 spin_lock_irqsave(&lockres->l_lock, flags); 1704 BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED); 1705 lockres_or_flags(lockres, OCFS2_LOCK_LOCAL); 1706 spin_unlock_irqrestore(&lockres->l_lock, flags); 1707 1708 return ocfs2_lock_create(osb, lockres, level, lkm_flags); 1709 } 1710 1711 /* Grants us an EX lock on the data and metadata resources, skipping 1712 * the normal cluster directory lookup. Use this ONLY on newly created 1713 * inodes which other nodes can't possibly see, and which haven't been 1714 * hashed in the inode hash yet. This can give us a good performance 1715 * increase as it'll skip the network broadcast normally associated 1716 * with creating a new lock resource. */ 1717 int ocfs2_create_new_inode_locks(struct inode *inode) 1718 { 1719 int ret; 1720 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1721 1722 BUG_ON(!ocfs2_inode_is_new(inode)); 1723 1724 mlog(0, "Inode %llu\n", (unsigned long long)OCFS2_I(inode)->ip_blkno); 1725 1726 /* NOTE: That we don't increment any of the holder counts, nor 1727 * do we add anything to a journal handle. Since this is 1728 * supposed to be a new inode which the cluster doesn't know 1729 * about yet, there is no need to. As far as the LVB handling 1730 * is concerned, this is basically like acquiring an EX lock 1731 * on a resource which has an invalid one -- we'll set it 1732 * valid when we release the EX. */ 1733 1734 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_rw_lockres, 1, 1); 1735 if (ret) { 1736 mlog_errno(ret); 1737 goto bail; 1738 } 1739 1740 /* 1741 * We don't want to use DLM_LKF_LOCAL on a meta data lock as they 1742 * don't use a generation in their lock names. 1743 */ 1744 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_inode_lockres, 1, 0); 1745 if (ret) { 1746 mlog_errno(ret); 1747 goto bail; 1748 } 1749 1750 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_open_lockres, 0, 0); 1751 if (ret) 1752 mlog_errno(ret); 1753 1754 bail: 1755 return ret; 1756 } 1757 1758 int ocfs2_rw_lock(struct inode *inode, int write) 1759 { 1760 int status, level; 1761 struct ocfs2_lock_res *lockres; 1762 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1763 1764 mlog(0, "inode %llu take %s RW lock\n", 1765 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1766 write ? "EXMODE" : "PRMODE"); 1767 1768 if (ocfs2_mount_local(osb)) 1769 return 0; 1770 1771 lockres = &OCFS2_I(inode)->ip_rw_lockres; 1772 1773 level = write ? DLM_LOCK_EX : DLM_LOCK_PR; 1774 1775 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0); 1776 if (status < 0) 1777 mlog_errno(status); 1778 1779 return status; 1780 } 1781 1782 int ocfs2_try_rw_lock(struct inode *inode, int write) 1783 { 1784 int status, level; 1785 struct ocfs2_lock_res *lockres; 1786 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1787 1788 mlog(0, "inode %llu try to take %s RW lock\n", 1789 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1790 write ? "EXMODE" : "PRMODE"); 1791 1792 if (ocfs2_mount_local(osb)) 1793 return 0; 1794 1795 lockres = &OCFS2_I(inode)->ip_rw_lockres; 1796 1797 level = write ? DLM_LOCK_EX : DLM_LOCK_PR; 1798 1799 status = ocfs2_cluster_lock(osb, lockres, level, DLM_LKF_NOQUEUE, 0); 1800 return status; 1801 } 1802 1803 void ocfs2_rw_unlock(struct inode *inode, int write) 1804 { 1805 int level = write ? DLM_LOCK_EX : DLM_LOCK_PR; 1806 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_rw_lockres; 1807 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1808 1809 mlog(0, "inode %llu drop %s RW lock\n", 1810 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1811 write ? "EXMODE" : "PRMODE"); 1812 1813 if (!ocfs2_mount_local(osb)) 1814 ocfs2_cluster_unlock(osb, lockres, level); 1815 } 1816 1817 /* 1818 * ocfs2_open_lock always get PR mode lock. 1819 */ 1820 int ocfs2_open_lock(struct inode *inode) 1821 { 1822 int status = 0; 1823 struct ocfs2_lock_res *lockres; 1824 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1825 1826 mlog(0, "inode %llu take PRMODE open lock\n", 1827 (unsigned long long)OCFS2_I(inode)->ip_blkno); 1828 1829 if (ocfs2_is_hard_readonly(osb) || ocfs2_mount_local(osb)) 1830 goto out; 1831 1832 lockres = &OCFS2_I(inode)->ip_open_lockres; 1833 1834 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_PR, 0, 0); 1835 if (status < 0) 1836 mlog_errno(status); 1837 1838 out: 1839 return status; 1840 } 1841 1842 int ocfs2_try_open_lock(struct inode *inode, int write) 1843 { 1844 int status = 0, level; 1845 struct ocfs2_lock_res *lockres; 1846 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1847 1848 mlog(0, "inode %llu try to take %s open lock\n", 1849 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1850 write ? "EXMODE" : "PRMODE"); 1851 1852 if (ocfs2_is_hard_readonly(osb)) { 1853 if (write) 1854 status = -EROFS; 1855 goto out; 1856 } 1857 1858 if (ocfs2_mount_local(osb)) 1859 goto out; 1860 1861 lockres = &OCFS2_I(inode)->ip_open_lockres; 1862 1863 level = write ? DLM_LOCK_EX : DLM_LOCK_PR; 1864 1865 /* 1866 * The file system may already holding a PRMODE/EXMODE open lock. 1867 * Since we pass DLM_LKF_NOQUEUE, the request won't block waiting on 1868 * other nodes and the -EAGAIN will indicate to the caller that 1869 * this inode is still in use. 1870 */ 1871 status = ocfs2_cluster_lock(osb, lockres, level, DLM_LKF_NOQUEUE, 0); 1872 1873 out: 1874 return status; 1875 } 1876 1877 /* 1878 * ocfs2_open_unlock unlock PR and EX mode open locks. 1879 */ 1880 void ocfs2_open_unlock(struct inode *inode) 1881 { 1882 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_open_lockres; 1883 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1884 1885 mlog(0, "inode %llu drop open lock\n", 1886 (unsigned long long)OCFS2_I(inode)->ip_blkno); 1887 1888 if (ocfs2_mount_local(osb)) 1889 goto out; 1890 1891 if(lockres->l_ro_holders) 1892 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_PR); 1893 if(lockres->l_ex_holders) 1894 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX); 1895 1896 out: 1897 return; 1898 } 1899 1900 static int ocfs2_flock_handle_signal(struct ocfs2_lock_res *lockres, 1901 int level) 1902 { 1903 int ret; 1904 struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres); 1905 unsigned long flags; 1906 struct ocfs2_mask_waiter mw; 1907 1908 ocfs2_init_mask_waiter(&mw); 1909 1910 retry_cancel: 1911 spin_lock_irqsave(&lockres->l_lock, flags); 1912 if (lockres->l_flags & OCFS2_LOCK_BUSY) { 1913 ret = ocfs2_prepare_cancel_convert(osb, lockres); 1914 if (ret) { 1915 spin_unlock_irqrestore(&lockres->l_lock, flags); 1916 ret = ocfs2_cancel_convert(osb, lockres); 1917 if (ret < 0) { 1918 mlog_errno(ret); 1919 goto out; 1920 } 1921 goto retry_cancel; 1922 } 1923 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0); 1924 spin_unlock_irqrestore(&lockres->l_lock, flags); 1925 1926 ocfs2_wait_for_mask(&mw); 1927 goto retry_cancel; 1928 } 1929 1930 ret = -ERESTARTSYS; 1931 /* 1932 * We may still have gotten the lock, in which case there's no 1933 * point to restarting the syscall. 1934 */ 1935 if (lockres->l_level == level) 1936 ret = 0; 1937 1938 mlog(0, "Cancel returning %d. flags: 0x%lx, level: %d, act: %d\n", ret, 1939 lockres->l_flags, lockres->l_level, lockres->l_action); 1940 1941 spin_unlock_irqrestore(&lockres->l_lock, flags); 1942 1943 out: 1944 return ret; 1945 } 1946 1947 /* 1948 * ocfs2_file_lock() and ocfs2_file_unlock() map to a single pair of 1949 * flock() calls. The locking approach this requires is sufficiently 1950 * different from all other cluster lock types that we implement a 1951 * separate path to the "low-level" dlm calls. In particular: 1952 * 1953 * - No optimization of lock levels is done - we take at exactly 1954 * what's been requested. 1955 * 1956 * - No lock caching is employed. We immediately downconvert to 1957 * no-lock at unlock time. This also means flock locks never go on 1958 * the blocking list). 1959 * 1960 * - Since userspace can trivially deadlock itself with flock, we make 1961 * sure to allow cancellation of a misbehaving applications flock() 1962 * request. 1963 * 1964 * - Access to any flock lockres doesn't require concurrency, so we 1965 * can simplify the code by requiring the caller to guarantee 1966 * serialization of dlmglue flock calls. 1967 */ 1968 int ocfs2_file_lock(struct file *file, int ex, int trylock) 1969 { 1970 int ret, level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 1971 unsigned int lkm_flags = trylock ? DLM_LKF_NOQUEUE : 0; 1972 unsigned long flags; 1973 struct ocfs2_file_private *fp = file->private_data; 1974 struct ocfs2_lock_res *lockres = &fp->fp_flock; 1975 struct ocfs2_super *osb = OCFS2_SB(file->f_mapping->host->i_sb); 1976 struct ocfs2_mask_waiter mw; 1977 1978 ocfs2_init_mask_waiter(&mw); 1979 1980 if ((lockres->l_flags & OCFS2_LOCK_BUSY) || 1981 (lockres->l_level > DLM_LOCK_NL)) { 1982 mlog(ML_ERROR, 1983 "File lock \"%s\" has busy or locked state: flags: 0x%lx, " 1984 "level: %u\n", lockres->l_name, lockres->l_flags, 1985 lockres->l_level); 1986 return -EINVAL; 1987 } 1988 1989 spin_lock_irqsave(&lockres->l_lock, flags); 1990 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) { 1991 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0); 1992 spin_unlock_irqrestore(&lockres->l_lock, flags); 1993 1994 /* 1995 * Get the lock at NLMODE to start - that way we 1996 * can cancel the upconvert request if need be. 1997 */ 1998 ret = ocfs2_lock_create(osb, lockres, DLM_LOCK_NL, 0); 1999 if (ret < 0) { 2000 mlog_errno(ret); 2001 goto out; 2002 } 2003 2004 ret = ocfs2_wait_for_mask(&mw); 2005 if (ret) { 2006 mlog_errno(ret); 2007 goto out; 2008 } 2009 spin_lock_irqsave(&lockres->l_lock, flags); 2010 } 2011 2012 lockres->l_action = OCFS2_AST_CONVERT; 2013 lkm_flags |= DLM_LKF_CONVERT; 2014 lockres->l_requested = level; 2015 lockres_or_flags(lockres, OCFS2_LOCK_BUSY); 2016 2017 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0); 2018 spin_unlock_irqrestore(&lockres->l_lock, flags); 2019 2020 ret = ocfs2_dlm_lock(osb->cconn, level, &lockres->l_lksb, lkm_flags, 2021 lockres->l_name, OCFS2_LOCK_ID_MAX_LEN - 1); 2022 if (ret) { 2023 if (!trylock || (ret != -EAGAIN)) { 2024 ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres); 2025 ret = -EINVAL; 2026 } 2027 2028 ocfs2_recover_from_dlm_error(lockres, 1); 2029 lockres_remove_mask_waiter(lockres, &mw); 2030 goto out; 2031 } 2032 2033 ret = ocfs2_wait_for_mask_interruptible(&mw, lockres); 2034 if (ret == -ERESTARTSYS) { 2035 /* 2036 * Userspace can cause deadlock itself with 2037 * flock(). Current behavior locally is to allow the 2038 * deadlock, but abort the system call if a signal is 2039 * received. We follow this example, otherwise a 2040 * poorly written program could sit in kernel until 2041 * reboot. 2042 * 2043 * Handling this is a bit more complicated for Ocfs2 2044 * though. We can't exit this function with an 2045 * outstanding lock request, so a cancel convert is 2046 * required. We intentionally overwrite 'ret' - if the 2047 * cancel fails and the lock was granted, it's easier 2048 * to just bubble success back up to the user. 2049 */ 2050 ret = ocfs2_flock_handle_signal(lockres, level); 2051 } else if (!ret && (level > lockres->l_level)) { 2052 /* Trylock failed asynchronously */ 2053 BUG_ON(!trylock); 2054 ret = -EAGAIN; 2055 } 2056 2057 out: 2058 2059 mlog(0, "Lock: \"%s\" ex: %d, trylock: %d, returns: %d\n", 2060 lockres->l_name, ex, trylock, ret); 2061 return ret; 2062 } 2063 2064 void ocfs2_file_unlock(struct file *file) 2065 { 2066 int ret; 2067 unsigned int gen; 2068 unsigned long flags; 2069 struct ocfs2_file_private *fp = file->private_data; 2070 struct ocfs2_lock_res *lockres = &fp->fp_flock; 2071 struct ocfs2_super *osb = OCFS2_SB(file->f_mapping->host->i_sb); 2072 struct ocfs2_mask_waiter mw; 2073 2074 ocfs2_init_mask_waiter(&mw); 2075 2076 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) 2077 return; 2078 2079 if (lockres->l_level == DLM_LOCK_NL) 2080 return; 2081 2082 mlog(0, "Unlock: \"%s\" flags: 0x%lx, level: %d, act: %d\n", 2083 lockres->l_name, lockres->l_flags, lockres->l_level, 2084 lockres->l_action); 2085 2086 spin_lock_irqsave(&lockres->l_lock, flags); 2087 /* 2088 * Fake a blocking ast for the downconvert code. 2089 */ 2090 lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED); 2091 lockres->l_blocking = DLM_LOCK_EX; 2092 2093 gen = ocfs2_prepare_downconvert(lockres, DLM_LOCK_NL); 2094 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0); 2095 spin_unlock_irqrestore(&lockres->l_lock, flags); 2096 2097 ret = ocfs2_downconvert_lock(osb, lockres, DLM_LOCK_NL, 0, gen); 2098 if (ret) { 2099 mlog_errno(ret); 2100 return; 2101 } 2102 2103 ret = ocfs2_wait_for_mask(&mw); 2104 if (ret) 2105 mlog_errno(ret); 2106 } 2107 2108 static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb, 2109 struct ocfs2_lock_res *lockres) 2110 { 2111 int kick = 0; 2112 2113 /* If we know that another node is waiting on our lock, kick 2114 * the downconvert thread * pre-emptively when we reach a release 2115 * condition. */ 2116 if (lockres->l_flags & OCFS2_LOCK_BLOCKED) { 2117 switch(lockres->l_blocking) { 2118 case DLM_LOCK_EX: 2119 if (!lockres->l_ex_holders && !lockres->l_ro_holders) 2120 kick = 1; 2121 break; 2122 case DLM_LOCK_PR: 2123 if (!lockres->l_ex_holders) 2124 kick = 1; 2125 break; 2126 default: 2127 BUG(); 2128 } 2129 } 2130 2131 if (kick) 2132 ocfs2_wake_downconvert_thread(osb); 2133 } 2134 2135 #define OCFS2_SEC_BITS 34 2136 #define OCFS2_SEC_SHIFT (64 - 34) 2137 #define OCFS2_NSEC_MASK ((1ULL << OCFS2_SEC_SHIFT) - 1) 2138 2139 /* LVB only has room for 64 bits of time here so we pack it for 2140 * now. */ 2141 static u64 ocfs2_pack_timespec(struct timespec64 *spec) 2142 { 2143 u64 res; 2144 u64 sec = clamp_t(time64_t, spec->tv_sec, 0, 0x3ffffffffull); 2145 u32 nsec = spec->tv_nsec; 2146 2147 res = (sec << OCFS2_SEC_SHIFT) | (nsec & OCFS2_NSEC_MASK); 2148 2149 return res; 2150 } 2151 2152 /* Call this with the lockres locked. I am reasonably sure we don't 2153 * need ip_lock in this function as anyone who would be changing those 2154 * values is supposed to be blocked in ocfs2_inode_lock right now. */ 2155 static void __ocfs2_stuff_meta_lvb(struct inode *inode) 2156 { 2157 struct ocfs2_inode_info *oi = OCFS2_I(inode); 2158 struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres; 2159 struct ocfs2_meta_lvb *lvb; 2160 2161 lvb = ocfs2_dlm_lvb(&lockres->l_lksb); 2162 2163 /* 2164 * Invalidate the LVB of a deleted inode - this way other 2165 * nodes are forced to go to disk and discover the new inode 2166 * status. 2167 */ 2168 if (oi->ip_flags & OCFS2_INODE_DELETED) { 2169 lvb->lvb_version = 0; 2170 goto out; 2171 } 2172 2173 lvb->lvb_version = OCFS2_LVB_VERSION; 2174 lvb->lvb_isize = cpu_to_be64(i_size_read(inode)); 2175 lvb->lvb_iclusters = cpu_to_be32(oi->ip_clusters); 2176 lvb->lvb_iuid = cpu_to_be32(i_uid_read(inode)); 2177 lvb->lvb_igid = cpu_to_be32(i_gid_read(inode)); 2178 lvb->lvb_imode = cpu_to_be16(inode->i_mode); 2179 lvb->lvb_inlink = cpu_to_be16(inode->i_nlink); 2180 lvb->lvb_iatime_packed = 2181 cpu_to_be64(ocfs2_pack_timespec(&inode->i_atime)); 2182 lvb->lvb_ictime_packed = 2183 cpu_to_be64(ocfs2_pack_timespec(&inode->i_ctime)); 2184 lvb->lvb_imtime_packed = 2185 cpu_to_be64(ocfs2_pack_timespec(&inode->i_mtime)); 2186 lvb->lvb_iattr = cpu_to_be32(oi->ip_attr); 2187 lvb->lvb_idynfeatures = cpu_to_be16(oi->ip_dyn_features); 2188 lvb->lvb_igeneration = cpu_to_be32(inode->i_generation); 2189 2190 out: 2191 mlog_meta_lvb(0, lockres); 2192 } 2193 2194 static void ocfs2_unpack_timespec(struct timespec64 *spec, 2195 u64 packed_time) 2196 { 2197 spec->tv_sec = packed_time >> OCFS2_SEC_SHIFT; 2198 spec->tv_nsec = packed_time & OCFS2_NSEC_MASK; 2199 } 2200 2201 static void ocfs2_refresh_inode_from_lvb(struct inode *inode) 2202 { 2203 struct ocfs2_inode_info *oi = OCFS2_I(inode); 2204 struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres; 2205 struct ocfs2_meta_lvb *lvb; 2206 2207 mlog_meta_lvb(0, lockres); 2208 2209 lvb = ocfs2_dlm_lvb(&lockres->l_lksb); 2210 2211 /* We're safe here without the lockres lock... */ 2212 spin_lock(&oi->ip_lock); 2213 oi->ip_clusters = be32_to_cpu(lvb->lvb_iclusters); 2214 i_size_write(inode, be64_to_cpu(lvb->lvb_isize)); 2215 2216 oi->ip_attr = be32_to_cpu(lvb->lvb_iattr); 2217 oi->ip_dyn_features = be16_to_cpu(lvb->lvb_idynfeatures); 2218 ocfs2_set_inode_flags(inode); 2219 2220 /* fast-symlinks are a special case */ 2221 if (S_ISLNK(inode->i_mode) && !oi->ip_clusters) 2222 inode->i_blocks = 0; 2223 else 2224 inode->i_blocks = ocfs2_inode_sector_count(inode); 2225 2226 i_uid_write(inode, be32_to_cpu(lvb->lvb_iuid)); 2227 i_gid_write(inode, be32_to_cpu(lvb->lvb_igid)); 2228 inode->i_mode = be16_to_cpu(lvb->lvb_imode); 2229 set_nlink(inode, be16_to_cpu(lvb->lvb_inlink)); 2230 ocfs2_unpack_timespec(&inode->i_atime, 2231 be64_to_cpu(lvb->lvb_iatime_packed)); 2232 ocfs2_unpack_timespec(&inode->i_mtime, 2233 be64_to_cpu(lvb->lvb_imtime_packed)); 2234 ocfs2_unpack_timespec(&inode->i_ctime, 2235 be64_to_cpu(lvb->lvb_ictime_packed)); 2236 spin_unlock(&oi->ip_lock); 2237 } 2238 2239 static inline int ocfs2_meta_lvb_is_trustable(struct inode *inode, 2240 struct ocfs2_lock_res *lockres) 2241 { 2242 struct ocfs2_meta_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb); 2243 2244 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) 2245 && lvb->lvb_version == OCFS2_LVB_VERSION 2246 && be32_to_cpu(lvb->lvb_igeneration) == inode->i_generation) 2247 return 1; 2248 return 0; 2249 } 2250 2251 /* Determine whether a lock resource needs to be refreshed, and 2252 * arbitrate who gets to refresh it. 2253 * 2254 * 0 means no refresh needed. 2255 * 2256 * > 0 means you need to refresh this and you MUST call 2257 * ocfs2_complete_lock_res_refresh afterwards. */ 2258 static int ocfs2_should_refresh_lock_res(struct ocfs2_lock_res *lockres) 2259 { 2260 unsigned long flags; 2261 int status = 0; 2262 2263 refresh_check: 2264 spin_lock_irqsave(&lockres->l_lock, flags); 2265 if (!(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) { 2266 spin_unlock_irqrestore(&lockres->l_lock, flags); 2267 goto bail; 2268 } 2269 2270 if (lockres->l_flags & OCFS2_LOCK_REFRESHING) { 2271 spin_unlock_irqrestore(&lockres->l_lock, flags); 2272 2273 ocfs2_wait_on_refreshing_lock(lockres); 2274 goto refresh_check; 2275 } 2276 2277 /* Ok, I'll be the one to refresh this lock. */ 2278 lockres_or_flags(lockres, OCFS2_LOCK_REFRESHING); 2279 spin_unlock_irqrestore(&lockres->l_lock, flags); 2280 2281 status = 1; 2282 bail: 2283 mlog(0, "status %d\n", status); 2284 return status; 2285 } 2286 2287 /* If status is non zero, I'll mark it as not being in refresh 2288 * anymroe, but i won't clear the needs refresh flag. */ 2289 static inline void ocfs2_complete_lock_res_refresh(struct ocfs2_lock_res *lockres, 2290 int status) 2291 { 2292 unsigned long flags; 2293 2294 spin_lock_irqsave(&lockres->l_lock, flags); 2295 lockres_clear_flags(lockres, OCFS2_LOCK_REFRESHING); 2296 if (!status) 2297 lockres_clear_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH); 2298 spin_unlock_irqrestore(&lockres->l_lock, flags); 2299 2300 wake_up(&lockres->l_event); 2301 } 2302 2303 /* may or may not return a bh if it went to disk. */ 2304 static int ocfs2_inode_lock_update(struct inode *inode, 2305 struct buffer_head **bh) 2306 { 2307 int status = 0; 2308 struct ocfs2_inode_info *oi = OCFS2_I(inode); 2309 struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres; 2310 struct ocfs2_dinode *fe; 2311 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 2312 2313 if (ocfs2_mount_local(osb)) 2314 goto bail; 2315 2316 spin_lock(&oi->ip_lock); 2317 if (oi->ip_flags & OCFS2_INODE_DELETED) { 2318 mlog(0, "Orphaned inode %llu was deleted while we " 2319 "were waiting on a lock. ip_flags = 0x%x\n", 2320 (unsigned long long)oi->ip_blkno, oi->ip_flags); 2321 spin_unlock(&oi->ip_lock); 2322 status = -ENOENT; 2323 goto bail; 2324 } 2325 spin_unlock(&oi->ip_lock); 2326 2327 if (!ocfs2_should_refresh_lock_res(lockres)) 2328 goto bail; 2329 2330 /* This will discard any caching information we might have had 2331 * for the inode metadata. */ 2332 ocfs2_metadata_cache_purge(INODE_CACHE(inode)); 2333 2334 ocfs2_extent_map_trunc(inode, 0); 2335 2336 if (ocfs2_meta_lvb_is_trustable(inode, lockres)) { 2337 mlog(0, "Trusting LVB on inode %llu\n", 2338 (unsigned long long)oi->ip_blkno); 2339 ocfs2_refresh_inode_from_lvb(inode); 2340 } else { 2341 /* Boo, we have to go to disk. */ 2342 /* read bh, cast, ocfs2_refresh_inode */ 2343 status = ocfs2_read_inode_block(inode, bh); 2344 if (status < 0) { 2345 mlog_errno(status); 2346 goto bail_refresh; 2347 } 2348 fe = (struct ocfs2_dinode *) (*bh)->b_data; 2349 2350 /* This is a good chance to make sure we're not 2351 * locking an invalid object. ocfs2_read_inode_block() 2352 * already checked that the inode block is sane. 2353 * 2354 * We bug on a stale inode here because we checked 2355 * above whether it was wiped from disk. The wiping 2356 * node provides a guarantee that we receive that 2357 * message and can mark the inode before dropping any 2358 * locks associated with it. */ 2359 mlog_bug_on_msg(inode->i_generation != 2360 le32_to_cpu(fe->i_generation), 2361 "Invalid dinode %llu disk generation: %u " 2362 "inode->i_generation: %u\n", 2363 (unsigned long long)oi->ip_blkno, 2364 le32_to_cpu(fe->i_generation), 2365 inode->i_generation); 2366 mlog_bug_on_msg(le64_to_cpu(fe->i_dtime) || 2367 !(fe->i_flags & cpu_to_le32(OCFS2_VALID_FL)), 2368 "Stale dinode %llu dtime: %llu flags: 0x%x\n", 2369 (unsigned long long)oi->ip_blkno, 2370 (unsigned long long)le64_to_cpu(fe->i_dtime), 2371 le32_to_cpu(fe->i_flags)); 2372 2373 ocfs2_refresh_inode(inode, fe); 2374 ocfs2_track_lock_refresh(lockres); 2375 } 2376 2377 status = 0; 2378 bail_refresh: 2379 ocfs2_complete_lock_res_refresh(lockres, status); 2380 bail: 2381 return status; 2382 } 2383 2384 static int ocfs2_assign_bh(struct inode *inode, 2385 struct buffer_head **ret_bh, 2386 struct buffer_head *passed_bh) 2387 { 2388 int status; 2389 2390 if (passed_bh) { 2391 /* Ok, the update went to disk for us, use the 2392 * returned bh. */ 2393 *ret_bh = passed_bh; 2394 get_bh(*ret_bh); 2395 2396 return 0; 2397 } 2398 2399 status = ocfs2_read_inode_block(inode, ret_bh); 2400 if (status < 0) 2401 mlog_errno(status); 2402 2403 return status; 2404 } 2405 2406 /* 2407 * returns < 0 error if the callback will never be called, otherwise 2408 * the result of the lock will be communicated via the callback. 2409 */ 2410 int ocfs2_inode_lock_full_nested(struct inode *inode, 2411 struct buffer_head **ret_bh, 2412 int ex, 2413 int arg_flags, 2414 int subclass) 2415 { 2416 int status, level, acquired; 2417 u32 dlm_flags; 2418 struct ocfs2_lock_res *lockres = NULL; 2419 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 2420 struct buffer_head *local_bh = NULL; 2421 2422 mlog(0, "inode %llu, take %s META lock\n", 2423 (unsigned long long)OCFS2_I(inode)->ip_blkno, 2424 ex ? "EXMODE" : "PRMODE"); 2425 2426 status = 0; 2427 acquired = 0; 2428 /* We'll allow faking a readonly metadata lock for 2429 * rodevices. */ 2430 if (ocfs2_is_hard_readonly(osb)) { 2431 if (ex) 2432 status = -EROFS; 2433 goto getbh; 2434 } 2435 2436 if ((arg_flags & OCFS2_META_LOCK_GETBH) || 2437 ocfs2_mount_local(osb)) 2438 goto update; 2439 2440 if (!(arg_flags & OCFS2_META_LOCK_RECOVERY)) 2441 ocfs2_wait_for_recovery(osb); 2442 2443 lockres = &OCFS2_I(inode)->ip_inode_lockres; 2444 level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 2445 dlm_flags = 0; 2446 if (arg_flags & OCFS2_META_LOCK_NOQUEUE) 2447 dlm_flags |= DLM_LKF_NOQUEUE; 2448 2449 status = __ocfs2_cluster_lock(osb, lockres, level, dlm_flags, 2450 arg_flags, subclass, _RET_IP_); 2451 if (status < 0) { 2452 if (status != -EAGAIN) 2453 mlog_errno(status); 2454 goto bail; 2455 } 2456 2457 /* Notify the error cleanup path to drop the cluster lock. */ 2458 acquired = 1; 2459 2460 /* We wait twice because a node may have died while we were in 2461 * the lower dlm layers. The second time though, we've 2462 * committed to owning this lock so we don't allow signals to 2463 * abort the operation. */ 2464 if (!(arg_flags & OCFS2_META_LOCK_RECOVERY)) 2465 ocfs2_wait_for_recovery(osb); 2466 2467 update: 2468 /* 2469 * We only see this flag if we're being called from 2470 * ocfs2_read_locked_inode(). It means we're locking an inode 2471 * which hasn't been populated yet, so clear the refresh flag 2472 * and let the caller handle it. 2473 */ 2474 if (inode->i_state & I_NEW) { 2475 status = 0; 2476 if (lockres) 2477 ocfs2_complete_lock_res_refresh(lockres, 0); 2478 goto bail; 2479 } 2480 2481 /* This is fun. The caller may want a bh back, or it may 2482 * not. ocfs2_inode_lock_update definitely wants one in, but 2483 * may or may not read one, depending on what's in the 2484 * LVB. The result of all of this is that we've *only* gone to 2485 * disk if we have to, so the complexity is worthwhile. */ 2486 status = ocfs2_inode_lock_update(inode, &local_bh); 2487 if (status < 0) { 2488 if (status != -ENOENT) 2489 mlog_errno(status); 2490 goto bail; 2491 } 2492 getbh: 2493 if (ret_bh) { 2494 status = ocfs2_assign_bh(inode, ret_bh, local_bh); 2495 if (status < 0) { 2496 mlog_errno(status); 2497 goto bail; 2498 } 2499 } 2500 2501 bail: 2502 if (status < 0) { 2503 if (ret_bh && (*ret_bh)) { 2504 brelse(*ret_bh); 2505 *ret_bh = NULL; 2506 } 2507 if (acquired) 2508 ocfs2_inode_unlock(inode, ex); 2509 } 2510 2511 brelse(local_bh); 2512 return status; 2513 } 2514 2515 /* 2516 * This is working around a lock inversion between tasks acquiring DLM 2517 * locks while holding a page lock and the downconvert thread which 2518 * blocks dlm lock acquiry while acquiring page locks. 2519 * 2520 * ** These _with_page variantes are only intended to be called from aop 2521 * methods that hold page locks and return a very specific *positive* error 2522 * code that aop methods pass up to the VFS -- test for errors with != 0. ** 2523 * 2524 * The DLM is called such that it returns -EAGAIN if it would have 2525 * blocked waiting for the downconvert thread. In that case we unlock 2526 * our page so the downconvert thread can make progress. Once we've 2527 * done this we have to return AOP_TRUNCATED_PAGE so the aop method 2528 * that called us can bubble that back up into the VFS who will then 2529 * immediately retry the aop call. 2530 */ 2531 int ocfs2_inode_lock_with_page(struct inode *inode, 2532 struct buffer_head **ret_bh, 2533 int ex, 2534 struct page *page) 2535 { 2536 int ret; 2537 2538 ret = ocfs2_inode_lock_full(inode, ret_bh, ex, OCFS2_LOCK_NONBLOCK); 2539 if (ret == -EAGAIN) { 2540 unlock_page(page); 2541 /* 2542 * If we can't get inode lock immediately, we should not return 2543 * directly here, since this will lead to a softlockup problem. 2544 * The method is to get a blocking lock and immediately unlock 2545 * before returning, this can avoid CPU resource waste due to 2546 * lots of retries, and benefits fairness in getting lock. 2547 */ 2548 if (ocfs2_inode_lock(inode, ret_bh, ex) == 0) 2549 ocfs2_inode_unlock(inode, ex); 2550 ret = AOP_TRUNCATED_PAGE; 2551 } 2552 2553 return ret; 2554 } 2555 2556 int ocfs2_inode_lock_atime(struct inode *inode, 2557 struct vfsmount *vfsmnt, 2558 int *level, int wait) 2559 { 2560 int ret; 2561 2562 if (wait) 2563 ret = ocfs2_inode_lock(inode, NULL, 0); 2564 else 2565 ret = ocfs2_try_inode_lock(inode, NULL, 0); 2566 2567 if (ret < 0) { 2568 if (ret != -EAGAIN) 2569 mlog_errno(ret); 2570 return ret; 2571 } 2572 2573 /* 2574 * If we should update atime, we will get EX lock, 2575 * otherwise we just get PR lock. 2576 */ 2577 if (ocfs2_should_update_atime(inode, vfsmnt)) { 2578 struct buffer_head *bh = NULL; 2579 2580 ocfs2_inode_unlock(inode, 0); 2581 if (wait) 2582 ret = ocfs2_inode_lock(inode, &bh, 1); 2583 else 2584 ret = ocfs2_try_inode_lock(inode, &bh, 1); 2585 2586 if (ret < 0) { 2587 if (ret != -EAGAIN) 2588 mlog_errno(ret); 2589 return ret; 2590 } 2591 *level = 1; 2592 if (ocfs2_should_update_atime(inode, vfsmnt)) 2593 ocfs2_update_inode_atime(inode, bh); 2594 brelse(bh); 2595 } else 2596 *level = 0; 2597 2598 return ret; 2599 } 2600 2601 void ocfs2_inode_unlock(struct inode *inode, 2602 int ex) 2603 { 2604 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 2605 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_inode_lockres; 2606 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 2607 2608 mlog(0, "inode %llu drop %s META lock\n", 2609 (unsigned long long)OCFS2_I(inode)->ip_blkno, 2610 ex ? "EXMODE" : "PRMODE"); 2611 2612 if (!ocfs2_is_hard_readonly(osb) && 2613 !ocfs2_mount_local(osb)) 2614 ocfs2_cluster_unlock(osb, lockres, level); 2615 } 2616 2617 /* 2618 * This _tracker variantes are introduced to deal with the recursive cluster 2619 * locking issue. The idea is to keep track of a lock holder on the stack of 2620 * the current process. If there's a lock holder on the stack, we know the 2621 * task context is already protected by cluster locking. Currently, they're 2622 * used in some VFS entry routines. 2623 * 2624 * return < 0 on error, return == 0 if there's no lock holder on the stack 2625 * before this call, return == 1 if this call would be a recursive locking. 2626 * return == -1 if this lock attempt will cause an upgrade which is forbidden. 2627 * 2628 * When taking lock levels into account,we face some different situations. 2629 * 2630 * 1. no lock is held 2631 * In this case, just lock the inode as requested and return 0 2632 * 2633 * 2. We are holding a lock 2634 * For this situation, things diverges into several cases 2635 * 2636 * wanted holding what to do 2637 * ex ex see 2.1 below 2638 * ex pr see 2.2 below 2639 * pr ex see 2.1 below 2640 * pr pr see 2.1 below 2641 * 2642 * 2.1 lock level that is been held is compatible 2643 * with the wanted level, so no lock action will be tacken. 2644 * 2645 * 2.2 Otherwise, an upgrade is needed, but it is forbidden. 2646 * 2647 * Reason why upgrade within a process is forbidden is that 2648 * lock upgrade may cause dead lock. The following illustrates 2649 * how it happens. 2650 * 2651 * thread on node1 thread on node2 2652 * ocfs2_inode_lock_tracker(ex=0) 2653 * 2654 * <====== ocfs2_inode_lock_tracker(ex=1) 2655 * 2656 * ocfs2_inode_lock_tracker(ex=1) 2657 */ 2658 int ocfs2_inode_lock_tracker(struct inode *inode, 2659 struct buffer_head **ret_bh, 2660 int ex, 2661 struct ocfs2_lock_holder *oh) 2662 { 2663 int status = 0; 2664 struct ocfs2_lock_res *lockres; 2665 struct ocfs2_lock_holder *tmp_oh; 2666 struct pid *pid = task_pid(current); 2667 2668 2669 lockres = &OCFS2_I(inode)->ip_inode_lockres; 2670 tmp_oh = ocfs2_pid_holder(lockres, pid); 2671 2672 if (!tmp_oh) { 2673 /* 2674 * This corresponds to the case 1. 2675 * We haven't got any lock before. 2676 */ 2677 status = ocfs2_inode_lock_full(inode, ret_bh, ex, 0); 2678 if (status < 0) { 2679 if (status != -ENOENT) 2680 mlog_errno(status); 2681 return status; 2682 } 2683 2684 oh->oh_ex = ex; 2685 ocfs2_add_holder(lockres, oh); 2686 return 0; 2687 } 2688 2689 if (unlikely(ex && !tmp_oh->oh_ex)) { 2690 /* 2691 * case 2.2 upgrade may cause dead lock, forbid it. 2692 */ 2693 mlog(ML_ERROR, "Recursive locking is not permitted to " 2694 "upgrade to EX level from PR level.\n"); 2695 dump_stack(); 2696 return -EINVAL; 2697 } 2698 2699 /* 2700 * case 2.1 OCFS2_META_LOCK_GETBH flag make ocfs2_inode_lock_full. 2701 * ignore the lock level and just update it. 2702 */ 2703 if (ret_bh) { 2704 status = ocfs2_inode_lock_full(inode, ret_bh, ex, 2705 OCFS2_META_LOCK_GETBH); 2706 if (status < 0) { 2707 if (status != -ENOENT) 2708 mlog_errno(status); 2709 return status; 2710 } 2711 } 2712 return tmp_oh ? 1 : 0; 2713 } 2714 2715 void ocfs2_inode_unlock_tracker(struct inode *inode, 2716 int ex, 2717 struct ocfs2_lock_holder *oh, 2718 int had_lock) 2719 { 2720 struct ocfs2_lock_res *lockres; 2721 2722 lockres = &OCFS2_I(inode)->ip_inode_lockres; 2723 /* had_lock means that the currect process already takes the cluster 2724 * lock previously. 2725 * If had_lock is 1, we have nothing to do here. 2726 * If had_lock is 0, we will release the lock. 2727 */ 2728 if (!had_lock) { 2729 ocfs2_inode_unlock(inode, oh->oh_ex); 2730 ocfs2_remove_holder(lockres, oh); 2731 } 2732 } 2733 2734 int ocfs2_orphan_scan_lock(struct ocfs2_super *osb, u32 *seqno) 2735 { 2736 struct ocfs2_lock_res *lockres; 2737 struct ocfs2_orphan_scan_lvb *lvb; 2738 int status = 0; 2739 2740 if (ocfs2_is_hard_readonly(osb)) 2741 return -EROFS; 2742 2743 if (ocfs2_mount_local(osb)) 2744 return 0; 2745 2746 lockres = &osb->osb_orphan_scan.os_lockres; 2747 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, 0, 0); 2748 if (status < 0) 2749 return status; 2750 2751 lvb = ocfs2_dlm_lvb(&lockres->l_lksb); 2752 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) && 2753 lvb->lvb_version == OCFS2_ORPHAN_LVB_VERSION) 2754 *seqno = be32_to_cpu(lvb->lvb_os_seqno); 2755 else 2756 *seqno = osb->osb_orphan_scan.os_seqno + 1; 2757 2758 return status; 2759 } 2760 2761 void ocfs2_orphan_scan_unlock(struct ocfs2_super *osb, u32 seqno) 2762 { 2763 struct ocfs2_lock_res *lockres; 2764 struct ocfs2_orphan_scan_lvb *lvb; 2765 2766 if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb)) { 2767 lockres = &osb->osb_orphan_scan.os_lockres; 2768 lvb = ocfs2_dlm_lvb(&lockres->l_lksb); 2769 lvb->lvb_version = OCFS2_ORPHAN_LVB_VERSION; 2770 lvb->lvb_os_seqno = cpu_to_be32(seqno); 2771 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX); 2772 } 2773 } 2774 2775 int ocfs2_super_lock(struct ocfs2_super *osb, 2776 int ex) 2777 { 2778 int status = 0; 2779 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 2780 struct ocfs2_lock_res *lockres = &osb->osb_super_lockres; 2781 2782 if (ocfs2_is_hard_readonly(osb)) 2783 return -EROFS; 2784 2785 if (ocfs2_mount_local(osb)) 2786 goto bail; 2787 2788 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0); 2789 if (status < 0) { 2790 mlog_errno(status); 2791 goto bail; 2792 } 2793 2794 /* The super block lock path is really in the best position to 2795 * know when resources covered by the lock need to be 2796 * refreshed, so we do it here. Of course, making sense of 2797 * everything is up to the caller :) */ 2798 status = ocfs2_should_refresh_lock_res(lockres); 2799 if (status) { 2800 status = ocfs2_refresh_slot_info(osb); 2801 2802 ocfs2_complete_lock_res_refresh(lockres, status); 2803 2804 if (status < 0) { 2805 ocfs2_cluster_unlock(osb, lockres, level); 2806 mlog_errno(status); 2807 } 2808 ocfs2_track_lock_refresh(lockres); 2809 } 2810 bail: 2811 return status; 2812 } 2813 2814 void ocfs2_super_unlock(struct ocfs2_super *osb, 2815 int ex) 2816 { 2817 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 2818 struct ocfs2_lock_res *lockres = &osb->osb_super_lockres; 2819 2820 if (!ocfs2_mount_local(osb)) 2821 ocfs2_cluster_unlock(osb, lockres, level); 2822 } 2823 2824 int ocfs2_rename_lock(struct ocfs2_super *osb) 2825 { 2826 int status; 2827 struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres; 2828 2829 if (ocfs2_is_hard_readonly(osb)) 2830 return -EROFS; 2831 2832 if (ocfs2_mount_local(osb)) 2833 return 0; 2834 2835 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, 0, 0); 2836 if (status < 0) 2837 mlog_errno(status); 2838 2839 return status; 2840 } 2841 2842 void ocfs2_rename_unlock(struct ocfs2_super *osb) 2843 { 2844 struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres; 2845 2846 if (!ocfs2_mount_local(osb)) 2847 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX); 2848 } 2849 2850 int ocfs2_nfs_sync_lock(struct ocfs2_super *osb, int ex) 2851 { 2852 int status; 2853 struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres; 2854 2855 if (ocfs2_is_hard_readonly(osb)) 2856 return -EROFS; 2857 2858 if (ocfs2_mount_local(osb)) 2859 return 0; 2860 2861 status = ocfs2_cluster_lock(osb, lockres, ex ? LKM_EXMODE : LKM_PRMODE, 2862 0, 0); 2863 if (status < 0) 2864 mlog(ML_ERROR, "lock on nfs sync lock failed %d\n", status); 2865 2866 return status; 2867 } 2868 2869 void ocfs2_nfs_sync_unlock(struct ocfs2_super *osb, int ex) 2870 { 2871 struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres; 2872 2873 if (!ocfs2_mount_local(osb)) 2874 ocfs2_cluster_unlock(osb, lockres, 2875 ex ? LKM_EXMODE : LKM_PRMODE); 2876 } 2877 2878 int ocfs2_trim_fs_lock(struct ocfs2_super *osb, 2879 struct ocfs2_trim_fs_info *info, int trylock) 2880 { 2881 int status; 2882 struct ocfs2_trim_fs_lvb *lvb; 2883 struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres; 2884 2885 if (info) 2886 info->tf_valid = 0; 2887 2888 if (ocfs2_is_hard_readonly(osb)) 2889 return -EROFS; 2890 2891 if (ocfs2_mount_local(osb)) 2892 return 0; 2893 2894 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, 2895 trylock ? DLM_LKF_NOQUEUE : 0, 0); 2896 if (status < 0) { 2897 if (status != -EAGAIN) 2898 mlog_errno(status); 2899 return status; 2900 } 2901 2902 if (info) { 2903 lvb = ocfs2_dlm_lvb(&lockres->l_lksb); 2904 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) && 2905 lvb->lvb_version == OCFS2_TRIMFS_LVB_VERSION) { 2906 info->tf_valid = 1; 2907 info->tf_success = lvb->lvb_success; 2908 info->tf_nodenum = be32_to_cpu(lvb->lvb_nodenum); 2909 info->tf_start = be64_to_cpu(lvb->lvb_start); 2910 info->tf_len = be64_to_cpu(lvb->lvb_len); 2911 info->tf_minlen = be64_to_cpu(lvb->lvb_minlen); 2912 info->tf_trimlen = be64_to_cpu(lvb->lvb_trimlen); 2913 } 2914 } 2915 2916 return status; 2917 } 2918 2919 void ocfs2_trim_fs_unlock(struct ocfs2_super *osb, 2920 struct ocfs2_trim_fs_info *info) 2921 { 2922 struct ocfs2_trim_fs_lvb *lvb; 2923 struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres; 2924 2925 if (ocfs2_mount_local(osb)) 2926 return; 2927 2928 if (info) { 2929 lvb = ocfs2_dlm_lvb(&lockres->l_lksb); 2930 lvb->lvb_version = OCFS2_TRIMFS_LVB_VERSION; 2931 lvb->lvb_success = info->tf_success; 2932 lvb->lvb_nodenum = cpu_to_be32(info->tf_nodenum); 2933 lvb->lvb_start = cpu_to_be64(info->tf_start); 2934 lvb->lvb_len = cpu_to_be64(info->tf_len); 2935 lvb->lvb_minlen = cpu_to_be64(info->tf_minlen); 2936 lvb->lvb_trimlen = cpu_to_be64(info->tf_trimlen); 2937 } 2938 2939 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX); 2940 } 2941 2942 int ocfs2_dentry_lock(struct dentry *dentry, int ex) 2943 { 2944 int ret; 2945 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 2946 struct ocfs2_dentry_lock *dl = dentry->d_fsdata; 2947 struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb); 2948 2949 BUG_ON(!dl); 2950 2951 if (ocfs2_is_hard_readonly(osb)) { 2952 if (ex) 2953 return -EROFS; 2954 return 0; 2955 } 2956 2957 if (ocfs2_mount_local(osb)) 2958 return 0; 2959 2960 ret = ocfs2_cluster_lock(osb, &dl->dl_lockres, level, 0, 0); 2961 if (ret < 0) 2962 mlog_errno(ret); 2963 2964 return ret; 2965 } 2966 2967 void ocfs2_dentry_unlock(struct dentry *dentry, int ex) 2968 { 2969 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 2970 struct ocfs2_dentry_lock *dl = dentry->d_fsdata; 2971 struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb); 2972 2973 if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb)) 2974 ocfs2_cluster_unlock(osb, &dl->dl_lockres, level); 2975 } 2976 2977 /* Reference counting of the dlm debug structure. We want this because 2978 * open references on the debug inodes can live on after a mount, so 2979 * we can't rely on the ocfs2_super to always exist. */ 2980 static void ocfs2_dlm_debug_free(struct kref *kref) 2981 { 2982 struct ocfs2_dlm_debug *dlm_debug; 2983 2984 dlm_debug = container_of(kref, struct ocfs2_dlm_debug, d_refcnt); 2985 2986 kfree(dlm_debug); 2987 } 2988 2989 void ocfs2_put_dlm_debug(struct ocfs2_dlm_debug *dlm_debug) 2990 { 2991 if (dlm_debug) 2992 kref_put(&dlm_debug->d_refcnt, ocfs2_dlm_debug_free); 2993 } 2994 2995 static void ocfs2_get_dlm_debug(struct ocfs2_dlm_debug *debug) 2996 { 2997 kref_get(&debug->d_refcnt); 2998 } 2999 3000 struct ocfs2_dlm_debug *ocfs2_new_dlm_debug(void) 3001 { 3002 struct ocfs2_dlm_debug *dlm_debug; 3003 3004 dlm_debug = kmalloc(sizeof(struct ocfs2_dlm_debug), GFP_KERNEL); 3005 if (!dlm_debug) { 3006 mlog_errno(-ENOMEM); 3007 goto out; 3008 } 3009 3010 kref_init(&dlm_debug->d_refcnt); 3011 INIT_LIST_HEAD(&dlm_debug->d_lockres_tracking); 3012 dlm_debug->d_filter_secs = 0; 3013 out: 3014 return dlm_debug; 3015 } 3016 3017 /* Access to this is arbitrated for us via seq_file->sem. */ 3018 struct ocfs2_dlm_seq_priv { 3019 struct ocfs2_dlm_debug *p_dlm_debug; 3020 struct ocfs2_lock_res p_iter_res; 3021 struct ocfs2_lock_res p_tmp_res; 3022 }; 3023 3024 static struct ocfs2_lock_res *ocfs2_dlm_next_res(struct ocfs2_lock_res *start, 3025 struct ocfs2_dlm_seq_priv *priv) 3026 { 3027 struct ocfs2_lock_res *iter, *ret = NULL; 3028 struct ocfs2_dlm_debug *dlm_debug = priv->p_dlm_debug; 3029 3030 assert_spin_locked(&ocfs2_dlm_tracking_lock); 3031 3032 list_for_each_entry(iter, &start->l_debug_list, l_debug_list) { 3033 /* discover the head of the list */ 3034 if (&iter->l_debug_list == &dlm_debug->d_lockres_tracking) { 3035 mlog(0, "End of list found, %p\n", ret); 3036 break; 3037 } 3038 3039 /* We track our "dummy" iteration lockres' by a NULL 3040 * l_ops field. */ 3041 if (iter->l_ops != NULL) { 3042 ret = iter; 3043 break; 3044 } 3045 } 3046 3047 return ret; 3048 } 3049 3050 static void *ocfs2_dlm_seq_start(struct seq_file *m, loff_t *pos) 3051 { 3052 struct ocfs2_dlm_seq_priv *priv = m->private; 3053 struct ocfs2_lock_res *iter; 3054 3055 spin_lock(&ocfs2_dlm_tracking_lock); 3056 iter = ocfs2_dlm_next_res(&priv->p_iter_res, priv); 3057 if (iter) { 3058 /* Since lockres' have the lifetime of their container 3059 * (which can be inodes, ocfs2_supers, etc) we want to 3060 * copy this out to a temporary lockres while still 3061 * under the spinlock. Obviously after this we can't 3062 * trust any pointers on the copy returned, but that's 3063 * ok as the information we want isn't typically held 3064 * in them. */ 3065 priv->p_tmp_res = *iter; 3066 iter = &priv->p_tmp_res; 3067 } 3068 spin_unlock(&ocfs2_dlm_tracking_lock); 3069 3070 return iter; 3071 } 3072 3073 static void ocfs2_dlm_seq_stop(struct seq_file *m, void *v) 3074 { 3075 } 3076 3077 static void *ocfs2_dlm_seq_next(struct seq_file *m, void *v, loff_t *pos) 3078 { 3079 struct ocfs2_dlm_seq_priv *priv = m->private; 3080 struct ocfs2_lock_res *iter = v; 3081 struct ocfs2_lock_res *dummy = &priv->p_iter_res; 3082 3083 spin_lock(&ocfs2_dlm_tracking_lock); 3084 iter = ocfs2_dlm_next_res(iter, priv); 3085 list_del_init(&dummy->l_debug_list); 3086 if (iter) { 3087 list_add(&dummy->l_debug_list, &iter->l_debug_list); 3088 priv->p_tmp_res = *iter; 3089 iter = &priv->p_tmp_res; 3090 } 3091 spin_unlock(&ocfs2_dlm_tracking_lock); 3092 3093 return iter; 3094 } 3095 3096 /* 3097 * Version is used by debugfs.ocfs2 to determine the format being used 3098 * 3099 * New in version 2 3100 * - Lock stats printed 3101 * New in version 3 3102 * - Max time in lock stats is in usecs (instead of nsecs) 3103 * New in version 4 3104 * - Add last pr/ex unlock times and first lock wait time in usecs 3105 */ 3106 #define OCFS2_DLM_DEBUG_STR_VERSION 4 3107 static int ocfs2_dlm_seq_show(struct seq_file *m, void *v) 3108 { 3109 int i; 3110 char *lvb; 3111 struct ocfs2_lock_res *lockres = v; 3112 #ifdef CONFIG_OCFS2_FS_STATS 3113 u64 now, last; 3114 struct ocfs2_dlm_debug *dlm_debug = 3115 ((struct ocfs2_dlm_seq_priv *)m->private)->p_dlm_debug; 3116 #endif 3117 3118 if (!lockres) 3119 return -EINVAL; 3120 3121 #ifdef CONFIG_OCFS2_FS_STATS 3122 if (!lockres->l_lock_wait && dlm_debug->d_filter_secs) { 3123 now = ktime_to_us(ktime_get_real()); 3124 if (lockres->l_lock_prmode.ls_last > 3125 lockres->l_lock_exmode.ls_last) 3126 last = lockres->l_lock_prmode.ls_last; 3127 else 3128 last = lockres->l_lock_exmode.ls_last; 3129 /* 3130 * Use d_filter_secs field to filter lock resources dump, 3131 * the default d_filter_secs(0) value filters nothing, 3132 * otherwise, only dump the last N seconds active lock 3133 * resources. 3134 */ 3135 if (div_u64(now - last, 1000000) > dlm_debug->d_filter_secs) 3136 return 0; 3137 } 3138 #endif 3139 3140 seq_printf(m, "0x%x\t", OCFS2_DLM_DEBUG_STR_VERSION); 3141 3142 if (lockres->l_type == OCFS2_LOCK_TYPE_DENTRY) 3143 seq_printf(m, "%.*s%08x\t", OCFS2_DENTRY_LOCK_INO_START - 1, 3144 lockres->l_name, 3145 (unsigned int)ocfs2_get_dentry_lock_ino(lockres)); 3146 else 3147 seq_printf(m, "%.*s\t", OCFS2_LOCK_ID_MAX_LEN, lockres->l_name); 3148 3149 seq_printf(m, "%d\t" 3150 "0x%lx\t" 3151 "0x%x\t" 3152 "0x%x\t" 3153 "%u\t" 3154 "%u\t" 3155 "%d\t" 3156 "%d\t", 3157 lockres->l_level, 3158 lockres->l_flags, 3159 lockres->l_action, 3160 lockres->l_unlock_action, 3161 lockres->l_ro_holders, 3162 lockres->l_ex_holders, 3163 lockres->l_requested, 3164 lockres->l_blocking); 3165 3166 /* Dump the raw LVB */ 3167 lvb = ocfs2_dlm_lvb(&lockres->l_lksb); 3168 for(i = 0; i < DLM_LVB_LEN; i++) 3169 seq_printf(m, "0x%x\t", lvb[i]); 3170 3171 #ifdef CONFIG_OCFS2_FS_STATS 3172 # define lock_num_prmode(_l) ((_l)->l_lock_prmode.ls_gets) 3173 # define lock_num_exmode(_l) ((_l)->l_lock_exmode.ls_gets) 3174 # define lock_num_prmode_failed(_l) ((_l)->l_lock_prmode.ls_fail) 3175 # define lock_num_exmode_failed(_l) ((_l)->l_lock_exmode.ls_fail) 3176 # define lock_total_prmode(_l) ((_l)->l_lock_prmode.ls_total) 3177 # define lock_total_exmode(_l) ((_l)->l_lock_exmode.ls_total) 3178 # define lock_max_prmode(_l) ((_l)->l_lock_prmode.ls_max) 3179 # define lock_max_exmode(_l) ((_l)->l_lock_exmode.ls_max) 3180 # define lock_refresh(_l) ((_l)->l_lock_refresh) 3181 # define lock_last_prmode(_l) ((_l)->l_lock_prmode.ls_last) 3182 # define lock_last_exmode(_l) ((_l)->l_lock_exmode.ls_last) 3183 # define lock_wait(_l) ((_l)->l_lock_wait) 3184 #else 3185 # define lock_num_prmode(_l) (0) 3186 # define lock_num_exmode(_l) (0) 3187 # define lock_num_prmode_failed(_l) (0) 3188 # define lock_num_exmode_failed(_l) (0) 3189 # define lock_total_prmode(_l) (0ULL) 3190 # define lock_total_exmode(_l) (0ULL) 3191 # define lock_max_prmode(_l) (0) 3192 # define lock_max_exmode(_l) (0) 3193 # define lock_refresh(_l) (0) 3194 # define lock_last_prmode(_l) (0ULL) 3195 # define lock_last_exmode(_l) (0ULL) 3196 # define lock_wait(_l) (0ULL) 3197 #endif 3198 /* The following seq_print was added in version 2 of this output */ 3199 seq_printf(m, "%u\t" 3200 "%u\t" 3201 "%u\t" 3202 "%u\t" 3203 "%llu\t" 3204 "%llu\t" 3205 "%u\t" 3206 "%u\t" 3207 "%u\t" 3208 "%llu\t" 3209 "%llu\t" 3210 "%llu\t", 3211 lock_num_prmode(lockres), 3212 lock_num_exmode(lockres), 3213 lock_num_prmode_failed(lockres), 3214 lock_num_exmode_failed(lockres), 3215 lock_total_prmode(lockres), 3216 lock_total_exmode(lockres), 3217 lock_max_prmode(lockres), 3218 lock_max_exmode(lockres), 3219 lock_refresh(lockres), 3220 lock_last_prmode(lockres), 3221 lock_last_exmode(lockres), 3222 lock_wait(lockres)); 3223 3224 /* End the line */ 3225 seq_printf(m, "\n"); 3226 return 0; 3227 } 3228 3229 static const struct seq_operations ocfs2_dlm_seq_ops = { 3230 .start = ocfs2_dlm_seq_start, 3231 .stop = ocfs2_dlm_seq_stop, 3232 .next = ocfs2_dlm_seq_next, 3233 .show = ocfs2_dlm_seq_show, 3234 }; 3235 3236 static int ocfs2_dlm_debug_release(struct inode *inode, struct file *file) 3237 { 3238 struct seq_file *seq = file->private_data; 3239 struct ocfs2_dlm_seq_priv *priv = seq->private; 3240 struct ocfs2_lock_res *res = &priv->p_iter_res; 3241 3242 ocfs2_remove_lockres_tracking(res); 3243 ocfs2_put_dlm_debug(priv->p_dlm_debug); 3244 return seq_release_private(inode, file); 3245 } 3246 3247 static int ocfs2_dlm_debug_open(struct inode *inode, struct file *file) 3248 { 3249 struct ocfs2_dlm_seq_priv *priv; 3250 struct ocfs2_super *osb; 3251 3252 priv = __seq_open_private(file, &ocfs2_dlm_seq_ops, sizeof(*priv)); 3253 if (!priv) { 3254 mlog_errno(-ENOMEM); 3255 return -ENOMEM; 3256 } 3257 3258 osb = inode->i_private; 3259 ocfs2_get_dlm_debug(osb->osb_dlm_debug); 3260 priv->p_dlm_debug = osb->osb_dlm_debug; 3261 INIT_LIST_HEAD(&priv->p_iter_res.l_debug_list); 3262 3263 ocfs2_add_lockres_tracking(&priv->p_iter_res, 3264 priv->p_dlm_debug); 3265 3266 return 0; 3267 } 3268 3269 static const struct file_operations ocfs2_dlm_debug_fops = { 3270 .open = ocfs2_dlm_debug_open, 3271 .release = ocfs2_dlm_debug_release, 3272 .read = seq_read, 3273 .llseek = seq_lseek, 3274 }; 3275 3276 static void ocfs2_dlm_init_debug(struct ocfs2_super *osb) 3277 { 3278 struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug; 3279 3280 debugfs_create_file("locking_state", S_IFREG|S_IRUSR, 3281 osb->osb_debug_root, osb, &ocfs2_dlm_debug_fops); 3282 3283 debugfs_create_u32("locking_filter", 0600, osb->osb_debug_root, 3284 &dlm_debug->d_filter_secs); 3285 } 3286 3287 static void ocfs2_dlm_shutdown_debug(struct ocfs2_super *osb) 3288 { 3289 struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug; 3290 3291 if (dlm_debug) 3292 ocfs2_put_dlm_debug(dlm_debug); 3293 } 3294 3295 int ocfs2_dlm_init(struct ocfs2_super *osb) 3296 { 3297 int status = 0; 3298 struct ocfs2_cluster_connection *conn = NULL; 3299 3300 if (ocfs2_mount_local(osb)) { 3301 osb->node_num = 0; 3302 goto local; 3303 } 3304 3305 ocfs2_dlm_init_debug(osb); 3306 3307 /* launch downconvert thread */ 3308 osb->dc_task = kthread_run(ocfs2_downconvert_thread, osb, "ocfs2dc-%s", 3309 osb->uuid_str); 3310 if (IS_ERR(osb->dc_task)) { 3311 status = PTR_ERR(osb->dc_task); 3312 osb->dc_task = NULL; 3313 mlog_errno(status); 3314 goto bail; 3315 } 3316 3317 /* for now, uuid == domain */ 3318 status = ocfs2_cluster_connect(osb->osb_cluster_stack, 3319 osb->osb_cluster_name, 3320 strlen(osb->osb_cluster_name), 3321 osb->uuid_str, 3322 strlen(osb->uuid_str), 3323 &lproto, ocfs2_do_node_down, osb, 3324 &conn); 3325 if (status) { 3326 mlog_errno(status); 3327 goto bail; 3328 } 3329 3330 status = ocfs2_cluster_this_node(conn, &osb->node_num); 3331 if (status < 0) { 3332 mlog_errno(status); 3333 mlog(ML_ERROR, 3334 "could not find this host's node number\n"); 3335 ocfs2_cluster_disconnect(conn, 0); 3336 goto bail; 3337 } 3338 3339 local: 3340 ocfs2_super_lock_res_init(&osb->osb_super_lockres, osb); 3341 ocfs2_rename_lock_res_init(&osb->osb_rename_lockres, osb); 3342 ocfs2_nfs_sync_lock_res_init(&osb->osb_nfs_sync_lockres, osb); 3343 ocfs2_orphan_scan_lock_res_init(&osb->osb_orphan_scan.os_lockres, osb); 3344 3345 osb->cconn = conn; 3346 bail: 3347 if (status < 0) { 3348 ocfs2_dlm_shutdown_debug(osb); 3349 if (osb->dc_task) 3350 kthread_stop(osb->dc_task); 3351 } 3352 3353 return status; 3354 } 3355 3356 void ocfs2_dlm_shutdown(struct ocfs2_super *osb, 3357 int hangup_pending) 3358 { 3359 ocfs2_drop_osb_locks(osb); 3360 3361 /* 3362 * Now that we have dropped all locks and ocfs2_dismount_volume() 3363 * has disabled recovery, the DLM won't be talking to us. It's 3364 * safe to tear things down before disconnecting the cluster. 3365 */ 3366 3367 if (osb->dc_task) { 3368 kthread_stop(osb->dc_task); 3369 osb->dc_task = NULL; 3370 } 3371 3372 ocfs2_lock_res_free(&osb->osb_super_lockres); 3373 ocfs2_lock_res_free(&osb->osb_rename_lockres); 3374 ocfs2_lock_res_free(&osb->osb_nfs_sync_lockres); 3375 ocfs2_lock_res_free(&osb->osb_orphan_scan.os_lockres); 3376 3377 ocfs2_cluster_disconnect(osb->cconn, hangup_pending); 3378 osb->cconn = NULL; 3379 3380 ocfs2_dlm_shutdown_debug(osb); 3381 } 3382 3383 static int ocfs2_drop_lock(struct ocfs2_super *osb, 3384 struct ocfs2_lock_res *lockres) 3385 { 3386 int ret; 3387 unsigned long flags; 3388 u32 lkm_flags = 0; 3389 3390 /* We didn't get anywhere near actually using this lockres. */ 3391 if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED)) 3392 goto out; 3393 3394 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) 3395 lkm_flags |= DLM_LKF_VALBLK; 3396 3397 spin_lock_irqsave(&lockres->l_lock, flags); 3398 3399 mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_FREEING), 3400 "lockres %s, flags 0x%lx\n", 3401 lockres->l_name, lockres->l_flags); 3402 3403 while (lockres->l_flags & OCFS2_LOCK_BUSY) { 3404 mlog(0, "waiting on busy lock \"%s\": flags = %lx, action = " 3405 "%u, unlock_action = %u\n", 3406 lockres->l_name, lockres->l_flags, lockres->l_action, 3407 lockres->l_unlock_action); 3408 3409 spin_unlock_irqrestore(&lockres->l_lock, flags); 3410 3411 /* XXX: Today we just wait on any busy 3412 * locks... Perhaps we need to cancel converts in the 3413 * future? */ 3414 ocfs2_wait_on_busy_lock(lockres); 3415 3416 spin_lock_irqsave(&lockres->l_lock, flags); 3417 } 3418 3419 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) { 3420 if (lockres->l_flags & OCFS2_LOCK_ATTACHED && 3421 lockres->l_level == DLM_LOCK_EX && 3422 !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) 3423 lockres->l_ops->set_lvb(lockres); 3424 } 3425 3426 if (lockres->l_flags & OCFS2_LOCK_BUSY) 3427 mlog(ML_ERROR, "destroying busy lock: \"%s\"\n", 3428 lockres->l_name); 3429 if (lockres->l_flags & OCFS2_LOCK_BLOCKED) 3430 mlog(0, "destroying blocked lock: \"%s\"\n", lockres->l_name); 3431 3432 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) { 3433 spin_unlock_irqrestore(&lockres->l_lock, flags); 3434 goto out; 3435 } 3436 3437 lockres_clear_flags(lockres, OCFS2_LOCK_ATTACHED); 3438 3439 /* make sure we never get here while waiting for an ast to 3440 * fire. */ 3441 BUG_ON(lockres->l_action != OCFS2_AST_INVALID); 3442 3443 /* is this necessary? */ 3444 lockres_or_flags(lockres, OCFS2_LOCK_BUSY); 3445 lockres->l_unlock_action = OCFS2_UNLOCK_DROP_LOCK; 3446 spin_unlock_irqrestore(&lockres->l_lock, flags); 3447 3448 mlog(0, "lock %s\n", lockres->l_name); 3449 3450 ret = ocfs2_dlm_unlock(osb->cconn, &lockres->l_lksb, lkm_flags); 3451 if (ret) { 3452 ocfs2_log_dlm_error("ocfs2_dlm_unlock", ret, lockres); 3453 mlog(ML_ERROR, "lockres flags: %lu\n", lockres->l_flags); 3454 ocfs2_dlm_dump_lksb(&lockres->l_lksb); 3455 BUG(); 3456 } 3457 mlog(0, "lock %s, successful return from ocfs2_dlm_unlock\n", 3458 lockres->l_name); 3459 3460 ocfs2_wait_on_busy_lock(lockres); 3461 out: 3462 return 0; 3463 } 3464 3465 static void ocfs2_process_blocked_lock(struct ocfs2_super *osb, 3466 struct ocfs2_lock_res *lockres); 3467 3468 /* Mark the lockres as being dropped. It will no longer be 3469 * queued if blocking, but we still may have to wait on it 3470 * being dequeued from the downconvert thread before we can consider 3471 * it safe to drop. 3472 * 3473 * You can *not* attempt to call cluster_lock on this lockres anymore. */ 3474 void ocfs2_mark_lockres_freeing(struct ocfs2_super *osb, 3475 struct ocfs2_lock_res *lockres) 3476 { 3477 int status; 3478 struct ocfs2_mask_waiter mw; 3479 unsigned long flags, flags2; 3480 3481 ocfs2_init_mask_waiter(&mw); 3482 3483 spin_lock_irqsave(&lockres->l_lock, flags); 3484 lockres->l_flags |= OCFS2_LOCK_FREEING; 3485 if (lockres->l_flags & OCFS2_LOCK_QUEUED && current == osb->dc_task) { 3486 /* 3487 * We know the downconvert is queued but not in progress 3488 * because we are the downconvert thread and processing 3489 * different lock. So we can just remove the lock from the 3490 * queue. This is not only an optimization but also a way 3491 * to avoid the following deadlock: 3492 * ocfs2_dentry_post_unlock() 3493 * ocfs2_dentry_lock_put() 3494 * ocfs2_drop_dentry_lock() 3495 * iput() 3496 * ocfs2_evict_inode() 3497 * ocfs2_clear_inode() 3498 * ocfs2_mark_lockres_freeing() 3499 * ... blocks waiting for OCFS2_LOCK_QUEUED 3500 * since we are the downconvert thread which 3501 * should clear the flag. 3502 */ 3503 spin_unlock_irqrestore(&lockres->l_lock, flags); 3504 spin_lock_irqsave(&osb->dc_task_lock, flags2); 3505 list_del_init(&lockres->l_blocked_list); 3506 osb->blocked_lock_count--; 3507 spin_unlock_irqrestore(&osb->dc_task_lock, flags2); 3508 /* 3509 * Warn if we recurse into another post_unlock call. Strictly 3510 * speaking it isn't a problem but we need to be careful if 3511 * that happens (stack overflow, deadlocks, ...) so warn if 3512 * ocfs2 grows a path for which this can happen. 3513 */ 3514 WARN_ON_ONCE(lockres->l_ops->post_unlock); 3515 /* Since the lock is freeing we don't do much in the fn below */ 3516 ocfs2_process_blocked_lock(osb, lockres); 3517 return; 3518 } 3519 while (lockres->l_flags & OCFS2_LOCK_QUEUED) { 3520 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_QUEUED, 0); 3521 spin_unlock_irqrestore(&lockres->l_lock, flags); 3522 3523 mlog(0, "Waiting on lockres %s\n", lockres->l_name); 3524 3525 status = ocfs2_wait_for_mask(&mw); 3526 if (status) 3527 mlog_errno(status); 3528 3529 spin_lock_irqsave(&lockres->l_lock, flags); 3530 } 3531 spin_unlock_irqrestore(&lockres->l_lock, flags); 3532 } 3533 3534 void ocfs2_simple_drop_lockres(struct ocfs2_super *osb, 3535 struct ocfs2_lock_res *lockres) 3536 { 3537 int ret; 3538 3539 ocfs2_mark_lockres_freeing(osb, lockres); 3540 ret = ocfs2_drop_lock(osb, lockres); 3541 if (ret) 3542 mlog_errno(ret); 3543 } 3544 3545 static void ocfs2_drop_osb_locks(struct ocfs2_super *osb) 3546 { 3547 ocfs2_simple_drop_lockres(osb, &osb->osb_super_lockres); 3548 ocfs2_simple_drop_lockres(osb, &osb->osb_rename_lockres); 3549 ocfs2_simple_drop_lockres(osb, &osb->osb_nfs_sync_lockres); 3550 ocfs2_simple_drop_lockres(osb, &osb->osb_orphan_scan.os_lockres); 3551 } 3552 3553 int ocfs2_drop_inode_locks(struct inode *inode) 3554 { 3555 int status, err; 3556 3557 /* No need to call ocfs2_mark_lockres_freeing here - 3558 * ocfs2_clear_inode has done it for us. */ 3559 3560 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb), 3561 &OCFS2_I(inode)->ip_open_lockres); 3562 if (err < 0) 3563 mlog_errno(err); 3564 3565 status = err; 3566 3567 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb), 3568 &OCFS2_I(inode)->ip_inode_lockres); 3569 if (err < 0) 3570 mlog_errno(err); 3571 if (err < 0 && !status) 3572 status = err; 3573 3574 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb), 3575 &OCFS2_I(inode)->ip_rw_lockres); 3576 if (err < 0) 3577 mlog_errno(err); 3578 if (err < 0 && !status) 3579 status = err; 3580 3581 return status; 3582 } 3583 3584 static unsigned int ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres, 3585 int new_level) 3586 { 3587 assert_spin_locked(&lockres->l_lock); 3588 3589 BUG_ON(lockres->l_blocking <= DLM_LOCK_NL); 3590 3591 if (lockres->l_level <= new_level) { 3592 mlog(ML_ERROR, "lockres %s, lvl %d <= %d, blcklst %d, mask %d, " 3593 "type %d, flags 0x%lx, hold %d %d, act %d %d, req %d, " 3594 "block %d, pgen %d\n", lockres->l_name, lockres->l_level, 3595 new_level, list_empty(&lockres->l_blocked_list), 3596 list_empty(&lockres->l_mask_waiters), lockres->l_type, 3597 lockres->l_flags, lockres->l_ro_holders, 3598 lockres->l_ex_holders, lockres->l_action, 3599 lockres->l_unlock_action, lockres->l_requested, 3600 lockres->l_blocking, lockres->l_pending_gen); 3601 BUG(); 3602 } 3603 3604 mlog(ML_BASTS, "lockres %s, level %d => %d, blocking %d\n", 3605 lockres->l_name, lockres->l_level, new_level, lockres->l_blocking); 3606 3607 lockres->l_action = OCFS2_AST_DOWNCONVERT; 3608 lockres->l_requested = new_level; 3609 lockres_or_flags(lockres, OCFS2_LOCK_BUSY); 3610 return lockres_set_pending(lockres); 3611 } 3612 3613 static int ocfs2_downconvert_lock(struct ocfs2_super *osb, 3614 struct ocfs2_lock_res *lockres, 3615 int new_level, 3616 int lvb, 3617 unsigned int generation) 3618 { 3619 int ret; 3620 u32 dlm_flags = DLM_LKF_CONVERT; 3621 3622 mlog(ML_BASTS, "lockres %s, level %d => %d\n", lockres->l_name, 3623 lockres->l_level, new_level); 3624 3625 /* 3626 * On DLM_LKF_VALBLK, fsdlm behaves differently with o2cb. It always 3627 * expects DLM_LKF_VALBLK being set if the LKB has LVB, so that 3628 * we can recover correctly from node failure. Otherwise, we may get 3629 * invalid LVB in LKB, but without DLM_SBF_VALNOTVALID being set. 3630 */ 3631 if (ocfs2_userspace_stack(osb) && 3632 lockres->l_ops->flags & LOCK_TYPE_USES_LVB) 3633 lvb = 1; 3634 3635 if (lvb) 3636 dlm_flags |= DLM_LKF_VALBLK; 3637 3638 ret = ocfs2_dlm_lock(osb->cconn, 3639 new_level, 3640 &lockres->l_lksb, 3641 dlm_flags, 3642 lockres->l_name, 3643 OCFS2_LOCK_ID_MAX_LEN - 1); 3644 lockres_clear_pending(lockres, generation, osb); 3645 if (ret) { 3646 ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres); 3647 ocfs2_recover_from_dlm_error(lockres, 1); 3648 goto bail; 3649 } 3650 3651 ret = 0; 3652 bail: 3653 return ret; 3654 } 3655 3656 /* returns 1 when the caller should unlock and call ocfs2_dlm_unlock */ 3657 static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb, 3658 struct ocfs2_lock_res *lockres) 3659 { 3660 assert_spin_locked(&lockres->l_lock); 3661 3662 if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) { 3663 /* If we're already trying to cancel a lock conversion 3664 * then just drop the spinlock and allow the caller to 3665 * requeue this lock. */ 3666 mlog(ML_BASTS, "lockres %s, skip convert\n", lockres->l_name); 3667 return 0; 3668 } 3669 3670 /* were we in a convert when we got the bast fire? */ 3671 BUG_ON(lockres->l_action != OCFS2_AST_CONVERT && 3672 lockres->l_action != OCFS2_AST_DOWNCONVERT); 3673 /* set things up for the unlockast to know to just 3674 * clear out the ast_action and unset busy, etc. */ 3675 lockres->l_unlock_action = OCFS2_UNLOCK_CANCEL_CONVERT; 3676 3677 mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_BUSY), 3678 "lock %s, invalid flags: 0x%lx\n", 3679 lockres->l_name, lockres->l_flags); 3680 3681 mlog(ML_BASTS, "lockres %s\n", lockres->l_name); 3682 3683 return 1; 3684 } 3685 3686 static int ocfs2_cancel_convert(struct ocfs2_super *osb, 3687 struct ocfs2_lock_res *lockres) 3688 { 3689 int ret; 3690 3691 ret = ocfs2_dlm_unlock(osb->cconn, &lockres->l_lksb, 3692 DLM_LKF_CANCEL); 3693 if (ret) { 3694 ocfs2_log_dlm_error("ocfs2_dlm_unlock", ret, lockres); 3695 ocfs2_recover_from_dlm_error(lockres, 0); 3696 } 3697 3698 mlog(ML_BASTS, "lockres %s\n", lockres->l_name); 3699 3700 return ret; 3701 } 3702 3703 static int ocfs2_unblock_lock(struct ocfs2_super *osb, 3704 struct ocfs2_lock_res *lockres, 3705 struct ocfs2_unblock_ctl *ctl) 3706 { 3707 unsigned long flags; 3708 int blocking; 3709 int new_level; 3710 int level; 3711 int ret = 0; 3712 int set_lvb = 0; 3713 unsigned int gen; 3714 3715 spin_lock_irqsave(&lockres->l_lock, flags); 3716 3717 recheck: 3718 /* 3719 * Is it still blocking? If not, we have no more work to do. 3720 */ 3721 if (!(lockres->l_flags & OCFS2_LOCK_BLOCKED)) { 3722 BUG_ON(lockres->l_blocking != DLM_LOCK_NL); 3723 spin_unlock_irqrestore(&lockres->l_lock, flags); 3724 ret = 0; 3725 goto leave; 3726 } 3727 3728 if (lockres->l_flags & OCFS2_LOCK_BUSY) { 3729 /* XXX 3730 * This is a *big* race. The OCFS2_LOCK_PENDING flag 3731 * exists entirely for one reason - another thread has set 3732 * OCFS2_LOCK_BUSY, but has *NOT* yet called dlm_lock(). 3733 * 3734 * If we do ocfs2_cancel_convert() before the other thread 3735 * calls dlm_lock(), our cancel will do nothing. We will 3736 * get no ast, and we will have no way of knowing the 3737 * cancel failed. Meanwhile, the other thread will call 3738 * into dlm_lock() and wait...forever. 3739 * 3740 * Why forever? Because another node has asked for the 3741 * lock first; that's why we're here in unblock_lock(). 3742 * 3743 * The solution is OCFS2_LOCK_PENDING. When PENDING is 3744 * set, we just requeue the unblock. Only when the other 3745 * thread has called dlm_lock() and cleared PENDING will 3746 * we then cancel their request. 3747 * 3748 * All callers of dlm_lock() must set OCFS2_DLM_PENDING 3749 * at the same time they set OCFS2_DLM_BUSY. They must 3750 * clear OCFS2_DLM_PENDING after dlm_lock() returns. 3751 */ 3752 if (lockres->l_flags & OCFS2_LOCK_PENDING) { 3753 mlog(ML_BASTS, "lockres %s, ReQ: Pending\n", 3754 lockres->l_name); 3755 goto leave_requeue; 3756 } 3757 3758 ctl->requeue = 1; 3759 ret = ocfs2_prepare_cancel_convert(osb, lockres); 3760 spin_unlock_irqrestore(&lockres->l_lock, flags); 3761 if (ret) { 3762 ret = ocfs2_cancel_convert(osb, lockres); 3763 if (ret < 0) 3764 mlog_errno(ret); 3765 } 3766 goto leave; 3767 } 3768 3769 /* 3770 * This prevents livelocks. OCFS2_LOCK_UPCONVERT_FINISHING flag is 3771 * set when the ast is received for an upconvert just before the 3772 * OCFS2_LOCK_BUSY flag is cleared. Now if the fs received a bast 3773 * on the heels of the ast, we want to delay the downconvert just 3774 * enough to allow the up requestor to do its task. Because this 3775 * lock is in the blocked queue, the lock will be downconverted 3776 * as soon as the requestor is done with the lock. 3777 */ 3778 if (lockres->l_flags & OCFS2_LOCK_UPCONVERT_FINISHING) 3779 goto leave_requeue; 3780 3781 /* 3782 * How can we block and yet be at NL? We were trying to upconvert 3783 * from NL and got canceled. The code comes back here, and now 3784 * we notice and clear BLOCKING. 3785 */ 3786 if (lockres->l_level == DLM_LOCK_NL) { 3787 BUG_ON(lockres->l_ex_holders || lockres->l_ro_holders); 3788 mlog(ML_BASTS, "lockres %s, Aborting dc\n", lockres->l_name); 3789 lockres->l_blocking = DLM_LOCK_NL; 3790 lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED); 3791 spin_unlock_irqrestore(&lockres->l_lock, flags); 3792 goto leave; 3793 } 3794 3795 /* if we're blocking an exclusive and we have *any* holders, 3796 * then requeue. */ 3797 if ((lockres->l_blocking == DLM_LOCK_EX) 3798 && (lockres->l_ex_holders || lockres->l_ro_holders)) { 3799 mlog(ML_BASTS, "lockres %s, ReQ: EX/PR Holders %u,%u\n", 3800 lockres->l_name, lockres->l_ex_holders, 3801 lockres->l_ro_holders); 3802 goto leave_requeue; 3803 } 3804 3805 /* If it's a PR we're blocking, then only 3806 * requeue if we've got any EX holders */ 3807 if (lockres->l_blocking == DLM_LOCK_PR && 3808 lockres->l_ex_holders) { 3809 mlog(ML_BASTS, "lockres %s, ReQ: EX Holders %u\n", 3810 lockres->l_name, lockres->l_ex_holders); 3811 goto leave_requeue; 3812 } 3813 3814 /* 3815 * Can we get a lock in this state if the holder counts are 3816 * zero? The meta data unblock code used to check this. 3817 */ 3818 if ((lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH) 3819 && (lockres->l_flags & OCFS2_LOCK_REFRESHING)) { 3820 mlog(ML_BASTS, "lockres %s, ReQ: Lock Refreshing\n", 3821 lockres->l_name); 3822 goto leave_requeue; 3823 } 3824 3825 new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking); 3826 3827 if (lockres->l_ops->check_downconvert 3828 && !lockres->l_ops->check_downconvert(lockres, new_level)) { 3829 mlog(ML_BASTS, "lockres %s, ReQ: Checkpointing\n", 3830 lockres->l_name); 3831 goto leave_requeue; 3832 } 3833 3834 /* If we get here, then we know that there are no more 3835 * incompatible holders (and anyone asking for an incompatible 3836 * lock is blocked). We can now downconvert the lock */ 3837 if (!lockres->l_ops->downconvert_worker) 3838 goto downconvert; 3839 3840 /* Some lockres types want to do a bit of work before 3841 * downconverting a lock. Allow that here. The worker function 3842 * may sleep, so we save off a copy of what we're blocking as 3843 * it may change while we're not holding the spin lock. */ 3844 blocking = lockres->l_blocking; 3845 level = lockres->l_level; 3846 spin_unlock_irqrestore(&lockres->l_lock, flags); 3847 3848 ctl->unblock_action = lockres->l_ops->downconvert_worker(lockres, blocking); 3849 3850 if (ctl->unblock_action == UNBLOCK_STOP_POST) { 3851 mlog(ML_BASTS, "lockres %s, UNBLOCK_STOP_POST\n", 3852 lockres->l_name); 3853 goto leave; 3854 } 3855 3856 spin_lock_irqsave(&lockres->l_lock, flags); 3857 if ((blocking != lockres->l_blocking) || (level != lockres->l_level)) { 3858 /* If this changed underneath us, then we can't drop 3859 * it just yet. */ 3860 mlog(ML_BASTS, "lockres %s, block=%d:%d, level=%d:%d, " 3861 "Recheck\n", lockres->l_name, blocking, 3862 lockres->l_blocking, level, lockres->l_level); 3863 goto recheck; 3864 } 3865 3866 downconvert: 3867 ctl->requeue = 0; 3868 3869 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) { 3870 if (lockres->l_level == DLM_LOCK_EX) 3871 set_lvb = 1; 3872 3873 /* 3874 * We only set the lvb if the lock has been fully 3875 * refreshed - otherwise we risk setting stale 3876 * data. Otherwise, there's no need to actually clear 3877 * out the lvb here as it's value is still valid. 3878 */ 3879 if (set_lvb && !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) 3880 lockres->l_ops->set_lvb(lockres); 3881 } 3882 3883 gen = ocfs2_prepare_downconvert(lockres, new_level); 3884 spin_unlock_irqrestore(&lockres->l_lock, flags); 3885 ret = ocfs2_downconvert_lock(osb, lockres, new_level, set_lvb, 3886 gen); 3887 3888 leave: 3889 if (ret) 3890 mlog_errno(ret); 3891 return ret; 3892 3893 leave_requeue: 3894 spin_unlock_irqrestore(&lockres->l_lock, flags); 3895 ctl->requeue = 1; 3896 3897 return 0; 3898 } 3899 3900 static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres, 3901 int blocking) 3902 { 3903 struct inode *inode; 3904 struct address_space *mapping; 3905 struct ocfs2_inode_info *oi; 3906 3907 inode = ocfs2_lock_res_inode(lockres); 3908 mapping = inode->i_mapping; 3909 3910 if (S_ISDIR(inode->i_mode)) { 3911 oi = OCFS2_I(inode); 3912 oi->ip_dir_lock_gen++; 3913 mlog(0, "generation: %u\n", oi->ip_dir_lock_gen); 3914 goto out; 3915 } 3916 3917 if (!S_ISREG(inode->i_mode)) 3918 goto out; 3919 3920 /* 3921 * We need this before the filemap_fdatawrite() so that it can 3922 * transfer the dirty bit from the PTE to the 3923 * page. Unfortunately this means that even for EX->PR 3924 * downconverts, we'll lose our mappings and have to build 3925 * them up again. 3926 */ 3927 unmap_mapping_range(mapping, 0, 0, 0); 3928 3929 if (filemap_fdatawrite(mapping)) { 3930 mlog(ML_ERROR, "Could not sync inode %llu for downconvert!", 3931 (unsigned long long)OCFS2_I(inode)->ip_blkno); 3932 } 3933 sync_mapping_buffers(mapping); 3934 if (blocking == DLM_LOCK_EX) { 3935 truncate_inode_pages(mapping, 0); 3936 } else { 3937 /* We only need to wait on the I/O if we're not also 3938 * truncating pages because truncate_inode_pages waits 3939 * for us above. We don't truncate pages if we're 3940 * blocking anything < EXMODE because we want to keep 3941 * them around in that case. */ 3942 filemap_fdatawait(mapping); 3943 } 3944 3945 forget_all_cached_acls(inode); 3946 3947 out: 3948 return UNBLOCK_CONTINUE; 3949 } 3950 3951 static int ocfs2_ci_checkpointed(struct ocfs2_caching_info *ci, 3952 struct ocfs2_lock_res *lockres, 3953 int new_level) 3954 { 3955 int checkpointed = ocfs2_ci_fully_checkpointed(ci); 3956 3957 BUG_ON(new_level != DLM_LOCK_NL && new_level != DLM_LOCK_PR); 3958 BUG_ON(lockres->l_level != DLM_LOCK_EX && !checkpointed); 3959 3960 if (checkpointed) 3961 return 1; 3962 3963 ocfs2_start_checkpoint(OCFS2_SB(ocfs2_metadata_cache_get_super(ci))); 3964 return 0; 3965 } 3966 3967 static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres, 3968 int new_level) 3969 { 3970 struct inode *inode = ocfs2_lock_res_inode(lockres); 3971 3972 return ocfs2_ci_checkpointed(INODE_CACHE(inode), lockres, new_level); 3973 } 3974 3975 static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres) 3976 { 3977 struct inode *inode = ocfs2_lock_res_inode(lockres); 3978 3979 __ocfs2_stuff_meta_lvb(inode); 3980 } 3981 3982 /* 3983 * Does the final reference drop on our dentry lock. Right now this 3984 * happens in the downconvert thread, but we could choose to simplify the 3985 * dlmglue API and push these off to the ocfs2_wq in the future. 3986 */ 3987 static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb, 3988 struct ocfs2_lock_res *lockres) 3989 { 3990 struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres); 3991 ocfs2_dentry_lock_put(osb, dl); 3992 } 3993 3994 /* 3995 * d_delete() matching dentries before the lock downconvert. 3996 * 3997 * At this point, any process waiting to destroy the 3998 * dentry_lock due to last ref count is stopped by the 3999 * OCFS2_LOCK_QUEUED flag. 4000 * 4001 * We have two potential problems 4002 * 4003 * 1) If we do the last reference drop on our dentry_lock (via dput) 4004 * we'll wind up in ocfs2_release_dentry_lock(), waiting on 4005 * the downconvert to finish. Instead we take an elevated 4006 * reference and push the drop until after we've completed our 4007 * unblock processing. 4008 * 4009 * 2) There might be another process with a final reference, 4010 * waiting on us to finish processing. If this is the case, we 4011 * detect it and exit out - there's no more dentries anyway. 4012 */ 4013 static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres, 4014 int blocking) 4015 { 4016 struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres); 4017 struct ocfs2_inode_info *oi = OCFS2_I(dl->dl_inode); 4018 struct dentry *dentry; 4019 unsigned long flags; 4020 int extra_ref = 0; 4021 4022 /* 4023 * This node is blocking another node from getting a read 4024 * lock. This happens when we've renamed within a 4025 * directory. We've forced the other nodes to d_delete(), but 4026 * we never actually dropped our lock because it's still 4027 * valid. The downconvert code will retain a PR for this node, 4028 * so there's no further work to do. 4029 */ 4030 if (blocking == DLM_LOCK_PR) 4031 return UNBLOCK_CONTINUE; 4032 4033 /* 4034 * Mark this inode as potentially orphaned. The code in 4035 * ocfs2_delete_inode() will figure out whether it actually 4036 * needs to be freed or not. 4037 */ 4038 spin_lock(&oi->ip_lock); 4039 oi->ip_flags |= OCFS2_INODE_MAYBE_ORPHANED; 4040 spin_unlock(&oi->ip_lock); 4041 4042 /* 4043 * Yuck. We need to make sure however that the check of 4044 * OCFS2_LOCK_FREEING and the extra reference are atomic with 4045 * respect to a reference decrement or the setting of that 4046 * flag. 4047 */ 4048 spin_lock_irqsave(&lockres->l_lock, flags); 4049 spin_lock(&dentry_attach_lock); 4050 if (!(lockres->l_flags & OCFS2_LOCK_FREEING) 4051 && dl->dl_count) { 4052 dl->dl_count++; 4053 extra_ref = 1; 4054 } 4055 spin_unlock(&dentry_attach_lock); 4056 spin_unlock_irqrestore(&lockres->l_lock, flags); 4057 4058 mlog(0, "extra_ref = %d\n", extra_ref); 4059 4060 /* 4061 * We have a process waiting on us in ocfs2_dentry_iput(), 4062 * which means we can't have any more outstanding 4063 * aliases. There's no need to do any more work. 4064 */ 4065 if (!extra_ref) 4066 return UNBLOCK_CONTINUE; 4067 4068 spin_lock(&dentry_attach_lock); 4069 while (1) { 4070 dentry = ocfs2_find_local_alias(dl->dl_inode, 4071 dl->dl_parent_blkno, 1); 4072 if (!dentry) 4073 break; 4074 spin_unlock(&dentry_attach_lock); 4075 4076 if (S_ISDIR(dl->dl_inode->i_mode)) 4077 shrink_dcache_parent(dentry); 4078 4079 mlog(0, "d_delete(%pd);\n", dentry); 4080 4081 /* 4082 * The following dcache calls may do an 4083 * iput(). Normally we don't want that from the 4084 * downconverting thread, but in this case it's ok 4085 * because the requesting node already has an 4086 * exclusive lock on the inode, so it can't be queued 4087 * for a downconvert. 4088 */ 4089 d_delete(dentry); 4090 dput(dentry); 4091 4092 spin_lock(&dentry_attach_lock); 4093 } 4094 spin_unlock(&dentry_attach_lock); 4095 4096 /* 4097 * If we are the last holder of this dentry lock, there is no 4098 * reason to downconvert so skip straight to the unlock. 4099 */ 4100 if (dl->dl_count == 1) 4101 return UNBLOCK_STOP_POST; 4102 4103 return UNBLOCK_CONTINUE_POST; 4104 } 4105 4106 static int ocfs2_check_refcount_downconvert(struct ocfs2_lock_res *lockres, 4107 int new_level) 4108 { 4109 struct ocfs2_refcount_tree *tree = 4110 ocfs2_lock_res_refcount_tree(lockres); 4111 4112 return ocfs2_ci_checkpointed(&tree->rf_ci, lockres, new_level); 4113 } 4114 4115 static int ocfs2_refcount_convert_worker(struct ocfs2_lock_res *lockres, 4116 int blocking) 4117 { 4118 struct ocfs2_refcount_tree *tree = 4119 ocfs2_lock_res_refcount_tree(lockres); 4120 4121 ocfs2_metadata_cache_purge(&tree->rf_ci); 4122 4123 return UNBLOCK_CONTINUE; 4124 } 4125 4126 static void ocfs2_set_qinfo_lvb(struct ocfs2_lock_res *lockres) 4127 { 4128 struct ocfs2_qinfo_lvb *lvb; 4129 struct ocfs2_mem_dqinfo *oinfo = ocfs2_lock_res_qinfo(lockres); 4130 struct mem_dqinfo *info = sb_dqinfo(oinfo->dqi_gi.dqi_sb, 4131 oinfo->dqi_gi.dqi_type); 4132 4133 lvb = ocfs2_dlm_lvb(&lockres->l_lksb); 4134 lvb->lvb_version = OCFS2_QINFO_LVB_VERSION; 4135 lvb->lvb_bgrace = cpu_to_be32(info->dqi_bgrace); 4136 lvb->lvb_igrace = cpu_to_be32(info->dqi_igrace); 4137 lvb->lvb_syncms = cpu_to_be32(oinfo->dqi_syncms); 4138 lvb->lvb_blocks = cpu_to_be32(oinfo->dqi_gi.dqi_blocks); 4139 lvb->lvb_free_blk = cpu_to_be32(oinfo->dqi_gi.dqi_free_blk); 4140 lvb->lvb_free_entry = cpu_to_be32(oinfo->dqi_gi.dqi_free_entry); 4141 } 4142 4143 void ocfs2_qinfo_unlock(struct ocfs2_mem_dqinfo *oinfo, int ex) 4144 { 4145 struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock; 4146 struct ocfs2_super *osb = OCFS2_SB(oinfo->dqi_gi.dqi_sb); 4147 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 4148 4149 if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb)) 4150 ocfs2_cluster_unlock(osb, lockres, level); 4151 } 4152 4153 static int ocfs2_refresh_qinfo(struct ocfs2_mem_dqinfo *oinfo) 4154 { 4155 struct mem_dqinfo *info = sb_dqinfo(oinfo->dqi_gi.dqi_sb, 4156 oinfo->dqi_gi.dqi_type); 4157 struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock; 4158 struct ocfs2_qinfo_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb); 4159 struct buffer_head *bh = NULL; 4160 struct ocfs2_global_disk_dqinfo *gdinfo; 4161 int status = 0; 4162 4163 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) && 4164 lvb->lvb_version == OCFS2_QINFO_LVB_VERSION) { 4165 info->dqi_bgrace = be32_to_cpu(lvb->lvb_bgrace); 4166 info->dqi_igrace = be32_to_cpu(lvb->lvb_igrace); 4167 oinfo->dqi_syncms = be32_to_cpu(lvb->lvb_syncms); 4168 oinfo->dqi_gi.dqi_blocks = be32_to_cpu(lvb->lvb_blocks); 4169 oinfo->dqi_gi.dqi_free_blk = be32_to_cpu(lvb->lvb_free_blk); 4170 oinfo->dqi_gi.dqi_free_entry = 4171 be32_to_cpu(lvb->lvb_free_entry); 4172 } else { 4173 status = ocfs2_read_quota_phys_block(oinfo->dqi_gqinode, 4174 oinfo->dqi_giblk, &bh); 4175 if (status) { 4176 mlog_errno(status); 4177 goto bail; 4178 } 4179 gdinfo = (struct ocfs2_global_disk_dqinfo *) 4180 (bh->b_data + OCFS2_GLOBAL_INFO_OFF); 4181 info->dqi_bgrace = le32_to_cpu(gdinfo->dqi_bgrace); 4182 info->dqi_igrace = le32_to_cpu(gdinfo->dqi_igrace); 4183 oinfo->dqi_syncms = le32_to_cpu(gdinfo->dqi_syncms); 4184 oinfo->dqi_gi.dqi_blocks = le32_to_cpu(gdinfo->dqi_blocks); 4185 oinfo->dqi_gi.dqi_free_blk = le32_to_cpu(gdinfo->dqi_free_blk); 4186 oinfo->dqi_gi.dqi_free_entry = 4187 le32_to_cpu(gdinfo->dqi_free_entry); 4188 brelse(bh); 4189 ocfs2_track_lock_refresh(lockres); 4190 } 4191 4192 bail: 4193 return status; 4194 } 4195 4196 /* Lock quota info, this function expects at least shared lock on the quota file 4197 * so that we can safely refresh quota info from disk. */ 4198 int ocfs2_qinfo_lock(struct ocfs2_mem_dqinfo *oinfo, int ex) 4199 { 4200 struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock; 4201 struct ocfs2_super *osb = OCFS2_SB(oinfo->dqi_gi.dqi_sb); 4202 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 4203 int status = 0; 4204 4205 /* On RO devices, locking really isn't needed... */ 4206 if (ocfs2_is_hard_readonly(osb)) { 4207 if (ex) 4208 status = -EROFS; 4209 goto bail; 4210 } 4211 if (ocfs2_mount_local(osb)) 4212 goto bail; 4213 4214 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0); 4215 if (status < 0) { 4216 mlog_errno(status); 4217 goto bail; 4218 } 4219 if (!ocfs2_should_refresh_lock_res(lockres)) 4220 goto bail; 4221 /* OK, we have the lock but we need to refresh the quota info */ 4222 status = ocfs2_refresh_qinfo(oinfo); 4223 if (status) 4224 ocfs2_qinfo_unlock(oinfo, ex); 4225 ocfs2_complete_lock_res_refresh(lockres, status); 4226 bail: 4227 return status; 4228 } 4229 4230 int ocfs2_refcount_lock(struct ocfs2_refcount_tree *ref_tree, int ex) 4231 { 4232 int status; 4233 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 4234 struct ocfs2_lock_res *lockres = &ref_tree->rf_lockres; 4235 struct ocfs2_super *osb = lockres->l_priv; 4236 4237 4238 if (ocfs2_is_hard_readonly(osb)) 4239 return -EROFS; 4240 4241 if (ocfs2_mount_local(osb)) 4242 return 0; 4243 4244 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0); 4245 if (status < 0) 4246 mlog_errno(status); 4247 4248 return status; 4249 } 4250 4251 void ocfs2_refcount_unlock(struct ocfs2_refcount_tree *ref_tree, int ex) 4252 { 4253 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 4254 struct ocfs2_lock_res *lockres = &ref_tree->rf_lockres; 4255 struct ocfs2_super *osb = lockres->l_priv; 4256 4257 if (!ocfs2_mount_local(osb)) 4258 ocfs2_cluster_unlock(osb, lockres, level); 4259 } 4260 4261 static void ocfs2_process_blocked_lock(struct ocfs2_super *osb, 4262 struct ocfs2_lock_res *lockres) 4263 { 4264 int status; 4265 struct ocfs2_unblock_ctl ctl = {0, 0,}; 4266 unsigned long flags; 4267 4268 /* Our reference to the lockres in this function can be 4269 * considered valid until we remove the OCFS2_LOCK_QUEUED 4270 * flag. */ 4271 4272 BUG_ON(!lockres); 4273 BUG_ON(!lockres->l_ops); 4274 4275 mlog(ML_BASTS, "lockres %s blocked\n", lockres->l_name); 4276 4277 /* Detect whether a lock has been marked as going away while 4278 * the downconvert thread was processing other things. A lock can 4279 * still be marked with OCFS2_LOCK_FREEING after this check, 4280 * but short circuiting here will still save us some 4281 * performance. */ 4282 spin_lock_irqsave(&lockres->l_lock, flags); 4283 if (lockres->l_flags & OCFS2_LOCK_FREEING) 4284 goto unqueue; 4285 spin_unlock_irqrestore(&lockres->l_lock, flags); 4286 4287 status = ocfs2_unblock_lock(osb, lockres, &ctl); 4288 if (status < 0) 4289 mlog_errno(status); 4290 4291 spin_lock_irqsave(&lockres->l_lock, flags); 4292 unqueue: 4293 if (lockres->l_flags & OCFS2_LOCK_FREEING || !ctl.requeue) { 4294 lockres_clear_flags(lockres, OCFS2_LOCK_QUEUED); 4295 } else 4296 ocfs2_schedule_blocked_lock(osb, lockres); 4297 4298 mlog(ML_BASTS, "lockres %s, requeue = %s.\n", lockres->l_name, 4299 ctl.requeue ? "yes" : "no"); 4300 spin_unlock_irqrestore(&lockres->l_lock, flags); 4301 4302 if (ctl.unblock_action != UNBLOCK_CONTINUE 4303 && lockres->l_ops->post_unlock) 4304 lockres->l_ops->post_unlock(osb, lockres); 4305 } 4306 4307 static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb, 4308 struct ocfs2_lock_res *lockres) 4309 { 4310 unsigned long flags; 4311 4312 assert_spin_locked(&lockres->l_lock); 4313 4314 if (lockres->l_flags & OCFS2_LOCK_FREEING) { 4315 /* Do not schedule a lock for downconvert when it's on 4316 * the way to destruction - any nodes wanting access 4317 * to the resource will get it soon. */ 4318 mlog(ML_BASTS, "lockres %s won't be scheduled: flags 0x%lx\n", 4319 lockres->l_name, lockres->l_flags); 4320 return; 4321 } 4322 4323 lockres_or_flags(lockres, OCFS2_LOCK_QUEUED); 4324 4325 spin_lock_irqsave(&osb->dc_task_lock, flags); 4326 if (list_empty(&lockres->l_blocked_list)) { 4327 list_add_tail(&lockres->l_blocked_list, 4328 &osb->blocked_lock_list); 4329 osb->blocked_lock_count++; 4330 } 4331 spin_unlock_irqrestore(&osb->dc_task_lock, flags); 4332 } 4333 4334 static void ocfs2_downconvert_thread_do_work(struct ocfs2_super *osb) 4335 { 4336 unsigned long processed; 4337 unsigned long flags; 4338 struct ocfs2_lock_res *lockres; 4339 4340 spin_lock_irqsave(&osb->dc_task_lock, flags); 4341 /* grab this early so we know to try again if a state change and 4342 * wake happens part-way through our work */ 4343 osb->dc_work_sequence = osb->dc_wake_sequence; 4344 4345 processed = osb->blocked_lock_count; 4346 /* 4347 * blocked lock processing in this loop might call iput which can 4348 * remove items off osb->blocked_lock_list. Downconvert up to 4349 * 'processed' number of locks, but stop short if we had some 4350 * removed in ocfs2_mark_lockres_freeing when downconverting. 4351 */ 4352 while (processed && !list_empty(&osb->blocked_lock_list)) { 4353 lockres = list_entry(osb->blocked_lock_list.next, 4354 struct ocfs2_lock_res, l_blocked_list); 4355 list_del_init(&lockres->l_blocked_list); 4356 osb->blocked_lock_count--; 4357 spin_unlock_irqrestore(&osb->dc_task_lock, flags); 4358 4359 BUG_ON(!processed); 4360 processed--; 4361 4362 ocfs2_process_blocked_lock(osb, lockres); 4363 4364 spin_lock_irqsave(&osb->dc_task_lock, flags); 4365 } 4366 spin_unlock_irqrestore(&osb->dc_task_lock, flags); 4367 } 4368 4369 static int ocfs2_downconvert_thread_lists_empty(struct ocfs2_super *osb) 4370 { 4371 int empty = 0; 4372 unsigned long flags; 4373 4374 spin_lock_irqsave(&osb->dc_task_lock, flags); 4375 if (list_empty(&osb->blocked_lock_list)) 4376 empty = 1; 4377 4378 spin_unlock_irqrestore(&osb->dc_task_lock, flags); 4379 return empty; 4380 } 4381 4382 static int ocfs2_downconvert_thread_should_wake(struct ocfs2_super *osb) 4383 { 4384 int should_wake = 0; 4385 unsigned long flags; 4386 4387 spin_lock_irqsave(&osb->dc_task_lock, flags); 4388 if (osb->dc_work_sequence != osb->dc_wake_sequence) 4389 should_wake = 1; 4390 spin_unlock_irqrestore(&osb->dc_task_lock, flags); 4391 4392 return should_wake; 4393 } 4394 4395 static int ocfs2_downconvert_thread(void *arg) 4396 { 4397 struct ocfs2_super *osb = arg; 4398 4399 /* only quit once we've been asked to stop and there is no more 4400 * work available */ 4401 while (!(kthread_should_stop() && 4402 ocfs2_downconvert_thread_lists_empty(osb))) { 4403 4404 wait_event_interruptible(osb->dc_event, 4405 ocfs2_downconvert_thread_should_wake(osb) || 4406 kthread_should_stop()); 4407 4408 mlog(0, "downconvert_thread: awoken\n"); 4409 4410 ocfs2_downconvert_thread_do_work(osb); 4411 } 4412 4413 osb->dc_task = NULL; 4414 return 0; 4415 } 4416 4417 void ocfs2_wake_downconvert_thread(struct ocfs2_super *osb) 4418 { 4419 unsigned long flags; 4420 4421 spin_lock_irqsave(&osb->dc_task_lock, flags); 4422 /* make sure the voting thread gets a swipe at whatever changes 4423 * the caller may have made to the voting state */ 4424 osb->dc_wake_sequence++; 4425 spin_unlock_irqrestore(&osb->dc_task_lock, flags); 4426 wake_up(&osb->dc_event); 4427 } 4428