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 static void ocfs2_nfs_sync_lock_init(struct ocfs2_super *osb) 693 { 694 ocfs2_nfs_sync_lock_res_init(&osb->osb_nfs_sync_lockres, osb); 695 init_rwsem(&osb->nfs_sync_rwlock); 696 } 697 698 void ocfs2_trim_fs_lock_res_init(struct ocfs2_super *osb) 699 { 700 struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres; 701 702 /* Only one trimfs thread are allowed to work at the same time. */ 703 mutex_lock(&osb->obs_trim_fs_mutex); 704 705 ocfs2_lock_res_init_once(lockres); 706 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_TRIM_FS, 0, 0, lockres->l_name); 707 ocfs2_lock_res_init_common(osb, lockres, OCFS2_LOCK_TYPE_TRIM_FS, 708 &ocfs2_trim_fs_lops, osb); 709 } 710 711 void ocfs2_trim_fs_lock_res_uninit(struct ocfs2_super *osb) 712 { 713 struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres; 714 715 ocfs2_simple_drop_lockres(osb, lockres); 716 ocfs2_lock_res_free(lockres); 717 718 mutex_unlock(&osb->obs_trim_fs_mutex); 719 } 720 721 static void ocfs2_orphan_scan_lock_res_init(struct ocfs2_lock_res *res, 722 struct ocfs2_super *osb) 723 { 724 ocfs2_lock_res_init_once(res); 725 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_ORPHAN_SCAN, 0, 0, res->l_name); 726 ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_ORPHAN_SCAN, 727 &ocfs2_orphan_scan_lops, osb); 728 } 729 730 void ocfs2_file_lock_res_init(struct ocfs2_lock_res *lockres, 731 struct ocfs2_file_private *fp) 732 { 733 struct inode *inode = fp->fp_file->f_mapping->host; 734 struct ocfs2_inode_info *oi = OCFS2_I(inode); 735 736 ocfs2_lock_res_init_once(lockres); 737 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_FLOCK, oi->ip_blkno, 738 inode->i_generation, lockres->l_name); 739 ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), lockres, 740 OCFS2_LOCK_TYPE_FLOCK, &ocfs2_flock_lops, 741 fp); 742 lockres->l_flags |= OCFS2_LOCK_NOCACHE; 743 } 744 745 void ocfs2_qinfo_lock_res_init(struct ocfs2_lock_res *lockres, 746 struct ocfs2_mem_dqinfo *info) 747 { 748 ocfs2_lock_res_init_once(lockres); 749 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_QINFO, info->dqi_gi.dqi_type, 750 0, lockres->l_name); 751 ocfs2_lock_res_init_common(OCFS2_SB(info->dqi_gi.dqi_sb), lockres, 752 OCFS2_LOCK_TYPE_QINFO, &ocfs2_qinfo_lops, 753 info); 754 } 755 756 void ocfs2_refcount_lock_res_init(struct ocfs2_lock_res *lockres, 757 struct ocfs2_super *osb, u64 ref_blkno, 758 unsigned int generation) 759 { 760 ocfs2_lock_res_init_once(lockres); 761 ocfs2_build_lock_name(OCFS2_LOCK_TYPE_REFCOUNT, ref_blkno, 762 generation, lockres->l_name); 763 ocfs2_lock_res_init_common(osb, lockres, OCFS2_LOCK_TYPE_REFCOUNT, 764 &ocfs2_refcount_block_lops, osb); 765 } 766 767 void ocfs2_lock_res_free(struct ocfs2_lock_res *res) 768 { 769 if (!(res->l_flags & OCFS2_LOCK_INITIALIZED)) 770 return; 771 772 ocfs2_remove_lockres_tracking(res); 773 774 mlog_bug_on_msg(!list_empty(&res->l_blocked_list), 775 "Lockres %s is on the blocked list\n", 776 res->l_name); 777 mlog_bug_on_msg(!list_empty(&res->l_mask_waiters), 778 "Lockres %s has mask waiters pending\n", 779 res->l_name); 780 mlog_bug_on_msg(spin_is_locked(&res->l_lock), 781 "Lockres %s is locked\n", 782 res->l_name); 783 mlog_bug_on_msg(res->l_ro_holders, 784 "Lockres %s has %u ro holders\n", 785 res->l_name, res->l_ro_holders); 786 mlog_bug_on_msg(res->l_ex_holders, 787 "Lockres %s has %u ex holders\n", 788 res->l_name, res->l_ex_holders); 789 790 /* Need to clear out the lock status block for the dlm */ 791 memset(&res->l_lksb, 0, sizeof(res->l_lksb)); 792 793 res->l_flags = 0UL; 794 } 795 796 /* 797 * Keep a list of processes who have interest in a lockres. 798 * Note: this is now only uesed for check recursive cluster locking. 799 */ 800 static inline void ocfs2_add_holder(struct ocfs2_lock_res *lockres, 801 struct ocfs2_lock_holder *oh) 802 { 803 INIT_LIST_HEAD(&oh->oh_list); 804 oh->oh_owner_pid = get_pid(task_pid(current)); 805 806 spin_lock(&lockres->l_lock); 807 list_add_tail(&oh->oh_list, &lockres->l_holders); 808 spin_unlock(&lockres->l_lock); 809 } 810 811 static struct ocfs2_lock_holder * 812 ocfs2_pid_holder(struct ocfs2_lock_res *lockres, 813 struct pid *pid) 814 { 815 struct ocfs2_lock_holder *oh; 816 817 spin_lock(&lockres->l_lock); 818 list_for_each_entry(oh, &lockres->l_holders, oh_list) { 819 if (oh->oh_owner_pid == pid) { 820 spin_unlock(&lockres->l_lock); 821 return oh; 822 } 823 } 824 spin_unlock(&lockres->l_lock); 825 return NULL; 826 } 827 828 static inline void ocfs2_remove_holder(struct ocfs2_lock_res *lockres, 829 struct ocfs2_lock_holder *oh) 830 { 831 spin_lock(&lockres->l_lock); 832 list_del(&oh->oh_list); 833 spin_unlock(&lockres->l_lock); 834 835 put_pid(oh->oh_owner_pid); 836 } 837 838 839 static inline void ocfs2_inc_holders(struct ocfs2_lock_res *lockres, 840 int level) 841 { 842 BUG_ON(!lockres); 843 844 switch(level) { 845 case DLM_LOCK_EX: 846 lockres->l_ex_holders++; 847 break; 848 case DLM_LOCK_PR: 849 lockres->l_ro_holders++; 850 break; 851 default: 852 BUG(); 853 } 854 } 855 856 static inline void ocfs2_dec_holders(struct ocfs2_lock_res *lockres, 857 int level) 858 { 859 BUG_ON(!lockres); 860 861 switch(level) { 862 case DLM_LOCK_EX: 863 BUG_ON(!lockres->l_ex_holders); 864 lockres->l_ex_holders--; 865 break; 866 case DLM_LOCK_PR: 867 BUG_ON(!lockres->l_ro_holders); 868 lockres->l_ro_holders--; 869 break; 870 default: 871 BUG(); 872 } 873 } 874 875 /* WARNING: This function lives in a world where the only three lock 876 * levels are EX, PR, and NL. It *will* have to be adjusted when more 877 * lock types are added. */ 878 static inline int ocfs2_highest_compat_lock_level(int level) 879 { 880 int new_level = DLM_LOCK_EX; 881 882 if (level == DLM_LOCK_EX) 883 new_level = DLM_LOCK_NL; 884 else if (level == DLM_LOCK_PR) 885 new_level = DLM_LOCK_PR; 886 return new_level; 887 } 888 889 static void lockres_set_flags(struct ocfs2_lock_res *lockres, 890 unsigned long newflags) 891 { 892 struct ocfs2_mask_waiter *mw, *tmp; 893 894 assert_spin_locked(&lockres->l_lock); 895 896 lockres->l_flags = newflags; 897 898 list_for_each_entry_safe(mw, tmp, &lockres->l_mask_waiters, mw_item) { 899 if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal) 900 continue; 901 902 list_del_init(&mw->mw_item); 903 mw->mw_status = 0; 904 complete(&mw->mw_complete); 905 ocfs2_track_lock_wait(lockres); 906 } 907 } 908 static void lockres_or_flags(struct ocfs2_lock_res *lockres, unsigned long or) 909 { 910 lockres_set_flags(lockres, lockres->l_flags | or); 911 } 912 static void lockres_clear_flags(struct ocfs2_lock_res *lockres, 913 unsigned long clear) 914 { 915 lockres_set_flags(lockres, lockres->l_flags & ~clear); 916 } 917 918 static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres) 919 { 920 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY)); 921 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED)); 922 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED)); 923 BUG_ON(lockres->l_blocking <= DLM_LOCK_NL); 924 925 lockres->l_level = lockres->l_requested; 926 if (lockres->l_level <= 927 ocfs2_highest_compat_lock_level(lockres->l_blocking)) { 928 lockres->l_blocking = DLM_LOCK_NL; 929 lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED); 930 } 931 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); 932 } 933 934 static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres) 935 { 936 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY)); 937 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED)); 938 939 /* Convert from RO to EX doesn't really need anything as our 940 * information is already up to data. Convert from NL to 941 * *anything* however should mark ourselves as needing an 942 * update */ 943 if (lockres->l_level == DLM_LOCK_NL && 944 lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH) 945 lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH); 946 947 lockres->l_level = lockres->l_requested; 948 949 /* 950 * We set the OCFS2_LOCK_UPCONVERT_FINISHING flag before clearing 951 * the OCFS2_LOCK_BUSY flag to prevent the dc thread from 952 * downconverting the lock before the upconvert has fully completed. 953 * Do not prevent the dc thread from downconverting if NONBLOCK lock 954 * had already returned. 955 */ 956 if (!(lockres->l_flags & OCFS2_LOCK_NONBLOCK_FINISHED)) 957 lockres_or_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING); 958 else 959 lockres_clear_flags(lockres, OCFS2_LOCK_NONBLOCK_FINISHED); 960 961 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); 962 } 963 964 static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres) 965 { 966 BUG_ON((!(lockres->l_flags & OCFS2_LOCK_BUSY))); 967 BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED); 968 969 if (lockres->l_requested > DLM_LOCK_NL && 970 !(lockres->l_flags & OCFS2_LOCK_LOCAL) && 971 lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH) 972 lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH); 973 974 lockres->l_level = lockres->l_requested; 975 lockres_or_flags(lockres, OCFS2_LOCK_ATTACHED); 976 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); 977 } 978 979 static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres, 980 int level) 981 { 982 int needs_downconvert = 0; 983 984 assert_spin_locked(&lockres->l_lock); 985 986 if (level > lockres->l_blocking) { 987 /* only schedule a downconvert if we haven't already scheduled 988 * one that goes low enough to satisfy the level we're 989 * blocking. this also catches the case where we get 990 * duplicate BASTs */ 991 if (ocfs2_highest_compat_lock_level(level) < 992 ocfs2_highest_compat_lock_level(lockres->l_blocking)) 993 needs_downconvert = 1; 994 995 lockres->l_blocking = level; 996 } 997 998 mlog(ML_BASTS, "lockres %s, block %d, level %d, l_block %d, dwn %d\n", 999 lockres->l_name, level, lockres->l_level, lockres->l_blocking, 1000 needs_downconvert); 1001 1002 if (needs_downconvert) 1003 lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED); 1004 mlog(0, "needs_downconvert = %d\n", needs_downconvert); 1005 return needs_downconvert; 1006 } 1007 1008 /* 1009 * OCFS2_LOCK_PENDING and l_pending_gen. 1010 * 1011 * Why does OCFS2_LOCK_PENDING exist? To close a race between setting 1012 * OCFS2_LOCK_BUSY and calling ocfs2_dlm_lock(). See ocfs2_unblock_lock() 1013 * for more details on the race. 1014 * 1015 * OCFS2_LOCK_PENDING closes the race quite nicely. However, it introduces 1016 * a race on itself. In o2dlm, we can get the ast before ocfs2_dlm_lock() 1017 * returns. The ast clears OCFS2_LOCK_BUSY, and must therefore clear 1018 * OCFS2_LOCK_PENDING at the same time. When ocfs2_dlm_lock() returns, 1019 * the caller is going to try to clear PENDING again. If nothing else is 1020 * happening, __lockres_clear_pending() sees PENDING is unset and does 1021 * nothing. 1022 * 1023 * But what if another path (eg downconvert thread) has just started a 1024 * new locking action? The other path has re-set PENDING. Our path 1025 * cannot clear PENDING, because that will re-open the original race 1026 * window. 1027 * 1028 * [Example] 1029 * 1030 * ocfs2_meta_lock() 1031 * ocfs2_cluster_lock() 1032 * set BUSY 1033 * set PENDING 1034 * drop l_lock 1035 * ocfs2_dlm_lock() 1036 * ocfs2_locking_ast() ocfs2_downconvert_thread() 1037 * clear PENDING ocfs2_unblock_lock() 1038 * take_l_lock 1039 * !BUSY 1040 * ocfs2_prepare_downconvert() 1041 * set BUSY 1042 * set PENDING 1043 * drop l_lock 1044 * take l_lock 1045 * clear PENDING 1046 * drop l_lock 1047 * <window> 1048 * ocfs2_dlm_lock() 1049 * 1050 * So as you can see, we now have a window where l_lock is not held, 1051 * PENDING is not set, and ocfs2_dlm_lock() has not been called. 1052 * 1053 * The core problem is that ocfs2_cluster_lock() has cleared the PENDING 1054 * set by ocfs2_prepare_downconvert(). That wasn't nice. 1055 * 1056 * To solve this we introduce l_pending_gen. A call to 1057 * lockres_clear_pending() will only do so when it is passed a generation 1058 * number that matches the lockres. lockres_set_pending() will return the 1059 * current generation number. When ocfs2_cluster_lock() goes to clear 1060 * PENDING, it passes the generation it got from set_pending(). In our 1061 * example above, the generation numbers will *not* match. Thus, 1062 * ocfs2_cluster_lock() will not clear the PENDING set by 1063 * ocfs2_prepare_downconvert(). 1064 */ 1065 1066 /* Unlocked version for ocfs2_locking_ast() */ 1067 static void __lockres_clear_pending(struct ocfs2_lock_res *lockres, 1068 unsigned int generation, 1069 struct ocfs2_super *osb) 1070 { 1071 assert_spin_locked(&lockres->l_lock); 1072 1073 /* 1074 * The ast and locking functions can race us here. The winner 1075 * will clear pending, the loser will not. 1076 */ 1077 if (!(lockres->l_flags & OCFS2_LOCK_PENDING) || 1078 (lockres->l_pending_gen != generation)) 1079 return; 1080 1081 lockres_clear_flags(lockres, OCFS2_LOCK_PENDING); 1082 lockres->l_pending_gen++; 1083 1084 /* 1085 * The downconvert thread may have skipped us because we 1086 * were PENDING. Wake it up. 1087 */ 1088 if (lockres->l_flags & OCFS2_LOCK_BLOCKED) 1089 ocfs2_wake_downconvert_thread(osb); 1090 } 1091 1092 /* Locked version for callers of ocfs2_dlm_lock() */ 1093 static void lockres_clear_pending(struct ocfs2_lock_res *lockres, 1094 unsigned int generation, 1095 struct ocfs2_super *osb) 1096 { 1097 unsigned long flags; 1098 1099 spin_lock_irqsave(&lockres->l_lock, flags); 1100 __lockres_clear_pending(lockres, generation, osb); 1101 spin_unlock_irqrestore(&lockres->l_lock, flags); 1102 } 1103 1104 static unsigned int lockres_set_pending(struct ocfs2_lock_res *lockres) 1105 { 1106 assert_spin_locked(&lockres->l_lock); 1107 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY)); 1108 1109 lockres_or_flags(lockres, OCFS2_LOCK_PENDING); 1110 1111 return lockres->l_pending_gen; 1112 } 1113 1114 static void ocfs2_blocking_ast(struct ocfs2_dlm_lksb *lksb, int level) 1115 { 1116 struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb); 1117 struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres); 1118 int needs_downconvert; 1119 unsigned long flags; 1120 1121 BUG_ON(level <= DLM_LOCK_NL); 1122 1123 mlog(ML_BASTS, "BAST fired for lockres %s, blocking %d, level %d, " 1124 "type %s\n", lockres->l_name, level, lockres->l_level, 1125 ocfs2_lock_type_string(lockres->l_type)); 1126 1127 /* 1128 * We can skip the bast for locks which don't enable caching - 1129 * they'll be dropped at the earliest possible time anyway. 1130 */ 1131 if (lockres->l_flags & OCFS2_LOCK_NOCACHE) 1132 return; 1133 1134 spin_lock_irqsave(&lockres->l_lock, flags); 1135 needs_downconvert = ocfs2_generic_handle_bast(lockres, level); 1136 if (needs_downconvert) 1137 ocfs2_schedule_blocked_lock(osb, lockres); 1138 spin_unlock_irqrestore(&lockres->l_lock, flags); 1139 1140 wake_up(&lockres->l_event); 1141 1142 ocfs2_wake_downconvert_thread(osb); 1143 } 1144 1145 static void ocfs2_locking_ast(struct ocfs2_dlm_lksb *lksb) 1146 { 1147 struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb); 1148 struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres); 1149 unsigned long flags; 1150 int status; 1151 1152 spin_lock_irqsave(&lockres->l_lock, flags); 1153 1154 status = ocfs2_dlm_lock_status(&lockres->l_lksb); 1155 1156 if (status == -EAGAIN) { 1157 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); 1158 goto out; 1159 } 1160 1161 if (status) { 1162 mlog(ML_ERROR, "lockres %s: lksb status value of %d!\n", 1163 lockres->l_name, status); 1164 spin_unlock_irqrestore(&lockres->l_lock, flags); 1165 return; 1166 } 1167 1168 mlog(ML_BASTS, "AST fired for lockres %s, action %d, unlock %d, " 1169 "level %d => %d\n", lockres->l_name, lockres->l_action, 1170 lockres->l_unlock_action, lockres->l_level, lockres->l_requested); 1171 1172 switch(lockres->l_action) { 1173 case OCFS2_AST_ATTACH: 1174 ocfs2_generic_handle_attach_action(lockres); 1175 lockres_clear_flags(lockres, OCFS2_LOCK_LOCAL); 1176 break; 1177 case OCFS2_AST_CONVERT: 1178 ocfs2_generic_handle_convert_action(lockres); 1179 break; 1180 case OCFS2_AST_DOWNCONVERT: 1181 ocfs2_generic_handle_downconvert_action(lockres); 1182 break; 1183 default: 1184 mlog(ML_ERROR, "lockres %s: AST fired with invalid action: %u, " 1185 "flags 0x%lx, unlock: %u\n", 1186 lockres->l_name, lockres->l_action, lockres->l_flags, 1187 lockres->l_unlock_action); 1188 BUG(); 1189 } 1190 out: 1191 /* set it to something invalid so if we get called again we 1192 * can catch it. */ 1193 lockres->l_action = OCFS2_AST_INVALID; 1194 1195 /* Did we try to cancel this lock? Clear that state */ 1196 if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) 1197 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID; 1198 1199 /* 1200 * We may have beaten the locking functions here. We certainly 1201 * know that dlm_lock() has been called :-) 1202 * Because we can't have two lock calls in flight at once, we 1203 * can use lockres->l_pending_gen. 1204 */ 1205 __lockres_clear_pending(lockres, lockres->l_pending_gen, osb); 1206 1207 wake_up(&lockres->l_event); 1208 spin_unlock_irqrestore(&lockres->l_lock, flags); 1209 } 1210 1211 static void ocfs2_unlock_ast(struct ocfs2_dlm_lksb *lksb, int error) 1212 { 1213 struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb); 1214 unsigned long flags; 1215 1216 mlog(ML_BASTS, "UNLOCK AST fired for lockres %s, action = %d\n", 1217 lockres->l_name, lockres->l_unlock_action); 1218 1219 spin_lock_irqsave(&lockres->l_lock, flags); 1220 if (error) { 1221 mlog(ML_ERROR, "Dlm passes error %d for lock %s, " 1222 "unlock_action %d\n", error, lockres->l_name, 1223 lockres->l_unlock_action); 1224 spin_unlock_irqrestore(&lockres->l_lock, flags); 1225 return; 1226 } 1227 1228 switch(lockres->l_unlock_action) { 1229 case OCFS2_UNLOCK_CANCEL_CONVERT: 1230 mlog(0, "Cancel convert success for %s\n", lockres->l_name); 1231 lockres->l_action = OCFS2_AST_INVALID; 1232 /* Downconvert thread may have requeued this lock, we 1233 * need to wake it. */ 1234 if (lockres->l_flags & OCFS2_LOCK_BLOCKED) 1235 ocfs2_wake_downconvert_thread(ocfs2_get_lockres_osb(lockres)); 1236 break; 1237 case OCFS2_UNLOCK_DROP_LOCK: 1238 lockres->l_level = DLM_LOCK_IV; 1239 break; 1240 default: 1241 BUG(); 1242 } 1243 1244 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); 1245 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID; 1246 wake_up(&lockres->l_event); 1247 spin_unlock_irqrestore(&lockres->l_lock, flags); 1248 } 1249 1250 /* 1251 * This is the filesystem locking protocol. It provides the lock handling 1252 * hooks for the underlying DLM. It has a maximum version number. 1253 * The version number allows interoperability with systems running at 1254 * the same major number and an equal or smaller minor number. 1255 * 1256 * Whenever the filesystem does new things with locks (adds or removes a 1257 * lock, orders them differently, does different things underneath a lock), 1258 * the version must be changed. The protocol is negotiated when joining 1259 * the dlm domain. A node may join the domain if its major version is 1260 * identical to all other nodes and its minor version is greater than 1261 * or equal to all other nodes. When its minor version is greater than 1262 * the other nodes, it will run at the minor version specified by the 1263 * other nodes. 1264 * 1265 * If a locking change is made that will not be compatible with older 1266 * versions, the major number must be increased and the minor version set 1267 * to zero. If a change merely adds a behavior that can be disabled when 1268 * speaking to older versions, the minor version must be increased. If a 1269 * change adds a fully backwards compatible change (eg, LVB changes that 1270 * are just ignored by older versions), the version does not need to be 1271 * updated. 1272 */ 1273 static struct ocfs2_locking_protocol lproto = { 1274 .lp_max_version = { 1275 .pv_major = OCFS2_LOCKING_PROTOCOL_MAJOR, 1276 .pv_minor = OCFS2_LOCKING_PROTOCOL_MINOR, 1277 }, 1278 .lp_lock_ast = ocfs2_locking_ast, 1279 .lp_blocking_ast = ocfs2_blocking_ast, 1280 .lp_unlock_ast = ocfs2_unlock_ast, 1281 }; 1282 1283 void ocfs2_set_locking_protocol(void) 1284 { 1285 ocfs2_stack_glue_set_max_proto_version(&lproto.lp_max_version); 1286 } 1287 1288 static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres, 1289 int convert) 1290 { 1291 unsigned long flags; 1292 1293 spin_lock_irqsave(&lockres->l_lock, flags); 1294 lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); 1295 lockres_clear_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING); 1296 if (convert) 1297 lockres->l_action = OCFS2_AST_INVALID; 1298 else 1299 lockres->l_unlock_action = OCFS2_UNLOCK_INVALID; 1300 spin_unlock_irqrestore(&lockres->l_lock, flags); 1301 1302 wake_up(&lockres->l_event); 1303 } 1304 1305 /* Note: If we detect another process working on the lock (i.e., 1306 * OCFS2_LOCK_BUSY), we'll bail out returning 0. It's up to the caller 1307 * to do the right thing in that case. 1308 */ 1309 static int ocfs2_lock_create(struct ocfs2_super *osb, 1310 struct ocfs2_lock_res *lockres, 1311 int level, 1312 u32 dlm_flags) 1313 { 1314 int ret = 0; 1315 unsigned long flags; 1316 unsigned int gen; 1317 1318 mlog(0, "lock %s, level = %d, flags = %u\n", lockres->l_name, level, 1319 dlm_flags); 1320 1321 spin_lock_irqsave(&lockres->l_lock, flags); 1322 if ((lockres->l_flags & OCFS2_LOCK_ATTACHED) || 1323 (lockres->l_flags & OCFS2_LOCK_BUSY)) { 1324 spin_unlock_irqrestore(&lockres->l_lock, flags); 1325 goto bail; 1326 } 1327 1328 lockres->l_action = OCFS2_AST_ATTACH; 1329 lockres->l_requested = level; 1330 lockres_or_flags(lockres, OCFS2_LOCK_BUSY); 1331 gen = lockres_set_pending(lockres); 1332 spin_unlock_irqrestore(&lockres->l_lock, flags); 1333 1334 ret = ocfs2_dlm_lock(osb->cconn, 1335 level, 1336 &lockres->l_lksb, 1337 dlm_flags, 1338 lockres->l_name, 1339 OCFS2_LOCK_ID_MAX_LEN - 1); 1340 lockres_clear_pending(lockres, gen, osb); 1341 if (ret) { 1342 ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres); 1343 ocfs2_recover_from_dlm_error(lockres, 1); 1344 } 1345 1346 mlog(0, "lock %s, return from ocfs2_dlm_lock\n", lockres->l_name); 1347 1348 bail: 1349 return ret; 1350 } 1351 1352 static inline int ocfs2_check_wait_flag(struct ocfs2_lock_res *lockres, 1353 int flag) 1354 { 1355 unsigned long flags; 1356 int ret; 1357 1358 spin_lock_irqsave(&lockres->l_lock, flags); 1359 ret = lockres->l_flags & flag; 1360 spin_unlock_irqrestore(&lockres->l_lock, flags); 1361 1362 return ret; 1363 } 1364 1365 static inline void ocfs2_wait_on_busy_lock(struct ocfs2_lock_res *lockres) 1366 1367 { 1368 wait_event(lockres->l_event, 1369 !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_BUSY)); 1370 } 1371 1372 static inline void ocfs2_wait_on_refreshing_lock(struct ocfs2_lock_res *lockres) 1373 1374 { 1375 wait_event(lockres->l_event, 1376 !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_REFRESHING)); 1377 } 1378 1379 /* predict what lock level we'll be dropping down to on behalf 1380 * of another node, and return true if the currently wanted 1381 * level will be compatible with it. */ 1382 static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres, 1383 int wanted) 1384 { 1385 BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED)); 1386 1387 return wanted <= ocfs2_highest_compat_lock_level(lockres->l_blocking); 1388 } 1389 1390 static void ocfs2_init_mask_waiter(struct ocfs2_mask_waiter *mw) 1391 { 1392 INIT_LIST_HEAD(&mw->mw_item); 1393 init_completion(&mw->mw_complete); 1394 ocfs2_init_start_time(mw); 1395 } 1396 1397 static int ocfs2_wait_for_mask(struct ocfs2_mask_waiter *mw) 1398 { 1399 wait_for_completion(&mw->mw_complete); 1400 /* Re-arm the completion in case we want to wait on it again */ 1401 reinit_completion(&mw->mw_complete); 1402 return mw->mw_status; 1403 } 1404 1405 static void lockres_add_mask_waiter(struct ocfs2_lock_res *lockres, 1406 struct ocfs2_mask_waiter *mw, 1407 unsigned long mask, 1408 unsigned long goal) 1409 { 1410 BUG_ON(!list_empty(&mw->mw_item)); 1411 1412 assert_spin_locked(&lockres->l_lock); 1413 1414 list_add_tail(&mw->mw_item, &lockres->l_mask_waiters); 1415 mw->mw_mask = mask; 1416 mw->mw_goal = goal; 1417 ocfs2_track_lock_wait(lockres); 1418 } 1419 1420 /* returns 0 if the mw that was removed was already satisfied, -EBUSY 1421 * if the mask still hadn't reached its goal */ 1422 static int __lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres, 1423 struct ocfs2_mask_waiter *mw) 1424 { 1425 int ret = 0; 1426 1427 assert_spin_locked(&lockres->l_lock); 1428 if (!list_empty(&mw->mw_item)) { 1429 if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal) 1430 ret = -EBUSY; 1431 1432 list_del_init(&mw->mw_item); 1433 init_completion(&mw->mw_complete); 1434 ocfs2_track_lock_wait(lockres); 1435 } 1436 1437 return ret; 1438 } 1439 1440 static int lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres, 1441 struct ocfs2_mask_waiter *mw) 1442 { 1443 unsigned long flags; 1444 int ret = 0; 1445 1446 spin_lock_irqsave(&lockres->l_lock, flags); 1447 ret = __lockres_remove_mask_waiter(lockres, mw); 1448 spin_unlock_irqrestore(&lockres->l_lock, flags); 1449 1450 return ret; 1451 1452 } 1453 1454 static int ocfs2_wait_for_mask_interruptible(struct ocfs2_mask_waiter *mw, 1455 struct ocfs2_lock_res *lockres) 1456 { 1457 int ret; 1458 1459 ret = wait_for_completion_interruptible(&mw->mw_complete); 1460 if (ret) 1461 lockres_remove_mask_waiter(lockres, mw); 1462 else 1463 ret = mw->mw_status; 1464 /* Re-arm the completion in case we want to wait on it again */ 1465 reinit_completion(&mw->mw_complete); 1466 return ret; 1467 } 1468 1469 static int __ocfs2_cluster_lock(struct ocfs2_super *osb, 1470 struct ocfs2_lock_res *lockres, 1471 int level, 1472 u32 lkm_flags, 1473 int arg_flags, 1474 int l_subclass, 1475 unsigned long caller_ip) 1476 { 1477 struct ocfs2_mask_waiter mw; 1478 int wait, catch_signals = !(osb->s_mount_opt & OCFS2_MOUNT_NOINTR); 1479 int ret = 0; /* gcc doesn't realize wait = 1 guarantees ret is set */ 1480 unsigned long flags; 1481 unsigned int gen; 1482 int noqueue_attempted = 0; 1483 int dlm_locked = 0; 1484 int kick_dc = 0; 1485 1486 if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED)) { 1487 mlog_errno(-EINVAL); 1488 return -EINVAL; 1489 } 1490 1491 ocfs2_init_mask_waiter(&mw); 1492 1493 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) 1494 lkm_flags |= DLM_LKF_VALBLK; 1495 1496 again: 1497 wait = 0; 1498 1499 spin_lock_irqsave(&lockres->l_lock, flags); 1500 1501 if (catch_signals && signal_pending(current)) { 1502 ret = -ERESTARTSYS; 1503 goto unlock; 1504 } 1505 1506 mlog_bug_on_msg(lockres->l_flags & OCFS2_LOCK_FREEING, 1507 "Cluster lock called on freeing lockres %s! flags " 1508 "0x%lx\n", lockres->l_name, lockres->l_flags); 1509 1510 /* We only compare against the currently granted level 1511 * here. If the lock is blocked waiting on a downconvert, 1512 * we'll get caught below. */ 1513 if (lockres->l_flags & OCFS2_LOCK_BUSY && 1514 level > lockres->l_level) { 1515 /* is someone sitting in dlm_lock? If so, wait on 1516 * them. */ 1517 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0); 1518 wait = 1; 1519 goto unlock; 1520 } 1521 1522 if (lockres->l_flags & OCFS2_LOCK_UPCONVERT_FINISHING) { 1523 /* 1524 * We've upconverted. If the lock now has a level we can 1525 * work with, we take it. If, however, the lock is not at the 1526 * required level, we go thru the full cycle. One way this could 1527 * happen is if a process requesting an upconvert to PR is 1528 * closely followed by another requesting upconvert to an EX. 1529 * If the process requesting EX lands here, we want it to 1530 * continue attempting to upconvert and let the process 1531 * requesting PR take the lock. 1532 * If multiple processes request upconvert to PR, the first one 1533 * here will take the lock. The others will have to go thru the 1534 * OCFS2_LOCK_BLOCKED check to ensure that there is no pending 1535 * downconvert request. 1536 */ 1537 if (level <= lockres->l_level) 1538 goto update_holders; 1539 } 1540 1541 if (lockres->l_flags & OCFS2_LOCK_BLOCKED && 1542 !ocfs2_may_continue_on_blocked_lock(lockres, level)) { 1543 /* is the lock is currently blocked on behalf of 1544 * another node */ 1545 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BLOCKED, 0); 1546 wait = 1; 1547 goto unlock; 1548 } 1549 1550 if (level > lockres->l_level) { 1551 if (noqueue_attempted > 0) { 1552 ret = -EAGAIN; 1553 goto unlock; 1554 } 1555 if (lkm_flags & DLM_LKF_NOQUEUE) 1556 noqueue_attempted = 1; 1557 1558 if (lockres->l_action != OCFS2_AST_INVALID) 1559 mlog(ML_ERROR, "lockres %s has action %u pending\n", 1560 lockres->l_name, lockres->l_action); 1561 1562 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) { 1563 lockres->l_action = OCFS2_AST_ATTACH; 1564 lkm_flags &= ~DLM_LKF_CONVERT; 1565 } else { 1566 lockres->l_action = OCFS2_AST_CONVERT; 1567 lkm_flags |= DLM_LKF_CONVERT; 1568 } 1569 1570 lockres->l_requested = level; 1571 lockres_or_flags(lockres, OCFS2_LOCK_BUSY); 1572 gen = lockres_set_pending(lockres); 1573 spin_unlock_irqrestore(&lockres->l_lock, flags); 1574 1575 BUG_ON(level == DLM_LOCK_IV); 1576 BUG_ON(level == DLM_LOCK_NL); 1577 1578 mlog(ML_BASTS, "lockres %s, convert from %d to %d\n", 1579 lockres->l_name, lockres->l_level, level); 1580 1581 /* call dlm_lock to upgrade lock now */ 1582 ret = ocfs2_dlm_lock(osb->cconn, 1583 level, 1584 &lockres->l_lksb, 1585 lkm_flags, 1586 lockres->l_name, 1587 OCFS2_LOCK_ID_MAX_LEN - 1); 1588 lockres_clear_pending(lockres, gen, osb); 1589 if (ret) { 1590 if (!(lkm_flags & DLM_LKF_NOQUEUE) || 1591 (ret != -EAGAIN)) { 1592 ocfs2_log_dlm_error("ocfs2_dlm_lock", 1593 ret, lockres); 1594 } 1595 ocfs2_recover_from_dlm_error(lockres, 1); 1596 goto out; 1597 } 1598 dlm_locked = 1; 1599 1600 mlog(0, "lock %s, successful return from ocfs2_dlm_lock\n", 1601 lockres->l_name); 1602 1603 /* At this point we've gone inside the dlm and need to 1604 * complete our work regardless. */ 1605 catch_signals = 0; 1606 1607 /* wait for busy to clear and carry on */ 1608 goto again; 1609 } 1610 1611 update_holders: 1612 /* Ok, if we get here then we're good to go. */ 1613 ocfs2_inc_holders(lockres, level); 1614 1615 ret = 0; 1616 unlock: 1617 lockres_clear_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING); 1618 1619 /* ocfs2_unblock_lock reques on seeing OCFS2_LOCK_UPCONVERT_FINISHING */ 1620 kick_dc = (lockres->l_flags & OCFS2_LOCK_BLOCKED); 1621 1622 spin_unlock_irqrestore(&lockres->l_lock, flags); 1623 if (kick_dc) 1624 ocfs2_wake_downconvert_thread(osb); 1625 out: 1626 /* 1627 * This is helping work around a lock inversion between the page lock 1628 * and dlm locks. One path holds the page lock while calling aops 1629 * which block acquiring dlm locks. The voting thread holds dlm 1630 * locks while acquiring page locks while down converting data locks. 1631 * This block is helping an aop path notice the inversion and back 1632 * off to unlock its page lock before trying the dlm lock again. 1633 */ 1634 if (wait && arg_flags & OCFS2_LOCK_NONBLOCK && 1635 mw.mw_mask & (OCFS2_LOCK_BUSY|OCFS2_LOCK_BLOCKED)) { 1636 wait = 0; 1637 spin_lock_irqsave(&lockres->l_lock, flags); 1638 if (__lockres_remove_mask_waiter(lockres, &mw)) { 1639 if (dlm_locked) 1640 lockres_or_flags(lockres, 1641 OCFS2_LOCK_NONBLOCK_FINISHED); 1642 spin_unlock_irqrestore(&lockres->l_lock, flags); 1643 ret = -EAGAIN; 1644 } else { 1645 spin_unlock_irqrestore(&lockres->l_lock, flags); 1646 goto again; 1647 } 1648 } 1649 if (wait) { 1650 ret = ocfs2_wait_for_mask(&mw); 1651 if (ret == 0) 1652 goto again; 1653 mlog_errno(ret); 1654 } 1655 ocfs2_update_lock_stats(lockres, level, &mw, ret); 1656 1657 #ifdef CONFIG_DEBUG_LOCK_ALLOC 1658 if (!ret && lockres->l_lockdep_map.key != NULL) { 1659 if (level == DLM_LOCK_PR) 1660 rwsem_acquire_read(&lockres->l_lockdep_map, l_subclass, 1661 !!(arg_flags & OCFS2_META_LOCK_NOQUEUE), 1662 caller_ip); 1663 else 1664 rwsem_acquire(&lockres->l_lockdep_map, l_subclass, 1665 !!(arg_flags & OCFS2_META_LOCK_NOQUEUE), 1666 caller_ip); 1667 } 1668 #endif 1669 return ret; 1670 } 1671 1672 static inline int ocfs2_cluster_lock(struct ocfs2_super *osb, 1673 struct ocfs2_lock_res *lockres, 1674 int level, 1675 u32 lkm_flags, 1676 int arg_flags) 1677 { 1678 return __ocfs2_cluster_lock(osb, lockres, level, lkm_flags, arg_flags, 1679 0, _RET_IP_); 1680 } 1681 1682 1683 static void __ocfs2_cluster_unlock(struct ocfs2_super *osb, 1684 struct ocfs2_lock_res *lockres, 1685 int level, 1686 unsigned long caller_ip) 1687 { 1688 unsigned long flags; 1689 1690 spin_lock_irqsave(&lockres->l_lock, flags); 1691 ocfs2_dec_holders(lockres, level); 1692 ocfs2_downconvert_on_unlock(osb, lockres); 1693 spin_unlock_irqrestore(&lockres->l_lock, flags); 1694 #ifdef CONFIG_DEBUG_LOCK_ALLOC 1695 if (lockres->l_lockdep_map.key != NULL) 1696 rwsem_release(&lockres->l_lockdep_map, caller_ip); 1697 #endif 1698 } 1699 1700 static int ocfs2_create_new_lock(struct ocfs2_super *osb, 1701 struct ocfs2_lock_res *lockres, 1702 int ex, 1703 int local) 1704 { 1705 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 1706 unsigned long flags; 1707 u32 lkm_flags = local ? DLM_LKF_LOCAL : 0; 1708 1709 spin_lock_irqsave(&lockres->l_lock, flags); 1710 BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED); 1711 lockres_or_flags(lockres, OCFS2_LOCK_LOCAL); 1712 spin_unlock_irqrestore(&lockres->l_lock, flags); 1713 1714 return ocfs2_lock_create(osb, lockres, level, lkm_flags); 1715 } 1716 1717 /* Grants us an EX lock on the data and metadata resources, skipping 1718 * the normal cluster directory lookup. Use this ONLY on newly created 1719 * inodes which other nodes can't possibly see, and which haven't been 1720 * hashed in the inode hash yet. This can give us a good performance 1721 * increase as it'll skip the network broadcast normally associated 1722 * with creating a new lock resource. */ 1723 int ocfs2_create_new_inode_locks(struct inode *inode) 1724 { 1725 int ret; 1726 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1727 1728 BUG_ON(!ocfs2_inode_is_new(inode)); 1729 1730 mlog(0, "Inode %llu\n", (unsigned long long)OCFS2_I(inode)->ip_blkno); 1731 1732 /* NOTE: That we don't increment any of the holder counts, nor 1733 * do we add anything to a journal handle. Since this is 1734 * supposed to be a new inode which the cluster doesn't know 1735 * about yet, there is no need to. As far as the LVB handling 1736 * is concerned, this is basically like acquiring an EX lock 1737 * on a resource which has an invalid one -- we'll set it 1738 * valid when we release the EX. */ 1739 1740 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_rw_lockres, 1, 1); 1741 if (ret) { 1742 mlog_errno(ret); 1743 goto bail; 1744 } 1745 1746 /* 1747 * We don't want to use DLM_LKF_LOCAL on a meta data lock as they 1748 * don't use a generation in their lock names. 1749 */ 1750 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_inode_lockres, 1, 0); 1751 if (ret) { 1752 mlog_errno(ret); 1753 goto bail; 1754 } 1755 1756 ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_open_lockres, 0, 0); 1757 if (ret) 1758 mlog_errno(ret); 1759 1760 bail: 1761 return ret; 1762 } 1763 1764 int ocfs2_rw_lock(struct inode *inode, int write) 1765 { 1766 int status, level; 1767 struct ocfs2_lock_res *lockres; 1768 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1769 1770 mlog(0, "inode %llu take %s RW lock\n", 1771 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1772 write ? "EXMODE" : "PRMODE"); 1773 1774 if (ocfs2_mount_local(osb)) 1775 return 0; 1776 1777 lockres = &OCFS2_I(inode)->ip_rw_lockres; 1778 1779 level = write ? DLM_LOCK_EX : DLM_LOCK_PR; 1780 1781 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0); 1782 if (status < 0) 1783 mlog_errno(status); 1784 1785 return status; 1786 } 1787 1788 int ocfs2_try_rw_lock(struct inode *inode, int write) 1789 { 1790 int status, level; 1791 struct ocfs2_lock_res *lockres; 1792 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1793 1794 mlog(0, "inode %llu try to take %s RW lock\n", 1795 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1796 write ? "EXMODE" : "PRMODE"); 1797 1798 if (ocfs2_mount_local(osb)) 1799 return 0; 1800 1801 lockres = &OCFS2_I(inode)->ip_rw_lockres; 1802 1803 level = write ? DLM_LOCK_EX : DLM_LOCK_PR; 1804 1805 status = ocfs2_cluster_lock(osb, lockres, level, DLM_LKF_NOQUEUE, 0); 1806 return status; 1807 } 1808 1809 void ocfs2_rw_unlock(struct inode *inode, int write) 1810 { 1811 int level = write ? DLM_LOCK_EX : DLM_LOCK_PR; 1812 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_rw_lockres; 1813 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1814 1815 mlog(0, "inode %llu drop %s RW lock\n", 1816 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1817 write ? "EXMODE" : "PRMODE"); 1818 1819 if (!ocfs2_mount_local(osb)) 1820 ocfs2_cluster_unlock(osb, lockres, level); 1821 } 1822 1823 /* 1824 * ocfs2_open_lock always get PR mode lock. 1825 */ 1826 int ocfs2_open_lock(struct inode *inode) 1827 { 1828 int status = 0; 1829 struct ocfs2_lock_res *lockres; 1830 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1831 1832 mlog(0, "inode %llu take PRMODE open lock\n", 1833 (unsigned long long)OCFS2_I(inode)->ip_blkno); 1834 1835 if (ocfs2_is_hard_readonly(osb) || ocfs2_mount_local(osb)) 1836 goto out; 1837 1838 lockres = &OCFS2_I(inode)->ip_open_lockres; 1839 1840 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_PR, 0, 0); 1841 if (status < 0) 1842 mlog_errno(status); 1843 1844 out: 1845 return status; 1846 } 1847 1848 int ocfs2_try_open_lock(struct inode *inode, int write) 1849 { 1850 int status = 0, level; 1851 struct ocfs2_lock_res *lockres; 1852 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1853 1854 mlog(0, "inode %llu try to take %s open lock\n", 1855 (unsigned long long)OCFS2_I(inode)->ip_blkno, 1856 write ? "EXMODE" : "PRMODE"); 1857 1858 if (ocfs2_is_hard_readonly(osb)) { 1859 if (write) 1860 status = -EROFS; 1861 goto out; 1862 } 1863 1864 if (ocfs2_mount_local(osb)) 1865 goto out; 1866 1867 lockres = &OCFS2_I(inode)->ip_open_lockres; 1868 1869 level = write ? DLM_LOCK_EX : DLM_LOCK_PR; 1870 1871 /* 1872 * The file system may already holding a PRMODE/EXMODE open lock. 1873 * Since we pass DLM_LKF_NOQUEUE, the request won't block waiting on 1874 * other nodes and the -EAGAIN will indicate to the caller that 1875 * this inode is still in use. 1876 */ 1877 status = ocfs2_cluster_lock(osb, lockres, level, DLM_LKF_NOQUEUE, 0); 1878 1879 out: 1880 return status; 1881 } 1882 1883 /* 1884 * ocfs2_open_unlock unlock PR and EX mode open locks. 1885 */ 1886 void ocfs2_open_unlock(struct inode *inode) 1887 { 1888 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_open_lockres; 1889 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 1890 1891 mlog(0, "inode %llu drop open lock\n", 1892 (unsigned long long)OCFS2_I(inode)->ip_blkno); 1893 1894 if (ocfs2_mount_local(osb)) 1895 goto out; 1896 1897 if(lockres->l_ro_holders) 1898 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_PR); 1899 if(lockres->l_ex_holders) 1900 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX); 1901 1902 out: 1903 return; 1904 } 1905 1906 static int ocfs2_flock_handle_signal(struct ocfs2_lock_res *lockres, 1907 int level) 1908 { 1909 int ret; 1910 struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres); 1911 unsigned long flags; 1912 struct ocfs2_mask_waiter mw; 1913 1914 ocfs2_init_mask_waiter(&mw); 1915 1916 retry_cancel: 1917 spin_lock_irqsave(&lockres->l_lock, flags); 1918 if (lockres->l_flags & OCFS2_LOCK_BUSY) { 1919 ret = ocfs2_prepare_cancel_convert(osb, lockres); 1920 if (ret) { 1921 spin_unlock_irqrestore(&lockres->l_lock, flags); 1922 ret = ocfs2_cancel_convert(osb, lockres); 1923 if (ret < 0) { 1924 mlog_errno(ret); 1925 goto out; 1926 } 1927 goto retry_cancel; 1928 } 1929 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0); 1930 spin_unlock_irqrestore(&lockres->l_lock, flags); 1931 1932 ocfs2_wait_for_mask(&mw); 1933 goto retry_cancel; 1934 } 1935 1936 ret = -ERESTARTSYS; 1937 /* 1938 * We may still have gotten the lock, in which case there's no 1939 * point to restarting the syscall. 1940 */ 1941 if (lockres->l_level == level) 1942 ret = 0; 1943 1944 mlog(0, "Cancel returning %d. flags: 0x%lx, level: %d, act: %d\n", ret, 1945 lockres->l_flags, lockres->l_level, lockres->l_action); 1946 1947 spin_unlock_irqrestore(&lockres->l_lock, flags); 1948 1949 out: 1950 return ret; 1951 } 1952 1953 /* 1954 * ocfs2_file_lock() and ocfs2_file_unlock() map to a single pair of 1955 * flock() calls. The locking approach this requires is sufficiently 1956 * different from all other cluster lock types that we implement a 1957 * separate path to the "low-level" dlm calls. In particular: 1958 * 1959 * - No optimization of lock levels is done - we take at exactly 1960 * what's been requested. 1961 * 1962 * - No lock caching is employed. We immediately downconvert to 1963 * no-lock at unlock time. This also means flock locks never go on 1964 * the blocking list). 1965 * 1966 * - Since userspace can trivially deadlock itself with flock, we make 1967 * sure to allow cancellation of a misbehaving applications flock() 1968 * request. 1969 * 1970 * - Access to any flock lockres doesn't require concurrency, so we 1971 * can simplify the code by requiring the caller to guarantee 1972 * serialization of dlmglue flock calls. 1973 */ 1974 int ocfs2_file_lock(struct file *file, int ex, int trylock) 1975 { 1976 int ret, level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 1977 unsigned int lkm_flags = trylock ? DLM_LKF_NOQUEUE : 0; 1978 unsigned long flags; 1979 struct ocfs2_file_private *fp = file->private_data; 1980 struct ocfs2_lock_res *lockres = &fp->fp_flock; 1981 struct ocfs2_super *osb = OCFS2_SB(file->f_mapping->host->i_sb); 1982 struct ocfs2_mask_waiter mw; 1983 1984 ocfs2_init_mask_waiter(&mw); 1985 1986 if ((lockres->l_flags & OCFS2_LOCK_BUSY) || 1987 (lockres->l_level > DLM_LOCK_NL)) { 1988 mlog(ML_ERROR, 1989 "File lock \"%s\" has busy or locked state: flags: 0x%lx, " 1990 "level: %u\n", lockres->l_name, lockres->l_flags, 1991 lockres->l_level); 1992 return -EINVAL; 1993 } 1994 1995 spin_lock_irqsave(&lockres->l_lock, flags); 1996 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) { 1997 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0); 1998 spin_unlock_irqrestore(&lockres->l_lock, flags); 1999 2000 /* 2001 * Get the lock at NLMODE to start - that way we 2002 * can cancel the upconvert request if need be. 2003 */ 2004 ret = ocfs2_lock_create(osb, lockres, DLM_LOCK_NL, 0); 2005 if (ret < 0) { 2006 mlog_errno(ret); 2007 goto out; 2008 } 2009 2010 ret = ocfs2_wait_for_mask(&mw); 2011 if (ret) { 2012 mlog_errno(ret); 2013 goto out; 2014 } 2015 spin_lock_irqsave(&lockres->l_lock, flags); 2016 } 2017 2018 lockres->l_action = OCFS2_AST_CONVERT; 2019 lkm_flags |= DLM_LKF_CONVERT; 2020 lockres->l_requested = level; 2021 lockres_or_flags(lockres, OCFS2_LOCK_BUSY); 2022 2023 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0); 2024 spin_unlock_irqrestore(&lockres->l_lock, flags); 2025 2026 ret = ocfs2_dlm_lock(osb->cconn, level, &lockres->l_lksb, lkm_flags, 2027 lockres->l_name, OCFS2_LOCK_ID_MAX_LEN - 1); 2028 if (ret) { 2029 if (!trylock || (ret != -EAGAIN)) { 2030 ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres); 2031 ret = -EINVAL; 2032 } 2033 2034 ocfs2_recover_from_dlm_error(lockres, 1); 2035 lockres_remove_mask_waiter(lockres, &mw); 2036 goto out; 2037 } 2038 2039 ret = ocfs2_wait_for_mask_interruptible(&mw, lockres); 2040 if (ret == -ERESTARTSYS) { 2041 /* 2042 * Userspace can cause deadlock itself with 2043 * flock(). Current behavior locally is to allow the 2044 * deadlock, but abort the system call if a signal is 2045 * received. We follow this example, otherwise a 2046 * poorly written program could sit in kernel until 2047 * reboot. 2048 * 2049 * Handling this is a bit more complicated for Ocfs2 2050 * though. We can't exit this function with an 2051 * outstanding lock request, so a cancel convert is 2052 * required. We intentionally overwrite 'ret' - if the 2053 * cancel fails and the lock was granted, it's easier 2054 * to just bubble success back up to the user. 2055 */ 2056 ret = ocfs2_flock_handle_signal(lockres, level); 2057 } else if (!ret && (level > lockres->l_level)) { 2058 /* Trylock failed asynchronously */ 2059 BUG_ON(!trylock); 2060 ret = -EAGAIN; 2061 } 2062 2063 out: 2064 2065 mlog(0, "Lock: \"%s\" ex: %d, trylock: %d, returns: %d\n", 2066 lockres->l_name, ex, trylock, ret); 2067 return ret; 2068 } 2069 2070 void ocfs2_file_unlock(struct file *file) 2071 { 2072 int ret; 2073 unsigned int gen; 2074 unsigned long flags; 2075 struct ocfs2_file_private *fp = file->private_data; 2076 struct ocfs2_lock_res *lockres = &fp->fp_flock; 2077 struct ocfs2_super *osb = OCFS2_SB(file->f_mapping->host->i_sb); 2078 struct ocfs2_mask_waiter mw; 2079 2080 ocfs2_init_mask_waiter(&mw); 2081 2082 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) 2083 return; 2084 2085 if (lockres->l_level == DLM_LOCK_NL) 2086 return; 2087 2088 mlog(0, "Unlock: \"%s\" flags: 0x%lx, level: %d, act: %d\n", 2089 lockres->l_name, lockres->l_flags, lockres->l_level, 2090 lockres->l_action); 2091 2092 spin_lock_irqsave(&lockres->l_lock, flags); 2093 /* 2094 * Fake a blocking ast for the downconvert code. 2095 */ 2096 lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED); 2097 lockres->l_blocking = DLM_LOCK_EX; 2098 2099 gen = ocfs2_prepare_downconvert(lockres, DLM_LOCK_NL); 2100 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0); 2101 spin_unlock_irqrestore(&lockres->l_lock, flags); 2102 2103 ret = ocfs2_downconvert_lock(osb, lockres, DLM_LOCK_NL, 0, gen); 2104 if (ret) { 2105 mlog_errno(ret); 2106 return; 2107 } 2108 2109 ret = ocfs2_wait_for_mask(&mw); 2110 if (ret) 2111 mlog_errno(ret); 2112 } 2113 2114 static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb, 2115 struct ocfs2_lock_res *lockres) 2116 { 2117 int kick = 0; 2118 2119 /* If we know that another node is waiting on our lock, kick 2120 * the downconvert thread * pre-emptively when we reach a release 2121 * condition. */ 2122 if (lockres->l_flags & OCFS2_LOCK_BLOCKED) { 2123 switch(lockres->l_blocking) { 2124 case DLM_LOCK_EX: 2125 if (!lockres->l_ex_holders && !lockres->l_ro_holders) 2126 kick = 1; 2127 break; 2128 case DLM_LOCK_PR: 2129 if (!lockres->l_ex_holders) 2130 kick = 1; 2131 break; 2132 default: 2133 BUG(); 2134 } 2135 } 2136 2137 if (kick) 2138 ocfs2_wake_downconvert_thread(osb); 2139 } 2140 2141 #define OCFS2_SEC_BITS 34 2142 #define OCFS2_SEC_SHIFT (64 - OCFS2_SEC_BITS) 2143 #define OCFS2_NSEC_MASK ((1ULL << OCFS2_SEC_SHIFT) - 1) 2144 2145 /* LVB only has room for 64 bits of time here so we pack it for 2146 * now. */ 2147 static u64 ocfs2_pack_timespec(struct timespec64 *spec) 2148 { 2149 u64 res; 2150 u64 sec = clamp_t(time64_t, spec->tv_sec, 0, 0x3ffffffffull); 2151 u32 nsec = spec->tv_nsec; 2152 2153 res = (sec << OCFS2_SEC_SHIFT) | (nsec & OCFS2_NSEC_MASK); 2154 2155 return res; 2156 } 2157 2158 /* Call this with the lockres locked. I am reasonably sure we don't 2159 * need ip_lock in this function as anyone who would be changing those 2160 * values is supposed to be blocked in ocfs2_inode_lock right now. */ 2161 static void __ocfs2_stuff_meta_lvb(struct inode *inode) 2162 { 2163 struct ocfs2_inode_info *oi = OCFS2_I(inode); 2164 struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres; 2165 struct ocfs2_meta_lvb *lvb; 2166 2167 lvb = ocfs2_dlm_lvb(&lockres->l_lksb); 2168 2169 /* 2170 * Invalidate the LVB of a deleted inode - this way other 2171 * nodes are forced to go to disk and discover the new inode 2172 * status. 2173 */ 2174 if (oi->ip_flags & OCFS2_INODE_DELETED) { 2175 lvb->lvb_version = 0; 2176 goto out; 2177 } 2178 2179 lvb->lvb_version = OCFS2_LVB_VERSION; 2180 lvb->lvb_isize = cpu_to_be64(i_size_read(inode)); 2181 lvb->lvb_iclusters = cpu_to_be32(oi->ip_clusters); 2182 lvb->lvb_iuid = cpu_to_be32(i_uid_read(inode)); 2183 lvb->lvb_igid = cpu_to_be32(i_gid_read(inode)); 2184 lvb->lvb_imode = cpu_to_be16(inode->i_mode); 2185 lvb->lvb_inlink = cpu_to_be16(inode->i_nlink); 2186 lvb->lvb_iatime_packed = 2187 cpu_to_be64(ocfs2_pack_timespec(&inode->i_atime)); 2188 lvb->lvb_ictime_packed = 2189 cpu_to_be64(ocfs2_pack_timespec(&inode->i_ctime)); 2190 lvb->lvb_imtime_packed = 2191 cpu_to_be64(ocfs2_pack_timespec(&inode->i_mtime)); 2192 lvb->lvb_iattr = cpu_to_be32(oi->ip_attr); 2193 lvb->lvb_idynfeatures = cpu_to_be16(oi->ip_dyn_features); 2194 lvb->lvb_igeneration = cpu_to_be32(inode->i_generation); 2195 2196 out: 2197 mlog_meta_lvb(0, lockres); 2198 } 2199 2200 static void ocfs2_unpack_timespec(struct timespec64 *spec, 2201 u64 packed_time) 2202 { 2203 spec->tv_sec = packed_time >> OCFS2_SEC_SHIFT; 2204 spec->tv_nsec = packed_time & OCFS2_NSEC_MASK; 2205 } 2206 2207 static void ocfs2_refresh_inode_from_lvb(struct inode *inode) 2208 { 2209 struct ocfs2_inode_info *oi = OCFS2_I(inode); 2210 struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres; 2211 struct ocfs2_meta_lvb *lvb; 2212 2213 mlog_meta_lvb(0, lockres); 2214 2215 lvb = ocfs2_dlm_lvb(&lockres->l_lksb); 2216 2217 /* We're safe here without the lockres lock... */ 2218 spin_lock(&oi->ip_lock); 2219 oi->ip_clusters = be32_to_cpu(lvb->lvb_iclusters); 2220 i_size_write(inode, be64_to_cpu(lvb->lvb_isize)); 2221 2222 oi->ip_attr = be32_to_cpu(lvb->lvb_iattr); 2223 oi->ip_dyn_features = be16_to_cpu(lvb->lvb_idynfeatures); 2224 ocfs2_set_inode_flags(inode); 2225 2226 /* fast-symlinks are a special case */ 2227 if (S_ISLNK(inode->i_mode) && !oi->ip_clusters) 2228 inode->i_blocks = 0; 2229 else 2230 inode->i_blocks = ocfs2_inode_sector_count(inode); 2231 2232 i_uid_write(inode, be32_to_cpu(lvb->lvb_iuid)); 2233 i_gid_write(inode, be32_to_cpu(lvb->lvb_igid)); 2234 inode->i_mode = be16_to_cpu(lvb->lvb_imode); 2235 set_nlink(inode, be16_to_cpu(lvb->lvb_inlink)); 2236 ocfs2_unpack_timespec(&inode->i_atime, 2237 be64_to_cpu(lvb->lvb_iatime_packed)); 2238 ocfs2_unpack_timespec(&inode->i_mtime, 2239 be64_to_cpu(lvb->lvb_imtime_packed)); 2240 ocfs2_unpack_timespec(&inode->i_ctime, 2241 be64_to_cpu(lvb->lvb_ictime_packed)); 2242 spin_unlock(&oi->ip_lock); 2243 } 2244 2245 static inline int ocfs2_meta_lvb_is_trustable(struct inode *inode, 2246 struct ocfs2_lock_res *lockres) 2247 { 2248 struct ocfs2_meta_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb); 2249 2250 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) 2251 && lvb->lvb_version == OCFS2_LVB_VERSION 2252 && be32_to_cpu(lvb->lvb_igeneration) == inode->i_generation) 2253 return 1; 2254 return 0; 2255 } 2256 2257 /* Determine whether a lock resource needs to be refreshed, and 2258 * arbitrate who gets to refresh it. 2259 * 2260 * 0 means no refresh needed. 2261 * 2262 * > 0 means you need to refresh this and you MUST call 2263 * ocfs2_complete_lock_res_refresh afterwards. */ 2264 static int ocfs2_should_refresh_lock_res(struct ocfs2_lock_res *lockres) 2265 { 2266 unsigned long flags; 2267 int status = 0; 2268 2269 refresh_check: 2270 spin_lock_irqsave(&lockres->l_lock, flags); 2271 if (!(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) { 2272 spin_unlock_irqrestore(&lockres->l_lock, flags); 2273 goto bail; 2274 } 2275 2276 if (lockres->l_flags & OCFS2_LOCK_REFRESHING) { 2277 spin_unlock_irqrestore(&lockres->l_lock, flags); 2278 2279 ocfs2_wait_on_refreshing_lock(lockres); 2280 goto refresh_check; 2281 } 2282 2283 /* Ok, I'll be the one to refresh this lock. */ 2284 lockres_or_flags(lockres, OCFS2_LOCK_REFRESHING); 2285 spin_unlock_irqrestore(&lockres->l_lock, flags); 2286 2287 status = 1; 2288 bail: 2289 mlog(0, "status %d\n", status); 2290 return status; 2291 } 2292 2293 /* If status is non zero, I'll mark it as not being in refresh 2294 * anymroe, but i won't clear the needs refresh flag. */ 2295 static inline void ocfs2_complete_lock_res_refresh(struct ocfs2_lock_res *lockres, 2296 int status) 2297 { 2298 unsigned long flags; 2299 2300 spin_lock_irqsave(&lockres->l_lock, flags); 2301 lockres_clear_flags(lockres, OCFS2_LOCK_REFRESHING); 2302 if (!status) 2303 lockres_clear_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH); 2304 spin_unlock_irqrestore(&lockres->l_lock, flags); 2305 2306 wake_up(&lockres->l_event); 2307 } 2308 2309 /* may or may not return a bh if it went to disk. */ 2310 static int ocfs2_inode_lock_update(struct inode *inode, 2311 struct buffer_head **bh) 2312 { 2313 int status = 0; 2314 struct ocfs2_inode_info *oi = OCFS2_I(inode); 2315 struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres; 2316 struct ocfs2_dinode *fe; 2317 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 2318 2319 if (ocfs2_mount_local(osb)) 2320 goto bail; 2321 2322 spin_lock(&oi->ip_lock); 2323 if (oi->ip_flags & OCFS2_INODE_DELETED) { 2324 mlog(0, "Orphaned inode %llu was deleted while we " 2325 "were waiting on a lock. ip_flags = 0x%x\n", 2326 (unsigned long long)oi->ip_blkno, oi->ip_flags); 2327 spin_unlock(&oi->ip_lock); 2328 status = -ENOENT; 2329 goto bail; 2330 } 2331 spin_unlock(&oi->ip_lock); 2332 2333 if (!ocfs2_should_refresh_lock_res(lockres)) 2334 goto bail; 2335 2336 /* This will discard any caching information we might have had 2337 * for the inode metadata. */ 2338 ocfs2_metadata_cache_purge(INODE_CACHE(inode)); 2339 2340 ocfs2_extent_map_trunc(inode, 0); 2341 2342 if (ocfs2_meta_lvb_is_trustable(inode, lockres)) { 2343 mlog(0, "Trusting LVB on inode %llu\n", 2344 (unsigned long long)oi->ip_blkno); 2345 ocfs2_refresh_inode_from_lvb(inode); 2346 } else { 2347 /* Boo, we have to go to disk. */ 2348 /* read bh, cast, ocfs2_refresh_inode */ 2349 status = ocfs2_read_inode_block(inode, bh); 2350 if (status < 0) { 2351 mlog_errno(status); 2352 goto bail_refresh; 2353 } 2354 fe = (struct ocfs2_dinode *) (*bh)->b_data; 2355 2356 /* This is a good chance to make sure we're not 2357 * locking an invalid object. ocfs2_read_inode_block() 2358 * already checked that the inode block is sane. 2359 * 2360 * We bug on a stale inode here because we checked 2361 * above whether it was wiped from disk. The wiping 2362 * node provides a guarantee that we receive that 2363 * message and can mark the inode before dropping any 2364 * locks associated with it. */ 2365 mlog_bug_on_msg(inode->i_generation != 2366 le32_to_cpu(fe->i_generation), 2367 "Invalid dinode %llu disk generation: %u " 2368 "inode->i_generation: %u\n", 2369 (unsigned long long)oi->ip_blkno, 2370 le32_to_cpu(fe->i_generation), 2371 inode->i_generation); 2372 mlog_bug_on_msg(le64_to_cpu(fe->i_dtime) || 2373 !(fe->i_flags & cpu_to_le32(OCFS2_VALID_FL)), 2374 "Stale dinode %llu dtime: %llu flags: 0x%x\n", 2375 (unsigned long long)oi->ip_blkno, 2376 (unsigned long long)le64_to_cpu(fe->i_dtime), 2377 le32_to_cpu(fe->i_flags)); 2378 2379 ocfs2_refresh_inode(inode, fe); 2380 ocfs2_track_lock_refresh(lockres); 2381 } 2382 2383 status = 0; 2384 bail_refresh: 2385 ocfs2_complete_lock_res_refresh(lockres, status); 2386 bail: 2387 return status; 2388 } 2389 2390 static int ocfs2_assign_bh(struct inode *inode, 2391 struct buffer_head **ret_bh, 2392 struct buffer_head *passed_bh) 2393 { 2394 int status; 2395 2396 if (passed_bh) { 2397 /* Ok, the update went to disk for us, use the 2398 * returned bh. */ 2399 *ret_bh = passed_bh; 2400 get_bh(*ret_bh); 2401 2402 return 0; 2403 } 2404 2405 status = ocfs2_read_inode_block(inode, ret_bh); 2406 if (status < 0) 2407 mlog_errno(status); 2408 2409 return status; 2410 } 2411 2412 /* 2413 * returns < 0 error if the callback will never be called, otherwise 2414 * the result of the lock will be communicated via the callback. 2415 */ 2416 int ocfs2_inode_lock_full_nested(struct inode *inode, 2417 struct buffer_head **ret_bh, 2418 int ex, 2419 int arg_flags, 2420 int subclass) 2421 { 2422 int status, level, acquired; 2423 u32 dlm_flags; 2424 struct ocfs2_lock_res *lockres = NULL; 2425 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 2426 struct buffer_head *local_bh = NULL; 2427 2428 mlog(0, "inode %llu, take %s META lock\n", 2429 (unsigned long long)OCFS2_I(inode)->ip_blkno, 2430 ex ? "EXMODE" : "PRMODE"); 2431 2432 status = 0; 2433 acquired = 0; 2434 /* We'll allow faking a readonly metadata lock for 2435 * rodevices. */ 2436 if (ocfs2_is_hard_readonly(osb)) { 2437 if (ex) 2438 status = -EROFS; 2439 goto getbh; 2440 } 2441 2442 if ((arg_flags & OCFS2_META_LOCK_GETBH) || 2443 ocfs2_mount_local(osb)) 2444 goto update; 2445 2446 if (!(arg_flags & OCFS2_META_LOCK_RECOVERY)) 2447 ocfs2_wait_for_recovery(osb); 2448 2449 lockres = &OCFS2_I(inode)->ip_inode_lockres; 2450 level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 2451 dlm_flags = 0; 2452 if (arg_flags & OCFS2_META_LOCK_NOQUEUE) 2453 dlm_flags |= DLM_LKF_NOQUEUE; 2454 2455 status = __ocfs2_cluster_lock(osb, lockres, level, dlm_flags, 2456 arg_flags, subclass, _RET_IP_); 2457 if (status < 0) { 2458 if (status != -EAGAIN) 2459 mlog_errno(status); 2460 goto bail; 2461 } 2462 2463 /* Notify the error cleanup path to drop the cluster lock. */ 2464 acquired = 1; 2465 2466 /* We wait twice because a node may have died while we were in 2467 * the lower dlm layers. The second time though, we've 2468 * committed to owning this lock so we don't allow signals to 2469 * abort the operation. */ 2470 if (!(arg_flags & OCFS2_META_LOCK_RECOVERY)) 2471 ocfs2_wait_for_recovery(osb); 2472 2473 update: 2474 /* 2475 * We only see this flag if we're being called from 2476 * ocfs2_read_locked_inode(). It means we're locking an inode 2477 * which hasn't been populated yet, so clear the refresh flag 2478 * and let the caller handle it. 2479 */ 2480 if (inode->i_state & I_NEW) { 2481 status = 0; 2482 if (lockres) 2483 ocfs2_complete_lock_res_refresh(lockres, 0); 2484 goto bail; 2485 } 2486 2487 /* This is fun. The caller may want a bh back, or it may 2488 * not. ocfs2_inode_lock_update definitely wants one in, but 2489 * may or may not read one, depending on what's in the 2490 * LVB. The result of all of this is that we've *only* gone to 2491 * disk if we have to, so the complexity is worthwhile. */ 2492 status = ocfs2_inode_lock_update(inode, &local_bh); 2493 if (status < 0) { 2494 if (status != -ENOENT) 2495 mlog_errno(status); 2496 goto bail; 2497 } 2498 getbh: 2499 if (ret_bh) { 2500 status = ocfs2_assign_bh(inode, ret_bh, local_bh); 2501 if (status < 0) { 2502 mlog_errno(status); 2503 goto bail; 2504 } 2505 } 2506 2507 bail: 2508 if (status < 0) { 2509 if (ret_bh && (*ret_bh)) { 2510 brelse(*ret_bh); 2511 *ret_bh = NULL; 2512 } 2513 if (acquired) 2514 ocfs2_inode_unlock(inode, ex); 2515 } 2516 2517 brelse(local_bh); 2518 return status; 2519 } 2520 2521 /* 2522 * This is working around a lock inversion between tasks acquiring DLM 2523 * locks while holding a page lock and the downconvert thread which 2524 * blocks dlm lock acquiry while acquiring page locks. 2525 * 2526 * ** These _with_page variantes are only intended to be called from aop 2527 * methods that hold page locks and return a very specific *positive* error 2528 * code that aop methods pass up to the VFS -- test for errors with != 0. ** 2529 * 2530 * The DLM is called such that it returns -EAGAIN if it would have 2531 * blocked waiting for the downconvert thread. In that case we unlock 2532 * our page so the downconvert thread can make progress. Once we've 2533 * done this we have to return AOP_TRUNCATED_PAGE so the aop method 2534 * that called us can bubble that back up into the VFS who will then 2535 * immediately retry the aop call. 2536 */ 2537 int ocfs2_inode_lock_with_page(struct inode *inode, 2538 struct buffer_head **ret_bh, 2539 int ex, 2540 struct page *page) 2541 { 2542 int ret; 2543 2544 ret = ocfs2_inode_lock_full(inode, ret_bh, ex, OCFS2_LOCK_NONBLOCK); 2545 if (ret == -EAGAIN) { 2546 unlock_page(page); 2547 /* 2548 * If we can't get inode lock immediately, we should not return 2549 * directly here, since this will lead to a softlockup problem. 2550 * The method is to get a blocking lock and immediately unlock 2551 * before returning, this can avoid CPU resource waste due to 2552 * lots of retries, and benefits fairness in getting lock. 2553 */ 2554 if (ocfs2_inode_lock(inode, ret_bh, ex) == 0) 2555 ocfs2_inode_unlock(inode, ex); 2556 ret = AOP_TRUNCATED_PAGE; 2557 } 2558 2559 return ret; 2560 } 2561 2562 int ocfs2_inode_lock_atime(struct inode *inode, 2563 struct vfsmount *vfsmnt, 2564 int *level, int wait) 2565 { 2566 int ret; 2567 2568 if (wait) 2569 ret = ocfs2_inode_lock(inode, NULL, 0); 2570 else 2571 ret = ocfs2_try_inode_lock(inode, NULL, 0); 2572 2573 if (ret < 0) { 2574 if (ret != -EAGAIN) 2575 mlog_errno(ret); 2576 return ret; 2577 } 2578 2579 /* 2580 * If we should update atime, we will get EX lock, 2581 * otherwise we just get PR lock. 2582 */ 2583 if (ocfs2_should_update_atime(inode, vfsmnt)) { 2584 struct buffer_head *bh = NULL; 2585 2586 ocfs2_inode_unlock(inode, 0); 2587 if (wait) 2588 ret = ocfs2_inode_lock(inode, &bh, 1); 2589 else 2590 ret = ocfs2_try_inode_lock(inode, &bh, 1); 2591 2592 if (ret < 0) { 2593 if (ret != -EAGAIN) 2594 mlog_errno(ret); 2595 return ret; 2596 } 2597 *level = 1; 2598 if (ocfs2_should_update_atime(inode, vfsmnt)) 2599 ocfs2_update_inode_atime(inode, bh); 2600 brelse(bh); 2601 } else 2602 *level = 0; 2603 2604 return ret; 2605 } 2606 2607 void ocfs2_inode_unlock(struct inode *inode, 2608 int ex) 2609 { 2610 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 2611 struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_inode_lockres; 2612 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 2613 2614 mlog(0, "inode %llu drop %s META lock\n", 2615 (unsigned long long)OCFS2_I(inode)->ip_blkno, 2616 ex ? "EXMODE" : "PRMODE"); 2617 2618 if (!ocfs2_is_hard_readonly(osb) && 2619 !ocfs2_mount_local(osb)) 2620 ocfs2_cluster_unlock(osb, lockres, level); 2621 } 2622 2623 /* 2624 * This _tracker variantes are introduced to deal with the recursive cluster 2625 * locking issue. The idea is to keep track of a lock holder on the stack of 2626 * the current process. If there's a lock holder on the stack, we know the 2627 * task context is already protected by cluster locking. Currently, they're 2628 * used in some VFS entry routines. 2629 * 2630 * return < 0 on error, return == 0 if there's no lock holder on the stack 2631 * before this call, return == 1 if this call would be a recursive locking. 2632 * return == -1 if this lock attempt will cause an upgrade which is forbidden. 2633 * 2634 * When taking lock levels into account,we face some different situations. 2635 * 2636 * 1. no lock is held 2637 * In this case, just lock the inode as requested and return 0 2638 * 2639 * 2. We are holding a lock 2640 * For this situation, things diverges into several cases 2641 * 2642 * wanted holding what to do 2643 * ex ex see 2.1 below 2644 * ex pr see 2.2 below 2645 * pr ex see 2.1 below 2646 * pr pr see 2.1 below 2647 * 2648 * 2.1 lock level that is been held is compatible 2649 * with the wanted level, so no lock action will be tacken. 2650 * 2651 * 2.2 Otherwise, an upgrade is needed, but it is forbidden. 2652 * 2653 * Reason why upgrade within a process is forbidden is that 2654 * lock upgrade may cause dead lock. The following illustrates 2655 * how it happens. 2656 * 2657 * thread on node1 thread on node2 2658 * ocfs2_inode_lock_tracker(ex=0) 2659 * 2660 * <====== ocfs2_inode_lock_tracker(ex=1) 2661 * 2662 * ocfs2_inode_lock_tracker(ex=1) 2663 */ 2664 int ocfs2_inode_lock_tracker(struct inode *inode, 2665 struct buffer_head **ret_bh, 2666 int ex, 2667 struct ocfs2_lock_holder *oh) 2668 { 2669 int status = 0; 2670 struct ocfs2_lock_res *lockres; 2671 struct ocfs2_lock_holder *tmp_oh; 2672 struct pid *pid = task_pid(current); 2673 2674 2675 lockres = &OCFS2_I(inode)->ip_inode_lockres; 2676 tmp_oh = ocfs2_pid_holder(lockres, pid); 2677 2678 if (!tmp_oh) { 2679 /* 2680 * This corresponds to the case 1. 2681 * We haven't got any lock before. 2682 */ 2683 status = ocfs2_inode_lock_full(inode, ret_bh, ex, 0); 2684 if (status < 0) { 2685 if (status != -ENOENT) 2686 mlog_errno(status); 2687 return status; 2688 } 2689 2690 oh->oh_ex = ex; 2691 ocfs2_add_holder(lockres, oh); 2692 return 0; 2693 } 2694 2695 if (unlikely(ex && !tmp_oh->oh_ex)) { 2696 /* 2697 * case 2.2 upgrade may cause dead lock, forbid it. 2698 */ 2699 mlog(ML_ERROR, "Recursive locking is not permitted to " 2700 "upgrade to EX level from PR level.\n"); 2701 dump_stack(); 2702 return -EINVAL; 2703 } 2704 2705 /* 2706 * case 2.1 OCFS2_META_LOCK_GETBH flag make ocfs2_inode_lock_full. 2707 * ignore the lock level and just update it. 2708 */ 2709 if (ret_bh) { 2710 status = ocfs2_inode_lock_full(inode, ret_bh, ex, 2711 OCFS2_META_LOCK_GETBH); 2712 if (status < 0) { 2713 if (status != -ENOENT) 2714 mlog_errno(status); 2715 return status; 2716 } 2717 } 2718 return tmp_oh ? 1 : 0; 2719 } 2720 2721 void ocfs2_inode_unlock_tracker(struct inode *inode, 2722 int ex, 2723 struct ocfs2_lock_holder *oh, 2724 int had_lock) 2725 { 2726 struct ocfs2_lock_res *lockres; 2727 2728 lockres = &OCFS2_I(inode)->ip_inode_lockres; 2729 /* had_lock means that the currect process already takes the cluster 2730 * lock previously. 2731 * If had_lock is 1, we have nothing to do here. 2732 * If had_lock is 0, we will release the lock. 2733 */ 2734 if (!had_lock) { 2735 ocfs2_inode_unlock(inode, oh->oh_ex); 2736 ocfs2_remove_holder(lockres, oh); 2737 } 2738 } 2739 2740 int ocfs2_orphan_scan_lock(struct ocfs2_super *osb, u32 *seqno) 2741 { 2742 struct ocfs2_lock_res *lockres; 2743 struct ocfs2_orphan_scan_lvb *lvb; 2744 int status = 0; 2745 2746 if (ocfs2_is_hard_readonly(osb)) 2747 return -EROFS; 2748 2749 if (ocfs2_mount_local(osb)) 2750 return 0; 2751 2752 lockres = &osb->osb_orphan_scan.os_lockres; 2753 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, 0, 0); 2754 if (status < 0) 2755 return status; 2756 2757 lvb = ocfs2_dlm_lvb(&lockres->l_lksb); 2758 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) && 2759 lvb->lvb_version == OCFS2_ORPHAN_LVB_VERSION) 2760 *seqno = be32_to_cpu(lvb->lvb_os_seqno); 2761 else 2762 *seqno = osb->osb_orphan_scan.os_seqno + 1; 2763 2764 return status; 2765 } 2766 2767 void ocfs2_orphan_scan_unlock(struct ocfs2_super *osb, u32 seqno) 2768 { 2769 struct ocfs2_lock_res *lockres; 2770 struct ocfs2_orphan_scan_lvb *lvb; 2771 2772 if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb)) { 2773 lockres = &osb->osb_orphan_scan.os_lockres; 2774 lvb = ocfs2_dlm_lvb(&lockres->l_lksb); 2775 lvb->lvb_version = OCFS2_ORPHAN_LVB_VERSION; 2776 lvb->lvb_os_seqno = cpu_to_be32(seqno); 2777 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX); 2778 } 2779 } 2780 2781 int ocfs2_super_lock(struct ocfs2_super *osb, 2782 int ex) 2783 { 2784 int status = 0; 2785 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 2786 struct ocfs2_lock_res *lockres = &osb->osb_super_lockres; 2787 2788 if (ocfs2_is_hard_readonly(osb)) 2789 return -EROFS; 2790 2791 if (ocfs2_mount_local(osb)) 2792 goto bail; 2793 2794 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0); 2795 if (status < 0) { 2796 mlog_errno(status); 2797 goto bail; 2798 } 2799 2800 /* The super block lock path is really in the best position to 2801 * know when resources covered by the lock need to be 2802 * refreshed, so we do it here. Of course, making sense of 2803 * everything is up to the caller :) */ 2804 status = ocfs2_should_refresh_lock_res(lockres); 2805 if (status) { 2806 status = ocfs2_refresh_slot_info(osb); 2807 2808 ocfs2_complete_lock_res_refresh(lockres, status); 2809 2810 if (status < 0) { 2811 ocfs2_cluster_unlock(osb, lockres, level); 2812 mlog_errno(status); 2813 } 2814 ocfs2_track_lock_refresh(lockres); 2815 } 2816 bail: 2817 return status; 2818 } 2819 2820 void ocfs2_super_unlock(struct ocfs2_super *osb, 2821 int ex) 2822 { 2823 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 2824 struct ocfs2_lock_res *lockres = &osb->osb_super_lockres; 2825 2826 if (!ocfs2_mount_local(osb)) 2827 ocfs2_cluster_unlock(osb, lockres, level); 2828 } 2829 2830 int ocfs2_rename_lock(struct ocfs2_super *osb) 2831 { 2832 int status; 2833 struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres; 2834 2835 if (ocfs2_is_hard_readonly(osb)) 2836 return -EROFS; 2837 2838 if (ocfs2_mount_local(osb)) 2839 return 0; 2840 2841 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, 0, 0); 2842 if (status < 0) 2843 mlog_errno(status); 2844 2845 return status; 2846 } 2847 2848 void ocfs2_rename_unlock(struct ocfs2_super *osb) 2849 { 2850 struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres; 2851 2852 if (!ocfs2_mount_local(osb)) 2853 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX); 2854 } 2855 2856 int ocfs2_nfs_sync_lock(struct ocfs2_super *osb, int ex) 2857 { 2858 int status; 2859 struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres; 2860 2861 if (ocfs2_is_hard_readonly(osb)) 2862 return -EROFS; 2863 2864 if (ex) 2865 down_write(&osb->nfs_sync_rwlock); 2866 else 2867 down_read(&osb->nfs_sync_rwlock); 2868 2869 if (ocfs2_mount_local(osb)) 2870 return 0; 2871 2872 status = ocfs2_cluster_lock(osb, lockres, ex ? LKM_EXMODE : LKM_PRMODE, 2873 0, 0); 2874 if (status < 0) 2875 mlog(ML_ERROR, "lock on nfs sync lock failed %d\n", status); 2876 2877 return status; 2878 } 2879 2880 void ocfs2_nfs_sync_unlock(struct ocfs2_super *osb, int ex) 2881 { 2882 struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres; 2883 2884 if (!ocfs2_mount_local(osb)) 2885 ocfs2_cluster_unlock(osb, lockres, 2886 ex ? LKM_EXMODE : LKM_PRMODE); 2887 if (ex) 2888 up_write(&osb->nfs_sync_rwlock); 2889 else 2890 up_read(&osb->nfs_sync_rwlock); 2891 } 2892 2893 int ocfs2_trim_fs_lock(struct ocfs2_super *osb, 2894 struct ocfs2_trim_fs_info *info, int trylock) 2895 { 2896 int status; 2897 struct ocfs2_trim_fs_lvb *lvb; 2898 struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres; 2899 2900 if (info) 2901 info->tf_valid = 0; 2902 2903 if (ocfs2_is_hard_readonly(osb)) 2904 return -EROFS; 2905 2906 if (ocfs2_mount_local(osb)) 2907 return 0; 2908 2909 status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, 2910 trylock ? DLM_LKF_NOQUEUE : 0, 0); 2911 if (status < 0) { 2912 if (status != -EAGAIN) 2913 mlog_errno(status); 2914 return status; 2915 } 2916 2917 if (info) { 2918 lvb = ocfs2_dlm_lvb(&lockres->l_lksb); 2919 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) && 2920 lvb->lvb_version == OCFS2_TRIMFS_LVB_VERSION) { 2921 info->tf_valid = 1; 2922 info->tf_success = lvb->lvb_success; 2923 info->tf_nodenum = be32_to_cpu(lvb->lvb_nodenum); 2924 info->tf_start = be64_to_cpu(lvb->lvb_start); 2925 info->tf_len = be64_to_cpu(lvb->lvb_len); 2926 info->tf_minlen = be64_to_cpu(lvb->lvb_minlen); 2927 info->tf_trimlen = be64_to_cpu(lvb->lvb_trimlen); 2928 } 2929 } 2930 2931 return status; 2932 } 2933 2934 void ocfs2_trim_fs_unlock(struct ocfs2_super *osb, 2935 struct ocfs2_trim_fs_info *info) 2936 { 2937 struct ocfs2_trim_fs_lvb *lvb; 2938 struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres; 2939 2940 if (ocfs2_mount_local(osb)) 2941 return; 2942 2943 if (info) { 2944 lvb = ocfs2_dlm_lvb(&lockres->l_lksb); 2945 lvb->lvb_version = OCFS2_TRIMFS_LVB_VERSION; 2946 lvb->lvb_success = info->tf_success; 2947 lvb->lvb_nodenum = cpu_to_be32(info->tf_nodenum); 2948 lvb->lvb_start = cpu_to_be64(info->tf_start); 2949 lvb->lvb_len = cpu_to_be64(info->tf_len); 2950 lvb->lvb_minlen = cpu_to_be64(info->tf_minlen); 2951 lvb->lvb_trimlen = cpu_to_be64(info->tf_trimlen); 2952 } 2953 2954 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX); 2955 } 2956 2957 int ocfs2_dentry_lock(struct dentry *dentry, int ex) 2958 { 2959 int ret; 2960 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 2961 struct ocfs2_dentry_lock *dl = dentry->d_fsdata; 2962 struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb); 2963 2964 BUG_ON(!dl); 2965 2966 if (ocfs2_is_hard_readonly(osb)) { 2967 if (ex) 2968 return -EROFS; 2969 return 0; 2970 } 2971 2972 if (ocfs2_mount_local(osb)) 2973 return 0; 2974 2975 ret = ocfs2_cluster_lock(osb, &dl->dl_lockres, level, 0, 0); 2976 if (ret < 0) 2977 mlog_errno(ret); 2978 2979 return ret; 2980 } 2981 2982 void ocfs2_dentry_unlock(struct dentry *dentry, int ex) 2983 { 2984 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 2985 struct ocfs2_dentry_lock *dl = dentry->d_fsdata; 2986 struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb); 2987 2988 if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb)) 2989 ocfs2_cluster_unlock(osb, &dl->dl_lockres, level); 2990 } 2991 2992 /* Reference counting of the dlm debug structure. We want this because 2993 * open references on the debug inodes can live on after a mount, so 2994 * we can't rely on the ocfs2_super to always exist. */ 2995 static void ocfs2_dlm_debug_free(struct kref *kref) 2996 { 2997 struct ocfs2_dlm_debug *dlm_debug; 2998 2999 dlm_debug = container_of(kref, struct ocfs2_dlm_debug, d_refcnt); 3000 3001 kfree(dlm_debug); 3002 } 3003 3004 void ocfs2_put_dlm_debug(struct ocfs2_dlm_debug *dlm_debug) 3005 { 3006 if (dlm_debug) 3007 kref_put(&dlm_debug->d_refcnt, ocfs2_dlm_debug_free); 3008 } 3009 3010 static void ocfs2_get_dlm_debug(struct ocfs2_dlm_debug *debug) 3011 { 3012 kref_get(&debug->d_refcnt); 3013 } 3014 3015 struct ocfs2_dlm_debug *ocfs2_new_dlm_debug(void) 3016 { 3017 struct ocfs2_dlm_debug *dlm_debug; 3018 3019 dlm_debug = kmalloc(sizeof(struct ocfs2_dlm_debug), GFP_KERNEL); 3020 if (!dlm_debug) { 3021 mlog_errno(-ENOMEM); 3022 goto out; 3023 } 3024 3025 kref_init(&dlm_debug->d_refcnt); 3026 INIT_LIST_HEAD(&dlm_debug->d_lockres_tracking); 3027 dlm_debug->d_filter_secs = 0; 3028 out: 3029 return dlm_debug; 3030 } 3031 3032 /* Access to this is arbitrated for us via seq_file->sem. */ 3033 struct ocfs2_dlm_seq_priv { 3034 struct ocfs2_dlm_debug *p_dlm_debug; 3035 struct ocfs2_lock_res p_iter_res; 3036 struct ocfs2_lock_res p_tmp_res; 3037 }; 3038 3039 static struct ocfs2_lock_res *ocfs2_dlm_next_res(struct ocfs2_lock_res *start, 3040 struct ocfs2_dlm_seq_priv *priv) 3041 { 3042 struct ocfs2_lock_res *iter, *ret = NULL; 3043 struct ocfs2_dlm_debug *dlm_debug = priv->p_dlm_debug; 3044 3045 assert_spin_locked(&ocfs2_dlm_tracking_lock); 3046 3047 list_for_each_entry(iter, &start->l_debug_list, l_debug_list) { 3048 /* discover the head of the list */ 3049 if (&iter->l_debug_list == &dlm_debug->d_lockres_tracking) { 3050 mlog(0, "End of list found, %p\n", ret); 3051 break; 3052 } 3053 3054 /* We track our "dummy" iteration lockres' by a NULL 3055 * l_ops field. */ 3056 if (iter->l_ops != NULL) { 3057 ret = iter; 3058 break; 3059 } 3060 } 3061 3062 return ret; 3063 } 3064 3065 static void *ocfs2_dlm_seq_start(struct seq_file *m, loff_t *pos) 3066 { 3067 struct ocfs2_dlm_seq_priv *priv = m->private; 3068 struct ocfs2_lock_res *iter; 3069 3070 spin_lock(&ocfs2_dlm_tracking_lock); 3071 iter = ocfs2_dlm_next_res(&priv->p_iter_res, priv); 3072 if (iter) { 3073 /* Since lockres' have the lifetime of their container 3074 * (which can be inodes, ocfs2_supers, etc) we want to 3075 * copy this out to a temporary lockres while still 3076 * under the spinlock. Obviously after this we can't 3077 * trust any pointers on the copy returned, but that's 3078 * ok as the information we want isn't typically held 3079 * in them. */ 3080 priv->p_tmp_res = *iter; 3081 iter = &priv->p_tmp_res; 3082 } 3083 spin_unlock(&ocfs2_dlm_tracking_lock); 3084 3085 return iter; 3086 } 3087 3088 static void ocfs2_dlm_seq_stop(struct seq_file *m, void *v) 3089 { 3090 } 3091 3092 static void *ocfs2_dlm_seq_next(struct seq_file *m, void *v, loff_t *pos) 3093 { 3094 struct ocfs2_dlm_seq_priv *priv = m->private; 3095 struct ocfs2_lock_res *iter = v; 3096 struct ocfs2_lock_res *dummy = &priv->p_iter_res; 3097 3098 spin_lock(&ocfs2_dlm_tracking_lock); 3099 iter = ocfs2_dlm_next_res(iter, priv); 3100 list_del_init(&dummy->l_debug_list); 3101 if (iter) { 3102 list_add(&dummy->l_debug_list, &iter->l_debug_list); 3103 priv->p_tmp_res = *iter; 3104 iter = &priv->p_tmp_res; 3105 } 3106 spin_unlock(&ocfs2_dlm_tracking_lock); 3107 3108 return iter; 3109 } 3110 3111 /* 3112 * Version is used by debugfs.ocfs2 to determine the format being used 3113 * 3114 * New in version 2 3115 * - Lock stats printed 3116 * New in version 3 3117 * - Max time in lock stats is in usecs (instead of nsecs) 3118 * New in version 4 3119 * - Add last pr/ex unlock times and first lock wait time in usecs 3120 */ 3121 #define OCFS2_DLM_DEBUG_STR_VERSION 4 3122 static int ocfs2_dlm_seq_show(struct seq_file *m, void *v) 3123 { 3124 int i; 3125 char *lvb; 3126 struct ocfs2_lock_res *lockres = v; 3127 #ifdef CONFIG_OCFS2_FS_STATS 3128 u64 now, last; 3129 struct ocfs2_dlm_debug *dlm_debug = 3130 ((struct ocfs2_dlm_seq_priv *)m->private)->p_dlm_debug; 3131 #endif 3132 3133 if (!lockres) 3134 return -EINVAL; 3135 3136 #ifdef CONFIG_OCFS2_FS_STATS 3137 if (!lockres->l_lock_wait && dlm_debug->d_filter_secs) { 3138 now = ktime_to_us(ktime_get_real()); 3139 if (lockres->l_lock_prmode.ls_last > 3140 lockres->l_lock_exmode.ls_last) 3141 last = lockres->l_lock_prmode.ls_last; 3142 else 3143 last = lockres->l_lock_exmode.ls_last; 3144 /* 3145 * Use d_filter_secs field to filter lock resources dump, 3146 * the default d_filter_secs(0) value filters nothing, 3147 * otherwise, only dump the last N seconds active lock 3148 * resources. 3149 */ 3150 if (div_u64(now - last, 1000000) > dlm_debug->d_filter_secs) 3151 return 0; 3152 } 3153 #endif 3154 3155 seq_printf(m, "0x%x\t", OCFS2_DLM_DEBUG_STR_VERSION); 3156 3157 if (lockres->l_type == OCFS2_LOCK_TYPE_DENTRY) 3158 seq_printf(m, "%.*s%08x\t", OCFS2_DENTRY_LOCK_INO_START - 1, 3159 lockres->l_name, 3160 (unsigned int)ocfs2_get_dentry_lock_ino(lockres)); 3161 else 3162 seq_printf(m, "%.*s\t", OCFS2_LOCK_ID_MAX_LEN, lockres->l_name); 3163 3164 seq_printf(m, "%d\t" 3165 "0x%lx\t" 3166 "0x%x\t" 3167 "0x%x\t" 3168 "%u\t" 3169 "%u\t" 3170 "%d\t" 3171 "%d\t", 3172 lockres->l_level, 3173 lockres->l_flags, 3174 lockres->l_action, 3175 lockres->l_unlock_action, 3176 lockres->l_ro_holders, 3177 lockres->l_ex_holders, 3178 lockres->l_requested, 3179 lockres->l_blocking); 3180 3181 /* Dump the raw LVB */ 3182 lvb = ocfs2_dlm_lvb(&lockres->l_lksb); 3183 for(i = 0; i < DLM_LVB_LEN; i++) 3184 seq_printf(m, "0x%x\t", lvb[i]); 3185 3186 #ifdef CONFIG_OCFS2_FS_STATS 3187 # define lock_num_prmode(_l) ((_l)->l_lock_prmode.ls_gets) 3188 # define lock_num_exmode(_l) ((_l)->l_lock_exmode.ls_gets) 3189 # define lock_num_prmode_failed(_l) ((_l)->l_lock_prmode.ls_fail) 3190 # define lock_num_exmode_failed(_l) ((_l)->l_lock_exmode.ls_fail) 3191 # define lock_total_prmode(_l) ((_l)->l_lock_prmode.ls_total) 3192 # define lock_total_exmode(_l) ((_l)->l_lock_exmode.ls_total) 3193 # define lock_max_prmode(_l) ((_l)->l_lock_prmode.ls_max) 3194 # define lock_max_exmode(_l) ((_l)->l_lock_exmode.ls_max) 3195 # define lock_refresh(_l) ((_l)->l_lock_refresh) 3196 # define lock_last_prmode(_l) ((_l)->l_lock_prmode.ls_last) 3197 # define lock_last_exmode(_l) ((_l)->l_lock_exmode.ls_last) 3198 # define lock_wait(_l) ((_l)->l_lock_wait) 3199 #else 3200 # define lock_num_prmode(_l) (0) 3201 # define lock_num_exmode(_l) (0) 3202 # define lock_num_prmode_failed(_l) (0) 3203 # define lock_num_exmode_failed(_l) (0) 3204 # define lock_total_prmode(_l) (0ULL) 3205 # define lock_total_exmode(_l) (0ULL) 3206 # define lock_max_prmode(_l) (0) 3207 # define lock_max_exmode(_l) (0) 3208 # define lock_refresh(_l) (0) 3209 # define lock_last_prmode(_l) (0ULL) 3210 # define lock_last_exmode(_l) (0ULL) 3211 # define lock_wait(_l) (0ULL) 3212 #endif 3213 /* The following seq_print was added in version 2 of this output */ 3214 seq_printf(m, "%u\t" 3215 "%u\t" 3216 "%u\t" 3217 "%u\t" 3218 "%llu\t" 3219 "%llu\t" 3220 "%u\t" 3221 "%u\t" 3222 "%u\t" 3223 "%llu\t" 3224 "%llu\t" 3225 "%llu\t", 3226 lock_num_prmode(lockres), 3227 lock_num_exmode(lockres), 3228 lock_num_prmode_failed(lockres), 3229 lock_num_exmode_failed(lockres), 3230 lock_total_prmode(lockres), 3231 lock_total_exmode(lockres), 3232 lock_max_prmode(lockres), 3233 lock_max_exmode(lockres), 3234 lock_refresh(lockres), 3235 lock_last_prmode(lockres), 3236 lock_last_exmode(lockres), 3237 lock_wait(lockres)); 3238 3239 /* End the line */ 3240 seq_printf(m, "\n"); 3241 return 0; 3242 } 3243 3244 static const struct seq_operations ocfs2_dlm_seq_ops = { 3245 .start = ocfs2_dlm_seq_start, 3246 .stop = ocfs2_dlm_seq_stop, 3247 .next = ocfs2_dlm_seq_next, 3248 .show = ocfs2_dlm_seq_show, 3249 }; 3250 3251 static int ocfs2_dlm_debug_release(struct inode *inode, struct file *file) 3252 { 3253 struct seq_file *seq = file->private_data; 3254 struct ocfs2_dlm_seq_priv *priv = seq->private; 3255 struct ocfs2_lock_res *res = &priv->p_iter_res; 3256 3257 ocfs2_remove_lockres_tracking(res); 3258 ocfs2_put_dlm_debug(priv->p_dlm_debug); 3259 return seq_release_private(inode, file); 3260 } 3261 3262 static int ocfs2_dlm_debug_open(struct inode *inode, struct file *file) 3263 { 3264 struct ocfs2_dlm_seq_priv *priv; 3265 struct ocfs2_super *osb; 3266 3267 priv = __seq_open_private(file, &ocfs2_dlm_seq_ops, sizeof(*priv)); 3268 if (!priv) { 3269 mlog_errno(-ENOMEM); 3270 return -ENOMEM; 3271 } 3272 3273 osb = inode->i_private; 3274 ocfs2_get_dlm_debug(osb->osb_dlm_debug); 3275 priv->p_dlm_debug = osb->osb_dlm_debug; 3276 INIT_LIST_HEAD(&priv->p_iter_res.l_debug_list); 3277 3278 ocfs2_add_lockres_tracking(&priv->p_iter_res, 3279 priv->p_dlm_debug); 3280 3281 return 0; 3282 } 3283 3284 static const struct file_operations ocfs2_dlm_debug_fops = { 3285 .open = ocfs2_dlm_debug_open, 3286 .release = ocfs2_dlm_debug_release, 3287 .read = seq_read, 3288 .llseek = seq_lseek, 3289 }; 3290 3291 static void ocfs2_dlm_init_debug(struct ocfs2_super *osb) 3292 { 3293 struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug; 3294 3295 debugfs_create_file("locking_state", S_IFREG|S_IRUSR, 3296 osb->osb_debug_root, osb, &ocfs2_dlm_debug_fops); 3297 3298 debugfs_create_u32("locking_filter", 0600, osb->osb_debug_root, 3299 &dlm_debug->d_filter_secs); 3300 ocfs2_get_dlm_debug(dlm_debug); 3301 } 3302 3303 static void ocfs2_dlm_shutdown_debug(struct ocfs2_super *osb) 3304 { 3305 struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug; 3306 3307 if (dlm_debug) 3308 ocfs2_put_dlm_debug(dlm_debug); 3309 } 3310 3311 int ocfs2_dlm_init(struct ocfs2_super *osb) 3312 { 3313 int status = 0; 3314 struct ocfs2_cluster_connection *conn = NULL; 3315 3316 if (ocfs2_mount_local(osb)) { 3317 osb->node_num = 0; 3318 goto local; 3319 } 3320 3321 ocfs2_dlm_init_debug(osb); 3322 3323 /* launch downconvert thread */ 3324 osb->dc_task = kthread_run(ocfs2_downconvert_thread, osb, "ocfs2dc-%s", 3325 osb->uuid_str); 3326 if (IS_ERR(osb->dc_task)) { 3327 status = PTR_ERR(osb->dc_task); 3328 osb->dc_task = NULL; 3329 mlog_errno(status); 3330 goto bail; 3331 } 3332 3333 /* for now, uuid == domain */ 3334 status = ocfs2_cluster_connect(osb->osb_cluster_stack, 3335 osb->osb_cluster_name, 3336 strlen(osb->osb_cluster_name), 3337 osb->uuid_str, 3338 strlen(osb->uuid_str), 3339 &lproto, ocfs2_do_node_down, osb, 3340 &conn); 3341 if (status) { 3342 mlog_errno(status); 3343 goto bail; 3344 } 3345 3346 status = ocfs2_cluster_this_node(conn, &osb->node_num); 3347 if (status < 0) { 3348 mlog_errno(status); 3349 mlog(ML_ERROR, 3350 "could not find this host's node number\n"); 3351 ocfs2_cluster_disconnect(conn, 0); 3352 goto bail; 3353 } 3354 3355 local: 3356 ocfs2_super_lock_res_init(&osb->osb_super_lockres, osb); 3357 ocfs2_rename_lock_res_init(&osb->osb_rename_lockres, osb); 3358 ocfs2_nfs_sync_lock_init(osb); 3359 ocfs2_orphan_scan_lock_res_init(&osb->osb_orphan_scan.os_lockres, osb); 3360 3361 osb->cconn = conn; 3362 bail: 3363 if (status < 0) { 3364 ocfs2_dlm_shutdown_debug(osb); 3365 if (osb->dc_task) 3366 kthread_stop(osb->dc_task); 3367 } 3368 3369 return status; 3370 } 3371 3372 void ocfs2_dlm_shutdown(struct ocfs2_super *osb, 3373 int hangup_pending) 3374 { 3375 ocfs2_drop_osb_locks(osb); 3376 3377 /* 3378 * Now that we have dropped all locks and ocfs2_dismount_volume() 3379 * has disabled recovery, the DLM won't be talking to us. It's 3380 * safe to tear things down before disconnecting the cluster. 3381 */ 3382 3383 if (osb->dc_task) { 3384 kthread_stop(osb->dc_task); 3385 osb->dc_task = NULL; 3386 } 3387 3388 ocfs2_lock_res_free(&osb->osb_super_lockres); 3389 ocfs2_lock_res_free(&osb->osb_rename_lockres); 3390 ocfs2_lock_res_free(&osb->osb_nfs_sync_lockres); 3391 ocfs2_lock_res_free(&osb->osb_orphan_scan.os_lockres); 3392 3393 ocfs2_cluster_disconnect(osb->cconn, hangup_pending); 3394 osb->cconn = NULL; 3395 3396 ocfs2_dlm_shutdown_debug(osb); 3397 } 3398 3399 static int ocfs2_drop_lock(struct ocfs2_super *osb, 3400 struct ocfs2_lock_res *lockres) 3401 { 3402 int ret; 3403 unsigned long flags; 3404 u32 lkm_flags = 0; 3405 3406 /* We didn't get anywhere near actually using this lockres. */ 3407 if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED)) 3408 goto out; 3409 3410 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) 3411 lkm_flags |= DLM_LKF_VALBLK; 3412 3413 spin_lock_irqsave(&lockres->l_lock, flags); 3414 3415 mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_FREEING), 3416 "lockres %s, flags 0x%lx\n", 3417 lockres->l_name, lockres->l_flags); 3418 3419 while (lockres->l_flags & OCFS2_LOCK_BUSY) { 3420 mlog(0, "waiting on busy lock \"%s\": flags = %lx, action = " 3421 "%u, unlock_action = %u\n", 3422 lockres->l_name, lockres->l_flags, lockres->l_action, 3423 lockres->l_unlock_action); 3424 3425 spin_unlock_irqrestore(&lockres->l_lock, flags); 3426 3427 /* XXX: Today we just wait on any busy 3428 * locks... Perhaps we need to cancel converts in the 3429 * future? */ 3430 ocfs2_wait_on_busy_lock(lockres); 3431 3432 spin_lock_irqsave(&lockres->l_lock, flags); 3433 } 3434 3435 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) { 3436 if (lockres->l_flags & OCFS2_LOCK_ATTACHED && 3437 lockres->l_level == DLM_LOCK_EX && 3438 !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) 3439 lockres->l_ops->set_lvb(lockres); 3440 } 3441 3442 if (lockres->l_flags & OCFS2_LOCK_BUSY) 3443 mlog(ML_ERROR, "destroying busy lock: \"%s\"\n", 3444 lockres->l_name); 3445 if (lockres->l_flags & OCFS2_LOCK_BLOCKED) 3446 mlog(0, "destroying blocked lock: \"%s\"\n", lockres->l_name); 3447 3448 if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) { 3449 spin_unlock_irqrestore(&lockres->l_lock, flags); 3450 goto out; 3451 } 3452 3453 lockres_clear_flags(lockres, OCFS2_LOCK_ATTACHED); 3454 3455 /* make sure we never get here while waiting for an ast to 3456 * fire. */ 3457 BUG_ON(lockres->l_action != OCFS2_AST_INVALID); 3458 3459 /* is this necessary? */ 3460 lockres_or_flags(lockres, OCFS2_LOCK_BUSY); 3461 lockres->l_unlock_action = OCFS2_UNLOCK_DROP_LOCK; 3462 spin_unlock_irqrestore(&lockres->l_lock, flags); 3463 3464 mlog(0, "lock %s\n", lockres->l_name); 3465 3466 ret = ocfs2_dlm_unlock(osb->cconn, &lockres->l_lksb, lkm_flags); 3467 if (ret) { 3468 ocfs2_log_dlm_error("ocfs2_dlm_unlock", ret, lockres); 3469 mlog(ML_ERROR, "lockres flags: %lu\n", lockres->l_flags); 3470 ocfs2_dlm_dump_lksb(&lockres->l_lksb); 3471 BUG(); 3472 } 3473 mlog(0, "lock %s, successful return from ocfs2_dlm_unlock\n", 3474 lockres->l_name); 3475 3476 ocfs2_wait_on_busy_lock(lockres); 3477 out: 3478 return 0; 3479 } 3480 3481 static void ocfs2_process_blocked_lock(struct ocfs2_super *osb, 3482 struct ocfs2_lock_res *lockres); 3483 3484 /* Mark the lockres as being dropped. It will no longer be 3485 * queued if blocking, but we still may have to wait on it 3486 * being dequeued from the downconvert thread before we can consider 3487 * it safe to drop. 3488 * 3489 * You can *not* attempt to call cluster_lock on this lockres anymore. */ 3490 void ocfs2_mark_lockres_freeing(struct ocfs2_super *osb, 3491 struct ocfs2_lock_res *lockres) 3492 { 3493 int status; 3494 struct ocfs2_mask_waiter mw; 3495 unsigned long flags, flags2; 3496 3497 ocfs2_init_mask_waiter(&mw); 3498 3499 spin_lock_irqsave(&lockres->l_lock, flags); 3500 lockres->l_flags |= OCFS2_LOCK_FREEING; 3501 if (lockres->l_flags & OCFS2_LOCK_QUEUED && current == osb->dc_task) { 3502 /* 3503 * We know the downconvert is queued but not in progress 3504 * because we are the downconvert thread and processing 3505 * different lock. So we can just remove the lock from the 3506 * queue. This is not only an optimization but also a way 3507 * to avoid the following deadlock: 3508 * ocfs2_dentry_post_unlock() 3509 * ocfs2_dentry_lock_put() 3510 * ocfs2_drop_dentry_lock() 3511 * iput() 3512 * ocfs2_evict_inode() 3513 * ocfs2_clear_inode() 3514 * ocfs2_mark_lockres_freeing() 3515 * ... blocks waiting for OCFS2_LOCK_QUEUED 3516 * since we are the downconvert thread which 3517 * should clear the flag. 3518 */ 3519 spin_unlock_irqrestore(&lockres->l_lock, flags); 3520 spin_lock_irqsave(&osb->dc_task_lock, flags2); 3521 list_del_init(&lockres->l_blocked_list); 3522 osb->blocked_lock_count--; 3523 spin_unlock_irqrestore(&osb->dc_task_lock, flags2); 3524 /* 3525 * Warn if we recurse into another post_unlock call. Strictly 3526 * speaking it isn't a problem but we need to be careful if 3527 * that happens (stack overflow, deadlocks, ...) so warn if 3528 * ocfs2 grows a path for which this can happen. 3529 */ 3530 WARN_ON_ONCE(lockres->l_ops->post_unlock); 3531 /* Since the lock is freeing we don't do much in the fn below */ 3532 ocfs2_process_blocked_lock(osb, lockres); 3533 return; 3534 } 3535 while (lockres->l_flags & OCFS2_LOCK_QUEUED) { 3536 lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_QUEUED, 0); 3537 spin_unlock_irqrestore(&lockres->l_lock, flags); 3538 3539 mlog(0, "Waiting on lockres %s\n", lockres->l_name); 3540 3541 status = ocfs2_wait_for_mask(&mw); 3542 if (status) 3543 mlog_errno(status); 3544 3545 spin_lock_irqsave(&lockres->l_lock, flags); 3546 } 3547 spin_unlock_irqrestore(&lockres->l_lock, flags); 3548 } 3549 3550 void ocfs2_simple_drop_lockres(struct ocfs2_super *osb, 3551 struct ocfs2_lock_res *lockres) 3552 { 3553 int ret; 3554 3555 ocfs2_mark_lockres_freeing(osb, lockres); 3556 ret = ocfs2_drop_lock(osb, lockres); 3557 if (ret) 3558 mlog_errno(ret); 3559 } 3560 3561 static void ocfs2_drop_osb_locks(struct ocfs2_super *osb) 3562 { 3563 ocfs2_simple_drop_lockres(osb, &osb->osb_super_lockres); 3564 ocfs2_simple_drop_lockres(osb, &osb->osb_rename_lockres); 3565 ocfs2_simple_drop_lockres(osb, &osb->osb_nfs_sync_lockres); 3566 ocfs2_simple_drop_lockres(osb, &osb->osb_orphan_scan.os_lockres); 3567 } 3568 3569 int ocfs2_drop_inode_locks(struct inode *inode) 3570 { 3571 int status, err; 3572 3573 /* No need to call ocfs2_mark_lockres_freeing here - 3574 * ocfs2_clear_inode has done it for us. */ 3575 3576 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb), 3577 &OCFS2_I(inode)->ip_open_lockres); 3578 if (err < 0) 3579 mlog_errno(err); 3580 3581 status = err; 3582 3583 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb), 3584 &OCFS2_I(inode)->ip_inode_lockres); 3585 if (err < 0) 3586 mlog_errno(err); 3587 if (err < 0 && !status) 3588 status = err; 3589 3590 err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb), 3591 &OCFS2_I(inode)->ip_rw_lockres); 3592 if (err < 0) 3593 mlog_errno(err); 3594 if (err < 0 && !status) 3595 status = err; 3596 3597 return status; 3598 } 3599 3600 static unsigned int ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres, 3601 int new_level) 3602 { 3603 assert_spin_locked(&lockres->l_lock); 3604 3605 BUG_ON(lockres->l_blocking <= DLM_LOCK_NL); 3606 3607 if (lockres->l_level <= new_level) { 3608 mlog(ML_ERROR, "lockres %s, lvl %d <= %d, blcklst %d, mask %d, " 3609 "type %d, flags 0x%lx, hold %d %d, act %d %d, req %d, " 3610 "block %d, pgen %d\n", lockres->l_name, lockres->l_level, 3611 new_level, list_empty(&lockres->l_blocked_list), 3612 list_empty(&lockres->l_mask_waiters), lockres->l_type, 3613 lockres->l_flags, lockres->l_ro_holders, 3614 lockres->l_ex_holders, lockres->l_action, 3615 lockres->l_unlock_action, lockres->l_requested, 3616 lockres->l_blocking, lockres->l_pending_gen); 3617 BUG(); 3618 } 3619 3620 mlog(ML_BASTS, "lockres %s, level %d => %d, blocking %d\n", 3621 lockres->l_name, lockres->l_level, new_level, lockres->l_blocking); 3622 3623 lockres->l_action = OCFS2_AST_DOWNCONVERT; 3624 lockres->l_requested = new_level; 3625 lockres_or_flags(lockres, OCFS2_LOCK_BUSY); 3626 return lockres_set_pending(lockres); 3627 } 3628 3629 static int ocfs2_downconvert_lock(struct ocfs2_super *osb, 3630 struct ocfs2_lock_res *lockres, 3631 int new_level, 3632 int lvb, 3633 unsigned int generation) 3634 { 3635 int ret; 3636 u32 dlm_flags = DLM_LKF_CONVERT; 3637 3638 mlog(ML_BASTS, "lockres %s, level %d => %d\n", lockres->l_name, 3639 lockres->l_level, new_level); 3640 3641 /* 3642 * On DLM_LKF_VALBLK, fsdlm behaves differently with o2cb. It always 3643 * expects DLM_LKF_VALBLK being set if the LKB has LVB, so that 3644 * we can recover correctly from node failure. Otherwise, we may get 3645 * invalid LVB in LKB, but without DLM_SBF_VALNOTVALID being set. 3646 */ 3647 if (ocfs2_userspace_stack(osb) && 3648 lockres->l_ops->flags & LOCK_TYPE_USES_LVB) 3649 lvb = 1; 3650 3651 if (lvb) 3652 dlm_flags |= DLM_LKF_VALBLK; 3653 3654 ret = ocfs2_dlm_lock(osb->cconn, 3655 new_level, 3656 &lockres->l_lksb, 3657 dlm_flags, 3658 lockres->l_name, 3659 OCFS2_LOCK_ID_MAX_LEN - 1); 3660 lockres_clear_pending(lockres, generation, osb); 3661 if (ret) { 3662 ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres); 3663 ocfs2_recover_from_dlm_error(lockres, 1); 3664 goto bail; 3665 } 3666 3667 ret = 0; 3668 bail: 3669 return ret; 3670 } 3671 3672 /* returns 1 when the caller should unlock and call ocfs2_dlm_unlock */ 3673 static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb, 3674 struct ocfs2_lock_res *lockres) 3675 { 3676 assert_spin_locked(&lockres->l_lock); 3677 3678 if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) { 3679 /* If we're already trying to cancel a lock conversion 3680 * then just drop the spinlock and allow the caller to 3681 * requeue this lock. */ 3682 mlog(ML_BASTS, "lockres %s, skip convert\n", lockres->l_name); 3683 return 0; 3684 } 3685 3686 /* were we in a convert when we got the bast fire? */ 3687 BUG_ON(lockres->l_action != OCFS2_AST_CONVERT && 3688 lockres->l_action != OCFS2_AST_DOWNCONVERT); 3689 /* set things up for the unlockast to know to just 3690 * clear out the ast_action and unset busy, etc. */ 3691 lockres->l_unlock_action = OCFS2_UNLOCK_CANCEL_CONVERT; 3692 3693 mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_BUSY), 3694 "lock %s, invalid flags: 0x%lx\n", 3695 lockres->l_name, lockres->l_flags); 3696 3697 mlog(ML_BASTS, "lockres %s\n", lockres->l_name); 3698 3699 return 1; 3700 } 3701 3702 static int ocfs2_cancel_convert(struct ocfs2_super *osb, 3703 struct ocfs2_lock_res *lockres) 3704 { 3705 int ret; 3706 3707 ret = ocfs2_dlm_unlock(osb->cconn, &lockres->l_lksb, 3708 DLM_LKF_CANCEL); 3709 if (ret) { 3710 ocfs2_log_dlm_error("ocfs2_dlm_unlock", ret, lockres); 3711 ocfs2_recover_from_dlm_error(lockres, 0); 3712 } 3713 3714 mlog(ML_BASTS, "lockres %s\n", lockres->l_name); 3715 3716 return ret; 3717 } 3718 3719 static int ocfs2_unblock_lock(struct ocfs2_super *osb, 3720 struct ocfs2_lock_res *lockres, 3721 struct ocfs2_unblock_ctl *ctl) 3722 { 3723 unsigned long flags; 3724 int blocking; 3725 int new_level; 3726 int level; 3727 int ret = 0; 3728 int set_lvb = 0; 3729 unsigned int gen; 3730 3731 spin_lock_irqsave(&lockres->l_lock, flags); 3732 3733 recheck: 3734 /* 3735 * Is it still blocking? If not, we have no more work to do. 3736 */ 3737 if (!(lockres->l_flags & OCFS2_LOCK_BLOCKED)) { 3738 BUG_ON(lockres->l_blocking != DLM_LOCK_NL); 3739 spin_unlock_irqrestore(&lockres->l_lock, flags); 3740 ret = 0; 3741 goto leave; 3742 } 3743 3744 if (lockres->l_flags & OCFS2_LOCK_BUSY) { 3745 /* XXX 3746 * This is a *big* race. The OCFS2_LOCK_PENDING flag 3747 * exists entirely for one reason - another thread has set 3748 * OCFS2_LOCK_BUSY, but has *NOT* yet called dlm_lock(). 3749 * 3750 * If we do ocfs2_cancel_convert() before the other thread 3751 * calls dlm_lock(), our cancel will do nothing. We will 3752 * get no ast, and we will have no way of knowing the 3753 * cancel failed. Meanwhile, the other thread will call 3754 * into dlm_lock() and wait...forever. 3755 * 3756 * Why forever? Because another node has asked for the 3757 * lock first; that's why we're here in unblock_lock(). 3758 * 3759 * The solution is OCFS2_LOCK_PENDING. When PENDING is 3760 * set, we just requeue the unblock. Only when the other 3761 * thread has called dlm_lock() and cleared PENDING will 3762 * we then cancel their request. 3763 * 3764 * All callers of dlm_lock() must set OCFS2_DLM_PENDING 3765 * at the same time they set OCFS2_DLM_BUSY. They must 3766 * clear OCFS2_DLM_PENDING after dlm_lock() returns. 3767 */ 3768 if (lockres->l_flags & OCFS2_LOCK_PENDING) { 3769 mlog(ML_BASTS, "lockres %s, ReQ: Pending\n", 3770 lockres->l_name); 3771 goto leave_requeue; 3772 } 3773 3774 ctl->requeue = 1; 3775 ret = ocfs2_prepare_cancel_convert(osb, lockres); 3776 spin_unlock_irqrestore(&lockres->l_lock, flags); 3777 if (ret) { 3778 ret = ocfs2_cancel_convert(osb, lockres); 3779 if (ret < 0) 3780 mlog_errno(ret); 3781 } 3782 goto leave; 3783 } 3784 3785 /* 3786 * This prevents livelocks. OCFS2_LOCK_UPCONVERT_FINISHING flag is 3787 * set when the ast is received for an upconvert just before the 3788 * OCFS2_LOCK_BUSY flag is cleared. Now if the fs received a bast 3789 * on the heels of the ast, we want to delay the downconvert just 3790 * enough to allow the up requestor to do its task. Because this 3791 * lock is in the blocked queue, the lock will be downconverted 3792 * as soon as the requestor is done with the lock. 3793 */ 3794 if (lockres->l_flags & OCFS2_LOCK_UPCONVERT_FINISHING) 3795 goto leave_requeue; 3796 3797 /* 3798 * How can we block and yet be at NL? We were trying to upconvert 3799 * from NL and got canceled. The code comes back here, and now 3800 * we notice and clear BLOCKING. 3801 */ 3802 if (lockres->l_level == DLM_LOCK_NL) { 3803 BUG_ON(lockres->l_ex_holders || lockres->l_ro_holders); 3804 mlog(ML_BASTS, "lockres %s, Aborting dc\n", lockres->l_name); 3805 lockres->l_blocking = DLM_LOCK_NL; 3806 lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED); 3807 spin_unlock_irqrestore(&lockres->l_lock, flags); 3808 goto leave; 3809 } 3810 3811 /* if we're blocking an exclusive and we have *any* holders, 3812 * then requeue. */ 3813 if ((lockres->l_blocking == DLM_LOCK_EX) 3814 && (lockres->l_ex_holders || lockres->l_ro_holders)) { 3815 mlog(ML_BASTS, "lockres %s, ReQ: EX/PR Holders %u,%u\n", 3816 lockres->l_name, lockres->l_ex_holders, 3817 lockres->l_ro_holders); 3818 goto leave_requeue; 3819 } 3820 3821 /* If it's a PR we're blocking, then only 3822 * requeue if we've got any EX holders */ 3823 if (lockres->l_blocking == DLM_LOCK_PR && 3824 lockres->l_ex_holders) { 3825 mlog(ML_BASTS, "lockres %s, ReQ: EX Holders %u\n", 3826 lockres->l_name, lockres->l_ex_holders); 3827 goto leave_requeue; 3828 } 3829 3830 /* 3831 * Can we get a lock in this state if the holder counts are 3832 * zero? The meta data unblock code used to check this. 3833 */ 3834 if ((lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH) 3835 && (lockres->l_flags & OCFS2_LOCK_REFRESHING)) { 3836 mlog(ML_BASTS, "lockres %s, ReQ: Lock Refreshing\n", 3837 lockres->l_name); 3838 goto leave_requeue; 3839 } 3840 3841 new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking); 3842 3843 if (lockres->l_ops->check_downconvert 3844 && !lockres->l_ops->check_downconvert(lockres, new_level)) { 3845 mlog(ML_BASTS, "lockres %s, ReQ: Checkpointing\n", 3846 lockres->l_name); 3847 goto leave_requeue; 3848 } 3849 3850 /* If we get here, then we know that there are no more 3851 * incompatible holders (and anyone asking for an incompatible 3852 * lock is blocked). We can now downconvert the lock */ 3853 if (!lockres->l_ops->downconvert_worker) 3854 goto downconvert; 3855 3856 /* Some lockres types want to do a bit of work before 3857 * downconverting a lock. Allow that here. The worker function 3858 * may sleep, so we save off a copy of what we're blocking as 3859 * it may change while we're not holding the spin lock. */ 3860 blocking = lockres->l_blocking; 3861 level = lockres->l_level; 3862 spin_unlock_irqrestore(&lockres->l_lock, flags); 3863 3864 ctl->unblock_action = lockres->l_ops->downconvert_worker(lockres, blocking); 3865 3866 if (ctl->unblock_action == UNBLOCK_STOP_POST) { 3867 mlog(ML_BASTS, "lockres %s, UNBLOCK_STOP_POST\n", 3868 lockres->l_name); 3869 goto leave; 3870 } 3871 3872 spin_lock_irqsave(&lockres->l_lock, flags); 3873 if ((blocking != lockres->l_blocking) || (level != lockres->l_level)) { 3874 /* If this changed underneath us, then we can't drop 3875 * it just yet. */ 3876 mlog(ML_BASTS, "lockres %s, block=%d:%d, level=%d:%d, " 3877 "Recheck\n", lockres->l_name, blocking, 3878 lockres->l_blocking, level, lockres->l_level); 3879 goto recheck; 3880 } 3881 3882 downconvert: 3883 ctl->requeue = 0; 3884 3885 if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) { 3886 if (lockres->l_level == DLM_LOCK_EX) 3887 set_lvb = 1; 3888 3889 /* 3890 * We only set the lvb if the lock has been fully 3891 * refreshed - otherwise we risk setting stale 3892 * data. Otherwise, there's no need to actually clear 3893 * out the lvb here as it's value is still valid. 3894 */ 3895 if (set_lvb && !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) 3896 lockres->l_ops->set_lvb(lockres); 3897 } 3898 3899 gen = ocfs2_prepare_downconvert(lockres, new_level); 3900 spin_unlock_irqrestore(&lockres->l_lock, flags); 3901 ret = ocfs2_downconvert_lock(osb, lockres, new_level, set_lvb, 3902 gen); 3903 3904 leave: 3905 if (ret) 3906 mlog_errno(ret); 3907 return ret; 3908 3909 leave_requeue: 3910 spin_unlock_irqrestore(&lockres->l_lock, flags); 3911 ctl->requeue = 1; 3912 3913 return 0; 3914 } 3915 3916 static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres, 3917 int blocking) 3918 { 3919 struct inode *inode; 3920 struct address_space *mapping; 3921 struct ocfs2_inode_info *oi; 3922 3923 inode = ocfs2_lock_res_inode(lockres); 3924 mapping = inode->i_mapping; 3925 3926 if (S_ISDIR(inode->i_mode)) { 3927 oi = OCFS2_I(inode); 3928 oi->ip_dir_lock_gen++; 3929 mlog(0, "generation: %u\n", oi->ip_dir_lock_gen); 3930 goto out; 3931 } 3932 3933 if (!S_ISREG(inode->i_mode)) 3934 goto out; 3935 3936 /* 3937 * We need this before the filemap_fdatawrite() so that it can 3938 * transfer the dirty bit from the PTE to the 3939 * page. Unfortunately this means that even for EX->PR 3940 * downconverts, we'll lose our mappings and have to build 3941 * them up again. 3942 */ 3943 unmap_mapping_range(mapping, 0, 0, 0); 3944 3945 if (filemap_fdatawrite(mapping)) { 3946 mlog(ML_ERROR, "Could not sync inode %llu for downconvert!", 3947 (unsigned long long)OCFS2_I(inode)->ip_blkno); 3948 } 3949 sync_mapping_buffers(mapping); 3950 if (blocking == DLM_LOCK_EX) { 3951 truncate_inode_pages(mapping, 0); 3952 } else { 3953 /* We only need to wait on the I/O if we're not also 3954 * truncating pages because truncate_inode_pages waits 3955 * for us above. We don't truncate pages if we're 3956 * blocking anything < EXMODE because we want to keep 3957 * them around in that case. */ 3958 filemap_fdatawait(mapping); 3959 } 3960 3961 forget_all_cached_acls(inode); 3962 3963 out: 3964 return UNBLOCK_CONTINUE; 3965 } 3966 3967 static int ocfs2_ci_checkpointed(struct ocfs2_caching_info *ci, 3968 struct ocfs2_lock_res *lockres, 3969 int new_level) 3970 { 3971 int checkpointed = ocfs2_ci_fully_checkpointed(ci); 3972 3973 BUG_ON(new_level != DLM_LOCK_NL && new_level != DLM_LOCK_PR); 3974 BUG_ON(lockres->l_level != DLM_LOCK_EX && !checkpointed); 3975 3976 if (checkpointed) 3977 return 1; 3978 3979 ocfs2_start_checkpoint(OCFS2_SB(ocfs2_metadata_cache_get_super(ci))); 3980 return 0; 3981 } 3982 3983 static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres, 3984 int new_level) 3985 { 3986 struct inode *inode = ocfs2_lock_res_inode(lockres); 3987 3988 return ocfs2_ci_checkpointed(INODE_CACHE(inode), lockres, new_level); 3989 } 3990 3991 static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres) 3992 { 3993 struct inode *inode = ocfs2_lock_res_inode(lockres); 3994 3995 __ocfs2_stuff_meta_lvb(inode); 3996 } 3997 3998 /* 3999 * Does the final reference drop on our dentry lock. Right now this 4000 * happens in the downconvert thread, but we could choose to simplify the 4001 * dlmglue API and push these off to the ocfs2_wq in the future. 4002 */ 4003 static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb, 4004 struct ocfs2_lock_res *lockres) 4005 { 4006 struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres); 4007 ocfs2_dentry_lock_put(osb, dl); 4008 } 4009 4010 /* 4011 * d_delete() matching dentries before the lock downconvert. 4012 * 4013 * At this point, any process waiting to destroy the 4014 * dentry_lock due to last ref count is stopped by the 4015 * OCFS2_LOCK_QUEUED flag. 4016 * 4017 * We have two potential problems 4018 * 4019 * 1) If we do the last reference drop on our dentry_lock (via dput) 4020 * we'll wind up in ocfs2_release_dentry_lock(), waiting on 4021 * the downconvert to finish. Instead we take an elevated 4022 * reference and push the drop until after we've completed our 4023 * unblock processing. 4024 * 4025 * 2) There might be another process with a final reference, 4026 * waiting on us to finish processing. If this is the case, we 4027 * detect it and exit out - there's no more dentries anyway. 4028 */ 4029 static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres, 4030 int blocking) 4031 { 4032 struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres); 4033 struct ocfs2_inode_info *oi = OCFS2_I(dl->dl_inode); 4034 struct dentry *dentry; 4035 unsigned long flags; 4036 int extra_ref = 0; 4037 4038 /* 4039 * This node is blocking another node from getting a read 4040 * lock. This happens when we've renamed within a 4041 * directory. We've forced the other nodes to d_delete(), but 4042 * we never actually dropped our lock because it's still 4043 * valid. The downconvert code will retain a PR for this node, 4044 * so there's no further work to do. 4045 */ 4046 if (blocking == DLM_LOCK_PR) 4047 return UNBLOCK_CONTINUE; 4048 4049 /* 4050 * Mark this inode as potentially orphaned. The code in 4051 * ocfs2_delete_inode() will figure out whether it actually 4052 * needs to be freed or not. 4053 */ 4054 spin_lock(&oi->ip_lock); 4055 oi->ip_flags |= OCFS2_INODE_MAYBE_ORPHANED; 4056 spin_unlock(&oi->ip_lock); 4057 4058 /* 4059 * Yuck. We need to make sure however that the check of 4060 * OCFS2_LOCK_FREEING and the extra reference are atomic with 4061 * respect to a reference decrement or the setting of that 4062 * flag. 4063 */ 4064 spin_lock_irqsave(&lockres->l_lock, flags); 4065 spin_lock(&dentry_attach_lock); 4066 if (!(lockres->l_flags & OCFS2_LOCK_FREEING) 4067 && dl->dl_count) { 4068 dl->dl_count++; 4069 extra_ref = 1; 4070 } 4071 spin_unlock(&dentry_attach_lock); 4072 spin_unlock_irqrestore(&lockres->l_lock, flags); 4073 4074 mlog(0, "extra_ref = %d\n", extra_ref); 4075 4076 /* 4077 * We have a process waiting on us in ocfs2_dentry_iput(), 4078 * which means we can't have any more outstanding 4079 * aliases. There's no need to do any more work. 4080 */ 4081 if (!extra_ref) 4082 return UNBLOCK_CONTINUE; 4083 4084 spin_lock(&dentry_attach_lock); 4085 while (1) { 4086 dentry = ocfs2_find_local_alias(dl->dl_inode, 4087 dl->dl_parent_blkno, 1); 4088 if (!dentry) 4089 break; 4090 spin_unlock(&dentry_attach_lock); 4091 4092 if (S_ISDIR(dl->dl_inode->i_mode)) 4093 shrink_dcache_parent(dentry); 4094 4095 mlog(0, "d_delete(%pd);\n", dentry); 4096 4097 /* 4098 * The following dcache calls may do an 4099 * iput(). Normally we don't want that from the 4100 * downconverting thread, but in this case it's ok 4101 * because the requesting node already has an 4102 * exclusive lock on the inode, so it can't be queued 4103 * for a downconvert. 4104 */ 4105 d_delete(dentry); 4106 dput(dentry); 4107 4108 spin_lock(&dentry_attach_lock); 4109 } 4110 spin_unlock(&dentry_attach_lock); 4111 4112 /* 4113 * If we are the last holder of this dentry lock, there is no 4114 * reason to downconvert so skip straight to the unlock. 4115 */ 4116 if (dl->dl_count == 1) 4117 return UNBLOCK_STOP_POST; 4118 4119 return UNBLOCK_CONTINUE_POST; 4120 } 4121 4122 static int ocfs2_check_refcount_downconvert(struct ocfs2_lock_res *lockres, 4123 int new_level) 4124 { 4125 struct ocfs2_refcount_tree *tree = 4126 ocfs2_lock_res_refcount_tree(lockres); 4127 4128 return ocfs2_ci_checkpointed(&tree->rf_ci, lockres, new_level); 4129 } 4130 4131 static int ocfs2_refcount_convert_worker(struct ocfs2_lock_res *lockres, 4132 int blocking) 4133 { 4134 struct ocfs2_refcount_tree *tree = 4135 ocfs2_lock_res_refcount_tree(lockres); 4136 4137 ocfs2_metadata_cache_purge(&tree->rf_ci); 4138 4139 return UNBLOCK_CONTINUE; 4140 } 4141 4142 static void ocfs2_set_qinfo_lvb(struct ocfs2_lock_res *lockres) 4143 { 4144 struct ocfs2_qinfo_lvb *lvb; 4145 struct ocfs2_mem_dqinfo *oinfo = ocfs2_lock_res_qinfo(lockres); 4146 struct mem_dqinfo *info = sb_dqinfo(oinfo->dqi_gi.dqi_sb, 4147 oinfo->dqi_gi.dqi_type); 4148 4149 lvb = ocfs2_dlm_lvb(&lockres->l_lksb); 4150 lvb->lvb_version = OCFS2_QINFO_LVB_VERSION; 4151 lvb->lvb_bgrace = cpu_to_be32(info->dqi_bgrace); 4152 lvb->lvb_igrace = cpu_to_be32(info->dqi_igrace); 4153 lvb->lvb_syncms = cpu_to_be32(oinfo->dqi_syncms); 4154 lvb->lvb_blocks = cpu_to_be32(oinfo->dqi_gi.dqi_blocks); 4155 lvb->lvb_free_blk = cpu_to_be32(oinfo->dqi_gi.dqi_free_blk); 4156 lvb->lvb_free_entry = cpu_to_be32(oinfo->dqi_gi.dqi_free_entry); 4157 } 4158 4159 void ocfs2_qinfo_unlock(struct ocfs2_mem_dqinfo *oinfo, int ex) 4160 { 4161 struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock; 4162 struct ocfs2_super *osb = OCFS2_SB(oinfo->dqi_gi.dqi_sb); 4163 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 4164 4165 if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb)) 4166 ocfs2_cluster_unlock(osb, lockres, level); 4167 } 4168 4169 static int ocfs2_refresh_qinfo(struct ocfs2_mem_dqinfo *oinfo) 4170 { 4171 struct mem_dqinfo *info = sb_dqinfo(oinfo->dqi_gi.dqi_sb, 4172 oinfo->dqi_gi.dqi_type); 4173 struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock; 4174 struct ocfs2_qinfo_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb); 4175 struct buffer_head *bh = NULL; 4176 struct ocfs2_global_disk_dqinfo *gdinfo; 4177 int status = 0; 4178 4179 if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) && 4180 lvb->lvb_version == OCFS2_QINFO_LVB_VERSION) { 4181 info->dqi_bgrace = be32_to_cpu(lvb->lvb_bgrace); 4182 info->dqi_igrace = be32_to_cpu(lvb->lvb_igrace); 4183 oinfo->dqi_syncms = be32_to_cpu(lvb->lvb_syncms); 4184 oinfo->dqi_gi.dqi_blocks = be32_to_cpu(lvb->lvb_blocks); 4185 oinfo->dqi_gi.dqi_free_blk = be32_to_cpu(lvb->lvb_free_blk); 4186 oinfo->dqi_gi.dqi_free_entry = 4187 be32_to_cpu(lvb->lvb_free_entry); 4188 } else { 4189 status = ocfs2_read_quota_phys_block(oinfo->dqi_gqinode, 4190 oinfo->dqi_giblk, &bh); 4191 if (status) { 4192 mlog_errno(status); 4193 goto bail; 4194 } 4195 gdinfo = (struct ocfs2_global_disk_dqinfo *) 4196 (bh->b_data + OCFS2_GLOBAL_INFO_OFF); 4197 info->dqi_bgrace = le32_to_cpu(gdinfo->dqi_bgrace); 4198 info->dqi_igrace = le32_to_cpu(gdinfo->dqi_igrace); 4199 oinfo->dqi_syncms = le32_to_cpu(gdinfo->dqi_syncms); 4200 oinfo->dqi_gi.dqi_blocks = le32_to_cpu(gdinfo->dqi_blocks); 4201 oinfo->dqi_gi.dqi_free_blk = le32_to_cpu(gdinfo->dqi_free_blk); 4202 oinfo->dqi_gi.dqi_free_entry = 4203 le32_to_cpu(gdinfo->dqi_free_entry); 4204 brelse(bh); 4205 ocfs2_track_lock_refresh(lockres); 4206 } 4207 4208 bail: 4209 return status; 4210 } 4211 4212 /* Lock quota info, this function expects at least shared lock on the quota file 4213 * so that we can safely refresh quota info from disk. */ 4214 int ocfs2_qinfo_lock(struct ocfs2_mem_dqinfo *oinfo, int ex) 4215 { 4216 struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock; 4217 struct ocfs2_super *osb = OCFS2_SB(oinfo->dqi_gi.dqi_sb); 4218 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 4219 int status = 0; 4220 4221 /* On RO devices, locking really isn't needed... */ 4222 if (ocfs2_is_hard_readonly(osb)) { 4223 if (ex) 4224 status = -EROFS; 4225 goto bail; 4226 } 4227 if (ocfs2_mount_local(osb)) 4228 goto bail; 4229 4230 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0); 4231 if (status < 0) { 4232 mlog_errno(status); 4233 goto bail; 4234 } 4235 if (!ocfs2_should_refresh_lock_res(lockres)) 4236 goto bail; 4237 /* OK, we have the lock but we need to refresh the quota info */ 4238 status = ocfs2_refresh_qinfo(oinfo); 4239 if (status) 4240 ocfs2_qinfo_unlock(oinfo, ex); 4241 ocfs2_complete_lock_res_refresh(lockres, status); 4242 bail: 4243 return status; 4244 } 4245 4246 int ocfs2_refcount_lock(struct ocfs2_refcount_tree *ref_tree, int ex) 4247 { 4248 int status; 4249 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 4250 struct ocfs2_lock_res *lockres = &ref_tree->rf_lockres; 4251 struct ocfs2_super *osb = lockres->l_priv; 4252 4253 4254 if (ocfs2_is_hard_readonly(osb)) 4255 return -EROFS; 4256 4257 if (ocfs2_mount_local(osb)) 4258 return 0; 4259 4260 status = ocfs2_cluster_lock(osb, lockres, level, 0, 0); 4261 if (status < 0) 4262 mlog_errno(status); 4263 4264 return status; 4265 } 4266 4267 void ocfs2_refcount_unlock(struct ocfs2_refcount_tree *ref_tree, int ex) 4268 { 4269 int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; 4270 struct ocfs2_lock_res *lockres = &ref_tree->rf_lockres; 4271 struct ocfs2_super *osb = lockres->l_priv; 4272 4273 if (!ocfs2_mount_local(osb)) 4274 ocfs2_cluster_unlock(osb, lockres, level); 4275 } 4276 4277 static void ocfs2_process_blocked_lock(struct ocfs2_super *osb, 4278 struct ocfs2_lock_res *lockres) 4279 { 4280 int status; 4281 struct ocfs2_unblock_ctl ctl = {0, 0,}; 4282 unsigned long flags; 4283 4284 /* Our reference to the lockres in this function can be 4285 * considered valid until we remove the OCFS2_LOCK_QUEUED 4286 * flag. */ 4287 4288 BUG_ON(!lockres); 4289 BUG_ON(!lockres->l_ops); 4290 4291 mlog(ML_BASTS, "lockres %s blocked\n", lockres->l_name); 4292 4293 /* Detect whether a lock has been marked as going away while 4294 * the downconvert thread was processing other things. A lock can 4295 * still be marked with OCFS2_LOCK_FREEING after this check, 4296 * but short circuiting here will still save us some 4297 * performance. */ 4298 spin_lock_irqsave(&lockres->l_lock, flags); 4299 if (lockres->l_flags & OCFS2_LOCK_FREEING) 4300 goto unqueue; 4301 spin_unlock_irqrestore(&lockres->l_lock, flags); 4302 4303 status = ocfs2_unblock_lock(osb, lockres, &ctl); 4304 if (status < 0) 4305 mlog_errno(status); 4306 4307 spin_lock_irqsave(&lockres->l_lock, flags); 4308 unqueue: 4309 if (lockres->l_flags & OCFS2_LOCK_FREEING || !ctl.requeue) { 4310 lockres_clear_flags(lockres, OCFS2_LOCK_QUEUED); 4311 } else 4312 ocfs2_schedule_blocked_lock(osb, lockres); 4313 4314 mlog(ML_BASTS, "lockres %s, requeue = %s.\n", lockres->l_name, 4315 ctl.requeue ? "yes" : "no"); 4316 spin_unlock_irqrestore(&lockres->l_lock, flags); 4317 4318 if (ctl.unblock_action != UNBLOCK_CONTINUE 4319 && lockres->l_ops->post_unlock) 4320 lockres->l_ops->post_unlock(osb, lockres); 4321 } 4322 4323 static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb, 4324 struct ocfs2_lock_res *lockres) 4325 { 4326 unsigned long flags; 4327 4328 assert_spin_locked(&lockres->l_lock); 4329 4330 if (lockres->l_flags & OCFS2_LOCK_FREEING) { 4331 /* Do not schedule a lock for downconvert when it's on 4332 * the way to destruction - any nodes wanting access 4333 * to the resource will get it soon. */ 4334 mlog(ML_BASTS, "lockres %s won't be scheduled: flags 0x%lx\n", 4335 lockres->l_name, lockres->l_flags); 4336 return; 4337 } 4338 4339 lockres_or_flags(lockres, OCFS2_LOCK_QUEUED); 4340 4341 spin_lock_irqsave(&osb->dc_task_lock, flags); 4342 if (list_empty(&lockres->l_blocked_list)) { 4343 list_add_tail(&lockres->l_blocked_list, 4344 &osb->blocked_lock_list); 4345 osb->blocked_lock_count++; 4346 } 4347 spin_unlock_irqrestore(&osb->dc_task_lock, flags); 4348 } 4349 4350 static void ocfs2_downconvert_thread_do_work(struct ocfs2_super *osb) 4351 { 4352 unsigned long processed; 4353 unsigned long flags; 4354 struct ocfs2_lock_res *lockres; 4355 4356 spin_lock_irqsave(&osb->dc_task_lock, flags); 4357 /* grab this early so we know to try again if a state change and 4358 * wake happens part-way through our work */ 4359 osb->dc_work_sequence = osb->dc_wake_sequence; 4360 4361 processed = osb->blocked_lock_count; 4362 /* 4363 * blocked lock processing in this loop might call iput which can 4364 * remove items off osb->blocked_lock_list. Downconvert up to 4365 * 'processed' number of locks, but stop short if we had some 4366 * removed in ocfs2_mark_lockres_freeing when downconverting. 4367 */ 4368 while (processed && !list_empty(&osb->blocked_lock_list)) { 4369 lockres = list_entry(osb->blocked_lock_list.next, 4370 struct ocfs2_lock_res, l_blocked_list); 4371 list_del_init(&lockres->l_blocked_list); 4372 osb->blocked_lock_count--; 4373 spin_unlock_irqrestore(&osb->dc_task_lock, flags); 4374 4375 BUG_ON(!processed); 4376 processed--; 4377 4378 ocfs2_process_blocked_lock(osb, lockres); 4379 4380 spin_lock_irqsave(&osb->dc_task_lock, flags); 4381 } 4382 spin_unlock_irqrestore(&osb->dc_task_lock, flags); 4383 } 4384 4385 static int ocfs2_downconvert_thread_lists_empty(struct ocfs2_super *osb) 4386 { 4387 int empty = 0; 4388 unsigned long flags; 4389 4390 spin_lock_irqsave(&osb->dc_task_lock, flags); 4391 if (list_empty(&osb->blocked_lock_list)) 4392 empty = 1; 4393 4394 spin_unlock_irqrestore(&osb->dc_task_lock, flags); 4395 return empty; 4396 } 4397 4398 static int ocfs2_downconvert_thread_should_wake(struct ocfs2_super *osb) 4399 { 4400 int should_wake = 0; 4401 unsigned long flags; 4402 4403 spin_lock_irqsave(&osb->dc_task_lock, flags); 4404 if (osb->dc_work_sequence != osb->dc_wake_sequence) 4405 should_wake = 1; 4406 spin_unlock_irqrestore(&osb->dc_task_lock, flags); 4407 4408 return should_wake; 4409 } 4410 4411 static int ocfs2_downconvert_thread(void *arg) 4412 { 4413 struct ocfs2_super *osb = arg; 4414 4415 /* only quit once we've been asked to stop and there is no more 4416 * work available */ 4417 while (!(kthread_should_stop() && 4418 ocfs2_downconvert_thread_lists_empty(osb))) { 4419 4420 wait_event_interruptible(osb->dc_event, 4421 ocfs2_downconvert_thread_should_wake(osb) || 4422 kthread_should_stop()); 4423 4424 mlog(0, "downconvert_thread: awoken\n"); 4425 4426 ocfs2_downconvert_thread_do_work(osb); 4427 } 4428 4429 osb->dc_task = NULL; 4430 return 0; 4431 } 4432 4433 void ocfs2_wake_downconvert_thread(struct ocfs2_super *osb) 4434 { 4435 unsigned long flags; 4436 4437 spin_lock_irqsave(&osb->dc_task_lock, flags); 4438 /* make sure the voting thread gets a swipe at whatever changes 4439 * the caller may have made to the voting state */ 4440 osb->dc_wake_sequence++; 4441 spin_unlock_irqrestore(&osb->dc_task_lock, flags); 4442 wake_up(&osb->dc_event); 4443 } 4444