1 /****************************************************************************** 2 ******************************************************************************* 3 ** 4 ** Copyright (C) 2005-2010 Red Hat, Inc. All rights reserved. 5 ** 6 ** This copyrighted material is made available to anyone wishing to use, 7 ** modify, copy, or redistribute it subject to the terms and conditions 8 ** of the GNU General Public License v.2. 9 ** 10 ******************************************************************************* 11 ******************************************************************************/ 12 13 /* Central locking logic has four stages: 14 15 dlm_lock() 16 dlm_unlock() 17 18 request_lock(ls, lkb) 19 convert_lock(ls, lkb) 20 unlock_lock(ls, lkb) 21 cancel_lock(ls, lkb) 22 23 _request_lock(r, lkb) 24 _convert_lock(r, lkb) 25 _unlock_lock(r, lkb) 26 _cancel_lock(r, lkb) 27 28 do_request(r, lkb) 29 do_convert(r, lkb) 30 do_unlock(r, lkb) 31 do_cancel(r, lkb) 32 33 Stage 1 (lock, unlock) is mainly about checking input args and 34 splitting into one of the four main operations: 35 36 dlm_lock = request_lock 37 dlm_lock+CONVERT = convert_lock 38 dlm_unlock = unlock_lock 39 dlm_unlock+CANCEL = cancel_lock 40 41 Stage 2, xxxx_lock(), just finds and locks the relevant rsb which is 42 provided to the next stage. 43 44 Stage 3, _xxxx_lock(), determines if the operation is local or remote. 45 When remote, it calls send_xxxx(), when local it calls do_xxxx(). 46 47 Stage 4, do_xxxx(), is the guts of the operation. It manipulates the 48 given rsb and lkb and queues callbacks. 49 50 For remote operations, send_xxxx() results in the corresponding do_xxxx() 51 function being executed on the remote node. The connecting send/receive 52 calls on local (L) and remote (R) nodes: 53 54 L: send_xxxx() -> R: receive_xxxx() 55 R: do_xxxx() 56 L: receive_xxxx_reply() <- R: send_xxxx_reply() 57 */ 58 #include <linux/types.h> 59 #include <linux/rbtree.h> 60 #include <linux/slab.h> 61 #include "dlm_internal.h" 62 #include <linux/dlm_device.h> 63 #include "memory.h" 64 #include "lowcomms.h" 65 #include "requestqueue.h" 66 #include "util.h" 67 #include "dir.h" 68 #include "member.h" 69 #include "lockspace.h" 70 #include "ast.h" 71 #include "lock.h" 72 #include "rcom.h" 73 #include "recover.h" 74 #include "lvb_table.h" 75 #include "user.h" 76 #include "config.h" 77 78 static int send_request(struct dlm_rsb *r, struct dlm_lkb *lkb); 79 static int send_convert(struct dlm_rsb *r, struct dlm_lkb *lkb); 80 static int send_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb); 81 static int send_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb); 82 static int send_grant(struct dlm_rsb *r, struct dlm_lkb *lkb); 83 static int send_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int mode); 84 static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb); 85 static int send_remove(struct dlm_rsb *r); 86 static int _request_lock(struct dlm_rsb *r, struct dlm_lkb *lkb); 87 static int _cancel_lock(struct dlm_rsb *r, struct dlm_lkb *lkb); 88 static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, 89 struct dlm_message *ms); 90 static int receive_extralen(struct dlm_message *ms); 91 static void do_purge(struct dlm_ls *ls, int nodeid, int pid); 92 static void del_timeout(struct dlm_lkb *lkb); 93 94 /* 95 * Lock compatibilty matrix - thanks Steve 96 * UN = Unlocked state. Not really a state, used as a flag 97 * PD = Padding. Used to make the matrix a nice power of two in size 98 * Other states are the same as the VMS DLM. 99 * Usage: matrix[grmode+1][rqmode+1] (although m[rq+1][gr+1] is the same) 100 */ 101 102 static const int __dlm_compat_matrix[8][8] = { 103 /* UN NL CR CW PR PW EX PD */ 104 {1, 1, 1, 1, 1, 1, 1, 0}, /* UN */ 105 {1, 1, 1, 1, 1, 1, 1, 0}, /* NL */ 106 {1, 1, 1, 1, 1, 1, 0, 0}, /* CR */ 107 {1, 1, 1, 1, 0, 0, 0, 0}, /* CW */ 108 {1, 1, 1, 0, 1, 0, 0, 0}, /* PR */ 109 {1, 1, 1, 0, 0, 0, 0, 0}, /* PW */ 110 {1, 1, 0, 0, 0, 0, 0, 0}, /* EX */ 111 {0, 0, 0, 0, 0, 0, 0, 0} /* PD */ 112 }; 113 114 /* 115 * This defines the direction of transfer of LVB data. 116 * Granted mode is the row; requested mode is the column. 117 * Usage: matrix[grmode+1][rqmode+1] 118 * 1 = LVB is returned to the caller 119 * 0 = LVB is written to the resource 120 * -1 = nothing happens to the LVB 121 */ 122 123 const int dlm_lvb_operations[8][8] = { 124 /* UN NL CR CW PR PW EX PD*/ 125 { -1, 1, 1, 1, 1, 1, 1, -1 }, /* UN */ 126 { -1, 1, 1, 1, 1, 1, 1, 0 }, /* NL */ 127 { -1, -1, 1, 1, 1, 1, 1, 0 }, /* CR */ 128 { -1, -1, -1, 1, 1, 1, 1, 0 }, /* CW */ 129 { -1, -1, -1, -1, 1, 1, 1, 0 }, /* PR */ 130 { -1, 0, 0, 0, 0, 0, 1, 0 }, /* PW */ 131 { -1, 0, 0, 0, 0, 0, 0, 0 }, /* EX */ 132 { -1, 0, 0, 0, 0, 0, 0, 0 } /* PD */ 133 }; 134 135 #define modes_compat(gr, rq) \ 136 __dlm_compat_matrix[(gr)->lkb_grmode + 1][(rq)->lkb_rqmode + 1] 137 138 int dlm_modes_compat(int mode1, int mode2) 139 { 140 return __dlm_compat_matrix[mode1 + 1][mode2 + 1]; 141 } 142 143 /* 144 * Compatibility matrix for conversions with QUECVT set. 145 * Granted mode is the row; requested mode is the column. 146 * Usage: matrix[grmode+1][rqmode+1] 147 */ 148 149 static const int __quecvt_compat_matrix[8][8] = { 150 /* UN NL CR CW PR PW EX PD */ 151 {0, 0, 0, 0, 0, 0, 0, 0}, /* UN */ 152 {0, 0, 1, 1, 1, 1, 1, 0}, /* NL */ 153 {0, 0, 0, 1, 1, 1, 1, 0}, /* CR */ 154 {0, 0, 0, 0, 1, 1, 1, 0}, /* CW */ 155 {0, 0, 0, 1, 0, 1, 1, 0}, /* PR */ 156 {0, 0, 0, 0, 0, 0, 1, 0}, /* PW */ 157 {0, 0, 0, 0, 0, 0, 0, 0}, /* EX */ 158 {0, 0, 0, 0, 0, 0, 0, 0} /* PD */ 159 }; 160 161 void dlm_print_lkb(struct dlm_lkb *lkb) 162 { 163 printk(KERN_ERR "lkb: nodeid %d id %x remid %x exflags %x flags %x\n" 164 " status %d rqmode %d grmode %d wait_type %d\n", 165 lkb->lkb_nodeid, lkb->lkb_id, lkb->lkb_remid, lkb->lkb_exflags, 166 lkb->lkb_flags, lkb->lkb_status, lkb->lkb_rqmode, 167 lkb->lkb_grmode, lkb->lkb_wait_type); 168 } 169 170 static void dlm_print_rsb(struct dlm_rsb *r) 171 { 172 printk(KERN_ERR "rsb: nodeid %d flags %lx first %x rlc %d name %s\n", 173 r->res_nodeid, r->res_flags, r->res_first_lkid, 174 r->res_recover_locks_count, r->res_name); 175 } 176 177 void dlm_dump_rsb(struct dlm_rsb *r) 178 { 179 struct dlm_lkb *lkb; 180 181 dlm_print_rsb(r); 182 183 printk(KERN_ERR "rsb: root_list empty %d recover_list empty %d\n", 184 list_empty(&r->res_root_list), list_empty(&r->res_recover_list)); 185 printk(KERN_ERR "rsb lookup list\n"); 186 list_for_each_entry(lkb, &r->res_lookup, lkb_rsb_lookup) 187 dlm_print_lkb(lkb); 188 printk(KERN_ERR "rsb grant queue:\n"); 189 list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue) 190 dlm_print_lkb(lkb); 191 printk(KERN_ERR "rsb convert queue:\n"); 192 list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue) 193 dlm_print_lkb(lkb); 194 printk(KERN_ERR "rsb wait queue:\n"); 195 list_for_each_entry(lkb, &r->res_waitqueue, lkb_statequeue) 196 dlm_print_lkb(lkb); 197 } 198 199 /* Threads cannot use the lockspace while it's being recovered */ 200 201 static inline void dlm_lock_recovery(struct dlm_ls *ls) 202 { 203 down_read(&ls->ls_in_recovery); 204 } 205 206 void dlm_unlock_recovery(struct dlm_ls *ls) 207 { 208 up_read(&ls->ls_in_recovery); 209 } 210 211 int dlm_lock_recovery_try(struct dlm_ls *ls) 212 { 213 return down_read_trylock(&ls->ls_in_recovery); 214 } 215 216 static inline int can_be_queued(struct dlm_lkb *lkb) 217 { 218 return !(lkb->lkb_exflags & DLM_LKF_NOQUEUE); 219 } 220 221 static inline int force_blocking_asts(struct dlm_lkb *lkb) 222 { 223 return (lkb->lkb_exflags & DLM_LKF_NOQUEUEBAST); 224 } 225 226 static inline int is_demoted(struct dlm_lkb *lkb) 227 { 228 return (lkb->lkb_sbflags & DLM_SBF_DEMOTED); 229 } 230 231 static inline int is_altmode(struct dlm_lkb *lkb) 232 { 233 return (lkb->lkb_sbflags & DLM_SBF_ALTMODE); 234 } 235 236 static inline int is_granted(struct dlm_lkb *lkb) 237 { 238 return (lkb->lkb_status == DLM_LKSTS_GRANTED); 239 } 240 241 static inline int is_remote(struct dlm_rsb *r) 242 { 243 DLM_ASSERT(r->res_nodeid >= 0, dlm_print_rsb(r);); 244 return !!r->res_nodeid; 245 } 246 247 static inline int is_process_copy(struct dlm_lkb *lkb) 248 { 249 return (lkb->lkb_nodeid && !(lkb->lkb_flags & DLM_IFL_MSTCPY)); 250 } 251 252 static inline int is_master_copy(struct dlm_lkb *lkb) 253 { 254 if (lkb->lkb_flags & DLM_IFL_MSTCPY) 255 DLM_ASSERT(lkb->lkb_nodeid, dlm_print_lkb(lkb);); 256 return (lkb->lkb_flags & DLM_IFL_MSTCPY) ? 1 : 0; 257 } 258 259 static inline int middle_conversion(struct dlm_lkb *lkb) 260 { 261 if ((lkb->lkb_grmode==DLM_LOCK_PR && lkb->lkb_rqmode==DLM_LOCK_CW) || 262 (lkb->lkb_rqmode==DLM_LOCK_PR && lkb->lkb_grmode==DLM_LOCK_CW)) 263 return 1; 264 return 0; 265 } 266 267 static inline int down_conversion(struct dlm_lkb *lkb) 268 { 269 return (!middle_conversion(lkb) && lkb->lkb_rqmode < lkb->lkb_grmode); 270 } 271 272 static inline int is_overlap_unlock(struct dlm_lkb *lkb) 273 { 274 return lkb->lkb_flags & DLM_IFL_OVERLAP_UNLOCK; 275 } 276 277 static inline int is_overlap_cancel(struct dlm_lkb *lkb) 278 { 279 return lkb->lkb_flags & DLM_IFL_OVERLAP_CANCEL; 280 } 281 282 static inline int is_overlap(struct dlm_lkb *lkb) 283 { 284 return (lkb->lkb_flags & (DLM_IFL_OVERLAP_UNLOCK | 285 DLM_IFL_OVERLAP_CANCEL)); 286 } 287 288 static void queue_cast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv) 289 { 290 if (is_master_copy(lkb)) 291 return; 292 293 del_timeout(lkb); 294 295 DLM_ASSERT(lkb->lkb_lksb, dlm_print_lkb(lkb);); 296 297 /* if the operation was a cancel, then return -DLM_ECANCEL, if a 298 timeout caused the cancel then return -ETIMEDOUT */ 299 if (rv == -DLM_ECANCEL && (lkb->lkb_flags & DLM_IFL_TIMEOUT_CANCEL)) { 300 lkb->lkb_flags &= ~DLM_IFL_TIMEOUT_CANCEL; 301 rv = -ETIMEDOUT; 302 } 303 304 if (rv == -DLM_ECANCEL && (lkb->lkb_flags & DLM_IFL_DEADLOCK_CANCEL)) { 305 lkb->lkb_flags &= ~DLM_IFL_DEADLOCK_CANCEL; 306 rv = -EDEADLK; 307 } 308 309 dlm_add_cb(lkb, DLM_CB_CAST, lkb->lkb_grmode, rv, lkb->lkb_sbflags); 310 } 311 312 static inline void queue_cast_overlap(struct dlm_rsb *r, struct dlm_lkb *lkb) 313 { 314 queue_cast(r, lkb, 315 is_overlap_unlock(lkb) ? -DLM_EUNLOCK : -DLM_ECANCEL); 316 } 317 318 static void queue_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rqmode) 319 { 320 if (is_master_copy(lkb)) { 321 send_bast(r, lkb, rqmode); 322 } else { 323 dlm_add_cb(lkb, DLM_CB_BAST, rqmode, 0, 0); 324 } 325 } 326 327 /* 328 * Basic operations on rsb's and lkb's 329 */ 330 331 static int pre_rsb_struct(struct dlm_ls *ls) 332 { 333 struct dlm_rsb *r1, *r2; 334 int count = 0; 335 336 spin_lock(&ls->ls_new_rsb_spin); 337 if (ls->ls_new_rsb_count > dlm_config.ci_new_rsb_count / 2) { 338 spin_unlock(&ls->ls_new_rsb_spin); 339 return 0; 340 } 341 spin_unlock(&ls->ls_new_rsb_spin); 342 343 r1 = dlm_allocate_rsb(ls); 344 r2 = dlm_allocate_rsb(ls); 345 346 spin_lock(&ls->ls_new_rsb_spin); 347 if (r1) { 348 list_add(&r1->res_hashchain, &ls->ls_new_rsb); 349 ls->ls_new_rsb_count++; 350 } 351 if (r2) { 352 list_add(&r2->res_hashchain, &ls->ls_new_rsb); 353 ls->ls_new_rsb_count++; 354 } 355 count = ls->ls_new_rsb_count; 356 spin_unlock(&ls->ls_new_rsb_spin); 357 358 if (!count) 359 return -ENOMEM; 360 return 0; 361 } 362 363 /* If ls->ls_new_rsb is empty, return -EAGAIN, so the caller can 364 unlock any spinlocks, go back and call pre_rsb_struct again. 365 Otherwise, take an rsb off the list and return it. */ 366 367 static int get_rsb_struct(struct dlm_ls *ls, char *name, int len, 368 struct dlm_rsb **r_ret) 369 { 370 struct dlm_rsb *r; 371 int count; 372 373 spin_lock(&ls->ls_new_rsb_spin); 374 if (list_empty(&ls->ls_new_rsb)) { 375 count = ls->ls_new_rsb_count; 376 spin_unlock(&ls->ls_new_rsb_spin); 377 log_debug(ls, "find_rsb retry %d %d %s", 378 count, dlm_config.ci_new_rsb_count, name); 379 return -EAGAIN; 380 } 381 382 r = list_first_entry(&ls->ls_new_rsb, struct dlm_rsb, res_hashchain); 383 list_del(&r->res_hashchain); 384 /* Convert the empty list_head to a NULL rb_node for tree usage: */ 385 memset(&r->res_hashnode, 0, sizeof(struct rb_node)); 386 ls->ls_new_rsb_count--; 387 spin_unlock(&ls->ls_new_rsb_spin); 388 389 r->res_ls = ls; 390 r->res_length = len; 391 memcpy(r->res_name, name, len); 392 mutex_init(&r->res_mutex); 393 394 INIT_LIST_HEAD(&r->res_lookup); 395 INIT_LIST_HEAD(&r->res_grantqueue); 396 INIT_LIST_HEAD(&r->res_convertqueue); 397 INIT_LIST_HEAD(&r->res_waitqueue); 398 INIT_LIST_HEAD(&r->res_root_list); 399 INIT_LIST_HEAD(&r->res_recover_list); 400 401 *r_ret = r; 402 return 0; 403 } 404 405 static int rsb_cmp(struct dlm_rsb *r, const char *name, int nlen) 406 { 407 char maxname[DLM_RESNAME_MAXLEN]; 408 409 memset(maxname, 0, DLM_RESNAME_MAXLEN); 410 memcpy(maxname, name, nlen); 411 return memcmp(r->res_name, maxname, DLM_RESNAME_MAXLEN); 412 } 413 414 static int search_rsb_tree(struct rb_root *tree, char *name, int len, 415 unsigned int flags, struct dlm_rsb **r_ret) 416 { 417 struct rb_node *node = tree->rb_node; 418 struct dlm_rsb *r; 419 int error = 0; 420 int rc; 421 422 while (node) { 423 r = rb_entry(node, struct dlm_rsb, res_hashnode); 424 rc = rsb_cmp(r, name, len); 425 if (rc < 0) 426 node = node->rb_left; 427 else if (rc > 0) 428 node = node->rb_right; 429 else 430 goto found; 431 } 432 *r_ret = NULL; 433 return -EBADR; 434 435 found: 436 if (r->res_nodeid && (flags & R_MASTER)) 437 error = -ENOTBLK; 438 *r_ret = r; 439 return error; 440 } 441 442 static int rsb_insert(struct dlm_rsb *rsb, struct rb_root *tree) 443 { 444 struct rb_node **newn = &tree->rb_node; 445 struct rb_node *parent = NULL; 446 int rc; 447 448 while (*newn) { 449 struct dlm_rsb *cur = rb_entry(*newn, struct dlm_rsb, 450 res_hashnode); 451 452 parent = *newn; 453 rc = rsb_cmp(cur, rsb->res_name, rsb->res_length); 454 if (rc < 0) 455 newn = &parent->rb_left; 456 else if (rc > 0) 457 newn = &parent->rb_right; 458 else { 459 log_print("rsb_insert match"); 460 dlm_dump_rsb(rsb); 461 dlm_dump_rsb(cur); 462 return -EEXIST; 463 } 464 } 465 466 rb_link_node(&rsb->res_hashnode, parent, newn); 467 rb_insert_color(&rsb->res_hashnode, tree); 468 return 0; 469 } 470 471 static int _search_rsb(struct dlm_ls *ls, char *name, int len, int b, 472 unsigned int flags, struct dlm_rsb **r_ret) 473 { 474 struct dlm_rsb *r; 475 int error; 476 477 error = search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, flags, &r); 478 if (!error) { 479 kref_get(&r->res_ref); 480 goto out; 481 } 482 error = search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, flags, &r); 483 if (error) 484 goto out; 485 486 rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss); 487 error = rsb_insert(r, &ls->ls_rsbtbl[b].keep); 488 if (error) 489 return error; 490 491 if (dlm_no_directory(ls)) 492 goto out; 493 494 if (r->res_nodeid == -1) { 495 rsb_clear_flag(r, RSB_MASTER_UNCERTAIN); 496 r->res_first_lkid = 0; 497 } else if (r->res_nodeid > 0) { 498 rsb_set_flag(r, RSB_MASTER_UNCERTAIN); 499 r->res_first_lkid = 0; 500 } else { 501 DLM_ASSERT(r->res_nodeid == 0, dlm_print_rsb(r);); 502 DLM_ASSERT(!rsb_flag(r, RSB_MASTER_UNCERTAIN),); 503 } 504 out: 505 *r_ret = r; 506 return error; 507 } 508 509 /* 510 * Find rsb in rsbtbl and potentially create/add one 511 * 512 * Delaying the release of rsb's has a similar benefit to applications keeping 513 * NL locks on an rsb, but without the guarantee that the cached master value 514 * will still be valid when the rsb is reused. Apps aren't always smart enough 515 * to keep NL locks on an rsb that they may lock again shortly; this can lead 516 * to excessive master lookups and removals if we don't delay the release. 517 * 518 * Searching for an rsb means looking through both the normal list and toss 519 * list. When found on the toss list the rsb is moved to the normal list with 520 * ref count of 1; when found on normal list the ref count is incremented. 521 */ 522 523 static int find_rsb(struct dlm_ls *ls, char *name, int namelen, 524 unsigned int flags, struct dlm_rsb **r_ret) 525 { 526 struct dlm_rsb *r = NULL; 527 uint32_t hash, bucket; 528 int error; 529 530 if (namelen > DLM_RESNAME_MAXLEN) { 531 error = -EINVAL; 532 goto out; 533 } 534 535 if (dlm_no_directory(ls)) 536 flags |= R_CREATE; 537 538 hash = jhash(name, namelen, 0); 539 bucket = hash & (ls->ls_rsbtbl_size - 1); 540 541 retry: 542 if (flags & R_CREATE) { 543 error = pre_rsb_struct(ls); 544 if (error < 0) 545 goto out; 546 } 547 548 spin_lock(&ls->ls_rsbtbl[bucket].lock); 549 550 error = _search_rsb(ls, name, namelen, bucket, flags, &r); 551 if (!error) 552 goto out_unlock; 553 554 if (error == -EBADR && !(flags & R_CREATE)) 555 goto out_unlock; 556 557 /* the rsb was found but wasn't a master copy */ 558 if (error == -ENOTBLK) 559 goto out_unlock; 560 561 error = get_rsb_struct(ls, name, namelen, &r); 562 if (error == -EAGAIN) { 563 spin_unlock(&ls->ls_rsbtbl[bucket].lock); 564 goto retry; 565 } 566 if (error) 567 goto out_unlock; 568 569 r->res_hash = hash; 570 r->res_bucket = bucket; 571 r->res_nodeid = -1; 572 kref_init(&r->res_ref); 573 574 /* With no directory, the master can be set immediately */ 575 if (dlm_no_directory(ls)) { 576 int nodeid = dlm_dir_nodeid(r); 577 if (nodeid == dlm_our_nodeid()) 578 nodeid = 0; 579 r->res_nodeid = nodeid; 580 } 581 error = rsb_insert(r, &ls->ls_rsbtbl[bucket].keep); 582 out_unlock: 583 spin_unlock(&ls->ls_rsbtbl[bucket].lock); 584 out: 585 *r_ret = r; 586 return error; 587 } 588 589 /* This is only called to add a reference when the code already holds 590 a valid reference to the rsb, so there's no need for locking. */ 591 592 static inline void hold_rsb(struct dlm_rsb *r) 593 { 594 kref_get(&r->res_ref); 595 } 596 597 void dlm_hold_rsb(struct dlm_rsb *r) 598 { 599 hold_rsb(r); 600 } 601 602 static void toss_rsb(struct kref *kref) 603 { 604 struct dlm_rsb *r = container_of(kref, struct dlm_rsb, res_ref); 605 struct dlm_ls *ls = r->res_ls; 606 607 DLM_ASSERT(list_empty(&r->res_root_list), dlm_print_rsb(r);); 608 kref_init(&r->res_ref); 609 rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[r->res_bucket].keep); 610 rsb_insert(r, &ls->ls_rsbtbl[r->res_bucket].toss); 611 r->res_toss_time = jiffies; 612 if (r->res_lvbptr) { 613 dlm_free_lvb(r->res_lvbptr); 614 r->res_lvbptr = NULL; 615 } 616 } 617 618 /* When all references to the rsb are gone it's transferred to 619 the tossed list for later disposal. */ 620 621 static void put_rsb(struct dlm_rsb *r) 622 { 623 struct dlm_ls *ls = r->res_ls; 624 uint32_t bucket = r->res_bucket; 625 626 spin_lock(&ls->ls_rsbtbl[bucket].lock); 627 kref_put(&r->res_ref, toss_rsb); 628 spin_unlock(&ls->ls_rsbtbl[bucket].lock); 629 } 630 631 void dlm_put_rsb(struct dlm_rsb *r) 632 { 633 put_rsb(r); 634 } 635 636 /* See comment for unhold_lkb */ 637 638 static void unhold_rsb(struct dlm_rsb *r) 639 { 640 int rv; 641 rv = kref_put(&r->res_ref, toss_rsb); 642 DLM_ASSERT(!rv, dlm_dump_rsb(r);); 643 } 644 645 static void kill_rsb(struct kref *kref) 646 { 647 struct dlm_rsb *r = container_of(kref, struct dlm_rsb, res_ref); 648 649 /* All work is done after the return from kref_put() so we 650 can release the write_lock before the remove and free. */ 651 652 DLM_ASSERT(list_empty(&r->res_lookup), dlm_dump_rsb(r);); 653 DLM_ASSERT(list_empty(&r->res_grantqueue), dlm_dump_rsb(r);); 654 DLM_ASSERT(list_empty(&r->res_convertqueue), dlm_dump_rsb(r);); 655 DLM_ASSERT(list_empty(&r->res_waitqueue), dlm_dump_rsb(r);); 656 DLM_ASSERT(list_empty(&r->res_root_list), dlm_dump_rsb(r);); 657 DLM_ASSERT(list_empty(&r->res_recover_list), dlm_dump_rsb(r);); 658 } 659 660 /* Attaching/detaching lkb's from rsb's is for rsb reference counting. 661 The rsb must exist as long as any lkb's for it do. */ 662 663 static void attach_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb) 664 { 665 hold_rsb(r); 666 lkb->lkb_resource = r; 667 } 668 669 static void detach_lkb(struct dlm_lkb *lkb) 670 { 671 if (lkb->lkb_resource) { 672 put_rsb(lkb->lkb_resource); 673 lkb->lkb_resource = NULL; 674 } 675 } 676 677 static int create_lkb(struct dlm_ls *ls, struct dlm_lkb **lkb_ret) 678 { 679 struct dlm_lkb *lkb; 680 int rv, id; 681 682 lkb = dlm_allocate_lkb(ls); 683 if (!lkb) 684 return -ENOMEM; 685 686 lkb->lkb_nodeid = -1; 687 lkb->lkb_grmode = DLM_LOCK_IV; 688 kref_init(&lkb->lkb_ref); 689 INIT_LIST_HEAD(&lkb->lkb_ownqueue); 690 INIT_LIST_HEAD(&lkb->lkb_rsb_lookup); 691 INIT_LIST_HEAD(&lkb->lkb_time_list); 692 INIT_LIST_HEAD(&lkb->lkb_cb_list); 693 mutex_init(&lkb->lkb_cb_mutex); 694 INIT_WORK(&lkb->lkb_cb_work, dlm_callback_work); 695 696 retry: 697 rv = idr_pre_get(&ls->ls_lkbidr, GFP_NOFS); 698 if (!rv) 699 return -ENOMEM; 700 701 spin_lock(&ls->ls_lkbidr_spin); 702 rv = idr_get_new_above(&ls->ls_lkbidr, lkb, 1, &id); 703 if (!rv) 704 lkb->lkb_id = id; 705 spin_unlock(&ls->ls_lkbidr_spin); 706 707 if (rv == -EAGAIN) 708 goto retry; 709 710 if (rv < 0) { 711 log_error(ls, "create_lkb idr error %d", rv); 712 return rv; 713 } 714 715 *lkb_ret = lkb; 716 return 0; 717 } 718 719 static int find_lkb(struct dlm_ls *ls, uint32_t lkid, struct dlm_lkb **lkb_ret) 720 { 721 struct dlm_lkb *lkb; 722 723 spin_lock(&ls->ls_lkbidr_spin); 724 lkb = idr_find(&ls->ls_lkbidr, lkid); 725 if (lkb) 726 kref_get(&lkb->lkb_ref); 727 spin_unlock(&ls->ls_lkbidr_spin); 728 729 *lkb_ret = lkb; 730 return lkb ? 0 : -ENOENT; 731 } 732 733 static void kill_lkb(struct kref *kref) 734 { 735 struct dlm_lkb *lkb = container_of(kref, struct dlm_lkb, lkb_ref); 736 737 /* All work is done after the return from kref_put() so we 738 can release the write_lock before the detach_lkb */ 739 740 DLM_ASSERT(!lkb->lkb_status, dlm_print_lkb(lkb);); 741 } 742 743 /* __put_lkb() is used when an lkb may not have an rsb attached to 744 it so we need to provide the lockspace explicitly */ 745 746 static int __put_lkb(struct dlm_ls *ls, struct dlm_lkb *lkb) 747 { 748 uint32_t lkid = lkb->lkb_id; 749 750 spin_lock(&ls->ls_lkbidr_spin); 751 if (kref_put(&lkb->lkb_ref, kill_lkb)) { 752 idr_remove(&ls->ls_lkbidr, lkid); 753 spin_unlock(&ls->ls_lkbidr_spin); 754 755 detach_lkb(lkb); 756 757 /* for local/process lkbs, lvbptr points to caller's lksb */ 758 if (lkb->lkb_lvbptr && is_master_copy(lkb)) 759 dlm_free_lvb(lkb->lkb_lvbptr); 760 dlm_free_lkb(lkb); 761 return 1; 762 } else { 763 spin_unlock(&ls->ls_lkbidr_spin); 764 return 0; 765 } 766 } 767 768 int dlm_put_lkb(struct dlm_lkb *lkb) 769 { 770 struct dlm_ls *ls; 771 772 DLM_ASSERT(lkb->lkb_resource, dlm_print_lkb(lkb);); 773 DLM_ASSERT(lkb->lkb_resource->res_ls, dlm_print_lkb(lkb);); 774 775 ls = lkb->lkb_resource->res_ls; 776 return __put_lkb(ls, lkb); 777 } 778 779 /* This is only called to add a reference when the code already holds 780 a valid reference to the lkb, so there's no need for locking. */ 781 782 static inline void hold_lkb(struct dlm_lkb *lkb) 783 { 784 kref_get(&lkb->lkb_ref); 785 } 786 787 /* This is called when we need to remove a reference and are certain 788 it's not the last ref. e.g. del_lkb is always called between a 789 find_lkb/put_lkb and is always the inverse of a previous add_lkb. 790 put_lkb would work fine, but would involve unnecessary locking */ 791 792 static inline void unhold_lkb(struct dlm_lkb *lkb) 793 { 794 int rv; 795 rv = kref_put(&lkb->lkb_ref, kill_lkb); 796 DLM_ASSERT(!rv, dlm_print_lkb(lkb);); 797 } 798 799 static void lkb_add_ordered(struct list_head *new, struct list_head *head, 800 int mode) 801 { 802 struct dlm_lkb *lkb = NULL; 803 804 list_for_each_entry(lkb, head, lkb_statequeue) 805 if (lkb->lkb_rqmode < mode) 806 break; 807 808 __list_add(new, lkb->lkb_statequeue.prev, &lkb->lkb_statequeue); 809 } 810 811 /* add/remove lkb to rsb's grant/convert/wait queue */ 812 813 static void add_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb, int status) 814 { 815 kref_get(&lkb->lkb_ref); 816 817 DLM_ASSERT(!lkb->lkb_status, dlm_print_lkb(lkb);); 818 819 lkb->lkb_timestamp = ktime_get(); 820 821 lkb->lkb_status = status; 822 823 switch (status) { 824 case DLM_LKSTS_WAITING: 825 if (lkb->lkb_exflags & DLM_LKF_HEADQUE) 826 list_add(&lkb->lkb_statequeue, &r->res_waitqueue); 827 else 828 list_add_tail(&lkb->lkb_statequeue, &r->res_waitqueue); 829 break; 830 case DLM_LKSTS_GRANTED: 831 /* convention says granted locks kept in order of grmode */ 832 lkb_add_ordered(&lkb->lkb_statequeue, &r->res_grantqueue, 833 lkb->lkb_grmode); 834 break; 835 case DLM_LKSTS_CONVERT: 836 if (lkb->lkb_exflags & DLM_LKF_HEADQUE) 837 list_add(&lkb->lkb_statequeue, &r->res_convertqueue); 838 else 839 list_add_tail(&lkb->lkb_statequeue, 840 &r->res_convertqueue); 841 break; 842 default: 843 DLM_ASSERT(0, dlm_print_lkb(lkb); printk("sts=%d\n", status);); 844 } 845 } 846 847 static void del_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb) 848 { 849 lkb->lkb_status = 0; 850 list_del(&lkb->lkb_statequeue); 851 unhold_lkb(lkb); 852 } 853 854 static void move_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb, int sts) 855 { 856 hold_lkb(lkb); 857 del_lkb(r, lkb); 858 add_lkb(r, lkb, sts); 859 unhold_lkb(lkb); 860 } 861 862 static int msg_reply_type(int mstype) 863 { 864 switch (mstype) { 865 case DLM_MSG_REQUEST: 866 return DLM_MSG_REQUEST_REPLY; 867 case DLM_MSG_CONVERT: 868 return DLM_MSG_CONVERT_REPLY; 869 case DLM_MSG_UNLOCK: 870 return DLM_MSG_UNLOCK_REPLY; 871 case DLM_MSG_CANCEL: 872 return DLM_MSG_CANCEL_REPLY; 873 case DLM_MSG_LOOKUP: 874 return DLM_MSG_LOOKUP_REPLY; 875 } 876 return -1; 877 } 878 879 static int nodeid_warned(int nodeid, int num_nodes, int *warned) 880 { 881 int i; 882 883 for (i = 0; i < num_nodes; i++) { 884 if (!warned[i]) { 885 warned[i] = nodeid; 886 return 0; 887 } 888 if (warned[i] == nodeid) 889 return 1; 890 } 891 return 0; 892 } 893 894 void dlm_scan_waiters(struct dlm_ls *ls) 895 { 896 struct dlm_lkb *lkb; 897 ktime_t zero = ktime_set(0, 0); 898 s64 us; 899 s64 debug_maxus = 0; 900 u32 debug_scanned = 0; 901 u32 debug_expired = 0; 902 int num_nodes = 0; 903 int *warned = NULL; 904 905 if (!dlm_config.ci_waitwarn_us) 906 return; 907 908 mutex_lock(&ls->ls_waiters_mutex); 909 910 list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) { 911 if (ktime_equal(lkb->lkb_wait_time, zero)) 912 continue; 913 914 debug_scanned++; 915 916 us = ktime_to_us(ktime_sub(ktime_get(), lkb->lkb_wait_time)); 917 918 if (us < dlm_config.ci_waitwarn_us) 919 continue; 920 921 lkb->lkb_wait_time = zero; 922 923 debug_expired++; 924 if (us > debug_maxus) 925 debug_maxus = us; 926 927 if (!num_nodes) { 928 num_nodes = ls->ls_num_nodes; 929 warned = kzalloc(num_nodes * sizeof(int), GFP_KERNEL); 930 } 931 if (!warned) 932 continue; 933 if (nodeid_warned(lkb->lkb_wait_nodeid, num_nodes, warned)) 934 continue; 935 936 log_error(ls, "waitwarn %x %lld %d us check connection to " 937 "node %d", lkb->lkb_id, (long long)us, 938 dlm_config.ci_waitwarn_us, lkb->lkb_wait_nodeid); 939 } 940 mutex_unlock(&ls->ls_waiters_mutex); 941 kfree(warned); 942 943 if (debug_expired) 944 log_debug(ls, "scan_waiters %u warn %u over %d us max %lld us", 945 debug_scanned, debug_expired, 946 dlm_config.ci_waitwarn_us, (long long)debug_maxus); 947 } 948 949 /* add/remove lkb from global waiters list of lkb's waiting for 950 a reply from a remote node */ 951 952 static int add_to_waiters(struct dlm_lkb *lkb, int mstype, int to_nodeid) 953 { 954 struct dlm_ls *ls = lkb->lkb_resource->res_ls; 955 int error = 0; 956 957 mutex_lock(&ls->ls_waiters_mutex); 958 959 if (is_overlap_unlock(lkb) || 960 (is_overlap_cancel(lkb) && (mstype == DLM_MSG_CANCEL))) { 961 error = -EINVAL; 962 goto out; 963 } 964 965 if (lkb->lkb_wait_type || is_overlap_cancel(lkb)) { 966 switch (mstype) { 967 case DLM_MSG_UNLOCK: 968 lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK; 969 break; 970 case DLM_MSG_CANCEL: 971 lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL; 972 break; 973 default: 974 error = -EBUSY; 975 goto out; 976 } 977 lkb->lkb_wait_count++; 978 hold_lkb(lkb); 979 980 log_debug(ls, "addwait %x cur %d overlap %d count %d f %x", 981 lkb->lkb_id, lkb->lkb_wait_type, mstype, 982 lkb->lkb_wait_count, lkb->lkb_flags); 983 goto out; 984 } 985 986 DLM_ASSERT(!lkb->lkb_wait_count, 987 dlm_print_lkb(lkb); 988 printk("wait_count %d\n", lkb->lkb_wait_count);); 989 990 lkb->lkb_wait_count++; 991 lkb->lkb_wait_type = mstype; 992 lkb->lkb_wait_time = ktime_get(); 993 lkb->lkb_wait_nodeid = to_nodeid; /* for debugging */ 994 hold_lkb(lkb); 995 list_add(&lkb->lkb_wait_reply, &ls->ls_waiters); 996 out: 997 if (error) 998 log_error(ls, "addwait error %x %d flags %x %d %d %s", 999 lkb->lkb_id, error, lkb->lkb_flags, mstype, 1000 lkb->lkb_wait_type, lkb->lkb_resource->res_name); 1001 mutex_unlock(&ls->ls_waiters_mutex); 1002 return error; 1003 } 1004 1005 /* We clear the RESEND flag because we might be taking an lkb off the waiters 1006 list as part of process_requestqueue (e.g. a lookup that has an optimized 1007 request reply on the requestqueue) between dlm_recover_waiters_pre() which 1008 set RESEND and dlm_recover_waiters_post() */ 1009 1010 static int _remove_from_waiters(struct dlm_lkb *lkb, int mstype, 1011 struct dlm_message *ms) 1012 { 1013 struct dlm_ls *ls = lkb->lkb_resource->res_ls; 1014 int overlap_done = 0; 1015 1016 if (is_overlap_unlock(lkb) && (mstype == DLM_MSG_UNLOCK_REPLY)) { 1017 log_debug(ls, "remwait %x unlock_reply overlap", lkb->lkb_id); 1018 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK; 1019 overlap_done = 1; 1020 goto out_del; 1021 } 1022 1023 if (is_overlap_cancel(lkb) && (mstype == DLM_MSG_CANCEL_REPLY)) { 1024 log_debug(ls, "remwait %x cancel_reply overlap", lkb->lkb_id); 1025 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL; 1026 overlap_done = 1; 1027 goto out_del; 1028 } 1029 1030 /* Cancel state was preemptively cleared by a successful convert, 1031 see next comment, nothing to do. */ 1032 1033 if ((mstype == DLM_MSG_CANCEL_REPLY) && 1034 (lkb->lkb_wait_type != DLM_MSG_CANCEL)) { 1035 log_debug(ls, "remwait %x cancel_reply wait_type %d", 1036 lkb->lkb_id, lkb->lkb_wait_type); 1037 return -1; 1038 } 1039 1040 /* Remove for the convert reply, and premptively remove for the 1041 cancel reply. A convert has been granted while there's still 1042 an outstanding cancel on it (the cancel is moot and the result 1043 in the cancel reply should be 0). We preempt the cancel reply 1044 because the app gets the convert result and then can follow up 1045 with another op, like convert. This subsequent op would see the 1046 lingering state of the cancel and fail with -EBUSY. */ 1047 1048 if ((mstype == DLM_MSG_CONVERT_REPLY) && 1049 (lkb->lkb_wait_type == DLM_MSG_CONVERT) && 1050 is_overlap_cancel(lkb) && ms && !ms->m_result) { 1051 log_debug(ls, "remwait %x convert_reply zap overlap_cancel", 1052 lkb->lkb_id); 1053 lkb->lkb_wait_type = 0; 1054 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL; 1055 lkb->lkb_wait_count--; 1056 goto out_del; 1057 } 1058 1059 /* N.B. type of reply may not always correspond to type of original 1060 msg due to lookup->request optimization, verify others? */ 1061 1062 if (lkb->lkb_wait_type) { 1063 lkb->lkb_wait_type = 0; 1064 goto out_del; 1065 } 1066 1067 log_error(ls, "remwait error %x reply %d flags %x no wait_type", 1068 lkb->lkb_id, mstype, lkb->lkb_flags); 1069 return -1; 1070 1071 out_del: 1072 /* the force-unlock/cancel has completed and we haven't recvd a reply 1073 to the op that was in progress prior to the unlock/cancel; we 1074 give up on any reply to the earlier op. FIXME: not sure when/how 1075 this would happen */ 1076 1077 if (overlap_done && lkb->lkb_wait_type) { 1078 log_error(ls, "remwait error %x reply %d wait_type %d overlap", 1079 lkb->lkb_id, mstype, lkb->lkb_wait_type); 1080 lkb->lkb_wait_count--; 1081 lkb->lkb_wait_type = 0; 1082 } 1083 1084 DLM_ASSERT(lkb->lkb_wait_count, dlm_print_lkb(lkb);); 1085 1086 lkb->lkb_flags &= ~DLM_IFL_RESEND; 1087 lkb->lkb_wait_count--; 1088 if (!lkb->lkb_wait_count) 1089 list_del_init(&lkb->lkb_wait_reply); 1090 unhold_lkb(lkb); 1091 return 0; 1092 } 1093 1094 static int remove_from_waiters(struct dlm_lkb *lkb, int mstype) 1095 { 1096 struct dlm_ls *ls = lkb->lkb_resource->res_ls; 1097 int error; 1098 1099 mutex_lock(&ls->ls_waiters_mutex); 1100 error = _remove_from_waiters(lkb, mstype, NULL); 1101 mutex_unlock(&ls->ls_waiters_mutex); 1102 return error; 1103 } 1104 1105 /* Handles situations where we might be processing a "fake" or "stub" reply in 1106 which we can't try to take waiters_mutex again. */ 1107 1108 static int remove_from_waiters_ms(struct dlm_lkb *lkb, struct dlm_message *ms) 1109 { 1110 struct dlm_ls *ls = lkb->lkb_resource->res_ls; 1111 int error; 1112 1113 if (ms->m_flags != DLM_IFL_STUB_MS) 1114 mutex_lock(&ls->ls_waiters_mutex); 1115 error = _remove_from_waiters(lkb, ms->m_type, ms); 1116 if (ms->m_flags != DLM_IFL_STUB_MS) 1117 mutex_unlock(&ls->ls_waiters_mutex); 1118 return error; 1119 } 1120 1121 static void dir_remove(struct dlm_rsb *r) 1122 { 1123 int to_nodeid; 1124 1125 if (dlm_no_directory(r->res_ls)) 1126 return; 1127 1128 to_nodeid = dlm_dir_nodeid(r); 1129 if (to_nodeid != dlm_our_nodeid()) 1130 send_remove(r); 1131 else 1132 dlm_dir_remove_entry(r->res_ls, to_nodeid, 1133 r->res_name, r->res_length); 1134 } 1135 1136 /* FIXME: make this more efficient */ 1137 1138 static int shrink_bucket(struct dlm_ls *ls, int b) 1139 { 1140 struct rb_node *n; 1141 struct dlm_rsb *r; 1142 int count = 0, found; 1143 1144 for (;;) { 1145 found = 0; 1146 spin_lock(&ls->ls_rsbtbl[b].lock); 1147 for (n = rb_first(&ls->ls_rsbtbl[b].toss); n; n = rb_next(n)) { 1148 r = rb_entry(n, struct dlm_rsb, res_hashnode); 1149 if (!time_after_eq(jiffies, r->res_toss_time + 1150 dlm_config.ci_toss_secs * HZ)) 1151 continue; 1152 found = 1; 1153 break; 1154 } 1155 1156 if (!found) { 1157 spin_unlock(&ls->ls_rsbtbl[b].lock); 1158 break; 1159 } 1160 1161 if (kref_put(&r->res_ref, kill_rsb)) { 1162 rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss); 1163 spin_unlock(&ls->ls_rsbtbl[b].lock); 1164 1165 if (is_master(r)) 1166 dir_remove(r); 1167 dlm_free_rsb(r); 1168 count++; 1169 } else { 1170 spin_unlock(&ls->ls_rsbtbl[b].lock); 1171 log_error(ls, "tossed rsb in use %s", r->res_name); 1172 } 1173 } 1174 1175 return count; 1176 } 1177 1178 void dlm_scan_rsbs(struct dlm_ls *ls) 1179 { 1180 int i; 1181 1182 for (i = 0; i < ls->ls_rsbtbl_size; i++) { 1183 shrink_bucket(ls, i); 1184 if (dlm_locking_stopped(ls)) 1185 break; 1186 cond_resched(); 1187 } 1188 } 1189 1190 static void add_timeout(struct dlm_lkb *lkb) 1191 { 1192 struct dlm_ls *ls = lkb->lkb_resource->res_ls; 1193 1194 if (is_master_copy(lkb)) 1195 return; 1196 1197 if (test_bit(LSFL_TIMEWARN, &ls->ls_flags) && 1198 !(lkb->lkb_exflags & DLM_LKF_NODLCKWT)) { 1199 lkb->lkb_flags |= DLM_IFL_WATCH_TIMEWARN; 1200 goto add_it; 1201 } 1202 if (lkb->lkb_exflags & DLM_LKF_TIMEOUT) 1203 goto add_it; 1204 return; 1205 1206 add_it: 1207 DLM_ASSERT(list_empty(&lkb->lkb_time_list), dlm_print_lkb(lkb);); 1208 mutex_lock(&ls->ls_timeout_mutex); 1209 hold_lkb(lkb); 1210 list_add_tail(&lkb->lkb_time_list, &ls->ls_timeout); 1211 mutex_unlock(&ls->ls_timeout_mutex); 1212 } 1213 1214 static void del_timeout(struct dlm_lkb *lkb) 1215 { 1216 struct dlm_ls *ls = lkb->lkb_resource->res_ls; 1217 1218 mutex_lock(&ls->ls_timeout_mutex); 1219 if (!list_empty(&lkb->lkb_time_list)) { 1220 list_del_init(&lkb->lkb_time_list); 1221 unhold_lkb(lkb); 1222 } 1223 mutex_unlock(&ls->ls_timeout_mutex); 1224 } 1225 1226 /* FIXME: is it safe to look at lkb_exflags, lkb_flags, lkb_timestamp, and 1227 lkb_lksb_timeout without lock_rsb? Note: we can't lock timeout_mutex 1228 and then lock rsb because of lock ordering in add_timeout. We may need 1229 to specify some special timeout-related bits in the lkb that are just to 1230 be accessed under the timeout_mutex. */ 1231 1232 void dlm_scan_timeout(struct dlm_ls *ls) 1233 { 1234 struct dlm_rsb *r; 1235 struct dlm_lkb *lkb; 1236 int do_cancel, do_warn; 1237 s64 wait_us; 1238 1239 for (;;) { 1240 if (dlm_locking_stopped(ls)) 1241 break; 1242 1243 do_cancel = 0; 1244 do_warn = 0; 1245 mutex_lock(&ls->ls_timeout_mutex); 1246 list_for_each_entry(lkb, &ls->ls_timeout, lkb_time_list) { 1247 1248 wait_us = ktime_to_us(ktime_sub(ktime_get(), 1249 lkb->lkb_timestamp)); 1250 1251 if ((lkb->lkb_exflags & DLM_LKF_TIMEOUT) && 1252 wait_us >= (lkb->lkb_timeout_cs * 10000)) 1253 do_cancel = 1; 1254 1255 if ((lkb->lkb_flags & DLM_IFL_WATCH_TIMEWARN) && 1256 wait_us >= dlm_config.ci_timewarn_cs * 10000) 1257 do_warn = 1; 1258 1259 if (!do_cancel && !do_warn) 1260 continue; 1261 hold_lkb(lkb); 1262 break; 1263 } 1264 mutex_unlock(&ls->ls_timeout_mutex); 1265 1266 if (!do_cancel && !do_warn) 1267 break; 1268 1269 r = lkb->lkb_resource; 1270 hold_rsb(r); 1271 lock_rsb(r); 1272 1273 if (do_warn) { 1274 /* clear flag so we only warn once */ 1275 lkb->lkb_flags &= ~DLM_IFL_WATCH_TIMEWARN; 1276 if (!(lkb->lkb_exflags & DLM_LKF_TIMEOUT)) 1277 del_timeout(lkb); 1278 dlm_timeout_warn(lkb); 1279 } 1280 1281 if (do_cancel) { 1282 log_debug(ls, "timeout cancel %x node %d %s", 1283 lkb->lkb_id, lkb->lkb_nodeid, r->res_name); 1284 lkb->lkb_flags &= ~DLM_IFL_WATCH_TIMEWARN; 1285 lkb->lkb_flags |= DLM_IFL_TIMEOUT_CANCEL; 1286 del_timeout(lkb); 1287 _cancel_lock(r, lkb); 1288 } 1289 1290 unlock_rsb(r); 1291 unhold_rsb(r); 1292 dlm_put_lkb(lkb); 1293 } 1294 } 1295 1296 /* This is only called by dlm_recoverd, and we rely on dlm_ls_stop() stopping 1297 dlm_recoverd before checking/setting ls_recover_begin. */ 1298 1299 void dlm_adjust_timeouts(struct dlm_ls *ls) 1300 { 1301 struct dlm_lkb *lkb; 1302 u64 adj_us = jiffies_to_usecs(jiffies - ls->ls_recover_begin); 1303 1304 ls->ls_recover_begin = 0; 1305 mutex_lock(&ls->ls_timeout_mutex); 1306 list_for_each_entry(lkb, &ls->ls_timeout, lkb_time_list) 1307 lkb->lkb_timestamp = ktime_add_us(lkb->lkb_timestamp, adj_us); 1308 mutex_unlock(&ls->ls_timeout_mutex); 1309 1310 if (!dlm_config.ci_waitwarn_us) 1311 return; 1312 1313 mutex_lock(&ls->ls_waiters_mutex); 1314 list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) { 1315 if (ktime_to_us(lkb->lkb_wait_time)) 1316 lkb->lkb_wait_time = ktime_get(); 1317 } 1318 mutex_unlock(&ls->ls_waiters_mutex); 1319 } 1320 1321 /* lkb is master or local copy */ 1322 1323 static void set_lvb_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) 1324 { 1325 int b, len = r->res_ls->ls_lvblen; 1326 1327 /* b=1 lvb returned to caller 1328 b=0 lvb written to rsb or invalidated 1329 b=-1 do nothing */ 1330 1331 b = dlm_lvb_operations[lkb->lkb_grmode + 1][lkb->lkb_rqmode + 1]; 1332 1333 if (b == 1) { 1334 if (!lkb->lkb_lvbptr) 1335 return; 1336 1337 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK)) 1338 return; 1339 1340 if (!r->res_lvbptr) 1341 return; 1342 1343 memcpy(lkb->lkb_lvbptr, r->res_lvbptr, len); 1344 lkb->lkb_lvbseq = r->res_lvbseq; 1345 1346 } else if (b == 0) { 1347 if (lkb->lkb_exflags & DLM_LKF_IVVALBLK) { 1348 rsb_set_flag(r, RSB_VALNOTVALID); 1349 return; 1350 } 1351 1352 if (!lkb->lkb_lvbptr) 1353 return; 1354 1355 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK)) 1356 return; 1357 1358 if (!r->res_lvbptr) 1359 r->res_lvbptr = dlm_allocate_lvb(r->res_ls); 1360 1361 if (!r->res_lvbptr) 1362 return; 1363 1364 memcpy(r->res_lvbptr, lkb->lkb_lvbptr, len); 1365 r->res_lvbseq++; 1366 lkb->lkb_lvbseq = r->res_lvbseq; 1367 rsb_clear_flag(r, RSB_VALNOTVALID); 1368 } 1369 1370 if (rsb_flag(r, RSB_VALNOTVALID)) 1371 lkb->lkb_sbflags |= DLM_SBF_VALNOTVALID; 1372 } 1373 1374 static void set_lvb_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb) 1375 { 1376 if (lkb->lkb_grmode < DLM_LOCK_PW) 1377 return; 1378 1379 if (lkb->lkb_exflags & DLM_LKF_IVVALBLK) { 1380 rsb_set_flag(r, RSB_VALNOTVALID); 1381 return; 1382 } 1383 1384 if (!lkb->lkb_lvbptr) 1385 return; 1386 1387 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK)) 1388 return; 1389 1390 if (!r->res_lvbptr) 1391 r->res_lvbptr = dlm_allocate_lvb(r->res_ls); 1392 1393 if (!r->res_lvbptr) 1394 return; 1395 1396 memcpy(r->res_lvbptr, lkb->lkb_lvbptr, r->res_ls->ls_lvblen); 1397 r->res_lvbseq++; 1398 rsb_clear_flag(r, RSB_VALNOTVALID); 1399 } 1400 1401 /* lkb is process copy (pc) */ 1402 1403 static void set_lvb_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb, 1404 struct dlm_message *ms) 1405 { 1406 int b; 1407 1408 if (!lkb->lkb_lvbptr) 1409 return; 1410 1411 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK)) 1412 return; 1413 1414 b = dlm_lvb_operations[lkb->lkb_grmode + 1][lkb->lkb_rqmode + 1]; 1415 if (b == 1) { 1416 int len = receive_extralen(ms); 1417 if (len > DLM_RESNAME_MAXLEN) 1418 len = DLM_RESNAME_MAXLEN; 1419 memcpy(lkb->lkb_lvbptr, ms->m_extra, len); 1420 lkb->lkb_lvbseq = ms->m_lvbseq; 1421 } 1422 } 1423 1424 /* Manipulate lkb's on rsb's convert/granted/waiting queues 1425 remove_lock -- used for unlock, removes lkb from granted 1426 revert_lock -- used for cancel, moves lkb from convert to granted 1427 grant_lock -- used for request and convert, adds lkb to granted or 1428 moves lkb from convert or waiting to granted 1429 1430 Each of these is used for master or local copy lkb's. There is 1431 also a _pc() variation used to make the corresponding change on 1432 a process copy (pc) lkb. */ 1433 1434 static void _remove_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) 1435 { 1436 del_lkb(r, lkb); 1437 lkb->lkb_grmode = DLM_LOCK_IV; 1438 /* this unhold undoes the original ref from create_lkb() 1439 so this leads to the lkb being freed */ 1440 unhold_lkb(lkb); 1441 } 1442 1443 static void remove_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) 1444 { 1445 set_lvb_unlock(r, lkb); 1446 _remove_lock(r, lkb); 1447 } 1448 1449 static void remove_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb) 1450 { 1451 _remove_lock(r, lkb); 1452 } 1453 1454 /* returns: 0 did nothing 1455 1 moved lock to granted 1456 -1 removed lock */ 1457 1458 static int revert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) 1459 { 1460 int rv = 0; 1461 1462 lkb->lkb_rqmode = DLM_LOCK_IV; 1463 1464 switch (lkb->lkb_status) { 1465 case DLM_LKSTS_GRANTED: 1466 break; 1467 case DLM_LKSTS_CONVERT: 1468 move_lkb(r, lkb, DLM_LKSTS_GRANTED); 1469 rv = 1; 1470 break; 1471 case DLM_LKSTS_WAITING: 1472 del_lkb(r, lkb); 1473 lkb->lkb_grmode = DLM_LOCK_IV; 1474 /* this unhold undoes the original ref from create_lkb() 1475 so this leads to the lkb being freed */ 1476 unhold_lkb(lkb); 1477 rv = -1; 1478 break; 1479 default: 1480 log_print("invalid status for revert %d", lkb->lkb_status); 1481 } 1482 return rv; 1483 } 1484 1485 static int revert_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb) 1486 { 1487 return revert_lock(r, lkb); 1488 } 1489 1490 static void _grant_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) 1491 { 1492 if (lkb->lkb_grmode != lkb->lkb_rqmode) { 1493 lkb->lkb_grmode = lkb->lkb_rqmode; 1494 if (lkb->lkb_status) 1495 move_lkb(r, lkb, DLM_LKSTS_GRANTED); 1496 else 1497 add_lkb(r, lkb, DLM_LKSTS_GRANTED); 1498 } 1499 1500 lkb->lkb_rqmode = DLM_LOCK_IV; 1501 } 1502 1503 static void grant_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) 1504 { 1505 set_lvb_lock(r, lkb); 1506 _grant_lock(r, lkb); 1507 lkb->lkb_highbast = 0; 1508 } 1509 1510 static void grant_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb, 1511 struct dlm_message *ms) 1512 { 1513 set_lvb_lock_pc(r, lkb, ms); 1514 _grant_lock(r, lkb); 1515 } 1516 1517 /* called by grant_pending_locks() which means an async grant message must 1518 be sent to the requesting node in addition to granting the lock if the 1519 lkb belongs to a remote node. */ 1520 1521 static void grant_lock_pending(struct dlm_rsb *r, struct dlm_lkb *lkb) 1522 { 1523 grant_lock(r, lkb); 1524 if (is_master_copy(lkb)) 1525 send_grant(r, lkb); 1526 else 1527 queue_cast(r, lkb, 0); 1528 } 1529 1530 /* The special CONVDEADLK, ALTPR and ALTCW flags allow the master to 1531 change the granted/requested modes. We're munging things accordingly in 1532 the process copy. 1533 CONVDEADLK: our grmode may have been forced down to NL to resolve a 1534 conversion deadlock 1535 ALTPR/ALTCW: our rqmode may have been changed to PR or CW to become 1536 compatible with other granted locks */ 1537 1538 static void munge_demoted(struct dlm_lkb *lkb) 1539 { 1540 if (lkb->lkb_rqmode == DLM_LOCK_IV || lkb->lkb_grmode == DLM_LOCK_IV) { 1541 log_print("munge_demoted %x invalid modes gr %d rq %d", 1542 lkb->lkb_id, lkb->lkb_grmode, lkb->lkb_rqmode); 1543 return; 1544 } 1545 1546 lkb->lkb_grmode = DLM_LOCK_NL; 1547 } 1548 1549 static void munge_altmode(struct dlm_lkb *lkb, struct dlm_message *ms) 1550 { 1551 if (ms->m_type != DLM_MSG_REQUEST_REPLY && 1552 ms->m_type != DLM_MSG_GRANT) { 1553 log_print("munge_altmode %x invalid reply type %d", 1554 lkb->lkb_id, ms->m_type); 1555 return; 1556 } 1557 1558 if (lkb->lkb_exflags & DLM_LKF_ALTPR) 1559 lkb->lkb_rqmode = DLM_LOCK_PR; 1560 else if (lkb->lkb_exflags & DLM_LKF_ALTCW) 1561 lkb->lkb_rqmode = DLM_LOCK_CW; 1562 else { 1563 log_print("munge_altmode invalid exflags %x", lkb->lkb_exflags); 1564 dlm_print_lkb(lkb); 1565 } 1566 } 1567 1568 static inline int first_in_list(struct dlm_lkb *lkb, struct list_head *head) 1569 { 1570 struct dlm_lkb *first = list_entry(head->next, struct dlm_lkb, 1571 lkb_statequeue); 1572 if (lkb->lkb_id == first->lkb_id) 1573 return 1; 1574 1575 return 0; 1576 } 1577 1578 /* Check if the given lkb conflicts with another lkb on the queue. */ 1579 1580 static int queue_conflict(struct list_head *head, struct dlm_lkb *lkb) 1581 { 1582 struct dlm_lkb *this; 1583 1584 list_for_each_entry(this, head, lkb_statequeue) { 1585 if (this == lkb) 1586 continue; 1587 if (!modes_compat(this, lkb)) 1588 return 1; 1589 } 1590 return 0; 1591 } 1592 1593 /* 1594 * "A conversion deadlock arises with a pair of lock requests in the converting 1595 * queue for one resource. The granted mode of each lock blocks the requested 1596 * mode of the other lock." 1597 * 1598 * Part 2: if the granted mode of lkb is preventing an earlier lkb in the 1599 * convert queue from being granted, then deadlk/demote lkb. 1600 * 1601 * Example: 1602 * Granted Queue: empty 1603 * Convert Queue: NL->EX (first lock) 1604 * PR->EX (second lock) 1605 * 1606 * The first lock can't be granted because of the granted mode of the second 1607 * lock and the second lock can't be granted because it's not first in the 1608 * list. We either cancel lkb's conversion (PR->EX) and return EDEADLK, or we 1609 * demote the granted mode of lkb (from PR to NL) if it has the CONVDEADLK 1610 * flag set and return DEMOTED in the lksb flags. 1611 * 1612 * Originally, this function detected conv-deadlk in a more limited scope: 1613 * - if !modes_compat(lkb1, lkb2) && !modes_compat(lkb2, lkb1), or 1614 * - if lkb1 was the first entry in the queue (not just earlier), and was 1615 * blocked by the granted mode of lkb2, and there was nothing on the 1616 * granted queue preventing lkb1 from being granted immediately, i.e. 1617 * lkb2 was the only thing preventing lkb1 from being granted. 1618 * 1619 * That second condition meant we'd only say there was conv-deadlk if 1620 * resolving it (by demotion) would lead to the first lock on the convert 1621 * queue being granted right away. It allowed conversion deadlocks to exist 1622 * between locks on the convert queue while they couldn't be granted anyway. 1623 * 1624 * Now, we detect and take action on conversion deadlocks immediately when 1625 * they're created, even if they may not be immediately consequential. If 1626 * lkb1 exists anywhere in the convert queue and lkb2 comes in with a granted 1627 * mode that would prevent lkb1's conversion from being granted, we do a 1628 * deadlk/demote on lkb2 right away and don't let it onto the convert queue. 1629 * I think this means that the lkb_is_ahead condition below should always 1630 * be zero, i.e. there will never be conv-deadlk between two locks that are 1631 * both already on the convert queue. 1632 */ 1633 1634 static int conversion_deadlock_detect(struct dlm_rsb *r, struct dlm_lkb *lkb2) 1635 { 1636 struct dlm_lkb *lkb1; 1637 int lkb_is_ahead = 0; 1638 1639 list_for_each_entry(lkb1, &r->res_convertqueue, lkb_statequeue) { 1640 if (lkb1 == lkb2) { 1641 lkb_is_ahead = 1; 1642 continue; 1643 } 1644 1645 if (!lkb_is_ahead) { 1646 if (!modes_compat(lkb2, lkb1)) 1647 return 1; 1648 } else { 1649 if (!modes_compat(lkb2, lkb1) && 1650 !modes_compat(lkb1, lkb2)) 1651 return 1; 1652 } 1653 } 1654 return 0; 1655 } 1656 1657 /* 1658 * Return 1 if the lock can be granted, 0 otherwise. 1659 * Also detect and resolve conversion deadlocks. 1660 * 1661 * lkb is the lock to be granted 1662 * 1663 * now is 1 if the function is being called in the context of the 1664 * immediate request, it is 0 if called later, after the lock has been 1665 * queued. 1666 * 1667 * References are from chapter 6 of "VAXcluster Principles" by Roy Davis 1668 */ 1669 1670 static int _can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now) 1671 { 1672 int8_t conv = (lkb->lkb_grmode != DLM_LOCK_IV); 1673 1674 /* 1675 * 6-10: Version 5.4 introduced an option to address the phenomenon of 1676 * a new request for a NL mode lock being blocked. 1677 * 1678 * 6-11: If the optional EXPEDITE flag is used with the new NL mode 1679 * request, then it would be granted. In essence, the use of this flag 1680 * tells the Lock Manager to expedite theis request by not considering 1681 * what may be in the CONVERTING or WAITING queues... As of this 1682 * writing, the EXPEDITE flag can be used only with new requests for NL 1683 * mode locks. This flag is not valid for conversion requests. 1684 * 1685 * A shortcut. Earlier checks return an error if EXPEDITE is used in a 1686 * conversion or used with a non-NL requested mode. We also know an 1687 * EXPEDITE request is always granted immediately, so now must always 1688 * be 1. The full condition to grant an expedite request: (now && 1689 * !conv && lkb->rqmode == DLM_LOCK_NL && (flags & EXPEDITE)) can 1690 * therefore be shortened to just checking the flag. 1691 */ 1692 1693 if (lkb->lkb_exflags & DLM_LKF_EXPEDITE) 1694 return 1; 1695 1696 /* 1697 * A shortcut. Without this, !queue_conflict(grantqueue, lkb) would be 1698 * added to the remaining conditions. 1699 */ 1700 1701 if (queue_conflict(&r->res_grantqueue, lkb)) 1702 goto out; 1703 1704 /* 1705 * 6-3: By default, a conversion request is immediately granted if the 1706 * requested mode is compatible with the modes of all other granted 1707 * locks 1708 */ 1709 1710 if (queue_conflict(&r->res_convertqueue, lkb)) 1711 goto out; 1712 1713 /* 1714 * 6-5: But the default algorithm for deciding whether to grant or 1715 * queue conversion requests does not by itself guarantee that such 1716 * requests are serviced on a "first come first serve" basis. This, in 1717 * turn, can lead to a phenomenon known as "indefinate postponement". 1718 * 1719 * 6-7: This issue is dealt with by using the optional QUECVT flag with 1720 * the system service employed to request a lock conversion. This flag 1721 * forces certain conversion requests to be queued, even if they are 1722 * compatible with the granted modes of other locks on the same 1723 * resource. Thus, the use of this flag results in conversion requests 1724 * being ordered on a "first come first servce" basis. 1725 * 1726 * DCT: This condition is all about new conversions being able to occur 1727 * "in place" while the lock remains on the granted queue (assuming 1728 * nothing else conflicts.) IOW if QUECVT isn't set, a conversion 1729 * doesn't _have_ to go onto the convert queue where it's processed in 1730 * order. The "now" variable is necessary to distinguish converts 1731 * being received and processed for the first time now, because once a 1732 * convert is moved to the conversion queue the condition below applies 1733 * requiring fifo granting. 1734 */ 1735 1736 if (now && conv && !(lkb->lkb_exflags & DLM_LKF_QUECVT)) 1737 return 1; 1738 1739 /* 1740 * The NOORDER flag is set to avoid the standard vms rules on grant 1741 * order. 1742 */ 1743 1744 if (lkb->lkb_exflags & DLM_LKF_NOORDER) 1745 return 1; 1746 1747 /* 1748 * 6-3: Once in that queue [CONVERTING], a conversion request cannot be 1749 * granted until all other conversion requests ahead of it are granted 1750 * and/or canceled. 1751 */ 1752 1753 if (!now && conv && first_in_list(lkb, &r->res_convertqueue)) 1754 return 1; 1755 1756 /* 1757 * 6-4: By default, a new request is immediately granted only if all 1758 * three of the following conditions are satisfied when the request is 1759 * issued: 1760 * - The queue of ungranted conversion requests for the resource is 1761 * empty. 1762 * - The queue of ungranted new requests for the resource is empty. 1763 * - The mode of the new request is compatible with the most 1764 * restrictive mode of all granted locks on the resource. 1765 */ 1766 1767 if (now && !conv && list_empty(&r->res_convertqueue) && 1768 list_empty(&r->res_waitqueue)) 1769 return 1; 1770 1771 /* 1772 * 6-4: Once a lock request is in the queue of ungranted new requests, 1773 * it cannot be granted until the queue of ungranted conversion 1774 * requests is empty, all ungranted new requests ahead of it are 1775 * granted and/or canceled, and it is compatible with the granted mode 1776 * of the most restrictive lock granted on the resource. 1777 */ 1778 1779 if (!now && !conv && list_empty(&r->res_convertqueue) && 1780 first_in_list(lkb, &r->res_waitqueue)) 1781 return 1; 1782 out: 1783 return 0; 1784 } 1785 1786 static int can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now, 1787 int *err) 1788 { 1789 int rv; 1790 int8_t alt = 0, rqmode = lkb->lkb_rqmode; 1791 int8_t is_convert = (lkb->lkb_grmode != DLM_LOCK_IV); 1792 1793 if (err) 1794 *err = 0; 1795 1796 rv = _can_be_granted(r, lkb, now); 1797 if (rv) 1798 goto out; 1799 1800 /* 1801 * The CONVDEADLK flag is non-standard and tells the dlm to resolve 1802 * conversion deadlocks by demoting grmode to NL, otherwise the dlm 1803 * cancels one of the locks. 1804 */ 1805 1806 if (is_convert && can_be_queued(lkb) && 1807 conversion_deadlock_detect(r, lkb)) { 1808 if (lkb->lkb_exflags & DLM_LKF_CONVDEADLK) { 1809 lkb->lkb_grmode = DLM_LOCK_NL; 1810 lkb->lkb_sbflags |= DLM_SBF_DEMOTED; 1811 } else if (!(lkb->lkb_exflags & DLM_LKF_NODLCKWT)) { 1812 if (err) 1813 *err = -EDEADLK; 1814 else { 1815 log_print("can_be_granted deadlock %x now %d", 1816 lkb->lkb_id, now); 1817 dlm_dump_rsb(r); 1818 } 1819 } 1820 goto out; 1821 } 1822 1823 /* 1824 * The ALTPR and ALTCW flags are non-standard and tell the dlm to try 1825 * to grant a request in a mode other than the normal rqmode. It's a 1826 * simple way to provide a big optimization to applications that can 1827 * use them. 1828 */ 1829 1830 if (rqmode != DLM_LOCK_PR && (lkb->lkb_exflags & DLM_LKF_ALTPR)) 1831 alt = DLM_LOCK_PR; 1832 else if (rqmode != DLM_LOCK_CW && (lkb->lkb_exflags & DLM_LKF_ALTCW)) 1833 alt = DLM_LOCK_CW; 1834 1835 if (alt) { 1836 lkb->lkb_rqmode = alt; 1837 rv = _can_be_granted(r, lkb, now); 1838 if (rv) 1839 lkb->lkb_sbflags |= DLM_SBF_ALTMODE; 1840 else 1841 lkb->lkb_rqmode = rqmode; 1842 } 1843 out: 1844 return rv; 1845 } 1846 1847 /* FIXME: I don't think that can_be_granted() can/will demote or find deadlock 1848 for locks pending on the convert list. Once verified (watch for these 1849 log_prints), we should be able to just call _can_be_granted() and not 1850 bother with the demote/deadlk cases here (and there's no easy way to deal 1851 with a deadlk here, we'd have to generate something like grant_lock with 1852 the deadlk error.) */ 1853 1854 /* Returns the highest requested mode of all blocked conversions; sets 1855 cw if there's a blocked conversion to DLM_LOCK_CW. */ 1856 1857 static int grant_pending_convert(struct dlm_rsb *r, int high, int *cw) 1858 { 1859 struct dlm_lkb *lkb, *s; 1860 int hi, demoted, quit, grant_restart, demote_restart; 1861 int deadlk; 1862 1863 quit = 0; 1864 restart: 1865 grant_restart = 0; 1866 demote_restart = 0; 1867 hi = DLM_LOCK_IV; 1868 1869 list_for_each_entry_safe(lkb, s, &r->res_convertqueue, lkb_statequeue) { 1870 demoted = is_demoted(lkb); 1871 deadlk = 0; 1872 1873 if (can_be_granted(r, lkb, 0, &deadlk)) { 1874 grant_lock_pending(r, lkb); 1875 grant_restart = 1; 1876 continue; 1877 } 1878 1879 if (!demoted && is_demoted(lkb)) { 1880 log_print("WARN: pending demoted %x node %d %s", 1881 lkb->lkb_id, lkb->lkb_nodeid, r->res_name); 1882 demote_restart = 1; 1883 continue; 1884 } 1885 1886 if (deadlk) { 1887 log_print("WARN: pending deadlock %x node %d %s", 1888 lkb->lkb_id, lkb->lkb_nodeid, r->res_name); 1889 dlm_dump_rsb(r); 1890 continue; 1891 } 1892 1893 hi = max_t(int, lkb->lkb_rqmode, hi); 1894 1895 if (cw && lkb->lkb_rqmode == DLM_LOCK_CW) 1896 *cw = 1; 1897 } 1898 1899 if (grant_restart) 1900 goto restart; 1901 if (demote_restart && !quit) { 1902 quit = 1; 1903 goto restart; 1904 } 1905 1906 return max_t(int, high, hi); 1907 } 1908 1909 static int grant_pending_wait(struct dlm_rsb *r, int high, int *cw) 1910 { 1911 struct dlm_lkb *lkb, *s; 1912 1913 list_for_each_entry_safe(lkb, s, &r->res_waitqueue, lkb_statequeue) { 1914 if (can_be_granted(r, lkb, 0, NULL)) 1915 grant_lock_pending(r, lkb); 1916 else { 1917 high = max_t(int, lkb->lkb_rqmode, high); 1918 if (lkb->lkb_rqmode == DLM_LOCK_CW) 1919 *cw = 1; 1920 } 1921 } 1922 1923 return high; 1924 } 1925 1926 /* cw of 1 means there's a lock with a rqmode of DLM_LOCK_CW that's blocked 1927 on either the convert or waiting queue. 1928 high is the largest rqmode of all locks blocked on the convert or 1929 waiting queue. */ 1930 1931 static int lock_requires_bast(struct dlm_lkb *gr, int high, int cw) 1932 { 1933 if (gr->lkb_grmode == DLM_LOCK_PR && cw) { 1934 if (gr->lkb_highbast < DLM_LOCK_EX) 1935 return 1; 1936 return 0; 1937 } 1938 1939 if (gr->lkb_highbast < high && 1940 !__dlm_compat_matrix[gr->lkb_grmode+1][high+1]) 1941 return 1; 1942 return 0; 1943 } 1944 1945 static void grant_pending_locks(struct dlm_rsb *r) 1946 { 1947 struct dlm_lkb *lkb, *s; 1948 int high = DLM_LOCK_IV; 1949 int cw = 0; 1950 1951 DLM_ASSERT(is_master(r), dlm_dump_rsb(r);); 1952 1953 high = grant_pending_convert(r, high, &cw); 1954 high = grant_pending_wait(r, high, &cw); 1955 1956 if (high == DLM_LOCK_IV) 1957 return; 1958 1959 /* 1960 * If there are locks left on the wait/convert queue then send blocking 1961 * ASTs to granted locks based on the largest requested mode (high) 1962 * found above. 1963 */ 1964 1965 list_for_each_entry_safe(lkb, s, &r->res_grantqueue, lkb_statequeue) { 1966 if (lkb->lkb_bastfn && lock_requires_bast(lkb, high, cw)) { 1967 if (cw && high == DLM_LOCK_PR && 1968 lkb->lkb_grmode == DLM_LOCK_PR) 1969 queue_bast(r, lkb, DLM_LOCK_CW); 1970 else 1971 queue_bast(r, lkb, high); 1972 lkb->lkb_highbast = high; 1973 } 1974 } 1975 } 1976 1977 static int modes_require_bast(struct dlm_lkb *gr, struct dlm_lkb *rq) 1978 { 1979 if ((gr->lkb_grmode == DLM_LOCK_PR && rq->lkb_rqmode == DLM_LOCK_CW) || 1980 (gr->lkb_grmode == DLM_LOCK_CW && rq->lkb_rqmode == DLM_LOCK_PR)) { 1981 if (gr->lkb_highbast < DLM_LOCK_EX) 1982 return 1; 1983 return 0; 1984 } 1985 1986 if (gr->lkb_highbast < rq->lkb_rqmode && !modes_compat(gr, rq)) 1987 return 1; 1988 return 0; 1989 } 1990 1991 static void send_bast_queue(struct dlm_rsb *r, struct list_head *head, 1992 struct dlm_lkb *lkb) 1993 { 1994 struct dlm_lkb *gr; 1995 1996 list_for_each_entry(gr, head, lkb_statequeue) { 1997 /* skip self when sending basts to convertqueue */ 1998 if (gr == lkb) 1999 continue; 2000 if (gr->lkb_bastfn && modes_require_bast(gr, lkb)) { 2001 queue_bast(r, gr, lkb->lkb_rqmode); 2002 gr->lkb_highbast = lkb->lkb_rqmode; 2003 } 2004 } 2005 } 2006 2007 static void send_blocking_asts(struct dlm_rsb *r, struct dlm_lkb *lkb) 2008 { 2009 send_bast_queue(r, &r->res_grantqueue, lkb); 2010 } 2011 2012 static void send_blocking_asts_all(struct dlm_rsb *r, struct dlm_lkb *lkb) 2013 { 2014 send_bast_queue(r, &r->res_grantqueue, lkb); 2015 send_bast_queue(r, &r->res_convertqueue, lkb); 2016 } 2017 2018 /* set_master(r, lkb) -- set the master nodeid of a resource 2019 2020 The purpose of this function is to set the nodeid field in the given 2021 lkb using the nodeid field in the given rsb. If the rsb's nodeid is 2022 known, it can just be copied to the lkb and the function will return 2023 0. If the rsb's nodeid is _not_ known, it needs to be looked up 2024 before it can be copied to the lkb. 2025 2026 When the rsb nodeid is being looked up remotely, the initial lkb 2027 causing the lookup is kept on the ls_waiters list waiting for the 2028 lookup reply. Other lkb's waiting for the same rsb lookup are kept 2029 on the rsb's res_lookup list until the master is verified. 2030 2031 Return values: 2032 0: nodeid is set in rsb/lkb and the caller should go ahead and use it 2033 1: the rsb master is not available and the lkb has been placed on 2034 a wait queue 2035 */ 2036 2037 static int set_master(struct dlm_rsb *r, struct dlm_lkb *lkb) 2038 { 2039 struct dlm_ls *ls = r->res_ls; 2040 int i, error, dir_nodeid, ret_nodeid, our_nodeid = dlm_our_nodeid(); 2041 2042 if (rsb_flag(r, RSB_MASTER_UNCERTAIN)) { 2043 rsb_clear_flag(r, RSB_MASTER_UNCERTAIN); 2044 r->res_first_lkid = lkb->lkb_id; 2045 lkb->lkb_nodeid = r->res_nodeid; 2046 return 0; 2047 } 2048 2049 if (r->res_first_lkid && r->res_first_lkid != lkb->lkb_id) { 2050 list_add_tail(&lkb->lkb_rsb_lookup, &r->res_lookup); 2051 return 1; 2052 } 2053 2054 if (r->res_nodeid == 0) { 2055 lkb->lkb_nodeid = 0; 2056 return 0; 2057 } 2058 2059 if (r->res_nodeid > 0) { 2060 lkb->lkb_nodeid = r->res_nodeid; 2061 return 0; 2062 } 2063 2064 DLM_ASSERT(r->res_nodeid == -1, dlm_dump_rsb(r);); 2065 2066 dir_nodeid = dlm_dir_nodeid(r); 2067 2068 if (dir_nodeid != our_nodeid) { 2069 r->res_first_lkid = lkb->lkb_id; 2070 send_lookup(r, lkb); 2071 return 1; 2072 } 2073 2074 for (i = 0; i < 2; i++) { 2075 /* It's possible for dlm_scand to remove an old rsb for 2076 this same resource from the toss list, us to create 2077 a new one, look up the master locally, and find it 2078 already exists just before dlm_scand does the 2079 dir_remove() on the previous rsb. */ 2080 2081 error = dlm_dir_lookup(ls, our_nodeid, r->res_name, 2082 r->res_length, &ret_nodeid); 2083 if (!error) 2084 break; 2085 log_debug(ls, "dir_lookup error %d %s", error, r->res_name); 2086 schedule(); 2087 } 2088 if (error && error != -EEXIST) 2089 return error; 2090 2091 if (ret_nodeid == our_nodeid) { 2092 r->res_first_lkid = 0; 2093 r->res_nodeid = 0; 2094 lkb->lkb_nodeid = 0; 2095 } else { 2096 r->res_first_lkid = lkb->lkb_id; 2097 r->res_nodeid = ret_nodeid; 2098 lkb->lkb_nodeid = ret_nodeid; 2099 } 2100 return 0; 2101 } 2102 2103 static void process_lookup_list(struct dlm_rsb *r) 2104 { 2105 struct dlm_lkb *lkb, *safe; 2106 2107 list_for_each_entry_safe(lkb, safe, &r->res_lookup, lkb_rsb_lookup) { 2108 list_del_init(&lkb->lkb_rsb_lookup); 2109 _request_lock(r, lkb); 2110 schedule(); 2111 } 2112 } 2113 2114 /* confirm_master -- confirm (or deny) an rsb's master nodeid */ 2115 2116 static void confirm_master(struct dlm_rsb *r, int error) 2117 { 2118 struct dlm_lkb *lkb; 2119 2120 if (!r->res_first_lkid) 2121 return; 2122 2123 switch (error) { 2124 case 0: 2125 case -EINPROGRESS: 2126 r->res_first_lkid = 0; 2127 process_lookup_list(r); 2128 break; 2129 2130 case -EAGAIN: 2131 case -EBADR: 2132 case -ENOTBLK: 2133 /* the remote request failed and won't be retried (it was 2134 a NOQUEUE, or has been canceled/unlocked); make a waiting 2135 lkb the first_lkid */ 2136 2137 r->res_first_lkid = 0; 2138 2139 if (!list_empty(&r->res_lookup)) { 2140 lkb = list_entry(r->res_lookup.next, struct dlm_lkb, 2141 lkb_rsb_lookup); 2142 list_del_init(&lkb->lkb_rsb_lookup); 2143 r->res_first_lkid = lkb->lkb_id; 2144 _request_lock(r, lkb); 2145 } 2146 break; 2147 2148 default: 2149 log_error(r->res_ls, "confirm_master unknown error %d", error); 2150 } 2151 } 2152 2153 static int set_lock_args(int mode, struct dlm_lksb *lksb, uint32_t flags, 2154 int namelen, unsigned long timeout_cs, 2155 void (*ast) (void *astparam), 2156 void *astparam, 2157 void (*bast) (void *astparam, int mode), 2158 struct dlm_args *args) 2159 { 2160 int rv = -EINVAL; 2161 2162 /* check for invalid arg usage */ 2163 2164 if (mode < 0 || mode > DLM_LOCK_EX) 2165 goto out; 2166 2167 if (!(flags & DLM_LKF_CONVERT) && (namelen > DLM_RESNAME_MAXLEN)) 2168 goto out; 2169 2170 if (flags & DLM_LKF_CANCEL) 2171 goto out; 2172 2173 if (flags & DLM_LKF_QUECVT && !(flags & DLM_LKF_CONVERT)) 2174 goto out; 2175 2176 if (flags & DLM_LKF_CONVDEADLK && !(flags & DLM_LKF_CONVERT)) 2177 goto out; 2178 2179 if (flags & DLM_LKF_CONVDEADLK && flags & DLM_LKF_NOQUEUE) 2180 goto out; 2181 2182 if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_CONVERT) 2183 goto out; 2184 2185 if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_QUECVT) 2186 goto out; 2187 2188 if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_NOQUEUE) 2189 goto out; 2190 2191 if (flags & DLM_LKF_EXPEDITE && mode != DLM_LOCK_NL) 2192 goto out; 2193 2194 if (!ast || !lksb) 2195 goto out; 2196 2197 if (flags & DLM_LKF_VALBLK && !lksb->sb_lvbptr) 2198 goto out; 2199 2200 if (flags & DLM_LKF_CONVERT && !lksb->sb_lkid) 2201 goto out; 2202 2203 /* these args will be copied to the lkb in validate_lock_args, 2204 it cannot be done now because when converting locks, fields in 2205 an active lkb cannot be modified before locking the rsb */ 2206 2207 args->flags = flags; 2208 args->astfn = ast; 2209 args->astparam = astparam; 2210 args->bastfn = bast; 2211 args->timeout = timeout_cs; 2212 args->mode = mode; 2213 args->lksb = lksb; 2214 rv = 0; 2215 out: 2216 return rv; 2217 } 2218 2219 static int set_unlock_args(uint32_t flags, void *astarg, struct dlm_args *args) 2220 { 2221 if (flags & ~(DLM_LKF_CANCEL | DLM_LKF_VALBLK | DLM_LKF_IVVALBLK | 2222 DLM_LKF_FORCEUNLOCK)) 2223 return -EINVAL; 2224 2225 if (flags & DLM_LKF_CANCEL && flags & DLM_LKF_FORCEUNLOCK) 2226 return -EINVAL; 2227 2228 args->flags = flags; 2229 args->astparam = astarg; 2230 return 0; 2231 } 2232 2233 static int validate_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb, 2234 struct dlm_args *args) 2235 { 2236 int rv = -EINVAL; 2237 2238 if (args->flags & DLM_LKF_CONVERT) { 2239 if (lkb->lkb_flags & DLM_IFL_MSTCPY) 2240 goto out; 2241 2242 if (args->flags & DLM_LKF_QUECVT && 2243 !__quecvt_compat_matrix[lkb->lkb_grmode+1][args->mode+1]) 2244 goto out; 2245 2246 rv = -EBUSY; 2247 if (lkb->lkb_status != DLM_LKSTS_GRANTED) 2248 goto out; 2249 2250 if (lkb->lkb_wait_type) 2251 goto out; 2252 2253 if (is_overlap(lkb)) 2254 goto out; 2255 } 2256 2257 lkb->lkb_exflags = args->flags; 2258 lkb->lkb_sbflags = 0; 2259 lkb->lkb_astfn = args->astfn; 2260 lkb->lkb_astparam = args->astparam; 2261 lkb->lkb_bastfn = args->bastfn; 2262 lkb->lkb_rqmode = args->mode; 2263 lkb->lkb_lksb = args->lksb; 2264 lkb->lkb_lvbptr = args->lksb->sb_lvbptr; 2265 lkb->lkb_ownpid = (int) current->pid; 2266 lkb->lkb_timeout_cs = args->timeout; 2267 rv = 0; 2268 out: 2269 if (rv) 2270 log_debug(ls, "validate_lock_args %d %x %x %x %d %d %s", 2271 rv, lkb->lkb_id, lkb->lkb_flags, args->flags, 2272 lkb->lkb_status, lkb->lkb_wait_type, 2273 lkb->lkb_resource->res_name); 2274 return rv; 2275 } 2276 2277 /* when dlm_unlock() sees -EBUSY with CANCEL/FORCEUNLOCK it returns 0 2278 for success */ 2279 2280 /* note: it's valid for lkb_nodeid/res_nodeid to be -1 when we get here 2281 because there may be a lookup in progress and it's valid to do 2282 cancel/unlockf on it */ 2283 2284 static int validate_unlock_args(struct dlm_lkb *lkb, struct dlm_args *args) 2285 { 2286 struct dlm_ls *ls = lkb->lkb_resource->res_ls; 2287 int rv = -EINVAL; 2288 2289 if (lkb->lkb_flags & DLM_IFL_MSTCPY) { 2290 log_error(ls, "unlock on MSTCPY %x", lkb->lkb_id); 2291 dlm_print_lkb(lkb); 2292 goto out; 2293 } 2294 2295 /* an lkb may still exist even though the lock is EOL'ed due to a 2296 cancel, unlock or failed noqueue request; an app can't use these 2297 locks; return same error as if the lkid had not been found at all */ 2298 2299 if (lkb->lkb_flags & DLM_IFL_ENDOFLIFE) { 2300 log_debug(ls, "unlock on ENDOFLIFE %x", lkb->lkb_id); 2301 rv = -ENOENT; 2302 goto out; 2303 } 2304 2305 /* an lkb may be waiting for an rsb lookup to complete where the 2306 lookup was initiated by another lock */ 2307 2308 if (!list_empty(&lkb->lkb_rsb_lookup)) { 2309 if (args->flags & (DLM_LKF_CANCEL | DLM_LKF_FORCEUNLOCK)) { 2310 log_debug(ls, "unlock on rsb_lookup %x", lkb->lkb_id); 2311 list_del_init(&lkb->lkb_rsb_lookup); 2312 queue_cast(lkb->lkb_resource, lkb, 2313 args->flags & DLM_LKF_CANCEL ? 2314 -DLM_ECANCEL : -DLM_EUNLOCK); 2315 unhold_lkb(lkb); /* undoes create_lkb() */ 2316 } 2317 /* caller changes -EBUSY to 0 for CANCEL and FORCEUNLOCK */ 2318 rv = -EBUSY; 2319 goto out; 2320 } 2321 2322 /* cancel not allowed with another cancel/unlock in progress */ 2323 2324 if (args->flags & DLM_LKF_CANCEL) { 2325 if (lkb->lkb_exflags & DLM_LKF_CANCEL) 2326 goto out; 2327 2328 if (is_overlap(lkb)) 2329 goto out; 2330 2331 /* don't let scand try to do a cancel */ 2332 del_timeout(lkb); 2333 2334 if (lkb->lkb_flags & DLM_IFL_RESEND) { 2335 lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL; 2336 rv = -EBUSY; 2337 goto out; 2338 } 2339 2340 /* there's nothing to cancel */ 2341 if (lkb->lkb_status == DLM_LKSTS_GRANTED && 2342 !lkb->lkb_wait_type) { 2343 rv = -EBUSY; 2344 goto out; 2345 } 2346 2347 switch (lkb->lkb_wait_type) { 2348 case DLM_MSG_LOOKUP: 2349 case DLM_MSG_REQUEST: 2350 lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL; 2351 rv = -EBUSY; 2352 goto out; 2353 case DLM_MSG_UNLOCK: 2354 case DLM_MSG_CANCEL: 2355 goto out; 2356 } 2357 /* add_to_waiters() will set OVERLAP_CANCEL */ 2358 goto out_ok; 2359 } 2360 2361 /* do we need to allow a force-unlock if there's a normal unlock 2362 already in progress? in what conditions could the normal unlock 2363 fail such that we'd want to send a force-unlock to be sure? */ 2364 2365 if (args->flags & DLM_LKF_FORCEUNLOCK) { 2366 if (lkb->lkb_exflags & DLM_LKF_FORCEUNLOCK) 2367 goto out; 2368 2369 if (is_overlap_unlock(lkb)) 2370 goto out; 2371 2372 /* don't let scand try to do a cancel */ 2373 del_timeout(lkb); 2374 2375 if (lkb->lkb_flags & DLM_IFL_RESEND) { 2376 lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK; 2377 rv = -EBUSY; 2378 goto out; 2379 } 2380 2381 switch (lkb->lkb_wait_type) { 2382 case DLM_MSG_LOOKUP: 2383 case DLM_MSG_REQUEST: 2384 lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK; 2385 rv = -EBUSY; 2386 goto out; 2387 case DLM_MSG_UNLOCK: 2388 goto out; 2389 } 2390 /* add_to_waiters() will set OVERLAP_UNLOCK */ 2391 goto out_ok; 2392 } 2393 2394 /* normal unlock not allowed if there's any op in progress */ 2395 rv = -EBUSY; 2396 if (lkb->lkb_wait_type || lkb->lkb_wait_count) 2397 goto out; 2398 2399 out_ok: 2400 /* an overlapping op shouldn't blow away exflags from other op */ 2401 lkb->lkb_exflags |= args->flags; 2402 lkb->lkb_sbflags = 0; 2403 lkb->lkb_astparam = args->astparam; 2404 rv = 0; 2405 out: 2406 if (rv) 2407 log_debug(ls, "validate_unlock_args %d %x %x %x %x %d %s", rv, 2408 lkb->lkb_id, lkb->lkb_flags, lkb->lkb_exflags, 2409 args->flags, lkb->lkb_wait_type, 2410 lkb->lkb_resource->res_name); 2411 return rv; 2412 } 2413 2414 /* 2415 * Four stage 4 varieties: 2416 * do_request(), do_convert(), do_unlock(), do_cancel() 2417 * These are called on the master node for the given lock and 2418 * from the central locking logic. 2419 */ 2420 2421 static int do_request(struct dlm_rsb *r, struct dlm_lkb *lkb) 2422 { 2423 int error = 0; 2424 2425 if (can_be_granted(r, lkb, 1, NULL)) { 2426 grant_lock(r, lkb); 2427 queue_cast(r, lkb, 0); 2428 goto out; 2429 } 2430 2431 if (can_be_queued(lkb)) { 2432 error = -EINPROGRESS; 2433 add_lkb(r, lkb, DLM_LKSTS_WAITING); 2434 add_timeout(lkb); 2435 goto out; 2436 } 2437 2438 error = -EAGAIN; 2439 queue_cast(r, lkb, -EAGAIN); 2440 out: 2441 return error; 2442 } 2443 2444 static void do_request_effects(struct dlm_rsb *r, struct dlm_lkb *lkb, 2445 int error) 2446 { 2447 switch (error) { 2448 case -EAGAIN: 2449 if (force_blocking_asts(lkb)) 2450 send_blocking_asts_all(r, lkb); 2451 break; 2452 case -EINPROGRESS: 2453 send_blocking_asts(r, lkb); 2454 break; 2455 } 2456 } 2457 2458 static int do_convert(struct dlm_rsb *r, struct dlm_lkb *lkb) 2459 { 2460 int error = 0; 2461 int deadlk = 0; 2462 2463 /* changing an existing lock may allow others to be granted */ 2464 2465 if (can_be_granted(r, lkb, 1, &deadlk)) { 2466 grant_lock(r, lkb); 2467 queue_cast(r, lkb, 0); 2468 goto out; 2469 } 2470 2471 /* can_be_granted() detected that this lock would block in a conversion 2472 deadlock, so we leave it on the granted queue and return EDEADLK in 2473 the ast for the convert. */ 2474 2475 if (deadlk) { 2476 /* it's left on the granted queue */ 2477 revert_lock(r, lkb); 2478 queue_cast(r, lkb, -EDEADLK); 2479 error = -EDEADLK; 2480 goto out; 2481 } 2482 2483 /* is_demoted() means the can_be_granted() above set the grmode 2484 to NL, and left us on the granted queue. This auto-demotion 2485 (due to CONVDEADLK) might mean other locks, and/or this lock, are 2486 now grantable. We have to try to grant other converting locks 2487 before we try again to grant this one. */ 2488 2489 if (is_demoted(lkb)) { 2490 grant_pending_convert(r, DLM_LOCK_IV, NULL); 2491 if (_can_be_granted(r, lkb, 1)) { 2492 grant_lock(r, lkb); 2493 queue_cast(r, lkb, 0); 2494 goto out; 2495 } 2496 /* else fall through and move to convert queue */ 2497 } 2498 2499 if (can_be_queued(lkb)) { 2500 error = -EINPROGRESS; 2501 del_lkb(r, lkb); 2502 add_lkb(r, lkb, DLM_LKSTS_CONVERT); 2503 add_timeout(lkb); 2504 goto out; 2505 } 2506 2507 error = -EAGAIN; 2508 queue_cast(r, lkb, -EAGAIN); 2509 out: 2510 return error; 2511 } 2512 2513 static void do_convert_effects(struct dlm_rsb *r, struct dlm_lkb *lkb, 2514 int error) 2515 { 2516 switch (error) { 2517 case 0: 2518 grant_pending_locks(r); 2519 /* grant_pending_locks also sends basts */ 2520 break; 2521 case -EAGAIN: 2522 if (force_blocking_asts(lkb)) 2523 send_blocking_asts_all(r, lkb); 2524 break; 2525 case -EINPROGRESS: 2526 send_blocking_asts(r, lkb); 2527 break; 2528 } 2529 } 2530 2531 static int do_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb) 2532 { 2533 remove_lock(r, lkb); 2534 queue_cast(r, lkb, -DLM_EUNLOCK); 2535 return -DLM_EUNLOCK; 2536 } 2537 2538 static void do_unlock_effects(struct dlm_rsb *r, struct dlm_lkb *lkb, 2539 int error) 2540 { 2541 grant_pending_locks(r); 2542 } 2543 2544 /* returns: 0 did nothing, -DLM_ECANCEL canceled lock */ 2545 2546 static int do_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb) 2547 { 2548 int error; 2549 2550 error = revert_lock(r, lkb); 2551 if (error) { 2552 queue_cast(r, lkb, -DLM_ECANCEL); 2553 return -DLM_ECANCEL; 2554 } 2555 return 0; 2556 } 2557 2558 static void do_cancel_effects(struct dlm_rsb *r, struct dlm_lkb *lkb, 2559 int error) 2560 { 2561 if (error) 2562 grant_pending_locks(r); 2563 } 2564 2565 /* 2566 * Four stage 3 varieties: 2567 * _request_lock(), _convert_lock(), _unlock_lock(), _cancel_lock() 2568 */ 2569 2570 /* add a new lkb to a possibly new rsb, called by requesting process */ 2571 2572 static int _request_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) 2573 { 2574 int error; 2575 2576 /* set_master: sets lkb nodeid from r */ 2577 2578 error = set_master(r, lkb); 2579 if (error < 0) 2580 goto out; 2581 if (error) { 2582 error = 0; 2583 goto out; 2584 } 2585 2586 if (is_remote(r)) { 2587 /* receive_request() calls do_request() on remote node */ 2588 error = send_request(r, lkb); 2589 } else { 2590 error = do_request(r, lkb); 2591 /* for remote locks the request_reply is sent 2592 between do_request and do_request_effects */ 2593 do_request_effects(r, lkb, error); 2594 } 2595 out: 2596 return error; 2597 } 2598 2599 /* change some property of an existing lkb, e.g. mode */ 2600 2601 static int _convert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) 2602 { 2603 int error; 2604 2605 if (is_remote(r)) { 2606 /* receive_convert() calls do_convert() on remote node */ 2607 error = send_convert(r, lkb); 2608 } else { 2609 error = do_convert(r, lkb); 2610 /* for remote locks the convert_reply is sent 2611 between do_convert and do_convert_effects */ 2612 do_convert_effects(r, lkb, error); 2613 } 2614 2615 return error; 2616 } 2617 2618 /* remove an existing lkb from the granted queue */ 2619 2620 static int _unlock_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) 2621 { 2622 int error; 2623 2624 if (is_remote(r)) { 2625 /* receive_unlock() calls do_unlock() on remote node */ 2626 error = send_unlock(r, lkb); 2627 } else { 2628 error = do_unlock(r, lkb); 2629 /* for remote locks the unlock_reply is sent 2630 between do_unlock and do_unlock_effects */ 2631 do_unlock_effects(r, lkb, error); 2632 } 2633 2634 return error; 2635 } 2636 2637 /* remove an existing lkb from the convert or wait queue */ 2638 2639 static int _cancel_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) 2640 { 2641 int error; 2642 2643 if (is_remote(r)) { 2644 /* receive_cancel() calls do_cancel() on remote node */ 2645 error = send_cancel(r, lkb); 2646 } else { 2647 error = do_cancel(r, lkb); 2648 /* for remote locks the cancel_reply is sent 2649 between do_cancel and do_cancel_effects */ 2650 do_cancel_effects(r, lkb, error); 2651 } 2652 2653 return error; 2654 } 2655 2656 /* 2657 * Four stage 2 varieties: 2658 * request_lock(), convert_lock(), unlock_lock(), cancel_lock() 2659 */ 2660 2661 static int request_lock(struct dlm_ls *ls, struct dlm_lkb *lkb, char *name, 2662 int len, struct dlm_args *args) 2663 { 2664 struct dlm_rsb *r; 2665 int error; 2666 2667 error = validate_lock_args(ls, lkb, args); 2668 if (error) 2669 goto out; 2670 2671 error = find_rsb(ls, name, len, R_CREATE, &r); 2672 if (error) 2673 goto out; 2674 2675 lock_rsb(r); 2676 2677 attach_lkb(r, lkb); 2678 lkb->lkb_lksb->sb_lkid = lkb->lkb_id; 2679 2680 error = _request_lock(r, lkb); 2681 2682 unlock_rsb(r); 2683 put_rsb(r); 2684 2685 out: 2686 return error; 2687 } 2688 2689 static int convert_lock(struct dlm_ls *ls, struct dlm_lkb *lkb, 2690 struct dlm_args *args) 2691 { 2692 struct dlm_rsb *r; 2693 int error; 2694 2695 r = lkb->lkb_resource; 2696 2697 hold_rsb(r); 2698 lock_rsb(r); 2699 2700 error = validate_lock_args(ls, lkb, args); 2701 if (error) 2702 goto out; 2703 2704 error = _convert_lock(r, lkb); 2705 out: 2706 unlock_rsb(r); 2707 put_rsb(r); 2708 return error; 2709 } 2710 2711 static int unlock_lock(struct dlm_ls *ls, struct dlm_lkb *lkb, 2712 struct dlm_args *args) 2713 { 2714 struct dlm_rsb *r; 2715 int error; 2716 2717 r = lkb->lkb_resource; 2718 2719 hold_rsb(r); 2720 lock_rsb(r); 2721 2722 error = validate_unlock_args(lkb, args); 2723 if (error) 2724 goto out; 2725 2726 error = _unlock_lock(r, lkb); 2727 out: 2728 unlock_rsb(r); 2729 put_rsb(r); 2730 return error; 2731 } 2732 2733 static int cancel_lock(struct dlm_ls *ls, struct dlm_lkb *lkb, 2734 struct dlm_args *args) 2735 { 2736 struct dlm_rsb *r; 2737 int error; 2738 2739 r = lkb->lkb_resource; 2740 2741 hold_rsb(r); 2742 lock_rsb(r); 2743 2744 error = validate_unlock_args(lkb, args); 2745 if (error) 2746 goto out; 2747 2748 error = _cancel_lock(r, lkb); 2749 out: 2750 unlock_rsb(r); 2751 put_rsb(r); 2752 return error; 2753 } 2754 2755 /* 2756 * Two stage 1 varieties: dlm_lock() and dlm_unlock() 2757 */ 2758 2759 int dlm_lock(dlm_lockspace_t *lockspace, 2760 int mode, 2761 struct dlm_lksb *lksb, 2762 uint32_t flags, 2763 void *name, 2764 unsigned int namelen, 2765 uint32_t parent_lkid, 2766 void (*ast) (void *astarg), 2767 void *astarg, 2768 void (*bast) (void *astarg, int mode)) 2769 { 2770 struct dlm_ls *ls; 2771 struct dlm_lkb *lkb; 2772 struct dlm_args args; 2773 int error, convert = flags & DLM_LKF_CONVERT; 2774 2775 ls = dlm_find_lockspace_local(lockspace); 2776 if (!ls) 2777 return -EINVAL; 2778 2779 dlm_lock_recovery(ls); 2780 2781 if (convert) 2782 error = find_lkb(ls, lksb->sb_lkid, &lkb); 2783 else 2784 error = create_lkb(ls, &lkb); 2785 2786 if (error) 2787 goto out; 2788 2789 error = set_lock_args(mode, lksb, flags, namelen, 0, ast, 2790 astarg, bast, &args); 2791 if (error) 2792 goto out_put; 2793 2794 if (convert) 2795 error = convert_lock(ls, lkb, &args); 2796 else 2797 error = request_lock(ls, lkb, name, namelen, &args); 2798 2799 if (error == -EINPROGRESS) 2800 error = 0; 2801 out_put: 2802 if (convert || error) 2803 __put_lkb(ls, lkb); 2804 if (error == -EAGAIN || error == -EDEADLK) 2805 error = 0; 2806 out: 2807 dlm_unlock_recovery(ls); 2808 dlm_put_lockspace(ls); 2809 return error; 2810 } 2811 2812 int dlm_unlock(dlm_lockspace_t *lockspace, 2813 uint32_t lkid, 2814 uint32_t flags, 2815 struct dlm_lksb *lksb, 2816 void *astarg) 2817 { 2818 struct dlm_ls *ls; 2819 struct dlm_lkb *lkb; 2820 struct dlm_args args; 2821 int error; 2822 2823 ls = dlm_find_lockspace_local(lockspace); 2824 if (!ls) 2825 return -EINVAL; 2826 2827 dlm_lock_recovery(ls); 2828 2829 error = find_lkb(ls, lkid, &lkb); 2830 if (error) 2831 goto out; 2832 2833 error = set_unlock_args(flags, astarg, &args); 2834 if (error) 2835 goto out_put; 2836 2837 if (flags & DLM_LKF_CANCEL) 2838 error = cancel_lock(ls, lkb, &args); 2839 else 2840 error = unlock_lock(ls, lkb, &args); 2841 2842 if (error == -DLM_EUNLOCK || error == -DLM_ECANCEL) 2843 error = 0; 2844 if (error == -EBUSY && (flags & (DLM_LKF_CANCEL | DLM_LKF_FORCEUNLOCK))) 2845 error = 0; 2846 out_put: 2847 dlm_put_lkb(lkb); 2848 out: 2849 dlm_unlock_recovery(ls); 2850 dlm_put_lockspace(ls); 2851 return error; 2852 } 2853 2854 /* 2855 * send/receive routines for remote operations and replies 2856 * 2857 * send_args 2858 * send_common 2859 * send_request receive_request 2860 * send_convert receive_convert 2861 * send_unlock receive_unlock 2862 * send_cancel receive_cancel 2863 * send_grant receive_grant 2864 * send_bast receive_bast 2865 * send_lookup receive_lookup 2866 * send_remove receive_remove 2867 * 2868 * send_common_reply 2869 * receive_request_reply send_request_reply 2870 * receive_convert_reply send_convert_reply 2871 * receive_unlock_reply send_unlock_reply 2872 * receive_cancel_reply send_cancel_reply 2873 * receive_lookup_reply send_lookup_reply 2874 */ 2875 2876 static int _create_message(struct dlm_ls *ls, int mb_len, 2877 int to_nodeid, int mstype, 2878 struct dlm_message **ms_ret, 2879 struct dlm_mhandle **mh_ret) 2880 { 2881 struct dlm_message *ms; 2882 struct dlm_mhandle *mh; 2883 char *mb; 2884 2885 /* get_buffer gives us a message handle (mh) that we need to 2886 pass into lowcomms_commit and a message buffer (mb) that we 2887 write our data into */ 2888 2889 mh = dlm_lowcomms_get_buffer(to_nodeid, mb_len, GFP_NOFS, &mb); 2890 if (!mh) 2891 return -ENOBUFS; 2892 2893 memset(mb, 0, mb_len); 2894 2895 ms = (struct dlm_message *) mb; 2896 2897 ms->m_header.h_version = (DLM_HEADER_MAJOR | DLM_HEADER_MINOR); 2898 ms->m_header.h_lockspace = ls->ls_global_id; 2899 ms->m_header.h_nodeid = dlm_our_nodeid(); 2900 ms->m_header.h_length = mb_len; 2901 ms->m_header.h_cmd = DLM_MSG; 2902 2903 ms->m_type = mstype; 2904 2905 *mh_ret = mh; 2906 *ms_ret = ms; 2907 return 0; 2908 } 2909 2910 static int create_message(struct dlm_rsb *r, struct dlm_lkb *lkb, 2911 int to_nodeid, int mstype, 2912 struct dlm_message **ms_ret, 2913 struct dlm_mhandle **mh_ret) 2914 { 2915 int mb_len = sizeof(struct dlm_message); 2916 2917 switch (mstype) { 2918 case DLM_MSG_REQUEST: 2919 case DLM_MSG_LOOKUP: 2920 case DLM_MSG_REMOVE: 2921 mb_len += r->res_length; 2922 break; 2923 case DLM_MSG_CONVERT: 2924 case DLM_MSG_UNLOCK: 2925 case DLM_MSG_REQUEST_REPLY: 2926 case DLM_MSG_CONVERT_REPLY: 2927 case DLM_MSG_GRANT: 2928 if (lkb && lkb->lkb_lvbptr) 2929 mb_len += r->res_ls->ls_lvblen; 2930 break; 2931 } 2932 2933 return _create_message(r->res_ls, mb_len, to_nodeid, mstype, 2934 ms_ret, mh_ret); 2935 } 2936 2937 /* further lowcomms enhancements or alternate implementations may make 2938 the return value from this function useful at some point */ 2939 2940 static int send_message(struct dlm_mhandle *mh, struct dlm_message *ms) 2941 { 2942 dlm_message_out(ms); 2943 dlm_lowcomms_commit_buffer(mh); 2944 return 0; 2945 } 2946 2947 static void send_args(struct dlm_rsb *r, struct dlm_lkb *lkb, 2948 struct dlm_message *ms) 2949 { 2950 ms->m_nodeid = lkb->lkb_nodeid; 2951 ms->m_pid = lkb->lkb_ownpid; 2952 ms->m_lkid = lkb->lkb_id; 2953 ms->m_remid = lkb->lkb_remid; 2954 ms->m_exflags = lkb->lkb_exflags; 2955 ms->m_sbflags = lkb->lkb_sbflags; 2956 ms->m_flags = lkb->lkb_flags; 2957 ms->m_lvbseq = lkb->lkb_lvbseq; 2958 ms->m_status = lkb->lkb_status; 2959 ms->m_grmode = lkb->lkb_grmode; 2960 ms->m_rqmode = lkb->lkb_rqmode; 2961 ms->m_hash = r->res_hash; 2962 2963 /* m_result and m_bastmode are set from function args, 2964 not from lkb fields */ 2965 2966 if (lkb->lkb_bastfn) 2967 ms->m_asts |= DLM_CB_BAST; 2968 if (lkb->lkb_astfn) 2969 ms->m_asts |= DLM_CB_CAST; 2970 2971 /* compare with switch in create_message; send_remove() doesn't 2972 use send_args() */ 2973 2974 switch (ms->m_type) { 2975 case DLM_MSG_REQUEST: 2976 case DLM_MSG_LOOKUP: 2977 memcpy(ms->m_extra, r->res_name, r->res_length); 2978 break; 2979 case DLM_MSG_CONVERT: 2980 case DLM_MSG_UNLOCK: 2981 case DLM_MSG_REQUEST_REPLY: 2982 case DLM_MSG_CONVERT_REPLY: 2983 case DLM_MSG_GRANT: 2984 if (!lkb->lkb_lvbptr) 2985 break; 2986 memcpy(ms->m_extra, lkb->lkb_lvbptr, r->res_ls->ls_lvblen); 2987 break; 2988 } 2989 } 2990 2991 static int send_common(struct dlm_rsb *r, struct dlm_lkb *lkb, int mstype) 2992 { 2993 struct dlm_message *ms; 2994 struct dlm_mhandle *mh; 2995 int to_nodeid, error; 2996 2997 to_nodeid = r->res_nodeid; 2998 2999 error = add_to_waiters(lkb, mstype, to_nodeid); 3000 if (error) 3001 return error; 3002 3003 error = create_message(r, lkb, to_nodeid, mstype, &ms, &mh); 3004 if (error) 3005 goto fail; 3006 3007 send_args(r, lkb, ms); 3008 3009 error = send_message(mh, ms); 3010 if (error) 3011 goto fail; 3012 return 0; 3013 3014 fail: 3015 remove_from_waiters(lkb, msg_reply_type(mstype)); 3016 return error; 3017 } 3018 3019 static int send_request(struct dlm_rsb *r, struct dlm_lkb *lkb) 3020 { 3021 return send_common(r, lkb, DLM_MSG_REQUEST); 3022 } 3023 3024 static int send_convert(struct dlm_rsb *r, struct dlm_lkb *lkb) 3025 { 3026 int error; 3027 3028 error = send_common(r, lkb, DLM_MSG_CONVERT); 3029 3030 /* down conversions go without a reply from the master */ 3031 if (!error && down_conversion(lkb)) { 3032 remove_from_waiters(lkb, DLM_MSG_CONVERT_REPLY); 3033 r->res_ls->ls_stub_ms.m_flags = DLM_IFL_STUB_MS; 3034 r->res_ls->ls_stub_ms.m_type = DLM_MSG_CONVERT_REPLY; 3035 r->res_ls->ls_stub_ms.m_result = 0; 3036 __receive_convert_reply(r, lkb, &r->res_ls->ls_stub_ms); 3037 } 3038 3039 return error; 3040 } 3041 3042 /* FIXME: if this lkb is the only lock we hold on the rsb, then set 3043 MASTER_UNCERTAIN to force the next request on the rsb to confirm 3044 that the master is still correct. */ 3045 3046 static int send_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb) 3047 { 3048 return send_common(r, lkb, DLM_MSG_UNLOCK); 3049 } 3050 3051 static int send_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb) 3052 { 3053 return send_common(r, lkb, DLM_MSG_CANCEL); 3054 } 3055 3056 static int send_grant(struct dlm_rsb *r, struct dlm_lkb *lkb) 3057 { 3058 struct dlm_message *ms; 3059 struct dlm_mhandle *mh; 3060 int to_nodeid, error; 3061 3062 to_nodeid = lkb->lkb_nodeid; 3063 3064 error = create_message(r, lkb, to_nodeid, DLM_MSG_GRANT, &ms, &mh); 3065 if (error) 3066 goto out; 3067 3068 send_args(r, lkb, ms); 3069 3070 ms->m_result = 0; 3071 3072 error = send_message(mh, ms); 3073 out: 3074 return error; 3075 } 3076 3077 static int send_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int mode) 3078 { 3079 struct dlm_message *ms; 3080 struct dlm_mhandle *mh; 3081 int to_nodeid, error; 3082 3083 to_nodeid = lkb->lkb_nodeid; 3084 3085 error = create_message(r, NULL, to_nodeid, DLM_MSG_BAST, &ms, &mh); 3086 if (error) 3087 goto out; 3088 3089 send_args(r, lkb, ms); 3090 3091 ms->m_bastmode = mode; 3092 3093 error = send_message(mh, ms); 3094 out: 3095 return error; 3096 } 3097 3098 static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb) 3099 { 3100 struct dlm_message *ms; 3101 struct dlm_mhandle *mh; 3102 int to_nodeid, error; 3103 3104 to_nodeid = dlm_dir_nodeid(r); 3105 3106 error = add_to_waiters(lkb, DLM_MSG_LOOKUP, to_nodeid); 3107 if (error) 3108 return error; 3109 3110 error = create_message(r, NULL, to_nodeid, DLM_MSG_LOOKUP, &ms, &mh); 3111 if (error) 3112 goto fail; 3113 3114 send_args(r, lkb, ms); 3115 3116 error = send_message(mh, ms); 3117 if (error) 3118 goto fail; 3119 return 0; 3120 3121 fail: 3122 remove_from_waiters(lkb, DLM_MSG_LOOKUP_REPLY); 3123 return error; 3124 } 3125 3126 static int send_remove(struct dlm_rsb *r) 3127 { 3128 struct dlm_message *ms; 3129 struct dlm_mhandle *mh; 3130 int to_nodeid, error; 3131 3132 to_nodeid = dlm_dir_nodeid(r); 3133 3134 error = create_message(r, NULL, to_nodeid, DLM_MSG_REMOVE, &ms, &mh); 3135 if (error) 3136 goto out; 3137 3138 memcpy(ms->m_extra, r->res_name, r->res_length); 3139 ms->m_hash = r->res_hash; 3140 3141 error = send_message(mh, ms); 3142 out: 3143 return error; 3144 } 3145 3146 static int send_common_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, 3147 int mstype, int rv) 3148 { 3149 struct dlm_message *ms; 3150 struct dlm_mhandle *mh; 3151 int to_nodeid, error; 3152 3153 to_nodeid = lkb->lkb_nodeid; 3154 3155 error = create_message(r, lkb, to_nodeid, mstype, &ms, &mh); 3156 if (error) 3157 goto out; 3158 3159 send_args(r, lkb, ms); 3160 3161 ms->m_result = rv; 3162 3163 error = send_message(mh, ms); 3164 out: 3165 return error; 3166 } 3167 3168 static int send_request_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv) 3169 { 3170 return send_common_reply(r, lkb, DLM_MSG_REQUEST_REPLY, rv); 3171 } 3172 3173 static int send_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv) 3174 { 3175 return send_common_reply(r, lkb, DLM_MSG_CONVERT_REPLY, rv); 3176 } 3177 3178 static int send_unlock_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv) 3179 { 3180 return send_common_reply(r, lkb, DLM_MSG_UNLOCK_REPLY, rv); 3181 } 3182 3183 static int send_cancel_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv) 3184 { 3185 return send_common_reply(r, lkb, DLM_MSG_CANCEL_REPLY, rv); 3186 } 3187 3188 static int send_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms_in, 3189 int ret_nodeid, int rv) 3190 { 3191 struct dlm_rsb *r = &ls->ls_stub_rsb; 3192 struct dlm_message *ms; 3193 struct dlm_mhandle *mh; 3194 int error, nodeid = ms_in->m_header.h_nodeid; 3195 3196 error = create_message(r, NULL, nodeid, DLM_MSG_LOOKUP_REPLY, &ms, &mh); 3197 if (error) 3198 goto out; 3199 3200 ms->m_lkid = ms_in->m_lkid; 3201 ms->m_result = rv; 3202 ms->m_nodeid = ret_nodeid; 3203 3204 error = send_message(mh, ms); 3205 out: 3206 return error; 3207 } 3208 3209 /* which args we save from a received message depends heavily on the type 3210 of message, unlike the send side where we can safely send everything about 3211 the lkb for any type of message */ 3212 3213 static void receive_flags(struct dlm_lkb *lkb, struct dlm_message *ms) 3214 { 3215 lkb->lkb_exflags = ms->m_exflags; 3216 lkb->lkb_sbflags = ms->m_sbflags; 3217 lkb->lkb_flags = (lkb->lkb_flags & 0xFFFF0000) | 3218 (ms->m_flags & 0x0000FFFF); 3219 } 3220 3221 static void receive_flags_reply(struct dlm_lkb *lkb, struct dlm_message *ms) 3222 { 3223 if (ms->m_flags == DLM_IFL_STUB_MS) 3224 return; 3225 3226 lkb->lkb_sbflags = ms->m_sbflags; 3227 lkb->lkb_flags = (lkb->lkb_flags & 0xFFFF0000) | 3228 (ms->m_flags & 0x0000FFFF); 3229 } 3230 3231 static int receive_extralen(struct dlm_message *ms) 3232 { 3233 return (ms->m_header.h_length - sizeof(struct dlm_message)); 3234 } 3235 3236 static int receive_lvb(struct dlm_ls *ls, struct dlm_lkb *lkb, 3237 struct dlm_message *ms) 3238 { 3239 int len; 3240 3241 if (lkb->lkb_exflags & DLM_LKF_VALBLK) { 3242 if (!lkb->lkb_lvbptr) 3243 lkb->lkb_lvbptr = dlm_allocate_lvb(ls); 3244 if (!lkb->lkb_lvbptr) 3245 return -ENOMEM; 3246 len = receive_extralen(ms); 3247 if (len > DLM_RESNAME_MAXLEN) 3248 len = DLM_RESNAME_MAXLEN; 3249 memcpy(lkb->lkb_lvbptr, ms->m_extra, len); 3250 } 3251 return 0; 3252 } 3253 3254 static void fake_bastfn(void *astparam, int mode) 3255 { 3256 log_print("fake_bastfn should not be called"); 3257 } 3258 3259 static void fake_astfn(void *astparam) 3260 { 3261 log_print("fake_astfn should not be called"); 3262 } 3263 3264 static int receive_request_args(struct dlm_ls *ls, struct dlm_lkb *lkb, 3265 struct dlm_message *ms) 3266 { 3267 lkb->lkb_nodeid = ms->m_header.h_nodeid; 3268 lkb->lkb_ownpid = ms->m_pid; 3269 lkb->lkb_remid = ms->m_lkid; 3270 lkb->lkb_grmode = DLM_LOCK_IV; 3271 lkb->lkb_rqmode = ms->m_rqmode; 3272 3273 lkb->lkb_bastfn = (ms->m_asts & DLM_CB_BAST) ? &fake_bastfn : NULL; 3274 lkb->lkb_astfn = (ms->m_asts & DLM_CB_CAST) ? &fake_astfn : NULL; 3275 3276 if (lkb->lkb_exflags & DLM_LKF_VALBLK) { 3277 /* lkb was just created so there won't be an lvb yet */ 3278 lkb->lkb_lvbptr = dlm_allocate_lvb(ls); 3279 if (!lkb->lkb_lvbptr) 3280 return -ENOMEM; 3281 } 3282 3283 return 0; 3284 } 3285 3286 static int receive_convert_args(struct dlm_ls *ls, struct dlm_lkb *lkb, 3287 struct dlm_message *ms) 3288 { 3289 if (lkb->lkb_status != DLM_LKSTS_GRANTED) 3290 return -EBUSY; 3291 3292 if (receive_lvb(ls, lkb, ms)) 3293 return -ENOMEM; 3294 3295 lkb->lkb_rqmode = ms->m_rqmode; 3296 lkb->lkb_lvbseq = ms->m_lvbseq; 3297 3298 return 0; 3299 } 3300 3301 static int receive_unlock_args(struct dlm_ls *ls, struct dlm_lkb *lkb, 3302 struct dlm_message *ms) 3303 { 3304 if (receive_lvb(ls, lkb, ms)) 3305 return -ENOMEM; 3306 return 0; 3307 } 3308 3309 /* We fill in the stub-lkb fields with the info that send_xxxx_reply() 3310 uses to send a reply and that the remote end uses to process the reply. */ 3311 3312 static void setup_stub_lkb(struct dlm_ls *ls, struct dlm_message *ms) 3313 { 3314 struct dlm_lkb *lkb = &ls->ls_stub_lkb; 3315 lkb->lkb_nodeid = ms->m_header.h_nodeid; 3316 lkb->lkb_remid = ms->m_lkid; 3317 } 3318 3319 /* This is called after the rsb is locked so that we can safely inspect 3320 fields in the lkb. */ 3321 3322 static int validate_message(struct dlm_lkb *lkb, struct dlm_message *ms) 3323 { 3324 int from = ms->m_header.h_nodeid; 3325 int error = 0; 3326 3327 switch (ms->m_type) { 3328 case DLM_MSG_CONVERT: 3329 case DLM_MSG_UNLOCK: 3330 case DLM_MSG_CANCEL: 3331 if (!is_master_copy(lkb) || lkb->lkb_nodeid != from) 3332 error = -EINVAL; 3333 break; 3334 3335 case DLM_MSG_CONVERT_REPLY: 3336 case DLM_MSG_UNLOCK_REPLY: 3337 case DLM_MSG_CANCEL_REPLY: 3338 case DLM_MSG_GRANT: 3339 case DLM_MSG_BAST: 3340 if (!is_process_copy(lkb) || lkb->lkb_nodeid != from) 3341 error = -EINVAL; 3342 break; 3343 3344 case DLM_MSG_REQUEST_REPLY: 3345 if (!is_process_copy(lkb)) 3346 error = -EINVAL; 3347 else if (lkb->lkb_nodeid != -1 && lkb->lkb_nodeid != from) 3348 error = -EINVAL; 3349 break; 3350 3351 default: 3352 error = -EINVAL; 3353 } 3354 3355 if (error) 3356 log_error(lkb->lkb_resource->res_ls, 3357 "ignore invalid message %d from %d %x %x %x %d", 3358 ms->m_type, from, lkb->lkb_id, lkb->lkb_remid, 3359 lkb->lkb_flags, lkb->lkb_nodeid); 3360 return error; 3361 } 3362 3363 static void receive_request(struct dlm_ls *ls, struct dlm_message *ms) 3364 { 3365 struct dlm_lkb *lkb; 3366 struct dlm_rsb *r; 3367 int error, namelen; 3368 3369 error = create_lkb(ls, &lkb); 3370 if (error) 3371 goto fail; 3372 3373 receive_flags(lkb, ms); 3374 lkb->lkb_flags |= DLM_IFL_MSTCPY; 3375 error = receive_request_args(ls, lkb, ms); 3376 if (error) { 3377 __put_lkb(ls, lkb); 3378 goto fail; 3379 } 3380 3381 namelen = receive_extralen(ms); 3382 3383 error = find_rsb(ls, ms->m_extra, namelen, R_MASTER, &r); 3384 if (error) { 3385 __put_lkb(ls, lkb); 3386 goto fail; 3387 } 3388 3389 lock_rsb(r); 3390 3391 attach_lkb(r, lkb); 3392 error = do_request(r, lkb); 3393 send_request_reply(r, lkb, error); 3394 do_request_effects(r, lkb, error); 3395 3396 unlock_rsb(r); 3397 put_rsb(r); 3398 3399 if (error == -EINPROGRESS) 3400 error = 0; 3401 if (error) 3402 dlm_put_lkb(lkb); 3403 return; 3404 3405 fail: 3406 setup_stub_lkb(ls, ms); 3407 send_request_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error); 3408 } 3409 3410 static void receive_convert(struct dlm_ls *ls, struct dlm_message *ms) 3411 { 3412 struct dlm_lkb *lkb; 3413 struct dlm_rsb *r; 3414 int error, reply = 1; 3415 3416 error = find_lkb(ls, ms->m_remid, &lkb); 3417 if (error) 3418 goto fail; 3419 3420 r = lkb->lkb_resource; 3421 3422 hold_rsb(r); 3423 lock_rsb(r); 3424 3425 error = validate_message(lkb, ms); 3426 if (error) 3427 goto out; 3428 3429 receive_flags(lkb, ms); 3430 3431 error = receive_convert_args(ls, lkb, ms); 3432 if (error) { 3433 send_convert_reply(r, lkb, error); 3434 goto out; 3435 } 3436 3437 reply = !down_conversion(lkb); 3438 3439 error = do_convert(r, lkb); 3440 if (reply) 3441 send_convert_reply(r, lkb, error); 3442 do_convert_effects(r, lkb, error); 3443 out: 3444 unlock_rsb(r); 3445 put_rsb(r); 3446 dlm_put_lkb(lkb); 3447 return; 3448 3449 fail: 3450 setup_stub_lkb(ls, ms); 3451 send_convert_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error); 3452 } 3453 3454 static void receive_unlock(struct dlm_ls *ls, struct dlm_message *ms) 3455 { 3456 struct dlm_lkb *lkb; 3457 struct dlm_rsb *r; 3458 int error; 3459 3460 error = find_lkb(ls, ms->m_remid, &lkb); 3461 if (error) 3462 goto fail; 3463 3464 r = lkb->lkb_resource; 3465 3466 hold_rsb(r); 3467 lock_rsb(r); 3468 3469 error = validate_message(lkb, ms); 3470 if (error) 3471 goto out; 3472 3473 receive_flags(lkb, ms); 3474 3475 error = receive_unlock_args(ls, lkb, ms); 3476 if (error) { 3477 send_unlock_reply(r, lkb, error); 3478 goto out; 3479 } 3480 3481 error = do_unlock(r, lkb); 3482 send_unlock_reply(r, lkb, error); 3483 do_unlock_effects(r, lkb, error); 3484 out: 3485 unlock_rsb(r); 3486 put_rsb(r); 3487 dlm_put_lkb(lkb); 3488 return; 3489 3490 fail: 3491 setup_stub_lkb(ls, ms); 3492 send_unlock_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error); 3493 } 3494 3495 static void receive_cancel(struct dlm_ls *ls, struct dlm_message *ms) 3496 { 3497 struct dlm_lkb *lkb; 3498 struct dlm_rsb *r; 3499 int error; 3500 3501 error = find_lkb(ls, ms->m_remid, &lkb); 3502 if (error) 3503 goto fail; 3504 3505 receive_flags(lkb, ms); 3506 3507 r = lkb->lkb_resource; 3508 3509 hold_rsb(r); 3510 lock_rsb(r); 3511 3512 error = validate_message(lkb, ms); 3513 if (error) 3514 goto out; 3515 3516 error = do_cancel(r, lkb); 3517 send_cancel_reply(r, lkb, error); 3518 do_cancel_effects(r, lkb, error); 3519 out: 3520 unlock_rsb(r); 3521 put_rsb(r); 3522 dlm_put_lkb(lkb); 3523 return; 3524 3525 fail: 3526 setup_stub_lkb(ls, ms); 3527 send_cancel_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error); 3528 } 3529 3530 static void receive_grant(struct dlm_ls *ls, struct dlm_message *ms) 3531 { 3532 struct dlm_lkb *lkb; 3533 struct dlm_rsb *r; 3534 int error; 3535 3536 error = find_lkb(ls, ms->m_remid, &lkb); 3537 if (error) { 3538 log_debug(ls, "receive_grant from %d no lkb %x", 3539 ms->m_header.h_nodeid, ms->m_remid); 3540 return; 3541 } 3542 3543 r = lkb->lkb_resource; 3544 3545 hold_rsb(r); 3546 lock_rsb(r); 3547 3548 error = validate_message(lkb, ms); 3549 if (error) 3550 goto out; 3551 3552 receive_flags_reply(lkb, ms); 3553 if (is_altmode(lkb)) 3554 munge_altmode(lkb, ms); 3555 grant_lock_pc(r, lkb, ms); 3556 queue_cast(r, lkb, 0); 3557 out: 3558 unlock_rsb(r); 3559 put_rsb(r); 3560 dlm_put_lkb(lkb); 3561 } 3562 3563 static void receive_bast(struct dlm_ls *ls, struct dlm_message *ms) 3564 { 3565 struct dlm_lkb *lkb; 3566 struct dlm_rsb *r; 3567 int error; 3568 3569 error = find_lkb(ls, ms->m_remid, &lkb); 3570 if (error) { 3571 log_debug(ls, "receive_bast from %d no lkb %x", 3572 ms->m_header.h_nodeid, ms->m_remid); 3573 return; 3574 } 3575 3576 r = lkb->lkb_resource; 3577 3578 hold_rsb(r); 3579 lock_rsb(r); 3580 3581 error = validate_message(lkb, ms); 3582 if (error) 3583 goto out; 3584 3585 queue_bast(r, lkb, ms->m_bastmode); 3586 out: 3587 unlock_rsb(r); 3588 put_rsb(r); 3589 dlm_put_lkb(lkb); 3590 } 3591 3592 static void receive_lookup(struct dlm_ls *ls, struct dlm_message *ms) 3593 { 3594 int len, error, ret_nodeid, dir_nodeid, from_nodeid, our_nodeid; 3595 3596 from_nodeid = ms->m_header.h_nodeid; 3597 our_nodeid = dlm_our_nodeid(); 3598 3599 len = receive_extralen(ms); 3600 3601 dir_nodeid = dlm_hash2nodeid(ls, ms->m_hash); 3602 if (dir_nodeid != our_nodeid) { 3603 log_error(ls, "lookup dir_nodeid %d from %d", 3604 dir_nodeid, from_nodeid); 3605 error = -EINVAL; 3606 ret_nodeid = -1; 3607 goto out; 3608 } 3609 3610 error = dlm_dir_lookup(ls, from_nodeid, ms->m_extra, len, &ret_nodeid); 3611 3612 /* Optimization: we're master so treat lookup as a request */ 3613 if (!error && ret_nodeid == our_nodeid) { 3614 receive_request(ls, ms); 3615 return; 3616 } 3617 out: 3618 send_lookup_reply(ls, ms, ret_nodeid, error); 3619 } 3620 3621 static void receive_remove(struct dlm_ls *ls, struct dlm_message *ms) 3622 { 3623 int len, dir_nodeid, from_nodeid; 3624 3625 from_nodeid = ms->m_header.h_nodeid; 3626 3627 len = receive_extralen(ms); 3628 3629 dir_nodeid = dlm_hash2nodeid(ls, ms->m_hash); 3630 if (dir_nodeid != dlm_our_nodeid()) { 3631 log_error(ls, "remove dir entry dir_nodeid %d from %d", 3632 dir_nodeid, from_nodeid); 3633 return; 3634 } 3635 3636 dlm_dir_remove_entry(ls, from_nodeid, ms->m_extra, len); 3637 } 3638 3639 static void receive_purge(struct dlm_ls *ls, struct dlm_message *ms) 3640 { 3641 do_purge(ls, ms->m_nodeid, ms->m_pid); 3642 } 3643 3644 static void receive_request_reply(struct dlm_ls *ls, struct dlm_message *ms) 3645 { 3646 struct dlm_lkb *lkb; 3647 struct dlm_rsb *r; 3648 int error, mstype, result; 3649 3650 error = find_lkb(ls, ms->m_remid, &lkb); 3651 if (error) { 3652 log_debug(ls, "receive_request_reply from %d no lkb %x", 3653 ms->m_header.h_nodeid, ms->m_remid); 3654 return; 3655 } 3656 3657 r = lkb->lkb_resource; 3658 hold_rsb(r); 3659 lock_rsb(r); 3660 3661 error = validate_message(lkb, ms); 3662 if (error) 3663 goto out; 3664 3665 mstype = lkb->lkb_wait_type; 3666 error = remove_from_waiters(lkb, DLM_MSG_REQUEST_REPLY); 3667 if (error) 3668 goto out; 3669 3670 /* Optimization: the dir node was also the master, so it took our 3671 lookup as a request and sent request reply instead of lookup reply */ 3672 if (mstype == DLM_MSG_LOOKUP) { 3673 r->res_nodeid = ms->m_header.h_nodeid; 3674 lkb->lkb_nodeid = r->res_nodeid; 3675 } 3676 3677 /* this is the value returned from do_request() on the master */ 3678 result = ms->m_result; 3679 3680 switch (result) { 3681 case -EAGAIN: 3682 /* request would block (be queued) on remote master */ 3683 queue_cast(r, lkb, -EAGAIN); 3684 confirm_master(r, -EAGAIN); 3685 unhold_lkb(lkb); /* undoes create_lkb() */ 3686 break; 3687 3688 case -EINPROGRESS: 3689 case 0: 3690 /* request was queued or granted on remote master */ 3691 receive_flags_reply(lkb, ms); 3692 lkb->lkb_remid = ms->m_lkid; 3693 if (is_altmode(lkb)) 3694 munge_altmode(lkb, ms); 3695 if (result) { 3696 add_lkb(r, lkb, DLM_LKSTS_WAITING); 3697 add_timeout(lkb); 3698 } else { 3699 grant_lock_pc(r, lkb, ms); 3700 queue_cast(r, lkb, 0); 3701 } 3702 confirm_master(r, result); 3703 break; 3704 3705 case -EBADR: 3706 case -ENOTBLK: 3707 /* find_rsb failed to find rsb or rsb wasn't master */ 3708 log_debug(ls, "receive_request_reply %x %x master diff %d %d", 3709 lkb->lkb_id, lkb->lkb_flags, r->res_nodeid, result); 3710 r->res_nodeid = -1; 3711 lkb->lkb_nodeid = -1; 3712 3713 if (is_overlap(lkb)) { 3714 /* we'll ignore error in cancel/unlock reply */ 3715 queue_cast_overlap(r, lkb); 3716 confirm_master(r, result); 3717 unhold_lkb(lkb); /* undoes create_lkb() */ 3718 } else 3719 _request_lock(r, lkb); 3720 break; 3721 3722 default: 3723 log_error(ls, "receive_request_reply %x error %d", 3724 lkb->lkb_id, result); 3725 } 3726 3727 if (is_overlap_unlock(lkb) && (result == 0 || result == -EINPROGRESS)) { 3728 log_debug(ls, "receive_request_reply %x result %d unlock", 3729 lkb->lkb_id, result); 3730 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK; 3731 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL; 3732 send_unlock(r, lkb); 3733 } else if (is_overlap_cancel(lkb) && (result == -EINPROGRESS)) { 3734 log_debug(ls, "receive_request_reply %x cancel", lkb->lkb_id); 3735 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK; 3736 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL; 3737 send_cancel(r, lkb); 3738 } else { 3739 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL; 3740 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK; 3741 } 3742 out: 3743 unlock_rsb(r); 3744 put_rsb(r); 3745 dlm_put_lkb(lkb); 3746 } 3747 3748 static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, 3749 struct dlm_message *ms) 3750 { 3751 /* this is the value returned from do_convert() on the master */ 3752 switch (ms->m_result) { 3753 case -EAGAIN: 3754 /* convert would block (be queued) on remote master */ 3755 queue_cast(r, lkb, -EAGAIN); 3756 break; 3757 3758 case -EDEADLK: 3759 receive_flags_reply(lkb, ms); 3760 revert_lock_pc(r, lkb); 3761 queue_cast(r, lkb, -EDEADLK); 3762 break; 3763 3764 case -EINPROGRESS: 3765 /* convert was queued on remote master */ 3766 receive_flags_reply(lkb, ms); 3767 if (is_demoted(lkb)) 3768 munge_demoted(lkb); 3769 del_lkb(r, lkb); 3770 add_lkb(r, lkb, DLM_LKSTS_CONVERT); 3771 add_timeout(lkb); 3772 break; 3773 3774 case 0: 3775 /* convert was granted on remote master */ 3776 receive_flags_reply(lkb, ms); 3777 if (is_demoted(lkb)) 3778 munge_demoted(lkb); 3779 grant_lock_pc(r, lkb, ms); 3780 queue_cast(r, lkb, 0); 3781 break; 3782 3783 default: 3784 log_error(r->res_ls, "receive_convert_reply %x error %d", 3785 lkb->lkb_id, ms->m_result); 3786 } 3787 } 3788 3789 static void _receive_convert_reply(struct dlm_lkb *lkb, struct dlm_message *ms) 3790 { 3791 struct dlm_rsb *r = lkb->lkb_resource; 3792 int error; 3793 3794 hold_rsb(r); 3795 lock_rsb(r); 3796 3797 error = validate_message(lkb, ms); 3798 if (error) 3799 goto out; 3800 3801 /* stub reply can happen with waiters_mutex held */ 3802 error = remove_from_waiters_ms(lkb, ms); 3803 if (error) 3804 goto out; 3805 3806 __receive_convert_reply(r, lkb, ms); 3807 out: 3808 unlock_rsb(r); 3809 put_rsb(r); 3810 } 3811 3812 static void receive_convert_reply(struct dlm_ls *ls, struct dlm_message *ms) 3813 { 3814 struct dlm_lkb *lkb; 3815 int error; 3816 3817 error = find_lkb(ls, ms->m_remid, &lkb); 3818 if (error) { 3819 log_debug(ls, "receive_convert_reply from %d no lkb %x", 3820 ms->m_header.h_nodeid, ms->m_remid); 3821 return; 3822 } 3823 3824 _receive_convert_reply(lkb, ms); 3825 dlm_put_lkb(lkb); 3826 } 3827 3828 static void _receive_unlock_reply(struct dlm_lkb *lkb, struct dlm_message *ms) 3829 { 3830 struct dlm_rsb *r = lkb->lkb_resource; 3831 int error; 3832 3833 hold_rsb(r); 3834 lock_rsb(r); 3835 3836 error = validate_message(lkb, ms); 3837 if (error) 3838 goto out; 3839 3840 /* stub reply can happen with waiters_mutex held */ 3841 error = remove_from_waiters_ms(lkb, ms); 3842 if (error) 3843 goto out; 3844 3845 /* this is the value returned from do_unlock() on the master */ 3846 3847 switch (ms->m_result) { 3848 case -DLM_EUNLOCK: 3849 receive_flags_reply(lkb, ms); 3850 remove_lock_pc(r, lkb); 3851 queue_cast(r, lkb, -DLM_EUNLOCK); 3852 break; 3853 case -ENOENT: 3854 break; 3855 default: 3856 log_error(r->res_ls, "receive_unlock_reply %x error %d", 3857 lkb->lkb_id, ms->m_result); 3858 } 3859 out: 3860 unlock_rsb(r); 3861 put_rsb(r); 3862 } 3863 3864 static void receive_unlock_reply(struct dlm_ls *ls, struct dlm_message *ms) 3865 { 3866 struct dlm_lkb *lkb; 3867 int error; 3868 3869 error = find_lkb(ls, ms->m_remid, &lkb); 3870 if (error) { 3871 log_debug(ls, "receive_unlock_reply from %d no lkb %x", 3872 ms->m_header.h_nodeid, ms->m_remid); 3873 return; 3874 } 3875 3876 _receive_unlock_reply(lkb, ms); 3877 dlm_put_lkb(lkb); 3878 } 3879 3880 static void _receive_cancel_reply(struct dlm_lkb *lkb, struct dlm_message *ms) 3881 { 3882 struct dlm_rsb *r = lkb->lkb_resource; 3883 int error; 3884 3885 hold_rsb(r); 3886 lock_rsb(r); 3887 3888 error = validate_message(lkb, ms); 3889 if (error) 3890 goto out; 3891 3892 /* stub reply can happen with waiters_mutex held */ 3893 error = remove_from_waiters_ms(lkb, ms); 3894 if (error) 3895 goto out; 3896 3897 /* this is the value returned from do_cancel() on the master */ 3898 3899 switch (ms->m_result) { 3900 case -DLM_ECANCEL: 3901 receive_flags_reply(lkb, ms); 3902 revert_lock_pc(r, lkb); 3903 queue_cast(r, lkb, -DLM_ECANCEL); 3904 break; 3905 case 0: 3906 break; 3907 default: 3908 log_error(r->res_ls, "receive_cancel_reply %x error %d", 3909 lkb->lkb_id, ms->m_result); 3910 } 3911 out: 3912 unlock_rsb(r); 3913 put_rsb(r); 3914 } 3915 3916 static void receive_cancel_reply(struct dlm_ls *ls, struct dlm_message *ms) 3917 { 3918 struct dlm_lkb *lkb; 3919 int error; 3920 3921 error = find_lkb(ls, ms->m_remid, &lkb); 3922 if (error) { 3923 log_debug(ls, "receive_cancel_reply from %d no lkb %x", 3924 ms->m_header.h_nodeid, ms->m_remid); 3925 return; 3926 } 3927 3928 _receive_cancel_reply(lkb, ms); 3929 dlm_put_lkb(lkb); 3930 } 3931 3932 static void receive_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms) 3933 { 3934 struct dlm_lkb *lkb; 3935 struct dlm_rsb *r; 3936 int error, ret_nodeid; 3937 3938 error = find_lkb(ls, ms->m_lkid, &lkb); 3939 if (error) { 3940 log_error(ls, "receive_lookup_reply no lkb"); 3941 return; 3942 } 3943 3944 /* ms->m_result is the value returned by dlm_dir_lookup on dir node 3945 FIXME: will a non-zero error ever be returned? */ 3946 3947 r = lkb->lkb_resource; 3948 hold_rsb(r); 3949 lock_rsb(r); 3950 3951 error = remove_from_waiters(lkb, DLM_MSG_LOOKUP_REPLY); 3952 if (error) 3953 goto out; 3954 3955 ret_nodeid = ms->m_nodeid; 3956 if (ret_nodeid == dlm_our_nodeid()) { 3957 r->res_nodeid = 0; 3958 ret_nodeid = 0; 3959 r->res_first_lkid = 0; 3960 } else { 3961 /* set_master() will copy res_nodeid to lkb_nodeid */ 3962 r->res_nodeid = ret_nodeid; 3963 } 3964 3965 if (is_overlap(lkb)) { 3966 log_debug(ls, "receive_lookup_reply %x unlock %x", 3967 lkb->lkb_id, lkb->lkb_flags); 3968 queue_cast_overlap(r, lkb); 3969 unhold_lkb(lkb); /* undoes create_lkb() */ 3970 goto out_list; 3971 } 3972 3973 _request_lock(r, lkb); 3974 3975 out_list: 3976 if (!ret_nodeid) 3977 process_lookup_list(r); 3978 out: 3979 unlock_rsb(r); 3980 put_rsb(r); 3981 dlm_put_lkb(lkb); 3982 } 3983 3984 static void _receive_message(struct dlm_ls *ls, struct dlm_message *ms) 3985 { 3986 if (!dlm_is_member(ls, ms->m_header.h_nodeid)) { 3987 log_debug(ls, "ignore non-member message %d from %d %x %x %d", 3988 ms->m_type, ms->m_header.h_nodeid, ms->m_lkid, 3989 ms->m_remid, ms->m_result); 3990 return; 3991 } 3992 3993 switch (ms->m_type) { 3994 3995 /* messages sent to a master node */ 3996 3997 case DLM_MSG_REQUEST: 3998 receive_request(ls, ms); 3999 break; 4000 4001 case DLM_MSG_CONVERT: 4002 receive_convert(ls, ms); 4003 break; 4004 4005 case DLM_MSG_UNLOCK: 4006 receive_unlock(ls, ms); 4007 break; 4008 4009 case DLM_MSG_CANCEL: 4010 receive_cancel(ls, ms); 4011 break; 4012 4013 /* messages sent from a master node (replies to above) */ 4014 4015 case DLM_MSG_REQUEST_REPLY: 4016 receive_request_reply(ls, ms); 4017 break; 4018 4019 case DLM_MSG_CONVERT_REPLY: 4020 receive_convert_reply(ls, ms); 4021 break; 4022 4023 case DLM_MSG_UNLOCK_REPLY: 4024 receive_unlock_reply(ls, ms); 4025 break; 4026 4027 case DLM_MSG_CANCEL_REPLY: 4028 receive_cancel_reply(ls, ms); 4029 break; 4030 4031 /* messages sent from a master node (only two types of async msg) */ 4032 4033 case DLM_MSG_GRANT: 4034 receive_grant(ls, ms); 4035 break; 4036 4037 case DLM_MSG_BAST: 4038 receive_bast(ls, ms); 4039 break; 4040 4041 /* messages sent to a dir node */ 4042 4043 case DLM_MSG_LOOKUP: 4044 receive_lookup(ls, ms); 4045 break; 4046 4047 case DLM_MSG_REMOVE: 4048 receive_remove(ls, ms); 4049 break; 4050 4051 /* messages sent from a dir node (remove has no reply) */ 4052 4053 case DLM_MSG_LOOKUP_REPLY: 4054 receive_lookup_reply(ls, ms); 4055 break; 4056 4057 /* other messages */ 4058 4059 case DLM_MSG_PURGE: 4060 receive_purge(ls, ms); 4061 break; 4062 4063 default: 4064 log_error(ls, "unknown message type %d", ms->m_type); 4065 } 4066 } 4067 4068 /* If the lockspace is in recovery mode (locking stopped), then normal 4069 messages are saved on the requestqueue for processing after recovery is 4070 done. When not in recovery mode, we wait for dlm_recoverd to drain saved 4071 messages off the requestqueue before we process new ones. This occurs right 4072 after recovery completes when we transition from saving all messages on 4073 requestqueue, to processing all the saved messages, to processing new 4074 messages as they arrive. */ 4075 4076 static void dlm_receive_message(struct dlm_ls *ls, struct dlm_message *ms, 4077 int nodeid) 4078 { 4079 if (dlm_locking_stopped(ls)) { 4080 dlm_add_requestqueue(ls, nodeid, ms); 4081 } else { 4082 dlm_wait_requestqueue(ls); 4083 _receive_message(ls, ms); 4084 } 4085 } 4086 4087 /* This is called by dlm_recoverd to process messages that were saved on 4088 the requestqueue. */ 4089 4090 void dlm_receive_message_saved(struct dlm_ls *ls, struct dlm_message *ms) 4091 { 4092 _receive_message(ls, ms); 4093 } 4094 4095 /* This is called by the midcomms layer when something is received for 4096 the lockspace. It could be either a MSG (normal message sent as part of 4097 standard locking activity) or an RCOM (recovery message sent as part of 4098 lockspace recovery). */ 4099 4100 void dlm_receive_buffer(union dlm_packet *p, int nodeid) 4101 { 4102 struct dlm_header *hd = &p->header; 4103 struct dlm_ls *ls; 4104 int type = 0; 4105 4106 switch (hd->h_cmd) { 4107 case DLM_MSG: 4108 dlm_message_in(&p->message); 4109 type = p->message.m_type; 4110 break; 4111 case DLM_RCOM: 4112 dlm_rcom_in(&p->rcom); 4113 type = p->rcom.rc_type; 4114 break; 4115 default: 4116 log_print("invalid h_cmd %d from %u", hd->h_cmd, nodeid); 4117 return; 4118 } 4119 4120 if (hd->h_nodeid != nodeid) { 4121 log_print("invalid h_nodeid %d from %d lockspace %x", 4122 hd->h_nodeid, nodeid, hd->h_lockspace); 4123 return; 4124 } 4125 4126 ls = dlm_find_lockspace_global(hd->h_lockspace); 4127 if (!ls) { 4128 if (dlm_config.ci_log_debug) 4129 log_print("invalid lockspace %x from %d cmd %d type %d", 4130 hd->h_lockspace, nodeid, hd->h_cmd, type); 4131 4132 if (hd->h_cmd == DLM_RCOM && type == DLM_RCOM_STATUS) 4133 dlm_send_ls_not_ready(nodeid, &p->rcom); 4134 return; 4135 } 4136 4137 /* this rwsem allows dlm_ls_stop() to wait for all dlm_recv threads to 4138 be inactive (in this ls) before transitioning to recovery mode */ 4139 4140 down_read(&ls->ls_recv_active); 4141 if (hd->h_cmd == DLM_MSG) 4142 dlm_receive_message(ls, &p->message, nodeid); 4143 else 4144 dlm_receive_rcom(ls, &p->rcom, nodeid); 4145 up_read(&ls->ls_recv_active); 4146 4147 dlm_put_lockspace(ls); 4148 } 4149 4150 static void recover_convert_waiter(struct dlm_ls *ls, struct dlm_lkb *lkb, 4151 struct dlm_message *ms_stub) 4152 { 4153 if (middle_conversion(lkb)) { 4154 hold_lkb(lkb); 4155 memset(ms_stub, 0, sizeof(struct dlm_message)); 4156 ms_stub->m_flags = DLM_IFL_STUB_MS; 4157 ms_stub->m_type = DLM_MSG_CONVERT_REPLY; 4158 ms_stub->m_result = -EINPROGRESS; 4159 ms_stub->m_header.h_nodeid = lkb->lkb_nodeid; 4160 _receive_convert_reply(lkb, ms_stub); 4161 4162 /* Same special case as in receive_rcom_lock_args() */ 4163 lkb->lkb_grmode = DLM_LOCK_IV; 4164 rsb_set_flag(lkb->lkb_resource, RSB_RECOVER_CONVERT); 4165 unhold_lkb(lkb); 4166 4167 } else if (lkb->lkb_rqmode >= lkb->lkb_grmode) { 4168 lkb->lkb_flags |= DLM_IFL_RESEND; 4169 } 4170 4171 /* lkb->lkb_rqmode < lkb->lkb_grmode shouldn't happen since down 4172 conversions are async; there's no reply from the remote master */ 4173 } 4174 4175 /* A waiting lkb needs recovery if the master node has failed, or 4176 the master node is changing (only when no directory is used) */ 4177 4178 static int waiter_needs_recovery(struct dlm_ls *ls, struct dlm_lkb *lkb) 4179 { 4180 if (dlm_is_removed(ls, lkb->lkb_nodeid)) 4181 return 1; 4182 4183 if (!dlm_no_directory(ls)) 4184 return 0; 4185 4186 if (dlm_dir_nodeid(lkb->lkb_resource) != lkb->lkb_nodeid) 4187 return 1; 4188 4189 return 0; 4190 } 4191 4192 /* Recovery for locks that are waiting for replies from nodes that are now 4193 gone. We can just complete unlocks and cancels by faking a reply from the 4194 dead node. Requests and up-conversions we flag to be resent after 4195 recovery. Down-conversions can just be completed with a fake reply like 4196 unlocks. Conversions between PR and CW need special attention. */ 4197 4198 void dlm_recover_waiters_pre(struct dlm_ls *ls) 4199 { 4200 struct dlm_lkb *lkb, *safe; 4201 struct dlm_message *ms_stub; 4202 int wait_type, stub_unlock_result, stub_cancel_result; 4203 4204 ms_stub = kmalloc(sizeof(struct dlm_message), GFP_KERNEL); 4205 if (!ms_stub) { 4206 log_error(ls, "dlm_recover_waiters_pre no mem"); 4207 return; 4208 } 4209 4210 mutex_lock(&ls->ls_waiters_mutex); 4211 4212 list_for_each_entry_safe(lkb, safe, &ls->ls_waiters, lkb_wait_reply) { 4213 4214 /* exclude debug messages about unlocks because there can be so 4215 many and they aren't very interesting */ 4216 4217 if (lkb->lkb_wait_type != DLM_MSG_UNLOCK) { 4218 log_debug(ls, "recover_waiter %x nodeid %d " 4219 "msg %d to %d", lkb->lkb_id, lkb->lkb_nodeid, 4220 lkb->lkb_wait_type, lkb->lkb_wait_nodeid); 4221 } 4222 4223 /* all outstanding lookups, regardless of destination will be 4224 resent after recovery is done */ 4225 4226 if (lkb->lkb_wait_type == DLM_MSG_LOOKUP) { 4227 lkb->lkb_flags |= DLM_IFL_RESEND; 4228 continue; 4229 } 4230 4231 if (!waiter_needs_recovery(ls, lkb)) 4232 continue; 4233 4234 wait_type = lkb->lkb_wait_type; 4235 stub_unlock_result = -DLM_EUNLOCK; 4236 stub_cancel_result = -DLM_ECANCEL; 4237 4238 /* Main reply may have been received leaving a zero wait_type, 4239 but a reply for the overlapping op may not have been 4240 received. In that case we need to fake the appropriate 4241 reply for the overlap op. */ 4242 4243 if (!wait_type) { 4244 if (is_overlap_cancel(lkb)) { 4245 wait_type = DLM_MSG_CANCEL; 4246 if (lkb->lkb_grmode == DLM_LOCK_IV) 4247 stub_cancel_result = 0; 4248 } 4249 if (is_overlap_unlock(lkb)) { 4250 wait_type = DLM_MSG_UNLOCK; 4251 if (lkb->lkb_grmode == DLM_LOCK_IV) 4252 stub_unlock_result = -ENOENT; 4253 } 4254 4255 log_debug(ls, "rwpre overlap %x %x %d %d %d", 4256 lkb->lkb_id, lkb->lkb_flags, wait_type, 4257 stub_cancel_result, stub_unlock_result); 4258 } 4259 4260 switch (wait_type) { 4261 4262 case DLM_MSG_REQUEST: 4263 lkb->lkb_flags |= DLM_IFL_RESEND; 4264 break; 4265 4266 case DLM_MSG_CONVERT: 4267 recover_convert_waiter(ls, lkb, ms_stub); 4268 break; 4269 4270 case DLM_MSG_UNLOCK: 4271 hold_lkb(lkb); 4272 memset(ms_stub, 0, sizeof(struct dlm_message)); 4273 ms_stub->m_flags = DLM_IFL_STUB_MS; 4274 ms_stub->m_type = DLM_MSG_UNLOCK_REPLY; 4275 ms_stub->m_result = stub_unlock_result; 4276 ms_stub->m_header.h_nodeid = lkb->lkb_nodeid; 4277 _receive_unlock_reply(lkb, ms_stub); 4278 dlm_put_lkb(lkb); 4279 break; 4280 4281 case DLM_MSG_CANCEL: 4282 hold_lkb(lkb); 4283 memset(ms_stub, 0, sizeof(struct dlm_message)); 4284 ms_stub->m_flags = DLM_IFL_STUB_MS; 4285 ms_stub->m_type = DLM_MSG_CANCEL_REPLY; 4286 ms_stub->m_result = stub_cancel_result; 4287 ms_stub->m_header.h_nodeid = lkb->lkb_nodeid; 4288 _receive_cancel_reply(lkb, ms_stub); 4289 dlm_put_lkb(lkb); 4290 break; 4291 4292 default: 4293 log_error(ls, "invalid lkb wait_type %d %d", 4294 lkb->lkb_wait_type, wait_type); 4295 } 4296 schedule(); 4297 } 4298 mutex_unlock(&ls->ls_waiters_mutex); 4299 kfree(ms_stub); 4300 } 4301 4302 static struct dlm_lkb *find_resend_waiter(struct dlm_ls *ls) 4303 { 4304 struct dlm_lkb *lkb; 4305 int found = 0; 4306 4307 mutex_lock(&ls->ls_waiters_mutex); 4308 list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) { 4309 if (lkb->lkb_flags & DLM_IFL_RESEND) { 4310 hold_lkb(lkb); 4311 found = 1; 4312 break; 4313 } 4314 } 4315 mutex_unlock(&ls->ls_waiters_mutex); 4316 4317 if (!found) 4318 lkb = NULL; 4319 return lkb; 4320 } 4321 4322 /* Deal with lookups and lkb's marked RESEND from _pre. We may now be the 4323 master or dir-node for r. Processing the lkb may result in it being placed 4324 back on waiters. */ 4325 4326 /* We do this after normal locking has been enabled and any saved messages 4327 (in requestqueue) have been processed. We should be confident that at 4328 this point we won't get or process a reply to any of these waiting 4329 operations. But, new ops may be coming in on the rsbs/locks here from 4330 userspace or remotely. */ 4331 4332 /* there may have been an overlap unlock/cancel prior to recovery or after 4333 recovery. if before, the lkb may still have a pos wait_count; if after, the 4334 overlap flag would just have been set and nothing new sent. we can be 4335 confident here than any replies to either the initial op or overlap ops 4336 prior to recovery have been received. */ 4337 4338 int dlm_recover_waiters_post(struct dlm_ls *ls) 4339 { 4340 struct dlm_lkb *lkb; 4341 struct dlm_rsb *r; 4342 int error = 0, mstype, err, oc, ou; 4343 4344 while (1) { 4345 if (dlm_locking_stopped(ls)) { 4346 log_debug(ls, "recover_waiters_post aborted"); 4347 error = -EINTR; 4348 break; 4349 } 4350 4351 lkb = find_resend_waiter(ls); 4352 if (!lkb) 4353 break; 4354 4355 r = lkb->lkb_resource; 4356 hold_rsb(r); 4357 lock_rsb(r); 4358 4359 mstype = lkb->lkb_wait_type; 4360 oc = is_overlap_cancel(lkb); 4361 ou = is_overlap_unlock(lkb); 4362 err = 0; 4363 4364 log_debug(ls, "recover_waiter %x nodeid %d msg %d r_nodeid %d", 4365 lkb->lkb_id, lkb->lkb_nodeid, mstype, r->res_nodeid); 4366 4367 /* At this point we assume that we won't get a reply to any 4368 previous op or overlap op on this lock. First, do a big 4369 remove_from_waiters() for all previous ops. */ 4370 4371 lkb->lkb_flags &= ~DLM_IFL_RESEND; 4372 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK; 4373 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL; 4374 lkb->lkb_wait_type = 0; 4375 lkb->lkb_wait_count = 0; 4376 mutex_lock(&ls->ls_waiters_mutex); 4377 list_del_init(&lkb->lkb_wait_reply); 4378 mutex_unlock(&ls->ls_waiters_mutex); 4379 unhold_lkb(lkb); /* for waiters list */ 4380 4381 if (oc || ou) { 4382 /* do an unlock or cancel instead of resending */ 4383 switch (mstype) { 4384 case DLM_MSG_LOOKUP: 4385 case DLM_MSG_REQUEST: 4386 queue_cast(r, lkb, ou ? -DLM_EUNLOCK : 4387 -DLM_ECANCEL); 4388 unhold_lkb(lkb); /* undoes create_lkb() */ 4389 break; 4390 case DLM_MSG_CONVERT: 4391 if (oc) { 4392 queue_cast(r, lkb, -DLM_ECANCEL); 4393 } else { 4394 lkb->lkb_exflags |= DLM_LKF_FORCEUNLOCK; 4395 _unlock_lock(r, lkb); 4396 } 4397 break; 4398 default: 4399 err = 1; 4400 } 4401 } else { 4402 switch (mstype) { 4403 case DLM_MSG_LOOKUP: 4404 case DLM_MSG_REQUEST: 4405 _request_lock(r, lkb); 4406 if (is_master(r)) 4407 confirm_master(r, 0); 4408 break; 4409 case DLM_MSG_CONVERT: 4410 _convert_lock(r, lkb); 4411 break; 4412 default: 4413 err = 1; 4414 } 4415 } 4416 4417 if (err) 4418 log_error(ls, "recover_waiters_post %x %d %x %d %d", 4419 lkb->lkb_id, mstype, lkb->lkb_flags, oc, ou); 4420 unlock_rsb(r); 4421 put_rsb(r); 4422 dlm_put_lkb(lkb); 4423 } 4424 4425 return error; 4426 } 4427 4428 static void purge_queue(struct dlm_rsb *r, struct list_head *queue, 4429 int (*test)(struct dlm_ls *ls, struct dlm_lkb *lkb)) 4430 { 4431 struct dlm_ls *ls = r->res_ls; 4432 struct dlm_lkb *lkb, *safe; 4433 4434 list_for_each_entry_safe(lkb, safe, queue, lkb_statequeue) { 4435 if (test(ls, lkb)) { 4436 rsb_set_flag(r, RSB_LOCKS_PURGED); 4437 del_lkb(r, lkb); 4438 /* this put should free the lkb */ 4439 if (!dlm_put_lkb(lkb)) 4440 log_error(ls, "purged lkb not released"); 4441 } 4442 } 4443 } 4444 4445 static int purge_dead_test(struct dlm_ls *ls, struct dlm_lkb *lkb) 4446 { 4447 return (is_master_copy(lkb) && dlm_is_removed(ls, lkb->lkb_nodeid)); 4448 } 4449 4450 static int purge_mstcpy_test(struct dlm_ls *ls, struct dlm_lkb *lkb) 4451 { 4452 return is_master_copy(lkb); 4453 } 4454 4455 static void purge_dead_locks(struct dlm_rsb *r) 4456 { 4457 purge_queue(r, &r->res_grantqueue, &purge_dead_test); 4458 purge_queue(r, &r->res_convertqueue, &purge_dead_test); 4459 purge_queue(r, &r->res_waitqueue, &purge_dead_test); 4460 } 4461 4462 void dlm_purge_mstcpy_locks(struct dlm_rsb *r) 4463 { 4464 purge_queue(r, &r->res_grantqueue, &purge_mstcpy_test); 4465 purge_queue(r, &r->res_convertqueue, &purge_mstcpy_test); 4466 purge_queue(r, &r->res_waitqueue, &purge_mstcpy_test); 4467 } 4468 4469 /* Get rid of locks held by nodes that are gone. */ 4470 4471 int dlm_purge_locks(struct dlm_ls *ls) 4472 { 4473 struct dlm_rsb *r; 4474 4475 log_debug(ls, "dlm_purge_locks"); 4476 4477 down_write(&ls->ls_root_sem); 4478 list_for_each_entry(r, &ls->ls_root_list, res_root_list) { 4479 hold_rsb(r); 4480 lock_rsb(r); 4481 if (is_master(r)) 4482 purge_dead_locks(r); 4483 unlock_rsb(r); 4484 unhold_rsb(r); 4485 4486 schedule(); 4487 } 4488 up_write(&ls->ls_root_sem); 4489 4490 return 0; 4491 } 4492 4493 static struct dlm_rsb *find_purged_rsb(struct dlm_ls *ls, int bucket) 4494 { 4495 struct rb_node *n; 4496 struct dlm_rsb *r, *r_ret = NULL; 4497 4498 spin_lock(&ls->ls_rsbtbl[bucket].lock); 4499 for (n = rb_first(&ls->ls_rsbtbl[bucket].keep); n; n = rb_next(n)) { 4500 r = rb_entry(n, struct dlm_rsb, res_hashnode); 4501 if (!rsb_flag(r, RSB_LOCKS_PURGED)) 4502 continue; 4503 hold_rsb(r); 4504 rsb_clear_flag(r, RSB_LOCKS_PURGED); 4505 r_ret = r; 4506 break; 4507 } 4508 spin_unlock(&ls->ls_rsbtbl[bucket].lock); 4509 return r_ret; 4510 } 4511 4512 void dlm_grant_after_purge(struct dlm_ls *ls) 4513 { 4514 struct dlm_rsb *r; 4515 int bucket = 0; 4516 4517 while (1) { 4518 r = find_purged_rsb(ls, bucket); 4519 if (!r) { 4520 if (bucket == ls->ls_rsbtbl_size - 1) 4521 break; 4522 bucket++; 4523 continue; 4524 } 4525 lock_rsb(r); 4526 if (is_master(r)) { 4527 grant_pending_locks(r); 4528 confirm_master(r, 0); 4529 } 4530 unlock_rsb(r); 4531 put_rsb(r); 4532 schedule(); 4533 } 4534 } 4535 4536 static struct dlm_lkb *search_remid_list(struct list_head *head, int nodeid, 4537 uint32_t remid) 4538 { 4539 struct dlm_lkb *lkb; 4540 4541 list_for_each_entry(lkb, head, lkb_statequeue) { 4542 if (lkb->lkb_nodeid == nodeid && lkb->lkb_remid == remid) 4543 return lkb; 4544 } 4545 return NULL; 4546 } 4547 4548 static struct dlm_lkb *search_remid(struct dlm_rsb *r, int nodeid, 4549 uint32_t remid) 4550 { 4551 struct dlm_lkb *lkb; 4552 4553 lkb = search_remid_list(&r->res_grantqueue, nodeid, remid); 4554 if (lkb) 4555 return lkb; 4556 lkb = search_remid_list(&r->res_convertqueue, nodeid, remid); 4557 if (lkb) 4558 return lkb; 4559 lkb = search_remid_list(&r->res_waitqueue, nodeid, remid); 4560 if (lkb) 4561 return lkb; 4562 return NULL; 4563 } 4564 4565 /* needs at least dlm_rcom + rcom_lock */ 4566 static int receive_rcom_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb, 4567 struct dlm_rsb *r, struct dlm_rcom *rc) 4568 { 4569 struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf; 4570 4571 lkb->lkb_nodeid = rc->rc_header.h_nodeid; 4572 lkb->lkb_ownpid = le32_to_cpu(rl->rl_ownpid); 4573 lkb->lkb_remid = le32_to_cpu(rl->rl_lkid); 4574 lkb->lkb_exflags = le32_to_cpu(rl->rl_exflags); 4575 lkb->lkb_flags = le32_to_cpu(rl->rl_flags) & 0x0000FFFF; 4576 lkb->lkb_flags |= DLM_IFL_MSTCPY; 4577 lkb->lkb_lvbseq = le32_to_cpu(rl->rl_lvbseq); 4578 lkb->lkb_rqmode = rl->rl_rqmode; 4579 lkb->lkb_grmode = rl->rl_grmode; 4580 /* don't set lkb_status because add_lkb wants to itself */ 4581 4582 lkb->lkb_bastfn = (rl->rl_asts & DLM_CB_BAST) ? &fake_bastfn : NULL; 4583 lkb->lkb_astfn = (rl->rl_asts & DLM_CB_CAST) ? &fake_astfn : NULL; 4584 4585 if (lkb->lkb_exflags & DLM_LKF_VALBLK) { 4586 int lvblen = rc->rc_header.h_length - sizeof(struct dlm_rcom) - 4587 sizeof(struct rcom_lock); 4588 if (lvblen > ls->ls_lvblen) 4589 return -EINVAL; 4590 lkb->lkb_lvbptr = dlm_allocate_lvb(ls); 4591 if (!lkb->lkb_lvbptr) 4592 return -ENOMEM; 4593 memcpy(lkb->lkb_lvbptr, rl->rl_lvb, lvblen); 4594 } 4595 4596 /* Conversions between PR and CW (middle modes) need special handling. 4597 The real granted mode of these converting locks cannot be determined 4598 until all locks have been rebuilt on the rsb (recover_conversion) */ 4599 4600 if (rl->rl_wait_type == cpu_to_le16(DLM_MSG_CONVERT) && 4601 middle_conversion(lkb)) { 4602 rl->rl_status = DLM_LKSTS_CONVERT; 4603 lkb->lkb_grmode = DLM_LOCK_IV; 4604 rsb_set_flag(r, RSB_RECOVER_CONVERT); 4605 } 4606 4607 return 0; 4608 } 4609 4610 /* This lkb may have been recovered in a previous aborted recovery so we need 4611 to check if the rsb already has an lkb with the given remote nodeid/lkid. 4612 If so we just send back a standard reply. If not, we create a new lkb with 4613 the given values and send back our lkid. We send back our lkid by sending 4614 back the rcom_lock struct we got but with the remid field filled in. */ 4615 4616 /* needs at least dlm_rcom + rcom_lock */ 4617 int dlm_recover_master_copy(struct dlm_ls *ls, struct dlm_rcom *rc) 4618 { 4619 struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf; 4620 struct dlm_rsb *r; 4621 struct dlm_lkb *lkb; 4622 int error; 4623 4624 if (rl->rl_parent_lkid) { 4625 error = -EOPNOTSUPP; 4626 goto out; 4627 } 4628 4629 error = find_rsb(ls, rl->rl_name, le16_to_cpu(rl->rl_namelen), 4630 R_MASTER, &r); 4631 if (error) 4632 goto out; 4633 4634 lock_rsb(r); 4635 4636 lkb = search_remid(r, rc->rc_header.h_nodeid, le32_to_cpu(rl->rl_lkid)); 4637 if (lkb) { 4638 error = -EEXIST; 4639 goto out_remid; 4640 } 4641 4642 error = create_lkb(ls, &lkb); 4643 if (error) 4644 goto out_unlock; 4645 4646 error = receive_rcom_lock_args(ls, lkb, r, rc); 4647 if (error) { 4648 __put_lkb(ls, lkb); 4649 goto out_unlock; 4650 } 4651 4652 attach_lkb(r, lkb); 4653 add_lkb(r, lkb, rl->rl_status); 4654 error = 0; 4655 4656 out_remid: 4657 /* this is the new value returned to the lock holder for 4658 saving in its process-copy lkb */ 4659 rl->rl_remid = cpu_to_le32(lkb->lkb_id); 4660 4661 out_unlock: 4662 unlock_rsb(r); 4663 put_rsb(r); 4664 out: 4665 if (error) 4666 log_debug(ls, "recover_master_copy %d %x", error, 4667 le32_to_cpu(rl->rl_lkid)); 4668 rl->rl_result = cpu_to_le32(error); 4669 return error; 4670 } 4671 4672 /* needs at least dlm_rcom + rcom_lock */ 4673 int dlm_recover_process_copy(struct dlm_ls *ls, struct dlm_rcom *rc) 4674 { 4675 struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf; 4676 struct dlm_rsb *r; 4677 struct dlm_lkb *lkb; 4678 int error; 4679 4680 error = find_lkb(ls, le32_to_cpu(rl->rl_lkid), &lkb); 4681 if (error) { 4682 log_error(ls, "recover_process_copy no lkid %x", 4683 le32_to_cpu(rl->rl_lkid)); 4684 return error; 4685 } 4686 4687 DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb);); 4688 4689 error = le32_to_cpu(rl->rl_result); 4690 4691 r = lkb->lkb_resource; 4692 hold_rsb(r); 4693 lock_rsb(r); 4694 4695 switch (error) { 4696 case -EBADR: 4697 /* There's a chance the new master received our lock before 4698 dlm_recover_master_reply(), this wouldn't happen if we did 4699 a barrier between recover_masters and recover_locks. */ 4700 log_debug(ls, "master copy not ready %x r %lx %s", lkb->lkb_id, 4701 (unsigned long)r, r->res_name); 4702 dlm_send_rcom_lock(r, lkb); 4703 goto out; 4704 case -EEXIST: 4705 log_debug(ls, "master copy exists %x", lkb->lkb_id); 4706 /* fall through */ 4707 case 0: 4708 lkb->lkb_remid = le32_to_cpu(rl->rl_remid); 4709 break; 4710 default: 4711 log_error(ls, "dlm_recover_process_copy unknown error %d %x", 4712 error, lkb->lkb_id); 4713 } 4714 4715 /* an ack for dlm_recover_locks() which waits for replies from 4716 all the locks it sends to new masters */ 4717 dlm_recovered_lock(r); 4718 out: 4719 unlock_rsb(r); 4720 put_rsb(r); 4721 dlm_put_lkb(lkb); 4722 4723 return 0; 4724 } 4725 4726 int dlm_user_request(struct dlm_ls *ls, struct dlm_user_args *ua, 4727 int mode, uint32_t flags, void *name, unsigned int namelen, 4728 unsigned long timeout_cs) 4729 { 4730 struct dlm_lkb *lkb; 4731 struct dlm_args args; 4732 int error; 4733 4734 dlm_lock_recovery(ls); 4735 4736 error = create_lkb(ls, &lkb); 4737 if (error) { 4738 kfree(ua); 4739 goto out; 4740 } 4741 4742 if (flags & DLM_LKF_VALBLK) { 4743 ua->lksb.sb_lvbptr = kzalloc(DLM_USER_LVB_LEN, GFP_NOFS); 4744 if (!ua->lksb.sb_lvbptr) { 4745 kfree(ua); 4746 __put_lkb(ls, lkb); 4747 error = -ENOMEM; 4748 goto out; 4749 } 4750 } 4751 4752 /* After ua is attached to lkb it will be freed by dlm_free_lkb(). 4753 When DLM_IFL_USER is set, the dlm knows that this is a userspace 4754 lock and that lkb_astparam is the dlm_user_args structure. */ 4755 4756 error = set_lock_args(mode, &ua->lksb, flags, namelen, timeout_cs, 4757 fake_astfn, ua, fake_bastfn, &args); 4758 lkb->lkb_flags |= DLM_IFL_USER; 4759 4760 if (error) { 4761 __put_lkb(ls, lkb); 4762 goto out; 4763 } 4764 4765 error = request_lock(ls, lkb, name, namelen, &args); 4766 4767 switch (error) { 4768 case 0: 4769 break; 4770 case -EINPROGRESS: 4771 error = 0; 4772 break; 4773 case -EAGAIN: 4774 error = 0; 4775 /* fall through */ 4776 default: 4777 __put_lkb(ls, lkb); 4778 goto out; 4779 } 4780 4781 /* add this new lkb to the per-process list of locks */ 4782 spin_lock(&ua->proc->locks_spin); 4783 hold_lkb(lkb); 4784 list_add_tail(&lkb->lkb_ownqueue, &ua->proc->locks); 4785 spin_unlock(&ua->proc->locks_spin); 4786 out: 4787 dlm_unlock_recovery(ls); 4788 return error; 4789 } 4790 4791 int dlm_user_convert(struct dlm_ls *ls, struct dlm_user_args *ua_tmp, 4792 int mode, uint32_t flags, uint32_t lkid, char *lvb_in, 4793 unsigned long timeout_cs) 4794 { 4795 struct dlm_lkb *lkb; 4796 struct dlm_args args; 4797 struct dlm_user_args *ua; 4798 int error; 4799 4800 dlm_lock_recovery(ls); 4801 4802 error = find_lkb(ls, lkid, &lkb); 4803 if (error) 4804 goto out; 4805 4806 /* user can change the params on its lock when it converts it, or 4807 add an lvb that didn't exist before */ 4808 4809 ua = lkb->lkb_ua; 4810 4811 if (flags & DLM_LKF_VALBLK && !ua->lksb.sb_lvbptr) { 4812 ua->lksb.sb_lvbptr = kzalloc(DLM_USER_LVB_LEN, GFP_NOFS); 4813 if (!ua->lksb.sb_lvbptr) { 4814 error = -ENOMEM; 4815 goto out_put; 4816 } 4817 } 4818 if (lvb_in && ua->lksb.sb_lvbptr) 4819 memcpy(ua->lksb.sb_lvbptr, lvb_in, DLM_USER_LVB_LEN); 4820 4821 ua->xid = ua_tmp->xid; 4822 ua->castparam = ua_tmp->castparam; 4823 ua->castaddr = ua_tmp->castaddr; 4824 ua->bastparam = ua_tmp->bastparam; 4825 ua->bastaddr = ua_tmp->bastaddr; 4826 ua->user_lksb = ua_tmp->user_lksb; 4827 4828 error = set_lock_args(mode, &ua->lksb, flags, 0, timeout_cs, 4829 fake_astfn, ua, fake_bastfn, &args); 4830 if (error) 4831 goto out_put; 4832 4833 error = convert_lock(ls, lkb, &args); 4834 4835 if (error == -EINPROGRESS || error == -EAGAIN || error == -EDEADLK) 4836 error = 0; 4837 out_put: 4838 dlm_put_lkb(lkb); 4839 out: 4840 dlm_unlock_recovery(ls); 4841 kfree(ua_tmp); 4842 return error; 4843 } 4844 4845 int dlm_user_unlock(struct dlm_ls *ls, struct dlm_user_args *ua_tmp, 4846 uint32_t flags, uint32_t lkid, char *lvb_in) 4847 { 4848 struct dlm_lkb *lkb; 4849 struct dlm_args args; 4850 struct dlm_user_args *ua; 4851 int error; 4852 4853 dlm_lock_recovery(ls); 4854 4855 error = find_lkb(ls, lkid, &lkb); 4856 if (error) 4857 goto out; 4858 4859 ua = lkb->lkb_ua; 4860 4861 if (lvb_in && ua->lksb.sb_lvbptr) 4862 memcpy(ua->lksb.sb_lvbptr, lvb_in, DLM_USER_LVB_LEN); 4863 if (ua_tmp->castparam) 4864 ua->castparam = ua_tmp->castparam; 4865 ua->user_lksb = ua_tmp->user_lksb; 4866 4867 error = set_unlock_args(flags, ua, &args); 4868 if (error) 4869 goto out_put; 4870 4871 error = unlock_lock(ls, lkb, &args); 4872 4873 if (error == -DLM_EUNLOCK) 4874 error = 0; 4875 /* from validate_unlock_args() */ 4876 if (error == -EBUSY && (flags & DLM_LKF_FORCEUNLOCK)) 4877 error = 0; 4878 if (error) 4879 goto out_put; 4880 4881 spin_lock(&ua->proc->locks_spin); 4882 /* dlm_user_add_cb() may have already taken lkb off the proc list */ 4883 if (!list_empty(&lkb->lkb_ownqueue)) 4884 list_move(&lkb->lkb_ownqueue, &ua->proc->unlocking); 4885 spin_unlock(&ua->proc->locks_spin); 4886 out_put: 4887 dlm_put_lkb(lkb); 4888 out: 4889 dlm_unlock_recovery(ls); 4890 kfree(ua_tmp); 4891 return error; 4892 } 4893 4894 int dlm_user_cancel(struct dlm_ls *ls, struct dlm_user_args *ua_tmp, 4895 uint32_t flags, uint32_t lkid) 4896 { 4897 struct dlm_lkb *lkb; 4898 struct dlm_args args; 4899 struct dlm_user_args *ua; 4900 int error; 4901 4902 dlm_lock_recovery(ls); 4903 4904 error = find_lkb(ls, lkid, &lkb); 4905 if (error) 4906 goto out; 4907 4908 ua = lkb->lkb_ua; 4909 if (ua_tmp->castparam) 4910 ua->castparam = ua_tmp->castparam; 4911 ua->user_lksb = ua_tmp->user_lksb; 4912 4913 error = set_unlock_args(flags, ua, &args); 4914 if (error) 4915 goto out_put; 4916 4917 error = cancel_lock(ls, lkb, &args); 4918 4919 if (error == -DLM_ECANCEL) 4920 error = 0; 4921 /* from validate_unlock_args() */ 4922 if (error == -EBUSY) 4923 error = 0; 4924 out_put: 4925 dlm_put_lkb(lkb); 4926 out: 4927 dlm_unlock_recovery(ls); 4928 kfree(ua_tmp); 4929 return error; 4930 } 4931 4932 int dlm_user_deadlock(struct dlm_ls *ls, uint32_t flags, uint32_t lkid) 4933 { 4934 struct dlm_lkb *lkb; 4935 struct dlm_args args; 4936 struct dlm_user_args *ua; 4937 struct dlm_rsb *r; 4938 int error; 4939 4940 dlm_lock_recovery(ls); 4941 4942 error = find_lkb(ls, lkid, &lkb); 4943 if (error) 4944 goto out; 4945 4946 ua = lkb->lkb_ua; 4947 4948 error = set_unlock_args(flags, ua, &args); 4949 if (error) 4950 goto out_put; 4951 4952 /* same as cancel_lock(), but set DEADLOCK_CANCEL after lock_rsb */ 4953 4954 r = lkb->lkb_resource; 4955 hold_rsb(r); 4956 lock_rsb(r); 4957 4958 error = validate_unlock_args(lkb, &args); 4959 if (error) 4960 goto out_r; 4961 lkb->lkb_flags |= DLM_IFL_DEADLOCK_CANCEL; 4962 4963 error = _cancel_lock(r, lkb); 4964 out_r: 4965 unlock_rsb(r); 4966 put_rsb(r); 4967 4968 if (error == -DLM_ECANCEL) 4969 error = 0; 4970 /* from validate_unlock_args() */ 4971 if (error == -EBUSY) 4972 error = 0; 4973 out_put: 4974 dlm_put_lkb(lkb); 4975 out: 4976 dlm_unlock_recovery(ls); 4977 return error; 4978 } 4979 4980 /* lkb's that are removed from the waiters list by revert are just left on the 4981 orphans list with the granted orphan locks, to be freed by purge */ 4982 4983 static int orphan_proc_lock(struct dlm_ls *ls, struct dlm_lkb *lkb) 4984 { 4985 struct dlm_args args; 4986 int error; 4987 4988 hold_lkb(lkb); 4989 mutex_lock(&ls->ls_orphans_mutex); 4990 list_add_tail(&lkb->lkb_ownqueue, &ls->ls_orphans); 4991 mutex_unlock(&ls->ls_orphans_mutex); 4992 4993 set_unlock_args(0, lkb->lkb_ua, &args); 4994 4995 error = cancel_lock(ls, lkb, &args); 4996 if (error == -DLM_ECANCEL) 4997 error = 0; 4998 return error; 4999 } 5000 5001 /* The force flag allows the unlock to go ahead even if the lkb isn't granted. 5002 Regardless of what rsb queue the lock is on, it's removed and freed. */ 5003 5004 static int unlock_proc_lock(struct dlm_ls *ls, struct dlm_lkb *lkb) 5005 { 5006 struct dlm_args args; 5007 int error; 5008 5009 set_unlock_args(DLM_LKF_FORCEUNLOCK, lkb->lkb_ua, &args); 5010 5011 error = unlock_lock(ls, lkb, &args); 5012 if (error == -DLM_EUNLOCK) 5013 error = 0; 5014 return error; 5015 } 5016 5017 /* We have to release clear_proc_locks mutex before calling unlock_proc_lock() 5018 (which does lock_rsb) due to deadlock with receiving a message that does 5019 lock_rsb followed by dlm_user_add_cb() */ 5020 5021 static struct dlm_lkb *del_proc_lock(struct dlm_ls *ls, 5022 struct dlm_user_proc *proc) 5023 { 5024 struct dlm_lkb *lkb = NULL; 5025 5026 mutex_lock(&ls->ls_clear_proc_locks); 5027 if (list_empty(&proc->locks)) 5028 goto out; 5029 5030 lkb = list_entry(proc->locks.next, struct dlm_lkb, lkb_ownqueue); 5031 list_del_init(&lkb->lkb_ownqueue); 5032 5033 if (lkb->lkb_exflags & DLM_LKF_PERSISTENT) 5034 lkb->lkb_flags |= DLM_IFL_ORPHAN; 5035 else 5036 lkb->lkb_flags |= DLM_IFL_DEAD; 5037 out: 5038 mutex_unlock(&ls->ls_clear_proc_locks); 5039 return lkb; 5040 } 5041 5042 /* The ls_clear_proc_locks mutex protects against dlm_user_add_cb() which 5043 1) references lkb->ua which we free here and 2) adds lkbs to proc->asts, 5044 which we clear here. */ 5045 5046 /* proc CLOSING flag is set so no more device_reads should look at proc->asts 5047 list, and no more device_writes should add lkb's to proc->locks list; so we 5048 shouldn't need to take asts_spin or locks_spin here. this assumes that 5049 device reads/writes/closes are serialized -- FIXME: we may need to serialize 5050 them ourself. */ 5051 5052 void dlm_clear_proc_locks(struct dlm_ls *ls, struct dlm_user_proc *proc) 5053 { 5054 struct dlm_lkb *lkb, *safe; 5055 5056 dlm_lock_recovery(ls); 5057 5058 while (1) { 5059 lkb = del_proc_lock(ls, proc); 5060 if (!lkb) 5061 break; 5062 del_timeout(lkb); 5063 if (lkb->lkb_exflags & DLM_LKF_PERSISTENT) 5064 orphan_proc_lock(ls, lkb); 5065 else 5066 unlock_proc_lock(ls, lkb); 5067 5068 /* this removes the reference for the proc->locks list 5069 added by dlm_user_request, it may result in the lkb 5070 being freed */ 5071 5072 dlm_put_lkb(lkb); 5073 } 5074 5075 mutex_lock(&ls->ls_clear_proc_locks); 5076 5077 /* in-progress unlocks */ 5078 list_for_each_entry_safe(lkb, safe, &proc->unlocking, lkb_ownqueue) { 5079 list_del_init(&lkb->lkb_ownqueue); 5080 lkb->lkb_flags |= DLM_IFL_DEAD; 5081 dlm_put_lkb(lkb); 5082 } 5083 5084 list_for_each_entry_safe(lkb, safe, &proc->asts, lkb_cb_list) { 5085 memset(&lkb->lkb_callbacks, 0, 5086 sizeof(struct dlm_callback) * DLM_CALLBACKS_SIZE); 5087 list_del_init(&lkb->lkb_cb_list); 5088 dlm_put_lkb(lkb); 5089 } 5090 5091 mutex_unlock(&ls->ls_clear_proc_locks); 5092 dlm_unlock_recovery(ls); 5093 } 5094 5095 static void purge_proc_locks(struct dlm_ls *ls, struct dlm_user_proc *proc) 5096 { 5097 struct dlm_lkb *lkb, *safe; 5098 5099 while (1) { 5100 lkb = NULL; 5101 spin_lock(&proc->locks_spin); 5102 if (!list_empty(&proc->locks)) { 5103 lkb = list_entry(proc->locks.next, struct dlm_lkb, 5104 lkb_ownqueue); 5105 list_del_init(&lkb->lkb_ownqueue); 5106 } 5107 spin_unlock(&proc->locks_spin); 5108 5109 if (!lkb) 5110 break; 5111 5112 lkb->lkb_flags |= DLM_IFL_DEAD; 5113 unlock_proc_lock(ls, lkb); 5114 dlm_put_lkb(lkb); /* ref from proc->locks list */ 5115 } 5116 5117 spin_lock(&proc->locks_spin); 5118 list_for_each_entry_safe(lkb, safe, &proc->unlocking, lkb_ownqueue) { 5119 list_del_init(&lkb->lkb_ownqueue); 5120 lkb->lkb_flags |= DLM_IFL_DEAD; 5121 dlm_put_lkb(lkb); 5122 } 5123 spin_unlock(&proc->locks_spin); 5124 5125 spin_lock(&proc->asts_spin); 5126 list_for_each_entry_safe(lkb, safe, &proc->asts, lkb_cb_list) { 5127 memset(&lkb->lkb_callbacks, 0, 5128 sizeof(struct dlm_callback) * DLM_CALLBACKS_SIZE); 5129 list_del_init(&lkb->lkb_cb_list); 5130 dlm_put_lkb(lkb); 5131 } 5132 spin_unlock(&proc->asts_spin); 5133 } 5134 5135 /* pid of 0 means purge all orphans */ 5136 5137 static void do_purge(struct dlm_ls *ls, int nodeid, int pid) 5138 { 5139 struct dlm_lkb *lkb, *safe; 5140 5141 mutex_lock(&ls->ls_orphans_mutex); 5142 list_for_each_entry_safe(lkb, safe, &ls->ls_orphans, lkb_ownqueue) { 5143 if (pid && lkb->lkb_ownpid != pid) 5144 continue; 5145 unlock_proc_lock(ls, lkb); 5146 list_del_init(&lkb->lkb_ownqueue); 5147 dlm_put_lkb(lkb); 5148 } 5149 mutex_unlock(&ls->ls_orphans_mutex); 5150 } 5151 5152 static int send_purge(struct dlm_ls *ls, int nodeid, int pid) 5153 { 5154 struct dlm_message *ms; 5155 struct dlm_mhandle *mh; 5156 int error; 5157 5158 error = _create_message(ls, sizeof(struct dlm_message), nodeid, 5159 DLM_MSG_PURGE, &ms, &mh); 5160 if (error) 5161 return error; 5162 ms->m_nodeid = nodeid; 5163 ms->m_pid = pid; 5164 5165 return send_message(mh, ms); 5166 } 5167 5168 int dlm_user_purge(struct dlm_ls *ls, struct dlm_user_proc *proc, 5169 int nodeid, int pid) 5170 { 5171 int error = 0; 5172 5173 if (nodeid != dlm_our_nodeid()) { 5174 error = send_purge(ls, nodeid, pid); 5175 } else { 5176 dlm_lock_recovery(ls); 5177 if (pid == current->pid) 5178 purge_proc_locks(ls, proc); 5179 else 5180 do_purge(ls, nodeid, pid); 5181 dlm_unlock_recovery(ls); 5182 } 5183 return error; 5184 } 5185 5186