1 /* -*- mode: c; c-basic-offset: 8; -*- 2 * vim: noexpandtab sw=8 ts=8 sts=0: 3 * 4 * dlmast.c 5 * 6 * AST and BAST functionality for local and remote nodes 7 * 8 * Copyright (C) 2004 Oracle. All rights reserved. 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public 12 * License as published by the Free Software Foundation; either 13 * version 2 of the License, or (at your option) any later version. 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 18 * General Public License for more details. 19 * 20 * You should have received a copy of the GNU General Public 21 * License along with this program; if not, write to the 22 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 23 * Boston, MA 021110-1307, USA. 24 * 25 */ 26 27 28 #include <linux/module.h> 29 #include <linux/fs.h> 30 #include <linux/types.h> 31 #include <linux/slab.h> 32 #include <linux/highmem.h> 33 #include <linux/utsname.h> 34 #include <linux/init.h> 35 #include <linux/sysctl.h> 36 #include <linux/random.h> 37 #include <linux/blkdev.h> 38 #include <linux/socket.h> 39 #include <linux/inet.h> 40 #include <linux/spinlock.h> 41 42 43 #include "cluster/heartbeat.h" 44 #include "cluster/nodemanager.h" 45 #include "cluster/tcp.h" 46 47 #include "dlmapi.h" 48 #include "dlmcommon.h" 49 50 #define MLOG_MASK_PREFIX ML_DLM 51 #include "cluster/masklog.h" 52 53 static void dlm_update_lvb(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, 54 struct dlm_lock *lock); 55 static int dlm_should_cancel_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock); 56 57 /* Should be called as an ast gets queued to see if the new 58 * lock level will obsolete a pending bast. 59 * For example, if dlm_thread queued a bast for an EX lock that 60 * was blocking another EX, but before sending the bast the 61 * lock owner downconverted to NL, the bast is now obsolete. 62 * Only the ast should be sent. 63 * This is needed because the lock and convert paths can queue 64 * asts out-of-band (not waiting for dlm_thread) in order to 65 * allow for LKM_NOQUEUE to get immediate responses. */ 66 static int dlm_should_cancel_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock) 67 { 68 assert_spin_locked(&dlm->ast_lock); 69 assert_spin_locked(&lock->spinlock); 70 71 if (lock->ml.highest_blocked == LKM_IVMODE) 72 return 0; 73 BUG_ON(lock->ml.highest_blocked == LKM_NLMODE); 74 75 if (lock->bast_pending && 76 list_empty(&lock->bast_list)) 77 /* old bast already sent, ok */ 78 return 0; 79 80 if (lock->ml.type == LKM_EXMODE) 81 /* EX blocks anything left, any bast still valid */ 82 return 0; 83 else if (lock->ml.type == LKM_NLMODE) 84 /* NL blocks nothing, no reason to send any bast, cancel it */ 85 return 1; 86 else if (lock->ml.highest_blocked != LKM_EXMODE) 87 /* PR only blocks EX */ 88 return 1; 89 90 return 0; 91 } 92 93 static void __dlm_queue_ast(struct dlm_ctxt *dlm, struct dlm_lock *lock) 94 { 95 mlog_entry_void(); 96 97 BUG_ON(!dlm); 98 BUG_ON(!lock); 99 100 assert_spin_locked(&dlm->ast_lock); 101 if (!list_empty(&lock->ast_list)) { 102 mlog(ML_ERROR, "ast list not empty!! pending=%d, newlevel=%d\n", 103 lock->ast_pending, lock->ml.type); 104 BUG(); 105 } 106 BUG_ON(!list_empty(&lock->ast_list)); 107 if (lock->ast_pending) 108 mlog(0, "lock has an ast getting flushed right now\n"); 109 110 /* putting lock on list, add a ref */ 111 dlm_lock_get(lock); 112 spin_lock(&lock->spinlock); 113 114 /* check to see if this ast obsoletes the bast */ 115 if (dlm_should_cancel_bast(dlm, lock)) { 116 struct dlm_lock_resource *res = lock->lockres; 117 mlog(0, "%s: cancelling bast for %.*s\n", 118 dlm->name, res->lockname.len, res->lockname.name); 119 lock->bast_pending = 0; 120 list_del_init(&lock->bast_list); 121 lock->ml.highest_blocked = LKM_IVMODE; 122 /* removing lock from list, remove a ref. guaranteed 123 * this won't be the last ref because of the get above, 124 * so res->spinlock will not be taken here */ 125 dlm_lock_put(lock); 126 /* free up the reserved bast that we are cancelling. 127 * guaranteed that this will not be the last reserved 128 * ast because *both* an ast and a bast were reserved 129 * to get to this point. the res->spinlock will not be 130 * taken here */ 131 dlm_lockres_release_ast(dlm, res); 132 } 133 list_add_tail(&lock->ast_list, &dlm->pending_asts); 134 lock->ast_pending = 1; 135 spin_unlock(&lock->spinlock); 136 } 137 138 void dlm_queue_ast(struct dlm_ctxt *dlm, struct dlm_lock *lock) 139 { 140 mlog_entry_void(); 141 142 BUG_ON(!dlm); 143 BUG_ON(!lock); 144 145 spin_lock(&dlm->ast_lock); 146 __dlm_queue_ast(dlm, lock); 147 spin_unlock(&dlm->ast_lock); 148 } 149 150 151 static void __dlm_queue_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock) 152 { 153 mlog_entry_void(); 154 155 BUG_ON(!dlm); 156 BUG_ON(!lock); 157 assert_spin_locked(&dlm->ast_lock); 158 159 BUG_ON(!list_empty(&lock->bast_list)); 160 if (lock->bast_pending) 161 mlog(0, "lock has a bast getting flushed right now\n"); 162 163 /* putting lock on list, add a ref */ 164 dlm_lock_get(lock); 165 spin_lock(&lock->spinlock); 166 list_add_tail(&lock->bast_list, &dlm->pending_basts); 167 lock->bast_pending = 1; 168 spin_unlock(&lock->spinlock); 169 } 170 171 void dlm_queue_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock) 172 { 173 mlog_entry_void(); 174 175 BUG_ON(!dlm); 176 BUG_ON(!lock); 177 178 spin_lock(&dlm->ast_lock); 179 __dlm_queue_bast(dlm, lock); 180 spin_unlock(&dlm->ast_lock); 181 } 182 183 static void dlm_update_lvb(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, 184 struct dlm_lock *lock) 185 { 186 struct dlm_lockstatus *lksb = lock->lksb; 187 BUG_ON(!lksb); 188 189 /* only updates if this node masters the lockres */ 190 if (res->owner == dlm->node_num) { 191 192 spin_lock(&res->spinlock); 193 /* check the lksb flags for the direction */ 194 if (lksb->flags & DLM_LKSB_GET_LVB) { 195 mlog(0, "getting lvb from lockres for %s node\n", 196 lock->ml.node == dlm->node_num ? "master" : 197 "remote"); 198 memcpy(lksb->lvb, res->lvb, DLM_LVB_LEN); 199 } 200 /* Do nothing for lvb put requests - they should be done in 201 * place when the lock is downconverted - otherwise we risk 202 * racing gets and puts which could result in old lvb data 203 * being propagated. We leave the put flag set and clear it 204 * here. In the future we might want to clear it at the time 205 * the put is actually done. 206 */ 207 spin_unlock(&res->spinlock); 208 } 209 210 /* reset any lvb flags on the lksb */ 211 lksb->flags &= ~(DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB); 212 } 213 214 void dlm_do_local_ast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, 215 struct dlm_lock *lock) 216 { 217 dlm_astlockfunc_t *fn; 218 struct dlm_lockstatus *lksb; 219 220 mlog_entry_void(); 221 222 lksb = lock->lksb; 223 fn = lock->ast; 224 BUG_ON(lock->ml.node != dlm->node_num); 225 226 dlm_update_lvb(dlm, res, lock); 227 (*fn)(lock->astdata); 228 } 229 230 231 int dlm_do_remote_ast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, 232 struct dlm_lock *lock) 233 { 234 int ret; 235 struct dlm_lockstatus *lksb; 236 int lksbflags; 237 238 mlog_entry_void(); 239 240 lksb = lock->lksb; 241 BUG_ON(lock->ml.node == dlm->node_num); 242 243 lksbflags = lksb->flags; 244 dlm_update_lvb(dlm, res, lock); 245 246 /* lock request came from another node 247 * go do the ast over there */ 248 ret = dlm_send_proxy_ast(dlm, res, lock, lksbflags); 249 return ret; 250 } 251 252 void dlm_do_local_bast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, 253 struct dlm_lock *lock, int blocked_type) 254 { 255 dlm_bastlockfunc_t *fn = lock->bast; 256 257 mlog_entry_void(); 258 BUG_ON(lock->ml.node != dlm->node_num); 259 260 (*fn)(lock->astdata, blocked_type); 261 } 262 263 264 265 int dlm_proxy_ast_handler(struct o2net_msg *msg, u32 len, void *data, 266 void **ret_data) 267 { 268 int ret; 269 unsigned int locklen; 270 struct dlm_ctxt *dlm = data; 271 struct dlm_lock_resource *res = NULL; 272 struct dlm_lock *lock = NULL; 273 struct dlm_proxy_ast *past = (struct dlm_proxy_ast *) msg->buf; 274 char *name; 275 struct list_head *iter, *head=NULL; 276 u64 cookie; 277 u32 flags; 278 279 if (!dlm_grab(dlm)) { 280 dlm_error(DLM_REJECTED); 281 return DLM_REJECTED; 282 } 283 284 mlog_bug_on_msg(!dlm_domain_fully_joined(dlm), 285 "Domain %s not fully joined!\n", dlm->name); 286 287 name = past->name; 288 locklen = past->namelen; 289 cookie = be64_to_cpu(past->cookie); 290 flags = be32_to_cpu(past->flags); 291 292 if (locklen > DLM_LOCKID_NAME_MAX) { 293 ret = DLM_IVBUFLEN; 294 mlog(ML_ERROR, "Invalid name length in proxy ast handler!\n"); 295 goto leave; 296 } 297 298 if ((flags & (LKM_PUT_LVB|LKM_GET_LVB)) == 299 (LKM_PUT_LVB|LKM_GET_LVB)) { 300 mlog(ML_ERROR, "both PUT and GET lvb specified\n"); 301 ret = DLM_BADARGS; 302 goto leave; 303 } 304 305 mlog(0, "lvb: %s\n", flags & LKM_PUT_LVB ? "put lvb" : 306 (flags & LKM_GET_LVB ? "get lvb" : "none")); 307 308 mlog(0, "type=%d, blocked_type=%d\n", past->type, past->blocked_type); 309 310 if (past->type != DLM_AST && 311 past->type != DLM_BAST) { 312 mlog(ML_ERROR, "Unknown ast type! %d, cookie=%u:%llu" 313 "name=%.*s\n", past->type, 314 dlm_get_lock_cookie_node(cookie), 315 dlm_get_lock_cookie_seq(cookie), 316 locklen, name); 317 ret = DLM_IVLOCKID; 318 goto leave; 319 } 320 321 res = dlm_lookup_lockres(dlm, name, locklen); 322 if (!res) { 323 mlog(0, "got %sast for unknown lockres! " 324 "cookie=%u:%llu, name=%.*s, namelen=%u\n", 325 past->type == DLM_AST ? "" : "b", 326 dlm_get_lock_cookie_node(cookie), 327 dlm_get_lock_cookie_seq(cookie), 328 locklen, name, locklen); 329 ret = DLM_IVLOCKID; 330 goto leave; 331 } 332 333 /* cannot get a proxy ast message if this node owns it */ 334 BUG_ON(res->owner == dlm->node_num); 335 336 mlog(0, "lockres %.*s\n", res->lockname.len, res->lockname.name); 337 338 spin_lock(&res->spinlock); 339 if (res->state & DLM_LOCK_RES_RECOVERING) { 340 mlog(0, "responding with DLM_RECOVERING!\n"); 341 ret = DLM_RECOVERING; 342 goto unlock_out; 343 } 344 if (res->state & DLM_LOCK_RES_MIGRATING) { 345 mlog(0, "responding with DLM_MIGRATING!\n"); 346 ret = DLM_MIGRATING; 347 goto unlock_out; 348 } 349 /* try convert queue for both ast/bast */ 350 head = &res->converting; 351 lock = NULL; 352 list_for_each(iter, head) { 353 lock = list_entry (iter, struct dlm_lock, list); 354 if (be64_to_cpu(lock->ml.cookie) == cookie) 355 goto do_ast; 356 } 357 358 /* if not on convert, try blocked for ast, granted for bast */ 359 if (past->type == DLM_AST) 360 head = &res->blocked; 361 else 362 head = &res->granted; 363 364 list_for_each(iter, head) { 365 lock = list_entry (iter, struct dlm_lock, list); 366 if (be64_to_cpu(lock->ml.cookie) == cookie) 367 goto do_ast; 368 } 369 370 mlog(0, "got %sast for unknown lock! cookie=%u:%llu, " 371 "name=%.*s, namelen=%u\n", past->type == DLM_AST ? "" : "b", 372 dlm_get_lock_cookie_node(cookie), 373 dlm_get_lock_cookie_seq(cookie), 374 locklen, name, locklen); 375 376 ret = DLM_NORMAL; 377 unlock_out: 378 spin_unlock(&res->spinlock); 379 goto leave; 380 381 do_ast: 382 ret = DLM_NORMAL; 383 if (past->type == DLM_AST) { 384 /* do not alter lock refcount. switching lists. */ 385 list_move_tail(&lock->list, &res->granted); 386 mlog(0, "ast: adding to granted list... type=%d, " 387 "convert_type=%d\n", lock->ml.type, lock->ml.convert_type); 388 if (lock->ml.convert_type != LKM_IVMODE) { 389 lock->ml.type = lock->ml.convert_type; 390 lock->ml.convert_type = LKM_IVMODE; 391 } else { 392 // should already be there.... 393 } 394 395 lock->lksb->status = DLM_NORMAL; 396 397 /* if we requested the lvb, fetch it into our lksb now */ 398 if (flags & LKM_GET_LVB) { 399 BUG_ON(!(lock->lksb->flags & DLM_LKSB_GET_LVB)); 400 memcpy(lock->lksb->lvb, past->lvb, DLM_LVB_LEN); 401 } 402 } 403 spin_unlock(&res->spinlock); 404 405 if (past->type == DLM_AST) 406 dlm_do_local_ast(dlm, res, lock); 407 else 408 dlm_do_local_bast(dlm, res, lock, past->blocked_type); 409 410 leave: 411 412 if (res) 413 dlm_lockres_put(res); 414 415 dlm_put(dlm); 416 return ret; 417 } 418 419 420 421 int dlm_send_proxy_ast_msg(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, 422 struct dlm_lock *lock, int msg_type, 423 int blocked_type, int flags) 424 { 425 int ret = 0; 426 struct dlm_proxy_ast past; 427 struct kvec vec[2]; 428 size_t veclen = 1; 429 int status; 430 431 mlog_entry("res %.*s, to=%u, type=%d, blocked_type=%d\n", 432 res->lockname.len, res->lockname.name, lock->ml.node, 433 msg_type, blocked_type); 434 435 memset(&past, 0, sizeof(struct dlm_proxy_ast)); 436 past.node_idx = dlm->node_num; 437 past.type = msg_type; 438 past.blocked_type = blocked_type; 439 past.namelen = res->lockname.len; 440 memcpy(past.name, res->lockname.name, past.namelen); 441 past.cookie = lock->ml.cookie; 442 443 vec[0].iov_len = sizeof(struct dlm_proxy_ast); 444 vec[0].iov_base = &past; 445 if (flags & DLM_LKSB_GET_LVB) { 446 mlog(0, "returning requested LVB data\n"); 447 be32_add_cpu(&past.flags, LKM_GET_LVB); 448 vec[1].iov_len = DLM_LVB_LEN; 449 vec[1].iov_base = lock->lksb->lvb; 450 veclen++; 451 } 452 453 ret = o2net_send_message_vec(DLM_PROXY_AST_MSG, dlm->key, vec, veclen, 454 lock->ml.node, &status); 455 if (ret < 0) 456 mlog_errno(ret); 457 else { 458 if (status == DLM_RECOVERING) { 459 mlog(ML_ERROR, "sent AST to node %u, it thinks this " 460 "node is dead!\n", lock->ml.node); 461 BUG(); 462 } else if (status == DLM_MIGRATING) { 463 mlog(ML_ERROR, "sent AST to node %u, it returned " 464 "DLM_MIGRATING!\n", lock->ml.node); 465 BUG(); 466 } else if (status != DLM_NORMAL && status != DLM_IVLOCKID) { 467 mlog(ML_ERROR, "AST to node %u returned %d!\n", 468 lock->ml.node, status); 469 /* ignore it */ 470 } 471 ret = 0; 472 } 473 return ret; 474 } 475