fs/ocfs2/dlm/dlmast.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* -*- mode: c; c-basic-offset: 8; -*-
   3  * vim: noexpandtab sw=8 ts=8 sts=0:
   4  *
   5  * dlmast.c
   6  *
   7  * AST and BAST functionality for local and remote nodes
   8  *
   9  * Copyright (C) 2004 Oracle.  All rights reserved.
  10  */
  11
  12
  13 #include <linux/module.h>
  14 #include <linux/fs.h>
  15 #include <linux/types.h>
  16 #include <linux/highmem.h>
  17 #include <linux/init.h>
  18 #include <linux/sysctl.h>
  19 #include <linux/random.h>
  20 #include <linux/blkdev.h>
  21 #include <linux/socket.h>
  22 #include <linux/inet.h>
  23 #include <linux/spinlock.h>
  24
  25
  26 #include "../cluster/heartbeat.h"
  27 #include "../cluster/nodemanager.h"
  28 #include "../cluster/tcp.h"
  29
  30 #include "dlmapi.h"
  31 #include "dlmcommon.h"
  32
  33 #define MLOG_MASK_PREFIX ML_DLM
  34 #include "../cluster/masklog.h"
  35
  36 static void dlm_update_lvb(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
  37                            struct dlm_lock *lock);
  38 static int dlm_should_cancel_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock);
  39
  40 /* Should be called as an ast gets queued to see if the new
  41  * lock level will obsolete a pending bast.
  42  * For example, if dlm_thread queued a bast for an EX lock that
  43  * was blocking another EX, but before sending the bast the
  44  * lock owner downconverted to NL, the bast is now obsolete.
  45  * Only the ast should be sent.
  46  * This is needed because the lock and convert paths can queue
  47  * asts out-of-band (not waiting for dlm_thread) in order to
  48  * allow for LKM_NOQUEUE to get immediate responses. */
  49 static int dlm_should_cancel_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock)
  50 {
  51         assert_spin_locked(&dlm->ast_lock);
  52         assert_spin_locked(&lock->spinlock);
  53
  54         if (lock->ml.highest_blocked == LKM_IVMODE)
  55                 return 0;
  56         BUG_ON(lock->ml.highest_blocked == LKM_NLMODE);
  57
  58         if (lock->bast_pending &&
  59             list_empty(&lock->bast_list))
  60                 /* old bast already sent, ok */
  61                 return 0;
  62
  63         if (lock->ml.type == LKM_EXMODE)
  64                 /* EX blocks anything left, any bast still valid */
  65                 return 0;
  66         else if (lock->ml.type == LKM_NLMODE)
  67                 /* NL blocks nothing, no reason to send any bast, cancel it */
  68                 return 1;
  69         else if (lock->ml.highest_blocked != LKM_EXMODE)
  70                 /* PR only blocks EX */
  71                 return 1;
  72
  73         return 0;
  74 }
  75
  76 void __dlm_queue_ast(struct dlm_ctxt *dlm, struct dlm_lock *lock)
  77 {
  78         struct dlm_lock_resource *res;
  79
  80         BUG_ON(!dlm);
  81         BUG_ON(!lock);
  82
  83         res = lock->lockres;
  84
  85         assert_spin_locked(&dlm->ast_lock);
  86
  87         if (!list_empty(&lock->ast_list)) {
  88                 mlog(ML_ERROR, "%s: res %.*s, lock %u:%llu, "
  89                      "AST list not empty, pending %d, newlevel %d\n",
  90                      dlm->name, res->lockname.len, res->lockname.name,
  91                      dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
  92                      dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
  93                      lock->ast_pending, lock->ml.type);
  94                 BUG();
  95         }
  96         if (lock->ast_pending)
  97                 mlog(0, "%s: res %.*s, lock %u:%llu, AST getting flushed\n",
  98                      dlm->name, res->lockname.len, res->lockname.name,
  99                      dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
 100                      dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)));
 101
 102         /* putting lock on list, add a ref */
 103         dlm_lock_get(lock);
 104         spin_lock(&lock->spinlock);
 105
 106         /* check to see if this ast obsoletes the bast */
 107         if (dlm_should_cancel_bast(dlm, lock)) {
 108                 mlog(0, "%s: res %.*s, lock %u:%llu, Cancelling BAST\n",
 109                      dlm->name, res->lockname.len, res->lockname.name,
 110                      dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
 111                      dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)));
 112                 lock->bast_pending = 0;
 113                 list_del_init(&lock->bast_list);
 114                 lock->ml.highest_blocked = LKM_IVMODE;
 115                 /* removing lock from list, remove a ref.  guaranteed
 116                  * this won't be the last ref because of the get above,
 117                  * so res->spinlock will not be taken here */
 118                 dlm_lock_put(lock);
 119                 /* free up the reserved bast that we are cancelling.
 120                  * guaranteed that this will not be the last reserved
 121                  * ast because *both* an ast and a bast were reserved
 122                  * to get to this point.  the res->spinlock will not be
 123                  * taken here */
 124                 dlm_lockres_release_ast(dlm, res);
 125         }
 126         list_add_tail(&lock->ast_list, &dlm->pending_asts);
 127         lock->ast_pending = 1;
 128         spin_unlock(&lock->spinlock);
 129 }
 130
 131 void dlm_queue_ast(struct dlm_ctxt *dlm, struct dlm_lock *lock)
 132 {
 133         BUG_ON(!dlm);
 134         BUG_ON(!lock);
 135
 136         spin_lock(&dlm->ast_lock);
 137         __dlm_queue_ast(dlm, lock);
 138         spin_unlock(&dlm->ast_lock);
 139 }
 140
 141
 142 void __dlm_queue_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock)
 143 {
 144         struct dlm_lock_resource *res;
 145
 146         BUG_ON(!dlm);
 147         BUG_ON(!lock);
 148
 149         assert_spin_locked(&dlm->ast_lock);
 150
 151         res = lock->lockres;
 152
 153         BUG_ON(!list_empty(&lock->bast_list));
 154         if (lock->bast_pending)
 155                 mlog(0, "%s: res %.*s, lock %u:%llu, BAST getting flushed\n",
 156                      dlm->name, res->lockname.len, res->lockname.name,
 157                      dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
 158                      dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)));
 159
 160         /* putting lock on list, add a ref */
 161         dlm_lock_get(lock);
 162         spin_lock(&lock->spinlock);
 163         list_add_tail(&lock->bast_list, &dlm->pending_basts);
 164         lock->bast_pending = 1;
 165         spin_unlock(&lock->spinlock);
 166 }
 167
 168 void dlm_queue_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock)
 169 {
 170         BUG_ON(!dlm);
 171         BUG_ON(!lock);
 172
 173         spin_lock(&dlm->ast_lock);
 174         __dlm_queue_bast(dlm, lock);
 175         spin_unlock(&dlm->ast_lock);
 176 }
 177
 178 static void dlm_update_lvb(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
 179                            struct dlm_lock *lock)
 180 {
 181         struct dlm_lockstatus *lksb = lock->lksb;
 182         BUG_ON(!lksb);
 183
 184         /* only updates if this node masters the lockres */
 185         spin_lock(&res->spinlock);
 186         if (res->owner == dlm->node_num) {
 187                 /* check the lksb flags for the direction */
 188                 if (lksb->flags & DLM_LKSB_GET_LVB) {
 189                         mlog(0, "getting lvb from lockres for %s node\n",
 190                                   lock->ml.node == dlm->node_num ? "master" :
 191                                   "remote");
 192                         memcpy(lksb->lvb, res->lvb, DLM_LVB_LEN);
 193                 }
 194                 /* Do nothing for lvb put requests - they should be done in
 195                  * place when the lock is downconverted - otherwise we risk
 196                  * racing gets and puts which could result in old lvb data
 197                  * being propagated. We leave the put flag set and clear it
 198                  * here. In the future we might want to clear it at the time
 199                  * the put is actually done.
 200                  */
 201         }
 202         spin_unlock(&res->spinlock);
 203
 204         /* reset any lvb flags on the lksb */
 205         lksb->flags &= ~(DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB);
 206 }
 207
 208 void dlm_do_local_ast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
 209                       struct dlm_lock *lock)
 210 {
 211         dlm_astlockfunc_t *fn;
 212
 213         mlog(0, "%s: res %.*s, lock %u:%llu, Local AST\n", dlm->name,
 214              res->lockname.len, res->lockname.name,
 215              dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
 216              dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)));
 217
 218         fn = lock->ast;
 219         BUG_ON(lock->ml.node != dlm->node_num);
 220
 221         dlm_update_lvb(dlm, res, lock);
 222         (*fn)(lock->astdata);
 223 }
 224
 225
 226 int dlm_do_remote_ast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
 227                       struct dlm_lock *lock)
 228 {
 229         int ret;
 230         struct dlm_lockstatus *lksb;
 231         int lksbflags;
 232
 233         mlog(0, "%s: res %.*s, lock %u:%llu, Remote AST\n", dlm->name,
 234              res->lockname.len, res->lockname.name,
 235              dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
 236              dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)));
 237
 238         lksb = lock->lksb;
 239         BUG_ON(lock->ml.node == dlm->node_num);
 240
 241         lksbflags = lksb->flags;
 242         dlm_update_lvb(dlm, res, lock);
 243
 244         /* lock request came from another node
 245          * go do the ast over there */
 246         ret = dlm_send_proxy_ast(dlm, res, lock, lksbflags);
 247         return ret;
 248 }
 249
 250 void dlm_do_local_bast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
 251                        struct dlm_lock *lock, int blocked_type)
 252 {
 253         dlm_bastlockfunc_t *fn = lock->bast;
 254
 255         BUG_ON(lock->ml.node != dlm->node_num);
 256
 257         mlog(0, "%s: res %.*s, lock %u:%llu, Local BAST, blocked %d\n",
 258              dlm->name, res->lockname.len, res->lockname.name,
 259              dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
 260              dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
 261              blocked_type);
 262
 263         (*fn)(lock->astdata, blocked_type);
 264 }
 265
 266
 267
 268 int dlm_proxy_ast_handler(struct o2net_msg *msg, u32 len, void *data,
 269                           void **ret_data)
 270 {
 271         int ret;
 272         unsigned int locklen;
 273         struct dlm_ctxt *dlm = data;
 274         struct dlm_lock_resource *res = NULL;
 275         struct dlm_lock *lock = NULL;
 276         struct dlm_proxy_ast *past = (struct dlm_proxy_ast *) msg->buf;
 277         char *name;
 278         struct list_head *head = NULL;
 279         __be64 cookie;
 280         u32 flags;
 281         u8 node;
 282
 283         if (!dlm_grab(dlm)) {
 284                 dlm_error(DLM_REJECTED);
 285                 return DLM_REJECTED;
 286         }
 287
 288         mlog_bug_on_msg(!dlm_domain_fully_joined(dlm),
 289                         "Domain %s not fully joined!\n", dlm->name);
 290
 291         name = past->name;
 292         locklen = past->namelen;
 293         cookie = past->cookie;
 294         flags = be32_to_cpu(past->flags);
 295         node = past->node_idx;
 296
 297         if (locklen > DLM_LOCKID_NAME_MAX) {
 298                 ret = DLM_IVBUFLEN;
 299                 mlog(ML_ERROR, "Invalid name length (%d) in proxy ast "
 300                      "handler!\n", locklen);
 301                 goto leave;
 302         }
 303
 304         if ((flags & (LKM_PUT_LVB|LKM_GET_LVB)) ==
 305              (LKM_PUT_LVB|LKM_GET_LVB)) {
 306                 mlog(ML_ERROR, "Both PUT and GET lvb specified, (0x%x)\n",
 307                      flags);
 308                 ret = DLM_BADARGS;
 309                 goto leave;
 310         }
 311
 312         mlog(0, "lvb: %s\n", flags & LKM_PUT_LVB ? "put lvb" :
 313                   (flags & LKM_GET_LVB ? "get lvb" : "none"));
 314
 315         mlog(0, "type=%d, blocked_type=%d\n", past->type, past->blocked_type);
 316
 317         if (past->type != DLM_AST &&
 318             past->type != DLM_BAST) {
 319                 mlog(ML_ERROR, "Unknown ast type! %d, cookie=%u:%llu"
 320                      "name=%.*s, node=%u\n", past->type,
 321                      dlm_get_lock_cookie_node(be64_to_cpu(cookie)),
 322                      dlm_get_lock_cookie_seq(be64_to_cpu(cookie)),
 323                      locklen, name, node);
 324                 ret = DLM_IVLOCKID;
 325                 goto leave;
 326         }
 327
 328         res = dlm_lookup_lockres(dlm, name, locklen);
 329         if (!res) {
 330                 mlog(0, "Got %sast for unknown lockres! cookie=%u:%llu, "
 331                      "name=%.*s, node=%u\n", (past->type == DLM_AST ? "" : "b"),
 332                      dlm_get_lock_cookie_node(be64_to_cpu(cookie)),
 333                      dlm_get_lock_cookie_seq(be64_to_cpu(cookie)),
 334                      locklen, name, node);
 335                 ret = DLM_IVLOCKID;
 336                 goto leave;
 337         }
 338
 339         /* cannot get a proxy ast message if this node owns it */
 340         BUG_ON(res->owner == dlm->node_num);
 341
 342         mlog(0, "%s: res %.*s\n", dlm->name, res->lockname.len,
 343              res->lockname.name);
 344
 345         spin_lock(&res->spinlock);
 346         if (res->state & DLM_LOCK_RES_RECOVERING) {
 347                 mlog(0, "Responding with DLM_RECOVERING!\n");
 348                 ret = DLM_RECOVERING;
 349                 goto unlock_out;
 350         }
 351         if (res->state & DLM_LOCK_RES_MIGRATING) {
 352                 mlog(0, "Responding with DLM_MIGRATING!\n");
 353                 ret = DLM_MIGRATING;
 354                 goto unlock_out;
 355         }
 356         /* try convert queue for both ast/bast */
 357         head = &res->converting;
 358         lock = NULL;
 359         list_for_each_entry(lock, head, list) {
 360                 if (lock->ml.cookie == cookie)
 361                         goto do_ast;
 362         }
 363
 364         /* if not on convert, try blocked for ast, granted for bast */
 365         if (past->type == DLM_AST)
 366                 head = &res->blocked;
 367         else
 368                 head = &res->granted;
 369
 370         list_for_each_entry(lock, head, list) {
 371                 /* if lock is found but unlock is pending ignore the bast */
 372                 if (lock->ml.cookie == cookie) {
 373                         if (lock->unlock_pending)
 374                                 break;
 375                         goto do_ast;
 376                 }
 377         }
 378
 379         mlog(0, "Got %sast for unknown lock! cookie=%u:%llu, name=%.*s, "
 380              "node=%u\n", past->type == DLM_AST ? "" : "b",
 381              dlm_get_lock_cookie_node(be64_to_cpu(cookie)),
 382              dlm_get_lock_cookie_seq(be64_to_cpu(cookie)),
 383              locklen, name, node);
 384
 385         ret = DLM_NORMAL;
 386 unlock_out:
 387         spin_unlock(&res->spinlock);
 388         goto leave;
 389
 390 do_ast:
 391         ret = DLM_NORMAL;
 392         if (past->type == DLM_AST) {
 393                 /* do not alter lock refcount.  switching lists. */
 394                 list_move_tail(&lock->list, &res->granted);
 395                 mlog(0, "%s: res %.*s, lock %u:%llu, Granted type %d => %d\n",
 396                      dlm->name, res->lockname.len, res->lockname.name,
 397                      dlm_get_lock_cookie_node(be64_to_cpu(cookie)),
 398                      dlm_get_lock_cookie_seq(be64_to_cpu(cookie)),
 399                      lock->ml.type, lock->ml.convert_type);
 400
 401                 if (lock->ml.convert_type != LKM_IVMODE) {
 402                         lock->ml.type = lock->ml.convert_type;
 403                         lock->ml.convert_type = LKM_IVMODE;
 404                 } else {
 405                         // should already be there....
 406                 }
 407
 408                 lock->lksb->status = DLM_NORMAL;
 409
 410                 /* if we requested the lvb, fetch it into our lksb now */
 411                 if (flags & LKM_GET_LVB) {
 412                         BUG_ON(!(lock->lksb->flags & DLM_LKSB_GET_LVB));
 413                         memcpy(lock->lksb->lvb, past->lvb, DLM_LVB_LEN);
 414                 }
 415         }
 416         spin_unlock(&res->spinlock);
 417
 418         if (past->type == DLM_AST)
 419                 dlm_do_local_ast(dlm, res, lock);
 420         else
 421                 dlm_do_local_bast(dlm, res, lock, past->blocked_type);
 422
 423 leave:
 424         if (res)
 425                 dlm_lockres_put(res);
 426
 427         dlm_put(dlm);
 428         return ret;
 429 }
 430
 431
 432
 433 int dlm_send_proxy_ast_msg(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
 434                            struct dlm_lock *lock, int msg_type,
 435                            int blocked_type, int flags)
 436 {
 437         int ret = 0;
 438         struct dlm_proxy_ast past;
 439         struct kvec vec[2];
 440         size_t veclen = 1;
 441         int status;
 442
 443         mlog(0, "%s: res %.*s, to %u, type %d, blocked_type %d\n", dlm->name,
 444              res->lockname.len, res->lockname.name, lock->ml.node, msg_type,
 445              blocked_type);
 446
 447         memset(&past, 0, sizeof(struct dlm_proxy_ast));
 448         past.node_idx = dlm->node_num;
 449         past.type = msg_type;
 450         past.blocked_type = blocked_type;
 451         past.namelen = res->lockname.len;
 452         memcpy(past.name, res->lockname.name, past.namelen);
 453         past.cookie = lock->ml.cookie;
 454
 455         vec[0].iov_len = sizeof(struct dlm_proxy_ast);
 456         vec[0].iov_base = &past;
 457         if (flags & DLM_LKSB_GET_LVB) {
 458                 be32_add_cpu(&past.flags, LKM_GET_LVB);
 459                 vec[1].iov_len = DLM_LVB_LEN;
 460                 vec[1].iov_base = lock->lksb->lvb;
 461                 veclen++;
 462         }
 463
 464         ret = o2net_send_message_vec(DLM_PROXY_AST_MSG, dlm->key, vec, veclen,
 465                                      lock->ml.node, &status);
 466         if (ret < 0)
 467                 mlog(ML_ERROR, "%s: res %.*s, error %d send AST to node %u\n",
 468                      dlm->name, res->lockname.len, res->lockname.name, ret,
 469                      lock->ml.node);
 470         else {
 471                 if (status == DLM_RECOVERING) {
 472                         mlog(ML_ERROR, "sent AST to node %u, it thinks this "
 473                              "node is dead!\n", lock->ml.node);
 474                         BUG();
 475                 } else if (status == DLM_MIGRATING) {
 476                         mlog(ML_ERROR, "sent AST to node %u, it returned "
 477                              "DLM_MIGRATING!\n", lock->ml.node);
 478                         BUG();
 479                 } else if (status != DLM_NORMAL && status != DLM_IVLOCKID) {
 480                         mlog(ML_ERROR, "AST to node %u returned %d!\n",
 481                              lock->ml.node, status);
 482                         /* ignore it */
 483                 }
 484                 ret = 0;
 485         }
 486         return ret;
 487 }