fs/ocfs2/dlm/dlmast.c

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