fs/ocfs2/dlm/dlmconvert.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  * dlmconvert.c
   6  *
   7  * underlying calls for lock conversion
   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 #include "dlmconvert.h"
  34
  35 #define MLOG_MASK_PREFIX ML_DLM
  36 #include "../cluster/masklog.h"
  37
  38 /* NOTE: __dlmconvert_master is the only function in here that
  39  * needs a spinlock held on entry (res->spinlock) and it is the
  40  * only one that holds a lock on exit (res->spinlock).
  41  * All other functions in here need no locks and drop all of
  42  * the locks that they acquire. */
  43 static enum dlm_status __dlmconvert_master(struct dlm_ctxt *dlm,
  44                                            struct dlm_lock_resource *res,
  45                                            struct dlm_lock *lock, int flags,
  46                                            int type, int *call_ast,
  47                                            int *kick_thread);
  48 static enum dlm_status dlm_send_remote_convert_request(struct dlm_ctxt *dlm,
  49                                            struct dlm_lock_resource *res,
  50                                            struct dlm_lock *lock, int flags, int type);
  51
  52 /*
  53  * this is only called directly by dlmlock(), and only when the
  54  * local node is the owner of the lockres
  55  * locking:
  56  *   caller needs:  none
  57  *   taken:         takes and drops res->spinlock
  58  *   held on exit:  none
  59  * returns: see __dlmconvert_master
  60  */
  61 enum dlm_status dlmconvert_master(struct dlm_ctxt *dlm,
  62                                   struct dlm_lock_resource *res,
  63                                   struct dlm_lock *lock, int flags, int type)
  64 {
  65         int call_ast = 0, kick_thread = 0;
  66         enum dlm_status status;
  67
  68         spin_lock(&res->spinlock);
  69         /* we are not in a network handler, this is fine */
  70         __dlm_wait_on_lockres(res);
  71         __dlm_lockres_reserve_ast(res);
  72         res->state |= DLM_LOCK_RES_IN_PROGRESS;
  73
  74         status = __dlmconvert_master(dlm, res, lock, flags, type,
  75                                      &call_ast, &kick_thread);
  76
  77         res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
  78         spin_unlock(&res->spinlock);
  79         wake_up(&res->wq);
  80         if (status != DLM_NORMAL && status != DLM_NOTQUEUED)
  81                 dlm_error(status);
  82
  83         /* either queue the ast or release it */
  84         if (call_ast)
  85                 dlm_queue_ast(dlm, lock);
  86         else
  87                 dlm_lockres_release_ast(dlm, res);
  88
  89         if (kick_thread)
  90                 dlm_kick_thread(dlm, res);
  91
  92         return status;
  93 }
  94
  95 /* performs lock conversion at the lockres master site
  96  * locking:
  97  *   caller needs:  res->spinlock
  98  *   taken:         takes and drops lock->spinlock
  99  *   held on exit:  res->spinlock
 100  * returns: DLM_NORMAL, DLM_NOTQUEUED, DLM_DENIED
 101  *   call_ast: whether ast should be called for this lock
 102  *   kick_thread: whether dlm_kick_thread should be called
 103  */
 104 static enum dlm_status __dlmconvert_master(struct dlm_ctxt *dlm,
 105                                            struct dlm_lock_resource *res,
 106                                            struct dlm_lock *lock, int flags,
 107                                            int type, int *call_ast,
 108                                            int *kick_thread)
 109 {
 110         enum dlm_status status = DLM_NORMAL;
 111         struct dlm_lock *tmplock=NULL;
 112
 113         assert_spin_locked(&res->spinlock);
 114
 115         mlog(0, "type=%d, convert_type=%d, new convert_type=%d\n",
 116              lock->ml.type, lock->ml.convert_type, type);
 117
 118         spin_lock(&lock->spinlock);
 119
 120         /* already converting? */
 121         if (lock->ml.convert_type != LKM_IVMODE) {
 122                 mlog(ML_ERROR, "attempted to convert a lock with a lock "
 123                      "conversion pending\n");
 124                 status = DLM_DENIED;
 125                 goto unlock_exit;
 126         }
 127
 128         /* must be on grant queue to convert */
 129         if (!dlm_lock_on_list(&res->granted, lock)) {
 130                 mlog(ML_ERROR, "attempted to convert a lock not on grant "
 131                      "queue\n");
 132                 status = DLM_DENIED;
 133                 goto unlock_exit;
 134         }
 135
 136         if (flags & LKM_VALBLK) {
 137                 switch (lock->ml.type) {
 138                         case LKM_EXMODE:
 139                                 /* EX + LKM_VALBLK + convert == set lvb */
 140                                 mlog(0, "will set lvb: converting %s->%s\n",
 141                                      dlm_lock_mode_name(lock->ml.type),
 142                                      dlm_lock_mode_name(type));
 143                                 lock->lksb->flags |= DLM_LKSB_PUT_LVB;
 144                                 break;
 145                         case LKM_PRMODE:
 146                         case LKM_NLMODE:
 147                                 /* refetch if new level is not NL */
 148                                 if (type > LKM_NLMODE) {
 149                                         mlog(0, "will fetch new value into "
 150                                              "lvb: converting %s->%s\n",
 151                                              dlm_lock_mode_name(lock->ml.type),
 152                                              dlm_lock_mode_name(type));
 153                                         lock->lksb->flags |= DLM_LKSB_GET_LVB;
 154                                 } else {
 155                                         mlog(0, "will NOT fetch new value "
 156                                              "into lvb: converting %s->%s\n",
 157                                              dlm_lock_mode_name(lock->ml.type),
 158                                              dlm_lock_mode_name(type));
 159                                         flags &= ~(LKM_VALBLK);
 160                                 }
 161                                 break;
 162                 }
 163         }
 164
 165
 166         /* in-place downconvert? */
 167         if (type <= lock->ml.type)
 168                 goto grant;
 169
 170         /* upconvert from here on */
 171         status = DLM_NORMAL;
 172         list_for_each_entry(tmplock, &res->granted, list) {
 173                 if (tmplock == lock)
 174                         continue;
 175                 if (!dlm_lock_compatible(tmplock->ml.type, type))
 176                         goto switch_queues;
 177         }
 178
 179         list_for_each_entry(tmplock, &res->converting, list) {
 180                 if (!dlm_lock_compatible(tmplock->ml.type, type))
 181                         goto switch_queues;
 182                 /* existing conversion requests take precedence */
 183                 if (!dlm_lock_compatible(tmplock->ml.convert_type, type))
 184                         goto switch_queues;
 185         }
 186
 187         /* fall thru to grant */
 188
 189 grant:
 190         mlog(0, "res %.*s, granting %s lock\n", res->lockname.len,
 191              res->lockname.name, dlm_lock_mode_name(type));
 192         /* immediately grant the new lock type */
 193         lock->lksb->status = DLM_NORMAL;
 194         if (lock->ml.node == dlm->node_num)
 195                 mlog(0, "doing in-place convert for nonlocal lock\n");
 196         lock->ml.type = type;
 197         if (lock->lksb->flags & DLM_LKSB_PUT_LVB)
 198                 memcpy(res->lvb, lock->lksb->lvb, DLM_LVB_LEN);
 199
 200         /*
 201          * Move the lock to the tail because it may be the only lock which has
 202          * an invalid lvb.
 203          */
 204         list_move_tail(&lock->list, &res->granted);
 205
 206         status = DLM_NORMAL;
 207         *call_ast = 1;
 208         goto unlock_exit;
 209
 210 switch_queues:
 211         if (flags & LKM_NOQUEUE) {
 212                 mlog(0, "failed to convert NOQUEUE lock %.*s from "
 213                      "%d to %d...\n", res->lockname.len, res->lockname.name,
 214                      lock->ml.type, type);
 215                 status = DLM_NOTQUEUED;
 216                 goto unlock_exit;
 217         }
 218         mlog(0, "res %.*s, queueing...\n", res->lockname.len,
 219              res->lockname.name);
 220
 221         lock->ml.convert_type = type;
 222         /* do not alter lock refcount.  switching lists. */
 223         list_move_tail(&lock->list, &res->converting);
 224
 225 unlock_exit:
 226         spin_unlock(&lock->spinlock);
 227         if (status == DLM_DENIED) {
 228                 __dlm_print_one_lock_resource(res);
 229         }
 230         if (status == DLM_NORMAL)
 231                 *kick_thread = 1;
 232         return status;
 233 }
 234
 235 void dlm_revert_pending_convert(struct dlm_lock_resource *res,
 236                                 struct dlm_lock *lock)
 237 {
 238         /* do not alter lock refcount.  switching lists. */
 239         list_move_tail(&lock->list, &res->granted);
 240         lock->ml.convert_type = LKM_IVMODE;
 241         lock->lksb->flags &= ~(DLM_LKSB_GET_LVB|DLM_LKSB_PUT_LVB);
 242 }
 243
 244 /* messages the master site to do lock conversion
 245  * locking:
 246  *   caller needs:  none
 247  *   taken:         takes and drops res->spinlock, uses DLM_LOCK_RES_IN_PROGRESS
 248  *   held on exit:  none
 249  * returns: DLM_NORMAL, DLM_RECOVERING, status from remote node
 250  */
 251 enum dlm_status dlmconvert_remote(struct dlm_ctxt *dlm,
 252                                   struct dlm_lock_resource *res,
 253                                   struct dlm_lock *lock, int flags, int type)
 254 {
 255         enum dlm_status status;
 256
 257         mlog(0, "type=%d, convert_type=%d, busy=%d\n", lock->ml.type,
 258              lock->ml.convert_type, res->state & DLM_LOCK_RES_IN_PROGRESS);
 259
 260         spin_lock(&res->spinlock);
 261         if (res->state & DLM_LOCK_RES_RECOVERING) {
 262                 mlog(0, "bailing out early since res is RECOVERING "
 263                      "on secondary queue\n");
 264                 /* __dlm_print_one_lock_resource(res); */
 265                 status = DLM_RECOVERING;
 266                 goto bail;
 267         }
 268         /* will exit this call with spinlock held */
 269         __dlm_wait_on_lockres(res);
 270
 271         if (lock->ml.convert_type != LKM_IVMODE) {
 272                 __dlm_print_one_lock_resource(res);
 273                 mlog(ML_ERROR, "converting a remote lock that is already "
 274                      "converting! (cookie=%u:%llu, conv=%d)\n",
 275                      dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
 276                      dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
 277                      lock->ml.convert_type);
 278                 status = DLM_DENIED;
 279                 goto bail;
 280         }
 281
 282         if (lock->ml.type == type && lock->ml.convert_type == LKM_IVMODE) {
 283                 mlog(0, "last convert request returned DLM_RECOVERING, but "
 284                      "owner has already queued and sent ast to me. res %.*s, "
 285                      "(cookie=%u:%llu, type=%d, conv=%d)\n",
 286                      res->lockname.len, res->lockname.name,
 287                      dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
 288                      dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
 289                      lock->ml.type, lock->ml.convert_type);
 290                 status = DLM_NORMAL;
 291                 goto bail;
 292         }
 293
 294         res->state |= DLM_LOCK_RES_IN_PROGRESS;
 295         /* move lock to local convert queue */
 296         /* do not alter lock refcount.  switching lists. */
 297         list_move_tail(&lock->list, &res->converting);
 298         lock->convert_pending = 1;
 299         lock->ml.convert_type = type;
 300
 301         if (flags & LKM_VALBLK) {
 302                 if (lock->ml.type == LKM_EXMODE) {
 303                         flags |= LKM_PUT_LVB;
 304                         lock->lksb->flags |= DLM_LKSB_PUT_LVB;
 305                 } else {
 306                         if (lock->ml.convert_type == LKM_NLMODE)
 307                                 flags &= ~LKM_VALBLK;
 308                         else {
 309                                 flags |= LKM_GET_LVB;
 310                                 lock->lksb->flags |= DLM_LKSB_GET_LVB;
 311                         }
 312                 }
 313         }
 314         spin_unlock(&res->spinlock);
 315
 316         /* no locks held here.
 317          * need to wait for a reply as to whether it got queued or not. */
 318         status = dlm_send_remote_convert_request(dlm, res, lock, flags, type);
 319
 320         spin_lock(&res->spinlock);
 321         res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
 322         /* if it failed, move it back to granted queue.
 323          * if master returns DLM_NORMAL and then down before sending ast,
 324          * it may have already been moved to granted queue, reset to
 325          * DLM_RECOVERING and retry convert */
 326         if (status != DLM_NORMAL) {
 327                 if (status != DLM_NOTQUEUED)
 328                         dlm_error(status);
 329                 dlm_revert_pending_convert(res, lock);
 330         } else if (!lock->convert_pending) {
 331                 mlog(0, "%s: res %.*s, owner died and lock has been moved back "
 332                                 "to granted list, retry convert.\n",
 333                                 dlm->name, res->lockname.len, res->lockname.name);
 334                 status = DLM_RECOVERING;
 335         }
 336
 337         lock->convert_pending = 0;
 338 bail:
 339         spin_unlock(&res->spinlock);
 340
 341         /* TODO: should this be a wake_one? */
 342         /* wake up any IN_PROGRESS waiters */
 343         wake_up(&res->wq);
 344
 345         return status;
 346 }
 347
 348 /* sends DLM_CONVERT_LOCK_MSG to master site
 349  * locking:
 350  *   caller needs:  none
 351  *   taken:         none
 352  *   held on exit:  none
 353  * returns: DLM_NOLOCKMGR, status from remote node
 354  */
 355 static enum dlm_status dlm_send_remote_convert_request(struct dlm_ctxt *dlm,
 356                                            struct dlm_lock_resource *res,
 357                                            struct dlm_lock *lock, int flags, int type)
 358 {
 359         struct dlm_convert_lock convert;
 360         int tmpret;
 361         enum dlm_status ret;
 362         int status = 0;
 363         struct kvec vec[2];
 364         size_t veclen = 1;
 365
 366         mlog(0, "%.*s\n", res->lockname.len, res->lockname.name);
 367
 368         memset(&convert, 0, sizeof(struct dlm_convert_lock));
 369         convert.node_idx = dlm->node_num;
 370         convert.requested_type = type;
 371         convert.cookie = lock->ml.cookie;
 372         convert.namelen = res->lockname.len;
 373         convert.flags = cpu_to_be32(flags);
 374         memcpy(convert.name, res->lockname.name, convert.namelen);
 375
 376         vec[0].iov_len = sizeof(struct dlm_convert_lock);
 377         vec[0].iov_base = &convert;
 378
 379         if (flags & LKM_PUT_LVB) {
 380                 /* extra data to send if we are updating lvb */
 381                 vec[1].iov_len = DLM_LVB_LEN;
 382                 vec[1].iov_base = lock->lksb->lvb;
 383                 veclen++;
 384         }
 385
 386         tmpret = o2net_send_message_vec(DLM_CONVERT_LOCK_MSG, dlm->key,
 387                                         vec, veclen, res->owner, &status);
 388         if (tmpret >= 0) {
 389                 // successfully sent and received
 390                 ret = status;  // this is already a dlm_status
 391                 if (ret == DLM_RECOVERING) {
 392                         mlog(0, "node %u returned DLM_RECOVERING from convert "
 393                              "message!\n", res->owner);
 394                 } else if (ret == DLM_MIGRATING) {
 395                         mlog(0, "node %u returned DLM_MIGRATING from convert "
 396                              "message!\n", res->owner);
 397                 } else if (ret == DLM_FORWARD) {
 398                         mlog(0, "node %u returned DLM_FORWARD from convert "
 399                              "message!\n", res->owner);
 400                 } else if (ret != DLM_NORMAL && ret != DLM_NOTQUEUED)
 401                         dlm_error(ret);
 402         } else {
 403                 mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
 404                      "node %u\n", tmpret, DLM_CONVERT_LOCK_MSG, dlm->key,
 405                      res->owner);
 406                 if (dlm_is_host_down(tmpret)) {
 407                         /* instead of logging the same network error over
 408                          * and over, sleep here and wait for the heartbeat
 409                          * to notice the node is dead.  times out after 5s. */
 410                         dlm_wait_for_node_death(dlm, res->owner,
 411                                                 DLM_NODE_DEATH_WAIT_MAX);
 412                         ret = DLM_RECOVERING;
 413                         mlog(0, "node %u died so returning DLM_RECOVERING "
 414                              "from convert message!\n", res->owner);
 415                 } else {
 416                         ret = dlm_err_to_dlm_status(tmpret);
 417                 }
 418         }
 419
 420         return ret;
 421 }
 422
 423 /* handler for DLM_CONVERT_LOCK_MSG on master site
 424  * locking:
 425  *   caller needs:  none
 426  *   taken:         takes and drop res->spinlock
 427  *   held on exit:  none
 428  * returns: DLM_NORMAL, DLM_IVLOCKID, DLM_BADARGS,
 429  *          status from __dlmconvert_master
 430  */
 431 int dlm_convert_lock_handler(struct o2net_msg *msg, u32 len, void *data,
 432                              void **ret_data)
 433 {
 434         struct dlm_ctxt *dlm = data;
 435         struct dlm_convert_lock *cnv = (struct dlm_convert_lock *)msg->buf;
 436         struct dlm_lock_resource *res = NULL;
 437         struct dlm_lock *lock = NULL;
 438         struct dlm_lock *tmp_lock;
 439         struct dlm_lockstatus *lksb;
 440         enum dlm_status status = DLM_NORMAL;
 441         u32 flags;
 442         int call_ast = 0, kick_thread = 0, ast_reserved = 0, wake = 0;
 443
 444         if (!dlm_grab(dlm)) {
 445                 dlm_error(DLM_REJECTED);
 446                 return DLM_REJECTED;
 447         }
 448
 449         mlog_bug_on_msg(!dlm_domain_fully_joined(dlm),
 450                         "Domain %s not fully joined!\n", dlm->name);
 451
 452         if (cnv->namelen > DLM_LOCKID_NAME_MAX) {
 453                 status = DLM_IVBUFLEN;
 454                 dlm_error(status);
 455                 goto leave;
 456         }
 457
 458         flags = be32_to_cpu(cnv->flags);
 459
 460         if ((flags & (LKM_PUT_LVB|LKM_GET_LVB)) ==
 461              (LKM_PUT_LVB|LKM_GET_LVB)) {
 462                 mlog(ML_ERROR, "both PUT and GET lvb specified\n");
 463                 status = DLM_BADARGS;
 464                 goto leave;
 465         }
 466
 467         mlog(0, "lvb: %s\n", flags & LKM_PUT_LVB ? "put lvb" :
 468              (flags & LKM_GET_LVB ? "get lvb" : "none"));
 469
 470         status = DLM_IVLOCKID;
 471         res = dlm_lookup_lockres(dlm, cnv->name, cnv->namelen);
 472         if (!res) {
 473                 dlm_error(status);
 474                 goto leave;
 475         }
 476
 477         spin_lock(&res->spinlock);
 478         status = __dlm_lockres_state_to_status(res);
 479         if (status != DLM_NORMAL) {
 480                 spin_unlock(&res->spinlock);
 481                 dlm_error(status);
 482                 goto leave;
 483         }
 484         list_for_each_entry(tmp_lock, &res->granted, list) {
 485                 if (tmp_lock->ml.cookie == cnv->cookie &&
 486                     tmp_lock->ml.node == cnv->node_idx) {
 487                         lock = tmp_lock;
 488                         dlm_lock_get(lock);
 489                         break;
 490                 }
 491         }
 492         spin_unlock(&res->spinlock);
 493         if (!lock) {
 494                 status = DLM_IVLOCKID;
 495                 mlog(ML_ERROR, "did not find lock to convert on grant queue! "
 496                                "cookie=%u:%llu\n",
 497                      dlm_get_lock_cookie_node(be64_to_cpu(cnv->cookie)),
 498                      dlm_get_lock_cookie_seq(be64_to_cpu(cnv->cookie)));
 499                 dlm_print_one_lock_resource(res);
 500                 goto leave;
 501         }
 502
 503         /* found the lock */
 504         lksb = lock->lksb;
 505
 506         /* see if caller needed to get/put lvb */
 507         if (flags & LKM_PUT_LVB) {
 508                 BUG_ON(lksb->flags & (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
 509                 lksb->flags |= DLM_LKSB_PUT_LVB;
 510                 memcpy(&lksb->lvb[0], &cnv->lvb[0], DLM_LVB_LEN);
 511         } else if (flags & LKM_GET_LVB) {
 512                 BUG_ON(lksb->flags & (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
 513                 lksb->flags |= DLM_LKSB_GET_LVB;
 514         }
 515
 516         spin_lock(&res->spinlock);
 517         status = __dlm_lockres_state_to_status(res);
 518         if (status == DLM_NORMAL) {
 519                 __dlm_lockres_reserve_ast(res);
 520                 ast_reserved = 1;
 521                 res->state |= DLM_LOCK_RES_IN_PROGRESS;
 522                 status = __dlmconvert_master(dlm, res, lock, flags,
 523                                              cnv->requested_type,
 524                                              &call_ast, &kick_thread);
 525                 res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
 526                 wake = 1;
 527         }
 528         spin_unlock(&res->spinlock);
 529         if (wake)
 530                 wake_up(&res->wq);
 531
 532         if (status != DLM_NORMAL) {
 533                 if (status != DLM_NOTQUEUED)
 534                         dlm_error(status);
 535                 lksb->flags &= ~(DLM_LKSB_GET_LVB|DLM_LKSB_PUT_LVB);
 536         }
 537
 538 leave:
 539         if (lock)
 540                 dlm_lock_put(lock);
 541
 542         /* either queue the ast or release it, if reserved */
 543         if (call_ast)
 544                 dlm_queue_ast(dlm, lock);
 545         else if (ast_reserved)
 546                 dlm_lockres_release_ast(dlm, res);
 547
 548         if (kick_thread)
 549                 dlm_kick_thread(dlm, res);
 550
 551         if (res)
 552                 dlm_lockres_put(res);
 553
 554         dlm_put(dlm);
 555
 556         return status;
 557 }