linux/fs/ocfs2/dlm/dlmconvert.c
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   1/* -*- mode: c; c-basic-offset: 8; -*-
   2 * vim: noexpandtab sw=8 ts=8 sts=0:
   3 *
   4 * dlmconvert.c
   5 *
   6 * underlying calls for lock conversion
   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/highmem.h>
  32#include <linux/init.h>
  33#include <linux/sysctl.h>
  34#include <linux/random.h>
  35#include <linux/blkdev.h>
  36#include <linux/socket.h>
  37#include <linux/inet.h>
  38#include <linux/spinlock.h>
  39
  40
  41#include "cluster/heartbeat.h"
  42#include "cluster/nodemanager.h"
  43#include "cluster/tcp.h"
  44
  45#include "dlmapi.h"
  46#include "dlmcommon.h"
  47
  48#include "dlmconvert.h"
  49
  50#define MLOG_MASK_PREFIX ML_DLM
  51#include "cluster/masklog.h"
  52
  53/* NOTE: __dlmconvert_master is the only function in here that
  54 * needs a spinlock held on entry (res->spinlock) and it is the
  55 * only one that holds a lock on exit (res->spinlock).
  56 * All other functions in here need no locks and drop all of
  57 * the locks that they acquire. */
  58static enum dlm_status __dlmconvert_master(struct dlm_ctxt *dlm,
  59                                           struct dlm_lock_resource *res,
  60                                           struct dlm_lock *lock, int flags,
  61                                           int type, int *call_ast,
  62                                           int *kick_thread);
  63static enum dlm_status dlm_send_remote_convert_request(struct dlm_ctxt *dlm,
  64                                           struct dlm_lock_resource *res,
  65                                           struct dlm_lock *lock, int flags, int type);
  66
  67/*
  68 * this is only called directly by dlmlock(), and only when the
  69 * local node is the owner of the lockres
  70 * locking:
  71 *   caller needs:  none
  72 *   taken:         takes and drops res->spinlock
  73 *   held on exit:  none
  74 * returns: see __dlmconvert_master
  75 */
  76enum dlm_status dlmconvert_master(struct dlm_ctxt *dlm,
  77                                  struct dlm_lock_resource *res,
  78                                  struct dlm_lock *lock, int flags, int type)
  79{
  80        int call_ast = 0, kick_thread = 0;
  81        enum dlm_status status;
  82
  83        spin_lock(&res->spinlock);
  84        /* we are not in a network handler, this is fine */
  85        __dlm_wait_on_lockres(res);
  86        __dlm_lockres_reserve_ast(res);
  87        res->state |= DLM_LOCK_RES_IN_PROGRESS;
  88
  89        status = __dlmconvert_master(dlm, res, lock, flags, type,
  90                                     &call_ast, &kick_thread);
  91
  92        res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
  93        spin_unlock(&res->spinlock);
  94        wake_up(&res->wq);
  95        if (status != DLM_NORMAL && status != DLM_NOTQUEUED)
  96                dlm_error(status);
  97
  98        /* either queue the ast or release it */
  99        if (call_ast)
 100                dlm_queue_ast(dlm, lock);
 101        else
 102                dlm_lockres_release_ast(dlm, res);
 103
 104        if (kick_thread)
 105                dlm_kick_thread(dlm, res);
 106
 107        return status;
 108}
 109
 110/* performs lock conversion at the lockres master site
 111 * locking:
 112 *   caller needs:  res->spinlock
 113 *   taken:         takes and drops lock->spinlock
 114 *   held on exit:  res->spinlock
 115 * returns: DLM_NORMAL, DLM_NOTQUEUED, DLM_DENIED
 116 *   call_ast: whether ast should be called for this lock
 117 *   kick_thread: whether dlm_kick_thread should be called
 118 */
 119static enum dlm_status __dlmconvert_master(struct dlm_ctxt *dlm,
 120                                           struct dlm_lock_resource *res,
 121                                           struct dlm_lock *lock, int flags,
 122                                           int type, int *call_ast,
 123                                           int *kick_thread)
 124{
 125        enum dlm_status status = DLM_NORMAL;
 126        struct dlm_lock *tmplock=NULL;
 127
 128        assert_spin_locked(&res->spinlock);
 129
 130        mlog(0, "type=%d, convert_type=%d, new convert_type=%d\n",
 131             lock->ml.type, lock->ml.convert_type, type);
 132
 133        spin_lock(&lock->spinlock);
 134
 135        /* already converting? */
 136        if (lock->ml.convert_type != LKM_IVMODE) {
 137                mlog(ML_ERROR, "attempted to convert a lock with a lock "
 138                     "conversion pending\n");
 139                status = DLM_DENIED;
 140                goto unlock_exit;
 141        }
 142
 143        /* must be on grant queue to convert */
 144        if (!dlm_lock_on_list(&res->granted, lock)) {
 145                mlog(ML_ERROR, "attempted to convert a lock not on grant "
 146                     "queue\n");
 147                status = DLM_DENIED;
 148                goto unlock_exit;
 149        }
 150
 151        if (flags & LKM_VALBLK) {
 152                switch (lock->ml.type) {
 153                        case LKM_EXMODE:
 154                                /* EX + LKM_VALBLK + convert == set lvb */
 155                                mlog(0, "will set lvb: converting %s->%s\n",
 156                                     dlm_lock_mode_name(lock->ml.type),
 157                                     dlm_lock_mode_name(type));
 158                                lock->lksb->flags |= DLM_LKSB_PUT_LVB;
 159                                break;
 160                        case LKM_PRMODE:
 161                        case LKM_NLMODE:
 162                                /* refetch if new level is not NL */
 163                                if (type > LKM_NLMODE) {
 164                                        mlog(0, "will fetch new value into "
 165                                             "lvb: converting %s->%s\n",
 166                                             dlm_lock_mode_name(lock->ml.type),
 167                                             dlm_lock_mode_name(type));
 168                                        lock->lksb->flags |= DLM_LKSB_GET_LVB;
 169                                } else {
 170                                        mlog(0, "will NOT fetch new value "
 171                                             "into lvb: converting %s->%s\n",
 172                                             dlm_lock_mode_name(lock->ml.type),
 173                                             dlm_lock_mode_name(type));
 174                                        flags &= ~(LKM_VALBLK);
 175                                }
 176                                break;
 177                }
 178        }
 179
 180
 181        /* in-place downconvert? */
 182        if (type <= lock->ml.type)
 183                goto grant;
 184
 185        /* upconvert from here on */
 186        status = DLM_NORMAL;
 187        list_for_each_entry(tmplock, &res->granted, list) {
 188                if (tmplock == lock)
 189                        continue;
 190                if (!dlm_lock_compatible(tmplock->ml.type, type))
 191                        goto switch_queues;
 192        }
 193
 194        list_for_each_entry(tmplock, &res->converting, list) {
 195                if (!dlm_lock_compatible(tmplock->ml.type, type))
 196                        goto switch_queues;
 197                /* existing conversion requests take precedence */
 198                if (!dlm_lock_compatible(tmplock->ml.convert_type, type))
 199                        goto switch_queues;
 200        }
 201
 202        /* fall thru to grant */
 203
 204grant:
 205        mlog(0, "res %.*s, granting %s lock\n", res->lockname.len,
 206             res->lockname.name, dlm_lock_mode_name(type));
 207        /* immediately grant the new lock type */
 208        lock->lksb->status = DLM_NORMAL;
 209        if (lock->ml.node == dlm->node_num)
 210                mlog(0, "doing in-place convert for nonlocal lock\n");
 211        lock->ml.type = type;
 212        if (lock->lksb->flags & DLM_LKSB_PUT_LVB)
 213                memcpy(res->lvb, lock->lksb->lvb, DLM_LVB_LEN);
 214
 215        /*
 216         * Move the lock to the tail because it may be the only lock which has
 217         * an invalid lvb.
 218         */
 219        list_move_tail(&lock->list, &res->granted);
 220
 221        status = DLM_NORMAL;
 222        *call_ast = 1;
 223        goto unlock_exit;
 224
 225switch_queues:
 226        if (flags & LKM_NOQUEUE) {
 227                mlog(0, "failed to convert NOQUEUE lock %.*s from "
 228                     "%d to %d...\n", res->lockname.len, res->lockname.name,
 229                     lock->ml.type, type);
 230                status = DLM_NOTQUEUED;
 231                goto unlock_exit;
 232        }
 233        mlog(0, "res %.*s, queueing...\n", res->lockname.len,
 234             res->lockname.name);
 235
 236        lock->ml.convert_type = type;
 237        /* do not alter lock refcount.  switching lists. */
 238        list_move_tail(&lock->list, &res->converting);
 239
 240unlock_exit:
 241        spin_unlock(&lock->spinlock);
 242        if (status == DLM_DENIED) {
 243                __dlm_print_one_lock_resource(res);
 244        }
 245        if (status == DLM_NORMAL)
 246                *kick_thread = 1;
 247        return status;
 248}
 249
 250void dlm_revert_pending_convert(struct dlm_lock_resource *res,
 251                                struct dlm_lock *lock)
 252{
 253        /* do not alter lock refcount.  switching lists. */
 254        list_move_tail(&lock->list, &res->granted);
 255        lock->ml.convert_type = LKM_IVMODE;
 256        lock->lksb->flags &= ~(DLM_LKSB_GET_LVB|DLM_LKSB_PUT_LVB);
 257}
 258
 259/* messages the master site to do lock conversion
 260 * locking:
 261 *   caller needs:  none
 262 *   taken:         takes and drops res->spinlock, uses DLM_LOCK_RES_IN_PROGRESS
 263 *   held on exit:  none
 264 * returns: DLM_NORMAL, DLM_RECOVERING, status from remote node
 265 */
 266enum dlm_status dlmconvert_remote(struct dlm_ctxt *dlm,
 267                                  struct dlm_lock_resource *res,
 268                                  struct dlm_lock *lock, int flags, int type)
 269{
 270        enum dlm_status status;
 271
 272        mlog(0, "type=%d, convert_type=%d, busy=%d\n", lock->ml.type,
 273             lock->ml.convert_type, res->state & DLM_LOCK_RES_IN_PROGRESS);
 274
 275        spin_lock(&res->spinlock);
 276        if (res->state & DLM_LOCK_RES_RECOVERING) {
 277                mlog(0, "bailing out early since res is RECOVERING "
 278                     "on secondary queue\n");
 279                /* __dlm_print_one_lock_resource(res); */
 280                status = DLM_RECOVERING;
 281                goto bail;
 282        }
 283        /* will exit this call with spinlock held */
 284        __dlm_wait_on_lockres(res);
 285
 286        if (lock->ml.convert_type != LKM_IVMODE) {
 287                __dlm_print_one_lock_resource(res);
 288                mlog(ML_ERROR, "converting a remote lock that is already "
 289                     "converting! (cookie=%u:%llu, conv=%d)\n",
 290                     dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
 291                     dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
 292                     lock->ml.convert_type);
 293                status = DLM_DENIED;
 294                goto bail;
 295        }
 296
 297        if (lock->ml.type == type && lock->ml.convert_type == LKM_IVMODE) {
 298                mlog(0, "last convert request returned DLM_RECOVERING, but "
 299                     "owner has already queued and sent ast to me. res %.*s, "
 300                     "(cookie=%u:%llu, type=%d, conv=%d)\n",
 301                     res->lockname.len, res->lockname.name,
 302                     dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
 303                     dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
 304                     lock->ml.type, lock->ml.convert_type);
 305                status = DLM_NORMAL;
 306                goto bail;
 307        }
 308
 309        res->state |= DLM_LOCK_RES_IN_PROGRESS;
 310        /* move lock to local convert queue */
 311        /* do not alter lock refcount.  switching lists. */
 312        list_move_tail(&lock->list, &res->converting);
 313        lock->convert_pending = 1;
 314        lock->ml.convert_type = type;
 315
 316        if (flags & LKM_VALBLK) {
 317                if (lock->ml.type == LKM_EXMODE) {
 318                        flags |= LKM_PUT_LVB;
 319                        lock->lksb->flags |= DLM_LKSB_PUT_LVB;
 320                } else {
 321                        if (lock->ml.convert_type == LKM_NLMODE)
 322                                flags &= ~LKM_VALBLK;
 323                        else {
 324                                flags |= LKM_GET_LVB;
 325                                lock->lksb->flags |= DLM_LKSB_GET_LVB;
 326                        }
 327                }
 328        }
 329        spin_unlock(&res->spinlock);
 330
 331        /* no locks held here.
 332         * need to wait for a reply as to whether it got queued or not. */
 333        status = dlm_send_remote_convert_request(dlm, res, lock, flags, type);
 334
 335        spin_lock(&res->spinlock);
 336        res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
 337        /* if it failed, move it back to granted queue.
 338         * if master returns DLM_NORMAL and then down before sending ast,
 339         * it may have already been moved to granted queue, reset to
 340         * DLM_RECOVERING and retry convert */
 341        if (status != DLM_NORMAL) {
 342                if (status != DLM_NOTQUEUED)
 343                        dlm_error(status);
 344                dlm_revert_pending_convert(res, lock);
 345        } else if (!lock->convert_pending) {
 346                mlog(0, "%s: res %.*s, owner died and lock has been moved back "
 347                                "to granted list, retry convert.\n",
 348                                dlm->name, res->lockname.len, res->lockname.name);
 349                status = DLM_RECOVERING;
 350        }
 351
 352        lock->convert_pending = 0;
 353bail:
 354        spin_unlock(&res->spinlock);
 355
 356        /* TODO: should this be a wake_one? */
 357        /* wake up any IN_PROGRESS waiters */
 358        wake_up(&res->wq);
 359
 360        return status;
 361}
 362
 363/* sends DLM_CONVERT_LOCK_MSG to master site
 364 * locking:
 365 *   caller needs:  none
 366 *   taken:         none
 367 *   held on exit:  none
 368 * returns: DLM_NOLOCKMGR, status from remote node
 369 */
 370static enum dlm_status dlm_send_remote_convert_request(struct dlm_ctxt *dlm,
 371                                           struct dlm_lock_resource *res,
 372                                           struct dlm_lock *lock, int flags, int type)
 373{
 374        struct dlm_convert_lock convert;
 375        int tmpret;
 376        enum dlm_status ret;
 377        int status = 0;
 378        struct kvec vec[2];
 379        size_t veclen = 1;
 380
 381        mlog(0, "%.*s\n", res->lockname.len, res->lockname.name);
 382
 383        memset(&convert, 0, sizeof(struct dlm_convert_lock));
 384        convert.node_idx = dlm->node_num;
 385        convert.requested_type = type;
 386        convert.cookie = lock->ml.cookie;
 387        convert.namelen = res->lockname.len;
 388        convert.flags = cpu_to_be32(flags);
 389        memcpy(convert.name, res->lockname.name, convert.namelen);
 390
 391        vec[0].iov_len = sizeof(struct dlm_convert_lock);
 392        vec[0].iov_base = &convert;
 393
 394        if (flags & LKM_PUT_LVB) {
 395                /* extra data to send if we are updating lvb */
 396                vec[1].iov_len = DLM_LVB_LEN;
 397                vec[1].iov_base = lock->lksb->lvb;
 398                veclen++;
 399        }
 400
 401        tmpret = o2net_send_message_vec(DLM_CONVERT_LOCK_MSG, dlm->key,
 402                                        vec, veclen, res->owner, &status);
 403        if (tmpret >= 0) {
 404                // successfully sent and received
 405                ret = status;  // this is already a dlm_status
 406                if (ret == DLM_RECOVERING) {
 407                        mlog(0, "node %u returned DLM_RECOVERING from convert "
 408                             "message!\n", res->owner);
 409                } else if (ret == DLM_MIGRATING) {
 410                        mlog(0, "node %u returned DLM_MIGRATING from convert "
 411                             "message!\n", res->owner);
 412                } else if (ret == DLM_FORWARD) {
 413                        mlog(0, "node %u returned DLM_FORWARD from convert "
 414                             "message!\n", res->owner);
 415                } else if (ret != DLM_NORMAL && ret != DLM_NOTQUEUED)
 416                        dlm_error(ret);
 417        } else {
 418                mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
 419                     "node %u\n", tmpret, DLM_CONVERT_LOCK_MSG, dlm->key,
 420                     res->owner);
 421                if (dlm_is_host_down(tmpret)) {
 422                        /* instead of logging the same network error over
 423                         * and over, sleep here and wait for the heartbeat
 424                         * to notice the node is dead.  times out after 5s. */
 425                        dlm_wait_for_node_death(dlm, res->owner,
 426                                                DLM_NODE_DEATH_WAIT_MAX);
 427                        ret = DLM_RECOVERING;
 428                        mlog(0, "node %u died so returning DLM_RECOVERING "
 429                             "from convert message!\n", res->owner);
 430                } else {
 431                        ret = dlm_err_to_dlm_status(tmpret);
 432                }
 433        }
 434
 435        return ret;
 436}
 437
 438/* handler for DLM_CONVERT_LOCK_MSG on master site
 439 * locking:
 440 *   caller needs:  none
 441 *   taken:         takes and drop res->spinlock
 442 *   held on exit:  none
 443 * returns: DLM_NORMAL, DLM_IVLOCKID, DLM_BADARGS,
 444 *          status from __dlmconvert_master
 445 */
 446int dlm_convert_lock_handler(struct o2net_msg *msg, u32 len, void *data,
 447                             void **ret_data)
 448{
 449        struct dlm_ctxt *dlm = data;
 450        struct dlm_convert_lock *cnv = (struct dlm_convert_lock *)msg->buf;
 451        struct dlm_lock_resource *res = NULL;
 452        struct dlm_lock *lock = NULL;
 453        struct dlm_lock *tmp_lock;
 454        struct dlm_lockstatus *lksb;
 455        enum dlm_status status = DLM_NORMAL;
 456        u32 flags;
 457        int call_ast = 0, kick_thread = 0, ast_reserved = 0, wake = 0;
 458
 459        if (!dlm_grab(dlm)) {
 460                dlm_error(DLM_REJECTED);
 461                return DLM_REJECTED;
 462        }
 463
 464        mlog_bug_on_msg(!dlm_domain_fully_joined(dlm),
 465                        "Domain %s not fully joined!\n", dlm->name);
 466
 467        if (cnv->namelen > DLM_LOCKID_NAME_MAX) {
 468                status = DLM_IVBUFLEN;
 469                dlm_error(status);
 470                goto leave;
 471        }
 472
 473        flags = be32_to_cpu(cnv->flags);
 474
 475        if ((flags & (LKM_PUT_LVB|LKM_GET_LVB)) ==
 476             (LKM_PUT_LVB|LKM_GET_LVB)) {
 477                mlog(ML_ERROR, "both PUT and GET lvb specified\n");
 478                status = DLM_BADARGS;
 479                goto leave;
 480        }
 481
 482        mlog(0, "lvb: %s\n", flags & LKM_PUT_LVB ? "put lvb" :
 483             (flags & LKM_GET_LVB ? "get lvb" : "none"));
 484
 485        status = DLM_IVLOCKID;
 486        res = dlm_lookup_lockres(dlm, cnv->name, cnv->namelen);
 487        if (!res) {
 488                dlm_error(status);
 489                goto leave;
 490        }
 491
 492        spin_lock(&res->spinlock);
 493        status = __dlm_lockres_state_to_status(res);
 494        if (status != DLM_NORMAL) {
 495                spin_unlock(&res->spinlock);
 496                dlm_error(status);
 497                goto leave;
 498        }
 499        list_for_each_entry(tmp_lock, &res->granted, list) {
 500                if (tmp_lock->ml.cookie == cnv->cookie &&
 501                    tmp_lock->ml.node == cnv->node_idx) {
 502                        lock = tmp_lock;
 503                        dlm_lock_get(lock);
 504                        break;
 505                }
 506        }
 507        spin_unlock(&res->spinlock);
 508        if (!lock) {
 509                status = DLM_IVLOCKID;
 510                mlog(ML_ERROR, "did not find lock to convert on grant queue! "
 511                               "cookie=%u:%llu\n",
 512                     dlm_get_lock_cookie_node(be64_to_cpu(cnv->cookie)),
 513                     dlm_get_lock_cookie_seq(be64_to_cpu(cnv->cookie)));
 514                dlm_print_one_lock_resource(res);
 515                goto leave;
 516        }
 517
 518        /* found the lock */
 519        lksb = lock->lksb;
 520
 521        /* see if caller needed to get/put lvb */
 522        if (flags & LKM_PUT_LVB) {
 523                BUG_ON(lksb->flags & (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
 524                lksb->flags |= DLM_LKSB_PUT_LVB;
 525                memcpy(&lksb->lvb[0], &cnv->lvb[0], DLM_LVB_LEN);
 526        } else if (flags & LKM_GET_LVB) {
 527                BUG_ON(lksb->flags & (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
 528                lksb->flags |= DLM_LKSB_GET_LVB;
 529        }
 530
 531        spin_lock(&res->spinlock);
 532        status = __dlm_lockres_state_to_status(res);
 533        if (status == DLM_NORMAL) {
 534                __dlm_lockres_reserve_ast(res);
 535                ast_reserved = 1;
 536                res->state |= DLM_LOCK_RES_IN_PROGRESS;
 537                status = __dlmconvert_master(dlm, res, lock, flags,
 538                                             cnv->requested_type,
 539                                             &call_ast, &kick_thread);
 540                res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
 541                wake = 1;
 542        }
 543        spin_unlock(&res->spinlock);
 544        if (wake)
 545                wake_up(&res->wq);
 546
 547        if (status != DLM_NORMAL) {
 548                if (status != DLM_NOTQUEUED)
 549                        dlm_error(status);
 550                lksb->flags &= ~(DLM_LKSB_GET_LVB|DLM_LKSB_PUT_LVB);
 551        }
 552
 553leave:
 554        if (lock)
 555                dlm_lock_put(lock);
 556
 557        /* either queue the ast or release it, if reserved */
 558        if (call_ast)
 559                dlm_queue_ast(dlm, lock);
 560        else if (ast_reserved)
 561                dlm_lockres_release_ast(dlm, res);
 562
 563        if (kick_thread)
 564                dlm_kick_thread(dlm, res);
 565
 566        if (res)
 567                dlm_lockres_put(res);
 568
 569        dlm_put(dlm);
 570
 571        return status;
 572}
 573