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