lustre/ptlrpc/recov_thread.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  *  Copyright (C) 2003 Cluster File Systems, Inc.
   5  *   Author: Andreas Dilger <adilger@clusterfs.com>
   6  *
   7  *   This file is part of Lustre, http://www.lustre.org.
   8  *
   9  *   Lustre is free software; you can redistribute it and/or
  10  *   modify it under the terms of version 2 of the GNU General Public
  11  *   License as published by the Free Software Foundation.
  12  *
  13  *   Lustre is distributed in the hope that it will be useful,
  14  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *   GNU General Public License for more details.
  17  *
  18  *   You should have received a copy of the GNU General Public License
  19  *   along with Lustre; if not, write to the Free Software
  20  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21  *
  22  * OST<->MDS recovery logging thread.
  23  *
  24  * Invariants in implementation:
  25  * - we do not share logs among different OST<->MDS connections, so that
  26  *   if an OST or MDS fails it need only look at log(s) relevant to itself
  27  */
  28
  29 #define DEBUG_SUBSYSTEM S_LOG
  30
  31 #ifndef EXPORT_SYMTAB
  32 # define EXPORT_SYMTAB
  33 #endif
  34
  35 #ifdef __KERNEL__
  36 #include <linux/fs.h>
  37 #else
  38 # include <libcfs/list.h>
  39 # include <liblustre.h>
  40 #endif
  41
  42 #include <libcfs/kp30.h>
  43 #include <linux/obd_class.h>
  44 #include <linux/lustre_commit_confd.h>
  45 #include <linux/obd_support.h>
  46 #include <linux/obd_class.h>
  47 #include <linux/lustre_net.h>
  48 #include <portals/types.h>
  49 #include <libcfs/list.h>
  50 #include <linux/lustre_log.h>
  51 #include "ptlrpc_internal.h"
  52
  53 #define LLCD_SIZE 4096
  54
  55 #ifdef __KERNEL__
  56
  57 static struct llog_commit_master lustre_lcm;
  58 static struct llog_commit_master *lcm = &lustre_lcm;
  59
  60 /* Allocate new commit structs in case we do not have enough */
  61 static int llcd_alloc(void)
  62 {
  63         struct llog_canceld_ctxt *llcd;
  64         int offset = offsetof(struct llog_canceld_ctxt, llcd_cookies);
  65
  66         OBD_ALLOC(llcd, LLCD_SIZE + offset);
  67         if (llcd == NULL)
  68                 return -ENOMEM;
  69
  70         llcd->llcd_lcm = lcm;
  71
  72         spin_lock(&lcm->lcm_llcd_lock);
  73         list_add(&llcd->llcd_list, &lcm->lcm_llcd_free);
  74         atomic_inc(&lcm->lcm_llcd_numfree);
  75         spin_unlock(&lcm->lcm_llcd_lock);
  76
  77         return 0;
  78 }
  79
  80 /* Get a free cookie struct from the list */
  81 struct llog_canceld_ctxt *llcd_grab(void)
  82 {
  83         struct llog_canceld_ctxt *llcd;
  84
  85         spin_lock(&lcm->lcm_llcd_lock);
  86         if (list_empty(&lcm->lcm_llcd_free)) {
  87                 spin_unlock(&lcm->lcm_llcd_lock);
  88                 if (llcd_alloc() < 0) {
  89                         CERROR("unable to allocate log commit data!\n");
  90                         return NULL;
  91                 }
  92                 spin_lock(&lcm->lcm_llcd_lock);
  93         }
  94
  95         llcd = list_entry(lcm->lcm_llcd_free.next, typeof(*llcd), llcd_list);
  96         list_del(&llcd->llcd_list);
  97         atomic_dec(&lcm->lcm_llcd_numfree);
  98         spin_unlock(&lcm->lcm_llcd_lock);
  99
 100         llcd->llcd_tries = 0;
 101         llcd->llcd_cookiebytes = 0;
 102
 103         return llcd;
 104 }
 105 EXPORT_SYMBOL(llcd_grab);
 106
 107 static void llcd_put(struct llog_canceld_ctxt *llcd)
 108 {
 109         int offset = offsetof(struct llog_canceld_ctxt, llcd_cookies);
 110
 111         if (atomic_read(&lcm->lcm_llcd_numfree) >= lcm->lcm_llcd_maxfree) {
 112                 OBD_FREE(llcd, LLCD_SIZE + offset);
 113         } else {
 114                 spin_lock(&lcm->lcm_llcd_lock);
 115                 list_add(&llcd->llcd_list, &lcm->lcm_llcd_free);
 116                 atomic_inc(&lcm->lcm_llcd_numfree);
 117                 spin_unlock(&lcm->lcm_llcd_lock);
 118         }
 119 }
 120
 121 /* Send some cookies to the appropriate target */
 122 void llcd_send(struct llog_canceld_ctxt *llcd)
 123 {
 124         spin_lock(&llcd->llcd_lcm->lcm_llcd_lock);
 125         list_add_tail(&llcd->llcd_list, &llcd->llcd_lcm->lcm_llcd_pending);
 126         spin_unlock(&llcd->llcd_lcm->lcm_llcd_lock);
 127
 128         wake_up_nr(&llcd->llcd_lcm->lcm_waitq, 1);
 129 }
 130 EXPORT_SYMBOL(llcd_send);
 131
 132 /* deleted objects have a commit callback that cancels the MDS
 133  * log record for the deletion.  The commit callback calls this
 134  * function
 135  */
 136 int llog_obd_repl_cancel(struct llog_ctxt *ctxt, int count,
 137                          struct llog_cookie *cookies, int flags, void *data)
 138 {
 139         struct llog_canceld_ctxt *llcd;
 140         int rc = 0;
 141         ENTRY;
 142
 143         LASSERT(ctxt);
 144         down(&ctxt->loc_sem);
 145         if (ctxt->loc_imp == NULL) {
 146                 CWARN("no import for ctxt %p\n", ctxt);
 147                 GOTO(out, rc = 0);
 148         }
 149
 150         llcd = ctxt->loc_llcd;
 151         if (count > 0 && cookies != NULL) {
 152                 if (llcd == NULL) {
 153                         llcd = llcd_grab();
 154                         if (llcd == NULL) {
 155                                 CERROR("couldn't get an llcd - dropped "LPX64":%x+%u\n",
 156                                        cookies->lgc_lgl.lgl_oid,
 157                                        cookies->lgc_lgl.lgl_ogen, cookies->lgc_index);
 158                                 GOTO(out, rc = -ENOMEM);
 159                         }
 160                         llcd->llcd_ctxt = ctxt;
 161                         ctxt->loc_llcd = llcd;
 162                 }
 163                 memcpy((char *)llcd->llcd_cookies + llcd->llcd_cookiebytes,
 164                        cookies, sizeof(*cookies));
 165                 llcd->llcd_cookiebytes += sizeof(*cookies);
 166         } else {
 167                 if (llcd == NULL || !(flags & OBD_LLOG_FL_SENDNOW))
 168                         GOTO(out, rc);
 169         }
 170
 171         if ((LLCD_SIZE - llcd->llcd_cookiebytes < sizeof(*cookies) ||
 172              flags & OBD_LLOG_FL_SENDNOW)) {
 173                 CDEBUG(D_HA, "send llcd %p:%p\n", llcd, llcd->llcd_ctxt);
 174                 ctxt->loc_llcd = NULL;
 175                 llcd_send(llcd);
 176         }
 177 out:
 178         up(&ctxt->loc_sem);
 179         return rc;
 180 }
 181 EXPORT_SYMBOL(llog_obd_repl_cancel);
 182
 183 int llog_obd_repl_sync(struct llog_ctxt *ctxt, struct obd_export *exp)
 184 {
 185         int rc = 0;
 186         ENTRY;
 187
 188         if (exp && (ctxt->loc_imp == exp->exp_imp_reverse)) {
 189                 down(&ctxt->loc_sem);
 190                 if (ctxt->loc_llcd != NULL) {
 191                         llcd_put(ctxt->loc_llcd);
 192                         ctxt->loc_llcd = NULL;
 193                 }
 194                 CWARN("reverse import disconnected, put "
 195                       "llcd %p:%p\n", ctxt->loc_llcd, ctxt);
 196                 ctxt->loc_imp = NULL;
 197                 up(&ctxt->loc_sem);
 198         } else {
 199                 rc = llog_cancel(ctxt, 0, NULL, OBD_LLOG_FL_SENDNOW, NULL);
 200         }
 201
 202         RETURN(rc);
 203 }
 204 EXPORT_SYMBOL(llog_obd_repl_sync);
 205
 206 static int log_commit_thread(void *arg)
 207 {
 208         struct llog_commit_master *lcm = arg;
 209         struct llog_commit_daemon *lcd;
 210         struct llog_canceld_ctxt *llcd, *n;
 211         unsigned long flags;
 212         ENTRY;
 213
 214         OBD_ALLOC(lcd, sizeof(*lcd));
 215         if (lcd == NULL)
 216                 RETURN(-ENOMEM);
 217
 218         lock_kernel();
 219         ptlrpc_daemonize(); /* thread never needs to do IO */
 220
 221         SIGNAL_MASK_LOCK(current, flags);
 222         sigfillset(&current->blocked);
 223         RECALC_SIGPENDING;
 224         SIGNAL_MASK_UNLOCK(current, flags);
 225
 226         spin_lock(&lcm->lcm_thread_lock);
 227
 228         THREAD_NAME(current->comm, sizeof(current->comm) - 1,
 229                     "ll_log_comt_%02d", atomic_read(&lcm->lcm_thread_total));
 230         atomic_inc(&lcm->lcm_thread_total);
 231         spin_unlock(&lcm->lcm_thread_lock);
 232         unlock_kernel();
 233
 234         INIT_LIST_HEAD(&lcd->lcd_lcm_list);
 235         INIT_LIST_HEAD(&lcd->lcd_llcd_list);
 236         lcd->lcd_lcm = lcm;
 237
 238         CDEBUG(D_HA, "%s started\n", current->comm);
 239         do {
 240                 struct ptlrpc_request *request;
 241                 struct obd_import *import = NULL;
 242                 struct list_head *sending_list;
 243                 int rc = 0;
 244
 245                 /* If we do not have enough pages available, allocate some */
 246                 while (atomic_read(&lcm->lcm_llcd_numfree) <
 247                        lcm->lcm_llcd_minfree) {
 248                         if (llcd_alloc() < 0)
 249                                 break;
 250                 }
 251
 252                 spin_lock(&lcm->lcm_thread_lock);
 253                 atomic_inc(&lcm->lcm_thread_numidle);
 254                 list_move(&lcd->lcd_lcm_list, &lcm->lcm_thread_idle);
 255                 spin_unlock(&lcm->lcm_thread_lock);
 256
 257                 wait_event_interruptible(lcm->lcm_waitq,
 258                                          !list_empty(&lcm->lcm_llcd_pending) ||
 259                                          lcm->lcm_flags & LLOG_LCM_FL_EXIT);
 260
 261                 /* If we are the last available thread, start a new one in case
 262                  * we get blocked on an RPC (nobody else will start a new one)*/
 263                 spin_lock(&lcm->lcm_thread_lock);
 264                 atomic_dec(&lcm->lcm_thread_numidle);
 265                 list_move(&lcd->lcd_lcm_list, &lcm->lcm_thread_busy);
 266                 spin_unlock(&lcm->lcm_thread_lock);
 267
 268                 sending_list = &lcm->lcm_llcd_pending;
 269         resend:
 270                 if (lcm->lcm_flags & LLOG_LCM_FL_EXIT) {
 271                         lcm->lcm_llcd_maxfree = 0;
 272                         lcm->lcm_llcd_minfree = 0;
 273                         lcm->lcm_thread_max = 0;
 274
 275                         if (list_empty(&lcm->lcm_llcd_pending) ||
 276                             lcm->lcm_flags & LLOG_LCM_FL_EXIT_FORCE)
 277                                 break;
 278                 }
 279
 280                 if (atomic_read(&lcm->lcm_thread_numidle) <= 1 &&
 281                     atomic_read(&lcm->lcm_thread_total) < lcm->lcm_thread_max) {
 282                         rc = llog_start_commit_thread();
 283                         if (rc < 0)
 284                                 CERROR("error starting thread: rc %d\n", rc);
 285                 }
 286
 287                 /* Move all of the pending cancels from the same OST off of
 288                  * the list, so we don't get multiple threads blocked and/or
 289                  * doing upcalls on the same OST in case of failure. */
 290                 spin_lock(&lcm->lcm_llcd_lock);
 291                 if (!list_empty(sending_list)) {
 292                         list_move_tail(sending_list->next,
 293                                        &lcd->lcd_llcd_list);
 294                         llcd = list_entry(lcd->lcd_llcd_list.next,
 295                                           typeof(*llcd), llcd_list);
 296                         LASSERT(llcd->llcd_lcm == lcm);
 297                         import = llcd->llcd_ctxt->loc_imp;
 298                 }
 299                 list_for_each_entry_safe(llcd, n, sending_list, llcd_list) {
 300                         LASSERT(llcd->llcd_lcm == lcm);
 301                         if (import == llcd->llcd_ctxt->loc_imp)
 302                                 list_move_tail(&llcd->llcd_list,
 303                                                &lcd->lcd_llcd_list);
 304                 }
 305                 if (sending_list != &lcm->lcm_llcd_resend) {
 306                         list_for_each_entry_safe(llcd, n, &lcm->lcm_llcd_resend,
 307                                                  llcd_list) {
 308                                 LASSERT(llcd->llcd_lcm == lcm);
 309                                 if (import == llcd->llcd_ctxt->loc_imp)
 310                                         list_move_tail(&llcd->llcd_list,
 311                                                        &lcd->lcd_llcd_list);
 312                         }
 313                 }
 314                 spin_unlock(&lcm->lcm_llcd_lock);
 315
 316                 /* We are the only one manipulating our local list - no lock */
 317                 list_for_each_entry_safe(llcd,n, &lcd->lcd_llcd_list,llcd_list){
 318                         char *bufs[1] = {(char *)llcd->llcd_cookies};
 319
 320                         list_del(&llcd->llcd_list);
 321                         if (llcd->llcd_cookiebytes == 0) {
 322                                 CDEBUG(D_HA, "put empty llcd %p:%p\n",
 323                                        llcd, llcd->llcd_ctxt);
 324                                 llcd_put(llcd);
 325                                 continue;
 326                         }
 327
 328                         down(&llcd->llcd_ctxt->loc_sem);
 329                         if (llcd->llcd_ctxt->loc_imp == NULL) {
 330                                 up(&llcd->llcd_ctxt->loc_sem);
 331                                 CWARN("import will be destroyed, put "
 332                                       "llcd %p:%p\n", llcd, llcd->llcd_ctxt);
 333                                 llcd_put(llcd);
 334                                 continue;
 335                         }
 336
 337                         up(&llcd->llcd_ctxt->loc_sem);
 338                         request = ptlrpc_prep_req(import, LUSTRE_LOG_VERSION,
 339                                                   OBD_LOG_CANCEL, 1,
 340                                                   &llcd->llcd_cookiebytes,
 341                                                   bufs);
 342
 343                         if (request == NULL) {
 344                                 rc = -ENOMEM;
 345                                 CERROR("error preparing commit: rc %d\n", rc);
 346
 347                                 spin_lock(&lcm->lcm_llcd_lock);
 348                                 list_splice(&lcd->lcd_llcd_list,
 349                                             &lcm->lcm_llcd_resend);
 350                                 INIT_LIST_HEAD(&lcd->lcd_llcd_list);
 351                                 spin_unlock(&lcm->lcm_llcd_lock);
 352                                 break;
 353                         }
 354
 355                         request->rq_replen = lustre_msg_size(0, NULL);
 356                         down(&llcd->llcd_ctxt->loc_sem);
 357                         if (llcd->llcd_ctxt->loc_imp == NULL) {
 358                                 up(&llcd->llcd_ctxt->loc_sem);
 359                                 CWARN("import will be destroyed, put "
 360                                       "llcd %p:%p\n", llcd, llcd->llcd_ctxt);
 361                                 llcd_put(llcd);
 362                                 ptlrpc_req_finished(request);
 363                                 continue;
 364                         }
 365                         up(&llcd->llcd_ctxt->loc_sem);
 366                         rc = ptlrpc_queue_wait(request);
 367                         ptlrpc_req_finished(request);
 368
 369                         /* If the RPC failed, we put this and the remaining
 370                          * messages onto the resend list for another time. */
 371                         if (rc == 0) {
 372                                 llcd_put(llcd);
 373                                 continue;
 374                         }
 375
 376 #if 0                   /* FIXME just put llcd, not put it on resend list */
 377                         spin_lock(&lcm->lcm_llcd_lock);
 378                         list_splice(&lcd->lcd_llcd_list, &lcm->lcm_llcd_resend);
 379                         if (++llcd->llcd_tries < 5) {
 380                                 CERROR("commit %p failed on attempt %d: rc %d\n",
 381                                        llcd, llcd->llcd_tries, rc);
 382
 383                                 list_add_tail(&llcd->llcd_list,
 384                                               &lcm->lcm_llcd_resend);
 385                                 spin_unlock(&lcm->lcm_llcd_lock);
 386                         } else {
 387                                 spin_unlock(&lcm->lcm_llcd_lock);
 388 #endif
 389                                 CERROR("commit %p:%p drop %d cookies: rc %d\n",
 390                                        llcd, llcd->llcd_ctxt,
 391                                        (int)(llcd->llcd_cookiebytes /
 392                                              sizeof(*llcd->llcd_cookies)), rc);
 393                                 llcd_put(llcd);
 394 #if 0
 395                         }
 396                         break;
 397 #endif
 398                 }
 399
 400                 if (rc == 0) {
 401                         sending_list = &lcm->lcm_llcd_resend;
 402                         if (!list_empty(sending_list))
 403                                 goto resend;
 404                 }
 405         } while(1);
 406
 407         /* If we are force exiting, just drop all of the cookies. */
 408         if (lcm->lcm_flags & LLOG_LCM_FL_EXIT_FORCE) {
 409                 spin_lock(&lcm->lcm_llcd_lock);
 410                 list_splice(&lcm->lcm_llcd_pending, &lcd->lcd_llcd_list);
 411                 list_splice(&lcm->lcm_llcd_resend, &lcd->lcd_llcd_list);
 412                 list_splice(&lcm->lcm_llcd_free, &lcd->lcd_llcd_list);
 413                 spin_unlock(&lcm->lcm_llcd_lock);
 414
 415                 list_for_each_entry_safe(llcd, n, &lcd->lcd_llcd_list,llcd_list)
 416                         llcd_put(llcd);
 417         }
 418
 419         spin_lock(&lcm->lcm_thread_lock);
 420         list_del(&lcd->lcd_lcm_list);
 421         spin_unlock(&lcm->lcm_thread_lock);
 422         OBD_FREE(lcd, sizeof(*lcd));
 423
 424         spin_lock(&lcm->lcm_thread_lock);
 425         atomic_dec(&lcm->lcm_thread_total);
 426         spin_unlock(&lcm->lcm_thread_lock);
 427         wake_up(&lcm->lcm_waitq);
 428
 429         CDEBUG(D_HA, "%s exiting\n", current->comm);
 430         return 0;
 431 }
 432
 433 int llog_start_commit_thread(void)
 434 {
 435         int rc;
 436         ENTRY;
 437
 438         if (atomic_read(&lcm->lcm_thread_total) >= lcm->lcm_thread_max)
 439                 RETURN(0);
 440
 441         rc = kernel_thread(log_commit_thread, lcm, CLONE_VM | CLONE_FILES);
 442         if (rc < 0) {
 443                 CERROR("error starting thread #%d: %d\n",
 444                        atomic_read(&lcm->lcm_thread_total), rc);
 445                 RETURN(rc);
 446         }
 447
 448         RETURN(0);
 449 }
 450 EXPORT_SYMBOL(llog_start_commit_thread);
 451
 452 static struct llog_process_args {
 453         struct semaphore         llpa_sem;
 454         struct llog_ctxt        *llpa_ctxt;
 455         void                    *llpa_cb;
 456         void                    *llpa_arg;
 457 } llpa;
 458
 459 int llog_init_commit_master(void)
 460 {
 461         INIT_LIST_HEAD(&lcm->lcm_thread_busy);
 462         INIT_LIST_HEAD(&lcm->lcm_thread_idle);
 463         spin_lock_init(&lcm->lcm_thread_lock);
 464         atomic_set(&lcm->lcm_thread_numidle, 0);
 465         init_waitqueue_head(&lcm->lcm_waitq);
 466         INIT_LIST_HEAD(&lcm->lcm_llcd_pending);
 467         INIT_LIST_HEAD(&lcm->lcm_llcd_resend);
 468         INIT_LIST_HEAD(&lcm->lcm_llcd_free);
 469         spin_lock_init(&lcm->lcm_llcd_lock);
 470         atomic_set(&lcm->lcm_llcd_numfree, 0);
 471         lcm->lcm_llcd_minfree = 0;
 472         lcm->lcm_thread_max = 5;
 473         /* FIXME initialize semaphore for llog_process_args */
 474         sema_init(&llpa.llpa_sem, 1);
 475         return 0;
 476 }
 477
 478 int llog_cleanup_commit_master(int force)
 479 {
 480         lcm->lcm_flags |= LLOG_LCM_FL_EXIT;
 481         if (force)
 482                 lcm->lcm_flags |= LLOG_LCM_FL_EXIT_FORCE;
 483         wake_up(&lcm->lcm_waitq);
 484
 485         wait_event_interruptible(lcm->lcm_waitq,
 486                                  atomic_read(&lcm->lcm_thread_total) == 0);
 487         return 0;
 488 }
 489 EXPORT_SYMBOL(llog_cleanup_commit_master);
 490
 491 static int log_process_thread(void *args)
 492 {
 493         struct llog_process_args *data = args;
 494         struct llog_ctxt *ctxt = data->llpa_ctxt;
 495         void   *cb = data->llpa_cb;
 496         struct llog_logid logid = *(struct llog_logid *)(data->llpa_arg);
 497         struct llog_handle *llh = NULL;
 498         unsigned long flags;
 499         int rc;
 500         ENTRY;
 501
 502         up(&data->llpa_sem);
 503         lock_kernel();
 504         ptlrpc_daemonize(); /* thread never needs to do IO */
 505
 506         THREAD_NAME(current->comm, sizeof(current->comm) - 1, "llog_process");
 507         SIGNAL_MASK_LOCK(current, flags);
 508         sigfillset(&current->blocked);
 509         RECALC_SIGPENDING;
 510         SIGNAL_MASK_UNLOCK(current, flags);
 511         unlock_kernel();
 512
 513         rc = llog_open(ctxt, &llh, &logid, NULL, 0);
 514         if (rc) {
 515                 CERROR("llog_create failed %d\n", rc);
 516                 RETURN(rc);
 517         }
 518         rc = llog_init_handle(llh, LLOG_F_IS_CAT, NULL);
 519         if (rc) {
 520                 CERROR("llog_init_handle failed %d\n", rc);
 521                 GOTO(out, rc);
 522         }
 523
 524         if (cb) {
 525                 rc = llog_cat_process(llh, (llog_cb_t)cb, NULL);
 526                 if (rc != LLOG_PROC_BREAK)
 527                         CERROR("llog_cat_process failed %d\n", rc);
 528         } else {
 529                 CWARN("no callback function for recovery\n");
 530         }
 531
 532         CDEBUG(D_HA, "send llcd %p:%p forcibly after recovery\n",
 533                ctxt->loc_llcd, ctxt);
 534         llog_sync(ctxt, NULL);
 535 out:
 536         rc = llog_cat_put(llh);
 537         if (rc)
 538                 CERROR("llog_cat_put failed %d\n", rc);
 539
 540         RETURN(rc);
 541 }
 542
 543 static int llog_recovery_generic(struct llog_ctxt *ctxt, void *handle,void *arg)
 544 {
 545         int rc;
 546         ENTRY;
 547
 548         down(&llpa.llpa_sem);
 549         llpa.llpa_ctxt = ctxt;
 550         llpa.llpa_cb = handle;
 551         llpa.llpa_arg = arg;
 552
 553         rc = kernel_thread(log_process_thread, &llpa, CLONE_VM | CLONE_FILES);
 554         if (rc < 0)
 555                 CERROR("error starting log_process_thread: %d\n", rc);
 556         else {
 557                 CDEBUG(D_HA, "log_process_thread: %d\n", rc);
 558                 rc = 0;
 559         }
 560
 561         RETURN(rc);
 562 }
 563
 564 int llog_repl_connect(struct llog_ctxt *ctxt, int count,
 565                       struct llog_logid *logid, struct llog_gen *gen,
 566                       struct obd_uuid *uuid)
 567 {
 568         struct llog_canceld_ctxt *llcd;
 569         int rc;
 570         ENTRY;
 571
 572         /* send back llcd before recovery from llog */
 573         if (ctxt->loc_llcd != NULL) {
 574                 CWARN("llcd %p:%p not empty\n", ctxt->loc_llcd, ctxt);
 575                 llog_sync(ctxt, NULL);
 576         }
 577
 578         down(&ctxt->loc_sem);
 579         ctxt->loc_gen = *gen;
 580         llcd = llcd_grab();
 581         if (llcd == NULL) {
 582                 CERROR("couldn't get an llcd\n");
 583                 up(&ctxt->loc_sem);
 584                 RETURN(-ENOMEM);
 585         }
 586         llcd->llcd_ctxt = ctxt;
 587         ctxt->loc_llcd = llcd;
 588         up(&ctxt->loc_sem);
 589
 590         rc = llog_recovery_generic(ctxt, ctxt->llog_proc_cb, logid);
 591         if (rc != 0)
 592                 CERROR("error recovery process: %d\n", rc);
 593
 594         RETURN(rc);
 595 }
 596 EXPORT_SYMBOL(llog_repl_connect);
 597
 598 #else /* !__KERNEL__ */
 599
 600 int llog_obd_repl_cancel(struct llog_ctxt *ctxt, int count,
 601                          struct llog_cookie *cookies, int flags, void *data)
 602 {
 603         return 0;
 604 }
 605 #endif