lustre/obdclass/llog.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2012, 2015, Intel Corporation.
  27  */
  28 /*
  29  * This file is part of Lustre, http://www.lustre.org/
  30  * Lustre is a trademark of Sun Microsystems, Inc.
  31  *
  32  * lustre/obdclass/llog.c
  33  *
  34  * OST<->MDS recovery logging infrastructure.
  35  * Invariants in implementation:
  36  * - we do not share logs among different OST<->MDS connections, so that
  37  *   if an OST or MDS fails it need only look at log(s) relevant to itself
  38  *
  39  * Author: Andreas Dilger <adilger@clusterfs.com>
  40  * Author: Alex Zhuravlev <bzzz@whamcloud.com>
  41  * Author: Mikhail Pershin <tappro@whamcloud.com>
  42  */
  43
  44 #define DEBUG_SUBSYSTEM S_LOG
  45
  46 #include <linux/kthread.h>
  47 #include <llog_swab.h>
  48 #include <lustre_log.h>
  49 #include <obd_class.h>
  50 #include "llog_internal.h"
  51 /*
  52  * Allocate a new log or catalog handle
  53  * Used inside llog_open().
  54  */
  55 static struct llog_handle *llog_alloc_handle(void)
  56 {
  57         struct llog_handle *loghandle;
  58
  59         OBD_ALLOC_PTR(loghandle);
  60         if (loghandle == NULL)
  61                 return NULL;
  62
  63         init_rwsem(&loghandle->lgh_lock);
  64         mutex_init(&loghandle->lgh_hdr_mutex);
  65         INIT_LIST_HEAD(&loghandle->u.phd.phd_entry);
  66         atomic_set(&loghandle->lgh_refcount, 1);
  67
  68         return loghandle;
  69 }
  70
  71 /*
  72  * Free llog handle and header data if exists. Used in llog_close() only
  73  */
  74 static void llog_free_handle(struct llog_handle *loghandle)
  75 {
  76         LASSERT(loghandle != NULL);
  77
  78         /* failed llog_init_handle */
  79         if (loghandle->lgh_hdr == NULL)
  80                 goto out;
  81
  82         if (loghandle->lgh_hdr->llh_flags & LLOG_F_IS_PLAIN)
  83                 LASSERT(list_empty(&loghandle->u.phd.phd_entry));
  84         else if (loghandle->lgh_hdr->llh_flags & LLOG_F_IS_CAT)
  85                 LASSERT(list_empty(&loghandle->u.chd.chd_head));
  86         OBD_FREE_LARGE(loghandle->lgh_hdr, loghandle->lgh_hdr_size);
  87 out:
  88         OBD_FREE_PTR(loghandle);
  89 }
  90
  91 void llog_handle_get(struct llog_handle *loghandle)
  92 {
  93         atomic_inc(&loghandle->lgh_refcount);
  94 }
  95
  96 void llog_handle_put(struct llog_handle *loghandle)
  97 {
  98         LASSERT(atomic_read(&loghandle->lgh_refcount) > 0);
  99         if (atomic_dec_and_test(&loghandle->lgh_refcount))
 100                 llog_free_handle(loghandle);
 101 }
 102
 103 static int llog_declare_destroy(const struct lu_env *env,
 104                                 struct llog_handle *handle,
 105                                 struct thandle *th)
 106 {
 107         struct llog_operations *lop;
 108         int rc;
 109
 110         ENTRY;
 111
 112         rc = llog_handle2ops(handle, &lop);
 113         if (rc)
 114                 RETURN(rc);
 115         if (lop->lop_declare_destroy == NULL)
 116                 RETURN(-EOPNOTSUPP);
 117
 118         rc = lop->lop_declare_destroy(env, handle, th);
 119
 120         RETURN(rc);
 121 }
 122
 123 int llog_trans_destroy(const struct lu_env *env, struct llog_handle *handle,
 124                        struct thandle *th)
 125 {
 126         struct llog_operations  *lop;
 127         int rc;
 128         ENTRY;
 129
 130         rc = llog_handle2ops(handle, &lop);
 131         if (rc < 0)
 132                 RETURN(rc);
 133         if (lop->lop_destroy == NULL)
 134                 RETURN(-EOPNOTSUPP);
 135
 136         LASSERT(handle->lgh_obj != NULL);
 137         if (!dt_object_exists(handle->lgh_obj))
 138                 RETURN(0);
 139
 140         rc = lop->lop_destroy(env, handle, th);
 141
 142         RETURN(rc);
 143 }
 144
 145 int llog_destroy(const struct lu_env *env, struct llog_handle *handle)
 146 {
 147         struct llog_operations  *lop;
 148         struct dt_device        *dt;
 149         struct thandle          *th;
 150         int rc;
 151
 152         ENTRY;
 153
 154         rc = llog_handle2ops(handle, &lop);
 155         if (rc < 0)
 156                 RETURN(rc);
 157         if (lop->lop_destroy == NULL)
 158                 RETURN(-EOPNOTSUPP);
 159
 160         if (handle->lgh_obj == NULL) {
 161                 /* if lgh_obj == NULL, then it is from client side destroy */
 162                 rc = lop->lop_destroy(env, handle, NULL);
 163                 RETURN(rc);
 164         }
 165
 166         if (!dt_object_exists(handle->lgh_obj))
 167                 RETURN(0);
 168
 169         dt = lu2dt_dev(handle->lgh_obj->do_lu.lo_dev);
 170
 171         th = dt_trans_create(env, dt);
 172         if (IS_ERR(th))
 173                 RETURN(PTR_ERR(th));
 174
 175         rc = llog_declare_destroy(env, handle, th);
 176         if (rc != 0)
 177                 GOTO(out_trans, rc);
 178
 179         rc = dt_trans_start_local(env, dt, th);
 180         if (rc < 0)
 181                 GOTO(out_trans, rc);
 182
 183         rc = lop->lop_destroy(env, handle, th);
 184
 185 out_trans:
 186         dt_trans_stop(env, dt, th);
 187
 188         RETURN(rc);
 189 }
 190 EXPORT_SYMBOL(llog_destroy);
 191
 192 /* returns negative on error; 0 if success; 1 if success & log destroyed */
 193 int llog_cancel_rec(const struct lu_env *env, struct llog_handle *loghandle,
 194                     int index)
 195 {
 196         struct llog_thread_info *lgi = llog_info(env);
 197         struct dt_device        *dt;
 198         struct llog_log_hdr     *llh = loghandle->lgh_hdr;
 199         struct thandle          *th;
 200         int                      rc;
 201         int rc1;
 202         bool subtract_count = false;
 203
 204         ENTRY;
 205
 206         CDEBUG(D_RPCTRACE, "Canceling %d in log "DOSTID"\n", index,
 207                POSTID(&loghandle->lgh_id.lgl_oi));
 208
 209         if (index == 0) {
 210                 CERROR("Can't cancel index 0 which is header\n");
 211                 RETURN(-EINVAL);
 212         }
 213
 214         LASSERT(loghandle != NULL);
 215         LASSERT(loghandle->lgh_ctxt != NULL);
 216         LASSERT(loghandle->lgh_obj != NULL);
 217
 218         dt = lu2dt_dev(loghandle->lgh_obj->do_lu.lo_dev);
 219
 220         th = dt_trans_create(env, dt);
 221         if (IS_ERR(th))
 222                 RETURN(PTR_ERR(th));
 223
 224         rc = llog_declare_write_rec(env, loghandle, &llh->llh_hdr, index, th);
 225         if (rc < 0)
 226                 GOTO(out_trans, rc);
 227
 228         if ((llh->llh_flags & LLOG_F_ZAP_WHEN_EMPTY)) {
 229                 rc = llog_declare_destroy(env, loghandle, th);
 230                 if (rc < 0)
 231                         GOTO(out_trans, rc);
 232         }
 233
 234         th->th_wait_submit = 1;
 235         rc = dt_trans_start_local(env, dt, th);
 236         if (rc < 0)
 237                 GOTO(out_trans, rc);
 238
 239         down_write(&loghandle->lgh_lock);
 240         /* clear bitmap */
 241         mutex_lock(&loghandle->lgh_hdr_mutex);
 242         if (!ext2_clear_bit(index, LLOG_HDR_BITMAP(llh))) {
 243                 CDEBUG(D_RPCTRACE, "Catalog index %u already clear?\n", index);
 244                 GOTO(out_unlock, rc);
 245         }
 246
 247         loghandle->lgh_hdr->llh_count--;
 248         subtract_count = true;
 249         /* Pass this index to llog_osd_write_rec(), which will use the index
 250          * to only update the necesary bitmap. */
 251         lgi->lgi_cookie.lgc_index = index;
 252         /* update header */
 253         rc = llog_write_rec(env, loghandle, &llh->llh_hdr, &lgi->lgi_cookie,
 254                             LLOG_HEADER_IDX, th);
 255         if (rc != 0)
 256                 GOTO(out_unlock, rc);
 257
 258         if ((llh->llh_flags & LLOG_F_ZAP_WHEN_EMPTY) &&
 259             (llh->llh_count == 1) &&
 260             ((loghandle->lgh_last_idx == LLOG_HDR_BITMAP_SIZE(llh) - 1) ||
 261              (loghandle->u.phd.phd_cat_handle != NULL &&
 262               loghandle->u.phd.phd_cat_handle->u.chd.chd_current_log !=
 263                 loghandle))) {
 264                 /* never try to destroy it again */
 265                 llh->llh_flags &= ~LLOG_F_ZAP_WHEN_EMPTY;
 266                 rc = llog_trans_destroy(env, loghandle, th);
 267                 if (rc < 0) {
 268                         /* Sigh, can not destroy the final plain llog, but
 269                          * the bitmap has been clearly, so the record can not
 270                          * be accessed anymore, let's return 0 for now, and
 271                          * the orphan will be handled by LFSCK. */
 272                         CERROR("%s: can't destroy empty llog #"DOSTID
 273                                "#%08x: rc = %d\n",
 274                                loghandle->lgh_ctxt->loc_obd->obd_name,
 275                                POSTID(&loghandle->lgh_id.lgl_oi),
 276                                loghandle->lgh_id.lgl_ogen, rc);
 277                         GOTO(out_unlock, rc);
 278                 }
 279                 rc = LLOG_DEL_PLAIN;
 280         }
 281
 282 out_unlock:
 283         mutex_unlock(&loghandle->lgh_hdr_mutex);
 284         up_write(&loghandle->lgh_lock);
 285 out_trans:
 286         rc1 = dt_trans_stop(env, dt, th);
 287         if (rc == 0)
 288                 rc = rc1;
 289         if (rc < 0 && subtract_count) {
 290                 mutex_lock(&loghandle->lgh_hdr_mutex);
 291                 loghandle->lgh_hdr->llh_count++;
 292                 ext2_set_bit(index, LLOG_HDR_BITMAP(llh));
 293                 mutex_unlock(&loghandle->lgh_hdr_mutex);
 294         }
 295         RETURN(rc);
 296 }
 297
 298 int llog_read_header(const struct lu_env *env, struct llog_handle *handle,
 299                      const struct obd_uuid *uuid)
 300 {
 301         struct llog_operations *lop;
 302         int rc;
 303         ENTRY;
 304
 305         rc = llog_handle2ops(handle, &lop);
 306         if (rc)
 307                 RETURN(rc);
 308
 309         if (lop->lop_read_header == NULL)
 310                 RETURN(-EOPNOTSUPP);
 311
 312         rc = lop->lop_read_header(env, handle);
 313         if (rc == LLOG_EEMPTY) {
 314                 struct llog_log_hdr *llh = handle->lgh_hdr;
 315
 316                 /* lrh_len should be initialized in llog_init_handle */
 317                 handle->lgh_last_idx = 0; /* header is record with index 0 */
 318                 handle->lgh_write_offset = 0;
 319                 llh->llh_count = 1;         /* for the header record */
 320                 llh->llh_hdr.lrh_type = LLOG_HDR_MAGIC;
 321                 LASSERT(handle->lgh_ctxt->loc_chunk_size >=
 322                                                 LLOG_MIN_CHUNK_SIZE);
 323                 llh->llh_hdr.lrh_len = handle->lgh_ctxt->loc_chunk_size;
 324                 llh->llh_hdr.lrh_index = 0;
 325                 llh->llh_timestamp = cfs_time_current_sec();
 326                 if (uuid)
 327                         memcpy(&llh->llh_tgtuuid, uuid,
 328                                sizeof(llh->llh_tgtuuid));
 329                 llh->llh_bitmap_offset = offsetof(typeof(*llh), llh_bitmap);
 330                 /* Since update llog header might also call this function,
 331                  * let's reset the bitmap to 0 here */
 332                 memset(LLOG_HDR_BITMAP(llh), 0, llh->llh_hdr.lrh_len -
 333                                                 llh->llh_bitmap_offset -
 334                                                 sizeof(llh->llh_tail));
 335                 ext2_set_bit(0, LLOG_HDR_BITMAP(llh));
 336                 LLOG_HDR_TAIL(llh)->lrt_len = llh->llh_hdr.lrh_len;
 337                 LLOG_HDR_TAIL(llh)->lrt_index = llh->llh_hdr.lrh_index;
 338                 rc = 0;
 339         }
 340         RETURN(rc);
 341 }
 342 EXPORT_SYMBOL(llog_read_header);
 343
 344 int llog_init_handle(const struct lu_env *env, struct llog_handle *handle,
 345                      int flags, struct obd_uuid *uuid)
 346 {
 347         struct llog_log_hdr     *llh;
 348         enum llog_flag           fmt = flags & LLOG_F_EXT_MASK;
 349         int                      rc;
 350         int                     chunk_size = handle->lgh_ctxt->loc_chunk_size;
 351         ENTRY;
 352
 353         LASSERT(handle->lgh_hdr == NULL);
 354
 355         LASSERT(chunk_size >= LLOG_MIN_CHUNK_SIZE);
 356         OBD_ALLOC_LARGE(llh, chunk_size);
 357         if (llh == NULL)
 358                 RETURN(-ENOMEM);
 359
 360         handle->lgh_hdr = llh;
 361         handle->lgh_hdr_size = chunk_size;
 362         /* first assign flags to use llog_client_ops */
 363         llh->llh_flags = flags;
 364         rc = llog_read_header(env, handle, uuid);
 365         if (rc == 0) {
 366                 if (unlikely((llh->llh_flags & LLOG_F_IS_PLAIN &&
 367                               flags & LLOG_F_IS_CAT) ||
 368                              (llh->llh_flags & LLOG_F_IS_CAT &&
 369                               flags & LLOG_F_IS_PLAIN))) {
 370                         CERROR("%s: llog type is %s but initializing %s\n",
 371                                handle->lgh_ctxt->loc_obd->obd_name,
 372                                llh->llh_flags & LLOG_F_IS_CAT ?
 373                                "catalog" : "plain",
 374                                flags & LLOG_F_IS_CAT ? "catalog" : "plain");
 375                         GOTO(out, rc = -EINVAL);
 376                 } else if (llh->llh_flags &
 377                            (LLOG_F_IS_PLAIN | LLOG_F_IS_CAT)) {
 378                         /*
 379                          * it is possible to open llog without specifying llog
 380                          * type so it is taken from llh_flags
 381                          */
 382                         flags = llh->llh_flags;
 383                 } else {
 384                         /* for some reason the llh_flags has no type set */
 385                         CERROR("llog type is not specified!\n");
 386                         GOTO(out, rc = -EINVAL);
 387                 }
 388                 if (unlikely(uuid &&
 389                              !obd_uuid_equals(uuid, &llh->llh_tgtuuid))) {
 390                         CERROR("%s: llog uuid mismatch: %s/%s\n",
 391                                handle->lgh_ctxt->loc_obd->obd_name,
 392                                (char *)uuid->uuid,
 393                                (char *)llh->llh_tgtuuid.uuid);
 394                         GOTO(out, rc = -EEXIST);
 395                 }
 396         }
 397         if (flags & LLOG_F_IS_CAT) {
 398                 LASSERT(list_empty(&handle->u.chd.chd_head));
 399                 INIT_LIST_HEAD(&handle->u.chd.chd_head);
 400                 llh->llh_size = sizeof(struct llog_logid_rec);
 401                 llh->llh_flags |= LLOG_F_IS_FIXSIZE;
 402         } else if (!(flags & LLOG_F_IS_PLAIN)) {
 403                 CERROR("%s: unknown flags: %#x (expected %#x or %#x)\n",
 404                        handle->lgh_ctxt->loc_obd->obd_name,
 405                        flags, LLOG_F_IS_CAT, LLOG_F_IS_PLAIN);
 406                 rc = -EINVAL;
 407         }
 408         llh->llh_flags |= fmt;
 409 out:
 410         if (rc) {
 411                 OBD_FREE_LARGE(llh, chunk_size);
 412                 handle->lgh_hdr = NULL;
 413         }
 414         RETURN(rc);
 415 }
 416 EXPORT_SYMBOL(llog_init_handle);
 417
 418 static int llog_process_thread(void *arg)
 419 {
 420         struct llog_process_info        *lpi = arg;
 421         struct llog_handle              *loghandle = lpi->lpi_loghandle;
 422         struct llog_log_hdr             *llh = loghandle->lgh_hdr;
 423         struct llog_process_cat_data    *cd  = lpi->lpi_catdata;
 424         char                            *buf;
 425         size_t                           chunk_size;
 426         __u64                            cur_offset, tmp_offset;
 427         int                              rc = 0, index = 1, last_index;
 428         int                              saved_index = 0;
 429         int                              last_called_index = 0;
 430
 431         ENTRY;
 432
 433         if (llh == NULL)
 434                 RETURN(-EINVAL);
 435
 436         cur_offset = chunk_size = llh->llh_hdr.lrh_len;
 437         /* expect chunk_size to be power of two */
 438         LASSERT(is_power_of_2(chunk_size));
 439
 440         OBD_ALLOC_LARGE(buf, chunk_size);
 441         if (buf == NULL) {
 442                 lpi->lpi_rc = -ENOMEM;
 443                 RETURN(0);
 444         }
 445
 446         if (cd != NULL) {
 447                 last_called_index = cd->lpcd_first_idx;
 448                 index = cd->lpcd_first_idx + 1;
 449         }
 450         if (cd != NULL && cd->lpcd_last_idx)
 451                 last_index = cd->lpcd_last_idx;
 452         else
 453                 last_index = LLOG_HDR_BITMAP_SIZE(llh) - 1;
 454
 455         while (rc == 0) {
 456                 struct llog_rec_hdr *rec;
 457                 off_t chunk_offset;
 458                 unsigned int buf_offset = 0;
 459                 bool partial_chunk;
 460
 461                 /* skip records not set in bitmap */
 462                 while (index <= last_index &&
 463                        !ext2_test_bit(index, LLOG_HDR_BITMAP(llh)))
 464                         ++index;
 465
 466                 /* There are no indices prior the last_index */
 467                 if (index > last_index)
 468                         break;
 469
 470                 CDEBUG(D_OTHER, "index: %d last_index %d\n", index,
 471                        last_index);
 472
 473 repeat:
 474                 /* get the buf with our target record; avoid old garbage */
 475                 memset(buf, 0, chunk_size);
 476                 rc = llog_next_block(lpi->lpi_env, loghandle, &saved_index,
 477                                      index, &cur_offset, buf, chunk_size);
 478                 if (rc != 0)
 479                         GOTO(out, rc);
 480
 481                 /* NB: after llog_next_block() call the cur_offset is the
 482                  * offset of the next block after read one.
 483                  * The absolute offset of the current chunk is calculated
 484                  * from cur_offset value and stored in chunk_offset variable.
 485                  */
 486                 tmp_offset = cur_offset;
 487                 if (do_div(tmp_offset, chunk_size) != 0) {
 488                         partial_chunk = true;
 489                         chunk_offset = cur_offset & ~(chunk_size - 1);
 490                 } else {
 491                         partial_chunk = false;
 492                         chunk_offset = cur_offset - chunk_size;
 493                 }
 494
 495                 /* NB: when rec->lrh_len is accessed it is already swabbed
 496                  * since it is used at the "end" of the loop and the rec
 497                  * swabbing is done at the beginning of the loop. */
 498                 for (rec = (struct llog_rec_hdr *)(buf + buf_offset);
 499                      (char *)rec < buf + chunk_size;
 500                      rec = llog_rec_hdr_next(rec)) {
 501
 502                         CDEBUG(D_OTHER, "processing rec 0x%p type %#x\n",
 503                                rec, rec->lrh_type);
 504
 505                         if (LLOG_REC_HDR_NEEDS_SWABBING(rec))
 506                                 lustre_swab_llog_rec(rec);
 507
 508                         CDEBUG(D_OTHER, "after swabbing, type=%#x idx=%d\n",
 509                                rec->lrh_type, rec->lrh_index);
 510
 511                         /* for partial chunk the end of it is zeroed, check
 512                          * for index 0 to distinguish it. */
 513                         if (partial_chunk && rec->lrh_index == 0) {
 514                                 /* concurrent llog_add() might add new records
 515                                  * while llog_processing, check this is not
 516                                  * the case and re-read the current chunk
 517                                  * otherwise. */
 518                                 int records;
 519                                 if (index > loghandle->lgh_last_idx)
 520                                         GOTO(out, rc = 0);
 521                                 /* <2 records means no more records
 522                                  * if the last record we processed was
 523                                  * the final one, then the underlying
 524                                  * object might have been destroyed yet.
 525                                  * we better don't access that.. */
 526                                 mutex_lock(&loghandle->lgh_hdr_mutex);
 527                                 records = loghandle->lgh_hdr->llh_count;
 528                                 mutex_unlock(&loghandle->lgh_hdr_mutex);
 529                                 if (records <= 1)
 530                                         GOTO(out, rc = 0);
 531                                 CDEBUG(D_OTHER, "Re-read last llog buffer for "
 532                                        "new records, index %u, last %u\n",
 533                                        index, loghandle->lgh_last_idx);
 534                                 /* save offset inside buffer for the re-read */
 535                                 buf_offset = (char *)rec - (char *)buf;
 536                                 cur_offset = chunk_offset;
 537                                 goto repeat;
 538                         }
 539
 540                         if (rec->lrh_len == 0 || rec->lrh_len > chunk_size) {
 541                                 CWARN("invalid length %d in llog record for "
 542                                       "index %d/%d\n", rec->lrh_len,
 543                                       rec->lrh_index, index);
 544                                 GOTO(out, rc = -EINVAL);
 545                         }
 546
 547                         if (rec->lrh_index < index) {
 548                                 CDEBUG(D_OTHER, "skipping lrh_index %d\n",
 549                                        rec->lrh_index);
 550                                 continue;
 551                         }
 552
 553                         if (rec->lrh_index != index) {
 554                                 CERROR("%s: Invalid record: index %u but "
 555                                        "expected %u\n",
 556                                        loghandle->lgh_ctxt->loc_obd->obd_name,
 557                                        rec->lrh_index, index);
 558                                 GOTO(out, rc = -ERANGE);
 559                         }
 560
 561                         CDEBUG(D_OTHER,
 562                                "lrh_index: %d lrh_len: %d (%d remains)\n",
 563                                rec->lrh_index, rec->lrh_len,
 564                                (int)(buf + chunk_size - (char *)rec));
 565
 566                         loghandle->lgh_cur_idx = rec->lrh_index;
 567                         loghandle->lgh_cur_offset = (char *)rec - (char *)buf +
 568                                                     chunk_offset;
 569
 570                         /* if set, process the callback on this record */
 571                         if (ext2_test_bit(index, LLOG_HDR_BITMAP(llh))) {
 572                                 rc = lpi->lpi_cb(lpi->lpi_env, loghandle, rec,
 573                                                  lpi->lpi_cbdata);
 574                                 last_called_index = index;
 575                                 if (rc == LLOG_PROC_BREAK) {
 576                                         GOTO(out, rc);
 577                                 } else if (rc == LLOG_DEL_RECORD) {
 578                                         rc = llog_cancel_rec(lpi->lpi_env,
 579                                                              loghandle,
 580                                                              rec->lrh_index);
 581                                 }
 582                                 if (rc)
 583                                         GOTO(out, rc);
 584                         }
 585                         /* exit if the last index is reached */
 586                         if (index >= last_index)
 587                                 GOTO(out, rc = 0);
 588                         ++index;
 589                 }
 590         }
 591
 592 out:
 593         if (cd != NULL)
 594                 cd->lpcd_last_idx = last_called_index;
 595
 596         if (unlikely(rc == -EIO && loghandle->lgh_obj != NULL)) {
 597                 if (dt_object_remote(loghandle->lgh_obj)) {
 598                         /* If it is remote object, then -EIO might means
 599                          * disconnection or eviction, let's return -EAGAIN,
 600                          * so for update recovery log processing, it will
 601                          * retry until the umount or abort recovery, see
 602                          * lod_sub_recovery_thread() */
 603                         CERROR("%s retry remote llog process\n",
 604                                loghandle->lgh_ctxt->loc_obd->obd_name);
 605                         rc = -EAGAIN;
 606                 } else {
 607                         /* something bad happened to the processing of a local
 608                          * llog file, probably I/O error or the log got
 609                          * corrupted to be able to finally release the log we
 610                          * discard any remaining bits in the header */
 611                         CERROR("Local llog found corrupted\n");
 612                         while (index <= last_index) {
 613                                 if (ext2_test_bit(index,
 614                                                   LLOG_HDR_BITMAP(llh)) != 0)
 615                                         llog_cancel_rec(lpi->lpi_env, loghandle,
 616                                                         index);
 617                                 index++;
 618                         }
 619                         rc = 0;
 620                 }
 621         }
 622
 623         OBD_FREE_LARGE(buf, chunk_size);
 624         lpi->lpi_rc = rc;
 625         return 0;
 626 }
 627
 628 static int llog_process_thread_daemonize(void *arg)
 629 {
 630         struct llog_process_info        *lpi = arg;
 631         struct lu_env                    env;
 632         int                              rc;
 633
 634         unshare_fs_struct();
 635
 636         /* client env has no keys, tags is just 0 */
 637         rc = lu_env_init(&env, LCT_LOCAL | LCT_MG_THREAD);
 638         if (rc)
 639                 goto out;
 640         lpi->lpi_env = &env;
 641
 642         rc = llog_process_thread(arg);
 643
 644         lu_env_fini(&env);
 645 out:
 646         complete(&lpi->lpi_completion);
 647         return rc;
 648 }
 649
 650 int llog_process_or_fork(const struct lu_env *env,
 651                          struct llog_handle *loghandle,
 652                          llog_cb_t cb, void *data, void *catdata, bool fork)
 653 {
 654         struct llog_process_info *lpi;
 655         int                      rc;
 656
 657         ENTRY;
 658
 659         OBD_ALLOC_PTR(lpi);
 660         if (lpi == NULL) {
 661                 CERROR("cannot alloc pointer\n");
 662                 RETURN(-ENOMEM);
 663         }
 664         lpi->lpi_loghandle = loghandle;
 665         lpi->lpi_cb        = cb;
 666         lpi->lpi_cbdata    = data;
 667         lpi->lpi_catdata   = catdata;
 668
 669         if (fork) {
 670                 struct task_struct *task;
 671
 672                 /* The new thread can't use parent env,
 673                  * init the new one in llog_process_thread_daemonize. */
 674                 lpi->lpi_env = NULL;
 675                 init_completion(&lpi->lpi_completion);
 676                 task = kthread_run(llog_process_thread_daemonize, lpi,
 677                                    "llog_process_thread");
 678                 if (IS_ERR(task)) {
 679                         rc = PTR_ERR(task);
 680                         CERROR("%s: cannot start thread: rc = %d\n",
 681                                loghandle->lgh_ctxt->loc_obd->obd_name, rc);
 682                         GOTO(out_lpi, rc);
 683                 }
 684                 wait_for_completion(&lpi->lpi_completion);
 685         } else {
 686                 lpi->lpi_env = env;
 687                 llog_process_thread(lpi);
 688         }
 689         rc = lpi->lpi_rc;
 690
 691 out_lpi:
 692         OBD_FREE_PTR(lpi);
 693         RETURN(rc);
 694 }
 695 EXPORT_SYMBOL(llog_process_or_fork);
 696
 697 int llog_process(const struct lu_env *env, struct llog_handle *loghandle,
 698                  llog_cb_t cb, void *data, void *catdata)
 699 {
 700         int rc;
 701         rc = llog_process_or_fork(env, loghandle, cb, data, catdata, true);
 702         return rc == LLOG_DEL_PLAIN ? 0 : rc;
 703 }
 704 EXPORT_SYMBOL(llog_process);
 705
 706 int llog_reverse_process(const struct lu_env *env,
 707                          struct llog_handle *loghandle, llog_cb_t cb,
 708                          void *data, void *catdata)
 709 {
 710         struct llog_log_hdr *llh = loghandle->lgh_hdr;
 711         struct llog_process_cat_data *cd = catdata;
 712         void *buf;
 713         int rc = 0, first_index = 1, index, idx;
 714         __u32   chunk_size = llh->llh_hdr.lrh_len;
 715         ENTRY;
 716
 717         OBD_ALLOC_LARGE(buf, chunk_size);
 718         if (buf == NULL)
 719                 RETURN(-ENOMEM);
 720
 721         if (cd != NULL)
 722                 first_index = cd->lpcd_first_idx + 1;
 723         if (cd != NULL && cd->lpcd_last_idx)
 724                 index = cd->lpcd_last_idx;
 725         else
 726                 index = LLOG_HDR_BITMAP_SIZE(llh) - 1;
 727
 728         while (rc == 0) {
 729                 struct llog_rec_hdr *rec;
 730                 struct llog_rec_tail *tail;
 731
 732                 /* skip records not set in bitmap */
 733                 while (index >= first_index &&
 734                        !ext2_test_bit(index, LLOG_HDR_BITMAP(llh)))
 735                         --index;
 736
 737                 LASSERT(index >= first_index - 1);
 738                 if (index == first_index - 1)
 739                         break;
 740
 741                 /* get the buf with our target record; avoid old garbage */
 742                 memset(buf, 0, chunk_size);
 743                 rc = llog_prev_block(env, loghandle, index, buf, chunk_size);
 744                 if (rc)
 745                         GOTO(out, rc);
 746
 747                 rec = buf;
 748                 idx = rec->lrh_index;
 749                 CDEBUG(D_RPCTRACE, "index %u : idx %u\n", index, idx);
 750                 while (idx < index) {
 751                         rec = (void *)rec + rec->lrh_len;
 752                         if (LLOG_REC_HDR_NEEDS_SWABBING(rec))
 753                                 lustre_swab_llog_rec(rec);
 754                         idx ++;
 755                 }
 756                 LASSERT(idx == index);
 757                 tail = (void *)rec + rec->lrh_len - sizeof(*tail);
 758
 759                 /* process records in buffer, starting where we found one */
 760                 while ((void *)tail > buf) {
 761                         if (tail->lrt_index == 0)
 762                                 GOTO(out, rc = 0); /* no more records */
 763
 764                         /* if set, process the callback on this record */
 765                         if (ext2_test_bit(index, LLOG_HDR_BITMAP(llh))) {
 766                                 rec = (void *)tail - tail->lrt_len +
 767                                       sizeof(*tail);
 768
 769                                 rc = cb(env, loghandle, rec, data);
 770                                 if (rc == LLOG_PROC_BREAK) {
 771                                         GOTO(out, rc);
 772                                 } else if (rc == LLOG_DEL_RECORD) {
 773                                         rc = llog_cancel_rec(env, loghandle,
 774                                                              tail->lrt_index);
 775                                 }
 776                                 if (rc)
 777                                         GOTO(out, rc);
 778                         }
 779
 780                         /* previous record, still in buffer? */
 781                         --index;
 782                         if (index < first_index)
 783                                 GOTO(out, rc = 0);
 784                         tail = (void *)tail - tail->lrt_len;
 785                 }
 786         }
 787
 788 out:
 789         if (buf != NULL)
 790                 OBD_FREE_LARGE(buf, chunk_size);
 791         RETURN(rc);
 792 }
 793 EXPORT_SYMBOL(llog_reverse_process);
 794
 795 /**
 796  * new llog API
 797  *
 798  * API functions:
 799  *      llog_open - open llog, may not exist
 800  *      llog_exist - check if llog exists
 801  *      llog_close - close opened llog, pair for open, frees llog_handle
 802  *      llog_declare_create - declare llog creation
 803  *      llog_create - create new llog on disk, need transaction handle
 804  *      llog_declare_write_rec - declaration of llog write
 805  *      llog_write_rec - write llog record on disk, need transaction handle
 806  *      llog_declare_add - declare llog catalog record addition
 807  *      llog_add - add llog record in catalog, need transaction handle
 808  */
 809 int llog_exist(struct llog_handle *loghandle)
 810 {
 811         struct llog_operations  *lop;
 812         int                      rc;
 813
 814         ENTRY;
 815
 816         rc = llog_handle2ops(loghandle, &lop);
 817         if (rc)
 818                 RETURN(rc);
 819         if (lop->lop_exist == NULL)
 820                 RETURN(-EOPNOTSUPP);
 821
 822         rc = lop->lop_exist(loghandle);
 823         RETURN(rc);
 824 }
 825 EXPORT_SYMBOL(llog_exist);
 826
 827 int llog_declare_create(const struct lu_env *env,
 828                         struct llog_handle *loghandle, struct thandle *th)
 829 {
 830         struct llog_operations  *lop;
 831         int                      raised, rc;
 832
 833         ENTRY;
 834
 835         rc = llog_handle2ops(loghandle, &lop);
 836         if (rc)
 837                 RETURN(rc);
 838         if (lop->lop_declare_create == NULL)
 839                 RETURN(-EOPNOTSUPP);
 840
 841         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 842         if (!raised)
 843                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 844         rc = lop->lop_declare_create(env, loghandle, th);
 845         if (!raised)
 846                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 847         RETURN(rc);
 848 }
 849
 850 int llog_create(const struct lu_env *env, struct llog_handle *handle,
 851                 struct thandle *th)
 852 {
 853         struct llog_operations  *lop;
 854         int                      raised, rc;
 855
 856         ENTRY;
 857
 858         rc = llog_handle2ops(handle, &lop);
 859         if (rc)
 860                 RETURN(rc);
 861         if (lop->lop_create == NULL)
 862                 RETURN(-EOPNOTSUPP);
 863
 864         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 865         if (!raised)
 866                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 867         rc = lop->lop_create(env, handle, th);
 868         if (!raised)
 869                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 870         RETURN(rc);
 871 }
 872
 873 int llog_declare_write_rec(const struct lu_env *env,
 874                            struct llog_handle *handle,
 875                            struct llog_rec_hdr *rec, int idx,
 876                            struct thandle *th)
 877 {
 878         struct llog_operations  *lop;
 879         int                      raised, rc;
 880
 881         ENTRY;
 882
 883         rc = llog_handle2ops(handle, &lop);
 884         if (rc)
 885                 RETURN(rc);
 886         LASSERT(lop);
 887         if (lop->lop_declare_write_rec == NULL)
 888                 RETURN(-EOPNOTSUPP);
 889
 890         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 891         if (!raised)
 892                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 893         rc = lop->lop_declare_write_rec(env, handle, rec, idx, th);
 894         if (!raised)
 895                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 896         RETURN(rc);
 897 }
 898
 899 int llog_write_rec(const struct lu_env *env, struct llog_handle *handle,
 900                    struct llog_rec_hdr *rec, struct llog_cookie *logcookies,
 901                    int idx, struct thandle *th)
 902 {
 903         struct llog_operations  *lop;
 904         int                      raised, rc, buflen;
 905
 906         ENTRY;
 907
 908         /* API sanity checks */
 909         if (handle == NULL) {
 910                 CERROR("loghandle is missed\n");
 911                 RETURN(-EPROTO);
 912         } else if (handle->lgh_obj == NULL) {
 913                 CERROR("loghandle %p with NULL object\n",
 914                         handle);
 915                 RETURN(-EPROTO);
 916         } else if (th == NULL) {
 917                 CERROR("%s: missed transaction handle\n",
 918                         handle->lgh_obj->do_lu.lo_dev->ld_obd->obd_name);
 919                 RETURN(-EPROTO);
 920         } else if (handle->lgh_hdr == NULL) {
 921                 CERROR("%s: loghandle %p with no header\n",
 922                         handle->lgh_obj->do_lu.lo_dev->ld_obd->obd_name,
 923                         handle);
 924                 RETURN(-EPROTO);
 925         }
 926
 927         rc = llog_handle2ops(handle, &lop);
 928         if (rc)
 929                 RETURN(rc);
 930
 931         if (lop->lop_write_rec == NULL)
 932                 RETURN(-EOPNOTSUPP);
 933
 934         buflen = rec->lrh_len;
 935         LASSERT(cfs_size_round(buflen) == buflen);
 936
 937         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 938         if (!raised)
 939                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 940         rc = lop->lop_write_rec(env, handle, rec, logcookies, idx, th);
 941         if (!raised)
 942                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 943         RETURN(rc);
 944 }
 945
 946 int llog_add(const struct lu_env *env, struct llog_handle *lgh,
 947              struct llog_rec_hdr *rec, struct llog_cookie *logcookies,
 948              struct thandle *th)
 949 {
 950         int raised, rc;
 951
 952         ENTRY;
 953
 954         if (lgh->lgh_logops->lop_add == NULL)
 955                 RETURN(-EOPNOTSUPP);
 956
 957         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 958         if (!raised)
 959                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 960         rc = lgh->lgh_logops->lop_add(env, lgh, rec, logcookies, th);
 961         if (!raised)
 962                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 963         RETURN(rc);
 964 }
 965 EXPORT_SYMBOL(llog_add);
 966
 967 int llog_declare_add(const struct lu_env *env, struct llog_handle *lgh,
 968                      struct llog_rec_hdr *rec, struct thandle *th)
 969 {
 970         int raised, rc;
 971
 972         ENTRY;
 973
 974         if (lgh->lgh_logops->lop_declare_add == NULL)
 975                 RETURN(-EOPNOTSUPP);
 976
 977         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 978         if (!raised)
 979                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 980         rc = lgh->lgh_logops->lop_declare_add(env, lgh, rec, th);
 981         if (!raised)
 982                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 983         RETURN(rc);
 984 }
 985 EXPORT_SYMBOL(llog_declare_add);
 986
 987 /**
 988  * Helper function to open llog or create it if doesn't exist.
 989  * It hides all transaction handling from caller.
 990  */
 991 int llog_open_create(const struct lu_env *env, struct llog_ctxt *ctxt,
 992                      struct llog_handle **res, struct llog_logid *logid,
 993                      char *name)
 994 {
 995         struct dt_device        *d;
 996         struct thandle          *th;
 997         int                      rc;
 998
 999         ENTRY;
1000
1001         rc = llog_open(env, ctxt, res, logid, name, LLOG_OPEN_NEW);
1002         if (rc)
1003                 RETURN(rc);
1004
1005         if (llog_exist(*res))
1006                 RETURN(0);
1007
1008         LASSERT((*res)->lgh_obj != NULL);
1009
1010         d = lu2dt_dev((*res)->lgh_obj->do_lu.lo_dev);
1011
1012         th = dt_trans_create(env, d);
1013         if (IS_ERR(th))
1014                 GOTO(out, rc = PTR_ERR(th));
1015
1016         /* Create update llog object synchronously, which
1017          * happens during inialization process see
1018          * lod_sub_prep_llog(), to make sure the update
1019          * llog object is created before corss-MDT writing
1020          * updates into the llog object */
1021         if (ctxt->loc_flags & LLOG_CTXT_FLAG_NORMAL_FID)
1022                 th->th_sync = 1;
1023
1024         th->th_wait_submit = 1;
1025         rc = llog_declare_create(env, *res, th);
1026         if (rc == 0) {
1027                 rc = dt_trans_start_local(env, d, th);
1028                 if (rc == 0)
1029                         rc = llog_create(env, *res, th);
1030         }
1031         dt_trans_stop(env, d, th);
1032 out:
1033         if (rc)
1034                 llog_close(env, *res);
1035         RETURN(rc);
1036 }
1037 EXPORT_SYMBOL(llog_open_create);
1038
1039 /**
1040  * Helper function to delete existent llog.
1041  */
1042 int llog_erase(const struct lu_env *env, struct llog_ctxt *ctxt,
1043                struct llog_logid *logid, char *name)
1044 {
1045         struct llog_handle      *handle;
1046         int                      rc = 0, rc2;
1047
1048         ENTRY;
1049
1050         /* nothing to erase */
1051         if (name == NULL && logid == NULL)
1052                 RETURN(0);
1053
1054         rc = llog_open(env, ctxt, &handle, logid, name, LLOG_OPEN_EXISTS);
1055         if (rc < 0)
1056                 RETURN(rc);
1057
1058         rc = llog_init_handle(env, handle, LLOG_F_IS_PLAIN, NULL);
1059         if (rc == 0)
1060                 rc = llog_destroy(env, handle);
1061
1062         rc2 = llog_close(env, handle);
1063         if (rc == 0)
1064                 rc = rc2;
1065         RETURN(rc);
1066 }
1067 EXPORT_SYMBOL(llog_erase);
1068
1069 /*
1070  * Helper function for write record in llog.
1071  * It hides all transaction handling from caller.
1072  * Valid only with local llog.
1073  */
1074 int llog_write(const struct lu_env *env, struct llog_handle *loghandle,
1075                struct llog_rec_hdr *rec, int idx)
1076 {
1077         struct dt_device        *dt;
1078         struct thandle          *th;
1079         int                      rc;
1080
1081         ENTRY;
1082
1083         LASSERT(loghandle);
1084         LASSERT(loghandle->lgh_ctxt);
1085         LASSERT(loghandle->lgh_obj != NULL);
1086
1087         dt = lu2dt_dev(loghandle->lgh_obj->do_lu.lo_dev);
1088
1089         th = dt_trans_create(env, dt);
1090         if (IS_ERR(th))
1091                 RETURN(PTR_ERR(th));
1092
1093         rc = llog_declare_write_rec(env, loghandle, rec, idx, th);
1094         if (rc)
1095                 GOTO(out_trans, rc);
1096
1097         th->th_wait_submit = 1;
1098         rc = dt_trans_start_local(env, dt, th);
1099         if (rc)
1100                 GOTO(out_trans, rc);
1101
1102         down_write(&loghandle->lgh_lock);
1103         rc = llog_write_rec(env, loghandle, rec, NULL, idx, th);
1104         up_write(&loghandle->lgh_lock);
1105 out_trans:
1106         dt_trans_stop(env, dt, th);
1107         RETURN(rc);
1108 }
1109 EXPORT_SYMBOL(llog_write);
1110
1111 int llog_open(const struct lu_env *env, struct llog_ctxt *ctxt,
1112               struct llog_handle **lgh, struct llog_logid *logid,
1113               char *name, enum llog_open_param open_param)
1114 {
1115         int      raised;
1116         int      rc;
1117
1118         ENTRY;
1119
1120         LASSERT(ctxt);
1121         LASSERT(ctxt->loc_logops);
1122
1123         if (ctxt->loc_logops->lop_open == NULL) {
1124                 *lgh = NULL;
1125                 RETURN(-EOPNOTSUPP);
1126         }
1127
1128         *lgh = llog_alloc_handle();
1129         if (*lgh == NULL)
1130                 RETURN(-ENOMEM);
1131         (*lgh)->lgh_ctxt = ctxt;
1132         (*lgh)->lgh_logops = ctxt->loc_logops;
1133
1134         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
1135         if (!raised)
1136                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
1137         rc = ctxt->loc_logops->lop_open(env, *lgh, logid, name, open_param);
1138         if (!raised)
1139                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
1140         if (rc) {
1141                 llog_free_handle(*lgh);
1142                 *lgh = NULL;
1143         }
1144         RETURN(rc);
1145 }
1146 EXPORT_SYMBOL(llog_open);
1147
1148 int llog_close(const struct lu_env *env, struct llog_handle *loghandle)
1149 {
1150         struct llog_operations  *lop;
1151         int                      rc;
1152
1153         ENTRY;
1154
1155         rc = llog_handle2ops(loghandle, &lop);
1156         if (rc)
1157                 GOTO(out, rc);
1158         if (lop->lop_close == NULL)
1159                 GOTO(out, rc = -EOPNOTSUPP);
1160         rc = lop->lop_close(env, loghandle);
1161 out:
1162         llog_handle_put(loghandle);
1163         RETURN(rc);
1164 }
1165 EXPORT_SYMBOL(llog_close);
1166
1167 /**
1168  * Helper function to get the llog size in records. It is used by MGS
1169  * mostly to check that config llog exists and contains data.
1170  *
1171  * \param[in] env       execution environment
1172  * \param[in] ctxt      llog context
1173  * \param[in] name      llog name
1174  *
1175  * \retval              true if there are records in llog besides a header
1176  * \retval              false on error or llog without records
1177  */
1178 int llog_is_empty(const struct lu_env *env, struct llog_ctxt *ctxt,
1179                   char *name)
1180 {
1181         struct llog_handle      *llh;
1182         int                      rc = 0;
1183
1184         rc = llog_open(env, ctxt, &llh, NULL, name, LLOG_OPEN_EXISTS);
1185         if (rc < 0) {
1186                 if (likely(rc == -ENOENT))
1187                         rc = 0;
1188                 GOTO(out, rc);
1189         }
1190
1191         rc = llog_init_handle(env, llh, LLOG_F_IS_PLAIN, NULL);
1192         if (rc)
1193                 GOTO(out_close, rc);
1194         rc = llog_get_size(llh);
1195
1196 out_close:
1197         llog_close(env, llh);
1198 out:
1199         /* The header is record 1, the llog is still considered as empty
1200          * if there is only header */
1201         return (rc <= 1);
1202 }
1203 EXPORT_SYMBOL(llog_is_empty);
1204
1205 int llog_copy_handler(const struct lu_env *env, struct llog_handle *llh,
1206                       struct llog_rec_hdr *rec, void *data)
1207 {
1208         struct llog_handle      *copy_llh = data;
1209
1210         /* Append all records */
1211         return llog_write(env, copy_llh, rec, LLOG_NEXT_IDX);
1212 }
1213
1214 /* backup plain llog */
1215 int llog_backup(const struct lu_env *env, struct obd_device *obd,
1216                 struct llog_ctxt *ctxt, struct llog_ctxt *bctxt,
1217                 char *name, char *backup)
1218 {
1219         struct llog_handle      *llh, *bllh;
1220         int                      rc;
1221
1222         ENTRY;
1223
1224         /* open original log */
1225         rc = llog_open(env, ctxt, &llh, NULL, name, LLOG_OPEN_EXISTS);
1226         if (rc < 0) {
1227                 /* the -ENOENT case is also reported to the caller
1228                  * but silently so it should handle that if needed.
1229                  */
1230                 if (rc != -ENOENT)
1231                         CERROR("%s: failed to open log %s: rc = %d\n",
1232                                obd->obd_name, name, rc);
1233                 RETURN(rc);
1234         }
1235
1236         rc = llog_init_handle(env, llh, LLOG_F_IS_PLAIN, NULL);
1237         if (rc)
1238                 GOTO(out_close, rc);
1239
1240         /* Make sure there's no old backup log */
1241         rc = llog_erase(env, bctxt, NULL, backup);
1242         if (rc < 0 && rc != -ENOENT)
1243                 GOTO(out_close, rc);
1244
1245         /* open backup log */
1246         rc = llog_open_create(env, bctxt, &bllh, NULL, backup);
1247         if (rc) {
1248                 CERROR("%s: failed to open backup logfile %s: rc = %d\n",
1249                        obd->obd_name, backup, rc);
1250                 GOTO(out_close, rc);
1251         }
1252
1253         /* check that backup llog is not the same object as original one */
1254         if (llh->lgh_obj == bllh->lgh_obj) {
1255                 CERROR("%s: backup llog %s to itself (%s), objects %p/%p\n",
1256                        obd->obd_name, name, backup, llh->lgh_obj,
1257                        bllh->lgh_obj);
1258                 GOTO(out_backup, rc = -EEXIST);
1259         }
1260
1261         rc = llog_init_handle(env, bllh, LLOG_F_IS_PLAIN, NULL);
1262         if (rc)
1263                 GOTO(out_backup, rc);
1264
1265         /* Copy log record by record */
1266         rc = llog_process_or_fork(env, llh, llog_copy_handler, (void *)bllh,
1267                                   NULL, false);
1268         if (rc)
1269                 CERROR("%s: failed to backup log %s: rc = %d\n",
1270                        obd->obd_name, name, rc);
1271 out_backup:
1272         llog_close(env, bllh);
1273 out_close:
1274         llog_close(env, llh);
1275         RETURN(rc);
1276 }
1277 EXPORT_SYMBOL(llog_backup);
1278
1279 /* Get size of llog */
1280 __u64 llog_size(const struct lu_env *env, struct llog_handle *llh)
1281 {
1282         int rc;
1283         struct lu_attr la;
1284
1285         rc = llh->lgh_obj->do_ops->do_attr_get(env, llh->lgh_obj, &la);
1286         if (rc) {
1287                 CERROR("%s: attr_get failed, rc = %d\n",
1288                        llh->lgh_ctxt->loc_obd->obd_name, rc);
1289                 return 0;
1290         }
1291
1292         return la.la_size;
1293 }
1294 EXPORT_SYMBOL(llog_size);
1295