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/pid_namespace.h>
  47 #include <linux/kthread.h>
  48 #include <llog_swab.h>
  49 #include <lustre_log.h>
  50 #include <obd_class.h>
  51 #include "llog_internal.h"
  52 /*
  53  * Allocate a new log or catalog handle
  54  * Used inside llog_open().
  55  */
  56 static struct llog_handle *llog_alloc_handle(void)
  57 {
  58         struct llog_handle *loghandle;
  59
  60         OBD_ALLOC_PTR(loghandle);
  61         if (loghandle == NULL)
  62                 return NULL;
  63
  64         init_rwsem(&loghandle->lgh_lock);
  65         mutex_init(&loghandle->lgh_hdr_mutex);
  66         INIT_LIST_HEAD(&loghandle->u.phd.phd_entry);
  67         atomic_set(&loghandle->lgh_refcount, 1);
  68
  69         return loghandle;
  70 }
  71
  72 /*
  73  * Free llog handle and header data if exists. Used in llog_close() only
  74  */
  75 static void llog_free_handle(struct llog_handle *loghandle)
  76 {
  77         LASSERT(loghandle != NULL);
  78
  79         /* failed llog_init_handle */
  80         if (loghandle->lgh_hdr == NULL)
  81                 goto out;
  82
  83         if (loghandle->lgh_hdr->llh_flags & LLOG_F_IS_PLAIN)
  84                 LASSERT(list_empty(&loghandle->u.phd.phd_entry));
  85         else if (loghandle->lgh_hdr->llh_flags & LLOG_F_IS_CAT)
  86                 LASSERT(list_empty(&loghandle->u.chd.chd_head));
  87         OBD_FREE_LARGE(loghandle->lgh_hdr, loghandle->lgh_hdr_size);
  88 out:
  89         OBD_FREE_PTR(loghandle);
  90 }
  91
  92 void llog_handle_get(struct llog_handle *loghandle)
  93 {
  94         atomic_inc(&loghandle->lgh_refcount);
  95 }
  96
  97 void llog_handle_put(struct llog_handle *loghandle)
  98 {
  99         LASSERT(atomic_read(&loghandle->lgh_refcount) > 0);
 100         if (atomic_dec_and_test(&loghandle->lgh_refcount))
 101                 llog_free_handle(loghandle);
 102 }
 103
 104 static int llog_declare_destroy(const struct lu_env *env,
 105                                 struct llog_handle *handle,
 106                                 struct thandle *th)
 107 {
 108         struct llog_operations *lop;
 109         int rc;
 110
 111         ENTRY;
 112
 113         rc = llog_handle2ops(handle, &lop);
 114         if (rc)
 115                 RETURN(rc);
 116         if (lop->lop_declare_destroy == NULL)
 117                 RETURN(-EOPNOTSUPP);
 118
 119         rc = lop->lop_declare_destroy(env, handle, th);
 120
 121         RETURN(rc);
 122 }
 123
 124 int llog_trans_destroy(const struct lu_env *env, struct llog_handle *handle,
 125                        struct thandle *th)
 126 {
 127         struct llog_operations  *lop;
 128         int rc;
 129         ENTRY;
 130
 131         rc = llog_handle2ops(handle, &lop);
 132         if (rc < 0)
 133                 RETURN(rc);
 134         if (lop->lop_destroy == NULL)
 135                 RETURN(-EOPNOTSUPP);
 136
 137         LASSERT(handle->lgh_obj != NULL);
 138         if (!dt_object_exists(handle->lgh_obj))
 139                 RETURN(0);
 140
 141         rc = lop->lop_destroy(env, handle, th);
 142
 143         RETURN(rc);
 144 }
 145
 146 int llog_destroy(const struct lu_env *env, struct llog_handle *handle)
 147 {
 148         struct llog_operations  *lop;
 149         struct dt_device        *dt;
 150         struct thandle          *th;
 151         int rc;
 152
 153         ENTRY;
 154
 155         rc = llog_handle2ops(handle, &lop);
 156         if (rc < 0)
 157                 RETURN(rc);
 158         if (lop->lop_destroy == NULL)
 159                 RETURN(-EOPNOTSUPP);
 160
 161         if (handle->lgh_obj == NULL) {
 162                 /* if lgh_obj == NULL, then it is from client side destroy */
 163                 rc = lop->lop_destroy(env, handle, NULL);
 164                 RETURN(rc);
 165         }
 166
 167         if (!dt_object_exists(handle->lgh_obj))
 168                 RETURN(0);
 169
 170         dt = lu2dt_dev(handle->lgh_obj->do_lu.lo_dev);
 171
 172         th = dt_trans_create(env, dt);
 173         if (IS_ERR(th))
 174                 RETURN(PTR_ERR(th));
 175
 176         rc = llog_declare_destroy(env, handle, th);
 177         if (rc != 0)
 178                 GOTO(out_trans, rc);
 179
 180         rc = dt_trans_start_local(env, dt, th);
 181         if (rc < 0)
 182                 GOTO(out_trans, rc);
 183
 184         rc = lop->lop_destroy(env, handle, th);
 185
 186 out_trans:
 187         dt_trans_stop(env, dt, th);
 188
 189         RETURN(rc);
 190 }
 191 EXPORT_SYMBOL(llog_destroy);
 192
 193 /* returns negative on error; 0 if success; 1 if success & log destroyed */
 194 int llog_cancel_rec(const struct lu_env *env, struct llog_handle *loghandle,
 195                     int index)
 196 {
 197         struct llog_thread_info *lgi = llog_info(env);
 198         struct dt_device        *dt;
 199         struct llog_log_hdr     *llh = loghandle->lgh_hdr;
 200         struct thandle          *th;
 201         int                      rc;
 202         int rc1;
 203         bool subtract_count = false;
 204
 205         ENTRY;
 206
 207         CDEBUG(D_RPCTRACE, "Canceling %d in log "DOSTID"\n", index,
 208                POSTID(&loghandle->lgh_id.lgl_oi));
 209
 210         if (index == 0) {
 211                 CERROR("Can't cancel index 0 which is header\n");
 212                 RETURN(-EINVAL);
 213         }
 214
 215         LASSERT(loghandle != NULL);
 216         LASSERT(loghandle->lgh_ctxt != NULL);
 217         LASSERT(loghandle->lgh_obj != NULL);
 218
 219         dt = lu2dt_dev(loghandle->lgh_obj->do_lu.lo_dev);
 220
 221         th = dt_trans_create(env, dt);
 222         if (IS_ERR(th))
 223                 RETURN(PTR_ERR(th));
 224
 225         rc = llog_declare_write_rec(env, loghandle, &llh->llh_hdr, index, th);
 226         if (rc < 0)
 227                 GOTO(out_trans, rc);
 228
 229         if ((llh->llh_flags & LLOG_F_ZAP_WHEN_EMPTY)) {
 230                 rc = llog_declare_destroy(env, loghandle, th);
 231                 if (rc < 0)
 232                         GOTO(out_trans, rc);
 233         }
 234
 235         th->th_wait_submit = 1;
 236         rc = dt_trans_start_local(env, dt, th);
 237         if (rc < 0)
 238                 GOTO(out_trans, rc);
 239
 240         down_write(&loghandle->lgh_lock);
 241         /* clear bitmap */
 242         mutex_lock(&loghandle->lgh_hdr_mutex);
 243         if (!ext2_clear_bit(index, LLOG_HDR_BITMAP(llh))) {
 244                 CDEBUG(D_RPCTRACE, "Catalog index %u already clear?\n", index);
 245                 GOTO(out_unlock, rc);
 246         }
 247
 248         loghandle->lgh_hdr->llh_count--;
 249         subtract_count = true;
 250         /* Pass this index to llog_osd_write_rec(), which will use the index
 251          * to only update the necesary bitmap. */
 252         lgi->lgi_cookie.lgc_index = index;
 253         /* update header */
 254         rc = llog_write_rec(env, loghandle, &llh->llh_hdr, &lgi->lgi_cookie,
 255                             LLOG_HEADER_IDX, th);
 256         if (rc != 0)
 257                 GOTO(out_unlock, rc);
 258
 259         if ((llh->llh_flags & LLOG_F_ZAP_WHEN_EMPTY) &&
 260             (llh->llh_count == 1) &&
 261             ((loghandle->lgh_last_idx == LLOG_HDR_BITMAP_SIZE(llh) - 1) ||
 262              (loghandle->u.phd.phd_cat_handle != NULL &&
 263               loghandle->u.phd.phd_cat_handle->u.chd.chd_current_log !=
 264                 loghandle))) {
 265                 /* never try to destroy it again */
 266                 llh->llh_flags &= ~LLOG_F_ZAP_WHEN_EMPTY;
 267                 rc = llog_trans_destroy(env, loghandle, th);
 268                 if (rc < 0) {
 269                         /* Sigh, can not destroy the final plain llog, but
 270                          * the bitmap has been clearly, so the record can not
 271                          * be accessed anymore, let's return 0 for now, and
 272                          * the orphan will be handled by LFSCK. */
 273                         CERROR("%s: can't destroy empty llog #"DOSTID
 274                                "#%08x: rc = %d\n",
 275                                loghandle->lgh_ctxt->loc_obd->obd_name,
 276                                POSTID(&loghandle->lgh_id.lgl_oi),
 277                                loghandle->lgh_id.lgl_ogen, rc);
 278                         GOTO(out_unlock, rc);
 279                 }
 280                 rc = LLOG_DEL_PLAIN;
 281         }
 282
 283 out_unlock:
 284         mutex_unlock(&loghandle->lgh_hdr_mutex);
 285         up_write(&loghandle->lgh_lock);
 286 out_trans:
 287         rc1 = dt_trans_stop(env, dt, th);
 288         if (rc == 0)
 289                 rc = rc1;
 290         if (rc < 0 && subtract_count) {
 291                 mutex_lock(&loghandle->lgh_hdr_mutex);
 292                 loghandle->lgh_hdr->llh_count++;
 293                 ext2_set_bit(index, LLOG_HDR_BITMAP(llh));
 294                 mutex_unlock(&loghandle->lgh_hdr_mutex);
 295         }
 296         RETURN(rc);
 297 }
 298
 299 int llog_read_header(const struct lu_env *env, struct llog_handle *handle,
 300                      const struct obd_uuid *uuid)
 301 {
 302         struct llog_operations *lop;
 303         int rc;
 304         ENTRY;
 305
 306         rc = llog_handle2ops(handle, &lop);
 307         if (rc)
 308                 RETURN(rc);
 309
 310         if (lop->lop_read_header == NULL)
 311                 RETURN(-EOPNOTSUPP);
 312
 313         rc = lop->lop_read_header(env, handle);
 314         if (rc == LLOG_EEMPTY) {
 315                 struct llog_log_hdr *llh = handle->lgh_hdr;
 316
 317                 /* lrh_len should be initialized in llog_init_handle */
 318                 handle->lgh_last_idx = 0; /* header is record with index 0 */
 319                 handle->lgh_write_offset = 0;
 320                 llh->llh_count = 1;         /* for the header record */
 321                 llh->llh_hdr.lrh_type = LLOG_HDR_MAGIC;
 322                 LASSERT(handle->lgh_ctxt->loc_chunk_size >=
 323                                                 LLOG_MIN_CHUNK_SIZE);
 324                 llh->llh_hdr.lrh_len = handle->lgh_ctxt->loc_chunk_size;
 325                 llh->llh_hdr.lrh_index = 0;
 326                 llh->llh_timestamp = cfs_time_current_sec();
 327                 if (uuid)
 328                         memcpy(&llh->llh_tgtuuid, uuid,
 329                                sizeof(llh->llh_tgtuuid));
 330                 llh->llh_bitmap_offset = offsetof(typeof(*llh), llh_bitmap);
 331                 /* Since update llog header might also call this function,
 332                  * let's reset the bitmap to 0 here */
 333                 memset(LLOG_HDR_BITMAP(llh), 0, llh->llh_hdr.lrh_len -
 334                                                 llh->llh_bitmap_offset -
 335                                                 sizeof(llh->llh_tail));
 336                 ext2_set_bit(0, LLOG_HDR_BITMAP(llh));
 337                 LLOG_HDR_TAIL(llh)->lrt_len = llh->llh_hdr.lrh_len;
 338                 LLOG_HDR_TAIL(llh)->lrt_index = llh->llh_hdr.lrh_index;
 339                 rc = 0;
 340         }
 341         RETURN(rc);
 342 }
 343 EXPORT_SYMBOL(llog_read_header);
 344
 345 int llog_init_handle(const struct lu_env *env, struct llog_handle *handle,
 346                      int flags, struct obd_uuid *uuid)
 347 {
 348         struct llog_log_hdr     *llh;
 349         enum llog_flag           fmt = flags & LLOG_F_EXT_MASK;
 350         int                      rc;
 351         int                     chunk_size = handle->lgh_ctxt->loc_chunk_size;
 352         ENTRY;
 353
 354         LASSERT(handle->lgh_hdr == NULL);
 355
 356         LASSERT(chunk_size >= LLOG_MIN_CHUNK_SIZE);
 357         OBD_ALLOC_LARGE(llh, chunk_size);
 358         if (llh == NULL)
 359                 RETURN(-ENOMEM);
 360
 361         handle->lgh_hdr = llh;
 362         handle->lgh_hdr_size = chunk_size;
 363         /* first assign flags to use llog_client_ops */
 364         llh->llh_flags = flags;
 365         rc = llog_read_header(env, handle, uuid);
 366         if (rc == 0) {
 367                 if (unlikely((llh->llh_flags & LLOG_F_IS_PLAIN &&
 368                               flags & LLOG_F_IS_CAT) ||
 369                              (llh->llh_flags & LLOG_F_IS_CAT &&
 370                               flags & LLOG_F_IS_PLAIN))) {
 371                         CERROR("%s: llog type is %s but initializing %s\n",
 372                                handle->lgh_ctxt->loc_obd->obd_name,
 373                                llh->llh_flags & LLOG_F_IS_CAT ?
 374                                "catalog" : "plain",
 375                                flags & LLOG_F_IS_CAT ? "catalog" : "plain");
 376                         GOTO(out, rc = -EINVAL);
 377                 } else if (llh->llh_flags &
 378                            (LLOG_F_IS_PLAIN | LLOG_F_IS_CAT)) {
 379                         /*
 380                          * it is possible to open llog without specifying llog
 381                          * type so it is taken from llh_flags
 382                          */
 383                         flags = llh->llh_flags;
 384                 } else {
 385                         /* for some reason the llh_flags has no type set */
 386                         CERROR("llog type is not specified!\n");
 387                         GOTO(out, rc = -EINVAL);
 388                 }
 389                 if (unlikely(uuid &&
 390                              !obd_uuid_equals(uuid, &llh->llh_tgtuuid))) {
 391                         CERROR("%s: llog uuid mismatch: %s/%s\n",
 392                                handle->lgh_ctxt->loc_obd->obd_name,
 393                                (char *)uuid->uuid,
 394                                (char *)llh->llh_tgtuuid.uuid);
 395                         GOTO(out, rc = -EEXIST);
 396                 }
 397         }
 398         if (flags & LLOG_F_IS_CAT) {
 399                 LASSERT(list_empty(&handle->u.chd.chd_head));
 400                 INIT_LIST_HEAD(&handle->u.chd.chd_head);
 401                 llh->llh_size = sizeof(struct llog_logid_rec);
 402                 llh->llh_flags |= LLOG_F_IS_FIXSIZE;
 403         } else if (!(flags & LLOG_F_IS_PLAIN)) {
 404                 CERROR("%s: unknown flags: %#x (expected %#x or %#x)\n",
 405                        handle->lgh_ctxt->loc_obd->obd_name,
 406                        flags, LLOG_F_IS_CAT, LLOG_F_IS_PLAIN);
 407                 rc = -EINVAL;
 408         }
 409         llh->llh_flags |= fmt;
 410 out:
 411         if (rc) {
 412                 OBD_FREE_LARGE(llh, chunk_size);
 413                 handle->lgh_hdr = NULL;
 414         }
 415         RETURN(rc);
 416 }
 417 EXPORT_SYMBOL(llog_init_handle);
 418
 419 static int llog_process_thread(void *arg)
 420 {
 421         struct llog_process_info        *lpi = arg;
 422         struct llog_handle              *loghandle = lpi->lpi_loghandle;
 423         struct llog_log_hdr             *llh = loghandle->lgh_hdr;
 424         struct llog_process_cat_data    *cd  = lpi->lpi_catdata;
 425         char                            *buf;
 426         size_t                           chunk_size;
 427         __u64                            cur_offset, tmp_offset;
 428         int                              rc = 0, index = 1, last_index;
 429         int                              saved_index = 0;
 430         int                              last_called_index = 0;
 431
 432         ENTRY;
 433
 434         if (llh == NULL)
 435                 RETURN(-EINVAL);
 436
 437         cur_offset = chunk_size = llh->llh_hdr.lrh_len;
 438         /* expect chunk_size to be power of two */
 439         LASSERT(is_power_of_2(chunk_size));
 440
 441         OBD_ALLOC_LARGE(buf, chunk_size);
 442         if (buf == NULL) {
 443                 lpi->lpi_rc = -ENOMEM;
 444                 RETURN(0);
 445         }
 446
 447         if (cd != NULL) {
 448                 last_called_index = cd->lpcd_first_idx;
 449                 index = cd->lpcd_first_idx + 1;
 450         }
 451         if (cd != NULL && cd->lpcd_last_idx)
 452                 last_index = cd->lpcd_last_idx;
 453         else
 454                 last_index = LLOG_HDR_BITMAP_SIZE(llh) - 1;
 455
 456         while (rc == 0) {
 457                 struct llog_rec_hdr *rec;
 458                 off_t chunk_offset;
 459                 unsigned int buf_offset = 0;
 460                 bool partial_chunk;
 461
 462                 /* skip records not set in bitmap */
 463                 while (index <= last_index &&
 464                        !ext2_test_bit(index, LLOG_HDR_BITMAP(llh)))
 465                         ++index;
 466
 467                 /* There are no indices prior the last_index */
 468                 if (index > last_index)
 469                         break;
 470
 471                 CDEBUG(D_OTHER, "index: %d last_index %d\n", index,
 472                        last_index);
 473
 474 repeat:
 475                 /* get the buf with our target record; avoid old garbage */
 476                 memset(buf, 0, chunk_size);
 477                 rc = llog_next_block(lpi->lpi_env, loghandle, &saved_index,
 478                                      index, &cur_offset, buf, chunk_size);
 479                 if (rc != 0)
 480                         GOTO(out, rc);
 481
 482                 /* NB: after llog_next_block() call the cur_offset is the
 483                  * offset of the next block after read one.
 484                  * The absolute offset of the current chunk is calculated
 485                  * from cur_offset value and stored in chunk_offset variable.
 486                  */
 487                 tmp_offset = cur_offset;
 488                 if (do_div(tmp_offset, chunk_size) != 0) {
 489                         partial_chunk = true;
 490                         chunk_offset = cur_offset & ~(chunk_size - 1);
 491                 } else {
 492                         partial_chunk = false;
 493                         chunk_offset = cur_offset - chunk_size;
 494                 }
 495
 496                 /* NB: when rec->lrh_len is accessed it is already swabbed
 497                  * since it is used at the "end" of the loop and the rec
 498                  * swabbing is done at the beginning of the loop. */
 499                 for (rec = (struct llog_rec_hdr *)(buf + buf_offset);
 500                      (char *)rec < buf + chunk_size;
 501                      rec = llog_rec_hdr_next(rec)) {
 502
 503                         CDEBUG(D_OTHER, "processing rec 0x%p type %#x\n",
 504                                rec, rec->lrh_type);
 505
 506                         if (LLOG_REC_HDR_NEEDS_SWABBING(rec))
 507                                 lustre_swab_llog_rec(rec);
 508
 509                         CDEBUG(D_OTHER, "after swabbing, type=%#x idx=%d\n",
 510                                rec->lrh_type, rec->lrh_index);
 511
 512                         /* for partial chunk the end of it is zeroed, check
 513                          * for index 0 to distinguish it. */
 514                         if (partial_chunk && rec->lrh_index == 0) {
 515                                 /* concurrent llog_add() might add new records
 516                                  * while llog_processing, check this is not
 517                                  * the case and re-read the current chunk
 518                                  * otherwise. */
 519                                 int records;
 520                                 if (index > loghandle->lgh_last_idx)
 521                                         GOTO(out, rc = 0);
 522                                 /* <2 records means no more records
 523                                  * if the last record we processed was
 524                                  * the final one, then the underlying
 525                                  * object might have been destroyed yet.
 526                                  * we better don't access that.. */
 527                                 mutex_lock(&loghandle->lgh_hdr_mutex);
 528                                 records = loghandle->lgh_hdr->llh_count;
 529                                 mutex_unlock(&loghandle->lgh_hdr_mutex);
 530                                 if (records <= 1)
 531                                         GOTO(out, rc = 0);
 532                                 CDEBUG(D_OTHER, "Re-read last llog buffer for "
 533                                        "new records, index %u, last %u\n",
 534                                        index, loghandle->lgh_last_idx);
 535                                 /* save offset inside buffer for the re-read */
 536                                 buf_offset = (char *)rec - (char *)buf;
 537                                 cur_offset = chunk_offset;
 538                                 goto repeat;
 539                         }
 540
 541                         if (rec->lrh_len == 0 || rec->lrh_len > chunk_size) {
 542                                 CWARN("invalid length %d in llog record for "
 543                                       "index %d/%d\n", rec->lrh_len,
 544                                       rec->lrh_index, index);
 545                                 GOTO(out, rc = -EINVAL);
 546                         }
 547
 548                         if (rec->lrh_index < index) {
 549                                 CDEBUG(D_OTHER, "skipping lrh_index %d\n",
 550                                        rec->lrh_index);
 551                                 continue;
 552                         }
 553
 554                         if (rec->lrh_index != index) {
 555                                 CERROR("%s: Invalid record: index %u but "
 556                                        "expected %u\n",
 557                                        loghandle->lgh_ctxt->loc_obd->obd_name,
 558                                        rec->lrh_index, index);
 559                                 GOTO(out, rc = -ERANGE);
 560                         }
 561
 562                         CDEBUG(D_OTHER,
 563                                "lrh_index: %d lrh_len: %d (%d remains)\n",
 564                                rec->lrh_index, rec->lrh_len,
 565                                (int)(buf + chunk_size - (char *)rec));
 566
 567                         loghandle->lgh_cur_idx = rec->lrh_index;
 568                         loghandle->lgh_cur_offset = (char *)rec - (char *)buf +
 569                                                     chunk_offset;
 570
 571                         /* if set, process the callback on this record */
 572                         if (ext2_test_bit(index, LLOG_HDR_BITMAP(llh))) {
 573                                 rc = lpi->lpi_cb(lpi->lpi_env, loghandle, rec,
 574                                                  lpi->lpi_cbdata);
 575                                 last_called_index = index;
 576                                 if (rc == LLOG_PROC_BREAK) {
 577                                         GOTO(out, rc);
 578                                 } else if (rc == LLOG_DEL_RECORD) {
 579                                         rc = llog_cancel_rec(lpi->lpi_env,
 580                                                              loghandle,
 581                                                              rec->lrh_index);
 582                                 }
 583                                 if (rc)
 584                                         GOTO(out, rc);
 585                         }
 586                         /* exit if the last index is reached */
 587                         if (index >= last_index)
 588                                 GOTO(out, rc = 0);
 589                         ++index;
 590                 }
 591         }
 592
 593 out:
 594         if (cd != NULL)
 595                 cd->lpcd_last_idx = last_called_index;
 596
 597         if (unlikely(rc == -EIO && loghandle->lgh_obj != NULL)) {
 598                 if (dt_object_remote(loghandle->lgh_obj)) {
 599                         /* If it is remote object, then -EIO might means
 600                          * disconnection or eviction, let's return -EAGAIN,
 601                          * so for update recovery log processing, it will
 602                          * retry until the umount or abort recovery, see
 603                          * lod_sub_recovery_thread() */
 604                         CERROR("%s retry remote llog process\n",
 605                                loghandle->lgh_ctxt->loc_obd->obd_name);
 606                         rc = -EAGAIN;
 607                 } else {
 608                         /* something bad happened to the processing of a local
 609                          * llog file, probably I/O error or the log got
 610                          * corrupted to be able to finally release the log we
 611                          * discard any remaining bits in the header */
 612                         CERROR("Local llog found corrupted\n");
 613                         while (index <= last_index) {
 614                                 if (ext2_test_bit(index,
 615                                                   LLOG_HDR_BITMAP(llh)) != 0)
 616                                         llog_cancel_rec(lpi->lpi_env, loghandle,
 617                                                         index);
 618                                 index++;
 619                         }
 620                         rc = 0;
 621                 }
 622         }
 623
 624         OBD_FREE_LARGE(buf, chunk_size);
 625         lpi->lpi_rc = rc;
 626         return 0;
 627 }
 628
 629 static int llog_process_thread_daemonize(void *arg)
 630 {
 631         struct llog_process_info        *lpi = arg;
 632         struct lu_env                    env;
 633         int                              rc;
 634         struct nsproxy                  *new_ns, *curr_ns = current->nsproxy;
 635
 636         task_lock(lpi->lpi_reftask);
 637         new_ns = lpi->lpi_reftask->nsproxy;
 638         if (curr_ns != new_ns) {
 639                 get_nsproxy(new_ns);
 640
 641                 current->nsproxy = new_ns;
 642                 /* XXX: we should call put_nsproxy() instead of
 643                  * atomic_dec(&ns->count) directly. But put_nsproxy() cannot be
 644                  * used outside of the kernel itself, because it calls
 645                  * free_nsproxy() which is not exported by the kernel
 646                  * (defined in kernel/nsproxy.c) */
 647                 atomic_dec(&curr_ns->count);
 648         }
 649         task_unlock(lpi->lpi_reftask);
 650
 651         unshare_fs_struct();
 652
 653         /* client env has no keys, tags is just 0 */
 654         rc = lu_env_init(&env, LCT_LOCAL | LCT_MG_THREAD);
 655         if (rc)
 656                 goto out;
 657         lpi->lpi_env = &env;
 658
 659         rc = llog_process_thread(arg);
 660
 661         lu_env_fini(&env);
 662 out:
 663         complete(&lpi->lpi_completion);
 664         return rc;
 665 }
 666
 667 int llog_process_or_fork(const struct lu_env *env,
 668                          struct llog_handle *loghandle,
 669                          llog_cb_t cb, void *data, void *catdata, bool fork)
 670 {
 671         struct llog_process_info *lpi;
 672         int                      rc;
 673
 674         ENTRY;
 675
 676         OBD_ALLOC_PTR(lpi);
 677         if (lpi == NULL) {
 678                 CERROR("cannot alloc pointer\n");
 679                 RETURN(-ENOMEM);
 680         }
 681         lpi->lpi_loghandle = loghandle;
 682         lpi->lpi_cb        = cb;
 683         lpi->lpi_cbdata    = data;
 684         lpi->lpi_catdata   = catdata;
 685
 686         if (fork) {
 687                 struct task_struct *task;
 688
 689                 /* The new thread can't use parent env,
 690                  * init the new one in llog_process_thread_daemonize. */
 691                 lpi->lpi_env = NULL;
 692                 init_completion(&lpi->lpi_completion);
 693                 /* take reference to current, so that
 694                  * llog_process_thread_daemonize() can use it to switch to
 695                  * namespace associated with current  */
 696                 lpi->lpi_reftask = current;
 697                 task = kthread_run(llog_process_thread_daemonize, lpi,
 698                                    "llog_process_thread");
 699                 if (IS_ERR(task)) {
 700                         rc = PTR_ERR(task);
 701                         CERROR("%s: cannot start thread: rc = %d\n",
 702                                loghandle->lgh_ctxt->loc_obd->obd_name, rc);
 703                         GOTO(out_lpi, rc);
 704                 }
 705                 wait_for_completion(&lpi->lpi_completion);
 706         } else {
 707                 lpi->lpi_env = env;
 708                 llog_process_thread(lpi);
 709         }
 710         rc = lpi->lpi_rc;
 711
 712 out_lpi:
 713         OBD_FREE_PTR(lpi);
 714         RETURN(rc);
 715 }
 716 EXPORT_SYMBOL(llog_process_or_fork);
 717
 718 int llog_process(const struct lu_env *env, struct llog_handle *loghandle,
 719                  llog_cb_t cb, void *data, void *catdata)
 720 {
 721         int rc;
 722         rc = llog_process_or_fork(env, loghandle, cb, data, catdata, true);
 723         return rc == LLOG_DEL_PLAIN ? 0 : rc;
 724 }
 725 EXPORT_SYMBOL(llog_process);
 726
 727 int llog_reverse_process(const struct lu_env *env,
 728                          struct llog_handle *loghandle, llog_cb_t cb,
 729                          void *data, void *catdata)
 730 {
 731         struct llog_log_hdr *llh = loghandle->lgh_hdr;
 732         struct llog_process_cat_data *cd = catdata;
 733         void *buf;
 734         int rc = 0, first_index = 1, index, idx;
 735         __u32   chunk_size = llh->llh_hdr.lrh_len;
 736         ENTRY;
 737
 738         OBD_ALLOC_LARGE(buf, chunk_size);
 739         if (buf == NULL)
 740                 RETURN(-ENOMEM);
 741
 742         if (cd != NULL)
 743                 first_index = cd->lpcd_first_idx + 1;
 744         if (cd != NULL && cd->lpcd_last_idx)
 745                 index = cd->lpcd_last_idx;
 746         else
 747                 index = LLOG_HDR_BITMAP_SIZE(llh) - 1;
 748
 749         while (rc == 0) {
 750                 struct llog_rec_hdr *rec;
 751                 struct llog_rec_tail *tail;
 752
 753                 /* skip records not set in bitmap */
 754                 while (index >= first_index &&
 755                        !ext2_test_bit(index, LLOG_HDR_BITMAP(llh)))
 756                         --index;
 757
 758                 LASSERT(index >= first_index - 1);
 759                 if (index == first_index - 1)
 760                         break;
 761
 762                 /* get the buf with our target record; avoid old garbage */
 763                 memset(buf, 0, chunk_size);
 764                 rc = llog_prev_block(env, loghandle, index, buf, chunk_size);
 765                 if (rc)
 766                         GOTO(out, rc);
 767
 768                 rec = buf;
 769                 idx = rec->lrh_index;
 770                 CDEBUG(D_RPCTRACE, "index %u : idx %u\n", index, idx);
 771                 while (idx < index) {
 772                         rec = (void *)rec + rec->lrh_len;
 773                         if (LLOG_REC_HDR_NEEDS_SWABBING(rec))
 774                                 lustre_swab_llog_rec(rec);
 775                         idx ++;
 776                 }
 777                 LASSERT(idx == index);
 778                 tail = (void *)rec + rec->lrh_len - sizeof(*tail);
 779
 780                 /* process records in buffer, starting where we found one */
 781                 while ((void *)tail > buf) {
 782                         if (tail->lrt_index == 0)
 783                                 GOTO(out, rc = 0); /* no more records */
 784
 785                         /* if set, process the callback on this record */
 786                         if (ext2_test_bit(index, LLOG_HDR_BITMAP(llh))) {
 787                                 rec = (void *)tail - tail->lrt_len +
 788                                       sizeof(*tail);
 789
 790                                 rc = cb(env, loghandle, rec, data);
 791                                 if (rc == LLOG_PROC_BREAK) {
 792                                         GOTO(out, rc);
 793                                 } else if (rc == LLOG_DEL_RECORD) {
 794                                         rc = llog_cancel_rec(env, loghandle,
 795                                                              tail->lrt_index);
 796                                 }
 797                                 if (rc)
 798                                         GOTO(out, rc);
 799                         }
 800
 801                         /* previous record, still in buffer? */
 802                         --index;
 803                         if (index < first_index)
 804                                 GOTO(out, rc = 0);
 805                         tail = (void *)tail - tail->lrt_len;
 806                 }
 807         }
 808
 809 out:
 810         if (buf != NULL)
 811                 OBD_FREE_LARGE(buf, chunk_size);
 812         RETURN(rc);
 813 }
 814 EXPORT_SYMBOL(llog_reverse_process);
 815
 816 /**
 817  * new llog API
 818  *
 819  * API functions:
 820  *      llog_open - open llog, may not exist
 821  *      llog_exist - check if llog exists
 822  *      llog_close - close opened llog, pair for open, frees llog_handle
 823  *      llog_declare_create - declare llog creation
 824  *      llog_create - create new llog on disk, need transaction handle
 825  *      llog_declare_write_rec - declaration of llog write
 826  *      llog_write_rec - write llog record on disk, need transaction handle
 827  *      llog_declare_add - declare llog catalog record addition
 828  *      llog_add - add llog record in catalog, need transaction handle
 829  */
 830 int llog_exist(struct llog_handle *loghandle)
 831 {
 832         struct llog_operations  *lop;
 833         int                      rc;
 834
 835         ENTRY;
 836
 837         rc = llog_handle2ops(loghandle, &lop);
 838         if (rc)
 839                 RETURN(rc);
 840         if (lop->lop_exist == NULL)
 841                 RETURN(-EOPNOTSUPP);
 842
 843         rc = lop->lop_exist(loghandle);
 844         RETURN(rc);
 845 }
 846 EXPORT_SYMBOL(llog_exist);
 847
 848 int llog_declare_create(const struct lu_env *env,
 849                         struct llog_handle *loghandle, struct thandle *th)
 850 {
 851         struct llog_operations  *lop;
 852         int                      raised, rc;
 853
 854         ENTRY;
 855
 856         rc = llog_handle2ops(loghandle, &lop);
 857         if (rc)
 858                 RETURN(rc);
 859         if (lop->lop_declare_create == NULL)
 860                 RETURN(-EOPNOTSUPP);
 861
 862         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 863         if (!raised)
 864                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 865         rc = lop->lop_declare_create(env, loghandle, th);
 866         if (!raised)
 867                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 868         RETURN(rc);
 869 }
 870
 871 int llog_create(const struct lu_env *env, struct llog_handle *handle,
 872                 struct thandle *th)
 873 {
 874         struct llog_operations  *lop;
 875         int                      raised, rc;
 876
 877         ENTRY;
 878
 879         rc = llog_handle2ops(handle, &lop);
 880         if (rc)
 881                 RETURN(rc);
 882         if (lop->lop_create == NULL)
 883                 RETURN(-EOPNOTSUPP);
 884
 885         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 886         if (!raised)
 887                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 888         rc = lop->lop_create(env, handle, th);
 889         if (!raised)
 890                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 891         RETURN(rc);
 892 }
 893
 894 int llog_declare_write_rec(const struct lu_env *env,
 895                            struct llog_handle *handle,
 896                            struct llog_rec_hdr *rec, int idx,
 897                            struct thandle *th)
 898 {
 899         struct llog_operations  *lop;
 900         int                      raised, rc;
 901
 902         ENTRY;
 903
 904         rc = llog_handle2ops(handle, &lop);
 905         if (rc)
 906                 RETURN(rc);
 907         LASSERT(lop);
 908         if (lop->lop_declare_write_rec == NULL)
 909                 RETURN(-EOPNOTSUPP);
 910
 911         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 912         if (!raised)
 913                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 914         rc = lop->lop_declare_write_rec(env, handle, rec, idx, th);
 915         if (!raised)
 916                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 917         RETURN(rc);
 918 }
 919
 920 int llog_write_rec(const struct lu_env *env, struct llog_handle *handle,
 921                    struct llog_rec_hdr *rec, struct llog_cookie *logcookies,
 922                    int idx, struct thandle *th)
 923 {
 924         struct llog_operations  *lop;
 925         int                      raised, rc, buflen;
 926
 927         ENTRY;
 928
 929         /* API sanity checks */
 930         if (handle == NULL) {
 931                 CERROR("loghandle is missed\n");
 932                 RETURN(-EPROTO);
 933         } else if (handle->lgh_obj == NULL) {
 934                 CERROR("loghandle %p with NULL object\n",
 935                         handle);
 936                 RETURN(-EPROTO);
 937         } else if (th == NULL) {
 938                 CERROR("%s: missed transaction handle\n",
 939                         handle->lgh_obj->do_lu.lo_dev->ld_obd->obd_name);
 940                 RETURN(-EPROTO);
 941         } else if (handle->lgh_hdr == NULL) {
 942                 CERROR("%s: loghandle %p with no header\n",
 943                         handle->lgh_obj->do_lu.lo_dev->ld_obd->obd_name,
 944                         handle);
 945                 RETURN(-EPROTO);
 946         }
 947
 948         rc = llog_handle2ops(handle, &lop);
 949         if (rc)
 950                 RETURN(rc);
 951
 952         if (lop->lop_write_rec == NULL)
 953                 RETURN(-EOPNOTSUPP);
 954
 955         buflen = rec->lrh_len;
 956         LASSERT(cfs_size_round(buflen) == buflen);
 957
 958         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 959         if (!raised)
 960                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 961         rc = lop->lop_write_rec(env, handle, rec, logcookies, idx, th);
 962         if (!raised)
 963                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 964         RETURN(rc);
 965 }
 966
 967 int llog_add(const struct lu_env *env, struct llog_handle *lgh,
 968              struct llog_rec_hdr *rec, struct llog_cookie *logcookies,
 969              struct thandle *th)
 970 {
 971         int raised, rc;
 972
 973         ENTRY;
 974
 975         if (lgh->lgh_logops->lop_add == NULL)
 976                 RETURN(-EOPNOTSUPP);
 977
 978         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 979         if (!raised)
 980                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 981         rc = lgh->lgh_logops->lop_add(env, lgh, rec, logcookies, th);
 982         if (!raised)
 983                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 984         RETURN(rc);
 985 }
 986 EXPORT_SYMBOL(llog_add);
 987
 988 int llog_declare_add(const struct lu_env *env, struct llog_handle *lgh,
 989                      struct llog_rec_hdr *rec, struct thandle *th)
 990 {
 991         int raised, rc;
 992
 993         ENTRY;
 994
 995         if (lgh->lgh_logops->lop_declare_add == NULL)
 996                 RETURN(-EOPNOTSUPP);
 997
 998         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 999         if (!raised)
1000                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
1001         rc = lgh->lgh_logops->lop_declare_add(env, lgh, rec, th);
1002         if (!raised)
1003                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
1004         RETURN(rc);
1005 }
1006 EXPORT_SYMBOL(llog_declare_add);
1007
1008 /**
1009  * Helper function to open llog or create it if doesn't exist.
1010  * It hides all transaction handling from caller.
1011  */
1012 int llog_open_create(const struct lu_env *env, struct llog_ctxt *ctxt,
1013                      struct llog_handle **res, struct llog_logid *logid,
1014                      char *name)
1015 {
1016         struct dt_device        *d;
1017         struct thandle          *th;
1018         int                      rc;
1019
1020         ENTRY;
1021
1022         rc = llog_open(env, ctxt, res, logid, name, LLOG_OPEN_NEW);
1023         if (rc)
1024                 RETURN(rc);
1025
1026         if (llog_exist(*res))
1027                 RETURN(0);
1028
1029         LASSERT((*res)->lgh_obj != NULL);
1030
1031         d = lu2dt_dev((*res)->lgh_obj->do_lu.lo_dev);
1032
1033         th = dt_trans_create(env, d);
1034         if (IS_ERR(th))
1035                 GOTO(out, rc = PTR_ERR(th));
1036
1037         /* Create update llog object synchronously, which
1038          * happens during inialization process see
1039          * lod_sub_prep_llog(), to make sure the update
1040          * llog object is created before corss-MDT writing
1041          * updates into the llog object */
1042         if (ctxt->loc_flags & LLOG_CTXT_FLAG_NORMAL_FID)
1043                 th->th_sync = 1;
1044
1045         th->th_wait_submit = 1;
1046         rc = llog_declare_create(env, *res, th);
1047         if (rc == 0) {
1048                 rc = dt_trans_start_local(env, d, th);
1049                 if (rc == 0)
1050                         rc = llog_create(env, *res, th);
1051         }
1052         dt_trans_stop(env, d, th);
1053 out:
1054         if (rc)
1055                 llog_close(env, *res);
1056         RETURN(rc);
1057 }
1058 EXPORT_SYMBOL(llog_open_create);
1059
1060 /**
1061  * Helper function to delete existent llog.
1062  */
1063 int llog_erase(const struct lu_env *env, struct llog_ctxt *ctxt,
1064                struct llog_logid *logid, char *name)
1065 {
1066         struct llog_handle      *handle;
1067         int                      rc = 0, rc2;
1068
1069         ENTRY;
1070
1071         /* nothing to erase */
1072         if (name == NULL && logid == NULL)
1073                 RETURN(0);
1074
1075         rc = llog_open(env, ctxt, &handle, logid, name, LLOG_OPEN_EXISTS);
1076         if (rc < 0)
1077                 RETURN(rc);
1078
1079         rc = llog_init_handle(env, handle, LLOG_F_IS_PLAIN, NULL);
1080         if (rc == 0)
1081                 rc = llog_destroy(env, handle);
1082
1083         rc2 = llog_close(env, handle);
1084         if (rc == 0)
1085                 rc = rc2;
1086         RETURN(rc);
1087 }
1088 EXPORT_SYMBOL(llog_erase);
1089
1090 /*
1091  * Helper function for write record in llog.
1092  * It hides all transaction handling from caller.
1093  * Valid only with local llog.
1094  */
1095 int llog_write(const struct lu_env *env, struct llog_handle *loghandle,
1096                struct llog_rec_hdr *rec, int idx)
1097 {
1098         struct dt_device        *dt;
1099         struct thandle          *th;
1100         int                      rc;
1101
1102         ENTRY;
1103
1104         LASSERT(loghandle);
1105         LASSERT(loghandle->lgh_ctxt);
1106         LASSERT(loghandle->lgh_obj != NULL);
1107
1108         dt = lu2dt_dev(loghandle->lgh_obj->do_lu.lo_dev);
1109
1110         th = dt_trans_create(env, dt);
1111         if (IS_ERR(th))
1112                 RETURN(PTR_ERR(th));
1113
1114         rc = llog_declare_write_rec(env, loghandle, rec, idx, th);
1115         if (rc)
1116                 GOTO(out_trans, rc);
1117
1118         th->th_wait_submit = 1;
1119         rc = dt_trans_start_local(env, dt, th);
1120         if (rc)
1121                 GOTO(out_trans, rc);
1122
1123         down_write(&loghandle->lgh_lock);
1124         rc = llog_write_rec(env, loghandle, rec, NULL, idx, th);
1125         up_write(&loghandle->lgh_lock);
1126 out_trans:
1127         dt_trans_stop(env, dt, th);
1128         RETURN(rc);
1129 }
1130 EXPORT_SYMBOL(llog_write);
1131
1132 int llog_open(const struct lu_env *env, struct llog_ctxt *ctxt,
1133               struct llog_handle **lgh, struct llog_logid *logid,
1134               char *name, enum llog_open_param open_param)
1135 {
1136         int      raised;
1137         int      rc;
1138
1139         ENTRY;
1140
1141         LASSERT(ctxt);
1142         LASSERT(ctxt->loc_logops);
1143
1144         if (ctxt->loc_logops->lop_open == NULL) {
1145                 *lgh = NULL;
1146                 RETURN(-EOPNOTSUPP);
1147         }
1148
1149         *lgh = llog_alloc_handle();
1150         if (*lgh == NULL)
1151                 RETURN(-ENOMEM);
1152         (*lgh)->lgh_ctxt = ctxt;
1153         (*lgh)->lgh_logops = ctxt->loc_logops;
1154
1155         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
1156         if (!raised)
1157                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
1158         rc = ctxt->loc_logops->lop_open(env, *lgh, logid, name, open_param);
1159         if (!raised)
1160                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
1161         if (rc) {
1162                 llog_free_handle(*lgh);
1163                 *lgh = NULL;
1164         }
1165         RETURN(rc);
1166 }
1167 EXPORT_SYMBOL(llog_open);
1168
1169 int llog_close(const struct lu_env *env, struct llog_handle *loghandle)
1170 {
1171         struct llog_operations  *lop;
1172         int                      rc;
1173
1174         ENTRY;
1175
1176         rc = llog_handle2ops(loghandle, &lop);
1177         if (rc)
1178                 GOTO(out, rc);
1179         if (lop->lop_close == NULL)
1180                 GOTO(out, rc = -EOPNOTSUPP);
1181         rc = lop->lop_close(env, loghandle);
1182 out:
1183         llog_handle_put(loghandle);
1184         RETURN(rc);
1185 }
1186 EXPORT_SYMBOL(llog_close);
1187
1188 /**
1189  * Helper function to get the llog size in records. It is used by MGS
1190  * mostly to check that config llog exists and contains data.
1191  *
1192  * \param[in] env       execution environment
1193  * \param[in] ctxt      llog context
1194  * \param[in] name      llog name
1195  *
1196  * \retval              true if there are records in llog besides a header
1197  * \retval              false on error or llog without records
1198  */
1199 int llog_is_empty(const struct lu_env *env, struct llog_ctxt *ctxt,
1200                   char *name)
1201 {
1202         struct llog_handle      *llh;
1203         int                      rc = 0;
1204
1205         rc = llog_open(env, ctxt, &llh, NULL, name, LLOG_OPEN_EXISTS);
1206         if (rc < 0) {
1207                 if (likely(rc == -ENOENT))
1208                         rc = 0;
1209                 GOTO(out, rc);
1210         }
1211
1212         rc = llog_init_handle(env, llh, LLOG_F_IS_PLAIN, NULL);
1213         if (rc)
1214                 GOTO(out_close, rc);
1215         rc = llog_get_size(llh);
1216
1217 out_close:
1218         llog_close(env, llh);
1219 out:
1220         /* The header is record 1, the llog is still considered as empty
1221          * if there is only header */
1222         return (rc <= 1);
1223 }
1224 EXPORT_SYMBOL(llog_is_empty);
1225
1226 int llog_copy_handler(const struct lu_env *env, struct llog_handle *llh,
1227                       struct llog_rec_hdr *rec, void *data)
1228 {
1229         struct llog_handle      *copy_llh = data;
1230
1231         /* Append all records */
1232         return llog_write(env, copy_llh, rec, LLOG_NEXT_IDX);
1233 }
1234
1235 /* backup plain llog */
1236 int llog_backup(const struct lu_env *env, struct obd_device *obd,
1237                 struct llog_ctxt *ctxt, struct llog_ctxt *bctxt,
1238                 char *name, char *backup)
1239 {
1240         struct llog_handle      *llh, *bllh;
1241         int                      rc;
1242
1243         ENTRY;
1244
1245         /* open original log */
1246         rc = llog_open(env, ctxt, &llh, NULL, name, LLOG_OPEN_EXISTS);
1247         if (rc < 0) {
1248                 /* the -ENOENT case is also reported to the caller
1249                  * but silently so it should handle that if needed.
1250                  */
1251                 if (rc != -ENOENT)
1252                         CERROR("%s: failed to open log %s: rc = %d\n",
1253                                obd->obd_name, name, rc);
1254                 RETURN(rc);
1255         }
1256
1257         rc = llog_init_handle(env, llh, LLOG_F_IS_PLAIN, NULL);
1258         if (rc)
1259                 GOTO(out_close, rc);
1260
1261         /* Make sure there's no old backup log */
1262         rc = llog_erase(env, bctxt, NULL, backup);
1263         if (rc < 0 && rc != -ENOENT)
1264                 GOTO(out_close, rc);
1265
1266         /* open backup log */
1267         rc = llog_open_create(env, bctxt, &bllh, NULL, backup);
1268         if (rc) {
1269                 CERROR("%s: failed to open backup logfile %s: rc = %d\n",
1270                        obd->obd_name, backup, rc);
1271                 GOTO(out_close, rc);
1272         }
1273
1274         /* check that backup llog is not the same object as original one */
1275         if (llh->lgh_obj == bllh->lgh_obj) {
1276                 CERROR("%s: backup llog %s to itself (%s), objects %p/%p\n",
1277                        obd->obd_name, name, backup, llh->lgh_obj,
1278                        bllh->lgh_obj);
1279                 GOTO(out_backup, rc = -EEXIST);
1280         }
1281
1282         rc = llog_init_handle(env, bllh, LLOG_F_IS_PLAIN, NULL);
1283         if (rc)
1284                 GOTO(out_backup, rc);
1285
1286         /* Copy log record by record */
1287         rc = llog_process_or_fork(env, llh, llog_copy_handler, (void *)bllh,
1288                                   NULL, false);
1289         if (rc)
1290                 CERROR("%s: failed to backup log %s: rc = %d\n",
1291                        obd->obd_name, name, rc);
1292 out_backup:
1293         llog_close(env, bllh);
1294 out_close:
1295         llog_close(env, llh);
1296         RETURN(rc);
1297 }
1298 EXPORT_SYMBOL(llog_backup);
1299
1300 /* Get size of llog */
1301 __u64 llog_size(const struct lu_env *env, struct llog_handle *llh)
1302 {
1303         int rc;
1304         struct lu_attr la;
1305
1306         rc = llh->lgh_obj->do_ops->do_attr_get(env, llh->lgh_obj, &la);
1307         if (rc) {
1308                 CERROR("%s: attr_get failed, rc = %d\n",
1309                        llh->lgh_ctxt->loc_obd->obd_name, rc);
1310                 return 0;
1311         }
1312
1313         return la.la_size;
1314 }
1315 EXPORT_SYMBOL(llog_size);
1316