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, 2016, 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                 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("%s: invalid length %d in llog "DOSTID
 542                                       "record for index %d/%d\n",
 543                                        loghandle->lgh_ctxt->loc_obd->obd_name,
 544                                        rec->lrh_len,
 545                                        POSTID(&loghandle->lgh_id.lgl_oi),
 546                                        rec->lrh_index, index);
 547
 548                                 GOTO(out, rc = -EINVAL);
 549                         }
 550
 551                         if (rec->lrh_index < index) {
 552                                 CDEBUG(D_OTHER, "skipping lrh_index %d\n",
 553                                        rec->lrh_index);
 554                                 continue;
 555                         }
 556
 557                         if (rec->lrh_index != index) {
 558                                 CERROR("%s: "DOSTID" Invalid record: index %u"
 559                                        " but expected %u\n",
 560                                        loghandle->lgh_ctxt->loc_obd->obd_name,
 561                                        POSTID(&loghandle->lgh_id.lgl_oi),
 562                                        rec->lrh_index, index);
 563                                 GOTO(out, rc = -ERANGE);
 564                         }
 565
 566                         CDEBUG(D_OTHER,
 567                                "lrh_index: %d lrh_len: %d (%d remains)\n",
 568                                rec->lrh_index, rec->lrh_len,
 569                                (int)(buf + chunk_size - (char *)rec));
 570
 571                         loghandle->lgh_cur_idx = rec->lrh_index;
 572                         loghandle->lgh_cur_offset = (char *)rec - (char *)buf +
 573                                                     chunk_offset;
 574
 575                         /* if set, process the callback on this record */
 576                         if (ext2_test_bit(index, LLOG_HDR_BITMAP(llh))) {
 577                                 rc = lpi->lpi_cb(lpi->lpi_env, loghandle, rec,
 578                                                  lpi->lpi_cbdata);
 579                                 last_called_index = index;
 580                                 if (rc == LLOG_PROC_BREAK) {
 581                                         GOTO(out, rc);
 582                                 } else if (rc == LLOG_DEL_RECORD) {
 583                                         rc = llog_cancel_rec(lpi->lpi_env,
 584                                                              loghandle,
 585                                                              rec->lrh_index);
 586                                 }
 587                                 if (rc)
 588                                         GOTO(out, rc);
 589                         }
 590                         /* exit if the last index is reached */
 591                         if (index >= last_index)
 592                                 GOTO(out, rc = 0);
 593                         ++index;
 594                 }
 595         }
 596
 597 out:
 598         if (cd != NULL)
 599                 cd->lpcd_last_idx = last_called_index;
 600
 601         if (unlikely(rc == -EIO && loghandle->lgh_obj != NULL)) {
 602                 if (dt_object_remote(loghandle->lgh_obj)) {
 603                         /* If it is remote object, then -EIO might means
 604                          * disconnection or eviction, let's return -EAGAIN,
 605                          * so for update recovery log processing, it will
 606                          * retry until the umount or abort recovery, see
 607                          * lod_sub_recovery_thread() */
 608                         CERROR("%s retry remote llog process\n",
 609                                loghandle->lgh_ctxt->loc_obd->obd_name);
 610                         rc = -EAGAIN;
 611                 } else {
 612                         /* something bad happened to the processing of a local
 613                          * llog file, probably I/O error or the log got
 614                          * corrupted to be able to finally release the log we
 615                          * discard any remaining bits in the header */
 616                         CERROR("Local llog found corrupted\n");
 617                         while (index <= last_index) {
 618                                 if (ext2_test_bit(index,
 619                                                   LLOG_HDR_BITMAP(llh)) != 0)
 620                                         llog_cancel_rec(lpi->lpi_env, loghandle,
 621                                                         index);
 622                                 index++;
 623                         }
 624                         rc = 0;
 625                 }
 626         }
 627
 628         OBD_FREE_LARGE(buf, chunk_size);
 629         lpi->lpi_rc = rc;
 630         return 0;
 631 }
 632
 633 static int llog_process_thread_daemonize(void *arg)
 634 {
 635         struct llog_process_info        *lpi = arg;
 636         struct lu_env                    env;
 637         int                              rc;
 638         struct nsproxy                  *new_ns, *curr_ns = current->nsproxy;
 639
 640         task_lock(lpi->lpi_reftask);
 641         new_ns = lpi->lpi_reftask->nsproxy;
 642         if (curr_ns != new_ns) {
 643                 get_nsproxy(new_ns);
 644
 645                 current->nsproxy = new_ns;
 646                 /* XXX: we should call put_nsproxy() instead of
 647                  * atomic_dec(&ns->count) directly. But put_nsproxy() cannot be
 648                  * used outside of the kernel itself, because it calls
 649                  * free_nsproxy() which is not exported by the kernel
 650                  * (defined in kernel/nsproxy.c) */
 651                 atomic_dec(&curr_ns->count);
 652         }
 653         task_unlock(lpi->lpi_reftask);
 654
 655         unshare_fs_struct();
 656
 657         /* client env has no keys, tags is just 0 */
 658         rc = lu_env_init(&env, LCT_LOCAL | LCT_MG_THREAD);
 659         if (rc)
 660                 goto out;
 661         lpi->lpi_env = &env;
 662
 663         rc = llog_process_thread(arg);
 664
 665         lu_env_fini(&env);
 666 out:
 667         complete(&lpi->lpi_completion);
 668         return rc;
 669 }
 670
 671 int llog_process_or_fork(const struct lu_env *env,
 672                          struct llog_handle *loghandle,
 673                          llog_cb_t cb, void *data, void *catdata, bool fork)
 674 {
 675         struct llog_process_info *lpi;
 676         int                      rc;
 677
 678         ENTRY;
 679
 680         OBD_ALLOC_PTR(lpi);
 681         if (lpi == NULL) {
 682                 CERROR("cannot alloc pointer\n");
 683                 RETURN(-ENOMEM);
 684         }
 685         lpi->lpi_loghandle = loghandle;
 686         lpi->lpi_cb        = cb;
 687         lpi->lpi_cbdata    = data;
 688         lpi->lpi_catdata   = catdata;
 689
 690         if (fork) {
 691                 struct task_struct *task;
 692
 693                 /* The new thread can't use parent env,
 694                  * init the new one in llog_process_thread_daemonize. */
 695                 lpi->lpi_env = NULL;
 696                 init_completion(&lpi->lpi_completion);
 697                 /* take reference to current, so that
 698                  * llog_process_thread_daemonize() can use it to switch to
 699                  * namespace associated with current  */
 700                 lpi->lpi_reftask = current;
 701                 task = kthread_run(llog_process_thread_daemonize, lpi,
 702                                    "llog_process_thread");
 703                 if (IS_ERR(task)) {
 704                         rc = PTR_ERR(task);
 705                         CERROR("%s: cannot start thread: rc = %d\n",
 706                                loghandle->lgh_ctxt->loc_obd->obd_name, rc);
 707                         GOTO(out_lpi, rc);
 708                 }
 709                 wait_for_completion(&lpi->lpi_completion);
 710         } else {
 711                 lpi->lpi_env = env;
 712                 llog_process_thread(lpi);
 713         }
 714         rc = lpi->lpi_rc;
 715
 716 out_lpi:
 717         OBD_FREE_PTR(lpi);
 718         RETURN(rc);
 719 }
 720 EXPORT_SYMBOL(llog_process_or_fork);
 721
 722 int llog_process(const struct lu_env *env, struct llog_handle *loghandle,
 723                  llog_cb_t cb, void *data, void *catdata)
 724 {
 725         int rc;
 726         rc = llog_process_or_fork(env, loghandle, cb, data, catdata, true);
 727         return rc == LLOG_DEL_PLAIN ? 0 : rc;
 728 }
 729 EXPORT_SYMBOL(llog_process);
 730
 731 int llog_reverse_process(const struct lu_env *env,
 732                          struct llog_handle *loghandle, llog_cb_t cb,
 733                          void *data, void *catdata)
 734 {
 735         struct llog_log_hdr *llh = loghandle->lgh_hdr;
 736         struct llog_process_cat_data *cd = catdata;
 737         void *buf;
 738         int rc = 0, first_index = 1, index, idx;
 739         __u32   chunk_size = llh->llh_hdr.lrh_len;
 740         ENTRY;
 741
 742         OBD_ALLOC_LARGE(buf, chunk_size);
 743         if (buf == NULL)
 744                 RETURN(-ENOMEM);
 745
 746         if (cd != NULL)
 747                 first_index = cd->lpcd_first_idx + 1;
 748         if (cd != NULL && cd->lpcd_last_idx)
 749                 index = cd->lpcd_last_idx;
 750         else
 751                 index = LLOG_HDR_BITMAP_SIZE(llh) - 1;
 752
 753         while (rc == 0) {
 754                 struct llog_rec_hdr *rec;
 755                 struct llog_rec_tail *tail;
 756
 757                 /* skip records not set in bitmap */
 758                 while (index >= first_index &&
 759                        !ext2_test_bit(index, LLOG_HDR_BITMAP(llh)))
 760                         --index;
 761
 762                 LASSERT(index >= first_index - 1);
 763                 if (index == first_index - 1)
 764                         break;
 765
 766                 /* get the buf with our target record; avoid old garbage */
 767                 memset(buf, 0, chunk_size);
 768                 rc = llog_prev_block(env, loghandle, index, buf, chunk_size);
 769                 if (rc)
 770                         GOTO(out, rc);
 771
 772                 rec = buf;
 773                 idx = rec->lrh_index;
 774                 CDEBUG(D_RPCTRACE, "index %u : idx %u\n", index, idx);
 775                 while (idx < index) {
 776                         rec = (void *)rec + rec->lrh_len;
 777                         if (LLOG_REC_HDR_NEEDS_SWABBING(rec))
 778                                 lustre_swab_llog_rec(rec);
 779                         idx ++;
 780                 }
 781                 LASSERT(idx == index);
 782                 tail = (void *)rec + rec->lrh_len - sizeof(*tail);
 783
 784                 /* process records in buffer, starting where we found one */
 785                 while ((void *)tail > buf) {
 786                         if (tail->lrt_index == 0)
 787                                 GOTO(out, rc = 0); /* no more records */
 788
 789                         /* if set, process the callback on this record */
 790                         if (ext2_test_bit(index, LLOG_HDR_BITMAP(llh))) {
 791                                 rec = (void *)tail - tail->lrt_len +
 792                                       sizeof(*tail);
 793
 794                                 rc = cb(env, loghandle, rec, data);
 795                                 if (rc == LLOG_PROC_BREAK) {
 796                                         GOTO(out, rc);
 797                                 } else if (rc == LLOG_DEL_RECORD) {
 798                                         rc = llog_cancel_rec(env, loghandle,
 799                                                              tail->lrt_index);
 800                                 }
 801                                 if (rc)
 802                                         GOTO(out, rc);
 803                         }
 804
 805                         /* previous record, still in buffer? */
 806                         --index;
 807                         if (index < first_index)
 808                                 GOTO(out, rc = 0);
 809                         tail = (void *)tail - tail->lrt_len;
 810                 }
 811         }
 812
 813 out:
 814         if (buf != NULL)
 815                 OBD_FREE_LARGE(buf, chunk_size);
 816         RETURN(rc);
 817 }
 818 EXPORT_SYMBOL(llog_reverse_process);
 819
 820 /**
 821  * new llog API
 822  *
 823  * API functions:
 824  *      llog_open - open llog, may not exist
 825  *      llog_exist - check if llog exists
 826  *      llog_close - close opened llog, pair for open, frees llog_handle
 827  *      llog_declare_create - declare llog creation
 828  *      llog_create - create new llog on disk, need transaction handle
 829  *      llog_declare_write_rec - declaration of llog write
 830  *      llog_write_rec - write llog record on disk, need transaction handle
 831  *      llog_declare_add - declare llog catalog record addition
 832  *      llog_add - add llog record in catalog, need transaction handle
 833  */
 834 int llog_exist(struct llog_handle *loghandle)
 835 {
 836         struct llog_operations  *lop;
 837         int                      rc;
 838
 839         ENTRY;
 840
 841         rc = llog_handle2ops(loghandle, &lop);
 842         if (rc)
 843                 RETURN(rc);
 844         if (lop->lop_exist == NULL)
 845                 RETURN(-EOPNOTSUPP);
 846
 847         rc = lop->lop_exist(loghandle);
 848         RETURN(rc);
 849 }
 850 EXPORT_SYMBOL(llog_exist);
 851
 852 int llog_declare_create(const struct lu_env *env,
 853                         struct llog_handle *loghandle, struct thandle *th)
 854 {
 855         struct llog_operations  *lop;
 856         int                      raised, rc;
 857
 858         ENTRY;
 859
 860         rc = llog_handle2ops(loghandle, &lop);
 861         if (rc)
 862                 RETURN(rc);
 863         if (lop->lop_declare_create == NULL)
 864                 RETURN(-EOPNOTSUPP);
 865
 866         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 867         if (!raised)
 868                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 869         rc = lop->lop_declare_create(env, loghandle, th);
 870         if (!raised)
 871                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 872         RETURN(rc);
 873 }
 874
 875 int llog_create(const struct lu_env *env, struct llog_handle *handle,
 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         if (lop->lop_create == NULL)
 887                 RETURN(-EOPNOTSUPP);
 888
 889         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 890         if (!raised)
 891                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 892         rc = lop->lop_create(env, handle, th);
 893         if (!raised)
 894                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 895         RETURN(rc);
 896 }
 897
 898 int llog_declare_write_rec(const struct lu_env *env,
 899                            struct llog_handle *handle,
 900                            struct llog_rec_hdr *rec, int idx,
 901                            struct thandle *th)
 902 {
 903         struct llog_operations  *lop;
 904         int                      raised, rc;
 905
 906         ENTRY;
 907
 908         rc = llog_handle2ops(handle, &lop);
 909         if (rc)
 910                 RETURN(rc);
 911         LASSERT(lop);
 912         if (lop->lop_declare_write_rec == NULL)
 913                 RETURN(-EOPNOTSUPP);
 914
 915         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 916         if (!raised)
 917                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 918         rc = lop->lop_declare_write_rec(env, handle, rec, idx, th);
 919         if (!raised)
 920                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 921         RETURN(rc);
 922 }
 923
 924 int llog_write_rec(const struct lu_env *env, struct llog_handle *handle,
 925                    struct llog_rec_hdr *rec, struct llog_cookie *logcookies,
 926                    int idx, struct thandle *th)
 927 {
 928         struct llog_operations  *lop;
 929         int                      raised, rc, buflen;
 930
 931         ENTRY;
 932
 933         /* API sanity checks */
 934         if (handle == NULL) {
 935                 CERROR("loghandle is missed\n");
 936                 RETURN(-EPROTO);
 937         } else if (handle->lgh_obj == NULL) {
 938                 CERROR("loghandle %p with NULL object\n",
 939                         handle);
 940                 RETURN(-EPROTO);
 941         } else if (th == NULL) {
 942                 CERROR("%s: missed transaction handle\n",
 943                         handle->lgh_obj->do_lu.lo_dev->ld_obd->obd_name);
 944                 RETURN(-EPROTO);
 945         } else if (handle->lgh_hdr == NULL) {
 946                 CERROR("%s: loghandle %p with no header\n",
 947                         handle->lgh_obj->do_lu.lo_dev->ld_obd->obd_name,
 948                         handle);
 949                 RETURN(-EPROTO);
 950         }
 951
 952         rc = llog_handle2ops(handle, &lop);
 953         if (rc)
 954                 RETURN(rc);
 955
 956         if (lop->lop_write_rec == NULL)
 957                 RETURN(-EOPNOTSUPP);
 958
 959         buflen = rec->lrh_len;
 960         LASSERT(cfs_size_round(buflen) == buflen);
 961
 962         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 963         if (!raised)
 964                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 965         rc = lop->lop_write_rec(env, handle, rec, logcookies, idx, th);
 966         if (!raised)
 967                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 968         RETURN(rc);
 969 }
 970
 971 int llog_add(const struct lu_env *env, struct llog_handle *lgh,
 972              struct llog_rec_hdr *rec, struct llog_cookie *logcookies,
 973              struct thandle *th)
 974 {
 975         int raised, rc;
 976
 977         ENTRY;
 978
 979         if (lgh->lgh_logops->lop_add == NULL)
 980                 RETURN(-EOPNOTSUPP);
 981
 982         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 983         if (!raised)
 984                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 985         rc = lgh->lgh_logops->lop_add(env, lgh, rec, logcookies, th);
 986         if (!raised)
 987                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 988         RETURN(rc);
 989 }
 990 EXPORT_SYMBOL(llog_add);
 991
 992 int llog_declare_add(const struct lu_env *env, struct llog_handle *lgh,
 993                      struct llog_rec_hdr *rec, struct thandle *th)
 994 {
 995         int raised, rc;
 996
 997         ENTRY;
 998
 999         if (lgh->lgh_logops->lop_declare_add == NULL)
1000                 RETURN(-EOPNOTSUPP);
1001
1002         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
1003         if (!raised)
1004                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
1005         rc = lgh->lgh_logops->lop_declare_add(env, lgh, rec, th);
1006         if (!raised)
1007                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
1008         RETURN(rc);
1009 }
1010 EXPORT_SYMBOL(llog_declare_add);
1011
1012 /**
1013  * Helper function to open llog or create it if doesn't exist.
1014  * It hides all transaction handling from caller.
1015  */
1016 int llog_open_create(const struct lu_env *env, struct llog_ctxt *ctxt,
1017                      struct llog_handle **res, struct llog_logid *logid,
1018                      char *name)
1019 {
1020         struct dt_device        *d;
1021         struct thandle          *th;
1022         int                      rc;
1023
1024         ENTRY;
1025
1026         rc = llog_open(env, ctxt, res, logid, name, LLOG_OPEN_NEW);
1027         if (rc)
1028                 RETURN(rc);
1029
1030         if (llog_exist(*res))
1031                 RETURN(0);
1032
1033         LASSERT((*res)->lgh_obj != NULL);
1034
1035         d = lu2dt_dev((*res)->lgh_obj->do_lu.lo_dev);
1036
1037         th = dt_trans_create(env, d);
1038         if (IS_ERR(th))
1039                 GOTO(out, rc = PTR_ERR(th));
1040
1041         /* Create update llog object synchronously, which
1042          * happens during inialization process see
1043          * lod_sub_prep_llog(), to make sure the update
1044          * llog object is created before corss-MDT writing
1045          * updates into the llog object */
1046         if (ctxt->loc_flags & LLOG_CTXT_FLAG_NORMAL_FID)
1047                 th->th_sync = 1;
1048
1049         th->th_wait_submit = 1;
1050         rc = llog_declare_create(env, *res, th);
1051         if (rc == 0) {
1052                 rc = dt_trans_start_local(env, d, th);
1053                 if (rc == 0)
1054                         rc = llog_create(env, *res, th);
1055         }
1056         dt_trans_stop(env, d, th);
1057 out:
1058         if (rc)
1059                 llog_close(env, *res);
1060         RETURN(rc);
1061 }
1062 EXPORT_SYMBOL(llog_open_create);
1063
1064 /**
1065  * Helper function to delete existent llog.
1066  */
1067 int llog_erase(const struct lu_env *env, struct llog_ctxt *ctxt,
1068                struct llog_logid *logid, char *name)
1069 {
1070         struct llog_handle      *handle;
1071         int                      rc = 0, rc2;
1072
1073         ENTRY;
1074
1075         /* nothing to erase */
1076         if (name == NULL && logid == NULL)
1077                 RETURN(0);
1078
1079         rc = llog_open(env, ctxt, &handle, logid, name, LLOG_OPEN_EXISTS);
1080         if (rc < 0)
1081                 RETURN(rc);
1082
1083         rc = llog_init_handle(env, handle, LLOG_F_IS_PLAIN, NULL);
1084         if (rc == 0)
1085                 rc = llog_destroy(env, handle);
1086
1087         rc2 = llog_close(env, handle);
1088         if (rc == 0)
1089                 rc = rc2;
1090         RETURN(rc);
1091 }
1092 EXPORT_SYMBOL(llog_erase);
1093
1094 /*
1095  * Helper function for write record in llog.
1096  * It hides all transaction handling from caller.
1097  * Valid only with local llog.
1098  */
1099 int llog_write(const struct lu_env *env, struct llog_handle *loghandle,
1100                struct llog_rec_hdr *rec, int idx)
1101 {
1102         struct dt_device        *dt;
1103         struct thandle          *th;
1104         int                      rc;
1105
1106         ENTRY;
1107
1108         LASSERT(loghandle);
1109         LASSERT(loghandle->lgh_ctxt);
1110         LASSERT(loghandle->lgh_obj != NULL);
1111
1112         dt = lu2dt_dev(loghandle->lgh_obj->do_lu.lo_dev);
1113
1114         th = dt_trans_create(env, dt);
1115         if (IS_ERR(th))
1116                 RETURN(PTR_ERR(th));
1117
1118         rc = llog_declare_write_rec(env, loghandle, rec, idx, th);
1119         if (rc)
1120                 GOTO(out_trans, rc);
1121
1122         th->th_wait_submit = 1;
1123         rc = dt_trans_start_local(env, dt, th);
1124         if (rc)
1125                 GOTO(out_trans, rc);
1126
1127         down_write(&loghandle->lgh_lock);
1128         rc = llog_write_rec(env, loghandle, rec, NULL, idx, th);
1129         up_write(&loghandle->lgh_lock);
1130 out_trans:
1131         dt_trans_stop(env, dt, th);
1132         RETURN(rc);
1133 }
1134 EXPORT_SYMBOL(llog_write);
1135
1136 int llog_open(const struct lu_env *env, struct llog_ctxt *ctxt,
1137               struct llog_handle **lgh, struct llog_logid *logid,
1138               char *name, enum llog_open_param open_param)
1139 {
1140         int      raised;
1141         int      rc;
1142
1143         ENTRY;
1144
1145         LASSERT(ctxt);
1146         LASSERT(ctxt->loc_logops);
1147
1148         if (ctxt->loc_logops->lop_open == NULL) {
1149                 *lgh = NULL;
1150                 RETURN(-EOPNOTSUPP);
1151         }
1152
1153         *lgh = llog_alloc_handle();
1154         if (*lgh == NULL)
1155                 RETURN(-ENOMEM);
1156         (*lgh)->lgh_ctxt = ctxt;
1157         (*lgh)->lgh_logops = ctxt->loc_logops;
1158
1159         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
1160         if (!raised)
1161                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
1162         rc = ctxt->loc_logops->lop_open(env, *lgh, logid, name, open_param);
1163         if (!raised)
1164                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
1165         if (rc) {
1166                 llog_free_handle(*lgh);
1167                 *lgh = NULL;
1168         }
1169         RETURN(rc);
1170 }
1171 EXPORT_SYMBOL(llog_open);
1172
1173 int llog_close(const struct lu_env *env, struct llog_handle *loghandle)
1174 {
1175         struct llog_operations  *lop;
1176         int                      rc;
1177
1178         ENTRY;
1179
1180         rc = llog_handle2ops(loghandle, &lop);
1181         if (rc)
1182                 GOTO(out, rc);
1183         if (lop->lop_close == NULL)
1184                 GOTO(out, rc = -EOPNOTSUPP);
1185         rc = lop->lop_close(env, loghandle);
1186 out:
1187         llog_handle_put(loghandle);
1188         RETURN(rc);
1189 }
1190 EXPORT_SYMBOL(llog_close);
1191
1192 /**
1193  * Helper function to get the llog size in records. It is used by MGS
1194  * mostly to check that config llog exists and contains data.
1195  *
1196  * \param[in] env       execution environment
1197  * \param[in] ctxt      llog context
1198  * \param[in] name      llog name
1199  *
1200  * \retval              true if there are records in llog besides a header
1201  * \retval              false on error or llog without records
1202  */
1203 int llog_is_empty(const struct lu_env *env, struct llog_ctxt *ctxt,
1204                   char *name)
1205 {
1206         struct llog_handle      *llh;
1207         int                      rc = 0;
1208
1209         rc = llog_open(env, ctxt, &llh, NULL, name, LLOG_OPEN_EXISTS);
1210         if (rc < 0) {
1211                 if (likely(rc == -ENOENT))
1212                         rc = 0;
1213                 GOTO(out, rc);
1214         }
1215
1216         rc = llog_init_handle(env, llh, LLOG_F_IS_PLAIN, NULL);
1217         if (rc)
1218                 GOTO(out_close, rc);
1219         rc = llog_get_size(llh);
1220
1221 out_close:
1222         llog_close(env, llh);
1223 out:
1224         /* The header is record 1, the llog is still considered as empty
1225          * if there is only header */
1226         return (rc <= 1);
1227 }
1228 EXPORT_SYMBOL(llog_is_empty);
1229
1230 int llog_copy_handler(const struct lu_env *env, struct llog_handle *llh,
1231                       struct llog_rec_hdr *rec, void *data)
1232 {
1233         struct llog_handle      *copy_llh = data;
1234
1235         /* Append all records */
1236         return llog_write(env, copy_llh, rec, LLOG_NEXT_IDX);
1237 }
1238
1239 /* backup plain llog */
1240 int llog_backup(const struct lu_env *env, struct obd_device *obd,
1241                 struct llog_ctxt *ctxt, struct llog_ctxt *bctxt,
1242                 char *name, char *backup)
1243 {
1244         struct llog_handle      *llh, *bllh;
1245         int                      rc;
1246
1247         ENTRY;
1248
1249         /* open original log */
1250         rc = llog_open(env, ctxt, &llh, NULL, name, LLOG_OPEN_EXISTS);
1251         if (rc < 0) {
1252                 /* the -ENOENT case is also reported to the caller
1253                  * but silently so it should handle that if needed.
1254                  */
1255                 if (rc != -ENOENT)
1256                         CERROR("%s: failed to open log %s: rc = %d\n",
1257                                obd->obd_name, name, rc);
1258                 RETURN(rc);
1259         }
1260
1261         rc = llog_init_handle(env, llh, LLOG_F_IS_PLAIN, NULL);
1262         if (rc)
1263                 GOTO(out_close, rc);
1264
1265         /* Make sure there's no old backup log */
1266         rc = llog_erase(env, bctxt, NULL, backup);
1267         if (rc < 0 && rc != -ENOENT)
1268                 GOTO(out_close, rc);
1269
1270         /* open backup log */
1271         rc = llog_open_create(env, bctxt, &bllh, NULL, backup);
1272         if (rc) {
1273                 CERROR("%s: failed to open backup logfile %s: rc = %d\n",
1274                        obd->obd_name, backup, rc);
1275                 GOTO(out_close, rc);
1276         }
1277
1278         /* check that backup llog is not the same object as original one */
1279         if (llh->lgh_obj == bllh->lgh_obj) {
1280                 CERROR("%s: backup llog %s to itself (%s), objects %p/%p\n",
1281                        obd->obd_name, name, backup, llh->lgh_obj,
1282                        bllh->lgh_obj);
1283                 GOTO(out_backup, rc = -EEXIST);
1284         }
1285
1286         rc = llog_init_handle(env, bllh, LLOG_F_IS_PLAIN, NULL);
1287         if (rc)
1288                 GOTO(out_backup, rc);
1289
1290         /* Copy log record by record */
1291         rc = llog_process_or_fork(env, llh, llog_copy_handler, (void *)bllh,
1292                                   NULL, false);
1293         if (rc)
1294                 CERROR("%s: failed to backup log %s: rc = %d\n",
1295                        obd->obd_name, name, rc);
1296 out_backup:
1297         llog_close(env, bllh);
1298 out_close:
1299         llog_close(env, llh);
1300         RETURN(rc);
1301 }
1302 EXPORT_SYMBOL(llog_backup);
1303
1304 /* Get size of llog */
1305 __u64 llog_size(const struct lu_env *env, struct llog_handle *llh)
1306 {
1307         int rc;
1308         struct lu_attr la;
1309
1310         rc = llh->lgh_obj->do_ops->do_attr_get(env, llh->lgh_obj, &la);
1311         if (rc) {
1312                 CERROR("%s: attr_get failed, rc = %d\n",
1313                        llh->lgh_ctxt->loc_obd->obd_name, rc);
1314                 return 0;
1315         }
1316
1317         return la.la_size;
1318 }
1319 EXPORT_SYMBOL(llog_size);
1320