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, 2017, 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;
 200         struct thandle          *th;
 201         __u32                    tmp_lgc_index;
 202         int                      rc;
 203         int rc1;
 204         bool subtract_count = false;
 205
 206         ENTRY;
 207
 208         LASSERT(loghandle != NULL);
 209         LASSERT(loghandle->lgh_ctxt != NULL);
 210         LASSERT(loghandle->lgh_obj != NULL);
 211
 212         llh = loghandle->lgh_hdr;
 213
 214         CDEBUG(D_RPCTRACE, "Canceling %d in log "DFID"\n", index,
 215                PFID(&loghandle->lgh_id.lgl_oi.oi_fid));
 216
 217         if (index == 0) {
 218                 CERROR("Can't cancel index 0 which is header\n");
 219                 RETURN(-EINVAL);
 220         }
 221
 222         dt = lu2dt_dev(loghandle->lgh_obj->do_lu.lo_dev);
 223
 224         th = dt_trans_create(env, dt);
 225         if (IS_ERR(th))
 226                 RETURN(PTR_ERR(th));
 227
 228         rc = llog_declare_write_rec(env, loghandle, &llh->llh_hdr, index, th);
 229         if (rc < 0)
 230                 GOTO(out_trans, rc);
 231
 232         if ((llh->llh_flags & LLOG_F_ZAP_WHEN_EMPTY)) {
 233                 rc = llog_declare_destroy(env, loghandle, th);
 234                 if (rc < 0)
 235                         GOTO(out_trans, rc);
 236         }
 237
 238         th->th_wait_submit = 1;
 239         rc = dt_trans_start_local(env, dt, th);
 240         if (rc < 0)
 241                 GOTO(out_trans, rc);
 242
 243         down_write(&loghandle->lgh_lock);
 244         /* clear bitmap */
 245         mutex_lock(&loghandle->lgh_hdr_mutex);
 246         if (!ext2_clear_bit(index, LLOG_HDR_BITMAP(llh))) {
 247                 CDEBUG(D_RPCTRACE, "Catalog index %u already clear?\n", index);
 248                 GOTO(out_unlock, rc);
 249         }
 250
 251         loghandle->lgh_hdr->llh_count--;
 252         subtract_count = true;
 253
 254         /* Since llog_process_thread use lgi_cookie, it`s better to save them
 255          * and restore after using
 256          */
 257         tmp_lgc_index = lgi->lgi_cookie.lgc_index;
 258         /* Pass this index to llog_osd_write_rec(), which will use the index
 259          * to only update the necesary bitmap. */
 260         lgi->lgi_cookie.lgc_index = index;
 261         /* update header */
 262         rc = llog_write_rec(env, loghandle, &llh->llh_hdr, &lgi->lgi_cookie,
 263                             LLOG_HEADER_IDX, th);
 264         lgi->lgi_cookie.lgc_index = tmp_lgc_index;
 265
 266         if (rc != 0)
 267                 GOTO(out_unlock, rc);
 268
 269         if ((llh->llh_flags & LLOG_F_ZAP_WHEN_EMPTY) &&
 270             (llh->llh_count == 1) &&
 271             ((loghandle->lgh_last_idx == LLOG_HDR_BITMAP_SIZE(llh) - 1) ||
 272              (loghandle->u.phd.phd_cat_handle != NULL &&
 273               loghandle->u.phd.phd_cat_handle->u.chd.chd_current_log !=
 274                 loghandle))) {
 275                 /* never try to destroy it again */
 276                 llh->llh_flags &= ~LLOG_F_ZAP_WHEN_EMPTY;
 277                 rc = llog_trans_destroy(env, loghandle, th);
 278                 if (rc < 0) {
 279                         /* Sigh, can not destroy the final plain llog, but
 280                          * the bitmap has been clearly, so the record can not
 281                          * be accessed anymore, let's return 0 for now, and
 282                          * the orphan will be handled by LFSCK. */
 283                         CERROR("%s: can't destroy empty llog "DFID": rc = %d\n",
 284                                loghandle->lgh_ctxt->loc_obd->obd_name,
 285                                PFID(&loghandle->lgh_id.lgl_oi.oi_fid), rc);
 286                         GOTO(out_unlock, rc = 0);
 287                 }
 288                 rc = LLOG_DEL_PLAIN;
 289         }
 290
 291 out_unlock:
 292         mutex_unlock(&loghandle->lgh_hdr_mutex);
 293         up_write(&loghandle->lgh_lock);
 294 out_trans:
 295         rc1 = dt_trans_stop(env, dt, th);
 296         if (rc == 0)
 297                 rc = rc1;
 298         if (rc < 0 && subtract_count) {
 299                 mutex_lock(&loghandle->lgh_hdr_mutex);
 300                 loghandle->lgh_hdr->llh_count++;
 301                 ext2_set_bit(index, LLOG_HDR_BITMAP(llh));
 302                 mutex_unlock(&loghandle->lgh_hdr_mutex);
 303         }
 304         RETURN(rc);
 305 }
 306
 307 int llog_read_header(const struct lu_env *env, struct llog_handle *handle,
 308                      const struct obd_uuid *uuid)
 309 {
 310         struct llog_operations *lop;
 311         int rc;
 312         ENTRY;
 313
 314         rc = llog_handle2ops(handle, &lop);
 315         if (rc)
 316                 RETURN(rc);
 317
 318         if (lop->lop_read_header == NULL)
 319                 RETURN(-EOPNOTSUPP);
 320
 321         rc = lop->lop_read_header(env, handle);
 322         if (rc == LLOG_EEMPTY) {
 323                 struct llog_log_hdr *llh = handle->lgh_hdr;
 324
 325                 /* lrh_len should be initialized in llog_init_handle */
 326                 handle->lgh_last_idx = 0; /* header is record with index 0 */
 327                 llh->llh_count = 1;         /* for the header record */
 328                 llh->llh_hdr.lrh_type = LLOG_HDR_MAGIC;
 329                 LASSERT(handle->lgh_ctxt->loc_chunk_size >=
 330                                                 LLOG_MIN_CHUNK_SIZE);
 331                 llh->llh_hdr.lrh_len = handle->lgh_ctxt->loc_chunk_size;
 332                 llh->llh_hdr.lrh_index = 0;
 333                 llh->llh_timestamp = ktime_get_real_seconds();
 334                 if (uuid)
 335                         memcpy(&llh->llh_tgtuuid, uuid,
 336                                sizeof(llh->llh_tgtuuid));
 337                 llh->llh_bitmap_offset = offsetof(typeof(*llh), llh_bitmap);
 338                 /* Since update llog header might also call this function,
 339                  * let's reset the bitmap to 0 here */
 340                 memset(LLOG_HDR_BITMAP(llh), 0, llh->llh_hdr.lrh_len -
 341                                                 llh->llh_bitmap_offset -
 342                                                 sizeof(llh->llh_tail));
 343                 ext2_set_bit(0, LLOG_HDR_BITMAP(llh));
 344                 LLOG_HDR_TAIL(llh)->lrt_len = llh->llh_hdr.lrh_len;
 345                 LLOG_HDR_TAIL(llh)->lrt_index = llh->llh_hdr.lrh_index;
 346                 rc = 0;
 347         }
 348         RETURN(rc);
 349 }
 350 EXPORT_SYMBOL(llog_read_header);
 351
 352 int llog_init_handle(const struct lu_env *env, struct llog_handle *handle,
 353                      int flags, struct obd_uuid *uuid)
 354 {
 355         struct llog_log_hdr     *llh;
 356         enum llog_flag           fmt = flags & LLOG_F_EXT_MASK;
 357         int                      rc;
 358         int                     chunk_size = handle->lgh_ctxt->loc_chunk_size;
 359         ENTRY;
 360
 361         LASSERT(handle->lgh_hdr == NULL);
 362
 363         LASSERT(chunk_size >= LLOG_MIN_CHUNK_SIZE);
 364         OBD_ALLOC_LARGE(llh, chunk_size);
 365         if (llh == NULL)
 366                 RETURN(-ENOMEM);
 367
 368         handle->lgh_hdr = llh;
 369         handle->lgh_hdr_size = chunk_size;
 370         /* first assign flags to use llog_client_ops */
 371         llh->llh_flags = flags;
 372         rc = llog_read_header(env, handle, uuid);
 373         if (rc == 0) {
 374                 if (unlikely((llh->llh_flags & LLOG_F_IS_PLAIN &&
 375                               flags & LLOG_F_IS_CAT) ||
 376                              (llh->llh_flags & LLOG_F_IS_CAT &&
 377                               flags & LLOG_F_IS_PLAIN))) {
 378                         CERROR("%s: llog type is %s but initializing %s\n",
 379                                handle->lgh_ctxt->loc_obd->obd_name,
 380                                llh->llh_flags & LLOG_F_IS_CAT ?
 381                                "catalog" : "plain",
 382                                flags & LLOG_F_IS_CAT ? "catalog" : "plain");
 383                         GOTO(out, rc = -EINVAL);
 384                 } else if (llh->llh_flags &
 385                            (LLOG_F_IS_PLAIN | LLOG_F_IS_CAT)) {
 386                         /*
 387                          * it is possible to open llog without specifying llog
 388                          * type so it is taken from llh_flags
 389                          */
 390                         flags = llh->llh_flags;
 391                 } else {
 392                         /* for some reason the llh_flags has no type set */
 393                         CERROR("llog type is not specified!\n");
 394                         GOTO(out, rc = -EINVAL);
 395                 }
 396                 if (unlikely(uuid &&
 397                              !obd_uuid_equals(uuid, &llh->llh_tgtuuid))) {
 398                         CERROR("%s: llog uuid mismatch: %s/%s\n",
 399                                handle->lgh_ctxt->loc_obd->obd_name,
 400                                (char *)uuid->uuid,
 401                                (char *)llh->llh_tgtuuid.uuid);
 402                         GOTO(out, rc = -EEXIST);
 403                 }
 404         }
 405         if (flags & LLOG_F_IS_CAT) {
 406                 LASSERT(list_empty(&handle->u.chd.chd_head));
 407                 INIT_LIST_HEAD(&handle->u.chd.chd_head);
 408                 llh->llh_size = sizeof(struct llog_logid_rec);
 409                 llh->llh_flags |= LLOG_F_IS_FIXSIZE;
 410         } else if (!(flags & LLOG_F_IS_PLAIN)) {
 411                 CERROR("%s: unknown flags: %#x (expected %#x or %#x)\n",
 412                        handle->lgh_ctxt->loc_obd->obd_name,
 413                        flags, LLOG_F_IS_CAT, LLOG_F_IS_PLAIN);
 414                 rc = -EINVAL;
 415         }
 416         llh->llh_flags |= fmt;
 417 out:
 418         if (rc) {
 419                 OBD_FREE_LARGE(llh, chunk_size);
 420                 handle->lgh_hdr = NULL;
 421         }
 422         RETURN(rc);
 423 }
 424 EXPORT_SYMBOL(llog_init_handle);
 425
 426 static int llog_process_thread(void *arg)
 427 {
 428         struct llog_process_info        *lpi = arg;
 429         struct llog_handle              *loghandle = lpi->lpi_loghandle;
 430         struct llog_log_hdr             *llh = loghandle->lgh_hdr;
 431         struct llog_process_cat_data    *cd  = lpi->lpi_catdata;
 432         struct llog_thread_info         *lti;
 433         char                            *buf;
 434         size_t                           chunk_size;
 435         __u64                            cur_offset;
 436         int                              rc = 0, index = 1, last_index;
 437         int                              saved_index = 0;
 438         int                              last_called_index = 0;
 439         bool                             repeated = false;
 440
 441         ENTRY;
 442
 443         if (llh == NULL)
 444                 RETURN(-EINVAL);
 445
 446         lti = lpi->lpi_env == NULL ? NULL : llog_info(lpi->lpi_env);
 447
 448         cur_offset = chunk_size = llh->llh_hdr.lrh_len;
 449         /* expect chunk_size to be power of two */
 450         LASSERT(is_power_of_2(chunk_size));
 451
 452         OBD_ALLOC_LARGE(buf, chunk_size);
 453         if (buf == NULL) {
 454                 lpi->lpi_rc = -ENOMEM;
 455                 RETURN(0);
 456         }
 457
 458         if (cd != NULL) {
 459                 last_called_index = cd->lpcd_first_idx;
 460                 index = cd->lpcd_first_idx + 1;
 461         }
 462         if (cd != NULL && cd->lpcd_last_idx)
 463                 last_index = cd->lpcd_last_idx;
 464         else
 465                 last_index = LLOG_HDR_BITMAP_SIZE(llh) - 1;
 466
 467         while (rc == 0) {
 468                 struct llog_rec_hdr *rec;
 469                 off_t chunk_offset = 0;
 470                 unsigned int buf_offset = 0;
 471                 bool partial_chunk;
 472                 int     lh_last_idx;
 473
 474                 /* skip records not set in bitmap */
 475                 while (index <= last_index &&
 476                        !ext2_test_bit(index, LLOG_HDR_BITMAP(llh)))
 477                         ++index;
 478
 479                 /* There are no indices prior the last_index */
 480                 if (index > last_index)
 481                         break;
 482
 483                 CDEBUG(D_OTHER, "index: %d last_index %d\n", index,
 484                        last_index);
 485
 486 repeat:
 487                 /* get the buf with our target record; avoid old garbage */
 488                 memset(buf, 0, chunk_size);
 489                 /* the record index for outdated chunk data */
 490                 lh_last_idx = loghandle->lgh_last_idx + 1;
 491                 rc = llog_next_block(lpi->lpi_env, loghandle, &saved_index,
 492                                      index, &cur_offset, buf, chunk_size);
 493                 if (repeated && rc)
 494                         CDEBUG(D_OTHER, "cur_offset %llu, chunk_offset %llu,"
 495                                " buf_offset %u, rc = %d\n", cur_offset,
 496                                (__u64)chunk_offset, buf_offset, rc);
 497                 /* we`ve tried to reread the chunk, but there is no
 498                  * new records */
 499                 if (rc == -EIO && repeated && (chunk_offset + buf_offset) ==
 500                     cur_offset)
 501                         GOTO(out, rc = 0);
 502                 if (rc != 0)
 503                         GOTO(out, rc);
 504
 505                 /* NB: after llog_next_block() call the cur_offset is the
 506                  * offset of the next block after read one.
 507                  * The absolute offset of the current chunk is calculated
 508                  * from cur_offset value and stored in chunk_offset variable.
 509                  */
 510                 if ((cur_offset & (chunk_size - 1)) != 0) {
 511                         partial_chunk = true;
 512                         chunk_offset = cur_offset & ~(chunk_size - 1);
 513                 } else {
 514                         partial_chunk = false;
 515                         chunk_offset = cur_offset - chunk_size;
 516                 }
 517
 518                 /* NB: when rec->lrh_len is accessed it is already swabbed
 519                  * since it is used at the "end" of the loop and the rec
 520                  * swabbing is done at the beginning of the loop. */
 521                 for (rec = (struct llog_rec_hdr *)(buf + buf_offset);
 522                      (char *)rec < buf + chunk_size;
 523                      rec = llog_rec_hdr_next(rec)) {
 524
 525                         CDEBUG(D_OTHER, "processing rec 0x%p type %#x\n",
 526                                rec, rec->lrh_type);
 527
 528                         if (LLOG_REC_HDR_NEEDS_SWABBING(rec))
 529                                 lustre_swab_llog_rec(rec);
 530
 531                         CDEBUG(D_OTHER, "after swabbing, type=%#x idx=%d\n",
 532                                rec->lrh_type, rec->lrh_index);
 533
 534                         /* for partial chunk the end of it is zeroed, check
 535                          * for index 0 to distinguish it. */
 536                         if (partial_chunk && rec->lrh_index == 0) {
 537                                 /* concurrent llog_add() might add new records
 538                                  * while llog_processing, check this is not
 539                                  * the case and re-read the current chunk
 540                                  * otherwise. */
 541                                 int records;
 542                                 /* lgh_last_idx could be less then index
 543                                  * for catalog, if catalog is wrapped */
 544                                 if ((index > loghandle->lgh_last_idx &&
 545                                     !(loghandle->lgh_hdr->llh_flags &
 546                                       LLOG_F_IS_CAT)) || repeated ||
 547                                     (loghandle->lgh_obj != NULL &&
 548                                      dt_object_remote(loghandle->lgh_obj)))
 549                                         GOTO(out, rc = 0);
 550                                 /* <2 records means no more records
 551                                  * if the last record we processed was
 552                                  * the final one, then the underlying
 553                                  * object might have been destroyed yet.
 554                                  * we better don't access that.. */
 555                                 mutex_lock(&loghandle->lgh_hdr_mutex);
 556                                 records = loghandle->lgh_hdr->llh_count;
 557                                 mutex_unlock(&loghandle->lgh_hdr_mutex);
 558                                 if (records <= 1)
 559                                         GOTO(out, rc = 0);
 560                                 CDEBUG(D_OTHER, "Re-read last llog buffer for "
 561                                        "new records, index %u, last %u\n",
 562                                        index, loghandle->lgh_last_idx);
 563                                 /* save offset inside buffer for the re-read */
 564                                 buf_offset = (char *)rec - (char *)buf;
 565                                 cur_offset = chunk_offset;
 566                                 repeated = true;
 567                                 goto repeat;
 568                         }
 569
 570                         repeated = false;
 571
 572                         if (rec->lrh_len == 0 || rec->lrh_len > chunk_size) {
 573                                 CWARN("%s: invalid length %d in llog "DFID
 574                                       "record for index %d/%d\n",
 575                                        loghandle->lgh_ctxt->loc_obd->obd_name,
 576                                        rec->lrh_len,
 577                                        PFID(&loghandle->lgh_id.lgl_oi.oi_fid),
 578                                        rec->lrh_index, index);
 579
 580                                 GOTO(out, rc = -EINVAL);
 581                         }
 582
 583                         if (rec->lrh_index < index) {
 584                                 CDEBUG(D_OTHER, "skipping lrh_index %d\n",
 585                                        rec->lrh_index);
 586                                 continue;
 587                         }
 588
 589                         if (rec->lrh_index != index) {
 590                                 CERROR("%s: "DFID" Invalid record: index %u"
 591                                        " but expected %u\n",
 592                                        loghandle->lgh_ctxt->loc_obd->obd_name,
 593                                        PFID(&loghandle->lgh_id.lgl_oi.oi_fid),
 594                                        rec->lrh_index, index);
 595                                 GOTO(out, rc = -ERANGE);
 596                         }
 597
 598                         CDEBUG(D_OTHER,
 599                                "lrh_index: %d lrh_len: %d (%d remains)\n",
 600                                rec->lrh_index, rec->lrh_len,
 601                                (int)(buf + chunk_size - (char *)rec));
 602
 603                         /* lgh_cur_offset is used only at llog_test_3 */
 604                         loghandle->lgh_cur_offset = (char *)rec - (char *)buf +
 605                                                     chunk_offset;
 606
 607                         /* if set, process the callback on this record */
 608                         if (ext2_test_bit(index, LLOG_HDR_BITMAP(llh))) {
 609                                 struct llog_cookie *lgc;
 610                                 __u64   tmp_off;
 611                                 int     tmp_idx;
 612                         /* the bitmap could be changed during processing
 613                          * records from the chunk. For wrapped catalog
 614                          * it means we can read deleted record and try to
 615                          * process it. Check this case and reread the chunk.
 616                          * Checking the race with llog_add the bit is set
 617                          * after incrementation of lgh_last_idx */
 618                                 if (index == lh_last_idx &&
 619                                     lh_last_idx !=
 620                                     (loghandle->lgh_last_idx + 1)) {
 621                                         /* save offset inside buffer for
 622                                          *  the re-read */
 623                                         buf_offset = (char *)rec - (char *)buf;
 624                                         cur_offset = chunk_offset;
 625                                         repeated = true;
 626                                         goto repeat;
 627
 628                                 }
 629                                 if (lti != NULL) {
 630                                         lgc = &lti->lgi_cookie;
 631                                         /* store lu_env for recursive calls */
 632                                         tmp_off = lgc->lgc_offset;
 633                                         tmp_idx = lgc->lgc_index;
 634
 635                                         lgc->lgc_offset = (char *)rec -
 636                                                 (char *)buf + chunk_offset;
 637                                         lgc->lgc_index = rec->lrh_index;
 638                                 }
 639                                 /* using lu_env for passing record offset to
 640                                  * llog_write through various callbacks */
 641                                 rc = lpi->lpi_cb(lpi->lpi_env, loghandle, rec,
 642                                                  lpi->lpi_cbdata);
 643                                 last_called_index = index;
 644
 645                                 if (lti != NULL) {
 646                                         lgc->lgc_offset = tmp_off;
 647                                         lgc->lgc_index = tmp_idx;
 648                                 }
 649
 650                                 if (rc == LLOG_PROC_BREAK) {
 651                                         GOTO(out, rc);
 652                                 } else if (rc == LLOG_DEL_RECORD) {
 653                                         rc = llog_cancel_rec(lpi->lpi_env,
 654                                                              loghandle,
 655                                                              rec->lrh_index);
 656                                 }
 657                                 if (rc)
 658                                         GOTO(out, rc);
 659                                 /* some stupid callbacks directly cancel records
 660                                  * and delete llog. Check it and stop
 661                                  * processing. */
 662                                 if (loghandle->lgh_hdr == NULL ||
 663                                     loghandle->lgh_hdr->llh_count == 1)
 664                                         GOTO(out, rc = 0);
 665                         }
 666                         /* exit if the last index is reached */
 667                         if (index >= last_index)
 668                                 GOTO(out, rc = 0);
 669                         ++index;
 670                 }
 671         }
 672
 673 out:
 674         if (cd != NULL)
 675                 cd->lpcd_last_idx = last_called_index;
 676
 677         if (unlikely(rc == -EIO && loghandle->lgh_obj != NULL)) {
 678                 if (dt_object_remote(loghandle->lgh_obj)) {
 679                         /* If it is remote object, then -EIO might means
 680                          * disconnection or eviction, let's return -EAGAIN,
 681                          * so for update recovery log processing, it will
 682                          * retry until the umount or abort recovery, see
 683                          * lod_sub_recovery_thread() */
 684                         CERROR("%s retry remote llog process\n",
 685                                loghandle->lgh_ctxt->loc_obd->obd_name);
 686                         rc = -EAGAIN;
 687                 } else {
 688                         /* something bad happened to the processing of a local
 689                          * llog file, probably I/O error or the log got
 690                          * corrupted to be able to finally release the log we
 691                          * discard any remaining bits in the header */
 692                         CERROR("%s: Local llog found corrupted #"DOSTID":%x"
 693                                " %s index %d count %d\n",
 694                                loghandle->lgh_ctxt->loc_obd->obd_name,
 695                                POSTID(&loghandle->lgh_id.lgl_oi),
 696                                loghandle->lgh_id.lgl_ogen,
 697                                ((llh->llh_flags & LLOG_F_IS_CAT) ? "catalog" :
 698                                 "plain"), index, llh->llh_count);
 699
 700                         while (index <= last_index) {
 701                                 if (ext2_test_bit(index,
 702                                                   LLOG_HDR_BITMAP(llh)) != 0)
 703                                         llog_cancel_rec(lpi->lpi_env, loghandle,
 704                                                         index);
 705                                 index++;
 706                         }
 707                         rc = 0;
 708                 }
 709         }
 710
 711         OBD_FREE_LARGE(buf, chunk_size);
 712         lpi->lpi_rc = rc;
 713         return 0;
 714 }
 715
 716 static int llog_process_thread_daemonize(void *arg)
 717 {
 718         struct llog_process_info        *lpi = arg;
 719         struct lu_env                    env;
 720         int                              rc;
 721         struct nsproxy                  *new_ns, *curr_ns = current->nsproxy;
 722
 723         task_lock(lpi->lpi_reftask);
 724         new_ns = lpi->lpi_reftask->nsproxy;
 725         if (curr_ns != new_ns) {
 726                 get_nsproxy(new_ns);
 727
 728                 current->nsproxy = new_ns;
 729                 /* XXX: we should call put_nsproxy() instead of
 730                  * atomic_dec(&ns->count) directly. But put_nsproxy() cannot be
 731                  * used outside of the kernel itself, because it calls
 732                  * free_nsproxy() which is not exported by the kernel
 733                  * (defined in kernel/nsproxy.c) */
 734                 atomic_dec(&curr_ns->count);
 735         }
 736         task_unlock(lpi->lpi_reftask);
 737
 738         unshare_fs_struct();
 739
 740         /* client env has no keys, tags is just 0 */
 741         rc = lu_env_init(&env, LCT_LOCAL | LCT_MG_THREAD);
 742         if (rc)
 743                 goto out;
 744         lpi->lpi_env = &env;
 745
 746         rc = llog_process_thread(arg);
 747
 748         lu_env_fini(&env);
 749 out:
 750         complete(&lpi->lpi_completion);
 751         return rc;
 752 }
 753
 754 int llog_process_or_fork(const struct lu_env *env,
 755                          struct llog_handle *loghandle,
 756                          llog_cb_t cb, void *data, void *catdata, bool fork)
 757 {
 758         struct llog_process_info *lpi;
 759         int                      rc;
 760
 761         ENTRY;
 762
 763         OBD_ALLOC_PTR(lpi);
 764         if (lpi == NULL) {
 765                 CERROR("cannot alloc pointer\n");
 766                 RETURN(-ENOMEM);
 767         }
 768         lpi->lpi_loghandle = loghandle;
 769         lpi->lpi_cb        = cb;
 770         lpi->lpi_cbdata    = data;
 771         lpi->lpi_catdata   = catdata;
 772
 773         if (fork) {
 774                 struct task_struct *task;
 775
 776                 /* The new thread can't use parent env,
 777                  * init the new one in llog_process_thread_daemonize. */
 778                 lpi->lpi_env = NULL;
 779                 init_completion(&lpi->lpi_completion);
 780                 /* take reference to current, so that
 781                  * llog_process_thread_daemonize() can use it to switch to
 782                  * namespace associated with current  */
 783                 lpi->lpi_reftask = current;
 784                 task = kthread_run(llog_process_thread_daemonize, lpi,
 785                                    "llog_process_thread");
 786                 if (IS_ERR(task)) {
 787                         rc = PTR_ERR(task);
 788                         CERROR("%s: cannot start thread: rc = %d\n",
 789                                loghandle->lgh_ctxt->loc_obd->obd_name, rc);
 790                         GOTO(out_lpi, rc);
 791                 }
 792                 wait_for_completion(&lpi->lpi_completion);
 793         } else {
 794                 lpi->lpi_env = env;
 795                 llog_process_thread(lpi);
 796         }
 797         rc = lpi->lpi_rc;
 798
 799 out_lpi:
 800         OBD_FREE_PTR(lpi);
 801         RETURN(rc);
 802 }
 803 EXPORT_SYMBOL(llog_process_or_fork);
 804
 805 int llog_process(const struct lu_env *env, struct llog_handle *loghandle,
 806                  llog_cb_t cb, void *data, void *catdata)
 807 {
 808         int rc;
 809         rc = llog_process_or_fork(env, loghandle, cb, data, catdata, true);
 810         return rc == LLOG_DEL_PLAIN ? 0 : rc;
 811 }
 812 EXPORT_SYMBOL(llog_process);
 813
 814 int llog_reverse_process(const struct lu_env *env,
 815                          struct llog_handle *loghandle, llog_cb_t cb,
 816                          void *data, void *catdata)
 817 {
 818         struct llog_log_hdr *llh = loghandle->lgh_hdr;
 819         struct llog_process_cat_data *cd = catdata;
 820         void *buf;
 821         int rc = 0, first_index = 1, index, idx;
 822         __u32   chunk_size = llh->llh_hdr.lrh_len;
 823         ENTRY;
 824
 825         OBD_ALLOC_LARGE(buf, chunk_size);
 826         if (buf == NULL)
 827                 RETURN(-ENOMEM);
 828
 829         if (cd != NULL)
 830                 first_index = cd->lpcd_first_idx + 1;
 831         if (cd != NULL && cd->lpcd_last_idx)
 832                 index = cd->lpcd_last_idx;
 833         else
 834                 index = LLOG_HDR_BITMAP_SIZE(llh) - 1;
 835
 836         while (rc == 0) {
 837                 struct llog_rec_hdr *rec;
 838                 struct llog_rec_tail *tail;
 839
 840                 /* skip records not set in bitmap */
 841                 while (index >= first_index &&
 842                        !ext2_test_bit(index, LLOG_HDR_BITMAP(llh)))
 843                         --index;
 844
 845                 LASSERT(index >= first_index - 1);
 846                 if (index == first_index - 1)
 847                         break;
 848
 849                 /* get the buf with our target record; avoid old garbage */
 850                 memset(buf, 0, chunk_size);
 851                 rc = llog_prev_block(env, loghandle, index, buf, chunk_size);
 852                 if (rc)
 853                         GOTO(out, rc);
 854
 855                 rec = buf;
 856                 idx = rec->lrh_index;
 857                 CDEBUG(D_RPCTRACE, "index %u : idx %u\n", index, idx);
 858                 while (idx < index) {
 859                         rec = (void *)rec + rec->lrh_len;
 860                         if (LLOG_REC_HDR_NEEDS_SWABBING(rec))
 861                                 lustre_swab_llog_rec(rec);
 862                         idx ++;
 863                 }
 864                 LASSERT(idx == index);
 865                 tail = (void *)rec + rec->lrh_len - sizeof(*tail);
 866
 867                 /* process records in buffer, starting where we found one */
 868                 while ((void *)tail > buf) {
 869                         if (tail->lrt_index == 0)
 870                                 GOTO(out, rc = 0); /* no more records */
 871
 872                         /* if set, process the callback on this record */
 873                         if (ext2_test_bit(index, LLOG_HDR_BITMAP(llh))) {
 874                                 rec = (void *)tail - tail->lrt_len +
 875                                       sizeof(*tail);
 876
 877                                 rc = cb(env, loghandle, rec, data);
 878                                 if (rc == LLOG_PROC_BREAK) {
 879                                         GOTO(out, rc);
 880                                 } else if (rc == LLOG_DEL_RECORD) {
 881                                         rc = llog_cancel_rec(env, loghandle,
 882                                                              tail->lrt_index);
 883                                 }
 884                                 if (rc)
 885                                         GOTO(out, rc);
 886                         }
 887
 888                         /* previous record, still in buffer? */
 889                         --index;
 890                         if (index < first_index)
 891                                 GOTO(out, rc = 0);
 892                         tail = (void *)tail - tail->lrt_len;
 893                 }
 894         }
 895
 896 out:
 897         if (buf != NULL)
 898                 OBD_FREE_LARGE(buf, chunk_size);
 899         RETURN(rc);
 900 }
 901 EXPORT_SYMBOL(llog_reverse_process);
 902
 903 /**
 904  * new llog API
 905  *
 906  * API functions:
 907  *      llog_open - open llog, may not exist
 908  *      llog_exist - check if llog exists
 909  *      llog_close - close opened llog, pair for open, frees llog_handle
 910  *      llog_declare_create - declare llog creation
 911  *      llog_create - create new llog on disk, need transaction handle
 912  *      llog_declare_write_rec - declaration of llog write
 913  *      llog_write_rec - write llog record on disk, need transaction handle
 914  *      llog_declare_add - declare llog catalog record addition
 915  *      llog_add - add llog record in catalog, need transaction handle
 916  */
 917 int llog_exist(struct llog_handle *loghandle)
 918 {
 919         struct llog_operations  *lop;
 920         int                      rc;
 921
 922         ENTRY;
 923
 924         rc = llog_handle2ops(loghandle, &lop);
 925         if (rc)
 926                 RETURN(rc);
 927         if (lop->lop_exist == NULL)
 928                 RETURN(-EOPNOTSUPP);
 929
 930         rc = lop->lop_exist(loghandle);
 931         RETURN(rc);
 932 }
 933 EXPORT_SYMBOL(llog_exist);
 934
 935 int llog_declare_create(const struct lu_env *env,
 936                         struct llog_handle *loghandle, struct thandle *th)
 937 {
 938         struct llog_operations  *lop;
 939         int                      raised, rc;
 940
 941         ENTRY;
 942
 943         rc = llog_handle2ops(loghandle, &lop);
 944         if (rc)
 945                 RETURN(rc);
 946         if (lop->lop_declare_create == NULL)
 947                 RETURN(-EOPNOTSUPP);
 948
 949         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 950         if (!raised)
 951                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 952         rc = lop->lop_declare_create(env, loghandle, th);
 953         if (!raised)
 954                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 955         RETURN(rc);
 956 }
 957
 958 int llog_create(const struct lu_env *env, struct llog_handle *handle,
 959                 struct thandle *th)
 960 {
 961         struct llog_operations  *lop;
 962         int                      raised, rc;
 963
 964         ENTRY;
 965
 966         rc = llog_handle2ops(handle, &lop);
 967         if (rc)
 968                 RETURN(rc);
 969         if (lop->lop_create == NULL)
 970                 RETURN(-EOPNOTSUPP);
 971
 972         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 973         if (!raised)
 974                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 975         rc = lop->lop_create(env, handle, th);
 976         if (!raised)
 977                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 978         RETURN(rc);
 979 }
 980
 981 int llog_declare_write_rec(const struct lu_env *env,
 982                            struct llog_handle *handle,
 983                            struct llog_rec_hdr *rec, int idx,
 984                            struct thandle *th)
 985 {
 986         struct llog_operations  *lop;
 987         int                      raised, rc;
 988
 989         ENTRY;
 990
 991         rc = llog_handle2ops(handle, &lop);
 992         if (rc)
 993                 RETURN(rc);
 994         LASSERT(lop);
 995         if (lop->lop_declare_write_rec == 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 = lop->lop_declare_write_rec(env, handle, rec, idx, th);
1002         if (!raised)
1003                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
1004         RETURN(rc);
1005 }
1006
1007 int llog_write_rec(const struct lu_env *env, struct llog_handle *handle,
1008                    struct llog_rec_hdr *rec, struct llog_cookie *logcookies,
1009                    int idx, struct thandle *th)
1010 {
1011         struct llog_operations  *lop;
1012         int                      raised, rc, buflen;
1013
1014         ENTRY;
1015
1016         /* API sanity checks */
1017         if (handle == NULL) {
1018                 CERROR("loghandle is missed\n");
1019                 RETURN(-EPROTO);
1020         } else if (handle->lgh_obj == NULL) {
1021                 CERROR("loghandle %p with NULL object\n",
1022                         handle);
1023                 RETURN(-EPROTO);
1024         } else if (th == NULL) {
1025                 CERROR("%s: missed transaction handle\n",
1026                         handle->lgh_obj->do_lu.lo_dev->ld_obd->obd_name);
1027                 RETURN(-EPROTO);
1028         } else if (handle->lgh_hdr == NULL) {
1029                 CERROR("%s: loghandle %p with no header\n",
1030                         handle->lgh_obj->do_lu.lo_dev->ld_obd->obd_name,
1031                         handle);
1032                 RETURN(-EPROTO);
1033         }
1034
1035         rc = llog_handle2ops(handle, &lop);
1036         if (rc)
1037                 RETURN(rc);
1038
1039         if (lop->lop_write_rec == NULL)
1040                 RETURN(-EOPNOTSUPP);
1041
1042         buflen = rec->lrh_len;
1043         LASSERT(cfs_size_round(buflen) == buflen);
1044
1045         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
1046         if (!raised)
1047                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
1048         rc = lop->lop_write_rec(env, handle, rec, logcookies, idx, th);
1049         if (!raised)
1050                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
1051         RETURN(rc);
1052 }
1053
1054 int llog_add(const struct lu_env *env, struct llog_handle *lgh,
1055              struct llog_rec_hdr *rec, struct llog_cookie *logcookies,
1056              struct thandle *th)
1057 {
1058         int raised, rc;
1059
1060         ENTRY;
1061
1062         if (lgh->lgh_logops->lop_add == NULL)
1063                 RETURN(-EOPNOTSUPP);
1064
1065         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
1066         if (!raised)
1067                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
1068         rc = lgh->lgh_logops->lop_add(env, lgh, rec, logcookies, th);
1069         if (!raised)
1070                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
1071         RETURN(rc);
1072 }
1073 EXPORT_SYMBOL(llog_add);
1074
1075 int llog_declare_add(const struct lu_env *env, struct llog_handle *lgh,
1076                      struct llog_rec_hdr *rec, struct thandle *th)
1077 {
1078         int raised, rc;
1079
1080         ENTRY;
1081
1082         if (lgh->lgh_logops->lop_declare_add == NULL)
1083                 RETURN(-EOPNOTSUPP);
1084
1085         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
1086         if (!raised)
1087                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
1088         rc = lgh->lgh_logops->lop_declare_add(env, lgh, rec, th);
1089         if (!raised)
1090                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
1091         RETURN(rc);
1092 }
1093 EXPORT_SYMBOL(llog_declare_add);
1094
1095 /**
1096  * Helper function to open llog or create it if doesn't exist.
1097  * It hides all transaction handling from caller.
1098  */
1099 int llog_open_create(const struct lu_env *env, struct llog_ctxt *ctxt,
1100                      struct llog_handle **res, struct llog_logid *logid,
1101                      char *name)
1102 {
1103         struct dt_device        *d;
1104         struct thandle          *th;
1105         int                      rc;
1106
1107         ENTRY;
1108
1109         rc = llog_open(env, ctxt, res, logid, name, LLOG_OPEN_NEW);
1110         if (rc)
1111                 RETURN(rc);
1112
1113         if (llog_exist(*res))
1114                 RETURN(0);
1115
1116         LASSERT((*res)->lgh_obj != NULL);
1117
1118         d = lu2dt_dev((*res)->lgh_obj->do_lu.lo_dev);
1119
1120         th = dt_trans_create(env, d);
1121         if (IS_ERR(th))
1122                 GOTO(out, rc = PTR_ERR(th));
1123
1124         /* Create update llog object synchronously, which
1125          * happens during inialization process see
1126          * lod_sub_prep_llog(), to make sure the update
1127          * llog object is created before corss-MDT writing
1128          * updates into the llog object */
1129         if (ctxt->loc_flags & LLOG_CTXT_FLAG_NORMAL_FID)
1130                 th->th_sync = 1;
1131
1132         th->th_wait_submit = 1;
1133         rc = llog_declare_create(env, *res, th);
1134         if (rc == 0) {
1135                 rc = dt_trans_start_local(env, d, th);
1136                 if (rc == 0)
1137                         rc = llog_create(env, *res, th);
1138         }
1139         dt_trans_stop(env, d, th);
1140 out:
1141         if (rc)
1142                 llog_close(env, *res);
1143         RETURN(rc);
1144 }
1145 EXPORT_SYMBOL(llog_open_create);
1146
1147 /**
1148  * Helper function to delete existent llog.
1149  */
1150 int llog_erase(const struct lu_env *env, struct llog_ctxt *ctxt,
1151                struct llog_logid *logid, char *name)
1152 {
1153         struct llog_handle      *handle;
1154         int                      rc = 0, rc2;
1155
1156         ENTRY;
1157
1158         /* nothing to erase */
1159         if (name == NULL && logid == NULL)
1160                 RETURN(0);
1161
1162         rc = llog_open(env, ctxt, &handle, logid, name, LLOG_OPEN_EXISTS);
1163         if (rc < 0)
1164                 RETURN(rc);
1165
1166         rc = llog_init_handle(env, handle, LLOG_F_IS_PLAIN, NULL);
1167         if (rc == 0)
1168                 rc = llog_destroy(env, handle);
1169
1170         rc2 = llog_close(env, handle);
1171         if (rc == 0)
1172                 rc = rc2;
1173         RETURN(rc);
1174 }
1175 EXPORT_SYMBOL(llog_erase);
1176
1177 /*
1178  * Helper function for write record in llog.
1179  * It hides all transaction handling from caller.
1180  * Valid only with local llog.
1181  */
1182 int llog_write(const struct lu_env *env, struct llog_handle *loghandle,
1183                struct llog_rec_hdr *rec, int idx)
1184 {
1185         struct dt_device        *dt;
1186         struct thandle          *th;
1187         bool                    need_cookie;
1188         int                     rc;
1189
1190         ENTRY;
1191
1192         LASSERT(loghandle);
1193         LASSERT(loghandle->lgh_ctxt);
1194         LASSERT(loghandle->lgh_obj != NULL);
1195
1196         dt = lu2dt_dev(loghandle->lgh_obj->do_lu.lo_dev);
1197
1198         th = dt_trans_create(env, dt);
1199         if (IS_ERR(th))
1200                 RETURN(PTR_ERR(th));
1201
1202         rc = llog_declare_write_rec(env, loghandle, rec, idx, th);
1203         if (rc)
1204                 GOTO(out_trans, rc);
1205
1206         th->th_wait_submit = 1;
1207         rc = dt_trans_start_local(env, dt, th);
1208         if (rc)
1209                 GOTO(out_trans, rc);
1210
1211         need_cookie = !(idx == LLOG_HEADER_IDX || idx == LLOG_NEXT_IDX);
1212
1213         down_write(&loghandle->lgh_lock);
1214         if (need_cookie) {
1215                 struct llog_thread_info *lti = llog_info(env);
1216
1217                 /* cookie comes from llog_process_thread */
1218                 rc = llog_write_rec(env, loghandle, rec, &lti->lgi_cookie,
1219                                     rec->lrh_index, th);
1220                 /* upper layer didn`t pass cookie so change rc */
1221                 rc = (rc == 1 ? 0 : rc);
1222         } else {
1223                 rc = llog_write_rec(env, loghandle, rec, NULL, idx, th);
1224         }
1225
1226         up_write(&loghandle->lgh_lock);
1227 out_trans:
1228         dt_trans_stop(env, dt, th);
1229         RETURN(rc);
1230 }
1231 EXPORT_SYMBOL(llog_write);
1232
1233 int llog_open(const struct lu_env *env, struct llog_ctxt *ctxt,
1234               struct llog_handle **lgh, struct llog_logid *logid,
1235               char *name, enum llog_open_param open_param)
1236 {
1237         int      raised;
1238         int      rc;
1239
1240         ENTRY;
1241
1242         LASSERT(ctxt);
1243         LASSERT(ctxt->loc_logops);
1244
1245         if (ctxt->loc_logops->lop_open == NULL) {
1246                 *lgh = NULL;
1247                 RETURN(-EOPNOTSUPP);
1248         }
1249
1250         *lgh = llog_alloc_handle();
1251         if (*lgh == NULL)
1252                 RETURN(-ENOMEM);
1253         (*lgh)->lgh_ctxt = ctxt;
1254         (*lgh)->lgh_logops = ctxt->loc_logops;
1255
1256         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
1257         if (!raised)
1258                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
1259         rc = ctxt->loc_logops->lop_open(env, *lgh, logid, name, open_param);
1260         if (!raised)
1261                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
1262         if (rc) {
1263                 llog_free_handle(*lgh);
1264                 *lgh = NULL;
1265         }
1266         RETURN(rc);
1267 }
1268 EXPORT_SYMBOL(llog_open);
1269
1270 int llog_close(const struct lu_env *env, struct llog_handle *loghandle)
1271 {
1272         struct llog_operations  *lop;
1273         int                      rc;
1274
1275         ENTRY;
1276
1277         rc = llog_handle2ops(loghandle, &lop);
1278         if (rc)
1279                 GOTO(out, rc);
1280         if (lop->lop_close == NULL)
1281                 GOTO(out, rc = -EOPNOTSUPP);
1282         rc = lop->lop_close(env, loghandle);
1283 out:
1284         llog_handle_put(loghandle);
1285         RETURN(rc);
1286 }
1287 EXPORT_SYMBOL(llog_close);
1288
1289 /**
1290  * Helper function to get the llog size in records. It is used by MGS
1291  * mostly to check that config llog exists and contains data.
1292  *
1293  * \param[in] env       execution environment
1294  * \param[in] ctxt      llog context
1295  * \param[in] name      llog name
1296  *
1297  * \retval              true if there are records in llog besides a header
1298  * \retval              false on error or llog without records
1299  */
1300 int llog_is_empty(const struct lu_env *env, struct llog_ctxt *ctxt,
1301                   char *name)
1302 {
1303         struct llog_handle      *llh;
1304         int                      rc = 0;
1305
1306         rc = llog_open(env, ctxt, &llh, NULL, name, LLOG_OPEN_EXISTS);
1307         if (rc < 0) {
1308                 if (likely(rc == -ENOENT))
1309                         rc = 0;
1310                 GOTO(out, rc);
1311         }
1312
1313         rc = llog_init_handle(env, llh, LLOG_F_IS_PLAIN, NULL);
1314         if (rc)
1315                 GOTO(out_close, rc);
1316         rc = llog_get_size(llh);
1317
1318 out_close:
1319         llog_close(env, llh);
1320 out:
1321         /* The header is record 1, the llog is still considered as empty
1322          * if there is only header */
1323         return (rc <= 1);
1324 }
1325 EXPORT_SYMBOL(llog_is_empty);
1326
1327 int llog_copy_handler(const struct lu_env *env, struct llog_handle *llh,
1328                       struct llog_rec_hdr *rec, void *data)
1329 {
1330         struct llog_handle      *copy_llh = data;
1331
1332         /* Append all records */
1333         return llog_write(env, copy_llh, rec, LLOG_NEXT_IDX);
1334 }
1335
1336 /* backup plain llog */
1337 int llog_backup(const struct lu_env *env, struct obd_device *obd,
1338                 struct llog_ctxt *ctxt, struct llog_ctxt *bctxt,
1339                 char *name, char *backup)
1340 {
1341         struct llog_handle      *llh, *bllh;
1342         int                      rc;
1343
1344         ENTRY;
1345
1346         /* open original log */
1347         rc = llog_open(env, ctxt, &llh, NULL, name, LLOG_OPEN_EXISTS);
1348         if (rc < 0) {
1349                 /* the -ENOENT case is also reported to the caller
1350                  * but silently so it should handle that if needed.
1351                  */
1352                 if (rc != -ENOENT)
1353                         CERROR("%s: failed to open log %s: rc = %d\n",
1354                                obd->obd_name, name, rc);
1355                 RETURN(rc);
1356         }
1357
1358         rc = llog_init_handle(env, llh, LLOG_F_IS_PLAIN, NULL);
1359         if (rc)
1360                 GOTO(out_close, rc);
1361
1362         /* Make sure there's no old backup log */
1363         rc = llog_erase(env, bctxt, NULL, backup);
1364         if (rc < 0 && rc != -ENOENT)
1365                 GOTO(out_close, rc);
1366
1367         /* open backup log */
1368         rc = llog_open_create(env, bctxt, &bllh, NULL, backup);
1369         if (rc) {
1370                 CERROR("%s: failed to open backup logfile %s: rc = %d\n",
1371                        obd->obd_name, backup, rc);
1372                 GOTO(out_close, rc);
1373         }
1374
1375         /* check that backup llog is not the same object as original one */
1376         if (llh->lgh_obj == bllh->lgh_obj) {
1377                 CERROR("%s: backup llog %s to itself (%s), objects %p/%p\n",
1378                        obd->obd_name, name, backup, llh->lgh_obj,
1379                        bllh->lgh_obj);
1380                 GOTO(out_backup, rc = -EEXIST);
1381         }
1382
1383         rc = llog_init_handle(env, bllh, LLOG_F_IS_PLAIN, NULL);
1384         if (rc)
1385                 GOTO(out_backup, rc);
1386
1387         /* Copy log record by record */
1388         rc = llog_process_or_fork(env, llh, llog_copy_handler, (void *)bllh,
1389                                   NULL, false);
1390         if (rc)
1391                 CERROR("%s: failed to backup log %s: rc = %d\n",
1392                        obd->obd_name, name, rc);
1393 out_backup:
1394         llog_close(env, bllh);
1395 out_close:
1396         llog_close(env, llh);
1397         RETURN(rc);
1398 }
1399 EXPORT_SYMBOL(llog_backup);
1400
1401 /* Get size of llog */
1402 __u64 llog_size(const struct lu_env *env, struct llog_handle *llh)
1403 {
1404         int rc;
1405         struct lu_attr la;
1406
1407         rc = llh->lgh_obj->do_ops->do_attr_get(env, llh->lgh_obj, &la);
1408         if (rc) {
1409                 CERROR("%s: attr_get failed for "DFID": rc = %d\n",
1410                        llh->lgh_ctxt->loc_obd->obd_name,
1411                        PFID(&llh->lgh_id.lgl_oi.oi_fid), rc);
1412                 return 0;
1413         }
1414
1415         return la.la_size;
1416 }
1417 EXPORT_SYMBOL(llog_size);
1418