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 "DFID"\n", index,
 208                PFID(&loghandle->lgh_id.lgl_oi.oi_fid));
 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 "DFID": rc = %d\n",
 274                                loghandle->lgh_ctxt->loc_obd->obd_name,
 275                                PFID(&loghandle->lgh_id.lgl_oi.oi_fid), rc);
 276                         GOTO(out_unlock, rc = 0);
 277                 }
 278                 rc = LLOG_DEL_PLAIN;
 279         }
 280
 281 out_unlock:
 282         mutex_unlock(&loghandle->lgh_hdr_mutex);
 283         up_write(&loghandle->lgh_lock);
 284 out_trans:
 285         rc1 = dt_trans_stop(env, dt, th);
 286         if (rc == 0)
 287                 rc = rc1;
 288         if (rc < 0 && subtract_count) {
 289                 mutex_lock(&loghandle->lgh_hdr_mutex);
 290                 loghandle->lgh_hdr->llh_count++;
 291                 ext2_set_bit(index, LLOG_HDR_BITMAP(llh));
 292                 mutex_unlock(&loghandle->lgh_hdr_mutex);
 293         }
 294         RETURN(rc);
 295 }
 296
 297 int llog_read_header(const struct lu_env *env, struct llog_handle *handle,
 298                      const struct obd_uuid *uuid)
 299 {
 300         struct llog_operations *lop;
 301         int rc;
 302         ENTRY;
 303
 304         rc = llog_handle2ops(handle, &lop);
 305         if (rc)
 306                 RETURN(rc);
 307
 308         if (lop->lop_read_header == NULL)
 309                 RETURN(-EOPNOTSUPP);
 310
 311         rc = lop->lop_read_header(env, handle);
 312         if (rc == LLOG_EEMPTY) {
 313                 struct llog_log_hdr *llh = handle->lgh_hdr;
 314
 315                 /* lrh_len should be initialized in llog_init_handle */
 316                 handle->lgh_last_idx = 0; /* header is record with index 0 */
 317                 llh->llh_count = 1;         /* for the header record */
 318                 llh->llh_hdr.lrh_type = LLOG_HDR_MAGIC;
 319                 LASSERT(handle->lgh_ctxt->loc_chunk_size >=
 320                                                 LLOG_MIN_CHUNK_SIZE);
 321                 llh->llh_hdr.lrh_len = handle->lgh_ctxt->loc_chunk_size;
 322                 llh->llh_hdr.lrh_index = 0;
 323                 llh->llh_timestamp = ktime_get_real_seconds();
 324                 if (uuid)
 325                         memcpy(&llh->llh_tgtuuid, uuid,
 326                                sizeof(llh->llh_tgtuuid));
 327                 llh->llh_bitmap_offset = offsetof(typeof(*llh), llh_bitmap);
 328                 /* Since update llog header might also call this function,
 329                  * let's reset the bitmap to 0 here */
 330                 memset(LLOG_HDR_BITMAP(llh), 0, llh->llh_hdr.lrh_len -
 331                                                 llh->llh_bitmap_offset -
 332                                                 sizeof(llh->llh_tail));
 333                 ext2_set_bit(0, LLOG_HDR_BITMAP(llh));
 334                 LLOG_HDR_TAIL(llh)->lrt_len = llh->llh_hdr.lrh_len;
 335                 LLOG_HDR_TAIL(llh)->lrt_index = llh->llh_hdr.lrh_index;
 336                 rc = 0;
 337         }
 338         RETURN(rc);
 339 }
 340 EXPORT_SYMBOL(llog_read_header);
 341
 342 int llog_init_handle(const struct lu_env *env, struct llog_handle *handle,
 343                      int flags, struct obd_uuid *uuid)
 344 {
 345         struct llog_log_hdr     *llh;
 346         enum llog_flag           fmt = flags & LLOG_F_EXT_MASK;
 347         int                      rc;
 348         int                     chunk_size = handle->lgh_ctxt->loc_chunk_size;
 349         ENTRY;
 350
 351         LASSERT(handle->lgh_hdr == NULL);
 352
 353         LASSERT(chunk_size >= LLOG_MIN_CHUNK_SIZE);
 354         OBD_ALLOC_LARGE(llh, chunk_size);
 355         if (llh == NULL)
 356                 RETURN(-ENOMEM);
 357
 358         handle->lgh_hdr = llh;
 359         handle->lgh_hdr_size = chunk_size;
 360         /* first assign flags to use llog_client_ops */
 361         llh->llh_flags = flags;
 362         rc = llog_read_header(env, handle, uuid);
 363         if (rc == 0) {
 364                 if (unlikely((llh->llh_flags & LLOG_F_IS_PLAIN &&
 365                               flags & LLOG_F_IS_CAT) ||
 366                              (llh->llh_flags & LLOG_F_IS_CAT &&
 367                               flags & LLOG_F_IS_PLAIN))) {
 368                         CERROR("%s: llog type is %s but initializing %s\n",
 369                                handle->lgh_ctxt->loc_obd->obd_name,
 370                                llh->llh_flags & LLOG_F_IS_CAT ?
 371                                "catalog" : "plain",
 372                                flags & LLOG_F_IS_CAT ? "catalog" : "plain");
 373                         GOTO(out, rc = -EINVAL);
 374                 } else if (llh->llh_flags &
 375                            (LLOG_F_IS_PLAIN | LLOG_F_IS_CAT)) {
 376                         /*
 377                          * it is possible to open llog without specifying llog
 378                          * type so it is taken from llh_flags
 379                          */
 380                         flags = llh->llh_flags;
 381                 } else {
 382                         /* for some reason the llh_flags has no type set */
 383                         CERROR("llog type is not specified!\n");
 384                         GOTO(out, rc = -EINVAL);
 385                 }
 386                 if (unlikely(uuid &&
 387                              !obd_uuid_equals(uuid, &llh->llh_tgtuuid))) {
 388                         CERROR("%s: llog uuid mismatch: %s/%s\n",
 389                                handle->lgh_ctxt->loc_obd->obd_name,
 390                                (char *)uuid->uuid,
 391                                (char *)llh->llh_tgtuuid.uuid);
 392                         GOTO(out, rc = -EEXIST);
 393                 }
 394         }
 395         if (flags & LLOG_F_IS_CAT) {
 396                 LASSERT(list_empty(&handle->u.chd.chd_head));
 397                 INIT_LIST_HEAD(&handle->u.chd.chd_head);
 398                 llh->llh_size = sizeof(struct llog_logid_rec);
 399                 llh->llh_flags |= LLOG_F_IS_FIXSIZE;
 400         } else if (!(flags & LLOG_F_IS_PLAIN)) {
 401                 CERROR("%s: unknown flags: %#x (expected %#x or %#x)\n",
 402                        handle->lgh_ctxt->loc_obd->obd_name,
 403                        flags, LLOG_F_IS_CAT, LLOG_F_IS_PLAIN);
 404                 rc = -EINVAL;
 405         }
 406         llh->llh_flags |= fmt;
 407 out:
 408         if (rc) {
 409                 OBD_FREE_LARGE(llh, chunk_size);
 410                 handle->lgh_hdr = NULL;
 411         }
 412         RETURN(rc);
 413 }
 414 EXPORT_SYMBOL(llog_init_handle);
 415
 416 static int llog_process_thread(void *arg)
 417 {
 418         struct llog_process_info        *lpi = arg;
 419         struct llog_handle              *loghandle = lpi->lpi_loghandle;
 420         struct llog_log_hdr             *llh = loghandle->lgh_hdr;
 421         struct llog_process_cat_data    *cd  = lpi->lpi_catdata;
 422         struct llog_thread_info         *lti;
 423         char                            *buf;
 424         size_t                           chunk_size;
 425         __u64                            cur_offset;
 426         int                              rc = 0, index = 1, last_index;
 427         int                              saved_index = 0;
 428         int                              last_called_index = 0;
 429         bool                             repeated = false;
 430
 431         ENTRY;
 432
 433         if (llh == NULL)
 434                 RETURN(-EINVAL);
 435
 436         lti = lpi->lpi_env == NULL ? NULL : llog_info(lpi->lpi_env);
 437
 438         cur_offset = chunk_size = llh->llh_hdr.lrh_len;
 439         /* expect chunk_size to be power of two */
 440         LASSERT(is_power_of_2(chunk_size));
 441
 442         OBD_ALLOC_LARGE(buf, chunk_size);
 443         if (buf == NULL) {
 444                 lpi->lpi_rc = -ENOMEM;
 445                 RETURN(0);
 446         }
 447
 448         if (cd != NULL) {
 449                 last_called_index = cd->lpcd_first_idx;
 450                 index = cd->lpcd_first_idx + 1;
 451         }
 452         if (cd != NULL && cd->lpcd_last_idx)
 453                 last_index = cd->lpcd_last_idx;
 454         else
 455                 last_index = LLOG_HDR_BITMAP_SIZE(llh) - 1;
 456
 457         while (rc == 0) {
 458                 struct llog_rec_hdr *rec;
 459                 off_t chunk_offset = 0;
 460                 unsigned int buf_offset = 0;
 461                 bool partial_chunk;
 462                 int     lh_last_idx;
 463
 464                 /* skip records not set in bitmap */
 465                 while (index <= last_index &&
 466                        !ext2_test_bit(index, LLOG_HDR_BITMAP(llh)))
 467                         ++index;
 468
 469                 /* There are no indices prior the last_index */
 470                 if (index > last_index)
 471                         break;
 472
 473                 CDEBUG(D_OTHER, "index: %d last_index %d\n", index,
 474                        last_index);
 475
 476 repeat:
 477                 /* get the buf with our target record; avoid old garbage */
 478                 memset(buf, 0, chunk_size);
 479                 /* the record index for outdated chunk data */
 480                 lh_last_idx = loghandle->lgh_last_idx + 1;
 481                 rc = llog_next_block(lpi->lpi_env, loghandle, &saved_index,
 482                                      index, &cur_offset, buf, chunk_size);
 483                 if (repeated && rc)
 484                         CDEBUG(D_OTHER, "cur_offset %llu, chunk_offset %llu,"
 485                                " buf_offset %u, rc = %d\n", cur_offset,
 486                                (__u64)chunk_offset, buf_offset, rc);
 487                 /* we`ve tried to reread the chunk, but there is no
 488                  * new records */
 489                 if (rc == -EIO && repeated && (chunk_offset + buf_offset) ==
 490                     cur_offset)
 491                         GOTO(out, rc = 0);
 492                 if (rc != 0)
 493                         GOTO(out, rc);
 494
 495                 /* NB: after llog_next_block() call the cur_offset is the
 496                  * offset of the next block after read one.
 497                  * The absolute offset of the current chunk is calculated
 498                  * from cur_offset value and stored in chunk_offset variable.
 499                  */
 500                 if ((cur_offset & (chunk_size - 1)) != 0) {
 501                         partial_chunk = true;
 502                         chunk_offset = cur_offset & ~(chunk_size - 1);
 503                 } else {
 504                         partial_chunk = false;
 505                         chunk_offset = cur_offset - chunk_size;
 506                 }
 507
 508                 /* NB: when rec->lrh_len is accessed it is already swabbed
 509                  * since it is used at the "end" of the loop and the rec
 510                  * swabbing is done at the beginning of the loop. */
 511                 for (rec = (struct llog_rec_hdr *)(buf + buf_offset);
 512                      (char *)rec < buf + chunk_size;
 513                      rec = llog_rec_hdr_next(rec)) {
 514
 515                         CDEBUG(D_OTHER, "processing rec 0x%p type %#x\n",
 516                                rec, rec->lrh_type);
 517
 518                         if (LLOG_REC_HDR_NEEDS_SWABBING(rec))
 519                                 lustre_swab_llog_rec(rec);
 520
 521                         CDEBUG(D_OTHER, "after swabbing, type=%#x idx=%d\n",
 522                                rec->lrh_type, rec->lrh_index);
 523
 524                         /* the bitmap could be changed during processing
 525                          * records from the chunk. For wrapped catalog
 526                          * it means we can read deleted record and try to
 527                          * process it. Check this case and reread the chunk. */
 528
 529                         /* for partial chunk the end of it is zeroed, check
 530                          * for index 0 to distinguish it. */
 531                         if ((partial_chunk && rec->lrh_index == 0) ||
 532                              (index == lh_last_idx &&
 533                               lh_last_idx != (loghandle->lgh_last_idx + 1))) {
 534                                 /* concurrent llog_add() might add new records
 535                                  * while llog_processing, check this is not
 536                                  * the case and re-read the current chunk
 537                                  * otherwise. */
 538                                 int records;
 539                                 /* lgh_last_idx could be less then index
 540                                  * for catalog, if catalog is wrapped */
 541                                 if ((index > loghandle->lgh_last_idx &&
 542                                     !(loghandle->lgh_hdr->llh_flags &
 543                                       LLOG_F_IS_CAT)) || repeated ||
 544                                     (loghandle->lgh_obj != NULL &&
 545                                      dt_object_remote(loghandle->lgh_obj)))
 546                                         GOTO(out, rc = 0);
 547                                 /* <2 records means no more records
 548                                  * if the last record we processed was
 549                                  * the final one, then the underlying
 550                                  * object might have been destroyed yet.
 551                                  * we better don't access that.. */
 552                                 mutex_lock(&loghandle->lgh_hdr_mutex);
 553                                 records = loghandle->lgh_hdr->llh_count;
 554                                 mutex_unlock(&loghandle->lgh_hdr_mutex);
 555                                 if (records <= 1)
 556                                         GOTO(out, rc = 0);
 557                                 CDEBUG(D_OTHER, "Re-read last llog buffer for "
 558                                        "new records, index %u, last %u\n",
 559                                        index, loghandle->lgh_last_idx);
 560                                 /* save offset inside buffer for the re-read */
 561                                 buf_offset = (char *)rec - (char *)buf;
 562                                 cur_offset = chunk_offset;
 563                                 repeated = true;
 564                                 goto repeat;
 565                         }
 566
 567                         repeated = false;
 568
 569                         if (rec->lrh_len == 0 || rec->lrh_len > chunk_size) {
 570                                 CWARN("%s: invalid length %d in llog "DFID
 571                                       "record for index %d/%d\n",
 572                                        loghandle->lgh_ctxt->loc_obd->obd_name,
 573                                        rec->lrh_len,
 574                                        PFID(&loghandle->lgh_id.lgl_oi.oi_fid),
 575                                        rec->lrh_index, index);
 576
 577                                 GOTO(out, rc = -EINVAL);
 578                         }
 579
 580                         if (rec->lrh_index < index) {
 581                                 CDEBUG(D_OTHER, "skipping lrh_index %d\n",
 582                                        rec->lrh_index);
 583                                 continue;
 584                         }
 585
 586                         if (rec->lrh_index != index) {
 587                                 CERROR("%s: "DFID" Invalid record: index %u"
 588                                        " but expected %u\n",
 589                                        loghandle->lgh_ctxt->loc_obd->obd_name,
 590                                        PFID(&loghandle->lgh_id.lgl_oi.oi_fid),
 591                                        rec->lrh_index, index);
 592                                 GOTO(out, rc = -ERANGE);
 593                         }
 594
 595                         CDEBUG(D_OTHER,
 596                                "lrh_index: %d lrh_len: %d (%d remains)\n",
 597                                rec->lrh_index, rec->lrh_len,
 598                                (int)(buf + chunk_size - (char *)rec));
 599
 600                         /* lgh_cur_offset is used only at llog_test_3 */
 601                         loghandle->lgh_cur_offset = (char *)rec - (char *)buf +
 602                                                     chunk_offset;
 603
 604                         /* if set, process the callback on this record */
 605                         if (ext2_test_bit(index, LLOG_HDR_BITMAP(llh))) {
 606                                 struct llog_cookie *lgc;
 607                                 __u64   tmp_off;
 608                                 int     tmp_idx;
 609
 610                                 if (lti != NULL) {
 611                                         lgc = &lti->lgi_cookie;
 612                                         /* store lu_env for recursive calls */
 613                                         tmp_off = lgc->lgc_offset;
 614                                         tmp_idx = lgc->lgc_index;
 615
 616                                         lgc->lgc_offset = (char *)rec -
 617                                                 (char *)buf + chunk_offset;
 618                                         lgc->lgc_index = rec->lrh_index;
 619                                 }
 620                                 /* using lu_env for passing record offset to
 621                                  * llog_write through various callbacks */
 622                                 rc = lpi->lpi_cb(lpi->lpi_env, loghandle, rec,
 623                                                  lpi->lpi_cbdata);
 624                                 last_called_index = index;
 625
 626                                 if (lti != NULL) {
 627                                         lgc->lgc_offset = tmp_off;
 628                                         lgc->lgc_index = tmp_idx;
 629                                 }
 630
 631                                 if (rc == LLOG_PROC_BREAK) {
 632                                         GOTO(out, rc);
 633                                 } else if (rc == LLOG_DEL_RECORD) {
 634                                         rc = llog_cancel_rec(lpi->lpi_env,
 635                                                              loghandle,
 636                                                              rec->lrh_index);
 637                                 }
 638                                 if (rc)
 639                                         GOTO(out, rc);
 640                                 /* some stupid callbacks directly cancel records
 641                                  * and delete llog. Check it and stop
 642                                  * processing. */
 643                                 if (loghandle->lgh_hdr == NULL ||
 644                                     loghandle->lgh_hdr->llh_count == 1)
 645                                         GOTO(out, rc = 0);
 646                         }
 647                         /* exit if the last index is reached */
 648                         if (index >= last_index)
 649                                 GOTO(out, rc = 0);
 650                         ++index;
 651                 }
 652         }
 653
 654 out:
 655         if (cd != NULL)
 656                 cd->lpcd_last_idx = last_called_index;
 657
 658         if (unlikely(rc == -EIO && loghandle->lgh_obj != NULL)) {
 659                 if (dt_object_remote(loghandle->lgh_obj)) {
 660                         /* If it is remote object, then -EIO might means
 661                          * disconnection or eviction, let's return -EAGAIN,
 662                          * so for update recovery log processing, it will
 663                          * retry until the umount or abort recovery, see
 664                          * lod_sub_recovery_thread() */
 665                         CERROR("%s retry remote llog process\n",
 666                                loghandle->lgh_ctxt->loc_obd->obd_name);
 667                         rc = -EAGAIN;
 668                 } else {
 669                         /* something bad happened to the processing of a local
 670                          * llog file, probably I/O error or the log got
 671                          * corrupted to be able to finally release the log we
 672                          * discard any remaining bits in the header */
 673                         CERROR("%s: Local llog found corrupted #"DOSTID":%x"
 674                                " %s index %d count %d\n",
 675                                loghandle->lgh_ctxt->loc_obd->obd_name,
 676                                POSTID(&loghandle->lgh_id.lgl_oi),
 677                                loghandle->lgh_id.lgl_ogen,
 678                                ((llh->llh_flags & LLOG_F_IS_CAT) ? "catalog" :
 679                                 "plain"), index, llh->llh_count);
 680
 681                         while (index <= last_index) {
 682                                 if (ext2_test_bit(index,
 683                                                   LLOG_HDR_BITMAP(llh)) != 0)
 684                                         llog_cancel_rec(lpi->lpi_env, loghandle,
 685                                                         index);
 686                                 index++;
 687                         }
 688                         rc = 0;
 689                 }
 690         }
 691
 692         OBD_FREE_LARGE(buf, chunk_size);
 693         lpi->lpi_rc = rc;
 694         return 0;
 695 }
 696
 697 static int llog_process_thread_daemonize(void *arg)
 698 {
 699         struct llog_process_info        *lpi = arg;
 700         struct lu_env                    env;
 701         int                              rc;
 702         struct nsproxy                  *new_ns, *curr_ns = current->nsproxy;
 703
 704         task_lock(lpi->lpi_reftask);
 705         new_ns = lpi->lpi_reftask->nsproxy;
 706         if (curr_ns != new_ns) {
 707                 get_nsproxy(new_ns);
 708
 709                 current->nsproxy = new_ns;
 710                 /* XXX: we should call put_nsproxy() instead of
 711                  * atomic_dec(&ns->count) directly. But put_nsproxy() cannot be
 712                  * used outside of the kernel itself, because it calls
 713                  * free_nsproxy() which is not exported by the kernel
 714                  * (defined in kernel/nsproxy.c) */
 715                 atomic_dec(&curr_ns->count);
 716         }
 717         task_unlock(lpi->lpi_reftask);
 718
 719         unshare_fs_struct();
 720
 721         /* client env has no keys, tags is just 0 */
 722         rc = lu_env_init(&env, LCT_LOCAL | LCT_MG_THREAD);
 723         if (rc)
 724                 goto out;
 725         lpi->lpi_env = &env;
 726
 727         rc = llog_process_thread(arg);
 728
 729         lu_env_fini(&env);
 730 out:
 731         complete(&lpi->lpi_completion);
 732         return rc;
 733 }
 734
 735 int llog_process_or_fork(const struct lu_env *env,
 736                          struct llog_handle *loghandle,
 737                          llog_cb_t cb, void *data, void *catdata, bool fork)
 738 {
 739         struct llog_process_info *lpi;
 740         int                      rc;
 741
 742         ENTRY;
 743
 744         OBD_ALLOC_PTR(lpi);
 745         if (lpi == NULL) {
 746                 CERROR("cannot alloc pointer\n");
 747                 RETURN(-ENOMEM);
 748         }
 749         lpi->lpi_loghandle = loghandle;
 750         lpi->lpi_cb        = cb;
 751         lpi->lpi_cbdata    = data;
 752         lpi->lpi_catdata   = catdata;
 753
 754         if (fork) {
 755                 struct task_struct *task;
 756
 757                 /* The new thread can't use parent env,
 758                  * init the new one in llog_process_thread_daemonize. */
 759                 lpi->lpi_env = NULL;
 760                 init_completion(&lpi->lpi_completion);
 761                 /* take reference to current, so that
 762                  * llog_process_thread_daemonize() can use it to switch to
 763                  * namespace associated with current  */
 764                 lpi->lpi_reftask = current;
 765                 task = kthread_run(llog_process_thread_daemonize, lpi,
 766                                    "llog_process_thread");
 767                 if (IS_ERR(task)) {
 768                         rc = PTR_ERR(task);
 769                         CERROR("%s: cannot start thread: rc = %d\n",
 770                                loghandle->lgh_ctxt->loc_obd->obd_name, rc);
 771                         GOTO(out_lpi, rc);
 772                 }
 773                 wait_for_completion(&lpi->lpi_completion);
 774         } else {
 775                 lpi->lpi_env = env;
 776                 llog_process_thread(lpi);
 777         }
 778         rc = lpi->lpi_rc;
 779
 780 out_lpi:
 781         OBD_FREE_PTR(lpi);
 782         RETURN(rc);
 783 }
 784 EXPORT_SYMBOL(llog_process_or_fork);
 785
 786 int llog_process(const struct lu_env *env, struct llog_handle *loghandle,
 787                  llog_cb_t cb, void *data, void *catdata)
 788 {
 789         int rc;
 790         rc = llog_process_or_fork(env, loghandle, cb, data, catdata, true);
 791         return rc == LLOG_DEL_PLAIN ? 0 : rc;
 792 }
 793 EXPORT_SYMBOL(llog_process);
 794
 795 int llog_reverse_process(const struct lu_env *env,
 796                          struct llog_handle *loghandle, llog_cb_t cb,
 797                          void *data, void *catdata)
 798 {
 799         struct llog_log_hdr *llh = loghandle->lgh_hdr;
 800         struct llog_process_cat_data *cd = catdata;
 801         void *buf;
 802         int rc = 0, first_index = 1, index, idx;
 803         __u32   chunk_size = llh->llh_hdr.lrh_len;
 804         ENTRY;
 805
 806         OBD_ALLOC_LARGE(buf, chunk_size);
 807         if (buf == NULL)
 808                 RETURN(-ENOMEM);
 809
 810         if (cd != NULL)
 811                 first_index = cd->lpcd_first_idx + 1;
 812         if (cd != NULL && cd->lpcd_last_idx)
 813                 index = cd->lpcd_last_idx;
 814         else
 815                 index = LLOG_HDR_BITMAP_SIZE(llh) - 1;
 816
 817         while (rc == 0) {
 818                 struct llog_rec_hdr *rec;
 819                 struct llog_rec_tail *tail;
 820
 821                 /* skip records not set in bitmap */
 822                 while (index >= first_index &&
 823                        !ext2_test_bit(index, LLOG_HDR_BITMAP(llh)))
 824                         --index;
 825
 826                 LASSERT(index >= first_index - 1);
 827                 if (index == first_index - 1)
 828                         break;
 829
 830                 /* get the buf with our target record; avoid old garbage */
 831                 memset(buf, 0, chunk_size);
 832                 rc = llog_prev_block(env, loghandle, index, buf, chunk_size);
 833                 if (rc)
 834                         GOTO(out, rc);
 835
 836                 rec = buf;
 837                 idx = rec->lrh_index;
 838                 CDEBUG(D_RPCTRACE, "index %u : idx %u\n", index, idx);
 839                 while (idx < index) {
 840                         rec = (void *)rec + rec->lrh_len;
 841                         if (LLOG_REC_HDR_NEEDS_SWABBING(rec))
 842                                 lustre_swab_llog_rec(rec);
 843                         idx ++;
 844                 }
 845                 LASSERT(idx == index);
 846                 tail = (void *)rec + rec->lrh_len - sizeof(*tail);
 847
 848                 /* process records in buffer, starting where we found one */
 849                 while ((void *)tail > buf) {
 850                         if (tail->lrt_index == 0)
 851                                 GOTO(out, rc = 0); /* no more records */
 852
 853                         /* if set, process the callback on this record */
 854                         if (ext2_test_bit(index, LLOG_HDR_BITMAP(llh))) {
 855                                 rec = (void *)tail - tail->lrt_len +
 856                                       sizeof(*tail);
 857
 858                                 rc = cb(env, loghandle, rec, data);
 859                                 if (rc == LLOG_PROC_BREAK) {
 860                                         GOTO(out, rc);
 861                                 } else if (rc == LLOG_DEL_RECORD) {
 862                                         rc = llog_cancel_rec(env, loghandle,
 863                                                              tail->lrt_index);
 864                                 }
 865                                 if (rc)
 866                                         GOTO(out, rc);
 867                         }
 868
 869                         /* previous record, still in buffer? */
 870                         --index;
 871                         if (index < first_index)
 872                                 GOTO(out, rc = 0);
 873                         tail = (void *)tail - tail->lrt_len;
 874                 }
 875         }
 876
 877 out:
 878         if (buf != NULL)
 879                 OBD_FREE_LARGE(buf, chunk_size);
 880         RETURN(rc);
 881 }
 882 EXPORT_SYMBOL(llog_reverse_process);
 883
 884 /**
 885  * new llog API
 886  *
 887  * API functions:
 888  *      llog_open - open llog, may not exist
 889  *      llog_exist - check if llog exists
 890  *      llog_close - close opened llog, pair for open, frees llog_handle
 891  *      llog_declare_create - declare llog creation
 892  *      llog_create - create new llog on disk, need transaction handle
 893  *      llog_declare_write_rec - declaration of llog write
 894  *      llog_write_rec - write llog record on disk, need transaction handle
 895  *      llog_declare_add - declare llog catalog record addition
 896  *      llog_add - add llog record in catalog, need transaction handle
 897  */
 898 int llog_exist(struct llog_handle *loghandle)
 899 {
 900         struct llog_operations  *lop;
 901         int                      rc;
 902
 903         ENTRY;
 904
 905         rc = llog_handle2ops(loghandle, &lop);
 906         if (rc)
 907                 RETURN(rc);
 908         if (lop->lop_exist == NULL)
 909                 RETURN(-EOPNOTSUPP);
 910
 911         rc = lop->lop_exist(loghandle);
 912         RETURN(rc);
 913 }
 914 EXPORT_SYMBOL(llog_exist);
 915
 916 int llog_declare_create(const struct lu_env *env,
 917                         struct llog_handle *loghandle, struct thandle *th)
 918 {
 919         struct llog_operations  *lop;
 920         int                      raised, rc;
 921
 922         ENTRY;
 923
 924         rc = llog_handle2ops(loghandle, &lop);
 925         if (rc)
 926                 RETURN(rc);
 927         if (lop->lop_declare_create == NULL)
 928                 RETURN(-EOPNOTSUPP);
 929
 930         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 931         if (!raised)
 932                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 933         rc = lop->lop_declare_create(env, loghandle, th);
 934         if (!raised)
 935                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 936         RETURN(rc);
 937 }
 938
 939 int llog_create(const struct lu_env *env, struct llog_handle *handle,
 940                 struct thandle *th)
 941 {
 942         struct llog_operations  *lop;
 943         int                      raised, rc;
 944
 945         ENTRY;
 946
 947         rc = llog_handle2ops(handle, &lop);
 948         if (rc)
 949                 RETURN(rc);
 950         if (lop->lop_create == NULL)
 951                 RETURN(-EOPNOTSUPP);
 952
 953         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 954         if (!raised)
 955                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 956         rc = lop->lop_create(env, handle, th);
 957         if (!raised)
 958                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 959         RETURN(rc);
 960 }
 961
 962 int llog_declare_write_rec(const struct lu_env *env,
 963                            struct llog_handle *handle,
 964                            struct llog_rec_hdr *rec, int idx,
 965                            struct thandle *th)
 966 {
 967         struct llog_operations  *lop;
 968         int                      raised, rc;
 969
 970         ENTRY;
 971
 972         rc = llog_handle2ops(handle, &lop);
 973         if (rc)
 974                 RETURN(rc);
 975         LASSERT(lop);
 976         if (lop->lop_declare_write_rec == NULL)
 977                 RETURN(-EOPNOTSUPP);
 978
 979         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 980         if (!raised)
 981                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 982         rc = lop->lop_declare_write_rec(env, handle, rec, idx, th);
 983         if (!raised)
 984                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 985         RETURN(rc);
 986 }
 987
 988 int llog_write_rec(const struct lu_env *env, struct llog_handle *handle,
 989                    struct llog_rec_hdr *rec, struct llog_cookie *logcookies,
 990                    int idx, struct thandle *th)
 991 {
 992         struct llog_operations  *lop;
 993         int                      raised, rc, buflen;
 994
 995         ENTRY;
 996
 997         /* API sanity checks */
 998         if (handle == NULL) {
 999                 CERROR("loghandle is missed\n");
1000                 RETURN(-EPROTO);
1001         } else if (handle->lgh_obj == NULL) {
1002                 CERROR("loghandle %p with NULL object\n",
1003                         handle);
1004                 RETURN(-EPROTO);
1005         } else if (th == NULL) {
1006                 CERROR("%s: missed transaction handle\n",
1007                         handle->lgh_obj->do_lu.lo_dev->ld_obd->obd_name);
1008                 RETURN(-EPROTO);
1009         } else if (handle->lgh_hdr == NULL) {
1010                 CERROR("%s: loghandle %p with no header\n",
1011                         handle->lgh_obj->do_lu.lo_dev->ld_obd->obd_name,
1012                         handle);
1013                 RETURN(-EPROTO);
1014         }
1015
1016         rc = llog_handle2ops(handle, &lop);
1017         if (rc)
1018                 RETURN(rc);
1019
1020         if (lop->lop_write_rec == NULL)
1021                 RETURN(-EOPNOTSUPP);
1022
1023         buflen = rec->lrh_len;
1024         LASSERT(cfs_size_round(buflen) == buflen);
1025
1026         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
1027         if (!raised)
1028                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
1029         rc = lop->lop_write_rec(env, handle, rec, logcookies, idx, th);
1030         if (!raised)
1031                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
1032         RETURN(rc);
1033 }
1034
1035 int llog_add(const struct lu_env *env, struct llog_handle *lgh,
1036              struct llog_rec_hdr *rec, struct llog_cookie *logcookies,
1037              struct thandle *th)
1038 {
1039         int raised, rc;
1040
1041         ENTRY;
1042
1043         if (lgh->lgh_logops->lop_add == NULL)
1044                 RETURN(-EOPNOTSUPP);
1045
1046         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
1047         if (!raised)
1048                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
1049         rc = lgh->lgh_logops->lop_add(env, lgh, rec, logcookies, th);
1050         if (!raised)
1051                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
1052         RETURN(rc);
1053 }
1054 EXPORT_SYMBOL(llog_add);
1055
1056 int llog_declare_add(const struct lu_env *env, struct llog_handle *lgh,
1057                      struct llog_rec_hdr *rec, struct thandle *th)
1058 {
1059         int raised, rc;
1060
1061         ENTRY;
1062
1063         if (lgh->lgh_logops->lop_declare_add == NULL)
1064                 RETURN(-EOPNOTSUPP);
1065
1066         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
1067         if (!raised)
1068                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
1069         rc = lgh->lgh_logops->lop_declare_add(env, lgh, rec, th);
1070         if (!raised)
1071                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
1072         RETURN(rc);
1073 }
1074 EXPORT_SYMBOL(llog_declare_add);
1075
1076 /**
1077  * Helper function to open llog or create it if doesn't exist.
1078  * It hides all transaction handling from caller.
1079  */
1080 int llog_open_create(const struct lu_env *env, struct llog_ctxt *ctxt,
1081                      struct llog_handle **res, struct llog_logid *logid,
1082                      char *name)
1083 {
1084         struct dt_device        *d;
1085         struct thandle          *th;
1086         int                      rc;
1087
1088         ENTRY;
1089
1090         rc = llog_open(env, ctxt, res, logid, name, LLOG_OPEN_NEW);
1091         if (rc)
1092                 RETURN(rc);
1093
1094         if (llog_exist(*res))
1095                 RETURN(0);
1096
1097         LASSERT((*res)->lgh_obj != NULL);
1098
1099         d = lu2dt_dev((*res)->lgh_obj->do_lu.lo_dev);
1100
1101         th = dt_trans_create(env, d);
1102         if (IS_ERR(th))
1103                 GOTO(out, rc = PTR_ERR(th));
1104
1105         /* Create update llog object synchronously, which
1106          * happens during inialization process see
1107          * lod_sub_prep_llog(), to make sure the update
1108          * llog object is created before corss-MDT writing
1109          * updates into the llog object */
1110         if (ctxt->loc_flags & LLOG_CTXT_FLAG_NORMAL_FID)
1111                 th->th_sync = 1;
1112
1113         th->th_wait_submit = 1;
1114         rc = llog_declare_create(env, *res, th);
1115         if (rc == 0) {
1116                 rc = dt_trans_start_local(env, d, th);
1117                 if (rc == 0)
1118                         rc = llog_create(env, *res, th);
1119         }
1120         dt_trans_stop(env, d, th);
1121 out:
1122         if (rc)
1123                 llog_close(env, *res);
1124         RETURN(rc);
1125 }
1126 EXPORT_SYMBOL(llog_open_create);
1127
1128 /**
1129  * Helper function to delete existent llog.
1130  */
1131 int llog_erase(const struct lu_env *env, struct llog_ctxt *ctxt,
1132                struct llog_logid *logid, char *name)
1133 {
1134         struct llog_handle      *handle;
1135         int                      rc = 0, rc2;
1136
1137         ENTRY;
1138
1139         /* nothing to erase */
1140         if (name == NULL && logid == NULL)
1141                 RETURN(0);
1142
1143         rc = llog_open(env, ctxt, &handle, logid, name, LLOG_OPEN_EXISTS);
1144         if (rc < 0)
1145                 RETURN(rc);
1146
1147         rc = llog_init_handle(env, handle, LLOG_F_IS_PLAIN, NULL);
1148         if (rc == 0)
1149                 rc = llog_destroy(env, handle);
1150
1151         rc2 = llog_close(env, handle);
1152         if (rc == 0)
1153                 rc = rc2;
1154         RETURN(rc);
1155 }
1156 EXPORT_SYMBOL(llog_erase);
1157
1158 /*
1159  * Helper function for write record in llog.
1160  * It hides all transaction handling from caller.
1161  * Valid only with local llog.
1162  */
1163 int llog_write(const struct lu_env *env, struct llog_handle *loghandle,
1164                struct llog_rec_hdr *rec, int idx)
1165 {
1166         struct dt_device        *dt;
1167         struct thandle          *th;
1168         bool                    need_cookie;
1169         int                     rc;
1170
1171         ENTRY;
1172
1173         LASSERT(loghandle);
1174         LASSERT(loghandle->lgh_ctxt);
1175         LASSERT(loghandle->lgh_obj != NULL);
1176
1177         dt = lu2dt_dev(loghandle->lgh_obj->do_lu.lo_dev);
1178
1179         th = dt_trans_create(env, dt);
1180         if (IS_ERR(th))
1181                 RETURN(PTR_ERR(th));
1182
1183         rc = llog_declare_write_rec(env, loghandle, rec, idx, th);
1184         if (rc)
1185                 GOTO(out_trans, rc);
1186
1187         th->th_wait_submit = 1;
1188         rc = dt_trans_start_local(env, dt, th);
1189         if (rc)
1190                 GOTO(out_trans, rc);
1191
1192         need_cookie = !(idx == LLOG_HEADER_IDX || idx == LLOG_NEXT_IDX);
1193
1194         down_write(&loghandle->lgh_lock);
1195         if (need_cookie) {
1196                 struct llog_thread_info *lti = llog_info(env);
1197
1198                 /* cookie comes from llog_process_thread */
1199                 rc = llog_write_rec(env, loghandle, rec, &lti->lgi_cookie,
1200                                     rec->lrh_index, th);
1201                 /* upper layer didn`t pass cookie so change rc */
1202                 rc = (rc == 1 ? 0 : rc);
1203         } else {
1204                 rc = llog_write_rec(env, loghandle, rec, NULL, idx, th);
1205         }
1206
1207         up_write(&loghandle->lgh_lock);
1208 out_trans:
1209         dt_trans_stop(env, dt, th);
1210         RETURN(rc);
1211 }
1212 EXPORT_SYMBOL(llog_write);
1213
1214 int llog_open(const struct lu_env *env, struct llog_ctxt *ctxt,
1215               struct llog_handle **lgh, struct llog_logid *logid,
1216               char *name, enum llog_open_param open_param)
1217 {
1218         int      raised;
1219         int      rc;
1220
1221         ENTRY;
1222
1223         LASSERT(ctxt);
1224         LASSERT(ctxt->loc_logops);
1225
1226         if (ctxt->loc_logops->lop_open == NULL) {
1227                 *lgh = NULL;
1228                 RETURN(-EOPNOTSUPP);
1229         }
1230
1231         *lgh = llog_alloc_handle();
1232         if (*lgh == NULL)
1233                 RETURN(-ENOMEM);
1234         (*lgh)->lgh_ctxt = ctxt;
1235         (*lgh)->lgh_logops = ctxt->loc_logops;
1236
1237         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
1238         if (!raised)
1239                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
1240         rc = ctxt->loc_logops->lop_open(env, *lgh, logid, name, open_param);
1241         if (!raised)
1242                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
1243         if (rc) {
1244                 llog_free_handle(*lgh);
1245                 *lgh = NULL;
1246         }
1247         RETURN(rc);
1248 }
1249 EXPORT_SYMBOL(llog_open);
1250
1251 int llog_close(const struct lu_env *env, struct llog_handle *loghandle)
1252 {
1253         struct llog_operations  *lop;
1254         int                      rc;
1255
1256         ENTRY;
1257
1258         rc = llog_handle2ops(loghandle, &lop);
1259         if (rc)
1260                 GOTO(out, rc);
1261         if (lop->lop_close == NULL)
1262                 GOTO(out, rc = -EOPNOTSUPP);
1263         rc = lop->lop_close(env, loghandle);
1264 out:
1265         llog_handle_put(loghandle);
1266         RETURN(rc);
1267 }
1268 EXPORT_SYMBOL(llog_close);
1269
1270 /**
1271  * Helper function to get the llog size in records. It is used by MGS
1272  * mostly to check that config llog exists and contains data.
1273  *
1274  * \param[in] env       execution environment
1275  * \param[in] ctxt      llog context
1276  * \param[in] name      llog name
1277  *
1278  * \retval              true if there are records in llog besides a header
1279  * \retval              false on error or llog without records
1280  */
1281 int llog_is_empty(const struct lu_env *env, struct llog_ctxt *ctxt,
1282                   char *name)
1283 {
1284         struct llog_handle      *llh;
1285         int                      rc = 0;
1286
1287         rc = llog_open(env, ctxt, &llh, NULL, name, LLOG_OPEN_EXISTS);
1288         if (rc < 0) {
1289                 if (likely(rc == -ENOENT))
1290                         rc = 0;
1291                 GOTO(out, rc);
1292         }
1293
1294         rc = llog_init_handle(env, llh, LLOG_F_IS_PLAIN, NULL);
1295         if (rc)
1296                 GOTO(out_close, rc);
1297         rc = llog_get_size(llh);
1298
1299 out_close:
1300         llog_close(env, llh);
1301 out:
1302         /* The header is record 1, the llog is still considered as empty
1303          * if there is only header */
1304         return (rc <= 1);
1305 }
1306 EXPORT_SYMBOL(llog_is_empty);
1307
1308 int llog_copy_handler(const struct lu_env *env, struct llog_handle *llh,
1309                       struct llog_rec_hdr *rec, void *data)
1310 {
1311         struct llog_handle      *copy_llh = data;
1312
1313         /* Append all records */
1314         return llog_write(env, copy_llh, rec, LLOG_NEXT_IDX);
1315 }
1316
1317 /* backup plain llog */
1318 int llog_backup(const struct lu_env *env, struct obd_device *obd,
1319                 struct llog_ctxt *ctxt, struct llog_ctxt *bctxt,
1320                 char *name, char *backup)
1321 {
1322         struct llog_handle      *llh, *bllh;
1323         int                      rc;
1324
1325         ENTRY;
1326
1327         /* open original log */
1328         rc = llog_open(env, ctxt, &llh, NULL, name, LLOG_OPEN_EXISTS);
1329         if (rc < 0) {
1330                 /* the -ENOENT case is also reported to the caller
1331                  * but silently so it should handle that if needed.
1332                  */
1333                 if (rc != -ENOENT)
1334                         CERROR("%s: failed to open log %s: rc = %d\n",
1335                                obd->obd_name, name, rc);
1336                 RETURN(rc);
1337         }
1338
1339         rc = llog_init_handle(env, llh, LLOG_F_IS_PLAIN, NULL);
1340         if (rc)
1341                 GOTO(out_close, rc);
1342
1343         /* Make sure there's no old backup log */
1344         rc = llog_erase(env, bctxt, NULL, backup);
1345         if (rc < 0 && rc != -ENOENT)
1346                 GOTO(out_close, rc);
1347
1348         /* open backup log */
1349         rc = llog_open_create(env, bctxt, &bllh, NULL, backup);
1350         if (rc) {
1351                 CERROR("%s: failed to open backup logfile %s: rc = %d\n",
1352                        obd->obd_name, backup, rc);
1353                 GOTO(out_close, rc);
1354         }
1355
1356         /* check that backup llog is not the same object as original one */
1357         if (llh->lgh_obj == bllh->lgh_obj) {
1358                 CERROR("%s: backup llog %s to itself (%s), objects %p/%p\n",
1359                        obd->obd_name, name, backup, llh->lgh_obj,
1360                        bllh->lgh_obj);
1361                 GOTO(out_backup, rc = -EEXIST);
1362         }
1363
1364         rc = llog_init_handle(env, bllh, LLOG_F_IS_PLAIN, NULL);
1365         if (rc)
1366                 GOTO(out_backup, rc);
1367
1368         /* Copy log record by record */
1369         rc = llog_process_or_fork(env, llh, llog_copy_handler, (void *)bllh,
1370                                   NULL, false);
1371         if (rc)
1372                 CERROR("%s: failed to backup log %s: rc = %d\n",
1373                        obd->obd_name, name, rc);
1374 out_backup:
1375         llog_close(env, bllh);
1376 out_close:
1377         llog_close(env, llh);
1378         RETURN(rc);
1379 }
1380 EXPORT_SYMBOL(llog_backup);
1381
1382 /* Get size of llog */
1383 __u64 llog_size(const struct lu_env *env, struct llog_handle *llh)
1384 {
1385         int rc;
1386         struct lu_attr la;
1387
1388         rc = llh->lgh_obj->do_ops->do_attr_get(env, llh->lgh_obj, &la);
1389         if (rc) {
1390                 CERROR("%s: attr_get failed for "DFID": rc = %d\n",
1391                        llh->lgh_ctxt->loc_obd->obd_name,
1392                        PFID(&llh->lgh_id.lgl_oi.oi_fid), rc);
1393                 return 0;
1394         }
1395
1396         return la.la_size;
1397 }
1398 EXPORT_SYMBOL(llog_size);
1399