drivers/staging/lustre/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.sun.com/software/products/lustre/docs/GPLv2.pdf
  19  *
  20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  21  * CA 95054 USA or visit www.sun.com if you need additional information or
  22  * have any questions.
  23  *
  24  * GPL HEADER END
  25  */
  26 /*
  27  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
  28  * Use is subject to license terms.
  29  *
  30  * Copyright (c) 2012, Intel Corporation.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  *
  36  * lustre/obdclass/llog.c
  37  *
  38  * OST<->MDS recovery logging infrastructure.
  39  * Invariants in implementation:
  40  * - we do not share logs among different OST<->MDS connections, so that
  41  *   if an OST or MDS fails it need only look at log(s) relevant to itself
  42  *
  43  * Author: Andreas Dilger <adilger@clusterfs.com>
  44  * Author: Alex Zhuravlev <bzzz@whamcloud.com>
  45  * Author: Mikhail Pershin <tappro@whamcloud.com>
  46  */
  47
  48 #define DEBUG_SUBSYSTEM S_LOG
  49
  50
  51 #include "../include/obd_class.h"
  52 #include "../include/lustre_log.h"
  53 #include "llog_internal.h"
  54
  55 /*
  56  * Allocate a new log or catalog handle
  57  * Used inside llog_open().
  58  */
  59 struct llog_handle *llog_alloc_handle(void)
  60 {
  61         struct llog_handle *loghandle;
  62
  63         OBD_ALLOC_PTR(loghandle);
  64         if (loghandle == NULL)
  65                 return NULL;
  66
  67         init_rwsem(&loghandle->lgh_lock);
  68         spin_lock_init(&loghandle->lgh_hdr_lock);
  69         INIT_LIST_HEAD(&loghandle->u.phd.phd_entry);
  70         atomic_set(&loghandle->lgh_refcount, 1);
  71
  72         return loghandle;
  73 }
  74
  75 /*
  76  * Free llog handle and header data if exists. Used in llog_close() only
  77  */
  78 void llog_free_handle(struct llog_handle *loghandle)
  79 {
  80         LASSERT(loghandle != NULL);
  81
  82         /* failed llog_init_handle */
  83         if (!loghandle->lgh_hdr)
  84                 goto out;
  85
  86         if (loghandle->lgh_hdr->llh_flags & LLOG_F_IS_PLAIN)
  87                 LASSERT(list_empty(&loghandle->u.phd.phd_entry));
  88         else if (loghandle->lgh_hdr->llh_flags & LLOG_F_IS_CAT)
  89                 LASSERT(list_empty(&loghandle->u.chd.chd_head));
  90         LASSERT(sizeof(*(loghandle->lgh_hdr)) == LLOG_CHUNK_SIZE);
  91         OBD_FREE(loghandle->lgh_hdr, LLOG_CHUNK_SIZE);
  92 out:
  93         OBD_FREE_PTR(loghandle);
  94 }
  95
  96 void llog_handle_get(struct llog_handle *loghandle)
  97 {
  98         atomic_inc(&loghandle->lgh_refcount);
  99 }
 100
 101 void llog_handle_put(struct llog_handle *loghandle)
 102 {
 103         LASSERT(atomic_read(&loghandle->lgh_refcount) > 0);
 104         if (atomic_dec_and_test(&loghandle->lgh_refcount))
 105                 llog_free_handle(loghandle);
 106 }
 107
 108 /* returns negative on error; 0 if success; 1 if success & log destroyed */
 109 int llog_cancel_rec(const struct lu_env *env, struct llog_handle *loghandle,
 110                     int index)
 111 {
 112         struct llog_log_hdr *llh = loghandle->lgh_hdr;
 113         int rc = 0;
 114
 115         CDEBUG(D_RPCTRACE, "Canceling %d in log "DOSTID"\n",
 116                index, POSTID(&loghandle->lgh_id.lgl_oi));
 117
 118         if (index == 0) {
 119                 CERROR("Can't cancel index 0 which is header\n");
 120                 return -EINVAL;
 121         }
 122
 123         spin_lock(&loghandle->lgh_hdr_lock);
 124         if (!ext2_clear_bit(index, llh->llh_bitmap)) {
 125                 spin_unlock(&loghandle->lgh_hdr_lock);
 126                 CDEBUG(D_RPCTRACE, "Catalog index %u already clear?\n", index);
 127                 return -ENOENT;
 128         }
 129
 130         llh->llh_count--;
 131
 132         if ((llh->llh_flags & LLOG_F_ZAP_WHEN_EMPTY) &&
 133             (llh->llh_count == 1) &&
 134             (loghandle->lgh_last_idx == (LLOG_BITMAP_BYTES * 8) - 1)) {
 135                 spin_unlock(&loghandle->lgh_hdr_lock);
 136                 rc = llog_destroy(env, loghandle);
 137                 if (rc < 0) {
 138                         CERROR("%s: can't destroy empty llog #"DOSTID
 139                                "#%08x: rc = %d\n",
 140                                loghandle->lgh_ctxt->loc_obd->obd_name,
 141                                POSTID(&loghandle->lgh_id.lgl_oi),
 142                                loghandle->lgh_id.lgl_ogen, rc);
 143                         GOTO(out_err, rc);
 144                 }
 145                 return 1;
 146         }
 147         spin_unlock(&loghandle->lgh_hdr_lock);
 148
 149         rc = llog_write(env, loghandle, &llh->llh_hdr, NULL, 0, NULL, 0);
 150         if (rc < 0) {
 151                 CERROR("%s: fail to write header for llog #"DOSTID
 152                        "#%08x: rc = %d\n",
 153                        loghandle->lgh_ctxt->loc_obd->obd_name,
 154                        POSTID(&loghandle->lgh_id.lgl_oi),
 155                        loghandle->lgh_id.lgl_ogen, rc);
 156                 GOTO(out_err, rc);
 157         }
 158         return 0;
 159 out_err:
 160         spin_lock(&loghandle->lgh_hdr_lock);
 161         ext2_set_bit(index, llh->llh_bitmap);
 162         llh->llh_count++;
 163         spin_unlock(&loghandle->lgh_hdr_lock);
 164         return rc;
 165 }
 166 EXPORT_SYMBOL(llog_cancel_rec);
 167
 168 static int llog_read_header(const struct lu_env *env,
 169                             struct llog_handle *handle,
 170                             struct obd_uuid *uuid)
 171 {
 172         struct llog_operations *lop;
 173         int rc;
 174
 175         rc = llog_handle2ops(handle, &lop);
 176         if (rc)
 177                 return rc;
 178
 179         if (lop->lop_read_header == NULL)
 180                 return -EOPNOTSUPP;
 181
 182         rc = lop->lop_read_header(env, handle);
 183         if (rc == LLOG_EEMPTY) {
 184                 struct llog_log_hdr *llh = handle->lgh_hdr;
 185
 186                 handle->lgh_last_idx = 0; /* header is record with index 0 */
 187                 llh->llh_count = 1;      /* for the header record */
 188                 llh->llh_hdr.lrh_type = LLOG_HDR_MAGIC;
 189                 llh->llh_hdr.lrh_len = llh->llh_tail.lrt_len = LLOG_CHUNK_SIZE;
 190                 llh->llh_hdr.lrh_index = llh->llh_tail.lrt_index = 0;
 191                 llh->llh_timestamp = get_seconds();
 192                 if (uuid)
 193                         memcpy(&llh->llh_tgtuuid, uuid,
 194                                sizeof(llh->llh_tgtuuid));
 195                 llh->llh_bitmap_offset = offsetof(typeof(*llh), llh_bitmap);
 196                 ext2_set_bit(0, llh->llh_bitmap);
 197                 rc = 0;
 198         }
 199         return rc;
 200 }
 201
 202 int llog_init_handle(const struct lu_env *env, struct llog_handle *handle,
 203                      int flags, struct obd_uuid *uuid)
 204 {
 205         struct llog_log_hdr     *llh;
 206         int                      rc;
 207
 208         LASSERT(handle->lgh_hdr == NULL);
 209
 210         OBD_ALLOC_PTR(llh);
 211         if (llh == NULL)
 212                 return -ENOMEM;
 213         handle->lgh_hdr = llh;
 214         /* first assign flags to use llog_client_ops */
 215         llh->llh_flags = flags;
 216         rc = llog_read_header(env, handle, uuid);
 217         if (rc == 0) {
 218                 if (unlikely((llh->llh_flags & LLOG_F_IS_PLAIN &&
 219                               flags & LLOG_F_IS_CAT) ||
 220                              (llh->llh_flags & LLOG_F_IS_CAT &&
 221                               flags & LLOG_F_IS_PLAIN))) {
 222                         CERROR("%s: llog type is %s but initializing %s\n",
 223                                handle->lgh_ctxt->loc_obd->obd_name,
 224                                llh->llh_flags & LLOG_F_IS_CAT ?
 225                                "catalog" : "plain",
 226                                flags & LLOG_F_IS_CAT ? "catalog" : "plain");
 227                         GOTO(out, rc = -EINVAL);
 228                 } else if (llh->llh_flags &
 229                            (LLOG_F_IS_PLAIN | LLOG_F_IS_CAT)) {
 230                         /*
 231                          * it is possible to open llog without specifying llog
 232                          * type so it is taken from llh_flags
 233                          */
 234                         flags = llh->llh_flags;
 235                 } else {
 236                         /* for some reason the llh_flags has no type set */
 237                         CERROR("llog type is not specified!\n");
 238                         GOTO(out, rc = -EINVAL);
 239                 }
 240                 if (unlikely(uuid &&
 241                              !obd_uuid_equals(uuid, &llh->llh_tgtuuid))) {
 242                         CERROR("%s: llog uuid mismatch: %s/%s\n",
 243                                handle->lgh_ctxt->loc_obd->obd_name,
 244                                (char *)uuid->uuid,
 245                                (char *)llh->llh_tgtuuid.uuid);
 246                         GOTO(out, rc = -EEXIST);
 247                 }
 248         }
 249         if (flags & LLOG_F_IS_CAT) {
 250                 LASSERT(list_empty(&handle->u.chd.chd_head));
 251                 INIT_LIST_HEAD(&handle->u.chd.chd_head);
 252                 llh->llh_size = sizeof(struct llog_logid_rec);
 253         } else if (!(flags & LLOG_F_IS_PLAIN)) {
 254                 CERROR("%s: unknown flags: %#x (expected %#x or %#x)\n",
 255                        handle->lgh_ctxt->loc_obd->obd_name,
 256                        flags, LLOG_F_IS_CAT, LLOG_F_IS_PLAIN);
 257                 rc = -EINVAL;
 258         }
 259 out:
 260         if (rc) {
 261                 OBD_FREE_PTR(llh);
 262                 handle->lgh_hdr = NULL;
 263         }
 264         return rc;
 265 }
 266 EXPORT_SYMBOL(llog_init_handle);
 267
 268 static int llog_process_thread(void *arg)
 269 {
 270         struct llog_process_info        *lpi = arg;
 271         struct llog_handle              *loghandle = lpi->lpi_loghandle;
 272         struct llog_log_hdr             *llh = loghandle->lgh_hdr;
 273         struct llog_process_cat_data    *cd  = lpi->lpi_catdata;
 274         char                            *buf;
 275         __u64                            cur_offset = LLOG_CHUNK_SIZE;
 276         __u64                            last_offset;
 277         int                              rc = 0, index = 1, last_index;
 278         int                              saved_index = 0;
 279         int                              last_called_index = 0;
 280
 281         LASSERT(llh);
 282
 283         OBD_ALLOC(buf, LLOG_CHUNK_SIZE);
 284         if (!buf) {
 285                 lpi->lpi_rc = -ENOMEM;
 286                 return 0;
 287         }
 288
 289         if (cd != NULL) {
 290                 last_called_index = cd->lpcd_first_idx;
 291                 index = cd->lpcd_first_idx + 1;
 292         }
 293         if (cd != NULL && cd->lpcd_last_idx)
 294                 last_index = cd->lpcd_last_idx;
 295         else
 296                 last_index = LLOG_BITMAP_BYTES * 8 - 1;
 297
 298         while (rc == 0) {
 299                 struct llog_rec_hdr *rec;
 300
 301                 /* skip records not set in bitmap */
 302                 while (index <= last_index &&
 303                        !ext2_test_bit(index, llh->llh_bitmap))
 304                         ++index;
 305
 306                 LASSERT(index <= last_index + 1);
 307                 if (index == last_index + 1)
 308                         break;
 309 repeat:
 310                 CDEBUG(D_OTHER, "index: %d last_index %d\n",
 311                        index, last_index);
 312
 313                 /* get the buf with our target record; avoid old garbage */
 314                 memset(buf, 0, LLOG_CHUNK_SIZE);
 315                 last_offset = cur_offset;
 316                 rc = llog_next_block(lpi->lpi_env, loghandle, &saved_index,
 317                                      index, &cur_offset, buf, LLOG_CHUNK_SIZE);
 318                 if (rc)
 319                         GOTO(out, rc);
 320
 321                 /* NB: when rec->lrh_len is accessed it is already swabbed
 322                  * since it is used at the "end" of the loop and the rec
 323                  * swabbing is done at the beginning of the loop. */
 324                 for (rec = (struct llog_rec_hdr *)buf;
 325                      (char *)rec < buf + LLOG_CHUNK_SIZE;
 326                      rec = (struct llog_rec_hdr *)((char *)rec + rec->lrh_len)){
 327
 328                         CDEBUG(D_OTHER, "processing rec 0x%p type %#x\n",
 329                                rec, rec->lrh_type);
 330
 331                         if (LLOG_REC_HDR_NEEDS_SWABBING(rec))
 332                                 lustre_swab_llog_rec(rec);
 333
 334                         CDEBUG(D_OTHER, "after swabbing, type=%#x idx=%d\n",
 335                                rec->lrh_type, rec->lrh_index);
 336
 337                         if (rec->lrh_index == 0) {
 338                                 /* probably another rec just got added? */
 339                                 if (index <= loghandle->lgh_last_idx)
 340                                         GOTO(repeat, rc = 0);
 341                                 GOTO(out, rc = 0); /* no more records */
 342                         }
 343                         if (rec->lrh_len == 0 ||
 344                             rec->lrh_len > LLOG_CHUNK_SIZE) {
 345                                 CWARN("invalid length %d in llog record for "
 346                                       "index %d/%d\n", rec->lrh_len,
 347                                       rec->lrh_index, index);
 348                                 GOTO(out, rc = -EINVAL);
 349                         }
 350
 351                         if (rec->lrh_index < index) {
 352                                 CDEBUG(D_OTHER, "skipping lrh_index %d\n",
 353                                        rec->lrh_index);
 354                                 continue;
 355                         }
 356
 357                         CDEBUG(D_OTHER,
 358                                "lrh_index: %d lrh_len: %d (%d remains)\n",
 359                                rec->lrh_index, rec->lrh_len,
 360                                (int)(buf + LLOG_CHUNK_SIZE - (char *)rec));
 361
 362                         loghandle->lgh_cur_idx = rec->lrh_index;
 363                         loghandle->lgh_cur_offset = (char *)rec - (char *)buf +
 364                                                     last_offset;
 365
 366                         /* if set, process the callback on this record */
 367                         if (ext2_test_bit(index, llh->llh_bitmap)) {
 368                                 rc = lpi->lpi_cb(lpi->lpi_env, loghandle, rec,
 369                                                  lpi->lpi_cbdata);
 370                                 last_called_index = index;
 371                                 if (rc == LLOG_PROC_BREAK) {
 372                                         GOTO(out, rc);
 373                                 } else if (rc == LLOG_DEL_RECORD) {
 374                                         llog_cancel_rec(lpi->lpi_env,
 375                                                         loghandle,
 376                                                         rec->lrh_index);
 377                                         rc = 0;
 378                                 }
 379                                 if (rc)
 380                                         GOTO(out, rc);
 381                         } else {
 382                                 CDEBUG(D_OTHER, "Skipped index %d\n", index);
 383                         }
 384
 385                         /* next record, still in buffer? */
 386                         ++index;
 387                         if (index > last_index)
 388                                 GOTO(out, rc = 0);
 389                 }
 390         }
 391
 392 out:
 393         if (cd != NULL)
 394                 cd->lpcd_last_idx = last_called_index;
 395
 396         OBD_FREE(buf, LLOG_CHUNK_SIZE);
 397         lpi->lpi_rc = rc;
 398         return 0;
 399 }
 400
 401 static int llog_process_thread_daemonize(void *arg)
 402 {
 403         struct llog_process_info        *lpi = arg;
 404         struct lu_env                    env;
 405         int                              rc;
 406
 407         unshare_fs_struct();
 408
 409         /* client env has no keys, tags is just 0 */
 410         rc = lu_env_init(&env, LCT_LOCAL | LCT_MG_THREAD);
 411         if (rc)
 412                 goto out;
 413         lpi->lpi_env = &env;
 414
 415         rc = llog_process_thread(arg);
 416
 417         lu_env_fini(&env);
 418 out:
 419         complete(&lpi->lpi_completion);
 420         return rc;
 421 }
 422
 423 int llog_process_or_fork(const struct lu_env *env,
 424                          struct llog_handle *loghandle,
 425                          llog_cb_t cb, void *data, void *catdata, bool fork)
 426 {
 427         struct llog_process_info *lpi;
 428         int                   rc;
 429
 430         OBD_ALLOC_PTR(lpi);
 431         if (lpi == NULL) {
 432                 CERROR("cannot alloc pointer\n");
 433                 return -ENOMEM;
 434         }
 435         lpi->lpi_loghandle = loghandle;
 436         lpi->lpi_cb     = cb;
 437         lpi->lpi_cbdata    = data;
 438         lpi->lpi_catdata   = catdata;
 439
 440         if (fork) {
 441                 /* The new thread can't use parent env,
 442                  * init the new one in llog_process_thread_daemonize. */
 443                 lpi->lpi_env = NULL;
 444                 init_completion(&lpi->lpi_completion);
 445                 rc = PTR_ERR(kthread_run(llog_process_thread_daemonize, lpi,
 446                                              "llog_process_thread"));
 447                 if (IS_ERR_VALUE(rc)) {
 448                         CERROR("%s: cannot start thread: rc = %d\n",
 449                                loghandle->lgh_ctxt->loc_obd->obd_name, rc);
 450                         OBD_FREE_PTR(lpi);
 451                         return rc;
 452                 }
 453                 wait_for_completion(&lpi->lpi_completion);
 454         } else {
 455                 lpi->lpi_env = env;
 456                 llog_process_thread(lpi);
 457         }
 458         rc = lpi->lpi_rc;
 459         OBD_FREE_PTR(lpi);
 460         return rc;
 461 }
 462 EXPORT_SYMBOL(llog_process_or_fork);
 463
 464 int llog_process(const struct lu_env *env, struct llog_handle *loghandle,
 465                  llog_cb_t cb, void *data, void *catdata)
 466 {
 467         return llog_process_or_fork(env, loghandle, cb, data, catdata, true);
 468 }
 469 EXPORT_SYMBOL(llog_process);
 470
 471 int llog_reverse_process(const struct lu_env *env,
 472                          struct llog_handle *loghandle, llog_cb_t cb,
 473                          void *data, void *catdata)
 474 {
 475         struct llog_log_hdr *llh = loghandle->lgh_hdr;
 476         struct llog_process_cat_data *cd = catdata;
 477         void *buf;
 478         int rc = 0, first_index = 1, index, idx;
 479
 480         OBD_ALLOC(buf, LLOG_CHUNK_SIZE);
 481         if (!buf)
 482                 return -ENOMEM;
 483
 484         if (cd != NULL)
 485                 first_index = cd->lpcd_first_idx + 1;
 486         if (cd != NULL && cd->lpcd_last_idx)
 487                 index = cd->lpcd_last_idx;
 488         else
 489                 index = LLOG_BITMAP_BYTES * 8 - 1;
 490
 491         while (rc == 0) {
 492                 struct llog_rec_hdr *rec;
 493                 struct llog_rec_tail *tail;
 494
 495                 /* skip records not set in bitmap */
 496                 while (index >= first_index &&
 497                        !ext2_test_bit(index, llh->llh_bitmap))
 498                         --index;
 499
 500                 LASSERT(index >= first_index - 1);
 501                 if (index == first_index - 1)
 502                         break;
 503
 504                 /* get the buf with our target record; avoid old garbage */
 505                 memset(buf, 0, LLOG_CHUNK_SIZE);
 506                 rc = llog_prev_block(env, loghandle, index, buf,
 507                                      LLOG_CHUNK_SIZE);
 508                 if (rc)
 509                         GOTO(out, rc);
 510
 511                 rec = buf;
 512                 idx = rec->lrh_index;
 513                 CDEBUG(D_RPCTRACE, "index %u : idx %u\n", index, idx);
 514                 while (idx < index) {
 515                         rec = (void *)rec + rec->lrh_len;
 516                         if (LLOG_REC_HDR_NEEDS_SWABBING(rec))
 517                                 lustre_swab_llog_rec(rec);
 518                         idx ++;
 519                 }
 520                 LASSERT(idx == index);
 521                 tail = (void *)rec + rec->lrh_len - sizeof(*tail);
 522
 523                 /* process records in buffer, starting where we found one */
 524                 while ((void *)tail > buf) {
 525                         if (tail->lrt_index == 0)
 526                                 GOTO(out, rc = 0); /* no more records */
 527
 528                         /* if set, process the callback on this record */
 529                         if (ext2_test_bit(index, llh->llh_bitmap)) {
 530                                 rec = (void *)tail - tail->lrt_len +
 531                                       sizeof(*tail);
 532
 533                                 rc = cb(env, loghandle, rec, data);
 534                                 if (rc == LLOG_PROC_BREAK) {
 535                                         GOTO(out, rc);
 536                                 } else if (rc == LLOG_DEL_RECORD) {
 537                                         llog_cancel_rec(env, loghandle,
 538                                                         tail->lrt_index);
 539                                         rc = 0;
 540                                 }
 541                                 if (rc)
 542                                         GOTO(out, rc);
 543                         }
 544
 545                         /* previous record, still in buffer? */
 546                         --index;
 547                         if (index < first_index)
 548                                 GOTO(out, rc = 0);
 549                         tail = (void *)tail - tail->lrt_len;
 550                 }
 551         }
 552
 553 out:
 554         if (buf)
 555                 OBD_FREE(buf, LLOG_CHUNK_SIZE);
 556         return rc;
 557 }
 558 EXPORT_SYMBOL(llog_reverse_process);
 559
 560 /**
 561  * new llog API
 562  *
 563  * API functions:
 564  *      llog_open - open llog, may not exist
 565  *      llog_exist - check if llog exists
 566  *      llog_close - close opened llog, pair for open, frees llog_handle
 567  *      llog_declare_create - declare llog creation
 568  *      llog_create - create new llog on disk, need transaction handle
 569  *      llog_declare_write_rec - declaration of llog write
 570  *      llog_write_rec - write llog record on disk, need transaction handle
 571  *      llog_declare_add - declare llog catalog record addition
 572  *      llog_add - add llog record in catalog, need transaction handle
 573  */
 574 int llog_exist(struct llog_handle *loghandle)
 575 {
 576         struct llog_operations  *lop;
 577         int                      rc;
 578
 579         rc = llog_handle2ops(loghandle, &lop);
 580         if (rc)
 581                 return rc;
 582         if (lop->lop_exist == NULL)
 583                 return -EOPNOTSUPP;
 584
 585         rc = lop->lop_exist(loghandle);
 586         return rc;
 587 }
 588 EXPORT_SYMBOL(llog_exist);
 589
 590 int llog_declare_create(const struct lu_env *env,
 591                         struct llog_handle *loghandle, struct thandle *th)
 592 {
 593         struct llog_operations  *lop;
 594         int                      raised, rc;
 595
 596         rc = llog_handle2ops(loghandle, &lop);
 597         if (rc)
 598                 return rc;
 599         if (lop->lop_declare_create == NULL)
 600                 return -EOPNOTSUPP;
 601
 602         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 603         if (!raised)
 604                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 605         rc = lop->lop_declare_create(env, loghandle, th);
 606         if (!raised)
 607                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 608         return rc;
 609 }
 610 EXPORT_SYMBOL(llog_declare_create);
 611
 612 int llog_create(const struct lu_env *env, struct llog_handle *handle,
 613                 struct thandle *th)
 614 {
 615         struct llog_operations  *lop;
 616         int                      raised, rc;
 617
 618         rc = llog_handle2ops(handle, &lop);
 619         if (rc)
 620                 return rc;
 621         if (lop->lop_create == NULL)
 622                 return -EOPNOTSUPP;
 623
 624         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 625         if (!raised)
 626                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 627         rc = lop->lop_create(env, handle, th);
 628         if (!raised)
 629                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 630         return rc;
 631 }
 632 EXPORT_SYMBOL(llog_create);
 633
 634 int llog_declare_write_rec(const struct lu_env *env,
 635                            struct llog_handle *handle,
 636                            struct llog_rec_hdr *rec, int idx,
 637                            struct thandle *th)
 638 {
 639         struct llog_operations  *lop;
 640         int                      raised, rc;
 641
 642         rc = llog_handle2ops(handle, &lop);
 643         if (rc)
 644                 return rc;
 645         LASSERT(lop);
 646         if (lop->lop_declare_write_rec == NULL)
 647                 return -EOPNOTSUPP;
 648
 649         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 650         if (!raised)
 651                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 652         rc = lop->lop_declare_write_rec(env, handle, rec, idx, th);
 653         if (!raised)
 654                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 655         return rc;
 656 }
 657 EXPORT_SYMBOL(llog_declare_write_rec);
 658
 659 int llog_write_rec(const struct lu_env *env, struct llog_handle *handle,
 660                    struct llog_rec_hdr *rec, struct llog_cookie *logcookies,
 661                    int numcookies, void *buf, int idx, struct thandle *th)
 662 {
 663         struct llog_operations  *lop;
 664         int                      raised, rc, buflen;
 665
 666         rc = llog_handle2ops(handle, &lop);
 667         if (rc)
 668                 return rc;
 669
 670         LASSERT(lop);
 671         if (lop->lop_write_rec == NULL)
 672                 return -EOPNOTSUPP;
 673
 674         if (buf)
 675                 buflen = rec->lrh_len + sizeof(struct llog_rec_hdr) +
 676                          sizeof(struct llog_rec_tail);
 677         else
 678                 buflen = rec->lrh_len;
 679         LASSERT(cfs_size_round(buflen) == buflen);
 680
 681         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 682         if (!raised)
 683                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 684         rc = lop->lop_write_rec(env, handle, rec, logcookies, numcookies,
 685                                 buf, idx, th);
 686         if (!raised)
 687                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 688         return rc;
 689 }
 690 EXPORT_SYMBOL(llog_write_rec);
 691
 692 int llog_add(const struct lu_env *env, struct llog_handle *lgh,
 693              struct llog_rec_hdr *rec, struct llog_cookie *logcookies,
 694              void *buf, struct thandle *th)
 695 {
 696         int raised, rc;
 697
 698         if (lgh->lgh_logops->lop_add == NULL)
 699                 return -EOPNOTSUPP;
 700
 701         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 702         if (!raised)
 703                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 704         rc = lgh->lgh_logops->lop_add(env, lgh, rec, logcookies, buf, th);
 705         if (!raised)
 706                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 707         return rc;
 708 }
 709 EXPORT_SYMBOL(llog_add);
 710
 711 int llog_declare_add(const struct lu_env *env, struct llog_handle *lgh,
 712                      struct llog_rec_hdr *rec, struct thandle *th)
 713 {
 714         int raised, rc;
 715
 716         if (lgh->lgh_logops->lop_declare_add == NULL)
 717                 return -EOPNOTSUPP;
 718
 719         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 720         if (!raised)
 721                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 722         rc = lgh->lgh_logops->lop_declare_add(env, lgh, rec, th);
 723         if (!raised)
 724                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 725         return rc;
 726 }
 727 EXPORT_SYMBOL(llog_declare_add);
 728
 729 /**
 730  * Helper function to open llog or create it if doesn't exist.
 731  * It hides all transaction handling from caller.
 732  */
 733 int llog_open_create(const struct lu_env *env, struct llog_ctxt *ctxt,
 734                      struct llog_handle **res, struct llog_logid *logid,
 735                      char *name)
 736 {
 737         struct dt_device        *d;
 738         struct thandle          *th;
 739         int                      rc;
 740
 741         rc = llog_open(env, ctxt, res, logid, name, LLOG_OPEN_NEW);
 742         if (rc)
 743                 return rc;
 744
 745         if (llog_exist(*res))
 746                 return 0;
 747
 748         LASSERT((*res)->lgh_obj != NULL);
 749
 750         d = lu2dt_dev((*res)->lgh_obj->do_lu.lo_dev);
 751
 752         th = dt_trans_create(env, d);
 753         if (IS_ERR(th))
 754                 GOTO(out, rc = PTR_ERR(th));
 755
 756         rc = llog_declare_create(env, *res, th);
 757         if (rc == 0) {
 758                 rc = dt_trans_start_local(env, d, th);
 759                 if (rc == 0)
 760                         rc = llog_create(env, *res, th);
 761         }
 762         dt_trans_stop(env, d, th);
 763 out:
 764         if (rc)
 765                 llog_close(env, *res);
 766         return rc;
 767 }
 768 EXPORT_SYMBOL(llog_open_create);
 769
 770 /**
 771  * Helper function to delete existent llog.
 772  */
 773 int llog_erase(const struct lu_env *env, struct llog_ctxt *ctxt,
 774                struct llog_logid *logid, char *name)
 775 {
 776         struct llog_handle      *handle;
 777         int                      rc = 0, rc2;
 778
 779         /* nothing to erase */
 780         if (name == NULL && logid == NULL)
 781                 return 0;
 782
 783         rc = llog_open(env, ctxt, &handle, logid, name, LLOG_OPEN_EXISTS);
 784         if (rc < 0)
 785                 return rc;
 786
 787         rc = llog_init_handle(env, handle, LLOG_F_IS_PLAIN, NULL);
 788         if (rc == 0)
 789                 rc = llog_destroy(env, handle);
 790
 791         rc2 = llog_close(env, handle);
 792         if (rc == 0)
 793                 rc = rc2;
 794         return rc;
 795 }
 796 EXPORT_SYMBOL(llog_erase);
 797
 798 /*
 799  * Helper function for write record in llog.
 800  * It hides all transaction handling from caller.
 801  * Valid only with local llog.
 802  */
 803 int llog_write(const struct lu_env *env, struct llog_handle *loghandle,
 804                struct llog_rec_hdr *rec, struct llog_cookie *reccookie,
 805                int cookiecount, void *buf, int idx)
 806 {
 807         struct dt_device        *dt;
 808         struct thandle          *th;
 809         int                      rc;
 810
 811         LASSERT(loghandle);
 812         LASSERT(loghandle->lgh_ctxt);
 813         LASSERT(loghandle->lgh_obj != NULL);
 814
 815         dt = lu2dt_dev(loghandle->lgh_obj->do_lu.lo_dev);
 816
 817         th = dt_trans_create(env, dt);
 818         if (IS_ERR(th))
 819                 return PTR_ERR(th);
 820
 821         rc = llog_declare_write_rec(env, loghandle, rec, idx, th);
 822         if (rc)
 823                 GOTO(out_trans, rc);
 824
 825         rc = dt_trans_start_local(env, dt, th);
 826         if (rc)
 827                 GOTO(out_trans, rc);
 828
 829         down_write(&loghandle->lgh_lock);
 830         rc = llog_write_rec(env, loghandle, rec, reccookie,
 831                             cookiecount, buf, idx, th);
 832         up_write(&loghandle->lgh_lock);
 833 out_trans:
 834         dt_trans_stop(env, dt, th);
 835         return rc;
 836 }
 837 EXPORT_SYMBOL(llog_write);
 838
 839 int llog_open(const struct lu_env *env, struct llog_ctxt *ctxt,
 840               struct llog_handle **lgh, struct llog_logid *logid,
 841               char *name, enum llog_open_param open_param)
 842 {
 843         int      raised;
 844         int      rc;
 845
 846         LASSERT(ctxt);
 847         LASSERT(ctxt->loc_logops);
 848
 849         if (ctxt->loc_logops->lop_open == NULL) {
 850                 *lgh = NULL;
 851                 return -EOPNOTSUPP;
 852         }
 853
 854         *lgh = llog_alloc_handle();
 855         if (*lgh == NULL)
 856                 return -ENOMEM;
 857         (*lgh)->lgh_ctxt = ctxt;
 858         (*lgh)->lgh_logops = ctxt->loc_logops;
 859
 860         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 861         if (!raised)
 862                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 863         rc = ctxt->loc_logops->lop_open(env, *lgh, logid, name, open_param);
 864         if (!raised)
 865                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 866         if (rc) {
 867                 llog_free_handle(*lgh);
 868                 *lgh = NULL;
 869         }
 870         return rc;
 871 }
 872 EXPORT_SYMBOL(llog_open);
 873
 874 int llog_close(const struct lu_env *env, struct llog_handle *loghandle)
 875 {
 876         struct llog_operations  *lop;
 877         int                      rc;
 878
 879         rc = llog_handle2ops(loghandle, &lop);
 880         if (rc)
 881                 GOTO(out, rc);
 882         if (lop->lop_close == NULL)
 883                 GOTO(out, rc = -EOPNOTSUPP);
 884         rc = lop->lop_close(env, loghandle);
 885 out:
 886         llog_handle_put(loghandle);
 887         return rc;
 888 }
 889 EXPORT_SYMBOL(llog_close);
 890
 891 int llog_is_empty(const struct lu_env *env, struct llog_ctxt *ctxt,
 892                   char *name)
 893 {
 894         struct llog_handle      *llh;
 895         int                      rc = 0;
 896
 897         rc = llog_open(env, ctxt, &llh, NULL, name, LLOG_OPEN_EXISTS);
 898         if (rc < 0) {
 899                 if (likely(rc == -ENOENT))
 900                         rc = 0;
 901                 GOTO(out, rc);
 902         }
 903
 904         rc = llog_init_handle(env, llh, LLOG_F_IS_PLAIN, NULL);
 905         if (rc)
 906                 GOTO(out_close, rc);
 907         rc = llog_get_size(llh);
 908
 909 out_close:
 910         llog_close(env, llh);
 911 out:
 912         /* header is record 1 */
 913         return rc <= 1;
 914 }
 915 EXPORT_SYMBOL(llog_is_empty);
 916
 917 int llog_copy_handler(const struct lu_env *env, struct llog_handle *llh,
 918                       struct llog_rec_hdr *rec, void *data)
 919 {
 920         struct llog_handle      *copy_llh = data;
 921
 922         /* Append all records */
 923         return llog_write(env, copy_llh, rec, NULL, 0, NULL, -1);
 924 }
 925 EXPORT_SYMBOL(llog_copy_handler);
 926
 927 /* backup plain llog */
 928 int llog_backup(const struct lu_env *env, struct obd_device *obd,
 929                 struct llog_ctxt *ctxt, struct llog_ctxt *bctxt,
 930                 char *name, char *backup)
 931 {
 932         struct llog_handle      *llh, *bllh;
 933         int                      rc;
 934
 935
 936
 937         /* open original log */
 938         rc = llog_open(env, ctxt, &llh, NULL, name, LLOG_OPEN_EXISTS);
 939         if (rc < 0) {
 940                 /* the -ENOENT case is also reported to the caller
 941                  * but silently so it should handle that if needed.
 942                  */
 943                 if (rc != -ENOENT)
 944                         CERROR("%s: failed to open log %s: rc = %d\n",
 945                                obd->obd_name, name, rc);
 946                 return rc;
 947         }
 948
 949         rc = llog_init_handle(env, llh, LLOG_F_IS_PLAIN, NULL);
 950         if (rc)
 951                 GOTO(out_close, rc);
 952
 953         /* Make sure there's no old backup log */
 954         rc = llog_erase(env, bctxt, NULL, backup);
 955         if (rc < 0 && rc != -ENOENT)
 956                 GOTO(out_close, rc);
 957
 958         /* open backup log */
 959         rc = llog_open_create(env, bctxt, &bllh, NULL, backup);
 960         if (rc) {
 961                 CERROR("%s: failed to open backup logfile %s: rc = %d\n",
 962                        obd->obd_name, backup, rc);
 963                 GOTO(out_close, rc);
 964         }
 965
 966         /* check that backup llog is not the same object as original one */
 967         if (llh->lgh_obj == bllh->lgh_obj) {
 968                 CERROR("%s: backup llog %s to itself (%s), objects %p/%p\n",
 969                        obd->obd_name, name, backup, llh->lgh_obj,
 970                        bllh->lgh_obj);
 971                 GOTO(out_backup, rc = -EEXIST);
 972         }
 973
 974         rc = llog_init_handle(env, bllh, LLOG_F_IS_PLAIN, NULL);
 975         if (rc)
 976                 GOTO(out_backup, rc);
 977
 978         /* Copy log record by record */
 979         rc = llog_process_or_fork(env, llh, llog_copy_handler, (void *)bllh,
 980                                   NULL, false);
 981         if (rc)
 982                 CERROR("%s: failed to backup log %s: rc = %d\n",
 983                        obd->obd_name, name, rc);
 984 out_backup:
 985         llog_close(env, bllh);
 986 out_close:
 987         llog_close(env, llh);
 988         return rc;
 989 }
 990 EXPORT_SYMBOL(llog_backup);