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