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, 2013, 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 #ifndef __KERNEL__
  51 #include <liblustre.h>
  52 #endif
  53
  54 #include <obd_class.h>
  55 #include <lustre_log.h>
  56 #include "llog_internal.h"
  57
  58 /*
  59  * Allocate a new log or catalog handle
  60  * Used inside llog_open().
  61  */
  62 struct llog_handle *llog_alloc_handle(void)
  63 {
  64         struct llog_handle *loghandle;
  65
  66         OBD_ALLOC_PTR(loghandle);
  67         if (loghandle == NULL)
  68                 return NULL;
  69
  70         init_rwsem(&loghandle->lgh_lock);
  71         spin_lock_init(&loghandle->lgh_hdr_lock);
  72         CFS_INIT_LIST_HEAD(&loghandle->u.phd.phd_entry);
  73         atomic_set(&loghandle->lgh_refcount, 1);
  74
  75         return loghandle;
  76 }
  77
  78 /*
  79  * Free llog handle and header data if exists. Used in llog_close() only
  80  */
  81 void llog_free_handle(struct llog_handle *loghandle)
  82 {
  83         LASSERT(loghandle != NULL);
  84
  85         /* failed llog_init_handle */
  86         if (!loghandle->lgh_hdr)
  87                 goto out;
  88
  89         if (loghandle->lgh_hdr->llh_flags & LLOG_F_IS_PLAIN)
  90                 LASSERT(cfs_list_empty(&loghandle->u.phd.phd_entry));
  91         else if (loghandle->lgh_hdr->llh_flags & LLOG_F_IS_CAT)
  92                 LASSERT(cfs_list_empty(&loghandle->u.chd.chd_head));
  93         LASSERT(sizeof(*(loghandle->lgh_hdr)) == LLOG_CHUNK_SIZE);
  94         OBD_FREE(loghandle->lgh_hdr, LLOG_CHUNK_SIZE);
  95 out:
  96         OBD_FREE_PTR(loghandle);
  97 }
  98
  99 void llog_handle_get(struct llog_handle *loghandle)
 100 {
 101         atomic_inc(&loghandle->lgh_refcount);
 102 }
 103
 104 void llog_handle_put(struct llog_handle *loghandle)
 105 {
 106         LASSERT(atomic_read(&loghandle->lgh_refcount) > 0);
 107         if (atomic_dec_and_test(&loghandle->lgh_refcount))
 108                 llog_free_handle(loghandle);
 109 }
 110
 111 /* returns negative on error; 0 if success; 1 if success & log destroyed */
 112 int llog_cancel_rec(const struct lu_env *env, struct llog_handle *loghandle,
 113                     int index)
 114 {
 115         struct llog_log_hdr *llh = loghandle->lgh_hdr;
 116         int rc = 0;
 117         ENTRY;
 118
 119         CDEBUG(D_RPCTRACE, "Canceling %d in log "DOSTID"\n",
 120                index, POSTID(&loghandle->lgh_id.lgl_oi));
 121
 122         if (index == 0) {
 123                 CERROR("Can't cancel index 0 which is header\n");
 124                 RETURN(-EINVAL);
 125         }
 126
 127         spin_lock(&loghandle->lgh_hdr_lock);
 128         if (!ext2_clear_bit(index, llh->llh_bitmap)) {
 129                 spin_unlock(&loghandle->lgh_hdr_lock);
 130                 CDEBUG(D_RPCTRACE, "Catalog index %u already clear?\n", index);
 131                 RETURN(-ENOENT);
 132         }
 133
 134         llh->llh_count--;
 135
 136         if ((llh->llh_flags & LLOG_F_ZAP_WHEN_EMPTY) &&
 137             (llh->llh_count == 1) &&
 138             (loghandle->lgh_last_idx == (LLOG_BITMAP_BYTES * 8) - 1)) {
 139                 spin_unlock(&loghandle->lgh_hdr_lock);
 140                 rc = llog_destroy(env, loghandle);
 141                 if (rc < 0) {
 142                         CERROR("%s: can't destroy empty llog #"DOSTID
 143                                "#%08x: rc = %d\n",
 144                                loghandle->lgh_ctxt->loc_obd->obd_name,
 145                                POSTID(&loghandle->lgh_id.lgl_oi),
 146                                loghandle->lgh_id.lgl_ogen, rc);
 147                         GOTO(out_err, rc);
 148                 }
 149                 RETURN(LLOG_DEL_PLAIN);
 150         }
 151         spin_unlock(&loghandle->lgh_hdr_lock);
 152
 153         rc = llog_write(env, loghandle, &llh->llh_hdr, NULL, 0, NULL, 0);
 154         if (rc < 0) {
 155                 CERROR("%s: fail to write header for llog #"DOSTID
 156                        "#%08x: rc = %d\n",
 157                        loghandle->lgh_ctxt->loc_obd->obd_name,
 158                        POSTID(&loghandle->lgh_id.lgl_oi),
 159                        loghandle->lgh_id.lgl_ogen, rc);
 160                 GOTO(out_err, rc);
 161         }
 162         RETURN(0);
 163 out_err:
 164         spin_lock(&loghandle->lgh_hdr_lock);
 165         ext2_set_bit(index, llh->llh_bitmap);
 166         llh->llh_count++;
 167         spin_unlock(&loghandle->lgh_hdr_lock);
 168         return rc;
 169 }
 170 EXPORT_SYMBOL(llog_cancel_rec);
 171
 172 static int llog_read_header(const struct lu_env *env,
 173                             struct llog_handle *handle,
 174                             struct obd_uuid *uuid)
 175 {
 176         struct llog_operations *lop;
 177         int rc;
 178
 179         rc = llog_handle2ops(handle, &lop);
 180         if (rc)
 181                 RETURN(rc);
 182
 183         if (lop->lop_read_header == NULL)
 184                 RETURN(-EOPNOTSUPP);
 185
 186         rc = lop->lop_read_header(env, handle);
 187         if (rc == LLOG_EEMPTY) {
 188                 struct llog_log_hdr *llh = handle->lgh_hdr;
 189
 190                 handle->lgh_last_idx = 0; /* header is record with index 0 */
 191                 llh->llh_count = 1;         /* for the header record */
 192                 llh->llh_hdr.lrh_type = LLOG_HDR_MAGIC;
 193                 llh->llh_hdr.lrh_len = llh->llh_tail.lrt_len = LLOG_CHUNK_SIZE;
 194                 llh->llh_hdr.lrh_index = llh->llh_tail.lrt_index = 0;
 195                 llh->llh_timestamp = cfs_time_current_sec();
 196                 if (uuid)
 197                         memcpy(&llh->llh_tgtuuid, uuid,
 198                                sizeof(llh->llh_tgtuuid));
 199                 llh->llh_bitmap_offset = offsetof(typeof(*llh), llh_bitmap);
 200                 ext2_set_bit(0, llh->llh_bitmap);
 201                 rc = 0;
 202         }
 203         return rc;
 204 }
 205
 206 int llog_init_handle(const struct lu_env *env, struct llog_handle *handle,
 207                      int flags, struct obd_uuid *uuid)
 208 {
 209         struct llog_log_hdr     *llh;
 210         int                      rc;
 211
 212         ENTRY;
 213         LASSERT(handle->lgh_hdr == NULL);
 214
 215         OBD_ALLOC_PTR(llh);
 216         if (llh == NULL)
 217                 RETURN(-ENOMEM);
 218         handle->lgh_hdr = llh;
 219         /* first assign flags to use llog_client_ops */
 220         llh->llh_flags = flags;
 221         rc = llog_read_header(env, handle, uuid);
 222         if (rc == 0) {
 223                 if (unlikely((llh->llh_flags & LLOG_F_IS_PLAIN &&
 224                               flags & LLOG_F_IS_CAT) ||
 225                              (llh->llh_flags & LLOG_F_IS_CAT &&
 226                               flags & LLOG_F_IS_PLAIN))) {
 227                         CERROR("%s: llog type is %s but initializing %s\n",
 228                                handle->lgh_ctxt->loc_obd->obd_name,
 229                                llh->llh_flags & LLOG_F_IS_CAT ?
 230                                "catalog" : "plain",
 231                                flags & LLOG_F_IS_CAT ? "catalog" : "plain");
 232                         GOTO(out, rc = -EINVAL);
 233                 } else if (llh->llh_flags &
 234                            (LLOG_F_IS_PLAIN | LLOG_F_IS_CAT)) {
 235                         /*
 236                          * it is possible to open llog without specifying llog
 237                          * type so it is taken from llh_flags
 238                          */
 239                         flags = llh->llh_flags;
 240                 } else {
 241                         /* for some reason the llh_flags has no type set */
 242                         CERROR("llog type is not specified!\n");
 243                         GOTO(out, rc = -EINVAL);
 244                 }
 245                 if (unlikely(uuid &&
 246                              !obd_uuid_equals(uuid, &llh->llh_tgtuuid))) {
 247                         CERROR("%s: llog uuid mismatch: %s/%s\n",
 248                                handle->lgh_ctxt->loc_obd->obd_name,
 249                                (char *)uuid->uuid,
 250                                (char *)llh->llh_tgtuuid.uuid);
 251                         GOTO(out, rc = -EEXIST);
 252                 }
 253         }
 254         if (flags & LLOG_F_IS_CAT) {
 255                 LASSERT(cfs_list_empty(&handle->u.chd.chd_head));
 256                 CFS_INIT_LIST_HEAD(&handle->u.chd.chd_head);
 257                 llh->llh_size = sizeof(struct llog_logid_rec);
 258         } else if (!(flags & LLOG_F_IS_PLAIN)) {
 259                 CERROR("%s: unknown flags: %#x (expected %#x or %#x)\n",
 260                        handle->lgh_ctxt->loc_obd->obd_name,
 261                        flags, LLOG_F_IS_CAT, LLOG_F_IS_PLAIN);
 262                 rc = -EINVAL;
 263         }
 264 out:
 265         if (rc) {
 266                 OBD_FREE_PTR(llh);
 267                 handle->lgh_hdr = NULL;
 268         }
 269         RETURN(rc);
 270 }
 271 EXPORT_SYMBOL(llog_init_handle);
 272
 273 static int llog_process_thread(void *arg)
 274 {
 275         struct llog_process_info        *lpi = arg;
 276         struct llog_handle              *loghandle = lpi->lpi_loghandle;
 277         struct llog_log_hdr             *llh = loghandle->lgh_hdr;
 278         struct llog_process_cat_data    *cd  = lpi->lpi_catdata;
 279         char                            *buf;
 280         __u64                            cur_offset = LLOG_CHUNK_SIZE;
 281         __u64                            last_offset;
 282         int                              rc = 0, index = 1, last_index;
 283         int                              saved_index = 0;
 284         int                              last_called_index = 0;
 285
 286         ENTRY;
 287
 288         LASSERT(llh);
 289
 290         OBD_ALLOC(buf, LLOG_CHUNK_SIZE);
 291         if (!buf) {
 292                 lpi->lpi_rc = -ENOMEM;
 293                 RETURN(0);
 294         }
 295
 296         if (cd != NULL) {
 297                 last_called_index = cd->lpcd_first_idx;
 298                 index = cd->lpcd_first_idx + 1;
 299         }
 300         if (cd != NULL && cd->lpcd_last_idx)
 301                 last_index = cd->lpcd_last_idx;
 302         else
 303                 last_index = LLOG_BITMAP_BYTES * 8 - 1;
 304
 305         while (rc == 0) {
 306                 struct llog_rec_hdr *rec;
 307
 308                 /* skip records not set in bitmap */
 309                 while (index <= last_index &&
 310                        !ext2_test_bit(index, llh->llh_bitmap))
 311                         ++index;
 312
 313                 LASSERT(index <= last_index + 1);
 314                 if (index == last_index + 1)
 315                         break;
 316 repeat:
 317                 CDEBUG(D_OTHER, "index: %d last_index %d\n",
 318                        index, last_index);
 319
 320                 /* get the buf with our target record; avoid old garbage */
 321                 memset(buf, 0, LLOG_CHUNK_SIZE);
 322                 last_offset = cur_offset;
 323                 rc = llog_next_block(lpi->lpi_env, loghandle, &saved_index,
 324                                      index, &cur_offset, buf, LLOG_CHUNK_SIZE);
 325                 if (rc)
 326                         GOTO(out, rc);
 327
 328                 /* NB: when rec->lrh_len is accessed it is already swabbed
 329                  * since it is used at the "end" of the loop and the rec
 330                  * swabbing is done at the beginning of the loop. */
 331                 for (rec = (struct llog_rec_hdr *)buf;
 332                      (char *)rec < buf + LLOG_CHUNK_SIZE;
 333                      rec = (struct llog_rec_hdr *)((char *)rec + rec->lrh_len)){
 334
 335                         CDEBUG(D_OTHER, "processing rec 0x%p type %#x\n",
 336                                rec, rec->lrh_type);
 337
 338                         if (LLOG_REC_HDR_NEEDS_SWABBING(rec))
 339                                 lustre_swab_llog_rec(rec);
 340
 341                         CDEBUG(D_OTHER, "after swabbing, type=%#x idx=%d\n",
 342                                rec->lrh_type, rec->lrh_index);
 343
 344                         if (rec->lrh_index == 0) {
 345                                 /* probably another rec just got added? */
 346                                 if (index <= loghandle->lgh_last_idx)
 347                                         GOTO(repeat, rc = 0);
 348                                 GOTO(out, rc = 0); /* no more records */
 349                         }
 350                         if (rec->lrh_len == 0 ||
 351                             rec->lrh_len > LLOG_CHUNK_SIZE) {
 352                                 CWARN("invalid length %d in llog record for "
 353                                       "index %d/%d\n", rec->lrh_len,
 354                                       rec->lrh_index, index);
 355                                 GOTO(out, rc = -EINVAL);
 356                         }
 357
 358                         if (rec->lrh_index < index) {
 359                                 CDEBUG(D_OTHER, "skipping lrh_index %d\n",
 360                                        rec->lrh_index);
 361                                 continue;
 362                         }
 363
 364                         CDEBUG(D_OTHER,
 365                                "lrh_index: %d lrh_len: %d (%d remains)\n",
 366                                rec->lrh_index, rec->lrh_len,
 367                                (int)(buf + LLOG_CHUNK_SIZE - (char *)rec));
 368
 369                         loghandle->lgh_cur_idx = rec->lrh_index;
 370                         loghandle->lgh_cur_offset = (char *)rec - (char *)buf +
 371                                                     last_offset;
 372
 373                         /* if set, process the callback on this record */
 374                         if (ext2_test_bit(index, llh->llh_bitmap)) {
 375                                 rc = lpi->lpi_cb(lpi->lpi_env, loghandle, rec,
 376                                                  lpi->lpi_cbdata);
 377                                 last_called_index = index;
 378                                 if (rc == LLOG_PROC_BREAK) {
 379                                         GOTO(out, rc);
 380                                 } else if (rc == LLOG_DEL_RECORD) {
 381                                         rc = llog_cancel_rec(lpi->lpi_env,
 382                                                              loghandle,
 383                                                              rec->lrh_index);
 384                                 }
 385                                 if (rc)
 386                                         GOTO(out, rc);
 387                         } else {
 388                                 CDEBUG(D_OTHER, "Skipped index %d\n", index);
 389                         }
 390
 391                         /* next record, still in buffer? */
 392                         ++index;
 393                         if (index > last_index)
 394                                 GOTO(out, rc = 0);
 395                 }
 396         }
 397
 398 out:
 399         if (cd != NULL)
 400                 cd->lpcd_last_idx = last_called_index;
 401
 402         if (unlikely(rc == -EIO)) {
 403                 /* something bad happened to the processing, probably I/O
 404                  * error or the log got corrupted..
 405                  * to be able to finally release the log we discard any
 406                  * remaining bits in the header */
 407                 CERROR("llog found corrupted\n");
 408                 while (index <= last_index) {
 409                         if (ext2_test_bit(index, llh->llh_bitmap) != 0)
 410                                 llog_cancel_rec(lpi->lpi_env, loghandle, index);
 411                         index++;
 412                 }
 413                 rc = 0;
 414         }
 415
 416         OBD_FREE(buf, LLOG_CHUNK_SIZE);
 417         lpi->lpi_rc = rc;
 418         return 0;
 419 }
 420
 421 #ifdef __KERNEL__
 422 static int llog_process_thread_daemonize(void *arg)
 423 {
 424         struct llog_process_info        *lpi = arg;
 425         struct lu_env                    env;
 426         int                              rc;
 427
 428         unshare_fs_struct();
 429
 430         /* client env has no keys, tags is just 0 */
 431         rc = lu_env_init(&env, LCT_LOCAL | LCT_MG_THREAD);
 432         if (rc)
 433                 goto out;
 434         lpi->lpi_env = &env;
 435
 436         rc = llog_process_thread(arg);
 437
 438         lu_env_fini(&env);
 439 out:
 440         complete(&lpi->lpi_completion);
 441         return rc;
 442 }
 443 #endif
 444
 445 int llog_process_or_fork(const struct lu_env *env,
 446                          struct llog_handle *loghandle,
 447                          llog_cb_t cb, void *data, void *catdata, bool fork)
 448 {
 449         struct llog_process_info *lpi;
 450         int                      rc;
 451
 452         ENTRY;
 453
 454         OBD_ALLOC_PTR(lpi);
 455         if (lpi == NULL) {
 456                 CERROR("cannot alloc pointer\n");
 457                 RETURN(-ENOMEM);
 458         }
 459         lpi->lpi_loghandle = loghandle;
 460         lpi->lpi_cb        = cb;
 461         lpi->lpi_cbdata    = data;
 462         lpi->lpi_catdata   = catdata;
 463
 464 #ifdef __KERNEL__
 465         if (fork) {
 466                 struct task_struct *task;
 467
 468                 /* The new thread can't use parent env,
 469                  * init the new one in llog_process_thread_daemonize. */
 470                 lpi->lpi_env = NULL;
 471                 init_completion(&lpi->lpi_completion);
 472                 task = kthread_run(llog_process_thread_daemonize, lpi,
 473                                    "llog_process_thread");
 474                 if (IS_ERR(task)) {
 475                         rc = PTR_ERR(task);
 476                         CERROR("%s: cannot start thread: rc = %d\n",
 477                                loghandle->lgh_ctxt->loc_obd->obd_name, rc);
 478                         GOTO(out_lpi, rc);
 479                 }
 480                 wait_for_completion(&lpi->lpi_completion);
 481         } else {
 482                 lpi->lpi_env = env;
 483                 llog_process_thread(lpi);
 484         }
 485 #else
 486         lpi->lpi_env = env;
 487         llog_process_thread(lpi);
 488 #endif
 489         rc = lpi->lpi_rc;
 490
 491 #ifdef __KERNEL__
 492 out_lpi:
 493 #endif
 494         OBD_FREE_PTR(lpi);
 495         RETURN(rc);
 496 }
 497 EXPORT_SYMBOL(llog_process_or_fork);
 498
 499 int llog_process(const struct lu_env *env, struct llog_handle *loghandle,
 500                  llog_cb_t cb, void *data, void *catdata)
 501 {
 502         int rc;
 503         rc = llog_process_or_fork(env, loghandle, cb, data, catdata, true);
 504         return rc == LLOG_DEL_PLAIN ? 0 : rc;
 505 }
 506 EXPORT_SYMBOL(llog_process);
 507
 508 int llog_reverse_process(const struct lu_env *env,
 509                          struct llog_handle *loghandle, llog_cb_t cb,
 510                          void *data, void *catdata)
 511 {
 512         struct llog_log_hdr *llh = loghandle->lgh_hdr;
 513         struct llog_process_cat_data *cd = catdata;
 514         void *buf;
 515         int rc = 0, first_index = 1, index, idx;
 516         ENTRY;
 517
 518         OBD_ALLOC(buf, LLOG_CHUNK_SIZE);
 519         if (!buf)
 520                 RETURN(-ENOMEM);
 521
 522         if (cd != NULL)
 523                 first_index = cd->lpcd_first_idx + 1;
 524         if (cd != NULL && cd->lpcd_last_idx)
 525                 index = cd->lpcd_last_idx;
 526         else
 527                 index = LLOG_BITMAP_BYTES * 8 - 1;
 528
 529         while (rc == 0) {
 530                 struct llog_rec_hdr *rec;
 531                 struct llog_rec_tail *tail;
 532
 533                 /* skip records not set in bitmap */
 534                 while (index >= first_index &&
 535                        !ext2_test_bit(index, llh->llh_bitmap))
 536                         --index;
 537
 538                 LASSERT(index >= first_index - 1);
 539                 if (index == first_index - 1)
 540                         break;
 541
 542                 /* get the buf with our target record; avoid old garbage */
 543                 memset(buf, 0, LLOG_CHUNK_SIZE);
 544                 rc = llog_prev_block(env, loghandle, index, buf,
 545                                      LLOG_CHUNK_SIZE);
 546                 if (rc)
 547                         GOTO(out, rc);
 548
 549                 rec = buf;
 550                 idx = rec->lrh_index;
 551                 CDEBUG(D_RPCTRACE, "index %u : idx %u\n", index, idx);
 552                 while (idx < index) {
 553                         rec = (void *)rec + rec->lrh_len;
 554                         if (LLOG_REC_HDR_NEEDS_SWABBING(rec))
 555                                 lustre_swab_llog_rec(rec);
 556                         idx ++;
 557                 }
 558                 LASSERT(idx == index);
 559                 tail = (void *)rec + rec->lrh_len - sizeof(*tail);
 560
 561                 /* process records in buffer, starting where we found one */
 562                 while ((void *)tail > buf) {
 563                         if (tail->lrt_index == 0)
 564                                 GOTO(out, rc = 0); /* no more records */
 565
 566                         /* if set, process the callback on this record */
 567                         if (ext2_test_bit(index, llh->llh_bitmap)) {
 568                                 rec = (void *)tail - tail->lrt_len +
 569                                       sizeof(*tail);
 570
 571                                 rc = cb(env, loghandle, rec, data);
 572                                 if (rc == LLOG_PROC_BREAK) {
 573                                         GOTO(out, rc);
 574                                 } else if (rc == LLOG_DEL_RECORD) {
 575                                         rc = llog_cancel_rec(env, loghandle,
 576                                                              tail->lrt_index);
 577                                 }
 578                                 if (rc)
 579                                         GOTO(out, rc);
 580                         }
 581
 582                         /* previous record, still in buffer? */
 583                         --index;
 584                         if (index < first_index)
 585                                 GOTO(out, rc = 0);
 586                         tail = (void *)tail - tail->lrt_len;
 587                 }
 588         }
 589
 590 out:
 591         if (buf)
 592                 OBD_FREE(buf, LLOG_CHUNK_SIZE);
 593         RETURN(rc);
 594 }
 595 EXPORT_SYMBOL(llog_reverse_process);
 596
 597 /**
 598  * new llog API
 599  *
 600  * API functions:
 601  *      llog_open - open llog, may not exist
 602  *      llog_exist - check if llog exists
 603  *      llog_close - close opened llog, pair for open, frees llog_handle
 604  *      llog_declare_create - declare llog creation
 605  *      llog_create - create new llog on disk, need transaction handle
 606  *      llog_declare_write_rec - declaration of llog write
 607  *      llog_write_rec - write llog record on disk, need transaction handle
 608  *      llog_declare_add - declare llog catalog record addition
 609  *      llog_add - add llog record in catalog, need transaction handle
 610  */
 611 int llog_exist(struct llog_handle *loghandle)
 612 {
 613         struct llog_operations  *lop;
 614         int                      rc;
 615
 616         ENTRY;
 617
 618         rc = llog_handle2ops(loghandle, &lop);
 619         if (rc)
 620                 RETURN(rc);
 621         if (lop->lop_exist == NULL)
 622                 RETURN(-EOPNOTSUPP);
 623
 624         rc = lop->lop_exist(loghandle);
 625         RETURN(rc);
 626 }
 627 EXPORT_SYMBOL(llog_exist);
 628
 629 int llog_declare_create(const struct lu_env *env,
 630                         struct llog_handle *loghandle, struct thandle *th)
 631 {
 632         struct llog_operations  *lop;
 633         int                      raised, rc;
 634
 635         ENTRY;
 636
 637         rc = llog_handle2ops(loghandle, &lop);
 638         if (rc)
 639                 RETURN(rc);
 640         if (lop->lop_declare_create == NULL)
 641                 RETURN(-EOPNOTSUPP);
 642
 643         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 644         if (!raised)
 645                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 646         rc = lop->lop_declare_create(env, loghandle, th);
 647         if (!raised)
 648                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 649         RETURN(rc);
 650 }
 651 EXPORT_SYMBOL(llog_declare_create);
 652
 653 int llog_create(const struct lu_env *env, struct llog_handle *handle,
 654                 struct thandle *th)
 655 {
 656         struct llog_operations  *lop;
 657         int                      raised, rc;
 658
 659         ENTRY;
 660
 661         rc = llog_handle2ops(handle, &lop);
 662         if (rc)
 663                 RETURN(rc);
 664         if (lop->lop_create == NULL)
 665                 RETURN(-EOPNOTSUPP);
 666
 667         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 668         if (!raised)
 669                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 670         rc = lop->lop_create(env, handle, th);
 671         if (!raised)
 672                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 673         RETURN(rc);
 674 }
 675 EXPORT_SYMBOL(llog_create);
 676
 677 int llog_declare_write_rec(const struct lu_env *env,
 678                            struct llog_handle *handle,
 679                            struct llog_rec_hdr *rec, int idx,
 680                            struct thandle *th)
 681 {
 682         struct llog_operations  *lop;
 683         int                      raised, rc;
 684
 685         ENTRY;
 686
 687         rc = llog_handle2ops(handle, &lop);
 688         if (rc)
 689                 RETURN(rc);
 690         LASSERT(lop);
 691         if (lop->lop_declare_write_rec == NULL)
 692                 RETURN(-EOPNOTSUPP);
 693
 694         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 695         if (!raised)
 696                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 697         rc = lop->lop_declare_write_rec(env, handle, rec, idx, th);
 698         if (!raised)
 699                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 700         RETURN(rc);
 701 }
 702 EXPORT_SYMBOL(llog_declare_write_rec);
 703
 704 int llog_write_rec(const struct lu_env *env, struct llog_handle *handle,
 705                    struct llog_rec_hdr *rec, struct llog_cookie *logcookies,
 706                    int numcookies, void *buf, int idx, struct thandle *th)
 707 {
 708         struct llog_operations  *lop;
 709         int                      raised, rc, buflen;
 710
 711         ENTRY;
 712
 713         rc = llog_handle2ops(handle, &lop);
 714         if (rc)
 715                 RETURN(rc);
 716
 717         LASSERT(lop);
 718         if (lop->lop_write_rec == NULL)
 719                 RETURN(-EOPNOTSUPP);
 720
 721         if (buf)
 722                 buflen = rec->lrh_len + sizeof(struct llog_rec_hdr) +
 723                          sizeof(struct llog_rec_tail);
 724         else
 725                 buflen = rec->lrh_len;
 726         LASSERT(cfs_size_round(buflen) == buflen);
 727
 728         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 729         if (!raised)
 730                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 731         rc = lop->lop_write_rec(env, handle, rec, logcookies, numcookies,
 732                                 buf, idx, th);
 733         if (!raised)
 734                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 735         RETURN(rc);
 736 }
 737 EXPORT_SYMBOL(llog_write_rec);
 738
 739 int llog_add(const struct lu_env *env, struct llog_handle *lgh,
 740              struct llog_rec_hdr *rec, struct llog_cookie *logcookies,
 741              void *buf, struct thandle *th)
 742 {
 743         int raised, rc;
 744
 745         ENTRY;
 746
 747         if (lgh->lgh_logops->lop_add == NULL)
 748                 RETURN(-EOPNOTSUPP);
 749
 750         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 751         if (!raised)
 752                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 753         rc = lgh->lgh_logops->lop_add(env, lgh, rec, logcookies, buf, th);
 754         if (!raised)
 755                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 756         RETURN(rc);
 757 }
 758 EXPORT_SYMBOL(llog_add);
 759
 760 int llog_declare_add(const struct lu_env *env, struct llog_handle *lgh,
 761                      struct llog_rec_hdr *rec, struct thandle *th)
 762 {
 763         int raised, rc;
 764
 765         ENTRY;
 766
 767         if (lgh->lgh_logops->lop_declare_add == NULL)
 768                 RETURN(-EOPNOTSUPP);
 769
 770         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 771         if (!raised)
 772                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 773         rc = lgh->lgh_logops->lop_declare_add(env, lgh, rec, th);
 774         if (!raised)
 775                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 776         RETURN(rc);
 777 }
 778 EXPORT_SYMBOL(llog_declare_add);
 779
 780 /**
 781  * Helper function to open llog or create it if doesn't exist.
 782  * It hides all transaction handling from caller.
 783  */
 784 int llog_open_create(const struct lu_env *env, struct llog_ctxt *ctxt,
 785                      struct llog_handle **res, struct llog_logid *logid,
 786                      char *name)
 787 {
 788         struct dt_device        *d;
 789         struct thandle          *th;
 790         int                      rc;
 791
 792         ENTRY;
 793
 794         rc = llog_open(env, ctxt, res, logid, name, LLOG_OPEN_NEW);
 795         if (rc)
 796                 RETURN(rc);
 797
 798         if (llog_exist(*res))
 799                 RETURN(0);
 800
 801         LASSERT((*res)->lgh_obj != NULL);
 802
 803         d = lu2dt_dev((*res)->lgh_obj->do_lu.lo_dev);
 804
 805         th = dt_trans_create(env, d);
 806         if (IS_ERR(th))
 807                 GOTO(out, rc = PTR_ERR(th));
 808
 809         rc = llog_declare_create(env, *res, th);
 810         if (rc == 0) {
 811                 rc = dt_trans_start_local(env, d, th);
 812                 if (rc == 0)
 813                         rc = llog_create(env, *res, th);
 814         }
 815         dt_trans_stop(env, d, th);
 816 out:
 817         if (rc)
 818                 llog_close(env, *res);
 819         RETURN(rc);
 820 }
 821 EXPORT_SYMBOL(llog_open_create);
 822
 823 /**
 824  * Helper function to delete existent llog.
 825  */
 826 int llog_erase(const struct lu_env *env, struct llog_ctxt *ctxt,
 827                struct llog_logid *logid, char *name)
 828 {
 829         struct llog_handle      *handle;
 830         int                      rc = 0, rc2;
 831
 832         ENTRY;
 833
 834         /* nothing to erase */
 835         if (name == NULL && logid == NULL)
 836                 RETURN(0);
 837
 838         rc = llog_open(env, ctxt, &handle, logid, name, LLOG_OPEN_EXISTS);
 839         if (rc < 0)
 840                 RETURN(rc);
 841
 842         rc = llog_init_handle(env, handle, LLOG_F_IS_PLAIN, NULL);
 843         if (rc == 0)
 844                 rc = llog_destroy(env, handle);
 845
 846         rc2 = llog_close(env, handle);
 847         if (rc == 0)
 848                 rc = rc2;
 849         RETURN(rc);
 850 }
 851 EXPORT_SYMBOL(llog_erase);
 852
 853 /*
 854  * Helper function for write record in llog.
 855  * It hides all transaction handling from caller.
 856  * Valid only with local llog.
 857  */
 858 int llog_write(const struct lu_env *env, struct llog_handle *loghandle,
 859                struct llog_rec_hdr *rec, struct llog_cookie *reccookie,
 860                int cookiecount, void *buf, int idx)
 861 {
 862         struct dt_device        *dt;
 863         struct thandle          *th;
 864         int                      rc;
 865
 866         ENTRY;
 867
 868         LASSERT(loghandle);
 869         LASSERT(loghandle->lgh_ctxt);
 870         LASSERT(loghandle->lgh_obj != NULL);
 871
 872         dt = lu2dt_dev(loghandle->lgh_obj->do_lu.lo_dev);
 873
 874         th = dt_trans_create(env, dt);
 875         if (IS_ERR(th))
 876                 RETURN(PTR_ERR(th));
 877
 878         rc = llog_declare_write_rec(env, loghandle, rec, idx, th);
 879         if (rc)
 880                 GOTO(out_trans, rc);
 881
 882         rc = dt_trans_start_local(env, dt, th);
 883         if (rc)
 884                 GOTO(out_trans, rc);
 885
 886         down_write(&loghandle->lgh_lock);
 887         rc = llog_write_rec(env, loghandle, rec, reccookie,
 888                             cookiecount, buf, idx, th);
 889         up_write(&loghandle->lgh_lock);
 890 out_trans:
 891         dt_trans_stop(env, dt, th);
 892         RETURN(rc);
 893 }
 894 EXPORT_SYMBOL(llog_write);
 895
 896 int llog_open(const struct lu_env *env, struct llog_ctxt *ctxt,
 897               struct llog_handle **lgh, struct llog_logid *logid,
 898               char *name, enum llog_open_param open_param)
 899 {
 900         int      raised;
 901         int      rc;
 902
 903         ENTRY;
 904
 905         LASSERT(ctxt);
 906         LASSERT(ctxt->loc_logops);
 907
 908         if (ctxt->loc_logops->lop_open == NULL) {
 909                 *lgh = NULL;
 910                 RETURN(-EOPNOTSUPP);
 911         }
 912
 913         *lgh = llog_alloc_handle();
 914         if (*lgh == NULL)
 915                 RETURN(-ENOMEM);
 916         (*lgh)->lgh_ctxt = ctxt;
 917         (*lgh)->lgh_logops = ctxt->loc_logops;
 918
 919         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 920         if (!raised)
 921                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 922         rc = ctxt->loc_logops->lop_open(env, *lgh, logid, name, open_param);
 923         if (!raised)
 924                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 925         if (rc) {
 926                 llog_free_handle(*lgh);
 927                 *lgh = NULL;
 928         }
 929         RETURN(rc);
 930 }
 931 EXPORT_SYMBOL(llog_open);
 932
 933 int llog_close(const struct lu_env *env, struct llog_handle *loghandle)
 934 {
 935         struct llog_operations  *lop;
 936         int                      rc;
 937
 938         ENTRY;
 939
 940         rc = llog_handle2ops(loghandle, &lop);
 941         if (rc)
 942                 GOTO(out, rc);
 943         if (lop->lop_close == NULL)
 944                 GOTO(out, rc = -EOPNOTSUPP);
 945         rc = lop->lop_close(env, loghandle);
 946 out:
 947         llog_handle_put(loghandle);
 948         RETURN(rc);
 949 }
 950 EXPORT_SYMBOL(llog_close);
 951
 952 int llog_is_empty(const struct lu_env *env, struct llog_ctxt *ctxt,
 953                   char *name)
 954 {
 955         struct llog_handle      *llh;
 956         int                      rc = 0;
 957
 958         rc = llog_open(env, ctxt, &llh, NULL, name, LLOG_OPEN_EXISTS);
 959         if (rc < 0) {
 960                 if (likely(rc == -ENOENT))
 961                         rc = 0;
 962                 GOTO(out, rc);
 963         }
 964
 965         rc = llog_init_handle(env, llh, LLOG_F_IS_PLAIN, NULL);
 966         if (rc)
 967                 GOTO(out_close, rc);
 968         rc = llog_get_size(llh);
 969
 970 out_close:
 971         llog_close(env, llh);
 972 out:
 973         /* header is record 1 */
 974         return (rc <= 1);
 975 }
 976 EXPORT_SYMBOL(llog_is_empty);
 977
 978 int llog_copy_handler(const struct lu_env *env, struct llog_handle *llh,
 979                       struct llog_rec_hdr *rec, void *data)
 980 {
 981         struct llog_handle      *copy_llh = data;
 982
 983         /* Append all records */
 984         return llog_write(env, copy_llh, rec, NULL, 0, NULL, -1);
 985 }
 986 EXPORT_SYMBOL(llog_copy_handler);
 987
 988 /* backup plain llog */
 989 int llog_backup(const struct lu_env *env, struct obd_device *obd,
 990                 struct llog_ctxt *ctxt, struct llog_ctxt *bctxt,
 991                 char *name, char *backup)
 992 {
 993         struct llog_handle      *llh, *bllh;
 994         int                      rc;
 995
 996         ENTRY;
 997
 998         /* open original log */
 999         rc = llog_open(env, ctxt, &llh, NULL, name, LLOG_OPEN_EXISTS);
1000         if (rc < 0) {
1001                 /* the -ENOENT case is also reported to the caller
1002                  * but silently so it should handle that if needed.
1003                  */
1004                 if (rc != -ENOENT)
1005                         CERROR("%s: failed to open log %s: rc = %d\n",
1006                                obd->obd_name, name, rc);
1007                 RETURN(rc);
1008         }
1009
1010         rc = llog_init_handle(env, llh, LLOG_F_IS_PLAIN, NULL);
1011         if (rc)
1012                 GOTO(out_close, rc);
1013
1014         /* Make sure there's no old backup log */
1015         rc = llog_erase(env, bctxt, NULL, backup);
1016         if (rc < 0 && rc != -ENOENT)
1017                 GOTO(out_close, rc);
1018
1019         /* open backup log */
1020         rc = llog_open_create(env, bctxt, &bllh, NULL, backup);
1021         if (rc) {
1022                 CERROR("%s: failed to open backup logfile %s: rc = %d\n",
1023                        obd->obd_name, backup, rc);
1024                 GOTO(out_close, rc);
1025         }
1026
1027         /* check that backup llog is not the same object as original one */
1028         if (llh->lgh_obj == bllh->lgh_obj) {
1029                 CERROR("%s: backup llog %s to itself (%s), objects %p/%p\n",
1030                        obd->obd_name, name, backup, llh->lgh_obj,
1031                        bllh->lgh_obj);
1032                 GOTO(out_backup, rc = -EEXIST);
1033         }
1034
1035         rc = llog_init_handle(env, bllh, LLOG_F_IS_PLAIN, NULL);
1036         if (rc)
1037                 GOTO(out_backup, rc);
1038
1039         /* Copy log record by record */
1040         rc = llog_process_or_fork(env, llh, llog_copy_handler, (void *)bllh,
1041                                   NULL, false);
1042         if (rc)
1043                 CERROR("%s: failed to backup log %s: rc = %d\n",
1044                        obd->obd_name, name, rc);
1045 out_backup:
1046         llog_close(env, bllh);
1047 out_close:
1048         llog_close(env, llh);
1049         RETURN(rc);
1050 }
1051 EXPORT_SYMBOL(llog_backup);