lustre/obdclass/llog.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2012, 2017, Intel Corporation.
  27  */
  28 /*
  29  * This file is part of Lustre, http://www.lustre.org/
  30  *
  31  * lustre/obdclass/llog.c
  32  *
  33  * OST<->MDS recovery logging infrastructure.
  34  * Invariants in implementation:
  35  * - we do not share logs among different OST<->MDS connections, so that
  36  *   if an OST or MDS fails it need only look at log(s) relevant to itself
  37  *
  38  * Author: Andreas Dilger <adilger@clusterfs.com>
  39  * Author: Alex Zhuravlev <bzzz@whamcloud.com>
  40  * Author: Mikhail Pershin <tappro@whamcloud.com>
  41  */
  42
  43 #define DEBUG_SUBSYSTEM S_LOG
  44
  45 #include <linux/pid_namespace.h>
  46 #include <linux/kthread.h>
  47 #include <llog_swab.h>
  48 #include <lustre_log.h>
  49 #include <obd_support.h>
  50 #include <obd_class.h>
  51 #include "llog_internal.h"
  52
  53 /*
  54  * Allocate a new log or catalog handle
  55  * Used inside llog_open().
  56  */
  57 static struct llog_handle *llog_alloc_handle(void)
  58 {
  59         struct llog_handle *loghandle;
  60
  61         OBD_ALLOC_PTR(loghandle);
  62         if (loghandle == NULL)
  63                 return NULL;
  64
  65         init_rwsem(&loghandle->lgh_lock);
  66         mutex_init(&loghandle->lgh_hdr_mutex);
  67         init_rwsem(&loghandle->lgh_last_sem);
  68         INIT_LIST_HEAD(&loghandle->u.phd.phd_entry);
  69         refcount_set(&loghandle->lgh_refcount, 1);
  70
  71         return loghandle;
  72 }
  73
  74 /*
  75  * Free llog handle and header data if exists. Used in llog_close() only
  76  */
  77 static void llog_free_handle(struct llog_handle *loghandle)
  78 {
  79         LASSERT(loghandle != NULL);
  80
  81         /* failed llog_init_handle */
  82         if (loghandle->lgh_hdr == NULL)
  83                 goto out;
  84
  85         if (loghandle->lgh_hdr->llh_flags & LLOG_F_IS_PLAIN)
  86                 LASSERT(list_empty(&loghandle->u.phd.phd_entry));
  87         else if (loghandle->lgh_hdr->llh_flags & LLOG_F_IS_CAT)
  88                 LASSERT(list_empty(&loghandle->u.chd.chd_head));
  89         OBD_FREE_LARGE(loghandle->lgh_hdr, loghandle->lgh_hdr_size);
  90 out:
  91         OBD_FREE_PTR(loghandle);
  92 }
  93
  94 struct llog_handle *llog_handle_get(struct llog_handle *loghandle)
  95 {
  96         if (refcount_inc_not_zero(&loghandle->lgh_refcount))
  97                 return loghandle;
  98         return NULL;
  99 }
 100
 101 int llog_handle_put(const struct lu_env *env, struct llog_handle *loghandle)
 102 {
 103         int rc = 0;
 104
 105         if (refcount_dec_and_test(&loghandle->lgh_refcount)) {
 106                 const struct llog_operations *lop;
 107
 108                 rc = llog_handle2ops(loghandle, &lop);
 109                 if (!rc) {
 110                         if (lop->lop_close)
 111                                 rc = lop->lop_close(env, loghandle);
 112                         else
 113                                 rc = -EOPNOTSUPP;
 114                 }
 115                 llog_free_handle(loghandle);
 116         }
 117         return rc;
 118 }
 119
 120 static int llog_declare_destroy(const struct lu_env *env,
 121                                 struct llog_handle *handle,
 122                                 struct thandle *th)
 123 {
 124         const struct llog_operations *lop;
 125         int rc;
 126
 127         ENTRY;
 128
 129         rc = llog_handle2ops(handle, &lop);
 130         if (rc)
 131                 RETURN(rc);
 132         if (lop->lop_declare_destroy == NULL)
 133                 RETURN(-EOPNOTSUPP);
 134
 135         rc = lop->lop_declare_destroy(env, handle, th);
 136
 137         RETURN(rc);
 138 }
 139
 140 int llog_trans_destroy(const struct lu_env *env, struct llog_handle *handle,
 141                        struct thandle *th)
 142 {
 143         const struct llog_operations *lop;
 144         int rc;
 145         ENTRY;
 146
 147         rc = llog_handle2ops(handle, &lop);
 148         if (rc < 0)
 149                 RETURN(rc);
 150         if (lop->lop_destroy == NULL)
 151                 RETURN(-EOPNOTSUPP);
 152
 153         LASSERT(handle->lgh_obj != NULL);
 154         if (!llog_exist(handle))
 155                 RETURN(0);
 156
 157         rc = lop->lop_destroy(env, handle, th);
 158
 159         RETURN(rc);
 160 }
 161
 162 int llog_destroy(const struct lu_env *env, struct llog_handle *handle)
 163 {
 164         const struct llog_operations *lop;
 165         struct dt_device *dt;
 166         struct thandle *th;
 167         int rc;
 168
 169         ENTRY;
 170
 171         rc = llog_handle2ops(handle, &lop);
 172         if (rc < 0)
 173                 RETURN(rc);
 174         if (lop->lop_destroy == NULL)
 175                 RETURN(-EOPNOTSUPP);
 176
 177         if (handle->lgh_obj == NULL) {
 178                 /* if lgh_obj == NULL, then it is from client side destroy */
 179                 rc = lop->lop_destroy(env, handle, NULL);
 180                 RETURN(rc);
 181         }
 182
 183         if (!llog_exist(handle))
 184                 RETURN(0);
 185
 186         dt = lu2dt_dev(handle->lgh_obj->do_lu.lo_dev);
 187
 188         if (unlikely(unlikely(dt->dd_rdonly)))
 189                 RETURN(-EROFS);
 190
 191         th = dt_trans_create(env, dt);
 192         if (IS_ERR(th))
 193                 RETURN(PTR_ERR(th));
 194
 195         rc = llog_declare_destroy(env, handle, th);
 196         if (rc != 0)
 197                 GOTO(out_trans, rc);
 198
 199         rc = dt_trans_start_local(env, dt, th);
 200         if (rc < 0)
 201                 GOTO(out_trans, rc);
 202
 203         rc = lop->lop_destroy(env, handle, th);
 204
 205 out_trans:
 206         dt_trans_stop(env, dt, th);
 207
 208         RETURN(rc);
 209 }
 210 EXPORT_SYMBOL(llog_destroy);
 211
 212 /* returns negative on error; 0 if success; 1 if success & log destroyed */
 213 int llog_cancel_arr_rec(const struct lu_env *env, struct llog_handle *loghandle,
 214                         int num, int *index)
 215 {
 216         struct llog_thread_info *lgi = llog_info(env);
 217         struct dt_device        *dt;
 218         struct llog_log_hdr     *llh;
 219         struct thandle          *th;
 220         __u32                    tmp_lgc_index;
 221         int                      rc, i = 0;
 222         int rc1;
 223         bool subtract_count = false;
 224
 225         ENTRY;
 226
 227         LASSERT(loghandle != NULL);
 228         LASSERT(loghandle->lgh_ctxt != NULL);
 229         LASSERT(loghandle->lgh_obj != NULL);
 230
 231         llh = loghandle->lgh_hdr;
 232
 233         CDEBUG(D_RPCTRACE, "Canceling %d records, first %d in log "DFID"\n",
 234                num, index[0], PFID(&loghandle->lgh_id.lgl_oi.oi_fid));
 235
 236         dt = lu2dt_dev(loghandle->lgh_obj->do_lu.lo_dev);
 237
 238         if (unlikely(unlikely(dt->dd_rdonly)))
 239                 RETURN(0);
 240
 241         th = dt_trans_create(env, dt);
 242         if (IS_ERR(th))
 243                 RETURN(PTR_ERR(th));
 244
 245         rc = llog_declare_write_rec(env, loghandle, &llh->llh_hdr, 0, th);
 246         if (rc < 0)
 247                 GOTO(out_trans, rc);
 248
 249         if ((llh->llh_flags & LLOG_F_ZAP_WHEN_EMPTY)) {
 250                 rc = llog_declare_destroy(env, loghandle, th);
 251                 if (rc < 0)
 252                         GOTO(out_trans, rc);
 253         }
 254
 255         th->th_wait_submit = 1;
 256         rc = dt_trans_start_local(env, dt, th);
 257         if (rc < 0)
 258                 GOTO(out_trans, rc);
 259
 260         down_write(&loghandle->lgh_lock);
 261         /* clear bitmap */
 262         mutex_lock(&loghandle->lgh_hdr_mutex);
 263         for (i = 0; i < num; ++i) {
 264                 if (index[i] == 0) {
 265                         CERROR("Can't cancel index 0 which is header\n");
 266                         GOTO(out_unlock, rc = -EINVAL);
 267                 }
 268                 if (!__test_and_clear_bit_le(index[i], LLOG_HDR_BITMAP(llh))) {
 269                         CDEBUG(D_RPCTRACE, "Catalog index %u already clear?\n",
 270                                index[i]);
 271                         GOTO(out_unlock, rc = -ENOENT);
 272                 }
 273         }
 274         loghandle->lgh_hdr->llh_count -= num;
 275         subtract_count = true;
 276
 277         /* Since llog_process_thread use lgi_cookie, it`s better to save them
 278          * and restore after using
 279          */
 280         tmp_lgc_index = lgi->lgi_cookie.lgc_index;
 281         /* Pass this index to llog_osd_write_rec(), which will use the index
 282          * to only update the necesary bitmap. */
 283         lgi->lgi_cookie.lgc_index = index[0];
 284         /* update header */
 285         rc = llog_write_rec(env, loghandle, &llh->llh_hdr, (num != 1 ? NULL :
 286                             &lgi->lgi_cookie), LLOG_HEADER_IDX, th);
 287         lgi->lgi_cookie.lgc_index = tmp_lgc_index;
 288
 289         if (rc != 0)
 290                 GOTO(out_unlock, rc);
 291
 292         if ((llh->llh_flags & LLOG_F_ZAP_WHEN_EMPTY) &&
 293             (llh->llh_count == 1) &&
 294             ((loghandle->lgh_last_idx == LLOG_HDR_BITMAP_SIZE(llh) - 1) ||
 295              (loghandle->u.phd.phd_cat_handle != NULL &&
 296               loghandle->u.phd.phd_cat_handle->u.chd.chd_current_log !=
 297                 loghandle))) {
 298                 /* never try to destroy it again */
 299                 llh->llh_flags &= ~LLOG_F_ZAP_WHEN_EMPTY;
 300                 rc = llog_trans_destroy(env, loghandle, th);
 301                 if (rc < 0) {
 302                         /* Sigh, can not destroy the final plain llog, but
 303                          * the bitmap has been clearly, so the record can not
 304                          * be accessed anymore, let's return 0 for now, and
 305                          * the orphan will be handled by LFSCK. */
 306                         CERROR("%s: can't destroy empty llog "DFID": rc = %d\n",
 307                                loghandle2name(loghandle),
 308                                PFID(&loghandle->lgh_id.lgl_oi.oi_fid), rc);
 309                         GOTO(out_unlock, rc = 0);
 310                 }
 311                 rc = LLOG_DEL_PLAIN;
 312         }
 313
 314 out_unlock:
 315         if (rc < 0) {
 316                 /* restore bitmap while holding a mutex */
 317                 if (subtract_count) {
 318                         loghandle->lgh_hdr->llh_count += num;
 319                         subtract_count = false;
 320                 }
 321                 for (i = i - 1; i >= 0; i--)
 322                         set_bit_le(index[i], LLOG_HDR_BITMAP(llh));
 323         }
 324         mutex_unlock(&loghandle->lgh_hdr_mutex);
 325         up_write(&loghandle->lgh_lock);
 326 out_trans:
 327         rc1 = dt_trans_stop(env, dt, th);
 328         if (rc == 0)
 329                 rc = rc1;
 330         if (rc1 < 0) {
 331                 mutex_lock(&loghandle->lgh_hdr_mutex);
 332                 if (subtract_count)
 333                         loghandle->lgh_hdr->llh_count += num;
 334                 for (i = i - 1; i >= 0; i--)
 335                         set_bit_le(index[i], LLOG_HDR_BITMAP(llh));
 336                 mutex_unlock(&loghandle->lgh_hdr_mutex);
 337         }
 338         RETURN(rc);
 339 }
 340
 341 int llog_cancel_rec(const struct lu_env *env, struct llog_handle *loghandle,
 342                     int index)
 343 {
 344         return llog_cancel_arr_rec(env, loghandle, 1, &index);
 345 }
 346
 347 int llog_read_header(const struct lu_env *env, struct llog_handle *handle,
 348                      const struct obd_uuid *uuid)
 349 {
 350         const struct llog_operations *lop;
 351         int rc;
 352         ENTRY;
 353
 354         rc = llog_handle2ops(handle, &lop);
 355         if (rc)
 356                 RETURN(rc);
 357
 358         if (lop->lop_read_header == NULL)
 359                 RETURN(-EOPNOTSUPP);
 360
 361         rc = lop->lop_read_header(env, handle);
 362         if (rc == LLOG_EEMPTY) {
 363                 struct llog_log_hdr *llh = handle->lgh_hdr;
 364
 365                 /* lrh_len should be initialized in llog_init_handle */
 366                 handle->lgh_last_idx = 0; /* header is record with index 0 */
 367                 llh->llh_count = 1;         /* for the header record */
 368                 llh->llh_hdr.lrh_type = LLOG_HDR_MAGIC;
 369                 LASSERT(handle->lgh_ctxt->loc_chunk_size >=
 370                                                 LLOG_MIN_CHUNK_SIZE);
 371                 llh->llh_hdr.lrh_len = handle->lgh_ctxt->loc_chunk_size;
 372                 llh->llh_hdr.lrh_index = 0;
 373                 llh->llh_timestamp = ktime_get_real_seconds();
 374                 if (uuid)
 375                         memcpy(&llh->llh_tgtuuid, uuid,
 376                                sizeof(llh->llh_tgtuuid));
 377                 llh->llh_bitmap_offset = offsetof(typeof(*llh), llh_bitmap);
 378                 /* Since update llog header might also call this function,
 379                  * let's reset the bitmap to 0 here */
 380                 memset(LLOG_HDR_BITMAP(llh), 0, llh->llh_hdr.lrh_len -
 381                                                 llh->llh_bitmap_offset -
 382                                                 sizeof(llh->llh_tail));
 383                 set_bit_le(0, LLOG_HDR_BITMAP(llh));
 384                 LLOG_HDR_TAIL(llh)->lrt_len = llh->llh_hdr.lrh_len;
 385                 LLOG_HDR_TAIL(llh)->lrt_index = llh->llh_hdr.lrh_index;
 386                 rc = 0;
 387         }
 388         RETURN(rc);
 389 }
 390 EXPORT_SYMBOL(llog_read_header);
 391
 392 int llog_init_handle(const struct lu_env *env, struct llog_handle *handle,
 393                      int flags, struct obd_uuid *uuid)
 394 {
 395         struct llog_log_hdr     *llh;
 396         enum llog_flag           fmt = flags & LLOG_F_EXT_MASK;
 397         int                      rc;
 398         int                     chunk_size = handle->lgh_ctxt->loc_chunk_size;
 399         ENTRY;
 400
 401         LASSERT(handle->lgh_hdr == NULL);
 402
 403         LASSERT(chunk_size >= LLOG_MIN_CHUNK_SIZE);
 404         OBD_ALLOC_LARGE(llh, chunk_size);
 405         if (llh == NULL)
 406                 RETURN(-ENOMEM);
 407
 408         handle->lgh_hdr = llh;
 409         handle->lgh_hdr_size = chunk_size;
 410         /* first assign flags to use llog_client_ops */
 411         llh->llh_flags = flags;
 412         rc = llog_read_header(env, handle, uuid);
 413         if (rc == 0) {
 414                 if (unlikely((llh->llh_flags & LLOG_F_IS_PLAIN &&
 415                               flags & LLOG_F_IS_CAT) ||
 416                              (llh->llh_flags & LLOG_F_IS_CAT &&
 417                               flags & LLOG_F_IS_PLAIN))) {
 418                         CERROR("%s: llog type is %s but initializing %s\n",
 419                                loghandle2name(handle),
 420                                llh->llh_flags & LLOG_F_IS_CAT ?
 421                                "catalog" : "plain",
 422                                flags & LLOG_F_IS_CAT ? "catalog" : "plain");
 423                         GOTO(out, rc = -EINVAL);
 424                 } else if (llh->llh_flags &
 425                            (LLOG_F_IS_PLAIN | LLOG_F_IS_CAT)) {
 426                         /*
 427                          * it is possible to open llog without specifying llog
 428                          * type so it is taken from llh_flags
 429                          */
 430                         flags = llh->llh_flags;
 431                 } else {
 432                         /* for some reason the llh_flags has no type set */
 433                         CERROR("llog type is not specified!\n");
 434                         GOTO(out, rc = -EINVAL);
 435                 }
 436                 if (unlikely(uuid &&
 437                              !obd_uuid_equals(uuid, &llh->llh_tgtuuid))) {
 438                         CERROR("%s: llog uuid mismatch: %s/%s\n",
 439                                loghandle2name(handle),
 440                                (char *)uuid->uuid,
 441                                (char *)llh->llh_tgtuuid.uuid);
 442                         GOTO(out, rc = -EEXIST);
 443                 }
 444         }
 445         if (flags & LLOG_F_IS_CAT) {
 446                 LASSERT(list_empty(&handle->u.chd.chd_head));
 447                 INIT_LIST_HEAD(&handle->u.chd.chd_head);
 448                 llh->llh_size = sizeof(struct llog_logid_rec);
 449                 llh->llh_flags |= LLOG_F_IS_FIXSIZE;
 450         } else if (!(flags & LLOG_F_IS_PLAIN)) {
 451                 CERROR("%s: unknown flags: %#x (expected %#x or %#x)\n",
 452                        loghandle2name(handle), flags, LLOG_F_IS_CAT,
 453                        LLOG_F_IS_PLAIN);
 454                 rc = -EINVAL;
 455         }
 456         llh->llh_flags |= fmt;
 457 out:
 458         if (rc) {
 459                 OBD_FREE_LARGE(llh, chunk_size);
 460                 handle->lgh_hdr = NULL;
 461         }
 462         RETURN(rc);
 463 }
 464 EXPORT_SYMBOL(llog_init_handle);
 465
 466 int llog_verify_record(const struct llog_handle *llh, struct llog_rec_hdr *rec)
 467 {
 468         int chunk_size = llh->lgh_hdr->llh_hdr.lrh_len;
 469
 470         if (rec->lrh_len == 0 || rec->lrh_len > chunk_size) {
 471                 CERROR("%s: record is too large: %d > %d\n",
 472                        loghandle2name(llh), rec->lrh_len, chunk_size);
 473                 return -EINVAL;
 474         }
 475         if (rec->lrh_index >= LLOG_HDR_BITMAP_SIZE(llh->lgh_hdr)) {
 476                 CERROR("%s: index is too high: %d\n",
 477                        loghandle2name(llh), rec->lrh_index);
 478                 return -EINVAL;
 479         }
 480         if ((rec->lrh_type & LLOG_OP_MASK) != LLOG_OP_MAGIC) {
 481                 CERROR("%s: magic %x is bad\n",
 482                        loghandle2name(llh), rec->lrh_type);
 483                 return -EINVAL;
 484         }
 485
 486         return 0;
 487 }
 488 EXPORT_SYMBOL(llog_verify_record);
 489
 490 static inline bool llog_is_index_skipable(int idx, struct llog_log_hdr *llh,
 491                                           struct llog_process_cat_data *cd)
 492 {
 493         if (cd && (cd->lpcd_read_mode & LLOG_READ_MODE_RAW))
 494                 return false;
 495
 496         return !test_bit_le(idx, LLOG_HDR_BITMAP(llh));
 497 }
 498
 499 static int llog_process_thread(void *arg)
 500 {
 501         struct llog_process_info        *lpi = arg;
 502         struct llog_handle              *loghandle = lpi->lpi_loghandle;
 503         struct llog_log_hdr             *llh = loghandle->lgh_hdr;
 504         struct llog_process_cat_data    *cd  = lpi->lpi_catdata;
 505         struct llog_thread_info         *lti;
 506         char                            *buf;
 507         size_t                           chunk_size;
 508         __u64                            cur_offset;
 509         int                              rc = 0, index = 1, last_index;
 510         int                              saved_index = 0;
 511         int                              last_called_index = 0;
 512         bool                             repeated = false;
 513         bool                            refresh_idx = false;
 514
 515         ENTRY;
 516
 517         if (llh == NULL)
 518                 RETURN(-EINVAL);
 519
 520         lti = lpi->lpi_env == NULL ? NULL : llog_info(lpi->lpi_env);
 521
 522         cur_offset = chunk_size = llh->llh_hdr.lrh_len;
 523         /* expect chunk_size to be power of two */
 524         LASSERT(is_power_of_2(chunk_size));
 525
 526         OBD_ALLOC_LARGE(buf, chunk_size);
 527         if (buf == NULL) {
 528                 lpi->lpi_rc = -ENOMEM;
 529                 RETURN(0);
 530         }
 531
 532         if (cd != NULL) {
 533                 last_called_index = cd->lpcd_first_idx;
 534                 index = cd->lpcd_first_idx + 1;
 535         }
 536         if (cd && cd->lpcd_last_idx)
 537                 last_index = cd->lpcd_last_idx;
 538         else if (cd && (cd->lpcd_read_mode & LLOG_READ_MODE_RAW))
 539                 last_index = loghandle->lgh_last_idx;
 540         else
 541                 last_index = LLOG_HDR_BITMAP_SIZE(llh) - 1;
 542
 543         while (rc == 0) {
 544                 struct llog_rec_hdr *rec;
 545                 off_t chunk_offset = 0;
 546                 unsigned int buf_offset = 0;
 547                 int     lh_last_idx;
 548                 int     synced_idx = 0;
 549
 550                 /* skip records not set in bitmap */
 551                 while (index <= last_index &&
 552                        llog_is_index_skipable(index, llh, cd))
 553                         ++index;
 554
 555                 /* There are no indices prior the last_index */
 556                 if (index > last_index)
 557                         break;
 558
 559                 CDEBUG(D_OTHER, "index: %d last_index %d\n", index,
 560                        last_index);
 561
 562 repeat:
 563                 /* get the buf with our target record; avoid old garbage */
 564                 memset(buf, 0, chunk_size);
 565                 /* the record index for outdated chunk data */
 566                 /* it is safe to process buffer until saved lgh_last_idx */
 567                 lh_last_idx = LLOG_HDR_TAIL(llh)->lrt_index;
 568                 rc = llog_next_block(lpi->lpi_env, loghandle, &saved_index,
 569                                      index, &cur_offset, buf, chunk_size);
 570                 if (repeated && rc)
 571                         CDEBUG(D_OTHER, "cur_offset %llu, chunk_offset %llu,"
 572                                " buf_offset %u, rc = %d\n", cur_offset,
 573                                (__u64)chunk_offset, buf_offset, rc);
 574                 if (rc == -ESTALE)
 575                         GOTO(out, rc = 0);
 576                 /* we`ve tried to reread the chunk, but there is no
 577                  * new records */
 578                 if (rc == -EIO && repeated && (chunk_offset + buf_offset) ==
 579                     cur_offset)
 580                         GOTO(out, rc = 0);
 581                 if (rc != 0)
 582                         GOTO(out, rc);
 583
 584                 /* NB: after llog_next_block() call the cur_offset is the
 585                  * offset of the next block after read one.
 586                  * The absolute offset of the current chunk is calculated
 587                  * from cur_offset value and stored in chunk_offset variable.
 588                  */
 589                 if ((cur_offset & (chunk_size - 1)) != 0)
 590                         chunk_offset = cur_offset & ~(chunk_size - 1);
 591                 else
 592                         chunk_offset = cur_offset - chunk_size;
 593
 594                 /* NB: when rec->lrh_len is accessed it is already swabbed
 595                  * since it is used at the "end" of the loop and the rec
 596                  * swabbing is done at the beginning of the loop. */
 597                 for (rec = (struct llog_rec_hdr *)(buf + buf_offset);
 598                      (char *)rec < buf + chunk_size;
 599                      rec = llog_rec_hdr_next(rec)) {
 600
 601                         CDEBUG(D_OTHER, "processing rec 0x%p type %#x\n",
 602                                rec, rec->lrh_type);
 603
 604                         if (LLOG_REC_HDR_NEEDS_SWABBING(rec))
 605                                 lustre_swab_llog_rec(rec);
 606
 607                         CDEBUG(D_OTHER, "after swabbing, type=%#x idx=%d\n",
 608                                rec->lrh_type, rec->lrh_index);
 609
 610                         if (index == (synced_idx + 1) &&
 611                             synced_idx == LLOG_HDR_TAIL(llh)->lrt_index)
 612                                 GOTO(out, rc = 0);
 613
 614                         if (OBD_FAIL_PRECHECK(OBD_FAIL_LLOG_PROCESS_TIMEOUT) &&
 615                                 cfs_fail_val == (unsigned int)
 616                                         (loghandle->lgh_id.lgl_oi.oi.oi_id &
 617                                          0xFFFFFFFF)) {
 618                                 OBD_RACE(OBD_FAIL_LLOG_PROCESS_TIMEOUT);
 619                         }
 620
 621                         /* the bitmap could be changed during processing
 622                          * records from the chunk. For wrapped catalog
 623                          * it means we can read deleted record and try to
 624                          * process it. Check this case and reread the chunk.
 625                          * It is safe to process to lh_last_idx, including
 626                          * lh_last_idx if it was synced. We can not do <=
 627                          * comparison, cause for wrapped catalog lgh_last_idx
 628                          * could be less than index. So we detect last index
 629                          * for processing as index == lh_last_idx+1. But when
 630                          * catalog is wrapped and full lgh_last_idx=llh_cat_idx,
 631                          * the first processing index is llh_cat_idx+1.The
 632                          * exception is !(lgh_last_idx == llh_cat_idx &&
 633                          * index == llh_cat_idx + 1), and after simplification
 634                          * it turns to
 635                          * lh_last_idx != LLOG_HDR_TAIL(llh)->lrt_index
 636                          * This exception is working for catalog only.
 637                          */
 638
 639                         if ((index == lh_last_idx && synced_idx != index) ||
 640                             (index == (lh_last_idx + 1) &&
 641                              lh_last_idx != LLOG_HDR_TAIL(llh)->lrt_index) ||
 642                             (rec->lrh_index == 0 && !repeated)) {
 643
 644                                 /* save offset inside buffer for the re-read */
 645                                 buf_offset = (char *)rec - (char *)buf;
 646                                 cur_offset = chunk_offset;
 647                                 repeated = true;
 648                                 /* We need to be sure lgh_last_idx
 649                                  * record was saved to disk
 650                                  */
 651                                 down_read(&loghandle->lgh_last_sem);
 652                                 synced_idx = LLOG_HDR_TAIL(llh)->lrt_index;
 653                                 up_read(&loghandle->lgh_last_sem);
 654                                 CDEBUG(D_OTHER, "synced_idx: %d\n", synced_idx);
 655                                 goto repeat;
 656
 657                         }
 658
 659                         repeated = false;
 660
 661                         rc = llog_verify_record(loghandle, rec);
 662                         if (rc) {
 663                                 CERROR("%s: invalid record in llog "DFID
 664                                        " record for index %d/%d: rc = %d\n",
 665                                        loghandle2name(loghandle),
 666                                        PFID(&loghandle->lgh_id.lgl_oi.oi_fid),
 667                                        rec->lrh_index, index, rc);
 668                                 /*
 669                                  * the block seem to be corrupted, let's try
 670                                  * with the next one. reset rc to go to the
 671                                  * next chunk.
 672                                  */
 673                                 refresh_idx = true;
 674                                 index = 0;
 675                                 GOTO(repeat, rc = 0);
 676                         }
 677
 678                         if (rec->lrh_index < index) {
 679                                 CDEBUG(D_OTHER, "skipping lrh_index %d\n",
 680                                        rec->lrh_index);
 681                                 continue;
 682                         }
 683
 684                         if (rec->lrh_index > index) {
 685                                 /* the record itself looks good, but we met a
 686                                  * gap which can be result of old bugs, just
 687                                  * keep going */
 688                                 CERROR("%s: "DFID" index %u, expected %u\n",
 689                                        loghandle2name(loghandle),
 690                                        PFID(&loghandle->lgh_id.lgl_oi.oi_fid),
 691                                        rec->lrh_index, index);
 692                                 index = rec->lrh_index;
 693                         }
 694
 695                         CDEBUG(D_OTHER,
 696                                "lrh_index: %d lrh_len: %d (%d remains)\n",
 697                                rec->lrh_index, rec->lrh_len,
 698                                (int)(buf + chunk_size - (char *)rec));
 699
 700                         /* lgh_cur_offset is used only at llog_test_3 */
 701                         loghandle->lgh_cur_offset = (char *)rec - (char *)buf +
 702                                                     chunk_offset;
 703
 704                         /* if needed, process the callback on this record */
 705                         if (!llog_is_index_skipable(index, llh, cd)) {
 706                                 struct llog_cookie *lgc;
 707                                 __u64   tmp_off;
 708                                 int     tmp_idx;
 709
 710                                 CDEBUG((llh->llh_flags & LLOG_F_IS_CAT ?
 711                                         D_HA : D_OTHER),
 712                                        "index: %d, lh_last_idx: %d "
 713                                        "synced_idx: %d lgh_last_idx: %d\n",
 714                                        index, lh_last_idx, synced_idx,
 715                                        loghandle->lgh_last_idx);
 716
 717                                 if (lti != NULL) {
 718                                         lgc = &lti->lgi_cookie;
 719                                         /* store lu_env for recursive calls */
 720                                         tmp_off = lgc->lgc_offset;
 721                                         tmp_idx = lgc->lgc_index;
 722
 723                                         lgc->lgc_offset = (char *)rec -
 724                                                 (char *)buf + chunk_offset;
 725                                         lgc->lgc_index = rec->lrh_index;
 726                                 }
 727                                 /* using lu_env for passing record offset to
 728                                  * llog_write through various callbacks */
 729                                 rc = lpi->lpi_cb(lpi->lpi_env, loghandle, rec,
 730                                                  lpi->lpi_cbdata);
 731                                 last_called_index = index;
 732
 733                                 if (lti != NULL) {
 734                                         lgc->lgc_offset = tmp_off;
 735                                         lgc->lgc_index = tmp_idx;
 736                                 }
 737
 738                                 if (rc == LLOG_PROC_BREAK ||
 739                                     rc == LLOG_SKIP_PLAIN) {
 740                                         GOTO(out, rc);
 741                                 } else if (rc == LLOG_DEL_RECORD) {
 742                                         rc = llog_cancel_rec(lpi->lpi_env,
 743                                                              loghandle,
 744                                                              rec->lrh_index);
 745                                         /* Allow parallel cancelling, ENOENT
 746                                          * means record was canceled at another
 747                                          * processing thread or callback
 748                                          */
 749                                         if (rc == -ENOENT)
 750                                                 rc = 0;
 751                                 }
 752                                 if (rc)
 753                                         GOTO(out, rc);
 754                                 /* some stupid callbacks directly cancel records
 755                                  * and delete llog. Check it and stop
 756                                  * processing. */
 757                                 if (loghandle->lgh_hdr == NULL ||
 758                                     loghandle->lgh_hdr->llh_count == 1)
 759                                         GOTO(out, rc = 0);
 760                         }
 761                         /* exit if the last index is reached */
 762                         if (index >= last_index)
 763                                 GOTO(out, rc = 0);
 764                         ++index;
 765                 }
 766         }
 767
 768 out:
 769         CDEBUG(D_HA, "stop processing %s "DOSTID":%x index %d count %d\n",
 770                ((llh->llh_flags & LLOG_F_IS_CAT) ? "catalog" : "plain"),
 771                POSTID(&loghandle->lgh_id.lgl_oi), loghandle->lgh_id.lgl_ogen,
 772                index, llh->llh_count);
 773
 774         if (cd != NULL)
 775                 cd->lpcd_last_idx = last_called_index;
 776
 777         if (unlikely(rc == -EIO && loghandle->lgh_obj != NULL)) {
 778                 if (dt_object_remote(loghandle->lgh_obj)) {
 779                         /* If it is remote object, then -EIO might means
 780                          * disconnection or eviction, let's return -EAGAIN,
 781                          * so for update recovery log processing, it will
 782                          * retry until the umount or abort recovery, see
 783                          * lod_sub_recovery_thread() */
 784                         CERROR("%s retry remote llog process\n",
 785                                loghandle2name(loghandle));
 786                         rc = -EAGAIN;
 787                 } else {
 788                         /* something bad happened to the processing of a local
 789                          * llog file, probably I/O error or the log got
 790                          * corrupted to be able to finally release the log we
 791                          * discard any remaining bits in the header */
 792                         CERROR("%s: Local llog found corrupted #"DOSTID":%x"
 793                                " %s index %d count %d\n",
 794                                loghandle2name(loghandle),
 795                                POSTID(&loghandle->lgh_id.lgl_oi),
 796                                loghandle->lgh_id.lgl_ogen,
 797                                ((llh->llh_flags & LLOG_F_IS_CAT) ? "catalog" :
 798                                 "plain"), index, llh->llh_count);
 799
 800                         while (index <= last_index) {
 801                                 if (test_bit_le(index,
 802                                                   LLOG_HDR_BITMAP(llh)) != 0)
 803                                         llog_cancel_rec(lpi->lpi_env, loghandle,
 804                                                         index);
 805                                 index++;
 806                         }
 807                         rc = 0;
 808                 }
 809         }
 810
 811         OBD_FREE_LARGE(buf, chunk_size);
 812         lpi->lpi_rc = rc;
 813         return 0;
 814 }
 815
 816 static int llog_process_thread_daemonize(void *arg)
 817 {
 818         struct llog_process_info        *lpi = arg;
 819         struct lu_env                    env;
 820         int                              rc;
 821         struct nsproxy                  *new_ns, *curr_ns = current->nsproxy;
 822
 823         task_lock(lpi->lpi_reftask);
 824         new_ns = lpi->lpi_reftask->nsproxy;
 825         if (curr_ns != new_ns) {
 826                 get_nsproxy(new_ns);
 827
 828                 current->nsproxy = new_ns;
 829                 /* XXX: we should call put_nsproxy() instead of
 830                  * atomic_dec(&ns->count) directly. But put_nsproxy() cannot be
 831                  * used outside of the kernel itself, because it calls
 832                  * free_nsproxy() which is not exported by the kernel
 833                  * (defined in kernel/nsproxy.c) */
 834                 if (curr_ns)
 835                         atomic_dec(&curr_ns->count);
 836         }
 837         task_unlock(lpi->lpi_reftask);
 838
 839         /* client env has no keys, tags is just 0 */
 840         rc = lu_env_init(&env, LCT_LOCAL | LCT_MG_THREAD);
 841         if (rc)
 842                 goto out;
 843         lpi->lpi_env = &env;
 844
 845         rc = llog_process_thread(arg);
 846
 847         lu_env_fini(&env);
 848 out:
 849         complete(&lpi->lpi_completion);
 850         return rc;
 851 }
 852
 853 int llog_process_or_fork(const struct lu_env *env,
 854                          struct llog_handle *loghandle,
 855                          llog_cb_t cb, void *data, void *catdata, bool fork)
 856 {
 857         struct llog_process_info *lpi;
 858         struct llog_process_data *d = data;
 859         struct llog_process_cat_data *cd = catdata;
 860         __u32 flags = loghandle->lgh_hdr->llh_flags;
 861         int rc;
 862
 863         ENTRY;
 864
 865         OBD_ALLOC_PTR(lpi);
 866         if (lpi == NULL) {
 867                 CERROR("cannot alloc pointer\n");
 868                 RETURN(-ENOMEM);
 869         }
 870         lpi->lpi_loghandle = loghandle;
 871         lpi->lpi_cb        = cb;
 872         lpi->lpi_cbdata    = data;
 873         lpi->lpi_catdata   = catdata;
 874
 875         CDEBUG(D_OTHER, "Processing "DFID" flags 0x%03x startcat %d startidx %d first_idx %d last_idx %d read_mode %d\n",
 876                PFID(&loghandle->lgh_id.lgl_oi.oi_fid), flags,
 877                (flags & LLOG_F_IS_CAT) && d ? d->lpd_startcat : -1,
 878                (flags & LLOG_F_IS_CAT) && d ? d->lpd_startidx : -1,
 879                cd ? cd->lpcd_first_idx : -1, cd ? cd->lpcd_last_idx : -1,
 880                cd ? cd->lpcd_read_mode : -1);
 881         if (fork) {
 882                 struct task_struct *task;
 883
 884                 /* The new thread can't use parent env,
 885                  * init the new one in llog_process_thread_daemonize. */
 886                 lpi->lpi_env = NULL;
 887                 init_completion(&lpi->lpi_completion);
 888                 /* take reference to current, so that
 889                  * llog_process_thread_daemonize() can use it to switch to
 890                  * namespace associated with current  */
 891                 lpi->lpi_reftask = current;
 892                 task = kthread_run(llog_process_thread_daemonize, lpi,
 893                                    "llog_process_thread");
 894                 if (IS_ERR(task)) {
 895                         rc = PTR_ERR(task);
 896                         CERROR("%s: cannot start thread: rc = %d\n",
 897                                loghandle2name(loghandle), rc);
 898                         GOTO(out_lpi, rc);
 899                 }
 900                 wait_for_completion(&lpi->lpi_completion);
 901         } else {
 902                 lpi->lpi_env = env;
 903                 llog_process_thread(lpi);
 904         }
 905         rc = lpi->lpi_rc;
 906
 907 out_lpi:
 908         OBD_FREE_PTR(lpi);
 909         RETURN(rc);
 910 }
 911 EXPORT_SYMBOL(llog_process_or_fork);
 912
 913 int llog_process(const struct lu_env *env, struct llog_handle *loghandle,
 914                  llog_cb_t cb, void *data, void *catdata)
 915 {
 916         int rc;
 917         rc = llog_process_or_fork(env, loghandle, cb, data, catdata, true);
 918         return rc == LLOG_DEL_PLAIN ? 0 : rc;
 919 }
 920 EXPORT_SYMBOL(llog_process);
 921
 922 static inline const struct cred *llog_raise_resource(void)
 923 {
 924         struct cred *cred = NULL;
 925
 926         if (cap_raised(current_cap(), CAP_SYS_RESOURCE))
 927                 return cred;
 928
 929         cred = prepare_creds();
 930         if (!cred)
 931                 return cred;
 932
 933         cap_raise(cred->cap_effective, CAP_SYS_RESOURCE);
 934         return override_creds(cred);
 935 }
 936
 937 static inline void llog_restore_resource(const struct cred *old_cred)
 938 {
 939         if (old_cred)
 940                 revert_creds(old_cred);
 941 }
 942
 943 int llog_reverse_process(const struct lu_env *env,
 944                          struct llog_handle *loghandle, llog_cb_t cb,
 945                          void *data, void *catdata)
 946 {
 947         struct llog_log_hdr *llh = loghandle->lgh_hdr;
 948         struct llog_process_cat_data *cd = catdata;
 949         void *buf;
 950         int rc = 0, first_index = 1, index, idx;
 951         __u32   chunk_size = llh->llh_hdr.lrh_len;
 952         ENTRY;
 953
 954         OBD_ALLOC_LARGE(buf, chunk_size);
 955         if (buf == NULL)
 956                 RETURN(-ENOMEM);
 957
 958         if (cd != NULL)
 959                 first_index = cd->lpcd_first_idx + 1;
 960         if (cd != NULL && cd->lpcd_last_idx)
 961                 index = cd->lpcd_last_idx;
 962         else
 963                 index = LLOG_HDR_BITMAP_SIZE(llh) - 1;
 964
 965         while (rc == 0) {
 966                 struct llog_rec_hdr *rec;
 967                 struct llog_rec_tail *tail;
 968
 969                 /* skip records not set in bitmap */
 970                 while (index >= first_index &&
 971                        llog_is_index_skipable(index, llh, cd))
 972                         --index;
 973
 974                 LASSERT(index >= first_index - 1);
 975                 if (index == first_index - 1)
 976                         break;
 977
 978                 /* get the buf with our target record; avoid old garbage */
 979                 memset(buf, 0, chunk_size);
 980                 rc = llog_prev_block(env, loghandle, index, buf, chunk_size);
 981                 if (rc)
 982                         GOTO(out, rc);
 983
 984                 rec = buf;
 985                 idx = rec->lrh_index;
 986                 CDEBUG(D_RPCTRACE, "index %u : idx %u\n", index, idx);
 987                 while (idx < index) {
 988                         rec = (void *)rec + rec->lrh_len;
 989                         if (LLOG_REC_HDR_NEEDS_SWABBING(rec))
 990                                 lustre_swab_llog_rec(rec);
 991                         idx ++;
 992                 }
 993                 LASSERT(idx == index);
 994                 tail = (void *)rec + rec->lrh_len - sizeof(*tail);
 995
 996                 /* process records in buffer, starting where we found one */
 997                 while ((void *)tail > buf) {
 998                         if (tail->lrt_index == 0)
 999                                 GOTO(out, rc = 0); /* no more records */
1000
1001                         /* if needed, process the callback on this record */
1002                         if (!llog_is_index_skipable(index, llh, cd)) {
1003                                 rec = (void *)tail - tail->lrt_len +
1004                                       sizeof(*tail);
1005
1006                                 rc = cb(env, loghandle, rec, data);
1007                                 if (rc == LLOG_PROC_BREAK ||
1008                                     rc == LLOG_SKIP_PLAIN) {
1009                                         GOTO(out, rc);
1010                                 } else if (rc == LLOG_DEL_RECORD) {
1011                                         rc = llog_cancel_rec(env, loghandle,
1012                                                              tail->lrt_index);
1013                                 }
1014                                 if (rc)
1015                                         GOTO(out, rc);
1016                         }
1017
1018                         /* previous record, still in buffer? */
1019                         --index;
1020                         if (index < first_index)
1021                                 GOTO(out, rc = 0);
1022                         tail = (void *)tail - tail->lrt_len;
1023                 }
1024         }
1025
1026 out:
1027         if (buf != NULL)
1028                 OBD_FREE_LARGE(buf, chunk_size);
1029         RETURN(rc);
1030 }
1031 EXPORT_SYMBOL(llog_reverse_process);
1032
1033 /**
1034  * new llog API
1035  *
1036  * API functions:
1037  *      llog_open - open llog, may not exist
1038  *      llog_exist - check if llog exists
1039  *      llog_close - close opened llog, pair for open, frees llog_handle
1040  *      llog_declare_create - declare llog creation
1041  *      llog_create - create new llog on disk, need transaction handle
1042  *      llog_declare_write_rec - declaration of llog write
1043  *      llog_write_rec - write llog record on disk, need transaction handle
1044  *      llog_declare_add - declare llog catalog record addition
1045  *      llog_add - add llog record in catalog, need transaction handle
1046  */
1047 int llog_exist(struct llog_handle *loghandle)
1048 {
1049         const struct llog_operations *lop;
1050         int rc;
1051
1052         ENTRY;
1053
1054         rc = llog_handle2ops(loghandle, &lop);
1055         if (rc)
1056                 RETURN(rc);
1057         if (lop->lop_exist == NULL)
1058                 RETURN(-EOPNOTSUPP);
1059
1060         rc = lop->lop_exist(loghandle);
1061         RETURN(rc);
1062 }
1063 EXPORT_SYMBOL(llog_exist);
1064
1065 int llog_declare_create(const struct lu_env *env,
1066                         struct llog_handle *loghandle, struct thandle *th)
1067 {
1068         const struct cred *old_cred;
1069         const struct llog_operations *lop;
1070         int rc;
1071
1072         ENTRY;
1073
1074         rc = llog_handle2ops(loghandle, &lop);
1075         if (rc)
1076                 RETURN(rc);
1077         if (lop->lop_declare_create == NULL)
1078                 RETURN(-EOPNOTSUPP);
1079
1080         old_cred = llog_raise_resource();
1081         rc = lop->lop_declare_create(env, loghandle, th);
1082         llog_restore_resource(old_cred);
1083         RETURN(rc);
1084 }
1085
1086 int llog_create(const struct lu_env *env, struct llog_handle *handle,
1087                 struct thandle *th)
1088 {
1089         const struct cred *old_cred;
1090         const struct llog_operations *lop;
1091         int rc;
1092
1093         ENTRY;
1094
1095         rc = llog_handle2ops(handle, &lop);
1096         if (rc)
1097                 RETURN(rc);
1098         if (lop->lop_create == NULL)
1099                 RETURN(-EOPNOTSUPP);
1100
1101         old_cred = llog_raise_resource();
1102         rc = lop->lop_create(env, handle, th);
1103         llog_restore_resource(old_cred);
1104         RETURN(rc);
1105 }
1106
1107 int llog_declare_write_rec(const struct lu_env *env,
1108                            struct llog_handle *handle,
1109                            struct llog_rec_hdr *rec, int idx,
1110                            struct thandle *th)
1111 {
1112         const struct cred *old_cred;
1113         const struct llog_operations *lop;
1114         int rc;
1115
1116         ENTRY;
1117
1118         rc = llog_handle2ops(handle, &lop);
1119         if (rc)
1120                 RETURN(rc);
1121         LASSERT(lop);
1122         if (lop->lop_declare_write_rec == NULL)
1123                 RETURN(-EOPNOTSUPP);
1124
1125         old_cred = llog_raise_resource();
1126         rc = lop->lop_declare_write_rec(env, handle, rec, idx, th);
1127         llog_restore_resource(old_cred);
1128         RETURN(rc);
1129 }
1130
1131 int llog_write_rec(const struct lu_env *env, struct llog_handle *handle,
1132                    struct llog_rec_hdr *rec, struct llog_cookie *logcookies,
1133                    int idx, struct thandle *th)
1134 {
1135         const struct cred *old_cred;
1136         const struct llog_operations *lop;
1137         int rc, buflen;
1138
1139         ENTRY;
1140
1141         /* API sanity checks */
1142         if (handle == NULL) {
1143                 CERROR("loghandle is missed\n");
1144                 RETURN(-EPROTO);
1145         } else if (handle->lgh_obj == NULL) {
1146                 CERROR("loghandle %p with NULL object\n",
1147                         handle);
1148                 RETURN(-EPROTO);
1149         } else if (th == NULL) {
1150                 CERROR("%s: missed transaction handle\n",
1151                        loghandle2name(handle));
1152                 RETURN(-EPROTO);
1153         } else if (handle->lgh_hdr == NULL) {
1154                 CERROR("%s: loghandle %p with no header\n",
1155                        loghandle2name(handle), handle);
1156                 RETURN(-EPROTO);
1157         }
1158
1159         rc = llog_handle2ops(handle, &lop);
1160         if (rc)
1161                 RETURN(rc);
1162
1163         if (lop->lop_write_rec == NULL)
1164                 RETURN(-EOPNOTSUPP);
1165
1166         buflen = rec->lrh_len;
1167         LASSERT(cfs_size_round(buflen) == buflen);
1168
1169         old_cred = llog_raise_resource();
1170         rc = lop->lop_write_rec(env, handle, rec, logcookies, idx, th);
1171         llog_restore_resource(old_cred);
1172         RETURN(rc);
1173 }
1174
1175 int llog_add(const struct lu_env *env, struct llog_handle *lgh,
1176              struct llog_rec_hdr *rec, struct llog_cookie *logcookies,
1177              struct thandle *th)
1178 {
1179         const struct cred *old_cred;
1180         int rc;
1181
1182         ENTRY;
1183
1184         if (lgh->lgh_logops->lop_add == NULL)
1185                 RETURN(-EOPNOTSUPP);
1186
1187         old_cred = llog_raise_resource();
1188         rc = lgh->lgh_logops->lop_add(env, lgh, rec, logcookies, th);
1189         llog_restore_resource(old_cred);
1190         RETURN(rc);
1191 }
1192 EXPORT_SYMBOL(llog_add);
1193
1194 int llog_declare_add(const struct lu_env *env, struct llog_handle *lgh,
1195                      struct llog_rec_hdr *rec, struct thandle *th)
1196 {
1197         const struct cred *old_cred;
1198         int rc;
1199
1200         ENTRY;
1201
1202         if (lgh->lgh_logops->lop_declare_add == NULL)
1203                 RETURN(-EOPNOTSUPP);
1204
1205         old_cred = llog_raise_resource();
1206         rc = lgh->lgh_logops->lop_declare_add(env, lgh, rec, th);
1207         llog_restore_resource(old_cred);
1208         RETURN(rc);
1209 }
1210 EXPORT_SYMBOL(llog_declare_add);
1211
1212 /**
1213  * Helper function to open llog or create it if doesn't exist.
1214  * It hides all transaction handling from caller.
1215  */
1216 int llog_open_create(const struct lu_env *env, struct llog_ctxt *ctxt,
1217                      struct llog_handle **res, struct llog_logid *logid,
1218                      char *name)
1219 {
1220         struct dt_device        *d;
1221         struct thandle          *th;
1222         int                      rc;
1223
1224         ENTRY;
1225
1226         rc = llog_open(env, ctxt, res, logid, name, LLOG_OPEN_NEW);
1227         if (rc)
1228                 RETURN(rc);
1229
1230         if (llog_exist(*res))
1231                 RETURN(0);
1232
1233         LASSERT((*res)->lgh_obj != NULL);
1234
1235         d = lu2dt_dev((*res)->lgh_obj->do_lu.lo_dev);
1236
1237         if (unlikely(unlikely(d->dd_rdonly)))
1238                 RETURN(-EROFS);
1239
1240         th = dt_trans_create(env, d);
1241         if (IS_ERR(th))
1242                 GOTO(out, rc = PTR_ERR(th));
1243
1244         /* Create update llog object synchronously, which
1245          * happens during inialization process see
1246          * lod_sub_prep_llog(), to make sure the update
1247          * llog object is created before corss-MDT writing
1248          * updates into the llog object */
1249         if (ctxt->loc_flags & LLOG_CTXT_FLAG_NORMAL_FID)
1250                 th->th_sync = 1;
1251
1252         th->th_wait_submit = 1;
1253         rc = llog_declare_create(env, *res, th);
1254         if (rc == 0) {
1255                 rc = dt_trans_start_local(env, d, th);
1256                 if (rc == 0)
1257                         rc = llog_create(env, *res, th);
1258         }
1259         dt_trans_stop(env, d, th);
1260 out:
1261         if (rc)
1262                 llog_close(env, *res);
1263         RETURN(rc);
1264 }
1265 EXPORT_SYMBOL(llog_open_create);
1266
1267 /**
1268  * Helper function to delete existent llog.
1269  */
1270 int llog_erase(const struct lu_env *env, struct llog_ctxt *ctxt,
1271                struct llog_logid *logid, char *name)
1272 {
1273         struct llog_handle      *handle;
1274         int                      rc = 0, rc2;
1275
1276         ENTRY;
1277
1278         /* nothing to erase */
1279         if (name == NULL && logid == NULL)
1280                 RETURN(0);
1281
1282         rc = llog_open(env, ctxt, &handle, logid, name, LLOG_OPEN_EXISTS);
1283         if (rc < 0)
1284                 RETURN(rc);
1285
1286         rc = llog_init_handle(env, handle, LLOG_F_IS_PLAIN, NULL);
1287         if (rc == 0)
1288                 rc = llog_destroy(env, handle);
1289
1290         rc2 = llog_close(env, handle);
1291         if (rc == 0)
1292                 rc = rc2;
1293         RETURN(rc);
1294 }
1295 EXPORT_SYMBOL(llog_erase);
1296
1297 /*
1298  * Helper function for write record in llog.
1299  * It hides all transaction handling from caller.
1300  * Valid only with local llog.
1301  */
1302 int llog_write(const struct lu_env *env, struct llog_handle *loghandle,
1303                struct llog_rec_hdr *rec, int idx)
1304 {
1305         struct dt_device        *dt;
1306         struct thandle          *th;
1307         bool                    need_cookie;
1308         int                     rc;
1309
1310         ENTRY;
1311
1312         LASSERT(loghandle);
1313         LASSERT(loghandle->lgh_ctxt);
1314         LASSERT(loghandle->lgh_obj != NULL);
1315
1316         dt = lu2dt_dev(loghandle->lgh_obj->do_lu.lo_dev);
1317
1318         if (unlikely(unlikely(dt->dd_rdonly)))
1319                 RETURN(-EROFS);
1320
1321         th = dt_trans_create(env, dt);
1322         if (IS_ERR(th))
1323                 RETURN(PTR_ERR(th));
1324
1325         rc = llog_declare_write_rec(env, loghandle, rec, idx, th);
1326         if (rc)
1327                 GOTO(out_trans, rc);
1328
1329         th->th_wait_submit = 1;
1330         rc = dt_trans_start_local(env, dt, th);
1331         if (rc)
1332                 GOTO(out_trans, rc);
1333
1334         need_cookie = !(idx == LLOG_HEADER_IDX || idx == LLOG_NEXT_IDX);
1335
1336         down_write(&loghandle->lgh_lock);
1337         if (need_cookie) {
1338                 struct llog_thread_info *lti = llog_info(env);
1339
1340                 /* cookie comes from llog_process_thread */
1341                 rc = llog_write_rec(env, loghandle, rec, &lti->lgi_cookie,
1342                                     rec->lrh_index, th);
1343                 /* upper layer didn`t pass cookie so change rc */
1344                 rc = (rc == 1 ? 0 : rc);
1345         } else {
1346                 rc = llog_write_rec(env, loghandle, rec, NULL, idx, th);
1347         }
1348
1349         up_write(&loghandle->lgh_lock);
1350 out_trans:
1351         dt_trans_stop(env, dt, th);
1352         RETURN(rc);
1353 }
1354 EXPORT_SYMBOL(llog_write);
1355
1356 int llog_open(const struct lu_env *env, struct llog_ctxt *ctxt,
1357               struct llog_handle **lgh, struct llog_logid *logid,
1358               char *name, enum llog_open_param open_param)
1359 {
1360         const struct cred *old_cred;
1361         int      rc;
1362
1363         ENTRY;
1364
1365         LASSERT(ctxt);
1366         LASSERT(ctxt->loc_logops);
1367
1368         if (ctxt->loc_logops->lop_open == NULL) {
1369                 *lgh = NULL;
1370                 RETURN(-EOPNOTSUPP);
1371         }
1372
1373         *lgh = llog_alloc_handle();
1374         if (*lgh == NULL)
1375                 RETURN(-ENOMEM);
1376         (*lgh)->lgh_ctxt = ctxt;
1377         (*lgh)->lgh_logops = ctxt->loc_logops;
1378
1379         old_cred = llog_raise_resource();
1380         rc = ctxt->loc_logops->lop_open(env, *lgh, logid, name, open_param);
1381         llog_restore_resource(old_cred);
1382         if (rc) {
1383                 llog_free_handle(*lgh);
1384                 *lgh = NULL;
1385         }
1386         RETURN(rc);
1387 }
1388 EXPORT_SYMBOL(llog_open);
1389
1390 int llog_close(const struct lu_env *env, struct llog_handle *loghandle)
1391 {
1392         return llog_handle_put(env, loghandle);
1393 }
1394 EXPORT_SYMBOL(llog_close);
1395
1396 /**
1397  * Helper function to get the llog size in records. It is used by MGS
1398  * mostly to check that config llog exists and contains data.
1399  *
1400  * \param[in] env       execution environment
1401  * \param[in] ctxt      llog context
1402  * \param[in] name      llog name
1403  *
1404  * \retval              true if there are records in llog besides a header
1405  * \retval              false on error or llog without records
1406  */
1407 int llog_is_empty(const struct lu_env *env, struct llog_ctxt *ctxt,
1408                   char *name)
1409 {
1410         struct llog_handle      *llh;
1411         int                      rc = 0;
1412
1413         rc = llog_open(env, ctxt, &llh, NULL, name, LLOG_OPEN_EXISTS);
1414         if (rc < 0) {
1415                 if (likely(rc == -ENOENT))
1416                         rc = 0;
1417                 GOTO(out, rc);
1418         }
1419
1420         rc = llog_init_handle(env, llh, LLOG_F_IS_PLAIN, NULL);
1421         if (rc)
1422                 GOTO(out_close, rc);
1423         rc = llog_get_size(llh);
1424
1425 out_close:
1426         llog_close(env, llh);
1427 out:
1428         /* The header is record 1, the llog is still considered as empty
1429          * if there is only header */
1430         return (rc <= 1);
1431 }
1432 EXPORT_SYMBOL(llog_is_empty);
1433
1434 /* this callback run in raw read mode (canceled record are processed) */
1435 int llog_copy_handler(const struct lu_env *env, struct llog_handle *llh,
1436                       struct llog_rec_hdr *rec, void *data)
1437 {
1438         struct llog_handle *copy_llh = data;
1439         int idx = rec->lrh_index;
1440         int rc;
1441
1442         ENTRY;
1443
1444         /* Append all records */
1445         rc = llog_write(env, copy_llh, rec, LLOG_NEXT_IDX);
1446
1447         /* Cancel the record if it is canceled on the source */
1448         if (!rc && !test_bit_le(idx, LLOG_HDR_BITMAP(llh->lgh_hdr)))
1449                 rc = llog_cancel_rec(env, copy_llh, copy_llh->lgh_last_idx);
1450
1451         RETURN(rc);
1452 }
1453
1454 /* backup plain llog */
1455 int llog_backup(const struct lu_env *env, struct obd_device *obd,
1456                 struct llog_ctxt *ctxt, struct llog_ctxt *bctxt,
1457                 char *name, char *backup)
1458 {
1459         struct llog_handle *llh, *bllh;
1460         struct llog_process_cat_data cd = {0};
1461         int rc;
1462
1463         ENTRY;
1464
1465         /* open original log */
1466         rc = llog_open(env, ctxt, &llh, NULL, name, LLOG_OPEN_EXISTS);
1467         if (rc < 0) {
1468                 /* the -ENOENT case is also reported to the caller
1469                  * but silently so it should handle that if needed.
1470                  */
1471                 if (rc != -ENOENT)
1472                         CERROR("%s: failed to open log %s: rc = %d\n",
1473                                obd->obd_name, name, rc);
1474                 RETURN(rc);
1475         }
1476
1477         rc = llog_init_handle(env, llh, LLOG_F_IS_PLAIN, NULL);
1478         if (rc)
1479                 GOTO(out_close, rc);
1480
1481         /* Make sure there's no old backup log */
1482         rc = llog_erase(env, bctxt, NULL, backup);
1483         if (rc < 0 && rc != -ENOENT)
1484                 GOTO(out_close, rc);
1485
1486         /* open backup log */
1487         rc = llog_open_create(env, bctxt, &bllh, NULL, backup);
1488         if (rc) {
1489                 CERROR("%s: failed to open backup logfile %s: rc = %d\n",
1490                        obd->obd_name, backup, rc);
1491                 GOTO(out_close, rc);
1492         }
1493
1494         /* check that backup llog is not the same object as original one */
1495         if (llh->lgh_obj == bllh->lgh_obj) {
1496                 CERROR("%s: backup llog %s to itself (%s), objects %p/%p\n",
1497                        obd->obd_name, name, backup, llh->lgh_obj,
1498                        bllh->lgh_obj);
1499                 GOTO(out_backup, rc = -EEXIST);
1500         }
1501
1502         rc = llog_init_handle(env, bllh, LLOG_F_IS_PLAIN, NULL);
1503         if (rc)
1504                 GOTO(out_backup, rc);
1505
1506         /* Read canceled records to have an exact copy */
1507         cd.lpcd_read_mode = LLOG_READ_MODE_RAW;
1508         /* Copy log record by record */
1509         rc = llog_process_or_fork(env, llh, llog_copy_handler, (void *)bllh,
1510                                   &cd, false);
1511         if (rc)
1512                 CERROR("%s: failed to backup log %s: rc = %d\n",
1513                        obd->obd_name, name, rc);
1514 out_backup:
1515         llog_close(env, bllh);
1516 out_close:
1517         llog_close(env, llh);
1518         RETURN(rc);
1519 }
1520 EXPORT_SYMBOL(llog_backup);
1521
1522 /* Get size of llog */
1523 __u64 llog_size(const struct lu_env *env, struct llog_handle *llh)
1524 {
1525         int rc;
1526         struct lu_attr la;
1527
1528         rc = llh->lgh_obj->do_ops->do_attr_get(env, llh->lgh_obj, &la);
1529         if (rc) {
1530                 CERROR("%s: attr_get failed for "DFID": rc = %d\n",
1531                        loghandle2name(llh), PFID(&llh->lgh_id.lgl_oi.oi_fid),
1532                        rc);
1533                 return 0;
1534         }
1535
1536         return la.la_size;
1537 }
1538 EXPORT_SYMBOL(llog_size);
1539