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/fs_struct.h>
  46 #include <linux/pid_namespace.h>
  47 #include <linux/kthread.h>
  48 #include <llog_swab.h>
  49 #include <lustre_log.h>
  50 #include <obd_support.h>
  51 #include <obd_class.h>
  52 #include "llog_internal.h"
  53
  54 /*
  55  * Allocate a new log or catalog handle
  56  * Used inside llog_open().
  57  */
  58 static struct llog_handle *llog_alloc_handle(void)
  59 {
  60         struct llog_handle *loghandle;
  61
  62         OBD_ALLOC_PTR(loghandle);
  63         if (loghandle == NULL)
  64                 return NULL;
  65
  66         init_rwsem(&loghandle->lgh_lock);
  67         mutex_init(&loghandle->lgh_hdr_mutex);
  68         init_rwsem(&loghandle->lgh_last_sem);
  69         INIT_LIST_HEAD(&loghandle->u.phd.phd_entry);
  70         refcount_set(&loghandle->lgh_refcount, 1);
  71
  72         return loghandle;
  73 }
  74
  75 /*
  76  * Free llog handle and header data if exists. Used in llog_close() only
  77  */
  78 static void llog_free_handle(struct llog_handle *loghandle)
  79 {
  80         LASSERT(loghandle != NULL);
  81
  82         /* failed llog_init_handle */
  83         if (loghandle->lgh_hdr == NULL)
  84                 goto out;
  85
  86         if (loghandle->lgh_hdr->llh_flags & LLOG_F_IS_PLAIN)
  87                 LASSERT(list_empty(&loghandle->u.phd.phd_entry));
  88         else if (loghandle->lgh_hdr->llh_flags & LLOG_F_IS_CAT)
  89                 LASSERT(list_empty(&loghandle->u.chd.chd_head));
  90         OBD_FREE_LARGE(loghandle->lgh_hdr, loghandle->lgh_hdr_size);
  91 out:
  92         OBD_FREE_PTR(loghandle);
  93 }
  94
  95 struct llog_handle *llog_handle_get(struct llog_handle *loghandle)
  96 {
  97         if (refcount_inc_not_zero(&loghandle->lgh_refcount))
  98                 return loghandle;
  99         return NULL;
 100 }
 101
 102 int llog_handle_put(const struct lu_env *env, struct llog_handle *loghandle)
 103 {
 104         int rc = 0;
 105
 106         if (refcount_dec_and_test(&loghandle->lgh_refcount)) {
 107                 const struct llog_operations *lop;
 108
 109                 rc = llog_handle2ops(loghandle, &lop);
 110                 if (!rc) {
 111                         if (lop->lop_close)
 112                                 rc = lop->lop_close(env, loghandle);
 113                         else
 114                                 rc = -EOPNOTSUPP;
 115                 }
 116                 llog_free_handle(loghandle);
 117         }
 118         return rc;
 119 }
 120
 121 static int llog_declare_destroy(const struct lu_env *env,
 122                                 struct llog_handle *handle,
 123                                 struct thandle *th)
 124 {
 125         const struct llog_operations *lop;
 126         int rc;
 127
 128         ENTRY;
 129
 130         rc = llog_handle2ops(handle, &lop);
 131         if (rc)
 132                 RETURN(rc);
 133         if (lop->lop_declare_destroy == NULL)
 134                 RETURN(-EOPNOTSUPP);
 135
 136         rc = lop->lop_declare_destroy(env, handle, th);
 137
 138         RETURN(rc);
 139 }
 140
 141 int llog_trans_destroy(const struct lu_env *env, struct llog_handle *handle,
 142                        struct thandle *th)
 143 {
 144         const struct llog_operations *lop;
 145         int rc;
 146         ENTRY;
 147
 148         rc = llog_handle2ops(handle, &lop);
 149         if (rc < 0)
 150                 RETURN(rc);
 151         if (lop->lop_destroy == NULL)
 152                 RETURN(-EOPNOTSUPP);
 153
 154         LASSERT(handle->lgh_obj != NULL);
 155         if (!llog_exist(handle))
 156                 RETURN(0);
 157
 158         rc = lop->lop_destroy(env, handle, th);
 159
 160         RETURN(rc);
 161 }
 162
 163 int llog_destroy(const struct lu_env *env, struct llog_handle *handle)
 164 {
 165         const struct llog_operations *lop;
 166         struct dt_device *dt;
 167         struct thandle *th;
 168         int rc;
 169
 170         ENTRY;
 171
 172         rc = llog_handle2ops(handle, &lop);
 173         if (rc < 0)
 174                 RETURN(rc);
 175         if (lop->lop_destroy == NULL)
 176                 RETURN(-EOPNOTSUPP);
 177
 178         if (handle->lgh_obj == NULL) {
 179                 /* if lgh_obj == NULL, then it is from client side destroy */
 180                 rc = lop->lop_destroy(env, handle, NULL);
 181                 RETURN(rc);
 182         }
 183
 184         if (!llog_exist(handle))
 185                 RETURN(0);
 186
 187         dt = lu2dt_dev(handle->lgh_obj->do_lu.lo_dev);
 188
 189         if (unlikely(unlikely(dt->dd_rdonly)))
 190                 RETURN(-EROFS);
 191
 192         th = dt_trans_create(env, dt);
 193         if (IS_ERR(th))
 194                 RETURN(PTR_ERR(th));
 195
 196         rc = llog_declare_destroy(env, handle, th);
 197         if (rc != 0)
 198                 GOTO(out_trans, rc);
 199
 200         rc = dt_trans_start_local(env, dt, th);
 201         if (rc < 0)
 202                 GOTO(out_trans, rc);
 203
 204         rc = lop->lop_destroy(env, handle, th);
 205
 206 out_trans:
 207         dt_trans_stop(env, dt, th);
 208
 209         RETURN(rc);
 210 }
 211 EXPORT_SYMBOL(llog_destroy);
 212
 213 /* returns negative on error; 0 if success; 1 if success & log destroyed */
 214 int llog_cancel_arr_rec(const struct lu_env *env, struct llog_handle *loghandle,
 215                         int num, int *index)
 216 {
 217         struct llog_thread_info *lgi = llog_info(env);
 218         struct dt_device        *dt;
 219         struct llog_log_hdr     *llh;
 220         struct thandle          *th;
 221         __u32                    tmp_lgc_index;
 222         int                      rc, i = 0;
 223         int rc1;
 224         bool subtract_count = false;
 225
 226         ENTRY;
 227
 228         LASSERT(loghandle != NULL);
 229         LASSERT(loghandle->lgh_ctxt != NULL);
 230         LASSERT(loghandle->lgh_obj != NULL);
 231
 232         llh = loghandle->lgh_hdr;
 233
 234         CDEBUG(D_RPCTRACE, "Canceling %d records, first %d in log "DFID"\n",
 235                num, index[0], PLOGID(&loghandle->lgh_id));
 236
 237         dt = lu2dt_dev(loghandle->lgh_obj->do_lu.lo_dev);
 238
 239         if (unlikely(unlikely(dt->dd_rdonly)))
 240                 RETURN(0);
 241
 242         th = dt_trans_create(env, dt);
 243         if (IS_ERR(th))
 244                 RETURN(PTR_ERR(th));
 245
 246         rc = llog_declare_write_rec(env, loghandle, &llh->llh_hdr, 0, th);
 247         if (rc < 0)
 248                 GOTO(out_trans, rc);
 249
 250         if ((llh->llh_flags & LLOG_F_ZAP_WHEN_EMPTY)) {
 251                 rc = llog_declare_destroy(env, loghandle, th);
 252                 if (rc < 0)
 253                         GOTO(out_trans, rc);
 254         }
 255
 256         th->th_wait_submit = 1;
 257         rc = dt_trans_start_local(env, dt, th);
 258         if (rc < 0)
 259                 GOTO(out_trans, rc);
 260
 261         down_write(&loghandle->lgh_lock);
 262         /* clear bitmap */
 263         mutex_lock(&loghandle->lgh_hdr_mutex);
 264         for (i = 0; i < num; ++i) {
 265                 if (index[i] == 0) {
 266                         CERROR("Can't cancel index 0 which is header\n");
 267                         GOTO(out_unlock, rc = -EINVAL);
 268                 }
 269                 if (!__test_and_clear_bit_le(index[i], LLOG_HDR_BITMAP(llh))) {
 270                         CDEBUG(D_RPCTRACE, "Catalog index %u already clear?\n",
 271                                index[i]);
 272                         GOTO(out_unlock, rc = -ENOENT);
 273                 }
 274         }
 275         loghandle->lgh_hdr->llh_count -= num;
 276         subtract_count = true;
 277
 278         /* Since llog_process_thread use lgi_cookie, it`s better to save them
 279          * and restore after using
 280          */
 281         tmp_lgc_index = lgi->lgi_cookie.lgc_index;
 282         /* Pass this index to llog_osd_write_rec(), which will use the index
 283          * to only update the necesary bitmap. */
 284         lgi->lgi_cookie.lgc_index = index[0];
 285         /* update header */
 286         rc = llog_write_rec(env, loghandle, &llh->llh_hdr, (num != 1 ? NULL :
 287                             &lgi->lgi_cookie), LLOG_HEADER_IDX, th);
 288         lgi->lgi_cookie.lgc_index = tmp_lgc_index;
 289
 290         if (rc != 0)
 291                 GOTO(out_unlock, rc);
 292
 293         if ((llh->llh_flags & LLOG_F_ZAP_WHEN_EMPTY) &&
 294             (llh->llh_count == 1) &&
 295             ((loghandle->lgh_last_idx == LLOG_HDR_BITMAP_SIZE(llh) - 1) ||
 296              (loghandle->u.phd.phd_cat_handle != NULL &&
 297               loghandle->u.phd.phd_cat_handle->u.chd.chd_current_log !=
 298                 loghandle))) {
 299                 /* never try to destroy it again */
 300                 llh->llh_flags &= ~LLOG_F_ZAP_WHEN_EMPTY;
 301                 rc = llog_trans_destroy(env, loghandle, th);
 302                 if (rc < 0) {
 303                         /* Sigh, can not destroy the final plain llog, but
 304                          * the bitmap has been clearly, so the record can not
 305                          * be accessed anymore, let's return 0 for now, and
 306                          * the orphan will be handled by LFSCK. */
 307                         CERROR("%s: can't destroy empty llog "DFID": rc = %d\n",
 308                                loghandle2name(loghandle),
 309                                PLOGID(&loghandle->lgh_id), rc);
 310                         GOTO(out_unlock, rc = 0);
 311                 }
 312                 rc = LLOG_DEL_PLAIN;
 313         }
 314
 315 out_unlock:
 316         if (rc < 0) {
 317                 /* restore bitmap while holding a mutex */
 318                 if (subtract_count) {
 319                         loghandle->lgh_hdr->llh_count += num;
 320                         subtract_count = false;
 321                 }
 322                 for (i = i - 1; i >= 0; i--)
 323                         set_bit_le(index[i], LLOG_HDR_BITMAP(llh));
 324         }
 325         mutex_unlock(&loghandle->lgh_hdr_mutex);
 326         up_write(&loghandle->lgh_lock);
 327 out_trans:
 328         rc1 = dt_trans_stop(env, dt, th);
 329         if (rc == 0)
 330                 rc = rc1;
 331         if (rc1 < 0) {
 332                 mutex_lock(&loghandle->lgh_hdr_mutex);
 333                 if (subtract_count)
 334                         loghandle->lgh_hdr->llh_count += num;
 335                 for (i = i - 1; i >= 0; i--)
 336                         set_bit_le(index[i], LLOG_HDR_BITMAP(llh));
 337                 mutex_unlock(&loghandle->lgh_hdr_mutex);
 338         }
 339         RETURN(rc);
 340 }
 341
 342 int llog_cancel_rec(const struct lu_env *env, struct llog_handle *loghandle,
 343                     int index)
 344 {
 345         return llog_cancel_arr_rec(env, loghandle, 1, &index);
 346 }
 347
 348 int llog_read_header(const struct lu_env *env, struct llog_handle *handle,
 349                      const struct obd_uuid *uuid)
 350 {
 351         const struct llog_operations *lop;
 352         int rc;
 353         ENTRY;
 354
 355         rc = llog_handle2ops(handle, &lop);
 356         if (rc)
 357                 RETURN(rc);
 358
 359         if (lop->lop_read_header == NULL)
 360                 RETURN(-EOPNOTSUPP);
 361
 362         rc = lop->lop_read_header(env, handle);
 363         if (rc == LLOG_EEMPTY) {
 364                 struct llog_log_hdr *llh = handle->lgh_hdr;
 365
 366                 /* lrh_len should be initialized in llog_init_handle */
 367                 handle->lgh_last_idx = 0; /* header is record with index 0 */
 368                 llh->llh_count = 1;         /* for the header record */
 369                 llh->llh_hdr.lrh_type = LLOG_HDR_MAGIC;
 370                 LASSERT(handle->lgh_ctxt->loc_chunk_size >=
 371                                                 LLOG_MIN_CHUNK_SIZE);
 372                 llh->llh_hdr.lrh_len = handle->lgh_ctxt->loc_chunk_size;
 373                 llh->llh_hdr.lrh_index = 0;
 374                 llh->llh_timestamp = ktime_get_real_seconds();
 375                 if (uuid)
 376                         memcpy(&llh->llh_tgtuuid, uuid,
 377                                sizeof(llh->llh_tgtuuid));
 378                 llh->llh_bitmap_offset = offsetof(typeof(*llh), llh_bitmap);
 379                 /* Since update llog header might also call this function,
 380                  * let's reset the bitmap to 0 here */
 381                 memset(LLOG_HDR_BITMAP(llh), 0, llh->llh_hdr.lrh_len -
 382                                                 llh->llh_bitmap_offset -
 383                                                 sizeof(llh->llh_tail));
 384                 set_bit_le(0, LLOG_HDR_BITMAP(llh));
 385                 LLOG_HDR_TAIL(llh)->lrt_len = llh->llh_hdr.lrh_len;
 386                 LLOG_HDR_TAIL(llh)->lrt_index = llh->llh_hdr.lrh_index;
 387                 rc = 0;
 388         }
 389         RETURN(rc);
 390 }
 391 EXPORT_SYMBOL(llog_read_header);
 392
 393 int llog_init_handle(const struct lu_env *env, struct llog_handle *handle,
 394                      int flags, struct obd_uuid *uuid)
 395 {
 396         struct llog_log_hdr     *llh;
 397         enum llog_flag           fmt = flags & LLOG_F_EXT_MASK;
 398         int                      rc;
 399         int                     chunk_size = handle->lgh_ctxt->loc_chunk_size;
 400         ENTRY;
 401
 402         LASSERT(handle->lgh_hdr == NULL);
 403
 404         LASSERT(chunk_size >= LLOG_MIN_CHUNK_SIZE);
 405         OBD_ALLOC_LARGE(llh, chunk_size);
 406         if (llh == NULL)
 407                 RETURN(-ENOMEM);
 408
 409         handle->lgh_hdr = llh;
 410         handle->lgh_hdr_size = chunk_size;
 411         /* first assign flags to use llog_client_ops */
 412         llh->llh_flags = flags;
 413         rc = llog_read_header(env, handle, uuid);
 414         if (rc == 0) {
 415                 if (unlikely((llh->llh_flags & LLOG_F_IS_PLAIN &&
 416                               flags & LLOG_F_IS_CAT) ||
 417                              (llh->llh_flags & LLOG_F_IS_CAT &&
 418                               flags & LLOG_F_IS_PLAIN))) {
 419                         CERROR("%s: llog type is %s but initializing %s\n",
 420                                loghandle2name(handle),
 421                                llh->llh_flags & LLOG_F_IS_CAT ?
 422                                "catalog" : "plain",
 423                                flags & LLOG_F_IS_CAT ? "catalog" : "plain");
 424                         GOTO(out, rc = -EINVAL);
 425                 } else if (llh->llh_flags &
 426                            (LLOG_F_IS_PLAIN | LLOG_F_IS_CAT)) {
 427                         /*
 428                          * it is possible to open llog without specifying llog
 429                          * type so it is taken from llh_flags
 430                          */
 431                         flags = llh->llh_flags;
 432                 } else {
 433                         /* for some reason the llh_flags has no type set */
 434                         CERROR("llog type is not specified!\n");
 435                         GOTO(out, rc = -EINVAL);
 436                 }
 437                 if (unlikely(uuid &&
 438                              !obd_uuid_equals(uuid, &llh->llh_tgtuuid))) {
 439                         CERROR("%s: llog uuid mismatch: %s/%s\n",
 440                                loghandle2name(handle),
 441                                (char *)uuid->uuid,
 442                                (char *)llh->llh_tgtuuid.uuid);
 443                         GOTO(out, rc = -EEXIST);
 444                 }
 445         }
 446         if (flags & LLOG_F_IS_CAT) {
 447                 LASSERT(list_empty(&handle->u.chd.chd_head));
 448                 INIT_LIST_HEAD(&handle->u.chd.chd_head);
 449                 llh->llh_size = sizeof(struct llog_logid_rec);
 450                 llh->llh_flags |= LLOG_F_IS_FIXSIZE;
 451         } else if (!(flags & LLOG_F_IS_PLAIN)) {
 452                 CERROR("%s: unknown flags: %#x (expected %#x or %#x)\n",
 453                        loghandle2name(handle), flags, LLOG_F_IS_CAT,
 454                        LLOG_F_IS_PLAIN);
 455                 rc = -EINVAL;
 456         }
 457         llh->llh_flags |= fmt;
 458 out:
 459         if (rc) {
 460                 OBD_FREE_LARGE(llh, chunk_size);
 461                 handle->lgh_hdr = NULL;
 462         }
 463         RETURN(rc);
 464 }
 465 EXPORT_SYMBOL(llog_init_handle);
 466
 467 #define LLOG_ERROR_REC(lgh, rec, format, a...) \
 468         CERROR("%s: "DFID" rec type=%x idx=%u len=%u, " format "\n" , \
 469                loghandle2name(lgh), PLOGID(&lgh->lgh_id), (rec)->lrh_type, \
 470                (rec)->lrh_index, (rec)->lrh_len, ##a)
 471
 472 int llog_verify_record(const struct llog_handle *llh, struct llog_rec_hdr *rec)
 473 {
 474         int chunk_size = llh->lgh_hdr->llh_hdr.lrh_len;
 475
 476         if ((rec->lrh_type & LLOG_OP_MASK) != LLOG_OP_MAGIC)
 477                 LLOG_ERROR_REC(llh, rec, "magic is bad");
 478         else if (rec->lrh_len == 0 || rec->lrh_len > chunk_size)
 479                 LLOG_ERROR_REC(llh, rec, "bad record len, chunk size is %d",
 480                                chunk_size);
 481         else if (rec->lrh_index >= LLOG_HDR_BITMAP_SIZE(llh->lgh_hdr))
 482                 LLOG_ERROR_REC(llh, rec, "index is too high");
 483         else
 484                 return 0;
 485
 486         return -EINVAL;
 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
 514         ENTRY;
 515
 516         if (llh == NULL)
 517                 RETURN(-EINVAL);
 518
 519         lti = lpi->lpi_env == NULL ? NULL : llog_info(lpi->lpi_env);
 520
 521         cur_offset = chunk_size = llh->llh_hdr.lrh_len;
 522         /* expect chunk_size to be power of two */
 523         LASSERT(is_power_of_2(chunk_size));
 524
 525         OBD_ALLOC_LARGE(buf, chunk_size);
 526         if (buf == NULL) {
 527                 lpi->lpi_rc = -ENOMEM;
 528                 RETURN(0);
 529         }
 530
 531         if (cd != NULL) {
 532                 last_called_index = cd->lpcd_first_idx;
 533                 index = cd->lpcd_first_idx + 1;
 534         }
 535         if (cd && cd->lpcd_last_idx)
 536                 last_index = cd->lpcd_last_idx;
 537         else if (cd && (cd->lpcd_read_mode & LLOG_READ_MODE_RAW))
 538                 last_index = loghandle->lgh_last_idx;
 539         else
 540                 last_index = LLOG_HDR_BITMAP_SIZE(llh) - 1;
 541
 542         while (rc == 0) {
 543                 struct llog_rec_hdr *rec;
 544                 off_t chunk_offset = 0;
 545                 unsigned int buf_offset = 0;
 546                 int lh_last_idx;
 547                 int synced_idx = 0;
 548
 549                 /* skip records not set in bitmap */
 550                 while (index <= last_index &&
 551                        llog_is_index_skipable(index, llh, cd))
 552                         ++index;
 553
 554                 /* There are no indices prior the last_index */
 555                 if (index > last_index)
 556                         break;
 557
 558                 CDEBUG(D_OTHER, "index: %d last_index %d\n", index,
 559                        last_index);
 560
 561 repeat:
 562                 /* get the buf with our target record; avoid old garbage */
 563                 memset(buf, 0, chunk_size);
 564                 /* the record index for outdated chunk data */
 565                 /* it is safe to process buffer until saved lgh_last_idx */
 566                 lh_last_idx = LLOG_HDR_TAIL(llh)->lrt_index;
 567                 rc = llog_next_block(lpi->lpi_env, loghandle, &saved_index,
 568                                      index, &cur_offset, buf, chunk_size);
 569                 if (repeated && rc)
 570                         CDEBUG(D_OTHER, "cur_offset %llu, chunk_offset %llu,"
 571                                " buf_offset %u, rc = %d\n", cur_offset,
 572                                (__u64)chunk_offset, buf_offset, rc);
 573                 if (rc == -ESTALE)
 574                         GOTO(out, rc = 0);
 575                 /* we`ve tried to reread the chunk, but there is no
 576                  * new records */
 577                 if (repeated && (chunk_offset + buf_offset) == cur_offset &&
 578                     (rc == -EBADR || rc == -EIO))
 579                         GOTO(out, rc = 0);
 580                 /* EOF while trying to skip to the next chunk */
 581                 if (!index && rc == -EBADR)
 582                         GOTO(out, rc = 0);
 583                 if (rc != 0)
 584                         GOTO(out, rc);
 585
 586                 /* NB: after llog_next_block() call the cur_offset is the
 587                  * offset of the next block after read one.
 588                  * The absolute offset of the current chunk is calculated
 589                  * from cur_offset value and stored in chunk_offset variable.
 590                  */
 591                 if ((cur_offset & (chunk_size - 1)) != 0)
 592                         chunk_offset = cur_offset & ~(chunk_size - 1);
 593                 else
 594                         chunk_offset = cur_offset - chunk_size;
 595
 596                 /* NB: when rec->lrh_len is accessed it is already swabbed
 597                  * since it is used at the "end" of the loop and the rec
 598                  * swabbing is done at the beginning of the loop. */
 599                 for (rec = (struct llog_rec_hdr *)(buf + buf_offset);
 600                      (char *)rec < buf + chunk_size;
 601                      rec = llog_rec_hdr_next(rec)) {
 602
 603                         CDEBUG(D_OTHER, "processing rec 0x%p type %#x\n",
 604                                rec, rec->lrh_type);
 605
 606                         if (LLOG_REC_HDR_NEEDS_SWABBING(rec))
 607                                 lustre_swab_llog_rec(rec);
 608
 609                         CDEBUG(D_OTHER, "after swabbing, type=%#x idx=%d\n",
 610                                rec->lrh_type, rec->lrh_index);
 611
 612                         /* start with first rec if block was skipped */
 613                         if (!index) {
 614                                 CDEBUG(D_OTHER,
 615                                        "%s: skipping to the index %u\n",
 616                                        loghandle2name(loghandle),
 617                                        rec->lrh_index);
 618                                 index = rec->lrh_index;
 619                         }
 620
 621                         if (index == (synced_idx + 1) &&
 622                             synced_idx == LLOG_HDR_TAIL(llh)->lrt_index)
 623                                 GOTO(out, rc = 0);
 624
 625                         if (OBD_FAIL_PRECHECK(OBD_FAIL_LLOG_PROCESS_TIMEOUT) &&
 626                                 cfs_fail_val == (unsigned int)
 627                                         (loghandle->lgh_id.lgl_oi.oi.oi_id &
 628                                          0xFFFFFFFF)) {
 629                                 OBD_RACE(OBD_FAIL_LLOG_PROCESS_TIMEOUT);
 630                         }
 631
 632                         /* the bitmap could be changed during processing
 633                          * records from the chunk. For wrapped catalog
 634                          * it means we can read deleted record and try to
 635                          * process it. Check this case and reread the chunk.
 636                          * It is safe to process to lh_last_idx, including
 637                          * lh_last_idx if it was synced. We can not do <=
 638                          * comparison, cause for wrapped catalog lgh_last_idx
 639                          * could be less than index. So we detect last index
 640                          * for processing as index == lh_last_idx+1. But when
 641                          * catalog is wrapped and full lgh_last_idx=llh_cat_idx,
 642                          * the first processing index is llh_cat_idx+1.The
 643                          * exception is !(lgh_last_idx == llh_cat_idx &&
 644                          * index == llh_cat_idx + 1), and after simplification
 645                          * it turns to
 646                          * lh_last_idx != LLOG_HDR_TAIL(llh)->lrt_index
 647                          * This exception is working for catalog only.
 648                          * The last check is for the partial chunk boundary,
 649                          * if it is reached then try to re-read for possible
 650                          * new records once.
 651                          */
 652                         if ((index == lh_last_idx && synced_idx != index) ||
 653                             (index == (lh_last_idx + 1) &&
 654                              lh_last_idx != LLOG_HDR_TAIL(llh)->lrt_index) ||
 655                             (((char *)rec - buf >= cur_offset - chunk_offset) &&
 656                             !repeated)) {
 657                                 /* save offset inside buffer for the re-read */
 658                                 buf_offset = (char *)rec - (char *)buf;
 659                                 cur_offset = chunk_offset;
 660                                 repeated = true;
 661                                 /* We need to be sure lgh_last_idx
 662                                  * record was saved to disk
 663                                  */
 664                                 down_read(&loghandle->lgh_last_sem);
 665                                 synced_idx = LLOG_HDR_TAIL(llh)->lrt_index;
 666                                 up_read(&loghandle->lgh_last_sem);
 667                                 CDEBUG(D_OTHER, "synced_idx: %d\n", synced_idx);
 668                                 goto repeat;
 669                         }
 670                         repeated = false;
 671
 672                         rc = llog_verify_record(loghandle, rec);
 673                         if (rc) {
 674                                 CDEBUG(D_OTHER, "invalid record at index %d\n",
 675                                        index);
 676                                 /*
 677                                  * for fixed-sized llogs we can skip one record
 678                                  * by using llh_size from llog header.
 679                                  * Otherwise skip the next llog chunk.
 680                                  */
 681                                 rc = 0;
 682                                 if (llh->llh_flags & LLOG_F_IS_FIXSIZE) {
 683                                         rec->lrh_len = llh->llh_size;
 684                                         goto next_rec;
 685                                 }
 686                                 /* make sure that is always next block */
 687                                 cur_offset = chunk_offset + chunk_size;
 688                                 /* no goal to find, just next block to read */
 689                                 index = 0;
 690                                 break;
 691                         }
 692
 693                         if (rec->lrh_index < index) {
 694                                 CDEBUG(D_OTHER, "skipping lrh_index %d\n",
 695                                        rec->lrh_index);
 696                                 continue;
 697                         }
 698
 699                         if (rec->lrh_index > index) {
 700                                 /* the record itself looks good, but we met a
 701                                  * gap which can be result of old bugs, just
 702                                  * keep going */
 703                                 LLOG_ERROR_REC(loghandle, rec,
 704                                                "gap in index, expected %u",
 705                                                index);
 706                                 index = rec->lrh_index;
 707                         }
 708
 709                         CDEBUG(D_OTHER,
 710                                "lrh_index: %d lrh_len: %d (%d remains)\n",
 711                                rec->lrh_index, rec->lrh_len,
 712                                (int)(buf + chunk_size - (char *)rec));
 713
 714                         /* lgh_cur_offset is used only at llog_test_3 */
 715                         loghandle->lgh_cur_offset = (char *)rec - (char *)buf +
 716                                                     chunk_offset;
 717
 718                         /* if needed, process the callback on this record */
 719                         if (!llog_is_index_skipable(index, llh, cd)) {
 720                                 struct llog_cookie *lgc;
 721                                 __u64   tmp_off;
 722                                 int     tmp_idx;
 723
 724                                 CDEBUG((llh->llh_flags & LLOG_F_IS_CAT ?
 725                                         D_HA : D_OTHER),
 726                                        "index: %d, lh_last_idx: %d "
 727                                        "synced_idx: %d lgh_last_idx: %d\n",
 728                                        index, lh_last_idx, synced_idx,
 729                                        loghandle->lgh_last_idx);
 730
 731                                 if (lti != NULL) {
 732                                         lgc = &lti->lgi_cookie;
 733                                         /* store lu_env for recursive calls */
 734                                         tmp_off = lgc->lgc_offset;
 735                                         tmp_idx = lgc->lgc_index;
 736
 737                                         lgc->lgc_offset = (char *)rec -
 738                                                 (char *)buf + chunk_offset;
 739                                         lgc->lgc_index = rec->lrh_index;
 740                                 }
 741                                 /* using lu_env for passing record offset to
 742                                  * llog_write through various callbacks */
 743                                 rc = lpi->lpi_cb(lpi->lpi_env, loghandle, rec,
 744                                                  lpi->lpi_cbdata);
 745                                 last_called_index = index;
 746
 747                                 if (lti != NULL) {
 748                                         lgc->lgc_offset = tmp_off;
 749                                         lgc->lgc_index = tmp_idx;
 750                                 }
 751
 752                                 if (rc == LLOG_PROC_BREAK ||
 753                                     rc == LLOG_SKIP_PLAIN) {
 754                                         GOTO(out, rc);
 755                                 } else if (rc == LLOG_DEL_RECORD) {
 756                                         rc = llog_cancel_rec(lpi->lpi_env,
 757                                                              loghandle,
 758                                                              rec->lrh_index);
 759                                         /* Allow parallel cancelling, ENOENT
 760                                          * means record was canceled at another
 761                                          * processing thread or callback
 762                                          */
 763                                         if (rc == -ENOENT)
 764                                                 rc = 0;
 765                                 }
 766                                 if (rc)
 767                                         GOTO(out, rc);
 768                                 /* some stupid callbacks directly cancel records
 769                                  * and delete llog. Check it and stop
 770                                  * processing. */
 771                                 if (loghandle->lgh_hdr == NULL ||
 772                                     loghandle->lgh_hdr->llh_count == 1)
 773                                         GOTO(out, rc = 0);
 774                         }
 775 next_rec:
 776                         /* exit if the last index is reached */
 777                         if (index >= last_index)
 778                                 GOTO(out, rc = 0);
 779                         ++index;
 780                 }
 781         }
 782
 783 out:
 784         CDEBUG(D_HA, "stop processing %s "DFID" index %d count %d\n",
 785                ((llh->llh_flags & LLOG_F_IS_CAT) ? "catalog" : "plain"),
 786                PLOGID(&loghandle->lgh_id), index, llh->llh_count);
 787
 788         if (cd != NULL)
 789                 cd->lpcd_last_idx = last_called_index;
 790
 791         if (unlikely(rc == -EIO && loghandle->lgh_obj != NULL)) {
 792                 if (dt_object_remote(loghandle->lgh_obj)) {
 793                         /* If it is remote object, then -EIO might means
 794                          * disconnection or eviction, let's return -EAGAIN,
 795                          * so for update recovery log processing, it will
 796                          * retry until the umount or abort recovery, see
 797                          * lod_sub_recovery_thread() */
 798                         CERROR("%s retry remote llog process\n",
 799                                loghandle2name(loghandle));
 800                         rc = -EAGAIN;
 801                 } else {
 802                         /* something bad happened to the processing of a local
 803                          * llog file, probably I/O error or the log got
 804                          * corrupted to be able to finally release the log we
 805                          * discard any remaining bits in the header */
 806                         CERROR("%s: local llog is corrupted "DFID" %s index %d count %d\n",
 807                                loghandle2name(loghandle),
 808                                PLOGID(&loghandle->lgh_id),
 809                                ((llh->llh_flags & LLOG_F_IS_CAT) ? "catalog" :
 810                                "plain"), index, llh->llh_count);
 811
 812                         while (index <= last_index) {
 813                                 if (test_bit_le(index,
 814                                                   LLOG_HDR_BITMAP(llh)) != 0)
 815                                         llog_cancel_rec(lpi->lpi_env, loghandle,
 816                                                         index);
 817                                 index++;
 818                         }
 819                         rc = 0;
 820                 }
 821         }
 822
 823         OBD_FREE_LARGE(buf, chunk_size);
 824         lpi->lpi_rc = rc;
 825         return 0;
 826 }
 827
 828 static int llog_process_thread_daemonize(void *arg)
 829 {
 830         struct llog_process_info        *lpi = arg;
 831         struct lu_env                    env;
 832         int                              rc;
 833         struct nsproxy                  *new_ns, *curr_ns = current->nsproxy;
 834
 835         task_lock(lpi->lpi_reftask);
 836         new_ns = lpi->lpi_reftask->nsproxy;
 837         if (curr_ns != new_ns) {
 838                 get_nsproxy(new_ns);
 839
 840                 current->nsproxy = new_ns;
 841                 /* XXX: we should call put_nsproxy() instead of
 842                  * atomic_dec(&ns->count) directly. But put_nsproxy() cannot be
 843                  * used outside of the kernel itself, because it calls
 844                  * free_nsproxy() which is not exported by the kernel
 845                  * (defined in kernel/nsproxy.c) */
 846                 if (curr_ns)
 847                         atomic_dec(&curr_ns->count);
 848         }
 849         task_unlock(lpi->lpi_reftask);
 850
 851         unshare_fs_struct();
 852         /* client env has no keys, tags is just 0 */
 853         rc = lu_env_init(&env, LCT_LOCAL | LCT_MG_THREAD);
 854         if (rc)
 855                 goto out;
 856         lpi->lpi_env = &env;
 857
 858         rc = llog_process_thread(arg);
 859
 860         lu_env_fini(&env);
 861 out:
 862         complete(&lpi->lpi_completion);
 863         return rc;
 864 }
 865
 866 int llog_process_or_fork(const struct lu_env *env,
 867                          struct llog_handle *loghandle,
 868                          llog_cb_t cb, void *data, void *catdata, bool fork)
 869 {
 870         struct llog_process_info *lpi;
 871         struct llog_process_data *d = data;
 872         struct llog_process_cat_data *cd = catdata;
 873         __u32 flags = loghandle->lgh_hdr->llh_flags;
 874         int rc;
 875
 876         ENTRY;
 877
 878         OBD_ALLOC_PTR(lpi);
 879         if (lpi == NULL) {
 880                 CERROR("cannot alloc pointer\n");
 881                 RETURN(-ENOMEM);
 882         }
 883         lpi->lpi_loghandle = loghandle;
 884         lpi->lpi_cb        = cb;
 885         lpi->lpi_cbdata    = data;
 886         lpi->lpi_catdata   = catdata;
 887
 888         CDEBUG(D_OTHER, "Processing "DFID" flags 0x%03x startcat %d startidx %d first_idx %d last_idx %d read_mode %d\n",
 889                PLOGID(&loghandle->lgh_id), flags,
 890                (flags & LLOG_F_IS_CAT) && d ? d->lpd_startcat : -1,
 891                (flags & LLOG_F_IS_CAT) && d ? d->lpd_startidx : -1,
 892                cd ? cd->lpcd_first_idx : -1, cd ? cd->lpcd_last_idx : -1,
 893                cd ? cd->lpcd_read_mode : -1);
 894         if (fork) {
 895                 struct task_struct *task;
 896
 897                 /* The new thread can't use parent env,
 898                  * init the new one in llog_process_thread_daemonize. */
 899                 lpi->lpi_env = NULL;
 900                 init_completion(&lpi->lpi_completion);
 901                 /* take reference to current, so that
 902                  * llog_process_thread_daemonize() can use it to switch to
 903                  * namespace associated with current  */
 904                 lpi->lpi_reftask = current;
 905                 task = kthread_run(llog_process_thread_daemonize, lpi,
 906                                    "llog_process_thread");
 907                 if (IS_ERR(task)) {
 908                         rc = PTR_ERR(task);
 909                         CERROR("%s: cannot start thread: rc = %d\n",
 910                                loghandle2name(loghandle), rc);
 911                         GOTO(out_lpi, rc);
 912                 }
 913                 wait_for_completion(&lpi->lpi_completion);
 914         } else {
 915                 lpi->lpi_env = env;
 916                 llog_process_thread(lpi);
 917         }
 918         rc = lpi->lpi_rc;
 919
 920 out_lpi:
 921         OBD_FREE_PTR(lpi);
 922         RETURN(rc);
 923 }
 924 EXPORT_SYMBOL(llog_process_or_fork);
 925
 926 int llog_process(const struct lu_env *env, struct llog_handle *loghandle,
 927                  llog_cb_t cb, void *data, void *catdata)
 928 {
 929         int rc;
 930         rc = llog_process_or_fork(env, loghandle, cb, data, catdata, true);
 931         return rc == LLOG_DEL_PLAIN ? 0 : rc;
 932 }
 933 EXPORT_SYMBOL(llog_process);
 934
 935 static inline const struct cred *llog_raise_resource(void)
 936 {
 937         struct cred *cred = NULL;
 938
 939         if (cap_raised(current_cap(), CAP_SYS_RESOURCE))
 940                 return cred;
 941
 942         cred = prepare_creds();
 943         if (!cred)
 944                 return cred;
 945
 946         cap_raise(cred->cap_effective, CAP_SYS_RESOURCE);
 947         return override_creds(cred);
 948 }
 949
 950 static inline void llog_restore_resource(const struct cred *old_cred)
 951 {
 952         if (old_cred)
 953                 revert_creds(old_cred);
 954 }
 955
 956 int llog_reverse_process(const struct lu_env *env,
 957                          struct llog_handle *loghandle, llog_cb_t cb,
 958                          void *data, void *catdata)
 959 {
 960         struct llog_log_hdr *llh = loghandle->lgh_hdr;
 961         struct llog_process_cat_data *cd = catdata;
 962         void *buf;
 963         int rc = 0, first_index = 1, index, idx;
 964         __u32   chunk_size = llh->llh_hdr.lrh_len;
 965         ENTRY;
 966
 967         OBD_ALLOC_LARGE(buf, chunk_size);
 968         if (buf == NULL)
 969                 RETURN(-ENOMEM);
 970
 971         if (cd != NULL)
 972                 first_index = cd->lpcd_first_idx + 1;
 973         if (cd != NULL && cd->lpcd_last_idx)
 974                 index = cd->lpcd_last_idx;
 975         else
 976                 index = LLOG_HDR_BITMAP_SIZE(llh) - 1;
 977
 978         while (rc == 0) {
 979                 struct llog_rec_hdr *rec;
 980                 struct llog_rec_tail *tail;
 981
 982                 /* skip records not set in bitmap */
 983                 while (index >= first_index &&
 984                        llog_is_index_skipable(index, llh, cd))
 985                         --index;
 986
 987                 LASSERT(index >= first_index - 1);
 988                 if (index == first_index - 1)
 989                         break;
 990
 991                 /* get the buf with our target record; avoid old garbage */
 992                 memset(buf, 0, chunk_size);
 993                 rc = llog_prev_block(env, loghandle, index, buf, chunk_size);
 994                 if (rc)
 995                         GOTO(out, rc);
 996
 997                 rec = buf;
 998                 idx = rec->lrh_index;
 999                 CDEBUG(D_RPCTRACE, "index %u : idx %u\n", index, idx);
1000                 while (idx < index) {
1001                         rec = (void *)rec + rec->lrh_len;
1002                         if (LLOG_REC_HDR_NEEDS_SWABBING(rec))
1003                                 lustre_swab_llog_rec(rec);
1004                         idx ++;
1005                 }
1006                 LASSERT(idx == index);
1007                 tail = (void *)rec + rec->lrh_len - sizeof(*tail);
1008
1009                 /* process records in buffer, starting where we found one */
1010                 while ((void *)tail > buf) {
1011                         if (tail->lrt_index == 0)
1012                                 GOTO(out, rc = 0); /* no more records */
1013
1014                         /* if needed, process the callback on this record */
1015                         if (!llog_is_index_skipable(index, llh, cd)) {
1016                                 rec = (void *)tail - tail->lrt_len +
1017                                       sizeof(*tail);
1018
1019                                 rc = cb(env, loghandle, rec, data);
1020                                 if (rc == LLOG_PROC_BREAK ||
1021                                     rc == LLOG_SKIP_PLAIN) {
1022                                         GOTO(out, rc);
1023                                 } else if (rc == LLOG_DEL_RECORD) {
1024                                         rc = llog_cancel_rec(env, loghandle,
1025                                                              tail->lrt_index);
1026                                 }
1027                                 if (rc)
1028                                         GOTO(out, rc);
1029                         }
1030
1031                         /* previous record, still in buffer? */
1032                         --index;
1033                         if (index < first_index)
1034                                 GOTO(out, rc = 0);
1035                         tail = (void *)tail - tail->lrt_len;
1036                 }
1037         }
1038
1039 out:
1040         if (buf != NULL)
1041                 OBD_FREE_LARGE(buf, chunk_size);
1042         RETURN(rc);
1043 }
1044 EXPORT_SYMBOL(llog_reverse_process);
1045
1046 /**
1047  * new llog API
1048  *
1049  * API functions:
1050  *      llog_open - open llog, may not exist
1051  *      llog_exist - check if llog exists
1052  *      llog_close - close opened llog, pair for open, frees llog_handle
1053  *      llog_declare_create - declare llog creation
1054  *      llog_create - create new llog on disk, need transaction handle
1055  *      llog_declare_write_rec - declaration of llog write
1056  *      llog_write_rec - write llog record on disk, need transaction handle
1057  *      llog_declare_add - declare llog catalog record addition
1058  *      llog_add - add llog record in catalog, need transaction handle
1059  */
1060 int llog_exist(struct llog_handle *loghandle)
1061 {
1062         const struct llog_operations *lop;
1063         int rc;
1064
1065         ENTRY;
1066
1067         rc = llog_handle2ops(loghandle, &lop);
1068         if (rc)
1069                 RETURN(rc);
1070         if (lop->lop_exist == NULL)
1071                 RETURN(-EOPNOTSUPP);
1072
1073         rc = lop->lop_exist(loghandle);
1074         RETURN(rc);
1075 }
1076 EXPORT_SYMBOL(llog_exist);
1077
1078 int llog_declare_create(const struct lu_env *env,
1079                         struct llog_handle *loghandle, struct thandle *th)
1080 {
1081         const struct cred *old_cred;
1082         const struct llog_operations *lop;
1083         int rc;
1084
1085         ENTRY;
1086
1087         rc = llog_handle2ops(loghandle, &lop);
1088         if (rc)
1089                 RETURN(rc);
1090         if (lop->lop_declare_create == NULL)
1091                 RETURN(-EOPNOTSUPP);
1092
1093         old_cred = llog_raise_resource();
1094         rc = lop->lop_declare_create(env, loghandle, th);
1095         llog_restore_resource(old_cred);
1096         RETURN(rc);
1097 }
1098
1099 int llog_create(const struct lu_env *env, struct llog_handle *handle,
1100                 struct thandle *th)
1101 {
1102         const struct cred *old_cred;
1103         const struct llog_operations *lop;
1104         int rc;
1105
1106         ENTRY;
1107
1108         rc = llog_handle2ops(handle, &lop);
1109         if (rc)
1110                 RETURN(rc);
1111         if (lop->lop_create == NULL)
1112                 RETURN(-EOPNOTSUPP);
1113
1114         old_cred = llog_raise_resource();
1115         rc = lop->lop_create(env, handle, th);
1116         llog_restore_resource(old_cred);
1117         RETURN(rc);
1118 }
1119
1120 int llog_declare_write_rec(const struct lu_env *env,
1121                            struct llog_handle *handle,
1122                            struct llog_rec_hdr *rec, int idx,
1123                            struct thandle *th)
1124 {
1125         const struct cred *old_cred;
1126         const struct llog_operations *lop;
1127         int rc;
1128
1129         ENTRY;
1130
1131         rc = llog_handle2ops(handle, &lop);
1132         if (rc)
1133                 RETURN(rc);
1134         LASSERT(lop);
1135         if (lop->lop_declare_write_rec == NULL)
1136                 RETURN(-EOPNOTSUPP);
1137
1138         old_cred = llog_raise_resource();
1139         rc = lop->lop_declare_write_rec(env, handle, rec, idx, th);
1140         llog_restore_resource(old_cred);
1141         RETURN(rc);
1142 }
1143
1144 int llog_write_rec(const struct lu_env *env, struct llog_handle *handle,
1145                    struct llog_rec_hdr *rec, struct llog_cookie *logcookies,
1146                    int idx, struct thandle *th)
1147 {
1148         const struct cred *old_cred;
1149         const struct llog_operations *lop;
1150         int rc, buflen;
1151
1152         ENTRY;
1153
1154         /* API sanity checks */
1155         if (handle == NULL) {
1156                 CERROR("loghandle is missed\n");
1157                 RETURN(-EPROTO);
1158         } else if (handle->lgh_obj == NULL) {
1159                 CERROR("loghandle %p with NULL object\n",
1160                         handle);
1161                 RETURN(-EPROTO);
1162         } else if (th == NULL) {
1163                 CERROR("%s: missed transaction handle\n",
1164                        loghandle2name(handle));
1165                 RETURN(-EPROTO);
1166         } else if (handle->lgh_hdr == NULL) {
1167                 CERROR("%s: loghandle %p with no header\n",
1168                        loghandle2name(handle), handle);
1169                 RETURN(-EPROTO);
1170         }
1171
1172         rc = llog_handle2ops(handle, &lop);
1173         if (rc)
1174                 RETURN(rc);
1175
1176         if (lop->lop_write_rec == NULL)
1177                 RETURN(-EOPNOTSUPP);
1178
1179         buflen = rec->lrh_len;
1180         LASSERT(cfs_size_round(buflen) == buflen);
1181
1182         old_cred = llog_raise_resource();
1183         rc = lop->lop_write_rec(env, handle, rec, logcookies, idx, th);
1184         llog_restore_resource(old_cred);
1185         RETURN(rc);
1186 }
1187
1188 int llog_add(const struct lu_env *env, struct llog_handle *lgh,
1189              struct llog_rec_hdr *rec, struct llog_cookie *logcookies,
1190              struct thandle *th)
1191 {
1192         const struct cred *old_cred;
1193         int rc;
1194
1195         ENTRY;
1196
1197         if (lgh->lgh_logops->lop_add == NULL)
1198                 RETURN(-EOPNOTSUPP);
1199
1200         old_cred = llog_raise_resource();
1201         rc = lgh->lgh_logops->lop_add(env, lgh, rec, logcookies, th);
1202         llog_restore_resource(old_cred);
1203         RETURN(rc);
1204 }
1205 EXPORT_SYMBOL(llog_add);
1206
1207 int llog_declare_add(const struct lu_env *env, struct llog_handle *lgh,
1208                      struct llog_rec_hdr *rec, struct thandle *th)
1209 {
1210         const struct cred *old_cred;
1211         int rc;
1212
1213         ENTRY;
1214
1215         if (lgh->lgh_logops->lop_declare_add == NULL)
1216                 RETURN(-EOPNOTSUPP);
1217
1218         old_cred = llog_raise_resource();
1219         rc = lgh->lgh_logops->lop_declare_add(env, lgh, rec, th);
1220         llog_restore_resource(old_cred);
1221         RETURN(rc);
1222 }
1223 EXPORT_SYMBOL(llog_declare_add);
1224
1225 /**
1226  * Helper function to open llog or create it if doesn't exist.
1227  * It hides all transaction handling from caller.
1228  */
1229 int llog_open_create(const struct lu_env *env, struct llog_ctxt *ctxt,
1230                      struct llog_handle **res, struct llog_logid *logid,
1231                      char *name)
1232 {
1233         struct dt_device        *d;
1234         struct thandle          *th;
1235         int                      rc;
1236
1237         ENTRY;
1238
1239         rc = llog_open(env, ctxt, res, logid, name, LLOG_OPEN_NEW);
1240         if (rc)
1241                 RETURN(rc);
1242
1243         if (llog_exist(*res))
1244                 RETURN(0);
1245
1246         LASSERT((*res)->lgh_obj != NULL);
1247
1248         d = lu2dt_dev((*res)->lgh_obj->do_lu.lo_dev);
1249
1250         if (unlikely(unlikely(d->dd_rdonly)))
1251                 RETURN(-EROFS);
1252
1253         th = dt_trans_create(env, d);
1254         if (IS_ERR(th))
1255                 GOTO(out, rc = PTR_ERR(th));
1256
1257         /* Create update llog object synchronously, which
1258          * happens during inialization process see
1259          * lod_sub_prep_llog(), to make sure the update
1260          * llog object is created before corss-MDT writing
1261          * updates into the llog object */
1262         if (ctxt->loc_flags & LLOG_CTXT_FLAG_NORMAL_FID)
1263                 th->th_sync = 1;
1264
1265         th->th_wait_submit = 1;
1266         rc = llog_declare_create(env, *res, th);
1267         if (rc == 0) {
1268                 rc = dt_trans_start_local(env, d, th);
1269                 if (rc == 0)
1270                         rc = llog_create(env, *res, th);
1271         }
1272         dt_trans_stop(env, d, th);
1273 out:
1274         if (rc)
1275                 llog_close(env, *res);
1276         RETURN(rc);
1277 }
1278 EXPORT_SYMBOL(llog_open_create);
1279
1280 /**
1281  * Helper function to delete existent llog.
1282  */
1283 int llog_erase(const struct lu_env *env, struct llog_ctxt *ctxt,
1284                struct llog_logid *logid, char *name)
1285 {
1286         struct llog_handle      *handle;
1287         int                      rc = 0, rc2;
1288
1289         ENTRY;
1290
1291         /* nothing to erase */
1292         if (name == NULL && logid == NULL)
1293                 RETURN(0);
1294
1295         rc = llog_open(env, ctxt, &handle, logid, name, LLOG_OPEN_EXISTS);
1296         if (rc < 0)
1297                 RETURN(rc);
1298
1299         rc = llog_init_handle(env, handle, LLOG_F_IS_PLAIN, NULL);
1300         if (rc == 0)
1301                 rc = llog_destroy(env, handle);
1302
1303         rc2 = llog_close(env, handle);
1304         if (rc == 0)
1305                 rc = rc2;
1306         RETURN(rc);
1307 }
1308 EXPORT_SYMBOL(llog_erase);
1309
1310 /*
1311  * Helper function for write record in llog.
1312  * It hides all transaction handling from caller.
1313  * Valid only with local llog.
1314  */
1315 int llog_write(const struct lu_env *env, struct llog_handle *loghandle,
1316                struct llog_rec_hdr *rec, int idx)
1317 {
1318         struct dt_device        *dt;
1319         struct thandle          *th;
1320         bool                    need_cookie;
1321         int                     rc;
1322
1323         ENTRY;
1324
1325         LASSERT(loghandle);
1326         LASSERT(loghandle->lgh_ctxt);
1327         LASSERT(loghandle->lgh_obj != NULL);
1328
1329         dt = lu2dt_dev(loghandle->lgh_obj->do_lu.lo_dev);
1330
1331         if (unlikely(unlikely(dt->dd_rdonly)))
1332                 RETURN(-EROFS);
1333
1334         th = dt_trans_create(env, dt);
1335         if (IS_ERR(th))
1336                 RETURN(PTR_ERR(th));
1337
1338         rc = llog_declare_write_rec(env, loghandle, rec, idx, th);
1339         if (rc)
1340                 GOTO(out_trans, rc);
1341
1342         th->th_wait_submit = 1;
1343         rc = dt_trans_start_local(env, dt, th);
1344         if (rc)
1345                 GOTO(out_trans, rc);
1346
1347         need_cookie = !(idx == LLOG_HEADER_IDX || idx == LLOG_NEXT_IDX);
1348
1349         down_write(&loghandle->lgh_lock);
1350         if (need_cookie) {
1351                 struct llog_thread_info *lti = llog_info(env);
1352
1353                 /* cookie comes from llog_process_thread */
1354                 rc = llog_write_rec(env, loghandle, rec, &lti->lgi_cookie,
1355                                     rec->lrh_index, th);
1356                 /* upper layer didn`t pass cookie so change rc */
1357                 rc = (rc == 1 ? 0 : rc);
1358         } else {
1359                 rc = llog_write_rec(env, loghandle, rec, NULL, idx, th);
1360         }
1361
1362         up_write(&loghandle->lgh_lock);
1363 out_trans:
1364         dt_trans_stop(env, dt, th);
1365         RETURN(rc);
1366 }
1367 EXPORT_SYMBOL(llog_write);
1368
1369 int llog_open(const struct lu_env *env, struct llog_ctxt *ctxt,
1370               struct llog_handle **lgh, struct llog_logid *logid,
1371               char *name, enum llog_open_param open_param)
1372 {
1373         const struct cred *old_cred;
1374         int      rc;
1375
1376         ENTRY;
1377
1378         LASSERT(ctxt);
1379         LASSERT(ctxt->loc_logops);
1380
1381         if (ctxt->loc_logops->lop_open == NULL) {
1382                 *lgh = NULL;
1383                 RETURN(-EOPNOTSUPP);
1384         }
1385
1386         *lgh = llog_alloc_handle();
1387         if (*lgh == NULL)
1388                 RETURN(-ENOMEM);
1389         (*lgh)->lgh_ctxt = ctxt;
1390         (*lgh)->lgh_logops = ctxt->loc_logops;
1391
1392         old_cred = llog_raise_resource();
1393         rc = ctxt->loc_logops->lop_open(env, *lgh, logid, name, open_param);
1394         llog_restore_resource(old_cred);
1395         if (rc) {
1396                 llog_free_handle(*lgh);
1397                 *lgh = NULL;
1398         }
1399         RETURN(rc);
1400 }
1401 EXPORT_SYMBOL(llog_open);
1402
1403 int llog_close(const struct lu_env *env, struct llog_handle *loghandle)
1404 {
1405         return llog_handle_put(env, loghandle);
1406 }
1407 EXPORT_SYMBOL(llog_close);
1408
1409 /**
1410  * Helper function to get the llog size in records. It is used by MGS
1411  * mostly to check that config llog exists and contains data.
1412  *
1413  * \param[in] env       execution environment
1414  * \param[in] ctxt      llog context
1415  * \param[in] name      llog name
1416  *
1417  * \retval              true if there are records in llog besides a header
1418  * \retval              false on error or llog without records
1419  */
1420 int llog_is_empty(const struct lu_env *env, struct llog_ctxt *ctxt,
1421                   char *name)
1422 {
1423         struct llog_handle      *llh;
1424         int                      rc = 0;
1425
1426         rc = llog_open(env, ctxt, &llh, NULL, name, LLOG_OPEN_EXISTS);
1427         if (rc < 0) {
1428                 if (likely(rc == -ENOENT))
1429                         rc = 0;
1430                 GOTO(out, rc);
1431         }
1432
1433         rc = llog_init_handle(env, llh, LLOG_F_IS_PLAIN, NULL);
1434         if (rc)
1435                 GOTO(out_close, rc);
1436         rc = llog_get_size(llh);
1437
1438 out_close:
1439         llog_close(env, llh);
1440 out:
1441         /* The header is record 1, the llog is still considered as empty
1442          * if there is only header */
1443         return (rc <= 1);
1444 }
1445 EXPORT_SYMBOL(llog_is_empty);
1446
1447 /* this callback run in raw read mode (canceled record are processed) */
1448 int llog_copy_handler(const struct lu_env *env, struct llog_handle *llh,
1449                       struct llog_rec_hdr *rec, void *data)
1450 {
1451         struct llog_handle *copy_llh = data;
1452         int idx = rec->lrh_index;
1453         int rc;
1454
1455         ENTRY;
1456
1457         /* Append all records */
1458         rc = llog_write(env, copy_llh, rec, LLOG_NEXT_IDX);
1459
1460         /* Cancel the record if it is canceled on the source */
1461         if (!rc && !test_bit_le(idx, LLOG_HDR_BITMAP(llh->lgh_hdr)))
1462                 rc = llog_cancel_rec(env, copy_llh, copy_llh->lgh_last_idx);
1463
1464         RETURN(rc);
1465 }
1466
1467 /* backup plain llog */
1468 int llog_backup(const struct lu_env *env, struct obd_device *obd,
1469                 struct llog_ctxt *ctxt, struct llog_ctxt *bctxt,
1470                 char *name, char *backup)
1471 {
1472         struct llog_handle *llh, *bllh;
1473         struct llog_process_cat_data cd = {0};
1474         int rc;
1475
1476         ENTRY;
1477
1478         /* open original log */
1479         rc = llog_open(env, ctxt, &llh, NULL, name, LLOG_OPEN_EXISTS);
1480         if (rc < 0) {
1481                 /* the -ENOENT case is also reported to the caller
1482                  * but silently so it should handle that if needed.
1483                  */
1484                 if (rc != -ENOENT)
1485                         CERROR("%s: failed to open log %s: rc = %d\n",
1486                                obd->obd_name, name, rc);
1487                 RETURN(rc);
1488         }
1489
1490         rc = llog_init_handle(env, llh, LLOG_F_IS_PLAIN, NULL);
1491         if (rc)
1492                 GOTO(out_close, rc);
1493
1494         /* Make sure there's no old backup log */
1495         rc = llog_erase(env, bctxt, NULL, backup);
1496         if (rc < 0 && rc != -ENOENT)
1497                 GOTO(out_close, rc);
1498
1499         /* open backup log */
1500         rc = llog_open_create(env, bctxt, &bllh, NULL, backup);
1501         if (rc) {
1502                 CERROR("%s: failed to open backup logfile %s: rc = %d\n",
1503                        obd->obd_name, backup, rc);
1504                 GOTO(out_close, rc);
1505         }
1506
1507         /* check that backup llog is not the same object as original one */
1508         if (llh->lgh_obj == bllh->lgh_obj) {
1509                 CERROR("%s: backup llog %s to itself (%s), objects %p/%p\n",
1510                        obd->obd_name, name, backup, llh->lgh_obj,
1511                        bllh->lgh_obj);
1512                 GOTO(out_backup, rc = -EEXIST);
1513         }
1514
1515         rc = llog_init_handle(env, bllh, LLOG_F_IS_PLAIN, NULL);
1516         if (rc)
1517                 GOTO(out_backup, rc);
1518
1519         /* Read canceled records to have an exact copy */
1520         cd.lpcd_read_mode = LLOG_READ_MODE_RAW;
1521         /* Copy log record by record */
1522         rc = llog_process_or_fork(env, llh, llog_copy_handler, (void *)bllh,
1523                                   &cd, false);
1524         if (rc)
1525                 CERROR("%s: failed to backup log %s: rc = %d\n",
1526                        obd->obd_name, name, rc);
1527 out_backup:
1528         llog_close(env, bllh);
1529 out_close:
1530         llog_close(env, llh);
1531         RETURN(rc);
1532 }
1533 EXPORT_SYMBOL(llog_backup);
1534
1535 /* Get size of llog */
1536 __u64 llog_size(const struct lu_env *env, struct llog_handle *llh)
1537 {
1538         int rc;
1539         struct lu_attr la;
1540
1541         rc = llh->lgh_obj->do_ops->do_attr_get(env, llh->lgh_obj, &la);
1542         if (rc) {
1543                 CERROR("%s: attr_get failed for "DFID": rc = %d\n",
1544                        loghandle2name(llh), PLOGID(&llh->lgh_id), rc);
1545                 return 0;
1546         }
1547
1548         return la.la_size;
1549 }
1550 EXPORT_SYMBOL(llog_size);
1551