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  * Lustre is a trademark of Sun Microsystems, Inc.
  31  *
  32  * lustre/obdclass/llog.c
  33  *
  34  * OST<->MDS recovery logging infrastructure.
  35  * Invariants in implementation:
  36  * - we do not share logs among different OST<->MDS connections, so that
  37  *   if an OST or MDS fails it need only look at log(s) relevant to itself
  38  *
  39  * Author: Andreas Dilger <adilger@clusterfs.com>
  40  * Author: Alex Zhuravlev <bzzz@whamcloud.com>
  41  * Author: Mikhail Pershin <tappro@whamcloud.com>
  42  */
  43
  44 #define DEBUG_SUBSYSTEM S_LOG
  45
  46 #include <linux/pid_namespace.h>
  47 #include <linux/kthread.h>
  48 #include <llog_swab.h>
  49 #include <lustre_log.h>
  50 #include <obd_class.h>
  51 #include "llog_internal.h"
  52 /*
  53  * Allocate a new log or catalog handle
  54  * Used inside llog_open().
  55  */
  56 static struct llog_handle *llog_alloc_handle(void)
  57 {
  58         struct llog_handle *loghandle;
  59
  60         OBD_ALLOC_PTR(loghandle);
  61         if (loghandle == NULL)
  62                 return NULL;
  63
  64         init_rwsem(&loghandle->lgh_lock);
  65         mutex_init(&loghandle->lgh_hdr_mutex);
  66         INIT_LIST_HEAD(&loghandle->u.phd.phd_entry);
  67         atomic_set(&loghandle->lgh_refcount, 1);
  68
  69         return loghandle;
  70 }
  71
  72 /*
  73  * Free llog handle and header data if exists. Used in llog_close() only
  74  */
  75 static void llog_free_handle(struct llog_handle *loghandle)
  76 {
  77         LASSERT(loghandle != NULL);
  78
  79         /* failed llog_init_handle */
  80         if (loghandle->lgh_hdr == NULL)
  81                 goto out;
  82
  83         if (loghandle->lgh_hdr->llh_flags & LLOG_F_IS_PLAIN)
  84                 LASSERT(list_empty(&loghandle->u.phd.phd_entry));
  85         else if (loghandle->lgh_hdr->llh_flags & LLOG_F_IS_CAT)
  86                 LASSERT(list_empty(&loghandle->u.chd.chd_head));
  87         OBD_FREE_LARGE(loghandle->lgh_hdr, loghandle->lgh_hdr_size);
  88 out:
  89         OBD_FREE_PTR(loghandle);
  90 }
  91
  92 void llog_handle_get(struct llog_handle *loghandle)
  93 {
  94         atomic_inc(&loghandle->lgh_refcount);
  95 }
  96
  97 void llog_handle_put(struct llog_handle *loghandle)
  98 {
  99         LASSERT(atomic_read(&loghandle->lgh_refcount) > 0);
 100         if (atomic_dec_and_test(&loghandle->lgh_refcount))
 101                 llog_free_handle(loghandle);
 102 }
 103
 104 static int llog_declare_destroy(const struct lu_env *env,
 105                                 struct llog_handle *handle,
 106                                 struct thandle *th)
 107 {
 108         struct llog_operations *lop;
 109         int rc;
 110
 111         ENTRY;
 112
 113         rc = llog_handle2ops(handle, &lop);
 114         if (rc)
 115                 RETURN(rc);
 116         if (lop->lop_declare_destroy == NULL)
 117                 RETURN(-EOPNOTSUPP);
 118
 119         rc = lop->lop_declare_destroy(env, handle, th);
 120
 121         RETURN(rc);
 122 }
 123
 124 int llog_trans_destroy(const struct lu_env *env, struct llog_handle *handle,
 125                        struct thandle *th)
 126 {
 127         struct llog_operations  *lop;
 128         int rc;
 129         ENTRY;
 130
 131         rc = llog_handle2ops(handle, &lop);
 132         if (rc < 0)
 133                 RETURN(rc);
 134         if (lop->lop_destroy == NULL)
 135                 RETURN(-EOPNOTSUPP);
 136
 137         LASSERT(handle->lgh_obj != NULL);
 138         if (!dt_object_exists(handle->lgh_obj))
 139                 RETURN(0);
 140
 141         rc = lop->lop_destroy(env, handle, th);
 142
 143         RETURN(rc);
 144 }
 145
 146 int llog_destroy(const struct lu_env *env, struct llog_handle *handle)
 147 {
 148         struct llog_operations  *lop;
 149         struct dt_device        *dt;
 150         struct thandle          *th;
 151         int rc;
 152
 153         ENTRY;
 154
 155         rc = llog_handle2ops(handle, &lop);
 156         if (rc < 0)
 157                 RETURN(rc);
 158         if (lop->lop_destroy == NULL)
 159                 RETURN(-EOPNOTSUPP);
 160
 161         if (handle->lgh_obj == NULL) {
 162                 /* if lgh_obj == NULL, then it is from client side destroy */
 163                 rc = lop->lop_destroy(env, handle, NULL);
 164                 RETURN(rc);
 165         }
 166
 167         if (!dt_object_exists(handle->lgh_obj))
 168                 RETURN(0);
 169
 170         dt = lu2dt_dev(handle->lgh_obj->do_lu.lo_dev);
 171
 172         th = dt_trans_create(env, dt);
 173         if (IS_ERR(th))
 174                 RETURN(PTR_ERR(th));
 175
 176         rc = llog_declare_destroy(env, handle, th);
 177         if (rc != 0)
 178                 GOTO(out_trans, rc);
 179
 180         rc = dt_trans_start_local(env, dt, th);
 181         if (rc < 0)
 182                 GOTO(out_trans, rc);
 183
 184         rc = lop->lop_destroy(env, handle, th);
 185
 186 out_trans:
 187         dt_trans_stop(env, dt, th);
 188
 189         RETURN(rc);
 190 }
 191 EXPORT_SYMBOL(llog_destroy);
 192
 193 /* returns negative on error; 0 if success; 1 if success & log destroyed */
 194 int llog_cancel_rec(const struct lu_env *env, struct llog_handle *loghandle,
 195                     int index)
 196 {
 197         struct llog_thread_info *lgi = llog_info(env);
 198         struct dt_device        *dt;
 199         struct llog_log_hdr     *llh;
 200         struct thandle          *th;
 201         int                      rc;
 202         int rc1;
 203         bool subtract_count = false;
 204
 205         ENTRY;
 206
 207         LASSERT(loghandle != NULL);
 208         LASSERT(loghandle->lgh_ctxt != NULL);
 209         LASSERT(loghandle->lgh_obj != NULL);
 210
 211         llh = loghandle->lgh_hdr;
 212
 213         CDEBUG(D_RPCTRACE, "Canceling %d in log "DFID"\n", index,
 214                PFID(&loghandle->lgh_id.lgl_oi.oi_fid));
 215
 216         if (index == 0) {
 217                 CERROR("Can't cancel index 0 which is header\n");
 218                 RETURN(-EINVAL);
 219         }
 220
 221         dt = lu2dt_dev(loghandle->lgh_obj->do_lu.lo_dev);
 222
 223         th = dt_trans_create(env, dt);
 224         if (IS_ERR(th))
 225                 RETURN(PTR_ERR(th));
 226
 227         rc = llog_declare_write_rec(env, loghandle, &llh->llh_hdr, index, th);
 228         if (rc < 0)
 229                 GOTO(out_trans, rc);
 230
 231         if ((llh->llh_flags & LLOG_F_ZAP_WHEN_EMPTY)) {
 232                 rc = llog_declare_destroy(env, loghandle, th);
 233                 if (rc < 0)
 234                         GOTO(out_trans, rc);
 235         }
 236
 237         th->th_wait_submit = 1;
 238         rc = dt_trans_start_local(env, dt, th);
 239         if (rc < 0)
 240                 GOTO(out_trans, rc);
 241
 242         down_write(&loghandle->lgh_lock);
 243         /* clear bitmap */
 244         mutex_lock(&loghandle->lgh_hdr_mutex);
 245         if (!ext2_clear_bit(index, LLOG_HDR_BITMAP(llh))) {
 246                 CDEBUG(D_RPCTRACE, "Catalog index %u already clear?\n", index);
 247                 GOTO(out_unlock, rc);
 248         }
 249
 250         loghandle->lgh_hdr->llh_count--;
 251         subtract_count = true;
 252         /* Pass this index to llog_osd_write_rec(), which will use the index
 253          * to only update the necesary bitmap. */
 254         lgi->lgi_cookie.lgc_index = index;
 255         /* update header */
 256         rc = llog_write_rec(env, loghandle, &llh->llh_hdr, &lgi->lgi_cookie,
 257                             LLOG_HEADER_IDX, th);
 258         if (rc != 0)
 259                 GOTO(out_unlock, rc);
 260
 261         if ((llh->llh_flags & LLOG_F_ZAP_WHEN_EMPTY) &&
 262             (llh->llh_count == 1) &&
 263             ((loghandle->lgh_last_idx == LLOG_HDR_BITMAP_SIZE(llh) - 1) ||
 264              (loghandle->u.phd.phd_cat_handle != NULL &&
 265               loghandle->u.phd.phd_cat_handle->u.chd.chd_current_log !=
 266                 loghandle))) {
 267                 /* never try to destroy it again */
 268                 llh->llh_flags &= ~LLOG_F_ZAP_WHEN_EMPTY;
 269                 rc = llog_trans_destroy(env, loghandle, th);
 270                 if (rc < 0) {
 271                         /* Sigh, can not destroy the final plain llog, but
 272                          * the bitmap has been clearly, so the record can not
 273                          * be accessed anymore, let's return 0 for now, and
 274                          * the orphan will be handled by LFSCK. */
 275                         CERROR("%s: can't destroy empty llog "DFID": rc = %d\n",
 276                                loghandle->lgh_ctxt->loc_obd->obd_name,
 277                                PFID(&loghandle->lgh_id.lgl_oi.oi_fid), rc);
 278                         GOTO(out_unlock, rc = 0);
 279                 }
 280                 rc = LLOG_DEL_PLAIN;
 281         }
 282
 283 out_unlock:
 284         mutex_unlock(&loghandle->lgh_hdr_mutex);
 285         up_write(&loghandle->lgh_lock);
 286 out_trans:
 287         rc1 = dt_trans_stop(env, dt, th);
 288         if (rc == 0)
 289                 rc = rc1;
 290         if (rc < 0 && subtract_count) {
 291                 mutex_lock(&loghandle->lgh_hdr_mutex);
 292                 loghandle->lgh_hdr->llh_count++;
 293                 ext2_set_bit(index, LLOG_HDR_BITMAP(llh));
 294                 mutex_unlock(&loghandle->lgh_hdr_mutex);
 295         }
 296         RETURN(rc);
 297 }
 298
 299 int llog_read_header(const struct lu_env *env, struct llog_handle *handle,
 300                      const struct obd_uuid *uuid)
 301 {
 302         struct llog_operations *lop;
 303         int rc;
 304         ENTRY;
 305
 306         rc = llog_handle2ops(handle, &lop);
 307         if (rc)
 308                 RETURN(rc);
 309
 310         if (lop->lop_read_header == NULL)
 311                 RETURN(-EOPNOTSUPP);
 312
 313         rc = lop->lop_read_header(env, handle);
 314         if (rc == LLOG_EEMPTY) {
 315                 struct llog_log_hdr *llh = handle->lgh_hdr;
 316
 317                 /* lrh_len should be initialized in llog_init_handle */
 318                 handle->lgh_last_idx = 0; /* header is record with index 0 */
 319                 llh->llh_count = 1;         /* for the header record */
 320                 llh->llh_hdr.lrh_type = LLOG_HDR_MAGIC;
 321                 LASSERT(handle->lgh_ctxt->loc_chunk_size >=
 322                                                 LLOG_MIN_CHUNK_SIZE);
 323                 llh->llh_hdr.lrh_len = handle->lgh_ctxt->loc_chunk_size;
 324                 llh->llh_hdr.lrh_index = 0;
 325                 llh->llh_timestamp = ktime_get_real_seconds();
 326                 if (uuid)
 327                         memcpy(&llh->llh_tgtuuid, uuid,
 328                                sizeof(llh->llh_tgtuuid));
 329                 llh->llh_bitmap_offset = offsetof(typeof(*llh), llh_bitmap);
 330                 /* Since update llog header might also call this function,
 331                  * let's reset the bitmap to 0 here */
 332                 memset(LLOG_HDR_BITMAP(llh), 0, llh->llh_hdr.lrh_len -
 333                                                 llh->llh_bitmap_offset -
 334                                                 sizeof(llh->llh_tail));
 335                 ext2_set_bit(0, LLOG_HDR_BITMAP(llh));
 336                 LLOG_HDR_TAIL(llh)->lrt_len = llh->llh_hdr.lrh_len;
 337                 LLOG_HDR_TAIL(llh)->lrt_index = llh->llh_hdr.lrh_index;
 338                 rc = 0;
 339         }
 340         RETURN(rc);
 341 }
 342 EXPORT_SYMBOL(llog_read_header);
 343
 344 int llog_init_handle(const struct lu_env *env, struct llog_handle *handle,
 345                      int flags, struct obd_uuid *uuid)
 346 {
 347         struct llog_log_hdr     *llh;
 348         enum llog_flag           fmt = flags & LLOG_F_EXT_MASK;
 349         int                      rc;
 350         int                     chunk_size = handle->lgh_ctxt->loc_chunk_size;
 351         ENTRY;
 352
 353         LASSERT(handle->lgh_hdr == NULL);
 354
 355         LASSERT(chunk_size >= LLOG_MIN_CHUNK_SIZE);
 356         OBD_ALLOC_LARGE(llh, chunk_size);
 357         if (llh == NULL)
 358                 RETURN(-ENOMEM);
 359
 360         handle->lgh_hdr = llh;
 361         handle->lgh_hdr_size = chunk_size;
 362         /* first assign flags to use llog_client_ops */
 363         llh->llh_flags = flags;
 364         rc = llog_read_header(env, handle, uuid);
 365         if (rc == 0) {
 366                 if (unlikely((llh->llh_flags & LLOG_F_IS_PLAIN &&
 367                               flags & LLOG_F_IS_CAT) ||
 368                              (llh->llh_flags & LLOG_F_IS_CAT &&
 369                               flags & LLOG_F_IS_PLAIN))) {
 370                         CERROR("%s: llog type is %s but initializing %s\n",
 371                                handle->lgh_ctxt->loc_obd->obd_name,
 372                                llh->llh_flags & LLOG_F_IS_CAT ?
 373                                "catalog" : "plain",
 374                                flags & LLOG_F_IS_CAT ? "catalog" : "plain");
 375                         GOTO(out, rc = -EINVAL);
 376                 } else if (llh->llh_flags &
 377                            (LLOG_F_IS_PLAIN | LLOG_F_IS_CAT)) {
 378                         /*
 379                          * it is possible to open llog without specifying llog
 380                          * type so it is taken from llh_flags
 381                          */
 382                         flags = llh->llh_flags;
 383                 } else {
 384                         /* for some reason the llh_flags has no type set */
 385                         CERROR("llog type is not specified!\n");
 386                         GOTO(out, rc = -EINVAL);
 387                 }
 388                 if (unlikely(uuid &&
 389                              !obd_uuid_equals(uuid, &llh->llh_tgtuuid))) {
 390                         CERROR("%s: llog uuid mismatch: %s/%s\n",
 391                                handle->lgh_ctxt->loc_obd->obd_name,
 392                                (char *)uuid->uuid,
 393                                (char *)llh->llh_tgtuuid.uuid);
 394                         GOTO(out, rc = -EEXIST);
 395                 }
 396         }
 397         if (flags & LLOG_F_IS_CAT) {
 398                 LASSERT(list_empty(&handle->u.chd.chd_head));
 399                 INIT_LIST_HEAD(&handle->u.chd.chd_head);
 400                 llh->llh_size = sizeof(struct llog_logid_rec);
 401                 llh->llh_flags |= LLOG_F_IS_FIXSIZE;
 402         } else if (!(flags & LLOG_F_IS_PLAIN)) {
 403                 CERROR("%s: unknown flags: %#x (expected %#x or %#x)\n",
 404                        handle->lgh_ctxt->loc_obd->obd_name,
 405                        flags, LLOG_F_IS_CAT, LLOG_F_IS_PLAIN);
 406                 rc = -EINVAL;
 407         }
 408         llh->llh_flags |= fmt;
 409 out:
 410         if (rc) {
 411                 OBD_FREE_LARGE(llh, chunk_size);
 412                 handle->lgh_hdr = NULL;
 413         }
 414         RETURN(rc);
 415 }
 416 EXPORT_SYMBOL(llog_init_handle);
 417
 418 static int llog_process_thread(void *arg)
 419 {
 420         struct llog_process_info        *lpi = arg;
 421         struct llog_handle              *loghandle = lpi->lpi_loghandle;
 422         struct llog_log_hdr             *llh = loghandle->lgh_hdr;
 423         struct llog_process_cat_data    *cd  = lpi->lpi_catdata;
 424         struct llog_thread_info         *lti;
 425         char                            *buf;
 426         size_t                           chunk_size;
 427         __u64                            cur_offset;
 428         int                              rc = 0, index = 1, last_index;
 429         int                              saved_index = 0;
 430         int                              last_called_index = 0;
 431         bool                             repeated = false;
 432
 433         ENTRY;
 434
 435         if (llh == NULL)
 436                 RETURN(-EINVAL);
 437
 438         lti = lpi->lpi_env == NULL ? NULL : llog_info(lpi->lpi_env);
 439
 440         cur_offset = chunk_size = llh->llh_hdr.lrh_len;
 441         /* expect chunk_size to be power of two */
 442         LASSERT(is_power_of_2(chunk_size));
 443
 444         OBD_ALLOC_LARGE(buf, chunk_size);
 445         if (buf == NULL) {
 446                 lpi->lpi_rc = -ENOMEM;
 447                 RETURN(0);
 448         }
 449
 450         if (cd != NULL) {
 451                 last_called_index = cd->lpcd_first_idx;
 452                 index = cd->lpcd_first_idx + 1;
 453         }
 454         if (cd != NULL && cd->lpcd_last_idx)
 455                 last_index = cd->lpcd_last_idx;
 456         else
 457                 last_index = LLOG_HDR_BITMAP_SIZE(llh) - 1;
 458
 459         while (rc == 0) {
 460                 struct llog_rec_hdr *rec;
 461                 off_t chunk_offset = 0;
 462                 unsigned int buf_offset = 0;
 463                 bool partial_chunk;
 464                 int     lh_last_idx;
 465
 466                 /* skip records not set in bitmap */
 467                 while (index <= last_index &&
 468                        !ext2_test_bit(index, LLOG_HDR_BITMAP(llh)))
 469                         ++index;
 470
 471                 /* There are no indices prior the last_index */
 472                 if (index > last_index)
 473                         break;
 474
 475                 CDEBUG(D_OTHER, "index: %d last_index %d\n", index,
 476                        last_index);
 477
 478 repeat:
 479                 /* get the buf with our target record; avoid old garbage */
 480                 memset(buf, 0, chunk_size);
 481                 /* the record index for outdated chunk data */
 482                 lh_last_idx = loghandle->lgh_last_idx + 1;
 483                 rc = llog_next_block(lpi->lpi_env, loghandle, &saved_index,
 484                                      index, &cur_offset, buf, chunk_size);
 485                 if (repeated && rc)
 486                         CDEBUG(D_OTHER, "cur_offset %llu, chunk_offset %llu,"
 487                                " buf_offset %u, rc = %d\n", cur_offset,
 488                                (__u64)chunk_offset, buf_offset, rc);
 489                 /* we`ve tried to reread the chunk, but there is no
 490                  * new records */
 491                 if (rc == -EIO && repeated && (chunk_offset + buf_offset) ==
 492                     cur_offset)
 493                         GOTO(out, rc = 0);
 494                 if (rc != 0)
 495                         GOTO(out, rc);
 496
 497                 /* NB: after llog_next_block() call the cur_offset is the
 498                  * offset of the next block after read one.
 499                  * The absolute offset of the current chunk is calculated
 500                  * from cur_offset value and stored in chunk_offset variable.
 501                  */
 502                 if ((cur_offset & (chunk_size - 1)) != 0) {
 503                         partial_chunk = true;
 504                         chunk_offset = cur_offset & ~(chunk_size - 1);
 505                 } else {
 506                         partial_chunk = false;
 507                         chunk_offset = cur_offset - chunk_size;
 508                 }
 509
 510                 /* NB: when rec->lrh_len is accessed it is already swabbed
 511                  * since it is used at the "end" of the loop and the rec
 512                  * swabbing is done at the beginning of the loop. */
 513                 for (rec = (struct llog_rec_hdr *)(buf + buf_offset);
 514                      (char *)rec < buf + chunk_size;
 515                      rec = llog_rec_hdr_next(rec)) {
 516
 517                         CDEBUG(D_OTHER, "processing rec 0x%p type %#x\n",
 518                                rec, rec->lrh_type);
 519
 520                         if (LLOG_REC_HDR_NEEDS_SWABBING(rec))
 521                                 lustre_swab_llog_rec(rec);
 522
 523                         CDEBUG(D_OTHER, "after swabbing, type=%#x idx=%d\n",
 524                                rec->lrh_type, rec->lrh_index);
 525
 526                         /* the bitmap could be changed during processing
 527                          * records from the chunk. For wrapped catalog
 528                          * it means we can read deleted record and try to
 529                          * process it. Check this case and reread the chunk. */
 530
 531                         /* for partial chunk the end of it is zeroed, check
 532                          * for index 0 to distinguish it. */
 533                         if ((partial_chunk && rec->lrh_index == 0) ||
 534                              (index == lh_last_idx &&
 535                               lh_last_idx != (loghandle->lgh_last_idx + 1))) {
 536                                 /* concurrent llog_add() might add new records
 537                                  * while llog_processing, check this is not
 538                                  * the case and re-read the current chunk
 539                                  * otherwise. */
 540                                 int records;
 541                                 /* lgh_last_idx could be less then index
 542                                  * for catalog, if catalog is wrapped */
 543                                 if ((index > loghandle->lgh_last_idx &&
 544                                     !(loghandle->lgh_hdr->llh_flags &
 545                                       LLOG_F_IS_CAT)) || repeated ||
 546                                     (loghandle->lgh_obj != NULL &&
 547                                      dt_object_remote(loghandle->lgh_obj)))
 548                                         GOTO(out, rc = 0);
 549                                 /* <2 records means no more records
 550                                  * if the last record we processed was
 551                                  * the final one, then the underlying
 552                                  * object might have been destroyed yet.
 553                                  * we better don't access that.. */
 554                                 mutex_lock(&loghandle->lgh_hdr_mutex);
 555                                 records = loghandle->lgh_hdr->llh_count;
 556                                 mutex_unlock(&loghandle->lgh_hdr_mutex);
 557                                 if (records <= 1)
 558                                         GOTO(out, rc = 0);
 559                                 CDEBUG(D_OTHER, "Re-read last llog buffer for "
 560                                        "new records, index %u, last %u\n",
 561                                        index, loghandle->lgh_last_idx);
 562                                 /* save offset inside buffer for the re-read */
 563                                 buf_offset = (char *)rec - (char *)buf;
 564                                 cur_offset = chunk_offset;
 565                                 repeated = true;
 566                                 goto repeat;
 567                         }
 568
 569                         repeated = false;
 570
 571                         if (rec->lrh_len == 0 || rec->lrh_len > chunk_size) {
 572                                 CWARN("%s: invalid length %d in llog "DFID
 573                                       "record for index %d/%d\n",
 574                                        loghandle->lgh_ctxt->loc_obd->obd_name,
 575                                        rec->lrh_len,
 576                                        PFID(&loghandle->lgh_id.lgl_oi.oi_fid),
 577                                        rec->lrh_index, index);
 578
 579                                 GOTO(out, rc = -EINVAL);
 580                         }
 581
 582                         if (rec->lrh_index < index) {
 583                                 CDEBUG(D_OTHER, "skipping lrh_index %d\n",
 584                                        rec->lrh_index);
 585                                 continue;
 586                         }
 587
 588                         if (rec->lrh_index != index) {
 589                                 CERROR("%s: "DFID" Invalid record: index %u"
 590                                        " but expected %u\n",
 591                                        loghandle->lgh_ctxt->loc_obd->obd_name,
 592                                        PFID(&loghandle->lgh_id.lgl_oi.oi_fid),
 593                                        rec->lrh_index, index);
 594                                 GOTO(out, rc = -ERANGE);
 595                         }
 596
 597                         CDEBUG(D_OTHER,
 598                                "lrh_index: %d lrh_len: %d (%d remains)\n",
 599                                rec->lrh_index, rec->lrh_len,
 600                                (int)(buf + chunk_size - (char *)rec));
 601
 602                         /* lgh_cur_offset is used only at llog_test_3 */
 603                         loghandle->lgh_cur_offset = (char *)rec - (char *)buf +
 604                                                     chunk_offset;
 605
 606                         /* if set, process the callback on this record */
 607                         if (ext2_test_bit(index, LLOG_HDR_BITMAP(llh))) {
 608                                 struct llog_cookie *lgc;
 609                                 __u64   tmp_off;
 610                                 int     tmp_idx;
 611
 612                                 if (lti != NULL) {
 613                                         lgc = &lti->lgi_cookie;
 614                                         /* store lu_env for recursive calls */
 615                                         tmp_off = lgc->lgc_offset;
 616                                         tmp_idx = lgc->lgc_index;
 617
 618                                         lgc->lgc_offset = (char *)rec -
 619                                                 (char *)buf + chunk_offset;
 620                                         lgc->lgc_index = rec->lrh_index;
 621                                 }
 622                                 /* using lu_env for passing record offset to
 623                                  * llog_write through various callbacks */
 624                                 rc = lpi->lpi_cb(lpi->lpi_env, loghandle, rec,
 625                                                  lpi->lpi_cbdata);
 626                                 last_called_index = index;
 627
 628                                 if (lti != NULL) {
 629                                         lgc->lgc_offset = tmp_off;
 630                                         lgc->lgc_index = tmp_idx;
 631                                 }
 632
 633                                 if (rc == LLOG_PROC_BREAK) {
 634                                         GOTO(out, rc);
 635                                 } else if (rc == LLOG_DEL_RECORD) {
 636                                         rc = llog_cancel_rec(lpi->lpi_env,
 637                                                              loghandle,
 638                                                              rec->lrh_index);
 639                                 }
 640                                 if (rc)
 641                                         GOTO(out, rc);
 642                                 /* some stupid callbacks directly cancel records
 643                                  * and delete llog. Check it and stop
 644                                  * processing. */
 645                                 if (loghandle->lgh_hdr == NULL ||
 646                                     loghandle->lgh_hdr->llh_count == 1)
 647                                         GOTO(out, rc = 0);
 648                         }
 649                         /* exit if the last index is reached */
 650                         if (index >= last_index)
 651                                 GOTO(out, rc = 0);
 652                         ++index;
 653                 }
 654         }
 655
 656 out:
 657         if (cd != NULL)
 658                 cd->lpcd_last_idx = last_called_index;
 659
 660         if (unlikely(rc == -EIO && loghandle->lgh_obj != NULL)) {
 661                 if (dt_object_remote(loghandle->lgh_obj)) {
 662                         /* If it is remote object, then -EIO might means
 663                          * disconnection or eviction, let's return -EAGAIN,
 664                          * so for update recovery log processing, it will
 665                          * retry until the umount or abort recovery, see
 666                          * lod_sub_recovery_thread() */
 667                         CERROR("%s retry remote llog process\n",
 668                                loghandle->lgh_ctxt->loc_obd->obd_name);
 669                         rc = -EAGAIN;
 670                 } else {
 671                         /* something bad happened to the processing of a local
 672                          * llog file, probably I/O error or the log got
 673                          * corrupted to be able to finally release the log we
 674                          * discard any remaining bits in the header */
 675                         CERROR("%s: Local llog found corrupted #"DOSTID":%x"
 676                                " %s index %d count %d\n",
 677                                loghandle->lgh_ctxt->loc_obd->obd_name,
 678                                POSTID(&loghandle->lgh_id.lgl_oi),
 679                                loghandle->lgh_id.lgl_ogen,
 680                                ((llh->llh_flags & LLOG_F_IS_CAT) ? "catalog" :
 681                                 "plain"), index, llh->llh_count);
 682
 683                         while (index <= last_index) {
 684                                 if (ext2_test_bit(index,
 685                                                   LLOG_HDR_BITMAP(llh)) != 0)
 686                                         llog_cancel_rec(lpi->lpi_env, loghandle,
 687                                                         index);
 688                                 index++;
 689                         }
 690                         rc = 0;
 691                 }
 692         }
 693
 694         OBD_FREE_LARGE(buf, chunk_size);
 695         lpi->lpi_rc = rc;
 696         return 0;
 697 }
 698
 699 static int llog_process_thread_daemonize(void *arg)
 700 {
 701         struct llog_process_info        *lpi = arg;
 702         struct lu_env                    env;
 703         int                              rc;
 704         struct nsproxy                  *new_ns, *curr_ns = current->nsproxy;
 705
 706         task_lock(lpi->lpi_reftask);
 707         new_ns = lpi->lpi_reftask->nsproxy;
 708         if (curr_ns != new_ns) {
 709                 get_nsproxy(new_ns);
 710
 711                 current->nsproxy = new_ns;
 712                 /* XXX: we should call put_nsproxy() instead of
 713                  * atomic_dec(&ns->count) directly. But put_nsproxy() cannot be
 714                  * used outside of the kernel itself, because it calls
 715                  * free_nsproxy() which is not exported by the kernel
 716                  * (defined in kernel/nsproxy.c) */
 717                 atomic_dec(&curr_ns->count);
 718         }
 719         task_unlock(lpi->lpi_reftask);
 720
 721         unshare_fs_struct();
 722
 723         /* client env has no keys, tags is just 0 */
 724         rc = lu_env_init(&env, LCT_LOCAL | LCT_MG_THREAD);
 725         if (rc)
 726                 goto out;
 727         lpi->lpi_env = &env;
 728
 729         rc = llog_process_thread(arg);
 730
 731         lu_env_fini(&env);
 732 out:
 733         complete(&lpi->lpi_completion);
 734         return rc;
 735 }
 736
 737 int llog_process_or_fork(const struct lu_env *env,
 738                          struct llog_handle *loghandle,
 739                          llog_cb_t cb, void *data, void *catdata, bool fork)
 740 {
 741         struct llog_process_info *lpi;
 742         int                      rc;
 743
 744         ENTRY;
 745
 746         OBD_ALLOC_PTR(lpi);
 747         if (lpi == NULL) {
 748                 CERROR("cannot alloc pointer\n");
 749                 RETURN(-ENOMEM);
 750         }
 751         lpi->lpi_loghandle = loghandle;
 752         lpi->lpi_cb        = cb;
 753         lpi->lpi_cbdata    = data;
 754         lpi->lpi_catdata   = catdata;
 755
 756         if (fork) {
 757                 struct task_struct *task;
 758
 759                 /* The new thread can't use parent env,
 760                  * init the new one in llog_process_thread_daemonize. */
 761                 lpi->lpi_env = NULL;
 762                 init_completion(&lpi->lpi_completion);
 763                 /* take reference to current, so that
 764                  * llog_process_thread_daemonize() can use it to switch to
 765                  * namespace associated with current  */
 766                 lpi->lpi_reftask = current;
 767                 task = kthread_run(llog_process_thread_daemonize, lpi,
 768                                    "llog_process_thread");
 769                 if (IS_ERR(task)) {
 770                         rc = PTR_ERR(task);
 771                         CERROR("%s: cannot start thread: rc = %d\n",
 772                                loghandle->lgh_ctxt->loc_obd->obd_name, rc);
 773                         GOTO(out_lpi, rc);
 774                 }
 775                 wait_for_completion(&lpi->lpi_completion);
 776         } else {
 777                 lpi->lpi_env = env;
 778                 llog_process_thread(lpi);
 779         }
 780         rc = lpi->lpi_rc;
 781
 782 out_lpi:
 783         OBD_FREE_PTR(lpi);
 784         RETURN(rc);
 785 }
 786 EXPORT_SYMBOL(llog_process_or_fork);
 787
 788 int llog_process(const struct lu_env *env, struct llog_handle *loghandle,
 789                  llog_cb_t cb, void *data, void *catdata)
 790 {
 791         int rc;
 792         rc = llog_process_or_fork(env, loghandle, cb, data, catdata, true);
 793         return rc == LLOG_DEL_PLAIN ? 0 : rc;
 794 }
 795 EXPORT_SYMBOL(llog_process);
 796
 797 int llog_reverse_process(const struct lu_env *env,
 798                          struct llog_handle *loghandle, llog_cb_t cb,
 799                          void *data, void *catdata)
 800 {
 801         struct llog_log_hdr *llh = loghandle->lgh_hdr;
 802         struct llog_process_cat_data *cd = catdata;
 803         void *buf;
 804         int rc = 0, first_index = 1, index, idx;
 805         __u32   chunk_size = llh->llh_hdr.lrh_len;
 806         ENTRY;
 807
 808         OBD_ALLOC_LARGE(buf, chunk_size);
 809         if (buf == NULL)
 810                 RETURN(-ENOMEM);
 811
 812         if (cd != NULL)
 813                 first_index = cd->lpcd_first_idx + 1;
 814         if (cd != NULL && cd->lpcd_last_idx)
 815                 index = cd->lpcd_last_idx;
 816         else
 817                 index = LLOG_HDR_BITMAP_SIZE(llh) - 1;
 818
 819         while (rc == 0) {
 820                 struct llog_rec_hdr *rec;
 821                 struct llog_rec_tail *tail;
 822
 823                 /* skip records not set in bitmap */
 824                 while (index >= first_index &&
 825                        !ext2_test_bit(index, LLOG_HDR_BITMAP(llh)))
 826                         --index;
 827
 828                 LASSERT(index >= first_index - 1);
 829                 if (index == first_index - 1)
 830                         break;
 831
 832                 /* get the buf with our target record; avoid old garbage */
 833                 memset(buf, 0, chunk_size);
 834                 rc = llog_prev_block(env, loghandle, index, buf, chunk_size);
 835                 if (rc)
 836                         GOTO(out, rc);
 837
 838                 rec = buf;
 839                 idx = rec->lrh_index;
 840                 CDEBUG(D_RPCTRACE, "index %u : idx %u\n", index, idx);
 841                 while (idx < index) {
 842                         rec = (void *)rec + rec->lrh_len;
 843                         if (LLOG_REC_HDR_NEEDS_SWABBING(rec))
 844                                 lustre_swab_llog_rec(rec);
 845                         idx ++;
 846                 }
 847                 LASSERT(idx == index);
 848                 tail = (void *)rec + rec->lrh_len - sizeof(*tail);
 849
 850                 /* process records in buffer, starting where we found one */
 851                 while ((void *)tail > buf) {
 852                         if (tail->lrt_index == 0)
 853                                 GOTO(out, rc = 0); /* no more records */
 854
 855                         /* if set, process the callback on this record */
 856                         if (ext2_test_bit(index, LLOG_HDR_BITMAP(llh))) {
 857                                 rec = (void *)tail - tail->lrt_len +
 858                                       sizeof(*tail);
 859
 860                                 rc = cb(env, loghandle, rec, data);
 861                                 if (rc == LLOG_PROC_BREAK) {
 862                                         GOTO(out, rc);
 863                                 } else if (rc == LLOG_DEL_RECORD) {
 864                                         rc = llog_cancel_rec(env, loghandle,
 865                                                              tail->lrt_index);
 866                                 }
 867                                 if (rc)
 868                                         GOTO(out, rc);
 869                         }
 870
 871                         /* previous record, still in buffer? */
 872                         --index;
 873                         if (index < first_index)
 874                                 GOTO(out, rc = 0);
 875                         tail = (void *)tail - tail->lrt_len;
 876                 }
 877         }
 878
 879 out:
 880         if (buf != NULL)
 881                 OBD_FREE_LARGE(buf, chunk_size);
 882         RETURN(rc);
 883 }
 884 EXPORT_SYMBOL(llog_reverse_process);
 885
 886 /**
 887  * new llog API
 888  *
 889  * API functions:
 890  *      llog_open - open llog, may not exist
 891  *      llog_exist - check if llog exists
 892  *      llog_close - close opened llog, pair for open, frees llog_handle
 893  *      llog_declare_create - declare llog creation
 894  *      llog_create - create new llog on disk, need transaction handle
 895  *      llog_declare_write_rec - declaration of llog write
 896  *      llog_write_rec - write llog record on disk, need transaction handle
 897  *      llog_declare_add - declare llog catalog record addition
 898  *      llog_add - add llog record in catalog, need transaction handle
 899  */
 900 int llog_exist(struct llog_handle *loghandle)
 901 {
 902         struct llog_operations  *lop;
 903         int                      rc;
 904
 905         ENTRY;
 906
 907         rc = llog_handle2ops(loghandle, &lop);
 908         if (rc)
 909                 RETURN(rc);
 910         if (lop->lop_exist == NULL)
 911                 RETURN(-EOPNOTSUPP);
 912
 913         rc = lop->lop_exist(loghandle);
 914         RETURN(rc);
 915 }
 916 EXPORT_SYMBOL(llog_exist);
 917
 918 int llog_declare_create(const struct lu_env *env,
 919                         struct llog_handle *loghandle, struct thandle *th)
 920 {
 921         struct llog_operations  *lop;
 922         int                      raised, rc;
 923
 924         ENTRY;
 925
 926         rc = llog_handle2ops(loghandle, &lop);
 927         if (rc)
 928                 RETURN(rc);
 929         if (lop->lop_declare_create == NULL)
 930                 RETURN(-EOPNOTSUPP);
 931
 932         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 933         if (!raised)
 934                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 935         rc = lop->lop_declare_create(env, loghandle, th);
 936         if (!raised)
 937                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 938         RETURN(rc);
 939 }
 940
 941 int llog_create(const struct lu_env *env, struct llog_handle *handle,
 942                 struct thandle *th)
 943 {
 944         struct llog_operations  *lop;
 945         int                      raised, rc;
 946
 947         ENTRY;
 948
 949         rc = llog_handle2ops(handle, &lop);
 950         if (rc)
 951                 RETURN(rc);
 952         if (lop->lop_create == NULL)
 953                 RETURN(-EOPNOTSUPP);
 954
 955         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 956         if (!raised)
 957                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 958         rc = lop->lop_create(env, handle, th);
 959         if (!raised)
 960                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 961         RETURN(rc);
 962 }
 963
 964 int llog_declare_write_rec(const struct lu_env *env,
 965                            struct llog_handle *handle,
 966                            struct llog_rec_hdr *rec, int idx,
 967                            struct thandle *th)
 968 {
 969         struct llog_operations  *lop;
 970         int                      raised, rc;
 971
 972         ENTRY;
 973
 974         rc = llog_handle2ops(handle, &lop);
 975         if (rc)
 976                 RETURN(rc);
 977         LASSERT(lop);
 978         if (lop->lop_declare_write_rec == NULL)
 979                 RETURN(-EOPNOTSUPP);
 980
 981         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 982         if (!raised)
 983                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 984         rc = lop->lop_declare_write_rec(env, handle, rec, idx, th);
 985         if (!raised)
 986                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 987         RETURN(rc);
 988 }
 989
 990 int llog_write_rec(const struct lu_env *env, struct llog_handle *handle,
 991                    struct llog_rec_hdr *rec, struct llog_cookie *logcookies,
 992                    int idx, struct thandle *th)
 993 {
 994         struct llog_operations  *lop;
 995         int                      raised, rc, buflen;
 996
 997         ENTRY;
 998
 999         /* API sanity checks */
1000         if (handle == NULL) {
1001                 CERROR("loghandle is missed\n");
1002                 RETURN(-EPROTO);
1003         } else if (handle->lgh_obj == NULL) {
1004                 CERROR("loghandle %p with NULL object\n",
1005                         handle);
1006                 RETURN(-EPROTO);
1007         } else if (th == NULL) {
1008                 CERROR("%s: missed transaction handle\n",
1009                         handle->lgh_obj->do_lu.lo_dev->ld_obd->obd_name);
1010                 RETURN(-EPROTO);
1011         } else if (handle->lgh_hdr == NULL) {
1012                 CERROR("%s: loghandle %p with no header\n",
1013                         handle->lgh_obj->do_lu.lo_dev->ld_obd->obd_name,
1014                         handle);
1015                 RETURN(-EPROTO);
1016         }
1017
1018         rc = llog_handle2ops(handle, &lop);
1019         if (rc)
1020                 RETURN(rc);
1021
1022         if (lop->lop_write_rec == NULL)
1023                 RETURN(-EOPNOTSUPP);
1024
1025         buflen = rec->lrh_len;
1026         LASSERT(cfs_size_round(buflen) == buflen);
1027
1028         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
1029         if (!raised)
1030                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
1031         rc = lop->lop_write_rec(env, handle, rec, logcookies, idx, th);
1032         if (!raised)
1033                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
1034         RETURN(rc);
1035 }
1036
1037 int llog_add(const struct lu_env *env, struct llog_handle *lgh,
1038              struct llog_rec_hdr *rec, struct llog_cookie *logcookies,
1039              struct thandle *th)
1040 {
1041         int raised, rc;
1042
1043         ENTRY;
1044
1045         if (lgh->lgh_logops->lop_add == NULL)
1046                 RETURN(-EOPNOTSUPP);
1047
1048         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
1049         if (!raised)
1050                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
1051         rc = lgh->lgh_logops->lop_add(env, lgh, rec, logcookies, th);
1052         if (!raised)
1053                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
1054         RETURN(rc);
1055 }
1056 EXPORT_SYMBOL(llog_add);
1057
1058 int llog_declare_add(const struct lu_env *env, struct llog_handle *lgh,
1059                      struct llog_rec_hdr *rec, struct thandle *th)
1060 {
1061         int raised, rc;
1062
1063         ENTRY;
1064
1065         if (lgh->lgh_logops->lop_declare_add == NULL)
1066                 RETURN(-EOPNOTSUPP);
1067
1068         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
1069         if (!raised)
1070                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
1071         rc = lgh->lgh_logops->lop_declare_add(env, lgh, rec, th);
1072         if (!raised)
1073                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
1074         RETURN(rc);
1075 }
1076 EXPORT_SYMBOL(llog_declare_add);
1077
1078 /**
1079  * Helper function to open llog or create it if doesn't exist.
1080  * It hides all transaction handling from caller.
1081  */
1082 int llog_open_create(const struct lu_env *env, struct llog_ctxt *ctxt,
1083                      struct llog_handle **res, struct llog_logid *logid,
1084                      char *name)
1085 {
1086         struct dt_device        *d;
1087         struct thandle          *th;
1088         int                      rc;
1089
1090         ENTRY;
1091
1092         rc = llog_open(env, ctxt, res, logid, name, LLOG_OPEN_NEW);
1093         if (rc)
1094                 RETURN(rc);
1095
1096         if (llog_exist(*res))
1097                 RETURN(0);
1098
1099         LASSERT((*res)->lgh_obj != NULL);
1100
1101         d = lu2dt_dev((*res)->lgh_obj->do_lu.lo_dev);
1102
1103         th = dt_trans_create(env, d);
1104         if (IS_ERR(th))
1105                 GOTO(out, rc = PTR_ERR(th));
1106
1107         /* Create update llog object synchronously, which
1108          * happens during inialization process see
1109          * lod_sub_prep_llog(), to make sure the update
1110          * llog object is created before corss-MDT writing
1111          * updates into the llog object */
1112         if (ctxt->loc_flags & LLOG_CTXT_FLAG_NORMAL_FID)
1113                 th->th_sync = 1;
1114
1115         th->th_wait_submit = 1;
1116         rc = llog_declare_create(env, *res, th);
1117         if (rc == 0) {
1118                 rc = dt_trans_start_local(env, d, th);
1119                 if (rc == 0)
1120                         rc = llog_create(env, *res, th);
1121         }
1122         dt_trans_stop(env, d, th);
1123 out:
1124         if (rc)
1125                 llog_close(env, *res);
1126         RETURN(rc);
1127 }
1128 EXPORT_SYMBOL(llog_open_create);
1129
1130 /**
1131  * Helper function to delete existent llog.
1132  */
1133 int llog_erase(const struct lu_env *env, struct llog_ctxt *ctxt,
1134                struct llog_logid *logid, char *name)
1135 {
1136         struct llog_handle      *handle;
1137         int                      rc = 0, rc2;
1138
1139         ENTRY;
1140
1141         /* nothing to erase */
1142         if (name == NULL && logid == NULL)
1143                 RETURN(0);
1144
1145         rc = llog_open(env, ctxt, &handle, logid, name, LLOG_OPEN_EXISTS);
1146         if (rc < 0)
1147                 RETURN(rc);
1148
1149         rc = llog_init_handle(env, handle, LLOG_F_IS_PLAIN, NULL);
1150         if (rc == 0)
1151                 rc = llog_destroy(env, handle);
1152
1153         rc2 = llog_close(env, handle);
1154         if (rc == 0)
1155                 rc = rc2;
1156         RETURN(rc);
1157 }
1158 EXPORT_SYMBOL(llog_erase);
1159
1160 /*
1161  * Helper function for write record in llog.
1162  * It hides all transaction handling from caller.
1163  * Valid only with local llog.
1164  */
1165 int llog_write(const struct lu_env *env, struct llog_handle *loghandle,
1166                struct llog_rec_hdr *rec, int idx)
1167 {
1168         struct dt_device        *dt;
1169         struct thandle          *th;
1170         bool                    need_cookie;
1171         int                     rc;
1172
1173         ENTRY;
1174
1175         LASSERT(loghandle);
1176         LASSERT(loghandle->lgh_ctxt);
1177         LASSERT(loghandle->lgh_obj != NULL);
1178
1179         dt = lu2dt_dev(loghandle->lgh_obj->do_lu.lo_dev);
1180
1181         th = dt_trans_create(env, dt);
1182         if (IS_ERR(th))
1183                 RETURN(PTR_ERR(th));
1184
1185         rc = llog_declare_write_rec(env, loghandle, rec, idx, th);
1186         if (rc)
1187                 GOTO(out_trans, rc);
1188
1189         th->th_wait_submit = 1;
1190         rc = dt_trans_start_local(env, dt, th);
1191         if (rc)
1192                 GOTO(out_trans, rc);
1193
1194         need_cookie = !(idx == LLOG_HEADER_IDX || idx == LLOG_NEXT_IDX);
1195
1196         down_write(&loghandle->lgh_lock);
1197         if (need_cookie) {
1198                 struct llog_thread_info *lti = llog_info(env);
1199
1200                 /* cookie comes from llog_process_thread */
1201                 rc = llog_write_rec(env, loghandle, rec, &lti->lgi_cookie,
1202                                     rec->lrh_index, th);
1203                 /* upper layer didn`t pass cookie so change rc */
1204                 rc = (rc == 1 ? 0 : rc);
1205         } else {
1206                 rc = llog_write_rec(env, loghandle, rec, NULL, idx, th);
1207         }
1208
1209         up_write(&loghandle->lgh_lock);
1210 out_trans:
1211         dt_trans_stop(env, dt, th);
1212         RETURN(rc);
1213 }
1214 EXPORT_SYMBOL(llog_write);
1215
1216 int llog_open(const struct lu_env *env, struct llog_ctxt *ctxt,
1217               struct llog_handle **lgh, struct llog_logid *logid,
1218               char *name, enum llog_open_param open_param)
1219 {
1220         int      raised;
1221         int      rc;
1222
1223         ENTRY;
1224
1225         LASSERT(ctxt);
1226         LASSERT(ctxt->loc_logops);
1227
1228         if (ctxt->loc_logops->lop_open == NULL) {
1229                 *lgh = NULL;
1230                 RETURN(-EOPNOTSUPP);
1231         }
1232
1233         *lgh = llog_alloc_handle();
1234         if (*lgh == NULL)
1235                 RETURN(-ENOMEM);
1236         (*lgh)->lgh_ctxt = ctxt;
1237         (*lgh)->lgh_logops = ctxt->loc_logops;
1238
1239         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
1240         if (!raised)
1241                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
1242         rc = ctxt->loc_logops->lop_open(env, *lgh, logid, name, open_param);
1243         if (!raised)
1244                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
1245         if (rc) {
1246                 llog_free_handle(*lgh);
1247                 *lgh = NULL;
1248         }
1249         RETURN(rc);
1250 }
1251 EXPORT_SYMBOL(llog_open);
1252
1253 int llog_close(const struct lu_env *env, struct llog_handle *loghandle)
1254 {
1255         struct llog_operations  *lop;
1256         int                      rc;
1257
1258         ENTRY;
1259
1260         rc = llog_handle2ops(loghandle, &lop);
1261         if (rc)
1262                 GOTO(out, rc);
1263         if (lop->lop_close == NULL)
1264                 GOTO(out, rc = -EOPNOTSUPP);
1265         rc = lop->lop_close(env, loghandle);
1266 out:
1267         llog_handle_put(loghandle);
1268         RETURN(rc);
1269 }
1270 EXPORT_SYMBOL(llog_close);
1271
1272 /**
1273  * Helper function to get the llog size in records. It is used by MGS
1274  * mostly to check that config llog exists and contains data.
1275  *
1276  * \param[in] env       execution environment
1277  * \param[in] ctxt      llog context
1278  * \param[in] name      llog name
1279  *
1280  * \retval              true if there are records in llog besides a header
1281  * \retval              false on error or llog without records
1282  */
1283 int llog_is_empty(const struct lu_env *env, struct llog_ctxt *ctxt,
1284                   char *name)
1285 {
1286         struct llog_handle      *llh;
1287         int                      rc = 0;
1288
1289         rc = llog_open(env, ctxt, &llh, NULL, name, LLOG_OPEN_EXISTS);
1290         if (rc < 0) {
1291                 if (likely(rc == -ENOENT))
1292                         rc = 0;
1293                 GOTO(out, rc);
1294         }
1295
1296         rc = llog_init_handle(env, llh, LLOG_F_IS_PLAIN, NULL);
1297         if (rc)
1298                 GOTO(out_close, rc);
1299         rc = llog_get_size(llh);
1300
1301 out_close:
1302         llog_close(env, llh);
1303 out:
1304         /* The header is record 1, the llog is still considered as empty
1305          * if there is only header */
1306         return (rc <= 1);
1307 }
1308 EXPORT_SYMBOL(llog_is_empty);
1309
1310 int llog_copy_handler(const struct lu_env *env, struct llog_handle *llh,
1311                       struct llog_rec_hdr *rec, void *data)
1312 {
1313         struct llog_handle      *copy_llh = data;
1314
1315         /* Append all records */
1316         return llog_write(env, copy_llh, rec, LLOG_NEXT_IDX);
1317 }
1318
1319 /* backup plain llog */
1320 int llog_backup(const struct lu_env *env, struct obd_device *obd,
1321                 struct llog_ctxt *ctxt, struct llog_ctxt *bctxt,
1322                 char *name, char *backup)
1323 {
1324         struct llog_handle      *llh, *bllh;
1325         int                      rc;
1326
1327         ENTRY;
1328
1329         /* open original log */
1330         rc = llog_open(env, ctxt, &llh, NULL, name, LLOG_OPEN_EXISTS);
1331         if (rc < 0) {
1332                 /* the -ENOENT case is also reported to the caller
1333                  * but silently so it should handle that if needed.
1334                  */
1335                 if (rc != -ENOENT)
1336                         CERROR("%s: failed to open log %s: rc = %d\n",
1337                                obd->obd_name, name, rc);
1338                 RETURN(rc);
1339         }
1340
1341         rc = llog_init_handle(env, llh, LLOG_F_IS_PLAIN, NULL);
1342         if (rc)
1343                 GOTO(out_close, rc);
1344
1345         /* Make sure there's no old backup log */
1346         rc = llog_erase(env, bctxt, NULL, backup);
1347         if (rc < 0 && rc != -ENOENT)
1348                 GOTO(out_close, rc);
1349
1350         /* open backup log */
1351         rc = llog_open_create(env, bctxt, &bllh, NULL, backup);
1352         if (rc) {
1353                 CERROR("%s: failed to open backup logfile %s: rc = %d\n",
1354                        obd->obd_name, backup, rc);
1355                 GOTO(out_close, rc);
1356         }
1357
1358         /* check that backup llog is not the same object as original one */
1359         if (llh->lgh_obj == bllh->lgh_obj) {
1360                 CERROR("%s: backup llog %s to itself (%s), objects %p/%p\n",
1361                        obd->obd_name, name, backup, llh->lgh_obj,
1362                        bllh->lgh_obj);
1363                 GOTO(out_backup, rc = -EEXIST);
1364         }
1365
1366         rc = llog_init_handle(env, bllh, LLOG_F_IS_PLAIN, NULL);
1367         if (rc)
1368                 GOTO(out_backup, rc);
1369
1370         /* Copy log record by record */
1371         rc = llog_process_or_fork(env, llh, llog_copy_handler, (void *)bllh,
1372                                   NULL, false);
1373         if (rc)
1374                 CERROR("%s: failed to backup log %s: rc = %d\n",
1375                        obd->obd_name, name, rc);
1376 out_backup:
1377         llog_close(env, bllh);
1378 out_close:
1379         llog_close(env, llh);
1380         RETURN(rc);
1381 }
1382 EXPORT_SYMBOL(llog_backup);
1383
1384 /* Get size of llog */
1385 __u64 llog_size(const struct lu_env *env, struct llog_handle *llh)
1386 {
1387         int rc;
1388         struct lu_attr la;
1389
1390         rc = llh->lgh_obj->do_ops->do_attr_get(env, llh->lgh_obj, &la);
1391         if (rc) {
1392                 CERROR("%s: attr_get failed for "DFID": rc = %d\n",
1393                        llh->lgh_ctxt->loc_obd->obd_name,
1394                        PFID(&llh->lgh_id.lgl_oi.oi_fid), rc);
1395                 return 0;
1396         }
1397
1398         return la.la_size;
1399 }
1400 EXPORT_SYMBOL(llog_size);
1401