lustre/obdclass/llog.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * GPL HEADER START
   5  *
   6  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License version 2 for more details (a copy is included
  16  * in the LICENSE file that accompanied this code).
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * version 2 along with this program; If not, see [sun.com URL with a
  20  * copy of GPLv2].
  21  *
  22  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  23  * CA 95054 USA or visit www.sun.com if you need additional information or
  24  * have any questions.
  25  *
  26  * GPL HEADER END
  27  */
  28 /*
  29  * Copyright  2008 Sun Microsystems, Inc. All rights reserved
  30  * Use is subject to license terms.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  *
  36  * lustre/obdclass/llog.c
  37  *
  38  * OST<->MDS recovery logging infrastructure.
  39  * Invariants in implementation:
  40  * - we do not share logs among different OST<->MDS connections, so that
  41  *   if an OST or MDS fails it need only look at log(s) relevant to itself
  42  *
  43  * Author: Andreas Dilger <adilger@clusterfs.com>
  44  */
  45
  46 #define DEBUG_SUBSYSTEM S_LOG
  47
  48 #ifndef EXPORT_SYMTAB
  49 #define EXPORT_SYMTAB
  50 #endif
  51
  52 #ifndef __KERNEL__
  53 #include <liblustre.h>
  54 #endif
  55
  56 #include <obd_class.h>
  57 #include <lustre_log.h>
  58 #include <libcfs/list.h>
  59 #include "llog_internal.h"
  60
  61 /* Allocate a new log or catalog handle */
  62 struct llog_handle *llog_alloc_handle(void)
  63 {
  64         struct llog_handle *loghandle;
  65         ENTRY;
  66
  67         OBD_ALLOC(loghandle, sizeof(*loghandle));
  68         if (loghandle == NULL)
  69                 RETURN(ERR_PTR(-ENOMEM));
  70
  71         init_rwsem(&loghandle->lgh_lock);
  72
  73         RETURN(loghandle);
  74 }
  75 EXPORT_SYMBOL(llog_alloc_handle);
  76
  77
  78 void llog_free_handle(struct llog_handle *loghandle)
  79 {
  80         if (!loghandle)
  81                 return;
  82
  83         if (!loghandle->lgh_hdr)
  84                 goto out;
  85         if (loghandle->lgh_hdr->llh_flags & LLOG_F_IS_PLAIN)
  86                 list_del_init(&loghandle->u.phd.phd_entry);
  87         if (loghandle->lgh_hdr->llh_flags & LLOG_F_IS_CAT)
  88                 LASSERT(list_empty(&loghandle->u.chd.chd_head));
  89         OBD_FREE(loghandle->lgh_hdr, LLOG_CHUNK_SIZE);
  90
  91  out:
  92         OBD_FREE(loghandle, sizeof(*loghandle));
  93 }
  94 EXPORT_SYMBOL(llog_free_handle);
  95
  96 /* returns negative on error; 0 if success; 1 if success & log destroyed */
  97 int llog_cancel_rec(struct llog_handle *loghandle, int index)
  98 {
  99         struct llog_log_hdr *llh = loghandle->lgh_hdr;
 100         int rc = 0;
 101         ENTRY;
 102
 103         CDEBUG(D_RPCTRACE, "canceling %d in log "LPX64"\n",
 104                index, loghandle->lgh_id.lgl_oid);
 105
 106         if (index == 0) {
 107                 CERROR("cannot cancel index 0 (which is header)\n");
 108                 RETURN(-EINVAL);
 109         }
 110
 111         if (!ext2_clear_bit(index, llh->llh_bitmap)) {
 112                 CDEBUG(D_RPCTRACE, "catalog index %u already clear?\n", index);
 113                 RETURN(-EINVAL);
 114         }
 115
 116         llh->llh_count--;
 117
 118         if ((llh->llh_flags & LLOG_F_ZAP_WHEN_EMPTY) &&
 119             (llh->llh_count == 1) &&
 120             (loghandle->lgh_last_idx == (LLOG_BITMAP_BYTES * 8) - 1)) {
 121                 rc = llog_destroy(loghandle);
 122                 if (rc) {
 123                         CERROR("failure destroying log after last cancel: %d\n",
 124                                rc);
 125                         ext2_set_bit(index, llh->llh_bitmap);
 126                         llh->llh_count++;
 127                 } else {
 128                         rc = 1;
 129                 }
 130                 RETURN(rc);
 131         }
 132
 133         rc = llog_write_rec(loghandle, &llh->llh_hdr, NULL, 0, NULL, 0);
 134         if (rc) {
 135                 CERROR("failure re-writing header %d\n", rc);
 136                 ext2_set_bit(index, llh->llh_bitmap);
 137                 llh->llh_count++;
 138         }
 139         RETURN(rc);
 140 }
 141 EXPORT_SYMBOL(llog_cancel_rec);
 142
 143 int llog_init_handle(struct llog_handle *handle, int flags,
 144                      struct obd_uuid *uuid)
 145 {
 146         int rc;
 147         struct llog_log_hdr *llh;
 148         ENTRY;
 149         LASSERT(handle->lgh_hdr == NULL);
 150
 151         OBD_ALLOC(llh, sizeof(*llh));
 152         if (llh == NULL)
 153                 RETURN(-ENOMEM);
 154         handle->lgh_hdr = llh;
 155         /* first assign flags to use llog_client_ops */
 156         llh->llh_flags = flags;
 157         rc = llog_read_header(handle);
 158         if (rc == 0) {
 159                 flags = llh->llh_flags;
 160                 if (uuid && !obd_uuid_equals(uuid, &llh->llh_tgtuuid)) {
 161                         CERROR("uuid mismatch: %s/%s\n", (char *)uuid->uuid,
 162                                (char *)llh->llh_tgtuuid.uuid);
 163                         rc = -EEXIST;
 164                 }
 165                 GOTO(out, rc);
 166         } else if (rc != LLOG_EEMPTY || !flags) {
 167                 /* set a pesudo flag for initialization */
 168                 flags = LLOG_F_IS_CAT;
 169                 GOTO(out, rc);
 170         }
 171         rc = 0;
 172
 173         handle->lgh_last_idx = 0; /* header is record with index 0 */
 174         llh->llh_count = 1;         /* for the header record */
 175         llh->llh_hdr.lrh_type = LLOG_HDR_MAGIC;
 176         llh->llh_hdr.lrh_len = llh->llh_tail.lrt_len = LLOG_CHUNK_SIZE;
 177         llh->llh_hdr.lrh_index = llh->llh_tail.lrt_index = 0;
 178         llh->llh_timestamp = cfs_time_current_sec();
 179         if (uuid)
 180                 memcpy(&llh->llh_tgtuuid, uuid, sizeof(llh->llh_tgtuuid));
 181         llh->llh_bitmap_offset = offsetof(typeof(*llh),llh_bitmap);
 182         ext2_set_bit(0, llh->llh_bitmap);
 183
 184 out:
 185         if (flags & LLOG_F_IS_CAT) {
 186                 CFS_INIT_LIST_HEAD(&handle->u.chd.chd_head);
 187                 llh->llh_size = sizeof(struct llog_logid_rec);
 188         } else if (flags & LLOG_F_IS_PLAIN) {
 189                 CFS_INIT_LIST_HEAD(&handle->u.phd.phd_entry);
 190         } else {
 191                 CERROR("Unknown flags: %#x (Expected %#x or %#x\n",
 192                        flags, LLOG_F_IS_CAT, LLOG_F_IS_PLAIN);
 193                 LBUG();
 194         }
 195
 196         if (rc) {
 197                 OBD_FREE(llh, sizeof(*llh));
 198                 handle->lgh_hdr = NULL;
 199         }
 200         RETURN(rc);
 201 }
 202 EXPORT_SYMBOL(llog_init_handle);
 203
 204 int llog_close(struct llog_handle *loghandle)
 205 {
 206         struct llog_operations *lop;
 207         int rc;
 208         ENTRY;
 209
 210         rc = llog_handle2ops(loghandle, &lop);
 211         if (rc)
 212                 GOTO(out, rc);
 213         if (lop->lop_close == NULL)
 214                 GOTO(out, -EOPNOTSUPP);
 215         rc = lop->lop_close(loghandle);
 216  out:
 217         llog_free_handle(loghandle);
 218         RETURN(rc);
 219 }
 220 EXPORT_SYMBOL(llog_close);
 221
 222 static int llog_process_thread(void *arg)
 223 {
 224         struct llog_process_info     *lpi = (struct llog_process_info *)arg;
 225         struct llog_handle           *loghandle = lpi->lpi_loghandle;
 226         struct llog_log_hdr          *llh = loghandle->lgh_hdr;
 227         struct llog_process_cat_data *cd  = lpi->lpi_catdata;
 228         char                         *buf;
 229         __u64                         cur_offset = LLOG_CHUNK_SIZE;
 230         __u64                         last_offset;
 231         int                           rc = 0, index = 1, last_index;
 232         int                           saved_index = 0, last_called_index = 0;
 233
 234         LASSERT(llh);
 235
 236         OBD_ALLOC(buf, LLOG_CHUNK_SIZE);
 237         if (!buf) {
 238                 lpi->lpi_rc = -ENOMEM;
 239 #ifdef __KERNEL__
 240                 complete(&lpi->lpi_completion);
 241 #endif
 242                 return 0;
 243         }
 244
 245         cfs_daemonize_ctxt("llog_process_thread");
 246
 247         if (cd != NULL) {
 248                 last_called_index = cd->lpcd_first_idx;
 249                 index = cd->lpcd_first_idx + 1;
 250         }
 251         if (cd != NULL && cd->lpcd_last_idx)
 252                 last_index = cd->lpcd_last_idx;
 253         else
 254                 last_index = LLOG_BITMAP_BYTES * 8 - 1;
 255
 256         while (rc == 0) {
 257                 struct llog_rec_hdr *rec;
 258
 259                 /* skip records not set in bitmap */
 260                 while (index <= last_index &&
 261                        !ext2_test_bit(index, llh->llh_bitmap))
 262                         ++index;
 263
 264                 LASSERT(index <= last_index + 1);
 265                 if (index == last_index + 1)
 266                         break;
 267
 268                 CDEBUG(D_OTHER, "index: %d last_index %d\n",
 269                        index, last_index);
 270
 271                 /* get the buf with our target record; avoid old garbage */
 272                 memset(buf, 0, LLOG_CHUNK_SIZE);
 273                 last_offset = cur_offset;
 274                 rc = llog_next_block(loghandle, &saved_index, index,
 275                                      &cur_offset, buf, LLOG_CHUNK_SIZE);
 276                 if (rc)
 277                         GOTO(out, rc);
 278
 279                 /* NB: when rec->lrh_len is accessed it is already swabbed
 280                  * since it is used at the "end" of the loop and the rec
 281                  * swabbing is done at the beginning of the loop. */
 282                 for (rec = (struct llog_rec_hdr *)buf;
 283                      (char *)rec < buf + LLOG_CHUNK_SIZE;
 284                      rec = (struct llog_rec_hdr *)((char *)rec + rec->lrh_len)){
 285
 286                         CDEBUG(D_OTHER, "processing rec 0x%p type %#x\n",
 287                                rec, rec->lrh_type);
 288
 289                         if (LLOG_REC_HDR_NEEDS_SWABBING(rec))
 290                                 lustre_swab_llog_rec(rec, NULL);
 291
 292                         CDEBUG(D_OTHER, "after swabbing, type=%#x idx=%d\n",
 293                                rec->lrh_type, rec->lrh_index);
 294
 295                         if (rec->lrh_index == 0)
 296                                 GOTO(out, 0); /* no more records */
 297
 298                         if (rec->lrh_len == 0 || rec->lrh_len >LLOG_CHUNK_SIZE){
 299                                 CWARN("invalid length %d in llog record for "
 300                                       "index %d/%d\n", rec->lrh_len,
 301                                       rec->lrh_index, index);
 302                                 GOTO(out, rc = -EINVAL);
 303                         }
 304
 305                         if (rec->lrh_index < index) {
 306                                 CDEBUG(D_OTHER, "skipping lrh_index %d\n",
 307                                        rec->lrh_index);
 308                                 continue;
 309                         }
 310
 311                         CDEBUG(D_OTHER,
 312                                "lrh_index: %d lrh_len: %d (%d remains)\n",
 313                                rec->lrh_index, rec->lrh_len,
 314                                (int)(buf + LLOG_CHUNK_SIZE - (char *)rec));
 315
 316                         loghandle->lgh_cur_idx = rec->lrh_index;
 317                         loghandle->lgh_cur_offset = (char *)rec - (char *)buf +
 318                                                     last_offset;
 319
 320                         /* if set, process the callback on this record */
 321                         if (ext2_test_bit(index, llh->llh_bitmap)) {
 322                                 rc = lpi->lpi_cb(loghandle, rec,
 323                                                  lpi->lpi_cbdata);
 324                                 last_called_index = index;
 325                                 if (rc == LLOG_PROC_BREAK) {
 326                                         CDEBUG(D_HA, "recovery from log: "LPX64
 327                                                ":%x stopped\n",
 328                                                loghandle->lgh_id.lgl_oid,
 329                                                loghandle->lgh_id.lgl_ogen);
 330                                         GOTO(out, rc);
 331                                 } else if (rc == LLOG_DEL_RECORD) {
 332                                         llog_cancel_rec(loghandle,
 333                                                         rec->lrh_index);
 334                                         rc = 0;
 335                                 }
 336                                 if (rc)
 337                                         GOTO(out, rc);
 338                         } else {
 339                                 CDEBUG(D_OTHER, "Skipped index %d\n", index);
 340                         }
 341
 342                         /* next record, still in buffer? */
 343                         ++index;
 344                         if (index > last_index)
 345                                 GOTO(out, rc = 0);
 346                 }
 347         }
 348
 349  out:
 350         if (cd != NULL)
 351                 cd->lpcd_last_idx = last_called_index;
 352         if (buf)
 353                 OBD_FREE(buf, LLOG_CHUNK_SIZE);
 354         lpi->lpi_rc = rc;
 355 #ifdef __KERNEL__
 356         complete(&lpi->lpi_completion);
 357 #endif
 358         return 0;
 359 }
 360
 361 int llog_process(struct llog_handle *loghandle, llog_cb_t cb,
 362                  void *data, void *catdata)
 363 {
 364         struct llog_process_info *lpi;
 365         int                      rc;
 366         ENTRY;
 367
 368         OBD_ALLOC_PTR(lpi);
 369         if (lpi == NULL) {
 370                 CERROR("cannot alloc pointer\n");
 371                 RETURN(-ENOMEM);
 372         }
 373         lpi->lpi_loghandle = loghandle;
 374         lpi->lpi_cb        = cb;
 375         lpi->lpi_cbdata    = data;
 376         lpi->lpi_catdata   = catdata;
 377
 378 #ifdef __KERNEL__
 379         init_completion(&lpi->lpi_completion);
 380         rc = cfs_kernel_thread(llog_process_thread, lpi, CLONE_VM | CLONE_FILES);
 381         if (rc < 0) {
 382                 CERROR("cannot start thread: %d\n", rc);
 383                 OBD_FREE_PTR(lpi);
 384                 RETURN(rc);
 385         }
 386         wait_for_completion(&lpi->lpi_completion);
 387 #else
 388         llog_process_thread(lpi);
 389 #endif
 390         rc = lpi->lpi_rc;
 391         OBD_FREE_PTR(lpi);
 392         RETURN(rc);
 393 }
 394 EXPORT_SYMBOL(llog_process);
 395
 396 inline int llog_get_size(struct llog_handle *loghandle)
 397 {
 398         if (loghandle && loghandle->lgh_hdr)
 399                 return loghandle->lgh_hdr->llh_count;
 400         return 0;
 401 }
 402 EXPORT_SYMBOL(llog_get_size);
 403
 404 int llog_reverse_process(struct llog_handle *loghandle, llog_cb_t cb,
 405                          void *data, void *catdata)
 406 {
 407         struct llog_log_hdr *llh = loghandle->lgh_hdr;
 408         struct llog_process_cat_data *cd = catdata;
 409         void *buf;
 410         int rc = 0, first_index = 1, index, idx;
 411         ENTRY;
 412
 413         OBD_ALLOC(buf, LLOG_CHUNK_SIZE);
 414         if (!buf)
 415                 RETURN(-ENOMEM);
 416
 417         if (cd != NULL)
 418                 first_index = cd->lpcd_first_idx + 1;
 419         if (cd != NULL && cd->lpcd_last_idx)
 420                 index = cd->lpcd_last_idx;
 421         else
 422                 index = LLOG_BITMAP_BYTES * 8 - 1;
 423
 424         while (rc == 0) {
 425                 struct llog_rec_hdr *rec;
 426                 struct llog_rec_tail *tail;
 427
 428                 /* skip records not set in bitmap */
 429                 while (index >= first_index &&
 430                        !ext2_test_bit(index, llh->llh_bitmap))
 431                         --index;
 432
 433                 LASSERT(index >= first_index - 1);
 434                 if (index == first_index - 1)
 435                         break;
 436
 437                 /* get the buf with our target record; avoid old garbage */
 438                 memset(buf, 0, LLOG_CHUNK_SIZE);
 439                 rc = llog_prev_block(loghandle, index, buf, LLOG_CHUNK_SIZE);
 440                 if (rc)
 441                         GOTO(out, rc);
 442
 443                 rec = buf;
 444                 idx = le32_to_cpu(rec->lrh_index);
 445                 if (idx < index)
 446                         CDEBUG(D_RPCTRACE, "index %u : idx %u\n", index, idx);
 447                 while (idx < index) {
 448                         rec = ((void *)rec + le32_to_cpu(rec->lrh_len));
 449                         idx ++;
 450                 }
 451                 tail = (void *)rec + le32_to_cpu(rec->lrh_len) - sizeof(*tail);
 452
 453                 /* process records in buffer, starting where we found one */
 454                 while ((void *)tail > buf) {
 455                         rec = (void *)tail - le32_to_cpu(tail->lrt_len) +
 456                                 sizeof(*tail);
 457
 458                         if (rec->lrh_index == 0)
 459                                 GOTO(out, 0); /* no more records */
 460
 461                         /* if set, process the callback on this record */
 462                         if (ext2_test_bit(index, llh->llh_bitmap)) {
 463                                 rc = cb(loghandle, rec, data);
 464                                 if (rc == LLOG_PROC_BREAK) {
 465                                         CWARN("recovery from log: "LPX64":%x"
 466                                               " stopped\n",
 467                                               loghandle->lgh_id.lgl_oid,
 468                                               loghandle->lgh_id.lgl_ogen);
 469                                         GOTO(out, rc);
 470                                 }
 471                                 if (rc)
 472                                         GOTO(out, rc);
 473                         }
 474
 475                         /* previous record, still in buffer? */
 476                         --index;
 477                         if (index < first_index)
 478                                 GOTO(out, rc = 0);
 479                         tail = (void *)rec - sizeof(*tail);
 480                 }
 481         }
 482
 483 out:
 484         if (buf)
 485                 OBD_FREE(buf, LLOG_CHUNK_SIZE);
 486         RETURN(rc);
 487 }
 488 EXPORT_SYMBOL(llog_reverse_process);