lustre/obdclass/llog_cat.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  *  Copyright (C) 2001-2003 Cluster File Systems, Inc.
   5  *   Author: Andreas Dilger <adilger@clusterfs.com>
   6  *
   7  *   This file is part of Lustre, http://www.lustre.org.
   8  *
   9  *   Lustre is free software; you can redistribute it and/or
  10  *   modify it under the terms of version 2 of the GNU General Public
  11  *   License as published by the Free Software Foundation.
  12  *
  13  *   Lustre is distributed in the hope that it will be useful,
  14  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *   GNU General Public License for more details.
  17  *
  18  *   You should have received a copy of the GNU General Public License
  19  *   along with Lustre; if not, write to the Free Software
  20  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21  *
  22  * OST<->MDS recovery logging infrastructure.
  23  *
  24  * Invariants in implementation:
  25  * - we do not share logs among different OST<->MDS connections, so that
  26  *   if an OST or MDS fails it need only look at log(s) relevant to itself
  27  */
  28
  29 #define DEBUG_SUBSYSTEM S_LOG
  30
  31 #ifndef EXPORT_SYMTAB
  32 #define EXPORT_SYMTAB
  33 #endif
  34
  35 #ifdef __KERNEL__
  36 #include <linux/fs.h>
  37 #else
  38 #include <liblustre.h>
  39 #endif
  40
  41 #include <linux/obd_class.h>
  42 #include <linux/lustre_log.h>
  43 #include <portals/list.h>
  44
  45 /* Create a new log handle and add it to the open list.
  46  * This log handle will be closed when all of the records in it are removed.
  47  *
  48  * Assumes caller has already pushed us into the kernel context and is locking.
  49  */
  50 static struct llog_handle *llog_cat_new_log(struct llog_handle *cathandle)
  51 {
  52         struct llog_handle *loghandle;
  53         struct llog_log_hdr *llh;
  54         struct llog_logid_rec rec = { { 0 }, };
  55         int rc, index, bitmap_size;
  56         ENTRY;
  57
  58         llh = cathandle->lgh_hdr;
  59         bitmap_size = LLOG_BITMAP_SIZE(llh);
  60
  61         index = (cathandle->lgh_last_idx + 1) % bitmap_size;
  62
  63         /* maximum number of available slots in catlog is bitmap_size - 2 */
  64         if (llh->llh_cat_idx == index) {
  65                 CERROR("no free catalog slots for log...\n");
  66                 RETURN(ERR_PTR(-ENOSPC));
  67         } else {
  68                 if (index == 0)
  69                         index = 1;
  70                 if (ext2_set_bit(index, llh->llh_bitmap)) {
  71                         CERROR("argh, index %u already set in log bitmap?\n",
  72                                index);
  73                         LBUG(); /* should never happen */
  74                 }
  75                 cathandle->lgh_last_idx = index;
  76                 llh->llh_count++;
  77                 llh->llh_tail.lrt_index = index;
  78         }
  79
  80         rc = llog_create(cathandle->lgh_ctxt, &loghandle, NULL, NULL);
  81         if (rc)
  82                 RETURN(ERR_PTR(rc));
  83
  84         rc = llog_init_handle(loghandle,
  85                               LLOG_F_IS_PLAIN | LLOG_F_ZAP_WHEN_EMPTY,
  86                               &cathandle->lgh_hdr->llh_tgtuuid);
  87         if (rc)
  88                 GOTO(out_destroy, rc);
  89
  90         CDEBUG(D_HA, "new recovery log "LPX64":%x for index %u of catalog "
  91                LPX64"\n", loghandle->lgh_id.lgl_oid, loghandle->lgh_id.lgl_ogen,
  92                index, cathandle->lgh_id.lgl_oid);
  93         /* build the record for this log in the catalog */
  94         rec.lid_hdr.lrh_len = sizeof(rec);
  95         rec.lid_hdr.lrh_index = index;
  96         rec.lid_hdr.lrh_type = LLOG_LOGID_MAGIC;
  97         rec.lid_id = loghandle->lgh_id;
  98         rec.lid_tail.lrt_len = sizeof(rec);
  99         rec.lid_tail.lrt_index = index;
 100
 101         /* update the catalog: header and record */
 102         rc = llog_write_rec(cathandle, &rec.lid_hdr,
 103                             &loghandle->u.phd.phd_cookie, 1, NULL, index);
 104         if (rc < 0) {
 105                 GOTO(out_destroy, rc);
 106         }
 107
 108         loghandle->lgh_hdr->llh_cat_idx = index;
 109         cathandle->u.chd.chd_current_log = loghandle;
 110         LASSERT(list_empty(&loghandle->u.phd.phd_entry));
 111         list_add_tail(&loghandle->u.phd.phd_entry, &cathandle->u.chd.chd_head);
 112
 113  out_destroy:
 114         if (rc < 0)
 115                 llog_destroy(loghandle);
 116
 117         RETURN(loghandle);
 118 }
 119 EXPORT_SYMBOL(llog_cat_new_log);
 120
 121 /* Open an existent log handle and add it to the open list.
 122  * This log handle will be closed when all of the records in it are removed.
 123  *
 124  * Assumes caller has already pushed us into the kernel context and is locking.
 125  * We return a lock on the handle to ensure nobody yanks it from us.
 126  */
 127 int llog_cat_id2handle(struct llog_handle *cathandle, struct llog_handle **res,
 128                        struct llog_logid *logid)
 129 {
 130         struct llog_handle *loghandle;
 131         int rc = 0;
 132         ENTRY;
 133
 134         if (cathandle == NULL)
 135                 RETURN(-EBADF);
 136
 137         list_for_each_entry(loghandle, &cathandle->u.chd.chd_head,
 138                             u.phd.phd_entry) {
 139                 struct llog_logid *cgl = &loghandle->lgh_id;
 140                 if (cgl->lgl_oid == logid->lgl_oid) {
 141                         if (cgl->lgl_ogen != logid->lgl_ogen) {
 142                                 CERROR("log "LPX64" generation %x != %x\n",
 143                                        logid->lgl_oid, cgl->lgl_ogen,
 144                                        logid->lgl_ogen);
 145                                 continue;
 146                         }
 147                         loghandle->u.phd.phd_cat_handle = cathandle;
 148                         GOTO(out, rc = 0);
 149                 }
 150         }
 151
 152         rc = llog_create(cathandle->lgh_ctxt, &loghandle, logid, NULL);
 153         if (rc) {
 154                 CERROR("error opening log id "LPX64":%x: rc %d\n",
 155                        logid->lgl_oid, logid->lgl_ogen, rc);
 156         } else {
 157                 rc = llog_init_handle(loghandle, LLOG_F_IS_PLAIN, NULL);
 158                 if (!rc) {
 159                         list_add(&loghandle->u.phd.phd_entry,
 160                                  &cathandle->u.chd.chd_head);
 161                 }
 162         }
 163         if (!rc) {
 164                 loghandle->u.phd.phd_cat_handle = cathandle;
 165                 loghandle->u.phd.phd_cookie.lgc_lgl = cathandle->lgh_id;
 166                 loghandle->u.phd.phd_cookie.lgc_index =
 167                         loghandle->lgh_hdr->llh_cat_idx;
 168         }
 169
 170 out:
 171         *res = loghandle;
 172         RETURN(rc);
 173 }
 174
 175 int llog_cat_put(struct llog_handle *cathandle)
 176 {
 177         struct llog_handle *loghandle, *n;
 178         int rc;
 179         ENTRY;
 180
 181         list_for_each_entry_safe(loghandle, n, &cathandle->u.chd.chd_head,
 182                                  u.phd.phd_entry) {
 183                 int err = llog_close(loghandle);
 184                 if (err)
 185                         CERROR("error closing loghandle\n");
 186         }
 187         rc = llog_close(cathandle);
 188         RETURN(rc);
 189 }
 190 EXPORT_SYMBOL(llog_cat_put);
 191
 192 /* Return the currently active log handle.  If the current log handle doesn't
 193  * have enough space left for the current record, start a new one.
 194  *
 195  * If reclen is 0, we only want to know what the currently active log is,
 196  * otherwise we get a lock on this log so nobody can steal our space.
 197  *
 198  * Assumes caller has already pushed us into the kernel context and is locking.
 199  *
 200  * NOTE: loghandle is write-locked upon successful return
 201  */
 202 static struct llog_handle *llog_cat_current_log(struct llog_handle *cathandle,
 203                                                 int create)
 204 {
 205         struct llog_handle *loghandle = NULL;
 206         ENTRY;
 207
 208         down_read(&cathandle->lgh_lock);
 209         loghandle = cathandle->u.chd.chd_current_log;
 210         if (loghandle) {
 211                 struct llog_log_hdr *llh = loghandle->lgh_hdr;
 212                 down_write(&loghandle->lgh_lock);
 213                 if (loghandle->lgh_last_idx < LLOG_BITMAP_SIZE(llh) - 1) {
 214                         up_read(&cathandle->lgh_lock);
 215                         RETURN(loghandle);
 216                 } else {
 217                         up_write(&loghandle->lgh_lock);
 218                 }
 219         }
 220         if (!create) {
 221                 if (loghandle)
 222                         down_write(&loghandle->lgh_lock);
 223                 up_read(&cathandle->lgh_lock);
 224                 RETURN(loghandle);
 225         }
 226         up_read(&cathandle->lgh_lock);
 227
 228         /* time to create new log */
 229
 230         /* first, we have to make sure the state hasn't changed */
 231         down_write(&cathandle->lgh_lock);
 232         loghandle = cathandle->u.chd.chd_current_log;
 233         if (loghandle) {
 234                 struct llog_log_hdr *llh = loghandle->lgh_hdr;
 235                 down_write(&loghandle->lgh_lock);
 236                 if (loghandle->lgh_last_idx < LLOG_BITMAP_SIZE(llh) - 1) {
 237                         up_write(&cathandle->lgh_lock);
 238                         RETURN(loghandle);
 239                 } else {
 240                         up_write(&loghandle->lgh_lock);
 241                 }
 242         }
 243
 244         CDEBUG(D_INODE, "creating new log\n");
 245         loghandle = llog_cat_new_log(cathandle);
 246         if (!IS_ERR(loghandle))
 247                 down_write(&loghandle->lgh_lock);
 248         up_write(&cathandle->lgh_lock);
 249         RETURN(loghandle);
 250 }
 251
 252 /* Add a single record to the recovery log(s) using a catalog
 253  * Returns as llog_write_record
 254  *
 255  * Assumes caller has already pushed us into the kernel context.
 256  */
 257 int llog_cat_add_rec(struct llog_handle *cathandle, struct llog_rec_hdr *rec,
 258                      struct llog_cookie *reccookie, void *buf)
 259 {
 260         struct llog_handle *loghandle;
 261         int rc;
 262         ENTRY;
 263
 264         LASSERT(rec->lrh_len <= LLOG_CHUNK_SIZE);
 265         loghandle = llog_cat_current_log(cathandle, 1);
 266         if (IS_ERR(loghandle))
 267                 RETURN(PTR_ERR(loghandle));
 268         /* loghandle is already locked by llog_cat_current_log() for us */
 269         rc = llog_write_rec(loghandle, rec, reccookie, 1, buf, -1);
 270         up_write(&loghandle->lgh_lock);
 271         if (rc == -ENOSPC) {
 272                 /* to create a new plain log */
 273                 loghandle = llog_cat_current_log(cathandle, 1);
 274                 if (IS_ERR(loghandle))
 275                         RETURN(PTR_ERR(loghandle));
 276                 rc = llog_write_rec(loghandle, rec, reccookie, 1, buf, -1);
 277                 up_write(&loghandle->lgh_lock);
 278         }
 279
 280         RETURN(rc);
 281 }
 282 EXPORT_SYMBOL(llog_cat_add_rec);
 283
 284 /* For each cookie in the cookie array, we clear the log in-use bit and either:
 285  * - the log is empty, so mark it free in the catalog header and delete it
 286  * - the log is not empty, just write out the log header
 287  *
 288  * The cookies may be in different log files, so we need to get new logs
 289  * each time.
 290  *
 291  * Assumes caller has already pushed us into the kernel context.
 292  */
 293 int llog_cat_cancel_records(struct llog_handle *cathandle, int count,
 294                         struct llog_cookie *cookies)
 295 {
 296         int i, index, rc = 0;
 297         ENTRY;
 298
 299         down_write(&cathandle->lgh_lock);
 300         for (i = 0; i < count; i++, cookies++) {
 301                 struct llog_handle *loghandle;
 302                 struct llog_logid *lgl = &cookies->lgc_lgl;
 303
 304                 rc = llog_cat_id2handle(cathandle, &loghandle, lgl);
 305                 if (rc) {
 306                         CERROR("Cannot find log "LPX64"\n", lgl->lgl_oid);
 307                         break;
 308                 }
 309
 310                 down_write(&loghandle->lgh_lock);
 311                 rc = llog_cancel_rec(loghandle, cookies->lgc_index);
 312                 up_write(&loghandle->lgh_lock);
 313
 314                 if (rc == 1) {          /* log has been destroyed */
 315                         index = loghandle->u.phd.phd_cookie.lgc_index;
 316                         if (cathandle->u.chd.chd_current_log == loghandle)
 317                                 cathandle->u.chd.chd_current_log = NULL;
 318                         llog_free_handle(loghandle);
 319
 320                         LASSERT(index);
 321                         llog_cat_set_first_idx(cathandle, index);
 322                         rc = llog_cancel_rec(cathandle, index);
 323                         if (rc == 0)
 324                                 CDEBUG(D_HA, "cancel plain log at index %u "
 325                                        "of catalog "LPX64"\n",
 326                                        index, cathandle->lgh_id.lgl_oid);
 327                 }
 328         }
 329         up_write(&cathandle->lgh_lock);
 330
 331         RETURN(rc);
 332 }
 333 EXPORT_SYMBOL(llog_cat_cancel_records);
 334
 335 int llog_cat_process_cb(struct llog_handle *cat_llh, struct llog_rec_hdr *rec,
 336                         void *data)
 337 {
 338         struct llog_process_data *d = data;
 339         struct llog_logid_rec *lir = (struct llog_logid_rec *)rec;
 340         struct llog_handle *llh;
 341         int rc;
 342
 343         if (rec->lrh_type != LLOG_LOGID_MAGIC) {
 344                 CERROR("invalid record in catalog\n");
 345                 RETURN(-EINVAL);
 346         }
 347         CWARN("processing log "LPX64":%x at index %u of catalog "LPX64"\n",
 348                lir->lid_id.lgl_oid, lir->lid_id.lgl_ogen,
 349                rec->lrh_index, cat_llh->lgh_id.lgl_oid);
 350
 351         rc = llog_cat_id2handle(cat_llh, &llh, &lir->lid_id);
 352         if (rc) {
 353                 CERROR("Cannot find handle for log "LPX64"\n",
 354                        lir->lid_id.lgl_oid);
 355                 RETURN(rc);
 356         }
 357
 358         rc = llog_process(llh, d->lpd_cb, d->lpd_data, NULL);
 359         RETURN(rc);
 360 }
 361
 362 int llog_cat_process(struct llog_handle *cat_llh, llog_cb_t cb, void *data)
 363 {
 364         struct llog_process_data d;
 365         struct llog_process_cat_data cd;
 366         struct llog_log_hdr *llh = cat_llh->lgh_hdr;
 367         int rc;
 368         ENTRY;
 369
 370         LASSERT(llh->llh_flags & LLOG_F_IS_CAT);
 371         d.lpd_data = data;
 372         d.lpd_cb = cb;
 373
 374         if (llh->llh_cat_idx > cat_llh->lgh_last_idx) {
 375                 CWARN("catlog "LPX64" crosses index zero\n",
 376                       cat_llh->lgh_id.lgl_oid);
 377
 378                 cd.first_idx = llh->llh_cat_idx;
 379                 cd.last_idx = 0;
 380                 rc = llog_process(cat_llh, llog_cat_process_cb, &d, &cd);
 381                 if (rc != 0)
 382                         RETURN(rc);
 383
 384                 cd.first_idx = 0;
 385                 cd.last_idx = cat_llh->lgh_last_idx;
 386                 rc = llog_process(cat_llh, llog_cat_process_cb, &d, &cd);
 387         } else {
 388                 rc = llog_process(cat_llh, llog_cat_process_cb, &d, NULL);
 389         }
 390
 391         RETURN(rc);
 392 }
 393 EXPORT_SYMBOL(llog_cat_process);
 394
 395 int llog_cat_set_first_idx(struct llog_handle *cathandle, int index)
 396 {
 397         struct llog_log_hdr *llh = cathandle->lgh_hdr;
 398         int i, bitmap_size, idx;
 399         ENTRY;
 400
 401         bitmap_size = LLOG_BITMAP_SIZE(llh);
 402         if (llh->llh_cat_idx == (index - 1)) {
 403                 idx = llh->llh_cat_idx + 1;
 404                 llh->llh_cat_idx = idx;
 405                 if (idx == cathandle->lgh_last_idx)
 406                         goto out;
 407                 for (i = (index + 1) % bitmap_size;
 408                      i != cathandle->lgh_last_idx;
 409                      i = (i + 1) % bitmap_size) {
 410                         if (!ext2_test_bit(i, llh->llh_bitmap)) {
 411                                 idx = llh->llh_cat_idx + 1;
 412                                 llh->llh_cat_idx = idx;
 413                         } else if (i == 0) {
 414                                 llh->llh_cat_idx = 0;
 415                         } else {
 416                                 break;
 417                         }
 418                 }
 419 out:
 420                 CDEBUG(D_HA, "set catlog "LPX64" first idx %u\n",
 421                        cathandle->lgh_id.lgl_oid, llh->llh_cat_idx);
 422         }
 423
 424         RETURN(0);
 425 }
 426
 427 #if 0
 428 /* Assumes caller has already pushed us into the kernel context. */
 429 int llog_cat_init(struct llog_handle *cathandle, struct obd_uuid *tgtuuid)
 430 {
 431         struct llog_log_hdr *llh;
 432         loff_t offset = 0;
 433         int rc = 0;
 434         ENTRY;
 435
 436         LASSERT(sizeof(*llh) == LLOG_CHUNK_SIZE);
 437
 438         down(&cathandle->lgh_lock);
 439         llh = cathandle->lgh_hdr;
 440
 441         if (cathandle->lgh_file->f_dentry->d_inode->i_size == 0) {
 442                 llog_write_rec(cathandle, &llh->llh_hdr, NULL, 0, NULL, 0);
 443
 444 write_hdr:
 445                 rc = lustre_fwrite(cathandle->lgh_file, llh, LLOG_CHUNK_SIZE,
 446                                    &offset);
 447                 if (rc != LLOG_CHUNK_SIZE) {
 448                         CERROR("error writing catalog header: rc %d\n", rc);
 449                         OBD_FREE(llh, sizeof(*llh));
 450                         if (rc >= 0)
 451                                 rc = -ENOSPC;
 452                 } else
 453                         rc = 0;
 454         } else {
 455                 rc = lustre_fread(cathandle->lgh_file, llh, LLOG_CHUNK_SIZE,
 456                                   &offset);
 457                 if (rc != LLOG_CHUNK_SIZE) {
 458                         CERROR("error reading catalog header: rc %d\n", rc);
 459                         /* Can we do much else if the header is bad? */
 460                         goto write_hdr;
 461                 } else
 462                         rc = 0;
 463         }
 464
 465         cathandle->lgh_tgtuuid = &llh->llh_tgtuuid;
 466         up(&cathandle->lgh_lock);
 467         RETURN(rc);
 468 }
 469 EXPORT_SYMBOL(llog_cat_init);
 470
 471 #endif