lustre/lvfs/llog.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/lustre_log.h>
  42
  43 /* Allocate a new log or catalog handle */
  44 struct llog_handle *llog_alloc_handle(void)
  45 {
  46         struct llog_handle *loghandle;
  47         ENTRY;
  48
  49         OBD_ALLOC(loghandle, sizeof(*loghandle));
  50         if (loghandle == NULL)
  51                 RETURN(ERR_PTR(-ENOMEM));
  52
  53         init_rwsem(&loghandle->lgh_lock);
  54
  55         RETURN(loghandle);
  56 }
  57 EXPORT_SYMBOL(llog_alloc_handle);
  58
  59 void llog_free_handle(struct llog_handle *loghandle)
  60 {
  61         if (!loghandle)
  62                 return;
  63
  64         if (!loghandle->lgh_hdr)
  65                 goto out;
  66         if (le32_to_cpu(loghandle->lgh_hdr->llh_flags) & LLOG_F_IS_PLAIN)
  67                 list_del_init(&loghandle->u.phd.phd_entry);
  68         if (le32_to_cpu(loghandle->lgh_hdr->llh_flags) & LLOG_F_IS_CAT)
  69                 LASSERT(list_empty(&loghandle->u.chd.chd_head));
  70         OBD_FREE(loghandle->lgh_hdr, LLOG_CHUNK_SIZE);
  71
  72  out:
  73         OBD_FREE(loghandle, sizeof(*loghandle));
  74 }
  75 EXPORT_SYMBOL(llog_free_handle);
  76
  77 /* returns negative on error; 0 if success; 1 if success & log destroyed */
  78 int llog_cancel_rec(struct llog_handle *loghandle, int index)
  79 {
  80         struct llog_log_hdr *llh = loghandle->lgh_hdr;
  81         int rc = 0;
  82         ENTRY;
  83
  84         CDEBUG(D_HA, "canceling %d in log "LPX64"\n",
  85                index, loghandle->lgh_id.lgl_oid);
  86
  87         if (index == 0) {
  88                 CERROR("cannot cancel index 0 (which is header)\n");
  89                 RETURN(-EINVAL);
  90         }
  91
  92         if (!ext2_clear_bit(index, llh->llh_bitmap)) {
  93                 CERROR("catalog index %u already clear?\n", index);
  94                 RETURN(-EINVAL);
  95         }
  96
  97         llh->llh_count = cpu_to_le32(le32_to_cpu(llh->llh_count) - 1);
  98
  99         if ((le32_to_cpu(llh->llh_flags) & LLOG_F_ZAP_WHEN_EMPTY) &&
 100             (le32_to_cpu(llh->llh_count) == 1) &&
 101             (loghandle->lgh_last_idx == (LLOG_BITMAP_BYTES * 8) - 1)) {
 102                 rc = llog_destroy(loghandle);
 103                 if (rc)
 104                         CERROR("failure destroying log after last cancel: %d\n",
 105                                rc);
 106                 LASSERT(rc == 0);
 107                 RETURN(1);
 108         }
 109
 110         rc = llog_write_rec(loghandle, &llh->llh_hdr, NULL, 0, NULL, 0);
 111         if (rc)
 112                 CERROR("failure re-writing header %d\n", rc);
 113         LASSERT(rc == 0);
 114         RETURN(rc);
 115 }
 116 EXPORT_SYMBOL(llog_cancel_rec);
 117
 118 int llog_init_handle(struct llog_handle *handle, int flags,
 119                      struct obd_uuid *uuid)
 120 {
 121         int rc;
 122         struct llog_log_hdr *llh;
 123         ENTRY;
 124         LASSERT(handle->lgh_hdr == NULL);
 125
 126         OBD_ALLOC(llh, sizeof(*llh));
 127         if (llh == NULL)
 128                 RETURN(-ENOMEM);
 129         handle->lgh_hdr = llh;
 130         /* first assign flags to use llog_client_ops */
 131         llh->llh_flags = cpu_to_le32(flags);
 132         rc = llog_read_header(handle);
 133         if (rc == 0) {
 134                 flags = le32_to_cpu(llh->llh_flags);
 135                 if (uuid)
 136                         LASSERT(obd_uuid_equals(uuid, &llh->llh_tgtuuid));
 137                 GOTO(out, rc);
 138         } else if (rc != LLOG_EEMPTY || !flags) {
 139                 /* set a pesudo flag for initialization */
 140                 flags = LLOG_F_IS_CAT;
 141                 GOTO(out, rc);
 142         }
 143         rc = 0;
 144
 145         handle->lgh_last_idx = 0; /* header is record with index 0 */
 146         llh->llh_count = cpu_to_le32(1);         /* for the header record */
 147         llh->llh_hdr.lrh_type = cpu_to_le32(LLOG_HDR_MAGIC);
 148         llh->llh_hdr.lrh_len = llh->llh_tail.lrt_len =
 149                 cpu_to_le32(LLOG_CHUNK_SIZE);
 150         llh->llh_hdr.lrh_index = llh->llh_tail.lrt_index = 0;
 151         llh->llh_timestamp = cpu_to_le64(LTIME_S(CURRENT_TIME));
 152         if (uuid)
 153                 memcpy(&llh->llh_tgtuuid, uuid, sizeof(llh->llh_tgtuuid));
 154         llh->llh_bitmap_offset = cpu_to_le32(offsetof(typeof(*llh),llh_bitmap));
 155         ext2_set_bit(0, llh->llh_bitmap);
 156
 157 out:
 158         if (flags & LLOG_F_IS_CAT) {
 159                 INIT_LIST_HEAD(&handle->u.chd.chd_head);
 160                 llh->llh_size = cpu_to_le32(sizeof(struct llog_logid_rec));
 161         }
 162         else if (flags & LLOG_F_IS_PLAIN)
 163                 INIT_LIST_HEAD(&handle->u.phd.phd_entry);
 164         else
 165                 LBUG();
 166
 167         if (rc) {
 168                 OBD_FREE(llh, sizeof(*llh));
 169                 handle->lgh_hdr = NULL;
 170         }
 171         RETURN(rc);
 172 }
 173 EXPORT_SYMBOL(llog_init_handle);
 174
 175 int llog_close(struct llog_handle *loghandle)
 176 {
 177         struct llog_operations *lop;
 178         int rc;
 179         ENTRY;
 180
 181         rc = llog_handle2ops(loghandle, &lop);
 182         if (rc)
 183                 GOTO(out, rc);
 184         if (lop->lop_close == NULL)
 185                 GOTO(out, -EOPNOTSUPP);
 186         rc = lop->lop_close(loghandle);
 187  out:
 188         llog_free_handle(loghandle);
 189         RETURN(rc);
 190 }
 191 EXPORT_SYMBOL(llog_close);
 192
 193 int llog_process(struct llog_handle *loghandle, llog_cb_t cb,
 194                  void *data, void *catdata)
 195 {
 196         struct llog_log_hdr *llh = loghandle->lgh_hdr;
 197         struct llog_process_cat_data *cd = catdata;
 198         void *buf;
 199         __u64 cur_offset = LLOG_CHUNK_SIZE;
 200         int rc = 0, index = 1, last_index, idx;
 201         int saved_index = 0;
 202         ENTRY;
 203
 204         OBD_ALLOC(buf, LLOG_CHUNK_SIZE);
 205         if (!buf)
 206                 RETURN(-ENOMEM);
 207
 208         if (cd != NULL)
 209                 index = cd->first_idx + 1;
 210         if (cd != NULL && cd->last_idx)
 211                 last_index = cd->last_idx;
 212         else
 213                 last_index = LLOG_BITMAP_BYTES * 8 - 1;
 214
 215         while (rc == 0) {
 216                 struct llog_rec_hdr *rec;
 217
 218                 /* skip records not set in bitmap */
 219                 while (index <= last_index &&
 220                        !ext2_test_bit(index, llh->llh_bitmap))
 221                         ++index;
 222
 223                 LASSERT(index <= last_index + 1);
 224                 if (index == last_index + 1)
 225                         break;
 226
 227                 /* get the buf with our target record; avoid old garbage */
 228                 memset(buf, 0, LLOG_CHUNK_SIZE);
 229                 rc = llog_next_block(loghandle, &saved_index, index,
 230                                      &cur_offset, buf, LLOG_CHUNK_SIZE);
 231                 if (rc)
 232                         GOTO(out, rc);
 233
 234                 rec = buf;
 235                 idx = le32_to_cpu(rec->lrh_index);
 236                 if (idx < index)
 237                         CDEBUG(D_HA, "index %u : idx %u\n", index, idx);
 238                 while (idx < index) {
 239                         rec = ((void *)rec + le32_to_cpu(rec->lrh_len));
 240                         idx ++;
 241                 }
 242
 243                 /* process records in buffer, starting where we found one */
 244                 while ((void *)rec < buf + LLOG_CHUNK_SIZE) {
 245                         if (rec->lrh_index == 0)
 246                                 GOTO(out, 0); /* no more records */
 247
 248                         /* if set, process the callback on this record */
 249                         if (ext2_test_bit(index, llh->llh_bitmap)) {
 250                                 rc = cb(loghandle, rec, data);
 251                                 if (rc == LLOG_PROC_BREAK) {
 252                                         CWARN("recovery from log: "LPX64":%x"
 253                                               " stopped\n",
 254                                               loghandle->lgh_id.lgl_oid,
 255                                               loghandle->lgh_id.lgl_ogen);
 256                                         GOTO(out, rc);
 257                                 }
 258                                 if (rc)
 259                                         GOTO(out, rc);
 260                         }
 261
 262                         /* next record, still in buffer? */
 263                         ++index;
 264                         if (index > last_index)
 265                                 GOTO(out, rc = 0);
 266                         rec = ((void *)rec + le32_to_cpu(rec->lrh_len));
 267                 }
 268         }
 269
 270  out:
 271         if (buf)
 272                 OBD_FREE(buf, LLOG_CHUNK_SIZE);
 273         RETURN(rc);
 274 }
 275 EXPORT_SYMBOL(llog_process);
 276
 277 int llog_reverse_process(struct llog_handle *loghandle, llog_cb_t cb,
 278                          void *data, void *catdata)
 279 {
 280         struct llog_log_hdr *llh = loghandle->lgh_hdr;
 281         struct llog_process_cat_data *cd = catdata;
 282         void *buf;
 283         int rc = 0, first_index = 1, index, idx;
 284         struct llog_rec_tail *tail;
 285         ENTRY;
 286
 287         OBD_ALLOC(buf, LLOG_CHUNK_SIZE);
 288         if (!buf)
 289                 RETURN(-ENOMEM);
 290
 291         if (cd != NULL)
 292                 first_index = cd->first_idx + 1;
 293         if (cd != NULL && cd->last_idx)
 294                 index = cd->last_idx;
 295         else
 296                 index = LLOG_BITMAP_BYTES * 8 - 1;
 297
 298         while (rc == 0) {
 299                 struct llog_rec_hdr *rec;
 300
 301                 /* skip records not set in bitmap */
 302                 while (index >= first_index &&
 303                        !ext2_test_bit(index, llh->llh_bitmap))
 304                         --index;
 305
 306                 LASSERT(index >= first_index - 1);
 307                 if (index == first_index - 1)
 308                         break;
 309
 310                 /* get the buf with our target record; avoid old garbage */
 311                 memset(buf, 0, LLOG_CHUNK_SIZE);
 312                 rc = llog_prev_block(loghandle, index, buf, LLOG_CHUNK_SIZE);
 313                 if (rc)
 314                         GOTO(out, rc);
 315
 316                 rec = buf;
 317                 idx = le32_to_cpu(rec->lrh_index);
 318                 if (idx < index)
 319                         CDEBUG(D_HA, "index %u : idx %u\n", index, idx);
 320                 while (idx < index) {
 321                         rec = ((void *)rec + le32_to_cpu(rec->lrh_len));
 322                         idx ++;
 323                 }
 324
 325                 /* process records in buffer, starting where we found one */
 326                 while ((void *)rec >= buf) {
 327                         if (rec->lrh_index == 0)
 328                                 GOTO(out, 0); /* no more records */
 329
 330                         /* if set, process the callback on this record */
 331                         if (ext2_test_bit(index, llh->llh_bitmap)) {
 332                                 rc = cb(loghandle, rec, data);
 333                                 if (rc == LLOG_PROC_BREAK) {
 334                                         CWARN("recovery from log: "LPX64":%x"
 335                                               " stopped\n",
 336                                               loghandle->lgh_id.lgl_oid,
 337                                               loghandle->lgh_id.lgl_ogen);
 338                                         GOTO(out, rc);
 339                                 }
 340                                 if (rc)
 341                                         GOTO(out, rc);
 342                         }
 343
 344                         /* previous record, still in buffer? */
 345                         --index;
 346                         if (index < first_index)
 347                                 GOTO(out, rc = 0);
 348
 349                         if ((void *)rec == buf)
 350                                 break;
 351
 352                         tail = (void *)rec - sizeof(struct llog_rec_tail);
 353                         rec = ((void *)rec - le32_to_cpu(tail->lrt_len));
 354                 }
 355         }
 356
 357  out:
 358         if (buf)
 359                 OBD_FREE(buf, LLOG_CHUNK_SIZE);
 360         RETURN(rc);
 361 }
 362 EXPORT_SYMBOL(llog_reverse_process);