lustre/obdclass/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 the Lustre file system, http://www.lustre.org
   8  *   Lustre is a trademark of Cluster File Systems, Inc.
   9  *
  10  *   You may have signed or agreed to another license before downloading
  11  *   this software.  If so, you are bound by the terms and conditions
  12  *   of that agreement, and the following does not apply to you.  See the
  13  *   LICENSE file included with this distribution for more information.
  14  *
  15  *   If you did not agree to a different license, then this copy of Lustre
  16  *   is open source software; you can redistribute it and/or modify it
  17  *   under the terms of version 2 of the GNU General Public License as
  18  *   published by the Free Software Foundation.
  19  *
  20  *   In either case, Lustre is distributed in the hope that it will be
  21  *   useful, but WITHOUT ANY WARRANTY; without even the implied warranty
  22  *   of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23  *   license text for more details.
  24  *
  25  * OST<->MDS recovery logging infrastructure.
  26  *
  27  * Invariants in implementation:
  28  * - we do not share logs among different OST<->MDS connections, so that
  29  *   if an OST or MDS fails it need only look at log(s) relevant to itself
  30  */
  31
  32 #define DEBUG_SUBSYSTEM S_LOG
  33
  34 #ifndef EXPORT_SYMTAB
  35 #define EXPORT_SYMTAB
  36 #endif
  37
  38 #ifdef __KERNEL__
  39 #include <linux/fs.h>
  40 #else
  41 #include <liblustre.h>
  42 #endif
  43
  44 #include <linux/obd_class.h>
  45 #include <linux/lustre_log.h>
  46 #include <libcfs/list.h>
  47
  48 /* Allocate a new log or catalog handle */
  49 struct llog_handle *llog_alloc_handle(void)
  50 {
  51         struct llog_handle *loghandle;
  52         ENTRY;
  53
  54         OBD_ALLOC(loghandle, sizeof(*loghandle));
  55         if (loghandle == NULL)
  56                 RETURN(ERR_PTR(-ENOMEM));
  57
  58         init_rwsem(&loghandle->lgh_lock);
  59
  60         RETURN(loghandle);
  61 }
  62 EXPORT_SYMBOL(llog_alloc_handle);
  63
  64
  65 void llog_free_handle(struct llog_handle *loghandle)
  66 {
  67         if (!loghandle)
  68                 return;
  69
  70         if (!loghandle->lgh_hdr)
  71                 goto out;
  72         if (loghandle->lgh_hdr->llh_flags & LLOG_F_IS_PLAIN)
  73                 list_del_init(&loghandle->u.phd.phd_entry);
  74         if (loghandle->lgh_hdr->llh_flags & LLOG_F_IS_CAT)
  75                 LASSERT(list_empty(&loghandle->u.chd.chd_head));
  76         OBD_FREE(loghandle->lgh_hdr, LLOG_CHUNK_SIZE);
  77
  78  out:
  79         OBD_FREE(loghandle, sizeof(*loghandle));
  80 }
  81 EXPORT_SYMBOL(llog_free_handle);
  82
  83 /* returns negative on error; 0 if success; 1 if success & log destroyed */
  84 int llog_cancel_rec(struct llog_handle *loghandle, int index)
  85 {
  86         struct llog_log_hdr *llh = loghandle->lgh_hdr;
  87         int rc = 0;
  88         ENTRY;
  89
  90         CDEBUG(D_HA, "canceling %d in log "LPX64"\n",
  91                index, loghandle->lgh_id.lgl_oid);
  92
  93         if (index == 0) {
  94                 CERROR("cannot cancel index 0 (which is header)\n");
  95                 RETURN(-EINVAL);
  96         }
  97
  98         if (!ext2_clear_bit(index, llh->llh_bitmap)) {
  99                 CDEBUG(D_HA, "catalog index %u already clear?\n", index);
 100                 RETURN(-EINVAL);
 101         }
 102
 103         llh->llh_count--;
 104
 105         if ((llh->llh_flags & LLOG_F_ZAP_WHEN_EMPTY) &&
 106             (llh->llh_count == 1) &&
 107             (loghandle->lgh_last_idx == (LLOG_BITMAP_BYTES * 8) - 1)) {
 108                 rc = llog_destroy(loghandle);
 109                 if (rc) {
 110                         CERROR("failure destroying log after last cancel: %d\n",
 111                                rc);
 112                         ext2_set_bit(index, llh->llh_bitmap);
 113                         llh->llh_count++;
 114                 } else {
 115                         rc = 1;
 116                 }
 117                 RETURN(rc);
 118         }
 119
 120         rc = llog_write_rec(loghandle, &llh->llh_hdr, NULL, 0, NULL, 0);
 121         if (rc) {
 122                 CERROR("failure re-writing header %d\n", rc);
 123                 ext2_set_bit(index, llh->llh_bitmap);
 124                 llh->llh_count++;
 125         }
 126         RETURN(rc);
 127 }
 128 EXPORT_SYMBOL(llog_cancel_rec);
 129
 130 int llog_init_handle(struct llog_handle *handle, int flags,
 131                      struct obd_uuid *uuid)
 132 {
 133         int rc;
 134         struct llog_log_hdr *llh;
 135         ENTRY;
 136         LASSERT(handle->lgh_hdr == NULL);
 137
 138         OBD_ALLOC(llh, sizeof(*llh));
 139         if (llh == NULL)
 140                 RETURN(-ENOMEM);
 141         handle->lgh_hdr = llh;
 142         /* first assign flags to use llog_client_ops */
 143         llh->llh_flags = flags;
 144         rc = llog_read_header(handle);
 145         if (rc == 0) {
 146                 flags = llh->llh_flags;
 147                 if (uuid)
 148                         LASSERT(obd_uuid_equals(uuid, &llh->llh_tgtuuid));
 149                 GOTO(out, rc);
 150         } else if (rc != LLOG_EEMPTY || !flags) {
 151                 /* set a pesudo flag for initialization */
 152                 flags = LLOG_F_IS_CAT;
 153                 GOTO(out, rc);
 154         }
 155         rc = 0;
 156
 157         handle->lgh_last_idx = 0; /* header is record with index 0 */
 158         llh->llh_count = 1;         /* for the header record */
 159         llh->llh_hdr.lrh_type = LLOG_HDR_MAGIC;
 160         llh->llh_hdr.lrh_len = llh->llh_tail.lrt_len = LLOG_CHUNK_SIZE;
 161         llh->llh_hdr.lrh_index = llh->llh_tail.lrt_index = 0;
 162         llh->llh_timestamp = CURRENT_SECONDS;
 163         if (uuid)
 164                 memcpy(&llh->llh_tgtuuid, uuid, sizeof(llh->llh_tgtuuid));
 165         llh->llh_bitmap_offset = offsetof(typeof(*llh),llh_bitmap);
 166         ext2_set_bit(0, llh->llh_bitmap);
 167
 168 out:
 169         if (flags & LLOG_F_IS_CAT) {
 170                 INIT_LIST_HEAD(&handle->u.chd.chd_head);
 171                 llh->llh_size = sizeof(struct llog_logid_rec);
 172         } else if (flags & LLOG_F_IS_PLAIN) {
 173                 INIT_LIST_HEAD(&handle->u.phd.phd_entry);
 174         } else {
 175                 CERROR("Unknown flags: %#x (Expected %#x or %#x\n",
 176                        flags, LLOG_F_IS_CAT, LLOG_F_IS_PLAIN);
 177                 LBUG();
 178         }
 179
 180         if (rc) {
 181                 OBD_FREE(llh, sizeof(*llh));
 182                 handle->lgh_hdr = NULL;
 183         }
 184         RETURN(rc);
 185 }
 186 EXPORT_SYMBOL(llog_init_handle);
 187
 188 int llog_close(struct llog_handle *loghandle)
 189 {
 190         struct llog_operations *lop;
 191         int rc;
 192         ENTRY;
 193
 194         rc = llog_handle2ops(loghandle, &lop);
 195         if (rc)
 196                 GOTO(out, rc);
 197         if (lop->lop_close == NULL)
 198                 GOTO(out, -EOPNOTSUPP);
 199         rc = lop->lop_close(loghandle);
 200  out:
 201         llog_free_handle(loghandle);
 202         RETURN(rc);
 203 }
 204 EXPORT_SYMBOL(llog_close);
 205
 206 int llog_process(struct llog_handle *loghandle, llog_cb_t cb,
 207                  void *data, void *catdata)
 208 {
 209         struct llog_log_hdr *llh = loghandle->lgh_hdr;
 210         struct llog_process_cat_data *cd = catdata;
 211         char *buf;
 212         __u64 cur_offset = LLOG_CHUNK_SIZE;
 213         int rc = 0, index = 1, last_index;
 214         int saved_index = 0;
 215         ENTRY;
 216
 217         OBD_ALLOC(buf, LLOG_CHUNK_SIZE);
 218         if (!buf)
 219                 RETURN(-ENOMEM);
 220
 221         if (cd != NULL)
 222                 index = cd->first_idx + 1;
 223         if (cd != NULL && cd->last_idx)
 224                 last_index = cd->last_idx;
 225         else
 226                 last_index = LLOG_BITMAP_BYTES * 8 - 1;
 227
 228         while (rc == 0) {
 229                 struct llog_rec_hdr *rec;
 230
 231                 /* skip records not set in bitmap */
 232                 while (index <= last_index &&
 233                        !ext2_test_bit(index, llh->llh_bitmap))
 234                         ++index;
 235
 236                 LASSERT(index <= last_index + 1);
 237                 if (index == last_index + 1)
 238                         break;
 239
 240                 CDEBUG(D_OTHER, "index: %d last_index %d\n",
 241                        index, last_index);
 242
 243                 /* get the buf with our target record; avoid old garbage */
 244                 memset(buf, 0, LLOG_CHUNK_SIZE);
 245                 rc = llog_next_block(loghandle, &saved_index, index,
 246                                      &cur_offset, buf, LLOG_CHUNK_SIZE);
 247                 if (rc)
 248                         GOTO(out, rc);
 249
 250                 /* NB: when rec->lrh_len is accessed it is already swabbed
 251                  * since it is used at the "end" of the loop and the rec
 252                  * swabbing is done at the beginning of the loop. */
 253                 for (rec = (struct llog_rec_hdr *)buf;
 254                      (char *)rec < buf + LLOG_CHUNK_SIZE;
 255                      rec = (struct llog_rec_hdr *)((char *)rec + rec->lrh_len)){
 256
 257                         CDEBUG(D_OTHER, "processing rec 0x%p type %#x\n",
 258                                rec, rec->lrh_type);
 259
 260                         if (LLOG_REC_HDR_NEEDS_SWABBING(rec))
 261                                 lustre_swab_llog_rec(rec, NULL);
 262
 263                         CDEBUG(D_OTHER, "after swabbing, type: %#x\n",
 264                                rec->lrh_type);
 265
 266                         if (rec->lrh_index == 0)
 267                                 GOTO(out, 0); /* no more records */
 268
 269                         if (rec->lrh_len == 0 || rec->lrh_len >LLOG_CHUNK_SIZE){
 270                                 CWARN("invalid length %d in llog record for "
 271                                       "index %d\n", rec->lrh_len,
 272                                 rec->lrh_index);
 273                                 GOTO(out, 0);
 274                         }
 275
 276                         if (rec->lrh_index < index) {
 277                                 CDEBUG(D_OTHER, "skipping lrh_index %d\n",
 278                                        rec->lrh_index);
 279                                 continue;
 280                         }
 281
 282                         CDEBUG(D_OTHER,
 283                                "lrh_index: %d lrh_len: %d (%d remains)\n",
 284                                rec->lrh_index, rec->lrh_len,
 285                                (int)(buf + LLOG_CHUNK_SIZE - (char *)rec));
 286
 287                         /* if set, process the callback on this record */
 288                         if (ext2_test_bit(index, llh->llh_bitmap)) {
 289                                 rc = cb(loghandle, rec, data);
 290                                 if (rc == LLOG_PROC_BREAK) {
 291                                         CWARN("recovery from log: "LPX64":%x"
 292                                               " stopped\n",
 293                                               loghandle->lgh_id.lgl_oid,
 294                                               loghandle->lgh_id.lgl_ogen);
 295                                         GOTO(out, rc);
 296                                 }
 297                                 if (rc)
 298                                         GOTO(out, rc);
 299                         } else {
 300                                 CDEBUG(D_OTHER, "Skipped index %d\n", index);
 301                         }
 302
 303                         /* next record, still in buffer? */
 304                         ++index;
 305                         if (index > last_index)
 306                                 GOTO(out, rc = 0);
 307                 }
 308         }
 309
 310  out:
 311         if (buf)
 312                 OBD_FREE(buf, LLOG_CHUNK_SIZE);
 313         RETURN(rc);
 314 }
 315 EXPORT_SYMBOL(llog_process);