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