2 Unix SMB/CIFS implementation.
3 low level tdb backup and restore utility
4 Copyright (C) Andrew Tridgell 2002
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 This program is meant for backup/restore of tdb databases. Typical usage would be:
25 when Samba shuts down cleanly, which will make a backup of all the local databases
26 to *.bak files. Then on Samba startup you would use:
28 and this will check the databases for corruption and if corruption is detected then
29 the backup will be restored.
31 You may also like to do a backup on a regular basis while Samba is
32 running, perhaps using cron.
34 The reason this program is needed is to cope with power failures
35 while Samba is running. A power failure could lead to database
36 corruption and Samba will then not start correctly.
38 Note that many of the databases in Samba are transient and thus
39 don't need to be backed up, so you can optimise the above a little
40 by only running the backup on the critical databases.
60 static char *add_suffix(const char *name, const char *suffix)
63 int len = strlen(name) + strlen(suffix) + 1;
66 fprintf(stderr,"Out of memory!\n");
69 strncpy(ret, name, len);
70 strncat(ret, suffix, len);
74 static int copy_fn(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, void *state)
76 TDB_CONTEXT *tdb_new = (TDB_CONTEXT *)state;
78 if (tdb_store(tdb_new, key, dbuf, TDB_INSERT) != 0) {
79 fprintf(stderr,"Failed to insert into %s\n", tdb_new->name);
87 static int test_fn(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, void *state)
93 carefully backup a tdb, validating the contents and
94 only doing the backup if its OK
95 this function is also used for restore
97 static int backup_tdb(const char *old_name, const char *new_name)
100 TDB_CONTEXT *tdb_new;
105 tmp_name = add_suffix(new_name, ".tmp");
107 /* stat the old tdb to find its permissions */
108 if (stat(old_name, &st) != 0) {
113 /* open the old tdb */
114 tdb = tdb_open(old_name, 0, 0, O_RDWR, 0);
116 printf("Failed to open %s\n", old_name);
120 /* create the new tdb */
122 tdb_new = tdb_open(tmp_name, tdb->header.hash_size,
123 TDB_DEFAULT, O_RDWR|O_CREAT|O_EXCL,
131 /* lock the old tdb */
132 if (tdb_lockall(tdb) != 0) {
133 fprintf(stderr,"Failed to lock %s\n", old_name);
143 /* traverse and copy */
144 count1 = tdb_traverse(tdb, copy_fn, (void *)tdb_new);
145 if (count1 < 0 || failed) {
146 fprintf(stderr,"failed to copy %s\n", old_name);
154 /* close the old tdb */
157 /* close the new tdb and re-open read-only */
159 tdb_new = tdb_open(tmp_name, 0, TDB_DEFAULT, O_RDONLY, 0);
161 fprintf(stderr,"failed to reopen %s\n", tmp_name);
168 /* traverse the new tdb to confirm */
169 count2 = tdb_traverse(tdb_new, test_fn, 0);
170 if (count2 != count1) {
171 fprintf(stderr,"failed to copy %s\n", old_name);
178 /* make sure the new tdb has reached stable storage */
181 /* close the new tdb and rename it to .bak */
184 if (rename(tmp_name, new_name) != 0) {
190 printf("%s : %d records\n", old_name, count1);
199 verify a tdb and if it is corrupt then restore from *.bak
201 static int verify_tdb(const char *fname, const char *bak_name)
207 tdb = tdb_open(fname, 0, 0, O_RDONLY, 0);
209 /* traverse the tdb, then close it */
211 count = tdb_traverse(tdb, test_fn, NULL);
215 /* count is < 0 means an error */
217 printf("restoring %s\n", fname);
218 return backup_tdb(bak_name, fname);
221 printf("%s : %d records\n", fname, count);
228 see if one file is newer than another
230 static int file_newer(const char *fname1, const char *fname2)
232 struct stat st1, st2;
233 if (stat(fname1, &st1) != 0) {
236 if (stat(fname2, &st2) != 0) {
239 return (st1.st_mtime > st2.st_mtime);
242 static void usage(void)
244 printf("Usage: tdbbackup [options] <fname...>\n\n");
245 printf(" -h this help message\n");
246 printf(" -s suffix set the backup suffix\n");
247 printf(" -v veryify mode (restore if corrupt)\n");
251 int main(int argc, char *argv[])
257 char *suffix = ".bak";
261 while ((c = getopt(argc, argv, "vhs:")) != -1) {
283 for (i=0; i<argc; i++) {
284 const char *fname = argv[i];
287 bak_name = add_suffix(fname, suffix);
290 if (verify_tdb(fname, bak_name) != 0) {
294 if (file_newer(fname, bak_name) &&
295 backup_tdb(fname, bak_name) != 0) {