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 3 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, see <http://www.gnu.org/licenses/>.
22 This program is meant for backup/restore of tdb databases. Typical usage would be:
24 when Samba shuts down cleanly, which will make a backup of all the local databases
25 to *.bak files. Then on Samba startup you would use:
27 and this will check the databases for corruption and if corruption is detected then
28 the backup will be restored.
30 You may also like to do a backup on a regular basis while Samba is
31 running, perhaps using cron.
33 The reason this program is needed is to cope with power failures
34 while Samba is running. A power failure could lead to database
35 corruption and Samba will then not start correctly.
37 Note that many of the databases in Samba are transient and thus
38 don't need to be backed up, so you can optimise the above a little
39 by only running the backup on the critical databases.
44 #include "system/locale.h"
45 #include "system/time.h"
46 #include "system/filesys.h"
47 #include "system/wait.h"
56 static char *add_suffix(const char *name, const char *suffix)
59 int len = strlen(name) + strlen(suffix) + 1;
60 ret = (char *)malloc(len);
62 fprintf(stderr,"Out of memory!\n");
65 snprintf(ret, len, "%s%s", name, suffix);
69 static int copy_fn(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, void *state)
71 TDB_CONTEXT *tdb_new = (TDB_CONTEXT *)state;
73 if (tdb_store(tdb_new, key, dbuf, TDB_INSERT) != 0) {
74 fprintf(stderr,"Failed to insert into %s\n", tdb_name(tdb_new));
82 static int test_fn(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, void *state)
88 carefully backup a tdb, validating the contents and
89 only doing the backup if its OK
90 this function is also used for restore
92 static int backup_tdb(const char *old_name, const char *new_name, int hash_size)
100 tmp_name = add_suffix(new_name, ".tmp");
102 /* stat the old tdb to find its permissions */
103 if (stat(old_name, &st) != 0) {
109 /* open the old tdb */
110 tdb = tdb_open(old_name, 0, 0, O_RDWR, 0);
112 printf("Failed to open %s\n", old_name);
117 /* create the new tdb */
119 tdb_new = tdb_open(tmp_name,
120 hash_size ? hash_size : tdb_hash_size(tdb),
121 TDB_DEFAULT, O_RDWR|O_CREAT|O_EXCL,
129 if (tdb_transaction_start(tdb) != 0) {
130 printf("Failed to start transaction on old tdb\n");
138 if (tdb_transaction_start(tdb_new) != 0) {
139 printf("Failed to start transaction on new tdb\n");
149 /* traverse and copy */
150 count1 = tdb_traverse(tdb, copy_fn, (void *)tdb_new);
151 if (count1 < 0 || failed) {
152 fprintf(stderr,"failed to copy %s\n", old_name);
160 /* close the old tdb */
163 if (tdb_transaction_commit(tdb_new) != 0) {
164 fprintf(stderr, "Failed to commit new tdb\n");
171 /* close the new tdb and re-open read-only */
173 tdb_new = tdb_open(tmp_name, 0, TDB_DEFAULT, O_RDONLY, 0);
175 fprintf(stderr,"failed to reopen %s\n", tmp_name);
182 /* traverse the new tdb to confirm */
183 count2 = tdb_traverse(tdb_new, test_fn, NULL);
184 if (count2 != count1) {
185 fprintf(stderr,"failed to copy %s\n", old_name);
192 /* close the new tdb and rename it to .bak */
194 if (rename(tmp_name, new_name) != 0) {
206 verify a tdb and if it is corrupt then restore from *.bak
208 static int verify_tdb(const char *fname, const char *bak_name)
214 tdb = tdb_open(fname, 0, 0, O_RDONLY, 0);
216 /* traverse the tdb, then close it */
218 count = tdb_traverse(tdb, test_fn, NULL);
222 /* count is < 0 means an error */
224 printf("restoring %s\n", fname);
225 return backup_tdb(bak_name, fname, 0);
228 printf("%s : %d records\n", fname, count);
234 see if one file is newer than another
236 static int file_newer(const char *fname1, const char *fname2)
238 struct stat st1, st2;
239 if (stat(fname1, &st1) != 0) {
242 if (stat(fname2, &st2) != 0) {
245 return (st1.st_mtime > st2.st_mtime);
248 static void usage(void)
250 printf("Usage: tdbbackup [options] <fname...>\n\n");
251 printf(" -h this help message\n");
252 printf(" -s suffix set the backup suffix\n");
253 printf(" -v verify mode (restore if corrupt)\n");
254 printf(" -n hashsize set the new hash size for the backup\n");
258 int main(int argc, char *argv[])
265 const char *suffix = ".bak";
267 while ((c = getopt(argc, argv, "vhs:n:")) != -1) {
279 hashsize = atoi(optarg);
292 for (i=0; i<argc; i++) {
293 const char *fname = argv[i];
296 bak_name = add_suffix(fname, suffix);
299 if (verify_tdb(fname, bak_name) != 0) {
303 if (file_newer(fname, bak_name) &&
304 backup_tdb(fname, bak_name, hashsize) != 0) {