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"
55 static char *add_suffix(const char *name, const char *suffix)
58 int len = strlen(name) + strlen(suffix) + 1;
59 ret = (char *)malloc(len);
61 fprintf(stderr,"Out of memory!\n");
64 snprintf(ret, len, "%s%s", name, suffix);
68 static int copy_fn(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, void *state)
70 TDB_CONTEXT *tdb_new = (TDB_CONTEXT *)state;
72 if (tdb_store(tdb_new, key, dbuf, TDB_INSERT) != 0) {
73 fprintf(stderr,"Failed to insert into %s\n", tdb_name(tdb_new));
81 static int test_fn(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, void *state)
87 carefully backup a tdb, validating the contents and
88 only doing the backup if its OK
89 this function is also used for restore
91 static int backup_tdb(const char *old_name, const char *new_name, int hash_size)
99 tmp_name = add_suffix(new_name, ".tmp");
101 /* stat the old tdb to find its permissions */
102 if (stat(old_name, &st) != 0) {
108 /* open the old tdb */
109 tdb = tdb_open(old_name, 0, 0, O_RDWR, 0);
111 printf("Failed to open %s\n", old_name);
116 /* create the new tdb */
118 tdb_new = tdb_open(tmp_name,
119 hash_size ? hash_size : tdb_hash_size(tdb),
120 TDB_DEFAULT, O_RDWR|O_CREAT|O_EXCL,
128 /* lock the old tdb */
129 if (tdb_lockall(tdb) != 0) {
130 fprintf(stderr,"Failed to lock %s\n", old_name);
140 /* traverse and copy */
141 count1 = tdb_traverse(tdb, copy_fn, (void *)tdb_new);
142 if (count1 < 0 || failed) {
143 fprintf(stderr,"failed to copy %s\n", old_name);
151 /* close the old tdb */
154 /* close the new tdb and re-open read-only */
156 tdb_new = tdb_open(tmp_name, 0, TDB_DEFAULT, O_RDONLY, 0);
158 fprintf(stderr,"failed to reopen %s\n", tmp_name);
165 /* traverse the new tdb to confirm */
166 count2 = tdb_traverse(tdb_new, test_fn, NULL);
167 if (count2 != count1) {
168 fprintf(stderr,"failed to copy %s\n", old_name);
175 /* make sure the new tdb has reached stable storage */
176 fsync(tdb_fd(tdb_new));
178 /* close the new tdb and rename it to .bak */
180 if (rename(tmp_name, new_name) != 0) {
192 verify a tdb and if it is corrupt then restore from *.bak
194 static int verify_tdb(const char *fname, const char *bak_name)
200 tdb = tdb_open(fname, 0, 0, O_RDONLY, 0);
202 /* traverse the tdb, then close it */
204 count = tdb_traverse(tdb, test_fn, NULL);
208 /* count is < 0 means an error */
210 printf("restoring %s\n", fname);
211 return backup_tdb(bak_name, fname, 0);
214 printf("%s : %d records\n", fname, count);
220 see if one file is newer than another
222 static int file_newer(const char *fname1, const char *fname2)
224 struct stat st1, st2;
225 if (stat(fname1, &st1) != 0) {
228 if (stat(fname2, &st2) != 0) {
231 return (st1.st_mtime > st2.st_mtime);
234 static void usage(void)
236 printf("Usage: tdbbackup [options] <fname...>\n\n");
237 printf(" -h this help message\n");
238 printf(" -s suffix set the backup suffix\n");
239 printf(" -v verify mode (restore if corrupt)\n");
240 printf(" -n hashsize set the new hash size for the backup\n");
244 int main(int argc, char *argv[])
251 const char *suffix = ".bak";
253 while ((c = getopt(argc, argv, "vhs:n:")) != -1) {
265 hashsize = atoi(optarg);
278 for (i=0; i<argc; i++) {
279 const char *fname = argv[i];
282 bak_name = add_suffix(fname, suffix);
285 if (verify_tdb(fname, bak_name) != 0) {
289 if (file_newer(fname, bak_name) &&
290 backup_tdb(fname, bak_name, hashsize) != 0) {