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.
61 static char *add_suffix(const char *name
, const char *suffix
)
64 int len
= strlen(name
) + strlen(suffix
) + 1;
67 fprintf(stderr
,"Out of memory!\n");
70 strncpy(ret
, name
, len
);
71 strncat(ret
, suffix
, len
);
75 static int copy_fn(TDB_CONTEXT
*tdb
, TDB_DATA key
, TDB_DATA dbuf
, void *state
)
77 TDB_CONTEXT
*tdb_new
= (TDB_CONTEXT
*)state
;
79 if (tdb_store(tdb_new
, key
, dbuf
, TDB_INSERT
) != 0) {
80 fprintf(stderr
,"Failed to insert into %s\n", tdb_new
->name
);
88 static int test_fn(TDB_CONTEXT
*tdb
, TDB_DATA key
, TDB_DATA dbuf
, void *state
)
94 carefully backup a tdb, validating the contents and
95 only doing the backup if its OK
96 this function is also used for restore
98 static int backup_tdb(const char *old_name
, const char *new_name
)
101 TDB_CONTEXT
*tdb_new
;
106 tmp_name
= add_suffix(new_name
, ".tmp");
108 /* stat the old tdb to find its permissions */
109 if (stat(old_name
, &st
) != 0) {
114 /* open the old tdb */
115 tdb
= tdb_open(old_name
, 0, 0, O_RDWR
, 0);
117 printf("Failed to open %s\n", old_name
);
121 /* create the new tdb */
123 tdb_new
= tdb_open(tmp_name
, tdb
->header
.hash_size
,
124 TDB_DEFAULT
, O_RDWR
|O_CREAT
|O_EXCL
,
132 /* lock the old tdb */
133 if (tdb_lockall(tdb
) != 0) {
134 fprintf(stderr
,"Failed to lock %s\n", old_name
);
144 /* traverse and copy */
145 count1
= tdb_traverse(tdb
, copy_fn
, (void *)tdb_new
);
146 if (count1
< 0 || failed
) {
147 fprintf(stderr
,"failed to copy %s\n", old_name
);
155 /* close the old tdb */
158 /* close the new tdb and re-open read-only */
160 tdb_new
= tdb_open(tmp_name
, 0, TDB_DEFAULT
, O_RDONLY
, 0);
162 fprintf(stderr
,"failed to reopen %s\n", tmp_name
);
169 /* traverse the new tdb to confirm */
170 count2
= tdb_traverse(tdb_new
, test_fn
, 0);
171 if (count2
!= count1
) {
172 fprintf(stderr
,"failed to copy %s\n", old_name
);
179 /* make sure the new tdb has reached stable storage */
182 /* close the new tdb and rename it to .bak */
185 if (rename(tmp_name
, new_name
) != 0) {
191 printf("%s : %d records\n", old_name
, count1
);
200 verify a tdb and if it is corrupt then restore from *.bak
202 static int verify_tdb(const char *fname
, const char *bak_name
)
208 tdb
= tdb_open(fname
, 0, 0, O_RDONLY
, 0);
210 /* traverse the tdb, then close it */
212 count
= tdb_traverse(tdb
, test_fn
, NULL
);
216 /* count is < 0 means an error */
218 printf("restoring %s\n", fname
);
219 return backup_tdb(bak_name
, fname
);
222 printf("%s : %d records\n", fname
, count
);
229 see if one file is newer than another
231 static int file_newer(const char *fname1
, const char *fname2
)
233 struct stat st1
, st2
;
234 if (stat(fname1
, &st1
) != 0) {
237 if (stat(fname2
, &st2
) != 0) {
240 return (st1
.st_mtime
> st2
.st_mtime
);
243 static void usage(void)
245 printf("Usage: tdbbackup [options] <fname...>\n\n");
246 printf(" -h this help message\n");
247 printf(" -s suffix set the backup suffix\n");
248 printf(" -v veryify mode (restore if corrupt)\n");
252 int main(int argc
, char *argv
[])
258 char *suffix
= ".bak";
262 while ((c
= getopt(argc
, argv
, "vhs:")) != -1) {
284 for (i
=0; i
<argc
; i
++) {
285 const char *fname
= argv
[i
];
288 bak_name
= add_suffix(fname
, suffix
);
291 if (verify_tdb(fname
, bak_name
) != 0) {
295 if (file_newer(fname
, bak_name
) &&
296 backup_tdb(fname
, bak_name
) != 0) {