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 struct tdb_logging_context log_ctx
;
58 #ifdef PRINTF_ATTRIBUTE
59 static void tdb_log(struct tdb_context
*tdb
, enum tdb_debug_level level
, const char *format
, ...) PRINTF_ATTRIBUTE(3,4);
61 static void tdb_log(struct tdb_context
*tdb
, enum tdb_debug_level level
, const char *format
, ...)
66 vfprintf(stdout
, format
, ap
);
71 static char *add_suffix(const char *name
, const char *suffix
)
74 int len
= strlen(name
) + strlen(suffix
) + 1;
75 ret
= (char *)malloc(len
);
77 fprintf(stderr
,"Out of memory!\n");
80 snprintf(ret
, len
, "%s%s", name
, suffix
);
84 static int copy_fn(TDB_CONTEXT
*tdb
, TDB_DATA key
, TDB_DATA dbuf
, void *state
)
86 TDB_CONTEXT
*tdb_new
= (TDB_CONTEXT
*)state
;
88 if (tdb_store(tdb_new
, key
, dbuf
, TDB_INSERT
) != 0) {
89 fprintf(stderr
,"Failed to insert into %s\n", tdb_name(tdb_new
));
97 static int test_fn(TDB_CONTEXT
*tdb
, TDB_DATA key
, TDB_DATA dbuf
, void *state
)
103 carefully backup a tdb, validating the contents and
104 only doing the backup if its OK
105 this function is also used for restore
107 static int backup_tdb(const char *old_name
, const char *new_name
, int hash_size
)
110 TDB_CONTEXT
*tdb_new
;
115 tmp_name
= add_suffix(new_name
, ".tmp");
117 /* stat the old tdb to find its permissions */
118 if (stat(old_name
, &st
) != 0) {
124 /* open the old tdb */
125 tdb
= tdb_open_ex(old_name
, 0, 0,
126 O_RDWR
, 0, &log_ctx
, NULL
);
128 printf("Failed to open %s\n", old_name
);
133 /* create the new tdb */
135 tdb_new
= tdb_open_ex(tmp_name
,
136 hash_size
? hash_size
: tdb_hash_size(tdb
),
138 O_RDWR
|O_CREAT
|O_EXCL
, st
.st_mode
& 0777,
146 if (tdb_transaction_start(tdb
) != 0) {
147 printf("Failed to start transaction on old tdb\n");
155 if (tdb_transaction_start(tdb_new
) != 0) {
156 printf("Failed to start transaction on new tdb\n");
166 /* traverse and copy */
167 count1
= tdb_traverse(tdb
, copy_fn
, (void *)tdb_new
);
168 if (count1
< 0 || failed
) {
169 fprintf(stderr
,"failed to copy %s\n", old_name
);
177 /* close the old tdb */
180 if (tdb_transaction_commit(tdb_new
) != 0) {
181 fprintf(stderr
, "Failed to commit new tdb\n");
188 /* close the new tdb and re-open read-only */
190 tdb_new
= tdb_open_ex(tmp_name
,
196 fprintf(stderr
,"failed to reopen %s\n", tmp_name
);
203 /* traverse the new tdb to confirm */
204 count2
= tdb_traverse(tdb_new
, test_fn
, NULL
);
205 if (count2
!= count1
) {
206 fprintf(stderr
,"failed to copy %s\n", old_name
);
213 /* close the new tdb and rename it to .bak */
215 if (rename(tmp_name
, new_name
) != 0) {
227 verify a tdb and if it is corrupt then restore from *.bak
229 static int verify_tdb(const char *fname
, const char *bak_name
)
235 tdb
= tdb_open_ex(fname
, 0, 0,
236 O_RDONLY
, 0, &log_ctx
, NULL
);
238 /* traverse the tdb, then close it */
240 count
= tdb_traverse(tdb
, test_fn
, NULL
);
244 /* count is < 0 means an error */
246 printf("restoring %s\n", fname
);
247 return backup_tdb(bak_name
, fname
, 0);
250 printf("%s : %d records\n", fname
, count
);
256 see if one file is newer than another
258 static int file_newer(const char *fname1
, const char *fname2
)
260 struct stat st1
, st2
;
261 if (stat(fname1
, &st1
) != 0) {
264 if (stat(fname2
, &st2
) != 0) {
267 return (st1
.st_mtime
> st2
.st_mtime
);
270 static void usage(void)
272 printf("Usage: tdbbackup [options] <fname...>\n\n");
273 printf(" -h this help message\n");
274 printf(" -s suffix set the backup suffix\n");
275 printf(" -v verify mode (restore if corrupt)\n");
276 printf(" -n hashsize set the new hash size for the backup\n");
280 int main(int argc
, char *argv
[])
287 const char *suffix
= ".bak";
289 log_ctx
.log_fn
= tdb_log
;
291 while ((c
= getopt(argc
, argv
, "vhs:n:")) != -1) {
303 hashsize
= atoi(optarg
);
316 for (i
=0; i
<argc
; i
++) {
317 const char *fname
= argv
[i
];
320 bak_name
= add_suffix(fname
, suffix
);
323 if (verify_tdb(fname
, bak_name
) != 0) {
327 if (file_newer(fname
, bak_name
) &&
328 backup_tdb(fname
, bak_name
, hashsize
) != 0) {