2 Unix SMB/CIFS implementation.
4 trivial database library
6 Copyright (C) Andrew Tridgell 1999-2004
7 Copyright (C) Paul `Rusty' Russell 2000
8 Copyright (C) Jeremy Allison 2000-2003
10 ** NOTE! The following LGPL license applies to the tdb
11 ** library. This does NOT imply that all of Samba is released
14 This library is free software; you can redistribute it and/or
15 modify it under the terms of the GNU Lesser General Public
16 License as published by the Free Software Foundation; either
17 version 2 of the License, or (at your option) any later version.
19 This library is distributed in the hope that it will be useful,
20 but WITHOUT ANY WARRANTY; without even the implied warranty of
21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 Lesser General Public License for more details.
24 You should have received a copy of the GNU Lesser General Public
25 License along with this library; if not, write to the Free Software
26 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
30 /* NOTE: If you use tdbs under valgrind, and in particular if you run
31 * tdbtorture, you may get spurious "uninitialized value" warnings. I
32 * think this is because valgrind doesn't understand that the mmap'd
33 * area may be written to by other processes. Memory can, from the
34 * point of view of the grinded process, spontaneously become
37 * I can think of a few solutions. [mbp 20030311]
39 * 1 - Write suppressions for Valgrind so that it doesn't complain
40 * about this. Probably the most reasonable but people need to
41 * remember to use them.
43 * 2 - Use IO not mmap when running under valgrind. Not so nice.
45 * 3 - Use the special valgrind macros to mark memory as valid at the
46 * right time. Probably too hard -- the process just doesn't know.
69 #if defined(PARANOID_MALLOC_CHECKER)
94 #define TDB_MAGIC_FOOD "TDB file\n"
95 #define TDB_VERSION (0x26011967 + 6)
96 #define TDB_MAGIC (0x26011999U)
97 #define TDB_FREE_MAGIC (~TDB_MAGIC)
98 #define TDB_DEAD_MAGIC (0xFEE1DEAD)
99 #define TDB_ALIGNMENT 4
100 #define MIN_REC_SIZE (2*sizeof(struct list_struct) + TDB_ALIGNMENT)
101 #define DEFAULT_HASH_SIZE 131
102 #define TDB_PAGE_SIZE 0x2000
103 #define FREELIST_TOP (sizeof(struct tdb_header))
104 #define TDB_ALIGN(x,a) (((x) + (a)-1) & ~((a)-1))
105 #define TDB_BYTEREV(x) (((((x)&0xff)<<24)|((x)&0xFF00)<<8)|(((x)>>8)&0xFF00)|((x)>>24))
106 #define TDB_DEAD(r) ((r)->magic == TDB_DEAD_MAGIC)
107 #define TDB_BAD_MAGIC(r) ((r)->magic != TDB_MAGIC && !TDB_DEAD(r))
108 #define TDB_HASH_TOP(hash) (FREELIST_TOP + (BUCKET(hash)+1)*sizeof(tdb_off))
109 #define TDB_DATA_START(hash_size) (TDB_HASH_TOP(hash_size-1) + TDB_SPINLOCK_SIZE(hash_size))
112 /* NB assumes there is a local variable called "tdb" that is the
113 * current context, also takes doubly-parenthesized print-style
115 #define TDB_LOG(x) (tdb->log_fn?((tdb->log_fn x),0) : 0)
118 #define GLOBAL_LOCK 0
119 #define ACTIVE_LOCK 4
126 #define MAP_FAILED ((void *)-1)
129 /* free memory if the pointer is valid and zero the pointer */
131 #define SAFE_FREE(x) do { if ((x) != NULL) {free((x)); (x)=NULL;} } while(0)
134 #define BUCKET(hash) ((hash) % tdb->header.hash_size)
137 /* all contexts, to ensure no double-opens (fcntl locks don't nest!) */
138 static TDB_CONTEXT
*tdbs
= NULL
;
140 static int tdb_munmap(TDB_CONTEXT
*tdb
)
142 if (tdb
->flags
& TDB_INTERNAL
)
147 int ret
= munmap(tdb
->map_ptr
, tdb
->map_size
);
156 static void tdb_mmap(TDB_CONTEXT
*tdb
)
158 if (tdb
->flags
& TDB_INTERNAL
)
162 if (!(tdb
->flags
& TDB_NOMMAP
)) {
163 tdb
->map_ptr
= mmap(NULL
, tdb
->map_size
,
164 PROT_READ
|(tdb
->read_only
? 0:PROT_WRITE
),
165 MAP_SHARED
|MAP_FILE
, tdb
->fd
, 0);
168 * NB. When mmap fails it returns MAP_FAILED *NOT* NULL !!!!
171 if (tdb
->map_ptr
== MAP_FAILED
) {
173 TDB_LOG((tdb
, 2, "tdb_mmap failed for size %d (%s)\n",
174 tdb
->map_size
, strerror(errno
)));
184 /* Endian conversion: we only ever deal with 4 byte quantities */
185 static void *convert(void *buf
, u32 size
)
188 for (i
= 0; i
< size
/ 4; i
++)
189 p
[i
] = TDB_BYTEREV(p
[i
]);
192 #define DOCONV() (tdb->flags & TDB_CONVERT)
193 #define CONVERT(x) (DOCONV() ? convert(&x, sizeof(x)) : &x)
195 /* the body of the database is made of one list_struct for the free space
196 plus a separate data list for each hash value */
198 tdb_off next
; /* offset of the next record in the list */
199 tdb_len rec_len
; /* total byte length of record */
200 tdb_len key_len
; /* byte length of key */
201 tdb_len data_len
; /* byte length of data */
202 u32 full_hash
; /* the full 32 bit hash of the key */
203 u32 magic
; /* try to catch errors */
204 /* the following union is implied:
206 char record[rec_len];
211 u32 totalsize; (tailer)
216 /***************************************************************
217 Allow a caller to set a "alarm" flag that tdb can check to abort
218 a blocking lock on SIGALRM.
219 ***************************************************************/
221 static sig_atomic_t *palarm_fired
;
223 void tdb_set_lock_alarm(sig_atomic_t *palarm
)
225 palarm_fired
= palarm
;
228 /* a byte range locking function - return 0 on success
229 this functions locks/unlocks 1 byte at the specified offset.
231 On error, errno is also set so that errors are passed back properly
232 through tdb_open(). */
233 static int tdb_brlock(TDB_CONTEXT
*tdb
, tdb_off offset
,
234 int rw_type
, int lck_type
, int probe
)
239 if (tdb
->flags
& TDB_NOLOCK
)
241 if ((rw_type
== F_WRLCK
) && (tdb
->read_only
)) {
247 fl
.l_whence
= SEEK_SET
;
253 ret
= fcntl(tdb
->fd
,lck_type
,&fl
);
254 if (ret
== -1 && errno
== EINTR
&& palarm_fired
&& *palarm_fired
)
256 } while (ret
== -1 && errno
== EINTR
);
259 if (!probe
&& lck_type
!= F_SETLK
) {
260 /* Ensure error code is set for log fun to examine. */
261 if (errno
== EINTR
&& palarm_fired
&& *palarm_fired
)
262 tdb
->ecode
= TDB_ERR_LOCK_TIMEOUT
;
264 tdb
->ecode
= TDB_ERR_LOCK
;
265 TDB_LOG((tdb
, 5,"tdb_brlock failed (fd=%d) at offset %d rw_type=%d lck_type=%d\n",
266 tdb
->fd
, offset
, rw_type
, lck_type
));
268 /* Was it an alarm timeout ? */
269 if (errno
== EINTR
&& palarm_fired
&& *palarm_fired
) {
270 TDB_LOG((tdb
, 5, "tdb_brlock timed out (fd=%d) at offset %d rw_type=%d lck_type=%d\n",
271 tdb
->fd
, offset
, rw_type
, lck_type
));
272 return TDB_ERRCODE(TDB_ERR_LOCK_TIMEOUT
, -1);
274 /* Otherwise - generic lock error. errno set by fcntl.
275 * EAGAIN is an expected return from non-blocking
277 if (errno
!= EAGAIN
) {
278 TDB_LOG((tdb
, 5, "tdb_brlock failed (fd=%d) at offset %d rw_type=%d lck_type=%d: %s\n",
279 tdb
->fd
, offset
, rw_type
, lck_type
,
282 return TDB_ERRCODE(TDB_ERR_LOCK
, -1);
287 /* lock a list in the database. list -1 is the alloc list */
288 static int tdb_lock(TDB_CONTEXT
*tdb
, int list
, int ltype
)
290 if (list
< -1 || list
>= (int)tdb
->header
.hash_size
) {
291 TDB_LOG((tdb
, 0,"tdb_lock: invalid list %d for ltype=%d\n",
295 if (tdb
->flags
& TDB_NOLOCK
)
298 /* Since fcntl locks don't nest, we do a lock for the first one,
299 and simply bump the count for future ones */
300 if (tdb
->locked
[list
+1].count
== 0) {
301 if (!tdb
->read_only
&& tdb
->header
.rwlocks
) {
302 if (tdb_spinlock(tdb
, list
, ltype
)) {
303 TDB_LOG((tdb
, 0, "tdb_lock spinlock failed on list %d ltype=%d\n",
307 } else if (tdb_brlock(tdb
,FREELIST_TOP
+4*list
,ltype
,F_SETLKW
, 0)) {
308 TDB_LOG((tdb
, 0,"tdb_lock failed on list %d ltype=%d (%s)\n",
309 list
, ltype
, strerror(errno
)));
312 tdb
->locked
[list
+1].ltype
= ltype
;
314 tdb
->locked
[list
+1].count
++;
318 /* unlock the database: returns void because it's too late for errors. */
319 /* changed to return int it may be interesting to know there
320 has been an error --simo */
321 static int tdb_unlock(TDB_CONTEXT
*tdb
, int list
, int ltype
)
325 if (tdb
->flags
& TDB_NOLOCK
)
329 if (list
< -1 || list
>= (int)tdb
->header
.hash_size
) {
330 TDB_LOG((tdb
, 0, "tdb_unlock: list %d invalid (%d)\n", list
, tdb
->header
.hash_size
));
334 if (tdb
->locked
[list
+1].count
==0) {
335 TDB_LOG((tdb
, 0, "tdb_unlock: count is 0\n"));
339 if (tdb
->locked
[list
+1].count
== 1) {
340 /* Down to last nested lock: unlock underneath */
341 if (!tdb
->read_only
&& tdb
->header
.rwlocks
) {
342 ret
= tdb_spinunlock(tdb
, list
, ltype
);
344 ret
= tdb_brlock(tdb
, FREELIST_TOP
+4*list
, F_UNLCK
, F_SETLKW
, 0);
349 tdb
->locked
[list
+1].count
--;
352 TDB_LOG((tdb
, 0,"tdb_unlock: An error occurred unlocking!\n"));
356 /* check for an out of bounds access - if it is out of bounds then
357 see if the database has been expanded by someone else and expand
359 note that "len" is the minimum length needed for the db
361 static int tdb_oob(TDB_CONTEXT
*tdb
, tdb_off len
, int probe
)
364 if (len
<= tdb
->map_size
)
366 if (tdb
->flags
& TDB_INTERNAL
) {
368 /* Ensure ecode is set for log fn. */
369 tdb
->ecode
= TDB_ERR_IO
;
370 TDB_LOG((tdb
, 0,"tdb_oob len %d beyond internal malloc size %d\n",
371 (int)len
, (int)tdb
->map_size
));
373 return TDB_ERRCODE(TDB_ERR_IO
, -1);
376 if (fstat(tdb
->fd
, &st
) == -1)
377 return TDB_ERRCODE(TDB_ERR_IO
, -1);
379 if (st
.st_size
< (size_t)len
) {
381 /* Ensure ecode is set for log fn. */
382 tdb
->ecode
= TDB_ERR_IO
;
383 TDB_LOG((tdb
, 0,"tdb_oob len %d beyond eof at %d\n",
384 (int)len
, (int)st
.st_size
));
386 return TDB_ERRCODE(TDB_ERR_IO
, -1);
389 /* Unmap, update size, remap */
390 if (tdb_munmap(tdb
) == -1)
391 return TDB_ERRCODE(TDB_ERR_IO
, -1);
392 tdb
->map_size
= st
.st_size
;
397 /* write a lump of data at a specified offset */
398 static int tdb_write(TDB_CONTEXT
*tdb
, tdb_off off
, void *buf
, tdb_len len
)
400 if (tdb_oob(tdb
, off
+ len
, 0) != 0)
404 memcpy(off
+ (char *)tdb
->map_ptr
, buf
, len
);
406 else if (pwrite(tdb
->fd
, buf
, len
, off
) != (ssize_t
)len
) {
408 else if (lseek(tdb
->fd
, off
, SEEK_SET
) != off
409 || write(tdb
->fd
, buf
, len
) != (ssize_t
)len
) {
411 /* Ensure ecode is set for log fn. */
412 tdb
->ecode
= TDB_ERR_IO
;
413 TDB_LOG((tdb
, 0,"tdb_write failed at %d len=%d (%s)\n",
414 off
, len
, strerror(errno
)));
415 return TDB_ERRCODE(TDB_ERR_IO
, -1);
420 /* read a lump of data at a specified offset, maybe convert */
421 static int tdb_read(TDB_CONTEXT
*tdb
,tdb_off off
,void *buf
,tdb_len len
,int cv
)
423 if (tdb_oob(tdb
, off
+ len
, 0) != 0)
427 memcpy(buf
, off
+ (char *)tdb
->map_ptr
, len
);
429 else if (pread(tdb
->fd
, buf
, len
, off
) != (ssize_t
)len
) {
431 else if (lseek(tdb
->fd
, off
, SEEK_SET
) != off
432 || read(tdb
->fd
, buf
, len
) != (ssize_t
)len
) {
434 /* Ensure ecode is set for log fn. */
435 tdb
->ecode
= TDB_ERR_IO
;
436 TDB_LOG((tdb
, 0,"tdb_read failed at %d len=%d (%s)\n",
437 off
, len
, strerror(errno
)));
438 return TDB_ERRCODE(TDB_ERR_IO
, -1);
445 /* read a lump of data, allocating the space for it */
446 static char *tdb_alloc_read(TDB_CONTEXT
*tdb
, tdb_off offset
, tdb_len len
)
450 if (!(buf
= malloc(len
))) {
451 /* Ensure ecode is set for log fn. */
452 tdb
->ecode
= TDB_ERR_OOM
;
453 TDB_LOG((tdb
, 0,"tdb_alloc_read malloc failed len=%d (%s)\n",
454 len
, strerror(errno
)));
455 return TDB_ERRCODE(TDB_ERR_OOM
, buf
);
457 if (tdb_read(tdb
, offset
, buf
, len
, 0) == -1) {
464 /* read/write a tdb_off */
465 static int ofs_read(TDB_CONTEXT
*tdb
, tdb_off offset
, tdb_off
*d
)
467 return tdb_read(tdb
, offset
, (char*)d
, sizeof(*d
), DOCONV());
469 static int ofs_write(TDB_CONTEXT
*tdb
, tdb_off offset
, tdb_off
*d
)
472 return tdb_write(tdb
, offset
, CONVERT(off
), sizeof(*d
));
475 /* read/write a record */
476 static int rec_read(TDB_CONTEXT
*tdb
, tdb_off offset
, struct list_struct
*rec
)
478 if (tdb_read(tdb
, offset
, rec
, sizeof(*rec
),DOCONV()) == -1)
480 if (TDB_BAD_MAGIC(rec
)) {
481 /* Ensure ecode is set for log fn. */
482 tdb
->ecode
= TDB_ERR_CORRUPT
;
483 TDB_LOG((tdb
, 0,"rec_read bad magic 0x%x at offset=%d\n", rec
->magic
, offset
));
484 return TDB_ERRCODE(TDB_ERR_CORRUPT
, -1);
486 return tdb_oob(tdb
, rec
->next
+sizeof(*rec
), 0);
488 static int rec_write(TDB_CONTEXT
*tdb
, tdb_off offset
, struct list_struct
*rec
)
490 struct list_struct r
= *rec
;
491 return tdb_write(tdb
, offset
, CONVERT(r
), sizeof(r
));
494 /* read a freelist record and check for simple errors */
495 static int rec_free_read(TDB_CONTEXT
*tdb
, tdb_off off
, struct list_struct
*rec
)
497 if (tdb_read(tdb
, off
, rec
, sizeof(*rec
),DOCONV()) == -1)
500 if (rec
->magic
== TDB_MAGIC
) {
501 /* this happens when a app is showdown while deleting a record - we should
502 not completely fail when this happens */
503 TDB_LOG((tdb
, 0,"rec_free_read non-free magic 0x%x at offset=%d - fixing\n",
505 rec
->magic
= TDB_FREE_MAGIC
;
506 if (tdb_write(tdb
, off
, rec
, sizeof(*rec
)) == -1)
510 if (rec
->magic
!= TDB_FREE_MAGIC
) {
511 /* Ensure ecode is set for log fn. */
512 tdb
->ecode
= TDB_ERR_CORRUPT
;
513 TDB_LOG((tdb
, 0,"rec_free_read bad magic 0x%x at offset=%d\n",
515 return TDB_ERRCODE(TDB_ERR_CORRUPT
, -1);
517 if (tdb_oob(tdb
, rec
->next
+sizeof(*rec
), 0) != 0)
522 /* update a record tailer (must hold allocation lock) */
523 static int update_tailer(TDB_CONTEXT
*tdb
, tdb_off offset
,
524 const struct list_struct
*rec
)
528 /* Offset of tailer from record header */
529 totalsize
= sizeof(*rec
) + rec
->rec_len
;
530 return ofs_write(tdb
, offset
+ totalsize
- sizeof(tdb_off
),
534 static tdb_off
tdb_dump_record(TDB_CONTEXT
*tdb
, tdb_off offset
)
536 struct list_struct rec
;
537 tdb_off tailer_ofs
, tailer
;
539 if (tdb_read(tdb
, offset
, (char *)&rec
, sizeof(rec
), DOCONV()) == -1) {
540 printf("ERROR: failed to read record at %u\n", offset
);
544 printf(" rec: offset=%u next=%d rec_len=%d key_len=%d data_len=%d full_hash=0x%x magic=0x%x\n",
545 offset
, rec
.next
, rec
.rec_len
, rec
.key_len
, rec
.data_len
, rec
.full_hash
, rec
.magic
);
547 tailer_ofs
= offset
+ sizeof(rec
) + rec
.rec_len
- sizeof(tdb_off
);
548 if (ofs_read(tdb
, tailer_ofs
, &tailer
) == -1) {
549 printf("ERROR: failed to read tailer at %u\n", tailer_ofs
);
553 if (tailer
!= rec
.rec_len
+ sizeof(rec
)) {
554 printf("ERROR: tailer does not match record! tailer=%u totalsize=%u\n",
555 (unsigned)tailer
, (unsigned)(rec
.rec_len
+ sizeof(rec
)));
560 static int tdb_dump_chain(TDB_CONTEXT
*tdb
, int i
)
562 tdb_off rec_ptr
, top
;
564 top
= TDB_HASH_TOP(i
);
566 if (tdb_lock(tdb
, i
, F_WRLCK
) != 0)
569 if (ofs_read(tdb
, top
, &rec_ptr
) == -1)
570 return tdb_unlock(tdb
, i
, F_WRLCK
);
573 printf("hash=%d\n", i
);
576 rec_ptr
= tdb_dump_record(tdb
, rec_ptr
);
579 return tdb_unlock(tdb
, i
, F_WRLCK
);
582 void tdb_dump_all(TDB_CONTEXT
*tdb
)
585 for (i
=0;i
<tdb
->header
.hash_size
;i
++) {
586 tdb_dump_chain(tdb
, i
);
588 tdb_printfreelist(tdb
);
591 int tdb_printfreelist(TDB_CONTEXT
*tdb
)
595 tdb_off offset
, rec_ptr
;
596 struct list_struct rec
;
598 if ((ret
= tdb_lock(tdb
, -1, F_WRLCK
)) != 0)
601 offset
= FREELIST_TOP
;
603 /* read in the freelist top */
604 if (ofs_read(tdb
, offset
, &rec_ptr
) == -1) {
605 tdb_unlock(tdb
, -1, F_WRLCK
);
609 printf("freelist top=[0x%08x]\n", rec_ptr
);
611 if (tdb_read(tdb
, rec_ptr
, (char *)&rec
, sizeof(rec
), DOCONV()) == -1) {
612 tdb_unlock(tdb
, -1, F_WRLCK
);
616 if (rec
.magic
!= TDB_FREE_MAGIC
) {
617 printf("bad magic 0x%08x in free list\n", rec
.magic
);
618 tdb_unlock(tdb
, -1, F_WRLCK
);
622 printf("entry offset=[0x%08x], rec.rec_len = [0x%08x (%d)]\n", rec
.next
, rec
.rec_len
, rec
.rec_len
);
623 total_free
+= rec
.rec_len
;
625 /* move to the next record */
628 printf("total rec_len = [0x%08x (%d)]\n", (int)total_free
,
631 return tdb_unlock(tdb
, -1, F_WRLCK
);
634 /* Remove an element from the freelist. Must have alloc lock. */
635 static int remove_from_freelist(TDB_CONTEXT
*tdb
, tdb_off off
, tdb_off next
)
639 /* read in the freelist top */
640 last_ptr
= FREELIST_TOP
;
641 while (ofs_read(tdb
, last_ptr
, &i
) != -1 && i
!= 0) {
643 /* We've found it! */
644 return ofs_write(tdb
, last_ptr
, &next
);
646 /* Follow chain (next offset is at start of record) */
649 TDB_LOG((tdb
, 0,"remove_from_freelist: not on list at off=%d\n", off
));
650 return TDB_ERRCODE(TDB_ERR_CORRUPT
, -1);
653 /* Add an element into the freelist. Merge adjacent records if
655 static int tdb_free(TDB_CONTEXT
*tdb
, tdb_off offset
, struct list_struct
*rec
)
659 /* Allocation and tailer lock */
660 if (tdb_lock(tdb
, -1, F_WRLCK
) != 0)
663 /* set an initial tailer, so if we fail we don't leave a bogus record */
664 if (update_tailer(tdb
, offset
, rec
) != 0) {
665 TDB_LOG((tdb
, 0, "tdb_free: upfate_tailer failed!\n"));
669 /* Look right first (I'm an Australian, dammit) */
670 right
= offset
+ sizeof(*rec
) + rec
->rec_len
;
671 if (right
+ sizeof(*rec
) <= tdb
->map_size
) {
672 struct list_struct r
;
674 if (tdb_read(tdb
, right
, &r
, sizeof(r
), DOCONV()) == -1) {
675 TDB_LOG((tdb
, 0, "tdb_free: right read failed at %u\n", right
));
679 /* If it's free, expand to include it. */
680 if (r
.magic
== TDB_FREE_MAGIC
) {
681 if (remove_from_freelist(tdb
, right
, r
.next
) == -1) {
682 TDB_LOG((tdb
, 0, "tdb_free: right free failed at %u\n", right
));
685 rec
->rec_len
+= sizeof(r
) + r
.rec_len
;
691 left
= offset
- sizeof(tdb_off
);
692 if (left
> TDB_DATA_START(tdb
->header
.hash_size
)) {
693 struct list_struct l
;
696 /* Read in tailer and jump back to header */
697 if (ofs_read(tdb
, left
, &leftsize
) == -1) {
698 TDB_LOG((tdb
, 0, "tdb_free: left offset read failed at %u\n", left
));
701 left
= offset
- leftsize
;
703 /* Now read in record */
704 if (tdb_read(tdb
, left
, &l
, sizeof(l
), DOCONV()) == -1) {
705 TDB_LOG((tdb
, 0, "tdb_free: left read failed at %u (%u)\n", left
, leftsize
));
709 /* If it's free, expand to include it. */
710 if (l
.magic
== TDB_FREE_MAGIC
) {
711 if (remove_from_freelist(tdb
, left
, l
.next
) == -1) {
712 TDB_LOG((tdb
, 0, "tdb_free: left free failed at %u\n", left
));
716 rec
->rec_len
+= leftsize
;
722 if (update_tailer(tdb
, offset
, rec
) == -1) {
723 TDB_LOG((tdb
, 0, "tdb_free: update_tailer failed at %u\n", offset
));
727 /* Now, prepend to free list */
728 rec
->magic
= TDB_FREE_MAGIC
;
730 if (ofs_read(tdb
, FREELIST_TOP
, &rec
->next
) == -1 ||
731 rec_write(tdb
, offset
, rec
) == -1 ||
732 ofs_write(tdb
, FREELIST_TOP
, &offset
) == -1) {
733 TDB_LOG((tdb
, 0, "tdb_free record write failed at offset=%d\n", offset
));
737 /* And we're done. */
738 tdb_unlock(tdb
, -1, F_WRLCK
);
742 tdb_unlock(tdb
, -1, F_WRLCK
);
747 /* expand a file. we prefer to use ftruncate, as that is what posix
748 says to use for mmap expansion */
749 static int expand_file(TDB_CONTEXT
*tdb
, tdb_off size
, tdb_off addition
)
752 #if HAVE_FTRUNCATE_EXTEND
753 if (ftruncate(tdb
->fd
, size
+addition
) != 0) {
754 TDB_LOG((tdb
, 0, "expand_file ftruncate to %d failed (%s)\n",
755 size
+addition
, strerror(errno
)));
762 if (pwrite(tdb
->fd
, &b
, 1, (size
+addition
) - 1) != 1) {
764 if (lseek(tdb
->fd
, (size
+addition
) - 1, SEEK_SET
) != (size
+addition
) - 1 ||
765 write(tdb
->fd
, &b
, 1) != 1) {
767 TDB_LOG((tdb
, 0, "expand_file to %d failed (%s)\n",
768 size
+addition
, strerror(errno
)));
773 /* now fill the file with something. This ensures that the file isn't sparse, which would be
774 very bad if we ran out of disk. This must be done with write, not via mmap */
775 memset(buf
, 0x42, sizeof(buf
));
777 int n
= addition
>sizeof(buf
)?sizeof(buf
):addition
;
779 int ret
= pwrite(tdb
->fd
, buf
, n
, size
);
782 if (lseek(tdb
->fd
, size
, SEEK_SET
) != size
)
784 ret
= write(tdb
->fd
, buf
, n
);
787 TDB_LOG((tdb
, 0, "expand_file write of %d failed (%s)\n",
788 n
, strerror(errno
)));
798 /* expand the database at least size bytes by expanding the underlying
799 file and doing the mmap again if necessary */
800 static int tdb_expand(TDB_CONTEXT
*tdb
, tdb_off size
)
802 struct list_struct rec
;
805 if (tdb_lock(tdb
, -1, F_WRLCK
) == -1) {
806 TDB_LOG((tdb
, 0, "lock failed in tdb_expand\n"));
810 /* must know about any previous expansions by another process */
811 tdb_oob(tdb
, tdb
->map_size
+ 1, 1);
813 /* always make room for at least 10 more records, and round
814 the database up to a multiple of TDB_PAGE_SIZE */
815 size
= TDB_ALIGN(tdb
->map_size
+ size
*10, TDB_PAGE_SIZE
) - tdb
->map_size
;
817 if (!(tdb
->flags
& TDB_INTERNAL
))
821 * We must ensure the file is unmapped before doing this
822 * to ensure consistency with systems like OpenBSD where
823 * writes and mmaps are not consistent.
826 /* expand the file itself */
827 if (!(tdb
->flags
& TDB_INTERNAL
)) {
828 if (expand_file(tdb
, tdb
->map_size
, size
) != 0)
832 tdb
->map_size
+= size
;
834 if (tdb
->flags
& TDB_INTERNAL
) {
835 char *new_map_ptr
= realloc(tdb
->map_ptr
, tdb
->map_size
);
837 tdb
->map_size
-= size
;
840 tdb
->map_ptr
= new_map_ptr
;
843 * We must ensure the file is remapped before adding the space
844 * to ensure consistency with systems like OpenBSD where
845 * writes and mmaps are not consistent.
848 /* We're ok if the mmap fails as we'll fallback to read/write */
852 /* form a new freelist record */
853 memset(&rec
,'\0',sizeof(rec
));
854 rec
.rec_len
= size
- sizeof(rec
);
856 /* link it into the free list */
857 offset
= tdb
->map_size
- size
;
858 if (tdb_free(tdb
, offset
, &rec
) == -1)
861 tdb_unlock(tdb
, -1, F_WRLCK
);
864 tdb_unlock(tdb
, -1, F_WRLCK
);
868 /* allocate some space from the free list. The offset returned points
869 to a unconnected list_struct within the database with room for at
870 least length bytes of total data
872 0 is returned if the space could not be allocated
874 static tdb_off
tdb_allocate(TDB_CONTEXT
*tdb
, tdb_len length
,
875 struct list_struct
*rec
)
877 tdb_off rec_ptr
, last_ptr
, newrec_ptr
;
878 struct list_struct newrec
;
880 memset(&newrec
, '\0', sizeof(newrec
));
882 if (tdb_lock(tdb
, -1, F_WRLCK
) == -1)
885 /* Extra bytes required for tailer */
886 length
+= sizeof(tdb_off
);
889 last_ptr
= FREELIST_TOP
;
891 /* read in the freelist top */
892 if (ofs_read(tdb
, FREELIST_TOP
, &rec_ptr
) == -1)
895 /* keep looking until we find a freelist record big enough */
897 if (rec_free_read(tdb
, rec_ptr
, rec
) == -1)
900 if (rec
->rec_len
>= length
) {
901 /* found it - now possibly split it up */
902 if (rec
->rec_len
> length
+ MIN_REC_SIZE
) {
903 /* Length of left piece */
904 length
= TDB_ALIGN(length
, TDB_ALIGNMENT
);
906 /* Right piece to go on free list */
907 newrec
.rec_len
= rec
->rec_len
908 - (sizeof(*rec
) + length
);
909 newrec_ptr
= rec_ptr
+ sizeof(*rec
) + length
;
911 /* And left record is shortened */
912 rec
->rec_len
= length
;
916 /* Remove allocated record from the free list */
917 if (ofs_write(tdb
, last_ptr
, &rec
->next
) == -1)
920 /* Update header: do this before we drop alloc
921 lock, otherwise tdb_free() might try to
922 merge with us, thinking we're free.
923 (Thanks Jeremy Allison). */
924 rec
->magic
= TDB_MAGIC
;
925 if (rec_write(tdb
, rec_ptr
, rec
) == -1)
928 /* Did we create new block? */
930 /* Update allocated record tailer (we
932 if (update_tailer(tdb
, rec_ptr
, rec
) == -1)
935 /* Free new record */
936 if (tdb_free(tdb
, newrec_ptr
, &newrec
) == -1)
940 /* all done - return the new record offset */
941 tdb_unlock(tdb
, -1, F_WRLCK
);
944 /* move to the next record */
948 /* we didn't find enough space. See if we can expand the
949 database and if we can then try again */
950 if (tdb_expand(tdb
, length
+ sizeof(*rec
)) == 0)
953 tdb_unlock(tdb
, -1, F_WRLCK
);
957 /* initialise a new database with a specified hash size */
958 static int tdb_new_database(TDB_CONTEXT
*tdb
, int hash_size
)
960 struct tdb_header
*newdb
;
963 /* We make it up in memory, then write it out if not internal */
964 size
= sizeof(struct tdb_header
) + (hash_size
+1)*sizeof(tdb_off
);
965 if (!(newdb
= calloc(size
, 1)))
966 return TDB_ERRCODE(TDB_ERR_OOM
, -1);
968 /* Fill in the header */
969 newdb
->version
= TDB_VERSION
;
970 newdb
->hash_size
= hash_size
;
972 newdb
->rwlocks
= size
;
974 if (tdb
->flags
& TDB_INTERNAL
) {
975 tdb
->map_size
= size
;
976 tdb
->map_ptr
= (char *)newdb
;
977 memcpy(&tdb
->header
, newdb
, sizeof(tdb
->header
));
978 /* Convert the `ondisk' version if asked. */
982 if (lseek(tdb
->fd
, 0, SEEK_SET
) == -1)
985 if (ftruncate(tdb
->fd
, 0) == -1)
988 /* This creates an endian-converted header, as if read from disk */
990 memcpy(&tdb
->header
, newdb
, sizeof(tdb
->header
));
991 /* Don't endian-convert the magic food! */
992 memcpy(newdb
->magic_food
, TDB_MAGIC_FOOD
, strlen(TDB_MAGIC_FOOD
)+1);
993 if (write(tdb
->fd
, newdb
, size
) != size
)
996 ret
= tdb_create_rwlocks(tdb
->fd
, hash_size
);
1003 /* Returns 0 on fail. On success, return offset of record, and fills
1005 static tdb_off
tdb_find(TDB_CONTEXT
*tdb
, TDB_DATA key
, u32 hash
,
1006 struct list_struct
*r
)
1010 /* read in the hash top */
1011 if (ofs_read(tdb
, TDB_HASH_TOP(hash
), &rec_ptr
) == -1)
1014 /* keep looking until we find the right record */
1016 if (rec_read(tdb
, rec_ptr
, r
) == -1)
1019 if (!TDB_DEAD(r
) && hash
==r
->full_hash
&& key
.dsize
==r
->key_len
) {
1021 /* a very likely hit - read the key */
1022 k
= tdb_alloc_read(tdb
, rec_ptr
+ sizeof(*r
),
1027 if (memcmp(key
.dptr
, k
, key
.dsize
) == 0) {
1035 return TDB_ERRCODE(TDB_ERR_NOEXIST
, 0);
1038 /* As tdb_find, but if you succeed, keep the lock */
1039 static tdb_off
tdb_find_lock_hash(TDB_CONTEXT
*tdb
, TDB_DATA key
, u32 hash
, int locktype
,
1040 struct list_struct
*rec
)
1044 if (tdb_lock(tdb
, BUCKET(hash
), locktype
) == -1)
1046 if (!(rec_ptr
= tdb_find(tdb
, key
, hash
, rec
)))
1047 tdb_unlock(tdb
, BUCKET(hash
), locktype
);
1051 enum TDB_ERROR
tdb_error(TDB_CONTEXT
*tdb
)
1056 static struct tdb_errname
{
1057 enum TDB_ERROR ecode
; const char *estring
;
1058 } emap
[] = { {TDB_SUCCESS
, "Success"},
1059 {TDB_ERR_CORRUPT
, "Corrupt database"},
1060 {TDB_ERR_IO
, "IO Error"},
1061 {TDB_ERR_LOCK
, "Locking error"},
1062 {TDB_ERR_OOM
, "Out of memory"},
1063 {TDB_ERR_EXISTS
, "Record exists"},
1064 {TDB_ERR_NOLOCK
, "Lock exists on other keys"},
1065 {TDB_ERR_NOEXIST
, "Record does not exist"} };
1067 /* Error string for the last tdb error */
1068 const char *tdb_errorstr(TDB_CONTEXT
*tdb
)
1071 for (i
= 0; i
< sizeof(emap
) / sizeof(struct tdb_errname
); i
++)
1072 if (tdb
->ecode
== emap
[i
].ecode
)
1073 return emap
[i
].estring
;
1074 return "Invalid error code";
1077 /* update an entry in place - this only works if the new data size
1078 is <= the old data size and the key exists.
1079 on failure return -1.
1082 static int tdb_update_hash(TDB_CONTEXT
*tdb
, TDB_DATA key
, u32 hash
, TDB_DATA dbuf
)
1084 struct list_struct rec
;
1088 if (!(rec_ptr
= tdb_find(tdb
, key
, hash
, &rec
)))
1091 /* must be long enough key, data and tailer */
1092 if (rec
.rec_len
< key
.dsize
+ dbuf
.dsize
+ sizeof(tdb_off
)) {
1093 tdb
->ecode
= TDB_SUCCESS
; /* Not really an error */
1097 if (tdb_write(tdb
, rec_ptr
+ sizeof(rec
) + rec
.key_len
,
1098 dbuf
.dptr
, dbuf
.dsize
) == -1)
1101 if (dbuf
.dsize
!= rec
.data_len
) {
1103 rec
.data_len
= dbuf
.dsize
;
1104 return rec_write(tdb
, rec_ptr
, &rec
);
1110 /* find an entry in the database given a key */
1111 /* If an entry doesn't exist tdb_err will be set to
1112 * TDB_ERR_NOEXIST. If a key has no data attached
1113 * tdb_err will not be set. Both will return a
1114 * zero pptr and zero dsize.
1117 TDB_DATA
tdb_fetch(TDB_CONTEXT
*tdb
, TDB_DATA key
)
1120 struct list_struct rec
;
1124 /* find which hash bucket it is in */
1125 hash
= tdb
->hash_fn(&key
);
1126 if (!(rec_ptr
= tdb_find_lock_hash(tdb
,key
,hash
,F_RDLCK
,&rec
)))
1130 ret
.dptr
= tdb_alloc_read(tdb
, rec_ptr
+ sizeof(rec
) + rec
.key_len
,
1134 ret
.dsize
= rec
.data_len
;
1135 tdb_unlock(tdb
, BUCKET(rec
.full_hash
), F_RDLCK
);
1139 /* check if an entry in the database exists
1141 note that 1 is returned if the key is found and 0 is returned if not found
1142 this doesn't match the conventions in the rest of this module, but is
1143 compatible with gdbm
1145 static int tdb_exists_hash(TDB_CONTEXT
*tdb
, TDB_DATA key
, u32 hash
)
1147 struct list_struct rec
;
1149 if (tdb_find_lock_hash(tdb
, key
, hash
, F_RDLCK
, &rec
) == 0)
1151 tdb_unlock(tdb
, BUCKET(rec
.full_hash
), F_RDLCK
);
1155 int tdb_exists(TDB_CONTEXT
*tdb
, TDB_DATA key
)
1157 u32 hash
= tdb
->hash_fn(&key
);
1158 return tdb_exists_hash(tdb
, key
, hash
);
1161 /* record lock stops delete underneath */
1162 static int lock_record(TDB_CONTEXT
*tdb
, tdb_off off
)
1164 return off
? tdb_brlock(tdb
, off
, F_RDLCK
, F_SETLKW
, 0) : 0;
1167 Write locks override our own fcntl readlocks, so check it here.
1168 Note this is meant to be F_SETLK, *not* F_SETLKW, as it's not
1169 an error to fail to get the lock here.
1172 static int write_lock_record(TDB_CONTEXT
*tdb
, tdb_off off
)
1174 struct tdb_traverse_lock
*i
;
1175 for (i
= &tdb
->travlocks
; i
; i
= i
->next
)
1178 return tdb_brlock(tdb
, off
, F_WRLCK
, F_SETLK
, 1);
1182 Note this is meant to be F_SETLK, *not* F_SETLKW, as it's not
1183 an error to fail to get the lock here.
1186 static int write_unlock_record(TDB_CONTEXT
*tdb
, tdb_off off
)
1188 return tdb_brlock(tdb
, off
, F_UNLCK
, F_SETLK
, 0);
1190 /* fcntl locks don't stack: avoid unlocking someone else's */
1191 static int unlock_record(TDB_CONTEXT
*tdb
, tdb_off off
)
1193 struct tdb_traverse_lock
*i
;
1198 for (i
= &tdb
->travlocks
; i
; i
= i
->next
)
1201 return (count
== 1 ? tdb_brlock(tdb
, off
, F_UNLCK
, F_SETLKW
, 0) : 0);
1204 /* actually delete an entry in the database given the offset */
1205 static int do_delete(TDB_CONTEXT
*tdb
, tdb_off rec_ptr
, struct list_struct
*rec
)
1207 tdb_off last_ptr
, i
;
1208 struct list_struct lastrec
;
1210 if (tdb
->read_only
) return -1;
1212 if (write_lock_record(tdb
, rec_ptr
) == -1) {
1213 /* Someone traversing here: mark it as dead */
1214 rec
->magic
= TDB_DEAD_MAGIC
;
1215 return rec_write(tdb
, rec_ptr
, rec
);
1217 if (write_unlock_record(tdb
, rec_ptr
) != 0)
1220 /* find previous record in hash chain */
1221 if (ofs_read(tdb
, TDB_HASH_TOP(rec
->full_hash
), &i
) == -1)
1223 for (last_ptr
= 0; i
!= rec_ptr
; last_ptr
= i
, i
= lastrec
.next
)
1224 if (rec_read(tdb
, i
, &lastrec
) == -1)
1227 /* unlink it: next ptr is at start of record. */
1229 last_ptr
= TDB_HASH_TOP(rec
->full_hash
);
1230 if (ofs_write(tdb
, last_ptr
, &rec
->next
) == -1)
1233 /* recover the space */
1234 if (tdb_free(tdb
, rec_ptr
, rec
) == -1)
1239 /* Uses traverse lock: 0 = finish, -1 = error, other = record offset */
1240 static int tdb_next_lock(TDB_CONTEXT
*tdb
, struct tdb_traverse_lock
*tlock
,
1241 struct list_struct
*rec
)
1243 int want_next
= (tlock
->off
!= 0);
1245 /* Lock each chain from the start one. */
1246 for (; tlock
->hash
< tdb
->header
.hash_size
; tlock
->hash
++) {
1247 if (tdb_lock(tdb
, tlock
->hash
, F_WRLCK
) == -1)
1250 /* No previous record? Start at top of chain. */
1252 if (ofs_read(tdb
, TDB_HASH_TOP(tlock
->hash
),
1256 /* Otherwise unlock the previous record. */
1257 if (unlock_record(tdb
, tlock
->off
) != 0)
1262 /* We have offset of old record: grab next */
1263 if (rec_read(tdb
, tlock
->off
, rec
) == -1)
1265 tlock
->off
= rec
->next
;
1268 /* Iterate through chain */
1269 while( tlock
->off
) {
1271 if (rec_read(tdb
, tlock
->off
, rec
) == -1)
1274 /* Detect infinite loops. From "Shlomi Yaakobovich" <Shlomi@exanet.com>. */
1275 if (tlock
->off
== rec
->next
) {
1276 TDB_LOG((tdb
, 0, "tdb_next_lock: loop detected.\n"));
1280 if (!TDB_DEAD(rec
)) {
1281 /* Woohoo: we found one! */
1282 if (lock_record(tdb
, tlock
->off
) != 0)
1287 /* Try to clean dead ones from old traverses */
1288 current
= tlock
->off
;
1289 tlock
->off
= rec
->next
;
1290 if (!tdb
->read_only
&&
1291 do_delete(tdb
, current
, rec
) != 0)
1294 tdb_unlock(tdb
, tlock
->hash
, F_WRLCK
);
1297 /* We finished iteration without finding anything */
1298 return TDB_ERRCODE(TDB_SUCCESS
, 0);
1302 if (tdb_unlock(tdb
, tlock
->hash
, F_WRLCK
) != 0)
1303 TDB_LOG((tdb
, 0, "tdb_next_lock: On error unlock failed!\n"));
1307 /* traverse the entire database - calling fn(tdb, key, data) on each element.
1308 return -1 on error or the record count traversed
1309 if fn is NULL then it is not called
1310 a non-zero return value from fn() indicates that the traversal should stop
1312 int tdb_traverse(TDB_CONTEXT
*tdb
, tdb_traverse_func fn
, void *private)
1315 struct list_struct rec
;
1316 struct tdb_traverse_lock tl
= { NULL
, 0, 0 };
1319 /* This was in the initializaton, above, but the IRIX compiler
1320 * did not like it. crh
1322 tl
.next
= tdb
->travlocks
.next
;
1324 /* fcntl locks don't stack: beware traverse inside traverse */
1325 tdb
->travlocks
.next
= &tl
;
1327 /* tdb_next_lock places locks on the record returned, and its chain */
1328 while ((ret
= tdb_next_lock(tdb
, &tl
, &rec
)) > 0) {
1330 /* now read the full record */
1331 key
.dptr
= tdb_alloc_read(tdb
, tl
.off
+ sizeof(rec
),
1332 rec
.key_len
+ rec
.data_len
);
1335 if (tdb_unlock(tdb
, tl
.hash
, F_WRLCK
) != 0)
1337 if (unlock_record(tdb
, tl
.off
) != 0)
1338 TDB_LOG((tdb
, 0, "tdb_traverse: key.dptr == NULL and unlock_record failed!\n"));
1341 key
.dsize
= rec
.key_len
;
1342 dbuf
.dptr
= key
.dptr
+ rec
.key_len
;
1343 dbuf
.dsize
= rec
.data_len
;
1345 /* Drop chain lock, call out */
1346 if (tdb_unlock(tdb
, tl
.hash
, F_WRLCK
) != 0) {
1350 if (fn
&& fn(tdb
, key
, dbuf
, private)) {
1351 /* They want us to terminate traversal */
1353 if (unlock_record(tdb
, tl
.off
) != 0) {
1354 TDB_LOG((tdb
, 0, "tdb_traverse: unlock_record failed!\n"));;
1357 tdb
->travlocks
.next
= tl
.next
;
1358 SAFE_FREE(key
.dptr
);
1361 SAFE_FREE(key
.dptr
);
1364 tdb
->travlocks
.next
= tl
.next
;
1371 /* find the first entry in the database and return its key */
1372 TDB_DATA
tdb_firstkey(TDB_CONTEXT
*tdb
)
1375 struct list_struct rec
;
1377 /* release any old lock */
1378 if (unlock_record(tdb
, tdb
->travlocks
.off
) != 0)
1380 tdb
->travlocks
.off
= tdb
->travlocks
.hash
= 0;
1382 if (tdb_next_lock(tdb
, &tdb
->travlocks
, &rec
) <= 0)
1384 /* now read the key */
1385 key
.dsize
= rec
.key_len
;
1386 key
.dptr
=tdb_alloc_read(tdb
,tdb
->travlocks
.off
+sizeof(rec
),key
.dsize
);
1387 if (tdb_unlock(tdb
, BUCKET(tdb
->travlocks
.hash
), F_WRLCK
) != 0)
1388 TDB_LOG((tdb
, 0, "tdb_firstkey: error occurred while tdb_unlocking!\n"));
1392 /* find the next entry in the database, returning its key */
1393 TDB_DATA
tdb_nextkey(TDB_CONTEXT
*tdb
, TDB_DATA oldkey
)
1396 TDB_DATA key
= tdb_null
;
1397 struct list_struct rec
;
1400 /* Is locked key the old key? If so, traverse will be reliable. */
1401 if (tdb
->travlocks
.off
) {
1402 if (tdb_lock(tdb
,tdb
->travlocks
.hash
,F_WRLCK
))
1404 if (rec_read(tdb
, tdb
->travlocks
.off
, &rec
) == -1
1405 || !(k
= tdb_alloc_read(tdb
,tdb
->travlocks
.off
+sizeof(rec
),
1407 || memcmp(k
, oldkey
.dptr
, oldkey
.dsize
) != 0) {
1408 /* No, it wasn't: unlock it and start from scratch */
1409 if (unlock_record(tdb
, tdb
->travlocks
.off
) != 0)
1411 if (tdb_unlock(tdb
, tdb
->travlocks
.hash
, F_WRLCK
) != 0)
1413 tdb
->travlocks
.off
= 0;
1419 if (!tdb
->travlocks
.off
) {
1420 /* No previous element: do normal find, and lock record */
1421 tdb
->travlocks
.off
= tdb_find_lock_hash(tdb
, oldkey
, tdb
->hash_fn(&oldkey
), F_WRLCK
, &rec
);
1422 if (!tdb
->travlocks
.off
)
1424 tdb
->travlocks
.hash
= BUCKET(rec
.full_hash
);
1425 if (lock_record(tdb
, tdb
->travlocks
.off
) != 0) {
1426 TDB_LOG((tdb
, 0, "tdb_nextkey: lock_record failed (%s)!\n", strerror(errno
)));
1430 oldhash
= tdb
->travlocks
.hash
;
1432 /* Grab next record: locks chain and returned record,
1433 unlocks old record */
1434 if (tdb_next_lock(tdb
, &tdb
->travlocks
, &rec
) > 0) {
1435 key
.dsize
= rec
.key_len
;
1436 key
.dptr
= tdb_alloc_read(tdb
, tdb
->travlocks
.off
+sizeof(rec
),
1438 /* Unlock the chain of this new record */
1439 if (tdb_unlock(tdb
, tdb
->travlocks
.hash
, F_WRLCK
) != 0)
1440 TDB_LOG((tdb
, 0, "tdb_nextkey: WARNING tdb_unlock failed!\n"));
1442 /* Unlock the chain of old record */
1443 if (tdb_unlock(tdb
, BUCKET(oldhash
), F_WRLCK
) != 0)
1444 TDB_LOG((tdb
, 0, "tdb_nextkey: WARNING tdb_unlock failed!\n"));
1448 /* delete an entry in the database given a key */
1449 static int tdb_delete_hash(TDB_CONTEXT
*tdb
, TDB_DATA key
, u32 hash
)
1452 struct list_struct rec
;
1455 if (!(rec_ptr
= tdb_find_lock_hash(tdb
, key
, hash
, F_WRLCK
, &rec
)))
1457 ret
= do_delete(tdb
, rec_ptr
, &rec
);
1458 if (tdb_unlock(tdb
, BUCKET(rec
.full_hash
), F_WRLCK
) != 0)
1459 TDB_LOG((tdb
, 0, "tdb_delete: WARNING tdb_unlock failed!\n"));
1463 int tdb_delete(TDB_CONTEXT
*tdb
, TDB_DATA key
)
1465 u32 hash
= tdb
->hash_fn(&key
);
1466 return tdb_delete_hash(tdb
, key
, hash
);
1469 /* store an element in the database, replacing any existing element
1472 return 0 on success, -1 on failure
1474 int tdb_store(TDB_CONTEXT
*tdb
, TDB_DATA key
, TDB_DATA dbuf
, int flag
)
1476 struct list_struct rec
;
1482 /* find which hash bucket it is in */
1483 hash
= tdb
->hash_fn(&key
);
1484 if (tdb_lock(tdb
, BUCKET(hash
), F_WRLCK
) == -1)
1487 /* check for it existing, on insert. */
1488 if (flag
== TDB_INSERT
) {
1489 if (tdb_exists_hash(tdb
, key
, hash
)) {
1490 tdb
->ecode
= TDB_ERR_EXISTS
;
1494 /* first try in-place update, on modify or replace. */
1495 if (tdb_update_hash(tdb
, key
, hash
, dbuf
) == 0)
1497 if (tdb
->ecode
== TDB_ERR_NOEXIST
&&
1498 flag
== TDB_MODIFY
) {
1499 /* if the record doesn't exist and we are in TDB_MODIFY mode then
1500 we should fail the store */
1504 /* reset the error code potentially set by the tdb_update() */
1505 tdb
->ecode
= TDB_SUCCESS
;
1507 /* delete any existing record - if it doesn't exist we don't
1508 care. Doing this first reduces fragmentation, and avoids
1509 coalescing with `allocated' block before it's updated. */
1510 if (flag
!= TDB_INSERT
)
1511 tdb_delete_hash(tdb
, key
, hash
);
1513 /* Copy key+value *before* allocating free space in case malloc
1514 fails and we are left with a dead spot in the tdb. */
1516 if (!(p
= (char *)malloc(key
.dsize
+ dbuf
.dsize
))) {
1517 tdb
->ecode
= TDB_ERR_OOM
;
1521 memcpy(p
, key
.dptr
, key
.dsize
);
1523 memcpy(p
+key
.dsize
, dbuf
.dptr
, dbuf
.dsize
);
1525 /* we have to allocate some space */
1526 if (!(rec_ptr
= tdb_allocate(tdb
, key
.dsize
+ dbuf
.dsize
, &rec
)))
1529 /* Read hash top into next ptr */
1530 if (ofs_read(tdb
, TDB_HASH_TOP(hash
), &rec
.next
) == -1)
1533 rec
.key_len
= key
.dsize
;
1534 rec
.data_len
= dbuf
.dsize
;
1535 rec
.full_hash
= hash
;
1536 rec
.magic
= TDB_MAGIC
;
1538 /* write out and point the top of the hash chain at it */
1539 if (rec_write(tdb
, rec_ptr
, &rec
) == -1
1540 || tdb_write(tdb
, rec_ptr
+sizeof(rec
), p
, key
.dsize
+dbuf
.dsize
)==-1
1541 || ofs_write(tdb
, TDB_HASH_TOP(hash
), &rec_ptr
) == -1) {
1542 /* Need to tdb_unallocate() here */
1547 tdb_unlock(tdb
, BUCKET(hash
), F_WRLCK
);
1554 /* Attempt to append data to an entry in place - this only works if the new data size
1555 is <= the old data size and the key exists.
1556 on failure return -1. Record must be locked before calling.
1558 static int tdb_append_inplace(TDB_CONTEXT
*tdb
, TDB_DATA key
, u32 hash
, TDB_DATA new_dbuf
)
1560 struct list_struct rec
;
1564 if (!(rec_ptr
= tdb_find(tdb
, key
, hash
, &rec
)))
1567 /* Append of 0 is always ok. */
1568 if (new_dbuf
.dsize
== 0)
1571 /* must be long enough for key, old data + new data and tailer */
1572 if (rec
.rec_len
< key
.dsize
+ rec
.data_len
+ new_dbuf
.dsize
+ sizeof(tdb_off
)) {
1574 tdb
->ecode
= TDB_SUCCESS
; /* Not really an error */
1578 if (tdb_write(tdb
, rec_ptr
+ sizeof(rec
) + rec
.key_len
+ rec
.data_len
,
1579 new_dbuf
.dptr
, new_dbuf
.dsize
) == -1)
1583 rec
.data_len
+= new_dbuf
.dsize
;
1584 return rec_write(tdb
, rec_ptr
, &rec
);
1587 /* Append to an entry. Create if not exist. */
1589 int tdb_append(TDB_CONTEXT
*tdb
, TDB_DATA key
, TDB_DATA new_dbuf
)
1591 struct list_struct rec
;
1596 size_t new_data_size
= 0;
1598 /* find which hash bucket it is in */
1599 hash
= tdb
->hash_fn(&key
);
1600 if (tdb_lock(tdb
, BUCKET(hash
), F_WRLCK
) == -1)
1603 /* first try in-place. */
1604 if (tdb_append_inplace(tdb
, key
, hash
, new_dbuf
) == 0)
1607 /* reset the error code potentially set by the tdb_append_inplace() */
1608 tdb
->ecode
= TDB_SUCCESS
;
1611 if (!(rec_ptr
= tdb_find(tdb
, key
, hash
, &rec
))) {
1612 if (tdb
->ecode
!= TDB_ERR_NOEXIST
)
1615 /* Not found - create. */
1617 ret
= tdb_store(tdb
, key
, new_dbuf
, TDB_INSERT
);
1621 new_data_size
= rec
.data_len
+ new_dbuf
.dsize
;
1623 /* Copy key+old_value+value *before* allocating free space in case malloc
1624 fails and we are left with a dead spot in the tdb. */
1626 if (!(p
= (char *)malloc(key
.dsize
+ new_data_size
))) {
1627 tdb
->ecode
= TDB_ERR_OOM
;
1631 /* Copy the key in place. */
1632 memcpy(p
, key
.dptr
, key
.dsize
);
1634 /* Now read the old data into place. */
1636 tdb_read(tdb
, rec_ptr
+ sizeof(rec
) + rec
.key_len
, p
+ key
.dsize
, rec
.data_len
, 0) == -1)
1639 /* Finally append the new data. */
1641 memcpy(p
+key
.dsize
+rec
.data_len
, new_dbuf
.dptr
, new_dbuf
.dsize
);
1643 /* delete any existing record - if it doesn't exist we don't
1644 care. Doing this first reduces fragmentation, and avoids
1645 coalescing with `allocated' block before it's updated. */
1647 tdb_delete_hash(tdb
, key
, hash
);
1649 if (!(rec_ptr
= tdb_allocate(tdb
, key
.dsize
+ new_data_size
, &rec
)))
1652 /* Read hash top into next ptr */
1653 if (ofs_read(tdb
, TDB_HASH_TOP(hash
), &rec
.next
) == -1)
1656 rec
.key_len
= key
.dsize
;
1657 rec
.data_len
= new_data_size
;
1658 rec
.full_hash
= hash
;
1659 rec
.magic
= TDB_MAGIC
;
1661 /* write out and point the top of the hash chain at it */
1662 if (rec_write(tdb
, rec_ptr
, &rec
) == -1
1663 || tdb_write(tdb
, rec_ptr
+sizeof(rec
), p
, key
.dsize
+new_data_size
)==-1
1664 || ofs_write(tdb
, TDB_HASH_TOP(hash
), &rec_ptr
) == -1) {
1665 /* Need to tdb_unallocate() here */
1671 tdb_unlock(tdb
, BUCKET(hash
), F_WRLCK
);
1679 static int tdb_already_open(dev_t device
,
1684 for (i
= tdbs
; i
; i
= i
->next
) {
1685 if (i
->device
== device
&& i
->inode
== ino
) {
1693 /* This is based on the hash algorithm from gdbm */
1694 static u32
default_tdb_hash(TDB_DATA
*key
)
1696 u32 value
; /* Used to compute the hash value. */
1697 u32 i
; /* Used to cycle through random values. */
1699 /* Set the initial value from the key size. */
1700 for (value
= 0x238F13AF * key
->dsize
, i
=0; i
< key
->dsize
; i
++)
1701 value
= (value
+ (key
->dptr
[i
] << (i
*5 % 24)));
1703 return (1103515243 * value
+ 12345);
1706 /* open the database, creating it if necessary
1708 The open_flags and mode are passed straight to the open call on the
1709 database file. A flags value of O_WRONLY is invalid. The hash size
1710 is advisory, use zero for a default value.
1712 Return is NULL on error, in which case errno is also set. Don't
1713 try to call tdb_error or tdb_errname, just do strerror(errno).
1715 @param name may be NULL for internal databases. */
1716 TDB_CONTEXT
*tdb_open(const char *name
, int hash_size
, int tdb_flags
,
1717 int open_flags
, mode_t mode
)
1719 return tdb_open_ex(name
, hash_size
, tdb_flags
, open_flags
, mode
, NULL
, NULL
);
1723 TDB_CONTEXT
*tdb_open_ex(const char *name
, int hash_size
, int tdb_flags
,
1724 int open_flags
, mode_t mode
,
1725 tdb_log_func log_fn
,
1726 tdb_hash_func hash_fn
)
1730 int rev
= 0, locked
= 0;
1734 if (!(tdb
= calloc(1, sizeof *tdb
))) {
1735 /* Can't log this */
1741 tdb
->map_ptr
= NULL
;
1742 tdb
->flags
= tdb_flags
;
1743 tdb
->open_flags
= open_flags
;
1744 tdb
->log_fn
= log_fn
;
1745 tdb
->hash_fn
= hash_fn
? hash_fn
: default_tdb_hash
;
1747 if ((open_flags
& O_ACCMODE
) == O_WRONLY
) {
1748 TDB_LOG((tdb
, 0, "tdb_open_ex: can't open tdb %s write-only\n",
1755 hash_size
= DEFAULT_HASH_SIZE
;
1756 if ((open_flags
& O_ACCMODE
) == O_RDONLY
) {
1758 /* read only databases don't do locking or clear if first */
1759 tdb
->flags
|= TDB_NOLOCK
;
1760 tdb
->flags
&= ~TDB_CLEAR_IF_FIRST
;
1763 /* internal databases don't mmap or lock, and start off cleared */
1764 if (tdb
->flags
& TDB_INTERNAL
) {
1765 tdb
->flags
|= (TDB_NOLOCK
| TDB_NOMMAP
);
1766 tdb
->flags
&= ~TDB_CLEAR_IF_FIRST
;
1767 if (tdb_new_database(tdb
, hash_size
) != 0) {
1768 TDB_LOG((tdb
, 0, "tdb_open_ex: tdb_new_database failed!"));
1774 if ((tdb
->fd
= open(name
, open_flags
, mode
)) == -1) {
1775 TDB_LOG((tdb
, 5, "tdb_open_ex: could not open file %s: %s\n",
1776 name
, strerror(errno
)));
1777 goto fail
; /* errno set by open(2) */
1780 /* ensure there is only one process initialising at once */
1781 if (tdb_brlock(tdb
, GLOBAL_LOCK
, F_WRLCK
, F_SETLKW
, 0) == -1) {
1782 TDB_LOG((tdb
, 0, "tdb_open_ex: failed to get global lock on %s: %s\n",
1783 name
, strerror(errno
)));
1784 goto fail
; /* errno set by tdb_brlock */
1787 /* we need to zero database if we are the only one with it open */
1788 if ((tdb_flags
& TDB_CLEAR_IF_FIRST
) &&
1789 (locked
= (tdb_brlock(tdb
, ACTIVE_LOCK
, F_WRLCK
, F_SETLK
, 0) == 0))) {
1790 open_flags
|= O_CREAT
;
1791 if (ftruncate(tdb
->fd
, 0) == -1) {
1792 TDB_LOG((tdb
, 0, "tdb_open_ex: "
1793 "failed to truncate %s: %s\n",
1794 name
, strerror(errno
)));
1795 goto fail
; /* errno set by ftruncate */
1799 if (read(tdb
->fd
, &tdb
->header
, sizeof(tdb
->header
)) != sizeof(tdb
->header
)
1800 || strcmp(tdb
->header
.magic_food
, TDB_MAGIC_FOOD
) != 0
1801 || (tdb
->header
.version
!= TDB_VERSION
1802 && !(rev
= (tdb
->header
.version
==TDB_BYTEREV(TDB_VERSION
))))) {
1803 /* its not a valid database - possibly initialise it */
1804 if (!(open_flags
& O_CREAT
) || tdb_new_database(tdb
, hash_size
) == -1) {
1805 errno
= EIO
; /* ie bad format or something */
1808 rev
= (tdb
->flags
& TDB_CONVERT
);
1810 vp
= (unsigned char *)&tdb
->header
.version
;
1811 vertest
= (((u32
)vp
[0]) << 24) | (((u32
)vp
[1]) << 16) |
1812 (((u32
)vp
[2]) << 8) | (u32
)vp
[3];
1813 tdb
->flags
|= (vertest
==TDB_VERSION
) ? TDB_BIGENDIAN
: 0;
1815 tdb
->flags
&= ~TDB_CONVERT
;
1817 tdb
->flags
|= TDB_CONVERT
;
1818 convert(&tdb
->header
, sizeof(tdb
->header
));
1820 if (fstat(tdb
->fd
, &st
) == -1)
1823 /* Is it already in the open list? If so, fail. */
1824 if (tdb_already_open(st
.st_dev
, st
.st_ino
)) {
1825 TDB_LOG((tdb
, 2, "tdb_open_ex: "
1826 "%s (%d,%d) is already open in this process\n",
1827 name
, (int)st
.st_dev
, (int)st
.st_ino
));
1832 if (!(tdb
->name
= (char *)strdup(name
))) {
1837 tdb
->map_size
= st
.st_size
;
1838 tdb
->device
= st
.st_dev
;
1839 tdb
->inode
= st
.st_ino
;
1840 tdb
->locked
= calloc(tdb
->header
.hash_size
+1, sizeof(tdb
->locked
[0]));
1842 TDB_LOG((tdb
, 2, "tdb_open_ex: "
1843 "failed to allocate lock structure for %s\n",
1850 if (!tdb
->read_only
)
1851 if (tdb_clear_spinlocks(tdb
) != 0) {
1852 TDB_LOG((tdb
, 0, "tdb_open_ex: "
1853 "failed to clear spinlock\n"));
1856 if (tdb_brlock(tdb
, ACTIVE_LOCK
, F_UNLCK
, F_SETLK
, 0) == -1) {
1857 TDB_LOG((tdb
, 0, "tdb_open_ex: "
1858 "failed to take ACTIVE_LOCK on %s: %s\n",
1859 name
, strerror(errno
)));
1865 /* We always need to do this if the CLEAR_IF_FIRST flag is set, even if
1866 we didn't get the initial exclusive lock as we need to let all other
1867 users know we're using it. */
1869 if (tdb_flags
& TDB_CLEAR_IF_FIRST
) {
1870 /* leave this lock in place to indicate it's in use */
1871 if (tdb_brlock(tdb
, ACTIVE_LOCK
, F_RDLCK
, F_SETLKW
, 0) == -1)
1877 /* Internal (memory-only) databases skip all the code above to
1878 * do with disk files, and resume here by releasing their
1879 * global lock and hooking into the active list. */
1880 if (tdb_brlock(tdb
, GLOBAL_LOCK
, F_UNLCK
, F_SETLKW
, 0) == -1)
1887 { int save_errno
= errno
;
1893 if (tdb
->flags
& TDB_INTERNAL
)
1894 SAFE_FREE(tdb
->map_ptr
);
1898 SAFE_FREE(tdb
->name
);
1900 if (close(tdb
->fd
) != 0)
1901 TDB_LOG((tdb
, 5, "tdb_open_ex: failed to close tdb->fd on error!\n"));
1902 SAFE_FREE(tdb
->locked
);
1912 * @returns -1 for error; 0 for success.
1914 int tdb_close(TDB_CONTEXT
*tdb
)
1920 if (tdb
->flags
& TDB_INTERNAL
)
1921 SAFE_FREE(tdb
->map_ptr
);
1925 SAFE_FREE(tdb
->name
);
1927 ret
= close(tdb
->fd
);
1928 SAFE_FREE(tdb
->locked
);
1930 /* Remove from contexts list */
1931 for (i
= &tdbs
; *i
; i
= &(*i
)->next
) {
1938 memset(tdb
, 0, sizeof(*tdb
));
1944 /* lock/unlock entire database */
1945 int tdb_lockall(TDB_CONTEXT
*tdb
)
1949 /* There are no locks on read-only dbs */
1951 return TDB_ERRCODE(TDB_ERR_LOCK
, -1);
1952 for (i
= 0; i
< tdb
->header
.hash_size
; i
++)
1953 if (tdb_lock(tdb
, i
, F_WRLCK
))
1956 /* If error, release locks we have... */
1957 if (i
< tdb
->header
.hash_size
) {
1960 for ( j
= 0; j
< i
; j
++)
1961 tdb_unlock(tdb
, j
, F_WRLCK
);
1962 return TDB_ERRCODE(TDB_ERR_NOLOCK
, -1);
1967 void tdb_unlockall(TDB_CONTEXT
*tdb
)
1970 for (i
=0; i
< tdb
->header
.hash_size
; i
++)
1971 tdb_unlock(tdb
, i
, F_WRLCK
);
1974 /* lock/unlock one hash chain. This is meant to be used to reduce
1975 contention - it cannot guarantee how many records will be locked */
1976 int tdb_chainlock(TDB_CONTEXT
*tdb
, TDB_DATA key
)
1978 return tdb_lock(tdb
, BUCKET(tdb
->hash_fn(&key
)), F_WRLCK
);
1981 int tdb_chainunlock(TDB_CONTEXT
*tdb
, TDB_DATA key
)
1983 return tdb_unlock(tdb
, BUCKET(tdb
->hash_fn(&key
)), F_WRLCK
);
1986 int tdb_chainlock_read(TDB_CONTEXT
*tdb
, TDB_DATA key
)
1988 return tdb_lock(tdb
, BUCKET(tdb
->hash_fn(&key
)), F_RDLCK
);
1991 int tdb_chainunlock_read(TDB_CONTEXT
*tdb
, TDB_DATA key
)
1993 return tdb_unlock(tdb
, BUCKET(tdb
->hash_fn(&key
)), F_RDLCK
);
1997 /* register a loging function */
1998 void tdb_logging_function(TDB_CONTEXT
*tdb
, void (*fn
)(TDB_CONTEXT
*, int , const char *, ...))
2003 /* reopen a tdb - this can be used after a fork to ensure that we have an independent
2004 seek pointer from our parent and to re-establish locks */
2005 int tdb_reopen(TDB_CONTEXT
*tdb
)
2009 if (tdb
->flags
& TDB_INTERNAL
)
2010 return 0; /* Nothing to do. */
2011 if (tdb_munmap(tdb
) != 0) {
2012 TDB_LOG((tdb
, 0, "tdb_reopen: munmap failed (%s)\n", strerror(errno
)));
2015 if (close(tdb
->fd
) != 0)
2016 TDB_LOG((tdb
, 0, "tdb_reopen: WARNING closing tdb->fd failed!\n"));
2017 tdb
->fd
= open(tdb
->name
, tdb
->open_flags
& ~(O_CREAT
|O_TRUNC
), 0);
2018 if (tdb
->fd
== -1) {
2019 TDB_LOG((tdb
, 0, "tdb_reopen: open failed (%s)\n", strerror(errno
)));
2022 if (fstat(tdb
->fd
, &st
) != 0) {
2023 TDB_LOG((tdb
, 0, "tdb_reopen: fstat failed (%s)\n", strerror(errno
)));
2026 if (st
.st_ino
!= tdb
->inode
|| st
.st_dev
!= tdb
->device
) {
2027 TDB_LOG((tdb
, 0, "tdb_reopen: file dev/inode has changed!\n"));
2031 if ((tdb
->flags
& TDB_CLEAR_IF_FIRST
) && (tdb_brlock(tdb
, ACTIVE_LOCK
, F_RDLCK
, F_SETLKW
, 0) == -1)) {
2032 TDB_LOG((tdb
, 0, "tdb_reopen: failed to obtain active lock\n"));
2043 /* reopen all tdb's */
2044 int tdb_reopen_all(void)
2048 for (tdb
=tdbs
; tdb
; tdb
= tdb
->next
) {
2049 /* Ensure no clear-if-first. */
2050 tdb
->flags
&= ~TDB_CLEAR_IF_FIRST
;
2051 if (tdb_reopen(tdb
) != 0)