2 Unix SMB/CIFS implementation.
3 Samba database functions
4 Copyright (C) Andrew Tridgell 1999-2000
5 Copyright (C) Luke Kenneth Casson Leighton 2000
6 Copyright (C) Paul `Rusty' Russell 2000
7 Copyright (C) Jeremy Allison 2000-2003
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26 /* NOTE: If you use tdbs under valgrind, and in particular if you run
27 * tdbtorture, you may get spurious "uninitialized value" warnings. I
28 * think this is because valgrind doesn't understand that the mmap'd
29 * area may be written to by other processes. Memory can, from the
30 * point of view of the grinded process, spontaneously become
33 * I can think of a few solutions. [mbp 20030311]
35 * 1 - Write suppressions for Valgrind so that it doesn't complain
36 * about this. Probably the most reasonable but people need to
37 * remember to use them.
39 * 2 - Use IO not mmap when running under valgrind. Not so nice.
41 * 3 - Use the special valgrind macros to mark memory as valid at the
42 * right time. Probably too hard -- the process just doesn't know.
50 #define _XOPEN_SOURCE 600
67 #define TDB_MAGIC_FOOD "TDB file\n"
68 #define TDB_VERSION (0x26011967 + 6)
69 #define TDB_MAGIC (0x26011999U)
70 #define TDB_FREE_MAGIC (~TDB_MAGIC)
71 #define TDB_DEAD_MAGIC (0xFEE1DEAD)
72 #define TDB_ALIGNMENT 4
73 #define MIN_REC_SIZE (2*sizeof(struct list_struct) + TDB_ALIGNMENT)
74 #define DEFAULT_HASH_SIZE 131
75 #define TDB_PAGE_SIZE 0x2000
76 #define FREELIST_TOP (sizeof(struct tdb_header))
77 #define TDB_ALIGN(x,a) (((x) + (a)-1) & ~((a)-1))
78 #define TDB_BYTEREV(x) (((((x)&0xff)<<24)|((x)&0xFF00)<<8)|(((x)>>8)&0xFF00)|((x)>>24))
79 #define TDB_DEAD(r) ((r)->magic == TDB_DEAD_MAGIC)
80 #define TDB_BAD_MAGIC(r) ((r)->magic != TDB_MAGIC && !TDB_DEAD(r))
81 #define TDB_HASH_TOP(hash) (FREELIST_TOP + (BUCKET(hash)+1)*sizeof(tdb_off))
83 /* NB assumes there is a local variable called "tdb" that is the
84 * current context, also takes doubly-parenthesized print-style
86 #define TDB_LOG(x) (tdb->log_fn?((tdb->log_fn x),0) : 0)
97 #define MAP_FAILED ((void *)-1)
100 /* free memory if the pointer is valid and zero the pointer */
102 #define SAFE_FREE(x) do { if ((x) != NULL) {free((x)); (x)=NULL;} } while(0)
105 #define BUCKET(hash) ((hash) % tdb->header.hash_size)
108 /* all contexts, to ensure no double-opens (fcntl locks don't nest!) */
109 static TDB_CONTEXT *tdbs = NULL;
111 static int tdb_munmap(TDB_CONTEXT *tdb)
113 if (tdb->flags & TDB_INTERNAL)
118 int ret = munmap(tdb->map_ptr, tdb->map_size);
127 static void tdb_mmap(TDB_CONTEXT *tdb)
129 if (tdb->flags & TDB_INTERNAL)
133 if (!(tdb->flags & TDB_NOMMAP)) {
134 tdb->map_ptr = mmap(NULL, tdb->map_size,
135 PROT_READ|(tdb->read_only? 0:PROT_WRITE),
136 MAP_SHARED|MAP_FILE, tdb->fd, 0);
139 * NB. When mmap fails it returns MAP_FAILED *NOT* NULL !!!!
142 if (tdb->map_ptr == MAP_FAILED) {
144 TDB_LOG((tdb, 2, "tdb_mmap failed for size %d (%s)\n",
145 tdb->map_size, strerror(errno)));
155 /* Endian conversion: we only ever deal with 4 byte quantities */
156 static void *convert(void *buf, u32 size)
159 for (i = 0; i < size / 4; i++)
160 p[i] = TDB_BYTEREV(p[i]);
163 #define DOCONV() (tdb->flags & TDB_CONVERT)
164 #define CONVERT(x) (DOCONV() ? convert(&x, sizeof(x)) : &x)
166 /* the body of the database is made of one list_struct for the free space
167 plus a separate data list for each hash value */
169 tdb_off next; /* offset of the next record in the list */
170 tdb_len rec_len; /* total byte length of record */
171 tdb_len key_len; /* byte length of key */
172 tdb_len data_len; /* byte length of data */
173 u32 full_hash; /* the full 32 bit hash of the key */
174 u32 magic; /* try to catch errors */
175 /* the following union is implied:
177 char record[rec_len];
182 u32 totalsize; (tailer)
187 /***************************************************************
188 Allow a caller to set a "alarm" flag that tdb can check to abort
189 a blocking lock on SIGALRM.
190 ***************************************************************/
192 static sig_atomic_t *palarm_fired;
194 void tdb_set_lock_alarm(sig_atomic_t *palarm)
196 palarm_fired = palarm;
199 /* a byte range locking function - return 0 on success
200 this functions locks/unlocks 1 byte at the specified offset.
202 On error, errno is also set so that errors are passed back properly
203 through tdb_open(). */
204 static int tdb_brlock(TDB_CONTEXT *tdb, tdb_off offset,
205 int rw_type, int lck_type, int probe)
210 if (tdb->flags & TDB_NOLOCK)
212 if ((rw_type == F_WRLCK) && (tdb->read_only)) {
218 fl.l_whence = SEEK_SET;
224 ret = fcntl(tdb->fd,lck_type,&fl);
225 if (ret == -1 && errno == EINTR && palarm_fired && *palarm_fired)
227 } while (ret == -1 && errno == EINTR);
230 if (!probe && lck_type != F_SETLK) {
231 /* Ensure error code is set for log fun to examine. */
232 if (errno == EINTR && palarm_fired && *palarm_fired)
233 tdb->ecode = TDB_ERR_LOCK_TIMEOUT;
235 tdb->ecode = TDB_ERR_LOCK;
236 TDB_LOG((tdb, 5,"tdb_brlock failed (fd=%d) at offset %d rw_type=%d lck_type=%d\n",
237 tdb->fd, offset, rw_type, lck_type));
239 /* Was it an alarm timeout ? */
240 if (errno == EINTR && palarm_fired && *palarm_fired)
241 return TDB_ERRCODE(TDB_ERR_LOCK_TIMEOUT, -1);
242 /* Otherwise - generic lock error. */
243 /* errno set by fcntl */
244 return TDB_ERRCODE(TDB_ERR_LOCK, -1);
249 /* lock a list in the database. list -1 is the alloc list */
250 static int tdb_lock(TDB_CONTEXT *tdb, int list, int ltype)
252 if (list < -1 || list >= (int)tdb->header.hash_size) {
253 TDB_LOG((tdb, 0,"tdb_lock: invalid list %d for ltype=%d\n",
257 if (tdb->flags & TDB_NOLOCK)
260 /* Since fcntl locks don't nest, we do a lock for the first one,
261 and simply bump the count for future ones */
262 if (tdb->locked[list+1].count == 0) {
263 if (!tdb->read_only && tdb->header.rwlocks) {
264 if (tdb_spinlock(tdb, list, ltype)) {
265 TDB_LOG((tdb, 0, "tdb_lock spinlock failed on list ltype=%d\n",
269 } else if (tdb_brlock(tdb,FREELIST_TOP+4*list,ltype,F_SETLKW, 0)) {
270 TDB_LOG((tdb, 0,"tdb_lock failed on list %d ltype=%d (%s)\n",
271 list, ltype, strerror(errno)));
274 tdb->locked[list+1].ltype = ltype;
276 tdb->locked[list+1].count++;
280 /* unlock the database: returns void because it's too late for errors. */
281 /* changed to return int it may be interesting to know there
282 has been an error --simo */
283 static int tdb_unlock(TDB_CONTEXT *tdb, int list, int ltype)
287 if (tdb->flags & TDB_NOLOCK)
291 if (list < -1 || list >= (int)tdb->header.hash_size) {
292 TDB_LOG((tdb, 0, "tdb_unlock: list %d invalid (%d)\n", list, tdb->header.hash_size));
296 if (tdb->locked[list+1].count==0) {
297 TDB_LOG((tdb, 0, "tdb_unlock: count is 0\n"));
301 if (tdb->locked[list+1].count == 1) {
302 /* Down to last nested lock: unlock underneath */
303 if (!tdb->read_only && tdb->header.rwlocks) {
304 ret = tdb_spinunlock(tdb, list, ltype);
306 ret = tdb_brlock(tdb, FREELIST_TOP+4*list, F_UNLCK, F_SETLKW, 0);
311 tdb->locked[list+1].count--;
314 TDB_LOG((tdb, 0,"tdb_unlock: An error occurred unlocking!\n"));
318 /* This is based on the hash algorithm from gdbm */
319 static u32 tdb_hash(TDB_DATA *key)
321 u32 value; /* Used to compute the hash value. */
322 u32 i; /* Used to cycle through random values. */
324 /* Set the initial value from the key size. */
325 for (value = 0x238F13AF * key->dsize, i=0; i < key->dsize; i++)
326 value = (value + (key->dptr[i] << (i*5 % 24)));
328 return (1103515243 * value + 12345);
331 /* check for an out of bounds access - if it is out of bounds then
332 see if the database has been expanded by someone else and expand
334 note that "len" is the minimum length needed for the db
336 static int tdb_oob(TDB_CONTEXT *tdb, tdb_off len, int probe)
339 if (len <= tdb->map_size)
341 if (tdb->flags & TDB_INTERNAL) {
343 /* Ensure ecode is set for log fn. */
344 tdb->ecode = TDB_ERR_IO;
345 TDB_LOG((tdb, 0,"tdb_oob len %d beyond internal malloc size %d\n",
346 (int)len, (int)tdb->map_size));
348 return TDB_ERRCODE(TDB_ERR_IO, -1);
351 if (fstat(tdb->fd, &st) == -1)
352 return TDB_ERRCODE(TDB_ERR_IO, -1);
354 if (st.st_size < (size_t)len) {
356 /* Ensure ecode is set for log fn. */
357 tdb->ecode = TDB_ERR_IO;
358 TDB_LOG((tdb, 0,"tdb_oob len %d beyond eof at %d\n",
359 (int)len, (int)st.st_size));
361 return TDB_ERRCODE(TDB_ERR_IO, -1);
364 /* Unmap, update size, remap */
365 if (tdb_munmap(tdb) == -1)
366 return TDB_ERRCODE(TDB_ERR_IO, -1);
367 tdb->map_size = st.st_size;
372 /* write a lump of data at a specified offset */
373 static int tdb_write(TDB_CONTEXT *tdb, tdb_off off, void *buf, tdb_len len)
375 if (tdb_oob(tdb, off + len, 0) != 0)
379 memcpy(off + (char *)tdb->map_ptr, buf, len);
381 else if (pwrite(tdb->fd, buf, len, off) != (ssize_t)len) {
383 else if (lseek(tdb->fd, off, SEEK_SET) != off
384 || write(tdb->fd, buf, len) != (ssize_t)len) {
386 /* Ensure ecode is set for log fn. */
387 tdb->ecode = TDB_ERR_IO;
388 TDB_LOG((tdb, 0,"tdb_write failed at %d len=%d (%s)\n",
389 off, len, strerror(errno)));
390 return TDB_ERRCODE(TDB_ERR_IO, -1);
395 /* read a lump of data at a specified offset, maybe convert */
396 static int tdb_read(TDB_CONTEXT *tdb,tdb_off off,void *buf,tdb_len len,int cv)
398 if (tdb_oob(tdb, off + len, 0) != 0)
402 memcpy(buf, off + (char *)tdb->map_ptr, len);
404 else if (pread(tdb->fd, buf, len, off) != (ssize_t)len) {
406 else if (lseek(tdb->fd, off, SEEK_SET) != off
407 || read(tdb->fd, buf, len) != (ssize_t)len) {
409 /* Ensure ecode is set for log fn. */
410 tdb->ecode = TDB_ERR_IO;
411 TDB_LOG((tdb, 0,"tdb_read failed at %d len=%d (%s)\n",
412 off, len, strerror(errno)));
413 return TDB_ERRCODE(TDB_ERR_IO, -1);
420 /* read a lump of data, allocating the space for it */
421 static char *tdb_alloc_read(TDB_CONTEXT *tdb, tdb_off offset, tdb_len len)
425 if (!(buf = malloc(len))) {
426 /* Ensure ecode is set for log fn. */
427 tdb->ecode = TDB_ERR_OOM;
428 TDB_LOG((tdb, 0,"tdb_alloc_read malloc failed len=%d (%s)\n",
429 len, strerror(errno)));
430 return TDB_ERRCODE(TDB_ERR_OOM, buf);
432 if (tdb_read(tdb, offset, buf, len, 0) == -1) {
439 /* read/write a tdb_off */
440 static int ofs_read(TDB_CONTEXT *tdb, tdb_off offset, tdb_off *d)
442 return tdb_read(tdb, offset, (char*)d, sizeof(*d), DOCONV());
444 static int ofs_write(TDB_CONTEXT *tdb, tdb_off offset, tdb_off *d)
447 return tdb_write(tdb, offset, CONVERT(off), sizeof(*d));
450 /* read/write a record */
451 static int rec_read(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec)
453 if (tdb_read(tdb, offset, rec, sizeof(*rec),DOCONV()) == -1)
455 if (TDB_BAD_MAGIC(rec)) {
456 /* Ensure ecode is set for log fn. */
457 tdb->ecode = TDB_ERR_CORRUPT;
458 TDB_LOG((tdb, 0,"rec_read bad magic 0x%x at offset=%d\n", rec->magic, offset));
459 return TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
461 return tdb_oob(tdb, rec->next+sizeof(*rec), 0);
463 static int rec_write(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec)
465 struct list_struct r = *rec;
466 return tdb_write(tdb, offset, CONVERT(r), sizeof(r));
469 /* read a freelist record and check for simple errors */
470 static int rec_free_read(TDB_CONTEXT *tdb, tdb_off off, struct list_struct *rec)
472 if (tdb_read(tdb, off, rec, sizeof(*rec),DOCONV()) == -1)
475 if (rec->magic == TDB_MAGIC) {
476 /* this happens when a app is showdown while deleting a record - we should
477 not completely fail when this happens */
478 TDB_LOG((tdb, 0,"rec_free_read non-free magic at offset=%d - fixing\n",
480 rec->magic = TDB_FREE_MAGIC;
481 if (tdb_write(tdb, off, rec, sizeof(*rec)) == -1)
485 if (rec->magic != TDB_FREE_MAGIC) {
486 /* Ensure ecode is set for log fn. */
487 tdb->ecode = TDB_ERR_CORRUPT;
488 TDB_LOG((tdb, 0,"rec_free_read bad magic 0x%x at offset=%d\n",
490 return TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
492 if (tdb_oob(tdb, rec->next+sizeof(*rec), 0) != 0)
497 /* update a record tailer (must hold allocation lock) */
498 static int update_tailer(TDB_CONTEXT *tdb, tdb_off offset,
499 const struct list_struct *rec)
503 /* Offset of tailer from record header */
504 totalsize = sizeof(*rec) + rec->rec_len;
505 return ofs_write(tdb, offset + totalsize - sizeof(tdb_off),
509 static tdb_off tdb_dump_record(TDB_CONTEXT *tdb, tdb_off offset)
511 struct list_struct rec;
512 tdb_off tailer_ofs, tailer;
514 if (tdb_read(tdb, offset, (char *)&rec, sizeof(rec), DOCONV()) == -1) {
515 printf("ERROR: failed to read record at %u\n", offset);
519 printf(" rec: offset=%u next=%d rec_len=%d key_len=%d data_len=%d full_hash=0x%x magic=0x%x\n",
520 offset, rec.next, rec.rec_len, rec.key_len, rec.data_len, rec.full_hash, rec.magic);
522 tailer_ofs = offset + sizeof(rec) + rec.rec_len - sizeof(tdb_off);
523 if (ofs_read(tdb, tailer_ofs, &tailer) == -1) {
524 printf("ERROR: failed to read tailer at %u\n", tailer_ofs);
528 if (tailer != rec.rec_len + sizeof(rec)) {
529 printf("ERROR: tailer does not match record! tailer=%u totalsize=%u\n",
530 (unsigned)tailer, (unsigned)(rec.rec_len + sizeof(rec)));
535 static int tdb_dump_chain(TDB_CONTEXT *tdb, int i)
537 tdb_off rec_ptr, top;
539 top = TDB_HASH_TOP(i);
541 if (tdb_lock(tdb, i, F_WRLCK) != 0)
544 if (ofs_read(tdb, top, &rec_ptr) == -1)
545 return tdb_unlock(tdb, i, F_WRLCK);
548 printf("hash=%d\n", i);
551 rec_ptr = tdb_dump_record(tdb, rec_ptr);
554 return tdb_unlock(tdb, i, F_WRLCK);
557 void tdb_dump_all(TDB_CONTEXT *tdb)
560 for (i=0;i<tdb->header.hash_size;i++) {
561 tdb_dump_chain(tdb, i);
563 printf("freelist:\n");
564 tdb_dump_chain(tdb, -1);
567 int tdb_printfreelist(TDB_CONTEXT *tdb)
571 tdb_off offset, rec_ptr;
572 struct list_struct rec;
574 if ((ret = tdb_lock(tdb, -1, F_WRLCK)) != 0)
577 offset = FREELIST_TOP;
579 /* read in the freelist top */
580 if (ofs_read(tdb, offset, &rec_ptr) == -1) {
581 tdb_unlock(tdb, -1, F_WRLCK);
585 printf("freelist top=[0x%08x]\n", rec_ptr );
587 if (tdb_read(tdb, rec_ptr, (char *)&rec, sizeof(rec), DOCONV()) == -1) {
588 tdb_unlock(tdb, -1, F_WRLCK);
592 if (rec.magic != TDB_FREE_MAGIC) {
593 printf("bad magic 0x%08x in free list\n", rec.magic);
594 tdb_unlock(tdb, -1, F_WRLCK);
598 printf("entry offset=[0x%08x], rec.rec_len = [0x%08x (%d)]\n", rec.next, rec.rec_len, rec.rec_len );
599 total_free += rec.rec_len;
601 /* move to the next record */
604 printf("total rec_len = [0x%08x (%d)]\n", (int)total_free,
607 return tdb_unlock(tdb, -1, F_WRLCK);
610 /* Remove an element from the freelist. Must have alloc lock. */
611 static int remove_from_freelist(TDB_CONTEXT *tdb, tdb_off off, tdb_off next)
615 /* read in the freelist top */
616 last_ptr = FREELIST_TOP;
617 while (ofs_read(tdb, last_ptr, &i) != -1 && i != 0) {
619 /* We've found it! */
620 return ofs_write(tdb, last_ptr, &next);
622 /* Follow chain (next offset is at start of record) */
625 TDB_LOG((tdb, 0,"remove_from_freelist: not on list at off=%d\n", off));
626 return TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
629 /* Add an element into the freelist. Merge adjacent records if
631 static int tdb_free(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec)
635 /* Allocation and tailer lock */
636 if (tdb_lock(tdb, -1, F_WRLCK) != 0)
639 /* set an initial tailer, so if we fail we don't leave a bogus record */
640 if (update_tailer(tdb, offset, rec) != 0) {
641 TDB_LOG((tdb, 0, "tdb_free: upfate_tailer failed!\n"));
645 /* Look right first (I'm an Australian, dammit) */
646 right = offset + sizeof(*rec) + rec->rec_len;
647 if (right + sizeof(*rec) <= tdb->map_size) {
648 struct list_struct r;
650 if (tdb_read(tdb, right, &r, sizeof(r), DOCONV()) == -1) {
651 TDB_LOG((tdb, 0, "tdb_free: right read failed at %u\n", right));
655 /* If it's free, expand to include it. */
656 if (r.magic == TDB_FREE_MAGIC) {
657 if (remove_from_freelist(tdb, right, r.next) == -1) {
658 TDB_LOG((tdb, 0, "tdb_free: right free failed at %u\n", right));
661 rec->rec_len += sizeof(r) + r.rec_len;
667 left = offset - sizeof(tdb_off);
668 if (left > TDB_HASH_TOP(tdb->header.hash_size-1)) {
669 struct list_struct l;
672 /* Read in tailer and jump back to header */
673 if (ofs_read(tdb, left, &leftsize) == -1) {
674 TDB_LOG((tdb, 0, "tdb_free: left offset read failed at %u\n", left));
677 left = offset - leftsize;
679 /* Now read in record */
680 if (tdb_read(tdb, left, &l, sizeof(l), DOCONV()) == -1) {
681 TDB_LOG((tdb, 0, "tdb_free: left read failed at %u (%u)\n", left, leftsize));
685 /* If it's free, expand to include it. */
686 if (l.magic == TDB_FREE_MAGIC) {
687 if (remove_from_freelist(tdb, left, l.next) == -1) {
688 TDB_LOG((tdb, 0, "tdb_free: left free failed at %u\n", left));
692 rec->rec_len += leftsize;
698 if (update_tailer(tdb, offset, rec) == -1) {
699 TDB_LOG((tdb, 0, "tdb_free: update_tailer failed at %u\n", offset));
703 /* Now, prepend to free list */
704 rec->magic = TDB_FREE_MAGIC;
706 if (ofs_read(tdb, FREELIST_TOP, &rec->next) == -1 ||
707 rec_write(tdb, offset, rec) == -1 ||
708 ofs_write(tdb, FREELIST_TOP, &offset) == -1) {
709 TDB_LOG((tdb, 0, "tdb_free record write failed at offset=%d\n", offset));
713 /* And we're done. */
714 tdb_unlock(tdb, -1, F_WRLCK);
718 tdb_unlock(tdb, -1, F_WRLCK);
723 /* expand a file. we prefer to use ftruncate, as that is what posix
724 says to use for mmap expansion */
725 static int expand_file(TDB_CONTEXT *tdb, tdb_off size, tdb_off addition)
728 #if HAVE_FTRUNCATE_EXTEND
729 if (ftruncate(tdb->fd, size+addition) != 0) {
730 TDB_LOG((tdb, 0, "expand_file ftruncate to %d failed (%s)\n",
731 size+addition, strerror(errno)));
738 if (pwrite(tdb->fd, &b, 1, (size+addition) - 1) != 1) {
740 if (lseek(tdb->fd, (size+addition) - 1, SEEK_SET) != (size+addition) - 1 ||
741 write(tdb->fd, &b, 1) != 1) {
743 TDB_LOG((tdb, 0, "expand_file to %d failed (%s)\n",
744 size+addition, strerror(errno)));
749 /* now fill the file with something. This ensures that the file isn't sparse, which would be
750 very bad if we ran out of disk. This must be done with write, not via mmap */
751 memset(buf, 0x42, sizeof(buf));
753 int n = addition>sizeof(buf)?sizeof(buf):addition;
755 int ret = pwrite(tdb->fd, buf, n, size);
758 if (lseek(tdb->fd, size, SEEK_SET) != size)
760 ret = write(tdb->fd, buf, n);
763 TDB_LOG((tdb, 0, "expand_file write of %d failed (%s)\n",
764 n, strerror(errno)));
774 /* expand the database at least size bytes by expanding the underlying
775 file and doing the mmap again if necessary */
776 static int tdb_expand(TDB_CONTEXT *tdb, tdb_off size)
778 struct list_struct rec;
781 if (tdb_lock(tdb, -1, F_WRLCK) == -1) {
782 TDB_LOG((tdb, 0, "lock failed in tdb_expand\n"));
786 /* must know about any previous expansions by another process */
787 tdb_oob(tdb, tdb->map_size + 1, 1);
789 /* always make room for at least 10 more records, and round
790 the database up to a multiple of TDB_PAGE_SIZE */
791 size = TDB_ALIGN(tdb->map_size + size*10, TDB_PAGE_SIZE) - tdb->map_size;
793 if (!(tdb->flags & TDB_INTERNAL))
797 * We must ensure the file is unmapped before doing this
798 * to ensure consistency with systems like OpenBSD where
799 * writes and mmaps are not consistent.
802 /* expand the file itself */
803 if (!(tdb->flags & TDB_INTERNAL)) {
804 if (expand_file(tdb, tdb->map_size, size) != 0)
808 tdb->map_size += size;
810 if (tdb->flags & TDB_INTERNAL)
811 tdb->map_ptr = realloc(tdb->map_ptr, tdb->map_size);
814 * We must ensure the file is remapped before adding the space
815 * to ensure consistency with systems like OpenBSD where
816 * writes and mmaps are not consistent.
819 /* We're ok if the mmap fails as we'll fallback to read/write */
823 /* form a new freelist record */
824 memset(&rec,'\0',sizeof(rec));
825 rec.rec_len = size - sizeof(rec);
827 /* link it into the free list */
828 offset = tdb->map_size - size;
829 if (tdb_free(tdb, offset, &rec) == -1)
832 tdb_unlock(tdb, -1, F_WRLCK);
835 tdb_unlock(tdb, -1, F_WRLCK);
839 /* allocate some space from the free list. The offset returned points
840 to a unconnected list_struct within the database with room for at
841 least length bytes of total data
843 0 is returned if the space could not be allocated
845 static tdb_off tdb_allocate(TDB_CONTEXT *tdb, tdb_len length,
846 struct list_struct *rec)
848 tdb_off rec_ptr, last_ptr, newrec_ptr;
849 struct list_struct newrec;
851 if (tdb_lock(tdb, -1, F_WRLCK) == -1)
854 /* Extra bytes required for tailer */
855 length += sizeof(tdb_off);
858 last_ptr = FREELIST_TOP;
860 /* read in the freelist top */
861 if (ofs_read(tdb, FREELIST_TOP, &rec_ptr) == -1)
864 /* keep looking until we find a freelist record big enough */
866 if (rec_free_read(tdb, rec_ptr, rec) == -1)
869 if (rec->rec_len >= length) {
870 /* found it - now possibly split it up */
871 if (rec->rec_len > length + MIN_REC_SIZE) {
872 /* Length of left piece */
873 length = TDB_ALIGN(length, TDB_ALIGNMENT);
875 /* Right piece to go on free list */
876 newrec.rec_len = rec->rec_len
877 - (sizeof(*rec) + length);
878 newrec_ptr = rec_ptr + sizeof(*rec) + length;
880 /* And left record is shortened */
881 rec->rec_len = length;
885 /* Remove allocated record from the free list */
886 if (ofs_write(tdb, last_ptr, &rec->next) == -1)
889 /* Update header: do this before we drop alloc
890 lock, otherwise tdb_free() might try to
891 merge with us, thinking we're free.
892 (Thanks Jeremy Allison). */
893 rec->magic = TDB_MAGIC;
894 if (rec_write(tdb, rec_ptr, rec) == -1)
897 /* Did we create new block? */
899 /* Update allocated record tailer (we
901 if (update_tailer(tdb, rec_ptr, rec) == -1)
904 /* Free new record */
905 if (tdb_free(tdb, newrec_ptr, &newrec) == -1)
909 /* all done - return the new record offset */
910 tdb_unlock(tdb, -1, F_WRLCK);
913 /* move to the next record */
917 /* we didn't find enough space. See if we can expand the
918 database and if we can then try again */
919 if (tdb_expand(tdb, length + sizeof(*rec)) == 0)
922 tdb_unlock(tdb, -1, F_WRLCK);
926 /* initialise a new database with a specified hash size */
927 static int tdb_new_database(TDB_CONTEXT *tdb, int hash_size)
929 struct tdb_header *newdb;
932 /* We make it up in memory, then write it out if not internal */
933 size = sizeof(struct tdb_header) + (hash_size+1)*sizeof(tdb_off);
934 if (!(newdb = calloc(size, 1)))
935 return TDB_ERRCODE(TDB_ERR_OOM, -1);
937 /* Fill in the header */
938 newdb->version = TDB_VERSION;
939 newdb->hash_size = hash_size;
941 newdb->rwlocks = size;
943 if (tdb->flags & TDB_INTERNAL) {
944 tdb->map_size = size;
945 tdb->map_ptr = (char *)newdb;
946 memcpy(&tdb->header, newdb, sizeof(tdb->header));
947 /* Convert the `ondisk' version if asked. */
951 if (lseek(tdb->fd, 0, SEEK_SET) == -1)
954 if (ftruncate(tdb->fd, 0) == -1)
957 /* This creates an endian-converted header, as if read from disk */
959 memcpy(&tdb->header, newdb, sizeof(tdb->header));
960 /* Don't endian-convert the magic food! */
961 memcpy(newdb->magic_food, TDB_MAGIC_FOOD, strlen(TDB_MAGIC_FOOD)+1);
962 if (write(tdb->fd, newdb, size) != size)
965 ret = tdb_create_rwlocks(tdb->fd, hash_size);
972 /* Returns 0 on fail. On success, return offset of record, and fills
974 static tdb_off tdb_find(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash,
975 struct list_struct *r)
979 /* read in the hash top */
980 if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1)
983 /* keep looking until we find the right record */
985 if (rec_read(tdb, rec_ptr, r) == -1)
988 if (!TDB_DEAD(r) && hash==r->full_hash && key.dsize==r->key_len) {
990 /* a very likely hit - read the key */
991 k = tdb_alloc_read(tdb, rec_ptr + sizeof(*r),
996 if (memcmp(key.dptr, k, key.dsize) == 0) {
1004 return TDB_ERRCODE(TDB_ERR_NOEXIST, 0);
1007 /* If they do lockkeys, check that this hash is one they locked */
1008 static int tdb_keylocked(TDB_CONTEXT *tdb, u32 hash)
1011 if (!tdb->lockedkeys)
1013 for (i = 0; i < tdb->lockedkeys[0]; i++)
1014 if (tdb->lockedkeys[i+1] == hash)
1016 return TDB_ERRCODE(TDB_ERR_NOLOCK, 0);
1019 /* As tdb_find, but if you succeed, keep the lock */
1020 static tdb_off tdb_find_lock(TDB_CONTEXT *tdb, TDB_DATA key, int locktype,
1021 struct list_struct *rec)
1025 hash = tdb_hash(&key);
1026 if (!tdb_keylocked(tdb, hash))
1028 if (tdb_lock(tdb, BUCKET(hash), locktype) == -1)
1030 if (!(rec_ptr = tdb_find(tdb, key, hash, rec)))
1031 tdb_unlock(tdb, BUCKET(hash), locktype);
1035 enum TDB_ERROR tdb_error(TDB_CONTEXT *tdb)
1040 static struct tdb_errname {
1041 enum TDB_ERROR ecode; const char *estring;
1042 } emap[] = { {TDB_SUCCESS, "Success"},
1043 {TDB_ERR_CORRUPT, "Corrupt database"},
1044 {TDB_ERR_IO, "IO Error"},
1045 {TDB_ERR_LOCK, "Locking error"},
1046 {TDB_ERR_OOM, "Out of memory"},
1047 {TDB_ERR_EXISTS, "Record exists"},
1048 {TDB_ERR_NOLOCK, "Lock exists on other keys"},
1049 {TDB_ERR_NOEXIST, "Record does not exist"} };
1051 /* Error string for the last tdb error */
1052 const char *tdb_errorstr(TDB_CONTEXT *tdb)
1055 for (i = 0; i < sizeof(emap) / sizeof(struct tdb_errname); i++)
1056 if (tdb->ecode == emap[i].ecode)
1057 return emap[i].estring;
1058 return "Invalid error code";
1061 /* update an entry in place - this only works if the new data size
1062 is <= the old data size and the key exists.
1063 on failure return -1.
1066 static int tdb_update(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf)
1068 struct list_struct rec;
1072 if (!(rec_ptr = tdb_find(tdb, key, tdb_hash(&key), &rec)))
1075 /* must be long enough key, data and tailer */
1076 if (rec.rec_len < key.dsize + dbuf.dsize + sizeof(tdb_off)) {
1077 tdb->ecode = TDB_SUCCESS; /* Not really an error */
1081 if (tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len,
1082 dbuf.dptr, dbuf.dsize) == -1)
1085 if (dbuf.dsize != rec.data_len) {
1087 rec.data_len = dbuf.dsize;
1088 return rec_write(tdb, rec_ptr, &rec);
1094 /* find an entry in the database given a key */
1095 /* If an entry doesn't exist tdb_err will be set to
1096 * TDB_ERR_NOEXIST. If a key has no data attached
1097 * tdb_err will not be set. Both will return a
1098 * zero pptr and zero dsize.
1101 TDB_DATA tdb_fetch(TDB_CONTEXT *tdb, TDB_DATA key)
1104 struct list_struct rec;
1107 /* find which hash bucket it is in */
1108 if (!(rec_ptr = tdb_find_lock(tdb,key,F_RDLCK,&rec)))
1112 ret.dptr = tdb_alloc_read(tdb, rec_ptr + sizeof(rec) + rec.key_len,
1116 ret.dsize = rec.data_len;
1117 tdb_unlock(tdb, BUCKET(rec.full_hash), F_RDLCK);
1121 /* check if an entry in the database exists
1123 note that 1 is returned if the key is found and 0 is returned if not found
1124 this doesn't match the conventions in the rest of this module, but is
1125 compatible with gdbm
1127 int tdb_exists(TDB_CONTEXT *tdb, TDB_DATA key)
1129 struct list_struct rec;
1131 if (tdb_find_lock(tdb, key, F_RDLCK, &rec) == 0)
1133 tdb_unlock(tdb, BUCKET(rec.full_hash), F_RDLCK);
1137 /* record lock stops delete underneath */
1138 static int lock_record(TDB_CONTEXT *tdb, tdb_off off)
1140 return off ? tdb_brlock(tdb, off, F_RDLCK, F_SETLKW, 0) : 0;
1143 Write locks override our own fcntl readlocks, so check it here.
1144 Note this is meant to be F_SETLK, *not* F_SETLKW, as it's not
1145 an error to fail to get the lock here.
1148 static int write_lock_record(TDB_CONTEXT *tdb, tdb_off off)
1150 struct tdb_traverse_lock *i;
1151 for (i = &tdb->travlocks; i; i = i->next)
1154 return tdb_brlock(tdb, off, F_WRLCK, F_SETLK, 1);
1158 Note this is meant to be F_SETLK, *not* F_SETLKW, as it's not
1159 an error to fail to get the lock here.
1162 static int write_unlock_record(TDB_CONTEXT *tdb, tdb_off off)
1164 return tdb_brlock(tdb, off, F_UNLCK, F_SETLK, 0);
1166 /* fcntl locks don't stack: avoid unlocking someone else's */
1167 static int unlock_record(TDB_CONTEXT *tdb, tdb_off off)
1169 struct tdb_traverse_lock *i;
1174 for (i = &tdb->travlocks; i; i = i->next)
1177 return (count == 1 ? tdb_brlock(tdb, off, F_UNLCK, F_SETLKW, 0) : 0);
1180 /* actually delete an entry in the database given the offset */
1181 static int do_delete(TDB_CONTEXT *tdb, tdb_off rec_ptr, struct list_struct*rec)
1183 tdb_off last_ptr, i;
1184 struct list_struct lastrec;
1186 if (tdb->read_only) return -1;
1188 if (write_lock_record(tdb, rec_ptr) == -1) {
1189 /* Someone traversing here: mark it as dead */
1190 rec->magic = TDB_DEAD_MAGIC;
1191 return rec_write(tdb, rec_ptr, rec);
1193 if (write_unlock_record(tdb, rec_ptr) != 0)
1196 /* find previous record in hash chain */
1197 if (ofs_read(tdb, TDB_HASH_TOP(rec->full_hash), &i) == -1)
1199 for (last_ptr = 0; i != rec_ptr; last_ptr = i, i = lastrec.next)
1200 if (rec_read(tdb, i, &lastrec) == -1)
1203 /* unlink it: next ptr is at start of record. */
1205 last_ptr = TDB_HASH_TOP(rec->full_hash);
1206 if (ofs_write(tdb, last_ptr, &rec->next) == -1)
1209 /* recover the space */
1210 if (tdb_free(tdb, rec_ptr, rec) == -1)
1215 /* Uses traverse lock: 0 = finish, -1 = error, other = record offset */
1216 static int tdb_next_lock(TDB_CONTEXT *tdb, struct tdb_traverse_lock *tlock,
1217 struct list_struct *rec)
1219 int want_next = (tlock->off != 0);
1221 /* No traversal allows if you've called tdb_lockkeys() */
1222 if (tdb->lockedkeys)
1223 return TDB_ERRCODE(TDB_ERR_NOLOCK, -1);
1225 /* Lock each chain from the start one. */
1226 for (; tlock->hash < tdb->header.hash_size; tlock->hash++) {
1227 if (tdb_lock(tdb, tlock->hash, F_WRLCK) == -1)
1230 /* No previous record? Start at top of chain. */
1232 if (ofs_read(tdb, TDB_HASH_TOP(tlock->hash),
1236 /* Otherwise unlock the previous record. */
1237 if (unlock_record(tdb, tlock->off) != 0)
1242 /* We have offset of old record: grab next */
1243 if (rec_read(tdb, tlock->off, rec) == -1)
1245 tlock->off = rec->next;
1248 /* Iterate through chain */
1249 while( tlock->off) {
1251 if (rec_read(tdb, tlock->off, rec) == -1)
1253 if (!TDB_DEAD(rec)) {
1254 /* Woohoo: we found one! */
1255 if (lock_record(tdb, tlock->off) != 0)
1259 /* Try to clean dead ones from old traverses */
1260 current = tlock->off;
1261 tlock->off = rec->next;
1262 if (do_delete(tdb, current, rec) != 0)
1265 tdb_unlock(tdb, tlock->hash, F_WRLCK);
1268 /* We finished iteration without finding anything */
1269 return TDB_ERRCODE(TDB_SUCCESS, 0);
1273 if (tdb_unlock(tdb, tlock->hash, F_WRLCK) != 0)
1274 TDB_LOG((tdb, 0, "tdb_next_lock: On error unlock failed!\n"));
1278 /* traverse the entire database - calling fn(tdb, key, data) on each element.
1279 return -1 on error or the record count traversed
1280 if fn is NULL then it is not called
1281 a non-zero return value from fn() indicates that the traversal should stop
1283 int tdb_traverse(TDB_CONTEXT *tdb, tdb_traverse_func fn, void *state)
1286 struct list_struct rec;
1287 struct tdb_traverse_lock tl = { NULL, 0, 0 };
1290 /* This was in the initializaton, above, but the IRIX compiler
1291 * did not like it. crh
1293 tl.next = tdb->travlocks.next;
1295 /* fcntl locks don't stack: beware traverse inside traverse */
1296 tdb->travlocks.next = &tl;
1298 /* tdb_next_lock places locks on the record returned, and its chain */
1299 while ((ret = tdb_next_lock(tdb, &tl, &rec)) > 0) {
1301 /* now read the full record */
1302 key.dptr = tdb_alloc_read(tdb, tl.off + sizeof(rec),
1303 rec.key_len + rec.data_len);
1306 if (tdb_unlock(tdb, tl.hash, F_WRLCK) != 0)
1308 if (unlock_record(tdb, tl.off) != 0)
1309 TDB_LOG((tdb, 0, "tdb_traverse: key.dptr == NULL and unlock_record failed!\n"));
1312 key.dsize = rec.key_len;
1313 dbuf.dptr = key.dptr + rec.key_len;
1314 dbuf.dsize = rec.data_len;
1316 /* Drop chain lock, call out */
1317 if (tdb_unlock(tdb, tl.hash, F_WRLCK) != 0) {
1321 if (fn && fn(tdb, key, dbuf, state)) {
1322 /* They want us to terminate traversal */
1324 if (unlock_record(tdb, tl.off) != 0) {
1325 TDB_LOG((tdb, 0, "tdb_traverse: unlock_record failed!\n"));;
1328 tdb->travlocks.next = tl.next;
1329 SAFE_FREE(key.dptr);
1332 SAFE_FREE(key.dptr);
1335 tdb->travlocks.next = tl.next;
1342 /* find the first entry in the database and return its key */
1343 TDB_DATA tdb_firstkey(TDB_CONTEXT *tdb)
1346 struct list_struct rec;
1348 /* release any old lock */
1349 if (unlock_record(tdb, tdb->travlocks.off) != 0)
1351 tdb->travlocks.off = tdb->travlocks.hash = 0;
1353 if (tdb_next_lock(tdb, &tdb->travlocks, &rec) <= 0)
1355 /* now read the key */
1356 key.dsize = rec.key_len;
1357 key.dptr =tdb_alloc_read(tdb,tdb->travlocks.off+sizeof(rec),key.dsize);
1358 if (tdb_unlock(tdb, BUCKET(tdb->travlocks.hash), F_WRLCK) != 0)
1359 TDB_LOG((tdb, 0, "tdb_firstkey: error occurred while tdb_unlocking!\n"));
1363 /* find the next entry in the database, returning its key */
1364 TDB_DATA tdb_nextkey(TDB_CONTEXT *tdb, TDB_DATA oldkey)
1367 TDB_DATA key = tdb_null;
1368 struct list_struct rec;
1371 /* Is locked key the old key? If so, traverse will be reliable. */
1372 if (tdb->travlocks.off) {
1373 if (tdb_lock(tdb,tdb->travlocks.hash,F_WRLCK))
1375 if (rec_read(tdb, tdb->travlocks.off, &rec) == -1
1376 || !(k = tdb_alloc_read(tdb,tdb->travlocks.off+sizeof(rec),
1378 || memcmp(k, oldkey.dptr, oldkey.dsize) != 0) {
1379 /* No, it wasn't: unlock it and start from scratch */
1380 if (unlock_record(tdb, tdb->travlocks.off) != 0)
1382 if (tdb_unlock(tdb, tdb->travlocks.hash, F_WRLCK) != 0)
1384 tdb->travlocks.off = 0;
1390 if (!tdb->travlocks.off) {
1391 /* No previous element: do normal find, and lock record */
1392 tdb->travlocks.off = tdb_find_lock(tdb, oldkey, F_WRLCK, &rec);
1393 if (!tdb->travlocks.off)
1395 tdb->travlocks.hash = BUCKET(rec.full_hash);
1396 if (lock_record(tdb, tdb->travlocks.off) != 0) {
1397 TDB_LOG((tdb, 0, "tdb_nextkey: lock_record failed (%s)!\n", strerror(errno)));
1401 oldhash = tdb->travlocks.hash;
1403 /* Grab next record: locks chain and returned record,
1404 unlocks old record */
1405 if (tdb_next_lock(tdb, &tdb->travlocks, &rec) > 0) {
1406 key.dsize = rec.key_len;
1407 key.dptr = tdb_alloc_read(tdb, tdb->travlocks.off+sizeof(rec),
1409 /* Unlock the chain of this new record */
1410 if (tdb_unlock(tdb, tdb->travlocks.hash, F_WRLCK) != 0)
1411 TDB_LOG((tdb, 0, "tdb_nextkey: WARNING tdb_unlock failed!\n"));
1413 /* Unlock the chain of old record */
1414 if (tdb_unlock(tdb, BUCKET(oldhash), F_WRLCK) != 0)
1415 TDB_LOG((tdb, 0, "tdb_nextkey: WARNING tdb_unlock failed!\n"));
1419 /* delete an entry in the database given a key */
1420 int tdb_delete(TDB_CONTEXT *tdb, TDB_DATA key)
1423 struct list_struct rec;
1426 if (!(rec_ptr = tdb_find_lock(tdb, key, F_WRLCK, &rec)))
1428 ret = do_delete(tdb, rec_ptr, &rec);
1429 if (tdb_unlock(tdb, BUCKET(rec.full_hash), F_WRLCK) != 0)
1430 TDB_LOG((tdb, 0, "tdb_delete: WARNING tdb_unlock failed!\n"));
1434 /* store an element in the database, replacing any existing element
1437 return 0 on success, -1 on failure
1439 int tdb_store(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, int flag)
1441 struct list_struct rec;
1447 /* find which hash bucket it is in */
1448 hash = tdb_hash(&key);
1449 if (!tdb_keylocked(tdb, hash))
1451 if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1)
1454 /* check for it existing, on insert. */
1455 if (flag == TDB_INSERT) {
1456 if (tdb_exists(tdb, key)) {
1457 tdb->ecode = TDB_ERR_EXISTS;
1461 /* first try in-place update, on modify or replace. */
1462 if (tdb_update(tdb, key, dbuf) == 0)
1464 if (flag == TDB_MODIFY && tdb->ecode == TDB_ERR_NOEXIST)
1467 /* reset the error code potentially set by the tdb_update() */
1468 tdb->ecode = TDB_SUCCESS;
1470 /* delete any existing record - if it doesn't exist we don't
1471 care. Doing this first reduces fragmentation, and avoids
1472 coalescing with `allocated' block before it's updated. */
1473 if (flag != TDB_INSERT)
1474 tdb_delete(tdb, key);
1476 /* Copy key+value *before* allocating free space in case malloc
1477 fails and we are left with a dead spot in the tdb. */
1479 if (!(p = (char *)malloc(key.dsize + dbuf.dsize))) {
1480 tdb->ecode = TDB_ERR_OOM;
1484 memcpy(p, key.dptr, key.dsize);
1486 memcpy(p+key.dsize, dbuf.dptr, dbuf.dsize);
1488 /* now we're into insert / modify / replace of a record which
1489 * we know could not be optimised by an in-place store (for
1490 * various reasons). */
1491 if (!(rec_ptr = tdb_allocate(tdb, key.dsize + dbuf.dsize, &rec)))
1494 /* Read hash top into next ptr */
1495 if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec.next) == -1)
1498 rec.key_len = key.dsize;
1499 rec.data_len = dbuf.dsize;
1500 rec.full_hash = hash;
1501 rec.magic = TDB_MAGIC;
1503 /* write out and point the top of the hash chain at it */
1504 if (rec_write(tdb, rec_ptr, &rec) == -1
1505 || tdb_write(tdb, rec_ptr+sizeof(rec), p, key.dsize+dbuf.dsize)==-1
1506 || ofs_write(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) {
1507 /* Need to tdb_unallocate() here */
1512 tdb_unlock(tdb, BUCKET(hash), F_WRLCK);
1519 /* Attempt to append data to an entry in place - this only works if the new data size
1520 is <= the old data size and the key exists.
1521 on failure return -1. Record must be locked before calling.
1523 static int tdb_append_inplace(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA new_dbuf)
1525 struct list_struct rec;
1529 if (!(rec_ptr = tdb_find(tdb, key, tdb_hash(&key), &rec)))
1532 /* Append of 0 is always ok. */
1533 if (new_dbuf.dsize == 0)
1536 /* must be long enough for key, old data + new data and tailer */
1537 if (rec.rec_len < key.dsize + rec.data_len + new_dbuf.dsize + sizeof(tdb_off)) {
1539 tdb->ecode = TDB_SUCCESS; /* Not really an error */
1543 if (tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len + rec.data_len,
1544 new_dbuf.dptr, new_dbuf.dsize) == -1)
1548 rec.data_len += new_dbuf.dsize;
1549 return rec_write(tdb, rec_ptr, &rec);
1552 /* Append to an entry. Create if not exist. */
1554 int tdb_append(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA new_dbuf)
1556 struct list_struct rec;
1561 size_t new_data_size = 0;
1563 /* find which hash bucket it is in */
1564 hash = tdb_hash(&key);
1565 if (!tdb_keylocked(tdb, hash))
1567 if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1)
1570 /* first try in-place. */
1571 if (tdb_append_inplace(tdb, key, new_dbuf) == 0)
1574 /* reset the error code potentially set by the tdb_append_inplace() */
1575 tdb->ecode = TDB_SUCCESS;
1578 if (!(rec_ptr = tdb_find(tdb, key, hash, &rec))) {
1579 if (tdb->ecode != TDB_ERR_NOEXIST)
1582 /* Not found - create. */
1584 ret = tdb_store(tdb, key, new_dbuf, TDB_INSERT);
1588 new_data_size = rec.data_len + new_dbuf.dsize;
1590 /* Copy key+old_value+value *before* allocating free space in case malloc
1591 fails and we are left with a dead spot in the tdb. */
1593 if (!(p = (char *)malloc(key.dsize + new_data_size))) {
1594 tdb->ecode = TDB_ERR_OOM;
1598 /* Copy the key in place. */
1599 memcpy(p, key.dptr, key.dsize);
1601 /* Now read the old data into place. */
1603 tdb_read(tdb, rec_ptr + sizeof(rec) + rec.key_len, p + key.dsize, rec.data_len, 0) == -1)
1606 /* Finally append the new data. */
1608 memcpy(p+key.dsize+rec.data_len, new_dbuf.dptr, new_dbuf.dsize);
1610 /* delete any existing record - if it doesn't exist we don't
1611 care. Doing this first reduces fragmentation, and avoids
1612 coalescing with `allocated' block before it's updated. */
1614 tdb_delete(tdb, key);
1616 if (!(rec_ptr = tdb_allocate(tdb, key.dsize + new_data_size, &rec)))
1619 /* Read hash top into next ptr */
1620 if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec.next) == -1)
1623 rec.key_len = key.dsize;
1624 rec.data_len = new_data_size;
1625 rec.full_hash = hash;
1626 rec.magic = TDB_MAGIC;
1628 /* write out and point the top of the hash chain at it */
1629 if (rec_write(tdb, rec_ptr, &rec) == -1
1630 || tdb_write(tdb, rec_ptr+sizeof(rec), p, key.dsize+new_data_size)==-1
1631 || ofs_write(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) {
1632 /* Need to tdb_unallocate() here */
1638 tdb_unlock(tdb, BUCKET(hash), F_WRLCK);
1646 static int tdb_already_open(dev_t device,
1651 for (i = tdbs; i; i = i->next) {
1652 if (i->device == device && i->inode == ino) {
1660 /* open the database, creating it if necessary
1662 The open_flags and mode are passed straight to the open call on the
1663 database file. A flags value of O_WRONLY is invalid. The hash size
1664 is advisory, use zero for a default value.
1666 Return is NULL on error, in which case errno is also set. Don't
1667 try to call tdb_error or tdb_errname, just do strerror(errno).
1669 @param name may be NULL for internal databases. */
1670 TDB_CONTEXT *tdb_open(const char *name, int hash_size, int tdb_flags,
1671 int open_flags, mode_t mode)
1673 return tdb_open_ex(name, hash_size, tdb_flags, open_flags, mode, NULL);
1677 TDB_CONTEXT *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
1678 int open_flags, mode_t mode,
1679 tdb_log_func log_fn)
1683 int rev = 0, locked;
1687 if (!(tdb = calloc(1, sizeof *tdb))) {
1688 /* Can't log this */
1694 tdb->map_ptr = NULL;
1695 tdb->lockedkeys = NULL;
1696 tdb->flags = tdb_flags;
1697 tdb->open_flags = open_flags;
1698 tdb->log_fn = log_fn;
1700 if ((open_flags & O_ACCMODE) == O_WRONLY) {
1701 TDB_LOG((tdb, 0, "tdb_open_ex: can't open tdb %s write-only\n",
1708 hash_size = DEFAULT_HASH_SIZE;
1709 if ((open_flags & O_ACCMODE) == O_RDONLY) {
1711 /* read only databases don't do locking or clear if first */
1712 tdb->flags |= TDB_NOLOCK;
1713 tdb->flags &= ~TDB_CLEAR_IF_FIRST;
1716 /* internal databases don't mmap or lock, and start off cleared */
1717 if (tdb->flags & TDB_INTERNAL) {
1718 tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
1719 tdb->flags &= ~TDB_CLEAR_IF_FIRST;
1720 if (tdb_new_database(tdb, hash_size) != 0) {
1721 TDB_LOG((tdb, 0, "tdb_open_ex: tdb_new_database failed!"));
1727 if ((tdb->fd = open(name, open_flags, mode)) == -1) {
1728 TDB_LOG((tdb, 5, "tdb_open_ex: could not open file %s: %s\n",
1729 name, strerror(errno)));
1730 goto fail; /* errno set by open(2) */
1733 /* ensure there is only one process initialising at once */
1734 if (tdb_brlock(tdb, GLOBAL_LOCK, F_WRLCK, F_SETLKW, 0) == -1) {
1735 TDB_LOG((tdb, 0, "tdb_open_ex: failed to get global lock on %s: %s\n",
1736 name, strerror(errno)));
1737 goto fail; /* errno set by tdb_brlock */
1740 /* we need to zero database if we are the only one with it open */
1741 if ((locked = (tdb_brlock(tdb, ACTIVE_LOCK, F_WRLCK, F_SETLK, 0) == 0))
1742 && (tdb_flags & TDB_CLEAR_IF_FIRST)) {
1743 open_flags |= O_CREAT;
1744 if (ftruncate(tdb->fd, 0) == -1) {
1745 TDB_LOG((tdb, 0, "tdb_open_ex: "
1746 "failed to truncate %s: %s\n",
1747 name, strerror(errno)));
1748 goto fail; /* errno set by ftruncate */
1752 if (read(tdb->fd, &tdb->header, sizeof(tdb->header)) != sizeof(tdb->header)
1753 || strcmp(tdb->header.magic_food, TDB_MAGIC_FOOD) != 0
1754 || (tdb->header.version != TDB_VERSION
1755 && !(rev = (tdb->header.version==TDB_BYTEREV(TDB_VERSION))))) {
1756 /* its not a valid database - possibly initialise it */
1757 if (!(open_flags & O_CREAT) || tdb_new_database(tdb, hash_size) == -1) {
1758 errno = EIO; /* ie bad format or something */
1761 rev = (tdb->flags & TDB_CONVERT);
1763 vp = (unsigned char *)&tdb->header.version;
1764 vertest = (((u32)vp[0]) << 24) | (((u32)vp[1]) << 16) |
1765 (((u32)vp[2]) << 8) | (u32)vp[3];
1766 tdb->flags |= (vertest==TDB_VERSION) ? TDB_BIGENDIAN : 0;
1768 tdb->flags &= ~TDB_CONVERT;
1770 tdb->flags |= TDB_CONVERT;
1771 convert(&tdb->header, sizeof(tdb->header));
1773 if (fstat(tdb->fd, &st) == -1)
1776 /* Is it already in the open list? If so, fail. */
1777 if (tdb_already_open(st.st_dev, st.st_ino)) {
1778 TDB_LOG((tdb, 2, "tdb_open_ex: "
1779 "%s (%d,%d) is already open in this process\n",
1780 name, st.st_dev, st.st_ino));
1785 if (!(tdb->name = (char *)strdup(name))) {
1790 tdb->map_size = st.st_size;
1791 tdb->device = st.st_dev;
1792 tdb->inode = st.st_ino;
1793 tdb->locked = calloc(tdb->header.hash_size+1, sizeof(tdb->locked[0]));
1795 TDB_LOG((tdb, 2, "tdb_open_ex: "
1796 "failed to allocate lock structure for %s\n",
1803 if (!tdb->read_only)
1804 if (tdb_clear_spinlocks(tdb) != 0) {
1805 TDB_LOG((tdb, 0, "tdb_open_ex: "
1806 "failed to clear spinlock\n"));
1809 if (tdb_brlock(tdb, ACTIVE_LOCK, F_UNLCK, F_SETLK, 0) == -1) {
1810 TDB_LOG((tdb, 0, "tdb_open_ex: "
1811 "failed to take ACTIVE_LOCK on %s: %s\n",
1812 name, strerror(errno)));
1816 /* leave this lock in place to indicate it's in use */
1817 if (tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0) == -1)
1821 /* Internal (memory-only) databases skip all the code above to
1822 * do with disk files, and resume here by releasing their
1823 * global lock and hooking into the active list. */
1824 if (tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0) == -1)
1831 { int save_errno = errno;
1837 if (tdb->flags & TDB_INTERNAL)
1838 SAFE_FREE(tdb->map_ptr);
1842 SAFE_FREE(tdb->name);
1844 if (close(tdb->fd) != 0)
1845 TDB_LOG((tdb, 5, "tdb_open_ex: failed to close tdb->fd on error!\n"));
1846 SAFE_FREE(tdb->locked);
1856 * @returns -1 for error; 0 for success.
1858 int tdb_close(TDB_CONTEXT *tdb)
1864 if (tdb->flags & TDB_INTERNAL)
1865 SAFE_FREE(tdb->map_ptr);
1869 SAFE_FREE(tdb->name);
1871 ret = close(tdb->fd);
1872 SAFE_FREE(tdb->locked);
1873 SAFE_FREE(tdb->lockedkeys);
1875 /* Remove from contexts list */
1876 for (i = &tdbs; *i; i = &(*i)->next) {
1883 memset(tdb, 0, sizeof(*tdb));
1889 /* lock/unlock entire database */
1890 int tdb_lockall(TDB_CONTEXT *tdb)
1894 /* There are no locks on read-only dbs */
1896 return TDB_ERRCODE(TDB_ERR_LOCK, -1);
1897 if (tdb->lockedkeys)
1898 return TDB_ERRCODE(TDB_ERR_NOLOCK, -1);
1899 for (i = 0; i < tdb->header.hash_size; i++)
1900 if (tdb_lock(tdb, i, F_WRLCK))
1903 /* If error, release locks we have... */
1904 if (i < tdb->header.hash_size) {
1907 for ( j = 0; j < i; j++)
1908 tdb_unlock(tdb, j, F_WRLCK);
1909 return TDB_ERRCODE(TDB_ERR_NOLOCK, -1);
1914 void tdb_unlockall(TDB_CONTEXT *tdb)
1917 for (i=0; i < tdb->header.hash_size; i++)
1918 tdb_unlock(tdb, i, F_WRLCK);
1921 int tdb_lockkeys(TDB_CONTEXT *tdb, u32 number, TDB_DATA keys[])
1925 /* Can't lock more keys if already locked */
1926 if (tdb->lockedkeys)
1927 return TDB_ERRCODE(TDB_ERR_NOLOCK, -1);
1928 if (!(tdb->lockedkeys = malloc(sizeof(u32) * (number+1))))
1929 return TDB_ERRCODE(TDB_ERR_OOM, -1);
1930 /* First number in array is # keys */
1931 tdb->lockedkeys[0] = number;
1933 /* Insertion sort by bucket */
1934 for (i = 0; i < number; i++) {
1935 hash = tdb_hash(&keys[i]);
1936 for (j = 0; j < i && BUCKET(tdb->lockedkeys[j+1]) < BUCKET(hash); j++);
1937 memmove(&tdb->lockedkeys[j+2], &tdb->lockedkeys[j+1], sizeof(u32) * (i-j));
1938 tdb->lockedkeys[j+1] = hash;
1940 /* Finally, lock in order */
1941 for (i = 0; i < number; i++)
1942 if (tdb_lock(tdb, i, F_WRLCK))
1945 /* If error, release locks we have... */
1947 for ( j = 0; j < i; j++)
1948 tdb_unlock(tdb, j, F_WRLCK);
1949 SAFE_FREE(tdb->lockedkeys);
1950 return TDB_ERRCODE(TDB_ERR_NOLOCK, -1);
1955 /* Unlock the keys previously locked by tdb_lockkeys() */
1956 void tdb_unlockkeys(TDB_CONTEXT *tdb)
1959 if (!tdb->lockedkeys)
1961 for (i = 0; i < tdb->lockedkeys[0]; i++)
1962 tdb_unlock(tdb, tdb->lockedkeys[i+1], F_WRLCK);
1963 SAFE_FREE(tdb->lockedkeys);
1966 /* lock/unlock one hash chain. This is meant to be used to reduce
1967 contention - it cannot guarantee how many records will be locked */
1968 int tdb_chainlock(TDB_CONTEXT *tdb, TDB_DATA key)
1970 return tdb_lock(tdb, BUCKET(tdb_hash(&key)), F_WRLCK);
1973 int tdb_chainunlock(TDB_CONTEXT *tdb, TDB_DATA key)
1975 return tdb_unlock(tdb, BUCKET(tdb_hash(&key)), F_WRLCK);
1979 static int tdb_chainlock_read(TDB_CONTEXT *tdb, TDB_DATA key)
1981 return tdb_lock(tdb, BUCKET(tdb_hash(&key)), F_RDLCK);
1986 static int tdb_chainunlock_read(TDB_CONTEXT *tdb, TDB_DATA key)
1988 return tdb_unlock(tdb, BUCKET(tdb_hash(&key)), F_RDLCK);
1992 /* register a loging function */
1993 void tdb_logging_function(TDB_CONTEXT *tdb, void (*fn)(TDB_CONTEXT *, int , const char *, ...))
1999 /* reopen a tdb - this is used after a fork to ensure that we have an independent
2000 seek pointer from our parent and to re-establish locks */
2001 int tdb_reopen(TDB_CONTEXT *tdb)
2005 if (tdb_munmap(tdb) != 0) {
2006 TDB_LOG((tdb, 0, "tdb_reopen: munmap failed (%s)\n", strerror(errno)));
2009 if (close(tdb->fd) != 0)
2010 TDB_LOG((tdb, 0, "tdb_reopen: WARNING closing tdb->fd failed!\n"));
2011 tdb->fd = open(tdb->name, tdb->open_flags & ~(O_CREAT|O_TRUNC), 0);
2012 if (tdb->fd == -1) {
2013 TDB_LOG((tdb, 0, "tdb_reopen: open failed (%s)\n", strerror(errno)));
2016 if (fstat(tdb->fd, &st) != 0) {
2017 TDB_LOG((tdb, 0, "tdb_reopen: fstat failed (%s)\n", strerror(errno)));
2020 if (st.st_ino != tdb->inode || st.st_dev != tdb->device) {
2021 TDB_LOG((tdb, 0, "tdb_reopen: file dev/inode has changed!\n"));
2025 if (tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0) == -1) {
2026 TDB_LOG((tdb, 0, "tdb_reopen: failed to obtain active lock\n"));
2037 /* reopen all tdb's */
2038 int tdb_reopen_all(void)
2042 for (tdb=tdbs; tdb; tdb = tdb->next) {
2043 if (tdb_reopen(tdb) != 0) return -1;