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.
67 #include "lib/tdb/include/tdb.h"
68 #include "system/time.h"
69 #include "system/shmem.h"
70 #include "system/filesys.h"
73 #define TDB_MAGIC_FOOD "TDB file\n"
74 #define TDB_VERSION (0x26011967 + 6)
75 #define TDB_MAGIC (0x26011999U)
76 #define TDB_FREE_MAGIC (~TDB_MAGIC)
77 #define TDB_DEAD_MAGIC (0xFEE1DEAD)
78 #define TDB_ALIGNMENT 4
79 #define MIN_REC_SIZE (2*sizeof(struct list_struct) + TDB_ALIGNMENT)
80 #define DEFAULT_HASH_SIZE 131
81 #define TDB_PAGE_SIZE 0x2000
82 #define FREELIST_TOP (sizeof(struct tdb_header))
83 #define TDB_ALIGN(x,a) (((x) + (a)-1) & ~((a)-1))
84 #define TDB_BYTEREV(x) (((((x)&0xff)<<24)|((x)&0xFF00)<<8)|(((x)>>8)&0xFF00)|((x)>>24))
85 #define TDB_DEAD(r) ((r)->magic == TDB_DEAD_MAGIC)
86 #define TDB_BAD_MAGIC(r) ((r)->magic != TDB_MAGIC && !TDB_DEAD(r))
87 #define TDB_HASH_TOP(hash) (FREELIST_TOP + (BUCKET(hash)+1)*sizeof(tdb_off))
88 #define TDB_DATA_START(hash_size) (TDB_HASH_TOP(hash_size-1) + TDB_SPINLOCK_SIZE(hash_size))
91 /* NB assumes there is a local variable called "tdb" that is the
92 * current context, also takes doubly-parenthesized print-style
94 #define TDB_LOG(x) tdb->log_fn x
105 #define MAP_FAILED ((void *)-1)
108 /* free memory if the pointer is valid and zero the pointer */
110 #define SAFE_FREE(x) do { if ((x) != NULL) {free((x)); (x)=NULL;} } while(0)
113 #define BUCKET(hash) ((hash) % tdb->header.hash_size)
116 /* all contexts, to ensure no double-opens (fcntl locks don't nest!) */
117 static TDB_CONTEXT *tdbs = NULL;
119 static int tdb_munmap(TDB_CONTEXT *tdb)
121 if (tdb->flags & TDB_INTERNAL)
126 int ret = munmap(tdb->map_ptr, tdb->map_size);
135 static void tdb_mmap(TDB_CONTEXT *tdb)
137 if (tdb->flags & TDB_INTERNAL)
141 if (!(tdb->flags & TDB_NOMMAP)) {
142 tdb->map_ptr = mmap(NULL, tdb->map_size,
143 PROT_READ|(tdb->read_only? 0:PROT_WRITE),
144 MAP_SHARED|MAP_FILE, tdb->fd, 0);
147 * NB. When mmap fails it returns MAP_FAILED *NOT* NULL !!!!
150 if (tdb->map_ptr == MAP_FAILED) {
152 TDB_LOG((tdb, 2, "tdb_mmap failed for size %d (%s)\n",
153 tdb->map_size, strerror(errno)));
163 /* Endian conversion: we only ever deal with 4 byte quantities */
164 static void *convert(void *buf, u32 size)
167 for (i = 0; i < size / 4; i++)
168 p[i] = TDB_BYTEREV(p[i]);
171 #define DOCONV() (tdb->flags & TDB_CONVERT)
172 #define CONVERT(x) (DOCONV() ? convert(&x, sizeof(x)) : &x)
174 /* the body of the database is made of one list_struct for the free space
175 plus a separate data list for each hash value */
177 tdb_off next; /* offset of the next record in the list */
178 tdb_len rec_len; /* total byte length of record */
179 tdb_len key_len; /* byte length of key */
180 tdb_len data_len; /* byte length of data */
181 u32 full_hash; /* the full 32 bit hash of the key */
182 u32 magic; /* try to catch errors */
183 /* the following union is implied:
185 char record[rec_len];
190 u32 totalsize; (tailer)
195 /* a byte range locking function - return 0 on success
196 this functions locks/unlocks 1 byte at the specified offset.
198 On error, errno is also set so that errors are passed back properly
199 through tdb_open(). */
200 static int tdb_brlock(TDB_CONTEXT *tdb, tdb_off offset,
201 int rw_type, int lck_type, int probe)
206 if (tdb->flags & TDB_NOLOCK)
208 if ((rw_type == F_WRLCK) && (tdb->read_only)) {
214 fl.l_whence = SEEK_SET;
220 ret = fcntl(tdb->fd,lck_type,&fl);
221 } while (ret == -1 && errno == EINTR);
224 if (!probe && lck_type != F_SETLK) {
225 /* Ensure error code is set for log fun to examine. */
226 tdb->ecode = TDB_ERR_LOCK;
227 TDB_LOG((tdb, 5,"tdb_brlock failed (fd=%d) at offset %d rw_type=%d lck_type=%d\n",
228 tdb->fd, offset, rw_type, lck_type));
230 /* Generic lock error. errno set by fcntl.
231 * EAGAIN is an expected return from non-blocking
233 if (errno != EAGAIN) {
234 TDB_LOG((tdb, 5, "tdb_brlock failed (fd=%d) at offset %d rw_type=%d lck_type=%d: %s\n",
235 tdb->fd, offset, rw_type, lck_type,
238 return TDB_ERRCODE(TDB_ERR_LOCK, -1);
243 /* lock a list in the database. list -1 is the alloc list */
244 static int tdb_lock(TDB_CONTEXT *tdb, int list, int ltype)
246 if (list < -1 || list >= (int)tdb->header.hash_size) {
247 TDB_LOG((tdb, 0,"tdb_lock: invalid list %d for ltype=%d\n",
251 if (tdb->flags & TDB_NOLOCK)
254 /* Since fcntl locks don't nest, we do a lock for the first one,
255 and simply bump the count for future ones */
256 if (tdb->locked[list+1].count == 0) {
257 if (!tdb->read_only && tdb->header.rwlocks) {
258 if (tdb_spinlock(tdb, list, ltype)) {
259 TDB_LOG((tdb, 0, "tdb_lock spinlock failed on list %d ltype=%d\n",
263 } else if (tdb_brlock(tdb,FREELIST_TOP+4*list,ltype,F_SETLKW, 0)) {
264 TDB_LOG((tdb, 0,"tdb_lock failed on list %d ltype=%d (%s)\n",
265 list, ltype, strerror(errno)));
268 tdb->locked[list+1].ltype = ltype;
270 tdb->locked[list+1].count++;
274 /* unlock the database: returns void because it's too late for errors. */
275 /* changed to return int it may be interesting to know there
276 has been an error --simo */
277 static int tdb_unlock(TDB_CONTEXT *tdb, int list, int ltype)
281 if (tdb->flags & TDB_NOLOCK)
285 if (list < -1 || list >= (int)tdb->header.hash_size) {
286 TDB_LOG((tdb, 0, "tdb_unlock: list %d invalid (%d)\n", list, tdb->header.hash_size));
290 if (tdb->locked[list+1].count==0) {
291 TDB_LOG((tdb, 0, "tdb_unlock: count is 0\n"));
295 if (tdb->locked[list+1].count == 1) {
296 /* Down to last nested lock: unlock underneath */
297 if (!tdb->read_only && tdb->header.rwlocks) {
298 ret = tdb_spinunlock(tdb, list, ltype);
300 ret = tdb_brlock(tdb, FREELIST_TOP+4*list, F_UNLCK, F_SETLKW, 0);
305 tdb->locked[list+1].count--;
308 TDB_LOG((tdb, 0,"tdb_unlock: An error occurred unlocking!\n"));
312 /* This is based on the hash algorithm from gdbm */
313 static u32 default_tdb_hash(TDB_DATA *key)
315 u32 value; /* Used to compute the hash value. */
316 u32 i; /* Used to cycle through random values. */
318 /* Set the initial value from the key size. */
319 for (value = 0x238F13AF * key->dsize, i=0; i < key->dsize; i++)
320 value = (value + (key->dptr[i] << (i*5 % 24)));
322 return (1103515243 * value + 12345);
325 /* check for an out of bounds access - if it is out of bounds then
326 see if the database has been expanded by someone else and expand
328 note that "len" is the minimum length needed for the db
330 static int tdb_oob(TDB_CONTEXT *tdb, tdb_off len, int probe)
333 if (len <= tdb->map_size)
335 if (tdb->flags & TDB_INTERNAL) {
337 /* Ensure ecode is set for log fn. */
338 tdb->ecode = TDB_ERR_IO;
339 TDB_LOG((tdb, 0,"tdb_oob len %d beyond internal malloc size %d\n",
340 (int)len, (int)tdb->map_size));
342 return TDB_ERRCODE(TDB_ERR_IO, -1);
345 if (fstat(tdb->fd, &st) == -1)
346 return TDB_ERRCODE(TDB_ERR_IO, -1);
348 if (st.st_size < (size_t)len) {
350 /* Ensure ecode is set for log fn. */
351 tdb->ecode = TDB_ERR_IO;
352 TDB_LOG((tdb, 0,"tdb_oob len %d beyond eof at %d\n",
353 (int)len, (int)st.st_size));
355 return TDB_ERRCODE(TDB_ERR_IO, -1);
358 /* Unmap, update size, remap */
359 if (tdb_munmap(tdb) == -1)
360 return TDB_ERRCODE(TDB_ERR_IO, -1);
361 tdb->map_size = st.st_size;
366 /* write a lump of data at a specified offset */
367 static int tdb_write(TDB_CONTEXT *tdb, tdb_off off, void *buf, tdb_len len)
369 if (tdb_oob(tdb, off + len, 0) != 0)
373 memcpy(off + (char *)tdb->map_ptr, buf, len);
375 else if (pwrite(tdb->fd, buf, len, off) != (ssize_t)len) {
377 else if (lseek(tdb->fd, off, SEEK_SET) != off
378 || write(tdb->fd, buf, len) != (ssize_t)len) {
380 /* Ensure ecode is set for log fn. */
381 tdb->ecode = TDB_ERR_IO;
382 TDB_LOG((tdb, 0,"tdb_write failed at %d len=%d (%s)\n",
383 off, len, strerror(errno)));
384 return TDB_ERRCODE(TDB_ERR_IO, -1);
389 /* read a lump of data at a specified offset, maybe convert */
390 static int tdb_read(TDB_CONTEXT *tdb,tdb_off off,void *buf,tdb_len len,int cv)
392 if (tdb_oob(tdb, off + len, 0) != 0)
396 memcpy(buf, off + (char *)tdb->map_ptr, len);
398 else if (pread(tdb->fd, buf, len, off) != (ssize_t)len) {
400 else if (lseek(tdb->fd, off, SEEK_SET) != off
401 || read(tdb->fd, buf, len) != (ssize_t)len) {
403 /* Ensure ecode is set for log fn. */
404 tdb->ecode = TDB_ERR_IO;
405 TDB_LOG((tdb, 0,"tdb_read failed at %d len=%d (%s)\n",
406 off, len, strerror(errno)));
407 return TDB_ERRCODE(TDB_ERR_IO, -1);
414 /* read a lump of data, allocating the space for it */
415 static char *tdb_alloc_read(TDB_CONTEXT *tdb, tdb_off offset, tdb_len len)
419 if (!(buf = malloc(len))) {
420 /* Ensure ecode is set for log fn. */
421 tdb->ecode = TDB_ERR_OOM;
422 TDB_LOG((tdb, 0,"tdb_alloc_read malloc failed len=%d (%s)\n",
423 len, strerror(errno)));
424 return TDB_ERRCODE(TDB_ERR_OOM, buf);
426 if (tdb_read(tdb, offset, buf, len, 0) == -1) {
433 /* read/write a tdb_off */
434 static int ofs_read(TDB_CONTEXT *tdb, tdb_off offset, tdb_off *d)
436 return tdb_read(tdb, offset, (char*)d, sizeof(*d), DOCONV());
438 static int ofs_write(TDB_CONTEXT *tdb, tdb_off offset, tdb_off *d)
441 return tdb_write(tdb, offset, CONVERT(off), sizeof(*d));
444 /* read/write a record */
445 static int rec_read(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec)
447 if (tdb_read(tdb, offset, rec, sizeof(*rec),DOCONV()) == -1)
449 if (TDB_BAD_MAGIC(rec)) {
450 /* Ensure ecode is set for log fn. */
451 tdb->ecode = TDB_ERR_CORRUPT;
452 TDB_LOG((tdb, 0,"rec_read bad magic 0x%x at offset=%d\n", rec->magic, offset));
453 return TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
455 return tdb_oob(tdb, rec->next+sizeof(*rec), 0);
457 static int rec_write(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec)
459 struct list_struct r = *rec;
460 return tdb_write(tdb, offset, CONVERT(r), sizeof(r));
463 /* read a freelist record and check for simple errors */
464 static int rec_free_read(TDB_CONTEXT *tdb, tdb_off off, struct list_struct *rec)
466 if (tdb_read(tdb, off, rec, sizeof(*rec),DOCONV()) == -1)
469 if (rec->magic == TDB_MAGIC) {
470 /* this happens when a app is showdown while deleting a record - we should
471 not completely fail when this happens */
472 TDB_LOG((tdb, 0,"rec_free_read non-free magic 0x%x at offset=%d - fixing\n",
474 rec->magic = TDB_FREE_MAGIC;
475 if (tdb_write(tdb, off, rec, sizeof(*rec)) == -1)
479 if (rec->magic != TDB_FREE_MAGIC) {
480 /* Ensure ecode is set for log fn. */
481 tdb->ecode = TDB_ERR_CORRUPT;
482 TDB_LOG((tdb, 0,"rec_free_read bad magic 0x%x at offset=%d\n",
484 return TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
486 if (tdb_oob(tdb, rec->next+sizeof(*rec), 0) != 0)
491 /* update a record tailer (must hold allocation lock) */
492 static int update_tailer(TDB_CONTEXT *tdb, tdb_off offset,
493 const struct list_struct *rec)
497 /* Offset of tailer from record header */
498 totalsize = sizeof(*rec) + rec->rec_len;
499 return ofs_write(tdb, offset + totalsize - sizeof(tdb_off),
503 static tdb_off tdb_dump_record(TDB_CONTEXT *tdb, tdb_off offset)
505 struct list_struct rec;
506 tdb_off tailer_ofs, tailer;
508 if (tdb_read(tdb, offset, (char *)&rec, sizeof(rec), DOCONV()) == -1) {
509 printf("ERROR: failed to read record at %u\n", offset);
513 printf(" rec: offset=0x%08x next=0x%08x rec_len=%d key_len=%d data_len=%d full_hash=0x%x magic=0x%x\n",
514 offset, rec.next, rec.rec_len, rec.key_len, rec.data_len, rec.full_hash, rec.magic);
516 tailer_ofs = offset + sizeof(rec) + rec.rec_len - sizeof(tdb_off);
517 if (ofs_read(tdb, tailer_ofs, &tailer) == -1) {
518 printf("ERROR: failed to read tailer at %u\n", tailer_ofs);
522 if (tailer != rec.rec_len + sizeof(rec)) {
523 printf("ERROR: tailer does not match record! tailer=%u totalsize=%u\n",
524 (unsigned int)tailer, (unsigned int)(rec.rec_len + sizeof(rec)));
529 static int tdb_dump_chain(TDB_CONTEXT *tdb, int i)
531 tdb_off rec_ptr, top;
533 top = TDB_HASH_TOP(i);
535 if (tdb_lock(tdb, i, F_WRLCK) != 0)
538 if (ofs_read(tdb, top, &rec_ptr) == -1)
539 return tdb_unlock(tdb, i, F_WRLCK);
542 printf("hash=%d\n", i);
545 rec_ptr = tdb_dump_record(tdb, rec_ptr);
548 return tdb_unlock(tdb, i, F_WRLCK);
551 void tdb_dump_all(TDB_CONTEXT *tdb)
554 for (i=0;i<tdb->header.hash_size;i++) {
555 tdb_dump_chain(tdb, i);
557 printf("freelist:\n");
558 tdb_dump_chain(tdb, -1);
561 int tdb_printfreelist(TDB_CONTEXT *tdb)
565 tdb_off offset, rec_ptr;
566 struct list_struct rec;
568 if ((ret = tdb_lock(tdb, -1, F_WRLCK)) != 0)
571 offset = FREELIST_TOP;
573 /* read in the freelist top */
574 if (ofs_read(tdb, offset, &rec_ptr) == -1) {
575 tdb_unlock(tdb, -1, F_WRLCK);
579 printf("freelist top=[0x%08x]\n", rec_ptr );
581 if (tdb_read(tdb, rec_ptr, (char *)&rec, sizeof(rec), DOCONV()) == -1) {
582 tdb_unlock(tdb, -1, F_WRLCK);
586 if (rec.magic != TDB_FREE_MAGIC) {
587 printf("bad magic 0x%08x in free list\n", rec.magic);
588 tdb_unlock(tdb, -1, F_WRLCK);
592 printf("entry offset=[0x%08x], rec.rec_len = [0x%08x (%d)] (end = 0x%08x)\n",
593 rec_ptr, rec.rec_len, rec.rec_len, rec_ptr + rec.rec_len);
594 total_free += rec.rec_len;
596 /* move to the next record */
599 printf("total rec_len = [0x%08x (%d)]\n", (int)total_free,
602 return tdb_unlock(tdb, -1, F_WRLCK);
605 /* Remove an element from the freelist. Must have alloc lock. */
606 static int remove_from_freelist(TDB_CONTEXT *tdb, tdb_off off, tdb_off next)
610 /* read in the freelist top */
611 last_ptr = FREELIST_TOP;
612 while (ofs_read(tdb, last_ptr, &i) != -1 && i != 0) {
614 /* We've found it! */
615 return ofs_write(tdb, last_ptr, &next);
617 /* Follow chain (next offset is at start of record) */
620 TDB_LOG((tdb, 0,"remove_from_freelist: not on list at off=%d\n", off));
621 return TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
624 /* Add an element into the freelist. Merge adjacent records if
626 static int tdb_free(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec)
630 /* Allocation and tailer lock */
631 if (tdb_lock(tdb, -1, F_WRLCK) != 0)
634 /* set an initial tailer, so if we fail we don't leave a bogus record */
635 if (update_tailer(tdb, offset, rec) != 0) {
636 TDB_LOG((tdb, 0, "tdb_free: upfate_tailer failed!\n"));
640 /* Look right first (I'm an Australian, dammit) */
641 right = offset + sizeof(*rec) + rec->rec_len;
642 if (right + sizeof(*rec) <= tdb->map_size) {
643 struct list_struct r;
645 if (tdb_read(tdb, right, &r, sizeof(r), DOCONV()) == -1) {
646 TDB_LOG((tdb, 0, "tdb_free: right read failed at %u\n", right));
650 /* If it's free, expand to include it. */
651 if (r.magic == TDB_FREE_MAGIC) {
652 if (remove_from_freelist(tdb, right, r.next) == -1) {
653 TDB_LOG((tdb, 0, "tdb_free: right free failed at %u\n", right));
656 rec->rec_len += sizeof(r) + r.rec_len;
662 left = offset - sizeof(tdb_off);
663 if (left > TDB_DATA_START(tdb->header.hash_size)) {
664 struct list_struct l;
667 /* Read in tailer and jump back to header */
668 if (ofs_read(tdb, left, &leftsize) == -1) {
669 TDB_LOG((tdb, 0, "tdb_free: left offset read failed at %u\n", left));
672 left = offset - leftsize;
674 /* Now read in record */
675 if (tdb_read(tdb, left, &l, sizeof(l), DOCONV()) == -1) {
676 TDB_LOG((tdb, 0, "tdb_free: left read failed at %u (%u)\n", left, leftsize));
680 /* If it's free, expand to include it. */
681 if (l.magic == TDB_FREE_MAGIC) {
682 if (remove_from_freelist(tdb, left, l.next) == -1) {
683 TDB_LOG((tdb, 0, "tdb_free: left free failed at %u\n", left));
687 rec->rec_len += leftsize;
693 if (update_tailer(tdb, offset, rec) == -1) {
694 TDB_LOG((tdb, 0, "tdb_free: update_tailer failed at %u\n", offset));
698 /* Now, prepend to free list */
699 rec->magic = TDB_FREE_MAGIC;
701 if (ofs_read(tdb, FREELIST_TOP, &rec->next) == -1 ||
702 rec_write(tdb, offset, rec) == -1 ||
703 ofs_write(tdb, FREELIST_TOP, &offset) == -1) {
704 TDB_LOG((tdb, 0, "tdb_free record write failed at offset=%d\n", offset));
708 /* And we're done. */
709 tdb_unlock(tdb, -1, F_WRLCK);
713 tdb_unlock(tdb, -1, F_WRLCK);
718 /* expand a file. we prefer to use ftruncate, as that is what posix
719 says to use for mmap expansion */
720 static int expand_file(TDB_CONTEXT *tdb, tdb_off size, tdb_off addition)
723 #if HAVE_FTRUNCATE_EXTEND
724 if (ftruncate(tdb->fd, size+addition) != 0) {
725 TDB_LOG((tdb, 0, "expand_file ftruncate to %d failed (%s)\n",
726 size+addition, strerror(errno)));
733 if (pwrite(tdb->fd, &b, 1, (size+addition) - 1) != 1) {
735 if (lseek(tdb->fd, (size+addition) - 1, SEEK_SET) != (size+addition) - 1 ||
736 write(tdb->fd, &b, 1) != 1) {
738 TDB_LOG((tdb, 0, "expand_file to %d failed (%s)\n",
739 size+addition, strerror(errno)));
744 /* now fill the file with something. This ensures that the file isn't sparse, which would be
745 very bad if we ran out of disk. This must be done with write, not via mmap */
746 memset(buf, 0x42, sizeof(buf));
748 int n = addition>sizeof(buf)?sizeof(buf):addition;
750 int ret = pwrite(tdb->fd, buf, n, size);
753 if (lseek(tdb->fd, size, SEEK_SET) != size)
755 ret = write(tdb->fd, buf, n);
758 TDB_LOG((tdb, 0, "expand_file write of %d failed (%s)\n",
759 n, strerror(errno)));
769 /* expand the database at least size bytes by expanding the underlying
770 file and doing the mmap again if necessary */
771 static int tdb_expand(TDB_CONTEXT *tdb, tdb_off size)
773 struct list_struct rec;
776 if (tdb_lock(tdb, -1, F_WRLCK) == -1) {
777 TDB_LOG((tdb, 0, "lock failed in tdb_expand\n"));
781 /* must know about any previous expansions by another process */
782 tdb_oob(tdb, tdb->map_size + 1, 1);
784 /* always make room for at least 10 more records, and round
785 the database up to a multiple of TDB_PAGE_SIZE */
786 size = TDB_ALIGN(tdb->map_size + size*10, TDB_PAGE_SIZE) - tdb->map_size;
788 if (!(tdb->flags & TDB_INTERNAL))
792 * We must ensure the file is unmapped before doing this
793 * to ensure consistency with systems like OpenBSD where
794 * writes and mmaps are not consistent.
797 /* expand the file itself */
798 if (!(tdb->flags & TDB_INTERNAL)) {
799 if (expand_file(tdb, tdb->map_size, size) != 0)
803 tdb->map_size += size;
805 if (tdb->flags & TDB_INTERNAL) {
806 char *new_map_ptr = realloc(tdb->map_ptr, tdb->map_size);
808 tdb->map_size -= size;
811 tdb->map_ptr = new_map_ptr;
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);
841 the core of tdb_allocate - called when we have decided which
842 free list entry to use
844 static tdb_off tdb_allocate_ofs(TDB_CONTEXT *tdb, tdb_len length, tdb_off rec_ptr,
845 struct list_struct *rec, tdb_off last_ptr)
847 struct list_struct newrec;
850 memset(&newrec, '\0', sizeof(newrec));
852 /* found it - now possibly split it up */
853 if (rec->rec_len > length + MIN_REC_SIZE) {
854 /* Length of left piece */
855 length = TDB_ALIGN(length, TDB_ALIGNMENT);
857 /* Right piece to go on free list */
858 newrec.rec_len = rec->rec_len - (sizeof(*rec) + length);
859 newrec_ptr = rec_ptr + sizeof(*rec) + length;
861 /* And left record is shortened */
862 rec->rec_len = length;
867 /* Remove allocated record from the free list */
868 if (ofs_write(tdb, last_ptr, &rec->next) == -1) {
872 /* Update header: do this before we drop alloc
873 lock, otherwise tdb_free() might try to
874 merge with us, thinking we're free.
875 (Thanks Jeremy Allison). */
876 rec->magic = TDB_MAGIC;
877 if (rec_write(tdb, rec_ptr, rec) == -1) {
881 /* Did we create new block? */
883 /* Update allocated record tailer (we
885 if (update_tailer(tdb, rec_ptr, rec) == -1) {
889 /* Free new record */
890 if (tdb_free(tdb, newrec_ptr, &newrec) == -1) {
895 /* all done - return the new record offset */
899 /* allocate some space from the free list. The offset returned points
900 to a unconnected list_struct within the database with room for at
901 least length bytes of total data
903 0 is returned if the space could not be allocated
905 static tdb_off tdb_allocate(TDB_CONTEXT *tdb, tdb_len length,
906 struct list_struct *rec)
908 tdb_off rec_ptr, last_ptr, newrec_ptr;
910 tdb_off rec_ptr, last_ptr;
914 if (tdb_lock(tdb, -1, F_WRLCK) == -1)
917 /* Extra bytes required for tailer */
918 length += sizeof(tdb_off);
921 last_ptr = FREELIST_TOP;
923 /* read in the freelist top */
924 if (ofs_read(tdb, FREELIST_TOP, &rec_ptr) == -1)
930 this is a best fit allocation strategy. Originally we used
931 a first fit strategy, but it suffered from massive fragmentation
932 issues when faced with a slowly increasing record size.
935 if (rec_free_read(tdb, rec_ptr, rec) == -1) {
939 if (rec->rec_len >= length) {
940 if (bestfit.rec_ptr == 0 ||
941 rec->rec_len < bestfit.rec_len) {
942 bestfit.rec_len = rec->rec_len;
943 bestfit.rec_ptr = rec_ptr;
944 bestfit.last_ptr = last_ptr;
945 /* consider a fit to be good enough if we aren't wasting more than half the space */
946 if (bestfit.rec_len < 2*length) {
952 /* move to the next record */
957 if (bestfit.rec_ptr != 0) {
958 if (rec_free_read(tdb, bestfit.rec_ptr, rec) == -1) {
962 newrec_ptr = tdb_allocate_ofs(tdb, length, bestfit.rec_ptr, rec, bestfit.last_ptr);
963 tdb_unlock(tdb, -1, F_WRLCK);
967 /* we didn't find enough space. See if we can expand the
968 database and if we can then try again */
969 if (tdb_expand(tdb, length + sizeof(*rec)) == 0)
972 tdb_unlock(tdb, -1, F_WRLCK);
976 /* initialise a new database with a specified hash size */
977 static int tdb_new_database(TDB_CONTEXT *tdb, int hash_size)
979 struct tdb_header *newdb;
982 /* We make it up in memory, then write it out if not internal */
983 size = sizeof(struct tdb_header) + (hash_size+1)*sizeof(tdb_off);
984 if (!(newdb = calloc(size, 1)))
985 return TDB_ERRCODE(TDB_ERR_OOM, -1);
987 /* Fill in the header */
988 newdb->version = TDB_VERSION;
989 newdb->hash_size = hash_size;
991 newdb->rwlocks = size;
993 if (tdb->flags & TDB_INTERNAL) {
994 tdb->map_size = size;
995 tdb->map_ptr = (char *)newdb;
996 memcpy(&tdb->header, newdb, sizeof(tdb->header));
997 /* Convert the `ondisk' version if asked. */
1001 if (lseek(tdb->fd, 0, SEEK_SET) == -1)
1004 if (ftruncate(tdb->fd, 0) == -1)
1007 /* This creates an endian-converted header, as if read from disk */
1009 memcpy(&tdb->header, newdb, sizeof(tdb->header));
1010 /* Don't endian-convert the magic food! */
1011 memcpy(newdb->magic_food, TDB_MAGIC_FOOD, strlen(TDB_MAGIC_FOOD)+1);
1012 if (write(tdb->fd, newdb, size) != size)
1015 ret = tdb_create_rwlocks(tdb->fd, hash_size);
1022 /* Returns 0 on fail. On success, return offset of record, and fills
1024 static tdb_off tdb_find(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash,
1025 struct list_struct *r)
1029 /* read in the hash top */
1030 if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1)
1033 /* keep looking until we find the right record */
1035 if (rec_read(tdb, rec_ptr, r) == -1)
1038 if (!TDB_DEAD(r) && hash==r->full_hash && key.dsize==r->key_len) {
1040 /* a very likely hit - read the key */
1041 k = tdb_alloc_read(tdb, rec_ptr + sizeof(*r),
1046 if (memcmp(key.dptr, k, key.dsize) == 0) {
1054 return TDB_ERRCODE(TDB_ERR_NOEXIST, 0);
1057 /* As tdb_find, but if you succeed, keep the lock */
1058 static tdb_off tdb_find_lock_hash(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash, int locktype,
1059 struct list_struct *rec)
1063 if (tdb_lock(tdb, BUCKET(hash), locktype) == -1)
1065 if (!(rec_ptr = tdb_find(tdb, key, hash, rec)))
1066 tdb_unlock(tdb, BUCKET(hash), locktype);
1070 enum TDB_ERROR tdb_error(TDB_CONTEXT *tdb)
1075 static struct tdb_errname {
1076 enum TDB_ERROR ecode; const char *estring;
1077 } emap[] = { {TDB_SUCCESS, "Success"},
1078 {TDB_ERR_CORRUPT, "Corrupt database"},
1079 {TDB_ERR_IO, "IO Error"},
1080 {TDB_ERR_LOCK, "Locking error"},
1081 {TDB_ERR_OOM, "Out of memory"},
1082 {TDB_ERR_EXISTS, "Record exists"},
1083 {TDB_ERR_NOLOCK, "Lock exists on other keys"},
1084 {TDB_ERR_NOEXIST, "Record does not exist"} };
1086 /* Error string for the last tdb error */
1087 const char *tdb_errorstr(TDB_CONTEXT *tdb)
1090 for (i = 0; i < sizeof(emap) / sizeof(struct tdb_errname); i++)
1091 if (tdb->ecode == emap[i].ecode)
1092 return emap[i].estring;
1093 return "Invalid error code";
1096 /* update an entry in place - this only works if the new data size
1097 is <= the old data size and the key exists.
1098 on failure return -1.
1101 static int tdb_update_hash(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash, TDB_DATA dbuf)
1103 struct list_struct rec;
1107 if (!(rec_ptr = tdb_find(tdb, key, hash, &rec)))
1110 /* must be long enough key, data and tailer */
1111 if (rec.rec_len < key.dsize + dbuf.dsize + sizeof(tdb_off)) {
1112 tdb->ecode = TDB_SUCCESS; /* Not really an error */
1116 if (tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len,
1117 dbuf.dptr, dbuf.dsize) == -1)
1120 if (dbuf.dsize != rec.data_len) {
1122 rec.data_len = dbuf.dsize;
1123 return rec_write(tdb, rec_ptr, &rec);
1129 /* find an entry in the database given a key */
1130 /* If an entry doesn't exist tdb_err will be set to
1131 * TDB_ERR_NOEXIST. If a key has no data attached
1132 * then the TDB_DATA will have zero length but
1133 * a non-zero pointer
1136 TDB_DATA tdb_fetch(TDB_CONTEXT *tdb, TDB_DATA key)
1139 struct list_struct rec;
1143 /* find which hash bucket it is in */
1144 hash = tdb->hash_fn(&key);
1145 if (!(rec_ptr = tdb_find_lock_hash(tdb,key,hash,F_RDLCK,&rec)))
1148 ret.dptr = tdb_alloc_read(tdb, rec_ptr + sizeof(rec) + rec.key_len,
1150 ret.dsize = rec.data_len;
1151 tdb_unlock(tdb, BUCKET(rec.full_hash), F_RDLCK);
1155 /* check if an entry in the database exists
1157 note that 1 is returned if the key is found and 0 is returned if not found
1158 this doesn't match the conventions in the rest of this module, but is
1159 compatible with gdbm
1161 static int tdb_exists_hash(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash)
1163 struct list_struct rec;
1165 if (tdb_find_lock_hash(tdb, key, hash, F_RDLCK, &rec) == 0)
1167 tdb_unlock(tdb, BUCKET(rec.full_hash), F_RDLCK);
1171 int tdb_exists(TDB_CONTEXT *tdb, TDB_DATA key)
1173 u32 hash = tdb->hash_fn(&key);
1174 return tdb_exists_hash(tdb, key, hash);
1177 /* record lock stops delete underneath */
1178 static int lock_record(TDB_CONTEXT *tdb, tdb_off off)
1180 return off ? tdb_brlock(tdb, off, F_RDLCK, F_SETLKW, 0) : 0;
1183 Write locks override our own fcntl readlocks, so check it here.
1184 Note this is meant to be F_SETLK, *not* F_SETLKW, as it's not
1185 an error to fail to get the lock here.
1188 static int write_lock_record(TDB_CONTEXT *tdb, tdb_off off)
1190 struct tdb_traverse_lock *i;
1191 for (i = &tdb->travlocks; i; i = i->next)
1194 return tdb_brlock(tdb, off, F_WRLCK, F_SETLK, 1);
1198 Note this is meant to be F_SETLK, *not* F_SETLKW, as it's not
1199 an error to fail to get the lock here.
1202 static int write_unlock_record(TDB_CONTEXT *tdb, tdb_off off)
1204 return tdb_brlock(tdb, off, F_UNLCK, F_SETLK, 0);
1206 /* fcntl locks don't stack: avoid unlocking someone else's */
1207 static int unlock_record(TDB_CONTEXT *tdb, tdb_off off)
1209 struct tdb_traverse_lock *i;
1214 for (i = &tdb->travlocks; i; i = i->next)
1217 return (count == 1 ? tdb_brlock(tdb, off, F_UNLCK, F_SETLKW, 0) : 0);
1220 /* actually delete an entry in the database given the offset */
1221 static int do_delete(TDB_CONTEXT *tdb, tdb_off rec_ptr, struct list_struct*rec)
1223 tdb_off last_ptr, i;
1224 struct list_struct lastrec;
1226 if (tdb->read_only) return -1;
1228 if (write_lock_record(tdb, rec_ptr) == -1) {
1229 /* Someone traversing here: mark it as dead */
1230 rec->magic = TDB_DEAD_MAGIC;
1231 return rec_write(tdb, rec_ptr, rec);
1233 if (write_unlock_record(tdb, rec_ptr) != 0)
1236 /* find previous record in hash chain */
1237 if (ofs_read(tdb, TDB_HASH_TOP(rec->full_hash), &i) == -1)
1239 for (last_ptr = 0; i != rec_ptr; last_ptr = i, i = lastrec.next)
1240 if (rec_read(tdb, i, &lastrec) == -1)
1243 /* unlink it: next ptr is at start of record. */
1245 last_ptr = TDB_HASH_TOP(rec->full_hash);
1246 if (ofs_write(tdb, last_ptr, &rec->next) == -1)
1249 /* recover the space */
1250 if (tdb_free(tdb, rec_ptr, rec) == -1)
1255 /* Uses traverse lock: 0 = finish, -1 = error, other = record offset */
1256 static int tdb_next_lock(TDB_CONTEXT *tdb, struct tdb_traverse_lock *tlock,
1257 struct list_struct *rec)
1259 int want_next = (tlock->off != 0);
1261 /* Lock each chain from the start one. */
1262 for (; tlock->hash < tdb->header.hash_size; tlock->hash++) {
1263 if (tdb_lock(tdb, tlock->hash, F_WRLCK) == -1)
1266 /* No previous record? Start at top of chain. */
1268 if (ofs_read(tdb, TDB_HASH_TOP(tlock->hash),
1272 /* Otherwise unlock the previous record. */
1273 if (unlock_record(tdb, tlock->off) != 0)
1278 /* We have offset of old record: grab next */
1279 if (rec_read(tdb, tlock->off, rec) == -1)
1281 tlock->off = rec->next;
1284 /* Iterate through chain */
1285 while( tlock->off) {
1287 if (rec_read(tdb, tlock->off, rec) == -1)
1289 if (!TDB_DEAD(rec)) {
1290 /* Woohoo: we found one! */
1291 if (lock_record(tdb, tlock->off) != 0)
1296 /* Detect infinite loops. From "Shlomi Yaakobovich" <Shlomi@exanet.com>. */
1297 if (tlock->off == rec->next) {
1298 TDB_LOG((tdb, 0, "tdb_next_lock: loop detected.\n"));
1302 /* Try to clean dead ones from old traverses */
1303 current = tlock->off;
1304 tlock->off = rec->next;
1305 if (!tdb->read_only &&
1306 do_delete(tdb, current, rec) != 0)
1309 tdb_unlock(tdb, tlock->hash, F_WRLCK);
1312 /* We finished iteration without finding anything */
1313 return TDB_ERRCODE(TDB_SUCCESS, 0);
1317 if (tdb_unlock(tdb, tlock->hash, F_WRLCK) != 0)
1318 TDB_LOG((tdb, 0, "tdb_next_lock: On error unlock failed!\n"));
1322 /* traverse the entire database - calling fn(tdb, key, data) on each element.
1323 return -1 on error or the record count traversed
1324 if fn is NULL then it is not called
1325 a non-zero return value from fn() indicates that the traversal should stop
1327 int tdb_traverse(TDB_CONTEXT *tdb, tdb_traverse_func fn, void *private)
1330 struct list_struct rec;
1331 struct tdb_traverse_lock tl = { NULL, 0, 0 };
1334 /* This was in the initializaton, above, but the IRIX compiler
1335 * did not like it. crh
1337 tl.next = tdb->travlocks.next;
1339 /* fcntl locks don't stack: beware traverse inside traverse */
1340 tdb->travlocks.next = &tl;
1342 /* tdb_next_lock places locks on the record returned, and its chain */
1343 while ((ret = tdb_next_lock(tdb, &tl, &rec)) > 0) {
1345 /* now read the full record */
1346 key.dptr = tdb_alloc_read(tdb, tl.off + sizeof(rec),
1347 rec.key_len + rec.data_len);
1350 if (tdb_unlock(tdb, tl.hash, F_WRLCK) != 0)
1352 if (unlock_record(tdb, tl.off) != 0)
1353 TDB_LOG((tdb, 0, "tdb_traverse: key.dptr == NULL and unlock_record failed!\n"));
1356 key.dsize = rec.key_len;
1357 dbuf.dptr = key.dptr + rec.key_len;
1358 dbuf.dsize = rec.data_len;
1360 /* Drop chain lock, call out */
1361 if (tdb_unlock(tdb, tl.hash, F_WRLCK) != 0) {
1365 if (fn && fn(tdb, key, dbuf, private)) {
1366 /* They want us to terminate traversal */
1368 if (unlock_record(tdb, tl.off) != 0) {
1369 TDB_LOG((tdb, 0, "tdb_traverse: unlock_record failed!\n"));;
1372 tdb->travlocks.next = tl.next;
1373 SAFE_FREE(key.dptr);
1376 SAFE_FREE(key.dptr);
1379 tdb->travlocks.next = tl.next;
1386 /* find the first entry in the database and return its key */
1387 TDB_DATA tdb_firstkey(TDB_CONTEXT *tdb)
1390 struct list_struct rec;
1392 /* release any old lock */
1393 if (unlock_record(tdb, tdb->travlocks.off) != 0)
1395 tdb->travlocks.off = tdb->travlocks.hash = 0;
1397 if (tdb_next_lock(tdb, &tdb->travlocks, &rec) <= 0)
1399 /* now read the key */
1400 key.dsize = rec.key_len;
1401 key.dptr =tdb_alloc_read(tdb,tdb->travlocks.off+sizeof(rec),key.dsize);
1402 if (tdb_unlock(tdb, BUCKET(tdb->travlocks.hash), F_WRLCK) != 0)
1403 TDB_LOG((tdb, 0, "tdb_firstkey: error occurred while tdb_unlocking!\n"));
1407 /* find the next entry in the database, returning its key */
1408 TDB_DATA tdb_nextkey(TDB_CONTEXT *tdb, TDB_DATA oldkey)
1411 TDB_DATA key = tdb_null;
1412 struct list_struct rec;
1415 /* Is locked key the old key? If so, traverse will be reliable. */
1416 if (tdb->travlocks.off) {
1417 if (tdb_lock(tdb,tdb->travlocks.hash,F_WRLCK))
1419 if (rec_read(tdb, tdb->travlocks.off, &rec) == -1
1420 || !(k = tdb_alloc_read(tdb,tdb->travlocks.off+sizeof(rec),
1422 || memcmp(k, oldkey.dptr, oldkey.dsize) != 0) {
1423 /* No, it wasn't: unlock it and start from scratch */
1424 if (unlock_record(tdb, tdb->travlocks.off) != 0)
1426 if (tdb_unlock(tdb, tdb->travlocks.hash, F_WRLCK) != 0)
1428 tdb->travlocks.off = 0;
1434 if (!tdb->travlocks.off) {
1435 /* No previous element: do normal find, and lock record */
1436 tdb->travlocks.off = tdb_find_lock_hash(tdb, oldkey, tdb->hash_fn(&oldkey), F_WRLCK, &rec);
1437 if (!tdb->travlocks.off)
1439 tdb->travlocks.hash = BUCKET(rec.full_hash);
1440 if (lock_record(tdb, tdb->travlocks.off) != 0) {
1441 TDB_LOG((tdb, 0, "tdb_nextkey: lock_record failed (%s)!\n", strerror(errno)));
1445 oldhash = tdb->travlocks.hash;
1447 /* Grab next record: locks chain and returned record,
1448 unlocks old record */
1449 if (tdb_next_lock(tdb, &tdb->travlocks, &rec) > 0) {
1450 key.dsize = rec.key_len;
1451 key.dptr = tdb_alloc_read(tdb, tdb->travlocks.off+sizeof(rec),
1453 /* Unlock the chain of this new record */
1454 if (tdb_unlock(tdb, tdb->travlocks.hash, F_WRLCK) != 0)
1455 TDB_LOG((tdb, 0, "tdb_nextkey: WARNING tdb_unlock failed!\n"));
1457 /* Unlock the chain of old record */
1458 if (tdb_unlock(tdb, BUCKET(oldhash), F_WRLCK) != 0)
1459 TDB_LOG((tdb, 0, "tdb_nextkey: WARNING tdb_unlock failed!\n"));
1463 /* delete an entry in the database given a key */
1464 static int tdb_delete_hash(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash)
1467 struct list_struct rec;
1470 if (!(rec_ptr = tdb_find_lock_hash(tdb, key, hash, F_WRLCK, &rec)))
1472 ret = do_delete(tdb, rec_ptr, &rec);
1473 if (tdb_unlock(tdb, BUCKET(rec.full_hash), F_WRLCK) != 0)
1474 TDB_LOG((tdb, 0, "tdb_delete: WARNING tdb_unlock failed!\n"));
1478 int tdb_delete(TDB_CONTEXT *tdb, TDB_DATA key)
1480 u32 hash = tdb->hash_fn(&key);
1481 return tdb_delete_hash(tdb, key, hash);
1484 /* store an element in the database, replacing any existing element
1487 return 0 on success, -1 on failure
1489 int tdb_store(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, int flag)
1491 struct list_struct rec;
1497 /* find which hash bucket it is in */
1498 hash = tdb->hash_fn(&key);
1499 if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1)
1502 /* check for it existing, on insert. */
1503 if (flag == TDB_INSERT) {
1504 if (tdb_exists_hash(tdb, key, hash)) {
1505 tdb->ecode = TDB_ERR_EXISTS;
1509 /* first try in-place update, on modify or replace. */
1510 if (tdb_update_hash(tdb, key, hash, dbuf) == 0)
1512 if (tdb->ecode == TDB_ERR_NOEXIST &&
1513 flag == TDB_MODIFY) {
1514 /* if the record doesn't exist and we are in TDB_MODIFY mode then
1515 we should fail the store */
1519 /* reset the error code potentially set by the tdb_update() */
1520 tdb->ecode = TDB_SUCCESS;
1522 /* delete any existing record - if it doesn't exist we don't
1523 care. Doing this first reduces fragmentation, and avoids
1524 coalescing with `allocated' block before it's updated. */
1525 if (flag != TDB_INSERT)
1526 tdb_delete_hash(tdb, key, hash);
1528 /* Copy key+value *before* allocating free space in case malloc
1529 fails and we are left with a dead spot in the tdb. */
1531 if (!(p = (char *)malloc(key.dsize + dbuf.dsize))) {
1532 tdb->ecode = TDB_ERR_OOM;
1536 memcpy(p, key.dptr, key.dsize);
1538 memcpy(p+key.dsize, dbuf.dptr, dbuf.dsize);
1540 /* we have to allocate some space */
1541 if (!(rec_ptr = tdb_allocate(tdb, key.dsize + dbuf.dsize, &rec)))
1544 /* Read hash top into next ptr */
1545 if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec.next) == -1)
1548 rec.key_len = key.dsize;
1549 rec.data_len = dbuf.dsize;
1550 rec.full_hash = hash;
1551 rec.magic = TDB_MAGIC;
1553 /* write out and point the top of the hash chain at it */
1554 if (rec_write(tdb, rec_ptr, &rec) == -1
1555 || tdb_write(tdb, rec_ptr+sizeof(rec), p, key.dsize+dbuf.dsize)==-1
1556 || ofs_write(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) {
1557 /* Need to tdb_unallocate() here */
1562 tdb_unlock(tdb, BUCKET(hash), F_WRLCK);
1569 /* Attempt to append data to an entry in place - this only works if the new data size
1570 is <= the old data size and the key exists.
1571 on failure return -1. Record must be locked before calling.
1573 static int tdb_append_inplace(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash, TDB_DATA new_dbuf)
1575 struct list_struct rec;
1579 if (!(rec_ptr = tdb_find(tdb, key, hash, &rec)))
1582 /* Append of 0 is always ok. */
1583 if (new_dbuf.dsize == 0)
1586 /* must be long enough for key, old data + new data and tailer */
1587 if (rec.rec_len < key.dsize + rec.data_len + new_dbuf.dsize + sizeof(tdb_off)) {
1589 tdb->ecode = TDB_SUCCESS; /* Not really an error */
1593 if (tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len + rec.data_len,
1594 new_dbuf.dptr, new_dbuf.dsize) == -1)
1598 rec.data_len += new_dbuf.dsize;
1599 return rec_write(tdb, rec_ptr, &rec);
1602 /* Append to an entry. Create if not exist. */
1604 int tdb_append(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA new_dbuf)
1606 struct list_struct rec;
1611 size_t new_data_size = 0;
1613 /* find which hash bucket it is in */
1614 hash = tdb->hash_fn(&key);
1615 if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1)
1618 /* first try in-place. */
1619 if (tdb_append_inplace(tdb, key, hash, new_dbuf) == 0)
1622 /* reset the error code potentially set by the tdb_append_inplace() */
1623 tdb->ecode = TDB_SUCCESS;
1626 if (!(rec_ptr = tdb_find(tdb, key, hash, &rec))) {
1627 if (tdb->ecode != TDB_ERR_NOEXIST)
1630 /* Not found - create. */
1632 ret = tdb_store(tdb, key, new_dbuf, TDB_INSERT);
1636 new_data_size = rec.data_len + new_dbuf.dsize;
1638 /* Copy key+old_value+value *before* allocating free space in case malloc
1639 fails and we are left with a dead spot in the tdb. */
1641 if (!(p = (char *)malloc(key.dsize + new_data_size))) {
1642 tdb->ecode = TDB_ERR_OOM;
1646 /* Copy the key in place. */
1647 memcpy(p, key.dptr, key.dsize);
1649 /* Now read the old data into place. */
1651 tdb_read(tdb, rec_ptr + sizeof(rec) + rec.key_len, p + key.dsize, rec.data_len, 0) == -1)
1654 /* Finally append the new data. */
1656 memcpy(p+key.dsize+rec.data_len, new_dbuf.dptr, new_dbuf.dsize);
1658 /* delete any existing record - if it doesn't exist we don't
1659 care. Doing this first reduces fragmentation, and avoids
1660 coalescing with `allocated' block before it's updated. */
1662 tdb_delete_hash(tdb, key, hash);
1664 if (!(rec_ptr = tdb_allocate(tdb, key.dsize + new_data_size, &rec)))
1667 /* Read hash top into next ptr */
1668 if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec.next) == -1)
1671 rec.key_len = key.dsize;
1672 rec.data_len = new_data_size;
1673 rec.full_hash = hash;
1674 rec.magic = TDB_MAGIC;
1676 /* write out and point the top of the hash chain at it */
1677 if (rec_write(tdb, rec_ptr, &rec) == -1
1678 || tdb_write(tdb, rec_ptr+sizeof(rec), p, key.dsize+new_data_size)==-1
1679 || ofs_write(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) {
1680 /* Need to tdb_unallocate() here */
1686 tdb_unlock(tdb, BUCKET(hash), F_WRLCK);
1694 static int tdb_already_open(dev_t device,
1699 for (i = tdbs; i; i = i->next) {
1700 if (i->device == device && i->inode == ino) {
1708 /* open the database, creating it if necessary
1710 The open_flags and mode are passed straight to the open call on the
1711 database file. A flags value of O_WRONLY is invalid. The hash size
1712 is advisory, use zero for a default value.
1714 Return is NULL on error, in which case errno is also set. Don't
1715 try to call tdb_error or tdb_errname, just do strerror(errno).
1717 @param name may be NULL for internal databases. */
1718 TDB_CONTEXT *tdb_open(const char *name, int hash_size, int tdb_flags,
1719 int open_flags, mode_t mode)
1721 return tdb_open_ex(name, hash_size, tdb_flags, open_flags, mode, NULL, NULL);
1724 /* a default logging function */
1725 static void null_log_fn(TDB_CONTEXT *tdb, int level, const char *fmt, ...)
1730 TDB_CONTEXT *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
1731 int open_flags, mode_t mode,
1732 tdb_log_func log_fn,
1733 tdb_hash_func hash_fn)
1737 int rev = 0, locked = 0;
1741 if (!(tdb = calloc(1, sizeof *tdb))) {
1742 /* Can't log this */
1748 tdb->map_ptr = NULL;
1749 tdb->flags = tdb_flags;
1750 tdb->open_flags = open_flags;
1751 tdb->log_fn = log_fn?log_fn:null_log_fn;
1752 tdb->hash_fn = hash_fn ? hash_fn : default_tdb_hash;
1754 if ((open_flags & O_ACCMODE) == O_WRONLY) {
1755 TDB_LOG((tdb, 0, "tdb_open_ex: can't open tdb %s write-only\n",
1762 hash_size = DEFAULT_HASH_SIZE;
1763 if ((open_flags & O_ACCMODE) == O_RDONLY) {
1765 /* read only databases don't do locking or clear if first */
1766 tdb->flags |= TDB_NOLOCK;
1767 tdb->flags &= ~TDB_CLEAR_IF_FIRST;
1770 /* internal databases don't mmap or lock, and start off cleared */
1771 if (tdb->flags & TDB_INTERNAL) {
1772 tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
1773 tdb->flags &= ~TDB_CLEAR_IF_FIRST;
1774 if (tdb_new_database(tdb, hash_size) != 0) {
1775 TDB_LOG((tdb, 0, "tdb_open_ex: tdb_new_database failed!"));
1781 if ((tdb->fd = open(name, open_flags, mode)) == -1) {
1782 TDB_LOG((tdb, 5, "tdb_open_ex: could not open file %s: %s\n",
1783 name, strerror(errno)));
1784 goto fail; /* errno set by open(2) */
1787 /* ensure there is only one process initialising at once */
1788 if (tdb_brlock(tdb, GLOBAL_LOCK, F_WRLCK, F_SETLKW, 0) == -1) {
1789 TDB_LOG((tdb, 0, "tdb_open_ex: failed to get global lock on %s: %s\n",
1790 name, strerror(errno)));
1791 goto fail; /* errno set by tdb_brlock */
1794 /* we need to zero database if we are the only one with it open */
1795 if ((tdb_flags & TDB_CLEAR_IF_FIRST) &&
1796 (locked = (tdb_brlock(tdb, ACTIVE_LOCK, F_WRLCK, F_SETLK, 0) == 0))) {
1797 open_flags |= O_CREAT;
1798 if (ftruncate(tdb->fd, 0) == -1) {
1799 TDB_LOG((tdb, 0, "tdb_open_ex: "
1800 "failed to truncate %s: %s\n",
1801 name, strerror(errno)));
1802 goto fail; /* errno set by ftruncate */
1806 if (read(tdb->fd, &tdb->header, sizeof(tdb->header)) != sizeof(tdb->header)
1807 || strcmp(tdb->header.magic_food, TDB_MAGIC_FOOD) != 0
1808 || (tdb->header.version != TDB_VERSION
1809 && !(rev = (tdb->header.version==TDB_BYTEREV(TDB_VERSION))))) {
1810 /* its not a valid database - possibly initialise it */
1811 if (!(open_flags & O_CREAT) || tdb_new_database(tdb, hash_size) == -1) {
1812 errno = EIO; /* ie bad format or something */
1815 rev = (tdb->flags & TDB_CONVERT);
1817 vp = (uint8_t *)&tdb->header.version;
1818 vertest = (((u32)vp[0]) << 24) | (((u32)vp[1]) << 16) |
1819 (((u32)vp[2]) << 8) | (u32)vp[3];
1820 tdb->flags |= (vertest==TDB_VERSION) ? TDB_BIGENDIAN : 0;
1822 tdb->flags &= ~TDB_CONVERT;
1824 tdb->flags |= TDB_CONVERT;
1825 convert(&tdb->header, sizeof(tdb->header));
1827 if (fstat(tdb->fd, &st) == -1)
1830 /* Is it already in the open list? If so, fail. */
1831 if (tdb_already_open(st.st_dev, st.st_ino)) {
1832 TDB_LOG((tdb, 2, "tdb_open_ex: "
1833 "%s (%d,%d) is already open in this process\n",
1834 name, (int)st.st_dev, (int)st.st_ino));
1839 if (!(tdb->name = (char *)strdup(name))) {
1844 tdb->map_size = st.st_size;
1845 tdb->device = st.st_dev;
1846 tdb->inode = st.st_ino;
1847 tdb->locked = calloc(tdb->header.hash_size+1, sizeof(tdb->locked[0]));
1849 TDB_LOG((tdb, 2, "tdb_open_ex: "
1850 "failed to allocate lock structure for %s\n",
1857 if (!tdb->read_only)
1858 if (tdb_clear_spinlocks(tdb) != 0) {
1859 TDB_LOG((tdb, 0, "tdb_open_ex: "
1860 "failed to clear spinlock\n"));
1863 if (tdb_brlock(tdb, ACTIVE_LOCK, F_UNLCK, F_SETLK, 0) == -1) {
1864 TDB_LOG((tdb, 0, "tdb_open_ex: "
1865 "failed to take ACTIVE_LOCK on %s: %s\n",
1866 name, strerror(errno)));
1872 /* We always need to do this if the CLEAR_IF_FIRST flag is set, even if
1873 we didn't get the initial exclusive lock as we need to let all other
1874 users know we're using it. */
1876 if (tdb_flags & TDB_CLEAR_IF_FIRST) {
1877 /* leave this lock in place to indicate it's in use */
1878 if (tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0) == -1)
1884 /* Internal (memory-only) databases skip all the code above to
1885 * do with disk files, and resume here by releasing their
1886 * global lock and hooking into the active list. */
1887 if (tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0) == -1)
1894 { int save_errno = errno;
1900 if (tdb->flags & TDB_INTERNAL)
1901 SAFE_FREE(tdb->map_ptr);
1905 SAFE_FREE(tdb->name);
1907 if (close(tdb->fd) != 0)
1908 TDB_LOG((tdb, 5, "tdb_open_ex: failed to close tdb->fd on error!\n"));
1909 SAFE_FREE(tdb->locked);
1919 * @returns -1 for error; 0 for success.
1921 int tdb_close(TDB_CONTEXT *tdb)
1927 if (tdb->flags & TDB_INTERNAL)
1928 SAFE_FREE(tdb->map_ptr);
1932 SAFE_FREE(tdb->name);
1934 ret = close(tdb->fd);
1935 SAFE_FREE(tdb->locked);
1937 /* Remove from contexts list */
1938 for (i = &tdbs; *i; i = &(*i)->next) {
1945 memset(tdb, 0, sizeof(*tdb));
1951 /* lock/unlock entire database */
1952 int tdb_lockall(TDB_CONTEXT *tdb)
1956 /* There are no locks on read-only dbs */
1958 return TDB_ERRCODE(TDB_ERR_LOCK, -1);
1959 for (i = 0; i < tdb->header.hash_size; i++)
1960 if (tdb_lock(tdb, i, F_WRLCK))
1963 /* If error, release locks we have... */
1964 if (i < tdb->header.hash_size) {
1967 for ( j = 0; j < i; j++)
1968 tdb_unlock(tdb, j, F_WRLCK);
1969 return TDB_ERRCODE(TDB_ERR_NOLOCK, -1);
1974 void tdb_unlockall(TDB_CONTEXT *tdb)
1977 for (i=0; i < tdb->header.hash_size; i++)
1978 tdb_unlock(tdb, i, F_WRLCK);
1981 /* lock/unlock one hash chain. This is meant to be used to reduce
1982 contention - it cannot guarantee how many records will be locked */
1983 int tdb_chainlock(TDB_CONTEXT *tdb, TDB_DATA key)
1985 return tdb_lock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK);
1988 int tdb_chainunlock(TDB_CONTEXT *tdb, TDB_DATA key)
1990 return tdb_unlock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK);
1993 int tdb_chainlock_read(TDB_CONTEXT *tdb, TDB_DATA key)
1995 return tdb_lock(tdb, BUCKET(tdb->hash_fn(&key)), F_RDLCK);
1998 int tdb_chainunlock_read(TDB_CONTEXT *tdb, TDB_DATA key)
2000 return tdb_unlock(tdb, BUCKET(tdb->hash_fn(&key)), F_RDLCK);
2004 /* register a loging function */
2005 void tdb_logging_function(TDB_CONTEXT *tdb, void (*fn)(TDB_CONTEXT *, int , const char *, ...))
2007 tdb->log_fn = fn?fn:null_log_fn;
2011 /* reopen a tdb - this can be used after a fork to ensure that we have an independent
2012 seek pointer from our parent and to re-establish locks */
2013 int tdb_reopen(TDB_CONTEXT *tdb)
2017 if (tdb->flags & TDB_INTERNAL)
2018 return 0; /* Nothing to do. */
2019 if (tdb_munmap(tdb) != 0) {
2020 TDB_LOG((tdb, 0, "tdb_reopen: munmap failed (%s)\n", strerror(errno)));
2023 if (close(tdb->fd) != 0)
2024 TDB_LOG((tdb, 0, "tdb_reopen: WARNING closing tdb->fd failed!\n"));
2025 tdb->fd = open(tdb->name, tdb->open_flags & ~(O_CREAT|O_TRUNC), 0);
2026 if (tdb->fd == -1) {
2027 TDB_LOG((tdb, 0, "tdb_reopen: open failed (%s)\n", strerror(errno)));
2030 if (fstat(tdb->fd, &st) != 0) {
2031 TDB_LOG((tdb, 0, "tdb_reopen: fstat failed (%s)\n", strerror(errno)));
2034 if (st.st_ino != tdb->inode || st.st_dev != tdb->device) {
2035 TDB_LOG((tdb, 0, "tdb_reopen: file dev/inode has changed!\n"));
2039 if ((tdb->flags & TDB_CLEAR_IF_FIRST) && (tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0) == -1)) {
2040 TDB_LOG((tdb, 0, "tdb_reopen: failed to obtain active lock\n"));
2051 /* reopen all tdb's */
2052 int tdb_reopen_all(void)
2056 for (tdb=tdbs; tdb; tdb = tdb->next) {
2057 /* Ensure no clear-if-first. */
2058 tdb->flags &= ~TDB_CLEAR_IF_FIRST;
2059 if (tdb_reopen(tdb) != 0)