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5ac4a56b GKH |
1 | /* |
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 | |
8 | ||
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. | |
13 | ||
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. | |
18 | ||
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. | |
22 | */ | |
23 | ||
24 | ||
25 | /* NOTE: If you use tdbs under valgrind, and in particular if you run | |
26 | * tdbtorture, you may get spurious "uninitialized value" warnings. I | |
27 | * think this is because valgrind doesn't understand that the mmap'd | |
28 | * area may be written to by other processes. Memory can, from the | |
29 | * point of view of the grinded process, spontaneously become | |
30 | * initialized. | |
31 | * | |
32 | * I can think of a few solutions. [mbp 20030311] | |
33 | * | |
34 | * 1 - Write suppressions for Valgrind so that it doesn't complain | |
35 | * about this. Probably the most reasonable but people need to | |
36 | * remember to use them. | |
37 | * | |
38 | * 2 - Use IO not mmap when running under valgrind. Not so nice. | |
39 | * | |
40 | * 3 - Use the special valgrind macros to mark memory as valid at the | |
41 | * right time. Probably too hard -- the process just doesn't know. | |
42 | */ | |
43 | ||
aa04c7f0 GKH |
44 | /* udev defines */ |
45 | #define STANDALONE | |
46 | #define TDB_DEBUG | |
47 | #define HAVE_MMAP 1 | |
48 | ||
49 | ||
5ac4a56b GKH |
50 | #ifdef STANDALONE |
51 | #if HAVE_CONFIG_H | |
52 | #include <config.h> | |
53 | #endif | |
54 | ||
55 | #include <stdlib.h> | |
56 | #include <stdio.h> | |
57 | #include <fcntl.h> | |
58 | #include <unistd.h> | |
59 | #include <string.h> | |
60 | #include <fcntl.h> | |
61 | #include <errno.h> | |
62 | #include <sys/mman.h> | |
63 | #include <sys/stat.h> | |
64 | #include <signal.h> | |
65 | #include "tdb.h" | |
66 | #include "spinlock.h" | |
67 | #else | |
68 | #include "includes.h" | |
69 | #endif | |
70 | ||
71 | #define TDB_MAGIC_FOOD "TDB file\n" | |
72 | #define TDB_VERSION (0x26011967 + 6) | |
73 | #define TDB_MAGIC (0x26011999U) | |
74 | #define TDB_FREE_MAGIC (~TDB_MAGIC) | |
75 | #define TDB_DEAD_MAGIC (0xFEE1DEAD) | |
76 | #define TDB_ALIGNMENT 4 | |
77 | #define MIN_REC_SIZE (2*sizeof(struct list_struct) + TDB_ALIGNMENT) | |
78 | #define DEFAULT_HASH_SIZE 131 | |
79 | #define TDB_PAGE_SIZE 0x2000 | |
80 | #define FREELIST_TOP (sizeof(struct tdb_header)) | |
81 | #define TDB_ALIGN(x,a) (((x) + (a)-1) & ~((a)-1)) | |
82 | #define TDB_BYTEREV(x) (((((x)&0xff)<<24)|((x)&0xFF00)<<8)|(((x)>>8)&0xFF00)|((x)>>24)) | |
83 | #define TDB_DEAD(r) ((r)->magic == TDB_DEAD_MAGIC) | |
84 | #define TDB_BAD_MAGIC(r) ((r)->magic != TDB_MAGIC && !TDB_DEAD(r)) | |
85 | #define TDB_HASH_TOP(hash) (FREELIST_TOP + (BUCKET(hash)+1)*sizeof(tdb_off)) | |
86 | ||
87 | /* NB assumes there is a local variable called "tdb" that is the | |
88 | * current context, also takes doubly-parenthesized print-style | |
89 | * argument. */ | |
90 | #define TDB_LOG(x) (tdb->log_fn?((tdb->log_fn x),0) : 0) | |
91 | ||
92 | /* lock offsets */ | |
93 | #define GLOBAL_LOCK 0 | |
94 | #define ACTIVE_LOCK 4 | |
95 | ||
96 | #ifndef MAP_FILE | |
97 | #define MAP_FILE 0 | |
98 | #endif | |
99 | ||
100 | #ifndef MAP_FAILED | |
101 | #define MAP_FAILED ((void *)-1) | |
102 | #endif | |
103 | ||
104 | /* free memory if the pointer is valid and zero the pointer */ | |
105 | #ifndef SAFE_FREE | |
106 | #define SAFE_FREE(x) do { if ((x) != NULL) {free((x)); (x)=NULL;} } while(0) | |
107 | #endif | |
108 | ||
109 | #define BUCKET(hash) ((hash) % tdb->header.hash_size) | |
110 | TDB_DATA tdb_null; | |
111 | ||
112 | /* all contexts, to ensure no double-opens (fcntl locks don't nest!) */ | |
113 | static TDB_CONTEXT *tdbs = NULL; | |
114 | ||
115 | static int tdb_munmap(TDB_CONTEXT *tdb) | |
116 | { | |
117 | if (tdb->flags & TDB_INTERNAL) | |
118 | return 0; | |
119 | ||
120 | #ifdef HAVE_MMAP | |
121 | if (tdb->map_ptr) { | |
122 | int ret = munmap(tdb->map_ptr, tdb->map_size); | |
123 | if (ret != 0) | |
124 | return ret; | |
125 | } | |
126 | #endif | |
127 | tdb->map_ptr = NULL; | |
128 | return 0; | |
129 | } | |
130 | ||
131 | static void tdb_mmap(TDB_CONTEXT *tdb) | |
132 | { | |
133 | if (tdb->flags & TDB_INTERNAL) | |
134 | return; | |
135 | ||
136 | #ifdef HAVE_MMAP | |
137 | if (!(tdb->flags & TDB_NOMMAP)) { | |
138 | tdb->map_ptr = mmap(NULL, tdb->map_size, | |
139 | PROT_READ|(tdb->read_only? 0:PROT_WRITE), | |
140 | MAP_SHARED|MAP_FILE, tdb->fd, 0); | |
141 | ||
142 | /* | |
143 | * NB. When mmap fails it returns MAP_FAILED *NOT* NULL !!!! | |
144 | */ | |
145 | ||
146 | if (tdb->map_ptr == MAP_FAILED) { | |
147 | tdb->map_ptr = NULL; | |
148 | TDB_LOG((tdb, 2, "tdb_mmap failed for size %d (%s)\n", | |
149 | tdb->map_size, strerror(errno))); | |
150 | } | |
151 | } else { | |
152 | tdb->map_ptr = NULL; | |
153 | } | |
154 | #else | |
155 | tdb->map_ptr = NULL; | |
156 | #endif | |
157 | } | |
158 | ||
159 | /* Endian conversion: we only ever deal with 4 byte quantities */ | |
160 | static void *convert(void *buf, u32 size) | |
161 | { | |
162 | u32 i, *p = buf; | |
163 | for (i = 0; i < size / 4; i++) | |
164 | p[i] = TDB_BYTEREV(p[i]); | |
165 | return buf; | |
166 | } | |
167 | #define DOCONV() (tdb->flags & TDB_CONVERT) | |
168 | #define CONVERT(x) (DOCONV() ? convert(&x, sizeof(x)) : &x) | |
169 | ||
170 | /* the body of the database is made of one list_struct for the free space | |
171 | plus a separate data list for each hash value */ | |
172 | struct list_struct { | |
173 | tdb_off next; /* offset of the next record in the list */ | |
174 | tdb_len rec_len; /* total byte length of record */ | |
175 | tdb_len key_len; /* byte length of key */ | |
176 | tdb_len data_len; /* byte length of data */ | |
177 | u32 full_hash; /* the full 32 bit hash of the key */ | |
178 | u32 magic; /* try to catch errors */ | |
179 | /* the following union is implied: | |
180 | union { | |
181 | char record[rec_len]; | |
182 | struct { | |
183 | char key[key_len]; | |
184 | char data[data_len]; | |
185 | } | |
186 | u32 totalsize; (tailer) | |
187 | } | |
188 | */ | |
189 | }; | |
190 | ||
191 | /*************************************************************** | |
192 | Allow a caller to set a "alarm" flag that tdb can check to abort | |
193 | a blocking lock on SIGALRM. | |
194 | ***************************************************************/ | |
195 | ||
196 | static sig_atomic_t *palarm_fired; | |
197 | ||
198 | void tdb_set_lock_alarm(sig_atomic_t *palarm) | |
199 | { | |
200 | palarm_fired = palarm; | |
201 | } | |
202 | ||
203 | /* a byte range locking function - return 0 on success | |
204 | this functions locks/unlocks 1 byte at the specified offset. | |
205 | ||
206 | On error, errno is also set so that errors are passed back properly | |
207 | through tdb_open(). */ | |
208 | static int tdb_brlock(TDB_CONTEXT *tdb, tdb_off offset, | |
209 | int rw_type, int lck_type, int probe) | |
210 | { | |
211 | struct flock fl; | |
212 | int ret; | |
213 | ||
214 | if (tdb->flags & TDB_NOLOCK) | |
215 | return 0; | |
216 | if ((rw_type == F_WRLCK) && (tdb->read_only)) { | |
217 | errno = EACCES; | |
218 | return -1; | |
219 | } | |
220 | ||
221 | fl.l_type = rw_type; | |
222 | fl.l_whence = SEEK_SET; | |
223 | fl.l_start = offset; | |
224 | fl.l_len = 1; | |
225 | fl.l_pid = 0; | |
226 | ||
227 | do { | |
228 | ret = fcntl(tdb->fd,lck_type,&fl); | |
229 | if (ret == -1 && errno == EINTR && palarm_fired && *palarm_fired) | |
230 | break; | |
231 | } while (ret == -1 && errno == EINTR); | |
232 | ||
233 | if (ret == -1) { | |
234 | if (!probe && lck_type != F_SETLK) { | |
235 | /* Ensure error code is set for log fun to examine. */ | |
236 | if (errno == EINTR && palarm_fired && *palarm_fired) | |
237 | tdb->ecode = TDB_ERR_LOCK_TIMEOUT; | |
238 | else | |
239 | tdb->ecode = TDB_ERR_LOCK; | |
240 | TDB_LOG((tdb, 5,"tdb_brlock failed (fd=%d) at offset %d rw_type=%d lck_type=%d\n", | |
241 | tdb->fd, offset, rw_type, lck_type)); | |
242 | } | |
243 | /* Was it an alarm timeout ? */ | |
244 | if (errno == EINTR && palarm_fired && *palarm_fired) | |
245 | return TDB_ERRCODE(TDB_ERR_LOCK_TIMEOUT, -1); | |
246 | /* Otherwise - generic lock error. */ | |
247 | /* errno set by fcntl */ | |
248 | return TDB_ERRCODE(TDB_ERR_LOCK, -1); | |
249 | } | |
250 | return 0; | |
251 | } | |
252 | ||
253 | /* lock a list in the database. list -1 is the alloc list */ | |
254 | static int tdb_lock(TDB_CONTEXT *tdb, int list, int ltype) | |
255 | { | |
256 | if (list < -1 || list >= (int)tdb->header.hash_size) { | |
257 | TDB_LOG((tdb, 0,"tdb_lock: invalid list %d for ltype=%d\n", | |
258 | list, ltype)); | |
259 | return -1; | |
260 | } | |
261 | if (tdb->flags & TDB_NOLOCK) | |
262 | return 0; | |
263 | ||
264 | /* Since fcntl locks don't nest, we do a lock for the first one, | |
265 | and simply bump the count for future ones */ | |
266 | if (tdb->locked[list+1].count == 0) { | |
267 | if (!tdb->read_only && tdb->header.rwlocks) { | |
268 | if (tdb_spinlock(tdb, list, ltype)) { | |
269 | TDB_LOG((tdb, 0, "tdb_lock spinlock failed on list ltype=%d\n", | |
270 | list, ltype)); | |
271 | return -1; | |
272 | } | |
273 | } else if (tdb_brlock(tdb,FREELIST_TOP+4*list,ltype,F_SETLKW, 0)) { | |
274 | TDB_LOG((tdb, 0,"tdb_lock failed on list %d ltype=%d (%s)\n", | |
275 | list, ltype, strerror(errno))); | |
276 | return -1; | |
277 | } | |
278 | tdb->locked[list+1].ltype = ltype; | |
279 | } | |
280 | tdb->locked[list+1].count++; | |
281 | return 0; | |
282 | } | |
283 | ||
284 | /* unlock the database: returns void because it's too late for errors. */ | |
285 | /* changed to return int it may be interesting to know there | |
286 | has been an error --simo */ | |
287 | static int tdb_unlock(TDB_CONTEXT *tdb, int list, int ltype) | |
288 | { | |
289 | int ret = -1; | |
290 | ||
291 | if (tdb->flags & TDB_NOLOCK) | |
292 | return 0; | |
293 | ||
294 | /* Sanity checks */ | |
295 | if (list < -1 || list >= (int)tdb->header.hash_size) { | |
296 | TDB_LOG((tdb, 0, "tdb_unlock: list %d invalid (%d)\n", list, tdb->header.hash_size)); | |
297 | return ret; | |
298 | } | |
299 | ||
300 | if (tdb->locked[list+1].count==0) { | |
301 | TDB_LOG((tdb, 0, "tdb_unlock: count is 0\n")); | |
302 | return ret; | |
303 | } | |
304 | ||
305 | if (tdb->locked[list+1].count == 1) { | |
306 | /* Down to last nested lock: unlock underneath */ | |
307 | if (!tdb->read_only && tdb->header.rwlocks) { | |
308 | ret = tdb_spinunlock(tdb, list, ltype); | |
309 | } else { | |
310 | ret = tdb_brlock(tdb, FREELIST_TOP+4*list, F_UNLCK, F_SETLKW, 0); | |
311 | } | |
312 | } else { | |
313 | ret = 0; | |
314 | } | |
315 | tdb->locked[list+1].count--; | |
316 | ||
317 | if (ret) | |
318 | TDB_LOG((tdb, 0,"tdb_unlock: An error occurred unlocking!\n")); | |
319 | return ret; | |
320 | } | |
321 | ||
322 | /* This is based on the hash algorithm from gdbm */ | |
323 | static u32 tdb_hash(TDB_DATA *key) | |
324 | { | |
325 | u32 value; /* Used to compute the hash value. */ | |
326 | u32 i; /* Used to cycle through random values. */ | |
327 | ||
328 | /* Set the initial value from the key size. */ | |
329 | for (value = 0x238F13AF * key->dsize, i=0; i < key->dsize; i++) | |
330 | value = (value + (key->dptr[i] << (i*5 % 24))); | |
331 | ||
332 | return (1103515243 * value + 12345); | |
333 | } | |
334 | ||
335 | /* check for an out of bounds access - if it is out of bounds then | |
336 | see if the database has been expanded by someone else and expand | |
337 | if necessary | |
338 | note that "len" is the minimum length needed for the db | |
339 | */ | |
340 | static int tdb_oob(TDB_CONTEXT *tdb, tdb_off len, int probe) | |
341 | { | |
342 | struct stat st; | |
343 | if (len <= tdb->map_size) | |
344 | return 0; | |
345 | if (tdb->flags & TDB_INTERNAL) { | |
346 | if (!probe) { | |
347 | /* Ensure ecode is set for log fn. */ | |
348 | tdb->ecode = TDB_ERR_IO; | |
349 | TDB_LOG((tdb, 0,"tdb_oob len %d beyond internal malloc size %d\n", | |
350 | (int)len, (int)tdb->map_size)); | |
351 | } | |
352 | return TDB_ERRCODE(TDB_ERR_IO, -1); | |
353 | } | |
354 | ||
355 | if (fstat(tdb->fd, &st) == -1) | |
356 | return TDB_ERRCODE(TDB_ERR_IO, -1); | |
357 | ||
358 | if (st.st_size < (size_t)len) { | |
359 | if (!probe) { | |
360 | /* Ensure ecode is set for log fn. */ | |
361 | tdb->ecode = TDB_ERR_IO; | |
362 | TDB_LOG((tdb, 0,"tdb_oob len %d beyond eof at %d\n", | |
363 | (int)len, (int)st.st_size)); | |
364 | } | |
365 | return TDB_ERRCODE(TDB_ERR_IO, -1); | |
366 | } | |
367 | ||
368 | /* Unmap, update size, remap */ | |
369 | if (tdb_munmap(tdb) == -1) | |
370 | return TDB_ERRCODE(TDB_ERR_IO, -1); | |
371 | tdb->map_size = st.st_size; | |
372 | tdb_mmap(tdb); | |
373 | return 0; | |
374 | } | |
375 | ||
376 | /* write a lump of data at a specified offset */ | |
377 | static int tdb_write(TDB_CONTEXT *tdb, tdb_off off, void *buf, tdb_len len) | |
378 | { | |
379 | if (tdb_oob(tdb, off + len, 0) != 0) | |
380 | return -1; | |
381 | ||
382 | if (tdb->map_ptr) | |
383 | memcpy(off + (char *)tdb->map_ptr, buf, len); | |
384 | #ifdef HAVE_PWRITE | |
385 | else if (pwrite(tdb->fd, buf, len, off) != (ssize_t)len) { | |
386 | #else | |
387 | else if (lseek(tdb->fd, off, SEEK_SET) != off | |
388 | || write(tdb->fd, buf, len) != (ssize_t)len) { | |
389 | #endif | |
390 | /* Ensure ecode is set for log fn. */ | |
391 | tdb->ecode = TDB_ERR_IO; | |
392 | TDB_LOG((tdb, 0,"tdb_write failed at %d len=%d (%s)\n", | |
393 | off, len, strerror(errno))); | |
394 | return TDB_ERRCODE(TDB_ERR_IO, -1); | |
395 | } | |
396 | return 0; | |
397 | } | |
398 | ||
399 | /* read a lump of data at a specified offset, maybe convert */ | |
400 | static int tdb_read(TDB_CONTEXT *tdb,tdb_off off,void *buf,tdb_len len,int cv) | |
401 | { | |
402 | if (tdb_oob(tdb, off + len, 0) != 0) | |
403 | return -1; | |
404 | ||
405 | if (tdb->map_ptr) | |
406 | memcpy(buf, off + (char *)tdb->map_ptr, len); | |
407 | #ifdef HAVE_PREAD | |
408 | else if (pread(tdb->fd, buf, len, off) != (ssize_t)len) { | |
409 | #else | |
410 | else if (lseek(tdb->fd, off, SEEK_SET) != off | |
411 | || read(tdb->fd, buf, len) != (ssize_t)len) { | |
412 | #endif | |
413 | /* Ensure ecode is set for log fn. */ | |
414 | tdb->ecode = TDB_ERR_IO; | |
415 | TDB_LOG((tdb, 0,"tdb_read failed at %d len=%d (%s)\n", | |
416 | off, len, strerror(errno))); | |
417 | return TDB_ERRCODE(TDB_ERR_IO, -1); | |
418 | } | |
419 | if (cv) | |
420 | convert(buf, len); | |
421 | return 0; | |
422 | } | |
423 | ||
424 | /* read a lump of data, allocating the space for it */ | |
425 | static char *tdb_alloc_read(TDB_CONTEXT *tdb, tdb_off offset, tdb_len len) | |
426 | { | |
427 | char *buf; | |
428 | ||
429 | if (!(buf = malloc(len))) { | |
430 | /* Ensure ecode is set for log fn. */ | |
431 | tdb->ecode = TDB_ERR_OOM; | |
432 | TDB_LOG((tdb, 0,"tdb_alloc_read malloc failed len=%d (%s)\n", | |
433 | len, strerror(errno))); | |
434 | return TDB_ERRCODE(TDB_ERR_OOM, buf); | |
435 | } | |
436 | if (tdb_read(tdb, offset, buf, len, 0) == -1) { | |
437 | SAFE_FREE(buf); | |
438 | return NULL; | |
439 | } | |
440 | return buf; | |
441 | } | |
442 | ||
443 | /* read/write a tdb_off */ | |
444 | static int ofs_read(TDB_CONTEXT *tdb, tdb_off offset, tdb_off *d) | |
445 | { | |
446 | return tdb_read(tdb, offset, (char*)d, sizeof(*d), DOCONV()); | |
447 | } | |
448 | static int ofs_write(TDB_CONTEXT *tdb, tdb_off offset, tdb_off *d) | |
449 | { | |
450 | tdb_off off = *d; | |
451 | return tdb_write(tdb, offset, CONVERT(off), sizeof(*d)); | |
452 | } | |
453 | ||
454 | /* read/write a record */ | |
455 | static int rec_read(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec) | |
456 | { | |
457 | if (tdb_read(tdb, offset, rec, sizeof(*rec),DOCONV()) == -1) | |
458 | return -1; | |
459 | if (TDB_BAD_MAGIC(rec)) { | |
460 | /* Ensure ecode is set for log fn. */ | |
461 | tdb->ecode = TDB_ERR_CORRUPT; | |
462 | TDB_LOG((tdb, 0,"rec_read bad magic 0x%x at offset=%d\n", rec->magic, offset)); | |
463 | return TDB_ERRCODE(TDB_ERR_CORRUPT, -1); | |
464 | } | |
465 | return tdb_oob(tdb, rec->next+sizeof(*rec), 0); | |
466 | } | |
467 | static int rec_write(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec) | |
468 | { | |
469 | struct list_struct r = *rec; | |
470 | return tdb_write(tdb, offset, CONVERT(r), sizeof(r)); | |
471 | } | |
472 | ||
473 | /* read a freelist record and check for simple errors */ | |
474 | static int rec_free_read(TDB_CONTEXT *tdb, tdb_off off, struct list_struct *rec) | |
475 | { | |
476 | if (tdb_read(tdb, off, rec, sizeof(*rec),DOCONV()) == -1) | |
477 | return -1; | |
478 | ||
479 | if (rec->magic == TDB_MAGIC) { | |
480 | /* this happens when a app is showdown while deleting a record - we should | |
481 | not completely fail when this happens */ | |
482 | TDB_LOG((tdb, 0,"rec_free_read non-free magic at offset=%d - fixing\n", | |
483 | rec->magic, off)); | |
484 | rec->magic = TDB_FREE_MAGIC; | |
485 | if (tdb_write(tdb, off, rec, sizeof(*rec)) == -1) | |
486 | return -1; | |
487 | } | |
488 | ||
489 | if (rec->magic != TDB_FREE_MAGIC) { | |
490 | /* Ensure ecode is set for log fn. */ | |
491 | tdb->ecode = TDB_ERR_CORRUPT; | |
492 | TDB_LOG((tdb, 0,"rec_free_read bad magic 0x%x at offset=%d\n", | |
493 | rec->magic, off)); | |
494 | return TDB_ERRCODE(TDB_ERR_CORRUPT, -1); | |
495 | } | |
496 | if (tdb_oob(tdb, rec->next+sizeof(*rec), 0) != 0) | |
497 | return -1; | |
498 | return 0; | |
499 | } | |
500 | ||
501 | /* update a record tailer (must hold allocation lock) */ | |
502 | static int update_tailer(TDB_CONTEXT *tdb, tdb_off offset, | |
503 | const struct list_struct *rec) | |
504 | { | |
505 | tdb_off totalsize; | |
506 | ||
507 | /* Offset of tailer from record header */ | |
508 | totalsize = sizeof(*rec) + rec->rec_len; | |
509 | return ofs_write(tdb, offset + totalsize - sizeof(tdb_off), | |
510 | &totalsize); | |
511 | } | |
512 | ||
513 | static tdb_off tdb_dump_record(TDB_CONTEXT *tdb, tdb_off offset) | |
514 | { | |
515 | struct list_struct rec; | |
516 | tdb_off tailer_ofs, tailer; | |
517 | ||
518 | if (tdb_read(tdb, offset, (char *)&rec, sizeof(rec), DOCONV()) == -1) { | |
519 | printf("ERROR: failed to read record at %u\n", offset); | |
520 | return 0; | |
521 | } | |
522 | ||
523 | printf(" rec: offset=%u next=%d rec_len=%d key_len=%d data_len=%d full_hash=0x%x magic=0x%x\n", | |
524 | offset, rec.next, rec.rec_len, rec.key_len, rec.data_len, rec.full_hash, rec.magic); | |
525 | ||
526 | tailer_ofs = offset + sizeof(rec) + rec.rec_len - sizeof(tdb_off); | |
527 | if (ofs_read(tdb, tailer_ofs, &tailer) == -1) { | |
528 | printf("ERROR: failed to read tailer at %u\n", tailer_ofs); | |
529 | return rec.next; | |
530 | } | |
531 | ||
532 | if (tailer != rec.rec_len + sizeof(rec)) { | |
533 | printf("ERROR: tailer does not match record! tailer=%u totalsize=%u\n", | |
534 | (unsigned)tailer, (unsigned)(rec.rec_len + sizeof(rec))); | |
535 | } | |
536 | return rec.next; | |
537 | } | |
538 | ||
539 | static int tdb_dump_chain(TDB_CONTEXT *tdb, int i) | |
540 | { | |
541 | tdb_off rec_ptr, top; | |
542 | ||
543 | top = TDB_HASH_TOP(i); | |
544 | ||
545 | if (tdb_lock(tdb, i, F_WRLCK) != 0) | |
546 | return -1; | |
547 | ||
548 | if (ofs_read(tdb, top, &rec_ptr) == -1) | |
549 | return tdb_unlock(tdb, i, F_WRLCK); | |
550 | ||
551 | if (rec_ptr) | |
552 | printf("hash=%d\n", i); | |
553 | ||
554 | while (rec_ptr) { | |
555 | rec_ptr = tdb_dump_record(tdb, rec_ptr); | |
556 | } | |
557 | ||
558 | return tdb_unlock(tdb, i, F_WRLCK); | |
559 | } | |
560 | ||
561 | void tdb_dump_all(TDB_CONTEXT *tdb) | |
562 | { | |
563 | int i; | |
564 | for (i=0;i<tdb->header.hash_size;i++) { | |
565 | tdb_dump_chain(tdb, i); | |
566 | } | |
567 | printf("freelist:\n"); | |
568 | tdb_dump_chain(tdb, -1); | |
569 | } | |
570 | ||
571 | int tdb_printfreelist(TDB_CONTEXT *tdb) | |
572 | { | |
573 | int ret; | |
574 | long total_free = 0; | |
575 | tdb_off offset, rec_ptr; | |
576 | struct list_struct rec; | |
577 | ||
578 | if ((ret = tdb_lock(tdb, -1, F_WRLCK)) != 0) | |
579 | return ret; | |
580 | ||
581 | offset = FREELIST_TOP; | |
582 | ||
583 | /* read in the freelist top */ | |
584 | if (ofs_read(tdb, offset, &rec_ptr) == -1) { | |
585 | tdb_unlock(tdb, -1, F_WRLCK); | |
586 | return 0; | |
587 | } | |
588 | ||
589 | printf("freelist top=[0x%08x]\n", rec_ptr ); | |
590 | while (rec_ptr) { | |
591 | if (tdb_read(tdb, rec_ptr, (char *)&rec, sizeof(rec), DOCONV()) == -1) { | |
592 | tdb_unlock(tdb, -1, F_WRLCK); | |
593 | return -1; | |
594 | } | |
595 | ||
596 | if (rec.magic != TDB_FREE_MAGIC) { | |
597 | printf("bad magic 0x%08x in free list\n", rec.magic); | |
598 | tdb_unlock(tdb, -1, F_WRLCK); | |
599 | return -1; | |
600 | } | |
601 | ||
602 | printf("entry offset=[0x%08x], rec.rec_len = [0x%08x (%d)]\n", rec.next, rec.rec_len, rec.rec_len ); | |
603 | total_free += rec.rec_len; | |
604 | ||
605 | /* move to the next record */ | |
606 | rec_ptr = rec.next; | |
607 | } | |
608 | printf("total rec_len = [0x%08x (%d)]\n", (int)total_free, | |
609 | (int)total_free); | |
610 | ||
611 | return tdb_unlock(tdb, -1, F_WRLCK); | |
612 | } | |
613 | ||
614 | /* Remove an element from the freelist. Must have alloc lock. */ | |
615 | static int remove_from_freelist(TDB_CONTEXT *tdb, tdb_off off, tdb_off next) | |
616 | { | |
617 | tdb_off last_ptr, i; | |
618 | ||
619 | /* read in the freelist top */ | |
620 | last_ptr = FREELIST_TOP; | |
621 | while (ofs_read(tdb, last_ptr, &i) != -1 && i != 0) { | |
622 | if (i == off) { | |
623 | /* We've found it! */ | |
624 | return ofs_write(tdb, last_ptr, &next); | |
625 | } | |
626 | /* Follow chain (next offset is at start of record) */ | |
627 | last_ptr = i; | |
628 | } | |
629 | TDB_LOG((tdb, 0,"remove_from_freelist: not on list at off=%d\n", off)); | |
630 | return TDB_ERRCODE(TDB_ERR_CORRUPT, -1); | |
631 | } | |
632 | ||
633 | /* Add an element into the freelist. Merge adjacent records if | |
634 | neccessary. */ | |
635 | static int tdb_free(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec) | |
636 | { | |
637 | tdb_off right, left; | |
638 | ||
639 | /* Allocation and tailer lock */ | |
640 | if (tdb_lock(tdb, -1, F_WRLCK) != 0) | |
641 | return -1; | |
642 | ||
643 | /* set an initial tailer, so if we fail we don't leave a bogus record */ | |
644 | if (update_tailer(tdb, offset, rec) != 0) { | |
645 | TDB_LOG((tdb, 0, "tdb_free: upfate_tailer failed!\n")); | |
646 | goto fail; | |
647 | } | |
648 | ||
649 | /* Look right first (I'm an Australian, dammit) */ | |
650 | right = offset + sizeof(*rec) + rec->rec_len; | |
651 | if (right + sizeof(*rec) <= tdb->map_size) { | |
652 | struct list_struct r; | |
653 | ||
654 | if (tdb_read(tdb, right, &r, sizeof(r), DOCONV()) == -1) { | |
655 | TDB_LOG((tdb, 0, "tdb_free: right read failed at %u\n", right)); | |
656 | goto left; | |
657 | } | |
658 | ||
659 | /* If it's free, expand to include it. */ | |
660 | if (r.magic == TDB_FREE_MAGIC) { | |
661 | if (remove_from_freelist(tdb, right, r.next) == -1) { | |
662 | TDB_LOG((tdb, 0, "tdb_free: right free failed at %u\n", right)); | |
663 | goto left; | |
664 | } | |
665 | rec->rec_len += sizeof(r) + r.rec_len; | |
666 | } | |
667 | } | |
668 | ||
669 | left: | |
670 | /* Look left */ | |
671 | left = offset - sizeof(tdb_off); | |
672 | if (left > TDB_HASH_TOP(tdb->header.hash_size-1)) { | |
673 | struct list_struct l; | |
674 | tdb_off leftsize; | |
675 | ||
676 | /* Read in tailer and jump back to header */ | |
677 | if (ofs_read(tdb, left, &leftsize) == -1) { | |
678 | TDB_LOG((tdb, 0, "tdb_free: left offset read failed at %u\n", left)); | |
679 | goto update; | |
680 | } | |
681 | left = offset - leftsize; | |
682 | ||
683 | /* Now read in record */ | |
684 | if (tdb_read(tdb, left, &l, sizeof(l), DOCONV()) == -1) { | |
685 | TDB_LOG((tdb, 0, "tdb_free: left read failed at %u (%u)\n", left, leftsize)); | |
686 | goto update; | |
687 | } | |
688 | ||
689 | /* If it's free, expand to include it. */ | |
690 | if (l.magic == TDB_FREE_MAGIC) { | |
691 | if (remove_from_freelist(tdb, left, l.next) == -1) { | |
692 | TDB_LOG((tdb, 0, "tdb_free: left free failed at %u\n", left)); | |
693 | goto update; | |
694 | } else { | |
695 | offset = left; | |
696 | rec->rec_len += leftsize; | |
697 | } | |
698 | } | |
699 | } | |
700 | ||
701 | update: | |
702 | if (update_tailer(tdb, offset, rec) == -1) { | |
703 | TDB_LOG((tdb, 0, "tdb_free: update_tailer failed at %u\n", offset)); | |
704 | goto fail; | |
705 | } | |
706 | ||
707 | /* Now, prepend to free list */ | |
708 | rec->magic = TDB_FREE_MAGIC; | |
709 | ||
710 | if (ofs_read(tdb, FREELIST_TOP, &rec->next) == -1 || | |
711 | rec_write(tdb, offset, rec) == -1 || | |
712 | ofs_write(tdb, FREELIST_TOP, &offset) == -1) { | |
713 | TDB_LOG((tdb, 0, "tdb_free record write failed at offset=%d\n", offset)); | |
714 | goto fail; | |
715 | } | |
716 | ||
717 | /* And we're done. */ | |
718 | tdb_unlock(tdb, -1, F_WRLCK); | |
719 | return 0; | |
720 | ||
721 | fail: | |
722 | tdb_unlock(tdb, -1, F_WRLCK); | |
723 | return -1; | |
724 | } | |
725 | ||
726 | ||
727 | /* expand a file. we prefer to use ftruncate, as that is what posix | |
728 | says to use for mmap expansion */ | |
729 | static int expand_file(TDB_CONTEXT *tdb, tdb_off size, tdb_off addition) | |
730 | { | |
731 | char buf[1024]; | |
732 | #if HAVE_FTRUNCATE_EXTEND | |
733 | if (ftruncate(tdb->fd, size+addition) != 0) { | |
734 | TDB_LOG((tdb, 0, "expand_file ftruncate to %d failed (%s)\n", | |
735 | size+addition, strerror(errno))); | |
736 | return -1; | |
737 | } | |
738 | #else | |
739 | char b = 0; | |
740 | ||
741 | #ifdef HAVE_PWRITE | |
742 | if (pwrite(tdb->fd, &b, 1, (size+addition) - 1) != 1) { | |
743 | #else | |
744 | if (lseek(tdb->fd, (size+addition) - 1, SEEK_SET) != (size+addition) - 1 || | |
745 | write(tdb->fd, &b, 1) != 1) { | |
746 | #endif | |
747 | TDB_LOG((tdb, 0, "expand_file to %d failed (%s)\n", | |
748 | size+addition, strerror(errno))); | |
749 | return -1; | |
750 | } | |
751 | #endif | |
752 | ||
753 | /* now fill the file with something. This ensures that the file isn't sparse, which would be | |
754 | very bad if we ran out of disk. This must be done with write, not via mmap */ | |
755 | memset(buf, 0x42, sizeof(buf)); | |
756 | while (addition) { | |
757 | int n = addition>sizeof(buf)?sizeof(buf):addition; | |
758 | #ifdef HAVE_PWRITE | |
759 | int ret = pwrite(tdb->fd, buf, n, size); | |
760 | #else | |
761 | int ret; | |
762 | if (lseek(tdb->fd, size, SEEK_SET) != size) | |
763 | return -1; | |
764 | ret = write(tdb->fd, buf, n); | |
765 | #endif | |
766 | if (ret != n) { | |
767 | TDB_LOG((tdb, 0, "expand_file write of %d failed (%s)\n", | |
768 | n, strerror(errno))); | |
769 | return -1; | |
770 | } | |
771 | addition -= n; | |
772 | size += n; | |
773 | } | |
774 | return 0; | |
775 | } | |
776 | ||
777 | ||
778 | /* expand the database at least size bytes by expanding the underlying | |
779 | file and doing the mmap again if necessary */ | |
780 | static int tdb_expand(TDB_CONTEXT *tdb, tdb_off size) | |
781 | { | |
782 | struct list_struct rec; | |
783 | tdb_off offset; | |
784 | ||
785 | if (tdb_lock(tdb, -1, F_WRLCK) == -1) { | |
786 | TDB_LOG((tdb, 0, "lock failed in tdb_expand\n")); | |
787 | return -1; | |
788 | } | |
789 | ||
790 | /* must know about any previous expansions by another process */ | |
791 | tdb_oob(tdb, tdb->map_size + 1, 1); | |
792 | ||
793 | /* always make room for at least 10 more records, and round | |
794 | the database up to a multiple of TDB_PAGE_SIZE */ | |
795 | size = TDB_ALIGN(tdb->map_size + size*10, TDB_PAGE_SIZE) - tdb->map_size; | |
796 | ||
797 | if (!(tdb->flags & TDB_INTERNAL)) | |
798 | tdb_munmap(tdb); | |
799 | ||
800 | /* | |
801 | * We must ensure the file is unmapped before doing this | |
802 | * to ensure consistency with systems like OpenBSD where | |
803 | * writes and mmaps are not consistent. | |
804 | */ | |
805 | ||
806 | /* expand the file itself */ | |
807 | if (!(tdb->flags & TDB_INTERNAL)) { | |
808 | if (expand_file(tdb, tdb->map_size, size) != 0) | |
809 | goto fail; | |
810 | } | |
811 | ||
812 | tdb->map_size += size; | |
813 | ||
814 | if (tdb->flags & TDB_INTERNAL) | |
815 | tdb->map_ptr = realloc(tdb->map_ptr, tdb->map_size); | |
816 | else { | |
817 | /* | |
818 | * We must ensure the file is remapped before adding the space | |
819 | * to ensure consistency with systems like OpenBSD where | |
820 | * writes and mmaps are not consistent. | |
821 | */ | |
822 | ||
823 | /* We're ok if the mmap fails as we'll fallback to read/write */ | |
824 | tdb_mmap(tdb); | |
825 | } | |
826 | ||
827 | /* form a new freelist record */ | |
828 | memset(&rec,'\0',sizeof(rec)); | |
829 | rec.rec_len = size - sizeof(rec); | |
830 | ||
831 | /* link it into the free list */ | |
832 | offset = tdb->map_size - size; | |
833 | if (tdb_free(tdb, offset, &rec) == -1) | |
834 | goto fail; | |
835 | ||
836 | tdb_unlock(tdb, -1, F_WRLCK); | |
837 | return 0; | |
838 | fail: | |
839 | tdb_unlock(tdb, -1, F_WRLCK); | |
840 | return -1; | |
841 | } | |
842 | ||
843 | /* allocate some space from the free list. The offset returned points | |
844 | to a unconnected list_struct within the database with room for at | |
845 | least length bytes of total data | |
846 | ||
847 | 0 is returned if the space could not be allocated | |
848 | */ | |
849 | static tdb_off tdb_allocate(TDB_CONTEXT *tdb, tdb_len length, | |
850 | struct list_struct *rec) | |
851 | { | |
852 | tdb_off rec_ptr, last_ptr, newrec_ptr; | |
853 | struct list_struct newrec; | |
854 | ||
855 | if (tdb_lock(tdb, -1, F_WRLCK) == -1) | |
856 | return 0; | |
857 | ||
858 | /* Extra bytes required for tailer */ | |
859 | length += sizeof(tdb_off); | |
860 | ||
861 | again: | |
862 | last_ptr = FREELIST_TOP; | |
863 | ||
864 | /* read in the freelist top */ | |
865 | if (ofs_read(tdb, FREELIST_TOP, &rec_ptr) == -1) | |
866 | goto fail; | |
867 | ||
868 | /* keep looking until we find a freelist record big enough */ | |
869 | while (rec_ptr) { | |
870 | if (rec_free_read(tdb, rec_ptr, rec) == -1) | |
871 | goto fail; | |
872 | ||
873 | if (rec->rec_len >= length) { | |
874 | /* found it - now possibly split it up */ | |
875 | if (rec->rec_len > length + MIN_REC_SIZE) { | |
876 | /* Length of left piece */ | |
877 | length = TDB_ALIGN(length, TDB_ALIGNMENT); | |
878 | ||
879 | /* Right piece to go on free list */ | |
880 | newrec.rec_len = rec->rec_len | |
881 | - (sizeof(*rec) + length); | |
882 | newrec_ptr = rec_ptr + sizeof(*rec) + length; | |
883 | ||
884 | /* And left record is shortened */ | |
885 | rec->rec_len = length; | |
886 | } else | |
887 | newrec_ptr = 0; | |
888 | ||
889 | /* Remove allocated record from the free list */ | |
890 | if (ofs_write(tdb, last_ptr, &rec->next) == -1) | |
891 | goto fail; | |
892 | ||
893 | /* Update header: do this before we drop alloc | |
894 | lock, otherwise tdb_free() might try to | |
895 | merge with us, thinking we're free. | |
896 | (Thanks Jeremy Allison). */ | |
897 | rec->magic = TDB_MAGIC; | |
898 | if (rec_write(tdb, rec_ptr, rec) == -1) | |
899 | goto fail; | |
900 | ||
901 | /* Did we create new block? */ | |
902 | if (newrec_ptr) { | |
903 | /* Update allocated record tailer (we | |
904 | shortened it). */ | |
905 | if (update_tailer(tdb, rec_ptr, rec) == -1) | |
906 | goto fail; | |
907 | ||
908 | /* Free new record */ | |
909 | if (tdb_free(tdb, newrec_ptr, &newrec) == -1) | |
910 | goto fail; | |
911 | } | |
912 | ||
913 | /* all done - return the new record offset */ | |
914 | tdb_unlock(tdb, -1, F_WRLCK); | |
915 | return rec_ptr; | |
916 | } | |
917 | /* move to the next record */ | |
918 | last_ptr = rec_ptr; | |
919 | rec_ptr = rec->next; | |
920 | } | |
921 | /* we didn't find enough space. See if we can expand the | |
922 | database and if we can then try again */ | |
923 | if (tdb_expand(tdb, length + sizeof(*rec)) == 0) | |
924 | goto again; | |
925 | fail: | |
926 | tdb_unlock(tdb, -1, F_WRLCK); | |
927 | return 0; | |
928 | } | |
929 | ||
930 | /* initialise a new database with a specified hash size */ | |
931 | static int tdb_new_database(TDB_CONTEXT *tdb, int hash_size) | |
932 | { | |
933 | struct tdb_header *newdb; | |
934 | int size, ret = -1; | |
935 | ||
936 | /* We make it up in memory, then write it out if not internal */ | |
937 | size = sizeof(struct tdb_header) + (hash_size+1)*sizeof(tdb_off); | |
938 | if (!(newdb = calloc(size, 1))) | |
939 | return TDB_ERRCODE(TDB_ERR_OOM, -1); | |
940 | ||
941 | /* Fill in the header */ | |
942 | newdb->version = TDB_VERSION; | |
943 | newdb->hash_size = hash_size; | |
944 | #ifdef USE_SPINLOCKS | |
945 | newdb->rwlocks = size; | |
946 | #endif | |
947 | if (tdb->flags & TDB_INTERNAL) { | |
948 | tdb->map_size = size; | |
949 | tdb->map_ptr = (char *)newdb; | |
950 | memcpy(&tdb->header, newdb, sizeof(tdb->header)); | |
951 | /* Convert the `ondisk' version if asked. */ | |
952 | CONVERT(*newdb); | |
953 | return 0; | |
954 | } | |
955 | if (lseek(tdb->fd, 0, SEEK_SET) == -1) | |
956 | goto fail; | |
957 | ||
958 | if (ftruncate(tdb->fd, 0) == -1) | |
959 | goto fail; | |
960 | ||
961 | /* This creates an endian-converted header, as if read from disk */ | |
962 | CONVERT(*newdb); | |
963 | memcpy(&tdb->header, newdb, sizeof(tdb->header)); | |
964 | /* Don't endian-convert the magic food! */ | |
965 | memcpy(newdb->magic_food, TDB_MAGIC_FOOD, strlen(TDB_MAGIC_FOOD)+1); | |
966 | if (write(tdb->fd, newdb, size) != size) | |
967 | ret = -1; | |
968 | else | |
969 | ret = tdb_create_rwlocks(tdb->fd, hash_size); | |
970 | ||
971 | fail: | |
972 | SAFE_FREE(newdb); | |
973 | return ret; | |
974 | } | |
975 | ||
976 | /* Returns 0 on fail. On success, return offset of record, and fills | |
977 | in rec */ | |
978 | static tdb_off tdb_find(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash, | |
979 | struct list_struct *r) | |
980 | { | |
981 | tdb_off rec_ptr; | |
982 | ||
983 | /* read in the hash top */ | |
984 | if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) | |
985 | return 0; | |
986 | ||
987 | /* keep looking until we find the right record */ | |
988 | while (rec_ptr) { | |
989 | if (rec_read(tdb, rec_ptr, r) == -1) | |
990 | return 0; | |
991 | ||
992 | if (!TDB_DEAD(r) && hash==r->full_hash && key.dsize==r->key_len) { | |
993 | char *k; | |
994 | /* a very likely hit - read the key */ | |
995 | k = tdb_alloc_read(tdb, rec_ptr + sizeof(*r), | |
996 | r->key_len); | |
997 | if (!k) | |
998 | return 0; | |
999 | ||
1000 | if (memcmp(key.dptr, k, key.dsize) == 0) { | |
1001 | SAFE_FREE(k); | |
1002 | return rec_ptr; | |
1003 | } | |
1004 | SAFE_FREE(k); | |
1005 | } | |
1006 | rec_ptr = r->next; | |
1007 | } | |
1008 | return TDB_ERRCODE(TDB_ERR_NOEXIST, 0); | |
1009 | } | |
1010 | ||
1011 | /* If they do lockkeys, check that this hash is one they locked */ | |
1012 | static int tdb_keylocked(TDB_CONTEXT *tdb, u32 hash) | |
1013 | { | |
1014 | u32 i; | |
1015 | if (!tdb->lockedkeys) | |
1016 | return 1; | |
1017 | for (i = 0; i < tdb->lockedkeys[0]; i++) | |
1018 | if (tdb->lockedkeys[i+1] == hash) | |
1019 | return 1; | |
1020 | return TDB_ERRCODE(TDB_ERR_NOLOCK, 0); | |
1021 | } | |
1022 | ||
1023 | /* As tdb_find, but if you succeed, keep the lock */ | |
1024 | static tdb_off tdb_find_lock(TDB_CONTEXT *tdb, TDB_DATA key, int locktype, | |
1025 | struct list_struct *rec) | |
1026 | { | |
1027 | u32 hash, rec_ptr; | |
1028 | ||
1029 | hash = tdb_hash(&key); | |
1030 | if (!tdb_keylocked(tdb, hash)) | |
1031 | return 0; | |
1032 | if (tdb_lock(tdb, BUCKET(hash), locktype) == -1) | |
1033 | return 0; | |
1034 | if (!(rec_ptr = tdb_find(tdb, key, hash, rec))) | |
1035 | tdb_unlock(tdb, BUCKET(hash), locktype); | |
1036 | return rec_ptr; | |
1037 | } | |
1038 | ||
1039 | enum TDB_ERROR tdb_error(TDB_CONTEXT *tdb) | |
1040 | { | |
1041 | return tdb->ecode; | |
1042 | } | |
1043 | ||
1044 | static struct tdb_errname { | |
1045 | enum TDB_ERROR ecode; const char *estring; | |
1046 | } emap[] = { {TDB_SUCCESS, "Success"}, | |
1047 | {TDB_ERR_CORRUPT, "Corrupt database"}, | |
1048 | {TDB_ERR_IO, "IO Error"}, | |
1049 | {TDB_ERR_LOCK, "Locking error"}, | |
1050 | {TDB_ERR_OOM, "Out of memory"}, | |
1051 | {TDB_ERR_EXISTS, "Record exists"}, | |
1052 | {TDB_ERR_NOLOCK, "Lock exists on other keys"}, | |
1053 | {TDB_ERR_NOEXIST, "Record does not exist"} }; | |
1054 | ||
1055 | /* Error string for the last tdb error */ | |
1056 | const char *tdb_errorstr(TDB_CONTEXT *tdb) | |
1057 | { | |
1058 | u32 i; | |
1059 | for (i = 0; i < sizeof(emap) / sizeof(struct tdb_errname); i++) | |
1060 | if (tdb->ecode == emap[i].ecode) | |
1061 | return emap[i].estring; | |
1062 | return "Invalid error code"; | |
1063 | } | |
1064 | ||
1065 | /* update an entry in place - this only works if the new data size | |
1066 | is <= the old data size and the key exists. | |
1067 | on failure return -1. | |
1068 | */ | |
1069 | ||
1070 | static int tdb_update(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf) | |
1071 | { | |
1072 | struct list_struct rec; | |
1073 | tdb_off rec_ptr; | |
1074 | ||
1075 | /* find entry */ | |
1076 | if (!(rec_ptr = tdb_find(tdb, key, tdb_hash(&key), &rec))) | |
1077 | return -1; | |
1078 | ||
1079 | /* must be long enough key, data and tailer */ | |
1080 | if (rec.rec_len < key.dsize + dbuf.dsize + sizeof(tdb_off)) { | |
1081 | tdb->ecode = TDB_SUCCESS; /* Not really an error */ | |
1082 | return -1; | |
1083 | } | |
1084 | ||
1085 | if (tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len, | |
1086 | dbuf.dptr, dbuf.dsize) == -1) | |
1087 | return -1; | |
1088 | ||
1089 | if (dbuf.dsize != rec.data_len) { | |
1090 | /* update size */ | |
1091 | rec.data_len = dbuf.dsize; | |
1092 | return rec_write(tdb, rec_ptr, &rec); | |
1093 | } | |
1094 | ||
1095 | return 0; | |
1096 | } | |
1097 | ||
1098 | /* find an entry in the database given a key */ | |
1099 | /* If an entry doesn't exist tdb_err will be set to | |
1100 | * TDB_ERR_NOEXIST. If a key has no data attached | |
1101 | * tdb_err will not be set. Both will return a | |
1102 | * zero pptr and zero dsize. | |
1103 | */ | |
1104 | ||
1105 | TDB_DATA tdb_fetch(TDB_CONTEXT *tdb, TDB_DATA key) | |
1106 | { | |
1107 | tdb_off rec_ptr; | |
1108 | struct list_struct rec; | |
1109 | TDB_DATA ret; | |
1110 | ||
1111 | /* find which hash bucket it is in */ | |
1112 | if (!(rec_ptr = tdb_find_lock(tdb,key,F_RDLCK,&rec))) | |
1113 | return tdb_null; | |
1114 | ||
1115 | if (rec.data_len) | |
1116 | ret.dptr = tdb_alloc_read(tdb, rec_ptr + sizeof(rec) + rec.key_len, | |
1117 | rec.data_len); | |
1118 | else | |
1119 | ret.dptr = NULL; | |
1120 | ret.dsize = rec.data_len; | |
1121 | tdb_unlock(tdb, BUCKET(rec.full_hash), F_RDLCK); | |
1122 | return ret; | |
1123 | } | |
1124 | ||
1125 | /* check if an entry in the database exists | |
1126 | ||
1127 | note that 1 is returned if the key is found and 0 is returned if not found | |
1128 | this doesn't match the conventions in the rest of this module, but is | |
1129 | compatible with gdbm | |
1130 | */ | |
1131 | int tdb_exists(TDB_CONTEXT *tdb, TDB_DATA key) | |
1132 | { | |
1133 | struct list_struct rec; | |
1134 | ||
1135 | if (tdb_find_lock(tdb, key, F_RDLCK, &rec) == 0) | |
1136 | return 0; | |
1137 | tdb_unlock(tdb, BUCKET(rec.full_hash), F_RDLCK); | |
1138 | return 1; | |
1139 | } | |
1140 | ||
1141 | /* record lock stops delete underneath */ | |
1142 | static int lock_record(TDB_CONTEXT *tdb, tdb_off off) | |
1143 | { | |
1144 | return off ? tdb_brlock(tdb, off, F_RDLCK, F_SETLKW, 0) : 0; | |
1145 | } | |
1146 | /* | |
1147 | Write locks override our own fcntl readlocks, so check it here. | |
1148 | Note this is meant to be F_SETLK, *not* F_SETLKW, as it's not | |
1149 | an error to fail to get the lock here. | |
1150 | */ | |
1151 | ||
1152 | static int write_lock_record(TDB_CONTEXT *tdb, tdb_off off) | |
1153 | { | |
1154 | struct tdb_traverse_lock *i; | |
1155 | for (i = &tdb->travlocks; i; i = i->next) | |
1156 | if (i->off == off) | |
1157 | return -1; | |
1158 | return tdb_brlock(tdb, off, F_WRLCK, F_SETLK, 1); | |
1159 | } | |
1160 | ||
1161 | /* | |
1162 | Note this is meant to be F_SETLK, *not* F_SETLKW, as it's not | |
1163 | an error to fail to get the lock here. | |
1164 | */ | |
1165 | ||
1166 | static int write_unlock_record(TDB_CONTEXT *tdb, tdb_off off) | |
1167 | { | |
1168 | return tdb_brlock(tdb, off, F_UNLCK, F_SETLK, 0); | |
1169 | } | |
1170 | /* fcntl locks don't stack: avoid unlocking someone else's */ | |
1171 | static int unlock_record(TDB_CONTEXT *tdb, tdb_off off) | |
1172 | { | |
1173 | struct tdb_traverse_lock *i; | |
1174 | u32 count = 0; | |
1175 | ||
1176 | if (off == 0) | |
1177 | return 0; | |
1178 | for (i = &tdb->travlocks; i; i = i->next) | |
1179 | if (i->off == off) | |
1180 | count++; | |
1181 | return (count == 1 ? tdb_brlock(tdb, off, F_UNLCK, F_SETLKW, 0) : 0); | |
1182 | } | |
1183 | ||
1184 | /* actually delete an entry in the database given the offset */ | |
1185 | static int do_delete(TDB_CONTEXT *tdb, tdb_off rec_ptr, struct list_struct*rec) | |
1186 | { | |
1187 | tdb_off last_ptr, i; | |
1188 | struct list_struct lastrec; | |
1189 | ||
1190 | if (tdb->read_only) return -1; | |
1191 | ||
1192 | if (write_lock_record(tdb, rec_ptr) == -1) { | |
1193 | /* Someone traversing here: mark it as dead */ | |
1194 | rec->magic = TDB_DEAD_MAGIC; | |
1195 | return rec_write(tdb, rec_ptr, rec); | |
1196 | } | |
1197 | if (write_unlock_record(tdb, rec_ptr) != 0) | |
1198 | return -1; | |
1199 | ||
1200 | /* find previous record in hash chain */ | |
1201 | if (ofs_read(tdb, TDB_HASH_TOP(rec->full_hash), &i) == -1) | |
1202 | return -1; | |
1203 | for (last_ptr = 0; i != rec_ptr; last_ptr = i, i = lastrec.next) | |
1204 | if (rec_read(tdb, i, &lastrec) == -1) | |
1205 | return -1; | |
1206 | ||
1207 | /* unlink it: next ptr is at start of record. */ | |
1208 | if (last_ptr == 0) | |
1209 | last_ptr = TDB_HASH_TOP(rec->full_hash); | |
1210 | if (ofs_write(tdb, last_ptr, &rec->next) == -1) | |
1211 | return -1; | |
1212 | ||
1213 | /* recover the space */ | |
1214 | if (tdb_free(tdb, rec_ptr, rec) == -1) | |
1215 | return -1; | |
1216 | return 0; | |
1217 | } | |
1218 | ||
1219 | /* Uses traverse lock: 0 = finish, -1 = error, other = record offset */ | |
1220 | static int tdb_next_lock(TDB_CONTEXT *tdb, struct tdb_traverse_lock *tlock, | |
1221 | struct list_struct *rec) | |
1222 | { | |
1223 | int want_next = (tlock->off != 0); | |
1224 | ||
1225 | /* No traversal allows if you've called tdb_lockkeys() */ | |
1226 | if (tdb->lockedkeys) | |
1227 | return TDB_ERRCODE(TDB_ERR_NOLOCK, -1); | |
1228 | ||
1229 | /* Lock each chain from the start one. */ | |
1230 | for (; tlock->hash < tdb->header.hash_size; tlock->hash++) { | |
1231 | if (tdb_lock(tdb, tlock->hash, F_WRLCK) == -1) | |
1232 | return -1; | |
1233 | ||
1234 | /* No previous record? Start at top of chain. */ | |
1235 | if (!tlock->off) { | |
1236 | if (ofs_read(tdb, TDB_HASH_TOP(tlock->hash), | |
1237 | &tlock->off) == -1) | |
1238 | goto fail; | |
1239 | } else { | |
1240 | /* Otherwise unlock the previous record. */ | |
1241 | if (unlock_record(tdb, tlock->off) != 0) | |
1242 | goto fail; | |
1243 | } | |
1244 | ||
1245 | if (want_next) { | |
1246 | /* We have offset of old record: grab next */ | |
1247 | if (rec_read(tdb, tlock->off, rec) == -1) | |
1248 | goto fail; | |
1249 | tlock->off = rec->next; | |
1250 | } | |
1251 | ||
1252 | /* Iterate through chain */ | |
1253 | while( tlock->off) { | |
1254 | tdb_off current; | |
1255 | if (rec_read(tdb, tlock->off, rec) == -1) | |
1256 | goto fail; | |
1257 | if (!TDB_DEAD(rec)) { | |
1258 | /* Woohoo: we found one! */ | |
1259 | if (lock_record(tdb, tlock->off) != 0) | |
1260 | goto fail; | |
1261 | return tlock->off; | |
1262 | } | |
1263 | /* Try to clean dead ones from old traverses */ | |
1264 | current = tlock->off; | |
1265 | tlock->off = rec->next; | |
1266 | if (!tdb->read_only && | |
1267 | do_delete(tdb, current, rec) != 0) | |
1268 | goto fail; | |
1269 | } | |
1270 | tdb_unlock(tdb, tlock->hash, F_WRLCK); | |
1271 | want_next = 0; | |
1272 | } | |
1273 | /* We finished iteration without finding anything */ | |
1274 | return TDB_ERRCODE(TDB_SUCCESS, 0); | |
1275 | ||
1276 | fail: | |
1277 | tlock->off = 0; | |
1278 | if (tdb_unlock(tdb, tlock->hash, F_WRLCK) != 0) | |
1279 | TDB_LOG((tdb, 0, "tdb_next_lock: On error unlock failed!\n")); | |
1280 | return -1; | |
1281 | } | |
1282 | ||
1283 | /* traverse the entire database - calling fn(tdb, key, data) on each element. | |
1284 | return -1 on error or the record count traversed | |
1285 | if fn is NULL then it is not called | |
1286 | a non-zero return value from fn() indicates that the traversal should stop | |
1287 | */ | |
1288 | int tdb_traverse(TDB_CONTEXT *tdb, tdb_traverse_func fn, void *state) | |
1289 | { | |
1290 | TDB_DATA key, dbuf; | |
1291 | struct list_struct rec; | |
1292 | struct tdb_traverse_lock tl = { NULL, 0, 0 }; | |
1293 | int ret, count = 0; | |
1294 | ||
1295 | /* This was in the initializaton, above, but the IRIX compiler | |
1296 | * did not like it. crh | |
1297 | */ | |
1298 | tl.next = tdb->travlocks.next; | |
1299 | ||
1300 | /* fcntl locks don't stack: beware traverse inside traverse */ | |
1301 | tdb->travlocks.next = &tl; | |
1302 | ||
1303 | /* tdb_next_lock places locks on the record returned, and its chain */ | |
1304 | while ((ret = tdb_next_lock(tdb, &tl, &rec)) > 0) { | |
1305 | count++; | |
1306 | /* now read the full record */ | |
1307 | key.dptr = tdb_alloc_read(tdb, tl.off + sizeof(rec), | |
1308 | rec.key_len + rec.data_len); | |
1309 | if (!key.dptr) { | |
1310 | ret = -1; | |
1311 | if (tdb_unlock(tdb, tl.hash, F_WRLCK) != 0) | |
1312 | goto out; | |
1313 | if (unlock_record(tdb, tl.off) != 0) | |
1314 | TDB_LOG((tdb, 0, "tdb_traverse: key.dptr == NULL and unlock_record failed!\n")); | |
1315 | goto out; | |
1316 | } | |
1317 | key.dsize = rec.key_len; | |
1318 | dbuf.dptr = key.dptr + rec.key_len; | |
1319 | dbuf.dsize = rec.data_len; | |
1320 | ||
1321 | /* Drop chain lock, call out */ | |
1322 | if (tdb_unlock(tdb, tl.hash, F_WRLCK) != 0) { | |
1323 | ret = -1; | |
1324 | goto out; | |
1325 | } | |
1326 | if (fn && fn(tdb, key, dbuf, state)) { | |
1327 | /* They want us to terminate traversal */ | |
1328 | ret = count; | |
1329 | if (unlock_record(tdb, tl.off) != 0) { | |
1330 | TDB_LOG((tdb, 0, "tdb_traverse: unlock_record failed!\n"));; | |
1331 | ret = -1; | |
1332 | } | |
1333 | tdb->travlocks.next = tl.next; | |
1334 | SAFE_FREE(key.dptr); | |
1335 | return count; | |
1336 | } | |
1337 | SAFE_FREE(key.dptr); | |
1338 | } | |
1339 | out: | |
1340 | tdb->travlocks.next = tl.next; | |
1341 | if (ret < 0) | |
1342 | return -1; | |
1343 | else | |
1344 | return count; | |
1345 | } | |
1346 | ||
1347 | /* find the first entry in the database and return its key */ | |
1348 | TDB_DATA tdb_firstkey(TDB_CONTEXT *tdb) | |
1349 | { | |
1350 | TDB_DATA key; | |
1351 | struct list_struct rec; | |
1352 | ||
1353 | /* release any old lock */ | |
1354 | if (unlock_record(tdb, tdb->travlocks.off) != 0) | |
1355 | return tdb_null; | |
1356 | tdb->travlocks.off = tdb->travlocks.hash = 0; | |
1357 | ||
1358 | if (tdb_next_lock(tdb, &tdb->travlocks, &rec) <= 0) | |
1359 | return tdb_null; | |
1360 | /* now read the key */ | |
1361 | key.dsize = rec.key_len; | |
1362 | key.dptr =tdb_alloc_read(tdb,tdb->travlocks.off+sizeof(rec),key.dsize); | |
1363 | if (tdb_unlock(tdb, BUCKET(tdb->travlocks.hash), F_WRLCK) != 0) | |
1364 | TDB_LOG((tdb, 0, "tdb_firstkey: error occurred while tdb_unlocking!\n")); | |
1365 | return key; | |
1366 | } | |
1367 | ||
1368 | /* find the next entry in the database, returning its key */ | |
1369 | TDB_DATA tdb_nextkey(TDB_CONTEXT *tdb, TDB_DATA oldkey) | |
1370 | { | |
1371 | u32 oldhash; | |
1372 | TDB_DATA key = tdb_null; | |
1373 | struct list_struct rec; | |
1374 | char *k = NULL; | |
1375 | ||
1376 | /* Is locked key the old key? If so, traverse will be reliable. */ | |
1377 | if (tdb->travlocks.off) { | |
1378 | if (tdb_lock(tdb,tdb->travlocks.hash,F_WRLCK)) | |
1379 | return tdb_null; | |
1380 | if (rec_read(tdb, tdb->travlocks.off, &rec) == -1 | |
1381 | || !(k = tdb_alloc_read(tdb,tdb->travlocks.off+sizeof(rec), | |
1382 | rec.key_len)) | |
1383 | || memcmp(k, oldkey.dptr, oldkey.dsize) != 0) { | |
1384 | /* No, it wasn't: unlock it and start from scratch */ | |
1385 | if (unlock_record(tdb, tdb->travlocks.off) != 0) | |
1386 | return tdb_null; | |
1387 | if (tdb_unlock(tdb, tdb->travlocks.hash, F_WRLCK) != 0) | |
1388 | return tdb_null; | |
1389 | tdb->travlocks.off = 0; | |
1390 | } | |
1391 | ||
1392 | SAFE_FREE(k); | |
1393 | } | |
1394 | ||
1395 | if (!tdb->travlocks.off) { | |
1396 | /* No previous element: do normal find, and lock record */ | |
1397 | tdb->travlocks.off = tdb_find_lock(tdb, oldkey, F_WRLCK, &rec); | |
1398 | if (!tdb->travlocks.off) | |
1399 | return tdb_null; | |
1400 | tdb->travlocks.hash = BUCKET(rec.full_hash); | |
1401 | if (lock_record(tdb, tdb->travlocks.off) != 0) { | |
1402 | TDB_LOG((tdb, 0, "tdb_nextkey: lock_record failed (%s)!\n", strerror(errno))); | |
1403 | return tdb_null; | |
1404 | } | |
1405 | } | |
1406 | oldhash = tdb->travlocks.hash; | |
1407 | ||
1408 | /* Grab next record: locks chain and returned record, | |
1409 | unlocks old record */ | |
1410 | if (tdb_next_lock(tdb, &tdb->travlocks, &rec) > 0) { | |
1411 | key.dsize = rec.key_len; | |
1412 | key.dptr = tdb_alloc_read(tdb, tdb->travlocks.off+sizeof(rec), | |
1413 | key.dsize); | |
1414 | /* Unlock the chain of this new record */ | |
1415 | if (tdb_unlock(tdb, tdb->travlocks.hash, F_WRLCK) != 0) | |
1416 | TDB_LOG((tdb, 0, "tdb_nextkey: WARNING tdb_unlock failed!\n")); | |
1417 | } | |
1418 | /* Unlock the chain of old record */ | |
1419 | if (tdb_unlock(tdb, BUCKET(oldhash), F_WRLCK) != 0) | |
1420 | TDB_LOG((tdb, 0, "tdb_nextkey: WARNING tdb_unlock failed!\n")); | |
1421 | return key; | |
1422 | } | |
1423 | ||
1424 | /* delete an entry in the database given a key */ | |
1425 | int tdb_delete(TDB_CONTEXT *tdb, TDB_DATA key) | |
1426 | { | |
1427 | tdb_off rec_ptr; | |
1428 | struct list_struct rec; | |
1429 | int ret; | |
1430 | ||
1431 | if (!(rec_ptr = tdb_find_lock(tdb, key, F_WRLCK, &rec))) | |
1432 | return -1; | |
1433 | ret = do_delete(tdb, rec_ptr, &rec); | |
1434 | if (tdb_unlock(tdb, BUCKET(rec.full_hash), F_WRLCK) != 0) | |
1435 | TDB_LOG((tdb, 0, "tdb_delete: WARNING tdb_unlock failed!\n")); | |
1436 | return ret; | |
1437 | } | |
1438 | ||
1439 | /* store an element in the database, replacing any existing element | |
1440 | with the same key | |
1441 | ||
1442 | return 0 on success, -1 on failure | |
1443 | */ | |
1444 | int tdb_store(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, int flag) | |
1445 | { | |
1446 | struct list_struct rec; | |
1447 | u32 hash; | |
1448 | tdb_off rec_ptr; | |
1449 | char *p = NULL; | |
1450 | int ret = 0; | |
1451 | ||
1452 | /* find which hash bucket it is in */ | |
1453 | hash = tdb_hash(&key); | |
1454 | if (!tdb_keylocked(tdb, hash)) | |
1455 | return -1; | |
1456 | if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1) | |
1457 | return -1; | |
1458 | ||
1459 | /* check for it existing, on insert. */ | |
1460 | if (flag == TDB_INSERT) { | |
1461 | if (tdb_exists(tdb, key)) { | |
1462 | tdb->ecode = TDB_ERR_EXISTS; | |
1463 | goto fail; | |
1464 | } | |
1465 | } else { | |
1466 | /* first try in-place update, on modify or replace. */ | |
1467 | if (tdb_update(tdb, key, dbuf) == 0) | |
1468 | goto out; | |
1469 | if (flag == TDB_MODIFY && tdb->ecode == TDB_ERR_NOEXIST) | |
1470 | goto fail; | |
1471 | } | |
1472 | /* reset the error code potentially set by the tdb_update() */ | |
1473 | tdb->ecode = TDB_SUCCESS; | |
1474 | ||
1475 | /* delete any existing record - if it doesn't exist we don't | |
1476 | care. Doing this first reduces fragmentation, and avoids | |
1477 | coalescing with `allocated' block before it's updated. */ | |
1478 | if (flag != TDB_INSERT) | |
1479 | tdb_delete(tdb, key); | |
1480 | ||
1481 | /* Copy key+value *before* allocating free space in case malloc | |
1482 | fails and we are left with a dead spot in the tdb. */ | |
1483 | ||
1484 | if (!(p = (char *)malloc(key.dsize + dbuf.dsize))) { | |
1485 | tdb->ecode = TDB_ERR_OOM; | |
1486 | goto fail; | |
1487 | } | |
1488 | ||
1489 | memcpy(p, key.dptr, key.dsize); | |
1490 | if (dbuf.dsize) | |
1491 | memcpy(p+key.dsize, dbuf.dptr, dbuf.dsize); | |
1492 | ||
1493 | /* now we're into insert / modify / replace of a record which | |
1494 | * we know could not be optimised by an in-place store (for | |
1495 | * various reasons). */ | |
1496 | if (!(rec_ptr = tdb_allocate(tdb, key.dsize + dbuf.dsize, &rec))) | |
1497 | goto fail; | |
1498 | ||
1499 | /* Read hash top into next ptr */ | |
1500 | if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec.next) == -1) | |
1501 | goto fail; | |
1502 | ||
1503 | rec.key_len = key.dsize; | |
1504 | rec.data_len = dbuf.dsize; | |
1505 | rec.full_hash = hash; | |
1506 | rec.magic = TDB_MAGIC; | |
1507 | ||
1508 | /* write out and point the top of the hash chain at it */ | |
1509 | if (rec_write(tdb, rec_ptr, &rec) == -1 | |
1510 | || tdb_write(tdb, rec_ptr+sizeof(rec), p, key.dsize+dbuf.dsize)==-1 | |
1511 | || ofs_write(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) { | |
1512 | /* Need to tdb_unallocate() here */ | |
1513 | goto fail; | |
1514 | } | |
1515 | out: | |
1516 | SAFE_FREE(p); | |
1517 | tdb_unlock(tdb, BUCKET(hash), F_WRLCK); | |
1518 | return ret; | |
1519 | fail: | |
1520 | ret = -1; | |
1521 | goto out; | |
1522 | } | |
1523 | ||
1524 | /* Attempt to append data to an entry in place - this only works if the new data size | |
1525 | is <= the old data size and the key exists. | |
1526 | on failure return -1. Record must be locked before calling. | |
1527 | */ | |
1528 | static int tdb_append_inplace(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA new_dbuf) | |
1529 | { | |
1530 | struct list_struct rec; | |
1531 | tdb_off rec_ptr; | |
1532 | ||
1533 | /* find entry */ | |
1534 | if (!(rec_ptr = tdb_find(tdb, key, tdb_hash(&key), &rec))) | |
1535 | return -1; | |
1536 | ||
1537 | /* Append of 0 is always ok. */ | |
1538 | if (new_dbuf.dsize == 0) | |
1539 | return 0; | |
1540 | ||
1541 | /* must be long enough for key, old data + new data and tailer */ | |
1542 | if (rec.rec_len < key.dsize + rec.data_len + new_dbuf.dsize + sizeof(tdb_off)) { | |
1543 | /* No room. */ | |
1544 | tdb->ecode = TDB_SUCCESS; /* Not really an error */ | |
1545 | return -1; | |
1546 | } | |
1547 | ||
1548 | if (tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len + rec.data_len, | |
1549 | new_dbuf.dptr, new_dbuf.dsize) == -1) | |
1550 | return -1; | |
1551 | ||
1552 | /* update size */ | |
1553 | rec.data_len += new_dbuf.dsize; | |
1554 | return rec_write(tdb, rec_ptr, &rec); | |
1555 | } | |
1556 | ||
1557 | /* Append to an entry. Create if not exist. */ | |
1558 | ||
1559 | int tdb_append(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA new_dbuf) | |
1560 | { | |
1561 | struct list_struct rec; | |
1562 | u32 hash; | |
1563 | tdb_off rec_ptr; | |
1564 | char *p = NULL; | |
1565 | int ret = 0; | |
1566 | size_t new_data_size = 0; | |
1567 | ||
1568 | /* find which hash bucket it is in */ | |
1569 | hash = tdb_hash(&key); | |
1570 | if (!tdb_keylocked(tdb, hash)) | |
1571 | return -1; | |
1572 | if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1) | |
1573 | return -1; | |
1574 | ||
1575 | /* first try in-place. */ | |
1576 | if (tdb_append_inplace(tdb, key, new_dbuf) == 0) | |
1577 | goto out; | |
1578 | ||
1579 | /* reset the error code potentially set by the tdb_append_inplace() */ | |
1580 | tdb->ecode = TDB_SUCCESS; | |
1581 | ||
1582 | /* find entry */ | |
1583 | if (!(rec_ptr = tdb_find(tdb, key, hash, &rec))) { | |
1584 | if (tdb->ecode != TDB_ERR_NOEXIST) | |
1585 | goto fail; | |
1586 | ||
1587 | /* Not found - create. */ | |
1588 | ||
1589 | ret = tdb_store(tdb, key, new_dbuf, TDB_INSERT); | |
1590 | goto out; | |
1591 | } | |
1592 | ||
1593 | new_data_size = rec.data_len + new_dbuf.dsize; | |
1594 | ||
1595 | /* Copy key+old_value+value *before* allocating free space in case malloc | |
1596 | fails and we are left with a dead spot in the tdb. */ | |
1597 | ||
1598 | if (!(p = (char *)malloc(key.dsize + new_data_size))) { | |
1599 | tdb->ecode = TDB_ERR_OOM; | |
1600 | goto fail; | |
1601 | } | |
1602 | ||
1603 | /* Copy the key in place. */ | |
1604 | memcpy(p, key.dptr, key.dsize); | |
1605 | ||
1606 | /* Now read the old data into place. */ | |
1607 | if (rec.data_len && | |
1608 | tdb_read(tdb, rec_ptr + sizeof(rec) + rec.key_len, p + key.dsize, rec.data_len, 0) == -1) | |
1609 | goto fail; | |
1610 | ||
1611 | /* Finally append the new data. */ | |
1612 | if (new_dbuf.dsize) | |
1613 | memcpy(p+key.dsize+rec.data_len, new_dbuf.dptr, new_dbuf.dsize); | |
1614 | ||
1615 | /* delete any existing record - if it doesn't exist we don't | |
1616 | care. Doing this first reduces fragmentation, and avoids | |
1617 | coalescing with `allocated' block before it's updated. */ | |
1618 | ||
1619 | tdb_delete(tdb, key); | |
1620 | ||
1621 | if (!(rec_ptr = tdb_allocate(tdb, key.dsize + new_data_size, &rec))) | |
1622 | goto fail; | |
1623 | ||
1624 | /* Read hash top into next ptr */ | |
1625 | if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec.next) == -1) | |
1626 | goto fail; | |
1627 | ||
1628 | rec.key_len = key.dsize; | |
1629 | rec.data_len = new_data_size; | |
1630 | rec.full_hash = hash; | |
1631 | rec.magic = TDB_MAGIC; | |
1632 | ||
1633 | /* write out and point the top of the hash chain at it */ | |
1634 | if (rec_write(tdb, rec_ptr, &rec) == -1 | |
1635 | || tdb_write(tdb, rec_ptr+sizeof(rec), p, key.dsize+new_data_size)==-1 | |
1636 | || ofs_write(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) { | |
1637 | /* Need to tdb_unallocate() here */ | |
1638 | goto fail; | |
1639 | } | |
1640 | ||
1641 | out: | |
1642 | SAFE_FREE(p); | |
1643 | tdb_unlock(tdb, BUCKET(hash), F_WRLCK); | |
1644 | return ret; | |
1645 | ||
1646 | fail: | |
1647 | ret = -1; | |
1648 | goto out; | |
1649 | } | |
1650 | ||
1651 | static int tdb_already_open(dev_t device, | |
1652 | ino_t ino) | |
1653 | { | |
1654 | TDB_CONTEXT *i; | |
1655 | ||
1656 | for (i = tdbs; i; i = i->next) { | |
1657 | if (i->device == device && i->inode == ino) { | |
1658 | return 1; | |
1659 | } | |
1660 | } | |
1661 | ||
1662 | return 0; | |
1663 | } | |
1664 | ||
1665 | /* open the database, creating it if necessary | |
1666 | ||
1667 | The open_flags and mode are passed straight to the open call on the | |
1668 | database file. A flags value of O_WRONLY is invalid. The hash size | |
1669 | is advisory, use zero for a default value. | |
1670 | ||
1671 | Return is NULL on error, in which case errno is also set. Don't | |
1672 | try to call tdb_error or tdb_errname, just do strerror(errno). | |
1673 | ||
1674 | @param name may be NULL for internal databases. */ | |
1675 | TDB_CONTEXT *tdb_open(const char *name, int hash_size, int tdb_flags, | |
1676 | int open_flags, mode_t mode) | |
1677 | { | |
1678 | return tdb_open_ex(name, hash_size, tdb_flags, open_flags, mode, NULL); | |
1679 | } | |
1680 | ||
1681 | ||
1682 | TDB_CONTEXT *tdb_open_ex(const char *name, int hash_size, int tdb_flags, | |
1683 | int open_flags, mode_t mode, | |
1684 | tdb_log_func log_fn) | |
1685 | { | |
1686 | TDB_CONTEXT *tdb; | |
1687 | struct stat st; | |
1688 | int rev = 0, locked; | |
1689 | unsigned char *vp; | |
1690 | u32 vertest; | |
1691 | ||
1692 | if (!(tdb = calloc(1, sizeof *tdb))) { | |
1693 | /* Can't log this */ | |
1694 | errno = ENOMEM; | |
1695 | goto fail; | |
1696 | } | |
1697 | tdb->fd = -1; | |
1698 | tdb->name = NULL; | |
1699 | tdb->map_ptr = NULL; | |
1700 | tdb->lockedkeys = NULL; | |
1701 | tdb->flags = tdb_flags; | |
1702 | tdb->open_flags = open_flags; | |
1703 | tdb->log_fn = log_fn; | |
1704 | ||
1705 | if ((open_flags & O_ACCMODE) == O_WRONLY) { | |
1706 | TDB_LOG((tdb, 0, "tdb_open_ex: can't open tdb %s write-only\n", | |
1707 | name)); | |
1708 | errno = EINVAL; | |
1709 | goto fail; | |
1710 | } | |
1711 | ||
1712 | if (hash_size == 0) | |
1713 | hash_size = DEFAULT_HASH_SIZE; | |
1714 | if ((open_flags & O_ACCMODE) == O_RDONLY) { | |
1715 | tdb->read_only = 1; | |
1716 | /* read only databases don't do locking or clear if first */ | |
1717 | tdb->flags |= TDB_NOLOCK; | |
1718 | tdb->flags &= ~TDB_CLEAR_IF_FIRST; | |
1719 | } | |
1720 | ||
1721 | /* internal databases don't mmap or lock, and start off cleared */ | |
1722 | if (tdb->flags & TDB_INTERNAL) { | |
1723 | tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP); | |
1724 | tdb->flags &= ~TDB_CLEAR_IF_FIRST; | |
1725 | if (tdb_new_database(tdb, hash_size) != 0) { | |
1726 | TDB_LOG((tdb, 0, "tdb_open_ex: tdb_new_database failed!")); | |
1727 | goto fail; | |
1728 | } | |
1729 | goto internal; | |
1730 | } | |
1731 | ||
1732 | if ((tdb->fd = open(name, open_flags, mode)) == -1) { | |
1733 | TDB_LOG((tdb, 5, "tdb_open_ex: could not open file %s: %s\n", | |
1734 | name, strerror(errno))); | |
1735 | goto fail; /* errno set by open(2) */ | |
1736 | } | |
1737 | ||
1738 | /* ensure there is only one process initialising at once */ | |
1739 | if (tdb_brlock(tdb, GLOBAL_LOCK, F_WRLCK, F_SETLKW, 0) == -1) { | |
1740 | TDB_LOG((tdb, 0, "tdb_open_ex: failed to get global lock on %s: %s\n", | |
1741 | name, strerror(errno))); | |
1742 | goto fail; /* errno set by tdb_brlock */ | |
1743 | } | |
1744 | ||
1745 | /* we need to zero database if we are the only one with it open */ | |
1746 | if ((locked = (tdb_brlock(tdb, ACTIVE_LOCK, F_WRLCK, F_SETLK, 0) == 0)) | |
1747 | && (tdb_flags & TDB_CLEAR_IF_FIRST)) { | |
1748 | open_flags |= O_CREAT; | |
1749 | if (ftruncate(tdb->fd, 0) == -1) { | |
1750 | TDB_LOG((tdb, 0, "tdb_open_ex: " | |
1751 | "failed to truncate %s: %s\n", | |
1752 | name, strerror(errno))); | |
1753 | goto fail; /* errno set by ftruncate */ | |
1754 | } | |
1755 | } | |
1756 | ||
1757 | if (read(tdb->fd, &tdb->header, sizeof(tdb->header)) != sizeof(tdb->header) | |
1758 | || strcmp(tdb->header.magic_food, TDB_MAGIC_FOOD) != 0 | |
1759 | || (tdb->header.version != TDB_VERSION | |
1760 | && !(rev = (tdb->header.version==TDB_BYTEREV(TDB_VERSION))))) { | |
1761 | /* its not a valid database - possibly initialise it */ | |
1762 | if (!(open_flags & O_CREAT) || tdb_new_database(tdb, hash_size) == -1) { | |
1763 | errno = EIO; /* ie bad format or something */ | |
1764 | goto fail; | |
1765 | } | |
1766 | rev = (tdb->flags & TDB_CONVERT); | |
1767 | } | |
1768 | vp = (unsigned char *)&tdb->header.version; | |
1769 | vertest = (((u32)vp[0]) << 24) | (((u32)vp[1]) << 16) | | |
1770 | (((u32)vp[2]) << 8) | (u32)vp[3]; | |
1771 | tdb->flags |= (vertest==TDB_VERSION) ? TDB_BIGENDIAN : 0; | |
1772 | if (!rev) | |
1773 | tdb->flags &= ~TDB_CONVERT; | |
1774 | else { | |
1775 | tdb->flags |= TDB_CONVERT; | |
1776 | convert(&tdb->header, sizeof(tdb->header)); | |
1777 | } | |
1778 | if (fstat(tdb->fd, &st) == -1) | |
1779 | goto fail; | |
1780 | ||
1781 | /* Is it already in the open list? If so, fail. */ | |
1782 | if (tdb_already_open(st.st_dev, st.st_ino)) { | |
1783 | TDB_LOG((tdb, 2, "tdb_open_ex: " | |
1784 | "%s (%d,%d) is already open in this process\n", | |
1785 | name, st.st_dev, st.st_ino)); | |
1786 | errno = EBUSY; | |
1787 | goto fail; | |
1788 | } | |
1789 | ||
1790 | if (!(tdb->name = (char *)strdup(name))) { | |
1791 | errno = ENOMEM; | |
1792 | goto fail; | |
1793 | } | |
1794 | ||
1795 | tdb->map_size = st.st_size; | |
1796 | tdb->device = st.st_dev; | |
1797 | tdb->inode = st.st_ino; | |
1798 | tdb->locked = calloc(tdb->header.hash_size+1, sizeof(tdb->locked[0])); | |
1799 | if (!tdb->locked) { | |
1800 | TDB_LOG((tdb, 2, "tdb_open_ex: " | |
1801 | "failed to allocate lock structure for %s\n", | |
1802 | name)); | |
1803 | errno = ENOMEM; | |
1804 | goto fail; | |
1805 | } | |
1806 | tdb_mmap(tdb); | |
1807 | if (locked) { | |
1808 | if (!tdb->read_only) | |
1809 | if (tdb_clear_spinlocks(tdb) != 0) { | |
1810 | TDB_LOG((tdb, 0, "tdb_open_ex: " | |
1811 | "failed to clear spinlock\n")); | |
1812 | goto fail; | |
1813 | } | |
1814 | if (tdb_brlock(tdb, ACTIVE_LOCK, F_UNLCK, F_SETLK, 0) == -1) { | |
1815 | TDB_LOG((tdb, 0, "tdb_open_ex: " | |
1816 | "failed to take ACTIVE_LOCK on %s: %s\n", | |
1817 | name, strerror(errno))); | |
1818 | goto fail; | |
1819 | } | |
1820 | } | |
1821 | /* leave this lock in place to indicate it's in use */ | |
1822 | if (tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0) == -1) | |
1823 | goto fail; | |
1824 | ||
1825 | internal: | |
1826 | /* Internal (memory-only) databases skip all the code above to | |
1827 | * do with disk files, and resume here by releasing their | |
1828 | * global lock and hooking into the active list. */ | |
1829 | if (tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0) == -1) | |
1830 | goto fail; | |
1831 | tdb->next = tdbs; | |
1832 | tdbs = tdb; | |
1833 | return tdb; | |
1834 | ||
1835 | fail: | |
1836 | { int save_errno = errno; | |
1837 | ||
1838 | if (!tdb) | |
1839 | return NULL; | |
1840 | ||
1841 | if (tdb->map_ptr) { | |
1842 | if (tdb->flags & TDB_INTERNAL) | |
1843 | SAFE_FREE(tdb->map_ptr); | |
1844 | else | |
1845 | tdb_munmap(tdb); | |
1846 | } | |
1847 | SAFE_FREE(tdb->name); | |
1848 | if (tdb->fd != -1) | |
1849 | if (close(tdb->fd) != 0) | |
1850 | TDB_LOG((tdb, 5, "tdb_open_ex: failed to close tdb->fd on error!\n")); | |
1851 | SAFE_FREE(tdb->locked); | |
1852 | SAFE_FREE(tdb); | |
1853 | errno = save_errno; | |
1854 | return NULL; | |
1855 | } | |
1856 | } | |
1857 | ||
1858 | /** | |
1859 | * Close a database. | |
1860 | * | |
1861 | * @returns -1 for error; 0 for success. | |
1862 | **/ | |
1863 | int tdb_close(TDB_CONTEXT *tdb) | |
1864 | { | |
1865 | TDB_CONTEXT **i; | |
1866 | int ret = 0; | |
1867 | ||
1868 | if (tdb->map_ptr) { | |
1869 | if (tdb->flags & TDB_INTERNAL) | |
1870 | SAFE_FREE(tdb->map_ptr); | |
1871 | else | |
1872 | tdb_munmap(tdb); | |
1873 | } | |
1874 | SAFE_FREE(tdb->name); | |
1875 | if (tdb->fd != -1) | |
1876 | ret = close(tdb->fd); | |
1877 | SAFE_FREE(tdb->locked); | |
1878 | SAFE_FREE(tdb->lockedkeys); | |
1879 | ||
1880 | /* Remove from contexts list */ | |
1881 | for (i = &tdbs; *i; i = &(*i)->next) { | |
1882 | if (*i == tdb) { | |
1883 | *i = tdb->next; | |
1884 | break; | |
1885 | } | |
1886 | } | |
1887 | ||
1888 | memset(tdb, 0, sizeof(*tdb)); | |
1889 | SAFE_FREE(tdb); | |
1890 | ||
1891 | return ret; | |
1892 | } | |
1893 | ||
1894 | /* lock/unlock entire database */ | |
1895 | int tdb_lockall(TDB_CONTEXT *tdb) | |
1896 | { | |
1897 | u32 i; | |
1898 | ||
1899 | /* There are no locks on read-only dbs */ | |
1900 | if (tdb->read_only) | |
1901 | return TDB_ERRCODE(TDB_ERR_LOCK, -1); | |
1902 | if (tdb->lockedkeys) | |
1903 | return TDB_ERRCODE(TDB_ERR_NOLOCK, -1); | |
1904 | for (i = 0; i < tdb->header.hash_size; i++) | |
1905 | if (tdb_lock(tdb, i, F_WRLCK)) | |
1906 | break; | |
1907 | ||
1908 | /* If error, release locks we have... */ | |
1909 | if (i < tdb->header.hash_size) { | |
1910 | u32 j; | |
1911 | ||
1912 | for ( j = 0; j < i; j++) | |
1913 | tdb_unlock(tdb, j, F_WRLCK); | |
1914 | return TDB_ERRCODE(TDB_ERR_NOLOCK, -1); | |
1915 | } | |
1916 | ||
1917 | return 0; | |
1918 | } | |
1919 | void tdb_unlockall(TDB_CONTEXT *tdb) | |
1920 | { | |
1921 | u32 i; | |
1922 | for (i=0; i < tdb->header.hash_size; i++) | |
1923 | tdb_unlock(tdb, i, F_WRLCK); | |
1924 | } | |
1925 | ||
1926 | int tdb_lockkeys(TDB_CONTEXT *tdb, u32 number, TDB_DATA keys[]) | |
1927 | { | |
1928 | u32 i, j, hash; | |
1929 | ||
1930 | /* Can't lock more keys if already locked */ | |
1931 | if (tdb->lockedkeys) | |
1932 | return TDB_ERRCODE(TDB_ERR_NOLOCK, -1); | |
1933 | if (!(tdb->lockedkeys = malloc(sizeof(u32) * (number+1)))) | |
1934 | return TDB_ERRCODE(TDB_ERR_OOM, -1); | |
1935 | /* First number in array is # keys */ | |
1936 | tdb->lockedkeys[0] = number; | |
1937 | ||
1938 | /* Insertion sort by bucket */ | |
1939 | for (i = 0; i < number; i++) { | |
1940 | hash = tdb_hash(&keys[i]); | |
1941 | for (j = 0; j < i && BUCKET(tdb->lockedkeys[j+1]) < BUCKET(hash); j++); | |
1942 | memmove(&tdb->lockedkeys[j+2], &tdb->lockedkeys[j+1], sizeof(u32) * (i-j)); | |
1943 | tdb->lockedkeys[j+1] = hash; | |
1944 | } | |
1945 | /* Finally, lock in order */ | |
1946 | for (i = 0; i < number; i++) | |
1947 | if (tdb_lock(tdb, i, F_WRLCK)) | |
1948 | break; | |
1949 | ||
1950 | /* If error, release locks we have... */ | |
1951 | if (i < number) { | |
1952 | for ( j = 0; j < i; j++) | |
1953 | tdb_unlock(tdb, j, F_WRLCK); | |
1954 | SAFE_FREE(tdb->lockedkeys); | |
1955 | return TDB_ERRCODE(TDB_ERR_NOLOCK, -1); | |
1956 | } | |
1957 | return 0; | |
1958 | } | |
1959 | ||
1960 | /* Unlock the keys previously locked by tdb_lockkeys() */ | |
1961 | void tdb_unlockkeys(TDB_CONTEXT *tdb) | |
1962 | { | |
1963 | u32 i; | |
1964 | if (!tdb->lockedkeys) | |
1965 | return; | |
1966 | for (i = 0; i < tdb->lockedkeys[0]; i++) | |
1967 | tdb_unlock(tdb, tdb->lockedkeys[i+1], F_WRLCK); | |
1968 | SAFE_FREE(tdb->lockedkeys); | |
1969 | } | |
1970 | ||
1971 | /* lock/unlock one hash chain. This is meant to be used to reduce | |
1972 | contention - it cannot guarantee how many records will be locked */ | |
1973 | int tdb_chainlock(TDB_CONTEXT *tdb, TDB_DATA key) | |
1974 | { | |
1975 | return tdb_lock(tdb, BUCKET(tdb_hash(&key)), F_WRLCK); | |
1976 | } | |
1977 | ||
1978 | int tdb_chainunlock(TDB_CONTEXT *tdb, TDB_DATA key) | |
1979 | { | |
1980 | return tdb_unlock(tdb, BUCKET(tdb_hash(&key)), F_WRLCK); | |
1981 | } | |
1982 | ||
1983 | int tdb_chainlock_read(TDB_CONTEXT *tdb, TDB_DATA key) | |
1984 | { | |
1985 | return tdb_lock(tdb, BUCKET(tdb_hash(&key)), F_RDLCK); | |
1986 | } | |
1987 | ||
1988 | int tdb_chainunlock_read(TDB_CONTEXT *tdb, TDB_DATA key) | |
1989 | { | |
1990 | return tdb_unlock(tdb, BUCKET(tdb_hash(&key)), F_RDLCK); | |
1991 | } | |
1992 | ||
1993 | ||
1994 | /* register a loging function */ | |
1995 | void tdb_logging_function(TDB_CONTEXT *tdb, void (*fn)(TDB_CONTEXT *, int , const char *, ...)) | |
1996 | { | |
1997 | tdb->log_fn = fn; | |
1998 | } | |
1999 | ||
2000 | ||
2001 | /* reopen a tdb - this is used after a fork to ensure that we have an independent | |
2002 | seek pointer from our parent and to re-establish locks */ | |
2003 | int tdb_reopen(TDB_CONTEXT *tdb) | |
2004 | { | |
2005 | struct stat st; | |
2006 | ||
2007 | if (tdb_munmap(tdb) != 0) { | |
2008 | TDB_LOG((tdb, 0, "tdb_reopen: munmap failed (%s)\n", strerror(errno))); | |
2009 | goto fail; | |
2010 | } | |
2011 | if (close(tdb->fd) != 0) | |
2012 | TDB_LOG((tdb, 0, "tdb_reopen: WARNING closing tdb->fd failed!\n")); | |
2013 | tdb->fd = open(tdb->name, tdb->open_flags & ~(O_CREAT|O_TRUNC), 0); | |
2014 | if (tdb->fd == -1) { | |
2015 | TDB_LOG((tdb, 0, "tdb_reopen: open failed (%s)\n", strerror(errno))); | |
2016 | goto fail; | |
2017 | } | |
2018 | if (fstat(tdb->fd, &st) != 0) { | |
2019 | TDB_LOG((tdb, 0, "tdb_reopen: fstat failed (%s)\n", strerror(errno))); | |
2020 | goto fail; | |
2021 | } | |
2022 | if (st.st_ino != tdb->inode || st.st_dev != tdb->device) { | |
2023 | TDB_LOG((tdb, 0, "tdb_reopen: file dev/inode has changed!\n")); | |
2024 | goto fail; | |
2025 | } | |
2026 | tdb_mmap(tdb); | |
2027 | if (tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0) == -1) { | |
2028 | TDB_LOG((tdb, 0, "tdb_reopen: failed to obtain active lock\n")); | |
2029 | goto fail; | |
2030 | } | |
2031 | ||
2032 | return 0; | |
2033 | ||
2034 | fail: | |
2035 | tdb_close(tdb); | |
2036 | return -1; | |
2037 | } | |
2038 | ||
2039 | /* reopen all tdb's */ | |
2040 | int tdb_reopen_all(void) | |
2041 | { | |
2042 | TDB_CONTEXT *tdb; | |
2043 | ||
2044 | for (tdb=tdbs; tdb; tdb = tdb->next) { | |
2045 | if (tdb_reopen(tdb) != 0) return -1; | |
2046 | } | |
2047 | ||
2048 | return 0; | |
2049 | } |