summaryrefslogtreecommitdiff
path: root/lib/tdb2/tdb.c
blob: 5e965acabd1f8f9295f27cd9d22ad7d6a3d7d79a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
 /*
   Trivial Database 2: fetch, store and misc routines.
   Copyright (C) Rusty Russell 2010

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 3 of the License, or (at your option) any later version.

   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "private.h"
#ifndef HAVE_LIBREPLACE
#include <ccan/asprintf/asprintf.h>
#include <stdarg.h>
#endif

static enum TDB_ERROR update_rec_hdr(struct tdb_context *tdb,
				     tdb_off_t off,
				     tdb_len_t keylen,
				     tdb_len_t datalen,
				     struct tdb_used_record *rec,
				     uint64_t h)
{
	uint64_t dataroom = rec_data_length(rec) + rec_extra_padding(rec);
	enum TDB_ERROR ecode;

	ecode = set_header(tdb, rec, TDB_USED_MAGIC, keylen, datalen,
			   keylen + dataroom, h);
	if (ecode == TDB_SUCCESS) {
		ecode = tdb_write_convert(tdb, off, rec, sizeof(*rec));
	}
	return ecode;
}

static enum TDB_ERROR replace_data(struct tdb_context *tdb,
				   struct hash_info *h,
				   struct tdb_data key, struct tdb_data dbuf,
				   tdb_off_t old_off, tdb_len_t old_room,
				   bool growing)
{
	tdb_off_t new_off;
	enum TDB_ERROR ecode;

	/* Allocate a new record. */
	new_off = alloc(tdb, key.dsize, dbuf.dsize, h->h, TDB_USED_MAGIC,
			growing);
	if (TDB_OFF_IS_ERR(new_off)) {
		return TDB_OFF_TO_ERR(new_off);
	}

	/* We didn't like the existing one: remove it. */
	if (old_off) {
		tdb->stats.frees++;
		ecode = add_free_record(tdb, old_off,
					sizeof(struct tdb_used_record)
					+ key.dsize + old_room,
					TDB_LOCK_WAIT, true);
		if (ecode == TDB_SUCCESS)
			ecode = replace_in_hash(tdb, h, new_off);
	} else {
		ecode = add_to_hash(tdb, h, new_off);
	}
	if (ecode != TDB_SUCCESS) {
		return ecode;
	}

	new_off += sizeof(struct tdb_used_record);
	ecode = tdb->tdb2.io->twrite(tdb, new_off, key.dptr, key.dsize);
	if (ecode != TDB_SUCCESS) {
		return ecode;
	}

	new_off += key.dsize;
	ecode = tdb->tdb2.io->twrite(tdb, new_off, dbuf.dptr, dbuf.dsize);
	if (ecode != TDB_SUCCESS) {
		return ecode;
	}

	if (tdb->flags & TDB_SEQNUM)
		tdb_inc_seqnum(tdb);

	return TDB_SUCCESS;
}

static enum TDB_ERROR update_data(struct tdb_context *tdb,
				  tdb_off_t off,
				  struct tdb_data dbuf,
				  tdb_len_t extra)
{
	enum TDB_ERROR ecode;

	ecode = tdb->tdb2.io->twrite(tdb, off, dbuf.dptr, dbuf.dsize);
	if (ecode == TDB_SUCCESS && extra) {
		/* Put a zero in; future versions may append other data. */
		ecode = tdb->tdb2.io->twrite(tdb, off + dbuf.dsize, "", 1);
	}
	if (tdb->flags & TDB_SEQNUM)
		tdb_inc_seqnum(tdb);

	return ecode;
}

enum TDB_ERROR tdb_store(struct tdb_context *tdb,
			 struct tdb_data key, struct tdb_data dbuf, int flag)
{
	struct hash_info h;
	tdb_off_t off;
	tdb_len_t old_room = 0;
	struct tdb_used_record rec;
	enum TDB_ERROR ecode;

	if (tdb->flags & TDB_VERSION1) {
		if (tdb1_store(tdb, key, dbuf, flag) == -1)
			return tdb->last_error;
		return TDB_SUCCESS;
	}

	off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
	if (TDB_OFF_IS_ERR(off)) {
		return tdb->last_error = TDB_OFF_TO_ERR(off);
	}

	/* Now we have lock on this hash bucket. */
	if (flag == TDB_INSERT) {
		if (off) {
			ecode = TDB_ERR_EXISTS;
			goto out;
		}
	} else {
		if (off) {
			old_room = rec_data_length(&rec)
				+ rec_extra_padding(&rec);
			if (old_room >= dbuf.dsize) {
				/* Can modify in-place.  Easy! */
				ecode = update_rec_hdr(tdb, off,
						       key.dsize, dbuf.dsize,
						       &rec, h.h);
				if (ecode != TDB_SUCCESS) {
					goto out;
				}
				ecode = update_data(tdb,
						    off + sizeof(rec)
						    + key.dsize, dbuf,
						    old_room - dbuf.dsize);
				if (ecode != TDB_SUCCESS) {
					goto out;
				}
				tdb_unlock_hashes(tdb, h.hlock_start,
						  h.hlock_range, F_WRLCK);
				return tdb->last_error = TDB_SUCCESS;
			}
		} else {
			if (flag == TDB_MODIFY) {
				/* if the record doesn't exist and we
				   are in TDB_MODIFY mode then we should fail
				   the store */
				ecode = TDB_ERR_NOEXIST;
				goto out;
			}
		}
	}

	/* If we didn't use the old record, this implies we're growing. */
	ecode = replace_data(tdb, &h, key, dbuf, off, old_room, off);
out:
	tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
	return tdb->last_error = ecode;
}

enum TDB_ERROR tdb_append(struct tdb_context *tdb,
			  struct tdb_data key, struct tdb_data dbuf)
{
	struct hash_info h;
	tdb_off_t off;
	struct tdb_used_record rec;
	tdb_len_t old_room = 0, old_dlen;
	unsigned char *newdata;
	struct tdb_data new_dbuf;
	enum TDB_ERROR ecode;

	if (tdb->flags & TDB_VERSION1) {
		if (tdb1_append(tdb, key, dbuf) == -1)
			return tdb->last_error;
		return TDB_SUCCESS;
	}

	off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
	if (TDB_OFF_IS_ERR(off)) {
		return tdb->last_error = TDB_OFF_TO_ERR(off);
	}

	if (off) {
		old_dlen = rec_data_length(&rec);
		old_room = old_dlen + rec_extra_padding(&rec);

		/* Fast path: can append in place. */
		if (rec_extra_padding(&rec) >= dbuf.dsize) {
			ecode = update_rec_hdr(tdb, off, key.dsize,
					       old_dlen + dbuf.dsize, &rec,
					       h.h);
			if (ecode != TDB_SUCCESS) {
				goto out;
			}

			off += sizeof(rec) + key.dsize + old_dlen;
			ecode = update_data(tdb, off, dbuf,
					    rec_extra_padding(&rec));
			goto out;
		}

		/* Slow path. */
		newdata = malloc(key.dsize + old_dlen + dbuf.dsize);
		if (!newdata) {
			ecode = tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
					   "tdb_append:"
					   " failed to allocate %zu bytes",
					   (size_t)(key.dsize + old_dlen
						    + dbuf.dsize));
			goto out;
		}
		ecode = tdb->tdb2.io->tread(tdb, off + sizeof(rec) + key.dsize,
					    newdata, old_dlen);
		if (ecode != TDB_SUCCESS) {
			goto out_free_newdata;
		}
		memcpy(newdata + old_dlen, dbuf.dptr, dbuf.dsize);
		new_dbuf.dptr = newdata;
		new_dbuf.dsize = old_dlen + dbuf.dsize;
	} else {
		newdata = NULL;
		new_dbuf = dbuf;
	}

	/* If they're using tdb_append(), it implies they're growing record. */
	ecode = replace_data(tdb, &h, key, new_dbuf, off, old_room, true);

out_free_newdata:
	free(newdata);
out:
	tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
	return tdb->last_error = ecode;
}

enum TDB_ERROR tdb_fetch(struct tdb_context *tdb, struct tdb_data key,
			 struct tdb_data *data)
{
	tdb_off_t off;
	struct tdb_used_record rec;
	struct hash_info h;
	enum TDB_ERROR ecode;

	if (tdb->flags & TDB_VERSION1)
		return tdb1_fetch(tdb, key, data);

	off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
	if (TDB_OFF_IS_ERR(off)) {
		return tdb->last_error = TDB_OFF_TO_ERR(off);
	}

	if (!off) {
		ecode = TDB_ERR_NOEXIST;
	} else {
		data->dsize = rec_data_length(&rec);
		data->dptr = tdb_alloc_read(tdb, off + sizeof(rec) + key.dsize,
					    data->dsize);
		if (TDB_PTR_IS_ERR(data->dptr)) {
			ecode = TDB_PTR_ERR(data->dptr);
		} else
			ecode = TDB_SUCCESS;
	}

	tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
	return tdb->last_error = ecode;
}

bool tdb_exists(struct tdb_context *tdb, TDB_DATA key)
{
	tdb_off_t off;
	struct tdb_used_record rec;
	struct hash_info h;

	if (tdb->flags & TDB_VERSION1) {
		return tdb1_exists(tdb, key);
	}

	off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
	if (TDB_OFF_IS_ERR(off)) {
		tdb->last_error = TDB_OFF_TO_ERR(off);
		return false;
	}
	tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);

	tdb->last_error = TDB_SUCCESS;
	return off ? true : false;
}

enum TDB_ERROR tdb_delete(struct tdb_context *tdb, struct tdb_data key)
{
	tdb_off_t off;
	struct tdb_used_record rec;
	struct hash_info h;
	enum TDB_ERROR ecode;

	if (tdb->flags & TDB_VERSION1) {
		if (tdb1_delete(tdb, key) == -1)
			return tdb->last_error;
		return TDB_SUCCESS;
	}

	off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
	if (TDB_OFF_IS_ERR(off)) {
		return tdb->last_error = TDB_OFF_TO_ERR(off);
	}

	if (!off) {
		ecode = TDB_ERR_NOEXIST;
		goto unlock;
	}

	ecode = delete_from_hash(tdb, &h);
	if (ecode != TDB_SUCCESS) {
		goto unlock;
	}

	/* Free the deleted entry. */
	tdb->stats.frees++;
	ecode = add_free_record(tdb, off,
				sizeof(struct tdb_used_record)
				+ rec_key_length(&rec)
				+ rec_data_length(&rec)
				+ rec_extra_padding(&rec),
				TDB_LOCK_WAIT, true);

	if (tdb->flags & TDB_SEQNUM)
		tdb_inc_seqnum(tdb);

unlock:
	tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
	return tdb->last_error = ecode;
}

unsigned int tdb_get_flags(struct tdb_context *tdb)
{
	return tdb->flags;
}

static bool inside_transaction(const struct tdb_context *tdb)
{
	if (tdb->flags & TDB_VERSION1)
		return tdb->tdb1.transaction != NULL;
	else
		return tdb->tdb2.transaction != NULL;
}

static bool readonly_changable(struct tdb_context *tdb, const char *caller)
{
	if (inside_transaction(tdb)) {
		tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
					     TDB_LOG_USE_ERROR,
					     "%s: can't change"
					     " TDB_RDONLY inside transaction",
					     caller);
		return false;
	}
	return true;
}

void tdb_add_flag(struct tdb_context *tdb, unsigned flag)
{
	if (tdb->flags & TDB_INTERNAL) {
		tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
					     TDB_LOG_USE_ERROR,
					     "tdb_add_flag: internal db");
		return;
	}
	switch (flag) {
	case TDB_NOLOCK:
		tdb->flags |= TDB_NOLOCK;
		break;
	case TDB_NOMMAP:
		tdb->flags |= TDB_NOMMAP;
		tdb_munmap(tdb->file);
		break;
	case TDB_NOSYNC:
		tdb->flags |= TDB_NOSYNC;
		break;
	case TDB_SEQNUM:
		tdb->flags |= TDB_SEQNUM;
		break;
	case TDB_ALLOW_NESTING:
		tdb->flags |= TDB_ALLOW_NESTING;
		break;
	case TDB_RDONLY:
		if (readonly_changable(tdb, "tdb_add_flag"))
			tdb->flags |= TDB_RDONLY;
		break;
	default:
		tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
					     TDB_LOG_USE_ERROR,
					     "tdb_add_flag: Unknown flag %u",
					     flag);
	}
}

void tdb_remove_flag(struct tdb_context *tdb, unsigned flag)
{
	if (tdb->flags & TDB_INTERNAL) {
		tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
					     TDB_LOG_USE_ERROR,
					     "tdb_remove_flag: internal db");
		return;
	}
	switch (flag) {
	case TDB_NOLOCK:
		tdb->flags &= ~TDB_NOLOCK;
		break;
	case TDB_NOMMAP:
		tdb->flags &= ~TDB_NOMMAP;
		tdb_mmap(tdb);
		break;
	case TDB_NOSYNC:
		tdb->flags &= ~TDB_NOSYNC;
		break;
	case TDB_SEQNUM:
		tdb->flags &= ~TDB_SEQNUM;
		break;
	case TDB_ALLOW_NESTING:
		tdb->flags &= ~TDB_ALLOW_NESTING;
		break;
	case TDB_RDONLY:
		if ((tdb->open_flags & O_ACCMODE) == O_RDONLY) {
			tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
						     TDB_LOG_USE_ERROR,
						     "tdb_remove_flag: can't"
						     " remove TDB_RDONLY on tdb"
						     " opened with O_RDONLY");
			break;
		}
		if (readonly_changable(tdb, "tdb_remove_flag"))
			tdb->flags &= ~TDB_RDONLY;
		break;
	default:
		tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
					     TDB_LOG_USE_ERROR,
					     "tdb_remove_flag: Unknown flag %u",
					     flag);
	}
}

const char *tdb_errorstr(enum TDB_ERROR ecode)
{
	/* Gcc warns if you miss a case in the switch, so use that. */
	switch (TDB_ERR_TO_OFF(ecode)) {
	case TDB_ERR_TO_OFF(TDB_SUCCESS): return "Success";
	case TDB_ERR_TO_OFF(TDB_ERR_CORRUPT): return "Corrupt database";
	case TDB_ERR_TO_OFF(TDB_ERR_IO): return "IO Error";
	case TDB_ERR_TO_OFF(TDB_ERR_LOCK): return "Locking error";
	case TDB_ERR_TO_OFF(TDB_ERR_OOM): return "Out of memory";
	case TDB_ERR_TO_OFF(TDB_ERR_EXISTS): return "Record exists";
	case TDB_ERR_TO_OFF(TDB_ERR_EINVAL): return "Invalid parameter";
	case TDB_ERR_TO_OFF(TDB_ERR_NOEXIST): return "Record does not exist";
	case TDB_ERR_TO_OFF(TDB_ERR_RDONLY): return "write not permitted";
	}
	return "Invalid error code";
}

enum TDB_ERROR tdb_error(struct tdb_context *tdb)
{
	return tdb->last_error;
}

enum TDB_ERROR COLD tdb_logerr(struct tdb_context *tdb,
			       enum TDB_ERROR ecode,
			       enum tdb_log_level level,
			       const char *fmt, ...)
{
	char *message;
	va_list ap;
	size_t len;
	/* tdb_open paths care about errno, so save it. */
	int saved_errno = errno;

	if (!tdb->log_fn)
		return ecode;

	va_start(ap, fmt);
	len = vasprintf(&message, fmt, ap);
	va_end(ap);

	if (len < 0) {
		tdb->log_fn(tdb, TDB_LOG_ERROR, TDB_ERR_OOM,
			    "out of memory formatting message:", tdb->log_data);
		tdb->log_fn(tdb, level, ecode, fmt, tdb->log_data);
	} else {
		tdb->log_fn(tdb, level, ecode, message, tdb->log_data);
		free(message);
	}
	errno = saved_errno;
	return ecode;
}

enum TDB_ERROR tdb_parse_record_(struct tdb_context *tdb,
				 TDB_DATA key,
				 enum TDB_ERROR (*parse)(TDB_DATA k,
							 TDB_DATA d,
							 void *data),
				 void *data)
{
	tdb_off_t off;
	struct tdb_used_record rec;
	struct hash_info h;
	enum TDB_ERROR ecode;

	if (tdb->flags & TDB_VERSION1) {
		return tdb->last_error = tdb1_parse_record(tdb, key, parse,
							   data);
	}

	off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
	if (TDB_OFF_IS_ERR(off)) {
		return tdb->last_error = TDB_OFF_TO_ERR(off);
	}

	if (!off) {
		ecode = TDB_ERR_NOEXIST;
	} else {
		const void *dptr;
		dptr = tdb_access_read(tdb, off + sizeof(rec) + key.dsize,
				       rec_data_length(&rec), false);
		if (TDB_PTR_IS_ERR(dptr)) {
			ecode = TDB_PTR_ERR(dptr);
		} else {
			TDB_DATA d = tdb_mkdata(dptr, rec_data_length(&rec));

			ecode = parse(key, d, data);
			tdb_access_release(tdb, dptr);
		}
	}

	tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
	return tdb->last_error = ecode;
}

const char *tdb_name(const struct tdb_context *tdb)
{
	return tdb->name;
}

int64_t tdb_get_seqnum(struct tdb_context *tdb)
{
	tdb_off_t off;

	if (tdb->flags & TDB_VERSION1) {
		tdb1_off_t val;
		tdb->last_error = TDB_SUCCESS;
		val = tdb1_get_seqnum(tdb);

		if (tdb->last_error != TDB_SUCCESS)
			return TDB_ERR_TO_OFF(tdb->last_error);
		else
			return val;
	}

	off = tdb_read_off(tdb, offsetof(struct tdb_header, seqnum));
	if (TDB_OFF_IS_ERR(off))
		tdb->last_error = TDB_OFF_TO_ERR(off);
	else
		tdb->last_error = TDB_SUCCESS;
	return off;
}


int tdb_fd(const struct tdb_context *tdb)
{
	return tdb->file->fd;
}

struct traverse_state {
	enum TDB_ERROR error;
	struct tdb_context *dest_db;
};

/*
  traverse function for repacking
 */
static int repack_traverse(struct tdb_context *tdb, TDB_DATA key, TDB_DATA data,
			   struct traverse_state *state)
{
	state->error = tdb_store(state->dest_db, key, data, TDB_INSERT);
	if (state->error != TDB_SUCCESS) {
		return -1;
	}
	return 0;
}

enum TDB_ERROR tdb_repack(struct tdb_context *tdb)
{
	struct tdb_context *tmp_db;
	struct traverse_state state;

	state.error = tdb_transaction_start(tdb);
	if (state.error != TDB_SUCCESS) {
		return state.error;
	}

	tmp_db = tdb_open("tmpdb", TDB_INTERNAL, O_RDWR|O_CREAT, 0, NULL);
	if (tmp_db == NULL) {
		state.error = tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
					 __location__
					 " Failed to create tmp_db");
		tdb_transaction_cancel(tdb);
		return tdb->last_error = state.error;
	}

	state.dest_db = tmp_db;
	if (tdb_traverse(tdb, repack_traverse, &state) < 0) {
		goto fail;
	}

	state.error = tdb_wipe_all(tdb);
	if (state.error != TDB_SUCCESS) {
		goto fail;
	}

	state.dest_db = tdb;
	if (tdb_traverse(tmp_db, repack_traverse, &state) < 0) {
		goto fail;
	}

	tdb_close(tmp_db);
	return tdb_transaction_commit(tdb);

fail:
	tdb_transaction_cancel(tdb);
	tdb_close(tmp_db);
	return state.error;
}