static bool tdb_check_header(struct tdb_context *tdb, tdb_off_t *recovery)
{
struct tdb_header hdr;
+ uint32_t h1, h2;
- if (tdb->methods->tdb_read(tdb, 0, &hdr, sizeof(hdr), DOCONV()) == -1)
+ if (tdb->methods->tdb_read(tdb, 0, &hdr, sizeof(hdr), 0) == -1)
return false;
if (strcmp(hdr.magic_food, TDB_MAGIC_FOOD) != 0)
goto corrupt;
if (hdr.version != TDB_VERSION)
goto corrupt;
- if (hdr.rwlocks != 0)
+ if (hdr.rwlocks != 0 && hdr.rwlocks != TDB_HASH_RWLOCK_MAGIC)
+ goto corrupt;
+
+ tdb_header_hash(tdb, &h1, &h2);
+ if (hdr.magic1_hash && hdr.magic2_hash &&
+ (hdr.magic1_hash != h1 || hdr.magic2_hash != h2))
goto corrupt;
if (hdr.hash_size == 0)
return true;
}
+/* Slow, but should be very rare. */
+size_t tdb_dead_space(struct tdb_context *tdb, tdb_off_t off)
+{
+ size_t len;
+
+ for (len = 0; off + len < tdb->map_size; len++) {
+ char c;
+ if (tdb->methods->tdb_read(tdb, off, &c, 1, 0))
+ return 0;
+ if (c != 0 && c != 0x42)
+ break;
+ }
+ return len;
+}
+
int tdb_check(struct tdb_context *tdb,
int (*check)(TDB_DATA key, TDB_DATA data, void *private_data),
void *private_data)
tdb_off_t off, recovery_start;
struct tdb_record rec;
bool found_recovery = false;
-
- if (tdb_lockall(tdb) == -1)
- return -1;
+ tdb_len_t dead;
+ bool locked;
+
+ /* Read-only databases use no locking at all: it's best-effort.
+ * We may have a write lock already, so skip that case too. */
+ if (tdb->read_only || tdb->allrecord_lock.count != 0) {
+ locked = false;
+ } else {
+ if (tdb_lockall_read(tdb) == -1)
+ return -1;
+ locked = true;
+ }
/* Make sure we know true size of the underlying file. */
tdb->methods->tdb_oob(tdb, tdb->map_size + 1, 1);
if (!tdb_check_free_record(tdb, off, &rec, hashes))
goto free;
break;
- case TDB_RECOVERY_MAGIC:
+ /* If we crash after ftruncate, we can get zeroes or fill. */
case TDB_RECOVERY_INVALID_MAGIC:
+ case 0x42424242:
+ if (recovery_start == off) {
+ found_recovery = true;
+ break;
+ }
+ dead = tdb_dead_space(tdb, off);
+ if (dead < sizeof(rec))
+ goto corrupt;
+
+ TDB_LOG((tdb, TDB_DEBUG_ERROR,
+ "Dead space at %d-%d (of %u)\n",
+ off, off + dead, tdb->map_size));
+ rec.rec_len = dead - sizeof(rec);
+ break;
+ case TDB_RECOVERY_MAGIC:
if (recovery_start != off) {
TDB_LOG((tdb, TDB_DEBUG_ERROR,
"Unexpected recovery record at offset %d\n",
}
found_recovery = true;
break;
- default:
+ default: ;
+ corrupt:
tdb->ecode = TDB_ERR_CORRUPT;
TDB_LOG((tdb, TDB_DEBUG_ERROR,
"Bad magic 0x%x at offset %d\n",
/* We must have found recovery area if there was one. */
if (recovery_start != 0 && !found_recovery) {
TDB_LOG((tdb, TDB_DEBUG_ERROR,
- "Expected %s recovery area, got %s\n",
- recovery_start ? "a" : "no",
- found_recovery ? "one" : "none"));
+ "Expected a recovery area at %u\n",
+ recovery_start));
goto free;
}
free(hashes);
- tdb_unlockall(tdb);
+ if (locked) {
+ tdb_unlockall_read(tdb);
+ }
return 0;
free:
free(hashes);
unlock:
- tdb_unlockall(tdb);
+ if (locked) {
+ tdb_unlockall_read(tdb);
+ }
return -1;
}