/* all contexts, to ensure no double-opens (fcntl locks don't nest!) */
static struct tdb_context *tdbs = NULL;
-
-/* This is based on the hash algorithm from gdbm */
-static unsigned int default_tdb_hash(TDB_DATA *key)
+/* We use two hashes to double-check they're using the right hash function. */
+void tdb_header_hash(struct tdb_context *tdb,
+ uint32_t *magic1_hash, uint32_t *magic2_hash)
{
- uint32_t value; /* Used to compute the hash value. */
- uint32_t i; /* Used to cycle through random values. */
+ TDB_DATA hash_key;
+ uint32_t tdb_magic = TDB_MAGIC;
- /* Set the initial value from the key size. */
- for (value = 0x238F13AF * key->dsize, i=0; i < key->dsize; i++)
- value = (value + (key->dptr[i] << (i*5 % 24)));
+ hash_key.dptr = (unsigned char *)TDB_MAGIC_FOOD;
+ hash_key.dsize = sizeof(TDB_MAGIC_FOOD);
+ *magic1_hash = tdb->hash_fn(&hash_key);
- return (1103515243 * value + 12345);
-}
+ hash_key.dptr = CONVERT(tdb_magic);
+ hash_key.dsize = sizeof(tdb_magic);
+ *magic2_hash = tdb->hash_fn(&hash_key);
+ /* Make sure at least one hash is non-zero! */
+ if (*magic1_hash == 0 && *magic2_hash == 0)
+ *magic1_hash = 1;
+}
/* initialise a new database with a specified hash size */
static int tdb_new_database(struct tdb_context *tdb, int hash_size)
/* Fill in the header */
newdb->version = TDB_VERSION;
newdb->hash_size = hash_size;
+
+ tdb_header_hash(tdb, &newdb->magic1_hash, &newdb->magic2_hash);
+
+ /* Make sure older tdbs (which don't check the magic hash fields)
+ * will refuse to open this TDB. */
+ if (tdb->flags & TDB_INCOMPATIBLE_HASH)
+ newdb->rwlocks = TDB_HASH_RWLOCK_MAGIC;
+
if (tdb->flags & TDB_INTERNAL) {
tdb->map_size = size;
tdb->map_ptr = (char *)newdb;
}
/* a default logging function */
-static void null_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...) PRINTF_ATTRIBUTE(3, 4);
+static void null_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...) PRINTF_FMT(3, 4);
static void null_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...)
{
}
+static bool check_header_hash(struct tdb_context *tdb,
+ bool default_hash, uint32_t *m1, uint32_t *m2)
+{
+ tdb_header_hash(tdb, m1, m2);
+ if (tdb->header.magic1_hash == *m1 &&
+ tdb->header.magic2_hash == *m2) {
+ return true;
+ }
+
+ /* If they explicitly set a hash, always respect it. */
+ if (!default_hash)
+ return false;
+
+ /* Otherwise, try the other inbuilt hash. */
+ if (tdb->hash_fn == tdb_old_hash)
+ tdb->hash_fn = tdb_jenkins_hash;
+ else
+ tdb->hash_fn = tdb_old_hash;
+ return check_header_hash(tdb, false, m1, m2);
+}
struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
int open_flags, mode_t mode,
unsigned char *vp;
uint32_t vertest;
unsigned v;
+ const char *hash_alg;
+ uint32_t magic1, magic2;
if (!(tdb = (struct tdb_context *)calloc(1, sizeof *tdb))) {
/* Can't log this */
tdb->log.log_fn = null_log_fn;
tdb->log.log_private = NULL;
}
- tdb->hash_fn = hash_fn ? hash_fn : default_tdb_hash;
+
+ if (hash_fn) {
+ tdb->hash_fn = hash_fn;
+ hash_alg = "the user defined";
+ } else {
+ /* This controls what we use when creating a tdb. */
+ if (tdb->flags & TDB_INCOMPATIBLE_HASH) {
+ tdb->hash_fn = tdb_jenkins_hash;
+ } else {
+ tdb->hash_fn = tdb_old_hash;
+ }
+ hash_alg = "either default";
+ }
/* cache the page size */
tdb->page_size = getpagesize();
fcntl(tdb->fd, F_SETFD, v | FD_CLOEXEC);
/* ensure there is only one process initialising at once */
- if (tdb->methods->brlock(tdb, F_WRLCK, OPEN_LOCK, 1, TDB_LOCK_WAIT) == -1) {
+ if (tdb_nest_lock(tdb, OPEN_LOCK, F_WRLCK, TDB_LOCK_WAIT) == -1) {
TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to get open lock on %s: %s\n",
name, strerror(errno)));
goto fail; /* errno set by tdb_brlock */
/* we need to zero database if we are the only one with it open */
if ((tdb_flags & TDB_CLEAR_IF_FIRST) &&
(!tdb->read_only) &&
- (locked = (tdb->methods->brlock(tdb, F_WRLCK, ACTIVE_LOCK, 1, TDB_LOCK_NOWAIT|TDB_LOCK_PROBE) == 0))) {
+ (locked = (tdb_nest_lock(tdb, ACTIVE_LOCK, F_WRLCK, TDB_LOCK_NOWAIT|TDB_LOCK_PROBE) == 0))) {
open_flags |= O_CREAT;
if (ftruncate(tdb->fd, 0) == -1) {
TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
if (fstat(tdb->fd, &st) == -1)
goto fail;
- if (tdb->header.rwlocks != 0) {
+ if (tdb->header.rwlocks != 0 &&
+ tdb->header.rwlocks != TDB_HASH_RWLOCK_MAGIC) {
TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: spinlocks no longer supported\n"));
goto fail;
}
+ if ((tdb->header.magic1_hash == 0) && (tdb->header.magic2_hash == 0)) {
+ /* older TDB without magic hash references */
+ tdb->hash_fn = tdb_old_hash;
+ } else if (!check_header_hash(tdb, !hash_fn, &magic1, &magic2)) {
+ TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
+ "%s was not created with %s hash function we are using\n"
+ "magic1_hash[0x%08X %s 0x%08X] "
+ "magic2_hash[0x%08X %s 0x%08X]\n",
+ name, hash_alg,
+ tdb->header.magic1_hash,
+ (tdb->header.magic1_hash == magic1) ? "==" : "!=",
+ magic1,
+ tdb->header.magic2_hash,
+ (tdb->header.magic2_hash == magic2) ? "==" : "!=",
+ magic2));
+ errno = EINVAL;
+ goto fail;
+ }
+
/* Is it already in the open list? If so, fail. */
if (tdb_already_open(st.st_dev, st.st_ino)) {
TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: "
tdb->inode = st.st_ino;
tdb_mmap(tdb);
if (locked) {
- if (tdb->methods->brunlock(tdb, F_WRLCK, ACTIVE_LOCK, 1) == -1) {
+ if (tdb_nest_unlock(tdb, ACTIVE_LOCK, F_WRLCK, false) == -1) {
TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: "
"failed to take ACTIVE_LOCK on %s: %s\n",
name, strerror(errno)));
if (tdb_flags & TDB_CLEAR_IF_FIRST) {
/* leave this lock in place to indicate it's in use */
- if (tdb->methods->brlock(tdb, F_RDLCK, ACTIVE_LOCK, 1, TDB_LOCK_WAIT) == -1)
+ if (tdb_nest_lock(tdb, ACTIVE_LOCK, F_RDLCK, TDB_LOCK_WAIT) == -1) {
goto fail;
+ }
}
/* if needed, run recovery */
/* Internal (memory-only) databases skip all the code above to
* do with disk files, and resume here by releasing their
* open lock and hooking into the active list. */
- if (tdb->methods->brunlock(tdb, F_WRLCK, OPEN_LOCK, 1) == -1)
+ if (tdb_nest_unlock(tdb, OPEN_LOCK, F_WRLCK, false) == -1) {
goto fail;
+ }
tdb->next = tdbs;
tdbs = tdb;
return tdb;
if (tdb->fd != -1)
if (close(tdb->fd) != 0)
TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to close tdb->fd on error!\n"));
+ SAFE_FREE(tdb->lockrecs);
SAFE_FREE(tdb);
errno = save_errno;
return NULL;
return 0; /* Nothing to do. */
}
- if (tdb->num_locks != 0 || tdb->global_lock.count) {
+ if (tdb_have_extra_locks(tdb)) {
TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_reopen: reopen not allowed with locks held\n"));
goto fail;
}
}
tdb_mmap(tdb);
- if (active_lock &&
- (tdb->methods->brlock(tdb, F_RDLCK, ACTIVE_LOCK, 1, TDB_LOCK_WAIT) == -1)) {
+ /* We may still think we hold the active lock. */
+ tdb->num_lockrecs = 0;
+ SAFE_FREE(tdb->lockrecs);
+
+ if (active_lock && tdb_nest_lock(tdb, ACTIVE_LOCK, F_RDLCK, TDB_LOCK_WAIT) == -1) {
TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: failed to obtain active lock\n"));
goto fail;
}
projects / ccan / blobdiff