/* The transaction code uses this to remove all locks. */
void tdb_release_transaction_locks(struct tdb_context *tdb)
{
unsigned int i, active = 0;
if (tdb->allrecord_lock.count != 0) {
tdb_allrecord_unlock(tdb, tdb->allrecord_lock.ltype, false);
tdb->allrecord_lock.count = 0;
}
for (i=0;i<tdb->num_lockrecs;i++) {
struct tdb_lock_type *lck = &tdb->lockrecs[i];
/* Don't release the active lock! Copy it to first entry. */
if (lck->off == ACTIVE_LOCK) {
tdb->lockrecs[active++] = *lck;
} else {
tdb_brunlock(tdb, lck->ltype, lck->off, 1);
}
}
tdb->num_lockrecs = active;
}
enum TDB_ERROR tdb_wipe_all(struct tdb_context *tdb)
{
enum TDB_ERROR ecode;
int64_t count;
if (tdb->flags & TDB_VERSION1) {
if (tdb1_wipe_all(tdb) == -1)
return tdb->last_error;
return TDB_SUCCESS;
}
ecode = tdb_allrecord_lock(tdb, F_WRLCK, TDB_LOCK_WAIT, false);
if (ecode != TDB_SUCCESS)
return tdb->last_error = ecode;
/* FIXME: Be smarter. */
count = tdb_traverse(tdb, wipe_one, &ecode);
if (count < 0)
ecode = TDB_OFF_TO_ERR(count);
tdb_allrecord_unlock(tdb, F_WRLCK);
return tdb->last_error = ecode;
}
/* unlock entire database with read lock */
_PUBLIC_ int tdb_unlockall_read(struct tdb_context *tdb)
{
tdb_trace(tdb, "tdb_unlockall_read");
return tdb_allrecord_unlock(tdb, F_RDLCK, false);
}
/* unlock entire database with write lock - unmark only */
_PUBLIC_ int tdb_lockall_unmark(struct tdb_context *tdb)
{
tdb_trace(tdb, "tdb_lockall_unmark");
return tdb_allrecord_unlock(tdb, F_WRLCK, true);
}
/* lock/unlock entire database. It can only be upgradable if you have some
* other way of guaranteeing exclusivity (ie. transaction write lock).
* We do the locking gradually to avoid being starved by smaller locks. */
int tdb_allrecord_lock(struct tdb_context *tdb, int ltype,
enum tdb_lock_flags flags, bool upgradable)
{
int ret;
switch (tdb_allrecord_check(tdb, ltype, flags, upgradable)) {
case -1:
return -1;
case 0:
return 0;
}
/* We cover two kinds of locks:
* 1) Normal chain locks. Taken for almost all operations.
* 2) Individual records locks. Taken after normal or free
* chain locks.
*
* It is (1) which cause the starvation problem, so we're only
* gradual for that. */
if (tdb_have_mutexes(tdb)) {
ret = tdb_mutex_allrecord_lock(tdb, ltype, flags);
} else {
ret = tdb_chainlock_gradual(tdb, ltype, flags, FREELIST_TOP,
tdb->hash_size * 4);
}
if (ret == -1) {
return -1;
}
/* Grab individual record locks. */
if (tdb_brlock(tdb, ltype, lock_offset(tdb->hash_size), 0,
flags) == -1) {
if (tdb_have_mutexes(tdb)) {
tdb_mutex_allrecord_unlock(tdb);
} else {
tdb_brunlock(tdb, ltype, FREELIST_TOP,
tdb->hash_size * 4);
}
return -1;
}
tdb->allrecord_lock.count = 1;
/* If it's upgradable, it's actually exclusive so we can treat
* it as a write lock. */
tdb->allrecord_lock.ltype = upgradable ? F_WRLCK : ltype;
tdb->allrecord_lock.off = upgradable;
if (tdb_needs_recovery(tdb)) {
bool mark = flags & TDB_LOCK_MARK_ONLY;
tdb_allrecord_unlock(tdb, ltype, mark);
if (mark) {
tdb->ecode = TDB_ERR_LOCK;
TDB_LOG((tdb, TDB_DEBUG_ERROR,
"tdb_lockall_mark cannot do recovery\n"));
return -1;
}
if (tdb_lock_and_recover(tdb) == -1) {
return -1;
}
return tdb_allrecord_lock(tdb, ltype, flags, upgradable);
}
return 0;
}
