/*
a write style traverse - needs to get the transaction lock to
prevent deadlocks
WARNING: The data buffer given to the callback fn does NOT meet the
alignment guarantees malloc gives you.
*/
_PUBLIC_ int tdb_traverse(struct tdb_context *tdb,
tdb_traverse_func fn, void *private_data)
{
struct tdb_traverse_lock tl = { NULL, 0, 0, F_WRLCK };
enum tdb_lock_flags lock_flags;
int ret;
if (tdb->read_only || tdb->traverse_read) {
return tdb_traverse_read(tdb, fn, private_data);
}
lock_flags = TDB_LOCK_WAIT;
if (tdb->allrecord_lock.count != 0) {
/*
* This avoids a deadlock between tdb_lockall() and
* tdb_traverse(). See
* https://bugzilla.samba.org/show_bug.cgi?id=11381
*/
lock_flags = TDB_LOCK_NOWAIT;
}
if (tdb_transaction_lock(tdb, F_WRLCK, lock_flags)) {
return -1;
}
tdb->traverse_write++;
tdb_trace(tdb, "tdb_traverse_start");
ret = tdb_traverse_internal(tdb, fn, private_data, &tl);
tdb->traverse_write--;
tdb_transaction_unlock(tdb, F_WRLCK);
return ret;
}
/*
a write style traverse - needs to get the transaction lock to
prevent deadlocks
WARNING: The data buffer given to the callback fn does NOT meet the
alignment restrictions malloc gives you.
*/
int tdb_traverse(struct tdb_context *tdb,
tdb_traverse_func fn, void *private_data)
{
struct tdb_traverse_lock tl = { NULL, 0, 0, F_WRLCK };
int ret;
bool in_transaction = (tdb->transaction != NULL);
if (tdb->read_only || tdb->traverse_read) {
return tdb_traverse_read(tdb, fn, private_data);
}
if (!in_transaction) {
if (tdb_transaction_lock(tdb, F_WRLCK)) {
return -1;
}
}
tdb->traverse_write++;
ret = tdb_traverse_internal(tdb, fn, private_data, &tl);
tdb->traverse_write--;
if (!in_transaction) {
tdb_transaction_unlock(tdb);
}
return ret;
}
/*
a write style traverse - temporarily marks the db read only
*/
int tdb_traverse_read(struct tdb_context *tdb,
tdb_traverse_func fn, void *private_data)
{
struct tdb_traverse_lock tl = { NULL, 0, 0, F_RDLCK };
int ret;
bool in_transaction = (tdb->transaction != NULL);
/* we need to get a read lock on the transaction lock here to
cope with the lock ordering semantics of solaris10 */
if (!in_transaction) {
if (tdb_transaction_lock(tdb, F_RDLCK)) {
return -1;
}
}
tdb->traverse_read++;
ret = tdb_traverse_internal(tdb, fn, private_data, &tl);
tdb->traverse_read--;
if (!in_transaction) {
tdb_transaction_unlock(tdb);
}
return ret;
}
/*
a read style traverse - temporarily marks the db read only
*/
_PUBLIC_ int tdb_traverse_read(struct tdb_context *tdb,
tdb_traverse_func fn, void *private_data)
{
struct tdb_traverse_lock tl = { NULL, 0, 0, F_RDLCK };
int ret;
/* we need to get a read lock on the transaction lock here to
cope with the lock ordering semantics of solaris10 */
if (tdb_transaction_lock(tdb, F_RDLCK, TDB_LOCK_WAIT)) {
return -1;
}
tdb->traverse_read++;
tdb_trace(tdb, "tdb_traverse_read_start");
ret = tdb_traverse_internal(tdb, fn, private_data, &tl);
tdb->traverse_read--;
tdb_transaction_unlock(tdb, F_RDLCK);
return ret;
}
/*
a write style traverse - needs to get the transaction lock to
prevent deadlocks
WARNING: The data buffer given to the callback fn does NOT meet the
alignment guarantees malloc gives you.
*/
_PUBLIC_ int tdb_traverse(struct tdb_context *tdb,
tdb_traverse_func fn, void *private_data)
{
struct tdb_traverse_lock tl = { NULL, 0, 0, F_WRLCK };
int ret;
if (tdb->read_only || tdb->traverse_read) {
return tdb_traverse_read(tdb, fn, private_data);
}
if (tdb_transaction_lock(tdb, F_WRLCK, TDB_LOCK_WAIT)) {
return -1;
}
tdb->traverse_write++;
tdb_trace(tdb, "tdb_traverse_start");
ret = tdb_traverse_internal(tdb, fn, private_data, &tl);
tdb->traverse_write--;
tdb_transaction_unlock(tdb, F_WRLCK);
return ret;
}
_PUBLIC_ int tdb_transaction_write_lock_mark(struct tdb_context *tdb)
{
return tdb_transaction_lock(tdb, F_WRLCK, TDB_LOCK_MARK_ONLY);
}
