IF NEW.parent_id THEN
    SELECT uf.level + 1, uf.tree_id
      INTO _new_level, _new_tree_id
    FROM fh_user_file uf
    WHERE id = NEW.parent_id;

    SET NEW.level = _new_level;
    SET NEW.tree_id = _new_tree_id;
  ELSE
    SET NEW.level = 0;
    SET NEW.tree_id = (SELECT MAX(tree_id)+1 FROM fh_user_file);
  END IF;

------------------------
LATEST DETECTED DEADLOCK
------------------------
130924  7:00:07
*** (1) TRANSACTION:
TRANSACTION B52E35C8, ACTIVE 1 sec inserting
mysql tables in use 9, locked 9
LOCK WAIT 8 lock struct(s), heap size 1248, 5 row lock(s), undo log entries 2
MySQL thread id 3468696, OS thread handle 0x7ff4e66ed700, query id 87285070 localhost 
INSERT INTO `fh_user_file`[вырезано]
*** (1) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 0 page no 961034 n bits 408 index `IX_user_file_tree_id_level` of table `fh_user_file` trx id B52E35C8 lock_mode X insert intention waiting
Record lock, heap no 1 PHYSICAL RECORD: n_fields 1; compact format; info bits 0
 0: len 8; hex 73757072656d756d; asc supremum;;

*** (2) TRANSACTION:
TRANSACTION B52E33E8, ACTIVE 2 sec inserting
mysql tables in use 9, locked 9
9 lock struct(s), heap size 1248, 6 row lock(s), undo log entries 2
MySQL thread id 3468641, OS thread handle 0x7ff4e71d6700, query id 87284027 localhost 
INSERT INTO `fh_user_file` [вырезано]
*** (2) HOLDS THE LOCK(S):
RECORD LOCKS space id 0 page no 961034 n bits 408 index `IX_user_file_tree_id_level` of table `fh_user_file` trx id B52E33E8 lock mode S
Record lock, heap no 1 PHYSICAL RECORD: n_fields 1; compact format; info bits 0
 0: len 8; hex 73757072656d756d; asc supremum;;

Record lock, heap no 336 PHYSICAL RECORD: n_fields 3; compact format; info bits 0
 0: len 4; hex 002418b7; asc  $  ;;
 1: len 1; hex 00; asc  ;;
 2: len 13; hex 35323431333836313163303736; asc 524138611c076;;

*** (2) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 0 page no 961034 n bits 408 index `IX_user_file_tree_id_level` of table `fh_user_file` trx id B52E33E8 lock_mode X insert intention waiting
Record lock, heap no 1 PHYSICAL RECORD: n_fields 1; compact format; info bits 0
 0: len 8; hex 73757072656d756d; asc supremum;;

  IF GET_LOCK("Lock_insert_user_file", 60) THEN
    IF NEW.parent_id THEN
      SELECT uf.level + 1, uf.tree_id
        INTO _new_level, _new_tree_id
      FROM fh_user_file uf
      WHERE id = NEW.parent_id;

      SET NEW.level = _new_level;
      SET NEW.tree_id = _new_tree_id;
    ELSE
      SET NEW.level = 0;
      SET NEW.tree_id = (SELECT value FROM fh_settings WHERE param = "user_file_tree_max_id");
      UPDATE fh_settings SET value = value + 1 WHERE param = "user_file_tree_max_id";
    END IF;
  END IF;

  SET lock_result = RELEASE_LOCK("Lock_insert_user_file");

  IF NEW.parent_id THEN
    SELECT uf.level + 1, uf.tree_id
      INTO _new_level, _new_tree_id
    FROM fh_user_file uf
    WHERE id = NEW.parent_id;

    SET NEW.level = _new_level;
    SET NEW.tree_id = _new_tree_id;
  ELSE
    IF GET_LOCK("Lock_insert_user_file", 60) THEN
      SET NEW.level = 0;
      SET NEW.tree_id = (SELECT value FROM fh_settings WHERE param = "user_file_tree_max_id");
      UPDATE fh_settings SET value = value + 1 WHERE param = "user_file_tree_max_id";
      SET lock_result = RELEASE_LOCK("Lock_insert_user_file");
    END IF;
  END IF;