Hi. In: https://git.postgresql.org/cgit/postgresql.git/tree/contrib/pg_freespacemap/pg_freespacemap.c
rel = relation_open(relid, AccessShareLock); if (blkno < 0 || blkno > MaxBlockNumber) ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("invalid block number"))); -------------------- should it first check input arguments, then relation_open? Does ereport automatically unlock the relation?