VSTAFS_START_DATA
size = FILE_INFO->len-VSTAFS_START_DATA;
if (filepos < a[0].a_len * 512 - VSTAFS_START_DATA)
offset = filepos + VSTAFS_START_DATA;
ext_size = a[0].a_len * 512 - VSTAFS_START_DATA;
offset = VSTAFS_START_DATA;