[NFS-Ganesha-Devel] O_TRUNC in open2

Hello, Can anyone explain how O_TRUNC is handled (open2)? When I try to open an existing file with this flag, the FSAL_O_TRUNC in openflags is not enabled in my FSAL open2 fct. While capturing with tcpdump, the NFS client actually sends a OPEN then SETATTR with size = 0 but not ctime. By looking at an example in open_by_handle, if IIUC if the flag O_TRUNC is there, we refresh the attrs by calling getattrs to attrs_out, I do not understand that, why it does that instead of calling setattrs ? Thank you. Viet