On Thu, Feb 27, 2020 at 3:30 PM Jan Kara <jack@xxxxxxx> wrote:
>
> On Thu 27-02-20 14:12:30, Amir Goldstein wrote:
> > >
> > > > struct fanotify_fh_name {
> > > > union {
> > > > struct {
> > > > u8 fh_type;
> > > > u8 fh_len;
> > > > u8 name_len;
> > > > u32 hash;
> > > > };
> > > > u64 hash_len;
> > > > };
> > > > union {
> > > > unsigned char fh[FANOTIFY_INLINE_FH_LEN];
> > > > unsigned char *ext_fh;
> > > > };
> > > > char name[0];
> > > > };
> > >
> > > So based on the above I wouldn't add just name hash to fanotify_fh_name at
> > > this point...
> > >
> >
> > OK. but what do you think about tying name with fh as above?
> > At least name_len gets to use the hole this way.
>
> Is saving that one byte for name_len really worth the packing? If anything,
> I'd rather do the fanotity_fh padding optimization I outlined in another
> email. That would save one long without any packing and the following u8
> name_len would get packed tightly after the fanotify_fh by the compiler.
>
OK. I will try that and the non-inherited variant of perm/name event struct
and see how it looks like.
Thanks,
Amir.
