statx struct's stx_size pointer compatibility with uint64_t/size_t

[Florian Weimer]

* David Howells:

> Florian Weimer <fweimer@redhat.com> wrote:
>
>> I do not know why the kernel definition of __u64 does not follow that of
>> uint64_t in <stdint.h> (or why we even have that __u64 type)
>
> Do Linux's __uXX types predate stdint.h by a few years?

Yes, certainly __u64 predates widespread compiler support for long long.

>> and whether the kernel definition can be changed at this point
>
> Changing it would require an awful lot of printf format overhaul.

Yes, we probably should add __glibc_u64 etc. types with the same
definition as in the kernel.  For struct statx, it does not matter, but
<linux/types.h> is not namespace-clean, and that may be a problem in
other contexts.  Using __glibc_u64 etc. types consistently seems
preferable.

Thanks,
Florian