On Tue, Feb 19, 2013 at 5:04 PM, Florian Weimer <fweimer(a)redhat.com> wrote:
On 02/19/2013 04:32 PM, Jakub Jelinek wrote:
>
> On Tue, Feb 19, 2013 at 09:22:55AM -0600, Eric Sandeen wrote:
>>>
>>> (3) For my code that uses st_ino, I need to ensure this is never
>>> assigned to a 32 bit integer (eg. 'int', 'int32_t',
'long' on 32 bit,
>>> etc.)?
>>
>>
>> To be safe I'd use it in an u64 type, I guess. The *internal* kernel stat
>> structure uses u64:
>
> That would be wrong. To store st_ino values, you should be using the ino_t
> type, like for file sizes/offsets (st_size, seeking, etc.) you should be
> using off_t. Both of these types depend on _FILE_OFFSET_BITS macro.
You can't use ino_t and off_t in public header files because of that
_FILE_OFFSET_BITS dependency. At least in such header files, using explicit
64-bit types (uint64_t, presumably) is the way to go.
Admittedly, this has a certain yuck factor, but I don't see a way around
that.
To be safe and portable, use uintmax_t. It's still not quite pretty,
but at least the type is portable, has a fixed ABI, and there are
printf specifiers for uintmax_t (unlike ino_t or ino64_t).
Mirek