Re: extattr_set_*() return type

On Wed, Dec 21, 2011 at 10:31:11AM -0500, John Baldwin wrote:
> On Tuesday, December 20, 2011 5:18:58 pm mdf_at_freebsd.org wrote:
> > On Tue, Dec 20, 2011 at 1:49 PM, John Baldwin <jhb_at_freebsd.org> wrote:
> > > Hmm, if these functions are expected to operate like 'write(2)' and are
> > > supposed to return the number of bytes written, shouldn't their return value
> > > be 'ssize_t' instead of 'int'?  It looks like the system calls themselves
> > > already do the right thing in setting td_retval[] (they assign a ssize_t to it
> > > and td_retval[0] can hold a ssize_t on all of our current platforms).  It
> > > would seem that the only change would be to the header and probably
> > > syscalls.master.  I guess this would require a symver bump to fix though.
> > 
> > An extended attribute larger than 2GB is a programming abuse, though.
> > Technically int may not be 32 bits but it is on all supported
> > platforms now.
> 
> Today it is an abuse.  In the 90's a 64-bit off_t was considered an abuse by
> some. :)
> 
> The type should match the documented behavior.  On OS X the set operation
> doesn't return a size but instead returns a simple success/failure (0 or -1)
> for which an int is appropriate.  However, the FreeBSD API documents that it
> operates like write and consumes the buffer.   Note that the size of the
> buffer passed to the 'set' and 'get' operations is a size_t, not an int, and
> the 'get' operations already return a ssize_t, not an int.

Note that read(2)/write(2) do return int. I still have WIP patch to fix
this, but after some conversations with Bruce I am not sure it is worth
finishing.