RE: [PATCH v1 1/4] transport-helper: use xread instead of read

["Randall S. Becker" <rsbecker@nexbridge.com>]

On December 28, 2018 15:11,  Junio C Hamano wrote:
> randall.s.becker@rogers.com writes:
> 
> > From: "Randall S. Becker" <rsbecker@nexbridge.com>
> >
> > This fix was needed on HPE NonStop NSE and NSX where SSIZE_MAX is less
> > than BUFFERSIZE resulting in EINVAL. The call to read in
> > transport-helper.c was the only place outside of wrapper.c where it is
used
> instead of xread.
> >
> > Signed-off-by: Randall S. Becker <rsbecker@nexbridge.com>
> > ---
> >  transport-helper.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/transport-helper.c b/transport-helper.c index
> > bf225c698f..a290695a12 100644
> > --- a/transport-helper.c
> > +++ b/transport-helper.c
> > @@ -1225,7 +1225,7 @@ static int udt_do_read(struct
> unidirectional_transfer *t)
> >  		return 0;	/* No space for more. */
> >
> >  	transfer_debug("%s is readable", t->src_name);
> > -	bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
> > +	bytes = xread(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
> >  	if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
> >  		errno != EINTR) {
> >  		error_errno(_("read(%s) failed"), t->src_name);
> 
> As Peff pointed out in the earlier round of the same patch, replacing
read()
> with xread() here will affect what errno's can be possible after the
function
> returns.  The checks affected by this change must also be updated, either
in
> the same patch, or a follow-up patch in the same series.  Otherwise we
> _will_ forget to clean them up.

If I read the xread code correctly, the change would be to leave EINTR and
remove the other two conditions. Correct?