* Juan Quintela (quint...@redhat.com) wrote:
> "Dr. David Alan Gilbert (git)" <dgilb...@redhat.com> wrote:
> > From: "Dr. David Alan Gilbert" <dgilb...@redhat.com>
> >
> > The destination sets the fd to non-blocking on incoming migrations;
> > this also affects the return path from the destination, and thus we
> > need to make sure we can safely write to the return path.
> >
> > Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
>
> Reviewed-by: Juan Quintela <quint...@redhat.com>
Thanks,
> > migration/qemu-file-unix.c | 41 ++++++++++++++++++++++++++++++++++++-----
> > 1 file changed, 36 insertions(+), 5 deletions(-)
> >
> > diff --git a/migration/qemu-file-unix.c b/migration/qemu-file-unix.c
> > index 561621e..b6c55ab 100644
> > --- a/migration/qemu-file-unix.c
> > +++ b/migration/qemu-file-unix.c
> > @@ -39,12 +39,43 @@ static ssize_t socket_writev_buffer(void *opaque,
> > struct iovec *iov, int iovcnt,
> > QEMUFileSocket *s = opaque;
> > ssize_t len;
> > ssize_t size = iov_size(iov, iovcnt);
> > + ssize_t offset = 0;
> > + int err;
> >
> > - len = iov_send(s->fd, iov, iovcnt, 0, size);
> > - if (len < size) {
> > - len = -socket_error();
> > - }
> > - return len;
> > + while (size > 0) {
> > + len = iov_send(s->fd, iov, iovcnt, offset, size);
> > +
> > + if (len > 0) {
> > + size -= len;
> > + offset += len;
> > + }
>
> ion_send() can return -1 on error
>
> This looks a "hacky way" to look for it, althoght my understanding is
> that it is correct, so the review-by
I have to check the socket_error in two cases, one where
len == -1 , and the other where it's only sent some of the data.
Given I have to do it in both cases it doesn't seme worth explicitly
checking for the -1.
Dave
> > +
> > + if (size > 0) {
> > + err = socket_error();
> > +
> > + if (err != EAGAIN && err != EWOULDBLOCK) {
> > + error_report("socket_writev_buffer: Got err=%d for
> > (%zd/%zd)",
> > + err, size, len);
> > + /*
> > + * If I've already sent some but only just got the error, I
> > + * could return the amount validly sent so far and wait
> > for the
> > + * next call to report the error, but I'd rather flag the
> > error
> > + * immediately.
> > + */
> > + return -err;
> > + }
> > +
> > + /* Emulate blocking */
> > + GPollFD pfd;
> > +
> > + pfd.fd = s->fd;
> > + pfd.events = G_IO_OUT | G_IO_ERR;
> > + pfd.revents = 0;
> > + g_poll(&pfd, 1 /* 1 fd */, -1 /* no timeout */);
> > + }
> > + }
> > +
> > + return offset;
> > }
> >
> > static int socket_get_fd(void *opaque)
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
