On (Tue) Mar 23 2010 [11:00:23], Michael S. Tsirkin wrote: > On Tue, Mar 23, 2010 at 02:28:00PM +0530, Amit Shah wrote: > > The virtio-serial ports are like pipes, if there's no reader on the > > other end, sending data might get it either ignored or the host might > > return '0', which would make guests get -EAGAIN. Since we know the state > > of the host port connection, it's appropriate to let the application > > know that the other end isn't connected. > > > > Signed-off-by: Amit Shah <amit.shah@xxxxxxxxxx> > > --- > > drivers/char/virtio_console.c | 3 +++ > > 1 files changed, 3 insertions(+), 0 deletions(-) > > > > diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c > > index 55de0b5..4562964 100644 > > --- a/drivers/char/virtio_console.c > > +++ b/drivers/char/virtio_console.c > > @@ -411,6 +411,9 @@ static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count) > > ssize_t ret; > > unsigned int len; > > > > + if (use_multiport(port->portdev) && !port->host_connected) > > + return -EPIPE; > > + > > Hmm, do applications actually handle this error? As Michael points out on irc, console-handling apps may not handle EPIPE properly. So I guess the test should be reworked to: if (!is_console_port(port) && !port->host_connected) return -EPIPE; Also, he points out that write(2) mentions other error messages can be returned depending on the file type. So we could return -ENOTCONN. Amit _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
