[ 3.8.y.z extended stable ] Patch "virtio: console: fix raising SIGIO after port unplug" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    virtio: console: fix raising SIGIO after port unplug

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.7.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 7753ff55b2551e57ea5354fa35662057d5415965 Mon Sep 17 00:00:00 2001
From: Amit Shah <amit.shah at redhat.com>
Date: Mon, 29 Jul 2013 14:21:32 +0930
Subject: virtio: console: fix raising SIGIO after port unplug

commit 92d3453815fbe74d539c86b60dab39ecdf01bb99 upstream.

SIGIO should be sent when a port gets unplugged.  It should only be sent
to prcesses that have the port opened, and have asked for SIGIO to be
delivered.  We were clearing out guest_connected before calling
send_sigio_to_port(), resulting in a sigio not getting sent to
processes.

Fix by setting guest_connected to false after invoking the sigio
function.

Signed-off-by: Amit Shah <amit.shah at redhat.com>
Signed-off-by: Rusty Russell <rusty at rustcorp.com.au>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/char/virtio_console.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 615804c..62834bc 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -1557,12 +1557,14 @@ static void unplug_port(struct port *port)
 	spin_unlock_irq(&port->portdev->ports_lock);

 	if (port->guest_connected) {
+		/* Let the app know the port is going down. */
+		send_sigio_to_port(port);
+
+		/* Do this after sigio is actually sent */
 		port->guest_connected = false;
 		port->host_connected = false;
-		wake_up_interruptible(&port->waitqueue);

-		/* Let the app know the port is going down. */
-		send_sigio_to_port(port);
+		wake_up_interruptible(&port->waitqueue);
 	}

 	if (is_console_port(port)) {
--
1.8.1.2