Merge branch 'virtio' of git://git.kernel.org/pub/scm/linux/kernel/gi…

…t/rusty/linux-2.6-for-linus

* 'virtio' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  virtio: console: Fix crash when port is unplugged and blocked for write
  virtio: console: Fix crash when hot-unplugging a port and read is blocked
  virtio-blk: fix minimum number of S/G elements

drivers/block/virtio_blk.c

@@ -298,7 +298,9 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
 	err = virtio_config_val(vdev, VIRTIO_BLK_F_SEG_MAX,
 				offsetof(struct virtio_blk_config, seg_max),
 				&sg_elems);
-	if (err)
+
+	/* We need at least one SG element, whatever they say. */
+	if (err || !sg_elems)
 		sg_elems = 1;
 
 	/* We need an extra sg elements at head and tail. */

drivers/char/virtio_console.c

@@ -529,6 +529,10 @@ static bool will_write_block(struct port *port)
 {
 	bool ret;
 
+	if (!port->guest_connected) {
+		/* Port got hot-unplugged. Let's exit. */
+		return false;
+	}
 	if (!port->host_connected)
 		return true;
 
@@ -1099,6 +1103,13 @@ static int remove_port(struct port *port)
 {
 	struct port_buffer *buf;
 
+	if (port->guest_connected) {
+		port->guest_connected = false;
+		port->host_connected = false;
+		wake_up_interruptible(&port->waitqueue);
+		send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
+	}
+
 	spin_lock_irq(&port->portdev->ports_lock);
 	list_del(&port->list);
 	spin_unlock_irq(&port->portdev->ports_lock);
@@ -1120,9 +1131,6 @@ static int remove_port(struct port *port)
 		hvc_remove(port->cons.hvc);
 #endif
 	}
-	if (port->guest_connected)
-		send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
-
 	sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
 	device_destroy(pdrvdata.class, port->dev->devt);
 	cdev_del(&port->cdev);