- sjur.brandeland

From: sjur.brandeland@stericsson.com
To: Amit Shah <amit.shah@redhat.com>, Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>,
	"Masami Hiramatsu" <masami.hiramatsu.pt@hitachi.com>,
	linux-kernel@vger.kernel.org,
	virtualization@lists.linux-foundation.org, sjur@brendeland.net,
	"Sjur Brændeland" <sjur.brandeland@stericsson.com>
Subject: 
Date: Wed,  7 Nov 2012 15:22:51 +0100	[thread overview]
Message-ID: <1352298171-21869-1-git-send-email-sjur.brandeland@stericsson.com> (raw)
In-Reply-To: <20121102102047.GE10483@amit.redhat.com>

>From 0ce16d6a0270daebd9972e94a834034a093228b0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sjur=20Br=C3=A6ndeland?= <sjur.brandeland@stericsson.com>
Date: Wed, 7 Nov 2012 12:20:07 +0100
Subject: [PATCH] virtio_console:Free buffers from out-queue upon close
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Free pending output buffers from the virtio out-queue when
host has acknowledged port_close. Also removed WARN_ON()
in remove_port_data().

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
---
Hi Amit,

Note: This patch is compile tested only. I have done the removal
of buffers from out-queue in handle_control_message()
when host has acked the close request. This seems less
racy than doing it in the release function.

I you want to change this further, feel free to take over from
here and refine this.

Thanks,
Sjur

 drivers/char/virtio_console.c |   14 ++++++--------
 1 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 3fa036a..3a5831d 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -1522,15 +1522,9 @@ static void remove_port_data(struct port *port)
 	while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
 		free_buf(buf, true);
 
-	/*
-	 * Check the out-queue for buffers. For VIRTIO_CONSOLE it is a
-	 * bug if this happens. But for RPROC_SERIAL the remote processor
-	 * may have crashed, leaving buffers hanging in the out-queue.
-	 */
-	while ((buf = virtqueue_detach_unused_buf(port->out_vq))) {
-		WARN_ON_ONCE(!is_rproc_serial(port->portdev->vdev));
+	/* Free pending buffers from the out-queue. */
+	while ((buf = virtqueue_detach_unused_buf(port->out_vq)))
 		free_buf(buf, true);
-	}
 }
 
 /*
@@ -1655,6 +1649,10 @@ static void handle_control_message(struct ports_device *portdev,
 		 */
 		spin_lock_irq(&port->outvq_lock);
 		reclaim_consumed_buffers(port);
+
+		/* Free pending buffers from the out-queue. */
+		while ((buf = virtqueue_detach_unused_buf(port->out_vq)))
+			free_buf(buf, true);
 		spin_unlock_irq(&port->outvq_lock);
 
 		/*
-- 
1.7.5.4

