From 1680e9063ea28099a1efa8ca11cee069cc7a9bc3 Mon Sep 17 00:00:00 2001
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: Thu, 15 Jul 2010 15:19:12 +0300
Subject: vhost-net: avoid flush under lock

We flush under vq mutex when changing backends.
This creates a deadlock as workqueue being flushed
needs this lock as well.

https://bugzilla.redhat.com/show_bug.cgi?id=612421

Drop the vq mutex before flush: we have the device mutex
which is sufficient to prevent another ioctl from touching
the vq.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/vhost/net.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 2406377a6e5e..2764e0fbf29b 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -534,11 +534,16 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
 	rcu_assign_pointer(vq->private_data, sock);
 	vhost_net_enable_vq(n, vq);
 done:
+	mutex_unlock(&vq->mutex);
+
 	if (oldsock) {
 		vhost_net_flush_vq(n, index);
 		fput(oldsock->file);
 	}
 
+	mutex_unlock(&n->dev.mutex);
+	return 0;
+
 err_vq:
 	mutex_unlock(&vq->mutex);
 err:
-- 
cgit v1.2.2


From 95c0ec6a97ae82d39a6e13fc01aa76861a4a76d0 Mon Sep 17 00:00:00 2001
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: Thu, 24 Jun 2010 17:10:25 +0300
Subject: vhost: avoid pr_err on condition guest can trigger

Guest can trigger packet truncation by posting
a very short buffer and disabling buffer merging.
Convert pr_err to pr_debug to avoid log from filling
up when this happens.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/vhost/net.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 2764e0fbf29b..2f6185c845e0 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -177,8 +177,8 @@ static void handle_tx(struct vhost_net *net)
 			break;
 		}
 		if (err != len)
-			pr_err("Truncated TX packet: "
-			       " len %d != %zd\n", err, len);
+			pr_debug("Truncated TX packet: "
+				 " len %d != %zd\n", err, len);
 		vhost_add_used_and_signal(&net->dev, vq, head, 0);
 		total_len += len;
 		if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
@@ -275,8 +275,8 @@ static void handle_rx(struct vhost_net *net)
 		}
 		/* TODO: Should check and handle checksum. */
 		if (err > len) {
-			pr_err("Discarded truncated rx packet: "
-			       " len %d > %zd\n", err, len);
+			pr_debug("Discarded truncated rx packet: "
+				 " len %d > %zd\n", err, len);
 			vhost_discard_vq_desc(vq);
 			continue;
 		}
-- 
cgit v1.2.2