From 1680e9063ea28099a1efa8ca11cee069cc7a9bc3 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" 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 --- drivers/vhost/net.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/vhost/net.c') 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 v1.2.3 From 95c0ec6a97ae82d39a6e13fc01aa76861a4a76d0 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" 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 --- drivers/vhost/net.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'drivers/vhost/net.c') 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 v1.2.3