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| author | Michael S. Tsirkin <mst@redhat.com> | 2010-07-15 15:19:12 +0300 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2010-07-15 15:26:12 +0300 |
| commit | 1680e9063ea28099a1efa8ca11cee069cc7a9bc3 (patch) | |
| tree | 92fda29b75a081151d6e460f7ae8ec874517b6e5 | |
| parent | 7b3384fc30633738ae4eaf8e1bc6ce70470ced80 (diff) | |
| download | op-kernel-dev-1680e9063ea28099a1efa8ca11cee069cc7a9bc3.zip op-kernel-dev-1680e9063ea28099a1efa8ca11cee069cc7a9bc3.tar.gz | |
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>
| -rw-r--r-- | drivers/vhost/net.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 2406377..2764e0f 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: |
