vhost: add __rcu annotations

Also add rcu_dereference_protected() for code paths where locks are held.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
This commit is contained in:
Arnd Bergmann
2010-03-09 19:24:45 +01:00
committed by Paul E. McKenney
parent 65e6bf484c
commit 28457ee69c
3 changed files with 35 additions and 13 deletions

View File

@ -127,7 +127,10 @@ static void handle_tx(struct vhost_net *net)
size_t len, total_len = 0;
int err, wmem;
size_t hdr_size;
struct socket *sock = rcu_dereference(vq->private_data);
struct socket *sock;
sock = rcu_dereference_check(vq->private_data,
lockdep_is_held(&vq->mutex));
if (!sock)
return;
@ -582,7 +585,10 @@ static void vhost_net_disable_vq(struct vhost_net *n,
static void vhost_net_enable_vq(struct vhost_net *n,
struct vhost_virtqueue *vq)
{
struct socket *sock = vq->private_data;
struct socket *sock;
sock = rcu_dereference_protected(vq->private_data,
lockdep_is_held(&vq->mutex));
if (!sock)
return;
if (vq == n->vqs + VHOST_NET_VQ_TX) {
@ -598,7 +604,8 @@ static struct socket *vhost_net_stop_vq(struct vhost_net *n,
struct socket *sock;
mutex_lock(&vq->mutex);
sock = vq->private_data;
sock = rcu_dereference_protected(vq->private_data,
lockdep_is_held(&vq->mutex));
vhost_net_disable_vq(n, vq);
rcu_assign_pointer(vq->private_data, NULL);
mutex_unlock(&vq->mutex);
@ -736,7 +743,8 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
}
/* start polling new socket */
oldsock = vq->private_data;
oldsock = rcu_dereference_protected(vq->private_data,
lockdep_is_held(&vq->mutex));
if (sock != oldsock) {
vhost_net_disable_vq(n, vq);
rcu_assign_pointer(vq->private_data, sock);