vhost: Remove custom vhost rcu usage

Now, vq->private_data is always accessed under vq mutex. No need to play
the vhost rcu trick.

Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 6 insertions, 10 deletions

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 99f8d63491aa..969a85960e9f 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -15,7 +15,6 @@
 #include <linux/moduleparam.h>
 #include <linux/mutex.h>
 #include <linux/workqueue.h>
-#include <linux/rcupdate.h>
 #include <linux/file.h>
 #include <linux/slab.h>
 
@@ -749,8 +748,7 @@ static int vhost_net_enable_vq(struct vhost_net *n,
         struct vhost_poll *poll = n->poll + (nvq - n->vqs);
         struct socket *sock;
 
-        sock = rcu_dereference_protected(vq->private_data,
-                                         lockdep_is_held(&vq->mutex));
+        sock = vq->private_data;
         if (!sock)
                 return 0;
 
@@ -763,10 +761,9 @@ static struct socket *vhost_net_stop_vq(struct vhost_net *n,
         struct socket *sock;
 
         mutex_lock(&vq->mutex);
-        sock = rcu_dereference_protected(vq->private_data,
-                                         lockdep_is_held(&vq->mutex));
+        sock = vq->private_data;
         vhost_net_disable_vq(n, vq);
-        rcu_assign_pointer(vq->private_data, NULL);
+        vq->private_data = NULL;
         mutex_unlock(&vq->mutex);
         return sock;
 }
@@ -922,8 +919,7 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
         }
 
         /* start polling new socket */
-        oldsock = rcu_dereference_protected(vq->private_data,
-                                            lockdep_is_held(&vq->mutex));
+        oldsock = vq->private_data;
         if (sock != oldsock) {
                 ubufs = vhost_net_ubuf_alloc(vq,
                                              sock && vhost_sock_zcopy(sock));
@@ -933,7 +929,7 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
                 }
 
                 vhost_net_disable_vq(n, vq);
-                rcu_assign_pointer(vq->private_data, sock);
+                vq->private_data = sock;
                 r = vhost_init_used(vq);
                 if (r)
                         goto err_used;
@@ -967,7 +963,7 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
         return 0;
 
 err_used:
-        rcu_assign_pointer(vq->private_data, oldsock);
+        vq->private_data = oldsock;
         vhost_net_enable_vq(n, vq);
         if (ubufs)
                 vhost_net_ubuf_put_wait_and_free(ubufs);