vhost/vsock: split out vhost_vsock_drop_backends helper

Split the actual backend dropping part from vhost_vsock_stop.  We're
going to need it for the VHOST_RESET_OWNER implementation in the
following patch, when vsock->dev.mutex is already taken and owner is
checked.

Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
Reviewed-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-ID: <20260724114542.734623-2-andrey.drobyshev@virtuozzo.com>

1 files changed, 17 insertions, 9 deletions

diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index abed1fbcf66c..0835f942684f 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -664,9 +664,24 @@ err:
 	return ret;
 }
 
-static int vhost_vsock_stop(struct vhost_vsock *vsock, bool check_owner)
+static void vhost_vsock_drop_backends(struct vhost_vsock *vsock)
 {
+	struct vhost_virtqueue *vq;
 	size_t i;
+
+	lockdep_assert_held(&vsock->dev.mutex);
+
+	for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
+		vq = &vsock->vqs[i];
+
+		mutex_lock(&vq->mutex);
+		vhost_vq_set_backend(vq, NULL);
+		mutex_unlock(&vq->mutex);
+	}
+}
+
+static int vhost_vsock_stop(struct vhost_vsock *vsock, bool check_owner)
+{
 	int ret = 0;
 
 	mutex_lock(&vsock->dev.mutex);
@@ -677,14 +692,7 @@ static int vhost_vsock_stop(struct vhost_vsock *vsock, bool check_owner)
 			goto err;
 	}
 
-	for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
-		struct vhost_virtqueue *vq = &vsock->vqs[i];
-
-		mutex_lock(&vq->mutex);
-		vhost_vq_set_backend(vq, NULL);
-		mutex_unlock(&vq->mutex);
-	}
-
+	vhost_vsock_drop_backends(vsock);
 err:
 	mutex_unlock(&vsock->dev.mutex);
 	return ret;