vhost: don't hold onto file pointer for VHOST_SET_VRING_ERR

We already hold a reference to the eventfd_ctx, which is sufficient;
there's no need to hold a reference to the struct file as well.  So get
rid of vhost_virtqueue->error.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 7bf0b73..40a72d1 100644 (file)
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -318,7 +318,6 @@ static void vhost_vq_reset(struct vhost_dev *dev,
        vq->acked_features = 0;
        vq->log_base = NULL;
        vq->error_ctx = NULL;
-       vq->error = NULL;
        vq->kick = NULL;
        vq->call_ctx = NULL;
        vq->log_ctx = NULL;
@@ -616,8 +615,6 @@ void vhost_dev_cleanup(struct vhost_dev *dev)
        for (i = 0; i < dev->nvqs; ++i) {
                if (dev->vqs[i]->error_ctx)
                        eventfd_ctx_put(dev->vqs[i]->error_ctx);
-               if (dev->vqs[i]->error)
-                       fput(dev->vqs[i]->error);
                if (dev->vqs[i]->kick)
                        fput(dev->vqs[i]->kick);
                if (dev->vqs[i]->call_ctx)
@@ -1499,19 +1496,12 @@ long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp)
                        r = -EFAULT;
                        break;
                }
-               eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd);
-               if (IS_ERR(eventfp)) {
-                       r = PTR_ERR(eventfp);
+               ctx = f.fd == -1 ? NULL : eventfd_ctx_fdget(f.fd);
+               if (IS_ERR(ctx)) {
+                       r = PTR_ERR(ctx);
                        break;
                }
-               if (eventfp != vq->error) {
-                       filep = vq->error;
-                       vq->error = eventfp;
-                       ctx = vq->error_ctx;
-                       vq->error_ctx = eventfp ?
-                               eventfd_ctx_fileget(eventfp) : NULL;
-               } else
-                       filep = eventfp;
+               swap(ctx, vq->error_ctx);
                break;
        case VHOST_SET_VRING_ENDIAN:
                r = vhost_set_vring_endian(vq, argp);

diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 0ba877e..e3c463c 100644 (file)
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -92,7 +92,6 @@ struct vhost_virtqueue {
        struct vring_used __user *used;
        const struct vhost_umem_node *meta_iotlb[VHOST_NUM_ADDRS];
        struct file *kick;
-       struct file *error;
        struct eventfd_ctx *call_ctx;
        struct eventfd_ctx *error_ctx;
        struct eventfd_ctx *log_ctx;