Re: [Xen-devel][PATCH 1/2] xen/gntdev: Do not destroy context while dma-bufs are in use

[Oleksandr Andrushchenko]

On 2/15/19 5:03 PM, Boris Ostrovsky wrote:
> On 2/14/19 9:23 AM, Oleksandr Andrushchenko wrote:
> >   
> >   /* DMA buffer export support. */
> > @@ -311,6 +317,7 @@ static void dmabuf_exp_release(struct kref *kref)
> >   
> >   	dmabuf_exp_wait_obj_signal(gntdev_dmabuf->priv, gntdev_dmabuf);
> >   	list_del(&gntdev_dmabuf->next);
> > +	fput(gntdev_dmabuf->priv->filp);
> >   	kfree(gntdev_dmabuf);
> >   }
> >   
> > @@ -423,6 +430,7 @@ static int dmabuf_exp_from_pages(struct gntdev_dmabuf_export_args *args)
> >   	mutex_lock(&args->dmabuf_priv->lock);
> >   	list_add(&gntdev_dmabuf->next, &args->dmabuf_priv->exp_list);
> >   	mutex_unlock(&args->dmabuf_priv->lock);
> > +	get_file(gntdev_dmabuf->priv->filp);
> Not fget()?
fget wants file descriptor [1] and returns struct file *,
but we already have struct file*, so I use get_file [2]
which does what I need - increments the reference counter
on the file
> -boris
[1] 
https://elixir.bootlin.com/linux/v5.0-rc6/source/include/linux/file.h#L46
[2] https://elixir.bootlin.com/linux/v5.0-rc6/source/include/linux/fs.h#L949