Re: [dpdk-dev] [PATCH] vhost: Fix `struct file' leakage in `eventfd_link'

["Xie, Huawei" <huawei.xie@intel.com>]

On 3/23/2015 8:54 PM, Pavel Boldin wrote:
> Due to increased `struct file's reference counter subsequent call
> to `filp_close' does not free the `struct file'. Prepend `fput' call
> to decrease the reference counter.
>
> Signed-off-by: Pavel Boldin <pboldin@mirantis.com>
> ---
>  lib/librte_vhost/eventfd_link/eventfd_link.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/lib/librte_vhost/eventfd_link/eventfd_link.c b/lib/librte_vhost/eventfd_link/eventfd_link.c
> index 7755dd6..62c45c8 100644
> --- a/lib/librte_vhost/eventfd_link/eventfd_link.c
> +++ b/lib/librte_vhost/eventfd_link/eventfd_link.c
> @@ -117,6 +117,7 @@ eventfd_link_ioctl(struct file *f, unsigned int ioctl, unsigned long arg)
>  		 * Release the existing eventfd in the source process
>  		 */
>  		spin_lock(&files->file_lock);
> +		fput(file);
>  		filp_close(file, files);
>  		fdt = files_fdtable(files);
>  		fdt->fd[eventfd_copy.source_fd] = NULL;
Acked-by Huawei Xie <huawei.xie@intel.com>

In future, we should remove the allocation of src eventfd, allocate a
free fd from kernel, and install it with target fd.