Re: [PATCH 2/4] mdev: Make mdev alias unique among all mdevs

Cornelia Huck
2019-08-27T10:29:41Z

On Mon, 26 Aug 2019 15:41:17 -0500
Parav Pandit <parav@mellanox.com> wrote:

> Mdev alias should be unique among all the mdevs, so that when such alias
> is used by the mdev users to derive other objects, there is no
> collision in a given system.
>
> Signed-off-by: Parav Pandit <parav@mellanox.com>
> ---
> drivers/vfio/mdev/mdev_core.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
> index e825ff38b037..6eb37f0c6369 100644
> --- a/drivers/vfio/mdev/mdev_core.c
> +++ b/drivers/vfio/mdev/mdev_core.c
> @@ -375,6 +375,11 @@ int mdev_device_create(struct kobject *kobj, struct device *dev,
> ret = -EEXIST;
> goto mdev_fail;
> }
> + if (tmp->alias && strcmp(tmp->alias, alias) == 0) {

Any way we can relay to the caller that the uuid was fine, but that we
had a hash collision? Duplicate uuids are much more obvious than a
collision here.

> + mutex_unlock(&mdev_list_lock);
> + ret = -EEXIST;
> + goto mdev_fail;
> + }
> }
>
> mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);