[PATCH v4 5/6] add listmount(2) syscall

[Jonathan Corbet]

Miklos Szeredi <mszeredi at redhat.com> writes:

> Add way to query the children of a particular mount.  This is a more
> flexible way to iterate the mount tree than having to parse the complete
> /proc/self/mountinfo.
>
> Allow listing either
>
>  - immediate child mounts only, or
>
>  - recursively all descendant mounts (depth first).

So I have one probably silly question:

> +SYSCALL_DEFINE4(listmount, const struct __mount_arg __user *, req,
> +		u64 __user *, buf, size_t, bufsize, unsigned int, flags)
> +{

Why use struct __mount_arg (or struct mnt_id_req :) here rather than
just passing in the mount ID directly?  You don't use the request_mask
field anywhere.

Thanks,

jon