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

Miklos Szeredi [off-list ref] 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