Re: [PATCH 0/3] use do_mount() instead of ksys_mount()

From: Al Viro
Date: Thu Dec 12 2019 - 13:37:40 EST

On Thu, Dec 12, 2019 at 09:11:10AM -0800, Linus Torvalds wrote:
> On Thu, Dec 12, 2019 at 5:59 AM Dominik Brodowski
> <linux@xxxxxxxxxxxxxxxxxxxx> wrote:
> >
> > This small series replaces all in-kernel calls to the
> > userspace-focused wrapper ksys_mount() with calls to
> > the kernel-centric do_mount().
> If you fix the pointless cast I pointed out, and put it in a git
> branch, I'll pull it.
> In fact, just do both series in the same branch, they do conceptually
> the same thing, after all.

IMO it's not a good idea. Exposing the guts of fs/namespace.c to
what's essentially a userland code that happens to run in kernel thread
is asking for trouble - we'd been there and it had been hell to untangle.