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Date:   Mon, 18 May 2020 16:42:12 +0200
From:   Christian Brauner <christian.brauner@ubuntu.com>
To:     David Howells <dhowells@redhat.com>
Cc:     mtk.manpages@gmail.com, Miklos Szeredi <mszeredi@redhat.com>,
        lkml <linux-kernel@vger.kernel.org>,
        "linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
        Petr Vorel <pvorel@suse.cz>,
        linux-man <linux-man@vger.kernel.org>
Subject: Re: Setting mount propagation type in new mount API
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On Mon, May 18, 2020 at 03:30:34PM +0100, David Howells wrote:
> Michael Kerrisk (man-pages) <mtk.manpages@gmail.com> wrote:
> 
> > I've been looking at the new mount API (fsopen(), fsconfig(),
> > fsmount(), move_mount(), etc.) and among the details that remain
> > mysterious to me is this: how does one set the propagation type
> > (private/shared/slave/unbindable) of a new mount and change the
> > propagation type of an existing mount?
> 
> Christian said he was going to have a go at writing mount_setattr().  It's not
> trivial as it has to be able to handle AT_RECURSIVE.

Right, I've put this on my roadmap now. It's becoming more urgent for us
too since I've already switched over a few bits to the new mount api to
make use of detached/anonymous mounts.
I've planned to start working on a version early next week.

Christian