[CRIU] Sync TODO-s for mount.c work

[Tycho Andersen]

On Tue, Apr 21, 2015 at 07:20:38PM +0300, Andrew Vagin wrote:
> On Tue, Apr 21, 2015 at 08:58:55AM -0600, Tycho Andersen wrote:
> > On Tue, Apr 21, 2015 at 04:18:59PM +0300, Pavel Emelyanov wrote:
> > > Tycho, Oleg,
> > > 
> > > This is just to make sure I properly track what's going on with mount.c :)
> > > 
> > > From my perspective we're definitely missing the RPC bits for the options 
> > > you added recently (enable-fs, skip-mnt, ext-mount-map auto mode and the
> > > enable-external-foo-s) and tests for it.
> > > 
> > > Am I correct?
> > 
> > I can think of two additional things:
> > 
> > 1. we need some way to detect whether we really want to auto dump
> >    fsroot_mounted() mounts or not:
> > 
> >    http://lists.openvz.org/pipermail/criu/2015-April/019878.html
> > 
> >    Unfortunately I've thought about this for a while, and I'm not sure
> >    what a good solution is. Maybe just a warning in the docs that says
> >    you should only do this if you're going to pivot root too?
> > 
> > 2. minor, but I think the restore_shared_options() call in
> >    do_new_mount() is still wrong, since it doesn't do anything when
> >    sharing ids are different between parent and itself, so a totally
> >    internal shared mount can never end up with different sharing than
> >    its parent.
> 
> I don't understand this point. Could you show an example when it's wrong?
> 
> root at ubuntu:/home/avagin# mkdir A
> root at ubuntu:/home/avagin# mount -t tmpfs A A
> root at ubuntu:/home/avagin# mount --make-shared A
> root at ubuntu:/home/avagin# mkdir A/B
> root at ubuntu:/home/avagin# mount -t tmpfs AB A/B
> 
> 52 21 0:41 / /home/avagin/A rw,relatime shared:1 - tmpfs A rw
> 53 52 0:42 / /home/avagin/A/B rw,relatime shared:2 - tmpfs AB rw

Oh, it seems I was confused. I was thinking of the bind mount case.
You are right, this isn't a problem.

Tycho

> > 
> > I can send a patch for 2 today, and I will try to do the RPC/tests
> > ASAP as well.
> > 
> > Tycho
> > 
> > > -- Pavel
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