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

[Pavel Emelyanov]

On 04/23/2015 05:31 PM, Tycho Andersen wrote:
> On Thu, Apr 23, 2015 at 02:52:35PM +0300, Pavel Emelyanov wrote:
>> On 04/23/2015 02:17 PM, Oleg Nesterov wrote:
>>
>>> Now what? Obviously we can't just add
>>>
>>> 	if (is_not_external_mount(m))
>>> 		continue;
>>
>> Why not? The is_not_external_mount() is
>>
>> fsroot_mounted(m) || /* mount's root is visible from chroot */
> 
> But what if the mount's root is /? e.g with pstore in lxc, the
> mountinfo from inside looks like:
> 
> 110 104 0:23 / /sys/fs/pstore rw,nosuid,nodev,noexec,relatime master:11 - pstore pstore rw
> 
> which is a bind mount from the host's:
> 
> 29 17 0:23 / /sys/fs/pstore rw,nosuid,nodev,noexec,relatime shared:11 - pstore pstore rw

Ah, so sharing takes place. OK, then (sorry, maybe I'm replaying your
conversation again, but I'm still blind about it) the check should be

   (fsroot_mounted(m) || root_is_visible(m)) && master_is_external(m)

?

-- Pavel