[CRIU] [PATCH 04/11] mount: don't set m->bind if m is already mounted

[Pavel Emelyanov]

On 08/05/2014 04:55 PM, Andrew Vagin wrote:
> On Tue, Aug 05, 2014 at 04:36:44PM +0400, Pavel Emelyanov wrote:
>> On 08/03/2014 10:31 PM, Andrey Vagin wrote:
>>> m->bind will be used to get the lowest mount.
>>>
>>> mount is "lowest", if m->bind is NULL. The "lowest" moutn is mounted, all
>>> other are bind-mounted from it.
>>
>> How can this happen? I mean -- how can a mount be mounted before we get
>> into the calls you patch?
> 
> propagate_siblings() is called for each mount and it marks other mounts.
> A part of these other mounts can be already mounted.

OK. And what's wrong in marking such mounted mounts with "bind" field?

>>
>>> Signed-off-by: Andrey Vagin <avagin at openvz.org>
>>> ---
>>>  mount.c | 6 ++++++
>>>  1 file changed, 6 insertions(+)
>>>
>>> diff --git a/mount.c b/mount.c
>>> index 80ed133..d1f1f78 100644
>>> --- a/mount.c
>>> +++ b/mount.c
>>> @@ -1197,11 +1197,15 @@ static int propagate_siblings(struct mount_info *mi)
>>>  	 * to inherite shared group or master id
>>>  	 */
>>>  	list_for_each_entry(t, &mi->mnt_share, mnt_share) {
>>> +		if (t->mounted)
>>> +			continue;
>>>  		pr_debug("\t\tBind %s\n", t->mountpoint);
>>>  		t->bind = mi;
>>>  	}
>>>  
>>>  	list_for_each_entry(t, &mi->mnt_slave_list, mnt_slave) {
>>> +		if (t->mounted)
>>> +			continue;
>>>  		pr_debug("\t\tBind %s\n", t->mountpoint);
>>>  		t->bind = mi;
>>>  	}
>>> @@ -1242,6 +1246,8 @@ skip_parent:
>>>  	 */
>>>  	if (fsroot_mounted(mi) || mi->parent == NULL)
>>>  		list_for_each_entry(t, &mi->mnt_bind, mnt_bind) {
>>> +			if (t->mounted)
>>> +				continue;
>>>  			if (t->bind)
>>>  				continue;
>>>  			if (t->master_id)
>>>
>>
> .
>