[CRIU] [PATCH v3 01/11] mount: save fs root fd of ps tree root mnt ns in its ns_id

[Andrei Vagin]

On Tue, Aug 23, 2016 at 03:05:59PM +0300, Pavel Emelyanov wrote:
> Cc Andrey.
> 
> This correlates with your patches that rework opening procedure.

In my patches, roots for all namespaces are opened too.

BTW: Why do you not commit my patches?

> 
> On 08/10/2016 10:12 PM, Eugene Batalov wrote:
> > New criu gc command needs to access files in every ps tree ns.
> > It will use ns_id.mnt.root_fd for this.
> > ps tree processes shouldn't be created during criu gc so we can't
> > use /proc/$ns_pid/root based schema used in criu restore command.
> > 
> > Signed-off-by: Eugene Batalov <eabatalov89 at gmail.com>
> > ---
> >  criu/mount.c | 7 +++++--
> >  1 file changed, 5 insertions(+), 2 deletions(-)
> > 
> > diff --git a/criu/mount.c b/criu/mount.c
> > index 0f81681..7bbd30b 100644
> > --- a/criu/mount.c
> > +++ b/criu/mount.c
> > @@ -3160,8 +3160,7 @@ void fini_restore_mntns(void)
> >  		if (nsid->nd != &mnt_ns_desc)
> >  			continue;
> >  		close_safe(&nsid->mnt.ns_fd);
> > -		if (nsid->type != NS_ROOT)
> > -			close_safe(&nsid->mnt.root_fd);
> > +		close_safe(&nsid->mnt.root_fd);
> >  		nsid->ns_populated = true;
> >  	}
> >  }
> > @@ -3495,6 +3494,10 @@ ns_created:
> >  			nsid->mnt.ns_fd = open_proc(PROC_SELF, "ns/mnt");
> >  			if (nsid->mnt.ns_fd < 0)
> >  				goto err;
> > +			/* root_fd is used to restore file mappings */
> > +			nsid->mnt.root_fd = open_proc(PROC_SELF, "root");
> > +			if (nsid->mnt.root_fd < 0)
> > +				goto err;
> >  			/* we set ns_populated so we don't need to open root_fd */
> >  			nsid->ns_populated = true;
> >  			continue;
> > 
>