[CRIU] dumping sockets with external peers

[Tycho Andersen]

Hi Pavel,

On Thu, Nov 19, 2015 at 04:05:56PM +0300, Pavel Emelyanov wrote:
> On 11/17/2015 11:40 PM, Tycho Andersen wrote:
> > hi all,
> > 
> > I'm getting an error when dumping a container:
> > 
> > (00.429560) sk unix:    Ext stream not supported: ino 0x7e559 peer_ino 0x7dadc family    1 type    1 state  1 name (null)
> > 
> > I've passed --ext-unix-sk=0x7dadc (the peer, which happens to be a
> > named socket connected to the path I know is bind mounted into the
> > container), but I don't have a way to figure out that 0x7e559 is a
> > peer for this external socket.
> 
> It is :) CRIU gets this from kernel, but you can check it's right
> or not by "ss -xanp" command -- the numbers called "Port" are inodes
> and peer inodes.
> 
> > I'm not exactly sure what the right solution here is. It seems to me
> > that *any* peer of an external socket should be considered external
> > and restored as such, but I know very little about this.
> 
> But does it dump with --ext-unix-sk=0x7dadc?

It has --ext-unix-sk=0x7dadc, but not --ext-unix-sk=0x7ee559, because
I have something like this:

$ ss -xanp | grep 695082
u_str  ESTAB      0      0      /sys/fs/cgroup/cgmanager/sock 696033                * 695082             
u_str  ESTAB      0      0         * 695082                * 696033              users:(("cgproxy",pid=1388,fd=3))

(where /sys/fs/cgroup/cgmanager/sock is the socket that's bind mounted into the
container that something has connected to.)

What I'm not sure about is how to correctly c/r the second line. The first line
should be ok with --ext-unix-sk.

Tycho