[CRIU] [PATCH v2 06/15] unix: Add sender_ino of packets and socket

[Pavel Emelyanov]

On 05/30/2016 03:30 PM, Kirill Tkhai wrote:
> 
> 
> On 30.05.2016 14:40, Pavel Emelyanov wrote:
>> On 05/27/2016 04:06 PM, Kirill Tkhai wrote:
>>> Add optional field "sender_ino" to packet and socket proto.
>>>
>>> Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
>>> ---
>>>  images/sk-packet.proto |    1 +
>>>  images/sk-unix.proto   |    2 ++
>>>  2 files changed, 3 insertions(+)
>>>
>>> diff --git a/images/sk-packet.proto b/images/sk-packet.proto
>>> index 10ef5c9..2e1c8b3 100644
>>> --- a/images/sk-packet.proto
>>> +++ b/images/sk-packet.proto
>>> @@ -1,4 +1,5 @@
>>>  message sk_packet_entry {
>>>  	required uint32		id_for		= 1;
>>>  	required uint32		length		= 2;
>>> +	optional uint32		sender_ino	= 3;
>>
>> This is understood.
>>
>>>  }
>>> diff --git a/images/sk-unix.proto b/images/sk-unix.proto
>>> index aa2bcf7..7b71ebf 100644
>>> --- a/images/sk-unix.proto
>>> +++ b/images/sk-unix.proto
>>> @@ -45,4 +45,6 @@ message unix_sk_entry {
>>>  	 * Relative socket name may have prefix.
>>>  	 */
>>>  	optional string			name_dir	= 14;
>>> +
>>> +	optional uint32			sender_ino	= 15;
>>
>> Why do you need this new number on socket entry?
> 
> This allows to understand that a DGRAM socket is not a promiscuous.
> If so, we may set a sender as our queuer (see sk_queuer()).
> 
> Otherwise, we would have to do additional work on restore. We would
> have to scan skb queue to understand if it's promiscuous.
> 
> Using unix_sk_entry::sender_ino, we easily mark the most sockets as
> "having queuer", and skip them on "resolve senders" stage.
> See resolve_unix_peers() changes.

OK. From my perspective you don't need this in image. During resolve_unix_peers()
we scan all the sockets, you can add analysis of the packets and find out
whether the socket is no-queuer or not.