[CRIU] [PATCH] dump: pre-load kernel modules

[Christopher Covington]

On 10/14/2014 06:21 AM, Pavel Emelyanov wrote:
> On 10/14/2014 11:49 AM, Tycho Andersen wrote:

>> diff --git a/sockets.c b/sockets.c
>> index 0268d35..6c71503 100644
>> --- a/sockets.c
>> +++ b/sockets.c
>> @@ -96,6 +96,41 @@ bool socket_test_collect_bit(unsigned int family, unsigned int proto)
>>  	return test_bit(nr, socket_cl_bits) != 0;
>>  }
>>  
>> +void preload_socket_modules()
>> +{
>> +	/*
>> +	 * If the task to dump (e.g. an LXC container) has any netlink
>> +	 * KOBJECT_UEVENT socket open and the _diag modules aren't
>> +	 * loaded is dumped, criu will freeze the task and then the
>> +	 * kernel will send it messages on the socket, and then we will
>> +	 * fail to dump because the socket has pending data. The Real
>> +	 * Solution is to dump this pending data, but we just modprobe
>> +	 * things beforehand for now so that the first dump doesn't
>> +	 * fail.
>> +	 *
>> +	 * We ignore failure since these could be compiled directly
>> +	 * in, instead of being kernel modules.
>> +	 */
>> +	char *modules[] = {
>> +		"netlink_diag",
>> +		"af_packet_diag",
>> +		"udp_diag",
>> +		"tcp_diag",
>> +		"unix_diag",
>> +		NULL,
>> +	};
>> +	int i;
>> +	char *args[2] = {
>> +		"modprobe",
>> +		NULL
>> +	};
>> +
>> +	for (i = 0; modules[i]; i++) {
>> +		args[1] = modules[i];
>> +		cr_system(-1, -1, -1, args[0], args);

With this patch I get the following spurious prints. Is there some way they
could be avoided?

(00.058688) Error (util.c:571): exited, status=1
(00.112076) Error (util.c:571): exited, status=1
(00.161681) Error (util.c:571): exited, status=1
(00.200197) Error (util.c:571): exited, status=1
(00.251205) Error (util.c:571): exited, status=1

>> +	}
>> +}

Thanks,
Chris

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