[CRIU] Re: [PATCH 2/2] sckets: reorganize queues restore

[Pavel Emelyanov]

On 03/02/2012 06:36 PM, Kinsbursky Stanislav wrote:
> First move peer packets to another list, then go over it without checks.
> This allow to add some more usefull debug prints (nr of packets, for example).
> It also allows to restore sockets queues in parallel (which cound be usefull
> later).

How? This list is local.

And it allows to properly compare the queue lenght with socket buf, which is
a) not mentioned in comment
b) done in a wrong manner in the patch -- you should instead raise one to
   bigger value and then decrease it back to initial value (to a value from
   socket image in the future)

> Signed-off-by: Stanislav Kinsbursky <skinsbursky at openvz.org>
> 
> ---
>  sockets.c |   34 +++++++++++++++++++++++++++-------
>  1 files changed, 27 insertions(+), 7 deletions(-)
> 
> diff --git a/sockets.c b/sockets.c
> index 1902d20..f1896fa 100644
> --- a/sockets.c
> +++ b/sockets.c
> @@ -756,17 +756,37 @@ static int restore_socket_queue(struct sk_packets_pool *pool, int fd,
>  {
>  	struct sk_packet *pkt, *tmp;
>  	int ret;
> -
> -	pr_info("%d: Restoring recv queue for %u: ", pool->pid, peer_id);
> +	int size_size, queue_size, pkt_nr = 0, pkts_size = 0;
> +	socklen_t len = sizeof(queue_size);
> +	LIST_HEAD(peer_packets);
>  
>  	list_for_each_entry_safe(pkt, tmp, &pool->packets_list, list) {
> -		struct sk_packet_entry *entry = &pkt->entry;
> -
> -		if (entry->id_for != peer_id)
> +		if (pkt->entry.id_for != peer_id)
>  			continue;
> +		list_move_tail(&pkt->list, &peer_packets);
> +		pkts_size += pkt->entry.length;
> +		pkt_nr++;
> +	}
> +
> +	if (!pkt_nr)
> +		return 0;
> +
> +	pr_info("%d: Restoring recv queue for %u: %d packets (overall size: %d bytes)\n", pool->pid, peer_id, pkt_nr, pkts_size);
>  
> -		pr_info("\tRestoring %d-bytes skb for %u\n",
> -				entry->length, peer_id);
> +	ret = getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &queue_size, &len);
> +	if (ret < 0) {
> +		pr_perror("%d: Failed to get snd buffer size", pool->pid);
> +		return -1;
> +	}
> +
> +	if (pkts_size > queue_size) {
> +		pr_err("%d: Can't restore queue - not enough space: %d (required %d)\n",
> +				pool->pid, queue_size, pkts_size);
> +		return -1;
> +	}
> +
> +	list_for_each_entry_safe(pkt, tmp, &peer_packets, list) {
> +		struct sk_packet_entry *entry = &pkt->entry;
>  
>  		ret = sendfile(fd, pool->img_fd, &pkt->img_off, entry->length);
>  		if (ret < 0) {
>