Subject: Re: [RFC 5/9] snet: introduce snet_event.c and snet_event.h

From: Samir Bellabes <[email-masked]>
Date: Fri, 08 Jan 2010 08:21:49 +0100

"Serge E. Hallyn" <[email-masked]> writes:

> Quoting Samir Bellabes ([email-masked]):
>> +int snet_event_fill_info(struct sk_buff *skb, struct netlink_callback *cb)
>> +{
>> +	unsigned int i = 0, n = 0;
>> +	int ret = -1;
>> +	unsigned hashs_to_skip = cb->args[0];
>> +	unsigned events_to_skip = cb->args[1];
>> +	struct list_head *l;
>> +	struct snet_event_entry *s;
>> +
>> +	read_lock_bh(&event_hash_lock);
>> +
>> +	if (!event_hash)
>> +		goto errout;
>> +
>> +	for (i = 0; i < event_hash_size; i++) {
>> +		if (i < hashs_to_skip)
>> +			continue;
>
> What is this?

code was duplicated from ctrl_dumpfamily() at net/netlink/genetlink.c
this can be optimized by:
        for (i = hashs_to_skip; i < event_hash_size; i++) {

I will made a patch for ctrl_dumpfamily() right now.

>> +		l = &event_hash[i];
>> +		n = 0;
>> +		list_for_each_entry(s, l, list) {
>> +			if (++n < events_to_skip)
>> +				continue;
>> +			ret = snet_nl_list_fill_info(skb,
>> +						     NETLINK_CB(cb->skb).pid,
>> +						     cb->nlh->nlmsg_seq,
>> +						     NLM_F_MULTI,
>> +						     s->se.protocol,
>> +						     s->se.syscall);
>> +			if (ret < 0)
>> +				goto errout;
>
> So if it returns 0, presumably meaning successfully handled, you
> want to go on processing any duplicates?

first, I found a bug in snet_nl_list_fill_info() which was returning 0
instead of -EMSGSIZE in case there was not enough space to put data.

I'm not sure to understand what may have duplicates, but if you are
talking about the events (struct snet_event_entry), that is not possible
as the insert function checks if the event is already in the hashtable
snet_evh before insertion.