Re: BUG ? ipip unregister_netdevice_many()

[Jarek Poplawski <jarkao2@gmail.com>]

On 2010-10-12 22:05, David Miller wrote:
> From: ebiederm@xmission.com (Eric W. Biederman)
> Date: Fri, 08 Oct 2010 10:32:40 -0700
> 
>> It is just dealing with not flushing the entire routing cache, just the
>> routes that have expired.  Which prevents one network namespace from
>> flushing it's routes and DOS'ing another.
> 
> That's a very indirect and obfuscated way of handling it.
> 
> And I still don't know why we let the first contiguous set of expired
> entries in the chain get freed outside of the lock, and the rest
> inside the lock.  That really isn't explained by anything I've read.
> 
> How about we just do exactly what's intended, and with no ifdefs?
> 
> Signed-off-by: David S. Miller <davem@davemloft.net>
...
> diff --git a/net/ipv4/route.c b/net/ipv4/route.c
> index 0755aa4..6ad730c 100644
> --- a/net/ipv4/route.c
> +++ b/net/ipv4/route.c
> @@ -712,13 +712,14 @@ static inline int rt_is_expired(struct rtable *rth)
>   * Can be called by a softirq or a process.
>   * In the later case, we want to be reschedule if necessary
>   */
> -static void rt_do_flush(int process_context)
> +static void rt_do_flush(struct net *net, int process_context)
>  {
>  	unsigned int i;
>  	struct rtable *rth, *next;
> -	struct rtable * tail;
>  
>  	for (i = 0; i <= rt_hash_mask; i++) {
> +		struct rtable *list, **pprev;

Isn't "list = NULL" needed here?

Jarek P.

...
> +				rth->dst.rt_next = list;
> +				list = rth;
> +			} else
> +				pprev = &rth->dst.rt_next;
> +
> +			rth = next;
...