Re: [PATCH v2] netfilter: nf_sockopt_find() / nf_register_sockopt() should not return EINTR

[Patrick McHardy <kaber@trash.net>]

On 31. Juli 2014 11:55:25 GMT+01:00, Pablo Neira Ayuso <pablo@netfilter.org> wrote:
>On Thu, Jul 24, 2014 at 10:41:35PM +0200, Eric Dumazet wrote:
>> From: Eric Dumazet <edumazet@google.com>
>> 
>> getsockopt() or setsockopt() sometimes returns -EINTR instead of
>> -ENOPROTOOPT, causing headaches to application developers.
>> 
>> This is because unsupported commands might go through
>nf_sockopt_find()
>> and this function returns -EINTR if a signal is pending.
>> 
>> Just use non interruptible mutex functions, as there is no reason
>> we should sleep for a long time here.
>
>On top of this patch, I think that at least we can also ged rid of
>these interruptible mutex from the netfilter/core code too (see
>preliminary patch attached).

Agreed. I think there are actually no cases at all where using the
interruptable variants makes sense.

>I can also adapt the callers so they don't check anymore the return
>value as they will always succeed.
>
>Comments? Thanks.

I'd leave checks in the callers at least for all init/registration functions.
Quite possible future changes will add back error conditions and its
more consistent to follow this convention in all cases.