Return-path: Received: from s3.sipsolutions.net ([144.76.43.152]:42715 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751123AbaAPNxU (ORCPT ); Thu, 16 Jan 2014 08:53:20 -0500 Message-ID: <1389880396.4345.6.camel@jlt4.sipsolutions.net> (sfid-20140116_145323_179184_268ABD76) Subject: Re: [PATCH] nl80211: Reset split_start on error path when split dump is not used From: Johannes Berg To: Pontus Fuchs Cc: linux-wireless@vger.kernel.org Date: Thu, 16 Jan 2014 14:53:16 +0100 In-Reply-To: <52D7E3C1.4090308@gmail.com> (sfid-20140116_145102_990344_1690246A) References: <1389879279-20832-1-git-send-email-pontus.fuchs@gmail.com> (sfid-20140116_143453_482265_044A6882) <1389879668.4345.5.camel@jlt4.sipsolutions.net> <52D7E3C1.4090308@gmail.com> (sfid-20140116_145102_990344_1690246A) Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Thu, 2014-01-16 at 14:50 +0100, Pontus Fuchs wrote: > On 2014-01-16 14:41, Johannes Berg wrote: > > On Thu, 2014-01-16 at 14:34 +0100, Pontus Fuchs wrote: > >> When the netlink skb is exhausted split_start is left set. In the > >> subsequent retry, with a larger buffer, the dump is continued from the > >> failing point instead of from the beginning. > > > > Hmm. Maybe it should be like this instead? > > > > johannes > > > > diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c > > index 138dc3b..2e08af5 100644 > > --- a/net/wireless/nl80211.c > > +++ b/net/wireless/nl80211.c > > @@ -1680,6 +1680,7 @@ static int nl80211_dump_wiphy(struct sk_buff *skb, struct netlink_callback *cb) > > !skb->len && > > cb->min_dump_alloc < 4096) { > > cb->min_dump_alloc = 4096; > > + state->split_start = 0; > > rtnl_unlock(); > > return 1; > > } > > Will that not cause problem if split scan is in use and one of the split > chunks needs to be resent due to EMSGSIZE? That's not supposed to happen, and the "!skb->len" check should catch it. johannes