Return-path: Received: from s3.sipsolutions.net ([144.76.43.152]:37945 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964992AbaCSOGw (ORCPT ); Wed, 19 Mar 2014 10:06:52 -0400 Message-ID: <1395238008.4142.15.camel@jlt4.sipsolutions.net> (sfid-20140319_150658_010472_868B812B) Subject: Re: [PATCH] mac80211: protect AP VLAN list with local->mtx From: Johannes Berg To: Michal Kazior Cc: linux-wireless@vger.kernel.org Date: Wed, 19 Mar 2014 15:06:48 +0100 In-Reply-To: <1394021648-22605-1-git-send-email-michal.kazior@tieto.com> (sfid-20140305_131926_105353_E2E99219) References: <1394021648-22605-1-git-send-email-michal.kazior@tieto.com> (sfid-20140305_131926_105353_E2E99219) Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Wed, 2014-03-05 at 13:14 +0100, Michal Kazior wrote: > It was impossible to change chanctx of master AP > for AP VLANs because the copy function requires > RTNL which can't be simply taken in mac80211 code > due to possible deadlocks. > > This is required for future chanctx reservation > that re-bind vifs to new chanctx. This requires > safe AP VLAN iteration without RTNL. > > Now VLANs can be iterated while holding either > RTNL or local->mtx because the list is modified > while holding both of these locks. No objection really, but maybe it would make more sense to use iflist_mtx? johannes