From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net-next] cnic: Fix rtnl deadlock Date: Fri, 08 Apr 2011 13:03:12 -0700 (PDT) Message-ID: <20110408.130312.71109273.davem@davemloft.net> References: <1302284654-25864-1-git-send-email-mchan@broadcom.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: mchan@broadcom.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:59558 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757833Ab1DHUDs (ORCPT ); Fri, 8 Apr 2011 16:03:48 -0400 In-Reply-To: <1302284654-25864-1-git-send-email-mchan@broadcom.com> Sender: netdev-owner@vger.kernel.org List-ID: From: "Michael Chan" Date: Fri, 8 Apr 2011 10:44:14 -0700 > When cnic_stop_hw() -> cnic_cm_stop_bnx2x_hw() is called under rtnl_lock() > from NETDEV_DOWN event, it waits for cnic_delete_task() to complete. > It will deadlock when cnic_delete_task() takes rtnl_lock() before > calling cnic_ulp_stop_one(). > > We fix it by removing the rtnl_lock() in cnic_delete_task(). > cnic_ulp_stop_one() has mutex and atomic bit ops to prevent important > operations from being done more than once, so it is not necessary to take > rtnl_lock(). > > Signed-off-by: Michael Chan Applied, thanks Michael.