Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([174.143.236.118]:42049 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752513AbaH1Twe (ORCPT ); Thu, 28 Aug 2014 15:52:34 -0400 Date: Thu, 28 Aug 2014 15:52:31 -0400 From: "J. Bruce Fields" To: Trond Myklebust Cc: kbuild test robot , "J. Bruce Fields" , kbuild-all@01.org, Linux NFS Mailing List Subject: Re: [nfsd:nfsd-next 5/23] net/sunrpc/svc_xprt.c:794:20: error: 'current_task' undeclared Message-ID: <20140828195231.GA25203@fieldses.org> References: <53f0db34.mtq2J6NaXWKpR15G%fengguang.wu@intel.com> <20140818161836.GA32603@fieldses.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-nfs-owner@vger.kernel.org List-ID: On Wed, Aug 20, 2014 at 06:33:06PM -0400, Trond Myklebust wrote: > On Mon, Aug 18, 2014 at 12:18 PM, J. Bruce Fields wrote: > > On Mon, Aug 18, 2014 at 12:41:24AM +0800, kbuild test robot wrote: > >> tree: git://linux-nfs.org/~bfields/linux.git nfsd-next > >> head: da8b8f7602ed3b8105c6247a2844455fec72caaa > >> commit: 983c684466e02b21f83c025ea539deee6c0aeac0 [5/23] SUNRPC: get rid of the request wait queue > >> config: make ARCH=xtensa allyesconfig > >> > >> All error/warnings: > >> > >> net/sunrpc/svc_xprt.c: In function 'svc_recv': > >> >> net/sunrpc/svc_xprt.c:794:20: error: 'current_task' undeclared (first use in this function) > >> rqstp->rq_task = current_task; > >> ^ > >> net/sunrpc/svc_xprt.c:794:20: note: each undeclared identifier is reported only once for each function it appears in > >> > >> vim +/current_task +794 net/sunrpc/svc_xprt.c > >> > >> 788 printk(KERN_ERR > >> 789 "svc_recv: service %p, transport not NULL!\n", > >> 790 rqstp); > >> 791 > >> 792 /* Make sure the task pointer is set! */ > >> 793 if (WARN_ON_ONCE(!rqstp->rq_task)) > >> > 794 rqstp->rq_task = current_task; > > > > I appreciate the effort to fail gracefully here, but maybe this would be > > a case for simple BUG_ON()? > > > > I don't think there are normally any important locks held here, and I > > can't see any other reason why killing a server thread would bring a box > > down. > > > > And the first developer to forget to set rq_task on a newly created > > server will get an immediate bug, so this should be obvious enough. > > Unless there's fear of a race between starting the thread and setting > > rq_task? > > No, there is no fear of a race. I'm fine with removing the above check > altogether and just letting code Oops if it turns out that we add new > cases that don't set rq_task. OK, I'll remove it entirely. > Ultimately, though, I think we need a better interface for starting > RPC server threads; something that combines svc_prepare_thread() and > kthread_run() into a single function call and that can thus set > rqstp->rq_task correctly. Sounds good. --b.