From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761431AbYESODt (ORCPT ); Mon, 19 May 2008 10:03:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759132AbYESODl (ORCPT ); Mon, 19 May 2008 10:03:41 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:46195 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758667AbYESODl (ORCPT ); Mon, 19 May 2008 10:03:41 -0400 Date: Mon, 19 May 2008 10:03:39 -0400 From: Christoph Hellwig To: Andi Kleen Cc: corbet@lwn.net, linux-kernel@vger.kernel.org Subject: Re: [PATCH] [2/11] Add unlocked_fasync Message-ID: <20080519140339.GB24267@infradead.org> References: <20080519231.561421028@firstfloor.org> <20080519123111.97C0C1B41FF@basil.firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080519123111.97C0C1B41FF@basil.firstfloor.org> User-Agent: Mutt/1.5.17 (2007-11-01) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 19, 2008 at 02:31:11PM +0200, Andi Kleen wrote: > > Add a new fops entry point to allow fasync without BKL. While it's arguably > unclear this entry point is called often enough for it really matters > it was still relatively easy to do. And there are far less async users > in the tree than ioctls so it's likely they can be all converted > eventually and then the non unlocked async entry point could be dropped. > > There was still the problem of the actual flags change being > protected against other setters of flags. Instead of using BKL > for this use the i_mutex now. > > I also added a mutex_lock against one other flags change > that was lockless and could potentially lose updates. > > There are a couple of potential problems I added comments about on. I'd rather do a properly flag day and move lock_kernel into the instances instead of adding this _unlocked gunk.