From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Moyer Subject: Re: [RFC 0/5] dio: clean up completion phase of direct_io_worker() Date: Wed, 06 Sep 2006 10:57:09 -0400 Message-ID: References: <20060905235732.29630.3950.sendpatchset@tetsuo.zabbo.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-fsdevel@vger.kernel.org, linux-aio@kvack.org, linux-kernel@vger.kernel.org Return-path: Received: from mx1.redhat.com ([66.187.233.31]:42441 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S1751228AbWIFO5R (ORCPT ); Wed, 6 Sep 2006 10:57:17 -0400 To: Zach Brown In-Reply-To: <20060905235732.29630.3950.sendpatchset@tetsuo.zabbo.net> (Zach Brown's message of "Tue, 5 Sep 2006 16:57:32 -0700 (PDT)") Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org ==> Regarding [RFC 0/5] dio: clean up completion phase of direct_io_worker(); Zach Brown adds: zach.brown> There have been a lot of bugs recently due to the way zach.brown> direct_io_worker() tries to decide how to finish direct IO zach.brown> operations. In the worst examples it has failed to call zach.brown> aio_complete() at all (hang) or called it too many times zach.brown> (oops). zach.brown> This set of patches cleans up the completion phase with the zach.brown> goal of removing the complexity that lead to these bugs. We zach.brown> end up with one path that calculates the result of the zach.brown> operation after all off the bios have completed. We decide zach.brown> when to generate a result of the operation using that path zach.brown> based on the final release of a refcount on the dio structure. [...] zach.brown> I hoped to get some feedback (and maybe volunteers for zach.brown> testing!) by sending the patches out before waiting for the zach.brown> stress tests. This all looks good, the code is much easier to follow. What do you think about making dio->result an unsigned quantity? It should never be negative now that there is an io_error field. ACK. Jeff