From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932912Ab0JXUf6 (ORCPT ); Sun, 24 Oct 2010 16:35:58 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:58973 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932698Ab0JXUf5 (ORCPT ); Sun, 24 Oct 2010 16:35:57 -0400 MIME-Version: 1.0 In-Reply-To: <4CC49274.3030803@fusionio.com> References: <4CC49274.3030803@fusionio.com> From: Linus Torvalds Date: Sun, 24 Oct 2010 13:35:33 -0700 Message-ID: Subject: Re: [GIT PULL] Revert of the IO stat fix To: Jens Axboe Cc: "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Oct 24, 2010 at 1:09 PM, Jens Axboe wrote: > > The fix for cross-partition merges screwing up disk stats turns out > to be problematic on various levels. Lets revert this one so we have > time to come up with a proper solution for this. Hmm.. I think the reverted patch looks like it really is the right thing to do, so I hate reverting it this early. What were the problems with it? Btw, one thing that seems to be missing in the original commit (which is not necessarily the reason for the trouble, of course), is that elv_rq_merge_ok() seems to not check the partition. As far as I can tell, we should have a if (req->part != bio->bi_bdev->bd_part) return 0; there, no? And you should _not_ set rq->part in "drive_stat_acct()", you should set it from bio->bi_bdev->bd_part when you create the request. (And if it is NULL, just don't do partition accounting at all) Hmm? What am I missing? What were the bugs? Linus