From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756367Ab0ITNDf (ORCPT ); Mon, 20 Sep 2010 09:03:35 -0400 Received: from verein.lst.de ([213.95.11.210]:53162 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754206Ab0ITNDe (ORCPT ); Mon, 20 Sep 2010 09:03:34 -0400 Date: Mon, 20 Sep 2010 15:03:18 +0200 From: Christoph Hellwig To: vgoyal@redhat.com Cc: jaxboe@fusionio.com, linux-kernel@vger.kernel.org Subject: cgq vs bdi names, was "cfq-iosched: fix a kernel OOPs when usb key is inserted" Message-ID: <20100920130318.GA29565@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.28i X-Spam-Score: 0 () Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Vivek, hi Jens, where was http://git.kernel.dk/?p=linux-2.6-block.git;a=commitdiff_plain;h=44c74d6292e97f8bd9adfa6b0df3cb4f3c42a6dc posted on the mailinglist? I can't find it in my lkml or fsdevel inboxes. Either way I don't think just papering over the underlying issue like this is a good idea. The big issue is that cfq tries to scanf the textual representation of the dev_t from the request_queue by abusing the bdi. But the reason why we don't have a dev_t in the request_queue is that it's still not unique. If it was we could easily add a dev_t into the request_queue and be done with it. So the fix is either to get rid of the last remaining users of shared request_queues (IIRC the various floppy drivers) and just add a dev_t in the request_queue for the bdi, tracing and cfq, or add a dev_t into the request_queue and add a flag for shared request queues that the floppy driver and whoever needs it set and let the bdi sysfs code, cfq and blocktrace ignore theis request_queue. This will also allow to get rid of the crap about ignoring failures due to already register or prematurely unregistered bdis and actually add real error handling to that code.