From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760881AbYCGCRL (ORCPT ); Thu, 6 Mar 2008 21:17:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754453AbYCGCQy (ORCPT ); Thu, 6 Mar 2008 21:16:54 -0500 Received: from srv5.dvmed.net ([207.36.208.214]:43016 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754262AbYCGCQx (ORCPT ); Thu, 6 Mar 2008 21:16:53 -0500 Message-ID: <47D0A58D.3050500@garzik.org> Date: Thu, 06 Mar 2008 21:16:45 -0500 From: Jeff Garzik User-Agent: Thunderbird 2.0.0.12 (X11/20080226) MIME-Version: 1.0 To: Tejun Heo CC: James Bottomley , Mark Lord , Matthew Wilcox , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: ata_ram driver References: <20080222200951.GI16995@parisc-linux.org> <47BF3E54.9050609@rtr.ca> <47CFA9A6.2040506@gmail.com> <1204817301.3062.3.camel@localhost.localdomain> <47D08478.8010700@gmail.com> <1204848119.3062.94.camel@localhost.localdomain> <47D08892.3080209@gmail.com> <1204849353.3062.107.camel@localhost.localdomain> <47D08C32.8060907@gmail.com> In-Reply-To: <47D08C32.8060907@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: -4.4 (----) X-Spam-Report: SpamAssassin version 3.2.3 on srv5.dvmed.net summary: Content analysis details: (-4.4 points, 5.0 required) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Tejun Heo wrote: > James Bottomley wrote: >>> Yeap, sure. It's the combination of things that always made me put this >>> off. Is there a function I can call to just shutdown the host instead >>> of destroying it? >> Not really ... the process of unbinding the ULDs causes their remove >> methods to call shudown. It is possible to separate this in the ULDS; >> but the original design was to make remove and shutdown be similar for >> the very reason that if you're removing the driver with unflushed data >> in the cache, we'd really like it flushed (flush is called from >> shutdown) because you have no way to talk to the device after this >> without reinserting the driver. > > The problem is that libata EH and other stuff aren't ready to let go of > the SCSI host up until the last moment and that last moment can't be > moved before SCSI host destruction because shutdown sequence (flush and > spindown) requires live EH. I think this can be solved by shooting down > individual sdev's instead of destroying the scsi_host. I'm curious how the picture would change, if we used a scsi_host for each ata_host. Jeff