From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: struct request members, etc.. Date: Tue, 2 Jan 2007 13:34:18 +0100 Message-ID: <20070102123418.GW2483@kernel.dk> References: <200612112159.kBBLxmep005850@fire-2.osdl.org> <20061211141029.9a0b0376.akpm@osdl.org> <20061212103842.GA9619@lst.de> <20061212132600.GA19912@lst.de> <457EBAE3.6090609@panasas.com> <20070102120531.GB7032@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from brick.kernel.dk ([62.242.22.158]:28691 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964849AbXABMeW (ORCPT ); Tue, 2 Jan 2007 07:34:22 -0500 Content-Disposition: inline In-Reply-To: <20070102120531.GB7032@lst.de> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Christoph Hellwig Cc: Boaz Harrosh , linux-scsi@vger.kernel.org On Tue, Jan 02 2007, Christoph Hellwig wrote: > This gets a little offtopic for the original issue, so let's cut the Cc > list and change the subject. > > On Tue, Dec 12, 2006 at 04:21:23PM +0200, Boaz Harrosh wrote: > > I'm afraid this might not be enough because of code in drivers/ide/ide-cd.c. It does IO off of request->data. > > Only for FS requests, but we do BLOCK_PC requests here. ->buffer is the old style FS requests, ->data is never used for FS requests. BLOCK_PC requests should use just ->data, but I would not be surprised if ide-cd and others still map it to ->buffer. > > [background] > > pkt_generic_packet and ton of other places mainly cd(s), floppy(s), and > > other ide code paths, are using what I call BLACK requests. They put some > > data on request->buffer or request->data stick it in the Q and than advance > > on them later down the ladder. Remove of "buffer" and "data" from > > struct request will reveal all these places. At one time I had plans to do > > just that. But 1/2 way through I gave up, it is too risky, too much > > Hardware that I don't have, that needs checking. > > Removing this old code would definitly be worthwile, but I understand > that you don't want to get too deeply into the mess of floppy.c and the > old ide code :) I'd suggest moving everything to ->data, and get rid of ->buffer. You probably cannot remove both without complicating things, I'm not sure it's worth it. -- Jens Axboe