Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757236AbYABUSQ (ORCPT ); Wed, 2 Jan 2008 15:18:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752893AbYABUSA (ORCPT ); Wed, 2 Jan 2008 15:18:00 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:48936 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752786AbYABUR7 (ORCPT ); Wed, 2 Jan 2008 15:17:59 -0500 Date: Wed, 2 Jan 2008 20:17:34 +0000 From: Christoph Hellwig To: Linus Torvalds Cc: Matthew Wilcox , James Bottomley , Ingo Molnar , linux-kernel@vger.kernel.org, Andrew Morton Subject: Re: [patch] scsi: revert "[SCSI] Get rid of scsi_cmnd->done" Message-ID: <20080102201734.GA13881@infradead.org> References: <20080102162534.GA4041@elte.hu> <1199292381.3258.32.camel@localhost.localdomain> <20080102194030.GC11638@parisc-linux.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1147 Lines: 26 On Wed, Jan 02, 2008 at 11:57:10AM -0800, Linus Torvalds wrote: > > > On Wed, 2 Jan 2008, Matthew Wilcox wrote: > > > > sd_done and sr_done are called for REQ_TYPE_FS -- if the request comes > > in through one of the SG interfaces, we call scsi_setup_blk_pc_cmnd() > > which sets the ->done callback to scsi_blk_pc_done. > > Why do you think that REQ_TYPE_BLOCK_PC has anything to do with SG? > > It has *nothing* to do with SG, and anybody who uses SG in this day and > age on a block device is just crazy. I think you misunderstood Matthew here. REQ_TYPE_BLOCK_PC is indeed used by any kind of SG_IO or similar passthrough no matter where it originates. And exactly because REQ_TYPE_BLOCK_PC are entirely passthru the actual driver (sd, sr or sg) is not doing the actual command completion but it's handled in the scsi layer because it's exactly the same no matter what driver it came on. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/