From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752597AbbKGKLM (ORCPT ); Sat, 7 Nov 2015 05:11:12 -0500 Received: from bombadil.infradead.org ([198.137.202.9]:40077 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752041AbbKGKKY (ORCPT ); Sat, 7 Nov 2015 05:10:24 -0500 Date: Sat, 7 Nov 2015 02:10:23 -0800 From: Christoph Hellwig To: mchristi@redhat.com Cc: linux-fsdevel@vger.kernel.org, dm-devel@redhat.com, linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, drbd-dev@lists.linbit.com Subject: Re: [RESEND RFC PATCH 00/32] separate operations from flags in the bio/request structs Message-ID: <20151107101023.GA12117@infradead.org> References: <1446674909-5371-1-git-send-email-mchristi@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1446674909-5371-1-git-send-email-mchristi@redhat.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.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 On Wed, Nov 04, 2015 at 04:07:57PM -0600, mchristi@redhat.com wrote: > Known issues: > - REQ_FLUSH is still a flag, but should probably be a operation. > For lower level drivers like SCSI where we only get a flush, it makes > more sense to be a operation. However, upper layers like filesystems > can send down flushes with writes, so it is more of a flag for them. > I am still working on this. Actually it should be both. REQ_OP_FLUSH for a real flush operation, and a REQ_PREFLUSH bio flag that the request layer will sequence into an actual write an a flush operation.