From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759391AbaIOVPf (ORCPT ); Mon, 15 Sep 2014 17:15:35 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:34424 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754601AbaIOVP1 (ORCPT ); Mon, 15 Sep 2014 17:15:27 -0400 Date: Mon, 15 Sep 2014 14:15:23 -0700 From: Christoph Hellwig To: Al Viro Cc: Milosz Tanski , linux-kernel@vger.kernel.org, Christoph Hellwig , linux-fsdevel@vger.kernel.org, linux-aio@kvack.org, Mel Gorman , Volker Lendecke , Tejun Heo , Jeff Moyer Subject: Re: [PATCH 1/7] Prepare for adding a new readv/writev with user flags. Message-ID: <20140915211523.GA5481@infradead.org> References: <20140915202828.GV7996@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140915202828.GV7996@ZenIV.linux.org.uk> 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 Mon, Sep 15, 2014 at 09:28:28PM +0100, Al Viro wrote: > On Mon, Sep 15, 2014 at 04:20:17PM -0400, Milosz Tanski wrote: > > Plumbing the flags argument through the vfs code so they can be passed down to > > __generic_file_(read/write)_iter function that do the acctual work. > > NAK. Put these flags into iocb, it'll be less noisy that way. Fine with me. My initial prototype had it in the iov_iter type field which is another possibility. But if we get rid of the explicit flags field and make it more invisible I'd really like to add a features field struct file_operations where instances can advertize that they support it (and other things like actual AIO support in the future) so that we won't have a situation like with AIO where we can submit I/O but it might actually still block anyway because lots of operations don't support it.