From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D5EB4C43219 for ; Thu, 20 Jan 2022 08:30:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1359269AbiATIa6 (ORCPT ); Thu, 20 Jan 2022 03:30:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33798 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240169AbiATIaZ (ORCPT ); Thu, 20 Jan 2022 03:30:25 -0500 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8E12BC06175A; Thu, 20 Jan 2022 00:30:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=4YLv12vaH5SBxgO/VH+IFNLxgK8TDHDUDIGloGpzq0o=; b=Q3dHqDRR7It61x+wYLIdNp05S/ u6VPSwFrw0IY2CI7N3H2ifaUZ68axyBfGF181H5kwwOhrafeJWImtn1gRt+0d0IBDN99yIfge1PJG hP9BReWxiFQ3g/pJxQ+RMonEZ0AjNLRvDSKEXm1JMv2oKnyCo1oU5TnOZAmkQQ0dQbhJeODMJJSov Jh1B1T+BW+K3aI5Oxe7eJZnwq95ZaW94LU/r4X7TmJNogOB+WlE3woZv0Oiko+7qp6E/nli6pMZFI vMTM9Wn0SwZIO73GEuuNAmtZiXw0BILywxroF0GSo4m8pPMgSas9xV2RAeoAbgk8cQ3qeOPcLohCa 1cV9RIUA==; Received: from hch by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1nASpr-009lmb-O7; Thu, 20 Jan 2022 08:30:23 +0000 Date: Thu, 20 Jan 2022 00:30:23 -0800 From: Christoph Hellwig To: Eric Biggers Cc: linux-fscrypt@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-xfs@vger.kernel.org, Christoph Hellwig , Dave Chinner , "Darrick J . Wong" , Theodore Ts'o , Jaegeuk Kim , Chao Yu Subject: Re: [PATCH v10 0/5] add support for direct I/O with fscrypt using blk-crypto Message-ID: References: <20220120071215.123274-1-ebiggers@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220120071215.123274-1-ebiggers@kernel.org> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, Jan 19, 2022 at 11:12:10PM -0800, Eric Biggers wrote: > > Given the above, as far as I know the only remaining objection to this > patchset would be that DIO constraints aren't sufficiently discoverable > by userspace. Now, to put this in context, this is a longstanding issue > with all Linux filesystems, except XFS which has XFS_IOC_DIOINFO. It's > not specific to this feature, and it doesn't actually seem to be too > important in practice; many other filesystem features place constraints > on DIO, and f2fs even *only* allows fully FS block size aligned DIO. > (And for better or worse, many systems using fscrypt already have > out-of-tree patches that enable DIO support, and people don't seem to > have trouble with the FS block size alignment requirement.) It might make sense to use this as an opportunity to implement XFS_IOC_DIOINFO for ext4 and f2fs. > I plan to propose a new generic ioctl to address the issue of DIO > constraints being insufficiently discoverable. But until then, I'm > wondering if people are willing to consider this patchset again, or > whether it is considered blocked by this issue alone. (And if this > patchset is still unacceptable, would it be acceptable with f2fs support > only, given that f2fs *already* only allows FS block size aligned DIO?) I think the patchset looks fine, but I'd really love to have a way for the alignment restrictions to be discoverable from the start.