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 C77F3C3DA6B for ; Sat, 27 Aug 2022 07:08:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232403AbiH0HIF (ORCPT ); Sat, 27 Aug 2022 03:08:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37754 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231469AbiH0HIE (ORCPT ); Sat, 27 Aug 2022 03:08:04 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 10E1986FF6; Sat, 27 Aug 2022 00:08:03 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id A18AF6100A; Sat, 27 Aug 2022 07:08:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B027CC433C1; Sat, 27 Aug 2022 07:08:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1661584082; bh=p0KRSMvvBhsJs0c03pHNWDIW9Qt/EnRrmOnfStK+zqg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=uLvlkjUnktj26RRTEJeF29+/+JHbO8XAS/9V4Wiki8lnjsjbLKVT97mLLImiN+62c +EpOM247AJ37EeTTDfES3liBnoAa62LtOVdbsIQCqAZwgFhq/a3G9Q8kzPhPMxXk9m rI9+KpZadUhXkoHHIFuHm87iZR3ytO2piFQYvBFmhjQ2mNF3wkkcgxI7suT8JRZ2A+ DVAmVSkYyz4wKEJ+nVPeqplcAYgBznkFuKsC7aSdTh8p6ucLWwQ57+nxuAjSNnTHyK qfHYoDrflvFMbCIYPiKxfJG6x9FoBVXZzhDJ9CEuhsJ3Awv6lodlmAAmAtepC2dyQo AvX8PSILJ/IBA== Date: Sat, 27 Aug 2022 00:07:59 -0700 From: Eric Biggers To: Jeff Layton Cc: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-xfs@vger.kernel.org, linux-api@vger.kernel.org, linux-fscrypt@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, Keith Busch Subject: Re: [PATCH v4 0/9] make statx() return DIO alignment information Message-ID: References: <20220722071228.146690-1-ebiggers@kernel.org> <3543250c8157c3e0e7e410b268121e4d7d3e9bc2.camel@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3543250c8157c3e0e7e410b268121e4d7d3e9bc2.camel@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Fri, Aug 26, 2022 at 01:19:37PM -0400, Jeff Layton wrote: > On Fri, 2022-07-22 at 00:12 -0700, Eric Biggers wrote: > > This patchset makes the statx() system call return direct I/O (DIO) > > alignment information. This allows userspace to easily determine > > whether a file supports DIO, and if so with what alignment restrictions. > > > > Patch 1 adds the basic VFS support for STATX_DIOALIGN. Patch 2 wires it > > up for all block device files. The remaining patches wire it up for > > regular files on ext4, f2fs, and xfs. Support for regular files on > > other filesystems can be added later. > > > > I've also written a man-pages patch, which I'm sending separately. > > > > Note, f2fs has one corner case where DIO reads are allowed but not DIO > > writes. The proposed statx fields can't represent this. My proposal > > (patch 6) is to just eliminate this case, as it seems much too weird. > > But I'd appreciate any feedback on that part. > > > > This patchset applies to v5.19-rc7. > > > > Changed v3 => v4: > > - Added xfs support. > > > > - Moved the helper function for block devices into block/bdev.c. > > > > - Adjusted the ext4 patch to not introduce a bug where misaligned DIO > > starts being allowed on encrypted files when it gets combined with > > the patch "iomap: add support for dma aligned direct-io" that is > > queued in the block tree for 5.20. > > > > - Made a simplification in fscrypt_dio_supported(). > > > > Changed v2 => v3: > > - Dropped the stx_offset_align_optimal field, since its purpose > > wasn't clearly distinguished from the existing stx_blksize. > > > > - Renamed STATX_IOALIGN to STATX_DIOALIGN, to reflect the new focus > > on DIO only. > > > > - Similarly, renamed stx_{mem,offset}_align_dio to > > stx_dio_{mem,offset}_align, to reflect the new focus on DIO only. > > > > - Wired up STATX_DIOALIGN on block device files. > > > > Changed v1 => v2: > > - No changes. > > > > Eric Biggers (9): > > statx: add direct I/O alignment information > > vfs: support STATX_DIOALIGN on block devices > > fscrypt: change fscrypt_dio_supported() to prepare for STATX_DIOALIGN > > ext4: support STATX_DIOALIGN > > f2fs: move f2fs_force_buffered_io() into file.c > > f2fs: don't allow DIO reads but not DIO writes > > f2fs: simplify f2fs_force_buffered_io() > > f2fs: support STATX_DIOALIGN > > xfs: support STATX_DIOALIGN > > > > block/bdev.c | 25 ++++++++++++++++++++ > > fs/crypto/inline_crypt.c | 49 +++++++++++++++++++-------------------- > > fs/ext4/ext4.h | 1 + > > fs/ext4/file.c | 37 ++++++++++++++++++++--------- > > fs/ext4/inode.c | 36 ++++++++++++++++++++++++++++ > > fs/f2fs/f2fs.h | 45 ----------------------------------- > > fs/f2fs/file.c | 45 ++++++++++++++++++++++++++++++++++- > > fs/stat.c | 14 +++++++++++ > > fs/xfs/xfs_iops.c | 9 +++++++ > > include/linux/blkdev.h | 4 ++++ > > include/linux/fscrypt.h | 7 ++---- > > include/linux/stat.h | 2 ++ > > include/uapi/linux/stat.h | 4 +++- > > 13 files changed, 190 insertions(+), 88 deletions(-) > > > > base-commit: ff6992735ade75aae3e35d16b17da1008d753d28 > > Hi Eric, > > Can I ask what your plans are with this set? I didn't see it in > linux-next yet, so I wasn't sure when you were looking to get it merged. > I'm working on patches to add a new statx field for the i_version > counter as well and I want to make sure that our work doesn't collide. > I've just sent v5. I guess I'll try to get it merged for 6.1. We were a bit stuck on the read-only DIO issue. All things considered though, including that Christoph thinks it's possible for f2fs to support DIO writes on zoned block devices, I'm willing to bet that read-only DIO doesn't really matter enough for it to be worth it to add a direction field to STATX_DIOALIGN (which would make it harder to use STATX_DIOALIGN, as the field would always have to be checked). - Eric