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 X-Spam-Level: X-Spam-Status: No, score=-16.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6D3E4C433DB for ; Thu, 21 Jan 2021 19:08:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1ADC2221E7 for ; Thu, 21 Jan 2021 19:08:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726823AbhAUTHv (ORCPT ); Thu, 21 Jan 2021 14:07:51 -0500 Received: from mail.kernel.org ([198.145.29.99]:38140 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726685AbhAUTHU (ORCPT ); Thu, 21 Jan 2021 14:07:20 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4A56023A1C; Thu, 21 Jan 2021 18:55:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1611255336; bh=+DrtLBHO7amWTEFFTg5kzH26MSXx3tdxRE/GkKFbq9A=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=VPWVGu5M7LsAQooXzVq9fFvuxwNYhFDiNV8CsSqnP1ZQglY+UcLwVZIbVY/WuwAlw OgUgRWwKVyKpkyKCckqwmchAJUlWgEQ/+bU71mBGMIJ/jQfMvej1m2eXpiN583Rfby zXZjX0SHmOhCf4mWn3fIuAijWie9fgjHnhuWyzhg/2Do97QcOuMZieotOKCc1BD5u6 zCRHhE87rLawAauGhjLMqSEVOJ9gpqErBCuExtVGfbozLQSfZRYh4bEFc3cMAU93WR lo9on7fsuriHrXJd97tgQ10b4+vwRkdRtWPPpRGxllPweuHqXoYvRUCUhUJN8zbD/O C2gEbNTr7Vvrg== Date: Thu, 21 Jan 2021 10:55:35 -0800 From: "Darrick J. Wong" To: Christoph Hellwig Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, avi@scylladb.com Subject: Re: [PATCH 10/11] iomap: add a IOMAP_DIO_OVERWRITE_ONLY flag Message-ID: <20210121185535.GD1282159@magnolia> References: <20210121085906.322712-1-hch@lst.de> <20210121085906.322712-11-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210121085906.322712-11-hch@lst.de> Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Thu, Jan 21, 2021 at 09:59:05AM +0100, Christoph Hellwig wrote: > Add a flag to signal an only pure overwrites are allowed. > > Signed-off-by: Christoph Hellwig > --- > fs/iomap/direct-io.c | 7 +++++++ > include/linux/iomap.h | 8 ++++++++ > 2 files changed, 15 insertions(+) > > diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c > index 947343730e2c93..65d32364345d22 100644 > --- a/fs/iomap/direct-io.c > +++ b/fs/iomap/direct-io.c > @@ -485,6 +485,13 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, > iomap_flags |= IOMAP_NOWAIT; > } > > + if (dio_flags & IOMAP_DIO_OVERWRITE_ONLY) { > + ret = -EAGAIN; > + if (pos >= dio->i_size || pos + count > dio->i_size) > + goto out_free_dio; > + iomap_flags |= IOMAP_OVERWRITE_ONLY; > + } > + > ret = filemap_write_and_wait_range(mapping, pos, end); > if (ret) > goto out_free_dio; > diff --git a/include/linux/iomap.h b/include/linux/iomap.h > index be4e1e1e01e801..cfa20afd7d5b87 100644 > --- a/include/linux/iomap.h > +++ b/include/linux/iomap.h > @@ -122,6 +122,7 @@ struct iomap_page_ops { > #define IOMAP_FAULT (1 << 3) /* mapping for page fault */ > #define IOMAP_DIRECT (1 << 4) /* direct I/O */ > #define IOMAP_NOWAIT (1 << 5) /* do not block */ > +#define IOMAP_OVERWRITE_ONLY (1 << 6) /* purely overwrites allowed */ "only pure overwrites allowed" ? With that fixed, Reviewed-by: Darrick J. Wong --D > > struct iomap_ops { > /* > @@ -262,6 +263,13 @@ struct iomap_dio_ops { > */ > #define IOMAP_DIO_FORCE_WAIT (1 << 0) > > +/* > + * Do not allocate blocks or zero partial blocks, but instead fall back to > + * the caller by returning -EAGAIN. Used to optimize direct I/O writes that > + * are not aligned to the file system block size. > + */ > +#define IOMAP_DIO_OVERWRITE_ONLY (1 << 1) > + > ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, > const struct iomap_ops *ops, const struct iomap_dio_ops *dops, > unsigned int dio_flags); > -- > 2.29.2 >