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=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,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 3C0ACC4742C for ; Mon, 2 Nov 2020 16:55:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D46C122277 for ; Mon, 2 Nov 2020 16:55:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="uv8V4Qf4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727684AbgKBQzT (ORCPT ); Mon, 2 Nov 2020 11:55:19 -0500 Received: from userp2120.oracle.com ([156.151.31.85]:59744 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727267AbgKBQzS (ORCPT ); Mon, 2 Nov 2020 11:55:18 -0500 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 0A2GipSt125557; Mon, 2 Nov 2020 16:55:09 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2020-01-29; bh=fpbCG2OtM1Up+kxO9vDyx7qYKStM0Y5WPsRxKyG/cJI=; b=uv8V4Qf4EQB9/QknsVF9Fi+L5IzOM4Wwg0EdpgdoVrzuOAiw0U7kWc2aDPwhz/5P2nfO zvgqR+c6RnG5U434+RUrVh30FYJx3U/3jjyrpCN7OA6PQx844u6C0NeBdcauoa4c78Hm eCakjsdk+baDOOmmLcq41BgFp5XKu29bePRp3OhdeSzcD890v2BVLKbWTrHBVMC2MZwz t/SwcXA+DTQikvbYJBR/QOPIuwAg4gf5sdjD3j+xOFswEV7ZLSzRtPDgmTCzmQcFK6+7 2i2YRwz8GcfhqIvmeQ/U+6ORLu54UIuwVlOFNsf5VCztdUPKkKxrNNNAG8SPWet/tB1x hQ== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by userp2120.oracle.com with ESMTP id 34hhw2d26h-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 02 Nov 2020 16:55:08 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 0A2Gijnr188226; Mon, 2 Nov 2020 16:55:08 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by aserp3030.oracle.com with ESMTP id 34jf46sw14-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 02 Nov 2020 16:55:07 +0000 Received: from abhmp0006.oracle.com (abhmp0006.oracle.com [141.146.116.12]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 0A2Gt4LQ017674; Mon, 2 Nov 2020 16:55:04 GMT Received: from localhost (/67.169.218.210) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 02 Nov 2020 08:55:04 -0800 Date: Mon, 2 Nov 2020 08:55:02 -0800 From: "Darrick J. Wong" To: Naohiro Aota Cc: linux-btrfs@vger.kernel.org, dsterba@suse.com, hare@suse.com, linux-fsdevel@vger.kernel.org, Christoph Hellwig , linux-xfs@vger.kernel.org Subject: Re: [PATCH v9 02/41] iomap: support REQ_OP_ZONE_APPEND Message-ID: <20201102165502.GA7123@magnolia> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9793 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 suspectscore=1 mlxscore=0 bulkscore=0 malwarescore=0 mlxlogscore=999 phishscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2011020129 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9793 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 malwarescore=0 mlxscore=0 suspectscore=1 clxscore=1011 priorityscore=1501 impostorscore=0 spamscore=0 lowpriorityscore=0 mlxlogscore=999 phishscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2011020129 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Fri, Oct 30, 2020 at 10:51:09PM +0900, Naohiro Aota wrote: > A ZONE_APPEND bio must follow hardware restrictions (e.g. not exceeding > max_zone_append_sectors) not to be split. bio_iov_iter_get_pages builds > such restricted bio using __bio_iov_append_get_pages if bio_op(bio) == > REQ_OP_ZONE_APPEND. > > To utilize it, we need to set the bio_op before calling > bio_iov_iter_get_pages(). This commit introduces IOMAP_F_ZONE_APPEND, so > that iomap user can set the flag to indicate they want REQ_OP_ZONE_APPEND > and restricted bio. Would you mind putting this paragraph in a comment before the bio_iov_iter_get_pages call? I could easily see someone (i.e. 2021 me) forgetting there's a data dependency and breaking this. > Cc: Christoph Hellwig > Cc: "Darrick J. Wong" > Cc: linux-xfs@vger.kernel.org > Signed-off-by: Naohiro Aota > --- > fs/iomap/direct-io.c | 22 ++++++++++++++++------ > include/linux/iomap.h | 1 + > 2 files changed, 17 insertions(+), 6 deletions(-) > > diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c > index c1aafb2ab990..e534703c5594 100644 > --- a/fs/iomap/direct-io.c > +++ b/fs/iomap/direct-io.c > @@ -210,6 +210,7 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length, > struct bio *bio; > bool need_zeroout = false; > bool use_fua = false; > + bool zone_append = false; > int nr_pages, ret = 0; > size_t copied = 0; > size_t orig_count; > @@ -241,6 +242,8 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length, > use_fua = true; > } > > + zone_append = ; > + > /* > * Save the original count and trim the iter to just the extent we > * are operating on right now. The iter will be re-expanded once > @@ -278,6 +281,19 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length, > bio->bi_private = dio; > bio->bi_end_io = iomap_dio_bio_end_io; > > + if (dio->flags & IOMAP_DIO_WRITE) { > + bio->bi_opf = (zone_append ? REQ_OP_ZONE_APPEND : REQ_OP_WRITE) | > + REQ_SYNC | REQ_IDLE; > + if (use_fua) > + bio->bi_opf |= REQ_FUA; > + else > + dio->flags &= ~IOMAP_DIO_WRITE_FUA; > + } else { > + WARN_ON_ONCE(zone_append); > + > + bio->bi_opf = REQ_OP_READ; > + } Also, I think this should be hoisted into a separate helper to return bi_opf rather than making iomap_dio_bio_actor even longer... /* * Figure out the bio's operation flags from the dio request, the * mapping, and whether or not we want FUA. Note that we can end up * clearing the WRITE_FUA flag in the dio request. */ static inline unsigned int iomap_dio_bio_opflags(struct iomap_dio *dio, struct iomap *iomap, bool use_fua) { unsigned int opflags = REQ_SYNC | REQ_IDLE; if (!(dio->flags & IOMAP_DIO_WRITE)) { WARN_ON_ONCE(iomap->flags & IOMAP_F_ZONE_APPEND); return REQ_OP_READ; } if (iomap->flags & IOMAP_F_ZONE_APPEND) opflags |= REQ_OP_ZONE_APPEND; else opflags |= REQ_OP_WRITE; if (use_fua) opflags |= REQ_FUA; else dio->flags &= ~IOMAP_DIO_WRITE_FUA; return opflags; } /* * Set the operation flags early so that bio_iov_iter_get_pages can * set up the page vector appropriately for a ZONE_APPEND operation. */ bio->bi_opf = iomap_dio_bio_opflags(dio, iomap, use_fua); ret = bio_iov_iter_get_pages(bio, dio->submit.iter); if (unlikely(ret)) { --D > + > ret = bio_iov_iter_get_pages(bio, dio->submit.iter); > if (unlikely(ret)) { > /* > @@ -292,14 +308,8 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length, > > n = bio->bi_iter.bi_size; > if (dio->flags & IOMAP_DIO_WRITE) { > - bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE; > - if (use_fua) > - bio->bi_opf |= REQ_FUA; > - else > - dio->flags &= ~IOMAP_DIO_WRITE_FUA; > task_io_account_write(n); > } else { > - bio->bi_opf = REQ_OP_READ; > if (dio->flags & IOMAP_DIO_DIRTY) > bio_set_pages_dirty(bio); > } > diff --git a/include/linux/iomap.h b/include/linux/iomap.h > index 4d1d3c3469e9..1bccd1880d0d 100644 > --- a/include/linux/iomap.h > +++ b/include/linux/iomap.h > @@ -54,6 +54,7 @@ struct vm_fault; > #define IOMAP_F_SHARED 0x04 > #define IOMAP_F_MERGED 0x08 > #define IOMAP_F_BUFFER_HEAD 0x10 > +#define IOMAP_F_ZONE_APPEND 0x20 > > /* > * Flags set by the core iomap code during operations: > -- > 2.27.0 >