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=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 DB400C4167B for ; Mon, 7 Dec 2020 14:12:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AE3BA236FB for ; Mon, 7 Dec 2020 14:12:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727243AbgLGOMI (ORCPT ); Mon, 7 Dec 2020 09:12:08 -0500 Received: from verein.lst.de ([213.95.11.211]:42032 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727134AbgLGOMH (ORCPT ); Mon, 7 Dec 2020 09:12:07 -0500 Received: by verein.lst.de (Postfix, from userid 2407) id 7321567373; Mon, 7 Dec 2020 15:11:23 +0100 (CET) Date: Mon, 7 Dec 2020 15:11:23 +0100 From: Christoph Hellwig To: SelvaKumar S Cc: linux-nvme@lists.infradead.org, kbusch@kernel.org, axboe@kernel.dk, damien.lemoal@wdc.com, hch@lst.de, sagi@grimberg.me, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com, snitzer@redhat.com, selvajove@gmail.com, nj.shetty@samsung.com, joshi.k@samsung.com, javier.gonz@samsung.com, "Martin K. Petersen" , Bart Van Assche , Mikulas Patocka , linux-scsi@vger.kernel.org Subject: Re: [RFC PATCH v2 0/2] add simple copy support Message-ID: <20201207141123.GC31159@lst.de> References: <20201204094659.12732-1-selvakuma.s1@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201204094659.12732-1-selvakuma.s1@samsung.com> User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org So, I'm really worried about: a) a good use case. GC in f2fs or btrfs seem like good use cases, as does accelating dm-kcopyd. I agree with Damien that lifting dm-kcopyd to common code would also be really nice. I'm not 100% sure it should be a requirement, but it sure would be nice to have I don't think just adding an ioctl is enough of a use case for complex kernel infrastructure. b) We had a bunch of different attempts at SCSI XCOPY support form IIRC Martin, Bart and Mikulas. I think we need to pull them into this discussion, and make sure whatever we do covers the SCSI needs. On Fri, Dec 04, 2020 at 03:16:57PM +0530, SelvaKumar S wrote: > This patchset tries to add support for TP4065a ("Simple Copy Command"), > v2020.05.04 ("Ratified") > > The Specification can be found in following link. > https://nvmexpress.org/wp-content/uploads/NVM-Express-1.4-Ratified-TPs-1.zip > > This is an RFC. Looking forward for any feedbacks or other alternate > designs for plumbing simple copy to IO stack. > > Simple copy command is a copy offloading operation and is used to copy > multiple contiguous ranges (source_ranges) of LBA's to a single destination > LBA within the device reducing traffic between host and device. > > This implementation accepts destination, no of sources and arrays of > source ranges from application and attach it as payload to the bio and > submits to the device. > > Following limits are added to queue limits and are exposed in sysfs > to userspace > - *max_copy_sectors* limits the sum of all source_range length > - *max_copy_nr_ranges* limits the number of source ranges > - *max_copy_range_sectors* limit the maximum number of sectors > that can constitute a single source range. > > Changes from v1: > > 1. Fix memory leak in __blkdev_issue_copy > 2. Unmark blk_check_copy inline > 3. Fix line break in blk_check_copy_eod > 4. Remove p checks and made code more readable > 5. Don't use bio_set_op_attrs and remove op and set > bi_opf directly > 6. Use struct_size to calculate total_size > 7. Fix partition remap of copy destination > 8. Remove mcl,mssrl,msrc from nvme_ns > 9. Initialize copy queue limits to 0 in nvme_config_copy > 10. Remove return in QUEUE_FLAG_COPY check > 11. Remove unused OCFS > > SelvaKumar S (2): > block: add simple copy support > nvme: add simple copy support > > block/blk-core.c | 94 ++++++++++++++++++++++++++--- > block/blk-lib.c | 123 ++++++++++++++++++++++++++++++++++++++ > block/blk-merge.c | 2 + > block/blk-settings.c | 11 ++++ > block/blk-sysfs.c | 23 +++++++ > block/blk-zoned.c | 1 + > block/bounce.c | 1 + > block/ioctl.c | 43 +++++++++++++ > drivers/nvme/host/core.c | 87 +++++++++++++++++++++++++++ > include/linux/bio.h | 1 + > include/linux/blk_types.h | 15 +++++ > include/linux/blkdev.h | 15 +++++ > include/linux/nvme.h | 43 ++++++++++++- > include/uapi/linux/fs.h | 13 ++++ > 14 files changed, 461 insertions(+), 11 deletions(-) > > -- > 2.25.1 ---end quoted text---