From patchwork Fri Aug 4 13:13:09 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13341811 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 66786C00528 for ; Fri, 4 Aug 2023 13:14:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229510AbjHDNOZ (ORCPT ); Fri, 4 Aug 2023 09:14:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56002 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229825AbjHDNOY (ORCPT ); Fri, 4 Aug 2023 09:14:24 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9114446B1 for ; Fri, 4 Aug 2023 06:13:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1691154815; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=YdazvjmGmZmgj91lOlAbSLPEx72pSHsRbgB1k8qsYaw=; b=BI/pbSMThgJej+S97pcam1JNB/NaFoeyxq7BeaLw6cwn72DPoteVHZG8RSrxUSatRHzR/j mkLKEjcKh/xnPGs+pVY0iK4zSBWyhRdCSpVWcPXg4mcsJRjuOTP+QjhPKYFbBaIRDQEV4U Cu1KCTaot+QPiQSBCWjt41kCyeYH8Q4= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-370-MjUsA69JPfGO44TxO2PFBQ-1; Fri, 04 Aug 2023 09:13:32 -0400 X-MC-Unique: MjUsA69JPfGO44TxO2PFBQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 274C180006E; Fri, 4 Aug 2023 13:13:32 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.42.28.131]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3DE8F112132D; Fri, 4 Aug 2023 13:13:30 +0000 (UTC) From: David Howells To: Ilya Dryomov , Xiubo Li Cc: David Howells , Jeff Layton , Dongsheng Yang , ceph-devel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH 00/18] ceph, rbd: Collapse all the I/O types down to something iov_iter-based Date: Fri, 4 Aug 2023 14:13:09 +0100 Message-ID: <20230804131327.2574082-1-dhowells@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Hi Ilya, Xiubo, [!] NOTE: This is a preview of a work in progress and doesn't yet fully compile, let alone actually work! Here are some patches that (mostly) collapse the different I/O types (PAGES, PAGELIST, BVECS, BIO) down to a single one. I added a new type, ceph_databuf, to make this easier. The page list is attached to that as a bio_vec[] with an iov_iter, but could also be some other type supported by the iov_iter. The iov_iter defines the data or buffer to be used. I have an additional iov_iter type implemented that allows use of a straight folio[] or page[] instead of a bio_vec[] that I can deploy if that proves more useful. The conversion isn't quite complete: (1) rbd is done; BVECS and BIO types are replaced with ceph_databuf. (2) ceph_osd_linger_request::preply_pages needs switching over to a ceph_databuf, but I haven't yet managed to work out how the pages that handle_watch_notify() sticks in there come about. (3) I haven't altered data transmission in net/ceph/messenger*.c yet. The aim is to reduce it to a single sendmsg() call for each ceph_msg_data struct, using the iov_iter therein. (4) The data reception routines in net/ceph/messenger*.c also need modifying to pass each ceph_msg_data::iter to recvmsg() in turn. (5) It might be possible to merge struct ceph_databuf into struct ceph_msg_data and eliminate the former. (6) fs/ceph/ still needs some work to clean up the use of page arrays. (7) I would like to change front and middle buffers with a ceph_databuf, vmapping them when we need to access them. I added a kmap_ceph_databuf_page() macro and used that to get a page and use kmap_local_page() on it to hide the bvec[] inside to make it easier to replace. Anyway, if anyone has any thoughts... I've pushed the patches here also: https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/log/?h=iov-extract David David Howells (18): iov_iter: Add function to see if buffer is all zeros ceph: Rename alignment to offset ceph: Add a new data container type, ceph_databuf ceph: Convert ceph_mds_request::r_pagelist to a databuf rbd: Use ceph_databuf for rbd_obj_read_sync() ceph: Change ceph_osdc_call()'s reply to a ceph_databuf ceph: Unexport osd_req_op_cls_request_data_pages() ceph: Remove osd_req_op_cls_response_data_pages() ceph: Convert notify_id_pages to a ceph_databuf rbd: Switch from using bvec_iter to iov_iter ceph: Remove bvec and bio data container types ceph: Convert some page arrays to ceph_databuf ceph: Convert users of ceph_pagelist to ceph_databuf ceph: Remove ceph_pagelist ceph: Convert ceph_osdc_notify() reply to ceph_databuf ceph: Remove CEPH_OS_DATA_TYPE_PAGES and its attendant helpers ceph: Remove CEPH_MSG_DATA_PAGES and its helpers ceph: Don't use data_pages drivers/block/rbd.c | 645 ++++++++++---------------------- fs/ceph/acl.c | 39 +- fs/ceph/addr.c | 18 +- fs/ceph/file.c | 157 ++++---- fs/ceph/inode.c | 85 ++--- fs/ceph/locks.c | 23 +- fs/ceph/mds_client.c | 134 ++++--- fs/ceph/mds_client.h | 2 +- fs/ceph/super.h | 8 +- fs/ceph/xattr.c | 68 ++-- include/linux/ceph/databuf.h | 65 ++++ include/linux/ceph/messenger.h | 141 +------ include/linux/ceph/osd_client.h | 97 ++--- include/linux/ceph/pagelist.h | 72 ---- include/linux/uio.h | 1 + lib/iov_iter.c | 22 ++ net/ceph/Makefile | 5 +- net/ceph/cls_lock_client.c | 40 +- net/ceph/databuf.c | 149 ++++++++ net/ceph/messenger.c | 376 +------------------ net/ceph/osd_client.c | 430 +++++++-------------- net/ceph/pagelist.c | 171 --------- 22 files changed, 876 insertions(+), 1872 deletions(-) create mode 100644 include/linux/ceph/databuf.h delete mode 100644 include/linux/ceph/pagelist.h create mode 100644 net/ceph/databuf.c delete mode 100644 net/ceph/pagelist.c