From patchwork Tue Oct 31 13:54:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fiona Ebner X-Patchwork-Id: 13441561 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 91C00C4167D for ; Tue, 31 Oct 2023 13:58:10 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qxpEd-0001FR-FM; Tue, 31 Oct 2023 09:56:47 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qxpE0-0000W2-Rs; Tue, 31 Oct 2023 09:56:11 -0400 Received: from proxmox-new.maurer-it.com ([94.136.29.106]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qxpDw-0000lQ-Uv; Tue, 31 Oct 2023 09:56:08 -0400 Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id BD63A42A70; Tue, 31 Oct 2023 14:55:50 +0100 (CET) From: Fiona Ebner To: qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, armbru@redhat.com, eblake@redhat.com, hreitz@redhat.com, kwolf@redhat.com, vsementsov@yandex-team.ru, jsnow@redhat.com, den@virtuozzo.com, t.lamprecht@proxmox.com, alexander.ivanov@virtuozzo.com Subject: [PATCH v4 00/10] mirror: allow switching from background to active mode Date: Tue, 31 Oct 2023 14:54:21 +0100 Message-Id: <20231031135431.393137-1-f.ebner@proxmox.com> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Received-SPF: pass client-ip=94.136.29.106; envelope-from=f.ebner@proxmox.com; helo=proxmox-new.maurer-it.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Changes in v4: * add an iotest for the new functionality * set actively_synced to false when setting dirty bitmap in bdrv_mirror_top_do_write * add comments describing requirements for accessing copy_mode and actively_synced field * add global state code annotation and comment about assumptions in mirror_change method * add comment that change callback can be called before the job coroutine is running * fix typo in QAPI description Changes in v3: * unlock the job mutex when calling the new block job driver 'query' handler * squash patch adapting iotest output into patch that changes the output * turn accesses to copy_mode and actively_synced atomic * slightly rework error handling in mirror_change Changes in v2: * move bitmap to filter which allows to avoid draining when changing the copy mode * add patch to determine copy_to_target only once * drop patches returning redundant information upon query * update QEMU version in QAPI * update indentation in QAPI * update indentation in QAPI (like in a937b6aa73 ("qapi: Reformat doc comments to conform to current conventions")) * add patch to adapt iotest output Discussion of v3: https://lists.nongnu.org/archive/html/qemu-devel/2023-10/msg04026.html Discussion of v2: https://lists.nongnu.org/archive/html/qemu-devel/2023-10/msg02290.html Discussion of v1: https://lists.nongnu.org/archive/html/qemu-devel/2023-02/msg07216.html With active mode, the guest write speed is limited by the synchronous writes to the mirror target. For this reason, management applications might want to start out in background mode and only switch to active mode later, when certain conditions are met. This series adds a block-job-change QMP command to achieve that, as well as job-type-specific information when querying block jobs, which can be used to decide when the switch should happen. For now, only the direction background -> active is supported. The information added upon querying is whether the target is actively synced, the total data sent, and the remaining dirty bytes. Initially, I tried to go for a more general 'job-change' command, but to avoid mutual inclusion of block-core.json and job.json, more preparation would be required. More details described here: https://lists.nongnu.org/archive/html/qemu-devel/2023-10/msg02993.html Fiona Ebner (10): blockjob: introduce block-job-change QMP command block/mirror: set actively_synced even after the job is ready block/mirror: move dirty bitmap to filter block/mirror: determine copy_to_target only once mirror: implement mirror_change method qapi/block-core: use JobType for BlockJobInfo's type qapi/block-core: turn BlockJobInfo into a union blockjob: query driver-specific info via a new 'query' driver method mirror: return mirror-specific information upon query iotests: add test for changing mirror's copy_mode block/mirror.c | 131 ++++++++---- block/monitor/block-hmp-cmds.c | 4 +- blockdev.c | 14 ++ blockjob.c | 28 ++- include/block/blockjob.h | 11 + include/block/blockjob_int.h | 12 ++ job.c | 1 + qapi/block-core.json | 59 +++++- qapi/job.json | 4 +- tests/qemu-iotests/109.out | 24 +-- .../tests/mirror-change-copy-mode | 192 ++++++++++++++++++ .../tests/mirror-change-copy-mode.out | 5 + 12 files changed, 429 insertions(+), 56 deletions(-) create mode 100755 tests/qemu-iotests/tests/mirror-change-copy-mode create mode 100644 tests/qemu-iotests/tests/mirror-change-copy-mode.out