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=-11.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 002DFC56204 for ; Wed, 21 Oct 2020 09:13:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8FBA321D7B for ; Wed, 21 Oct 2020 09:13:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=veeam.com header.i=@veeam.com header.b="D1RQaq6u" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437412AbgJUJNW (ORCPT ); Wed, 21 Oct 2020 05:13:22 -0400 Received: from mx4.veeam.com ([104.41.138.86]:56796 "EHLO mx4.veeam.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2437398AbgJUJNV (ORCPT ); Wed, 21 Oct 2020 05:13:21 -0400 X-Greylist: delayed 533 seconds by postgrey-1.27 at vger.kernel.org; Wed, 21 Oct 2020 05:13:21 EDT Received: from mail.veeam.com (spbmbx01.amust.local [172.17.17.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx4.veeam.com (Postfix) with ESMTPS id 8A0905C60C; Wed, 21 Oct 2020 12:04:26 +0300 (MSK) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=veeam.com; s=mx4; t=1603271066; bh=7pCinxh9CDdZ18baGj9Agc/InVPsneMyQj+wVyVjQ3I=; h=From:To:Subject:Date:From; b=D1RQaq6u5Gf6SP2mNiIVrCRlPSmaF6XvLmflwyZ7o4C8ia3u2i76fRSrT4beQCO05 yBr95+z13pJlPECDmYUR+W1eG8IdFt5fuPpnyP0aknKPqEapJX7GFwzvbP1K4dY+5J IGFPiinN/RxRhRuxEA2BpzaqYdBybPJt1hCyn/4M= Received: from prgdevlinuxpatch01.amust.local (172.24.14.5) by spbmbx01.amust.local (172.17.17.171) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.595.3; Wed, 21 Oct 2020 12:04:24 +0300 From: Sergei Shtepa To: , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH 0/2] block layer filter and block device snapshot module Date: Wed, 21 Oct 2020 12:04:07 +0300 Message-ID: <1603271049-20681-1-git-send-email-sergei.shtepa@veeam.com> X-Mailer: git-send-email 1.8.3.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [172.24.14.5] X-ClientProxiedBy: spbmbx01.amust.local (172.17.17.171) To spbmbx01.amust.local (172.17.17.171) X-EsetResult: clean, is OK X-EsetId: 37303A295605D26A677562 X-Veeam-MMEX: True Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Hello everyone! Requesting for your comments and suggestions. # blk-filter Block layer filter allows to intercept BIO requests to a block device. Interception is performed at the very beginning of the BIO request processing, and therefore does not affect the operation of the request processing queue. This also makes it possible to intercept requests from a specific block device, rather than from the entire disk. The logic of the submit_bio function has been changed - since the function execution results are not processed anywhere (except for swap and direct-io) the function won't return a value anymore. Now the submit_bio_direct() function is called whenever the result of the blk_qc_t function is required. submit_bio_direct() is not intercepted by the block layer filter. This is logical for swap and direct-io. Block layer filter allows you to enable and disable the filter driver on the fly. When a new block device is added, the filter driver can start filtering this device. When you delete a device, the filter can remove its own filter. The idea of multiple altitudes had to be abandoned in order to simplify implementation and make it more reliable. Different filter drivers can work simultaneously, but each on its own block device. # blk-snap We propose a new kernel module - blk-snap. This module implements snapshot and changed block tracking functionality. It is intended to create backup copies of any block devices without usage of device mapper. Snapshots are temporary and are destroyed after the backup process has finished. Changed block tracking allows for incremental and differential backup copies. blk-snap uses block layer filter. Block layer filter provides a callback to intercept bio-requests. If a block device disappears for whatever reason, send a synchronous request to remove the device from filtering. blk-snap kernel module is a product of a deep refactoring of the out-of-tree kernel veeamsnap kernel module (https://github.com/veeam/veeamsnap/): * all conditional compilation branches that served for the purpose of compatibility with older kernels have been removed; * linux kernel code style has been applied; * blk-snap mostly takes advantage of the existing kernel code instead of reinventing the wheel; * all redundant code (such as persistent cbt and snapstore collector) has been removed. Several important things are still have to be done: * refactor the module interface for interaction with a user-space code - it is already clear that the implementation of some calls can be improved. Your feedback would be greatly appreciated! Sergei Shtepa (2): Block layer filter - second version blk-snap - snapshots and change-tracking for block devices block/Kconfig | 11 + block/Makefile | 1 + block/blk-core.c | 52 +- block/blk-filter-internal.h | 29 + block/blk-filter.c | 286 ++++++ block/partitions/core.c | 14 +- drivers/block/Kconfig | 2 + drivers/block/Makefile | 1 + drivers/block/blk-snap/Kconfig | 24 + drivers/block/blk-snap/Makefile | 28 + drivers/block/blk-snap/big_buffer.c | 193 ++++ drivers/block/blk-snap/big_buffer.h | 24 + drivers/block/blk-snap/blk-snap-ctl.h | 190 ++++ drivers/block/blk-snap/blk_deferred.c | 566 +++++++++++ drivers/block/blk-snap/blk_deferred.h | 67 ++ drivers/block/blk-snap/blk_descr_file.c | 82 ++ drivers/block/blk-snap/blk_descr_file.h | 26 + drivers/block/blk-snap/blk_descr_mem.c | 66 ++ drivers/block/blk-snap/blk_descr_mem.h | 14 + drivers/block/blk-snap/blk_descr_multidev.c | 86 ++ drivers/block/blk-snap/blk_descr_multidev.h | 25 + drivers/block/blk-snap/blk_descr_pool.c | 190 ++++ drivers/block/blk-snap/blk_descr_pool.h | 38 + drivers/block/blk-snap/blk_redirect.c | 507 ++++++++++ drivers/block/blk-snap/blk_redirect.h | 73 ++ drivers/block/blk-snap/blk_util.c | 33 + drivers/block/blk-snap/blk_util.h | 33 + drivers/block/blk-snap/cbt_map.c | 210 +++++ drivers/block/blk-snap/cbt_map.h | 62 ++ drivers/block/blk-snap/common.h | 31 + drivers/block/blk-snap/ctrl_fops.c | 691 ++++++++++++++ drivers/block/blk-snap/ctrl_fops.h | 19 + drivers/block/blk-snap/ctrl_pipe.c | 562 +++++++++++ drivers/block/blk-snap/ctrl_pipe.h | 34 + drivers/block/blk-snap/ctrl_sysfs.c | 73 ++ drivers/block/blk-snap/ctrl_sysfs.h | 5 + drivers/block/blk-snap/defer_io.c | 397 ++++++++ drivers/block/blk-snap/defer_io.h | 39 + drivers/block/blk-snap/main.c | 82 ++ drivers/block/blk-snap/params.c | 58 ++ drivers/block/blk-snap/params.h | 29 + drivers/block/blk-snap/rangevector.c | 85 ++ drivers/block/blk-snap/rangevector.h | 31 + drivers/block/blk-snap/snapimage.c | 982 ++++++++++++++++++++ drivers/block/blk-snap/snapimage.h | 16 + drivers/block/blk-snap/snapshot.c | 225 +++++ drivers/block/blk-snap/snapshot.h | 17 + drivers/block/blk-snap/snapstore.c | 929 ++++++++++++++++++ drivers/block/blk-snap/snapstore.h | 68 ++ drivers/block/blk-snap/snapstore_device.c | 532 +++++++++++ drivers/block/blk-snap/snapstore_device.h | 63 ++ drivers/block/blk-snap/snapstore_file.c | 52 ++ drivers/block/blk-snap/snapstore_file.h | 15 + drivers/block/blk-snap/snapstore_mem.c | 91 ++ drivers/block/blk-snap/snapstore_mem.h | 20 + drivers/block/blk-snap/snapstore_multidev.c | 118 +++ drivers/block/blk-snap/snapstore_multidev.h | 22 + drivers/block/blk-snap/tracker.c | 449 +++++++++ drivers/block/blk-snap/tracker.h | 38 + drivers/block/blk-snap/tracking.c | 270 ++++++ drivers/block/blk-snap/tracking.h | 13 + drivers/block/blk-snap/version.h | 7 + fs/block_dev.c | 6 +- fs/direct-io.c | 2 +- fs/iomap/direct-io.c | 2 +- include/linux/bio.h | 4 +- include/linux/blk-filter.h | 76 ++ include/linux/genhd.h | 8 +- kernel/power/swap.c | 2 +- mm/page_io.c | 4 +- 70 files changed, 9074 insertions(+), 26 deletions(-) create mode 100644 block/blk-filter-internal.h create mode 100644 block/blk-filter.c create mode 100644 drivers/block/blk-snap/Kconfig create mode 100644 drivers/block/blk-snap/Makefile create mode 100644 drivers/block/blk-snap/big_buffer.c create mode 100644 drivers/block/blk-snap/big_buffer.h create mode 100644 drivers/block/blk-snap/blk-snap-ctl.h create mode 100644 drivers/block/blk-snap/blk_deferred.c create mode 100644 drivers/block/blk-snap/blk_deferred.h create mode 100644 drivers/block/blk-snap/blk_descr_file.c create mode 100644 drivers/block/blk-snap/blk_descr_file.h create mode 100644 drivers/block/blk-snap/blk_descr_mem.c create mode 100644 drivers/block/blk-snap/blk_descr_mem.h create mode 100644 drivers/block/blk-snap/blk_descr_multidev.c create mode 100644 drivers/block/blk-snap/blk_descr_multidev.h create mode 100644 drivers/block/blk-snap/blk_descr_pool.c create mode 100644 drivers/block/blk-snap/blk_descr_pool.h create mode 100644 drivers/block/blk-snap/blk_redirect.c create mode 100644 drivers/block/blk-snap/blk_redirect.h create mode 100644 drivers/block/blk-snap/blk_util.c create mode 100644 drivers/block/blk-snap/blk_util.h create mode 100644 drivers/block/blk-snap/cbt_map.c create mode 100644 drivers/block/blk-snap/cbt_map.h create mode 100644 drivers/block/blk-snap/common.h create mode 100644 drivers/block/blk-snap/ctrl_fops.c create mode 100644 drivers/block/blk-snap/ctrl_fops.h create mode 100644 drivers/block/blk-snap/ctrl_pipe.c create mode 100644 drivers/block/blk-snap/ctrl_pipe.h create mode 100644 drivers/block/blk-snap/ctrl_sysfs.c create mode 100644 drivers/block/blk-snap/ctrl_sysfs.h create mode 100644 drivers/block/blk-snap/defer_io.c create mode 100644 drivers/block/blk-snap/defer_io.h create mode 100644 drivers/block/blk-snap/main.c create mode 100644 drivers/block/blk-snap/params.c create mode 100644 drivers/block/blk-snap/params.h create mode 100644 drivers/block/blk-snap/rangevector.c create mode 100644 drivers/block/blk-snap/rangevector.h create mode 100644 drivers/block/blk-snap/snapimage.c create mode 100644 drivers/block/blk-snap/snapimage.h create mode 100644 drivers/block/blk-snap/snapshot.c create mode 100644 drivers/block/blk-snap/snapshot.h create mode 100644 drivers/block/blk-snap/snapstore.c create mode 100644 drivers/block/blk-snap/snapstore.h create mode 100644 drivers/block/blk-snap/snapstore_device.c create mode 100644 drivers/block/blk-snap/snapstore_device.h create mode 100644 drivers/block/blk-snap/snapstore_file.c create mode 100644 drivers/block/blk-snap/snapstore_file.h create mode 100644 drivers/block/blk-snap/snapstore_mem.c create mode 100644 drivers/block/blk-snap/snapstore_mem.h create mode 100644 drivers/block/blk-snap/snapstore_multidev.c create mode 100644 drivers/block/blk-snap/snapstore_multidev.h create mode 100644 drivers/block/blk-snap/tracker.c create mode 100644 drivers/block/blk-snap/tracker.h create mode 100644 drivers/block/blk-snap/tracking.c create mode 100644 drivers/block/blk-snap/tracking.h create mode 100644 drivers/block/blk-snap/version.h create mode 100644 include/linux/blk-filter.h -- 2.20.1