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=ham 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 2BC93C4363A for ; Wed, 21 Oct 2020 09:04:31 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 70A2822250 for ; Wed, 21 Oct 2020 09:04:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=veeam.com header.i=@veeam.com header.b="D1RQaq6u" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 70A2822250 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=veeam.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id D42C76B0062; Wed, 21 Oct 2020 05:04:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CF38D6B0068; Wed, 21 Oct 2020 05:04:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BBEC06B006C; Wed, 21 Oct 2020 05:04:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0101.hostedemail.com [216.40.44.101]) by kanga.kvack.org (Postfix) with ESMTP id 90FF86B0062 for ; Wed, 21 Oct 2020 05:04:29 -0400 (EDT) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 2DE269437 for ; Wed, 21 Oct 2020 09:04:29 +0000 (UTC) X-FDA: 77395346658.07.worm95_520448227247 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin07.hostedemail.com (Postfix) with ESMTP id 0FCB21803F9AC for ; Wed, 21 Oct 2020 09:04:29 +0000 (UTC) X-HE-Tag: worm95_520448227247 X-Filterd-Recvd-Size: 12239 Received: from mx4.veeam.com (mx4.veeam.com [104.41.138.86]) by imf17.hostedemail.com (Postfix) with ESMTP for ; Wed, 21 Oct 2020 09:04:28 +0000 (UTC) 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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