From nobody Sat May 4 00:45:21 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=virtuozzo.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1529596229652796.0545571148826; Thu, 21 Jun 2018 08:50:29 -0700 (PDT) Received: from localhost ([::1]:56177 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fW1qu-0007Fj-US for importer@patchew.org; Thu, 21 Jun 2018 11:50:28 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57239) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fW1pR-0006b1-Ox for qemu-devel@nongnu.org; Thu, 21 Jun 2018 11:48:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fW1pO-0003Ai-L9 for qemu-devel@nongnu.org; Thu, 21 Jun 2018 11:48:57 -0400 Received: from relay.sw.ru ([185.231.240.75]:41226) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fW1pO-0003A3-Ci; Thu, 21 Jun 2018 11:48:54 -0400 Received: from msk-vpn.virtuozzo.com ([195.214.232.6] helo=kvm.sw.ru) by relay.sw.ru with esmtp (Exim 4.90_1) (envelope-from ) id 1fW1pK-0005dQ-Ne; Thu, 21 Jun 2018 18:48:50 +0300 From: Vladimir Sementsov-Ogievskiy To: qemu-devel@nongnu.org, qemu-block@nongnu.org Date: Thu, 21 Jun 2018 18:48:50 +0300 Message-Id: <20180621154850.23354-1-vsementsov@virtuozzo.com> X-Mailer: git-send-email 2.11.1 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 185.231.240.75 Subject: [Qemu-devel] [PATCH] block/fleecing-filter: new filter driver for fleecing X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, den@openvz.com, vsementsov@virtuozzo.com, armbru@redhat.com, mreitz@redhat.com, jsnow@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" We need to synchronize backup job with reading from fleecing image like it was done in block/replication.c. Otherwise, the following situation is theoretically possible: 1. client start reading 2. client understand, that there is no corresponding cluster in fleecing image 3. client is going to read from backing file (i.e. active image) 4. guest writes to active image 5. this write is stopped by backup(sync=3Dnone) and cluster is copied to fleecing image 6. guest write continues... 7. and client reads _new_ (or partly new) date from active image So, this fleecing-filter should be above fleecing image, the whole picture of fleecing looks like this: +-------+ +------------+ | | | | | guest | | NBD client +<------+ | | | | | ++-----++ +------------+ |only read | ^ | | IO | | v | +-----+------+ ++-----+---------+ | | | | | internal | | active image +----+ | NBD server | | | | | | +-+--------------+ |backup +-+----------+ ^ |sync=3Dnone ^ |backing | |only read | | | +-+--------------+ | +------+----------+ | | | | | | fleecing image +<---+ | fleecing filter | | | | | +--------+-------+ +-----+-----------+ ^ | | | +--------------------------+ file Signed-off-by: Vladimir Sementsov-Ogievskiy --- qapi/block-core.json | 9 ++++--- block/fleecing-filter.c | 72 +++++++++++++++++++++++++++++++++++++++++++++= ++++ block/Makefile.objs | 1 + 3 files changed, 79 insertions(+), 3 deletions(-) create mode 100644 block/fleecing-filter.c diff --git a/qapi/block-core.json b/qapi/block-core.json index dfaa050651..b21bc3b693 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -2543,7 +2543,8 @@ 'host_device', 'http', 'https', 'iscsi', 'luks', 'nbd', 'nfs', 'null-aio', 'null-co', 'nvme', 'parallels', 'qcow', 'qcow2', '= qed', 'quorum', 'raw', 'rbd', 'replication', 'sheepdog', 'ssh', - 'throttle', 'vdi', 'vhdx', 'vmdk', 'vpc', 'vvfat', 'vxhs' ] } + 'throttle', 'vdi', 'vhdx', 'vmdk', 'vpc', 'vvfat', 'vxhs', + 'fleecing-filter' ] } =20 ## # @BlockdevOptionsFile: @@ -3607,7 +3608,8 @@ 'vmdk': 'BlockdevOptionsGenericCOWFormat', 'vpc': 'BlockdevOptionsGenericFormat', 'vvfat': 'BlockdevOptionsVVFAT', - 'vxhs': 'BlockdevOptionsVxHS' + 'vxhs': 'BlockdevOptionsVxHS', + 'fleecing-filter': 'BlockdevOptionsGenericFormat' } } =20 ## @@ -4135,7 +4137,8 @@ 'vmdk': 'BlockdevCreateNotSupported', 'vpc': 'BlockdevCreateOptionsVpc', 'vvfat': 'BlockdevCreateNotSupported', - 'vxhs': 'BlockdevCreateNotSupported' + 'vxhs': 'BlockdevCreateNotSupported', + 'fleecing-filter': 'BlockdevCreateNotSupported' } } =20 ## diff --git a/block/fleecing-filter.c b/block/fleecing-filter.c new file mode 100644 index 0000000000..60bac9c0b4 --- /dev/null +++ b/block/fleecing-filter.c @@ -0,0 +1,72 @@ +#include "qemu/osdep.h" +#include "qemu-common.h" +#include "block/blockjob.h" +#include "block/block_int.h" +#include "block/block_backup.h" + +static int64_t fleecing_getlength(BlockDriverState *bs) +{ + return bdrv_getlength(bs->file->bs); +} + +static coroutine_fn int fleecing_co_preadv(BlockDriverState *bs, + uint64_t offset, uint64_t bytes, + QEMUIOVector *qiov, int flags) +{ + int ret; + BlockJob *job =3D bs->file->bs->backing->bs->job; + CowRequest req; + + backup_wait_for_overlapping_requests(job, offset, bytes); + backup_cow_request_begin(&req, job, offset, bytes); + + ret =3D bdrv_co_preadv(bs->file, offset, bytes, qiov, flags); + + backup_cow_request_end(&req); + + return ret; +} + +static coroutine_fn int fleecing_co_pwritev(BlockDriverState *bs, + uint64_t offset, uint64_t byte= s, + QEMUIOVector *qiov, int flags) +{ + return -EINVAL; +} + +static bool fleecing_recurse_is_first_non_filter(BlockDriverState *bs, + BlockDriverState *candida= te) +{ + return bdrv_recurse_is_first_non_filter(bs->file->bs, candidate); +} + +static int fleecing_open(BlockDriverState *bs, QDict *options, + int flags, Error **errp) +{ + bs->file =3D bdrv_open_child(NULL, options, "file", bs, &child_file, f= alse, + errp); + + return bs->file ? 0 : -EINVAL; +} + +BlockDriver bdrv_fleecing_filter =3D { + .format_name =3D "fleecing-filter", + .protocol_name =3D "fleecing-filter", + .instance_size =3D 0, + + .bdrv_open =3D fleecing_open, + + .bdrv_getlength =3D fleecing_getlength, + .bdrv_co_preadv =3D fleecing_co_preadv, + .bdrv_co_pwritev =3D fleecing_co_pwritev, + + .is_filter =3D true, + .bdrv_recurse_is_first_non_filter =3D fleecing_recurse_is_first_non_fi= lter, +}; + +static void bdrv_fleecing_init(void) +{ + bdrv_register(&bdrv_fleecing_filter); +} + +block_init(bdrv_fleecing_init); diff --git a/block/Makefile.objs b/block/Makefile.objs index 899bfb5e2c..aa0a6dd971 100644 --- a/block/Makefile.objs +++ b/block/Makefile.objs @@ -27,6 +27,7 @@ block-obj-y +=3D write-threshold.o block-obj-y +=3D backup.o block-obj-$(CONFIG_REPLICATION) +=3D replication.o block-obj-y +=3D throttle.o copy-on-read.o +block-obj-y +=3D fleecing-filter.o =20 block-obj-y +=3D crypto.o =20 --=20 2.11.1