From nobody Tue Feb 10 01:32:46 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=virtuozzo.com ARC-Seal: i=1; a=rsa-sha256; t=1597785956; cv=none; d=zohomail.com; s=zohoarc; b=laItVjjQDuI2X0x9qcoqlThCIIvq3MMQsyZ9d88m/AYMAltnoVs9UyABxO2mlLKZgcHAQ+wyLuoRFZdpadd+2RcM23PMprUhwhR6D542YqscYhvJpiJqcpAaqaRTmmQwZkyQy45hDGMa4UYmpVPlFJihy4rRFv2nKP2BgPm6eUE= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1597785956; h=Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:Message-ID:References:Sender:Subject:To; bh=oxwbtNWKeOmS11XeT9zpOpQZ6+0vJ6kw1ggMyYQrNms=; b=fgsAqCkH3GO/eIuESg7LYqSgmZmBAksOa7Wjzo/7kPWLANFVjeFauGruCvTGBxpyrim4UdaOM37/QSNGvUCwGPVyRCgNxx2W8Vs+VMAya4tdKFrz1y0L5zxxjITuN3+ijsQkOrGz+xkShmuEWAzAmC5t4Wq9MgsBCano7AKvREU= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1597785956715320.21457668227947; Tue, 18 Aug 2020 14:25:56 -0700 (PDT) Received: from localhost ([::1]:52110 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k897D-0007KH-0B for importer@patchew.org; Tue, 18 Aug 2020 17:25:55 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:41906) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k8968-0005qL-5v; Tue, 18 Aug 2020 17:24:48 -0400 Received: from relay.sw.ru ([185.231.240.75]:41578 helo=relay3.sw.ru) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k8965-0003cX-2d; Tue, 18 Aug 2020 17:24:47 -0400 Received: from [172.16.25.136] (helo=localhost.sw.ru) by relay3.sw.ru with esmtp (Exim 4.94) (envelope-from ) id 1k895p-000GtS-MG; Wed, 19 Aug 2020 00:24:29 +0300 From: Andrey Shinkevich To: qemu-block@nongnu.org Subject: [PATCH v6 2/4] copy-on-read: add filter append/drop functions Date: Wed, 19 Aug 2020 00:24:38 +0300 Message-Id: <1597785880-431103-3-git-send-email-andrey.shinkevich@virtuozzo.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1597785880-431103-1-git-send-email-andrey.shinkevich@virtuozzo.com> References: <1597785880-431103-1-git-send-email-andrey.shinkevich@virtuozzo.com> Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=185.231.240.75; envelope-from=andrey.shinkevich@virtuozzo.com; helo=relay3.sw.ru X-detected-operating-system: by eggs.gnu.org: First seen = 2020/08/18 17:24:42 X-ACL-Warn: Detected OS = Linux 3.11 and newer 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 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, vsementsov@virtuozzo.com, armbru@redhat.com, qemu-devel@nongnu.org, andrey.shinkevich@virtuozzo.com, den@openvz.org, mreitz@redhat.com, jsnow@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Provide API for the COR-filter insertion/removal. Also, drop the filter child permissions for an inactive state when the filter node is being removed. Signed-off-by: Andrey Shinkevich Reviewed-by: Vladimir Sementsov-Ogievskiy --- block/copy-on-read.c | 103 +++++++++++++++++++++++++++++++++++++++++++++++= ++++ block/copy-on-read.h | 36 ++++++++++++++++++ 2 files changed, 139 insertions(+) create mode 100644 block/copy-on-read.h diff --git a/block/copy-on-read.c b/block/copy-on-read.c index cb03e0f..150d9b7 100644 --- a/block/copy-on-read.c +++ b/block/copy-on-read.c @@ -23,11 +23,21 @@ #include "qemu/osdep.h" #include "block/block_int.h" #include "qemu/module.h" +#include "qapi/error.h" +#include "qapi/qmp/qdict.h" +#include "block/copy-on-read.h" + + +typedef struct BDRVStateCOR { + bool active; +} BDRVStateCOR; =20 =20 static int cor_open(BlockDriverState *bs, QDict *options, int flags, Error **errp) { + BDRVStateCOR *state =3D bs->opaque; + bs->file =3D bdrv_open_child(NULL, options, "file", bs, &child_of_bds, BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY, false, errp); @@ -42,6 +52,8 @@ static int cor_open(BlockDriverState *bs, QDict *options,= int flags, ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK) & bs->file->bs->supported_zero_flags); =20 + state->active =3D true; + return 0; } =20 @@ -57,6 +69,17 @@ static void cor_child_perm(BlockDriverState *bs, BdrvChi= ld *c, uint64_t perm, uint64_t shared, uint64_t *nperm, uint64_t *nshared) { + BDRVStateCOR *s =3D bs->opaque; + + if (!s->active) { + /* + * While the filter is being removed + */ + *nperm =3D 0; + *nshared =3D BLK_PERM_ALL; + return; + } + *nperm =3D perm & PERM_PASSTHROUGH; *nshared =3D (shared & PERM_PASSTHROUGH) | PERM_UNCHANGED; =20 @@ -135,6 +158,7 @@ static void cor_lock_medium(BlockDriverState *bs, bool = locked) =20 static BlockDriver bdrv_copy_on_read =3D { .format_name =3D "copy-on-read", + .instance_size =3D sizeof(BDRVStateCOR), =20 .bdrv_open =3D cor_open, .bdrv_child_perm =3D cor_child_perm, @@ -159,4 +183,83 @@ static void bdrv_copy_on_read_init(void) bdrv_register(&bdrv_copy_on_read); } =20 + +static BlockDriverState *create_filter_node(BlockDriverState *bs, + const char *filter_node_name, + Error **errp) +{ + QDict *opts =3D qdict_new(); + + qdict_put_str(opts, "driver", "copy-on-read"); + qdict_put_str(opts, "file", bdrv_get_node_name(bs)); + if (filter_node_name) { + qdict_put_str(opts, "node-name", filter_node_name); + } + + return bdrv_open(NULL, NULL, opts, BDRV_O_RDWR, errp); +} + + +BlockDriverState *bdrv_cor_filter_append(BlockDriverState *bs, + const char *filter_node_name, + Error **errp) +{ + BlockDriverState *cor_filter_bs; + BDRVStateCOR *state; + Error *local_err =3D NULL; + + cor_filter_bs =3D create_filter_node(bs, filter_node_name, errp); + if (cor_filter_bs =3D=3D NULL) { + error_prepend(errp, "Could not create filter node: "); + return NULL; + } + + if (!filter_node_name) { + cor_filter_bs->implicit =3D true; + } + + bdrv_drained_begin(bs); + bdrv_replace_node(bs, cor_filter_bs, &local_err); + bdrv_drained_end(bs); + + if (local_err) { + bdrv_unref(cor_filter_bs); + error_propagate(errp, local_err); + return NULL; + } + + state =3D cor_filter_bs->opaque; + state->active =3D true; + + return cor_filter_bs; +} + + +void bdrv_cor_filter_drop(BlockDriverState *cor_filter_bs) +{ + BdrvChild *child; + BlockDriverState *bs; + BDRVStateCOR *s =3D cor_filter_bs->opaque; + + child =3D bdrv_filter_child(cor_filter_bs); + if (!child) { + return; + } + bs =3D child->bs; + + /* Retain the BDS until we complete the graph change. */ + bdrv_ref(bs); + /* Hold a guest back from writing while permissions are being reset. */ + bdrv_drained_begin(bs); + /* Drop permissions before the graph change. */ + s->active =3D false; + bdrv_child_refresh_perms(cor_filter_bs, child, &error_abort); + bdrv_replace_node(cor_filter_bs, bs, &error_abort); + + bdrv_drained_end(bs); + bdrv_unref(bs); + bdrv_unref(cor_filter_bs); +} + + block_init(bdrv_copy_on_read_init); diff --git a/block/copy-on-read.h b/block/copy-on-read.h new file mode 100644 index 0000000..db03c6c --- /dev/null +++ b/block/copy-on-read.h @@ -0,0 +1,36 @@ +/* + * Copy-on-read filter block driver + * + * The filter driver performs Copy-On-Read (COR) operations + * + * Copyright (c) 2018-2020 Virtuozzo International GmbH. + * + * Author: + * Andrey Shinkevich + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + +#ifndef COPY_ON_READ_FILTER +#define COPY_ON_READ_FILTER + +#include "block/block_int.h" +#include "block/block-copy.h" + +BlockDriverState *bdrv_cor_filter_append(BlockDriverState *bs, + const char *filter_node_name, + Error **errp); +void bdrv_cor_filter_drop(BlockDriverState *cor_filter_bs); + +#endif /* COPY_ON_READ_FILTER */ --=20 1.8.3.1