From nobody Tue Feb 10 05:39:49 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=1589295442; cv=none; d=zohomail.com; s=zohoarc; b=ffUIOGvUxrszem4N/b6d72iPgiL395NDAEpBgbbFynP3YJMAoHTIweoB80HRFzp7iEgkKhnYYSUpvG0YI3kxvAI21Mw6KNqxQD38OWol1Q7HXp45Wd0Lod6Hrm4uBZSEboIlU3ClJkkD9unonAIWPpCVVAtWPg6n00Myg7+S8DY= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1589295442; 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=YLVJmGoFk02HSBU8fQlrWqxr1N2DDIrXh6p+XuT2yWw=; b=bOuPkG7TsTmus+jw1JQklvfqFcpVOXdSgZDHK6xGwJ2V3K7R2Ap2vjwfeMoWQ60ifz2uSbz6d282AVQ5kHyOkCaj2GmLYtu8REfPgrEdZOZaicsGEvgY0A5UdAUlNSKFkU+KlKt4RsOD1rbusmlW+c3B4FucWRx1Tk3E9MZ4XLg= 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 1589295442027592.5968526368957; Tue, 12 May 2020 07:57:22 -0700 (PDT) Received: from localhost ([::1]:36302 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jYWLQ-0003vn-L6 for importer@patchew.org; Tue, 12 May 2020 10:57:20 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60218) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jYWHj-0004py-PD; Tue, 12 May 2020 10:53:31 -0400 Received: from relay.sw.ru ([185.231.240.75]:45838) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jYWHh-0005os-4Z; Tue, 12 May 2020 10:53:30 -0400 Received: from dhcp-172-16-25-136.sw.ru ([172.16.25.136] helo=localhost.sw.ru) by relay.sw.ru with esmtp (Exim 4.92.3) (envelope-from ) id 1jYWHa-0003c8-Kp; Tue, 12 May 2020 17:53:22 +0300 From: Andrey Shinkevich To: qemu-block@nongnu.org Subject: [PATCH v3 12/15] copy-on-read: add filter append/drop functions Date: Tue, 12 May 2020 17:53:13 +0300 Message-Id: <1589295196-773454-13-git-send-email-andrey.shinkevich@virtuozzo.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1589295196-773454-1-git-send-email-andrey.shinkevich@virtuozzo.com> References: <1589295196-773454-1-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=relay.sw.ru X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/12 10:53:25 X-ACL-Warn: Detected OS = Linux 3.1-3.10 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_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN 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, fam@euphon.net, vsementsov@virtuozzo.com, armbru@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com, 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 --- block/copy-on-read.c | 98 ++++++++++++++++++++++++++++++++++++++++++++++++= ++++ 1 file changed, 98 insertions(+) diff --git a/block/copy-on-read.c b/block/copy-on-read.c index 4030d56..31e1619 100644 --- a/block/copy-on-read.c +++ b/block/copy-on-read.c @@ -24,8 +24,15 @@ #include "qemu/cutils.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" =20 =20 +typedef struct BDRVStateCOR { + bool active; +} BDRVStateCOR; + static int cor_open(BlockDriverState *bs, QDict *options, int flags, Error **errp) { @@ -57,6 +64,17 @@ 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 @@ -150,6 +168,7 @@ static int cor_change_backing_file(BlockDriverState *bs, =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, @@ -178,4 +197,83 @@ 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_filtered_rw_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); --=20 1.8.3.1