From nobody Tue Feb 10 05:41:22 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=pass(p=none dis=none) header.from=nongnu.org ARC-Seal: i=1; a=rsa-sha256; t=1601298816; cv=none; d=zohomail.com; s=zohoarc; b=go+yy5PQavWPn5wcYMrbSMDGwcTBwUVbCFIB/SXn+8+urgLMbtyHe3xczY8S2SqXN/kR+CR5jcp/jwxq8vNM6HUlPGSudVZxwRDbw9pgD3n2RXvjFmHgVDL1a1W0CS4z62YbA9/vPxg9JGUD5ec/ti226lXpd/Ifj/pyuYQ7UMM= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1601298816; h=Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:Message-ID:Reply-To:References:Sender:Subject:To; bh=dVTmzxcjYvngmjCN9EN2Y8wTiXbZu/B0jVJkQJKm1P0=; b=cPg1FlRbJJeHtwFGpoMrKVsON424Iju15QV18nGG2WZ2gjjNeLWKq/5UJ/h9BSqYRGGzgQGw8M1mwR2PW6Fei1w82fRcS5/G4FpJyf6P0v9EI/v8S/YJep3Mqs3X5JW9OEFIjblUNhVgpf9SljGsyI6kWgCfhzqJp2XtABoTzOs= 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=pass 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 1601298816512304.4594059659429; Mon, 28 Sep 2020 06:13:36 -0700 (PDT) Received: from localhost ([::1]:57382 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kMsyF-00082h-9T for importer@patchew.org; Mon, 28 Sep 2020 09:13:35 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:55518) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kMsmQ-0004v4-Af; Mon, 28 Sep 2020 09:01:23 -0400 Received: from relay.sw.ru ([185.231.240.75]:58536 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 1kMsmK-0000Ma-Db; Mon, 28 Sep 2020 09:01:21 -0400 Received: from [172.16.25.136] (helo=localhost.sw.ru) by relay3.sw.ru with esmtp (Exim 4.94) (envelope-from ) id 1kMslm-001tba-F1; Mon, 28 Sep 2020 16:00:42 +0300 To: qemu-block@nongnu.org Cc: qemu-devel@nongnu.org, kwolf@redhat.com, mreitz@redhat.com, stefanha@redhat.com, fam@euphon.net, jsnow@redhat.com, armbru@redhat.com, eblake@redhat.com, den@openvz.org, vsementsov@virtuozzo.com, andrey.shinkevich@virtuozzo.com Subject: [PATCH v9 2/9] copy-on-read: add filter append/drop functions Date: Mon, 28 Sep 2020 15:59:54 +0300 Message-Id: <1601298001-774096-3-git-send-email-andrey.shinkevich@virtuozzo.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1601298001-774096-1-git-send-email-andrey.shinkevich@virtuozzo.com> References: <1601298001-774096-1-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 = 2020/09/28 09:00:28 X-ACL-Warn: Detected OS = Linux 3.11 and newer [fuzzy] 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: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Reply-to: Andrey Shinkevich From: Andrey Shinkevich via 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 | 84 ++++++++++++++++++++++++++++++++++++++++++++++++= ++++ 1 file changed, 84 insertions(+) diff --git a/block/copy-on-read.c b/block/copy-on-read.c index cb03e0f..3c8231f 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 +52,13 @@ 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; + + /* + * We don't need to call bdrv_child_refresh_perms() now as the permiss= ions + * will be updated later when the filter node gets its parent. + */ + return 0; } =20 @@ -57,6 +74,17 @@ 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 +163,7 @@ 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 +188,59 @@ static void bdrv_copy_on_read_init(void) bdrv_register(&bdrv_copy_on_read); } =20 + +BlockDriverState *bdrv_cor_filter_append(BlockDriverState *bs, + QDict *node_options, + int flags, Error **errp) +{ + BlockDriverState *cor_filter_bs; + Error *local_err =3D NULL; + + cor_filter_bs =3D bdrv_open(NULL, NULL, node_options, flags, errp); + if (cor_filter_bs =3D=3D NULL) { + error_prepend(errp, "Could not create COR-filter node: "); + return NULL; + } + + 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; + } + + 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); --=20 1.8.3.1