From nobody Tue May 7 20:00:36 2024 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; 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=reject dis=none) header.from=genymobile.com ARC-Seal: i=1; a=rsa-sha256; t=1630423690; cv=none; d=zohomail.com; s=zohoarc; b=XYQe3IK+WgrrrYg30yzdGkgRiBBFsDguAjltGxqmSm8ECqSkDYRKqL4PJYliMmKWsmxkDLmWqTNGgDqi5ge6Mm4nlxLZ7XP0iDsnG2pMf4GuNbflwaEL2aGSHW1R+y9SEsgQmzhYYvb7jcUVBaf1xEcrP3Il3woAoCHa3tzcOpU= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1630423690; h=Content-Transfer-Encoding:Cc:Date:From:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Sender:Subject; bh=5x2arDbB8sLXtiooJkHC4NR0dmL5V2If/7TksgITY7U=; b=f5FrpG0aWIOtoQA6Q/saxVILVAeS/+fPeRHkDt2t8yLHztrbG18dFKoJNhuNUOp6eetQxxKm5exyK3P9n57jl5rDSlQRASnytjvJCVL3Rb6oqGMQHE4T4JdIHA7QL6VBnjkEQnxJFHEo5r7+bmMsOtnrPytfF2jCEZgfA6jEfrI= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; 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=reject dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1630423690628704.7513566936223; Tue, 31 Aug 2021 08:28:10 -0700 (PDT) Received: from localhost ([::1]:48586 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mL5gG-00022u-VW for importer@patchew.org; Tue, 31 Aug 2021 11:28:08 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:36392) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mL4a7-0007uS-Iq for qemu-devel@nongnu.org; Tue, 31 Aug 2021 10:17:43 -0400 Received: from mail-wr1-x433.google.com ([2a00:1450:4864:20::433]:43653) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1mL4a4-0006hz-It for qemu-devel@nongnu.org; Tue, 31 Aug 2021 10:17:42 -0400 Received: by mail-wr1-x433.google.com with SMTP id b6so27951433wrh.10 for ; Tue, 31 Aug 2021 07:17:39 -0700 (PDT) Received: from localhost.localdomain (136.165.66.86.rev.sfr.net. [86.66.165.136]) by smtp.gmail.com with ESMTPSA id e26sm19375258wrc.6.2021.08.31.07.17.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 31 Aug 2021 07:17:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=genymobile.com; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=5x2arDbB8sLXtiooJkHC4NR0dmL5V2If/7TksgITY7U=; b=FFnXA0F2kc9TFeKxZJIJxf5e6t5xS8DcTpSvAYjddMOkQhJnHhUm34PCmO3rjvbb9T B/Cvnp26kFsR9JkxiSBfPVJ8LBSCNWG8OzwVjgiC1/pAUvXn8oIytjR7Pp2uaEvW84/o cx+Ti9NlMJHUDEcWiNU9mY4tdVlMop+zkNvvDLlCNdYpaVucjxsek2uUxYchcnNuBmCL 3yXiZvQR4M74BIf0kZdsq87mmv48iw9UD6a5yXxESQlG+8xCAQNhPWfEkYzTXK7eBLbJ oQfmN1qt6sk8dJq1GPXUByYyi3qmcfcIRdQq/ZXpGZgVSCOWmQVypuveMqyUxBKGdm5R UZOg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=5x2arDbB8sLXtiooJkHC4NR0dmL5V2If/7TksgITY7U=; b=FoTEUpaNUaDHvatQZ+wXTKeHUxVIa5siZn3HfJxF+KzkSy3QJCAKCPAnXW2KNKUNRJ UViil0XGAQr0cXGg+Is9y2/qotUuMKp9ScoN7GRzFppuml5XjX10RwerT+AWb/+Y0ONd byWEW/Trr9KEte1ZrwuNGm9mVMbBzpm6+sLZGYukbP3ABHsZSL88+s1Rb5CQNe5Uiu2F HZQBooe98MQ1STo8CMP97emna4EH6KYgj/86dbbe/uUD61rGCJHlW/UCOpC3ok02A7qo tx57NI8iB6xElrZdyUw96GspHh8sBoaxjc0hSxd0ASXL5+md0/F93MOOzueNhEKUN/Dp oKEw== X-Gm-Message-State: AOAM530ZjRoDGAP5osEhFV0ufGo0TZ3zZ74JxwiHGo57Qg9hMhs6+Fd5 yrabvMi7ICmUpNzkqG2lNC8auQ== X-Google-Smtp-Source: ABdhPJziA0aSSwwLycbIO5WKuKR1oUUfyfkOxQL43+JWzC0cOkzpd+JkKQ5dDUpAlYvg+bRmY6/aTQ== X-Received: by 2002:a5d:58e9:: with SMTP id f9mr32294747wrd.154.1630419457920; Tue, 31 Aug 2021 07:17:37 -0700 (PDT) From: Guillaume Roche To: Cc: Guillaume Roche , Kevin Wolf , Hanna Reitz , qemu-block@nongnu.org (open list:Block layer core), qemu-devel@nongnu.org (open list:All patches CC here) Subject: [PATCH] block/vvfat: Fix ro shared folder Date: Tue, 31 Aug 2021 16:17:27 +0200 Message-Id: <20210831141727.347597-1-groche@genymobile.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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=2a00:1450:4864:20::433; envelope-from=groche@genymobile.com; helo=mail-wr1-x433.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-Mailman-Approved-At: Tue, 31 Aug 2021 11:27:08 -0400 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" X-ZohoMail-DKIM: pass (identity @genymobile.com) X-ZM-MESSAGEID: 1630423691464100001 Content-Type: text/plain; charset="utf-8" QEMU exits in error when passing a vfat shared folder in read-only mode. To fix this issue, this patch removes any potential write permission from cumulative_perms, when a read-only block device is in use. Buglink: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=3D918950 Signed-off-by: Guillaume Roche --- This is an attempt to fix this behavior, but it feels a bit hacky to me since this patch checks for the vvfat format in a generic function. However, I'd be glad to have some advice to make it better. Anyway, I ran the block tests to ensure this does not introduce any regression. To add some context: I know that this can be worked around by setting=20 the shared folder in rw mode. But our use-case requires using both shared and VM snapshots, and QEMU prevents using snapshot with a rw=20 shared folder. block.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/block.c b/block.c index e97ce0b1c8..3f59e3843f 100644 --- a/block.c +++ b/block.c @@ -2383,6 +2383,12 @@ void bdrv_get_cumulative_perm(BlockDriverState *bs, = uint64_t *perm, cumulative_shared_perms &=3D c->shared_perm; } =20 + /* Discard write permission if vvfat block device is read-only */ + const char *format =3D bdrv_get_format_name(bs); + if (format !=3D NULL && strncmp(format, "vvfat", 5) =3D=3D 0 && bdrv_i= s_read_only(bs)) { + cumulative_perms &=3D ~BLK_PERM_WRITE; + } + *perm =3D cumulative_perms; *shared_perm =3D cumulative_shared_perms; } --=20 2.31.1