From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32CE3C433ED for ; Thu, 22 Apr 2021 18:43:26 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 770C961405 for ; Thu, 22 Apr 2021 18:43:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 770C961405 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:44364 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lZeIO-0002qQ-2f for qemu-devel@archiver.kernel.org; Thu, 22 Apr 2021 14:43:24 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:41522) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lZeH7-0002KR-BG for qemu-devel@nongnu.org; Thu, 22 Apr 2021 14:42:05 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:26139) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lZeGx-000640-FA for qemu-devel@nongnu.org; Thu, 22 Apr 2021 14:42:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619116908; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=xfPGm14YG0zbVr3Lu2fQjqOmkV/VSTm6mBoDPEpfu/g=; b=S3cD6e7S+4N/AFvvLuSSQzQ9/xb2n76btw+oubwpdy5EsoDwlsCaqkfF9vEfpmHdWGc+mJ HJVTKnKfeydE2zLvXAq3ra36E6Ifs+B+bE+ZXyVnb/pPzzzAZn0v9B6kL/m3k0Nn8l6lcz KkH5CCFUD8ZhbTvbWKpH+dSOxOu4ySU= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-533-_879ODCDMOSkQEJqmD_DMQ-1; Thu, 22 Apr 2021 14:41:43 -0400 X-MC-Unique: _879ODCDMOSkQEJqmD_DMQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DCF04108C31D; Thu, 22 Apr 2021 18:41:20 +0000 (UTC) Received: from [10.3.113.39] (ovpn-113-39.phx2.redhat.com [10.3.113.39]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 848695C261; Thu, 22 Apr 2021 18:41:20 +0000 (UTC) Subject: Re: [PATCH v2 1/2] block: Add BDRV_O_NO_SHARE for blk_new_open() To: Kevin Wolf , qemu-block@nongnu.org References: <20210422164344.283389-1-kwolf@redhat.com> <20210422164344.283389-2-kwolf@redhat.com> From: Eric Blake Organization: Red Hat, Inc. Message-ID: <3944ca92-87f9-1ffc-8886-91da46632831@redhat.com> Date: Thu, 22 Apr 2021 13:41:19 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20210422164344.283389-2-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eblake@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable 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: qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 4/22/21 11:43 AM, Kevin Wolf wrote: > Normally, blk_new_open() just shares all permissions. This was fine > originally when permissions only protected against uses in the same > process because no other part of the code would actually get to access > the block nodes opened with blk_new_open(). However, since we use it for > file locking now, unsharing permissions becomes desirable. > > Add a new BDRV_O_NO_SHARE flag that is used in blk_new_open() to unshare > any permissions that can be unshared. > > Signed-off-by: Kevin Wolf > --- > include/block/block.h | 1 + > block/block-backend.c | 19 +++++++++++++------ > 2 files changed, 14 insertions(+), 6 deletions(-) > > diff --git a/include/block/block.h b/include/block/block.h > index b3f6e509d4..735db05a39 100644 > --- a/include/block/block.h > +++ b/include/block/block.h > @@ -101,6 +101,7 @@ typedef struct HDGeometry { > uint32_t cylinders; > } HDGeometry; > > +#define BDRV_O_NO_SHARE 0x0001 /* don't share permissons */ permissions With the typo fix, Reviewed-by: Eric Blake -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org