From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0BBC72D9EF0; Wed, 11 Feb 2026 15:43:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.95.11.211 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770824589; cv=none; b=p66/0K46Sea7pAONyCZxjJY1owNGahWQxGzwUrW0BV+pT459hcYLSKPvHlsIMwoEFOVryLTji8Zn4kqYmWvpRDac90y5THcv7AVtdaunS6WX0WckKWO5DiZizLF1lol25UEMno1WLxwtaa7sXHoKMQ7vpSvkXiwmcsdjv3ufd7I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770824589; c=relaxed/simple; bh=Our+RXGlwLz6j296ZYkaEHksT17m9rMxAqPteuXv8ko=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=XIE584DeHfCMjTbuoewh4h9TxrMfugUokeKL2annmVGJ3mLo+3+EPeWxAZT/XbIVPR+eMXY2FTb+Aq62H82DvZ2xjos07Op1xB2H36eRJXVHhRSDrhDYTce878hzB/qsLxKt8+Yz1QJT6KQABTVgE9UO7JNankS6lk+/aw8uqQI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lst.de; spf=pass smtp.mailfrom=lst.de; arc=none smtp.client-ip=213.95.11.211 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lst.de Received: by verein.lst.de (Postfix, from userid 2407) id 7470968C7B; Wed, 11 Feb 2026 16:42:57 +0100 (CET) Date: Wed, 11 Feb 2026 16:42:57 +0100 From: Christoph Hellwig To: Stefan Hajnoczi Cc: Jens Axboe , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, Christoph Hellwig , Martin Wilck , Benjamin Marzinski , Hannes Reinecke Subject: Re: [PATCH] block: allow IOC_PR_READ_* ioctls with BLK_OPEN_READ Message-ID: <20260211154257.GA10237@lst.de> References: <20260210163617.144359-1-stefanha@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260210163617.144359-1-stefanha@redhat.com> User-Agent: Mutt/1.5.17 (2007-11-01) On Tue, Feb 10, 2026 at 11:36:17AM -0500, Stefan Hajnoczi wrote: > It is safe to reduce the permission requirement from BLK_OPEN_WRITE to > BLK_OPEN_READ since these two ioctls do not modify the persistent > reservation state. Userspace cannot use the information fetched by these > ioctls to make changes to the device unless it later opens the device > with BLK_OPEN_WRITE. Hmm. How often do we give unprivileged users access to the block device node anyway? But I guess if they can read all the data on the device, they might as well see the reservation holders as well: Reviewed-by: Christoph Hellwig