From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36939) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1agsAY-0000pR-46 for qemu-devel@nongnu.org; Fri, 18 Mar 2016 07:02:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1agsAS-0000EF-Ih for qemu-devel@nongnu.org; Fri, 18 Mar 2016 07:02:14 -0400 Date: Fri, 18 Mar 2016 12:01:59 +0100 From: Kevin Wolf Message-ID: <20160318110159.GA5515@noname.redhat.com> References: <1458237102-16204-1-git-send-email-berrange@redhat.com> <1458237102-16204-2-git-send-email-berrange@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1458237102-16204-2-git-send-email-berrange@redhat.com> Subject: Re: [Qemu-devel] [PATCH v5 1/7] block: add flag to indicate that no I/O will be performed List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Daniel P. Berrange" Cc: Fam Zheng , qemu-devel@nongnu.org, qemu-block@nongnu.org Am 17.03.2016 um 18:51 hat Daniel P. Berrange geschrieben: > When opening an image it is useful to know whether the caller > intends to perform I/O on the image or not. In the case of > encrypted images this will allow the block driver to avoid > having to prompt for decryption keys when we merely want to > query header metadata about the image. eg qemu-img info > > This flag is enforced at the top level only, since even if > we don't want todo I/O on the 'qcow2' file payload, the > underlying 'file' driver will still need todo I/O to read > the qcow2 header, for example. > > Reviewed-by: Eric Blake > Signed-off-by: Daniel P. Berrange Looks good to me, but it needs a rebase because it conflicts with the latest changes to qemu-img. Kevin