From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58389) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b5ZG9-0001Zf-Et for qemu-devel@nongnu.org; Wed, 25 May 2016 09:54:06 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b5ZG4-0002sZ-De for qemu-devel@nongnu.org; Wed, 25 May 2016 09:54:05 -0400 Date: Wed, 25 May 2016 15:53:51 +0200 From: Kevin Wolf Message-ID: <20160525135351.GI4815@noname.redhat.com> References: <1464128732-12667-1-git-send-email-eblake@redhat.com> <1464128732-12667-7-git-send-email-eblake@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1464128732-12667-7-git-send-email-eblake@redhat.com> Subject: Re: [Qemu-devel] [PATCH 06/13] qcow2: Convert to bdrv_co_pwrite_zeroes() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake Cc: qemu-devel@nongnu.org, qemu-block@nongnu.org, Max Reitz Am 25.05.2016 um 00:25 hat Eric Blake geschrieben: > Another step on our continuing quest to switch to byte-based > interfaces. > > There are still opportunities to optimize the qcow2 handling > of zero clusters. For example, if the backing file only has > non-zero data in the portion about to be overwritten, then > we could widen the request and make the entire cluster zero, > rather than falling back to -ENOTSUP. But for this patch, > intentionally leave the semantics unchanged, even if not > optimal. > > Signed-off-by: Eric Blake Reviewed-by: Kevin Wolf