From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44713) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XANqr-00020O-LN for qemu-devel@nongnu.org; Thu, 24 Jul 2014 14:34:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XANql-0001Fd-QG for qemu-devel@nongnu.org; Thu, 24 Jul 2014 14:34:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57460) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XANql-0001FP-Eh for qemu-devel@nongnu.org; Thu, 24 Jul 2014 14:34:43 -0400 Date: Thu, 24 Jul 2014 14:34:39 -0400 From: Jeff Cody Message-ID: <20140724183439.GA24801@localhost.localdomain> References: <1406035177-221890-1-git-send-email-den@openvz.org> <1406035177-221890-2-git-send-email-den@openvz.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1406035177-221890-2-git-send-email-den@openvz.org> Subject: Re: [Qemu-devel] [PATCH 1/4] block/parallels: extend parallels format header with actual data values List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Denis V. Lunev" Cc: Kevin Wolf , qemu-devel@nongnu.org, Stefan Hajnoczi On Tue, Jul 22, 2014 at 05:19:34PM +0400, Denis V. Lunev wrote: > Parallels image format has several additional fields inside: > - nb_sectors is actually 64 bit wide. Upper 32bits are not used for > images with signature "WithoutFreeSpace" and must be explicitely s/explicitely/explicitly > zeroed according to Parallels. They will be used for images with > signature "WithouFreSpacExt" > - inuse is magic which means that the image is currently opened for > read/write or was not closed correctly, the magic is 0x746f6e59 > - data_off is the location of the first data block. It can be zero > and in this case I think you may have forgotten to finish this sentence :) > > This patch adds these values to struct parallels_header and adds > proper handling of nb_sectors for currently supported WithoutFreeSpace > images. > > WithouFreSpacExt will be covered in the next patch. > > Signed-off-by: Denis V. Lunev > CC: Kevin Wolf > CC: Stefan Hajnoczi > --- > block/parallels.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/block/parallels.c b/block/parallels.c > index 1a5bd35..c44df87 100644 > --- a/block/parallels.c > +++ b/block/parallels.c > @@ -41,8 +41,10 @@ struct parallels_header { > uint32_t cylinders; > uint32_t tracks; > uint32_t catalog_entries; > - uint32_t nb_sectors; > - char padding[24]; > + uint64_t nb_sectors; > + uint32_t inuse; > + uint32_t data_off; > + char padding[12]; > } QEMU_PACKED; > > typedef struct BDRVParallelsState { > @@ -90,7 +92,7 @@ static int parallels_open(BlockDriverState *bs, QDict *options, int flags, > goto fail; > } > > - bs->total_sectors = le32_to_cpu(ph.nb_sectors); > + bs->total_sectors = (uint32_t)le64_to_cpu(ph.nb_sectors); I think an explicit bit mask on the upper 32 bits would fit better here than a cast, especially since neither 'bs->total_sectors' nor 'ph.nb_sectors' is a uint32_t. E.g.: bs->total_sectors = 0xffffffff & le64_to_cpu(ph.nb_sectors); > > s->tracks = le32_to_cpu(ph.tracks); > if (s->tracks == 0) { > -- > 1.9.1 > >