From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51821) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xj9Ch-0002zr-BK for qemu-devel@nongnu.org; Tue, 28 Oct 2014 12:01:09 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Xj9Cb-0003UY-M5 for qemu-devel@nongnu.org; Tue, 28 Oct 2014 12:01:03 -0400 Date: Tue, 28 Oct 2014 16:00:41 +0000 From: Stefan Hajnoczi Message-ID: <20141028160041.GA3969@stefanha-thinkpad.redhat.com> References: <1413984320-28585-1-git-send-email-baloo@gandi.net> <5448A656.6030204@msgid.tls.msk.ru> <87egtzusaa.fsf@blackfin.pond.sub.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="J/dobhs11T7y2rNN" Content-Disposition: inline In-Reply-To: <87egtzusaa.fsf@blackfin.pond.sub.org> Subject: Re: [Qemu-devel] [Qemu-trivial] [PATCH] vmdk: Fix cylinders number during convert List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: Kevin Wolf , Fam Zheng , qemu-trivial@nongnu.org, Michael Tokarev , qemu-devel@nongnu.org, Stefan Hajnoczi , Arthur Gautier --J/dobhs11T7y2rNN Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Oct 23, 2014 at 10:03:25AM +0200, Markus Armbruster wrote: > Michael Tokarev writes: >=20 > > On 10/22/2014 05:25 PM, Arthur Gautier wrote: > >> We can not rely on int cast to get a correct number of cylinders. The > >> cylinders information was wrong in 49.9999% of cases. > >>=20 > >> This ensures the cylinders always gets the ceiling value. > > > > Good thing, especially the good probability :), and also a good patch > > which comes with a test. > > > > But I wonder if anything can break this way? Migration, windows guest > > being unable to find its partitions, something else? > > > > And more. What-if our drive size in cylinders will be larger than > > the size in bytes? The proposed div_round_up() will increase number > > of cylinders, so size in CHS will be larger than size in bytes. Maybe > > there was a reason why originally the size in cylinders was calculated > > by truncating extra fractional part? What-if guest will try to access > > the very last CHS which is incomplete? >=20 > Too many questions for -trivial, copying VMDK maintainers. Fam: What do you think about this change? Stefan --J/dobhs11T7y2rNN Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEcBAEBAgAGBQJUT72pAAoJEJykq7OBq3PIzMwH/04lCoPx5vP1HokDsqoqi2AL xrsjjTNrzvzTMhuwp4DjOs8VymeqLZ6RPw/gcsXr1R5RijTi9/zi9xw2JduaY/Dj l5mmrhwCpcM/fi6Ae5w5dufMHKrL5A7vCwukQo9DP/VT4+RCeHomEsMXCoQlgake +N+iPC8LVvDwB2yoj/cxcKHOhmMuByMR+J1oVLrP5EX3h+haCiyKcceIEcyTUP20 SLHM3r/hY2k9AAvzgFgHV/pxTAVO2H7PKW7pnKV5cXJ9bm1NDveYp/F2r38ky4LI +rCQXh/Hx7/FkpWD/y6q9bhtAt/Ha6y18LBT7e6WfFJS0WKT56rQXdV4rQufsjg= =GMqT -----END PGP SIGNATURE----- --J/dobhs11T7y2rNN--