From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:43593) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tiq8J-0005e6-BZ for qemu-devel@nongnu.org; Wed, 12 Dec 2012 12:30:18 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Tiq84-0006Wq-Kg for qemu-devel@nongnu.org; Wed, 12 Dec 2012 12:30:06 -0500 Received: from mail.univention.de ([82.198.197.8]:2121) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tiq84-0006Wd-9V for qemu-devel@nongnu.org; Wed, 12 Dec 2012 12:29:56 -0500 From: Philipp Hahn Date: Wed, 12 Dec 2012 18:29:48 +0100 References: <1339767219-24297-1-git-send-email-kwolf@redhat.com> <201212121510.06575.hahn@univention.de> <50C8B6E2.9080306@redhat.com> In-Reply-To: <50C8B6E2.9080306@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart2447119.LnC1BrpWTJ"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Message-Id: <201212121829.53231.hahn@univention.de> Subject: Re: [Qemu-devel] [BUG] qemu-1.1.2 [FIXED-BY] qcow2: Fix avail_sectors in cluster allocation code List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf Cc: Michael Tokarev , qemu-devel@nongnu.org --nextPart2447119.LnC1BrpWTJ Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Hello Kevin, Am Mittwoch 12 Dezember 2012 17:54:58 schrieb Kevin Wolf: > Am 12.12.2012 15:09, schrieb Philipp Hahn: > > Am Mittwoch 12 Dezember 2012 14:41:49 schrieb Kevin Wolf: > >> As you can see in the commit message of that patch I was convinced that > >> no bug did exist in practice and this was only dangerous with respect = to > >> future changes. Therefore my first question is if you're using an > >> unmodified upstream qemu or if some backported patches are applied to > >> it? If it's indeed unmodified, we should probably review the code once > >> again to understand why it makes a difference. > > > > This were all unmodified versions directly from git between > > "qemu-kvm-1.1.0" and "qemu-kvm-1.2.0" > > > > "git checkout b7ab0fea37c15ca9e249c42c46f5c48fd1a0943c" works, > > "git checkout b7ab0fea37c15ca9e249c42c46f5c48fd1a0943c~1" is broken. > > "git checkout qemu-kvm-1.1.2" is broken, > > "git checkout qemu-kvm-1.1.2 ; git cherry-pick > > b7ab0fea37c15ca9e249c42c46f5c48fd1a0943c" works > > Ok, thanks for clarifying. Then I must have missed some interesting case > while doing the patch. I just re-run my "git bisect run ~/bisect.sh" case, but it again arrived a= t=20 that patch. I just queued another run for tonight so make sure the test is= =20 reliable: # bad: [4c3e02beed9878a5f760eeceb6cd42c475cf0127] Merge tag 'v1.2.0' # good: [bd11ac4feb54d32653e5d4eb7994bed18be0609c] fdc: fix implied seek wh= ile=20 there is no media in drive git bisect start 'qemu-kvm-1.2.0' 'qemu-kvm-1.1.0' # good: [15ecf28f39e2b6fba359ed094770c8fa4ad8dc60] Merge tag 'v1.1.0' into= =20 next git bisect good 15ecf28f39e2b6fba359ed094770c8fa4ad8dc60 # bad: [2fa5008ffd49e51540756adccf966a2fcde6e6c1] hd-geometry: Factor out=20 guess_chs_for_size() git bisect bad 2fa5008ffd49e51540756adccf966a2fcde6e6c1 # bad: [306a571a2d75e32cd2eae5486c2714b7b7792a63] hw/arm_gic: Add qdev=20 property for GIC revision git bisect bad 306a571a2d75e32cd2eae5486c2714b7b7792a63 # good: [5c6f4f178ba542358c012ca033985f73e61b8ae5] z2: Rename PXA2xxState=20 variable git bisect good 5c6f4f178ba542358c012ca033985f73e61b8ae5 # good: [833e40858cb9501c5e76b3aa345e4bb5be34385a] qcow2: remove a line of= =20 unnecessary code git bisect good 833e40858cb9501c5e76b3aa345e4bb5be34385a # bad: [0b0cb9d310edfe2b2d108f18be4f013a1e552cfd] Merge remote-tracking=20 branch 'kwolf/for-anthony' into staging git bisect bad 0b0cb9d310edfe2b2d108f18be4f013a1e552cfd # bad: [0446919dcab51e7468f346c0a009a88632c5c5e0] qemu-iotests: COW with ma= ny=20 AIO requests on the same cluster git bisect bad 0446919dcab51e7468f346c0a009a88632c5c5e0 # good: [b75a02829dde98723dfe16fa098338cb267b28b9] Prevent disk data loss w= hen=20 closing qemu git bisect good b75a02829dde98723dfe16fa098338cb267b28b9 # good: [c4a248a138028bee63a099410c79b428db0c4779] block: copy=20 enable_write_cache in bdrv_append git bisect good c4a248a138028bee63a099410c79b428db0c4779 # good: [6af4e9ead4ec9491259c9861b1b35f9abee24a66] qcow2: always operate=20 caches in writeback mode git bisect good 6af4e9ead4ec9491259c9861b1b35f9abee24a66 # bad: [b7ab0fea37c15ca9e249c42c46f5c48fd1a0943c] qcow2: Fix avail_sectors = in=20 cluster allocation code git bisect bad b7ab0fea37c15ca9e249c42c46f5c48fd1a0943c # good: [cdba7fee1daa8865bac2d69da288171fe7c21aae] qcow2: Simplify calculat= ion=20 for COW area at the end git bisect good cdba7fee1daa8865bac2d69da288171fe7c21aae > Ideally we would find a sequence of qemu-io commands to reliably > reproduce this. First thing worth trying would be running the current > qemu-iotests suite on the old versions. If we don't find it this way, I > guess we need to catch it with code review. I'm not sure if I can get to > it this week, and starting next week I'll be on vacation, so any help > with finding a reproducer would be appreciated. I'll have a look at it tommorrow. Thank you for your fast replies and have a nice vacation in case we don't h= ead=20 from each other this week again. BYtE Philipp =2D-=20 Philipp Hahn Open Source Software Engineer hahn@univention.de Univention GmbH be open. fon: +49 421 22 232- 0 Mary-Somerville-Str.1 D-28359 Bremen fax: +49 421 22 232-99 http://www.univention.de/ --nextPart2447119.LnC1BrpWTJ Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEABECAAYFAlDIvw0ACgkQYPlgoZpUDjllUwCgkc0AkXeXjMmZHGuAqetIa/oO zKoAoIEzJ0Y6NnjlNMte5wAxCF745Zxg =xdbJ -----END PGP SIGNATURE----- --nextPart2447119.LnC1BrpWTJ--