From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vegard Nossum Subject: Re: ext4: fix reference counting bug on block allocation error Date: Sun, 14 Aug 2016 21:35:59 +0200 Message-ID: <57B0C81F.9000309@oracle.com> References: <20160727052921.5B41C35574@git2.kroah.org> <20160814183206.GA11040@kroah.com> <57B0BA84.1000600@oracle.com> <20160814185125.GA4077@kroah.com> <20160814185805.GA8087@kroah.com> <57B0C058.9010800@oracle.com> <20160814190919.GA9517@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: "Theodore Ts'o" , adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, "Aneesh Kumar K.V" To: Greg KH Return-path: Received: from aserp1040.oracle.com ([141.146.126.69]:50186 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750745AbcHNTgJ (ORCPT ); Sun, 14 Aug 2016 15:36:09 -0400 In-Reply-To: <20160814190919.GA9517@kroah.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On 08/14/2016 09:09 PM, Greg KH wrote: > On Sun, Aug 14, 2016 at 09:02:48PM +0200, Vegard Nossum wrote: >> The commit which is being fixed is ancient: >> >> $ git describe 8556e8f3b6 >> v2.6.28-5758-g8556e8f3 >> >> It's probably already in the base of every current stable tree, no? > > Huh? Ok, this odd: > $ git describe --contains 8556e8f3b6 > fatal: cannot describe '8556e8f3b6c4c11601ce1e9ea8090a6d8bd5daae' > > Yet just a plain 'git describe' does work... > > That's what threw me off, I only use --contains as that shows the > release the commit is in. > > Ok, that makes me feel a bit better (that my scripts didn't miss the > patch, it was just old), but I wonder what is going on with git... > How odd. There is this: http://www.spinics.net/lists/git/msg246837.html """ Yes, the "describe --contains" algorithm uses timestamps to cut off the traversal, so it can do the wrong thing if there's clock skew. It has a "slop" margin of one day, but skew larger than that can fool it. """ It looks like ancestors of 87d8fe1 don't work: $ for commit in $(git rev-list 87d8fe1^^..87d8fe1); do git describe --contains $commit; done v2.6.29-rc1~40^2~12 fatal: cannot describe '0087d9fb3f29f59e8d42c8b058376d80e5adde4c' So maybe it's because the parent commit is 2 days in the future: $ git log --format=fuller 87d8fe1^^..87d8fe1 commit 87d8fe1ee6b8d2f95076142d58c440dba4e7bdc2 Author: Theodore Ts'o AuthorDate: Sat Jan 3 09:47:09 2009 -0500 Commit: Theodore Ts'o CommitDate: Sat Jan 3 09:47:09 2009 -0500 [...] commit 0087d9fb3f29f59e8d42c8b058376d80e5adde4c Author: Aneesh Kumar K.V AuthorDate: Mon Jan 5 21:49:12 2009 -0500 Commit: Theodore Ts'o CommitDate: Mon Jan 5 21:49:12 2009 -0500 [...] Vegard