From: Peter Zijlstra Subject: Re: kernel BUG at fs/ext/super.c:428 Date: Sat, 24 Jan 2009 08:36:35 +0100 Message-ID: <1232782595.4859.3.camel@laptop> References: <20090110003645.GA16107@linux-os.sc.intel.com> <20090113164842.c6aa7095.akpm@linux-foundation.org> <20090114014434.GE14730@mit.edu> <496D526D.1010402@linux.intel.com> <20090114044059.GA6222@mit.edu> <20090114191632.GA13114@linux-os.sc.intel.com> <1231961377.14825.51.camel@laptop> <20090114212038.GJ6222@mit.edu> <1232568618.16682.20.camel@jamoon.sc.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Theodore Tso , Arjan van de Ven , Andrew Morton , "linux-kernel@vger.kernel.org" , "linux-ext4@vger.kernel.org" , Ingo Molnar , Nick Piggin , Darren Hart To: "Pallipadi, Venkatesh" Return-path: Received: from casper.infradead.org ([85.118.1.10]:57114 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752527AbZAXHgu (ORCPT ); Sat, 24 Jan 2009 02:36:50 -0500 In-Reply-To: <1232568618.16682.20.camel@jamoon.sc.intel.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Wed, 2009-01-21 at 12:10 -0800, Pallipadi, Venkatesh wrote: > On Wed, 2009-01-14 at 13:20 -0800, Theodore Tso wrote: > > On Wed, Jan 14, 2009 at 08:29:37PM +0100, Peter Zijlstra wrote: > > > > 38d47c1b7075bd7ec3881141bb3629da58f88dab is first bad commit > > > > commit 38d47c1b7075bd7ec3881141bb3629da58f88dab > > > > Author: Peter Zijlstra > > > > Date: Fri Sep 26 19:32:20 2008 +0200 > > > > > > > > futex: rely on get_user_pages() for shared futexes > > > > > > > > On the way of getting rid of the mmap_sem requirement for s= hared futexes, > > > > start by relying on get_user_pages(). > > > > > > > > Signed-off-by: Peter Zijlstra > > > > Acked-by: Nick Piggin > > > > Signed-off-by: Ingo Molnar > > > > > > > However does a futex change make ext3 crap its pants? > >=20 > > I agree, this doesn't make much sense. I've looked at the patch, a= nd > > I don't see how this would cause an ext3 orphaned-inode list handli= ng > > problem > >=20 > > Are you sure the bisect was done correctly? Have you tried reverti= ng > > that one commit, or otherwise conclusively shown that a kernel with > > this commit fails, and one without this commit works just fine? > >=20 >=20 > Unfortunately, I cannot revert this patch alone from upstream git. > But I consistently see > upstream git: Always produces this oops on reboot > checkout of =EF=BB=BF38d47c1b: Always produces this oops on reboot > checkout of =EF=BB=BF=EF=BB=BF94aca1da (one patch before the above co= mmit): Reboots fine > without the oops. >=20 > This is petty specific to the particular userspace, looks like. > I only see this on SLES10 installation. Also, I need a non-root user > logged in at least once after boot through X to see this problem. I w= as > always seeing this as I had autologin on local terminal and was remot= ely > rebooting the system. If I just boot to init 3 or boot to init 5 with= no > user logged in or boot to init 5 with root logged in, I do not see th= is > problem. Ted, could this happen due an extra iput()? In that case, Venki, does the below patch fix it? Credit goes to Darren for spotting this. --- kernel/futex.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/kernel/futex.c b/kernel/futex.c index f89d373..f4132ab 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -929,7 +929,7 @@ out_unlock: =20 /* drop_futex_key_refs() must be called outside the spinlocks. */ while (--drop_count >=3D 0) - drop_futex_key_refs(&key1); + drop_futex_key_refs(&key2); =20 out_put_keys: put_futex_key(fshared, &key2); -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html