From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tvrtko Ursulin Subject: Re: Potentially unbounded allocations in seq_read? Date: Thu, 12 Dec 2013 14:52:32 +0000 Message-ID: <1386859952.6066.80.camel@tursulin-linux.isw.intel.com> References: <1386781481.6066.55.camel@tursulin-linux.isw.intel.com> <20131211174909.GW10323@ZenIV.linux.org.uk> <1386784797.6066.63.camel@tursulin-linux.isw.intel.com> <20131211180703.GY10323@ZenIV.linux.org.uk> <1386855640.6066.73.camel@tursulin-linux.isw.intel.com> <20131212134956.GC10323@ZenIV.linux.org.uk> <1386856771.6066.77.camel@tursulin-linux.isw.intel.com> <20131212142157.GD10323@ZenIV.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Andrew Morton , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org To: Al Viro Return-path: Received: from mga09.intel.com ([134.134.136.24]:12586 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751663Ab3LLOwf (ORCPT ); Thu, 12 Dec 2013 09:52:35 -0500 In-Reply-To: <20131212142157.GD10323@ZenIV.linux.org.uk> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Thu, 2013-12-12 at 14:21 +0000, Al Viro wrote: > On Thu, Dec 12, 2013 at 01:59:31PM +0000, Tvrtko Ursulin wrote: > > > > a) *what* errors other than -ENAMETOOLONG? > > > > Is this your way of saying there can't be any other errors from d_path? > > Check yourself... It is the only error that makes sense there and yes, > it is the only one being returned. Cool then, thats why I e-mailed you in the first place, because you know this area very well. > > > b) d_path() not fitting into 2Mb is definitely a bug. If you really have > > > managed to get a dentry tree 1 million levels deep, you have much worse > > > problems. > > > c) which kernel version it is? > > > > 3.10. I can't imagine this is an actual dentry tree somewhere, probably > > just a bug of some sort. I'll probably hunt it down completely some time > > next week, time permitting. > > Sounds like missing backport of 118b23 ("cope with potentially long ->d_dname() > output for shmem/hugetlb"). It *is* in -stable (linux-3.10.y has it since > 3.10.17 as commit ad4c3c), but if your tree doesn't have it, that's the one > to try first... Yes that fixed it, thanks! Regards, Tvrtko