From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ted Ts'o Subject: Re: ext4 crash on 2.6.37: NULL ptr in ext4_discard_preallocations Date: Sun, 20 Feb 2011 01:15:52 -0500 Message-ID: <20110220061552.GB8765@thunk.org> References: <4D604620.9060204@teksavvy.com> <20110220000550.GA8765@thunk.org> <4D609E87.5000903@teksavvy.com> <4D60A117.8090604@teksavvy.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Linux Kernel , linux-ext4@vger.kernel.org To: Mark Lord Return-path: Received: from li9-11.members.linode.com ([67.18.176.11]:42879 "EHLO test.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750760Ab1BTGPz (ORCPT ); Sun, 20 Feb 2011 01:15:55 -0500 Content-Disposition: inline In-Reply-To: <4D60A117.8090604@teksavvy.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Sun, Feb 20, 2011 at 12:05:27AM -0500, Mark Lord wrote: > I suppose it must be, as there's no other 0x3c offset in that function. > Which means it's probably this line that's crashing: > > BUG_ON(pa->pa_obj_lock != &ei->i_prealloc_lock); > > ...which could only happen if "pa" was NULL there. > I wonder how that happened ? Which could only happen if ei->i_prealloc_list were not properly initialized (i..e, it was still NULL). Which shouldn't ever happen...., since all ext4_inodes are initialized in ext4_alloc_inode(). Hmm, can you replicate the crash? - Ted