From: Theodore Tso Subject: Re: ext3: kernel BUG at fs/jbd/journal.c:412! Date: Thu, 6 Nov 2008 12:13:22 -0500 Message-ID: <20081106171322.GD18939@mit.edu> References: <20081106155025.GE25194@skywalker> <20081106161227.GA9254@ajones-laptop.nbttech.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "Aneesh Kumar K.V" , Ext4 Developers List To: Arthur Jones Return-path: Received: from www.church-of-our-saviour.org ([69.25.196.31]:51674 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750816AbYKFRN1 (ORCPT ); Thu, 6 Nov 2008 12:13:27 -0500 Content-Disposition: inline In-Reply-To: <20081106161227.GA9254@ajones-laptop.nbttech.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Thu, Nov 06, 2008 at 08:12:27AM -0800, Arthur Jones wrote: > Hi Aneesh, ... > > On Thu, Nov 06, 2008 at 07:50:25AM -0800, Aneesh Kumar K.V wrote: > > I get this with ext4-patchqueue. I guess we have some ext3 patches queued there. > > This could be related to a patch I just posted. > > See the thread on linux-ext4 called "ext3: slow symlink corruption > on umount" for details on how this patch came about... No this is the other ext3 patch we have in the patch tree. I see the problem, we're calling __log_space_left in a diagnostic printk after we've released the j_state_lock. Here's the incremental fix: diff --git a/fs/jbd/checkpoint.c b/fs/jbd/checkpoint.c index 5e856de..18e5137 100644 --- a/fs/jbd/checkpoint.c +++ b/fs/jbd/checkpoint.c @@ -115,7 +115,7 @@ static int __try_to_free_cp_buf(struct journal_head *jh) */ void __log_wait_for_space(journal_t *journal) { - int nblocks; + int nblocks, space_left; assert_spin_locked(&journal->j_state_lock); nblocks = jbd_space_needed(journal); @@ -139,7 +139,8 @@ void __log_wait_for_space(journal_t *journal) spin_lock(&journal->j_state_lock); spin_lock(&journal->j_list_lock); nblocks = jbd_space_needed(journal); - if (__log_space_left(journal) < nblocks) { + space_left = __log_space_left(journal); + if (space_left < nblocks) { int chkpt = journal->j_checkpoint_transactions != NULL; int tid = 0; @@ -157,8 +158,7 @@ void __log_wait_for_space(journal_t *journal) } else { printk(KERN_ERR "%s: needed %d blocks and " "only had %d space available\n", - __func__, nblocks, - __log_space_left(journal)); + __func__, nblocks, space_left); printk(KERN_ERR "%s: no way to get more " "journal space\n", __func__); WARN_ON(1); This is in a "should never happen path", though. What were you doing to trigger it? - Ted