Re: ext3: kernel BUG at fs/jbd/journal.c:412!

["Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>]

On Thu, Nov 06, 2008 at 12:13:22PM -0500, Theodore Tso wrote:
> 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);
> 
> 

you would need the same patch for jbd2

-aneesh