Re: [Patch] BUG in fs/jfs/jfs_xtree.c

[Dave Kleikamp <shaggy@linux.vnet.ibm.com>]

On Mon, 2006-12-18 at 19:51 +0100, Eric Sesterhenn wrote:
> hi,
> 
> while playing around with fsfuzzer, i got the following oops with jfs:
> 
> [  851.804875] BUG at fs/jfs/jfs_xtree.c:760 assert(!BT_STACK_FULL(btstack))

... 

> On a damaged filesystem we might have a full stack and should
> not progress further, and return instead of calling BUG()
> 
> Signed-off-by: Eric Sesterhenn
> 
> --- linux-2.6.19/fs/jfs/jfs_xtree.c.orig	2006-12-18 14:37:07.000000000 +0100
> +++ linux-2.6.19/fs/jfs/jfs_xtree.c	2006-12-18 14:37:55.000000000 +0100
> @@ -757,6 +757,8 @@ static int xtSearch(struct inode *ip, s6
>  			nsplit = 0;
>  
>  		/* push (bn, index) of the parent page/entry */
> +		if (BT_STACK_FULL(btstack))
> +			return -EINVAL;
>  		BT_PUSH(btstack, bn, index);
>  
>  		/* get the child page block number */
> 

I typically return -EIO for metadata-corruption problems.  I also want
to look at the other places in jfs_xtree.c that call BT_PUSH.  I'm on
vacation today, so I'll take a closer look at this tomorrow and push it
upstream.

Thanks!
Shaggy
-- 
David Kleikamp
IBM Linux Technology Center