[Unionfs] Kernel panic

[Erez Zadok]

In message <200710230307.l9N37ceo016410 at agora.fsl.cs.sunysb.edu>, Erez Zadok writes:
> In message <200710221704.48530.fapg-unionfs at eurotux.com>, "Fernando A. P. Gomes" writes:
[...]
> Yes, I need more info.  How are the mounts configured?  Any chroot or
> pivot_root stuff?  What commands are running when this oops happens?  Is
> this a live-cd?  Can I get an image of this livecd?  (I asked before if
> you're using vmware and if so, can I get an image of your VM to reproduce
> the bug here).
> 
> The hardest part is always reproducing a bug: fixing it is relatively easy
> thereafter.
> 
> Can you try this small patch on top of 2.1.7 and let me know if you can
> trigger any of these two BUG_ON's in this patch?
> 
> Thanks,
> Erez.
> 
> diff --git a/fs/unionfs/commonfops.c b/fs/unionfs/commonfops.c
> index 7654bcb..a66a6b6 100644
> --- a/fs/unionfs/commonfops.c
> +++ b/fs/unionfs/commonfops.c
> @@ -803,6 +803,8 @@ int unionfs_flush(struct file *file, fl_owner_t id)
>  		goto out;
>  	unionfs_check_file(file);
>  
> +	BUG_ON(!dentry->d_inode);
> +	BUG_ON(!UNIONFS_I(dentry->d_inode);
>  	if (!atomic_dec_and_test(&UNIONFS_I(dentry->d_inode)->totalopens))
>  		goto out;

BTW, sorry for the typo in the above small patch.  The second BUG_ON line
was missing a closing ")".

Erez.