From mboxrd@z Thu Jan  1 00:00:00 1970
From: Miklos Szeredi <miklos@szeredi.hu>
Subject: Re: overlayfs patches for ovl_copy_up & ovl_rename
Date: Tue, 17 May 2011 10:43:39 +0200
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To: Jordi Pujol <jordipujolp@gmail.com>
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In-Reply-To: <87zkmujzni.fsf@tucsk.pomaz.szeredi.hu> (Miklos Szeredi's message
	of "Tue, 10 May 2011 18:20:17 +0200")
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Miklos Szeredi <miklos@szeredi.hu> writes:

> Jordi Pujol <jordipujolp@gmail.com> writes:
>>
>> In my tests, locking the parent directories makes the right thing,
>> but maybe there are other cases that should be considered...
>
> Can you please try the following patch then?  Does any of the WARN_ONs
> trigger when you observe the bad behavior?

Jordi, what's up with this?

Could you please test the .v8 codebase with this single patch applied?

Thanks,
Miklos


> ---
>  fs/overlayfs/dir.c |   10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> Index: linux-2.6/fs/overlayfs/dir.c
> ===================================================================
> --- linux-2.6.orig/fs/overlayfs/dir.c	2011-05-10 18:13:03.000000000 +0200
> +++ linux-2.6/fs/overlayfs/dir.c	2011-05-10 18:16:13.000000000 +0200
> @@ -512,6 +512,9 @@ static int ovl_rename(struct inode *oldd
>  	old_upperdir = ovl_dentry_upper(old->d_parent);
>  	new_upperdir = ovl_dentry_upper(new->d_parent);
>  
> +	(void) dget(old_upperdir);
> +	(void) dget(new_upperdir);
> +
>  	trap = lock_rename(new_upperdir, old_upperdir);
>  
>  	olddentry = ovl_dentry_upper(old);
> @@ -571,6 +574,13 @@ static int ovl_rename(struct inode *oldd
>  	dput(newdentry);
>  out_unlock:
>  	unlock_rename(new_upperdir, old_upperdir);
> +
> +	WARN_ON(old_upperdir->d_count == 1);
> +	WARN_ON(new_upperdir->d_count == 1);
> +
> +	dput(old_upperdir);
> +	dput(new_upperdir);
> +
>  	return err;
>  }
>