Re: [PATCH] blkdev: cgroup whitelist permission fix

["Serge E. Hallyn" <serue@us.ibm.com>]

Quoting Chris Wright (chrisw@sous-sol.org):
> The cgroup device whitelist code gets confused when trying to grant
> permission to a disk partition that is not currently open.  Part of
> blkdev_open() includes __blkdev_get() on the whole disk.  This simply
> avoids the cgroup check for the whole disk case when opening a
> partition.
> 
> https://bugzilla.redhat.com/show_bug.cgi?id=589662
> 
> Signed-off-by: Chris Wright <chrisw@sous-sol.org>

Thanks, Chris, sorry for the delay.

Acked-by: Serge E. Hallyn <serue@us.ibm.com>
Tested-by: Serge E. Hallyn <serue@us.ibm.com>

> ---
>  fs/block_dev.c |   10 ++++++----
>  1 files changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/block_dev.c b/fs/block_dev.c
> index 6dcee88..d4d19ac 100644
> --- a/fs/block_dev.c
> +++ b/fs/block_dev.c
> @@ -1192,10 +1192,12 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
>  	/*
>  	 * hooks: /n/, see "layering violations".
>  	 */
> -	ret = devcgroup_inode_permission(bdev->bd_inode, perm);
> -	if (ret != 0) {
> -		bdput(bdev);
> -		return ret;
> +	if (!for_part) {
> +		ret = devcgroup_inode_permission(bdev->bd_inode, perm);
> +		if (ret != 0) {
> +			bdput(bdev);
> +			return ret;
> +		}
>  	}
> 
>  	lock_kernel();