Re: [PATCH review 05/16] xfs: Update xfs_ioctl_setattr to handle projids in any user namespace

[Dave Chinner <david-FqsqvQoI3Ljby3iVrkZq2A@public.gmane.org>]

On Sun, Feb 17, 2013 at 05:10:58PM -0800, Eric W. Biederman wrote:
> From: "Eric W. Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
> 
> - Convert the userspace value in fa->fsx_projid into a kprojid and
>   store it in the variable projid.
> - Verify that xfs can store the projid after it is converted into
>   xfs's user namespace.
> - Replace uses of fa->fsx_projid with projid throughout
>   xfs_ioctl_setattr.
> 
> Cc: Ben Myers <bpm-sJ/iWh9BUns@public.gmane.org>
> Cc: Alex Elder <elder-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> Cc: Dave Chinner <david-FqsqvQoI3Ljby3iVrkZq2A@public.gmane.org>
> Signed-off-by: "Eric W. Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
> ---
>  fs/xfs/xfs_ioctl.c |   26 ++++++++++++++++++--------
>  1 files changed, 18 insertions(+), 8 deletions(-)
> 
> diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
> index 016624b..4a55f50 100644
> --- a/fs/xfs/xfs_ioctl.c
> +++ b/fs/xfs/xfs_ioctl.c
> @@ -925,6 +925,7 @@ xfs_ioctl_setattr(
>  	struct xfs_dquot	*gdqp = NULL;
>  	struct xfs_dquot	*olddquot = NULL;
>  	int			code;
> +	kprojid_t		projid = INVALID_PROJID;
>  
>  	trace_xfs_ioctl_setattr(ip);
>  
> @@ -934,11 +935,20 @@ xfs_ioctl_setattr(
>  		return XFS_ERROR(EIO);
>  
>  	/*
> -	 * Disallow 32bit project ids when projid32bit feature is not enabled.
> +	 * Verify the specifid project id is valid.
>  	 */
> -	if ((mask & FSX_PROJID) && (fa->fsx_projid > (__uint16_t)-1) &&
> -			!xfs_sb_version_hasprojid32bit(&ip->i_mount->m_sb))
> -		return XFS_ERROR(EINVAL);
> +	if (mask & FSX_PROJID) {
> +		projid = make_kprojid(current_user_ns(), fa->fsx_projid);
> +		if (!projid_valid(projid))
> +			return XFS_ERROR(EINVAL);
> +
> +		/*
> +		 * Disallow 32bit project ids when projid32bit feature is not enabled.
> +		 */
> +		if ((from_kprojid(&init_user_ns, projid) > (__uint16_t)-1) &&
> +		    !xfs_sb_version_hasprojid32bit(&ip->i_mount->m_sb))
> +			return XFS_ERROR(EINVAL);
> +	}

That looks busted. Why does one use current_user_ns() and the other
&init_user_ns()?

Cheers,

Dave.
-- 
Dave Chinner
david-FqsqvQoI3Ljby3iVrkZq2A@public.gmane.org