Re: [PATCH -V1 09/22] vfs: Make acl_permission_check() work for richacls

Dave Chinner
2014-04-29T00:20:46Z

On Sun, Apr 27, 2014 at 09:44:40PM +0530, Aneesh Kumar K.V wrote:
> From: Andreas Gruenbacher <agruen@kernel.org>
>
> Signed-off-by: Andreas Gruenbacher <agruen@kernel.org>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> ---
> fs/namei.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/fs/namei.c b/fs/namei.c
> index 26b9a8212837..06474553c08d 100644
> --- a/fs/namei.c
> +++ b/fs/namei.c
> @@ -284,6 +284,19 @@ static int acl_permission_check(struct inode *inode, int mask)
> {
> unsigned int mode = inode->i_mode;
>
> + if (IS_RICHACL(inode)) {
> + int error = check_acl(inode, mask);
> + if (error != -EAGAIN)
> + return error;
> + if (mask & (MAY_DELETE_SELF | MAY_TAKE_OWNERSHIP |
> + MAY_CHMOD | MAY_SET_TIMES)) {
> + /*
> + * The file permission bit cannot grant these
> + * permissions.
> + */
> + return -EACCES;
> + }
> + }
> if (likely(uid_eq(current_fsuid(), inode->i_uid)))
> mode >>= 6;
> else {

why does this take priority over a simple uid match? Some comments
explaining this for people unfamiliar with richacls would be nice.
Not to mention the commit message should also explain the change...

Cheers,

Dave.
--
Dave Chinner
david@fromorbit.com