Re: [PATCH 1/6] SUNRPC: Fix a bug in rpcauth_lookup_credcache()

["J. Bruce Fields" <bfields@fieldses.org>]

Sorry for the delayed response--I read over these offline and them
forgot about them....:

On Thu, Mar 13, 2008 at 01:48:07PM -0400, Trond Myklebust wrote:
> The hash bucket is for some reason always being set to zero.

The changelog seems out of sync with the code; nr is normally set a
little lower to the low bits of acred->uid:

...
> @@ -280,7 +281,9 @@ rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
>  	struct hlist_node *pos;
>  	struct rpc_cred	*cred = NULL,
>  			*entry, *new;
> -	int		nr = 0;
> +	unsigned int nr;
> +
> +	nr = hash_long(acred->uid, RPC_CREDCACHE_HASHBITS);
>  
>  	if (!(flags & RPCAUTH_LOOKUP_ROOTCREDS))
>  		nr = acred->uid & RPC_CREDCACHE_MASK;

So what you're really doing is switching to a better hash fn.  (Except
that the result is being overwritten immediately afterwards in the
!RPCAUTH_LOOKUP_ROOTRCREDS case.)

Wouldn't it have made more sense to replace the existing assignment,
then remove just make it unconditional in next patch?

--b.