Subject: Re: [PATCH 2/4] svcrpc: fix error-handling on badd gssproxy
 downcall
From: Simo Sorce <simo@redhat.com>
To: "J. Bruce Fields" <bfields@redhat.com>
Cc: linux-nfs@vger.kernel.org
In-Reply-To: <1381418103-3852-3-git-send-email-bfields@redhat.com>
References: <1381418103-3852-1-git-send-email-bfields@redhat.com>
	 <1381418103-3852-3-git-send-email-bfields@redhat.com>
Content-Type: text/plain; charset="UTF-8"
Date: Thu, 10 Oct 2013 11:37:12 -0400
Message-ID: <1381419432.2684.15.camel@willson.li.ssimo.org>
Mime-Version: 1.0
Sender: linux-nfs-owner@vger.kernel.org

On Thu, 2013-10-10 at 11:15 -0400, J. Bruce Fields wrote:
> From: "J. Bruce Fields" <bfields@redhat.com>
> 
> For every other problem here we bail out with an error, but here for
> some reason we're setting a negative cache entry (with, note, an
> undefined expiry).
> 
> It seems simplest just to bail out in the same way as we do in other
> cases.
> 
> Cc: Simo Sorce <simo@redhat.com>
> Reported-by: Andi Kleen <andi@firstfloor.org>
> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
> ---
>  net/sunrpc/auth_gss/svcauth_gss.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
> index 09fb638..008cdad 100644
> --- a/net/sunrpc/auth_gss/svcauth_gss.c
> +++ b/net/sunrpc/auth_gss/svcauth_gss.c
> @@ -1167,8 +1167,8 @@ static int gss_proxy_save_rsc(struct cache_detail *cd,
>  	if (!ud->found_creds) {
>  		/* userspace seem buggy, we should always get at least a
>  		 * mapping to nobody */
> -		dprintk("RPC:       No creds found, marking Negative!\n");
> -		set_bit(CACHE_NEGATIVE, &rsci.h.flags);
> +		dprintk("RPC:       No creds found!\n");
> +		goto out;
>  	} else {
>  
>  		/* steal creds */

IIRC, we are doing this to avoid rapid upcall loops in the kernel, where
we keep hammering upcalls out and keep getting an error back.
I am not sure it is wise to not set a temp negative cache here.

Simo.

-- 
Simo Sorce * Red Hat, Inc * New York