Re: [PATCH] nfsd: destroy percpu stats counters after reply cache #5.11.0-rc5

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, May 23, 2022 at 09:11:52PM +0000, Julian Schroeder wrote:
> From: Julian Schroeder <jumaco@amazon.com>
> Date: Fri, 20 May 2022 18:33:27 +0000
> Subject: [PATCH] nfsd: destroy percpu stats counters after reply cache
>  shutdown
> MIME-Version: 1.0
> Content-Type: text/plain; charset=UTF-8
> Content-Transfer-Encoding: 8bit
> Upon nfsd shutdown any pending DRC cache is freed. DRC cache use is
> tracked via a percpu counter. In the current code the percpu counter
> is destroyed before. If any pending cache is still present,
> percpu_counter_add is called with a percpu counter==NULL. This causes
> a kernel crash.
> The solution is to destroy the percpu counter after the cache is freed.
> Fixes: e567b98ce9a4b (“nfsd: protect concurrent access to nfsd stats counters”)
> Signed-off-by: Julian Schroeder <jumaco@amazon.com>
> ---
>  fs/nfsd/nfscache.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
> index 0b3f12aa37ff..7da88bdc0d6c 100644
> --- a/fs/nfsd/nfscache.c
> +++ b/fs/nfsd/nfscache.c
> @@ -206,7 +206,6 @@ void nfsd_reply_cache_shutdown(struct nfsd_net *nn)
>         struct svc_cacherep     *rp;
>         unsigned int i;
>  
> -       nfsd_reply_cache_stats_destroy(nn);
>         unregister_shrinker(&nn->nfsd_reply_cache_shrinker);
>  
>         for (i = 0; i < nn->drc_hashsize; i++) {
> @@ -217,6 +216,7 @@ void nfsd_reply_cache_shutdown(struct nfsd_net *nn)
>                                                                         rp, nn);
>                 }
>         }
> +       nfsd_reply_cache_stats_destroy(nn);
>  
>         kvfree(nn->drc_hashtbl);
>         nn->drc_hashtbl = NULL;
> -- 
> 2.32.0
> 

What is the git commit id of this in Linus's tree?

And this patch is totally damaged with whitespace and can not be applied
at all :(

Please fix it up and submit it again.

thanks,

greg k-h