On Sat, May 28, 2022 at 01:41:51PM +0000, Schroeder, Julian wrote:
> >> From: Julian Schroeder <jumaco@xxxxxxxxxx>
> >> 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 (âEURoenfsd: protect concurrent access to nfsd stats countersâEUR?)
> >> Signed-off-by: Julian Schroeder <jumaco@xxxxxxxxxx>
> >> ---
> >> 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
>
> The patch made it into linux next. commit fd5e363eac77e.
> I sent the patch to stable again via git send-email (https://www.spinics.net/lists/stable/msg560818.html)
<formletter>
This is not the correct way to submit patches for inclusion in the
stable kernel tree. Please read:
https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.
</formletter>
