nfsd: destroy percpu stats counters after reply cache shutdown

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: e567b98ce9 (“nfsd: protect concurrent access to nfsd stats counters”)
Signed-off-by: Julian Schroeder <jumaco@amazon.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This commit is contained in:
Julian Schroeder 2022-05-23 18:52:26 +00:00 committed by Chuck Lever
parent 6f6f84aa21
commit fd5e363eac

View file

@ -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;