From: Julian Schroeder <jumaco@amazon.com>
Date: Mon, 23 May 2022 18:52:26 +0000
Subject: [PATCH] nfsd: destroy percpu stats counters after reply cache
shutdown
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Git-commit: fd5e363eac77ef81542db77ddad0559fa0f9204e
Patch-mainline: v5.19
References: git-fixes
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>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: NeilBrown <neilb@suse.com>
---
fs/nfsd/nfscache.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -212,7 +212,6 @@ void nfsd_reply_cache_shutdown(struct nf
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++) {
@@ -223,6 +222,7 @@ void nfsd_reply_cache_shutdown(struct nf
rp, nn);
}
}
+ nfsd_reply_cache_stats_destroy(nn);
kvfree(nn->drc_hashtbl);
nn->drc_hashtbl = NULL;