This is a note to let you know that I've just added the patch titled
nfsd: destroy percpu stats counters after reply cache shutdown
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
nfsd-destroy-percpu-stats-counters-after-reply-cache.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3154b26d1dbbdd5ceb793e04c1d4d7ce42f0d994
Author: Julian Schroeder <jumaco@xxxxxxxxxx>
Date: Mon May 23 18:52:26 2022 +0000
nfsd: destroy percpu stats counters after reply cache shutdown
[ Upstream commit fd5e363eac77ef81542db77ddad0559fa0f9204e ]
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@xxxxxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
index 0b3f12aa37ff5..7da88bdc0d6c3 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;
