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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, "J. Bruce Fields" <bfields@redhat.com>,
        Chuck Lever <chuck.lever@oracle.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.10 166/236] nfsd4: Fix forced-expiry locking
Date:   Mon, 13 Sep 2021 15:14:31 +0200
Message-Id: <20210913131106.020822412@linuxfoundation.org>
In-Reply-To: <20210913131100.316353015@linuxfoundation.org>
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From: J. Bruce Fields <bfields@redhat.com>

[ Upstream commit f7104cc1a9159cd0d3e8526cb638ae0301de4b61 ]

This should use the network-namespace-wide client_lock, not the
per-client cl_lock.

You shouldn't see any bugs unless you're actually using the
forced-expiry interface introduced by 89c905beccbb.

Fixes: 89c905beccbb "nfsd: allow forced expiration of NFSv4 clients"
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/nfsd/nfs4state.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 80e394a2e3fd..142aac9b63a8 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -2646,9 +2646,9 @@ static void force_expire_client(struct nfs4_client *clp)
 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
 	bool already_expired;
 
-	spin_lock(&clp->cl_lock);
+	spin_lock(&nn->client_lock);
 	clp->cl_time = 0;
-	spin_unlock(&clp->cl_lock);
+	spin_unlock(&nn->client_lock);
 
 	wait_event(expiry_wq, atomic_read(&clp->cl_rpc_users) == 0);
 	spin_lock(&nn->client_lock);
-- 
2.30.2