nfsd: rpc_peeraddr2str needs rcu lock

I'm not even sure cl_xprt can change here, but we're getting "suspicious
RCU usage" warnings, and other rpc_peeraddr2str callers are taking the
rcu lock.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 84401ca047053d1effdd2782f36bb4f823b7de68..0f8b10f363e7f3dba63d514f07def9621e8fc796 100644 (file)
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -939,8 +939,10 @@ static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *c
        }
        clp->cl_cb_client = client;
        clp->cl_cb_cred = cred;
+       rcu_read_lock();
        trace_nfsd_cb_setup(clp, rpc_peeraddr2str(client, RPC_DISPLAY_NETID),
                            args.authflavor);
+       rcu_read_unlock();
        return 0;
 }