nfsd: add tracepoint in mark_client_expired_locked

Show client info alongside the number of cl_rpc_users. If that's
elevated, then we can infer that this function returned nfserr_jukebox.

[ cel: For additional debugging of RPC user refcounting ]

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Vladimir Benes <vbenes@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index bd81217ada7f7737a23d89da0658ca67d51cf8e6..66f9a4f031a4d77344d1c1420ca09e95033c948d 100644 (file)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -2347,7 +2347,11 @@ unhash_client(struct nfs4_client *clp)
 
 static __be32 mark_client_expired_locked(struct nfs4_client *clp)
 {
-       if (atomic_read(&clp->cl_rpc_users))
+       int users = atomic_read(&clp->cl_rpc_users);
+
+       trace_nfsd_mark_client_expired(clp, users);
+
+       if (users)
                return nfserr_jukebox;
        unhash_client_locked(clp);
        return nfs_ok;

diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h
index ac2124461a08fef7352be5718b633ae1fdf6d755..b5e48d504062dd8fc5e7f2c3cb1184027d72f0c9 100644 (file)
--- a/fs/nfsd/trace.h
+++ b/fs/nfsd/trace.h
@@ -848,6 +848,30 @@ DEFINE_CLIENTID_EVENT(purged);
 DEFINE_CLIENTID_EVENT(renew);
 DEFINE_CLIENTID_EVENT(stale);
 
+TRACE_EVENT(nfsd_mark_client_expired,
+       TP_PROTO(
+               const struct nfs4_client *clp,
+               int cl_rpc_users
+       ),
+       TP_ARGS(clp, cl_rpc_users),
+       TP_STRUCT__entry(
+               __field(int, cl_rpc_users)
+               __field(u32, cl_boot)
+               __field(u32, cl_id)
+               __sockaddr(addr, clp->cl_cb_conn.cb_addrlen)
+       ),
+       TP_fast_assign(
+               __entry->cl_rpc_users = cl_rpc_users;
+               __entry->cl_boot = clp->cl_clientid.cl_boot;
+               __entry->cl_id = clp->cl_clientid.cl_id;
+               __assign_sockaddr(addr, &clp->cl_cb_conn.cb_addr,
+                                 clp->cl_cb_conn.cb_addrlen)
+       ),
+       TP_printk("addr=%pISpc client %08x:%08x cl_rpc_users=%d",
+               __get_sockaddr(addr), __entry->cl_boot, __entry->cl_id,
+               __entry->cl_rpc_users)
+);
+
 DECLARE_EVENT_CLASS(nfsd_net_class,
        TP_PROTO(const struct nfsd_net *nn),
        TP_ARGS(nn),