3 files changed, 22 insertions, 17 deletions

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 18b740bd29ac..d32f49d6ca2c 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -470,8 +470,6 @@ static int max_cb_time(void)
         return max(nfsd4_lease/10, (time_t)1) * HZ;
 }
 
-/* Reference counting, callback cleanup, etc., all look racy as heck.
- * And why is cl_cb_set an atomic? */
 
 static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
 {
@@ -526,14 +524,20 @@ static void warn_no_callback_path(struct nfs4_client *clp, int reason)
                 (int)clp->cl_name.len, clp->cl_name.data, reason);
 }
 
+static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
+{
+        clp->cl_cb_state = NFSD4_CB_DOWN;
+        warn_no_callback_path(clp, reason);
+}
+
 static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
 {
         struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
 
         if (task->tk_status)
-                warn_no_callback_path(clp, task->tk_status);
+                nfsd4_mark_cb_down(clp, task->tk_status);
         else
-                atomic_set(&clp->cl_cb_set, 1);
+                clp->cl_cb_state = NFSD4_CB_UP;
 }
 
 static const struct rpc_call_ops nfsd4_cb_probe_ops = {
@@ -579,14 +583,15 @@ static void do_probe_callback(struct nfs4_client *clp)
  */
 void nfsd4_probe_callback(struct nfs4_client *clp)
 {
+        /* XXX: atomicity?  Also, should we be using cl_cb_flags? */
+        clp->cl_cb_state = NFSD4_CB_UNKNOWN;
         set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_cb_flags);
         do_probe_callback(clp);
 }
 
 void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
 {
-        BUG_ON(atomic_read(&clp->cl_cb_set));
-
+        clp->cl_cb_state = NFSD4_CB_UNKNOWN;
         spin_lock(&clp->cl_lock);
         memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
         spin_unlock(&clp->cl_lock);
@@ -693,8 +698,7 @@ static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)
                 break;
         default:
                 /* Network partition? */
-                atomic_set(&clp->cl_cb_set, 0);
-                warn_no_callback_path(clp, task->tk_status);
+                nfsd4_mark_cb_down(clp, task->tk_status);
                 if (current_rpc_client != task->tk_client) {
                         /* queue a callback on the new connection: */
                         atomic_inc(&dp->dl_count);
@@ -707,10 +711,8 @@ static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)
                 task->tk_status = 0;
                 rpc_restart_call_prepare(task);
                 return;
-        } else {
-                atomic_set(&clp->cl_cb_set, 0);
-                warn_no_callback_path(clp, task->tk_status);
-        }
+        } else
+                nfsd4_mark_cb_down(clp, task->tk_status);
 }
 
 static void nfsd4_cb_recall_release(void *calldata)
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 290370bc9ae7..919ad25660d6 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1071,7 +1071,7 @@ static struct nfs4_client *create_client(struct xdr_netobj name, char *recdir,
 
         memcpy(clp->cl_recdir, recdir, HEXDIR_LEN);
         atomic_set(&clp->cl_refcount, 0);
-        atomic_set(&clp->cl_cb_set, 0);
+        clp->cl_cb_state = NFSD4_CB_UNKNOWN;
         INIT_LIST_HEAD(&clp->cl_idhash);
         INIT_LIST_HEAD(&clp->cl_strhash);
         INIT_LIST_HEAD(&clp->cl_openowners);
@@ -2003,7 +2003,6 @@ nfsd4_setclientid_confirm(struct svc_rqst *rqstp,
                 if (!same_creds(&conf->cl_cred, &unconf->cl_cred))
                         status = nfserr_clid_inuse;
                 else {
-                        atomic_set(&conf->cl_cb_set, 0);
                         nfsd4_change_callback(conf, &unconf->cl_cb_conn);
                         nfsd4_probe_callback(conf);
                         expire_client(unconf);
@@ -2633,7 +2632,8 @@ nfs4_open_delegation(struct svc_fh *fh, struct nfsd4_open *open, struct nfs4_sta
 {
         struct nfs4_delegation *dp;
         struct nfs4_stateowner *sop = stp->st_stateowner;
-        int cb_up = atomic_read(&sop->so_client->cl_cb_set);
+        /* XXX: or unknown and nfsv4.1: */
+        int cb_up = (sop->so_client->cl_cb_state == NFSD4_CB_UP);
         struct file_lock *fl;
         int status, flag = 0;
 
@@ -2823,7 +2823,7 @@ nfsd4_renew(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         renew_client(clp);
         status = nfserr_cb_path_down;
         if (!list_empty(&clp->cl_delegations)
-                        && !atomic_read(&clp->cl_cb_set))
+                        && clp->cl_cb_state != NFSD4_CB_UP)
                 goto out;
         status = nfs_ok;
 out:
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index 442f6d8e024c..32ff615c36f4 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -242,7 +242,10 @@ struct nfs4_client {
         unsigned long           cl_cb_flags;
         struct rpc_clnt         *cl_cb_client;
         u32                     cl_cb_ident;
-        atomic_t                cl_cb_set;
+#define NFSD4_CB_UP             0
+#define NFSD4_CB_UNKNOWN        1
+#define NFSD4_CB_DOWN           2
+        int                     cl_cb_state;
         struct nfsd4_callback   cl_cb_null;
         struct nfsd4_session    *cl_cb_session;