nfsd4: fix callback restarting

Ensure a new callback is added to the client's list of callbacks at most
once.

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

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 209e186386a00c3d6a4f9f7cfcd4eea27847fc86..ae93c5c83e87017b78343c5ec3b50dfc40c0863c 100644 (file)
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -639,9 +639,12 @@ static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
                if (!nfsd41_cb_get_slot(clp, task))
                        return;
        }
-       cb->cb_done = false;
        spin_lock(&clp->cl_lock);
-       list_add(&cb->cb_per_client, &clp->cl_callbacks);
+       if (list_empty(&cb->cb_per_client)) {
+               /* This is the first call, not a restart */
+               cb->cb_done = false;
+               list_add(&cb->cb_per_client, &clp->cl_callbacks);
+       }
        spin_unlock(&clp->cl_lock);
        rpc_call_start(task);
 }
@@ -678,10 +681,10 @@ static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)
 
        nfsd4_cb_done(task, calldata);
 
-       if (current_rpc_client == NULL) {
-               /* We're shutting down; give up. */
-               /* XXX: err, or is it ok just to fall through
-                * and rpc_restart_call? */
+       if (current_rpc_client != task->tk_client) {
+               /* We're shutting down or changing cl_cb_client; leave
+                * it to nfsd4_process_cb_update to restart the call if
+                * necessary. */
                return;
        }
 
@@ -699,12 +702,6 @@ static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)
        default:
                /* Network partition? */
                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);
-                       run_nfsd4_cb(&dp->dl_recall);
-                       return;
-               }
        }
        if (dp->dl_retries--) {
                rpc_delay(task, 2*HZ);