nfsd: Fix slot wake up race in the nfsv4.1 callback code

[platform/adaptation/renesas_rcar/renesas_kernel.git] / fs / nfsd / nfs4callback.c

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 7f05cd1..f42bbe5 100644 (file)
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -637,9 +637,11 @@ static struct rpc_cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc
 
 static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
 {
+       int maxtime = max_cb_time(clp->net);
        struct rpc_timeout      timeparms = {
-               .to_initval     = max_cb_time(clp->net),
+               .to_initval     = maxtime,
                .to_retries     = 0,
+               .to_maxval      = maxtime,
        };
        struct rpc_create_args args = {
                .net            = clp->net,
@@ -670,7 +672,8 @@ static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *c
                clp->cl_cb_session = ses;
                args.bc_xprt = conn->cb_xprt;
                args.prognumber = clp->cl_cb_session->se_cb_prog;
-               args.protocol = XPRT_TRANSPORT_BC_TCP;
+               args.protocol = conn->cb_xprt->xpt_class->xcl_ident |
+                               XPRT_TRANSPORT_BC;
                args.authflavor = ses->se_cb_sec.flavor;
        }
        /* Create RPC client */
@@ -781,8 +784,12 @@ static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task)
 {
        if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
                rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
-               dprintk("%s slot is busy\n", __func__);
-               return false;
+               /* Race breaker */
+               if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
+                       dprintk("%s slot is busy\n", __func__);
+                       return false;
+               }
+               rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
        }
        return true;
 }