--- zzzz-none-000/linux-3.10.107/fs/nfs/callback.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/fs/nfs/callback.c	2021-02-04 17:41:59.000000000 +0000
@@ -99,17 +99,6 @@
 }
 
 #if defined(CONFIG_NFS_V4_1)
-static int nfs41_callback_up_net(struct svc_serv *serv, struct net *net)
-{
-	/*
-	 * Create an svc_sock for the back channel service that shares the
-	 * fore channel connection.
-	 * Returns the input port (0) and sets the svc_serv bc_xprt on success
-	 */
-	return svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0,
-			      SVC_SOCK_ANONYMOUS);
-}
-
 /*
  * The callback service for NFSv4.1 callbacks
  */
@@ -128,7 +117,7 @@
 		if (try_to_freeze())
 			continue;
 
-		prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_UNINTERRUPTIBLE);
+		prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
 		spin_lock_bh(&serv->sv_cb_lock);
 		if (!list_empty(&serv->sv_cb_list)) {
 			req = list_first_entry(&serv->sv_cb_list,
@@ -142,10 +131,10 @@
 				error);
 		} else {
 			spin_unlock_bh(&serv->sv_cb_lock);
-			/* schedule_timeout to game the hung task watchdog */
-			schedule_timeout(60 * HZ);
+			schedule();
 			finish_wait(&serv->sv_cb_waitq, &wq);
 		}
+		flush_signals(current);
 	}
 	return 0;
 }
@@ -162,12 +151,7 @@
 	spin_lock_init(&serv->sv_cb_lock);
 	init_waitqueue_head(&serv->sv_cb_waitq);
 	rqstp = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
-	if (IS_ERR(rqstp)) {
-		svc_xprt_put(serv->sv_bc_xprt);
-		serv->sv_bc_xprt = NULL;
-	}
-	dprintk("--> %s return %ld\n", __func__,
-		IS_ERR(rqstp) ? PTR_ERR(rqstp) : 0);
+	dprintk("--> %s return %d\n", __func__, PTR_ERR_OR_ZERO(rqstp));
 	return rqstp;
 }
 
@@ -189,11 +173,6 @@
 		xprt->bc_serv = serv;
 }
 #else
-static int nfs41_callback_up_net(struct svc_serv *serv, struct net *net)
-{
-	return 0;
-}
-
 static void nfs_minorversion_callback_svc_setup(struct svc_serv *serv,
 		struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
 {
@@ -213,7 +192,6 @@
 	struct svc_rqst *rqstp;
 	int (*callback_svc)(void *vrqstp);
 	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
-	char svc_name[12];
 	int ret;
 
 	nfs_callback_bc_serv(minorversion, xprt, serv);
@@ -237,10 +215,10 @@
 
 	svc_sock_update_bufs(serv);
 
-	sprintf(svc_name, "nfsv4.%u-svc", minorversion);
 	cb_info->serv = serv;
 	cb_info->rqst = rqstp;
-	cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
+	cb_info->task = kthread_create(callback_svc, cb_info->rqst,
+				    "nfsv4.%u-svc", minorversion);
 	if (IS_ERR(cb_info->task)) {
 		ret = PTR_ERR(cb_info->task);
 		svc_exit_thread(cb_info->rqst);
@@ -248,6 +226,8 @@
 		cb_info->task = NULL;
 		return ret;
 	}
+	rqstp->rq_task = cb_info->task;
+	wake_up_process(cb_info->task);
 	dprintk("nfs_callback_up: service started\n");
 	return 0;
 }
@@ -263,7 +243,8 @@
 	svc_shutdown_net(serv, net);
 }
 
-static int nfs_callback_up_net(int minorversion, struct svc_serv *serv, struct net *net)
+static int nfs_callback_up_net(int minorversion, struct svc_serv *serv,
+			       struct net *net, struct rpc_xprt *xprt)
 {
 	struct nfs_net *nn = net_generic(net, nfs_net_id);
 	int ret;
@@ -279,19 +260,11 @@
 		goto err_bind;
 	}
 
-	switch (minorversion) {
-		case 0:
-			ret = nfs4_callback_up_net(serv, net);
-			break;
-		case 1:
-			ret = nfs41_callback_up_net(serv, net);
-			break;
-		default:
-			printk(KERN_ERR "NFS: unknown callback version: %d\n",
-					minorversion);
-			ret = -EINVAL;
-			break;
-	}
+	ret = -EPROTONOSUPPORT;
+	if (!IS_ENABLED(CONFIG_NFS_V4_1) || minorversion == 0)
+		ret = nfs4_callback_up_net(serv, net);
+	else if (xprt->ops->bc_up)
+		ret = xprt->ops->bc_up(serv, net);
 
 	if (ret < 0) {
 		printk(KERN_ERR "NFS: callback service start failed\n");
@@ -308,6 +281,10 @@
 	return ret;
 }
 
+static struct svc_serv_ops nfs_cb_sv_ops = {
+	.svo_enqueue_xprt	= svc_xprt_do_enqueue,
+};
+
 static struct svc_serv *nfs_callback_create_svc(int minorversion)
 {
 	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
@@ -333,7 +310,7 @@
 		printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
 			cb_info->users);
 
-	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
+	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, &nfs_cb_sv_ops);
 	if (!serv) {
 		printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
 		return ERR_PTR(-ENOMEM);
@@ -364,7 +341,7 @@
 		goto err_create;
 	}
 
-	ret = nfs_callback_up_net(minorversion, serv, net);
+	ret = nfs_callback_up_net(minorversion, serv, net, xprt);
 	if (ret < 0)
 		goto err_net;
 
@@ -432,6 +409,18 @@
 	if (p == NULL)
 		return 0;
 
+	/*
+	 * Did we get the acceptor from userland during the SETCLIENID
+	 * negotiation?
+	 */
+	if (clp->cl_acceptor)
+		return !strcmp(p, clp->cl_acceptor);
+
+	/*
+	 * Otherwise try to verify it using the cl_hostname. Note that this
+	 * doesn't work if a non-canonical hostname was used in the devname.
+	 */
+
 	/* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
 
 	if (memcmp(p, "nfs@", 4) != 0)
@@ -446,7 +435,7 @@
  * pg_authenticate method for nfsv4 callback threads.
  *
  * The authflavor has been negotiated, so an incorrect flavor is a server
- * bug. Drop packets with incorrect authflavor.
+ * bug. Deny packets with incorrect authflavor.
  *
  * All other checking done after NFS decoding where the nfs_client can be
  * found in nfs4_callback_compound
@@ -456,12 +445,12 @@
 	switch (rqstp->rq_authop->flavour) {
 	case RPC_AUTH_NULL:
 		if (rqstp->rq_proc != CB_NULL)
-			return SVC_DROP;
+			return SVC_DENIED;
 		break;
 	case RPC_AUTH_GSS:
 		/* No RPC_AUTH_GSS support yet in NFSv4.1 */
 		 if (svc_is_backchannel(rqstp))
-			return SVC_DROP;
+			return SVC_DENIED;
 	}
 	return SVC_OK;
 }