From: Stefan Raspl <raspl@linux.ibm.com>
Subject: net/smc: prevent new connections on link group
Patch-mainline: v4.17-rc1
Git-commit: 9651b9346f5bc85a4fef96789c756748483d9ee2
References: FATE#325694, LTC#167874, bsc#1113480

Summary:     net/smc: SMC-R MVP
Description: Add latest upstream patches to push SMC-R to the MVP level

Upstream-Description:

             net/smc: prevent new connections on link group

             When the processing of a DELETE LINK message has started,
             new connections should not be added to the link group that
             is about to terminate.

             Signed-off-by: Karsten Graul <kgraul@linux.vnet.ibm.com>
             Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
             Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 net/smc/af_smc.c   |    9 ---------
 net/smc/smc_core.c |   19 ++++++++++---------
 net/smc/smc_core.h |    1 +
 net/smc/smc_llc.c  |    1 +
 4 files changed, 12 insertions(+), 18 deletions(-)

--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -356,15 +356,6 @@ static void smc_link_save_peer_info(stru
 	link->peer_mtu = clc->qp_mtu;
 }
 
-static void smc_lgr_forget(struct smc_link_group *lgr)
-{
-	spin_lock_bh(&smc_lgr_list.lock);
-	/* do not use this link group for new connections */
-	if (!list_empty(&lgr->list))
-		list_del_init(&lgr->list);
-	spin_unlock_bh(&smc_lgr_list.lock);
-}
-
 /* setup for RDMA connection of client */
 static int smc_connect_rdma(struct smc_sock *smc)
 {
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -308,6 +308,15 @@ void smc_lgr_free(struct smc_link_group
 	kfree(lgr);
 }
 
+void smc_lgr_forget(struct smc_link_group *lgr)
+{
+	spin_lock_bh(&smc_lgr_list.lock);
+	/* do not use this link group for new connections */
+	if (!list_empty(&lgr->list))
+		list_del_init(&lgr->list);
+	spin_unlock_bh(&smc_lgr_list.lock);
+}
+
 /* terminate linkgroup abnormally */
 void smc_lgr_terminate(struct smc_link_group *lgr)
 {
@@ -315,15 +324,7 @@ void smc_lgr_terminate(struct smc_link_g
 	struct smc_sock *smc;
 	struct rb_node *node;
 
-	spin_lock_bh(&smc_lgr_list.lock);
-	if (list_empty(&lgr->list)) {
-		/* termination already triggered */
-		spin_unlock_bh(&smc_lgr_list.lock);
-		return;
-	}
-	/* do not use this link group for new connections */
-	list_del_init(&lgr->list);
-	spin_unlock_bh(&smc_lgr_list.lock);
+	smc_lgr_forget(lgr);
 
 	write_lock_bh(&lgr->conns_lock);
 	node = rb_first(&lgr->conns_all);
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -196,6 +196,7 @@ struct smc_sock;
 struct smc_clc_msg_accept_confirm;
 
 void smc_lgr_free(struct smc_link_group *lgr);
+void smc_lgr_forget(struct smc_link_group *lgr);
 void smc_lgr_terminate(struct smc_link_group *lgr);
 int smc_buf_create(struct smc_sock *smc);
 int smc_rmb_rtoken_handling(struct smc_connection *conn,
--- a/net/smc/smc_llc.c
+++ b/net/smc/smc_llc.c
@@ -383,6 +383,7 @@ static void smc_llc_rx_delete_link(struc
 			smc_lgr_terminate(lgr);
 	} else {
 		if (lgr->role == SMC_SERV) {
+			smc_lgr_forget(lgr);
 			smc_llc_send_delete_link(link, SMC_LLC_REQ);
 		} else {
 			smc_llc_send_delete_link(link, SMC_LLC_RESP);