netdev - [PATCH net-next 1/8] net/smc: fix final cleanup sequence for SMCD devices

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Date:   Thu, 14 Nov 2019 13:02:40 +0100
From:   Karsten Graul <kgraul@...ux.ibm.com>
To:     davem@...emloft.net
Cc:     netdev@...r.kernel.org, linux-s390@...r.kernel.org,
        heiko.carstens@...ibm.com, raspl@...ux.ibm.com,
        ubraun@...ux.ibm.com
Subject: [PATCH net-next 1/8] net/smc: fix final cleanup sequence for SMCD devices

From: Ursula Braun <ubraun@...ux.ibm.com>

If peer announces shutdown, use the link group terminate worker for
local cleanup of link groups and connections to terminate link group
in proper context.

Make sure link groups are cleaned up first before destroying the
event queue of the SMCD device, because link group cleanup may
raise events.

Send signal shutdown only if peer has not done it already.

Send socket abort or close only, if peer has not already announced
shutdown.

Signed-off-by: Ursula Braun <ubraun@...ux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@...ux.ibm.com>
---
 net/smc/smc_cdc.c  |  3 +++
 net/smc/smc_core.c | 18 +++++++++++-------
 net/smc/smc_core.h |  2 ++
 net/smc/smc_ism.c  |  7 +++++--
 4 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/net/smc/smc_cdc.c b/net/smc/smc_cdc.c
index 7dc07ec2379b..164f1584861b 100644
--- a/net/smc/smc_cdc.c
+++ b/net/smc/smc_cdc.c
@@ -131,6 +131,9 @@ int smc_cdc_get_slot_and_msg_send(struct smc_connection *conn)
 {
 	int rc;
 
+	if (!conn->lgr || (conn->lgr->is_smcd && conn->lgr->peer_shutdown))
+		return -EPIPE;
+
 	if (conn->lgr->is_smcd) {
 		spin_lock_bh(&conn->send_lock);
 		rc = smcd_cdc_msg_send(conn);
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 0d92456729ab..561f069b30de 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -275,6 +275,7 @@ static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini)
 		lgr->smcd = ini->ism_dev;
 		lgr_list = &ini->ism_dev->lgr_list;
 		lgr_lock = &lgr->smcd->lgr_lock;
+		lgr->peer_shutdown = 0;
 	} else {
 		/* SMC-R specific settings */
 		get_device(&ini->ib_dev->ibdev->dev);
@@ -514,11 +515,16 @@ static void smc_conn_kill(struct smc_connection *conn)
 {
 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
 
-	smc_close_abort(conn);
+	if (conn->lgr->is_smcd && conn->lgr->peer_shutdown)
+		conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
+	else
+		smc_close_abort(conn);
 	conn->killed = 1;
+	smc->sk.sk_err = ECONNABORTED;
 	smc_sk_wake_ups(smc);
+	if (conn->lgr->is_smcd)
+		tasklet_kill(&conn->rx_tsklet);
 	smc_lgr_unregister_conn(conn);
-	smc->sk.sk_err = ECONNABORTED;
 	smc_close_active_abort(smc);
 }
 
@@ -604,6 +610,8 @@ void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid, unsigned short vlan)
 	list_for_each_entry_safe(lgr, l, &dev->lgr_list, list) {
 		if ((!peer_gid || lgr->peer_gid == peer_gid) &&
 		    (vlan == VLAN_VID_MASK || lgr->vlan_id == vlan)) {
+			if (peer_gid) /* peer triggered termination */
+				lgr->peer_shutdown = 1;
 			list_move(&lgr->list, &lgr_free_list);
 		}
 	}
@@ -612,11 +620,7 @@ void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid, unsigned short vlan)
 	/* cancel the regular free workers and actually free lgrs */
 	list_for_each_entry_safe(lgr, l, &lgr_free_list, list) {
 		list_del_init(&lgr->list);
-		__smc_lgr_terminate(lgr);
-		cancel_delayed_work_sync(&lgr->free_work);
-		if (!peer_gid && vlan == VLAN_VID_MASK) /* dev terminated? */
-			smc_ism_signal_shutdown(lgr);
-		smc_lgr_free(lgr);
+		schedule_work(&lgr->terminate_work);
 	}
 }
 
diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index e6fd1ed42064..097ceba86caf 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -228,6 +228,8 @@ struct smc_link_group {
 						/* Peer GID (remote) */
 			struct smcd_dev		*smcd;
 						/* ISM device for VLAN reg. */
+			u8			peer_shutdown : 1;
+						/* peer triggered shutdownn */
 		};
 	};
 };
diff --git a/net/smc/smc_ism.c b/net/smc/smc_ism.c
index ee7340898cb4..18946e95a3be 100644
--- a/net/smc/smc_ism.c
+++ b/net/smc/smc_ism.c
@@ -226,6 +226,9 @@ int smc_ism_signal_shutdown(struct smc_link_group *lgr)
 	int rc;
 	union smcd_sw_event_info ev_info;
 
+	if (lgr->peer_shutdown)
+		return 0;
+
 	memcpy(ev_info.uid, lgr->id, SMC_LGR_ID_SIZE);
 	ev_info.vlan_id = lgr->vlan_id;
 	ev_info.code = ISM_EVENT_REQUEST;
@@ -313,12 +316,12 @@ EXPORT_SYMBOL_GPL(smcd_register_dev);
 void smcd_unregister_dev(struct smcd_dev *smcd)
 {
 	spin_lock(&smcd_dev_list.lock);
-	list_del(&smcd->list);
+	list_del_init(&smcd->list);
 	spin_unlock(&smcd_dev_list.lock);
 	smcd->going_away = 1;
+	smc_smcd_terminate(smcd, 0, VLAN_VID_MASK);
 	flush_workqueue(smcd->event_wq);
 	destroy_workqueue(smcd->event_wq);
-	smc_smcd_terminate(smcd, 0, VLAN_VID_MASK);
 
 	device_del(&smcd->dev);
 }
-- 
2.17.1