net/smc: immediate termination for SMCD link groups

SMCD link group termination is called when peer signals its shutdown
of its corresponding link group. For regular shutdowns no connections
exist anymore. For abnormal shutdowns connections must be killed and
their DMBs must be unregistered immediately. That means the SMCR method
to delay the link group freeing several seconds does not fit.

This patch adds immediate termination of a link group and its SMCD
connections and makes sure all SMCD link group related cleanup steps
are finished.

Signed-off-by: Ursula Braun <[e-mail]>
Signed-off-by: Karsten Graul <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/s390/net/ism.h

···
 #define ISM_UNREG_SBA	0x11
 #define ISM_UNREG_IEQ	0x12
 
-#define ISM_ERROR	0xFFFF
-
 struct ism_req_hdr {
 	u32 cmd;
 	u16 : 16;

include/net/smc.h

···
 #define ISM_EVENT_GID	1
 #define ISM_EVENT_SWR	2
 
+#define ISM_ERROR	0xFFFF
+
 struct smcd_event {
 	u32 type;
 	u32 code;

net/smc/smc_close.c

···
 	return smc_cdc_get_slot_and_msg_send(conn);
 }
 
+static void smc_close_cancel_work(struct smc_sock *smc)
+{
+	struct sock *sk = &smc->sk;
+
+	release_sock(sk);
+	cancel_work_sync(&smc->conn.close_work);
+	cancel_delayed_work_sync(&smc->conn.tx_work);
+	lock_sock(sk);
+	sk->sk_state = SMC_CLOSED;
+}
+
 /* terminate smc socket abnormally - active abort
  * link group is terminated, i.e. RDMA communication no longer possible
  */
···
 	switch (sk->sk_state) {
 	case SMC_ACTIVE:
 		sk->sk_state = SMC_PEERABORTWAIT;
-		release_sock(sk);
-		cancel_delayed_work_sync(&smc->conn.tx_work);
-		lock_sock(sk);
+		smc_close_cancel_work(smc);
 		sk->sk_state = SMC_CLOSED;
 		sock_put(sk); /* passive closing */
 		break;
 	case SMC_APPCLOSEWAIT1:
 	case SMC_APPCLOSEWAIT2:
-		release_sock(sk);
-		cancel_delayed_work_sync(&smc->conn.tx_work);
-		lock_sock(sk);
+		smc_close_cancel_work(smc);
 		sk->sk_state = SMC_CLOSED;
 		sock_put(sk); /* postponed passive closing */
 		break;
 	case SMC_PEERCLOSEWAIT1:
 	case SMC_PEERCLOSEWAIT2:
 	case SMC_PEERFINCLOSEWAIT:
+		sk->sk_state = SMC_PEERABORTWAIT;
+		smc_close_cancel_work(smc);
 		sk->sk_state = SMC_CLOSED;
 		smc_conn_free(&smc->conn);
 		release_clcsock = true;
···
 		break;
 	case SMC_PROCESSABORT:
 	case SMC_APPFINCLOSEWAIT:
+		sk->sk_state = SMC_PEERABORTWAIT;
+		smc_close_cancel_work(smc);
 		sk->sk_state = SMC_CLOSED;
+		smc_conn_free(&smc->conn);
+		release_clcsock = true;
 		break;
 	case SMC_INIT:
 	case SMC_PEERABORTWAIT:

net/smc/smc_core.c

···
 
 	if (!lgr->is_smcd && lnk->state != SMC_LNK_INACTIVE)
 		smc_llc_link_inactive(lnk);
-	if (lgr->is_smcd)
+	if (lgr->is_smcd && !lgr->terminating)
 		smc_ism_signal_shutdown(lgr);
 	smc_lgr_free(lgr);
 }
···
 	if (!lgr)
 		return;
 	if (lgr->is_smcd) {
-		smc_ism_unset_conn(conn);
+		if (!list_empty(&lgr->list))
+			smc_ism_unset_conn(conn);
 		tasklet_kill(&conn->rx_tsklet);
 	} else {
 		smc_cdc_tx_dismiss_slots(conn);
···
 {
 	smc_lgr_free_bufs(lgr);
 	if (lgr->is_smcd) {
-		smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
-		put_device(&lgr->smcd->dev);
+		if (!lgr->terminating) {
+			smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
+			put_device(&lgr->smcd->dev);
+		}
 	} else {
 		smc_link_clear(&lgr->lnk[SMC_SINGLE_LINK]);
 		put_device(&lgr->lnk[SMC_SINGLE_LINK].smcibdev->ibdev->dev);
···
 	if (!list_empty(lgr_list))
 		list_del_init(lgr_list);
 	spin_unlock_bh(lgr_lock);
+}
+
+static void smcd_unregister_all_dmbs(struct smc_link_group *lgr)
+{
+	int i;
+
+	for (i = 0; i < SMC_RMBE_SIZES; i++) {
+		struct smc_buf_desc *buf_desc;
+
+		list_for_each_entry(buf_desc, &lgr->rmbs[i], list) {
+			buf_desc->len += sizeof(struct smcd_cdc_msg);
+			smc_ism_unregister_dmb(lgr->smcd, buf_desc);
+		}
+	}
 }
 
 static void smc_sk_wake_ups(struct smc_sock *smc)
···
 	conn->killed = 1;
 	smc->sk.sk_err = ECONNABORTED;
 	smc_sk_wake_ups(smc);
-	if (conn->lgr->is_smcd)
+	if (conn->lgr->is_smcd) {
+		smc_ism_unset_conn(conn);
 		tasklet_kill(&conn->rx_tsklet);
+	}
 	smc_lgr_unregister_conn(conn);
 	smc_close_active_abort(smc);
+}
+
+static void smc_lgr_cleanup(struct smc_link_group *lgr)
+{
+	if (lgr->is_smcd) {
+		smc_ism_signal_shutdown(lgr);
+		smcd_unregister_all_dmbs(lgr);
+		smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
+		put_device(&lgr->smcd->dev);
+	} else {
+		struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
+
+		wake_up(&lnk->wr_reg_wait);
+	}
 }
 
 /* terminate link group */
···
 		node = rb_first(&lgr->conns_all);
 	}
 	read_unlock_bh(&lgr->conns_lock);
-	if (!lgr->is_smcd)
-		wake_up(&lgr->lnk[SMC_SINGLE_LINK].wr_reg_wait);
+	smc_lgr_cleanup(lgr);
 	smc_lgr_schedule_free_work_fast(lgr);
 }
 

net/smc/smc_ism.c

···
 int smc_ism_unregister_dmb(struct smcd_dev *smcd, struct smc_buf_desc *dmb_desc)
 {
 	struct smcd_dmb dmb;
+	int rc = 0;
+
+	if (!dmb_desc->dma_addr)
+		return rc;
 
 	memset(&dmb, 0, sizeof(dmb));
 	dmb.dmb_tok = dmb_desc->token;
···
 	dmb.cpu_addr = dmb_desc->cpu_addr;
 	dmb.dma_addr = dmb_desc->dma_addr;
 	dmb.dmb_len = dmb_desc->len;
-	return smcd->ops->unregister_dmb(smcd, &dmb);
+	rc = smcd->ops->unregister_dmb(smcd, &dmb);
+	if (!rc || rc == ISM_ERROR) {
+		dmb_desc->cpu_addr = NULL;
+		dmb_desc->dma_addr = 0;
+	}
+
+	return rc;
 }
 
 int smc_ism_register_dmb(struct smc_link_group *lgr, int dmb_len,
···
 
 	spin_lock_irqsave(&smcd->lock, flags);
 	conn = smcd->conn[dmbno];
-	if (conn)
+	if (conn && !conn->killed)
 		tasklet_schedule(&conn->rx_tsklet);
 	spin_unlock_irqrestore(&smcd->lock, flags);
 }