[PATCH net-next 0/7] net/smc: patches 2019-02-12

[PATCH net-next 0/7] net/smc: patches 2019-02-12

[Ursula Braun]

Dave,

here are patches for SMC:
* patches 1 and 3 optimize SMC-R tx logic
* patch 2 is a cleanup without functional change
* patch 4 optimizes rx logic
* patches 5 and 6 improve robustness in link group and IB event handling
* patch 7 establishes Karsten Graul as another SMC maintainer

Thanks, Ursula

Karsten Graul (6):
  net/smc: reset cursor update required flag
  net/smc: move wake up of close waiters to main send function
  net/smc: no delay when waiting for free transfer buffers
  net/smc: reduce amount of status updates to peer
  net/smc: always check for connections in smc_lgr_free_work()
  net/smc: check port_idx of ib event, update handled events

Ursula Braun (1):
  MAINTAINERS: add Karsten as SMC maintainer

 MAINTAINERS        |  1 +
 net/smc/smc_cdc.c  | 29 ++++++++++++-----------------
 net/smc/smc_core.c |  6 ++----
 net/smc/smc_ib.c   | 24 ++++++++++++++++--------
 net/smc/smc_tx.c   | 12 ++++++++----
 5 files changed, 39 insertions(+), 33 deletions(-)

-- 
2.16.4

[PATCH net-next 1/7] net/smc: reset cursor update required flag

[Ursula Braun]

From: Karsten Graul <kgraul@linux.ibm.com>

When an updated rx_cursor_confirmed field was sent to the peer then
reset the cons_curs_upd_req flag. And remove the duplicate reset and
cursor update in smc_tx_consumer_update().

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
---
 net/smc/smc_cdc.c | 5 ++++-
 net/smc/smc_tx.c  | 3 ---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/net/smc/smc_cdc.c b/net/smc/smc_cdc.c
index a712c9f8699b..99d9d6e85dfb 100644
--- a/net/smc/smc_cdc.c
+++ b/net/smc/smc_cdc.c
@@ -105,8 +105,10 @@ int smc_cdc_msg_send(struct smc_connection *conn,
 			    &conn->local_tx_ctrl, conn);
 	smc_curs_copy(&cfed, &((struct smc_host_cdc_msg *)wr_buf)->cons, conn);
 	rc = smc_wr_tx_send(link, (struct smc_wr_tx_pend_priv *)pend);
-	if (!rc)
+	if (!rc) {
 		smc_curs_copy(&conn->rx_curs_confirmed, &cfed, conn);
+		conn->local_rx_ctrl.prod_flags.cons_curs_upd_req = 0;
+	}
 
 	return rc;
 }
@@ -194,6 +196,7 @@ int smcd_cdc_msg_send(struct smc_connection *conn)
 	if (rc)
 		return rc;
 	smc_curs_copy(&conn->rx_curs_confirmed, &curs, conn);
+	conn->local_rx_ctrl.prod_flags.cons_curs_upd_req = 0;
 	/* Calculate transmitted data and increment free send buffer space */
 	diff = smc_curs_diff(conn->sndbuf_desc->len, &conn->tx_curs_fin,
 			     &conn->tx_curs_sent);
diff --git a/net/smc/smc_tx.c b/net/smc/smc_tx.c
index f93f3580c100..ce9586bce364 100644
--- a/net/smc/smc_tx.c
+++ b/net/smc/smc_tx.c
@@ -610,9 +610,6 @@ void smc_tx_consumer_update(struct smc_connection *conn, bool force)
 					      SMC_TX_WORK_DELAY);
 			return;
 		}
-		smc_curs_copy(&conn->rx_curs_confirmed,
-			      &conn->local_tx_ctrl.cons, conn);
-		conn->local_rx_ctrl.prod_flags.cons_curs_upd_req = 0;
 	}
 	if (conn->local_rx_ctrl.prod_flags.write_blocked &&
 	    !atomic_read(&conn->bytes_to_rcv))
-- 
2.16.4

[PATCH net-next 2/7] net/smc: move wake up of close waiter

[Ursula Braun]

From: Karsten Graul <kgraul@linux.ibm.com>

Move the call to smc_close_wake_tx_prepared() (which wakes up a possibly
waiting close processing that might wait for 'all data sent') to
smc_tx_sndbuf_nonempty() (which is the main function to send data).

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
---
 net/smc/smc_cdc.c | 2 --
 net/smc/smc_tx.c  | 7 +++++++
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/net/smc/smc_cdc.c b/net/smc/smc_cdc.c
index 99d9d6e85dfb..780b36c69292 100644
--- a/net/smc/smc_cdc.c
+++ b/net/smc/smc_cdc.c
@@ -290,8 +290,6 @@ static void smc_cdc_msg_recv_action(struct smc_sock *smc,
 	/* trigger sndbuf consumer: RDMA write into peer RMBE and CDC */
 	if (diff_cons && smc_tx_prepared_sends(conn)) {
 		smc_tx_sndbuf_nonempty(conn);
-		/* trigger socket release if connection closed */
-		smc_close_wake_tx_prepared(smc);
 	}
 	if (diff_cons && conn->urg_tx_pend &&
 	    atomic_read(&conn->peer_rmbe_space) == conn->peer_rmbe_size) {
diff --git a/net/smc/smc_tx.c b/net/smc/smc_tx.c
index ce9586bce364..dd10a913b38e 100644
--- a/net/smc/smc_tx.c
+++ b/net/smc/smc_tx.c
@@ -24,6 +24,7 @@
 #include "smc.h"
 #include "smc_wr.h"
 #include "smc_cdc.h"
+#include "smc_close.h"
 #include "smc_ism.h"
 #include "smc_tx.h"
 
@@ -554,6 +555,12 @@ int smc_tx_sndbuf_nonempty(struct smc_connection *conn)
 	else
 		rc = smcr_tx_sndbuf_nonempty(conn);
 
+	if (!rc) {
+		/* trigger socket release if connection is closing */
+		struct smc_sock *smc = container_of(conn, struct smc_sock,
+						    conn);
+		smc_close_wake_tx_prepared(smc);
+	}
 	return rc;
 }
 
-- 
2.16.4

[PATCH net-next 3/7] net/smc: no delay for free tx buffer wait

[Ursula Braun]

From: Karsten Graul <kgraul@linux.ibm.com>

When no free transfer buffers are available then a work to call
smc_tx_work() is scheduled. Set the schedule delay to zero, because for
the out-of-buffers condition the work can start immediately and will
block in the called function smc_wr_tx_get_free_slot(), waiting for free
buffers.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
---
 net/smc/smc_tx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/smc/smc_tx.c b/net/smc/smc_tx.c
index dd10a913b38e..a3bff08ff8c8 100644
--- a/net/smc/smc_tx.c
+++ b/net/smc/smc_tx.c
@@ -28,7 +28,7 @@
 #include "smc_ism.h"
 #include "smc_tx.h"
 
-#define SMC_TX_WORK_DELAY	HZ
+#define SMC_TX_WORK_DELAY	0
 #define SMC_TX_CORK_DELAY	(HZ >> 2)	/* 250 ms */
 
 /***************************** sndbuf producer *******************************/
-- 
2.16.4

[PATCH net-next 4/7] net/smc: reduce amount of status updates to peer

[Ursula Braun]

From: Karsten Graul <kgraul@linux.ibm.com>

In smc_cdc_msg_recv_action() the received cdc message is evaluated.
To reduce the number of messaged triggered by this evaluation the logic
is streamlined. For the write_blocked condition we do not need to send
a response immediately. The remaining conditions can be put together
into one if clause.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
---
 net/smc/smc_cdc.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/net/smc/smc_cdc.c b/net/smc/smc_cdc.c
index 780b36c69292..28bbdb04bc35 100644
--- a/net/smc/smc_cdc.c
+++ b/net/smc/smc_cdc.c
@@ -273,24 +273,18 @@ static void smc_cdc_msg_recv_action(struct smc_sock *smc,
 		smp_mb__after_atomic();
 		smc->sk.sk_data_ready(&smc->sk);
 	} else {
-		if (conn->local_rx_ctrl.prod_flags.write_blocked ||
-		    conn->local_rx_ctrl.prod_flags.cons_curs_upd_req ||
-		    conn->local_rx_ctrl.prod_flags.urg_data_pending) {
-			if (conn->local_rx_ctrl.prod_flags.urg_data_pending)
-				conn->urg_state = SMC_URG_NOTYET;
-			/* force immediate tx of current consumer cursor, but
-			 * under send_lock to guarantee arrival in seqno-order
-			 */
-			if (smc->sk.sk_state != SMC_INIT)
-				smc_tx_sndbuf_nonempty(conn);
-		}
+		if (conn->local_rx_ctrl.prod_flags.write_blocked)
+			smc->sk.sk_data_ready(&smc->sk);
+		if (conn->local_rx_ctrl.prod_flags.urg_data_pending)
+			conn->urg_state = SMC_URG_NOTYET;
 	}
 
-	/* piggy backed tx info */
 	/* trigger sndbuf consumer: RDMA write into peer RMBE and CDC */
-	if (diff_cons && smc_tx_prepared_sends(conn)) {
+	if ((diff_cons && smc_tx_prepared_sends(conn)) ||
+	    conn->local_rx_ctrl.prod_flags.cons_curs_upd_req ||
+	    conn->local_rx_ctrl.prod_flags.urg_data_pending)
 		smc_tx_sndbuf_nonempty(conn);
-	}
+
 	if (diff_cons && conn->urg_tx_pend &&
 	    atomic_read(&conn->peer_rmbe_space) == conn->peer_rmbe_size) {
 		/* urg data confirmed by peer, indicate we're ready for more */
-- 
2.16.4

[PATCH net-next 5/7] net/smc: check connections in smc_lgr_free_work

[Ursula Braun]

From: Karsten Graul <kgraul@linux.ibm.com>

Remove the shortcut that smc_lgr_free() would skip the check for
existing connections when the link group is not in the link group list.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
---
 net/smc/smc_core.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 349d789a9728..53a17cfa61af 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -160,8 +160,6 @@ static void smc_lgr_free_work(struct work_struct *work)
 	bool conns;
 
 	spin_lock_bh(&smc_lgr_list.lock);
-	if (list_empty(&lgr->list))
-		goto free;
 	read_lock_bh(&lgr->conns_lock);
 	conns = RB_EMPTY_ROOT(&lgr->conns_all);
 	read_unlock_bh(&lgr->conns_lock);
@@ -169,8 +167,8 @@ static void smc_lgr_free_work(struct work_struct *work)
 		spin_unlock_bh(&smc_lgr_list.lock);
 		return;
 	}
-	list_del_init(&lgr->list); /* remove from smc_lgr_list */
-free:
+	if (!list_empty(&lgr->list))
+		list_del_init(&lgr->list); /* remove from smc_lgr_list */
 	spin_unlock_bh(&smc_lgr_list.lock);
 
 	if (!lgr->is_smcd && !lgr->terminating)	{
-- 
2.16.4

[PATCH net-next 6/7] net/smc: check port_idx of ib event

[Ursula Braun]

From: Karsten Graul <kgraul@linux.ibm.com>

For robustness protect of higher port numbers than expected to avoid
setting bits behind our port_event_mask. In case of an DEVICE_FATAL
event all ports must be checked. The IB_EVENT_GID_CHANGE event is
provided in the global event handler, so handle it there. And handle a
QP_FATAL event instead of an DEVICE_FATAL event in the qp handler.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
---
 net/smc/smc_ib.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c
index 76487a16934e..0b244be24fe0 100644
--- a/net/smc/smc_ib.c
+++ b/net/smc/smc_ib.c
@@ -257,12 +257,20 @@ static void smc_ib_global_event_handler(struct ib_event_handler *handler,
 	smcibdev = container_of(handler, struct smc_ib_device, event_handler);
 
 	switch (ibevent->event) {
-	case IB_EVENT_PORT_ERR:
 	case IB_EVENT_DEVICE_FATAL:
+		/* terminate all ports on device */
+		for (port_idx = 0; port_idx < SMC_MAX_PORTS; port_idx++)
+			set_bit(port_idx, &smcibdev->port_event_mask);
+		schedule_work(&smcibdev->port_event_work);
+		break;
+	case IB_EVENT_PORT_ERR:
 	case IB_EVENT_PORT_ACTIVE:
+	case IB_EVENT_GID_CHANGE:
 		port_idx = ibevent->element.port_num - 1;
-		set_bit(port_idx, &smcibdev->port_event_mask);
-		schedule_work(&smcibdev->port_event_work);
+		if (port_idx < SMC_MAX_PORTS) {
+			set_bit(port_idx, &smcibdev->port_event_mask);
+			schedule_work(&smcibdev->port_event_work);
+		}
 		break;
 	default:
 		break;
@@ -294,13 +302,13 @@ static void smc_ib_qp_event_handler(struct ib_event *ibevent, void *priv)
 	u8 port_idx;
 
 	switch (ibevent->event) {
-	case IB_EVENT_DEVICE_FATAL:
-	case IB_EVENT_GID_CHANGE:
-	case IB_EVENT_PORT_ERR:
+	case IB_EVENT_QP_FATAL:
 	case IB_EVENT_QP_ACCESS_ERR:
 		port_idx = ibevent->element.qp->port - 1;
-		set_bit(port_idx, &smcibdev->port_event_mask);
-		schedule_work(&smcibdev->port_event_work);
+		if (port_idx < SMC_MAX_PORTS) {
+			set_bit(port_idx, &smcibdev->port_event_mask);
+			schedule_work(&smcibdev->port_event_work);
+		}
 		break;
 	default:
 		break;
-- 
2.16.4

[PATCH net-next 7/7] MAINTAINERS: add Karsten as SMC maintainer

[Ursula Braun]

Add Karsten as additional maintainer for Shared Memory Communications
(SMC) Sockets.

Acked-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
---
 MAINTAINERS | 1 +
 1 file changed, 1 insertion(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 604bca2fc05d..f3af5cde6456 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13760,6 +13760,7 @@ F:	drivers/misc/sgi-xp/
 
 SHARED MEMORY COMMUNICATIONS (SMC) SOCKETS
 M:	Ursula Braun <ubraun@linux.ibm.com>
+M:	Karsten Graul <kgraul@linux.ibm.com>
 L:	linux-s390@vger.kernel.org
 W:	http://www.ibm.com/developerworks/linux/linux390/
 S:	Supported
-- 
2.16.4

Re: [PATCH net-next 0/7] net/smc: patches 2019-02-12

[David Miller]

From: Ursula Braun <ubraun@linux.ibm.com>
Date: Tue, 12 Feb 2019 16:29:49 +0100

> here are patches for SMC:
> * patches 1 and 3 optimize SMC-R tx logic
> * patch 2 is a cleanup without functional change
> * patch 4 optimizes rx logic
> * patches 5 and 6 improve robustness in link group and IB event handling
> * patch 7 establishes Karsten Graul as another SMC maintainer

Series applied, thanks.