[PATCH net 0/4] s390/qeth: fixes 2018-03-20

[PATCH net 0/4] s390/qeth: fixes 2018-03-20

[Julian Wiedmann]

Hi Dave,

Please apply one final set of qeth patches for 4.16.
All of these fix long-standing bugs, so please queue them up for -stable
as well.

Thank you,
Julian


Julian Wiedmann (4):
  s390/qeth: free netdevice when removing a card
  s390/qeth: when thread completes, wake up all waiters
  s390/qeth: lock read device while queueing next buffer
  s390/qeth: on channel error, reject further cmd requests

 drivers/s390/net/qeth_core_main.c | 21 +++++++++++++++------
 drivers/s390/net/qeth_l2_main.c   |  2 +-
 drivers/s390/net/qeth_l3_main.c   |  2 +-
 3 files changed, 17 insertions(+), 8 deletions(-)

-- 
2.13.5

[PATCH net 0/4] s390/qeth: fixes 2018-03-20

[Julian Wiedmann]

Hi Dave,

Please apply one final set of qeth patches for 4.16.
All of these fix long-standing bugs, so please queue them up for -stable
as well.

Thank you,
Julian


Julian Wiedmann (4):
  s390/qeth: free netdevice when removing a card
  s390/qeth: when thread completes, wake up all waiters
  s390/qeth: lock read device while queueing next buffer
  s390/qeth: on channel error, reject further cmd requests

 drivers/s390/net/qeth_core_main.c | 21 +++++++++++++++------
 drivers/s390/net/qeth_l2_main.c   |  2 +-
 drivers/s390/net/qeth_l3_main.c   |  2 +-
 3 files changed, 17 insertions(+), 8 deletions(-)

-- 
2.13.5

[PATCH net 1/4] s390/qeth: free netdevice when removing a card

[Julian Wiedmann]

On removal, a qeth card's netdevice is currently not properly freed
because the call chain looks as follows:

qeth_core_remove_device(card)
	lx_remove_device(card)
		unregister_netdev(card->dev)
		card->dev = NULL			!!!
	qeth_core_free_card(card)
		if (card->dev)				!!!
			free_netdev(card->dev)

Fix it by free'ing the netdev straight after unregistering. This also
fixes the sysfs-driven layer switch case (qeth_dev_layer2_store()),
where the need to free the current netdevice was not considered at all.

Note that free_netdev() takes care of the netif_napi_del() for us too.

Fixes: 4a71df50047f ("qeth: new qeth device driver")
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
---
 drivers/s390/net/qeth_core_main.c | 2 --
 drivers/s390/net/qeth_l2_main.c   | 2 +-
 drivers/s390/net/qeth_l3_main.c   | 2 +-
 3 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index c8b308cfabf1..4a820afececd 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -5087,8 +5087,6 @@ static void qeth_core_free_card(struct qeth_card *card)
 	QETH_DBF_HEX(SETUP, 2, &card, sizeof(void *));
 	qeth_clean_channel(&card->read);
 	qeth_clean_channel(&card->write);
-	if (card->dev)
-		free_netdev(card->dev);
 	qeth_free_qdio_buffers(card);
 	unregister_service_level(&card->qeth_service_level);
 	kfree(card);
diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
index 7f236440483f..5ef4c978ad19 100644
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -915,8 +915,8 @@ static void qeth_l2_remove_device(struct ccwgroup_device *cgdev)
 		qeth_l2_set_offline(cgdev);
 
 	if (card->dev) {
-		netif_napi_del(&card->napi);
 		unregister_netdev(card->dev);
+		free_netdev(card->dev);
 		card->dev = NULL;
 	}
 	return;
diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index 962a04b68dd2..b6b12220da71 100644
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -2865,8 +2865,8 @@ static void qeth_l3_remove_device(struct ccwgroup_device *cgdev)
 		qeth_l3_set_offline(cgdev);
 
 	if (card->dev) {
-		netif_napi_del(&card->napi);
 		unregister_netdev(card->dev);
+		free_netdev(card->dev);
 		card->dev = NULL;
 	}
 
-- 
2.13.5

[PATCH net 1/4] s390/qeth: free netdevice when removing a card

[Julian Wiedmann]

On removal, a qeth card's netdevice is currently not properly freed
because the call chain looks as follows:

qeth_core_remove_device(card)
	lx_remove_device(card)
		unregister_netdev(card->dev)
		card->dev = NULL			!!!
	qeth_core_free_card(card)
		if (card->dev)				!!!
			free_netdev(card->dev)

Fix it by free'ing the netdev straight after unregistering. This also
fixes the sysfs-driven layer switch case (qeth_dev_layer2_store()),
where the need to free the current netdevice was not considered at all.

Note that free_netdev() takes care of the netif_napi_del() for us too.

Fixes: 4a71df50047f ("qeth: new qeth device driver")
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
---
 drivers/s390/net/qeth_core_main.c | 2 --
 drivers/s390/net/qeth_l2_main.c   | 2 +-
 drivers/s390/net/qeth_l3_main.c   | 2 +-
 3 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index c8b308cfabf1..4a820afececd 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -5087,8 +5087,6 @@ static void qeth_core_free_card(struct qeth_card *card)
 	QETH_DBF_HEX(SETUP, 2, &card, sizeof(void *));
 	qeth_clean_channel(&card->read);
 	qeth_clean_channel(&card->write);
-	if (card->dev)
-		free_netdev(card->dev);
 	qeth_free_qdio_buffers(card);
 	unregister_service_level(&card->qeth_service_level);
 	kfree(card);
diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
index 7f236440483f..5ef4c978ad19 100644
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -915,8 +915,8 @@ static void qeth_l2_remove_device(struct ccwgroup_device *cgdev)
 		qeth_l2_set_offline(cgdev);
 
 	if (card->dev) {
-		netif_napi_del(&card->napi);
 		unregister_netdev(card->dev);
+		free_netdev(card->dev);
 		card->dev = NULL;
 	}
 	return;
diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index 962a04b68dd2..b6b12220da71 100644
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -2865,8 +2865,8 @@ static void qeth_l3_remove_device(struct ccwgroup_device *cgdev)
 		qeth_l3_set_offline(cgdev);
 
 	if (card->dev) {
-		netif_napi_del(&card->napi);
 		unregister_netdev(card->dev);
+		free_netdev(card->dev);
 		card->dev = NULL;
 	}
 
-- 
2.13.5

[PATCH net 2/4] s390/qeth: when thread completes, wake up all waiters

[Julian Wiedmann]

qeth_wait_for_threads() is potentially called by multiple users, make
sure to notify all of them after qeth_clear_thread_running_bit()
adjusted the thread_running_mask. With no timeout, callers would
otherwise stall.

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
---
 drivers/s390/net/qeth_core_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 4a820afececd..42ee8806fa53 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -960,7 +960,7 @@ void qeth_clear_thread_running_bit(struct qeth_card *card, unsigned long thread)
 	spin_lock_irqsave(&card->thread_mask_lock, flags);
 	card->thread_running_mask &= ~thread;
 	spin_unlock_irqrestore(&card->thread_mask_lock, flags);
-	wake_up(&card->wait_q);
+	wake_up_all(&card->wait_q);
 }
 EXPORT_SYMBOL_GPL(qeth_clear_thread_running_bit);
 
-- 
2.13.5

[PATCH net 2/4] s390/qeth: when thread completes, wake up all waiters

[Julian Wiedmann]

qeth_wait_for_threads() is potentially called by multiple users, make
sure to notify all of them after qeth_clear_thread_running_bit()
adjusted the thread_running_mask. With no timeout, callers would
otherwise stall.

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
---
 drivers/s390/net/qeth_core_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 4a820afececd..42ee8806fa53 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -960,7 +960,7 @@ void qeth_clear_thread_running_bit(struct qeth_card *card, unsigned long thread)
 	spin_lock_irqsave(&card->thread_mask_lock, flags);
 	card->thread_running_mask &= ~thread;
 	spin_unlock_irqrestore(&card->thread_mask_lock, flags);
-	wake_up(&card->wait_q);
+	wake_up_all(&card->wait_q);
 }
 EXPORT_SYMBOL_GPL(qeth_clear_thread_running_bit);
 
-- 
2.13.5

[PATCH net 3/4] s390/qeth: lock read device while queueing next buffer

[Julian Wiedmann]

For calling ccw_device_start(), issue_next_read() needs to hold the
device's ccwlock.
This is satisfied for the IRQ handler path (where qeth_irq() gets called
under the ccwlock), but we need explicit locking for the initial call by
the MPC initialization.

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
---
 drivers/s390/net/qeth_core_main.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 42ee8806fa53..2a9afaf8f264 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -527,8 +527,7 @@ static inline int qeth_is_cq(struct qeth_card *card, unsigned int queue)
 	    queue == card->qdio.no_in_queues - 1;
 }
 
-
-static int qeth_issue_next_read(struct qeth_card *card)
+static int __qeth_issue_next_read(struct qeth_card *card)
 {
 	int rc;
 	struct qeth_cmd_buffer *iob;
@@ -559,6 +558,17 @@ static int qeth_issue_next_read(struct qeth_card *card)
 	return rc;
 }
 
+static int qeth_issue_next_read(struct qeth_card *card)
+{
+	int ret;
+
+	spin_lock_irq(get_ccwdev_lock(CARD_RDEV(card)));
+	ret = __qeth_issue_next_read(card);
+	spin_unlock_irq(get_ccwdev_lock(CARD_RDEV(card)));
+
+	return ret;
+}
+
 static struct qeth_reply *qeth_alloc_reply(struct qeth_card *card)
 {
 	struct qeth_reply *reply;
@@ -1182,7 +1192,7 @@ static void qeth_irq(struct ccw_device *cdev, unsigned long intparm,
 		return;
 	if (channel == &card->read &&
 	    channel->state == CH_STATE_UP)
-		qeth_issue_next_read(card);
+		__qeth_issue_next_read(card);
 
 	iob = channel->iob;
 	index = channel->buf_no;
-- 
2.13.5

[PATCH net 3/4] s390/qeth: lock read device while queueing next buffer

[Julian Wiedmann]

For calling ccw_device_start(), issue_next_read() needs to hold the
device's ccwlock.
This is satisfied for the IRQ handler path (where qeth_irq() gets called
under the ccwlock), but we need explicit locking for the initial call by
the MPC initialization.

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
---
 drivers/s390/net/qeth_core_main.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 42ee8806fa53..2a9afaf8f264 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -527,8 +527,7 @@ static inline int qeth_is_cq(struct qeth_card *card, unsigned int queue)
 	    queue == card->qdio.no_in_queues - 1;
 }
 
-
-static int qeth_issue_next_read(struct qeth_card *card)
+static int __qeth_issue_next_read(struct qeth_card *card)
 {
 	int rc;
 	struct qeth_cmd_buffer *iob;
@@ -559,6 +558,17 @@ static int qeth_issue_next_read(struct qeth_card *card)
 	return rc;
 }
 
+static int qeth_issue_next_read(struct qeth_card *card)
+{
+	int ret;
+
+	spin_lock_irq(get_ccwdev_lock(CARD_RDEV(card)));
+	ret = __qeth_issue_next_read(card);
+	spin_unlock_irq(get_ccwdev_lock(CARD_RDEV(card)));
+
+	return ret;
+}
+
 static struct qeth_reply *qeth_alloc_reply(struct qeth_card *card)
 {
 	struct qeth_reply *reply;
@@ -1182,7 +1192,7 @@ static void qeth_irq(struct ccw_device *cdev, unsigned long intparm,
 		return;
 	if (channel == &card->read &&
 	    channel->state == CH_STATE_UP)
-		qeth_issue_next_read(card);
+		__qeth_issue_next_read(card);
 
 	iob = channel->iob;
 	index = channel->buf_no;
-- 
2.13.5

[PATCH net 4/4] s390/qeth: on channel error, reject further cmd requests

[Julian Wiedmann]

When the IRQ handler determines that one of the cmd IO channels has
failed and schedules recovery, block any further cmd requests from
being submitted. The request would inevitably stall, and prevent the
recovery from making progress until the request times out.

This sort of error was observed after Live Guest Relocation, where
the pending IO on the READ channel intentionally gets terminated to
kick-start recovery. Simultaneously the guest executed SIOCETHTOOL,
triggering qeth to issue a QUERY CARD INFO command. The command
then stalled in the inoperabel WRITE channel.

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
---
 drivers/s390/net/qeth_core_main.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 2a9afaf8f264..3653bea38470 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -1174,6 +1174,7 @@ static void qeth_irq(struct ccw_device *cdev, unsigned long intparm,
 		}
 		rc = qeth_get_problem(cdev, irb);
 		if (rc) {
+			card->read_or_write_problem = 1;
 			qeth_clear_ipacmd_list(card);
 			qeth_schedule_recovery(card);
 			goto out;
-- 
2.13.5

[PATCH net 4/4] s390/qeth: on channel error, reject further cmd requests

[Julian Wiedmann]

When the IRQ handler determines that one of the cmd IO channels has
failed and schedules recovery, block any further cmd requests from
being submitted. The request would inevitably stall, and prevent the
recovery from making progress until the request times out.

This sort of error was observed after Live Guest Relocation, where
the pending IO on the READ channel intentionally gets terminated to
kick-start recovery. Simultaneously the guest executed SIOCETHTOOL,
triggering qeth to issue a QUERY CARD INFO command. The command
then stalled in the inoperabel WRITE channel.

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
---
 drivers/s390/net/qeth_core_main.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 2a9afaf8f264..3653bea38470 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -1174,6 +1174,7 @@ static void qeth_irq(struct ccw_device *cdev, unsigned long intparm,
 		}
 		rc = qeth_get_problem(cdev, irb);
 		if (rc) {
+			card->read_or_write_problem = 1;
 			qeth_clear_ipacmd_list(card);
 			qeth_schedule_recovery(card);
 			goto out;
-- 
2.13.5

Re: [PATCH net 0/4] s390/qeth: fixes 2018-03-20

[David Miller]

From: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Date: Tue, 20 Mar 2018 07:59:11 +0100

> Please apply one final set of qeth patches for 4.16.
> All of these fix long-standing bugs, so please queue them up for -stable
> as well.

Series applied and queued up for -stable, thank you.