[PATCH net-next 0/2] netvsc: fix module removal hangs

[PATCH net-next 0/2] netvsc: fix module removal hangs

[Stephen Hemminger]

A couple of patches are necessary to make netvsc driver module
removable again.

Stephen Hemminger (2):
  netvsc: need napi scheduled during removal
  netvsc: fix hang on netvsc module removal

 drivers/net/hyperv/netvsc.c | 20 ++++----------------
 1 file changed, 4 insertions(+), 16 deletions(-)

-- 
2.11.0

[PATCH net-next 1/2] netvsc: need napi scheduled during removal

[Stephen Hemminger]

Since rndis_halt_device waits until all outstanding sends and
receives are completed. Netvsc device needs to still schedule
NAPI to see those completions.

Fixes: 2506b1dc4bbe ("netvsc: implement NAPI")
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
---
 drivers/net/hyperv/netvsc.c | 16 ++--------------
 1 file changed, 2 insertions(+), 14 deletions(-)

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index b1328cef9d5a..0e0c757c1681 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -91,15 +91,6 @@ static void free_netvsc_device(struct netvsc_device *nvdev)
 }
 
 
-static inline bool netvsc_channel_idle(const struct netvsc_device *net_device,
-				       u16 q_idx)
-{
-	const struct netvsc_channel *nvchan = &net_device->chan_table[q_idx];
-
-	return atomic_read(&net_device->num_outstanding_recvs) == 0 &&
-		atomic_read(&nvchan->queue_sends) == 0;
-}
-
 static struct netvsc_device *get_outbound_net_device(struct hv_device *device)
 {
 	struct netvsc_device *net_device = hv_device_to_netvsc_device(device);
@@ -1273,13 +1264,10 @@ void netvsc_channel_cb(void *context)
 	if (unlikely(!ndev))
 		return;
 
-	net_device = net_device_to_netvsc_device(ndev);
-	if (unlikely(net_device->destroy) &&
-	    netvsc_channel_idle(net_device, q_idx))
-		return;
-
 	/* disable interupts from host */
 	hv_begin_read(&channel->inbound);
+
+	net_device = net_device_to_netvsc_device(ndev);
 	napi_schedule(&net_device->chan_table[q_idx].napi);
 }
 
-- 
2.11.0

[PATCH net-next 2/2] netvsc: fix hang on netvsc module removal

[Stephen Hemminger]

The code in netvsc_device_remove was incorrectly calling napi_disable
repeatedly on the same element. This would cause attempts
to remove netvsc module to hang.

Fixes: 2506b1dc4bbe ("netvsc: implement NAPI")
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
---
 drivers/net/hyperv/netvsc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 0e0c757c1681..8f9aeec2ce0f 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -562,8 +562,8 @@ void netvsc_device_remove(struct hv_device *device)
 	/* Now, we can close the channel safely */
 	vmbus_close(device->channel);
 
-	for (i = 0; i < VRSS_CHANNEL_MAX; i++)
-		napi_disable(&net_device->chan_table[0].napi);
+	for (i = 0; i < net_device->num_chn; i++)
+		napi_disable(&net_device->chan_table[i].napi);
 
 	/* Release all resources */
 	free_netvsc_device(net_device);
-- 
2.11.0

Re: [PATCH net-next 0/2] netvsc: fix module removal hangs

[David Miller]

From: Stephen Hemminger <stephen@networkplumber.org>
Date: Thu,  9 Mar 2017 15:04:13 -0800

> A couple of patches are necessary to make netvsc driver module
> removable again.

Series applied, thanks.