From: Stephen Hemminger <stephen@networkplumber.org>
Date: Tue, 12 Dec 2017 16:48:39 -0800
Patch-mainline: v4.16-rc1
Subject: hv_netvsc: remove open_cnt reference count
Git-commit: 0da6edbd3a379433814c738e932474057537107c
References: fate#323887

There is only ever a single instance of network device object
referencing the internal rndis object. Therefore the open_cnt atomic
is not necessary.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Olaf Hering <ohering@suse.de>
---
 drivers/net/hyperv/hyperv_net.h   |  2 --
 drivers/net/hyperv/netvsc.c       |  2 +-
 drivers/net/hyperv/rndis_filter.c | 10 +++-------
 3 files changed, 4 insertions(+), 10 deletions(-)

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -823,8 +823,6 @@ struct netvsc_device {
 	u32 max_pkt; /* max number of pkt in one send, e.g. 8 */
 	u32 pkt_align; /* alignment bytes, e.g. 8 */
 
-	atomic_t open_cnt;
-
 	struct netvsc_channel chan_table[VRSS_CHANNEL_MAX];
 
 	struct rcu_head rcu;
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -73,7 +73,7 @@ static struct netvsc_device *alloc_net_device(void)
 
 	init_waitqueue_head(&net_device->wait_drain);
 	net_device->destroy = false;
-	atomic_set(&net_device->open_cnt, 0);
+
 	net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT;
 	net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT;
 
diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -1362,9 +1362,6 @@ int rndis_filter_open(struct netvsc_device *nvdev)
 	if (!nvdev)
 		return -EINVAL;
 
-	if (atomic_inc_return(&nvdev->open_cnt) != 1)
-		return 0;
-
 	return rndis_filter_open_device(nvdev->extension);
 }
 
@@ -1373,13 +1370,12 @@ int rndis_filter_close(struct netvsc_device *nvdev)
 	if (!nvdev)
 		return -EINVAL;
 
-	if (atomic_dec_return(&nvdev->open_cnt) != 0)
-		return 0;
-
 	return rndis_filter_close_device(nvdev->extension);
 }
 
 bool rndis_filter_opened(const struct netvsc_device *nvdev)
 {
-	return atomic_read(&nvdev->open_cnt) > 0;
+	const struct rndis_device *dev = nvdev->extension;
+
+	return dev->state == RNDIS_DEV_DATAINITIALIZED;
 }