[PATCH net-next 0/3] net: make dev_close void

[PATCH net-next 0/3] net: make dev_close void

[Stephen Hemminger]

Noticed while working on other changes. Why is dev_close()
returning int, it should be void.  Should also change
ndo_close to be void, but that requires more work and someone
with more coccinelle foo (smpl) than me.

Stephen Hemminger (3):
  bluetooth: 6lowpan dev_close never returns error
  hns: remove useless void cast
  net: make dev_close and related functions void

 drivers/net/ethernet/hisilicon/hns/hns_ethtool.c |  2 +-
 include/linux/netdevice.h                        |  4 ++--
 net/bluetooth/6lowpan.c                          |  4 +---
 net/core/dev.c                                   | 26 ++++++++++--------------
 4 files changed, 15 insertions(+), 21 deletions(-)

-- 
2.11.0

[PATCH net-next 1/3] bluetooth: 6lowpan dev_close never returns error

[Stephen Hemminger]

The function dev_close in current kernel will never return an
error. Later changes will make it void.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
---
 net/bluetooth/6lowpan.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
index ab3b654b05cc..e542b8959d88 100644
--- a/net/bluetooth/6lowpan.c
+++ b/net/bluetooth/6lowpan.c
@@ -621,9 +621,7 @@ static void ifdown(struct net_device *netdev)
 	int err;
 
 	rtnl_lock();
-	err = dev_close(netdev);
-	if (err < 0)
-		BT_INFO("iface %s cannot be closed (%d)", netdev->name, err);
+	dev_close(netdev);
 	rtnl_unlock();
 }
 
-- 
2.11.0

[PATCH net-next 2/3] hns: remove useless void cast

[Stephen Hemminger]

There is no need to cast away return value of dev_close.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
---
 drivers/net/ethernet/hisilicon/hns/hns_ethtool.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c b/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c
index a8db27e86a11..78cb20c67aa6 100644
--- a/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c
+++ b/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c
@@ -595,7 +595,7 @@ static void hns_nic_self_test(struct net_device *ndev,
 		set_bit(NIC_STATE_TESTING, &priv->state);
 
 		if (if_running)
-			(void)dev_close(ndev);
+			dev_close(ndev);
 
 		for (i = 0; i < SELF_TEST_TPYE_NUM; i++) {
 			if (!st_param[i][1])
-- 
2.11.0

[PATCH net-next 3/3] net: make dev_close and related functions void

[Stephen Hemminger]

There is no useful return value from dev_close. All paths return 0.
Change dev_close and helper functions to void.

Signed-off-by: Stephen Hemminger <sthemmin-0li6OtcxBFHby3iVrkZq2A@public.gmane.org>
---
 include/linux/netdevice.h |  4 ++--
 net/core/dev.c            | 26 +++++++++++---------------
 2 files changed, 13 insertions(+), 17 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index c60351b84323..614642eb7eb7 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2432,8 +2432,8 @@ struct net_device *dev_get_by_name_rcu(struct net *net, const char *name);
 struct net_device *__dev_get_by_name(struct net *net, const char *name);
 int dev_alloc_name(struct net_device *dev, const char *name);
 int dev_open(struct net_device *dev);
-int dev_close(struct net_device *dev);
-int dev_close_many(struct list_head *head, bool unlink);
+void dev_close(struct net_device *dev);
+void dev_close_many(struct list_head *head, bool unlink);
 void dev_disable_lro(struct net_device *dev);
 int dev_loopback_xmit(struct net *net, struct sock *sk, struct sk_buff *newskb);
 int dev_queue_xmit(struct sk_buff *skb);
diff --git a/net/core/dev.c b/net/core/dev.c
index 467420eda02e..d1b9c9b6c970 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1413,7 +1413,7 @@ int dev_open(struct net_device *dev)
 }
 EXPORT_SYMBOL(dev_open);
 
-static int __dev_close_many(struct list_head *head)
+static void __dev_close_many(struct list_head *head)
 {
 	struct net_device *dev;
 
@@ -1455,23 +1455,18 @@ static int __dev_close_many(struct list_head *head)
 		dev->flags &= ~IFF_UP;
 		netpoll_poll_enable(dev);
 	}
-
-	return 0;
 }
 
-static int __dev_close(struct net_device *dev)
+static void __dev_close(struct net_device *dev)
 {
-	int retval;
 	LIST_HEAD(single);
 
 	list_add(&dev->close_list, &single);
-	retval = __dev_close_many(&single);
+	__dev_close_many(&single);
 	list_del(&single);
-
-	return retval;
 }
 
-int dev_close_many(struct list_head *head, bool unlink)
+void dev_close_many(struct list_head *head, bool unlink)
 {
 	struct net_device *dev, *tmp;
 
@@ -1488,8 +1483,6 @@ int dev_close_many(struct list_head *head, bool unlink)
 		if (unlink)
 			list_del_init(&dev->close_list);
 	}
-
-	return 0;
 }
 EXPORT_SYMBOL(dev_close_many);
 
@@ -1502,7 +1495,7 @@ EXPORT_SYMBOL(dev_close_many);
  *	is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
  *	chain.
  */
-int dev_close(struct net_device *dev)
+void dev_close(struct net_device *dev)
 {
 	if (dev->flags & IFF_UP) {
 		LIST_HEAD(single);
@@ -1511,7 +1504,6 @@ int dev_close(struct net_device *dev)
 		dev_close_many(&single, true);
 		list_del(&single);
 	}
-	return 0;
 }
 EXPORT_SYMBOL(dev_close);
 
@@ -6725,8 +6717,12 @@ int __dev_change_flags(struct net_device *dev, unsigned int flags)
 	 */
 
 	ret = 0;
-	if ((old_flags ^ flags) & IFF_UP)
-		ret = ((old_flags & IFF_UP) ? __dev_close : __dev_open)(dev);
+	if ((old_flags ^ flags) & IFF_UP) {
+		if (old_flags & IFF_UP)
+			__dev_close(dev);
+		else
+			ret = __dev_open(dev);
+	}
 
 	if ((flags ^ dev->gflags) & IFF_PROMISC) {
 		int inc = (flags & IFF_PROMISC) ? 1 : -1;
-- 
2.11.0

Re: [PATCH net-next 0/3] net: make dev_close void

[David Miller]

From: Stephen Hemminger <stephen@networkplumber.org>
Date: Tue, 18 Jul 2017 15:59:24 -0700

> Noticed while working on other changes. Why is dev_close()
> returning int, it should be void.  Should also change
> ndo_close to be void, but that requires more work and someone
> with more coccinelle foo (smpl) than me.

Series applied, thanks.

Re: [PATCH net-next 1/3] bluetooth: 6lowpan dev_close never returns error

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 1545 bytes --]

Hi Stephen,

[auto build test WARNING on net-next/master]

url:    https://github.com/0day-ci/linux/commits/Stephen-Hemminger/net-make-dev_close-void/20170720-090123
config: x86_64-randconfig-a0-07211734 (attached as .config)
compiler: gcc-4.4 (Debian 4.4.7-8) 4.4.7
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All warnings (new ones prefixed by >>):

   net/bluetooth/6lowpan.c: In function 'ifdown':
>> net/bluetooth/6lowpan.c:621: warning: unused variable 'err'

vim +/err +621 net/bluetooth/6lowpan.c

18722c24 Jukka Rissanen    2013-12-11  618  
7f118253 Jukka Rissanen    2014-06-18  619  static void ifdown(struct net_device *netdev)
7f118253 Jukka Rissanen    2014-06-18  620  {
7f118253 Jukka Rissanen    2014-06-18 @621  	int err;
7f118253 Jukka Rissanen    2014-06-18  622  
7f118253 Jukka Rissanen    2014-06-18  623  	rtnl_lock();
ca74f73e Stephen Hemminger 2017-07-18  624  	dev_close(netdev);
7f118253 Jukka Rissanen    2014-06-18  625  	rtnl_unlock();
7f118253 Jukka Rissanen    2014-06-18  626  }
7f118253 Jukka Rissanen    2014-06-18  627  

:::::: The code at line 621 was first introduced by commit
:::::: 7f118253820fc3ad38659485adb3ebdfe64820e1 Bluetooth: 6LoWPAN: Remove network devices when unloading

:::::: TO: Jukka Rissanen <jukka.rissanen@linux.intel.com>
:::::: CC: Marcel Holtmann <marcel@holtmann.org>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 30222 bytes --]

Re: [PATCH net-next 1/3] bluetooth: 6lowpan dev_close never returns error

[Marcel Holtmann]

Hi Stephen,

> [auto build test WARNING on net-next/master]
> 
> url:    https://github.com/0day-ci/linux/commits/Stephen-Hemminger/net-make-dev_close-void/20170720-090123
> config: x86_64-randconfig-a0-07211734 (attached as .config)
> compiler: gcc-4.4 (Debian 4.4.7-8) 4.4.7
> reproduce:
>        # save the attached .config to linux build tree
>        make ARCH=x86_64 
> 
> All warnings (new ones prefixed by >>):
> 
>   net/bluetooth/6lowpan.c: In function 'ifdown':
>>> net/bluetooth/6lowpan.c:621: warning: unused variable 'err'
> 
> vim +/err +621 net/bluetooth/6lowpan.c
> 
> 18722c24 Jukka Rissanen    2013-12-11  618  
> 7f118253 Jukka Rissanen    2014-06-18  619  static void ifdown(struct net_device *netdev)
> 7f118253 Jukka Rissanen    2014-06-18  620  {
> 7f118253 Jukka Rissanen    2014-06-18 @621  	int err;
> 7f118253 Jukka Rissanen    2014-06-18  622  
> 7f118253 Jukka Rissanen    2014-06-18  623  	rtnl_lock();
> ca74f73e Stephen Hemminger 2017-07-18  624  	dev_close(netdev);
> 7f118253 Jukka Rissanen    2014-06-18  625  	rtnl_unlock();
> 7f118253 Jukka Rissanen    2014-06-18  626  }
> 7f118253 Jukka Rissanen    2014-06-18  627  
> 
> :::::: The code at line 621 was first introduced by commit
> :::::: 7f118253820fc3ad38659485adb3ebdfe64820e1 Bluetooth: 6LoWPAN: Remove network devices when unloading
> 
> :::::: TO: Jukka Rissanen <jukka.rissanen@linux.intel.com>
> :::::: CC: Marcel Holtmann <marcel@holtmann.org>

are you going to send a fix for this?

Regards

Marcel