From 6756ae4b4e97aba48c042b4aa6b77a18f507d2cb Mon Sep 17 00:00:00 2001
From: Stephen Hemminger <shemminger@osdl.org>
Date: Mon, 20 Mar 2006 22:23:58 -0800
Subject: [NET]: Convert RTNL to mutex.

This patch turns the RTNL from a semaphore to a new 2.6.16 mutex and
gets rid of some of the leftover legacy.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/core/dev.c        |  8 ++++----
 net/core/link_watch.c |  4 ++--
 net/core/netpoll.c    |  6 +++---
 net/core/rtnetlink.c  | 28 +++++++++++++++++-----------
 4 files changed, 26 insertions(+), 20 deletions(-)

(limited to 'net/core')

diff --git a/net/core/dev.c b/net/core/dev.c
index 8763c99fcb8..be1d896cc5b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2466,9 +2466,9 @@ int dev_ioctl(unsigned int cmd, void __user *arg)
 	 */
 
 	if (cmd == SIOCGIFCONF) {
-		rtnl_shlock();
+		rtnl_lock();
 		ret = dev_ifconf((char __user *) arg);
-		rtnl_shunlock();
+		rtnl_unlock();
 		return ret;
 	}
 	if (cmd == SIOCGIFNAME)
@@ -2877,7 +2877,7 @@ static void netdev_wait_allrefs(struct net_device *dev)
 	rebroadcast_time = warning_time = jiffies;
 	while (atomic_read(&dev->refcnt) != 0) {
 		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
-			rtnl_shlock();
+			rtnl_lock();
 
 			/* Rebroadcast unregister notification */
 			notifier_call_chain(&netdev_chain,
@@ -2894,7 +2894,7 @@ static void netdev_wait_allrefs(struct net_device *dev)
 				linkwatch_run_queue();
 			}
 
-			rtnl_shunlock();
+			__rtnl_unlock();
 
 			rebroadcast_time = jiffies;
 		}
diff --git a/net/core/link_watch.c b/net/core/link_watch.c
index e82a451d330..341de44c7ed 100644
--- a/net/core/link_watch.c
+++ b/net/core/link_watch.c
@@ -139,9 +139,9 @@ static void linkwatch_event(void *dummy)
 	linkwatch_nextevent = jiffies + HZ;
 	clear_bit(LW_RUNNING, &linkwatch_flags);
 
-	rtnl_shlock();
+	rtnl_lock();
 	linkwatch_run_queue();
-	rtnl_shunlock();
+	rtnl_unlock();
 }
 
 
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index ea51f8d02eb..e8e05cebd95 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -669,14 +669,14 @@ int netpoll_setup(struct netpoll *np)
 		printk(KERN_INFO "%s: device %s not up yet, forcing it\n",
 		       np->name, np->dev_name);
 
-		rtnl_shlock();
+		rtnl_lock();
 		if (dev_change_flags(ndev, ndev->flags | IFF_UP) < 0) {
 			printk(KERN_ERR "%s: failed to open %s\n",
 			       np->name, np->dev_name);
-			rtnl_shunlock();
+			rtnl_unlock();
 			goto release;
 		}
-		rtnl_shunlock();
+		rtnl_unlock();
 
 		atleast = jiffies + HZ/10;
  		atmost = jiffies + 4*HZ;
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 1c15a907066..ae10d3740fa 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -35,6 +35,7 @@
 #include <linux/skbuff.h>
 #include <linux/init.h>
 #include <linux/security.h>
+#include <linux/mutex.h>
 
 #include <asm/uaccess.h>
 #include <asm/system.h>
@@ -51,25 +52,31 @@
 #include <net/pkt_sched.h>
 #include <net/netlink.h>
 
-DECLARE_MUTEX(rtnl_sem);
+static DEFINE_MUTEX(rtnl_mutex);
 
 void rtnl_lock(void)
 {
-	rtnl_shlock();
+	mutex_lock(&rtnl_mutex);
 }
 
-int rtnl_lock_interruptible(void)
+void __rtnl_unlock(void)
 {
-	return down_interruptible(&rtnl_sem);
+	mutex_unlock(&rtnl_mutex);
 }
- 
+
 void rtnl_unlock(void)
 {
-	rtnl_shunlock();
-
+	mutex_unlock(&rtnl_mutex);
+	if (rtnl && rtnl->sk_receive_queue.qlen)
+		rtnl->sk_data_ready(rtnl, 0);
 	netdev_run_todo();
 }
 
+int rtnl_trylock(void)
+{
+	return mutex_trylock(&rtnl_mutex);
+}
+
 int rtattr_parse(struct rtattr *tb[], int maxattr, struct rtattr *rta, int len)
 {
 	memset(tb, 0, sizeof(struct rtattr*)*maxattr);
@@ -625,9 +632,9 @@ static void rtnetlink_rcv(struct sock *sk, int len)
 	unsigned int qlen = 0;
 
 	do {
-		rtnl_lock();
+		mutex_lock(&rtnl_mutex);
 		netlink_run_queue(sk, &qlen, &rtnetlink_rcv_msg);
-		up(&rtnl_sem);
+		mutex_unlock(&rtnl_mutex);
 
 		netdev_run_todo();
 	} while (qlen);
@@ -704,6 +711,5 @@ EXPORT_SYMBOL(rtnetlink_links);
 EXPORT_SYMBOL(rtnetlink_put_metrics);
 EXPORT_SYMBOL(rtnl);
 EXPORT_SYMBOL(rtnl_lock);
-EXPORT_SYMBOL(rtnl_lock_interruptible);
-EXPORT_SYMBOL(rtnl_sem);
+EXPORT_SYMBOL(rtnl_trylock);
 EXPORT_SYMBOL(rtnl_unlock);
-- 
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