Commit 3deec3b4 authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Paolo Abeni
Browse files

phonet: Convert phonet_routes.lock to spinlock_t. 



route_doit() calls phonet_route_add() or phonet_route_del()
for RTM_NEWROUTE or RTM_DELROUTE, respectively.

Both functions only touch phonet_pernet(dev_net(dev))->routes,
which is currently protected by RTNL and its dedicated mutex,
phonet_routes.lock.

We will convert route_doit() to RCU and cannot use mutex inside RCU.

Let's convert the mutex to spinlock_t.

Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent de51ad08

include/net/phonet/pn_dev.h

+0 −1
Original line number Diff line number Diff line
@@ -11,7 +11,6 @@ 
#define PN_DEV_H



#include <linux/list.h>

#include <linux/mutex.h>

#include <linux/spinlock.h>



struct net;

net/phonet/pn_dev.c

+14 −9
Original line number Diff line number Diff line
@@ -22,7 +22,7 @@ 
#include <net/phonet/pn_dev.h>



struct phonet_routes {

	struct mutex		lock;

	spinlock_t		lock;

	struct net_device __rcu	*table[64];

};
@@ -273,13 +273,15 @@ static void phonet_route_autodel(struct net_device *dev) 


	/* Remove left-over Phonet routes */

	bitmap_zero(deleted, 64);

	mutex_lock(&pnn->routes.lock);

	for (i = 0; i < 64; i++)



	spin_lock(&pnn->routes.lock);

	for (i = 0; i < 64; i++) {

		if (rcu_access_pointer(pnn->routes.table[i]) == dev) {

			RCU_INIT_POINTER(pnn->routes.table[i], NULL);

			set_bit(i, deleted);

		}

	mutex_unlock(&pnn->routes.lock);

	}

	spin_unlock(&pnn->routes.lock);



	if (bitmap_empty(deleted, 64))

		return; /* short-circuit RCU */
@@ -326,7 +328,7 @@ static int __net_init phonet_init_net(struct net *net) 


	INIT_LIST_HEAD(&pnn->pndevs.list);

	spin_lock_init(&pnn->pndevs.lock);

	mutex_init(&pnn->routes.lock);

	spin_lock_init(&pnn->routes.lock);

	return 0;

}
@@ -376,13 +378,15 @@ int phonet_route_add(struct net_device *dev, u8 daddr) 
	int err = -EEXIST;



	daddr = daddr >> 2;

	mutex_lock(&routes->lock);



	spin_lock(&routes->lock);

	if (routes->table[daddr] == NULL) {

		rcu_assign_pointer(routes->table[daddr], dev);

		dev_hold(dev);

		err = 0;

	}

	mutex_unlock(&routes->lock);

	spin_unlock(&routes->lock);



	return err;

}
@@ -392,12 +396,13 @@ int phonet_route_del(struct net_device *dev, u8 daddr) 
	struct phonet_routes *routes = &pnn->routes;



	daddr = daddr >> 2;

	mutex_lock(&routes->lock);



	spin_lock(&routes->lock);

	if (rcu_access_pointer(routes->table[daddr]) == dev)

		RCU_INIT_POINTER(routes->table[daddr], NULL);

	else

		dev = NULL;

	mutex_unlock(&routes->lock);

	spin_unlock(&routes->lock);



	if (!dev)

		return -ENOENT;