Commit 6c555490 authored by WANG Cong's avatar WANG Cong Committed by David S. Miller
Browse files

ipv6: drop useless rcu_read_lock() in anycast 



These code is now protected by rtnl lock, rcu read lock
is useless now.

Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8801d48c

include/linux/netdevice.h

+2 −2
Original line number Diff line number Diff line
@@ -2083,7 +2083,7 @@ void __dev_remove_pack(struct packet_type *pt); 
void dev_add_offload(struct packet_offload *po);

void dev_remove_offload(struct packet_offload *po);



struct net_device *dev_get_by_flags_rcu(struct net *net, unsigned short flags,

struct net_device *__dev_get_by_flags(struct net *net, unsigned short flags,

				      unsigned short mask);

struct net_device *dev_get_by_name(struct net *net, const char *name);

struct net_device *dev_get_by_name_rcu(struct net *net, const char *name);

net/core/dev.c

+8 −6
Original line number Diff line number Diff line
@@ -897,23 +897,25 @@ struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type) 
EXPORT_SYMBOL(dev_getfirstbyhwtype);



/**

 *	dev_get_by_flags_rcu - find any device with given flags

 *	__dev_get_by_flags - find any device with given flags

 *	@net: the applicable net namespace

 *	@if_flags: IFF_* values

 *	@mask: bitmask of bits in if_flags to check

 *

 *	Search for any interface with the given flags. Returns NULL if a device

 *	is not found or a pointer to the device. Must be called inside

 *	rcu_read_lock(), and result refcount is unchanged.

 *	rtnl_lock(), and result refcount is unchanged.

 */



struct net_device *dev_get_by_flags_rcu(struct net *net, unsigned short if_flags,

struct net_device *__dev_get_by_flags(struct net *net, unsigned short if_flags,

				      unsigned short mask)

{

	struct net_device *dev, *ret;



	ASSERT_RTNL();



	ret = NULL;

	for_each_netdev_rcu(net, dev) {

	for_each_netdev(net, dev) {

		if (((dev->flags ^ if_flags) & mask) == 0) {

			ret = dev;

			break;
@@ -921,7 +923,7 @@ struct net_device *dev_get_by_flags_rcu(struct net *net, unsigned short if_flags 
	}

	return ret;

}

EXPORT_SYMBOL(dev_get_by_flags_rcu);

EXPORT_SYMBOL(__dev_get_by_flags);



/**

 *	dev_valid_name - check if name is okay for network device

net/ipv6/anycast.c

+6 −12
Original line number Diff line number Diff line
@@ -78,7 +78,6 @@ int ipv6_sock_ac_join(struct sock *sk, int ifindex, const struct in6_addr *addr) 
	pac->acl_addr = *addr;



	rtnl_lock();

	rcu_read_lock();

	if (ifindex == 0) {

		struct rt6_info *rt;
@@ -91,11 +90,11 @@ int ipv6_sock_ac_join(struct sock *sk, int ifindex, const struct in6_addr *addr) 
			goto error;

		} else {

			/* router, no matching interface: just pick one */

			dev = dev_get_by_flags_rcu(net, IFF_UP,

			dev = __dev_get_by_flags(net, IFF_UP,

						 IFF_UP | IFF_LOOPBACK);

		}

	} else

		dev = dev_get_by_index_rcu(net, ifindex);

		dev = __dev_get_by_index(net, ifindex);



	if (dev == NULL) {

		err = -ENODEV;
@@ -137,7 +136,6 @@ int ipv6_sock_ac_join(struct sock *sk, int ifindex, const struct in6_addr *addr) 
	}



error:

	rcu_read_unlock();

	rtnl_unlock();

	if (pac)

		sock_kfree_s(sk, pac, sizeof(*pac));
@@ -174,11 +172,9 @@ int ipv6_sock_ac_drop(struct sock *sk, int ifindex, const struct in6_addr *addr) 
	spin_unlock_bh(&ipv6_sk_ac_lock);



	rtnl_lock();

	rcu_read_lock();

	dev = dev_get_by_index_rcu(net, pac->acl_ifindex);

	dev = __dev_get_by_index(net, pac->acl_ifindex);

	if (dev)

		ipv6_dev_ac_dec(dev, &pac->acl_addr);

	rcu_read_unlock();

	rtnl_unlock();



	sock_kfree_s(sk, pac, sizeof(*pac));
@@ -203,12 +199,11 @@ void ipv6_sock_ac_close(struct sock *sk) 


	prev_index = 0;

	rtnl_lock();

	rcu_read_lock();

	while (pac) {

		struct ipv6_ac_socklist *next = pac->acl_next;



		if (pac->acl_ifindex != prev_index) {

			dev = dev_get_by_index_rcu(net, pac->acl_ifindex);

			dev = __dev_get_by_index(net, pac->acl_ifindex);

			prev_index = pac->acl_ifindex;

		}

		if (dev)
@@ -216,7 +211,6 @@ void ipv6_sock_ac_close(struct sock *sk) 
		sock_kfree_s(sk, pac, sizeof(*pac));

		pac = next;

	}

	rcu_read_unlock();

	rtnl_unlock();

}
@@ -341,7 +335,7 @@ int __ipv6_dev_ac_dec(struct inet6_dev *idev, const struct in6_addr *addr) 
	return 0;

}



/* called with rcu_read_lock() */

/* called with rtnl_lock() */

static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr)

{

	struct inet6_dev *idev = __in6_dev_get(dev);