decnet: RCU conversion and get rid of dev_base_lock
While tracking dev_base_lock users, I found decnet used it in
dnet_select_source(), but for a wrong purpose:
Writers only hold RTNL, not dev_base_lock, so readers must use RCU if
they cannot use RTNL.
Adds an rcu_head in struct dn_ifaddr and handle proper RCU management.
Adds __rcu annotation in dn_route as well.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index d8fd2c2..578debb 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -951,7 +951,7 @@
#endif
void *atalk_ptr; /* AppleTalk link */
struct in_device __rcu *ip_ptr; /* IPv4 specific data */
- void *dn_ptr; /* DECnet specific data */
+ struct dn_dev __rcu *dn_ptr; /* DECnet specific data */
struct inet6_dev __rcu *ip6_ptr; /* IPv6 specific data */
void *ec_ptr; /* Econet specific data */
void *ax25_ptr; /* AX.25 specific data */
diff --git a/include/net/dn_dev.h b/include/net/dn_dev.h
index 0916bbf..b9e32db 100644
--- a/include/net/dn_dev.h
+++ b/include/net/dn_dev.h
@@ -5,13 +5,14 @@
struct dn_dev;
struct dn_ifaddr {
- struct dn_ifaddr *ifa_next;
+ struct dn_ifaddr __rcu *ifa_next;
struct dn_dev *ifa_dev;
__le16 ifa_local;
__le16 ifa_address;
__u8 ifa_flags;
__u8 ifa_scope;
char ifa_label[IFNAMSIZ];
+ struct rcu_head rcu;
};
#define DN_DEV_S_RU 0 /* Run - working normally */
@@ -83,7 +84,7 @@
struct dn_dev {
- struct dn_ifaddr *ifa_list;
+ struct dn_ifaddr __rcu *ifa_list;
struct net_device *dev;
struct dn_dev_parms parms;
char use_long;
@@ -171,19 +172,27 @@
static inline int dn_dev_islocal(struct net_device *dev, __le16 addr)
{
- struct dn_dev *dn_db = dev->dn_ptr;
+ struct dn_dev *dn_db;
struct dn_ifaddr *ifa;
+ int res = 0;
+ rcu_read_lock();
+ dn_db = rcu_dereference(dev->dn_ptr);
if (dn_db == NULL) {
printk(KERN_DEBUG "dn_dev_islocal: Called for non DECnet device\n");
- return 0;
+ goto out;
}
- for(ifa = dn_db->ifa_list; ifa; ifa = ifa->ifa_next)
- if ((addr ^ ifa->ifa_local) == 0)
- return 1;
-
- return 0;
+ for (ifa = rcu_dereference(dn_db->ifa_list);
+ ifa != NULL;
+ ifa = rcu_dereference(ifa->ifa_next))
+ if ((addr ^ ifa->ifa_local) == 0) {
+ res = 1;
+ break;
+ }
+out:
+ rcu_read_unlock();
+ return res;
}
#endif /* _NET_DN_DEV_H */
diff --git a/include/net/dst.h b/include/net/dst.h
index ffe9cb7..a5bd726 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -94,10 +94,10 @@
int __use;
unsigned long lastuse;
union {
- struct dst_entry *next;
- struct rtable __rcu *rt_next;
- struct rt6_info *rt6_next;
- struct dn_route *dn_next;
+ struct dst_entry *next;
+ struct rtable __rcu *rt_next;
+ struct rt6_info *rt6_next;
+ struct dn_route __rcu *dn_next;
};
};