Commit fc766e4c authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

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: default avatarEric Dumazet <eric.dumazet@gmail.com>
Acked-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e4a7b93b

include/linux/netdevice.h

+1 −1
Original line number Diff line number Diff line
@@ -951,7 +951,7 @@ struct net_device { 
#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 */

include/net/dn_dev.h

+18 −9
Original line number Diff line number Diff line
@@ -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_parms { 




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 @@ extern int unregister_dnaddr_notifier(struct notifier_block *nb); 


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 */

include/net/dst.h

+4 −4
Original line number Diff line number Diff line
@@ -97,7 +97,7 @@ struct dst_entry { 
		struct dst_entry	*next;

		struct rtable __rcu	*rt_next;

		struct rt6_info		*rt6_next;

		struct dn_route  *dn_next;

		struct dn_route __rcu	*dn_next;

	};

};

net/decnet/af_decnet.c

+1 −1
Original line number Diff line number Diff line
@@ -1848,7 +1848,7 @@ unsigned dn_mss_from_pmtu(struct net_device *dev, int mtu) 
{

	unsigned mss = 230 - DN_MAX_NSP_DATA_HEADER;

	if (dev) {

		struct dn_dev *dn_db = dev->dn_ptr;

		struct dn_dev *dn_db = rcu_dereference_raw(dev->dn_ptr);

		mtu -= LL_RESERVED_SPACE(dev);

		if (dn_db->use_long)

			mtu -= 21;

net/decnet/dn_dev.c

+59 −41
Original line number Diff line number Diff line
@@ -267,7 +267,7 @@ static int dn_forwarding_proc(ctl_table *table, int write, 
	if (table->extra1 == NULL)

		return -EINVAL;



	dn_db = dev->dn_ptr;

	dn_db = rcu_dereference_raw(dev->dn_ptr);

	old = dn_db->parms.forwarding;



	err = proc_dointvec(table, write, buffer, lenp, ppos);
@@ -332,14 +332,19 @@ static struct dn_ifaddr *dn_dev_alloc_ifa(void) 
	return ifa;

}



static __inline__ void dn_dev_free_ifa(struct dn_ifaddr *ifa)

static void dn_dev_free_ifa_rcu(struct rcu_head *head)

{

	kfree(ifa);

	kfree(container_of(head, struct dn_ifaddr, rcu));

}



static void dn_dev_del_ifa(struct dn_dev *dn_db, struct dn_ifaddr **ifap, int destroy)

static void dn_dev_free_ifa(struct dn_ifaddr *ifa)

{

	struct dn_ifaddr *ifa1 = *ifap;

	call_rcu(&ifa->rcu, dn_dev_free_ifa_rcu);

}



static void dn_dev_del_ifa(struct dn_dev *dn_db, struct dn_ifaddr __rcu **ifap, int destroy)

{

	struct dn_ifaddr *ifa1 = rtnl_dereference(*ifap);

	unsigned char mac_addr[6];

	struct net_device *dev = dn_db->dev;
@@ -373,7 +378,9 @@ static int dn_dev_insert_ifa(struct dn_dev *dn_db, struct dn_ifaddr *ifa) 
	ASSERT_RTNL();



	/* Check for duplicates */

	for(ifa1 = dn_db->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {

	for (ifa1 = rtnl_dereference(dn_db->ifa_list);

	     ifa1 != NULL;

	     ifa1 = rtnl_dereference(ifa1->ifa_next)) {

		if (ifa1->ifa_local == ifa->ifa_local)

			return -EEXIST;

	}
@@ -386,7 +393,7 @@ static int dn_dev_insert_ifa(struct dn_dev *dn_db, struct dn_ifaddr *ifa) 
	}



	ifa->ifa_next = dn_db->ifa_list;

	dn_db->ifa_list = ifa;

	rcu_assign_pointer(dn_db->ifa_list, ifa);



	dn_ifaddr_notify(RTM_NEWADDR, ifa);

	blocking_notifier_call_chain(&dnaddr_chain, NETDEV_UP, ifa);
@@ -396,7 +403,7 @@ static int dn_dev_insert_ifa(struct dn_dev *dn_db, struct dn_ifaddr *ifa) 


static int dn_dev_set_ifa(struct net_device *dev, struct dn_ifaddr *ifa)

{

	struct dn_dev *dn_db = dev->dn_ptr;

	struct dn_dev *dn_db = rtnl_dereference(dev->dn_ptr);

	int rv;



	if (dn_db == NULL) {
@@ -425,7 +432,8 @@ int dn_dev_ioctl(unsigned int cmd, void __user *arg) 
	struct sockaddr_dn *sdn = (struct sockaddr_dn *)&ifr->ifr_addr;

	struct dn_dev *dn_db;

	struct net_device *dev;

	struct dn_ifaddr *ifa = NULL, **ifap = NULL;

	struct dn_ifaddr *ifa = NULL;

	struct dn_ifaddr __rcu **ifap = NULL;

	int ret = 0;



	if (copy_from_user(ifr, arg, DN_IFREQ_SIZE))
@@ -454,8 +462,10 @@ int dn_dev_ioctl(unsigned int cmd, void __user *arg) 
		goto done;

	}



	if ((dn_db = dev->dn_ptr) != NULL) {

		for (ifap = &dn_db->ifa_list; (ifa=*ifap) != NULL; ifap = &ifa->ifa_next)

	if ((dn_db = rtnl_dereference(dev->dn_ptr)) != NULL) {

		for (ifap = &dn_db->ifa_list;

		     (ifa = rtnl_dereference(*ifap)) != NULL;

		     ifap = &ifa->ifa_next)

			if (strcmp(ifr->ifr_name, ifa->ifa_label) == 0)

				break;

	}
@@ -558,7 +568,7 @@ static struct dn_dev *dn_dev_by_index(int ifindex) 


	dev = __dev_get_by_index(&init_net, ifindex);

	if (dev)

		dn_dev = dev->dn_ptr;

		dn_dev = rtnl_dereference(dev->dn_ptr);



	return dn_dev;

}
@@ -576,7 +586,8 @@ static int dn_nl_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 
	struct nlattr *tb[IFA_MAX+1];

	struct dn_dev *dn_db;

	struct ifaddrmsg *ifm;

	struct dn_ifaddr *ifa, **ifap;

	struct dn_ifaddr *ifa;

	struct dn_ifaddr __rcu **ifap;

	int err = -EINVAL;



	if (!net_eq(net, &init_net))
@@ -592,7 +603,9 @@ static int dn_nl_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 
		goto errout;



	err = -EADDRNOTAVAIL;

	for (ifap = &dn_db->ifa_list; (ifa = *ifap); ifap = &ifa->ifa_next) {

	for (ifap = &dn_db->ifa_list;

	     (ifa = rtnl_dereference(*ifap)) != NULL;

	     ifap = &ifa->ifa_next) {

		if (tb[IFA_LOCAL] &&

		    nla_memcmp(tb[IFA_LOCAL], &ifa->ifa_local, 2))

			continue;
@@ -632,7 +645,7 @@ static int dn_nl_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 
	if ((dev = __dev_get_by_index(&init_net, ifm->ifa_index)) == NULL)

		return -ENODEV;



	if ((dn_db = dev->dn_ptr) == NULL) {

	if ((dn_db = rtnl_dereference(dev->dn_ptr)) == NULL) {

		dn_db = dn_dev_create(dev, &err);

		if (!dn_db)

			return err;
@@ -748,11 +761,11 @@ static int dn_nl_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb) 
			skip_naddr = 0;

		}



		if ((dn_db = dev->dn_ptr) == NULL)

		if ((dn_db = rtnl_dereference(dev->dn_ptr)) == NULL)

			goto cont;



		for (ifa = dn_db->ifa_list, dn_idx = 0; ifa;

		     ifa = ifa->ifa_next, dn_idx++) {

		for (ifa = rtnl_dereference(dn_db->ifa_list), dn_idx = 0; ifa;

		     ifa = rtnl_dereference(ifa->ifa_next), dn_idx++) {

			if (dn_idx < skip_naddr)

				continue;
@@ -773,21 +786,22 @@ done: 


static int dn_dev_get_first(struct net_device *dev, __le16 *addr)

{

	struct dn_dev *dn_db = (struct dn_dev *)dev->dn_ptr;

	struct dn_dev *dn_db;

	struct dn_ifaddr *ifa;

	int rv = -ENODEV;



	rcu_read_lock();

	dn_db = rcu_dereference(dev->dn_ptr);

	if (dn_db == NULL)

		goto out;



	rtnl_lock();

	ifa = dn_db->ifa_list;

	ifa = rcu_dereference(dn_db->ifa_list);

	if (ifa != NULL) {

		*addr = ifa->ifa_local;

		rv = 0;

	}

	rtnl_unlock();

out:

	rcu_read_unlock();

	return rv;

}
@@ -823,7 +837,7 @@ static void dn_send_endnode_hello(struct net_device *dev, struct dn_ifaddr *ifa) 
	struct endnode_hello_message *msg;

	struct sk_buff *skb = NULL;

	__le16 *pktlen;

	struct dn_dev *dn_db = (struct dn_dev *)dev->dn_ptr;

	struct dn_dev *dn_db = rcu_dereference_raw(dev->dn_ptr);



	if ((skb = dn_alloc_skb(NULL, sizeof(*msg), GFP_ATOMIC)) == NULL)

		return;
@@ -889,7 +903,7 @@ static int dn_am_i_a_router(struct dn_neigh *dn, struct dn_dev *dn_db, struct dn 
static void dn_send_router_hello(struct net_device *dev, struct dn_ifaddr *ifa)

{

	int n;

	struct dn_dev *dn_db = dev->dn_ptr;

	struct dn_dev *dn_db = rcu_dereference_raw(dev->dn_ptr);

	struct dn_neigh *dn = (struct dn_neigh *)dn_db->router;

	struct sk_buff *skb;

	size_t size;
@@ -960,7 +974,7 @@ static void dn_send_router_hello(struct net_device *dev, struct dn_ifaddr *ifa) 


static void dn_send_brd_hello(struct net_device *dev, struct dn_ifaddr *ifa)

{

	struct dn_dev *dn_db = (struct dn_dev *)dev->dn_ptr;

	struct dn_dev *dn_db = rcu_dereference_raw(dev->dn_ptr);



	if (dn_db->parms.forwarding == 0)

		dn_send_endnode_hello(dev, ifa);
@@ -998,7 +1012,7 @@ static void dn_send_ptp_hello(struct net_device *dev, struct dn_ifaddr *ifa) 


static int dn_eth_up(struct net_device *dev)

{

	struct dn_dev *dn_db = dev->dn_ptr;

	struct dn_dev *dn_db = rcu_dereference_raw(dev->dn_ptr);



	if (dn_db->parms.forwarding == 0)

		dev_mc_add(dev, dn_rt_all_end_mcast);
@@ -1012,7 +1026,7 @@ static int dn_eth_up(struct net_device *dev) 


static void dn_eth_down(struct net_device *dev)

{

	struct dn_dev *dn_db = dev->dn_ptr;

	struct dn_dev *dn_db = rcu_dereference_raw(dev->dn_ptr);



	if (dn_db->parms.forwarding == 0)

		dev_mc_del(dev, dn_rt_all_end_mcast);
@@ -1025,12 +1039,16 @@ static void dn_dev_set_timer(struct net_device *dev); 
static void dn_dev_timer_func(unsigned long arg)

{

	struct net_device *dev = (struct net_device *)arg;

	struct dn_dev *dn_db = dev->dn_ptr;

	struct dn_dev *dn_db;

	struct dn_ifaddr *ifa;



	rcu_read_lock();

	dn_db = rcu_dereference(dev->dn_ptr);

	if (dn_db->t3 <= dn_db->parms.t2) {

		if (dn_db->parms.timer3) {

			for(ifa = dn_db->ifa_list; ifa; ifa = ifa->ifa_next) {

			for (ifa = rcu_dereference(dn_db->ifa_list);

			     ifa;

			     ifa = rcu_dereference(ifa->ifa_next)) {

				if (!(ifa->ifa_flags & IFA_F_SECONDARY))

					dn_db->parms.timer3(dev, ifa);

			}
@@ -1039,13 +1057,13 @@ static void dn_dev_timer_func(unsigned long arg) 
	} else {

		dn_db->t3 -= dn_db->parms.t2;

	}



	rcu_read_unlock();

	dn_dev_set_timer(dev);

}



static void dn_dev_set_timer(struct net_device *dev)

{

	struct dn_dev *dn_db = dev->dn_ptr;

	struct dn_dev *dn_db = rcu_dereference_raw(dev->dn_ptr);



	if (dn_db->parms.t2 > dn_db->parms.t3)

		dn_db->parms.t2 = dn_db->parms.t3;
@@ -1077,8 +1095,8 @@ static struct dn_dev *dn_dev_create(struct net_device *dev, int *err) 
		return NULL;



	memcpy(&dn_db->parms, p, sizeof(struct dn_dev_parms));

	smp_wmb();

	dev->dn_ptr = dn_db;



	rcu_assign_pointer(dev->dn_ptr, dn_db);

	dn_db->dev = dev;

	init_timer(&dn_db->timer);
@@ -1086,7 +1104,7 @@ static struct dn_dev *dn_dev_create(struct net_device *dev, int *err) 


	dn_db->neigh_parms = neigh_parms_alloc(dev, &dn_neigh_table);

	if (!dn_db->neigh_parms) {

		dev->dn_ptr = NULL;

		rcu_assign_pointer(dev->dn_ptr, NULL);

		kfree(dn_db);

		return NULL;

	}
@@ -1125,7 +1143,7 @@ void dn_dev_up(struct net_device *dev) 
	struct dn_ifaddr *ifa;

	__le16 addr = decnet_address;

	int maybe_default = 0;

	struct dn_dev *dn_db = (struct dn_dev *)dev->dn_ptr;

	struct dn_dev *dn_db = rtnl_dereference(dev->dn_ptr);



	if ((dev->type != ARPHRD_ETHER) && (dev->type != ARPHRD_LOOPBACK))

		return;
@@ -1176,7 +1194,7 @@ void dn_dev_up(struct net_device *dev) 


static void dn_dev_delete(struct net_device *dev)

{

	struct dn_dev *dn_db = dev->dn_ptr;

	struct dn_dev *dn_db = rtnl_dereference(dev->dn_ptr);



	if (dn_db == NULL)

		return;
@@ -1204,13 +1222,13 @@ static void dn_dev_delete(struct net_device *dev) 


void dn_dev_down(struct net_device *dev)

{

	struct dn_dev *dn_db = dev->dn_ptr;

	struct dn_dev *dn_db = rtnl_dereference(dev->dn_ptr);

	struct dn_ifaddr *ifa;



	if (dn_db == NULL)

		return;



	while((ifa = dn_db->ifa_list) != NULL) {

	while ((ifa = rtnl_dereference(dn_db->ifa_list)) != NULL) {

		dn_dev_del_ifa(dn_db, &dn_db->ifa_list, 0);

		dn_dev_free_ifa(ifa);

	}
@@ -1270,7 +1288,7 @@ static inline int is_dn_dev(struct net_device *dev) 
}



static void *dn_dev_seq_start(struct seq_file *seq, loff_t *pos)

	__acquires(rcu)

	__acquires(RCU)

{

	int i;

	struct net_device *dev;
@@ -1313,7 +1331,7 @@ static void *dn_dev_seq_next(struct seq_file *seq, void *v, loff_t *pos) 
}



static void dn_dev_seq_stop(struct seq_file *seq, void *v)

	__releases(rcu)

	__releases(RCU)

{

	rcu_read_unlock();

}
@@ -1340,7 +1358,7 @@ static int dn_dev_seq_show(struct seq_file *seq, void *v) 
		struct net_device *dev = v;

		char peer_buf[DN_ASCBUF_LEN];

		char router_buf[DN_ASCBUF_LEN];

		struct dn_dev *dn_db = dev->dn_ptr;

		struct dn_dev *dn_db = rcu_dereference(dev->dn_ptr);



		seq_printf(seq, "%-8s %1s     %04u %04u   %04lu %04lu"

				"   %04hu    %03d %02x    %-10s %-7s %-7s\n",

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