C++ write_lock_bh函数代码示例

int br_add_if(struct net_bridge *br, struct net_device *dev)
{
	struct net_bridge_port *p;

	if (dev->br_port != NULL)
		return -EBUSY;

#if 0
	if (dev->flags & IFF_LOOPBACK || dev->type != ARPHRD_ETHER)
		return -EINVAL;
#endif

	if (dev->hard_start_xmit == br_dev_xmit)
		return -ELOOP;

	if (!is_valid_ether_addr(dev->dev_addr))
		return -EADDRNOTAVAIL;

	dev_hold(dev);
	write_lock_bh(&br->lock);
	if ((p = new_nbp(br, dev)) == NULL) {
		write_unlock_bh(&br->lock);
		dev_put(dev);
		return -EXFULL;
	}

	dev_set_promiscuity(dev, 1);

	br_stp_recalculate_bridge_id(br);
	br_fdb_insert(br, p, dev->dev_addr, 1);
	if ((br->dev.flags & IFF_UP) && (dev->flags & IFF_UP))
		br_stp_enable_port(p);
	write_unlock_bh(&br->lock);

	return 0;
}

/* Call this every MPC-p2 seconds... Not exactly correct solution,
   but an easy one... */
static void clear_count_and_expired(struct mpoa_client *client)
{
    in_cache_entry *entry, *next_entry;
    struct timeval now;

    do_gettimeofday(&now);

    write_lock_bh(&client->ingress_lock);
    entry = client->in_cache;
    while(entry != NULL) {
        entry->count=0;
        next_entry = entry->next;
        if((now.tv_sec - entry->tv.tv_sec)
                > entry->ctrl_info.holding_time) {
            dprintk("mpoa: mpoa_caches.c: holding time expired, ip = %pI4\n",
                    &entry->ctrl_info.in_dst_ip);
            client->in_ops->remove_entry(entry, client);
        }
        entry = next_entry;
    }
    write_unlock_bh(&client->ingress_lock);

    return;
}

struct in_device *inetdev_init(struct net_device *dev)
{
	struct in_device *in_dev;

	ASSERT_RTNL();

	in_dev = kmalloc(sizeof(*in_dev), GFP_KERNEL);
	if (!in_dev)
		return NULL;
	memset(in_dev, 0, sizeof(*in_dev));
	in_dev->lock = RW_LOCK_UNLOCKED;
	memcpy(&in_dev->cnf, &ipv4_devconf_dflt, sizeof(in_dev->cnf));
	in_dev->cnf.sysctl = NULL;
	in_dev->dev = dev;
	if ((in_dev->arp_parms = neigh_parms_alloc(dev, &arp_tbl)) == NULL) {
		kfree(in_dev);
		return NULL;
	}
	inet_dev_count++;
	/* Reference in_dev->dev */
	dev_hold(dev);
#ifdef CONFIG_SYSCTL
	neigh_sysctl_register(dev, in_dev->arp_parms, NET_IPV4, NET_IPV4_NEIGH, "ipv4");
#endif
	write_lock_bh(&inetdev_lock);
	dev->ip_ptr = in_dev;
	/* Account for reference dev->ip_ptr */
	in_dev_hold(in_dev);
	write_unlock_bh(&inetdev_lock);
#ifdef CONFIG_SYSCTL
	devinet_sysctl_register(in_dev, &in_dev->cnf);
#endif
	if (dev->flags&IFF_UP)
		ip_mc_up(in_dev);
	return in_dev;
}

static int sco_sock_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
{
	struct sockaddr_sco *sa = (struct sockaddr_sco *) addr;
	struct sock *sk = sock->sk;
	bdaddr_t *src = &sa->sco_bdaddr;
	int err = 0;

	BT_DBG("sk %p %s", sk, batostr(&sa->sco_bdaddr));

	if (!addr || addr->sa_family != AF_BLUETOOTH)
		return -EINVAL;

	lock_sock(sk);

	if (sk->state != BT_OPEN) {
		err = -EBADFD;
		goto done;
	}

	write_lock_bh(&sco_sk_list.lock);

	if (bacmp(src, BDADDR_ANY) && __sco_get_sock_by_addr(src)) {
		err = -EADDRINUSE;
	} else {
	/* Save source address */
	bacpy(&bluez_pi(sk)->src, &sa->sco_bdaddr);
	sk->state = BT_BOUND;
	}

	write_unlock_bh(&sco_sk_list.lock);

done:
	release_sock(sk);

	return err;
}

int nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto)
{
	int ret = 0;

	if (l4proto->l3proto >= PF_MAX) {
		ret = -EBUSY;
		goto out;
	}

	if (l4proto == &nf_conntrack_l4proto_generic) {
		nf_ct_l4proto_unregister_sysctl(l4proto);
		goto out;
	}

	write_lock_bh(&nf_conntrack_lock);
	if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto]
	    != l4proto) {
		write_unlock_bh(&nf_conntrack_lock);
		ret = -EBUSY;
		goto out;
	}
	nf_ct_protos[l4proto->l3proto][l4proto->l4proto]
		= &nf_conntrack_l4proto_generic;
	write_unlock_bh(&nf_conntrack_lock);

	nf_ct_l4proto_unregister_sysctl(l4proto);

	/* Somebody could be still looking at the proto in bh. */
	synchronize_net();

	/* Remove all contrack entries for this protocol */
	nf_ct_iterate_cleanup(kill_l4proto, l4proto);

out:
	return ret;
}

struct socket *rds_tcp_listen_init(struct net *net)
{
	struct sockaddr_in sin;
	struct socket *sock = NULL;
	int ret;

	ret = sock_create_kern(net, PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
	if (ret < 0)
		goto out;

	sock->sk->sk_reuse = SK_CAN_REUSE;
	rds_tcp_nonagle(sock);

	write_lock_bh(&sock->sk->sk_callback_lock);
	sock->sk->sk_user_data = sock->sk->sk_data_ready;
	sock->sk->sk_data_ready = rds_tcp_listen_data_ready;
	write_unlock_bh(&sock->sk->sk_callback_lock);

	sin.sin_family = PF_INET;
	sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
	sin.sin_port = (__force u16)htons(RDS_TCP_PORT);

	ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
	if (ret < 0)
		goto out;

	ret = sock->ops->listen(sock, 64);
	if (ret < 0)
		goto out;

	return sock;
out:
	if (sock)
		sock_release(sock);
	return NULL;
}

static void smc_buf_unuse(struct smc_connection *conn,
			  struct smc_link_group *lgr)
{
	if (conn->sndbuf_desc)
		conn->sndbuf_desc->used = 0;
	if (conn->rmb_desc) {
		if (!conn->rmb_desc->regerr) {
			conn->rmb_desc->used = 0;
			if (!lgr->is_smcd) {
				/* unregister rmb with peer */
				smc_llc_do_delete_rkey(
						&lgr->lnk[SMC_SINGLE_LINK],
						conn->rmb_desc);
			}
		} else {
			/* buf registration failed, reuse not possible */
			write_lock_bh(&lgr->rmbs_lock);
			list_del(&conn->rmb_desc->list);
			write_unlock_bh(&lgr->rmbs_lock);

			smc_buf_free(lgr, true, conn->rmb_desc);
		}
	}
}

/**
 * xs_close - close a socket
 * @xprt: transport
 *
 * This is used when all requests are complete; ie, no DRC state remains
 * on the server we want to save.
 */
static void xs_close(struct rpc_xprt *xprt)
{
	struct socket *sock = xprt->sock;
	struct sock *sk = xprt->inet;

	if (!sk)
		return;

	dprintk("RPC:      xs_close xprt %p\n", xprt);

	write_lock_bh(&sk->sk_callback_lock);
	xprt->inet = NULL;
	xprt->sock = NULL;

	sk->sk_user_data = NULL;
	sk->sk_data_ready = xprt->old_data_ready;
	sk->sk_state_change = xprt->old_state_change;
	sk->sk_write_space = xprt->old_write_space;
	write_unlock_bh(&sk->sk_callback_lock);

	sk->sk_no_check = 0;

	sock_release(sock);
}

int ax25_protocol_register(unsigned int pid,
	int (*func)(struct sk_buff *, ax25_cb *))
{
	struct protocol_struct *protocol;

	if (pid == AX25_P_TEXT || pid == AX25_P_SEGMENT)
		return 0;
#ifdef CONFIG_INET
	if (pid == AX25_P_IP || pid == AX25_P_ARP)
		return 0;
#endif
	if ((protocol = kmalloc(sizeof(*protocol), GFP_ATOMIC)) == NULL)
		return 0;

	protocol->pid  = pid;
	protocol->func = func;

	write_lock_bh(&protocol_list_lock);
	protocol->next = protocol_list;
	protocol_list  = protocol;
	write_unlock_bh(&protocol_list_lock);

	return 1;
}

void ip_mc_dec_group(struct in_device *in_dev, u32 addr)
{
    struct ip_mc_list *i, **ip;

    ASSERT_RTNL();

    for (ip=&in_dev->mc_list; (i=*ip)!=NULL; ip=&i->next) {
        if (i->multiaddr==addr) {
            if (--i->users == 0) {
                write_lock_bh(&in_dev->lock);
                *ip = i->next;
                write_unlock_bh(&in_dev->lock);
                igmp_group_dropped(i);

                if (in_dev->dev->flags & IFF_UP)
                    ip_rt_multicast_event(in_dev);

                ip_ma_put(i);
                return;
            }
            break;
        }
    }
}

/*
 * 	inserts (in front) a new entry in hash table, 
 * 	called from ipsec_alg_register() when new algorithm is registered.
 */
static int ipsec_alg_insert(struct ipsec_alg *ixt) {
	int ret=-EINVAL;
	unsigned hashval=ipsec_alg_hashfn(ixt->ixt_alg_type, ixt->ixt_alg_id);
	struct list_head *head= ipsec_alg_hash_table + hashval;
	/* 	new element must be virgin ... */
	if (ixt->ixt_list.next != &ixt->ixt_list || 
		ixt->ixt_list.prev != &ixt->ixt_list) {
		printk(KERN_ERR "%s: ixt object \"%s\" "
				"list head not initialized\n",
				__FUNCTION__, ixt->ixt_name);
		return ret;
	}
	write_lock_bh(&ipsec_alg_lock);
	if (__ipsec_alg_find(ixt->ixt_alg_type, ixt->ixt_alg_id, head))
		barf_out(KERN_WARNING "ipsec_alg for alg_type=%d, alg_id=%d already exist."
				"Not loaded (ret=%d).\n",
				ixt->ixt_alg_type,
				ixt->ixt_alg_id, ret=-EEXIST);
	list_add(&ixt->ixt_list, head);
	ret=0;
out:
	write_unlock_bh(&ipsec_alg_lock);
	return ret;
}

static int fl_intern(struct ip6_flowlabel *fl, __be32 label)
{
	fl->label = label & IPV6_FLOWLABEL_MASK;

	write_lock_bh(&ip6_fl_lock);
	if (label == 0) {
		for (;;) {
			fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK;
			if (fl->label) {
				struct ip6_flowlabel *lfl;
				lfl = __fl_lookup(fl->label);
				if (lfl == NULL)
					break;
			}
		}
	}

	fl->lastuse = jiffies;
	fl->next = fl_ht[FL_HASH(fl->label)];
	fl_ht[FL_HASH(fl->label)] = fl;
	atomic_inc(&fl_size);
	write_unlock_bh(&ip6_fl_lock);
	return 0;
}

static int bond_option_arp_ip_target_rem(struct bonding *bond, __be32 target)
{
	__be32 *targets = bond->params.arp_targets;
	struct list_head *iter;
	struct slave *slave;
	unsigned long *targets_rx;
	int ind, i;

	if (IS_IP_TARGET_UNUSABLE_ADDRESS(target)) {
		pr_err("%s: invalid ARP target %pI4 specified for removal\n",
		       bond->dev->name, &target);
		return -EINVAL;
	}

	ind = bond_get_targets_ip(targets, target);
	if (ind == -1) {
		pr_err("%s: unable to remove nonexistent ARP target %pI4\n",
		       bond->dev->name, &target);
		return -EINVAL;
	}

	if (ind == 0 && !targets[1] && bond->params.arp_interval)
		pr_warn("%s: Removing last arp target with arp_interval on\n",
			bond->dev->name);

	pr_info("%s: Removing ARP target %pI4\n", bond->dev->name, &target);

	/* not to race with bond_arp_rcv */
	write_lock_bh(&bond->lock);

	bond_for_each_slave(bond, slave, iter) {
		targets_rx = slave->target_last_arp_rx;
		for (i = ind; (i < BOND_MAX_ARP_TARGETS-1) && targets[i+1]; i++)
			targets_rx[i] = targets_rx[i+1];
		targets_rx[i] = 0;
	}

static void rfc2863_policy(struct net_device *dev)
{
	unsigned char operstate = default_operstate(dev);

	if (operstate == dev->operstate)
		return;

	write_lock_bh(&dev_base_lock);

	switch(dev->link_mode) {
	case IF_LINK_MODE_DORMANT:
		if (operstate == IF_OPER_UP)
			operstate = IF_OPER_DORMANT;
		break;

	case IF_LINK_MODE_DEFAULT:
	default:
		break;
	}

	dev->operstate = operstate;

	write_unlock_bh(&dev_base_lock);
}

static void ingress_purge_rcvd(struct k_message *msg, struct mpoa_client *mpc)
{
	__be32 dst_ip = msg->content.in_info.in_dst_ip;
	__be32 mask = msg->ip_mask;
	in_cache_entry *entry = mpc->in_ops->get_with_mask(dst_ip, mpc, mask);

	if (entry == NULL) {
		pr_info("(%s) purge for a non-existing entry, ip = %pI4\n",
			mpc->dev->name, &dst_ip);
		return;
	}

	do {
		dprintk("(%s) removing an ingress entry, ip = %pI4\n",
			mpc->dev->name, &dst_ip);
		write_lock_bh(&mpc->ingress_lock);
		mpc->in_ops->remove_entry(entry, mpc);
		write_unlock_bh(&mpc->ingress_lock);
		mpc->in_ops->put(entry);
		entry = mpc->in_ops->get_with_mask(dst_ip, mpc, mask);
	} while (entry != NULL);

	return;
}