Subject: Re: [PATCH 01/21] RDS: Socket interface

From: Stephen Hemminger <[email-masked]>
Date: Mon, 26 Jan 2009 19:46:19 -0800

On Mon, 26 Jan 2009 18:17:38 -0800
Andy Grover <[email-masked]> wrote:

> Implement the RDS (Reliable Datagram Sockets) interface.
> 
> Signed-off-by: Andy Grover <[email-masked]>
> ---
>  drivers/infiniband/ulp/rds/af_rds.c |  677 +++++++++++++++++++++++++++++++++++
>  drivers/infiniband/ulp/rds/bind.c   |  202 +++++++++++
>  2 files changed, 879 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/infiniband/ulp/rds/af_rds.c
>  create mode 100644 drivers/infiniband/ulp/rds/bind.c
> 
> diff --git a/drivers/infiniband/ulp/rds/af_rds.c b/drivers/infiniband/ulp/rds/af_rds.c
> new file mode 100644
> index 0000000..7158438
> --- /dev/null
> +++ b/drivers/infiniband/ulp/rds/af_rds.c
> @@ -0,0 +1,677 @@
> +/*
> + * Copyright (c) 2006 Oracle.  All rights reserved.
> + *
> + * This software is available to you under a choice of one of two
> + * licenses.  You may choose to be licensed under the terms of the GNU
> + * General Public License (GPL) Version 2, available from the file
> + * COPYING in the main directory of this source tree, or the
> + * OpenIB.org BSD license below:
> + *
> + *     Redistribution and use in source and binary forms, with or
> + *     without modification, are permitted provided that the following
> + *     conditions are met:
> + *
> + *      - Redistributions of source code must retain the above
> + *        copyright notice, this list of conditions and the following
> + *        disclaimer.
> + *
> + *      - Redistributions in binary form must reproduce the above
> + *        copyright notice, this list of conditions and the following
> + *        disclaimer in the documentation and/or other materials
> + *        provided with the distribution.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
> + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
> + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
> + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
> + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
> + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
> + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
> + * SOFTWARE.
> + *
> + */
> +#include <linux/module.h>
> +#include <linux/errno.h>
> +#include <linux/kernel.h>
> +#include <linux/in.h>
> +#include <linux/poll.h>
> +#include <linux/version.h>
> +#include <net/sock.h>
> +
> +#include "rds.h"
> +#include "rdma.h"
> +
> +static int enable_rdma = 1;
> +
> +module_param(enable_rdma, int, 0444);
> +MODULE_PARM_DESC(enable_rdma, " Enable RDMA operations support");

Module parameter is a cop-out for not doing it right.

> +/* this is just used for stats gathering :/ */

Then I would think a high speed protocol would use per-cpu
and/or rcu.

> +static DEFINE_SPINLOCK(rds_sock_lock);
> +static unsigned long rds_sock_count;
> +static LIST_HEAD(rds_sock_list);
> +DECLARE_WAIT_QUEUE_HEAD(rds_poll_waitq);
> +
> +/*
> + * This is called as the final descriptor referencing this socket is closed.
> + * We have to unbind the socket so that another socket can be bound to the
> + * address it was using.
> + *
> + * We have to be careful about racing with the incoming path.  sock_orphan()
> + * sets SOCK_DEAD and we use that as an indicator to the rx path that new
> + * messages shouldn't be queued.
> + */
> +static int rds_release(struct socket *sock)
> +{
> +	struct sock *sk = sock->sk;
> +	struct rds_sock *rs;
> +	unsigned long flags;
> +
> +	if (sk == NULL)
> +		goto out;
> +
> +	rs = rds_sk_to_rs(sk);
> +
> +	sock_orphan(sk);
> +	/* Note - rds_clear_recv_queue grabs rs_recv_lock, so
> +	 * that ensures the recv path has completed messing
> +	 * with the socket. */
> +	rds_clear_recv_queue(rs);
> +	rds_cong_remove_socket(rs);
> +	rds_remove_bound(rs);
> +	rds_send_drop_to(rs, NULL);
> +	rds_rdma_drop_keys(rs);
> +	rds_notify_queue_get(rs, NULL);
> +
> +	spin_lock_irqsave(&rds_sock_lock, flags);
> +	list_del_init(&rs->rs_item);
> +	rds_sock_count--;
> +	spin_unlock_irqrestore(&rds_sock_lock, flags);
> +
> +	sock->sk = NULL;
> +	sock_put(sk);
> +out:
> +	return 0;
> +}
> +
> +/*
> + * Careful not to race with rds_release -> sock_orphan which clears sk_sleep.
> + * _bh() isn't OK here, we're called from interrupt handlers.  It's probably OK
> + * to wake the waitqueue after sk_sleep is clear as we hold a sock ref, but
> + * this seems more conservative.
> + * NB - normally, one would use sk_callback_lock for this, but we can
> + * get here from interrupts, whereas the network code grabs sk_callback_lock
> + * with _lock_bh only - so relying on sk_callback_lock introduces livelocks.
> + */
> +void rds_wake_sk_sleep(struct rds_sock *rs)
> +{
> +	unsigned long flags;
> +
> +	read_lock_irqsave(&rs->rs_recv_lock, flags);
> +	__rds_wake_sk_sleep(rds_rs_to_sk(rs));
> +	read_unlock_irqrestore(&rs->rs_recv_lock, flags);
> +}
> +
> +static int rds_getname(struct socket *sock, struct sockaddr *uaddr,
> +		       int *uaddr_len, int peer)
> +{
> +	struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
> +	struct rds_sock *rs = rds_sk_to_rs(sock->sk);
> +
> +	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
> +
> +	/* racey, don't care */
> +	if (peer) {
> +		if (!rs->rs_conn_addr)
> +			return -ENOTCONN;
> +
> +		sin->sin_port = rs->rs_conn_port;
> +		sin->sin_addr.s_addr = rs->rs_conn_addr;
> +	} else {
> +		sin->sin_port = rs->rs_bound_port;
> +		sin->sin_addr.s_addr = rs->rs_bound_addr;
> +	}
> +
> +	sin->sin_family = AF_INET;
> +
> +	*uaddr_len = sizeof(*sin);
> +	return 0;
> +}
> +
> +/*
> + * RDS' poll is without a doubt the least intuitive part of the interface,
> + * as POLLIN and POLLOUT do not behave entirely as you would expect from
> + * a network protocol.
> + *
> + * POLLIN is asserted if
> + *  -	there is data on the receive queue.
> + *  -	to signal that a previously congested destination may have become
> + *	uncongested
> + *  -	A notification has been queued to the socket (this can be a congestion
> + *	update, or a RDMA completion).
> + *
> + * POLLOUT is asserted if there is room on the send queue. This does not mean
> + * however, that the next sendmsg() call will succeed. If the application tries
> + * to send to a congested destination, the system call may still fail (and
> + * return ENOBUFS).
> + */
> +static unsigned int rds_poll(struct file *file, struct socket *sock,
> +			     poll_table *wait)
> +{
> +	struct sock *sk = sock->sk;
> +	struct rds_sock *rs = rds_sk_to_rs(sk);
> +	unsigned int mask = 0;
> +	unsigned long flags;
> +
> +	poll_wait(file, sk->sk_sleep, wait);
> +
> +	poll_wait(file, &rds_poll_waitq, wait);
> +
> +	read_lock_irqsave(&rs->rs_recv_lock, flags);
> +	if (!rs->rs_cong_monitor) {
> +		/* When a congestion map was updated, we signal POLLIN for
> +		 * "historical" reasons. Applications can also poll for
> +		 * WRBAND instead. */
> +		if (rds_cong_updated_since(&rs->rs_cong_track))
> +			mask |= (POLLIN | POLLRDNORM | POLLWRBAND);
> +	} else {
> +		spin_lock(&rs->rs_lock);
> +		if (rs->rs_cong_notify)
> +			mask |= (POLLIN | POLLRDNORM);
> +		spin_unlock(&rs->rs_lock);
> +	}
> +	if (!list_empty(&rs->rs_recv_queue)
> +	 || !list_empty(&rs->rs_notify_queue))
> +		mask |= (POLLIN | POLLRDNORM);
> +	if (rs->rs_snd_bytes < rds_sk_sndbuf(rs))
> +		mask |= (POLLOUT | POLLWRNORM);
> +	read_unlock_irqrestore(&rs->rs_recv_lock, flags);
> +
> +	return mask;
> +}
> +
> +static int rds_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
> +{
> +#ifdef KERNEL_HAS_CORE_CALLING_DEV_IOCTL
> +	return -ENOIOCTLCMD;
> +#endif /* KERNEL_HAS_CORE_CALLING_DEV_IOCTL */
> +#ifndef KERNEL_HAS_CORE_CALLING_DEV_IOCTL
> +	return dev_ioctl(cmd, (void __user *)arg);
> +#endif /* KERNEL_HAS_CORE_CALLING_DEV_IOCTL */
> +}
> +
> +static int rds_cancel_sent_to(struct rds_sock *rs, char __user *optval,
> +			      int len)
> +{
> +	struct sockaddr_in sin;
> +	int ret = 0;
> +
> +	/* racing with another thread binding seems ok here */
> +	if (rs->rs_bound_addr == 0) {
> +		ret = -ENOTCONN; /* XXX not a great errno */
> +		goto out;
> +	}
> +
> +	if (len < sizeof(struct sockaddr_in)) {
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	if (copy_from_user(&sin, optval, sizeof(sin))) {
> +		ret = -EFAULT;
> +		goto out;
> +	}
> +
> +	rds_send_drop_to(rs, &sin);
> +out:
> +	return ret;
> +}
> +
> +static int rds_set_bool_option(unsigned char *optvar, char __user *optval,
> +			       int optlen)
> +{
> +	int value;
> +
> +	if (optlen < sizeof(int))
> +		return -EINVAL;
> +	if (get_user(value, (int __user *) optval))
> +		return -EFAULT;
> +	*optvar = !!value;
> +	return 0;
> +}
> +
> +static int rds_cong_monitor(struct rds_sock *rs, char __user *optval,
> +			    int optlen)
> +{
> +	int ret;
> +
> +	ret = rds_set_bool_option(&rs->rs_cong_monitor, optval, optlen);
> +	if (ret == 0) {
> +		if (rs->rs_cong_monitor) {
> +			rds_cong_add_socket(rs);
> +		} else {
> +			rds_cong_remove_socket(rs);
> +			rs->rs_cong_mask = 0;
> +			rs->rs_cong_notify = 0;
> +		}
> +	}
> +	return ret;
> +}
> +
> +static int rds_setsockopt(struct socket *sock, int level, int optname,
> +			  char __user *optval, int optlen)
> +{
> +	struct rds_sock *rs = rds_sk_to_rs(sock->sk);
> +	int ret;
> +
> +	if (level != SOL_RDS) {
> +		ret = -ENOPROTOOPT;
> +		goto out;
> +	}
> +
> +	switch (optname) {
> +	case RDS_CANCEL_SENT_TO:
> +		ret = rds_cancel_sent_to(rs, optval, optlen);
> +		break;
> +	case RDS_GET_MR:
> +		if (enable_rdma)
> +			ret = rds_get_mr(rs, optval, optlen);
> +		else
> +			ret = -EOPNOTSUPP;
> +			break;
> +	case RDS_FREE_MR:
> +		if (enable_rdma)
> +			ret = rds_free_mr(rs, optval, optlen);
> +		else
> +			ret = -EOPNOTSUPP;
> +		break;
> +	case RDS_RECVERR:
> +		ret = rds_set_bool_option(&rs->rs_recverr, optval, optlen);
> +		break;
> +	case RDS_CONG_MONITOR:
> +		ret = rds_cong_monitor(rs, optval, optlen);
> +		break;
> +	default:
> +		ret = -ENOPROTOOPT;
> +	}
> +out:
> +	return ret;
> +}
> +
> +static int rds_getsockopt(struct socket *sock, int level, int optname,
> +			  char __user *optval, int __user *optlen)
> +{
> +	struct rds_sock *rs = rds_sk_to_rs(sock->sk);
> +	int ret = -ENOPROTOOPT, len;
> +
> +	if (level != SOL_RDS)
> +		goto out;
> +
> +	if (get_user(len, optlen)) {
> +		ret = -EFAULT;
> +		goto out;
> +	}
> +
> +	switch (optname) {
> +	case RDS_INFO_FIRST ... RDS_INFO_LAST:
> +		ret = rds_info_getsockopt(sock, optname, optval,
> +					  optlen);
> +		break;
> +
> +	case RDS_RECVERR:
> +		if (len < sizeof(int))
> +			ret = -EINVAL;
> +		else
> +		if (put_user(rs->rs_recverr, (int __user *) optval)
> +		 || put_user(sizeof(int), optlen))
> +			ret = -EFAULT;
> +		else
> +			ret = 0;
> +		break;
> +	default:
> +		break;
> +	}
> +
> +out:
> +	return ret;
> +
> +}
> +
> +static int rds_connect(struct socket *sock, struct sockaddr *uaddr,
> +		       int addr_len, int flags)
> +{
> +	struct sock *sk = sock->sk;
> +	struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
> +	struct rds_sock *rs = rds_sk_to_rs(sk);
> +	int ret = 0;
> +
> +	lock_sock(sk);
> +
> +	if (addr_len != sizeof(struct sockaddr_in)) {
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	if (sin->sin_family != AF_INET) {
> +		ret = -EAFNOSUPPORT;
> +		goto out;
> +	}
> +
> +	if (sin->sin_addr.s_addr == htonl(INADDR_ANY)) {
> +		ret = -EDESTADDRREQ;
> +		goto out;
> +	}
> +
> +	rs->rs_conn_addr = sin->sin_addr.s_addr;
> +	rs->rs_conn_port = sin->sin_port;
> +
> +out:
> +	release_sock(sk);
> +	return ret;
> +}
> +
> +#ifdef KERNEL_HAS_PROTO_REGISTER
> +static struct proto rds_proto = {
> +	.name	  = "RDS",
> +	.owner	  = THIS_MODULE,
> +	.obj_size = sizeof(struct rds_sock),
> +};
> +#endif /* KERNEL_HAS_PROTO_REGISTER */
> +
> +static struct proto_ops rds_proto_ops = {
> +	.family =	AF_RDS,
> +	.owner =	THIS_MODULE,
> +	.release =	rds_release,
> +	.bind =		rds_bind,
> +	.connect =	rds_connect,
> +	.socketpair =	sock_no_socketpair,
> +	.accept =	sock_no_accept,
> +	.getname =	rds_getname,
> +	.poll =		rds_poll,
> +	.ioctl =	rds_ioctl,
> +	.listen =	sock_no_listen,
> +	.shutdown =	sock_no_shutdown,
> +	.setsockopt =	rds_setsockopt,
> +	.getsockopt =	rds_getsockopt,
> +	.sendmsg =	rds_sendmsg,
> +	.recvmsg =	rds_recvmsg,
> +	.mmap =		sock_no_mmap,
> +	.sendpage =	sock_no_sendpage,
> +};
> +
> +#ifndef KERNEL_HAS_PROTO_REGISTER
> +static struct sock *sk_alloc_compat(int pf, gfp_t gfp, struct proto *prot,
> +				    int zero_it)
> +{
> +	struct rds_sock *rs;
> +
> +	sk = sk_alloc(pf, gfp, prot, zero_it);
> +	if (sk == NULL)
> +		return NULL;
> +
> +	rs = kcalloc(1, sizeof(struct rds_sock), GFP_ATOMIC);
> +	if (rs == NULL) {
> +		sk_free(sk);
> +		return NULL;
> +	}
> +
> +	/* sock_def_destruct frees this for us */
> +	sk->sk_protinfo = rs;
> +	rs->rs_sk = sk;
> +
> +	return sk;
> +}
> +
> +#undef sk_alloc
> +#define sk_alloc sk_alloc_compat
> +#endif /* KERNEL_HAS_PROTO_REGISTER */
> +
> +static int __rds_create(struct socket *sock, struct sock *sk, int protocol)
> +{
> +	unsigned long flags;
> +	struct rds_sock *rs;
> +
> +	sock_init_data(sock, sk);
> +#ifndef KERNEL_HAS_PROTO_REGISTER
> +	/* Can this be moved to sk_alloc_compat? */
> +	sk_set_owner(sk, THIS_MODULE);
> +#endif /* KERNEL_HAS_PROTO_REGISTER */
> +	sock->ops		= &rds_proto_ops;
> +	sk->sk_protocol		= protocol;
> +
> +	rs = rds_sk_to_rs(sk);
> +	spin_lock_init(&rs->rs_lock);
> +	rwlock_init(&rs->rs_recv_lock);
> +	INIT_LIST_HEAD(&rs->rs_send_queue);
> +	INIT_LIST_HEAD(&rs->rs_recv_queue);
> +	INIT_LIST_HEAD(&rs->rs_notify_queue);
> +	INIT_LIST_HEAD(&rs->rs_cong_list);
> +	spin_lock_init(&rs->rs_rdma_lock);
> +	rs->rs_rdma_keys = RB_ROOT;
> +
> +	spin_lock_irqsave(&rds_sock_lock, flags);
> +	list_add_tail(&rs->rs_item, &rds_sock_list);
> +	rds_sock_count++;
> +	spin_unlock_irqrestore(&rds_sock_lock, flags);
> +
> +	return 0;
> +}
> +
> +#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24)
> +static int rds_create(struct socket *sock, int protocol)
> +{
> +	struct sock *sk;
> +
> +	if (sock->type != SOCK_SEQPACKET || protocol)
> +		return -ESOCKTNOSUPPORT;
> +
> +	sk = sk_alloc(AF_RDS, GFP_ATOMIC, &rds_proto, 1);
> +	if (sk == NULL)
> +		return -ENOMEM;
> +
> +	return __rds_create(sock, sk, protocol);
> +}
> +#else
> +static int rds_create(struct net *net, struct socket *sock, int protocol)
> +{
> +	struct sock *sk;
> +
> +	if (sock->type != SOCK_SEQPACKET || protocol)
> +		return -ESOCKTNOSUPPORT;
> +
> +	sk = sk_alloc(net, AF_RDS, GFP_ATOMIC, &rds_proto);
> +	if (!sk)
> +		return -ENOMEM;
> +
> +	return __rds_create(sock, sk, protocol);
> +}
> +#endif
> +
> +void rds_sock_addref(struct rds_sock *rs)
> +{
> +	sock_hold(rds_rs_to_sk(rs));
> +}
> +
> +void rds_sock_put(struct rds_sock *rs)
> +{
> +	sock_put(rds_rs_to_sk(rs));
> +}
> +
> +static struct net_proto_family rds_family_ops = {
> +	.family =	AF_RDS,
> +	.create =	rds_create,
> +	.owner	=	THIS_MODULE,
> +};
> +
> +static void rds_sock_inc_info(struct socket *sock, unsigned int len,
> +			      struct rds_info_iterator *iter,
> +			      struct rds_info_lengths *lens)
> +{
> +	struct rds_sock *rs;
> +	struct sock *sk;
> +	struct rds_incoming *inc;
> +	unsigned long flags;
> +	unsigned int total = 0;
> +
> +	len /= sizeof(struct rds_info_message);
> +
> +	spin_lock_irqsave(&rds_sock_lock, flags);
> +
> +	list_for_each_entry(rs, &rds_sock_list, rs_item) {
> +		sk = rds_rs_to_sk(rs);
> +		read_lock(&rs->rs_recv_lock);
> +
> +		/* XXX too lazy to maintain counts.. */
> +		list_for_each_entry(inc, &rs->rs_recv_queue, i_item) {
> +			total++;
> +			if (total <= len)
> +				rds_inc_info_copy(inc, iter, inc->i_saddr,
> +						  rs->rs_bound_addr, 1);
> +		}
> +
> +		read_unlock(&rs->rs_recv_lock);
> +	}
> +
> +	spin_unlock_irqrestore(&rds_sock_lock, flags);
> +
> +	lens->nr = total;
> +	lens->each = sizeof(struct rds_info_message);
> +}
> +
> +static void rds_sock_info(struct socket *sock, unsigned int len,
> +			  struct rds_info_iterator *iter,
> +			  struct rds_info_lengths *lens)
> +{
> +	struct rds_info_socket sinfo;
> +	struct rds_sock *rs;
> +	unsigned long flags;
> +
> +	len /= sizeof(struct rds_info_socket);
> +
> +	spin_lock_irqsave(&rds_sock_lock, flags);
> +
> +	if (len < rds_sock_count)
> +		goto out;
> +
> +	list_for_each_entry(rs, &rds_sock_list, rs_item) {
> +		sinfo.sndbuf = rds_sk_sndbuf(rs);
> +		sinfo.rcvbuf = rds_sk_rcvbuf(rs);
> +		sinfo.bound_addr = rs->rs_bound_addr;
> +		sinfo.connected_addr = rs->rs_conn_addr;
> +		sinfo.bound_port = rs->rs_bound_port;
> +		sinfo.connected_port = rs->rs_conn_port;
> +		sinfo.inum = sock_i_ino(rds_rs_to_sk(rs));
> +
> +		rds_info_copy(iter, &sinfo, sizeof(sinfo));
> +	}
> +
> +out:
> +	lens->nr = rds_sock_count;
> +	lens->each = sizeof(struct rds_info_socket);
> +
> +	spin_unlock_irqrestore(&rds_sock_lock, flags);
> +}
> +
> +/*
> + * The order is important here.
> + *
> + * rds_trans_stop_listening() is called before conn_exit so new connections
> + * don't hit while existing ones are being torn down.
> + *
> + * rds_conn_exit() is before rds_trans_exit() as rds_conn_exit() calls into the
> + * transports to free connections and incoming fragments as they're torn down.
> + */
> +static void __exit rds_exit(void)
> +{
> +	rds_ib_exit();
> +	sock_unregister(rds_family_ops.family);
> +#ifdef KERNEL_HAS_PROTO_REGISTER
> +	proto_unregister(&rds_proto);
> +#endif /* KERNEL_HAS_PROTO_REGISTER */
> +	rds_trans_stop_listening();
> +	rds_conn_exit();
> +	rds_cong_exit();
> +	rds_sysctl_exit();
> +	rds_threads_exit();
> +	rds_stats_exit();
> +	rds_page_exit();
> +	rds_info_deregister_func(RDS_INFO_SOCKETS, rds_sock_info);
> +	rds_info_deregister_func(RDS_INFO_RECV_MESSAGES, rds_sock_inc_info);
> +}
> +module_exit(rds_exit);
> +
> +static int __init rds_init(void)
> +{
> +	int ret;
> +
> +#ifndef KERNEL_HAS_NOT_DEFINED
> +	/* the strange ifdef above has scripts/makepatch.sh strip this out */
> +#if PF_RDS == 21
> +	printk(KERN_ERR "!!! This build of RDS is using PF 21 which is not "
> +	       "reserved\n");
> +	printk(KERN_ERR "!!! This is only suitable for testing, DO NOT "
> +	       "RELEASE THIS.\n");
> +	printk(KERN_ERR "!!! No, seriously.\n");
> +#endif
> +#endif /* KERNEL_HAS_NOT_DEFINED */

You don't want this ifdef crap in upstream

> +
> +	ret = rds_conn_init();
> +	if (ret)
> +		goto out;
> +	ret = rds_threads_init();
> +	if (ret)
> +		goto out_conn;
> +	ret = rds_sysctl_init();
> +	if (ret)
> +		goto out_threads;
> +	ret = rds_stats_init();
> +	if (ret)
> +		goto out_sysctl;
> +#ifdef KERNEL_HAS_PROTO_REGISTER
> +	ret = proto_register(&rds_proto, 1);
> +	if (ret)
> +		goto out_stats;
> +#endif /* KERNEL_HAS_PROTO_REGISTER */
> +	ret = sock_register(&rds_family_ops);
> +	if (ret)
> +		goto out_proto;
> +
> +	rds_info_register_func(RDS_INFO_SOCKETS, rds_sock_info);
> +	rds_info_register_func(RDS_INFO_RECV_MESSAGES, rds_sock_inc_info);
> +
> +	ret = rds_ib_init();
> +	if (ret)
> +		goto out_sock;
> +	goto out;
> +
> +out_sock:
> +	sock_unregister(rds_family_ops.family);
> +out_proto:
> +#ifdef KERNEL_HAS_PROTO_REGISTER
> +	proto_unregister(&rds_proto);
> +out_stats:
> +#endif /* KERNEL_HAS_PROTO_REGISTER */
> +	rds_stats_exit();
> +out_sysctl:
> +	rds_sysctl_exit();
> +out_threads:
> +	rds_threads_exit();
> +out_conn:
> +	rds_conn_exit();
> +	rds_cong_exit();
> +	rds_page_exit();
> +out:
> +	return ret;
> +}
> +module_init(rds_init);
> +
> +#define DRV_VERSION     "4.0"
> +#define DRV_RELDATE     "July 28, 2008"
> +
> +MODULE_AUTHOR("Zach Brown");
> +MODULE_AUTHOR("Olaf Kirch");
> +MODULE_DESCRIPTION("RDS: Reliable Datagram Sockets"
> +		   " v" DRV_VERSION " (" DRV_RELDATE ")");
> +MODULE_VERSION(DRV_VERSION);
> +MODULE_LICENSE("Dual BSD/GPL");
> +MODULE_ALIAS_NETPROTO(PF_RDS);