Merge branch 'l2tp-remove-unused-code'

Guillaume Nault says:

====================
l2tp: remove unused code

Patch #1 removes the ref/deref mechanism that was originally used to
prevent ppp pseudowires from dropping their sockets. This mechanism
was error prone and isn't used anymore.

Patch #2 removes some module specific refcount debugging.
Patches #3 and #4 take care of some dead code.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2017-11-01 10:57:24 +09:00
commit ee7d163196
8 changed files with 27 additions and 116 deletions

View file

@ -100,8 +100,6 @@ struct l2tp_skb_cb {
#define L2TP_SKB_CB(skb) ((struct l2tp_skb_cb *) &skb->cb[sizeof(struct inet_skb_parm)])
static atomic_t l2tp_tunnel_count;
static atomic_t l2tp_session_count;
static struct workqueue_struct *l2tp_wq;
/* per-net private data for this module */
@ -216,12 +214,10 @@ struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id)
}
EXPORT_SYMBOL_GPL(l2tp_tunnel_get);
/* Lookup a session. A new reference is held on the returned session.
* Optionally calls session->ref() too if do_ref is true.
*/
/* Lookup a session. A new reference is held on the returned session. */
struct l2tp_session *l2tp_session_get(const struct net *net,
struct l2tp_tunnel *tunnel,
u32 session_id, bool do_ref)
u32 session_id)
{
struct hlist_head *session_list;
struct l2tp_session *session;
@ -235,8 +231,6 @@ struct l2tp_session *l2tp_session_get(const struct net *net,
hlist_for_each_entry_rcu(session, session_list, global_hlist) {
if (session->session_id == session_id) {
l2tp_session_inc_refcount(session);
if (do_ref && session->ref)
session->ref(session);
rcu_read_unlock_bh();
return session;
@ -252,8 +246,6 @@ struct l2tp_session *l2tp_session_get(const struct net *net,
hlist_for_each_entry(session, session_list, hlist) {
if (session->session_id == session_id) {
l2tp_session_inc_refcount(session);
if (do_ref && session->ref)
session->ref(session);
read_unlock_bh(&tunnel->hlist_lock);
return session;
@ -265,8 +257,7 @@ struct l2tp_session *l2tp_session_get(const struct net *net,
}
EXPORT_SYMBOL_GPL(l2tp_session_get);
struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth,
bool do_ref)
struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth)
{
int hash;
struct l2tp_session *session;
@ -277,8 +268,6 @@ struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth,
hlist_for_each_entry(session, &tunnel->session_hlist[hash], hlist) {
if (++count > nth) {
l2tp_session_inc_refcount(session);
if (do_ref && session->ref)
session->ref(session);
read_unlock_bh(&tunnel->hlist_lock);
return session;
}
@ -295,8 +284,7 @@ EXPORT_SYMBOL_GPL(l2tp_session_get_nth);
* This is very inefficient but is only used by management interfaces.
*/
struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net,
const char *ifname,
bool do_ref)
const char *ifname)
{
struct l2tp_net *pn = l2tp_pernet(net);
int hash;
@ -307,8 +295,6 @@ struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net,
hlist_for_each_entry_rcu(session, &pn->l2tp_session_hlist[hash], global_hlist) {
if (!strcmp(session->ifname, ifname)) {
l2tp_session_inc_refcount(session);
if (do_ref && session->ref)
session->ref(session);
rcu_read_unlock_bh();
return session;
@ -371,10 +357,6 @@ int l2tp_session_register(struct l2tp_session *session,
hlist_add_head(&session->hlist, head);
write_unlock_bh(&tunnel->hlist_lock);
/* Ignore management session in session count value */
if (session->session_id != 0)
atomic_inc(&l2tp_session_count);
return 0;
err_tlock_pnlock:
@ -489,9 +471,6 @@ static void l2tp_recv_dequeue_skb(struct l2tp_session *session, struct sk_buff *
(*session->recv_skb)(session, skb, L2TP_SKB_CB(skb)->length);
else
kfree_skb(skb);
if (session->deref)
(*session->deref)(session);
}
/* Dequeue skbs from the session's reorder_q, subject to packet order.
@ -520,8 +499,6 @@ static void l2tp_recv_dequeue(struct l2tp_session *session)
session->reorder_skip = 1;
__skb_unlink(skb, &session->reorder_q);
kfree_skb(skb);
if (session->deref)
(*session->deref)(session);
continue;
}
@ -694,9 +671,6 @@ static int l2tp_recv_data_seq(struct l2tp_session *session, struct sk_buff *skb)
* a data (not control) frame before coming here. Fields up to the
* session-id have already been parsed and ptr points to the data
* after the session-id.
*
* session->ref() must have been called prior to l2tp_recv_common().
* session->deref() will be called automatically after skb is processed.
*/
void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
unsigned char *ptr, unsigned char *optr, u16 hdrflags,
@ -863,9 +837,6 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
discard:
atomic_long_inc(&session->stats.rx_errors);
kfree_skb(skb);
if (session->deref)
(*session->deref)(session);
}
EXPORT_SYMBOL(l2tp_recv_common);
@ -879,8 +850,6 @@ int l2tp_session_queue_purge(struct l2tp_session *session)
while ((skb = skb_dequeue(&session->reorder_q))) {
atomic_long_inc(&session->stats.rx_errors);
kfree_skb(skb);
if (session->deref)
(*session->deref)(session);
}
return 0;
}
@ -972,13 +941,10 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb,
}
/* Find the session context */
session = l2tp_session_get(tunnel->l2tp_net, tunnel, session_id, true);
session = l2tp_session_get(tunnel->l2tp_net, tunnel, session_id);
if (!session || !session->recv_skb) {
if (session) {
if (session->deref)
session->deref(session);
if (session)
l2tp_session_dec_refcount(session);
}
/* Not found? Pass to userspace to deal with */
l2tp_info(tunnel, L2TP_MSG_DATA,
@ -1279,7 +1245,6 @@ static void l2tp_tunnel_destruct(struct sock *sk)
spin_lock_bh(&pn->l2tp_tunnel_list_lock);
list_del_rcu(&tunnel->list);
spin_unlock_bh(&pn->l2tp_tunnel_list_lock);
atomic_dec(&l2tp_tunnel_count);
l2tp_tunnel_closeall(tunnel);
@ -1322,9 +1287,6 @@ void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel)
if (test_and_set_bit(0, &session->dead))
goto again;
if (session->ref != NULL)
(*session->ref)(session);
write_unlock_bh(&tunnel->hlist_lock);
__l2tp_session_unhash(session);
@ -1333,9 +1295,6 @@ void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel)
if (session->session_close != NULL)
(*session->session_close)(session);
if (session->deref != NULL)
(*session->deref)(session);
l2tp_session_dec_refcount(session);
write_lock_bh(&tunnel->hlist_lock);
@ -1666,7 +1625,6 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32
/* Add tunnel to our list */
INIT_LIST_HEAD(&tunnel->list);
atomic_inc(&l2tp_tunnel_count);
/* Bump the reference count. The tunnel context is deleted
* only when this drops to zero. Must be done before list insertion
@ -1712,8 +1670,6 @@ void l2tp_session_free(struct l2tp_session *session)
if (tunnel) {
BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
if (session->session_id != 0)
atomic_dec(&l2tp_session_count);
sock_put(tunnel->sock);
session->tunnel = NULL;
l2tp_tunnel_dec_refcount(tunnel);
@ -1759,15 +1715,13 @@ int l2tp_session_delete(struct l2tp_session *session)
if (test_and_set_bit(0, &session->dead))
return 0;
if (session->ref)
(*session->ref)(session);
__l2tp_session_unhash(session);
l2tp_session_queue_purge(session);
if (session->session_close != NULL)
(*session->session_close)(session);
if (session->deref)
(*session->deref)(session);
l2tp_session_dec_refcount(session);
return 0;
}
EXPORT_SYMBOL_GPL(l2tp_session_delete);

View file

@ -129,8 +129,6 @@ struct l2tp_session {
int (*build_header)(struct l2tp_session *session, void *buf);
void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len);
void (*session_close)(struct l2tp_session *session);
void (*ref)(struct l2tp_session *session);
void (*deref)(struct l2tp_session *session);
#if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
void (*show)(struct seq_file *m, void *priv);
#endif
@ -245,12 +243,10 @@ struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id);
struct l2tp_session *l2tp_session_get(const struct net *net,
struct l2tp_tunnel *tunnel,
u32 session_id, bool do_ref);
struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth,
bool do_ref);
u32 session_id);
struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth);
struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net,
const char *ifname,
bool do_ref);
const char *ifname);
struct l2tp_tunnel *l2tp_tunnel_find(const struct net *net, u32 tunnel_id);
struct l2tp_tunnel *l2tp_tunnel_find_nth(const struct net *net, int nth);
@ -298,37 +294,17 @@ static inline void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel)
/* Session reference counts. Incremented when code obtains a reference
* to a session.
*/
static inline void l2tp_session_inc_refcount_1(struct l2tp_session *session)
static inline void l2tp_session_inc_refcount(struct l2tp_session *session)
{
refcount_inc(&session->ref_count);
}
static inline void l2tp_session_dec_refcount_1(struct l2tp_session *session)
static inline void l2tp_session_dec_refcount(struct l2tp_session *session)
{
if (refcount_dec_and_test(&session->ref_count))
l2tp_session_free(session);
}
#ifdef L2TP_REFCNT_DEBUG
#define l2tp_session_inc_refcount(_s) \
do { \
pr_debug("l2tp_session_inc_refcount: %s:%d %s: cnt=%d\n", \
__func__, __LINE__, (_s)->name, \
refcount_read(&_s->ref_count)); \
l2tp_session_inc_refcount_1(_s); \
} while (0)
#define l2tp_session_dec_refcount(_s) \
do { \
pr_debug("l2tp_session_dec_refcount: %s:%d %s: cnt=%d\n", \
__func__, __LINE__, (_s)->name, \
refcount_read(&_s->ref_count)); \
l2tp_session_dec_refcount_1(_s); \
} while (0)
#else
#define l2tp_session_inc_refcount(s) l2tp_session_inc_refcount_1(s)
#define l2tp_session_dec_refcount(s) l2tp_session_dec_refcount_1(s)
#endif
#define l2tp_printk(ptr, type, func, fmt, ...) \
do { \
if (((ptr)->debug) & (type)) \

View file

@ -53,7 +53,7 @@ static void l2tp_dfs_next_tunnel(struct l2tp_dfs_seq_data *pd)
static void l2tp_dfs_next_session(struct l2tp_dfs_seq_data *pd)
{
pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx, true);
pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx);
pd->session_idx++;
if (pd->session == NULL) {
@ -241,8 +241,6 @@ static int l2tp_dfs_seq_show(struct seq_file *m, void *v)
l2tp_dfs_seq_tunnel_show(m, pd->tunnel);
} else {
l2tp_dfs_seq_session_show(m, pd->session);
if (pd->session->deref)
pd->session->deref(pd->session);
l2tp_session_dec_refcount(pd->session);
}

View file

@ -41,7 +41,6 @@
/* via netdev_priv() */
struct l2tp_eth {
struct net_device *dev;
struct sock *tunnel_sock;
struct l2tp_session *session;
atomic_long_t tx_bytes;
@ -60,9 +59,6 @@ struct l2tp_eth_sess {
static int l2tp_eth_dev_init(struct net_device *dev)
{
struct l2tp_eth *priv = netdev_priv(dev);
priv->dev = dev;
eth_hw_addr_random(dev);
eth_broadcast_addr(dev->broadcast);
netdev_lockdep_set_classes(dev);
@ -315,7 +311,6 @@ static int l2tp_eth_create(struct net *net, struct l2tp_tunnel *tunnel,
l2tp_eth_adjust_mtu(tunnel, session, dev);
priv = netdev_priv(dev);
priv->dev = dev;
priv->session = session;
priv->tunnel_sock = tunnel->sock;

View file

@ -143,7 +143,7 @@ static int l2tp_ip_recv(struct sk_buff *skb)
}
/* Ok, this is a data packet. Lookup the session. */
session = l2tp_session_get(net, NULL, session_id, true);
session = l2tp_session_get(net, NULL, session_id);
if (!session)
goto discard;
@ -205,8 +205,6 @@ static int l2tp_ip_recv(struct sk_buff *skb)
return sk_receive_skb(sk, skb, 1);
discard_sess:
if (session->deref)
session->deref(session);
l2tp_session_dec_refcount(session);
goto discard;

View file

@ -156,7 +156,7 @@ static int l2tp_ip6_recv(struct sk_buff *skb)
}
/* Ok, this is a data packet. Lookup the session. */
session = l2tp_session_get(net, NULL, session_id, true);
session = l2tp_session_get(net, NULL, session_id);
if (!session)
goto discard;
@ -219,8 +219,6 @@ static int l2tp_ip6_recv(struct sk_buff *skb)
return sk_receive_skb(sk, skb, 1);
discard_sess:
if (session->deref)
session->deref(session);
l2tp_session_dec_refcount(session);
goto discard;

View file

@ -48,8 +48,7 @@ static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq,
/* Accessed under genl lock */
static const struct l2tp_nl_cmd_ops *l2tp_nl_cmd_ops[__L2TP_PWTYPE_MAX];
static struct l2tp_session *l2tp_nl_session_get(struct genl_info *info,
bool do_ref)
static struct l2tp_session *l2tp_nl_session_get(struct genl_info *info)
{
u32 tunnel_id;
u32 session_id;
@ -60,15 +59,14 @@ static struct l2tp_session *l2tp_nl_session_get(struct genl_info *info,
if (info->attrs[L2TP_ATTR_IFNAME]) {
ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
session = l2tp_session_get_by_ifname(net, ifname, do_ref);
session = l2tp_session_get_by_ifname(net, ifname);
} else if ((info->attrs[L2TP_ATTR_SESSION_ID]) &&
(info->attrs[L2TP_ATTR_CONN_ID])) {
tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
tunnel = l2tp_tunnel_get(net, tunnel_id);
if (tunnel) {
session = l2tp_session_get(net, tunnel, session_id,
do_ref);
session = l2tp_session_get(net, tunnel, session_id);
l2tp_tunnel_dec_refcount(tunnel);
}
}
@ -649,7 +647,7 @@ static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *inf
&cfg);
if (ret >= 0) {
session = l2tp_session_get(net, tunnel, session_id, false);
session = l2tp_session_get(net, tunnel, session_id);
if (session) {
ret = l2tp_session_notify(&l2tp_nl_family, info, session,
L2TP_CMD_SESSION_CREATE);
@ -669,7 +667,7 @@ static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *inf
struct l2tp_session *session;
u16 pw_type;
session = l2tp_nl_session_get(info, true);
session = l2tp_nl_session_get(info);
if (session == NULL) {
ret = -ENODEV;
goto out;
@ -683,8 +681,6 @@ static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *inf
if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
if (session->deref)
session->deref(session);
l2tp_session_dec_refcount(session);
out:
@ -696,7 +692,7 @@ static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *inf
int ret = 0;
struct l2tp_session *session;
session = l2tp_nl_session_get(info, false);
session = l2tp_nl_session_get(info);
if (session == NULL) {
ret = -ENODEV;
goto out;
@ -828,7 +824,7 @@ static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
struct sk_buff *msg;
int ret;
session = l2tp_nl_session_get(info, false);
session = l2tp_nl_session_get(info);
if (session == NULL) {
ret = -ENODEV;
goto err;
@ -874,7 +870,7 @@ static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback
goto out;
}
session = l2tp_session_get_nth(tunnel, si, false);
session = l2tp_session_get_nth(tunnel, si);
if (session == NULL) {
ti++;
tunnel = NULL;

View file

@ -742,7 +742,7 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
if (tunnel->peer_tunnel_id == 0)
tunnel->peer_tunnel_id = peer_tunnel_id;
session = l2tp_session_get(sock_net(sk), tunnel, session_id, false);
session = l2tp_session_get(sock_net(sk), tunnel, session_id);
if (session) {
drop_refcnt = true;
ps = l2tp_session_priv(session);
@ -1193,13 +1193,11 @@ static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel,
/* resend to session ioctl handler */
struct l2tp_session *session =
l2tp_session_get(sock_net(sk), tunnel,
stats.session_id, true);
stats.session_id);
if (session) {
err = pppol2tp_session_ioctl(session, cmd,
arg);
if (session->deref)
session->deref(session);
l2tp_session_dec_refcount(session);
} else {
err = -EBADR;
@ -1615,7 +1613,7 @@ static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd)
static void pppol2tp_next_session(struct net *net, struct pppol2tp_seq_data *pd)
{
pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx, true);
pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx);
pd->session_idx++;
if (pd->session == NULL) {
@ -1758,8 +1756,6 @@ static int pppol2tp_seq_show(struct seq_file *m, void *v)
pppol2tp_seq_tunnel_show(m, pd->tunnel);
} else {
pppol2tp_seq_session_show(m, pd->session);
if (pd->session->deref)
pd->session->deref(pd->session);
l2tp_session_dec_refcount(pd->session);
}