Merge branch 'possible_net_t'

Eric W. Biederman says:

====================
Introduce possible_net_t

The current usage of write_pnet and read_pnet is a little laborious and
error prone as you only notice if you failed to include them if are
compiling with network namespaces enabled.

possible_net_t remedies that by using a type that is 0 bytes when
network namespaces are disabled and can only be read and written to with
read_pnet and write_pnet.

Aka less work and safer for the same effect.

I kill hold_net and release_net first as are they are haven't been used
since 2008 and are noise at the points where write_pnet and read_pnet
are used.

I have folded in Eric Dumazets suggestions to improve the killing of
hold_net and release net.  And respon.  I had to respin anyway as
there was enough changes elsewhere in the tree the previous version
of these patches did not quite apply cleanly.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2015-03-12 14:39:44 -04:00
commit 20453d88cc
27 changed files with 55 additions and 161 deletions

View File

@ -1721,9 +1721,7 @@ struct net_device {
struct netpoll_info __rcu *npinfo;
#endif
#ifdef CONFIG_NET_NS
struct net *nd_net;
#endif
possible_net_t nd_net;
/* mid-layer private */
union {
@ -1863,10 +1861,7 @@ struct net *dev_net(const struct net_device *dev)
static inline
void dev_net_set(struct net_device *dev, struct net *net)
{
#ifdef CONFIG_NET_NS
release_net(dev->nd_net);
dev->nd_net = hold_net(net);
#endif
write_pnet(&dev->nd_net, net);
}
static inline bool netdev_uses_dsa(struct net_device *dev)

View File

@ -3183,10 +3183,8 @@ struct wiphy {
const struct ieee80211_ht_cap *ht_capa_mod_mask;
const struct ieee80211_vht_cap *vht_capa_mod_mask;
#ifdef CONFIG_NET_NS
/* the network namespace this phy lives in currently */
struct net *_net;
#endif
possible_net_t _net;
#ifdef CONFIG_CFG80211_WEXT
const struct iw_handler_def *wext;

View File

@ -95,17 +95,10 @@ static inline void fib_rule_get(struct fib_rule *rule)
atomic_inc(&rule->refcnt);
}
static inline void fib_rule_put_rcu(struct rcu_head *head)
{
struct fib_rule *rule = container_of(head, struct fib_rule, rcu);
release_net(rule->fr_net);
kfree(rule);
}
static inline void fib_rule_put(struct fib_rule *rule)
{
if (atomic_dec_and_test(&rule->refcnt))
call_rcu(&rule->rcu, fib_rule_put_rcu);
kfree_rcu(rule, rcu);
}
static inline u32 frh_get_table(struct fib_rule_hdr *frh, struct nlattr **nla)

View File

@ -92,9 +92,7 @@ struct genl_info {
struct genlmsghdr * genlhdr;
void * userhdr;
struct nlattr ** attrs;
#ifdef CONFIG_NET_NS
struct net * _net;
#endif
possible_net_t _net;
void * user_ptr[2];
struct sock * dst_sk;
};

View File

@ -76,9 +76,7 @@ struct inet_ehash_bucket {
* ports are created in O(1) time? I thought so. ;-) -DaveM
*/
struct inet_bind_bucket {
#ifdef CONFIG_NET_NS
struct net *ib_net;
#endif
possible_net_t ib_net;
unsigned short port;
signed char fastreuse;
signed char fastreuseport;

View File

@ -47,13 +47,13 @@ static inline struct net *skb_net(const struct sk_buff *skb)
* Start with the most likely hit
* End with BUG
*/
if (likely(skb->dev && skb->dev->nd_net))
if (likely(skb->dev && dev_net(skb->dev)))
return dev_net(skb->dev);
if (skb_dst(skb) && skb_dst(skb)->dev)
return dev_net(skb_dst(skb)->dev);
WARN(skb->sk, "Maybe skb_sknet should be used in %s() at line:%d\n",
__func__, __LINE__);
if (likely(skb->sk && skb->sk->sk_net))
if (likely(skb->sk && sock_net(skb->sk)))
return sock_net(skb->sk);
pr_err("There is no net ptr to find in the skb in %s() line:%d\n",
__func__, __LINE__);
@ -71,11 +71,11 @@ static inline struct net *skb_sknet(const struct sk_buff *skb)
#ifdef CONFIG_NET_NS
#ifdef CONFIG_IP_VS_DEBUG
/* Start with the most likely hit */
if (likely(skb->sk && skb->sk->sk_net))
if (likely(skb->sk && sock_net(skb->sk)))
return sock_net(skb->sk);
WARN(skb->dev, "Maybe skb_net should be used instead in %s() line:%d\n",
__func__, __LINE__);
if (likely(skb->dev && skb->dev->nd_net))
if (likely(skb->dev && dev_net(skb->dev)))
return dev_net(skb->dev);
pr_err("There is no net ptr to find in the skb in %s() line:%d\n",
__func__, __LINE__);

View File

@ -65,9 +65,7 @@ enum {
};
struct neigh_parms {
#ifdef CONFIG_NET_NS
struct net *net;
#endif
possible_net_t net;
struct net_device *dev;
struct list_head list;
int (*neigh_setup)(struct neighbour *);
@ -167,9 +165,7 @@ struct neigh_ops {
struct pneigh_entry {
struct pneigh_entry *next;
#ifdef CONFIG_NET_NS
struct net *net;
#endif
possible_net_t net;
struct net_device *dev;
u8 flags;
u8 key[0];

View File

@ -49,11 +49,6 @@ struct net {
atomic_t count; /* To decided when the network
* namespace should be shut down.
*/
#ifdef NETNS_REFCNT_DEBUG
atomic_t use_count; /* To track references we
* destroy on demand
*/
#endif
spinlock_t rules_mod_lock;
atomic64_t cookie_gen;
@ -236,48 +231,27 @@ int net_eq(const struct net *net1, const struct net *net2)
#endif
#ifdef NETNS_REFCNT_DEBUG
static inline struct net *hold_net(struct net *net)
{
if (net)
atomic_inc(&net->use_count);
return net;
}
static inline void release_net(struct net *net)
{
if (net)
atomic_dec(&net->use_count);
}
#else
static inline struct net *hold_net(struct net *net)
{
return net;
}
static inline void release_net(struct net *net)
{
}
#endif
typedef struct {
#ifdef CONFIG_NET_NS
static inline void write_pnet(struct net **pnet, struct net *net)
{
*pnet = net;
}
static inline struct net *read_pnet(struct net * const *pnet)
{
return *pnet;
}
#else
#define write_pnet(pnet, net) do { (void)(net);} while (0)
#define read_pnet(pnet) (&init_net)
struct net *net;
#endif
} possible_net_t;
static inline void write_pnet(possible_net_t *pnet, struct net *net)
{
#ifdef CONFIG_NET_NS
pnet->net = net;
#endif
}
static inline struct net *read_pnet(const possible_net_t *pnet)
{
#ifdef CONFIG_NET_NS
return pnet->net;
#else
return &init_net;
#endif
}
#define for_each_net(VAR) \
list_for_each_entry(VAR, &net_namespace_list, list)

View File

@ -95,9 +95,8 @@ struct nf_conn {
/* Timer function; drops refcnt when it goes off. */
struct timer_list timeout;
#ifdef CONFIG_NET_NS
struct net *ct_net;
#endif
possible_net_t ct_net;
/* all members below initialized via memset */
u8 __nfct_init_offset[0];

View File

@ -190,9 +190,7 @@ struct sock_common {
struct hlist_nulls_node skc_portaddr_node;
};
struct proto *skc_prot;
#ifdef CONFIG_NET_NS
struct net *skc_net;
#endif
possible_net_t skc_net;
#if IS_ENABLED(CONFIG_IPV6)
struct in6_addr skc_v6_daddr;
@ -2204,7 +2202,7 @@ static inline void sk_change_net(struct sock *sk, struct net *net)
if (!net_eq(current_net, net)) {
put_net(current_net);
sock_net_set(sk, hold_net(net));
sock_net_set(sk, net);
}
}

View File

@ -126,9 +126,7 @@ struct xfrm_state_walk {
/* Full description of state of transformer. */
struct xfrm_state {
#ifdef CONFIG_NET_NS
struct net *xs_net;
#endif
possible_net_t xs_net;
union {
struct hlist_node gclist;
struct hlist_node bydst;
@ -522,9 +520,7 @@ struct xfrm_policy_queue {
};
struct xfrm_policy {
#ifdef CONFIG_NET_NS
struct net *xp_net;
#endif
possible_net_t xp_net;
struct hlist_node bydst;
struct hlist_node byidx;

View File

@ -940,7 +940,7 @@ p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
sin_server.sin_family = AF_INET;
sin_server.sin_addr.s_addr = in_aton(addr);
sin_server.sin_port = htons(opts.port);
err = __sock_create(read_pnet(&current->nsproxy->net_ns), PF_INET,
err = __sock_create(current->nsproxy->net_ns, PF_INET,
SOCK_STREAM, IPPROTO_TCP, &csocket, 1);
if (err) {
pr_err("%s (%d): problem creating socket\n",
@ -988,7 +988,7 @@ p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
sun_server.sun_family = PF_UNIX;
strcpy(sun_server.sun_path, addr);
err = __sock_create(read_pnet(&current->nsproxy->net_ns), PF_UNIX,
err = __sock_create(current->nsproxy->net_ns, PF_UNIX,
SOCK_STREAM, 0, &csocket, 1);
if (err < 0) {
pr_err("%s (%d): problem creating socket\n",

View File

@ -6841,8 +6841,6 @@ void free_netdev(struct net_device *dev)
{
struct napi_struct *p, *n;
release_net(dev_net(dev));
netif_free_tx_queues(dev);
#ifdef CONFIG_SYSFS
kvfree(dev->_rx);

View File

@ -31,7 +31,7 @@ int fib_default_rule_add(struct fib_rules_ops *ops,
r->pref = pref;
r->table = table;
r->flags = flags;
r->fr_net = hold_net(ops->fro_net);
r->fr_net = ops->fro_net;
r->suppress_prefixlen = -1;
r->suppress_ifgroup = -1;
@ -116,7 +116,6 @@ static int __fib_rules_register(struct fib_rules_ops *ops)
if (ops->family == o->family)
goto errout;
hold_net(net);
list_add_tail_rcu(&ops->list, &net->rules_ops);
err = 0;
errout:
@ -160,15 +159,6 @@ static void fib_rules_cleanup_ops(struct fib_rules_ops *ops)
}
}
static void fib_rules_put_rcu(struct rcu_head *head)
{
struct fib_rules_ops *ops = container_of(head, struct fib_rules_ops, rcu);
struct net *net = ops->fro_net;
release_net(net);
kfree(ops);
}
void fib_rules_unregister(struct fib_rules_ops *ops)
{
struct net *net = ops->fro_net;
@ -178,7 +168,7 @@ void fib_rules_unregister(struct fib_rules_ops *ops)
fib_rules_cleanup_ops(ops);
spin_unlock(&net->rules_mod_lock);
call_rcu(&ops->rcu, fib_rules_put_rcu);
kfree_rcu(ops, rcu);
}
EXPORT_SYMBOL_GPL(fib_rules_unregister);
@ -303,7 +293,7 @@ static int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh)
err = -ENOMEM;
goto errout;
}
rule->fr_net = hold_net(net);
rule->fr_net = net;
if (tb[FRA_PRIORITY])
rule->pref = nla_get_u32(tb[FRA_PRIORITY]);
@ -423,7 +413,6 @@ static int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh)
return 0;
errout_free:
release_net(rule->fr_net);
kfree(rule);
errout:
rules_ops_put(ops);

View File

@ -591,7 +591,7 @@ struct pneigh_entry * pneigh_lookup(struct neigh_table *tbl,
if (!n)
goto out;
write_pnet(&n->net, hold_net(net));
write_pnet(&n->net, net);
memcpy(n->key, pkey, key_len);
n->dev = dev;
if (dev)
@ -600,7 +600,6 @@ struct pneigh_entry * pneigh_lookup(struct neigh_table *tbl,
if (tbl->pconstructor && tbl->pconstructor(n)) {
if (dev)
dev_put(dev);
release_net(net);
kfree(n);
n = NULL;
goto out;
@ -634,7 +633,6 @@ int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *pkey,
tbl->pdestructor(n);
if (n->dev)
dev_put(n->dev);
release_net(pneigh_net(n));
kfree(n);
return 0;
}
@ -657,7 +655,6 @@ static int pneigh_ifdown(struct neigh_table *tbl, struct net_device *dev)
tbl->pdestructor(n);
if (n->dev)
dev_put(n->dev);
release_net(pneigh_net(n));
kfree(n);
continue;
}
@ -1428,11 +1425,10 @@ struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
neigh_rand_reach_time(NEIGH_VAR(p, BASE_REACHABLE_TIME));
dev_hold(dev);
p->dev = dev;
write_pnet(&p->net, hold_net(net));
write_pnet(&p->net, net);
p->sysctl_table = NULL;
if (ops->ndo_neigh_setup && ops->ndo_neigh_setup(dev, p)) {
release_net(net);
dev_put(dev);
kfree(p);
return NULL;
@ -1472,7 +1468,6 @@ EXPORT_SYMBOL(neigh_parms_release);
static void neigh_parms_destroy(struct neigh_parms *parms)
{
release_net(neigh_parms_net(parms));
kfree(parms);
}

View File

@ -236,10 +236,6 @@ static __net_init int setup_net(struct net *net, struct user_namespace *user_ns)
net->user_ns = user_ns;
idr_init(&net->netns_ids);
#ifdef NETNS_REFCNT_DEBUG
atomic_set(&net->use_count, 0);
#endif
list_for_each_entry(ops, &pernet_list, list) {
error = ops_init(ops, net);
if (error < 0)
@ -294,13 +290,6 @@ static struct net *net_alloc(void)
static void net_free(struct net *net)
{
#ifdef NETNS_REFCNT_DEBUG
if (unlikely(atomic_read(&net->use_count) != 0)) {
pr_emerg("network namespace not free! Usage: %d\n",
atomic_read(&net->use_count));
return;
}
#endif
kfree(rcu_access_pointer(net->gen));
kmem_cache_free(net_cachep, net);
}

View File

@ -1455,7 +1455,6 @@ void sk_release_kernel(struct sock *sk)
sock_hold(sk);
sock_release(sk->sk_socket);
release_net(sock_net(sk));
sock_net_set(sk, get_net(&init_net));
sock_put(sk);
}

View File

@ -213,7 +213,6 @@ static void free_fib_info_rcu(struct rcu_head *head)
rt_fibinfo_free(&nexthop_nh->nh_rth_input);
} endfor_nexthops(fi);
release_net(fi->fib_net);
if (fi->fib_metrics != (u32 *) dst_default_metrics)
kfree(fi->fib_metrics);
kfree(fi);
@ -814,7 +813,7 @@ struct fib_info *fib_create_info(struct fib_config *cfg)
} else
fi->fib_metrics = (u32 *) dst_default_metrics;
fi->fib_net = hold_net(net);
fi->fib_net = net;
fi->fib_protocol = cfg->fc_protocol;
fi->fib_scope = cfg->fc_scope;
fi->fib_flags = cfg->fc_flags;

View File

@ -61,7 +61,7 @@ struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep,
struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC);
if (tb != NULL) {
write_pnet(&tb->ib_net, hold_net(net));
write_pnet(&tb->ib_net, net);
tb->port = snum;
tb->fastreuse = 0;
tb->fastreuseport = 0;
@ -79,7 +79,6 @@ void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket
{
if (hlist_empty(&tb->owners)) {
__hlist_del(&tb->node);
release_net(ib_net(tb));
kmem_cache_free(cachep, tb);
}
}

View File

@ -98,7 +98,6 @@ void inet_twsk_free(struct inet_timewait_sock *tw)
#ifdef SOCK_REFCNT_DEBUG
pr_debug("%s timewait_sock %p released\n", tw->tw_prot->name, tw);
#endif
release_net(twsk_net(tw));
kmem_cache_free(tw->tw_prot->twsk_prot->twsk_slab, tw);
module_put(owner);
}
@ -196,7 +195,7 @@ struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, const int stat
tw->tw_transparent = inet->transparent;
tw->tw_prot = sk->sk_prot_creator;
atomic64_set(&tw->tw_cookie, atomic64_read(&sk->sk_cookie));
twsk_net_set(tw, hold_net(sock_net(sk)));
twsk_net_set(tw, sock_net(sk));
/*
* Because we use RCU lookups, we should not set tw_refcnt
* to a non null value before everything is setup for this

View File

@ -73,9 +73,7 @@
struct mr_table {
struct list_head list;
#ifdef CONFIG_NET_NS
struct net *net;
#endif
possible_net_t net;
u32 id;
struct sock __rcu *mroute_sk;
struct timer_list ipmr_expire_timer;

View File

@ -29,9 +29,7 @@
* Policy Table
*/
struct ip6addrlbl_entry {
#ifdef CONFIG_NET_NS
struct net *lbl_net;
#endif
possible_net_t lbl_net;
struct in6_addr prefix;
int prefixlen;
int ifindex;
@ -129,9 +127,6 @@ static const __net_initconst struct ip6addrlbl_init_table
/* Object management */
static inline void ip6addrlbl_free(struct ip6addrlbl_entry *p)
{
#ifdef CONFIG_NET_NS
release_net(p->lbl_net);
#endif
kfree(p);
}
@ -240,9 +235,7 @@ static struct ip6addrlbl_entry *ip6addrlbl_alloc(struct net *net,
newp->addrtype = addrtype;
newp->label = label;
INIT_HLIST_NODE(&newp->list);
#ifdef CONFIG_NET_NS
newp->lbl_net = hold_net(net);
#endif
write_pnet(&newp->lbl_net, net);
atomic_set(&newp->refcnt, 1);
return newp;
}

View File

@ -100,7 +100,6 @@ static void fl_free(struct ip6_flowlabel *fl)
if (fl) {
if (fl->share == IPV6_FL_S_PROCESS)
put_pid(fl->owner.pid);
release_net(fl->fl_net);
kfree(fl->opt);
kfree_rcu(fl, rcu);
}
@ -403,7 +402,7 @@ fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
}
}
fl->fl_net = hold_net(net);
fl->fl_net = net;
fl->expires = jiffies;
err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
if (err)

View File

@ -56,9 +56,7 @@
struct mr6_table {
struct list_head list;
#ifdef CONFIG_NET_NS
struct net *net;
#endif
possible_net_t net;
u32 id;
struct sock *mroute6_sk;
struct timer_list ipmr_expire_timer;

View File

@ -203,7 +203,6 @@ static void destroy_dp_rcu(struct rcu_head *rcu)
ovs_flow_tbl_destroy(&dp->table);
free_percpu(dp->stats_percpu);
release_net(ovs_dp_get_net(dp));
kfree(dp->ports);
kfree(dp);
}
@ -1501,7 +1500,7 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
if (dp == NULL)
goto err_free_reply;
ovs_dp_set_net(dp, hold_net(sock_net(skb->sk)));
ovs_dp_set_net(dp, sock_net(skb->sk));
/* Allocate table. */
err = ovs_flow_tbl_init(&dp->table);
@ -1575,7 +1574,6 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
err_destroy_table:
ovs_flow_tbl_destroy(&dp->table);
err_free_dp:
release_net(ovs_dp_get_net(dp));
kfree(dp);
err_free_reply:
kfree_skb(reply);

View File

@ -84,10 +84,8 @@ struct datapath {
/* Stats. */
struct dp_stats_percpu __percpu *stats_percpu;
#ifdef CONFIG_NET_NS
/* Network namespace ref. */
struct net *net;
#endif
possible_net_t net;
u32 user_features;
};

View File

@ -74,9 +74,7 @@ extern struct mutex fanout_mutex;
#define PACKET_FANOUT_MAX 256
struct packet_fanout {
#ifdef CONFIG_NET_NS
struct net *net;
#endif
possible_net_t net;
unsigned int num_members;
u16 id;
u8 type;