v4 GRE: Add TCP segmentation offload for GRE
[firefly-linux-kernel-4.4.55.git] / net / ipv6 / ip6_flowlabel.c
index 29124b7a04c8dfb335df69014b5348e22b3fb6ab..a7da2f4724791473608e2bb745fd293a889f07e1 100644 (file)
 #define FL_HASH(l)     (ntohl(l)&FL_HASH_MASK)
 
 static atomic_t fl_size = ATOMIC_INIT(0);
-static struct ip6_flowlabel *fl_ht[FL_HASH_MASK+1];
+static struct ip6_flowlabel __rcu *fl_ht[FL_HASH_MASK+1];
 
 static void ip6_fl_gc(unsigned long dummy);
 static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc, 0, 0);
 
 /* FL hash table lock: it protects only of GC */
 
-static DEFINE_RWLOCK(ip6_fl_lock);
+static DEFINE_SPINLOCK(ip6_fl_lock);
 
 /* Big socket sock */
 
-static DEFINE_RWLOCK(ip6_sk_fl_lock);
+static DEFINE_SPINLOCK(ip6_sk_fl_lock);
 
+#define for_each_fl_rcu(hash, fl)                              \
+       for (fl = rcu_dereference_bh(fl_ht[(hash)]);            \
+            fl != NULL;                                        \
+            fl = rcu_dereference_bh(fl->next))
+#define for_each_fl_continue_rcu(fl)                           \
+       for (fl = rcu_dereference_bh(fl->next);                 \
+            fl != NULL;                                        \
+            fl = rcu_dereference_bh(fl->next))
+
+#define for_each_sk_fl_rcu(np, sfl)                            \
+       for (sfl = rcu_dereference_bh(np->ipv6_fl_list);        \
+            sfl != NULL;                                       \
+            sfl = rcu_dereference_bh(sfl->next))
 
 static inline struct ip6_flowlabel *__fl_lookup(struct net *net, __be32 label)
 {
        struct ip6_flowlabel *fl;
 
-       for (fl=fl_ht[FL_HASH(label)]; fl; fl = fl->next) {
+       for_each_fl_rcu(FL_HASH(label), fl) {
                if (fl->label == label && net_eq(fl->fl_net, net))
                        return fl;
        }
@@ -80,11 +93,11 @@ static struct ip6_flowlabel *fl_lookup(struct net *net, __be32 label)
 {
        struct ip6_flowlabel *fl;
 
-       read_lock_bh(&ip6_fl_lock);
+       rcu_read_lock_bh();
        fl = __fl_lookup(net, label);
-       if (fl)
-               atomic_inc(&fl->users);
-       read_unlock_bh(&ip6_fl_lock);
+       if (fl && !atomic_inc_not_zero(&fl->users))
+               fl = NULL;
+       rcu_read_unlock_bh();
        return fl;
 }
 
@@ -96,13 +109,13 @@ static void fl_free(struct ip6_flowlabel *fl)
                        put_pid(fl->owner.pid);
                release_net(fl->fl_net);
                kfree(fl->opt);
+               kfree_rcu(fl, rcu);
        }
-       kfree(fl);
 }
 
 static void fl_release(struct ip6_flowlabel *fl)
 {
-       write_lock_bh(&ip6_fl_lock);
+       spin_lock_bh(&ip6_fl_lock);
 
        fl->lastuse = jiffies;
        if (atomic_dec_and_test(&fl->users)) {
@@ -119,7 +132,7 @@ static void fl_release(struct ip6_flowlabel *fl)
                    time_after(ip6_fl_gc_timer.expires, ttd))
                        mod_timer(&ip6_fl_gc_timer, ttd);
        }
-       write_unlock_bh(&ip6_fl_lock);
+       spin_unlock_bh(&ip6_fl_lock);
 }
 
 static void ip6_fl_gc(unsigned long dummy)
@@ -128,12 +141,13 @@ static void ip6_fl_gc(unsigned long dummy)
        unsigned long now = jiffies;
        unsigned long sched = 0;
 
-       write_lock(&ip6_fl_lock);
+       spin_lock(&ip6_fl_lock);
 
        for (i=0; i<=FL_HASH_MASK; i++) {
                struct ip6_flowlabel *fl, **flp;
                flp = &fl_ht[i];
-               while ((fl=*flp) != NULL) {
+               while ((fl = rcu_dereference_protected(*flp,
+                                                      lockdep_is_held(&ip6_fl_lock))) != NULL) {
                        if (atomic_read(&fl->users) == 0) {
                                unsigned long ttd = fl->lastuse + fl->linger;
                                if (time_after(ttd, fl->expires))
@@ -156,18 +170,19 @@ static void ip6_fl_gc(unsigned long dummy)
        if (sched) {
                mod_timer(&ip6_fl_gc_timer, sched);
        }
-       write_unlock(&ip6_fl_lock);
+       spin_unlock(&ip6_fl_lock);
 }
 
 static void __net_exit ip6_fl_purge(struct net *net)
 {
        int i;
 
-       write_lock(&ip6_fl_lock);
+       spin_lock(&ip6_fl_lock);
        for (i = 0; i <= FL_HASH_MASK; i++) {
                struct ip6_flowlabel *fl, **flp;
                flp = &fl_ht[i];
-               while ((fl = *flp) != NULL) {
+               while ((fl = rcu_dereference_protected(*flp,
+                                                      lockdep_is_held(&ip6_fl_lock))) != NULL) {
                        if (net_eq(fl->fl_net, net) &&
                            atomic_read(&fl->users) == 0) {
                                *flp = fl->next;
@@ -178,7 +193,7 @@ static void __net_exit ip6_fl_purge(struct net *net)
                        flp = &fl->next;
                }
        }
-       write_unlock(&ip6_fl_lock);
+       spin_unlock(&ip6_fl_lock);
 }
 
 static struct ip6_flowlabel *fl_intern(struct net *net,
@@ -188,7 +203,7 @@ static struct ip6_flowlabel *fl_intern(struct net *net,
 
        fl->label = label & IPV6_FLOWLABEL_MASK;
 
-       write_lock_bh(&ip6_fl_lock);
+       spin_lock_bh(&ip6_fl_lock);
        if (label == 0) {
                for (;;) {
                        fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK;
@@ -210,16 +225,16 @@ static struct ip6_flowlabel *fl_intern(struct net *net,
                lfl = __fl_lookup(net, fl->label);
                if (lfl != NULL) {
                        atomic_inc(&lfl->users);
-                       write_unlock_bh(&ip6_fl_lock);
+                       spin_unlock_bh(&ip6_fl_lock);
                        return lfl;
                }
        }
 
        fl->lastuse = jiffies;
        fl->next = fl_ht[FL_HASH(fl->label)];
-       fl_ht[FL_HASH(fl->label)] = fl;
+       rcu_assign_pointer(fl_ht[FL_HASH(fl->label)], fl);
        atomic_inc(&fl_size);
-       write_unlock_bh(&ip6_fl_lock);
+       spin_unlock_bh(&ip6_fl_lock);
        return NULL;
 }
 
@@ -234,17 +249,17 @@ struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, __be32 label)
 
        label &= IPV6_FLOWLABEL_MASK;
 
-       read_lock_bh(&ip6_sk_fl_lock);
-       for (sfl=np->ipv6_fl_list; sfl; sfl = sfl->next) {
+       rcu_read_lock_bh();
+       for_each_sk_fl_rcu(np, sfl) {
                struct ip6_flowlabel *fl = sfl->fl;
                if (fl->label == label) {
                        fl->lastuse = jiffies;
                        atomic_inc(&fl->users);
-                       read_unlock_bh(&ip6_sk_fl_lock);
+                       rcu_read_unlock_bh();
                        return fl;
                }
        }
-       read_unlock_bh(&ip6_sk_fl_lock);
+       rcu_read_unlock_bh();
        return NULL;
 }
 
@@ -255,11 +270,21 @@ void fl6_free_socklist(struct sock *sk)
        struct ipv6_pinfo *np = inet6_sk(sk);
        struct ipv6_fl_socklist *sfl;
 
-       while ((sfl = np->ipv6_fl_list) != NULL) {
+       if (!rcu_access_pointer(np->ipv6_fl_list))
+               return;
+
+       spin_lock_bh(&ip6_sk_fl_lock);
+       while ((sfl = rcu_dereference_protected(np->ipv6_fl_list,
+                                               lockdep_is_held(&ip6_sk_fl_lock))) != NULL) {
                np->ipv6_fl_list = sfl->next;
+               spin_unlock_bh(&ip6_sk_fl_lock);
+
                fl_release(sfl->fl);
-               kfree(sfl);
+               kfree_rcu(sfl, rcu);
+
+               spin_lock_bh(&ip6_sk_fl_lock);
        }
+       spin_unlock_bh(&ip6_sk_fl_lock);
 }
 
 /* Service routines */
@@ -365,8 +390,8 @@ fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
                msg.msg_control = (void*)(fl->opt+1);
                memset(&flowi6, 0, sizeof(flowi6));
 
-               err = datagram_send_ctl(net, sk, &msg, &flowi6, fl->opt, &junk,
-                                       &junk, &junk);
+               err = ip6_datagram_send_ctl(net, sk, &msg, &flowi6, fl->opt,
+                                           &junk, &junk, &junk);
                if (err)
                        goto done;
                err = -EINVAL;
@@ -424,7 +449,7 @@ static int mem_check(struct sock *sk)
        if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
                return 0;
 
-       for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next)
+       for_each_sk_fl_rcu(np, sfl)
                count++;
 
        if (room <= 0 ||
@@ -467,11 +492,11 @@ static bool ipv6_opt_cmp(struct ipv6_txoptions *o1, struct ipv6_txoptions *o2)
 static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
                struct ip6_flowlabel *fl)
 {
-       write_lock_bh(&ip6_sk_fl_lock);
+       spin_lock_bh(&ip6_sk_fl_lock);
        sfl->fl = fl;
        sfl->next = np->ipv6_fl_list;
-       np->ipv6_fl_list = sfl;
-       write_unlock_bh(&ip6_sk_fl_lock);
+       rcu_assign_pointer(np->ipv6_fl_list, sfl);
+       spin_unlock_bh(&ip6_sk_fl_lock);
 }
 
 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
@@ -493,31 +518,33 @@ int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
 
        switch (freq.flr_action) {
        case IPV6_FL_A_PUT:
-               write_lock_bh(&ip6_sk_fl_lock);
-               for (sflp = &np->ipv6_fl_list; (sfl=*sflp)!=NULL; sflp = &sfl->next) {
+               spin_lock_bh(&ip6_sk_fl_lock);
+               for (sflp = &np->ipv6_fl_list;
+                    (sfl = rcu_dereference(*sflp))!=NULL;
+                    sflp = &sfl->next) {
                        if (sfl->fl->label == freq.flr_label) {
                                if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
                                        np->flow_label &= ~IPV6_FLOWLABEL_MASK;
-                               *sflp = sfl->next;
-                               write_unlock_bh(&ip6_sk_fl_lock);
+                               *sflp = rcu_dereference(sfl->next);
+                               spin_unlock_bh(&ip6_sk_fl_lock);
                                fl_release(sfl->fl);
-                               kfree(sfl);
+                               kfree_rcu(sfl, rcu);
                                return 0;
                        }
                }
-               write_unlock_bh(&ip6_sk_fl_lock);
+               spin_unlock_bh(&ip6_sk_fl_lock);
                return -ESRCH;
 
        case IPV6_FL_A_RENEW:
-               read_lock_bh(&ip6_sk_fl_lock);
-               for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
+               rcu_read_lock_bh();
+               for_each_sk_fl_rcu(np, sfl) {
                        if (sfl->fl->label == freq.flr_label) {
                                err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
-                               read_unlock_bh(&ip6_sk_fl_lock);
+                               rcu_read_unlock_bh();
                                return err;
                        }
                }
-               read_unlock_bh(&ip6_sk_fl_lock);
+               rcu_read_unlock_bh();
 
                if (freq.flr_share == IPV6_FL_S_NONE &&
                    ns_capable(net->user_ns, CAP_NET_ADMIN)) {
@@ -541,11 +568,11 @@ int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
 
                if (freq.flr_label) {
                        err = -EEXIST;
-                       read_lock_bh(&ip6_sk_fl_lock);
-                       for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
+                       rcu_read_lock_bh();
+                       for_each_sk_fl_rcu(np, sfl) {
                                if (sfl->fl->label == freq.flr_label) {
                                        if (freq.flr_flags&IPV6_FL_F_EXCL) {
-                                               read_unlock_bh(&ip6_sk_fl_lock);
+                                               rcu_read_unlock_bh();
                                                goto done;
                                        }
                                        fl1 = sfl->fl;
@@ -553,7 +580,7 @@ int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
                                        break;
                                }
                        }
-                       read_unlock_bh(&ip6_sk_fl_lock);
+                       rcu_read_unlock_bh();
 
                        if (fl1 == NULL)
                                fl1 = fl_lookup(net, freq.flr_label);
@@ -641,13 +668,13 @@ static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
        struct net *net = seq_file_net(seq);
 
        for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
-               fl = fl_ht[state->bucket];
-
-               while (fl && !net_eq(fl->fl_net, net))
-                       fl = fl->next;
-               if (fl)
-                       break;
+               for_each_fl_rcu(state->bucket, fl) {
+                       if (net_eq(fl->fl_net, net))
+                               goto out;
+               }
        }
+       fl = NULL;
+out:
        return fl;
 }
 
@@ -656,18 +683,22 @@ static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flo
        struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
        struct net *net = seq_file_net(seq);
 
-       fl = fl->next;
+       for_each_fl_continue_rcu(fl) {
+               if (net_eq(fl->fl_net, net))
+                       goto out;
+       }
+
 try_again:
-       while (fl && !net_eq(fl->fl_net, net))
-               fl = fl->next;
-
-       while (!fl) {
-               if (++state->bucket <= FL_HASH_MASK) {
-                       fl = fl_ht[state->bucket];
-                       goto try_again;
-               } else
-                       break;
+       if (++state->bucket <= FL_HASH_MASK) {
+               for_each_fl_rcu(state->bucket, fl) {
+                       if (net_eq(fl->fl_net, net))
+                               goto out;
+               }
+               goto try_again;
        }
+       fl = NULL;
+
+out:
        return fl;
 }
 
@@ -681,9 +712,9 @@ static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
 }
 
 static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
-       __acquires(ip6_fl_lock)
+       __acquires(RCU)
 {
-       read_lock_bh(&ip6_fl_lock);
+       rcu_read_lock_bh();
        return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 }
 
@@ -700,9 +731,9 @@ static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 }
 
 static void ip6fl_seq_stop(struct seq_file *seq, void *v)
-       __releases(ip6_fl_lock)
+       __releases(RCU)
 {
-       read_unlock_bh(&ip6_fl_lock);
+       rcu_read_unlock_bh();
 }
 
 static int ip6fl_seq_show(struct seq_file *seq, void *v)