ipv6 flowlabel: Convert np->ipv6_fl_list to RCU.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index e971e3742172c0c7817d1933fffa8bcf67f13492..850e95bc766c8504d4fbc2c592c1327ef5994431 100644 (file)
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -214,7 +214,7 @@ struct ipv6_pinfo {
 
        struct ipv6_mc_socklist __rcu *ipv6_mc_list;
        struct ipv6_ac_socklist *ipv6_ac_list;
-       struct ipv6_fl_socklist *ipv6_fl_list;
+       struct ipv6_fl_socklist __rcu *ipv6_fl_list;
 
        struct ipv6_txoptions   *opt;
        struct sk_buff          *pktoptions;

diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index 1d457161def255dc5a3aa9e842881c4417407710..851d5412a299ba95510305f35cf45bdd7b55dbdc 100644 (file)
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -239,6 +239,7 @@ struct ip6_flowlabel {
 struct ipv6_fl_socklist {
        struct ipv6_fl_socklist *next;
        struct ip6_flowlabel    *fl;
+       struct rcu_head         rcu;
 };
 
 extern struct ip6_flowlabel    *fl6_sock_lookup(struct sock *sk, __be32 label);

diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c
index da156015d827d6eeeadaae006c61306eefb8aaa3..22494afd981cb0095e92a3bddf36467d86ce2da9 100644 (file)
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -62,7 +62,7 @@ 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(fl_ht[(hash)]);               \
@@ -73,6 +73,11 @@ static DEFINE_RWLOCK(ip6_sk_fl_lock);
             fl != NULL;                                        \
             fl = rcu_dereference(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;
@@ -244,17 +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;
 }
 
@@ -265,20 +270,21 @@ void fl6_free_socklist(struct sock *sk)
        struct ipv6_pinfo *np = inet6_sk(sk);
        struct ipv6_fl_socklist *sfl;
 
-       if (!np->ipv6_fl_list)
+       if (!rcu_access_pointer(np->ipv6_fl_list))
                return;
 
-       write_lock_bh(&ipv6_sk_fl_lock);
-       sfl = np->ipv6_fl_list;
-       np->ipv6_fl_list = NULL;
-       write_unlock_bh(&ipv6_sk_fl_lock);
+       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);
 
-       while (sfl) {
-               struct ipv6_fl_socklist *next = sfl->next;
                fl_release(sfl->fl);
-               kfree(sfl);
-               sfl = next;
+               kfree_rcu(sfl, rcu);
+
+               spin_lock_bh(&ip6_sk_fl_lock);
        }
+       spin_unlock_bh(&ip6_sk_fl_lock);
 }
 
 /* Service routines */
@@ -443,7 +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 ||
@@ -486,11 +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)
@@ -512,31 +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)) {
@@ -560,11 +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;
@@ -572,7 +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);