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Diffstat (limited to 'net/ipv6/ip6_flowlabel.c')
-rw-r--r--net/ipv6/ip6_flowlabel.c161
1 files changed, 96 insertions, 65 deletions
diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c
index d6de4b447250..ea42bf40a997 100644
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -51,25 +51,38 @@
#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(fl_ht[(hash)]); \
+ fl != NULL; \
+ fl = rcu_dereference(fl->next))
+#define for_each_fl_continue_rcu(fl) \
+ for (fl = rcu_dereference(fl->next); \
+ 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;
- 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 */
@@ -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)