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-rw-r--r--net/decnet/dn_rules.c97
1 files changed, 53 insertions, 44 deletions
diff --git a/net/decnet/dn_rules.c b/net/decnet/dn_rules.c
index f2c299d..446faaf 100644
--- a/net/decnet/dn_rules.c
+++ b/net/decnet/dn_rules.c
@@ -27,6 +27,8 @@
#include <linux/timer.h>
#include <linux/spinlock.h>
#include <linux/in_route.h>
+#include <linux/list.h>
+#include <linux/rcupdate.h>
#include <asm/atomic.h>
#include <asm/uaccess.h>
#include <net/neighbour.h>
@@ -39,7 +41,7 @@
struct dn_fib_rule
{
- struct dn_fib_rule *r_next;
+ struct hlist_node r_hlist;
atomic_t r_clntref;
u32 r_preference;
unsigned char r_table;
@@ -58,6 +60,7 @@ struct dn_fib_rule
int r_ifindex;
char r_ifname[IFNAMSIZ];
int r_dead;
+ struct rcu_head rcu;
};
static struct dn_fib_rule default_rule = {
@@ -67,18 +70,17 @@ static struct dn_fib_rule default_rule = {
.r_action = RTN_UNICAST
};
-static struct dn_fib_rule *dn_fib_rules = &default_rule;
-static DEFINE_RWLOCK(dn_fib_rules_lock);
-
+static struct hlist_head dn_fib_rules;
int dn_fib_rtm_delrule(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
{
struct rtattr **rta = arg;
struct rtmsg *rtm = NLMSG_DATA(nlh);
- struct dn_fib_rule *r, **rp;
+ struct dn_fib_rule *r;
+ struct hlist_node *node;
int err = -ESRCH;
- for(rp=&dn_fib_rules; (r=*rp) != NULL; rp = &r->r_next) {
+ hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
if ((!rta[RTA_SRC-1] || memcmp(RTA_DATA(rta[RTA_SRC-1]), &r->r_src, 2) == 0) &&
rtm->rtm_src_len == r->r_src_len &&
rtm->rtm_dst_len == r->r_dst_len &&
@@ -95,10 +97,8 @@ int dn_fib_rtm_delrule(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
if (r == &default_rule)
break;
- write_lock_bh(&dn_fib_rules_lock);
- *rp = r->r_next;
+ hlist_del_rcu(&r->r_hlist);
r->r_dead = 1;
- write_unlock_bh(&dn_fib_rules_lock);
dn_fib_rule_put(r);
err = 0;
break;
@@ -108,11 +108,17 @@ int dn_fib_rtm_delrule(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
return err;
}
+static inline void dn_fib_rule_put_rcu(struct rcu_head *head)
+{
+ struct dn_fib_rule *r = container_of(head, struct dn_fib_rule, rcu);
+ kfree(r);
+}
+
void dn_fib_rule_put(struct dn_fib_rule *r)
{
if (atomic_dec_and_test(&r->r_clntref)) {
if (r->r_dead)
- kfree(r);
+ call_rcu(&r->rcu, dn_fib_rule_put_rcu);
else
printk(KERN_DEBUG "Attempt to free alive dn_fib_rule\n");
}
@@ -123,7 +129,8 @@ int dn_fib_rtm_newrule(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
{
struct rtattr **rta = arg;
struct rtmsg *rtm = NLMSG_DATA(nlh);
- struct dn_fib_rule *r, *new_r, **rp;
+ struct dn_fib_rule *r, *new_r, *last = NULL;
+ struct hlist_node *node = NULL;
unsigned char table_id;
if (rtm->rtm_src_len > 16 || rtm->rtm_dst_len > 16)
@@ -149,6 +156,7 @@ int dn_fib_rtm_newrule(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
if (!new_r)
return -ENOMEM;
memset(new_r, 0, sizeof(*new_r));
+
if (rta[RTA_SRC-1])
memcpy(&new_r->r_src, RTA_DATA(rta[RTA_SRC-1]), 2);
if (rta[RTA_DST-1])
@@ -179,27 +187,26 @@ int dn_fib_rtm_newrule(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
}
}
- rp = &dn_fib_rules;
+ r = container_of(dn_fib_rules.first, struct dn_fib_rule, r_hlist);
if (!new_r->r_preference) {
- r = dn_fib_rules;
- if (r && (r = r->r_next) != NULL) {
- rp = &dn_fib_rules->r_next;
+ if (r && r->r_hlist.next != NULL) {
+ r = container_of(r->r_hlist.next, struct dn_fib_rule, r_hlist);
if (r->r_preference)
new_r->r_preference = r->r_preference - 1;
}
}
- while((r=*rp) != NULL) {
+ hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
if (r->r_preference > new_r->r_preference)
break;
- rp = &r->r_next;
+ last = r;
}
-
- new_r->r_next = r;
atomic_inc(&new_r->r_clntref);
- write_lock_bh(&dn_fib_rules_lock);
- *rp = new_r;
- write_unlock_bh(&dn_fib_rules_lock);
+
+ if (last)
+ hlist_add_after_rcu(&last->r_hlist, &new_r->r_hlist);
+ else
+ hlist_add_before_rcu(&new_r->r_hlist, &r->r_hlist);
return 0;
}
@@ -210,10 +217,12 @@ int dn_fib_lookup(const struct flowi *flp, struct dn_fib_res *res)
struct dn_fib_table *tb;
__le16 saddr = flp->fld_src;
__le16 daddr = flp->fld_dst;
+ struct hlist_node *node;
int err;
- read_lock(&dn_fib_rules_lock);
- for(r = dn_fib_rules; r; r = r->r_next) {
+ rcu_read_lock();
+
+ hlist_for_each_entry_rcu(r, node, &dn_fib_rules, r_hlist) {
if (((saddr^r->r_src) & r->r_srcmask) ||
((daddr^r->r_dst) & r->r_dstmask) ||
#ifdef CONFIG_DECNET_ROUTE_FWMARK
@@ -228,14 +237,14 @@ int dn_fib_lookup(const struct flowi *flp, struct dn_fib_res *res)
policy = r;
break;
case RTN_UNREACHABLE:
- read_unlock(&dn_fib_rules_lock);
+ rcu_read_unlock();
return -ENETUNREACH;
default:
case RTN_BLACKHOLE:
- read_unlock(&dn_fib_rules_lock);
+ rcu_read_unlock();
return -EINVAL;
case RTN_PROHIBIT:
- read_unlock(&dn_fib_rules_lock);
+ rcu_read_unlock();
return -EACCES;
}
@@ -246,16 +255,16 @@ int dn_fib_lookup(const struct flowi *flp, struct dn_fib_res *res)
res->r = policy;
if (policy)
atomic_inc(&policy->r_clntref);
- read_unlock(&dn_fib_rules_lock);
+ rcu_read_unlock();
return 0;
}
if (err < 0 && err != -EAGAIN) {
- read_unlock(&dn_fib_rules_lock);
+ rcu_read_unlock();
return err;
}
}
- read_unlock(&dn_fib_rules_lock);
+ rcu_read_unlock();
return -ESRCH;
}
@@ -297,27 +306,23 @@ __le16 dn_fib_rules_policy(__le16 saddr, struct dn_fib_res *res, unsigned *flags
static void dn_fib_rules_detach(struct net_device *dev)
{
+ struct hlist_node *node;
struct dn_fib_rule *r;
- for(r = dn_fib_rules; r; r = r->r_next) {
- if (r->r_ifindex == dev->ifindex) {
- write_lock_bh(&dn_fib_rules_lock);
+ hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
+ if (r->r_ifindex == dev->ifindex)
r->r_ifindex = -1;
- write_unlock_bh(&dn_fib_rules_lock);
- }
}
}
static void dn_fib_rules_attach(struct net_device *dev)
{
+ struct hlist_node *node;
struct dn_fib_rule *r;
- for(r = dn_fib_rules; r; r = r->r_next) {
- if (r->r_ifindex == -1 && strcmp(dev->name, r->r_ifname) == 0) {
- write_lock_bh(&dn_fib_rules_lock);
+ hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
+ if (r->r_ifindex == -1 && strcmp(dev->name, r->r_ifname) == 0)
r->r_ifindex = dev->ifindex;
- write_unlock_bh(&dn_fib_rules_lock);
- }
}
}
@@ -387,18 +392,20 @@ rtattr_failure:
int dn_fib_dump_rules(struct sk_buff *skb, struct netlink_callback *cb)
{
- int idx;
+ int idx = 0;
int s_idx = cb->args[0];
struct dn_fib_rule *r;
+ struct hlist_node *node;
- read_lock(&dn_fib_rules_lock);
- for(r = dn_fib_rules, idx = 0; r; r = r->r_next, idx++) {
+ rcu_read_lock();
+ hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
if (idx < s_idx)
continue;
if (dn_fib_fill_rule(skb, r, cb, NLM_F_MULTI) < 0)
break;
+ idx++;
}
- read_unlock(&dn_fib_rules_lock);
+ rcu_read_unlock();
cb->args[0] = idx;
return skb->len;
@@ -406,6 +413,8 @@ int dn_fib_dump_rules(struct sk_buff *skb, struct netlink_callback *cb)
void __init dn_fib_rules_init(void)
{
+ INIT_HLIST_HEAD(&dn_fib_rules);
+ hlist_add_head(&default_rule.r_hlist, &dn_fib_rules);
register_netdevice_notifier(&dn_fib_rules_notifier);
}
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