diff options
| -rw-r--r-- | net/decnet/dn_rules.c | 97 |
1 files changed, 53 insertions, 44 deletions
diff --git a/net/decnet/dn_rules.c b/net/decnet/dn_rules.c index f2c299dfe030..446faafe2065 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); } |
