6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Kui-Feng Lee thinker.li@gmail.com
[ Upstream commit 5eb902b8e7193cdcb33242af0a56502e6b5206e9 ]
FIB6 GC walks trees of fib6_tables to remove expired routes. Walking a tree can be expensive if the number of routes in a table is big, even if most of them are permanent. Checking routes in a separated list of routes having expiration will avoid this potential issue.
Reviewed-by: David Ahern dsahern@kernel.org Signed-off-by: Kui-Feng Lee thinker.li@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Stable-dep-of: f72514b3c569 ("ipv6: clear RA flags when adding a static route") Signed-off-by: Sasha Levin sashal@kernel.org --- include/net/ip6_fib.h | 46 ++++++++++++++++++++++++++++++++- net/ipv6/addrconf.c | 41 ++++++++++++++++++++++++----- net/ipv6/ip6_fib.c | 60 +++++++++++++++++++++++++++++++++++++++---- net/ipv6/ndisc.c | 10 +++++++- net/ipv6/route.c | 13 ++++++++-- 5 files changed, 154 insertions(+), 16 deletions(-)
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h index 1121d614942c8..f4c5b705418c0 100644 --- a/include/net/ip6_fib.h +++ b/include/net/ip6_fib.h @@ -179,6 +179,9 @@ struct fib6_info {
refcount_t fib6_ref; unsigned long expires; + + struct hlist_node gc_link; + struct dst_metrics *fib6_metrics; #define fib6_pmtu fib6_metrics->metrics[RTAX_MTU-1]
@@ -249,12 +252,18 @@ static inline bool fib6_requires_src(const struct fib6_info *rt) return rt->fib6_src.plen > 0; }
+/* The callers should hold f6i->fib6_table->tb6_lock if a route has ever + * been added to a table before. + */ static inline void fib6_clean_expires(struct fib6_info *f6i) { f6i->fib6_flags &= ~RTF_EXPIRES; f6i->expires = 0; }
+/* The callers should hold f6i->fib6_table->tb6_lock if a route has ever + * been added to a table before. + */ static inline void fib6_set_expires(struct fib6_info *f6i, unsigned long expires) { @@ -335,8 +344,10 @@ static inline bool fib6_info_hold_safe(struct fib6_info *f6i)
static inline void fib6_info_release(struct fib6_info *f6i) { - if (f6i && refcount_dec_and_test(&f6i->fib6_ref)) + if (f6i && refcount_dec_and_test(&f6i->fib6_ref)) { + DEBUG_NET_WARN_ON_ONCE(!hlist_unhashed(&f6i->gc_link)); call_rcu(&f6i->rcu, fib6_info_destroy_rcu); + } }
enum fib6_walk_state { @@ -390,6 +401,7 @@ struct fib6_table { struct inet_peer_base tb6_peers; unsigned int flags; unsigned int fib_seq; + struct hlist_head tb6_gc_hlist; /* GC candidates */ #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0) };
@@ -506,6 +518,38 @@ void fib6_gc_cleanup(void);
int fib6_init(void);
+/* Add the route to the gc list if it is not already there + * + * The callers should hold f6i->fib6_table->tb6_lock. + */ +static inline void fib6_add_gc_list(struct fib6_info *f6i) +{ + /* If fib6_node is null, the f6i is not in (or removed from) the + * table. + * + * There is a gap between finding the f6i from the table and + * calling this function without the protection of the tb6_lock. + * This check makes sure the f6i is not added to the gc list when + * it is not on the table. + */ + if (!rcu_dereference_protected(f6i->fib6_node, + lockdep_is_held(&f6i->fib6_table->tb6_lock))) + return; + + if (hlist_unhashed(&f6i->gc_link)) + hlist_add_head(&f6i->gc_link, &f6i->fib6_table->tb6_gc_hlist); +} + +/* Remove the route from the gc list if it is on the list. + * + * The callers should hold f6i->fib6_table->tb6_lock. + */ +static inline void fib6_remove_gc_list(struct fib6_info *f6i) +{ + if (!hlist_unhashed(&f6i->gc_link)) + hlist_del_init(&f6i->gc_link); +} + struct ipv6_route_iter { struct seq_net_private p; struct fib6_walker w; diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 0e49ee83533b5..b606d77fe7fce 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -1268,6 +1268,7 @@ static void cleanup_prefix_route(struct inet6_ifaddr *ifp, unsigned long expires, bool del_rt, bool del_peer) { + struct fib6_table *table; struct fib6_info *f6i;
f6i = addrconf_get_prefix_route(del_peer ? &ifp->peer_addr : &ifp->addr, @@ -1277,8 +1278,15 @@ cleanup_prefix_route(struct inet6_ifaddr *ifp, unsigned long expires, if (del_rt) ip6_del_rt(dev_net(ifp->idev->dev), f6i, false); else { - if (!(f6i->fib6_flags & RTF_EXPIRES)) + if (!(f6i->fib6_flags & RTF_EXPIRES)) { + table = f6i->fib6_table; + spin_lock_bh(&table->tb6_lock); + fib6_set_expires(f6i, expires); + fib6_add_gc_list(f6i); + + spin_unlock_bh(&table->tb6_lock); + } fib6_info_release(f6i); } } @@ -2736,6 +2744,7 @@ EXPORT_SYMBOL_GPL(addrconf_prefix_rcv_add_addr); void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len, bool sllao) { struct prefix_info *pinfo; + struct fib6_table *table; __u32 valid_lft; __u32 prefered_lft; int addr_type, err; @@ -2812,11 +2821,20 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len, bool sllao) if (valid_lft == 0) { ip6_del_rt(net, rt, false); rt = NULL; - } else if (addrconf_finite_timeout(rt_expires)) { - /* not infinity */ - fib6_set_expires(rt, jiffies + rt_expires); } else { - fib6_clean_expires(rt); + table = rt->fib6_table; + spin_lock_bh(&table->tb6_lock); + + if (addrconf_finite_timeout(rt_expires)) { + /* not infinity */ + fib6_set_expires(rt, jiffies + rt_expires); + fib6_add_gc_list(rt); + } else { + fib6_clean_expires(rt); + fib6_remove_gc_list(rt); + } + + spin_unlock_bh(&table->tb6_lock); } } else if (valid_lft) { clock_t expires = 0; @@ -4770,6 +4788,7 @@ static int modify_prefix_route(struct inet6_ifaddr *ifp, unsigned long expires, u32 flags, bool modify_peer) { + struct fib6_table *table; struct fib6_info *f6i; u32 prio;
@@ -4790,10 +4809,18 @@ static int modify_prefix_route(struct inet6_ifaddr *ifp, ifp->rt_priority, ifp->idev->dev, expires, flags, GFP_KERNEL); } else { - if (!expires) + table = f6i->fib6_table; + spin_lock_bh(&table->tb6_lock); + + if (!expires) { fib6_clean_expires(f6i); - else + fib6_remove_gc_list(f6i); + } else { fib6_set_expires(f6i, expires); + fib6_add_gc_list(f6i); + } + + spin_unlock_bh(&table->tb6_lock);
fib6_info_release(f6i); } diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index c44136cbbaa1f..ab84e2dd682f8 100644 --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -160,6 +160,8 @@ struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh) INIT_LIST_HEAD(&f6i->fib6_siblings); refcount_set(&f6i->fib6_ref, 1);
+ INIT_HLIST_NODE(&f6i->gc_link); + return f6i; }
@@ -246,6 +248,7 @@ static struct fib6_table *fib6_alloc_table(struct net *net, u32 id) net->ipv6.fib6_null_entry); table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; inet_peer_base_init(&table->tb6_peers); + INIT_HLIST_HEAD(&table->tb6_gc_hlist); }
return table; @@ -1063,6 +1066,9 @@ static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn, lockdep_is_held(&table->tb6_lock)); } } + + fib6_clean_expires(rt); + fib6_remove_gc_list(rt); }
/* @@ -1123,10 +1129,13 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt, WRITE_ONCE(rt->fib6_nsiblings, 0); if (!(iter->fib6_flags & RTF_EXPIRES)) return -EEXIST; - if (!(rt->fib6_flags & RTF_EXPIRES)) + if (!(rt->fib6_flags & RTF_EXPIRES)) { fib6_clean_expires(iter); - else + fib6_remove_gc_list(iter); + } else { fib6_set_expires(iter, rt->expires); + fib6_add_gc_list(iter); + }
if (rt->fib6_pmtu) fib6_metric_set(iter, RTAX_MTU, @@ -1491,6 +1500,10 @@ int fib6_add(struct fib6_node *root, struct fib6_info *rt, if (rt->nh) list_add(&rt->nh_list, &rt->nh->f6i_list); __fib6_update_sernum_upto_root(rt, fib6_new_sernum(info->nl_net)); + + if (rt->fib6_flags & RTF_EXPIRES) + fib6_add_gc_list(rt); + fib6_start_gc(info->nl_net, rt); }
@@ -2294,9 +2307,8 @@ static void fib6_flush_trees(struct net *net) * Garbage collection */
-static int fib6_age(struct fib6_info *rt, void *arg) +static int fib6_age(struct fib6_info *rt, struct fib6_gc_args *gc_args) { - struct fib6_gc_args *gc_args = arg; unsigned long now = jiffies;
/* @@ -2321,6 +2333,42 @@ static int fib6_age(struct fib6_info *rt, void *arg) return 0; }
+static void fib6_gc_table(struct net *net, + struct fib6_table *tb6, + struct fib6_gc_args *gc_args) +{ + struct fib6_info *rt; + struct hlist_node *n; + struct nl_info info = { + .nl_net = net, + .skip_notify = false, + }; + + hlist_for_each_entry_safe(rt, n, &tb6->tb6_gc_hlist, gc_link) + if (fib6_age(rt, gc_args) == -1) + fib6_del(rt, &info); +} + +static void fib6_gc_all(struct net *net, struct fib6_gc_args *gc_args) +{ + struct fib6_table *table; + struct hlist_head *head; + unsigned int h; + + rcu_read_lock(); + for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { + head = &net->ipv6.fib_table_hash[h]; + hlist_for_each_entry_rcu(table, head, tb6_hlist) { + spin_lock_bh(&table->tb6_lock); + + fib6_gc_table(net, table, gc_args); + + spin_unlock_bh(&table->tb6_lock); + } + } + rcu_read_unlock(); +} + void fib6_run_gc(unsigned long expires, struct net *net, bool force) { struct fib6_gc_args gc_args; @@ -2336,7 +2384,7 @@ void fib6_run_gc(unsigned long expires, struct net *net, bool force) net->ipv6.sysctl.ip6_rt_gc_interval; gc_args.more = 0;
- fib6_clean_all(net, fib6_age, &gc_args); + fib6_gc_all(net, &gc_args); now = jiffies; net->ipv6.ip6_rt_last_gc = now;
@@ -2396,6 +2444,7 @@ static int __net_init fib6_net_init(struct net *net) net->ipv6.fib6_main_tbl->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); + INIT_HLIST_HEAD(&net->ipv6.fib6_main_tbl->tb6_gc_hlist);
#ifdef CONFIG_IPV6_MULTIPLE_TABLES net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl), @@ -2408,6 +2457,7 @@ static int __net_init fib6_net_init(struct net *net) net->ipv6.fib6_local_tbl->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); + INIT_HLIST_HEAD(&net->ipv6.fib6_local_tbl->tb6_gc_hlist); #endif fib6_tables_init(net);
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index 8d853971f2f68..d8e5e2833eded 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -1241,6 +1241,7 @@ static enum skb_drop_reason ndisc_router_discovery(struct sk_buff *skb) struct ndisc_options ndopts; struct fib6_info *rt = NULL; struct inet6_dev *in6_dev; + struct fib6_table *table; u32 defrtr_usr_metric; unsigned int pref = 0; __u32 old_if_flags; @@ -1413,8 +1414,15 @@ static enum skb_drop_reason ndisc_router_discovery(struct sk_buff *skb) inet6_rt_notify(RTM_NEWROUTE, rt, &nlinfo, NLM_F_REPLACE); }
- if (rt) + if (rt) { + table = rt->fib6_table; + spin_lock_bh(&table->tb6_lock); + fib6_set_expires(rt, jiffies + (HZ * lifetime)); + fib6_add_gc_list(rt); + + spin_unlock_bh(&table->tb6_lock); + } if (in6_dev->cnf.accept_ra_min_hop_limit < 256 && ra_msg->icmph.icmp6_hop_limit) { if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) { diff --git a/net/ipv6/route.c b/net/ipv6/route.c index eb9e505f71f97..929f92b555113 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -971,6 +971,7 @@ int rt6_route_rcv(struct net_device *dev, u8 *opt, int len, struct net *net = dev_net(dev); struct route_info *rinfo = (struct route_info *) opt; struct in6_addr prefix_buf, *prefix; + struct fib6_table *table; unsigned int pref; unsigned long lifetime; struct fib6_info *rt; @@ -1029,10 +1030,18 @@ int rt6_route_rcv(struct net_device *dev, u8 *opt, int len, (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
if (rt) { - if (!addrconf_finite_timeout(lifetime)) + table = rt->fib6_table; + spin_lock_bh(&table->tb6_lock); + + if (!addrconf_finite_timeout(lifetime)) { fib6_clean_expires(rt); - else + fib6_remove_gc_list(rt); + } else { fib6_set_expires(rt, jiffies + HZ * lifetime); + fib6_add_gc_list(rt); + } + + spin_unlock_bh(&table->tb6_lock);
fib6_info_release(rt); }