From 3dec89b14d37ee635e772636dad3f09f78f1ab87 Mon Sep 17 00:00:00 2001 From: Kui-Feng Lee Date: Tue, 15 Aug 2023 11:07:05 -0700 Subject: net/ipv6: Remove expired routes with a separated list of routes. 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. Signed-off-by: Kui-Feng Lee Reviewed-by: David Ahern Signed-off-by: David S. Miller --- include/net/ip6_fib.h | 64 ++++++++++++++++++++++++++++++++++++++++----------- net/ipv6/ip6_fib.c | 55 ++++++++++++++++++++++++++++++++++++++----- net/ipv6/route.c | 6 ++--- 3 files changed, 103 insertions(+), 22 deletions(-) diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h index 05e6f756feaf..c9ff23cf313e 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] @@ -247,19 +250,6 @@ static inline bool fib6_requires_src(const struct fib6_info *rt) return rt->fib6_src.plen > 0; } -static inline void fib6_clean_expires(struct fib6_info *f6i) -{ - f6i->fib6_flags &= ~RTF_EXPIRES; - f6i->expires = 0; -} - -static inline void fib6_set_expires(struct fib6_info *f6i, - unsigned long expires) -{ - f6i->expires = expires; - f6i->fib6_flags |= RTF_EXPIRES; -} - static inline bool fib6_check_expired(const struct fib6_info *f6i) { if (f6i->fib6_flags & RTF_EXPIRES) @@ -267,6 +257,11 @@ static inline bool fib6_check_expired(const struct fib6_info *f6i) return false; } +static inline bool fib6_has_expires(const struct fib6_info *f6i) +{ + return f6i->fib6_flags & RTF_EXPIRES; +} + /* Function to safely get fn->fn_sernum for passed in rt * and store result in passed in cookie. * Return true if we can get cookie safely @@ -388,6 +383,7 @@ 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) }; @@ -504,6 +500,48 @@ void fib6_gc_cleanup(void); int fib6_init(void); +/* fib6_info must be locked by the caller, and fib6_info->fib6_table can be + * NULL. + */ +static inline void fib6_set_expires_locked(struct fib6_info *f6i, + unsigned long expires) +{ + struct fib6_table *tb6; + + tb6 = f6i->fib6_table; + f6i->expires = expires; + if (tb6 && !fib6_has_expires(f6i)) + hlist_add_head(&f6i->gc_link, &tb6->tb6_gc_hlist); + f6i->fib6_flags |= RTF_EXPIRES; +} + +/* fib6_info must be locked by the caller, and fib6_info->fib6_table can be + * NULL. If fib6_table is NULL, the fib6_info will no be inserted into the + * list of GC candidates until it is inserted into a table. + */ +static inline void fib6_set_expires(struct fib6_info *f6i, + unsigned long expires) +{ + spin_lock_bh(&f6i->fib6_table->tb6_lock); + fib6_set_expires_locked(f6i, expires); + spin_unlock_bh(&f6i->fib6_table->tb6_lock); +} + +static inline void fib6_clean_expires_locked(struct fib6_info *f6i) +{ + if (fib6_has_expires(f6i)) + hlist_del_init(&f6i->gc_link); + f6i->fib6_flags &= ~RTF_EXPIRES; + f6i->expires = 0; +} + +static inline void fib6_clean_expires(struct fib6_info *f6i) +{ + spin_lock_bh(&f6i->fib6_table->tb6_lock); + fib6_clean_expires_locked(f6i); + spin_unlock_bh(&f6i->fib6_table->tb6_lock); +} + struct ipv6_route_iter { struct seq_net_private p; struct fib6_walker w; diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index bac768d36cc1..28b01a068412 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; @@ -1057,6 +1060,8 @@ static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn, lockdep_is_held(&table->tb6_lock)); } } + + fib6_clean_expires_locked(rt); } /* @@ -1118,9 +1123,10 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt, if (!(iter->fib6_flags & RTF_EXPIRES)) return -EEXIST; if (!(rt->fib6_flags & RTF_EXPIRES)) - fib6_clean_expires(iter); + fib6_clean_expires_locked(iter); else - fib6_set_expires(iter, rt->expires); + fib6_set_expires_locked(iter, + rt->expires); if (rt->fib6_pmtu) fib6_metric_set(iter, RTAX_MTU, @@ -1479,6 +1485,10 @@ 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 (fib6_has_expires(rt)) + hlist_add_head(&rt->gc_link, &table->tb6_gc_hlist); + fib6_start_gc(info->nl_net, rt); } @@ -2285,9 +2295,8 @@ 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; /* @@ -2295,7 +2304,7 @@ static int fib6_age(struct fib6_info *rt, void *arg) * Routes are expired even if they are in use. */ - if (rt->fib6_flags & RTF_EXPIRES && rt->expires) { + if (fib6_has_expires(rt) && rt->expires) { if (time_after(now, rt->expires)) { RT6_TRACE("expiring %p\n", rt); return -1; @@ -2312,6 +2321,40 @@ 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; @@ -2327,7 +2370,7 @@ 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; diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 10751df16dab..db10c36f34bb 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -3761,10 +3761,10 @@ static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg, rt->dst_nocount = true; if (cfg->fc_flags & RTF_EXPIRES) - fib6_set_expires(rt, jiffies + - clock_t_to_jiffies(cfg->fc_expires)); + fib6_set_expires_locked(rt, jiffies + + clock_t_to_jiffies(cfg->fc_expires)); else - fib6_clean_expires(rt); + fib6_clean_expires_locked(rt); if (cfg->fc_protocol == RTPROT_UNSPEC) cfg->fc_protocol = RTPROT_BOOT; -- cgit