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Message-Id: <20230718183351.297506-2-kuifeng@meta.com>
Date: Tue, 18 Jul 2023 11:33:50 -0700
From: Kui-Feng Lee <thinker.li@...il.com>
To: dsahern@...nel.org,
davem@...emloft.net,
edumazet@...gle.com,
kuba@...nel.org,
netdev@...r.kernel.org,
pabeni@...hat.com,
martin.lau@...ux.dev,
kernel-team@...a.com,
yhs@...a.com
Cc: Kui-Feng Lee <kuifeng@...a.com>
Subject: [PATCH net-next v3 1/2] 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 <kuifeng@...a.com>
---
include/net/ip6_fib.h | 65 ++++++++++++++++++++++++++++++++++---------
net/ipv6/ip6_fib.c | 53 ++++++++++++++++++++++++++++++++---
net/ipv6/route.c | 6 ++--
3 files changed, 104 insertions(+), 20 deletions(-)
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index 05e6f756feaf..e6f4d986fb63 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 +500,49 @@ 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)
+{
+ struct fib6_table *tb6;
+
+ tb6 = f6i->fib6_table;
+ if (tb6 && 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..a4422d513d4d 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 +1060,11 @@ static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn,
lockdep_is_held(&table->tb6_lock));
}
}
+
+ if (fib6_has_expires(rt)) {
+ hlist_del_init(&rt->gc_link);
+ rt->fib6_flags &= ~RTF_EXPIRES;
+ }
}
/*
@@ -1118,9 +1126,9 @@ 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,
@@ -1480,6 +1488,9 @@ int fib6_add(struct fib6_node *root, struct fib6_info *rt,
list_add(&rt->nh_list, &rt->nh->f6i_list);
__fib6_update_sernum_upto_root(rt, fib6_new_sernum(info->nl_net));
fib6_start_gc(info->nl_net, rt);
+
+ if (fib6_has_expires(rt))
+ hlist_add_head(&rt->gc_link, &table->tb6_gc_hlist);
}
out:
@@ -2295,7 +2306,7 @@ 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 +2323,40 @@ static int fib6_age(struct fib6_info *rt, void *arg)
return 0;
}
+static void fib6_gc_table(struct net *net,
+ struct fib6_table *tb6,
+ void *arg)
+{
+ 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, arg) == -1)
+ fib6_del(rt, &info);
+}
+
+static void fib6_gc_all(struct net *net, void *arg)
+{
+ 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, arg);
+ 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 +2372,7 @@ 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 64e873f5895f..a69083563689 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -3760,10 +3760,10 @@ 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;
--
2.34.1
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