netns: selective flush of rt_cache
dst cache is marked as expired on the per/namespace basis by previous
path. Right now we have to implement selective cache shrinking. This
procedure has been ported from older OpenVz codebase.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 67c3ed7..113cd25 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -699,6 +699,7 @@
{
unsigned int i;
struct rtable *rth, *next;
+ struct rtable * tail;
for (i = 0; i <= rt_hash_mask; i++) {
if (process_context && need_resched())
@@ -708,11 +709,39 @@
continue;
spin_lock_bh(rt_hash_lock_addr(i));
+#ifdef CONFIG_NET_NS
+ {
+ struct rtable ** prev, * p;
+
+ rth = rt_hash_table[i].chain;
+
+ /* defer releasing the head of the list after spin_unlock */
+ for (tail = rth; tail; tail = tail->u.dst.rt_next)
+ if (!rt_is_expired(tail))
+ break;
+ if (rth != tail)
+ rt_hash_table[i].chain = tail;
+
+ /* call rt_free on entries after the tail requiring flush */
+ prev = &rt_hash_table[i].chain;
+ for (p = *prev; p; p = next) {
+ next = p->u.dst.rt_next;
+ if (!rt_is_expired(p)) {
+ prev = &p->u.dst.rt_next;
+ } else {
+ *prev = next;
+ rt_free(p);
+ }
+ }
+ }
+#else
rth = rt_hash_table[i].chain;
rt_hash_table[i].chain = NULL;
+ tail = NULL;
+#endif
spin_unlock_bh(rt_hash_lock_addr(i));
- for (; rth; rth = next) {
+ for (; rth != tail; rth = next) {
next = rth->u.dst.rt_next;
rt_free(rth);
}