From: Eric Dumazet <edumazet@google.com>
Date: Mon, 29 Apr 2024 18:36:43 +0000 (+0000)
Subject: ipv6: anycast: use call_rcu_hurry() in aca_put()
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=fff6e6accdb71e5dd36e50478bd82d5409ac32d2;p=linux.git

ipv6: anycast: use call_rcu_hurry() in aca_put()

This is a followup of commit b5327b9a300e ("ipv6: use
call_rcu_hurry() in fib6_info_release()").

I had another pmtu.sh failure, and found another lazy
call_rcu() causing this failure.

aca_free_rcu() calls fib6_info_release() which releases
devices references.

We must not delay it too much or risk unregister_netdevice/ref_tracker
traces because references to netdev are not released in time.

This should speedup device/netns dismantles when CONFIG_RCU_LAZY=y

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c
index 0f2506e353592..0627c4c18d1a5 100644
--- a/net/ipv6/anycast.c
+++ b/net/ipv6/anycast.c
@@ -252,9 +252,8 @@ static void aca_free_rcu(struct rcu_head *h)
 
 static void aca_put(struct ifacaddr6 *ac)
 {
-	if (refcount_dec_and_test(&ac->aca_refcnt)) {
-		call_rcu(&ac->rcu, aca_free_rcu);
-	}
+	if (refcount_dec_and_test(&ac->aca_refcnt))
+		call_rcu_hurry(&ac->rcu, aca_free_rcu);
 }
 
 static struct ifacaddr6 *aca_alloc(struct fib6_info *f6i,