[PATCH rcu/dev 3/3] net: Use call_rcu_flush() for dst_destroy_rcu

From: Joel Fernandes (Google)
Date: Wed Nov 16 2022 - 22:16:20 EST


In a networking test on ChromeOS, we find that using the new CONFIG_RCU_LAZY
causes a networking test to fail in the teardown phase.

The failure happens during: ip netns del <name>

Using ftrace, I found the callbacks it was queuing which this series fixes. Use
call_rcu_flush() to revert to the old behavior. With that, the test passes.

Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
---
net/core/dst.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/dst.c b/net/core/dst.c
index bc9c9be4e080..15b16322703f 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -174,7 +174,7 @@ void dst_release(struct dst_entry *dst)
net_warn_ratelimited("%s: dst:%p refcnt:%d\n",
__func__, dst, newrefcnt);
if (!newrefcnt)
- call_rcu(&dst->rcu_head, dst_destroy_rcu);
+ call_rcu_flush(&dst->rcu_head, dst_destroy_rcu);
}
}
EXPORT_SYMBOL(dst_release);
--
2.38.1.584.g0f3c55d4c2-goog