From: Kirill Tkhai <ktkhai@virtuozzo.com>
Date: Tue, 16 Jan 2018 09:31:54 +0000 (+0300)
Subject: net: Remove spinlock from get_net_ns_by_id()
X-Git-Tag: v4.16-rc1~123^2~136
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=42157277af17d5c05946c700eb03877d60760d3c;p=linux.git

net: Remove spinlock from get_net_ns_by_id()

idr_find() is safe under rcu_read_lock() and
maybe_get_net() guarantees that net is alive.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 3c77d84ad60d..1ccb953b3b09 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -273,11 +273,9 @@ struct net *get_net_ns_by_id(struct net *net, int id)
 		return NULL;
 
 	rcu_read_lock();
-	spin_lock_bh(&net->nsid_lock);
 	peer = idr_find(&net->netns_ids, id);
 	if (peer)
 		peer = maybe_get_net(peer);
-	spin_unlock_bh(&net->nsid_lock);
 	rcu_read_unlock();
 
 	return peer;