Revert "netns: don't clear nsid too early on removal"

This reverts
commit 4217291e592d ("netns: don't clear nsid too early on removal").

This is not the right fix, it introduces races.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 15 deletions

diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 5221f975a4cc..cb5290b8c428 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -349,7 +349,7 @@ static LIST_HEAD(cleanup_list);  /* Must hold cleanup_list_lock to touch */
 static void cleanup_net(struct work_struct *work)
 {
         const struct pernet_operations *ops;
-        struct net *net, *tmp, *peer;
+        struct net *net, *tmp;
         struct list_head net_kill_list;
         LIST_HEAD(net_exit_list);
 
@@ -365,6 +365,14 @@ static void cleanup_net(struct work_struct *work)
         list_for_each_entry(net, &net_kill_list, cleanup_list) {
                 list_del_rcu(&net->list);
                 list_add_tail(&net->exit_list, &net_exit_list);
+                for_each_net(tmp) {
+                        int id = __peernet2id(tmp, net, false);
+
+                        if (id >= 0)
+                                idr_remove(&tmp->netns_ids, id);
+                }
+                idr_destroy(&net->netns_ids);
+
         }
         rtnl_unlock();
 
@@ -390,26 +398,12 @@ static void cleanup_net(struct work_struct *work)
          */
         rcu_barrier();
 
-        rtnl_lock();
         /* Finally it is safe to free my network namespace structure */
         list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) {
-                /* Unreference net from all peers (no need to loop over
-                 * net_exit_list because idr_destroy() will be called for each
-                 * element of this list.
-                 */
-                for_each_net(peer) {
-                        int id = __peernet2id(peer, net, false);
-
-                        if (id >= 0)
-                                idr_remove(&peer->netns_ids, id);
-                }
-                idr_destroy(&net->netns_ids);
-
                 list_del_init(&net->exit_list);
                 put_user_ns(net->user_ns);
                 net_drop_ns(net);
         }
-        rtnl_unlock();
 }
 static DECLARE_WORK(net_cleanup_work, cleanup_net);