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| author |   Kirill Tkhai <ktkhai@virtuozzo.com> | 2018-03-30 19:38:37 +0300 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2018-03-31 22:24:58 -0400 |
| commit | 554873e517115c4b7207259f1cadfd77d90b5395 (patch) | |
| tree | bc6dd02f1ba8878c6fd3ecb8ce86e1f0d6fdb4c9 /net/core/net_namespace.c | |
| parent | net: Remove net_rwsem from {, un}register_netdevice_notifier() (diff) | |
| download | linux-dev-554873e517115c4b7207259f1cadfd77d90b5395.tar.xz linux-dev-554873e517115c4b7207259f1cadfd77d90b5395.zip | |
net: Do not take net_rwsem in __rtnl_link_unregister()
This function calls call_netdevice_notifier(), which also
may take net_rwsem. So, we can't use net_rwsem here.
This patch makes callers of this functions take pernet_ops_rwsem,
like register_netdevice_notifier() does. This will protect
the modifications of net_namespace_list, and allows notifiers
to take it (they won't have to care about context).
Since __rtnl_link_unregister() is used on module load
and unload (which are not frequent operations), this looks
for me better, than make all call_netdevice_notifier()
always executing in "protected net_namespace_list" context.
Also, this fixes the problem we had a deal in 328fbe747ad4
"Close race between {un, }register_netdevice_notifier and ...",
and guarantees __rtnl_link_unregister() does not skip
exitting net.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
| -rw-r--r-- | net/core/net_namespace.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 7fdf321d4997..a11e03f920d3 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -51,6 +51,7 @@ static bool init_net_initialized; * outside. */ DECLARE_RWSEM(pernet_ops_rwsem); +EXPORT_SYMBOL_GPL(pernet_ops_rwsem); #define MIN_PERNET_OPS_ID \ ((sizeof(struct net_generic) + sizeof(void *) - 1) / sizeof(void *)) |