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| author |   Kirill Tkhai <ktkhai@virtuozzo.com> | 2018-03-30 19:38:27 +0300 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2018-03-31 22:24:58 -0400 |
| commit | fc1dd36992bb041b4470120aecf8986910c56088 (patch) | |
| tree | 7fbea89ad406d55660f89abf4f380b7e010b565d | |
| parent | net: hns3: remove unnecessary pci_set_drvdata() and devm_kfree() (diff) | |
| download | linux-dev-fc1dd36992bb041b4470120aecf8986910c56088.tar.xz linux-dev-fc1dd36992bb041b4470120aecf8986910c56088.zip | |
net: Remove net_rwsem from {, un}register_netdevice_notifier()
These functions take net_rwsem, while wireless_nlevent_flush()
also takes it. But down_read() can't be taken recursive,
because of rw_semaphore design, which prevents it to be occupied
by only readers forever.
Since we take pernet_ops_rwsem in {,un}register_netdevice_notifier(),
net list can't change, so these down_read()/up_read() can be removed.
Fixes: f0b07bb151b0 "net: Introduce net_rwsem to protect net_namespace_list"
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/core/dev.c | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 07da7add4845..8edb58829124 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1633,7 +1633,6 @@ int register_netdevice_notifier(struct notifier_block *nb) goto unlock; if (dev_boot_phase) goto unlock; - down_read(&net_rwsem); for_each_net(net) { for_each_netdev(net, dev) { err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev); @@ -1647,7 +1646,6 @@ int register_netdevice_notifier(struct notifier_block *nb) call_netdevice_notifier(nb, NETDEV_UP, dev); } } - up_read(&net_rwsem); unlock: rtnl_unlock(); @@ -1671,7 +1669,6 @@ rollback: } outroll: - up_read(&net_rwsem); raw_notifier_chain_unregister(&netdev_chain, nb); goto unlock; } @@ -1704,7 +1701,6 @@ int unregister_netdevice_notifier(struct notifier_block *nb) if (err) goto unlock; - down_read(&net_rwsem); for_each_net(net) { for_each_netdev(net, dev) { if (dev->flags & IFF_UP) { @@ -1715,7 +1711,6 @@ int unregister_netdevice_notifier(struct notifier_block *nb) call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev); } } - up_read(&net_rwsem); unlock: rtnl_unlock(); up_write(&pernet_ops_rwsem); |