diff options
| author |   Neil Horman <nhorman@tuxdriver.com> | 2013-02-11 10:25:30 +0000 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2013-02-11 19:19:33 -0500 |
| commit | 2cde6acd49daca58b96f1fbc697492825511ad31 (patch) | |
| tree | 77353244a904fbb41e8658cceedb4b5120c5552a /include | |
| parent | skbuff: create skb_panic() function and its wrappers (diff) | |
| download | linux-dev-2cde6acd49daca58b96f1fbc697492825511ad31.tar.xz linux-dev-2cde6acd49daca58b96f1fbc697492825511ad31.zip | |
netpoll: Fix __netpoll_rcu_free so that it can hold the rtnl lock
__netpoll_rcu_free is used to free netpoll structures when the rtnl_lock is
already held. The mechanism is used to asynchronously call __netpoll_cleanup
outside of the holding of the rtnl_lock, so as to avoid deadlock.
Unfortunately, __netpoll_cleanup modifies pointers (dev->np), which means the
rtnl_lock must be held while calling it. Further, it cannot be held, because
rcu callbacks may be issued in softirq contexts, which cannot sleep.
Fix this by converting the rcu callback to a work queue that is guaranteed to
get scheduled in process context, so that we can hold the rtnl properly while
calling __netpoll_cleanup
Tested successfully by myself.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Cong Wang <amwang@redhat.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/netpoll.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h index ab856d507b7e..9d7d8c64f7c8 100644 --- a/include/linux/netpoll.h +++ b/include/linux/netpoll.h @@ -32,7 +32,7 @@ struct netpoll { u8 remote_mac[ETH_ALEN]; struct list_head rx; /* rx_np list element */ - struct rcu_head rcu; + struct work_struct cleanup_work; }; struct netpoll_info { @@ -68,7 +68,7 @@ int netpoll_setup(struct netpoll *np); int netpoll_trap(void); void netpoll_set_trap(int trap); void __netpoll_cleanup(struct netpoll *np); -void __netpoll_free_rcu(struct netpoll *np); +void __netpoll_free_async(struct netpoll *np); void netpoll_cleanup(struct netpoll *np); int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo); void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb, |