diff options
author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2016-08-15 17:48:40 +0200 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2016-08-15 13:48:07 -0700 |
commit | d072218f214929194db06069564495b6b9fff34a (patch) | |
tree | 241e9aba5d342b0fb14f089f9446fdbc9cd31182 /drivers/net/hyperv/hyperv_net.h | |
parent | f9a7da9130ef0143eb900794c7863dc5c9051fbc (diff) | |
download | linux-d072218f214929194db06069564495b6b9fff34a.tar.bz2 |
hv_netvsc: avoid deadlocks between rtnl lock and vf_use_cnt wait
Here is a deadlock scenario:
- netvsc_vf_up() schedules netvsc_notify_peers() work and quits.
- netvsc_vf_down() runs before netvsc_notify_peers() gets executed. As it
is being executed from netdev notifier chain we hold rtnl lock when we
get here.
- we enter while (atomic_read(&net_device_ctx->vf_use_cnt) != 0) loop and
wait till netvsc_notify_peers() drops vf_use_cnt.
- netvsc_notify_peers() starts on some other CPU but netdev_notify_peers()
will hang on rtnl_lock().
- deadlock!
Instead of introducing additional synchronization I suggest we drop
gwrk.dwrk completely and call NETDEV_NOTIFY_PEERS directly. As we're
acting under rtnl lock this is legitimate.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/hyperv/hyperv_net.h')
-rw-r--r-- | drivers/net/hyperv/hyperv_net.h | 7 |
1 files changed, 0 insertions, 7 deletions
diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h index 3b3ecf237a12..591af71eae56 100644 --- a/drivers/net/hyperv/hyperv_net.h +++ b/drivers/net/hyperv/hyperv_net.h @@ -644,12 +644,6 @@ struct netvsc_reconfig { u32 event; }; -struct garp_wrk { - struct work_struct dwrk; - struct net_device *netdev; - struct net_device_context *net_device_ctx; -}; - /* The context of the netvsc device */ struct net_device_context { /* point back to our device context */ @@ -667,7 +661,6 @@ struct net_device_context { struct work_struct work; u32 msg_enable; /* debug level */ - struct garp_wrk gwrk; struct netvsc_stats __percpu *tx_stats; struct netvsc_stats __percpu *rx_stats; |