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author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2016-08-15 18:48:40 +0300 |
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committer | David S. Miller <davem@davemloft.net> | 2016-08-15 23:48:07 +0300 |
commit | d072218f214929194db06069564495b6b9fff34a (patch) | |
tree | 241e9aba5d342b0fb14f089f9446fdbc9cd31182 /MAINTAINERS | |
parent | f9a7da9130ef0143eb900794c7863dc5c9051fbc (diff) | |
download | linux-d072218f214929194db06069564495b6b9fff34a.tar.xz |
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 'MAINTAINERS')
0 files changed, 0 insertions, 0 deletions