On 28.06.2019 1:04, Jonathan Lemon wrote:
> On 27 Jun 2019, at 3:15, Ilya Maximets wrote:
>
>> Device that bound to XDP socket will not have zero refcount until the
>> userspace application will not close it. This leads to hang inside
>> 'netdev_wait_allrefs()' if device unregistering requested:
>>
>> # ip link del p1
>> < hang on recvmsg on netlink socket >
>>
>> # ps -x | grep ip
>> 5126 pts/0 D+ 0:00 ip link del p1
>>
>> # journalctl -b
>>
>> Jun 05 07:19:16 kernel:
>> unregister_netdevice: waiting for p1 to become free. Usage count = 1
>>
>> Jun 05 07:19:27 kernel:
>> unregister_netdevice: waiting for p1 to become free. Usage count = 1
>> ...
>>
>> Fix that by implementing NETDEV_UNREGISTER event notification handler
>> to properly clean up all the resources and unref device.
>>
>> This should also allow socket killing via ss(8) utility.
>>
>> Fixes: 965a99098443 ("xsk: add support for bind for Rx")
>> Signed-off-by: Ilya Maximets <i.maximets@xxxxxxxxxxx>
>> ---
>> include/net/xdp_sock.h | 5 +++
>> net/xdp/xdp_umem.c | 10 ++---
>> net/xdp/xdp_umem.h | 1 +
>> net/xdp/xsk.c | 87 ++++++++++++++++++++++++++++++++++++------
>> 4 files changed, 87 insertions(+), 16 deletions(-)
>>
>> diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h
>> index d074b6d60f8a..82d153a637c7 100644
>> --- a/include/net/xdp_sock.h
>> +++ b/include/net/xdp_sock.h
>> @@ -61,6 +61,11 @@ struct xdp_sock {
>> struct xsk_queue *tx ____cacheline_aligned_in_smp;
>> struct list_head list;
>> bool zc;
>> + enum {
>> + XSK_UNINITIALIZED = 0,
>> + XSK_BINDED,
>> + XSK_UNBINDED,
>> + } state;
>
> I'd prefer that these were named better, perhaps:
> XSK_READY,
> XSK_BOUND,
> XSK_UNBOUND,
Sure. Thanks for suggestion!
>
> Other than that:
> Acked-by: Jonathan Lemon <jonathan.lemon@xxxxxxxxx>
>
I'll send a new version with the new state names keeping your ACK.
Best regards, Ilya Maximets.
