Re: [Intel-wired-lan] [PATCH net v2 1/2] i40e: drop udp_tunnel_get_rx_info() call from i40e_open()

[Paolo Abeni <pabeni@redhat.com>]

On 12/18/25 1:13 PM, mheib@redhat.com wrote:
> From: Mohammad Heib <mheib@redhat.com>
> 
> The i40e driver calls udp_tunnel_get_rx_info() during i40e_open().
> This is redundant because UDP tunnel RX offload state is preserved
> across device down/up cycles. The udp_tunnel core handles
> synchronization automatically when required.
> 
> Furthermore, recent changes in the udp_tunnel infrastructure require
> querying RX info while holding the udp_tunnel lock. Calling it
> directly from the ndo_open path violates this requirement,
> triggering the following lockdep warning:
> 
>   Call Trace:
>    <TASK>
>    ? __udp_tunnel_nic_assert_locked+0x39/0x40 [udp_tunnel]
>    i40e_open+0x135/0x14f [i40e]
>    __dev_open+0x121/0x2e0
>    __dev_change_flags+0x227/0x270
>    dev_change_flags+0x3d/0xb0
>    devinet_ioctl+0x56f/0x860
>    sock_do_ioctl+0x7b/0x130
>    __x64_sys_ioctl+0x91/0xd0
>    do_syscall_64+0x90/0x170
>    ...
>    </TASK>
> 
> Remove the redundant and unsafe call to udp_tunnel_get_rx_info() from
> i40e_open() resolve the locking violation.
> 
> Fixes: 06a5f7f167c5 ("i40e: Move all UDP port notifiers to single function")
> Signed-off-by: Mohammad Heib <mheib@redhat.com>
> Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>

@Tony: I assume you prefer to take this series into your tree first.

@Mohammad: I think we don't need to packport this path in old kernels; I
guess a better fixes tag should point to the recent udp_tunnel
infrastructure changes.

Thanks,

Paolo