Re: [PATCH net 0/2] bond: fix xfrm offload feature during init

Jianbo Liu
2025-01-08T03:40:33Z

On 1/8/2025 10:46 AM, Hangbin Liu wrote:
> On Mon, Jan 06, 2025 at 10:47:16AM +0000, Hangbin Liu wrote:
>> On Thu, Jan 02, 2025 at 11:33:34AM +0800, Jianbo Liu wrote:
>>>>> Re-locking doesn't look great, glancing at the code I don't see any
>>>>> obvious better workarounds. Easiest fix would be to don't let the
>>>>> drivers sleep in the callbacks and then we can go back to a spin lock.
>>>>> Maybe nvidia people have better ideas, I'm not familiar with this
>>>>> offload.
>>>>
>>>> I don't know how to disable bonding sleeping since we use mutex_lock now.
>>>> Hi Jianbo, do you have any idea?
>>>>
>>>
>>> I think we should allow drivers to sleep in the callbacks. So, maybe it's
>>> better to move driver's xdo_dev_state_delete out of state's spin lock.
>>
>> I just check the code, xfrm_dev_state_delete() and later
>> dev->xfrmdev_ops->xdo_dev_state_delete(x) have too many xfrm_state x
>> checks. Can we really move it out of spin lock from xfrm_state_delete()
>
> I tried to move the mutex lock code to a work queue, but found we need to
> check (ipsec->xs == xs) in bonding. So we still need xfrm_state x during bond

Maybe I miss something, but why need to hold spin lock. You can keep
xfrm state by its refcnt.

> ipsec gc.
>
> So either we add a new lock for xfrm_state, or we need to unlock spin lock in
> bonding bond_ipsec_del_sa().
>
> Cc IPsec experts to see if they have any comments.
>
> Background: The xfrm_dev_state_delete() in xfrm_state_delete() is protected
> by spin lock. But the driver delete ops dev->xfrmdev_ops->xdo_dev_state_delete(x)
> may sleep, e.g. bond_ipsec_del_sa(). What we should deal with this issue?
>
> Thanks
> Hangbin