[Devel] [RFC PATCH vz9 v6 08/62] dm-ploop: convert enospc handling to use lockless lists

[Alexander Atanasov]

On 9.01.25 9:15, Pavel Tikhomirov wrote:
> 
>> @@ -177,10 +180,9 @@ static bool ploop_try_delay_enospc(struct 
>> ploop_rq *prq, struct pio *pio)
>>       pr_err_once(PL_FMT("underlying disk is almost full"),
>>           ploop_device_name(ploop));
>> -    ploop->event_enospc = true;
>> -    list_add_tail(&pio->list, &ploop->enospc_pios);
>> +    WRITE_ONCE(ploop->event_enospc, true);
> 
> Do we still need deferred_lock in ploop_get_event to protect 
> event_enospc after this? Probably we can also use READ/WRITE_ONCE there.

Yes, it does test and set, so it needs a lock.
I also restored the lock here , otherwise a event can be missed.
I will rework it when i rework the timer.
Events are better delivered via queue.


-- 
Regards,
Alexander Atanasov