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SubjectRe: drivers/block/rbd.c: atomic_inc_return_safe() & atomic_dec_return_safe()
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On 10/2/20 5:44 PM, Jens Axboe wrote:
> On 10/2/20 4:34 PM, Shuah Khan wrote:
>> All,
>>
>> I came across these atomic_inc_return_safe() & atomic_dec_return_safe()
>> functions that hold the counters at safe values.
>>
>> atomic_inc_return_safe()
>>
>> If the counter is already 0 it will not be incremented.
>> If the counter is already at its maximum value returns
>> -EINVAL without updating it.
>>
>> atomic_dec_return_safe()
>>
>> Decrement the counter. Return the resulting value, or -EINVAL
>>
>> These two routines are static and only used in rbd.c.
>>
>> Can these become part of atomic_t ops?
>
> I think you just want to use refcount_t for this use case. They
> have safe guards for under/overflow.
>

Makes sense. Guess these came before refcount_t.

I will track this for refcount_t conversion.

thanks,
-- Shuah

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