Messages in this thread | | | Subject | Re: drivers/block/rbd.c: atomic_inc_return_safe() & atomic_dec_return_safe() | From | Jens Axboe <> | Date | Fri, 2 Oct 2020 17:44:22 -0600 |
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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.
-- Jens Axboe
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