Re: [Qemu-devel] [PATCH] qcow2: Replace align_offset() with ROUND_UP()

[Alberto Garcia]

On Tue 30 Jan 2018 05:17:47 PM CET, Eric Blake wrote:
> On 01/30/2018 10:08 AM, Alberto Garcia wrote:
>> On Tue 30 Jan 2018 05:03:16 PM CET, Eric Blake wrote:
>> 
>>>> -    virtual_size = align_offset(qemu_opt_get_size_del(opts, 
>>>> BLOCK_OPT_SIZE, 0),
>>>> +    virtual_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 
>>>> 0),
>>>>                                  cluster_size);
>> 
>> I just realized that the first parameter here is a function call with
>> side effects, it it safe to use ROUND_UP() in this case?
>> 
>> #define ROUND_UP(n, d) (((n) + (d) - 1) & -(0 ? (n) : (d)))
>
> Oh, good catch.  No, we need a temporary variable to hold the result
> of the function call

...which is what align_offset() was doing in the first place. I can
still modify that function to use the macro internally.

Berto