Re: [PATCH v3 2/6] btrfs-progs: utils: Introduce basic set operations for range

[Qu Wenruo <quwenruo@cn.fujitsu.com>]

At 01/24/2017 01:28 AM, David Sterba wrote:
> On Mon, Dec 19, 2016 at 02:56:38PM +0800, Qu Wenruo wrote:
>> Introduce basic set operations: is_subset() and is_intersection().
>>
>> This is quite useful to check if a range [start, start + len) subset or
>> intersection of another range.
>> So we don't need to use open code to do it, which I sometimes do it
>> wrong.
>>
>> Also use these new facilities in btrfs-convert, to check if a range is a
>> subset or intersects with btrfs convert reserved ranges.
>
> I see the range helpers used only inside convert so I don't think we
> need to export them into utils. Then you could introduce a helper
> structure with start and len members and use that instead of 2 arrays

Right, I could move it convert.

>
>> --- a/disk-io.h
>> +++ b/disk-io.h
>> @@ -97,11 +97,16 @@ enum btrfs_read_sb_flags {
>>  	SBREAD_PARTIAL		= (1 << 1),
>>  };
>>
>> +/*
>> + * Use macro to define mirror super block position
>> + * So we can use it in static array initializtion
>> + */
>> +#define BTRFS_SB_MIRROR_OFFSET(mirror)	((u64)(16 * 1024) << \
>> +					 (BTRFS_SUPER_MIRROR_SHIFT * (mirror)))
>
> This is unrelated change and should go separately.

OK, I can send out a patch first.

Thanks for reviewing,
Qu

>
>>  static inline u64 btrfs_sb_offset(int mirror)
>>  {
>> -	u64 start = 16 * 1024;
>>  	if (mirror)
>> -		return start << (BTRFS_SUPER_MIRROR_SHIFT * mirror);
>> +		return BTRFS_SB_MIRROR_OFFSET(mirror);
>>  	return BTRFS_SUPER_INFO_OFFSET;
>>  }
>>
>
>