Re: [PATCH v2] btrfs: Turn fs_info member buffer_radix into XArray

[Gabriel Niebler <gniebler@suse.com>]

Am 29.04.22 um 20:39 schrieb David Sterba:
> On Fri, Apr 29, 2022 at 05:14:15PM +0300, Nikolay Borisov wrote:
>>> -		cur = gang[ret - 1]->start + gang[ret - 1]->len;
>>>    	}
>>
>> nit: The body of the loop can be turned into:
>>
>> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
>> index da3d9dc186cd..7c1d5fec59dd 100644
>> --- a/fs/btrfs/extent_io.c
>> +++ b/fs/btrfs/extent_io.c
>> @@ -7318,16 +7318,13 @@ static struct extent_buffer *get_next_extent_buffer(
>>
>>           xa_for_each_start(&fs_info->extent_buffers, index, eb,
>>                             page_start >> fs_info->sectorsize_bits) {
>> -               if (eb->start >= page_start + PAGE_SIZE)
>> +               if (in_range(eb->start, page_start, PAGE_SIZE))
>> +                       return eb;
>> +               else if (eb->start >= page_start + PAGE_SIZE)
>>                           /* Already beyond page end */
>> -                       break;
>> -               if (eb->start >= bytenr) {
>> -                       /* Found one */
>> -                       found = eb;
>> -                       break;
>> -               }
>> +                       return NULL;
>>           }
>> -       return found;
>> +       return NULL;
>>    }
>>
>>
>> That is use the in_range macro to detect when we have an eb between
>> page_start and page_start + PAGE_SIZE in which case we can directly
>> return it, and the in_range is self-documenting. And directly return
>> NULL in case of eb->start going beyond the current page and in case we
>> didn't find anything.  David, what do you think?
> 
> I like it and folded to the patch, thanks. The variable 'found' becomes
> unused so removed as well.

Nice! I didn't know there was such a macro - learned something again.

Thank you both!