Re: [PATCH] ext4: delete redundant calculations in ext4_mb_get_buddy_page_lock()

Gou Hao
2023-10-24T02:36:04Z

On 10/23/23 19:44, Jan Kara wrote:

> On Mon 23-10-23 09:34:16, Gou Hao wrote:
>> 'blocks_per_page' is always 1 after 'if (blocks_per_page >= 2)',
>> 'pnum' and 'block' is equal in this case.
>>
>> Signed-off-by: Gou Hao <gouhao@uniontech.com>
>> Signed-off-by: Gou Hao <gouhaojake@163.com>
> No need for two signed-off-by here. Any one from you is enough :)
ok
>> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
>> index 454d5612641e..8442f5474b25 100644
>> --- a/fs/ext4/mballoc.c
>> +++ b/fs/ext4/mballoc.c
>> @@ -1456,9 +1456,7 @@ static int ext4_mb_get_buddy_page_lock(struct super_block *sb,
>> return 0;
>> }
>>
>> - block++;
>> - pnum = block / blocks_per_page;
>> - page = find_or_create_page(inode->i_mapping, pnum, gfp);
>> + page = find_or_create_page(inode->i_mapping, ++block, gfp);
> ^^^ perhaps just
> "block + 1" here? Maybe also add a comment before this call like:

Yes, 'block +1' is better here, i will add a comment.

Thanks for your review.

> /* blocks_per_page == 1, hence we need another page for the buddy */
>
> Otherwise the patch looks good!
>
> Honza
>
--
thanks,
Gou Hao <gouhao@uniontech.com>