Re: [PATCH v3 1/6] fat: add i_disksize to represent uninitialized size

[OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>]

Namjae Jeon <linkinjeon@gmail.com> writes:

> 2014-02-03, OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>:
>> Namjae Jeon <linkinjeon@gmail.com> writes:
>>
>>> From: Namjae Jeon <namjae.jeon@samsung.com>
>>>
>>> Add i_disksize to represent uninitialized allocated size.
>>> And mmu_private represent initialized allocated size.
>>
>> Don't we need to update ->i_disksize after cont_write_begin()?
> We don't need to update i_disksize after cont_write_begin.
> It is taken care by the fat_get_block after the allocation.
> For all write paths we align the mmu_private and i_disksize from
> fat_fill_inode and fat_get_block.

fat_fill_inode() just set i_disksize to i_size. So, it is not aligned by
cluster size or block size.

E.g. ->mmu_private = 500. Then, cont_write_begin() can set ->mmu_private
to 512 on some case. In this case, fat_get_block() will not be called,
because no new allocation.

If this is true, it would be possible to have ->mmu_private == 512 and
->i_disksize == 500. 

I'm missing something?

Thanks.
-- 
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>