Messages in this thread | | | From | OGAWA Hirofumi <> | Subject | Re: [PATCH v3 1/6] fat: add i_disksize to represent uninitialized size | Date | Thu, 06 Feb 2014 21:18:13 +0900 |
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Namjae Jeon <linkinjeon@gmail.com> writes:
>>> 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? >> >> BTW, even if above was right, I'm not checking whether updating >> ->i_disksize after cont_write_begin() is right fix or not. > I understand your concern. these can be mismatched. But, when > checking your doubt, I can not find any side effect. I think that > there is no issue regardless of alignment of two value, in the > cont_write_begin. Could you please share any point I am missing ? If > you suggest checking point or test method, I can check more and share > the result.
I'm not checking whether it is wrong or not. But, like you said, ->mmu_private > ->i_disksize is wrong in theory.
Although, it might have no real problem.
So, how about to set ->i_disksize to aligned by blocksize at first (i.e. when initializing the inode)?
This may change the behavior when ->mmu_private is not aligned to blocksize in current patchset. But, in theory, it is right state (between ->mmu_private and ->i_disksize is uninitialized). I guess, we can do it with small adjustments, and keep state valid in theory too.
This is just a my guess, so it might be wrong though. I guess, worth to try to consider.
Thanks. -- OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
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