Re: [PATCH] vfs: Fix vmtruncate() regression

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

Nick Piggin <npiggin@suse.de> writes:

>> If __block_prepare_write() was failed in block_write_begin(), the
>> allocated blocks can be outside of ->i_size.
>> 
>> But new truncate_pagecache() in vmtuncate() does nothing if new < old.
>> It means the above usage is not working anymore.
>> 
>> So, this patch fixes it by removing "new < old" check. It would need
>> more cleanup/change. But, now -rc and truncate working is in progress,
>> so, this tried to fix it minimum change.
>> 
>> Cc: stable@kernel.org
>> Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
>
> Hmm, truncate_pagecache() is for truncating the mm/vm part of the
> pagecache. vmtruncate should still call inode->i_op->truncate() to
> trim blocks if required.
>
> However I'd say we do still need to ensure do_invalidatepage is
> called for the page, for private metadata. So yes I think your patch
> looks good.

Thanks for reviewing. Yes, and it also needs to be called to ensure that
have the same state on-disk and page/bh state. [BTW, this became the
cause of fatfs corruption.]

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