Re: [PATCH] ext4: invalidate gap cache when writing extents last block

[Kazuya Mio <k-mio@sx.jp.nec.com>]

Hi Lukas,
How do you think about my comment?

Regards,
Kazuya Mio

2011/05/13 17:55, Kazuya Mio wrote:
> 2011/05/13 15:36, Lukas Czerner wrote:
>> That is because due to defensive programming we planted a lot of
>> BUG_ON's to prevent the length of the gap cache to be zero, but in this
>> case it actually will be zero, because there will be no gap at the end
>> of the file.
> 
> Um, I think there is a block (blocksize -1 byte) in gap.
> And this gap should be used for the next block searching.
> According to ext4_ext_in_cache(), len=0 means the special case
> which we have no cache extent, so len=0 should be disallowed.
> 
> Moreover, if we create the file which has 2^32-1 offset,
> we can't get extent which starts from this offset with FIEMAP ioctl.
> That's why I think the maximum file size should be 2^32-1 * blocksize.
> 
> Regards,
> Kazuya Mio