Re: [PATCH 01/11 RESEND] libe2p: Add new function get_fragment_score()

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

Hi Greg,
I'm sorry for the late reply.

2011/06/23 20:16, Greg Freemyer wrote:
> For a sparse file, can you explain why you treat the head and tail
> extents of a block group differently?

Could you tell me what "block group" you said means?

If "block group" means the ext4 block group, I will treat the head and tail
extents of a block group the same way.

And if "block group" means the chunk of the extents whose offset is continued,
I will treat only the tail extents as a special case.

# filefrag -v /mnt/mp1/file
Filesystem type is: ef53
File size of /mnt/mp1/file is 285212672 (69632 blocks, blocksize 4096)
  ext logical physical expected length flags
    0       0    34816           30720
    1   30720    65536            2048 unwritten
    2   65536    67584            4096 unwritten,eof
/mnt/mp1/file: 1 extent found

The case is not fragmented. The length of #1 extent is a little bit short,
but there is no point in doing defragmentation because of the hole existence.

Regards,
Kazuya Mio