Re: xfs_fsr allocation group optimization

[Johan Andersson <johan@e-626.net>]

On Mon, 2007-06-11 at 02:01 -0700, Chris Wedgwood wrote:
> using "find .... xfs_fsr" you get temporary files in the same AG as
> the file your are defragmenting, avoiding the spreading out effect,
> but this might not be the least-defragmented file you can get
> 
> what's really needed is an attempt to find space near the original
> file if possible and if not then an option to try harder looking in
> other AGs
This is exactly what the simple but ugly patch I attached achieves by
looking up the filename of the inode it defrags when doing a full file
system defrag. And it works well, except that it spends a lot of time
finding that file name. As I said, a better option would be if you could
tell XFS in what AG you want extents for a newly created file to place
it's extents in. 

/Johan Andersson