Re: [RFC] Ext3 online defrag

[Andreas Dilger <adilger@clusterfs.com>]

On Oct 25, 2006  16:54 +0200, Jan Kara wrote:
> I've just not yet decided how to handle indirect
> blocks in case of relocation in the middle of the file. Should they be
> relocated or shouldn't they? Probably they should be relocated at least
> in case they are fully contained in relocated interval or maybe better
> said when all the blocks they reference to are also in the interval
> (this handles also the case of EOF). But still if you would like to
> relocate the file by parts this is not quite what you want (you won't be
> able to relocate indirect blocks in the boundary of intervals) :(.

I suspect that the natural choice for metadata blocks is to keep the
block which has the most metadata unchanged.  For example, if you are
doing a full-file relocation then you would naturally keep all of the
new {dt}indirect blocks.  If you are relocating a small chunk of the
file you would keep the old {dt}indirect blocks and just copy a few
block pointers over.

Cheers, Andreas
--
Andreas Dilger
Principal Software Engineer
Cluster File Systems, Inc.