Re: Initial results of FLEX_BG feature.

["Jose R. Santos" <jrs@us.ibm.com>]

On Mon, 16 Jul 2007 00:34:57 -0600
Andreas Dilger <adilger@clusterfs.com> wrote:

> On Jul 12, 2007  10:09 -0500, Jose R. Santos wrote:
> > @@ -1271,6 +1271,9 @@ static int ext4_check_descriptors (struc
> >  
> >  	ext4_debug ("Checking group descriptors");
> >  
> > +	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
> > +		return 1;
> > +
> >  	for (i = 0; i < sbi->s_groups_count; i++)
> >  	{
> >  		if (i == sbi->s_groups_count - 1)
> 
> It looks pretty straight forward to just change this code to leave
> first_block at s_first_data_block, and leave last_block at ext4_blocks_count()
> if FLEX_BG is set.

Sure.  I'll add that.
 
> Even with FLEX_BG we want to keep the group metadata within the bounds of
> the filesystem.

Eventually, I want to be able to export the groups per flex groups so
that we can correctly calculate where the bounds of each block groups
metadata should be.

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

-JRS