[PATCH, RFC] mkfs.xfs: go into multidisk mode when geometry is on cmdline

[Ben Myers]

On Tue, Nov 20, 2012 at 10:34:29AM -0600, Eric Sandeen wrote:
> In the course of some other investigations, I found that 
> calc_default_ag_geometry() doesn't go into "multidisk" mode
> unless stripe geometry is *detected* (i.e. by the blkid routines).
> 
> Specifying a geometry on the cmdline is *not* sufficient, because
> we test (ft.dsunit | ft.dswidth) which are not set by the cmdline
> options.
> 
> If we move the AG calculations to after we have set dsunit & dswdith,
> then we'll pick up either cmdline-specified or blkid-detected
> geometry, and go into "multidisk" mode for AG size/count
> calculations in both cases.
> 
> So now for a ~5T fs, for example, we'd make several more
> AGs:
> 
> # truncate --size=5t fsfile
> # mkfs.xfs -N -d su=128k,sw=8 fsfile | grep agcount
> meta-data=fsfile                 isize=256    agcount=5, agsize=268435424 blks
> # mkfs/mkfs.xfs -N -d su=128k,sw=8 fsfile | grep agcount
> meta-data=fsfile                 isize=256    agcount=32, agsize=41943008 blks
> 
> Signed-off-by: Eric Sandeen <sandeen at redhat.com>

V3 of patch 1 and patch 2 have been committed to repos on oss.sgi.com