[PATCH] xfsprogs: add btrfs detection to libdisk

[Christoph Hellwig]

On Thu, Jan 08, 2009 at 12:13:23PM -0600, Eric Sandeen wrote:
> Now that the btrfs disk format has stabilized, libdisk can
> recognize it and mkfs.xfs will not overwrite it w/o "-f" :
> 
> # mkfs.btrfs -l 16384 -L mylabel -n 8192 -s 4096 /tmp/fsfile 
> fs created label mylabel on /tmp/fsfile
>         nodesize 8192 leafsize 16384 sectorsize 4096 size 1.28GB
> Btrfs v0.16-37-gb8271dc
> # mkfs.xfs /tmp/fsfile 
> mkfs.xfs: /tmp/fsfile appears to contain an existing filesystem (btrfs).
> mkfs.xfs: Use the -f option to force overwrite.

Looks good.