Ja .. es gibt nen grub Patch für Reiserfs4 !
Guck mal hier -> http://thebsh.namesys.com/install_v4.html
"How to enable the grub support for reiser4?
1. Install libaal-stand-alone and libreiser4-stand-alone libraries as described above.
2. Obtain the grub tarball from http://www.gnu.org/software/grub/grub.html and the reiser4 patch for the grub on ftp://ftp.namesys.com/pub/reiser4progs/grub/LATEST
3. Apply the patch, build it. # cd grub # cat grub_patch.diff |patch -p1 # aclocal && autoheader && autoconf && automake --add-missing
The reiser4 support is enabled by default, to disable it the the option of the configure script --disable-reiser4 can be used.
Note: There are a plenty of options in reiser4progs/configure script to decrease the amount of the code in the libreiser4-stand-alone library (see --disable-* options), however the result size of reiser4_stage1_5 in grub does not fit 23,5K size limit now, and probably will not anymore, so stage1_5 reiser4 support in grub does not work -- use stage2 instead.
WARNING: If you already created a reiser4 fs with the mkfs from some previous version of reiser4progs, first of all run
# debugfs.reiser4 -C device
The layout of the super block backups has been changed, this will convert the fs into the new format. After that please check the fs with the
# fsck.reiser4 device
Please report anything you find wrong to reiserfs-dev@namesys.com
Have fun."