Even after applying Henrik's patches, hostfs was still not working for me.
I tracked the problem down to this; I'm not exactly sure why it works this
way (why does it always try to open the file read/write first?), but this
got it working again for me so far.

If this is really the right way to go about this, then it needs to check for
other things as well (EROFS?), but it doesn't seem right...

-- 
 - mdz