This is a rather messy diff resulting from my attempt at making our watermark handling more robust, and especially more suitable for the atomic age. I'll have to work on splitting the diff into some more sensible pieces, but I would appreciate some early comments on the general approach. But for that, it's possibly better to look at the resulting code [1] rather than the crappy diff. [1] git://gitorious.org/vsyrjala/linux.git watermark2
