Well, it means the same thing as usual. Here, it is just an abbreviation of the phrase.
If I don't manage to finish my module writing, I'll have to put my nose to the grindstone, (it will be necessary for me to bear down, concentrate on the module writing, and get it done).
One might also punctuate it like this: If not, it's "nose to the grindstone" for me.
EDIT: Sorry, GG, I.was writing at the same time...but taking longer.