This second patch (for cosmetic changes) applies incrementally after my 
last LKML'd patch (for 2.5 block layer). These changes are intended to 
help identify code inefficiencies and problems particularly w.r.t. 
locking. It also modifies some of the output messages for greater 
consistancy and better diagnostic support. This second patch is a lead 
in that way to the third patch (coming next), which introduces the 
dprintk() debugging facility that my jumbo patch originally had.

Again, feedback welcome!

PS: Andrew may have already queued this second patch up in -mm but I 
neglected to CC the LKML so here it is for everyone elses benefit.