chs 4ce2757928 strengthen the assertions about pages existing during block allocation,
which were incorrectly relaxed last year.  add some comments so that
the intent of these is hopefully clearer.

in ufs_balloc_range(), don't free pages or mark them dirty if
allocating their backing store failed.  this fixes PR 45369.
2011-09-20 14:01:32 +00:00
..