While touching all vptofh/fhtovp functions, get rid of VFS_MAXFIDSIZ,
version the getfh(2) syscall and explicitly pass the size available in
the filehandle from userland.
Discussed on tech-kern, with lots of help from yamt (thanks!).
In determining when to stop reading segments when counting bytes (-b flag),
total the sizes of the blocks we're actually writing instead of assuming
they are all full blocks: many could be fragments or inode blocks. This
increases the number of segments per Ifile write, markedly improving the
efficiency of the cleaner in the small file case.
cleaner, but with more legible code.
Includes code for reading and writing to the raw disk device (so that an
unmounted fs could be cleaned), for the use of a single daemon to clean
multiple filesystems to save on resources, and for recording the old
contents of cleaned segments to offline storage for regression testing of
the LFS system as a whole; though these new features are not properly
tested at this point.
