Removal of miscfs/syncfs

["J. Hannken-Illjes" <hannken%eis.cs.tu-bs.de@localhost>]

Our miscfs/syncfs originating from the softdep import is a pseudo
file system with one VOP.  Its vnodes get used as a kind of marker
on the syncer worklist so the syncer may run lazy VFS_SYNC for
all mounted file systems.

For this to work, it creates a vnode attached to the mount point
with a special (syncfs) operations vector.  This concept breaks
some rules making it nearly is impossible to implement it with
the new vcache operations.

I propose to completely remove miscfs/syncfs and

- move the syncer sched_sync into kern/vfs_subr.c
- change the syncer to process the mountlist and VFS_SYNC as appropriate.
- use an API for mount points similiar to the API for vnodes.

Diff at http://www.netbsd.org/~hannken/rm-miscfs-syncfs-1.diff

Comments or objections anyone?

--
J. Hannken-Illjes - hannken%eis.cs.tu-bs.de@localhost - TU Braunschweig (Germany)