it to get better hashing in vfs_hash.
In case of an insert collision in vfs_hash_insert(), put the loosing vnode
on a special list so that vfs_hash_remove() can just assume that it is on
a list.
Drop the VI_HASHED flag.
to get from (mount + inode) to vnode. These tables are mostly
copy&pasted from UFS, sized based on desiredvnodes and therefore
quite large (128K-512K). Several filesystems are buggy enough that
they allocate the hash table even before they know if they will
ever be used or not.
Add "vfs_hash", a system wide hash table, which will replace all
the per-filesystem hash-tables.
The fields we add to struct vnode will more or less be saved in
the respective filesystems inodes.
Having one central implementation will save code and will allow us
to justify the complexity of code to dynamically (re)size the hash
at a later point.
