Expanding vops in vop_vectors during startup

[Ed Schouten]

Hello everyone,

Yesterday I was talking with some friends of mine about the FreeBSD VFS
layer. As an exercise, Jille was trying to patch nullfs to hide .svn
directories (see hackers@), so that's how we got to the subject.

After talking about the way our vop_vector works (vop_bypass and
vop_default), we were wondering why we don't propagate all pointers in
the vop_vector to its children to save the unneeded function pointer
resolving inside the VOP_* calls.

I've created a patch that adds a new routine to the kernel,
vop_vector_init(), which recursively expands the vops. A new macro
(DECLARE_VOP_VECTOR) is used to automatically perform this when loading
modules/booting.

There is no need to reference default_vnodeops anymore, because it is
now used implicitly (when vop_vector == NULL).

Any comments on the attached patch? I've only tested it with ufs,
nullfs, devfs, etc. yet. I haven't tested `make universe' yet, but I
suspect it shouldn't break hard.

URL:

	http://80386.nl/files/vnode-vop-expand.diff

Thanks!

-- 
 Ed Schouten <ed at 80386.nl>
 WWW: http://80386.nl/
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