Re: fixing the vnode lifecycle

[David Holland <dholland-tech%netbsd.org@localhost>]

On Sun, Sep 22, 2013 at 03:28:58AM +0000, David Holland wrote:
 > So, here's some thinking out loud on the subject of fixing it.
 >    :
 > (I also have no real idea yet how to get to where I'm describing from
 > where we are in a decently incremental fashion.)

I think the first step forward on that is to move the ufs_icache code
to kern/ and generalize it where needed (not much I think) so other
fses can use it, then convert the other fses one by one.

Another model entirely, on the other hand, is to get rid of the
vfs-level vnode cache and make each fs fully responsible for its own
vnodes. This can also get rid of a lot of the mess; the problem then
is that there's no obvious way to control how many inodes each fs is
allowed to keep live. (And also it promotes C&P code, replicated bugs,
and so on, which is why I don't think it's a good idea.)

-- 
David A. Holland
dholland%netbsd.org@localhost