Re: [PATCH] VFS autmounter support v3

On Fri, Jun 20, 2003 at 05:17:16PM +0100, David Howells wrote:
 
>  (2) Automatic mount point expiry. This allows any mountpoint to be given a
>      timeout, such that when mntput() detects that the vfsmount is only used
>      by its parent, a work chitty will be enqueued to cause the containing
>      namespace to be vacuumed later for dead mounts.

Broken.
	a) it doesn't scale.  A single expirable mountpoint and we will be
walking potentially very long list.
	b) the logics is wrong - you are scheduling "let's go and expire
stuff" when ->mnt_count drops far enough; put something like /usr/share
on a separate fs and observe what happens to ->mnt_count.  It will touch
the trigger value very often.  Better yet, do that with /usr/include and
start a big build.  You will have your expiry code triggered all the time,
even though fs is in very active use.