[PATCH] nfsd as filesystem

* introduces a new filesystem - nfsd.  No, it's not a typo.  It's a small
  tree with fixed topology defined by nfsd and IO on its files does what
  we used to do by hand in nfsctl.c.
* turns sys_nfsservctl() into a sequence of open()/write()/read()/close()
  It works as it used to - we don't need nfsd to be mounted anywhere, etc.
* nfsd_linkage ugliness is gone.
* getfs and getfh demonstrate (rather trivial) example of "descriptor as
  transaction descriptor" behaviour.
* we are fairly close to the situation when driver-defined filesystems can
  be done with practically zero code overhead.  We are still not there, but
  it's a matter of adding a couple of helpers for populating the tree.

	One thing we get immediately is a cleanup of sys_nfsservctl() -
it got _much_ better.  Moreover, we get an alternative interface that
uses normal file IO and can be used without magic syscalls.

1 files changed, 5 insertions, 34 deletions

diff --git a/fs/filesystems.c b/fs/filesystems.c
index a465ff2dc0bf..76eda773d051 100644
--- a/fs/filesystems.c
+++ b/fs/filesystems.c
@@ -3,39 +3,10 @@
  *
  *  Copyright (C) 1991, 1992  Linus Torvalds
  *
- *  nfsservctl system-call when nfsd is not compiled in.
+ *  table of configured filesystems
  */
 
-#include <linux/config.h>
-#include <linux/module.h>
-#include <linux/time.h>
-#include <linux/smp_lock.h>
-#include <linux/kmod.h>
-#include <linux/nfsd/interface.h>
-#include <linux/linkage.h>
-
-#if ! defined(CONFIG_NFSD)
-struct nfsd_linkage *nfsd_linkage;
-
-long
-asmlinkage sys_nfsservctl(int cmd, void *argp, void *resp)
-{
-	int ret = -ENOSYS;
-	
-#if defined(CONFIG_MODULES)
-	lock_kernel();
-
-	if (nfsd_linkage ||
-	    (request_module ("nfsd") == 0 && nfsd_linkage)) {
-		__MOD_INC_USE_COUNT(nfsd_linkage->owner);
-		unlock_kernel();
-		ret = nfsd_linkage->do_nfsservctl(cmd, argp, resp);
-		__MOD_DEC_USE_COUNT(nfsd_linkage->owner);
-	} else
-		unlock_kernel();
-#endif
-	return ret;
-}
-EXPORT_SYMBOL(nfsd_linkage);
-
-#endif /* CONFIG_NFSD */
+/*
+ * Code will move here from fs/super.c and yes, it will be fs type handling
+ * stuff.
+ */