xref: /src/sys/coda/coda_subr.c

/*	$NetBSD: coda_subr.c,v 1.2 1998/09/08 17:12:47 rvb Exp $	*/

/*
 *
 *             Coda: an Experimental Distributed File System
 *                              Release 3.1
 *
 *           Copyright (c) 1987-1998 Carnegie Mellon University
 *                          All Rights Reserved
 *
 * Permission  to  use, copy, modify and distribute this software and its
 * documentation is hereby granted,  provided  that  both  the  copyright
 * notice  and  this  permission  notice  appear  in  all  copies  of the
 * software, derivative works or  modified  versions,  and  any  portions
 * thereof, and that both notices appear in supporting documentation, and
 * that credit is given to Carnegie Mellon University  in  all  documents
 * and publicity pertaining to direct or indirect use of this code or its
 * derivatives.
 *
 * CODA IS AN EXPERIMENTAL SOFTWARE SYSTEM AND IS  KNOWN  TO  HAVE  BUGS,
 * SOME  OF  WHICH MAY HAVE SERIOUS CONSEQUENCES.  CARNEGIE MELLON ALLOWS
 * FREE USE OF THIS SOFTWARE IN ITS "AS IS" CONDITION.   CARNEGIE  MELLON
 * DISCLAIMS  ANY  LIABILITY  OF  ANY  KIND  FOR  ANY  DAMAGES WHATSOEVER
 * RESULTING DIRECTLY OR INDIRECTLY FROM THE USE OF THIS SOFTWARE  OR  OF
 * ANY DERIVATIVE WORK.
 *
 * Carnegie  Mellon  encourages  users  of  this  software  to return any
 * improvements or extensions that  they  make,  and  to  grant  Carnegie
 * Mellon the rights to redistribute these changes without encumbrance.
 *
 * 	@(#) cfs/cfs_subr.c,v 1.1.1.1 1998/08/29 21:26:45 rvb Exp $
 */

/*
 * Mach Operating System
 * Copyright (c) 1989 Carnegie-Mellon University
 * All rights reserved.  The CMU software License Agreement specifies
 * the terms and conditions for use and redistribution.
 */

/*
 * This code was written for the Coda file system at Carnegie Mellon
 * University.  Contributers include David Steere, James Kistler, and
 * M. Satyanarayanan.  */

/*
 * HISTORY
 * $Log: coda_subr.c,v $
 * Revision 1.2  1998/09/08 17:12:47  rvb
 * Pass2 complete
 *
 * Revision 1.1.1.1  1998/08/29 21:26:45  rvb
 * Very Preliminary Coda
 *
 * Revision 1.11  1998/08/28 18:12:18  rvb
 * Now it also works on FreeBSD -current.  This code will be
 * committed to the FreeBSD -current and NetBSD -current
 * trees.  It will then be tailored to the particular platform
 * by flushing conditional code.
 *
 * Revision 1.10  1998/08/18 17:05:16  rvb
 * Don't use __RCSID now
 *
 * Revision 1.9  1998/08/18 16:31:41  rvb
 * Sync the code for NetBSD -current; test on 1.3 later
 *
 * Revision 1.8  98/01/31  20:53:12  rvb
 * First version that works on FreeBSD 2.2.5
 *
 * Revision 1.7  98/01/23  11:53:42  rvb
 * Bring RVB_CFS1_1 to HEAD
 *
 * Revision 1.6.2.3  98/01/23  11:21:05  rvb
 * Sync with 2.2.5
 *
 * Revision 1.6.2.2  97/12/16  12:40:06  rvb
 * Sync with 1.3
 *
 * Revision 1.6.2.1  97/12/06  17:41:21  rvb
 * Sync with peters coda.h
 *
 * Revision 1.6  97/12/05  10:39:17  rvb
 * Read CHANGES
 *
 * Revision 1.5.4.8  97/11/26  15:28:58  rvb
 * Cant make downcall pbuf == union cfs_downcalls yet
 *
 * Revision 1.5.4.7  97/11/20  11:46:42  rvb
 * Capture current cfs_venus
 *
 * Revision 1.5.4.6  97/11/18  10:27:16  rvb
 * cfs_nbsd.c is DEAD!!!; integrated into cfs_vf/vnops.c
 * cfs_nb_foo and cfs_foo are joined
 *
 * Revision 1.5.4.5  97/11/13  22:03:00  rvb
 * pass2 cfs_NetBSD.h mt
 *
 * Revision 1.5.4.4  97/11/12  12:09:39  rvb
 * reorg pass1
 *
 * Revision 1.5.4.3  97/11/06  21:02:38  rvb
 * first pass at ^c ^z
 *
 * Revision 1.5.4.2  97/10/29  16:06:27  rvb
 * Kill DYING
 *
 * Revision 1.5.4.1  97/10/28 23:10:16  rvb
 * >64Meg; venus can be killed!
 *
 * Revision 1.5  97/08/05  11:08:17  lily
 * Removed cfsnc_replace, replaced it with a cfs_find, unhash, and
 * rehash.  This fixes a cnode leak and a bug in which the fid is
 * not actually replaced.  (cfs_namecache.c, cfsnc.h, cfs_subr.c)
 *
 * Revision 1.4  96/12/12  22:10:59  bnoble
 * Fixed the "downcall invokes venus operation" deadlock in all known cases.
 * There may be more
 *
 * Revision 1.3  1996/12/05 16:20:15  bnoble
 * Minor debugging aids
 *
 * Revision 1.2  1996/01/02 16:57:01  bnoble
 * Added support for Coda MiniCache and raw inode calls (final commit)
 *
 * Revision 1.1.2.1  1995/12/20 01:57:27  bnoble
 * Added CFS-specific files
 *
 * Revision 3.1.1.1  1995/03/04  19:07:59  bnoble
 * Branch for NetBSD port revisions
 *
 * Revision 3.1  1995/03/04  19:07:58  bnoble
 * Bump to major revision 3 to prepare for NetBSD port
 *
 * Revision 2.8  1995/03/03  17:00:04  dcs
 * Fixed kernel bug involving sleep and upcalls. Basically if you killed
 * a job waiting on venus, the venus upcall queues got trashed. Depending
 * on luck, you could kill the kernel or not.
 * (mods to cfs_subr.c and cfs_mach.d)
 *
 * Revision 2.7  95/03/02  22:45:21  dcs
 * Sun4 compatibility
 *
 * Revision 2.6  95/02/17  16:25:17  dcs
 * These versions represent several changes:
 * 1. Allow venus to restart even if outstanding references exist.
 * 2. Have only one ctlvp per client, as opposed to one per mounted cfs device.d
 * 3. Allow ody_expand to return many members, not just one.
 *
 * Revision 2.5  94/11/09  15:56:26  dcs
 * Had the thread sleeping on the wrong thing!
 *
 * Revision 2.4  94/10/14  09:57:57  dcs
 * Made changes 'cause sun4s have braindead compilers
 *
 * Revision 2.3  94/10/12  16:46:26  dcs
 * Cleaned kernel/venus interface by removing XDR junk, plus
 * so cleanup to allow this code to be more easily ported.
 *
 * Revision 1.2  92/10/27  17:58:22  lily
 * merge kernel/latest and alpha/src/cfs
 *
 * Revision 2.4  92/09/30  14:16:26  mja
 * 	Incorporated Dave Steere's fix for the GNU-Emacs bug.
 * 	Also, included his cfs_flush routine in place of the former cfsnc_flush.
 * 	[91/02/07            jjk]
 *
 * 	Added contributors blurb.
 * 	[90/12/13            jjk]
 *
 * 	Hack to allow users to keep coda venus calls uninterruptible. THis
 * 	basically prevents the Gnu-emacs bug from appearing, in which a call
 * 	was being interrupted, and return EINTR, but gnu didn't check for the
 * 	error and figured the file was buggered.
 * 	[90/12/09            dcs]
 *
 * Revision 2.3  90/08/10  10:23:20  mrt
 * 	Removed include of vm/vm_page.h as it no longer exists.
 * 	[90/08/10            mrt]
 *
 * Revision 2.2  90/07/05  11:26:35  mrt
 * 	Initialize name cache on first call to vcopen.
 * 	[90/05/23            dcs]
 *
 * 	Created for the Coda File System.
 * 	[90/05/23            dcs]
 *
 * Revision 1.5  90/05/31  17:01:35  dcs
 * Prepare for merge with facilities kernel.
 *
 * Revision 1.2  90/03/19  15:56:25  dcs
 * Initialize name cache on first call to vcopen.
 *
 * Revision 1.1  90/03/15  10:43:26  jjk
 * Initial revision
 *
 */

/* NOTES: rvb
 * 1.	Added cfs_unmounting to mark all cnodes as being UNMOUNTING.  This has to
 *	 be done before dounmount is called.  Because some of the routines that
 *	 dounmount calls before cfs_unmounted might try to force flushes to venus.
 *	 The vnode pager does this.
 * 2.	cfs_unmounting marks all cnodes scanning cfs_cache.
 * 3.	cfs_checkunmounting (under DEBUG) checks all cnodes by chasing the vnodes
 *	 under the /coda mount point.
 * 4.	cfs_cacheprint (under DEBUG) prints names with vnode/cnode address
 */

#include <vcfs.h>

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/select.h>
#include <sys/mount.h>

#include <cfs/coda.h>
#include <cfs/cnode.h>
#include <cfs/cfs_subr.h>
#include <cfs/cfsnc.h>

int cfs_active = 0;
int cfs_reuse = 0;
int cfs_new = 0;

struct cnode *cfs_freelist = NULL;
struct cnode *cfs_cache[CFS_CACHESIZE];

#define cfshash(fid) \
    (((fid)->Volume + (fid)->Vnode) & (CFS_CACHESIZE-1))

#define	CNODE_NEXT(cp)	((cp)->c_next)

#define ODD(vnode)        ((vnode) & 0x1)

/*
 * Allocate a cnode.
 */
struct cnode *
cfs_alloc(void)
{
    struct cnode *cp;

    if (cfs_freelist) {
	cp = cfs_freelist;
	cfs_freelist = CNODE_NEXT(cp);
	cfs_reuse++;
    }
    else {
	CFS_ALLOC(cp, struct cnode *, sizeof(struct cnode));
	/* NetBSD vnodes don't have any Pager info in them ('cause there are
	   no external pagers, duh!) */
#define VNODE_VM_INFO_INIT(vp)         /* MT */
	VNODE_VM_INFO_INIT(CTOV(cp));
	cfs_new++;
    }
    bzero(cp, sizeof (struct cnode));

    return(cp);
}

/*
 * Deallocate a cnode.
 */
void
cfs_free(cp)
     register struct cnode *cp;
{

    CNODE_NEXT(cp) = cfs_freelist;
    cfs_freelist = cp;
}

/*
 * Put a cnode in the hash table
 */
void
cfs_save(cp)
     struct cnode *cp;
{
	CNODE_NEXT(cp) = cfs_cache[cfshash(&cp->c_fid)];
	cfs_cache[cfshash(&cp->c_fid)] = cp;
}

/*
 * Remove a cnode from the hash table
 */
void
cfs_unsave(cp)
     struct cnode *cp;
{
    struct cnode *ptr;
    struct cnode *ptrprev = NULL;

    ptr = cfs_cache[cfshash(&cp->c_fid)];
    while (ptr != NULL) {
	if (ptr == cp) {
	    if (ptrprev == NULL) {
		cfs_cache[cfshash(&cp->c_fid)]
		    = CNODE_NEXT(ptr);
	    } else {
		CNODE_NEXT(ptrprev) = CNODE_NEXT(ptr);
	    }
	    CNODE_NEXT(cp) = (struct cnode *)NULL;

	    return;
	}
	ptrprev = ptr;
	ptr = CNODE_NEXT(ptr);
    }
}

/*
 * Lookup a cnode by fid. If the cnode is dying, it is bogus so skip it.
 * NOTE: this allows multiple cnodes with same fid -- dcs 1/25/95
 */
struct cnode *
cfs_find(fid)
     ViceFid *fid;
{
    struct cnode *cp;

    cp = cfs_cache[cfshash(fid)];
    while (cp) {
	if ((cp->c_fid.Vnode == fid->Vnode) &&
	    (cp->c_fid.Volume == fid->Volume) &&
	    (cp->c_fid.Unique == fid->Unique) &&
	    (!IS_UNMOUNTING(cp)))
	    {
		cfs_active++;
		return(cp);
	    }
	cp = CNODE_NEXT(cp);
    }
    return(NULL);
}

/*
 * cfs_kill is called as a side effect to vcopen. To prevent any
 * cnodes left around from an earlier run of a venus or warden from
 * causing problems with the new instance, mark any outstanding cnodes
 * as dying. Future operations on these cnodes should fail (excepting
 * cfs_inactive of course!). Since multiple venii/wardens can be
 * running, only kill the cnodes for a particular entry in the
 * cfs_mnttbl. -- DCS 12/1/94 */

int
cfs_kill(whoIam, dcstat)
	struct mount *whoIam;
	enum dc_status dcstat;
{
	int hash, count = 0;
	struct cnode *cp;

	/*
	 * Algorithm is as follows:
	 *     Second, flush whatever vnodes we can from the name cache.
	 *
	 *     Finally, step through whatever is left and mark them dying.
	 *        This prevents any operation at all.

	 */

	/* This is slightly overkill, but should work. Eventually it'd be
	 * nice to only flush those entries from the namecache that
	 * reference a vnode in this vfs.  */
	cfsnc_flush(dcstat);

	for (hash = 0; hash < CFS_CACHESIZE; hash++) {
		for (cp = cfs_cache[hash]; cp != NULL; cp = CNODE_NEXT(cp)) {
			if (CTOV(cp)->v_mount == whoIam) {
#ifdef	DEBUG
				printf("cfs_kill: vp %p, cp %p\n", CTOV(cp), cp);
#endif
				count++;
				CFSDEBUG(CFS_FLUSH,
					 myprintf(("Live cnode fid %lx.%lx.%lx flags %d count %d\n",
						   (cp->c_fid).Volume,
						   (cp->c_fid).Vnode,
						   (cp->c_fid).Unique,
						   cp->c_flags,
						   CTOV(cp)->v_usecount)); );
			}
		}
	}
	return count;
}

/*
 * There are two reasons why a cnode may be in use, it may be in the
 * name cache or it may be executing.
 */
void
cfs_flush(dcstat)
	enum dc_status dcstat;
{
    int hash;
    struct cnode *cp;

    cfs_clstat.ncalls++;
    cfs_clstat.reqs[CFS_FLUSH]++;

    cfsnc_flush(dcstat);	    /* flush files from the name cache */

    for (hash = 0; hash < CFS_CACHESIZE; hash++) {
	for (cp = cfs_cache[hash]; cp != NULL; cp = CNODE_NEXT(cp)) {
	    if (!ODD(cp->c_fid.Vnode)) /* only files can be executed */
		cfs_vmflush(cp);
	}
    }
}

/*
 * As a debugging measure, print out any cnodes that lived through a
 * name cache flush.
 */
void
cfs_testflush(void)
{
    int hash;
    struct cnode *cp;

    for (hash = 0; hash < CFS_CACHESIZE; hash++) {
	for (cp = cfs_cache[hash];
	     cp != NULL;
	     cp = CNODE_NEXT(cp)) {
	    myprintf(("Live cnode fid %lx.%lx.%lx count %d\n",
		      (cp->c_fid).Volume,(cp->c_fid).Vnode,
		      (cp->c_fid).Unique, CTOV(cp)->v_usecount));
	}
    }
}

/*
 *     First, step through all cnodes and mark them unmounting.
 *         NetBSD kernels may try to fsync them now that venus
 *         is dead, which would be a bad thing.
 *
 */
void
cfs_unmounting(whoIam)
	struct mount *whoIam;
{
	int hash;
	struct cnode *cp;

	for (hash = 0; hash < CFS_CACHESIZE; hash++) {
		for (cp = cfs_cache[hash]; cp != NULL; cp = CNODE_NEXT(cp)) {
			if (CTOV(cp)->v_mount == whoIam) {
				if (cp->c_flags & (C_LOCKED|C_WANTED)) {
					printf("cfs_unmounting: Unlocking %p\n", cp);
					cp->c_flags &= ~(C_LOCKED|C_WANTED);
					wakeup((caddr_t) cp);
				}
				cp->c_flags |= C_UNMOUNTING;
			}
		}
	}
}

#ifdef	DEBUG
cfs_checkunmounting(mp)
	struct mount *mp;
{
	register struct vnode *vp, *nvp;
	struct cnode *cp;
	int count = 0, bad = 0;
loop:
	for (vp = mp->mnt_vnodelist.lh_first; vp; vp = nvp) {
		if (vp->v_mount != mp)
			goto loop;
		nvp = vp->v_mntvnodes.le_next;
		cp = VTOC(vp);
		count++;
		if (!(cp->c_flags & C_UNMOUNTING)) {
			bad++;
			printf("vp %p, cp %p missed\n", vp, cp);
			cp->c_flags |= C_UNMOUNTING;
		}
	}
}

int
cfs_cacheprint(whoIam)
	struct mount *whoIam;
{
	int hash;
	struct cnode *cp;
	int count = 0;

	printf("cfs_cacheprint: cfs_ctlvp %p, cp %p", cfs_ctlvp, VTOC(cfs_ctlvp));
	cfsnc_name(cfs_ctlvp);
	printf("\n");

	for (hash = 0; hash < CFS_CACHESIZE; hash++) {
		for (cp = cfs_cache[hash]; cp != NULL; cp = CNODE_NEXT(cp)) {
			if (CTOV(cp)->v_mount == whoIam) {
				printf("cfs_cacheprint: vp %p, cp %p", CTOV(cp), cp);
				cfsnc_name(cp);
				printf("\n");
				count++;
			}
		}
	}
	printf("cfs_cacheprint: count %d\n", count);
}
#endif

/*
 * There are 6 cases where invalidations occur. The semantics of each
 * is listed here.
 *
 * CFS_FLUSH     -- flush all entries from the name cache and the cnode cache.
 * CFS_PURGEUSER -- flush all entries from the name cache for a specific user
 *                  This call is a result of token expiration.
 *
 * The next two are the result of callbacks on a file or directory.
 * CFS_ZAPDIR    -- flush the attributes for the dir from its cnode.
 *                  Zap all children of this directory from the namecache.
 * CFS_ZAPFILE   -- flush the attributes for a file.
 *
 * The fifth is a result of Venus detecting an inconsistent file.
 * CFS_PURGEFID  -- flush the attribute for the file
 *                  If it is a dir (odd vnode), purge its
 *                  children from the namecache
 *                  remove the file from the namecache.
 *
 * The sixth allows Venus to replace local fids with global ones
 * during reintegration.
 *
 * CFS_REPLACE -- replace one ViceFid with another throughout the name cache
 */

int handleDownCall(opcode, out)
     int opcode; union outputArgs *out;
{
    int error;

    /* Handle invalidate requests. */
    switch (opcode) {
      case CFS_FLUSH : {

	  cfs_flush(IS_DOWNCALL);

	  CFSDEBUG(CFS_FLUSH,cfs_testflush();)    /* print remaining cnodes */
	      return(0);
      }

      case CFS_PURGEUSER : {
	  cfs_clstat.ncalls++;
	  cfs_clstat.reqs[CFS_PURGEUSER]++;

	  /* XXX - need to prevent fsync's */
	  cfsnc_purge_user(out->cfs_purgeuser.cred.cr_uid, IS_DOWNCALL);
	  return(0);
      }

      case CFS_ZAPFILE : {
	  struct cnode *cp;

	  error = 0;
	  cfs_clstat.ncalls++;
	  cfs_clstat.reqs[CFS_ZAPFILE]++;

	  cp = cfs_find(&out->cfs_zapfile.CodaFid);
	  if (cp != NULL) {
	      vref(CTOV(cp));

	      cp->c_flags &= ~C_VATTR;
	      if (CTOV(cp)->v_flag & VTEXT)
		  error = cfs_vmflush(cp);
	      CFSDEBUG(CFS_ZAPFILE, myprintf(("zapfile: fid = (%lx.%lx.%lx),
                                              refcnt = %d, error = %d\n",
					      cp->c_fid.Volume,
					      cp->c_fid.Vnode,
					      cp->c_fid.Unique,
					      CTOV(cp)->v_usecount - 1, error)););
	      if (CTOV(cp)->v_usecount == 1) {
		  cp->c_flags |= C_PURGING;
	      }
	      vrele(CTOV(cp));
	  }

	  return(error);
      }

      case CFS_ZAPDIR : {
	  struct cnode *cp;

	  cfs_clstat.ncalls++;
	  cfs_clstat.reqs[CFS_ZAPDIR]++;

	  cp = cfs_find(&out->cfs_zapdir.CodaFid);
	  if (cp != NULL) {
	      vref(CTOV(cp));

	      cp->c_flags &= ~C_VATTR;
	      cfsnc_zapParentfid(&out->cfs_zapdir.CodaFid, IS_DOWNCALL);

	      CFSDEBUG(CFS_ZAPDIR, myprintf(("zapdir: fid = (%lx.%lx.%lx),
                                          refcnt = %d\n",cp->c_fid.Volume,
					     cp->c_fid.Vnode,
					     cp->c_fid.Unique,
					     CTOV(cp)->v_usecount - 1)););
	      if (CTOV(cp)->v_usecount == 1) {
		  cp->c_flags |= C_PURGING;
	      }
	      vrele(CTOV(cp));
	  }

	  return(0);
      }

      case CFS_ZAPVNODE : {
	  cfs_clstat.ncalls++;
	  cfs_clstat.reqs[CFS_ZAPVNODE]++;

	  myprintf(("CFS_ZAPVNODE: Called, but uniplemented\n"));
	  /*
	   * Not that below we must really translate the returned coda_cred to
	   * a netbsd cred.  This is a bit muddled at present and the cfsnc_zapnode
	   * is further unimplemented, so punt!
	   * I suppose we could use just the uid.
	   */
	  /* cfsnc_zapvnode(&out->cfs_zapvnode.VFid, &out->cfs_zapvnode.cred,
			 IS_DOWNCALL); */
	  return(0);
      }

      case CFS_PURGEFID : {
	  struct cnode *cp;

	  error = 0;
	  cfs_clstat.ncalls++;
	  cfs_clstat.reqs[CFS_PURGEFID]++;

	  cp = cfs_find(&out->cfs_purgefid.CodaFid);
	  if (cp != NULL) {
	      vref(CTOV(cp));
	      if (ODD(out->cfs_purgefid.CodaFid.Vnode)) { /* Vnode is a directory */
		  cfsnc_zapParentfid(&out->cfs_purgefid.CodaFid,
				     IS_DOWNCALL);
	      }
	      cp->c_flags &= ~C_VATTR;
	      cfsnc_zapfid(&out->cfs_purgefid.CodaFid, IS_DOWNCALL);
	      if (!(ODD(out->cfs_purgefid.CodaFid.Vnode))
		  && (CTOV(cp)->v_flag & VTEXT)) {

		  error = cfs_vmflush(cp);
	      }
	      CFSDEBUG(CFS_PURGEFID, myprintf(("purgefid: fid = (%lx.%lx.%lx), refcnt = %d, error = %d\n",
                                            cp->c_fid.Volume, cp->c_fid.Vnode,
                                            cp->c_fid.Unique,
					    CTOV(cp)->v_usecount - 1, error)););
	      if (CTOV(cp)->v_usecount == 1) {
		  cp->c_flags |= C_PURGING;
	      }
	      vrele(CTOV(cp));
	  }
	  return(error);
      }

      case CFS_REPLACE : {
	  struct cnode *cp = NULL;

	  cfs_clstat.ncalls++;
	  cfs_clstat.reqs[CFS_REPLACE]++;

	  cp = cfs_find(&out->cfs_replace.OldFid);
	  if (cp != NULL) {
	      /* remove the cnode from the hash table, replace the fid, and reinsert */
	      vref(CTOV(cp));
	      cfs_unsave(cp);
	      cp->c_fid = out->cfs_replace.NewFid;
	      cfs_save(cp);

	      CFSDEBUG(CFS_REPLACE, myprintf(("replace: oldfid = (%lx.%lx.%lx), newfid = (%lx.%lx.%lx), cp = %p\n",
					   out->cfs_replace.OldFid.Volume,
					   out->cfs_replace.OldFid.Vnode,
					   out->cfs_replace.OldFid.Unique,
					   cp->c_fid.Volume, cp->c_fid.Vnode,
					   cp->c_fid.Unique, cp));)
	      vrele(CTOV(cp));
	  }
	  return (0);
      }
      default:
      	myprintf(("handleDownCall: unknown opcode %d\n", opcode));
	return (EINVAL);
    }
}

/* cfs_grab_vnode: lives in either cfs_mach.c or cfs_nbsd.c */

int
cfs_vmflush(cp)
     struct cnode *cp;
{
    return 0;
}


/*
 * kernel-internal debugging switches
 */

void cfs_debugon(void)
{
    cfsdebug = -1;
    cfsnc_debug = -1;
    cfs_vnop_print_entry = 1;
    cfs_psdev_print_entry = 1;
    cfs_vfsop_print_entry = 1;
}

void cfs_debugoff(void)
{
    cfsdebug = 0;
    cfsnc_debug = 0;
    cfs_vnop_print_entry = 0;
    cfs_psdev_print_entry = 0;
    cfs_vfsop_print_entry = 0;
}

/*
 * Utilities used by both client and server
 * Standard levels:
 * 0) no debugging
 * 1) hard failures
 * 2) soft failures
 * 3) current test software
 * 4) main procedure entry points
 * 5) main procedure exit points
 * 6) utility procedure entry points
 * 7) utility procedure exit points
 * 8) obscure procedure entry points
 * 9) obscure procedure exit points
 * 10) random stuff
 * 11) all <= 1
 * 12) all <= 2
 * 13) all <= 3
 * ...
 */