- Replace v_flag with v_iflag and v_vflag

 - v_vflag is protected by the vnode lock and is used when synchronization
   with VOP calls is needed.
 - v_iflag is protected by interlock and is used for dealing with vnode
   management issues.  These flags include X/O LOCK, FREE, DOOMED, etc.
 - All accesses to v_iflag and v_vflag have either been locked or marked with
   mp_fixme's.
 - Many ASSERT_VOP_LOCKED calls have been added where the locking was not
   clear.
 - Many functions in vfs_subr.c were restructured to provide for stronger
   locking.

Idea stolen from:	BSD/OS

88 files changed, 620 insertions, 414 deletions

diff --git a/sys/alpha/osf1/imgact_osf1.c b/sys/alpha/osf1/imgact_osf1.c
index 4eee3a7..3a640b4 100644
--- a/sys/alpha/osf1/imgact_osf1.c
+++ b/sys/alpha/osf1/imgact_osf1.c
@@ -188,15 +188,16 @@ exec_osf1_imgact(struct image_params *imgp)
 	imgp->interpreted = 0;
 	imgp->proc->p_sysent = &osf1_sysvec;
 
+	mp_fixme("Unlocked writecount and v_vflag access.");
 	if ((eap->tsize != 0 || eap->dsize != 0) &&
 	    imgp->vp->v_writecount != 0) {
 #ifdef DIAGNOSTIC
-		if (imgp->vp->v_flag & VTEXT)
-			panic("exec: a VTEXT vnode has writecount != 0\n");
+		if (imgp->vp->v_vflag & VV_TEXT)
+			panic("exec: a VV_TEXT vnode has writecount != 0\n");
 #endif
 		return ETXTBSY;
 	}
-	imgp->vp->v_flag |= VTEXT;
+	imgp->vp->v_vflag |= VV_TEXT;
 
 	/* set up text segment */
 	if ((error = vm_mmap(&vmspace->vm_map, &taddr, tsize,
diff --git a/sys/coda/coda_namecache.c b/sys/coda/coda_namecache.c
index 97e5b2e..f2d4940 100644
--- a/sys/coda/coda_namecache.c
+++ b/sys/coda/coda_namecache.c
@@ -613,7 +613,8 @@ coda_nc_flush(dcstat)
 			}
 			vrele(CTOV(cncp->dcp)); 
 
-			if (CTOV(cncp->cp)->v_flag & VTEXT) {
+			ASSERT_VOP_LOCKED(CTOV(cnp->cp), "coda_nc_flush");
+			if (CTOV(cncp->cp)->v_vflag & VV_TEXT) {
 			    if (coda_vmflush(cncp->cp))
 				CODADEBUG(CODA_FLUSH, 
 					 myprintf(("coda_nc_flush: (%lx.%lx.%lx) busy\n", cncp->cp->c_fid.Volume, cncp->cp->c_fid.Vnode, cncp->cp->c_fid.Unique)); )
diff --git a/sys/coda/coda_subr.c b/sys/coda/coda_subr.c
index 571f9ca..8afe57d 100644
--- a/sys/coda/coda_subr.c
+++ b/sys/coda/coda_subr.c
@@ -413,7 +413,8 @@ int handleDownCall(opcode, out)
 	      vref(CTOV(cp));
 	      
 	      cp->c_flags &= ~C_VATTR;
-	      if (CTOV(cp)->v_flag & VTEXT)
+	      ASSERT_VOP_LOCKED(CTOV(cp), "coda HandleDownCall");
+	      if (CTOV(cp)->v_vflag & VV_TEXT)
 		  error = coda_vmflush(cp);
 	      CODADEBUG(CODA_ZAPFILE, myprintf((
 "zapfile: fid = (%lx.%lx.%lx), refcnt = %d, error = %d\n",
@@ -470,8 +471,9 @@ int handleDownCall(opcode, out)
 	      }
 	      cp->c_flags &= ~C_VATTR;
 	      coda_nc_zapfid(&out->coda_purgefid.CodaFid, IS_DOWNCALL);
+	      ASSERT_VOP_LOCKED(CTOV(cp), "coda HandleDownCall");
 	      if (!(ODD(out->coda_purgefid.CodaFid.Vnode)) 
-		  && (CTOV(cp)->v_flag & VTEXT)) {
+		  && (CTOV(cp)->v_vflag & VV_TEXT)) {
 		  
 		  error = coda_vmflush(cp);
 	      }
diff --git a/sys/coda/coda_vfsops.c b/sys/coda/coda_vfsops.c
index 33597d6..5040e68 100644
--- a/sys/coda/coda_vfsops.c
+++ b/sys/coda/coda_vfsops.c
@@ -192,7 +192,7 @@ coda_mount(vfsp, path, data, ndp, td)
     rootfid.Unique = 0;
     cp = make_coda_node(&rootfid, vfsp, VDIR);
     rootvp = CTOV(cp);
-    rootvp->v_flag |= VROOT;
+    rootvp->v_vflag |= VV_ROOT;
 	
     ctlfid.Volume = CTL_VOL;
     ctlfid.Vnode = CTL_VNO;
@@ -257,7 +257,8 @@ coda_unmount(vfsp, mntflags, td)
 	vrele(mi->mi_rootvp);
 
 	active = coda_kill(vfsp, NOT_DOWNCALL);
-	mi->mi_rootvp->v_flag &= ~VROOT;
+	ASSERT_VOP_LOCKED(mi->mi_rootvp, "coda_unmount");
+	mi->mi_rootvp->v_vflag &= ~VV_ROOT;
 	error = vflush(mi->mi_vfsp, 0, FORCECLOSE);
 	printf("coda_unmount: active = %d, vflush active %d\n", active, error);
 	error = 0;
diff --git a/sys/compat/linux/linux_getcwd.c b/sys/compat/linux/linux_getcwd.c
index 44079b9..2773562 100644
--- a/sys/compat/linux/linux_getcwd.c
+++ b/sys/compat/linux/linux_getcwd.c
@@ -351,7 +351,7 @@ linux_getcwd_common (lvp, rvp, bpp, bufp, limit, flags, td)
 		/*
 		 * step up if we're a covered vnode..
 		 */
-		while (lvp->v_flag & VROOT) {
+		while (lvp->v_vflag & VV_ROOT) {
 			struct vnode *tvp;
 
 			if (lvp == rvp)
diff --git a/sys/compat/linux/linux_misc.c b/sys/compat/linux/linux_misc.c
index 7eebf69..d6259bc 100644
--- a/sys/compat/linux/linux_misc.c
+++ b/sys/compat/linux/linux_misc.c
@@ -381,8 +381,9 @@ linux_uselib(struct thread *td, struct linux_uselib_args *args)
 		goto cleanup;
 	}
 
+	mp_fixme("Unlocked vflags access.");
 	/* prevent more writers */
-	vp->v_flag |= VTEXT;
+	vp->v_vflag |= VV_TEXT;
 
 	/*
 	 * Check if file_offset page aligned. Currently we cannot handle
diff --git a/sys/compat/pecoff/imgact_pecoff.c b/sys/compat/pecoff/imgact_pecoff.c
index 2d4691d..175b021 100644
--- a/sys/compat/pecoff/imgact_pecoff.c
+++ b/sys/compat/pecoff/imgact_pecoff.c
@@ -533,7 +533,8 @@ exec_pecoff_coff_prep_zmagic(struct image_params * imgp,
 	imgp->auxarg_size = sizeof(struct pecoff_args);
 	imgp->interpreted = 0;
 
-	imgp->vp->v_flag |= VTEXT;
+	mp_fixme("Unlocked vflag access.");
+	imgp->vp->v_vflag |= VV_TEXT;
 	if (sh != NULL)
 		free(sh, M_TEMP);
 	return 0;
diff --git a/sys/compat/svr4/imgact_svr4.c b/sys/compat/svr4/imgact_svr4.c
index ad72929..c8b0e1f8 100644
--- a/sys/compat/svr4/imgact_svr4.c
+++ b/sys/compat/svr4/imgact_svr4.c
@@ -216,7 +216,8 @@ exec_svr4_imgact(imgp)
 
 	}
 	/* Indicate that this file should not be modified */
-	imgp->vp->v_flag |= VTEXT;
+	mp_fixme("Unlocked vflag access.");
+	imgp->vp->v_vflag |= VV_TEXT;
     }
     /* Fill in process VM information */
     vmspace->vm_tsize = round_page(a_out->a_text) >> PAGE_SHIFT;
diff --git a/sys/fs/cd9660/cd9660_vfsops.c b/sys/fs/cd9660/cd9660_vfsops.c
index 53715e7..980612e 100644
--- a/sys/fs/cd9660/cd9660_vfsops.c
+++ b/sys/fs/cd9660/cd9660_vfsops.c
@@ -869,7 +869,7 @@ cd9660_vget_internal(mp, ino, flags, vpp, relocated, isodir)
 	}
 	
 	if (ip->iso_extent == imp->root_extent)
-		vp->v_flag |= VROOT;
+		vp->v_vflag |= VV_ROOT;
 
 	/*
 	 * XXX need generation number?
diff --git a/sys/fs/coda/coda_namecache.c b/sys/fs/coda/coda_namecache.c
index 97e5b2e..f2d4940 100644
--- a/sys/fs/coda/coda_namecache.c
+++ b/sys/fs/coda/coda_namecache.c
@@ -613,7 +613,8 @@ coda_nc_flush(dcstat)
 			}
 			vrele(CTOV(cncp->dcp)); 
 
-			if (CTOV(cncp->cp)->v_flag & VTEXT) {
+			ASSERT_VOP_LOCKED(CTOV(cnp->cp), "coda_nc_flush");
+			if (CTOV(cncp->cp)->v_vflag & VV_TEXT) {
 			    if (coda_vmflush(cncp->cp))
 				CODADEBUG(CODA_FLUSH, 
 					 myprintf(("coda_nc_flush: (%lx.%lx.%lx) busy\n", cncp->cp->c_fid.Volume, cncp->cp->c_fid.Vnode, cncp->cp->c_fid.Unique)); )
diff --git a/sys/fs/coda/coda_subr.c b/sys/fs/coda/coda_subr.c
index 571f9ca..8afe57d 100644
--- a/sys/fs/coda/coda_subr.c
+++ b/sys/fs/coda/coda_subr.c
@@ -413,7 +413,8 @@ int handleDownCall(opcode, out)
 	      vref(CTOV(cp));
 	      
 	      cp->c_flags &= ~C_VATTR;
-	      if (CTOV(cp)->v_flag & VTEXT)
+	      ASSERT_VOP_LOCKED(CTOV(cp), "coda HandleDownCall");
+	      if (CTOV(cp)->v_vflag & VV_TEXT)
 		  error = coda_vmflush(cp);
 	      CODADEBUG(CODA_ZAPFILE, myprintf((
 "zapfile: fid = (%lx.%lx.%lx), refcnt = %d, error = %d\n",
@@ -470,8 +471,9 @@ int handleDownCall(opcode, out)
 	      }
 	      cp->c_flags &= ~C_VATTR;
 	      coda_nc_zapfid(&out->coda_purgefid.CodaFid, IS_DOWNCALL);
+	      ASSERT_VOP_LOCKED(CTOV(cp), "coda HandleDownCall");
 	      if (!(ODD(out->coda_purgefid.CodaFid.Vnode)) 
-		  && (CTOV(cp)->v_flag & VTEXT)) {
+		  && (CTOV(cp)->v_vflag & VV_TEXT)) {
 		  
 		  error = coda_vmflush(cp);
 	      }
diff --git a/sys/fs/coda/coda_vfsops.c b/sys/fs/coda/coda_vfsops.c
index 33597d6..5040e68 100644
--- a/sys/fs/coda/coda_vfsops.c
+++ b/sys/fs/coda/coda_vfsops.c
@@ -192,7 +192,7 @@ coda_mount(vfsp, path, data, ndp, td)
     rootfid.Unique = 0;
     cp = make_coda_node(&rootfid, vfsp, VDIR);
     rootvp = CTOV(cp);
-    rootvp->v_flag |= VROOT;
+    rootvp->v_vflag |= VV_ROOT;
 	
     ctlfid.Volume = CTL_VOL;
     ctlfid.Vnode = CTL_VNO;
@@ -257,7 +257,8 @@ coda_unmount(vfsp, mntflags, td)
 	vrele(mi->mi_rootvp);
 
 	active = coda_kill(vfsp, NOT_DOWNCALL);
-	mi->mi_rootvp->v_flag &= ~VROOT;
+	ASSERT_VOP_LOCKED(mi->mi_rootvp, "coda_unmount");
+	mi->mi_rootvp->v_vflag &= ~VV_ROOT;
 	error = vflush(mi->mi_vfsp, 0, FORCECLOSE);
 	printf("coda_unmount: active = %d, vflush active %d\n", active, error);
 	error = 0;
diff --git a/sys/fs/deadfs/dead_vnops.c b/sys/fs/deadfs/dead_vnops.c
index 6ff5038..6734ebe 100644
--- a/sys/fs/deadfs/dead_vnops.c
+++ b/sys/fs/deadfs/dead_vnops.c
@@ -145,7 +145,7 @@ dead_read(ap)
 	/*
 	 * Return EOF for tty devices, EIO for others
 	 */
-	if ((ap->a_vp->v_flag & VISTTY) == 0)
+	if ((ap->a_vp->v_vflag & VV_ISTTY) == 0)
 		return (EIO);
 	return (0);
 }
@@ -262,11 +262,13 @@ chkvnlock(vp)
 {
 	int locked = 0;
 
-	while (vp->v_flag & VXLOCK) {
-		vp->v_flag |= VXWANT;
-		(void) tsleep((caddr_t)vp, PINOD, "ckvnlk", 0);
+	VI_LOCK(vp);
+	while (vp->v_iflag & VI_XLOCK) {
+		vp->v_iflag |= VI_XWANT;
+		(void) msleep((caddr_t)vp, VI_MTX(vp), PINOD, "ckvnlk", 0);
 		locked = 1;
 	}
+	VI_UNLOCK(vp);
 	return (locked);
 }
 
diff --git a/sys/fs/devfs/devfs_vfsops.c b/sys/fs/devfs/devfs_vfsops.c
index 00ad137..319a0b7 100644
--- a/sys/fs/devfs/devfs_vfsops.c
+++ b/sys/fs/devfs/devfs_vfsops.c
@@ -157,7 +157,7 @@ devfs_root(mp, vpp)
 	error = devfs_allocv(dmp->dm_rootdir, mp, &vp, td);
 	if (error)
 		return (error);
-	vp->v_flag |= VROOT;
+	vp->v_vflag |= VV_ROOT;
 	*vpp = vp;
 	return (0);
 }
diff --git a/sys/fs/devfs/devfs_vnops.c b/sys/fs/devfs/devfs_vnops.c
index 9ac3745..62a7b95 100644
--- a/sys/fs/devfs/devfs_vnops.c
+++ b/sys/fs/devfs/devfs_vnops.c
@@ -313,7 +313,7 @@ devfs_lookupx(ap)
 	if (dvp->v_type != VDIR)
 		return (ENOTDIR);
 
-	if ((flags & ISDOTDOT) && (dvp->v_flag & VROOT))
+	if ((flags & ISDOTDOT) && (dvp->v_vflag & VV_ROOT))
 		return (EIO);
 
 	error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, td);
diff --git a/sys/fs/fdescfs/fdesc_vfsops.c b/sys/fs/fdescfs/fdesc_vfsops.c
index d5dc572..a4741bc 100644
--- a/sys/fs/fdescfs/fdesc_vfsops.c
+++ b/sys/fs/fdescfs/fdesc_vfsops.c
@@ -91,7 +91,7 @@ fdesc_mount(mp, ndp, td)
 	MALLOC(fmp, struct fdescmount *, sizeof(struct fdescmount),
 				M_FDESCMNT, M_WAITOK);	/* XXX */
 	rvp->v_type = VDIR;
-	rvp->v_flag |= VROOT;
+	rvp->v_vflag |= VV_ROOT;
 	fmp->f_root = rvp;
 	/* XXX -- don't mark as local to work around fts() problems */
 	/*mp->mnt_flag |= MNT_LOCAL;*/
diff --git a/sys/fs/hpfs/hpfs_vfsops.c b/sys/fs/hpfs/hpfs_vfsops.c
index f5340d4..f4c808d 100644
--- a/sys/fs/hpfs/hpfs_vfsops.c
+++ b/sys/fs/hpfs/hpfs_vfsops.c
@@ -508,7 +508,7 @@ hpfs_vget(
 	vp->v_data = hp;
 
 	if (ino == (ino_t)hpmp->hpm_su.su_rootfno) 
-		vp->v_flag |= VROOT;
+		vp->v_vflag |= VV_ROOT;
 
 
 	mtx_init(&hp->h_interlock, "hpfsnode interlock", NULL, MTX_DEF);
diff --git a/sys/fs/hpfs/hpfs_vnops.c b/sys/fs/hpfs/hpfs_vnops.c
index 827b297..c9d6379 100644
--- a/sys/fs/hpfs/hpfs_vnops.c
+++ b/sys/fs/hpfs/hpfs_vnops.c
@@ -107,10 +107,13 @@ loop:
 		(void) bwrite(bp);
 		goto loop;
 	}
+	VI_LOCK(vp);
 	while (vp->v_numoutput) {
-		vp->v_flag |= VBWAIT;
-		(void) tsleep((caddr_t)&vp->v_numoutput, PRIBIO + 1, "hpfsn", 0);
+		vp->v_iflag |= VI_BWAIT;
+		msleep((caddr_t)&vp->v_numoutput, VI_MTX(vp), PRIBIO + 1,
+		    "hpfsn", 0);
 	}
+	VI_UNLOCK(vp);
 #ifdef DIAGNOSTIC
 	if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
 		vprint("hpfs_fsync: dirty", vp);
diff --git a/sys/fs/msdosfs/msdosfs_denode.c b/sys/fs/msdosfs/msdosfs_denode.c
index 7a0cf79..02b188f 100644
--- a/sys/fs/msdosfs/msdosfs_denode.c
+++ b/sys/fs/msdosfs/msdosfs_denode.c
@@ -300,7 +300,7 @@ deget(pmp, dirclust, diroffset, depp)
 		 * exists), and then use the time and date from that entry
 		 * as the time and date for the root denode.
 		 */
-		nvp->v_flag |= VROOT; /* should be further down		XXX */
+		nvp->v_vflag |= VV_ROOT; /* should be further down XXX */
 
 		ldep->de_Attributes = ATTR_DIRECTORY;
 		ldep->de_LowerCase = 0;
@@ -442,7 +442,7 @@ detrunc(dep, length, flags, cred, td)
 	 * recognize the root directory at this point in a file or
 	 * directory's life.
 	 */
-	if ((DETOV(dep)->v_flag & VROOT) && !FAT32(pmp)) {
+	if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp)) {
 		printf("detrunc(): can't truncate root directory, clust %ld, offset %ld\n",
 		    dep->de_dirclust, dep->de_diroffset);
 		return (EINVAL);
@@ -575,7 +575,7 @@ deextend(dep, length, cred)
 	/*
 	 * The root of a DOS filesystem cannot be extended.
 	 */
-	if ((DETOV(dep)->v_flag & VROOT) && !FAT32(pmp))
+	if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp))
 		return (EINVAL);
 
 	/*
diff --git a/sys/fs/msdosfs/msdosfs_lookup.c b/sys/fs/msdosfs/msdosfs_lookup.c
index 79b0589..00598c8 100644
--- a/sys/fs/msdosfs/msdosfs_lookup.c
+++ b/sys/fs/msdosfs/msdosfs_lookup.c
@@ -136,7 +136,7 @@ msdosfs_lookup(ap)
 	 * they won't find it.  DOS filesystems don't have them in the root
 	 * directory.  So, we fake it. deget() is in on this scam too.
 	 */
-	if ((vdp->v_flag & VROOT) && cnp->cn_nameptr[0] == '.' &&
+	if ((vdp->v_vflag & VV_ROOT) && cnp->cn_nameptr[0] == '.' &&
 	    (cnp->cn_namelen == 1 ||
 		(cnp->cn_namelen == 2 && cnp->cn_nameptr[1] == '.'))) {
 		isadir = ATTR_DIRECTORY;
diff --git a/sys/fs/msdosfs/msdosfs_vfsops.c b/sys/fs/msdosfs/msdosfs_vfsops.c
index f62b0c7..0ad34a0 100644
--- a/sys/fs/msdosfs/msdosfs_vfsops.c
+++ b/sys/fs/msdosfs/msdosfs_vfsops.c
@@ -632,8 +632,9 @@ msdosfs_unmount(mp, mntflags, td)
 		struct vnode *vp = pmp->pm_devvp;
 
 		printf("msdosfs_umount(): just before calling VOP_CLOSE()\n");
-		printf("flag %08lx, usecount %d, writecount %d, holdcnt %ld\n",
-		    vp->v_flag, vp->v_usecount, vp->v_writecount, vp->v_holdcnt);
+		printf("iflag %08lx, usecount %d, writecount %d, holdcnt %ld\n",
+		    vp->vi_flag, vp->v_usecount, vp->v_writecount,
+		    vp->v_holdcnt);
 		printf("id %lu, mount %p, op %p\n",
 		    vp->v_id, vp->v_mount, vp->v_op);
 		printf("freef %p, freeb %p, mount %p\n",
diff --git a/sys/fs/msdosfs/msdosfs_vnops.c b/sys/fs/msdosfs/msdosfs_vnops.c
index 0a5cc48..210e9a8 100644
--- a/sys/fs/msdosfs/msdosfs_vnops.c
+++ b/sys/fs/msdosfs/msdosfs_vnops.c
@@ -815,6 +815,7 @@ msdosfs_fsync(ap)
 	 */
 loop:
 	s = splbio();
+	VI_LOCK(vp);
 	for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
 		nbp = TAILQ_NEXT(bp, b_vnbufs);
 		if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT))
@@ -823,13 +824,17 @@ loop:
 			panic("msdosfs_fsync: not dirty");
 		bremfree(bp);
 		splx(s);
+		VI_UNLOCK(vp);
+		/* XXX Could do bawrite */
 		(void) bwrite(bp);
 		goto loop;
 	}
 	while (vp->v_numoutput) {
-		vp->v_flag |= VBWAIT;
-		(void) tsleep((caddr_t)&vp->v_numoutput, PRIBIO + 1, "msdosfsn", 0);
+		vp->v_vflag |= VI_BWAIT;
+		(void) msleep((caddr_t)&vp->v_numoutput, VI_MTX(vp),
+		    PRIBIO + 1, "msdosfsn", 0);
 	}
+	VI_UNLOCK(vp);
 #ifdef DIAGNOSTIC
 	if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
 		vprint("msdosfs_fsync: dirty", vp);
diff --git a/sys/fs/ntfs/ntfs_vfsops.c b/sys/fs/ntfs/ntfs_vfsops.c
index 82e1158..99b18b4 100644
--- a/sys/fs/ntfs/ntfs_vfsops.c
+++ b/sys/fs/ntfs/ntfs_vfsops.c
@@ -369,7 +369,7 @@ ntfs_mountfs(devvp, mp, argsp, td)
 					 &(ntmp->ntm_sysvn[pi[i]]));
 			if(error)
 				goto out1;
-			ntmp->ntm_sysvn[pi[i]]->v_flag |= VSYSTEM;
+			ntmp->ntm_sysvn[pi[i]]->v_vflag |= VV_SYSTEM;
 			VREF(ntmp->ntm_sysvn[pi[i]]);
 			vput(ntmp->ntm_sysvn[pi[i]]);
 		}
@@ -746,7 +746,7 @@ ntfs_vgetex(
 	vp->v_type = f_type;
 
 	if (ino == NTFS_ROOTINO)
-		vp->v_flag |= VROOT;
+		vp->v_vflag |= VV_ROOT;
 
 	ntfs_ntput(ip);
 
diff --git a/sys/fs/nullfs/null_vfsops.c b/sys/fs/nullfs/null_vfsops.c
index a218bf0..ec41e30 100644
--- a/sys/fs/nullfs/null_vfsops.c
+++ b/sys/fs/nullfs/null_vfsops.c
@@ -187,8 +187,9 @@ nullfs_mount(mp, ndp, td)
 	 * Keep a held reference to the root vnode.
 	 * It is vrele'd in nullfs_unmount.
 	 */
+	mp_fixme("Unlocked vflag access");
 	nullm_rootvp = vp;
-	nullm_rootvp->v_flag |= VROOT;
+	nullm_rootvp->v_vflag |= VV_ROOT;
 	xmp->nullm_rootvp = nullm_rootvp;
 	if (NULLVPTOLOWERVP(nullm_rootvp)->v_mount->mnt_flag & MNT_LOCAL)
 		mp->mnt_flag |= MNT_LOCAL;
diff --git a/sys/fs/nullfs/null_vnops.c b/sys/fs/nullfs/null_vnops.c
index 2b141be..54bd884 100644
--- a/sys/fs/nullfs/null_vnops.c
+++ b/sys/fs/nullfs/null_vnops.c
@@ -794,7 +794,7 @@ null_createvobject(ap)
 	error = VOP_CREATEVOBJECT(lowervp, ap->a_cred, ap->a_td);
 	if (error)
 		return (error);
-	vp->v_flag |= VOBJBUF;
+	vp->v_vflag |= VV_OBJBUF;
 	return (0);
 }
 
@@ -809,7 +809,7 @@ null_destroyvobject(ap)
 {
 	struct vnode *vp = ap->a_vp;
 
-	vp->v_flag &= ~VOBJBUF;
+	vp->v_vflag &= ~VV_OBJBUF;
 	return (0);
 }
 
diff --git a/sys/fs/nwfs/nwfs_io.c b/sys/fs/nwfs/nwfs_io.c
index 9c7d5fa..ffcef2a 100644
--- a/sys/fs/nwfs/nwfs_io.c
+++ b/sys/fs/nwfs/nwfs_io.c
@@ -599,9 +599,13 @@ nwfs_vinvalbuf(vp, flags, cred, td, intrflg)
 /*	struct nwmount *nmp = VTONWFS(vp);*/
 	int error = 0, slpflag, slptimeo;
 
-	if (vp->v_flag & VXLOCK) {
+	VI_LOCK(vp);
+	if (vp->v_iflag & VI_XLOCK) {
+		VI_UNLOCK(vp);
 		return (0);
 	}
+	VI_UNLOCK(vp);
+
 	if (intrflg) {
 		slpflag = PCATCH;
 		slptimeo = 2 * hz;
diff --git a/sys/fs/nwfs/nwfs_node.c b/sys/fs/nwfs/nwfs_node.c
index d8693fa..daf51e1 100644
--- a/sys/fs/nwfs/nwfs_node.c
+++ b/sys/fs/nwfs/nwfs_node.c
@@ -203,8 +203,9 @@ rescan:
 	LIST_INSERT_HEAD(nhpp, np, n_hash);
 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
 	lockmgr(&nwhashlock, LK_RELEASE, NULL, td);
-
-	if (vp->v_type == VDIR && dvp && (dvp->v_flag & VROOT) == 0) {
+	
+	ASSERT_VOP_LOCKED(dvp, "nwfs_allocvp");
+	if (vp->v_type == VDIR && dvp && (dvp->v_vflag & VV_ROOT) == 0) {
 		np->n_flag |= NREFPARENT;
 		vref(dvp);
 	}
diff --git a/sys/fs/nwfs/nwfs_vfsops.c b/sys/fs/nwfs/nwfs_vfsops.c
index dc7d634..76776d9 100644
--- a/sys/fs/nwfs/nwfs_vfsops.c
+++ b/sys/fs/nwfs/nwfs_vfsops.c
@@ -340,7 +340,7 @@ nwfs_root(struct mount *mp, struct vnode **vpp) {
 	error = nwfs_nget(mp, nmp->n_rootent, &fattr, NULL, &vp);
 	if (error)
 		return (error);
-	vp->v_flag |= VROOT;
+	vp->v_vflag |= VV_ROOT;
 	np = VTONW(vp);
 	if (nmp->m.root_path[0] == 0)
 		np->n_flag |= NVOLUME;
diff --git a/sys/fs/nwfs/nwfs_vnops.c b/sys/fs/nwfs/nwfs_vnops.c
index 9d773f8..b62f4f8 100644
--- a/sys/fs/nwfs/nwfs_vnops.c
+++ b/sys/fs/nwfs/nwfs_vnops.c
@@ -289,7 +289,7 @@ nwfs_getattr(ap)
 	int error;
 	u_int32_t oldsize;
 
-	NCPVNDEBUG("%lx:%d: '%s' %d\n", (long)vp, nmp->n_volume, np->n_name, (vp->v_flag & VROOT) != 0);
+	NCPVNDEBUG("%lx:%d: '%s' %d\n", (long)vp, nmp->n_volume, np->n_name, (vp->v_vflag & VV_ROOT) != 0);
 	error = nwfs_attr_cachelookup(vp, va);
 	if (!error) return 0;
 	NCPVNDEBUG("not in cache\n");
@@ -859,7 +859,7 @@ nwfs_lookup(ap)
 	
 	if (dvp->v_type != VDIR)
 		return (ENOTDIR);
-	if ((flags & ISDOTDOT) && (dvp->v_flag & VROOT)) {
+	if ((flags & ISDOTDOT) && (dvp->v_vflag & VV_ROOT)) {
 		printf("nwfs_lookup: invalid '..'\n");
 		return EIO;
 	}
@@ -877,7 +877,7 @@ nwfs_lookup(ap)
 	nmp = VFSTONWFS(mp);
 	dnp = VTONW(dvp);
 /*
-printf("dvp %d:%d:%d\n", (int)mp, (int)dvp->v_flag & VROOT, (int)flags & ISDOTDOT);
+printf("dvp %d:%d:%d\n", (int)mp, (int)dvp->v_vflag & VV_ROOT, (int)flags & ISDOTDOT);
 */
 	error = ncp_pathcheck(cnp->cn_nameptr, cnp->cn_namelen, &nmp->m.nls, 
 	    (nameiop == CREATE || nameiop == RENAME) && (nmp->m.nls.opt & NWHP_NOSTRICT) == 0);
diff --git a/sys/fs/portalfs/portal_vfsops.c b/sys/fs/portalfs/portal_vfsops.c
index c0f4022..025721b 100644
--- a/sys/fs/portalfs/portal_vfsops.c
+++ b/sys/fs/portalfs/portal_vfsops.c
@@ -128,7 +128,7 @@ portal_mount(mp, path, data, ndp, td)
 
 	rvp->v_data = pn;
 	rvp->v_type = VDIR;
-	rvp->v_flag |= VROOT;
+	rvp->v_vflag |= VV_ROOT;
 	VTOPORTAL(rvp)->pt_arg = 0;
 	VTOPORTAL(rvp)->pt_size = 0;
 	VTOPORTAL(rvp)->pt_fileid = PORTAL_ROOTFILEID;
diff --git a/sys/fs/portalfs/portal_vnops.c b/sys/fs/portalfs/portal_vnops.c
index b345c57..2d56232 100644
--- a/sys/fs/portalfs/portal_vnops.c
+++ b/sys/fs/portalfs/portal_vnops.c
@@ -229,7 +229,7 @@ portal_open(ap)
 	/*
 	 * Nothing to do when opening the root node.
 	 */
-	if (vp->v_flag & VROOT)
+	if (vp->v_vflag & VV_ROOT)
 		return (0);
 
 	/*
@@ -462,7 +462,7 @@ portal_getattr(ap)
 	/* vap->va_qbytes = 0; */
 	vap->va_bytes = 0;
 	/* vap->va_qsize = 0; */
-	if (vp->v_flag & VROOT) {
+	if (vp->v_vflag & VV_ROOT) {
 		vap->va_type = VDIR;
 		vap->va_mode = S_IRUSR|S_IWUSR|S_IXUSR|
 				S_IRGRP|S_IWGRP|S_IXGRP|
@@ -493,7 +493,7 @@ portal_setattr(ap)
 	/*
 	 * Can't mess with the root vnode
 	 */
-	if (ap->a_vp->v_flag & VROOT)
+	if (ap->a_vp->v_vflag & VV_ROOT)
 		return (EACCES);
 
 	if (ap->a_vap->va_flags != VNOVAL)
diff --git a/sys/fs/pseudofs/pseudofs_vncache.c b/sys/fs/pseudofs/pseudofs_vncache.c
index 498de38..8d142e9 100644
--- a/sys/fs/pseudofs/pseudofs_vncache.c
+++ b/sys/fs/pseudofs/pseudofs_vncache.c
@@ -143,7 +143,7 @@ pfs_vncache_alloc(struct mount *mp, struct vnode **vpp,
 	(*vpp)->v_data = pvd;
 	switch (pn->pn_type) {
 	case pfstype_root:
-		(*vpp)->v_flag = VROOT;
+		(*vpp)->v_vflag = VV_ROOT;
 #if 0
 		printf("root vnode allocated\n");
 #endif
diff --git a/sys/fs/smbfs/smbfs_io.c b/sys/fs/smbfs/smbfs_io.c
index ebb0934..1baa384 100644
--- a/sys/fs/smbfs/smbfs_io.c
+++ b/sys/fs/smbfs/smbfs_io.c
@@ -671,8 +671,13 @@ smbfs_vinvalbuf(vp, flags, cred, td, intrflg)
 	struct smbnode *np = VTOSMB(vp);
 	int error = 0, slpflag, slptimeo;
 
-	if (vp->v_flag & VXLOCK)
+	VI_LOCK(vp);
+	if (vp->v_iflag & VI_XLOCK) {
+		VI_UNLOCK(vp);
 		return 0;
+	}
+	VI_UNLOCK(vp);
+
 	if (intrflg) {
 		slpflag = PCATCH;
 		slptimeo = 2 * hz;
diff --git a/sys/fs/smbfs/smbfs_node.c b/sys/fs/smbfs/smbfs_node.c
index 8dabd00..4e79f78 100644
--- a/sys/fs/smbfs/smbfs_node.c
+++ b/sys/fs/smbfs/smbfs_node.c
@@ -235,8 +235,9 @@ loop:
 	np->n_ino = fap->fa_ino;
 
 	if (dvp) {
+		ASSERT_VOP_LOCKED(dvp, "smbfs_node_alloc");
 		np->n_parent = dnp;
-		if (/*vp->v_type == VDIR &&*/ (dvp->v_flag & VROOT) == 0) {
+		if (/*vp->v_type == VDIR &&*/ (dvp->v_vflag & VV_ROOT) == 0) {
 			vref(dvp);
 			np->n_flag |= NREFPARENT;
 		}
diff --git a/sys/fs/smbfs/smbfs_vfsops.c b/sys/fs/smbfs/smbfs_vfsops.c
index 5edff3f..2c847c3 100644
--- a/sys/fs/smbfs/smbfs_vfsops.c
+++ b/sys/fs/smbfs/smbfs_vfsops.c
@@ -293,7 +293,8 @@ smbfs_root(struct mount *mp, struct vnode **vpp)
 	error = smbfs_nget(mp, NULL, "TheRooT", 7, &fattr, &vp);
 	if (error)
 		return error;
-	vp->v_flag |= VROOT;
+	ASSERT_VOP_LOCKED(vp, "smbfs_root");
+	vp->v_vflag |= VV_ROOT;
 	np = VTOSMB(vp);
 	smp->sm_root = np;
 	*vpp = vp;
diff --git a/sys/fs/smbfs/smbfs_vnops.c b/sys/fs/smbfs/smbfs_vnops.c
index b471486..219afbf 100644
--- a/sys/fs/smbfs/smbfs_vnops.c
+++ b/sys/fs/smbfs/smbfs_vnops.c
@@ -293,7 +293,7 @@ smbfs_close(ap)
 	int error, dolock;
 
 	VI_LOCK(vp);
-	dolock = (vp->v_flag & VXLOCK) == 0;
+	dolock = (vp->v_iflag & VI_XLOCK) == 0;
 	if (dolock)
 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, td);
 	else
@@ -324,7 +324,7 @@ smbfs_getattr(ap)
 	u_int32_t oldsize;
 	int error;
 
-	SMBVDEBUG("%lx: '%s' %d\n", (long)vp, np->n_name, (vp->v_flag & VROOT) != 0);
+	SMBVDEBUG("%lx: '%s' %d\n", (long)vp, np->n_name, (vp->v_vflag & VV_ROOT) != 0);
 	error = smbfs_attr_cachelookup(vp, va);
 	if (!error)
 		return 0;
@@ -1135,7 +1135,7 @@ smbfs_lookup(ap)
 	cnp->cn_flags &= ~PDIRUNLOCK;
 	if (dvp->v_type != VDIR)
 		return ENOTDIR;
-	if ((flags & ISDOTDOT) && (dvp->v_flag & VROOT)) {
+	if ((flags & ISDOTDOT) && (dvp->v_vflag & VV_ROOT)) {
 		SMBFSERR("invalid '..'\n");
 		return EIO;
 	}
diff --git a/sys/fs/specfs/spec_vnops.c b/sys/fs/specfs/spec_vnops.c
index cbb5e3c..4fb3d5c 100644
--- a/sys/fs/specfs/spec_vnops.c
+++ b/sys/fs/specfs/spec_vnops.c
@@ -195,7 +195,7 @@ spec_open(ap)
 
 	/* XXX: Special casing of ttys for deadfs.  Probably redundant. */
 	if (dsw->d_flags & D_TTY)
-		vp->v_flag |= VISTTY;
+		vp->v_vflag |= VV_ISTTY;
 
 	VOP_UNLOCK(vp, 0, td);
 	error = (*dsw->d_open)(dev, ap->a_mode, S_IFCHR, td);
@@ -401,7 +401,7 @@ loop2:
 			continue;
 		if ((bp->b_flags & B_DELWRI) == 0)
 			panic("spec_fsync: not dirty");
-		if ((vp->v_flag & VOBJBUF) && (bp->b_flags & B_CLUSTEROK)) {
+		if ((vp->v_vflag & VV_OBJBUF) && (bp->b_flags & B_CLUSTEROK)) {
 			BUF_UNLOCK(bp);
 			vfs_bio_awrite(bp);
 			splx(s);
@@ -420,11 +420,13 @@ loop2:
 	 * retry if dirty blocks still exist.
 	 */
 	if (ap->a_waitfor == MNT_WAIT) {
+		VI_LOCK(vp);
 		while (vp->v_numoutput) {
-			vp->v_flag |= VBWAIT;
-			(void)tsleep((caddr_t)&vp->v_numoutput, PRIBIO + 1,
-			    "spfsyn", 0);
+			vp->v_iflag |= VI_BWAIT;
+			msleep((caddr_t)&vp->v_numoutput, VI_MTX(vp),
+			    PRIBIO + 1, "spfsyn", 0);
 		}
+		VI_UNLOCK(vp);
 		if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
 			if (--maxretry != 0) {
 				splx(s);
@@ -462,7 +464,9 @@ spec_strategy(ap)
 		bp->b_flags &= ~B_VALIDSUSPWRT;
 		if (LIST_FIRST(&bp->b_dep) != NULL)
 			buf_start(bp);
-		if ((vp->v_flag & VCOPYONWRITE) && vp->v_rdev->si_copyonwrite &&
+		mp_fixme("This should require the vnode lock.");
+		if ((vp->v_vflag & VV_COPYONWRITE) &&
+		    vp->v_rdev->si_copyonwrite &&
 		    (error = (*vp->v_rdev->si_copyonwrite)(vp, bp)) != 0 &&
 		    error != EOPNOTSUPP) {
 			bp->b_io.bio_error = error;
@@ -580,6 +584,7 @@ spec_close(ap)
 	struct thread *td = ap->a_td;
 	dev_t dev = vp->v_rdev;
 
+	mp_fixme("Use of v_iflags bogusly locked.");
 	/*
 	 * Hack: a tty device that is a controlling terminal
 	 * has a reference from the session structure.
@@ -589,9 +594,15 @@ spec_close(ap)
 	 * if the reference count is 2 (this last descriptor
 	 * plus the session), release the reference from the session.
 	 */
+
+	/*
+	 * This needs to be rewritten to take the vp interlock into
+	 * consideration.
+	 */
+
 	oldvp = NULL;
 	sx_xlock(&proctree_lock);
-	if (vcount(vp) == 2 && td && (vp->v_flag & VXLOCK) == 0 &&
+	if (vcount(vp) == 2 && td && (vp->v_iflag & VI_XLOCK) == 0 &&
 	    vp == td->td_proc->p_session->s_ttyvp) {
 		SESS_LOCK(td->td_proc->p_session);
 		td->td_proc->p_session->s_ttyvp = NULL;
@@ -610,7 +621,7 @@ spec_close(ap)
 	 * sum of the reference counts on all the aliased
 	 * vnodes descends to one, we are on last close.
 	 */
-	if (vp->v_flag & VXLOCK) {
+	if (vp->v_iflag & VI_XLOCK) {
 		/* Forced close. */
 	} else if (devsw(dev)->d_flags & D_TRACKCLOSE) {
 		/* Keep device updated on status. */
diff --git a/sys/fs/udf/udf_vfsops.c b/sys/fs/udf/udf_vfsops.c
index 17cfd0b..adc8c0b 100644
--- a/sys/fs/udf/udf_vfsops.c
+++ b/sys/fs/udf/udf_vfsops.c
@@ -497,7 +497,7 @@ udf_root(struct mount *mp, struct vnode **vpp)
 		return error;
 
 	vp = *vpp;
-	vp->v_flag |= VROOT;
+	vp->v_vflag |= VV_ROOT;
 	udfmp->root_vp = vp;
 
 	return (0);
diff --git a/sys/fs/umapfs/umap_vfsops.c b/sys/fs/umapfs/umap_vfsops.c
index 9e5f0fc..adb419a 100644
--- a/sys/fs/umapfs/umap_vfsops.c
+++ b/sys/fs/umapfs/umap_vfsops.c
@@ -223,8 +223,9 @@ umapfs_mount(mp, path, data, ndp, td)
 	 * Keep a held reference to the root vnode.
 	 * It is vrele'd in umapfs_unmount.
 	 */
+	ASSERT_VOP_LOCKED(vp, "umapfs_mount");
 	umapm_rootvp = vp;
-	umapm_rootvp->v_flag |= VROOT;
+	umapm_rootvp->v_vflag |= VV_ROOT;
 	amp->umapm_rootvp = umapm_rootvp;
 	if (UMAPVPTOLOWERVP(umapm_rootvp)->v_mount->mnt_flag & MNT_LOCAL)
 		mp->mnt_flag |= MNT_LOCAL;
diff --git a/sys/fs/unionfs/union_subr.c b/sys/fs/unionfs/union_subr.c
index d7bbfb4..66a4013 100644
--- a/sys/fs/unionfs/union_subr.c
+++ b/sys/fs/unionfs/union_subr.c
@@ -373,7 +373,7 @@ union_allocvp(vpp, mp, dvp, upperdvp, cnp, uppervp, lowervp, docache)
 			if (lowervp != NULLVP)
 				VREF(lowervp);
 		}
-		vflag = VROOT;
+		vflag = VV_ROOT;
 	}
 
 loop:
@@ -563,7 +563,8 @@ loop:
 	MALLOC((*vpp)->v_data, void *, sizeof(struct union_node),
 		M_TEMP, M_WAITOK);
 
-	(*vpp)->v_flag |= vflag;
+	ASSERT_VOP_LOCKED(*vpp, "union_allocvp");
+	(*vpp)->v_vflag |= vflag;
 	if (uppervp)
 		(*vpp)->v_type = uppervp->v_type;
 	else
diff --git a/sys/fs/unionfs/union_vnops.c b/sys/fs/unionfs/union_vnops.c
index 8035799..227e817 100644
--- a/sys/fs/unionfs/union_vnops.c
+++ b/sys/fs/unionfs/union_vnops.c
@@ -190,7 +190,7 @@ union_lookup1(udvp, pdvp, vpp, cnp)
 	 * hierarchy.
 	 */
 	if (cnp->cn_flags & ISDOTDOT) {
-		while ((dvp != udvp) && (dvp->v_flag & VROOT)) {
+		while ((dvp != udvp) && (dvp->v_vflag & VV_ROOT)) {
 			/*
 			 * Don't do the NOCROSSMOUNT check
 			 * at this level.  By definition,
@@ -1625,7 +1625,7 @@ union_getwritemount(ap)
 
 	if (uvp == NULL) {
 		VI_LOCK(vp);
-		if (vp->v_flag & VFREE) {
+		if (vp->v_iflag & VI_FREE) {
 			VI_UNLOCK(vp);
 			return (EOPNOTSUPP);
 		}
@@ -1788,7 +1788,7 @@ union_createvobject(ap)
 {
 	struct vnode *vp = ap->a_vp;
 
-	vp->v_flag |= VOBJBUF;
+	vp->v_vflag |= VV_OBJBUF;
 	return (0);
 }
 
@@ -1803,7 +1803,7 @@ union_destroyvobject(ap)
 {
 	struct vnode *vp = ap->a_vp;
 
-	vp->v_flag &= ~VOBJBUF;
+	vp->v_vflag &= ~VV_OBJBUF;
 	return (0);
 }
 
diff --git a/sys/gnu/ext2fs/ext2_vnops.c b/sys/gnu/ext2fs/ext2_vnops.c
index 846e3ad..4474c23 100644
--- a/sys/gnu/ext2fs/ext2_vnops.c
+++ b/sys/gnu/ext2fs/ext2_vnops.c
@@ -718,10 +718,13 @@ loop:
 		goto loop;
 	}
 	if (ap->a_waitfor == MNT_WAIT) {
+		VI_LOCK(vp);
 		while (vp->v_numoutput) {
-			vp->v_flag |= VBWAIT;
-			tsleep(&vp->v_numoutput, PRIBIO + 1, "e2fsyn", 0);
+			vp->v_iflag |= VI_BWAIT;
+			msleep(&vp->v_numoutput, VI_MTX(vp), 
+			    PRIBIO + 1, "e2fsyn", 0);
 		}
+		VI_UNLOCK(vp);
 #if DIAGNOSTIC
 		if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
 			vprint("ext2_fsync: dirty", vp);
@@ -1861,7 +1864,7 @@ ext2_vinit(mntp, specops, fifoops, vpp)
 
 	}
 	if (ip->i_number == ROOTINO)
-		vp->v_flag |= VROOT;
+		vp->v_vflag |= VV_ROOT;
 	/*
 	 * Initialize modrev times
 	 */
diff --git a/sys/gnu/fs/ext2fs/ext2_vnops.c b/sys/gnu/fs/ext2fs/ext2_vnops.c
index 846e3ad..4474c23 100644
--- a/sys/gnu/fs/ext2fs/ext2_vnops.c
+++ b/sys/gnu/fs/ext2fs/ext2_vnops.c
@@ -718,10 +718,13 @@ loop:
 		goto loop;
 	}
 	if (ap->a_waitfor == MNT_WAIT) {
+		VI_LOCK(vp);
 		while (vp->v_numoutput) {
-			vp->v_flag |= VBWAIT;
-			tsleep(&vp->v_numoutput, PRIBIO + 1, "e2fsyn", 0);
+			vp->v_iflag |= VI_BWAIT;
+			msleep(&vp->v_numoutput, VI_MTX(vp), 
+			    PRIBIO + 1, "e2fsyn", 0);
 		}
+		VI_UNLOCK(vp);
 #if DIAGNOSTIC
 		if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
 			vprint("ext2_fsync: dirty", vp);
@@ -1861,7 +1864,7 @@ ext2_vinit(mntp, specops, fifoops, vpp)
 
 	}
 	if (ip->i_number == ROOTINO)
-		vp->v_flag |= VROOT;
+		vp->v_vflag |= VV_ROOT;
 	/*
 	 * Initialize modrev times
 	 */
diff --git a/sys/i386/ibcs2/imgact_coff.c b/sys/i386/ibcs2/imgact_coff.c
index 0a554d6..61ca412 100644
--- a/sys/i386/ibcs2/imgact_coff.c
+++ b/sys/i386/ibcs2/imgact_coff.c
@@ -473,7 +473,8 @@ exec_coff_imgact(imgp)
 	DPRINTF(("%s(%d):  returning successfully!\n", __FILE__, __LINE__));
 
 	/* Indicate that this file should not be modified */
-	imgp->vp->v_flag |= VTEXT;
+	mp_fixme("Unlocked v_flag access");
+	imgp->vp->v_vflag |= VV_TEXT;
 	return 0;
 }
 
diff --git a/sys/i386/linux/imgact_linux.c b/sys/i386/linux/imgact_linux.c
index 86e249a..5634619 100644
--- a/sys/i386/linux/imgact_linux.c
+++ b/sys/i386/linux/imgact_linux.c
@@ -215,7 +215,8 @@ exec_linux_imgact(imgp)
 
 	}
 	/* Indicate that this file should not be modified */
-	imgp->vp->v_flag |= VTEXT;
+	mp_fixme("Unlocked v_flag access");
+	imgp->vp->v_vflag |= VV_TEXT;
     }
     /* Fill in process VM information */
     vmspace->vm_tsize = round_page(a_out->a_text) >> PAGE_SHIFT;
diff --git a/sys/isofs/cd9660/cd9660_vfsops.c b/sys/isofs/cd9660/cd9660_vfsops.c
index 53715e7..980612e 100644
--- a/sys/isofs/cd9660/cd9660_vfsops.c
+++ b/sys/isofs/cd9660/cd9660_vfsops.c
@@ -869,7 +869,7 @@ cd9660_vget_internal(mp, ino, flags, vpp, relocated, isodir)
 	}
 	
 	if (ip->iso_extent == imp->root_extent)
-		vp->v_flag |= VROOT;
+		vp->v_vflag |= VV_ROOT;
 
 	/*
 	 * XXX need generation number?
diff --git a/sys/kern/imgact_aout.c b/sys/kern/imgact_aout.c
index b13837e..ba2f76b 100644
--- a/sys/kern/imgact_aout.c
+++ b/sys/kern/imgact_aout.c
@@ -240,7 +240,8 @@ exec_aout_imgact(imgp)
 	imgp->proc->p_sysent = &aout_sysvec;
 
 	/* Indicate that this file should not be modified */
-	imgp->vp->v_flag |= VTEXT;
+	mp_fixme("Unlocked vflag access.");
+	imgp->vp->v_vflag |= VV_TEXT;
 
 	return (0);
 }
diff --git a/sys/kern/imgact_elf.c b/sys/kern/imgact_elf.c
index 1b35000..92e86af 100644
--- a/sys/kern/imgact_elf.c
+++ b/sys/kern/imgact_elf.c
@@ -500,10 +500,11 @@ __elfN(load_file)(struct proc *p, const char *file, u_long *addr,
 	error = exec_map_first_page(imgp);
 	/*
 	 * Also make certain that the interpreter stays the same, so set
-	 * its VTEXT flag, too.
+	 * its VV_TEXT flag, too.
 	 */
 	if (error == 0)
-		nd->ni_vp->v_flag |= VTEXT;
+		nd->ni_vp->v_vflag |= VV_TEXT;
+
 	VOP_GETVOBJECT(nd->ni_vp, &imgp->object);
 	vm_object_reference(imgp->object);
 
@@ -628,10 +629,11 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
 	 * VTEXT now since from here on out, there are places we can have
 	 * a context switch.  Better safe than sorry; I really don't want
 	 * the file to change while it's being loaded.
+	 *
+	 * XXX We can't really set this flag safely without the vnode lock.
 	 */
-	mtx_lock(&imgp->vp->v_interlock);
-	imgp->vp->v_flag |= VTEXT;
-	mtx_unlock(&imgp->vp->v_interlock);
+	mp_fixme("This needs the vnode lock to be safe.");
+	imgp->vp->v_vflag |= VV_TEXT;
 
 	if ((error = exec_extract_strings(imgp)) != 0)
 		goto fail;
diff --git a/sys/kern/kern_mac.c b/sys/kern/kern_mac.c
index 43c03cc..6544f01 100644
--- a/sys/kern/kern_mac.c
+++ b/sys/kern/kern_mac.c
@@ -978,8 +978,9 @@ mac_update_vnode_from_mount(struct vnode *vp, struct mount *mp)
 	MAC_PERFORM(update_vnode_from_mount, vp, &vp->v_label, mp,
 	    &mp->mnt_fslabel);
 
+	ASSERT_VOP_LOCKED(vp, "mac_update_vnode_from_mount");
 	if (mac_cache_fslabel_in_vnode)
-		vp->v_flag |= VCACHEDLABEL;
+		vp->v_vflag |= VV_CACHEDLABEL;
 }
 
 /*
@@ -1031,7 +1032,7 @@ vop_stdrefreshlabel_ea(struct vop_refreshlabel_args *ap)
 	if (error == 0)
 		error = mac_update_vnode_from_externalized(vp, &extmac);
 	if (error == 0)
-		vp->v_flag |= VCACHEDLABEL;
+		vp->v_vflag |= VV_CACHEDLABEL;
 	else {
 		struct vattr va;
 
@@ -1084,7 +1085,7 @@ vn_refreshlabel(struct vnode *vp, struct ucred *cred)
 		return (EBADF);
 	}
 
-	if (vp->v_flag & VCACHEDLABEL) {
+	if (vp->v_vflag & VV_CACHEDLABEL) {
 		mac_vnode_label_cache_hits++;
 		return (0);
 	} else
@@ -1124,6 +1125,7 @@ vop_stdcreatevnode_ea(struct vnode *dvp, struct vnode *tvp, struct ucred *cred)
 	struct mac extmac;
 	int error;
 
+	ASSERT_VOP_LOCKED(tvp, "vop_stdcreatevnode_ea");
 	if ((dvp->v_mount->mnt_flag & MNT_MULTILABEL) == 0) {
 		mac_update_vnode_from_mount(tvp, tvp->v_mount);
 	} else {
@@ -1156,7 +1158,7 @@ vop_stdcreatevnode_ea(struct vnode *dvp, struct vnode *tvp, struct ucred *cred)
 		    FREEBSD_MAC_EXTATTR_NAMESPACE, FREEBSD_MAC_EXTATTR_NAME,
 		    sizeof(extmac), (char *)&extmac, curthread);
 		if (error == 0)
-			tvp->v_flag |= VCACHEDLABEL;
+			tvp->v_vflag |= VV_CACHEDLABEL;
 		else {
 #if 0
 			/*
@@ -2771,7 +2773,7 @@ vop_stdsetlabel_ea(struct vop_setlabel_args *ap)
 
 	mac_relabel_vnode(ap->a_cred, vp, intlabel);
 
-	vp->v_flag |= VCACHEDLABEL;
+	vp->v_vflag |= VV_CACHEDLABEL;
 
 	return (0);
 }
diff --git a/sys/kern/vfs_bio.c b/sys/kern/vfs_bio.c
index 548e4fb..e0d623c 100644
--- a/sys/kern/vfs_bio.c
+++ b/sys/kern/vfs_bio.c
@@ -2107,7 +2107,7 @@ inmem(struct vnode * vp, daddr_t blkno)
 		return 1;
 	if (vp->v_mount == NULL)
 		return 0;
-	if (VOP_GETVOBJECT(vp, &obj) != 0 || (vp->v_flag & VOBJBUF) == 0)
+	if (VOP_GETVOBJECT(vp, &obj) != 0 || (vp->v_vflag & VV_OBJBUF) == 0)
 		return 0;
 
 	size = PAGE_SIZE;
@@ -2408,7 +2408,8 @@ loop:
 			bsize = size;
 
 		offset = blkno * bsize;
-		vmio = (VOP_GETVOBJECT(vp, NULL) == 0) && (vp->v_flag & VOBJBUF);
+		vmio = (VOP_GETVOBJECT(vp, NULL) == 0) &&
+		    (vp->v_vflag & VV_OBJBUF);
 		maxsize = vmio ? size + (offset & PAGE_MASK) : size;
 		maxsize = imax(maxsize, bsize);
 
@@ -2912,11 +2913,12 @@ bufdone(struct buf *bp)
 		obj = bp->b_object;
 
 #if defined(VFS_BIO_DEBUG)
+		mp_fixme("usecount and vflag accessed without locks.");
 		if (vp->v_usecount == 0) {
 			panic("biodone: zero vnode ref count");
 		}
 
-		if ((vp->v_flag & VOBJBUF) == 0) {
+		if ((vp->v_vflag & VV_OBJBUF) == 0) {
 			panic("biodone: vnode is not setup for merged cache");
 		}
 #endif
diff --git a/sys/kern/vfs_cache.c b/sys/kern/vfs_cache.c
index be79fc2..6e68c2f 100644
--- a/sys/kern/vfs_cache.c
+++ b/sys/kern/vfs_cache.c
@@ -726,8 +726,9 @@ __getcwd(td, uap)
 	fdp = td->td_proc->p_fd;
 	slash_prefixed = 0;
 	FILEDESC_LOCK(fdp);
+	mp_fixme("No vnode locking done!");
 	for (vp = fdp->fd_cdir; vp != fdp->fd_rdir && vp != rootvnode;) {
-		if (vp->v_flag & VROOT) {
+		if (vp->v_vflag & VV_ROOT) {
 			if (vp->v_mount == NULL) {	/* forced unmount */
 				FILEDESC_UNLOCK(fdp);
 				free(buf, M_TEMP);
@@ -827,6 +828,7 @@ vn_fullpath(struct thread *td, struct vnode *vn, char **retbuf, char **freebuf)
 		return (ENODEV);
 	if (vn == NULL)
 		return (EINVAL);
+	ASSERT_VOP_LOCKED(vp, "vn_fullpath");
 	buf = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
 	bp = buf + MAXPATHLEN - 1;
 	*bp = '\0';
@@ -834,7 +836,7 @@ vn_fullpath(struct thread *td, struct vnode *vn, char **retbuf, char **freebuf)
 	slash_prefixed = 0;
 	FILEDESC_LOCK(fdp);
 	for (vp = vn; vp != fdp->fd_rdir && vp != rootvnode;) {
-		if (vp->v_flag & VROOT) {
+		if (vp->v_vflag & VV_ROOT) {
 			if (vp->v_mount == NULL) {	/* forced unmount */
 				FILEDESC_UNLOCK(fdp);
 				free(buf, M_TEMP);
diff --git a/sys/kern/vfs_default.c b/sys/kern/vfs_default.c
index abc8ebd..6ad13d5 100644
--- a/sys/kern/vfs_default.c
+++ b/sys/kern/vfs_default.c
@@ -595,7 +595,7 @@ retry:
 	}
 
 	KASSERT(vp->v_object != NULL, ("vfs_object_create: NULL object"));
-	vp->v_flag |= VOBJBUF;
+	vp->v_vflag |= VV_OBJBUF;
 
 retn:
 	return (error);
diff --git a/sys/kern/vfs_extattr.c b/sys/kern/vfs_extattr.c
index f02f62f..197829b 100644
--- a/sys/kern/vfs_extattr.c
+++ b/sys/kern/vfs_extattr.c
@@ -1155,7 +1155,8 @@ restart:
 		 *
 		 * XXX: can this only be a VDIR case?
 		 */
-		if (vp->v_flag & VROOT)
+		mp_fixme("Accessing vflags w/o the vn lock.");
+		if (vp->v_vflag & VV_ROOT)
 			error = EBUSY;
 	}
 	if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
@@ -2778,7 +2779,7 @@ restart:
 	/*
 	 * The root of a mounted filesystem cannot be deleted.
 	 */
-	if (vp->v_flag & VROOT) {
+	if (vp->v_vflag & VV_ROOT) {
 		error = EBUSY;
 		goto out;
 	}
@@ -2939,7 +2940,8 @@ unionread:
 				return (error);
 			}
 		}
-		if ((vp->v_flag & VROOT) &&
+		mp_fixme("Accessing vflags w/o vn lock.");
+		if ((vp->v_vflag & VV_ROOT) &&
 		    (vp->v_mount->mnt_flag & MNT_UNION)) {
 			struct vnode *tvp = vp;
 			vp = vp->v_mount->mnt_vnodecovered;
@@ -3030,7 +3032,8 @@ unionread:
 				return (error);
 			}
 		}
-		if ((vp->v_flag & VROOT) &&
+		mp_fixme("Accessing vflag without vn lock.");
+		if ((vp->v_vflag & VV_ROOT) &&
 		    (vp->v_mount->mnt_flag & MNT_UNION)) {
 			struct vnode *tvp = vp;
 			vp = vp->v_mount->mnt_vnodecovered;
diff --git a/sys/kern/vfs_lookup.c b/sys/kern/vfs_lookup.c
index e8cabd5..db1b342 100644
--- a/sys/kern/vfs_lookup.c
+++ b/sys/kern/vfs_lookup.c
@@ -451,7 +451,7 @@ dirloop:
 				VREF(dp);
 				goto nextname;
 			}
-			if ((dp->v_flag & VROOT) == 0 ||
+			if ((dp->v_vflag & VV_ROOT) == 0 ||
 			    (cnp->cn_flags & NOCROSSMOUNT))
 				break;
 			if (dp->v_mount == NULL) {	/* forced unmount */
@@ -485,7 +485,7 @@ unionlookup:
 		printf("not found\n");
 #endif
 		if ((error == ENOENT) &&
-		    (dp->v_flag & VROOT) && (dp->v_mount != NULL) &&
+		    (dp->v_vflag & VV_ROOT) && (dp->v_mount != NULL) &&
 		    (dp->v_mount->mnt_flag & MNT_UNION)) {
 			tdp = dp;
 			dp = dp->v_mount->mnt_vnodecovered;
diff --git a/sys/kern/vfs_mount.c b/sys/kern/vfs_mount.c
index 3dd4b06..ee77f0b 100644
--- a/sys/kern/vfs_mount.c
+++ b/sys/kern/vfs_mount.c
@@ -505,7 +505,7 @@ vfs_nmount(td, fsflags, fsoptions)
 	NDFREE(&nd, NDF_ONLY_PNBUF);
 	vp = nd.ni_vp;
 	if (fsflags & MNT_UPDATE) {
-		if ((vp->v_flag & VROOT) == 0) {
+		if ((vp->v_vflag & VV_ROOT) == 0) {
 			vput(vp);
 			error = EINVAL;
 			goto bad;
@@ -539,16 +539,17 @@ vfs_nmount(td, fsflags, fsoptions)
 			error = EBUSY;
 			goto bad;
 		}
-		mtx_lock(&vp->v_interlock);
-		if ((vp->v_flag & VMOUNT) != 0 || vp->v_mountedhere != NULL) {
-			mtx_unlock(&vp->v_interlock);
+		VI_LOCK(vp);
+		if ((vp->v_iflag & VI_MOUNT) != 0 ||
+		    vp->v_mountedhere != NULL) {
+			VI_UNLOCK(vp);
 			vfs_unbusy(mp, td);
 			vput(vp);
 			error = EBUSY;
 			goto bad;
 		}
-		vp->v_flag |= VMOUNT;
-		mtx_unlock(&vp->v_interlock);
+		vp->v_iflag |= VI_MOUNT;
+		VI_UNLOCK(vp);
 		mp->mnt_flag |= fsflags &
 		    (MNT_RELOAD | MNT_FORCE | MNT_UPDATE | MNT_SNAPSHOT);
 		VOP_UNLOCK(vp, 0, td);
@@ -616,16 +617,16 @@ vfs_nmount(td, fsflags, fsoptions)
 			goto bad;
 		}
 	}
-	mtx_lock(&vp->v_interlock);
-	if ((vp->v_flag & VMOUNT) != 0 ||
+	VI_LOCK(vp);
+	if ((vp->v_iflag & VI_MOUNT) != 0 ||
 	    vp->v_mountedhere != NULL) {
-		mtx_unlock(&vp->v_interlock);
+		VI_UNLOCK(vp);
 		vput(vp);
 		error = EBUSY;
 		goto bad;
 	}
-	vp->v_flag |= VMOUNT;
-	mtx_unlock(&vp->v_interlock);
+	vp->v_iflag |= VI_MOUNT;
+	VI_UNLOCK(vp);
 
 	/*
 	 * Allocate and initialize the filesystem.
@@ -660,9 +661,9 @@ update:
 	if (mp->mnt_op->vfs_mount != NULL) {
 		printf("%s doesn't support the new mount syscall\n",
 		    mp->mnt_vfc->vfc_name);
-		mtx_lock(&vp->v_interlock);
-		vp->v_flag &= ~VMOUNT;
-		mtx_unlock(&vp->v_interlock);
+		VI_LOCK(vp);
+		vp->v_iflag &= ~VI_MOUNT;
+		VI_UNLOCK(vp);
 		if (mp->mnt_flag & MNT_UPDATE)
 			vfs_unbusy(mp, td);
 		else {
@@ -722,9 +723,9 @@ update:
 			mp->mnt_syncer = NULL;
 		}
 		vfs_unbusy(mp, td);
-		mtx_lock(&vp->v_interlock);
-		vp->v_flag &= ~VMOUNT;
-		mtx_unlock(&vp->v_interlock);
+		VI_LOCK(vp);
+		vp->v_iflag &= ~VI_MOUNT;
+		VI_UNLOCK(vp);
 		vrele(vp);
 		return (error);
 	}
@@ -736,10 +737,10 @@ update:
 	if (!error) {
 		struct vnode *newdp;
 
-		mtx_lock(&vp->v_interlock);
-		vp->v_flag &= ~VMOUNT;
+		VI_LOCK(vp);
+		vp->v_iflag &= ~VI_MOUNT;
 		vp->v_mountedhere = mp;
-		mtx_unlock(&vp->v_interlock);
+		VI_UNLOCK(vp);
 		mtx_lock(&mountlist_mtx);
 		TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
 		mtx_unlock(&mountlist_mtx);
@@ -756,9 +757,9 @@ update:
 			goto bad;
 		}
 	} else {
-		mtx_lock(&vp->v_interlock);
-		vp->v_flag &= ~VMOUNT;
-		mtx_unlock(&vp->v_interlock);
+		VI_LOCK(vp);
+		vp->v_iflag &= ~VI_MOUNT;
+		VI_UNLOCK(vp);
 		mp->mnt_vfc->vfc_refcount--;
 		vfs_unbusy(mp, td);
 #ifdef MAC
@@ -880,7 +881,7 @@ vfs_mount(td, fstype, fspath, fsflags, fsdata)
 	NDFREE(&nd, NDF_ONLY_PNBUF);
 	vp = nd.ni_vp;
 	if (fsflags & MNT_UPDATE) {
-		if ((vp->v_flag & VROOT) == 0) {
+		if ((vp->v_vflag & VV_ROOT) == 0) {
 			vput(vp);
 			return (EINVAL);
 		}
@@ -911,15 +912,16 @@ vfs_mount(td, fstype, fspath, fsflags, fsdata)
 			vput(vp);
 			return (EBUSY);
 		}
-		mtx_lock(&vp->v_interlock);
-		if ((vp->v_flag & VMOUNT) != 0 || vp->v_mountedhere != NULL) {
-			mtx_unlock(&vp->v_interlock);
+		VI_LOCK(vp);
+		if ((vp->v_iflag & VI_MOUNT) != 0 ||
+		    vp->v_mountedhere != NULL) {
+			VI_UNLOCK(vp);
 			vfs_unbusy(mp, td);
 			vput(vp);
 			return (EBUSY);
 		}
-		vp->v_flag |= VMOUNT;
-		mtx_unlock(&vp->v_interlock);
+		vp->v_iflag |= VI_MOUNT;
+		VI_UNLOCK(vp);
 		mp->mnt_flag |= fsflags &
 		    (MNT_RELOAD | MNT_FORCE | MNT_UPDATE | MNT_SNAPSHOT);
 		VOP_UNLOCK(vp, 0, td);
@@ -983,15 +985,15 @@ vfs_mount(td, fstype, fspath, fsflags, fsdata)
 			return (ENODEV);
 		}
 	}
-	mtx_lock(&vp->v_interlock);
-	if ((vp->v_flag & VMOUNT) != 0 ||
+	VI_LOCK(vp);
+	if ((vp->v_iflag & VI_MOUNT) != 0 ||
 	    vp->v_mountedhere != NULL) {
-		mtx_unlock(&vp->v_interlock);
+		VI_UNLOCK(vp);
 		vput(vp);
 		return (EBUSY);
 	}
-	vp->v_flag |= VMOUNT;
-	mtx_unlock(&vp->v_interlock);
+	vp->v_iflag |= VI_MOUNT;
+	VI_UNLOCK(vp);
 
 	/*
 	 * Allocate and initialize the filesystem.
@@ -1024,9 +1026,9 @@ update:
 	if (mp->mnt_op->vfs_mount == NULL) {
 		printf("%s doesn't support the old mount syscall\n",
 		    mp->mnt_vfc->vfc_name);
-		mtx_lock(&vp->v_interlock);
-		vp->v_flag &= ~VMOUNT;
-		mtx_unlock(&vp->v_interlock);
+		VI_LOCK(vp);
+		vp->v_iflag &= ~VI_MOUNT;
+		VI_UNLOCK(vp);
 		if (mp->mnt_flag & MNT_UPDATE)
 			vfs_unbusy(mp, td);
 		else {
@@ -1075,9 +1077,9 @@ update:
 			mp->mnt_syncer = NULL;
 		}
 		vfs_unbusy(mp, td);
-		mtx_lock(&vp->v_interlock);
-		vp->v_flag &= ~VMOUNT;
-		mtx_unlock(&vp->v_interlock);
+		VI_LOCK(vp);
+		vp->v_iflag &= ~VI_MOUNT;
+		VI_UNLOCK(vp);
 		vrele(vp);
 		return (error);
 	}
@@ -1089,10 +1091,11 @@ update:
 	if (!error) {
 		struct vnode *newdp;
 
-		mtx_lock(&vp->v_interlock);
-		vp->v_flag &= ~VMOUNT;
+		mp_fixme("Does interlock protect mounted here or not?");
+		VI_LOCK(vp);
+		vp->v_iflag &= ~VI_MOUNT;
 		vp->v_mountedhere = mp;
-		mtx_unlock(&vp->v_interlock);
+		VI_UNLOCK(vp);
 		mtx_lock(&mountlist_mtx);
 		TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
 		mtx_unlock(&mountlist_mtx);
@@ -1107,9 +1110,9 @@ update:
 		if ((error = VFS_START(mp, 0, td)) != 0)
 			vrele(vp);
 	} else {
-		mtx_lock(&vp->v_interlock);
-		vp->v_flag &= ~VMOUNT;
-		mtx_unlock(&vp->v_interlock);
+		VI_LOCK(vp);
+		vp->v_iflag &= ~VI_MOUNT;
+		VI_UNLOCK(vp);
 		mp->mnt_vfc->vfc_refcount--;
 		vfs_unbusy(mp, td);
 #ifdef MAC
@@ -1226,7 +1229,7 @@ unmount(td, uap)
 	/*
 	 * Must be the root of the filesystem
 	 */
-	if ((vp->v_flag & VROOT) == 0) {
+	if ((vp->v_vflag & VV_ROOT) == 0) {
 		vput(vp);
 		return (EINVAL);
 	}
diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index adf38ee..1cc90ea 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -572,18 +572,16 @@ vlrureclaim(struct mount *mp, int count)
 
 		if (vp->v_type != VNON &&
 		    vp->v_type != VBAD &&
-		    VMIGHTFREE(vp) &&           /* critical path opt */
-		    (vp->v_object == NULL || vp->v_object->resident_page_count < trigger) &&
-		    mtx_trylock(&vp->v_interlock)
-		) {
-			mtx_unlock(&mntvnode_mtx);
-			if (VMIGHTFREE(vp)) {
+		    VI_TRYLOCK(vp)) {
+			if (VMIGHTFREE(vp) &&           /* critical path opt */
+			    (vp->v_object == NULL ||
+			    vp->v_object->resident_page_count < trigger)) {
+				mtx_unlock(&mntvnode_mtx);
 				vgonel(vp, curthread);
 				done++;
-			} else {
-				mtx_unlock(&vp->v_interlock);
-			}
-			mtx_lock(&mntvnode_mtx);
+				mtx_lock(&mntvnode_mtx);
+			} else
+				VI_UNLOCK(vp);
 		}
 		--count;
 	}
@@ -771,8 +769,9 @@ getnewvnode(tag, mp, vops, vpp)
 		}
 	}
 	if (vp) {
-		vp->v_flag |= VDOOMED;
-		vp->v_flag &= ~VFREE;
+		mp_fixme("Unlocked v_iflags access.\n");
+		vp->v_iflag |= VI_DOOMED;
+		vp->v_iflag &= ~VI_FREE;
 		freevnodes--;
 		mtx_unlock(&vnode_free_list_mtx);
 		cache_purge(vp);
@@ -806,7 +805,8 @@ getnewvnode(tag, mp, vops, vpp)
 #ifdef MAC
 		mac_destroy_vnode(vp);
 #endif
-		vp->v_flag = 0;
+		vp->v_iflag = 0;
+		vp->v_vflag = 0;
 		vp->v_lastw = 0;
 		vp->v_lasta = 0;
 		vp->v_cstart = 0;
@@ -893,13 +893,15 @@ vwakeup(bp)
 
 	bp->b_flags &= ~B_WRITEINPROG;
 	if ((vp = bp->b_vp)) {
+		VI_LOCK(vp);
 		vp->v_numoutput--;
 		if (vp->v_numoutput < 0)
 			panic("vwakeup: neg numoutput");
-		if ((vp->v_numoutput == 0) && (vp->v_flag & VBWAIT)) {
-			vp->v_flag &= ~VBWAIT;
+		if ((vp->v_numoutput == 0) && (vp->v_iflag & VI_BWAIT)) {
+			vp->v_iflag &= ~VI_BWAIT;
 			wakeup(&vp->v_numoutput);
 		}
+		VI_UNLOCK(vp);
 	}
 }
 
@@ -923,24 +925,33 @@ vinvalbuf(vp, flags, cred, td, slpflag, slptimeo)
 
 	if (flags & V_SAVE) {
 		s = splbio();
+		VI_LOCK(vp);
 		while (vp->v_numoutput) {
-			vp->v_flag |= VBWAIT;
-			error = tsleep(&vp->v_numoutput,
+			vp->v_iflag |= VI_BWAIT;
+			error = msleep(&vp->v_numoutput, VI_MTX(vp),
 			    slpflag | (PRIBIO + 1), "vinvlbuf", slptimeo);
 			if (error) {
+				VI_UNLOCK(vp);
 				splx(s);
 				return (error);
 			}
 		}
 		if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
 			splx(s);
+			VI_UNLOCK(vp);
 			if ((error = VOP_FSYNC(vp, cred, MNT_WAIT, td)) != 0)
 				return (error);
+			/*
+			 * XXX We could save a lock/unlock if this was only
+			 * enabled under INVARIANTS
+			 */
+			VI_LOCK(vp);
 			s = splbio();
 			if (vp->v_numoutput > 0 ||
 			    !TAILQ_EMPTY(&vp->v_dirtyblkhd))
 				panic("vinvalbuf: dirty bufs");
 		}
+		VI_UNLOCK(vp);
 		splx(s);
 	}
 	s = splbio();
@@ -969,28 +980,30 @@ vinvalbuf(vp, flags, cred, td, slpflag, slptimeo)
 	 * have write I/O in-progress but if there is a VM object then the
 	 * VM object can also have read-I/O in-progress.
 	 */
+	VI_LOCK(vp);
 	do {
 		while (vp->v_numoutput > 0) {
-			vp->v_flag |= VBWAIT;
-			tsleep(&vp->v_numoutput, PVM, "vnvlbv", 0);
+			vp->v_iflag |= VI_BWAIT;
+			msleep(&vp->v_numoutput, VI_MTX(vp), PVM, "vnvlbv", 0);
 		}
+		VI_UNLOCK(vp);
 		if (VOP_GETVOBJECT(vp, &object) == 0) {
 			while (object->paging_in_progress)
 			vm_object_pip_sleep(object, "vnvlbx");
 		}
+		VI_LOCK(vp);
 	} while (vp->v_numoutput > 0);
+	VI_UNLOCK(vp);
 
 	splx(s);
 
 	/*
 	 * Destroy the copy in the VM cache, too.
 	 */
-	mtx_lock(&vp->v_interlock);
 	if (VOP_GETVOBJECT(vp, &object) == 0) {
 		vm_object_page_remove(object, 0, 0,
 			(flags & V_SAVE) ? TRUE : FALSE);
 	}
-	mtx_unlock(&vp->v_interlock);
 
 	if ((flags & (V_ALT | V_NORMAL)) == 0 &&
 	    (!TAILQ_EMPTY(&vp->v_dirtyblkhd) ||
@@ -1156,12 +1169,13 @@ restartsync:
 
 		}
 	}
-
+	
+	VI_LOCK(vp);
 	while (vp->v_numoutput > 0) {
-		vp->v_flag |= VBWAIT;
-		tsleep(&vp->v_numoutput, PVM, "vbtrunc", 0);
+		vp->v_iflag |= VI_BWAIT;
+		msleep(&vp->v_numoutput, VI_MTX(vp), PVM, "vbtrunc", 0);
 	}
-
+	VI_UNLOCK(vp);
 	splx(s);
 
 	vnode_pager_setsize(vp, length);
@@ -1407,10 +1421,12 @@ brelvp(bp)
 	s = splbio();
 	if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
 		buf_vlist_remove(bp);
-	if ((vp->v_flag & VONWORKLST) && TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
-		vp->v_flag &= ~VONWORKLST;
+	VI_LOCK(vp);
+	if ((vp->v_iflag & VI_ONWORKLST) && TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
+		vp->v_iflag &= ~VI_ONWORKLST;
 		LIST_REMOVE(vp, v_synclist);
 	}
+	VI_UNLOCK(vp);
 	splx(s);
 	bp->b_vp = (struct vnode *) 0;
 	vdrop(vp);
@@ -1427,17 +1443,19 @@ vn_syncer_add_to_worklist(struct vnode *vp, int delay)
 	int s, slot;
 
 	s = splbio();
+	mtx_assert(VI_MTX(vp), MA_OWNED);
 
-	if (vp->v_flag & VONWORKLST) {
+	if (vp->v_iflag & VI_ONWORKLST)
 		LIST_REMOVE(vp, v_synclist);
-	}
+	else
+		vp->v_iflag |= VI_ONWORKLST;
 
 	if (delay > syncer_maxdelay - 2)
 		delay = syncer_maxdelay - 2;
 	slot = (syncer_delayno + delay) & syncer_mask;
 
 	LIST_INSERT_HEAD(&syncer_workitem_pending[slot], vp, v_synclist);
-	vp->v_flag |= VONWORKLST;
+
 	splx(s);
 }
 
@@ -1509,7 +1527,9 @@ sched_sync(void)
 				 * position and then add us back in at a later
 				 * position.
 				 */
+				VI_LOCK(vp);
 				vn_syncer_add_to_worklist(vp, syncdelay);
+				VI_UNLOCK(vp);
 			}
 			splx(s);
 		}
@@ -1653,7 +1673,8 @@ reassignbuf(bp, newvp)
 	 * of clean buffers.
 	 */
 	if (bp->b_flags & B_DELWRI) {
-		if ((newvp->v_flag & VONWORKLST) == 0) {
+		VI_LOCK(newvp);
+		if ((newvp->v_iflag & VI_ONWORKLST) == 0) {
 			switch (newvp->v_type) {
 			case VDIR:
 				delay = dirdelay;
@@ -1669,15 +1690,18 @@ reassignbuf(bp, newvp)
 			}
 			vn_syncer_add_to_worklist(newvp, delay);
 		}
+		VI_UNLOCK(newvp);
 		buf_vlist_add(bp, newvp, BX_VNDIRTY);
 	} else {
 		buf_vlist_add(bp, newvp, BX_VNCLEAN);
 
-		if ((newvp->v_flag & VONWORKLST) &&
+		VI_LOCK(newvp);
+		if ((newvp->v_iflag & VI_ONWORKLST) &&
 		    TAILQ_EMPTY(&newvp->v_dirtyblkhd)) {
-			newvp->v_flag &= ~VONWORKLST;
+			newvp->v_iflag &= ~VI_ONWORKLST;
 			LIST_REMOVE(newvp, v_synclist);
 		}
+		VI_UNLOCK(newvp);
 	}
 	if (bp->b_vp != newvp) {
 		bp->b_vp = newvp;
@@ -1811,19 +1835,19 @@ vget(vp, flags, td)
 	 * If the vnode is in the process of being cleaned out for
 	 * another use, we wait for the cleaning to finish and then
 	 * return failure. Cleaning is determined by checking that
-	 * the VXLOCK flag is set.
+	 * the VI_XLOCK flag is set.
 	 */
 	if ((flags & LK_INTERLOCK) == 0)
-		mtx_lock(&vp->v_interlock);
-	if (vp->v_flag & VXLOCK) {
+		VI_LOCK(vp);
+	if (vp->v_iflag & VI_XLOCK) {
 		if (vp->v_vxproc == curthread) {
 #if 0
 			/* this can now occur in normal operation */
 			log(LOG_INFO, "VXLOCK interlock avoided\n");
 #endif
 		} else {
-			vp->v_flag |= VXWANT;
-			msleep(vp, &vp->v_interlock, PINOD | PDROP, "vget", 0);
+			vp->v_iflag |= VI_XWANT;
+			msleep(vp, VI_MTX(vp), PINOD | PDROP, "vget", 0);
 			return (ENOENT);
 		}
 	}
@@ -1842,17 +1866,17 @@ vget(vp, flags, td)
 			 * before sleeping so that multiple processes do
 			 * not try to recycle it.
 			 */
-			mtx_lock(&vp->v_interlock);
+			VI_LOCK(vp);
 			vp->v_usecount--;
 			if (VSHOULDFREE(vp))
 				vfree(vp);
 			else
 				vlruvp(vp);
-			mtx_unlock(&vp->v_interlock);
+			VI_UNLOCK(vp);
 		}
 		return (error);
 	}
-	mtx_unlock(&vp->v_interlock);
+	VI_UNLOCK(vp);
 	return (0);
 }
 
@@ -1879,7 +1903,7 @@ vrele(vp)
 
 	KASSERT(vp != NULL, ("vrele: null vp"));
 
-	mtx_lock(&vp->v_interlock);
+	VI_LOCK(vp);
 
 	/* Skip this v_writecount check if we're going to panic below. */
 	KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1,
@@ -1888,7 +1912,7 @@ vrele(vp)
 	if (vp->v_usecount > 1) {
 
 		vp->v_usecount--;
-		mtx_unlock(&vp->v_interlock);
+		VI_UNLOCK(vp);
 
 		return;
 	}
@@ -1903,15 +1927,17 @@ vrele(vp)
 		 */
 		if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, td) == 0)
 			VOP_INACTIVE(vp, td);
+		VI_LOCK(vp);
 		if (VSHOULDFREE(vp))
 			vfree(vp);
 		else
 			vlruvp(vp);
+		VI_UNLOCK(vp);
 
 	} else {
 #ifdef DIAGNOSTIC
 		vprint("vrele: negative ref count", vp);
-		mtx_unlock(&vp->v_interlock);
+		VI_UNLOCK(vp);
 #endif
 		panic("vrele: negative ref cnt");
 	}
@@ -1949,12 +1975,14 @@ vput(vp)
 		 * If we are doing a vput, the node is already locked,
 		 * so we just need to release the vnode mutex.
 		 */
-		mtx_unlock(&vp->v_interlock);
+		VI_UNLOCK(vp);
 		VOP_INACTIVE(vp, td);
+		VI_LOCK(vp);
 		if (VSHOULDFREE(vp))
 			vfree(vp);
 		else
 			vlruvp(vp);
+		VI_UNLOCK(vp);
 
 	} else {
 #ifdef DIAGNOSTIC
@@ -1975,8 +2003,10 @@ vhold(vp)
 
 	s = splbio();
 	vp->v_holdcnt++;
+	VI_LOCK(vp);
 	if (VSHOULDBUSY(vp))
 		vbusy(vp);
+	VI_UNLOCK(vp);
 	splx(s);
 }
 
@@ -1994,10 +2024,12 @@ vdrop(vp)
 	if (vp->v_holdcnt <= 0)
 		panic("vdrop: holdcnt");
 	vp->v_holdcnt--;
+	VI_LOCK(vp);
 	if (VSHOULDFREE(vp))
 		vfree(vp);
 	else
 		vlruvp(vp);
+	VI_UNLOCK(vp);
 	splx(s);
 }
 
@@ -2012,7 +2044,7 @@ vdrop(vp)
  * If WRITECLOSE is set, only flush out regular file vnodes open for
  * writing.
  *
- * SKIPSYSTEM causes any vnodes marked VSYSTEM to be skipped.
+ * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped.
  *
  * `rootrefs' specifies the base reference count for the root vnode
  * of this filesystem. The root vnode is considered busy if its
@@ -2061,12 +2093,12 @@ loop:
 		nvp = TAILQ_NEXT(vp, v_nmntvnodes);
 
 		mtx_unlock(&mntvnode_mtx);
-		mtx_lock(&vp->v_interlock);
+		VI_LOCK(vp);
 		/*
-		 * Skip over a vnodes marked VSYSTEM.
+		 * Skip over a vnodes marked VV_SYSTEM.
 		 */
-		if ((flags & SKIPSYSTEM) && (vp->v_flag & VSYSTEM)) {
-			mtx_unlock(&vp->v_interlock);
+		if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) {
+			VI_UNLOCK(vp);
 			mtx_lock(&mntvnode_mtx);
 			continue;
 		}
@@ -2075,6 +2107,7 @@ loop:
 		 * files (even if open only for reading) and regular file
 		 * vnodes open for writing.
 		 */
+		mp_fixme("Getattr called with interlock held!");
 		if ((flags & WRITECLOSE) &&
 		    (vp->v_type == VNON ||
 		    (VOP_GETATTR(vp, &vattr, td->td_ucred, td) == 0 &&
@@ -2105,6 +2138,7 @@ loop:
 				vgonel(vp, td);
 			} else {
 				vclean(vp, 0, td);
+				VI_UNLOCK(vp);
 				vp->v_op = spec_vnodeop_p;
 				insmntque(vp, (struct mount *) 0);
 			}
@@ -2115,7 +2149,7 @@ loop:
 		if (busyprt)
 			vprint("vflush: busy vnode", vp);
 #endif
-		mtx_unlock(&vp->v_interlock);
+		VI_UNLOCK(vp);
 		mtx_lock(&mntvnode_mtx);
 		busy++;
 	}
@@ -2173,6 +2207,7 @@ vclean(vp, flags, td)
 {
 	int active;
 
+	mtx_assert(VI_MTX(vp), MA_OWNED);
 	/*
 	 * Check to see if the vnode is in use. If so we have to reference it
 	 * before we clean it out so that its count cannot fall to zero and
@@ -2185,9 +2220,9 @@ vclean(vp, flags, td)
 	 * Prevent the vnode from being recycled or brought into use while we
 	 * clean it out.
 	 */
-	if (vp->v_flag & VXLOCK)
+	if (vp->v_iflag & VI_XLOCK)
 		panic("vclean: deadlock");
-	vp->v_flag |= VXLOCK;
+	vp->v_iflag |= VI_XLOCK;
 	vp->v_vxproc = curthread;
 	/*
 	 * Even if the count is zero, the VOP_INACTIVE routine may still
@@ -2241,7 +2276,7 @@ vclean(vp, flags, td)
 		 * Inline copy of vrele() since VOP_INACTIVE
 		 * has already been called.
 		 */
-		mtx_lock(&vp->v_interlock);
+		VI_LOCK(vp);
 		if (--vp->v_usecount <= 0) {
 #ifdef DIAGNOSTIC
 			if (vp->v_usecount < 0 || vp->v_writecount != 0) {
@@ -2251,13 +2286,14 @@ vclean(vp, flags, td)
 #endif
 			vfree(vp);
 		}
-		mtx_unlock(&vp->v_interlock);
+		VI_UNLOCK(vp);
 	}
 
 	cache_purge(vp);
 	vp->v_vnlock = NULL;
 	lockdestroy(&vp->v_lock);
 
+	VI_LOCK(vp);
 	if (VSHOULDFREE(vp))
 		vfree(vp);
 
@@ -2268,10 +2304,10 @@ vclean(vp, flags, td)
 	if (vp->v_pollinfo != NULL)
 		vn_pollgone(vp);
 	vp->v_tag = VT_NON;
-	vp->v_flag &= ~VXLOCK;
+	vp->v_iflag &= ~VI_XLOCK;
 	vp->v_vxproc = NULL;
-	if (vp->v_flag & VXWANT) {
-		vp->v_flag &= ~VXWANT;
+	if (vp->v_iflag & VI_XWANT) {
+		vp->v_iflag &= ~VI_XWANT;
 		wakeup(vp);
 	}
 }
@@ -2293,16 +2329,19 @@ vop_revoke(ap)
 	KASSERT((ap->a_flags & REVOKEALL) != 0, ("vop_revoke"));
 
 	vp = ap->a_vp;
+	VI_LOCK(vp);
 	/*
 	 * If a vgone (or vclean) is already in progress,
 	 * wait until it is done and return.
 	 */
-	if (vp->v_flag & VXLOCK) {
-		vp->v_flag |= VXWANT;
-		msleep(vp, &vp->v_interlock, PINOD | PDROP,
+	if (vp->v_iflag & VI_XLOCK) {
+		vp->v_iflag |= VI_XWANT;
+		msleep(vp, VI_MTX(vp), PINOD | PDROP,
 		    "vop_revokeall", 0);
+		VI_UNLOCK(vp);
 		return (0);
 	}
+	VI_UNLOCK(vp);
 	dev = vp->v_rdev;
 	for (;;) {
 		mtx_lock(&spechash_mtx);
@@ -2348,7 +2387,7 @@ vgone(vp)
 {
 	struct thread *td = curthread;	/* XXX */
 
-	mtx_lock(&vp->v_interlock);
+	VI_LOCK(vp);
 	vgonel(vp, td);
 }
 
@@ -2366,9 +2405,11 @@ vgonel(vp, td)
 	 * If a vgone (or vclean) is already in progress,
 	 * wait until it is done and return.
 	 */
-	if (vp->v_flag & VXLOCK) {
-		vp->v_flag |= VXWANT;
-		msleep(vp, &vp->v_interlock, PINOD | PDROP, "vgone", 0);
+	mtx_assert(VI_MTX(vp), MA_OWNED);
+	if (vp->v_iflag & VI_XLOCK) {
+		vp->v_iflag |= VI_XWANT;
+		VI_UNLOCK(vp);
+		tsleep(vp, PINOD | PDROP, "vgone", 0);
 		return;
 	}
 
@@ -2376,7 +2417,7 @@ vgonel(vp, td)
 	 * Clean out the filesystem specific data.
 	 */
 	vclean(vp, DOCLOSE, td);
-	mtx_lock(&vp->v_interlock);
+	VI_UNLOCK(vp);
 
 	/*
 	 * Delete from old mount point vnode list, if on one.
@@ -2405,21 +2446,23 @@ vgonel(vp, td)
 	 * incremented first, vgone would (incorrectly) try to
 	 * close the previous instance of the underlying object.
 	 */
-	if (vp->v_usecount == 0 && !(vp->v_flag & VDOOMED)) {
+	VI_LOCK(vp);
+	if (vp->v_usecount == 0 && !(vp->v_iflag & VI_DOOMED)) {
 		s = splbio();
 		mtx_lock(&vnode_free_list_mtx);
-		if (vp->v_flag & VFREE)
+		if (vp->v_iflag & VI_FREE) {
 			TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
-		else
+		} else {
+			vp->v_iflag |= VI_FREE;
 			freevnodes++;
-		vp->v_flag |= VFREE;
+		}
 		TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist);
 		mtx_unlock(&vnode_free_list_mtx);
 		splx(s);
 	}
 
 	vp->v_type = VBAD;
-	mtx_unlock(&vp->v_interlock);
+	VI_UNLOCK(vp);
 }
 
 /*
@@ -2499,24 +2542,24 @@ vprint(label, vp)
 	    typename[vp->v_type], vp->v_usecount, vp->v_writecount,
 	    vp->v_holdcnt);
 	buf[0] = '\0';
-	if (vp->v_flag & VROOT)
-		strcat(buf, "|VROOT");
-	if (vp->v_flag & VTEXT)
-		strcat(buf, "|VTEXT");
-	if (vp->v_flag & VSYSTEM)
-		strcat(buf, "|VSYSTEM");
-	if (vp->v_flag & VXLOCK)
-		strcat(buf, "|VXLOCK");
-	if (vp->v_flag & VXWANT)
-		strcat(buf, "|VXWANT");
-	if (vp->v_flag & VBWAIT)
-		strcat(buf, "|VBWAIT");
-	if (vp->v_flag & VDOOMED)
-		strcat(buf, "|VDOOMED");
-	if (vp->v_flag & VFREE)
-		strcat(buf, "|VFREE");
-	if (vp->v_flag & VOBJBUF)
-		strcat(buf, "|VOBJBUF");
+	if (vp->v_vflag & VV_ROOT)
+		strcat(buf, "|VV_ROOT");
+	if (vp->v_vflag & VV_TEXT)
+		strcat(buf, "|VV_TEXT");
+	if (vp->v_vflag & VV_SYSTEM)
+		strcat(buf, "|VV_SYSTEM");
+	if (vp->v_iflag & VI_XLOCK)
+		strcat(buf, "|VI_XLOCK");
+	if (vp->v_iflag & VI_XWANT)
+		strcat(buf, "|VI_XWANT");
+	if (vp->v_iflag & VI_BWAIT)
+		strcat(buf, "|VI_BWAIT");
+	if (vp->v_iflag & VI_DOOMED)
+		strcat(buf, "|VI_DOOMED");
+	if (vp->v_iflag & VI_FREE)
+		strcat(buf, "|VI_FREE");
+	if (vp->v_vflag & VV_OBJBUF)
+		strcat(buf, "|VV_OBJBUF");
 	if (buf[0] != '\0')
 		printf(" flags (%s)", &buf[1]);
 	if (vp->v_data == NULL) {
@@ -2673,7 +2716,6 @@ sysctl_vnode(SYSCTL_HANDLER_ARGS)
 			xvn[n].xv_size = sizeof *xvn;
 			xvn[n].xv_vnode = vp;
 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field
-			XV_COPY(flag);
 			XV_COPY(usecount);
 			XV_COPY(writecount);
 			XV_COPY(holdcnt);
@@ -2682,6 +2724,8 @@ sysctl_vnode(SYSCTL_HANDLER_ARGS)
 			XV_COPY(numoutput);
 			XV_COPY(type);
 #undef XV_COPY
+			xvn[n].xv_flag = vp->v_vflag;
+
 			switch (vp->v_type) {
 			case VREG:
 			case VDIR:
@@ -2801,13 +2845,14 @@ loop:
 		}
 		nvp = TAILQ_NEXT(vp, v_nmntvnodes);
 
-		if (vp->v_flag & VXLOCK)	/* XXX: what if MNT_WAIT? */
+		mp_fixme("What locks do we need here?");
+		if (vp->v_iflag & VI_XLOCK)	/* XXX: what if MNT_WAIT? */
 			continue;
 
-		if (vp->v_flag & VNOSYNC)	/* unlinked, skip it */
+		if (vp->v_vflag & VV_NOSYNC)	/* unlinked, skip it */
 			continue;
 
-		if ((vp->v_flag & VOBJDIRTY) &&
+		if ((vp->v_iflag & VI_OBJDIRTY) &&
 		    (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) {
 			mtx_unlock(&mntvnode_mtx);
 			if (!vget(vp,
@@ -2857,18 +2902,19 @@ vfree(vp)
 {
 	int s;
 
+	mtx_assert(VI_MTX(vp), MA_OWNED);
 	s = splbio();
 	mtx_lock(&vnode_free_list_mtx);
-	KASSERT((vp->v_flag & VFREE) == 0, ("vnode already free"));
-	if (vp->v_flag & VAGE) {
+	KASSERT((vp->v_iflag & VI_FREE) == 0, ("vnode already free"));
+	if (vp->v_iflag & VI_AGE) {
 		TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist);
 	} else {
 		TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
 	}
 	freevnodes++;
 	mtx_unlock(&vnode_free_list_mtx);
-	vp->v_flag &= ~VAGE;
-	vp->v_flag |= VFREE;
+	vp->v_iflag &= ~VI_AGE;
+	vp->v_iflag |= VI_FREE;
 	splx(s);
 }
 
@@ -2882,12 +2928,13 @@ vbusy(vp)
 	int s;
 
 	s = splbio();
+	mtx_assert(VI_MTX(vp), MA_OWNED);
 	mtx_lock(&vnode_free_list_mtx);
-	KASSERT((vp->v_flag & VFREE) != 0, ("vnode not free"));
+	KASSERT((vp->v_iflag & VI_FREE) != 0, ("vnode not free"));
 	TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
 	freevnodes--;
 	mtx_unlock(&vnode_free_list_mtx);
-	vp->v_flag &= ~(VFREE|VAGE);
+	vp->v_iflag &= ~(VI_FREE|VI_AGE);
 	splx(s);
 }
 
@@ -3044,7 +3091,9 @@ vfs_allocate_syncvnode(mp)
 		}
 		next = start;
 	}
+	VI_LOCK(vp);
 	vn_syncer_add_to_worklist(vp, syncdelay > 0 ? next % syncdelay : 0);
+	VI_UNLOCK(vp);
 	mp->mnt_syncer = vp;
 	return (0);
 }
@@ -3075,7 +3124,9 @@ sync_fsync(ap)
 	/*
 	 * Move ourselves to the back of the sync list.
 	 */
+	VI_LOCK(syncvp);
 	vn_syncer_add_to_worklist(syncvp, syncdelay);
+	VI_UNLOCK(syncvp);
 
 	/*
 	 * Walk the list of vnodes pushing all that are dirty and
@@ -3133,10 +3184,12 @@ sync_reclaim(ap)
 
 	s = splbio();
 	vp->v_mount->mnt_syncer = NULL;
-	if (vp->v_flag & VONWORKLST) {
+	VI_LOCK(vp);
+	if (vp->v_iflag & VI_ONWORKLST) {
 		LIST_REMOVE(vp, v_synclist);
-		vp->v_flag &= ~VONWORKLST;
+		vp->v_iflag &= ~VI_ONWORKLST;
 	}
+	VI_UNLOCK(vp);
 	splx(s);
 
 	return (0);
diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c
index f02f62f..197829b 100644
--- a/sys/kern/vfs_syscalls.c
+++ b/sys/kern/vfs_syscalls.c
@@ -1155,7 +1155,8 @@ restart:
 		 *
 		 * XXX: can this only be a VDIR case?
 		 */
-		if (vp->v_flag & VROOT)
+		mp_fixme("Accessing vflags w/o the vn lock.");
+		if (vp->v_vflag & VV_ROOT)
 			error = EBUSY;
 	}
 	if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
@@ -2778,7 +2779,7 @@ restart:
 	/*
 	 * The root of a mounted filesystem cannot be deleted.
 	 */
-	if (vp->v_flag & VROOT) {
+	if (vp->v_vflag & VV_ROOT) {
 		error = EBUSY;
 		goto out;
 	}
@@ -2939,7 +2940,8 @@ unionread:
 				return (error);
 			}
 		}
-		if ((vp->v_flag & VROOT) &&
+		mp_fixme("Accessing vflags w/o vn lock.");
+		if ((vp->v_vflag & VV_ROOT) &&
 		    (vp->v_mount->mnt_flag & MNT_UNION)) {
 			struct vnode *tvp = vp;
 			vp = vp->v_mount->mnt_vnodecovered;
@@ -3030,7 +3032,8 @@ unionread:
 				return (error);
 			}
 		}
-		if ((vp->v_flag & VROOT) &&
+		mp_fixme("Accessing vflag without vn lock.");
+		if ((vp->v_vflag & VV_ROOT) &&
 		    (vp->v_mount->mnt_flag & MNT_UNION)) {
 			struct vnode *tvp = vp;
 			vp = vp->v_mount->mnt_vnodecovered;
diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c
index 9a4ed2b..09dcf58 100644
--- a/sys/kern/vfs_vnops.c
+++ b/sys/kern/vfs_vnops.c
@@ -279,13 +279,15 @@ vn_writechk(vp)
 	register struct vnode *vp;
 {
 
+	ASSERT_VOP_LOCKED(vp, "vn_writechk");
 	/*
 	 * If there's shared text associated with
 	 * the vnode, try to free it up once.  If
 	 * we fail, we can't allow writing.
 	 */
-	if (vp->v_flag & VTEXT)
+	if (vp->v_vflag & VV_TEXT)
 		return (ETXTBSY);
+
 	return (0);
 }
 
@@ -818,10 +820,10 @@ debug_vn_lock(vp, flags, td, filename, line)
 
 	do {
 		if ((flags & LK_INTERLOCK) == 0)
-			mtx_lock(&vp->v_interlock);
-		if ((vp->v_flag & VXLOCK) && vp->v_vxproc != curthread) {
-			vp->v_flag |= VXWANT;
-			msleep(vp, &vp->v_interlock, PINOD | PDROP,
+			VI_LOCK(vp);
+		if ((vp->v_iflag & VI_XLOCK) && vp->v_vxproc != curthread) {
+			vp->v_iflag |= VI_XWANT;
+			msleep(vp, VI_MTX(vp), PINOD | PDROP,
 			    "vn_lock", 0);
 			error = ENOENT;
 		} else {
diff --git a/sys/nfsclient/nfs_bio.c b/sys/nfsclient/nfs_bio.c
index 685c6d1..d8243ae 100644
--- a/sys/nfsclient/nfs_bio.c
+++ b/sys/nfsclient/nfs_bio.c
@@ -1063,9 +1063,13 @@ nfs_vinvalbuf(struct vnode *vp, int flags, struct ucred *cred,
 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
 	int error = 0, slpflag, slptimeo;
 
-	if (vp->v_flag & VXLOCK) {
+	VI_LOCK(vp);
+	if (vp->v_iflag & VI_XLOCK) {
+		/* XXX Should we wait here? */
+		VI_UNLOCK(vp);
 		return (0);
 	}
+	VI_UNLOCK(vp);
 
 	if ((nmp->nm_flag & NFSMNT_INT) == 0)
 		intrflg = 0;
@@ -1340,7 +1344,8 @@ nfs_doio(struct buf *bp, struct ucred *cr, struct thread *td)
 			uiop->uio_resid = 0;
 		    }
 		}
-		if (p && (vp->v_flag & VTEXT) &&
+		mp_fixme("Accessing VV_TEXT without a lock.");
+		if (p && (vp->v_vflag & VV_TEXT) &&
 			(np->n_mtime != np->n_vattr.va_mtime.tv_sec)) {
 			uprintf("Process killed due to text file modification\n");
 			PROC_LOCK(p);
diff --git a/sys/nfsclient/nfs_vfsops.c b/sys/nfsclient/nfs_vfsops.c
index 45ad218..4ac930e 100644
--- a/sys/nfsclient/nfs_vfsops.c
+++ b/sys/nfsclient/nfs_vfsops.c
@@ -505,7 +505,8 @@ nfs_mountroot(struct mount *mp, struct thread *td)
 		 * hack it to a regular file.
 		 */
 		vp->v_type = VREG;
-		vp->v_flag = 0;
+		vp->v_vflag = 0;
+		vp->v_iflag = 0;
 		VREF(vp);
 		swaponvp(td, vp, NODEV, nd->swap_nblks);
 	}
@@ -951,7 +952,7 @@ nfs_root(struct mount *mp, struct vnode **vpp)
 	vp = NFSTOV(np);
 	if (vp->v_type == VNON)
 	    vp->v_type = VDIR;
-	vp->v_flag = VROOT;
+	vp->v_vflag |= VV_ROOT;
 	*vpp = vp;
 	return (0);
 }
diff --git a/sys/nfsclient/nfs_vnops.c b/sys/nfsclient/nfs_vnops.c
index a2aa645..37b9264 100644
--- a/sys/nfsclient/nfs_vnops.c
+++ b/sys/nfsclient/nfs_vnops.c
@@ -2807,9 +2807,10 @@ loop:
 		goto again;
 	}
 	if (waitfor == MNT_WAIT) {
+		VI_LOCK(vp);
 		while (vp->v_numoutput) {
-			vp->v_flag |= VBWAIT;
-			error = tsleep((caddr_t)&vp->v_numoutput,
+			vp->v_iflag |= VI_BWAIT;
+			error = msleep((caddr_t)&vp->v_numoutput, VI_MTX(vp),
 				slpflag | (PRIBIO + 1), "nfsfsync", slptimeo);
 			if (error) {
 			    if (nfs_sigintr(nmp, NULL, td)) {
@@ -2822,6 +2823,7 @@ loop:
 			    }
 			}
 		}
+		VI_UNLOCK(vp);
 		if (!TAILQ_EMPTY(&vp->v_dirtyblkhd) && commit) {
 			goto loop;
 		}
diff --git a/sys/nfsserver/nfs_serv.c b/sys/nfsserver/nfs_serv.c
index 47f9c1f..edf7575 100644
--- a/sys/nfsserver/nfs_serv.c
+++ b/sys/nfsserver/nfs_serv.c
@@ -2103,7 +2103,7 @@ nfsrv_remove(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
 		/*
 		 * The root of a mounted filesystem cannot be deleted.
 		 */
-		if (nd.ni_vp->v_flag & VROOT) {
+		if (nd.ni_vp->v_vflag & VV_ROOT) {
 			error = EBUSY;
 			goto out;
 		}
@@ -2891,7 +2891,7 @@ nfsrv_rmdir(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
 	/*
 	 * The root of a mounted filesystem cannot be deleted.
 	 */
-	if (vp->v_flag & VROOT)
+	if (vp->v_vflag & VV_ROOT)
 		error = EBUSY;
 out:
 	/*
@@ -4052,7 +4052,7 @@ nfsrv_access(struct vnode *vp, int flags, struct ucred *cred, int rdonly,
 		 * If there's shared text associated with
 		 * the inode, we can't allow writing.
 		 */
-		if (vp->v_flag & VTEXT)
+		if (vp->v_vflag & VV_TEXT)
 			return (ETXTBSY);
 	}
 	error = VOP_GETATTR(vp, &vattr, cred, td);
diff --git a/sys/security/lomac/kernel_interface.c b/sys/security/lomac/kernel_interface.c
index adaff99..c4a0c04 100644
--- a/sys/security/lomac/kernel_interface.c
+++ b/sys/security/lomac/kernel_interface.c
@@ -374,7 +374,7 @@ set_object_lattr(lomac_object_t *obj, lattr_t lattr) {
 		vp = obj->lo_object.vnode;
 		KASSERT(!VISLOMAC(vp), ("is a LOMACFS vnode"));
 		VI_LOCK(vp);
-		vp->v_flag = (vp->v_flag & ~(UV_LEVEL_MASK | UV_ATTR_MASK)) |
+		vp->v_iflag = (vp->v_iflag & ~(UV_LEVEL_MASK | UV_ATTR_MASK)) |
 		    level2uvnodebits(lattr.level) |
 		    attr2uvnodebits(lattr.flags);
 		VI_UNLOCK(vp);
@@ -453,8 +453,8 @@ get_object_lattr(const lomac_object_t *obj, lattr_t *lattr) {
 		vp = obj->lo_object.vnode;
 		KASSERT(!VISLOMAC(vp), ("is a LOMACFS vnode"));
 		VI_LOCK(vp);
-		lattr->level = uvnodebits2level(vp->v_flag);
-		lattr->flags = uvnodebits2attr(vp->v_flag);
+		lattr->level = uvnodebits2level(vp->v_iflag);
+		lattr->flags = uvnodebits2attr(vp->v_iflag);
 		VI_UNLOCK(vp);
 		break;
 	case LO_TYPE_VM_OBJECT:
diff --git a/sys/security/lomac/kernel_util.c b/sys/security/lomac/kernel_util.c
index 4a4999d..91e488e 100644
--- a/sys/security/lomac/kernel_util.c
+++ b/sys/security/lomac/kernel_util.c
@@ -400,7 +400,7 @@ unmount(td, uap)
 	/*
 	 * Must be the root of the filesystem
 	 */
-	if ((vp->v_flag & VROOT) == 0) {
+	if ((vp->v_vflag & VV_ROOT) == 0) {
 		vput(vp);
 		return (EINVAL);
 	}
@@ -542,7 +542,8 @@ lomac_getcwd(
 		struct dirent *dp;
 		int direof;
 
-		if (vp->v_flag & VROOT) {
+		ASSERT_VOP_LOCKED(vp, "lomac_getcwd");
+		if (vp->v_vflag & VV_ROOT) {
 			if (vp->v_mount == NULL)	/* forced unmount */
 				return (EBADF);
 			dvp = vp->v_mount->mnt_vnodecovered;
diff --git a/sys/security/lomac/lomacfs_subr.c b/sys/security/lomac/lomacfs_subr.c
index 1bd559d..10519da 100644
--- a/sys/security/lomac/lomacfs_subr.c
+++ b/sys/security/lomac/lomacfs_subr.c
@@ -112,7 +112,7 @@ lomacfs_node_alloc(struct mount *mp, struct componentname *cnp,
 	if (error)
 		panic("lomacfs_node_alloc: can't lock new vnode\n");
 	if (cnp == NULL)
-		vp->v_flag |= VROOT;
+		vp->v_vflag |= VV_ROOT;
 	else if (cnp->cn_flags & MAKEENTRY)
 		cache_enter(dvp, vp, cnp);
 
diff --git a/sys/security/lomac/lomacfs_vfsops.c b/sys/security/lomac/lomacfs_vfsops.c
index 95b99e8..4df2484 100644
--- a/sys/security/lomac/lomacfs_vfsops.c
+++ b/sys/security/lomac/lomacfs_vfsops.c
@@ -121,11 +121,10 @@ lomacfs_unmount(struct mount *mp, int mntflags, struct thread *td) {
 	if (mntflags & MNT_FORCE)
 		flags |= FORCECLOSE;
 
-	if (VFSTOLOMAC(mp)->lm_flags & LM_TOOKROOT) {
-		mtx_lock(&crootvp->v_interlock);
-		crootvp->v_flag |= VROOT;
-		mtx_unlock(&crootvp->v_interlock);
-	}
+	ASSERT_VOP_LOCKED(crootvp, "lomacfs_unmount");
+
+	if (VFSTOLOMAC(mp)->lm_flags & LM_TOOKROOT)
+		crootvp->v_vflag |= VV_ROOT;
 
 	error = vflush(mp, 1, flags);	/* have an extra root ref */
 	if (error)
@@ -167,9 +166,10 @@ lomacfs_root(struct mount *mp, struct vnode **vpp) {
 		 * that the mounted-on directory isn't a root vnode if I
 		 * want things like __getcwd() to just fail and not crash.
 		 */
+		mp_fixme("This code needs the vn lock, not interlock.");
 		mtx_lock(&crootvp->v_interlock);
-		if (crootvp->v_flag & VROOT && crootvp == rootvnode) {
-			crootvp->v_flag &= ~VROOT;
+		if (crootvp->v_vflag & VV_ROOT && crootvp == rootvnode) {
+			crootvp->v_vflag &= ~VV_ROOT;
 			VFSTOLOMAC(mp)->lm_flags |= LM_TOOKROOT;
 		}
 		mtx_unlock(&crootvp->v_interlock);
diff --git a/sys/security/lomac/lomacfs_vnops.c b/sys/security/lomac/lomacfs_vnops.c
index 28e9a26..9d98e69 100644
--- a/sys/security/lomac/lomacfs_vnops.c
+++ b/sys/security/lomac/lomacfs_vnops.c
@@ -868,7 +868,7 @@ lomacfs_createvobject(
 	error = VOP_CREATEVOBJECT(lowervp, ap->a_cred, ap->a_td);
 	if (error)
 		return (error);
-	vp->v_flag |= VOBJBUF;
+	vp->v_vflag |= VV_OBJBUF;
 	return (error);
 }
 
@@ -884,7 +884,7 @@ lomacfs_destroyvobject(
 ) {
 	struct vnode *vp = ap->a_vp;
 
-	vp->v_flag &= ~VOBJBUF;
+	vp->v_vflag &= ~VV_OBJBUF;
 	return (0);
 }
 
diff --git a/sys/security/mac/mac_framework.c b/sys/security/mac/mac_framework.c
index 43c03cc..6544f01 100644
--- a/sys/security/mac/mac_framework.c
+++ b/sys/security/mac/mac_framework.c
@@ -978,8 +978,9 @@ mac_update_vnode_from_mount(struct vnode *vp, struct mount *mp)
 	MAC_PERFORM(update_vnode_from_mount, vp, &vp->v_label, mp,
 	    &mp->mnt_fslabel);
 
+	ASSERT_VOP_LOCKED(vp, "mac_update_vnode_from_mount");
 	if (mac_cache_fslabel_in_vnode)
-		vp->v_flag |= VCACHEDLABEL;
+		vp->v_vflag |= VV_CACHEDLABEL;
 }
 
 /*
@@ -1031,7 +1032,7 @@ vop_stdrefreshlabel_ea(struct vop_refreshlabel_args *ap)
 	if (error == 0)
 		error = mac_update_vnode_from_externalized(vp, &extmac);
 	if (error == 0)
-		vp->v_flag |= VCACHEDLABEL;
+		vp->v_vflag |= VV_CACHEDLABEL;
 	else {
 		struct vattr va;
 
@@ -1084,7 +1085,7 @@ vn_refreshlabel(struct vnode *vp, struct ucred *cred)
 		return (EBADF);
 	}
 
-	if (vp->v_flag & VCACHEDLABEL) {
+	if (vp->v_vflag & VV_CACHEDLABEL) {
 		mac_vnode_label_cache_hits++;
 		return (0);
 	} else
@@ -1124,6 +1125,7 @@ vop_stdcreatevnode_ea(struct vnode *dvp, struct vnode *tvp, struct ucred *cred)
 	struct mac extmac;
 	int error;
 
+	ASSERT_VOP_LOCKED(tvp, "vop_stdcreatevnode_ea");
 	if ((dvp->v_mount->mnt_flag & MNT_MULTILABEL) == 0) {
 		mac_update_vnode_from_mount(tvp, tvp->v_mount);
 	} else {
@@ -1156,7 +1158,7 @@ vop_stdcreatevnode_ea(struct vnode *dvp, struct vnode *tvp, struct ucred *cred)
 		    FREEBSD_MAC_EXTATTR_NAMESPACE, FREEBSD_MAC_EXTATTR_NAME,
 		    sizeof(extmac), (char *)&extmac, curthread);
 		if (error == 0)
-			tvp->v_flag |= VCACHEDLABEL;
+			tvp->v_vflag |= VV_CACHEDLABEL;
 		else {
 #if 0
 			/*
@@ -2771,7 +2773,7 @@ vop_stdsetlabel_ea(struct vop_setlabel_args *ap)
 
 	mac_relabel_vnode(ap->a_cred, vp, intlabel);
 
-	vp->v_flag |= VCACHEDLABEL;
+	vp->v_vflag |= VV_CACHEDLABEL;
 
 	return (0);
 }
diff --git a/sys/security/mac/mac_internal.h b/sys/security/mac/mac_internal.h
index 43c03cc..6544f01 100644
--- a/sys/security/mac/mac_internal.h
+++ b/sys/security/mac/mac_internal.h
@@ -978,8 +978,9 @@ mac_update_vnode_from_mount(struct vnode *vp, struct mount *mp)
 	MAC_PERFORM(update_vnode_from_mount, vp, &vp->v_label, mp,
 	    &mp->mnt_fslabel);
 
+	ASSERT_VOP_LOCKED(vp, "mac_update_vnode_from_mount");
 	if (mac_cache_fslabel_in_vnode)
-		vp->v_flag |= VCACHEDLABEL;
+		vp->v_vflag |= VV_CACHEDLABEL;
 }
 
 /*
@@ -1031,7 +1032,7 @@ vop_stdrefreshlabel_ea(struct vop_refreshlabel_args *ap)
 	if (error == 0)
 		error = mac_update_vnode_from_externalized(vp, &extmac);
 	if (error == 0)
-		vp->v_flag |= VCACHEDLABEL;
+		vp->v_vflag |= VV_CACHEDLABEL;
 	else {
 		struct vattr va;
 
@@ -1084,7 +1085,7 @@ vn_refreshlabel(struct vnode *vp, struct ucred *cred)
 		return (EBADF);
 	}
 
-	if (vp->v_flag & VCACHEDLABEL) {
+	if (vp->v_vflag & VV_CACHEDLABEL) {
 		mac_vnode_label_cache_hits++;
 		return (0);
 	} else
@@ -1124,6 +1125,7 @@ vop_stdcreatevnode_ea(struct vnode *dvp, struct vnode *tvp, struct ucred *cred)
 	struct mac extmac;
 	int error;
 
+	ASSERT_VOP_LOCKED(tvp, "vop_stdcreatevnode_ea");
 	if ((dvp->v_mount->mnt_flag & MNT_MULTILABEL) == 0) {
 		mac_update_vnode_from_mount(tvp, tvp->v_mount);
 	} else {
@@ -1156,7 +1158,7 @@ vop_stdcreatevnode_ea(struct vnode *dvp, struct vnode *tvp, struct ucred *cred)
 		    FREEBSD_MAC_EXTATTR_NAMESPACE, FREEBSD_MAC_EXTATTR_NAME,
 		    sizeof(extmac), (char *)&extmac, curthread);
 		if (error == 0)
-			tvp->v_flag |= VCACHEDLABEL;
+			tvp->v_vflag |= VV_CACHEDLABEL;
 		else {
 #if 0
 			/*
@@ -2771,7 +2773,7 @@ vop_stdsetlabel_ea(struct vop_setlabel_args *ap)
 
 	mac_relabel_vnode(ap->a_cred, vp, intlabel);
 
-	vp->v_flag |= VCACHEDLABEL;
+	vp->v_vflag |= VV_CACHEDLABEL;
 
 	return (0);
 }
diff --git a/sys/security/mac/mac_net.c b/sys/security/mac/mac_net.c
index 43c03cc..6544f01 100644
--- a/sys/security/mac/mac_net.c
+++ b/sys/security/mac/mac_net.c
@@ -978,8 +978,9 @@ mac_update_vnode_from_mount(struct vnode *vp, struct mount *mp)
 	MAC_PERFORM(update_vnode_from_mount, vp, &vp->v_label, mp,
 	    &mp->mnt_fslabel);
 
+	ASSERT_VOP_LOCKED(vp, "mac_update_vnode_from_mount");
 	if (mac_cache_fslabel_in_vnode)
-		vp->v_flag |= VCACHEDLABEL;
+		vp->v_vflag |= VV_CACHEDLABEL;
 }
 
 /*
@@ -1031,7 +1032,7 @@ vop_stdrefreshlabel_ea(struct vop_refreshlabel_args *ap)
 	if (error == 0)
 		error = mac_update_vnode_from_externalized(vp, &extmac);
 	if (error == 0)
-		vp->v_flag |= VCACHEDLABEL;
+		vp->v_vflag |= VV_CACHEDLABEL;
 	else {
 		struct vattr va;
 
@@ -1084,7 +1085,7 @@ vn_refreshlabel(struct vnode *vp, struct ucred *cred)
 		return (EBADF);
 	}
 
-	if (vp->v_flag & VCACHEDLABEL) {
+	if (vp->v_vflag & VV_CACHEDLABEL) {
 		mac_vnode_label_cache_hits++;
 		return (0);
 	} else
@@ -1124,6 +1125,7 @@ vop_stdcreatevnode_ea(struct vnode *dvp, struct vnode *tvp, struct ucred *cred)
 	struct mac extmac;
 	int error;
 
+	ASSERT_VOP_LOCKED(tvp, "vop_stdcreatevnode_ea");
 	if ((dvp->v_mount->mnt_flag & MNT_MULTILABEL) == 0) {
 		mac_update_vnode_from_mount(tvp, tvp->v_mount);
 	} else {
@@ -1156,7 +1158,7 @@ vop_stdcreatevnode_ea(struct vnode *dvp, struct vnode *tvp, struct ucred *cred)
 		    FREEBSD_MAC_EXTATTR_NAMESPACE, FREEBSD_MAC_EXTATTR_NAME,
 		    sizeof(extmac), (char *)&extmac, curthread);
 		if (error == 0)
-			tvp->v_flag |= VCACHEDLABEL;
+			tvp->v_vflag |= VV_CACHEDLABEL;
 		else {
 #if 0
 			/*
@@ -2771,7 +2773,7 @@ vop_stdsetlabel_ea(struct vop_setlabel_args *ap)
 
 	mac_relabel_vnode(ap->a_cred, vp, intlabel);
 
-	vp->v_flag |= VCACHEDLABEL;
+	vp->v_vflag |= VV_CACHEDLABEL;
 
 	return (0);
 }
diff --git a/sys/security/mac/mac_pipe.c b/sys/security/mac/mac_pipe.c
index 43c03cc..6544f01 100644
--- a/sys/security/mac/mac_pipe.c
+++ b/sys/security/mac/mac_pipe.c
@@ -978,8 +978,9 @@ mac_update_vnode_from_mount(struct vnode *vp, struct mount *mp)
 	MAC_PERFORM(update_vnode_from_mount, vp, &vp->v_label, mp,
 	    &mp->mnt_fslabel);
 
+	ASSERT_VOP_LOCKED(vp, "mac_update_vnode_from_mount");
 	if (mac_cache_fslabel_in_vnode)
-		vp->v_flag |= VCACHEDLABEL;
+		vp->v_vflag |= VV_CACHEDLABEL;
 }
 
 /*
@@ -1031,7 +1032,7 @@ vop_stdrefreshlabel_ea(struct vop_refreshlabel_args *ap)
 	if (error == 0)
 		error = mac_update_vnode_from_externalized(vp, &extmac);
 	if (error == 0)
-		vp->v_flag |= VCACHEDLABEL;
+		vp->v_vflag |= VV_CACHEDLABEL;
 	else {
 		struct vattr va;
 
@@ -1084,7 +1085,7 @@ vn_refreshlabel(struct vnode *vp, struct ucred *cred)
 		return (EBADF);
 	}
 
-	if (vp->v_flag & VCACHEDLABEL) {
+	if (vp->v_vflag & VV_CACHEDLABEL) {
 		mac_vnode_label_cache_hits++;
 		return (0);
 	} else
@@ -1124,6 +1125,7 @@ vop_stdcreatevnode_ea(struct vnode *dvp, struct vnode *tvp, struct ucred *cred)
 	struct mac extmac;
 	int error;
 
+	ASSERT_VOP_LOCKED(tvp, "vop_stdcreatevnode_ea");
 	if ((dvp->v_mount->mnt_flag & MNT_MULTILABEL) == 0) {
 		mac_update_vnode_from_mount(tvp, tvp->v_mount);
 	} else {
@@ -1156,7 +1158,7 @@ vop_stdcreatevnode_ea(struct vnode *dvp, struct vnode *tvp, struct ucred *cred)
 		    FREEBSD_MAC_EXTATTR_NAMESPACE, FREEBSD_MAC_EXTATTR_NAME,
 		    sizeof(extmac), (char *)&extmac, curthread);
 		if (error == 0)
-			tvp->v_flag |= VCACHEDLABEL;
+			tvp->v_vflag |= VV_CACHEDLABEL;
 		else {
 #if 0
 			/*
@@ -2771,7 +2773,7 @@ vop_stdsetlabel_ea(struct vop_setlabel_args *ap)
 
 	mac_relabel_vnode(ap->a_cred, vp, intlabel);
 
-	vp->v_flag |= VCACHEDLABEL;
+	vp->v_vflag |= VV_CACHEDLABEL;
 
 	return (0);
 }
diff --git a/sys/security/mac/mac_process.c b/sys/security/mac/mac_process.c
index 43c03cc..6544f01 100644
--- a/sys/security/mac/mac_process.c
+++ b/sys/security/mac/mac_process.c
@@ -978,8 +978,9 @@ mac_update_vnode_from_mount(struct vnode *vp, struct mount *mp)
 	MAC_PERFORM(update_vnode_from_mount, vp, &vp->v_label, mp,
 	    &mp->mnt_fslabel);
 
+	ASSERT_VOP_LOCKED(vp, "mac_update_vnode_from_mount");
 	if (mac_cache_fslabel_in_vnode)
-		vp->v_flag |= VCACHEDLABEL;
+		vp->v_vflag |= VV_CACHEDLABEL;
 }
 
 /*
@@ -1031,7 +1032,7 @@ vop_stdrefreshlabel_ea(struct vop_refreshlabel_args *ap)
 	if (error == 0)
 		error = mac_update_vnode_from_externalized(vp, &extmac);
 	if (error == 0)
-		vp->v_flag |= VCACHEDLABEL;
+		vp->v_vflag |= VV_CACHEDLABEL;
 	else {
 		struct vattr va;
 
@@ -1084,7 +1085,7 @@ vn_refreshlabel(struct vnode *vp, struct ucred *cred)
 		return (EBADF);
 	}
 
-	if (vp->v_flag & VCACHEDLABEL) {
+	if (vp->v_vflag & VV_CACHEDLABEL) {
 		mac_vnode_label_cache_hits++;
 		return (0);
 	} else
@@ -1124,6 +1125,7 @@ vop_stdcreatevnode_ea(struct vnode *dvp, struct vnode *tvp, struct ucred *cred)
 	struct mac extmac;
 	int error;
 
+	ASSERT_VOP_LOCKED(tvp, "vop_stdcreatevnode_ea");
 	if ((dvp->v_mount->mnt_flag & MNT_MULTILABEL) == 0) {
 		mac_update_vnode_from_mount(tvp, tvp->v_mount);
 	} else {
@@ -1156,7 +1158,7 @@ vop_stdcreatevnode_ea(struct vnode *dvp, struct vnode *tvp, struct ucred *cred)
 		    FREEBSD_MAC_EXTATTR_NAMESPACE, FREEBSD_MAC_EXTATTR_NAME,
 		    sizeof(extmac), (char *)&extmac, curthread);
 		if (error == 0)
-			tvp->v_flag |= VCACHEDLABEL;
+			tvp->v_vflag |= VV_CACHEDLABEL;
 		else {
 #if 0
 			/*
@@ -2771,7 +2773,7 @@ vop_stdsetlabel_ea(struct vop_setlabel_args *ap)
 
 	mac_relabel_vnode(ap->a_cred, vp, intlabel);
 
-	vp->v_flag |= VCACHEDLABEL;
+	vp->v_vflag |= VV_CACHEDLABEL;
 
 	return (0);
 }
diff --git a/sys/security/mac/mac_syscalls.c b/sys/security/mac/mac_syscalls.c
index 43c03cc..6544f01 100644
--- a/sys/security/mac/mac_syscalls.c
+++ b/sys/security/mac/mac_syscalls.c
@@ -978,8 +978,9 @@ mac_update_vnode_from_mount(struct vnode *vp, struct mount *mp)
 	MAC_PERFORM(update_vnode_from_mount, vp, &vp->v_label, mp,
 	    &mp->mnt_fslabel);
 
+	ASSERT_VOP_LOCKED(vp, "mac_update_vnode_from_mount");
 	if (mac_cache_fslabel_in_vnode)
-		vp->v_flag |= VCACHEDLABEL;
+		vp->v_vflag |= VV_CACHEDLABEL;
 }
 
 /*
@@ -1031,7 +1032,7 @@ vop_stdrefreshlabel_ea(struct vop_refreshlabel_args *ap)
 	if (error == 0)
 		error = mac_update_vnode_from_externalized(vp, &extmac);
 	if (error == 0)
-		vp->v_flag |= VCACHEDLABEL;
+		vp->v_vflag |= VV_CACHEDLABEL;
 	else {
 		struct vattr va;
 
@@ -1084,7 +1085,7 @@ vn_refreshlabel(struct vnode *vp, struct ucred *cred)
 		return (EBADF);
 	}
 
-	if (vp->v_flag & VCACHEDLABEL) {
+	if (vp->v_vflag & VV_CACHEDLABEL) {
 		mac_vnode_label_cache_hits++;
 		return (0);
 	} else
@@ -1124,6 +1125,7 @@ vop_stdcreatevnode_ea(struct vnode *dvp, struct vnode *tvp, struct ucred *cred)
 	struct mac extmac;
 	int error;
 
+	ASSERT_VOP_LOCKED(tvp, "vop_stdcreatevnode_ea");
 	if ((dvp->v_mount->mnt_flag & MNT_MULTILABEL) == 0) {
 		mac_update_vnode_from_mount(tvp, tvp->v_mount);
 	} else {
@@ -1156,7 +1158,7 @@ vop_stdcreatevnode_ea(struct vnode *dvp, struct vnode *tvp, struct ucred *cred)
 		    FREEBSD_MAC_EXTATTR_NAMESPACE, FREEBSD_MAC_EXTATTR_NAME,
 		    sizeof(extmac), (char *)&extmac, curthread);
 		if (error == 0)
-			tvp->v_flag |= VCACHEDLABEL;
+			tvp->v_vflag |= VV_CACHEDLABEL;
 		else {
 #if 0
 			/*
@@ -2771,7 +2773,7 @@ vop_stdsetlabel_ea(struct vop_setlabel_args *ap)
 
 	mac_relabel_vnode(ap->a_cred, vp, intlabel);
 
-	vp->v_flag |= VCACHEDLABEL;
+	vp->v_vflag |= VV_CACHEDLABEL;
 
 	return (0);
 }
diff --git a/sys/security/mac/mac_system.c b/sys/security/mac/mac_system.c
index 43c03cc..6544f01 100644
--- a/sys/security/mac/mac_system.c
+++ b/sys/security/mac/mac_system.c
@@ -978,8 +978,9 @@ mac_update_vnode_from_mount(struct vnode *vp, struct mount *mp)
 	MAC_PERFORM(update_vnode_from_mount, vp, &vp->v_label, mp,
 	    &mp->mnt_fslabel);
 
+	ASSERT_VOP_LOCKED(vp, "mac_update_vnode_from_mount");
 	if (mac_cache_fslabel_in_vnode)
-		vp->v_flag |= VCACHEDLABEL;
+		vp->v_vflag |= VV_CACHEDLABEL;
 }
 
 /*
@@ -1031,7 +1032,7 @@ vop_stdrefreshlabel_ea(struct vop_refreshlabel_args *ap)
 	if (error == 0)
 		error = mac_update_vnode_from_externalized(vp, &extmac);
 	if (error == 0)
-		vp->v_flag |= VCACHEDLABEL;
+		vp->v_vflag |= VV_CACHEDLABEL;
 	else {
 		struct vattr va;
 
@@ -1084,7 +1085,7 @@ vn_refreshlabel(struct vnode *vp, struct ucred *cred)
 		return (EBADF);
 	}
 
-	if (vp->v_flag & VCACHEDLABEL) {
+	if (vp->v_vflag & VV_CACHEDLABEL) {
 		mac_vnode_label_cache_hits++;
 		return (0);
 	} else
@@ -1124,6 +1125,7 @@ vop_stdcreatevnode_ea(struct vnode *dvp, struct vnode *tvp, struct ucred *cred)
 	struct mac extmac;
 	int error;
 
+	ASSERT_VOP_LOCKED(tvp, "vop_stdcreatevnode_ea");
 	if ((dvp->v_mount->mnt_flag & MNT_MULTILABEL) == 0) {
 		mac_update_vnode_from_mount(tvp, tvp->v_mount);
 	} else {
@@ -1156,7 +1158,7 @@ vop_stdcreatevnode_ea(struct vnode *dvp, struct vnode *tvp, struct ucred *cred)
 		    FREEBSD_MAC_EXTATTR_NAMESPACE, FREEBSD_MAC_EXTATTR_NAME,
 		    sizeof(extmac), (char *)&extmac, curthread);
 		if (error == 0)
-			tvp->v_flag |= VCACHEDLABEL;
+			tvp->v_vflag |= VV_CACHEDLABEL;
 		else {
 #if 0
 			/*
@@ -2771,7 +2773,7 @@ vop_stdsetlabel_ea(struct vop_setlabel_args *ap)
 
 	mac_relabel_vnode(ap->a_cred, vp, intlabel);
 
-	vp->v_flag |= VCACHEDLABEL;
+	vp->v_vflag |= VV_CACHEDLABEL;
 
 	return (0);
 }
diff --git a/sys/security/mac/mac_vfs.c b/sys/security/mac/mac_vfs.c
index 43c03cc..6544f01 100644
--- a/sys/security/mac/mac_vfs.c
+++ b/sys/security/mac/mac_vfs.c
@@ -978,8 +978,9 @@ mac_update_vnode_from_mount(struct vnode *vp, struct mount *mp)
 	MAC_PERFORM(update_vnode_from_mount, vp, &vp->v_label, mp,
 	    &mp->mnt_fslabel);
 
+	ASSERT_VOP_LOCKED(vp, "mac_update_vnode_from_mount");
 	if (mac_cache_fslabel_in_vnode)
-		vp->v_flag |= VCACHEDLABEL;
+		vp->v_vflag |= VV_CACHEDLABEL;
 }
 
 /*
@@ -1031,7 +1032,7 @@ vop_stdrefreshlabel_ea(struct vop_refreshlabel_args *ap)
 	if (error == 0)
 		error = mac_update_vnode_from_externalized(vp, &extmac);
 	if (error == 0)
-		vp->v_flag |= VCACHEDLABEL;
+		vp->v_vflag |= VV_CACHEDLABEL;
 	else {
 		struct vattr va;
 
@@ -1084,7 +1085,7 @@ vn_refreshlabel(struct vnode *vp, struct ucred *cred)
 		return (EBADF);
 	}
 
-	if (vp->v_flag & VCACHEDLABEL) {
+	if (vp->v_vflag & VV_CACHEDLABEL) {
 		mac_vnode_label_cache_hits++;
 		return (0);
 	} else
@@ -1124,6 +1125,7 @@ vop_stdcreatevnode_ea(struct vnode *dvp, struct vnode *tvp, struct ucred *cred)
 	struct mac extmac;
 	int error;
 
+	ASSERT_VOP_LOCKED(tvp, "vop_stdcreatevnode_ea");
 	if ((dvp->v_mount->mnt_flag & MNT_MULTILABEL) == 0) {
 		mac_update_vnode_from_mount(tvp, tvp->v_mount);
 	} else {
@@ -1156,7 +1158,7 @@ vop_stdcreatevnode_ea(struct vnode *dvp, struct vnode *tvp, struct ucred *cred)
 		    FREEBSD_MAC_EXTATTR_NAMESPACE, FREEBSD_MAC_EXTATTR_NAME,
 		    sizeof(extmac), (char *)&extmac, curthread);
 		if (error == 0)
-			tvp->v_flag |= VCACHEDLABEL;
+			tvp->v_vflag |= VV_CACHEDLABEL;
 		else {
 #if 0
 			/*
@@ -2771,7 +2773,7 @@ vop_stdsetlabel_ea(struct vop_setlabel_args *ap)
 
 	mac_relabel_vnode(ap->a_cred, vp, intlabel);
 
-	vp->v_flag |= VCACHEDLABEL;
+	vp->v_vflag |= VV_CACHEDLABEL;
 
 	return (0);
 }
diff --git a/sys/sys/vnode.h b/sys/sys/vnode.h
index 5244836..db9c9e7 100644
--- a/sys/sys/vnode.h
+++ b/sys/sys/vnode.h
@@ -95,14 +95,20 @@ struct vpollinfo {
  * Reading or writing any of these items requires holding the appropriate lock.
  * v_freelist is locked by the global vnode_free_list mutex.
  * v_mntvnodes is locked by the global mntvnodes mutex.
- * v_flag, v_usecount, v_holdcount and v_writecount are
+ * v_iflag, v_usecount, v_holdcount and v_writecount are
  *    locked by the v_interlock mutex.
  * v_pollinfo is locked by the lock contained inside it.
+ * V vnode lock
+ * I inter lock
  */
 struct vnode {
-	u_long	v_flag;				/* vnode flags (see below) */
-	int	v_usecount;			/* reference count of users */
-	int	v_writecount;			/* reference count of writers */
+	struct	mtx v_interlock;		/* lock on usecount and flag */
+	u_long	v_iflag;			/* I vnode flags (see below) */
+	int	v_usecount;			/* I ref count of users */
+	int	v_writecount;			/* I ref count of writers */
+	long	v_numoutput;			/* I writes in progress */
+	struct thread *v_vxproc;		/* I thread owning VXLOCK */
+	u_long	v_vflag;			/* V vnode flags */
 	int	v_holdcnt;			/* page & buffer references */
 	u_long	v_id;				/* capability identifier */
 	struct	mount *v_mount;			/* ptr to vfs we are in */
@@ -114,7 +120,6 @@ struct vnode {
 	struct	buflists v_dirtyblkhd;		/* SORTED dirty blocklist */
 	struct buf	*v_dirtyblkroot;	/* dirty buf splay tree root */
 	LIST_ENTRY(vnode) v_synclist;		/* vnodes with dirty buffers */
-	long	v_numoutput;			/* num of writes in progress */
 	enum	vtype v_type;			/* vnode type */
 	union {
 		struct mount	*vu_mountedhere;/* ptr to mounted vfs (VDIR) */
@@ -130,7 +135,6 @@ struct vnode {
 	daddr_t	v_lasta;			/* last allocation (cluster) */
 	int	v_clen;				/* length of current cluster */
 	struct vm_object *v_object;		/* Place to store VM object */
-	struct	mtx v_interlock;		/* lock on usecount and flag */
 	struct	lock v_lock;			/* used if fs don't have one */
 	struct	lock *v_vnlock;			/* pointer to vnode lock */
 	enum	vtagtype v_tag;			/* type of underlying data */
@@ -140,7 +144,6 @@ struct vnode {
 	struct	vnode *v_dd;			/* .. vnode */
 	u_long	v_ddid;				/* .. capability identifier */
 	struct vpollinfo *v_pollinfo;
-	struct thread *v_vxproc;		/* thread owning VXLOCK */
 	struct label v_label;			/* MAC label for vnode */
 #ifdef	DEBUG_LOCKS
 	const char *filename;			/* Source file doing locking */
@@ -161,7 +164,7 @@ struct vnode {
 struct xvnode {
 	size_t	xv_size;			/* sizeof(struct xvnode) */
 	void	*xv_vnode;			/* address of real vnode */
-	u_long	xv_flag;			/* vnode flags */
+	u_long	xv_flag;			/* vnode vflags */
 	int	xv_usecount;			/* reference count of users */
 	int	xv_writecount;			/* reference count of writers */
 	int	xv_holdcnt;			/* page & buffer references */
@@ -200,27 +203,33 @@ struct xvnode {
 
 /*
  * Vnode flags.
- */
-#define	VROOT		0x00001	/* root of its filesystem */
-#define	VTEXT		0x00002	/* vnode is a pure text prototype */
-#define	VSYSTEM		0x00004	/* vnode being used by kernel */
-#define	VISTTY		0x00008	/* vnode represents a tty */
-#define	VXLOCK		0x00100	/* vnode is locked to change underlying type */
-#define	VXWANT		0x00200	/* thread is waiting for vnode */
-#define	VBWAIT		0x00400	/* waiting for output to complete */
-#define	VNOSYNC		0x01000	/* unlinked, stop syncing */
-/* open for business    0x01000 */
-#define	VOBJBUF		0x02000	/* Allocate buffers in VM object */
-#define	VCOPYONWRITE    0x04000 /* vnode is doing copy-on-write */
-#define	VAGE		0x08000	/* Insert vnode at head of free list */
-#define	VOLOCK		0x10000	/* vnode is locked waiting for an object */
-#define	VOWANT		0x20000	/* a thread is waiting for VOLOCK */
-#define	VDOOMED		0x40000	/* This vnode is being recycled */
-#define	VFREE		0x80000	/* This vnode is on the freelist */
-#define	VCACHEDLABEL	0x100000 /* Vnode has valid cached MAC label */
-#define	VONWORKLST	0x200000 /* On syncer work-list */
-#define	VMOUNT		0x400000 /* Mount in progress */
-#define	VOBJDIRTY	0x800000 /* object might be dirty */
+ *	VI flags are protected by interlock and live in v_iflag
+ *	VV flags are protected by the vnode lock and live in v_vflag
+ */
+#define	VI_XLOCK	0x0001	/* vnode is locked to change vtype */
+#define	VI_XWANT	0x0002	/* thread is waiting for vnode */
+#define	VI_BWAIT	0x0004	/* waiting for output to complete */
+#define	VI_OLOCK	0x0008	/* vnode is locked waiting for an object */
+#define	VI_OWANT	0x0010	/* a thread is waiting for VOLOCK */
+#define	VI_MOUNT	0x0020	/* Mount in progress */
+#define	VI_AGE		0x0040	/* Insert vnode at head of free list */
+#define	VI_DOOMED	0x0080	/* This vnode is being recycled */
+#define	VI_FREE		0x0100	/* This vnode is on the freelist */
+#define	VI_OBJDIRTY	0x0400	/* object might be dirty */
+/*
+ * XXX VI_ONWORKLST could be replaced with a check for NULL list elements
+ * in v_synclist.
+ */
+#define	VI_ONWORKLST	0x0200	/* On syncer work-list */
+
+#define	VV_ROOT		0x0001	/* root of its filesystem */
+#define	VV_ISTTY	0x0002	/* vnode represents a tty */
+#define	VV_NOSYNC	0x0004	/* unlinked, stop syncing */
+#define	VV_OBJBUF	0x0008	/* Allocate buffers in VM object */
+#define	VV_CACHEDLABEL	0x0010	/* Vnode has valid cached MAC label */
+#define	VV_TEXT		0x0020	/* vnode is a pure text prototype */
+#define	VV_COPYONWRITE	0x0040	/* vnode is doing copy-on-write */
+#define	VV_SYSTEM	0x0080	/* vnode being used by kernel */
 
 /*
  * Vnode attributes.  A field value of VNOVAL represents a field whose value
@@ -361,23 +370,27 @@ extern	int vfs_ioopt;
 
 extern void	(*lease_updatetime)(int deltat);
 
+/* Requires interlock */
 #define	VSHOULDFREE(vp)	\
-	(!((vp)->v_flag & (VFREE|VDOOMED)) && \
+	(!((vp)->v_iflag & (VI_FREE|VI_DOOMED)) && \
 	 !(vp)->v_holdcnt && !(vp)->v_usecount && \
 	 (!(vp)->v_object || \
 	  !((vp)->v_object->ref_count || (vp)->v_object->resident_page_count)))
 
+/* Requires interlock */
 #define VMIGHTFREE(vp) \
-	(!((vp)->v_flag & (VFREE|VDOOMED|VXLOCK)) &&	\
+	(!((vp)->v_iflag & (VI_FREE|VI_DOOMED|VI_XLOCK)) &&	\
 	 LIST_EMPTY(&(vp)->v_cache_src) && !(vp)->v_usecount)
 
+/* Requires interlock */
 #define	VSHOULDBUSY(vp)	\
-	(((vp)->v_flag & VFREE) && \
+	(((vp)->v_iflag & VI_FREE) && \
 	 ((vp)->v_holdcnt || (vp)->v_usecount))
 
 #define	VI_LOCK(vp)	mtx_lock(&(vp)->v_interlock)
 #define	VI_TRYLOCK(vp)	mtx_trylock(&(vp)->v_interlock)
 #define	VI_UNLOCK(vp)	mtx_unlock(&(vp)->v_interlock)
+#define	VI_MTX(vp)	(&(vp)->v_interlock)
 
 #endif /* _KERNEL */
 
diff --git a/sys/ufs/ffs/ffs_alloc.c b/sys/ufs/ffs/ffs_alloc.c
index 7888d8c..28b09cc 100644
--- a/sys/ufs/ffs/ffs_alloc.c
+++ b/sys/ufs/ffs/ffs_alloc.c
@@ -928,7 +928,8 @@ ffs_dirpref(pip)
 	/*
 	 * Force allocation in another cg if creating a first level dir.
 	 */
-	if (ITOV(pip)->v_flag & VROOT) {
+	ASSERT_VOP_LOCKED(ITOV(pip), "ffs_dirpref");
+	if (ITOV(pip)->v_vflag & VV_ROOT) {
 		prefcg = arc4random() % fs->fs_ncg;
 		mincg = prefcg;
 		minndir = fs->fs_ipg;
@@ -1697,7 +1698,8 @@ ffs_blkfree(fs, devvp, bno, size, inum)
 		/* devvp is a normal disk device */
 		dev = devvp->v_rdev;
 		cgblkno = fsbtodb(fs, cgtod(fs, cg));
-		if ((devvp->v_flag & VCOPYONWRITE) &&
+		ASSERT_VOP_LOCKED(devvp, "ffs_blkfree");
+		if ((devvp->v_vflag & VV_COPYONWRITE) &&
 		    ffs_snapblkfree(fs, devvp, bno, size, inum))
 			return;
 		VOP_FREEBLKS(devvp, fsbtodb(fs, bno), size);
diff --git a/sys/ufs/ffs/ffs_snapshot.c b/sys/ufs/ffs/ffs_snapshot.c
index 1c66031..e5c825d 100644
--- a/sys/ufs/ffs/ffs_snapshot.c
+++ b/sys/ufs/ffs/ffs_snapshot.c
@@ -456,9 +456,12 @@ loop:
 		panic("ffs_snapshot: %d already on list", ip->i_number);
 	snaphead = &ip->i_devvp->v_rdev->si_snapshots;
 	TAILQ_INSERT_TAIL(snaphead, ip, i_nextsnap);
+
+	ASSERT_VOP_LOCKED(ip->i_devvp, "ffs_snapshot devvp");
 	ip->i_devvp->v_rdev->si_copyonwrite = ffs_copyonwrite;
-	ip->i_devvp->v_flag |= VCOPYONWRITE;
-	vp->v_flag |= VSYSTEM;
+	ip->i_devvp->v_vflag |= VV_COPYONWRITE;
+	ASSERT_VOP_LOCKED(vp, "ffs_snapshot vp");
+	vp->v_vflag |= VV_SYSTEM;
 out1:
 	/*
 	 * Resume operation on filesystem.
@@ -1225,9 +1228,10 @@ ffs_snapremove(vp)
 		devvp = ip->i_devvp;
 		TAILQ_REMOVE(&devvp->v_rdev->si_snapshots, ip, i_nextsnap);
 		ip->i_nextsnap.tqe_prev = 0;
+		ASSERT_VOP_LOCKED(devvp, "ffs_snapremove devvp");
 		if (TAILQ_FIRST(&devvp->v_rdev->si_snapshots) == 0) {
 			devvp->v_rdev->si_copyonwrite = 0;
-			devvp->v_flag &= ~VCOPYONWRITE;
+			devvp->v_vflag &= ~VV_COPYONWRITE;
 		}
 	}
 	/*
@@ -1537,9 +1541,10 @@ ffs_snapshot_mount(mp)
 			    ip->i_number);
 		else
 			TAILQ_INSERT_TAIL(snaphead, ip, i_nextsnap);
-		vp->v_flag |= VSYSTEM;
+		vp->v_vflag |= VV_SYSTEM;
 		ump->um_devvp->v_rdev->si_copyonwrite = ffs_copyonwrite;
-		ump->um_devvp->v_flag |= VCOPYONWRITE;
+		ASSERT_VOP_LOCKED(ump->um_devvp, "ffs_snapshot_mount");
+		ump->um_devvp->v_vflag |= VV_COPYONWRITE;
 		VOP_UNLOCK(vp, 0, td);
 	}
 }
@@ -1561,8 +1566,9 @@ ffs_snapshot_unmount(mp)
 		if (xp->i_effnlink > 0)
 			vrele(ITOV(xp));
 	}
+	ASSERT_VOP_LOCKED(ump->um_devvp, "ffs_snapshot_unmount");
 	ump->um_devvp->v_rdev->si_copyonwrite = 0;
-	ump->um_devvp->v_flag &= ~VCOPYONWRITE;
+	ump->um_devvp->v_vflag &= ~VV_COPYONWRITE;
 }
 
 /*
diff --git a/sys/ufs/ffs/ffs_softdep.c b/sys/ufs/ffs/ffs_softdep.c
index 4f73368..1f99ccc 100644
--- a/sys/ufs/ffs/ffs_softdep.c
+++ b/sys/ufs/ffs/ffs_softdep.c
@@ -291,7 +291,7 @@ softdep_panic(msg)
 }
 #endif /* DEBUG */
 
-static	int interlocked_sleep(struct lockit *, int, void *, int,
+static	int interlocked_sleep(struct lockit *, int, void *, struct mtx *, int,
 	    const char *, int);
 
 /*
@@ -306,10 +306,11 @@ static	int interlocked_sleep(struct lockit *, int, void *, int,
 #define	LOCKBUF		2
 
 static int
-interlocked_sleep(lk, op, ident, flags, wmesg, timo)
+interlocked_sleep(lk, op, ident, mtx, flags, wmesg, timo)
 	struct lockit *lk;
 	int op;
 	void *ident;
+	struct mtx *mtx;
 	int flags;
 	const char *wmesg;
 	int timo;
@@ -325,7 +326,7 @@ interlocked_sleep(lk, op, ident, flags, wmesg, timo)
 #	endif /* DEBUG */
 	switch (op) {
 	case SLEEP:
-		retval = tsleep(ident, flags, wmesg, timo);
+		retval = msleep(ident, mtx, flags, wmesg, timo);
 		break;
 	case LOCKBUF:
 		retval = BUF_LOCK((struct buf *)ident, flags);
@@ -386,7 +387,8 @@ sema_get(semap, interlock)
 	if (semap->value++ > 0) {
 		if (interlock != NULL) {
 			interlocked_sleep(interlock, SLEEP, (caddr_t)semap,
-			    semap->prio, semap->name, semap->timo);
+			    NULL, semap->prio, semap->name,
+			    semap->timo);
 			FREE_LOCK(interlock);
 		} else {
 			tsleep((caddr_t)semap, semap->prio, semap->name,
@@ -4778,8 +4780,13 @@ softdep_fsync(vp)
 		 * not now, but then the user was not asking to have it
 		 * written, so we are not breaking any promises.
 		 */
-		if (vp->v_flag & VXLOCK)
+		mp_fixme("This operation is not atomic wrt the rest of the code");
+		VI_LOCK(vp);
+		if (vp->v_iflag & VI_XLOCK) {
+			VI_UNLOCK(vp);
 			break;
+		} else
+			VI_UNLOCK(vp);
 		/*
 		 * We prevent deadlock by always fetching inodes from the
 		 * root, moving down the directory tree. Thus, when fetching
@@ -5502,7 +5509,7 @@ request_cleanup(resource, islocked)
 	proc_waiting += 1;
 	if (handle.callout == NULL)
 		handle = timeout(pause_timer, 0, tickdelay > 2 ? tickdelay : 2);
-	interlocked_sleep(&lk, SLEEP, (caddr_t)&proc_waiting, PPAUSE,
+	interlocked_sleep(&lk, SLEEP, (caddr_t)&proc_waiting, NULL, PPAUSE,
 	    "softupdate", 0);
 	proc_waiting -= 1;
 	if (islocked == 0)
@@ -5760,13 +5767,13 @@ getdirtybuf(bpp, waitfor)
 			if (waitfor != MNT_WAIT)
 				return (0);
 			bp->b_xflags |= BX_BKGRDWAIT;
-			interlocked_sleep(&lk, SLEEP, &bp->b_xflags, PRIBIO,
-			    "getbuf", 0);
+			interlocked_sleep(&lk, SLEEP, &bp->b_xflags, NULL,
+			    PRIBIO, "getbuf", 0);
 			continue;
 		}
 		if (waitfor != MNT_WAIT)
 			return (0);
-		error = interlocked_sleep(&lk, LOCKBUF, bp,
+		error = interlocked_sleep(&lk, LOCKBUF, bp, NULL, 
 		    LK_EXCLUSIVE | LK_SLEEPFAIL, 0, 0);
 		if (error != ENOLCK) {
 			FREE_LOCK(&lk);
@@ -5793,11 +5800,13 @@ drain_output(vp, islocked)
 
 	if (!islocked)
 		ACQUIRE_LOCK(&lk);
+	VI_LOCK(vp);
 	while (vp->v_numoutput) {
-		vp->v_flag |= VBWAIT;
-		interlocked_sleep(&lk, SLEEP, (caddr_t)&vp->v_numoutput,
-		    PRIBIO + 1, "drainvp", 0);
+		vp->v_iflag |= VI_BWAIT;
+		interlocked_sleep(&lk, SLEEP, (caddr_t)&vp->v_numoutput, 
+		    VI_MTX(vp), PRIBIO + 1, "drainvp", 0);
 	}
+	VI_UNLOCK(vp);
 	if (!islocked)
 		FREE_LOCK(&lk);
 }
diff --git a/sys/ufs/ffs/ffs_vfsops.c b/sys/ufs/ffs/ffs_vfsops.c
index fa0bffa..e5c62b0 100644
--- a/sys/ufs/ffs/ffs_vfsops.c
+++ b/sys/ufs/ffs/ffs_vfsops.c
@@ -1001,7 +1001,8 @@ ffs_flushfiles(mp, flags, td)
 		 */
 	}
 #endif
-	if (ump->um_devvp->v_flag & VCOPYONWRITE) {
+	ASSERT_VOP_LOCKED(ump->um_devvp, "ffs_flushfiles");
+	if (ump->um_devvp->v_vflag & VV_COPYONWRITE) {
 		if ((error = vflush(mp, 0, SKIPSYSTEM | flags)) != 0)
 			return (error);
 		ffs_snapshot_unmount(mp);
diff --git a/sys/ufs/ffs/ffs_vnops.c b/sys/ufs/ffs/ffs_vnops.c
index 0c5e8c4..9356ff9 100644
--- a/sys/ufs/ffs/ffs_vnops.c
+++ b/sys/ufs/ffs/ffs_vnops.c
@@ -234,11 +234,13 @@ loop:
 	}
 
 	if (wait) {
+		VI_LOCK(vp);
 		while (vp->v_numoutput) {
-			vp->v_flag |= VBWAIT;
-			(void) tsleep((caddr_t)&vp->v_numoutput,
-					PRIBIO + 4, "ffsfsn", 0);
+			vp->v_iflag |= VI_BWAIT;
+			msleep((caddr_t)&vp->v_numoutput, VI_MTX(vp),
+			    PRIBIO + 4, "ffsfsn", 0);
   		}
+		VI_UNLOCK(vp);
 
 		/* 
 		 * Ensure that any filesystem metatdata associated
diff --git a/sys/ufs/ufs/ufs_extattr.c b/sys/ufs/ufs/ufs_extattr.c
index 486263a..49ab022 100644
--- a/sys/ufs/ufs/ufs_extattr.c
+++ b/sys/ufs/ufs/ufs_extattr.c
@@ -659,7 +659,8 @@ ufs_extattr_enable(struct ufsmount *ump, int attrnamespace,
 		goto free_exit;
 	}
 
-	backing_vnode->v_flag |= VSYSTEM;
+	ASSERT_VOP_LOCKED(backing_vnode, "ufs_extattr_enable");
+	backing_vnode->v_vflag |= VV_SYSTEM;
 	LIST_INSERT_HEAD(&ump->um_extattr.uepm_list, attribute,
 	    uele_entries);
 
@@ -689,7 +690,8 @@ ufs_extattr_disable(struct ufsmount *ump, int attrnamespace,
 
 	LIST_REMOVE(uele, uele_entries);
 
-	uele->uele_backing_vnode->v_flag &= ~VSYSTEM;
+	ASSERT_VOP_LOCKED(uele->uele_backing_vnode, "ufs_extattr_disable");
+	uele->uele_backing_vnode->v_vflag &= ~VV_SYSTEM;
 	error = vn_close(uele->uele_backing_vnode, FREAD|FWRITE,
 	    td->td_ucred, td);
 
diff --git a/sys/ufs/ufs/ufs_quota.c b/sys/ufs/ufs/ufs_quota.c
index dcbe6f79..57319f0 100644
--- a/sys/ufs/ufs/ufs_quota.c
+++ b/sys/ufs/ufs/ufs_quota.c
@@ -417,7 +417,8 @@ quotaon(td, mp, type, fname)
 		quotaoff(td, mp, type);
 	ump->um_qflags[type] |= QTF_OPENING;
 	mp->mnt_flag |= MNT_QUOTA;
-	vp->v_flag |= VSYSTEM;
+	ASSERT_VOP_LOCKED(vp, "quotaon");
+	vp->v_vflag |= VV_SYSTEM;
 	*vpp = vp;
 	/*
 	 * Save the credential of the process that turned on quotas.
@@ -523,7 +524,8 @@ again:
 	}
 	mtx_unlock(&mntvnode_mtx);
 	dqflush(qvp);
-	qvp->v_flag &= ~VSYSTEM;
+	ASSERT_VOP_LOCKED(qvp, "quotaoff");
+	qvp->v_vflag &= ~VV_SYSTEM;
 	error = vn_close(qvp, FREAD|FWRITE, td->td_ucred, td);
 	ump->um_quotas[type] = NULLVP;
 	crfree(ump->um_cred[type]);
diff --git a/sys/ufs/ufs/ufs_vnops.c b/sys/ufs/ufs/ufs_vnops.c
index 087cca7..1f56ee6 100644
--- a/sys/ufs/ufs/ufs_vnops.c
+++ b/sys/ufs/ufs/ufs_vnops.c
@@ -793,7 +793,7 @@ ufs_remove(ap)
 	}
 	error = ufs_dirremove(dvp, ip, ap->a_cnp->cn_flags, 0);
 	if (ip->i_nlink <= 0)
-		vp->v_flag |= VNOSYNC;
+		vp->v_vflag |= VV_NOSYNC;
 	VN_KNOTE(vp, NOTE_DELETE);
 	VN_KNOTE(dvp, NOTE_WRITE);
 out:
@@ -2289,8 +2289,9 @@ ufs_vinit(mntp, specops, fifoops, vpp)
 		break;
 
 	}
+	ASSERT_VOP_LOCKED(vp, "ufs_vinit");
 	if (ip->i_number == ROOTINO)
-		vp->v_flag |= VROOT;
+		vp->v_vflag |= VV_ROOT;
 	/*
 	 * Initialize modrev times
 	 */
diff --git a/sys/vm/vm_object.c b/sys/vm/vm_object.c
index a4353d9..f13bbac 100644
--- a/sys/vm/vm_object.c
+++ b/sys/vm/vm_object.c
@@ -415,7 +415,8 @@ vm_object_vndeallocate(vm_object_t object)
 
 	object->ref_count--;
 	if (object->ref_count == 0) {
-		vp->v_flag &= ~VTEXT;
+		mp_fixme("Unlocked vflag access.");
+		vp->v_vflag &= ~VV_TEXT;
 #ifdef ENABLE_VFS_IOOPT
 		vm_object_clear_flag(object, OBJ_OPT);
 #endif
@@ -760,11 +761,10 @@ vm_object_page_clean(vm_object_t object, vm_pindex_t start, vm_pindex_t end, int
 		vm_object_clear_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY);
 		if (object->type == OBJT_VNODE &&
 		    (vp = (struct vnode *)object->handle) != NULL) {
-			if (vp->v_flag & VOBJDIRTY) {
-				mtx_lock(&vp->v_interlock);
-				vp->v_flag &= ~VOBJDIRTY;
-				mtx_unlock(&vp->v_interlock);
-			}
+			VI_LOCK(vp);
+			if (vp->v_iflag & VI_OBJDIRTY)
+				vp->v_iflag &= ~VI_OBJDIRTY;
+			VI_UNLOCK(vp);
 		}
 	}
 
@@ -1900,11 +1900,10 @@ vm_object_set_writeable_dirty(vm_object_t object)
 	vm_object_set_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY);
 	if (object->type == OBJT_VNODE &&
 	    (vp = (struct vnode *)object->handle) != NULL) {
-		if ((vp->v_flag & VOBJDIRTY) == 0) {
-			mtx_lock(&vp->v_interlock);
-			vp->v_flag |= VOBJDIRTY;
-			mtx_unlock(&vp->v_interlock);
-		}
+		VI_LOCK(vp);
+		if ((vp->v_iflag & VI_OBJDIRTY) == 0)
+			vp->v_iflag |= VI_OBJDIRTY;
+		VI_UNLOCK(vp);
 	}
 }
 
diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c
index 97a7b5d..5d61668 100644
--- a/sys/vm/vm_page.c
+++ b/sys/vm/vm_page.c
@@ -1174,8 +1174,12 @@ vm_page_free_toq(vm_page_t m)
 	) {
 		struct vnode *vp = (struct vnode *)object->handle;
 
-		if (vp && VSHOULDFREE(vp))
-			vfree(vp);
+		if (vp) {
+			VI_LOCK(vp);
+			if (VSHOULDFREE(vp))
+				vfree(vp);
+			VI_UNLOCK(vp);
+		}
 	}
 
 	/*
diff --git a/sys/vm/vm_swap.c b/sys/vm/vm_swap.c
index bdaf1a7..c12b532 100644
--- a/sys/vm/vm_swap.c
+++ b/sys/vm/vm_swap.c
@@ -142,11 +142,13 @@ swapdev_strategy(ap)
 	if (bp->b_iocmd == BIO_WRITE) {
 		vp = bp->b_vp;
 		if (vp) {
+			VI_LOCK(vp);
 			vp->v_numoutput--;
-			if ((vp->v_flag & VBWAIT) && vp->v_numoutput <= 0) {
-				vp->v_flag &= ~VBWAIT;
+			if ((vp->v_iflag & VI_BWAIT) && vp->v_numoutput <= 0) {
+				vp->v_iflag &= ~VI_BWAIT;
 				wakeup(&vp->v_numoutput);
 			}
+			VI_UNLOCK(vp);
 		}
 		sp->sw_vp->v_numoutput++;
 	}
diff --git a/sys/vm/vnode_pager.c b/sys/vm/vnode_pager.c
index 30f069a..68a47d0 100644
--- a/sys/vm/vnode_pager.c
+++ b/sys/vm/vnode_pager.c
@@ -125,11 +125,13 @@ vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
 	 * Prevent race condition when allocating the object. This
 	 * can happen with NFS vnodes since the nfsnode isn't locked.
 	 */
-	while (vp->v_flag & VOLOCK) {
-		vp->v_flag |= VOWANT;
-		tsleep(vp, PVM, "vnpobj", 0);
+	VI_LOCK(vp);
+	while (vp->v_iflag & VI_OLOCK) {
+		vp->v_iflag |= VI_OWANT;
+		msleep(vp, VI_MTX(vp), PVM, "vnpobj", 0);
 	}
-	vp->v_flag |= VOLOCK;
+	vp->v_iflag |= VI_OLOCK;
+	VI_UNLOCK(vp);
 
 	/*
 	 * If the object is being terminated, wait for it to
@@ -156,12 +158,14 @@ vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
 	} else {
 		object->ref_count++;
 	}
+	VI_LOCK(vp);
 	vp->v_usecount++;
-	vp->v_flag &= ~VOLOCK;
-	if (vp->v_flag & VOWANT) {
-		vp->v_flag &= ~VOWANT;
+	vp->v_iflag &= ~VI_OLOCK;
+	if (vp->v_iflag & VI_OWANT) {
+		vp->v_iflag &= ~VI_OWANT;
 		wakeup(vp);
 	}
+	VI_UNLOCK(vp);
 	mtx_unlock(&Giant);
 	return (object);
 }
@@ -180,8 +184,9 @@ vnode_pager_dealloc(object)
 
 	object->handle = NULL;
 	object->type = OBJT_DEAD;
+	ASSERT_VOP_LOCKED(vp, "vnode_pager_dealloc");
 	vp->v_object = NULL;
-	vp->v_flag &= ~(VTEXT | VOBJBUF);
+	vp->v_vflag &= ~(VV_TEXT | VV_OBJBUF);
 }
 
 static boolean_t
@@ -204,9 +209,12 @@ vnode_pager_haspage(object, pindex, before, after)
 	 * If no vp or vp is doomed or marked transparent to VM, we do not
 	 * have the page.
 	 */
-	if ((vp == NULL) || (vp->v_flag & VDOOMED))
+	if (vp == NULL)
 		return FALSE;
 
+	mp_fixme("Unlocked iflags access");
+	if (vp->v_iflag & VI_DOOMED)
+		return FALSE;
 	/*
 	 * If filesystem no longer mounted or offset beyond end of file we do
 	 * not have the page.