ml_iterator_vfs_busy

Drop the mountlist processing from vfs_busy() and vfs_unbusy().

diff -r 28fea04e7b15 -r bb476fea44cd sys/compat/common/vfs_syscalls_20.c
--- a/sys/compat/common/vfs_syscalls_20.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/compat/common/vfs_syscalls_20.c	Thu Mar 30 11:17:57 2017 +0200
@@ -219,19 +219,19 @@
 		if (sfsp && count < maxcount) {
 			error = dostatvfs(mp, sbuf, l, SCARG(uap, flags), 0);
 			if (error) {
-				vfs_unbusy(mp, false, NULL);
+				vfs_unbusy(mp, false);
 				continue;
 			}
 			error = vfs2fs(sfsp, sbuf);
 			if (error) {
-				vfs_unbusy(mp, false, NULL);
+				vfs_unbusy(mp, false);
 				goto out;
 			}
 			sfsp++;
 			root |= strcmp(sbuf->f_mntonname, "/") == 0;
 		}
 		count++;
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 	}
 	if (root == 0 && l->l_proc->p_cwdi->cwdi_rdir) {
 		/*
diff -r 28fea04e7b15 -r bb476fea44cd sys/compat/netbsd32/netbsd32_compat_20.c
--- a/sys/compat/netbsd32/netbsd32_compat_20.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/compat/netbsd32/netbsd32_compat_20.c	Thu Mar 30 11:17:57 2017 +0200
@@ -102,21 +102,21 @@
 		if (sfsp && count < maxcount) {
 			error = dostatvfs(mp, sb, l, SCARG(uap, flags), 0);
 			if (error) {
-				vfs_unbusy(mp, false, NULL);
+				vfs_unbusy(mp, false);
 				error = 0;
 				continue;
 			}
 			compat_20_netbsd32_from_statvfs(sb, &sb32);
 			error = copyout(&sb32, sfsp, sizeof(sb32));
 			if (error) {
-				vfs_unbusy(mp, false, NULL);
+				vfs_unbusy(mp, false);
 				goto out;
 			}
 			sfsp = (char *)sfsp + sizeof(sb32);
 			root |= strcmp(sb->f_mntonname, "/") == 0;
 		}
 		count++;
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 	}
 
 	if (root == 0 && p->p_cwdi->cwdi_rdir) {
diff -r 28fea04e7b15 -r bb476fea44cd sys/compat/osf1/osf1_mount.c
--- a/sys/compat/osf1/osf1_mount.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/compat/osf1/osf1_mount.c	Thu Mar 30 11:17:57 2017 +0200
@@ -161,14 +161,14 @@
 				osf1_cvt_statfs_from_native(sp, &osfs);
 				if ((error = copyout(&osfs, osf_sfsp,
 				    sizeof (struct osf1_statfs)))) {
-				    	vfs_unbusy(mp, false, NULL);
+				    	vfs_unbusy(mp, false);
 					return (error);
 				}
 				osf_sfsp += sizeof (struct osf1_statfs);
 			}
 		}
 		count++;
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 	}
 	mountlist_iterator_destroy(iter);
 	if (osf_sfsp && count > maxcount)
diff -r 28fea04e7b15 -r bb476fea44cd sys/compat/ultrix/ultrix_fs.c
--- a/sys/compat/ultrix/ultrix_fs.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/compat/ultrix/ultrix_fs.c	Thu Mar 30 11:17:57 2017 +0200
@@ -280,14 +280,14 @@
 				make_ultrix_mntent(sp, &tem);
 				if ((error = copyout((void *)&tem, sfsp,
 				    sizeof(tem))) != 0) {
-					vfs_unbusy(mp, false, NULL);
+					vfs_unbusy(mp, false);
 					goto bad;
 				}
 				sfsp++;
 				count++;
 			}
 		}
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 	}
 	mountlist_iterator_destroy(iter);
 
diff -r 28fea04e7b15 -r bb476fea44cd sys/fs/cd9660/cd9660_vfsops.c
--- a/sys/fs/cd9660/cd9660_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/fs/cd9660/cd9660_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
@@ -191,13 +191,13 @@
 
 	args.flags = ISOFSMNT_ROOT;
 	if ((error = iso_mountfs(rootvp, mp, l, &args)) != 0) {
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 		vfs_destroy(mp);
 		return (error);
 	}
 	mountlist_append(mp);
 	(void)cd9660_statvfs(mp, &mp->mnt_stat);
-	vfs_unbusy(mp, false, NULL);
+	vfs_unbusy(mp, false);
 	return (0);
 }
 
diff -r 28fea04e7b15 -r bb476fea44cd sys/fs/filecorefs/filecore_vfsops.c
--- a/sys/fs/filecorefs/filecore_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/fs/filecorefs/filecore_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
@@ -201,13 +201,13 @@
 
 	args.flags = FILECOREMNT_ROOT;
 	if ((error = filecore_mountfs(rootvp, mp, p, &args)) != 0) {
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 		vfs_destroy(mp);
 		return (error);
 	}
 	mountlist_append(mp);
 	(void)filecore_statvfs(mp, &mp->mnt_stat, p);
-	vfs_unbusy(mp, false, NULL);
+	vfs_unbusy(mp, false);
 	return (0);
 }
 #endif
diff -r 28fea04e7b15 -r bb476fea44cd sys/fs/msdosfs/msdosfs_vfsops.c
--- a/sys/fs/msdosfs/msdosfs_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/fs/msdosfs/msdosfs_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
@@ -247,14 +247,14 @@
 	args.dirmask = 0777;
 
 	if ((error = msdosfs_mountfs(rootvp, mp, l, &args)) != 0) {
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 		vfs_destroy(mp);
 		return (error);
 	}
 
 	if ((error = update_mp(mp, &args)) != 0) {
 		(void)msdosfs_unmount(mp, 0);
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 		vfs_destroy(mp);
 		vrele(rootvp);
 		return (error);
@@ -262,7 +262,7 @@
 
 	mountlist_append(mp);
 	(void)msdosfs_statvfs(mp, &mp->mnt_stat);
-	vfs_unbusy(mp, false, NULL);
+	vfs_unbusy(mp, false);
 	return (0);
 }
 
diff -r 28fea04e7b15 -r bb476fea44cd sys/fs/ntfs/ntfs_vfsops.c
--- a/sys/fs/ntfs/ntfs_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/fs/ntfs/ntfs_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
@@ -115,14 +115,14 @@
 	args.mode = 0777;
 
 	if ((error = ntfs_mountfs(rootvp, mp, &args, l)) != 0) {
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 		vfs_destroy(mp);
 		return (error);
 	}
 
 	mountlist_append(mp);
 	(void)ntfs_statvfs(mp, &mp->mnt_stat);
-	vfs_unbusy(mp, false, NULL);
+	vfs_unbusy(mp, false);
 	return (0);
 }
 
diff -r 28fea04e7b15 -r bb476fea44cd sys/fs/union/union_vnops.c
--- a/sys/fs/union/union_vnops.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/fs/union/union_vnops.c	Thu Mar 30 11:17:57 2017 +0200
@@ -250,11 +250,11 @@
 	 */
 	while (dvp != udvp && (dvp->v_type == VDIR) &&
 	       (mp = dvp->v_mountedhere)) {
-		if (vfs_busy(mp, NULL))
+		if (vfs_busy(mp, 0))
 			continue;
 		vput(dvp);
 		error = VFS_ROOT(mp, &tdvp);
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 		if (error) {
 			return (error);
 		}
diff -r 28fea04e7b15 -r bb476fea44cd sys/fs/v7fs/v7fs_vfsops.c
--- a/sys/fs/v7fs/v7fs_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/fs/v7fs/v7fs_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
@@ -576,14 +576,14 @@
 
 	if ((error = v7fs_mountfs(rootvp, mp, _BYTE_ORDER))) {
 		DPRINTF("mountfs error=%d\n", error);
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 		vfs_destroy(mp);
 		return error;
 	}
 
 	mountlist_append(mp);
 
-	vfs_unbusy(mp, false, NULL);
+	vfs_unbusy(mp, false);
 
 	return 0;
 }
diff -r 28fea04e7b15 -r bb476fea44cd sys/kern/kern_veriexec.c
--- a/sys/kern/kern_veriexec.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/kern/kern_veriexec.c	Thu Mar 30 11:17:57 2017 +0200
@@ -1371,7 +1371,7 @@
 		fileassoc_table_run(mp, veriexec_hook,
 		    (fileassoc_cb_t)veriexec_file_dump, rarray);
 
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 	}
 	mountlist_iterator_destroy(iter);
 
@@ -1393,7 +1393,7 @@
 		if (lerror && lerror != ENOENT)
 			error = lerror;
 
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 	}
 	mountlist_iterator_destroy(iter);
 
diff -r 28fea04e7b15 -r bb476fea44cd sys/kern/vfs_lookup.c
--- a/sys/kern/vfs_lookup.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/kern/vfs_lookup.c	Thu Mar 30 11:17:57 2017 +0200
@@ -1087,7 +1087,7 @@
 
 		KASSERT(searchdir != foundobj);
 
-		error = vfs_busy(mp, NULL);
+		error = vfs_busy(mp, 0);
 		if (error != 0) {
 			vput(foundobj);
 			goto done;
@@ -1097,7 +1097,7 @@
 		}
 		vput(foundobj);
 		error = VFS_ROOT(mp, &foundobj);
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 		if (error) {
 			if (searchdir != NULL) {
 				vn_lock(searchdir, LK_EXCLUSIVE | LK_RETRY);
diff -r 28fea04e7b15 -r bb476fea44cd sys/kern/vfs_mount.c
--- a/sys/kern/vfs_mount.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/kern/vfs_mount.c	Thu Mar 30 11:17:57 2017 +0200
@@ -165,7 +165,7 @@
 	mutex_init(&mp->mnt_unmounting, MUTEX_DEFAULT, IPL_NONE);
 	mutex_init(&mp->mnt_renamelock, MUTEX_DEFAULT, IPL_NONE);
 	mutex_init(&mp->mnt_updating, MUTEX_DEFAULT, IPL_NONE);
-	error = vfs_busy(mp, NULL);
+	error = vfs_busy(mp, 0);
 	KASSERT(error == 0);
 	mp->mnt_vnodecovered = vp;
 	mount_initspecific(mp);
@@ -307,26 +307,26 @@
  * => Will fail if the file system is being unmounted, or is unmounted.
  */
 int
-vfs_busy(struct mount *mp, struct mount **nextp)
+vfs_busy(struct mount *mp, int flags)
 {
 
 	KASSERT(mp->mnt_refcnt > 0);
+	KASSERT((flags & ~MNT_NOWAIT) == 0);
 
-	mutex_enter(&mp->mnt_unmounting);
+	if ((flags & MNT_NOWAIT) != 0) {
+		if (!mutex_tryenter(&mp->mnt_unmounting))
+			return EBUSY;
+	} else {
+		mutex_enter(&mp->mnt_unmounting);
+	}
+
 	if (__predict_false((mp->mnt_iflag & IMNT_GONE) != 0)) {
 		mutex_exit(&mp->mnt_unmounting);
-		if (nextp != NULL) {
-			KASSERT(mutex_owned(&mountlist_lock));
-			*nextp = TAILQ_NEXT(mp, mnt_list);
-		}
 		return ENOENT;
 	}
 	++mp->mnt_busynest;
 	KASSERT(mp->mnt_busynest != 0);
 	mutex_exit(&mp->mnt_unmounting);
-	if (nextp != NULL) {
-		mutex_exit(&mountlist_lock);
-	}
 	atomic_inc_uint(&mp->mnt_refcnt);
 	return 0;
 }
@@ -337,17 +337,13 @@
  * Every successful vfs_busy() call must be undone by a vfs_unbusy() call.
  *
  * => If keepref is true, preserve reference added by vfs_busy().
- * => If nextp != NULL, acquire mountlist_lock.
  */
 void
-vfs_unbusy(struct mount *mp, bool keepref, struct mount **nextp)
+vfs_unbusy(struct mount *mp, bool keepref)
 {
 
 	KASSERT(mp->mnt_refcnt > 0);
 
-	if (nextp != NULL) {
-		mutex_enter(&mountlist_lock);
-	}
 	mutex_enter(&mp->mnt_unmounting);
 	KASSERT(mp->mnt_busynest != 0);
 	mp->mnt_busynest--;
@@ -355,10 +351,6 @@
 	if (!keepref) {
 		vfs_destroy(mp);
 	}
-	if (nextp != NULL) {
-		KASSERT(mutex_owned(&mountlist_lock));
-		*nextp = TAILQ_NEXT(mp, mnt_list);
-	}
 }
 
 struct vnode_iterator {
@@ -732,7 +724,7 @@
 	}
 
 	if ((error = fstrans_mount(mp)) != 0) {
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 		vfs_destroy(mp);
 		return error;
 	}
@@ -799,7 +791,7 @@
 	mutex_exit(&mp->mnt_updating);
 
 	/* Hold an additional reference to the mount across VFS_START(). */
-	vfs_unbusy(mp, true, NULL);
+	vfs_unbusy(mp, true);
 	(void) VFS_STATVFS(mp, &mp->mnt_stat);
 	error = VFS_START(mp, 0);
        if (error) {
@@ -820,7 +812,7 @@
 	vp->v_mountedhere = NULL;
 	mutex_exit(&mp->mnt_updating);
 	fstrans_unmount(mp);
-	vfs_unbusy(mp, false, NULL);
+	vfs_unbusy(mp, false);
 	vfs_destroy(mp);
 
 	return error;
@@ -1001,12 +993,12 @@
 	mountlist_iterator_init_reverse(&iter);
 	while ((mp = mountlist_iterator_next(iter, 0)) != NULL) {
 		if (nmp == NULL || mp->mnt_gen > nmp->mnt_gen) {
-			vfs_unbusy(mp, true, NULL);
+			vfs_unbusy(mp, true);
 			if (nmp)
 				vfs_destroy(nmp);
 			nmp = mp;
 		} else
-			vfs_unbusy(mp, false, NULL);
+			vfs_unbusy(mp, false);
 	}
 	mountlist_iterator_destroy(iter);
 	if (nmp == NULL) {
@@ -1047,7 +1039,7 @@
 		    (void *)mp, mp->mnt_stat.f_mntonname,
 		    mp->mnt_stat.f_mntfromname);
 #endif
-		vfs_unbusy(mp, true, NULL);
+		vfs_unbusy(mp, true);
 		if ((error = dounmount(mp, force ? MNT_FORCE : 0, l)) == 0) {
 			vfs_unmount_print(mp, "");
 			progress = true;
@@ -1251,7 +1243,7 @@
 		mountlist_iterator_init(&iter);
 		mp = mountlist_iterator_next(iter, 0);
 		KASSERT(mp != NULL);
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 		mountlist_iterator_destroy(iter);
 
 		mp->mnt_flag |= MNT_ROOTFS;
@@ -1571,7 +1563,7 @@
 		mutex_exit(&mount_list_lock);
 
 		/* Try to mark this mount busy and return on success. */
-		if (vfs_busy(mp, NULL) == 0) {
+		if (vfs_busy(mp, flags) == 0) {
 			vfs_destroy(mp);
 			return mp;
 		}
diff -r 28fea04e7b15 -r bb476fea44cd sys/kern/vfs_subr.c
--- a/sys/kern/vfs_subr.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/kern/vfs_subr.c	Thu Mar 30 11:17:57 2017 +0200
@@ -778,7 +778,7 @@
 		while ((mp = mountlist_iterator_next(iter, MNT_NOWAIT)) != NULL) {
 			if ((mp->mnt_iflag & IMNT_ONWORKLIST) == 0 ||
 			    mp->mnt_synclist_slot != syncer_delayno) {
-				vfs_unbusy(mp, false, NULL);
+				vfs_unbusy(mp, false);
 				continue;
 			}
 			mp->mnt_synclist_slot = sync_delay_slot(sync_delay(mp));
@@ -786,7 +786,7 @@
 				VFS_SYNC(mp, MNT_LAZY, curlwp->l_cred);
 				fstrans_done(mp);
 			}
-			vfs_unbusy(mp, false, NULL);
+			vfs_unbusy(mp, false);
 		}
 		mountlist_iterator_destroy(iter);
 
@@ -995,7 +995,7 @@
 			if (bp + VPTRSZ + VNODESZ > ewhere) {
 				vrele(vp);
 				vfs_vnode_iterator_destroy(marker);
-				vfs_unbusy(mp, false, NULL);
+				vfs_unbusy(mp, false);
 				mountlist_iterator_destroy(iter);
 				sysctl_relock();
 				*sizep = bp - where;
@@ -1006,7 +1006,7 @@
 			    (error = copyout(&vbuf, bp + VPTRSZ, VNODESZ))) {
 				vrele(vp);
 				vfs_vnode_iterator_destroy(marker);
-				vfs_unbusy(mp, false, NULL);
+				vfs_unbusy(mp, false);
 				mountlist_iterator_destroy(iter);
 				sysctl_relock();
 				return (error);
@@ -1015,7 +1015,7 @@
 			bp += VPTRSZ + VNODESZ;
 		}
 		vfs_vnode_iterator_destroy(marker);
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 	}
 	mountlist_iterator_destroy(iter);
 	sysctl_relock();
@@ -1666,7 +1666,7 @@
 			if (VOP_ISLOCKED(vp))
 				vprint(NULL, vp);
 		}
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 	}
 }
 
diff -r 28fea04e7b15 -r bb476fea44cd sys/kern/vfs_syscalls.c
--- a/sys/kern/vfs_syscalls.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/kern/vfs_syscalls.c	Thu Mar 30 11:17:57 2017 +0200
@@ -282,7 +282,7 @@
 	if (error)
 		goto out;
 
-	if (vfs_busy(mp, NULL)) {
+	if (vfs_busy(mp, 0)) {
 		error = EPERM;
 		goto out;
 	}
@@ -345,7 +345,7 @@
 	}
 	mutex_exit(&mp->mnt_updating);
 	vfs_resume(mp);
-	vfs_unbusy(mp, false, NULL);
+	vfs_unbusy(mp, false);
 
 	if ((error == 0) && !(saved_flags & MNT_EXTATTR) && 
 	    (flags & MNT_EXTATTR)) {
@@ -438,7 +438,7 @@
 	if ((vp->v_vflag & VV_ROOT) == 0)
 		return EINVAL;
 
-	if (vfs_busy(mp, NULL))
+	if (vfs_busy(mp, 0))
 		return EPERM;
 
 	mutex_enter(&mp->mnt_updating);
@@ -448,7 +448,7 @@
 	mp->mnt_flag &= ~MNT_OP_FLAGS;
 	mutex_exit(&mp->mnt_updating);
 
-	vfs_unbusy(mp, false, NULL);
+	vfs_unbusy(mp, false);
 	return (error);
 }
 
@@ -658,7 +658,7 @@
 		}
 		mutex_exit(&mp->mnt_updating);
 		fstrans_done(mp);
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 	}
 	mountlist_iterator_destroy(iter);
 #ifdef DEBUG
@@ -1264,20 +1264,20 @@
 		if (sfsp && count < maxcount) {
 			error = dostatvfs(mp, sb, l, flags, 0);
 			if (error) {
-				vfs_unbusy(mp, false, NULL);
+				vfs_unbusy(mp, false);
 				error = 0;
 				continue;
 			}
 			error = copyfn(sb, sfsp, entry_sz);
 			if (error) {
-				vfs_unbusy(mp, false, NULL);
+				vfs_unbusy(mp, false);
 				goto out;
 			}
 			sfsp = (char *)sfsp + entry_sz;
 			root |= strcmp(sb->f_mntonname, "/") == 0;
 		}
 		count++;
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 	}
 
 	if (root == 0 && p->p_cwdi->cwdi_rdir) {
@@ -1352,12 +1352,12 @@
 		goto out;
 	}
 	while ((mp = vp->v_mountedhere) != NULL) {
-		error = vfs_busy(mp, NULL);
+		error = vfs_busy(mp, 0);
 		vput(vp);
 		if (error != 0)
 			goto out;
 		error = VFS_ROOT(mp, &tdp);
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 		if (error)
 			goto out;
 		vp = tdp;
diff -r 28fea04e7b15 -r bb476fea44cd sys/kern/vfs_trans.c
--- a/sys/kern/vfs_trans.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/kern/vfs_trans.c	Thu Mar 30 11:17:57 2017 +0200
@@ -191,7 +191,7 @@
 	int error;
 	struct fstrans_mount_info *newfmi;
 
-	error = vfs_busy(mp, NULL);
+	error = vfs_busy(mp, 0);
 	if (error)
 		return error;
 	newfmi = kmem_alloc(sizeof(*newfmi), KM_SLEEP);
@@ -205,7 +205,7 @@
 	mp->mnt_iflag |= IMNT_HAS_TRANS;
 	mutex_exit(&fstrans_mount_lock);
 
-	vfs_unbusy(mp, true, NULL);
+	vfs_unbusy(mp, true);
 
 	return 0;
 }
diff -r 28fea04e7b15 -r bb476fea44cd sys/kern/vfs_vnode.c
--- a/sys/kern/vfs_vnode.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/kern/vfs_vnode.c	Thu Mar 30 11:17:57 2017 +0200
@@ -1269,7 +1269,7 @@
 	mutex_exit(&vcache_lock);
 
 	/* Allocate and initialize a new vcache / vnode pair. */
-	error = vfs_busy(mp, NULL);
+	error = vfs_busy(mp, 0);
 	if (error)
 		return error;
 	new_vip = vcache_alloc();
@@ -1286,7 +1286,7 @@
 	/* If another thread beat us inserting this node, retry. */
 	if (vip != new_vip) {
 		vcache_dealloc(new_vip);
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 		goto again;
 	}
 	mutex_exit(&vcache_lock);
@@ -1298,7 +1298,7 @@
 		SLIST_REMOVE(&vcache_hashtab[hash & vcache_hashmask],
 		    new_vip, vnode_impl, vi_hash);
 		vcache_dealloc(new_vip);
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 		KASSERT(*vpp == NULL);
 		return error;
 	}
@@ -1308,7 +1308,7 @@
 	vfs_insmntque(vp, mp);
 	if ((mp->mnt_iflag & IMNT_MPSAFE) != 0)
 		vp->v_vflag |= VV_MPSAFE;
-	vfs_unbusy(mp, true, NULL);
+	vfs_unbusy(mp, true);
 
 	/* Finished loading, finalize node. */
 	mutex_enter(&vcache_lock);
@@ -1336,7 +1336,7 @@
 	*vpp = NULL;
 
 	/* Allocate and initialize a new vcache / vnode pair. */
-	error = vfs_busy(mp, NULL);
+	error = vfs_busy(mp, 0);
 	if (error)
 		return error;
 	vip = vcache_alloc();
@@ -1349,7 +1349,7 @@
 	if (error) {
 		mutex_enter(&vcache_lock);
 		vcache_dealloc(vip);
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 		KASSERT(*vpp == NULL);
 		return error;
 	}
@@ -1373,7 +1373,7 @@
 	vfs_insmntque(vp, mp);
 	if ((mp->mnt_iflag & IMNT_MPSAFE) != 0)
 		vp->v_vflag |= VV_MPSAFE;
-	vfs_unbusy(mp, true, NULL);
+	vfs_unbusy(mp, true);
 
 	/* Finished loading, finalize node. */
 	mutex_enter(&vcache_lock);
diff -r 28fea04e7b15 -r bb476fea44cd sys/miscfs/procfs/procfs_linux.c
--- a/sys/miscfs/procfs/procfs_linux.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/miscfs/procfs/procfs_linux.c	Thu Mar 30 11:17:57 2017 +0200
@@ -618,7 +618,7 @@
 			root |= procfs_format_sfs(&mtab, &mtabsz, bf, LBFSZ,
 			    &sfs, curl, 0);
 
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 	}
 	mountlist_iterator_destroy(iter);
 
diff -r 28fea04e7b15 -r bb476fea44cd sys/nfs/nfs_export.c
--- a/sys/nfs/nfs_export.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/nfs/nfs_export.c	Thu Mar 30 11:17:57 2017 +0200
@@ -211,7 +211,7 @@
 		netexport_wrlock();
 		ne = TAILQ_FIRST(&netexport_list);
 		mp = ne->ne_mount;
-		error = vfs_busy(mp, NULL);
+		error = vfs_busy(mp, 0);
 		netexport_wrunlock();
 		if (error != 0) {
 			kpause("nfsfini", false, hz, NULL);
@@ -220,7 +220,7 @@
 		mutex_enter(&mp->mnt_updating);	/* mnt_flag */
 		netexport_unmount(mp);
 		mutex_exit(&mp->mnt_updating);	/* mnt_flag */
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 	}
 	rw_destroy(&netexport_lock);
 }
@@ -284,7 +284,7 @@
 	}
 
 	/* Mark the file system busy. */
-	error = vfs_busy(mp, NULL);
+	error = vfs_busy(mp, 0);
 	vput(vp);
 	if (error != 0)
 		return error;
@@ -332,7 +332,7 @@
 	netexport_wrunlock();
 	if (nmp == NULL)
 		mutex_exit(&mp->mnt_updating);	/* mnt_flag */
-	vfs_unbusy(mp, false, NULL);
+	vfs_unbusy(mp, false);
 	return error;
 }
 
diff -r 28fea04e7b15 -r bb476fea44cd sys/nfs/nfs_vfsops.c
--- a/sys/nfs/nfs_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/nfs/nfs_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
@@ -380,7 +380,7 @@
 	mountlist_append(mp);
 	rootvp = vp;
 	mp->mnt_vnodecovered = NULLVP;
-	vfs_unbusy(mp, false, NULL);
+	vfs_unbusy(mp, false);
 
 	/* Get root attributes (for the time). */
 	vn_lock(vp, LK_SHARED | LK_RETRY);
@@ -435,7 +435,7 @@
 	error = mountnfs(&ndmntp->ndm_args, mp, m, mntname,
 			 ndmntp->ndm_args.hostname, vpp, l);
 	if (error) {
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 		vfs_destroy(mp);
 		printf("nfs_mountroot: mount %s failed: %d\n",
 		       mntname, error);
diff -r 28fea04e7b15 -r bb476fea44cd sys/rump/librump/rumpvfs/rumpfs.c
--- a/sys/rump/librump/rumpvfs/rumpfs.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/rump/librump/rumpvfs/rumpfs.c	Thu Mar 30 11:17:57 2017 +0200
@@ -1976,7 +1976,7 @@
 		panic("set_statvfs_info failed for rootfs: %d", error);
 
 	mp->mnt_flag &= ~MNT_RDONLY;
-	vfs_unbusy(mp, false, NULL);
+	vfs_unbusy(mp, false);
 
 	return 0;
 }
diff -r 28fea04e7b15 -r bb476fea44cd sys/sys/mount.h
--- a/sys/sys/mount.h	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/sys/mount.h	Thu Mar 30 11:17:57 2017 +0200
@@ -418,9 +418,9 @@
 bool	vfs_unmountall(struct lwp *);	    /* unmount file systems */
 bool	vfs_unmountall1(struct lwp *, bool, bool);
 bool	vfs_unmount_forceone(struct lwp *);
-int 	vfs_busy(struct mount *, struct mount **);
+int 	vfs_busy(struct mount *, int);
 int	vfs_rootmountalloc(const char *, const char *, struct mount **);
-void	vfs_unbusy(struct mount *, bool, struct mount **);
+void	vfs_unbusy(struct mount *, bool);
 int	vfs_attach(struct vfsops *);
 int	vfs_detach(struct vfsops *);
 void	vfs_reinit(void);
diff -r 28fea04e7b15 -r bb476fea44cd sys/ufs/ext2fs/ext2fs_vfsops.c
--- a/sys/ufs/ext2fs/ext2fs_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/ufs/ext2fs/ext2fs_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
@@ -279,7 +279,7 @@
 	}
 
 	if ((error = ext2fs_mountfs(rootvp, mp)) != 0) {
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 		vfs_destroy(mp);
 		return error;
 	}
@@ -288,7 +288,7 @@
 	fs = ump->um_e2fs;
 	ext2fs_sb_setmountinfo(fs, mp);
 	(void)ext2fs_statvfs(mp, &mp->mnt_stat);
-	vfs_unbusy(mp, false, NULL);
+	vfs_unbusy(mp, false);
 	setrootfstime((time_t)fs->e2fs.e2fs_wtime);
 	return 0;
 }
diff -r 28fea04e7b15 -r bb476fea44cd sys/ufs/ffs/ffs_vfsops.c
--- a/sys/ufs/ffs/ffs_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/ufs/ffs/ffs_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
@@ -377,7 +377,7 @@
 	 */
 	mp->mnt_flag |= MNT_FORCE;
 	if ((error = ffs_mountfs(rootvp, mp, l)) != 0) {
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 		vfs_destroy(mp);
 		return (error);
 	}
@@ -388,7 +388,7 @@
 	memset(fs->fs_fsmnt, 0, sizeof(fs->fs_fsmnt));
 	(void)copystr(mp->mnt_stat.f_mntonname, fs->fs_fsmnt, MNAMELEN - 1, 0);
 	(void)ffs_statvfs(mp, &mp->mnt_stat);
-	vfs_unbusy(mp, false, NULL);
+	vfs_unbusy(mp, false);
 	setrootfstime((time_t)fs->fs_time);
 	return (0);
 }
diff -r 28fea04e7b15 -r bb476fea44cd sys/ufs/lfs/lfs_bio.c
--- a/sys/ufs/lfs/lfs_bio.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/ufs/lfs/lfs_bio.c	Thu Mar 30 11:17:57 2017 +0200
@@ -536,12 +536,12 @@
 
 	if (only_onefs) {
 		KASSERT(fs != NULL);
-		if (vfs_busy(fs->lfs_ivnode->v_mount, NULL))
+		if (vfs_busy(fs->lfs_ivnode->v_mount, 0))
 			goto errout;
 		mutex_enter(&lfs_lock);
 		lfs_flush_fs(fs, flags);
 		mutex_exit(&lfs_lock);
-		vfs_unbusy(fs->lfs_ivnode->v_mount, false, NULL);
+		vfs_unbusy(fs->lfs_ivnode->v_mount, false);
 	} else {
 		locked_fakequeue_count = 0;
 		mountlist_iterator_init(&iter);
@@ -553,7 +553,7 @@
 				lfs_flush_fs(tfs, flags);
 				mutex_exit(&lfs_lock);
 			}
-			vfs_unbusy(mp, false, NULL);
+			vfs_unbusy(mp, false);
 		}
 		mountlist_iterator_destroy(iter);
 	}
diff -r 28fea04e7b15 -r bb476fea44cd sys/ufs/lfs/lfs_syscalls.c
--- a/sys/ufs/lfs/lfs_syscalls.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/ufs/lfs/lfs_syscalls.c	Thu Mar 30 11:17:57 2017 +0200
@@ -253,7 +253,7 @@
 
 	cnt = blkcnt;
 
-	if ((error = vfs_busy(mntp, NULL)) != 0)
+	if ((error = vfs_busy(mntp, 0)) != 0)
 		return (error);
 
 	/*
@@ -479,7 +479,7 @@
 
 	lfs_segunlock(fs);
 
-	vfs_unbusy(mntp, false, NULL);
+	vfs_unbusy(mntp, false);
 	if (error)
 		return (error);
 	else if (do_again)
@@ -508,7 +508,7 @@
 	}
 
 	lfs_segunlock(fs);
-	vfs_unbusy(mntp, false, NULL);
+	vfs_unbusy(mntp, false);
 	KASSERTMSG((numrefed == 0), "lfs_markv: numrefed=%d", numrefed);
 
 	return (error);
@@ -651,7 +651,7 @@
 	if ((mntp = vfs_getvfs(fsidp)) == NULL)
 		return (ENOENT);
 
-	if ((error = vfs_busy(mntp, NULL)) != 0)
+	if ((error = vfs_busy(mntp, 0)) != 0)
 		return (error);
 
 	ump = VFSTOULFS(mntp);
@@ -765,7 +765,7 @@
 
 	KASSERTMSG((numrefed == 0), "lfs_bmapv: numrefed=%d", numrefed);
 
-	vfs_unbusy(mntp, false, NULL);
+	vfs_unbusy(mntp, false);
 
 	return 0;
 }
@@ -804,7 +804,7 @@
 	fs = VFSTOULFS(mntp)->um_lfs;
 	segnum = SCARG(uap, segment);
 
-	if ((error = vfs_busy(mntp, NULL)) != 0)
+	if ((error = vfs_busy(mntp, 0)) != 0)
 		return (error);
 
 	KERNEL_LOCK(1, NULL);
@@ -812,7 +812,7 @@
 	error = lfs_do_segclean(fs, segnum);
 	lfs_segunlock(fs);
 	KERNEL_UNLOCK_ONE(NULL);
-	vfs_unbusy(mntp, false, NULL);
+	vfs_unbusy(mntp, false);
 	return error;
 }
 
diff -r 28fea04e7b15 -r bb476fea44cd sys/ufs/lfs/lfs_vfsops.c
--- a/sys/ufs/lfs/lfs_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/ufs/lfs/lfs_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
@@ -464,7 +464,7 @@
 				if (lfs_sb_getnextseg(fs) < lfs_sb_getcurseg(fs) && fs->lfs_nowrap) {
 					/* Don't try to write if we're suspended */
 					mutex_exit(&lfs_lock);
-					vfs_unbusy(mp, false, NULL);
+					vfs_unbusy(mp, false);
 					continue;
 				}
 				if (LFS_STARVED_FOR_SEGS(fs)) {
@@ -472,7 +472,7 @@
 
 					DLOG((DLOG_FLUSH, "lfs_writerd: need cleaning before writing possible\n"));
 					lfs_wakeup_cleaner(fs);
-					vfs_unbusy(mp, false, NULL);
+					vfs_unbusy(mp, false);
 					continue;
 				}
 
@@ -499,7 +499,7 @@
 				mutex_exit(&lfs_lock);
  			}
 			KASSERT(!mutex_owned(&lfs_lock));
- 			vfs_unbusy(mp, false, NULL);
+ 			vfs_unbusy(mp, false);
  		}
 		if (lfsc == 0) {
 			mutex_enter(&lfs_lock);
@@ -598,7 +598,7 @@
 		return (error);
 	}
 	if ((error = lfs_mountfs(rootvp, mp, l))) {
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 		vfs_destroy(mp);
 		return (error);
 	}
@@ -607,7 +607,7 @@
 	fs = ump->um_lfs;
 	lfs_sb_setfsmnt(fs, mp->mnt_stat.f_mntonname);
 	(void)lfs_statvfs(mp, &mp->mnt_stat);
-	vfs_unbusy(mp, false, NULL);
+	vfs_unbusy(mp, false);
 	setrootfstime((time_t)lfs_sb_gettstamp(VFSTOULFS(mp)->um_lfs));
 	return (0);
 }
diff -r 28fea04e7b15 -r bb476fea44cd sys/ufs/lfs/ulfs_vfsops.c
--- a/sys/ufs/lfs/ulfs_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/ufs/lfs/ulfs_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
@@ -113,7 +113,7 @@
 	int error;
 
 	/* Mark the mount busy, as we're passing it to kauth(9). */
-	error = vfs_busy(mp, NULL);
+	error = vfs_busy(mp, 0);
 	if (error) {
 		return (error);
 	}
@@ -122,7 +122,7 @@
 	error = lfsquota_handle_cmd(mp, l, args);
 
 	mutex_exit(&mp->mnt_updating);
-	vfs_unbusy(mp, false, NULL);
+	vfs_unbusy(mp, false);
 	return (error);
 #endif
 }
@@ -169,7 +169,7 @@
 	}
 
 	if (error) {
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 		return (error);
 	}
 
@@ -204,7 +204,7 @@
 		error = EINVAL;
 	}
 	mutex_exit(&mp->mnt_updating);
-	vfs_unbusy(mp, false, NULL);
+	vfs_unbusy(mp, false);
 	return (error);
 #endif
 
diff -r 28fea04e7b15 -r bb476fea44cd sys/ufs/mfs/mfs_vfsops.c
--- a/sys/ufs/mfs/mfs_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/ufs/mfs/mfs_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
@@ -215,7 +215,7 @@
 	mfsp->mfs_refcnt = 1;
 	bufq_alloc(&mfsp->mfs_buflist, "fcfs", 0);
 	if ((error = ffs_mountfs(rootvp, mp, l)) != 0) {
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 		bufq_free(mfsp->mfs_buflist);
 		vfs_destroy(mp);
 		kmem_free(mfsp, sizeof(*mfsp));
@@ -227,7 +227,7 @@
 	fs = ump->um_fs;
 	(void) copystr(mp->mnt_stat.f_mntonname, fs->fs_fsmnt, MNAMELEN - 1, 0);
 	(void)ffs_statvfs(mp, &mp->mnt_stat);
-	vfs_unbusy(mp, false, NULL);
+	vfs_unbusy(mp, false);
 	return (0);
 }
 
@@ -375,14 +375,14 @@
 	 * Add a reference to the mfsnode to prevent it disappearing in
 	 * this routine.
 	 */
-	if ((error = vfs_busy(mp, NULL)) != 0)
+	if ((error = vfs_busy(mp, 0)) != 0)
 		return error;
 	vp = VFSTOUFS(mp)->um_devvp;
 	mfsp = VTOMFS(vp);
 	mutex_enter(&mfs_lock);
 	mfsp->mfs_refcnt++;
 	mutex_exit(&mfs_lock);
-	vfs_unbusy(mp, false, NULL);
+	vfs_unbusy(mp, false);
 
 	base = mfsp->mfs_baseoff;
 	mutex_enter(&mfs_lock);
diff -r 28fea04e7b15 -r bb476fea44cd sys/ufs/ufs/ufs_vfsops.c
--- a/sys/ufs/ufs/ufs_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
+++ b/sys/ufs/ufs/ufs_vfsops.c	Thu Mar 30 11:17:57 2017 +0200
@@ -132,7 +132,7 @@
 	int error;
 
 	/* Mark the mount busy, as we're passing it to kauth(9). */
-	error = vfs_busy(mp, NULL);
+	error = vfs_busy(mp, 0);
 	if (error) {
 		return (error);
 	}
@@ -141,7 +141,7 @@
 	error = quota_handle_cmd(mp, l, args);
 
 	mutex_exit(&mp->mnt_updating);
-	vfs_unbusy(mp, false, NULL);
+	vfs_unbusy(mp, false);
 	return (error);
 #endif
 }
@@ -188,7 +188,7 @@
 	}
 
 	if (error) {
-		vfs_unbusy(mp, false, NULL);
+		vfs_unbusy(mp, false);
 		return (error);
 	}
 
@@ -223,7 +223,7 @@
 		error = EINVAL;
 	}
 	mutex_exit(&mp->mnt_updating);
-	vfs_unbusy(mp, false, NULL);
+	vfs_unbusy(mp, false);
 	return (error);
 #endif