diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index 672f673..7c27ba7 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -1014,17 +1014,28 @@ int
 insmntque1(struct vnode *vp, struct mount *mp,
 	void (*dtr)(struct vnode *, void *), void *dtr_arg)
 {
+	int locked;
 
 	KASSERT(vp->v_mount == NULL,
 		("insmntque: vnode already on per mount vnode list"));
 	VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)"));
+#ifdef DEBUG_VFS_LOCKS
+	if (!VFS_NEEDSGIANT(mp))
+		ASSERT_VOP_ELOCKED(vp,
+		    "insmntque: mp-safe fs and non-locked vp");
+#endif
 	MNT_ILOCK(mp);
 	if ((mp->mnt_kern_flag & MNTK_NOINSMNTQ) != 0 &&
-	    mp->mnt_nvnodelistsize == 0) {
-		MNT_IUNLOCK(mp);
-		if (dtr != NULL)
-			dtr(vp, dtr_arg);
-		return (EBUSY);
+	    ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 ||
+	     mp->mnt_nvnodelistsize == 0)) {
+		locked = VOP_ISLOCKED(vp);
+		if (!locked || (locked == LK_EXCLUSIVE &&
+		     !(vp->v_vflag & VV_FORCEINSMQ))) {
+			MNT_IUNLOCK(mp);
+			if (dtr != NULL)
+				dtr(vp, dtr_arg);
+			return (EBUSY);
+		}
 	}
 	vp->v_mount = mp;
 	MNT_REF(mp);
@@ -3140,9 +3151,13 @@ vfs_allocate_syncvnode(struct mount *mp)
 		return (error);
 	}
 	vp->v_type = VNON;
+	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
+	vp->v_vflag |= VV_FORCEINSMQ;
 	error = insmntque(vp, mp);
 	if (error != 0)
 		panic("vfs_allocate_syncvnode: insmntque failed");
+	vp->v_vflag &= ~VV_FORCEINSMQ;
+	VOP_UNLOCK(vp, 0);
 	/*
 	 * Place the vnode onto the syncer worklist. We attempt to
 	 * scatter them about on the list so that they will go off
diff --git a/sys/sys/vnode.h b/sys/sys/vnode.h
index 0d191e3..5591615 100644
--- a/sys/sys/vnode.h
+++ b/sys/sys/vnode.h
@@ -248,6 +248,7 @@ struct xvnode {
 #define	VV_NOKNOTE	0x0200	/* don't activate knotes on this vnode */
 #define	VV_DELETED	0x0400	/* should be removed */
 #define	VV_MD		0x0800	/* vnode backs the md device */
+#define	VV_FORCEINSMQ	0x1000	/* force the insmntque to succeed */
 
 /*
  * Vnode attributes.  A field value of VNOVAL represents a field whose value
diff --git a/sys/ufs/ffs/ffs_extern.h b/sys/ufs/ffs/ffs_extern.h
index a496542..3c8d323 100644
--- a/sys/ufs/ffs/ffs_extern.h
+++ b/sys/ufs/ffs/ffs_extern.h
@@ -87,6 +87,9 @@ int	ffs_valloc(struct vnode *, int, struct ucred *, struct vnode **);
 
 int	ffs_vfree(struct vnode *, ino_t, int);
 vfs_vget_t ffs_vget;
+int	ffs_vgetf(struct mount *, ino_t, int, struct vnode **, int);
+
+#define	FFSV_FORCEINSMQ	0x0001
 
 extern struct vop_vector ffs_vnodeops1;
 extern struct vop_vector ffs_fifoops1;
diff --git a/sys/ufs/ffs/ffs_softdep.c b/sys/ufs/ffs/ffs_softdep.c
index 657d46c..a3a76ea 100644
--- a/sys/ufs/ffs/ffs_softdep.c
+++ b/sys/ufs/ffs/ffs_softdep.c
@@ -912,8 +912,8 @@ process_worklist_item(mp, flags)
 		wk->wk_state |= INPROGRESS;
 		ump->softdep_on_worklist_inprogress++;
 		FREE_LOCK(&lk);
-		ffs_vget(mp, WK_DIRREM(wk)->dm_oldinum,
-		    LK_NOWAIT | LK_EXCLUSIVE, &vp);
+		ffs_vgetf(mp, WK_DIRREM(wk)->dm_oldinum,
+		    LK_NOWAIT | LK_EXCLUSIVE, &vp, FFSV_FORCEINSMQ);
 		ACQUIRE_LOCK(&lk);
 		wk->wk_state &= ~INPROGRESS;
 		ump->softdep_on_worklist_inprogress--;
@@ -1067,8 +1067,11 @@ softdep_flushfiles(oldmnt, flags, td)
 	int flags;
 	struct thread *td;
 {
-	int error, count, loopcnt;
+	int error, count, loopcnt, retry_flush_count, retry;
 
+	loopcnt = 10;
+	retry_flush_count = 3;
+retry_flush:
 	error = 0;
 
 	/*
@@ -1077,7 +1080,7 @@ softdep_flushfiles(oldmnt, flags, td)
 	 * creates. In theory, this loop can happen at most twice,
 	 * but we give it a few extra just to be sure.
 	 */
-	for (loopcnt = 10; loopcnt > 0; loopcnt--) {
+	for (; loopcnt > 0; loopcnt--) {
 		/*
 		 * Do another flush in case any vnodes were brought in
 		 * as part of the cleanup operations.
@@ -1100,6 +1103,24 @@ softdep_flushfiles(oldmnt, flags, td)
 	}
 	if (!error)
 		error = softdep_waitidle(oldmnt);
+	if (!error) {
+		if (oldmnt->mnt_kern_flag & MNTK_UNMOUNT) {
+			retry = 0;
+			MNT_ILOCK(oldmnt);
+			KASSERT((oldmnt->mnt_kern_flag & MNTK_NOINSMNTQ) != 0,
+			    ("softdep_flushfiles: !MNTK_NOINSMNTQ"));
+			if (oldmnt->mnt_nvnodelistsize > 0) {
+				if (--retry_flush_count > 0) {
+					retry = 1;
+					loopcnt = 3;
+				} else
+					error = EBUSY;
+			}
+			MNT_IUNLOCK(oldmnt);
+			if (retry)
+				goto retry_flush;
+		}
+	}
 	return (error);
 }
 
@@ -2769,8 +2790,9 @@ handle_workitem_freeblocks(freeblks, flags)
 	 */
 	if (freeblks->fb_chkcnt != blocksreleased &&
 	    (fs->fs_flags & FS_UNCLEAN) != 0 &&
-	    ffs_vget(freeblks->fb_list.wk_mp, freeblks->fb_previousinum,
-	    (flags & LK_NOWAIT) | LK_EXCLUSIVE, &vp) == 0) {
+	    ffs_vgetf(freeblks->fb_list.wk_mp, freeblks->fb_previousinum,
+		(flags & LK_NOWAIT) | LK_EXCLUSIVE, &vp, FFSV_FORCEINSMQ)
+	    == 0) {
 		ip = VTOI(vp);
 		DIP_SET(ip, i_blocks, DIP(ip, i_blocks) + \
 		    freeblks->fb_chkcnt - blocksreleased);
@@ -3557,8 +3579,8 @@ handle_workitem_remove(dirrem, xp)
 	int error;
 
 	if ((vp = xp) == NULL &&
-	    (error = ffs_vget(dirrem->dm_list.wk_mp,
-	    dirrem->dm_oldinum, LK_EXCLUSIVE, &vp)) != 0) {
+	    (error = ffs_vgetf(dirrem->dm_list.wk_mp,
+		    dirrem->dm_oldinum, LK_EXCLUSIVE, &vp, FFSV_FORCEINSMQ)) != 0) {
 		softdep_error("handle_workitem_remove: vget", error);
 		return;
 	}
@@ -5073,9 +5095,11 @@ softdep_fsync(vp)
 		 * for details on possible races.
 		 */
 		FREE_LOCK(&lk);
-		if (ffs_vget(mp, parentino, LK_NOWAIT | LK_EXCLUSIVE, &pvp)) {
+		if (ffs_vgetf(mp, parentino, LK_NOWAIT | LK_EXCLUSIVE, &pvp,
+		    FFSV_FORCEINSMQ)) {
 			VOP_UNLOCK(vp, 0);
-			error = ffs_vget(mp, parentino, LK_EXCLUSIVE, &pvp);
+			error = ffs_vgetf(mp, parentino, LK_EXCLUSIVE,
+			    &pvp, FFSV_FORCEINSMQ);
 			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 			if (error != 0)
 				return (error);
@@ -5580,7 +5604,8 @@ flush_pagedep_deps(pvp, mp, diraddhdp)
 		inum = dap->da_newinum;
 		if (dap->da_state & MKDIR_BODY) {
 			FREE_LOCK(&lk);
-			if ((error = ffs_vget(mp, inum, LK_EXCLUSIVE, &vp)))
+			if ((error = ffs_vgetf(mp, inum, LK_EXCLUSIVE, &vp,
+			    FFSV_FORCEINSMQ)))
 				break;
 			if ((error=ffs_syncvnode(vp, MNT_NOWAIT)) ||
 			    (error=ffs_syncvnode(vp, MNT_NOWAIT))) {
@@ -5920,7 +5945,8 @@ clear_remove(td)
 			if (vn_start_write(NULL, &mp, V_NOWAIT) != 0)
 				continue;
 			FREE_LOCK(&lk);
-			if ((error = ffs_vget(mp, ino, LK_EXCLUSIVE, &vp))) {
+			if ((error = ffs_vgetf(mp, ino, LK_EXCLUSIVE, &vp,
+			     FFSV_FORCEINSMQ))) {
 				softdep_error("clear_remove: vget", error);
 				vn_finished_write(mp);
 				ACQUIRE_LOCK(&lk);
@@ -5992,7 +6018,8 @@ clear_inodedeps(td)
 		if (vn_start_write(NULL, &mp, V_NOWAIT) != 0)
 			continue;
 		FREE_LOCK(&lk);
-		if ((error = ffs_vget(mp, ino, LK_EXCLUSIVE, &vp)) != 0) {
+		if ((error = ffs_vgetf(mp, ino, LK_EXCLUSIVE, &vp,
+		    FFSV_FORCEINSMQ)) != 0) {
 			softdep_error("clear_inodedeps: vget", error);
 			vn_finished_write(mp);
 			ACQUIRE_LOCK(&lk);
diff --git a/sys/ufs/ffs/ffs_vfsops.c b/sys/ufs/ffs/ffs_vfsops.c
index 003e97f..af284b6 100644
--- a/sys/ufs/ffs/ffs_vfsops.c
+++ b/sys/ufs/ffs/ffs_vfsops.c
@@ -1310,6 +1310,17 @@ ffs_vget(mp, ino, flags, vpp)
 	int flags;
 	struct vnode **vpp;
 {
+	return (ffs_vgetf(mp, ino, flags, vpp, 0));
+}
+
+int
+ffs_vgetf(mp, ino, flags, vpp, ffs_flags)
+	struct mount *mp;
+	ino_t ino;
+	int flags;
+	struct vnode **vpp;
+	int ffs_flags;
+{
 	struct fs *fs;
 	struct inode *ip;
 	struct ufsmount *ump;
@@ -1384,12 +1395,15 @@ ffs_vget(mp, ino, flags, vpp)
 
 	td = curthread;
 	lockmgr(vp->v_vnlock, LK_EXCLUSIVE, NULL);
+	if (ffs_flags & FFSV_FORCEINSMQ)
+		vp->v_vflag |= VV_FORCEINSMQ;
 	error = insmntque(vp, mp);
 	if (error != 0) {
 		uma_zfree(uma_inode, ip);
 		*vpp = NULL;
 		return (error);
 	}
+	vp->v_vflag &= ~VV_FORCEINSMQ;
 	error = vfs_hash_insert(vp, ino, flags, td, vpp, NULL, NULL);
 	if (error || *vpp != NULL)
 		return (error);