diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c
index 72c22dc..7f3f7a1 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c
@@ -2025,6 +2025,8 @@ zfs_vget(vfs_t *vfsp, ino_t ino, int flags, vnode_t **vpp)
 		err = zfs_vnode_lock(*vpp, flags);
 	if (err != 0)
 		*vpp = NULL;
+	else
+		(*vpp)->v_hash = ino;
 	return (err);
 }
 
diff --git a/sys/fs/nullfs/null_subr.c b/sys/fs/nullfs/null_subr.c
index 0b72249..90e56ea 100644
--- a/sys/fs/nullfs/null_subr.c
+++ b/sys/fs/nullfs/null_subr.c
@@ -46,9 +46,6 @@
 
 #include <fs/nullfs/null.h>
 
-#define LOG2_SIZEVNODE 8		/* log2(sizeof struct vnode) */
-#define	NNULLNODECACHE 16
-
 /*
  * Null layer cache:
  * Each cache entry holds a reference to the lower vnode
@@ -57,12 +54,11 @@
  * alias is removed the lower vnode is vrele'd.
  */
 
-#define	NULL_NHASH(vp) \
-	(&null_node_hashtbl[(((uintptr_t)vp)>>LOG2_SIZEVNODE) & null_node_hash])
+#define	NULL_NHASH(vp) (&null_node_hashtbl[vfs_hash_index(vp) & null_hash_mask])
 
 static LIST_HEAD(null_node_hashhead, null_node) *null_node_hashtbl;
-static u_long null_node_hash;
-struct mtx null_hashmtx;
+static struct mtx null_hashmtx;
+static u_long null_hash_mask;
 
 static MALLOC_DEFINE(M_NULLFSHASH, "nullfs_hash", "NULLFS hash table");
 MALLOC_DEFINE(M_NULLFSNODE, "nullfs_node", "NULLFS vnode private part");
@@ -77,8 +73,8 @@ nullfs_init(vfsp)
 	struct vfsconf *vfsp;
 {
 
-	NULLFSDEBUG("nullfs_init\n");		/* printed during system boot */
-	null_node_hashtbl = hashinit(NNULLNODECACHE, M_NULLFSHASH, &null_node_hash);
+	null_node_hashtbl = hashinit(desiredvnodes, M_NULLFSHASH,
+	    &null_hash_mask);
 	mtx_init(&null_hashmtx, "nullhs", NULL, MTX_DEF);
 	return (0);
 }
@@ -89,7 +85,7 @@ nullfs_uninit(vfsp)
 {
 
 	mtx_destroy(&null_hashmtx);
-	hashdestroy(null_node_hashtbl, M_NULLFSHASH, null_node_hash);
+	hashdestroy(null_node_hashtbl, M_NULLFSHASH, null_hash_mask);
 	return (0);
 }
 
diff --git a/sys/kern/vfs_hash.c b/sys/kern/vfs_hash.c
index aad22e0..0271e49 100644
--- a/sys/kern/vfs_hash.c
+++ b/sys/kern/vfs_hash.c
@@ -54,11 +54,18 @@ vfs_hashinit(void *dummy __unused)
 /* Must be SI_ORDER_SECOND so desiredvnodes is available */
 SYSINIT(vfs_hash, SI_SUB_VFS, SI_ORDER_SECOND, vfs_hashinit, NULL);
 
+u_int
+vfs_hash_index(struct vnode *vp)
+{
+
+	return (vp->v_hash + vp->v_mount->mnt_hashseed);
+}
+
 static struct vfs_hash_head *
-vfs_hash_index(const struct mount *mp, u_int hash)
+vfs_hash_bucket(const struct mount *mp, u_int hash)
 {
 
-	return(&vfs_hash_tbl[(hash + mp->mnt_hashseed) & vfs_hash_mask]);
+	return (&vfs_hash_tbl[(hash + mp->mnt_hashseed) & vfs_hash_mask]);
 }
 
 int
@@ -69,7 +76,7 @@ vfs_hash_get(const struct mount *mp, u_int hash, int flags, struct thread *td, s
 
 	while (1) {
 		mtx_lock(&vfs_hash_mtx);
-		LIST_FOREACH(vp, vfs_hash_index(mp, hash), v_hashlist) {
+		LIST_FOREACH(vp, vfs_hash_bucket(mp, hash), v_hashlist) {
 			if (vp->v_hash != hash)
 				continue;
 			if (vp->v_mount != mp)
@@ -113,7 +120,7 @@ vfs_hash_insert(struct vnode *vp, u_int hash, int flags, struct thread *td, stru
 	while (1) {
 		mtx_lock(&vfs_hash_mtx);
 		LIST_FOREACH(vp2,
-		    vfs_hash_index(vp->v_mount, hash), v_hashlist) {
+		    vfs_hash_bucket(vp->v_mount, hash), v_hashlist) {
 			if (vp2->v_hash != hash)
 				continue;
 			if (vp2->v_mount != vp->v_mount)
@@ -138,7 +145,7 @@ vfs_hash_insert(struct vnode *vp, u_int hash, int flags, struct thread *td, stru
 			
 	}
 	vp->v_hash = hash;
-	LIST_INSERT_HEAD(vfs_hash_index(vp->v_mount, hash), vp, v_hashlist);
+	LIST_INSERT_HEAD(vfs_hash_bucket(vp->v_mount, hash), vp, v_hashlist);
 	mtx_unlock(&vfs_hash_mtx);
 	return (0);
 }
@@ -149,7 +156,7 @@ vfs_hash_rehash(struct vnode *vp, u_int hash)
 
 	mtx_lock(&vfs_hash_mtx);
 	LIST_REMOVE(vp, v_hashlist);
-	LIST_INSERT_HEAD(vfs_hash_index(vp->v_mount, hash), vp, v_hashlist);
+	LIST_INSERT_HEAD(vfs_hash_bucket(vp->v_mount, hash), vp, v_hashlist);
 	vp->v_hash = hash;
 	mtx_unlock(&vfs_hash_mtx);
 }
diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index 7c243b6..0bdaf36 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -279,6 +279,7 @@ SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW,
 #define VSHOULDFREE(vp) (!((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt)
 #define VSHOULDBUSY(vp) (((vp)->v_iflag & VI_FREE) && (vp)->v_holdcnt)
 
+static int vnsz2log;
 
 /*
  * Initialize the vnode management data structures.
@@ -293,6 +294,7 @@ SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW,
 static void
 vntblinit(void *dummy __unused)
 {
+	u_int i;
 	int physvnodes, virtvnodes;
 
 	/*
@@ -332,6 +334,9 @@ vntblinit(void *dummy __unused)
 	syncer_maxdelay = syncer_mask + 1;
 	mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF);
 	cv_init(&sync_wakeup, "syncer");
+	for (i = 1; i <= sizeof(struct vnode); i <<= 1)
+		vnsz2log++;
+	vnsz2log--;
 }
 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL);
 
@@ -1067,6 +1072,14 @@ alloc:
 	}
 	rangelock_init(&vp->v_rl);
 
+	/*
+	 * For the filesystems which do not use vfs_hash_insert(),
+	 * still initialize v_hash to have vfs_hash_index() useful.
+	 * E.g., nullfs uses vfs_hash_index() on the lower vnode for
+	 * its own hashing.
+	 */
+	vp->v_hash = (uintptr_t)vp >> vnsz2log;
+
 	*vpp = vp;
 	return (0);
 }
diff --git a/sys/sys/vnode.h b/sys/sys/vnode.h
index f841f82..b54dc04 100644
--- a/sys/sys/vnode.h
+++ b/sys/sys/vnode.h
@@ -812,6 +814,7 @@ int	fifo_printinfo(struct vnode *);
 typedef int vfs_hash_cmp_t(struct vnode *vp, void *arg);
 
 int vfs_hash_get(const struct mount *mp, u_int hash, int flags, struct thread *td, struct vnode **vpp, vfs_hash_cmp_t *fn, void *arg);
+u_int vfs_hash_index(struct vnode *vp);
 int vfs_hash_insert(struct vnode *vp, u_int hash, int flags, struct thread *td, struct vnode **vpp, vfs_hash_cmp_t *fn, void *arg);
 void vfs_hash_rehash(struct vnode *vp, u_int hash);
 void vfs_hash_remove(struct vnode *vp);