4 files changed, 22 insertions, 2 deletions

diff --git a/sys/fs/nullfs/null.h b/sys/fs/nullfs/null.h
index 17fd90203174..7bfdc20a3f67 100644
--- a/sys/fs/nullfs/null.h
+++ b/sys/fs/nullfs/null.h
@@ -39,6 +39,7 @@
 #include <vm/uma.h>
 
 #define	NULLM_CACHE		0x0001
+#define	NULLM_NOUNPBYPASS	0x0002
 
 struct null_mount {
 	struct mount	*nullm_vfs;
@@ -90,7 +91,7 @@ null_is_nullfs_vnode(struct vnode *vp)
 	const struct vop_vector *op;
 
 	op = vp->v_op;
-	return (op == &null_vnodeops);
+	return (op == &null_vnodeops || op == &null_vnodeops_no_unp_bypass);
 }
 
 extern uma_zone_t null_node_zone;
diff --git a/sys/fs/nullfs/null_subr.c b/sys/fs/nullfs/null_subr.c
index d7f847d449d0..a843ae44f121 100644
--- a/sys/fs/nullfs/null_subr.c
+++ b/sys/fs/nullfs/null_subr.c
@@ -240,7 +240,9 @@ null_nodeget(struct mount *mp, struct vnode *lowervp, struct vnode **vpp)
 	 */
 	xp = uma_zalloc_smr(null_node_zone, M_WAITOK);
 
-	error = getnewvnode("nullfs", mp, &null_vnodeops, &vp);
+	error = getnewvnode("nullfs", mp, (MOUNTTONULLMOUNT(mp)->nullm_flags &
+	    NULLM_NOUNPBYPASS) != 0 ? &null_vnodeops_no_unp_bypass :
+	    &null_vnodeops, &vp);
 	if (error) {
 		vput(lowervp);
 		uma_zfree_smr(null_node_zone, xp);
diff --git a/sys/fs/nullfs/null_vfsops.c b/sys/fs/nullfs/null_vfsops.c
index 483d4182e65e..170a3dd51cd8 100644
--- a/sys/fs/nullfs/null_vfsops.c
+++ b/sys/fs/nullfs/null_vfsops.c
@@ -87,6 +87,8 @@ nullfs_mount(struct mount *mp)
 	bool isvnunlocked;
 	static const char cache_opt_name[] = "cache";
 	static const char nocache_opt_name[] = "nocache";
+	static const char unixbypass_opt_name[] = "unixbypass";
+	static const char nounixbypass_opt_name[] = "nounixbypass";
 
 	NULLFSDEBUG("nullfs_mount(mp = %p)\n", (void *)mp);
 
@@ -222,6 +224,13 @@ nullfs_mount(struct mount *mp)
 		    &xmp->notify_node);
 	}
 
+	if (vfs_getopt(mp->mnt_optnew, unixbypass_opt_name, NULL, NULL) == 0) {
+		;
+	} else if (vfs_getopt(mp->mnt_optnew, nounixbypass_opt_name, NULL,
+	    NULL) == 0) {
+		xmp->nullm_flags |= NULLM_NOUNPBYPASS;
+	}
+
 	if (lowerrootvp == mp->mnt_vnodecovered) {
 		vn_lock(lowerrootvp, LK_EXCLUSIVE | LK_RETRY | LK_CANRECURSE);
 		lowerrootvp->v_vflag |= VV_CROSSLOCK;
diff --git a/sys/fs/nullfs/null_vnops.c b/sys/fs/nullfs/null_vnops.c
index 4b9342f43870..d4baabeb40ab 100644
--- a/sys/fs/nullfs/null_vnops.c
+++ b/sys/fs/nullfs/null_vnops.c
@@ -1256,3 +1256,11 @@ struct vop_vector null_vnodeops = {
 	.vop_copy_file_range =	VOP_PANIC,
 };
 VFS_VOP_VECTOR_REGISTER(null_vnodeops);
+
+struct vop_vector null_vnodeops_no_unp_bypass = {
+	.vop_default =		&null_vnodeops,
+	.vop_unp_bind =		vop_stdunp_bind,
+	.vop_unp_connect =	vop_stdunp_connect,
+	.vop_unp_detach =	vop_stdunp_detach,
+};
+VFS_VOP_VECTOR_REGISTER(null_vnodeops_no_unp_bypass);