diff --git a/lib/libstand/open.c b/lib/libstand/open.c
index 49dc6608ff43..0d90433800a2 100644
--- a/lib/libstand/open.c
+++ b/lib/libstand/open.c
@@ -65,6 +65,8 @@ __FBSDID("$FreeBSD$");
 
 #include "stand.h"
 
+struct fs_ops *exclusive_file_system;
+
 struct open_file files[SOPEN_MAX];
 
 static int
@@ -89,6 +91,7 @@ o_rainit(struct open_file *f)
 int
 open(const char *fname, int mode)
 {
+    struct fs_ops	*fs;
     struct open_file	*f;
     int			fd, i, error, besterror;
     const char		*file;
@@ -105,6 +108,15 @@ open(const char *fname, int mode)
     f->f_offset = 0;
     f->f_devdata = NULL;
     file = (char *)0;
+
+    if (exclusive_file_system != NULL) {
+	fs = exclusive_file_system;
+	error = (fs->fo_open)(fname, f);
+	if (error == 0)
+	    goto ok;
+	goto fail;
+    }
+
     error = devopen(f, fname, &file);
     if (error ||
 	(((f->f_flags & F_NODEV) == 0) && f->f_dev == (struct devsw *)0))
@@ -120,20 +132,17 @@ open(const char *fname, int mode)
     /* pass file name to the different filesystem open routines */
     besterror = ENOENT;
     for (i = 0; file_system[i] != NULL; i++) {
-
-	error = ((*file_system[i]).fo_open)(file, f);
-	if (error == 0) {
-	    
-	    f->f_ops = file_system[i];
-	    o_rainit(f);
-	    return (fd);
-	}
+	fs = file_system[i];
+	error = (fs->fo_open)(file, f);
+	if (error == 0)
+	    goto ok;
 	if (error != EINVAL)
 	    besterror = error;
     }
     error = besterror;
 
-    if ((f->f_flags & F_NODEV) == 0)
+ fail:
+    if ((f->f_flags & F_NODEV) == 0 && f->f_dev != NULL)
 	f->f_dev->dv_close(f);
     if (error)
 	devclose(f);
@@ -142,4 +151,9 @@ open(const char *fname, int mode)
     f->f_flags = 0;
     errno = error;
     return (-1);
+
+ ok:
+    f->f_ops = fs;
+    o_rainit(f);
+    return (fd);
 }
diff --git a/lib/libstand/stand.h b/lib/libstand/stand.h
index 28087226a526..6c7e12d4ff11 100644
--- a/lib/libstand/stand.h
+++ b/lib/libstand/stand.h
@@ -364,6 +364,7 @@ extern int		devopen(struct open_file *, const char *, const char **);
 extern int		devclose(struct open_file *f);
 extern void		panic(const char *, ...) __dead2 __printflike(1, 2);
 extern struct fs_ops	*file_system[];
+extern struct fs_ops	*exclusive_file_system;
 extern struct devsw	*devsw[];
 
 /*