Index: share/man/man5/devfs.5
===================================================================
--- share/man/man5/devfs.5	(revision 231065)
+++ share/man/man5/devfs.5	(working copy)
@@ -90,6 +90,29 @@ and
 .Pa 2 .
 .Xr fdescfs 5
 creates files for all open descriptors.
+.Pp
+The options are as follows:
+.Bl -tag -width indent
+.It Fl o Ar options
+Use the specified mount
+.Ar options ,
+as described in
+.Xr mount 8 .
+The following devfs file system-specific options are available:
+.Bl -tag -width indent
+.It Cm ruleset Ns No = Ns Ar ruleset
+Set ruleset number
+.Ar ruleset
+as the current ruleset for the mount-point and apply all its rules. If the
+ruleset number
+.Ar ruleset
+does not exist, an empty ruleset with the number
+.Ar ruleset
+is created. See
+.Xr devfs 8
+for more information on working with devfs rulesets.
+.El
+.El
 .Sh FILES
 .Bl -tag -width /dev/XXXX -compact
 .It Pa /dev
Index: sys/fs/devfs/devfs_rule.c
===================================================================
--- sys/fs/devfs/devfs_rule.c	(revision 231065)
+++ sys/fs/devfs/devfs_rule.c	(working copy)
@@ -771,3 +771,17 @@ devfs_rules_cleanup(struct devfs_mount *dm)
 		devfs_ruleset_reap(ds);
 	}
 }
+
+/*
+ * Make rsnum the active ruleset for dm (locked)
+ */
+void
+devfs_ruleset_set(devfs_rsnum rsnum, struct devfs_mount *dm)
+{
+
+	sx_assert(&dm->dm_lock, SX_XLOCKED);
+
+	sx_xlock(&sx_rules);
+	devfs_ruleset_use(rsnum, dm);
+	sx_xunlock(&sx_rules);
+}
Index: sys/fs/devfs/devfs_vfsops.c
===================================================================
--- sys/fs/devfs/devfs_vfsops.c	(revision 231065)
+++ sys/fs/devfs/devfs_vfsops.c	(working copy)
@@ -65,6 +65,7 @@ devfs_mount(struct mount *mp)
 	int error;
 	struct devfs_mount *fmp;
 	struct vnode *rvp;
+	devfs_rsnum rsnum;
 
 	if (devfs_unr == NULL)
 		devfs_unr = new_unrhdr(0, INT_MAX, NULL);
@@ -74,6 +75,18 @@ devfs_mount(struct mount *mp)
 	if (mp->mnt_flag & (MNT_UPDATE | MNT_ROOTFS))
 		return (EOPNOTSUPP);
 
+	rsnum = 0;
+
+	if (mp->mnt_optnew != NULL &&
+	    vfs_getopt(mp->mnt_optnew, "ruleset", NULL, NULL) == 0) {
+		if (vfs_scanopt(mp->mnt_optnew, "ruleset", "%d",
+		    &rsnum) != 1) {
+			vfs_mount_error(mp, "%s",
+			    "invalid ruleset specification");
+			return (EINVAL);
+		}
+	}
+
 	fmp = malloc(sizeof *fmp, M_DEVFS, M_WAITOK | M_ZERO);
 	fmp->dm_idx = alloc_unr(devfs_unr);
 	sx_init(&fmp->dm_lock, "devfsmount");
@@ -101,6 +114,12 @@ devfs_mount(struct mount *mp)
 		return (error);
 	}
 
+	if (rsnum != 0) {
+		sx_xlock(&fmp->dm_lock);
+		devfs_ruleset_set(rsnum, fmp);
+		sx_xunlock(&fmp->dm_lock);
+	}
+
 	VOP_UNLOCK(rvp, 0);
 
 	vfs_mountedfrom(mp, "devfs");
Index: sys/fs/devfs/devfs.h
===================================================================
--- sys/fs/devfs/devfs.h	(revision 231065)
+++ sys/fs/devfs/devfs.h	(working copy)
@@ -182,6 +182,7 @@ void	devfs_rules_apply(struct devfs_mount *, struc
 void	devfs_rules_cleanup(struct devfs_mount *);
 int	devfs_rules_ioctl(struct devfs_mount *, u_long, caddr_t,
 	    struct thread *);
+void	devfs_ruleset_set(devfs_rsnum rsnum, struct devfs_mount *dm);
 int	devfs_allocv(struct devfs_dirent *, struct mount *, int,
 	    struct vnode **);
 char	*devfs_fqpn(char *, struct devfs_mount *, struct devfs_dirent *,