Allow mounting FUSE filesystems in jails

Reviewed by:	jamie
MFC after:	2 weeks
Relnotes:	yes
Differential Revision:	https://reviews.freebsd.org/D16371

etc/defaults/devfs.rules

@@ -84,4 +84,5 @@ add path stderr unhide
 add include $devfsrules_hide_all
 add include $devfsrules_unhide_basic
 add include $devfsrules_unhide_login
+add path fuse unhide
 add path zfs unhide

sys/fs/fuse/fuse_main.c

@@ -91,7 +91,7 @@ static struct vfsconf fuse_vfsconf = {
 	.vfc_name = "fusefs",
 	.vfc_vfsops = &fuse_vfsops,
 	.vfc_typenum = -1,
-	.vfc_flags = VFCF_SYNTHETIC
+	.vfc_flags = VFCF_JAIL | VFCF_SYNTHETIC
 };
 
 SYSCTL_INT(_vfs_fuse, OID_AUTO, kernelabi_major, CTLFLAG_RD,

usr.sbin/jail/jail.8

@@ -25,7 +25,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd May 4, 2018
+.Dd July 20, 2018
 .Dt JAIL 8
 .Os
 .Sh NAME
@@ -580,6 +580,14 @@ This permission is effective only together with
 and only when
 .Va enforce_statfs
 is set to a value lower than 2.
+.It Va allow.mount.fusefs
+privileged users inside the jail will be able to mount and unmount 
+fuse-based file systems.
+This permission is effective only together with
+.Va allow.mount
+and only when
+.Va enforce_statfs
+is set to a value lower than 2.
 .It Va allow.mount.nullfs
 privileged users inside the jail will be able to mount and unmount the
 nullfs file system.