HelenOS sources

VFS_MOUNT_NO_REF  183 uspace/lib/c/include/ipc/vfs.h 	VFS_MOUNT_NO_REF = 4,
VFS_MOUNT_NO_REF  183 uspace/lib/posix/include/libc/ipc/vfs.h 	VFS_MOUNT_NO_REF = 4,
HelenOS homepage, sources at GitHub