clone_mnt
p = clone_mnt(real_mount(path->mnt), path->dentry, CL_PRIVATE);
res = dst_mnt = clone_mnt(src_root, dentry, flag);
dst_mnt = clone_mnt(src_mnt, src_mnt->mnt.mnt_root, flag);
new_mnt = clone_mnt(old_mnt, path->dentry, CL_PRIVATE);
return clone_mnt(old, old_path->dentry, copy_flags);
mp->parent = clone_mnt(real_mount(path->mnt), dentry, copy_flags);