sample code to show the behaviour

sandbox-poc.c (text/plain), 545 bytes, created by Xake on 2010-10-27 19:21:15 UTC

#include <fcntl.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>

int
main(){
	int fd;
	int i;
	if ((i = mkdir("one",0777)) != 0)
	{
		printf("Failed create \"one\": %d, %s\n",i,strerror(errno));
		return 1;
	}

	fd = open("one",(O_DIRECTORY | O_NOFOLLOW));
	printf("Have created and open dir \"one\"\nAbout to create dir \"one/one\"...\n");
	if ((i = mkdirat(fd,"one",0777)) != 0)
	{
		printf("Failed create \"one/one\": %d, %s\n",i,strerror(errno));
		close(fd);
		return 1;
	}

	printf("Have created \"one/one\"\n");
	return 0;
}