loop-delete.c

/*BINFMTC: -Wall
 */

#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>

#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <linux/loop.h>

int main(int argc, char **argv) {
  if (argc != 2) {
    fprintf(stderr, "Usage: %s <loop-index>\n", argv[0]);
    return 0;
  }
  int li = atoi(argv[1]);
  int fd = open("/dev/loop-control", O_RDWR);
  ioctl(fd, LOOP_CTL_REMOVE, li);
  close(fd);
}