example3-bind-mount.c

#include "common.h"


int main(void) {
    printpid();
    char source_dir[255] = "bind-source/";
	addcurpath(source_dir);
	char target_dir[255] = "bind-target/";
	addcurpath(target_dir);

	wait("* Step 1: Will do a mount_tree() on the existing directory %s", source_dir);
    int source_fd = open_tree(0, source_dir, OPEN_TREE_CLONE);
    if (source_fd < 0) {
        perror("open_tree failed");
        return 1;
    }
	printf("open_tree successful. Source dir fd = %d\n", source_fd);


    wait("* Step 2: make the bind-mount visible with move_mount");
    if (move_mount(source_fd, "", AT_FDCWD, target_dir, MOVE_MOUNT_F_EMPTY_PATH)) {
        perror("move_mount");
        return 1;
    }
    printf("bind mount is now visible at %s. Don't forget to umount!\n", target_dir);

	wait("Press ENTER to finish the program");
    close(source_fd);
    return 0;
}