test_ioctl.c

#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <linux/fs.h>

enum test_type {
        IOC_VERSION = 1,
        IOC_FLAGS,
};

static int test_ioctl(const char *path, enum test_type test, int arg)
{
        int fd;
        int err;
        int SET;
        int GET;

        switch (test) {
        case IOC_VERSION:
                SET = FS_IOC_SETVERSION;
                GET = FS_IOC_GETVERSION;
                break;
        case IOC_FLAGS:
                SET = FS_IOC_SETFLAGS;
                GET = FS_IOC_GETFLAGS;
                break;
        default:
                printf("BOOOO\n");
                return -1;
        }

        if ((fd = open(path, O_RDWR)) < 0) {
                perror("open : ");
                return -1;
        }

        if ((err = ioctl(fd, SET, &arg)) < 0) {
                perror("ioctl : ");
                goto close_fd;
        }

        printf("set = %d\n", arg);

        if ((err = ioctl(fd, GET, &arg)) < 0) {
                perror("ioctl : ");
                goto close_fd;
        }

        printf("get = %d\n", arg);

close_fd:
        if ((err = close(fd)) < 0)
                perror("close : ");

        return err;
}

int main(int argc, char *argv[])
{
        char *path;

        if (argc != 2) {
                fprintf(stderr, "usage: %s path\n", argv[0]);
                return -1;
        }

        path = argv[1];

        return test_ioctl(path, IOC_FLAGS, FS_IMMUTABLE_FL);
}