[LTP] [PATCH v1 1/4] lib: add new cgroup test API

[Jan Stancek <jstancek@redhat.com>]

----- Original Message -----
> +
> +static void tst_cgroup1_umount(const char *mnt_path, const char *new_path)
> +{
> +	FILE *fp;
> +	int fd;
> +	char s_new[BUFSIZ], s[BUFSIZ], value[BUFSIZ];
> +
> +	if (!tst_is_mounted(mnt_path))
> +		return;
> +
> +	/* Move all processes in task to its parent node. */
> +	sprintf(s, "%s/tasks", mnt_path);
> +	fd = open(s, O_WRONLY);
> +	if (fd == -1)
> +		tst_res(TWARN | TERRNO, "open %s", s);
> +
> +	snprintf(s_new, BUFSIZ, "%s/tasks", new_path);
> +	fp = fopen(s_new, "r");
> +	if (fp == NULL)
> +		tst_res(TWARN | TERRNO, "fopen %s", s_new);
> +	if ((fd != -1) && (fp != NULL)) {
> +		while (fgets(value, BUFSIZ, fp) != NULL)
> +			if (write(fd, value, strlen(value) - 1)
> +			    != (ssize_t)strlen(value) - 1)
> +				tst_res(TWARN | TERRNO, "write %s", s);
> +	}
> +	if (fd != -1)
> +		close(fd);
> +	if (fp != NULL)
> +		fclose(fp);
> +	if (rmdir(new_path) == -1)
> +		tst_res(TWARN | TERRNO, "rmdir %s", new_path);
> +	if (umount(mnt_path) == -1)
> +		tst_res(TWARN | TERRNO, "umount %s", mnt_path);
> +	if (rmdir(mnt_path) == -1)
> +		tst_res(TWARN | TERRNO, "rmdir %s", mnt_path);

This sequence looks almost identical to tst_cgroup2_umount(),
would be nice if code could be shared in some way.