[systemd-devel] [PATCH] core: reuse the same /tmp and /var/tmp

[Michal Schmidt]

On 02/01/2013 04:09 PM, Michal Sekletar wrote:
> All Execs within the service, will get mounted the same /tmp and /var/tmp
> directories, if service is configured with PrivateTmp=yes. Temporary
> directories are cleaned up by service itself, rather than relying on
> systemd-tmpfiles.

Thank you taking on this long-standing issue. The general approach looks 
good to me.

...
>
> +int setup_tmpdirs(ExecContext *context) {
> +        int r = 0;
> +        bool remove_tmp = false, remove_var_tmp = false;
> +        mode_t u;
> +        char *d = NULL;
> +        char tmp_dir[] = "/tmp/systemd-private-XXXXXX",
> +             var_tmp_dir[] = "/var/tmp/systemd-private-XXXXXX";
> +
> +        assert(context);
> +
> +        if (!context->tmp_dir) {
> +                d = mktemp(tmp_dir);
> +                if (!d) {
> +                        r = -errno;
> +                        goto fail;
> +                }
> +
> +                context->tmp_dir = strdup(d);
> +                if (!context->tmp_dir) {
> +                        r = log_oom();
> +                        goto fail;
> +                }
> +
> +                u = umask(0000);
> +                r = mkdir(tmp_dir, 0777);
> +                umask(u);
> +                if (r < 0) {

Suppose that a mkdir failure happens...

> +                        r = -errno;
> +                        goto fail;
> +                }
> +                remove_tmp = true;
> +
> +                if (chmod(tmp_dir, 0777 | S_ISVTX) < 0) {
> +                        r = -errno;
> +                        goto fail;
> +                }
> +        }
[...]

... remove_tmp is still false, so this code won't free and reset 
context->tmp_dir:

 > +fail:
> +        if (remove_tmp) {
> +                free(context->tmp_dir);
> +                context->tmp_dir = NULL;
> +                rmdir(tmp_dir);
> +        }