mkdirat_errno_wrapper(x,y,z) is identical to RET_NERRNO(mkdirat(x, y, z)). Let's always use the latter when we can, because easier to read, shorter. The only reason to have mkdirat_errno_wrapper() at all is so that we can pass a function pointer to it around. Otherwise, let's not use it.
System and Service Manager
Details
Most documentation is available on systemd's web site.
Assorted, older, general information about systemd can be found in the systemd Wiki.
Information about build requirements is provided in the README file.
Consult our NEWS file for information about what's new in the most recent systemd versions.
Please see the Code Map for information about this repository's layout and content.
Please see the Hacking guide for information on how to hack on systemd and test your modifications.
Please see our Contribution Guidelines for more information about filing GitHub Issues and posting GitHub Pull Requests.
When preparing patches for systemd, please follow our Coding Style Guidelines.
If you are looking for support, please contact our mailing list or join our IRC channel.
Stable branches with backported patches are available in the stable repo.