diff --git a/man/tmpfiles.d.xml b/man/tmpfiles.d.xml index ef0bb1f7f8..495315d55c 100644 --- a/man/tmpfiles.d.xml +++ b/man/tmpfiles.d.xml @@ -661,6 +661,14 @@ d /tmp/foo/bar - - - bmA:1h - Applications may use this to temporarily exclude certain directory subtrees from the aging algorithm: the applications can take a BSD file lock themselves, and as long as they keep it aging of the directory/file and everything below it is disabled. + + This behavior can be used to ensure guaranteed cleanup of files or directories whose lifetime + should be aligned with the process that created them by having that process create them in a location + monitored by systemd-tmpfiles with an age of 0, and having the + process immediately lock the directory or file before using it. Because the BSD lock is process + specific, the file is guaranteed to be unlocked as soon as the process exits, meaning that even if the + process crashes, those files and directories will be unlocked and cleaned up by + systemd-tmpfiles.