Hello all, I rarely post. Please be gentle. I am making an event driven free space monitoring utility. The core idea of the design is to use fanotify to listen for the existence of events which can increase space consumption, and when this happens check the remaining free space. Extra functionality to make this not face meltingly stupid are planned before I suggest anyone use it, don't worry. I am using the documentation here: https://man7.org/linux/man-pages/man7/fanotify.7.html https://man7.org/linux/man-pages/man2/fanotify_init.2.html https://man7.org/linux/man-pages/man2/fanotify_mark.2.html ```Causes problem int f_notify = fanotify_init(FAN_CLASS_NOTIF, 0); ``` ```No problem int f_notify = fanotify_init(FAN_CLASS_NOTIF | FAN_REPORT_DFID_NAME, 0); ``` ```Where it manifests if( fanotify_mark(f_notify, FAN_MARK_ADD | FAN_MARK_ONLYDIR, FAN_CREATE , AT_FDCWD, mnt) == -1 ){...} ``` The documentation for fanotify_init() states that no flags are required in the first argument. However, doing so using the code example in the first link to documentation results in an error, with errno being set to EINVAL. However, when an additional flag gets added to fanotify_init() outside the top three flags for control, there is no error. For my use case, it seems unnecessary to add additional flags and have additional work done that I'll never use but that leads me to believe that this is a kernel bug and I'm not prepared to delve into that without someone else checking that this is an actual bug and what I should do to fix it.
