Re: [RFC][PATCH 0/2] fsnotify: super block watch

From: Marko Rauhamaa
Date: Wed Dec 21 2016 - 05:30:51 EST


Amir Goldstein <amir73il@xxxxxxxxx>:

> On the Oct 10 posting you asked me about the use case and it was hard
> to explain the use case with only part of the work done.
>
> The issue, which this work sets to solve, is the poor scalability of
> recursive inotify watches.

On my [employer's] part, the fanotify API suffers from leakage through
namespaces.

If you need to monitor files in a filesystem, the current fanotify
FAN_MARK_MOUNT flag does not give you a notification if you execute a
command like

unshare -m touch xyz

inside the file system.

Amir's patch addresses this increasingly critical issue.


Marko