Re: [RFC][PATCH 0/7] fanotify: add support for more events

Marko Rauhamaa
2016-10-13T18:51:54Z

Amir Goldstein:
> This series is a prep work for using fanotify to monitor all events in
> a file system with a single watch.
>
> [...]
>
> I am posting this WIP to get feedback on the idea and to find out if
> there are any users out there interested in the improved fanotify
> capabilities and/or in the super block monitoring use case.

My employer certainly is in need of monitoring a whole filesystem. We
have noticed that namespaces evade monitoring via FAN_MARK_MOUNT. I was
thinking something like a FAN_MARK_FILESYSTEM would be needed.

(There are some other needed features but filesystem monitoring is the
most pressing one.)

Jan Kara:
> Careful here. In the world of user namespaces and containers you have
> to be really careful so that events from one container don't leak into
> another container despite they live in the same physical filesystem,
> just a different bind mount.

Obviously, proper care needs to be taken, but a namespace should not be
able smuggle filesystem events past fanotify monitoring.

Marko