file system change notifications

[O'Connor, Daniel]

> On 12 Mar 2015, at 05:31, Kim Shrier <kim at westryn.net> wrote:
> I have a project where I need to notice changes to files in a large directory tree.
> I noticed that there was a project in GSOC 2010 to implement such a feature.
> 
> https://wiki.freebsd.org/SOC2010IlyaPutsikau 
> 
> It appears that it was never completed.  Is it desirable to have this project
> completed and added into FreeBSD.  Or, is there another way to get file
> system change notifications?

The 'standard' way is kqueue + masses of file descriptors.

I am looking at using auditpipe(4) since you can register to be notified for all file modifications and you get a path.

I wrote some test code at https://gist.github.com/DanielO/e36de242e79fed3fe4f7

Ideally we could add an inotify() syscall although I think that is still suboptimal since you need to add a watch per directory so it can be relatively expensive to setup. That said working out what to do in the face of links and so on is tricky..

--
Daniel O'Connor
"The nice thing about standards is that there
are so many of them to choose from."
 -- Andrew Tanenbaum
GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C