Re: fanotify - overall design before I start sending patches

Tvrtko Ursulin
2009-08-04T16:21:40Z

Hi Eric, all,

On Friday 24 July 2009 21:13:49 Eric Paris wrote:
> If a FAN_ACCESS_PERM or FAN_OPEN_PERM event is received the listener
> must send a response before the 5 second timeout. If no response is
> sent before the 5 second timeout the original operation is allowed. If
> this happens too many times (10 in a row) the fanotify group is evicted
> from the kernel and will not get any new events. Sending a response is

Would it make more sense to deny on timeouts and then evict? I am thinking it
would be more secure with no significant drawbacks. Also for usages like HSM
allowing it without data being in place might present wrong content to the
user.

> The only other current interface is the ability to ignore events by
> superblock magic number. This makes it easy to ignore all events
> in /proc which can be difficult to accomplish firing FANOTIFY_SET_MARK
> with ignored_masks over and over as processes are created and destroyed.

Just to double-check, that would also work for any other filesystem and is
controllable from userspace?

Tvrtko