Re: [RFC] 0/11 fanotify: fscking all notifiction and file accesssystem (intended for antivirus scanning and file indexers)

From: david
Date: Sat Sep 27 2008 - 02:06:22 EST


On Fri, 26 Sep 2008, Eric Paris wrote:

fanotify has 7 event types and only sends events for S_ISREG() files.
The event types are OPEN, READ, WRITE, CLOSE_WRITE, CLOSE_NOWRITE,
OPEN_ACCESS, and READ_ACCESS. Events OPEN_ACCESS and READ_ACCESS
require that the listener return some sort of allow/deny/more_time
response as the original process blocks until it gets an event (or times
out.) listeners may register a group which will get notifications about
any combination of these events. Antivirus scanners will likely want
OPEN_ACCESS and READ_ACCESS while file indexers would likely use the
non-ACCESS form of these events.

sending a message out for every READ/WRITE seems like it will generate a LOT of messages, and very few will be ones that anyone cares about.

one of the nice things about the TALPA approach was that there was an ability to notify only on a change of state (i.e. when a file that had been scanned was changed)

this could do a similar thing, but I think it would be a much more expensive process to do it all in userspace.

David Lang

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/