On 01/01/04 02:48, Rüdiger Klaehn wrote:
Javier Fernandez-Ivern wrote:
Rüdiger Klaehn wrote:Fam is a user space library that has some nice features such as network transparent change notification. It currently uses the dnotify mechanism if the underlying kernel supports it, but as I mentioned the dnotify mechanism requires an open file handle and works only for single directories. If the underlying os does not support dnotify, fam resorts to polling for file changes (yuk!).
I have been wondering for some time why there is no decent file change notification mechanism in linux. Is there some deep philosophical reason for this, or is it just that nobody has found the time to implement it? If it is the latter, I am willing to implement it as long there is a chance to get this accepted into the mainstream kernel.
Well, there's fam. But AFAIK that's all done in user space, and your approach would be significantly more efficient (as a matter of fact, fam could be modified to use your change device as a first level of notification.)
Have you had a look at dazuko. It provides a consistent file access
notification mechanism (and also intervention for denying access) across
linux and freebsd. It is currently being used by various on-access
virus scanners. It is under active development and supports 2.6 (and 2.4)
File change notification would be immensely useful. I think there is a consensus about that.
Seems like a good idea. I've always thought it would be nice to use
something like this to maintain a dynamic locatedb (among many other
potential uses).