On Thu, Feb 12, 2009 at 03:00:51PM -0500, David P. Quigley wrote: > We also explored a callback for label change notification. I think we > even have the code lying around for the prototype. It worked but Trond > expressed some concern with how well it would scale. The issue Trond > raised is what happens if you relabel an entire file system from under a > set of NFSv4 clients? I'm not sure how much of a concern this will be
Surely it would scale no better and no worse than open file delegation... > since 1) File relabeling is supposed to be rare and 2) clients will > probably have a small subset of files open. In the event that you do Reclassification of data is supposed to be rare, though that may vary a lot by environment. The number of files that may be kept open provides a natural limit to how many relabel callbacks will be needed. (A client could OPEN every file at limit cost to itself hoping to overwhelm a server, but that's a separate issue.) > need to relabel the entire file system on the server it might be a good > idea from an administrative perspective to have your clients remount the > NFS shares and flush whatever caches they have. Well, there's no callback to tell clients to flush all writes and remount (or recover). You could simulate a server reboot and force recovery though. Nico --
