On Thu, 19 Jun 2008 11:37:17 -0400 Olga Kornievskaia <aglo@xxxxxxxxxxxxxx> wrote: > > > Trond Myklebust wrote: > > On Tue, 2008-06-17 at 17:36 -0400, J. Bruce Fields wrote: > > > >> On Mon, Jun 16, 2008 at 10:28:59AM -0400, Jeff Layton wrote: > >> > >>> On Fri, 13 Jun 2008 18:50:37 -0400 > >>> "J. Bruce Fields" <bfields@xxxxxxxxxxxxxx> wrote: > >>> > >>> > >>>> The client needs a new more estensible text-based upcall to gssd, to > >>>> make it easier to support some features that are needed for new krb5 > >>>> enctypes, for callbacks, etc. > >>>> > >>>> We will have to continue to support the old upcall for backwards > >>>> compatibility with older gssd's. To simplify upgrades, as well as > >>>> testing and debugging, it would help if we can upgrade gssd without > >>>> having to choose at boot (or module-load) time whether we want the new > >>>> or the old upcall. > >>>> > >>>> That means that when gssd opens an rpc upcall pipe, we'd like to just > >>>> start using whichever version it chose immediately--ideally without > >>>> having to wait the 30 seconds that it would normally take for upcalls > >>>> already queued on the wrong upcall pipe to time out. > >>>> > >>>> The following patches do that by queueing the upcalls on whichever of > >>>> the two upcall pipes (the new one and the old one) that somebody holds > >>>> open. If nobody's opened anything yet, then upcalls are provisionally > >>>> queued on the new pipe. I add a pipe_open method to allow the gss code > >>>> to keep track of which pipe is open, to prevent anyone from attempting > >>>> to open both pipes at once, and to cancel any upcalls that got queued to > >>>> the wrong pipe. > >>>> > >>>> I did some minimal testing with the old upcall, but haven't tested the > >>>> new upcall yet. (Olga, could you do that?) So this is just an RFC at > >>>> this point. > >>>> > >>>> --b. > >>>> > >>> Has any thought been given to moving all of the rpc_pipefs upcalls to use > >>> the keyctl API that David Howells did? It seems like that would be better > >>> suited to this sort of application than rpc_pipefs... > >>> > >> I haven't looked at it. I've just assumed that since Trond and Kevin > >> have both looked at both API's, then there must be some good reason > >> we're not using it.... > >> > > > > Kevin has spent quite some time working on the keyring support, but as > > far as I understand the amount of time he can continue to spend working > > for CITI has recently been heavily reduced... > > > > > I don't think we ever considered replacing NFS's client upcall > mechanism. Why would we scrap a perfectly good implementation that Trond > keeps on improving and making better? > Because it's less code that we have to maintain. rpc_pipefs certainly works (and works fairly well), but we have so many upcall mechanisms in the kernel already. keyctl also has some nice features (automated cache timeouts, granular security, etc), and was designed with this sort of use in mind. I'm not saying that we absolutely need to scrap rpc_pipefs, but considering alternatives may mean less work for us all in the long run. -- Jeff Layton <jlayton@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
