On Fri, Jul 07, 2017 at 06:51:37AM -0400, Jeff Layton wrote: > > Right. That's the case today if we don't remove support for old > filehandles. If we were to remove them, the clients would get back > -ESTALE there if they tried to use the old 2.2-style fh's that they saw > before the upgrade. > > The main takeaway here is that NFS filehandle lifetime is really only > bounded by the boot time of the oldest clients. Well, and how long an NFS server is still up. So one could construct a use case where a (hypothetical) system administrator had a RHEL 7.0 system with a 2.2.16-22 kernel, and they try to update it to a (hypothetical) RHEL 10 kernel in one fell swoop with a 4.13+ kernel that no longer supports the 2-2-style fh's. A client that had the server mounted when it was running the 2.2 kernel might only be up for a few hours, before the upgrade to RHEL 10 happened, and then the client would get ESTALE errors. Of course, I've stopped carrying about enterprise kernel support a long time ago, so I just think that scenario is funny. I recognize that folks who work at Red Hat have to worry about such things --- and I'm sorry. :-) In reality a server installed with RHEL 7.0 has probably died of old age by now --- unless someone crazy is running it in a VMware VM because they had some enterprise software package or some bar-code printing module for which they don't have source code[1], and so they are stuck on RHEL 7.0, even in 2017. Have I mentioned I'm so glad I don't have to worry these sorts of things any more? - Ted [1] That wasn't a made up example; I once visited a customer on site, back in the day, that had that exact problem, and so they were stuck on some antique version of RHEL, and they expected me to help them.