On Mon, Dec 10, 2018 at 01:12:31PM -0500, Jeff Layton wrote: > On Mon, 2018-12-10 at 12:47 -0500, J. Bruce Fields wrote: > > We've got a long-standing complaint that tools like lsof, when run on an > > NFS server, overlook opens and locks held by NFS clients. > > > > The information's all there, it's just a question of how to expose it. > > > > Easiest might be a single flat file like /proc/locks, but I've always > > hoped we could do something slightly more structured, using a > > subdirectory per NFS client. > > > > Jeff Layton looked into this several years ago. I don't remember if > > there was some particular issue or if he just got bogged down in VFS > > details. > > > > I think I had a patch that generated a single flat file for locks, but > you wanted to present a directory or file per-client, and I just never > got around to reworking the earlier patch. Oh, OK, makes sense. > That sounds like a great start. Some ideas: > > The locks file could also list delegations and layouts, but it might be > good to do them in separate files. That would make it cleaner to display > info that is only relevant to those types (recall info, in particular). > > You might also consider adding a v4-specific info file. Show things like > "when was last lease renewal"? Yes, good ideas. I hope this could be expandable in such a way that we don't need all of that at the start. I also had some idea that we might eventually also benefit from some two-way communication. But the only idea I had there was some sort of "destroy this client now" operation, which is probably less important for NFSv4 state, since it gets cleaned up automatically on lease expiry. --b.
