On Mon, Oct 27, 2008 at 05:14:38PM -0400, Peter Staubach wrote: > J. Bruce Fields wrote: >> On Mon, Oct 27, 2008 at 03:22:57PM -0400, Peter Staubach wrote: >> >>> J. Bruce Fields wrote: >>> >>>> On Mon, Oct 27, 2008 at 02:49:27PM +0800, hexf wrote: >>>> >>>>> We are using nfsv3. Now we meet a demand. If a client which hold a >>>>> lock crash, after it reboot, its statd daemon can notify the nfs >>>>> server to release the lock. But if this client will not reboot for >>>>> some reason(or will reboot after a long time), then the lock it >>>>> holding will not be released.In nfsv3 and nlmv4,it seems there is no >>>>> time-out mechnism for this situation. How would we solve this >>>>> question? My colleague advise me to modify the code of NLM/NSM to meet >>>>> this demand,but is seems quite a complicated work.Can you give me some >>>>> advice? >>>>> >>>> It might be possible to modify the server so that it dropped all locks >>>> from a client it hadn't heard from in a while. However, nfsv2/v3 >>>> clients are not required to contact the server regularly while they hold >>>> locks. So you may end up revoking locks held by perfectly good >>>> functioning clients. >>>> >>>> As an ugly workaround, rebooting the server will clear the problem, as >>>> it will notify clients to recover their locks on restart, and any dead >>>> clients will fail to recover their locks. >>>> >>>> >>> Didn't Wendy Cheng submit some patches to implement a >>> "clearlocks" sort of functionality? What happened with >>> them? >>> >> >> Yes, but that's motivated by the case of migrating all clients using one >> export; so it'll drop all locks held on a single filesystem, or all >> locks acquired using a single server (not client!) ip address. >> >> So if we want some finer-grained interface then that's yet to be >> designed. >> > > Sorry, I guess that I was remembering incorrectly. I was > thinking that she was looking for something like the clearlocks > functionality so that file systems could be migrated around > cleanly. That's what she was working on (and we merged), yes. But it doesn't help clear just the set of locks held by a single client. > It seems for this situation, we could use this sort of variation. I'm losing track of what those two "this"'s refer to! --b. -- 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
