On 05/20/2011 02:47 PM, Dr. J. Bruce Fields wrote: > On Fri, May 20, 2011 at 01:52:43PM -0400, Trond Myklebust wrote: >> On Fri, 2011-05-20 at 13:26 -0400, Dr. J. Bruce Fields wrote: >>> On Fri, May 20, 2011 at 09:20:47AM -0700, Harry Edmon wrote: >>>> On 05/16/11 13:53, Dr. J. Bruce Fields wrote: >>>>> Hm, so the renews all have clid 465ccc4d09000000, and the reads all have >>>>> a stateid (0, 465ccc4dc24c0a0000000000). >>>>> >>>>> So the first 4 bytes matching just tells me both were handed out by the >>>>> same server instance (so there was no server reboot in between); there's >>>>> no way for me to tell whether they really belong to the same client. >>>>> >>>>> The server does assume that any stateid from the current server instance >>>>> that no longer exists in its table is expired. I believe that's >>>>> correct, given a correctly functioning client, but perhaps I'm missing a >>>>> case. >>>>> >>>>> --b. >>>> I am very appreciative of the quick initial comments I receive from >>>> all of you on my NFS problem. I notice that there has been silence >>>> on the problem since the 16th, so I assume that either this is a >>>> hard bug to track down or you have been busy with higher priority >>>> tasks. Is there anything I can do to help develop a solution to >>>> this problem? >>> >>> Well, the only candidate explanation for the problem is that my >>> assumption--that any time the server gets a stateid from the current >>> boot instance that it doesn't recognize as an active stateid, it is safe >>> for the server to return EXPIRED--is wrong. >>> >>> I don't immediately see why it's wrong, and based on the silence nobody >>> else does either, but I'm not 100% convinced I'm right either. >>> >>> So one approach might be to add server code that makes a better effort >>> to return EXPIRED only when we're sure it's a stateid from an expired >>> client, and see if that solves your problem. >>> >>> Remind me, did you have an easy way to reproduce your problem? >> >> My silence is simply because I'm mystified as to how this can happen. > > So since the client's sending it with a READ, the client thinks that the > stateid is still a valid open, lock, or delegation stateid, while the > server thinks it's not. Hm. I found this bug when I used "forget all locks" in the fault injection code I recently posted. Trond's fix works for me. - Bryan > > --b. > >> Patching for it is trivial (see below). >> >> When the server tells us that our lease is expired, the normal behaviour >> for the client is to re-establish the lease, and then proceed to recover >> all known stateids. I don't see how we can 'miss' a stateid that then >> needs to be recovered afterwards... > -- > 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 -- 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
