On May 20, 2011, at 3:29 PM, Harry Edmon wrote: > On 05/20/11 10:52, 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. >> 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... >> >> Cheers >> Trond >> >> 8<---------------------------------------------------------------------------- >> From 920ddb153f28717be363f6e87dde24ef2a8d0ce2 Mon Sep 17 00:00:00 2001 >> From: Trond Myklebust<Trond.Myklebust@xxxxxxxxxx> >> Date: Fri, 20 May 2011 13:44:02 -0400 >> Subject: [PATCH] NFSv4: Handle expired stateids when the lease is still valid >> >> Currently, if the server returns NFS4ERR_EXPIRED in reply to a READ or >> WRITE, but the RENEW test determines that the lease is still active, we >> fail to recover and end up looping forever in a READ/WRITE + RENEW death >> spiral. >> >> Signed-off-by: Trond Myklebust<Trond.Myklebust@xxxxxxxxxx> >> --- >> fs/nfs/nfs4proc.c | 9 +++++++-- >> 1 files changed, 7 insertions(+), 2 deletions(-) >> >> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c >> index cf1b339..d0e15db 100644 >> --- a/fs/nfs/nfs4proc.c >> +++ b/fs/nfs/nfs4proc.c >> @@ -267,9 +267,11 @@ static int nfs4_handle_exception(struct nfs_server *server, int errorcode, struc >> break; >> nfs4_schedule_stateid_recovery(server, state); >> goto wait_on_recovery; >> + case -NFS4ERR_EXPIRED: >> + if (state != NULL) >> + nfs4_schedule_stateid_recovery(server, state); >> case -NFS4ERR_STALE_STATEID: >> case -NFS4ERR_STALE_CLIENTID: >> - case -NFS4ERR_EXPIRED: >> nfs4_schedule_lease_recovery(clp); >> goto wait_on_recovery; >> #if defined(CONFIG_NFS_V4_1) >> @@ -3670,9 +3672,11 @@ nfs4_async_handle_error(struct rpc_task *task, const struct nfs_server *server, >> break; >> nfs4_schedule_stateid_recovery(server, state); >> goto wait_on_recovery; >> + case -NFS4ERR_EXPIRED: >> + if (state != NULL) >> + nfs4_schedule_stateid_recovery(server, state); >> case -NFS4ERR_STALE_STATEID: >> case -NFS4ERR_STALE_CLIENTID: >> - case -NFS4ERR_EXPIRED: >> nfs4_schedule_lease_recovery(clp); >> goto wait_on_recovery; >> #if defined(CONFIG_NFS_V4_1) >> @@ -4543,6 +4547,7 @@ int nfs4_lock_delegation_recall(struct nfs4_state *state, struct file_lock *fl) >> case -ESTALE: >> goto out; >> case -NFS4ERR_EXPIRED: >> + nfs4_schedule_stateid_recovery(server, state); >> case -NFS4ERR_STALE_CLIENTID: >> case -NFS4ERR_STALE_STATEID: >> nfs4_schedule_lease_recovery(server->nfs_client); >> > I installed this patch on my client, and now I am seeing the state manager appear in the process accounting file about once a minute rather that the constant respawning I saw earlier. Is once a minute normal, or is there still a problem? The state manager sends the lease renew heart-beat. It should spawn every lease period unless a lease-renewing operation (one with state) happens to be sent. -->Andy > > -- > Dr. Harry Edmon E-MAIL: harry@xxxxxx > 206-543-0547 FAX: 206-543-0308 harry@xxxxxxxxxxxxxxxxxxxx > Director of IT, College of the Environment and > Director of Computing, Dept of Atmospheric Sciences > University of Washington, Box 351640, Seattle, WA 98195-1640 > > -- > 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
