Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-wi0-f172.google.com ([209.85.212.172]:60551 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753142Ab2KLUtW (ORCPT ); Mon, 12 Nov 2012 15:49:22 -0500 Received: by mail-wi0-f172.google.com with SMTP id hm6so2882594wib.1 for ; Mon, 12 Nov 2012 12:49:21 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <4FA345DA4F4AE44899BD2B03EEEC2FA9092D7F52@SACEXCMBX04-PRD.hq.netapp.com> References: <1352745355-31157-1-git-send-email-bjschuma@netapp.com> <4FA345DA4F4AE44899BD2B03EEEC2FA9092D7F52@SACEXCMBX04-PRD.hq.netapp.com> Date: Mon, 12 Nov 2012 15:49:21 -0500 Message-ID: Subject: Re: [PATCH 1/2] NFS: Add sequence_priviliged_ops for nfs4_proc_sequence() From: Andy Adamson To: "Myklebust, Trond" Cc: "Schumaker, Bryan" , "linux-nfs@vger.kernel.org" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-nfs-owner@vger.kernel.org List-ID: On Mon, Nov 12, 2012 at 3:29 PM, Myklebust, Trond wrote: > On Mon, 2012-11-12 at 15:22 -0500, Andy Adamson wrote: >> On Mon, Nov 12, 2012 at 1:35 PM, wrote: >> > From: Bryan Schumaker >> > >> > During recovery the NFS4_SESSION_DRAINING flag might be set on the >> > client structure. This can cause lease renewal to abort when > > Not lease renewal. It is lease verification (i.e. checking that we have > a valid lease and session) that will deadlock. > >> > nfs41_setup_sequence sees that we are doing recovery. As a result, the >> > client never recovers and all activity with the NFS server halts. >> >> >> When does this happen? Say the session is draining, and an RPC returns >> from one of the compounds such as nfs_open, nfs_locku etc whose >> rpc_call_done routine calls renew_lease after freeing it's slot. Like >> all calls on a draining session, the renew_lease sleeps on the session >> slot_tbl_waitq - is this what you mean by "causes lease renewal to >> abort"? How does this cause the client to never recover? >> >> The only other call to renew_lease is from the state manager itself >> which runs one function at a time, and will not call renew_lease until >> the recovery is over.... >> >> What am I missing....? > > nfs4_check_lease() is run exclusively by the state manager thread in > order to check that the clientid (and session id on NFSv4.1) are valid. > It will deadlock the state manager thread if NFS4_SESSION_DRAINING is > already set. OK. NFS4_SESSION_DRAINING is also set exclusively by the state manager thread. Why is the state manager told to check the lease when it's also draining a session? No matter what the answer, please update the patch description to better explain the problem being solved. -->Andy > >> -->Andy >> >> >> > >> > Signed-off-by: Bryan Schumaker >> > --- >> > fs/nfs/nfs4proc.c | 21 +++++++++++++++++---- >> > 1 file changed, 17 insertions(+), 4 deletions(-) >> > >> > diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c >> > index 5eec442..537181c 100644 >> > --- a/fs/nfs/nfs4proc.c >> > +++ b/fs/nfs/nfs4proc.c >> > @@ -6138,13 +6138,26 @@ static void nfs41_sequence_prepare(struct rpc_task *task, void *data) >> > rpc_call_start(task); >> > } >> > >> > +static void nfs41_sequence_prepare_privileged(struct rpc_task *task, void *data) >> > +{ >> > + rpc_task_set_priority(task, RPC_PRIORITY_PRIVILEGED); >> > + nfs41_sequence_prepare(task, data); >> > +} >> > + >> > static const struct rpc_call_ops nfs41_sequence_ops = { >> > .rpc_call_done = nfs41_sequence_call_done, >> > .rpc_call_prepare = nfs41_sequence_prepare, >> > .rpc_release = nfs41_sequence_release, >> > }; >> > >> > -static struct rpc_task *_nfs41_proc_sequence(struct nfs_client *clp, struct rpc_cred *cred) >> > +static const struct rpc_call_ops nfs41_sequence_privileged_ops = { >> > + .rpc_call_done = nfs41_sequence_call_done, >> > + .rpc_call_prepare = nfs41_sequence_prepare_privileged, >> > + .rpc_release = nfs41_sequence_release, >> > +}; >> > + >> > +static struct rpc_task *_nfs41_proc_sequence(struct nfs_client *clp, struct rpc_cred *cred, >> > + const struct rpc_call_ops *seq_ops) >> > { >> > struct nfs4_sequence_data *calldata; >> > struct rpc_message msg = { >> > @@ -6154,7 +6167,7 @@ static struct rpc_task *_nfs41_proc_sequence(struct nfs_client *clp, struct rpc_ >> > struct rpc_task_setup task_setup_data = { >> > .rpc_client = clp->cl_rpcclient, >> > .rpc_message = &msg, >> > - .callback_ops = &nfs41_sequence_ops, >> > + .callback_ops = seq_ops, >> > .flags = RPC_TASK_ASYNC | RPC_TASK_SOFT, >> > }; >> > >> > @@ -6181,7 +6194,7 @@ static int nfs41_proc_async_sequence(struct nfs_client *clp, struct rpc_cred *cr >> > >> > if ((renew_flags & NFS4_RENEW_TIMEOUT) == 0) >> > return 0; >> > - task = _nfs41_proc_sequence(clp, cred); >> > + task = _nfs41_proc_sequence(clp, cred, &nfs41_sequence_ops); >> > if (IS_ERR(task)) >> > ret = PTR_ERR(task); >> > else >> > @@ -6195,7 +6208,7 @@ static int nfs4_proc_sequence(struct nfs_client *clp, struct rpc_cred *cred) >> > struct rpc_task *task; >> > int ret; >> > >> > - task = _nfs41_proc_sequence(clp, cred); >> > + task = _nfs41_proc_sequence(clp, cred, &nfs41_sequence_privileged_ops); >> > if (IS_ERR(task)) { >> > ret = PTR_ERR(task); >> > goto out; >> > -- >> > 1.8.0 >> > >> > -- >> > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in >> > the body of a message to majordomo@vger.kernel.org >> > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- > Trond Myklebust > Linux NFS client maintainer > > NetApp > Trond.Myklebust@netapp.com > www.netapp.com