Message ID | 1412008317-36182-2-git-send-email-andros@netapp.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
On Mon, Sep 29, 2014 at 12:31 PM, <andros@netapp.com> wrote: > From: Andy Adamson <andros@netapp.com> > > Commit 2f60ea6b8ced ("NFSv4: The NFSv4.0 client must send RENEW calls if it holds a delegation") set the NFS4_RENEW_TIMEOUT flag in nfs4_renew_state, and does > not put an nfs41_proc_async_sequence call, the NFSv4.1 lease renewal heartbeat > call, on the wire to renew the NFSv4.1 state if the flag was not set. > > The NFS4_RENEW_TIMEOUT flag is set when "now" is after the last renewal > (cl_last_renewal) plus the lease time divided by 3. This is arbitrary and > sometimes does the following: > > In normal operation, the only way a future state renewal call is put on the > wire is via a call to nfs4_schedule_state_renewal, which schedules a > nfs4_renew_state workqueue task. nfs4_renew_state determines if the > NFS4_RENEW_TIMEOUT should be set, and the calls nfs41_proc_async_sequence, > which only gets sent if the NFS4_RENEW_TIMEOUT flag is set. > Then the nfs41_proc_async_sequence rpc_release function schedules > another state remewal via nfs4_schedule_state_renewal. > > Without this change we can get into a state where an application stops > accessing the NFSv4.1 share, state renewal calls stop due to the > NFS4_RENEW_TIMEOUT flag _not_ being set. The only way to recover > from this situation is with a clientid re-establishment, once the application > resumes and the server has timed out the lease and so returns > NFS4ERR_BAD_SESSION on the subsequent SEQUENCE operation. > > An example application: > open, lock, write a file. > > sleep for 6 * lease (could be less) > > ulock, close. > > In the above example with NFSv4.1 delegations enabled, without this change, > there are no OP_SEQUENCE state renewal calls during the sleep, and the > clientid is recovered due to lease expiration on the close. > > This issue does not occur with NFSv4.1 delegations disabled, nor with > NFSv4.0, with or without delegations enabled. > > Signed-off-by: Andy Adamson <andros@netapp.com> > --- > fs/nfs/nfs4proc.c | 2 +- > fs/nfs/nfs4renewd.c | 14 ++++++++++++-- > 2 files changed, 13 insertions(+), 3 deletions(-) > > diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c > index 288be08..ed25f38 100644 > --- a/fs/nfs/nfs4proc.c > +++ b/fs/nfs/nfs4proc.c > @@ -7349,7 +7349,7 @@ static int nfs41_proc_async_sequence(struct nfs_client *clp, struct rpc_cred *cr > int ret = 0; > > if ((renew_flags & NFS4_RENEW_TIMEOUT) == 0) > - return 0; > + return -EAGAIN; > task = _nfs41_proc_sequence(clp, cred, false); > if (IS_ERR(task)) > ret = PTR_ERR(task); > diff --git a/fs/nfs/nfs4renewd.c b/fs/nfs/nfs4renewd.c > index 1720d32..b00e1e2 100644 > --- a/fs/nfs/nfs4renewd.c > +++ b/fs/nfs/nfs4renewd.c > @@ -88,16 +88,26 @@ nfs4_renew_state(struct work_struct *work) > } > nfs_expire_all_delegations(clp); > } else { > + int ret; > + > /* Queue an asynchronous RENEW. */ > - ops->sched_state_renewal(clp, cred, renew_flags); > + ret = ops->sched_state_renewal(clp, cred, renew_flags); > put_rpccred(cred); > - goto out_exp; > + switch (ret) { > + case 0: > + default: > + goto out_exp; Nit: the 0 and default cases do not need to be explicit since the default behaviour will be to fall through anyway. > + case -EAGAIN: > + case -ENOMEM: > + goto out_sched; > + } > } > } else { > dprintk("%s: failed to call renewd. Reason: lease not expired \n", > __func__); > spin_unlock(&clp->cl_lock); > } > +out_sched: > nfs4_schedule_state_renewal(clp); > out_exp: > nfs_expire_unreferenced_delegations(clp); > -- > 1.8.3.1 > Thanks Andy.
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 288be08..ed25f38 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -7349,7 +7349,7 @@ static int nfs41_proc_async_sequence(struct nfs_client *clp, struct rpc_cred *cr int ret = 0; if ((renew_flags & NFS4_RENEW_TIMEOUT) == 0) - return 0; + return -EAGAIN; task = _nfs41_proc_sequence(clp, cred, false); if (IS_ERR(task)) ret = PTR_ERR(task); diff --git a/fs/nfs/nfs4renewd.c b/fs/nfs/nfs4renewd.c index 1720d32..b00e1e2 100644 --- a/fs/nfs/nfs4renewd.c +++ b/fs/nfs/nfs4renewd.c @@ -88,16 +88,26 @@ nfs4_renew_state(struct work_struct *work) } nfs_expire_all_delegations(clp); } else { + int ret; + /* Queue an asynchronous RENEW. */ - ops->sched_state_renewal(clp, cred, renew_flags); + ret = ops->sched_state_renewal(clp, cred, renew_flags); put_rpccred(cred); - goto out_exp; + switch (ret) { + case 0: + default: + goto out_exp; + case -EAGAIN: + case -ENOMEM: + goto out_sched; + } } } else { dprintk("%s: failed to call renewd. Reason: lease not expired \n", __func__); spin_unlock(&clp->cl_lock); } +out_sched: nfs4_schedule_state_renewal(clp); out_exp: nfs_expire_unreferenced_delegations(clp);