nfs: prevent backlogging of renewd requests

If the renewd send queue gets backlogged (e.g., if the server goes down),
we will keep filling the queue with periodic RENEW/SEQUENCE requests.

This patch schedules a new renewd request if and only if the previous one
returns (either success or failure)

Signed-off-by: Alexandros Batsakis <batsakis@netapp.com>
[Trond.Myklebust@netapp.com: moved nfs4_schedule_state_renewal() into
separate nfs4_renew_release() and nfs41_sequence_release() callbacks
to ensure correct behaviour on call setup failure]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Alexandros Batsakis
2010-02-05 03:45:04 -08:00
committed by Trond Myklebust
parent 888ef2e3f8
commit dc96aef96a
2 changed files with 27 additions and 21 deletions

View File

@@ -36,11 +36,6 @@
* as an rpc_task, not a real kernel thread, so it always runs in rpciod's
* context. There is one renewd per nfs_server.
*
* TODO: If the send queue gets backlogged (e.g., if the server goes down),
* we will keep filling the queue with periodic RENEW requests. We need a
* mechanism for ensuring that if renewd successfully sends off a request,
* then it only wakes up when the request is finished. Maybe use the
* child task framework of the RPC layer?
*/
#include <linux/mm.h>
@@ -63,7 +58,7 @@ nfs4_renew_state(struct work_struct *work)
struct nfs_client *clp =
container_of(work, struct nfs_client, cl_renewd.work);
struct rpc_cred *cred;
long lease, timeout;
long lease;
unsigned long last, now;
ops = nfs4_state_renewal_ops[clp->cl_minorversion];
@@ -75,7 +70,6 @@ nfs4_renew_state(struct work_struct *work)
lease = clp->cl_lease_time;
last = clp->cl_last_renewal;
now = jiffies;
timeout = (2 * lease) / 3 + (long)last - (long)now;
/* Are we close to a lease timeout? */
if (time_after(now, last + lease/3)) {
cred = ops->get_state_renewal_cred_locked(clp);
@@ -90,19 +84,15 @@ nfs4_renew_state(struct work_struct *work)
/* Queue an asynchronous RENEW. */
ops->sched_state_renewal(clp, cred);
put_rpccred(cred);
goto out_exp;
}
timeout = (2 * lease) / 3;
spin_lock(&clp->cl_lock);
} else
} else {
dprintk("%s: failed to call renewd. Reason: lease not expired \n",
__func__);
if (timeout < 5 * HZ) /* safeguard */
timeout = 5 * HZ;
dprintk("%s: requeueing work. Lease period = %ld\n",
__func__, (timeout + HZ - 1) / HZ);
cancel_delayed_work(&clp->cl_renewd);
schedule_delayed_work(&clp->cl_renewd, timeout);
spin_unlock(&clp->cl_lock);
spin_unlock(&clp->cl_lock);
}
nfs4_schedule_state_renewal(clp);
out_exp:
nfs_expire_unreferenced_delegations(clp);
out:
dprintk("%s: done\n", __func__);