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>
diff --git a/fs/nfs/nfs4renewd.c b/fs/nfs/nfs4renewd.c
index 0156c01..d87f103 100644
--- a/fs/nfs/nfs4renewd.c
+++ b/fs/nfs/nfs4renewd.c
@@ -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 @@
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 @@
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 @@
/* 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__);
