nfsd4: allow restarting callbacks
If we lose the backchannel and then the client repairs the problem,
resend any callbacks.
We use a new cb_done flag to track whether there is still work to be
done for the callback or whether it can be destroyed with the rpc.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 69955e9..f1d9dd4 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -639,6 +639,10 @@
if (!nfsd41_cb_get_slot(clp, task))
return;
}
+ cb->cb_done = false;
+ spin_lock(&clp->cl_lock);
+ list_add(&cb->cb_per_client, &clp->cl_callbacks);
+ spin_unlock(&clp->cl_lock);
rpc_call_start(task);
}
@@ -681,8 +685,11 @@
return;
}
+ if (cb->cb_done)
+ return;
switch (task->tk_status) {
case 0:
+ cb->cb_done = true;
return;
case -EBADHANDLE:
case -NFS4ERR_BAD_STATEID:
@@ -695,7 +702,7 @@
if (current_rpc_client != task->tk_client) {
/* queue a callback on the new connection: */
atomic_inc(&dp->dl_count);
- nfsd4_cb_recall(dp);
+ run_nfsd4_cb(&dp->dl_recall);
return;
}
}
@@ -704,16 +711,23 @@
task->tk_status = 0;
rpc_restart_call_prepare(task);
return;
- } else
- nfsd4_mark_cb_down(clp, task->tk_status);
+ }
+ nfsd4_mark_cb_down(clp, task->tk_status);
+ cb->cb_done = true;
}
static void nfsd4_cb_recall_release(void *calldata)
{
struct nfsd4_callback *cb = calldata;
+ struct nfs4_client *clp = cb->cb_clp;
struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
- nfs4_put_delegation(dp);
+ if (cb->cb_done) {
+ spin_lock(&clp->cl_lock);
+ list_del(&cb->cb_per_client);
+ spin_unlock(&clp->cl_lock);
+ nfs4_put_delegation(dp);
+ }
}
static const struct rpc_call_ops nfsd4_cb_recall_ops = {
@@ -808,8 +822,13 @@
spin_unlock(&clp->cl_lock);
err = setup_callback_client(clp, &conn, ses);
- if (err)
+ if (err) {
warn_no_callback_path(clp, err);
+ return;
+ }
+ /* Yay, the callback channel's back! Restart any callbacks: */
+ list_for_each_entry(cb, &clp->cl_callbacks, cb_per_client)
+ run_nfsd4_cb(cb);
}
void nfsd4_do_callback_rpc(struct work_struct *w)
@@ -834,10 +853,11 @@
void nfsd4_cb_recall(struct nfs4_delegation *dp)
{
struct nfsd4_callback *cb = &dp->dl_recall;
+ struct nfs4_client *clp = dp->dl_client;
dp->dl_retries = 1;
cb->cb_op = dp;
- cb->cb_clp = dp->dl_client;
+ cb->cb_clp = clp;
cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL];
cb->cb_msg.rpc_argp = cb;
cb->cb_msg.rpc_resp = cb;
@@ -846,5 +866,7 @@
cb->cb_ops = &nfsd4_cb_recall_ops;
dp->dl_retries = 1;
+ cb->cb_done = true;
+
run_nfsd4_cb(&dp->dl_recall);
}