NFSD: Reset cb_seq_status after NFS4ERR_DELAY

I noticed that once an NFSv4.1 callback operation gets a
NFS4ERR_DELAY status on CB_SEQUENCE and then the connection is lost,
the callback client loops, resending it indefinitely.

The switch arm in nfsd4_cb_sequence_done() that handles
NFS4ERR_DELAY uses rpc_restart_call() to rearm the RPC state machine
for the retransmit, but that path does not call the rpc_prepare_call
callback again. Thus cb_seq_status is set to -10008 by the first
NFS4ERR_DELAY result, but is never set back to 1 for the retransmits.

nfsd4_cb_sequence_done() thinks it's getting nothing but a
long series of CB_SEQUENCE NFS4ERR_DELAY replies.

Fixes: 7ba6cad6c88f ("nfsd: New helper nfsd4_cb_sequence_done() for processing more cb errors")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 926c29879c6ab892e4d12329169eb1b5b43d2649..43b0a34a5d5b8a3244db9304a630800050f87fb9 100644 (file)
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -1178,6 +1178,7 @@ static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback
                ret = false;
                break;
        case -NFS4ERR_DELAY:
+               cb->cb_seq_status = 1;
                if (!rpc_restart_call(task))
                        goto out;