[PATCH] NFS4: Fix race to cl_confirm for v4.0 mount

[Benjamin Coddington <bcodding@redhat.com>]

After commit f02f3755dbd1 ("NFS4: Fix v4.0 client state corruption when
mount") I have reports that sometimes all open() calls fail with -EPERM.
It appears that a race between the SETCLIENTID in trunking discovery and
another superflous SETCLIENTID triggered by immediately running the state
manager causes the nfs_client cl_confirm value to be stored in the wrong
order.

It doesn't really make sense to invoke the state manager just to clear the
NFS4CLNT_LEASE_EXPIRED flag.  The flag has historically been used to signal
that a new client still needs to perform a SETCLIENTID before creating
state, but now that we have trunking discovery that flag is unnecessary.

Remove the flag, remove the call to schedule the state manager from
trunking discovery.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Fixes: f02f3755dbd1 ("NFS4: Fix v4.0 client state corruption when mount")
Cc: stable@vger.kernel.org #v5.2
---
 fs/nfs/nfs4client.c | 1 -
 fs/nfs/nfs4state.c  | 4 ----
 2 files changed, 5 deletions(-)

diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c
index da6204025a2d..56cb3613082d 100644
--- a/fs/nfs/nfs4client.c
+++ b/fs/nfs/nfs4client.c
@@ -215,7 +215,6 @@ struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *cl_init)
 	INIT_DELAYED_WORK(&clp->cl_renewd, nfs4_renew_state);
 	INIT_LIST_HEAD(&clp->cl_ds_clients);
 	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
-	clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
 	clp->cl_minorversion = cl_init->minorversion;
 	clp->cl_mvops = nfs_v4_minor_ops[cl_init->minorversion];
 	clp->cl_mig_gen = 1;
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index cad4e064b328..e1d5dc4a31d7 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -180,10 +180,6 @@ int nfs40_discover_server_trunking(struct nfs_client *clp,
 		/* Sustain the lease, even if it's empty.  If the clientid4
 		 * goes stale it's of no use for trunking discovery. */
 		nfs4_schedule_state_renewal(*result);
-
-		/* If the client state need to recover, do it. */
-		if (clp->cl_state)
-			nfs4_schedule_state_manager(clp);
 	}
 out:
 	return status;
-- 
2.20.1