[pnfs] crashes hit after mount timeout

[Benny Halevy]

Due to a problem on my server I hit timeouts in the mount process
(printing "Couldn't mount using minorversion 1")

looks like server->client needs to be cleaned up after a mount
error, as well as clp->cl_session shouldn't be dereferenced
in nfs4_recover_expired_lease (for the minorversion 0 case)

Benny

diff -Npu /tmp/tmp.29426.4 /var/export/home/bhalevy/dev/p4.local/pnfs-dev/fs/nfs/super.c -L a/fs/nfs/super.c -L b/fs/nfs/super.c
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -1313,6 +1313,7 @@ static int nfs4_fill_super(struct super_
                 server->client = nfs4_create_client(server, &timeparms, data->proto, authflavour);
                 if (IS_ERR(server->client)) {
                         err = PTR_ERR(server->client);
+			server->client = NULL;
                                 printk(KERN_EMERG "%s: cannot create RPC client. Error = %d\n",
                                                 __FUNCTION__, err);
                                 goto out_fail;
@@ -1329,6 +1330,7 @@ static int nfs4_fill_super(struct super_
                         if (err) {
                                 printk(KERN_EMERG "Couldn't mount using minorversion %d\n", i);
                                 rpc_shutdown_client(server->client);
+				server->client = NULL;
                         }
 			else
 				break;
diff -Npu /tmp/tmp.31257.1 /var/export/home/bhalevy/dev/p4.local/pnfs-dev/fs/nfs/nfs4proc.c -L a/fs/nfs/nfs4proc.c -L b/fs/nfs/nfs4proc.c
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -216,7 +216,8 @@ int nfs4_recover_expired_lease(struct nf
 	struct nfs4_client *clp = server->nfs4_state;
 
 	if (test_and_clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
-		clp->cl_session->expired = 1;
+		if (clp->cl_session)
+			clp->cl_session->expired = 1;
 		nfs4_schedule_state_recovery(clp);
 	}
 	return nfs4_wait_clnt_recover(server->client, clp);