Commit 66af1e55 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

SUNRPC: Fix a race in xs_tcp_state_change() 



When scheduling the autoclose RPC call, we want to ensure that we don't
race against the test_bit() call in xprt_clear_locked().

Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent ef818a28

include/linux/sunrpc/xprt.h

+1 −0
Original line number Diff line number Diff line
@@ -246,6 +246,7 @@ struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid); 
void			xprt_complete_rqst(struct rpc_task *task, int copied);

void			xprt_release_rqst_cong(struct rpc_task *task);

void			xprt_disconnect(struct rpc_xprt *xprt);

void			xprt_force_disconnect(struct rpc_xprt *xprt);



/*

 * Reserved bit positions in xprt->state

net/sunrpc/xprt.c

+20 −0
Original line number Diff line number Diff line
@@ -570,6 +570,7 @@ static void xprt_autoclose(struct work_struct *work) 


	xprt_disconnect(xprt);

	xprt->ops->close(xprt);

	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);

	xprt_release_write(xprt, NULL);

}
@@ -588,6 +589,25 @@ void xprt_disconnect(struct rpc_xprt *xprt) 
}

EXPORT_SYMBOL_GPL(xprt_disconnect);



/**

 * xprt_force_disconnect - force a transport to disconnect

 * @xprt: transport to disconnect

 *

 */

void xprt_force_disconnect(struct rpc_xprt *xprt)

{

	/* Don't race with the test_bit() in xprt_clear_locked() */

	spin_lock_bh(&xprt->transport_lock);

	set_bit(XPRT_CLOSE_WAIT, &xprt->state);

	/* Try to schedule an autoclose RPC call */

	if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)

		queue_work(rpciod_workqueue, &xprt->task_cleanup);

	else if (xprt->snd_task != NULL)

		rpc_wake_up_task(xprt->snd_task);

	spin_unlock_bh(&xprt->transport_lock);

}

EXPORT_SYMBOL_GPL(xprt_force_disconnect);



static void

xprt_init_autodisconnect(unsigned long data)

{

net/sunrpc/xprtsock.c

+1 −4
Original line number Diff line number Diff line
@@ -1122,10 +1122,7 @@ static void xs_tcp_state_change(struct sock *sk) 
	case TCP_SYN_RECV:

		break;

	case TCP_CLOSE_WAIT:

		/* Try to schedule an autoclose RPC calls */

		set_bit(XPRT_CLOSE_WAIT, &xprt->state);

		if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)

			queue_work(rpciod_workqueue, &xprt->task_cleanup);

		xprt_force_disconnect(xprt);

	default:

		xprt_disconnect(xprt);

	}