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: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 30b17b3..6f524a9 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -246,6 +246,7 @@
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
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index fb92f51..a3af021 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -570,6 +570,7 @@
xprt_disconnect(xprt);
xprt->ops->close(xprt);
+ clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
xprt_release_write(xprt, NULL);
}
@@ -588,6 +589,25 @@
}
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)
{
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 6fa52f4..abb40c14 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -1122,10 +1122,7 @@
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);
}