rxrpc: Correctly initialise, limit and transmit call->rx_winsize

call->rx_winsize should be initialised to the sysctl setting and the sysctl
setting should be limited to the maximum we want to permit.  Further, we
need to place this in the ACK info instead of the sysctl setting.

Furthermore, discard the idea of accepting the subpackets of a jumbo packet
that lie beyond the receive window when the first packet of the jumbo is
within the window.  Just discard the excess subpackets instead.  This
allows the receive window to be opened up right to the buffer size less one
for the dead slot.

Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 47c74a5..e78c40b 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -498,6 +498,7 @@
 	 */
 #define RXRPC_RXTX_BUFF_SIZE	64
 #define RXRPC_RXTX_BUFF_MASK	(RXRPC_RXTX_BUFF_SIZE - 1)
+#define RXRPC_INIT_RX_WINDOW_SIZE 32
 	struct sk_buff		**rxtx_buffer;
 	u8			*rxtx_annotations;
 #define RXRPC_TX_ANNO_ACK	0
@@ -518,7 +519,7 @@
 	rxrpc_seq_t		rx_expect_next;	/* Expected next packet sequence number */
 	u8			rx_winsize;	/* Size of Rx window */
 	u8			tx_winsize;	/* Maximum size of Tx window */
-	u8			nr_jumbo_dup;	/* Number of jumbo duplicates */
+	u8			nr_jumbo_bad;	/* Number of jumbo dups/exceeds-windows */
 
 	/* receive-phase ACK management */
 	u8			ackr_reason;	/* reason to ACK */