Commit 47fcb03f authored by Trond Myklebust's avatar Trond Myklebust Committed by J. Bruce Fields
Browse files

SUNRPC: Fix the TCP server's send buffer accounting 



Currently, the sunrpc server is refusing to allow us to process new RPC
calls if the TCP send buffer is 2/3 full, even if we do actually have
enough free space to guarantee that we can send another request.
The following patch fixes svc_tcp_has_wspace() so that we only stop
processing requests if we know that the socket buffer cannot possibly fit
another reply.

It also fixes the tcp write_space() callback so that we only clear the
SOCK_NOSPACE flag when the TCP send buffer is less than 2/3 full.
This should ensure that the send window will grow as per the standard TCP
socket code.

Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@citi.umich.edu>
parent ab52ae6d

net/sunrpc/svcsock.c

+18 −17
Original line number Diff line number Diff line
@@ -380,6 +380,7 @@ static void svc_sock_setbufsize(struct socket *sock, unsigned int snd, 
	sock->sk->sk_sndbuf = snd * 2;

	sock->sk->sk_rcvbuf = rcv * 2;

	sock->sk->sk_userlocks |= SOCK_SNDBUF_LOCK|SOCK_RCVBUF_LOCK;

	sock->sk->sk_write_space(sock->sk);

	release_sock(sock->sk);

#endif

}
@@ -421,6 +422,15 @@ static void svc_write_space(struct sock *sk) 
	}

}



static void svc_tcp_write_space(struct sock *sk)

{

	struct socket *sock = sk->sk_socket;



	if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) && sock)

		clear_bit(SOCK_NOSPACE, &sock->flags);

	svc_write_space(sk);

}



/*

 * Copy the UDP datagram's destination address to the rqstp structure.

 * The 'destination' address in this case is the address to which the
@@ -1017,23 +1027,14 @@ static int svc_tcp_has_wspace(struct svc_xprt *xprt) 
	struct svc_sock *svsk =	container_of(xprt, struct svc_sock, sk_xprt);

	struct svc_serv *serv = svsk->sk_xprt.xpt_server;

	int required;

	int wspace;



	/*

	 * Set the SOCK_NOSPACE flag before checking the available

	 * sock space.

	 */

	if (test_bit(XPT_LISTENER, &xprt->xpt_flags))

		return 1;

	required = atomic_read(&xprt->xpt_reserved) + serv->sv_max_mesg;

	if (sk_stream_wspace(svsk->sk_sk) >= required)

		return 1;

	set_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);

	required = atomic_read(&svsk->sk_xprt.xpt_reserved) + serv->sv_max_mesg;

	wspace = sk_stream_wspace(svsk->sk_sk);



	if (wspace < sk_stream_min_wspace(svsk->sk_sk))

	return 0;

	if (required * 2 > wspace)

		return 0;



	clear_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);

	return 1;

}



static struct svc_xprt *svc_tcp_create(struct svc_serv *serv,
@@ -1089,7 +1090,7 @@ static void svc_tcp_init(struct svc_sock *svsk, struct svc_serv *serv) 
		dprintk("setting up TCP socket for reading\n");

		sk->sk_state_change = svc_tcp_state_change;

		sk->sk_data_ready = svc_tcp_data_ready;

		sk->sk_write_space = svc_write_space;

		sk->sk_write_space = svc_tcp_write_space;



		svsk->sk_reclen = 0;

		svsk->sk_tcplen = 0;

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