Commit 38a417cc authored by Tom Tucker's avatar Tom Tucker Committed by J. Bruce Fields
Browse files

svc: Add xpo_accept transport function 



Previously, the accept logic looked into the socket state to determine
whether to call accept or recv when data-ready was indicated on an endpoint.
Since some transports don't use sockets, this logic now uses a flag
bit (SK_LISTENER) to identify listening endpoints. A transport function
(xpo_accept) allows each transport to define its own accept processing.
A transport's initialization logic is reponsible for setting the
SK_LISTENER bit. I didn't see any way to do this in transport independent
logic since the passive side of a UDP connection doesn't listen and
always recv's.

In the svc_recv function, if the SK_LISTENER bit is set, the transport
xpo_accept function is called to handle accept processing.

Note that all functions are defined even if they don't make sense
for a given transport. For example, accept doesn't mean anything for
UDP. The function is defined anyway and bug checks if called. The
UDP transport should never set the SK_LISTENER bit.

Signed-off-by: default avatarTom Tucker <tom@opengridcomputing.com>
Acked-by: default avatarNeil Brown <neilb@suse.de>
Reviewed-by: default avatarChuck Lever <chuck.lever@oracle.com>
Reviewed-by: default avatarGreg Banks <gnb@sgi.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@citi.umich.edu>
parent d7979ae4

include/linux/sunrpc/svc_xprt.h

+1 −0
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
#include <linux/sunrpc/svc.h>



struct svc_xprt_ops {

	struct svc_xprt	*(*xpo_accept)(struct svc_xprt *);

	int		(*xpo_has_wspace)(struct svc_xprt *);

	int		(*xpo_recvfrom)(struct svc_rqst *);

	void		(*xpo_prep_reply_hdr)(struct svc_rqst *);

include/linux/sunrpc/svcsock.h

+1 −0
Original line number Diff line number Diff line
@@ -36,6 +36,7 @@ struct svc_sock { 
#define	SK_DEFERRED	8			/* request on sk_deferred */

#define	SK_OLD		9			/* used for temp socket aging mark+sweep */

#define	SK_DETACHED	10			/* detached from tempsocks list */

#define SK_LISTENER	11			/* listening endpoint */



	atomic_t    	    	sk_reserved;	/* space on outq that is reserved */

net/sunrpc/svcsock.c

+19 −12
Original line number Diff line number Diff line
@@ -896,6 +896,12 @@ static int svc_udp_has_wspace(struct svc_xprt *xprt) 
	return 1;

}



static struct svc_xprt *svc_udp_accept(struct svc_xprt *xprt)

{

	BUG();

	return NULL;

}



static struct svc_xprt_ops svc_udp_ops = {

	.xpo_recvfrom = svc_udp_recvfrom,

	.xpo_sendto = svc_udp_sendto,
@@ -904,6 +910,7 @@ static struct svc_xprt_ops svc_udp_ops = { 
	.xpo_free = svc_sock_free,

	.xpo_prep_reply_hdr = svc_udp_prep_reply_hdr,

	.xpo_has_wspace = svc_udp_has_wspace,

	.xpo_accept = svc_udp_accept,

};



static struct svc_xprt_class svc_udp_class = {
@@ -1028,9 +1035,9 @@ static inline int svc_port_is_privileged(struct sockaddr *sin) 
/*

 * Accept a TCP connection

 */

static void

svc_tcp_accept(struct svc_sock *svsk)

static struct svc_xprt *svc_tcp_accept(struct svc_xprt *xprt)

{

	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);

	struct sockaddr_storage addr;

	struct sockaddr	*sin = (struct sockaddr *) &addr;

	struct svc_serv	*serv = svsk->sk_server;
@@ -1042,7 +1049,7 @@ svc_tcp_accept(struct svc_sock *svsk) 


	dprintk("svc: tcp_accept %p sock %p\n", svsk, sock);

	if (!sock)

		return;

		return NULL;



	clear_bit(SK_CONN, &svsk->sk_flags);

	err = kernel_accept(sock, &newsock, O_NONBLOCK);
@@ -1053,7 +1060,7 @@ svc_tcp_accept(struct svc_sock *svsk) 
		else if (err != -EAGAIN && net_ratelimit())

			printk(KERN_WARNING "%s: accept failed (err %d)!\n",

				   serv->sv_name, -err);

		return;

		return NULL;

	}



	set_bit(SK_CONN, &svsk->sk_flags);
@@ -1147,11 +1154,11 @@ svc_tcp_accept(struct svc_sock *svsk) 
	if (serv->sv_stats)

		serv->sv_stats->nettcpconn++;



	return;

	return &newsvsk->sk_xprt;



failed:

	sock_release(newsock);

	return;

	return NULL;

}



/*
@@ -1176,12 +1183,6 @@ svc_tcp_recvfrom(struct svc_rqst *rqstp) 
		return svc_deferred_recv(rqstp);

	}



	if (svsk->sk_sk->sk_state == TCP_LISTEN) {

		svc_tcp_accept(svsk);

		svc_sock_received(svsk);

		return 0;

	}



	if (test_and_clear_bit(SK_CHNGBUF, &svsk->sk_flags))

		/* sndbuf needs to have room for one request

		 * per thread, otherwise we can stall even when the
@@ -1393,6 +1394,7 @@ static struct svc_xprt_ops svc_tcp_ops = { 
	.xpo_free = svc_sock_free,

	.xpo_prep_reply_hdr = svc_tcp_prep_reply_hdr,

	.xpo_has_wspace = svc_tcp_has_wspace,

	.xpo_accept = svc_tcp_accept,

};



static struct svc_xprt_class svc_tcp_class = {
@@ -1423,6 +1425,7 @@ svc_tcp_init(struct svc_sock *svsk) 


	if (sk->sk_state == TCP_LISTEN) {

		dprintk("setting up TCP socket for listening\n");

		set_bit(SK_LISTENER, &svsk->sk_flags);

		sk->sk_data_ready = svc_tcp_listen_data_ready;

		set_bit(SK_CONN, &svsk->sk_flags);

	} else {
@@ -1569,6 +1572,10 @@ svc_recv(struct svc_rqst *rqstp, long timeout) 
	if (test_bit(SK_CLOSE, &svsk->sk_flags)) {

		dprintk("svc_recv: found SK_CLOSE\n");

		svc_delete_socket(svsk);

	} else if (test_bit(SK_LISTENER, &svsk->sk_flags)) {

		struct svc_xprt *newxpt;

		newxpt = svsk->sk_xprt.xpt_ops->xpo_accept(&svsk->sk_xprt);

		svc_sock_received(svsk);

	} else {

		dprintk("svc: server %p, pool %u, socket %p, inuse=%d\n",

			rqstp, pool->sp_id, svsk, atomic_read(&svsk->sk_inuse));

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