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: Tom Tucker <tom@opengridcomputing.com>
Acked-by: Neil Brown <neilb@suse.de>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Greg Banks <gnb@sgi.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
diff --git a/include/linux/sunrpc/svc_xprt.h b/include/linux/sunrpc/svc_xprt.h
index 85df97a..31a44f4 100644
--- a/include/linux/sunrpc/svc_xprt.h
+++ b/include/linux/sunrpc/svc_xprt.h
@@ -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 *);
diff --git a/include/linux/sunrpc/svcsock.h b/include/linux/sunrpc/svcsock.h
index 08e78d0a..9882ce0 100644
--- a/include/linux/sunrpc/svcsock.h
+++ b/include/linux/sunrpc/svcsock.h
@@ -36,6 +36,7 @@
#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 */
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 603db98..41d1f81 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -896,6 +896,12 @@
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 @@
.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 @@
/*
* 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 @@
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 @@
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 @@
if (serv->sv_stats)
serv->sv_stats->nettcpconn++;
- return;
+ return &newsvsk->sk_xprt;
failed:
sock_release(newsock);
- return;
+ return NULL;
}
/*
@@ -1176,12 +1183,6 @@
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 @@
.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 @@
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 @@
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));