2007-12-31 03:07:42

by Tom Tucker

[permalink] [raw]
Subject: [PATCH 14/40] svc: Add a generic transport svc_create_xprt function


The svc_create_xprt function is a transport independent version
of the svc_makesock function.

Since transport instance creation contains transport dependent and
independent components, add an xpo_create transport function. The
transport implementation of this function allocates the memory for the
endpoint, implements the transport dependent initialization logic, and
calls svc_xprt_init to initialize the transport independent field (svc_xprt)
in it's data structure.

Signed-off-by: Tom Tucker <[email protected]>
---

include/linux/sunrpc/svc_xprt.h | 4 +++
net/sunrpc/svc_xprt.c | 37 ++++++++++++++++++++++++
net/sunrpc/svcsock.c | 59 +++++++++++++++++++++++++++++----------
3 files changed, 85 insertions(+), 15 deletions(-)

diff --git a/include/linux/sunrpc/svc_xprt.h b/include/linux/sunrpc/svc_xprt.h
index 31a44f4..986a5a0 100644
--- a/include/linux/sunrpc/svc_xprt.h
+++ b/include/linux/sunrpc/svc_xprt.h
@@ -10,6 +10,9 @@
#include <linux/sunrpc/svc.h>

struct svc_xprt_ops {
+ struct svc_xprt *(*xpo_create)(struct svc_serv *,
+ struct sockaddr *, int,
+ int);
struct svc_xprt *(*xpo_accept)(struct svc_xprt *);
int (*xpo_has_wspace)(struct svc_xprt *);
int (*xpo_recvfrom)(struct svc_rqst *);
@@ -36,5 +39,6 @@ struct svc_xprt {
int svc_reg_xprt_class(struct svc_xprt_class *);
void svc_unreg_xprt_class(struct svc_xprt_class *);
void svc_xprt_init(struct svc_xprt_class *, struct svc_xprt *);
+int svc_create_xprt(struct svc_serv *, char *, unsigned short, int);

#endif /* SUNRPC_SVC_XPRT_H */
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index fe5270f..6ff5ca7 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -81,3 +81,40 @@ void svc_xprt_init(struct svc_xprt_class *xcl, struct svc_xprt *xprt)
xprt->xpt_ops = xcl->xcl_ops;
}
EXPORT_SYMBOL_GPL(svc_xprt_init);
+
+int svc_create_xprt(struct svc_serv *serv, char *xprt_name, unsigned short port,
+ int flags)
+{
+ struct svc_xprt_class *xcl;
+ int ret = -ENOENT;
+ struct sockaddr_in sin = {
+ .sin_family = AF_INET,
+ .sin_addr.s_addr = INADDR_ANY,
+ .sin_port = htons(port),
+ };
+ dprintk("svc: creating transport %s[%d]\n", xprt_name, port);
+ spin_lock(&svc_xprt_class_lock);
+ list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) {
+ if (strcmp(xprt_name, xcl->xcl_name) == 0) {
+ spin_unlock(&svc_xprt_class_lock);
+ if (try_module_get(xcl->xcl_owner)) {
+ struct svc_xprt *newxprt;
+ ret = 0;
+ newxprt = xcl->xcl_ops->xpo_create
+ (serv,
+ (struct sockaddr *)&sin, sizeof(sin),
+ flags);
+ if (IS_ERR(newxprt)) {
+ module_put(xcl->xcl_owner);
+ ret = PTR_ERR(newxprt);
+ }
+ }
+ goto out;
+ }
+ }
+ spin_unlock(&svc_xprt_class_lock);
+ dprintk("svc: transport %s not found\n", xprt_name);
+ out:
+ return ret;
+}
+EXPORT_SYMBOL_GPL(svc_create_xprt);
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 6e9dc8f..9f0f6d0 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -91,6 +91,8 @@ static void svc_sock_free(struct svc_xprt *);
static struct svc_deferred_req *svc_deferred_dequeue(struct svc_sock *svsk);
static int svc_deferred_recv(struct svc_rqst *rqstp);
static struct cache_deferred_req *svc_defer(struct cache_req *req);
+static struct svc_xprt *svc_create_socket(struct svc_serv *, int,
+ struct sockaddr *, int, int);

/* apparently the "standard" is that clients close
* idle connections after 5 minutes, servers after
@@ -365,6 +367,7 @@ svc_sock_put(struct svc_sock *svsk)
{
if (atomic_dec_and_test(&svsk->sk_inuse)) {
BUG_ON(!test_bit(SK_DEAD, &svsk->sk_flags));
+ module_put(svsk->sk_xprt.xpt_class->xcl_owner);
svsk->sk_xprt.xpt_ops->xpo_free(&svsk->sk_xprt);
}
}
@@ -902,7 +905,15 @@ static struct svc_xprt *svc_udp_accept(struct svc_xprt *xprt)
return NULL;
}

+static struct svc_xprt *svc_udp_create(struct svc_serv *serv,
+ struct sockaddr *sa, int salen,
+ int flags)
+{
+ return svc_create_socket(serv, IPPROTO_UDP, sa, salen, flags);
+}
+
static struct svc_xprt_ops svc_udp_ops = {
+ .xpo_create = svc_udp_create,
.xpo_recvfrom = svc_udp_recvfrom,
.xpo_sendto = svc_udp_sendto,
.xpo_release_rqst = svc_release_skb,
@@ -915,6 +926,7 @@ static struct svc_xprt_ops svc_udp_ops = {

static struct svc_xprt_class svc_udp_class = {
.xcl_name = "udp",
+ .xcl_owner = THIS_MODULE,
.xcl_ops = &svc_udp_ops,
.xcl_max_payload = RPCSVC_MAXPAYLOAD_UDP,
};
@@ -1384,7 +1396,15 @@ static int svc_tcp_has_wspace(struct svc_xprt *xprt)
return 1;
}

+static struct svc_xprt *svc_tcp_create(struct svc_serv *serv,
+ struct sockaddr *sa, int salen,
+ int flags)
+{
+ return svc_create_socket(serv, IPPROTO_TCP, sa, salen, flags);
+}
+
static struct svc_xprt_ops svc_tcp_ops = {
+ .xpo_create = svc_tcp_create,
.xpo_recvfrom = svc_tcp_recvfrom,
.xpo_sendto = svc_tcp_sendto,
.xpo_release_rqst = svc_release_skb,
@@ -1397,6 +1417,7 @@ static struct svc_xprt_ops svc_tcp_ops = {

static struct svc_xprt_class svc_tcp_class = {
.xcl_name = "tcp",
+ .xcl_owner = THIS_MODULE,
.xcl_ops = &svc_tcp_ops,
.xcl_max_payload = RPCSVC_MAXPAYLOAD_TCP,
};
@@ -1573,8 +1594,14 @@ svc_recv(struct svc_rqst *rqstp, long timeout)
} else if (test_bit(SK_LISTENER, &svsk->sk_flags)) {
struct svc_xprt *newxpt;
newxpt = svsk->sk_xprt.xpt_ops->xpo_accept(&svsk->sk_xprt);
- if (newxpt)
+ if (newxpt) {
+ /*
+ * We know this module_get will succeed because the
+ * listener holds a reference too
+ */
+ __module_get(newxpt->xpt_class->xcl_owner);
svc_check_conn_limits(svsk->sk_server);
+ }
svc_sock_received(svsk);
} else {
dprintk("svc: server %p, pool %u, socket %p, inuse=%d\n",
@@ -1814,8 +1841,10 @@ EXPORT_SYMBOL_GPL(svc_addsock);
/*
* Create socket for RPC service.
*/
-static int svc_create_socket(struct svc_serv *serv, int protocol,
- struct sockaddr *sin, int len, int flags)
+static struct svc_xprt *svc_create_socket(struct svc_serv *serv,
+ int protocol,
+ struct sockaddr *sin, int len,
+ int flags)
{
struct svc_sock *svsk;
struct socket *sock;
@@ -1830,13 +1859,13 @@ static int svc_create_socket(struct svc_serv *serv, int protocol,
if (protocol != IPPROTO_UDP && protocol != IPPROTO_TCP) {
printk(KERN_WARNING "svc: only UDP and TCP "
"sockets supported\n");
- return -EINVAL;
+ return ERR_PTR(-EINVAL);
}
type = (protocol == IPPROTO_UDP)? SOCK_DGRAM : SOCK_STREAM;

error = sock_create_kern(sin->sa_family, type, protocol, &sock);
if (error < 0)
- return error;
+ return ERR_PTR(error);

svc_reclassify_socket(sock);

@@ -1853,13 +1882,13 @@ static int svc_create_socket(struct svc_serv *serv, int protocol,

if ((svsk = svc_setup_socket(serv, sock, &error, flags)) != NULL) {
svc_sock_received(svsk);
- return ntohs(inet_sk(svsk->sk_sk)->sport);
+ return (struct svc_xprt *)svsk;
}

bummer:
dprintk("svc: svc_create_socket error = %d\n", -error);
sock_release(sock);
- return error;
+ return ERR_PTR(error);
}

/*
@@ -1970,15 +1999,15 @@ void svc_force_close_socket(struct svc_sock *svsk)
int svc_makesock(struct svc_serv *serv, int protocol, unsigned short port,
int flags)
{
- struct sockaddr_in sin = {
- .sin_family = AF_INET,
- .sin_addr.s_addr = INADDR_ANY,
- .sin_port = htons(port),
- };
-
dprintk("svc: creating socket proto = %d\n", protocol);
- return svc_create_socket(serv, protocol, (struct sockaddr *) &sin,
- sizeof(sin), flags);
+ switch (protocol) {
+ case IPPROTO_TCP:
+ return svc_create_xprt(serv, "tcp", port, flags);
+ case IPPROTO_UDP:
+ return svc_create_xprt(serv, "udp", port, flags);
+ default:
+ return -EINVAL;
+ }
}

/*