2007-11-29 23:03:29

by Tom Tucker

[permalink] [raw]
Subject: [RFC,PATCH 36/38] svc: Add svc API that queries for a transport instance


Add a new svc function that allows a service to query whether a
transport instance has already been created. This is used in lockd
to determine whether or not a transport needs to be created when
a lockd instance is brought up.

Specifying 0 for the address family or port is effectively a wild-card,
and will result in matching the first transport in the service's list
that has a matching class name.

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

fs/lockd/svc.c | 16 ++--------------
include/linux/sunrpc/svc_xprt.h | 2 ++
net/sunrpc/svc_xprt.c | 31 +++++++++++++++++++++++++++++++
3 files changed, 35 insertions(+), 14 deletions(-)

diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index a8e79a9..470af01 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -219,18 +219,6 @@ lockd(struct svc_rqst *rqstp)
module_put_and_exit(0);
}

-static int find_xprt(struct svc_serv *serv, char *proto)
-{
- struct svc_xprt *xprt;
- int found = 0;
- list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list)
- if (strcmp(xprt->xpt_class->xcl_name, proto) == 0) {
- found = 1;
- break;
- }
- return found;
-}
-
/*
* Make any sockets that are needed but not present.
* If nlm_udpport or nlm_tcpport were set as module
@@ -242,11 +230,11 @@ static int make_socks(struct svc_serv *serv, int proto)
int err = 0;

if (proto == IPPROTO_UDP || nlm_udpport)
- if (!find_xprt(serv, "udp"))
+ if (!svc_find_xprt(serv, "udp", 0, 0))
err = svc_create_xprt(serv, "udp", nlm_udpport,
SVC_SOCK_DEFAULTS);
if (err >= 0 && (proto == IPPROTO_TCP || nlm_tcpport))
- if (!find_xprt(serv, "tcp"))
+ if (!svc_find_xprt(serv, "tcp", 0, 0))
err = svc_create_xprt(serv, "tcp", nlm_tcpport,
SVC_SOCK_DEFAULTS);

diff --git a/include/linux/sunrpc/svc_xprt.h b/include/linux/sunrpc/svc_xprt.h
index c2fa41d..30fcc82 100644
--- a/include/linux/sunrpc/svc_xprt.h
+++ b/include/linux/sunrpc/svc_xprt.h
@@ -80,6 +80,8 @@ void svc_xprt_enqueue(struct svc_xprt *xprt);
int svc_port_is_privileged(struct sockaddr *sin);
void svc_delete_xprt(struct svc_xprt *xprt);
int svc_print_xprts(char *buf, int maxlen);
+struct svc_xprt *
+svc_find_xprt(struct svc_serv *serv, char *xprt_class, int af, int port);

static inline void svc_xprt_get(struct svc_xprt *xprt)
{
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 7416e66..247f0fb 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -945,3 +945,34 @@ static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt)
spin_unlock(&xprt->xpt_lock);
return dr;
}
+
+/*
+ * Return the transport instance pointer for the endpoint accepting
+ * connections/peer traffic from the specified transport class,
+ * address family and port.
+ */
+struct svc_xprt *svc_find_xprt(struct svc_serv *serv, char *xcl_name,
+ int af, int port)
+{
+ struct svc_xprt *xprt;
+ struct svc_xprt *found = NULL;
+
+ /* Sanity check the args */
+ if (!serv || !xcl_name)
+ return found;
+
+ spin_lock_bh(&serv->sv_lock);
+ list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
+ if (strcmp(xprt->xpt_class->xcl_name, xcl_name))
+ continue;
+ if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family)
+ continue;
+ if (port && port != svc_xprt_local_port(xprt))
+ continue;
+ found = xprt;
+ break;
+ }
+ spin_unlock_bh(&serv->sv_lock);
+ return found;
+}
+EXPORT_SYMBOL_GPL(svc_find_xprt);