From: Trond Myklebust <trond.myklebust@fys.uio.no>
This patch makes the sunrpc XID identifier a per-transport socket
variable. Allows us to eliminate the global spinlock Olaf introduced...
---
include/linux/sunrpc/xprt.h | 6 +++++-
net/sunrpc/xprt.c | 27 +++++++++++----------------
2 files changed, 16 insertions(+), 17 deletions(-)
diff -puN include/linux/sunrpc/xprt.h~nfs-remove-XID-spinlock include/linux/sunrpc/xprt.h
--- 25/include/linux/sunrpc/xprt.h~nfs-remove-XID-spinlock 2004-02-28 18:21:15.000000000 -0800
+++ 25-akpm/include/linux/sunrpc/xprt.h 2004-02-28 18:21:15.000000000 -0800
@@ -102,7 +102,6 @@ struct rpc_rqst {
struct xdr_buf rq_private_buf; /* The receive buffer
* used in the softirq.
*/
-
/*
* For authentication (e.g. auth_des)
*/
@@ -155,6 +154,11 @@ struct rpc_xprt {
stream : 1; /* TCP */
/*
+ * XID
+ */
+ __u32 xid; /* Next XID value to use */
+
+ /*
* State of TCP reply receive stuff
*/
u32 tcp_recm, /* Fragment header */
diff -puN net/sunrpc/xprt.c~nfs-remove-XID-spinlock net/sunrpc/xprt.c
--- 25/net/sunrpc/xprt.c~nfs-remove-XID-spinlock 2004-02-28 18:21:15.000000000 -0800
+++ 25-akpm/net/sunrpc/xprt.c 2004-02-28 18:21:15.000000000 -0800
@@ -57,6 +57,7 @@
#include <linux/sunrpc/clnt.h>
#include <linux/file.h>
#include <linux/workqueue.h>
+#include <linux/random.h>
#include <net/sock.h>
#include <net/checksum.h>
@@ -1322,22 +1323,14 @@ do_xprt_reserve(struct rpc_task *task)
/*
* Allocate a 'unique' XID
*/
-static u32
-xprt_alloc_xid(void)
+static inline u32 xprt_alloc_xid(struct rpc_xprt *xprt)
{
- static spinlock_t xid_lock = SPIN_LOCK_UNLOCKED;
- static int need_init = 1;
- static u32 xid;
- u32 ret;
-
- spin_lock(&xid_lock);
- if (unlikely(need_init)) {
- xid = get_seconds() << 12;
- need_init = 0;
- }
- ret = xid++;
- spin_unlock(&xid_lock);
- return ret;
+ return xprt->xid++;
+}
+
+static inline void xprt_init_xid(struct rpc_xprt *xprt)
+{
+ get_random_bytes(&xprt->xid, sizeof(xprt->xid));
}
/*
@@ -1351,7 +1344,7 @@ xprt_request_init(struct rpc_task *task,
req->rq_timeout = xprt->timeout;
req->rq_task = task;
req->rq_xprt = xprt;
- req->rq_xid = xprt_alloc_xid();
+ req->rq_xid = xprt_alloc_xid(xprt);
INIT_LIST_HEAD(&req->rq_list);
dprintk("RPC: %4d reserved req %p xid %08x\n", task->tk_pid,
req, req->rq_xid);
@@ -1472,6 +1465,8 @@ xprt_setup(int proto, struct sockaddr_in
req->rq_next = NULL;
xprt->free = xprt->slot;
+ xprt_init_xid(xprt);
+
/* Check whether we want to use a reserved port */
xprt->resvport = capable(CAP_NET_BIND_SERVICE) ? 1 : 0;
_