[PATCH] RPC: allow RPC client's port range to be adjustable

 Select an RPC client source port between 650 and 1023 instead of between
 1 and 800.  The old range conflicts with a number of network services.
 Provide sysctls to allow admins to select a different port range.

 Note that this doesn't affect user-level RPC library behavior, which
 still uses 1 to 800.

 Based on a suggestion by Olaf Kirch <okir@suse.de>.

 Test-plan:
 Repeated mount and unmount.  Destructive testing.  Idle timeouts.

 Signed-off-by: Chuck Lever <cel@netapp.com>
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

2 files changed, 16 insertions, 3 deletions

diff --git a/include/linux/sunrpc/debug.h b/include/linux/sunrpc/debug.h
index 42d299747956..1a42d902bc11 100644
--- a/include/linux/sunrpc/debug.h
+++ b/include/linux/sunrpc/debug.h
@@ -95,6 +95,8 @@ enum {
         CTL_NLMDEBUG,
         CTL_SLOTTABLE_UDP,
         CTL_SLOTTABLE_TCP,
+        CTL_MIN_RESVPORT,
+        CTL_MAX_RESVPORT,
 };
 
 #endif /* _LINUX_SUNRPC_DEBUG_H_ */
diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index dcf0326bda01..9d9266cf8a36 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -52,6 +52,17 @@ extern unsigned int xprt_tcp_slot_table_entries;
 #define RPC_REPHDRSIZE          4
 
 /*
+ * Parameters for choosing a free port
+ */
+extern unsigned int xprt_min_resvport;
+extern unsigned int xprt_max_resvport;
+
+#define RPC_MIN_RESVPORT        (1U)
+#define RPC_MAX_RESVPORT        (65535U)
+#define RPC_DEF_MIN_RESVPORT    (650U)
+#define RPC_DEF_MAX_RESVPORT    (1023U)
+
+/*
  * This describes a timeout strategy
  */
 struct rpc_timeout {
@@ -62,6 +73,9 @@ struct rpc_timeout {
         unsigned char           to_exponential;
 };
 
+struct rpc_task;
+struct rpc_xprt;
+
 /*
  * This describes a complete RPC request
  */
@@ -107,9 +121,6 @@ struct rpc_rqst {
 #define rq_svec                 rq_snd_buf.head
 #define rq_slen                 rq_snd_buf.len
 
-struct rpc_task;
-struct rpc_xprt;
-
 struct rpc_xprt_ops {
         void            (*set_buffer_size)(struct rpc_xprt *xprt);
         int             (*reserve_xprt)(struct rpc_task *task);