From 058a171b705174bb9ae6f3f008df608867d6f637 Mon Sep 17 00:00:00 2001
From: Michael Vrable <mvrable@cs.ucsd.edu>
Date: Mon, 1 Feb 2010 09:38:25 -0800
Subject: [PATCH] SIGUSR1 causes nfsd to dump filesystem state now for
 debugging.

---
 nfs3/rpc.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/nfs3/rpc.c b/nfs3/rpc.c
index 2c640d7..a807022 100644
--- a/nfs3/rpc.c
+++ b/nfs3/rpc.c
@@ -18,6 +18,7 @@
 #include <stdlib.h>
 #include <rpc/pmap_clnt.h>
 #include <string.h>
+#include <signal.h>
 #include <memory.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
@@ -518,8 +519,22 @@ static GMainLoop *main_loop;
 
 static GThreadPool *rpc_thread_pool;
 
+static volatile int fs_dump_requested = 0;
+
+static void sig_handler(int sig)
+{
+    if (sig == SIGUSR1) {
+        fs_dump_requested = 1;
+    }
+}
+
 static gboolean async_flushd(gpointer data)
 {
+    if (fs_dump_requested) {
+        bluesky_debug_dump(fs);
+        fs_dump_requested = 0;
+    }
+
     bluesky_flushd_invoke(fs);
     return TRUE;
 }
@@ -541,6 +556,15 @@ static async_rpc_init()
     g_source_set_callback(source, async_flushd, NULL, NULL);
     g_source_attach(source, main_context);
     g_source_unref(source);
+
+    /* Signal USR1 is used to request a debugging dump of filesyste info */
+    struct sigaction sa;
+    sa.sa_handler = sig_handler;
+    sigemptyset(&sa.sa_mask);
+    sa.sa_flags = SA_RESTART;
+    if (sigaction(SIGUSR1, &sa, NULL) < 0) {
+        perror("sigaction");
+    }
 }
 
 struct rpc_call_header {
-- 
2.20.1