fast-clean-shutdown-04.09.02.patch: 

This patch provides a fast system shutdown by freezing all processes, remounting
all filesystems as read-only, closing all TCP connectinons, then powering down.

Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com> for CELF
---

 kernel/power/Kconfig |    5 ++++
 kernel/power/main.c  |   61 +++++++++++++++++++++++++++++++++++++++++++++++++++
 net/ipv4/tcp.c       |   41 ++++++++++++++++++++++++++++++++++
 3 files changed, 107 insertions(+)


diff -ruN -X ./dontdiff tag_FAST_CLEAN_SHUTDOWN_BASE/kernel/power/Kconfig branch_FAST_CLEAN_SHUTDOWN/kernel/power/Kconfig
--- tag_FAST_CLEAN_SHUTDOWN_BASE/kernel/power/Kconfig	2004-09-02 15:18:19.000000000 -0700
+++ branch_FAST_CLEAN_SHUTDOWN/kernel/power/Kconfig	2004-09-02 15:20:54.000000000 -0700
@@ -24,6 +24,11 @@
 	---help---
 	Mark Filesytem states clean on Suspend.
 
+config FAST_CLEAN_SHUTDOWN
+	bool "Fast & Clean Shutdown (EXPERIMENTAL)"
+	depends on SAFE_SUSPEND
+	---help---
+	  Mark file system states clean and close tcp connections on shutdown.
 
 config SOFTWARE_SUSPEND
 	bool "Software Suspend (EXPERIMENTAL)"
diff -ruN -X ./dontdiff tag_FAST_CLEAN_SHUTDOWN_BASE/kernel/power/main.c branch_FAST_CLEAN_SHUTDOWN/kernel/power/main.c
--- tag_FAST_CLEAN_SHUTDOWN_BASE/kernel/power/main.c	2004-09-02 15:18:19.000000000 -0700
+++ branch_FAST_CLEAN_SHUTDOWN/kernel/power/main.c	2004-09-02 15:20:54.000000000 -0700
@@ -251,8 +251,69 @@
 
 power_attr(state);
 
+#ifdef CONFIG_FAST_CLEAN_SHUTDOWN
+
+#include <linux/reboot.h>
+#include <linux/fs.h>
+
+extern void tcp_shutdown_all(void); 
+
+void fast_clean_shutdown(int fake_level)
+{
+	(void)freeze_processes();
+	(void) suspend_remount();
+	tcp_shutdown_all();
+
+	if (fake_level)
+		return;
+
+	device_shutdown(); /* try to flush cache on device side */
+	machine_power_off();
+
+	panic("fast_shutdown: can't power off\n");
+
+	/* NOTREACHED */
+
+}
+
+static ssize_t fast_clean_shutdown_show(struct subsystem * subsys, char * buf)
+{
+	return sprintf(buf,"enabled\n");
+}
+
+static ssize_t fast_clean_shutdown_store(struct subsystem * subsys, const char * buf,
+				  size_t n)
+{
+
+	int fake_level;
+	char c;
+
+	if (n>2) 
+		return -EINVAL;
+	c = buf[1];
+	if (c!='\0' && c!='\n')
+		return -EINVAL;
+
+	c = buf[0];
+	if (c == '0' || buf[0] == 'n' ) 
+		return n; /* real fake */
+
+	fake_level = (buf[0] == '1' || buf[0] == 'y')  ? 0 : 1;
+	fast_clean_shutdown(fake_level);
+
+	return n;
+}
+
+power_attr(fast_clean_shutdown);
+
+
+#endif /* CONFIG_FAST_CLEAN_SHUTDOWN */
+
 static struct attribute * g[] = {
 	&state_attr.attr,
+#ifdef CONFIG_FAST_CLEAN_SHUTDOWN
+	&fast_clean_shutdown_attr.attr,
+#endif
 	NULL,
 };
 
diff -ruN -X ./dontdiff tag_FAST_CLEAN_SHUTDOWN_BASE/net/ipv4/tcp.c branch_FAST_CLEAN_SHUTDOWN/net/ipv4/tcp.c
--- tag_FAST_CLEAN_SHUTDOWN_BASE/net/ipv4/tcp.c	2004-09-02 15:18:19.000000000 -0700
+++ branch_FAST_CLEAN_SHUTDOWN/net/ipv4/tcp.c	2004-09-02 15:21:00.000000000 -0700
@@ -2186,6 +2186,47 @@
 	return 0;
 }
 
+#ifdef CONFIG_FAST_CLEAN_SHUTDOWN
+
+void tcp_shutdown_all(void)
+{
+	int bucket;
+
+	for (bucket = 0; bucket < tcp_ehash_size; ++bucket) {
+		struct sock *sk;
+		struct hlist_node *node, *t;
+	       
+		read_lock(&tcp_ehash[bucket].lock);
+		sk_for_each_safe(sk, node, t, &tcp_ehash[bucket].chain) {
+			read_unlock(&tcp_ehash[bucket].lock);
+
+			switch(sk->sk_family) {
+			  case PF_INET:
+				if (LOOPBACK(htonl(inet_sk(sk)->daddr)))
+					continue;
+			  	break;
+#ifdef CONFIG_IPV6
+			  case PF_INET6:
+				if (ipv6_addr_type(&inet6_sk(sk)->daddr)
+					& IPV6_ADDR_LOOPBACK)
+						continue;
+			  	break;
+#endif
+			  default:
+			  	continue;
+			}
+
+			tcp_shutdown(sk, SEND_SHUTDOWN);
+
+			read_lock(&tcp_ehash[bucket].lock);
+		}
+		read_unlock(&tcp_ehash[bucket].lock);
+
+	}
+}
+
+#endif /* CONFIG_FAST_CLEAN_SHUTDOWN */
+
 
 extern void __skb_cb_too_small_for_tcp(int, int);
 extern void tcpdiag_init(void);