[PATCH] uml: mconsole locking

Locking fixes.  Locking was totally lacking for the mconsole_devices, which
got a spin lock, and the unplugged pages data, which got a mutex.

The locking of the mconsole console output code was confused.  Now, the
console_lock (renamed to client_lock) protects the clients list.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index f4db97e..c1d40fb 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -828,6 +828,7 @@
  * ubd-specific locks.
  */
 static struct mc_device ubd_mc = {
+	.list		= LIST_HEAD_INIT(ubd_mc.list),
 	.name		= "ubd",
 	.config		= ubd_config,
  	.get_config	= ubd_get_config,