[PATCH] fault-injection capabilities infrastructure

This patch provides base functions implement to fault-injection
capabilities.

- The function should_fail() is taken from failmalloc-1.0
  (http://www.nongnu.org/failmalloc/)

[akpm@osdl.org: cleanups, comments, add __init]
Cc: <okuji@enbug.org>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Don Mullis <dwm@meer.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

lib/Kconfig.debug

@@ -413,3 +413,15 @@ config LKDTM
 
 	Documentation on how to use the module can be found in
 	drivers/misc/lkdtm.c
+
+config FAULT_INJECTION
+	bool
+
+config FAULT_INJECTION_DEBUG_FS
+	bool "Debugfs entries for fault-injection capabilities"
+	depends on FAULT_INJECTION && SYSFS
+	select DEBUG_FS
+	help
+	  This option enable configuration of fault-injection capabilities via
+	  debugfs.
+