[JFFS2] Add erase block summary support (mount time improvement)

The goal of summary is to speed up the mount time. Erase block summary (EBS)
stores summary information at the end of every (closed) erase block. It is
no longer necessary to scan all nodes separetly (and read all pages of them)
just read this "small" summary, where every information is stored which is
needed at mount time.

This summary information is stored in a JFFS2_FEATURE_RWCOMPAT_DELETE. During
the mount process if there is no summary info the orignal scan process will
be executed. EBS works with NAND and NOR flashes, too.

There is a user space tool called sumtool to generate this summary
information for a JFFS2 image.

Signed-off-by: Ferenc Havasi <havasi@inf.u-szeged.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

fs/jffs2/debug.h

@@ -7,7 +7,7 @@
  *
  * For licensing information, see the file 'LICENCE' in this directory.
  *
- * $Id: debug.h,v 1.14 2005/08/17 13:48:59 dedekind Exp $
+ * $Id: debug.h,v 1.15 2005/09/07 08:34:54 havasi Exp $
  *
  */
 #ifndef _JFFS2_DEBUG_H_
@@ -28,6 +28,7 @@
 #define JFFS2_DBG_DENTLIST_MESSAGES
 #define JFFS2_DBG_NODEREF_MESSAGES
 #define JFFS2_DBG_INOCACHE_MESSAGES
+#define JFFS2_DBG_SUMMARY_MESSAGES
 #endif
 
 #if CONFIG_JFFS2_FS_DEBUG == 2
@@ -137,6 +138,13 @@
 #define JFFS2_DBG_INOCACHE(fmt, ...)
 #endif
 
+/* Summary debugging messages */
+#ifdef JFFS2_DBG_SUMMARY_MESSAGES
+#define JFFS2_DBG_SUMMARY(fmt, ...)	JFFS2_DEBUG(fmt, ##__VA_ARGS__)
+#else
+#define JFFS2_DBG_SUMMARY(fmt, ...)
+#endif
+
 /* Watch the object allocations */
 #ifdef JFFS2_DBG_MEMALLOC_MESSAGES
 #define JFFS2_DBG_MEMALLOC(fmt, ...)	JFFS2_DEBUG(fmt, ##__VA_ARGS__)