[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>

1 files changed, 3 insertions, 1 deletions

diff --git a/include/linux/jffs2_fs_sb.h b/include/linux/jffs2_fs_sb.h
index 1e21546622de..5087612ed9ac 100644
--- a/include/linux/jffs2_fs_sb.h
+++ b/include/linux/jffs2_fs_sb.h
@@ -1,4 +1,4 @@
-/* $Id: jffs2_fs_sb.h,v 1.52 2005/05/19 16:12:17 gleixner Exp $ */
+/* $Id: jffs2_fs_sb.h,v 1.53 2005/09/07 08:34:56 havasi Exp $ */
 
 #ifndef _JFFS2_FS_SB
 #define _JFFS2_FS_SB
@@ -112,6 +112,8 @@ struct jffs2_sb_info {
         uint32_t fsdata_len;
 #endif
 
+        struct jffs2_summary *summary;          /* Summary information */
+
         /* OS-private pointer for getting back to master superblock info */
         void *os_priv;
 };