[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, 9 insertions, 3 deletions

diff --git a/fs/jffs2/wbuf.c b/fs/jffs2/wbuf.c
index 8c06d3a..86860db 100644
--- a/fs/jffs2/wbuf.c
+++ b/fs/jffs2/wbuf.c
@@ -9,7 +9,7 @@
  *
  * For licensing information, see the file 'LICENCE' in this directory.
  *
- * $Id: wbuf.c,v 1.97 2005/08/06 04:51:30 nico Exp $
+ * $Id: wbuf.c,v 1.98 2005/09/07 08:34:55 havasi Exp $
  *
  */
 
@@ -265,7 +265,7 @@ static void jffs2_wbuf_recover(struct jffs2_sb_info *c)
 
 
 	/* ... and get an allocation of space from a shiny new block instead */
-	ret = jffs2_reserve_space_gc(c, end-start, &ofs, &len);
+	ret = jffs2_reserve_space_gc(c, end-start, &ofs, &len, JFFS2_SUMMARY_NOSUM_SIZE);
 	if (ret) {
 		printk(KERN_WARNING "Failed to allocate space for wbuf recovery. Data loss ensues.\n");
 		kfree(buf);
@@ -836,6 +836,12 @@ int jffs2_flash_writev(struct jffs2_sb_info *c, const struct kvec *invecs, unsig
 alldone:
 	*retlen = donelen;
 
+	if (jffs2_sum_active()) {
+		int res = jffs2_sum_add_kvec(c, invecs, count, (uint32_t) to);
+		if (res)
+			return res;
+	}
+
 	if (c->wbuf_len && ino)
 		jffs2_wbuf_dirties_inode(c, ino);
 
@@ -855,7 +861,7 @@ int jffs2_flash_write(struct jffs2_sb_info *c, loff_t ofs, size_t len, size_t *r
 	struct kvec vecs[1];
 
 	if (!jffs2_is_writebuffered(c))
-		return c->mtd->write(c->mtd, ofs, len, retlen, buf);
+		return jffs2_flash_direct_write(c, ofs, len, retlen, buf);
 
 	vecs[0].iov_base = (unsigned char *) buf;
 	vecs[0].iov_len = len;