[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, 17 insertions, 9 deletions

diff --git a/fs/jffs2/gc.c b/fs/jffs2/gc.c
index def9715..ee54cdc 100644
--- a/fs/jffs2/gc.c
+++ b/fs/jffs2/gc.c
@@ -7,7 +7,7 @@
  *
  * For licensing information, see the file 'LICENCE' in this directory.
  *
- * $Id: gc.c,v 1.153 2005/08/17 13:46:22 dedekind Exp $
+ * $Id: gc.c,v 1.154 2005/09/07 08:34:54 havasi Exp $
  *
  */
 
@@ -513,8 +513,11 @@ static int jffs2_garbage_collect_pristine(struct jffs2_sb_info *c,
 	/* Ask for a small amount of space (or the totlen if smaller) because we
 	   don't want to force wastage of the end of a block if splitting would
 	   work. */
-	ret = jffs2_reserve_space_gc(c, min_t(uint32_t, sizeof(struct jffs2_raw_inode) + JFFS2_MIN_DATA_LEN, 
-					      rawlen), &phys_ofs, &alloclen);
+	ret = jffs2_reserve_space_gc(c, min_t(uint32_t, sizeof(struct jffs2_raw_inode) +
+				JFFS2_MIN_DATA_LEN, rawlen), &phys_ofs, &alloclen, rawlen);
+				/* this is not the exact summary size of it,
+					it is only an upper estimation */
+
 	if (ret)
 		return ret;
 
@@ -622,7 +625,9 @@ static int jffs2_garbage_collect_pristine(struct jffs2_sb_info *c,
 			jffs2_dbg_acct_sanity_check(c,jeb);
 			jffs2_dbg_acct_paranoia_check(c, jeb);
 
-			ret = jffs2_reserve_space_gc(c, rawlen, &phys_ofs, &dummy);
+			ret = jffs2_reserve_space_gc(c, rawlen, &phys_ofs, &dummy, rawlen);
+						/* this is not the exact summary size of it,
+							it is only an upper estimation */
 
 			if (!ret) {
 				D1(printk(KERN_DEBUG "Allocated space at 0x%08x to retry failed write.\n", phys_ofs));
@@ -701,7 +706,8 @@ static int jffs2_garbage_collect_metadata(struct jffs2_sb_info *c, struct jffs2_
 
 	}
 	
-	ret = jffs2_reserve_space_gc(c, sizeof(ri) + mdatalen, &phys_ofs, &alloclen);
+	ret = jffs2_reserve_space_gc(c, sizeof(ri) + mdatalen, &phys_ofs, &alloclen,
+				JFFS2_SUMMARY_INODE_SIZE);
 	if (ret) {
 		printk(KERN_WARNING "jffs2_reserve_space_gc of %zd bytes for garbage_collect_metadata failed: %d\n",
 		       sizeof(ri)+ mdatalen, ret);
@@ -781,7 +787,8 @@ static int jffs2_garbage_collect_dirent(struct jffs2_sb_info *c, struct jffs2_er
 	rd.node_crc = cpu_to_je32(crc32(0, &rd, sizeof(rd)-8));
 	rd.name_crc = cpu_to_je32(crc32(0, fd->name, rd.nsize));
 	
-	ret = jffs2_reserve_space_gc(c, sizeof(rd)+rd.nsize, &phys_ofs, &alloclen);
+	ret = jffs2_reserve_space_gc(c, sizeof(rd)+rd.nsize, &phys_ofs, &alloclen,
+				JFFS2_SUMMARY_DIRENT_SIZE(rd.nsize));
 	if (ret) {
 		printk(KERN_WARNING "jffs2_reserve_space_gc of %zd bytes for garbage_collect_dirent failed: %d\n",
 		       sizeof(rd)+rd.nsize, ret);
@@ -994,7 +1001,8 @@ static int jffs2_garbage_collect_hole(struct jffs2_sb_info *c, struct jffs2_eras
 	ri.data_crc = cpu_to_je32(0);
 	ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
 
-	ret = jffs2_reserve_space_gc(c, sizeof(ri), &phys_ofs, &alloclen);
+	ret = jffs2_reserve_space_gc(c, sizeof(ri), &phys_ofs, &alloclen,
+				JFFS2_SUMMARY_INODE_SIZE);
 	if (ret) {
 		printk(KERN_WARNING "jffs2_reserve_space_gc of %zd bytes for garbage_collect_hole failed: %d\n",
 		       sizeof(ri), ret);
@@ -1219,7 +1227,8 @@ static int jffs2_garbage_collect_dnode(struct jffs2_sb_info *c, struct jffs2_era
 		uint32_t cdatalen;
 		uint16_t comprtype = JFFS2_COMPR_NONE;
 
-		ret = jffs2_reserve_space_gc(c, sizeof(ri) + JFFS2_MIN_DATA_LEN, &phys_ofs, &alloclen);
+		ret = jffs2_reserve_space_gc(c, sizeof(ri) + JFFS2_MIN_DATA_LEN, &phys_ofs,
+					&alloclen, JFFS2_SUMMARY_INODE_SIZE);
 
 		if (ret) {
 			printk(KERN_WARNING "jffs2_reserve_space_gc of %zd bytes for garbage_collect_dnode failed: %d\n",
@@ -1276,4 +1285,3 @@ static int jffs2_garbage_collect_dnode(struct jffs2_sb_info *c, struct jffs2_era
 	jffs2_gc_release_page(c, pg_ptr, &pg);
 	return ret;
 }
-