[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/Kconfig

@@ -1050,6 +1050,19 @@ config JFFS2_FS_WRITEBUFFER
 	    - NOR flash with transparent ECC
 	    - DataFlash
 
+config JFFS2_SUMMARY
+	bool "JFFS2 summary support (EXPERIMENTAL)"
+	depends on JFFS2_FS && EXPERIMENTAL
+	default n
+	help
+	  This feature makes it possible to use summary information
+	  for faster filesystem mount.
+
+	  The summary information can be inserted into a filesystem image
+	  by the utility 'sumtool'.
+
+	  If unsure, say 'N'.
+
 config JFFS2_COMPRESSION_OPTIONS
 	bool "Advanced compression options for JFFS2"
 	depends on JFFS2_FS

fs/jffs2/Makefile

@@ -1,7 +1,7 @@
 #
 # Makefile for the Linux Journalling Flash File System v2 (JFFS2)
 #
-# $Id: Makefile.common,v 1.10 2005/07/17 06:56:20 dedekind Exp $
+# $Id: Makefile.common,v 1.11 2005/09/07 08:34:53 havasi Exp $
 #
 
 obj-$(CONFIG_JFFS2_FS) += jffs2.o
@@ -15,3 +15,4 @@ jffs2-$(CONFIG_JFFS2_FS_WRITEBUFFER)	+= wbuf.o
 jffs2-$(CONFIG_JFFS2_RUBIN)	+= compr_rubin.o
 jffs2-$(CONFIG_JFFS2_RTIME)	+= compr_rtime.o
 jffs2-$(CONFIG_JFFS2_ZLIB)	+= compr_zlib.o
+jffs2-$(CONFIG_JFFS2_SUMMARY)   += summary.o

fs/jffs2/build.c

@@ -7,7 +7,7 @@
  *
  * For licensing information, see the file 'LICENCE' in this directory.
  *
- * $Id: build.c,v 1.77 2005/08/31 13:51:00 havasi Exp $
+ * $Id: build.c,v 1.78 2005/09/07 08:34:54 havasi Exp $
  *
  */
 
@@ -350,18 +350,22 @@ int jffs2_do_mount_fs(struct jffs2_sb_info *c)
 	INIT_LIST_HEAD(&c->bad_list);
 	INIT_LIST_HEAD(&c->bad_used_list);
 	c->highest_ino = 1;
+	c->summary = NULL;
+
+	if (jffs2_sum_init(c))
+		return -ENOMEM;
 
 	if (jffs2_build_filesystem(c)) {
 		D1(printk(KERN_DEBUG "build_fs failed\n"));
 		jffs2_free_ino_caches(c);
 		jffs2_free_raw_node_refs(c);
 #ifndef __ECOS
 		if (jffs2_blocks_use_vmalloc(c))
-                    vfree(c->blocks);
+			vfree(c->blocks);
 		else 
 #endif
-                    kfree(c->blocks);
-		
+			kfree(c->blocks);
+
 		return -EIO;
 	}
 

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__)

fs/jffs2/dir.c

@@ -7,7 +7,7 @@
  *
  * For licensing information, see the file 'LICENCE' in this directory.
  *
- * $Id: dir.c,v 1.88 2005/08/17 13:46:22 dedekind Exp $
+ * $Id: dir.c,v 1.89 2005/09/07 08:34:54 havasi Exp $
  *
  */
 
@@ -310,7 +310,8 @@ static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char
 	 * Just the node will do for now, though 
 	 */
 	namelen = dentry->d_name.len;
-	ret = jffs2_reserve_space(c, sizeof(*ri) + targetlen, &phys_ofs, &alloclen, ALLOC_NORMAL);
+	ret = jffs2_reserve_space(c, sizeof(*ri) + targetlen, &phys_ofs, &alloclen,
+				ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
 
 	if (ret) {
 		jffs2_free_raw_inode(ri);
@@ -370,7 +371,8 @@ static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char
 	up(&f->sem);
 
 	jffs2_complete_reservation(c);
-	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &phys_ofs, &alloclen, ALLOC_NORMAL);
+	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &phys_ofs, &alloclen,
+				ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
 	if (ret) {
 		/* Eep. */
 		jffs2_clear_inode(inode);
@@ -455,7 +457,8 @@ static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, int mode)
 	 * Just the node will do for now, though 
 	 */
 	namelen = dentry->d_name.len;
-	ret = jffs2_reserve_space(c, sizeof(*ri), &phys_ofs, &alloclen, ALLOC_NORMAL);
+	ret = jffs2_reserve_space(c, sizeof(*ri), &phys_ofs, &alloclen, ALLOC_NORMAL,
+				JFFS2_SUMMARY_INODE_SIZE);
 
 	if (ret) {
 		jffs2_free_raw_inode(ri);
@@ -498,7 +501,8 @@ static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, int mode)
 	up(&f->sem);
 
 	jffs2_complete_reservation(c);
-	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &phys_ofs, &alloclen, ALLOC_NORMAL);
+	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &phys_ofs, &alloclen,
+				ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
 	if (ret) {
 		/* Eep. */
 		jffs2_clear_inode(inode);
@@ -607,7 +611,8 @@ static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, int mode, de
 	 * Just the node will do for now, though 
 	 */
 	namelen = dentry->d_name.len;
-	ret = jffs2_reserve_space(c, sizeof(*ri) + devlen, &phys_ofs, &alloclen, ALLOC_NORMAL);
+	ret = jffs2_reserve_space(c, sizeof(*ri) + devlen, &phys_ofs, &alloclen,
+				ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
 
 	if (ret) {
 		jffs2_free_raw_inode(ri);
@@ -652,7 +657,8 @@ static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, int mode, de
 	up(&f->sem);
 
 	jffs2_complete_reservation(c);
-	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &phys_ofs, &alloclen, ALLOC_NORMAL);
+	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &phys_ofs, &alloclen,
+				ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
 	if (ret) {
 		/* Eep. */
 		jffs2_clear_inode(inode);

fs/jffs2/file.c

@@ -7,7 +7,7 @@
  *
  * For licensing information, see the file 'LICENCE' in this directory.
  *
- * $Id: file.c,v 1.102 2005/07/06 12:13:09 dwmw2 Exp $
+ * $Id: file.c,v 1.103 2005/09/07 08:34:54 havasi Exp $
  *
  */
 
@@ -134,7 +134,8 @@ static int jffs2_prepare_write (struct file *filp, struct page *pg,
 		D1(printk(KERN_DEBUG "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
 			  (unsigned int)inode->i_size, pageofs));
 
-		ret = jffs2_reserve_space(c, sizeof(ri), &phys_ofs, &alloc_len, ALLOC_NORMAL);
+		ret = jffs2_reserve_space(c, sizeof(ri), &phys_ofs, &alloc_len,
+					ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
 		if (ret)
 			return ret;
 

fs/jffs2/fs.c

@@ -7,7 +7,7 @@
  *
  * For licensing information, see the file 'LICENCE' in this directory.
  *
- * $Id: fs.c,v 1.64 2005/09/01 08:42:31 havasi Exp $
+ * $Id: fs.c,v 1.65 2005/09/07 08:34:54 havasi Exp $
  *
  */
 
@@ -74,7 +74,8 @@ static int jffs2_do_setattr (struct inode *inode, struct iattr *iattr)
 		return -ENOMEM;
 	}
 
-	ret = jffs2_reserve_space(c, sizeof(*ri) + mdatalen, &phys_ofs, &alloclen, ALLOC_NORMAL);
+	ret = jffs2_reserve_space(c, sizeof(*ri) + mdatalen, &phys_ofs, &alloclen,
+				ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
 	if (ret) {
 		jffs2_free_raw_inode(ri);
 		if (S_ISLNK(inode->i_mode & S_IFMT))

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;
 }
-

fs/jffs2/nodelist.h

@@ -7,7 +7,7 @@
  *
  * For licensing information, see the file 'LICENCE' in this directory.
  *
- * $Id: nodelist.h,v 1.139 2005/08/31 13:51:00 havasi Exp $
+ * $Id: nodelist.h,v 1.140 2005/09/07 08:34:54 havasi Exp $
  *
  */
 
@@ -20,6 +20,7 @@
 #include <linux/jffs2.h>
 #include <linux/jffs2_fs_sb.h>
 #include <linux/jffs2_fs_i.h>
+#include "summary.h"
 
 #ifdef __ECOS
 #include "os-ecos.h"
@@ -326,8 +327,10 @@ int jffs2_add_older_frag_to_fragtree(struct jffs2_sb_info *c, struct jffs2_inode
 
 /* nodemgmt.c */
 int jffs2_thread_should_wake(struct jffs2_sb_info *c);
-int jffs2_reserve_space(struct jffs2_sb_info *c, uint32_t minsize, uint32_t *ofs, uint32_t *len, int prio);
-int jffs2_reserve_space_gc(struct jffs2_sb_info *c, uint32_t minsize, uint32_t *ofs, uint32_t *len);
+int jffs2_reserve_space(struct jffs2_sb_info *c, uint32_t minsize, uint32_t *ofs,
+			uint32_t *len, int prio, uint32_t sumsize);
+int jffs2_reserve_space_gc(struct jffs2_sb_info *c, uint32_t minsize, uint32_t *ofs,
+			uint32_t *len, uint32_t sumsize);
 int jffs2_add_physical_node_ref(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *new);
 void jffs2_complete_reservation(struct jffs2_sb_info *c);
 void jffs2_mark_node_obsolete(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *raw);
@@ -386,6 +389,10 @@ char *jffs2_getlink(struct jffs2_sb_info *c, struct jffs2_inode_info *f);
 /* scan.c */
 int jffs2_scan_medium(struct jffs2_sb_info *c);
 void jffs2_rotate_lists(struct jffs2_sb_info *c);
+int jffs2_fill_scan_buf(struct jffs2_sb_info *c, void *buf,
+				uint32_t ofs, uint32_t len);
+struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino);
+int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb);
 
 /* build.c */
 int jffs2_do_mount_fs(struct jffs2_sb_info *c);