jffs2: summary support

This patch adds support for reading fs information from summary
node instead of scanning full eraseblock.

Signed-off-by: Ilya Yanok <yanok@emcraft.com>

1 files changed, 163 insertions, 0 deletions

diff --git a/fs/jffs2/summary.h b/fs/jffs2/summary.h
new file mode 100644
index 0000000..834933c
--- /dev/null
+++ b/fs/jffs2/summary.h
@@ -0,0 +1,163 @@
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright © 2004  Ferenc Havasi <havasi@inf.u-szeged.hu>,
+ *		     Zoltan Sogor <weth@inf.u-szeged.hu>,
+ *		     Patrik Kluba <pajko@halom.u-szeged.hu>,
+ *		     University of Szeged, Hungary
+ *
+ * For licensing information, see the file 'LICENCE' in this directory.
+ *
+ */
+
+#ifndef JFFS2_SUMMARY_H
+#define JFFS2_SUMMARY_H
+
+#define BLK_STATE_ALLFF		0
+#define BLK_STATE_CLEAN		1
+#define BLK_STATE_PARTDIRTY	2
+#define BLK_STATE_CLEANMARKER	3
+#define BLK_STATE_ALLDIRTY	4
+#define BLK_STATE_BADBLOCK	5
+
+#define JFFS2_SUMMARY_NOSUM_SIZE 0xffffffff
+#define JFFS2_SUMMARY_INODE_SIZE (sizeof(struct jffs2_sum_inode_flash))
+#define JFFS2_SUMMARY_DIRENT_SIZE(x) (sizeof(struct jffs2_sum_dirent_flash) + (x))
+#define JFFS2_SUMMARY_XATTR_SIZE (sizeof(struct jffs2_sum_xattr_flash))
+#define JFFS2_SUMMARY_XREF_SIZE (sizeof(struct jffs2_sum_xref_flash))
+
+/* Summary structures used on flash */
+
+struct jffs2_sum_unknown_flash
+{
+	__u16 nodetype;	/* node type */
+};
+
+struct jffs2_sum_inode_flash
+{
+	__u16 nodetype;	/* node type */
+	__u32 inode;		/* inode number */
+	__u32 version;	/* inode version */
+	__u32 offset;	/* offset on jeb */
+	__u32 totlen; 	/* record length */
+} __attribute__((packed));
+
+struct jffs2_sum_dirent_flash
+{
+	__u16 nodetype;	/* == JFFS_NODETYPE_DIRENT */
+	__u32 totlen;	/* record length */
+	__u32 offset;	/* offset on jeb */
+	__u32 pino;		/* parent inode */
+	__u32 version;	/* dirent version */
+	__u32 ino; 		/* == zero for unlink */
+	uint8_t nsize;		/* dirent name size */
+	uint8_t type;		/* dirent type */
+	uint8_t name[0];	/* dirent name */
+} __attribute__((packed));
+
+struct jffs2_sum_xattr_flash
+{
+	__u16 nodetype;	/* == JFFS2_NODETYPE_XATR */
+	__u32 xid;		/* xattr identifier */
+	__u32 version;	/* version number */
+	__u32 offset;	/* offset on jeb */
+	__u32 totlen;	/* node length */
+} __attribute__((packed));
+
+struct jffs2_sum_xref_flash
+{
+	__u16 nodetype;	/* == JFFS2_NODETYPE_XREF */
+	__u32 offset;	/* offset on jeb */
+} __attribute__((packed));
+
+union jffs2_sum_flash
+{
+	struct jffs2_sum_unknown_flash u;
+	struct jffs2_sum_inode_flash i;
+	struct jffs2_sum_dirent_flash d;
+	struct jffs2_sum_xattr_flash x;
+	struct jffs2_sum_xref_flash r;
+};
+
+/* Summary structures used in the memory */
+
+struct jffs2_sum_unknown_mem
+{
+	union jffs2_sum_mem *next;
+	__u16 nodetype;	/* node type */
+};
+
+struct jffs2_sum_inode_mem
+{
+	union jffs2_sum_mem *next;
+	__u16 nodetype;	/* node type */
+	__u32 inode;		/* inode number */
+	__u32 version;	/* inode version */
+	__u32 offset;	/* offset on jeb */
+	__u32 totlen; 	/* record length */
+} __attribute__((packed));
+
+struct jffs2_sum_dirent_mem
+{
+	union jffs2_sum_mem *next;
+	__u16 nodetype;	/* == JFFS_NODETYPE_DIRENT */
+	__u32 totlen;	/* record length */
+	__u32 offset;	/* ofset on jeb */
+	__u32 pino;		/* parent inode */
+	__u32 version;	/* dirent version */
+	__u32 ino; 		/* == zero for unlink */
+	uint8_t nsize;		/* dirent name size */
+	uint8_t type;		/* dirent type */
+	uint8_t name[0];	/* dirent name */
+} __attribute__((packed));
+
+struct jffs2_sum_xattr_mem
+{
+	union jffs2_sum_mem *next;
+	__u16 nodetype;
+	__u32 xid;
+	__u32 version;
+	__u32 offset;
+	__u32 totlen;
+} __attribute__((packed));
+
+struct jffs2_sum_xref_mem
+{
+	union jffs2_sum_mem *next;
+	__u16 nodetype;
+	__u32 offset;
+} __attribute__((packed));
+
+union jffs2_sum_mem
+{
+	struct jffs2_sum_unknown_mem u;
+	struct jffs2_sum_inode_mem i;
+	struct jffs2_sum_dirent_mem d;
+	struct jffs2_sum_xattr_mem x;
+	struct jffs2_sum_xref_mem r;
+};
+
+/* Summary related information stored in superblock */
+
+struct jffs2_summary
+{
+	uint32_t sum_size;      /* collected summary information for nextblock */
+	uint32_t sum_num;
+	uint32_t sum_padded;
+	union jffs2_sum_mem *sum_list_head;
+	union jffs2_sum_mem *sum_list_tail;
+
+	__u32 *sum_buf;	/* buffer for writing out summary */
+};
+
+/* Summary marker is stored at the end of every sumarized erase block */
+
+struct jffs2_sum_marker
+{
+	__u32 offset;	/* offset of the summary node in the jeb */
+	__u32 magic; 	/* == JFFS2_SUM_MAGIC */
+};
+
+#define JFFS2_SUMMARY_FRAME_SIZE (sizeof(struct jffs2_raw_summary) + sizeof(struct jffs2_sum_marker))
+
+#endif /* JFFS2_SUMMARY_H */