From jaegeuk.kim@samsung.com Mon Oct 22 19:26:03 2012
From: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Date: Tue, 23 Oct 2012 11:26:00 +0900
Subject: [PATCH 02/16 v2] f2fs: add on-disk layout
To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, viro@zeniv.linux.org.uk, arnd@arndb.de, tytso@mit.edu, chur.lee@samsung.com, cm224.lee@samsung.com, jooyoung.hwang@samsung.com
Message-ID: <001201cdb0c5$bdf728f0$39e57ad0$%kim@samsung.com>


This adds a header file describing the on-disk layout of f2fs.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Chul Lee <chur.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
---
 include/linux/f2fs_fs.h |  362 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 362 insertions(+)
 create mode 100644 include/linux/f2fs_fs.h

diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
new file mode 100644
index 0000000..bd9c217
--- /dev/null
+++ b/include/linux/f2fs_fs.h
@@ -0,0 +1,362 @@
+/**
+ * include/linux/f2fs_fs.h
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef _LINUX_F2FS_FS_H
+#define _LINUX_F2FS_FS_H
+
+#include <linux/pagemap.h>
+#include <linux/types.h>
+
+#define F2FS_SUPER_MAGIC	0xF2F52010
+#define F2FS_SUPER_OFFSET	0		/* start sector # for sb */
+#define F2FS_BLKSIZE		4096
+#define F2FS_MAX_EXTENSION	64
+
+#define NULL_ADDR		0x0U
+#define NEW_ADDR		-1U
+
+#define F2FS_ROOT_INO(sbi)	(sbi->root_ino_num)
+#define F2FS_NODE_INO(sbi)	(sbi->node_ino_num)
+#define F2FS_META_INO(sbi)	(sbi->meta_ino_num)
+
+#define GFP_F2FS_MOVABLE	(__GFP_WAIT | __GFP_IO | __GFP_ZERO)
+
+#define MAX_ACTIVE_LOGS	16
+#define MAX_ACTIVE_NODE_LOGS	8
+#define MAX_ACTIVE_DATA_LOGS	8
+
+/*
+ * For superblock
+ */
+struct f2fs_super_block {
+	__le32 magic;		/* Magic Number */
+	__le16 major_ver;	/* Major Version */
+	__le16 minor_ver;	/* Minor Version */
+	__le32 log_sectorsize;	/* log2 (Sector size in bytes) */
+	__le32 log_sectors_per_block;	/* log2 (Number of sectors per block */
+	__le32 log_blocksize;	/* log2 (Block size in bytes) */
+	__le32 log_blocks_per_seg; /* log2 (Number of blocks per segment) */
+	__le32 segs_per_sec;	/* Number of segments per section */
+	__le32 secs_per_zone;	/* Number of sections per zone */
+	__le32 checksum_offset;	/* Checksum position in this super block */
+	__le64 block_count;	/* Total number of blocks */
+	__le32 section_count;	/* Total number of sections */
+	__le32 segment_count;	/* Total number of segments */
+	__le32 segment_count_ckpt; /* Total number of segments
+				      in Checkpoint area */
+	__le32 segment_count_sit; /* Total number of segments
+				     in Segment information table */
+	__le32 segment_count_nat; /* Total number of segments
+				     in Node address table */
+	/*Total number of segments in Segment summary area */
+	__le32 segment_count_ssa;
+	/* Total number of segments in Main area */
+	__le32 segment_count_main;
+	__le32 failure_safe_block_distance;
+	__le32 segment0_blkaddr;	/* Start block address of Segment 0 */
+	__le32 start_segment_checkpoint; /* Start block address of ckpt */
+	__le32 sit_blkaddr;	/* Start block address of SIT */
+	__le32 nat_blkaddr;	/* Start block address of NAT */
+	__le32 ssa_blkaddr;     /* Start block address of SSA */
+	__le32 main_blkaddr;	/* Start block address of Main area */
+	__le32 root_ino;	/* Root directory inode number */
+	__le32 node_ino;	/* node inode number */
+	__le32 meta_ino;	/* meta inode number */
+	__le32 volume_serial_number;	/* VSN is optional field */
+	__le16 volume_name[512];	/* Volume Name */
+	__le32 extension_count;
+	__u8 extension_list[F2FS_MAX_EXTENSION][8]; /* extension array */
+} __packed;
+
+/*
+ * For checkpoint
+ */
+struct f2fs_checkpoint {
+	__le64 checkpoint_ver;		/* Checkpoint block version number */
+	__le64 user_block_count;	/* # of user blocks */
+	__le64 valid_block_count;	/* # of valid blocks in Main area */
+	__le32 rsvd_segment_count;	/* # of reserved segments for gc */
+	__le32 overprov_segment_count;	/* # of overprovision segments */
+	__le32 free_segment_count;	/* # of free segments in Main area */
+
+	/* information of current node segments */
+	__le32 cur_node_segno[MAX_ACTIVE_NODE_LOGS];
+	__le16 cur_node_blkoff[MAX_ACTIVE_NODE_LOGS];
+	__le16 nat_upd_blkoff[MAX_ACTIVE_NODE_LOGS];
+	/* information of current data segments */
+	__le32 cur_data_segno[MAX_ACTIVE_DATA_LOGS];
+	__le16 cur_data_blkoff[MAX_ACTIVE_DATA_LOGS];
+	__le32 ckpt_flags;		/* Flags : umount and journal_present */
+	__le32 cp_pack_total_block_count;
+	__le32 cp_pack_start_sum;	/* start block number of data summary */
+	__le32 valid_node_count;	/* Total number of valid nodes */
+	__le32 valid_inode_count;	/* Total number of valid inodes */
+	__le32 next_free_nid;		/* Next free node number */
+	__le32 sit_ver_bitmap_bytesize;	/* Default value 64 */
+	__le32 nat_ver_bitmap_bytesize; /* Default value 256 */
+	__le32 checksum_offset;		/* Checksum position
+					   in this checkpoint block */
+	__le64 elapsed_time;		/* elapsed time while partition
+					   is mounted */
+	/* allocation type of current segment */
+	unsigned char alloc_type[MAX_ACTIVE_LOGS];
+
+	/* SIT and NAT version bitmap */
+	unsigned char sit_nat_version_bitmap[1];
+} __packed;
+
+/*
+ * For orphan inode management
+ */
+#define F2FS_ORPHANS_PER_BLOCK	1020
+
+struct f2fs_orphan_block {
+	__le32 ino[F2FS_ORPHANS_PER_BLOCK];	/* inode numbers */
+	__le32 reserved;
+	__le16 blk_addr;	/* block index in current CP */
+	__le16 blk_count;	/* Number of orphan inode blocks in CP */
+	__le32 entry_count;	/* Total number of orphan nodes in current CP */
+	__le32 check_sum;	/* CRC32 for orphan inode block */
+} __packed;
+
+/*
+ * For NODE structure
+ */
+struct f2fs_extent {
+	__le32 fofs;
+	__le32 blk_addr;
+	__le32 len;
+} __packed;
+
+#define F2FS_MAX_NAME_LEN	256
+#define ADDRS_PER_INODE         927	/* Address Pointers in an Inode */
+#define ADDRS_PER_BLOCK         1018	/* Address Pointers in a Direct Block */
+#define NIDS_PER_BLOCK          1018	/* Node IDs in an Indirect Block */
+
+struct f2fs_inode {
+	__le16 i_mode;			/* File mode */
+	__u8 i_advise;			/* File hints */
+	__u8 i_reserved;		/* Reserved */
+	__le32 i_uid;			/* User ID */
+	__le32 i_gid;			/* Group ID */
+	__le32 i_links;			/* Links count */
+	__le64 i_size;			/* File size in bytes */
+	__le64 i_blocks;		/* File size in blocks */
+	__le64 i_ctime;			/* Inode change time */
+	__le64 i_mtime;			/* Modification time */
+	__le32 i_ctime_nsec;
+	__le32 i_mtime_nsec;
+	__le32 current_depth;
+	__le32 i_xattr_nid;		/* nid to save xattr */
+	__le32 i_flags;			/* file attributes */
+	__le32 i_pino;			/* parent inode number */
+	__le32 i_namelen;		/* file name length */
+	__u8 i_name[F2FS_MAX_NAME_LEN];	/* file name for SPOR */
+
+	struct f2fs_extent i_ext;	/* caching a largest extent */
+
+	__le32 i_addr[ADDRS_PER_INODE];	/* Pointers to data blocks */
+
+	__le32 i_nid[5];		/* direct(2), indirect(2),
+						double_indirect(1) node id */
+} __packed;
+
+struct direct_node {
+	__le32 addr[ADDRS_PER_BLOCK];	/* array of data block address */
+} __packed;
+
+struct indirect_node {
+	__le32 nid[NIDS_PER_BLOCK];	/* array of data block address */
+} __packed;
+
+enum {
+	COLD_BIT_SHIFT = 0,
+	FSYNC_BIT_SHIFT,
+	DENT_BIT_SHIFT,
+	OFFSET_BIT_SHIFT
+};
+
+struct node_footer {
+	__le32 nid;		/* node id */
+	__le32 ino;		/* inode nunmber */
+	__le32 flag;		/* include cold/fsync/dentry marks and offset */
+	__le64 cp_ver;		/* checkpoint version */
+	__le32 next_blkaddr;	/* next node page block address */
+} __packed;
+
+struct f2fs_node {
+	union {
+		struct f2fs_inode i;
+		struct direct_node dn;
+		struct indirect_node in;
+	};
+	struct node_footer footer;
+} __packed;
+
+/*
+ * For NAT entries
+ */
+#define NAT_ENTRY_PER_BLOCK (PAGE_CACHE_SIZE / sizeof(struct f2fs_nat_entry))
+
+struct f2fs_nat_entry {
+	__u8 version;
+	__le32 ino;
+	__le32 block_addr;
+} __packed;
+
+struct f2fs_nat_block {
+	struct f2fs_nat_entry entries[NAT_ENTRY_PER_BLOCK];
+} __packed;
+
+/*
+ * For SIT entries
+ */
+#define SIT_VBLOCK_MAP_SIZE 64
+#define SIT_ENTRY_PER_BLOCK (PAGE_CACHE_SIZE / sizeof(struct f2fs_sit_entry))
+
+struct f2fs_sit_entry {
+	__le16 vblocks;
+	__u8 valid_map[SIT_VBLOCK_MAP_SIZE];
+	__le64 mtime;
+} __packed;
+
+struct f2fs_sit_block {
+	struct f2fs_sit_entry entries[SIT_ENTRY_PER_BLOCK];
+} __packed;
+
+/**
+ * For segment summary
+ *
+ * NOTE : For initializing fields, you must use set_summary
+ *
+ * - If data page, nid represents dnode's nid
+ * - If node page, nid represents the node page's nid.
+ *
+ * The ofs_in_node is used by only data page. It represents offset
+ * from node's page's beginning to get a data block address.
+ * ex) data_blkaddr = (block_t)(nodepage_start_address + ofs_in_node)
+ */
+struct f2fs_summary {
+	__le32 nid;
+	union {
+		__u8 reserved[3];
+		struct {
+			__u8 version;
+			__le16 ofs_in_node;
+		} __packed;
+	};
+} __packed;
+
+struct summary_footer {
+	unsigned char entry_type;
+	__u32 check_sum;
+} __packed;
+
+#define	SUMMARY_SIZE		(sizeof(struct f2fs_summary))
+#define	SUM_FOOTER_SIZE		(sizeof(struct summary_footer))
+#define ENTRIES_IN_SUM		512
+#define SUM_ENTRY_SIZE		(SUMMARY_SIZE * ENTRIES_IN_SUM)
+#define SUM_JOURNAL_SIZE	(PAGE_CACHE_SIZE - SUM_FOOTER_SIZE -\
+				SUM_ENTRY_SIZE)
+struct nat_journal_entry {
+	__le32 nid;
+	struct f2fs_nat_entry ne;
+} __packed;
+
+struct sit_journal_entry {
+	__le32 segno;
+	struct f2fs_sit_entry se;
+} __packed;
+
+#define NAT_JOURNAL_ENTRIES	((SUM_JOURNAL_SIZE - 2) /\
+				sizeof(struct nat_journal_entry))
+#define NAT_JOURNAL_RESERVED	((SUM_JOURNAL_SIZE - 2) %\
+				sizeof(struct nat_journal_entry))
+#define SIT_JOURNAL_ENTRIES	((SUM_JOURNAL_SIZE - 2) /\
+				sizeof(struct sit_journal_entry))
+#define SIT_JOURNAL_RESERVED	((SUM_JOURNAL_SIZE - 2) %\
+				sizeof(struct sit_journal_entry))
+enum {
+	NAT_JOURNAL = 0,
+	SIT_JOURNAL
+};
+
+struct nat_journal {
+	struct nat_journal_entry entries[NAT_JOURNAL_ENTRIES];
+	__u8 reserved[NAT_JOURNAL_RESERVED];
+} __packed;
+
+struct sit_journal {
+	struct sit_journal_entry entries[SIT_JOURNAL_ENTRIES];
+	__u8 reserved[SIT_JOURNAL_RESERVED];
+} __packed;
+
+struct f2fs_summary_block {
+	struct f2fs_summary entries[ENTRIES_IN_SUM];
+	union {
+		__le16 n_nats;
+		__le16 n_sits;
+	};
+	union {
+		struct nat_journal nat_j;
+		struct sit_journal sit_j;
+	};
+	struct summary_footer footer;
+} __packed;
+
+/*
+ * For directory operations
+ */
+#define F2FS_DOT_HASH		0
+#define F2FS_DDOT_HASH		F2FS_DOT_HASH
+#define F2FS_MAX_HASH		(~((0x3ULL) << 62))
+#define F2FS_HASH_COL_BIT	((0x1ULL) << 63)
+
+typedef __le32	f2fs_hash_t;
+
+#define F2FS_NAME_LEN		8
+#define NR_DENTRY_IN_BLOCK	214 /* the number of dentry in a block */
+#define MAX_DIR_HASH_DEPTH	63 /* MAX level for dir lookup */
+
+#define SIZE_OF_DIR_ENTRY	11	/* by byte */
+#define SIZE_OF_DENTRY_BITMAP	((NR_DENTRY_IN_BLOCK + BITS_PER_BYTE - 1) / \
+					BITS_PER_BYTE)
+#define SIZE_OF_RESERVED	(PAGE_SIZE - ((SIZE_OF_DIR_ENTRY + \
+				F2FS_NAME_LEN) * \
+				NR_DENTRY_IN_BLOCK + SIZE_OF_DENTRY_BITMAP))
+
+struct f2fs_dir_entry {
+	__le32 hash_code;	/* hash code of file name */
+	__le32 ino;		/* node number of inode */
+	__le16 name_len;	/* the size of file name
+				   length in unicode characters */
+	__u8 file_type;
+} __packed;
+
+struct f2fs_dentry_block {
+	__u8 dentry_bitmap[SIZE_OF_DENTRY_BITMAP];
+	__u8 reserved[SIZE_OF_RESERVED];
+	struct f2fs_dir_entry dentry[NR_DENTRY_IN_BLOCK];
+	__u8 filename[NR_DENTRY_IN_BLOCK][F2FS_NAME_LEN];
+} __packed;
+
+enum {
+	F2FS_FT_UNKNOWN,
+	F2FS_FT_REG_FILE,
+	F2FS_FT_DIR,
+	F2FS_FT_CHRDEV,
+	F2FS_FT_BLKDEV,
+	F2FS_FT_FIFO,
+	F2FS_FT_SOCK,
+	F2FS_FT_SYMLINK,
+	F2FS_FT_MAX
+};
+
+#endif  /* _LINUX_F2FS_FS_H */
-- 
1.7.9.5




---
Jaegeuk Kim
Samsung