include/linux/f2fs_fs.h - kernel/msm-4.19 - Gitiles

 /**
  * 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_OFFSET		1024	/* byte-size offset */
 #define F2FS_MIN_LOG_SECTOR_SIZE	9	/* 9 bits for 512 bytes */
 #define F2FS_MAX_LOG_SECTOR_SIZE	12	/* 12 bits for 4096 bytes */
 #define F2FS_LOG_SECTORS_PER_BLOCK	3	/* log number for sector/blk */
 #define F2FS_BLKSIZE			4096	/* support only 4KB block */
 #define F2FS_BLKSIZE_BITS		12	/* bits for F2FS_BLKSIZE */
 #define F2FS_MAX_EXTENSION		64	/* # of extension entries */
 #define F2FS_BLK_ALIGN(x)	(((x) + F2FS_BLKSIZE - 1) >> F2FS_BLKSIZE_BITS)

 #define NULL_ADDR		((block_t)0)	/* used as block_t addresses */
 #define NEW_ADDR		((block_t)-1)	/* used as block_t addresses */

 #define F2FS_BYTES_TO_BLK(bytes)	((bytes) >> F2FS_BLKSIZE_BITS)
 #define F2FS_BLK_TO_BYTES(blk)		((blk) << F2FS_BLKSIZE_BITS)

 /* 0, 1(node nid), 2(meta nid) are reserved node id */
 #define F2FS_RESERVED_NODE_NUM		3

 #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 F2FS_IO_SIZE(sbi)	(1 << (sbi)->write_io_size_bits) /* Blocks */
 #define F2FS_IO_SIZE_KB(sbi)	(1 << ((sbi)->write_io_size_bits + 2)) /* KB */
 #define F2FS_IO_SIZE_BYTES(sbi)	(1 << ((sbi)->write_io_size_bits + 12)) /* B */
 #define F2FS_IO_SIZE_BITS(sbi)	((sbi)->write_io_size_bits) /* power of 2 */
 #define F2FS_IO_SIZE_MASK(sbi)	(F2FS_IO_SIZE(sbi) - 1)

 /* This flag is used by node and meta inodes, and by recovery */
 #define GFP_F2FS_ZERO		(GFP_NOFS | __GFP_ZERO)
 #define GFP_F2FS_HIGH_ZERO	(GFP_NOFS | __GFP_ZERO | __GFP_HIGHMEM)

 /*
  * For further optimization on multi-head logs, on-disk layout supports maximum
  * 16 logs by default. The number, 16, is expected to cover all the cases
  * enoughly. The implementaion currently uses no more than 6 logs.
  * Half the logs are used for nodes, and the other half are used for data.
  */
 #define MAX_ACTIVE_LOGS	16
 #define MAX_ACTIVE_NODE_LOGS	8
 #define MAX_ACTIVE_DATA_LOGS	8

 #define VERSION_LEN	256
 #define MAX_VOLUME_NAME		512
 #define MAX_PATH_LEN		64
 #define MAX_DEVICES		8

 /*
  * For superblock
  */
 struct f2fs_device {
 	__u8 path[MAX_PATH_LEN];
 	__le32 total_segments;
 } __packed;

 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 # of sectors per block */
 	__le32 log_blocksize;		/* log2 block size in bytes */
 	__le32 log_blocks_per_seg;	/* log2 # of blocks per segment */
 	__le32 segs_per_sec;		/* # of segments per section */
 	__le32 secs_per_zone;		/* # of sections per zone */
 	__le32 checksum_offset;		/* checksum offset inside super block */
 	__le64 block_count;		/* total # of user blocks */
 	__le32 section_count;		/* total # of sections */
 	__le32 segment_count;		/* total # of segments */
 	__le32 segment_count_ckpt;	/* # of segments for checkpoint */
 	__le32 segment_count_sit;	/* # of segments for SIT */
 	__le32 segment_count_nat;	/* # of segments for NAT */
 	__le32 segment_count_ssa;	/* # of segments for SSA */
 	__le32 segment_count_main;	/* # of segments for main area */
 	__le32 segment0_blkaddr;	/* start block address of segment 0 */
 	__le32 cp_blkaddr;		/* start block address of checkpoint */
 	__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 inode number */
 	__le32 node_ino;		/* node inode number */
 	__le32 meta_ino;		/* meta inode number */
 	__u8 uuid[16];			/* 128-bit uuid for volume */
 	__le16 volume_name[MAX_VOLUME_NAME];	/* volume name */
 	__le32 extension_count;		/* # of extensions below */
 	__u8 extension_list[F2FS_MAX_EXTENSION][8];	/* extension array */
 	__le32 cp_payload;
 	__u8 version[VERSION_LEN];	/* the kernel version */
 	__u8 init_version[VERSION_LEN];	/* the initial kernel version */
 	__le32 feature;			/* defined features */
 	__u8 encryption_level;		/* versioning level for encryption */
 	__u8 encrypt_pw_salt[16];	/* Salt used for string2key algorithm */
 	struct f2fs_device devs[MAX_DEVICES];	/* device list */
 	__u8 reserved[327];		/* valid reserved region */
 } __packed;

 /*
  * For checkpoint
  */
 #define CP_TRIMMED_FLAG		0x00000100
 #define CP_NAT_BITS_FLAG	0x00000080
 #define CP_CRC_RECOVERY_FLAG	0x00000040
 #define CP_FASTBOOT_FLAG	0x00000020
 #define CP_FSCK_FLAG		0x00000010
 #define CP_ERROR_FLAG		0x00000008
 #define CP_COMPACT_SUM_FLAG	0x00000004
 #define CP_ORPHAN_PRESENT_FLAG	0x00000002
 #define CP_UMOUNT_FLAG		0x00000001

 #define F2FS_CP_PACKS		2	/* # of checkpoint packs */

 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];
 	/* 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;	/* total # of one cp pack */
 	__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 offset inside cp block */
 	__le64 elapsed_time;		/* mounted time */
 	/* 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

 #define GET_ORPHAN_BLOCKS(n)	(((n) + F2FS_ORPHANS_PER_BLOCK - 1) / \
 					F2FS_ORPHANS_PER_BLOCK)

 struct f2fs_orphan_block {
 	__le32 ino[F2FS_ORPHANS_PER_BLOCK];	/* inode numbers */
 	__le32 reserved;	/* 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;		/* start file offset of the extent */
 	__le32 blk;		/* start block address of the extent */
 	__le32 len;		/* lengh of the extent */
 } __packed;

 #define F2FS_NAME_LEN		255
 #define F2FS_INLINE_XATTR_ADDRS	50	/* 200 bytes for inline xattrs */
 #define DEF_ADDRS_PER_INODE	923	/* Address Pointers in an Inode */
 #define DEF_NIDS_PER_INODE	5	/* Node IDs in an Inode */
 #define ADDRS_PER_INODE(inode)	addrs_per_inode(inode)
 #define ADDRS_PER_BLOCK		1018	/* Address Pointers in a Direct Block */
 #define NIDS_PER_BLOCK		1018	/* Node IDs in an Indirect Block */

 #define ADDRS_PER_PAGE(page, inode)	\
 	(IS_INODE(page) ? ADDRS_PER_INODE(inode) : ADDRS_PER_BLOCK)

 #define	NODE_DIR1_BLOCK		(DEF_ADDRS_PER_INODE + 1)
 #define	NODE_DIR2_BLOCK		(DEF_ADDRS_PER_INODE + 2)
 #define	NODE_IND1_BLOCK		(DEF_ADDRS_PER_INODE + 3)
 #define	NODE_IND2_BLOCK		(DEF_ADDRS_PER_INODE + 4)
 #define	NODE_DIND_BLOCK		(DEF_ADDRS_PER_INODE + 5)

 #define F2FS_INLINE_XATTR	0x01	/* file inline xattr flag */
 #define F2FS_INLINE_DATA	0x02	/* file inline data flag */
 #define F2FS_INLINE_DENTRY	0x04	/* file inline dentry flag */
 #define F2FS_DATA_EXIST		0x08	/* file inline data exist flag */
 #define F2FS_INLINE_DOTS	0x10	/* file having implicit dot dentries */

 #define MAX_INLINE_DATA		(sizeof(__le32) * (DEF_ADDRS_PER_INODE - \
 						F2FS_INLINE_XATTR_ADDRS - 1))

 struct f2fs_inode {
 	__le16 i_mode;			/* file mode */
 	__u8 i_advise;			/* file hints */
 	__u8 i_inline;			/* file inline flags */
 	__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_atime;			/* access time */
 	__le64 i_ctime;			/* change time */
 	__le64 i_mtime;			/* modification time */
 	__le32 i_atime_nsec;		/* access time in nano scale */
 	__le32 i_ctime_nsec;		/* change time in nano scale */
 	__le32 i_mtime_nsec;		/* modification time in nano scale */
 	__le32 i_generation;		/* file version (for NFS) */
 	__le32 i_current_depth;		/* only for directory 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_NAME_LEN];	/* file name for SPOR */
 	__u8 i_dir_level;		/* dentry_level for large dir */

 	struct f2fs_extent i_ext;	/* caching a largest extent */

 	__le32 i_addr[DEF_ADDRS_PER_INODE];	/* Pointers to data blocks */

 	__le32 i_nid[DEF_NIDS_PER_INODE];	/* 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
 };

 #define OFFSET_BIT_MASK		(0x07)	/* (0x01 << OFFSET_BIT_SHIFT) - 1 */

 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 {
 	/* can be one of three types: inode, direct, and indirect types */
 	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_SIZE / sizeof(struct f2fs_nat_entry))
 #define NAT_ENTRY_BITMAP_SIZE	((NAT_ENTRY_PER_BLOCK + 7) / 8)

 struct f2fs_nat_entry {
 	__u8 version;		/* latest version of cached nat entry */
 	__le32 ino;		/* inode number */
 	__le32 block_addr;	/* block address */
 } __packed;

 struct f2fs_nat_block {
 	struct f2fs_nat_entry entries[NAT_ENTRY_PER_BLOCK];
 } __packed;

 /*
  * For SIT entries
  *
  * Each segment is 2MB in size by default so that a bitmap for validity of
  * there-in blocks should occupy 64 bytes, 512 bits.
  * Not allow to change this.
  */
 #define SIT_VBLOCK_MAP_SIZE 64
 #define SIT_ENTRY_PER_BLOCK (PAGE_SIZE / sizeof(struct f2fs_sit_entry))

 /*
  * F2FS uses 4 bytes to represent block address. As a result, supported size of
  * disk is 16 TB and it equals to 16 * 1024 * 1024 / 2 segments.
  */
 #define F2FS_MAX_SEGMENT       ((16 * 1024 * 1024) / 2)

 /*
  * Note that f2fs_sit_entry->vblocks has the following bit-field information.
  * [15:10] : allocation type such as CURSEG_XXXX_TYPE
  * [9:0] : valid block count
  */
 #define SIT_VBLOCKS_SHIFT	10
 #define SIT_VBLOCKS_MASK	((1 << SIT_VBLOCKS_SHIFT) - 1)
 #define GET_SIT_VBLOCKS(raw_sit)				\
 	(le16_to_cpu((raw_sit)->vblocks) & SIT_VBLOCKS_MASK)
 #define GET_SIT_TYPE(raw_sit)					\
 	((le16_to_cpu((raw_sit)->vblocks) & ~SIT_VBLOCKS_MASK)	\
 	 >> SIT_VBLOCKS_SHIFT)

 struct f2fs_sit_entry {
 	__le16 vblocks;				/* reference above */
 	__u8 valid_map[SIT_VBLOCK_MAP_SIZE];	/* bitmap for valid blocks */
 	__le64 mtime;				/* segment age for cleaning */
 } __packed;

 struct f2fs_sit_block {
 	struct f2fs_sit_entry entries[SIT_ENTRY_PER_BLOCK];
 } __packed;

 /*
  * For segment summary
  *
  * One summary block contains exactly 512 summary entries, which represents
  * exactly 2MB segment by default. Not allow to change the basic units.
  *
  * 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)
  */
 #define ENTRIES_IN_SUM		512
 #define	SUMMARY_SIZE		(7)	/* sizeof(struct summary) */
 #define	SUM_FOOTER_SIZE		(5)	/* sizeof(struct summary_footer) */
 #define SUM_ENTRY_SIZE		(SUMMARY_SIZE * ENTRIES_IN_SUM)

 /* a summary entry for a 4KB-sized block in a segment */
 struct f2fs_summary {
 	__le32 nid;		/* parent node id */
 	union {
 		__u8 reserved[3];
 		struct {
 			__u8 version;		/* node version number */
 			__le16 ofs_in_node;	/* block index in parent node */
 		} __packed;
 	};
 } __packed;

 /* summary block type, node or data, is stored to the summary_footer */
 #define SUM_TYPE_NODE		(1)
 #define SUM_TYPE_DATA		(0)

 struct summary_footer {
 	unsigned char entry_type;	/* SUM_TYPE_XXX */
 	__le32 check_sum;		/* summary checksum */
 } __packed;

 #define SUM_JOURNAL_SIZE	(F2FS_BLKSIZE - SUM_FOOTER_SIZE -\
 				SUM_ENTRY_SIZE)
 #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))

 /* Reserved area should make size of f2fs_extra_info equals to
  * that of nat_journal and sit_journal.
  */
 #define EXTRA_INFO_RESERVED	(SUM_JOURNAL_SIZE - 2 - 8)

 /*
  * frequently updated NAT/SIT entries can be stored in the spare area in
  * summary blocks
  */
 enum {
 	NAT_JOURNAL = 0,
 	SIT_JOURNAL
 };

 struct nat_journal_entry {
 	__le32 nid;
 	struct f2fs_nat_entry ne;
 } __packed;

 struct nat_journal {
 	struct nat_journal_entry entries[NAT_JOURNAL_ENTRIES];
 	__u8 reserved[NAT_JOURNAL_RESERVED];
 } __packed;

 struct sit_journal_entry {
 	__le32 segno;
 	struct f2fs_sit_entry se;
 } __packed;

 struct sit_journal {
 	struct sit_journal_entry entries[SIT_JOURNAL_ENTRIES];
 	__u8 reserved[SIT_JOURNAL_RESERVED];
 } __packed;

 struct f2fs_extra_info {
 	__le64 kbytes_written;
 	__u8 reserved[EXTRA_INFO_RESERVED];
 } __packed;

 struct f2fs_journal {
 	union {
 		__le16 n_nats;
 		__le16 n_sits;
 	};
 	/* spare area is used by NAT or SIT journals or extra info */
 	union {
 		struct nat_journal nat_j;
 		struct sit_journal sit_j;
 		struct f2fs_extra_info info;
 	};
 } __packed;

 /* 4KB-sized summary block structure */
 struct f2fs_summary_block {
 	struct f2fs_summary entries[ENTRIES_IN_SUM];
 	struct f2fs_journal journal;
 	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;

 /* One directory entry slot covers 8bytes-long file name */
 #define F2FS_SLOT_LEN		8
 #define F2FS_SLOT_LEN_BITS	3

 #define GET_DENTRY_SLOTS(x) (((x) + F2FS_SLOT_LEN - 1) >> F2FS_SLOT_LEN_BITS)

 /* MAX level for dir lookup */
 #define MAX_DIR_HASH_DEPTH	63

 /* MAX buckets in one level of dir */
 #define MAX_DIR_BUCKETS		(1 << ((MAX_DIR_HASH_DEPTH / 2) - 1))

 /*
  * space utilization of regular dentry and inline dentry
  *		regular dentry			inline dentry
  * bitmap	1 * 27 = 27			1 * 23 = 23
  * reserved	1 * 3 = 3			1 * 7 = 7
  * dentry	11 * 214 = 2354			11 * 182 = 2002
  * filename	8 * 214 = 1712			8 * 182 = 1456
  * total	4096				3488
  *
  * Note: there are more reserved space in inline dentry than in regular
  * dentry, when converting inline dentry we should handle this carefully.
  */
 #define NR_DENTRY_IN_BLOCK	214	/* the number of dentry in a block */
 #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_SLOT_LEN) * \
 				NR_DENTRY_IN_BLOCK + SIZE_OF_DENTRY_BITMAP))

 /* One directory entry slot representing F2FS_SLOT_LEN-sized file name */
 struct f2fs_dir_entry {
 	__le32 hash_code;	/* hash code of file name */
 	__le32 ino;		/* inode number */
 	__le16 name_len;	/* lengh of file name */
 	__u8 file_type;		/* file type */
 } __packed;

 /* 4KB-sized directory entry block */
 struct f2fs_dentry_block {
 	/* validity bitmap for directory entries in each 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_SLOT_LEN];
 } __packed;

 /* for inline dir */
 #define NR_INLINE_DENTRY	(MAX_INLINE_DATA * BITS_PER_BYTE / \
 				((SIZE_OF_DIR_ENTRY + F2FS_SLOT_LEN) * \
 				BITS_PER_BYTE + 1))
 #define INLINE_DENTRY_BITMAP_SIZE	((NR_INLINE_DENTRY + \
 					BITS_PER_BYTE - 1) / BITS_PER_BYTE)
 #define INLINE_RESERVED_SIZE	(MAX_INLINE_DATA - \
 				((SIZE_OF_DIR_ENTRY + F2FS_SLOT_LEN) * \
 				NR_INLINE_DENTRY + INLINE_DENTRY_BITMAP_SIZE))

 /* inline directory entry structure */
 struct f2fs_inline_dentry {
 	__u8 dentry_bitmap[INLINE_DENTRY_BITMAP_SIZE];
 	__u8 reserved[INLINE_RESERVED_SIZE];
 	struct f2fs_dir_entry dentry[NR_INLINE_DENTRY];
 	__u8 filename[NR_INLINE_DENTRY][F2FS_SLOT_LEN];
 } __packed;

 /* file types used in inode_info->flags */
 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
 };

 #define S_SHIFT 12

 #endif  /* _LINUX_F2FS_FS_H */
	/**
	* 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_OFFSET 1024 /* byte-size offset */
	#define F2FS_MIN_LOG_SECTOR_SIZE 9 /* 9 bits for 512 bytes */
	#define F2FS_MAX_LOG_SECTOR_SIZE 12 /* 12 bits for 4096 bytes */
	#define F2FS_LOG_SECTORS_PER_BLOCK 3 /* log number for sector/blk */
	#define F2FS_BLKSIZE 4096 /* support only 4KB block */
	#define F2FS_BLKSIZE_BITS 12 /* bits for F2FS_BLKSIZE */
	#define F2FS_MAX_EXTENSION 64 /* # of extension entries */
	#define F2FS_BLK_ALIGN(x) (((x) + F2FS_BLKSIZE - 1) >> F2FS_BLKSIZE_BITS)

	#define NULL_ADDR ((block_t)0) /* used as block_t addresses */
	#define NEW_ADDR ((block_t)-1) /* used as block_t addresses */

	#define F2FS_BYTES_TO_BLK(bytes) ((bytes) >> F2FS_BLKSIZE_BITS)
	#define F2FS_BLK_TO_BYTES(blk) ((blk) << F2FS_BLKSIZE_BITS)

	/* 0, 1(node nid), 2(meta nid) are reserved node id */
	#define F2FS_RESERVED_NODE_NUM 3

	#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 F2FS_IO_SIZE(sbi) (1 << (sbi)->write_io_size_bits) /* Blocks */
	#define F2FS_IO_SIZE_KB(sbi) (1 << ((sbi)->write_io_size_bits + 2)) /* KB */
	#define F2FS_IO_SIZE_BYTES(sbi) (1 << ((sbi)->write_io_size_bits + 12)) /* B */
	#define F2FS_IO_SIZE_BITS(sbi) ((sbi)->write_io_size_bits) /* power of 2 */
	#define F2FS_IO_SIZE_MASK(sbi) (F2FS_IO_SIZE(sbi) - 1)

	/* This flag is used by node and meta inodes, and by recovery */
	#define GFP_F2FS_ZERO (GFP_NOFS \| __GFP_ZERO)
	#define GFP_F2FS_HIGH_ZERO (GFP_NOFS \| __GFP_ZERO \| __GFP_HIGHMEM)

	/*
	* For further optimization on multi-head logs, on-disk layout supports maximum
	* 16 logs by default. The number, 16, is expected to cover all the cases
	* enoughly. The implementaion currently uses no more than 6 logs.
	* Half the logs are used for nodes, and the other half are used for data.
	*/
	#define MAX_ACTIVE_LOGS 16
	#define MAX_ACTIVE_NODE_LOGS 8
	#define MAX_ACTIVE_DATA_LOGS 8

	#define VERSION_LEN 256
	#define MAX_VOLUME_NAME 512
	#define MAX_PATH_LEN 64
	#define MAX_DEVICES 8

	/*
	* For superblock
	*/
	struct f2fs_device {
	__u8 path[MAX_PATH_LEN];
	__le32 total_segments;
	} __packed;

	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 # of sectors per block */
	__le32 log_blocksize; /* log2 block size in bytes */
	__le32 log_blocks_per_seg; /* log2 # of blocks per segment */
	__le32 segs_per_sec; /* # of segments per section */
	__le32 secs_per_zone; /* # of sections per zone */
	__le32 checksum_offset; /* checksum offset inside super block */
	__le64 block_count; /* total # of user blocks */
	__le32 section_count; /* total # of sections */
	__le32 segment_count; /* total # of segments */
	__le32 segment_count_ckpt; /* # of segments for checkpoint */
	__le32 segment_count_sit; /* # of segments for SIT */
	__le32 segment_count_nat; /* # of segments for NAT */
	__le32 segment_count_ssa; /* # of segments for SSA */
	__le32 segment_count_main; /* # of segments for main area */
	__le32 segment0_blkaddr; /* start block address of segment 0 */
	__le32 cp_blkaddr; /* start block address of checkpoint */
	__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 inode number */
	__le32 node_ino; /* node inode number */
	__le32 meta_ino; /* meta inode number */
	__u8 uuid[16]; /* 128-bit uuid for volume */
	__le16 volume_name[MAX_VOLUME_NAME]; /* volume name */
	__le32 extension_count; /* # of extensions below */
	__u8 extension_list[F2FS_MAX_EXTENSION][8]; /* extension array */
	__le32 cp_payload;
	__u8 version[VERSION_LEN]; /* the kernel version */
	__u8 init_version[VERSION_LEN]; /* the initial kernel version */
	__le32 feature; /* defined features */
	__u8 encryption_level; /* versioning level for encryption */
	__u8 encrypt_pw_salt[16]; /* Salt used for string2key algorithm */
	struct f2fs_device devs[MAX_DEVICES]; /* device list */
	__u8 reserved[327]; /* valid reserved region */
	} __packed;

	/*
	* For checkpoint
	*/
	#define CP_TRIMMED_FLAG 0x00000100
	#define CP_NAT_BITS_FLAG 0x00000080
	#define CP_CRC_RECOVERY_FLAG 0x00000040
	#define CP_FASTBOOT_FLAG 0x00000020
	#define CP_FSCK_FLAG 0x00000010
	#define CP_ERROR_FLAG 0x00000008
	#define CP_COMPACT_SUM_FLAG 0x00000004
	#define CP_ORPHAN_PRESENT_FLAG 0x00000002
	#define CP_UMOUNT_FLAG 0x00000001

	#define F2FS_CP_PACKS 2 /* # of checkpoint packs */

	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];
	/* 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; /* total # of one cp pack */
	__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 offset inside cp block */
	__le64 elapsed_time; /* mounted time */
	/* 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

	#define GET_ORPHAN_BLOCKS(n) (((n) + F2FS_ORPHANS_PER_BLOCK - 1) / \
	F2FS_ORPHANS_PER_BLOCK)

	struct f2fs_orphan_block {
	__le32 ino[F2FS_ORPHANS_PER_BLOCK]; /* inode numbers */
	__le32 reserved; /* 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; /* start file offset of the extent */
	__le32 blk; /* start block address of the extent */
	__le32 len; /* lengh of the extent */
	} __packed;

	#define F2FS_NAME_LEN 255
	#define F2FS_INLINE_XATTR_ADDRS 50 /* 200 bytes for inline xattrs */
	#define DEF_ADDRS_PER_INODE 923 /* Address Pointers in an Inode */
	#define DEF_NIDS_PER_INODE 5 /* Node IDs in an Inode */
	#define ADDRS_PER_INODE(inode) addrs_per_inode(inode)
	#define ADDRS_PER_BLOCK 1018 /* Address Pointers in a Direct Block */
	#define NIDS_PER_BLOCK 1018 /* Node IDs in an Indirect Block */

	#define ADDRS_PER_PAGE(page, inode) \
	(IS_INODE(page) ? ADDRS_PER_INODE(inode) : ADDRS_PER_BLOCK)

	#define NODE_DIR1_BLOCK (DEF_ADDRS_PER_INODE + 1)
	#define NODE_DIR2_BLOCK (DEF_ADDRS_PER_INODE + 2)
	#define NODE_IND1_BLOCK (DEF_ADDRS_PER_INODE + 3)
	#define NODE_IND2_BLOCK (DEF_ADDRS_PER_INODE + 4)
	#define NODE_DIND_BLOCK (DEF_ADDRS_PER_INODE + 5)

	#define F2FS_INLINE_XATTR 0x01 /* file inline xattr flag */
	#define F2FS_INLINE_DATA 0x02 /* file inline data flag */
	#define F2FS_INLINE_DENTRY 0x04 /* file inline dentry flag */
	#define F2FS_DATA_EXIST 0x08 /* file inline data exist flag */
	#define F2FS_INLINE_DOTS 0x10 /* file having implicit dot dentries */

	#define MAX_INLINE_DATA (sizeof(__le32) * (DEF_ADDRS_PER_INODE - \
	F2FS_INLINE_XATTR_ADDRS - 1))

	struct f2fs_inode {
	__le16 i_mode; /* file mode */
	__u8 i_advise; /* file hints */
	__u8 i_inline; /* file inline flags */
	__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_atime; /* access time */
	__le64 i_ctime; /* change time */
	__le64 i_mtime; /* modification time */
	__le32 i_atime_nsec; /* access time in nano scale */
	__le32 i_ctime_nsec; /* change time in nano scale */
	__le32 i_mtime_nsec; /* modification time in nano scale */
	__le32 i_generation; /* file version (for NFS) */
	__le32 i_current_depth; /* only for directory 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_NAME_LEN]; /* file name for SPOR */
	__u8 i_dir_level; /* dentry_level for large dir */

	struct f2fs_extent i_ext; /* caching a largest extent */

	__le32 i_addr[DEF_ADDRS_PER_INODE]; /* Pointers to data blocks */

	__le32 i_nid[DEF_NIDS_PER_INODE]; /* 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
	};

	#define OFFSET_BIT_MASK (0x07) /* (0x01 << OFFSET_BIT_SHIFT) - 1 */

	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 {
	/* can be one of three types: inode, direct, and indirect types */
	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_SIZE / sizeof(struct f2fs_nat_entry))
	#define NAT_ENTRY_BITMAP_SIZE ((NAT_ENTRY_PER_BLOCK + 7) / 8)

	struct f2fs_nat_entry {
	__u8 version; /* latest version of cached nat entry */
	__le32 ino; /* inode number */
	__le32 block_addr; /* block address */
	} __packed;

	struct f2fs_nat_block {
	struct f2fs_nat_entry entries[NAT_ENTRY_PER_BLOCK];
	} __packed;

	/*
	* For SIT entries
	*
	* Each segment is 2MB in size by default so that a bitmap for validity of
	* there-in blocks should occupy 64 bytes, 512 bits.
	* Not allow to change this.
	*/
	#define SIT_VBLOCK_MAP_SIZE 64
	#define SIT_ENTRY_PER_BLOCK (PAGE_SIZE / sizeof(struct f2fs_sit_entry))

	/*
	* F2FS uses 4 bytes to represent block address. As a result, supported size of
	* disk is 16 TB and it equals to 16 * 1024 * 1024 / 2 segments.
	*/
	#define F2FS_MAX_SEGMENT ((16 * 1024 * 1024) / 2)

	/*
	* Note that f2fs_sit_entry->vblocks has the following bit-field information.
	* [15:10] : allocation type such as CURSEG_XXXX_TYPE
	* [9:0] : valid block count
	*/
	#define SIT_VBLOCKS_SHIFT 10
	#define SIT_VBLOCKS_MASK ((1 << SIT_VBLOCKS_SHIFT) - 1)
	#define GET_SIT_VBLOCKS(raw_sit) \
	(le16_to_cpu((raw_sit)->vblocks) & SIT_VBLOCKS_MASK)
	#define GET_SIT_TYPE(raw_sit) \
	((le16_to_cpu((raw_sit)->vblocks) & ~SIT_VBLOCKS_MASK) \
	>> SIT_VBLOCKS_SHIFT)

	struct f2fs_sit_entry {
	__le16 vblocks; /* reference above */
	__u8 valid_map[SIT_VBLOCK_MAP_SIZE]; /* bitmap for valid blocks */
	__le64 mtime; /* segment age for cleaning */
	} __packed;

	struct f2fs_sit_block {
	struct f2fs_sit_entry entries[SIT_ENTRY_PER_BLOCK];
	} __packed;

	/*
	* For segment summary
	*
	* One summary block contains exactly 512 summary entries, which represents
	* exactly 2MB segment by default. Not allow to change the basic units.
	*
	* 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)
	*/
	#define ENTRIES_IN_SUM 512
	#define SUMMARY_SIZE (7) /* sizeof(struct summary) */
	#define SUM_FOOTER_SIZE (5) /* sizeof(struct summary_footer) */
	#define SUM_ENTRY_SIZE (SUMMARY_SIZE * ENTRIES_IN_SUM)

	/* a summary entry for a 4KB-sized block in a segment */
	struct f2fs_summary {
	__le32 nid; /* parent node id */
	union {
	__u8 reserved[3];
	struct {
	__u8 version; /* node version number */
	__le16 ofs_in_node; /* block index in parent node */
	} __packed;
	};
	} __packed;

	/* summary block type, node or data, is stored to the summary_footer */
	#define SUM_TYPE_NODE (1)
	#define SUM_TYPE_DATA (0)

	struct summary_footer {
	unsigned char entry_type; /* SUM_TYPE_XXX */
	__le32 check_sum; /* summary checksum */
	} __packed;

	#define SUM_JOURNAL_SIZE (F2FS_BLKSIZE - SUM_FOOTER_SIZE -\
	SUM_ENTRY_SIZE)
	#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))

	/* Reserved area should make size of f2fs_extra_info equals to
	* that of nat_journal and sit_journal.
	*/
	#define EXTRA_INFO_RESERVED (SUM_JOURNAL_SIZE - 2 - 8)

	/*
	* frequently updated NAT/SIT entries can be stored in the spare area in
	* summary blocks
	*/
	enum {
	NAT_JOURNAL = 0,
	SIT_JOURNAL
	};

	struct nat_journal_entry {
	__le32 nid;
	struct f2fs_nat_entry ne;
	} __packed;

	struct nat_journal {
	struct nat_journal_entry entries[NAT_JOURNAL_ENTRIES];
	__u8 reserved[NAT_JOURNAL_RESERVED];
	} __packed;

	struct sit_journal_entry {
	__le32 segno;
	struct f2fs_sit_entry se;
	} __packed;

	struct sit_journal {
	struct sit_journal_entry entries[SIT_JOURNAL_ENTRIES];
	__u8 reserved[SIT_JOURNAL_RESERVED];
	} __packed;

	struct f2fs_extra_info {
	__le64 kbytes_written;
	__u8 reserved[EXTRA_INFO_RESERVED];
	} __packed;

	struct f2fs_journal {
	union {
	__le16 n_nats;
	__le16 n_sits;
	};
	/* spare area is used by NAT or SIT journals or extra info */
	union {
	struct nat_journal nat_j;
	struct sit_journal sit_j;
	struct f2fs_extra_info info;
	};
	} __packed;

	/* 4KB-sized summary block structure */
	struct f2fs_summary_block {
	struct f2fs_summary entries[ENTRIES_IN_SUM];
	struct f2fs_journal journal;
	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;

	/* One directory entry slot covers 8bytes-long file name */
	#define F2FS_SLOT_LEN 8
	#define F2FS_SLOT_LEN_BITS 3

	#define GET_DENTRY_SLOTS(x) (((x) + F2FS_SLOT_LEN - 1) >> F2FS_SLOT_LEN_BITS)

	/* MAX level for dir lookup */
	#define MAX_DIR_HASH_DEPTH 63

	/* MAX buckets in one level of dir */
	#define MAX_DIR_BUCKETS (1 << ((MAX_DIR_HASH_DEPTH / 2) - 1))

	/*
	* space utilization of regular dentry and inline dentry
	* regular dentry inline dentry
	* bitmap 1 * 27 = 27 1 * 23 = 23
	* reserved 1 * 3 = 3 1 * 7 = 7
	* dentry 11 * 214 = 2354 11 * 182 = 2002
	* filename 8 * 214 = 1712 8 * 182 = 1456
	* total 4096 3488
	*
	* Note: there are more reserved space in inline dentry than in regular
	* dentry, when converting inline dentry we should handle this carefully.
	*/
	#define NR_DENTRY_IN_BLOCK 214 /* the number of dentry in a block */
	#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_SLOT_LEN) * \
	NR_DENTRY_IN_BLOCK + SIZE_OF_DENTRY_BITMAP))

	/* One directory entry slot representing F2FS_SLOT_LEN-sized file name */
	struct f2fs_dir_entry {
	__le32 hash_code; /* hash code of file name */
	__le32 ino; /* inode number */
	__le16 name_len; /* lengh of file name */
	__u8 file_type; /* file type */
	} __packed;

	/* 4KB-sized directory entry block */
	struct f2fs_dentry_block {
	/* validity bitmap for directory entries in each 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_SLOT_LEN];
	} __packed;

	/* for inline dir */
	#define NR_INLINE_DENTRY (MAX_INLINE_DATA * BITS_PER_BYTE / \
	((SIZE_OF_DIR_ENTRY + F2FS_SLOT_LEN) * \
	BITS_PER_BYTE + 1))
	#define INLINE_DENTRY_BITMAP_SIZE ((NR_INLINE_DENTRY + \
	BITS_PER_BYTE - 1) / BITS_PER_BYTE)
	#define INLINE_RESERVED_SIZE (MAX_INLINE_DATA - \
	((SIZE_OF_DIR_ENTRY + F2FS_SLOT_LEN) * \
	NR_INLINE_DENTRY + INLINE_DENTRY_BITMAP_SIZE))

	/* inline directory entry structure */
	struct f2fs_inline_dentry {
	__u8 dentry_bitmap[INLINE_DENTRY_BITMAP_SIZE];
	__u8 reserved[INLINE_RESERVED_SIZE];
	struct f2fs_dir_entry dentry[NR_INLINE_DENTRY];
	__u8 filename[NR_INLINE_DENTRY][F2FS_SLOT_LEN];
	} __packed;

	/* file types used in inode_info->flags */
	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
	};

	#define S_SHIFT 12

	#endif /* _LINUX_F2FS_FS_H */