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Message-id: <004001cdb74b$b05c94a0$1115bde0$%kim@samsung.com>
Date: Wed, 31 Oct 2012 18:39:57 +0900
From: Jaegeuk Kim <jaegeuk.kim@...sung.com>
To: linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
gregkh@...uxfoundation.org, viro@...iv.linux.org.uk, arnd@...db.de,
tytso@....edu, chur.lee@...sung.com, cm224.lee@...sung.com,
jooyoung.hwang@...sung.com
Subject: [PATCH 02/17] f2fs: add on-disk layout
This adds a header file describing the on-disk layout of f2fs.
Signed-off-by: Changman Lee <cm224.lee@...sung.com>
Signed-off-by: Chul Lee <chur.lee@...sung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@...sung.com>
---
include/linux/f2fs_fs.h | 410 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 410 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..1429ece
--- /dev/null
+++ b/include/linux/f2fs_fs.h
@@ -0,0 +1,410 @@
+/**
+ * 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_LOG_SECTOR_SIZE 9 /* 9 bits for 512 byte */
+#define F2FS_LOG_SECTORS_PER_BLOCK 3 /* 4KB: F2FS_BLKSIZE */
+#define F2FS_BLKSIZE 4096 /* support only 4KB block */
+#define F2FS_MAX_EXTENSION 64 /* # of extension entries */
+
+#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)
+
+/* This flag is used by node and meta inodes, and by recovery */
+#define GFP_F2FS_ZERO (GFP_NOFS | __GFP_ZERO)
+
+/*
+ * 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
+
+/*
+ * 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 # 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[512]; /* volume name */
+ __le32 extension_count; /* # of extensions below */
+ __u8 extension_list[F2FS_MAX_EXTENSION][8]; /* extension array */
+} __packed;
+
+/*
+ * For checkpoint
+ */
+#define CP_ERROR_FLAG 0x00000008
+#define CP_COMPACT_SUM_FLAG 0x00000004
+#define CP_ORPHAN_PRESENT_FLAG 0x00000002
+#define CP_UMOUNT_FLAG 0x00000001
+
+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
+
+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_addr; /* start block address of the extent */
+ __le32 len; /* lengh of the extent */
+} __packed;
+
+#define F2FS_MAX_NAME_LEN 256
+#define ADDRS_PER_INODE 923 /* 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_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_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 {
+ /* 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_CACHE_SIZE / sizeof(struct f2fs_nat_entry))
+
+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_CACHE_SIZE / sizeof(struct f2fs_sit_entry))
+
+/*
+ * 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 (sizeof(struct f2fs_summary))
+#define SUM_FOOTER_SIZE (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 */
+ __u32 check_sum; /* summary checksum */
+} __packed;
+
+#define SUM_JOURNAL_SIZE (PAGE_CACHE_SIZE - 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))
+/*
+ * 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;
+
+/* 4KB-sized summary block structure */
+struct f2fs_summary_block {
+ struct f2fs_summary entries[ENTRIES_IN_SUM];
+ union {
+ __le16 n_nats;
+ __le16 n_sits;
+ };
+ /* spare area is used by NAT or SIT journals */
+ 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;
+
+/* One directory entry slot covers 8bytes-long file name */
+#define F2FS_NAME_LEN 8
+
+/* the number of dentry in a block */
+#define NR_DENTRY_IN_BLOCK 214
+
+/* MAX level for dir lookup */
+#define MAX_DIR_HASH_DEPTH 63
+
+#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))
+
+/* One directory entry slot representing F2FS_NAME_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_NAME_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
+};
+
+#endif /* _LINUX_F2FS_FS_H */
--
1.7.9.5
---
Jaegeuk Kim
Samsung
--
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