Hi, On Tue, 2012-10-23 at 11:26 +0900, Jaegeuk Kim wrote: > This adds a header file describing the on-disk layout of f2fs. > > Signed-off-by: Changman Lee <cm224.lee@xxxxxxxxxxx> > Signed-off-by: Chul Lee <chur.lee@xxxxxxxxxxx> > Signed-off-by: Jaegeuk Kim <jaegeuk.kim@xxxxxxxxxxx> > --- > 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 */ Does f2fs superblock really haven't any offset from the volume begin? > +#define F2FS_BLKSIZE 4096 > +#define F2FS_MAX_EXTENSION 64 > + > +#define NULL_ADDR 0x0U > +#define NEW_ADDR -1U Does NULL_ADDR and NEW_ADDR declarations really need? Does kernel haven't any analogous? > + > +#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 I think that it makes sense to comment the reasons of such limitations in MAX_ACTIVE_LOGS, MAX_ACTIVE_NODE_LOGS, MAX_ACTIVE_DATA_LOGS. > + > +/* > + * 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) */ >From my point of view, __le32 is big data type for log2 (<value>). What do you think? > + __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 */ Usually, it is used 128-bits UUID for serial number. Why do you use __le32 as volume_serial_number? > + __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 It exists F2FS_MAX_NAME_LEN. I think that it makes sense to comment here purpose of F2FS_NAME_LEN declaration. > +#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 */ With the best regards, Vyacheslav Dubeyko. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
