include/linux/f2fs_fs.h

   1 // SPDX-License-Identifier: GPL-2.0
   2 /**
   3  * include/linux/f2fs_fs.h
   4  *
   5  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
   6  *             http://www.samsung.com/
   7  */
   8 #ifndef _LINUX_F2FS_FS_H
   9 #define _LINUX_F2FS_FS_H
  10
  11 #include <linux/pagemap.h>
  12 #include <linux/types.h>
  13
  14 #define F2FS_SUPER_OFFSET               1024    /* byte-size offset */
  15 #define F2FS_MIN_LOG_SECTOR_SIZE        9       /* 9 bits for 512 bytes */
  16 #define F2FS_MAX_LOG_SECTOR_SIZE        12      /* 12 bits for 4096 bytes */
  17 #define F2FS_LOG_SECTORS_PER_BLOCK      3       /* log number for sector/blk */
  18 #define F2FS_BLKSIZE                    4096    /* support only 4KB block */
  19 #define F2FS_BLKSIZE_BITS               12      /* bits for F2FS_BLKSIZE */
  20 #define F2FS_MAX_EXTENSION              64      /* # of extension entries */
  21 #define F2FS_EXTENSION_LEN              8       /* max size of extension */
  22 #define F2FS_BLK_ALIGN(x)       (((x) + F2FS_BLKSIZE - 1) >> F2FS_BLKSIZE_BITS)
  23
  24 #define NULL_ADDR               ((block_t)0)    /* used as block_t addresses */
  25 #define NEW_ADDR                ((block_t)-1)   /* used as block_t addresses */
  26 #define COMPRESS_ADDR           ((block_t)-2)   /* used as compressed data flag */
  27
  28 #define F2FS_BYTES_TO_BLK(bytes)        ((bytes) >> F2FS_BLKSIZE_BITS)
  29 #define F2FS_BLK_TO_BYTES(blk)          ((blk) << F2FS_BLKSIZE_BITS)
  30
  31 /* 0, 1(node nid), 2(meta nid) are reserved node id */
  32 #define F2FS_RESERVED_NODE_NUM          3
  33
  34 #define F2FS_ROOT_INO(sbi)      ((sbi)->root_ino_num)
  35 #define F2FS_NODE_INO(sbi)      ((sbi)->node_ino_num)
  36 #define F2FS_META_INO(sbi)      ((sbi)->meta_ino_num)
  37 #define F2FS_COMPRESS_INO(sbi)  (NM_I(sbi)->max_nid)
  38
  39 #define F2FS_MAX_QUOTAS         3
  40
  41 #define F2FS_ENC_UTF8_12_1      1
  42
  43 #define F2FS_IO_SIZE(sbi)       (1 << F2FS_OPTION(sbi).write_io_size_bits) /* Blocks */
  44 #define F2FS_IO_SIZE_KB(sbi)    (1 << (F2FS_OPTION(sbi).write_io_size_bits + 2)) /* KB */
  45 #define F2FS_IO_SIZE_BYTES(sbi) (1 << (F2FS_OPTION(sbi).write_io_size_bits + 12)) /* B */
  46 #define F2FS_IO_SIZE_BITS(sbi)  (F2FS_OPTION(sbi).write_io_size_bits) /* power of 2 */
  47 #define F2FS_IO_SIZE_MASK(sbi)  (F2FS_IO_SIZE(sbi) - 1)
  48 #define F2FS_IO_ALIGNED(sbi)    (F2FS_IO_SIZE(sbi) > 1)
  49
  50 /* This flag is used by node and meta inodes, and by recovery */
  51 #define GFP_F2FS_ZERO           (GFP_NOFS | __GFP_ZERO)
  52
  53 /*
  54  * For further optimization on multi-head logs, on-disk layout supports maximum
  55  * 16 logs by default. The number, 16, is expected to cover all the cases
  56  * enoughly. The implementaion currently uses no more than 6 logs.
  57  * Half the logs are used for nodes, and the other half are used for data.
  58  */
  59 #define MAX_ACTIVE_LOGS 16
  60 #define MAX_ACTIVE_NODE_LOGS    8
  61 #define MAX_ACTIVE_DATA_LOGS    8
  62
  63 #define VERSION_LEN     256
  64 #define MAX_VOLUME_NAME         512
  65 #define MAX_PATH_LEN            64
  66 #define MAX_DEVICES             8
  67
  68 /*
  69  * For superblock
  70  */
  71 struct f2fs_device {
  72         __u8 path[MAX_PATH_LEN];
  73         __le32 total_segments;
  74 } __packed;
  75
  76 struct f2fs_super_block {
  77         __le32 magic;                   /* Magic Number */
  78         __le16 major_ver;               /* Major Version */
  79         __le16 minor_ver;               /* Minor Version */
  80         __le32 log_sectorsize;          /* log2 sector size in bytes */
  81         __le32 log_sectors_per_block;   /* log2 # of sectors per block */
  82         __le32 log_blocksize;           /* log2 block size in bytes */
  83         __le32 log_blocks_per_seg;      /* log2 # of blocks per segment */
  84         __le32 segs_per_sec;            /* # of segments per section */
  85         __le32 secs_per_zone;           /* # of sections per zone */
  86         __le32 checksum_offset;         /* checksum offset inside super block */
  87         __le64 block_count;             /* total # of user blocks */
  88         __le32 section_count;           /* total # of sections */
  89         __le32 segment_count;           /* total # of segments */
  90         __le32 segment_count_ckpt;      /* # of segments for checkpoint */
  91         __le32 segment_count_sit;       /* # of segments for SIT */
  92         __le32 segment_count_nat;       /* # of segments for NAT */
  93         __le32 segment_count_ssa;       /* # of segments for SSA */
  94         __le32 segment_count_main;      /* # of segments for main area */
  95         __le32 segment0_blkaddr;        /* start block address of segment 0 */
  96         __le32 cp_blkaddr;              /* start block address of checkpoint */
  97         __le32 sit_blkaddr;             /* start block address of SIT */
  98         __le32 nat_blkaddr;             /* start block address of NAT */
  99         __le32 ssa_blkaddr;             /* start block address of SSA */
 100         __le32 main_blkaddr;            /* start block address of main area */
 101         __le32 root_ino;                /* root inode number */
 102         __le32 node_ino;                /* node inode number */
 103         __le32 meta_ino;                /* meta inode number */
 104         __u8 uuid[16];                  /* 128-bit uuid for volume */
 105         __le16 volume_name[MAX_VOLUME_NAME];    /* volume name */
 106         __le32 extension_count;         /* # of extensions below */
 107         __u8 extension_list[F2FS_MAX_EXTENSION][F2FS_EXTENSION_LEN];/* extension array */
 108         __le32 cp_payload;
 109         __u8 version[VERSION_LEN];      /* the kernel version */
 110         __u8 init_version[VERSION_LEN]; /* the initial kernel version */
 111         __le32 feature;                 /* defined features */
 112         __u8 encryption_level;          /* versioning level for encryption */
 113         __u8 encrypt_pw_salt[16];       /* Salt used for string2key algorithm */
 114         struct f2fs_device devs[MAX_DEVICES];   /* device list */
 115         __le32 qf_ino[F2FS_MAX_QUOTAS]; /* quota inode numbers */
 116         __u8 hot_ext_count;             /* # of hot file extension */
 117         __le16  s_encoding;             /* Filename charset encoding */
 118         __le16  s_encoding_flags;       /* Filename charset encoding flags */
 119         __u8 reserved[306];             /* valid reserved region */
 120         __le32 crc;                     /* checksum of superblock */
 121 } __packed;
 122
 123 /*
 124  * For checkpoint
 125  */
 126 #define CP_RESIZEFS_FLAG                0x00004000
 127 #define CP_DISABLED_QUICK_FLAG          0x00002000
 128 #define CP_DISABLED_FLAG                0x00001000
 129 #define CP_QUOTA_NEED_FSCK_FLAG         0x00000800
 130 #define CP_LARGE_NAT_BITMAP_FLAG        0x00000400
 131 #define CP_NOCRC_RECOVERY_FLAG  0x00000200
 132 #define CP_TRIMMED_FLAG         0x00000100
 133 #define CP_NAT_BITS_FLAG        0x00000080
 134 #define CP_CRC_RECOVERY_FLAG    0x00000040
 135 #define CP_FASTBOOT_FLAG        0x00000020
 136 #define CP_FSCK_FLAG            0x00000010
 137 #define CP_ERROR_FLAG           0x00000008
 138 #define CP_COMPACT_SUM_FLAG     0x00000004
 139 #define CP_ORPHAN_PRESENT_FLAG  0x00000002
 140 #define CP_UMOUNT_FLAG          0x00000001
 141
 142 #define F2FS_CP_PACKS           2       /* # of checkpoint packs */
 143
 144 struct f2fs_checkpoint {
 145         __le64 checkpoint_ver;          /* checkpoint block version number */
 146         __le64 user_block_count;        /* # of user blocks */
 147         __le64 valid_block_count;       /* # of valid blocks in main area */
 148         __le32 rsvd_segment_count;      /* # of reserved segments for gc */
 149         __le32 overprov_segment_count;  /* # of overprovision segments */
 150         __le32 free_segment_count;      /* # of free segments in main area */
 151
 152         /* information of current node segments */
 153         __le32 cur_node_segno[MAX_ACTIVE_NODE_LOGS];
 154         __le16 cur_node_blkoff[MAX_ACTIVE_NODE_LOGS];
 155         /* information of current data segments */
 156         __le32 cur_data_segno[MAX_ACTIVE_DATA_LOGS];
 157         __le16 cur_data_blkoff[MAX_ACTIVE_DATA_LOGS];
 158         __le32 ckpt_flags;              /* Flags : umount and journal_present */
 159         __le32 cp_pack_total_block_count;       /* total # of one cp pack */
 160         __le32 cp_pack_start_sum;       /* start block number of data summary */
 161         __le32 valid_node_count;        /* Total number of valid nodes */
 162         __le32 valid_inode_count;       /* Total number of valid inodes */
 163         __le32 next_free_nid;           /* Next free node number */
 164         __le32 sit_ver_bitmap_bytesize; /* Default value 64 */
 165         __le32 nat_ver_bitmap_bytesize; /* Default value 256 */
 166         __le32 checksum_offset;         /* checksum offset inside cp block */
 167         __le64 elapsed_time;            /* mounted time */
 168         /* allocation type of current segment */
 169         unsigned char alloc_type[MAX_ACTIVE_LOGS];
 170
 171         /* SIT and NAT version bitmap */
 172         unsigned char sit_nat_version_bitmap[];
 173 } __packed;
 174
 175 #define CP_CHKSUM_OFFSET        4092    /* default chksum offset in checkpoint */
 176 #define CP_MIN_CHKSUM_OFFSET                                            \
 177         (offsetof(struct f2fs_checkpoint, sit_nat_version_bitmap))
 178
 179 /*
 180  * For orphan inode management
 181  */
 182 #define F2FS_ORPHANS_PER_BLOCK  1020
 183
 184 #define GET_ORPHAN_BLOCKS(n)    (((n) + F2FS_ORPHANS_PER_BLOCK - 1) / \
 185                                         F2FS_ORPHANS_PER_BLOCK)
 186
 187 struct f2fs_orphan_block {
 188         __le32 ino[F2FS_ORPHANS_PER_BLOCK];     /* inode numbers */
 189         __le32 reserved;        /* reserved */
 190         __le16 blk_addr;        /* block index in current CP */
 191         __le16 blk_count;       /* Number of orphan inode blocks in CP */
 192         __le32 entry_count;     /* Total number of orphan nodes in current CP */
 193         __le32 check_sum;       /* CRC32 for orphan inode block */
 194 } __packed;
 195
 196 /*
 197  * For NODE structure
 198  */
 199 struct f2fs_extent {
 200         __le32 fofs;            /* start file offset of the extent */
 201         __le32 blk;             /* start block address of the extent */
 202         __le32 len;             /* length of the extent */
 203 } __packed;
 204
 205 #define F2FS_NAME_LEN           255
 206 /* 200 bytes for inline xattrs by default */
 207 #define DEFAULT_INLINE_XATTR_ADDRS      50
 208 #define DEF_ADDRS_PER_INODE     923     /* Address Pointers in an Inode */
 209 #define CUR_ADDRS_PER_INODE(inode)      (DEF_ADDRS_PER_INODE - \
 210                                         get_extra_isize(inode))
 211 #define DEF_NIDS_PER_INODE      5       /* Node IDs in an Inode */
 212 #define ADDRS_PER_INODE(inode)  addrs_per_inode(inode)
 213 #define DEF_ADDRS_PER_BLOCK     1018    /* Address Pointers in a Direct Block */
 214 #define ADDRS_PER_BLOCK(inode)  addrs_per_block(inode)
 215 #define NIDS_PER_BLOCK          1018    /* Node IDs in an Indirect Block */
 216
 217 #define ADDRS_PER_PAGE(page, inode)     \
 218         (IS_INODE(page) ? ADDRS_PER_INODE(inode) : ADDRS_PER_BLOCK(inode))
 219
 220 #define NODE_DIR1_BLOCK         (DEF_ADDRS_PER_INODE + 1)
 221 #define NODE_DIR2_BLOCK         (DEF_ADDRS_PER_INODE + 2)
 222 #define NODE_IND1_BLOCK         (DEF_ADDRS_PER_INODE + 3)
 223 #define NODE_IND2_BLOCK         (DEF_ADDRS_PER_INODE + 4)
 224 #define NODE_DIND_BLOCK         (DEF_ADDRS_PER_INODE + 5)
 225
 226 #define F2FS_INLINE_XATTR       0x01    /* file inline xattr flag */
 227 #define F2FS_INLINE_DATA        0x02    /* file inline data flag */
 228 #define F2FS_INLINE_DENTRY      0x04    /* file inline dentry flag */
 229 #define F2FS_DATA_EXIST         0x08    /* file inline data exist flag */
 230 #define F2FS_INLINE_DOTS        0x10    /* file having implicit dot dentries */
 231 #define F2FS_EXTRA_ATTR         0x20    /* file having extra attribute */
 232 #define F2FS_PIN_FILE           0x40    /* file should not be gced */
 233 #define F2FS_COMPRESS_RELEASED  0x80    /* file released compressed blocks */
 234
 235 struct f2fs_inode {
 236         __le16 i_mode;                  /* file mode */
 237         __u8 i_advise;                  /* file hints */
 238         __u8 i_inline;                  /* file inline flags */
 239         __le32 i_uid;                   /* user ID */
 240         __le32 i_gid;                   /* group ID */
 241         __le32 i_links;                 /* links count */
 242         __le64 i_size;                  /* file size in bytes */
 243         __le64 i_blocks;                /* file size in blocks */
 244         __le64 i_atime;                 /* access time */
 245         __le64 i_ctime;                 /* change time */
 246         __le64 i_mtime;                 /* modification time */
 247         __le32 i_atime_nsec;            /* access time in nano scale */
 248         __le32 i_ctime_nsec;            /* change time in nano scale */
 249         __le32 i_mtime_nsec;            /* modification time in nano scale */
 250         __le32 i_generation;            /* file version (for NFS) */
 251         union {
 252                 __le32 i_current_depth; /* only for directory depth */
 253                 __le16 i_gc_failures;   /*
 254                                          * # of gc failures on pinned file.
 255                                          * only for regular files.
 256                                          */
 257         };
 258         __le32 i_xattr_nid;             /* nid to save xattr */
 259         __le32 i_flags;                 /* file attributes */
 260         __le32 i_pino;                  /* parent inode number */
 261         __le32 i_namelen;               /* file name length */
 262         __u8 i_name[F2FS_NAME_LEN];     /* file name for SPOR */
 263         __u8 i_dir_level;               /* dentry_level for large dir */
 264
 265         struct f2fs_extent i_ext;       /* caching a largest extent */
 266
 267         union {
 268                 struct {
 269                         __le16 i_extra_isize;   /* extra inode attribute size */
 270                         __le16 i_inline_xattr_size;     /* inline xattr size, unit: 4 bytes */
 271                         __le32 i_projid;        /* project id */
 272                         __le32 i_inode_checksum;/* inode meta checksum */
 273                         __le64 i_crtime;        /* creation time */
 274                         __le32 i_crtime_nsec;   /* creation time in nano scale */
 275                         __le64 i_compr_blocks;  /* # of compressed blocks */
 276                         __u8 i_compress_algorithm;      /* compress algorithm */
 277                         __u8 i_log_cluster_size;        /* log of cluster size */
 278                         __le16 i_compress_flag;         /* compress flag */
 279                                                 /* 0 bit: chksum flag
 280                                                  * [10,15] bits: compress level
 281                                                  */
 282                         __le32 i_extra_end[0];  /* for attribute size calculation */
 283                 } __packed;
 284                 __le32 i_addr[DEF_ADDRS_PER_INODE];     /* Pointers to data blocks */
 285         };
 286         __le32 i_nid[DEF_NIDS_PER_INODE];       /* direct(2), indirect(2),
 287                                                 double_indirect(1) node id */
 288 } __packed;
 289
 290 struct direct_node {
 291         __le32 addr[DEF_ADDRS_PER_BLOCK];       /* array of data block address */
 292 } __packed;
 293
 294 struct indirect_node {
 295         __le32 nid[NIDS_PER_BLOCK];     /* array of data block address */
 296 } __packed;
 297
 298 enum {
 299         COLD_BIT_SHIFT = 0,
 300         FSYNC_BIT_SHIFT,
 301         DENT_BIT_SHIFT,
 302         OFFSET_BIT_SHIFT
 303 };
 304
 305 #define OFFSET_BIT_MASK         (0x07)  /* (0x01 << OFFSET_BIT_SHIFT) - 1 */
 306
 307 struct node_footer {
 308         __le32 nid;             /* node id */
 309         __le32 ino;             /* inode number */
 310         __le32 flag;            /* include cold/fsync/dentry marks and offset */
 311         __le64 cp_ver;          /* checkpoint version */
 312         __le32 next_blkaddr;    /* next node page block address */
 313 } __packed;
 314
 315 struct f2fs_node {
 316         /* can be one of three types: inode, direct, and indirect types */
 317         union {
 318                 struct f2fs_inode i;
 319                 struct direct_node dn;
 320                 struct indirect_node in;
 321         };
 322         struct node_footer footer;
 323 } __packed;
 324
 325 /*
 326  * For NAT entries
 327  */
 328 #define NAT_ENTRY_PER_BLOCK (PAGE_SIZE / sizeof(struct f2fs_nat_entry))
 329
 330 struct f2fs_nat_entry {
 331         __u8 version;           /* latest version of cached nat entry */
 332         __le32 ino;             /* inode number */
 333         __le32 block_addr;      /* block address */
 334 } __packed;
 335
 336 struct f2fs_nat_block {
 337         struct f2fs_nat_entry entries[NAT_ENTRY_PER_BLOCK];
 338 } __packed;
 339
 340 /*
 341  * For SIT entries
 342  *
 343  * Each segment is 2MB in size by default so that a bitmap for validity of
 344  * there-in blocks should occupy 64 bytes, 512 bits.
 345  * Not allow to change this.
 346  */
 347 #define SIT_VBLOCK_MAP_SIZE 64
 348 #define SIT_ENTRY_PER_BLOCK (PAGE_SIZE / sizeof(struct f2fs_sit_entry))
 349
 350 /*
 351  * F2FS uses 4 bytes to represent block address. As a result, supported size of
 352  * disk is 16 TB and it equals to 16 * 1024 * 1024 / 2 segments.
 353  */
 354 #define F2FS_MAX_SEGMENT       ((16 * 1024 * 1024) / 2)
 355
 356 /*
 357  * Note that f2fs_sit_entry->vblocks has the following bit-field information.
 358  * [15:10] : allocation type such as CURSEG_XXXX_TYPE
 359  * [9:0] : valid block count
 360  */
 361 #define SIT_VBLOCKS_SHIFT       10
 362 #define SIT_VBLOCKS_MASK        ((1 << SIT_VBLOCKS_SHIFT) - 1)
 363 #define GET_SIT_VBLOCKS(raw_sit)                                \
 364         (le16_to_cpu((raw_sit)->vblocks) & SIT_VBLOCKS_MASK)
 365 #define GET_SIT_TYPE(raw_sit)                                   \
 366         ((le16_to_cpu((raw_sit)->vblocks) & ~SIT_VBLOCKS_MASK)  \
 367          >> SIT_VBLOCKS_SHIFT)
 368
 369 struct f2fs_sit_entry {
 370         __le16 vblocks;                         /* reference above */
 371         __u8 valid_map[SIT_VBLOCK_MAP_SIZE];    /* bitmap for valid blocks */
 372         __le64 mtime;                           /* segment age for cleaning */
 373 } __packed;
 374
 375 struct f2fs_sit_block {
 376         struct f2fs_sit_entry entries[SIT_ENTRY_PER_BLOCK];
 377 } __packed;
 378
 379 /*
 380  * For segment summary
 381  *
 382  * One summary block contains exactly 512 summary entries, which represents
 383  * exactly 2MB segment by default. Not allow to change the basic units.
 384  *
 385  * NOTE: For initializing fields, you must use set_summary
 386  *
 387  * - If data page, nid represents dnode's nid
 388  * - If node page, nid represents the node page's nid.
 389  *
 390  * The ofs_in_node is used by only data page. It represents offset
 391  * from node's page's beginning to get a data block address.
 392  * ex) data_blkaddr = (block_t)(nodepage_start_address + ofs_in_node)
 393  */
 394 #define ENTRIES_IN_SUM          512
 395 #define SUMMARY_SIZE            (7)     /* sizeof(struct summary) */
 396 #define SUM_FOOTER_SIZE         (5)     /* sizeof(struct summary_footer) */
 397 #define SUM_ENTRY_SIZE          (SUMMARY_SIZE * ENTRIES_IN_SUM)
 398
 399 /* a summary entry for a 4KB-sized block in a segment */
 400 struct f2fs_summary {
 401         __le32 nid;             /* parent node id */
 402         union {
 403                 __u8 reserved[3];
 404                 struct {
 405                         __u8 version;           /* node version number */
 406                         __le16 ofs_in_node;     /* block index in parent node */
 407                 } __packed;
 408         };
 409 } __packed;
 410
 411 /* summary block type, node or data, is stored to the summary_footer */
 412 #define SUM_TYPE_NODE           (1)
 413 #define SUM_TYPE_DATA           (0)
 414
 415 struct summary_footer {
 416         unsigned char entry_type;       /* SUM_TYPE_XXX */
 417         __le32 check_sum;               /* summary checksum */
 418 } __packed;
 419
 420 #define SUM_JOURNAL_SIZE        (F2FS_BLKSIZE - SUM_FOOTER_SIZE -\
 421                                 SUM_ENTRY_SIZE)
 422 #define NAT_JOURNAL_ENTRIES     ((SUM_JOURNAL_SIZE - 2) /\
 423                                 sizeof(struct nat_journal_entry))
 424 #define NAT_JOURNAL_RESERVED    ((SUM_JOURNAL_SIZE - 2) %\
 425                                 sizeof(struct nat_journal_entry))
 426 #define SIT_JOURNAL_ENTRIES     ((SUM_JOURNAL_SIZE - 2) /\
 427                                 sizeof(struct sit_journal_entry))
 428 #define SIT_JOURNAL_RESERVED    ((SUM_JOURNAL_SIZE - 2) %\
 429                                 sizeof(struct sit_journal_entry))
 430
 431 /* Reserved area should make size of f2fs_extra_info equals to
 432  * that of nat_journal and sit_journal.
 433  */
 434 #define EXTRA_INFO_RESERVED     (SUM_JOURNAL_SIZE - 2 - 8)
 435
 436 /*
 437  * frequently updated NAT/SIT entries can be stored in the spare area in
 438  * summary blocks
 439  */
 440 enum {
 441         NAT_JOURNAL = 0,
 442         SIT_JOURNAL
 443 };
 444
 445 struct nat_journal_entry {
 446         __le32 nid;
 447         struct f2fs_nat_entry ne;
 448 } __packed;
 449
 450 struct nat_journal {
 451         struct nat_journal_entry entries[NAT_JOURNAL_ENTRIES];
 452         __u8 reserved[NAT_JOURNAL_RESERVED];
 453 } __packed;
 454
 455 struct sit_journal_entry {
 456         __le32 segno;
 457         struct f2fs_sit_entry se;
 458 } __packed;
 459
 460 struct sit_journal {
 461         struct sit_journal_entry entries[SIT_JOURNAL_ENTRIES];
 462         __u8 reserved[SIT_JOURNAL_RESERVED];
 463 } __packed;
 464
 465 struct f2fs_extra_info {
 466         __le64 kbytes_written;
 467         __u8 reserved[EXTRA_INFO_RESERVED];
 468 } __packed;
 469
 470 struct f2fs_journal {
 471         union {
 472                 __le16 n_nats;
 473                 __le16 n_sits;
 474         };
 475         /* spare area is used by NAT or SIT journals or extra info */
 476         union {
 477                 struct nat_journal nat_j;
 478                 struct sit_journal sit_j;
 479                 struct f2fs_extra_info info;
 480         };
 481 } __packed;
 482
 483 /* 4KB-sized summary block structure */
 484 struct f2fs_summary_block {
 485         struct f2fs_summary entries[ENTRIES_IN_SUM];
 486         struct f2fs_journal journal;
 487         struct summary_footer footer;
 488 } __packed;
 489
 490 /*
 491  * For directory operations
 492  */
 493 #define F2FS_DOT_HASH           0
 494 #define F2FS_DDOT_HASH          F2FS_DOT_HASH
 495 #define F2FS_MAX_HASH           (~((0x3ULL) << 62))
 496 #define F2FS_HASH_COL_BIT       ((0x1ULL) << 63)
 497
 498 typedef __le32  f2fs_hash_t;
 499
 500 /* One directory entry slot covers 8bytes-long file name */
 501 #define F2FS_SLOT_LEN           8
 502 #define F2FS_SLOT_LEN_BITS      3
 503
 504 #define GET_DENTRY_SLOTS(x) (((x) + F2FS_SLOT_LEN - 1) >> F2FS_SLOT_LEN_BITS)
 505
 506 /* MAX level for dir lookup */
 507 #define MAX_DIR_HASH_DEPTH      63
 508
 509 /* MAX buckets in one level of dir */
 510 #define MAX_DIR_BUCKETS         (1 << ((MAX_DIR_HASH_DEPTH / 2) - 1))
 511
 512 /*
 513  * space utilization of regular dentry and inline dentry (w/o extra reservation)
 514  *              regular dentry          inline dentry (def)     inline dentry (min)
 515  * bitmap       1 * 27 = 27             1 * 23 = 23             1 * 1 = 1
 516  * reserved     1 * 3 = 3               1 * 7 = 7               1 * 1 = 1
 517  * dentry       11 * 214 = 2354         11 * 182 = 2002         11 * 2 = 22
 518  * filename     8 * 214 = 1712          8 * 182 = 1456          8 * 2 = 16
 519  * total        4096                    3488                    40
 520  *
 521  * Note: there are more reserved space in inline dentry than in regular
 522  * dentry, when converting inline dentry we should handle this carefully.
 523  */
 524 #define NR_DENTRY_IN_BLOCK      214     /* the number of dentry in a block */
 525 #define SIZE_OF_DIR_ENTRY       11      /* by byte */
 526 #define SIZE_OF_DENTRY_BITMAP   ((NR_DENTRY_IN_BLOCK + BITS_PER_BYTE - 1) / \
 527                                         BITS_PER_BYTE)
 528 #define SIZE_OF_RESERVED        (PAGE_SIZE - ((SIZE_OF_DIR_ENTRY + \
 529                                 F2FS_SLOT_LEN) * \
 530                                 NR_DENTRY_IN_BLOCK + SIZE_OF_DENTRY_BITMAP))
 531 #define MIN_INLINE_DENTRY_SIZE          40      /* just include '.' and '..' entries */
 532
 533 /* One directory entry slot representing F2FS_SLOT_LEN-sized file name */
 534 struct f2fs_dir_entry {
 535         __le32 hash_code;       /* hash code of file name */
 536         __le32 ino;             /* inode number */
 537         __le16 name_len;        /* length of file name */
 538         __u8 file_type;         /* file type */
 539 } __packed;
 540
 541 /* 4KB-sized directory entry block */
 542 struct f2fs_dentry_block {
 543         /* validity bitmap for directory entries in each block */
 544         __u8 dentry_bitmap[SIZE_OF_DENTRY_BITMAP];
 545         __u8 reserved[SIZE_OF_RESERVED];
 546         struct f2fs_dir_entry dentry[NR_DENTRY_IN_BLOCK];
 547         __u8 filename[NR_DENTRY_IN_BLOCK][F2FS_SLOT_LEN];
 548 } __packed;
 549
 550 /* file types used in inode_info->flags */
 551 enum {
 552         F2FS_FT_UNKNOWN,
 553         F2FS_FT_REG_FILE,
 554         F2FS_FT_DIR,
 555         F2FS_FT_CHRDEV,
 556         F2FS_FT_BLKDEV,
 557         F2FS_FT_FIFO,
 558         F2FS_FT_SOCK,
 559         F2FS_FT_SYMLINK,
 560         F2FS_FT_MAX
 561 };
 562
 563 #define S_SHIFT 12
 564
 565 #define F2FS_DEF_PROJID         0       /* default project ID */
 566
 567 #endif  /* _LINUX_F2FS_FS_H */