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