linux/include/linux/f2fs_fs.h
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   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 */
  66struct f2fs_device {
  67        __u8 path[MAX_PATH_LEN];
  68        __le32 total_segments;
  69} __packed;
  70
  71struct 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_QUICK_FLAG          0x00002000
 120#define CP_DISABLED_FLAG                0x00001000
 121#define CP_QUOTA_NEED_FSCK_FLAG         0x00000800
 122#define CP_LARGE_NAT_BITMAP_FLAG        0x00000400
 123#define CP_NOCRC_RECOVERY_FLAG  0x00000200
 124#define CP_TRIMMED_FLAG         0x00000100
 125#define CP_NAT_BITS_FLAG        0x00000080
 126#define CP_CRC_RECOVERY_FLAG    0x00000040
 127#define CP_FASTBOOT_FLAG        0x00000020
 128#define CP_FSCK_FLAG            0x00000010
 129#define CP_ERROR_FLAG           0x00000008
 130#define CP_COMPACT_SUM_FLAG     0x00000004
 131#define CP_ORPHAN_PRESENT_FLAG  0x00000002
 132#define CP_UMOUNT_FLAG          0x00000001
 133
 134#define F2FS_CP_PACKS           2       /* # of checkpoint packs */
 135
 136struct f2fs_checkpoint {
 137        __le64 checkpoint_ver;          /* checkpoint block version number */
 138        __le64 user_block_count;        /* # of user blocks */
 139        __le64 valid_block_count;       /* # of valid blocks in main area */
 140        __le32 rsvd_segment_count;      /* # of reserved segments for gc */
 141        __le32 overprov_segment_count;  /* # of overprovision segments */
 142        __le32 free_segment_count;      /* # of free segments in main area */
 143
 144        /* information of current node segments */
 145        __le32 cur_node_segno[MAX_ACTIVE_NODE_LOGS];
 146        __le16 cur_node_blkoff[MAX_ACTIVE_NODE_LOGS];
 147        /* information of current data segments */
 148        __le32 cur_data_segno[MAX_ACTIVE_DATA_LOGS];
 149        __le16 cur_data_blkoff[MAX_ACTIVE_DATA_LOGS];
 150        __le32 ckpt_flags;              /* Flags : umount and journal_present */
 151        __le32 cp_pack_total_block_count;       /* total # of one cp pack */
 152        __le32 cp_pack_start_sum;       /* start block number of data summary */
 153        __le32 valid_node_count;        /* Total number of valid nodes */
 154        __le32 valid_inode_count;       /* Total number of valid inodes */
 155        __le32 next_free_nid;           /* Next free node number */
 156        __le32 sit_ver_bitmap_bytesize; /* Default value 64 */
 157        __le32 nat_ver_bitmap_bytesize; /* Default value 256 */
 158        __le32 checksum_offset;         /* checksum offset inside cp block */
 159        __le64 elapsed_time;            /* mounted time */
 160        /* allocation type of current segment */
 161        unsigned char alloc_type[MAX_ACTIVE_LOGS];
 162
 163        /* SIT and NAT version bitmap */
 164        unsigned char sit_nat_version_bitmap[1];
 165} __packed;
 166
 167#define CP_CHKSUM_OFFSET        4092    /* default chksum offset in checkpoint */
 168#define CP_MIN_CHKSUM_OFFSET                                            \
 169        (offsetof(struct f2fs_checkpoint, sit_nat_version_bitmap))
 170
 171/*
 172 * For orphan inode management
 173 */
 174#define F2FS_ORPHANS_PER_BLOCK  1020
 175
 176#define GET_ORPHAN_BLOCKS(n)    (((n) + F2FS_ORPHANS_PER_BLOCK - 1) / \
 177                                        F2FS_ORPHANS_PER_BLOCK)
 178
 179struct f2fs_orphan_block {
 180        __le32 ino[F2FS_ORPHANS_PER_BLOCK];     /* inode numbers */
 181        __le32 reserved;        /* reserved */
 182        __le16 blk_addr;        /* block index in current CP */
 183        __le16 blk_count;       /* Number of orphan inode blocks in CP */
 184        __le32 entry_count;     /* Total number of orphan nodes in current CP */
 185        __le32 check_sum;       /* CRC32 for orphan inode block */
 186} __packed;
 187
 188/*
 189 * For NODE structure
 190 */
 191struct f2fs_extent {
 192        __le32 fofs;            /* start file offset of the extent */
 193        __le32 blk;             /* start block address of the extent */
 194        __le32 len;             /* length of the extent */
 195} __packed;
 196
 197#define F2FS_NAME_LEN           255
 198/* 200 bytes for inline xattrs by default */
 199#define DEFAULT_INLINE_XATTR_ADDRS      50
 200#define DEF_ADDRS_PER_INODE     923     /* Address Pointers in an Inode */
 201#define CUR_ADDRS_PER_INODE(inode)      (DEF_ADDRS_PER_INODE - \
 202                                        get_extra_isize(inode))
 203#define DEF_NIDS_PER_INODE      5       /* Node IDs in an Inode */
 204#define ADDRS_PER_INODE(inode)  addrs_per_inode(inode)
 205#define DEF_ADDRS_PER_BLOCK     1018    /* Address Pointers in a Direct Block */
 206#define ADDRS_PER_BLOCK(inode)  addrs_per_block(inode)
 207#define NIDS_PER_BLOCK          1018    /* Node IDs in an Indirect Block */
 208
 209#define ADDRS_PER_PAGE(page, inode)     \
 210        (IS_INODE(page) ? ADDRS_PER_INODE(inode) : ADDRS_PER_BLOCK(inode))
 211
 212#define NODE_DIR1_BLOCK         (DEF_ADDRS_PER_INODE + 1)
 213#define NODE_DIR2_BLOCK         (DEF_ADDRS_PER_INODE + 2)
 214#define NODE_IND1_BLOCK         (DEF_ADDRS_PER_INODE + 3)
 215#define NODE_IND2_BLOCK         (DEF_ADDRS_PER_INODE + 4)
 216#define NODE_DIND_BLOCK         (DEF_ADDRS_PER_INODE + 5)
 217
 218#define F2FS_INLINE_XATTR       0x01    /* file inline xattr flag */
 219#define F2FS_INLINE_DATA        0x02    /* file inline data flag */
 220#define F2FS_INLINE_DENTRY      0x04    /* file inline dentry flag */
 221#define F2FS_DATA_EXIST         0x08    /* file inline data exist flag */
 222#define F2FS_INLINE_DOTS        0x10    /* file having implicit dot dentries */
 223#define F2FS_EXTRA_ATTR         0x20    /* file having extra attribute */
 224#define F2FS_PIN_FILE           0x40    /* file should not be gced */
 225
 226struct f2fs_inode {
 227        __le16 i_mode;                  /* file mode */
 228        __u8 i_advise;                  /* file hints */
 229        __u8 i_inline;                  /* file inline flags */
 230        __le32 i_uid;                   /* user ID */
 231        __le32 i_gid;                   /* group ID */
 232        __le32 i_links;                 /* links count */
 233        __le64 i_size;                  /* file size in bytes */
 234        __le64 i_blocks;                /* file size in blocks */
 235        __le64 i_atime;                 /* access time */
 236        __le64 i_ctime;                 /* change time */
 237        __le64 i_mtime;                 /* modification time */
 238        __le32 i_atime_nsec;            /* access time in nano scale */
 239        __le32 i_ctime_nsec;            /* change time in nano scale */
 240        __le32 i_mtime_nsec;            /* modification time in nano scale */
 241        __le32 i_generation;            /* file version (for NFS) */
 242        union {
 243                __le32 i_current_depth; /* only for directory depth */
 244                __le16 i_gc_failures;   /*
 245                                         * # of gc failures on pinned file.
 246                                         * only for regular files.
 247                                         */
 248        };
 249        __le32 i_xattr_nid;             /* nid to save xattr */
 250        __le32 i_flags;                 /* file attributes */
 251        __le32 i_pino;                  /* parent inode number */
 252        __le32 i_namelen;               /* file name length */
 253        __u8 i_name[F2FS_NAME_LEN];     /* file name for SPOR */
 254        __u8 i_dir_level;               /* dentry_level for large dir */
 255
 256        struct f2fs_extent i_ext;       /* caching a largest extent */
 257
 258        union {
 259                struct {
 260                        __le16 i_extra_isize;   /* extra inode attribute size */
 261                        __le16 i_inline_xattr_size;     /* inline xattr size, unit: 4 bytes */
 262                        __le32 i_projid;        /* project id */
 263                        __le32 i_inode_checksum;/* inode meta checksum */
 264                        __le64 i_crtime;        /* creation time */
 265                        __le32 i_crtime_nsec;   /* creation time in nano scale */
 266                        __le32 i_extra_end[0];  /* for attribute size calculation */
 267                } __packed;
 268                __le32 i_addr[DEF_ADDRS_PER_INODE];     /* Pointers to data blocks */
 269        };
 270        __le32 i_nid[DEF_NIDS_PER_INODE];       /* direct(2), indirect(2),
 271                                                double_indirect(1) node id */
 272} __packed;
 273
 274struct direct_node {
 275        __le32 addr[DEF_ADDRS_PER_BLOCK];       /* array of data block address */
 276} __packed;
 277
 278struct indirect_node {
 279        __le32 nid[NIDS_PER_BLOCK];     /* array of data block address */
 280} __packed;
 281
 282enum {
 283        COLD_BIT_SHIFT = 0,
 284        FSYNC_BIT_SHIFT,
 285        DENT_BIT_SHIFT,
 286        OFFSET_BIT_SHIFT
 287};
 288
 289#define OFFSET_BIT_MASK         (0x07)  /* (0x01 << OFFSET_BIT_SHIFT) - 1 */
 290
 291struct node_footer {
 292        __le32 nid;             /* node id */
 293        __le32 ino;             /* inode number */
 294        __le32 flag;            /* include cold/fsync/dentry marks and offset */
 295        __le64 cp_ver;          /* checkpoint version */
 296        __le32 next_blkaddr;    /* next node page block address */
 297} __packed;
 298
 299struct f2fs_node {
 300        /* can be one of three types: inode, direct, and indirect types */
 301        union {
 302                struct f2fs_inode i;
 303                struct direct_node dn;
 304                struct indirect_node in;
 305        };
 306        struct node_footer footer;
 307} __packed;
 308
 309/*
 310 * For NAT entries
 311 */
 312#define NAT_ENTRY_PER_BLOCK (PAGE_SIZE / sizeof(struct f2fs_nat_entry))
 313
 314struct f2fs_nat_entry {
 315        __u8 version;           /* latest version of cached nat entry */
 316        __le32 ino;             /* inode number */
 317        __le32 block_addr;      /* block address */
 318} __packed;
 319
 320struct f2fs_nat_block {
 321        struct f2fs_nat_entry entries[NAT_ENTRY_PER_BLOCK];
 322} __packed;
 323
 324/*
 325 * For SIT entries
 326 *
 327 * Each segment is 2MB in size by default so that a bitmap for validity of
 328 * there-in blocks should occupy 64 bytes, 512 bits.
 329 * Not allow to change this.
 330 */
 331#define SIT_VBLOCK_MAP_SIZE 64
 332#define SIT_ENTRY_PER_BLOCK (PAGE_SIZE / sizeof(struct f2fs_sit_entry))
 333
 334/*
 335 * F2FS uses 4 bytes to represent block address. As a result, supported size of
 336 * disk is 16 TB and it equals to 16 * 1024 * 1024 / 2 segments.
 337 */
 338#define F2FS_MAX_SEGMENT       ((16 * 1024 * 1024) / 2)
 339
 340/*
 341 * Note that f2fs_sit_entry->vblocks has the following bit-field information.
 342 * [15:10] : allocation type such as CURSEG_XXXX_TYPE
 343 * [9:0] : valid block count
 344 */
 345#define SIT_VBLOCKS_SHIFT       10
 346#define SIT_VBLOCKS_MASK        ((1 << SIT_VBLOCKS_SHIFT) - 1)
 347#define GET_SIT_VBLOCKS(raw_sit)                                \
 348        (le16_to_cpu((raw_sit)->vblocks) & SIT_VBLOCKS_MASK)
 349#define GET_SIT_TYPE(raw_sit)                                   \
 350        ((le16_to_cpu((raw_sit)->vblocks) & ~SIT_VBLOCKS_MASK)  \
 351         >> SIT_VBLOCKS_SHIFT)
 352
 353struct f2fs_sit_entry {
 354        __le16 vblocks;                         /* reference above */
 355        __u8 valid_map[SIT_VBLOCK_MAP_SIZE];    /* bitmap for valid blocks */
 356        __le64 mtime;                           /* segment age for cleaning */
 357} __packed;
 358
 359struct f2fs_sit_block {
 360        struct f2fs_sit_entry entries[SIT_ENTRY_PER_BLOCK];
 361} __packed;
 362
 363/*
 364 * For segment summary
 365 *
 366 * One summary block contains exactly 512 summary entries, which represents
 367 * exactly 2MB segment by default. Not allow to change the basic units.
 368 *
 369 * NOTE: For initializing fields, you must use set_summary
 370 *
 371 * - If data page, nid represents dnode's nid
 372 * - If node page, nid represents the node page's nid.
 373 *
 374 * The ofs_in_node is used by only data page. It represents offset
 375 * from node's page's beginning to get a data block address.
 376 * ex) data_blkaddr = (block_t)(nodepage_start_address + ofs_in_node)
 377 */
 378#define ENTRIES_IN_SUM          512
 379#define SUMMARY_SIZE            (7)     /* sizeof(struct summary) */
 380#define SUM_FOOTER_SIZE         (5)     /* sizeof(struct summary_footer) */
 381#define SUM_ENTRY_SIZE          (SUMMARY_SIZE * ENTRIES_IN_SUM)
 382
 383/* a summary entry for a 4KB-sized block in a segment */
 384struct f2fs_summary {
 385        __le32 nid;             /* parent node id */
 386        union {
 387                __u8 reserved[3];
 388                struct {
 389                        __u8 version;           /* node version number */
 390                        __le16 ofs_in_node;     /* block index in parent node */
 391                } __packed;
 392        };
 393} __packed;
 394
 395/* summary block type, node or data, is stored to the summary_footer */
 396#define SUM_TYPE_NODE           (1)
 397#define SUM_TYPE_DATA           (0)
 398
 399struct summary_footer {
 400        unsigned char entry_type;       /* SUM_TYPE_XXX */
 401        __le32 check_sum;               /* summary checksum */
 402} __packed;
 403
 404#define SUM_JOURNAL_SIZE        (F2FS_BLKSIZE - SUM_FOOTER_SIZE -\
 405                                SUM_ENTRY_SIZE)
 406#define NAT_JOURNAL_ENTRIES     ((SUM_JOURNAL_SIZE - 2) /\
 407                                sizeof(struct nat_journal_entry))
 408#define NAT_JOURNAL_RESERVED    ((SUM_JOURNAL_SIZE - 2) %\
 409                                sizeof(struct nat_journal_entry))
 410#define SIT_JOURNAL_ENTRIES     ((SUM_JOURNAL_SIZE - 2) /\
 411                                sizeof(struct sit_journal_entry))
 412#define SIT_JOURNAL_RESERVED    ((SUM_JOURNAL_SIZE - 2) %\
 413                                sizeof(struct sit_journal_entry))
 414
 415/* Reserved area should make size of f2fs_extra_info equals to
 416 * that of nat_journal and sit_journal.
 417 */
 418#define EXTRA_INFO_RESERVED     (SUM_JOURNAL_SIZE - 2 - 8)
 419
 420/*
 421 * frequently updated NAT/SIT entries can be stored in the spare area in
 422 * summary blocks
 423 */
 424enum {
 425        NAT_JOURNAL = 0,
 426        SIT_JOURNAL
 427};
 428
 429struct nat_journal_entry {
 430        __le32 nid;
 431        struct f2fs_nat_entry ne;
 432} __packed;
 433
 434struct nat_journal {
 435        struct nat_journal_entry entries[NAT_JOURNAL_ENTRIES];
 436        __u8 reserved[NAT_JOURNAL_RESERVED];
 437} __packed;
 438
 439struct sit_journal_entry {
 440        __le32 segno;
 441        struct f2fs_sit_entry se;
 442} __packed;
 443
 444struct sit_journal {
 445        struct sit_journal_entry entries[SIT_JOURNAL_ENTRIES];
 446        __u8 reserved[SIT_JOURNAL_RESERVED];
 447} __packed;
 448
 449struct f2fs_extra_info {
 450        __le64 kbytes_written;
 451        __u8 reserved[EXTRA_INFO_RESERVED];
 452} __packed;
 453
 454struct f2fs_journal {
 455        union {
 456                __le16 n_nats;
 457                __le16 n_sits;
 458        };
 459        /* spare area is used by NAT or SIT journals or extra info */
 460        union {
 461                struct nat_journal nat_j;
 462                struct sit_journal sit_j;
 463                struct f2fs_extra_info info;
 464        };
 465} __packed;
 466
 467/* 4KB-sized summary block structure */
 468struct f2fs_summary_block {
 469        struct f2fs_summary entries[ENTRIES_IN_SUM];
 470        struct f2fs_journal journal;
 471        struct summary_footer footer;
 472} __packed;
 473
 474/*
 475 * For directory operations
 476 */
 477#define F2FS_DOT_HASH           0
 478#define F2FS_DDOT_HASH          F2FS_DOT_HASH
 479#define F2FS_MAX_HASH           (~((0x3ULL) << 62))
 480#define F2FS_HASH_COL_BIT       ((0x1ULL) << 63)
 481
 482typedef __le32  f2fs_hash_t;
 483
 484/* One directory entry slot covers 8bytes-long file name */
 485#define F2FS_SLOT_LEN           8
 486#define F2FS_SLOT_LEN_BITS      3
 487
 488#define GET_DENTRY_SLOTS(x) (((x) + F2FS_SLOT_LEN - 1) >> F2FS_SLOT_LEN_BITS)
 489
 490/* MAX level for dir lookup */
 491#define MAX_DIR_HASH_DEPTH      63
 492
 493/* MAX buckets in one level of dir */
 494#define MAX_DIR_BUCKETS         (1 << ((MAX_DIR_HASH_DEPTH / 2) - 1))
 495
 496/*
 497 * space utilization of regular dentry and inline dentry (w/o extra reservation)
 498 *              regular dentry          inline dentry (def)     inline dentry (min)
 499 * bitmap       1 * 27 = 27             1 * 23 = 23             1 * 1 = 1
 500 * reserved     1 * 3 = 3               1 * 7 = 7               1 * 1 = 1
 501 * dentry       11 * 214 = 2354         11 * 182 = 2002         11 * 2 = 22
 502 * filename     8 * 214 = 1712          8 * 182 = 1456          8 * 2 = 16
 503 * total        4096                    3488                    40
 504 *
 505 * Note: there are more reserved space in inline dentry than in regular
 506 * dentry, when converting inline dentry we should handle this carefully.
 507 */
 508#define NR_DENTRY_IN_BLOCK      214     /* the number of dentry in a block */
 509#define SIZE_OF_DIR_ENTRY       11      /* by byte */
 510#define SIZE_OF_DENTRY_BITMAP   ((NR_DENTRY_IN_BLOCK + BITS_PER_BYTE - 1) / \
 511                                        BITS_PER_BYTE)
 512#define SIZE_OF_RESERVED        (PAGE_SIZE - ((SIZE_OF_DIR_ENTRY + \
 513                                F2FS_SLOT_LEN) * \
 514                                NR_DENTRY_IN_BLOCK + SIZE_OF_DENTRY_BITMAP))
 515#define MIN_INLINE_DENTRY_SIZE          40      /* just include '.' and '..' entries */
 516
 517/* One directory entry slot representing F2FS_SLOT_LEN-sized file name */
 518struct f2fs_dir_entry {
 519        __le32 hash_code;       /* hash code of file name */
 520        __le32 ino;             /* inode number */
 521        __le16 name_len;        /* length of file name */
 522        __u8 file_type;         /* file type */
 523} __packed;
 524
 525/* 4KB-sized directory entry block */
 526struct f2fs_dentry_block {
 527        /* validity bitmap for directory entries in each block */
 528        __u8 dentry_bitmap[SIZE_OF_DENTRY_BITMAP];
 529        __u8 reserved[SIZE_OF_RESERVED];
 530        struct f2fs_dir_entry dentry[NR_DENTRY_IN_BLOCK];
 531        __u8 filename[NR_DENTRY_IN_BLOCK][F2FS_SLOT_LEN];
 532} __packed;
 533
 534/* file types used in inode_info->flags */
 535enum {
 536        F2FS_FT_UNKNOWN,
 537        F2FS_FT_REG_FILE,
 538        F2FS_FT_DIR,
 539        F2FS_FT_CHRDEV,
 540        F2FS_FT_BLKDEV,
 541        F2FS_FT_FIFO,
 542        F2FS_FT_SOCK,
 543        F2FS_FT_SYMLINK,
 544        F2FS_FT_MAX
 545};
 546
 547#define S_SHIFT 12
 548
 549#define F2FS_DEF_PROJID         0       /* default project ID */
 550
 551#endif  /* _LINUX_F2FS_FS_H */
 552
Hosted by Missing Link Electronics. The original LXR software by the LXR community, this experimental version by lxr@linux.no.