lwext4/ext4_types.h

   1 /*
   2  * Copyright (c) 2013 Grzegorz Kostka (kostka.grzegorz@gmail.com)
   3  *
   4  *
   5  * HelenOS:
   6  * Copyright (c) 2012 Martin Sucha
   7  * Copyright (c) 2012 Frantisek Princ
   8  * All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  *
  14  * - Redistributions of source code must retain the above copyright
  15  *   notice, this list of conditions and the following disclaimer.
  16  * - Redistributions in binary form must reproduce the above copyright
  17  *   notice, this list of conditions and the following disclaimer in the
  18  *   documentation and/or other materials provided with the distribution.
  19  * - The name of the author may not be used to endorse or promote products
  20  *   derived from this software without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 /** @addtogroup lwext4
  35  * @{
  36  */
  37 /**
  38  * @file  ext4_types.h
  39  * @brief Ext4 data structure definitions.
  40  */
  41
  42 #ifndef EXT4_TYPES_H_
  43 #define EXT4_TYPES_H_
  44
  45 #include <ext4_config.h>
  46 #include <ext4_blockdev.h>
  47
  48 #include <stdint.h>
  49
  50
  51 /*
  52  * Structure of the super block
  53  */
  54 struct ext4_sblock {
  55     uint32_t inodes_count;              /* I-nodes count */
  56     uint32_t blocks_count_lo;           /* Blocks count */
  57     uint32_t reserved_blocks_count_lo;  /* Reserved blocks count */
  58     uint32_t free_blocks_count_lo;      /* Free blocks count */
  59     uint32_t free_inodes_count;         /* Free inodes count */
  60     uint32_t first_data_block;          /* First Data Block */
  61     uint32_t log_block_size;            /* Block size */
  62     uint32_t log_frag_size;             /* Obsoleted fragment size */
  63     uint32_t blocks_per_group;          /* Number of blocks per group */
  64     uint32_t frags_per_group;           /* Obsoleted fragments per group */
  65     uint32_t inodes_per_group;          /* Number of inodes per group */
  66     uint32_t mount_time;                /* Mount time */
  67     uint32_t write_time;                /* Write time */
  68     uint16_t mount_count;               /* Mount count */
  69     uint16_t max_mount_count;           /* Maximal mount count */
  70     uint16_t magic;                     /* Magic signature */
  71     uint16_t state;                     /* File system state */
  72     uint16_t errors;                    /* Behaviour when detecting errors */
  73     uint16_t minor_rev_level;           /* Minor revision level */
  74     uint32_t last_check_time;           /* Time of last check */
  75     uint32_t check_interval;            /* Maximum time between checks */
  76     uint32_t creator_os;                /* Creator OS */
  77     uint32_t rev_level;                 /* Revision level */
  78     uint16_t def_resuid;                /* Default uid for reserved blocks */
  79     uint16_t def_resgid;                /* Default gid for reserved blocks */
  80
  81     /* Fields for EXT4_DYNAMIC_REV superblocks only. */
  82     uint32_t first_inode;             /* First non-reserved inode */
  83     uint16_t inode_size;              /* Size of inode structure */
  84     uint16_t block_group_index;       /* Block group index of this superblock */
  85     uint32_t features_compatible;     /* Compatible feature set */
  86     uint32_t features_incompatible;   /* Incompatible feature set */
  87     uint32_t features_read_only;      /* Readonly-compatible feature set */
  88     uint8_t uuid[16];                 /* 128-bit uuid for volume */
  89     char volume_name[16];             /* Volume name */
  90     char last_mounted[64];            /* Directory where last mounted */
  91     uint32_t algorithm_usage_bitmap;  /* For compression */
  92
  93     /*
  94      * Performance hints. Directory preallocation should only
  95      * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
  96      */
  97     uint8_t s_prealloc_blocks;       /* Number of blocks to try to preallocate */
  98     uint8_t s_prealloc_dir_blocks;   /* Number to preallocate for dirs */
  99     uint16_t s_reserved_gdt_blocks;  /* Per group desc for online growth */
 100
 101     /*
 102      * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
 103      */
 104     uint8_t journal_uuid[16];       /* UUID of journal superblock */
 105     uint32_t journal_inode_number;  /* Inode number of journal file */
 106     uint32_t journal_dev;           /* Device number of journal file */
 107     uint32_t last_orphan;           /* Head of list of inodes to delete */
 108     uint32_t hash_seed[4];          /* HTREE hash seed */
 109     uint8_t default_hash_version;   /* Default hash version to use */
 110     uint8_t journal_backup_type;
 111     uint16_t desc_size;             /* Size of group descriptor */
 112     uint32_t default_mount_opts;    /* Default mount options */
 113     uint32_t first_meta_bg;         /* First metablock block group */
 114     uint32_t mkfs_time;             /* When the filesystem was created */
 115     uint32_t journal_blocks[17];    /* Backup of the journal inode */
 116
 117     /* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
 118     uint32_t blocks_count_hi;           /* Blocks count */
 119     uint32_t reserved_blocks_count_hi;  /* Reserved blocks count */
 120     uint32_t free_blocks_count_hi;      /* Free blocks count */
 121     uint16_t min_extra_isize;           /* All inodes have at least # bytes */
 122     uint16_t want_extra_isize;          /* New inodes should reserve # bytes */
 123     uint32_t flags;                     /* Miscellaneous flags */
 124     uint16_t raid_stride;               /* RAID stride */
 125     uint16_t mmp_interval;              /* # seconds to wait in MMP checking */
 126     uint64_t mmp_block;                 /* Block for multi-mount protection */
 127     uint32_t raid_stripe_width;         /* Blocks on all data disks (N * stride) */
 128     uint8_t log_groups_per_flex;        /* FLEX_BG group size */
 129     uint8_t reserved_char_pad;
 130     uint16_t reserved_pad;
 131     uint64_t kbytes_written;            /* Number of lifetime kilobytes written */
 132     uint32_t snapshot_inum;             /* I-node number of active snapshot */
 133     uint32_t snapshot_id;               /* Sequential ID of active snapshot */
 134     uint64_t snapshot_r_blocks_count;   /* Reserved blocks for active snapshot's future use */
 135     uint32_t snapshot_list;             /* I-node number of the head of the on-disk snapshot list */
 136     uint32_t error_count;               /* Number of file system errors */
 137     uint32_t first_error_time;          /* First time an error happened */
 138     uint32_t first_error_ino;           /* I-node involved in first error */
 139     uint64_t first_error_block;         /* Block involved of first error */
 140     uint8_t first_error_func[32];       /* Function where the error happened */
 141     uint32_t first_error_line;          /* Line number where error happened */
 142     uint32_t last_error_time;           /* Most recent time of an error */
 143     uint32_t last_error_ino;            /* I-node involved in last error */
 144     uint32_t last_error_line;           /* Line number where error happened */
 145     uint64_t last_error_block;          /* Block involved of last error */
 146     uint8_t last_error_func[32];        /* Function where the error happened */
 147     uint8_t mount_opts[64];
 148     uint32_t padding[112];              /* Padding to the end of the block */
 149 } __attribute__((packed));
 150
 151
 152 #define EXT4_SUPERBLOCK_MAGIC   0xEF53
 153 #define EXT4_SUPERBLOCK_SIZE    1024
 154 #define EXT4_SUPERBLOCK_OFFSET  1024
 155
 156 #define EXT4_SUPERBLOCK_OS_LINUX  0
 157 #define EXT4_SUPERBLOCK_OS_HURD   1
 158
 159 /*
 160  * Misc. filesystem flags
 161  */
 162 #define EXT4_SUPERBLOCK_FLAGS_SIGNED_HASH    0x0001  /* Signed dirhash in use */
 163 #define EXT4_SUPERBLOCK_FLAGS_UNSIGNED_HASH  0x0002  /* Unsigned dirhash in use */
 164 #define EXT4_SUPERBLOCK_FLAGS_TEST_FILESYS   0x0004  /* to test development code */
 165
 166 /*
 167  * Filesystem states
 168  */
 169 #define EXT4_SUPERBLOCK_STATE_VALID_FS   0x0001  /* Unmounted cleanly */
 170 #define EXT4_SUPERBLOCK_STATE_ERROR_FS   0x0002  /* Errors detected */
 171 #define EXT4_SUPERBLOCK_STATE_ORPHAN_FS  0x0004  /* Orphans being recovered */
 172
 173 /*
 174  * Behaviour when errors detected
 175  */
 176 #define EXT4_SUPERBLOCK_ERRORS_CONTINUE  1  /* Continue execution */
 177 #define EXT4_SUPERBLOCK_ERRORS_RO        2  /* Remount fs read-only */
 178 #define EXT4_SUPERBLOCK_ERRORS_PANIC     3  /* Panic */
 179 #define EXT4_SUPERBLOCK_ERRORS_DEFAULT   EXT4_ERRORS_CONTINUE
 180
 181 /*
 182  * Compatible features
 183  */
 184 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC   0x0001
 185 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES  0x0002
 186 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL    0x0004
 187 #define EXT4_FEATURE_COMPAT_EXT_ATTR       0x0008
 188 #define EXT4_FEATURE_COMPAT_RESIZE_INODE   0x0010
 189 #define EXT4_FEATURE_COMPAT_DIR_INDEX      0x0020
 190
 191
 192 /*
 193  * Read-only compatible features
 194  */
 195 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER  0x0001
 196 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE    0x0002
 197 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR     0x0004
 198 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE     0x0008
 199 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM      0x0010
 200 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK     0x0020
 201 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE   0x0040
 202 #define EXT4_FEATURE_RO_COMPAT_QUOTA         0x0100
 203 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC      0x0200
 204 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM 0x0400
 205
 206 /*
 207  * Incompatible features
 208  */
 209 #define EXT4_FEATURE_INCOMPAT_COMPRESSION  0x0001
 210 #define EXT4_FEATURE_INCOMPAT_FILETYPE     0x0002
 211 #define EXT4_FEATURE_INCOMPAT_RECOVER      0x0004  /* Needs recovery */
 212 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV  0x0008  /* Journal device */
 213 #define EXT4_FEATURE_INCOMPAT_META_BG      0x0010
 214 #define EXT4_FEATURE_INCOMPAT_EXTENTS      0x0040  /* extents support */
 215 #define EXT4_FEATURE_INCOMPAT_64BIT        0x0080
 216 #define EXT4_FEATURE_INCOMPAT_MMP          0x0100
 217 #define EXT4_FEATURE_INCOMPAT_FLEX_BG      0x0200
 218 #define EXT4_FEATURE_INCOMPAT_EA_INODE     0x0400  /* EA in inode */
 219 #define EXT4_FEATURE_INCOMPAT_DIRDATA      0x1000  /* data in dirent */
 220 #define EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM  0x2000 /* use crc32c for bg */
 221 #define EXT4_FEATURE_INCOMPAT_LARGEDIR          0x4000 /* >2GB or 3-lvl htree */
 222 #define EXT4_FEATURE_INCOMPAT_INLINE_DATA       0x8000 /* data in inode */
 223
 224
 225 /*
 226  * EXT2 supported feature set
 227  */
 228 #define EXT2_FEATURE_COMPAT_SUPP    0x0000
 229
 230 #define EXT2_FEATURE_INCOMPAT_SUPP                    \
 231             (EXT4_FEATURE_INCOMPAT_FILETYPE         | \
 232              EXT4_FEATURE_INCOMPAT_META_BG)
 233
 234 #define EXT2_FEATURE_RO_COMPAT_SUPP                   \
 235             (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER    | \
 236              EXT4_FEATURE_RO_COMPAT_LARGE_FILE      | \
 237              EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
 238
 239 /*
 240  * EXT3 supported feature set
 241  */
 242 #define EXT3_FEATURE_COMPAT_SUPP                      \
 243             (EXT4_FEATURE_COMPAT_DIR_INDEX)
 244
 245 #define EXT3_FEATURE_INCOMPAT_SUPP                    \
 246             (EXT4_FEATURE_INCOMPAT_FILETYPE         | \
 247              EXT4_FEATURE_INCOMPAT_META_BG)
 248
 249 #define EXT3_FEATURE_RO_COMPAT_SUPP                   \
 250             (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER    | \
 251              EXT4_FEATURE_RO_COMPAT_LARGE_FILE      | \
 252              EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
 253
 254 /*
 255  * EXT4 supported feature set
 256  */
 257 #define EXT4_FEATURE_COMPAT_SUPP                      \
 258             (EXT4_FEATURE_COMPAT_DIR_INDEX)
 259
 260 #define EXT4_FEATURE_INCOMPAT_SUPP                    \
 261             (EXT4_FEATURE_INCOMPAT_FILETYPE         | \
 262             EXT4_FEATURE_INCOMPAT_META_BG           | \
 263             EXT4_FEATURE_INCOMPAT_EXTENTS           | \
 264             EXT4_FEATURE_INCOMPAT_64BIT)
 265
 266 #define EXT4_FEATURE_RO_COMPAT_SUPP                   \
 267             (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER    | \
 268             EXT4_FEATURE_RO_COMPAT_LARGE_FILE       | \
 269             EXT4_FEATURE_RO_COMPAT_GDT_CSUM         | \
 270             EXT4_FEATURE_RO_COMPAT_DIR_NLINK        | \
 271             EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE      | \
 272             EXT4_FEATURE_RO_COMPAT_BTREE_DIR        | \
 273             EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
 274
 275
 276 /*Ignored features:
 277  * RECOVER - journaling in lwext4 is not supported
 278  *           (probably won,t be ever...)
 279  * MMP - multi mout protection (impossible scenario)
 280  * */
 281 #define FEATURE_INCOMPAT_IGNORED                      \
 282         EXT4_FEATURE_INCOMPAT_RECOVER               | \
 283         EXT4_FEATURE_INCOMPAT_MMP)
 284
 285 #if 0
 286 /*TODO: Features incompatible to implement*/
 287 #define EXT4_FEATURE_INCOMPAT_SUPP
 288                      EXT4_FEATURE_INCOMPAT_FLEX_BG| \
 289                      EXT4_FEATURE_INCOMPAT_INLINE_DATA)
 290
 291 /*TODO: Features read only to implement*/
 292 #define EXT4_FEATURE_RO_COMPAT_SUPP
 293                      EXT4_FEATURE_RO_COMPAT_BIGALLOC |\
 294                      EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
 295                      EXT4_FEATURE_RO_COMPAT_QUOTA)
 296 #endif
 297
 298 struct ext4_fs {
 299     struct ext4_blockdev*bdev;
 300     struct ext4_sblock sb;
 301
 302     uint64_t inode_block_limits[4];
 303     uint64_t inode_blocks_per_level[4];
 304
 305     uint32_t last_inode_bg_id;
 306 };
 307
 308
 309 #define EXT4_BLOCK_GROUP_INODE_UNINIT   0x0001  /* Inode table/bitmap not in use */
 310 #define EXT4_BLOCK_GROUP_BLOCK_UNINIT   0x0002  /* Block bitmap not in use */
 311 #define EXT4_BLOCK_GROUP_ITABLE_ZEROED  0x0004  /* On-disk itable initialized to zero */
 312
 313 /*
 314  * Structure of a blocks group descriptor
 315  */
 316 struct ext4_bgroup {
 317     uint32_t block_bitmap_lo;             /* Blocks bitmap block */
 318     uint32_t inode_bitmap_lo;             /* Inodes bitmap block */
 319     uint32_t inode_table_first_block_lo;  /* Inodes table block */
 320     uint16_t free_blocks_count_lo;        /* Free blocks count */
 321     uint16_t free_inodes_count_lo;        /* Free inodes count */
 322     uint16_t used_dirs_count_lo;          /* Directories count */
 323     uint16_t flags;                       /* EXT4_BG_flags (INODE_UNINIT, etc) */
 324     uint32_t exclude_bitmap_lo;           /* Exclude bitmap for snapshots */
 325         uint16_t block_bitmap_csum_lo;        /* crc32c(s_uuid+grp_num+bbitmap) LE */
 326         uint16_t inode_bitmap_csum_lo;        /* crc32c(s_uuid+grp_num+ibitmap) LE */
 327     uint16_t itable_unused_lo;            /* Unused inodes count */
 328     uint16_t checksum;                    /* crc16(sb_uuid+group+desc) */
 329
 330     uint32_t block_bitmap_hi;             /* Blocks bitmap block MSB */
 331     uint32_t inode_bitmap_hi;             /* I-nodes bitmap block MSB */
 332     uint32_t inode_table_first_block_hi;  /* I-nodes table block MSB */
 333     uint16_t free_blocks_count_hi;        /* Free blocks count MSB */
 334     uint16_t free_inodes_count_hi;        /* Free i-nodes count MSB */
 335     uint16_t used_dirs_count_hi;          /* Directories count MSB */
 336     uint16_t itable_unused_hi;            /* Unused inodes count MSB */
 337     uint32_t exclude_bitmap_hi;           /* Exclude bitmap block MSB */
 338         uint16_t block_bitmap_csum_hi;        /* crc32c(s_uuid+grp_num+bbitmap) BE */
 339         uint16_t inode_bitmap_csum_hi;        /* crc32c(s_uuid+grp_num+ibitmap) BE */
 340         uint32_t reserved;                    /* Padding */
 341 } ;
 342
 343 struct ext4_block_group_ref {
 344     struct ext4_block block;
 345     struct ext4_bgroup *block_group;
 346     struct ext4_fs *fs;
 347     uint32_t index;
 348     bool dirty;
 349 };
 350
 351 #define EXT4_MIN_BLOCK_GROUP_DESCRIPTOR_SIZE  32
 352 #define EXT4_MAX_BLOCK_GROUP_DESCRIPTOR_SIZE  64
 353
 354 #define EXT4_MIN_BLOCK_SIZE   1024   /* 1 KiB */
 355 #define EXT4_MAX_BLOCK_SIZE   65536  /* 64 KiB */
 356 #define EXT4_REV0_INODE_SIZE  128
 357
 358 #define EXT4_INODE_BLOCK_SIZE  512
 359
 360 #define EXT4_INODE_DIRECT_BLOCK_COUNT      12
 361 #define EXT4_INODE_INDIRECT_BLOCK          EXT4_INODE_DIRECT_BLOCK_COUNT
 362 #define EXT4_INODE_DOUBLE_INDIRECT_BLOCK   (EXT4_INODE_INDIRECT_BLOCK + 1)
 363 #define EXT4_INODE_TRIPPLE_INDIRECT_BLOCK  (EXT4_INODE_DOUBLE_INDIRECT_BLOCK + 1)
 364 #define EXT4_INODE_BLOCKS                  (EXT4_INODE_TRIPPLE_INDIRECT_BLOCK + 1)
 365 #define EXT4_INODE_INDIRECT_BLOCK_COUNT    (EXT4_INODE_BLOCKS - EXT4_INODE_DIRECT_BLOCK_COUNT)
 366
 367 /*
 368  * Structure of an inode on the disk
 369  */
 370 struct ext4_inode {
 371     uint16_t mode;                       /* File mode */
 372     uint16_t uid;                        /* Low 16 bits of owner uid */
 373     uint32_t size_lo;                    /* Size in bytes */
 374     uint32_t access_time;                /* Access time */
 375     uint32_t change_inode_time;          /* I-node change time */
 376     uint32_t modification_time;          /* Modification time */
 377     uint32_t deletion_time;              /* Deletion time */
 378     uint16_t gid;                        /* Low 16 bits of group id */
 379     uint16_t links_count;                /* Links count */
 380     uint32_t blocks_count_lo;            /* Blocks count */
 381     uint32_t flags;                      /* File flags */
 382     uint32_t unused_osd1;                /* OS dependent - not used in HelenOS */
 383     uint32_t blocks[EXT4_INODE_BLOCKS];  /* Pointers to blocks */
 384     uint32_t generation;                 /* File version (for NFS) */
 385     uint32_t file_acl_lo;                /* File ACL */
 386     uint32_t size_hi;
 387     uint32_t obso_faddr;                 /* Obsoleted fragment address */
 388
 389     union {
 390         struct {
 391             uint16_t blocks_high;
 392             uint16_t file_acl_high;
 393             uint16_t uid_high;
 394             uint16_t gid_high;
 395             uint32_t reserved2;
 396         } linux2;
 397         struct {
 398             uint16_t reserved1;
 399             uint16_t mode_high;
 400             uint16_t uid_high;
 401             uint16_t gid_high;
 402             uint32_t author;
 403         } hurd2;
 404     } __attribute__ ((packed)) osd2;
 405
 406     uint16_t extra_isize;
 407     uint16_t pad1;
 408     uint32_t ctime_extra;   /* Extra change time (nsec << 2 | epoch) */
 409     uint32_t mtime_extra;   /* Extra Modification time (nsec << 2 | epoch) */
 410     uint32_t atime_extra;   /* Extra Access time (nsec << 2 | epoch) */
 411     uint32_t crtime;        /* File creation time */
 412     uint32_t crtime_extra;  /* Extra file creation time (nsec << 2 | epoch) */
 413     uint32_t version_hi;    /* High 32 bits for 64-bit version */
 414 } __attribute__ ((packed)) ;
 415
 416 #define EXT4_INODE_MODE_FIFO       0x1000
 417 #define EXT4_INODE_MODE_CHARDEV    0x2000
 418 #define EXT4_INODE_MODE_DIRECTORY  0x4000
 419 #define EXT4_INODE_MODE_BLOCKDEV   0x6000
 420 #define EXT4_INODE_MODE_FILE       0x8000
 421 #define EXT4_INODE_MODE_SOFTLINK   0xA000
 422 #define EXT4_INODE_MODE_SOCKET     0xC000
 423 #define EXT4_INODE_MODE_TYPE_MASK  0xF000
 424
 425 /*
 426  * Inode flags
 427  */
 428 #define EXT4_INODE_FLAG_SECRM      0x00000001  /* Secure deletion */
 429 #define EXT4_INODE_FLAG_UNRM       0x00000002  /* Undelete */
 430 #define EXT4_INODE_FLAG_COMPR      0x00000004  /* Compress file */
 431 #define EXT4_INODE_FLAG_SYNC       0x00000008  /* Synchronous updates */
 432 #define EXT4_INODE_FLAG_IMMUTABLE  0x00000010  /* Immutable file */
 433 #define EXT4_INODE_FLAG_APPEND     0x00000020  /* writes to file may only append */
 434 #define EXT4_INODE_FLAG_NODUMP     0x00000040  /* do not dump file */
 435 #define EXT4_INODE_FLAG_NOATIME    0x00000080  /* do not update atime */
 436
 437 /* Compression flags */
 438 #define EXT4_INODE_FLAG_DIRTY     0x00000100
 439 #define EXT4_INODE_FLAG_COMPRBLK  0x00000200  /* One or more compressed clusters */
 440 #define EXT4_INODE_FLAG_NOCOMPR   0x00000400  /* Don't compress */
 441 #define EXT4_INODE_FLAG_ECOMPR    0x00000800  /* Compression error */
 442
 443 #define EXT4_INODE_FLAG_INDEX         0x00001000  /* hash-indexed directory */
 444 #define EXT4_INODE_FLAG_IMAGIC        0x00002000  /* AFS directory */
 445 #define EXT4_INODE_FLAG_JOURNAL_DATA  0x00004000  /* File data should be journaled */
 446 #define EXT4_INODE_FLAG_NOTAIL        0x00008000  /* File tail should not be merged */
 447 #define EXT4_INODE_FLAG_DIRSYNC       0x00010000  /* Dirsync behaviour (directories only) */
 448 #define EXT4_INODE_FLAG_TOPDIR        0x00020000  /* Top of directory hierarchies */
 449 #define EXT4_INODE_FLAG_HUGE_FILE     0x00040000  /* Set to each huge file */
 450 #define EXT4_INODE_FLAG_EXTENTS       0x00080000  /* Inode uses extents */
 451 #define EXT4_INODE_FLAG_EA_INODE      0x00200000  /* Inode used for large EA */
 452 #define EXT4_INODE_FLAG_EOFBLOCKS     0x00400000  /* Blocks allocated beyond EOF */
 453 #define EXT4_INODE_FLAG_RESERVED      0x80000000  /* reserved for ext4 lib */
 454
 455 #define EXT4_INODE_ROOT_INDEX  2
 456
 457 struct ext4_inode_ref {
 458     struct ext4_block  block;
 459     struct ext4_inode *inode;
 460     struct ext4_fs  *fs;
 461     uint32_t index;
 462     bool dirty;
 463 } ;
 464
 465
 466 #define EXT4_DIRECTORY_FILENAME_LEN  255
 467
 468 #define EXT4_DIRECTORY_FILETYPE_UNKNOWN   0
 469 #define EXT4_DIRECTORY_FILETYPE_REG_FILE  1
 470 #define EXT4_DIRECTORY_FILETYPE_DIR       2
 471 #define EXT4_DIRECTORY_FILETYPE_CHRDEV    3
 472 #define EXT4_DIRECTORY_FILETYPE_BLKDEV    4
 473 #define EXT4_DIRECTORY_FILETYPE_FIFO      5
 474 #define EXT4_DIRECTORY_FILETYPE_SOCK      6
 475 #define EXT4_DIRECTORY_FILETYPE_SYMLINK   7
 476
 477 union ext4_directory_entry_ll_internal{
 478     uint8_t name_length_high;  /* Higher 8 bits of name length */
 479     uint8_t inode_type;        /* Type of referenced inode (in rev >= 0.5) */
 480 } __attribute__ ((packed));
 481
 482 /**
 483  * Linked list directory entry structure
 484  */
 485 struct ext4_directory_entry_ll {
 486     uint32_t inode;         /* I-node for the entry */
 487     uint16_t entry_length;  /* Distance to the next directory entry */
 488     uint8_t name_length;    /* Lower 8 bits of name length */
 489
 490     union ext4_directory_entry_ll_internal in;
 491
 492     uint8_t name[EXT4_DIRECTORY_FILENAME_LEN];  /* Entry name */
 493 } __attribute__((packed)) ;
 494
 495 struct ext4_directory_iterator {
 496     struct ext4_inode_ref *inode_ref;
 497     struct ext4_block current_block;
 498     uint64_t current_offset;
 499     struct ext4_directory_entry_ll  *current;
 500 };
 501
 502 struct ext4_directory_search_result {
 503     struct ext4_block block;
 504     struct ext4_directory_entry_ll *dentry;
 505 };
 506
 507 /* Structures for indexed directory */
 508
 509 struct ext4_directory_dx_countlimit {
 510     uint16_t limit;
 511     uint16_t count;
 512 } ;
 513
 514 struct ext4_directory_dx_dot_entry {
 515     uint32_t inode;
 516     uint16_t entry_length;
 517     uint8_t name_length;
 518     uint8_t inode_type;
 519     uint8_t name[4];
 520 } ;
 521
 522 struct ext4_directory_dx_root_info {
 523     uint32_t reserved_zero;
 524     uint8_t hash_version;
 525     uint8_t info_length;
 526     uint8_t indirect_levels;
 527     uint8_t unused_flags;
 528 } ;
 529
 530 struct ext4_directory_dx_entry {
 531     uint32_t hash;
 532     uint32_t block;
 533 } ;
 534
 535 struct ext4_directory_dx_root {
 536     struct ext4_directory_dx_dot_entry dots[2];
 537     struct ext4_directory_dx_root_info info;
 538     struct ext4_directory_dx_entry entries[];
 539 };
 540
 541 struct ext4_fake_directory_entry {
 542     uint32_t inode;
 543     uint16_t entry_length;
 544     uint8_t name_length;
 545     uint8_t inode_type;
 546 };
 547
 548 struct ext4_directory_dx_node {
 549     struct ext4_fake_directory_entry fake;
 550     struct ext4_directory_dx_entry entries[];
 551 };
 552
 553 struct ext4_directory_dx_block {
 554     struct ext4_block block;
 555     struct ext4_directory_dx_entry *entries;
 556     struct ext4_directory_dx_entry *position;
 557 } ;
 558
 559 #define EXT4_ERR_BAD_DX_DIR       (-25000)
 560
 561
 562 /*
 563  * This is the extent on-disk structure.
 564  * It's used at the bottom of the tree.
 565  */
 566 struct ext4_extent {
 567     uint32_t first_block;  /* First logical block extent covers */
 568     uint16_t block_count;  /* Number of blocks covered by extent */
 569     uint16_t start_hi;     /* High 16 bits of physical block */
 570     uint32_t start_lo;     /* Low 32 bits of physical block */
 571 } ;
 572
 573 /*
 574  * This is index on-disk structure.
 575  * It's used at all the levels except the bottom.
 576  */
 577 struct ext4_extent_index {
 578     uint32_t first_block;  /* Index covers logical blocks from 'block' */
 579
 580     /**
 581      * Pointer to the physical block of the next
 582      * level. leaf or next index could be there
 583      * high 16 bits of physical block
 584      */
 585     uint32_t leaf_lo;
 586     uint16_t leaf_hi;
 587     uint16_t padding;
 588 } ;
 589
 590 /*
 591  * Each block (leaves and indexes), even inode-stored has header.
 592  */
 593 struct ext4_extent_header {
 594     uint16_t magic;
 595     uint16_t entries_count;      /* Number of valid entries */
 596     uint16_t max_entries_count;  /* Capacity of store in entries */
 597     uint16_t depth;              /* Has tree real underlying blocks? */
 598     uint32_t generation;         /* generation of the tree */
 599 } ;
 600
 601 struct ext4_extent_path {
 602     struct ext4_block block;
 603     uint16_t depth;
 604     struct ext4_extent_header *header;
 605     struct ext4_extent_index *index;
 606     struct ext4_extent *extent;
 607 } ;
 608
 609 #define EXT4_EXTENT_MAGIC  0xF30A
 610
 611 #define EXT4_EXTENT_FIRST(header) \
 612         ((struct ext4_extent *) (((char *) (header)) + sizeof(struct ext4_extent_header)))
 613
 614 #define EXT4_EXTENT_FIRST_INDEX(header) \
 615         ((struct ext4_extent_index *) (((char *) (header)) + sizeof(struct ext4_extent_header)))
 616
 617
 618 /* EXT3 HTree directory indexing */
 619 #define EXT2_HTREE_LEGACY                   0
 620 #define EXT2_HTREE_HALF_MD4                 1
 621 #define EXT2_HTREE_TEA                      2
 622 #define EXT2_HTREE_LEGACY_UNSIGNED          3
 623 #define EXT2_HTREE_HALF_MD4_UNSIGNED        4
 624 #define EXT2_HTREE_TEA_UNSIGNED             5
 625
 626 #define EXT2_HTREE_EOF                      0x7FFFFFFFUL
 627
 628
 629 struct ext4_hash_info {
 630     uint32_t hash;
 631     uint32_t minor_hash;
 632     uint32_t hash_version;
 633     const uint32_t *seed;
 634 };
 635
 636 /*****************************************************************************/
 637
 638
 639 #ifdef CONFIG_BIG_ENDIAN
 640 static inline uint64_t to_le64(uint64_t n)
 641 {
 642     return  ((n & 0xff) << 56) |
 643             ((n & 0xff00) << 40) |
 644             ((n & 0xff0000) << 24) |
 645             ((n & 0xff000000LL) << 8) |
 646             ((n & 0xff00000000LL) >> 8) |
 647             ((n & 0xff0000000000LL) >> 24) |
 648             ((n & 0xff000000000000LL) >> 40) |
 649             ((n & 0xff00000000000000LL) >> 56);
 650 }
 651
 652 static inline uint32_t to_le32(uint32_t n)
 653 {
 654     return  ((n & 0xff) << 24) |
 655             ((n & 0xff00) << 8) |
 656             ((n & 0xff0000) >> 8) |
 657             ((n & 0xff000000) >> 24);
 658 }
 659
 660 static inline uint16_t to_le16(uint16_t n)
 661 {
 662     return  ((n & 0xff) << 8) |
 663             ((n & 0xff00) >> 8);
 664 }
 665
 666
 667 #else
 668 #define to_le64(_n) _n
 669 #define to_le32(_n) _n
 670 #define to_le16(_n) _n
 671 #endif
 672
 673 /****************************Access macros to ext4 structures*****************/
 674
 675 #define ext4_get32(s, f)        to_le32((s)->f)
 676 #define ext4_get16(s, f)        to_le16((s)->f)
 677 #define ext4_get8(s, f)         (s)->f
 678
 679
 680 #define ext4_set32(s, f, v)     do { (s)->f = to_le32(v); }while(0)
 681 #define ext4_set16(s, f, v)     do { (s)->f = to_le16(v); }while(0)
 682 #define ext4_set8 (s, f, v)     do { (s)->f = (v);        }while(0)
 683
 684 #endif /* EXT4_TYPES_H_ */
 685
 686 /**
 687  * @}
 688  */