linux/fs/ext2/ext2.h
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   1/*
   2 * Copyright (C) 1992, 1993, 1994, 1995
   3 * Remy Card (card@masi.ibp.fr)
   4 * Laboratoire MASI - Institut Blaise Pascal
   5 * Universite Pierre et Marie Curie (Paris VI)
   6 *
   7 *  from
   8 *
   9 *  linux/include/linux/minix_fs.h
  10 *
  11 *  Copyright (C) 1991, 1992  Linus Torvalds
  12 */
  13#include <linux/fs.h>
  14#include <linux/ext2_fs.h>
  15#include <linux/blockgroup_lock.h>
  16#include <linux/percpu_counter.h>
  17#include <linux/rbtree.h>
  18
  19/* XXX Here for now... not interested in restructing headers JUST now */
  20
  21/* data type for block offset of block group */
  22typedef int ext2_grpblk_t;
  23
  24/* data type for filesystem-wide blocks number */
  25typedef unsigned long ext2_fsblk_t;
  26
  27#define E2FSBLK "%lu"
  28
  29struct ext2_reserve_window {
  30        ext2_fsblk_t            _rsv_start;     /* First byte reserved */
  31        ext2_fsblk_t            _rsv_end;       /* Last byte reserved or 0 */
  32};
  33
  34struct ext2_reserve_window_node {
  35        struct rb_node          rsv_node;
  36        __u32                   rsv_goal_size;
  37        __u32                   rsv_alloc_hit;
  38        struct ext2_reserve_window      rsv_window;
  39};
  40
  41struct ext2_block_alloc_info {
  42        /* information about reservation window */
  43        struct ext2_reserve_window_node rsv_window_node;
  44        /*
  45         * was i_next_alloc_block in ext2_inode_info
  46         * is the logical (file-relative) number of the
  47         * most-recently-allocated block in this file.
  48         * We use this for detecting linearly ascending allocation requests.
  49         */
  50        __u32                   last_alloc_logical_block;
  51        /*
  52         * Was i_next_alloc_goal in ext2_inode_info
  53         * is the *physical* companion to i_next_alloc_block.
  54         * it the the physical block number of the block which was most-recentl
  55         * allocated to this file.  This give us the goal (target) for the next
  56         * allocation when we detect linearly ascending requests.
  57         */
  58        ext2_fsblk_t            last_alloc_physical_block;
  59};
  60
  61#define rsv_start rsv_window._rsv_start
  62#define rsv_end rsv_window._rsv_end
  63
  64/*
  65 * second extended-fs super-block data in memory
  66 */
  67struct ext2_sb_info {
  68        unsigned long s_frag_size;      /* Size of a fragment in bytes */
  69        unsigned long s_frags_per_block;/* Number of fragments per block */
  70        unsigned long s_inodes_per_block;/* Number of inodes per block */
  71        unsigned long s_frags_per_group;/* Number of fragments in a group */
  72        unsigned long s_blocks_per_group;/* Number of blocks in a group */
  73        unsigned long s_inodes_per_group;/* Number of inodes in a group */
  74        unsigned long s_itb_per_group;  /* Number of inode table blocks per group */
  75        unsigned long s_gdb_count;      /* Number of group descriptor blocks */
  76        unsigned long s_desc_per_block; /* Number of group descriptors per block */
  77        unsigned long s_groups_count;   /* Number of groups in the fs */
  78        unsigned long s_overhead_last;  /* Last calculated overhead */
  79        unsigned long s_blocks_last;    /* Last seen block count */
  80        struct buffer_head * s_sbh;     /* Buffer containing the super block */
  81        struct ext2_super_block * s_es; /* Pointer to the super block in the buffer */
  82        struct buffer_head ** s_group_desc;
  83        unsigned long  s_mount_opt;
  84        unsigned long s_sb_block;
  85        kuid_t s_resuid;
  86        kgid_t s_resgid;
  87        unsigned short s_mount_state;
  88        unsigned short s_pad;
  89        int s_addr_per_block_bits;
  90        int s_desc_per_block_bits;
  91        int s_inode_size;
  92        int s_first_ino;
  93        spinlock_t s_next_gen_lock;
  94        u32 s_next_generation;
  95        unsigned long s_dir_count;
  96        u8 *s_debts;
  97        struct percpu_counter s_freeblocks_counter;
  98        struct percpu_counter s_freeinodes_counter;
  99        struct percpu_counter s_dirs_counter;
 100        struct blockgroup_lock *s_blockgroup_lock;
 101        /* root of the per fs reservation window tree */
 102        spinlock_t s_rsv_window_lock;
 103        struct rb_root s_rsv_window_root;
 104        struct ext2_reserve_window_node s_rsv_window_head;
 105        /*
 106         * s_lock protects against concurrent modifications of s_mount_state,
 107         * s_blocks_last, s_overhead_last and the content of superblock's
 108         * buffer pointed to by sbi->s_es.
 109         *
 110         * Note: It is used in ext2_show_options() to provide a consistent view
 111         * of the mount options.
 112         */
 113        spinlock_t s_lock;
 114};
 115
 116static inline spinlock_t *
 117sb_bgl_lock(struct ext2_sb_info *sbi, unsigned int block_group)
 118{
 119        return bgl_lock_ptr(sbi->s_blockgroup_lock, block_group);
 120}
 121
 122/*
 123 * Define EXT2FS_DEBUG to produce debug messages
 124 */
 125#undef EXT2FS_DEBUG
 126
 127/*
 128 * Define EXT2_RESERVATION to reserve data blocks for expanding files
 129 */
 130#define EXT2_DEFAULT_RESERVE_BLOCKS     8
 131/*max window size: 1024(direct blocks) + 3([t,d]indirect blocks) */
 132#define EXT2_MAX_RESERVE_BLOCKS         1027
 133#define EXT2_RESERVE_WINDOW_NOT_ALLOCATED 0
 134/*
 135 * The second extended file system version
 136 */
 137#define EXT2FS_DATE             "95/08/09"
 138#define EXT2FS_VERSION          "0.5b"
 139
 140/*
 141 * Debug code
 142 */
 143#ifdef EXT2FS_DEBUG
 144#       define ext2_debug(f, a...)      { \
 145                                        printk ("EXT2-fs DEBUG (%s, %d): %s:", \
 146                                                __FILE__, __LINE__, __func__); \
 147                                        printk (f, ## a); \
 148                                        }
 149#else
 150#       define ext2_debug(f, a...)      /**/
 151#endif
 152
 153/*
 154 * Special inode numbers
 155 */
 156#define EXT2_BAD_INO             1      /* Bad blocks inode */
 157#define EXT2_ROOT_INO            2      /* Root inode */
 158#define EXT2_BOOT_LOADER_INO     5      /* Boot loader inode */
 159#define EXT2_UNDEL_DIR_INO       6      /* Undelete directory inode */
 160
 161/* First non-reserved inode for old ext2 filesystems */
 162#define EXT2_GOOD_OLD_FIRST_INO 11
 163
 164static inline struct ext2_sb_info *EXT2_SB(struct super_block *sb)
 165{
 166        return sb->s_fs_info;
 167}
 168
 169/*
 170 * Macro-instructions used to manage several block sizes
 171 */
 172#define EXT2_MIN_BLOCK_SIZE             1024
 173#define EXT2_MAX_BLOCK_SIZE             4096
 174#define EXT2_MIN_BLOCK_LOG_SIZE           10
 175#define EXT2_BLOCK_SIZE(s)              ((s)->s_blocksize)
 176#define EXT2_ADDR_PER_BLOCK(s)          (EXT2_BLOCK_SIZE(s) / sizeof (__u32))
 177#define EXT2_BLOCK_SIZE_BITS(s)         ((s)->s_blocksize_bits)
 178#define EXT2_ADDR_PER_BLOCK_BITS(s)     (EXT2_SB(s)->s_addr_per_block_bits)
 179#define EXT2_INODE_SIZE(s)              (EXT2_SB(s)->s_inode_size)
 180#define EXT2_FIRST_INO(s)               (EXT2_SB(s)->s_first_ino)
 181
 182/*
 183 * Macro-instructions used to manage fragments
 184 */
 185#define EXT2_MIN_FRAG_SIZE              1024
 186#define EXT2_MAX_FRAG_SIZE              4096
 187#define EXT2_MIN_FRAG_LOG_SIZE            10
 188#define EXT2_FRAG_SIZE(s)               (EXT2_SB(s)->s_frag_size)
 189#define EXT2_FRAGS_PER_BLOCK(s)         (EXT2_SB(s)->s_frags_per_block)
 190
 191/*
 192 * Structure of a blocks group descriptor
 193 */
 194struct ext2_group_desc
 195{
 196        __le32  bg_block_bitmap;                /* Blocks bitmap block */
 197        __le32  bg_inode_bitmap;                /* Inodes bitmap block */
 198        __le32  bg_inode_table;         /* Inodes table block */
 199        __le16  bg_free_blocks_count;   /* Free blocks count */
 200        __le16  bg_free_inodes_count;   /* Free inodes count */
 201        __le16  bg_used_dirs_count;     /* Directories count */
 202        __le16  bg_pad;
 203        __le32  bg_reserved[3];
 204};
 205
 206/*
 207 * Macro-instructions used to manage group descriptors
 208 */
 209#define EXT2_BLOCKS_PER_GROUP(s)        (EXT2_SB(s)->s_blocks_per_group)
 210#define EXT2_DESC_PER_BLOCK(s)          (EXT2_SB(s)->s_desc_per_block)
 211#define EXT2_INODES_PER_GROUP(s)        (EXT2_SB(s)->s_inodes_per_group)
 212#define EXT2_DESC_PER_BLOCK_BITS(s)     (EXT2_SB(s)->s_desc_per_block_bits)
 213
 214/*
 215 * Constants relative to the data blocks
 216 */
 217#define EXT2_NDIR_BLOCKS                12
 218#define EXT2_IND_BLOCK                  EXT2_NDIR_BLOCKS
 219#define EXT2_DIND_BLOCK                 (EXT2_IND_BLOCK + 1)
 220#define EXT2_TIND_BLOCK                 (EXT2_DIND_BLOCK + 1)
 221#define EXT2_N_BLOCKS                   (EXT2_TIND_BLOCK + 1)
 222
 223/*
 224 * Inode flags (GETFLAGS/SETFLAGS)
 225 */
 226#define EXT2_SECRM_FL                   FS_SECRM_FL     /* Secure deletion */
 227#define EXT2_UNRM_FL                    FS_UNRM_FL      /* Undelete */
 228#define EXT2_COMPR_FL                   FS_COMPR_FL     /* Compress file */
 229#define EXT2_SYNC_FL                    FS_SYNC_FL      /* Synchronous updates */
 230#define EXT2_IMMUTABLE_FL               FS_IMMUTABLE_FL /* Immutable file */
 231#define EXT2_APPEND_FL                  FS_APPEND_FL    /* writes to file may only append */
 232#define EXT2_NODUMP_FL                  FS_NODUMP_FL    /* do not dump file */
 233#define EXT2_NOATIME_FL                 FS_NOATIME_FL   /* do not update atime */
 234/* Reserved for compression usage... */
 235#define EXT2_DIRTY_FL                   FS_DIRTY_FL
 236#define EXT2_COMPRBLK_FL                FS_COMPRBLK_FL  /* One or more compressed clusters */
 237#define EXT2_NOCOMP_FL                  FS_NOCOMP_FL    /* Don't compress */
 238#define EXT2_ECOMPR_FL                  FS_ECOMPR_FL    /* Compression error */
 239/* End compression flags --- maybe not all used */      
 240#define EXT2_BTREE_FL                   FS_BTREE_FL     /* btree format dir */
 241#define EXT2_INDEX_FL                   FS_INDEX_FL     /* hash-indexed directory */
 242#define EXT2_IMAGIC_FL                  FS_IMAGIC_FL    /* AFS directory */
 243#define EXT2_JOURNAL_DATA_FL            FS_JOURNAL_DATA_FL /* Reserved for ext3 */
 244#define EXT2_NOTAIL_FL                  FS_NOTAIL_FL    /* file tail should not be merged */
 245#define EXT2_DIRSYNC_FL                 FS_DIRSYNC_FL   /* dirsync behaviour (directories only) */
 246#define EXT2_TOPDIR_FL                  FS_TOPDIR_FL    /* Top of directory hierarchies*/
 247#define EXT2_RESERVED_FL                FS_RESERVED_FL  /* reserved for ext2 lib */
 248
 249#define EXT2_FL_USER_VISIBLE            FS_FL_USER_VISIBLE      /* User visible flags */
 250#define EXT2_FL_USER_MODIFIABLE         FS_FL_USER_MODIFIABLE   /* User modifiable flags */
 251
 252/* Flags that should be inherited by new inodes from their parent. */
 253#define EXT2_FL_INHERITED (EXT2_SECRM_FL | EXT2_UNRM_FL | EXT2_COMPR_FL |\
 254                           EXT2_SYNC_FL | EXT2_NODUMP_FL |\
 255                           EXT2_NOATIME_FL | EXT2_COMPRBLK_FL |\
 256                           EXT2_NOCOMP_FL | EXT2_JOURNAL_DATA_FL |\
 257                           EXT2_NOTAIL_FL | EXT2_DIRSYNC_FL)
 258
 259/* Flags that are appropriate for regular files (all but dir-specific ones). */
 260#define EXT2_REG_FLMASK (~(EXT2_DIRSYNC_FL | EXT2_TOPDIR_FL))
 261
 262/* Flags that are appropriate for non-directories/regular files. */
 263#define EXT2_OTHER_FLMASK (EXT2_NODUMP_FL | EXT2_NOATIME_FL)
 264
 265/* Mask out flags that are inappropriate for the given type of inode. */
 266static inline __u32 ext2_mask_flags(umode_t mode, __u32 flags)
 267{
 268        if (S_ISDIR(mode))
 269                return flags;
 270        else if (S_ISREG(mode))
 271                return flags & EXT2_REG_FLMASK;
 272        else
 273                return flags & EXT2_OTHER_FLMASK;
 274}
 275
 276/*
 277 * ioctl commands
 278 */
 279#define EXT2_IOC_GETFLAGS               FS_IOC_GETFLAGS
 280#define EXT2_IOC_SETFLAGS               FS_IOC_SETFLAGS
 281#define EXT2_IOC_GETVERSION             FS_IOC_GETVERSION
 282#define EXT2_IOC_SETVERSION             FS_IOC_SETVERSION
 283#define EXT2_IOC_GETRSVSZ               _IOR('f', 5, long)
 284#define EXT2_IOC_SETRSVSZ               _IOW('f', 6, long)
 285
 286/*
 287 * ioctl commands in 32 bit emulation
 288 */
 289#define EXT2_IOC32_GETFLAGS             FS_IOC32_GETFLAGS
 290#define EXT2_IOC32_SETFLAGS             FS_IOC32_SETFLAGS
 291#define EXT2_IOC32_GETVERSION           FS_IOC32_GETVERSION
 292#define EXT2_IOC32_SETVERSION           FS_IOC32_SETVERSION
 293
 294/*
 295 * Structure of an inode on the disk
 296 */
 297struct ext2_inode {
 298        __le16  i_mode;         /* File mode */
 299        __le16  i_uid;          /* Low 16 bits of Owner Uid */
 300        __le32  i_size;         /* Size in bytes */
 301        __le32  i_atime;        /* Access time */
 302        __le32  i_ctime;        /* Creation time */
 303        __le32  i_mtime;        /* Modification time */
 304        __le32  i_dtime;        /* Deletion Time */
 305        __le16  i_gid;          /* Low 16 bits of Group Id */
 306        __le16  i_links_count;  /* Links count */
 307        __le32  i_blocks;       /* Blocks count */
 308        __le32  i_flags;        /* File flags */
 309        union {
 310                struct {
 311                        __le32  l_i_reserved1;
 312                } linux1;
 313                struct {
 314                        __le32  h_i_translator;
 315                } hurd1;
 316                struct {
 317                        __le32  m_i_reserved1;
 318                } masix1;
 319        } osd1;                         /* OS dependent 1 */
 320        __le32  i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
 321        __le32  i_generation;   /* File version (for NFS) */
 322        __le32  i_file_acl;     /* File ACL */
 323        __le32  i_dir_acl;      /* Directory ACL */
 324        __le32  i_faddr;        /* Fragment address */
 325        union {
 326                struct {
 327                        __u8    l_i_frag;       /* Fragment number */
 328                        __u8    l_i_fsize;      /* Fragment size */
 329                        __u16   i_pad1;
 330                        __le16  l_i_uid_high;   /* these 2 fields    */
 331                        __le16  l_i_gid_high;   /* were reserved2[0] */
 332                        __u32   l_i_reserved2;
 333                } linux2;
 334                struct {
 335                        __u8    h_i_frag;       /* Fragment number */
 336                        __u8    h_i_fsize;      /* Fragment size */
 337                        __le16  h_i_mode_high;
 338                        __le16  h_i_uid_high;
 339                        __le16  h_i_gid_high;
 340                        __le32  h_i_author;
 341                } hurd2;
 342                struct {
 343                        __u8    m_i_frag;       /* Fragment number */
 344                        __u8    m_i_fsize;      /* Fragment size */
 345                        __u16   m_pad1;
 346                        __u32   m_i_reserved2[2];
 347                } masix2;
 348        } osd2;                         /* OS dependent 2 */
 349};
 350
 351#define i_size_high     i_dir_acl
 352
 353#define i_reserved1     osd1.linux1.l_i_reserved1
 354#define i_frag          osd2.linux2.l_i_frag
 355#define i_fsize         osd2.linux2.l_i_fsize
 356#define i_uid_low       i_uid
 357#define i_gid_low       i_gid
 358#define i_uid_high      osd2.linux2.l_i_uid_high
 359#define i_gid_high      osd2.linux2.l_i_gid_high
 360#define i_reserved2     osd2.linux2.l_i_reserved2
 361
 362/*
 363 * File system states
 364 */
 365#define EXT2_VALID_FS                   0x0001  /* Unmounted cleanly */
 366#define EXT2_ERROR_FS                   0x0002  /* Errors detected */
 367
 368/*
 369 * Mount flags
 370 */
 371#define EXT2_MOUNT_CHECK                0x000001  /* Do mount-time checks */
 372#define EXT2_MOUNT_OLDALLOC             0x000002  /* Don't use the new Orlov allocator */
 373#define EXT2_MOUNT_GRPID                0x000004  /* Create files with directory's group */
 374#define EXT2_MOUNT_DEBUG                0x000008  /* Some debugging messages */
 375#define EXT2_MOUNT_ERRORS_CONT          0x000010  /* Continue on errors */
 376#define EXT2_MOUNT_ERRORS_RO            0x000020  /* Remount fs ro on errors */
 377#define EXT2_MOUNT_ERRORS_PANIC         0x000040  /* Panic on errors */
 378#define EXT2_MOUNT_MINIX_DF             0x000080  /* Mimics the Minix statfs */
 379#define EXT2_MOUNT_NOBH                 0x000100  /* No buffer_heads */
 380#define EXT2_MOUNT_NO_UID32             0x000200  /* Disable 32-bit UIDs */
 381#define EXT2_MOUNT_XATTR_USER           0x004000  /* Extended user attributes */
 382#define EXT2_MOUNT_POSIX_ACL            0x008000  /* POSIX Access Control Lists */
 383#define EXT2_MOUNT_XIP                  0x010000  /* Execute in place */
 384#define EXT2_MOUNT_USRQUOTA             0x020000  /* user quota */
 385#define EXT2_MOUNT_GRPQUOTA             0x040000  /* group quota */
 386#define EXT2_MOUNT_RESERVATION          0x080000  /* Preallocation */
 387
 388
 389#define clear_opt(o, opt)               o &= ~EXT2_MOUNT_##opt
 390#define set_opt(o, opt)                 o |= EXT2_MOUNT_##opt
 391#define test_opt(sb, opt)               (EXT2_SB(sb)->s_mount_opt & \
 392                                         EXT2_MOUNT_##opt)
 393/*
 394 * Maximal mount counts between two filesystem checks
 395 */
 396#define EXT2_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
 397#define EXT2_DFL_CHECKINTERVAL          0       /* Don't use interval check */
 398
 399/*
 400 * Behaviour when detecting errors
 401 */
 402#define EXT2_ERRORS_CONTINUE            1       /* Continue execution */
 403#define EXT2_ERRORS_RO                  2       /* Remount fs read-only */
 404#define EXT2_ERRORS_PANIC               3       /* Panic */
 405#define EXT2_ERRORS_DEFAULT             EXT2_ERRORS_CONTINUE
 406
 407/*
 408 * Structure of the super block
 409 */
 410struct ext2_super_block {
 411        __le32  s_inodes_count;         /* Inodes count */
 412        __le32  s_blocks_count;         /* Blocks count */
 413        __le32  s_r_blocks_count;       /* Reserved blocks count */
 414        __le32  s_free_blocks_count;    /* Free blocks count */
 415        __le32  s_free_inodes_count;    /* Free inodes count */
 416        __le32  s_first_data_block;     /* First Data Block */
 417        __le32  s_log_block_size;       /* Block size */
 418        __le32  s_log_frag_size;        /* Fragment size */
 419        __le32  s_blocks_per_group;     /* # Blocks per group */
 420        __le32  s_frags_per_group;      /* # Fragments per group */
 421        __le32  s_inodes_per_group;     /* # Inodes per group */
 422        __le32  s_mtime;                /* Mount time */
 423        __le32  s_wtime;                /* Write time */
 424        __le16  s_mnt_count;            /* Mount count */
 425        __le16  s_max_mnt_count;        /* Maximal mount count */
 426        __le16  s_magic;                /* Magic signature */
 427        __le16  s_state;                /* File system state */
 428        __le16  s_errors;               /* Behaviour when detecting errors */
 429        __le16  s_minor_rev_level;      /* minor revision level */
 430        __le32  s_lastcheck;            /* time of last check */
 431        __le32  s_checkinterval;        /* max. time between checks */
 432        __le32  s_creator_os;           /* OS */
 433        __le32  s_rev_level;            /* Revision level */
 434        __le16  s_def_resuid;           /* Default uid for reserved blocks */
 435        __le16  s_def_resgid;           /* Default gid for reserved blocks */
 436        /*
 437         * These fields are for EXT2_DYNAMIC_REV superblocks only.
 438         *
 439         * Note: the difference between the compatible feature set and
 440         * the incompatible feature set is that if there is a bit set
 441         * in the incompatible feature set that the kernel doesn't
 442         * know about, it should refuse to mount the filesystem.
 443         * 
 444         * e2fsck's requirements are more strict; if it doesn't know
 445         * about a feature in either the compatible or incompatible
 446         * feature set, it must abort and not try to meddle with
 447         * things it doesn't understand...
 448         */
 449        __le32  s_first_ino;            /* First non-reserved inode */
 450        __le16   s_inode_size;          /* size of inode structure */
 451        __le16  s_block_group_nr;       /* block group # of this superblock */
 452        __le32  s_feature_compat;       /* compatible feature set */
 453        __le32  s_feature_incompat;     /* incompatible feature set */
 454        __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
 455        __u8    s_uuid[16];             /* 128-bit uuid for volume */
 456        char    s_volume_name[16];      /* volume name */
 457        char    s_last_mounted[64];     /* directory where last mounted */
 458        __le32  s_algorithm_usage_bitmap; /* For compression */
 459        /*
 460         * Performance hints.  Directory preallocation should only
 461         * happen if the EXT2_COMPAT_PREALLOC flag is on.
 462         */
 463        __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
 464        __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
 465        __u16   s_padding1;
 466        /*
 467         * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set.
 468         */
 469        __u8    s_journal_uuid[16];     /* uuid of journal superblock */
 470        __u32   s_journal_inum;         /* inode number of journal file */
 471        __u32   s_journal_dev;          /* device number of journal file */
 472        __u32   s_last_orphan;          /* start of list of inodes to delete */
 473        __u32   s_hash_seed[4];         /* HTREE hash seed */
 474        __u8    s_def_hash_version;     /* Default hash version to use */
 475        __u8    s_reserved_char_pad;
 476        __u16   s_reserved_word_pad;
 477        __le32  s_default_mount_opts;
 478        __le32  s_first_meta_bg;        /* First metablock block group */
 479        __u32   s_reserved[190];        /* Padding to the end of the block */
 480};
 481
 482/*
 483 * Codes for operating systems
 484 */
 485#define EXT2_OS_LINUX           0
 486#define EXT2_OS_HURD            1
 487#define EXT2_OS_MASIX           2
 488#define EXT2_OS_FREEBSD         3
 489#define EXT2_OS_LITES           4
 490
 491/*
 492 * Revision levels
 493 */
 494#define EXT2_GOOD_OLD_REV       0       /* The good old (original) format */
 495#define EXT2_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
 496
 497#define EXT2_CURRENT_REV        EXT2_GOOD_OLD_REV
 498#define EXT2_MAX_SUPP_REV       EXT2_DYNAMIC_REV
 499
 500#define EXT2_GOOD_OLD_INODE_SIZE 128
 501
 502/*
 503 * Feature set definitions
 504 */
 505
 506#define EXT2_HAS_COMPAT_FEATURE(sb,mask)                        \
 507        ( EXT2_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) )
 508#define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
 509        ( EXT2_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) )
 510#define EXT2_HAS_INCOMPAT_FEATURE(sb,mask)                      \
 511        ( EXT2_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) )
 512#define EXT2_SET_COMPAT_FEATURE(sb,mask)                        \
 513        EXT2_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
 514#define EXT2_SET_RO_COMPAT_FEATURE(sb,mask)                     \
 515        EXT2_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
 516#define EXT2_SET_INCOMPAT_FEATURE(sb,mask)                      \
 517        EXT2_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
 518#define EXT2_CLEAR_COMPAT_FEATURE(sb,mask)                      \
 519        EXT2_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
 520#define EXT2_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
 521        EXT2_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
 522#define EXT2_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
 523        EXT2_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
 524
 525#define EXT2_FEATURE_COMPAT_DIR_PREALLOC        0x0001
 526#define EXT2_FEATURE_COMPAT_IMAGIC_INODES       0x0002
 527#define EXT3_FEATURE_COMPAT_HAS_JOURNAL         0x0004
 528#define EXT2_FEATURE_COMPAT_EXT_ATTR            0x0008
 529#define EXT2_FEATURE_COMPAT_RESIZE_INO          0x0010
 530#define EXT2_FEATURE_COMPAT_DIR_INDEX           0x0020
 531#define EXT2_FEATURE_COMPAT_ANY                 0xffffffff
 532
 533#define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
 534#define EXT2_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
 535#define EXT2_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
 536#define EXT2_FEATURE_RO_COMPAT_ANY              0xffffffff
 537
 538#define EXT2_FEATURE_INCOMPAT_COMPRESSION       0x0001
 539#define EXT2_FEATURE_INCOMPAT_FILETYPE          0x0002
 540#define EXT3_FEATURE_INCOMPAT_RECOVER           0x0004
 541#define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008
 542#define EXT2_FEATURE_INCOMPAT_META_BG           0x0010
 543#define EXT2_FEATURE_INCOMPAT_ANY               0xffffffff
 544
 545#define EXT2_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
 546#define EXT2_FEATURE_INCOMPAT_SUPP      (EXT2_FEATURE_INCOMPAT_FILETYPE| \
 547                                         EXT2_FEATURE_INCOMPAT_META_BG)
 548#define EXT2_FEATURE_RO_COMPAT_SUPP     (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
 549                                         EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
 550                                         EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
 551#define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED      ~EXT2_FEATURE_RO_COMPAT_SUPP
 552#define EXT2_FEATURE_INCOMPAT_UNSUPPORTED       ~EXT2_FEATURE_INCOMPAT_SUPP
 553
 554/*
 555 * Default values for user and/or group using reserved blocks
 556 */
 557#define EXT2_DEF_RESUID         0
 558#define EXT2_DEF_RESGID         0
 559
 560/*
 561 * Default mount options
 562 */
 563#define EXT2_DEFM_DEBUG         0x0001
 564#define EXT2_DEFM_BSDGROUPS     0x0002
 565#define EXT2_DEFM_XATTR_USER    0x0004
 566#define EXT2_DEFM_ACL           0x0008
 567#define EXT2_DEFM_UID16         0x0010
 568    /* Not used by ext2, but reserved for use by ext3 */
 569#define EXT3_DEFM_JMODE         0x0060 
 570#define EXT3_DEFM_JMODE_DATA    0x0020
 571#define EXT3_DEFM_JMODE_ORDERED 0x0040
 572#define EXT3_DEFM_JMODE_WBACK   0x0060
 573
 574/*
 575 * Structure of a directory entry
 576 */
 577
 578struct ext2_dir_entry {
 579        __le32  inode;                  /* Inode number */
 580        __le16  rec_len;                /* Directory entry length */
 581        __le16  name_len;               /* Name length */
 582        char    name[];                 /* File name, up to EXT2_NAME_LEN */
 583};
 584
 585/*
 586 * The new version of the directory entry.  Since EXT2 structures are
 587 * stored in intel byte order, and the name_len field could never be
 588 * bigger than 255 chars, it's safe to reclaim the extra byte for the
 589 * file_type field.
 590 */
 591struct ext2_dir_entry_2 {
 592        __le32  inode;                  /* Inode number */
 593        __le16  rec_len;                /* Directory entry length */
 594        __u8    name_len;               /* Name length */
 595        __u8    file_type;
 596        char    name[];                 /* File name, up to EXT2_NAME_LEN */
 597};
 598
 599/*
 600 * Ext2 directory file types.  Only the low 3 bits are used.  The
 601 * other bits are reserved for now.
 602 */
 603enum {
 604        EXT2_FT_UNKNOWN         = 0,
 605        EXT2_FT_REG_FILE        = 1,
 606        EXT2_FT_DIR             = 2,
 607        EXT2_FT_CHRDEV          = 3,
 608        EXT2_FT_BLKDEV          = 4,
 609        EXT2_FT_FIFO            = 5,
 610        EXT2_FT_SOCK            = 6,
 611        EXT2_FT_SYMLINK         = 7,
 612        EXT2_FT_MAX
 613};
 614
 615/*
 616 * EXT2_DIR_PAD defines the directory entries boundaries
 617 *
 618 * NOTE: It must be a multiple of 4
 619 */
 620#define EXT2_DIR_PAD                    4
 621#define EXT2_DIR_ROUND                  (EXT2_DIR_PAD - 1)
 622#define EXT2_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT2_DIR_ROUND) & \
 623                                         ~EXT2_DIR_ROUND)
 624#define EXT2_MAX_REC_LEN                ((1<<16)-1)
 625
 626static inline void verify_offsets(void)
 627{
 628#define A(x,y) BUILD_BUG_ON(x != offsetof(struct ext2_super_block, y));
 629        A(EXT2_SB_MAGIC_OFFSET, s_magic);
 630        A(EXT2_SB_BLOCKS_OFFSET, s_blocks_count);
 631        A(EXT2_SB_BSIZE_OFFSET, s_log_block_size);
 632#undef A
 633}
 634
 635/*
 636 * ext2 mount options
 637 */
 638struct ext2_mount_options {
 639        unsigned long s_mount_opt;
 640        kuid_t s_resuid;
 641        kgid_t s_resgid;
 642};
 643
 644/*
 645 * second extended file system inode data in memory
 646 */
 647struct ext2_inode_info {
 648        __le32  i_data[15];
 649        __u32   i_flags;
 650        __u32   i_faddr;
 651        __u8    i_frag_no;
 652        __u8    i_frag_size;
 653        __u16   i_state;
 654        __u32   i_file_acl;
 655        __u32   i_dir_acl;
 656        __u32   i_dtime;
 657
 658        /*
 659         * i_block_group is the number of the block group which contains
 660         * this file's inode.  Constant across the lifetime of the inode,
 661         * it is used for making block allocation decisions - we try to
 662         * place a file's data blocks near its inode block, and new inodes
 663         * near to their parent directory's inode.
 664         */
 665        __u32   i_block_group;
 666
 667        /* block reservation info */
 668        struct ext2_block_alloc_info *i_block_alloc_info;
 669
 670        __u32   i_dir_start_lookup;
 671#ifdef CONFIG_EXT2_FS_XATTR
 672        /*
 673         * Extended attributes can be read independently of the main file
 674         * data. Taking i_mutex even when reading would cause contention
 675         * between readers of EAs and writers of regular file data, so
 676         * instead we synchronize on xattr_sem when reading or changing
 677         * EAs.
 678         */
 679        struct rw_semaphore xattr_sem;
 680#endif
 681        rwlock_t i_meta_lock;
 682
 683        /*
 684         * truncate_mutex is for serialising ext2_truncate() against
 685         * ext2_getblock().  It also protects the internals of the inode's
 686         * reservation data structures: ext2_reserve_window and
 687         * ext2_reserve_window_node.
 688         */
 689        struct mutex truncate_mutex;
 690        struct inode    vfs_inode;
 691        struct list_head i_orphan;      /* unlinked but open inodes */
 692};
 693
 694/*
 695 * Inode dynamic state flags
 696 */
 697#define EXT2_STATE_NEW                  0x00000001 /* inode is newly created */
 698
 699
 700/*
 701 * Function prototypes
 702 */
 703
 704/*
 705 * Ok, these declarations are also in <linux/kernel.h> but none of the
 706 * ext2 source programs needs to include it so they are duplicated here.
 707 */
 708
 709static inline struct ext2_inode_info *EXT2_I(struct inode *inode)
 710{
 711        return container_of(inode, struct ext2_inode_info, vfs_inode);
 712}
 713
 714/* balloc.c */
 715extern int ext2_bg_has_super(struct super_block *sb, int group);
 716extern unsigned long ext2_bg_num_gdb(struct super_block *sb, int group);
 717extern ext2_fsblk_t ext2_new_block(struct inode *, unsigned long, int *);
 718extern ext2_fsblk_t ext2_new_blocks(struct inode *, unsigned long,
 719                                unsigned long *, int *);
 720extern void ext2_free_blocks (struct inode *, unsigned long,
 721                              unsigned long);
 722extern unsigned long ext2_count_free_blocks (struct super_block *);
 723extern unsigned long ext2_count_dirs (struct super_block *);
 724extern void ext2_check_blocks_bitmap (struct super_block *);
 725extern struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb,
 726                                                    unsigned int block_group,
 727                                                    struct buffer_head ** bh);
 728extern void ext2_discard_reservation (struct inode *);
 729extern int ext2_should_retry_alloc(struct super_block *sb, int *retries);
 730extern void ext2_init_block_alloc_info(struct inode *);
 731extern void ext2_rsv_window_add(struct super_block *sb, struct ext2_reserve_window_node *rsv);
 732
 733/* dir.c */
 734extern int ext2_add_link (struct dentry *, struct inode *);
 735extern ino_t ext2_inode_by_name(struct inode *, struct qstr *);
 736extern int ext2_make_empty(struct inode *, struct inode *);
 737extern struct ext2_dir_entry_2 * ext2_find_entry (struct inode *,struct qstr *, struct page **);
 738extern int ext2_delete_entry (struct ext2_dir_entry_2 *, struct page *);
 739extern int ext2_empty_dir (struct inode *);
 740extern struct ext2_dir_entry_2 * ext2_dotdot (struct inode *, struct page **);
 741extern void ext2_set_link(struct inode *, struct ext2_dir_entry_2 *, struct page *, struct inode *, int);
 742
 743/* ialloc.c */
 744extern struct inode * ext2_new_inode (struct inode *, umode_t, const struct qstr *);
 745extern void ext2_free_inode (struct inode *);
 746extern unsigned long ext2_count_free_inodes (struct super_block *);
 747extern void ext2_check_inodes_bitmap (struct super_block *);
 748extern unsigned long ext2_count_free (struct buffer_head *, unsigned);
 749
 750/* inode.c */
 751extern struct inode *ext2_iget (struct super_block *, unsigned long);
 752extern int ext2_write_inode (struct inode *, struct writeback_control *);
 753extern void ext2_evict_inode(struct inode *);
 754extern int ext2_get_block(struct inode *, sector_t, struct buffer_head *, int);
 755extern int ext2_setattr (struct dentry *, struct iattr *);
 756extern void ext2_set_inode_flags(struct inode *inode);
 757extern void ext2_get_inode_flags(struct ext2_inode_info *);
 758extern int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 759                       u64 start, u64 len);
 760
 761/* ioctl.c */
 762extern long ext2_ioctl(struct file *, unsigned int, unsigned long);
 763extern long ext2_compat_ioctl(struct file *, unsigned int, unsigned long);
 764
 765/* namei.c */
 766struct dentry *ext2_get_parent(struct dentry *child);
 767
 768/* super.c */
 769extern __printf(3, 4)
 770void ext2_error(struct super_block *, const char *, const char *, ...);
 771extern __printf(3, 4)
 772void ext2_msg(struct super_block *, const char *, const char *, ...);
 773extern void ext2_update_dynamic_rev (struct super_block *sb);
 774extern void ext2_write_super (struct super_block *);
 775
 776/*
 777 * Inodes and files operations
 778 */
 779
 780/* dir.c */
 781extern const struct file_operations ext2_dir_operations;
 782
 783/* file.c */
 784extern int ext2_fsync(struct file *file, loff_t start, loff_t end,
 785                      int datasync);
 786extern const struct inode_operations ext2_file_inode_operations;
 787extern const struct file_operations ext2_file_operations;
 788extern const struct file_operations ext2_xip_file_operations;
 789
 790/* inode.c */
 791extern const struct address_space_operations ext2_aops;
 792extern const struct address_space_operations ext2_aops_xip;
 793extern const struct address_space_operations ext2_nobh_aops;
 794
 795/* namei.c */
 796extern const struct inode_operations ext2_dir_inode_operations;
 797extern const struct inode_operations ext2_special_inode_operations;
 798
 799/* symlink.c */
 800extern const struct inode_operations ext2_fast_symlink_inode_operations;
 801extern const struct inode_operations ext2_symlink_inode_operations;
 802
 803static inline ext2_fsblk_t
 804ext2_group_first_block_no(struct super_block *sb, unsigned long group_no)
 805{
 806        return group_no * (ext2_fsblk_t)EXT2_BLOCKS_PER_GROUP(sb) +
 807                le32_to_cpu(EXT2_SB(sb)->s_es->s_first_data_block);
 808}
 809
 810#define ext2_set_bit    __test_and_set_bit_le
 811#define ext2_clear_bit  __test_and_clear_bit_le
 812#define ext2_test_bit   test_bit_le
 813#define ext2_find_first_zero_bit        find_first_zero_bit_le
 814#define ext2_find_next_zero_bit         find_next_zero_bit_le
 815
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