LXR linux/fs/ext2/ext2.h

   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
  64struct mb_cache;
  65
  66/*
  67 * second extended-fs super-block data in memory
  68 */
  69struct ext2_sb_info {
  70        unsigned long s_frag_size;      /* Size of a fragment in bytes */
  71        unsigned long s_frags_per_block;/* Number of fragments per block */
  72        unsigned long s_inodes_per_block;/* Number of inodes per block */
  73        unsigned long s_frags_per_group;/* Number of fragments in a group */
  74        unsigned long s_blocks_per_group;/* Number of blocks in a group */
  75        unsigned long s_inodes_per_group;/* Number of inodes in a group */
  76        unsigned long s_itb_per_group;  /* Number of inode table blocks per group */
  77        unsigned long s_gdb_count;      /* Number of group descriptor blocks */
  78        unsigned long s_desc_per_block; /* Number of group descriptors per block */
  79        unsigned long s_groups_count;   /* Number of groups in the fs */
  80        unsigned long s_overhead_last;  /* Last calculated overhead */
  81        unsigned long s_blocks_last;    /* Last seen block count */
  82        struct buffer_head * s_sbh;     /* Buffer containing the super block */
  83        struct ext2_super_block * s_es; /* Pointer to the super block in the buffer */
  84        struct buffer_head ** s_group_desc;
  85        unsigned long  s_mount_opt;
  86        unsigned long s_sb_block;
  87        kuid_t s_resuid;
  88        kgid_t s_resgid;
  89        unsigned short s_mount_state;
  90        unsigned short s_pad;
  91        int s_addr_per_block_bits;
  92        int s_desc_per_block_bits;
  93        int s_inode_size;
  94        int s_first_ino;
  95        spinlock_t s_next_gen_lock;
  96        u32 s_next_generation;
  97        unsigned long s_dir_count;
  98        u8 *s_debts;
  99        struct percpu_counter s_freeblocks_counter;
 100        struct percpu_counter s_freeinodes_counter;
 101        struct percpu_counter s_dirs_counter;
 102        struct blockgroup_lock *s_blockgroup_lock;
 103        /* root of the per fs reservation window tree */
 104        spinlock_t s_rsv_window_lock;
 105        struct rb_root s_rsv_window_root;
 106        struct ext2_reserve_window_node s_rsv_window_head;
 107        /*
 108         * s_lock protects against concurrent modifications of s_mount_state,
 109         * s_blocks_last, s_overhead_last and the content of superblock's
 110         * buffer pointed to by sbi->s_es.
 111         *
 112         * Note: It is used in ext2_show_options() to provide a consistent view
 113         * of the mount options.
 114         */
 115        spinlock_t s_lock;
 116        struct mb_cache *s_mb_cache;
 117};
 118
 119static inline spinlock_t *
 120sb_bgl_lock(struct ext2_sb_info *sbi, unsigned int block_group)
 121{
 122        return bgl_lock_ptr(sbi->s_blockgroup_lock, block_group);
 123}
 124
 125/*
 126 * Define EXT2FS_DEBUG to produce debug messages
 127 */
 128#undef EXT2FS_DEBUG
 129
 130/*
 131 * Define EXT2_RESERVATION to reserve data blocks for expanding files
 132 */
 133#define EXT2_DEFAULT_RESERVE_BLOCKS     8
 134/*max window size: 1024(direct blocks) + 3([t,d]indirect blocks) */
 135#define EXT2_MAX_RESERVE_BLOCKS         1027
 136#define EXT2_RESERVE_WINDOW_NOT_ALLOCATED 0
 137/*
 138 * The second extended file system version
 139 */
 140#define EXT2FS_DATE             "95/08/09"
 141#define EXT2FS_VERSION          "0.5b"
 142
 143/*
 144 * Debug code
 145 */
 146#ifdef EXT2FS_DEBUG
 147#       define ext2_debug(f, a...)      { \
 148                                        printk ("EXT2-fs DEBUG (%s, %d): %s:", \
 149                                                __FILE__, __LINE__, __func__); \
 150                                        printk (f, ## a); \
 151                                        }
 152#else
 153#       define ext2_debug(f, a...)      /**/
 154#endif
 155
 156/*
 157 * Special inode numbers
 158 */
 159#define EXT2_BAD_INO             1      /* Bad blocks inode */
 160#define EXT2_ROOT_INO            2      /* Root inode */
 161#define EXT2_BOOT_LOADER_INO     5      /* Boot loader inode */
 162#define EXT2_UNDEL_DIR_INO       6      /* Undelete directory inode */
 163
 164/* First non-reserved inode for old ext2 filesystems */
 165#define EXT2_GOOD_OLD_FIRST_INO 11
 166
 167static inline struct ext2_sb_info *EXT2_SB(struct super_block *sb)
 168{
 169        return sb->s_fs_info;
 170}
 171
 172/*
 173 * Macro-instructions used to manage several block sizes
 174 */
 175#define EXT2_MIN_BLOCK_SIZE             1024
 176#define EXT2_MAX_BLOCK_SIZE             4096
 177#define EXT2_MIN_BLOCK_LOG_SIZE           10
 178#define EXT2_BLOCK_SIZE(s)              ((s)->s_blocksize)
 179#define EXT2_ADDR_PER_BLOCK(s)          (EXT2_BLOCK_SIZE(s) / sizeof (__u32))
 180#define EXT2_BLOCK_SIZE_BITS(s)         ((s)->s_blocksize_bits)
 181#define EXT2_ADDR_PER_BLOCK_BITS(s)     (EXT2_SB(s)->s_addr_per_block_bits)
 182#define EXT2_INODE_SIZE(s)              (EXT2_SB(s)->s_inode_size)
 183#define EXT2_FIRST_INO(s)               (EXT2_SB(s)->s_first_ino)
 184
 185/*
 186 * Macro-instructions used to manage fragments
 187 */
 188#define EXT2_MIN_FRAG_SIZE              1024
 189#define EXT2_MAX_FRAG_SIZE              4096
 190#define EXT2_MIN_FRAG_LOG_SIZE            10
 191#define EXT2_FRAG_SIZE(s)               (EXT2_SB(s)->s_frag_size)
 192#define EXT2_FRAGS_PER_BLOCK(s)         (EXT2_SB(s)->s_frags_per_block)
 193
 194/*
 195 * Structure of a blocks group descriptor
 196 */
 197struct ext2_group_desc
 198{
 199        __le32  bg_block_bitmap;                /* Blocks bitmap block */
 200        __le32  bg_inode_bitmap;                /* Inodes bitmap block */
 201        __le32  bg_inode_table;         /* Inodes table block */
 202        __le16  bg_free_blocks_count;   /* Free blocks count */
 203        __le16  bg_free_inodes_count;   /* Free inodes count */
 204        __le16  bg_used_dirs_count;     /* Directories count */
 205        __le16  bg_pad;
 206        __le32  bg_reserved[3];
 207};
 208
 209/*
 210 * Macro-instructions used to manage group descriptors
 211 */
 212#define EXT2_BLOCKS_PER_GROUP(s)        (EXT2_SB(s)->s_blocks_per_group)
 213#define EXT2_DESC_PER_BLOCK(s)          (EXT2_SB(s)->s_desc_per_block)
 214#define EXT2_INODES_PER_GROUP(s)        (EXT2_SB(s)->s_inodes_per_group)
 215#define EXT2_DESC_PER_BLOCK_BITS(s)     (EXT2_SB(s)->s_desc_per_block_bits)
 216
 217/*
 218 * Constants relative to the data blocks
 219 */
 220#define EXT2_NDIR_BLOCKS                12
 221#define EXT2_IND_BLOCK                  EXT2_NDIR_BLOCKS
 222#define EXT2_DIND_BLOCK                 (EXT2_IND_BLOCK + 1)
 223#define EXT2_TIND_BLOCK                 (EXT2_DIND_BLOCK + 1)
 224#define EXT2_N_BLOCKS                   (EXT2_TIND_BLOCK + 1)
 225
 226/*
 227 * Inode flags (GETFLAGS/SETFLAGS)
 228 */
 229#define EXT2_SECRM_FL                   FS_SECRM_FL     /* Secure deletion */
 230#define EXT2_UNRM_FL                    FS_UNRM_FL      /* Undelete */
 231#define EXT2_COMPR_FL                   FS_COMPR_FL     /* Compress file */
 232#define EXT2_SYNC_FL                    FS_SYNC_FL      /* Synchronous updates */
 233#define EXT2_IMMUTABLE_FL               FS_IMMUTABLE_FL /* Immutable file */
 234#define EXT2_APPEND_FL                  FS_APPEND_FL    /* writes to file may only append */
 235#define EXT2_NODUMP_FL                  FS_NODUMP_FL    /* do not dump file */
 236#define EXT2_NOATIME_FL                 FS_NOATIME_FL   /* do not update atime */
 237/* Reserved for compression usage... */
 238#define EXT2_DIRTY_FL                   FS_DIRTY_FL
 239#define EXT2_COMPRBLK_FL                FS_COMPRBLK_FL  /* One or more compressed clusters */
 240#define EXT2_NOCOMP_FL                  FS_NOCOMP_FL    /* Don't compress */
 241#define EXT2_ECOMPR_FL                  FS_ECOMPR_FL    /* Compression error */
 242/* End compression flags --- maybe not all used */      
 243#define EXT2_BTREE_FL                   FS_BTREE_FL     /* btree format dir */
 244#define EXT2_INDEX_FL                   FS_INDEX_FL     /* hash-indexed directory */
 245#define EXT2_IMAGIC_FL                  FS_IMAGIC_FL    /* AFS directory */
 246#define EXT2_JOURNAL_DATA_FL            FS_JOURNAL_DATA_FL /* Reserved for ext3 */
 247#define EXT2_NOTAIL_FL                  FS_NOTAIL_FL    /* file tail should not be merged */
 248#define EXT2_DIRSYNC_FL                 FS_DIRSYNC_FL   /* dirsync behaviour (directories only) */
 249#define EXT2_TOPDIR_FL                  FS_TOPDIR_FL    /* Top of directory hierarchies*/
 250#define EXT2_RESERVED_FL                FS_RESERVED_FL  /* reserved for ext2 lib */
 251
 252#define EXT2_FL_USER_VISIBLE            FS_FL_USER_VISIBLE      /* User visible flags */
 253#define EXT2_FL_USER_MODIFIABLE         FS_FL_USER_MODIFIABLE   /* User modifiable flags */
 254
 255/* Flags that should be inherited by new inodes from their parent. */
 256#define EXT2_FL_INHERITED (EXT2_SECRM_FL | EXT2_UNRM_FL | EXT2_COMPR_FL |\
 257                           EXT2_SYNC_FL | EXT2_NODUMP_FL |\
 258                           EXT2_NOATIME_FL | EXT2_COMPRBLK_FL |\
 259                           EXT2_NOCOMP_FL | EXT2_JOURNAL_DATA_FL |\
 260                           EXT2_NOTAIL_FL | EXT2_DIRSYNC_FL)
 261
 262/* Flags that are appropriate for regular files (all but dir-specific ones). */
 263#define EXT2_REG_FLMASK (~(EXT2_DIRSYNC_FL | EXT2_TOPDIR_FL))
 264
 265/* Flags that are appropriate for non-directories/regular files. */
 266#define EXT2_OTHER_FLMASK (EXT2_NODUMP_FL | EXT2_NOATIME_FL)
 267
 268/* Mask out flags that are inappropriate for the given type of inode. */
 269static inline __u32 ext2_mask_flags(umode_t mode, __u32 flags)
 270{
 271        if (S_ISDIR(mode))
 272                return flags;
 273        else if (S_ISREG(mode))
 274                return flags & EXT2_REG_FLMASK;
 275        else
 276                return flags & EXT2_OTHER_FLMASK;
 277}
 278
 279/*
 280 * ioctl commands
 281 */
 282#define EXT2_IOC_GETFLAGS               FS_IOC_GETFLAGS
 283#define EXT2_IOC_SETFLAGS               FS_IOC_SETFLAGS
 284#define EXT2_IOC_GETVERSION             FS_IOC_GETVERSION
 285#define EXT2_IOC_SETVERSION             FS_IOC_SETVERSION
 286#define EXT2_IOC_GETRSVSZ               _IOR('f', 5, long)
 287#define EXT2_IOC_SETRSVSZ               _IOW('f', 6, long)
 288
 289/*
 290 * ioctl commands in 32 bit emulation
 291 */
 292#define EXT2_IOC32_GETFLAGS             FS_IOC32_GETFLAGS
 293#define EXT2_IOC32_SETFLAGS             FS_IOC32_SETFLAGS
 294#define EXT2_IOC32_GETVERSION           FS_IOC32_GETVERSION
 295#define EXT2_IOC32_SETVERSION           FS_IOC32_SETVERSION
 296
 297/*
 298 * Structure of an inode on the disk
 299 */
 300struct ext2_inode {
 301        __le16  i_mode;         /* File mode */
 302        __le16  i_uid;          /* Low 16 bits of Owner Uid */
 303        __le32  i_size;         /* Size in bytes */
 304        __le32  i_atime;        /* Access time */
 305        __le32  i_ctime;        /* Creation time */
 306        __le32  i_mtime;        /* Modification time */
 307        __le32  i_dtime;        /* Deletion Time */
 308        __le16  i_gid;          /* Low 16 bits of Group Id */
 309        __le16  i_links_count;  /* Links count */
 310        __le32  i_blocks;       /* Blocks count */
 311        __le32  i_flags;        /* File flags */
 312        union {
 313                struct {
 314                        __le32  l_i_reserved1;
 315                } linux1;
 316                struct {
 317                        __le32  h_i_translator;
 318                } hurd1;
 319                struct {
 320                        __le32  m_i_reserved1;
 321                } masix1;
 322        } osd1;                         /* OS dependent 1 */
 323        __le32  i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
 324        __le32  i_generation;   /* File version (for NFS) */
 325        __le32  i_file_acl;     /* File ACL */
 326        __le32  i_dir_acl;      /* Directory ACL */
 327        __le32  i_faddr;        /* Fragment address */
 328        union {
 329                struct {
 330                        __u8    l_i_frag;       /* Fragment number */
 331                        __u8    l_i_fsize;      /* Fragment size */
 332                        __u16   i_pad1;
 333                        __le16  l_i_uid_high;   /* these 2 fields    */
 334                        __le16  l_i_gid_high;   /* were reserved2[0] */
 335                        __u32   l_i_reserved2;
 336                } linux2;
 337                struct {
 338                        __u8    h_i_frag;       /* Fragment number */
 339                        __u8    h_i_fsize;      /* Fragment size */
 340                        __le16  h_i_mode_high;
 341                        __le16  h_i_uid_high;
 342                        __le16  h_i_gid_high;
 343                        __le32  h_i_author;
 344                } hurd2;
 345                struct {
 346                        __u8    m_i_frag;       /* Fragment number */
 347                        __u8    m_i_fsize;      /* Fragment size */
 348                        __u16   m_pad1;
 349                        __u32   m_i_reserved2[2];
 350                } masix2;
 351        } osd2;                         /* OS dependent 2 */
 352};
 353
 354#define i_size_high     i_dir_acl
 355
 356#define i_reserved1     osd1.linux1.l_i_reserved1
 357#define i_frag          osd2.linux2.l_i_frag
 358#define i_fsize         osd2.linux2.l_i_fsize
 359#define i_uid_low       i_uid
 360#define i_gid_low       i_gid
 361#define i_uid_high      osd2.linux2.l_i_uid_high
 362#define i_gid_high      osd2.linux2.l_i_gid_high
 363#define i_reserved2     osd2.linux2.l_i_reserved2
 364
 365/*
 366 * File system states
 367 */
 368#define EXT2_VALID_FS                   0x0001  /* Unmounted cleanly */
 369#define EXT2_ERROR_FS                   0x0002  /* Errors detected */
 370#define EFSCORRUPTED                    EUCLEAN /* Filesystem is corrupted */
 371
 372/*
 373 * Mount flags
 374 */
 375#define EXT2_MOUNT_CHECK                0x000001  /* Do mount-time checks */
 376#define EXT2_MOUNT_OLDALLOC             0x000002  /* Don't use the new Orlov allocator */
 377#define EXT2_MOUNT_GRPID                0x000004  /* Create files with directory's group */
 378#define EXT2_MOUNT_DEBUG                0x000008  /* Some debugging messages */
 379#define EXT2_MOUNT_ERRORS_CONT          0x000010  /* Continue on errors */
 380#define EXT2_MOUNT_ERRORS_RO            0x000020  /* Remount fs ro on errors */
 381#define EXT2_MOUNT_ERRORS_PANIC         0x000040  /* Panic on errors */
 382#define EXT2_MOUNT_MINIX_DF             0x000080  /* Mimics the Minix statfs */
 383#define EXT2_MOUNT_NOBH                 0x000100  /* No buffer_heads */
 384#define EXT2_MOUNT_NO_UID32             0x000200  /* Disable 32-bit UIDs */
 385#define EXT2_MOUNT_XATTR_USER           0x004000  /* Extended user attributes */
 386#define EXT2_MOUNT_POSIX_ACL            0x008000  /* POSIX Access Control Lists */
 387#define EXT2_MOUNT_XIP                  0x010000  /* Obsolete, use DAX */
 388#define EXT2_MOUNT_USRQUOTA             0x020000  /* user quota */
 389#define EXT2_MOUNT_GRPQUOTA             0x040000  /* group quota */
 390#define EXT2_MOUNT_RESERVATION          0x080000  /* Preallocation */
 391#ifdef CONFIG_FS_DAX
 392#define EXT2_MOUNT_DAX                  0x100000  /* Direct Access */
 393#else
 394#define EXT2_MOUNT_DAX                  0
 395#endif
 396
 397
 398#define clear_opt(o, opt)               o &= ~EXT2_MOUNT_##opt
 399#define set_opt(o, opt)                 o |= EXT2_MOUNT_##opt
 400#define test_opt(sb, opt)               (EXT2_SB(sb)->s_mount_opt & \
 401                                         EXT2_MOUNT_##opt)
 402/*
 403 * Maximal mount counts between two filesystem checks
 404 */
 405#define EXT2_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
 406#define EXT2_DFL_CHECKINTERVAL          0       /* Don't use interval check */
 407
 408/*
 409 * Behaviour when detecting errors
 410 */
 411#define EXT2_ERRORS_CONTINUE            1       /* Continue execution */
 412#define EXT2_ERRORS_RO                  2       /* Remount fs read-only */
 413#define EXT2_ERRORS_PANIC               3       /* Panic */
 414#define EXT2_ERRORS_DEFAULT             EXT2_ERRORS_CONTINUE
 415
 416/*
 417 * Structure of the super block
 418 */
 419struct ext2_super_block {
 420        __le32  s_inodes_count;         /* Inodes count */
 421        __le32  s_blocks_count;         /* Blocks count */
 422        __le32  s_r_blocks_count;       /* Reserved blocks count */
 423        __le32  s_free_blocks_count;    /* Free blocks count */
 424        __le32  s_free_inodes_count;    /* Free inodes count */
 425        __le32  s_first_data_block;     /* First Data Block */
 426        __le32  s_log_block_size;       /* Block size */
 427        __le32  s_log_frag_size;        /* Fragment size */
 428        __le32  s_blocks_per_group;     /* # Blocks per group */
 429        __le32  s_frags_per_group;      /* # Fragments per group */
 430        __le32  s_inodes_per_group;     /* # Inodes per group */
 431        __le32  s_mtime;                /* Mount time */
 432        __le32  s_wtime;                /* Write time */
 433        __le16  s_mnt_count;            /* Mount count */
 434        __le16  s_max_mnt_count;        /* Maximal mount count */
 435        __le16  s_magic;                /* Magic signature */
 436        __le16  s_state;                /* File system state */
 437        __le16  s_errors;               /* Behaviour when detecting errors */
 438        __le16  s_minor_rev_level;      /* minor revision level */
 439        __le32  s_lastcheck;            /* time of last check */
 440        __le32  s_checkinterval;        /* max. time between checks */
 441        __le32  s_creator_os;           /* OS */
 442        __le32  s_rev_level;            /* Revision level */
 443        __le16  s_def_resuid;           /* Default uid for reserved blocks */
 444        __le16  s_def_resgid;           /* Default gid for reserved blocks */
 445        /*
 446         * These fields are for EXT2_DYNAMIC_REV superblocks only.
 447         *
 448         * Note: the difference between the compatible feature set and
 449         * the incompatible feature set is that if there is a bit set
 450         * in the incompatible feature set that the kernel doesn't
 451         * know about, it should refuse to mount the filesystem.
 452         * 
 453         * e2fsck's requirements are more strict; if it doesn't know
 454         * about a feature in either the compatible or incompatible
 455         * feature set, it must abort and not try to meddle with
 456         * things it doesn't understand...
 457         */
 458        __le32  s_first_ino;            /* First non-reserved inode */
 459        __le16   s_inode_size;          /* size of inode structure */
 460        __le16  s_block_group_nr;       /* block group # of this superblock */
 461        __le32  s_feature_compat;       /* compatible feature set */
 462        __le32  s_feature_incompat;     /* incompatible feature set */
 463        __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
 464        __u8    s_uuid[16];             /* 128-bit uuid for volume */
 465        char    s_volume_name[16];      /* volume name */
 466        char    s_last_mounted[64];     /* directory where last mounted */
 467        __le32  s_algorithm_usage_bitmap; /* For compression */
 468        /*
 469         * Performance hints.  Directory preallocation should only
 470         * happen if the EXT2_COMPAT_PREALLOC flag is on.
 471         */
 472        __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
 473        __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
 474        __u16   s_padding1;
 475        /*
 476         * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set.
 477         */
 478        __u8    s_journal_uuid[16];     /* uuid of journal superblock */
 479        __u32   s_journal_inum;         /* inode number of journal file */
 480        __u32   s_journal_dev;          /* device number of journal file */
 481        __u32   s_last_orphan;          /* start of list of inodes to delete */
 482        __u32   s_hash_seed[4];         /* HTREE hash seed */
 483        __u8    s_def_hash_version;     /* Default hash version to use */
 484        __u8    s_reserved_char_pad;
 485        __u16   s_reserved_word_pad;
 486        __le32  s_default_mount_opts;
 487        __le32  s_first_meta_bg;        /* First metablock block group */
 488        __u32   s_reserved[190];        /* Padding to the end of the block */
 489};
 490
 491/*
 492 * Codes for operating systems
 493 */
 494#define EXT2_OS_LINUX           0
 495#define EXT2_OS_HURD            1
 496#define EXT2_OS_MASIX           2
 497#define EXT2_OS_FREEBSD         3
 498#define EXT2_OS_LITES           4
 499
 500/*
 501 * Revision levels
 502 */
 503#define EXT2_GOOD_OLD_REV       0       /* The good old (original) format */
 504#define EXT2_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
 505
 506#define EXT2_CURRENT_REV        EXT2_GOOD_OLD_REV
 507#define EXT2_MAX_SUPP_REV       EXT2_DYNAMIC_REV
 508
 509#define EXT2_GOOD_OLD_INODE_SIZE 128
 510
 511/*
 512 * Feature set definitions
 513 */
 514
 515#define EXT2_HAS_COMPAT_FEATURE(sb,mask)                        \
 516        ( EXT2_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) )
 517#define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
 518        ( EXT2_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) )
 519#define EXT2_HAS_INCOMPAT_FEATURE(sb,mask)                      \
 520        ( EXT2_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) )
 521#define EXT2_SET_COMPAT_FEATURE(sb,mask)                        \
 522        EXT2_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
 523#define EXT2_SET_RO_COMPAT_FEATURE(sb,mask)                     \
 524        EXT2_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
 525#define EXT2_SET_INCOMPAT_FEATURE(sb,mask)                      \
 526        EXT2_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
 527#define EXT2_CLEAR_COMPAT_FEATURE(sb,mask)                      \
 528        EXT2_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
 529#define EXT2_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
 530        EXT2_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
 531#define EXT2_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
 532        EXT2_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
 533
 534#define EXT2_FEATURE_COMPAT_DIR_PREALLOC        0x0001
 535#define EXT2_FEATURE_COMPAT_IMAGIC_INODES       0x0002
 536#define EXT3_FEATURE_COMPAT_HAS_JOURNAL         0x0004
 537#define EXT2_FEATURE_COMPAT_EXT_ATTR            0x0008
 538#define EXT2_FEATURE_COMPAT_RESIZE_INO          0x0010
 539#define EXT2_FEATURE_COMPAT_DIR_INDEX           0x0020
 540#define EXT2_FEATURE_COMPAT_ANY                 0xffffffff
 541
 542#define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
 543#define EXT2_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
 544#define EXT2_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
 545#define EXT2_FEATURE_RO_COMPAT_ANY              0xffffffff
 546
 547#define EXT2_FEATURE_INCOMPAT_COMPRESSION       0x0001
 548#define EXT2_FEATURE_INCOMPAT_FILETYPE          0x0002
 549#define EXT3_FEATURE_INCOMPAT_RECOVER           0x0004
 550#define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008
 551#define EXT2_FEATURE_INCOMPAT_META_BG           0x0010
 552#define EXT2_FEATURE_INCOMPAT_ANY               0xffffffff
 553
 554#define EXT2_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
 555#define EXT2_FEATURE_INCOMPAT_SUPP      (EXT2_FEATURE_INCOMPAT_FILETYPE| \
 556                                         EXT2_FEATURE_INCOMPAT_META_BG)
 557#define EXT2_FEATURE_RO_COMPAT_SUPP     (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
 558                                         EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
 559                                         EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
 560#define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED      ~EXT2_FEATURE_RO_COMPAT_SUPP
 561#define EXT2_FEATURE_INCOMPAT_UNSUPPORTED       ~EXT2_FEATURE_INCOMPAT_SUPP
 562
 563/*
 564 * Default values for user and/or group using reserved blocks
 565 */
 566#define EXT2_DEF_RESUID         0
 567#define EXT2_DEF_RESGID         0
 568
 569/*
 570 * Default mount options
 571 */
 572#define EXT2_DEFM_DEBUG         0x0001
 573#define EXT2_DEFM_BSDGROUPS     0x0002
 574#define EXT2_DEFM_XATTR_USER    0x0004
 575#define EXT2_DEFM_ACL           0x0008
 576#define EXT2_DEFM_UID16         0x0010
 577    /* Not used by ext2, but reserved for use by ext3 */
 578#define EXT3_DEFM_JMODE         0x0060 
 579#define EXT3_DEFM_JMODE_DATA    0x0020
 580#define EXT3_DEFM_JMODE_ORDERED 0x0040
 581#define EXT3_DEFM_JMODE_WBACK   0x0060
 582
 583/*
 584 * Structure of a directory entry
 585 */
 586
 587struct ext2_dir_entry {
 588        __le32  inode;                  /* Inode number */
 589        __le16  rec_len;                /* Directory entry length */
 590        __le16  name_len;               /* Name length */
 591        char    name[];                 /* File name, up to EXT2_NAME_LEN */
 592};
 593
 594/*
 595 * The new version of the directory entry.  Since EXT2 structures are
 596 * stored in intel byte order, and the name_len field could never be
 597 * bigger than 255 chars, it's safe to reclaim the extra byte for the
 598 * file_type field.
 599 */
 600struct ext2_dir_entry_2 {
 601        __le32  inode;                  /* Inode number */
 602        __le16  rec_len;                /* Directory entry length */
 603        __u8    name_len;               /* Name length */
 604        __u8    file_type;
 605        char    name[];                 /* File name, up to EXT2_NAME_LEN */
 606};
 607
 608/*
 609 * Ext2 directory file types.  Only the low 3 bits are used.  The
 610 * other bits are reserved for now.
 611 */
 612enum {
 613        EXT2_FT_UNKNOWN         = 0,
 614        EXT2_FT_REG_FILE        = 1,
 615        EXT2_FT_DIR             = 2,
 616        EXT2_FT_CHRDEV          = 3,
 617        EXT2_FT_BLKDEV          = 4,
 618        EXT2_FT_FIFO            = 5,
 619        EXT2_FT_SOCK            = 6,
 620        EXT2_FT_SYMLINK         = 7,
 621        EXT2_FT_MAX
 622};
 623
 624/*
 625 * EXT2_DIR_PAD defines the directory entries boundaries
 626 *
 627 * NOTE: It must be a multiple of 4
 628 */
 629#define EXT2_DIR_PAD                    4
 630#define EXT2_DIR_ROUND                  (EXT2_DIR_PAD - 1)
 631#define EXT2_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT2_DIR_ROUND) & \
 632                                         ~EXT2_DIR_ROUND)
 633#define EXT2_MAX_REC_LEN                ((1<<16)-1)
 634
 635static inline void verify_offsets(void)
 636{
 637#define A(x,y) BUILD_BUG_ON(x != offsetof(struct ext2_super_block, y));
 638        A(EXT2_SB_MAGIC_OFFSET, s_magic);
 639        A(EXT2_SB_BLOCKS_OFFSET, s_blocks_count);
 640        A(EXT2_SB_BSIZE_OFFSET, s_log_block_size);
 641#undef A
 642}
 643
 644/*
 645 * ext2 mount options
 646 */
 647struct ext2_mount_options {
 648        unsigned long s_mount_opt;
 649        kuid_t s_resuid;
 650        kgid_t s_resgid;
 651};
 652
 653/*
 654 * second extended file system inode data in memory
 655 */
 656struct ext2_inode_info {
 657        __le32  i_data[15];
 658        __u32   i_flags;
 659        __u32   i_faddr;
 660        __u8    i_frag_no;
 661        __u8    i_frag_size;
 662        __u16   i_state;
 663        __u32   i_file_acl;
 664        __u32   i_dir_acl;
 665        __u32   i_dtime;
 666
 667        /*
 668         * i_block_group is the number of the block group which contains
 669         * this file's inode.  Constant across the lifetime of the inode,
 670         * it is used for making block allocation decisions - we try to
 671         * place a file's data blocks near its inode block, and new inodes
 672         * near to their parent directory's inode.
 673         */
 674        __u32   i_block_group;
 675
 676        /* block reservation info */
 677        struct ext2_block_alloc_info *i_block_alloc_info;
 678
 679        __u32   i_dir_start_lookup;
 680#ifdef CONFIG_EXT2_FS_XATTR
 681        /*
 682         * Extended attributes can be read independently of the main file
 683         * data. Taking i_mutex even when reading would cause contention
 684         * between readers of EAs and writers of regular file data, so
 685         * instead we synchronize on xattr_sem when reading or changing
 686         * EAs.
 687         */
 688        struct rw_semaphore xattr_sem;
 689#endif
 690        rwlock_t i_meta_lock;
 691#ifdef CONFIG_FS_DAX
 692        struct rw_semaphore dax_sem;
 693#endif
 694
 695        /*
 696         * truncate_mutex is for serialising ext2_truncate() against
 697         * ext2_getblock().  It also protects the internals of the inode's
 698         * reservation data structures: ext2_reserve_window and
 699         * ext2_reserve_window_node.
 700         */
 701        struct mutex truncate_mutex;
 702        struct inode    vfs_inode;
 703        struct list_head i_orphan;      /* unlinked but open inodes */
 704#ifdef CONFIG_QUOTA
 705        struct dquot *i_dquot[MAXQUOTAS];
 706#endif
 707};
 708
 709#ifdef CONFIG_FS_DAX
 710#define dax_sem_down_write(ext2_inode)  down_write(&(ext2_inode)->dax_sem)
 711#define dax_sem_up_write(ext2_inode)    up_write(&(ext2_inode)->dax_sem)
 712#else
 713#define dax_sem_down_write(ext2_inode)
 714#define dax_sem_up_write(ext2_inode)
 715#endif
 716
 717/*
 718 * Inode dynamic state flags
 719 */
 720#define EXT2_STATE_NEW                  0x00000001 /* inode is newly created */
 721
 722
 723/*
 724 * Function prototypes
 725 */
 726
 727/*
 728 * Ok, these declarations are also in <linux/kernel.h> but none of the
 729 * ext2 source programs needs to include it so they are duplicated here.
 730 */
 731
 732static inline struct ext2_inode_info *EXT2_I(struct inode *inode)
 733{
 734        return container_of(inode, struct ext2_inode_info, vfs_inode);
 735}
 736
 737/* balloc.c */
 738extern int ext2_bg_has_super(struct super_block *sb, int group);
 739extern unsigned long ext2_bg_num_gdb(struct super_block *sb, int group);
 740extern ext2_fsblk_t ext2_new_block(struct inode *, unsigned long, int *);
 741extern ext2_fsblk_t ext2_new_blocks(struct inode *, unsigned long,
 742                                unsigned long *, int *);
 743extern int ext2_data_block_valid(struct ext2_sb_info *sbi, ext2_fsblk_t start_blk,
 744                                 unsigned int count);
 745extern void ext2_free_blocks (struct inode *, unsigned long,
 746                              unsigned long);
 747extern unsigned long ext2_count_free_blocks (struct super_block *);
 748extern unsigned long ext2_count_dirs (struct super_block *);
 749extern void ext2_check_blocks_bitmap (struct super_block *);
 750extern struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb,
 751                                                    unsigned int block_group,
 752                                                    struct buffer_head ** bh);
 753extern void ext2_discard_reservation (struct inode *);
 754extern int ext2_should_retry_alloc(struct super_block *sb, int *retries);
 755extern void ext2_init_block_alloc_info(struct inode *);
 756extern void ext2_rsv_window_add(struct super_block *sb, struct ext2_reserve_window_node *rsv);
 757
 758/* dir.c */
 759extern int ext2_add_link (struct dentry *, struct inode *);
 760extern ino_t ext2_inode_by_name(struct inode *, const struct qstr *);
 761extern int ext2_make_empty(struct inode *, struct inode *);
 762extern struct ext2_dir_entry_2 * ext2_find_entry (struct inode *,const struct qstr *, struct page **);
 763extern int ext2_delete_entry (struct ext2_dir_entry_2 *, struct page *);
 764extern int ext2_empty_dir (struct inode *);
 765extern struct ext2_dir_entry_2 * ext2_dotdot (struct inode *, struct page **);
 766extern void ext2_set_link(struct inode *, struct ext2_dir_entry_2 *, struct page *, struct inode *, int);
 767
 768/* ialloc.c */
 769extern struct inode * ext2_new_inode (struct inode *, umode_t, const struct qstr *);
 770extern void ext2_free_inode (struct inode *);
 771extern unsigned long ext2_count_free_inodes (struct super_block *);
 772extern void ext2_check_inodes_bitmap (struct super_block *);
 773extern unsigned long ext2_count_free (struct buffer_head *, unsigned);
 774
 775/* inode.c */
 776extern struct inode *ext2_iget (struct super_block *, unsigned long);
 777extern int ext2_write_inode (struct inode *, struct writeback_control *);
 778extern void ext2_evict_inode(struct inode *);
 779extern int ext2_get_block(struct inode *, sector_t, struct buffer_head *, int);
 780extern int ext2_setattr (struct dentry *, struct iattr *);
 781extern void ext2_set_inode_flags(struct inode *inode);
 782extern void ext2_get_inode_flags(struct ext2_inode_info *);
 783extern int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 784                       u64 start, u64 len);
 785
 786/* ioctl.c */
 787extern long ext2_ioctl(struct file *, unsigned int, unsigned long);
 788extern long ext2_compat_ioctl(struct file *, unsigned int, unsigned long);
 789
 790/* namei.c */
 791struct dentry *ext2_get_parent(struct dentry *child);
 792
 793/* super.c */
 794extern __printf(3, 4)
 795void ext2_error(struct super_block *, const char *, const char *, ...);
 796extern __printf(3, 4)
 797void ext2_msg(struct super_block *, const char *, const char *, ...);
 798extern void ext2_update_dynamic_rev (struct super_block *sb);
 799extern void ext2_write_super (struct super_block *);
 800
 801/*
 802 * Inodes and files operations
 803 */
 804
 805/* dir.c */
 806extern const struct file_operations ext2_dir_operations;
 807
 808/* file.c */
 809extern int ext2_fsync(struct file *file, loff_t start, loff_t end,
 810                      int datasync);
 811extern const struct inode_operations ext2_file_inode_operations;
 812extern const struct file_operations ext2_file_operations;
 813
 814/* inode.c */
 815extern const struct address_space_operations ext2_aops;
 816extern const struct address_space_operations ext2_nobh_aops;
 817extern struct iomap_ops ext2_iomap_ops;
 818
 819/* namei.c */
 820extern const struct inode_operations ext2_dir_inode_operations;
 821extern const struct inode_operations ext2_special_inode_operations;
 822
 823/* symlink.c */
 824extern const struct inode_operations ext2_fast_symlink_inode_operations;
 825extern const struct inode_operations ext2_symlink_inode_operations;
 826
 827static inline ext2_fsblk_t
 828ext2_group_first_block_no(struct super_block *sb, unsigned long group_no)
 829{
 830        return group_no * (ext2_fsblk_t)EXT2_BLOCKS_PER_GROUP(sb) +
 831                le32_to_cpu(EXT2_SB(sb)->s_es->s_first_data_block);
 832}
 833
 834#define ext2_set_bit    __test_and_set_bit_le
 835#define ext2_clear_bit  __test_and_clear_bit_le
 836#define ext2_test_bit   test_bit_le
 837#define ext2_find_first_zero_bit        find_first_zero_bit_le
 838#define ext2_find_next_zero_bit         find_next_zero_bit_le
 839