LXR linux/fs/ext2/ext2.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * Copyright (C) 1992, 1993, 1994, 1995
   4 * Remy Card (card@masi.ibp.fr)
   5 * Laboratoire MASI - Institut Blaise Pascal
   6 * Universite Pierre et Marie Curie (Paris VI)
   7 *
   8 *  from
   9 *
  10 *  linux/include/linux/minix_fs.h
  11 *
  12 *  Copyright (C) 1991, 1992  Linus Torvalds
  13 */
  14#include <linux/fs.h>
  15#include <linux/ext2_fs.h>
  16#include <linux/blockgroup_lock.h>
  17#include <linux/percpu_counter.h>
  18#include <linux/rbtree.h>
  19#include <linux/mm.h>
  20#include <linux/highmem.h>
  21
  22/* XXX Here for now... not interested in restructing headers JUST now */
  23
  24/* data type for block offset of block group */
  25typedef int ext2_grpblk_t;
  26
  27/* data type for filesystem-wide blocks number */
  28typedef unsigned long ext2_fsblk_t;
  29
  30#define E2FSBLK "%lu"
  31
  32struct ext2_reserve_window {
  33        ext2_fsblk_t            _rsv_start;     /* First byte reserved */
  34        ext2_fsblk_t            _rsv_end;       /* Last byte reserved or 0 */
  35};
  36
  37struct ext2_reserve_window_node {
  38        struct rb_node          rsv_node;
  39        __u32                   rsv_goal_size;
  40        __u32                   rsv_alloc_hit;
  41        struct ext2_reserve_window      rsv_window;
  42};
  43
  44struct ext2_block_alloc_info {
  45        /* information about reservation window */
  46        struct ext2_reserve_window_node rsv_window_node;
  47        /*
  48         * was i_next_alloc_block in ext2_inode_info
  49         * is the logical (file-relative) number of the
  50         * most-recently-allocated block in this file.
  51         * We use this for detecting linearly ascending allocation requests.
  52         */
  53        __u32                   last_alloc_logical_block;
  54        /*
  55         * Was i_next_alloc_goal in ext2_inode_info
  56         * is the *physical* companion to i_next_alloc_block.
  57         * it is the physical block number of the block which was most-recently
  58         * allocated to this file.  This gives us the goal (target) for the next
  59         * allocation when we detect linearly ascending requests.
  60         */
  61        ext2_fsblk_t            last_alloc_physical_block;
  62};
  63
  64#define rsv_start rsv_window._rsv_start
  65#define rsv_end rsv_window._rsv_end
  66
  67struct mb_cache;
  68
  69/*
  70 * second extended-fs super-block data in memory
  71 */
  72struct ext2_sb_info {
  73        unsigned long s_frag_size;      /* Size of a fragment in bytes */
  74        unsigned long s_frags_per_block;/* Number of fragments per block */
  75        unsigned long s_inodes_per_block;/* Number of inodes per block */
  76        unsigned long s_frags_per_group;/* Number of fragments in a group */
  77        unsigned long s_blocks_per_group;/* Number of blocks in a group */
  78        unsigned long s_inodes_per_group;/* Number of inodes in a group */
  79        unsigned long s_itb_per_group;  /* Number of inode table blocks per group */
  80        unsigned long s_gdb_count;      /* Number of group descriptor blocks */
  81        unsigned long s_desc_per_block; /* Number of group descriptors per block */
  82        unsigned long s_groups_count;   /* Number of groups in the fs */
  83        unsigned long s_overhead_last;  /* Last calculated overhead */
  84        unsigned long s_blocks_last;    /* Last seen block count */
  85        struct buffer_head * s_sbh;     /* Buffer containing the super block */
  86        struct ext2_super_block * s_es; /* Pointer to the super block in the buffer */
  87        struct buffer_head ** s_group_desc;
  88        unsigned long  s_mount_opt;
  89        unsigned long s_sb_block;
  90        kuid_t s_resuid;
  91        kgid_t s_resgid;
  92        unsigned short s_mount_state;
  93        unsigned short s_pad;
  94        int s_addr_per_block_bits;
  95        int s_desc_per_block_bits;
  96        int s_inode_size;
  97        int s_first_ino;
  98        spinlock_t s_next_gen_lock;
  99        u32 s_next_generation;
 100        unsigned long s_dir_count;
 101        u8 *s_debts;
 102        struct percpu_counter s_freeblocks_counter;
 103        struct percpu_counter s_freeinodes_counter;
 104        struct percpu_counter s_dirs_counter;
 105        struct blockgroup_lock *s_blockgroup_lock;
 106        /* root of the per fs reservation window tree */
 107        spinlock_t s_rsv_window_lock;
 108        struct rb_root s_rsv_window_root;
 109        struct ext2_reserve_window_node s_rsv_window_head;
 110        /*
 111         * s_lock protects against concurrent modifications of s_mount_state,
 112         * s_blocks_last, s_overhead_last and the content of superblock's
 113         * buffer pointed to by sbi->s_es.
 114         *
 115         * Note: It is used in ext2_show_options() to provide a consistent view
 116         * of the mount options.
 117         */
 118        spinlock_t s_lock;
 119        struct mb_cache *s_ea_block_cache;
 120        struct dax_device *s_daxdev;
 121};
 122
 123static inline spinlock_t *
 124sb_bgl_lock(struct ext2_sb_info *sbi, unsigned int block_group)
 125{
 126        return bgl_lock_ptr(sbi->s_blockgroup_lock, block_group);
 127}
 128
 129/*
 130 * Define EXT2FS_DEBUG to produce debug messages
 131 */
 132#undef EXT2FS_DEBUG
 133
 134/*
 135 * Define EXT2_RESERVATION to reserve data blocks for expanding files
 136 */
 137#define EXT2_DEFAULT_RESERVE_BLOCKS     8
 138/*max window size: 1024(direct blocks) + 3([t,d]indirect blocks) */
 139#define EXT2_MAX_RESERVE_BLOCKS         1027
 140#define EXT2_RESERVE_WINDOW_NOT_ALLOCATED 0
 141/*
 142 * The second extended file system version
 143 */
 144#define EXT2FS_DATE             "95/08/09"
 145#define EXT2FS_VERSION          "0.5b"
 146
 147/*
 148 * Debug code
 149 */
 150#ifdef EXT2FS_DEBUG
 151#       define ext2_debug(f, a...)      { \
 152                                        printk ("EXT2-fs DEBUG (%s, %d): %s:", \
 153                                                __FILE__, __LINE__, __func__); \
 154                                        printk (f, ## a); \
 155                                        }
 156#else
 157#       define ext2_debug(f, a...)      /**/
 158#endif
 159
 160/*
 161 * Special inode numbers
 162 */
 163#define EXT2_BAD_INO             1      /* Bad blocks inode */
 164#define EXT2_ROOT_INO            2      /* Root inode */
 165#define EXT2_BOOT_LOADER_INO     5      /* Boot loader inode */
 166#define EXT2_UNDEL_DIR_INO       6      /* Undelete directory inode */
 167
 168/* First non-reserved inode for old ext2 filesystems */
 169#define EXT2_GOOD_OLD_FIRST_INO 11
 170
 171static inline struct ext2_sb_info *EXT2_SB(struct super_block *sb)
 172{
 173        return sb->s_fs_info;
 174}
 175
 176/*
 177 * Macro-instructions used to manage several block sizes
 178 */
 179#define EXT2_MIN_BLOCK_SIZE             1024
 180#define EXT2_MAX_BLOCK_SIZE             4096
 181#define EXT2_MIN_BLOCK_LOG_SIZE           10
 182#define EXT2_BLOCK_SIZE(s)              ((s)->s_blocksize)
 183#define EXT2_ADDR_PER_BLOCK(s)          (EXT2_BLOCK_SIZE(s) / sizeof (__u32))
 184#define EXT2_BLOCK_SIZE_BITS(s)         ((s)->s_blocksize_bits)
 185#define EXT2_ADDR_PER_BLOCK_BITS(s)     (EXT2_SB(s)->s_addr_per_block_bits)
 186#define EXT2_INODE_SIZE(s)              (EXT2_SB(s)->s_inode_size)
 187#define EXT2_FIRST_INO(s)               (EXT2_SB(s)->s_first_ino)
 188
 189/*
 190 * Macro-instructions used to manage fragments
 191 */
 192#define EXT2_MIN_FRAG_SIZE              1024
 193#define EXT2_MAX_FRAG_SIZE              4096
 194#define EXT2_MIN_FRAG_LOG_SIZE            10
 195#define EXT2_FRAG_SIZE(s)               (EXT2_SB(s)->s_frag_size)
 196#define EXT2_FRAGS_PER_BLOCK(s)         (EXT2_SB(s)->s_frags_per_block)
 197
 198/*
 199 * Structure of a blocks group descriptor
 200 */
 201struct ext2_group_desc
 202{
 203        __le32  bg_block_bitmap;                /* Blocks bitmap block */
 204        __le32  bg_inode_bitmap;                /* Inodes bitmap block */
 205        __le32  bg_inode_table;         /* Inodes table block */
 206        __le16  bg_free_blocks_count;   /* Free blocks count */
 207        __le16  bg_free_inodes_count;   /* Free inodes count */
 208        __le16  bg_used_dirs_count;     /* Directories count */
 209        __le16  bg_pad;
 210        __le32  bg_reserved[3];
 211};
 212
 213/*
 214 * Macro-instructions used to manage group descriptors
 215 */
 216#define EXT2_BLOCKS_PER_GROUP(s)        (EXT2_SB(s)->s_blocks_per_group)
 217#define EXT2_DESC_PER_BLOCK(s)          (EXT2_SB(s)->s_desc_per_block)
 218#define EXT2_INODES_PER_GROUP(s)        (EXT2_SB(s)->s_inodes_per_group)
 219#define EXT2_DESC_PER_BLOCK_BITS(s)     (EXT2_SB(s)->s_desc_per_block_bits)
 220
 221/*
 222 * Constants relative to the data blocks
 223 */
 224#define EXT2_NDIR_BLOCKS                12
 225#define EXT2_IND_BLOCK                  EXT2_NDIR_BLOCKS
 226#define EXT2_DIND_BLOCK                 (EXT2_IND_BLOCK + 1)
 227#define EXT2_TIND_BLOCK                 (EXT2_DIND_BLOCK + 1)
 228#define EXT2_N_BLOCKS                   (EXT2_TIND_BLOCK + 1)
 229
 230/*
 231 * Inode flags (GETFLAGS/SETFLAGS)
 232 */
 233#define EXT2_SECRM_FL                   FS_SECRM_FL     /* Secure deletion */
 234#define EXT2_UNRM_FL                    FS_UNRM_FL      /* Undelete */
 235#define EXT2_COMPR_FL                   FS_COMPR_FL     /* Compress file */
 236#define EXT2_SYNC_FL                    FS_SYNC_FL      /* Synchronous updates */
 237#define EXT2_IMMUTABLE_FL               FS_IMMUTABLE_FL /* Immutable file */
 238#define EXT2_APPEND_FL                  FS_APPEND_FL    /* writes to file may only append */
 239#define EXT2_NODUMP_FL                  FS_NODUMP_FL    /* do not dump file */
 240#define EXT2_NOATIME_FL                 FS_NOATIME_FL   /* do not update atime */
 241/* Reserved for compression usage... */
 242#define EXT2_DIRTY_FL                   FS_DIRTY_FL
 243#define EXT2_COMPRBLK_FL                FS_COMPRBLK_FL  /* One or more compressed clusters */
 244#define EXT2_NOCOMP_FL                  FS_NOCOMP_FL    /* Don't compress */
 245#define EXT2_ECOMPR_FL                  FS_ECOMPR_FL    /* Compression error */
 246/* End compression flags --- maybe not all used */      
 247#define EXT2_BTREE_FL                   FS_BTREE_FL     /* btree format dir */
 248#define EXT2_INDEX_FL                   FS_INDEX_FL     /* hash-indexed directory */
 249#define EXT2_IMAGIC_FL                  FS_IMAGIC_FL    /* AFS directory */
 250#define EXT2_JOURNAL_DATA_FL            FS_JOURNAL_DATA_FL /* Reserved for ext3 */
 251#define EXT2_NOTAIL_FL                  FS_NOTAIL_FL    /* file tail should not be merged */
 252#define EXT2_DIRSYNC_FL                 FS_DIRSYNC_FL   /* dirsync behaviour (directories only) */
 253#define EXT2_TOPDIR_FL                  FS_TOPDIR_FL    /* Top of directory hierarchies*/
 254#define EXT2_RESERVED_FL                FS_RESERVED_FL  /* reserved for ext2 lib */
 255
 256#define EXT2_FL_USER_VISIBLE            FS_FL_USER_VISIBLE      /* User visible flags */
 257#define EXT2_FL_USER_MODIFIABLE         FS_FL_USER_MODIFIABLE   /* User modifiable flags */
 258
 259/* Flags that should be inherited by new inodes from their parent. */
 260#define EXT2_FL_INHERITED (EXT2_SECRM_FL | EXT2_UNRM_FL | EXT2_COMPR_FL |\
 261                           EXT2_SYNC_FL | EXT2_NODUMP_FL |\
 262                           EXT2_NOATIME_FL | EXT2_COMPRBLK_FL |\
 263                           EXT2_NOCOMP_FL | EXT2_JOURNAL_DATA_FL |\
 264                           EXT2_NOTAIL_FL | EXT2_DIRSYNC_FL)
 265
 266/* Flags that are appropriate for regular files (all but dir-specific ones). */
 267#define EXT2_REG_FLMASK (~(EXT2_DIRSYNC_FL | EXT2_TOPDIR_FL))
 268
 269/* Flags that are appropriate for non-directories/regular files. */
 270#define EXT2_OTHER_FLMASK (EXT2_NODUMP_FL | EXT2_NOATIME_FL)
 271
 272/* Mask out flags that are inappropriate for the given type of inode. */
 273static inline __u32 ext2_mask_flags(umode_t mode, __u32 flags)
 274{
 275        if (S_ISDIR(mode))
 276                return flags;
 277        else if (S_ISREG(mode))
 278                return flags & EXT2_REG_FLMASK;
 279        else
 280                return flags & EXT2_OTHER_FLMASK;
 281}
 282
 283/*
 284 * ioctl commands
 285 */
 286#define EXT2_IOC_GETVERSION             FS_IOC_GETVERSION
 287#define EXT2_IOC_SETVERSION             FS_IOC_SETVERSION
 288#define EXT2_IOC_GETRSVSZ               _IOR('f', 5, long)
 289#define EXT2_IOC_SETRSVSZ               _IOW('f', 6, long)
 290
 291/*
 292 * ioctl commands in 32 bit emulation
 293 */
 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_OLDALLOC             0x000002  /* Don't use the new Orlov allocator */
 376#define EXT2_MOUNT_GRPID                0x000004  /* Create files with directory's group */
 377#define EXT2_MOUNT_DEBUG                0x000008  /* Some debugging messages */
 378#define EXT2_MOUNT_ERRORS_CONT          0x000010  /* Continue on errors */
 379#define EXT2_MOUNT_ERRORS_RO            0x000020  /* Remount fs ro on errors */
 380#define EXT2_MOUNT_ERRORS_PANIC         0x000040  /* Panic on errors */
 381#define EXT2_MOUNT_MINIX_DF             0x000080  /* Mimics the Minix statfs */
 382#define EXT2_MOUNT_NOBH                 0x000100  /* No buffer_heads */
 383#define EXT2_MOUNT_NO_UID32             0x000200  /* Disable 32-bit UIDs */
 384#define EXT2_MOUNT_XATTR_USER           0x004000  /* Extended user attributes */
 385#define EXT2_MOUNT_POSIX_ACL            0x008000  /* POSIX Access Control Lists */
 386#define EXT2_MOUNT_XIP                  0x010000  /* Obsolete, use DAX */
 387#define EXT2_MOUNT_USRQUOTA             0x020000  /* user quota */
 388#define EXT2_MOUNT_GRPQUOTA             0x040000  /* group quota */
 389#define EXT2_MOUNT_RESERVATION          0x080000  /* Preallocation */
 390#define EXT2_MOUNT_DAX                  0x100000  /* Direct Access */
 391
 392
 393#define clear_opt(o, opt)               o &= ~EXT2_MOUNT_##opt
 394#define set_opt(o, opt)                 o |= EXT2_MOUNT_##opt
 395#define test_opt(sb, opt)               (EXT2_SB(sb)->s_mount_opt & \
 396                                         EXT2_MOUNT_##opt)
 397/*
 398 * Maximal mount counts between two filesystem checks
 399 */
 400#define EXT2_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
 401#define EXT2_DFL_CHECKINTERVAL          0       /* Don't use interval check */
 402
 403/*
 404 * Behaviour when detecting errors
 405 */
 406#define EXT2_ERRORS_CONTINUE            1       /* Continue execution */
 407#define EXT2_ERRORS_RO                  2       /* Remount fs read-only */
 408#define EXT2_ERRORS_PANIC               3       /* Panic */
 409#define EXT2_ERRORS_DEFAULT             EXT2_ERRORS_CONTINUE
 410
 411/*
 412 * Structure of the super block
 413 */
 414struct ext2_super_block {
 415        __le32  s_inodes_count;         /* Inodes count */
 416        __le32  s_blocks_count;         /* Blocks count */
 417        __le32  s_r_blocks_count;       /* Reserved blocks count */
 418        __le32  s_free_blocks_count;    /* Free blocks count */
 419        __le32  s_free_inodes_count;    /* Free inodes count */
 420        __le32  s_first_data_block;     /* First Data Block */
 421        __le32  s_log_block_size;       /* Block size */
 422        __le32  s_log_frag_size;        /* Fragment size */
 423        __le32  s_blocks_per_group;     /* # Blocks per group */
 424        __le32  s_frags_per_group;      /* # Fragments per group */
 425        __le32  s_inodes_per_group;     /* # Inodes per group */
 426        __le32  s_mtime;                /* Mount time */
 427        __le32  s_wtime;                /* Write time */
 428        __le16  s_mnt_count;            /* Mount count */
 429        __le16  s_max_mnt_count;        /* Maximal mount count */
 430        __le16  s_magic;                /* Magic signature */
 431        __le16  s_state;                /* File system state */
 432        __le16  s_errors;               /* Behaviour when detecting errors */
 433        __le16  s_minor_rev_level;      /* minor revision level */
 434        __le32  s_lastcheck;            /* time of last check */
 435        __le32  s_checkinterval;        /* max. time between checks */
 436        __le32  s_creator_os;           /* OS */
 437        __le32  s_rev_level;            /* Revision level */
 438        __le16  s_def_resuid;           /* Default uid for reserved blocks */
 439        __le16  s_def_resgid;           /* Default gid for reserved blocks */
 440        /*
 441         * These fields are for EXT2_DYNAMIC_REV superblocks only.
 442         *
 443         * Note: the difference between the compatible feature set and
 444         * the incompatible feature set is that if there is a bit set
 445         * in the incompatible feature set that the kernel doesn't
 446         * know about, it should refuse to mount the filesystem.
 447         * 
 448         * e2fsck's requirements are more strict; if it doesn't know
 449         * about a feature in either the compatible or incompatible
 450         * feature set, it must abort and not try to meddle with
 451         * things it doesn't understand...
 452         */
 453        __le32  s_first_ino;            /* First non-reserved inode */
 454        __le16   s_inode_size;          /* size of inode structure */
 455        __le16  s_block_group_nr;       /* block group # of this superblock */
 456        __le32  s_feature_compat;       /* compatible feature set */
 457        __le32  s_feature_incompat;     /* incompatible feature set */
 458        __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
 459        __u8    s_uuid[16];             /* 128-bit uuid for volume */
 460        char    s_volume_name[16];      /* volume name */
 461        char    s_last_mounted[64];     /* directory where last mounted */
 462        __le32  s_algorithm_usage_bitmap; /* For compression */
 463        /*
 464         * Performance hints.  Directory preallocation should only
 465         * happen if the EXT2_COMPAT_PREALLOC flag is on.
 466         */
 467        __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
 468        __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
 469        __u16   s_padding1;
 470        /*
 471         * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set.
 472         */
 473        __u8    s_journal_uuid[16];     /* uuid of journal superblock */
 474        __u32   s_journal_inum;         /* inode number of journal file */
 475        __u32   s_journal_dev;          /* device number of journal file */
 476        __u32   s_last_orphan;          /* start of list of inodes to delete */
 477        __u32   s_hash_seed[4];         /* HTREE hash seed */
 478        __u8    s_def_hash_version;     /* Default hash version to use */
 479        __u8    s_reserved_char_pad;
 480        __u16   s_reserved_word_pad;
 481        __le32  s_default_mount_opts;
 482        __le32  s_first_meta_bg;        /* First metablock block group */
 483        __u32   s_reserved[190];        /* Padding to the end of the block */
 484};
 485
 486/*
 487 * Codes for operating systems
 488 */
 489#define EXT2_OS_LINUX           0
 490#define EXT2_OS_HURD            1
 491#define EXT2_OS_MASIX           2
 492#define EXT2_OS_FREEBSD         3
 493#define EXT2_OS_LITES           4
 494
 495/*
 496 * Revision levels
 497 */
 498#define EXT2_GOOD_OLD_REV       0       /* The good old (original) format */
 499#define EXT2_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
 500
 501#define EXT2_CURRENT_REV        EXT2_GOOD_OLD_REV
 502#define EXT2_MAX_SUPP_REV       EXT2_DYNAMIC_REV
 503
 504#define EXT2_GOOD_OLD_INODE_SIZE 128
 505
 506/*
 507 * Feature set definitions
 508 */
 509
 510#define EXT2_HAS_COMPAT_FEATURE(sb,mask)                        \
 511        ( EXT2_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) )
 512#define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
 513        ( EXT2_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) )
 514#define EXT2_HAS_INCOMPAT_FEATURE(sb,mask)                      \
 515        ( EXT2_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) )
 516#define EXT2_SET_COMPAT_FEATURE(sb,mask)                        \
 517        EXT2_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
 518#define EXT2_SET_RO_COMPAT_FEATURE(sb,mask)                     \
 519        EXT2_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
 520#define EXT2_SET_INCOMPAT_FEATURE(sb,mask)                      \
 521        EXT2_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
 522#define EXT2_CLEAR_COMPAT_FEATURE(sb,mask)                      \
 523        EXT2_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
 524#define EXT2_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
 525        EXT2_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
 526#define EXT2_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
 527        EXT2_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
 528
 529#define EXT2_FEATURE_COMPAT_DIR_PREALLOC        0x0001
 530#define EXT2_FEATURE_COMPAT_IMAGIC_INODES       0x0002
 531#define EXT3_FEATURE_COMPAT_HAS_JOURNAL         0x0004
 532#define EXT2_FEATURE_COMPAT_EXT_ATTR            0x0008
 533#define EXT2_FEATURE_COMPAT_RESIZE_INO          0x0010
 534#define EXT2_FEATURE_COMPAT_DIR_INDEX           0x0020
 535#define EXT2_FEATURE_COMPAT_ANY                 0xffffffff
 536
 537#define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
 538#define EXT2_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
 539#define EXT2_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
 540#define EXT2_FEATURE_RO_COMPAT_ANY              0xffffffff
 541
 542#define EXT2_FEATURE_INCOMPAT_COMPRESSION       0x0001
 543#define EXT2_FEATURE_INCOMPAT_FILETYPE          0x0002
 544#define EXT3_FEATURE_INCOMPAT_RECOVER           0x0004
 545#define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008
 546#define EXT2_FEATURE_INCOMPAT_META_BG           0x0010
 547#define EXT2_FEATURE_INCOMPAT_ANY               0xffffffff
 548
 549#define EXT2_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
 550#define EXT2_FEATURE_INCOMPAT_SUPP      (EXT2_FEATURE_INCOMPAT_FILETYPE| \
 551                                         EXT2_FEATURE_INCOMPAT_META_BG)
 552#define EXT2_FEATURE_RO_COMPAT_SUPP     (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
 553                                         EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
 554                                         EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
 555#define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED      ~EXT2_FEATURE_RO_COMPAT_SUPP
 556#define EXT2_FEATURE_INCOMPAT_UNSUPPORTED       ~EXT2_FEATURE_INCOMPAT_SUPP
 557
 558/*
 559 * Default values for user and/or group using reserved blocks
 560 */
 561#define EXT2_DEF_RESUID         0
 562#define EXT2_DEF_RESGID         0
 563
 564/*
 565 * Default mount options
 566 */
 567#define EXT2_DEFM_DEBUG         0x0001
 568#define EXT2_DEFM_BSDGROUPS     0x0002
 569#define EXT2_DEFM_XATTR_USER    0x0004
 570#define EXT2_DEFM_ACL           0x0008
 571#define EXT2_DEFM_UID16         0x0010
 572    /* Not used by ext2, but reserved for use by ext3 */
 573#define EXT3_DEFM_JMODE         0x0060 
 574#define EXT3_DEFM_JMODE_DATA    0x0020
 575#define EXT3_DEFM_JMODE_ORDERED 0x0040
 576#define EXT3_DEFM_JMODE_WBACK   0x0060
 577
 578/*
 579 * Structure of a directory entry
 580 */
 581
 582struct ext2_dir_entry {
 583        __le32  inode;                  /* Inode number */
 584        __le16  rec_len;                /* Directory entry length */
 585        __le16  name_len;               /* Name length */
 586        char    name[];                 /* File name, up to EXT2_NAME_LEN */
 587};
 588
 589/*
 590 * The new version of the directory entry.  Since EXT2 structures are
 591 * stored in intel byte order, and the name_len field could never be
 592 * bigger than 255 chars, it's safe to reclaim the extra byte for the
 593 * file_type field.
 594 */
 595struct ext2_dir_entry_2 {
 596        __le32  inode;                  /* Inode number */
 597        __le16  rec_len;                /* Directory entry length */
 598        __u8    name_len;               /* Name length */
 599        __u8    file_type;
 600        char    name[];                 /* File name, up to EXT2_NAME_LEN */
 601};
 602
 603/*
 604 * EXT2_DIR_PAD defines the directory entries boundaries
 605 *
 606 * NOTE: It must be a multiple of 4
 607 */
 608#define EXT2_DIR_PAD                    4
 609#define EXT2_DIR_ROUND                  (EXT2_DIR_PAD - 1)
 610#define EXT2_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT2_DIR_ROUND) & \
 611                                         ~EXT2_DIR_ROUND)
 612#define EXT2_MAX_REC_LEN                ((1<<16)-1)
 613
 614static inline void verify_offsets(void)
 615{
 616#define A(x,y) BUILD_BUG_ON(x != offsetof(struct ext2_super_block, y));
 617        A(EXT2_SB_MAGIC_OFFSET, s_magic);
 618        A(EXT2_SB_BLOCKS_OFFSET, s_blocks_count);
 619        A(EXT2_SB_BSIZE_OFFSET, s_log_block_size);
 620#undef A
 621}
 622
 623/*
 624 * ext2 mount options
 625 */
 626struct ext2_mount_options {
 627        unsigned long s_mount_opt;
 628        kuid_t s_resuid;
 629        kgid_t s_resgid;
 630};
 631
 632/*
 633 * second extended file system inode data in memory
 634 */
 635struct ext2_inode_info {
 636        __le32  i_data[15];
 637        __u32   i_flags;
 638        __u32   i_faddr;
 639        __u8    i_frag_no;
 640        __u8    i_frag_size;
 641        __u16   i_state;
 642        __u32   i_file_acl;
 643        __u32   i_dir_acl;
 644        __u32   i_dtime;
 645
 646        /*
 647         * i_block_group is the number of the block group which contains
 648         * this file's inode.  Constant across the lifetime of the inode,
 649         * it is used for making block allocation decisions - we try to
 650         * place a file's data blocks near its inode block, and new inodes
 651         * near to their parent directory's inode.
 652         */
 653        __u32   i_block_group;
 654
 655        /* block reservation info */
 656        struct ext2_block_alloc_info *i_block_alloc_info;
 657
 658        __u32   i_dir_start_lookup;
 659#ifdef CONFIG_EXT2_FS_XATTR
 660        /*
 661         * Extended attributes can be read independently of the main file
 662         * data. Taking i_mutex even when reading would cause contention
 663         * between readers of EAs and writers of regular file data, so
 664         * instead we synchronize on xattr_sem when reading or changing
 665         * EAs.
 666         */
 667        struct rw_semaphore xattr_sem;
 668#endif
 669        rwlock_t i_meta_lock;
 670
 671        /*
 672         * truncate_mutex is for serialising ext2_truncate() against
 673         * ext2_getblock().  It also protects the internals of the inode's
 674         * reservation data structures: ext2_reserve_window and
 675         * ext2_reserve_window_node.
 676         */
 677        struct mutex truncate_mutex;
 678        struct inode    vfs_inode;
 679        struct list_head i_orphan;      /* unlinked but open inodes */
 680#ifdef CONFIG_QUOTA
 681        struct dquot *i_dquot[MAXQUOTAS];
 682#endif
 683};
 684
 685/*
 686 * Inode dynamic state flags
 687 */
 688#define EXT2_STATE_NEW                  0x00000001 /* inode is newly created */
 689
 690
 691/*
 692 * Function prototypes
 693 */
 694
 695/*
 696 * Ok, these declarations are also in <linux/kernel.h> but none of the
 697 * ext2 source programs needs to include it so they are duplicated here.
 698 */
 699
 700static inline struct ext2_inode_info *EXT2_I(struct inode *inode)
 701{
 702        return container_of(inode, struct ext2_inode_info, vfs_inode);
 703}
 704
 705/* balloc.c */
 706extern int ext2_bg_has_super(struct super_block *sb, int group);
 707extern unsigned long ext2_bg_num_gdb(struct super_block *sb, int group);
 708extern ext2_fsblk_t ext2_new_block(struct inode *, unsigned long, int *);
 709extern ext2_fsblk_t ext2_new_blocks(struct inode *, unsigned long,
 710                                unsigned long *, int *);
 711extern int ext2_data_block_valid(struct ext2_sb_info *sbi, ext2_fsblk_t start_blk,
 712                                 unsigned int count);
 713extern void ext2_free_blocks (struct inode *, unsigned long,
 714                              unsigned long);
 715extern unsigned long ext2_count_free_blocks (struct super_block *);
 716extern unsigned long ext2_count_dirs (struct super_block *);
 717extern struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb,
 718                                                    unsigned int block_group,
 719                                                    struct buffer_head ** bh);
 720extern void ext2_discard_reservation (struct inode *);
 721extern int ext2_should_retry_alloc(struct super_block *sb, int *retries);
 722extern void ext2_init_block_alloc_info(struct inode *);
 723extern void ext2_rsv_window_add(struct super_block *sb, struct ext2_reserve_window_node *rsv);
 724
 725/* dir.c */
 726extern int ext2_add_link (struct dentry *, struct inode *);
 727extern int ext2_inode_by_name(struct inode *dir,
 728                              const struct qstr *child, ino_t *ino);
 729extern int ext2_make_empty(struct inode *, struct inode *);
 730extern struct ext2_dir_entry_2 *ext2_find_entry(struct inode *, const struct qstr *,
 731                                                struct page **, void **res_page_addr);
 732extern int ext2_delete_entry(struct ext2_dir_entry_2 *dir, struct page *page,
 733                             char *kaddr);
 734extern int ext2_empty_dir (struct inode *);
 735extern struct ext2_dir_entry_2 *ext2_dotdot(struct inode *dir, struct page **p, void **pa);
 736extern void ext2_set_link(struct inode *, struct ext2_dir_entry_2 *, struct page *, void *,
 737                          struct inode *, int);
 738static inline void ext2_put_page(struct page *page, void *page_addr)
 739{
 740        kunmap_local(page_addr);
 741        put_page(page);
 742}
 743
 744/* ialloc.c */
 745extern struct inode * ext2_new_inode (struct inode *, umode_t, const struct qstr *);
 746extern void ext2_free_inode (struct inode *);
 747extern unsigned long ext2_count_free_inodes (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 user_namespace *, struct dentry *, struct iattr *);
 756extern int ext2_getattr (struct user_namespace *, const struct path *,
 757                         struct kstat *, u32, unsigned int);
 758extern void ext2_set_inode_flags(struct inode *inode);
 759extern int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 760                       u64 start, u64 len);
 761
 762/* ioctl.c */
 763extern int ext2_fileattr_get(struct dentry *dentry, struct fileattr *fa);
 764extern int ext2_fileattr_set(struct user_namespace *mnt_userns,
 765                             struct dentry *dentry, struct fileattr *fa);
 766extern long ext2_ioctl(struct file *, unsigned int, unsigned long);
 767extern long ext2_compat_ioctl(struct file *, unsigned int, unsigned long);
 768
 769/* namei.c */
 770struct dentry *ext2_get_parent(struct dentry *child);
 771
 772/* super.c */
 773extern __printf(3, 4)
 774void ext2_error(struct super_block *, const char *, const char *, ...);
 775extern __printf(3, 4)
 776void ext2_msg(struct super_block *, const char *, const char *, ...);
 777extern void ext2_update_dynamic_rev (struct super_block *sb);
 778extern void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
 779                            int wait);
 780
 781/*
 782 * Inodes and files operations
 783 */
 784
 785/* dir.c */
 786extern const struct file_operations ext2_dir_operations;
 787
 788/* file.c */
 789extern int ext2_fsync(struct file *file, loff_t start, loff_t end,
 790                      int datasync);
 791extern const struct inode_operations ext2_file_inode_operations;
 792extern const struct file_operations ext2_file_operations;
 793
 794/* inode.c */
 795extern void ext2_set_file_ops(struct inode *inode);
 796extern const struct address_space_operations ext2_aops;
 797extern const struct address_space_operations ext2_nobh_aops;
 798extern const struct iomap_ops ext2_iomap_ops;
 799
 800/* namei.c */
 801extern const struct inode_operations ext2_dir_inode_operations;
 802extern const struct inode_operations ext2_special_inode_operations;
 803
 804/* symlink.c */
 805extern const struct inode_operations ext2_fast_symlink_inode_operations;
 806extern const struct inode_operations ext2_symlink_inode_operations;
 807
 808static inline ext2_fsblk_t
 809ext2_group_first_block_no(struct super_block *sb, unsigned long group_no)
 810{
 811        return group_no * (ext2_fsblk_t)EXT2_BLOCKS_PER_GROUP(sb) +
 812                le32_to_cpu(EXT2_SB(sb)->s_es->s_first_data_block);
 813}
 814
 815static inline ext2_fsblk_t
 816ext2_group_last_block_no(struct super_block *sb, unsigned long group_no)
 817{
 818        struct ext2_sb_info *sbi = EXT2_SB(sb);
 819
 820        if (group_no == sbi->s_groups_count - 1)
 821                return le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 822        else
 823                return ext2_group_first_block_no(sb, group_no) +
 824                        EXT2_BLOCKS_PER_GROUP(sb) - 1;
 825}
 826
 827#define ext2_set_bit    __test_and_set_bit_le
 828#define ext2_clear_bit  __test_and_clear_bit_le
 829#define ext2_test_bit   test_bit_le
 830#define ext2_find_first_zero_bit        find_first_zero_bit_le
 831#define ext2_find_next_zero_bit         find_next_zero_bit_le
 832