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        u64 s_dax_part_off;
 122};
 123
 124static inline spinlock_t *
 125sb_bgl_lock(struct ext2_sb_info *sbi, unsigned int block_group)
 126{
 127        return bgl_lock_ptr(sbi->s_blockgroup_lock, block_group);
 128}
 129
 130/*
 131 * Define EXT2FS_DEBUG to produce debug messages
 132 */
 133#undef EXT2FS_DEBUG
 134
 135/*
 136 * Define EXT2_RESERVATION to reserve data blocks for expanding files
 137 */
 138#define EXT2_DEFAULT_RESERVE_BLOCKS     8
 139/*max window size: 1024(direct blocks) + 3([t,d]indirect blocks) */
 140#define EXT2_MAX_RESERVE_BLOCKS         1027
 141#define EXT2_RESERVE_WINDOW_NOT_ALLOCATED 0
 142/*
 143 * The second extended file system version
 144 */
 145#define EXT2FS_DATE             "95/08/09"
 146#define EXT2FS_VERSION          "0.5b"
 147
 148/*
 149 * Debug code
 150 */
 151#ifdef EXT2FS_DEBUG
 152#       define ext2_debug(f, a...)      { \
 153                                        printk ("EXT2-fs DEBUG (%s, %d): %s:", \
 154                                                __FILE__, __LINE__, __func__); \
 155                                        printk (f, ## a); \
 156                                        }
 157#else
 158#       define ext2_debug(f, a...)      /**/
 159#endif
 160
 161/*
 162 * Special inode numbers
 163 */
 164#define EXT2_BAD_INO             1      /* Bad blocks inode */
 165#define EXT2_ROOT_INO            2      /* Root inode */
 166#define EXT2_BOOT_LOADER_INO     5      /* Boot loader inode */
 167#define EXT2_UNDEL_DIR_INO       6      /* Undelete directory inode */
 168
 169/* First non-reserved inode for old ext2 filesystems */
 170#define EXT2_GOOD_OLD_FIRST_INO 11
 171
 172static inline struct ext2_sb_info *EXT2_SB(struct super_block *sb)
 173{
 174        return sb->s_fs_info;
 175}
 176
 177/*
 178 * Macro-instructions used to manage several block sizes
 179 */
 180#define EXT2_MIN_BLOCK_SIZE             1024
 181#define EXT2_MAX_BLOCK_SIZE             4096
 182#define EXT2_MIN_BLOCK_LOG_SIZE           10
 183#define EXT2_BLOCK_SIZE(s)              ((s)->s_blocksize)
 184#define EXT2_ADDR_PER_BLOCK(s)          (EXT2_BLOCK_SIZE(s) / sizeof (__u32))
 185#define EXT2_BLOCK_SIZE_BITS(s)         ((s)->s_blocksize_bits)
 186#define EXT2_ADDR_PER_BLOCK_BITS(s)     (EXT2_SB(s)->s_addr_per_block_bits)
 187#define EXT2_INODE_SIZE(s)              (EXT2_SB(s)->s_inode_size)
 188#define EXT2_FIRST_INO(s)               (EXT2_SB(s)->s_first_ino)
 189
 190/*
 191 * Macro-instructions used to manage fragments
 192 */
 193#define EXT2_MIN_FRAG_SIZE              1024
 194#define EXT2_MAX_FRAG_SIZE              4096
 195#define EXT2_MIN_FRAG_LOG_SIZE            10
 196#define EXT2_FRAG_SIZE(s)               (EXT2_SB(s)->s_frag_size)
 197#define EXT2_FRAGS_PER_BLOCK(s)         (EXT2_SB(s)->s_frags_per_block)
 198
 199/*
 200 * Structure of a blocks group descriptor
 201 */
 202struct ext2_group_desc
 203{
 204        __le32  bg_block_bitmap;                /* Blocks bitmap block */
 205        __le32  bg_inode_bitmap;                /* Inodes bitmap block */
 206        __le32  bg_inode_table;         /* Inodes table block */
 207        __le16  bg_free_blocks_count;   /* Free blocks count */
 208        __le16  bg_free_inodes_count;   /* Free inodes count */
 209        __le16  bg_used_dirs_count;     /* Directories count */
 210        __le16  bg_pad;
 211        __le32  bg_reserved[3];
 212};
 213
 214/*
 215 * Macro-instructions used to manage group descriptors
 216 */
 217#define EXT2_BLOCKS_PER_GROUP(s)        (EXT2_SB(s)->s_blocks_per_group)
 218#define EXT2_DESC_PER_BLOCK(s)          (EXT2_SB(s)->s_desc_per_block)
 219#define EXT2_INODES_PER_GROUP(s)        (EXT2_SB(s)->s_inodes_per_group)
 220#define EXT2_DESC_PER_BLOCK_BITS(s)     (EXT2_SB(s)->s_desc_per_block_bits)
 221
 222/*
 223 * Constants relative to the data blocks
 224 */
 225#define EXT2_NDIR_BLOCKS                12
 226#define EXT2_IND_BLOCK                  EXT2_NDIR_BLOCKS
 227#define EXT2_DIND_BLOCK                 (EXT2_IND_BLOCK + 1)
 228#define EXT2_TIND_BLOCK                 (EXT2_DIND_BLOCK + 1)
 229#define EXT2_N_BLOCKS                   (EXT2_TIND_BLOCK + 1)
 230
 231/*
 232 * Inode flags (GETFLAGS/SETFLAGS)
 233 */
 234#define EXT2_SECRM_FL                   FS_SECRM_FL     /* Secure deletion */
 235#define EXT2_UNRM_FL                    FS_UNRM_FL      /* Undelete */
 236#define EXT2_COMPR_FL                   FS_COMPR_FL     /* Compress file */
 237#define EXT2_SYNC_FL                    FS_SYNC_FL      /* Synchronous updates */
 238#define EXT2_IMMUTABLE_FL               FS_IMMUTABLE_FL /* Immutable file */
 239#define EXT2_APPEND_FL                  FS_APPEND_FL    /* writes to file may only append */
 240#define EXT2_NODUMP_FL                  FS_NODUMP_FL    /* do not dump file */
 241#define EXT2_NOATIME_FL                 FS_NOATIME_FL   /* do not update atime */
 242/* Reserved for compression usage... */
 243#define EXT2_DIRTY_FL                   FS_DIRTY_FL
 244#define EXT2_COMPRBLK_FL                FS_COMPRBLK_FL  /* One or more compressed clusters */
 245#define EXT2_NOCOMP_FL                  FS_NOCOMP_FL    /* Don't compress */
 246#define EXT2_ECOMPR_FL                  FS_ECOMPR_FL    /* Compression error */
 247/* End compression flags --- maybe not all used */      
 248#define EXT2_BTREE_FL                   FS_BTREE_FL     /* btree format dir */
 249#define EXT2_INDEX_FL                   FS_INDEX_FL     /* hash-indexed directory */
 250#define EXT2_IMAGIC_FL                  FS_IMAGIC_FL    /* AFS directory */
 251#define EXT2_JOURNAL_DATA_FL            FS_JOURNAL_DATA_FL /* Reserved for ext3 */
 252#define EXT2_NOTAIL_FL                  FS_NOTAIL_FL    /* file tail should not be merged */
 253#define EXT2_DIRSYNC_FL                 FS_DIRSYNC_FL   /* dirsync behaviour (directories only) */
 254#define EXT2_TOPDIR_FL                  FS_TOPDIR_FL    /* Top of directory hierarchies*/
 255#define EXT2_RESERVED_FL                FS_RESERVED_FL  /* reserved for ext2 lib */
 256
 257#define EXT2_FL_USER_VISIBLE            FS_FL_USER_VISIBLE      /* User visible flags */
 258#define EXT2_FL_USER_MODIFIABLE         FS_FL_USER_MODIFIABLE   /* User modifiable flags */
 259
 260/* Flags that should be inherited by new inodes from their parent. */
 261#define EXT2_FL_INHERITED (EXT2_SECRM_FL | EXT2_UNRM_FL | EXT2_COMPR_FL |\
 262                           EXT2_SYNC_FL | EXT2_NODUMP_FL |\
 263                           EXT2_NOATIME_FL | EXT2_COMPRBLK_FL |\
 264                           EXT2_NOCOMP_FL | EXT2_JOURNAL_DATA_FL |\
 265                           EXT2_NOTAIL_FL | EXT2_DIRSYNC_FL)
 266
 267/* Flags that are appropriate for regular files (all but dir-specific ones). */
 268#define EXT2_REG_FLMASK (~(EXT2_DIRSYNC_FL | EXT2_TOPDIR_FL))
 269
 270/* Flags that are appropriate for non-directories/regular files. */
 271#define EXT2_OTHER_FLMASK (EXT2_NODUMP_FL | EXT2_NOATIME_FL)
 272
 273/* Mask out flags that are inappropriate for the given type of inode. */
 274static inline __u32 ext2_mask_flags(umode_t mode, __u32 flags)
 275{
 276        if (S_ISDIR(mode))
 277                return flags;
 278        else if (S_ISREG(mode))
 279                return flags & EXT2_REG_FLMASK;
 280        else
 281                return flags & EXT2_OTHER_FLMASK;
 282}
 283
 284/*
 285 * ioctl commands
 286 */
 287#define EXT2_IOC_GETVERSION             FS_IOC_GETVERSION
 288#define EXT2_IOC_SETVERSION             FS_IOC_SETVERSION
 289#define EXT2_IOC_GETRSVSZ               _IOR('f', 5, long)
 290#define EXT2_IOC_SETRSVSZ               _IOW('f', 6, long)
 291
 292/*
 293 * ioctl commands in 32 bit emulation
 294 */
 295#define EXT2_IOC32_GETVERSION           FS_IOC32_GETVERSION
 296#define EXT2_IOC32_SETVERSION           FS_IOC32_SETVERSION
 297
 298/*
 299 * Structure of an inode on the disk
 300 */
 301struct ext2_inode {
 302        __le16  i_mode;         /* File mode */
 303        __le16  i_uid;          /* Low 16 bits of Owner Uid */
 304        __le32  i_size;         /* Size in bytes */
 305        __le32  i_atime;        /* Access time */
 306        __le32  i_ctime;        /* Creation time */
 307        __le32  i_mtime;        /* Modification time */
 308        __le32  i_dtime;        /* Deletion Time */
 309        __le16  i_gid;          /* Low 16 bits of Group Id */
 310        __le16  i_links_count;  /* Links count */
 311        __le32  i_blocks;       /* Blocks count */
 312        __le32  i_flags;        /* File flags */
 313        union {
 314                struct {
 315                        __le32  l_i_reserved1;
 316                } linux1;
 317                struct {
 318                        __le32  h_i_translator;
 319                } hurd1;
 320                struct {
 321                        __le32  m_i_reserved1;
 322                } masix1;
 323        } osd1;                         /* OS dependent 1 */
 324        __le32  i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
 325        __le32  i_generation;   /* File version (for NFS) */
 326        __le32  i_file_acl;     /* File ACL */
 327        __le32  i_dir_acl;      /* Directory ACL */
 328        __le32  i_faddr;        /* Fragment address */
 329        union {
 330                struct {
 331                        __u8    l_i_frag;       /* Fragment number */
 332                        __u8    l_i_fsize;      /* Fragment size */
 333                        __u16   i_pad1;
 334                        __le16  l_i_uid_high;   /* these 2 fields    */
 335                        __le16  l_i_gid_high;   /* were reserved2[0] */
 336                        __u32   l_i_reserved2;
 337                } linux2;
 338                struct {
 339                        __u8    h_i_frag;       /* Fragment number */
 340                        __u8    h_i_fsize;      /* Fragment size */
 341                        __le16  h_i_mode_high;
 342                        __le16  h_i_uid_high;
 343                        __le16  h_i_gid_high;
 344                        __le32  h_i_author;
 345                } hurd2;
 346                struct {
 347                        __u8    m_i_frag;       /* Fragment number */
 348                        __u8    m_i_fsize;      /* Fragment size */
 349                        __u16   m_pad1;
 350                        __u32   m_i_reserved2[2];
 351                } masix2;
 352        } osd2;                         /* OS dependent 2 */
 353};
 354
 355#define i_size_high     i_dir_acl
 356
 357#define i_reserved1     osd1.linux1.l_i_reserved1
 358#define i_frag          osd2.linux2.l_i_frag
 359#define i_fsize         osd2.linux2.l_i_fsize
 360#define i_uid_low       i_uid
 361#define i_gid_low       i_gid
 362#define i_uid_high      osd2.linux2.l_i_uid_high
 363#define i_gid_high      osd2.linux2.l_i_gid_high
 364#define i_reserved2     osd2.linux2.l_i_reserved2
 365
 366/*
 367 * File system states
 368 */
 369#define EXT2_VALID_FS                   0x0001  /* Unmounted cleanly */
 370#define EXT2_ERROR_FS                   0x0002  /* Errors detected */
 371#define EFSCORRUPTED                    EUCLEAN /* Filesystem is corrupted */
 372
 373/*
 374 * Mount flags
 375 */
 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#define EXT2_MOUNT_DAX                  0x100000  /* Direct Access */
 392
 393
 394#define clear_opt(o, opt)               o &= ~EXT2_MOUNT_##opt
 395#define set_opt(o, opt)                 o |= EXT2_MOUNT_##opt
 396#define test_opt(sb, opt)               (EXT2_SB(sb)->s_mount_opt & \
 397                                         EXT2_MOUNT_##opt)
 398/*
 399 * Maximal mount counts between two filesystem checks
 400 */
 401#define EXT2_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
 402#define EXT2_DFL_CHECKINTERVAL          0       /* Don't use interval check */
 403
 404/*
 405 * Behaviour when detecting errors
 406 */
 407#define EXT2_ERRORS_CONTINUE            1       /* Continue execution */
 408#define EXT2_ERRORS_RO                  2       /* Remount fs read-only */
 409#define EXT2_ERRORS_PANIC               3       /* Panic */
 410#define EXT2_ERRORS_DEFAULT             EXT2_ERRORS_CONTINUE
 411
 412/*
 413 * Structure of the super block
 414 */
 415struct ext2_super_block {
 416        __le32  s_inodes_count;         /* Inodes count */
 417        __le32  s_blocks_count;         /* Blocks count */
 418        __le32  s_r_blocks_count;       /* Reserved blocks count */
 419        __le32  s_free_blocks_count;    /* Free blocks count */
 420        __le32  s_free_inodes_count;    /* Free inodes count */
 421        __le32  s_first_data_block;     /* First Data Block */
 422        __le32  s_log_block_size;       /* Block size */
 423        __le32  s_log_frag_size;        /* Fragment size */
 424        __le32  s_blocks_per_group;     /* # Blocks per group */
 425        __le32  s_frags_per_group;      /* # Fragments per group */
 426        __le32  s_inodes_per_group;     /* # Inodes per group */
 427        __le32  s_mtime;                /* Mount time */
 428        __le32  s_wtime;                /* Write time */
 429        __le16  s_mnt_count;            /* Mount count */
 430        __le16  s_max_mnt_count;        /* Maximal mount count */
 431        __le16  s_magic;                /* Magic signature */
 432        __le16  s_state;                /* File system state */
 433        __le16  s_errors;               /* Behaviour when detecting errors */
 434        __le16  s_minor_rev_level;      /* minor revision level */
 435        __le32  s_lastcheck;            /* time of last check */
 436        __le32  s_checkinterval;        /* max. time between checks */
 437        __le32  s_creator_os;           /* OS */
 438        __le32  s_rev_level;            /* Revision level */
 439        __le16  s_def_resuid;           /* Default uid for reserved blocks */
 440        __le16  s_def_resgid;           /* Default gid for reserved blocks */
 441        /*
 442         * These fields are for EXT2_DYNAMIC_REV superblocks only.
 443         *
 444         * Note: the difference between the compatible feature set and
 445         * the incompatible feature set is that if there is a bit set
 446         * in the incompatible feature set that the kernel doesn't
 447         * know about, it should refuse to mount the filesystem.
 448         * 
 449         * e2fsck's requirements are more strict; if it doesn't know
 450         * about a feature in either the compatible or incompatible
 451         * feature set, it must abort and not try to meddle with
 452         * things it doesn't understand...
 453         */
 454        __le32  s_first_ino;            /* First non-reserved inode */
 455        __le16   s_inode_size;          /* size of inode structure */
 456        __le16  s_block_group_nr;       /* block group # of this superblock */
 457        __le32  s_feature_compat;       /* compatible feature set */
 458        __le32  s_feature_incompat;     /* incompatible feature set */
 459        __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
 460        __u8    s_uuid[16];             /* 128-bit uuid for volume */
 461        char    s_volume_name[16];      /* volume name */
 462        char    s_last_mounted[64];     /* directory where last mounted */
 463        __le32  s_algorithm_usage_bitmap; /* For compression */
 464        /*
 465         * Performance hints.  Directory preallocation should only
 466         * happen if the EXT2_COMPAT_PREALLOC flag is on.
 467         */
 468        __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
 469        __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
 470        __u16   s_padding1;
 471        /*
 472         * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set.
 473         */
 474        __u8    s_journal_uuid[16];     /* uuid of journal superblock */
 475        __u32   s_journal_inum;         /* inode number of journal file */
 476        __u32   s_journal_dev;          /* device number of journal file */
 477        __u32   s_last_orphan;          /* start of list of inodes to delete */
 478        __u32   s_hash_seed[4];         /* HTREE hash seed */
 479        __u8    s_def_hash_version;     /* Default hash version to use */
 480        __u8    s_reserved_char_pad;
 481        __u16   s_reserved_word_pad;
 482        __le32  s_default_mount_opts;
 483        __le32  s_first_meta_bg;        /* First metablock block group */
 484        __u32   s_reserved[190];        /* Padding to the end of the block */
 485};
 486
 487/*
 488 * Codes for operating systems
 489 */
 490#define EXT2_OS_LINUX           0
 491#define EXT2_OS_HURD            1
 492#define EXT2_OS_MASIX           2
 493#define EXT2_OS_FREEBSD         3
 494#define EXT2_OS_LITES           4
 495
 496/*
 497 * Revision levels
 498 */
 499#define EXT2_GOOD_OLD_REV       0       /* The good old (original) format */
 500#define EXT2_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
 501
 502#define EXT2_CURRENT_REV        EXT2_GOOD_OLD_REV
 503#define EXT2_MAX_SUPP_REV       EXT2_DYNAMIC_REV
 504
 505#define EXT2_GOOD_OLD_INODE_SIZE 128
 506
 507/*
 508 * Feature set definitions
 509 */
 510
 511#define EXT2_HAS_COMPAT_FEATURE(sb,mask)                        \
 512        ( EXT2_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) )
 513#define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
 514        ( EXT2_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) )
 515#define EXT2_HAS_INCOMPAT_FEATURE(sb,mask)                      \
 516        ( EXT2_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) )
 517#define EXT2_SET_COMPAT_FEATURE(sb,mask)                        \
 518        EXT2_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
 519#define EXT2_SET_RO_COMPAT_FEATURE(sb,mask)                     \
 520        EXT2_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
 521#define EXT2_SET_INCOMPAT_FEATURE(sb,mask)                      \
 522        EXT2_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
 523#define EXT2_CLEAR_COMPAT_FEATURE(sb,mask)                      \
 524        EXT2_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
 525#define EXT2_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
 526        EXT2_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
 527#define EXT2_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
 528        EXT2_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
 529
 530#define EXT2_FEATURE_COMPAT_DIR_PREALLOC        0x0001
 531#define EXT2_FEATURE_COMPAT_IMAGIC_INODES       0x0002
 532#define EXT3_FEATURE_COMPAT_HAS_JOURNAL         0x0004
 533#define EXT2_FEATURE_COMPAT_EXT_ATTR            0x0008
 534#define EXT2_FEATURE_COMPAT_RESIZE_INO          0x0010
 535#define EXT2_FEATURE_COMPAT_DIR_INDEX           0x0020
 536#define EXT2_FEATURE_COMPAT_ANY                 0xffffffff
 537
 538#define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
 539#define EXT2_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
 540#define EXT2_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
 541#define EXT2_FEATURE_RO_COMPAT_ANY              0xffffffff
 542
 543#define EXT2_FEATURE_INCOMPAT_COMPRESSION       0x0001
 544#define EXT2_FEATURE_INCOMPAT_FILETYPE          0x0002
 545#define EXT3_FEATURE_INCOMPAT_RECOVER           0x0004
 546#define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008
 547#define EXT2_FEATURE_INCOMPAT_META_BG           0x0010
 548#define EXT2_FEATURE_INCOMPAT_ANY               0xffffffff
 549
 550#define EXT2_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
 551#define EXT2_FEATURE_INCOMPAT_SUPP      (EXT2_FEATURE_INCOMPAT_FILETYPE| \
 552                                         EXT2_FEATURE_INCOMPAT_META_BG)
 553#define EXT2_FEATURE_RO_COMPAT_SUPP     (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
 554                                         EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
 555                                         EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
 556#define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED      ~EXT2_FEATURE_RO_COMPAT_SUPP
 557#define EXT2_FEATURE_INCOMPAT_UNSUPPORTED       ~EXT2_FEATURE_INCOMPAT_SUPP
 558
 559/*
 560 * Default values for user and/or group using reserved blocks
 561 */
 562#define EXT2_DEF_RESUID         0
 563#define EXT2_DEF_RESGID         0
 564
 565/*
 566 * Default mount options
 567 */
 568#define EXT2_DEFM_DEBUG         0x0001
 569#define EXT2_DEFM_BSDGROUPS     0x0002
 570#define EXT2_DEFM_XATTR_USER    0x0004
 571#define EXT2_DEFM_ACL           0x0008
 572#define EXT2_DEFM_UID16         0x0010
 573    /* Not used by ext2, but reserved for use by ext3 */
 574#define EXT3_DEFM_JMODE         0x0060 
 575#define EXT3_DEFM_JMODE_DATA    0x0020
 576#define EXT3_DEFM_JMODE_ORDERED 0x0040
 577#define EXT3_DEFM_JMODE_WBACK   0x0060
 578
 579/*
 580 * Structure of a directory entry
 581 */
 582
 583struct ext2_dir_entry {
 584        __le32  inode;                  /* Inode number */
 585        __le16  rec_len;                /* Directory entry length */
 586        __le16  name_len;               /* Name length */
 587        char    name[];                 /* File name, up to EXT2_NAME_LEN */
 588};
 589
 590/*
 591 * The new version of the directory entry.  Since EXT2 structures are
 592 * stored in intel byte order, and the name_len field could never be
 593 * bigger than 255 chars, it's safe to reclaim the extra byte for the
 594 * file_type field.
 595 */
 596struct ext2_dir_entry_2 {
 597        __le32  inode;                  /* Inode number */
 598        __le16  rec_len;                /* Directory entry length */
 599        __u8    name_len;               /* Name length */
 600        __u8    file_type;
 601        char    name[];                 /* File name, up to EXT2_NAME_LEN */
 602};
 603
 604/*
 605 * EXT2_DIR_PAD defines the directory entries boundaries
 606 *
 607 * NOTE: It must be a multiple of 4
 608 */
 609#define EXT2_DIR_PAD                    4
 610#define EXT2_DIR_ROUND                  (EXT2_DIR_PAD - 1)
 611#define EXT2_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT2_DIR_ROUND) & \
 612                                         ~EXT2_DIR_ROUND)
 613#define EXT2_MAX_REC_LEN                ((1<<16)-1)
 614
 615static inline void verify_offsets(void)
 616{
 617#define A(x,y) BUILD_BUG_ON(x != offsetof(struct ext2_super_block, y));
 618        A(EXT2_SB_MAGIC_OFFSET, s_magic);
 619        A(EXT2_SB_BLOCKS_OFFSET, s_blocks_count);
 620        A(EXT2_SB_BSIZE_OFFSET, s_log_block_size);
 621#undef A
 622}
 623
 624/*
 625 * ext2 mount options
 626 */
 627struct ext2_mount_options {
 628        unsigned long s_mount_opt;
 629        kuid_t s_resuid;
 630        kgid_t s_resgid;
 631};
 632
 633/*
 634 * second extended file system inode data in memory
 635 */
 636struct ext2_inode_info {
 637        __le32  i_data[15];
 638        __u32   i_flags;
 639        __u32   i_faddr;
 640        __u8    i_frag_no;
 641        __u8    i_frag_size;
 642        __u16   i_state;
 643        __u32   i_file_acl;
 644        __u32   i_dir_acl;
 645        __u32   i_dtime;
 646
 647        /*
 648         * i_block_group is the number of the block group which contains
 649         * this file's inode.  Constant across the lifetime of the inode,
 650         * it is used for making block allocation decisions - we try to
 651         * place a file's data blocks near its inode block, and new inodes
 652         * near to their parent directory's inode.
 653         */
 654        __u32   i_block_group;
 655
 656        /* block reservation info */
 657        struct ext2_block_alloc_info *i_block_alloc_info;
 658
 659        __u32   i_dir_start_lookup;
 660#ifdef CONFIG_EXT2_FS_XATTR
 661        /*
 662         * Extended attributes can be read independently of the main file
 663         * data. Taking i_mutex even when reading would cause contention
 664         * between readers of EAs and writers of regular file data, so
 665         * instead we synchronize on xattr_sem when reading or changing
 666         * EAs.
 667         */
 668        struct rw_semaphore xattr_sem;
 669#endif
 670        rwlock_t i_meta_lock;
 671
 672        /*
 673         * truncate_mutex is for serialising ext2_truncate() against
 674         * ext2_getblock().  It also protects the internals of the inode's
 675         * reservation data structures: ext2_reserve_window and
 676         * ext2_reserve_window_node.
 677         */
 678        struct mutex truncate_mutex;
 679        struct inode    vfs_inode;
 680        struct list_head i_orphan;      /* unlinked but open inodes */
 681#ifdef CONFIG_QUOTA
 682        struct dquot *i_dquot[MAXQUOTAS];
 683#endif
 684};
 685
 686/*
 687 * Inode dynamic state flags
 688 */
 689#define EXT2_STATE_NEW                  0x00000001 /* inode is newly created */
 690
 691
 692/*
 693 * Function prototypes
 694 */
 695
 696/*
 697 * Ok, these declarations are also in <linux/kernel.h> but none of the
 698 * ext2 source programs needs to include it so they are duplicated here.
 699 */
 700
 701static inline struct ext2_inode_info *EXT2_I(struct inode *inode)
 702{
 703        return container_of(inode, struct ext2_inode_info, vfs_inode);
 704}
 705
 706/* balloc.c */
 707extern int ext2_bg_has_super(struct super_block *sb, int group);
 708extern unsigned long ext2_bg_num_gdb(struct super_block *sb, int group);
 709extern ext2_fsblk_t ext2_new_block(struct inode *, unsigned long, int *);
 710extern ext2_fsblk_t ext2_new_blocks(struct inode *, unsigned long,
 711                                unsigned long *, int *);
 712extern int ext2_data_block_valid(struct ext2_sb_info *sbi, ext2_fsblk_t start_blk,
 713                                 unsigned int count);
 714extern void ext2_free_blocks (struct inode *, unsigned long,
 715                              unsigned long);
 716extern unsigned long ext2_count_free_blocks (struct super_block *);
 717extern unsigned long ext2_count_dirs (struct super_block *);
 718extern struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb,
 719                                                    unsigned int block_group,
 720                                                    struct buffer_head ** bh);
 721extern void ext2_discard_reservation (struct inode *);
 722extern int ext2_should_retry_alloc(struct super_block *sb, int *retries);
 723extern void ext2_init_block_alloc_info(struct inode *);
 724extern void ext2_rsv_window_add(struct super_block *sb, struct ext2_reserve_window_node *rsv);
 725
 726/* dir.c */
 727extern int ext2_add_link (struct dentry *, struct inode *);
 728extern int ext2_inode_by_name(struct inode *dir,
 729                              const struct qstr *child, ino_t *ino);
 730extern int ext2_make_empty(struct inode *, struct inode *);
 731extern struct ext2_dir_entry_2 *ext2_find_entry(struct inode *, const struct qstr *,
 732                                                struct page **, void **res_page_addr);
 733extern int ext2_delete_entry(struct ext2_dir_entry_2 *dir, struct page *page,
 734                             char *kaddr);
 735extern int ext2_empty_dir (struct inode *);
 736extern struct ext2_dir_entry_2 *ext2_dotdot(struct inode *dir, struct page **p, void **pa);
 737extern void ext2_set_link(struct inode *, struct ext2_dir_entry_2 *, struct page *, void *,
 738                          struct inode *, int);
 739static inline void ext2_put_page(struct page *page, void *page_addr)
 740{
 741        kunmap_local(page_addr);
 742        put_page(page);
 743}
 744
 745/* ialloc.c */
 746extern struct inode * ext2_new_inode (struct inode *, umode_t, const struct qstr *);
 747extern void ext2_free_inode (struct inode *);
 748extern unsigned long ext2_count_free_inodes (struct super_block *);
 749extern unsigned long ext2_count_free (struct buffer_head *, unsigned);
 750
 751/* inode.c */
 752extern struct inode *ext2_iget (struct super_block *, unsigned long);
 753extern int ext2_write_inode (struct inode *, struct writeback_control *);
 754extern void ext2_evict_inode(struct inode *);
 755extern int ext2_get_block(struct inode *, sector_t, struct buffer_head *, int);
 756extern int ext2_setattr (struct user_namespace *, struct dentry *, struct iattr *);
 757extern int ext2_getattr (struct user_namespace *, const struct path *,
 758                         struct kstat *, u32, unsigned int);
 759extern void ext2_set_inode_flags(struct inode *inode);
 760extern int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 761                       u64 start, u64 len);
 762
 763/* ioctl.c */
 764extern int ext2_fileattr_get(struct dentry *dentry, struct fileattr *fa);
 765extern int ext2_fileattr_set(struct user_namespace *mnt_userns,
 766                             struct dentry *dentry, struct fileattr *fa);
 767extern long ext2_ioctl(struct file *, unsigned int, unsigned long);
 768extern long ext2_compat_ioctl(struct file *, unsigned int, unsigned long);
 769
 770/* namei.c */
 771struct dentry *ext2_get_parent(struct dentry *child);
 772
 773/* super.c */
 774extern __printf(3, 4)
 775void ext2_error(struct super_block *, const char *, const char *, ...);
 776extern __printf(3, 4)
 777void ext2_msg(struct super_block *, const char *, const char *, ...);
 778extern void ext2_update_dynamic_rev (struct super_block *sb);
 779extern void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
 780                            int wait);
 781
 782/*
 783 * Inodes and files operations
 784 */
 785
 786/* dir.c */
 787extern const struct file_operations ext2_dir_operations;
 788
 789/* file.c */
 790extern int ext2_fsync(struct file *file, loff_t start, loff_t end,
 791                      int datasync);
 792extern const struct inode_operations ext2_file_inode_operations;
 793extern const struct file_operations ext2_file_operations;
 794
 795/* inode.c */
 796extern void ext2_set_file_ops(struct inode *inode);
 797extern const struct address_space_operations ext2_aops;
 798extern const struct address_space_operations ext2_nobh_aops;
 799extern const struct iomap_ops ext2_iomap_ops;
 800
 801/* namei.c */
 802extern const struct inode_operations ext2_dir_inode_operations;
 803extern const struct inode_operations ext2_special_inode_operations;
 804
 805/* symlink.c */
 806extern const struct inode_operations ext2_fast_symlink_inode_operations;
 807extern const struct inode_operations ext2_symlink_inode_operations;
 808
 809static inline ext2_fsblk_t
 810ext2_group_first_block_no(struct super_block *sb, unsigned long group_no)
 811{
 812        return group_no * (ext2_fsblk_t)EXT2_BLOCKS_PER_GROUP(sb) +
 813                le32_to_cpu(EXT2_SB(sb)->s_es->s_first_data_block);
 814}
 815
 816static inline ext2_fsblk_t
 817ext2_group_last_block_no(struct super_block *sb, unsigned long group_no)
 818{
 819        struct ext2_sb_info *sbi = EXT2_SB(sb);
 820
 821        if (group_no == sbi->s_groups_count - 1)
 822                return le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 823        else
 824                return ext2_group_first_block_no(sb, group_no) +
 825                        EXT2_BLOCKS_PER_GROUP(sb) - 1;
 826}
 827
 828#define ext2_set_bit    __test_and_set_bit_le
 829#define ext2_clear_bit  __test_and_clear_bit_le
 830#define ext2_test_bit   test_bit_le
 831#define ext2_find_first_zero_bit        find_first_zero_bit_le
 832#define ext2_find_next_zero_bit         find_next_zero_bit_le
 833