linux/fs/ext4/ext4.h
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   1/*
   2 *  ext4.h
   3 *
   4 * Copyright (C) 1992, 1993, 1994, 1995
   5 * Remy Card (card@masi.ibp.fr)
   6 * Laboratoire MASI - Institut Blaise Pascal
   7 * Universite Pierre et Marie Curie (Paris VI)
   8 *
   9 *  from
  10 *
  11 *  linux/include/linux/minix_fs.h
  12 *
  13 *  Copyright (C) 1991, 1992  Linus Torvalds
  14 */
  15
  16#ifndef _EXT4_H
  17#define _EXT4_H
  18
  19#include <linux/types.h>
  20#include <linux/blkdev.h>
  21#include <linux/magic.h>
  22#include <linux/jbd2.h>
  23#include <linux/quota.h>
  24#include <linux/rwsem.h>
  25#include <linux/rbtree.h>
  26#include <linux/seqlock.h>
  27#include <linux/mutex.h>
  28#include <linux/timer.h>
  29#include <linux/wait.h>
  30#include <linux/blockgroup_lock.h>
  31#include <linux/percpu_counter.h>
  32#include <crypto/hash.h>
  33#ifdef __KERNEL__
  34#include <linux/compat.h>
  35#endif
  36
  37/*
  38 * The fourth extended filesystem constants/structures
  39 */
  40
  41/*
  42 * Define EXT4FS_DEBUG to produce debug messages
  43 */
  44#undef EXT4FS_DEBUG
  45
  46/*
  47 * Debug code
  48 */
  49#ifdef EXT4FS_DEBUG
  50#define ext4_debug(f, a...)                                             \
  51        do {                                                            \
  52                printk(KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:",        \
  53                        __FILE__, __LINE__, __func__);                  \
  54                printk(KERN_DEBUG f, ## a);                             \
  55        } while (0)
  56#else
  57#define ext4_debug(fmt, ...)    no_printk(fmt, ##__VA_ARGS__)
  58#endif
  59
  60#define EXT4_ERROR_INODE(inode, fmt, a...) \
  61        ext4_error_inode((inode), __func__, __LINE__, 0, (fmt), ## a)
  62
  63#define EXT4_ERROR_INODE_BLOCK(inode, block, fmt, a...)                 \
  64        ext4_error_inode((inode), __func__, __LINE__, (block), (fmt), ## a)
  65
  66#define EXT4_ERROR_FILE(file, block, fmt, a...)                         \
  67        ext4_error_file((file), __func__, __LINE__, (block), (fmt), ## a)
  68
  69/* data type for block offset of block group */
  70typedef int ext4_grpblk_t;
  71
  72/* data type for filesystem-wide blocks number */
  73typedef unsigned long long ext4_fsblk_t;
  74
  75/* data type for file logical block number */
  76typedef __u32 ext4_lblk_t;
  77
  78/* data type for block group number */
  79typedef unsigned int ext4_group_t;
  80
  81/*
  82 * Flags used in mballoc's allocation_context flags field.
  83 *
  84 * Also used to show what's going on for debugging purposes when the
  85 * flag field is exported via the traceport interface
  86 */
  87
  88/* prefer goal again. length */
  89#define EXT4_MB_HINT_MERGE              0x0001
  90/* blocks already reserved */
  91#define EXT4_MB_HINT_RESERVED           0x0002
  92/* metadata is being allocated */
  93#define EXT4_MB_HINT_METADATA           0x0004
  94/* first blocks in the file */
  95#define EXT4_MB_HINT_FIRST              0x0008
  96/* search for the best chunk */
  97#define EXT4_MB_HINT_BEST               0x0010
  98/* data is being allocated */
  99#define EXT4_MB_HINT_DATA               0x0020
 100/* don't preallocate (for tails) */
 101#define EXT4_MB_HINT_NOPREALLOC         0x0040
 102/* allocate for locality group */
 103#define EXT4_MB_HINT_GROUP_ALLOC        0x0080
 104/* allocate goal blocks or none */
 105#define EXT4_MB_HINT_GOAL_ONLY          0x0100
 106/* goal is meaningful */
 107#define EXT4_MB_HINT_TRY_GOAL           0x0200
 108/* blocks already pre-reserved by delayed allocation */
 109#define EXT4_MB_DELALLOC_RESERVED       0x0400
 110/* We are doing stream allocation */
 111#define EXT4_MB_STREAM_ALLOC            0x0800
 112/* Use reserved root blocks if needed */
 113#define EXT4_MB_USE_ROOT_BLOCKS         0x1000
 114
 115struct ext4_allocation_request {
 116        /* target inode for block we're allocating */
 117        struct inode *inode;
 118        /* how many blocks we want to allocate */
 119        unsigned int len;
 120        /* logical block in target inode */
 121        ext4_lblk_t logical;
 122        /* the closest logical allocated block to the left */
 123        ext4_lblk_t lleft;
 124        /* the closest logical allocated block to the right */
 125        ext4_lblk_t lright;
 126        /* phys. target (a hint) */
 127        ext4_fsblk_t goal;
 128        /* phys. block for the closest logical allocated block to the left */
 129        ext4_fsblk_t pleft;
 130        /* phys. block for the closest logical allocated block to the right */
 131        ext4_fsblk_t pright;
 132        /* flags. see above EXT4_MB_HINT_* */
 133        unsigned int flags;
 134};
 135
 136/*
 137 * Logical to physical block mapping, used by ext4_map_blocks()
 138 *
 139 * This structure is used to pass requests into ext4_map_blocks() as
 140 * well as to store the information returned by ext4_map_blocks().  It
 141 * takes less room on the stack than a struct buffer_head.
 142 */
 143#define EXT4_MAP_NEW            (1 << BH_New)
 144#define EXT4_MAP_MAPPED         (1 << BH_Mapped)
 145#define EXT4_MAP_UNWRITTEN      (1 << BH_Unwritten)
 146#define EXT4_MAP_BOUNDARY       (1 << BH_Boundary)
 147#define EXT4_MAP_UNINIT         (1 << BH_Uninit)
 148/* Sometimes (in the bigalloc case, from ext4_da_get_block_prep) the caller of
 149 * ext4_map_blocks wants to know whether or not the underlying cluster has
 150 * already been accounted for. EXT4_MAP_FROM_CLUSTER conveys to the caller that
 151 * the requested mapping was from previously mapped (or delayed allocated)
 152 * cluster. We use BH_AllocFromCluster only for this flag. BH_AllocFromCluster
 153 * should never appear on buffer_head's state flags.
 154 */
 155#define EXT4_MAP_FROM_CLUSTER   (1 << BH_AllocFromCluster)
 156#define EXT4_MAP_FLAGS          (EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
 157                                 EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY |\
 158                                 EXT4_MAP_UNINIT | EXT4_MAP_FROM_CLUSTER)
 159
 160struct ext4_map_blocks {
 161        ext4_fsblk_t m_pblk;
 162        ext4_lblk_t m_lblk;
 163        unsigned int m_len;
 164        unsigned int m_flags;
 165};
 166
 167/*
 168 * For delayed allocation tracking
 169 */
 170struct mpage_da_data {
 171        struct inode *inode;
 172        sector_t b_blocknr;             /* start block number of extent */
 173        size_t b_size;                  /* size of extent */
 174        unsigned long b_state;          /* state of the extent */
 175        unsigned long first_page, next_page;    /* extent of pages */
 176        struct writeback_control *wbc;
 177        int io_done;
 178        int pages_written;
 179        int retval;
 180};
 181
 182/*
 183 * Flags for ext4_io_end->flags
 184 */
 185#define EXT4_IO_END_UNWRITTEN   0x0001
 186#define EXT4_IO_END_ERROR       0x0002
 187#define EXT4_IO_END_QUEUED      0x0004
 188#define EXT4_IO_END_DIRECT      0x0008
 189#define EXT4_IO_END_IN_FSYNC    0x0010
 190
 191struct ext4_io_page {
 192        struct page     *p_page;
 193        atomic_t        p_count;
 194};
 195
 196#define MAX_IO_PAGES 128
 197
 198/*
 199 * For converting uninitialized extents on a work queue.
 200 *
 201 * 'page' is only used from the writepage() path; 'pages' is only used for
 202 * buffered writes; they are used to keep page references until conversion
 203 * takes place.  For AIO/DIO, neither field is filled in.
 204 */
 205typedef struct ext4_io_end {
 206        struct list_head        list;           /* per-file finished IO list */
 207        struct inode            *inode;         /* file being written to */
 208        unsigned int            flag;           /* unwritten or not */
 209        struct page             *page;          /* for writepage() path */
 210        loff_t                  offset;         /* offset in the file */
 211        ssize_t                 size;           /* size of the extent */
 212        struct work_struct      work;           /* data work queue */
 213        struct kiocb            *iocb;          /* iocb struct for AIO */
 214        int                     result;         /* error value for AIO */
 215        int                     num_io_pages;   /* for writepages() */
 216        struct ext4_io_page     *pages[MAX_IO_PAGES]; /* for writepages() */
 217} ext4_io_end_t;
 218
 219struct ext4_io_submit {
 220        int                     io_op;
 221        struct bio              *io_bio;
 222        ext4_io_end_t           *io_end;
 223        struct ext4_io_page     *io_page;
 224        sector_t                io_next_block;
 225};
 226
 227/*
 228 * Special inodes numbers
 229 */
 230#define EXT4_BAD_INO             1      /* Bad blocks inode */
 231#define EXT4_ROOT_INO            2      /* Root inode */
 232#define EXT4_USR_QUOTA_INO       3      /* User quota inode */
 233#define EXT4_GRP_QUOTA_INO       4      /* Group quota inode */
 234#define EXT4_BOOT_LOADER_INO     5      /* Boot loader inode */
 235#define EXT4_UNDEL_DIR_INO       6      /* Undelete directory inode */
 236#define EXT4_RESIZE_INO          7      /* Reserved group descriptors inode */
 237#define EXT4_JOURNAL_INO         8      /* Journal inode */
 238
 239/* First non-reserved inode for old ext4 filesystems */
 240#define EXT4_GOOD_OLD_FIRST_INO 11
 241
 242/*
 243 * Maximal count of links to a file
 244 */
 245#define EXT4_LINK_MAX           65000
 246
 247/*
 248 * Macro-instructions used to manage several block sizes
 249 */
 250#define EXT4_MIN_BLOCK_SIZE             1024
 251#define EXT4_MAX_BLOCK_SIZE             65536
 252#define EXT4_MIN_BLOCK_LOG_SIZE         10
 253#define EXT4_MAX_BLOCK_LOG_SIZE         16
 254#ifdef __KERNEL__
 255# define EXT4_BLOCK_SIZE(s)             ((s)->s_blocksize)
 256#else
 257# define EXT4_BLOCK_SIZE(s)             (EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
 258#endif
 259#define EXT4_ADDR_PER_BLOCK(s)          (EXT4_BLOCK_SIZE(s) / sizeof(__u32))
 260#define EXT4_CLUSTER_SIZE(s)            (EXT4_BLOCK_SIZE(s) << \
 261                                         EXT4_SB(s)->s_cluster_bits)
 262#ifdef __KERNEL__
 263# define EXT4_BLOCK_SIZE_BITS(s)        ((s)->s_blocksize_bits)
 264# define EXT4_CLUSTER_BITS(s)           (EXT4_SB(s)->s_cluster_bits)
 265#else
 266# define EXT4_BLOCK_SIZE_BITS(s)        ((s)->s_log_block_size + 10)
 267#endif
 268#ifdef __KERNEL__
 269#define EXT4_ADDR_PER_BLOCK_BITS(s)     (EXT4_SB(s)->s_addr_per_block_bits)
 270#define EXT4_INODE_SIZE(s)              (EXT4_SB(s)->s_inode_size)
 271#define EXT4_FIRST_INO(s)               (EXT4_SB(s)->s_first_ino)
 272#else
 273#define EXT4_INODE_SIZE(s)      (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
 274                                 EXT4_GOOD_OLD_INODE_SIZE : \
 275                                 (s)->s_inode_size)
 276#define EXT4_FIRST_INO(s)       (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
 277                                 EXT4_GOOD_OLD_FIRST_INO : \
 278                                 (s)->s_first_ino)
 279#endif
 280#define EXT4_BLOCK_ALIGN(size, blkbits)         ALIGN((size), (1 << (blkbits)))
 281
 282/* Translate a block number to a cluster number */
 283#define EXT4_B2C(sbi, blk)      ((blk) >> (sbi)->s_cluster_bits)
 284/* Translate a cluster number to a block number */
 285#define EXT4_C2B(sbi, cluster)  ((cluster) << (sbi)->s_cluster_bits)
 286/* Translate # of blks to # of clusters */
 287#define EXT4_NUM_B2C(sbi, blks) (((blks) + (sbi)->s_cluster_ratio - 1) >> \
 288                                 (sbi)->s_cluster_bits)
 289
 290/*
 291 * Structure of a blocks group descriptor
 292 */
 293struct ext4_group_desc
 294{
 295        __le32  bg_block_bitmap_lo;     /* Blocks bitmap block */
 296        __le32  bg_inode_bitmap_lo;     /* Inodes bitmap block */
 297        __le32  bg_inode_table_lo;      /* Inodes table block */
 298        __le16  bg_free_blocks_count_lo;/* Free blocks count */
 299        __le16  bg_free_inodes_count_lo;/* Free inodes count */
 300        __le16  bg_used_dirs_count_lo;  /* Directories count */
 301        __le16  bg_flags;               /* EXT4_BG_flags (INODE_UNINIT, etc) */
 302        __le32  bg_exclude_bitmap_lo;   /* Exclude bitmap for snapshots */
 303        __le16  bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bbitmap) LE */
 304        __le16  bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+ibitmap) LE */
 305        __le16  bg_itable_unused_lo;    /* Unused inodes count */
 306        __le16  bg_checksum;            /* crc16(sb_uuid+group+desc) */
 307        __le32  bg_block_bitmap_hi;     /* Blocks bitmap block MSB */
 308        __le32  bg_inode_bitmap_hi;     /* Inodes bitmap block MSB */
 309        __le32  bg_inode_table_hi;      /* Inodes table block MSB */
 310        __le16  bg_free_blocks_count_hi;/* Free blocks count MSB */
 311        __le16  bg_free_inodes_count_hi;/* Free inodes count MSB */
 312        __le16  bg_used_dirs_count_hi;  /* Directories count MSB */
 313        __le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
 314        __le32  bg_exclude_bitmap_hi;   /* Exclude bitmap block MSB */
 315        __le16  bg_block_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bbitmap) BE */
 316        __le16  bg_inode_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+ibitmap) BE */
 317        __u32   bg_reserved;
 318};
 319
 320#define EXT4_BG_INODE_BITMAP_CSUM_HI_END        \
 321        (offsetof(struct ext4_group_desc, bg_inode_bitmap_csum_hi) + \
 322         sizeof(__le16))
 323#define EXT4_BG_BLOCK_BITMAP_CSUM_HI_END        \
 324        (offsetof(struct ext4_group_desc, bg_block_bitmap_csum_hi) + \
 325         sizeof(__le16))
 326
 327/*
 328 * Structure of a flex block group info
 329 */
 330
 331struct flex_groups {
 332        atomic_t free_inodes;
 333        atomic_t free_clusters;
 334        atomic_t used_dirs;
 335};
 336
 337#define EXT4_BG_INODE_UNINIT    0x0001 /* Inode table/bitmap not in use */
 338#define EXT4_BG_BLOCK_UNINIT    0x0002 /* Block bitmap not in use */
 339#define EXT4_BG_INODE_ZEROED    0x0004 /* On-disk itable initialized to zero */
 340
 341/*
 342 * Macro-instructions used to manage group descriptors
 343 */
 344#define EXT4_MIN_DESC_SIZE              32
 345#define EXT4_MIN_DESC_SIZE_64BIT        64
 346#define EXT4_MAX_DESC_SIZE              EXT4_MIN_BLOCK_SIZE
 347#define EXT4_DESC_SIZE(s)               (EXT4_SB(s)->s_desc_size)
 348#ifdef __KERNEL__
 349# define EXT4_BLOCKS_PER_GROUP(s)       (EXT4_SB(s)->s_blocks_per_group)
 350# define EXT4_CLUSTERS_PER_GROUP(s)     (EXT4_SB(s)->s_clusters_per_group)
 351# define EXT4_DESC_PER_BLOCK(s)         (EXT4_SB(s)->s_desc_per_block)
 352# define EXT4_INODES_PER_GROUP(s)       (EXT4_SB(s)->s_inodes_per_group)
 353# define EXT4_DESC_PER_BLOCK_BITS(s)    (EXT4_SB(s)->s_desc_per_block_bits)
 354#else
 355# define EXT4_BLOCKS_PER_GROUP(s)       ((s)->s_blocks_per_group)
 356# define EXT4_DESC_PER_BLOCK(s)         (EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
 357# define EXT4_INODES_PER_GROUP(s)       ((s)->s_inodes_per_group)
 358#endif
 359
 360/*
 361 * Constants relative to the data blocks
 362 */
 363#define EXT4_NDIR_BLOCKS                12
 364#define EXT4_IND_BLOCK                  EXT4_NDIR_BLOCKS
 365#define EXT4_DIND_BLOCK                 (EXT4_IND_BLOCK + 1)
 366#define EXT4_TIND_BLOCK                 (EXT4_DIND_BLOCK + 1)
 367#define EXT4_N_BLOCKS                   (EXT4_TIND_BLOCK + 1)
 368
 369/*
 370 * Inode flags
 371 */
 372#define EXT4_SECRM_FL                   0x00000001 /* Secure deletion */
 373#define EXT4_UNRM_FL                    0x00000002 /* Undelete */
 374#define EXT4_COMPR_FL                   0x00000004 /* Compress file */
 375#define EXT4_SYNC_FL                    0x00000008 /* Synchronous updates */
 376#define EXT4_IMMUTABLE_FL               0x00000010 /* Immutable file */
 377#define EXT4_APPEND_FL                  0x00000020 /* writes to file may only append */
 378#define EXT4_NODUMP_FL                  0x00000040 /* do not dump file */
 379#define EXT4_NOATIME_FL                 0x00000080 /* do not update atime */
 380/* Reserved for compression usage... */
 381#define EXT4_DIRTY_FL                   0x00000100
 382#define EXT4_COMPRBLK_FL                0x00000200 /* One or more compressed clusters */
 383#define EXT4_NOCOMPR_FL                 0x00000400 /* Don't compress */
 384#define EXT4_ECOMPR_FL                  0x00000800 /* Compression error */
 385/* End compression flags --- maybe not all used */
 386#define EXT4_INDEX_FL                   0x00001000 /* hash-indexed directory */
 387#define EXT4_IMAGIC_FL                  0x00002000 /* AFS directory */
 388#define EXT4_JOURNAL_DATA_FL            0x00004000 /* file data should be journaled */
 389#define EXT4_NOTAIL_FL                  0x00008000 /* file tail should not be merged */
 390#define EXT4_DIRSYNC_FL                 0x00010000 /* dirsync behaviour (directories only) */
 391#define EXT4_TOPDIR_FL                  0x00020000 /* Top of directory hierarchies*/
 392#define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
 393#define EXT4_EXTENTS_FL                 0x00080000 /* Inode uses extents */
 394#define EXT4_EA_INODE_FL                0x00200000 /* Inode used for large EA */
 395#define EXT4_EOFBLOCKS_FL               0x00400000 /* Blocks allocated beyond EOF */
 396#define EXT4_RESERVED_FL                0x80000000 /* reserved for ext4 lib */
 397
 398#define EXT4_FL_USER_VISIBLE            0x004BDFFF /* User visible flags */
 399#define EXT4_FL_USER_MODIFIABLE         0x004B80FF /* User modifiable flags */
 400
 401/* Flags that should be inherited by new inodes from their parent. */
 402#define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
 403                           EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
 404                           EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
 405                           EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
 406
 407/* Flags that are appropriate for regular files (all but dir-specific ones). */
 408#define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
 409
 410/* Flags that are appropriate for non-directories/regular files. */
 411#define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
 412
 413/* Mask out flags that are inappropriate for the given type of inode. */
 414static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
 415{
 416        if (S_ISDIR(mode))
 417                return flags;
 418        else if (S_ISREG(mode))
 419                return flags & EXT4_REG_FLMASK;
 420        else
 421                return flags & EXT4_OTHER_FLMASK;
 422}
 423
 424/*
 425 * Inode flags used for atomic set/get
 426 */
 427enum {
 428        EXT4_INODE_SECRM        = 0,    /* Secure deletion */
 429        EXT4_INODE_UNRM         = 1,    /* Undelete */
 430        EXT4_INODE_COMPR        = 2,    /* Compress file */
 431        EXT4_INODE_SYNC         = 3,    /* Synchronous updates */
 432        EXT4_INODE_IMMUTABLE    = 4,    /* Immutable file */
 433        EXT4_INODE_APPEND       = 5,    /* writes to file may only append */
 434        EXT4_INODE_NODUMP       = 6,    /* do not dump file */
 435        EXT4_INODE_NOATIME      = 7,    /* do not update atime */
 436/* Reserved for compression usage... */
 437        EXT4_INODE_DIRTY        = 8,
 438        EXT4_INODE_COMPRBLK     = 9,    /* One or more compressed clusters */
 439        EXT4_INODE_NOCOMPR      = 10,   /* Don't compress */
 440        EXT4_INODE_ECOMPR       = 11,   /* Compression error */
 441/* End compression flags --- maybe not all used */
 442        EXT4_INODE_INDEX        = 12,   /* hash-indexed directory */
 443        EXT4_INODE_IMAGIC       = 13,   /* AFS directory */
 444        EXT4_INODE_JOURNAL_DATA = 14,   /* file data should be journaled */
 445        EXT4_INODE_NOTAIL       = 15,   /* file tail should not be merged */
 446        EXT4_INODE_DIRSYNC      = 16,   /* dirsync behaviour (directories only) */
 447        EXT4_INODE_TOPDIR       = 17,   /* Top of directory hierarchies*/
 448        EXT4_INODE_HUGE_FILE    = 18,   /* Set to each huge file */
 449        EXT4_INODE_EXTENTS      = 19,   /* Inode uses extents */
 450        EXT4_INODE_EA_INODE     = 21,   /* Inode used for large EA */
 451        EXT4_INODE_EOFBLOCKS    = 22,   /* Blocks allocated beyond EOF */
 452        EXT4_INODE_RESERVED     = 31,   /* reserved for ext4 lib */
 453};
 454
 455#define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1 << EXT4_INODE_##FLAG))
 456#define CHECK_FLAG_VALUE(FLAG) if (!TEST_FLAG_VALUE(FLAG)) { \
 457        printk(KERN_EMERG "EXT4 flag fail: " #FLAG ": %d %d\n", \
 458                EXT4_##FLAG##_FL, EXT4_INODE_##FLAG); BUG_ON(1); }
 459
 460/*
 461 * Since it's pretty easy to mix up bit numbers and hex values, and we
 462 * can't do a compile-time test for ENUM values, we use a run-time
 463 * test to make sure that EXT4_XXX_FL is consistent with respect to
 464 * EXT4_INODE_XXX.  If all is well the printk and BUG_ON will all drop
 465 * out so it won't cost any extra space in the compiled kernel image.
 466 * But it's important that these values are the same, since we are
 467 * using EXT4_INODE_XXX to test for the flag values, but EXT4_XX_FL
 468 * must be consistent with the values of FS_XXX_FL defined in
 469 * include/linux/fs.h and the on-disk values found in ext2, ext3, and
 470 * ext4 filesystems, and of course the values defined in e2fsprogs.
 471 *
 472 * It's not paranoia if the Murphy's Law really *is* out to get you.  :-)
 473 */
 474static inline void ext4_check_flag_values(void)
 475{
 476        CHECK_FLAG_VALUE(SECRM);
 477        CHECK_FLAG_VALUE(UNRM);
 478        CHECK_FLAG_VALUE(COMPR);
 479        CHECK_FLAG_VALUE(SYNC);
 480        CHECK_FLAG_VALUE(IMMUTABLE);
 481        CHECK_FLAG_VALUE(APPEND);
 482        CHECK_FLAG_VALUE(NODUMP);
 483        CHECK_FLAG_VALUE(NOATIME);
 484        CHECK_FLAG_VALUE(DIRTY);
 485        CHECK_FLAG_VALUE(COMPRBLK);
 486        CHECK_FLAG_VALUE(NOCOMPR);
 487        CHECK_FLAG_VALUE(ECOMPR);
 488        CHECK_FLAG_VALUE(INDEX);
 489        CHECK_FLAG_VALUE(IMAGIC);
 490        CHECK_FLAG_VALUE(JOURNAL_DATA);
 491        CHECK_FLAG_VALUE(NOTAIL);
 492        CHECK_FLAG_VALUE(DIRSYNC);
 493        CHECK_FLAG_VALUE(TOPDIR);
 494        CHECK_FLAG_VALUE(HUGE_FILE);
 495        CHECK_FLAG_VALUE(EXTENTS);
 496        CHECK_FLAG_VALUE(EA_INODE);
 497        CHECK_FLAG_VALUE(EOFBLOCKS);
 498        CHECK_FLAG_VALUE(RESERVED);
 499}
 500
 501/* Used to pass group descriptor data when online resize is done */
 502struct ext4_new_group_input {
 503        __u32 group;            /* Group number for this data */
 504        __u64 block_bitmap;     /* Absolute block number of block bitmap */
 505        __u64 inode_bitmap;     /* Absolute block number of inode bitmap */
 506        __u64 inode_table;      /* Absolute block number of inode table start */
 507        __u32 blocks_count;     /* Total number of blocks in this group */
 508        __u16 reserved_blocks;  /* Number of reserved blocks in this group */
 509        __u16 unused;
 510};
 511
 512#if defined(__KERNEL__) && defined(CONFIG_COMPAT)
 513struct compat_ext4_new_group_input {
 514        u32 group;
 515        compat_u64 block_bitmap;
 516        compat_u64 inode_bitmap;
 517        compat_u64 inode_table;
 518        u32 blocks_count;
 519        u16 reserved_blocks;
 520        u16 unused;
 521};
 522#endif
 523
 524/* The struct ext4_new_group_input in kernel space, with free_blocks_count */
 525struct ext4_new_group_data {
 526        __u32 group;
 527        __u64 block_bitmap;
 528        __u64 inode_bitmap;
 529        __u64 inode_table;
 530        __u32 blocks_count;
 531        __u16 reserved_blocks;
 532        __u16 unused;
 533        __u32 free_blocks_count;
 534};
 535
 536/* Indexes used to index group tables in ext4_new_group_data */
 537enum {
 538        BLOCK_BITMAP = 0,       /* block bitmap */
 539        INODE_BITMAP,           /* inode bitmap */
 540        INODE_TABLE,            /* inode tables */
 541        GROUP_TABLE_COUNT,
 542};
 543
 544/*
 545 * Flags used by ext4_map_blocks()
 546 */
 547        /* Allocate any needed blocks and/or convert an unitialized
 548           extent to be an initialized ext4 */
 549#define EXT4_GET_BLOCKS_CREATE                  0x0001
 550        /* Request the creation of an unitialized extent */
 551#define EXT4_GET_BLOCKS_UNINIT_EXT              0x0002
 552#define EXT4_GET_BLOCKS_CREATE_UNINIT_EXT       (EXT4_GET_BLOCKS_UNINIT_EXT|\
 553                                                 EXT4_GET_BLOCKS_CREATE)
 554        /* Caller is from the delayed allocation writeout path,
 555           so set the magic i_delalloc_reserve_flag after taking the
 556           inode allocation semaphore for */
 557#define EXT4_GET_BLOCKS_DELALLOC_RESERVE        0x0004
 558        /* caller is from the direct IO path, request to creation of an
 559        unitialized extents if not allocated, split the uninitialized
 560        extent if blocks has been preallocated already*/
 561#define EXT4_GET_BLOCKS_PRE_IO                  0x0008
 562#define EXT4_GET_BLOCKS_CONVERT                 0x0010
 563#define EXT4_GET_BLOCKS_IO_CREATE_EXT           (EXT4_GET_BLOCKS_PRE_IO|\
 564                                         EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
 565        /* Convert extent to initialized after IO complete */
 566#define EXT4_GET_BLOCKS_IO_CONVERT_EXT          (EXT4_GET_BLOCKS_CONVERT|\
 567                                         EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
 568        /* Punch out blocks of an extent */
 569#define EXT4_GET_BLOCKS_PUNCH_OUT_EXT           0x0020
 570        /* Don't normalize allocation size (used for fallocate) */
 571#define EXT4_GET_BLOCKS_NO_NORMALIZE            0x0040
 572        /* Request will not result in inode size update (user for fallocate) */
 573#define EXT4_GET_BLOCKS_KEEP_SIZE               0x0080
 574        /* Do not take i_data_sem locking in ext4_map_blocks */
 575#define EXT4_GET_BLOCKS_NO_LOCK                 0x0100
 576
 577/*
 578 * Flags used by ext4_free_blocks
 579 */
 580#define EXT4_FREE_BLOCKS_METADATA       0x0001
 581#define EXT4_FREE_BLOCKS_FORGET         0x0002
 582#define EXT4_FREE_BLOCKS_VALIDATED      0x0004
 583#define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE 0x0008
 584#define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER   0x0010
 585#define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER    0x0020
 586
 587/*
 588 * Flags used by ext4_discard_partial_page_buffers
 589 */
 590#define EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED   0x0001
 591
 592/*
 593 * ioctl commands
 594 */
 595#define EXT4_IOC_GETFLAGS               FS_IOC_GETFLAGS
 596#define EXT4_IOC_SETFLAGS               FS_IOC_SETFLAGS
 597#define EXT4_IOC_GETVERSION             _IOR('f', 3, long)
 598#define EXT4_IOC_SETVERSION             _IOW('f', 4, long)
 599#define EXT4_IOC_GETVERSION_OLD         FS_IOC_GETVERSION
 600#define EXT4_IOC_SETVERSION_OLD         FS_IOC_SETVERSION
 601#define EXT4_IOC_GETRSVSZ               _IOR('f', 5, long)
 602#define EXT4_IOC_SETRSVSZ               _IOW('f', 6, long)
 603#define EXT4_IOC_GROUP_EXTEND           _IOW('f', 7, unsigned long)
 604#define EXT4_IOC_GROUP_ADD              _IOW('f', 8, struct ext4_new_group_input)
 605#define EXT4_IOC_MIGRATE                _IO('f', 9)
 606 /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
 607 /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
 608#define EXT4_IOC_ALLOC_DA_BLKS          _IO('f', 12)
 609#define EXT4_IOC_MOVE_EXT               _IOWR('f', 15, struct move_extent)
 610#define EXT4_IOC_RESIZE_FS              _IOW('f', 16, __u64)
 611
 612#if defined(__KERNEL__) && defined(CONFIG_COMPAT)
 613/*
 614 * ioctl commands in 32 bit emulation
 615 */
 616#define EXT4_IOC32_GETFLAGS             FS_IOC32_GETFLAGS
 617#define EXT4_IOC32_SETFLAGS             FS_IOC32_SETFLAGS
 618#define EXT4_IOC32_GETVERSION           _IOR('f', 3, int)
 619#define EXT4_IOC32_SETVERSION           _IOW('f', 4, int)
 620#define EXT4_IOC32_GETRSVSZ             _IOR('f', 5, int)
 621#define EXT4_IOC32_SETRSVSZ             _IOW('f', 6, int)
 622#define EXT4_IOC32_GROUP_EXTEND         _IOW('f', 7, unsigned int)
 623#define EXT4_IOC32_GROUP_ADD            _IOW('f', 8, struct compat_ext4_new_group_input)
 624#define EXT4_IOC32_GETVERSION_OLD       FS_IOC32_GETVERSION
 625#define EXT4_IOC32_SETVERSION_OLD       FS_IOC32_SETVERSION
 626#endif
 627
 628/* Max physical block we can address w/o extents */
 629#define EXT4_MAX_BLOCK_FILE_PHYS        0xFFFFFFFF
 630
 631/*
 632 * Structure of an inode on the disk
 633 */
 634struct ext4_inode {
 635        __le16  i_mode;         /* File mode */
 636        __le16  i_uid;          /* Low 16 bits of Owner Uid */
 637        __le32  i_size_lo;      /* Size in bytes */
 638        __le32  i_atime;        /* Access time */
 639        __le32  i_ctime;        /* Inode Change time */
 640        __le32  i_mtime;        /* Modification time */
 641        __le32  i_dtime;        /* Deletion Time */
 642        __le16  i_gid;          /* Low 16 bits of Group Id */
 643        __le16  i_links_count;  /* Links count */
 644        __le32  i_blocks_lo;    /* Blocks count */
 645        __le32  i_flags;        /* File flags */
 646        union {
 647                struct {
 648                        __le32  l_i_version;
 649                } linux1;
 650                struct {
 651                        __u32  h_i_translator;
 652                } hurd1;
 653                struct {
 654                        __u32  m_i_reserved1;
 655                } masix1;
 656        } osd1;                         /* OS dependent 1 */
 657        __le32  i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
 658        __le32  i_generation;   /* File version (for NFS) */
 659        __le32  i_file_acl_lo;  /* File ACL */
 660        __le32  i_size_high;
 661        __le32  i_obso_faddr;   /* Obsoleted fragment address */
 662        union {
 663                struct {
 664                        __le16  l_i_blocks_high; /* were l_i_reserved1 */
 665                        __le16  l_i_file_acl_high;
 666                        __le16  l_i_uid_high;   /* these 2 fields */
 667                        __le16  l_i_gid_high;   /* were reserved2[0] */
 668                        __le16  l_i_checksum_lo;/* crc32c(uuid+inum+inode) LE */
 669                        __le16  l_i_reserved;
 670                } linux2;
 671                struct {
 672                        __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
 673                        __u16   h_i_mode_high;
 674                        __u16   h_i_uid_high;
 675                        __u16   h_i_gid_high;
 676                        __u32   h_i_author;
 677                } hurd2;
 678                struct {
 679                        __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
 680                        __le16  m_i_file_acl_high;
 681                        __u32   m_i_reserved2[2];
 682                } masix2;
 683        } osd2;                         /* OS dependent 2 */
 684        __le16  i_extra_isize;
 685        __le16  i_checksum_hi;  /* crc32c(uuid+inum+inode) BE */
 686        __le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
 687        __le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
 688        __le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
 689        __le32  i_crtime;       /* File Creation time */
 690        __le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
 691        __le32  i_version_hi;   /* high 32 bits for 64-bit version */
 692};
 693
 694struct move_extent {
 695        __u32 reserved;         /* should be zero */
 696        __u32 donor_fd;         /* donor file descriptor */
 697        __u64 orig_start;       /* logical start offset in block for orig */
 698        __u64 donor_start;      /* logical start offset in block for donor */
 699        __u64 len;              /* block length to be moved */
 700        __u64 moved_len;        /* moved block length */
 701};
 702
 703#define EXT4_EPOCH_BITS 2
 704#define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
 705#define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
 706
 707/*
 708 * Extended fields will fit into an inode if the filesystem was formatted
 709 * with large inodes (-I 256 or larger) and there are not currently any EAs
 710 * consuming all of the available space. For new inodes we always reserve
 711 * enough space for the kernel's known extended fields, but for inodes
 712 * created with an old kernel this might not have been the case. None of
 713 * the extended inode fields is critical for correct filesystem operation.
 714 * This macro checks if a certain field fits in the inode. Note that
 715 * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
 716 */
 717#define EXT4_FITS_IN_INODE(ext4_inode, einode, field)   \
 718        ((offsetof(typeof(*ext4_inode), field) +        \
 719          sizeof((ext4_inode)->field))                  \
 720        <= (EXT4_GOOD_OLD_INODE_SIZE +                  \
 721            (einode)->i_extra_isize))                   \
 722
 723static inline __le32 ext4_encode_extra_time(struct timespec *time)
 724{
 725       return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
 726                           (time->tv_sec >> 32) & EXT4_EPOCH_MASK : 0) |
 727                          ((time->tv_nsec << EXT4_EPOCH_BITS) & EXT4_NSEC_MASK));
 728}
 729
 730static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
 731{
 732       if (sizeof(time->tv_sec) > 4)
 733               time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
 734                               << 32;
 735       time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
 736}
 737
 738#define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)                          \
 739do {                                                                           \
 740        (raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);               \
 741        if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
 742                (raw_inode)->xtime ## _extra =                                 \
 743                                ext4_encode_extra_time(&(inode)->xtime);       \
 744} while (0)
 745
 746#define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)                        \
 747do {                                                                           \
 748        if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))                      \
 749                (raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
 750        if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))            \
 751                (raw_inode)->xtime ## _extra =                                 \
 752                                ext4_encode_extra_time(&(einode)->xtime);      \
 753} while (0)
 754
 755#define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)                          \
 756do {                                                                           \
 757        (inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
 758        if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
 759                ext4_decode_extra_time(&(inode)->xtime,                        \
 760                                       raw_inode->xtime ## _extra);            \
 761        else                                                                   \
 762                (inode)->xtime.tv_nsec = 0;                                    \
 763} while (0)
 764
 765#define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)                        \
 766do {                                                                           \
 767        if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))                      \
 768                (einode)->xtime.tv_sec =                                       \
 769                        (signed)le32_to_cpu((raw_inode)->xtime);               \
 770        if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))            \
 771                ext4_decode_extra_time(&(einode)->xtime,                       \
 772                                       raw_inode->xtime ## _extra);            \
 773        else                                                                   \
 774                (einode)->xtime.tv_nsec = 0;                                   \
 775} while (0)
 776
 777#define i_disk_version osd1.linux1.l_i_version
 778
 779#if defined(__KERNEL__) || defined(__linux__)
 780#define i_reserved1     osd1.linux1.l_i_reserved1
 781#define i_file_acl_high osd2.linux2.l_i_file_acl_high
 782#define i_blocks_high   osd2.linux2.l_i_blocks_high
 783#define i_uid_low       i_uid
 784#define i_gid_low       i_gid
 785#define i_uid_high      osd2.linux2.l_i_uid_high
 786#define i_gid_high      osd2.linux2.l_i_gid_high
 787#define i_checksum_lo   osd2.linux2.l_i_checksum_lo
 788
 789#elif defined(__GNU__)
 790
 791#define i_translator    osd1.hurd1.h_i_translator
 792#define i_uid_high      osd2.hurd2.h_i_uid_high
 793#define i_gid_high      osd2.hurd2.h_i_gid_high
 794#define i_author        osd2.hurd2.h_i_author
 795
 796#elif defined(__masix__)
 797
 798#define i_reserved1     osd1.masix1.m_i_reserved1
 799#define i_file_acl_high osd2.masix2.m_i_file_acl_high
 800#define i_reserved2     osd2.masix2.m_i_reserved2
 801
 802#endif /* defined(__KERNEL__) || defined(__linux__) */
 803
 804/*
 805 * storage for cached extent
 806 * If ec_len == 0, then the cache is invalid.
 807 * If ec_start == 0, then the cache represents a gap (null mapping)
 808 */
 809struct ext4_ext_cache {
 810        ext4_fsblk_t    ec_start;
 811        ext4_lblk_t     ec_block;
 812        __u32           ec_len; /* must be 32bit to return holes */
 813};
 814
 815/*
 816 * fourth extended file system inode data in memory
 817 */
 818struct ext4_inode_info {
 819        __le32  i_data[15];     /* unconverted */
 820        __u32   i_dtime;
 821        ext4_fsblk_t    i_file_acl;
 822
 823        /*
 824         * i_block_group is the number of the block group which contains
 825         * this file's inode.  Constant across the lifetime of the inode,
 826         * it is ued for making block allocation decisions - we try to
 827         * place a file's data blocks near its inode block, and new inodes
 828         * near to their parent directory's inode.
 829         */
 830        ext4_group_t    i_block_group;
 831        ext4_lblk_t     i_dir_start_lookup;
 832#if (BITS_PER_LONG < 64)
 833        unsigned long   i_state_flags;          /* Dynamic state flags */
 834#endif
 835        unsigned long   i_flags;
 836
 837#ifdef CONFIG_EXT4_FS_XATTR
 838        /*
 839         * Extended attributes can be read independently of the main file
 840         * data. Taking i_mutex even when reading would cause contention
 841         * between readers of EAs and writers of regular file data, so
 842         * instead we synchronize on xattr_sem when reading or changing
 843         * EAs.
 844         */
 845        struct rw_semaphore xattr_sem;
 846#endif
 847
 848        struct list_head i_orphan;      /* unlinked but open inodes */
 849
 850        /*
 851         * i_disksize keeps track of what the inode size is ON DISK, not
 852         * in memory.  During truncate, i_size is set to the new size by
 853         * the VFS prior to calling ext4_truncate(), but the filesystem won't
 854         * set i_disksize to 0 until the truncate is actually under way.
 855         *
 856         * The intent is that i_disksize always represents the blocks which
 857         * are used by this file.  This allows recovery to restart truncate
 858         * on orphans if we crash during truncate.  We actually write i_disksize
 859         * into the on-disk inode when writing inodes out, instead of i_size.
 860         *
 861         * The only time when i_disksize and i_size may be different is when
 862         * a truncate is in progress.  The only things which change i_disksize
 863         * are ext4_get_block (growth) and ext4_truncate (shrinkth).
 864         */
 865        loff_t  i_disksize;
 866
 867        /*
 868         * i_data_sem is for serialising ext4_truncate() against
 869         * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
 870         * data tree are chopped off during truncate. We can't do that in
 871         * ext4 because whenever we perform intermediate commits during
 872         * truncate, the inode and all the metadata blocks *must* be in a
 873         * consistent state which allows truncation of the orphans to restart
 874         * during recovery.  Hence we must fix the get_block-vs-truncate race
 875         * by other means, so we have i_data_sem.
 876         */
 877        struct rw_semaphore i_data_sem;
 878        struct inode vfs_inode;
 879        struct jbd2_inode *jinode;
 880
 881        struct ext4_ext_cache i_cached_extent;
 882        /*
 883         * File creation time. Its function is same as that of
 884         * struct timespec i_{a,c,m}time in the generic inode.
 885         */
 886        struct timespec i_crtime;
 887
 888        /* mballoc */
 889        struct list_head i_prealloc_list;
 890        spinlock_t i_prealloc_lock;
 891
 892        /* ialloc */
 893        ext4_group_t    i_last_alloc_group;
 894
 895        /* allocation reservation info for delalloc */
 896        /* In case of bigalloc, these refer to clusters rather than blocks */
 897        unsigned int i_reserved_data_blocks;
 898        unsigned int i_reserved_meta_blocks;
 899        unsigned int i_allocated_meta_blocks;
 900        ext4_lblk_t i_da_metadata_calc_last_lblock;
 901        int i_da_metadata_calc_len;
 902
 903        /* on-disk additional length */
 904        __u16 i_extra_isize;
 905
 906#ifdef CONFIG_QUOTA
 907        /* quota space reservation, managed internally by quota code */
 908        qsize_t i_reserved_quota;
 909#endif
 910
 911        /* completed IOs that might need unwritten extents handling */
 912        struct list_head i_completed_io_list;
 913        spinlock_t i_completed_io_lock;
 914        atomic_t i_ioend_count; /* Number of outstanding io_end structs */
 915        /* current io_end structure for async DIO write*/
 916        ext4_io_end_t *cur_aio_dio;
 917        atomic_t i_aiodio_unwritten; /* Nr. of inflight conversions pending */
 918
 919        spinlock_t i_block_reservation_lock;
 920
 921        /*
 922         * Transactions that contain inode's metadata needed to complete
 923         * fsync and fdatasync, respectively.
 924         */
 925        tid_t i_sync_tid;
 926        tid_t i_datasync_tid;
 927
 928        /* Precomputed uuid+inum+igen checksum for seeding inode checksums */
 929        __u32 i_csum_seed;
 930};
 931
 932/*
 933 * File system states
 934 */
 935#define EXT4_VALID_FS                   0x0001  /* Unmounted cleanly */
 936#define EXT4_ERROR_FS                   0x0002  /* Errors detected */
 937#define EXT4_ORPHAN_FS                  0x0004  /* Orphans being recovered */
 938
 939/*
 940 * Misc. filesystem flags
 941 */
 942#define EXT2_FLAGS_SIGNED_HASH          0x0001  /* Signed dirhash in use */
 943#define EXT2_FLAGS_UNSIGNED_HASH        0x0002  /* Unsigned dirhash in use */
 944#define EXT2_FLAGS_TEST_FILESYS         0x0004  /* to test development code */
 945
 946/*
 947 * Mount flags
 948 */
 949#define EXT4_MOUNT_GRPID                0x00004 /* Create files with directory's group */
 950#define EXT4_MOUNT_DEBUG                0x00008 /* Some debugging messages */
 951#define EXT4_MOUNT_ERRORS_CONT          0x00010 /* Continue on errors */
 952#define EXT4_MOUNT_ERRORS_RO            0x00020 /* Remount fs ro on errors */
 953#define EXT4_MOUNT_ERRORS_PANIC         0x00040 /* Panic on errors */
 954#define EXT4_MOUNT_ERRORS_MASK          0x00070
 955#define EXT4_MOUNT_MINIX_DF             0x00080 /* Mimics the Minix statfs */
 956#define EXT4_MOUNT_NOLOAD               0x00100 /* Don't use existing journal*/
 957#define EXT4_MOUNT_DATA_FLAGS           0x00C00 /* Mode for data writes: */
 958#define EXT4_MOUNT_JOURNAL_DATA         0x00400 /* Write data to journal */
 959#define EXT4_MOUNT_ORDERED_DATA         0x00800 /* Flush data before commit */
 960#define EXT4_MOUNT_WRITEBACK_DATA       0x00C00 /* No data ordering */
 961#define EXT4_MOUNT_UPDATE_JOURNAL       0x01000 /* Update the journal format */
 962#define EXT4_MOUNT_NO_UID32             0x02000  /* Disable 32-bit UIDs */
 963#define EXT4_MOUNT_XATTR_USER           0x04000 /* Extended user attributes */
 964#define EXT4_MOUNT_POSIX_ACL            0x08000 /* POSIX Access Control Lists */
 965#define EXT4_MOUNT_NO_AUTO_DA_ALLOC     0x10000 /* No auto delalloc mapping */
 966#define EXT4_MOUNT_BARRIER              0x20000 /* Use block barriers */
 967#define EXT4_MOUNT_QUOTA                0x80000 /* Some quota option set */
 968#define EXT4_MOUNT_USRQUOTA             0x100000 /* "old" user quota */
 969#define EXT4_MOUNT_GRPQUOTA             0x200000 /* "old" group quota */
 970#define EXT4_MOUNT_DIOREAD_NOLOCK       0x400000 /* Enable support for dio read nolocking */
 971#define EXT4_MOUNT_JOURNAL_CHECKSUM     0x800000 /* Journal checksums */
 972#define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT 0x1000000 /* Journal Async Commit */
 973#define EXT4_MOUNT_MBLK_IO_SUBMIT       0x4000000 /* multi-block io submits */
 974#define EXT4_MOUNT_DELALLOC             0x8000000 /* Delalloc support */
 975#define EXT4_MOUNT_DATA_ERR_ABORT       0x10000000 /* Abort on file data write */
 976#define EXT4_MOUNT_BLOCK_VALIDITY       0x20000000 /* Block validity checking */
 977#define EXT4_MOUNT_DISCARD              0x40000000 /* Issue DISCARD requests */
 978#define EXT4_MOUNT_INIT_INODE_TABLE     0x80000000 /* Initialize uninitialized itables */
 979
 980#define EXT4_MOUNT2_EXPLICIT_DELALLOC   0x00000001 /* User explicitly
 981                                                      specified delalloc */
 982
 983#define clear_opt(sb, opt)              EXT4_SB(sb)->s_mount_opt &= \
 984                                                ~EXT4_MOUNT_##opt
 985#define set_opt(sb, opt)                EXT4_SB(sb)->s_mount_opt |= \
 986                                                EXT4_MOUNT_##opt
 987#define test_opt(sb, opt)               (EXT4_SB(sb)->s_mount_opt & \
 988                                         EXT4_MOUNT_##opt)
 989
 990#define clear_opt2(sb, opt)             EXT4_SB(sb)->s_mount_opt2 &= \
 991                                                ~EXT4_MOUNT2_##opt
 992#define set_opt2(sb, opt)               EXT4_SB(sb)->s_mount_opt2 |= \
 993                                                EXT4_MOUNT2_##opt
 994#define test_opt2(sb, opt)              (EXT4_SB(sb)->s_mount_opt2 & \
 995                                         EXT4_MOUNT2_##opt)
 996
 997#define ext4_test_and_set_bit           __test_and_set_bit_le
 998#define ext4_set_bit                    __set_bit_le
 999#define ext4_set_bit_atomic             ext2_set_bit_atomic
1000#define ext4_test_and_clear_bit         __test_and_clear_bit_le
1001#define ext4_clear_bit                  __clear_bit_le
1002#define ext4_clear_bit_atomic           ext2_clear_bit_atomic
1003#define ext4_test_bit                   test_bit_le
1004#define ext4_find_next_zero_bit         find_next_zero_bit_le
1005#define ext4_find_next_bit              find_next_bit_le
1006
1007extern void ext4_set_bits(void *bm, int cur, int len);
1008
1009/*
1010 * Maximal mount counts between two filesystem checks
1011 */
1012#define EXT4_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
1013#define EXT4_DFL_CHECKINTERVAL          0       /* Don't use interval check */
1014
1015/*
1016 * Behaviour when detecting errors
1017 */
1018#define EXT4_ERRORS_CONTINUE            1       /* Continue execution */
1019#define EXT4_ERRORS_RO                  2       /* Remount fs read-only */
1020#define EXT4_ERRORS_PANIC               3       /* Panic */
1021#define EXT4_ERRORS_DEFAULT             EXT4_ERRORS_CONTINUE
1022
1023/* Metadata checksum algorithm codes */
1024#define EXT4_CRC32C_CHKSUM              1
1025
1026/*
1027 * Structure of the super block
1028 */
1029struct ext4_super_block {
1030/*00*/  __le32  s_inodes_count;         /* Inodes count */
1031        __le32  s_blocks_count_lo;      /* Blocks count */
1032        __le32  s_r_blocks_count_lo;    /* Reserved blocks count */
1033        __le32  s_free_blocks_count_lo; /* Free blocks count */
1034/*10*/  __le32  s_free_inodes_count;    /* Free inodes count */
1035        __le32  s_first_data_block;     /* First Data Block */
1036        __le32  s_log_block_size;       /* Block size */
1037        __le32  s_log_cluster_size;     /* Allocation cluster size */
1038/*20*/  __le32  s_blocks_per_group;     /* # Blocks per group */
1039        __le32  s_clusters_per_group;   /* # Clusters per group */
1040        __le32  s_inodes_per_group;     /* # Inodes per group */
1041        __le32  s_mtime;                /* Mount time */
1042/*30*/  __le32  s_wtime;                /* Write time */
1043        __le16  s_mnt_count;            /* Mount count */
1044        __le16  s_max_mnt_count;        /* Maximal mount count */
1045        __le16  s_magic;                /* Magic signature */
1046        __le16  s_state;                /* File system state */
1047        __le16  s_errors;               /* Behaviour when detecting errors */
1048        __le16  s_minor_rev_level;      /* minor revision level */
1049/*40*/  __le32  s_lastcheck;            /* time of last check */
1050        __le32  s_checkinterval;        /* max. time between checks */
1051        __le32  s_creator_os;           /* OS */
1052        __le32  s_rev_level;            /* Revision level */
1053/*50*/  __le16  s_def_resuid;           /* Default uid for reserved blocks */
1054        __le16  s_def_resgid;           /* Default gid for reserved blocks */
1055        /*
1056         * These fields are for EXT4_DYNAMIC_REV superblocks only.
1057         *
1058         * Note: the difference between the compatible feature set and
1059         * the incompatible feature set is that if there is a bit set
1060         * in the incompatible feature set that the kernel doesn't
1061         * know about, it should refuse to mount the filesystem.
1062         *
1063         * e2fsck's requirements are more strict; if it doesn't know
1064         * about a feature in either the compatible or incompatible
1065         * feature set, it must abort and not try to meddle with
1066         * things it doesn't understand...
1067         */
1068        __le32  s_first_ino;            /* First non-reserved inode */
1069        __le16  s_inode_size;           /* size of inode structure */
1070        __le16  s_block_group_nr;       /* block group # of this superblock */
1071        __le32  s_feature_compat;       /* compatible feature set */
1072/*60*/  __le32  s_feature_incompat;     /* incompatible feature set */
1073        __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
1074/*68*/  __u8    s_uuid[16];             /* 128-bit uuid for volume */
1075/*78*/  char    s_volume_name[16];      /* volume name */
1076/*88*/  char    s_last_mounted[64];     /* directory where last mounted */
1077/*C8*/  __le32  s_algorithm_usage_bitmap; /* For compression */
1078        /*
1079         * Performance hints.  Directory preallocation should only
1080         * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
1081         */
1082        __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
1083        __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
1084        __le16  s_reserved_gdt_blocks;  /* Per group desc for online growth */
1085        /*
1086         * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
1087         */
1088/*D0*/  __u8    s_journal_uuid[16];     /* uuid of journal superblock */
1089/*E0*/  __le32  s_journal_inum;         /* inode number of journal file */
1090        __le32  s_journal_dev;          /* device number of journal file */
1091        __le32  s_last_orphan;          /* start of list of inodes to delete */
1092        __le32  s_hash_seed[4];         /* HTREE hash seed */
1093        __u8    s_def_hash_version;     /* Default hash version to use */
1094        __u8    s_jnl_backup_type;
1095        __le16  s_desc_size;            /* size of group descriptor */
1096/*100*/ __le32  s_default_mount_opts;
1097        __le32  s_first_meta_bg;        /* First metablock block group */
1098        __le32  s_mkfs_time;            /* When the filesystem was created */
1099        __le32  s_jnl_blocks[17];       /* Backup of the journal inode */
1100        /* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
1101/*150*/ __le32  s_blocks_count_hi;      /* Blocks count */
1102        __le32  s_r_blocks_count_hi;    /* Reserved blocks count */
1103        __le32  s_free_blocks_count_hi; /* Free blocks count */
1104        __le16  s_min_extra_isize;      /* All inodes have at least # bytes */
1105        __le16  s_want_extra_isize;     /* New inodes should reserve # bytes */
1106        __le32  s_flags;                /* Miscellaneous flags */
1107        __le16  s_raid_stride;          /* RAID stride */
1108        __le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */
1109        __le64  s_mmp_block;            /* Block for multi-mount protection */
1110        __le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1111        __u8    s_log_groups_per_flex;  /* FLEX_BG group size */
1112        __u8    s_checksum_type;        /* metadata checksum algorithm used */
1113        __le16  s_reserved_pad;
1114        __le64  s_kbytes_written;       /* nr of lifetime kilobytes written */
1115        __le32  s_snapshot_inum;        /* Inode number of active snapshot */
1116        __le32  s_snapshot_id;          /* sequential ID of active snapshot */
1117        __le64  s_snapshot_r_blocks_count; /* reserved blocks for active
1118                                              snapshot's future use */
1119        __le32  s_snapshot_list;        /* inode number of the head of the
1120                                           on-disk snapshot list */
1121#define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
1122        __le32  s_error_count;          /* number of fs errors */
1123        __le32  s_first_error_time;     /* first time an error happened */
1124        __le32  s_first_error_ino;      /* inode involved in first error */
1125        __le64  s_first_error_block;    /* block involved of first error */
1126        __u8    s_first_error_func[32]; /* function where the error happened */
1127        __le32  s_first_error_line;     /* line number where error happened */
1128        __le32  s_last_error_time;      /* most recent time of an error */
1129        __le32  s_last_error_ino;       /* inode involved in last error */
1130        __le32  s_last_error_line;      /* line number where error happened */
1131        __le64  s_last_error_block;     /* block involved of last error */
1132        __u8    s_last_error_func[32];  /* function where the error happened */
1133#define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
1134        __u8    s_mount_opts[64];
1135        __le32  s_usr_quota_inum;       /* inode for tracking user quota */
1136        __le32  s_grp_quota_inum;       /* inode for tracking group quota */
1137        __le32  s_overhead_clusters;    /* overhead blocks/clusters in fs */
1138        __le32  s_reserved[108];        /* Padding to the end of the block */
1139        __le32  s_checksum;             /* crc32c(superblock) */
1140};
1141
1142#define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1143
1144#ifdef __KERNEL__
1145
1146/*
1147 * run-time mount flags
1148 */
1149#define EXT4_MF_MNTDIR_SAMPLED  0x0001
1150#define EXT4_MF_FS_ABORTED      0x0002  /* Fatal error detected */
1151
1152/*
1153 * fourth extended-fs super-block data in memory
1154 */
1155struct ext4_sb_info {
1156        unsigned long s_desc_size;      /* Size of a group descriptor in bytes */
1157        unsigned long s_inodes_per_block;/* Number of inodes per block */
1158        unsigned long s_blocks_per_group;/* Number of blocks in a group */
1159        unsigned long s_clusters_per_group; /* Number of clusters in a group */
1160        unsigned long s_inodes_per_group;/* Number of inodes in a group */
1161        unsigned long s_itb_per_group;  /* Number of inode table blocks per group */
1162        unsigned long s_gdb_count;      /* Number of group descriptor blocks */
1163        unsigned long s_desc_per_block; /* Number of group descriptors per block */
1164        ext4_group_t s_groups_count;    /* Number of groups in the fs */
1165        ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1166        unsigned long s_overhead;  /* # of fs overhead clusters */
1167        unsigned int s_cluster_ratio;   /* Number of blocks per cluster */
1168        unsigned int s_cluster_bits;    /* log2 of s_cluster_ratio */
1169        loff_t s_bitmap_maxbytes;       /* max bytes for bitmap files */
1170        struct buffer_head * s_sbh;     /* Buffer containing the super block */
1171        struct ext4_super_block *s_es;  /* Pointer to the super block in the buffer */
1172        struct buffer_head **s_group_desc;
1173        unsigned int s_mount_opt;
1174        unsigned int s_mount_opt2;
1175        unsigned int s_mount_flags;
1176        unsigned int s_def_mount_opt;
1177        ext4_fsblk_t s_sb_block;
1178        kuid_t s_resuid;
1179        kgid_t s_resgid;
1180        unsigned short s_mount_state;
1181        unsigned short s_pad;
1182        int s_addr_per_block_bits;
1183        int s_desc_per_block_bits;
1184        int s_inode_size;
1185        int s_first_ino;
1186        unsigned int s_inode_readahead_blks;
1187        unsigned int s_inode_goal;
1188        spinlock_t s_next_gen_lock;
1189        u32 s_next_generation;
1190        u32 s_hash_seed[4];
1191        int s_def_hash_version;
1192        int s_hash_unsigned;    /* 3 if hash should be signed, 0 if not */
1193        struct percpu_counter s_freeclusters_counter;
1194        struct percpu_counter s_freeinodes_counter;
1195        struct percpu_counter s_dirs_counter;
1196        struct percpu_counter s_dirtyclusters_counter;
1197        struct blockgroup_lock *s_blockgroup_lock;
1198        struct proc_dir_entry *s_proc;
1199        struct kobject s_kobj;
1200        struct completion s_kobj_unregister;
1201        struct super_block *s_sb;
1202
1203        /* Journaling */
1204        struct journal_s *s_journal;
1205        struct list_head s_orphan;
1206        struct mutex s_orphan_lock;
1207        unsigned long s_resize_flags;           /* Flags indicating if there
1208                                                   is a resizer */
1209        unsigned long s_commit_interval;
1210        u32 s_max_batch_time;
1211        u32 s_min_batch_time;
1212        struct block_device *journal_bdev;
1213#ifdef CONFIG_QUOTA
1214        char *s_qf_names[MAXQUOTAS];            /* Names of quota files with journalled quota */
1215        int s_jquota_fmt;                       /* Format of quota to use */
1216#endif
1217        unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1218        struct rb_root system_blks;
1219
1220#ifdef EXTENTS_STATS
1221        /* ext4 extents stats */
1222        unsigned long s_ext_min;
1223        unsigned long s_ext_max;
1224        unsigned long s_depth_max;
1225        spinlock_t s_ext_stats_lock;
1226        unsigned long s_ext_blocks;
1227        unsigned long s_ext_extents;
1228#endif
1229
1230        /* for buddy allocator */
1231        struct ext4_group_info ***s_group_info;
1232        struct inode *s_buddy_cache;
1233        spinlock_t s_md_lock;
1234        unsigned short *s_mb_offsets;
1235        unsigned int *s_mb_maxs;
1236
1237        /* tunables */
1238        unsigned long s_stripe;
1239        unsigned int s_mb_stream_request;
1240        unsigned int s_mb_max_to_scan;
1241        unsigned int s_mb_min_to_scan;
1242        unsigned int s_mb_stats;
1243        unsigned int s_mb_order2_reqs;
1244        unsigned int s_mb_group_prealloc;
1245        unsigned int s_max_writeback_mb_bump;
1246        /* where last allocation was done - for stream allocation */
1247        unsigned long s_mb_last_group;
1248        unsigned long s_mb_last_start;
1249
1250        /* stats for buddy allocator */
1251        atomic_t s_bal_reqs;    /* number of reqs with len > 1 */
1252        atomic_t s_bal_success; /* we found long enough chunks */
1253        atomic_t s_bal_allocated;       /* in blocks */
1254        atomic_t s_bal_ex_scanned;      /* total extents scanned */
1255        atomic_t s_bal_goals;   /* goal hits */
1256        atomic_t s_bal_breaks;  /* too long searches */
1257        atomic_t s_bal_2orders; /* 2^order hits */
1258        spinlock_t s_bal_lock;
1259        unsigned long s_mb_buddies_generated;
1260        unsigned long long s_mb_generation_time;
1261        atomic_t s_mb_lost_chunks;
1262        atomic_t s_mb_preallocated;
1263        atomic_t s_mb_discarded;
1264        atomic_t s_lock_busy;
1265
1266        /* locality groups */
1267        struct ext4_locality_group __percpu *s_locality_groups;
1268
1269        /* for write statistics */
1270        unsigned long s_sectors_written_start;
1271        u64 s_kbytes_written;
1272
1273        unsigned int s_log_groups_per_flex;
1274        struct flex_groups *s_flex_groups;
1275
1276        /* workqueue for dio unwritten */
1277        struct workqueue_struct *dio_unwritten_wq;
1278
1279        /* timer for periodic error stats printing */
1280        struct timer_list s_err_report;
1281
1282        /* Lazy inode table initialization info */
1283        struct ext4_li_request *s_li_request;
1284        /* Wait multiplier for lazy initialization thread */
1285        unsigned int s_li_wait_mult;
1286
1287        /* Kernel thread for multiple mount protection */
1288        struct task_struct *s_mmp_tsk;
1289
1290        /* record the last minlen when FITRIM is called. */
1291        atomic_t s_last_trim_minblks;
1292
1293        /* Reference to checksum algorithm driver via cryptoapi */
1294        struct crypto_shash *s_chksum_driver;
1295
1296        /* Precomputed FS UUID checksum for seeding other checksums */
1297        __u32 s_csum_seed;
1298};
1299
1300static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1301{
1302        return sb->s_fs_info;
1303}
1304static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1305{
1306        return container_of(inode, struct ext4_inode_info, vfs_inode);
1307}
1308
1309static inline struct timespec ext4_current_time(struct inode *inode)
1310{
1311        return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1312                current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1313}
1314
1315static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1316{
1317        return ino == EXT4_ROOT_INO ||
1318                ino == EXT4_USR_QUOTA_INO ||
1319                ino == EXT4_GRP_QUOTA_INO ||
1320                ino == EXT4_JOURNAL_INO ||
1321                ino == EXT4_RESIZE_INO ||
1322                (ino >= EXT4_FIRST_INO(sb) &&
1323                 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1324}
1325
1326static inline void ext4_set_io_unwritten_flag(struct inode *inode,
1327                                              struct ext4_io_end *io_end)
1328{
1329        if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
1330                io_end->flag |= EXT4_IO_END_UNWRITTEN;
1331                atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten);
1332        }
1333}
1334
1335/*
1336 * Inode dynamic state flags
1337 */
1338enum {
1339        EXT4_STATE_JDATA,               /* journaled data exists */
1340        EXT4_STATE_NEW,                 /* inode is newly created */
1341        EXT4_STATE_XATTR,               /* has in-inode xattrs */
1342        EXT4_STATE_NO_EXPAND,           /* No space for expansion */
1343        EXT4_STATE_DA_ALLOC_CLOSE,      /* Alloc DA blks on close */
1344        EXT4_STATE_EXT_MIGRATE,         /* Inode is migrating */
1345        EXT4_STATE_DIO_UNWRITTEN,       /* need convert on dio done*/
1346        EXT4_STATE_NEWENTRY,            /* File just added to dir */
1347        EXT4_STATE_DELALLOC_RESERVED,   /* blks already reserved for delalloc */
1348};
1349
1350#define EXT4_INODE_BIT_FNS(name, field, offset)                         \
1351static inline int ext4_test_inode_##name(struct inode *inode, int bit)  \
1352{                                                                       \
1353        return test_bit(bit + (offset), &EXT4_I(inode)->i_##field);     \
1354}                                                                       \
1355static inline void ext4_set_inode_##name(struct inode *inode, int bit)  \
1356{                                                                       \
1357        set_bit(bit + (offset), &EXT4_I(inode)->i_##field);             \
1358}                                                                       \
1359static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1360{                                                                       \
1361        clear_bit(bit + (offset), &EXT4_I(inode)->i_##field);           \
1362}
1363
1364EXT4_INODE_BIT_FNS(flag, flags, 0)
1365#if (BITS_PER_LONG < 64)
1366EXT4_INODE_BIT_FNS(state, state_flags, 0)
1367
1368static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1369{
1370        (ei)->i_state_flags = 0;
1371}
1372#else
1373EXT4_INODE_BIT_FNS(state, flags, 32)
1374
1375static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1376{
1377        /* We depend on the fact that callers will set i_flags */
1378}
1379#endif
1380#else
1381/* Assume that user mode programs are passing in an ext4fs superblock, not
1382 * a kernel struct super_block.  This will allow us to call the feature-test
1383 * macros from user land. */
1384#define EXT4_SB(sb)     (sb)
1385#endif
1386
1387#define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1388
1389/*
1390 * Codes for operating systems
1391 */
1392#define EXT4_OS_LINUX           0
1393#define EXT4_OS_HURD            1
1394#define EXT4_OS_MASIX           2
1395#define EXT4_OS_FREEBSD         3
1396#define EXT4_OS_LITES           4
1397
1398/*
1399 * Revision levels
1400 */
1401#define EXT4_GOOD_OLD_REV       0       /* The good old (original) format */
1402#define EXT4_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
1403
1404#define EXT4_CURRENT_REV        EXT4_GOOD_OLD_REV
1405#define EXT4_MAX_SUPP_REV       EXT4_DYNAMIC_REV
1406
1407#define EXT4_GOOD_OLD_INODE_SIZE 128
1408
1409/*
1410 * Feature set definitions
1411 */
1412
1413#define EXT4_HAS_COMPAT_FEATURE(sb,mask)                        \
1414        ((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1415#define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
1416        ((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1417#define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)                      \
1418        ((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1419#define EXT4_SET_COMPAT_FEATURE(sb,mask)                        \
1420        EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1421#define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)                     \
1422        EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1423#define EXT4_SET_INCOMPAT_FEATURE(sb,mask)                      \
1424        EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1425#define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)                      \
1426        EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1427#define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
1428        EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1429#define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
1430        EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1431
1432#define EXT4_FEATURE_COMPAT_DIR_PREALLOC        0x0001
1433#define EXT4_FEATURE_COMPAT_IMAGIC_INODES       0x0002
1434#define EXT4_FEATURE_COMPAT_HAS_JOURNAL         0x0004
1435#define EXT4_FEATURE_COMPAT_EXT_ATTR            0x0008
1436#define EXT4_FEATURE_COMPAT_RESIZE_INODE        0x0010
1437#define EXT4_FEATURE_COMPAT_DIR_INDEX           0x0020
1438
1439#define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
1440#define EXT4_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
1441#define EXT4_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
1442#define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1443#define EXT4_FEATURE_RO_COMPAT_GDT_CSUM         0x0010
1444#define EXT4_FEATURE_RO_COMPAT_DIR_NLINK        0x0020
1445#define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE      0x0040
1446#define EXT4_FEATURE_RO_COMPAT_QUOTA            0x0100
1447#define EXT4_FEATURE_RO_COMPAT_BIGALLOC         0x0200
1448/*
1449 * METADATA_CSUM also enables group descriptor checksums (GDT_CSUM).  When
1450 * METADATA_CSUM is set, group descriptor checksums use the same algorithm as
1451 * all other data structures' checksums.  However, the METADATA_CSUM and
1452 * GDT_CSUM bits are mutually exclusive.
1453 */
1454#define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM    0x0400
1455
1456#define EXT4_FEATURE_INCOMPAT_COMPRESSION       0x0001
1457#define EXT4_FEATURE_INCOMPAT_FILETYPE          0x0002
1458#define EXT4_FEATURE_INCOMPAT_RECOVER           0x0004 /* Needs recovery */
1459#define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008 /* Journal device */
1460#define EXT4_FEATURE_INCOMPAT_META_BG           0x0010
1461#define EXT4_FEATURE_INCOMPAT_EXTENTS           0x0040 /* extents support */
1462#define EXT4_FEATURE_INCOMPAT_64BIT             0x0080
1463#define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1464#define EXT4_FEATURE_INCOMPAT_FLEX_BG           0x0200
1465#define EXT4_FEATURE_INCOMPAT_EA_INODE          0x0400 /* EA in inode */
1466#define EXT4_FEATURE_INCOMPAT_DIRDATA           0x1000 /* data in dirent */
1467#define EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM  0x2000 /* use crc32c for bg */
1468#define EXT4_FEATURE_INCOMPAT_LARGEDIR          0x4000 /* >2GB or 3-lvl htree */
1469#define EXT4_FEATURE_INCOMPAT_INLINEDATA        0x8000 /* data in inode */
1470
1471#define EXT2_FEATURE_COMPAT_SUPP        EXT4_FEATURE_COMPAT_EXT_ATTR
1472#define EXT2_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1473                                         EXT4_FEATURE_INCOMPAT_META_BG)
1474#define EXT2_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1475                                         EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1476                                         EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1477
1478#define EXT3_FEATURE_COMPAT_SUPP        EXT4_FEATURE_COMPAT_EXT_ATTR
1479#define EXT3_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1480                                         EXT4_FEATURE_INCOMPAT_RECOVER| \
1481                                         EXT4_FEATURE_INCOMPAT_META_BG)
1482#define EXT3_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1483                                         EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1484                                         EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1485
1486#define EXT4_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
1487#define EXT4_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1488                                         EXT4_FEATURE_INCOMPAT_RECOVER| \
1489                                         EXT4_FEATURE_INCOMPAT_META_BG| \
1490                                         EXT4_FEATURE_INCOMPAT_EXTENTS| \
1491                                         EXT4_FEATURE_INCOMPAT_64BIT| \
1492                                         EXT4_FEATURE_INCOMPAT_FLEX_BG| \
1493                                         EXT4_FEATURE_INCOMPAT_MMP)
1494#define EXT4_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1495                                         EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1496                                         EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1497                                         EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1498                                         EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1499                                         EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1500                                         EXT4_FEATURE_RO_COMPAT_HUGE_FILE |\
1501                                         EXT4_FEATURE_RO_COMPAT_BIGALLOC |\
1502                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
1503                                         EXT4_FEATURE_RO_COMPAT_QUOTA)
1504
1505/*
1506 * Default values for user and/or group using reserved blocks
1507 */
1508#define EXT4_DEF_RESUID         0
1509#define EXT4_DEF_RESGID         0
1510
1511#define EXT4_DEF_INODE_READAHEAD_BLKS   32
1512
1513/*
1514 * Default mount options
1515 */
1516#define EXT4_DEFM_DEBUG         0x0001
1517#define EXT4_DEFM_BSDGROUPS     0x0002
1518#define EXT4_DEFM_XATTR_USER    0x0004
1519#define EXT4_DEFM_ACL           0x0008
1520#define EXT4_DEFM_UID16         0x0010
1521#define EXT4_DEFM_JMODE         0x0060
1522#define EXT4_DEFM_JMODE_DATA    0x0020
1523#define EXT4_DEFM_JMODE_ORDERED 0x0040
1524#define EXT4_DEFM_JMODE_WBACK   0x0060
1525#define EXT4_DEFM_NOBARRIER     0x0100
1526#define EXT4_DEFM_BLOCK_VALIDITY 0x0200
1527#define EXT4_DEFM_DISCARD       0x0400
1528#define EXT4_DEFM_NODELALLOC    0x0800
1529
1530/*
1531 * Default journal batch times
1532 */
1533#define EXT4_DEF_MIN_BATCH_TIME 0
1534#define EXT4_DEF_MAX_BATCH_TIME 15000 /* 15ms */
1535
1536/*
1537 * Minimum number of groups in a flexgroup before we separate out
1538 * directories into the first block group of a flexgroup
1539 */
1540#define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME 4
1541
1542/*
1543 * Structure of a directory entry
1544 */
1545#define EXT4_NAME_LEN 255
1546
1547struct ext4_dir_entry {
1548        __le32  inode;                  /* Inode number */
1549        __le16  rec_len;                /* Directory entry length */
1550        __le16  name_len;               /* Name length */
1551        char    name[EXT4_NAME_LEN];    /* File name */
1552};
1553
1554/*
1555 * The new version of the directory entry.  Since EXT4 structures are
1556 * stored in intel byte order, and the name_len field could never be
1557 * bigger than 255 chars, it's safe to reclaim the extra byte for the
1558 * file_type field.
1559 */
1560struct ext4_dir_entry_2 {
1561        __le32  inode;                  /* Inode number */
1562        __le16  rec_len;                /* Directory entry length */
1563        __u8    name_len;               /* Name length */
1564        __u8    file_type;
1565        char    name[EXT4_NAME_LEN];    /* File name */
1566};
1567
1568/*
1569 * This is a bogus directory entry at the end of each leaf block that
1570 * records checksums.
1571 */
1572struct ext4_dir_entry_tail {
1573        __le32  det_reserved_zero1;     /* Pretend to be unused */
1574        __le16  det_rec_len;            /* 12 */
1575        __u8    det_reserved_zero2;     /* Zero name length */
1576        __u8    det_reserved_ft;        /* 0xDE, fake file type */
1577        __le32  det_checksum;           /* crc32c(uuid+inum+dirblock) */
1578};
1579
1580/*
1581 * Ext4 directory file types.  Only the low 3 bits are used.  The
1582 * other bits are reserved for now.
1583 */
1584#define EXT4_FT_UNKNOWN         0
1585#define EXT4_FT_REG_FILE        1
1586#define EXT4_FT_DIR             2
1587#define EXT4_FT_CHRDEV          3
1588#define EXT4_FT_BLKDEV          4
1589#define EXT4_FT_FIFO            5
1590#define EXT4_FT_SOCK            6
1591#define EXT4_FT_SYMLINK         7
1592
1593#define EXT4_FT_MAX             8
1594
1595#define EXT4_FT_DIR_CSUM        0xDE
1596
1597/*
1598 * EXT4_DIR_PAD defines the directory entries boundaries
1599 *
1600 * NOTE: It must be a multiple of 4
1601 */
1602#define EXT4_DIR_PAD                    4
1603#define EXT4_DIR_ROUND                  (EXT4_DIR_PAD - 1)
1604#define EXT4_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT4_DIR_ROUND) & \
1605                                         ~EXT4_DIR_ROUND)
1606#define EXT4_MAX_REC_LEN                ((1<<16)-1)
1607
1608/*
1609 * If we ever get support for fs block sizes > page_size, we'll need
1610 * to remove the #if statements in the next two functions...
1611 */
1612static inline unsigned int
1613ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
1614{
1615        unsigned len = le16_to_cpu(dlen);
1616
1617#if (PAGE_CACHE_SIZE >= 65536)
1618        if (len == EXT4_MAX_REC_LEN || len == 0)
1619                return blocksize;
1620        return (len & 65532) | ((len & 3) << 16);
1621#else
1622        return len;
1623#endif
1624}
1625
1626static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
1627{
1628        if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
1629                BUG();
1630#if (PAGE_CACHE_SIZE >= 65536)
1631        if (len < 65536)
1632                return cpu_to_le16(len);
1633        if (len == blocksize) {
1634                if (blocksize == 65536)
1635                        return cpu_to_le16(EXT4_MAX_REC_LEN);
1636                else
1637                        return cpu_to_le16(0);
1638        }
1639        return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
1640#else
1641        return cpu_to_le16(len);
1642#endif
1643}
1644
1645/*
1646 * Hash Tree Directory indexing
1647 * (c) Daniel Phillips, 2001
1648 */
1649
1650#define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1651                                      EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1652                    ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
1653#define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1654#define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1655
1656/* Legal values for the dx_root hash_version field: */
1657
1658#define DX_HASH_LEGACY          0
1659#define DX_HASH_HALF_MD4        1
1660#define DX_HASH_TEA             2
1661#define DX_HASH_LEGACY_UNSIGNED 3
1662#define DX_HASH_HALF_MD4_UNSIGNED       4
1663#define DX_HASH_TEA_UNSIGNED            5
1664
1665static inline u32 ext4_chksum(struct ext4_sb_info *sbi, u32 crc,
1666                              const void *address, unsigned int length)
1667{
1668        struct {
1669                struct shash_desc shash;
1670                char ctx[4];
1671        } desc;
1672        int err;
1673
1674        BUG_ON(crypto_shash_descsize(sbi->s_chksum_driver)!=sizeof(desc.ctx));
1675
1676        desc.shash.tfm = sbi->s_chksum_driver;
1677        desc.shash.flags = 0;
1678        *(u32 *)desc.ctx = crc;
1679
1680        err = crypto_shash_update(&desc.shash, address, length);
1681        BUG_ON(err);
1682
1683        return *(u32 *)desc.ctx;
1684}
1685
1686#ifdef __KERNEL__
1687
1688/* hash info structure used by the directory hash */
1689struct dx_hash_info
1690{
1691        u32             hash;
1692        u32             minor_hash;
1693        int             hash_version;
1694        u32             *seed;
1695};
1696
1697
1698/* 32 and 64 bit signed EOF for dx directories */
1699#define EXT4_HTREE_EOF_32BIT   ((1UL  << (32 - 1)) - 1)
1700#define EXT4_HTREE_EOF_64BIT   ((1ULL << (64 - 1)) - 1)
1701
1702
1703/*
1704 * Control parameters used by ext4_htree_next_block
1705 */
1706#define HASH_NB_ALWAYS          1
1707
1708
1709/*
1710 * Describe an inode's exact location on disk and in memory
1711 */
1712struct ext4_iloc
1713{
1714        struct buffer_head *bh;
1715        unsigned long offset;
1716        ext4_group_t block_group;
1717};
1718
1719static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1720{
1721        return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1722}
1723
1724/*
1725 * This structure is stuffed into the struct file's private_data field
1726 * for directories.  It is where we put information so that we can do
1727 * readdir operations in hash tree order.
1728 */
1729struct dir_private_info {
1730        struct rb_root  root;
1731        struct rb_node  *curr_node;
1732        struct fname    *extra_fname;
1733        loff_t          last_pos;
1734        __u32           curr_hash;
1735        __u32           curr_minor_hash;
1736        __u32           next_hash;
1737};
1738
1739/* calculate the first block number of the group */
1740static inline ext4_fsblk_t
1741ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1742{
1743        return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1744                le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1745}
1746
1747/*
1748 * Special error return code only used by dx_probe() and its callers.
1749 */
1750#define ERR_BAD_DX_DIR  -75000
1751
1752void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
1753                        ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp);
1754
1755/*
1756 * Timeout and state flag for lazy initialization inode thread.
1757 */
1758#define EXT4_DEF_LI_WAIT_MULT                   10
1759#define EXT4_DEF_LI_MAX_START_DELAY             5
1760#define EXT4_LAZYINIT_QUIT                      0x0001
1761#define EXT4_LAZYINIT_RUNNING                   0x0002
1762
1763/*
1764 * Lazy inode table initialization info
1765 */
1766struct ext4_lazy_init {
1767        unsigned long           li_state;
1768        struct list_head        li_request_list;
1769        struct mutex            li_list_mtx;
1770};
1771
1772struct ext4_li_request {
1773        struct super_block      *lr_super;
1774        struct ext4_sb_info     *lr_sbi;
1775        ext4_group_t            lr_next_group;
1776        struct list_head        lr_request;
1777        unsigned long           lr_next_sched;
1778        unsigned long           lr_timeout;
1779};
1780
1781struct ext4_features {
1782        struct kobject f_kobj;
1783        struct completion f_kobj_unregister;
1784};
1785
1786/*
1787 * This structure will be used for multiple mount protection. It will be
1788 * written into the block number saved in the s_mmp_block field in the
1789 * superblock. Programs that check MMP should assume that if
1790 * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
1791 * to use the filesystem, regardless of how old the timestamp is.
1792 */
1793#define EXT4_MMP_MAGIC     0x004D4D50U /* ASCII for MMP */
1794#define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
1795#define EXT4_MMP_SEQ_FSCK  0xE24D4D50U /* mmp_seq value when being fscked */
1796#define EXT4_MMP_SEQ_MAX   0xE24D4D4FU /* maximum valid mmp_seq value */
1797
1798struct mmp_struct {
1799        __le32  mmp_magic;              /* Magic number for MMP */
1800        __le32  mmp_seq;                /* Sequence no. updated periodically */
1801
1802        /*
1803         * mmp_time, mmp_nodename & mmp_bdevname are only used for information
1804         * purposes and do not affect the correctness of the algorithm
1805         */
1806        __le64  mmp_time;               /* Time last updated */
1807        char    mmp_nodename[64];       /* Node which last updated MMP block */
1808        char    mmp_bdevname[32];       /* Bdev which last updated MMP block */
1809
1810        /*
1811         * mmp_check_interval is used to verify if the MMP block has been
1812         * updated on the block device. The value is updated based on the
1813         * maximum time to write the MMP block during an update cycle.
1814         */
1815        __le16  mmp_check_interval;
1816
1817        __le16  mmp_pad1;
1818        __le32  mmp_pad2[226];
1819        __le32  mmp_checksum;           /* crc32c(uuid+mmp_block) */
1820};
1821
1822/* arguments passed to the mmp thread */
1823struct mmpd_data {
1824        struct buffer_head *bh; /* bh from initial read_mmp_block() */
1825        struct super_block *sb;  /* super block of the fs */
1826};
1827
1828/*
1829 * Check interval multiplier
1830 * The MMP block is written every update interval and initially checked every
1831 * update interval x the multiplier (the value is then adapted based on the
1832 * write latency). The reason is that writes can be delayed under load and we
1833 * don't want readers to incorrectly assume that the filesystem is no longer
1834 * in use.
1835 */
1836#define EXT4_MMP_CHECK_MULT             2UL
1837
1838/*
1839 * Minimum interval for MMP checking in seconds.
1840 */
1841#define EXT4_MMP_MIN_CHECK_INTERVAL     5UL
1842
1843/*
1844 * Maximum interval for MMP checking in seconds.
1845 */
1846#define EXT4_MMP_MAX_CHECK_INTERVAL     300UL
1847
1848/*
1849 * Function prototypes
1850 */
1851
1852/*
1853 * Ok, these declarations are also in <linux/kernel.h> but none of the
1854 * ext4 source programs needs to include it so they are duplicated here.
1855 */
1856# define NORET_TYPE     /**/
1857# define ATTRIB_NORET   __attribute__((noreturn))
1858# define NORET_AND      noreturn,
1859
1860/* bitmap.c */
1861extern unsigned int ext4_count_free(char *bitmap, unsigned numchars);
1862void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1863                                struct ext4_group_desc *gdp,
1864                                struct buffer_head *bh, int sz);
1865int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1866                                  struct ext4_group_desc *gdp,
1867                                  struct buffer_head *bh, int sz);
1868void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1869                                struct ext4_group_desc *gdp,
1870                                struct buffer_head *bh);
1871int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1872                                  struct ext4_group_desc *gdp,
1873                                  struct buffer_head *bh);
1874
1875/* balloc.c */
1876extern void ext4_validate_block_bitmap(struct super_block *sb,
1877                                       struct ext4_group_desc *desc,
1878                                       unsigned int block_group,
1879                                       struct buffer_head *bh);
1880extern unsigned int ext4_block_group(struct super_block *sb,
1881                        ext4_fsblk_t blocknr);
1882extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1883                        ext4_fsblk_t blocknr);
1884extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1885extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1886                        ext4_group_t group);
1887extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1888                                         ext4_fsblk_t goal,
1889                                         unsigned int flags,
1890                                         unsigned long *count,
1891                                         int *errp);
1892extern int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
1893                                    s64 nclusters, unsigned int flags);
1894extern ext4_fsblk_t ext4_count_free_clusters(struct super_block *);
1895extern void ext4_check_blocks_bitmap(struct super_block *);
1896extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1897                                                    ext4_group_t block_group,
1898                                                    struct buffer_head ** bh);
1899extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1900
1901extern struct buffer_head *ext4_read_block_bitmap_nowait(struct super_block *sb,
1902                                                ext4_group_t block_group);
1903extern int ext4_wait_block_bitmap(struct super_block *sb,
1904                                  ext4_group_t block_group,
1905                                  struct buffer_head *bh);
1906extern struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1907                                                  ext4_group_t block_group);
1908extern void ext4_init_block_bitmap(struct super_block *sb,
1909                                   struct buffer_head *bh,
1910                                   ext4_group_t group,
1911                                   struct ext4_group_desc *desc);
1912extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
1913                                              ext4_group_t block_group,
1914                                              struct ext4_group_desc *gdp);
1915extern unsigned ext4_num_overhead_clusters(struct super_block *sb,
1916                                           ext4_group_t block_group,
1917                                           struct ext4_group_desc *gdp);
1918ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
1919
1920/* dir.c */
1921extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
1922                                  struct file *,
1923                                  struct ext4_dir_entry_2 *,
1924                                  struct buffer_head *, unsigned int);
1925#define ext4_check_dir_entry(dir, filp, de, bh, offset)                 \
1926        unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
1927                                        (de), (bh), (offset)))
1928extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1929                                    __u32 minor_hash,
1930                                    struct ext4_dir_entry_2 *dirent);
1931extern void ext4_htree_free_dir_info(struct dir_private_info *p);
1932
1933/* fsync.c */
1934extern int ext4_sync_file(struct file *, loff_t, loff_t, int);
1935extern int ext4_flush_completed_IO(struct inode *);
1936
1937/* hash.c */
1938extern int ext4fs_dirhash(const char *name, int len, struct
1939                          dx_hash_info *hinfo);
1940
1941/* ialloc.c */
1942extern struct inode *ext4_new_inode(handle_t *, struct inode *, umode_t,
1943                                    const struct qstr *qstr, __u32 goal,
1944                                    uid_t *owner);
1945extern void ext4_free_inode(handle_t *, struct inode *);
1946extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
1947extern unsigned long ext4_count_free_inodes(struct super_block *);
1948extern unsigned long ext4_count_dirs(struct super_block *);
1949extern void ext4_check_inodes_bitmap(struct super_block *);
1950extern void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
1951extern int ext4_init_inode_table(struct super_block *sb,
1952                                 ext4_group_t group, int barrier);
1953extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
1954
1955/* mballoc.c */
1956extern long ext4_mb_stats;
1957extern long ext4_mb_max_to_scan;
1958extern int ext4_mb_init(struct super_block *);
1959extern int ext4_mb_release(struct super_block *);
1960extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
1961                                struct ext4_allocation_request *, int *);
1962extern int ext4_mb_reserve_blocks(struct super_block *, int);
1963extern void ext4_discard_preallocations(struct inode *);
1964extern int __init ext4_init_mballoc(void);
1965extern void ext4_exit_mballoc(void);
1966extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
1967                             struct buffer_head *bh, ext4_fsblk_t block,
1968                             unsigned long count, int flags);
1969extern int ext4_mb_add_groupinfo(struct super_block *sb,
1970                ext4_group_t i, struct ext4_group_desc *desc);
1971extern int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
1972                                ext4_fsblk_t block, unsigned long count);
1973extern int ext4_trim_fs(struct super_block *, struct fstrim_range *);
1974
1975/* inode.c */
1976struct buffer_head *ext4_getblk(handle_t *, struct inode *,
1977                                                ext4_lblk_t, int, int *);
1978struct buffer_head *ext4_bread(handle_t *, struct inode *,
1979                                                ext4_lblk_t, int, int *);
1980int ext4_get_block(struct inode *inode, sector_t iblock,
1981                                struct buffer_head *bh_result, int create);
1982
1983extern struct inode *ext4_iget(struct super_block *, unsigned long);
1984extern int  ext4_write_inode(struct inode *, struct writeback_control *);
1985extern int  ext4_setattr(struct dentry *, struct iattr *);
1986extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
1987                                struct kstat *stat);
1988extern void ext4_evict_inode(struct inode *);
1989extern void ext4_clear_inode(struct inode *);
1990extern int  ext4_sync_inode(handle_t *, struct inode *);
1991extern void ext4_dirty_inode(struct inode *, int);
1992extern int ext4_change_inode_journal_flag(struct inode *, int);
1993extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
1994extern int ext4_can_truncate(struct inode *inode);
1995extern void ext4_truncate(struct inode *);
1996extern int ext4_punch_hole(struct file *file, loff_t offset, loff_t length);
1997extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
1998extern void ext4_set_inode_flags(struct inode *);
1999extern void ext4_get_inode_flags(struct ext4_inode_info *);
2000extern int ext4_alloc_da_blocks(struct inode *inode);
2001extern void ext4_set_aops(struct inode *inode);
2002extern int ext4_writepage_trans_blocks(struct inode *);
2003extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
2004extern int ext4_discard_partial_page_buffers(handle_t *handle,
2005                struct address_space *mapping, loff_t from,
2006                loff_t length, int flags);
2007extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
2008extern qsize_t *ext4_get_reserved_space(struct inode *inode);
2009extern void ext4_da_update_reserve_space(struct inode *inode,
2010                                        int used, int quota_claim);
2011
2012/* indirect.c */
2013extern int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
2014                                struct ext4_map_blocks *map, int flags);
2015extern ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb,
2016                                const struct iovec *iov, loff_t offset,
2017                                unsigned long nr_segs);
2018extern int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock);
2019extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks, int chunk);
2020extern void ext4_ind_truncate(struct inode *inode);
2021
2022/* ioctl.c */
2023extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
2024extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
2025
2026/* migrate.c */
2027extern int ext4_ext_migrate(struct inode *);
2028
2029/* namei.c */
2030extern int ext4_dirent_csum_verify(struct inode *inode,
2031                                   struct ext4_dir_entry *dirent);
2032extern int ext4_orphan_add(handle_t *, struct inode *);
2033extern int ext4_orphan_del(handle_t *, struct inode *);
2034extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
2035                                __u32 start_minor_hash, __u32 *next_hash);
2036
2037/* resize.c */
2038extern int ext4_group_add(struct super_block *sb,
2039                                struct ext4_new_group_data *input);
2040extern int ext4_group_extend(struct super_block *sb,
2041                                struct ext4_super_block *es,
2042                                ext4_fsblk_t n_blocks_count);
2043extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
2044
2045/* super.c */
2046extern int ext4_calculate_overhead(struct super_block *sb);
2047extern int ext4_superblock_csum_verify(struct super_block *sb,
2048                                       struct ext4_super_block *es);
2049extern void ext4_superblock_csum_set(struct super_block *sb,
2050                                     struct ext4_super_block *es);
2051extern void *ext4_kvmalloc(size_t size, gfp_t flags);
2052extern void *ext4_kvzalloc(size_t size, gfp_t flags);
2053extern void ext4_kvfree(void *ptr);
2054extern __printf(4, 5)
2055void __ext4_error(struct super_block *, const char *, unsigned int,
2056                  const char *, ...);
2057#define ext4_error(sb, message...)      __ext4_error(sb, __func__,      \
2058                                                     __LINE__, ## message)
2059extern __printf(5, 6)
2060void ext4_error_inode(struct inode *, const char *, unsigned int, ext4_fsblk_t,
2061                      const char *, ...);
2062extern __printf(5, 6)
2063void ext4_error_file(struct file *, const char *, unsigned int, ext4_fsblk_t,
2064                     const char *, ...);
2065extern void __ext4_std_error(struct super_block *, const char *,
2066                             unsigned int, int);
2067extern __printf(4, 5)
2068void __ext4_abort(struct super_block *, const char *, unsigned int,
2069                  const char *, ...);
2070#define ext4_abort(sb, message...)      __ext4_abort(sb, __func__, \
2071                                                       __LINE__, ## message)
2072extern __printf(4, 5)
2073void __ext4_warning(struct super_block *, const char *, unsigned int,
2074                    const char *, ...);
2075#define ext4_warning(sb, message...)    __ext4_warning(sb, __func__, \
2076                                                       __LINE__, ## message)
2077extern __printf(3, 4)
2078void ext4_msg(struct super_block *, const char *, const char *, ...);
2079extern void __dump_mmp_msg(struct super_block *, struct mmp_struct *mmp,
2080                           const char *, unsigned int, const char *);
2081#define dump_mmp_msg(sb, mmp, msg)      __dump_mmp_msg(sb, mmp, __func__, \
2082                                                       __LINE__, msg)
2083extern __printf(7, 8)
2084void __ext4_grp_locked_error(const char *, unsigned int,
2085                             struct super_block *, ext4_group_t,
2086                             unsigned long, ext4_fsblk_t,
2087                             const char *, ...);
2088#define ext4_grp_locked_error(sb, grp, message...) \
2089        __ext4_grp_locked_error(__func__, __LINE__, (sb), (grp), ## message)
2090extern void ext4_update_dynamic_rev(struct super_block *sb);
2091extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
2092                                        __u32 compat);
2093extern int ext4_update_rocompat_feature(handle_t *handle,
2094                                        struct super_block *sb, __u32 rocompat);
2095extern int ext4_update_incompat_feature(handle_t *handle,
2096                                        struct super_block *sb, __u32 incompat);
2097extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
2098                                      struct ext4_group_desc *bg);
2099extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
2100                                      struct ext4_group_desc *bg);
2101extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
2102                                     struct ext4_group_desc *bg);
2103extern __u32 ext4_free_group_clusters(struct super_block *sb,
2104                                      struct ext4_group_desc *bg);
2105extern __u32 ext4_free_inodes_count(struct super_block *sb,
2106                                 struct ext4_group_desc *bg);
2107extern __u32 ext4_used_dirs_count(struct super_block *sb,
2108                                struct ext4_group_desc *bg);
2109extern __u32 ext4_itable_unused_count(struct super_block *sb,
2110                                   struct ext4_group_desc *bg);
2111extern void ext4_block_bitmap_set(struct super_block *sb,
2112                                  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2113extern void ext4_inode_bitmap_set(struct super_block *sb,
2114                                  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2115extern void ext4_inode_table_set(struct super_block *sb,
2116                                 struct ext4_group_desc *bg, ext4_fsblk_t blk);
2117extern void ext4_free_group_clusters_set(struct super_block *sb,
2118                                         struct ext4_group_desc *bg,
2119                                         __u32 count);
2120extern void ext4_free_inodes_set(struct super_block *sb,
2121                                struct ext4_group_desc *bg, __u32 count);
2122extern void ext4_used_dirs_set(struct super_block *sb,
2123                                struct ext4_group_desc *bg, __u32 count);
2124extern void ext4_itable_unused_set(struct super_block *sb,
2125                                   struct ext4_group_desc *bg, __u32 count);
2126extern int ext4_group_desc_csum_verify(struct super_block *sb, __u32 group,
2127                                       struct ext4_group_desc *gdp);
2128extern void ext4_group_desc_csum_set(struct super_block *sb, __u32 group,
2129                                     struct ext4_group_desc *gdp);
2130
2131static inline int ext4_has_group_desc_csum(struct super_block *sb)
2132{
2133        return EXT4_HAS_RO_COMPAT_FEATURE(sb,
2134                                          EXT4_FEATURE_RO_COMPAT_GDT_CSUM |
2135                                          EXT4_FEATURE_RO_COMPAT_METADATA_CSUM);
2136}
2137
2138static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
2139{
2140        return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
2141                le32_to_cpu(es->s_blocks_count_lo);
2142}
2143
2144static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
2145{
2146        return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
2147                le32_to_cpu(es->s_r_blocks_count_lo);
2148}
2149
2150static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
2151{
2152        return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
2153                le32_to_cpu(es->s_free_blocks_count_lo);
2154}
2155
2156static inline void ext4_blocks_count_set(struct ext4_super_block *es,
2157                                         ext4_fsblk_t blk)
2158{
2159        es->s_blocks_count_lo = cpu_to_le32((u32)blk);
2160        es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
2161}
2162
2163static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
2164                                              ext4_fsblk_t blk)
2165{
2166        es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
2167        es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
2168}
2169
2170static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
2171                                           ext4_fsblk_t blk)
2172{
2173        es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
2174        es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
2175}
2176
2177static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
2178{
2179        if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
2180                return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
2181                        le32_to_cpu(raw_inode->i_size_lo);
2182        else
2183                return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
2184}
2185
2186static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
2187{
2188        raw_inode->i_size_lo = cpu_to_le32(i_size);
2189        raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
2190}
2191
2192static inline
2193struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
2194                                            ext4_group_t group)
2195{
2196         struct ext4_group_info ***grp_info;
2197         long indexv, indexh;
2198         grp_info = EXT4_SB(sb)->s_group_info;
2199         indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
2200         indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
2201         return grp_info[indexv][indexh];
2202}
2203
2204/*
2205 * Reading s_groups_count requires using smp_rmb() afterwards.  See
2206 * the locking protocol documented in the comments of ext4_group_add()
2207 * in resize.c
2208 */
2209static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
2210{
2211        ext4_group_t    ngroups = EXT4_SB(sb)->s_groups_count;
2212
2213        smp_rmb();
2214        return ngroups;
2215}
2216
2217static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
2218                                             ext4_group_t block_group)
2219{
2220        return block_group >> sbi->s_log_groups_per_flex;
2221}
2222
2223static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
2224{
2225        return 1 << sbi->s_log_groups_per_flex;
2226}
2227
2228#define ext4_std_error(sb, errno)                               \
2229do {                                                            \
2230        if ((errno))                                            \
2231                __ext4_std_error((sb), __func__, __LINE__, (errno));    \
2232} while (0)
2233
2234#ifdef CONFIG_SMP
2235/* Each CPU can accumulate percpu_counter_batch clusters in their local
2236 * counters. So we need to make sure we have free clusters more
2237 * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
2238 */
2239#define EXT4_FREECLUSTERS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
2240#else
2241#define EXT4_FREECLUSTERS_WATERMARK 0
2242#endif
2243
2244static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
2245{
2246        /*
2247         * XXX: replace with spinlock if seen contended -bzzz
2248         */
2249        down_write(&EXT4_I(inode)->i_data_sem);
2250        if (newsize > EXT4_I(inode)->i_disksize)
2251                EXT4_I(inode)->i_disksize = newsize;
2252        up_write(&EXT4_I(inode)->i_data_sem);
2253        return ;
2254}
2255
2256struct ext4_group_info {
2257        unsigned long   bb_state;
2258        struct rb_root  bb_free_root;
2259        ext4_grpblk_t   bb_first_free;  /* first free block */
2260        ext4_grpblk_t   bb_free;        /* total free blocks */
2261        ext4_grpblk_t   bb_fragments;   /* nr of freespace fragments */
2262        ext4_grpblk_t   bb_largest_free_order;/* order of largest frag in BG */
2263        struct          list_head bb_prealloc_list;
2264#ifdef DOUBLE_CHECK
2265        void            *bb_bitmap;
2266#endif
2267        struct rw_semaphore alloc_sem;
2268        ext4_grpblk_t   bb_counters[];  /* Nr of free power-of-two-block
2269                                         * regions, index is order.
2270                                         * bb_counters[3] = 5 means
2271                                         * 5 free 8-block regions. */
2272};
2273
2274#define EXT4_GROUP_INFO_NEED_INIT_BIT           0
2275#define EXT4_GROUP_INFO_WAS_TRIMMED_BIT         1
2276
2277#define EXT4_MB_GRP_NEED_INIT(grp)      \
2278        (test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
2279
2280#define EXT4_MB_GRP_WAS_TRIMMED(grp)    \
2281        (test_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2282#define EXT4_MB_GRP_SET_TRIMMED(grp)    \
2283        (set_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2284#define EXT4_MB_GRP_CLEAR_TRIMMED(grp)  \
2285        (clear_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2286
2287#define EXT4_MAX_CONTENTION             8
2288#define EXT4_CONTENTION_THRESHOLD       2
2289
2290static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
2291                                              ext4_group_t group)
2292{
2293        return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
2294}
2295
2296/*
2297 * Returns true if the filesystem is busy enough that attempts to
2298 * access the block group locks has run into contention.
2299 */
2300static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
2301{
2302        return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
2303}
2304
2305static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
2306{
2307        spinlock_t *lock = ext4_group_lock_ptr(sb, group);
2308        if (spin_trylock(lock))
2309                /*
2310                 * We're able to grab the lock right away, so drop the
2311                 * lock contention counter.
2312                 */
2313                atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
2314        else {
2315                /*
2316                 * The lock is busy, so bump the contention counter,
2317                 * and then wait on the spin lock.
2318                 */
2319                atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
2320                                  EXT4_MAX_CONTENTION);
2321                spin_lock(lock);
2322        }
2323}
2324
2325static inline void ext4_unlock_group(struct super_block *sb,
2326                                        ext4_group_t group)
2327{
2328        spin_unlock(ext4_group_lock_ptr(sb, group));
2329}
2330
2331/*
2332 * Block validity checking
2333 */
2334#define ext4_check_indirect_blockref(inode, bh)                         \
2335        ext4_check_blockref(__func__, __LINE__, inode,                  \
2336                            (__le32 *)(bh)->b_data,                     \
2337                            EXT4_ADDR_PER_BLOCK((inode)->i_sb))
2338
2339#define ext4_ind_check_inode(inode)                                     \
2340        ext4_check_blockref(__func__, __LINE__, inode,                  \
2341                            EXT4_I(inode)->i_data,                      \
2342                            EXT4_NDIR_BLOCKS)
2343
2344/*
2345 * Inodes and files operations
2346 */
2347
2348/* dir.c */
2349extern const struct file_operations ext4_dir_operations;
2350
2351/* file.c */
2352extern const struct inode_operations ext4_file_inode_operations;
2353extern const struct file_operations ext4_file_operations;
2354extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
2355
2356/* namei.c */
2357extern const struct inode_operations ext4_dir_inode_operations;
2358extern const struct inode_operations ext4_special_inode_operations;
2359extern struct dentry *ext4_get_parent(struct dentry *child);
2360
2361/* symlink.c */
2362extern const struct inode_operations ext4_symlink_inode_operations;
2363extern const struct inode_operations ext4_fast_symlink_inode_operations;
2364
2365/* block_validity */
2366extern void ext4_release_system_zone(struct super_block *sb);
2367extern int ext4_setup_system_zone(struct super_block *sb);
2368extern int __init ext4_init_system_zone(void);
2369extern void ext4_exit_system_zone(void);
2370extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
2371                                 ext4_fsblk_t start_blk,
2372                                 unsigned int count);
2373extern int ext4_check_blockref(const char *, unsigned int,
2374                               struct inode *, __le32 *, unsigned int);
2375
2376/* extents.c */
2377extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
2378extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
2379extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks,
2380                                       int chunk);
2381extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
2382                               struct ext4_map_blocks *map, int flags);
2383extern void ext4_ext_truncate(struct inode *);
2384extern int ext4_ext_punch_hole(struct file *file, loff_t offset,
2385                                loff_t length);
2386extern void ext4_ext_init(struct super_block *);
2387extern void ext4_ext_release(struct super_block *);
2388extern long ext4_fallocate(struct file *file, int mode, loff_t offset,
2389                          loff_t len);
2390extern int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
2391                          ssize_t len);
2392extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
2393                           struct ext4_map_blocks *map, int flags);
2394extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
2395                        __u64 start, __u64 len);
2396/* move_extent.c */
2397extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
2398                             __u64 start_orig, __u64 start_donor,
2399                             __u64 len, __u64 *moved_len);
2400
2401/* page-io.c */
2402extern int __init ext4_init_pageio(void);
2403extern void ext4_exit_pageio(void);
2404extern void ext4_ioend_wait(struct inode *);
2405extern void ext4_free_io_end(ext4_io_end_t *io);
2406extern ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags);
2407extern int ext4_end_io_nolock(ext4_io_end_t *io);
2408extern void ext4_io_submit(struct ext4_io_submit *io);
2409extern int ext4_bio_write_page(struct ext4_io_submit *io,
2410                               struct page *page,
2411                               int len,
2412                               struct writeback_control *wbc);
2413
2414/* mmp.c */
2415extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
2416extern void ext4_mmp_csum_set(struct super_block *sb, struct mmp_struct *mmp);
2417extern int ext4_mmp_csum_verify(struct super_block *sb,
2418                                struct mmp_struct *mmp);
2419
2420/* BH_Uninit flag: blocks are allocated but uninitialized on disk */
2421enum ext4_state_bits {
2422        BH_Uninit       /* blocks are allocated but uninitialized on disk */
2423          = BH_JBDPrivateStart,
2424        BH_AllocFromCluster,    /* allocated blocks were part of already
2425                                 * allocated cluster. Note that this flag will
2426                                 * never, ever appear in a buffer_head's state
2427                                 * flag. See EXT4_MAP_FROM_CLUSTER to see where
2428                                 * this is used. */
2429        BH_Da_Mapped,   /* Delayed allocated block that now has a mapping. This
2430                         * flag is set when ext4_map_blocks is called on a
2431                         * delayed allocated block to get its real mapping. */
2432};
2433
2434BUFFER_FNS(Uninit, uninit)
2435TAS_BUFFER_FNS(Uninit, uninit)
2436BUFFER_FNS(Da_Mapped, da_mapped)
2437
2438/*
2439 * Add new method to test wether block and inode bitmaps are properly
2440 * initialized. With uninit_bg reading the block from disk is not enough
2441 * to mark the bitmap uptodate. We need to also zero-out the bitmap
2442 */
2443#define BH_BITMAP_UPTODATE BH_JBDPrivateStart
2444
2445static inline int bitmap_uptodate(struct buffer_head *bh)
2446{
2447        return (buffer_uptodate(bh) &&
2448                        test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
2449}
2450static inline void set_bitmap_uptodate(struct buffer_head *bh)
2451{
2452        set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
2453}
2454
2455#define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
2456
2457/* For ioend & aio unwritten conversion wait queues */
2458#define EXT4_WQ_HASH_SZ         37
2459#define ext4_ioend_wq(v)   (&ext4__ioend_wq[((unsigned long)(v)) %\
2460                                            EXT4_WQ_HASH_SZ])
2461#define ext4_aio_mutex(v)  (&ext4__aio_mutex[((unsigned long)(v)) %\
2462                                             EXT4_WQ_HASH_SZ])
2463extern wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
2464extern struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
2465
2466#define EXT4_RESIZING   0
2467extern int ext4_resize_begin(struct super_block *sb);
2468extern void ext4_resize_end(struct super_block *sb);
2469
2470#endif  /* __KERNEL__ */
2471
2472#include "ext4_extents.h"
2473
2474#endif  /* _EXT4_H */
2475
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