Pileus Git - ~andy/linux/blob - fs/ext4/ext4.h

   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 /*
  61  * Turn on EXT_DEBUG to get lots of info about extents operations.
  62  */
  63 #define EXT_DEBUG__
  64 #ifdef EXT_DEBUG
  65 #define ext_debug(fmt, ...)     printk(fmt, ##__VA_ARGS__)
  66 #else
  67 #define ext_debug(fmt, ...)     no_printk(fmt, ##__VA_ARGS__)
  68 #endif
  69
  70 #define EXT4_ERROR_INODE(inode, fmt, a...) \
  71         ext4_error_inode((inode), __func__, __LINE__, 0, (fmt), ## a)
  72
  73 #define EXT4_ERROR_INODE_BLOCK(inode, block, fmt, a...)                 \
  74         ext4_error_inode((inode), __func__, __LINE__, (block), (fmt), ## a)
  75
  76 #define EXT4_ERROR_FILE(file, block, fmt, a...)                         \
  77         ext4_error_file((file), __func__, __LINE__, (block), (fmt), ## a)
  78
  79 /* data type for block offset of block group */
  80 typedef int ext4_grpblk_t;
  81
  82 /* data type for filesystem-wide blocks number */
  83 typedef unsigned long long ext4_fsblk_t;
  84
  85 /* data type for file logical block number */
  86 typedef __u32 ext4_lblk_t;
  87
  88 /* data type for block group number */
  89 typedef unsigned int ext4_group_t;
  90
  91 /*
  92  * Flags used in mballoc's allocation_context flags field.
  93  *
  94  * Also used to show what's going on for debugging purposes when the
  95  * flag field is exported via the traceport interface
  96  */
  97
  98 /* prefer goal again. length */
  99 #define EXT4_MB_HINT_MERGE              0x0001
 100 /* blocks already reserved */
 101 #define EXT4_MB_HINT_RESERVED           0x0002
 102 /* metadata is being allocated */
 103 #define EXT4_MB_HINT_METADATA           0x0004
 104 /* first blocks in the file */
 105 #define EXT4_MB_HINT_FIRST              0x0008
 106 /* search for the best chunk */
 107 #define EXT4_MB_HINT_BEST               0x0010
 108 /* data is being allocated */
 109 #define EXT4_MB_HINT_DATA               0x0020
 110 /* don't preallocate (for tails) */
 111 #define EXT4_MB_HINT_NOPREALLOC         0x0040
 112 /* allocate for locality group */
 113 #define EXT4_MB_HINT_GROUP_ALLOC        0x0080
 114 /* allocate goal blocks or none */
 115 #define EXT4_MB_HINT_GOAL_ONLY          0x0100
 116 /* goal is meaningful */
 117 #define EXT4_MB_HINT_TRY_GOAL           0x0200
 118 /* blocks already pre-reserved by delayed allocation */
 119 #define EXT4_MB_DELALLOC_RESERVED       0x0400
 120 /* We are doing stream allocation */
 121 #define EXT4_MB_STREAM_ALLOC            0x0800
 122 /* Use reserved root blocks if needed */
 123 #define EXT4_MB_USE_ROOT_BLOCKS         0x1000
 124 /* Use blocks from reserved pool */
 125 #define EXT4_MB_USE_RESERVED            0x2000
 126
 127 struct ext4_allocation_request {
 128         /* target inode for block we're allocating */
 129         struct inode *inode;
 130         /* how many blocks we want to allocate */
 131         unsigned int len;
 132         /* logical block in target inode */
 133         ext4_lblk_t logical;
 134         /* the closest logical allocated block to the left */
 135         ext4_lblk_t lleft;
 136         /* the closest logical allocated block to the right */
 137         ext4_lblk_t lright;
 138         /* phys. target (a hint) */
 139         ext4_fsblk_t goal;
 140         /* phys. block for the closest logical allocated block to the left */
 141         ext4_fsblk_t pleft;
 142         /* phys. block for the closest logical allocated block to the right */
 143         ext4_fsblk_t pright;
 144         /* flags. see above EXT4_MB_HINT_* */
 145         unsigned int flags;
 146 };
 147
 148 /*
 149  * Logical to physical block mapping, used by ext4_map_blocks()
 150  *
 151  * This structure is used to pass requests into ext4_map_blocks() as
 152  * well as to store the information returned by ext4_map_blocks().  It
 153  * takes less room on the stack than a struct buffer_head.
 154  */
 155 #define EXT4_MAP_NEW            (1 << BH_New)
 156 #define EXT4_MAP_MAPPED         (1 << BH_Mapped)
 157 #define EXT4_MAP_UNWRITTEN      (1 << BH_Unwritten)
 158 #define EXT4_MAP_BOUNDARY       (1 << BH_Boundary)
 159 #define EXT4_MAP_UNINIT         (1 << BH_Uninit)
 160 /* Sometimes (in the bigalloc case, from ext4_da_get_block_prep) the caller of
 161  * ext4_map_blocks wants to know whether or not the underlying cluster has
 162  * already been accounted for. EXT4_MAP_FROM_CLUSTER conveys to the caller that
 163  * the requested mapping was from previously mapped (or delayed allocated)
 164  * cluster. We use BH_AllocFromCluster only for this flag. BH_AllocFromCluster
 165  * should never appear on buffer_head's state flags.
 166  */
 167 #define EXT4_MAP_FROM_CLUSTER   (1 << BH_AllocFromCluster)
 168 #define EXT4_MAP_FLAGS          (EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
 169                                  EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY |\
 170                                  EXT4_MAP_UNINIT | EXT4_MAP_FROM_CLUSTER)
 171
 172 struct ext4_map_blocks {
 173         ext4_fsblk_t m_pblk;
 174         ext4_lblk_t m_lblk;
 175         unsigned int m_len;
 176         unsigned int m_flags;
 177 };
 178
 179 /*
 180  * For delayed allocation tracking
 181  */
 182 struct mpage_da_data {
 183         struct inode *inode;
 184         sector_t b_blocknr;             /* start block number of extent */
 185         size_t b_size;                  /* size of extent */
 186         unsigned long b_state;          /* state of the extent */
 187         unsigned long first_page, next_page;    /* extent of pages */
 188         struct writeback_control *wbc;
 189         int io_done;
 190         int pages_written;
 191         int retval;
 192 };
 193
 194 /*
 195  * Flags for ext4_io_end->flags
 196  */
 197 #define EXT4_IO_END_UNWRITTEN   0x0001
 198 #define EXT4_IO_END_ERROR       0x0002
 199 #define EXT4_IO_END_DIRECT      0x0004
 200
 201 /*
 202  * For converting uninitialized extents on a work queue.
 203  */
 204 typedef struct ext4_io_end {
 205         struct list_head        list;           /* per-file finished IO list */
 206         struct inode            *inode;         /* file being written to */
 207         unsigned int            flag;           /* unwritten or not */
 208         loff_t                  offset;         /* offset in the file */
 209         ssize_t                 size;           /* size of the extent */
 210         struct kiocb            *iocb;          /* iocb struct for AIO */
 211         int                     result;         /* error value for AIO */
 212         atomic_t                count;          /* reference counter */
 213 } ext4_io_end_t;
 214
 215 struct ext4_io_submit {
 216         int                     io_op;
 217         struct bio              *io_bio;
 218         ext4_io_end_t           *io_end;
 219         sector_t                io_next_block;
 220 };
 221
 222 /*
 223  * Special inodes numbers
 224  */
 225 #define EXT4_BAD_INO             1      /* Bad blocks inode */
 226 #define EXT4_ROOT_INO            2      /* Root inode */
 227 #define EXT4_USR_QUOTA_INO       3      /* User quota inode */
 228 #define EXT4_GRP_QUOTA_INO       4      /* Group quota inode */
 229 #define EXT4_BOOT_LOADER_INO     5      /* Boot loader inode */
 230 #define EXT4_UNDEL_DIR_INO       6      /* Undelete directory inode */
 231 #define EXT4_RESIZE_INO          7      /* Reserved group descriptors inode */
 232 #define EXT4_JOURNAL_INO         8      /* Journal inode */
 233
 234 /* First non-reserved inode for old ext4 filesystems */
 235 #define EXT4_GOOD_OLD_FIRST_INO 11
 236
 237 /*
 238  * Maximal count of links to a file
 239  */
 240 #define EXT4_LINK_MAX           65000
 241
 242 /*
 243  * Macro-instructions used to manage several block sizes
 244  */
 245 #define EXT4_MIN_BLOCK_SIZE             1024
 246 #define EXT4_MAX_BLOCK_SIZE             65536
 247 #define EXT4_MIN_BLOCK_LOG_SIZE         10
 248 #define EXT4_MAX_BLOCK_LOG_SIZE         16
 249 #ifdef __KERNEL__
 250 # define EXT4_BLOCK_SIZE(s)             ((s)->s_blocksize)
 251 #else
 252 # define EXT4_BLOCK_SIZE(s)             (EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
 253 #endif
 254 #define EXT4_ADDR_PER_BLOCK(s)          (EXT4_BLOCK_SIZE(s) / sizeof(__u32))
 255 #define EXT4_CLUSTER_SIZE(s)            (EXT4_BLOCK_SIZE(s) << \
 256                                          EXT4_SB(s)->s_cluster_bits)
 257 #ifdef __KERNEL__
 258 # define EXT4_BLOCK_SIZE_BITS(s)        ((s)->s_blocksize_bits)
 259 # define EXT4_CLUSTER_BITS(s)           (EXT4_SB(s)->s_cluster_bits)
 260 #else
 261 # define EXT4_BLOCK_SIZE_BITS(s)        ((s)->s_log_block_size + 10)
 262 #endif
 263 #ifdef __KERNEL__
 264 #define EXT4_ADDR_PER_BLOCK_BITS(s)     (EXT4_SB(s)->s_addr_per_block_bits)
 265 #define EXT4_INODE_SIZE(s)              (EXT4_SB(s)->s_inode_size)
 266 #define EXT4_FIRST_INO(s)               (EXT4_SB(s)->s_first_ino)
 267 #else
 268 #define EXT4_INODE_SIZE(s)      (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
 269                                  EXT4_GOOD_OLD_INODE_SIZE : \
 270                                  (s)->s_inode_size)
 271 #define EXT4_FIRST_INO(s)       (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
 272                                  EXT4_GOOD_OLD_FIRST_INO : \
 273                                  (s)->s_first_ino)
 274 #endif
 275 #define EXT4_BLOCK_ALIGN(size, blkbits)         ALIGN((size), (1 << (blkbits)))
 276
 277 /* Translate a block number to a cluster number */
 278 #define EXT4_B2C(sbi, blk)      ((blk) >> (sbi)->s_cluster_bits)
 279 /* Translate a cluster number to a block number */
 280 #define EXT4_C2B(sbi, cluster)  ((cluster) << (sbi)->s_cluster_bits)
 281 /* Translate # of blks to # of clusters */
 282 #define EXT4_NUM_B2C(sbi, blks) (((blks) + (sbi)->s_cluster_ratio - 1) >> \
 283                                  (sbi)->s_cluster_bits)
 284
 285 /*
 286  * Structure of a blocks group descriptor
 287  */
 288 struct ext4_group_desc
 289 {
 290         __le32  bg_block_bitmap_lo;     /* Blocks bitmap block */
 291         __le32  bg_inode_bitmap_lo;     /* Inodes bitmap block */
 292         __le32  bg_inode_table_lo;      /* Inodes table block */
 293         __le16  bg_free_blocks_count_lo;/* Free blocks count */
 294         __le16  bg_free_inodes_count_lo;/* Free inodes count */
 295         __le16  bg_used_dirs_count_lo;  /* Directories count */
 296         __le16  bg_flags;               /* EXT4_BG_flags (INODE_UNINIT, etc) */
 297         __le32  bg_exclude_bitmap_lo;   /* Exclude bitmap for snapshots */
 298         __le16  bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bbitmap) LE */
 299         __le16  bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+ibitmap) LE */
 300         __le16  bg_itable_unused_lo;    /* Unused inodes count */
 301         __le16  bg_checksum;            /* crc16(sb_uuid+group+desc) */
 302         __le32  bg_block_bitmap_hi;     /* Blocks bitmap block MSB */
 303         __le32  bg_inode_bitmap_hi;     /* Inodes bitmap block MSB */
 304         __le32  bg_inode_table_hi;      /* Inodes table block MSB */
 305         __le16  bg_free_blocks_count_hi;/* Free blocks count MSB */
 306         __le16  bg_free_inodes_count_hi;/* Free inodes count MSB */
 307         __le16  bg_used_dirs_count_hi;  /* Directories count MSB */
 308         __le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
 309         __le32  bg_exclude_bitmap_hi;   /* Exclude bitmap block MSB */
 310         __le16  bg_block_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bbitmap) BE */
 311         __le16  bg_inode_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+ibitmap) BE */
 312         __u32   bg_reserved;
 313 };
 314
 315 #define EXT4_BG_INODE_BITMAP_CSUM_HI_END        \
 316         (offsetof(struct ext4_group_desc, bg_inode_bitmap_csum_hi) + \
 317          sizeof(__le16))
 318 #define EXT4_BG_BLOCK_BITMAP_CSUM_HI_END        \
 319         (offsetof(struct ext4_group_desc, bg_block_bitmap_csum_hi) + \
 320          sizeof(__le16))
 321
 322 /*
 323  * Structure of a flex block group info
 324  */
 325
 326 struct flex_groups {
 327         atomic64_t      free_clusters;
 328         atomic_t        free_inodes;
 329         atomic_t        used_dirs;
 330 };
 331
 332 #define EXT4_BG_INODE_UNINIT    0x0001 /* Inode table/bitmap not in use */
 333 #define EXT4_BG_BLOCK_UNINIT    0x0002 /* Block bitmap not in use */
 334 #define EXT4_BG_INODE_ZEROED    0x0004 /* On-disk itable initialized to zero */
 335
 336 /*
 337  * Macro-instructions used to manage group descriptors
 338  */
 339 #define EXT4_MIN_DESC_SIZE              32
 340 #define EXT4_MIN_DESC_SIZE_64BIT        64
 341 #define EXT4_MAX_DESC_SIZE              EXT4_MIN_BLOCK_SIZE
 342 #define EXT4_DESC_SIZE(s)               (EXT4_SB(s)->s_desc_size)
 343 #ifdef __KERNEL__
 344 # define EXT4_BLOCKS_PER_GROUP(s)       (EXT4_SB(s)->s_blocks_per_group)
 345 # define EXT4_CLUSTERS_PER_GROUP(s)     (EXT4_SB(s)->s_clusters_per_group)
 346 # define EXT4_DESC_PER_BLOCK(s)         (EXT4_SB(s)->s_desc_per_block)
 347 # define EXT4_INODES_PER_GROUP(s)       (EXT4_SB(s)->s_inodes_per_group)
 348 # define EXT4_DESC_PER_BLOCK_BITS(s)    (EXT4_SB(s)->s_desc_per_block_bits)
 349 #else
 350 # define EXT4_BLOCKS_PER_GROUP(s)       ((s)->s_blocks_per_group)
 351 # define EXT4_DESC_PER_BLOCK(s)         (EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
 352 # define EXT4_INODES_PER_GROUP(s)       ((s)->s_inodes_per_group)
 353 #endif
 354
 355 /*
 356  * Constants relative to the data blocks
 357  */
 358 #define EXT4_NDIR_BLOCKS                12
 359 #define EXT4_IND_BLOCK                  EXT4_NDIR_BLOCKS
 360 #define EXT4_DIND_BLOCK                 (EXT4_IND_BLOCK + 1)
 361 #define EXT4_TIND_BLOCK                 (EXT4_DIND_BLOCK + 1)
 362 #define EXT4_N_BLOCKS                   (EXT4_TIND_BLOCK + 1)
 363
 364 /*
 365  * Inode flags
 366  */
 367 #define EXT4_SECRM_FL                   0x00000001 /* Secure deletion */
 368 #define EXT4_UNRM_FL                    0x00000002 /* Undelete */
 369 #define EXT4_COMPR_FL                   0x00000004 /* Compress file */
 370 #define EXT4_SYNC_FL                    0x00000008 /* Synchronous updates */
 371 #define EXT4_IMMUTABLE_FL               0x00000010 /* Immutable file */
 372 #define EXT4_APPEND_FL                  0x00000020 /* writes to file may only append */
 373 #define EXT4_NODUMP_FL                  0x00000040 /* do not dump file */
 374 #define EXT4_NOATIME_FL                 0x00000080 /* do not update atime */
 375 /* Reserved for compression usage... */
 376 #define EXT4_DIRTY_FL                   0x00000100
 377 #define EXT4_COMPRBLK_FL                0x00000200 /* One or more compressed clusters */
 378 #define EXT4_NOCOMPR_FL                 0x00000400 /* Don't compress */
 379 #define EXT4_ECOMPR_FL                  0x00000800 /* Compression error */
 380 /* End compression flags --- maybe not all used */
 381 #define EXT4_INDEX_FL                   0x00001000 /* hash-indexed directory */
 382 #define EXT4_IMAGIC_FL                  0x00002000 /* AFS directory */
 383 #define EXT4_JOURNAL_DATA_FL            0x00004000 /* file data should be journaled */
 384 #define EXT4_NOTAIL_FL                  0x00008000 /* file tail should not be merged */
 385 #define EXT4_DIRSYNC_FL                 0x00010000 /* dirsync behaviour (directories only) */
 386 #define EXT4_TOPDIR_FL                  0x00020000 /* Top of directory hierarchies*/
 387 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
 388 #define EXT4_EXTENTS_FL                 0x00080000 /* Inode uses extents */
 389 #define EXT4_EA_INODE_FL                0x00200000 /* Inode used for large EA */
 390 #define EXT4_EOFBLOCKS_FL               0x00400000 /* Blocks allocated beyond EOF */
 391 #define EXT4_INLINE_DATA_FL             0x10000000 /* Inode has inline data. */
 392 #define EXT4_RESERVED_FL                0x80000000 /* reserved for ext4 lib */
 393
 394 #define EXT4_FL_USER_VISIBLE            0x004BDFFF /* User visible flags */
 395 #define EXT4_FL_USER_MODIFIABLE         0x004380FF /* User modifiable flags */
 396
 397 /* Flags that should be inherited by new inodes from their parent. */
 398 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
 399                            EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
 400                            EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
 401                            EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
 402
 403 /* Flags that are appropriate for regular files (all but dir-specific ones). */
 404 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
 405
 406 /* Flags that are appropriate for non-directories/regular files. */
 407 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
 408
 409 /* Mask out flags that are inappropriate for the given type of inode. */
 410 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
 411 {
 412         if (S_ISDIR(mode))
 413                 return flags;
 414         else if (S_ISREG(mode))
 415                 return flags & EXT4_REG_FLMASK;
 416         else
 417                 return flags & EXT4_OTHER_FLMASK;
 418 }
 419
 420 /*
 421  * Inode flags used for atomic set/get
 422  */
 423 enum {
 424         EXT4_INODE_SECRM        = 0,    /* Secure deletion */
 425         EXT4_INODE_UNRM         = 1,    /* Undelete */
 426         EXT4_INODE_COMPR        = 2,    /* Compress file */
 427         EXT4_INODE_SYNC         = 3,    /* Synchronous updates */
 428         EXT4_INODE_IMMUTABLE    = 4,    /* Immutable file */
 429         EXT4_INODE_APPEND       = 5,    /* writes to file may only append */
 430         EXT4_INODE_NODUMP       = 6,    /* do not dump file */
 431         EXT4_INODE_NOATIME      = 7,    /* do not update atime */
 432 /* Reserved for compression usage... */
 433         EXT4_INODE_DIRTY        = 8,
 434         EXT4_INODE_COMPRBLK     = 9,    /* One or more compressed clusters */
 435         EXT4_INODE_NOCOMPR      = 10,   /* Don't compress */
 436         EXT4_INODE_ECOMPR       = 11,   /* Compression error */
 437 /* End compression flags --- maybe not all used */
 438         EXT4_INODE_INDEX        = 12,   /* hash-indexed directory */
 439         EXT4_INODE_IMAGIC       = 13,   /* AFS directory */
 440         EXT4_INODE_JOURNAL_DATA = 14,   /* file data should be journaled */
 441         EXT4_INODE_NOTAIL       = 15,   /* file tail should not be merged */
 442         EXT4_INODE_DIRSYNC      = 16,   /* dirsync behaviour (directories only) */
 443         EXT4_INODE_TOPDIR       = 17,   /* Top of directory hierarchies*/
 444         EXT4_INODE_HUGE_FILE    = 18,   /* Set to each huge file */
 445         EXT4_INODE_EXTENTS      = 19,   /* Inode uses extents */
 446         EXT4_INODE_EA_INODE     = 21,   /* Inode used for large EA */
 447         EXT4_INODE_EOFBLOCKS    = 22,   /* Blocks allocated beyond EOF */
 448         EXT4_INODE_INLINE_DATA  = 28,   /* Data in inode. */
 449         EXT4_INODE_RESERVED     = 31,   /* reserved for ext4 lib */
 450 };
 451
 452 /*
 453  * Since it's pretty easy to mix up bit numbers and hex values, we use a
 454  * build-time check to make sure that EXT4_XXX_FL is consistent with respect to
 455  * EXT4_INODE_XXX. If all is well, the macros will be dropped, so, it won't cost
 456  * any extra space in the compiled kernel image, otherwise, the build will fail.
 457  * It's important that these values are the same, since we are using
 458  * EXT4_INODE_XXX to test for flag values, but EXT4_XXX_FL must be consistent
 459  * with the values of FS_XXX_FL defined in include/linux/fs.h and the on-disk
 460  * values found in ext2, ext3 and ext4 filesystems, and of course the values
 461  * defined in e2fsprogs.
 462  *
 463  * It's not paranoia if the Murphy's Law really *is* out to get you.  :-)
 464  */
 465 #define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1 << EXT4_INODE_##FLAG))
 466 #define CHECK_FLAG_VALUE(FLAG) BUILD_BUG_ON(!TEST_FLAG_VALUE(FLAG))
 467
 468 static inline void ext4_check_flag_values(void)
 469 {
 470         CHECK_FLAG_VALUE(SECRM);
 471         CHECK_FLAG_VALUE(UNRM);
 472         CHECK_FLAG_VALUE(COMPR);
 473         CHECK_FLAG_VALUE(SYNC);
 474         CHECK_FLAG_VALUE(IMMUTABLE);
 475         CHECK_FLAG_VALUE(APPEND);
 476         CHECK_FLAG_VALUE(NODUMP);
 477         CHECK_FLAG_VALUE(NOATIME);
 478         CHECK_FLAG_VALUE(DIRTY);
 479         CHECK_FLAG_VALUE(COMPRBLK);
 480         CHECK_FLAG_VALUE(NOCOMPR);
 481         CHECK_FLAG_VALUE(ECOMPR);
 482         CHECK_FLAG_VALUE(INDEX);
 483         CHECK_FLAG_VALUE(IMAGIC);
 484         CHECK_FLAG_VALUE(JOURNAL_DATA);
 485         CHECK_FLAG_VALUE(NOTAIL);
 486         CHECK_FLAG_VALUE(DIRSYNC);
 487         CHECK_FLAG_VALUE(TOPDIR);
 488         CHECK_FLAG_VALUE(HUGE_FILE);
 489         CHECK_FLAG_VALUE(EXTENTS);
 490         CHECK_FLAG_VALUE(EA_INODE);
 491         CHECK_FLAG_VALUE(EOFBLOCKS);
 492         CHECK_FLAG_VALUE(INLINE_DATA);
 493         CHECK_FLAG_VALUE(RESERVED);
 494 }
 495
 496 /* Used to pass group descriptor data when online resize is done */
 497 struct ext4_new_group_input {
 498         __u32 group;            /* Group number for this data */
 499         __u64 block_bitmap;     /* Absolute block number of block bitmap */
 500         __u64 inode_bitmap;     /* Absolute block number of inode bitmap */
 501         __u64 inode_table;      /* Absolute block number of inode table start */
 502         __u32 blocks_count;     /* Total number of blocks in this group */
 503         __u16 reserved_blocks;  /* Number of reserved blocks in this group */
 504         __u16 unused;
 505 };
 506
 507 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
 508 struct compat_ext4_new_group_input {
 509         u32 group;
 510         compat_u64 block_bitmap;
 511         compat_u64 inode_bitmap;
 512         compat_u64 inode_table;
 513         u32 blocks_count;
 514         u16 reserved_blocks;
 515         u16 unused;
 516 };
 517 #endif
 518
 519 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
 520 struct ext4_new_group_data {
 521         __u32 group;
 522         __u64 block_bitmap;
 523         __u64 inode_bitmap;
 524         __u64 inode_table;
 525         __u32 blocks_count;
 526         __u16 reserved_blocks;
 527         __u16 unused;
 528         __u32 free_blocks_count;
 529 };
 530
 531 /* Indexes used to index group tables in ext4_new_group_data */
 532 enum {
 533         BLOCK_BITMAP = 0,       /* block bitmap */
 534         INODE_BITMAP,           /* inode bitmap */
 535         INODE_TABLE,            /* inode tables */
 536         GROUP_TABLE_COUNT,
 537 };
 538
 539 /*
 540  * Flags used by ext4_map_blocks()
 541  */
 542         /* Allocate any needed blocks and/or convert an unitialized
 543            extent to be an initialized ext4 */
 544 #define EXT4_GET_BLOCKS_CREATE                  0x0001
 545         /* Request the creation of an unitialized extent */
 546 #define EXT4_GET_BLOCKS_UNINIT_EXT              0x0002
 547 #define EXT4_GET_BLOCKS_CREATE_UNINIT_EXT       (EXT4_GET_BLOCKS_UNINIT_EXT|\
 548                                                  EXT4_GET_BLOCKS_CREATE)
 549         /* Caller is from the delayed allocation writeout path
 550          * finally doing the actual allocation of delayed blocks */
 551 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE        0x0004
 552         /* caller is from the direct IO path, request to creation of an
 553         unitialized extents if not allocated, split the uninitialized
 554         extent if blocks has been preallocated already*/
 555 #define EXT4_GET_BLOCKS_PRE_IO                  0x0008
 556 #define EXT4_GET_BLOCKS_CONVERT                 0x0010
 557 #define EXT4_GET_BLOCKS_IO_CREATE_EXT           (EXT4_GET_BLOCKS_PRE_IO|\
 558                                          EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
 559         /* Convert extent to initialized after IO complete */
 560 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT          (EXT4_GET_BLOCKS_CONVERT|\
 561                                          EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
 562         /* Eventual metadata allocation (due to growing extent tree)
 563          * should not fail, so try to use reserved blocks for that.*/
 564 #define EXT4_GET_BLOCKS_METADATA_NOFAIL         0x0020
 565         /* Don't normalize allocation size (used for fallocate) */
 566 #define EXT4_GET_BLOCKS_NO_NORMALIZE            0x0040
 567         /* Request will not result in inode size update (user for fallocate) */
 568 #define EXT4_GET_BLOCKS_KEEP_SIZE               0x0080
 569         /* Do not take i_data_sem locking in ext4_map_blocks */
 570 #define EXT4_GET_BLOCKS_NO_LOCK                 0x0100
 571         /* Do not put hole in extent cache */
 572 #define EXT4_GET_BLOCKS_NO_PUT_HOLE             0x0200
 573
 574 /*
 575  * Flags used by ext4_free_blocks
 576  */
 577 #define EXT4_FREE_BLOCKS_METADATA       0x0001
 578 #define EXT4_FREE_BLOCKS_FORGET         0x0002
 579 #define EXT4_FREE_BLOCKS_VALIDATED      0x0004
 580 #define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE 0x0008
 581 #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER   0x0010
 582 #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER    0x0020
 583
 584 /*
 585  * ioctl commands
 586  */
 587 #define EXT4_IOC_GETFLAGS               FS_IOC_GETFLAGS
 588 #define EXT4_IOC_SETFLAGS               FS_IOC_SETFLAGS
 589 #define EXT4_IOC_GETVERSION             _IOR('f', 3, long)
 590 #define EXT4_IOC_SETVERSION             _IOW('f', 4, long)
 591 #define EXT4_IOC_GETVERSION_OLD         FS_IOC_GETVERSION
 592 #define EXT4_IOC_SETVERSION_OLD         FS_IOC_SETVERSION
 593 #define EXT4_IOC_GETRSVSZ               _IOR('f', 5, long)
 594 #define EXT4_IOC_SETRSVSZ               _IOW('f', 6, long)
 595 #define EXT4_IOC_GROUP_EXTEND           _IOW('f', 7, unsigned long)
 596 #define EXT4_IOC_GROUP_ADD              _IOW('f', 8, struct ext4_new_group_input)
 597 #define EXT4_IOC_MIGRATE                _IO('f', 9)
 598  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
 599  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
 600 #define EXT4_IOC_ALLOC_DA_BLKS          _IO('f', 12)
 601 #define EXT4_IOC_MOVE_EXT               _IOWR('f', 15, struct move_extent)
 602 #define EXT4_IOC_RESIZE_FS              _IOW('f', 16, __u64)
 603 #define EXT4_IOC_SWAP_BOOT              _IO('f', 17)
 604
 605 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
 606 /*
 607  * ioctl commands in 32 bit emulation
 608  */
 609 #define EXT4_IOC32_GETFLAGS             FS_IOC32_GETFLAGS
 610 #define EXT4_IOC32_SETFLAGS             FS_IOC32_SETFLAGS
 611 #define EXT4_IOC32_GETVERSION           _IOR('f', 3, int)
 612 #define EXT4_IOC32_SETVERSION           _IOW('f', 4, int)
 613 #define EXT4_IOC32_GETRSVSZ             _IOR('f', 5, int)
 614 #define EXT4_IOC32_SETRSVSZ             _IOW('f', 6, int)
 615 #define EXT4_IOC32_GROUP_EXTEND         _IOW('f', 7, unsigned int)
 616 #define EXT4_IOC32_GROUP_ADD            _IOW('f', 8, struct compat_ext4_new_group_input)
 617 #define EXT4_IOC32_GETVERSION_OLD       FS_IOC32_GETVERSION
 618 #define EXT4_IOC32_SETVERSION_OLD       FS_IOC32_SETVERSION
 619 #endif
 620
 621 /* Max physical block we can address w/o extents */
 622 #define EXT4_MAX_BLOCK_FILE_PHYS        0xFFFFFFFF
 623
 624 /*
 625  * Structure of an inode on the disk
 626  */
 627 struct ext4_inode {
 628         __le16  i_mode;         /* File mode */
 629         __le16  i_uid;          /* Low 16 bits of Owner Uid */
 630         __le32  i_size_lo;      /* Size in bytes */
 631         __le32  i_atime;        /* Access time */
 632         __le32  i_ctime;        /* Inode Change time */
 633         __le32  i_mtime;        /* Modification time */
 634         __le32  i_dtime;        /* Deletion Time */
 635         __le16  i_gid;          /* Low 16 bits of Group Id */
 636         __le16  i_links_count;  /* Links count */
 637         __le32  i_blocks_lo;    /* Blocks count */
 638         __le32  i_flags;        /* File flags */
 639         union {
 640                 struct {
 641                         __le32  l_i_version;
 642                 } linux1;
 643                 struct {
 644                         __u32  h_i_translator;
 645                 } hurd1;
 646                 struct {
 647                         __u32  m_i_reserved1;
 648                 } masix1;
 649         } osd1;                         /* OS dependent 1 */
 650         __le32  i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
 651         __le32  i_generation;   /* File version (for NFS) */
 652         __le32  i_file_acl_lo;  /* File ACL */
 653         __le32  i_size_high;
 654         __le32  i_obso_faddr;   /* Obsoleted fragment address */
 655         union {
 656                 struct {
 657                         __le16  l_i_blocks_high; /* were l_i_reserved1 */
 658                         __le16  l_i_file_acl_high;
 659                         __le16  l_i_uid_high;   /* these 2 fields */
 660                         __le16  l_i_gid_high;   /* were reserved2[0] */
 661                         __le16  l_i_checksum_lo;/* crc32c(uuid+inum+inode) LE */
 662                         __le16  l_i_reserved;
 663                 } linux2;
 664                 struct {
 665                         __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
 666                         __u16   h_i_mode_high;
 667                         __u16   h_i_uid_high;
 668                         __u16   h_i_gid_high;
 669                         __u32   h_i_author;
 670                 } hurd2;
 671                 struct {
 672                         __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
 673                         __le16  m_i_file_acl_high;
 674                         __u32   m_i_reserved2[2];
 675                 } masix2;
 676         } osd2;                         /* OS dependent 2 */
 677         __le16  i_extra_isize;
 678         __le16  i_checksum_hi;  /* crc32c(uuid+inum+inode) BE */
 679         __le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
 680         __le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
 681         __le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
 682         __le32  i_crtime;       /* File Creation time */
 683         __le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
 684         __le32  i_version_hi;   /* high 32 bits for 64-bit version */
 685 };
 686
 687 struct move_extent {
 688         __u32 reserved;         /* should be zero */
 689         __u32 donor_fd;         /* donor file descriptor */
 690         __u64 orig_start;       /* logical start offset in block for orig */
 691         __u64 donor_start;      /* logical start offset in block for donor */
 692         __u64 len;              /* block length to be moved */
 693         __u64 moved_len;        /* moved block length */
 694 };
 695
 696 #define EXT4_EPOCH_BITS 2
 697 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
 698 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
 699
 700 /*
 701  * Extended fields will fit into an inode if the filesystem was formatted
 702  * with large inodes (-I 256 or larger) and there are not currently any EAs
 703  * consuming all of the available space. For new inodes we always reserve
 704  * enough space for the kernel's known extended fields, but for inodes
 705  * created with an old kernel this might not have been the case. None of
 706  * the extended inode fields is critical for correct filesystem operation.
 707  * This macro checks if a certain field fits in the inode. Note that
 708  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
 709  */
 710 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)   \
 711         ((offsetof(typeof(*ext4_inode), field) +        \
 712           sizeof((ext4_inode)->field))                  \
 713         <= (EXT4_GOOD_OLD_INODE_SIZE +                  \
 714             (einode)->i_extra_isize))                   \
 715
 716 static inline __le32 ext4_encode_extra_time(struct timespec *time)
 717 {
 718        return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
 719                            (time->tv_sec >> 32) & EXT4_EPOCH_MASK : 0) |
 720                           ((time->tv_nsec << EXT4_EPOCH_BITS) & EXT4_NSEC_MASK));
 721 }
 722
 723 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
 724 {
 725        if (sizeof(time->tv_sec) > 4)
 726                time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
 727                                << 32;
 728        time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
 729 }
 730
 731 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)                          \
 732 do {                                                                           \
 733         (raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);               \
 734         if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
 735                 (raw_inode)->xtime ## _extra =                                 \
 736                                 ext4_encode_extra_time(&(inode)->xtime);       \
 737 } while (0)
 738
 739 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)                        \
 740 do {                                                                           \
 741         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))                      \
 742                 (raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
 743         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))            \
 744                 (raw_inode)->xtime ## _extra =                                 \
 745                                 ext4_encode_extra_time(&(einode)->xtime);      \
 746 } while (0)
 747
 748 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)                          \
 749 do {                                                                           \
 750         (inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
 751         if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
 752                 ext4_decode_extra_time(&(inode)->xtime,                        \
 753                                        raw_inode->xtime ## _extra);            \
 754         else                                                                   \
 755                 (inode)->xtime.tv_nsec = 0;                                    \
 756 } while (0)
 757
 758 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)                        \
 759 do {                                                                           \
 760         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))                      \
 761                 (einode)->xtime.tv_sec =                                       \
 762                         (signed)le32_to_cpu((raw_inode)->xtime);               \
 763         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))            \
 764                 ext4_decode_extra_time(&(einode)->xtime,                       \
 765                                        raw_inode->xtime ## _extra);            \
 766         else                                                                   \
 767                 (einode)->xtime.tv_nsec = 0;                                   \
 768 } while (0)
 769
 770 #define i_disk_version osd1.linux1.l_i_version
 771
 772 #if defined(__KERNEL__) || defined(__linux__)
 773 #define i_reserved1     osd1.linux1.l_i_reserved1
 774 #define i_file_acl_high osd2.linux2.l_i_file_acl_high
 775 #define i_blocks_high   osd2.linux2.l_i_blocks_high
 776 #define i_uid_low       i_uid
 777 #define i_gid_low       i_gid
 778 #define i_uid_high      osd2.linux2.l_i_uid_high
 779 #define i_gid_high      osd2.linux2.l_i_gid_high
 780 #define i_checksum_lo   osd2.linux2.l_i_checksum_lo
 781
 782 #elif defined(__GNU__)
 783
 784 #define i_translator    osd1.hurd1.h_i_translator
 785 #define i_uid_high      osd2.hurd2.h_i_uid_high
 786 #define i_gid_high      osd2.hurd2.h_i_gid_high
 787 #define i_author        osd2.hurd2.h_i_author
 788
 789 #elif defined(__masix__)
 790
 791 #define i_reserved1     osd1.masix1.m_i_reserved1
 792 #define i_file_acl_high osd2.masix2.m_i_file_acl_high
 793 #define i_reserved2     osd2.masix2.m_i_reserved2
 794
 795 #endif /* defined(__KERNEL__) || defined(__linux__) */
 796
 797 #include "extents_status.h"
 798
 799 /*
 800  * fourth extended file system inode data in memory
 801  */
 802 struct ext4_inode_info {
 803         __le32  i_data[15];     /* unconverted */
 804         __u32   i_dtime;
 805         ext4_fsblk_t    i_file_acl;
 806
 807         /*
 808          * i_block_group is the number of the block group which contains
 809          * this file's inode.  Constant across the lifetime of the inode,
 810          * it is ued for making block allocation decisions - we try to
 811          * place a file's data blocks near its inode block, and new inodes
 812          * near to their parent directory's inode.
 813          */
 814         ext4_group_t    i_block_group;
 815         ext4_lblk_t     i_dir_start_lookup;
 816 #if (BITS_PER_LONG < 64)
 817         unsigned long   i_state_flags;          /* Dynamic state flags */
 818 #endif
 819         unsigned long   i_flags;
 820
 821         /*
 822          * Extended attributes can be read independently of the main file
 823          * data. Taking i_mutex even when reading would cause contention
 824          * between readers of EAs and writers of regular file data, so
 825          * instead we synchronize on xattr_sem when reading or changing
 826          * EAs.
 827          */
 828         struct rw_semaphore xattr_sem;
 829
 830         struct list_head i_orphan;      /* unlinked but open inodes */
 831
 832         /*
 833          * i_disksize keeps track of what the inode size is ON DISK, not
 834          * in memory.  During truncate, i_size is set to the new size by
 835          * the VFS prior to calling ext4_truncate(), but the filesystem won't
 836          * set i_disksize to 0 until the truncate is actually under way.
 837          *
 838          * The intent is that i_disksize always represents the blocks which
 839          * are used by this file.  This allows recovery to restart truncate
 840          * on orphans if we crash during truncate.  We actually write i_disksize
 841          * into the on-disk inode when writing inodes out, instead of i_size.
 842          *
 843          * The only time when i_disksize and i_size may be different is when
 844          * a truncate is in progress.  The only things which change i_disksize
 845          * are ext4_get_block (growth) and ext4_truncate (shrinkth).
 846          */
 847         loff_t  i_disksize;
 848
 849         /*
 850          * i_data_sem is for serialising ext4_truncate() against
 851          * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
 852          * data tree are chopped off during truncate. We can't do that in
 853          * ext4 because whenever we perform intermediate commits during
 854          * truncate, the inode and all the metadata blocks *must* be in a
 855          * consistent state which allows truncation of the orphans to restart
 856          * during recovery.  Hence we must fix the get_block-vs-truncate race
 857          * by other means, so we have i_data_sem.
 858          */
 859         struct rw_semaphore i_data_sem;
 860         struct inode vfs_inode;
 861         struct jbd2_inode *jinode;
 862
 863         /*
 864          * File creation time. Its function is same as that of
 865          * struct timespec i_{a,c,m}time in the generic inode.
 866          */
 867         struct timespec i_crtime;
 868
 869         /* mballoc */
 870         struct list_head i_prealloc_list;
 871         spinlock_t i_prealloc_lock;
 872
 873         /* extents status tree */
 874         struct ext4_es_tree i_es_tree;
 875         rwlock_t i_es_lock;
 876         struct list_head i_es_lru;
 877         unsigned int i_es_lru_nr;       /* protected by i_es_lock */
 878
 879         /* ialloc */
 880         ext4_group_t    i_last_alloc_group;
 881
 882         /* allocation reservation info for delalloc */
 883         /* In case of bigalloc, these refer to clusters rather than blocks */
 884         unsigned int i_reserved_data_blocks;
 885         unsigned int i_reserved_meta_blocks;
 886         unsigned int i_allocated_meta_blocks;
 887         ext4_lblk_t i_da_metadata_calc_last_lblock;
 888         int i_da_metadata_calc_len;
 889
 890         /* on-disk additional length */
 891         __u16 i_extra_isize;
 892
 893         /* Indicate the inline data space. */
 894         u16 i_inline_off;
 895         u16 i_inline_size;
 896
 897 #ifdef CONFIG_QUOTA
 898         /* quota space reservation, managed internally by quota code */
 899         qsize_t i_reserved_quota;
 900 #endif
 901
 902         /* completed IOs that might need unwritten extents handling */
 903         struct list_head i_completed_io_list;
 904         spinlock_t i_completed_io_lock;
 905         atomic_t i_ioend_count; /* Number of outstanding io_end structs */
 906         atomic_t i_unwritten; /* Nr. of inflight conversions pending */
 907         struct work_struct i_unwritten_work;    /* deferred extent conversion */
 908
 909         spinlock_t i_block_reservation_lock;
 910
 911         /*
 912          * Transactions that contain inode's metadata needed to complete
 913          * fsync and fdatasync, respectively.
 914          */
 915         tid_t i_sync_tid;
 916         tid_t i_datasync_tid;
 917
 918         /* Precomputed uuid+inum+igen checksum for seeding inode checksums */
 919         __u32 i_csum_seed;
 920 };
 921
 922 /*
 923  * File system states
 924  */
 925 #define EXT4_VALID_FS                   0x0001  /* Unmounted cleanly */
 926 #define EXT4_ERROR_FS                   0x0002  /* Errors detected */
 927 #define EXT4_ORPHAN_FS                  0x0004  /* Orphans being recovered */
 928
 929 /*
 930  * Misc. filesystem flags
 931  */
 932 #define EXT2_FLAGS_SIGNED_HASH          0x0001  /* Signed dirhash in use */
 933 #define EXT2_FLAGS_UNSIGNED_HASH        0x0002  /* Unsigned dirhash in use */
 934 #define EXT2_FLAGS_TEST_FILESYS         0x0004  /* to test development code */
 935
 936 /*
 937  * Mount flags set via mount options or defaults
 938  */
 939 #define EXT4_MOUNT_GRPID                0x00004 /* Create files with directory's group */
 940 #define EXT4_MOUNT_DEBUG                0x00008 /* Some debugging messages */
 941 #define EXT4_MOUNT_ERRORS_CONT          0x00010 /* Continue on errors */
 942 #define EXT4_MOUNT_ERRORS_RO            0x00020 /* Remount fs ro on errors */
 943 #define EXT4_MOUNT_ERRORS_PANIC         0x00040 /* Panic on errors */
 944 #define EXT4_MOUNT_ERRORS_MASK          0x00070
 945 #define EXT4_MOUNT_MINIX_DF             0x00080 /* Mimics the Minix statfs */
 946 #define EXT4_MOUNT_NOLOAD               0x00100 /* Don't use existing journal*/
 947 #define EXT4_MOUNT_DATA_FLAGS           0x00C00 /* Mode for data writes: */
 948 #define EXT4_MOUNT_JOURNAL_DATA         0x00400 /* Write data to journal */
 949 #define EXT4_MOUNT_ORDERED_DATA         0x00800 /* Flush data before commit */
 950 #define EXT4_MOUNT_WRITEBACK_DATA       0x00C00 /* No data ordering */
 951 #define EXT4_MOUNT_UPDATE_JOURNAL       0x01000 /* Update the journal format */
 952 #define EXT4_MOUNT_NO_UID32             0x02000  /* Disable 32-bit UIDs */
 953 #define EXT4_MOUNT_XATTR_USER           0x04000 /* Extended user attributes */
 954 #define EXT4_MOUNT_POSIX_ACL            0x08000 /* POSIX Access Control Lists */
 955 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC     0x10000 /* No auto delalloc mapping */
 956 #define EXT4_MOUNT_BARRIER              0x20000 /* Use block barriers */
 957 #define EXT4_MOUNT_QUOTA                0x80000 /* Some quota option set */
 958 #define EXT4_MOUNT_USRQUOTA             0x100000 /* "old" user quota */
 959 #define EXT4_MOUNT_GRPQUOTA             0x200000 /* "old" group quota */
 960 #define EXT4_MOUNT_DIOREAD_NOLOCK       0x400000 /* Enable support for dio read nolocking */
 961 #define EXT4_MOUNT_JOURNAL_CHECKSUM     0x800000 /* Journal checksums */
 962 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT 0x1000000 /* Journal Async Commit */
 963 #define EXT4_MOUNT_DELALLOC             0x8000000 /* Delalloc support */
 964 #define EXT4_MOUNT_DATA_ERR_ABORT       0x10000000 /* Abort on file data write */
 965 #define EXT4_MOUNT_BLOCK_VALIDITY       0x20000000 /* Block validity checking */
 966 #define EXT4_MOUNT_DISCARD              0x40000000 /* Issue DISCARD requests */
 967 #define EXT4_MOUNT_INIT_INODE_TABLE     0x80000000 /* Initialize uninitialized itables */
 968
 969 /*
 970  * Mount flags set either automatically (could not be set by mount option)
 971  * based on per file system feature or property or in special cases such as
 972  * distinguishing between explicit mount option definition and default.
 973  */
 974 #define EXT4_MOUNT2_EXPLICIT_DELALLOC   0x00000001 /* User explicitly
 975                                                       specified delalloc */
 976 #define EXT4_MOUNT2_STD_GROUP_SIZE      0x00000002 /* We have standard group
 977                                                       size of blocksize * 8
 978                                                       blocks */
 979
 980 #define clear_opt(sb, opt)              EXT4_SB(sb)->s_mount_opt &= \
 981                                                 ~EXT4_MOUNT_##opt
 982 #define set_opt(sb, opt)                EXT4_SB(sb)->s_mount_opt |= \
 983                                                 EXT4_MOUNT_##opt
 984 #define test_opt(sb, opt)               (EXT4_SB(sb)->s_mount_opt & \
 985                                          EXT4_MOUNT_##opt)
 986
 987 #define clear_opt2(sb, opt)             EXT4_SB(sb)->s_mount_opt2 &= \
 988                                                 ~EXT4_MOUNT2_##opt
 989 #define set_opt2(sb, opt)               EXT4_SB(sb)->s_mount_opt2 |= \
 990                                                 EXT4_MOUNT2_##opt
 991 #define test_opt2(sb, opt)              (EXT4_SB(sb)->s_mount_opt2 & \
 992                                          EXT4_MOUNT2_##opt)
 993
 994 #define ext4_test_and_set_bit           __test_and_set_bit_le
 995 #define ext4_set_bit                    __set_bit_le
 996 #define ext4_set_bit_atomic             ext2_set_bit_atomic
 997 #define ext4_test_and_clear_bit         __test_and_clear_bit_le
 998 #define ext4_clear_bit                  __clear_bit_le
 999 #define ext4_clear_bit_atomic           ext2_clear_bit_atomic
1000 #define ext4_test_bit                   test_bit_le
1001 #define ext4_find_next_zero_bit         find_next_zero_bit_le
1002 #define ext4_find_next_bit              find_next_bit_le
1003
1004 extern void ext4_set_bits(void *bm, int cur, int len);
1005
1006 /*
1007  * Maximal mount counts between two filesystem checks
1008  */
1009 #define EXT4_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
1010 #define EXT4_DFL_CHECKINTERVAL          0       /* Don't use interval check */
1011
1012 /*
1013  * Behaviour when detecting errors
1014  */
1015 #define EXT4_ERRORS_CONTINUE            1       /* Continue execution */
1016 #define EXT4_ERRORS_RO                  2       /* Remount fs read-only */
1017 #define EXT4_ERRORS_PANIC               3       /* Panic */
1018 #define EXT4_ERRORS_DEFAULT             EXT4_ERRORS_CONTINUE
1019
1020 /* Metadata checksum algorithm codes */
1021 #define EXT4_CRC32C_CHKSUM              1
1022
1023 /*
1024  * Structure of the super block
1025  */
1026 struct ext4_super_block {
1027 /*00*/  __le32  s_inodes_count;         /* Inodes count */
1028         __le32  s_blocks_count_lo;      /* Blocks count */
1029         __le32  s_r_blocks_count_lo;    /* Reserved blocks count */
1030         __le32  s_free_blocks_count_lo; /* Free blocks count */
1031 /*10*/  __le32  s_free_inodes_count;    /* Free inodes count */
1032         __le32  s_first_data_block;     /* First Data Block */
1033         __le32  s_log_block_size;       /* Block size */
1034         __le32  s_log_cluster_size;     /* Allocation cluster size */
1035 /*20*/  __le32  s_blocks_per_group;     /* # Blocks per group */
1036         __le32  s_clusters_per_group;   /* # Clusters per group */
1037         __le32  s_inodes_per_group;     /* # Inodes per group */
1038         __le32  s_mtime;                /* Mount time */
1039 /*30*/  __le32  s_wtime;                /* Write time */
1040         __le16  s_mnt_count;            /* Mount count */
1041         __le16  s_max_mnt_count;        /* Maximal mount count */
1042         __le16  s_magic;                /* Magic signature */
1043         __le16  s_state;                /* File system state */
1044         __le16  s_errors;               /* Behaviour when detecting errors */
1045         __le16  s_minor_rev_level;      /* minor revision level */
1046 /*40*/  __le32  s_lastcheck;            /* time of last check */
1047         __le32  s_checkinterval;        /* max. time between checks */
1048         __le32  s_creator_os;           /* OS */
1049         __le32  s_rev_level;            /* Revision level */
1050 /*50*/  __le16  s_def_resuid;           /* Default uid for reserved blocks */
1051         __le16  s_def_resgid;           /* Default gid for reserved blocks */
1052         /*
1053          * These fields are for EXT4_DYNAMIC_REV superblocks only.
1054          *
1055          * Note: the difference between the compatible feature set and
1056          * the incompatible feature set is that if there is a bit set
1057          * in the incompatible feature set that the kernel doesn't
1058          * know about, it should refuse to mount the filesystem.
1059          *
1060          * e2fsck's requirements are more strict; if it doesn't know
1061          * about a feature in either the compatible or incompatible
1062          * feature set, it must abort and not try to meddle with
1063          * things it doesn't understand...
1064          */
1065         __le32  s_first_ino;            /* First non-reserved inode */
1066         __le16  s_inode_size;           /* size of inode structure */
1067         __le16  s_block_group_nr;       /* block group # of this superblock */
1068         __le32  s_feature_compat;       /* compatible feature set */
1069 /*60*/  __le32  s_feature_incompat;     /* incompatible feature set */
1070         __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
1071 /*68*/  __u8    s_uuid[16];             /* 128-bit uuid for volume */
1072 /*78*/  char    s_volume_name[16];      /* volume name */
1073 /*88*/  char    s_last_mounted[64];     /* directory where last mounted */
1074 /*C8*/  __le32  s_algorithm_usage_bitmap; /* For compression */
1075         /*
1076          * Performance hints.  Directory preallocation should only
1077          * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
1078          */
1079         __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
1080         __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
1081         __le16  s_reserved_gdt_blocks;  /* Per group desc for online growth */
1082         /*
1083          * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
1084          */
1085 /*D0*/  __u8    s_journal_uuid[16];     /* uuid of journal superblock */
1086 /*E0*/  __le32  s_journal_inum;         /* inode number of journal file */
1087         __le32  s_journal_dev;          /* device number of journal file */
1088         __le32  s_last_orphan;          /* start of list of inodes to delete */
1089         __le32  s_hash_seed[4];         /* HTREE hash seed */
1090         __u8    s_def_hash_version;     /* Default hash version to use */
1091         __u8    s_jnl_backup_type;
1092         __le16  s_desc_size;            /* size of group descriptor */
1093 /*100*/ __le32  s_default_mount_opts;
1094         __le32  s_first_meta_bg;        /* First metablock block group */
1095         __le32  s_mkfs_time;            /* When the filesystem was created */
1096         __le32  s_jnl_blocks[17];       /* Backup of the journal inode */
1097         /* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
1098 /*150*/ __le32  s_blocks_count_hi;      /* Blocks count */
1099         __le32  s_r_blocks_count_hi;    /* Reserved blocks count */
1100         __le32  s_free_blocks_count_hi; /* Free blocks count */
1101         __le16  s_min_extra_isize;      /* All inodes have at least # bytes */
1102         __le16  s_want_extra_isize;     /* New inodes should reserve # bytes */
1103         __le32  s_flags;                /* Miscellaneous flags */
1104         __le16  s_raid_stride;          /* RAID stride */
1105         __le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */
1106         __le64  s_mmp_block;            /* Block for multi-mount protection */
1107         __le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1108         __u8    s_log_groups_per_flex;  /* FLEX_BG group size */
1109         __u8    s_checksum_type;        /* metadata checksum algorithm used */
1110         __le16  s_reserved_pad;
1111         __le64  s_kbytes_written;       /* nr of lifetime kilobytes written */
1112         __le32  s_snapshot_inum;        /* Inode number of active snapshot */
1113         __le32  s_snapshot_id;          /* sequential ID of active snapshot */
1114         __le64  s_snapshot_r_blocks_count; /* reserved blocks for active
1115                                               snapshot's future use */
1116         __le32  s_snapshot_list;        /* inode number of the head of the
1117                                            on-disk snapshot list */
1118 #define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
1119         __le32  s_error_count;          /* number of fs errors */
1120         __le32  s_first_error_time;     /* first time an error happened */
1121         __le32  s_first_error_ino;      /* inode involved in first error */
1122         __le64  s_first_error_block;    /* block involved of first error */
1123         __u8    s_first_error_func[32]; /* function where the error happened */
1124         __le32  s_first_error_line;     /* line number where error happened */
1125         __le32  s_last_error_time;      /* most recent time of an error */
1126         __le32  s_last_error_ino;       /* inode involved in last error */
1127         __le32  s_last_error_line;      /* line number where error happened */
1128         __le64  s_last_error_block;     /* block involved of last error */
1129         __u8    s_last_error_func[32];  /* function where the error happened */
1130 #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
1131         __u8    s_mount_opts[64];
1132         __le32  s_usr_quota_inum;       /* inode for tracking user quota */
1133         __le32  s_grp_quota_inum;       /* inode for tracking group quota */
1134         __le32  s_overhead_clusters;    /* overhead blocks/clusters in fs */
1135         __le32  s_reserved[108];        /* Padding to the end of the block */
1136         __le32  s_checksum;             /* crc32c(superblock) */
1137 };
1138
1139 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1140
1141 #ifdef __KERNEL__
1142
1143 /*
1144  * run-time mount flags
1145  */
1146 #define EXT4_MF_MNTDIR_SAMPLED  0x0001
1147 #define EXT4_MF_FS_ABORTED      0x0002  /* Fatal error detected */
1148
1149 /*
1150  * fourth extended-fs super-block data in memory
1151  */
1152 struct ext4_sb_info {
1153         unsigned long s_desc_size;      /* Size of a group descriptor in bytes */
1154         unsigned long s_inodes_per_block;/* Number of inodes per block */
1155         unsigned long s_blocks_per_group;/* Number of blocks in a group */
1156         unsigned long s_clusters_per_group; /* Number of clusters in a group */
1157         unsigned long s_inodes_per_group;/* Number of inodes in a group */
1158         unsigned long s_itb_per_group;  /* Number of inode table blocks per group */
1159         unsigned long s_gdb_count;      /* Number of group descriptor blocks */
1160         unsigned long s_desc_per_block; /* Number of group descriptors per block */
1161         ext4_group_t s_groups_count;    /* Number of groups in the fs */
1162         ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1163         unsigned long s_overhead;  /* # of fs overhead clusters */
1164         unsigned int s_cluster_ratio;   /* Number of blocks per cluster */
1165         unsigned int s_cluster_bits;    /* log2 of s_cluster_ratio */
1166         loff_t s_bitmap_maxbytes;       /* max bytes for bitmap files */
1167         struct buffer_head * s_sbh;     /* Buffer containing the super block */
1168         struct ext4_super_block *s_es;  /* Pointer to the super block in the buffer */
1169         struct buffer_head **s_group_desc;
1170         unsigned int s_mount_opt;
1171         unsigned int s_mount_opt2;
1172         unsigned int s_mount_flags;
1173         unsigned int s_def_mount_opt;
1174         ext4_fsblk_t s_sb_block;
1175         atomic64_t s_resv_clusters;
1176         kuid_t s_resuid;
1177         kgid_t s_resgid;
1178         unsigned short s_mount_state;
1179         unsigned short s_pad;
1180         int s_addr_per_block_bits;
1181         int s_desc_per_block_bits;
1182         int s_inode_size;
1183         int s_first_ino;
1184         unsigned int s_inode_readahead_blks;
1185         unsigned int s_inode_goal;
1186         spinlock_t s_next_gen_lock;
1187         u32 s_next_generation;
1188         u32 s_hash_seed[4];
1189         int s_def_hash_version;
1190         int s_hash_unsigned;    /* 3 if hash should be signed, 0 if not */
1191         struct percpu_counter s_freeclusters_counter;
1192         struct percpu_counter s_freeinodes_counter;
1193         struct percpu_counter s_dirs_counter;
1194         struct percpu_counter s_dirtyclusters_counter;
1195         struct blockgroup_lock *s_blockgroup_lock;
1196         struct proc_dir_entry *s_proc;
1197         struct kobject s_kobj;
1198         struct completion s_kobj_unregister;
1199         struct super_block *s_sb;
1200
1201         /* Journaling */
1202         struct journal_s *s_journal;
1203         struct list_head s_orphan;
1204         struct mutex s_orphan_lock;
1205         unsigned long s_resize_flags;           /* Flags indicating if there
1206                                                    is a resizer */
1207         unsigned long s_commit_interval;
1208         u32 s_max_batch_time;
1209         u32 s_min_batch_time;
1210         struct block_device *journal_bdev;
1211 #ifdef CONFIG_QUOTA
1212         char *s_qf_names[MAXQUOTAS];            /* Names of quota files with journalled quota */
1213         int s_jquota_fmt;                       /* Format of quota to use */
1214 #endif
1215         unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1216         struct rb_root system_blks;
1217
1218 #ifdef EXTENTS_STATS
1219         /* ext4 extents stats */
1220         unsigned long s_ext_min;
1221         unsigned long s_ext_max;
1222         unsigned long s_depth_max;
1223         spinlock_t s_ext_stats_lock;
1224         unsigned long s_ext_blocks;
1225         unsigned long s_ext_extents;
1226 #endif
1227
1228         /* for buddy allocator */
1229         struct ext4_group_info ***s_group_info;
1230         struct inode *s_buddy_cache;
1231         spinlock_t s_md_lock;
1232         unsigned short *s_mb_offsets;
1233         unsigned int *s_mb_maxs;
1234         unsigned int s_group_info_size;
1235
1236         /* tunables */
1237         unsigned long s_stripe;
1238         unsigned int s_mb_stream_request;
1239         unsigned int s_mb_max_to_scan;
1240         unsigned int s_mb_min_to_scan;
1241         unsigned int s_mb_stats;
1242         unsigned int s_mb_order2_reqs;
1243         unsigned int s_mb_group_prealloc;
1244         unsigned int s_max_dir_size_kb;
1245         /* where last allocation was done - for stream allocation */
1246         unsigned long s_mb_last_group;
1247         unsigned long s_mb_last_start;
1248
1249         /* stats for buddy allocator */
1250         atomic_t s_bal_reqs;    /* number of reqs with len > 1 */
1251         atomic_t s_bal_success; /* we found long enough chunks */
1252         atomic_t s_bal_allocated;       /* in blocks */
1253         atomic_t s_bal_ex_scanned;      /* total extents scanned */
1254         atomic_t s_bal_goals;   /* goal hits */
1255         atomic_t s_bal_breaks;  /* too long searches */
1256         atomic_t s_bal_2orders; /* 2^order hits */
1257         spinlock_t s_bal_lock;
1258         unsigned long s_mb_buddies_generated;
1259         unsigned long long s_mb_generation_time;
1260         atomic_t s_mb_lost_chunks;
1261         atomic_t s_mb_preallocated;
1262         atomic_t s_mb_discarded;
1263         atomic_t s_lock_busy;
1264
1265         /* locality groups */
1266         struct ext4_locality_group __percpu *s_locality_groups;
1267
1268         /* for write statistics */
1269         unsigned long s_sectors_written_start;
1270         u64 s_kbytes_written;
1271
1272         /* the size of zero-out chunk */
1273         unsigned int s_extent_max_zeroout_kb;
1274
1275         unsigned int s_log_groups_per_flex;
1276         struct flex_groups *s_flex_groups;
1277         ext4_group_t s_flex_groups_allocated;
1278
1279         /* workqueue for dio unwritten */
1280         struct workqueue_struct *dio_unwritten_wq;
1281
1282         /* timer for periodic error stats printing */
1283         struct timer_list s_err_report;
1284
1285         /* Lazy inode table initialization info */
1286         struct ext4_li_request *s_li_request;
1287         /* Wait multiplier for lazy initialization thread */
1288         unsigned int s_li_wait_mult;
1289
1290         /* Kernel thread for multiple mount protection */
1291         struct task_struct *s_mmp_tsk;
1292
1293         /* record the last minlen when FITRIM is called. */
1294         atomic_t s_last_trim_minblks;
1295
1296         /* Reference to checksum algorithm driver via cryptoapi */
1297         struct crypto_shash *s_chksum_driver;
1298
1299         /* Precomputed FS UUID checksum for seeding other checksums */
1300         __u32 s_csum_seed;
1301
1302         /* Reclaim extents from extent status tree */
1303         struct shrinker s_es_shrinker;
1304         struct list_head s_es_lru;
1305         struct percpu_counter s_extent_cache_cnt;
1306         spinlock_t s_es_lru_lock ____cacheline_aligned_in_smp;
1307 };
1308
1309 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1310 {
1311         return sb->s_fs_info;
1312 }
1313 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1314 {
1315         return container_of(inode, struct ext4_inode_info, vfs_inode);
1316 }
1317
1318 static inline struct timespec ext4_current_time(struct inode *inode)
1319 {
1320         return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1321                 current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1322 }
1323
1324 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1325 {
1326         return ino == EXT4_ROOT_INO ||
1327                 ino == EXT4_USR_QUOTA_INO ||
1328                 ino == EXT4_GRP_QUOTA_INO ||
1329                 ino == EXT4_BOOT_LOADER_INO ||
1330                 ino == EXT4_JOURNAL_INO ||
1331                 ino == EXT4_RESIZE_INO ||
1332                 (ino >= EXT4_FIRST_INO(sb) &&
1333                  ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1334 }
1335
1336 static inline void ext4_set_io_unwritten_flag(struct inode *inode,
1337                                               struct ext4_io_end *io_end)
1338 {
1339         if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
1340                 io_end->flag |= EXT4_IO_END_UNWRITTEN;
1341                 atomic_inc(&EXT4_I(inode)->i_unwritten);
1342         }
1343 }
1344
1345 static inline ext4_io_end_t *ext4_inode_aio(struct inode *inode)
1346 {
1347         return inode->i_private;
1348 }
1349
1350 static inline void ext4_inode_aio_set(struct inode *inode, ext4_io_end_t *io)
1351 {
1352         inode->i_private = io;
1353 }
1354
1355 /*
1356  * Inode dynamic state flags
1357  */
1358 enum {
1359         EXT4_STATE_JDATA,               /* journaled data exists */
1360         EXT4_STATE_NEW,                 /* inode is newly created */
1361         EXT4_STATE_XATTR,               /* has in-inode xattrs */
1362         EXT4_STATE_NO_EXPAND,           /* No space for expansion */
1363         EXT4_STATE_DA_ALLOC_CLOSE,      /* Alloc DA blks on close */
1364         EXT4_STATE_EXT_MIGRATE,         /* Inode is migrating */
1365         EXT4_STATE_DIO_UNWRITTEN,       /* need convert on dio done*/
1366         EXT4_STATE_NEWENTRY,            /* File just added to dir */
1367         EXT4_STATE_DELALLOC_RESERVED,   /* blks already reserved for delalloc */
1368         EXT4_STATE_DIOREAD_LOCK,        /* Disable support for dio read
1369                                            nolocking */
1370         EXT4_STATE_MAY_INLINE_DATA,     /* may have in-inode data */
1371         EXT4_STATE_ORDERED_MODE,        /* data=ordered mode */
1372 };
1373
1374 #define EXT4_INODE_BIT_FNS(name, field, offset)                         \
1375 static inline int ext4_test_inode_##name(struct inode *inode, int bit)  \
1376 {                                                                       \
1377         return test_bit(bit + (offset), &EXT4_I(inode)->i_##field);     \
1378 }                                                                       \
1379 static inline void ext4_set_inode_##name(struct inode *inode, int bit)  \
1380 {                                                                       \
1381         set_bit(bit + (offset), &EXT4_I(inode)->i_##field);             \
1382 }                                                                       \
1383 static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1384 {                                                                       \
1385         clear_bit(bit + (offset), &EXT4_I(inode)->i_##field);           \
1386 }
1387
1388 EXT4_INODE_BIT_FNS(flag, flags, 0)
1389 #if (BITS_PER_LONG < 64)
1390 EXT4_INODE_BIT_FNS(state, state_flags, 0)
1391
1392 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1393 {
1394         (ei)->i_state_flags = 0;
1395 }
1396 #else
1397 EXT4_INODE_BIT_FNS(state, flags, 32)
1398
1399 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1400 {
1401         /* We depend on the fact that callers will set i_flags */
1402 }
1403 #endif
1404 #else
1405 /* Assume that user mode programs are passing in an ext4fs superblock, not
1406  * a kernel struct super_block.  This will allow us to call the feature-test
1407  * macros from user land. */
1408 #define EXT4_SB(sb)     (sb)
1409 #endif
1410
1411 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1412
1413 /*
1414  * Codes for operating systems
1415  */
1416 #define EXT4_OS_LINUX           0
1417 #define EXT4_OS_HURD            1
1418 #define EXT4_OS_MASIX           2
1419 #define EXT4_OS_FREEBSD         3
1420 #define EXT4_OS_LITES           4
1421
1422 /*
1423  * Revision levels
1424  */
1425 #define EXT4_GOOD_OLD_REV       0       /* The good old (original) format */
1426 #define EXT4_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
1427
1428 #define EXT4_CURRENT_REV        EXT4_GOOD_OLD_REV
1429 #define EXT4_MAX_SUPP_REV       EXT4_DYNAMIC_REV
1430
1431 #define EXT4_GOOD_OLD_INODE_SIZE 128
1432
1433 /*
1434  * Feature set definitions
1435  */
1436
1437 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)                        \
1438         ((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1439 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
1440         ((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1441 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)                      \
1442         ((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1443 #define EXT4_SET_COMPAT_FEATURE(sb,mask)                        \
1444         EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1445 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)                     \
1446         EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1447 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)                      \
1448         EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1449 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)                      \
1450         EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1451 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
1452         EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1453 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
1454         EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1455
1456 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC        0x0001
1457 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES       0x0002
1458 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL         0x0004
1459 #define EXT4_FEATURE_COMPAT_EXT_ATTR            0x0008
1460 #define EXT4_FEATURE_COMPAT_RESIZE_INODE        0x0010
1461 #define EXT4_FEATURE_COMPAT_DIR_INDEX           0x0020
1462
1463 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
1464 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
1465 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
1466 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1467 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM         0x0010
1468 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK        0x0020
1469 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE      0x0040
1470 #define EXT4_FEATURE_RO_COMPAT_QUOTA            0x0100
1471 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC         0x0200
1472 /*
1473  * METADATA_CSUM also enables group descriptor checksums (GDT_CSUM).  When
1474  * METADATA_CSUM is set, group descriptor checksums use the same algorithm as
1475  * all other data structures' checksums.  However, the METADATA_CSUM and
1476  * GDT_CSUM bits are mutually exclusive.
1477  */
1478 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM    0x0400
1479
1480 #define EXT4_FEATURE_INCOMPAT_COMPRESSION       0x0001
1481 #define EXT4_FEATURE_INCOMPAT_FILETYPE          0x0002
1482 #define EXT4_FEATURE_INCOMPAT_RECOVER           0x0004 /* Needs recovery */
1483 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008 /* Journal device */
1484 #define EXT4_FEATURE_INCOMPAT_META_BG           0x0010
1485 #define EXT4_FEATURE_INCOMPAT_EXTENTS           0x0040 /* extents support */
1486 #define EXT4_FEATURE_INCOMPAT_64BIT             0x0080
1487 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1488 #define EXT4_FEATURE_INCOMPAT_FLEX_BG           0x0200
1489 #define EXT4_FEATURE_INCOMPAT_EA_INODE          0x0400 /* EA in inode */
1490 #define EXT4_FEATURE_INCOMPAT_DIRDATA           0x1000 /* data in dirent */
1491 #define EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM  0x2000 /* use crc32c for bg */
1492 #define EXT4_FEATURE_INCOMPAT_LARGEDIR          0x4000 /* >2GB or 3-lvl htree */
1493 #define EXT4_FEATURE_INCOMPAT_INLINE_DATA       0x8000 /* data in inode */
1494
1495 #define EXT2_FEATURE_COMPAT_SUPP        EXT4_FEATURE_COMPAT_EXT_ATTR
1496 #define EXT2_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1497                                          EXT4_FEATURE_INCOMPAT_META_BG)
1498 #define EXT2_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1499                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1500                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1501
1502 #define EXT3_FEATURE_COMPAT_SUPP        EXT4_FEATURE_COMPAT_EXT_ATTR
1503 #define EXT3_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1504                                          EXT4_FEATURE_INCOMPAT_RECOVER| \
1505                                          EXT4_FEATURE_INCOMPAT_META_BG)
1506 #define EXT3_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1507                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1508                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1509
1510 #define EXT4_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
1511 #define EXT4_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1512                                          EXT4_FEATURE_INCOMPAT_RECOVER| \
1513                                          EXT4_FEATURE_INCOMPAT_META_BG| \
1514                                          EXT4_FEATURE_INCOMPAT_EXTENTS| \
1515                                          EXT4_FEATURE_INCOMPAT_64BIT| \
1516                                          EXT4_FEATURE_INCOMPAT_FLEX_BG| \
1517                                          EXT4_FEATURE_INCOMPAT_MMP |    \
1518                                          EXT4_FEATURE_INCOMPAT_INLINE_DATA)
1519 #define EXT4_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1520                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1521                                          EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1522                                          EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1523                                          EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1524                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1525                                          EXT4_FEATURE_RO_COMPAT_HUGE_FILE |\
1526                                          EXT4_FEATURE_RO_COMPAT_BIGALLOC |\
1527                                          EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
1528                                          EXT4_FEATURE_RO_COMPAT_QUOTA)
1529
1530 /*
1531  * Default values for user and/or group using reserved blocks
1532  */
1533 #define EXT4_DEF_RESUID         0
1534 #define EXT4_DEF_RESGID         0
1535
1536 #define EXT4_DEF_INODE_READAHEAD_BLKS   32
1537
1538 /*
1539  * Default mount options
1540  */
1541 #define EXT4_DEFM_DEBUG         0x0001
1542 #define EXT4_DEFM_BSDGROUPS     0x0002
1543 #define EXT4_DEFM_XATTR_USER    0x0004
1544 #define EXT4_DEFM_ACL           0x0008
1545 #define EXT4_DEFM_UID16         0x0010
1546 #define EXT4_DEFM_JMODE         0x0060
1547 #define EXT4_DEFM_JMODE_DATA    0x0020
1548 #define EXT4_DEFM_JMODE_ORDERED 0x0040
1549 #define EXT4_DEFM_JMODE_WBACK   0x0060
1550 #define EXT4_DEFM_NOBARRIER     0x0100
1551 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
1552 #define EXT4_DEFM_DISCARD       0x0400
1553 #define EXT4_DEFM_NODELALLOC    0x0800
1554
1555 /*
1556  * Default journal batch times
1557  */
1558 #define EXT4_DEF_MIN_BATCH_TIME 0
1559 #define EXT4_DEF_MAX_BATCH_TIME 15000 /* 15ms */
1560
1561 /*
1562  * Minimum number of groups in a flexgroup before we separate out
1563  * directories into the first block group of a flexgroup
1564  */
1565 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME 4
1566
1567 /*
1568  * Structure of a directory entry
1569  */
1570 #define EXT4_NAME_LEN 255
1571
1572 struct ext4_dir_entry {
1573         __le32  inode;                  /* Inode number */
1574         __le16  rec_len;                /* Directory entry length */
1575         __le16  name_len;               /* Name length */
1576         char    name[EXT4_NAME_LEN];    /* File name */
1577 };
1578
1579 /*
1580  * The new version of the directory entry.  Since EXT4 structures are
1581  * stored in intel byte order, and the name_len field could never be
1582  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1583  * file_type field.
1584  */
1585 struct ext4_dir_entry_2 {
1586         __le32  inode;                  /* Inode number */
1587         __le16  rec_len;                /* Directory entry length */
1588         __u8    name_len;               /* Name length */
1589         __u8    file_type;
1590         char    name[EXT4_NAME_LEN];    /* File name */
1591 };
1592
1593 /*
1594  * This is a bogus directory entry at the end of each leaf block that
1595  * records checksums.
1596  */
1597 struct ext4_dir_entry_tail {
1598         __le32  det_reserved_zero1;     /* Pretend to be unused */
1599         __le16  det_rec_len;            /* 12 */
1600         __u8    det_reserved_zero2;     /* Zero name length */
1601         __u8    det_reserved_ft;        /* 0xDE, fake file type */
1602         __le32  det_checksum;           /* crc32c(uuid+inum+dirblock) */
1603 };
1604
1605 #define EXT4_DIRENT_TAIL(block, blocksize) \
1606         ((struct ext4_dir_entry_tail *)(((void *)(block)) + \
1607                                         ((blocksize) - \
1608                                          sizeof(struct ext4_dir_entry_tail))))
1609
1610 /*
1611  * Ext4 directory file types.  Only the low 3 bits are used.  The
1612  * other bits are reserved for now.
1613  */
1614 #define EXT4_FT_UNKNOWN         0
1615 #define EXT4_FT_REG_FILE        1
1616 #define EXT4_FT_DIR             2
1617 #define EXT4_FT_CHRDEV          3
1618 #define EXT4_FT_BLKDEV          4
1619 #define EXT4_FT_FIFO            5
1620 #define EXT4_FT_SOCK            6
1621 #define EXT4_FT_SYMLINK         7
1622
1623 #define EXT4_FT_MAX             8
1624
1625 #define EXT4_FT_DIR_CSUM        0xDE
1626
1627 /*
1628  * EXT4_DIR_PAD defines the directory entries boundaries
1629  *
1630  * NOTE: It must be a multiple of 4
1631  */
1632 #define EXT4_DIR_PAD                    4
1633 #define EXT4_DIR_ROUND                  (EXT4_DIR_PAD - 1)
1634 #define EXT4_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT4_DIR_ROUND) & \
1635                                          ~EXT4_DIR_ROUND)
1636 #define EXT4_MAX_REC_LEN                ((1<<16)-1)
1637
1638 /*
1639  * If we ever get support for fs block sizes > page_size, we'll need
1640  * to remove the #if statements in the next two functions...
1641  */
1642 static inline unsigned int
1643 ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
1644 {
1645         unsigned len = le16_to_cpu(dlen);
1646
1647 #if (PAGE_CACHE_SIZE >= 65536)
1648         if (len == EXT4_MAX_REC_LEN || len == 0)
1649                 return blocksize;
1650         return (len & 65532) | ((len & 3) << 16);
1651 #else
1652         return len;
1653 #endif
1654 }
1655
1656 static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
1657 {
1658         if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
1659                 BUG();
1660 #if (PAGE_CACHE_SIZE >= 65536)
1661         if (len < 65536)
1662                 return cpu_to_le16(len);
1663         if (len == blocksize) {
1664                 if (blocksize == 65536)
1665                         return cpu_to_le16(EXT4_MAX_REC_LEN);
1666                 else
1667                         return cpu_to_le16(0);
1668         }
1669         return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
1670 #else
1671         return cpu_to_le16(len);
1672 #endif
1673 }
1674
1675 /*
1676  * Hash Tree Directory indexing
1677  * (c) Daniel Phillips, 2001
1678  */
1679
1680 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1681                                       EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1682                     ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
1683 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1684 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1685
1686 /* Legal values for the dx_root hash_version field: */
1687
1688 #define DX_HASH_LEGACY          0
1689 #define DX_HASH_HALF_MD4        1
1690 #define DX_HASH_TEA             2
1691 #define DX_HASH_LEGACY_UNSIGNED 3
1692 #define DX_HASH_HALF_MD4_UNSIGNED       4
1693 #define DX_HASH_TEA_UNSIGNED            5
1694
1695 static inline u32 ext4_chksum(struct ext4_sb_info *sbi, u32 crc,
1696                               const void *address, unsigned int length)
1697 {
1698         struct {
1699                 struct shash_desc shash;
1700                 char ctx[4];
1701         } desc;
1702         int err;
1703
1704         BUG_ON(crypto_shash_descsize(sbi->s_chksum_driver)!=sizeof(desc.ctx));
1705
1706         desc.shash.tfm = sbi->s_chksum_driver;
1707         desc.shash.flags = 0;
1708         *(u32 *)desc.ctx = crc;
1709
1710         err = crypto_shash_update(&desc.shash, address, length);
1711         BUG_ON(err);
1712
1713         return *(u32 *)desc.ctx;
1714 }
1715
1716 #ifdef __KERNEL__
1717
1718 /* hash info structure used by the directory hash */
1719 struct dx_hash_info
1720 {
1721         u32             hash;
1722         u32             minor_hash;
1723         int             hash_version;
1724         u32             *seed;
1725 };
1726
1727
1728 /* 32 and 64 bit signed EOF for dx directories */
1729 #define EXT4_HTREE_EOF_32BIT   ((1UL  << (32 - 1)) - 1)
1730 #define EXT4_HTREE_EOF_64BIT   ((1ULL << (64 - 1)) - 1)
1731
1732
1733 /*
1734  * Control parameters used by ext4_htree_next_block
1735  */
1736 #define HASH_NB_ALWAYS          1
1737
1738
1739 /*
1740  * Describe an inode's exact location on disk and in memory
1741  */
1742 struct ext4_iloc
1743 {
1744         struct buffer_head *bh;
1745         unsigned long offset;
1746         ext4_group_t block_group;
1747 };
1748
1749 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1750 {
1751         return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1752 }
1753
1754 /*
1755  * This structure is stuffed into the struct file's private_data field
1756  * for directories.  It is where we put information so that we can do
1757  * readdir operations in hash tree order.
1758  */
1759 struct dir_private_info {
1760         struct rb_root  root;
1761         struct rb_node  *curr_node;
1762         struct fname    *extra_fname;
1763         loff_t          last_pos;
1764         __u32           curr_hash;
1765         __u32           curr_minor_hash;
1766         __u32           next_hash;
1767 };
1768
1769 /* calculate the first block number of the group */
1770 static inline ext4_fsblk_t
1771 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1772 {
1773         return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1774                 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1775 }
1776
1777 /*
1778  * Special error return code only used by dx_probe() and its callers.
1779  */
1780 #define ERR_BAD_DX_DIR  -75000
1781
1782 /*
1783  * Timeout and state flag for lazy initialization inode thread.
1784  */
1785 #define EXT4_DEF_LI_WAIT_MULT                   10
1786 #define EXT4_DEF_LI_MAX_START_DELAY             5
1787 #define EXT4_LAZYINIT_QUIT                      0x0001
1788 #define EXT4_LAZYINIT_RUNNING                   0x0002
1789
1790 /*
1791  * Lazy inode table initialization info
1792  */
1793 struct ext4_lazy_init {
1794         unsigned long           li_state;
1795         struct list_head        li_request_list;
1796         struct mutex            li_list_mtx;
1797 };
1798
1799 struct ext4_li_request {
1800         struct super_block      *lr_super;
1801         struct ext4_sb_info     *lr_sbi;
1802         ext4_group_t            lr_next_group;
1803         struct list_head        lr_request;
1804         unsigned long           lr_next_sched;
1805         unsigned long           lr_timeout;
1806 };
1807
1808 struct ext4_features {
1809         struct kobject f_kobj;
1810         struct completion f_kobj_unregister;
1811 };
1812
1813 /*
1814  * This structure will be used for multiple mount protection. It will be
1815  * written into the block number saved in the s_mmp_block field in the
1816  * superblock. Programs that check MMP should assume that if
1817  * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
1818  * to use the filesystem, regardless of how old the timestamp is.
1819  */
1820 #define EXT4_MMP_MAGIC     0x004D4D50U /* ASCII for MMP */
1821 #define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
1822 #define EXT4_MMP_SEQ_FSCK  0xE24D4D50U /* mmp_seq value when being fscked */
1823 #define EXT4_MMP_SEQ_MAX   0xE24D4D4FU /* maximum valid mmp_seq value */
1824
1825 struct mmp_struct {
1826         __le32  mmp_magic;              /* Magic number for MMP */
1827         __le32  mmp_seq;                /* Sequence no. updated periodically */
1828
1829         /*
1830          * mmp_time, mmp_nodename & mmp_bdevname are only used for information
1831          * purposes and do not affect the correctness of the algorithm
1832          */
1833         __le64  mmp_time;               /* Time last updated */
1834         char    mmp_nodename[64];       /* Node which last updated MMP block */
1835         char    mmp_bdevname[32];       /* Bdev which last updated MMP block */
1836
1837         /*
1838          * mmp_check_interval is used to verify if the MMP block has been
1839          * updated on the block device. The value is updated based on the
1840          * maximum time to write the MMP block during an update cycle.
1841          */
1842         __le16  mmp_check_interval;
1843
1844         __le16  mmp_pad1;
1845         __le32  mmp_pad2[226];
1846         __le32  mmp_checksum;           /* crc32c(uuid+mmp_block) */
1847 };
1848
1849 /* arguments passed to the mmp thread */
1850 struct mmpd_data {
1851         struct buffer_head *bh; /* bh from initial read_mmp_block() */
1852         struct super_block *sb;  /* super block of the fs */
1853 };
1854
1855 /*
1856  * Check interval multiplier
1857  * The MMP block is written every update interval and initially checked every
1858  * update interval x the multiplier (the value is then adapted based on the
1859  * write latency). The reason is that writes can be delayed under load and we
1860  * don't want readers to incorrectly assume that the filesystem is no longer
1861  * in use.
1862  */
1863 #define EXT4_MMP_CHECK_MULT             2UL
1864
1865 /*
1866  * Minimum interval for MMP checking in seconds.
1867  */
1868 #define EXT4_MMP_MIN_CHECK_INTERVAL     5UL
1869
1870 /*
1871  * Maximum interval for MMP checking in seconds.
1872  */
1873 #define EXT4_MMP_MAX_CHECK_INTERVAL     300UL
1874
1875 /*
1876  * Function prototypes
1877  */
1878
1879 /*
1880  * Ok, these declarations are also in <linux/kernel.h> but none of the
1881  * ext4 source programs needs to include it so they are duplicated here.
1882  */
1883 # define NORET_TYPE     /**/
1884 # define ATTRIB_NORET   __attribute__((noreturn))
1885 # define NORET_AND      noreturn,
1886
1887 /* bitmap.c */
1888 extern unsigned int ext4_count_free(char *bitmap, unsigned numchars);
1889 void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1890                                 struct ext4_group_desc *gdp,
1891                                 struct buffer_head *bh, int sz);
1892 int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1893                                   struct ext4_group_desc *gdp,
1894                                   struct buffer_head *bh, int sz);
1895 void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1896                                 struct ext4_group_desc *gdp,
1897                                 struct buffer_head *bh);
1898 int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1899                                   struct ext4_group_desc *gdp,
1900                                   struct buffer_head *bh);
1901
1902 /* balloc.c */
1903 extern void ext4_get_group_no_and_offset(struct super_block *sb,
1904                                          ext4_fsblk_t blocknr,
1905                                          ext4_group_t *blockgrpp,
1906                                          ext4_grpblk_t *offsetp);
1907 extern ext4_group_t ext4_get_group_number(struct super_block *sb,
1908                                           ext4_fsblk_t block);
1909
1910 extern void ext4_validate_block_bitmap(struct super_block *sb,
1911                                        struct ext4_group_desc *desc,
1912                                        unsigned int block_group,
1913                                        struct buffer_head *bh);
1914 extern unsigned int ext4_block_group(struct super_block *sb,
1915                         ext4_fsblk_t blocknr);
1916 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1917                         ext4_fsblk_t blocknr);
1918 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1919 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1920                         ext4_group_t group);
1921 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1922                                          ext4_fsblk_t goal,
1923                                          unsigned int flags,
1924                                          unsigned long *count,
1925                                          int *errp);
1926 extern int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
1927                                     s64 nclusters, unsigned int flags);
1928 extern ext4_fsblk_t ext4_count_free_clusters(struct super_block *);
1929 extern void ext4_check_blocks_bitmap(struct super_block *);
1930 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1931                                                     ext4_group_t block_group,
1932                                                     struct buffer_head ** bh);
1933 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1934
1935 extern struct buffer_head *ext4_read_block_bitmap_nowait(struct super_block *sb,
1936                                                 ext4_group_t block_group);
1937 extern int ext4_wait_block_bitmap(struct super_block *sb,
1938                                   ext4_group_t block_group,
1939                                   struct buffer_head *bh);
1940 extern struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1941                                                   ext4_group_t block_group);
1942 extern void ext4_init_block_bitmap(struct super_block *sb,
1943                                    struct buffer_head *bh,
1944                                    ext4_group_t group,
1945                                    struct ext4_group_desc *desc);
1946 extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
1947                                               ext4_group_t block_group,
1948                                               struct ext4_group_desc *gdp);
1949 extern unsigned ext4_num_overhead_clusters(struct super_block *sb,
1950                                            ext4_group_t block_group,
1951                                            struct ext4_group_desc *gdp);
1952 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
1953
1954 /* dir.c */
1955 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
1956                                   struct file *,
1957                                   struct ext4_dir_entry_2 *,
1958                                   struct buffer_head *, char *, int,
1959                                   unsigned int);
1960 #define ext4_check_dir_entry(dir, filp, de, bh, buf, size, offset)      \
1961         unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
1962                                         (de), (bh), (buf), (size), (offset)))
1963 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1964                                     __u32 minor_hash,
1965                                     struct ext4_dir_entry_2 *dirent);
1966 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
1967 extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1968                              struct buffer_head *bh,
1969                              void *buf, int buf_size,
1970                              const char *name, int namelen,
1971                              struct ext4_dir_entry_2 **dest_de);
1972 void ext4_insert_dentry(struct inode *inode,
1973                         struct ext4_dir_entry_2 *de,
1974                         int buf_size,
1975                         const char *name, int namelen);
1976 static inline void ext4_update_dx_flag(struct inode *inode)
1977 {
1978         if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
1979                                      EXT4_FEATURE_COMPAT_DIR_INDEX))
1980                 ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
1981 }
1982 static unsigned char ext4_filetype_table[] = {
1983         DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
1984 };
1985
1986 static inline  unsigned char get_dtype(struct super_block *sb, int filetype)
1987 {
1988         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE) ||
1989             (filetype >= EXT4_FT_MAX))
1990                 return DT_UNKNOWN;
1991
1992         return ext4_filetype_table[filetype];
1993 }
1994
1995 /* fsync.c */
1996 extern int ext4_sync_file(struct file *, loff_t, loff_t, int);
1997 extern int ext4_flush_unwritten_io(struct inode *);
1998
1999 /* hash.c */
2000 extern int ext4fs_dirhash(const char *name, int len, struct
2001                           dx_hash_info *hinfo);
2002
2003 /* ialloc.c */
2004 extern struct inode *__ext4_new_inode(handle_t *, struct inode *, umode_t,
2005                                       const struct qstr *qstr, __u32 goal,
2006                                       uid_t *owner, int handle_type,
2007                                       unsigned int line_no, int nblocks);
2008
2009 #define ext4_new_inode(handle, dir, mode, qstr, goal, owner) \
2010         __ext4_new_inode((handle), (dir), (mode), (qstr), (goal), (owner), \
2011                          0, 0, 0)
2012 #define ext4_new_inode_start_handle(dir, mode, qstr, goal, owner, \
2013                                     type, nblocks)                  \
2014         __ext4_new_inode(NULL, (dir), (mode), (qstr), (goal), (owner), \
2015                          (type), __LINE__, (nblocks))
2016
2017
2018 extern void ext4_free_inode(handle_t *, struct inode *);
2019 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
2020 extern unsigned long ext4_count_free_inodes(struct super_block *);
2021 extern unsigned long ext4_count_dirs(struct super_block *);
2022 extern void ext4_check_inodes_bitmap(struct super_block *);
2023 extern void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
2024 extern int ext4_init_inode_table(struct super_block *sb,
2025                                  ext4_group_t group, int barrier);
2026 extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
2027
2028 /* mballoc.c */
2029 extern long ext4_mb_stats;
2030 extern long ext4_mb_max_to_scan;
2031 extern int ext4_mb_init(struct super_block *);
2032 extern int ext4_mb_release(struct super_block *);
2033 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
2034                                 struct ext4_allocation_request *, int *);
2035 extern int ext4_mb_reserve_blocks(struct super_block *, int);
2036 extern void ext4_discard_preallocations(struct inode *);
2037 extern int __init ext4_init_mballoc(void);
2038 extern void ext4_exit_mballoc(void);
2039 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
2040                              struct buffer_head *bh, ext4_fsblk_t block,
2041                              unsigned long count, int flags);
2042 extern int ext4_mb_alloc_groupinfo(struct super_block *sb,
2043                                    ext4_group_t ngroups);
2044 extern int ext4_mb_add_groupinfo(struct super_block *sb,
2045                 ext4_group_t i, struct ext4_group_desc *desc);
2046 extern int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
2047                                 ext4_fsblk_t block, unsigned long count);
2048 extern int ext4_trim_fs(struct super_block *, struct fstrim_range *);
2049
2050 /* inode.c */
2051 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
2052                                                 ext4_lblk_t, int, int *);
2053 struct buffer_head *ext4_bread(handle_t *, struct inode *,
2054                                                 ext4_lblk_t, int, int *);
2055 int ext4_get_block_write(struct inode *inode, sector_t iblock,
2056                          struct buffer_head *bh_result, int create);
2057 int ext4_get_block(struct inode *inode, sector_t iblock,
2058                                 struct buffer_head *bh_result, int create);
2059 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
2060                            struct buffer_head *bh, int create);
2061 int ext4_walk_page_buffers(handle_t *handle,
2062                            struct buffer_head *head,
2063                            unsigned from,
2064                            unsigned to,
2065                            int *partial,
2066                            int (*fn)(handle_t *handle,
2067                                      struct buffer_head *bh));
2068 int do_journal_get_write_access(handle_t *handle,
2069                                 struct buffer_head *bh);
2070 #define FALL_BACK_TO_NONDELALLOC 1
2071 #define CONVERT_INLINE_DATA      2
2072
2073 extern struct inode *ext4_iget(struct super_block *, unsigned long);
2074 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
2075 extern int  ext4_setattr(struct dentry *, struct iattr *);
2076 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
2077                                 struct kstat *stat);
2078 extern void ext4_evict_inode(struct inode *);
2079 extern void ext4_clear_inode(struct inode *);
2080 extern int  ext4_sync_inode(handle_t *, struct inode *);
2081 extern void ext4_dirty_inode(struct inode *, int);
2082 extern int ext4_change_inode_journal_flag(struct inode *, int);
2083 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
2084 extern int ext4_can_truncate(struct inode *inode);
2085 extern void ext4_truncate(struct inode *);
2086 extern int ext4_punch_hole(struct file *file, loff_t offset, loff_t length);
2087 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
2088 extern void ext4_set_inode_flags(struct inode *);
2089 extern void ext4_get_inode_flags(struct ext4_inode_info *);
2090 extern int ext4_alloc_da_blocks(struct inode *inode);
2091 extern void ext4_set_aops(struct inode *inode);
2092 extern int ext4_writepage_trans_blocks(struct inode *);
2093 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
2094 extern int ext4_block_truncate_page(handle_t *handle,
2095                 struct address_space *mapping, loff_t from);
2096 extern int ext4_block_zero_page_range(handle_t *handle,
2097                 struct address_space *mapping, loff_t from, loff_t length);
2098 extern int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
2099                              loff_t lstart, loff_t lend);
2100 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
2101 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
2102 extern void ext4_da_update_reserve_space(struct inode *inode,
2103                                         int used, int quota_claim);
2104
2105 /* indirect.c */
2106 extern int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
2107                                 struct ext4_map_blocks *map, int flags);
2108 extern ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb,
2109                                 const struct iovec *iov, loff_t offset,
2110                                 unsigned long nr_segs);
2111 extern int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock);
2112 extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks);
2113 extern void ext4_ind_truncate(handle_t *, struct inode *inode);
2114 extern int ext4_free_hole_blocks(handle_t *handle, struct inode *inode,
2115                                  ext4_lblk_t first, ext4_lblk_t stop);
2116
2117 /* ioctl.c */
2118 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
2119 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
2120
2121 /* migrate.c */
2122 extern int ext4_ext_migrate(struct inode *);
2123 extern int ext4_ind_migrate(struct inode *inode);
2124
2125 /* namei.c */
2126 extern int ext4_dirent_csum_verify(struct inode *inode,
2127                                    struct ext4_dir_entry *dirent);
2128 extern int ext4_orphan_add(handle_t *, struct inode *);
2129 extern int ext4_orphan_del(handle_t *, struct inode *);
2130 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
2131                                 __u32 start_minor_hash, __u32 *next_hash);
2132 extern int search_dir(struct buffer_head *bh,
2133                       char *search_buf,
2134                       int buf_size,
2135                       struct inode *dir,
2136                       const struct qstr *d_name,
2137                       unsigned int offset,
2138                       struct ext4_dir_entry_2 **res_dir);
2139 extern int ext4_generic_delete_entry(handle_t *handle,
2140                                      struct inode *dir,
2141                                      struct ext4_dir_entry_2 *de_del,
2142                                      struct buffer_head *bh,
2143                                      void *entry_buf,
2144                                      int buf_size,
2145                                      int csum_size);
2146
2147 /* resize.c */
2148 extern int ext4_group_add(struct super_block *sb,
2149                                 struct ext4_new_group_data *input);
2150 extern int ext4_group_extend(struct super_block *sb,
2151                                 struct ext4_super_block *es,
2152                                 ext4_fsblk_t n_blocks_count);
2153 extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
2154
2155 /* super.c */
2156 extern int ext4_calculate_overhead(struct super_block *sb);
2157 extern int ext4_superblock_csum_verify(struct super_block *sb,
2158                                        struct ext4_super_block *es);
2159 extern void ext4_superblock_csum_set(struct super_block *sb);
2160 extern void *ext4_kvmalloc(size_t size, gfp_t flags);
2161 extern void *ext4_kvzalloc(size_t size, gfp_t flags);
2162 extern void ext4_kvfree(void *ptr);
2163 extern int ext4_alloc_flex_bg_array(struct super_block *sb,
2164                                     ext4_group_t ngroup);
2165 extern const char *ext4_decode_error(struct super_block *sb, int errno,
2166                                      char nbuf[16]);
2167 extern __printf(4, 5)
2168 void __ext4_error(struct super_block *, const char *, unsigned int,
2169                   const char *, ...);
2170 #define ext4_error(sb, message...)      __ext4_error(sb, __func__,      \
2171                                                      __LINE__, ## message)
2172 extern __printf(5, 6)
2173 void ext4_error_inode(struct inode *, const char *, unsigned int, ext4_fsblk_t,
2174                       const char *, ...);
2175 extern __printf(5, 6)
2176 void ext4_error_file(struct file *, const char *, unsigned int, ext4_fsblk_t,
2177                      const char *, ...);
2178 extern void __ext4_std_error(struct super_block *, const char *,
2179                              unsigned int, int);
2180 extern __printf(4, 5)
2181 void __ext4_abort(struct super_block *, const char *, unsigned int,
2182                   const char *, ...);
2183 #define ext4_abort(sb, message...)      __ext4_abort(sb, __func__, \
2184                                                        __LINE__, ## message)
2185 extern __printf(4, 5)
2186 void __ext4_warning(struct super_block *, const char *, unsigned int,
2187                     const char *, ...);
2188 #define ext4_warning(sb, message...)    __ext4_warning(sb, __func__, \
2189                                                        __LINE__, ## message)
2190 extern __printf(3, 4)
2191 void ext4_msg(struct super_block *, const char *, const char *, ...);
2192 extern void __dump_mmp_msg(struct super_block *, struct mmp_struct *mmp,
2193                            const char *, unsigned int, const char *);
2194 #define dump_mmp_msg(sb, mmp, msg)      __dump_mmp_msg(sb, mmp, __func__, \
2195                                                        __LINE__, msg)
2196 extern __printf(7, 8)
2197 void __ext4_grp_locked_error(const char *, unsigned int,
2198                              struct super_block *, ext4_group_t,
2199                              unsigned long, ext4_fsblk_t,
2200                              const char *, ...);
2201 #define ext4_grp_locked_error(sb, grp, message...) \
2202         __ext4_grp_locked_error(__func__, __LINE__, (sb), (grp), ## message)
2203 extern void ext4_update_dynamic_rev(struct super_block *sb);
2204 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
2205                                         __u32 compat);
2206 extern int ext4_update_rocompat_feature(handle_t *handle,
2207                                         struct super_block *sb, __u32 rocompat);
2208 extern int ext4_update_incompat_feature(handle_t *handle,
2209                                         struct super_block *sb, __u32 incompat);
2210 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
2211                                       struct ext4_group_desc *bg);
2212 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
2213                                       struct ext4_group_desc *bg);
2214 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
2215                                      struct ext4_group_desc *bg);
2216 extern __u32 ext4_free_group_clusters(struct super_block *sb,
2217                                       struct ext4_group_desc *bg);
2218 extern __u32 ext4_free_inodes_count(struct super_block *sb,
2219                                  struct ext4_group_desc *bg);
2220 extern __u32 ext4_used_dirs_count(struct super_block *sb,
2221                                 struct ext4_group_desc *bg);
2222 extern __u32 ext4_itable_unused_count(struct super_block *sb,
2223                                    struct ext4_group_desc *bg);
2224 extern void ext4_block_bitmap_set(struct super_block *sb,
2225                                   struct ext4_group_desc *bg, ext4_fsblk_t blk);
2226 extern void ext4_inode_bitmap_set(struct super_block *sb,
2227                                   struct ext4_group_desc *bg, ext4_fsblk_t blk);
2228 extern void ext4_inode_table_set(struct super_block *sb,
2229                                  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2230 extern void ext4_free_group_clusters_set(struct super_block *sb,
2231                                          struct ext4_group_desc *bg,
2232                                          __u32 count);
2233 extern void ext4_free_inodes_set(struct super_block *sb,
2234                                 struct ext4_group_desc *bg, __u32 count);
2235 extern void ext4_used_dirs_set(struct super_block *sb,
2236                                 struct ext4_group_desc *bg, __u32 count);
2237 extern void ext4_itable_unused_set(struct super_block *sb,
2238                                    struct ext4_group_desc *bg, __u32 count);
2239 extern int ext4_group_desc_csum_verify(struct super_block *sb, __u32 group,
2240                                        struct ext4_group_desc *gdp);
2241 extern void ext4_group_desc_csum_set(struct super_block *sb, __u32 group,
2242                                      struct ext4_group_desc *gdp);
2243 extern int ext4_register_li_request(struct super_block *sb,
2244                                     ext4_group_t first_not_zeroed);
2245
2246 static inline int ext4_has_group_desc_csum(struct super_block *sb)
2247 {
2248         return EXT4_HAS_RO_COMPAT_FEATURE(sb,
2249                                           EXT4_FEATURE_RO_COMPAT_GDT_CSUM |
2250                                           EXT4_FEATURE_RO_COMPAT_METADATA_CSUM);
2251 }
2252
2253 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
2254 {
2255         return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
2256                 le32_to_cpu(es->s_blocks_count_lo);
2257 }
2258
2259 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
2260 {
2261         return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
2262                 le32_to_cpu(es->s_r_blocks_count_lo);
2263 }
2264
2265 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
2266 {
2267         return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
2268                 le32_to_cpu(es->s_free_blocks_count_lo);
2269 }
2270
2271 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
2272                                          ext4_fsblk_t blk)
2273 {
2274         es->s_blocks_count_lo = cpu_to_le32((u32)blk);
2275         es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
2276 }
2277
2278 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
2279                                               ext4_fsblk_t blk)
2280 {
2281         es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
2282         es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
2283 }
2284
2285 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
2286                                            ext4_fsblk_t blk)
2287 {
2288         es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
2289         es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
2290 }
2291
2292 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
2293 {
2294         if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
2295                 return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
2296                         le32_to_cpu(raw_inode->i_size_lo);
2297         else
2298                 return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
2299 }
2300
2301 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
2302 {
2303         raw_inode->i_size_lo = cpu_to_le32(i_size);
2304         raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
2305 }
2306
2307 static inline
2308 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
2309                                             ext4_group_t group)
2310 {
2311          struct ext4_group_info ***grp_info;
2312          long indexv, indexh;
2313          grp_info = EXT4_SB(sb)->s_group_info;
2314          indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
2315          indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
2316          return grp_info[indexv][indexh];
2317 }
2318
2319 /*
2320  * Reading s_groups_count requires using smp_rmb() afterwards.  See
2321  * the locking protocol documented in the comments of ext4_group_add()
2322  * in resize.c
2323  */
2324 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
2325 {
2326         ext4_group_t    ngroups = EXT4_SB(sb)->s_groups_count;
2327
2328         smp_rmb();
2329         return ngroups;
2330 }
2331
2332 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
2333                                              ext4_group_t block_group)
2334 {
2335         return block_group >> sbi->s_log_groups_per_flex;
2336 }
2337
2338 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
2339 {
2340         return 1 << sbi->s_log_groups_per_flex;
2341 }
2342
2343 #define ext4_std_error(sb, errno)                               \
2344 do {                                                            \
2345         if ((errno))                                            \
2346                 __ext4_std_error((sb), __func__, __LINE__, (errno));    \
2347 } while (0)
2348
2349 #ifdef CONFIG_SMP
2350 /* Each CPU can accumulate percpu_counter_batch clusters in their local
2351  * counters. So we need to make sure we have free clusters more
2352  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
2353  */
2354 #define EXT4_FREECLUSTERS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
2355 #else
2356 #define EXT4_FREECLUSTERS_WATERMARK 0
2357 #endif
2358
2359 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
2360 {
2361         /*
2362          * XXX: replace with spinlock if seen contended -bzzz
2363          */
2364         down_write(&EXT4_I(inode)->i_data_sem);
2365         if (newsize > EXT4_I(inode)->i_disksize)
2366                 EXT4_I(inode)->i_disksize = newsize;
2367         up_write(&EXT4_I(inode)->i_data_sem);
2368         return ;
2369 }
2370
2371 struct ext4_group_info {
2372         unsigned long   bb_state;
2373         struct rb_root  bb_free_root;
2374         ext4_grpblk_t   bb_first_free;  /* first free block */
2375         ext4_grpblk_t   bb_free;        /* total free blocks */
2376         ext4_grpblk_t   bb_fragments;   /* nr of freespace fragments */
2377         ext4_grpblk_t   bb_largest_free_order;/* order of largest frag in BG */
2378         struct          list_head bb_prealloc_list;
2379 #ifdef DOUBLE_CHECK
2380         void            *bb_bitmap;
2381 #endif
2382         struct rw_semaphore alloc_sem;
2383         ext4_grpblk_t   bb_counters[];  /* Nr of free power-of-two-block
2384                                          * regions, index is order.
2385                                          * bb_counters[3] = 5 means
2386                                          * 5 free 8-block regions. */
2387 };
2388
2389 #define EXT4_GROUP_INFO_NEED_INIT_BIT           0
2390 #define EXT4_GROUP_INFO_WAS_TRIMMED_BIT         1
2391
2392 #define EXT4_MB_GRP_NEED_INIT(grp)      \
2393         (test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
2394
2395 #define EXT4_MB_GRP_WAS_TRIMMED(grp)    \
2396         (test_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2397 #define EXT4_MB_GRP_SET_TRIMMED(grp)    \
2398         (set_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2399 #define EXT4_MB_GRP_CLEAR_TRIMMED(grp)  \
2400         (clear_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2401
2402 #define EXT4_MAX_CONTENTION             8
2403 #define EXT4_CONTENTION_THRESHOLD       2
2404
2405 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
2406                                               ext4_group_t group)
2407 {
2408         return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
2409 }
2410
2411 /*
2412  * Returns true if the filesystem is busy enough that attempts to
2413  * access the block group locks has run into contention.
2414  */
2415 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
2416 {
2417         return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
2418 }
2419
2420 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
2421 {
2422         spinlock_t *lock = ext4_group_lock_ptr(sb, group);
2423         if (spin_trylock(lock))
2424                 /*
2425                  * We're able to grab the lock right away, so drop the
2426                  * lock contention counter.
2427                  */
2428                 atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
2429         else {
2430                 /*
2431                  * The lock is busy, so bump the contention counter,
2432                  * and then wait on the spin lock.
2433                  */
2434                 atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
2435                                   EXT4_MAX_CONTENTION);
2436                 spin_lock(lock);
2437         }
2438 }
2439
2440 static inline void ext4_unlock_group(struct super_block *sb,
2441                                         ext4_group_t group)
2442 {
2443         spin_unlock(ext4_group_lock_ptr(sb, group));
2444 }
2445
2446 /*
2447  * Block validity checking
2448  */
2449 #define ext4_check_indirect_blockref(inode, bh)                         \
2450         ext4_check_blockref(__func__, __LINE__, inode,                  \
2451                             (__le32 *)(bh)->b_data,                     \
2452                             EXT4_ADDR_PER_BLOCK((inode)->i_sb))
2453
2454 #define ext4_ind_check_inode(inode)                                     \
2455         ext4_check_blockref(__func__, __LINE__, inode,                  \
2456                             EXT4_I(inode)->i_data,                      \
2457                             EXT4_NDIR_BLOCKS)
2458
2459 /*
2460  * Inodes and files operations
2461  */
2462
2463 /* dir.c */
2464 extern const struct file_operations ext4_dir_operations;
2465
2466 /* file.c */
2467 extern const struct inode_operations ext4_file_inode_operations;
2468 extern const struct file_operations ext4_file_operations;
2469 extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
2470 extern void ext4_unwritten_wait(struct inode *inode);
2471
2472 /* inline.c */
2473 extern int ext4_has_inline_data(struct inode *inode);
2474 extern int ext4_get_inline_size(struct inode *inode);
2475 extern int ext4_get_max_inline_size(struct inode *inode);
2476 extern int ext4_find_inline_data_nolock(struct inode *inode);
2477 extern void ext4_write_inline_data(struct inode *inode,
2478                                    struct ext4_iloc *iloc,
2479                                    void *buffer, loff_t pos,
2480                                    unsigned int len);
2481 extern int ext4_prepare_inline_data(handle_t *handle, struct inode *inode,
2482                                     unsigned int len);
2483 extern int ext4_init_inline_data(handle_t *handle, struct inode *inode,
2484                                  unsigned int len);
2485 extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);
2486
2487 extern int ext4_readpage_inline(struct inode *inode, struct page *page);
2488 extern int ext4_try_to_write_inline_data(struct address_space *mapping,
2489                                          struct inode *inode,
2490                                          loff_t pos, unsigned len,
2491                                          unsigned flags,
2492                                          struct page **pagep);
2493 extern int ext4_write_inline_data_end(struct inode *inode,
2494                                       loff_t pos, unsigned len,
2495                                       unsigned copied,
2496                                       struct page *page);
2497 extern struct buffer_head *
2498 ext4_journalled_write_inline_data(struct inode *inode,
2499                                   unsigned len,
2500                                   struct page *page);
2501 extern int ext4_da_write_inline_data_begin(struct address_space *mapping,
2502                                            struct inode *inode,
2503                                            loff_t pos, unsigned len,
2504                                            unsigned flags,
2505                                            struct page **pagep,
2506                                            void **fsdata);
2507 extern int ext4_da_write_inline_data_end(struct inode *inode, loff_t pos,
2508                                          unsigned len, unsigned copied,
2509                                          struct page *page);
2510 extern int ext4_try_add_inline_entry(handle_t *handle, struct dentry *dentry,
2511                                      struct inode *inode);
2512 extern int ext4_try_create_inline_dir(handle_t *handle,
2513                                       struct inode *parent,
2514                                       struct inode *inode);
2515 extern int ext4_read_inline_dir(struct file *filp,
2516                                 void *dirent, filldir_t filldir,
2517                                 int *has_inline_data);
2518 extern int htree_inlinedir_to_tree(struct file *dir_file,
2519                                    struct inode *dir, ext4_lblk_t block,
2520                                    struct dx_hash_info *hinfo,
2521                                    __u32 start_hash, __u32 start_minor_hash,
2522                                    int *has_inline_data);
2523 extern struct buffer_head *ext4_find_inline_entry(struct inode *dir,
2524                                         const struct qstr *d_name,
2525                                         struct ext4_dir_entry_2 **res_dir,
2526                                         int *has_inline_data);
2527 extern int ext4_delete_inline_entry(handle_t *handle,
2528                                     struct inode *dir,
2529                                     struct ext4_dir_entry_2 *de_del,
2530                                     struct buffer_head *bh,
2531                                     int *has_inline_data);
2532 extern int empty_inline_dir(struct inode *dir, int *has_inline_data);
2533 extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
2534                                         struct ext4_dir_entry_2 **parent_de,
2535                                         int *retval);
2536 extern int ext4_inline_data_fiemap(struct inode *inode,
2537                                    struct fiemap_extent_info *fieinfo,
2538                                    int *has_inline);
2539 extern int ext4_try_to_evict_inline_data(handle_t *handle,
2540                                          struct inode *inode,
2541                                          int needed);
2542 extern void ext4_inline_data_truncate(struct inode *inode, int *has_inline);
2543
2544 extern int ext4_convert_inline_data(struct inode *inode);
2545
2546 /* namei.c */
2547 extern const struct inode_operations ext4_dir_inode_operations;
2548 extern const struct inode_operations ext4_special_inode_operations;
2549 extern struct dentry *ext4_get_parent(struct dentry *child);
2550 extern struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2551                                  struct ext4_dir_entry_2 *de,
2552                                  int blocksize, int csum_size,
2553                                  unsigned int parent_ino, int dotdot_real_len);
2554 extern void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
2555                                    unsigned int blocksize);
2556 extern int ext4_handle_dirty_dirent_node(handle_t *handle,
2557                                          struct inode *inode,
2558                                          struct buffer_head *bh);
2559 #define S_SHIFT 12
2560 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
2561         [S_IFREG >> S_SHIFT]    = EXT4_FT_REG_FILE,
2562         [S_IFDIR >> S_SHIFT]    = EXT4_FT_DIR,
2563         [S_IFCHR >> S_SHIFT]    = EXT4_FT_CHRDEV,
2564         [S_IFBLK >> S_SHIFT]    = EXT4_FT_BLKDEV,
2565         [S_IFIFO >> S_SHIFT]    = EXT4_FT_FIFO,
2566         [S_IFSOCK >> S_SHIFT]   = EXT4_FT_SOCK,
2567         [S_IFLNK >> S_SHIFT]    = EXT4_FT_SYMLINK,
2568 };
2569
2570 static inline void ext4_set_de_type(struct super_block *sb,
2571                                 struct ext4_dir_entry_2 *de,
2572                                 umode_t mode) {
2573         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
2574                 de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
2575 }
2576
2577
2578 /* symlink.c */
2579 extern const struct inode_operations ext4_symlink_inode_operations;
2580 extern const struct inode_operations ext4_fast_symlink_inode_operations;
2581
2582 /* block_validity */
2583 extern void ext4_release_system_zone(struct super_block *sb);
2584 extern int ext4_setup_system_zone(struct super_block *sb);
2585 extern int __init ext4_init_system_zone(void);
2586 extern void ext4_exit_system_zone(void);
2587 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
2588                                  ext4_fsblk_t start_blk,
2589                                  unsigned int count);
2590 extern int ext4_check_blockref(const char *, unsigned int,
2591                                struct inode *, __le32 *, unsigned int);
2592
2593 /* extents.c */
2594 struct ext4_ext_path;
2595 struct ext4_extent;
2596
2597 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
2598 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
2599 extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks,
2600                                        int chunk);
2601 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
2602                                struct ext4_map_blocks *map, int flags);
2603 extern void ext4_ext_truncate(handle_t *, struct inode *);
2604 extern int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2605                                  ext4_lblk_t end);
2606 extern void ext4_ext_init(struct super_block *);
2607 extern void ext4_ext_release(struct super_block *);
2608 extern long ext4_fallocate(struct file *file, int mode, loff_t offset,
2609                           loff_t len);
2610 extern int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
2611                           ssize_t len);
2612 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
2613                            struct ext4_map_blocks *map, int flags);
2614 extern int ext4_ext_calc_metadata_amount(struct inode *inode,
2615                                          ext4_lblk_t lblocks);
2616 extern int ext4_extent_tree_init(handle_t *, struct inode *);
2617 extern int ext4_ext_calc_credits_for_single_extent(struct inode *inode,
2618                                                    int num,
2619                                                    struct ext4_ext_path *path);
2620 extern int ext4_can_extents_be_merged(struct inode *inode,
2621                                       struct ext4_extent *ex1,
2622                                       struct ext4_extent *ex2);
2623 extern int ext4_ext_insert_extent(handle_t *, struct inode *,
2624                                   struct ext4_ext_path *,
2625                                   struct ext4_extent *, int);
2626 extern struct ext4_ext_path *ext4_ext_find_extent(struct inode *, ext4_lblk_t,
2627                                                   struct ext4_ext_path *);
2628 extern void ext4_ext_drop_refs(struct ext4_ext_path *);
2629 extern int ext4_ext_check_inode(struct inode *inode);
2630 extern int ext4_find_delalloc_range(struct inode *inode,
2631                                     ext4_lblk_t lblk_start,
2632                                     ext4_lblk_t lblk_end);
2633 extern int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk);
2634 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
2635                         __u64 start, __u64 len);
2636
2637
2638 /* move_extent.c */
2639 extern void ext4_double_down_write_data_sem(struct inode *first,
2640                                             struct inode *second);
2641 extern void ext4_double_up_write_data_sem(struct inode *orig_inode,
2642                                           struct inode *donor_inode);
2643 void ext4_inode_double_lock(struct inode *inode1, struct inode *inode2);
2644 void ext4_inode_double_unlock(struct inode *inode1, struct inode *inode2);
2645 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
2646                              __u64 start_orig, __u64 start_donor,
2647                              __u64 len, __u64 *moved_len);
2648
2649 /* page-io.c */
2650 extern int __init ext4_init_pageio(void);
2651 extern void ext4_exit_pageio(void);
2652 extern void ext4_ioend_shutdown(struct inode *);
2653 extern ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags);
2654 extern ext4_io_end_t *ext4_get_io_end(ext4_io_end_t *io_end);
2655 extern int ext4_put_io_end(ext4_io_end_t *io_end);
2656 extern void ext4_put_io_end_defer(ext4_io_end_t *io_end);
2657 extern void ext4_io_submit_init(struct ext4_io_submit *io,
2658                                 struct writeback_control *wbc);
2659 extern void ext4_end_io_work(struct work_struct *work);
2660 extern void ext4_io_submit(struct ext4_io_submit *io);
2661 extern int ext4_bio_write_page(struct ext4_io_submit *io,
2662                                struct page *page,
2663                                int len,
2664                                struct writeback_control *wbc);
2665
2666 /* mmp.c */
2667 extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
2668 extern void ext4_mmp_csum_set(struct super_block *sb, struct mmp_struct *mmp);
2669 extern int ext4_mmp_csum_verify(struct super_block *sb,
2670                                 struct mmp_struct *mmp);
2671
2672 /* BH_Uninit flag: blocks are allocated but uninitialized on disk */
2673 enum ext4_state_bits {
2674         BH_Uninit       /* blocks are allocated but uninitialized on disk */
2675           = BH_JBDPrivateStart,
2676         BH_AllocFromCluster,    /* allocated blocks were part of already
2677                                  * allocated cluster. Note that this flag will
2678                                  * never, ever appear in a buffer_head's state
2679                                  * flag. See EXT4_MAP_FROM_CLUSTER to see where
2680                                  * this is used. */
2681 };
2682
2683 BUFFER_FNS(Uninit, uninit)
2684 TAS_BUFFER_FNS(Uninit, uninit)
2685
2686 /*
2687  * Add new method to test whether block and inode bitmaps are properly
2688  * initialized. With uninit_bg reading the block from disk is not enough
2689  * to mark the bitmap uptodate. We need to also zero-out the bitmap
2690  */
2691 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
2692
2693 static inline int bitmap_uptodate(struct buffer_head *bh)
2694 {
2695         return (buffer_uptodate(bh) &&
2696                         test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
2697 }
2698 static inline void set_bitmap_uptodate(struct buffer_head *bh)
2699 {
2700         set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
2701 }
2702
2703 /*
2704  * Disable DIO read nolock optimization, so new dioreaders will be forced
2705  * to grab i_mutex
2706  */
2707 static inline void ext4_inode_block_unlocked_dio(struct inode *inode)
2708 {
2709         ext4_set_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
2710         smp_mb();
2711 }
2712 static inline void ext4_inode_resume_unlocked_dio(struct inode *inode)
2713 {
2714         smp_mb();
2715         ext4_clear_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
2716 }
2717
2718 #define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
2719
2720 /* For ioend & aio unwritten conversion wait queues */
2721 #define EXT4_WQ_HASH_SZ         37
2722 #define ext4_ioend_wq(v)   (&ext4__ioend_wq[((unsigned long)(v)) %\
2723                                             EXT4_WQ_HASH_SZ])
2724 #define ext4_aio_mutex(v)  (&ext4__aio_mutex[((unsigned long)(v)) %\
2725                                              EXT4_WQ_HASH_SZ])
2726 extern wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
2727 extern struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
2728
2729 #define EXT4_RESIZING   0
2730 extern int ext4_resize_begin(struct super_block *sb);
2731 extern void ext4_resize_end(struct super_block *sb);
2732
2733 #endif  /* __KERNEL__ */
2734
2735 #endif  /* _EXT4_H */