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 <linux/ratelimit.h>
  33 #include <crypto/hash.h>
  34 #ifdef __KERNEL__
  35 #include <linux/compat.h>
  36 #endif
  37
  38 /*
  39  * The fourth extended filesystem constants/structures
  40  */
  41
  42 /*
  43  * Define EXT4FS_DEBUG to produce debug messages
  44  */
  45 #undef EXT4FS_DEBUG
  46
  47 /*
  48  * Debug code
  49  */
  50 #ifdef EXT4FS_DEBUG
  51 #define ext4_debug(f, a...)                                             \
  52         do {                                                            \
  53                 printk(KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:",        \
  54                         __FILE__, __LINE__, __func__);                  \
  55                 printk(KERN_DEBUG f, ## a);                             \
  56         } while (0)
  57 #else
  58 #define ext4_debug(fmt, ...)    no_printk(fmt, ##__VA_ARGS__)
  59 #endif
  60
  61 /*
  62  * Turn on EXT_DEBUG to get lots of info about extents operations.
  63  */
  64 #define EXT_DEBUG__
  65 #ifdef EXT_DEBUG
  66 #define ext_debug(fmt, ...)     printk(fmt, ##__VA_ARGS__)
  67 #else
  68 #define ext_debug(fmt, ...)     no_printk(fmt, ##__VA_ARGS__)
  69 #endif
  70
  71 #define EXT4_ERROR_INODE(inode, fmt, a...) \
  72         ext4_error_inode((inode), __func__, __LINE__, 0, (fmt), ## a)
  73
  74 #define EXT4_ERROR_INODE_BLOCK(inode, block, fmt, a...)                 \
  75         ext4_error_inode((inode), __func__, __LINE__, (block), (fmt), ## a)
  76
  77 #define EXT4_ERROR_FILE(file, block, fmt, a...)                         \
  78         ext4_error_file((file), __func__, __LINE__, (block), (fmt), ## a)
  79
  80 /* data type for block offset of block group */
  81 typedef int ext4_grpblk_t;
  82
  83 /* data type for filesystem-wide blocks number */
  84 typedef unsigned long long ext4_fsblk_t;
  85
  86 /* data type for file logical block number */
  87 typedef __u32 ext4_lblk_t;
  88
  89 /* data type for block group number */
  90 typedef unsigned int ext4_group_t;
  91
  92 /*
  93  * Flags used in mballoc's allocation_context flags field.
  94  *
  95  * Also used to show what's going on for debugging purposes when the
  96  * flag field is exported via the traceport interface
  97  */
  98
  99 /* prefer goal again. length */
 100 #define EXT4_MB_HINT_MERGE              0x0001
 101 /* blocks already reserved */
 102 #define EXT4_MB_HINT_RESERVED           0x0002
 103 /* metadata is being allocated */
 104 #define EXT4_MB_HINT_METADATA           0x0004
 105 /* first blocks in the file */
 106 #define EXT4_MB_HINT_FIRST              0x0008
 107 /* search for the best chunk */
 108 #define EXT4_MB_HINT_BEST               0x0010
 109 /* data is being allocated */
 110 #define EXT4_MB_HINT_DATA               0x0020
 111 /* don't preallocate (for tails) */
 112 #define EXT4_MB_HINT_NOPREALLOC         0x0040
 113 /* allocate for locality group */
 114 #define EXT4_MB_HINT_GROUP_ALLOC        0x0080
 115 /* allocate goal blocks or none */
 116 #define EXT4_MB_HINT_GOAL_ONLY          0x0100
 117 /* goal is meaningful */
 118 #define EXT4_MB_HINT_TRY_GOAL           0x0200
 119 /* blocks already pre-reserved by delayed allocation */
 120 #define EXT4_MB_DELALLOC_RESERVED       0x0400
 121 /* We are doing stream allocation */
 122 #define EXT4_MB_STREAM_ALLOC            0x0800
 123 /* Use reserved root blocks if needed */
 124 #define EXT4_MB_USE_ROOT_BLOCKS         0x1000
 125 /* Use blocks from reserved pool */
 126 #define EXT4_MB_USE_RESERVED            0x2000
 127
 128 struct ext4_allocation_request {
 129         /* target inode for block we're allocating */
 130         struct inode *inode;
 131         /* how many blocks we want to allocate */
 132         unsigned int len;
 133         /* logical block in target inode */
 134         ext4_lblk_t logical;
 135         /* the closest logical allocated block to the left */
 136         ext4_lblk_t lleft;
 137         /* the closest logical allocated block to the right */
 138         ext4_lblk_t lright;
 139         /* phys. target (a hint) */
 140         ext4_fsblk_t goal;
 141         /* phys. block for the closest logical allocated block to the left */
 142         ext4_fsblk_t pleft;
 143         /* phys. block for the closest logical allocated block to the right */
 144         ext4_fsblk_t pright;
 145         /* flags. see above EXT4_MB_HINT_* */
 146         unsigned int flags;
 147 };
 148
 149 /*
 150  * Logical to physical block mapping, used by ext4_map_blocks()
 151  *
 152  * This structure is used to pass requests into ext4_map_blocks() as
 153  * well as to store the information returned by ext4_map_blocks().  It
 154  * takes less room on the stack than a struct buffer_head.
 155  */
 156 #define EXT4_MAP_NEW            (1 << BH_New)
 157 #define EXT4_MAP_MAPPED         (1 << BH_Mapped)
 158 #define EXT4_MAP_UNWRITTEN      (1 << BH_Unwritten)
 159 #define EXT4_MAP_BOUNDARY       (1 << BH_Boundary)
 160 #define EXT4_MAP_UNINIT         (1 << BH_Uninit)
 161 /* Sometimes (in the bigalloc case, from ext4_da_get_block_prep) the caller of
 162  * ext4_map_blocks wants to know whether or not the underlying cluster has
 163  * already been accounted for. EXT4_MAP_FROM_CLUSTER conveys to the caller that
 164  * the requested mapping was from previously mapped (or delayed allocated)
 165  * cluster. We use BH_AllocFromCluster only for this flag. BH_AllocFromCluster
 166  * should never appear on buffer_head's state flags.
 167  */
 168 #define EXT4_MAP_FROM_CLUSTER   (1 << BH_AllocFromCluster)
 169 #define EXT4_MAP_FLAGS          (EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
 170                                  EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY |\
 171                                  EXT4_MAP_UNINIT | EXT4_MAP_FROM_CLUSTER)
 172
 173 struct ext4_map_blocks {
 174         ext4_fsblk_t m_pblk;
 175         ext4_lblk_t m_lblk;
 176         unsigned int m_len;
 177         unsigned int m_flags;
 178 };
 179
 180 /*
 181  * Flags for ext4_io_end->flags
 182  */
 183 #define EXT4_IO_END_UNWRITTEN   0x0001
 184
 185 /*
 186  * For converting uninitialized extents on a work queue. 'handle' is used for
 187  * buffered writeback.
 188  */
 189 typedef struct ext4_io_end {
 190         struct list_head        list;           /* per-file finished IO list */
 191         handle_t                *handle;        /* handle reserved for extent
 192                                                  * conversion */
 193         struct inode            *inode;         /* file being written to */
 194         struct bio              *bio;           /* Linked list of completed
 195                                                  * bios covering the extent */
 196         unsigned int            flag;           /* unwritten or not */
 197         loff_t                  offset;         /* offset in the file */
 198         ssize_t                 size;           /* size of the extent */
 199         atomic_t                count;          /* reference counter */
 200 } ext4_io_end_t;
 201
 202 struct ext4_io_submit {
 203         int                     io_op;
 204         struct bio              *io_bio;
 205         ext4_io_end_t           *io_end;
 206         sector_t                io_next_block;
 207 };
 208
 209 /*
 210  * Special inodes numbers
 211  */
 212 #define EXT4_BAD_INO             1      /* Bad blocks inode */
 213 #define EXT4_ROOT_INO            2      /* Root inode */
 214 #define EXT4_USR_QUOTA_INO       3      /* User quota inode */
 215 #define EXT4_GRP_QUOTA_INO       4      /* Group quota inode */
 216 #define EXT4_BOOT_LOADER_INO     5      /* Boot loader inode */
 217 #define EXT4_UNDEL_DIR_INO       6      /* Undelete directory inode */
 218 #define EXT4_RESIZE_INO          7      /* Reserved group descriptors inode */
 219 #define EXT4_JOURNAL_INO         8      /* Journal inode */
 220
 221 /* First non-reserved inode for old ext4 filesystems */
 222 #define EXT4_GOOD_OLD_FIRST_INO 11
 223
 224 /*
 225  * Maximal count of links to a file
 226  */
 227 #define EXT4_LINK_MAX           65000
 228
 229 /*
 230  * Macro-instructions used to manage several block sizes
 231  */
 232 #define EXT4_MIN_BLOCK_SIZE             1024
 233 #define EXT4_MAX_BLOCK_SIZE             65536
 234 #define EXT4_MIN_BLOCK_LOG_SIZE         10
 235 #define EXT4_MAX_BLOCK_LOG_SIZE         16
 236 #ifdef __KERNEL__
 237 # define EXT4_BLOCK_SIZE(s)             ((s)->s_blocksize)
 238 #else
 239 # define EXT4_BLOCK_SIZE(s)             (EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
 240 #endif
 241 #define EXT4_ADDR_PER_BLOCK(s)          (EXT4_BLOCK_SIZE(s) / sizeof(__u32))
 242 #define EXT4_CLUSTER_SIZE(s)            (EXT4_BLOCK_SIZE(s) << \
 243                                          EXT4_SB(s)->s_cluster_bits)
 244 #ifdef __KERNEL__
 245 # define EXT4_BLOCK_SIZE_BITS(s)        ((s)->s_blocksize_bits)
 246 # define EXT4_CLUSTER_BITS(s)           (EXT4_SB(s)->s_cluster_bits)
 247 #else
 248 # define EXT4_BLOCK_SIZE_BITS(s)        ((s)->s_log_block_size + 10)
 249 #endif
 250 #ifdef __KERNEL__
 251 #define EXT4_ADDR_PER_BLOCK_BITS(s)     (EXT4_SB(s)->s_addr_per_block_bits)
 252 #define EXT4_INODE_SIZE(s)              (EXT4_SB(s)->s_inode_size)
 253 #define EXT4_FIRST_INO(s)               (EXT4_SB(s)->s_first_ino)
 254 #else
 255 #define EXT4_INODE_SIZE(s)      (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
 256                                  EXT4_GOOD_OLD_INODE_SIZE : \
 257                                  (s)->s_inode_size)
 258 #define EXT4_FIRST_INO(s)       (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
 259                                  EXT4_GOOD_OLD_FIRST_INO : \
 260                                  (s)->s_first_ino)
 261 #endif
 262 #define EXT4_BLOCK_ALIGN(size, blkbits)         ALIGN((size), (1 << (blkbits)))
 263
 264 /* Translate a block number to a cluster number */
 265 #define EXT4_B2C(sbi, blk)      ((blk) >> (sbi)->s_cluster_bits)
 266 /* Translate a cluster number to a block number */
 267 #define EXT4_C2B(sbi, cluster)  ((cluster) << (sbi)->s_cluster_bits)
 268 /* Translate # of blks to # of clusters */
 269 #define EXT4_NUM_B2C(sbi, blks) (((blks) + (sbi)->s_cluster_ratio - 1) >> \
 270                                  (sbi)->s_cluster_bits)
 271
 272 /*
 273  * Structure of a blocks group descriptor
 274  */
 275 struct ext4_group_desc
 276 {
 277         __le32  bg_block_bitmap_lo;     /* Blocks bitmap block */
 278         __le32  bg_inode_bitmap_lo;     /* Inodes bitmap block */
 279         __le32  bg_inode_table_lo;      /* Inodes table block */
 280         __le16  bg_free_blocks_count_lo;/* Free blocks count */
 281         __le16  bg_free_inodes_count_lo;/* Free inodes count */
 282         __le16  bg_used_dirs_count_lo;  /* Directories count */
 283         __le16  bg_flags;               /* EXT4_BG_flags (INODE_UNINIT, etc) */
 284         __le32  bg_exclude_bitmap_lo;   /* Exclude bitmap for snapshots */
 285         __le16  bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bbitmap) LE */
 286         __le16  bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+ibitmap) LE */
 287         __le16  bg_itable_unused_lo;    /* Unused inodes count */
 288         __le16  bg_checksum;            /* crc16(sb_uuid+group+desc) */
 289         __le32  bg_block_bitmap_hi;     /* Blocks bitmap block MSB */
 290         __le32  bg_inode_bitmap_hi;     /* Inodes bitmap block MSB */
 291         __le32  bg_inode_table_hi;      /* Inodes table block MSB */
 292         __le16  bg_free_blocks_count_hi;/* Free blocks count MSB */
 293         __le16  bg_free_inodes_count_hi;/* Free inodes count MSB */
 294         __le16  bg_used_dirs_count_hi;  /* Directories count MSB */
 295         __le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
 296         __le32  bg_exclude_bitmap_hi;   /* Exclude bitmap block MSB */
 297         __le16  bg_block_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bbitmap) BE */
 298         __le16  bg_inode_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+ibitmap) BE */
 299         __u32   bg_reserved;
 300 };
 301
 302 #define EXT4_BG_INODE_BITMAP_CSUM_HI_END        \
 303         (offsetof(struct ext4_group_desc, bg_inode_bitmap_csum_hi) + \
 304          sizeof(__le16))
 305 #define EXT4_BG_BLOCK_BITMAP_CSUM_HI_END        \
 306         (offsetof(struct ext4_group_desc, bg_block_bitmap_csum_hi) + \
 307          sizeof(__le16))
 308
 309 /*
 310  * Structure of a flex block group info
 311  */
 312
 313 struct flex_groups {
 314         atomic64_t      free_clusters;
 315         atomic_t        free_inodes;
 316         atomic_t        used_dirs;
 317 };
 318
 319 #define EXT4_BG_INODE_UNINIT    0x0001 /* Inode table/bitmap not in use */
 320 #define EXT4_BG_BLOCK_UNINIT    0x0002 /* Block bitmap not in use */
 321 #define EXT4_BG_INODE_ZEROED    0x0004 /* On-disk itable initialized to zero */
 322
 323 /*
 324  * Macro-instructions used to manage group descriptors
 325  */
 326 #define EXT4_MIN_DESC_SIZE              32
 327 #define EXT4_MIN_DESC_SIZE_64BIT        64
 328 #define EXT4_MAX_DESC_SIZE              EXT4_MIN_BLOCK_SIZE
 329 #define EXT4_DESC_SIZE(s)               (EXT4_SB(s)->s_desc_size)
 330 #ifdef __KERNEL__
 331 # define EXT4_BLOCKS_PER_GROUP(s)       (EXT4_SB(s)->s_blocks_per_group)
 332 # define EXT4_CLUSTERS_PER_GROUP(s)     (EXT4_SB(s)->s_clusters_per_group)
 333 # define EXT4_DESC_PER_BLOCK(s)         (EXT4_SB(s)->s_desc_per_block)
 334 # define EXT4_INODES_PER_GROUP(s)       (EXT4_SB(s)->s_inodes_per_group)
 335 # define EXT4_DESC_PER_BLOCK_BITS(s)    (EXT4_SB(s)->s_desc_per_block_bits)
 336 #else
 337 # define EXT4_BLOCKS_PER_GROUP(s)       ((s)->s_blocks_per_group)
 338 # define EXT4_DESC_PER_BLOCK(s)         (EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
 339 # define EXT4_INODES_PER_GROUP(s)       ((s)->s_inodes_per_group)
 340 #endif
 341
 342 /*
 343  * Constants relative to the data blocks
 344  */
 345 #define EXT4_NDIR_BLOCKS                12
 346 #define EXT4_IND_BLOCK                  EXT4_NDIR_BLOCKS
 347 #define EXT4_DIND_BLOCK                 (EXT4_IND_BLOCK + 1)
 348 #define EXT4_TIND_BLOCK                 (EXT4_DIND_BLOCK + 1)
 349 #define EXT4_N_BLOCKS                   (EXT4_TIND_BLOCK + 1)
 350
 351 /*
 352  * Inode flags
 353  */
 354 #define EXT4_SECRM_FL                   0x00000001 /* Secure deletion */
 355 #define EXT4_UNRM_FL                    0x00000002 /* Undelete */
 356 #define EXT4_COMPR_FL                   0x00000004 /* Compress file */
 357 #define EXT4_SYNC_FL                    0x00000008 /* Synchronous updates */
 358 #define EXT4_IMMUTABLE_FL               0x00000010 /* Immutable file */
 359 #define EXT4_APPEND_FL                  0x00000020 /* writes to file may only append */
 360 #define EXT4_NODUMP_FL                  0x00000040 /* do not dump file */
 361 #define EXT4_NOATIME_FL                 0x00000080 /* do not update atime */
 362 /* Reserved for compression usage... */
 363 #define EXT4_DIRTY_FL                   0x00000100
 364 #define EXT4_COMPRBLK_FL                0x00000200 /* One or more compressed clusters */
 365 #define EXT4_NOCOMPR_FL                 0x00000400 /* Don't compress */
 366 #define EXT4_ECOMPR_FL                  0x00000800 /* Compression error */
 367 /* End compression flags --- maybe not all used */
 368 #define EXT4_INDEX_FL                   0x00001000 /* hash-indexed directory */
 369 #define EXT4_IMAGIC_FL                  0x00002000 /* AFS directory */
 370 #define EXT4_JOURNAL_DATA_FL            0x00004000 /* file data should be journaled */
 371 #define EXT4_NOTAIL_FL                  0x00008000 /* file tail should not be merged */
 372 #define EXT4_DIRSYNC_FL                 0x00010000 /* dirsync behaviour (directories only) */
 373 #define EXT4_TOPDIR_FL                  0x00020000 /* Top of directory hierarchies*/
 374 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
 375 #define EXT4_EXTENTS_FL                 0x00080000 /* Inode uses extents */
 376 #define EXT4_EA_INODE_FL                0x00200000 /* Inode used for large EA */
 377 #define EXT4_EOFBLOCKS_FL               0x00400000 /* Blocks allocated beyond EOF */
 378 #define EXT4_INLINE_DATA_FL             0x10000000 /* Inode has inline data. */
 379 #define EXT4_RESERVED_FL                0x80000000 /* reserved for ext4 lib */
 380
 381 #define EXT4_FL_USER_VISIBLE            0x004BDFFF /* User visible flags */
 382 #define EXT4_FL_USER_MODIFIABLE         0x004380FF /* User modifiable flags */
 383
 384 /* Flags that should be inherited by new inodes from their parent. */
 385 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
 386                            EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
 387                            EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
 388                            EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
 389
 390 /* Flags that are appropriate for regular files (all but dir-specific ones). */
 391 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
 392
 393 /* Flags that are appropriate for non-directories/regular files. */
 394 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
 395
 396 /* Mask out flags that are inappropriate for the given type of inode. */
 397 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
 398 {
 399         if (S_ISDIR(mode))
 400                 return flags;
 401         else if (S_ISREG(mode))
 402                 return flags & EXT4_REG_FLMASK;
 403         else
 404                 return flags & EXT4_OTHER_FLMASK;
 405 }
 406
 407 /*
 408  * Inode flags used for atomic set/get
 409  */
 410 enum {
 411         EXT4_INODE_SECRM        = 0,    /* Secure deletion */
 412         EXT4_INODE_UNRM         = 1,    /* Undelete */
 413         EXT4_INODE_COMPR        = 2,    /* Compress file */
 414         EXT4_INODE_SYNC         = 3,    /* Synchronous updates */
 415         EXT4_INODE_IMMUTABLE    = 4,    /* Immutable file */
 416         EXT4_INODE_APPEND       = 5,    /* writes to file may only append */
 417         EXT4_INODE_NODUMP       = 6,    /* do not dump file */
 418         EXT4_INODE_NOATIME      = 7,    /* do not update atime */
 419 /* Reserved for compression usage... */
 420         EXT4_INODE_DIRTY        = 8,
 421         EXT4_INODE_COMPRBLK     = 9,    /* One or more compressed clusters */
 422         EXT4_INODE_NOCOMPR      = 10,   /* Don't compress */
 423         EXT4_INODE_ECOMPR       = 11,   /* Compression error */
 424 /* End compression flags --- maybe not all used */
 425         EXT4_INODE_INDEX        = 12,   /* hash-indexed directory */
 426         EXT4_INODE_IMAGIC       = 13,   /* AFS directory */
 427         EXT4_INODE_JOURNAL_DATA = 14,   /* file data should be journaled */
 428         EXT4_INODE_NOTAIL       = 15,   /* file tail should not be merged */
 429         EXT4_INODE_DIRSYNC      = 16,   /* dirsync behaviour (directories only) */
 430         EXT4_INODE_TOPDIR       = 17,   /* Top of directory hierarchies*/
 431         EXT4_INODE_HUGE_FILE    = 18,   /* Set to each huge file */
 432         EXT4_INODE_EXTENTS      = 19,   /* Inode uses extents */
 433         EXT4_INODE_EA_INODE     = 21,   /* Inode used for large EA */
 434         EXT4_INODE_EOFBLOCKS    = 22,   /* Blocks allocated beyond EOF */
 435         EXT4_INODE_INLINE_DATA  = 28,   /* Data in inode. */
 436         EXT4_INODE_RESERVED     = 31,   /* reserved for ext4 lib */
 437 };
 438
 439 /*
 440  * Since it's pretty easy to mix up bit numbers and hex values, we use a
 441  * build-time check to make sure that EXT4_XXX_FL is consistent with respect to
 442  * EXT4_INODE_XXX. If all is well, the macros will be dropped, so, it won't cost
 443  * any extra space in the compiled kernel image, otherwise, the build will fail.
 444  * It's important that these values are the same, since we are using
 445  * EXT4_INODE_XXX to test for flag values, but EXT4_XXX_FL must be consistent
 446  * with the values of FS_XXX_FL defined in include/linux/fs.h and the on-disk
 447  * values found in ext2, ext3 and ext4 filesystems, and of course the values
 448  * defined in e2fsprogs.
 449  *
 450  * It's not paranoia if the Murphy's Law really *is* out to get you.  :-)
 451  */
 452 #define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1 << EXT4_INODE_##FLAG))
 453 #define CHECK_FLAG_VALUE(FLAG) BUILD_BUG_ON(!TEST_FLAG_VALUE(FLAG))
 454
 455 static inline void ext4_check_flag_values(void)
 456 {
 457         CHECK_FLAG_VALUE(SECRM);
 458         CHECK_FLAG_VALUE(UNRM);
 459         CHECK_FLAG_VALUE(COMPR);
 460         CHECK_FLAG_VALUE(SYNC);
 461         CHECK_FLAG_VALUE(IMMUTABLE);
 462         CHECK_FLAG_VALUE(APPEND);
 463         CHECK_FLAG_VALUE(NODUMP);
 464         CHECK_FLAG_VALUE(NOATIME);
 465         CHECK_FLAG_VALUE(DIRTY);
 466         CHECK_FLAG_VALUE(COMPRBLK);
 467         CHECK_FLAG_VALUE(NOCOMPR);
 468         CHECK_FLAG_VALUE(ECOMPR);
 469         CHECK_FLAG_VALUE(INDEX);
 470         CHECK_FLAG_VALUE(IMAGIC);
 471         CHECK_FLAG_VALUE(JOURNAL_DATA);
 472         CHECK_FLAG_VALUE(NOTAIL);
 473         CHECK_FLAG_VALUE(DIRSYNC);
 474         CHECK_FLAG_VALUE(TOPDIR);
 475         CHECK_FLAG_VALUE(HUGE_FILE);
 476         CHECK_FLAG_VALUE(EXTENTS);
 477         CHECK_FLAG_VALUE(EA_INODE);
 478         CHECK_FLAG_VALUE(EOFBLOCKS);
 479         CHECK_FLAG_VALUE(INLINE_DATA);
 480         CHECK_FLAG_VALUE(RESERVED);
 481 }
 482
 483 /* Used to pass group descriptor data when online resize is done */
 484 struct ext4_new_group_input {
 485         __u32 group;            /* Group number for this data */
 486         __u64 block_bitmap;     /* Absolute block number of block bitmap */
 487         __u64 inode_bitmap;     /* Absolute block number of inode bitmap */
 488         __u64 inode_table;      /* Absolute block number of inode table start */
 489         __u32 blocks_count;     /* Total number of blocks in this group */
 490         __u16 reserved_blocks;  /* Number of reserved blocks in this group */
 491         __u16 unused;
 492 };
 493
 494 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
 495 struct compat_ext4_new_group_input {
 496         u32 group;
 497         compat_u64 block_bitmap;
 498         compat_u64 inode_bitmap;
 499         compat_u64 inode_table;
 500         u32 blocks_count;
 501         u16 reserved_blocks;
 502         u16 unused;
 503 };
 504 #endif
 505
 506 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
 507 struct ext4_new_group_data {
 508         __u32 group;
 509         __u64 block_bitmap;
 510         __u64 inode_bitmap;
 511         __u64 inode_table;
 512         __u32 blocks_count;
 513         __u16 reserved_blocks;
 514         __u16 unused;
 515         __u32 free_blocks_count;
 516 };
 517
 518 /* Indexes used to index group tables in ext4_new_group_data */
 519 enum {
 520         BLOCK_BITMAP = 0,       /* block bitmap */
 521         INODE_BITMAP,           /* inode bitmap */
 522         INODE_TABLE,            /* inode tables */
 523         GROUP_TABLE_COUNT,
 524 };
 525
 526 /*
 527  * Flags used by ext4_map_blocks()
 528  */
 529         /* Allocate any needed blocks and/or convert an unitialized
 530            extent to be an initialized ext4 */
 531 #define EXT4_GET_BLOCKS_CREATE                  0x0001
 532         /* Request the creation of an unitialized extent */
 533 #define EXT4_GET_BLOCKS_UNINIT_EXT              0x0002
 534 #define EXT4_GET_BLOCKS_CREATE_UNINIT_EXT       (EXT4_GET_BLOCKS_UNINIT_EXT|\
 535                                                  EXT4_GET_BLOCKS_CREATE)
 536         /* Caller is from the delayed allocation writeout path
 537          * finally doing the actual allocation of delayed blocks */
 538 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE        0x0004
 539         /* caller is from the direct IO path, request to creation of an
 540         unitialized extents if not allocated, split the uninitialized
 541         extent if blocks has been preallocated already*/
 542 #define EXT4_GET_BLOCKS_PRE_IO                  0x0008
 543 #define EXT4_GET_BLOCKS_CONVERT                 0x0010
 544 #define EXT4_GET_BLOCKS_IO_CREATE_EXT           (EXT4_GET_BLOCKS_PRE_IO|\
 545                                          EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
 546         /* Convert extent to initialized after IO complete */
 547 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT          (EXT4_GET_BLOCKS_CONVERT|\
 548                                          EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
 549         /* Eventual metadata allocation (due to growing extent tree)
 550          * should not fail, so try to use reserved blocks for that.*/
 551 #define EXT4_GET_BLOCKS_METADATA_NOFAIL         0x0020
 552         /* Don't normalize allocation size (used for fallocate) */
 553 #define EXT4_GET_BLOCKS_NO_NORMALIZE            0x0040
 554         /* Request will not result in inode size update (user for fallocate) */
 555 #define EXT4_GET_BLOCKS_KEEP_SIZE               0x0080
 556         /* Do not take i_data_sem locking in ext4_map_blocks */
 557 #define EXT4_GET_BLOCKS_NO_LOCK                 0x0100
 558         /* Do not put hole in extent cache */
 559 #define EXT4_GET_BLOCKS_NO_PUT_HOLE             0x0200
 560
 561 /*
 562  * The bit position of these flags must not overlap with any of the
 563  * EXT4_GET_BLOCKS_*.  They are used by ext4_ext_find_extent(),
 564  * read_extent_tree_block(), ext4_split_extent_at(),
 565  * ext4_ext_insert_extent(), and ext4_ext_create_new_leaf().
 566  * EXT4_EX_NOCACHE is used to indicate that the we shouldn't be
 567  * caching the extents when reading from the extent tree while a
 568  * truncate or punch hole operation is in progress.
 569  */
 570 #define EXT4_EX_NOCACHE                         0x0400
 571 #define EXT4_EX_FORCE_CACHE                     0x0800
 572
 573 /*
 574  * Flags used by ext4_free_blocks
 575  */
 576 #define EXT4_FREE_BLOCKS_METADATA       0x0001
 577 #define EXT4_FREE_BLOCKS_FORGET         0x0002
 578 #define EXT4_FREE_BLOCKS_VALIDATED      0x0004
 579 #define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE 0x0008
 580 #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER   0x0010
 581 #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER    0x0020
 582 #define EXT4_FREE_BLOCKS_RESERVE                0x0040
 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 #define EXT4_IOC_PRECACHE_EXTENTS       _IO('f', 18)
 605
 606 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
 607 /*
 608  * ioctl commands in 32 bit emulation
 609  */
 610 #define EXT4_IOC32_GETFLAGS             FS_IOC32_GETFLAGS
 611 #define EXT4_IOC32_SETFLAGS             FS_IOC32_SETFLAGS
 612 #define EXT4_IOC32_GETVERSION           _IOR('f', 3, int)
 613 #define EXT4_IOC32_SETVERSION           _IOW('f', 4, int)
 614 #define EXT4_IOC32_GETRSVSZ             _IOR('f', 5, int)
 615 #define EXT4_IOC32_SETRSVSZ             _IOW('f', 6, int)
 616 #define EXT4_IOC32_GROUP_EXTEND         _IOW('f', 7, unsigned int)
 617 #define EXT4_IOC32_GROUP_ADD            _IOW('f', 8, struct compat_ext4_new_group_input)
 618 #define EXT4_IOC32_GETVERSION_OLD       FS_IOC32_GETVERSION
 619 #define EXT4_IOC32_SETVERSION_OLD       FS_IOC32_SETVERSION
 620 #endif
 621
 622 /* Max physical block we can address w/o extents */
 623 #define EXT4_MAX_BLOCK_FILE_PHYS        0xFFFFFFFF
 624
 625 /*
 626  * Structure of an inode on the disk
 627  */
 628 struct ext4_inode {
 629         __le16  i_mode;         /* File mode */
 630         __le16  i_uid;          /* Low 16 bits of Owner Uid */
 631         __le32  i_size_lo;      /* Size in bytes */
 632         __le32  i_atime;        /* Access time */
 633         __le32  i_ctime;        /* Inode Change time */
 634         __le32  i_mtime;        /* Modification time */
 635         __le32  i_dtime;        /* Deletion Time */
 636         __le16  i_gid;          /* Low 16 bits of Group Id */
 637         __le16  i_links_count;  /* Links count */
 638         __le32  i_blocks_lo;    /* Blocks count */
 639         __le32  i_flags;        /* File flags */
 640         union {
 641                 struct {
 642                         __le32  l_i_version;
 643                 } linux1;
 644                 struct {
 645                         __u32  h_i_translator;
 646                 } hurd1;
 647                 struct {
 648                         __u32  m_i_reserved1;
 649                 } masix1;
 650         } osd1;                         /* OS dependent 1 */
 651         __le32  i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
 652         __le32  i_generation;   /* File version (for NFS) */
 653         __le32  i_file_acl_lo;  /* File ACL */
 654         __le32  i_size_high;
 655         __le32  i_obso_faddr;   /* Obsoleted fragment address */
 656         union {
 657                 struct {
 658                         __le16  l_i_blocks_high; /* were l_i_reserved1 */
 659                         __le16  l_i_file_acl_high;
 660                         __le16  l_i_uid_high;   /* these 2 fields */
 661                         __le16  l_i_gid_high;   /* were reserved2[0] */
 662                         __le16  l_i_checksum_lo;/* crc32c(uuid+inum+inode) LE */
 663                         __le16  l_i_reserved;
 664                 } linux2;
 665                 struct {
 666                         __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
 667                         __u16   h_i_mode_high;
 668                         __u16   h_i_uid_high;
 669                         __u16   h_i_gid_high;
 670                         __u32   h_i_author;
 671                 } hurd2;
 672                 struct {
 673                         __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
 674                         __le16  m_i_file_acl_high;
 675                         __u32   m_i_reserved2[2];
 676                 } masix2;
 677         } osd2;                         /* OS dependent 2 */
 678         __le16  i_extra_isize;
 679         __le16  i_checksum_hi;  /* crc32c(uuid+inum+inode) BE */
 680         __le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
 681         __le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
 682         __le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
 683         __le32  i_crtime;       /* File Creation time */
 684         __le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
 685         __le32  i_version_hi;   /* high 32 bits for 64-bit version */
 686 };
 687
 688 struct move_extent {
 689         __u32 reserved;         /* should be zero */
 690         __u32 donor_fd;         /* donor file descriptor */
 691         __u64 orig_start;       /* logical start offset in block for orig */
 692         __u64 donor_start;      /* logical start offset in block for donor */
 693         __u64 len;              /* block length to be moved */
 694         __u64 moved_len;        /* moved block length */
 695 };
 696
 697 #define EXT4_EPOCH_BITS 2
 698 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
 699 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
 700
 701 /*
 702  * Extended fields will fit into an inode if the filesystem was formatted
 703  * with large inodes (-I 256 or larger) and there are not currently any EAs
 704  * consuming all of the available space. For new inodes we always reserve
 705  * enough space for the kernel's known extended fields, but for inodes
 706  * created with an old kernel this might not have been the case. None of
 707  * the extended inode fields is critical for correct filesystem operation.
 708  * This macro checks if a certain field fits in the inode. Note that
 709  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
 710  */
 711 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)   \
 712         ((offsetof(typeof(*ext4_inode), field) +        \
 713           sizeof((ext4_inode)->field))                  \
 714         <= (EXT4_GOOD_OLD_INODE_SIZE +                  \
 715             (einode)->i_extra_isize))                   \
 716
 717 static inline __le32 ext4_encode_extra_time(struct timespec *time)
 718 {
 719        return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
 720                            (time->tv_sec >> 32) & EXT4_EPOCH_MASK : 0) |
 721                           ((time->tv_nsec << EXT4_EPOCH_BITS) & EXT4_NSEC_MASK));
 722 }
 723
 724 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
 725 {
 726        if (sizeof(time->tv_sec) > 4)
 727                time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
 728                                << 32;
 729        time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
 730 }
 731
 732 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)                          \
 733 do {                                                                           \
 734         (raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);               \
 735         if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
 736                 (raw_inode)->xtime ## _extra =                                 \
 737                                 ext4_encode_extra_time(&(inode)->xtime);       \
 738 } while (0)
 739
 740 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)                        \
 741 do {                                                                           \
 742         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))                      \
 743                 (raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
 744         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))            \
 745                 (raw_inode)->xtime ## _extra =                                 \
 746                                 ext4_encode_extra_time(&(einode)->xtime);      \
 747 } while (0)
 748
 749 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)                          \
 750 do {                                                                           \
 751         (inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
 752         if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
 753                 ext4_decode_extra_time(&(inode)->xtime,                        \
 754                                        raw_inode->xtime ## _extra);            \
 755         else                                                                   \
 756                 (inode)->xtime.tv_nsec = 0;                                    \
 757 } while (0)
 758
 759 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)                        \
 760 do {                                                                           \
 761         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))                      \
 762                 (einode)->xtime.tv_sec =                                       \
 763                         (signed)le32_to_cpu((raw_inode)->xtime);               \
 764         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))            \
 765                 ext4_decode_extra_time(&(einode)->xtime,                       \
 766                                        raw_inode->xtime ## _extra);            \
 767         else                                                                   \
 768                 (einode)->xtime.tv_nsec = 0;                                   \
 769 } while (0)
 770
 771 #define i_disk_version osd1.linux1.l_i_version
 772
 773 #if defined(__KERNEL__) || defined(__linux__)
 774 #define i_reserved1     osd1.linux1.l_i_reserved1
 775 #define i_file_acl_high osd2.linux2.l_i_file_acl_high
 776 #define i_blocks_high   osd2.linux2.l_i_blocks_high
 777 #define i_uid_low       i_uid
 778 #define i_gid_low       i_gid
 779 #define i_uid_high      osd2.linux2.l_i_uid_high
 780 #define i_gid_high      osd2.linux2.l_i_gid_high
 781 #define i_checksum_lo   osd2.linux2.l_i_checksum_lo
 782
 783 #elif defined(__GNU__)
 784
 785 #define i_translator    osd1.hurd1.h_i_translator
 786 #define i_uid_high      osd2.hurd2.h_i_uid_high
 787 #define i_gid_high      osd2.hurd2.h_i_gid_high
 788 #define i_author        osd2.hurd2.h_i_author
 789
 790 #elif defined(__masix__)
 791
 792 #define i_reserved1     osd1.masix1.m_i_reserved1
 793 #define i_file_acl_high osd2.masix2.m_i_file_acl_high
 794 #define i_reserved2     osd2.masix2.m_i_reserved2
 795
 796 #endif /* defined(__KERNEL__) || defined(__linux__) */
 797
 798 #include "extents_status.h"
 799
 800 /*
 801  * fourth extended file system inode data in memory
 802  */
 803 struct ext4_inode_info {
 804         __le32  i_data[15];     /* unconverted */
 805         __u32   i_dtime;
 806         ext4_fsblk_t    i_file_acl;
 807
 808         /*
 809          * i_block_group is the number of the block group which contains
 810          * this file's inode.  Constant across the lifetime of the inode,
 811          * it is ued for making block allocation decisions - we try to
 812          * place a file's data blocks near its inode block, and new inodes
 813          * near to their parent directory's inode.
 814          */
 815         ext4_group_t    i_block_group;
 816         ext4_lblk_t     i_dir_start_lookup;
 817 #if (BITS_PER_LONG < 64)
 818         unsigned long   i_state_flags;          /* Dynamic state flags */
 819 #endif
 820         unsigned long   i_flags;
 821
 822         /*
 823          * Extended attributes can be read independently of the main file
 824          * data. Taking i_mutex even when reading would cause contention
 825          * between readers of EAs and writers of regular file data, so
 826          * instead we synchronize on xattr_sem when reading or changing
 827          * EAs.
 828          */
 829         struct rw_semaphore xattr_sem;
 830
 831         struct list_head i_orphan;      /* unlinked but open inodes */
 832
 833         /*
 834          * i_disksize keeps track of what the inode size is ON DISK, not
 835          * in memory.  During truncate, i_size is set to the new size by
 836          * the VFS prior to calling ext4_truncate(), but the filesystem won't
 837          * set i_disksize to 0 until the truncate is actually under way.
 838          *
 839          * The intent is that i_disksize always represents the blocks which
 840          * are used by this file.  This allows recovery to restart truncate
 841          * on orphans if we crash during truncate.  We actually write i_disksize
 842          * into the on-disk inode when writing inodes out, instead of i_size.
 843          *
 844          * The only time when i_disksize and i_size may be different is when
 845          * a truncate is in progress.  The only things which change i_disksize
 846          * are ext4_get_block (growth) and ext4_truncate (shrinkth).
 847          */
 848         loff_t  i_disksize;
 849
 850         /*
 851          * i_data_sem is for serialising ext4_truncate() against
 852          * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
 853          * data tree are chopped off during truncate. We can't do that in
 854          * ext4 because whenever we perform intermediate commits during
 855          * truncate, the inode and all the metadata blocks *must* be in a
 856          * consistent state which allows truncation of the orphans to restart
 857          * during recovery.  Hence we must fix the get_block-vs-truncate race
 858          * by other means, so we have i_data_sem.
 859          */
 860         struct rw_semaphore i_data_sem;
 861         struct inode vfs_inode;
 862         struct jbd2_inode *jinode;
 863
 864         /*
 865          * File creation time. Its function is same as that of
 866          * struct timespec i_{a,c,m}time in the generic inode.
 867          */
 868         struct timespec i_crtime;
 869
 870         /* mballoc */
 871         struct list_head i_prealloc_list;
 872         spinlock_t i_prealloc_lock;
 873
 874         /* extents status tree */
 875         struct ext4_es_tree i_es_tree;
 876         rwlock_t i_es_lock;
 877         struct list_head i_es_lru;
 878         unsigned int i_es_lru_nr;       /* protected by i_es_lock */
 879         unsigned long i_touch_when;     /* jiffies of last accessing */
 880
 881         /* ialloc */
 882         ext4_group_t    i_last_alloc_group;
 883
 884         /* allocation reservation info for delalloc */
 885         /* In case of bigalloc, these refer to clusters rather than blocks */
 886         unsigned int i_reserved_data_blocks;
 887         unsigned int i_reserved_meta_blocks;
 888         unsigned int i_allocated_meta_blocks;
 889         ext4_lblk_t i_da_metadata_calc_last_lblock;
 890         int i_da_metadata_calc_len;
 891
 892         /* on-disk additional length */
 893         __u16 i_extra_isize;
 894
 895         /* Indicate the inline data space. */
 896         u16 i_inline_off;
 897         u16 i_inline_size;
 898
 899 #ifdef CONFIG_QUOTA
 900         /* quota space reservation, managed internally by quota code */
 901         qsize_t i_reserved_quota;
 902 #endif
 903
 904         /* Lock protecting lists below */
 905         spinlock_t i_completed_io_lock;
 906         /*
 907          * Completed IOs that need unwritten extents handling and have
 908          * transaction reserved
 909          */
 910         struct list_head i_rsv_conversion_list;
 911         /*
 912          * Completed IOs that need unwritten extents handling and don't have
 913          * transaction reserved
 914          */
 915         atomic_t i_ioend_count; /* Number of outstanding io_end structs */
 916         atomic_t i_unwritten; /* Nr. of inflight conversions pending */
 917         struct work_struct i_rsv_conversion_work;
 918
 919         spinlock_t i_block_reservation_lock;
 920
 921         /*
 922          * Transactions that contain inode's metadata needed to complete
 923          * fsync and fdatasync, respectively.
 924          */
 925         tid_t i_sync_tid;
 926         tid_t i_datasync_tid;
 927
 928         /* Precomputed uuid+inum+igen checksum for seeding inode checksums */
 929         __u32 i_csum_seed;
 930 };
 931
 932 /*
 933  * File system states
 934  */
 935 #define EXT4_VALID_FS                   0x0001  /* Unmounted cleanly */
 936 #define EXT4_ERROR_FS                   0x0002  /* Errors detected */
 937 #define EXT4_ORPHAN_FS                  0x0004  /* Orphans being recovered */
 938
 939 /*
 940  * Misc. filesystem flags
 941  */
 942 #define EXT2_FLAGS_SIGNED_HASH          0x0001  /* Signed dirhash in use */
 943 #define EXT2_FLAGS_UNSIGNED_HASH        0x0002  /* Unsigned dirhash in use */
 944 #define EXT2_FLAGS_TEST_FILESYS         0x0004  /* to test development code */
 945
 946 /*
 947  * Mount flags set via mount options or defaults
 948  */
 949 #define EXT4_MOUNT_GRPID                0x00004 /* Create files with directory's group */
 950 #define EXT4_MOUNT_DEBUG                0x00008 /* Some debugging messages */
 951 #define EXT4_MOUNT_ERRORS_CONT          0x00010 /* Continue on errors */
 952 #define EXT4_MOUNT_ERRORS_RO            0x00020 /* Remount fs ro on errors */
 953 #define EXT4_MOUNT_ERRORS_PANIC         0x00040 /* Panic on errors */
 954 #define EXT4_MOUNT_ERRORS_MASK          0x00070
 955 #define EXT4_MOUNT_MINIX_DF             0x00080 /* Mimics the Minix statfs */
 956 #define EXT4_MOUNT_NOLOAD               0x00100 /* Don't use existing journal*/
 957 #define EXT4_MOUNT_DATA_FLAGS           0x00C00 /* Mode for data writes: */
 958 #define EXT4_MOUNT_JOURNAL_DATA         0x00400 /* Write data to journal */
 959 #define EXT4_MOUNT_ORDERED_DATA         0x00800 /* Flush data before commit */
 960 #define EXT4_MOUNT_WRITEBACK_DATA       0x00C00 /* No data ordering */
 961 #define EXT4_MOUNT_UPDATE_JOURNAL       0x01000 /* Update the journal format */
 962 #define EXT4_MOUNT_NO_UID32             0x02000  /* Disable 32-bit UIDs */
 963 #define EXT4_MOUNT_XATTR_USER           0x04000 /* Extended user attributes */
 964 #define EXT4_MOUNT_POSIX_ACL            0x08000 /* POSIX Access Control Lists */
 965 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC     0x10000 /* No auto delalloc mapping */
 966 #define EXT4_MOUNT_BARRIER              0x20000 /* Use block barriers */
 967 #define EXT4_MOUNT_QUOTA                0x80000 /* Some quota option set */
 968 #define EXT4_MOUNT_USRQUOTA             0x100000 /* "old" user quota */
 969 #define EXT4_MOUNT_GRPQUOTA             0x200000 /* "old" group quota */
 970 #define EXT4_MOUNT_DIOREAD_NOLOCK       0x400000 /* Enable support for dio read nolocking */
 971 #define EXT4_MOUNT_JOURNAL_CHECKSUM     0x800000 /* Journal checksums */
 972 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT 0x1000000 /* Journal Async Commit */
 973 #define EXT4_MOUNT_DELALLOC             0x8000000 /* Delalloc support */
 974 #define EXT4_MOUNT_DATA_ERR_ABORT       0x10000000 /* Abort on file data write */
 975 #define EXT4_MOUNT_BLOCK_VALIDITY       0x20000000 /* Block validity checking */
 976 #define EXT4_MOUNT_DISCARD              0x40000000 /* Issue DISCARD requests */
 977 #define EXT4_MOUNT_INIT_INODE_TABLE     0x80000000 /* Initialize uninitialized itables */
 978
 979 /*
 980  * Mount flags set either automatically (could not be set by mount option)
 981  * based on per file system feature or property or in special cases such as
 982  * distinguishing between explicit mount option definition and default.
 983  */
 984 #define EXT4_MOUNT2_EXPLICIT_DELALLOC   0x00000001 /* User explicitly
 985                                                       specified delalloc */
 986 #define EXT4_MOUNT2_STD_GROUP_SIZE      0x00000002 /* We have standard group
 987                                                       size of blocksize * 8
 988                                                       blocks */
 989
 990 #define clear_opt(sb, opt)              EXT4_SB(sb)->s_mount_opt &= \
 991                                                 ~EXT4_MOUNT_##opt
 992 #define set_opt(sb, opt)                EXT4_SB(sb)->s_mount_opt |= \
 993                                                 EXT4_MOUNT_##opt
 994 #define test_opt(sb, opt)               (EXT4_SB(sb)->s_mount_opt & \
 995                                          EXT4_MOUNT_##opt)
 996
 997 #define clear_opt2(sb, opt)             EXT4_SB(sb)->s_mount_opt2 &= \
 998                                                 ~EXT4_MOUNT2_##opt
 999 #define set_opt2(sb, opt)               EXT4_SB(sb)->s_mount_opt2 |= \
1000                                                 EXT4_MOUNT2_##opt
1001 #define test_opt2(sb, opt)              (EXT4_SB(sb)->s_mount_opt2 & \
1002                                          EXT4_MOUNT2_##opt)
1003
1004 #define ext4_test_and_set_bit           __test_and_set_bit_le
1005 #define ext4_set_bit                    __set_bit_le
1006 #define ext4_set_bit_atomic             ext2_set_bit_atomic
1007 #define ext4_test_and_clear_bit         __test_and_clear_bit_le
1008 #define ext4_clear_bit                  __clear_bit_le
1009 #define ext4_clear_bit_atomic           ext2_clear_bit_atomic
1010 #define ext4_test_bit                   test_bit_le
1011 #define ext4_find_next_zero_bit         find_next_zero_bit_le
1012 #define ext4_find_next_bit              find_next_bit_le
1013
1014 extern void ext4_set_bits(void *bm, int cur, int len);
1015
1016 /*
1017  * Maximal mount counts between two filesystem checks
1018  */
1019 #define EXT4_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
1020 #define EXT4_DFL_CHECKINTERVAL          0       /* Don't use interval check */
1021
1022 /*
1023  * Behaviour when detecting errors
1024  */
1025 #define EXT4_ERRORS_CONTINUE            1       /* Continue execution */
1026 #define EXT4_ERRORS_RO                  2       /* Remount fs read-only */
1027 #define EXT4_ERRORS_PANIC               3       /* Panic */
1028 #define EXT4_ERRORS_DEFAULT             EXT4_ERRORS_CONTINUE
1029
1030 /* Metadata checksum algorithm codes */
1031 #define EXT4_CRC32C_CHKSUM              1
1032
1033 /*
1034  * Structure of the super block
1035  */
1036 struct ext4_super_block {
1037 /*00*/  __le32  s_inodes_count;         /* Inodes count */
1038         __le32  s_blocks_count_lo;      /* Blocks count */
1039         __le32  s_r_blocks_count_lo;    /* Reserved blocks count */
1040         __le32  s_free_blocks_count_lo; /* Free blocks count */
1041 /*10*/  __le32  s_free_inodes_count;    /* Free inodes count */
1042         __le32  s_first_data_block;     /* First Data Block */
1043         __le32  s_log_block_size;       /* Block size */
1044         __le32  s_log_cluster_size;     /* Allocation cluster size */
1045 /*20*/  __le32  s_blocks_per_group;     /* # Blocks per group */
1046         __le32  s_clusters_per_group;   /* # Clusters per group */
1047         __le32  s_inodes_per_group;     /* # Inodes per group */
1048         __le32  s_mtime;                /* Mount time */
1049 /*30*/  __le32  s_wtime;                /* Write time */
1050         __le16  s_mnt_count;            /* Mount count */
1051         __le16  s_max_mnt_count;        /* Maximal mount count */
1052         __le16  s_magic;                /* Magic signature */
1053         __le16  s_state;                /* File system state */
1054         __le16  s_errors;               /* Behaviour when detecting errors */
1055         __le16  s_minor_rev_level;      /* minor revision level */
1056 /*40*/  __le32  s_lastcheck;            /* time of last check */
1057         __le32  s_checkinterval;        /* max. time between checks */
1058         __le32  s_creator_os;           /* OS */
1059         __le32  s_rev_level;            /* Revision level */
1060 /*50*/  __le16  s_def_resuid;           /* Default uid for reserved blocks */
1061         __le16  s_def_resgid;           /* Default gid for reserved blocks */
1062         /*
1063          * These fields are for EXT4_DYNAMIC_REV superblocks only.
1064          *
1065          * Note: the difference between the compatible feature set and
1066          * the incompatible feature set is that if there is a bit set
1067          * in the incompatible feature set that the kernel doesn't
1068          * know about, it should refuse to mount the filesystem.
1069          *
1070          * e2fsck's requirements are more strict; if it doesn't know
1071          * about a feature in either the compatible or incompatible
1072          * feature set, it must abort and not try to meddle with
1073          * things it doesn't understand...
1074          */
1075         __le32  s_first_ino;            /* First non-reserved inode */
1076         __le16  s_inode_size;           /* size of inode structure */
1077         __le16  s_block_group_nr;       /* block group # of this superblock */
1078         __le32  s_feature_compat;       /* compatible feature set */
1079 /*60*/  __le32  s_feature_incompat;     /* incompatible feature set */
1080         __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
1081 /*68*/  __u8    s_uuid[16];             /* 128-bit uuid for volume */
1082 /*78*/  char    s_volume_name[16];      /* volume name */
1083 /*88*/  char    s_last_mounted[64];     /* directory where last mounted */
1084 /*C8*/  __le32  s_algorithm_usage_bitmap; /* For compression */
1085         /*
1086          * Performance hints.  Directory preallocation should only
1087          * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
1088          */
1089         __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
1090         __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
1091         __le16  s_reserved_gdt_blocks;  /* Per group desc for online growth */
1092         /*
1093          * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
1094          */
1095 /*D0*/  __u8    s_journal_uuid[16];     /* uuid of journal superblock */
1096 /*E0*/  __le32  s_journal_inum;         /* inode number of journal file */
1097         __le32  s_journal_dev;          /* device number of journal file */
1098         __le32  s_last_orphan;          /* start of list of inodes to delete */
1099         __le32  s_hash_seed[4];         /* HTREE hash seed */
1100         __u8    s_def_hash_version;     /* Default hash version to use */
1101         __u8    s_jnl_backup_type;
1102         __le16  s_desc_size;            /* size of group descriptor */
1103 /*100*/ __le32  s_default_mount_opts;
1104         __le32  s_first_meta_bg;        /* First metablock block group */
1105         __le32  s_mkfs_time;            /* When the filesystem was created */
1106         __le32  s_jnl_blocks[17];       /* Backup of the journal inode */
1107         /* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
1108 /*150*/ __le32  s_blocks_count_hi;      /* Blocks count */
1109         __le32  s_r_blocks_count_hi;    /* Reserved blocks count */
1110         __le32  s_free_blocks_count_hi; /* Free blocks count */
1111         __le16  s_min_extra_isize;      /* All inodes have at least # bytes */
1112         __le16  s_want_extra_isize;     /* New inodes should reserve # bytes */
1113         __le32  s_flags;                /* Miscellaneous flags */
1114         __le16  s_raid_stride;          /* RAID stride */
1115         __le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */
1116         __le64  s_mmp_block;            /* Block for multi-mount protection */
1117         __le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1118         __u8    s_log_groups_per_flex;  /* FLEX_BG group size */
1119         __u8    s_checksum_type;        /* metadata checksum algorithm used */
1120         __le16  s_reserved_pad;
1121         __le64  s_kbytes_written;       /* nr of lifetime kilobytes written */
1122         __le32  s_snapshot_inum;        /* Inode number of active snapshot */
1123         __le32  s_snapshot_id;          /* sequential ID of active snapshot */
1124         __le64  s_snapshot_r_blocks_count; /* reserved blocks for active
1125                                               snapshot's future use */
1126         __le32  s_snapshot_list;        /* inode number of the head of the
1127                                            on-disk snapshot list */
1128 #define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
1129         __le32  s_error_count;          /* number of fs errors */
1130         __le32  s_first_error_time;     /* first time an error happened */
1131         __le32  s_first_error_ino;      /* inode involved in first error */
1132         __le64  s_first_error_block;    /* block involved of first error */
1133         __u8    s_first_error_func[32]; /* function where the error happened */
1134         __le32  s_first_error_line;     /* line number where error happened */
1135         __le32  s_last_error_time;      /* most recent time of an error */
1136         __le32  s_last_error_ino;       /* inode involved in last error */
1137         __le32  s_last_error_line;      /* line number where error happened */
1138         __le64  s_last_error_block;     /* block involved of last error */
1139         __u8    s_last_error_func[32];  /* function where the error happened */
1140 #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
1141         __u8    s_mount_opts[64];
1142         __le32  s_usr_quota_inum;       /* inode for tracking user quota */
1143         __le32  s_grp_quota_inum;       /* inode for tracking group quota */
1144         __le32  s_overhead_clusters;    /* overhead blocks/clusters in fs */
1145         __le32  s_reserved[108];        /* Padding to the end of the block */
1146         __le32  s_checksum;             /* crc32c(superblock) */
1147 };
1148
1149 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1150
1151 #ifdef __KERNEL__
1152
1153 /*
1154  * run-time mount flags
1155  */
1156 #define EXT4_MF_MNTDIR_SAMPLED  0x0001
1157 #define EXT4_MF_FS_ABORTED      0x0002  /* Fatal error detected */
1158
1159 /*
1160  * fourth extended-fs super-block data in memory
1161  */
1162 struct ext4_sb_info {
1163         unsigned long s_desc_size;      /* Size of a group descriptor in bytes */
1164         unsigned long s_inodes_per_block;/* Number of inodes per block */
1165         unsigned long s_blocks_per_group;/* Number of blocks in a group */
1166         unsigned long s_clusters_per_group; /* Number of clusters in a group */
1167         unsigned long s_inodes_per_group;/* Number of inodes in a group */
1168         unsigned long s_itb_per_group;  /* Number of inode table blocks per group */
1169         unsigned long s_gdb_count;      /* Number of group descriptor blocks */
1170         unsigned long s_desc_per_block; /* Number of group descriptors per block */
1171         ext4_group_t s_groups_count;    /* Number of groups in the fs */
1172         ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1173         unsigned long s_overhead;  /* # of fs overhead clusters */
1174         unsigned int s_cluster_ratio;   /* Number of blocks per cluster */
1175         unsigned int s_cluster_bits;    /* log2 of s_cluster_ratio */
1176         loff_t s_bitmap_maxbytes;       /* max bytes for bitmap files */
1177         struct buffer_head * s_sbh;     /* Buffer containing the super block */
1178         struct ext4_super_block *s_es;  /* Pointer to the super block in the buffer */
1179         struct buffer_head **s_group_desc;
1180         unsigned int s_mount_opt;
1181         unsigned int s_mount_opt2;
1182         unsigned int s_mount_flags;
1183         unsigned int s_def_mount_opt;
1184         ext4_fsblk_t s_sb_block;
1185         atomic64_t s_resv_clusters;
1186         kuid_t s_resuid;
1187         kgid_t s_resgid;
1188         unsigned short s_mount_state;
1189         unsigned short s_pad;
1190         int s_addr_per_block_bits;
1191         int s_desc_per_block_bits;
1192         int s_inode_size;
1193         int s_first_ino;
1194         unsigned int s_inode_readahead_blks;
1195         unsigned int s_inode_goal;
1196         spinlock_t s_next_gen_lock;
1197         u32 s_next_generation;
1198         u32 s_hash_seed[4];
1199         int s_def_hash_version;
1200         int s_hash_unsigned;    /* 3 if hash should be signed, 0 if not */
1201         struct percpu_counter s_freeclusters_counter;
1202         struct percpu_counter s_freeinodes_counter;
1203         struct percpu_counter s_dirs_counter;
1204         struct percpu_counter s_dirtyclusters_counter;
1205         struct blockgroup_lock *s_blockgroup_lock;
1206         struct proc_dir_entry *s_proc;
1207         struct kobject s_kobj;
1208         struct completion s_kobj_unregister;
1209         struct super_block *s_sb;
1210
1211         /* Journaling */
1212         struct journal_s *s_journal;
1213         struct list_head s_orphan;
1214         struct mutex s_orphan_lock;
1215         unsigned long s_resize_flags;           /* Flags indicating if there
1216                                                    is a resizer */
1217         unsigned long s_commit_interval;
1218         u32 s_max_batch_time;
1219         u32 s_min_batch_time;
1220         struct block_device *journal_bdev;
1221 #ifdef CONFIG_QUOTA
1222         char *s_qf_names[MAXQUOTAS];            /* Names of quota files with journalled quota */
1223         int s_jquota_fmt;                       /* Format of quota to use */
1224 #endif
1225         unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1226         struct rb_root system_blks;
1227
1228 #ifdef EXTENTS_STATS
1229         /* ext4 extents stats */
1230         unsigned long s_ext_min;
1231         unsigned long s_ext_max;
1232         unsigned long s_depth_max;
1233         spinlock_t s_ext_stats_lock;
1234         unsigned long s_ext_blocks;
1235         unsigned long s_ext_extents;
1236 #endif
1237
1238         /* for buddy allocator */
1239         struct ext4_group_info ***s_group_info;
1240         struct inode *s_buddy_cache;
1241         spinlock_t s_md_lock;
1242         unsigned short *s_mb_offsets;
1243         unsigned int *s_mb_maxs;
1244         unsigned int s_group_info_size;
1245
1246         /* tunables */
1247         unsigned long s_stripe;
1248         unsigned int s_mb_stream_request;
1249         unsigned int s_mb_max_to_scan;
1250         unsigned int s_mb_min_to_scan;
1251         unsigned int s_mb_stats;
1252         unsigned int s_mb_order2_reqs;
1253         unsigned int s_mb_group_prealloc;
1254         unsigned int s_max_dir_size_kb;
1255         /* where last allocation was done - for stream allocation */
1256         unsigned long s_mb_last_group;
1257         unsigned long s_mb_last_start;
1258
1259         /* stats for buddy allocator */
1260         atomic_t s_bal_reqs;    /* number of reqs with len > 1 */
1261         atomic_t s_bal_success; /* we found long enough chunks */
1262         atomic_t s_bal_allocated;       /* in blocks */
1263         atomic_t s_bal_ex_scanned;      /* total extents scanned */
1264         atomic_t s_bal_goals;   /* goal hits */
1265         atomic_t s_bal_breaks;  /* too long searches */
1266         atomic_t s_bal_2orders; /* 2^order hits */
1267         spinlock_t s_bal_lock;
1268         unsigned long s_mb_buddies_generated;
1269         unsigned long long s_mb_generation_time;
1270         atomic_t s_mb_lost_chunks;
1271         atomic_t s_mb_preallocated;
1272         atomic_t s_mb_discarded;
1273         atomic_t s_lock_busy;
1274
1275         /* locality groups */
1276         struct ext4_locality_group __percpu *s_locality_groups;
1277
1278         /* for write statistics */
1279         unsigned long s_sectors_written_start;
1280         u64 s_kbytes_written;
1281
1282         /* the size of zero-out chunk */
1283         unsigned int s_extent_max_zeroout_kb;
1284
1285         unsigned int s_log_groups_per_flex;
1286         struct flex_groups *s_flex_groups;
1287         ext4_group_t s_flex_groups_allocated;
1288
1289         /* workqueue for reserved extent conversions (buffered io) */
1290         struct workqueue_struct *rsv_conversion_wq;
1291
1292         /* timer for periodic error stats printing */
1293         struct timer_list s_err_report;
1294
1295         /* Lazy inode table initialization info */
1296         struct ext4_li_request *s_li_request;
1297         /* Wait multiplier for lazy initialization thread */
1298         unsigned int s_li_wait_mult;
1299
1300         /* Kernel thread for multiple mount protection */
1301         struct task_struct *s_mmp_tsk;
1302
1303         /* record the last minlen when FITRIM is called. */
1304         atomic_t s_last_trim_minblks;
1305
1306         /* Reference to checksum algorithm driver via cryptoapi */
1307         struct crypto_shash *s_chksum_driver;
1308
1309         /* Precomputed FS UUID checksum for seeding other checksums */
1310         __u32 s_csum_seed;
1311
1312         /* Reclaim extents from extent status tree */
1313         struct shrinker s_es_shrinker;
1314         struct list_head s_es_lru;
1315         unsigned long s_es_last_sorted;
1316         struct percpu_counter s_extent_cache_cnt;
1317         spinlock_t s_es_lru_lock ____cacheline_aligned_in_smp;
1318
1319         /* Ratelimit ext4 messages. */
1320         struct ratelimit_state s_err_ratelimit_state;
1321         struct ratelimit_state s_warning_ratelimit_state;
1322         struct ratelimit_state s_msg_ratelimit_state;
1323 };
1324
1325 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1326 {
1327         return sb->s_fs_info;
1328 }
1329 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1330 {
1331         return container_of(inode, struct ext4_inode_info, vfs_inode);
1332 }
1333
1334 static inline struct timespec ext4_current_time(struct inode *inode)
1335 {
1336         return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1337                 current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1338 }
1339
1340 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1341 {
1342         return ino == EXT4_ROOT_INO ||
1343                 ino == EXT4_USR_QUOTA_INO ||
1344                 ino == EXT4_GRP_QUOTA_INO ||
1345                 ino == EXT4_BOOT_LOADER_INO ||
1346                 ino == EXT4_JOURNAL_INO ||
1347                 ino == EXT4_RESIZE_INO ||
1348                 (ino >= EXT4_FIRST_INO(sb) &&
1349                  ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1350 }
1351
1352 static inline void ext4_set_io_unwritten_flag(struct inode *inode,
1353                                               struct ext4_io_end *io_end)
1354 {
1355         if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
1356                 io_end->flag |= EXT4_IO_END_UNWRITTEN;
1357                 atomic_inc(&EXT4_I(inode)->i_unwritten);
1358         }
1359 }
1360
1361 static inline ext4_io_end_t *ext4_inode_aio(struct inode *inode)
1362 {
1363         return inode->i_private;
1364 }
1365
1366 static inline void ext4_inode_aio_set(struct inode *inode, ext4_io_end_t *io)
1367 {
1368         inode->i_private = io;
1369 }
1370
1371 /*
1372  * Inode dynamic state flags
1373  */
1374 enum {
1375         EXT4_STATE_JDATA,               /* journaled data exists */
1376         EXT4_STATE_NEW,                 /* inode is newly created */
1377         EXT4_STATE_XATTR,               /* has in-inode xattrs */
1378         EXT4_STATE_NO_EXPAND,           /* No space for expansion */
1379         EXT4_STATE_DA_ALLOC_CLOSE,      /* Alloc DA blks on close */
1380         EXT4_STATE_EXT_MIGRATE,         /* Inode is migrating */
1381         EXT4_STATE_DIO_UNWRITTEN,       /* need convert on dio done*/
1382         EXT4_STATE_NEWENTRY,            /* File just added to dir */
1383         EXT4_STATE_DELALLOC_RESERVED,   /* blks already reserved for delalloc */
1384         EXT4_STATE_DIOREAD_LOCK,        /* Disable support for dio read
1385                                            nolocking */
1386         EXT4_STATE_MAY_INLINE_DATA,     /* may have in-inode data */
1387         EXT4_STATE_ORDERED_MODE,        /* data=ordered mode */
1388         EXT4_STATE_EXT_PRECACHED,       /* extents have been precached */
1389 };
1390
1391 #define EXT4_INODE_BIT_FNS(name, field, offset)                         \
1392 static inline int ext4_test_inode_##name(struct inode *inode, int bit)  \
1393 {                                                                       \
1394         return test_bit(bit + (offset), &EXT4_I(inode)->i_##field);     \
1395 }                                                                       \
1396 static inline void ext4_set_inode_##name(struct inode *inode, int bit)  \
1397 {                                                                       \
1398         set_bit(bit + (offset), &EXT4_I(inode)->i_##field);             \
1399 }                                                                       \
1400 static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1401 {                                                                       \
1402         clear_bit(bit + (offset), &EXT4_I(inode)->i_##field);           \
1403 }
1404
1405 /* Add these declarations here only so that these functions can be
1406  * found by name.  Otherwise, they are very hard to locate. */
1407 static inline int ext4_test_inode_flag(struct inode *inode, int bit);
1408 static inline void ext4_set_inode_flag(struct inode *inode, int bit);
1409 static inline void ext4_clear_inode_flag(struct inode *inode, int bit);
1410 EXT4_INODE_BIT_FNS(flag, flags, 0)
1411
1412 /* Add these declarations here only so that these functions can be
1413  * found by name.  Otherwise, they are very hard to locate. */
1414 static inline int ext4_test_inode_state(struct inode *inode, int bit);
1415 static inline void ext4_set_inode_state(struct inode *inode, int bit);
1416 static inline void ext4_clear_inode_state(struct inode *inode, int bit);
1417 #if (BITS_PER_LONG < 64)
1418 EXT4_INODE_BIT_FNS(state, state_flags, 0)
1419
1420 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1421 {
1422         (ei)->i_state_flags = 0;
1423 }
1424 #else
1425 EXT4_INODE_BIT_FNS(state, flags, 32)
1426
1427 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1428 {
1429         /* We depend on the fact that callers will set i_flags */
1430 }
1431 #endif
1432 #else
1433 /* Assume that user mode programs are passing in an ext4fs superblock, not
1434  * a kernel struct super_block.  This will allow us to call the feature-test
1435  * macros from user land. */
1436 #define EXT4_SB(sb)     (sb)
1437 #endif
1438
1439 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1440
1441 /*
1442  * Codes for operating systems
1443  */
1444 #define EXT4_OS_LINUX           0
1445 #define EXT4_OS_HURD            1
1446 #define EXT4_OS_MASIX           2
1447 #define EXT4_OS_FREEBSD         3
1448 #define EXT4_OS_LITES           4
1449
1450 /*
1451  * Revision levels
1452  */
1453 #define EXT4_GOOD_OLD_REV       0       /* The good old (original) format */
1454 #define EXT4_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
1455
1456 #define EXT4_CURRENT_REV        EXT4_GOOD_OLD_REV
1457 #define EXT4_MAX_SUPP_REV       EXT4_DYNAMIC_REV
1458
1459 #define EXT4_GOOD_OLD_INODE_SIZE 128
1460
1461 /*
1462  * Feature set definitions
1463  */
1464
1465 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)                        \
1466         ((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1467 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
1468         ((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1469 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)                      \
1470         ((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1471 #define EXT4_SET_COMPAT_FEATURE(sb,mask)                        \
1472         EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1473 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)                     \
1474         EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1475 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)                      \
1476         EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1477 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)                      \
1478         EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1479 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
1480         EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1481 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
1482         EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1483
1484 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC        0x0001
1485 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES       0x0002
1486 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL         0x0004
1487 #define EXT4_FEATURE_COMPAT_EXT_ATTR            0x0008
1488 #define EXT4_FEATURE_COMPAT_RESIZE_INODE        0x0010
1489 #define EXT4_FEATURE_COMPAT_DIR_INDEX           0x0020
1490
1491 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
1492 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
1493 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
1494 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1495 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM         0x0010
1496 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK        0x0020
1497 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE      0x0040
1498 #define EXT4_FEATURE_RO_COMPAT_QUOTA            0x0100
1499 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC         0x0200
1500 /*
1501  * METADATA_CSUM also enables group descriptor checksums (GDT_CSUM).  When
1502  * METADATA_CSUM is set, group descriptor checksums use the same algorithm as
1503  * all other data structures' checksums.  However, the METADATA_CSUM and
1504  * GDT_CSUM bits are mutually exclusive.
1505  */
1506 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM    0x0400
1507
1508 #define EXT4_FEATURE_INCOMPAT_COMPRESSION       0x0001
1509 #define EXT4_FEATURE_INCOMPAT_FILETYPE          0x0002
1510 #define EXT4_FEATURE_INCOMPAT_RECOVER           0x0004 /* Needs recovery */
1511 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008 /* Journal device */
1512 #define EXT4_FEATURE_INCOMPAT_META_BG           0x0010
1513 #define EXT4_FEATURE_INCOMPAT_EXTENTS           0x0040 /* extents support */
1514 #define EXT4_FEATURE_INCOMPAT_64BIT             0x0080
1515 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1516 #define EXT4_FEATURE_INCOMPAT_FLEX_BG           0x0200
1517 #define EXT4_FEATURE_INCOMPAT_EA_INODE          0x0400 /* EA in inode */
1518 #define EXT4_FEATURE_INCOMPAT_DIRDATA           0x1000 /* data in dirent */
1519 #define EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM  0x2000 /* use crc32c for bg */
1520 #define EXT4_FEATURE_INCOMPAT_LARGEDIR          0x4000 /* >2GB or 3-lvl htree */
1521 #define EXT4_FEATURE_INCOMPAT_INLINE_DATA       0x8000 /* data in inode */
1522
1523 #define EXT2_FEATURE_COMPAT_SUPP        EXT4_FEATURE_COMPAT_EXT_ATTR
1524 #define EXT2_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1525                                          EXT4_FEATURE_INCOMPAT_META_BG)
1526 #define EXT2_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1527                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1528                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1529
1530 #define EXT3_FEATURE_COMPAT_SUPP        EXT4_FEATURE_COMPAT_EXT_ATTR
1531 #define EXT3_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1532                                          EXT4_FEATURE_INCOMPAT_RECOVER| \
1533                                          EXT4_FEATURE_INCOMPAT_META_BG)
1534 #define EXT3_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1535                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1536                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1537
1538 #define EXT4_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
1539 #define EXT4_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1540                                          EXT4_FEATURE_INCOMPAT_RECOVER| \
1541                                          EXT4_FEATURE_INCOMPAT_META_BG| \
1542                                          EXT4_FEATURE_INCOMPAT_EXTENTS| \
1543                                          EXT4_FEATURE_INCOMPAT_64BIT| \
1544                                          EXT4_FEATURE_INCOMPAT_FLEX_BG| \
1545                                          EXT4_FEATURE_INCOMPAT_MMP |    \
1546                                          EXT4_FEATURE_INCOMPAT_INLINE_DATA)
1547 #define EXT4_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1548                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1549                                          EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1550                                          EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1551                                          EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1552                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1553                                          EXT4_FEATURE_RO_COMPAT_HUGE_FILE |\
1554                                          EXT4_FEATURE_RO_COMPAT_BIGALLOC |\
1555                                          EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
1556                                          EXT4_FEATURE_RO_COMPAT_QUOTA)
1557
1558 /*
1559  * Default values for user and/or group using reserved blocks
1560  */
1561 #define EXT4_DEF_RESUID         0
1562 #define EXT4_DEF_RESGID         0
1563
1564 #define EXT4_DEF_INODE_READAHEAD_BLKS   32
1565
1566 /*
1567  * Default mount options
1568  */
1569 #define EXT4_DEFM_DEBUG         0x0001
1570 #define EXT4_DEFM_BSDGROUPS     0x0002
1571 #define EXT4_DEFM_XATTR_USER    0x0004
1572 #define EXT4_DEFM_ACL           0x0008
1573 #define EXT4_DEFM_UID16         0x0010
1574 #define EXT4_DEFM_JMODE         0x0060
1575 #define EXT4_DEFM_JMODE_DATA    0x0020
1576 #define EXT4_DEFM_JMODE_ORDERED 0x0040
1577 #define EXT4_DEFM_JMODE_WBACK   0x0060
1578 #define EXT4_DEFM_NOBARRIER     0x0100
1579 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
1580 #define EXT4_DEFM_DISCARD       0x0400
1581 #define EXT4_DEFM_NODELALLOC    0x0800
1582
1583 /*
1584  * Default journal batch times
1585  */
1586 #define EXT4_DEF_MIN_BATCH_TIME 0
1587 #define EXT4_DEF_MAX_BATCH_TIME 15000 /* 15ms */
1588
1589 /*
1590  * Minimum number of groups in a flexgroup before we separate out
1591  * directories into the first block group of a flexgroup
1592  */
1593 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME 4
1594
1595 /*
1596  * Structure of a directory entry
1597  */
1598 #define EXT4_NAME_LEN 255
1599
1600 struct ext4_dir_entry {
1601         __le32  inode;                  /* Inode number */
1602         __le16  rec_len;                /* Directory entry length */
1603         __le16  name_len;               /* Name length */
1604         char    name[EXT4_NAME_LEN];    /* File name */
1605 };
1606
1607 /*
1608  * The new version of the directory entry.  Since EXT4 structures are
1609  * stored in intel byte order, and the name_len field could never be
1610  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1611  * file_type field.
1612  */
1613 struct ext4_dir_entry_2 {
1614         __le32  inode;                  /* Inode number */
1615         __le16  rec_len;                /* Directory entry length */
1616         __u8    name_len;               /* Name length */
1617         __u8    file_type;
1618         char    name[EXT4_NAME_LEN];    /* File name */
1619 };
1620
1621 /*
1622  * This is a bogus directory entry at the end of each leaf block that
1623  * records checksums.
1624  */
1625 struct ext4_dir_entry_tail {
1626         __le32  det_reserved_zero1;     /* Pretend to be unused */
1627         __le16  det_rec_len;            /* 12 */
1628         __u8    det_reserved_zero2;     /* Zero name length */
1629         __u8    det_reserved_ft;        /* 0xDE, fake file type */
1630         __le32  det_checksum;           /* crc32c(uuid+inum+dirblock) */
1631 };
1632
1633 #define EXT4_DIRENT_TAIL(block, blocksize) \
1634         ((struct ext4_dir_entry_tail *)(((void *)(block)) + \
1635                                         ((blocksize) - \
1636                                          sizeof(struct ext4_dir_entry_tail))))
1637
1638 /*
1639  * Ext4 directory file types.  Only the low 3 bits are used.  The
1640  * other bits are reserved for now.
1641  */
1642 #define EXT4_FT_UNKNOWN         0
1643 #define EXT4_FT_REG_FILE        1
1644 #define EXT4_FT_DIR             2
1645 #define EXT4_FT_CHRDEV          3
1646 #define EXT4_FT_BLKDEV          4
1647 #define EXT4_FT_FIFO            5
1648 #define EXT4_FT_SOCK            6
1649 #define EXT4_FT_SYMLINK         7
1650
1651 #define EXT4_FT_MAX             8
1652
1653 #define EXT4_FT_DIR_CSUM        0xDE
1654
1655 /*
1656  * EXT4_DIR_PAD defines the directory entries boundaries
1657  *
1658  * NOTE: It must be a multiple of 4
1659  */
1660 #define EXT4_DIR_PAD                    4
1661 #define EXT4_DIR_ROUND                  (EXT4_DIR_PAD - 1)
1662 #define EXT4_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT4_DIR_ROUND) & \
1663                                          ~EXT4_DIR_ROUND)
1664 #define EXT4_MAX_REC_LEN                ((1<<16)-1)
1665
1666 /*
1667  * If we ever get support for fs block sizes > page_size, we'll need
1668  * to remove the #if statements in the next two functions...
1669  */
1670 static inline unsigned int
1671 ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
1672 {
1673         unsigned len = le16_to_cpu(dlen);
1674
1675 #if (PAGE_CACHE_SIZE >= 65536)
1676         if (len == EXT4_MAX_REC_LEN || len == 0)
1677                 return blocksize;
1678         return (len & 65532) | ((len & 3) << 16);
1679 #else
1680         return len;
1681 #endif
1682 }
1683
1684 static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
1685 {
1686         if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
1687                 BUG();
1688 #if (PAGE_CACHE_SIZE >= 65536)
1689         if (len < 65536)
1690                 return cpu_to_le16(len);
1691         if (len == blocksize) {
1692                 if (blocksize == 65536)
1693                         return cpu_to_le16(EXT4_MAX_REC_LEN);
1694                 else
1695                         return cpu_to_le16(0);
1696         }
1697         return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
1698 #else
1699         return cpu_to_le16(len);
1700 #endif
1701 }
1702
1703 /*
1704  * Hash Tree Directory indexing
1705  * (c) Daniel Phillips, 2001
1706  */
1707
1708 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1709                                       EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1710                     ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
1711 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1712 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1713
1714 /* Legal values for the dx_root hash_version field: */
1715
1716 #define DX_HASH_LEGACY          0
1717 #define DX_HASH_HALF_MD4        1
1718 #define DX_HASH_TEA             2
1719 #define DX_HASH_LEGACY_UNSIGNED 3
1720 #define DX_HASH_HALF_MD4_UNSIGNED       4
1721 #define DX_HASH_TEA_UNSIGNED            5
1722
1723 static inline u32 ext4_chksum(struct ext4_sb_info *sbi, u32 crc,
1724                               const void *address, unsigned int length)
1725 {
1726         struct {
1727                 struct shash_desc shash;
1728                 char ctx[4];
1729         } desc;
1730         int err;
1731
1732         BUG_ON(crypto_shash_descsize(sbi->s_chksum_driver)!=sizeof(desc.ctx));
1733
1734         desc.shash.tfm = sbi->s_chksum_driver;
1735         desc.shash.flags = 0;
1736         *(u32 *)desc.ctx = crc;
1737
1738         err = crypto_shash_update(&desc.shash, address, length);
1739         BUG_ON(err);
1740
1741         return *(u32 *)desc.ctx;
1742 }
1743
1744 #ifdef __KERNEL__
1745
1746 /* hash info structure used by the directory hash */
1747 struct dx_hash_info
1748 {
1749         u32             hash;
1750         u32             minor_hash;
1751         int             hash_version;
1752         u32             *seed;
1753 };
1754
1755
1756 /* 32 and 64 bit signed EOF for dx directories */
1757 #define EXT4_HTREE_EOF_32BIT   ((1UL  << (32 - 1)) - 1)
1758 #define EXT4_HTREE_EOF_64BIT   ((1ULL << (64 - 1)) - 1)
1759
1760
1761 /*
1762  * Control parameters used by ext4_htree_next_block
1763  */
1764 #define HASH_NB_ALWAYS          1
1765
1766
1767 /*
1768  * Describe an inode's exact location on disk and in memory
1769  */
1770 struct ext4_iloc
1771 {
1772         struct buffer_head *bh;
1773         unsigned long offset;
1774         ext4_group_t block_group;
1775 };
1776
1777 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1778 {
1779         return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1780 }
1781
1782 /*
1783  * This structure is stuffed into the struct file's private_data field
1784  * for directories.  It is where we put information so that we can do
1785  * readdir operations in hash tree order.
1786  */
1787 struct dir_private_info {
1788         struct rb_root  root;
1789         struct rb_node  *curr_node;
1790         struct fname    *extra_fname;
1791         loff_t          last_pos;
1792         __u32           curr_hash;
1793         __u32           curr_minor_hash;
1794         __u32           next_hash;
1795 };
1796
1797 /* calculate the first block number of the group */
1798 static inline ext4_fsblk_t
1799 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1800 {
1801         return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1802                 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1803 }
1804
1805 /*
1806  * Special error return code only used by dx_probe() and its callers.
1807  */
1808 #define ERR_BAD_DX_DIR  -75000
1809
1810 /*
1811  * Timeout and state flag for lazy initialization inode thread.
1812  */
1813 #define EXT4_DEF_LI_WAIT_MULT                   10
1814 #define EXT4_DEF_LI_MAX_START_DELAY             5
1815 #define EXT4_LAZYINIT_QUIT                      0x0001
1816 #define EXT4_LAZYINIT_RUNNING                   0x0002
1817
1818 /*
1819  * Lazy inode table initialization info
1820  */
1821 struct ext4_lazy_init {
1822         unsigned long           li_state;
1823         struct list_head        li_request_list;
1824         struct mutex            li_list_mtx;
1825 };
1826
1827 struct ext4_li_request {
1828         struct super_block      *lr_super;
1829         struct ext4_sb_info     *lr_sbi;
1830         ext4_group_t            lr_next_group;
1831         struct list_head        lr_request;
1832         unsigned long           lr_next_sched;
1833         unsigned long           lr_timeout;
1834 };
1835
1836 struct ext4_features {
1837         struct kobject f_kobj;
1838         struct completion f_kobj_unregister;
1839 };
1840
1841 /*
1842  * This structure will be used for multiple mount protection. It will be
1843  * written into the block number saved in the s_mmp_block field in the
1844  * superblock. Programs that check MMP should assume that if
1845  * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
1846  * to use the filesystem, regardless of how old the timestamp is.
1847  */
1848 #define EXT4_MMP_MAGIC     0x004D4D50U /* ASCII for MMP */
1849 #define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
1850 #define EXT4_MMP_SEQ_FSCK  0xE24D4D50U /* mmp_seq value when being fscked */
1851 #define EXT4_MMP_SEQ_MAX   0xE24D4D4FU /* maximum valid mmp_seq value */
1852
1853 struct mmp_struct {
1854         __le32  mmp_magic;              /* Magic number for MMP */
1855         __le32  mmp_seq;                /* Sequence no. updated periodically */
1856
1857         /*
1858          * mmp_time, mmp_nodename & mmp_bdevname are only used for information
1859          * purposes and do not affect the correctness of the algorithm
1860          */
1861         __le64  mmp_time;               /* Time last updated */
1862         char    mmp_nodename[64];       /* Node which last updated MMP block */
1863         char    mmp_bdevname[32];       /* Bdev which last updated MMP block */
1864
1865         /*
1866          * mmp_check_interval is used to verify if the MMP block has been
1867          * updated on the block device. The value is updated based on the
1868          * maximum time to write the MMP block during an update cycle.
1869          */
1870         __le16  mmp_check_interval;
1871
1872         __le16  mmp_pad1;
1873         __le32  mmp_pad2[226];
1874         __le32  mmp_checksum;           /* crc32c(uuid+mmp_block) */
1875 };
1876
1877 /* arguments passed to the mmp thread */
1878 struct mmpd_data {
1879         struct buffer_head *bh; /* bh from initial read_mmp_block() */
1880         struct super_block *sb;  /* super block of the fs */
1881 };
1882
1883 /*
1884  * Check interval multiplier
1885  * The MMP block is written every update interval and initially checked every
1886  * update interval x the multiplier (the value is then adapted based on the
1887  * write latency). The reason is that writes can be delayed under load and we
1888  * don't want readers to incorrectly assume that the filesystem is no longer
1889  * in use.
1890  */
1891 #define EXT4_MMP_CHECK_MULT             2UL
1892
1893 /*
1894  * Minimum interval for MMP checking in seconds.
1895  */
1896 #define EXT4_MMP_MIN_CHECK_INTERVAL     5UL
1897
1898 /*
1899  * Maximum interval for MMP checking in seconds.
1900  */
1901 #define EXT4_MMP_MAX_CHECK_INTERVAL     300UL
1902
1903 /*
1904  * Function prototypes
1905  */
1906
1907 /*
1908  * Ok, these declarations are also in <linux/kernel.h> but none of the
1909  * ext4 source programs needs to include it so they are duplicated here.
1910  */
1911 # define NORET_TYPE     /**/
1912 # define ATTRIB_NORET   __attribute__((noreturn))
1913 # define NORET_AND      noreturn,
1914
1915 /* bitmap.c */
1916 extern unsigned int ext4_count_free(char *bitmap, unsigned numchars);
1917 void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1918                                 struct ext4_group_desc *gdp,
1919                                 struct buffer_head *bh, int sz);
1920 int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1921                                   struct ext4_group_desc *gdp,
1922                                   struct buffer_head *bh, int sz);
1923 void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1924                                 struct ext4_group_desc *gdp,
1925                                 struct buffer_head *bh);
1926 int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1927                                   struct ext4_group_desc *gdp,
1928                                   struct buffer_head *bh);
1929
1930 /* balloc.c */
1931 extern void ext4_get_group_no_and_offset(struct super_block *sb,
1932                                          ext4_fsblk_t blocknr,
1933                                          ext4_group_t *blockgrpp,
1934                                          ext4_grpblk_t *offsetp);
1935 extern ext4_group_t ext4_get_group_number(struct super_block *sb,
1936                                           ext4_fsblk_t block);
1937
1938 extern void ext4_validate_block_bitmap(struct super_block *sb,
1939                                        struct ext4_group_desc *desc,
1940                                        ext4_group_t block_group,
1941                                        struct buffer_head *bh);
1942 extern unsigned int ext4_block_group(struct super_block *sb,
1943                         ext4_fsblk_t blocknr);
1944 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1945                         ext4_fsblk_t blocknr);
1946 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1947 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1948                         ext4_group_t group);
1949 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1950                                          ext4_fsblk_t goal,
1951                                          unsigned int flags,
1952                                          unsigned long *count,
1953                                          int *errp);
1954 extern int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
1955                                     s64 nclusters, unsigned int flags);
1956 extern ext4_fsblk_t ext4_count_free_clusters(struct super_block *);
1957 extern void ext4_check_blocks_bitmap(struct super_block *);
1958 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1959                                                     ext4_group_t block_group,
1960                                                     struct buffer_head ** bh);
1961 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1962
1963 extern struct buffer_head *ext4_read_block_bitmap_nowait(struct super_block *sb,
1964                                                 ext4_group_t block_group);
1965 extern int ext4_wait_block_bitmap(struct super_block *sb,
1966                                   ext4_group_t block_group,
1967                                   struct buffer_head *bh);
1968 extern struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1969                                                   ext4_group_t block_group);
1970 extern void ext4_init_block_bitmap(struct super_block *sb,
1971                                    struct buffer_head *bh,
1972                                    ext4_group_t group,
1973                                    struct ext4_group_desc *desc);
1974 extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
1975                                               ext4_group_t block_group,
1976                                               struct ext4_group_desc *gdp);
1977 extern unsigned ext4_num_overhead_clusters(struct super_block *sb,
1978                                            ext4_group_t block_group,
1979                                            struct ext4_group_desc *gdp);
1980 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
1981
1982 /* dir.c */
1983 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
1984                                   struct file *,
1985                                   struct ext4_dir_entry_2 *,
1986                                   struct buffer_head *, char *, int,
1987                                   unsigned int);
1988 #define ext4_check_dir_entry(dir, filp, de, bh, buf, size, offset)      \
1989         unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
1990                                         (de), (bh), (buf), (size), (offset)))
1991 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1992                                     __u32 minor_hash,
1993                                     struct ext4_dir_entry_2 *dirent);
1994 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
1995 extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1996                              struct buffer_head *bh,
1997                              void *buf, int buf_size,
1998                              const char *name, int namelen,
1999                              struct ext4_dir_entry_2 **dest_de);
2000 void ext4_insert_dentry(struct inode *inode,
2001                         struct ext4_dir_entry_2 *de,
2002                         int buf_size,
2003                         const char *name, int namelen);
2004 static inline void ext4_update_dx_flag(struct inode *inode)
2005 {
2006         if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
2007                                      EXT4_FEATURE_COMPAT_DIR_INDEX))
2008                 ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
2009 }
2010 static unsigned char ext4_filetype_table[] = {
2011         DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
2012 };
2013
2014 static inline  unsigned char get_dtype(struct super_block *sb, int filetype)
2015 {
2016         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE) ||
2017             (filetype >= EXT4_FT_MAX))
2018                 return DT_UNKNOWN;
2019
2020         return ext4_filetype_table[filetype];
2021 }
2022
2023 /* fsync.c */
2024 extern int ext4_sync_file(struct file *, loff_t, loff_t, int);
2025
2026 /* hash.c */
2027 extern int ext4fs_dirhash(const char *name, int len, struct
2028                           dx_hash_info *hinfo);
2029
2030 /* ialloc.c */
2031 extern struct inode *__ext4_new_inode(handle_t *, struct inode *, umode_t,
2032                                       const struct qstr *qstr, __u32 goal,
2033                                       uid_t *owner, int handle_type,
2034                                       unsigned int line_no, int nblocks);
2035
2036 #define ext4_new_inode(handle, dir, mode, qstr, goal, owner) \
2037         __ext4_new_inode((handle), (dir), (mode), (qstr), (goal), (owner), \
2038                          0, 0, 0)
2039 #define ext4_new_inode_start_handle(dir, mode, qstr, goal, owner, \
2040                                     type, nblocks)                  \
2041         __ext4_new_inode(NULL, (dir), (mode), (qstr), (goal), (owner), \
2042                          (type), __LINE__, (nblocks))
2043
2044
2045 extern void ext4_free_inode(handle_t *, struct inode *);
2046 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
2047 extern unsigned long ext4_count_free_inodes(struct super_block *);
2048 extern unsigned long ext4_count_dirs(struct super_block *);
2049 extern void ext4_check_inodes_bitmap(struct super_block *);
2050 extern void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
2051 extern int ext4_init_inode_table(struct super_block *sb,
2052                                  ext4_group_t group, int barrier);
2053 extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
2054
2055 /* mballoc.c */
2056 extern long ext4_mb_stats;
2057 extern long ext4_mb_max_to_scan;
2058 extern int ext4_mb_init(struct super_block *);
2059 extern int ext4_mb_release(struct super_block *);
2060 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
2061                                 struct ext4_allocation_request *, int *);
2062 extern int ext4_mb_reserve_blocks(struct super_block *, int);
2063 extern void ext4_discard_preallocations(struct inode *);
2064 extern int __init ext4_init_mballoc(void);
2065 extern void ext4_exit_mballoc(void);
2066 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
2067                              struct buffer_head *bh, ext4_fsblk_t block,
2068                              unsigned long count, int flags);
2069 extern int ext4_mb_alloc_groupinfo(struct super_block *sb,
2070                                    ext4_group_t ngroups);
2071 extern int ext4_mb_add_groupinfo(struct super_block *sb,
2072                 ext4_group_t i, struct ext4_group_desc *desc);
2073 extern int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
2074                                 ext4_fsblk_t block, unsigned long count);
2075 extern int ext4_trim_fs(struct super_block *, struct fstrim_range *);
2076
2077 /* inode.c */
2078 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
2079                                                 ext4_lblk_t, int, int *);
2080 struct buffer_head *ext4_bread(handle_t *, struct inode *,
2081                                                 ext4_lblk_t, int, int *);
2082 int ext4_get_block_write(struct inode *inode, sector_t iblock,
2083                          struct buffer_head *bh_result, int create);
2084 int ext4_get_block(struct inode *inode, sector_t iblock,
2085                                 struct buffer_head *bh_result, int create);
2086 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
2087                            struct buffer_head *bh, int create);
2088 int ext4_walk_page_buffers(handle_t *handle,
2089                            struct buffer_head *head,
2090                            unsigned from,
2091                            unsigned to,
2092                            int *partial,
2093                            int (*fn)(handle_t *handle,
2094                                      struct buffer_head *bh));
2095 int do_journal_get_write_access(handle_t *handle,
2096                                 struct buffer_head *bh);
2097 #define FALL_BACK_TO_NONDELALLOC 1
2098 #define CONVERT_INLINE_DATA      2
2099
2100 extern struct inode *ext4_iget(struct super_block *, unsigned long);
2101 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
2102 extern int  ext4_setattr(struct dentry *, struct iattr *);
2103 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
2104                                 struct kstat *stat);
2105 extern void ext4_evict_inode(struct inode *);
2106 extern void ext4_clear_inode(struct inode *);
2107 extern int  ext4_sync_inode(handle_t *, struct inode *);
2108 extern void ext4_dirty_inode(struct inode *, int);
2109 extern int ext4_change_inode_journal_flag(struct inode *, int);
2110 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
2111 extern int ext4_inode_attach_jinode(struct inode *inode);
2112 extern int ext4_can_truncate(struct inode *inode);
2113 extern void ext4_truncate(struct inode *);
2114 extern int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length);
2115 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
2116 extern void ext4_set_inode_flags(struct inode *);
2117 extern void ext4_get_inode_flags(struct ext4_inode_info *);
2118 extern int ext4_alloc_da_blocks(struct inode *inode);
2119 extern void ext4_set_aops(struct inode *inode);
2120 extern int ext4_writepage_trans_blocks(struct inode *);
2121 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
2122 extern int ext4_block_truncate_page(handle_t *handle,
2123                 struct address_space *mapping, loff_t from);
2124 extern int ext4_block_zero_page_range(handle_t *handle,
2125                 struct address_space *mapping, loff_t from, loff_t length);
2126 extern int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
2127                              loff_t lstart, loff_t lend);
2128 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
2129 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
2130 extern void ext4_da_update_reserve_space(struct inode *inode,
2131                                         int used, int quota_claim);
2132
2133 /* indirect.c */
2134 extern int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
2135                                 struct ext4_map_blocks *map, int flags);
2136 extern ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb,
2137                                 const struct iovec *iov, loff_t offset,
2138                                 unsigned long nr_segs);
2139 extern int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock);
2140 extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks);
2141 extern void ext4_ind_truncate(handle_t *, struct inode *inode);
2142 extern int ext4_free_hole_blocks(handle_t *handle, struct inode *inode,
2143                                  ext4_lblk_t first, ext4_lblk_t stop);
2144
2145 /* ioctl.c */
2146 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
2147 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
2148
2149 /* migrate.c */
2150 extern int ext4_ext_migrate(struct inode *);
2151 extern int ext4_ind_migrate(struct inode *inode);
2152
2153 /* namei.c */
2154 extern int ext4_dirent_csum_verify(struct inode *inode,
2155                                    struct ext4_dir_entry *dirent);
2156 extern int ext4_orphan_add(handle_t *, struct inode *);
2157 extern int ext4_orphan_del(handle_t *, struct inode *);
2158 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
2159                                 __u32 start_minor_hash, __u32 *next_hash);
2160 extern int search_dir(struct buffer_head *bh,
2161                       char *search_buf,
2162                       int buf_size,
2163                       struct inode *dir,
2164                       const struct qstr *d_name,
2165                       unsigned int offset,
2166                       struct ext4_dir_entry_2 **res_dir);
2167 extern int ext4_generic_delete_entry(handle_t *handle,
2168                                      struct inode *dir,
2169                                      struct ext4_dir_entry_2 *de_del,
2170                                      struct buffer_head *bh,
2171                                      void *entry_buf,
2172                                      int buf_size,
2173                                      int csum_size);
2174
2175 /* resize.c */
2176 extern int ext4_group_add(struct super_block *sb,
2177                                 struct ext4_new_group_data *input);
2178 extern int ext4_group_extend(struct super_block *sb,
2179                                 struct ext4_super_block *es,
2180                                 ext4_fsblk_t n_blocks_count);
2181 extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
2182
2183 /* super.c */
2184 extern int ext4_calculate_overhead(struct super_block *sb);
2185 extern int ext4_superblock_csum_verify(struct super_block *sb,
2186                                        struct ext4_super_block *es);
2187 extern void ext4_superblock_csum_set(struct super_block *sb);
2188 extern void *ext4_kvmalloc(size_t size, gfp_t flags);
2189 extern void *ext4_kvzalloc(size_t size, gfp_t flags);
2190 extern void ext4_kvfree(void *ptr);
2191 extern int ext4_alloc_flex_bg_array(struct super_block *sb,
2192                                     ext4_group_t ngroup);
2193 extern const char *ext4_decode_error(struct super_block *sb, int errno,
2194                                      char nbuf[16]);
2195
2196 extern __printf(4, 5)
2197 void __ext4_error(struct super_block *, const char *, unsigned int,
2198                   const char *, ...);
2199 extern __printf(5, 6)
2200 void __ext4_error_inode(struct inode *, const char *, unsigned int, ext4_fsblk_t,
2201                       const char *, ...);
2202 extern __printf(5, 6)
2203 void __ext4_error_file(struct file *, const char *, unsigned int, ext4_fsblk_t,
2204                      const char *, ...);
2205 extern void __ext4_std_error(struct super_block *, const char *,
2206                              unsigned int, int);
2207 extern __printf(4, 5)
2208 void __ext4_abort(struct super_block *, const char *, unsigned int,
2209                   const char *, ...);
2210 extern __printf(4, 5)
2211 void __ext4_warning(struct super_block *, const char *, unsigned int,
2212                     const char *, ...);
2213 extern __printf(3, 4)
2214 void __ext4_msg(struct super_block *, const char *, const char *, ...);
2215 extern void __dump_mmp_msg(struct super_block *, struct mmp_struct *mmp,
2216                            const char *, unsigned int, const char *);
2217 extern __printf(7, 8)
2218 void __ext4_grp_locked_error(const char *, unsigned int,
2219                              struct super_block *, ext4_group_t,
2220                              unsigned long, ext4_fsblk_t,
2221                              const char *, ...);
2222
2223 #ifdef CONFIG_PRINTK
2224
2225 #define ext4_error_inode(inode, func, line, block, fmt, ...)            \
2226         __ext4_error_inode(inode, func, line, block, fmt, ##__VA_ARGS__)
2227 #define ext4_error_file(file, func, line, block, fmt, ...)              \
2228         __ext4_error_file(file, func, line, block, fmt, ##__VA_ARGS__)
2229 #define ext4_error(sb, fmt, ...)                                        \
2230         __ext4_error(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2231 #define ext4_abort(sb, fmt, ...)                                        \
2232         __ext4_abort(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2233 #define ext4_warning(sb, fmt, ...)                                      \
2234         __ext4_warning(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2235 #define ext4_msg(sb, level, fmt, ...)                           \
2236         __ext4_msg(sb, level, fmt, ##__VA_ARGS__)
2237 #define dump_mmp_msg(sb, mmp, msg)                                      \
2238         __dump_mmp_msg(sb, mmp, __func__, __LINE__, msg)
2239 #define ext4_grp_locked_error(sb, grp, ino, block, fmt, ...)            \
2240         __ext4_grp_locked_error(__func__, __LINE__, sb, grp, ino, block, \
2241                                 fmt, ##__VA_ARGS__)
2242
2243 #else
2244
2245 #define ext4_error_inode(inode, func, line, block, fmt, ...)            \
2246 do {                                                                    \
2247         no_printk(fmt, ##__VA_ARGS__);                                  \
2248         __ext4_error_inode(inode, "", 0, block, " ");                   \
2249 } while (0)
2250 #define ext4_error_file(file, func, line, block, fmt, ...)              \
2251 do {                                                                    \
2252         no_printk(fmt, ##__VA_ARGS__);                                  \
2253         __ext4_error_file(file, "", 0, block, " ");                     \
2254 } while (0)
2255 #define ext4_error(sb, fmt, ...)                                        \
2256 do {                                                                    \
2257         no_printk(fmt, ##__VA_ARGS__);                                  \
2258         __ext4_error(sb, "", 0, " ");                                   \
2259 } while (0)
2260 #define ext4_abort(sb, fmt, ...)                                        \
2261 do {                                                                    \
2262         no_printk(fmt, ##__VA_ARGS__);                                  \
2263         __ext4_abort(sb, "", 0, " ");                                   \
2264 } while (0)
2265 #define ext4_warning(sb, fmt, ...)                                      \
2266 do {                                                                    \
2267         no_printk(fmt, ##__VA_ARGS__);                                  \
2268         __ext4_warning(sb, "", 0, " ");                                 \
2269 } while (0)
2270 #define ext4_msg(sb, level, fmt, ...)                                   \
2271 do {                                                                    \
2272         no_printk(fmt, ##__VA_ARGS__);                                  \
2273         __ext4_msg(sb, "", " ");                                        \
2274 } while (0)
2275 #define dump_mmp_msg(sb, mmp, msg)                                      \
2276         __dump_mmp_msg(sb, mmp, "", 0, "")
2277 #define ext4_grp_locked_error(sb, grp, ino, block, fmt, ...)            \
2278 do {                                                                    \
2279         no_printk(fmt, ##__VA_ARGS__);                          \
2280         __ext4_grp_locked_error("", 0, sb, grp, ino, block, " ");       \
2281 } while (0)
2282
2283 #endif
2284
2285 extern void ext4_update_dynamic_rev(struct super_block *sb);
2286 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
2287                                         __u32 compat);
2288 extern int ext4_update_rocompat_feature(handle_t *handle,
2289                                         struct super_block *sb, __u32 rocompat);
2290 extern int ext4_update_incompat_feature(handle_t *handle,
2291                                         struct super_block *sb, __u32 incompat);
2292 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
2293                                       struct ext4_group_desc *bg);
2294 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
2295                                       struct ext4_group_desc *bg);
2296 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
2297                                      struct ext4_group_desc *bg);
2298 extern __u32 ext4_free_group_clusters(struct super_block *sb,
2299                                       struct ext4_group_desc *bg);
2300 extern __u32 ext4_free_inodes_count(struct super_block *sb,
2301                                  struct ext4_group_desc *bg);
2302 extern __u32 ext4_used_dirs_count(struct super_block *sb,
2303                                 struct ext4_group_desc *bg);
2304 extern __u32 ext4_itable_unused_count(struct super_block *sb,
2305                                    struct ext4_group_desc *bg);
2306 extern void ext4_block_bitmap_set(struct super_block *sb,
2307                                   struct ext4_group_desc *bg, ext4_fsblk_t blk);
2308 extern void ext4_inode_bitmap_set(struct super_block *sb,
2309                                   struct ext4_group_desc *bg, ext4_fsblk_t blk);
2310 extern void ext4_inode_table_set(struct super_block *sb,
2311                                  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2312 extern void ext4_free_group_clusters_set(struct super_block *sb,
2313                                          struct ext4_group_desc *bg,
2314                                          __u32 count);
2315 extern void ext4_free_inodes_set(struct super_block *sb,
2316                                 struct ext4_group_desc *bg, __u32 count);
2317 extern void ext4_used_dirs_set(struct super_block *sb,
2318                                 struct ext4_group_desc *bg, __u32 count);
2319 extern void ext4_itable_unused_set(struct super_block *sb,
2320                                    struct ext4_group_desc *bg, __u32 count);
2321 extern int ext4_group_desc_csum_verify(struct super_block *sb, __u32 group,
2322                                        struct ext4_group_desc *gdp);
2323 extern void ext4_group_desc_csum_set(struct super_block *sb, __u32 group,
2324                                      struct ext4_group_desc *gdp);
2325 extern int ext4_register_li_request(struct super_block *sb,
2326                                     ext4_group_t first_not_zeroed);
2327
2328 static inline int ext4_has_group_desc_csum(struct super_block *sb)
2329 {
2330         return EXT4_HAS_RO_COMPAT_FEATURE(sb,
2331                                           EXT4_FEATURE_RO_COMPAT_GDT_CSUM |
2332                                           EXT4_FEATURE_RO_COMPAT_METADATA_CSUM);
2333 }
2334
2335 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
2336 {
2337         return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
2338                 le32_to_cpu(es->s_blocks_count_lo);
2339 }
2340
2341 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
2342 {
2343         return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
2344                 le32_to_cpu(es->s_r_blocks_count_lo);
2345 }
2346
2347 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
2348 {
2349         return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
2350                 le32_to_cpu(es->s_free_blocks_count_lo);
2351 }
2352
2353 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
2354                                          ext4_fsblk_t blk)
2355 {
2356         es->s_blocks_count_lo = cpu_to_le32((u32)blk);
2357         es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
2358 }
2359
2360 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
2361                                               ext4_fsblk_t blk)
2362 {
2363         es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
2364         es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
2365 }
2366
2367 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
2368                                            ext4_fsblk_t blk)
2369 {
2370         es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
2371         es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
2372 }
2373
2374 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
2375 {
2376         if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
2377                 return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
2378                         le32_to_cpu(raw_inode->i_size_lo);
2379         else
2380                 return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
2381 }
2382
2383 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
2384 {
2385         raw_inode->i_size_lo = cpu_to_le32(i_size);
2386         raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
2387 }
2388
2389 static inline
2390 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
2391                                             ext4_group_t group)
2392 {
2393          struct ext4_group_info ***grp_info;
2394          long indexv, indexh;
2395          BUG_ON(group >= EXT4_SB(sb)->s_groups_count);
2396          grp_info = EXT4_SB(sb)->s_group_info;
2397          indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
2398          indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
2399          return grp_info[indexv][indexh];
2400 }
2401
2402 /*
2403  * Reading s_groups_count requires using smp_rmb() afterwards.  See
2404  * the locking protocol documented in the comments of ext4_group_add()
2405  * in resize.c
2406  */
2407 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
2408 {
2409         ext4_group_t    ngroups = EXT4_SB(sb)->s_groups_count;
2410
2411         smp_rmb();
2412         return ngroups;
2413 }
2414
2415 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
2416                                              ext4_group_t block_group)
2417 {
2418         return block_group >> sbi->s_log_groups_per_flex;
2419 }
2420
2421 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
2422 {
2423         return 1 << sbi->s_log_groups_per_flex;
2424 }
2425
2426 #define ext4_std_error(sb, errno)                               \
2427 do {                                                            \
2428         if ((errno))                                            \
2429                 __ext4_std_error((sb), __func__, __LINE__, (errno));    \
2430 } while (0)
2431
2432 #ifdef CONFIG_SMP
2433 /* Each CPU can accumulate percpu_counter_batch clusters in their local
2434  * counters. So we need to make sure we have free clusters more
2435  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
2436  */
2437 #define EXT4_FREECLUSTERS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
2438 #else
2439 #define EXT4_FREECLUSTERS_WATERMARK 0
2440 #endif
2441
2442 /* Update i_disksize. Requires i_mutex to avoid races with truncate */
2443 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
2444 {
2445         WARN_ON_ONCE(S_ISREG(inode->i_mode) &&
2446                      !mutex_is_locked(&inode->i_mutex));
2447         down_write(&EXT4_I(inode)->i_data_sem);
2448         if (newsize > EXT4_I(inode)->i_disksize)
2449                 EXT4_I(inode)->i_disksize = newsize;
2450         up_write(&EXT4_I(inode)->i_data_sem);
2451 }
2452
2453 /*
2454  * Update i_disksize after writeback has been started. Races with truncate
2455  * are avoided by checking i_size under i_data_sem.
2456  */
2457 static inline void ext4_wb_update_i_disksize(struct inode *inode, loff_t newsize)
2458 {
2459         loff_t i_size;
2460
2461         down_write(&EXT4_I(inode)->i_data_sem);
2462         i_size = i_size_read(inode);
2463         if (newsize > i_size)
2464                 newsize = i_size;
2465         if (newsize > EXT4_I(inode)->i_disksize)
2466                 EXT4_I(inode)->i_disksize = newsize;
2467         up_write(&EXT4_I(inode)->i_data_sem);
2468 }
2469
2470 struct ext4_group_info {
2471         unsigned long   bb_state;
2472         struct rb_root  bb_free_root;
2473         ext4_grpblk_t   bb_first_free;  /* first free block */
2474         ext4_grpblk_t   bb_free;        /* total free blocks */
2475         ext4_grpblk_t   bb_fragments;   /* nr of freespace fragments */
2476         ext4_grpblk_t   bb_largest_free_order;/* order of largest frag in BG */
2477         struct          list_head bb_prealloc_list;
2478 #ifdef DOUBLE_CHECK
2479         void            *bb_bitmap;
2480 #endif
2481         struct rw_semaphore alloc_sem;
2482         ext4_grpblk_t   bb_counters[];  /* Nr of free power-of-two-block
2483                                          * regions, index is order.
2484                                          * bb_counters[3] = 5 means
2485                                          * 5 free 8-block regions. */
2486 };
2487
2488 #define EXT4_GROUP_INFO_NEED_INIT_BIT           0
2489 #define EXT4_GROUP_INFO_WAS_TRIMMED_BIT         1
2490 #define EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT     2
2491 #define EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT     3
2492
2493 #define EXT4_MB_GRP_NEED_INIT(grp)      \
2494         (test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
2495 #define EXT4_MB_GRP_BBITMAP_CORRUPT(grp)        \
2496         (test_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
2497 #define EXT4_MB_GRP_IBITMAP_CORRUPT(grp)        \
2498         (test_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
2499
2500 #define EXT4_MB_GRP_WAS_TRIMMED(grp)    \
2501         (test_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2502 #define EXT4_MB_GRP_SET_TRIMMED(grp)    \
2503         (set_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2504 #define EXT4_MB_GRP_CLEAR_TRIMMED(grp)  \
2505         (clear_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2506
2507 #define EXT4_MAX_CONTENTION             8
2508 #define EXT4_CONTENTION_THRESHOLD       2
2509
2510 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
2511                                               ext4_group_t group)
2512 {
2513         return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
2514 }
2515
2516 /*
2517  * Returns true if the filesystem is busy enough that attempts to
2518  * access the block group locks has run into contention.
2519  */
2520 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
2521 {
2522         return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
2523 }
2524
2525 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
2526 {
2527         spinlock_t *lock = ext4_group_lock_ptr(sb, group);
2528         if (spin_trylock(lock))
2529                 /*
2530                  * We're able to grab the lock right away, so drop the
2531                  * lock contention counter.
2532                  */
2533                 atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
2534         else {
2535                 /*
2536                  * The lock is busy, so bump the contention counter,
2537                  * and then wait on the spin lock.
2538                  */
2539                 atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
2540                                   EXT4_MAX_CONTENTION);
2541                 spin_lock(lock);
2542         }
2543 }
2544
2545 static inline void ext4_unlock_group(struct super_block *sb,
2546                                         ext4_group_t group)
2547 {
2548         spin_unlock(ext4_group_lock_ptr(sb, group));
2549 }
2550
2551 /*
2552  * Block validity checking
2553  */
2554 #define ext4_check_indirect_blockref(inode, bh)                         \
2555         ext4_check_blockref(__func__, __LINE__, inode,                  \
2556                             (__le32 *)(bh)->b_data,                     \
2557                             EXT4_ADDR_PER_BLOCK((inode)->i_sb))
2558
2559 #define ext4_ind_check_inode(inode)                                     \
2560         ext4_check_blockref(__func__, __LINE__, inode,                  \
2561                             EXT4_I(inode)->i_data,                      \
2562                             EXT4_NDIR_BLOCKS)
2563
2564 /*
2565  * Inodes and files operations
2566  */
2567
2568 /* dir.c */
2569 extern const struct file_operations ext4_dir_operations;
2570
2571 /* file.c */
2572 extern const struct inode_operations ext4_file_inode_operations;
2573 extern const struct file_operations ext4_file_operations;
2574 extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
2575 extern void ext4_unwritten_wait(struct inode *inode);
2576
2577 /* inline.c */
2578 extern int ext4_has_inline_data(struct inode *inode);
2579 extern int ext4_get_inline_size(struct inode *inode);
2580 extern int ext4_get_max_inline_size(struct inode *inode);
2581 extern int ext4_find_inline_data_nolock(struct inode *inode);
2582 extern void ext4_write_inline_data(struct inode *inode,
2583                                    struct ext4_iloc *iloc,
2584                                    void *buffer, loff_t pos,
2585                                    unsigned int len);
2586 extern int ext4_prepare_inline_data(handle_t *handle, struct inode *inode,
2587                                     unsigned int len);
2588 extern int ext4_init_inline_data(handle_t *handle, struct inode *inode,
2589                                  unsigned int len);
2590 extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);
2591
2592 extern int ext4_readpage_inline(struct inode *inode, struct page *page);
2593 extern int ext4_try_to_write_inline_data(struct address_space *mapping,
2594                                          struct inode *inode,
2595                                          loff_t pos, unsigned len,
2596                                          unsigned flags,
2597                                          struct page **pagep);
2598 extern int ext4_write_inline_data_end(struct inode *inode,
2599                                       loff_t pos, unsigned len,
2600                                       unsigned copied,
2601                                       struct page *page);
2602 extern struct buffer_head *
2603 ext4_journalled_write_inline_data(struct inode *inode,
2604                                   unsigned len,
2605                                   struct page *page);
2606 extern int ext4_da_write_inline_data_begin(struct address_space *mapping,
2607                                            struct inode *inode,
2608                                            loff_t pos, unsigned len,
2609                                            unsigned flags,
2610                                            struct page **pagep,
2611                                            void **fsdata);
2612 extern int ext4_da_write_inline_data_end(struct inode *inode, loff_t pos,
2613                                          unsigned len, unsigned copied,
2614                                          struct page *page);
2615 extern int ext4_try_add_inline_entry(handle_t *handle, struct dentry *dentry,
2616                                      struct inode *inode);
2617 extern int ext4_try_create_inline_dir(handle_t *handle,
2618                                       struct inode *parent,
2619                                       struct inode *inode);
2620 extern int ext4_read_inline_dir(struct file *filp,
2621                                 struct dir_context *ctx,
2622                                 int *has_inline_data);
2623 extern int htree_inlinedir_to_tree(struct file *dir_file,
2624                                    struct inode *dir, ext4_lblk_t block,
2625                                    struct dx_hash_info *hinfo,
2626                                    __u32 start_hash, __u32 start_minor_hash,
2627                                    int *has_inline_data);
2628 extern struct buffer_head *ext4_find_inline_entry(struct inode *dir,
2629                                         const struct qstr *d_name,
2630                                         struct ext4_dir_entry_2 **res_dir,
2631                                         int *has_inline_data);
2632 extern int ext4_delete_inline_entry(handle_t *handle,
2633                                     struct inode *dir,
2634                                     struct ext4_dir_entry_2 *de_del,
2635                                     struct buffer_head *bh,
2636                                     int *has_inline_data);
2637 extern int empty_inline_dir(struct inode *dir, int *has_inline_data);
2638 extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
2639                                         struct ext4_dir_entry_2 **parent_de,
2640                                         int *retval);
2641 extern int ext4_inline_data_fiemap(struct inode *inode,
2642                                    struct fiemap_extent_info *fieinfo,
2643                                    int *has_inline);
2644 extern int ext4_try_to_evict_inline_data(handle_t *handle,
2645                                          struct inode *inode,
2646                                          int needed);
2647 extern void ext4_inline_data_truncate(struct inode *inode, int *has_inline);
2648
2649 extern int ext4_convert_inline_data(struct inode *inode);
2650
2651 /* namei.c */
2652 extern const struct inode_operations ext4_dir_inode_operations;
2653 extern const struct inode_operations ext4_special_inode_operations;
2654 extern struct dentry *ext4_get_parent(struct dentry *child);
2655 extern struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2656                                  struct ext4_dir_entry_2 *de,
2657                                  int blocksize, int csum_size,
2658                                  unsigned int parent_ino, int dotdot_real_len);
2659 extern void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
2660                                    unsigned int blocksize);
2661 extern int ext4_handle_dirty_dirent_node(handle_t *handle,
2662                                          struct inode *inode,
2663                                          struct buffer_head *bh);
2664 #define S_SHIFT 12
2665 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
2666         [S_IFREG >> S_SHIFT]    = EXT4_FT_REG_FILE,
2667         [S_IFDIR >> S_SHIFT]    = EXT4_FT_DIR,
2668         [S_IFCHR >> S_SHIFT]    = EXT4_FT_CHRDEV,
2669         [S_IFBLK >> S_SHIFT]    = EXT4_FT_BLKDEV,
2670         [S_IFIFO >> S_SHIFT]    = EXT4_FT_FIFO,
2671         [S_IFSOCK >> S_SHIFT]   = EXT4_FT_SOCK,
2672         [S_IFLNK >> S_SHIFT]    = EXT4_FT_SYMLINK,
2673 };
2674
2675 static inline void ext4_set_de_type(struct super_block *sb,
2676                                 struct ext4_dir_entry_2 *de,
2677                                 umode_t mode) {
2678         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
2679                 de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
2680 }
2681
2682
2683 /* symlink.c */
2684 extern const struct inode_operations ext4_symlink_inode_operations;
2685 extern const struct inode_operations ext4_fast_symlink_inode_operations;
2686
2687 /* block_validity */
2688 extern void ext4_release_system_zone(struct super_block *sb);
2689 extern int ext4_setup_system_zone(struct super_block *sb);
2690 extern int __init ext4_init_system_zone(void);
2691 extern void ext4_exit_system_zone(void);
2692 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
2693                                  ext4_fsblk_t start_blk,
2694                                  unsigned int count);
2695 extern int ext4_check_blockref(const char *, unsigned int,
2696                                struct inode *, __le32 *, unsigned int);
2697
2698 /* extents.c */
2699 struct ext4_ext_path;
2700 struct ext4_extent;
2701
2702 /*
2703  * Maximum number of logical blocks in a file; ext4_extent's ee_block is
2704  * __le32.
2705  */
2706 #define EXT_MAX_BLOCKS  0xffffffff
2707
2708 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
2709 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
2710 extern int ext4_ext_index_trans_blocks(struct inode *inode, int extents);
2711 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
2712                                struct ext4_map_blocks *map, int flags);
2713 extern void ext4_ext_truncate(handle_t *, struct inode *);
2714 extern int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2715                                  ext4_lblk_t end);
2716 extern void ext4_ext_init(struct super_block *);
2717 extern void ext4_ext_release(struct super_block *);
2718 extern long ext4_fallocate(struct file *file, int mode, loff_t offset,
2719                           loff_t len);
2720 extern int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
2721                                           loff_t offset, ssize_t len);
2722 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
2723                            struct ext4_map_blocks *map, int flags);
2724 extern int ext4_ext_calc_metadata_amount(struct inode *inode,
2725                                          ext4_lblk_t lblocks);
2726 extern int ext4_extent_tree_init(handle_t *, struct inode *);
2727 extern int ext4_ext_calc_credits_for_single_extent(struct inode *inode,
2728                                                    int num,
2729                                                    struct ext4_ext_path *path);
2730 extern int ext4_can_extents_be_merged(struct inode *inode,
2731                                       struct ext4_extent *ex1,
2732                                       struct ext4_extent *ex2);
2733 extern int ext4_ext_insert_extent(handle_t *, struct inode *,
2734                                   struct ext4_ext_path *,
2735                                   struct ext4_extent *, int);
2736 extern struct ext4_ext_path *ext4_ext_find_extent(struct inode *, ext4_lblk_t,
2737                                                   struct ext4_ext_path *,
2738                                                   int flags);
2739 extern void ext4_ext_drop_refs(struct ext4_ext_path *);
2740 extern int ext4_ext_check_inode(struct inode *inode);
2741 extern int ext4_find_delalloc_range(struct inode *inode,
2742                                     ext4_lblk_t lblk_start,
2743                                     ext4_lblk_t lblk_end);
2744 extern int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk);
2745 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
2746                         __u64 start, __u64 len);
2747 extern int ext4_ext_precache(struct inode *inode);
2748
2749 /* move_extent.c */
2750 extern void ext4_double_down_write_data_sem(struct inode *first,
2751                                             struct inode *second);
2752 extern void ext4_double_up_write_data_sem(struct inode *orig_inode,
2753                                           struct inode *donor_inode);
2754 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
2755                              __u64 start_orig, __u64 start_donor,
2756                              __u64 len, __u64 *moved_len);
2757
2758 /* page-io.c */
2759 extern int __init ext4_init_pageio(void);
2760 extern void ext4_exit_pageio(void);
2761 extern ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags);
2762 extern ext4_io_end_t *ext4_get_io_end(ext4_io_end_t *io_end);
2763 extern int ext4_put_io_end(ext4_io_end_t *io_end);
2764 extern void ext4_put_io_end_defer(ext4_io_end_t *io_end);
2765 extern void ext4_io_submit_init(struct ext4_io_submit *io,
2766                                 struct writeback_control *wbc);
2767 extern void ext4_end_io_rsv_work(struct work_struct *work);
2768 extern void ext4_io_submit(struct ext4_io_submit *io);
2769 extern int ext4_bio_write_page(struct ext4_io_submit *io,
2770                                struct page *page,
2771                                int len,
2772                                struct writeback_control *wbc);
2773
2774 /* mmp.c */
2775 extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
2776 extern void ext4_mmp_csum_set(struct super_block *sb, struct mmp_struct *mmp);
2777 extern int ext4_mmp_csum_verify(struct super_block *sb,
2778                                 struct mmp_struct *mmp);
2779
2780 /*
2781  * Note that these flags will never ever appear in a buffer_head's state flag.
2782  * See EXT4_MAP_... to see where this is used.
2783  */
2784 enum ext4_state_bits {
2785         BH_Uninit       /* blocks are allocated but uninitialized on disk */
2786          = BH_JBDPrivateStart,
2787         BH_AllocFromCluster,    /* allocated blocks were part of already
2788                                  * allocated cluster. */
2789 };
2790
2791 /*
2792  * Add new method to test whether block and inode bitmaps are properly
2793  * initialized. With uninit_bg reading the block from disk is not enough
2794  * to mark the bitmap uptodate. We need to also zero-out the bitmap
2795  */
2796 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
2797
2798 static inline int bitmap_uptodate(struct buffer_head *bh)
2799 {
2800         return (buffer_uptodate(bh) &&
2801                         test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
2802 }
2803 static inline void set_bitmap_uptodate(struct buffer_head *bh)
2804 {
2805         set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
2806 }
2807
2808 /*
2809  * Disable DIO read nolock optimization, so new dioreaders will be forced
2810  * to grab i_mutex
2811  */
2812 static inline void ext4_inode_block_unlocked_dio(struct inode *inode)
2813 {
2814         ext4_set_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
2815         smp_mb();
2816 }
2817 static inline void ext4_inode_resume_unlocked_dio(struct inode *inode)
2818 {
2819         smp_mb();
2820         ext4_clear_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
2821 }
2822
2823 #define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
2824
2825 /* For ioend & aio unwritten conversion wait queues */
2826 #define EXT4_WQ_HASH_SZ         37
2827 #define ext4_ioend_wq(v)   (&ext4__ioend_wq[((unsigned long)(v)) %\
2828                                             EXT4_WQ_HASH_SZ])
2829 #define ext4_aio_mutex(v)  (&ext4__aio_mutex[((unsigned long)(v)) %\
2830                                              EXT4_WQ_HASH_SZ])
2831 extern wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
2832 extern struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
2833
2834 #define EXT4_RESIZING   0
2835 extern int ext4_resize_begin(struct super_block *sb);
2836 extern void ext4_resize_end(struct super_block *sb);
2837
2838 #endif  /* __KERNEL__ */
2839
2840 #endif  /* _EXT4_H */