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 #ifdef __KERNEL__
  33 #include <linux/compat.h>
  34 #endif
  35
  36 /*
  37  * The fourth extended filesystem constants/structures
  38  */
  39
  40 /*
  41  * Define EXT4FS_DEBUG to produce debug messages
  42  */
  43 #undef EXT4FS_DEBUG
  44
  45 /*
  46  * Debug code
  47  */
  48 #ifdef EXT4FS_DEBUG
  49 #define ext4_debug(f, a...)                                             \
  50         do {                                                            \
  51                 printk(KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:",        \
  52                         __FILE__, __LINE__, __func__);                  \
  53                 printk(KERN_DEBUG f, ## a);                             \
  54         } while (0)
  55 #else
  56 #define ext4_debug(f, a...)     do {} while (0)
  57 #endif
  58
  59 #define EXT4_ERROR_INODE(inode, fmt, a...) \
  60         ext4_error_inode((inode), __func__, __LINE__, 0, (fmt), ## a)
  61
  62 #define EXT4_ERROR_INODE_BLOCK(inode, block, fmt, a...)                 \
  63         ext4_error_inode((inode), __func__, __LINE__, (block), (fmt), ## a)
  64
  65 #define EXT4_ERROR_FILE(file, fmt, a...)        \
  66         ext4_error_file(__func__, __LINE__, (file), (fmt), ## a)
  67
  68 /* data type for block offset of block group */
  69 typedef int ext4_grpblk_t;
  70
  71 /* data type for filesystem-wide blocks number */
  72 typedef unsigned long long ext4_fsblk_t;
  73
  74 /* data type for file logical block number */
  75 typedef __u32 ext4_lblk_t;
  76
  77 /* data type for block group number */
  78 typedef unsigned int ext4_group_t;
  79
  80 /*
  81  * Flags used in mballoc's allocation_context flags field.
  82  *
  83  * Also used to show what's going on for debugging purposes when the
  84  * flag field is exported via the traceport interface
  85  */
  86
  87 /* prefer goal again. length */
  88 #define EXT4_MB_HINT_MERGE              0x0001
  89 /* blocks already reserved */
  90 #define EXT4_MB_HINT_RESERVED           0x0002
  91 /* metadata is being allocated */
  92 #define EXT4_MB_HINT_METADATA           0x0004
  93 /* first blocks in the file */
  94 #define EXT4_MB_HINT_FIRST              0x0008
  95 /* search for the best chunk */
  96 #define EXT4_MB_HINT_BEST               0x0010
  97 /* data is being allocated */
  98 #define EXT4_MB_HINT_DATA               0x0020
  99 /* don't preallocate (for tails) */
 100 #define EXT4_MB_HINT_NOPREALLOC         0x0040
 101 /* allocate for locality group */
 102 #define EXT4_MB_HINT_GROUP_ALLOC        0x0080
 103 /* allocate goal blocks or none */
 104 #define EXT4_MB_HINT_GOAL_ONLY          0x0100
 105 /* goal is meaningful */
 106 #define EXT4_MB_HINT_TRY_GOAL           0x0200
 107 /* blocks already pre-reserved by delayed allocation */
 108 #define EXT4_MB_DELALLOC_RESERVED       0x0400
 109 /* We are doing stream allocation */
 110 #define EXT4_MB_STREAM_ALLOC            0x0800
 111
 112
 113 struct ext4_allocation_request {
 114         /* target inode for block we're allocating */
 115         struct inode *inode;
 116         /* how many blocks we want to allocate */
 117         unsigned int len;
 118         /* logical block in target inode */
 119         ext4_lblk_t logical;
 120         /* the closest logical allocated block to the left */
 121         ext4_lblk_t lleft;
 122         /* the closest logical allocated block to the right */
 123         ext4_lblk_t lright;
 124         /* phys. target (a hint) */
 125         ext4_fsblk_t goal;
 126         /* phys. block for the closest logical allocated block to the left */
 127         ext4_fsblk_t pleft;
 128         /* phys. block for the closest logical allocated block to the right */
 129         ext4_fsblk_t pright;
 130         /* flags. see above EXT4_MB_HINT_* */
 131         unsigned int flags;
 132 };
 133
 134 /*
 135  * Logical to physical block mapping, used by ext4_map_blocks()
 136  *
 137  * This structure is used to pass requests into ext4_map_blocks() as
 138  * well as to store the information returned by ext4_map_blocks().  It
 139  * takes less room on the stack than a struct buffer_head.
 140  */
 141 #define EXT4_MAP_NEW            (1 << BH_New)
 142 #define EXT4_MAP_MAPPED         (1 << BH_Mapped)
 143 #define EXT4_MAP_UNWRITTEN      (1 << BH_Unwritten)
 144 #define EXT4_MAP_BOUNDARY       (1 << BH_Boundary)
 145 #define EXT4_MAP_UNINIT         (1 << BH_Uninit)
 146 #define EXT4_MAP_FLAGS          (EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
 147                                  EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY |\
 148                                  EXT4_MAP_UNINIT)
 149
 150 struct ext4_map_blocks {
 151         ext4_fsblk_t m_pblk;
 152         ext4_lblk_t m_lblk;
 153         unsigned int m_len;
 154         unsigned int m_flags;
 155 };
 156
 157 /*
 158  * For delayed allocation tracking
 159  */
 160 struct mpage_da_data {
 161         struct inode *inode;
 162         sector_t b_blocknr;             /* start block number of extent */
 163         size_t b_size;                  /* size of extent */
 164         unsigned long b_state;          /* state of the extent */
 165         unsigned long first_page, next_page;    /* extent of pages */
 166         struct writeback_control *wbc;
 167         int io_done;
 168         int pages_written;
 169         int retval;
 170 };
 171 #define EXT4_IO_UNWRITTEN       0x1
 172 typedef struct ext4_io_end {
 173         struct list_head        list;           /* per-file finished IO list */
 174         struct inode            *inode;         /* file being written to */
 175         unsigned int            flag;           /* unwritten or not */
 176         struct page             *page;          /* page struct for buffer write */
 177         loff_t                  offset;         /* offset in the file */
 178         ssize_t                 size;           /* size of the extent */
 179         struct work_struct      work;           /* data work queue */
 180         struct kiocb            *iocb;          /* iocb struct for AIO */
 181         int                     result;         /* error value for AIO */
 182 } ext4_io_end_t;
 183
 184 /*
 185  * Special inodes numbers
 186  */
 187 #define EXT4_BAD_INO             1      /* Bad blocks inode */
 188 #define EXT4_ROOT_INO            2      /* Root inode */
 189 #define EXT4_BOOT_LOADER_INO     5      /* Boot loader inode */
 190 #define EXT4_UNDEL_DIR_INO       6      /* Undelete directory inode */
 191 #define EXT4_RESIZE_INO          7      /* Reserved group descriptors inode */
 192 #define EXT4_JOURNAL_INO         8      /* Journal inode */
 193
 194 /* First non-reserved inode for old ext4 filesystems */
 195 #define EXT4_GOOD_OLD_FIRST_INO 11
 196
 197 /*
 198  * Maximal count of links to a file
 199  */
 200 #define EXT4_LINK_MAX           65000
 201
 202 /*
 203  * Macro-instructions used to manage several block sizes
 204  */
 205 #define EXT4_MIN_BLOCK_SIZE             1024
 206 #define EXT4_MAX_BLOCK_SIZE             65536
 207 #define EXT4_MIN_BLOCK_LOG_SIZE         10
 208 #define EXT4_MAX_BLOCK_LOG_SIZE         16
 209 #ifdef __KERNEL__
 210 # define EXT4_BLOCK_SIZE(s)             ((s)->s_blocksize)
 211 #else
 212 # define EXT4_BLOCK_SIZE(s)             (EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
 213 #endif
 214 #define EXT4_ADDR_PER_BLOCK(s)          (EXT4_BLOCK_SIZE(s) / sizeof(__u32))
 215 #ifdef __KERNEL__
 216 # define EXT4_BLOCK_SIZE_BITS(s)        ((s)->s_blocksize_bits)
 217 #else
 218 # define EXT4_BLOCK_SIZE_BITS(s)        ((s)->s_log_block_size + 10)
 219 #endif
 220 #ifdef __KERNEL__
 221 #define EXT4_ADDR_PER_BLOCK_BITS(s)     (EXT4_SB(s)->s_addr_per_block_bits)
 222 #define EXT4_INODE_SIZE(s)              (EXT4_SB(s)->s_inode_size)
 223 #define EXT4_FIRST_INO(s)               (EXT4_SB(s)->s_first_ino)
 224 #else
 225 #define EXT4_INODE_SIZE(s)      (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
 226                                  EXT4_GOOD_OLD_INODE_SIZE : \
 227                                  (s)->s_inode_size)
 228 #define EXT4_FIRST_INO(s)       (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
 229                                  EXT4_GOOD_OLD_FIRST_INO : \
 230                                  (s)->s_first_ino)
 231 #endif
 232 #define EXT4_BLOCK_ALIGN(size, blkbits)         ALIGN((size), (1 << (blkbits)))
 233
 234 /*
 235  * Structure of a blocks group descriptor
 236  */
 237 struct ext4_group_desc
 238 {
 239         __le32  bg_block_bitmap_lo;     /* Blocks bitmap block */
 240         __le32  bg_inode_bitmap_lo;     /* Inodes bitmap block */
 241         __le32  bg_inode_table_lo;      /* Inodes table block */
 242         __le16  bg_free_blocks_count_lo;/* Free blocks count */
 243         __le16  bg_free_inodes_count_lo;/* Free inodes count */
 244         __le16  bg_used_dirs_count_lo;  /* Directories count */
 245         __le16  bg_flags;               /* EXT4_BG_flags (INODE_UNINIT, etc) */
 246         __u32   bg_reserved[2];         /* Likely block/inode bitmap checksum */
 247         __le16  bg_itable_unused_lo;    /* Unused inodes count */
 248         __le16  bg_checksum;            /* crc16(sb_uuid+group+desc) */
 249         __le32  bg_block_bitmap_hi;     /* Blocks bitmap block MSB */
 250         __le32  bg_inode_bitmap_hi;     /* Inodes bitmap block MSB */
 251         __le32  bg_inode_table_hi;      /* Inodes table block MSB */
 252         __le16  bg_free_blocks_count_hi;/* Free blocks count MSB */
 253         __le16  bg_free_inodes_count_hi;/* Free inodes count MSB */
 254         __le16  bg_used_dirs_count_hi;  /* Directories count MSB */
 255         __le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
 256         __u32   bg_reserved2[3];
 257 };
 258
 259 /*
 260  * Structure of a flex block group info
 261  */
 262
 263 struct flex_groups {
 264         atomic_t free_inodes;
 265         atomic_t free_blocks;
 266         atomic_t used_dirs;
 267 };
 268
 269 #define EXT4_BG_INODE_UNINIT    0x0001 /* Inode table/bitmap not in use */
 270 #define EXT4_BG_BLOCK_UNINIT    0x0002 /* Block bitmap not in use */
 271 #define EXT4_BG_INODE_ZEROED    0x0004 /* On-disk itable initialized to zero */
 272
 273 /*
 274  * Macro-instructions used to manage group descriptors
 275  */
 276 #define EXT4_MIN_DESC_SIZE              32
 277 #define EXT4_MIN_DESC_SIZE_64BIT        64
 278 #define EXT4_MAX_DESC_SIZE              EXT4_MIN_BLOCK_SIZE
 279 #define EXT4_DESC_SIZE(s)               (EXT4_SB(s)->s_desc_size)
 280 #ifdef __KERNEL__
 281 # define EXT4_BLOCKS_PER_GROUP(s)       (EXT4_SB(s)->s_blocks_per_group)
 282 # define EXT4_DESC_PER_BLOCK(s)         (EXT4_SB(s)->s_desc_per_block)
 283 # define EXT4_INODES_PER_GROUP(s)       (EXT4_SB(s)->s_inodes_per_group)
 284 # define EXT4_DESC_PER_BLOCK_BITS(s)    (EXT4_SB(s)->s_desc_per_block_bits)
 285 #else
 286 # define EXT4_BLOCKS_PER_GROUP(s)       ((s)->s_blocks_per_group)
 287 # define EXT4_DESC_PER_BLOCK(s)         (EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
 288 # define EXT4_INODES_PER_GROUP(s)       ((s)->s_inodes_per_group)
 289 #endif
 290
 291 /*
 292  * Constants relative to the data blocks
 293  */
 294 #define EXT4_NDIR_BLOCKS                12
 295 #define EXT4_IND_BLOCK                  EXT4_NDIR_BLOCKS
 296 #define EXT4_DIND_BLOCK                 (EXT4_IND_BLOCK + 1)
 297 #define EXT4_TIND_BLOCK                 (EXT4_DIND_BLOCK + 1)
 298 #define EXT4_N_BLOCKS                   (EXT4_TIND_BLOCK + 1)
 299
 300 /*
 301  * Inode flags
 302  */
 303 #define EXT4_SECRM_FL                   0x00000001 /* Secure deletion */
 304 #define EXT4_UNRM_FL                    0x00000002 /* Undelete */
 305 #define EXT4_COMPR_FL                   0x00000004 /* Compress file */
 306 #define EXT4_SYNC_FL                    0x00000008 /* Synchronous updates */
 307 #define EXT4_IMMUTABLE_FL               0x00000010 /* Immutable file */
 308 #define EXT4_APPEND_FL                  0x00000020 /* writes to file may only append */
 309 #define EXT4_NODUMP_FL                  0x00000040 /* do not dump file */
 310 #define EXT4_NOATIME_FL                 0x00000080 /* do not update atime */
 311 /* Reserved for compression usage... */
 312 #define EXT4_DIRTY_FL                   0x00000100
 313 #define EXT4_COMPRBLK_FL                0x00000200 /* One or more compressed clusters */
 314 #define EXT4_NOCOMPR_FL                 0x00000400 /* Don't compress */
 315 #define EXT4_ECOMPR_FL                  0x00000800 /* Compression error */
 316 /* End compression flags --- maybe not all used */
 317 #define EXT4_INDEX_FL                   0x00001000 /* hash-indexed directory */
 318 #define EXT4_IMAGIC_FL                  0x00002000 /* AFS directory */
 319 #define EXT4_JOURNAL_DATA_FL            0x00004000 /* file data should be journaled */
 320 #define EXT4_NOTAIL_FL                  0x00008000 /* file tail should not be merged */
 321 #define EXT4_DIRSYNC_FL                 0x00010000 /* dirsync behaviour (directories only) */
 322 #define EXT4_TOPDIR_FL                  0x00020000 /* Top of directory hierarchies*/
 323 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
 324 #define EXT4_EXTENTS_FL                 0x00080000 /* Inode uses extents */
 325 #define EXT4_EA_INODE_FL                0x00200000 /* Inode used for large EA */
 326 #define EXT4_EOFBLOCKS_FL               0x00400000 /* Blocks allocated beyond EOF */
 327 #define EXT4_RESERVED_FL                0x80000000 /* reserved for ext4 lib */
 328
 329 #define EXT4_FL_USER_VISIBLE            0x004BDFFF /* User visible flags */
 330 #define EXT4_FL_USER_MODIFIABLE         0x004B80FF /* User modifiable flags */
 331
 332 /* Flags that should be inherited by new inodes from their parent. */
 333 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
 334                            EXT4_SYNC_FL | EXT4_IMMUTABLE_FL | EXT4_APPEND_FL |\
 335                            EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
 336                            EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
 337                            EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
 338
 339 /* Flags that are appropriate for regular files (all but dir-specific ones). */
 340 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
 341
 342 /* Flags that are appropriate for non-directories/regular files. */
 343 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
 344
 345 /* Mask out flags that are inappropriate for the given type of inode. */
 346 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
 347 {
 348         if (S_ISDIR(mode))
 349                 return flags;
 350         else if (S_ISREG(mode))
 351                 return flags & EXT4_REG_FLMASK;
 352         else
 353                 return flags & EXT4_OTHER_FLMASK;
 354 }
 355
 356 /*
 357  * Inode flags used for atomic set/get
 358  */
 359 enum {
 360         EXT4_INODE_SECRM        = 0,    /* Secure deletion */
 361         EXT4_INODE_UNRM         = 1,    /* Undelete */
 362         EXT4_INODE_COMPR        = 2,    /* Compress file */
 363         EXT4_INODE_SYNC         = 3,    /* Synchronous updates */
 364         EXT4_INODE_IMMUTABLE    = 4,    /* Immutable file */
 365         EXT4_INODE_APPEND       = 5,    /* writes to file may only append */
 366         EXT4_INODE_NODUMP       = 6,    /* do not dump file */
 367         EXT4_INODE_NOATIME      = 7,    /* do not update atime */
 368 /* Reserved for compression usage... */
 369         EXT4_INODE_DIRTY        = 8,
 370         EXT4_INODE_COMPRBLK     = 9,    /* One or more compressed clusters */
 371         EXT4_INODE_NOCOMPR      = 10,   /* Don't compress */
 372         EXT4_INODE_ECOMPR       = 11,   /* Compression error */
 373 /* End compression flags --- maybe not all used */
 374         EXT4_INODE_INDEX        = 12,   /* hash-indexed directory */
 375         EXT4_INODE_IMAGIC       = 13,   /* AFS directory */
 376         EXT4_INODE_JOURNAL_DATA = 14,   /* file data should be journaled */
 377         EXT4_INODE_NOTAIL       = 15,   /* file tail should not be merged */
 378         EXT4_INODE_DIRSYNC      = 16,   /* dirsync behaviour (directories only) */
 379         EXT4_INODE_TOPDIR       = 17,   /* Top of directory hierarchies*/
 380         EXT4_INODE_HUGE_FILE    = 18,   /* Set to each huge file */
 381         EXT4_INODE_EXTENTS      = 19,   /* Inode uses extents */
 382         EXT4_INODE_EA_INODE     = 21,   /* Inode used for large EA */
 383         EXT4_INODE_EOFBLOCKS    = 22,   /* Blocks allocated beyond EOF */
 384         EXT4_INODE_RESERVED     = 31,   /* reserved for ext4 lib */
 385 };
 386
 387 #define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1 << EXT4_INODE_##FLAG))
 388 #define CHECK_FLAG_VALUE(FLAG) if (!TEST_FLAG_VALUE(FLAG)) { \
 389         printk(KERN_EMERG "EXT4 flag fail: " #FLAG ": %d %d\n", \
 390                 EXT4_##FLAG##_FL, EXT4_INODE_##FLAG); BUG_ON(1); }
 391
 392 /*
 393  * Since it's pretty easy to mix up bit numbers and hex values, and we
 394  * can't do a compile-time test for ENUM values, we use a run-time
 395  * test to make sure that EXT4_XXX_FL is consistent with respect to
 396  * EXT4_INODE_XXX.  If all is well the printk and BUG_ON will all drop
 397  * out so it won't cost any extra space in the compiled kernel image.
 398  * But it's important that these values are the same, since we are
 399  * using EXT4_INODE_XXX to test for the flag values, but EXT4_XX_FL
 400  * must be consistent with the values of FS_XXX_FL defined in
 401  * include/linux/fs.h and the on-disk values found in ext2, ext3, and
 402  * ext4 filesystems, and of course the values defined in e2fsprogs.
 403  *
 404  * It's not paranoia if the Murphy's Law really *is* out to get you.  :-)
 405  */
 406 static inline void ext4_check_flag_values(void)
 407 {
 408         CHECK_FLAG_VALUE(SECRM);
 409         CHECK_FLAG_VALUE(UNRM);
 410         CHECK_FLAG_VALUE(COMPR);
 411         CHECK_FLAG_VALUE(SYNC);
 412         CHECK_FLAG_VALUE(IMMUTABLE);
 413         CHECK_FLAG_VALUE(APPEND);
 414         CHECK_FLAG_VALUE(NODUMP);
 415         CHECK_FLAG_VALUE(NOATIME);
 416         CHECK_FLAG_VALUE(DIRTY);
 417         CHECK_FLAG_VALUE(COMPRBLK);
 418         CHECK_FLAG_VALUE(NOCOMPR);
 419         CHECK_FLAG_VALUE(ECOMPR);
 420         CHECK_FLAG_VALUE(INDEX);
 421         CHECK_FLAG_VALUE(IMAGIC);
 422         CHECK_FLAG_VALUE(JOURNAL_DATA);
 423         CHECK_FLAG_VALUE(NOTAIL);
 424         CHECK_FLAG_VALUE(DIRSYNC);
 425         CHECK_FLAG_VALUE(TOPDIR);
 426         CHECK_FLAG_VALUE(HUGE_FILE);
 427         CHECK_FLAG_VALUE(EXTENTS);
 428         CHECK_FLAG_VALUE(EA_INODE);
 429         CHECK_FLAG_VALUE(EOFBLOCKS);
 430         CHECK_FLAG_VALUE(RESERVED);
 431 }
 432
 433 /* Used to pass group descriptor data when online resize is done */
 434 struct ext4_new_group_input {
 435         __u32 group;            /* Group number for this data */
 436         __u64 block_bitmap;     /* Absolute block number of block bitmap */
 437         __u64 inode_bitmap;     /* Absolute block number of inode bitmap */
 438         __u64 inode_table;      /* Absolute block number of inode table start */
 439         __u32 blocks_count;     /* Total number of blocks in this group */
 440         __u16 reserved_blocks;  /* Number of reserved blocks in this group */
 441         __u16 unused;
 442 };
 443
 444 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
 445 struct compat_ext4_new_group_input {
 446         u32 group;
 447         compat_u64 block_bitmap;
 448         compat_u64 inode_bitmap;
 449         compat_u64 inode_table;
 450         u32 blocks_count;
 451         u16 reserved_blocks;
 452         u16 unused;
 453 };
 454 #endif
 455
 456 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
 457 struct ext4_new_group_data {
 458         __u32 group;
 459         __u64 block_bitmap;
 460         __u64 inode_bitmap;
 461         __u64 inode_table;
 462         __u32 blocks_count;
 463         __u16 reserved_blocks;
 464         __u16 unused;
 465         __u32 free_blocks_count;
 466 };
 467
 468 /*
 469  * Flags used by ext4_map_blocks()
 470  */
 471         /* Allocate any needed blocks and/or convert an unitialized
 472            extent to be an initialized ext4 */
 473 #define EXT4_GET_BLOCKS_CREATE                  0x0001
 474         /* Request the creation of an unitialized extent */
 475 #define EXT4_GET_BLOCKS_UNINIT_EXT              0x0002
 476 #define EXT4_GET_BLOCKS_CREATE_UNINIT_EXT       (EXT4_GET_BLOCKS_UNINIT_EXT|\
 477                                                  EXT4_GET_BLOCKS_CREATE)
 478         /* Caller is from the delayed allocation writeout path,
 479            so set the magic i_delalloc_reserve_flag after taking the
 480            inode allocation semaphore for */
 481 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE        0x0004
 482         /* caller is from the direct IO path, request to creation of an
 483         unitialized extents if not allocated, split the uninitialized
 484         extent if blocks has been preallocated already*/
 485 #define EXT4_GET_BLOCKS_PRE_IO                  0x0008
 486 #define EXT4_GET_BLOCKS_CONVERT                 0x0010
 487 #define EXT4_GET_BLOCKS_IO_CREATE_EXT           (EXT4_GET_BLOCKS_PRE_IO|\
 488                                          EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
 489         /* Convert extent to initialized after IO complete */
 490 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT          (EXT4_GET_BLOCKS_CONVERT|\
 491                                          EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
 492
 493 /*
 494  * Flags used by ext4_free_blocks
 495  */
 496 #define EXT4_FREE_BLOCKS_METADATA       0x0001
 497 #define EXT4_FREE_BLOCKS_FORGET         0x0002
 498 #define EXT4_FREE_BLOCKS_VALIDATED      0x0004
 499
 500 /*
 501  * ioctl commands
 502  */
 503 #define EXT4_IOC_GETFLAGS               FS_IOC_GETFLAGS
 504 #define EXT4_IOC_SETFLAGS               FS_IOC_SETFLAGS
 505 #define EXT4_IOC_GETVERSION             _IOR('f', 3, long)
 506 #define EXT4_IOC_SETVERSION             _IOW('f', 4, long)
 507 #define EXT4_IOC_GETVERSION_OLD         FS_IOC_GETVERSION
 508 #define EXT4_IOC_SETVERSION_OLD         FS_IOC_SETVERSION
 509 #ifdef CONFIG_JBD2_DEBUG
 510 #define EXT4_IOC_WAIT_FOR_READONLY      _IOR('f', 99, long)
 511 #endif
 512 #define EXT4_IOC_GETRSVSZ               _IOR('f', 5, long)
 513 #define EXT4_IOC_SETRSVSZ               _IOW('f', 6, long)
 514 #define EXT4_IOC_GROUP_EXTEND           _IOW('f', 7, unsigned long)
 515 #define EXT4_IOC_GROUP_ADD              _IOW('f', 8, struct ext4_new_group_input)
 516 #define EXT4_IOC_MIGRATE                _IO('f', 9)
 517  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
 518  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
 519 #define EXT4_IOC_ALLOC_DA_BLKS          _IO('f', 12)
 520 #define EXT4_IOC_MOVE_EXT               _IOWR('f', 15, struct move_extent)
 521
 522 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
 523 /*
 524  * ioctl commands in 32 bit emulation
 525  */
 526 #define EXT4_IOC32_GETFLAGS             FS_IOC32_GETFLAGS
 527 #define EXT4_IOC32_SETFLAGS             FS_IOC32_SETFLAGS
 528 #define EXT4_IOC32_GETVERSION           _IOR('f', 3, int)
 529 #define EXT4_IOC32_SETVERSION           _IOW('f', 4, int)
 530 #define EXT4_IOC32_GETRSVSZ             _IOR('f', 5, int)
 531 #define EXT4_IOC32_SETRSVSZ             _IOW('f', 6, int)
 532 #define EXT4_IOC32_GROUP_EXTEND         _IOW('f', 7, unsigned int)
 533 #define EXT4_IOC32_GROUP_ADD            _IOW('f', 8, struct compat_ext4_new_group_input)
 534 #ifdef CONFIG_JBD2_DEBUG
 535 #define EXT4_IOC32_WAIT_FOR_READONLY    _IOR('f', 99, int)
 536 #endif
 537 #define EXT4_IOC32_GETVERSION_OLD       FS_IOC32_GETVERSION
 538 #define EXT4_IOC32_SETVERSION_OLD       FS_IOC32_SETVERSION
 539 #endif
 540
 541
 542 /*
 543  *  Mount options
 544  */
 545 struct ext4_mount_options {
 546         unsigned long s_mount_opt;
 547         uid_t s_resuid;
 548         gid_t s_resgid;
 549         unsigned long s_commit_interval;
 550         u32 s_min_batch_time, s_max_batch_time;
 551 #ifdef CONFIG_QUOTA
 552         int s_jquota_fmt;
 553         char *s_qf_names[MAXQUOTAS];
 554 #endif
 555 };
 556
 557 /* Max physical block we can addres w/o extents */
 558 #define EXT4_MAX_BLOCK_FILE_PHYS        0xFFFFFFFF
 559
 560 /*
 561  * Structure of an inode on the disk
 562  */
 563 struct ext4_inode {
 564         __le16  i_mode;         /* File mode */
 565         __le16  i_uid;          /* Low 16 bits of Owner Uid */
 566         __le32  i_size_lo;      /* Size in bytes */
 567         __le32  i_atime;        /* Access time */
 568         __le32  i_ctime;        /* Inode Change time */
 569         __le32  i_mtime;        /* Modification time */
 570         __le32  i_dtime;        /* Deletion Time */
 571         __le16  i_gid;          /* Low 16 bits of Group Id */
 572         __le16  i_links_count;  /* Links count */
 573         __le32  i_blocks_lo;    /* Blocks count */
 574         __le32  i_flags;        /* File flags */
 575         union {
 576                 struct {
 577                         __le32  l_i_version;
 578                 } linux1;
 579                 struct {
 580                         __u32  h_i_translator;
 581                 } hurd1;
 582                 struct {
 583                         __u32  m_i_reserved1;
 584                 } masix1;
 585         } osd1;                         /* OS dependent 1 */
 586         __le32  i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
 587         __le32  i_generation;   /* File version (for NFS) */
 588         __le32  i_file_acl_lo;  /* File ACL */
 589         __le32  i_size_high;
 590         __le32  i_obso_faddr;   /* Obsoleted fragment address */
 591         union {
 592                 struct {
 593                         __le16  l_i_blocks_high; /* were l_i_reserved1 */
 594                         __le16  l_i_file_acl_high;
 595                         __le16  l_i_uid_high;   /* these 2 fields */
 596                         __le16  l_i_gid_high;   /* were reserved2[0] */
 597                         __u32   l_i_reserved2;
 598                 } linux2;
 599                 struct {
 600                         __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
 601                         __u16   h_i_mode_high;
 602                         __u16   h_i_uid_high;
 603                         __u16   h_i_gid_high;
 604                         __u32   h_i_author;
 605                 } hurd2;
 606                 struct {
 607                         __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
 608                         __le16  m_i_file_acl_high;
 609                         __u32   m_i_reserved2[2];
 610                 } masix2;
 611         } osd2;                         /* OS dependent 2 */
 612         __le16  i_extra_isize;
 613         __le16  i_pad1;
 614         __le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
 615         __le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
 616         __le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
 617         __le32  i_crtime;       /* File Creation time */
 618         __le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
 619         __le32  i_version_hi;   /* high 32 bits for 64-bit version */
 620 };
 621
 622 struct move_extent {
 623         __u32 reserved;         /* should be zero */
 624         __u32 donor_fd;         /* donor file descriptor */
 625         __u64 orig_start;       /* logical start offset in block for orig */
 626         __u64 donor_start;      /* logical start offset in block for donor */
 627         __u64 len;              /* block length to be moved */
 628         __u64 moved_len;        /* moved block length */
 629 };
 630
 631 #define EXT4_EPOCH_BITS 2
 632 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
 633 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
 634
 635 /*
 636  * Extended fields will fit into an inode if the filesystem was formatted
 637  * with large inodes (-I 256 or larger) and there are not currently any EAs
 638  * consuming all of the available space. For new inodes we always reserve
 639  * enough space for the kernel's known extended fields, but for inodes
 640  * created with an old kernel this might not have been the case. None of
 641  * the extended inode fields is critical for correct filesystem operation.
 642  * This macro checks if a certain field fits in the inode. Note that
 643  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
 644  */
 645 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)   \
 646         ((offsetof(typeof(*ext4_inode), field) +        \
 647           sizeof((ext4_inode)->field))                  \
 648         <= (EXT4_GOOD_OLD_INODE_SIZE +                  \
 649             (einode)->i_extra_isize))                   \
 650
 651 static inline __le32 ext4_encode_extra_time(struct timespec *time)
 652 {
 653        return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
 654                            (time->tv_sec >> 32) & EXT4_EPOCH_MASK : 0) |
 655                           ((time->tv_nsec << EXT4_EPOCH_BITS) & EXT4_NSEC_MASK));
 656 }
 657
 658 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
 659 {
 660        if (sizeof(time->tv_sec) > 4)
 661                time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
 662                                << 32;
 663        time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
 664 }
 665
 666 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)                          \
 667 do {                                                                           \
 668         (raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);               \
 669         if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
 670                 (raw_inode)->xtime ## _extra =                                 \
 671                                 ext4_encode_extra_time(&(inode)->xtime);       \
 672 } while (0)
 673
 674 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)                        \
 675 do {                                                                           \
 676         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))                      \
 677                 (raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
 678         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))            \
 679                 (raw_inode)->xtime ## _extra =                                 \
 680                                 ext4_encode_extra_time(&(einode)->xtime);      \
 681 } while (0)
 682
 683 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)                          \
 684 do {                                                                           \
 685         (inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
 686         if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
 687                 ext4_decode_extra_time(&(inode)->xtime,                        \
 688                                        raw_inode->xtime ## _extra);            \
 689 } while (0)
 690
 691 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)                        \
 692 do {                                                                           \
 693         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))                      \
 694                 (einode)->xtime.tv_sec =                                       \
 695                         (signed)le32_to_cpu((raw_inode)->xtime);               \
 696         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))            \
 697                 ext4_decode_extra_time(&(einode)->xtime,                       \
 698                                        raw_inode->xtime ## _extra);            \
 699 } while (0)
 700
 701 #define i_disk_version osd1.linux1.l_i_version
 702
 703 #if defined(__KERNEL__) || defined(__linux__)
 704 #define i_reserved1     osd1.linux1.l_i_reserved1
 705 #define i_file_acl_high osd2.linux2.l_i_file_acl_high
 706 #define i_blocks_high   osd2.linux2.l_i_blocks_high
 707 #define i_uid_low       i_uid
 708 #define i_gid_low       i_gid
 709 #define i_uid_high      osd2.linux2.l_i_uid_high
 710 #define i_gid_high      osd2.linux2.l_i_gid_high
 711 #define i_reserved2     osd2.linux2.l_i_reserved2
 712
 713 #elif defined(__GNU__)
 714
 715 #define i_translator    osd1.hurd1.h_i_translator
 716 #define i_uid_high      osd2.hurd2.h_i_uid_high
 717 #define i_gid_high      osd2.hurd2.h_i_gid_high
 718 #define i_author        osd2.hurd2.h_i_author
 719
 720 #elif defined(__masix__)
 721
 722 #define i_reserved1     osd1.masix1.m_i_reserved1
 723 #define i_file_acl_high osd2.masix2.m_i_file_acl_high
 724 #define i_reserved2     osd2.masix2.m_i_reserved2
 725
 726 #endif /* defined(__KERNEL__) || defined(__linux__) */
 727
 728 /*
 729  * storage for cached extent
 730  */
 731 struct ext4_ext_cache {
 732         ext4_fsblk_t    ec_start;
 733         ext4_lblk_t     ec_block;
 734         __u32           ec_len; /* must be 32bit to return holes */
 735         __u32           ec_type;
 736 };
 737
 738 /*
 739  * fourth extended file system inode data in memory
 740  */
 741 struct ext4_inode_info {
 742         __le32  i_data[15];     /* unconverted */
 743         __u32   i_dtime;
 744         ext4_fsblk_t    i_file_acl;
 745
 746         /*
 747          * i_block_group is the number of the block group which contains
 748          * this file's inode.  Constant across the lifetime of the inode,
 749          * it is ued for making block allocation decisions - we try to
 750          * place a file's data blocks near its inode block, and new inodes
 751          * near to their parent directory's inode.
 752          */
 753         ext4_group_t    i_block_group;
 754         unsigned long   i_state_flags;          /* Dynamic state flags */
 755         unsigned long   i_flags;
 756
 757         ext4_lblk_t             i_dir_start_lookup;
 758 #ifdef CONFIG_EXT4_FS_XATTR
 759         /*
 760          * Extended attributes can be read independently of the main file
 761          * data. Taking i_mutex even when reading would cause contention
 762          * between readers of EAs and writers of regular file data, so
 763          * instead we synchronize on xattr_sem when reading or changing
 764          * EAs.
 765          */
 766         struct rw_semaphore xattr_sem;
 767 #endif
 768
 769         struct list_head i_orphan;      /* unlinked but open inodes */
 770
 771         /*
 772          * i_disksize keeps track of what the inode size is ON DISK, not
 773          * in memory.  During truncate, i_size is set to the new size by
 774          * the VFS prior to calling ext4_truncate(), but the filesystem won't
 775          * set i_disksize to 0 until the truncate is actually under way.
 776          *
 777          * The intent is that i_disksize always represents the blocks which
 778          * are used by this file.  This allows recovery to restart truncate
 779          * on orphans if we crash during truncate.  We actually write i_disksize
 780          * into the on-disk inode when writing inodes out, instead of i_size.
 781          *
 782          * The only time when i_disksize and i_size may be different is when
 783          * a truncate is in progress.  The only things which change i_disksize
 784          * are ext4_get_block (growth) and ext4_truncate (shrinkth).
 785          */
 786         loff_t  i_disksize;
 787
 788         /*
 789          * i_data_sem is for serialising ext4_truncate() against
 790          * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
 791          * data tree are chopped off during truncate. We can't do that in
 792          * ext4 because whenever we perform intermediate commits during
 793          * truncate, the inode and all the metadata blocks *must* be in a
 794          * consistent state which allows truncation of the orphans to restart
 795          * during recovery.  Hence we must fix the get_block-vs-truncate race
 796          * by other means, so we have i_data_sem.
 797          */
 798         struct rw_semaphore i_data_sem;
 799         struct inode vfs_inode;
 800         struct jbd2_inode jinode;
 801
 802         struct ext4_ext_cache i_cached_extent;
 803         /*
 804          * File creation time. Its function is same as that of
 805          * struct timespec i_{a,c,m}time in the generic inode.
 806          */
 807         struct timespec i_crtime;
 808
 809         /* mballoc */
 810         struct list_head i_prealloc_list;
 811         spinlock_t i_prealloc_lock;
 812
 813         /* ialloc */
 814         ext4_group_t    i_last_alloc_group;
 815
 816         /* allocation reservation info for delalloc */
 817         unsigned int i_reserved_data_blocks;
 818         unsigned int i_reserved_meta_blocks;
 819         unsigned int i_allocated_meta_blocks;
 820         unsigned short i_delalloc_reserved_flag;
 821         sector_t i_da_metadata_calc_last_lblock;
 822         int i_da_metadata_calc_len;
 823
 824         /* on-disk additional length */
 825         __u16 i_extra_isize;
 826
 827         spinlock_t i_block_reservation_lock;
 828 #ifdef CONFIG_QUOTA
 829         /* quota space reservation, managed internally by quota code */
 830         qsize_t i_reserved_quota;
 831 #endif
 832
 833         /* completed IOs that might need unwritten extents handling */
 834         struct list_head i_completed_io_list;
 835         spinlock_t i_completed_io_lock;
 836         /* current io_end structure for async DIO write*/
 837         ext4_io_end_t *cur_aio_dio;
 838
 839         /*
 840          * Transactions that contain inode's metadata needed to complete
 841          * fsync and fdatasync, respectively.
 842          */
 843         tid_t i_sync_tid;
 844         tid_t i_datasync_tid;
 845 };
 846
 847 /*
 848  * File system states
 849  */
 850 #define EXT4_VALID_FS                   0x0001  /* Unmounted cleanly */
 851 #define EXT4_ERROR_FS                   0x0002  /* Errors detected */
 852 #define EXT4_ORPHAN_FS                  0x0004  /* Orphans being recovered */
 853
 854 /*
 855  * Misc. filesystem flags
 856  */
 857 #define EXT2_FLAGS_SIGNED_HASH          0x0001  /* Signed dirhash in use */
 858 #define EXT2_FLAGS_UNSIGNED_HASH        0x0002  /* Unsigned dirhash in use */
 859 #define EXT2_FLAGS_TEST_FILESYS         0x0004  /* to test development code */
 860
 861 /*
 862  * Mount flags
 863  */
 864 #define EXT4_MOUNT_OLDALLOC             0x00002  /* Don't use the new Orlov allocator */
 865 #define EXT4_MOUNT_GRPID                0x00004 /* Create files with directory's group */
 866 #define EXT4_MOUNT_DEBUG                0x00008 /* Some debugging messages */
 867 #define EXT4_MOUNT_ERRORS_CONT          0x00010 /* Continue on errors */
 868 #define EXT4_MOUNT_ERRORS_RO            0x00020 /* Remount fs ro on errors */
 869 #define EXT4_MOUNT_ERRORS_PANIC         0x00040 /* Panic on errors */
 870 #define EXT4_MOUNT_MINIX_DF             0x00080 /* Mimics the Minix statfs */
 871 #define EXT4_MOUNT_NOLOAD               0x00100 /* Don't use existing journal*/
 872 #define EXT4_MOUNT_DATA_FLAGS           0x00C00 /* Mode for data writes: */
 873 #define EXT4_MOUNT_JOURNAL_DATA         0x00400 /* Write data to journal */
 874 #define EXT4_MOUNT_ORDERED_DATA         0x00800 /* Flush data before commit */
 875 #define EXT4_MOUNT_WRITEBACK_DATA       0x00C00 /* No data ordering */
 876 #define EXT4_MOUNT_UPDATE_JOURNAL       0x01000 /* Update the journal format */
 877 #define EXT4_MOUNT_NO_UID32             0x02000  /* Disable 32-bit UIDs */
 878 #define EXT4_MOUNT_XATTR_USER           0x04000 /* Extended user attributes */
 879 #define EXT4_MOUNT_POSIX_ACL            0x08000 /* POSIX Access Control Lists */
 880 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC     0x10000 /* No auto delalloc mapping */
 881 #define EXT4_MOUNT_BARRIER              0x20000 /* Use block barriers */
 882 #define EXT4_MOUNT_QUOTA                0x80000 /* Some quota option set */
 883 #define EXT4_MOUNT_USRQUOTA             0x100000 /* "old" user quota */
 884 #define EXT4_MOUNT_GRPQUOTA             0x200000 /* "old" group quota */
 885 #define EXT4_MOUNT_DIOREAD_NOLOCK       0x400000 /* Enable support for dio read nolocking */
 886 #define EXT4_MOUNT_JOURNAL_CHECKSUM     0x800000 /* Journal checksums */
 887 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT 0x1000000 /* Journal Async Commit */
 888 #define EXT4_MOUNT_I_VERSION            0x2000000 /* i_version support */
 889 #define EXT4_MOUNT_DELALLOC             0x8000000 /* Delalloc support */
 890 #define EXT4_MOUNT_DATA_ERR_ABORT       0x10000000 /* Abort on file data write */
 891 #define EXT4_MOUNT_BLOCK_VALIDITY       0x20000000 /* Block validity checking */
 892 #define EXT4_MOUNT_DISCARD              0x40000000 /* Issue DISCARD requests */
 893
 894 #define clear_opt(o, opt)               o &= ~EXT4_MOUNT_##opt
 895 #define set_opt(o, opt)                 o |= EXT4_MOUNT_##opt
 896 #define test_opt(sb, opt)               (EXT4_SB(sb)->s_mount_opt & \
 897                                          EXT4_MOUNT_##opt)
 898
 899 #define ext4_set_bit                    ext2_set_bit
 900 #define ext4_set_bit_atomic             ext2_set_bit_atomic
 901 #define ext4_clear_bit                  ext2_clear_bit
 902 #define ext4_clear_bit_atomic           ext2_clear_bit_atomic
 903 #define ext4_test_bit                   ext2_test_bit
 904 #define ext4_find_first_zero_bit        ext2_find_first_zero_bit
 905 #define ext4_find_next_zero_bit         ext2_find_next_zero_bit
 906 #define ext4_find_next_bit              ext2_find_next_bit
 907
 908 /*
 909  * Maximal mount counts between two filesystem checks
 910  */
 911 #define EXT4_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
 912 #define EXT4_DFL_CHECKINTERVAL          0       /* Don't use interval check */
 913
 914 /*
 915  * Behaviour when detecting errors
 916  */
 917 #define EXT4_ERRORS_CONTINUE            1       /* Continue execution */
 918 #define EXT4_ERRORS_RO                  2       /* Remount fs read-only */
 919 #define EXT4_ERRORS_PANIC               3       /* Panic */
 920 #define EXT4_ERRORS_DEFAULT             EXT4_ERRORS_CONTINUE
 921
 922 /*
 923  * Structure of the super block
 924  */
 925 struct ext4_super_block {
 926 /*00*/  __le32  s_inodes_count;         /* Inodes count */
 927         __le32  s_blocks_count_lo;      /* Blocks count */
 928         __le32  s_r_blocks_count_lo;    /* Reserved blocks count */
 929         __le32  s_free_blocks_count_lo; /* Free blocks count */
 930 /*10*/  __le32  s_free_inodes_count;    /* Free inodes count */
 931         __le32  s_first_data_block;     /* First Data Block */
 932         __le32  s_log_block_size;       /* Block size */
 933         __le32  s_obso_log_frag_size;   /* Obsoleted fragment size */
 934 /*20*/  __le32  s_blocks_per_group;     /* # Blocks per group */
 935         __le32  s_obso_frags_per_group; /* Obsoleted fragments per group */
 936         __le32  s_inodes_per_group;     /* # Inodes per group */
 937         __le32  s_mtime;                /* Mount time */
 938 /*30*/  __le32  s_wtime;                /* Write time */
 939         __le16  s_mnt_count;            /* Mount count */
 940         __le16  s_max_mnt_count;        /* Maximal mount count */
 941         __le16  s_magic;                /* Magic signature */
 942         __le16  s_state;                /* File system state */
 943         __le16  s_errors;               /* Behaviour when detecting errors */
 944         __le16  s_minor_rev_level;      /* minor revision level */
 945 /*40*/  __le32  s_lastcheck;            /* time of last check */
 946         __le32  s_checkinterval;        /* max. time between checks */
 947         __le32  s_creator_os;           /* OS */
 948         __le32  s_rev_level;            /* Revision level */
 949 /*50*/  __le16  s_def_resuid;           /* Default uid for reserved blocks */
 950         __le16  s_def_resgid;           /* Default gid for reserved blocks */
 951         /*
 952          * These fields are for EXT4_DYNAMIC_REV superblocks only.
 953          *
 954          * Note: the difference between the compatible feature set and
 955          * the incompatible feature set is that if there is a bit set
 956          * in the incompatible feature set that the kernel doesn't
 957          * know about, it should refuse to mount the filesystem.
 958          *
 959          * e2fsck's requirements are more strict; if it doesn't know
 960          * about a feature in either the compatible or incompatible
 961          * feature set, it must abort and not try to meddle with
 962          * things it doesn't understand...
 963          */
 964         __le32  s_first_ino;            /* First non-reserved inode */
 965         __le16  s_inode_size;           /* size of inode structure */
 966         __le16  s_block_group_nr;       /* block group # of this superblock */
 967         __le32  s_feature_compat;       /* compatible feature set */
 968 /*60*/  __le32  s_feature_incompat;     /* incompatible feature set */
 969         __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
 970 /*68*/  __u8    s_uuid[16];             /* 128-bit uuid for volume */
 971 /*78*/  char    s_volume_name[16];      /* volume name */
 972 /*88*/  char    s_last_mounted[64];     /* directory where last mounted */
 973 /*C8*/  __le32  s_algorithm_usage_bitmap; /* For compression */
 974         /*
 975          * Performance hints.  Directory preallocation should only
 976          * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
 977          */
 978         __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
 979         __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
 980         __le16  s_reserved_gdt_blocks;  /* Per group desc for online growth */
 981         /*
 982          * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
 983          */
 984 /*D0*/  __u8    s_journal_uuid[16];     /* uuid of journal superblock */
 985 /*E0*/  __le32  s_journal_inum;         /* inode number of journal file */
 986         __le32  s_journal_dev;          /* device number of journal file */
 987         __le32  s_last_orphan;          /* start of list of inodes to delete */
 988         __le32  s_hash_seed[4];         /* HTREE hash seed */
 989         __u8    s_def_hash_version;     /* Default hash version to use */
 990         __u8    s_jnl_backup_type;
 991         __le16  s_desc_size;            /* size of group descriptor */
 992 /*100*/ __le32  s_default_mount_opts;
 993         __le32  s_first_meta_bg;        /* First metablock block group */
 994         __le32  s_mkfs_time;            /* When the filesystem was created */
 995         __le32  s_jnl_blocks[17];       /* Backup of the journal inode */
 996         /* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
 997 /*150*/ __le32  s_blocks_count_hi;      /* Blocks count */
 998         __le32  s_r_blocks_count_hi;    /* Reserved blocks count */
 999         __le32  s_free_blocks_count_hi; /* Free blocks count */
1000         __le16  s_min_extra_isize;      /* All inodes have at least # bytes */
1001         __le16  s_want_extra_isize;     /* New inodes should reserve # bytes */
1002         __le32  s_flags;                /* Miscellaneous flags */
1003         __le16  s_raid_stride;          /* RAID stride */
1004         __le16  s_mmp_interval;         /* # seconds to wait in MMP checking */
1005         __le64  s_mmp_block;            /* Block for multi-mount protection */
1006         __le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1007         __u8    s_log_groups_per_flex;  /* FLEX_BG group size */
1008         __u8    s_reserved_char_pad;
1009         __le16  s_reserved_pad;
1010         __le64  s_kbytes_written;       /* nr of lifetime kilobytes written */
1011         __le32  s_snapshot_inum;        /* Inode number of active snapshot */
1012         __le32  s_snapshot_id;          /* sequential ID of active snapshot */
1013         __le64  s_snapshot_r_blocks_count; /* reserved blocks for active
1014                                               snapshot's future use */
1015         __le32  s_snapshot_list;        /* inode number of the head of the
1016                                            on-disk snapshot list */
1017 #define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
1018         __le32  s_error_count;          /* number of fs errors */
1019         __le32  s_first_error_time;     /* first time an error happened */
1020         __le32  s_first_error_ino;      /* inode involved in first error */
1021         __le64  s_first_error_block;    /* block involved of first error */
1022         __u8    s_first_error_func[32]; /* function where the error happened */
1023         __le32  s_first_error_line;     /* line number where error happened */
1024         __le32  s_last_error_time;      /* most recent time of an error */
1025         __le32  s_last_error_ino;       /* inode involved in last error */
1026         __le32  s_last_error_line;      /* line number where error happened */
1027         __le64  s_last_error_block;     /* block involved of last error */
1028         __u8    s_last_error_func[32];  /* function where the error happened */
1029 #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
1030         __u8    s_mount_opts[64];
1031         __le32  s_reserved[112];        /* Padding to the end of the block */
1032 };
1033
1034 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1035
1036 #ifdef __KERNEL__
1037
1038 /*
1039  * run-time mount flags
1040  */
1041 #define EXT4_MF_MNTDIR_SAMPLED  0x0001
1042 #define EXT4_MF_FS_ABORTED      0x0002  /* Fatal error detected */
1043
1044 /*
1045  * fourth extended-fs super-block data in memory
1046  */
1047 struct ext4_sb_info {
1048         unsigned long s_desc_size;      /* Size of a group descriptor in bytes */
1049         unsigned long s_inodes_per_block;/* Number of inodes per block */
1050         unsigned long s_blocks_per_group;/* Number of blocks in a group */
1051         unsigned long s_inodes_per_group;/* Number of inodes in a group */
1052         unsigned long s_itb_per_group;  /* Number of inode table blocks per group */
1053         unsigned long s_gdb_count;      /* Number of group descriptor blocks */
1054         unsigned long s_desc_per_block; /* Number of group descriptors per block */
1055         ext4_group_t s_groups_count;    /* Number of groups in the fs */
1056         ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1057         unsigned long s_overhead_last;  /* Last calculated overhead */
1058         unsigned long s_blocks_last;    /* Last seen block count */
1059         loff_t s_bitmap_maxbytes;       /* max bytes for bitmap files */
1060         struct buffer_head * s_sbh;     /* Buffer containing the super block */
1061         struct ext4_super_block *s_es;  /* Pointer to the super block in the buffer */
1062         struct buffer_head **s_group_desc;
1063         unsigned int s_mount_opt;
1064         unsigned int s_mount_flags;
1065         ext4_fsblk_t s_sb_block;
1066         uid_t s_resuid;
1067         gid_t s_resgid;
1068         unsigned short s_mount_state;
1069         unsigned short s_pad;
1070         int s_addr_per_block_bits;
1071         int s_desc_per_block_bits;
1072         int s_inode_size;
1073         int s_first_ino;
1074         unsigned int s_inode_readahead_blks;
1075         unsigned int s_inode_goal;
1076         spinlock_t s_next_gen_lock;
1077         u32 s_next_generation;
1078         u32 s_hash_seed[4];
1079         int s_def_hash_version;
1080         int s_hash_unsigned;    /* 3 if hash should be signed, 0 if not */
1081         struct percpu_counter s_freeblocks_counter;
1082         struct percpu_counter s_freeinodes_counter;
1083         struct percpu_counter s_dirs_counter;
1084         struct percpu_counter s_dirtyblocks_counter;
1085         struct blockgroup_lock *s_blockgroup_lock;
1086         struct proc_dir_entry *s_proc;
1087         struct kobject s_kobj;
1088         struct completion s_kobj_unregister;
1089
1090         /* Journaling */
1091         struct inode *s_journal_inode;
1092         struct journal_s *s_journal;
1093         struct list_head s_orphan;
1094         struct mutex s_orphan_lock;
1095         struct mutex s_resize_lock;
1096         unsigned long s_commit_interval;
1097         u32 s_max_batch_time;
1098         u32 s_min_batch_time;
1099         struct block_device *journal_bdev;
1100 #ifdef CONFIG_JBD2_DEBUG
1101         struct timer_list turn_ro_timer;        /* For turning read-only (crash simulation) */
1102         wait_queue_head_t ro_wait_queue;        /* For people waiting for the fs to go read-only */
1103 #endif
1104 #ifdef CONFIG_QUOTA
1105         char *s_qf_names[MAXQUOTAS];            /* Names of quota files with journalled quota */
1106         int s_jquota_fmt;                       /* Format of quota to use */
1107 #endif
1108         unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1109         struct rb_root system_blks;
1110
1111 #ifdef EXTENTS_STATS
1112         /* ext4 extents stats */
1113         unsigned long s_ext_min;
1114         unsigned long s_ext_max;
1115         unsigned long s_depth_max;
1116         spinlock_t s_ext_stats_lock;
1117         unsigned long s_ext_blocks;
1118         unsigned long s_ext_extents;
1119 #endif
1120
1121         /* for buddy allocator */
1122         struct ext4_group_info ***s_group_info;
1123         struct inode *s_buddy_cache;
1124         long s_blocks_reserved;
1125         spinlock_t s_reserve_lock;
1126         spinlock_t s_md_lock;
1127         tid_t s_last_transaction;
1128         unsigned short *s_mb_offsets;
1129         unsigned int *s_mb_maxs;
1130
1131         /* tunables */
1132         unsigned long s_stripe;
1133         unsigned int s_mb_stream_request;
1134         unsigned int s_mb_max_to_scan;
1135         unsigned int s_mb_min_to_scan;
1136         unsigned int s_mb_stats;
1137         unsigned int s_mb_order2_reqs;
1138         unsigned int s_mb_group_prealloc;
1139         unsigned int s_max_writeback_mb_bump;
1140         /* where last allocation was done - for stream allocation */
1141         unsigned long s_mb_last_group;
1142         unsigned long s_mb_last_start;
1143
1144         /* stats for buddy allocator */
1145         spinlock_t s_mb_pa_lock;
1146         atomic_t s_bal_reqs;    /* number of reqs with len > 1 */
1147         atomic_t s_bal_success; /* we found long enough chunks */
1148         atomic_t s_bal_allocated;       /* in blocks */
1149         atomic_t s_bal_ex_scanned;      /* total extents scanned */
1150         atomic_t s_bal_goals;   /* goal hits */
1151         atomic_t s_bal_breaks;  /* too long searches */
1152         atomic_t s_bal_2orders; /* 2^order hits */
1153         spinlock_t s_bal_lock;
1154         unsigned long s_mb_buddies_generated;
1155         unsigned long long s_mb_generation_time;
1156         atomic_t s_mb_lost_chunks;
1157         atomic_t s_mb_preallocated;
1158         atomic_t s_mb_discarded;
1159         atomic_t s_lock_busy;
1160
1161         /* locality groups */
1162         struct ext4_locality_group __percpu *s_locality_groups;
1163
1164         /* for write statistics */
1165         unsigned long s_sectors_written_start;
1166         u64 s_kbytes_written;
1167
1168         unsigned int s_log_groups_per_flex;
1169         struct flex_groups *s_flex_groups;
1170
1171         /* workqueue for dio unwritten */
1172         struct workqueue_struct *dio_unwritten_wq;
1173
1174         /* timer for periodic error stats printing */
1175         struct timer_list s_err_report;
1176 };
1177
1178 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1179 {
1180         return sb->s_fs_info;
1181 }
1182 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1183 {
1184         return container_of(inode, struct ext4_inode_info, vfs_inode);
1185 }
1186
1187 static inline struct timespec ext4_current_time(struct inode *inode)
1188 {
1189         return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1190                 current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1191 }
1192
1193 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1194 {
1195         return ino == EXT4_ROOT_INO ||
1196                 ino == EXT4_JOURNAL_INO ||
1197                 ino == EXT4_RESIZE_INO ||
1198                 (ino >= EXT4_FIRST_INO(sb) &&
1199                  ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1200 }
1201
1202 /*
1203  * Inode dynamic state flags
1204  */
1205 enum {
1206         EXT4_STATE_JDATA,               /* journaled data exists */
1207         EXT4_STATE_NEW,                 /* inode is newly created */
1208         EXT4_STATE_XATTR,               /* has in-inode xattrs */
1209         EXT4_STATE_NO_EXPAND,           /* No space for expansion */
1210         EXT4_STATE_DA_ALLOC_CLOSE,      /* Alloc DA blks on close */
1211         EXT4_STATE_EXT_MIGRATE,         /* Inode is migrating */
1212         EXT4_STATE_DIO_UNWRITTEN,       /* need convert on dio done*/
1213         EXT4_STATE_NEWENTRY,            /* File just added to dir */
1214 };
1215
1216 #define EXT4_INODE_BIT_FNS(name, field)                                 \
1217 static inline int ext4_test_inode_##name(struct inode *inode, int bit)  \
1218 {                                                                       \
1219         return test_bit(bit, &EXT4_I(inode)->i_##field);                \
1220 }                                                                       \
1221 static inline void ext4_set_inode_##name(struct inode *inode, int bit)  \
1222 {                                                                       \
1223         set_bit(bit, &EXT4_I(inode)->i_##field);                        \
1224 }                                                                       \
1225 static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1226 {                                                                       \
1227         clear_bit(bit, &EXT4_I(inode)->i_##field);                      \
1228 }
1229
1230 EXT4_INODE_BIT_FNS(flag, flags)
1231 EXT4_INODE_BIT_FNS(state, state_flags)
1232 #else
1233 /* Assume that user mode programs are passing in an ext4fs superblock, not
1234  * a kernel struct super_block.  This will allow us to call the feature-test
1235  * macros from user land. */
1236 #define EXT4_SB(sb)     (sb)
1237 #endif
1238
1239 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1240
1241 /*
1242  * Codes for operating systems
1243  */
1244 #define EXT4_OS_LINUX           0
1245 #define EXT4_OS_HURD            1
1246 #define EXT4_OS_MASIX           2
1247 #define EXT4_OS_FREEBSD         3
1248 #define EXT4_OS_LITES           4
1249
1250 /*
1251  * Revision levels
1252  */
1253 #define EXT4_GOOD_OLD_REV       0       /* The good old (original) format */
1254 #define EXT4_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
1255
1256 #define EXT4_CURRENT_REV        EXT4_GOOD_OLD_REV
1257 #define EXT4_MAX_SUPP_REV       EXT4_DYNAMIC_REV
1258
1259 #define EXT4_GOOD_OLD_INODE_SIZE 128
1260
1261 /*
1262  * Feature set definitions
1263  */
1264
1265 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)                        \
1266         ((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1267 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
1268         ((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1269 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)                      \
1270         ((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1271 #define EXT4_SET_COMPAT_FEATURE(sb,mask)                        \
1272         EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1273 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)                     \
1274         EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1275 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)                      \
1276         EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1277 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)                      \
1278         EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1279 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
1280         EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1281 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
1282         EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1283
1284 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC        0x0001
1285 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES       0x0002
1286 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL         0x0004
1287 #define EXT4_FEATURE_COMPAT_EXT_ATTR            0x0008
1288 #define EXT4_FEATURE_COMPAT_RESIZE_INODE        0x0010
1289 #define EXT4_FEATURE_COMPAT_DIR_INDEX           0x0020
1290
1291 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
1292 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
1293 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
1294 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1295 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM         0x0010
1296 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK        0x0020
1297 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE      0x0040
1298
1299 #define EXT4_FEATURE_INCOMPAT_COMPRESSION       0x0001
1300 #define EXT4_FEATURE_INCOMPAT_FILETYPE          0x0002
1301 #define EXT4_FEATURE_INCOMPAT_RECOVER           0x0004 /* Needs recovery */
1302 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008 /* Journal device */
1303 #define EXT4_FEATURE_INCOMPAT_META_BG           0x0010
1304 #define EXT4_FEATURE_INCOMPAT_EXTENTS           0x0040 /* extents support */
1305 #define EXT4_FEATURE_INCOMPAT_64BIT             0x0080
1306 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1307 #define EXT4_FEATURE_INCOMPAT_FLEX_BG           0x0200
1308 #define EXT4_FEATURE_INCOMPAT_EA_INODE          0x0400 /* EA in inode */
1309 #define EXT4_FEATURE_INCOMPAT_DIRDATA           0x1000 /* data in dirent */
1310
1311 #define EXT4_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
1312 #define EXT4_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1313                                          EXT4_FEATURE_INCOMPAT_RECOVER| \
1314                                          EXT4_FEATURE_INCOMPAT_META_BG| \
1315                                          EXT4_FEATURE_INCOMPAT_EXTENTS| \
1316                                          EXT4_FEATURE_INCOMPAT_64BIT| \
1317                                          EXT4_FEATURE_INCOMPAT_FLEX_BG)
1318 #define EXT4_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1319                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1320                                          EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1321                                          EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1322                                          EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1323                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1324                                          EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
1325
1326 /*
1327  * Default values for user and/or group using reserved blocks
1328  */
1329 #define EXT4_DEF_RESUID         0
1330 #define EXT4_DEF_RESGID         0
1331
1332 #define EXT4_DEF_INODE_READAHEAD_BLKS   32
1333
1334 /*
1335  * Default mount options
1336  */
1337 #define EXT4_DEFM_DEBUG         0x0001
1338 #define EXT4_DEFM_BSDGROUPS     0x0002
1339 #define EXT4_DEFM_XATTR_USER    0x0004
1340 #define EXT4_DEFM_ACL           0x0008
1341 #define EXT4_DEFM_UID16         0x0010
1342 #define EXT4_DEFM_JMODE         0x0060
1343 #define EXT4_DEFM_JMODE_DATA    0x0020
1344 #define EXT4_DEFM_JMODE_ORDERED 0x0040
1345 #define EXT4_DEFM_JMODE_WBACK   0x0060
1346 #define EXT4_DEFM_NOBARRIER     0x0100
1347 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
1348 #define EXT4_DEFM_DISCARD       0x0400
1349 #define EXT4_DEFM_NODELALLOC    0x0800
1350
1351 /*
1352  * Default journal batch times
1353  */
1354 #define EXT4_DEF_MIN_BATCH_TIME 0
1355 #define EXT4_DEF_MAX_BATCH_TIME 15000 /* 15ms */
1356
1357 /*
1358  * Minimum number of groups in a flexgroup before we separate out
1359  * directories into the first block group of a flexgroup
1360  */
1361 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME 4
1362
1363 /*
1364  * Structure of a directory entry
1365  */
1366 #define EXT4_NAME_LEN 255
1367
1368 struct ext4_dir_entry {
1369         __le32  inode;                  /* Inode number */
1370         __le16  rec_len;                /* Directory entry length */
1371         __le16  name_len;               /* Name length */
1372         char    name[EXT4_NAME_LEN];    /* File name */
1373 };
1374
1375 /*
1376  * The new version of the directory entry.  Since EXT4 structures are
1377  * stored in intel byte order, and the name_len field could never be
1378  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1379  * file_type field.
1380  */
1381 struct ext4_dir_entry_2 {
1382         __le32  inode;                  /* Inode number */
1383         __le16  rec_len;                /* Directory entry length */
1384         __u8    name_len;               /* Name length */
1385         __u8    file_type;
1386         char    name[EXT4_NAME_LEN];    /* File name */
1387 };
1388
1389 /*
1390  * Ext4 directory file types.  Only the low 3 bits are used.  The
1391  * other bits are reserved for now.
1392  */
1393 #define EXT4_FT_UNKNOWN         0
1394 #define EXT4_FT_REG_FILE        1
1395 #define EXT4_FT_DIR             2
1396 #define EXT4_FT_CHRDEV          3
1397 #define EXT4_FT_BLKDEV          4
1398 #define EXT4_FT_FIFO            5
1399 #define EXT4_FT_SOCK            6
1400 #define EXT4_FT_SYMLINK         7
1401
1402 #define EXT4_FT_MAX             8
1403
1404 /*
1405  * EXT4_DIR_PAD defines the directory entries boundaries
1406  *
1407  * NOTE: It must be a multiple of 4
1408  */
1409 #define EXT4_DIR_PAD                    4
1410 #define EXT4_DIR_ROUND                  (EXT4_DIR_PAD - 1)
1411 #define EXT4_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT4_DIR_ROUND) & \
1412                                          ~EXT4_DIR_ROUND)
1413 #define EXT4_MAX_REC_LEN                ((1<<16)-1)
1414
1415 /*
1416  * If we ever get support for fs block sizes > page_size, we'll need
1417  * to remove the #if statements in the next two functions...
1418  */
1419 static inline unsigned int
1420 ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
1421 {
1422         unsigned len = le16_to_cpu(dlen);
1423
1424 #if (PAGE_CACHE_SIZE >= 65536)
1425         if (len == EXT4_MAX_REC_LEN || len == 0)
1426                 return blocksize;
1427         return (len & 65532) | ((len & 3) << 16);
1428 #else
1429         return len;
1430 #endif
1431 }
1432
1433 static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
1434 {
1435         if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
1436                 BUG();
1437 #if (PAGE_CACHE_SIZE >= 65536)
1438         if (len < 65536)
1439                 return cpu_to_le16(len);
1440         if (len == blocksize) {
1441                 if (blocksize == 65536)
1442                         return cpu_to_le16(EXT4_MAX_REC_LEN);
1443                 else
1444                         return cpu_to_le16(0);
1445         }
1446         return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
1447 #else
1448         return cpu_to_le16(len);
1449 #endif
1450 }
1451
1452 /*
1453  * Hash Tree Directory indexing
1454  * (c) Daniel Phillips, 2001
1455  */
1456
1457 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1458                                       EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1459                     ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
1460 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1461 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1462
1463 /* Legal values for the dx_root hash_version field: */
1464
1465 #define DX_HASH_LEGACY          0
1466 #define DX_HASH_HALF_MD4        1
1467 #define DX_HASH_TEA             2
1468 #define DX_HASH_LEGACY_UNSIGNED 3
1469 #define DX_HASH_HALF_MD4_UNSIGNED       4
1470 #define DX_HASH_TEA_UNSIGNED            5
1471
1472 #ifdef __KERNEL__
1473
1474 /* hash info structure used by the directory hash */
1475 struct dx_hash_info
1476 {
1477         u32             hash;
1478         u32             minor_hash;
1479         int             hash_version;
1480         u32             *seed;
1481 };
1482
1483 #define EXT4_HTREE_EOF  0x7fffffff
1484
1485 /*
1486  * Control parameters used by ext4_htree_next_block
1487  */
1488 #define HASH_NB_ALWAYS          1
1489
1490
1491 /*
1492  * Describe an inode's exact location on disk and in memory
1493  */
1494 struct ext4_iloc
1495 {
1496         struct buffer_head *bh;
1497         unsigned long offset;
1498         ext4_group_t block_group;
1499 };
1500
1501 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1502 {
1503         return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1504 }
1505
1506 /*
1507  * This structure is stuffed into the struct file's private_data field
1508  * for directories.  It is where we put information so that we can do
1509  * readdir operations in hash tree order.
1510  */
1511 struct dir_private_info {
1512         struct rb_root  root;
1513         struct rb_node  *curr_node;
1514         struct fname    *extra_fname;
1515         loff_t          last_pos;
1516         __u32           curr_hash;
1517         __u32           curr_minor_hash;
1518         __u32           next_hash;
1519 };
1520
1521 /* calculate the first block number of the group */
1522 static inline ext4_fsblk_t
1523 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1524 {
1525         return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1526                 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1527 }
1528
1529 /*
1530  * Special error return code only used by dx_probe() and its callers.
1531  */
1532 #define ERR_BAD_DX_DIR  -75000
1533
1534 void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
1535                         ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp);
1536
1537 extern struct proc_dir_entry *ext4_proc_root;
1538
1539 /*
1540  * Function prototypes
1541  */
1542
1543 /*
1544  * Ok, these declarations are also in <linux/kernel.h> but none of the
1545  * ext4 source programs needs to include it so they are duplicated here.
1546  */
1547 # define NORET_TYPE     /**/
1548 # define ATTRIB_NORET   __attribute__((noreturn))
1549 # define NORET_AND      noreturn,
1550
1551 /* bitmap.c */
1552 extern unsigned int ext4_count_free(struct buffer_head *, unsigned);
1553
1554 /* balloc.c */
1555 extern unsigned int ext4_block_group(struct super_block *sb,
1556                         ext4_fsblk_t blocknr);
1557 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1558                         ext4_fsblk_t blocknr);
1559 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1560 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1561                         ext4_group_t group);
1562 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1563                         ext4_fsblk_t goal, unsigned long *count, int *errp);
1564 extern int ext4_claim_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
1565 extern int ext4_has_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
1566 extern void ext4_add_groupblocks(handle_t *handle, struct super_block *sb,
1567                                 ext4_fsblk_t block, unsigned long count);
1568 extern ext4_fsblk_t ext4_count_free_blocks(struct super_block *);
1569 extern void ext4_check_blocks_bitmap(struct super_block *);
1570 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1571                                                     ext4_group_t block_group,
1572                                                     struct buffer_head ** bh);
1573 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1574 struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1575                                       ext4_group_t block_group);
1576 extern unsigned ext4_init_block_bitmap(struct super_block *sb,
1577                                        struct buffer_head *bh,
1578                                        ext4_group_t group,
1579                                        struct ext4_group_desc *desc);
1580 #define ext4_free_blocks_after_init(sb, group, desc)                    \
1581                 ext4_init_block_bitmap(sb, NULL, group, desc)
1582
1583 /* dir.c */
1584 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
1585                                   struct ext4_dir_entry_2 *,
1586                                   struct buffer_head *, unsigned int);
1587 #define ext4_check_dir_entry(dir, de, bh, offset) \
1588         __ext4_check_dir_entry(__func__, __LINE__, (dir), (de), (bh), (offset))
1589 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1590                                     __u32 minor_hash,
1591                                     struct ext4_dir_entry_2 *dirent);
1592 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
1593
1594 /* fsync.c */
1595 extern int ext4_sync_file(struct file *, int);
1596
1597 /* hash.c */
1598 extern int ext4fs_dirhash(const char *name, int len, struct
1599                           dx_hash_info *hinfo);
1600
1601 /* ialloc.c */
1602 extern struct inode *ext4_new_inode(handle_t *, struct inode *, int,
1603                                     const struct qstr *qstr, __u32 goal);
1604 extern void ext4_free_inode(handle_t *, struct inode *);
1605 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
1606 extern unsigned long ext4_count_free_inodes(struct super_block *);
1607 extern unsigned long ext4_count_dirs(struct super_block *);
1608 extern void ext4_check_inodes_bitmap(struct super_block *);
1609 extern unsigned ext4_init_inode_bitmap(struct super_block *sb,
1610                                        struct buffer_head *bh,
1611                                        ext4_group_t group,
1612                                        struct ext4_group_desc *desc);
1613 extern void mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
1614
1615 /* mballoc.c */
1616 extern long ext4_mb_stats;
1617 extern long ext4_mb_max_to_scan;
1618 extern int ext4_mb_init(struct super_block *, int);
1619 extern int ext4_mb_release(struct super_block *);
1620 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
1621                                 struct ext4_allocation_request *, int *);
1622 extern int ext4_mb_reserve_blocks(struct super_block *, int);
1623 extern void ext4_discard_preallocations(struct inode *);
1624 extern int __init init_ext4_mballoc(void);
1625 extern void exit_ext4_mballoc(void);
1626 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
1627                              struct buffer_head *bh, ext4_fsblk_t block,
1628                              unsigned long count, int flags);
1629 extern int ext4_mb_add_groupinfo(struct super_block *sb,
1630                 ext4_group_t i, struct ext4_group_desc *desc);
1631 extern int ext4_mb_get_buddy_cache_lock(struct super_block *, ext4_group_t);
1632 extern void ext4_mb_put_buddy_cache_lock(struct super_block *,
1633                                                 ext4_group_t, int);
1634 /* inode.c */
1635 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
1636                                                 ext4_lblk_t, int, int *);
1637 struct buffer_head *ext4_bread(handle_t *, struct inode *,
1638                                                 ext4_lblk_t, int, int *);
1639 int ext4_get_block(struct inode *inode, sector_t iblock,
1640                                 struct buffer_head *bh_result, int create);
1641
1642 extern struct inode *ext4_iget(struct super_block *, unsigned long);
1643 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
1644 extern int  ext4_setattr(struct dentry *, struct iattr *);
1645 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
1646                                 struct kstat *stat);
1647 extern void ext4_evict_inode(struct inode *);
1648 extern void ext4_clear_inode(struct inode *);
1649 extern int  ext4_sync_inode(handle_t *, struct inode *);
1650 extern void ext4_dirty_inode(struct inode *);
1651 extern int ext4_change_inode_journal_flag(struct inode *, int);
1652 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
1653 extern int ext4_can_truncate(struct inode *inode);
1654 extern void ext4_truncate(struct inode *);
1655 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
1656 extern void ext4_set_inode_flags(struct inode *);
1657 extern void ext4_get_inode_flags(struct ext4_inode_info *);
1658 extern int ext4_alloc_da_blocks(struct inode *inode);
1659 extern void ext4_set_aops(struct inode *inode);
1660 extern int ext4_writepage_trans_blocks(struct inode *);
1661 extern int ext4_meta_trans_blocks(struct inode *, int nrblocks, int idxblocks);
1662 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
1663 extern int ext4_block_truncate_page(handle_t *handle,
1664                 struct address_space *mapping, loff_t from);
1665 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
1666 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
1667 extern int flush_completed_IO(struct inode *inode);
1668 extern void ext4_da_update_reserve_space(struct inode *inode,
1669                                         int used, int quota_claim);
1670 /* ioctl.c */
1671 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
1672 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
1673
1674 /* migrate.c */
1675 extern int ext4_ext_migrate(struct inode *);
1676
1677 /* namei.c */
1678 extern int ext4_orphan_add(handle_t *, struct inode *);
1679 extern int ext4_orphan_del(handle_t *, struct inode *);
1680 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1681                                 __u32 start_minor_hash, __u32 *next_hash);
1682
1683 /* resize.c */
1684 extern int ext4_group_add(struct super_block *sb,
1685                                 struct ext4_new_group_data *input);
1686 extern int ext4_group_extend(struct super_block *sb,
1687                                 struct ext4_super_block *es,
1688                                 ext4_fsblk_t n_blocks_count);
1689
1690 /* super.c */
1691 extern void __ext4_error(struct super_block *, const char *, unsigned int,
1692                          const char *, ...)
1693         __attribute__ ((format (printf, 4, 5)));
1694 #define ext4_error(sb, message...)      __ext4_error(sb, __func__,      \
1695                                                      __LINE__, ## message)
1696 extern void ext4_error_inode(struct inode *, const char *, unsigned int,
1697                              ext4_fsblk_t, const char *, ...)
1698         __attribute__ ((format (printf, 5, 6)));
1699 extern void ext4_error_file(struct file *, const char *, unsigned int,
1700                             const char *, ...)
1701         __attribute__ ((format (printf, 4, 5)));
1702 extern void __ext4_std_error(struct super_block *, const char *,
1703                              unsigned int, int);
1704 extern void __ext4_abort(struct super_block *, const char *, unsigned int,
1705                        const char *, ...)
1706         __attribute__ ((format (printf, 4, 5)));
1707 #define ext4_abort(sb, message...)      __ext4_abort(sb, __func__, \
1708                                                        __LINE__, ## message)
1709 extern void __ext4_warning(struct super_block *, const char *, unsigned int,
1710                           const char *, ...)
1711         __attribute__ ((format (printf, 4, 5)));
1712 #define ext4_warning(sb, message...)    __ext4_warning(sb, __func__, \
1713                                                        __LINE__, ## message)
1714 extern void ext4_msg(struct super_block *, const char *, const char *, ...)
1715         __attribute__ ((format (printf, 3, 4)));
1716 extern void __ext4_grp_locked_error(const char *, unsigned int, \
1717                                     struct super_block *, ext4_group_t, \
1718                                     unsigned long, ext4_fsblk_t, \
1719                                     const char *, ...)
1720         __attribute__ ((format (printf, 7, 8)));
1721 #define ext4_grp_locked_error(sb, grp, message...) \
1722         __ext4_grp_locked_error(__func__, __LINE__, (sb), (grp), ## message)
1723 extern void ext4_update_dynamic_rev(struct super_block *sb);
1724 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
1725                                         __u32 compat);
1726 extern int ext4_update_rocompat_feature(handle_t *handle,
1727                                         struct super_block *sb, __u32 rocompat);
1728 extern int ext4_update_incompat_feature(handle_t *handle,
1729                                         struct super_block *sb, __u32 incompat);
1730 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
1731                                       struct ext4_group_desc *bg);
1732 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
1733                                       struct ext4_group_desc *bg);
1734 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
1735                                      struct ext4_group_desc *bg);
1736 extern __u32 ext4_free_blks_count(struct super_block *sb,
1737                                 struct ext4_group_desc *bg);
1738 extern __u32 ext4_free_inodes_count(struct super_block *sb,
1739                                  struct ext4_group_desc *bg);
1740 extern __u32 ext4_used_dirs_count(struct super_block *sb,
1741                                 struct ext4_group_desc *bg);
1742 extern __u32 ext4_itable_unused_count(struct super_block *sb,
1743                                    struct ext4_group_desc *bg);
1744 extern void ext4_block_bitmap_set(struct super_block *sb,
1745                                   struct ext4_group_desc *bg, ext4_fsblk_t blk);
1746 extern void ext4_inode_bitmap_set(struct super_block *sb,
1747                                   struct ext4_group_desc *bg, ext4_fsblk_t blk);
1748 extern void ext4_inode_table_set(struct super_block *sb,
1749                                  struct ext4_group_desc *bg, ext4_fsblk_t blk);
1750 extern void ext4_free_blks_set(struct super_block *sb,
1751                                struct ext4_group_desc *bg, __u32 count);
1752 extern void ext4_free_inodes_set(struct super_block *sb,
1753                                 struct ext4_group_desc *bg, __u32 count);
1754 extern void ext4_used_dirs_set(struct super_block *sb,
1755                                 struct ext4_group_desc *bg, __u32 count);
1756 extern void ext4_itable_unused_set(struct super_block *sb,
1757                                    struct ext4_group_desc *bg, __u32 count);
1758 extern __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 group,
1759                                    struct ext4_group_desc *gdp);
1760 extern int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 group,
1761                                        struct ext4_group_desc *gdp);
1762
1763 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
1764 {
1765         return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
1766                 le32_to_cpu(es->s_blocks_count_lo);
1767 }
1768
1769 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
1770 {
1771         return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
1772                 le32_to_cpu(es->s_r_blocks_count_lo);
1773 }
1774
1775 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
1776 {
1777         return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
1778                 le32_to_cpu(es->s_free_blocks_count_lo);
1779 }
1780
1781 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
1782                                          ext4_fsblk_t blk)
1783 {
1784         es->s_blocks_count_lo = cpu_to_le32((u32)blk);
1785         es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
1786 }
1787
1788 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
1789                                               ext4_fsblk_t blk)
1790 {
1791         es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
1792         es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
1793 }
1794
1795 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
1796                                            ext4_fsblk_t blk)
1797 {
1798         es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
1799         es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
1800 }
1801
1802 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
1803 {
1804         if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
1805                 return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
1806                         le32_to_cpu(raw_inode->i_size_lo);
1807         else
1808                 return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
1809 }
1810
1811 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
1812 {
1813         raw_inode->i_size_lo = cpu_to_le32(i_size);
1814         raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
1815 }
1816
1817 static inline
1818 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
1819                                             ext4_group_t group)
1820 {
1821          struct ext4_group_info ***grp_info;
1822          long indexv, indexh;
1823          grp_info = EXT4_SB(sb)->s_group_info;
1824          indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
1825          indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
1826          return grp_info[indexv][indexh];
1827 }
1828
1829 /*
1830  * Reading s_groups_count requires using smp_rmb() afterwards.  See
1831  * the locking protocol documented in the comments of ext4_group_add()
1832  * in resize.c
1833  */
1834 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
1835 {
1836         ext4_group_t    ngroups = EXT4_SB(sb)->s_groups_count;
1837
1838         smp_rmb();
1839         return ngroups;
1840 }
1841
1842 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
1843                                              ext4_group_t block_group)
1844 {
1845         return block_group >> sbi->s_log_groups_per_flex;
1846 }
1847
1848 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
1849 {
1850         return 1 << sbi->s_log_groups_per_flex;
1851 }
1852
1853 #define ext4_std_error(sb, errno)                               \
1854 do {                                                            \
1855         if ((errno))                                            \
1856                 __ext4_std_error((sb), __func__, __LINE__, (errno));    \
1857 } while (0)
1858
1859 #ifdef CONFIG_SMP
1860 /* Each CPU can accumulate percpu_counter_batch blocks in their local
1861  * counters. So we need to make sure we have free blocks more
1862  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
1863  */
1864 #define EXT4_FREEBLOCKS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
1865 #else
1866 #define EXT4_FREEBLOCKS_WATERMARK 0
1867 #endif
1868
1869 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
1870 {
1871         /*
1872          * XXX: replace with spinlock if seen contended -bzzz
1873          */
1874         down_write(&EXT4_I(inode)->i_data_sem);
1875         if (newsize > EXT4_I(inode)->i_disksize)
1876                 EXT4_I(inode)->i_disksize = newsize;
1877         up_write(&EXT4_I(inode)->i_data_sem);
1878         return ;
1879 }
1880
1881 struct ext4_group_info {
1882         unsigned long   bb_state;
1883         struct rb_root  bb_free_root;
1884         ext4_grpblk_t   bb_first_free;  /* first free block */
1885         ext4_grpblk_t   bb_free;        /* total free blocks */
1886         ext4_grpblk_t   bb_fragments;   /* nr of freespace fragments */
1887         ext4_grpblk_t   bb_largest_free_order;/* order of largest frag in BG */
1888         struct          list_head bb_prealloc_list;
1889 #ifdef DOUBLE_CHECK
1890         void            *bb_bitmap;
1891 #endif
1892         struct rw_semaphore alloc_sem;
1893         ext4_grpblk_t   bb_counters[];  /* Nr of free power-of-two-block
1894                                          * regions, index is order.
1895                                          * bb_counters[3] = 5 means
1896                                          * 5 free 8-block regions. */
1897 };
1898
1899 #define EXT4_GROUP_INFO_NEED_INIT_BIT   0
1900
1901 #define EXT4_MB_GRP_NEED_INIT(grp)      \
1902         (test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
1903
1904 #define EXT4_MAX_CONTENTION             8
1905 #define EXT4_CONTENTION_THRESHOLD       2
1906
1907 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
1908                                               ext4_group_t group)
1909 {
1910         return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
1911 }
1912
1913 /*
1914  * Returns true if the filesystem is busy enough that attempts to
1915  * access the block group locks has run into contention.
1916  */
1917 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
1918 {
1919         return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
1920 }
1921
1922 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
1923 {
1924         spinlock_t *lock = ext4_group_lock_ptr(sb, group);
1925         if (spin_trylock(lock))
1926                 /*
1927                  * We're able to grab the lock right away, so drop the
1928                  * lock contention counter.
1929                  */
1930                 atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
1931         else {
1932                 /*
1933                  * The lock is busy, so bump the contention counter,
1934                  * and then wait on the spin lock.
1935                  */
1936                 atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
1937                                   EXT4_MAX_CONTENTION);
1938                 spin_lock(lock);
1939         }
1940 }
1941
1942 static inline void ext4_unlock_group(struct super_block *sb,
1943                                         ext4_group_t group)
1944 {
1945         spin_unlock(ext4_group_lock_ptr(sb, group));
1946 }
1947
1948 static inline void ext4_mark_super_dirty(struct super_block *sb)
1949 {
1950         if (EXT4_SB(sb)->s_journal == NULL)
1951                 sb->s_dirt =1;
1952 }
1953
1954 /*
1955  * Inodes and files operations
1956  */
1957
1958 /* dir.c */
1959 extern const struct file_operations ext4_dir_operations;
1960
1961 /* file.c */
1962 extern const struct inode_operations ext4_file_inode_operations;
1963 extern const struct file_operations ext4_file_operations;
1964
1965 /* namei.c */
1966 extern const struct inode_operations ext4_dir_inode_operations;
1967 extern const struct inode_operations ext4_special_inode_operations;
1968 extern struct dentry *ext4_get_parent(struct dentry *child);
1969
1970 /* symlink.c */
1971 extern const struct inode_operations ext4_symlink_inode_operations;
1972 extern const struct inode_operations ext4_fast_symlink_inode_operations;
1973
1974 /* block_validity */
1975 extern void ext4_release_system_zone(struct super_block *sb);
1976 extern int ext4_setup_system_zone(struct super_block *sb);
1977 extern int __init init_ext4_system_zone(void);
1978 extern void exit_ext4_system_zone(void);
1979 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
1980                                  ext4_fsblk_t start_blk,
1981                                  unsigned int count);
1982
1983 /* extents.c */
1984 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
1985 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
1986 extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks,
1987                                        int chunk);
1988 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
1989                                struct ext4_map_blocks *map, int flags);
1990 extern void ext4_ext_truncate(struct inode *);
1991 extern void ext4_ext_init(struct super_block *);
1992 extern void ext4_ext_release(struct super_block *);
1993 extern long ext4_fallocate(struct inode *inode, int mode, loff_t offset,
1994                           loff_t len);
1995 extern int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
1996                           ssize_t len);
1997 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
1998                            struct ext4_map_blocks *map, int flags);
1999 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
2000                         __u64 start, __u64 len);
2001 /* move_extent.c */
2002 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
2003                              __u64 start_orig, __u64 start_donor,
2004                              __u64 len, __u64 *moved_len);
2005
2006
2007 /* BH_Uninit flag: blocks are allocated but uninitialized on disk */
2008 enum ext4_state_bits {
2009         BH_Uninit       /* blocks are allocated but uninitialized on disk */
2010           = BH_JBDPrivateStart,
2011 };
2012
2013 BUFFER_FNS(Uninit, uninit)
2014 TAS_BUFFER_FNS(Uninit, uninit)
2015
2016 /*
2017  * Add new method to test wether block and inode bitmaps are properly
2018  * initialized. With uninit_bg reading the block from disk is not enough
2019  * to mark the bitmap uptodate. We need to also zero-out the bitmap
2020  */
2021 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
2022
2023 static inline int bitmap_uptodate(struct buffer_head *bh)
2024 {
2025         return (buffer_uptodate(bh) &&
2026                         test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
2027 }
2028 static inline void set_bitmap_uptodate(struct buffer_head *bh)
2029 {
2030         set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
2031 }
2032
2033 #define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
2034
2035 #endif  /* __KERNEL__ */
2036
2037 #endif  /* _EXT4_H */