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