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_reserved)
1029         __le32   s_reserved[128];        /* Padding to the end of the block */
1030 };
1031
1032 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1033
1034 #ifdef __KERNEL__
1035
1036 /*
1037  * run-time mount flags
1038  */
1039 #define EXT4_MF_MNTDIR_SAMPLED  0x0001
1040 #define EXT4_MF_FS_ABORTED      0x0002  /* Fatal error detected */
1041
1042 /*
1043  * fourth extended-fs super-block data in memory
1044  */
1045 struct ext4_sb_info {
1046         unsigned long s_desc_size;      /* Size of a group descriptor in bytes */
1047         unsigned long s_inodes_per_block;/* Number of inodes per block */
1048         unsigned long s_blocks_per_group;/* Number of blocks in a group */
1049         unsigned long s_inodes_per_group;/* Number of inodes in a group */
1050         unsigned long s_itb_per_group;  /* Number of inode table blocks per group */
1051         unsigned long s_gdb_count;      /* Number of group descriptor blocks */
1052         unsigned long s_desc_per_block; /* Number of group descriptors per block */
1053         ext4_group_t s_groups_count;    /* Number of groups in the fs */
1054         ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1055         unsigned long s_overhead_last;  /* Last calculated overhead */
1056         unsigned long s_blocks_last;    /* Last seen block count */
1057         loff_t s_bitmap_maxbytes;       /* max bytes for bitmap files */
1058         struct buffer_head * s_sbh;     /* Buffer containing the super block */
1059         struct ext4_super_block *s_es;  /* Pointer to the super block in the buffer */
1060         struct buffer_head **s_group_desc;
1061         unsigned int s_mount_opt;
1062         unsigned int s_mount_flags;
1063         ext4_fsblk_t s_sb_block;
1064         uid_t s_resuid;
1065         gid_t s_resgid;
1066         unsigned short s_mount_state;
1067         unsigned short s_pad;
1068         int s_addr_per_block_bits;
1069         int s_desc_per_block_bits;
1070         int s_inode_size;
1071         int s_first_ino;
1072         unsigned int s_inode_readahead_blks;
1073         unsigned int s_inode_goal;
1074         spinlock_t s_next_gen_lock;
1075         u32 s_next_generation;
1076         u32 s_hash_seed[4];
1077         int s_def_hash_version;
1078         int s_hash_unsigned;    /* 3 if hash should be signed, 0 if not */
1079         struct percpu_counter s_freeblocks_counter;
1080         struct percpu_counter s_freeinodes_counter;
1081         struct percpu_counter s_dirs_counter;
1082         struct percpu_counter s_dirtyblocks_counter;
1083         struct blockgroup_lock *s_blockgroup_lock;
1084         struct proc_dir_entry *s_proc;
1085         struct kobject s_kobj;
1086         struct completion s_kobj_unregister;
1087
1088         /* Journaling */
1089         struct inode *s_journal_inode;
1090         struct journal_s *s_journal;
1091         struct list_head s_orphan;
1092         struct mutex s_orphan_lock;
1093         struct mutex s_resize_lock;
1094         unsigned long s_commit_interval;
1095         u32 s_max_batch_time;
1096         u32 s_min_batch_time;
1097         struct block_device *journal_bdev;
1098 #ifdef CONFIG_JBD2_DEBUG
1099         struct timer_list turn_ro_timer;        /* For turning read-only (crash simulation) */
1100         wait_queue_head_t ro_wait_queue;        /* For people waiting for the fs to go read-only */
1101 #endif
1102 #ifdef CONFIG_QUOTA
1103         char *s_qf_names[MAXQUOTAS];            /* Names of quota files with journalled quota */
1104         int s_jquota_fmt;                       /* Format of quota to use */
1105 #endif
1106         unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1107         struct rb_root system_blks;
1108
1109 #ifdef EXTENTS_STATS
1110         /* ext4 extents stats */
1111         unsigned long s_ext_min;
1112         unsigned long s_ext_max;
1113         unsigned long s_depth_max;
1114         spinlock_t s_ext_stats_lock;
1115         unsigned long s_ext_blocks;
1116         unsigned long s_ext_extents;
1117 #endif
1118
1119         /* for buddy allocator */
1120         struct ext4_group_info ***s_group_info;
1121         struct inode *s_buddy_cache;
1122         long s_blocks_reserved;
1123         spinlock_t s_reserve_lock;
1124         spinlock_t s_md_lock;
1125         tid_t s_last_transaction;
1126         unsigned short *s_mb_offsets;
1127         unsigned int *s_mb_maxs;
1128
1129         /* tunables */
1130         unsigned long s_stripe;
1131         unsigned int s_mb_stream_request;
1132         unsigned int s_mb_max_to_scan;
1133         unsigned int s_mb_min_to_scan;
1134         unsigned int s_mb_stats;
1135         unsigned int s_mb_order2_reqs;
1136         unsigned int s_mb_group_prealloc;
1137         unsigned int s_max_writeback_mb_bump;
1138         /* where last allocation was done - for stream allocation */
1139         unsigned long s_mb_last_group;
1140         unsigned long s_mb_last_start;
1141
1142         /* stats for buddy allocator */
1143         spinlock_t s_mb_pa_lock;
1144         atomic_t s_bal_reqs;    /* number of reqs with len > 1 */
1145         atomic_t s_bal_success; /* we found long enough chunks */
1146         atomic_t s_bal_allocated;       /* in blocks */
1147         atomic_t s_bal_ex_scanned;      /* total extents scanned */
1148         atomic_t s_bal_goals;   /* goal hits */
1149         atomic_t s_bal_breaks;  /* too long searches */
1150         atomic_t s_bal_2orders; /* 2^order hits */
1151         spinlock_t s_bal_lock;
1152         unsigned long s_mb_buddies_generated;
1153         unsigned long long s_mb_generation_time;
1154         atomic_t s_mb_lost_chunks;
1155         atomic_t s_mb_preallocated;
1156         atomic_t s_mb_discarded;
1157         atomic_t s_lock_busy;
1158
1159         /* locality groups */
1160         struct ext4_locality_group __percpu *s_locality_groups;
1161
1162         /* for write statistics */
1163         unsigned long s_sectors_written_start;
1164         u64 s_kbytes_written;
1165
1166         unsigned int s_log_groups_per_flex;
1167         struct flex_groups *s_flex_groups;
1168
1169         /* workqueue for dio unwritten */
1170         struct workqueue_struct *dio_unwritten_wq;
1171
1172         /* timer for periodic error stats printing */
1173         struct timer_list s_err_report;
1174 };
1175
1176 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1177 {
1178         return sb->s_fs_info;
1179 }
1180 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1181 {
1182         return container_of(inode, struct ext4_inode_info, vfs_inode);
1183 }
1184
1185 static inline struct timespec ext4_current_time(struct inode *inode)
1186 {
1187         return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1188                 current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1189 }
1190
1191 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1192 {
1193         return ino == EXT4_ROOT_INO ||
1194                 ino == EXT4_JOURNAL_INO ||
1195                 ino == EXT4_RESIZE_INO ||
1196                 (ino >= EXT4_FIRST_INO(sb) &&
1197                  ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1198 }
1199
1200 /*
1201  * Inode dynamic state flags
1202  */
1203 enum {
1204         EXT4_STATE_JDATA,               /* journaled data exists */
1205         EXT4_STATE_NEW,                 /* inode is newly created */
1206         EXT4_STATE_XATTR,               /* has in-inode xattrs */
1207         EXT4_STATE_NO_EXPAND,           /* No space for expansion */
1208         EXT4_STATE_DA_ALLOC_CLOSE,      /* Alloc DA blks on close */
1209         EXT4_STATE_EXT_MIGRATE,         /* Inode is migrating */
1210         EXT4_STATE_DIO_UNWRITTEN,       /* need convert on dio done*/
1211         EXT4_STATE_NEWENTRY,            /* File just added to dir */
1212 };
1213
1214 #define EXT4_INODE_BIT_FNS(name, field)                                 \
1215 static inline int ext4_test_inode_##name(struct inode *inode, int bit)  \
1216 {                                                                       \
1217         return test_bit(bit, &EXT4_I(inode)->i_##field);                \
1218 }                                                                       \
1219 static inline void ext4_set_inode_##name(struct inode *inode, int bit)  \
1220 {                                                                       \
1221         set_bit(bit, &EXT4_I(inode)->i_##field);                        \
1222 }                                                                       \
1223 static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1224 {                                                                       \
1225         clear_bit(bit, &EXT4_I(inode)->i_##field);                      \
1226 }
1227
1228 EXT4_INODE_BIT_FNS(flag, flags)
1229 EXT4_INODE_BIT_FNS(state, state_flags)
1230 #else
1231 /* Assume that user mode programs are passing in an ext4fs superblock, not
1232  * a kernel struct super_block.  This will allow us to call the feature-test
1233  * macros from user land. */
1234 #define EXT4_SB(sb)     (sb)
1235 #endif
1236
1237 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1238
1239 /*
1240  * Codes for operating systems
1241  */
1242 #define EXT4_OS_LINUX           0
1243 #define EXT4_OS_HURD            1
1244 #define EXT4_OS_MASIX           2
1245 #define EXT4_OS_FREEBSD         3
1246 #define EXT4_OS_LITES           4
1247
1248 /*
1249  * Revision levels
1250  */
1251 #define EXT4_GOOD_OLD_REV       0       /* The good old (original) format */
1252 #define EXT4_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
1253
1254 #define EXT4_CURRENT_REV        EXT4_GOOD_OLD_REV
1255 #define EXT4_MAX_SUPP_REV       EXT4_DYNAMIC_REV
1256
1257 #define EXT4_GOOD_OLD_INODE_SIZE 128
1258
1259 /*
1260  * Feature set definitions
1261  */
1262
1263 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)                        \
1264         ((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1265 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
1266         ((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1267 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)                      \
1268         ((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1269 #define EXT4_SET_COMPAT_FEATURE(sb,mask)                        \
1270         EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1271 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)                     \
1272         EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1273 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)                      \
1274         EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1275 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)                      \
1276         EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1277 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
1278         EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1279 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
1280         EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1281
1282 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC        0x0001
1283 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES       0x0002
1284 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL         0x0004
1285 #define EXT4_FEATURE_COMPAT_EXT_ATTR            0x0008
1286 #define EXT4_FEATURE_COMPAT_RESIZE_INODE        0x0010
1287 #define EXT4_FEATURE_COMPAT_DIR_INDEX           0x0020
1288
1289 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
1290 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
1291 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
1292 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1293 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM         0x0010
1294 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK        0x0020
1295 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE      0x0040
1296
1297 #define EXT4_FEATURE_INCOMPAT_COMPRESSION       0x0001
1298 #define EXT4_FEATURE_INCOMPAT_FILETYPE          0x0002
1299 #define EXT4_FEATURE_INCOMPAT_RECOVER           0x0004 /* Needs recovery */
1300 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008 /* Journal device */
1301 #define EXT4_FEATURE_INCOMPAT_META_BG           0x0010
1302 #define EXT4_FEATURE_INCOMPAT_EXTENTS           0x0040 /* extents support */
1303 #define EXT4_FEATURE_INCOMPAT_64BIT             0x0080
1304 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1305 #define EXT4_FEATURE_INCOMPAT_FLEX_BG           0x0200
1306 #define EXT4_FEATURE_INCOMPAT_EA_INODE          0x0400 /* EA in inode */
1307 #define EXT4_FEATURE_INCOMPAT_DIRDATA           0x1000 /* data in dirent */
1308
1309 #define EXT4_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
1310 #define EXT4_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1311                                          EXT4_FEATURE_INCOMPAT_RECOVER| \
1312                                          EXT4_FEATURE_INCOMPAT_META_BG| \
1313                                          EXT4_FEATURE_INCOMPAT_EXTENTS| \
1314                                          EXT4_FEATURE_INCOMPAT_64BIT| \
1315                                          EXT4_FEATURE_INCOMPAT_FLEX_BG)
1316 #define EXT4_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1317                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1318                                          EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1319                                          EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1320                                          EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1321                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1322                                          EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
1323
1324 /*
1325  * Default values for user and/or group using reserved blocks
1326  */
1327 #define EXT4_DEF_RESUID         0
1328 #define EXT4_DEF_RESGID         0
1329
1330 #define EXT4_DEF_INODE_READAHEAD_BLKS   32
1331
1332 /*
1333  * Default mount options
1334  */
1335 #define EXT4_DEFM_DEBUG         0x0001
1336 #define EXT4_DEFM_BSDGROUPS     0x0002
1337 #define EXT4_DEFM_XATTR_USER    0x0004
1338 #define EXT4_DEFM_ACL           0x0008
1339 #define EXT4_DEFM_UID16         0x0010
1340 #define EXT4_DEFM_JMODE         0x0060
1341 #define EXT4_DEFM_JMODE_DATA    0x0020
1342 #define EXT4_DEFM_JMODE_ORDERED 0x0040
1343 #define EXT4_DEFM_JMODE_WBACK   0x0060
1344
1345 /*
1346  * Default journal batch times
1347  */
1348 #define EXT4_DEF_MIN_BATCH_TIME 0
1349 #define EXT4_DEF_MAX_BATCH_TIME 15000 /* 15ms */
1350
1351 /*
1352  * Minimum number of groups in a flexgroup before we separate out
1353  * directories into the first block group of a flexgroup
1354  */
1355 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME 4
1356
1357 /*
1358  * Structure of a directory entry
1359  */
1360 #define EXT4_NAME_LEN 255
1361
1362 struct ext4_dir_entry {
1363         __le32  inode;                  /* Inode number */
1364         __le16  rec_len;                /* Directory entry length */
1365         __le16  name_len;               /* Name length */
1366         char    name[EXT4_NAME_LEN];    /* File name */
1367 };
1368
1369 /*
1370  * The new version of the directory entry.  Since EXT4 structures are
1371  * stored in intel byte order, and the name_len field could never be
1372  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1373  * file_type field.
1374  */
1375 struct ext4_dir_entry_2 {
1376         __le32  inode;                  /* Inode number */
1377         __le16  rec_len;                /* Directory entry length */
1378         __u8    name_len;               /* Name length */
1379         __u8    file_type;
1380         char    name[EXT4_NAME_LEN];    /* File name */
1381 };
1382
1383 /*
1384  * Ext4 directory file types.  Only the low 3 bits are used.  The
1385  * other bits are reserved for now.
1386  */
1387 #define EXT4_FT_UNKNOWN         0
1388 #define EXT4_FT_REG_FILE        1
1389 #define EXT4_FT_DIR             2
1390 #define EXT4_FT_CHRDEV          3
1391 #define EXT4_FT_BLKDEV          4
1392 #define EXT4_FT_FIFO            5
1393 #define EXT4_FT_SOCK            6
1394 #define EXT4_FT_SYMLINK         7
1395
1396 #define EXT4_FT_MAX             8
1397
1398 /*
1399  * EXT4_DIR_PAD defines the directory entries boundaries
1400  *
1401  * NOTE: It must be a multiple of 4
1402  */
1403 #define EXT4_DIR_PAD                    4
1404 #define EXT4_DIR_ROUND                  (EXT4_DIR_PAD - 1)
1405 #define EXT4_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT4_DIR_ROUND) & \
1406                                          ~EXT4_DIR_ROUND)
1407 #define EXT4_MAX_REC_LEN                ((1<<16)-1)
1408
1409 /*
1410  * Hash Tree Directory indexing
1411  * (c) Daniel Phillips, 2001
1412  */
1413
1414 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1415                                       EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1416                     ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
1417 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1418 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1419
1420 /* Legal values for the dx_root hash_version field: */
1421
1422 #define DX_HASH_LEGACY          0
1423 #define DX_HASH_HALF_MD4        1
1424 #define DX_HASH_TEA             2
1425 #define DX_HASH_LEGACY_UNSIGNED 3
1426 #define DX_HASH_HALF_MD4_UNSIGNED       4
1427 #define DX_HASH_TEA_UNSIGNED            5
1428
1429 #ifdef __KERNEL__
1430
1431 /* hash info structure used by the directory hash */
1432 struct dx_hash_info
1433 {
1434         u32             hash;
1435         u32             minor_hash;
1436         int             hash_version;
1437         u32             *seed;
1438 };
1439
1440 #define EXT4_HTREE_EOF  0x7fffffff
1441
1442 /*
1443  * Control parameters used by ext4_htree_next_block
1444  */
1445 #define HASH_NB_ALWAYS          1
1446
1447
1448 /*
1449  * Describe an inode's exact location on disk and in memory
1450  */
1451 struct ext4_iloc
1452 {
1453         struct buffer_head *bh;
1454         unsigned long offset;
1455         ext4_group_t block_group;
1456 };
1457
1458 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1459 {
1460         return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1461 }
1462
1463 /*
1464  * This structure is stuffed into the struct file's private_data field
1465  * for directories.  It is where we put information so that we can do
1466  * readdir operations in hash tree order.
1467  */
1468 struct dir_private_info {
1469         struct rb_root  root;
1470         struct rb_node  *curr_node;
1471         struct fname    *extra_fname;
1472         loff_t          last_pos;
1473         __u32           curr_hash;
1474         __u32           curr_minor_hash;
1475         __u32           next_hash;
1476 };
1477
1478 /* calculate the first block number of the group */
1479 static inline ext4_fsblk_t
1480 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1481 {
1482         return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1483                 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1484 }
1485
1486 /*
1487  * Special error return code only used by dx_probe() and its callers.
1488  */
1489 #define ERR_BAD_DX_DIR  -75000
1490
1491 void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
1492                         ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp);
1493
1494 extern struct proc_dir_entry *ext4_proc_root;
1495
1496 /*
1497  * Function prototypes
1498  */
1499
1500 /*
1501  * Ok, these declarations are also in <linux/kernel.h> but none of the
1502  * ext4 source programs needs to include it so they are duplicated here.
1503  */
1504 # define NORET_TYPE     /**/
1505 # define ATTRIB_NORET   __attribute__((noreturn))
1506 # define NORET_AND      noreturn,
1507
1508 /* bitmap.c */
1509 extern unsigned int ext4_count_free(struct buffer_head *, unsigned);
1510
1511 /* balloc.c */
1512 extern unsigned int ext4_block_group(struct super_block *sb,
1513                         ext4_fsblk_t blocknr);
1514 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1515                         ext4_fsblk_t blocknr);
1516 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1517 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1518                         ext4_group_t group);
1519 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1520                         ext4_fsblk_t goal, unsigned long *count, int *errp);
1521 extern int ext4_claim_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
1522 extern int ext4_has_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
1523 extern void ext4_add_groupblocks(handle_t *handle, struct super_block *sb,
1524                                 ext4_fsblk_t block, unsigned long count);
1525 extern ext4_fsblk_t ext4_count_free_blocks(struct super_block *);
1526 extern void ext4_check_blocks_bitmap(struct super_block *);
1527 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1528                                                     ext4_group_t block_group,
1529                                                     struct buffer_head ** bh);
1530 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1531 struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1532                                       ext4_group_t block_group);
1533 extern unsigned ext4_init_block_bitmap(struct super_block *sb,
1534                                        struct buffer_head *bh,
1535                                        ext4_group_t group,
1536                                        struct ext4_group_desc *desc);
1537 #define ext4_free_blocks_after_init(sb, group, desc)                    \
1538                 ext4_init_block_bitmap(sb, NULL, group, desc)
1539
1540 /* dir.c */
1541 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
1542                                   struct ext4_dir_entry_2 *,
1543                                   struct buffer_head *, unsigned int);
1544 #define ext4_check_dir_entry(dir, de, bh, offset) \
1545         __ext4_check_dir_entry(__func__, __LINE__, (dir), (de), (bh), (offset))
1546 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1547                                     __u32 minor_hash,
1548                                     struct ext4_dir_entry_2 *dirent);
1549 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
1550
1551 /* fsync.c */
1552 extern int ext4_sync_file(struct file *, int);
1553
1554 /* hash.c */
1555 extern int ext4fs_dirhash(const char *name, int len, struct
1556                           dx_hash_info *hinfo);
1557
1558 /* ialloc.c */
1559 extern struct inode *ext4_new_inode(handle_t *, struct inode *, int,
1560                                     const struct qstr *qstr, __u32 goal);
1561 extern void ext4_free_inode(handle_t *, struct inode *);
1562 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
1563 extern unsigned long ext4_count_free_inodes(struct super_block *);
1564 extern unsigned long ext4_count_dirs(struct super_block *);
1565 extern void ext4_check_inodes_bitmap(struct super_block *);
1566 extern unsigned ext4_init_inode_bitmap(struct super_block *sb,
1567                                        struct buffer_head *bh,
1568                                        ext4_group_t group,
1569                                        struct ext4_group_desc *desc);
1570 extern void mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
1571
1572 /* mballoc.c */
1573 extern long ext4_mb_stats;
1574 extern long ext4_mb_max_to_scan;
1575 extern int ext4_mb_init(struct super_block *, int);
1576 extern int ext4_mb_release(struct super_block *);
1577 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
1578                                 struct ext4_allocation_request *, int *);
1579 extern int ext4_mb_reserve_blocks(struct super_block *, int);
1580 extern void ext4_discard_preallocations(struct inode *);
1581 extern int __init init_ext4_mballoc(void);
1582 extern void exit_ext4_mballoc(void);
1583 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
1584                              struct buffer_head *bh, ext4_fsblk_t block,
1585                              unsigned long count, int flags);
1586 extern int ext4_mb_add_groupinfo(struct super_block *sb,
1587                 ext4_group_t i, struct ext4_group_desc *desc);
1588 extern int ext4_mb_get_buddy_cache_lock(struct super_block *, ext4_group_t);
1589 extern void ext4_mb_put_buddy_cache_lock(struct super_block *,
1590                                                 ext4_group_t, int);
1591 /* inode.c */
1592 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
1593                                                 ext4_lblk_t, int, int *);
1594 struct buffer_head *ext4_bread(handle_t *, struct inode *,
1595                                                 ext4_lblk_t, int, int *);
1596 int ext4_get_block(struct inode *inode, sector_t iblock,
1597                                 struct buffer_head *bh_result, int create);
1598
1599 extern struct inode *ext4_iget(struct super_block *, unsigned long);
1600 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
1601 extern int  ext4_setattr(struct dentry *, struct iattr *);
1602 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
1603                                 struct kstat *stat);
1604 extern void ext4_delete_inode(struct inode *);
1605 extern int  ext4_sync_inode(handle_t *, struct inode *);
1606 extern void ext4_dirty_inode(struct inode *);
1607 extern int ext4_change_inode_journal_flag(struct inode *, int);
1608 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
1609 extern int ext4_can_truncate(struct inode *inode);
1610 extern void ext4_truncate(struct inode *);
1611 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
1612 extern void ext4_set_inode_flags(struct inode *);
1613 extern void ext4_get_inode_flags(struct ext4_inode_info *);
1614 extern int ext4_alloc_da_blocks(struct inode *inode);
1615 extern void ext4_set_aops(struct inode *inode);
1616 extern int ext4_writepage_trans_blocks(struct inode *);
1617 extern int ext4_meta_trans_blocks(struct inode *, int nrblocks, int idxblocks);
1618 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
1619 extern int ext4_block_truncate_page(handle_t *handle,
1620                 struct address_space *mapping, loff_t from);
1621 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
1622 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
1623 extern int flush_completed_IO(struct inode *inode);
1624 extern void ext4_da_update_reserve_space(struct inode *inode,
1625                                         int used, int quota_claim);
1626 /* ioctl.c */
1627 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
1628 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
1629
1630 /* migrate.c */
1631 extern int ext4_ext_migrate(struct inode *);
1632
1633 /* namei.c */
1634 extern unsigned int ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize);
1635 extern __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize);
1636 extern int ext4_orphan_add(handle_t *, struct inode *);
1637 extern int ext4_orphan_del(handle_t *, struct inode *);
1638 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1639                                 __u32 start_minor_hash, __u32 *next_hash);
1640
1641 /* resize.c */
1642 extern int ext4_group_add(struct super_block *sb,
1643                                 struct ext4_new_group_data *input);
1644 extern int ext4_group_extend(struct super_block *sb,
1645                                 struct ext4_super_block *es,
1646                                 ext4_fsblk_t n_blocks_count);
1647
1648 /* super.c */
1649 extern void __ext4_error(struct super_block *, const char *, unsigned int,
1650                          const char *, ...)
1651         __attribute__ ((format (printf, 4, 5)));
1652 #define ext4_error(sb, message...)      __ext4_error(sb, __func__,      \
1653                                                      __LINE__, ## message)
1654 extern void ext4_error_inode(struct inode *, const char *, unsigned int,
1655                              ext4_fsblk_t, const char *, ...)
1656         __attribute__ ((format (printf, 5, 6)));
1657 extern void ext4_error_file(struct file *, const char *, unsigned int,
1658                             const char *, ...)
1659         __attribute__ ((format (printf, 4, 5)));
1660 extern void __ext4_std_error(struct super_block *, const char *,
1661                              unsigned int, int);
1662 extern void __ext4_abort(struct super_block *, const char *, unsigned int,
1663                        const char *, ...)
1664         __attribute__ ((format (printf, 4, 5)));
1665 #define ext4_abort(sb, message...)      __ext4_abort(sb, __func__, \
1666                                                        __LINE__, ## message)
1667 extern void __ext4_warning(struct super_block *, const char *, unsigned int,
1668                           const char *, ...)
1669         __attribute__ ((format (printf, 4, 5)));
1670 #define ext4_warning(sb, message...)    __ext4_warning(sb, __func__, \
1671                                                        __LINE__, ## message)
1672 extern void ext4_msg(struct super_block *, const char *, const char *, ...)
1673         __attribute__ ((format (printf, 3, 4)));
1674 extern void __ext4_grp_locked_error(const char *, unsigned int, \
1675                                     struct super_block *, ext4_group_t, \
1676                                     unsigned long, ext4_fsblk_t, \
1677                                     const char *, ...)
1678         __attribute__ ((format (printf, 7, 8)));
1679 #define ext4_grp_locked_error(sb, grp, message...) \
1680         __ext4_grp_locked_error(__func__, __LINE__, (sb), (grp), ## message)
1681 extern void ext4_update_dynamic_rev(struct super_block *sb);
1682 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
1683                                         __u32 compat);
1684 extern int ext4_update_rocompat_feature(handle_t *handle,
1685                                         struct super_block *sb, __u32 rocompat);
1686 extern int ext4_update_incompat_feature(handle_t *handle,
1687                                         struct super_block *sb, __u32 incompat);
1688 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
1689                                       struct ext4_group_desc *bg);
1690 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
1691                                       struct ext4_group_desc *bg);
1692 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
1693                                      struct ext4_group_desc *bg);
1694 extern __u32 ext4_free_blks_count(struct super_block *sb,
1695                                 struct ext4_group_desc *bg);
1696 extern __u32 ext4_free_inodes_count(struct super_block *sb,
1697                                  struct ext4_group_desc *bg);
1698 extern __u32 ext4_used_dirs_count(struct super_block *sb,
1699                                 struct ext4_group_desc *bg);
1700 extern __u32 ext4_itable_unused_count(struct super_block *sb,
1701                                    struct ext4_group_desc *bg);
1702 extern void ext4_block_bitmap_set(struct super_block *sb,
1703                                   struct ext4_group_desc *bg, ext4_fsblk_t blk);
1704 extern void ext4_inode_bitmap_set(struct super_block *sb,
1705                                   struct ext4_group_desc *bg, ext4_fsblk_t blk);
1706 extern void ext4_inode_table_set(struct super_block *sb,
1707                                  struct ext4_group_desc *bg, ext4_fsblk_t blk);
1708 extern void ext4_free_blks_set(struct super_block *sb,
1709                                struct ext4_group_desc *bg, __u32 count);
1710 extern void ext4_free_inodes_set(struct super_block *sb,
1711                                 struct ext4_group_desc *bg, __u32 count);
1712 extern void ext4_used_dirs_set(struct super_block *sb,
1713                                 struct ext4_group_desc *bg, __u32 count);
1714 extern void ext4_itable_unused_set(struct super_block *sb,
1715                                    struct ext4_group_desc *bg, __u32 count);
1716 extern __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 group,
1717                                    struct ext4_group_desc *gdp);
1718 extern int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 group,
1719                                        struct ext4_group_desc *gdp);
1720
1721 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
1722 {
1723         return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
1724                 le32_to_cpu(es->s_blocks_count_lo);
1725 }
1726
1727 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
1728 {
1729         return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
1730                 le32_to_cpu(es->s_r_blocks_count_lo);
1731 }
1732
1733 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
1734 {
1735         return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
1736                 le32_to_cpu(es->s_free_blocks_count_lo);
1737 }
1738
1739 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
1740                                          ext4_fsblk_t blk)
1741 {
1742         es->s_blocks_count_lo = cpu_to_le32((u32)blk);
1743         es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
1744 }
1745
1746 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
1747                                               ext4_fsblk_t blk)
1748 {
1749         es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
1750         es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
1751 }
1752
1753 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
1754                                            ext4_fsblk_t blk)
1755 {
1756         es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
1757         es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
1758 }
1759
1760 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
1761 {
1762         if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
1763                 return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
1764                         le32_to_cpu(raw_inode->i_size_lo);
1765         else
1766                 return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
1767 }
1768
1769 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
1770 {
1771         raw_inode->i_size_lo = cpu_to_le32(i_size);
1772         raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
1773 }
1774
1775 static inline
1776 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
1777                                             ext4_group_t group)
1778 {
1779          struct ext4_group_info ***grp_info;
1780          long indexv, indexh;
1781          grp_info = EXT4_SB(sb)->s_group_info;
1782          indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
1783          indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
1784          return grp_info[indexv][indexh];
1785 }
1786
1787 /*
1788  * Reading s_groups_count requires using smp_rmb() afterwards.  See
1789  * the locking protocol documented in the comments of ext4_group_add()
1790  * in resize.c
1791  */
1792 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
1793 {
1794         ext4_group_t    ngroups = EXT4_SB(sb)->s_groups_count;
1795
1796         smp_rmb();
1797         return ngroups;
1798 }
1799
1800 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
1801                                              ext4_group_t block_group)
1802 {
1803         return block_group >> sbi->s_log_groups_per_flex;
1804 }
1805
1806 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
1807 {
1808         return 1 << sbi->s_log_groups_per_flex;
1809 }
1810
1811 #define ext4_std_error(sb, errno)                               \
1812 do {                                                            \
1813         if ((errno))                                            \
1814                 __ext4_std_error((sb), __func__, __LINE__, (errno));    \
1815 } while (0)
1816
1817 #ifdef CONFIG_SMP
1818 /* Each CPU can accumulate percpu_counter_batch blocks in their local
1819  * counters. So we need to make sure we have free blocks more
1820  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
1821  */
1822 #define EXT4_FREEBLOCKS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
1823 #else
1824 #define EXT4_FREEBLOCKS_WATERMARK 0
1825 #endif
1826
1827 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
1828 {
1829         /*
1830          * XXX: replace with spinlock if seen contended -bzzz
1831          */
1832         down_write(&EXT4_I(inode)->i_data_sem);
1833         if (newsize > EXT4_I(inode)->i_disksize)
1834                 EXT4_I(inode)->i_disksize = newsize;
1835         up_write(&EXT4_I(inode)->i_data_sem);
1836         return ;
1837 }
1838
1839 struct ext4_group_info {
1840         unsigned long   bb_state;
1841         struct rb_root  bb_free_root;
1842         ext4_grpblk_t   bb_first_free;  /* first free block */
1843         ext4_grpblk_t   bb_free;        /* total free blocks */
1844         ext4_grpblk_t   bb_fragments;   /* nr of freespace fragments */
1845         ext4_grpblk_t   bb_largest_free_order;/* order of largest frag in BG */
1846         struct          list_head bb_prealloc_list;
1847 #ifdef DOUBLE_CHECK
1848         void            *bb_bitmap;
1849 #endif
1850         struct rw_semaphore alloc_sem;
1851         ext4_grpblk_t   bb_counters[];  /* Nr of free power-of-two-block
1852                                          * regions, index is order.
1853                                          * bb_counters[3] = 5 means
1854                                          * 5 free 8-block regions. */
1855 };
1856
1857 #define EXT4_GROUP_INFO_NEED_INIT_BIT   0
1858
1859 #define EXT4_MB_GRP_NEED_INIT(grp)      \
1860         (test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
1861
1862 #define EXT4_MAX_CONTENTION             8
1863 #define EXT4_CONTENTION_THRESHOLD       2
1864
1865 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
1866                                               ext4_group_t group)
1867 {
1868         return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
1869 }
1870
1871 /*
1872  * Returns true if the filesystem is busy enough that attempts to
1873  * access the block group locks has run into contention.
1874  */
1875 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
1876 {
1877         return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
1878 }
1879
1880 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
1881 {
1882         spinlock_t *lock = ext4_group_lock_ptr(sb, group);
1883         if (spin_trylock(lock))
1884                 /*
1885                  * We're able to grab the lock right away, so drop the
1886                  * lock contention counter.
1887                  */
1888                 atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
1889         else {
1890                 /*
1891                  * The lock is busy, so bump the contention counter,
1892                  * and then wait on the spin lock.
1893                  */
1894                 atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
1895                                   EXT4_MAX_CONTENTION);
1896                 spin_lock(lock);
1897         }
1898 }
1899
1900 static inline void ext4_unlock_group(struct super_block *sb,
1901                                         ext4_group_t group)
1902 {
1903         spin_unlock(ext4_group_lock_ptr(sb, group));
1904 }
1905
1906 static inline void ext4_mark_super_dirty(struct super_block *sb)
1907 {
1908         if (EXT4_SB(sb)->s_journal == NULL)
1909                 sb->s_dirt =1;
1910 }
1911
1912 /*
1913  * Inodes and files operations
1914  */
1915
1916 /* dir.c */
1917 extern const struct file_operations ext4_dir_operations;
1918
1919 /* file.c */
1920 extern const struct inode_operations ext4_file_inode_operations;
1921 extern const struct file_operations ext4_file_operations;
1922
1923 /* namei.c */
1924 extern const struct inode_operations ext4_dir_inode_operations;
1925 extern const struct inode_operations ext4_special_inode_operations;
1926 extern struct dentry *ext4_get_parent(struct dentry *child);
1927
1928 /* symlink.c */
1929 extern const struct inode_operations ext4_symlink_inode_operations;
1930 extern const struct inode_operations ext4_fast_symlink_inode_operations;
1931
1932 /* block_validity */
1933 extern void ext4_release_system_zone(struct super_block *sb);
1934 extern int ext4_setup_system_zone(struct super_block *sb);
1935 extern int __init init_ext4_system_zone(void);
1936 extern void exit_ext4_system_zone(void);
1937 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
1938                                  ext4_fsblk_t start_blk,
1939                                  unsigned int count);
1940
1941 /* extents.c */
1942 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
1943 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
1944 extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks,
1945                                        int chunk);
1946 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
1947                                struct ext4_map_blocks *map, int flags);
1948 extern void ext4_ext_truncate(struct inode *);
1949 extern void ext4_ext_init(struct super_block *);
1950 extern void ext4_ext_release(struct super_block *);
1951 extern long ext4_fallocate(struct inode *inode, int mode, loff_t offset,
1952                           loff_t len);
1953 extern int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
1954                           ssize_t len);
1955 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
1956                            struct ext4_map_blocks *map, int flags);
1957 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
1958                         __u64 start, __u64 len);
1959 /* move_extent.c */
1960 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
1961                              __u64 start_orig, __u64 start_donor,
1962                              __u64 len, __u64 *moved_len);
1963
1964
1965 /* BH_Uninit flag: blocks are allocated but uninitialized on disk */
1966 enum ext4_state_bits {
1967         BH_Uninit       /* blocks are allocated but uninitialized on disk */
1968           = BH_JBDPrivateStart,
1969 };
1970
1971 BUFFER_FNS(Uninit, uninit)
1972 TAS_BUFFER_FNS(Uninit, uninit)
1973
1974 /*
1975  * Add new method to test wether block and inode bitmaps are properly
1976  * initialized. With uninit_bg reading the block from disk is not enough
1977  * to mark the bitmap uptodate. We need to also zero-out the bitmap
1978  */
1979 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
1980
1981 static inline int bitmap_uptodate(struct buffer_head *bh)
1982 {
1983         return (buffer_uptodate(bh) &&
1984                         test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
1985 }
1986 static inline void set_bitmap_uptodate(struct buffer_head *bh)
1987 {
1988         set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
1989 }
1990
1991 #define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
1992
1993 #endif  /* __KERNEL__ */
1994
1995 #endif  /* _EXT4_H */