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, block, fmt, a...)                         \
  66         ext4_error_file((file), __func__, __LINE__, (block), (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
 172 /*
 173  * Flags for ext4_io_end->flags
 174  */
 175 #define EXT4_IO_END_UNWRITTEN   0x0001
 176 #define EXT4_IO_END_ERROR       0x0002
 177
 178 struct ext4_io_page {
 179         struct page     *p_page;
 180         atomic_t        p_count;
 181 };
 182
 183 #define MAX_IO_PAGES 128
 184
 185 typedef struct ext4_io_end {
 186         struct list_head        list;           /* per-file finished IO list */
 187         struct inode            *inode;         /* file being written to */
 188         unsigned int            flag;           /* unwritten or not */
 189         struct page             *page;          /* page struct for buffer write */
 190         loff_t                  offset;         /* offset in the file */
 191         ssize_t                 size;           /* size of the extent */
 192         struct work_struct      work;           /* data work queue */
 193         struct kiocb            *iocb;          /* iocb struct for AIO */
 194         int                     result;         /* error value for AIO */
 195         int                     num_io_pages;
 196         struct ext4_io_page     *pages[MAX_IO_PAGES];
 197 } ext4_io_end_t;
 198
 199 struct ext4_io_submit {
 200         int                     io_op;
 201         struct bio              *io_bio;
 202         ext4_io_end_t           *io_end;
 203         struct ext4_io_page     *io_page;
 204         sector_t                io_next_block;
 205 };
 206
 207 /*
 208  * Special inodes numbers
 209  */
 210 #define EXT4_BAD_INO             1      /* Bad blocks inode */
 211 #define EXT4_ROOT_INO            2      /* Root inode */
 212 #define EXT4_BOOT_LOADER_INO     5      /* Boot loader inode */
 213 #define EXT4_UNDEL_DIR_INO       6      /* Undelete directory inode */
 214 #define EXT4_RESIZE_INO          7      /* Reserved group descriptors inode */
 215 #define EXT4_JOURNAL_INO         8      /* Journal inode */
 216
 217 /* First non-reserved inode for old ext4 filesystems */
 218 #define EXT4_GOOD_OLD_FIRST_INO 11
 219
 220 /*
 221  * Maximal count of links to a file
 222  */
 223 #define EXT4_LINK_MAX           65000
 224
 225 /*
 226  * Macro-instructions used to manage several block sizes
 227  */
 228 #define EXT4_MIN_BLOCK_SIZE             1024
 229 #define EXT4_MAX_BLOCK_SIZE             65536
 230 #define EXT4_MIN_BLOCK_LOG_SIZE         10
 231 #define EXT4_MAX_BLOCK_LOG_SIZE         16
 232 #ifdef __KERNEL__
 233 # define EXT4_BLOCK_SIZE(s)             ((s)->s_blocksize)
 234 #else
 235 # define EXT4_BLOCK_SIZE(s)             (EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
 236 #endif
 237 #define EXT4_ADDR_PER_BLOCK(s)          (EXT4_BLOCK_SIZE(s) / sizeof(__u32))
 238 #ifdef __KERNEL__
 239 # define EXT4_BLOCK_SIZE_BITS(s)        ((s)->s_blocksize_bits)
 240 #else
 241 # define EXT4_BLOCK_SIZE_BITS(s)        ((s)->s_log_block_size + 10)
 242 #endif
 243 #ifdef __KERNEL__
 244 #define EXT4_ADDR_PER_BLOCK_BITS(s)     (EXT4_SB(s)->s_addr_per_block_bits)
 245 #define EXT4_INODE_SIZE(s)              (EXT4_SB(s)->s_inode_size)
 246 #define EXT4_FIRST_INO(s)               (EXT4_SB(s)->s_first_ino)
 247 #else
 248 #define EXT4_INODE_SIZE(s)      (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
 249                                  EXT4_GOOD_OLD_INODE_SIZE : \
 250                                  (s)->s_inode_size)
 251 #define EXT4_FIRST_INO(s)       (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
 252                                  EXT4_GOOD_OLD_FIRST_INO : \
 253                                  (s)->s_first_ino)
 254 #endif
 255 #define EXT4_BLOCK_ALIGN(size, blkbits)         ALIGN((size), (1 << (blkbits)))
 256
 257 /*
 258  * Structure of a blocks group descriptor
 259  */
 260 struct ext4_group_desc
 261 {
 262         __le32  bg_block_bitmap_lo;     /* Blocks bitmap block */
 263         __le32  bg_inode_bitmap_lo;     /* Inodes bitmap block */
 264         __le32  bg_inode_table_lo;      /* Inodes table block */
 265         __le16  bg_free_blocks_count_lo;/* Free blocks count */
 266         __le16  bg_free_inodes_count_lo;/* Free inodes count */
 267         __le16  bg_used_dirs_count_lo;  /* Directories count */
 268         __le16  bg_flags;               /* EXT4_BG_flags (INODE_UNINIT, etc) */
 269         __u32   bg_reserved[2];         /* Likely block/inode bitmap checksum */
 270         __le16  bg_itable_unused_lo;    /* Unused inodes count */
 271         __le16  bg_checksum;            /* crc16(sb_uuid+group+desc) */
 272         __le32  bg_block_bitmap_hi;     /* Blocks bitmap block MSB */
 273         __le32  bg_inode_bitmap_hi;     /* Inodes bitmap block MSB */
 274         __le32  bg_inode_table_hi;      /* Inodes table block MSB */
 275         __le16  bg_free_blocks_count_hi;/* Free blocks count MSB */
 276         __le16  bg_free_inodes_count_hi;/* Free inodes count MSB */
 277         __le16  bg_used_dirs_count_hi;  /* Directories count MSB */
 278         __le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
 279         __u32   bg_reserved2[3];
 280 };
 281
 282 /*
 283  * Structure of a flex block group info
 284  */
 285
 286 struct flex_groups {
 287         atomic_t free_inodes;
 288         atomic_t free_blocks;
 289         atomic_t used_dirs;
 290 };
 291
 292 #define EXT4_BG_INODE_UNINIT    0x0001 /* Inode table/bitmap not in use */
 293 #define EXT4_BG_BLOCK_UNINIT    0x0002 /* Block bitmap not in use */
 294 #define EXT4_BG_INODE_ZEROED    0x0004 /* On-disk itable initialized to zero */
 295
 296 /*
 297  * Macro-instructions used to manage group descriptors
 298  */
 299 #define EXT4_MIN_DESC_SIZE              32
 300 #define EXT4_MIN_DESC_SIZE_64BIT        64
 301 #define EXT4_MAX_DESC_SIZE              EXT4_MIN_BLOCK_SIZE
 302 #define EXT4_DESC_SIZE(s)               (EXT4_SB(s)->s_desc_size)
 303 #ifdef __KERNEL__
 304 # define EXT4_BLOCKS_PER_GROUP(s)       (EXT4_SB(s)->s_blocks_per_group)
 305 # define EXT4_DESC_PER_BLOCK(s)         (EXT4_SB(s)->s_desc_per_block)
 306 # define EXT4_INODES_PER_GROUP(s)       (EXT4_SB(s)->s_inodes_per_group)
 307 # define EXT4_DESC_PER_BLOCK_BITS(s)    (EXT4_SB(s)->s_desc_per_block_bits)
 308 #else
 309 # define EXT4_BLOCKS_PER_GROUP(s)       ((s)->s_blocks_per_group)
 310 # define EXT4_DESC_PER_BLOCK(s)         (EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
 311 # define EXT4_INODES_PER_GROUP(s)       ((s)->s_inodes_per_group)
 312 #endif
 313
 314 /*
 315  * Constants relative to the data blocks
 316  */
 317 #define EXT4_NDIR_BLOCKS                12
 318 #define EXT4_IND_BLOCK                  EXT4_NDIR_BLOCKS
 319 #define EXT4_DIND_BLOCK                 (EXT4_IND_BLOCK + 1)
 320 #define EXT4_TIND_BLOCK                 (EXT4_DIND_BLOCK + 1)
 321 #define EXT4_N_BLOCKS                   (EXT4_TIND_BLOCK + 1)
 322
 323 /*
 324  * Inode flags
 325  */
 326 #define EXT4_SECRM_FL                   0x00000001 /* Secure deletion */
 327 #define EXT4_UNRM_FL                    0x00000002 /* Undelete */
 328 #define EXT4_COMPR_FL                   0x00000004 /* Compress file */
 329 #define EXT4_SYNC_FL                    0x00000008 /* Synchronous updates */
 330 #define EXT4_IMMUTABLE_FL               0x00000010 /* Immutable file */
 331 #define EXT4_APPEND_FL                  0x00000020 /* writes to file may only append */
 332 #define EXT4_NODUMP_FL                  0x00000040 /* do not dump file */
 333 #define EXT4_NOATIME_FL                 0x00000080 /* do not update atime */
 334 /* Reserved for compression usage... */
 335 #define EXT4_DIRTY_FL                   0x00000100
 336 #define EXT4_COMPRBLK_FL                0x00000200 /* One or more compressed clusters */
 337 #define EXT4_NOCOMPR_FL                 0x00000400 /* Don't compress */
 338 #define EXT4_ECOMPR_FL                  0x00000800 /* Compression error */
 339 /* End compression flags --- maybe not all used */
 340 #define EXT4_INDEX_FL                   0x00001000 /* hash-indexed directory */
 341 #define EXT4_IMAGIC_FL                  0x00002000 /* AFS directory */
 342 #define EXT4_JOURNAL_DATA_FL            0x00004000 /* file data should be journaled */
 343 #define EXT4_NOTAIL_FL                  0x00008000 /* file tail should not be merged */
 344 #define EXT4_DIRSYNC_FL                 0x00010000 /* dirsync behaviour (directories only) */
 345 #define EXT4_TOPDIR_FL                  0x00020000 /* Top of directory hierarchies*/
 346 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
 347 #define EXT4_EXTENTS_FL                 0x00080000 /* Inode uses extents */
 348 #define EXT4_EA_INODE_FL                0x00200000 /* Inode used for large EA */
 349 #define EXT4_EOFBLOCKS_FL               0x00400000 /* Blocks allocated beyond EOF */
 350 #define EXT4_RESERVED_FL                0x80000000 /* reserved for ext4 lib */
 351
 352 #define EXT4_FL_USER_VISIBLE            0x004BDFFF /* User visible flags */
 353 #define EXT4_FL_USER_MODIFIABLE         0x004B80FF /* User modifiable flags */
 354
 355 /* Flags that should be inherited by new inodes from their parent. */
 356 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
 357                            EXT4_SYNC_FL | EXT4_IMMUTABLE_FL | EXT4_APPEND_FL |\
 358                            EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
 359                            EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
 360                            EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
 361
 362 /* Flags that are appropriate for regular files (all but dir-specific ones). */
 363 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
 364
 365 /* Flags that are appropriate for non-directories/regular files. */
 366 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
 367
 368 /* Mask out flags that are inappropriate for the given type of inode. */
 369 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
 370 {
 371         if (S_ISDIR(mode))
 372                 return flags;
 373         else if (S_ISREG(mode))
 374                 return flags & EXT4_REG_FLMASK;
 375         else
 376                 return flags & EXT4_OTHER_FLMASK;
 377 }
 378
 379 /*
 380  * Inode flags used for atomic set/get
 381  */
 382 enum {
 383         EXT4_INODE_SECRM        = 0,    /* Secure deletion */
 384         EXT4_INODE_UNRM         = 1,    /* Undelete */
 385         EXT4_INODE_COMPR        = 2,    /* Compress file */
 386         EXT4_INODE_SYNC         = 3,    /* Synchronous updates */
 387         EXT4_INODE_IMMUTABLE    = 4,    /* Immutable file */
 388         EXT4_INODE_APPEND       = 5,    /* writes to file may only append */
 389         EXT4_INODE_NODUMP       = 6,    /* do not dump file */
 390         EXT4_INODE_NOATIME      = 7,    /* do not update atime */
 391 /* Reserved for compression usage... */
 392         EXT4_INODE_DIRTY        = 8,
 393         EXT4_INODE_COMPRBLK     = 9,    /* One or more compressed clusters */
 394         EXT4_INODE_NOCOMPR      = 10,   /* Don't compress */
 395         EXT4_INODE_ECOMPR       = 11,   /* Compression error */
 396 /* End compression flags --- maybe not all used */
 397         EXT4_INODE_INDEX        = 12,   /* hash-indexed directory */
 398         EXT4_INODE_IMAGIC       = 13,   /* AFS directory */
 399         EXT4_INODE_JOURNAL_DATA = 14,   /* file data should be journaled */
 400         EXT4_INODE_NOTAIL       = 15,   /* file tail should not be merged */
 401         EXT4_INODE_DIRSYNC      = 16,   /* dirsync behaviour (directories only) */
 402         EXT4_INODE_TOPDIR       = 17,   /* Top of directory hierarchies*/
 403         EXT4_INODE_HUGE_FILE    = 18,   /* Set to each huge file */
 404         EXT4_INODE_EXTENTS      = 19,   /* Inode uses extents */
 405         EXT4_INODE_EA_INODE     = 21,   /* Inode used for large EA */
 406         EXT4_INODE_EOFBLOCKS    = 22,   /* Blocks allocated beyond EOF */
 407         EXT4_INODE_RESERVED     = 31,   /* reserved for ext4 lib */
 408 };
 409
 410 #define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1 << EXT4_INODE_##FLAG))
 411 #define CHECK_FLAG_VALUE(FLAG) if (!TEST_FLAG_VALUE(FLAG)) { \
 412         printk(KERN_EMERG "EXT4 flag fail: " #FLAG ": %d %d\n", \
 413                 EXT4_##FLAG##_FL, EXT4_INODE_##FLAG); BUG_ON(1); }
 414
 415 /*
 416  * Since it's pretty easy to mix up bit numbers and hex values, and we
 417  * can't do a compile-time test for ENUM values, we use a run-time
 418  * test to make sure that EXT4_XXX_FL is consistent with respect to
 419  * EXT4_INODE_XXX.  If all is well the printk and BUG_ON will all drop
 420  * out so it won't cost any extra space in the compiled kernel image.
 421  * But it's important that these values are the same, since we are
 422  * using EXT4_INODE_XXX to test for the flag values, but EXT4_XX_FL
 423  * must be consistent with the values of FS_XXX_FL defined in
 424  * include/linux/fs.h and the on-disk values found in ext2, ext3, and
 425  * ext4 filesystems, and of course the values defined in e2fsprogs.
 426  *
 427  * It's not paranoia if the Murphy's Law really *is* out to get you.  :-)
 428  */
 429 static inline void ext4_check_flag_values(void)
 430 {
 431         CHECK_FLAG_VALUE(SECRM);
 432         CHECK_FLAG_VALUE(UNRM);
 433         CHECK_FLAG_VALUE(COMPR);
 434         CHECK_FLAG_VALUE(SYNC);
 435         CHECK_FLAG_VALUE(IMMUTABLE);
 436         CHECK_FLAG_VALUE(APPEND);
 437         CHECK_FLAG_VALUE(NODUMP);
 438         CHECK_FLAG_VALUE(NOATIME);
 439         CHECK_FLAG_VALUE(DIRTY);
 440         CHECK_FLAG_VALUE(COMPRBLK);
 441         CHECK_FLAG_VALUE(NOCOMPR);
 442         CHECK_FLAG_VALUE(ECOMPR);
 443         CHECK_FLAG_VALUE(INDEX);
 444         CHECK_FLAG_VALUE(IMAGIC);
 445         CHECK_FLAG_VALUE(JOURNAL_DATA);
 446         CHECK_FLAG_VALUE(NOTAIL);
 447         CHECK_FLAG_VALUE(DIRSYNC);
 448         CHECK_FLAG_VALUE(TOPDIR);
 449         CHECK_FLAG_VALUE(HUGE_FILE);
 450         CHECK_FLAG_VALUE(EXTENTS);
 451         CHECK_FLAG_VALUE(EA_INODE);
 452         CHECK_FLAG_VALUE(EOFBLOCKS);
 453         CHECK_FLAG_VALUE(RESERVED);
 454 }
 455
 456 /* Used to pass group descriptor data when online resize is done */
 457 struct ext4_new_group_input {
 458         __u32 group;            /* Group number for this data */
 459         __u64 block_bitmap;     /* Absolute block number of block bitmap */
 460         __u64 inode_bitmap;     /* Absolute block number of inode bitmap */
 461         __u64 inode_table;      /* Absolute block number of inode table start */
 462         __u32 blocks_count;     /* Total number of blocks in this group */
 463         __u16 reserved_blocks;  /* Number of reserved blocks in this group */
 464         __u16 unused;
 465 };
 466
 467 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
 468 struct compat_ext4_new_group_input {
 469         u32 group;
 470         compat_u64 block_bitmap;
 471         compat_u64 inode_bitmap;
 472         compat_u64 inode_table;
 473         u32 blocks_count;
 474         u16 reserved_blocks;
 475         u16 unused;
 476 };
 477 #endif
 478
 479 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
 480 struct ext4_new_group_data {
 481         __u32 group;
 482         __u64 block_bitmap;
 483         __u64 inode_bitmap;
 484         __u64 inode_table;
 485         __u32 blocks_count;
 486         __u16 reserved_blocks;
 487         __u16 unused;
 488         __u32 free_blocks_count;
 489 };
 490
 491 /*
 492  * Flags used by ext4_map_blocks()
 493  */
 494         /* Allocate any needed blocks and/or convert an unitialized
 495            extent to be an initialized ext4 */
 496 #define EXT4_GET_BLOCKS_CREATE                  0x0001
 497         /* Request the creation of an unitialized extent */
 498 #define EXT4_GET_BLOCKS_UNINIT_EXT              0x0002
 499 #define EXT4_GET_BLOCKS_CREATE_UNINIT_EXT       (EXT4_GET_BLOCKS_UNINIT_EXT|\
 500                                                  EXT4_GET_BLOCKS_CREATE)
 501         /* Caller is from the delayed allocation writeout path,
 502            so set the magic i_delalloc_reserve_flag after taking the
 503            inode allocation semaphore for */
 504 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE        0x0004
 505         /* caller is from the direct IO path, request to creation of an
 506         unitialized extents if not allocated, split the uninitialized
 507         extent if blocks has been preallocated already*/
 508 #define EXT4_GET_BLOCKS_PRE_IO                  0x0008
 509 #define EXT4_GET_BLOCKS_CONVERT                 0x0010
 510 #define EXT4_GET_BLOCKS_IO_CREATE_EXT           (EXT4_GET_BLOCKS_PRE_IO|\
 511                                          EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
 512         /* Convert extent to initialized after IO complete */
 513 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT          (EXT4_GET_BLOCKS_CONVERT|\
 514                                          EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
 515
 516 /*
 517  * Flags used by ext4_free_blocks
 518  */
 519 #define EXT4_FREE_BLOCKS_METADATA       0x0001
 520 #define EXT4_FREE_BLOCKS_FORGET         0x0002
 521 #define EXT4_FREE_BLOCKS_VALIDATED      0x0004
 522
 523 /*
 524  * ioctl commands
 525  */
 526 #define EXT4_IOC_GETFLAGS               FS_IOC_GETFLAGS
 527 #define EXT4_IOC_SETFLAGS               FS_IOC_SETFLAGS
 528 #define EXT4_IOC_GETVERSION             _IOR('f', 3, long)
 529 #define EXT4_IOC_SETVERSION             _IOW('f', 4, long)
 530 #define EXT4_IOC_GETVERSION_OLD         FS_IOC_GETVERSION
 531 #define EXT4_IOC_SETVERSION_OLD         FS_IOC_SETVERSION
 532 #ifdef CONFIG_JBD2_DEBUG
 533 #define EXT4_IOC_WAIT_FOR_READONLY      _IOR('f', 99, long)
 534 #endif
 535 #define EXT4_IOC_GETRSVSZ               _IOR('f', 5, long)
 536 #define EXT4_IOC_SETRSVSZ               _IOW('f', 6, long)
 537 #define EXT4_IOC_GROUP_EXTEND           _IOW('f', 7, unsigned long)
 538 #define EXT4_IOC_GROUP_ADD              _IOW('f', 8, struct ext4_new_group_input)
 539 #define EXT4_IOC_MIGRATE                _IO('f', 9)
 540  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
 541  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
 542 #define EXT4_IOC_ALLOC_DA_BLKS          _IO('f', 12)
 543 #define EXT4_IOC_MOVE_EXT               _IOWR('f', 15, struct move_extent)
 544
 545 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
 546 /*
 547  * ioctl commands in 32 bit emulation
 548  */
 549 #define EXT4_IOC32_GETFLAGS             FS_IOC32_GETFLAGS
 550 #define EXT4_IOC32_SETFLAGS             FS_IOC32_SETFLAGS
 551 #define EXT4_IOC32_GETVERSION           _IOR('f', 3, int)
 552 #define EXT4_IOC32_SETVERSION           _IOW('f', 4, int)
 553 #define EXT4_IOC32_GETRSVSZ             _IOR('f', 5, int)
 554 #define EXT4_IOC32_SETRSVSZ             _IOW('f', 6, int)
 555 #define EXT4_IOC32_GROUP_EXTEND         _IOW('f', 7, unsigned int)
 556 #define EXT4_IOC32_GROUP_ADD            _IOW('f', 8, struct compat_ext4_new_group_input)
 557 #ifdef CONFIG_JBD2_DEBUG
 558 #define EXT4_IOC32_WAIT_FOR_READONLY    _IOR('f', 99, int)
 559 #endif
 560 #define EXT4_IOC32_GETVERSION_OLD       FS_IOC32_GETVERSION
 561 #define EXT4_IOC32_SETVERSION_OLD       FS_IOC32_SETVERSION
 562 #endif
 563
 564 /* Max physical block we can addres w/o extents */
 565 #define EXT4_MAX_BLOCK_FILE_PHYS        0xFFFFFFFF
 566
 567 /*
 568  * Structure of an inode on the disk
 569  */
 570 struct ext4_inode {
 571         __le16  i_mode;         /* File mode */
 572         __le16  i_uid;          /* Low 16 bits of Owner Uid */
 573         __le32  i_size_lo;      /* Size in bytes */
 574         __le32  i_atime;        /* Access time */
 575         __le32  i_ctime;        /* Inode Change time */
 576         __le32  i_mtime;        /* Modification time */
 577         __le32  i_dtime;        /* Deletion Time */
 578         __le16  i_gid;          /* Low 16 bits of Group Id */
 579         __le16  i_links_count;  /* Links count */
 580         __le32  i_blocks_lo;    /* Blocks count */
 581         __le32  i_flags;        /* File flags */
 582         union {
 583                 struct {
 584                         __le32  l_i_version;
 585                 } linux1;
 586                 struct {
 587                         __u32  h_i_translator;
 588                 } hurd1;
 589                 struct {
 590                         __u32  m_i_reserved1;
 591                 } masix1;
 592         } osd1;                         /* OS dependent 1 */
 593         __le32  i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
 594         __le32  i_generation;   /* File version (for NFS) */
 595         __le32  i_file_acl_lo;  /* File ACL */
 596         __le32  i_size_high;
 597         __le32  i_obso_faddr;   /* Obsoleted fragment address */
 598         union {
 599                 struct {
 600                         __le16  l_i_blocks_high; /* were l_i_reserved1 */
 601                         __le16  l_i_file_acl_high;
 602                         __le16  l_i_uid_high;   /* these 2 fields */
 603                         __le16  l_i_gid_high;   /* were reserved2[0] */
 604                         __u32   l_i_reserved2;
 605                 } linux2;
 606                 struct {
 607                         __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
 608                         __u16   h_i_mode_high;
 609                         __u16   h_i_uid_high;
 610                         __u16   h_i_gid_high;
 611                         __u32   h_i_author;
 612                 } hurd2;
 613                 struct {
 614                         __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
 615                         __le16  m_i_file_acl_high;
 616                         __u32   m_i_reserved2[2];
 617                 } masix2;
 618         } osd2;                         /* OS dependent 2 */
 619         __le16  i_extra_isize;
 620         __le16  i_pad1;
 621         __le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
 622         __le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
 623         __le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
 624         __le32  i_crtime;       /* File Creation time */
 625         __le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
 626         __le32  i_version_hi;   /* high 32 bits for 64-bit version */
 627 };
 628
 629 struct move_extent {
 630         __u32 reserved;         /* should be zero */
 631         __u32 donor_fd;         /* donor file descriptor */
 632         __u64 orig_start;       /* logical start offset in block for orig */
 633         __u64 donor_start;      /* logical start offset in block for donor */
 634         __u64 len;              /* block length to be moved */
 635         __u64 moved_len;        /* moved block length */
 636 };
 637
 638 #define EXT4_EPOCH_BITS 2
 639 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
 640 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
 641
 642 /*
 643  * Extended fields will fit into an inode if the filesystem was formatted
 644  * with large inodes (-I 256 or larger) and there are not currently any EAs
 645  * consuming all of the available space. For new inodes we always reserve
 646  * enough space for the kernel's known extended fields, but for inodes
 647  * created with an old kernel this might not have been the case. None of
 648  * the extended inode fields is critical for correct filesystem operation.
 649  * This macro checks if a certain field fits in the inode. Note that
 650  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
 651  */
 652 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)   \
 653         ((offsetof(typeof(*ext4_inode), field) +        \
 654           sizeof((ext4_inode)->field))                  \
 655         <= (EXT4_GOOD_OLD_INODE_SIZE +                  \
 656             (einode)->i_extra_isize))                   \
 657
 658 static inline __le32 ext4_encode_extra_time(struct timespec *time)
 659 {
 660        return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
 661                            (time->tv_sec >> 32) & EXT4_EPOCH_MASK : 0) |
 662                           ((time->tv_nsec << EXT4_EPOCH_BITS) & EXT4_NSEC_MASK));
 663 }
 664
 665 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
 666 {
 667        if (sizeof(time->tv_sec) > 4)
 668                time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
 669                                << 32;
 670        time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
 671 }
 672
 673 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)                          \
 674 do {                                                                           \
 675         (raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);               \
 676         if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
 677                 (raw_inode)->xtime ## _extra =                                 \
 678                                 ext4_encode_extra_time(&(inode)->xtime);       \
 679 } while (0)
 680
 681 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)                        \
 682 do {                                                                           \
 683         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))                      \
 684                 (raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
 685         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))            \
 686                 (raw_inode)->xtime ## _extra =                                 \
 687                                 ext4_encode_extra_time(&(einode)->xtime);      \
 688 } while (0)
 689
 690 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)                          \
 691 do {                                                                           \
 692         (inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
 693         if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
 694                 ext4_decode_extra_time(&(inode)->xtime,                        \
 695                                        raw_inode->xtime ## _extra);            \
 696         else                                                                   \
 697                 (inode)->xtime.tv_nsec = 0;                                    \
 698 } while (0)
 699
 700 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)                        \
 701 do {                                                                           \
 702         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))                      \
 703                 (einode)->xtime.tv_sec =                                       \
 704                         (signed)le32_to_cpu((raw_inode)->xtime);               \
 705         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))            \
 706                 ext4_decode_extra_time(&(einode)->xtime,                       \
 707                                        raw_inode->xtime ## _extra);            \
 708         else                                                                   \
 709                 (einode)->xtime.tv_nsec = 0;                                   \
 710 } while (0)
 711
 712 #define i_disk_version osd1.linux1.l_i_version
 713
 714 #if defined(__KERNEL__) || defined(__linux__)
 715 #define i_reserved1     osd1.linux1.l_i_reserved1
 716 #define i_file_acl_high osd2.linux2.l_i_file_acl_high
 717 #define i_blocks_high   osd2.linux2.l_i_blocks_high
 718 #define i_uid_low       i_uid
 719 #define i_gid_low       i_gid
 720 #define i_uid_high      osd2.linux2.l_i_uid_high
 721 #define i_gid_high      osd2.linux2.l_i_gid_high
 722 #define i_reserved2     osd2.linux2.l_i_reserved2
 723
 724 #elif defined(__GNU__)
 725
 726 #define i_translator    osd1.hurd1.h_i_translator
 727 #define i_uid_high      osd2.hurd2.h_i_uid_high
 728 #define i_gid_high      osd2.hurd2.h_i_gid_high
 729 #define i_author        osd2.hurd2.h_i_author
 730
 731 #elif defined(__masix__)
 732
 733 #define i_reserved1     osd1.masix1.m_i_reserved1
 734 #define i_file_acl_high osd2.masix2.m_i_file_acl_high
 735 #define i_reserved2     osd2.masix2.m_i_reserved2
 736
 737 #endif /* defined(__KERNEL__) || defined(__linux__) */
 738
 739 /*
 740  * storage for cached extent
 741  */
 742 struct ext4_ext_cache {
 743         ext4_fsblk_t    ec_start;
 744         ext4_lblk_t     ec_block;
 745         __u32           ec_len; /* must be 32bit to return holes */
 746         __u32           ec_type;
 747 };
 748
 749 /*
 750  * fourth extended file system inode data in memory
 751  */
 752 struct ext4_inode_info {
 753         __le32  i_data[15];     /* unconverted */
 754         __u32   i_dtime;
 755         ext4_fsblk_t    i_file_acl;
 756
 757         /*
 758          * i_block_group is the number of the block group which contains
 759          * this file's inode.  Constant across the lifetime of the inode,
 760          * it is ued for making block allocation decisions - we try to
 761          * place a file's data blocks near its inode block, and new inodes
 762          * near to their parent directory's inode.
 763          */
 764         ext4_group_t    i_block_group;
 765         unsigned long   i_state_flags;          /* Dynamic state flags */
 766         unsigned long   i_flags;
 767
 768         ext4_lblk_t             i_dir_start_lookup;
 769 #ifdef CONFIG_EXT4_FS_XATTR
 770         /*
 771          * Extended attributes can be read independently of the main file
 772          * data. Taking i_mutex even when reading would cause contention
 773          * between readers of EAs and writers of regular file data, so
 774          * instead we synchronize on xattr_sem when reading or changing
 775          * EAs.
 776          */
 777         struct rw_semaphore xattr_sem;
 778 #endif
 779
 780         struct list_head i_orphan;      /* unlinked but open inodes */
 781
 782         /*
 783          * i_disksize keeps track of what the inode size is ON DISK, not
 784          * in memory.  During truncate, i_size is set to the new size by
 785          * the VFS prior to calling ext4_truncate(), but the filesystem won't
 786          * set i_disksize to 0 until the truncate is actually under way.
 787          *
 788          * The intent is that i_disksize always represents the blocks which
 789          * are used by this file.  This allows recovery to restart truncate
 790          * on orphans if we crash during truncate.  We actually write i_disksize
 791          * into the on-disk inode when writing inodes out, instead of i_size.
 792          *
 793          * The only time when i_disksize and i_size may be different is when
 794          * a truncate is in progress.  The only things which change i_disksize
 795          * are ext4_get_block (growth) and ext4_truncate (shrinkth).
 796          */
 797         loff_t  i_disksize;
 798
 799         /*
 800          * i_data_sem is for serialising ext4_truncate() against
 801          * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
 802          * data tree are chopped off during truncate. We can't do that in
 803          * ext4 because whenever we perform intermediate commits during
 804          * truncate, the inode and all the metadata blocks *must* be in a
 805          * consistent state which allows truncation of the orphans to restart
 806          * during recovery.  Hence we must fix the get_block-vs-truncate race
 807          * by other means, so we have i_data_sem.
 808          */
 809         struct rw_semaphore i_data_sem;
 810         struct inode vfs_inode;
 811         struct jbd2_inode jinode;
 812
 813         struct ext4_ext_cache i_cached_extent;
 814         /*
 815          * File creation time. Its function is same as that of
 816          * struct timespec i_{a,c,m}time in the generic inode.
 817          */
 818         struct timespec i_crtime;
 819
 820         /* mballoc */
 821         struct list_head i_prealloc_list;
 822         spinlock_t i_prealloc_lock;
 823
 824         /* ialloc */
 825         ext4_group_t    i_last_alloc_group;
 826
 827         /* allocation reservation info for delalloc */
 828         unsigned int i_reserved_data_blocks;
 829         unsigned int i_reserved_meta_blocks;
 830         unsigned int i_allocated_meta_blocks;
 831         unsigned short i_delalloc_reserved_flag;
 832         sector_t i_da_metadata_calc_last_lblock;
 833         int i_da_metadata_calc_len;
 834
 835         /* on-disk additional length */
 836         __u16 i_extra_isize;
 837
 838         spinlock_t i_block_reservation_lock;
 839 #ifdef CONFIG_QUOTA
 840         /* quota space reservation, managed internally by quota code */
 841         qsize_t i_reserved_quota;
 842 #endif
 843
 844         /* completed IOs that might need unwritten extents handling */
 845         struct list_head i_completed_io_list;
 846         spinlock_t i_completed_io_lock;
 847         /* current io_end structure for async DIO write*/
 848         ext4_io_end_t *cur_aio_dio;
 849         atomic_t i_ioend_count; /* Number of outstanding io_end structs */
 850
 851         /*
 852          * Transactions that contain inode's metadata needed to complete
 853          * fsync and fdatasync, respectively.
 854          */
 855         tid_t i_sync_tid;
 856         tid_t i_datasync_tid;
 857 };
 858
 859 /*
 860  * File system states
 861  */
 862 #define EXT4_VALID_FS                   0x0001  /* Unmounted cleanly */
 863 #define EXT4_ERROR_FS                   0x0002  /* Errors detected */
 864 #define EXT4_ORPHAN_FS                  0x0004  /* Orphans being recovered */
 865
 866 /*
 867  * Misc. filesystem flags
 868  */
 869 #define EXT2_FLAGS_SIGNED_HASH          0x0001  /* Signed dirhash in use */
 870 #define EXT2_FLAGS_UNSIGNED_HASH        0x0002  /* Unsigned dirhash in use */
 871 #define EXT2_FLAGS_TEST_FILESYS         0x0004  /* to test development code */
 872
 873 /*
 874  * Mount flags
 875  */
 876 #define EXT4_MOUNT_OLDALLOC             0x00002  /* Don't use the new Orlov allocator */
 877 #define EXT4_MOUNT_GRPID                0x00004 /* Create files with directory's group */
 878 #define EXT4_MOUNT_DEBUG                0x00008 /* Some debugging messages */
 879 #define EXT4_MOUNT_ERRORS_CONT          0x00010 /* Continue on errors */
 880 #define EXT4_MOUNT_ERRORS_RO            0x00020 /* Remount fs ro on errors */
 881 #define EXT4_MOUNT_ERRORS_PANIC         0x00040 /* Panic on errors */
 882 #define EXT4_MOUNT_MINIX_DF             0x00080 /* Mimics the Minix statfs */
 883 #define EXT4_MOUNT_NOLOAD               0x00100 /* Don't use existing journal*/
 884 #define EXT4_MOUNT_DATA_FLAGS           0x00C00 /* Mode for data writes: */
 885 #define EXT4_MOUNT_JOURNAL_DATA         0x00400 /* Write data to journal */
 886 #define EXT4_MOUNT_ORDERED_DATA         0x00800 /* Flush data before commit */
 887 #define EXT4_MOUNT_WRITEBACK_DATA       0x00C00 /* No data ordering */
 888 #define EXT4_MOUNT_UPDATE_JOURNAL       0x01000 /* Update the journal format */
 889 #define EXT4_MOUNT_NO_UID32             0x02000  /* Disable 32-bit UIDs */
 890 #define EXT4_MOUNT_XATTR_USER           0x04000 /* Extended user attributes */
 891 #define EXT4_MOUNT_POSIX_ACL            0x08000 /* POSIX Access Control Lists */
 892 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC     0x10000 /* No auto delalloc mapping */
 893 #define EXT4_MOUNT_BARRIER              0x20000 /* Use block barriers */
 894 #define EXT4_MOUNT_QUOTA                0x80000 /* Some quota option set */
 895 #define EXT4_MOUNT_USRQUOTA             0x100000 /* "old" user quota */
 896 #define EXT4_MOUNT_GRPQUOTA             0x200000 /* "old" group quota */
 897 #define EXT4_MOUNT_DIOREAD_NOLOCK       0x400000 /* Enable support for dio read nolocking */
 898 #define EXT4_MOUNT_JOURNAL_CHECKSUM     0x800000 /* Journal checksums */
 899 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT 0x1000000 /* Journal Async Commit */
 900 #define EXT4_MOUNT_I_VERSION            0x2000000 /* i_version support */
 901 #define EXT4_MOUNT_MBLK_IO_SUBMIT       0x4000000 /* multi-block io submits */
 902 #define EXT4_MOUNT_DELALLOC             0x8000000 /* Delalloc support */
 903 #define EXT4_MOUNT_DATA_ERR_ABORT       0x10000000 /* Abort on file data write */
 904 #define EXT4_MOUNT_BLOCK_VALIDITY       0x20000000 /* Block validity checking */
 905 #define EXT4_MOUNT_DISCARD              0x40000000 /* Issue DISCARD requests */
 906 #define EXT4_MOUNT_INIT_INODE_TABLE     0x80000000 /* Initialize uninitialized itables */
 907
 908 #define clear_opt(sb, opt)              EXT4_SB(sb)->s_mount_opt &= \
 909                                                 ~EXT4_MOUNT_##opt
 910 #define set_opt(sb, opt)                EXT4_SB(sb)->s_mount_opt |= \
 911                                                 EXT4_MOUNT_##opt
 912 #define test_opt(sb, opt)               (EXT4_SB(sb)->s_mount_opt & \
 913                                          EXT4_MOUNT_##opt)
 914
 915 #define clear_opt2(sb, opt)             EXT4_SB(sb)->s_mount_opt2 &= \
 916                                                 ~EXT4_MOUNT2_##opt
 917 #define set_opt2(sb, opt)               EXT4_SB(sb)->s_mount_opt2 |= \
 918                                                 EXT4_MOUNT2_##opt
 919 #define test_opt2(sb, opt)              (EXT4_SB(sb)->s_mount_opt2 & \
 920                                          EXT4_MOUNT2_##opt)
 921
 922 #define ext4_set_bit                    ext2_set_bit
 923 #define ext4_set_bit_atomic             ext2_set_bit_atomic
 924 #define ext4_clear_bit                  ext2_clear_bit
 925 #define ext4_clear_bit_atomic           ext2_clear_bit_atomic
 926 #define ext4_test_bit                   ext2_test_bit
 927 #define ext4_find_first_zero_bit        ext2_find_first_zero_bit
 928 #define ext4_find_next_zero_bit         ext2_find_next_zero_bit
 929 #define ext4_find_next_bit              ext2_find_next_bit
 930
 931 /*
 932  * Maximal mount counts between two filesystem checks
 933  */
 934 #define EXT4_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
 935 #define EXT4_DFL_CHECKINTERVAL          0       /* Don't use interval check */
 936
 937 /*
 938  * Behaviour when detecting errors
 939  */
 940 #define EXT4_ERRORS_CONTINUE            1       /* Continue execution */
 941 #define EXT4_ERRORS_RO                  2       /* Remount fs read-only */
 942 #define EXT4_ERRORS_PANIC               3       /* Panic */
 943 #define EXT4_ERRORS_DEFAULT             EXT4_ERRORS_CONTINUE
 944
 945 /*
 946  * Structure of the super block
 947  */
 948 struct ext4_super_block {
 949 /*00*/  __le32  s_inodes_count;         /* Inodes count */
 950         __le32  s_blocks_count_lo;      /* Blocks count */
 951         __le32  s_r_blocks_count_lo;    /* Reserved blocks count */
 952         __le32  s_free_blocks_count_lo; /* Free blocks count */
 953 /*10*/  __le32  s_free_inodes_count;    /* Free inodes count */
 954         __le32  s_first_data_block;     /* First Data Block */
 955         __le32  s_log_block_size;       /* Block size */
 956         __le32  s_obso_log_frag_size;   /* Obsoleted fragment size */
 957 /*20*/  __le32  s_blocks_per_group;     /* # Blocks per group */
 958         __le32  s_obso_frags_per_group; /* Obsoleted fragments per group */
 959         __le32  s_inodes_per_group;     /* # Inodes per group */
 960         __le32  s_mtime;                /* Mount time */
 961 /*30*/  __le32  s_wtime;                /* Write time */
 962         __le16  s_mnt_count;            /* Mount count */
 963         __le16  s_max_mnt_count;        /* Maximal mount count */
 964         __le16  s_magic;                /* Magic signature */
 965         __le16  s_state;                /* File system state */
 966         __le16  s_errors;               /* Behaviour when detecting errors */
 967         __le16  s_minor_rev_level;      /* minor revision level */
 968 /*40*/  __le32  s_lastcheck;            /* time of last check */
 969         __le32  s_checkinterval;        /* max. time between checks */
 970         __le32  s_creator_os;           /* OS */
 971         __le32  s_rev_level;            /* Revision level */
 972 /*50*/  __le16  s_def_resuid;           /* Default uid for reserved blocks */
 973         __le16  s_def_resgid;           /* Default gid for reserved blocks */
 974         /*
 975          * These fields are for EXT4_DYNAMIC_REV superblocks only.
 976          *
 977          * Note: the difference between the compatible feature set and
 978          * the incompatible feature set is that if there is a bit set
 979          * in the incompatible feature set that the kernel doesn't
 980          * know about, it should refuse to mount the filesystem.
 981          *
 982          * e2fsck's requirements are more strict; if it doesn't know
 983          * about a feature in either the compatible or incompatible
 984          * feature set, it must abort and not try to meddle with
 985          * things it doesn't understand...
 986          */
 987         __le32  s_first_ino;            /* First non-reserved inode */
 988         __le16  s_inode_size;           /* size of inode structure */
 989         __le16  s_block_group_nr;       /* block group # of this superblock */
 990         __le32  s_feature_compat;       /* compatible feature set */
 991 /*60*/  __le32  s_feature_incompat;     /* incompatible feature set */
 992         __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
 993 /*68*/  __u8    s_uuid[16];             /* 128-bit uuid for volume */
 994 /*78*/  char    s_volume_name[16];      /* volume name */
 995 /*88*/  char    s_last_mounted[64];     /* directory where last mounted */
 996 /*C8*/  __le32  s_algorithm_usage_bitmap; /* For compression */
 997         /*
 998          * Performance hints.  Directory preallocation should only
 999          * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
1000          */
1001         __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
1002         __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
1003         __le16  s_reserved_gdt_blocks;  /* Per group desc for online growth */
1004         /*
1005          * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
1006          */
1007 /*D0*/  __u8    s_journal_uuid[16];     /* uuid of journal superblock */
1008 /*E0*/  __le32  s_journal_inum;         /* inode number of journal file */
1009         __le32  s_journal_dev;          /* device number of journal file */
1010         __le32  s_last_orphan;          /* start of list of inodes to delete */
1011         __le32  s_hash_seed[4];         /* HTREE hash seed */
1012         __u8    s_def_hash_version;     /* Default hash version to use */
1013         __u8    s_jnl_backup_type;
1014         __le16  s_desc_size;            /* size of group descriptor */
1015 /*100*/ __le32  s_default_mount_opts;
1016         __le32  s_first_meta_bg;        /* First metablock block group */
1017         __le32  s_mkfs_time;            /* When the filesystem was created */
1018         __le32  s_jnl_blocks[17];       /* Backup of the journal inode */
1019         /* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
1020 /*150*/ __le32  s_blocks_count_hi;      /* Blocks count */
1021         __le32  s_r_blocks_count_hi;    /* Reserved blocks count */
1022         __le32  s_free_blocks_count_hi; /* Free blocks count */
1023         __le16  s_min_extra_isize;      /* All inodes have at least # bytes */
1024         __le16  s_want_extra_isize;     /* New inodes should reserve # bytes */
1025         __le32  s_flags;                /* Miscellaneous flags */
1026         __le16  s_raid_stride;          /* RAID stride */
1027         __le16  s_mmp_interval;         /* # seconds to wait in MMP checking */
1028         __le64  s_mmp_block;            /* Block for multi-mount protection */
1029         __le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1030         __u8    s_log_groups_per_flex;  /* FLEX_BG group size */
1031         __u8    s_reserved_char_pad;
1032         __le16  s_reserved_pad;
1033         __le64  s_kbytes_written;       /* nr of lifetime kilobytes written */
1034         __le32  s_snapshot_inum;        /* Inode number of active snapshot */
1035         __le32  s_snapshot_id;          /* sequential ID of active snapshot */
1036         __le64  s_snapshot_r_blocks_count; /* reserved blocks for active
1037                                               snapshot's future use */
1038         __le32  s_snapshot_list;        /* inode number of the head of the
1039                                            on-disk snapshot list */
1040 #define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
1041         __le32  s_error_count;          /* number of fs errors */
1042         __le32  s_first_error_time;     /* first time an error happened */
1043         __le32  s_first_error_ino;      /* inode involved in first error */
1044         __le64  s_first_error_block;    /* block involved of first error */
1045         __u8    s_first_error_func[32]; /* function where the error happened */
1046         __le32  s_first_error_line;     /* line number where error happened */
1047         __le32  s_last_error_time;      /* most recent time of an error */
1048         __le32  s_last_error_ino;       /* inode involved in last error */
1049         __le32  s_last_error_line;      /* line number where error happened */
1050         __le64  s_last_error_block;     /* block involved of last error */
1051         __u8    s_last_error_func[32];  /* function where the error happened */
1052 #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
1053         __u8    s_mount_opts[64];
1054         __le32  s_reserved[112];        /* Padding to the end of the block */
1055 };
1056
1057 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1058
1059 #ifdef __KERNEL__
1060
1061 /*
1062  * run-time mount flags
1063  */
1064 #define EXT4_MF_MNTDIR_SAMPLED  0x0001
1065 #define EXT4_MF_FS_ABORTED      0x0002  /* Fatal error detected */
1066
1067 /*
1068  * fourth extended-fs super-block data in memory
1069  */
1070 struct ext4_sb_info {
1071         unsigned long s_desc_size;      /* Size of a group descriptor in bytes */
1072         unsigned long s_inodes_per_block;/* Number of inodes per block */
1073         unsigned long s_blocks_per_group;/* Number of blocks in a group */
1074         unsigned long s_inodes_per_group;/* Number of inodes in a group */
1075         unsigned long s_itb_per_group;  /* Number of inode table blocks per group */
1076         unsigned long s_gdb_count;      /* Number of group descriptor blocks */
1077         unsigned long s_desc_per_block; /* Number of group descriptors per block */
1078         ext4_group_t s_groups_count;    /* Number of groups in the fs */
1079         ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1080         unsigned long s_overhead_last;  /* Last calculated overhead */
1081         unsigned long s_blocks_last;    /* Last seen block count */
1082         loff_t s_bitmap_maxbytes;       /* max bytes for bitmap files */
1083         struct buffer_head * s_sbh;     /* Buffer containing the super block */
1084         struct ext4_super_block *s_es;  /* Pointer to the super block in the buffer */
1085         struct buffer_head **s_group_desc;
1086         unsigned int s_mount_opt;
1087         unsigned int s_mount_opt2;
1088         unsigned int s_mount_flags;
1089         ext4_fsblk_t s_sb_block;
1090         uid_t s_resuid;
1091         gid_t s_resgid;
1092         unsigned short s_mount_state;
1093         unsigned short s_pad;
1094         int s_addr_per_block_bits;
1095         int s_desc_per_block_bits;
1096         int s_inode_size;
1097         int s_first_ino;
1098         unsigned int s_inode_readahead_blks;
1099         unsigned int s_inode_goal;
1100         spinlock_t s_next_gen_lock;
1101         u32 s_next_generation;
1102         u32 s_hash_seed[4];
1103         int s_def_hash_version;
1104         int s_hash_unsigned;    /* 3 if hash should be signed, 0 if not */
1105         struct percpu_counter s_freeblocks_counter;
1106         struct percpu_counter s_freeinodes_counter;
1107         struct percpu_counter s_dirs_counter;
1108         struct percpu_counter s_dirtyblocks_counter;
1109         struct blockgroup_lock *s_blockgroup_lock;
1110         struct proc_dir_entry *s_proc;
1111         struct kobject s_kobj;
1112         struct completion s_kobj_unregister;
1113
1114         /* Journaling */
1115         struct journal_s *s_journal;
1116         struct list_head s_orphan;
1117         struct mutex s_orphan_lock;
1118         struct mutex s_resize_lock;
1119         unsigned long s_commit_interval;
1120         u32 s_max_batch_time;
1121         u32 s_min_batch_time;
1122         struct block_device *journal_bdev;
1123 #ifdef CONFIG_JBD2_DEBUG
1124         struct timer_list turn_ro_timer;        /* For turning read-only (crash simulation) */
1125         wait_queue_head_t ro_wait_queue;        /* For people waiting for the fs to go read-only */
1126 #endif
1127 #ifdef CONFIG_QUOTA
1128         char *s_qf_names[MAXQUOTAS];            /* Names of quota files with journalled quota */
1129         int s_jquota_fmt;                       /* Format of quota to use */
1130 #endif
1131         unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1132         struct rb_root system_blks;
1133
1134 #ifdef EXTENTS_STATS
1135         /* ext4 extents stats */
1136         unsigned long s_ext_min;
1137         unsigned long s_ext_max;
1138         unsigned long s_depth_max;
1139         spinlock_t s_ext_stats_lock;
1140         unsigned long s_ext_blocks;
1141         unsigned long s_ext_extents;
1142 #endif
1143
1144         /* for buddy allocator */
1145         struct ext4_group_info ***s_group_info;
1146         struct inode *s_buddy_cache;
1147         spinlock_t s_md_lock;
1148         unsigned short *s_mb_offsets;
1149         unsigned int *s_mb_maxs;
1150
1151         /* tunables */
1152         unsigned long s_stripe;
1153         unsigned int s_mb_stream_request;
1154         unsigned int s_mb_max_to_scan;
1155         unsigned int s_mb_min_to_scan;
1156         unsigned int s_mb_stats;
1157         unsigned int s_mb_order2_reqs;
1158         unsigned int s_mb_group_prealloc;
1159         unsigned int s_max_writeback_mb_bump;
1160         /* where last allocation was done - for stream allocation */
1161         unsigned long s_mb_last_group;
1162         unsigned long s_mb_last_start;
1163
1164         /* stats for buddy allocator */
1165         atomic_t s_bal_reqs;    /* number of reqs with len > 1 */
1166         atomic_t s_bal_success; /* we found long enough chunks */
1167         atomic_t s_bal_allocated;       /* in blocks */
1168         atomic_t s_bal_ex_scanned;      /* total extents scanned */
1169         atomic_t s_bal_goals;   /* goal hits */
1170         atomic_t s_bal_breaks;  /* too long searches */
1171         atomic_t s_bal_2orders; /* 2^order hits */
1172         spinlock_t s_bal_lock;
1173         unsigned long s_mb_buddies_generated;
1174         unsigned long long s_mb_generation_time;
1175         atomic_t s_mb_lost_chunks;
1176         atomic_t s_mb_preallocated;
1177         atomic_t s_mb_discarded;
1178         atomic_t s_lock_busy;
1179
1180         /* locality groups */
1181         struct ext4_locality_group __percpu *s_locality_groups;
1182
1183         /* for write statistics */
1184         unsigned long s_sectors_written_start;
1185         u64 s_kbytes_written;
1186
1187         unsigned int s_log_groups_per_flex;
1188         struct flex_groups *s_flex_groups;
1189
1190         /* workqueue for dio unwritten */
1191         struct workqueue_struct *dio_unwritten_wq;
1192
1193         /* timer for periodic error stats printing */
1194         struct timer_list s_err_report;
1195
1196         /* Lazy inode table initialization info */
1197         struct ext4_li_request *s_li_request;
1198         /* Wait multiplier for lazy initialization thread */
1199         unsigned int s_li_wait_mult;
1200 };
1201
1202 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1203 {
1204         return sb->s_fs_info;
1205 }
1206 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1207 {
1208         return container_of(inode, struct ext4_inode_info, vfs_inode);
1209 }
1210
1211 static inline struct timespec ext4_current_time(struct inode *inode)
1212 {
1213         return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1214                 current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1215 }
1216
1217 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1218 {
1219         return ino == EXT4_ROOT_INO ||
1220                 ino == EXT4_JOURNAL_INO ||
1221                 ino == EXT4_RESIZE_INO ||
1222                 (ino >= EXT4_FIRST_INO(sb) &&
1223                  ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1224 }
1225
1226 /*
1227  * Inode dynamic state flags
1228  */
1229 enum {
1230         EXT4_STATE_JDATA,               /* journaled data exists */
1231         EXT4_STATE_NEW,                 /* inode is newly created */
1232         EXT4_STATE_XATTR,               /* has in-inode xattrs */
1233         EXT4_STATE_NO_EXPAND,           /* No space for expansion */
1234         EXT4_STATE_DA_ALLOC_CLOSE,      /* Alloc DA blks on close */
1235         EXT4_STATE_EXT_MIGRATE,         /* Inode is migrating */
1236         EXT4_STATE_DIO_UNWRITTEN,       /* need convert on dio done*/
1237         EXT4_STATE_NEWENTRY,            /* File just added to dir */
1238 };
1239
1240 #define EXT4_INODE_BIT_FNS(name, field)                                 \
1241 static inline int ext4_test_inode_##name(struct inode *inode, int bit)  \
1242 {                                                                       \
1243         return test_bit(bit, &EXT4_I(inode)->i_##field);                \
1244 }                                                                       \
1245 static inline void ext4_set_inode_##name(struct inode *inode, int bit)  \
1246 {                                                                       \
1247         set_bit(bit, &EXT4_I(inode)->i_##field);                        \
1248 }                                                                       \
1249 static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1250 {                                                                       \
1251         clear_bit(bit, &EXT4_I(inode)->i_##field);                      \
1252 }
1253
1254 EXT4_INODE_BIT_FNS(flag, flags)
1255 EXT4_INODE_BIT_FNS(state, state_flags)
1256 #else
1257 /* Assume that user mode programs are passing in an ext4fs superblock, not
1258  * a kernel struct super_block.  This will allow us to call the feature-test
1259  * macros from user land. */
1260 #define EXT4_SB(sb)     (sb)
1261 #endif
1262
1263 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1264
1265 /*
1266  * Codes for operating systems
1267  */
1268 #define EXT4_OS_LINUX           0
1269 #define EXT4_OS_HURD            1
1270 #define EXT4_OS_MASIX           2
1271 #define EXT4_OS_FREEBSD         3
1272 #define EXT4_OS_LITES           4
1273
1274 /*
1275  * Revision levels
1276  */
1277 #define EXT4_GOOD_OLD_REV       0       /* The good old (original) format */
1278 #define EXT4_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
1279
1280 #define EXT4_CURRENT_REV        EXT4_GOOD_OLD_REV
1281 #define EXT4_MAX_SUPP_REV       EXT4_DYNAMIC_REV
1282
1283 #define EXT4_GOOD_OLD_INODE_SIZE 128
1284
1285 /*
1286  * Feature set definitions
1287  */
1288
1289 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)                        \
1290         ((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1291 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
1292         ((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1293 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)                      \
1294         ((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1295 #define EXT4_SET_COMPAT_FEATURE(sb,mask)                        \
1296         EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1297 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)                     \
1298         EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1299 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)                      \
1300         EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1301 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)                      \
1302         EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1303 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
1304         EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1305 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
1306         EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1307
1308 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC        0x0001
1309 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES       0x0002
1310 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL         0x0004
1311 #define EXT4_FEATURE_COMPAT_EXT_ATTR            0x0008
1312 #define EXT4_FEATURE_COMPAT_RESIZE_INODE        0x0010
1313 #define EXT4_FEATURE_COMPAT_DIR_INDEX           0x0020
1314
1315 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
1316 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
1317 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
1318 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1319 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM         0x0010
1320 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK        0x0020
1321 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE      0x0040
1322
1323 #define EXT4_FEATURE_INCOMPAT_COMPRESSION       0x0001
1324 #define EXT4_FEATURE_INCOMPAT_FILETYPE          0x0002
1325 #define EXT4_FEATURE_INCOMPAT_RECOVER           0x0004 /* Needs recovery */
1326 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008 /* Journal device */
1327 #define EXT4_FEATURE_INCOMPAT_META_BG           0x0010
1328 #define EXT4_FEATURE_INCOMPAT_EXTENTS           0x0040 /* extents support */
1329 #define EXT4_FEATURE_INCOMPAT_64BIT             0x0080
1330 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1331 #define EXT4_FEATURE_INCOMPAT_FLEX_BG           0x0200
1332 #define EXT4_FEATURE_INCOMPAT_EA_INODE          0x0400 /* EA in inode */
1333 #define EXT4_FEATURE_INCOMPAT_DIRDATA           0x1000 /* data in dirent */
1334
1335 #define EXT4_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
1336 #define EXT4_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1337                                          EXT4_FEATURE_INCOMPAT_RECOVER| \
1338                                          EXT4_FEATURE_INCOMPAT_META_BG| \
1339                                          EXT4_FEATURE_INCOMPAT_EXTENTS| \
1340                                          EXT4_FEATURE_INCOMPAT_64BIT| \
1341                                          EXT4_FEATURE_INCOMPAT_FLEX_BG)
1342 #define EXT4_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1343                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1344                                          EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1345                                          EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1346                                          EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1347                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1348                                          EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
1349
1350 /*
1351  * Default values for user and/or group using reserved blocks
1352  */
1353 #define EXT4_DEF_RESUID         0
1354 #define EXT4_DEF_RESGID         0
1355
1356 #define EXT4_DEF_INODE_READAHEAD_BLKS   32
1357
1358 /*
1359  * Default mount options
1360  */
1361 #define EXT4_DEFM_DEBUG         0x0001
1362 #define EXT4_DEFM_BSDGROUPS     0x0002
1363 #define EXT4_DEFM_XATTR_USER    0x0004
1364 #define EXT4_DEFM_ACL           0x0008
1365 #define EXT4_DEFM_UID16         0x0010
1366 #define EXT4_DEFM_JMODE         0x0060
1367 #define EXT4_DEFM_JMODE_DATA    0x0020
1368 #define EXT4_DEFM_JMODE_ORDERED 0x0040
1369 #define EXT4_DEFM_JMODE_WBACK   0x0060
1370 #define EXT4_DEFM_NOBARRIER     0x0100
1371 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
1372 #define EXT4_DEFM_DISCARD       0x0400
1373 #define EXT4_DEFM_NODELALLOC    0x0800
1374
1375 /*
1376  * Default journal batch times
1377  */
1378 #define EXT4_DEF_MIN_BATCH_TIME 0
1379 #define EXT4_DEF_MAX_BATCH_TIME 15000 /* 15ms */
1380
1381 /*
1382  * Minimum number of groups in a flexgroup before we separate out
1383  * directories into the first block group of a flexgroup
1384  */
1385 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME 4
1386
1387 /*
1388  * Structure of a directory entry
1389  */
1390 #define EXT4_NAME_LEN 255
1391
1392 struct ext4_dir_entry {
1393         __le32  inode;                  /* Inode number */
1394         __le16  rec_len;                /* Directory entry length */
1395         __le16  name_len;               /* Name length */
1396         char    name[EXT4_NAME_LEN];    /* File name */
1397 };
1398
1399 /*
1400  * The new version of the directory entry.  Since EXT4 structures are
1401  * stored in intel byte order, and the name_len field could never be
1402  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1403  * file_type field.
1404  */
1405 struct ext4_dir_entry_2 {
1406         __le32  inode;                  /* Inode number */
1407         __le16  rec_len;                /* Directory entry length */
1408         __u8    name_len;               /* Name length */
1409         __u8    file_type;
1410         char    name[EXT4_NAME_LEN];    /* File name */
1411 };
1412
1413 /*
1414  * Ext4 directory file types.  Only the low 3 bits are used.  The
1415  * other bits are reserved for now.
1416  */
1417 #define EXT4_FT_UNKNOWN         0
1418 #define EXT4_FT_REG_FILE        1
1419 #define EXT4_FT_DIR             2
1420 #define EXT4_FT_CHRDEV          3
1421 #define EXT4_FT_BLKDEV          4
1422 #define EXT4_FT_FIFO            5
1423 #define EXT4_FT_SOCK            6
1424 #define EXT4_FT_SYMLINK         7
1425
1426 #define EXT4_FT_MAX             8
1427
1428 /*
1429  * EXT4_DIR_PAD defines the directory entries boundaries
1430  *
1431  * NOTE: It must be a multiple of 4
1432  */
1433 #define EXT4_DIR_PAD                    4
1434 #define EXT4_DIR_ROUND                  (EXT4_DIR_PAD - 1)
1435 #define EXT4_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT4_DIR_ROUND) & \
1436                                          ~EXT4_DIR_ROUND)
1437 #define EXT4_MAX_REC_LEN                ((1<<16)-1)
1438
1439 /*
1440  * If we ever get support for fs block sizes > page_size, we'll need
1441  * to remove the #if statements in the next two functions...
1442  */
1443 static inline unsigned int
1444 ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
1445 {
1446         unsigned len = le16_to_cpu(dlen);
1447
1448 #if (PAGE_CACHE_SIZE >= 65536)
1449         if (len == EXT4_MAX_REC_LEN || len == 0)
1450                 return blocksize;
1451         return (len & 65532) | ((len & 3) << 16);
1452 #else
1453         return len;
1454 #endif
1455 }
1456
1457 static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
1458 {
1459         if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
1460                 BUG();
1461 #if (PAGE_CACHE_SIZE >= 65536)
1462         if (len < 65536)
1463                 return cpu_to_le16(len);
1464         if (len == blocksize) {
1465                 if (blocksize == 65536)
1466                         return cpu_to_le16(EXT4_MAX_REC_LEN);
1467                 else
1468                         return cpu_to_le16(0);
1469         }
1470         return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
1471 #else
1472         return cpu_to_le16(len);
1473 #endif
1474 }
1475
1476 /*
1477  * Hash Tree Directory indexing
1478  * (c) Daniel Phillips, 2001
1479  */
1480
1481 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1482                                       EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1483                     ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
1484 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1485 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1486
1487 /* Legal values for the dx_root hash_version field: */
1488
1489 #define DX_HASH_LEGACY          0
1490 #define DX_HASH_HALF_MD4        1
1491 #define DX_HASH_TEA             2
1492 #define DX_HASH_LEGACY_UNSIGNED 3
1493 #define DX_HASH_HALF_MD4_UNSIGNED       4
1494 #define DX_HASH_TEA_UNSIGNED            5
1495
1496 #ifdef __KERNEL__
1497
1498 /* hash info structure used by the directory hash */
1499 struct dx_hash_info
1500 {
1501         u32             hash;
1502         u32             minor_hash;
1503         int             hash_version;
1504         u32             *seed;
1505 };
1506
1507 #define EXT4_HTREE_EOF  0x7fffffff
1508
1509 /*
1510  * Control parameters used by ext4_htree_next_block
1511  */
1512 #define HASH_NB_ALWAYS          1
1513
1514
1515 /*
1516  * Describe an inode's exact location on disk and in memory
1517  */
1518 struct ext4_iloc
1519 {
1520         struct buffer_head *bh;
1521         unsigned long offset;
1522         ext4_group_t block_group;
1523 };
1524
1525 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1526 {
1527         return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1528 }
1529
1530 /*
1531  * This structure is stuffed into the struct file's private_data field
1532  * for directories.  It is where we put information so that we can do
1533  * readdir operations in hash tree order.
1534  */
1535 struct dir_private_info {
1536         struct rb_root  root;
1537         struct rb_node  *curr_node;
1538         struct fname    *extra_fname;
1539         loff_t          last_pos;
1540         __u32           curr_hash;
1541         __u32           curr_minor_hash;
1542         __u32           next_hash;
1543 };
1544
1545 /* calculate the first block number of the group */
1546 static inline ext4_fsblk_t
1547 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1548 {
1549         return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1550                 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1551 }
1552
1553 /*
1554  * Special error return code only used by dx_probe() and its callers.
1555  */
1556 #define ERR_BAD_DX_DIR  -75000
1557
1558 void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
1559                         ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp);
1560
1561 /*
1562  * Timeout and state flag for lazy initialization inode thread.
1563  */
1564 #define EXT4_DEF_LI_WAIT_MULT                   10
1565 #define EXT4_DEF_LI_MAX_START_DELAY             5
1566 #define EXT4_LAZYINIT_QUIT                      0x0001
1567 #define EXT4_LAZYINIT_RUNNING                   0x0002
1568
1569 /*
1570  * Lazy inode table initialization info
1571  */
1572 struct ext4_lazy_init {
1573         unsigned long           li_state;
1574
1575         wait_queue_head_t       li_wait_daemon;
1576         wait_queue_head_t       li_wait_task;
1577         struct timer_list       li_timer;
1578         struct task_struct      *li_task;
1579
1580         struct list_head        li_request_list;
1581         struct mutex            li_list_mtx;
1582 };
1583
1584 struct ext4_li_request {
1585         struct super_block      *lr_super;
1586         struct ext4_sb_info     *lr_sbi;
1587         ext4_group_t            lr_next_group;
1588         struct list_head        lr_request;
1589         unsigned long           lr_next_sched;
1590         unsigned long           lr_timeout;
1591 };
1592
1593 struct ext4_features {
1594         struct kobject f_kobj;
1595         struct completion f_kobj_unregister;
1596 };
1597
1598 /*
1599  * Function prototypes
1600  */
1601
1602 /*
1603  * Ok, these declarations are also in <linux/kernel.h> but none of the
1604  * ext4 source programs needs to include it so they are duplicated here.
1605  */
1606 # define NORET_TYPE     /**/
1607 # define ATTRIB_NORET   __attribute__((noreturn))
1608 # define NORET_AND      noreturn,
1609
1610 /* bitmap.c */
1611 extern unsigned int ext4_count_free(struct buffer_head *, unsigned);
1612
1613 /* balloc.c */
1614 extern unsigned int ext4_block_group(struct super_block *sb,
1615                         ext4_fsblk_t blocknr);
1616 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1617                         ext4_fsblk_t blocknr);
1618 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1619 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1620                         ext4_group_t group);
1621 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1622                         ext4_fsblk_t goal, unsigned long *count, int *errp);
1623 extern int ext4_claim_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
1624 extern void ext4_add_groupblocks(handle_t *handle, struct super_block *sb,
1625                                 ext4_fsblk_t block, unsigned long count);
1626 extern ext4_fsblk_t ext4_count_free_blocks(struct super_block *);
1627 extern void ext4_check_blocks_bitmap(struct super_block *);
1628 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1629                                                     ext4_group_t block_group,
1630                                                     struct buffer_head ** bh);
1631 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1632 struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1633                                       ext4_group_t block_group);
1634 extern unsigned ext4_init_block_bitmap(struct super_block *sb,
1635                                        struct buffer_head *bh,
1636                                        ext4_group_t group,
1637                                        struct ext4_group_desc *desc);
1638 #define ext4_free_blocks_after_init(sb, group, desc)                    \
1639                 ext4_init_block_bitmap(sb, NULL, group, desc)
1640
1641 /* dir.c */
1642 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
1643                                   struct file *,
1644                                   struct ext4_dir_entry_2 *,
1645                                   struct buffer_head *, unsigned int);
1646 #define ext4_check_dir_entry(dir, filp, de, bh, offset)                 \
1647         unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
1648                                         (de), (bh), (offset)))
1649 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1650                                     __u32 minor_hash,
1651                                     struct ext4_dir_entry_2 *dirent);
1652 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
1653
1654 /* fsync.c */
1655 extern int ext4_sync_file(struct file *, int);
1656
1657 /* hash.c */
1658 extern int ext4fs_dirhash(const char *name, int len, struct
1659                           dx_hash_info *hinfo);
1660
1661 /* ialloc.c */
1662 extern struct inode *ext4_new_inode(handle_t *, struct inode *, int,
1663                                     const struct qstr *qstr, __u32 goal);
1664 extern void ext4_free_inode(handle_t *, struct inode *);
1665 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
1666 extern unsigned long ext4_count_free_inodes(struct super_block *);
1667 extern unsigned long ext4_count_dirs(struct super_block *);
1668 extern void ext4_check_inodes_bitmap(struct super_block *);
1669 extern void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
1670 extern int ext4_init_inode_table(struct super_block *sb,
1671                                  ext4_group_t group, int barrier);
1672
1673 /* mballoc.c */
1674 extern long ext4_mb_stats;
1675 extern long ext4_mb_max_to_scan;
1676 extern int ext4_mb_init(struct super_block *, int);
1677 extern int ext4_mb_release(struct super_block *);
1678 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
1679                                 struct ext4_allocation_request *, int *);
1680 extern int ext4_mb_reserve_blocks(struct super_block *, int);
1681 extern void ext4_discard_preallocations(struct inode *);
1682 extern int __init ext4_init_mballoc(void);
1683 extern void ext4_exit_mballoc(void);
1684 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
1685                              struct buffer_head *bh, ext4_fsblk_t block,
1686                              unsigned long count, int flags);
1687 extern int ext4_mb_add_groupinfo(struct super_block *sb,
1688                 ext4_group_t i, struct ext4_group_desc *desc);
1689 extern int ext4_trim_fs(struct super_block *, struct fstrim_range *);
1690
1691 /* inode.c */
1692 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
1693                                                 ext4_lblk_t, int, int *);
1694 struct buffer_head *ext4_bread(handle_t *, struct inode *,
1695                                                 ext4_lblk_t, int, int *);
1696 int ext4_get_block(struct inode *inode, sector_t iblock,
1697                                 struct buffer_head *bh_result, int create);
1698
1699 extern struct inode *ext4_iget(struct super_block *, unsigned long);
1700 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
1701 extern int  ext4_setattr(struct dentry *, struct iattr *);
1702 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
1703                                 struct kstat *stat);
1704 extern void ext4_evict_inode(struct inode *);
1705 extern void ext4_clear_inode(struct inode *);
1706 extern int  ext4_sync_inode(handle_t *, struct inode *);
1707 extern void ext4_dirty_inode(struct inode *);
1708 extern int ext4_change_inode_journal_flag(struct inode *, int);
1709 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
1710 extern int ext4_can_truncate(struct inode *inode);
1711 extern void ext4_truncate(struct inode *);
1712 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
1713 extern void ext4_set_inode_flags(struct inode *);
1714 extern void ext4_get_inode_flags(struct ext4_inode_info *);
1715 extern int ext4_alloc_da_blocks(struct inode *inode);
1716 extern void ext4_set_aops(struct inode *inode);
1717 extern int ext4_writepage_trans_blocks(struct inode *);
1718 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
1719 extern int ext4_block_truncate_page(handle_t *handle,
1720                 struct address_space *mapping, loff_t from);
1721 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
1722 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
1723 extern void ext4_da_update_reserve_space(struct inode *inode,
1724                                         int used, int quota_claim);
1725 /* ioctl.c */
1726 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
1727 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
1728
1729 /* migrate.c */
1730 extern int ext4_ext_migrate(struct inode *);
1731
1732 /* namei.c */
1733 extern int ext4_orphan_add(handle_t *, struct inode *);
1734 extern int ext4_orphan_del(handle_t *, struct inode *);
1735 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1736                                 __u32 start_minor_hash, __u32 *next_hash);
1737
1738 /* resize.c */
1739 extern int ext4_group_add(struct super_block *sb,
1740                                 struct ext4_new_group_data *input);
1741 extern int ext4_group_extend(struct super_block *sb,
1742                                 struct ext4_super_block *es,
1743                                 ext4_fsblk_t n_blocks_count);
1744
1745 /* super.c */
1746 extern void __ext4_error(struct super_block *, const char *, unsigned int,
1747                          const char *, ...)
1748         __attribute__ ((format (printf, 4, 5)));
1749 #define ext4_error(sb, message...)      __ext4_error(sb, __func__,      \
1750                                                      __LINE__, ## message)
1751 extern void ext4_error_inode(struct inode *, const char *, unsigned int,
1752                              ext4_fsblk_t, const char *, ...)
1753         __attribute__ ((format (printf, 5, 6)));
1754 extern void ext4_error_file(struct file *, const char *, unsigned int,
1755                             ext4_fsblk_t, const char *, ...)
1756         __attribute__ ((format (printf, 5, 6)));
1757 extern void __ext4_std_error(struct super_block *, const char *,
1758                              unsigned int, int);
1759 extern void __ext4_abort(struct super_block *, const char *, unsigned int,
1760                        const char *, ...)
1761         __attribute__ ((format (printf, 4, 5)));
1762 #define ext4_abort(sb, message...)      __ext4_abort(sb, __func__, \
1763                                                        __LINE__, ## message)
1764 extern void __ext4_warning(struct super_block *, const char *, unsigned int,
1765                           const char *, ...)
1766         __attribute__ ((format (printf, 4, 5)));
1767 #define ext4_warning(sb, message...)    __ext4_warning(sb, __func__, \
1768                                                        __LINE__, ## message)
1769 extern void ext4_msg(struct super_block *, const char *, const char *, ...)
1770         __attribute__ ((format (printf, 3, 4)));
1771 extern void __ext4_grp_locked_error(const char *, unsigned int, \
1772                                     struct super_block *, ext4_group_t, \
1773                                     unsigned long, ext4_fsblk_t, \
1774                                     const char *, ...)
1775         __attribute__ ((format (printf, 7, 8)));
1776 #define ext4_grp_locked_error(sb, grp, message...) \
1777         __ext4_grp_locked_error(__func__, __LINE__, (sb), (grp), ## message)
1778 extern void ext4_update_dynamic_rev(struct super_block *sb);
1779 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
1780                                         __u32 compat);
1781 extern int ext4_update_rocompat_feature(handle_t *handle,
1782                                         struct super_block *sb, __u32 rocompat);
1783 extern int ext4_update_incompat_feature(handle_t *handle,
1784                                         struct super_block *sb, __u32 incompat);
1785 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
1786                                       struct ext4_group_desc *bg);
1787 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
1788                                       struct ext4_group_desc *bg);
1789 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
1790                                      struct ext4_group_desc *bg);
1791 extern __u32 ext4_free_blks_count(struct super_block *sb,
1792                                 struct ext4_group_desc *bg);
1793 extern __u32 ext4_free_inodes_count(struct super_block *sb,
1794                                  struct ext4_group_desc *bg);
1795 extern __u32 ext4_used_dirs_count(struct super_block *sb,
1796                                 struct ext4_group_desc *bg);
1797 extern __u32 ext4_itable_unused_count(struct super_block *sb,
1798                                    struct ext4_group_desc *bg);
1799 extern void ext4_block_bitmap_set(struct super_block *sb,
1800                                   struct ext4_group_desc *bg, ext4_fsblk_t blk);
1801 extern void ext4_inode_bitmap_set(struct super_block *sb,
1802                                   struct ext4_group_desc *bg, ext4_fsblk_t blk);
1803 extern void ext4_inode_table_set(struct super_block *sb,
1804                                  struct ext4_group_desc *bg, ext4_fsblk_t blk);
1805 extern void ext4_free_blks_set(struct super_block *sb,
1806                                struct ext4_group_desc *bg, __u32 count);
1807 extern void ext4_free_inodes_set(struct super_block *sb,
1808                                 struct ext4_group_desc *bg, __u32 count);
1809 extern void ext4_used_dirs_set(struct super_block *sb,
1810                                 struct ext4_group_desc *bg, __u32 count);
1811 extern void ext4_itable_unused_set(struct super_block *sb,
1812                                    struct ext4_group_desc *bg, __u32 count);
1813 extern __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 group,
1814                                    struct ext4_group_desc *gdp);
1815 extern int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 group,
1816                                        struct ext4_group_desc *gdp);
1817
1818 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
1819 {
1820         return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
1821                 le32_to_cpu(es->s_blocks_count_lo);
1822 }
1823
1824 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
1825 {
1826         return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
1827                 le32_to_cpu(es->s_r_blocks_count_lo);
1828 }
1829
1830 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
1831 {
1832         return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
1833                 le32_to_cpu(es->s_free_blocks_count_lo);
1834 }
1835
1836 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
1837                                          ext4_fsblk_t blk)
1838 {
1839         es->s_blocks_count_lo = cpu_to_le32((u32)blk);
1840         es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
1841 }
1842
1843 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
1844                                               ext4_fsblk_t blk)
1845 {
1846         es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
1847         es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
1848 }
1849
1850 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
1851                                            ext4_fsblk_t blk)
1852 {
1853         es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
1854         es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
1855 }
1856
1857 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
1858 {
1859         if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
1860                 return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
1861                         le32_to_cpu(raw_inode->i_size_lo);
1862         else
1863                 return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
1864 }
1865
1866 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
1867 {
1868         raw_inode->i_size_lo = cpu_to_le32(i_size);
1869         raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
1870 }
1871
1872 static inline
1873 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
1874                                             ext4_group_t group)
1875 {
1876          struct ext4_group_info ***grp_info;
1877          long indexv, indexh;
1878          grp_info = EXT4_SB(sb)->s_group_info;
1879          indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
1880          indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
1881          return grp_info[indexv][indexh];
1882 }
1883
1884 /*
1885  * Reading s_groups_count requires using smp_rmb() afterwards.  See
1886  * the locking protocol documented in the comments of ext4_group_add()
1887  * in resize.c
1888  */
1889 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
1890 {
1891         ext4_group_t    ngroups = EXT4_SB(sb)->s_groups_count;
1892
1893         smp_rmb();
1894         return ngroups;
1895 }
1896
1897 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
1898                                              ext4_group_t block_group)
1899 {
1900         return block_group >> sbi->s_log_groups_per_flex;
1901 }
1902
1903 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
1904 {
1905         return 1 << sbi->s_log_groups_per_flex;
1906 }
1907
1908 #define ext4_std_error(sb, errno)                               \
1909 do {                                                            \
1910         if ((errno))                                            \
1911                 __ext4_std_error((sb), __func__, __LINE__, (errno));    \
1912 } while (0)
1913
1914 #ifdef CONFIG_SMP
1915 /* Each CPU can accumulate percpu_counter_batch blocks in their local
1916  * counters. So we need to make sure we have free blocks more
1917  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
1918  */
1919 #define EXT4_FREEBLOCKS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
1920 #else
1921 #define EXT4_FREEBLOCKS_WATERMARK 0
1922 #endif
1923
1924 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
1925 {
1926         /*
1927          * XXX: replace with spinlock if seen contended -bzzz
1928          */
1929         down_write(&EXT4_I(inode)->i_data_sem);
1930         if (newsize > EXT4_I(inode)->i_disksize)
1931                 EXT4_I(inode)->i_disksize = newsize;
1932         up_write(&EXT4_I(inode)->i_data_sem);
1933         return ;
1934 }
1935
1936 struct ext4_group_info {
1937         unsigned long   bb_state;
1938         struct rb_root  bb_free_root;
1939         ext4_grpblk_t   bb_first_free;  /* first free block */
1940         ext4_grpblk_t   bb_free;        /* total free blocks */
1941         ext4_grpblk_t   bb_fragments;   /* nr of freespace fragments */
1942         ext4_grpblk_t   bb_largest_free_order;/* order of largest frag in BG */
1943         struct          list_head bb_prealloc_list;
1944 #ifdef DOUBLE_CHECK
1945         void            *bb_bitmap;
1946 #endif
1947         struct rw_semaphore alloc_sem;
1948         ext4_grpblk_t   bb_counters[];  /* Nr of free power-of-two-block
1949                                          * regions, index is order.
1950                                          * bb_counters[3] = 5 means
1951                                          * 5 free 8-block regions. */
1952 };
1953
1954 #define EXT4_GROUP_INFO_NEED_INIT_BIT   0
1955
1956 #define EXT4_MB_GRP_NEED_INIT(grp)      \
1957         (test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
1958
1959 #define EXT4_MAX_CONTENTION             8
1960 #define EXT4_CONTENTION_THRESHOLD       2
1961
1962 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
1963                                               ext4_group_t group)
1964 {
1965         return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
1966 }
1967
1968 /*
1969  * Returns true if the filesystem is busy enough that attempts to
1970  * access the block group locks has run into contention.
1971  */
1972 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
1973 {
1974         return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
1975 }
1976
1977 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
1978 {
1979         spinlock_t *lock = ext4_group_lock_ptr(sb, group);
1980         if (spin_trylock(lock))
1981                 /*
1982                  * We're able to grab the lock right away, so drop the
1983                  * lock contention counter.
1984                  */
1985                 atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
1986         else {
1987                 /*
1988                  * The lock is busy, so bump the contention counter,
1989                  * and then wait on the spin lock.
1990                  */
1991                 atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
1992                                   EXT4_MAX_CONTENTION);
1993                 spin_lock(lock);
1994         }
1995 }
1996
1997 static inline void ext4_unlock_group(struct super_block *sb,
1998                                         ext4_group_t group)
1999 {
2000         spin_unlock(ext4_group_lock_ptr(sb, group));
2001 }
2002
2003 static inline void ext4_mark_super_dirty(struct super_block *sb)
2004 {
2005         if (EXT4_SB(sb)->s_journal == NULL)
2006                 sb->s_dirt =1;
2007 }
2008
2009 /*
2010  * Inodes and files operations
2011  */
2012
2013 /* dir.c */
2014 extern const struct file_operations ext4_dir_operations;
2015
2016 /* file.c */
2017 extern const struct inode_operations ext4_file_inode_operations;
2018 extern const struct file_operations ext4_file_operations;
2019 extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
2020
2021 /* namei.c */
2022 extern const struct inode_operations ext4_dir_inode_operations;
2023 extern const struct inode_operations ext4_special_inode_operations;
2024 extern struct dentry *ext4_get_parent(struct dentry *child);
2025
2026 /* symlink.c */
2027 extern const struct inode_operations ext4_symlink_inode_operations;
2028 extern const struct inode_operations ext4_fast_symlink_inode_operations;
2029
2030 /* block_validity */
2031 extern void ext4_release_system_zone(struct super_block *sb);
2032 extern int ext4_setup_system_zone(struct super_block *sb);
2033 extern int __init ext4_init_system_zone(void);
2034 extern void ext4_exit_system_zone(void);
2035 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
2036                                  ext4_fsblk_t start_blk,
2037                                  unsigned int count);
2038
2039 /* extents.c */
2040 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
2041 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
2042 extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks,
2043                                        int chunk);
2044 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
2045                                struct ext4_map_blocks *map, int flags);
2046 extern void ext4_ext_truncate(struct inode *);
2047 extern void ext4_ext_init(struct super_block *);
2048 extern void ext4_ext_release(struct super_block *);
2049 extern long ext4_fallocate(struct inode *inode, int mode, loff_t offset,
2050                           loff_t len);
2051 extern int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
2052                           ssize_t len);
2053 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
2054                            struct ext4_map_blocks *map, int flags);
2055 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
2056                         __u64 start, __u64 len);
2057 /* move_extent.c */
2058 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
2059                              __u64 start_orig, __u64 start_donor,
2060                              __u64 len, __u64 *moved_len);
2061
2062 /* page-io.c */
2063 extern int __init ext4_init_pageio(void);
2064 extern void ext4_exit_pageio(void);
2065 extern void ext4_ioend_wait(struct inode *);
2066 extern void ext4_free_io_end(ext4_io_end_t *io);
2067 extern ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags);
2068 extern int ext4_end_io_nolock(ext4_io_end_t *io);
2069 extern void ext4_io_submit(struct ext4_io_submit *io);
2070 extern int ext4_bio_write_page(struct ext4_io_submit *io,
2071                                struct page *page,
2072                                int len,
2073                                struct writeback_control *wbc);
2074
2075 /* BH_Uninit flag: blocks are allocated but uninitialized on disk */
2076 enum ext4_state_bits {
2077         BH_Uninit       /* blocks are allocated but uninitialized on disk */
2078           = BH_JBDPrivateStart,
2079 };
2080
2081 BUFFER_FNS(Uninit, uninit)
2082 TAS_BUFFER_FNS(Uninit, uninit)
2083
2084 /*
2085  * Add new method to test wether block and inode bitmaps are properly
2086  * initialized. With uninit_bg reading the block from disk is not enough
2087  * to mark the bitmap uptodate. We need to also zero-out the bitmap
2088  */
2089 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
2090
2091 static inline int bitmap_uptodate(struct buffer_head *bh)
2092 {
2093         return (buffer_uptodate(bh) &&
2094                         test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
2095 }
2096 static inline void set_bitmap_uptodate(struct buffer_head *bh)
2097 {
2098         set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
2099 }
2100
2101 #define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
2102
2103 #endif  /* __KERNEL__ */
2104
2105 #endif  /* _EXT4_H */