Pileus Git - ~andy/linux/blob - fs/ext4/ext4.h

   1 /*
   2  *  ext4.h
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/include/linux/minix_fs.h
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  */
  15
  16 #ifndef _EXT4_H
  17 #define _EXT4_H
  18
  19 #include <linux/types.h>
  20 #include <linux/blkdev.h>
  21 #include <linux/magic.h>
  22 #include <linux/jbd2.h>
  23 #include <linux/quota.h>
  24 #include <linux/rwsem.h>
  25 #include <linux/rbtree.h>
  26 #include <linux/seqlock.h>
  27 #include <linux/mutex.h>
  28 #include <linux/timer.h>
  29 #include <linux/wait.h>
  30 #include <linux/blockgroup_lock.h>
  31 #include <linux/percpu_counter.h>
  32 #include <linux/ratelimit.h>
  33 #include <crypto/hash.h>
  34 #ifdef __KERNEL__
  35 #include <linux/compat.h>
  36 #endif
  37
  38 /*
  39  * The fourth extended filesystem constants/structures
  40  */
  41
  42 /*
  43  * Define EXT4FS_DEBUG to produce debug messages
  44  */
  45 #undef EXT4FS_DEBUG
  46
  47 /*
  48  * Debug code
  49  */
  50 #ifdef EXT4FS_DEBUG
  51 #define ext4_debug(f, a...)                                             \
  52         do {                                                            \
  53                 printk(KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:",        \
  54                         __FILE__, __LINE__, __func__);                  \
  55                 printk(KERN_DEBUG f, ## a);                             \
  56         } while (0)
  57 #else
  58 #define ext4_debug(fmt, ...)    no_printk(fmt, ##__VA_ARGS__)
  59 #endif
  60
  61 /*
  62  * Turn on EXT_DEBUG to get lots of info about extents operations.
  63  */
  64 #define EXT_DEBUG__
  65 #ifdef EXT_DEBUG
  66 #define ext_debug(fmt, ...)     printk(fmt, ##__VA_ARGS__)
  67 #else
  68 #define ext_debug(fmt, ...)     no_printk(fmt, ##__VA_ARGS__)
  69 #endif
  70
  71 #define EXT4_ERROR_INODE(inode, fmt, a...) \
  72         ext4_error_inode((inode), __func__, __LINE__, 0, (fmt), ## a)
  73
  74 #define EXT4_ERROR_INODE_BLOCK(inode, block, fmt, a...)                 \
  75         ext4_error_inode((inode), __func__, __LINE__, (block), (fmt), ## a)
  76
  77 #define EXT4_ERROR_FILE(file, block, fmt, a...)                         \
  78         ext4_error_file((file), __func__, __LINE__, (block), (fmt), ## a)
  79
  80 /* data type for block offset of block group */
  81 typedef int ext4_grpblk_t;
  82
  83 /* data type for filesystem-wide blocks number */
  84 typedef unsigned long long ext4_fsblk_t;
  85
  86 /* data type for file logical block number */
  87 typedef __u32 ext4_lblk_t;
  88
  89 /* data type for block group number */
  90 typedef unsigned int ext4_group_t;
  91
  92 /*
  93  * Flags used in mballoc's allocation_context flags field.
  94  *
  95  * Also used to show what's going on for debugging purposes when the
  96  * flag field is exported via the traceport interface
  97  */
  98
  99 /* prefer goal again. length */
 100 #define EXT4_MB_HINT_MERGE              0x0001
 101 /* blocks already reserved */
 102 #define EXT4_MB_HINT_RESERVED           0x0002
 103 /* metadata is being allocated */
 104 #define EXT4_MB_HINT_METADATA           0x0004
 105 /* first blocks in the file */
 106 #define EXT4_MB_HINT_FIRST              0x0008
 107 /* search for the best chunk */
 108 #define EXT4_MB_HINT_BEST               0x0010
 109 /* data is being allocated */
 110 #define EXT4_MB_HINT_DATA               0x0020
 111 /* don't preallocate (for tails) */
 112 #define EXT4_MB_HINT_NOPREALLOC         0x0040
 113 /* allocate for locality group */
 114 #define EXT4_MB_HINT_GROUP_ALLOC        0x0080
 115 /* allocate goal blocks or none */
 116 #define EXT4_MB_HINT_GOAL_ONLY          0x0100
 117 /* goal is meaningful */
 118 #define EXT4_MB_HINT_TRY_GOAL           0x0200
 119 /* blocks already pre-reserved by delayed allocation */
 120 #define EXT4_MB_DELALLOC_RESERVED       0x0400
 121 /* We are doing stream allocation */
 122 #define EXT4_MB_STREAM_ALLOC            0x0800
 123 /* Use reserved root blocks if needed */
 124 #define EXT4_MB_USE_ROOT_BLOCKS         0x1000
 125 /* Use blocks from reserved pool */
 126 #define EXT4_MB_USE_RESERVED            0x2000
 127
 128 struct ext4_allocation_request {
 129         /* target inode for block we're allocating */
 130         struct inode *inode;
 131         /* how many blocks we want to allocate */
 132         unsigned int len;
 133         /* logical block in target inode */
 134         ext4_lblk_t logical;
 135         /* the closest logical allocated block to the left */
 136         ext4_lblk_t lleft;
 137         /* the closest logical allocated block to the right */
 138         ext4_lblk_t lright;
 139         /* phys. target (a hint) */
 140         ext4_fsblk_t goal;
 141         /* phys. block for the closest logical allocated block to the left */
 142         ext4_fsblk_t pleft;
 143         /* phys. block for the closest logical allocated block to the right */
 144         ext4_fsblk_t pright;
 145         /* flags. see above EXT4_MB_HINT_* */
 146         unsigned int flags;
 147 };
 148
 149 /*
 150  * Logical to physical block mapping, used by ext4_map_blocks()
 151  *
 152  * This structure is used to pass requests into ext4_map_blocks() as
 153  * well as to store the information returned by ext4_map_blocks().  It
 154  * takes less room on the stack than a struct buffer_head.
 155  */
 156 #define EXT4_MAP_NEW            (1 << BH_New)
 157 #define EXT4_MAP_MAPPED         (1 << BH_Mapped)
 158 #define EXT4_MAP_UNWRITTEN      (1 << BH_Unwritten)
 159 #define EXT4_MAP_BOUNDARY       (1 << BH_Boundary)
 160 #define EXT4_MAP_UNINIT         (1 << BH_Uninit)
 161 /* Sometimes (in the bigalloc case, from ext4_da_get_block_prep) the caller of
 162  * ext4_map_blocks wants to know whether or not the underlying cluster has
 163  * already been accounted for. EXT4_MAP_FROM_CLUSTER conveys to the caller that
 164  * the requested mapping was from previously mapped (or delayed allocated)
 165  * cluster. We use BH_AllocFromCluster only for this flag. BH_AllocFromCluster
 166  * should never appear on buffer_head's state flags.
 167  */
 168 #define EXT4_MAP_FROM_CLUSTER   (1 << BH_AllocFromCluster)
 169 #define EXT4_MAP_FLAGS          (EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
 170                                  EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY |\
 171                                  EXT4_MAP_UNINIT | EXT4_MAP_FROM_CLUSTER)
 172
 173 struct ext4_map_blocks {
 174         ext4_fsblk_t m_pblk;
 175         ext4_lblk_t m_lblk;
 176         unsigned int m_len;
 177         unsigned int m_flags;
 178 };
 179
 180 /*
 181  * Flags for ext4_io_end->flags
 182  */
 183 #define EXT4_IO_END_UNWRITTEN   0x0001
 184
 185 /*
 186  * For converting uninitialized extents on a work queue. 'handle' is used for
 187  * buffered writeback.
 188  */
 189 typedef struct ext4_io_end {
 190         struct list_head        list;           /* per-file finished IO list */
 191         handle_t                *handle;        /* handle reserved for extent
 192                                                  * conversion */
 193         struct inode            *inode;         /* file being written to */
 194         struct bio              *bio;           /* Linked list of completed
 195                                                  * bios covering the extent */
 196         unsigned int            flag;           /* unwritten or not */
 197         loff_t                  offset;         /* offset in the file */
 198         ssize_t                 size;           /* size of the extent */
 199         atomic_t                count;          /* reference counter */
 200 } ext4_io_end_t;
 201
 202 struct ext4_io_submit {
 203         int                     io_op;
 204         struct bio              *io_bio;
 205         ext4_io_end_t           *io_end;
 206         sector_t                io_next_block;
 207 };
 208
 209 /*
 210  * Special inodes numbers
 211  */
 212 #define EXT4_BAD_INO             1      /* Bad blocks inode */
 213 #define EXT4_ROOT_INO            2      /* Root inode */
 214 #define EXT4_USR_QUOTA_INO       3      /* User quota inode */
 215 #define EXT4_GRP_QUOTA_INO       4      /* Group quota inode */
 216 #define EXT4_BOOT_LOADER_INO     5      /* Boot loader inode */
 217 #define EXT4_UNDEL_DIR_INO       6      /* Undelete directory inode */
 218 #define EXT4_RESIZE_INO          7      /* Reserved group descriptors inode */
 219 #define EXT4_JOURNAL_INO         8      /* Journal inode */
 220
 221 /* First non-reserved inode for old ext4 filesystems */
 222 #define EXT4_GOOD_OLD_FIRST_INO 11
 223
 224 /*
 225  * Maximal count of links to a file
 226  */
 227 #define EXT4_LINK_MAX           65000
 228
 229 /*
 230  * Macro-instructions used to manage several block sizes
 231  */
 232 #define EXT4_MIN_BLOCK_SIZE             1024
 233 #define EXT4_MAX_BLOCK_SIZE             65536
 234 #define EXT4_MIN_BLOCK_LOG_SIZE         10
 235 #define EXT4_MAX_BLOCK_LOG_SIZE         16
 236 #ifdef __KERNEL__
 237 # define EXT4_BLOCK_SIZE(s)             ((s)->s_blocksize)
 238 #else
 239 # define EXT4_BLOCK_SIZE(s)             (EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
 240 #endif
 241 #define EXT4_ADDR_PER_BLOCK(s)          (EXT4_BLOCK_SIZE(s) / sizeof(__u32))
 242 #define EXT4_CLUSTER_SIZE(s)            (EXT4_BLOCK_SIZE(s) << \
 243                                          EXT4_SB(s)->s_cluster_bits)
 244 #ifdef __KERNEL__
 245 # define EXT4_BLOCK_SIZE_BITS(s)        ((s)->s_blocksize_bits)
 246 # define EXT4_CLUSTER_BITS(s)           (EXT4_SB(s)->s_cluster_bits)
 247 #else
 248 # define EXT4_BLOCK_SIZE_BITS(s)        ((s)->s_log_block_size + 10)
 249 #endif
 250 #ifdef __KERNEL__
 251 #define EXT4_ADDR_PER_BLOCK_BITS(s)     (EXT4_SB(s)->s_addr_per_block_bits)
 252 #define EXT4_INODE_SIZE(s)              (EXT4_SB(s)->s_inode_size)
 253 #define EXT4_FIRST_INO(s)               (EXT4_SB(s)->s_first_ino)
 254 #else
 255 #define EXT4_INODE_SIZE(s)      (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
 256                                  EXT4_GOOD_OLD_INODE_SIZE : \
 257                                  (s)->s_inode_size)
 258 #define EXT4_FIRST_INO(s)       (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
 259                                  EXT4_GOOD_OLD_FIRST_INO : \
 260                                  (s)->s_first_ino)
 261 #endif
 262 #define EXT4_BLOCK_ALIGN(size, blkbits)         ALIGN((size), (1 << (blkbits)))
 263
 264 /* Translate a block number to a cluster number */
 265 #define EXT4_B2C(sbi, blk)      ((blk) >> (sbi)->s_cluster_bits)
 266 /* Translate a cluster number to a block number */
 267 #define EXT4_C2B(sbi, cluster)  ((cluster) << (sbi)->s_cluster_bits)
 268 /* Translate # of blks to # of clusters */
 269 #define EXT4_NUM_B2C(sbi, blks) (((blks) + (sbi)->s_cluster_ratio - 1) >> \
 270                                  (sbi)->s_cluster_bits)
 271 /* Mask out the low bits to get the starting block of the cluster */
 272 #define EXT4_PBLK_CMASK(s, pblk) ((pblk) &                              \
 273                                   ~((ext4_fsblk_t) (s)->s_cluster_ratio - 1))
 274 #define EXT4_LBLK_CMASK(s, lblk) ((lblk) &                              \
 275                                   ~((ext4_lblk_t) (s)->s_cluster_ratio - 1))
 276 /* Get the cluster offset */
 277 #define EXT4_PBLK_COFF(s, pblk) ((pblk) &                               \
 278                                  ((ext4_fsblk_t) (s)->s_cluster_ratio - 1))
 279 #define EXT4_LBLK_COFF(s, lblk) ((lblk) &                               \
 280                                  ((ext4_lblk_t) (s)->s_cluster_ratio - 1))
 281
 282 /*
 283  * Structure of a blocks group descriptor
 284  */
 285 struct ext4_group_desc
 286 {
 287         __le32  bg_block_bitmap_lo;     /* Blocks bitmap block */
 288         __le32  bg_inode_bitmap_lo;     /* Inodes bitmap block */
 289         __le32  bg_inode_table_lo;      /* Inodes table block */
 290         __le16  bg_free_blocks_count_lo;/* Free blocks count */
 291         __le16  bg_free_inodes_count_lo;/* Free inodes count */
 292         __le16  bg_used_dirs_count_lo;  /* Directories count */
 293         __le16  bg_flags;               /* EXT4_BG_flags (INODE_UNINIT, etc) */
 294         __le32  bg_exclude_bitmap_lo;   /* Exclude bitmap for snapshots */
 295         __le16  bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bbitmap) LE */
 296         __le16  bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+ibitmap) LE */
 297         __le16  bg_itable_unused_lo;    /* Unused inodes count */
 298         __le16  bg_checksum;            /* crc16(sb_uuid+group+desc) */
 299         __le32  bg_block_bitmap_hi;     /* Blocks bitmap block MSB */
 300         __le32  bg_inode_bitmap_hi;     /* Inodes bitmap block MSB */
 301         __le32  bg_inode_table_hi;      /* Inodes table block MSB */
 302         __le16  bg_free_blocks_count_hi;/* Free blocks count MSB */
 303         __le16  bg_free_inodes_count_hi;/* Free inodes count MSB */
 304         __le16  bg_used_dirs_count_hi;  /* Directories count MSB */
 305         __le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
 306         __le32  bg_exclude_bitmap_hi;   /* Exclude bitmap block MSB */
 307         __le16  bg_block_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bbitmap) BE */
 308         __le16  bg_inode_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+ibitmap) BE */
 309         __u32   bg_reserved;
 310 };
 311
 312 #define EXT4_BG_INODE_BITMAP_CSUM_HI_END        \
 313         (offsetof(struct ext4_group_desc, bg_inode_bitmap_csum_hi) + \
 314          sizeof(__le16))
 315 #define EXT4_BG_BLOCK_BITMAP_CSUM_HI_END        \
 316         (offsetof(struct ext4_group_desc, bg_block_bitmap_csum_hi) + \
 317          sizeof(__le16))
 318
 319 /*
 320  * Structure of a flex block group info
 321  */
 322
 323 struct flex_groups {
 324         atomic64_t      free_clusters;
 325         atomic_t        free_inodes;
 326         atomic_t        used_dirs;
 327 };
 328
 329 #define EXT4_BG_INODE_UNINIT    0x0001 /* Inode table/bitmap not in use */
 330 #define EXT4_BG_BLOCK_UNINIT    0x0002 /* Block bitmap not in use */
 331 #define EXT4_BG_INODE_ZEROED    0x0004 /* On-disk itable initialized to zero */
 332
 333 /*
 334  * Macro-instructions used to manage group descriptors
 335  */
 336 #define EXT4_MIN_DESC_SIZE              32
 337 #define EXT4_MIN_DESC_SIZE_64BIT        64
 338 #define EXT4_MAX_DESC_SIZE              EXT4_MIN_BLOCK_SIZE
 339 #define EXT4_DESC_SIZE(s)               (EXT4_SB(s)->s_desc_size)
 340 #ifdef __KERNEL__
 341 # define EXT4_BLOCKS_PER_GROUP(s)       (EXT4_SB(s)->s_blocks_per_group)
 342 # define EXT4_CLUSTERS_PER_GROUP(s)     (EXT4_SB(s)->s_clusters_per_group)
 343 # define EXT4_DESC_PER_BLOCK(s)         (EXT4_SB(s)->s_desc_per_block)
 344 # define EXT4_INODES_PER_GROUP(s)       (EXT4_SB(s)->s_inodes_per_group)
 345 # define EXT4_DESC_PER_BLOCK_BITS(s)    (EXT4_SB(s)->s_desc_per_block_bits)
 346 #else
 347 # define EXT4_BLOCKS_PER_GROUP(s)       ((s)->s_blocks_per_group)
 348 # define EXT4_DESC_PER_BLOCK(s)         (EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
 349 # define EXT4_INODES_PER_GROUP(s)       ((s)->s_inodes_per_group)
 350 #endif
 351
 352 /*
 353  * Constants relative to the data blocks
 354  */
 355 #define EXT4_NDIR_BLOCKS                12
 356 #define EXT4_IND_BLOCK                  EXT4_NDIR_BLOCKS
 357 #define EXT4_DIND_BLOCK                 (EXT4_IND_BLOCK + 1)
 358 #define EXT4_TIND_BLOCK                 (EXT4_DIND_BLOCK + 1)
 359 #define EXT4_N_BLOCKS                   (EXT4_TIND_BLOCK + 1)
 360
 361 /*
 362  * Inode flags
 363  */
 364 #define EXT4_SECRM_FL                   0x00000001 /* Secure deletion */
 365 #define EXT4_UNRM_FL                    0x00000002 /* Undelete */
 366 #define EXT4_COMPR_FL                   0x00000004 /* Compress file */
 367 #define EXT4_SYNC_FL                    0x00000008 /* Synchronous updates */
 368 #define EXT4_IMMUTABLE_FL               0x00000010 /* Immutable file */
 369 #define EXT4_APPEND_FL                  0x00000020 /* writes to file may only append */
 370 #define EXT4_NODUMP_FL                  0x00000040 /* do not dump file */
 371 #define EXT4_NOATIME_FL                 0x00000080 /* do not update atime */
 372 /* Reserved for compression usage... */
 373 #define EXT4_DIRTY_FL                   0x00000100
 374 #define EXT4_COMPRBLK_FL                0x00000200 /* One or more compressed clusters */
 375 #define EXT4_NOCOMPR_FL                 0x00000400 /* Don't compress */
 376 #define EXT4_ECOMPR_FL                  0x00000800 /* Compression error */
 377 /* End compression flags --- maybe not all used */
 378 #define EXT4_INDEX_FL                   0x00001000 /* hash-indexed directory */
 379 #define EXT4_IMAGIC_FL                  0x00002000 /* AFS directory */
 380 #define EXT4_JOURNAL_DATA_FL            0x00004000 /* file data should be journaled */
 381 #define EXT4_NOTAIL_FL                  0x00008000 /* file tail should not be merged */
 382 #define EXT4_DIRSYNC_FL                 0x00010000 /* dirsync behaviour (directories only) */
 383 #define EXT4_TOPDIR_FL                  0x00020000 /* Top of directory hierarchies*/
 384 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
 385 #define EXT4_EXTENTS_FL                 0x00080000 /* Inode uses extents */
 386 #define EXT4_EA_INODE_FL                0x00200000 /* Inode used for large EA */
 387 #define EXT4_EOFBLOCKS_FL               0x00400000 /* Blocks allocated beyond EOF */
 388 #define EXT4_INLINE_DATA_FL             0x10000000 /* Inode has inline data. */
 389 #define EXT4_RESERVED_FL                0x80000000 /* reserved for ext4 lib */
 390
 391 #define EXT4_FL_USER_VISIBLE            0x004BDFFF /* User visible flags */
 392 #define EXT4_FL_USER_MODIFIABLE         0x004380FF /* User modifiable flags */
 393
 394 /* Flags that should be inherited by new inodes from their parent. */
 395 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
 396                            EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
 397                            EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
 398                            EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
 399
 400 /* Flags that are appropriate for regular files (all but dir-specific ones). */
 401 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
 402
 403 /* Flags that are appropriate for non-directories/regular files. */
 404 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
 405
 406 /* Mask out flags that are inappropriate for the given type of inode. */
 407 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
 408 {
 409         if (S_ISDIR(mode))
 410                 return flags;
 411         else if (S_ISREG(mode))
 412                 return flags & EXT4_REG_FLMASK;
 413         else
 414                 return flags & EXT4_OTHER_FLMASK;
 415 }
 416
 417 /*
 418  * Inode flags used for atomic set/get
 419  */
 420 enum {
 421         EXT4_INODE_SECRM        = 0,    /* Secure deletion */
 422         EXT4_INODE_UNRM         = 1,    /* Undelete */
 423         EXT4_INODE_COMPR        = 2,    /* Compress file */
 424         EXT4_INODE_SYNC         = 3,    /* Synchronous updates */
 425         EXT4_INODE_IMMUTABLE    = 4,    /* Immutable file */
 426         EXT4_INODE_APPEND       = 5,    /* writes to file may only append */
 427         EXT4_INODE_NODUMP       = 6,    /* do not dump file */
 428         EXT4_INODE_NOATIME      = 7,    /* do not update atime */
 429 /* Reserved for compression usage... */
 430         EXT4_INODE_DIRTY        = 8,
 431         EXT4_INODE_COMPRBLK     = 9,    /* One or more compressed clusters */
 432         EXT4_INODE_NOCOMPR      = 10,   /* Don't compress */
 433         EXT4_INODE_ECOMPR       = 11,   /* Compression error */
 434 /* End compression flags --- maybe not all used */
 435         EXT4_INODE_INDEX        = 12,   /* hash-indexed directory */
 436         EXT4_INODE_IMAGIC       = 13,   /* AFS directory */
 437         EXT4_INODE_JOURNAL_DATA = 14,   /* file data should be journaled */
 438         EXT4_INODE_NOTAIL       = 15,   /* file tail should not be merged */
 439         EXT4_INODE_DIRSYNC      = 16,   /* dirsync behaviour (directories only) */
 440         EXT4_INODE_TOPDIR       = 17,   /* Top of directory hierarchies*/
 441         EXT4_INODE_HUGE_FILE    = 18,   /* Set to each huge file */
 442         EXT4_INODE_EXTENTS      = 19,   /* Inode uses extents */
 443         EXT4_INODE_EA_INODE     = 21,   /* Inode used for large EA */
 444         EXT4_INODE_EOFBLOCKS    = 22,   /* Blocks allocated beyond EOF */
 445         EXT4_INODE_INLINE_DATA  = 28,   /* Data in inode. */
 446         EXT4_INODE_RESERVED     = 31,   /* reserved for ext4 lib */
 447 };
 448
 449 /*
 450  * Since it's pretty easy to mix up bit numbers and hex values, we use a
 451  * build-time check to make sure that EXT4_XXX_FL is consistent with respect to
 452  * EXT4_INODE_XXX. If all is well, the macros will be dropped, so, it won't cost
 453  * any extra space in the compiled kernel image, otherwise, the build will fail.
 454  * It's important that these values are the same, since we are using
 455  * EXT4_INODE_XXX to test for flag values, but EXT4_XXX_FL must be consistent
 456  * with the values of FS_XXX_FL defined in include/linux/fs.h and the on-disk
 457  * values found in ext2, ext3 and ext4 filesystems, and of course the values
 458  * defined in e2fsprogs.
 459  *
 460  * It's not paranoia if the Murphy's Law really *is* out to get you.  :-)
 461  */
 462 #define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1 << EXT4_INODE_##FLAG))
 463 #define CHECK_FLAG_VALUE(FLAG) BUILD_BUG_ON(!TEST_FLAG_VALUE(FLAG))
 464
 465 static inline void ext4_check_flag_values(void)
 466 {
 467         CHECK_FLAG_VALUE(SECRM);
 468         CHECK_FLAG_VALUE(UNRM);
 469         CHECK_FLAG_VALUE(COMPR);
 470         CHECK_FLAG_VALUE(SYNC);
 471         CHECK_FLAG_VALUE(IMMUTABLE);
 472         CHECK_FLAG_VALUE(APPEND);
 473         CHECK_FLAG_VALUE(NODUMP);
 474         CHECK_FLAG_VALUE(NOATIME);
 475         CHECK_FLAG_VALUE(DIRTY);
 476         CHECK_FLAG_VALUE(COMPRBLK);
 477         CHECK_FLAG_VALUE(NOCOMPR);
 478         CHECK_FLAG_VALUE(ECOMPR);
 479         CHECK_FLAG_VALUE(INDEX);
 480         CHECK_FLAG_VALUE(IMAGIC);
 481         CHECK_FLAG_VALUE(JOURNAL_DATA);
 482         CHECK_FLAG_VALUE(NOTAIL);
 483         CHECK_FLAG_VALUE(DIRSYNC);
 484         CHECK_FLAG_VALUE(TOPDIR);
 485         CHECK_FLAG_VALUE(HUGE_FILE);
 486         CHECK_FLAG_VALUE(EXTENTS);
 487         CHECK_FLAG_VALUE(EA_INODE);
 488         CHECK_FLAG_VALUE(EOFBLOCKS);
 489         CHECK_FLAG_VALUE(INLINE_DATA);
 490         CHECK_FLAG_VALUE(RESERVED);
 491 }
 492
 493 /* Used to pass group descriptor data when online resize is done */
 494 struct ext4_new_group_input {
 495         __u32 group;            /* Group number for this data */
 496         __u64 block_bitmap;     /* Absolute block number of block bitmap */
 497         __u64 inode_bitmap;     /* Absolute block number of inode bitmap */
 498         __u64 inode_table;      /* Absolute block number of inode table start */
 499         __u32 blocks_count;     /* Total number of blocks in this group */
 500         __u16 reserved_blocks;  /* Number of reserved blocks in this group */
 501         __u16 unused;
 502 };
 503
 504 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
 505 struct compat_ext4_new_group_input {
 506         u32 group;
 507         compat_u64 block_bitmap;
 508         compat_u64 inode_bitmap;
 509         compat_u64 inode_table;
 510         u32 blocks_count;
 511         u16 reserved_blocks;
 512         u16 unused;
 513 };
 514 #endif
 515
 516 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
 517 struct ext4_new_group_data {
 518         __u32 group;
 519         __u64 block_bitmap;
 520         __u64 inode_bitmap;
 521         __u64 inode_table;
 522         __u32 blocks_count;
 523         __u16 reserved_blocks;
 524         __u16 unused;
 525         __u32 free_blocks_count;
 526 };
 527
 528 /* Indexes used to index group tables in ext4_new_group_data */
 529 enum {
 530         BLOCK_BITMAP = 0,       /* block bitmap */
 531         INODE_BITMAP,           /* inode bitmap */
 532         INODE_TABLE,            /* inode tables */
 533         GROUP_TABLE_COUNT,
 534 };
 535
 536 /*
 537  * Flags used by ext4_map_blocks()
 538  */
 539         /* Allocate any needed blocks and/or convert an unitialized
 540            extent to be an initialized ext4 */
 541 #define EXT4_GET_BLOCKS_CREATE                  0x0001
 542         /* Request the creation of an unitialized extent */
 543 #define EXT4_GET_BLOCKS_UNINIT_EXT              0x0002
 544 #define EXT4_GET_BLOCKS_CREATE_UNINIT_EXT       (EXT4_GET_BLOCKS_UNINIT_EXT|\
 545                                                  EXT4_GET_BLOCKS_CREATE)
 546         /* Caller is from the delayed allocation writeout path
 547          * finally doing the actual allocation of delayed blocks */
 548 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE        0x0004
 549         /* caller is from the direct IO path, request to creation of an
 550         unitialized extents if not allocated, split the uninitialized
 551         extent if blocks has been preallocated already*/
 552 #define EXT4_GET_BLOCKS_PRE_IO                  0x0008
 553 #define EXT4_GET_BLOCKS_CONVERT                 0x0010
 554 #define EXT4_GET_BLOCKS_IO_CREATE_EXT           (EXT4_GET_BLOCKS_PRE_IO|\
 555                                          EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
 556         /* Convert extent to initialized after IO complete */
 557 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT          (EXT4_GET_BLOCKS_CONVERT|\
 558                                          EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
 559         /* Eventual metadata allocation (due to growing extent tree)
 560          * should not fail, so try to use reserved blocks for that.*/
 561 #define EXT4_GET_BLOCKS_METADATA_NOFAIL         0x0020
 562         /* Don't normalize allocation size (used for fallocate) */
 563 #define EXT4_GET_BLOCKS_NO_NORMALIZE            0x0040
 564         /* Request will not result in inode size update (user for fallocate) */
 565 #define EXT4_GET_BLOCKS_KEEP_SIZE               0x0080
 566         /* Do not take i_data_sem locking in ext4_map_blocks */
 567 #define EXT4_GET_BLOCKS_NO_LOCK                 0x0100
 568         /* Do not put hole in extent cache */
 569 #define EXT4_GET_BLOCKS_NO_PUT_HOLE             0x0200
 570
 571 /*
 572  * The bit position of these flags must not overlap with any of the
 573  * EXT4_GET_BLOCKS_*.  They are used by ext4_ext_find_extent(),
 574  * read_extent_tree_block(), ext4_split_extent_at(),
 575  * ext4_ext_insert_extent(), and ext4_ext_create_new_leaf().
 576  * EXT4_EX_NOCACHE is used to indicate that the we shouldn't be
 577  * caching the extents when reading from the extent tree while a
 578  * truncate or punch hole operation is in progress.
 579  */
 580 #define EXT4_EX_NOCACHE                         0x0400
 581 #define EXT4_EX_FORCE_CACHE                     0x0800
 582
 583 /*
 584  * Flags used by ext4_free_blocks
 585  */
 586 #define EXT4_FREE_BLOCKS_METADATA       0x0001
 587 #define EXT4_FREE_BLOCKS_FORGET         0x0002
 588 #define EXT4_FREE_BLOCKS_VALIDATED      0x0004
 589 #define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE 0x0008
 590 #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER   0x0010
 591 #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER    0x0020
 592 #define EXT4_FREE_BLOCKS_RESERVE                0x0040
 593
 594 /*
 595  * ioctl commands
 596  */
 597 #define EXT4_IOC_GETFLAGS               FS_IOC_GETFLAGS
 598 #define EXT4_IOC_SETFLAGS               FS_IOC_SETFLAGS
 599 #define EXT4_IOC_GETVERSION             _IOR('f', 3, long)
 600 #define EXT4_IOC_SETVERSION             _IOW('f', 4, long)
 601 #define EXT4_IOC_GETVERSION_OLD         FS_IOC_GETVERSION
 602 #define EXT4_IOC_SETVERSION_OLD         FS_IOC_SETVERSION
 603 #define EXT4_IOC_GETRSVSZ               _IOR('f', 5, long)
 604 #define EXT4_IOC_SETRSVSZ               _IOW('f', 6, long)
 605 #define EXT4_IOC_GROUP_EXTEND           _IOW('f', 7, unsigned long)
 606 #define EXT4_IOC_GROUP_ADD              _IOW('f', 8, struct ext4_new_group_input)
 607 #define EXT4_IOC_MIGRATE                _IO('f', 9)
 608  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
 609  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
 610 #define EXT4_IOC_ALLOC_DA_BLKS          _IO('f', 12)
 611 #define EXT4_IOC_MOVE_EXT               _IOWR('f', 15, struct move_extent)
 612 #define EXT4_IOC_RESIZE_FS              _IOW('f', 16, __u64)
 613 #define EXT4_IOC_SWAP_BOOT              _IO('f', 17)
 614 #define EXT4_IOC_PRECACHE_EXTENTS       _IO('f', 18)
 615
 616 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
 617 /*
 618  * ioctl commands in 32 bit emulation
 619  */
 620 #define EXT4_IOC32_GETFLAGS             FS_IOC32_GETFLAGS
 621 #define EXT4_IOC32_SETFLAGS             FS_IOC32_SETFLAGS
 622 #define EXT4_IOC32_GETVERSION           _IOR('f', 3, int)
 623 #define EXT4_IOC32_SETVERSION           _IOW('f', 4, int)
 624 #define EXT4_IOC32_GETRSVSZ             _IOR('f', 5, int)
 625 #define EXT4_IOC32_SETRSVSZ             _IOW('f', 6, int)
 626 #define EXT4_IOC32_GROUP_EXTEND         _IOW('f', 7, unsigned int)
 627 #define EXT4_IOC32_GROUP_ADD            _IOW('f', 8, struct compat_ext4_new_group_input)
 628 #define EXT4_IOC32_GETVERSION_OLD       FS_IOC32_GETVERSION
 629 #define EXT4_IOC32_SETVERSION_OLD       FS_IOC32_SETVERSION
 630 #endif
 631
 632 /* Max physical block we can address w/o extents */
 633 #define EXT4_MAX_BLOCK_FILE_PHYS        0xFFFFFFFF
 634
 635 /*
 636  * Structure of an inode on the disk
 637  */
 638 struct ext4_inode {
 639         __le16  i_mode;         /* File mode */
 640         __le16  i_uid;          /* Low 16 bits of Owner Uid */
 641         __le32  i_size_lo;      /* Size in bytes */
 642         __le32  i_atime;        /* Access time */
 643         __le32  i_ctime;        /* Inode Change time */
 644         __le32  i_mtime;        /* Modification time */
 645         __le32  i_dtime;        /* Deletion Time */
 646         __le16  i_gid;          /* Low 16 bits of Group Id */
 647         __le16  i_links_count;  /* Links count */
 648         __le32  i_blocks_lo;    /* Blocks count */
 649         __le32  i_flags;        /* File flags */
 650         union {
 651                 struct {
 652                         __le32  l_i_version;
 653                 } linux1;
 654                 struct {
 655                         __u32  h_i_translator;
 656                 } hurd1;
 657                 struct {
 658                         __u32  m_i_reserved1;
 659                 } masix1;
 660         } osd1;                         /* OS dependent 1 */
 661         __le32  i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
 662         __le32  i_generation;   /* File version (for NFS) */
 663         __le32  i_file_acl_lo;  /* File ACL */
 664         __le32  i_size_high;
 665         __le32  i_obso_faddr;   /* Obsoleted fragment address */
 666         union {
 667                 struct {
 668                         __le16  l_i_blocks_high; /* were l_i_reserved1 */
 669                         __le16  l_i_file_acl_high;
 670                         __le16  l_i_uid_high;   /* these 2 fields */
 671                         __le16  l_i_gid_high;   /* were reserved2[0] */
 672                         __le16  l_i_checksum_lo;/* crc32c(uuid+inum+inode) LE */
 673                         __le16  l_i_reserved;
 674                 } linux2;
 675                 struct {
 676                         __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
 677                         __u16   h_i_mode_high;
 678                         __u16   h_i_uid_high;
 679                         __u16   h_i_gid_high;
 680                         __u32   h_i_author;
 681                 } hurd2;
 682                 struct {
 683                         __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
 684                         __le16  m_i_file_acl_high;
 685                         __u32   m_i_reserved2[2];
 686                 } masix2;
 687         } osd2;                         /* OS dependent 2 */
 688         __le16  i_extra_isize;
 689         __le16  i_checksum_hi;  /* crc32c(uuid+inum+inode) BE */
 690         __le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
 691         __le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
 692         __le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
 693         __le32  i_crtime;       /* File Creation time */
 694         __le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
 695         __le32  i_version_hi;   /* high 32 bits for 64-bit version */
 696 };
 697
 698 struct move_extent {
 699         __u32 reserved;         /* should be zero */
 700         __u32 donor_fd;         /* donor file descriptor */
 701         __u64 orig_start;       /* logical start offset in block for orig */
 702         __u64 donor_start;      /* logical start offset in block for donor */
 703         __u64 len;              /* block length to be moved */
 704         __u64 moved_len;        /* moved block length */
 705 };
 706
 707 #define EXT4_EPOCH_BITS 2
 708 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
 709 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
 710
 711 /*
 712  * Extended fields will fit into an inode if the filesystem was formatted
 713  * with large inodes (-I 256 or larger) and there are not currently any EAs
 714  * consuming all of the available space. For new inodes we always reserve
 715  * enough space for the kernel's known extended fields, but for inodes
 716  * created with an old kernel this might not have been the case. None of
 717  * the extended inode fields is critical for correct filesystem operation.
 718  * This macro checks if a certain field fits in the inode. Note that
 719  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
 720  */
 721 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)   \
 722         ((offsetof(typeof(*ext4_inode), field) +        \
 723           sizeof((ext4_inode)->field))                  \
 724         <= (EXT4_GOOD_OLD_INODE_SIZE +                  \
 725             (einode)->i_extra_isize))                   \
 726
 727 static inline __le32 ext4_encode_extra_time(struct timespec *time)
 728 {
 729        return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
 730                            (time->tv_sec >> 32) & EXT4_EPOCH_MASK : 0) |
 731                           ((time->tv_nsec << EXT4_EPOCH_BITS) & EXT4_NSEC_MASK));
 732 }
 733
 734 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
 735 {
 736        if (sizeof(time->tv_sec) > 4)
 737                time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
 738                                << 32;
 739        time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
 740 }
 741
 742 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)                          \
 743 do {                                                                           \
 744         (raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);               \
 745         if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
 746                 (raw_inode)->xtime ## _extra =                                 \
 747                                 ext4_encode_extra_time(&(inode)->xtime);       \
 748 } while (0)
 749
 750 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)                        \
 751 do {                                                                           \
 752         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))                      \
 753                 (raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
 754         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))            \
 755                 (raw_inode)->xtime ## _extra =                                 \
 756                                 ext4_encode_extra_time(&(einode)->xtime);      \
 757 } while (0)
 758
 759 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)                          \
 760 do {                                                                           \
 761         (inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
 762         if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
 763                 ext4_decode_extra_time(&(inode)->xtime,                        \
 764                                        raw_inode->xtime ## _extra);            \
 765         else                                                                   \
 766                 (inode)->xtime.tv_nsec = 0;                                    \
 767 } while (0)
 768
 769 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)                        \
 770 do {                                                                           \
 771         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))                      \
 772                 (einode)->xtime.tv_sec =                                       \
 773                         (signed)le32_to_cpu((raw_inode)->xtime);               \
 774         else                                                                   \
 775                 (einode)->xtime.tv_sec = 0;                                    \
 776         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))            \
 777                 ext4_decode_extra_time(&(einode)->xtime,                       \
 778                                        raw_inode->xtime ## _extra);            \
 779         else                                                                   \
 780                 (einode)->xtime.tv_nsec = 0;                                   \
 781 } while (0)
 782
 783 #define i_disk_version osd1.linux1.l_i_version
 784
 785 #if defined(__KERNEL__) || defined(__linux__)
 786 #define i_reserved1     osd1.linux1.l_i_reserved1
 787 #define i_file_acl_high osd2.linux2.l_i_file_acl_high
 788 #define i_blocks_high   osd2.linux2.l_i_blocks_high
 789 #define i_uid_low       i_uid
 790 #define i_gid_low       i_gid
 791 #define i_uid_high      osd2.linux2.l_i_uid_high
 792 #define i_gid_high      osd2.linux2.l_i_gid_high
 793 #define i_checksum_lo   osd2.linux2.l_i_checksum_lo
 794
 795 #elif defined(__GNU__)
 796
 797 #define i_translator    osd1.hurd1.h_i_translator
 798 #define i_uid_high      osd2.hurd2.h_i_uid_high
 799 #define i_gid_high      osd2.hurd2.h_i_gid_high
 800 #define i_author        osd2.hurd2.h_i_author
 801
 802 #elif defined(__masix__)
 803
 804 #define i_reserved1     osd1.masix1.m_i_reserved1
 805 #define i_file_acl_high osd2.masix2.m_i_file_acl_high
 806 #define i_reserved2     osd2.masix2.m_i_reserved2
 807
 808 #endif /* defined(__KERNEL__) || defined(__linux__) */
 809
 810 #include "extents_status.h"
 811
 812 /*
 813  * fourth extended file system inode data in memory
 814  */
 815 struct ext4_inode_info {
 816         __le32  i_data[15];     /* unconverted */
 817         __u32   i_dtime;
 818         ext4_fsblk_t    i_file_acl;
 819
 820         /*
 821          * i_block_group is the number of the block group which contains
 822          * this file's inode.  Constant across the lifetime of the inode,
 823          * it is ued for making block allocation decisions - we try to
 824          * place a file's data blocks near its inode block, and new inodes
 825          * near to their parent directory's inode.
 826          */
 827         ext4_group_t    i_block_group;
 828         ext4_lblk_t     i_dir_start_lookup;
 829 #if (BITS_PER_LONG < 64)
 830         unsigned long   i_state_flags;          /* Dynamic state flags */
 831 #endif
 832         unsigned long   i_flags;
 833
 834         /*
 835          * Extended attributes can be read independently of the main file
 836          * data. Taking i_mutex even when reading would cause contention
 837          * between readers of EAs and writers of regular file data, so
 838          * instead we synchronize on xattr_sem when reading or changing
 839          * EAs.
 840          */
 841         struct rw_semaphore xattr_sem;
 842
 843         struct list_head i_orphan;      /* unlinked but open inodes */
 844
 845         /*
 846          * i_disksize keeps track of what the inode size is ON DISK, not
 847          * in memory.  During truncate, i_size is set to the new size by
 848          * the VFS prior to calling ext4_truncate(), but the filesystem won't
 849          * set i_disksize to 0 until the truncate is actually under way.
 850          *
 851          * The intent is that i_disksize always represents the blocks which
 852          * are used by this file.  This allows recovery to restart truncate
 853          * on orphans if we crash during truncate.  We actually write i_disksize
 854          * into the on-disk inode when writing inodes out, instead of i_size.
 855          *
 856          * The only time when i_disksize and i_size may be different is when
 857          * a truncate is in progress.  The only things which change i_disksize
 858          * are ext4_get_block (growth) and ext4_truncate (shrinkth).
 859          */
 860         loff_t  i_disksize;
 861
 862         /*
 863          * i_data_sem is for serialising ext4_truncate() against
 864          * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
 865          * data tree are chopped off during truncate. We can't do that in
 866          * ext4 because whenever we perform intermediate commits during
 867          * truncate, the inode and all the metadata blocks *must* be in a
 868          * consistent state which allows truncation of the orphans to restart
 869          * during recovery.  Hence we must fix the get_block-vs-truncate race
 870          * by other means, so we have i_data_sem.
 871          */
 872         struct rw_semaphore i_data_sem;
 873         struct inode vfs_inode;
 874         struct jbd2_inode *jinode;
 875
 876         /*
 877          * File creation time. Its function is same as that of
 878          * struct timespec i_{a,c,m}time in the generic inode.
 879          */
 880         struct timespec i_crtime;
 881
 882         /* mballoc */
 883         struct list_head i_prealloc_list;
 884         spinlock_t i_prealloc_lock;
 885
 886         /* extents status tree */
 887         struct ext4_es_tree i_es_tree;
 888         rwlock_t i_es_lock;
 889         struct list_head i_es_lru;
 890         unsigned int i_es_lru_nr;       /* protected by i_es_lock */
 891         unsigned long i_touch_when;     /* jiffies of last accessing */
 892
 893         /* ialloc */
 894         ext4_group_t    i_last_alloc_group;
 895
 896         /* allocation reservation info for delalloc */
 897         /* In case of bigalloc, these refer to clusters rather than blocks */
 898         unsigned int i_reserved_data_blocks;
 899         unsigned int i_reserved_meta_blocks;
 900         unsigned int i_allocated_meta_blocks;
 901         ext4_lblk_t i_da_metadata_calc_last_lblock;
 902         int i_da_metadata_calc_len;
 903
 904         /* on-disk additional length */
 905         __u16 i_extra_isize;
 906
 907         /* Indicate the inline data space. */
 908         u16 i_inline_off;
 909         u16 i_inline_size;
 910
 911 #ifdef CONFIG_QUOTA
 912         /* quota space reservation, managed internally by quota code */
 913         qsize_t i_reserved_quota;
 914 #endif
 915
 916         /* Lock protecting lists below */
 917         spinlock_t i_completed_io_lock;
 918         /*
 919          * Completed IOs that need unwritten extents handling and have
 920          * transaction reserved
 921          */
 922         struct list_head i_rsv_conversion_list;
 923         /*
 924          * Completed IOs that need unwritten extents handling and don't have
 925          * transaction reserved
 926          */
 927         atomic_t i_ioend_count; /* Number of outstanding io_end structs */
 928         atomic_t i_unwritten; /* Nr. of inflight conversions pending */
 929         struct work_struct i_rsv_conversion_work;
 930
 931         spinlock_t i_block_reservation_lock;
 932
 933         /*
 934          * Transactions that contain inode's metadata needed to complete
 935          * fsync and fdatasync, respectively.
 936          */
 937         tid_t i_sync_tid;
 938         tid_t i_datasync_tid;
 939
 940         /* Precomputed uuid+inum+igen checksum for seeding inode checksums */
 941         __u32 i_csum_seed;
 942 };
 943
 944 /*
 945  * File system states
 946  */
 947 #define EXT4_VALID_FS                   0x0001  /* Unmounted cleanly */
 948 #define EXT4_ERROR_FS                   0x0002  /* Errors detected */
 949 #define EXT4_ORPHAN_FS                  0x0004  /* Orphans being recovered */
 950
 951 /*
 952  * Misc. filesystem flags
 953  */
 954 #define EXT2_FLAGS_SIGNED_HASH          0x0001  /* Signed dirhash in use */
 955 #define EXT2_FLAGS_UNSIGNED_HASH        0x0002  /* Unsigned dirhash in use */
 956 #define EXT2_FLAGS_TEST_FILESYS         0x0004  /* to test development code */
 957
 958 /*
 959  * Mount flags set via mount options or defaults
 960  */
 961 #define EXT4_MOUNT_GRPID                0x00004 /* Create files with directory's group */
 962 #define EXT4_MOUNT_DEBUG                0x00008 /* Some debugging messages */
 963 #define EXT4_MOUNT_ERRORS_CONT          0x00010 /* Continue on errors */
 964 #define EXT4_MOUNT_ERRORS_RO            0x00020 /* Remount fs ro on errors */
 965 #define EXT4_MOUNT_ERRORS_PANIC         0x00040 /* Panic on errors */
 966 #define EXT4_MOUNT_ERRORS_MASK          0x00070
 967 #define EXT4_MOUNT_MINIX_DF             0x00080 /* Mimics the Minix statfs */
 968 #define EXT4_MOUNT_NOLOAD               0x00100 /* Don't use existing journal*/
 969 #define EXT4_MOUNT_DATA_FLAGS           0x00C00 /* Mode for data writes: */
 970 #define EXT4_MOUNT_JOURNAL_DATA         0x00400 /* Write data to journal */
 971 #define EXT4_MOUNT_ORDERED_DATA         0x00800 /* Flush data before commit */
 972 #define EXT4_MOUNT_WRITEBACK_DATA       0x00C00 /* No data ordering */
 973 #define EXT4_MOUNT_UPDATE_JOURNAL       0x01000 /* Update the journal format */
 974 #define EXT4_MOUNT_NO_UID32             0x02000  /* Disable 32-bit UIDs */
 975 #define EXT4_MOUNT_XATTR_USER           0x04000 /* Extended user attributes */
 976 #define EXT4_MOUNT_POSIX_ACL            0x08000 /* POSIX Access Control Lists */
 977 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC     0x10000 /* No auto delalloc mapping */
 978 #define EXT4_MOUNT_BARRIER              0x20000 /* Use block barriers */
 979 #define EXT4_MOUNT_QUOTA                0x80000 /* Some quota option set */
 980 #define EXT4_MOUNT_USRQUOTA             0x100000 /* "old" user quota */
 981 #define EXT4_MOUNT_GRPQUOTA             0x200000 /* "old" group quota */
 982 #define EXT4_MOUNT_DIOREAD_NOLOCK       0x400000 /* Enable support for dio read nolocking */
 983 #define EXT4_MOUNT_JOURNAL_CHECKSUM     0x800000 /* Journal checksums */
 984 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT 0x1000000 /* Journal Async Commit */
 985 #define EXT4_MOUNT_DELALLOC             0x8000000 /* Delalloc support */
 986 #define EXT4_MOUNT_DATA_ERR_ABORT       0x10000000 /* Abort on file data write */
 987 #define EXT4_MOUNT_BLOCK_VALIDITY       0x20000000 /* Block validity checking */
 988 #define EXT4_MOUNT_DISCARD              0x40000000 /* Issue DISCARD requests */
 989 #define EXT4_MOUNT_INIT_INODE_TABLE     0x80000000 /* Initialize uninitialized itables */
 990
 991 /*
 992  * Mount flags set either automatically (could not be set by mount option)
 993  * based on per file system feature or property or in special cases such as
 994  * distinguishing between explicit mount option definition and default.
 995  */
 996 #define EXT4_MOUNT2_EXPLICIT_DELALLOC   0x00000001 /* User explicitly
 997                                                       specified delalloc */
 998 #define EXT4_MOUNT2_STD_GROUP_SIZE      0x00000002 /* We have standard group
 999                                                       size of blocksize * 8
1000                                                       blocks */
1001
1002 #define clear_opt(sb, opt)              EXT4_SB(sb)->s_mount_opt &= \
1003                                                 ~EXT4_MOUNT_##opt
1004 #define set_opt(sb, opt)                EXT4_SB(sb)->s_mount_opt |= \
1005                                                 EXT4_MOUNT_##opt
1006 #define test_opt(sb, opt)               (EXT4_SB(sb)->s_mount_opt & \
1007                                          EXT4_MOUNT_##opt)
1008
1009 #define clear_opt2(sb, opt)             EXT4_SB(sb)->s_mount_opt2 &= \
1010                                                 ~EXT4_MOUNT2_##opt
1011 #define set_opt2(sb, opt)               EXT4_SB(sb)->s_mount_opt2 |= \
1012                                                 EXT4_MOUNT2_##opt
1013 #define test_opt2(sb, opt)              (EXT4_SB(sb)->s_mount_opt2 & \
1014                                          EXT4_MOUNT2_##opt)
1015
1016 #define ext4_test_and_set_bit           __test_and_set_bit_le
1017 #define ext4_set_bit                    __set_bit_le
1018 #define ext4_set_bit_atomic             ext2_set_bit_atomic
1019 #define ext4_test_and_clear_bit         __test_and_clear_bit_le
1020 #define ext4_clear_bit                  __clear_bit_le
1021 #define ext4_clear_bit_atomic           ext2_clear_bit_atomic
1022 #define ext4_test_bit                   test_bit_le
1023 #define ext4_find_next_zero_bit         find_next_zero_bit_le
1024 #define ext4_find_next_bit              find_next_bit_le
1025
1026 extern void ext4_set_bits(void *bm, int cur, int len);
1027
1028 /*
1029  * Maximal mount counts between two filesystem checks
1030  */
1031 #define EXT4_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
1032 #define EXT4_DFL_CHECKINTERVAL          0       /* Don't use interval check */
1033
1034 /*
1035  * Behaviour when detecting errors
1036  */
1037 #define EXT4_ERRORS_CONTINUE            1       /* Continue execution */
1038 #define EXT4_ERRORS_RO                  2       /* Remount fs read-only */
1039 #define EXT4_ERRORS_PANIC               3       /* Panic */
1040 #define EXT4_ERRORS_DEFAULT             EXT4_ERRORS_CONTINUE
1041
1042 /* Metadata checksum algorithm codes */
1043 #define EXT4_CRC32C_CHKSUM              1
1044
1045 /*
1046  * Structure of the super block
1047  */
1048 struct ext4_super_block {
1049 /*00*/  __le32  s_inodes_count;         /* Inodes count */
1050         __le32  s_blocks_count_lo;      /* Blocks count */
1051         __le32  s_r_blocks_count_lo;    /* Reserved blocks count */
1052         __le32  s_free_blocks_count_lo; /* Free blocks count */
1053 /*10*/  __le32  s_free_inodes_count;    /* Free inodes count */
1054         __le32  s_first_data_block;     /* First Data Block */
1055         __le32  s_log_block_size;       /* Block size */
1056         __le32  s_log_cluster_size;     /* Allocation cluster size */
1057 /*20*/  __le32  s_blocks_per_group;     /* # Blocks per group */
1058         __le32  s_clusters_per_group;   /* # Clusters per group */
1059         __le32  s_inodes_per_group;     /* # Inodes per group */
1060         __le32  s_mtime;                /* Mount time */
1061 /*30*/  __le32  s_wtime;                /* Write time */
1062         __le16  s_mnt_count;            /* Mount count */
1063         __le16  s_max_mnt_count;        /* Maximal mount count */
1064         __le16  s_magic;                /* Magic signature */
1065         __le16  s_state;                /* File system state */
1066         __le16  s_errors;               /* Behaviour when detecting errors */
1067         __le16  s_minor_rev_level;      /* minor revision level */
1068 /*40*/  __le32  s_lastcheck;            /* time of last check */
1069         __le32  s_checkinterval;        /* max. time between checks */
1070         __le32  s_creator_os;           /* OS */
1071         __le32  s_rev_level;            /* Revision level */
1072 /*50*/  __le16  s_def_resuid;           /* Default uid for reserved blocks */
1073         __le16  s_def_resgid;           /* Default gid for reserved blocks */
1074         /*
1075          * These fields are for EXT4_DYNAMIC_REV superblocks only.
1076          *
1077          * Note: the difference between the compatible feature set and
1078          * the incompatible feature set is that if there is a bit set
1079          * in the incompatible feature set that the kernel doesn't
1080          * know about, it should refuse to mount the filesystem.
1081          *
1082          * e2fsck's requirements are more strict; if it doesn't know
1083          * about a feature in either the compatible or incompatible
1084          * feature set, it must abort and not try to meddle with
1085          * things it doesn't understand...
1086          */
1087         __le32  s_first_ino;            /* First non-reserved inode */
1088         __le16  s_inode_size;           /* size of inode structure */
1089         __le16  s_block_group_nr;       /* block group # of this superblock */
1090         __le32  s_feature_compat;       /* compatible feature set */
1091 /*60*/  __le32  s_feature_incompat;     /* incompatible feature set */
1092         __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
1093 /*68*/  __u8    s_uuid[16];             /* 128-bit uuid for volume */
1094 /*78*/  char    s_volume_name[16];      /* volume name */
1095 /*88*/  char    s_last_mounted[64];     /* directory where last mounted */
1096 /*C8*/  __le32  s_algorithm_usage_bitmap; /* For compression */
1097         /*
1098          * Performance hints.  Directory preallocation should only
1099          * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
1100          */
1101         __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
1102         __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
1103         __le16  s_reserved_gdt_blocks;  /* Per group desc for online growth */
1104         /*
1105          * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
1106          */
1107 /*D0*/  __u8    s_journal_uuid[16];     /* uuid of journal superblock */
1108 /*E0*/  __le32  s_journal_inum;         /* inode number of journal file */
1109         __le32  s_journal_dev;          /* device number of journal file */
1110         __le32  s_last_orphan;          /* start of list of inodes to delete */
1111         __le32  s_hash_seed[4];         /* HTREE hash seed */
1112         __u8    s_def_hash_version;     /* Default hash version to use */
1113         __u8    s_jnl_backup_type;
1114         __le16  s_desc_size;            /* size of group descriptor */
1115 /*100*/ __le32  s_default_mount_opts;
1116         __le32  s_first_meta_bg;        /* First metablock block group */
1117         __le32  s_mkfs_time;            /* When the filesystem was created */
1118         __le32  s_jnl_blocks[17];       /* Backup of the journal inode */
1119         /* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
1120 /*150*/ __le32  s_blocks_count_hi;      /* Blocks count */
1121         __le32  s_r_blocks_count_hi;    /* Reserved blocks count */
1122         __le32  s_free_blocks_count_hi; /* Free blocks count */
1123         __le16  s_min_extra_isize;      /* All inodes have at least # bytes */
1124         __le16  s_want_extra_isize;     /* New inodes should reserve # bytes */
1125         __le32  s_flags;                /* Miscellaneous flags */
1126         __le16  s_raid_stride;          /* RAID stride */
1127         __le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */
1128         __le64  s_mmp_block;            /* Block for multi-mount protection */
1129         __le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1130         __u8    s_log_groups_per_flex;  /* FLEX_BG group size */
1131         __u8    s_checksum_type;        /* metadata checksum algorithm used */
1132         __le16  s_reserved_pad;
1133         __le64  s_kbytes_written;       /* nr of lifetime kilobytes written */
1134         __le32  s_snapshot_inum;        /* Inode number of active snapshot */
1135         __le32  s_snapshot_id;          /* sequential ID of active snapshot */
1136         __le64  s_snapshot_r_blocks_count; /* reserved blocks for active
1137                                               snapshot's future use */
1138         __le32  s_snapshot_list;        /* inode number of the head of the
1139                                            on-disk snapshot list */
1140 #define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
1141         __le32  s_error_count;          /* number of fs errors */
1142         __le32  s_first_error_time;     /* first time an error happened */
1143         __le32  s_first_error_ino;      /* inode involved in first error */
1144         __le64  s_first_error_block;    /* block involved of first error */
1145         __u8    s_first_error_func[32]; /* function where the error happened */
1146         __le32  s_first_error_line;     /* line number where error happened */
1147         __le32  s_last_error_time;      /* most recent time of an error */
1148         __le32  s_last_error_ino;       /* inode involved in last error */
1149         __le32  s_last_error_line;      /* line number where error happened */
1150         __le64  s_last_error_block;     /* block involved of last error */
1151         __u8    s_last_error_func[32];  /* function where the error happened */
1152 #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
1153         __u8    s_mount_opts[64];
1154         __le32  s_usr_quota_inum;       /* inode for tracking user quota */
1155         __le32  s_grp_quota_inum;       /* inode for tracking group quota */
1156         __le32  s_overhead_clusters;    /* overhead blocks/clusters in fs */
1157         __le32  s_reserved[108];        /* Padding to the end of the block */
1158         __le32  s_checksum;             /* crc32c(superblock) */
1159 };
1160
1161 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1162
1163 #ifdef __KERNEL__
1164
1165 /*
1166  * run-time mount flags
1167  */
1168 #define EXT4_MF_MNTDIR_SAMPLED  0x0001
1169 #define EXT4_MF_FS_ABORTED      0x0002  /* Fatal error detected */
1170
1171 /*
1172  * fourth extended-fs super-block data in memory
1173  */
1174 struct ext4_sb_info {
1175         unsigned long s_desc_size;      /* Size of a group descriptor in bytes */
1176         unsigned long s_inodes_per_block;/* Number of inodes per block */
1177         unsigned long s_blocks_per_group;/* Number of blocks in a group */
1178         unsigned long s_clusters_per_group; /* Number of clusters in a group */
1179         unsigned long s_inodes_per_group;/* Number of inodes in a group */
1180         unsigned long s_itb_per_group;  /* Number of inode table blocks per group */
1181         unsigned long s_gdb_count;      /* Number of group descriptor blocks */
1182         unsigned long s_desc_per_block; /* Number of group descriptors per block */
1183         ext4_group_t s_groups_count;    /* Number of groups in the fs */
1184         ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1185         unsigned long s_overhead;  /* # of fs overhead clusters */
1186         unsigned int s_cluster_ratio;   /* Number of blocks per cluster */
1187         unsigned int s_cluster_bits;    /* log2 of s_cluster_ratio */
1188         loff_t s_bitmap_maxbytes;       /* max bytes for bitmap files */
1189         struct buffer_head * s_sbh;     /* Buffer containing the super block */
1190         struct ext4_super_block *s_es;  /* Pointer to the super block in the buffer */
1191         struct buffer_head **s_group_desc;
1192         unsigned int s_mount_opt;
1193         unsigned int s_mount_opt2;
1194         unsigned int s_mount_flags;
1195         unsigned int s_def_mount_opt;
1196         ext4_fsblk_t s_sb_block;
1197         atomic64_t s_resv_clusters;
1198         kuid_t s_resuid;
1199         kgid_t s_resgid;
1200         unsigned short s_mount_state;
1201         unsigned short s_pad;
1202         int s_addr_per_block_bits;
1203         int s_desc_per_block_bits;
1204         int s_inode_size;
1205         int s_first_ino;
1206         unsigned int s_inode_readahead_blks;
1207         unsigned int s_inode_goal;
1208         spinlock_t s_next_gen_lock;
1209         u32 s_next_generation;
1210         u32 s_hash_seed[4];
1211         int s_def_hash_version;
1212         int s_hash_unsigned;    /* 3 if hash should be signed, 0 if not */
1213         struct percpu_counter s_freeclusters_counter;
1214         struct percpu_counter s_freeinodes_counter;
1215         struct percpu_counter s_dirs_counter;
1216         struct percpu_counter s_dirtyclusters_counter;
1217         struct blockgroup_lock *s_blockgroup_lock;
1218         struct proc_dir_entry *s_proc;
1219         struct kobject s_kobj;
1220         struct completion s_kobj_unregister;
1221         struct super_block *s_sb;
1222
1223         /* Journaling */
1224         struct journal_s *s_journal;
1225         struct list_head s_orphan;
1226         struct mutex s_orphan_lock;
1227         unsigned long s_resize_flags;           /* Flags indicating if there
1228                                                    is a resizer */
1229         unsigned long s_commit_interval;
1230         u32 s_max_batch_time;
1231         u32 s_min_batch_time;
1232         struct block_device *journal_bdev;
1233 #ifdef CONFIG_QUOTA
1234         char *s_qf_names[MAXQUOTAS];            /* Names of quota files with journalled quota */
1235         int s_jquota_fmt;                       /* Format of quota to use */
1236 #endif
1237         unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1238         struct rb_root system_blks;
1239
1240 #ifdef EXTENTS_STATS
1241         /* ext4 extents stats */
1242         unsigned long s_ext_min;
1243         unsigned long s_ext_max;
1244         unsigned long s_depth_max;
1245         spinlock_t s_ext_stats_lock;
1246         unsigned long s_ext_blocks;
1247         unsigned long s_ext_extents;
1248 #endif
1249
1250         /* for buddy allocator */
1251         struct ext4_group_info ***s_group_info;
1252         struct inode *s_buddy_cache;
1253         spinlock_t s_md_lock;
1254         unsigned short *s_mb_offsets;
1255         unsigned int *s_mb_maxs;
1256         unsigned int s_group_info_size;
1257
1258         /* tunables */
1259         unsigned long s_stripe;
1260         unsigned int s_mb_stream_request;
1261         unsigned int s_mb_max_to_scan;
1262         unsigned int s_mb_min_to_scan;
1263         unsigned int s_mb_stats;
1264         unsigned int s_mb_order2_reqs;
1265         unsigned int s_mb_group_prealloc;
1266         unsigned int s_max_dir_size_kb;
1267         /* where last allocation was done - for stream allocation */
1268         unsigned long s_mb_last_group;
1269         unsigned long s_mb_last_start;
1270
1271         /* stats for buddy allocator */
1272         atomic_t s_bal_reqs;    /* number of reqs with len > 1 */
1273         atomic_t s_bal_success; /* we found long enough chunks */
1274         atomic_t s_bal_allocated;       /* in blocks */
1275         atomic_t s_bal_ex_scanned;      /* total extents scanned */
1276         atomic_t s_bal_goals;   /* goal hits */
1277         atomic_t s_bal_breaks;  /* too long searches */
1278         atomic_t s_bal_2orders; /* 2^order hits */
1279         spinlock_t s_bal_lock;
1280         unsigned long s_mb_buddies_generated;
1281         unsigned long long s_mb_generation_time;
1282         atomic_t s_mb_lost_chunks;
1283         atomic_t s_mb_preallocated;
1284         atomic_t s_mb_discarded;
1285         atomic_t s_lock_busy;
1286
1287         /* locality groups */
1288         struct ext4_locality_group __percpu *s_locality_groups;
1289
1290         /* for write statistics */
1291         unsigned long s_sectors_written_start;
1292         u64 s_kbytes_written;
1293
1294         /* the size of zero-out chunk */
1295         unsigned int s_extent_max_zeroout_kb;
1296
1297         unsigned int s_log_groups_per_flex;
1298         struct flex_groups *s_flex_groups;
1299         ext4_group_t s_flex_groups_allocated;
1300
1301         /* workqueue for reserved extent conversions (buffered io) */
1302         struct workqueue_struct *rsv_conversion_wq;
1303
1304         /* timer for periodic error stats printing */
1305         struct timer_list s_err_report;
1306
1307         /* Lazy inode table initialization info */
1308         struct ext4_li_request *s_li_request;
1309         /* Wait multiplier for lazy initialization thread */
1310         unsigned int s_li_wait_mult;
1311
1312         /* Kernel thread for multiple mount protection */
1313         struct task_struct *s_mmp_tsk;
1314
1315         /* record the last minlen when FITRIM is called. */
1316         atomic_t s_last_trim_minblks;
1317
1318         /* Reference to checksum algorithm driver via cryptoapi */
1319         struct crypto_shash *s_chksum_driver;
1320
1321         /* Precomputed FS UUID checksum for seeding other checksums */
1322         __u32 s_csum_seed;
1323
1324         /* Reclaim extents from extent status tree */
1325         struct shrinker s_es_shrinker;
1326         struct list_head s_es_lru;
1327         unsigned long s_es_last_sorted;
1328         struct percpu_counter s_extent_cache_cnt;
1329         spinlock_t s_es_lru_lock ____cacheline_aligned_in_smp;
1330
1331         /* Ratelimit ext4 messages. */
1332         struct ratelimit_state s_err_ratelimit_state;
1333         struct ratelimit_state s_warning_ratelimit_state;
1334         struct ratelimit_state s_msg_ratelimit_state;
1335 };
1336
1337 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1338 {
1339         return sb->s_fs_info;
1340 }
1341 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1342 {
1343         return container_of(inode, struct ext4_inode_info, vfs_inode);
1344 }
1345
1346 static inline struct timespec ext4_current_time(struct inode *inode)
1347 {
1348         return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1349                 current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1350 }
1351
1352 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1353 {
1354         return ino == EXT4_ROOT_INO ||
1355                 ino == EXT4_USR_QUOTA_INO ||
1356                 ino == EXT4_GRP_QUOTA_INO ||
1357                 ino == EXT4_BOOT_LOADER_INO ||
1358                 ino == EXT4_JOURNAL_INO ||
1359                 ino == EXT4_RESIZE_INO ||
1360                 (ino >= EXT4_FIRST_INO(sb) &&
1361                  ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1362 }
1363
1364 static inline void ext4_set_io_unwritten_flag(struct inode *inode,
1365                                               struct ext4_io_end *io_end)
1366 {
1367         if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
1368                 io_end->flag |= EXT4_IO_END_UNWRITTEN;
1369                 atomic_inc(&EXT4_I(inode)->i_unwritten);
1370         }
1371 }
1372
1373 static inline ext4_io_end_t *ext4_inode_aio(struct inode *inode)
1374 {
1375         return inode->i_private;
1376 }
1377
1378 static inline void ext4_inode_aio_set(struct inode *inode, ext4_io_end_t *io)
1379 {
1380         inode->i_private = io;
1381 }
1382
1383 /*
1384  * Inode dynamic state flags
1385  */
1386 enum {
1387         EXT4_STATE_JDATA,               /* journaled data exists */
1388         EXT4_STATE_NEW,                 /* inode is newly created */
1389         EXT4_STATE_XATTR,               /* has in-inode xattrs */
1390         EXT4_STATE_NO_EXPAND,           /* No space for expansion */
1391         EXT4_STATE_DA_ALLOC_CLOSE,      /* Alloc DA blks on close */
1392         EXT4_STATE_EXT_MIGRATE,         /* Inode is migrating */
1393         EXT4_STATE_DIO_UNWRITTEN,       /* need convert on dio done*/
1394         EXT4_STATE_NEWENTRY,            /* File just added to dir */
1395         EXT4_STATE_DELALLOC_RESERVED,   /* blks already reserved for delalloc */
1396         EXT4_STATE_DIOREAD_LOCK,        /* Disable support for dio read
1397                                            nolocking */
1398         EXT4_STATE_MAY_INLINE_DATA,     /* may have in-inode data */
1399         EXT4_STATE_ORDERED_MODE,        /* data=ordered mode */
1400         EXT4_STATE_EXT_PRECACHED,       /* extents have been precached */
1401 };
1402
1403 #define EXT4_INODE_BIT_FNS(name, field, offset)                         \
1404 static inline int ext4_test_inode_##name(struct inode *inode, int bit)  \
1405 {                                                                       \
1406         return test_bit(bit + (offset), &EXT4_I(inode)->i_##field);     \
1407 }                                                                       \
1408 static inline void ext4_set_inode_##name(struct inode *inode, int bit)  \
1409 {                                                                       \
1410         set_bit(bit + (offset), &EXT4_I(inode)->i_##field);             \
1411 }                                                                       \
1412 static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1413 {                                                                       \
1414         clear_bit(bit + (offset), &EXT4_I(inode)->i_##field);           \
1415 }
1416
1417 /* Add these declarations here only so that these functions can be
1418  * found by name.  Otherwise, they are very hard to locate. */
1419 static inline int ext4_test_inode_flag(struct inode *inode, int bit);
1420 static inline void ext4_set_inode_flag(struct inode *inode, int bit);
1421 static inline void ext4_clear_inode_flag(struct inode *inode, int bit);
1422 EXT4_INODE_BIT_FNS(flag, flags, 0)
1423
1424 /* Add these declarations here only so that these functions can be
1425  * found by name.  Otherwise, they are very hard to locate. */
1426 static inline int ext4_test_inode_state(struct inode *inode, int bit);
1427 static inline void ext4_set_inode_state(struct inode *inode, int bit);
1428 static inline void ext4_clear_inode_state(struct inode *inode, int bit);
1429 #if (BITS_PER_LONG < 64)
1430 EXT4_INODE_BIT_FNS(state, state_flags, 0)
1431
1432 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1433 {
1434         (ei)->i_state_flags = 0;
1435 }
1436 #else
1437 EXT4_INODE_BIT_FNS(state, flags, 32)
1438
1439 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1440 {
1441         /* We depend on the fact that callers will set i_flags */
1442 }
1443 #endif
1444 #else
1445 /* Assume that user mode programs are passing in an ext4fs superblock, not
1446  * a kernel struct super_block.  This will allow us to call the feature-test
1447  * macros from user land. */
1448 #define EXT4_SB(sb)     (sb)
1449 #endif
1450
1451 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1452
1453 /*
1454  * Codes for operating systems
1455  */
1456 #define EXT4_OS_LINUX           0
1457 #define EXT4_OS_HURD            1
1458 #define EXT4_OS_MASIX           2
1459 #define EXT4_OS_FREEBSD         3
1460 #define EXT4_OS_LITES           4
1461
1462 /*
1463  * Revision levels
1464  */
1465 #define EXT4_GOOD_OLD_REV       0       /* The good old (original) format */
1466 #define EXT4_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
1467
1468 #define EXT4_CURRENT_REV        EXT4_GOOD_OLD_REV
1469 #define EXT4_MAX_SUPP_REV       EXT4_DYNAMIC_REV
1470
1471 #define EXT4_GOOD_OLD_INODE_SIZE 128
1472
1473 /*
1474  * Feature set definitions
1475  */
1476
1477 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)                        \
1478         ((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1479 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
1480         ((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1481 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)                      \
1482         ((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1483 #define EXT4_SET_COMPAT_FEATURE(sb,mask)                        \
1484         EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1485 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)                     \
1486         EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1487 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)                      \
1488         EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1489 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)                      \
1490         EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1491 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
1492         EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1493 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
1494         EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1495
1496 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC        0x0001
1497 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES       0x0002
1498 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL         0x0004
1499 #define EXT4_FEATURE_COMPAT_EXT_ATTR            0x0008
1500 #define EXT4_FEATURE_COMPAT_RESIZE_INODE        0x0010
1501 #define EXT4_FEATURE_COMPAT_DIR_INDEX           0x0020
1502
1503 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
1504 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
1505 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
1506 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1507 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM         0x0010
1508 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK        0x0020
1509 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE      0x0040
1510 #define EXT4_FEATURE_RO_COMPAT_QUOTA            0x0100
1511 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC         0x0200
1512 /*
1513  * METADATA_CSUM also enables group descriptor checksums (GDT_CSUM).  When
1514  * METADATA_CSUM is set, group descriptor checksums use the same algorithm as
1515  * all other data structures' checksums.  However, the METADATA_CSUM and
1516  * GDT_CSUM bits are mutually exclusive.
1517  */
1518 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM    0x0400
1519
1520 #define EXT4_FEATURE_INCOMPAT_COMPRESSION       0x0001
1521 #define EXT4_FEATURE_INCOMPAT_FILETYPE          0x0002
1522 #define EXT4_FEATURE_INCOMPAT_RECOVER           0x0004 /* Needs recovery */
1523 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008 /* Journal device */
1524 #define EXT4_FEATURE_INCOMPAT_META_BG           0x0010
1525 #define EXT4_FEATURE_INCOMPAT_EXTENTS           0x0040 /* extents support */
1526 #define EXT4_FEATURE_INCOMPAT_64BIT             0x0080
1527 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1528 #define EXT4_FEATURE_INCOMPAT_FLEX_BG           0x0200
1529 #define EXT4_FEATURE_INCOMPAT_EA_INODE          0x0400 /* EA in inode */
1530 #define EXT4_FEATURE_INCOMPAT_DIRDATA           0x1000 /* data in dirent */
1531 #define EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM  0x2000 /* use crc32c for bg */
1532 #define EXT4_FEATURE_INCOMPAT_LARGEDIR          0x4000 /* >2GB or 3-lvl htree */
1533 #define EXT4_FEATURE_INCOMPAT_INLINE_DATA       0x8000 /* data in inode */
1534
1535 #define EXT2_FEATURE_COMPAT_SUPP        EXT4_FEATURE_COMPAT_EXT_ATTR
1536 #define EXT2_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1537                                          EXT4_FEATURE_INCOMPAT_META_BG)
1538 #define EXT2_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1539                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1540                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1541
1542 #define EXT3_FEATURE_COMPAT_SUPP        EXT4_FEATURE_COMPAT_EXT_ATTR
1543 #define EXT3_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1544                                          EXT4_FEATURE_INCOMPAT_RECOVER| \
1545                                          EXT4_FEATURE_INCOMPAT_META_BG)
1546 #define EXT3_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1547                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1548                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1549
1550 #define EXT4_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
1551 #define EXT4_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1552                                          EXT4_FEATURE_INCOMPAT_RECOVER| \
1553                                          EXT4_FEATURE_INCOMPAT_META_BG| \
1554                                          EXT4_FEATURE_INCOMPAT_EXTENTS| \
1555                                          EXT4_FEATURE_INCOMPAT_64BIT| \
1556                                          EXT4_FEATURE_INCOMPAT_FLEX_BG| \
1557                                          EXT4_FEATURE_INCOMPAT_MMP |    \
1558                                          EXT4_FEATURE_INCOMPAT_INLINE_DATA)
1559 #define EXT4_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1560                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1561                                          EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1562                                          EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1563                                          EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1564                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1565                                          EXT4_FEATURE_RO_COMPAT_HUGE_FILE |\
1566                                          EXT4_FEATURE_RO_COMPAT_BIGALLOC |\
1567                                          EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
1568                                          EXT4_FEATURE_RO_COMPAT_QUOTA)
1569
1570 /*
1571  * Default values for user and/or group using reserved blocks
1572  */
1573 #define EXT4_DEF_RESUID         0
1574 #define EXT4_DEF_RESGID         0
1575
1576 #define EXT4_DEF_INODE_READAHEAD_BLKS   32
1577
1578 /*
1579  * Default mount options
1580  */
1581 #define EXT4_DEFM_DEBUG         0x0001
1582 #define EXT4_DEFM_BSDGROUPS     0x0002
1583 #define EXT4_DEFM_XATTR_USER    0x0004
1584 #define EXT4_DEFM_ACL           0x0008
1585 #define EXT4_DEFM_UID16         0x0010
1586 #define EXT4_DEFM_JMODE         0x0060
1587 #define EXT4_DEFM_JMODE_DATA    0x0020
1588 #define EXT4_DEFM_JMODE_ORDERED 0x0040
1589 #define EXT4_DEFM_JMODE_WBACK   0x0060
1590 #define EXT4_DEFM_NOBARRIER     0x0100
1591 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
1592 #define EXT4_DEFM_DISCARD       0x0400
1593 #define EXT4_DEFM_NODELALLOC    0x0800
1594
1595 /*
1596  * Default journal batch times
1597  */
1598 #define EXT4_DEF_MIN_BATCH_TIME 0
1599 #define EXT4_DEF_MAX_BATCH_TIME 15000 /* 15ms */
1600
1601 /*
1602  * Minimum number of groups in a flexgroup before we separate out
1603  * directories into the first block group of a flexgroup
1604  */
1605 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME 4
1606
1607 /*
1608  * Structure of a directory entry
1609  */
1610 #define EXT4_NAME_LEN 255
1611
1612 struct ext4_dir_entry {
1613         __le32  inode;                  /* Inode number */
1614         __le16  rec_len;                /* Directory entry length */
1615         __le16  name_len;               /* Name length */
1616         char    name[EXT4_NAME_LEN];    /* File name */
1617 };
1618
1619 /*
1620  * The new version of the directory entry.  Since EXT4 structures are
1621  * stored in intel byte order, and the name_len field could never be
1622  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1623  * file_type field.
1624  */
1625 struct ext4_dir_entry_2 {
1626         __le32  inode;                  /* Inode number */
1627         __le16  rec_len;                /* Directory entry length */
1628         __u8    name_len;               /* Name length */
1629         __u8    file_type;
1630         char    name[EXT4_NAME_LEN];    /* File name */
1631 };
1632
1633 /*
1634  * This is a bogus directory entry at the end of each leaf block that
1635  * records checksums.
1636  */
1637 struct ext4_dir_entry_tail {
1638         __le32  det_reserved_zero1;     /* Pretend to be unused */
1639         __le16  det_rec_len;            /* 12 */
1640         __u8    det_reserved_zero2;     /* Zero name length */
1641         __u8    det_reserved_ft;        /* 0xDE, fake file type */
1642         __le32  det_checksum;           /* crc32c(uuid+inum+dirblock) */
1643 };
1644
1645 #define EXT4_DIRENT_TAIL(block, blocksize) \
1646         ((struct ext4_dir_entry_tail *)(((void *)(block)) + \
1647                                         ((blocksize) - \
1648                                          sizeof(struct ext4_dir_entry_tail))))
1649
1650 /*
1651  * Ext4 directory file types.  Only the low 3 bits are used.  The
1652  * other bits are reserved for now.
1653  */
1654 #define EXT4_FT_UNKNOWN         0
1655 #define EXT4_FT_REG_FILE        1
1656 #define EXT4_FT_DIR             2
1657 #define EXT4_FT_CHRDEV          3
1658 #define EXT4_FT_BLKDEV          4
1659 #define EXT4_FT_FIFO            5
1660 #define EXT4_FT_SOCK            6
1661 #define EXT4_FT_SYMLINK         7
1662
1663 #define EXT4_FT_MAX             8
1664
1665 #define EXT4_FT_DIR_CSUM        0xDE
1666
1667 /*
1668  * EXT4_DIR_PAD defines the directory entries boundaries
1669  *
1670  * NOTE: It must be a multiple of 4
1671  */
1672 #define EXT4_DIR_PAD                    4
1673 #define EXT4_DIR_ROUND                  (EXT4_DIR_PAD - 1)
1674 #define EXT4_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT4_DIR_ROUND) & \
1675                                          ~EXT4_DIR_ROUND)
1676 #define EXT4_MAX_REC_LEN                ((1<<16)-1)
1677
1678 /*
1679  * If we ever get support for fs block sizes > page_size, we'll need
1680  * to remove the #if statements in the next two functions...
1681  */
1682 static inline unsigned int
1683 ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
1684 {
1685         unsigned len = le16_to_cpu(dlen);
1686
1687 #if (PAGE_CACHE_SIZE >= 65536)
1688         if (len == EXT4_MAX_REC_LEN || len == 0)
1689                 return blocksize;
1690         return (len & 65532) | ((len & 3) << 16);
1691 #else
1692         return len;
1693 #endif
1694 }
1695
1696 static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
1697 {
1698         if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
1699                 BUG();
1700 #if (PAGE_CACHE_SIZE >= 65536)
1701         if (len < 65536)
1702                 return cpu_to_le16(len);
1703         if (len == blocksize) {
1704                 if (blocksize == 65536)
1705                         return cpu_to_le16(EXT4_MAX_REC_LEN);
1706                 else
1707                         return cpu_to_le16(0);
1708         }
1709         return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
1710 #else
1711         return cpu_to_le16(len);
1712 #endif
1713 }
1714
1715 /*
1716  * Hash Tree Directory indexing
1717  * (c) Daniel Phillips, 2001
1718  */
1719
1720 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1721                                       EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1722                     ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
1723 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1724 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1725
1726 /* Legal values for the dx_root hash_version field: */
1727
1728 #define DX_HASH_LEGACY          0
1729 #define DX_HASH_HALF_MD4        1
1730 #define DX_HASH_TEA             2
1731 #define DX_HASH_LEGACY_UNSIGNED 3
1732 #define DX_HASH_HALF_MD4_UNSIGNED       4
1733 #define DX_HASH_TEA_UNSIGNED            5
1734
1735 static inline u32 ext4_chksum(struct ext4_sb_info *sbi, u32 crc,
1736                               const void *address, unsigned int length)
1737 {
1738         struct {
1739                 struct shash_desc shash;
1740                 char ctx[4];
1741         } desc;
1742         int err;
1743
1744         BUG_ON(crypto_shash_descsize(sbi->s_chksum_driver)!=sizeof(desc.ctx));
1745
1746         desc.shash.tfm = sbi->s_chksum_driver;
1747         desc.shash.flags = 0;
1748         *(u32 *)desc.ctx = crc;
1749
1750         err = crypto_shash_update(&desc.shash, address, length);
1751         BUG_ON(err);
1752
1753         return *(u32 *)desc.ctx;
1754 }
1755
1756 #ifdef __KERNEL__
1757
1758 /* hash info structure used by the directory hash */
1759 struct dx_hash_info
1760 {
1761         u32             hash;
1762         u32             minor_hash;
1763         int             hash_version;
1764         u32             *seed;
1765 };
1766
1767
1768 /* 32 and 64 bit signed EOF for dx directories */
1769 #define EXT4_HTREE_EOF_32BIT   ((1UL  << (32 - 1)) - 1)
1770 #define EXT4_HTREE_EOF_64BIT   ((1ULL << (64 - 1)) - 1)
1771
1772
1773 /*
1774  * Control parameters used by ext4_htree_next_block
1775  */
1776 #define HASH_NB_ALWAYS          1
1777
1778
1779 /*
1780  * Describe an inode's exact location on disk and in memory
1781  */
1782 struct ext4_iloc
1783 {
1784         struct buffer_head *bh;
1785         unsigned long offset;
1786         ext4_group_t block_group;
1787 };
1788
1789 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1790 {
1791         return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1792 }
1793
1794 /*
1795  * This structure is stuffed into the struct file's private_data field
1796  * for directories.  It is where we put information so that we can do
1797  * readdir operations in hash tree order.
1798  */
1799 struct dir_private_info {
1800         struct rb_root  root;
1801         struct rb_node  *curr_node;
1802         struct fname    *extra_fname;
1803         loff_t          last_pos;
1804         __u32           curr_hash;
1805         __u32           curr_minor_hash;
1806         __u32           next_hash;
1807 };
1808
1809 /* calculate the first block number of the group */
1810 static inline ext4_fsblk_t
1811 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1812 {
1813         return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1814                 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1815 }
1816
1817 /*
1818  * Special error return code only used by dx_probe() and its callers.
1819  */
1820 #define ERR_BAD_DX_DIR  -75000
1821
1822 /*
1823  * Timeout and state flag for lazy initialization inode thread.
1824  */
1825 #define EXT4_DEF_LI_WAIT_MULT                   10
1826 #define EXT4_DEF_LI_MAX_START_DELAY             5
1827 #define EXT4_LAZYINIT_QUIT                      0x0001
1828 #define EXT4_LAZYINIT_RUNNING                   0x0002
1829
1830 /*
1831  * Lazy inode table initialization info
1832  */
1833 struct ext4_lazy_init {
1834         unsigned long           li_state;
1835         struct list_head        li_request_list;
1836         struct mutex            li_list_mtx;
1837 };
1838
1839 struct ext4_li_request {
1840         struct super_block      *lr_super;
1841         struct ext4_sb_info     *lr_sbi;
1842         ext4_group_t            lr_next_group;
1843         struct list_head        lr_request;
1844         unsigned long           lr_next_sched;
1845         unsigned long           lr_timeout;
1846 };
1847
1848 struct ext4_features {
1849         struct kobject f_kobj;
1850         struct completion f_kobj_unregister;
1851 };
1852
1853 /*
1854  * This structure will be used for multiple mount protection. It will be
1855  * written into the block number saved in the s_mmp_block field in the
1856  * superblock. Programs that check MMP should assume that if
1857  * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
1858  * to use the filesystem, regardless of how old the timestamp is.
1859  */
1860 #define EXT4_MMP_MAGIC     0x004D4D50U /* ASCII for MMP */
1861 #define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
1862 #define EXT4_MMP_SEQ_FSCK  0xE24D4D50U /* mmp_seq value when being fscked */
1863 #define EXT4_MMP_SEQ_MAX   0xE24D4D4FU /* maximum valid mmp_seq value */
1864
1865 struct mmp_struct {
1866         __le32  mmp_magic;              /* Magic number for MMP */
1867         __le32  mmp_seq;                /* Sequence no. updated periodically */
1868
1869         /*
1870          * mmp_time, mmp_nodename & mmp_bdevname are only used for information
1871          * purposes and do not affect the correctness of the algorithm
1872          */
1873         __le64  mmp_time;               /* Time last updated */
1874         char    mmp_nodename[64];       /* Node which last updated MMP block */
1875         char    mmp_bdevname[32];       /* Bdev which last updated MMP block */
1876
1877         /*
1878          * mmp_check_interval is used to verify if the MMP block has been
1879          * updated on the block device. The value is updated based on the
1880          * maximum time to write the MMP block during an update cycle.
1881          */
1882         __le16  mmp_check_interval;
1883
1884         __le16  mmp_pad1;
1885         __le32  mmp_pad2[226];
1886         __le32  mmp_checksum;           /* crc32c(uuid+mmp_block) */
1887 };
1888
1889 /* arguments passed to the mmp thread */
1890 struct mmpd_data {
1891         struct buffer_head *bh; /* bh from initial read_mmp_block() */
1892         struct super_block *sb;  /* super block of the fs */
1893 };
1894
1895 /*
1896  * Check interval multiplier
1897  * The MMP block is written every update interval and initially checked every
1898  * update interval x the multiplier (the value is then adapted based on the
1899  * write latency). The reason is that writes can be delayed under load and we
1900  * don't want readers to incorrectly assume that the filesystem is no longer
1901  * in use.
1902  */
1903 #define EXT4_MMP_CHECK_MULT             2UL
1904
1905 /*
1906  * Minimum interval for MMP checking in seconds.
1907  */
1908 #define EXT4_MMP_MIN_CHECK_INTERVAL     5UL
1909
1910 /*
1911  * Maximum interval for MMP checking in seconds.
1912  */
1913 #define EXT4_MMP_MAX_CHECK_INTERVAL     300UL
1914
1915 /*
1916  * Function prototypes
1917  */
1918
1919 /*
1920  * Ok, these declarations are also in <linux/kernel.h> but none of the
1921  * ext4 source programs needs to include it so they are duplicated here.
1922  */
1923 # define NORET_TYPE     /**/
1924 # define ATTRIB_NORET   __attribute__((noreturn))
1925 # define NORET_AND      noreturn,
1926
1927 /* bitmap.c */
1928 extern unsigned int ext4_count_free(char *bitmap, unsigned numchars);
1929 void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1930                                 struct ext4_group_desc *gdp,
1931                                 struct buffer_head *bh, int sz);
1932 int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1933                                   struct ext4_group_desc *gdp,
1934                                   struct buffer_head *bh, int sz);
1935 void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1936                                 struct ext4_group_desc *gdp,
1937                                 struct buffer_head *bh);
1938 int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1939                                   struct ext4_group_desc *gdp,
1940                                   struct buffer_head *bh);
1941
1942 /* balloc.c */
1943 extern void ext4_get_group_no_and_offset(struct super_block *sb,
1944                                          ext4_fsblk_t blocknr,
1945                                          ext4_group_t *blockgrpp,
1946                                          ext4_grpblk_t *offsetp);
1947 extern ext4_group_t ext4_get_group_number(struct super_block *sb,
1948                                           ext4_fsblk_t block);
1949
1950 extern void ext4_validate_block_bitmap(struct super_block *sb,
1951                                        struct ext4_group_desc *desc,
1952                                        ext4_group_t block_group,
1953                                        struct buffer_head *bh);
1954 extern unsigned int ext4_block_group(struct super_block *sb,
1955                         ext4_fsblk_t blocknr);
1956 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1957                         ext4_fsblk_t blocknr);
1958 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1959 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1960                         ext4_group_t group);
1961 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1962                                          ext4_fsblk_t goal,
1963                                          unsigned int flags,
1964                                          unsigned long *count,
1965                                          int *errp);
1966 extern int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
1967                                     s64 nclusters, unsigned int flags);
1968 extern ext4_fsblk_t ext4_count_free_clusters(struct super_block *);
1969 extern void ext4_check_blocks_bitmap(struct super_block *);
1970 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1971                                                     ext4_group_t block_group,
1972                                                     struct buffer_head ** bh);
1973 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1974
1975 extern struct buffer_head *ext4_read_block_bitmap_nowait(struct super_block *sb,
1976                                                 ext4_group_t block_group);
1977 extern int ext4_wait_block_bitmap(struct super_block *sb,
1978                                   ext4_group_t block_group,
1979                                   struct buffer_head *bh);
1980 extern struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1981                                                   ext4_group_t block_group);
1982 extern void ext4_init_block_bitmap(struct super_block *sb,
1983                                    struct buffer_head *bh,
1984                                    ext4_group_t group,
1985                                    struct ext4_group_desc *desc);
1986 extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
1987                                               ext4_group_t block_group,
1988                                               struct ext4_group_desc *gdp);
1989 extern unsigned ext4_num_overhead_clusters(struct super_block *sb,
1990                                            ext4_group_t block_group,
1991                                            struct ext4_group_desc *gdp);
1992 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
1993
1994 /* dir.c */
1995 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
1996                                   struct file *,
1997                                   struct ext4_dir_entry_2 *,
1998                                   struct buffer_head *, char *, int,
1999                                   unsigned int);
2000 #define ext4_check_dir_entry(dir, filp, de, bh, buf, size, offset)      \
2001         unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
2002                                         (de), (bh), (buf), (size), (offset)))
2003 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
2004                                     __u32 minor_hash,
2005                                     struct ext4_dir_entry_2 *dirent);
2006 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
2007 extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
2008                              struct buffer_head *bh,
2009                              void *buf, int buf_size,
2010                              const char *name, int namelen,
2011                              struct ext4_dir_entry_2 **dest_de);
2012 void ext4_insert_dentry(struct inode *inode,
2013                         struct ext4_dir_entry_2 *de,
2014                         int buf_size,
2015                         const char *name, int namelen);
2016 static inline void ext4_update_dx_flag(struct inode *inode)
2017 {
2018         if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
2019                                      EXT4_FEATURE_COMPAT_DIR_INDEX))
2020                 ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
2021 }
2022 static unsigned char ext4_filetype_table[] = {
2023         DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
2024 };
2025
2026 static inline  unsigned char get_dtype(struct super_block *sb, int filetype)
2027 {
2028         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE) ||
2029             (filetype >= EXT4_FT_MAX))
2030                 return DT_UNKNOWN;
2031
2032         return ext4_filetype_table[filetype];
2033 }
2034
2035 /* fsync.c */
2036 extern int ext4_sync_file(struct file *, loff_t, loff_t, int);
2037
2038 /* hash.c */
2039 extern int ext4fs_dirhash(const char *name, int len, struct
2040                           dx_hash_info *hinfo);
2041
2042 /* ialloc.c */
2043 extern struct inode *__ext4_new_inode(handle_t *, struct inode *, umode_t,
2044                                       const struct qstr *qstr, __u32 goal,
2045                                       uid_t *owner, int handle_type,
2046                                       unsigned int line_no, int nblocks);
2047
2048 #define ext4_new_inode(handle, dir, mode, qstr, goal, owner) \
2049         __ext4_new_inode((handle), (dir), (mode), (qstr), (goal), (owner), \
2050                          0, 0, 0)
2051 #define ext4_new_inode_start_handle(dir, mode, qstr, goal, owner, \
2052                                     type, nblocks)                  \
2053         __ext4_new_inode(NULL, (dir), (mode), (qstr), (goal), (owner), \
2054                          (type), __LINE__, (nblocks))
2055
2056
2057 extern void ext4_free_inode(handle_t *, struct inode *);
2058 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
2059 extern unsigned long ext4_count_free_inodes(struct super_block *);
2060 extern unsigned long ext4_count_dirs(struct super_block *);
2061 extern void ext4_check_inodes_bitmap(struct super_block *);
2062 extern void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
2063 extern int ext4_init_inode_table(struct super_block *sb,
2064                                  ext4_group_t group, int barrier);
2065 extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
2066
2067 /* mballoc.c */
2068 extern long ext4_mb_stats;
2069 extern long ext4_mb_max_to_scan;
2070 extern int ext4_mb_init(struct super_block *);
2071 extern int ext4_mb_release(struct super_block *);
2072 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
2073                                 struct ext4_allocation_request *, int *);
2074 extern int ext4_mb_reserve_blocks(struct super_block *, int);
2075 extern void ext4_discard_preallocations(struct inode *);
2076 extern int __init ext4_init_mballoc(void);
2077 extern void ext4_exit_mballoc(void);
2078 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
2079                              struct buffer_head *bh, ext4_fsblk_t block,
2080                              unsigned long count, int flags);
2081 extern int ext4_mb_alloc_groupinfo(struct super_block *sb,
2082                                    ext4_group_t ngroups);
2083 extern int ext4_mb_add_groupinfo(struct super_block *sb,
2084                 ext4_group_t i, struct ext4_group_desc *desc);
2085 extern int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
2086                                 ext4_fsblk_t block, unsigned long count);
2087 extern int ext4_trim_fs(struct super_block *, struct fstrim_range *);
2088
2089 /* inode.c */
2090 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
2091                                                 ext4_lblk_t, int, int *);
2092 struct buffer_head *ext4_bread(handle_t *, struct inode *,
2093                                                 ext4_lblk_t, int, int *);
2094 int ext4_get_block_write(struct inode *inode, sector_t iblock,
2095                          struct buffer_head *bh_result, int create);
2096 int ext4_get_block(struct inode *inode, sector_t iblock,
2097                                 struct buffer_head *bh_result, int create);
2098 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
2099                            struct buffer_head *bh, int create);
2100 int ext4_walk_page_buffers(handle_t *handle,
2101                            struct buffer_head *head,
2102                            unsigned from,
2103                            unsigned to,
2104                            int *partial,
2105                            int (*fn)(handle_t *handle,
2106                                      struct buffer_head *bh));
2107 int do_journal_get_write_access(handle_t *handle,
2108                                 struct buffer_head *bh);
2109 #define FALL_BACK_TO_NONDELALLOC 1
2110 #define CONVERT_INLINE_DATA      2
2111
2112 extern struct inode *ext4_iget(struct super_block *, unsigned long);
2113 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
2114 extern int  ext4_setattr(struct dentry *, struct iattr *);
2115 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
2116                                 struct kstat *stat);
2117 extern void ext4_evict_inode(struct inode *);
2118 extern void ext4_clear_inode(struct inode *);
2119 extern int  ext4_sync_inode(handle_t *, struct inode *);
2120 extern void ext4_dirty_inode(struct inode *, int);
2121 extern int ext4_change_inode_journal_flag(struct inode *, int);
2122 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
2123 extern int ext4_inode_attach_jinode(struct inode *inode);
2124 extern int ext4_can_truncate(struct inode *inode);
2125 extern void ext4_truncate(struct inode *);
2126 extern int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length);
2127 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
2128 extern void ext4_set_inode_flags(struct inode *);
2129 extern void ext4_get_inode_flags(struct ext4_inode_info *);
2130 extern int ext4_alloc_da_blocks(struct inode *inode);
2131 extern void ext4_set_aops(struct inode *inode);
2132 extern int ext4_writepage_trans_blocks(struct inode *);
2133 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
2134 extern int ext4_block_truncate_page(handle_t *handle,
2135                 struct address_space *mapping, loff_t from);
2136 extern int ext4_block_zero_page_range(handle_t *handle,
2137                 struct address_space *mapping, loff_t from, loff_t length);
2138 extern int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
2139                              loff_t lstart, loff_t lend);
2140 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
2141 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
2142 extern void ext4_da_update_reserve_space(struct inode *inode,
2143                                         int used, int quota_claim);
2144
2145 /* indirect.c */
2146 extern int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
2147                                 struct ext4_map_blocks *map, int flags);
2148 extern ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb,
2149                                 const struct iovec *iov, loff_t offset,
2150                                 unsigned long nr_segs);
2151 extern int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock);
2152 extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks);
2153 extern void ext4_ind_truncate(handle_t *, struct inode *inode);
2154 extern int ext4_free_hole_blocks(handle_t *handle, struct inode *inode,
2155                                  ext4_lblk_t first, ext4_lblk_t stop);
2156
2157 /* ioctl.c */
2158 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
2159 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
2160
2161 /* migrate.c */
2162 extern int ext4_ext_migrate(struct inode *);
2163 extern int ext4_ind_migrate(struct inode *inode);
2164
2165 /* namei.c */
2166 extern int ext4_dirent_csum_verify(struct inode *inode,
2167                                    struct ext4_dir_entry *dirent);
2168 extern int ext4_orphan_add(handle_t *, struct inode *);
2169 extern int ext4_orphan_del(handle_t *, struct inode *);
2170 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
2171                                 __u32 start_minor_hash, __u32 *next_hash);
2172 extern int search_dir(struct buffer_head *bh,
2173                       char *search_buf,
2174                       int buf_size,
2175                       struct inode *dir,
2176                       const struct qstr *d_name,
2177                       unsigned int offset,
2178                       struct ext4_dir_entry_2 **res_dir);
2179 extern int ext4_generic_delete_entry(handle_t *handle,
2180                                      struct inode *dir,
2181                                      struct ext4_dir_entry_2 *de_del,
2182                                      struct buffer_head *bh,
2183                                      void *entry_buf,
2184                                      int buf_size,
2185                                      int csum_size);
2186
2187 /* resize.c */
2188 extern int ext4_group_add(struct super_block *sb,
2189                                 struct ext4_new_group_data *input);
2190 extern int ext4_group_extend(struct super_block *sb,
2191                                 struct ext4_super_block *es,
2192                                 ext4_fsblk_t n_blocks_count);
2193 extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
2194
2195 /* super.c */
2196 extern int ext4_calculate_overhead(struct super_block *sb);
2197 extern int ext4_superblock_csum_verify(struct super_block *sb,
2198                                        struct ext4_super_block *es);
2199 extern void ext4_superblock_csum_set(struct super_block *sb);
2200 extern void *ext4_kvmalloc(size_t size, gfp_t flags);
2201 extern void *ext4_kvzalloc(size_t size, gfp_t flags);
2202 extern void ext4_kvfree(void *ptr);
2203 extern int ext4_alloc_flex_bg_array(struct super_block *sb,
2204                                     ext4_group_t ngroup);
2205 extern const char *ext4_decode_error(struct super_block *sb, int errno,
2206                                      char nbuf[16]);
2207
2208 extern __printf(4, 5)
2209 void __ext4_error(struct super_block *, const char *, unsigned int,
2210                   const char *, ...);
2211 extern __printf(5, 6)
2212 void __ext4_error_inode(struct inode *, const char *, unsigned int, ext4_fsblk_t,
2213                       const char *, ...);
2214 extern __printf(5, 6)
2215 void __ext4_error_file(struct file *, const char *, unsigned int, ext4_fsblk_t,
2216                      const char *, ...);
2217 extern void __ext4_std_error(struct super_block *, const char *,
2218                              unsigned int, int);
2219 extern __printf(4, 5)
2220 void __ext4_abort(struct super_block *, const char *, unsigned int,
2221                   const char *, ...);
2222 extern __printf(4, 5)
2223 void __ext4_warning(struct super_block *, const char *, unsigned int,
2224                     const char *, ...);
2225 extern __printf(3, 4)
2226 void __ext4_msg(struct super_block *, const char *, const char *, ...);
2227 extern void __dump_mmp_msg(struct super_block *, struct mmp_struct *mmp,
2228                            const char *, unsigned int, const char *);
2229 extern __printf(7, 8)
2230 void __ext4_grp_locked_error(const char *, unsigned int,
2231                              struct super_block *, ext4_group_t,
2232                              unsigned long, ext4_fsblk_t,
2233                              const char *, ...);
2234
2235 #ifdef CONFIG_PRINTK
2236
2237 #define ext4_error_inode(inode, func, line, block, fmt, ...)            \
2238         __ext4_error_inode(inode, func, line, block, fmt, ##__VA_ARGS__)
2239 #define ext4_error_file(file, func, line, block, fmt, ...)              \
2240         __ext4_error_file(file, func, line, block, fmt, ##__VA_ARGS__)
2241 #define ext4_error(sb, fmt, ...)                                        \
2242         __ext4_error(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2243 #define ext4_abort(sb, fmt, ...)                                        \
2244         __ext4_abort(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2245 #define ext4_warning(sb, fmt, ...)                                      \
2246         __ext4_warning(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2247 #define ext4_msg(sb, level, fmt, ...)                           \
2248         __ext4_msg(sb, level, fmt, ##__VA_ARGS__)
2249 #define dump_mmp_msg(sb, mmp, msg)                                      \
2250         __dump_mmp_msg(sb, mmp, __func__, __LINE__, msg)
2251 #define ext4_grp_locked_error(sb, grp, ino, block, fmt, ...)            \
2252         __ext4_grp_locked_error(__func__, __LINE__, sb, grp, ino, block, \
2253                                 fmt, ##__VA_ARGS__)
2254
2255 #else
2256
2257 #define ext4_error_inode(inode, func, line, block, fmt, ...)            \
2258 do {                                                                    \
2259         no_printk(fmt, ##__VA_ARGS__);                                  \
2260         __ext4_error_inode(inode, "", 0, block, " ");                   \
2261 } while (0)
2262 #define ext4_error_file(file, func, line, block, fmt, ...)              \
2263 do {                                                                    \
2264         no_printk(fmt, ##__VA_ARGS__);                                  \
2265         __ext4_error_file(file, "", 0, block, " ");                     \
2266 } while (0)
2267 #define ext4_error(sb, fmt, ...)                                        \
2268 do {                                                                    \
2269         no_printk(fmt, ##__VA_ARGS__);                                  \
2270         __ext4_error(sb, "", 0, " ");                                   \
2271 } while (0)
2272 #define ext4_abort(sb, fmt, ...)                                        \
2273 do {                                                                    \
2274         no_printk(fmt, ##__VA_ARGS__);                                  \
2275         __ext4_abort(sb, "", 0, " ");                                   \
2276 } while (0)
2277 #define ext4_warning(sb, fmt, ...)                                      \
2278 do {                                                                    \
2279         no_printk(fmt, ##__VA_ARGS__);                                  \
2280         __ext4_warning(sb, "", 0, " ");                                 \
2281 } while (0)
2282 #define ext4_msg(sb, level, fmt, ...)                                   \
2283 do {                                                                    \
2284         no_printk(fmt, ##__VA_ARGS__);                                  \
2285         __ext4_msg(sb, "", " ");                                        \
2286 } while (0)
2287 #define dump_mmp_msg(sb, mmp, msg)                                      \
2288         __dump_mmp_msg(sb, mmp, "", 0, "")
2289 #define ext4_grp_locked_error(sb, grp, ino, block, fmt, ...)            \
2290 do {                                                                    \
2291         no_printk(fmt, ##__VA_ARGS__);                          \
2292         __ext4_grp_locked_error("", 0, sb, grp, ino, block, " ");       \
2293 } while (0)
2294
2295 #endif
2296
2297 extern void ext4_update_dynamic_rev(struct super_block *sb);
2298 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
2299                                         __u32 compat);
2300 extern int ext4_update_rocompat_feature(handle_t *handle,
2301                                         struct super_block *sb, __u32 rocompat);
2302 extern int ext4_update_incompat_feature(handle_t *handle,
2303                                         struct super_block *sb, __u32 incompat);
2304 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
2305                                       struct ext4_group_desc *bg);
2306 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
2307                                       struct ext4_group_desc *bg);
2308 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
2309                                      struct ext4_group_desc *bg);
2310 extern __u32 ext4_free_group_clusters(struct super_block *sb,
2311                                       struct ext4_group_desc *bg);
2312 extern __u32 ext4_free_inodes_count(struct super_block *sb,
2313                                  struct ext4_group_desc *bg);
2314 extern __u32 ext4_used_dirs_count(struct super_block *sb,
2315                                 struct ext4_group_desc *bg);
2316 extern __u32 ext4_itable_unused_count(struct super_block *sb,
2317                                    struct ext4_group_desc *bg);
2318 extern void ext4_block_bitmap_set(struct super_block *sb,
2319                                   struct ext4_group_desc *bg, ext4_fsblk_t blk);
2320 extern void ext4_inode_bitmap_set(struct super_block *sb,
2321                                   struct ext4_group_desc *bg, ext4_fsblk_t blk);
2322 extern void ext4_inode_table_set(struct super_block *sb,
2323                                  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2324 extern void ext4_free_group_clusters_set(struct super_block *sb,
2325                                          struct ext4_group_desc *bg,
2326                                          __u32 count);
2327 extern void ext4_free_inodes_set(struct super_block *sb,
2328                                 struct ext4_group_desc *bg, __u32 count);
2329 extern void ext4_used_dirs_set(struct super_block *sb,
2330                                 struct ext4_group_desc *bg, __u32 count);
2331 extern void ext4_itable_unused_set(struct super_block *sb,
2332                                    struct ext4_group_desc *bg, __u32 count);
2333 extern int ext4_group_desc_csum_verify(struct super_block *sb, __u32 group,
2334                                        struct ext4_group_desc *gdp);
2335 extern void ext4_group_desc_csum_set(struct super_block *sb, __u32 group,
2336                                      struct ext4_group_desc *gdp);
2337 extern int ext4_register_li_request(struct super_block *sb,
2338                                     ext4_group_t first_not_zeroed);
2339
2340 static inline int ext4_has_group_desc_csum(struct super_block *sb)
2341 {
2342         return EXT4_HAS_RO_COMPAT_FEATURE(sb,
2343                                           EXT4_FEATURE_RO_COMPAT_GDT_CSUM |
2344                                           EXT4_FEATURE_RO_COMPAT_METADATA_CSUM);
2345 }
2346
2347 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
2348 {
2349         return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
2350                 le32_to_cpu(es->s_blocks_count_lo);
2351 }
2352
2353 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
2354 {
2355         return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
2356                 le32_to_cpu(es->s_r_blocks_count_lo);
2357 }
2358
2359 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
2360 {
2361         return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
2362                 le32_to_cpu(es->s_free_blocks_count_lo);
2363 }
2364
2365 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
2366                                          ext4_fsblk_t blk)
2367 {
2368         es->s_blocks_count_lo = cpu_to_le32((u32)blk);
2369         es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
2370 }
2371
2372 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
2373                                               ext4_fsblk_t blk)
2374 {
2375         es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
2376         es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
2377 }
2378
2379 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
2380                                            ext4_fsblk_t blk)
2381 {
2382         es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
2383         es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
2384 }
2385
2386 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
2387 {
2388         if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
2389                 return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
2390                         le32_to_cpu(raw_inode->i_size_lo);
2391         else
2392                 return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
2393 }
2394
2395 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
2396 {
2397         raw_inode->i_size_lo = cpu_to_le32(i_size);
2398         raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
2399 }
2400
2401 static inline
2402 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
2403                                             ext4_group_t group)
2404 {
2405          struct ext4_group_info ***grp_info;
2406          long indexv, indexh;
2407          BUG_ON(group >= EXT4_SB(sb)->s_groups_count);
2408          grp_info = EXT4_SB(sb)->s_group_info;
2409          indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
2410          indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
2411          return grp_info[indexv][indexh];
2412 }
2413
2414 /*
2415  * Reading s_groups_count requires using smp_rmb() afterwards.  See
2416  * the locking protocol documented in the comments of ext4_group_add()
2417  * in resize.c
2418  */
2419 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
2420 {
2421         ext4_group_t    ngroups = EXT4_SB(sb)->s_groups_count;
2422
2423         smp_rmb();
2424         return ngroups;
2425 }
2426
2427 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
2428                                              ext4_group_t block_group)
2429 {
2430         return block_group >> sbi->s_log_groups_per_flex;
2431 }
2432
2433 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
2434 {
2435         return 1 << sbi->s_log_groups_per_flex;
2436 }
2437
2438 #define ext4_std_error(sb, errno)                               \
2439 do {                                                            \
2440         if ((errno))                                            \
2441                 __ext4_std_error((sb), __func__, __LINE__, (errno));    \
2442 } while (0)
2443
2444 #ifdef CONFIG_SMP
2445 /* Each CPU can accumulate percpu_counter_batch clusters in their local
2446  * counters. So we need to make sure we have free clusters more
2447  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
2448  */
2449 #define EXT4_FREECLUSTERS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
2450 #else
2451 #define EXT4_FREECLUSTERS_WATERMARK 0
2452 #endif
2453
2454 /* Update i_disksize. Requires i_mutex to avoid races with truncate */
2455 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
2456 {
2457         WARN_ON_ONCE(S_ISREG(inode->i_mode) &&
2458                      !mutex_is_locked(&inode->i_mutex));
2459         down_write(&EXT4_I(inode)->i_data_sem);
2460         if (newsize > EXT4_I(inode)->i_disksize)
2461                 EXT4_I(inode)->i_disksize = newsize;
2462         up_write(&EXT4_I(inode)->i_data_sem);
2463 }
2464
2465 /*
2466  * Update i_disksize after writeback has been started. Races with truncate
2467  * are avoided by checking i_size under i_data_sem.
2468  */
2469 static inline void ext4_wb_update_i_disksize(struct inode *inode, loff_t newsize)
2470 {
2471         loff_t i_size;
2472
2473         down_write(&EXT4_I(inode)->i_data_sem);
2474         i_size = i_size_read(inode);
2475         if (newsize > i_size)
2476                 newsize = i_size;
2477         if (newsize > EXT4_I(inode)->i_disksize)
2478                 EXT4_I(inode)->i_disksize = newsize;
2479         up_write(&EXT4_I(inode)->i_data_sem);
2480 }
2481
2482 struct ext4_group_info {
2483         unsigned long   bb_state;
2484         struct rb_root  bb_free_root;
2485         ext4_grpblk_t   bb_first_free;  /* first free block */
2486         ext4_grpblk_t   bb_free;        /* total free blocks */
2487         ext4_grpblk_t   bb_fragments;   /* nr of freespace fragments */
2488         ext4_grpblk_t   bb_largest_free_order;/* order of largest frag in BG */
2489         struct          list_head bb_prealloc_list;
2490 #ifdef DOUBLE_CHECK
2491         void            *bb_bitmap;
2492 #endif
2493         struct rw_semaphore alloc_sem;
2494         ext4_grpblk_t   bb_counters[];  /* Nr of free power-of-two-block
2495                                          * regions, index is order.
2496                                          * bb_counters[3] = 5 means
2497                                          * 5 free 8-block regions. */
2498 };
2499
2500 #define EXT4_GROUP_INFO_NEED_INIT_BIT           0
2501 #define EXT4_GROUP_INFO_WAS_TRIMMED_BIT         1
2502 #define EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT     2
2503 #define EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT     3
2504
2505 #define EXT4_MB_GRP_NEED_INIT(grp)      \
2506         (test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
2507 #define EXT4_MB_GRP_BBITMAP_CORRUPT(grp)        \
2508         (test_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
2509 #define EXT4_MB_GRP_IBITMAP_CORRUPT(grp)        \
2510         (test_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
2511
2512 #define EXT4_MB_GRP_WAS_TRIMMED(grp)    \
2513         (test_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2514 #define EXT4_MB_GRP_SET_TRIMMED(grp)    \
2515         (set_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2516 #define EXT4_MB_GRP_CLEAR_TRIMMED(grp)  \
2517         (clear_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2518
2519 #define EXT4_MAX_CONTENTION             8
2520 #define EXT4_CONTENTION_THRESHOLD       2
2521
2522 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
2523                                               ext4_group_t group)
2524 {
2525         return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
2526 }
2527
2528 /*
2529  * Returns true if the filesystem is busy enough that attempts to
2530  * access the block group locks has run into contention.
2531  */
2532 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
2533 {
2534         return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
2535 }
2536
2537 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
2538 {
2539         spinlock_t *lock = ext4_group_lock_ptr(sb, group);
2540         if (spin_trylock(lock))
2541                 /*
2542                  * We're able to grab the lock right away, so drop the
2543                  * lock contention counter.
2544                  */
2545                 atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
2546         else {
2547                 /*
2548                  * The lock is busy, so bump the contention counter,
2549                  * and then wait on the spin lock.
2550                  */
2551                 atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
2552                                   EXT4_MAX_CONTENTION);
2553                 spin_lock(lock);
2554         }
2555 }
2556
2557 static inline void ext4_unlock_group(struct super_block *sb,
2558                                         ext4_group_t group)
2559 {
2560         spin_unlock(ext4_group_lock_ptr(sb, group));
2561 }
2562
2563 /*
2564  * Block validity checking
2565  */
2566 #define ext4_check_indirect_blockref(inode, bh)                         \
2567         ext4_check_blockref(__func__, __LINE__, inode,                  \
2568                             (__le32 *)(bh)->b_data,                     \
2569                             EXT4_ADDR_PER_BLOCK((inode)->i_sb))
2570
2571 #define ext4_ind_check_inode(inode)                                     \
2572         ext4_check_blockref(__func__, __LINE__, inode,                  \
2573                             EXT4_I(inode)->i_data,                      \
2574                             EXT4_NDIR_BLOCKS)
2575
2576 /*
2577  * Inodes and files operations
2578  */
2579
2580 /* dir.c */
2581 extern const struct file_operations ext4_dir_operations;
2582
2583 /* file.c */
2584 extern const struct inode_operations ext4_file_inode_operations;
2585 extern const struct file_operations ext4_file_operations;
2586 extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
2587 extern void ext4_unwritten_wait(struct inode *inode);
2588
2589 /* inline.c */
2590 extern int ext4_has_inline_data(struct inode *inode);
2591 extern int ext4_get_inline_size(struct inode *inode);
2592 extern int ext4_get_max_inline_size(struct inode *inode);
2593 extern int ext4_find_inline_data_nolock(struct inode *inode);
2594 extern void ext4_write_inline_data(struct inode *inode,
2595                                    struct ext4_iloc *iloc,
2596                                    void *buffer, loff_t pos,
2597                                    unsigned int len);
2598 extern int ext4_prepare_inline_data(handle_t *handle, struct inode *inode,
2599                                     unsigned int len);
2600 extern int ext4_init_inline_data(handle_t *handle, struct inode *inode,
2601                                  unsigned int len);
2602 extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);
2603
2604 extern int ext4_readpage_inline(struct inode *inode, struct page *page);
2605 extern int ext4_try_to_write_inline_data(struct address_space *mapping,
2606                                          struct inode *inode,
2607                                          loff_t pos, unsigned len,
2608                                          unsigned flags,
2609                                          struct page **pagep);
2610 extern int ext4_write_inline_data_end(struct inode *inode,
2611                                       loff_t pos, unsigned len,
2612                                       unsigned copied,
2613                                       struct page *page);
2614 extern struct buffer_head *
2615 ext4_journalled_write_inline_data(struct inode *inode,
2616                                   unsigned len,
2617                                   struct page *page);
2618 extern int ext4_da_write_inline_data_begin(struct address_space *mapping,
2619                                            struct inode *inode,
2620                                            loff_t pos, unsigned len,
2621                                            unsigned flags,
2622                                            struct page **pagep,
2623                                            void **fsdata);
2624 extern int ext4_da_write_inline_data_end(struct inode *inode, loff_t pos,
2625                                          unsigned len, unsigned copied,
2626                                          struct page *page);
2627 extern int ext4_try_add_inline_entry(handle_t *handle, struct dentry *dentry,
2628                                      struct inode *inode);
2629 extern int ext4_try_create_inline_dir(handle_t *handle,
2630                                       struct inode *parent,
2631                                       struct inode *inode);
2632 extern int ext4_read_inline_dir(struct file *filp,
2633                                 struct dir_context *ctx,
2634                                 int *has_inline_data);
2635 extern int htree_inlinedir_to_tree(struct file *dir_file,
2636                                    struct inode *dir, ext4_lblk_t block,
2637                                    struct dx_hash_info *hinfo,
2638                                    __u32 start_hash, __u32 start_minor_hash,
2639                                    int *has_inline_data);
2640 extern struct buffer_head *ext4_find_inline_entry(struct inode *dir,
2641                                         const struct qstr *d_name,
2642                                         struct ext4_dir_entry_2 **res_dir,
2643                                         int *has_inline_data);
2644 extern int ext4_delete_inline_entry(handle_t *handle,
2645                                     struct inode *dir,
2646                                     struct ext4_dir_entry_2 *de_del,
2647                                     struct buffer_head *bh,
2648                                     int *has_inline_data);
2649 extern int empty_inline_dir(struct inode *dir, int *has_inline_data);
2650 extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
2651                                         struct ext4_dir_entry_2 **parent_de,
2652                                         int *retval);
2653 extern int ext4_inline_data_fiemap(struct inode *inode,
2654                                    struct fiemap_extent_info *fieinfo,
2655                                    int *has_inline);
2656 extern int ext4_try_to_evict_inline_data(handle_t *handle,
2657                                          struct inode *inode,
2658                                          int needed);
2659 extern void ext4_inline_data_truncate(struct inode *inode, int *has_inline);
2660
2661 extern int ext4_convert_inline_data(struct inode *inode);
2662
2663 /* namei.c */
2664 extern const struct inode_operations ext4_dir_inode_operations;
2665 extern const struct inode_operations ext4_special_inode_operations;
2666 extern struct dentry *ext4_get_parent(struct dentry *child);
2667 extern struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2668                                  struct ext4_dir_entry_2 *de,
2669                                  int blocksize, int csum_size,
2670                                  unsigned int parent_ino, int dotdot_real_len);
2671 extern void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
2672                                    unsigned int blocksize);
2673 extern int ext4_handle_dirty_dirent_node(handle_t *handle,
2674                                          struct inode *inode,
2675                                          struct buffer_head *bh);
2676 #define S_SHIFT 12
2677 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
2678         [S_IFREG >> S_SHIFT]    = EXT4_FT_REG_FILE,
2679         [S_IFDIR >> S_SHIFT]    = EXT4_FT_DIR,
2680         [S_IFCHR >> S_SHIFT]    = EXT4_FT_CHRDEV,
2681         [S_IFBLK >> S_SHIFT]    = EXT4_FT_BLKDEV,
2682         [S_IFIFO >> S_SHIFT]    = EXT4_FT_FIFO,
2683         [S_IFSOCK >> S_SHIFT]   = EXT4_FT_SOCK,
2684         [S_IFLNK >> S_SHIFT]    = EXT4_FT_SYMLINK,
2685 };
2686
2687 static inline void ext4_set_de_type(struct super_block *sb,
2688                                 struct ext4_dir_entry_2 *de,
2689                                 umode_t mode) {
2690         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
2691                 de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
2692 }
2693
2694
2695 /* symlink.c */
2696 extern const struct inode_operations ext4_symlink_inode_operations;
2697 extern const struct inode_operations ext4_fast_symlink_inode_operations;
2698
2699 /* block_validity */
2700 extern void ext4_release_system_zone(struct super_block *sb);
2701 extern int ext4_setup_system_zone(struct super_block *sb);
2702 extern int __init ext4_init_system_zone(void);
2703 extern void ext4_exit_system_zone(void);
2704 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
2705                                  ext4_fsblk_t start_blk,
2706                                  unsigned int count);
2707 extern int ext4_check_blockref(const char *, unsigned int,
2708                                struct inode *, __le32 *, unsigned int);
2709
2710 /* extents.c */
2711 struct ext4_ext_path;
2712 struct ext4_extent;
2713
2714 /*
2715  * Maximum number of logical blocks in a file; ext4_extent's ee_block is
2716  * __le32.
2717  */
2718 #define EXT_MAX_BLOCKS  0xffffffff
2719
2720 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
2721 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
2722 extern int ext4_ext_index_trans_blocks(struct inode *inode, int extents);
2723 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
2724                                struct ext4_map_blocks *map, int flags);
2725 extern void ext4_ext_truncate(handle_t *, struct inode *);
2726 extern int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2727                                  ext4_lblk_t end);
2728 extern void ext4_ext_init(struct super_block *);
2729 extern void ext4_ext_release(struct super_block *);
2730 extern long ext4_fallocate(struct file *file, int mode, loff_t offset,
2731                           loff_t len);
2732 extern int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
2733                                           loff_t offset, ssize_t len);
2734 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
2735                            struct ext4_map_blocks *map, int flags);
2736 extern int ext4_ext_calc_metadata_amount(struct inode *inode,
2737                                          ext4_lblk_t lblocks);
2738 extern int ext4_extent_tree_init(handle_t *, struct inode *);
2739 extern int ext4_ext_calc_credits_for_single_extent(struct inode *inode,
2740                                                    int num,
2741                                                    struct ext4_ext_path *path);
2742 extern int ext4_can_extents_be_merged(struct inode *inode,
2743                                       struct ext4_extent *ex1,
2744                                       struct ext4_extent *ex2);
2745 extern int ext4_ext_insert_extent(handle_t *, struct inode *,
2746                                   struct ext4_ext_path *,
2747                                   struct ext4_extent *, int);
2748 extern struct ext4_ext_path *ext4_ext_find_extent(struct inode *, ext4_lblk_t,
2749                                                   struct ext4_ext_path *,
2750                                                   int flags);
2751 extern void ext4_ext_drop_refs(struct ext4_ext_path *);
2752 extern int ext4_ext_check_inode(struct inode *inode);
2753 extern int ext4_find_delalloc_range(struct inode *inode,
2754                                     ext4_lblk_t lblk_start,
2755                                     ext4_lblk_t lblk_end);
2756 extern int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk);
2757 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
2758                         __u64 start, __u64 len);
2759 extern int ext4_ext_precache(struct inode *inode);
2760
2761 /* move_extent.c */
2762 extern void ext4_double_down_write_data_sem(struct inode *first,
2763                                             struct inode *second);
2764 extern void ext4_double_up_write_data_sem(struct inode *orig_inode,
2765                                           struct inode *donor_inode);
2766 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
2767                              __u64 start_orig, __u64 start_donor,
2768                              __u64 len, __u64 *moved_len);
2769
2770 /* page-io.c */
2771 extern int __init ext4_init_pageio(void);
2772 extern void ext4_exit_pageio(void);
2773 extern ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags);
2774 extern ext4_io_end_t *ext4_get_io_end(ext4_io_end_t *io_end);
2775 extern int ext4_put_io_end(ext4_io_end_t *io_end);
2776 extern void ext4_put_io_end_defer(ext4_io_end_t *io_end);
2777 extern void ext4_io_submit_init(struct ext4_io_submit *io,
2778                                 struct writeback_control *wbc);
2779 extern void ext4_end_io_rsv_work(struct work_struct *work);
2780 extern void ext4_io_submit(struct ext4_io_submit *io);
2781 extern int ext4_bio_write_page(struct ext4_io_submit *io,
2782                                struct page *page,
2783                                int len,
2784                                struct writeback_control *wbc);
2785
2786 /* mmp.c */
2787 extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
2788 extern void ext4_mmp_csum_set(struct super_block *sb, struct mmp_struct *mmp);
2789 extern int ext4_mmp_csum_verify(struct super_block *sb,
2790                                 struct mmp_struct *mmp);
2791
2792 /*
2793  * Note that these flags will never ever appear in a buffer_head's state flag.
2794  * See EXT4_MAP_... to see where this is used.
2795  */
2796 enum ext4_state_bits {
2797         BH_Uninit       /* blocks are allocated but uninitialized on disk */
2798          = BH_JBDPrivateStart,
2799         BH_AllocFromCluster,    /* allocated blocks were part of already
2800                                  * allocated cluster. */
2801 };
2802
2803 /*
2804  * Add new method to test whether block and inode bitmaps are properly
2805  * initialized. With uninit_bg reading the block from disk is not enough
2806  * to mark the bitmap uptodate. We need to also zero-out the bitmap
2807  */
2808 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
2809
2810 static inline int bitmap_uptodate(struct buffer_head *bh)
2811 {
2812         return (buffer_uptodate(bh) &&
2813                         test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
2814 }
2815 static inline void set_bitmap_uptodate(struct buffer_head *bh)
2816 {
2817         set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
2818 }
2819
2820 /*
2821  * Disable DIO read nolock optimization, so new dioreaders will be forced
2822  * to grab i_mutex
2823  */
2824 static inline void ext4_inode_block_unlocked_dio(struct inode *inode)
2825 {
2826         ext4_set_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
2827         smp_mb();
2828 }
2829 static inline void ext4_inode_resume_unlocked_dio(struct inode *inode)
2830 {
2831         smp_mb();
2832         ext4_clear_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
2833 }
2834
2835 #define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
2836
2837 /* For ioend & aio unwritten conversion wait queues */
2838 #define EXT4_WQ_HASH_SZ         37
2839 #define ext4_ioend_wq(v)   (&ext4__ioend_wq[((unsigned long)(v)) %\
2840                                             EXT4_WQ_HASH_SZ])
2841 #define ext4_aio_mutex(v)  (&ext4__aio_mutex[((unsigned long)(v)) %\
2842                                              EXT4_WQ_HASH_SZ])
2843 extern wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
2844 extern struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
2845
2846 #define EXT4_RESIZING   0
2847 extern int ext4_resize_begin(struct super_block *sb);
2848 extern void ext4_resize_end(struct super_block *sb);
2849
2850 #endif  /* __KERNEL__ */
2851
2852 #endif  /* _EXT4_H */