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 #include <linux/falloc.h>
  35 #ifdef __KERNEL__
  36 #include <linux/compat.h>
  37 #endif
  38
  39 /*
  40  * The fourth extended filesystem constants/structures
  41  */
  42
  43 /*
  44  * Define EXT4FS_DEBUG to produce debug messages
  45  */
  46 #undef EXT4FS_DEBUG
  47
  48 /*
  49  * Debug code
  50  */
  51 #ifdef EXT4FS_DEBUG
  52 #define ext4_debug(f, a...)                                             \
  53         do {                                                            \
  54                 printk(KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:",        \
  55                         __FILE__, __LINE__, __func__);                  \
  56                 printk(KERN_DEBUG f, ## a);                             \
  57         } while (0)
  58 #else
  59 #define ext4_debug(fmt, ...)    no_printk(fmt, ##__VA_ARGS__)
  60 #endif
  61
  62 /*
  63  * Turn on EXT_DEBUG to get lots of info about extents operations.
  64  */
  65 #define EXT_DEBUG__
  66 #ifdef EXT_DEBUG
  67 #define ext_debug(fmt, ...)     printk(fmt, ##__VA_ARGS__)
  68 #else
  69 #define ext_debug(fmt, ...)     no_printk(fmt, ##__VA_ARGS__)
  70 #endif
  71
  72 #define EXT4_ERROR_INODE(inode, fmt, a...) \
  73         ext4_error_inode((inode), __func__, __LINE__, 0, (fmt), ## a)
  74
  75 #define EXT4_ERROR_INODE_BLOCK(inode, block, fmt, a...)                 \
  76         ext4_error_inode((inode), __func__, __LINE__, (block), (fmt), ## a)
  77
  78 #define EXT4_ERROR_FILE(file, block, fmt, a...)                         \
  79         ext4_error_file((file), __func__, __LINE__, (block), (fmt), ## a)
  80
  81 /* data type for block offset of block group */
  82 typedef int ext4_grpblk_t;
  83
  84 /* data type for filesystem-wide blocks number */
  85 typedef unsigned long long ext4_fsblk_t;
  86
  87 /* data type for file logical block number */
  88 typedef __u32 ext4_lblk_t;
  89
  90 /* data type for block group number */
  91 typedef unsigned int ext4_group_t;
  92
  93 /*
  94  * Flags used in mballoc's allocation_context flags field.
  95  *
  96  * Also used to show what's going on for debugging purposes when the
  97  * flag field is exported via the traceport interface
  98  */
  99
 100 /* prefer goal again. length */
 101 #define EXT4_MB_HINT_MERGE              0x0001
 102 /* blocks already reserved */
 103 #define EXT4_MB_HINT_RESERVED           0x0002
 104 /* metadata is being allocated */
 105 #define EXT4_MB_HINT_METADATA           0x0004
 106 /* first blocks in the file */
 107 #define EXT4_MB_HINT_FIRST              0x0008
 108 /* search for the best chunk */
 109 #define EXT4_MB_HINT_BEST               0x0010
 110 /* data is being allocated */
 111 #define EXT4_MB_HINT_DATA               0x0020
 112 /* don't preallocate (for tails) */
 113 #define EXT4_MB_HINT_NOPREALLOC         0x0040
 114 /* allocate for locality group */
 115 #define EXT4_MB_HINT_GROUP_ALLOC        0x0080
 116 /* allocate goal blocks or none */
 117 #define EXT4_MB_HINT_GOAL_ONLY          0x0100
 118 /* goal is meaningful */
 119 #define EXT4_MB_HINT_TRY_GOAL           0x0200
 120 /* blocks already pre-reserved by delayed allocation */
 121 #define EXT4_MB_DELALLOC_RESERVED       0x0400
 122 /* We are doing stream allocation */
 123 #define EXT4_MB_STREAM_ALLOC            0x0800
 124 /* Use reserved root blocks if needed */
 125 #define EXT4_MB_USE_ROOT_BLOCKS         0x1000
 126 /* Use blocks from reserved pool */
 127 #define EXT4_MB_USE_RESERVED            0x2000
 128
 129 struct ext4_allocation_request {
 130         /* target inode for block we're allocating */
 131         struct inode *inode;
 132         /* how many blocks we want to allocate */
 133         unsigned int len;
 134         /* logical block in target inode */
 135         ext4_lblk_t logical;
 136         /* the closest logical allocated block to the left */
 137         ext4_lblk_t lleft;
 138         /* the closest logical allocated block to the right */
 139         ext4_lblk_t lright;
 140         /* phys. target (a hint) */
 141         ext4_fsblk_t goal;
 142         /* phys. block for the closest logical allocated block to the left */
 143         ext4_fsblk_t pleft;
 144         /* phys. block for the closest logical allocated block to the right */
 145         ext4_fsblk_t pright;
 146         /* flags. see above EXT4_MB_HINT_* */
 147         unsigned int flags;
 148 };
 149
 150 /*
 151  * Logical to physical block mapping, used by ext4_map_blocks()
 152  *
 153  * This structure is used to pass requests into ext4_map_blocks() as
 154  * well as to store the information returned by ext4_map_blocks().  It
 155  * takes less room on the stack than a struct buffer_head.
 156  */
 157 #define EXT4_MAP_NEW            (1 << BH_New)
 158 #define EXT4_MAP_MAPPED         (1 << BH_Mapped)
 159 #define EXT4_MAP_UNWRITTEN      (1 << BH_Unwritten)
 160 #define EXT4_MAP_BOUNDARY       (1 << BH_Boundary)
 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_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 unwritten 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 unwritten
 540            extent to be an initialized ext4 */
 541 #define EXT4_GET_BLOCKS_CREATE                  0x0001
 542         /* Request the creation of an unwritten extent */
 543 #define EXT4_GET_BLOCKS_UNWRIT_EXT              0x0002
 544 #define EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT       (EXT4_GET_BLOCKS_UNWRIT_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         unwritten extents if not allocated, split the unwritten
 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_UNWRIT_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_UNWRIT_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         /* Convert written extents to unwritten */
 571 #define EXT4_GET_BLOCKS_CONVERT_UNWRITTEN       0x0400
 572
 573 /*
 574  * The bit position of these flags must not overlap with any of the
 575  * EXT4_GET_BLOCKS_*.  They are used by ext4_find_extent(),
 576  * read_extent_tree_block(), ext4_split_extent_at(),
 577  * ext4_ext_insert_extent(), and ext4_ext_create_new_leaf().
 578  * EXT4_EX_NOCACHE is used to indicate that the we shouldn't be
 579  * caching the extents when reading from the extent tree while a
 580  * truncate or punch hole operation is in progress.
 581  */
 582 #define EXT4_EX_NOCACHE                         0x40000000
 583 #define EXT4_EX_FORCE_CACHE                     0x20000000
 584
 585 /*
 586  * Flags used by ext4_free_blocks
 587  */
 588 #define EXT4_FREE_BLOCKS_METADATA       0x0001
 589 #define EXT4_FREE_BLOCKS_FORGET         0x0002
 590 #define EXT4_FREE_BLOCKS_VALIDATED      0x0004
 591 #define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE 0x0008
 592 #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER   0x0010
 593 #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER    0x0020
 594
 595 /*
 596  * ioctl commands
 597  */
 598 #define EXT4_IOC_GETFLAGS               FS_IOC_GETFLAGS
 599 #define EXT4_IOC_SETFLAGS               FS_IOC_SETFLAGS
 600 #define EXT4_IOC_GETVERSION             _IOR('f', 3, long)
 601 #define EXT4_IOC_SETVERSION             _IOW('f', 4, long)
 602 #define EXT4_IOC_GETVERSION_OLD         FS_IOC_GETVERSION
 603 #define EXT4_IOC_SETVERSION_OLD         FS_IOC_SETVERSION
 604 #define EXT4_IOC_GETRSVSZ               _IOR('f', 5, long)
 605 #define EXT4_IOC_SETRSVSZ               _IOW('f', 6, long)
 606 #define EXT4_IOC_GROUP_EXTEND           _IOW('f', 7, unsigned long)
 607 #define EXT4_IOC_GROUP_ADD              _IOW('f', 8, struct ext4_new_group_input)
 608 #define EXT4_IOC_MIGRATE                _IO('f', 9)
 609  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
 610  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
 611 #define EXT4_IOC_ALLOC_DA_BLKS          _IO('f', 12)
 612 #define EXT4_IOC_MOVE_EXT               _IOWR('f', 15, struct move_extent)
 613 #define EXT4_IOC_RESIZE_FS              _IOW('f', 16, __u64)
 614 #define EXT4_IOC_SWAP_BOOT              _IO('f', 17)
 615 #define EXT4_IOC_PRECACHE_EXTENTS       _IO('f', 18)
 616
 617 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
 618 /*
 619  * ioctl commands in 32 bit emulation
 620  */
 621 #define EXT4_IOC32_GETFLAGS             FS_IOC32_GETFLAGS
 622 #define EXT4_IOC32_SETFLAGS             FS_IOC32_SETFLAGS
 623 #define EXT4_IOC32_GETVERSION           _IOR('f', 3, int)
 624 #define EXT4_IOC32_SETVERSION           _IOW('f', 4, int)
 625 #define EXT4_IOC32_GETRSVSZ             _IOR('f', 5, int)
 626 #define EXT4_IOC32_SETRSVSZ             _IOW('f', 6, int)
 627 #define EXT4_IOC32_GROUP_EXTEND         _IOW('f', 7, unsigned int)
 628 #define EXT4_IOC32_GROUP_ADD            _IOW('f', 8, struct compat_ext4_new_group_input)
 629 #define EXT4_IOC32_GETVERSION_OLD       FS_IOC32_GETVERSION
 630 #define EXT4_IOC32_SETVERSION_OLD       FS_IOC32_SETVERSION
 631 #endif
 632
 633 /* Max physical block we can address w/o extents */
 634 #define EXT4_MAX_BLOCK_FILE_PHYS        0xFFFFFFFF
 635
 636 /*
 637  * Structure of an inode on the disk
 638  */
 639 struct ext4_inode {
 640         __le16  i_mode;         /* File mode */
 641         __le16  i_uid;          /* Low 16 bits of Owner Uid */
 642         __le32  i_size_lo;      /* Size in bytes */
 643         __le32  i_atime;        /* Access time */
 644         __le32  i_ctime;        /* Inode Change time */
 645         __le32  i_mtime;        /* Modification time */
 646         __le32  i_dtime;        /* Deletion Time */
 647         __le16  i_gid;          /* Low 16 bits of Group Id */
 648         __le16  i_links_count;  /* Links count */
 649         __le32  i_blocks_lo;    /* Blocks count */
 650         __le32  i_flags;        /* File flags */
 651         union {
 652                 struct {
 653                         __le32  l_i_version;
 654                 } linux1;
 655                 struct {
 656                         __u32  h_i_translator;
 657                 } hurd1;
 658                 struct {
 659                         __u32  m_i_reserved1;
 660                 } masix1;
 661         } osd1;                         /* OS dependent 1 */
 662         __le32  i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
 663         __le32  i_generation;   /* File version (for NFS) */
 664         __le32  i_file_acl_lo;  /* File ACL */
 665         __le32  i_size_high;
 666         __le32  i_obso_faddr;   /* Obsoleted fragment address */
 667         union {
 668                 struct {
 669                         __le16  l_i_blocks_high; /* were l_i_reserved1 */
 670                         __le16  l_i_file_acl_high;
 671                         __le16  l_i_uid_high;   /* these 2 fields */
 672                         __le16  l_i_gid_high;   /* were reserved2[0] */
 673                         __le16  l_i_checksum_lo;/* crc32c(uuid+inum+inode) LE */
 674                         __le16  l_i_reserved;
 675                 } linux2;
 676                 struct {
 677                         __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
 678                         __u16   h_i_mode_high;
 679                         __u16   h_i_uid_high;
 680                         __u16   h_i_gid_high;
 681                         __u32   h_i_author;
 682                 } hurd2;
 683                 struct {
 684                         __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
 685                         __le16  m_i_file_acl_high;
 686                         __u32   m_i_reserved2[2];
 687                 } masix2;
 688         } osd2;                         /* OS dependent 2 */
 689         __le16  i_extra_isize;
 690         __le16  i_checksum_hi;  /* crc32c(uuid+inum+inode) BE */
 691         __le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
 692         __le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
 693         __le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
 694         __le32  i_crtime;       /* File Creation time */
 695         __le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
 696         __le32  i_version_hi;   /* high 32 bits for 64-bit version */
 697 };
 698
 699 struct move_extent {
 700         __u32 reserved;         /* should be zero */
 701         __u32 donor_fd;         /* donor file descriptor */
 702         __u64 orig_start;       /* logical start offset in block for orig */
 703         __u64 donor_start;      /* logical start offset in block for donor */
 704         __u64 len;              /* block length to be moved */
 705         __u64 moved_len;        /* moved block length */
 706 };
 707
 708 #define EXT4_EPOCH_BITS 2
 709 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
 710 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
 711
 712 /*
 713  * Extended fields will fit into an inode if the filesystem was formatted
 714  * with large inodes (-I 256 or larger) and there are not currently any EAs
 715  * consuming all of the available space. For new inodes we always reserve
 716  * enough space for the kernel's known extended fields, but for inodes
 717  * created with an old kernel this might not have been the case. None of
 718  * the extended inode fields is critical for correct filesystem operation.
 719  * This macro checks if a certain field fits in the inode. Note that
 720  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
 721  */
 722 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)   \
 723         ((offsetof(typeof(*ext4_inode), field) +        \
 724           sizeof((ext4_inode)->field))                  \
 725         <= (EXT4_GOOD_OLD_INODE_SIZE +                  \
 726             (einode)->i_extra_isize))                   \
 727
 728 static inline __le32 ext4_encode_extra_time(struct timespec *time)
 729 {
 730        return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
 731                            (time->tv_sec >> 32) & EXT4_EPOCH_MASK : 0) |
 732                           ((time->tv_nsec << EXT4_EPOCH_BITS) & EXT4_NSEC_MASK));
 733 }
 734
 735 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
 736 {
 737        if (sizeof(time->tv_sec) > 4)
 738                time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
 739                                << 32;
 740        time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
 741 }
 742
 743 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)                          \
 744 do {                                                                           \
 745         (raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);               \
 746         if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
 747                 (raw_inode)->xtime ## _extra =                                 \
 748                                 ext4_encode_extra_time(&(inode)->xtime);       \
 749 } while (0)
 750
 751 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)                        \
 752 do {                                                                           \
 753         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))                      \
 754                 (raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
 755         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))            \
 756                 (raw_inode)->xtime ## _extra =                                 \
 757                                 ext4_encode_extra_time(&(einode)->xtime);      \
 758 } while (0)
 759
 760 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)                          \
 761 do {                                                                           \
 762         (inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
 763         if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
 764                 ext4_decode_extra_time(&(inode)->xtime,                        \
 765                                        raw_inode->xtime ## _extra);            \
 766         else                                                                   \
 767                 (inode)->xtime.tv_nsec = 0;                                    \
 768 } while (0)
 769
 770 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)                        \
 771 do {                                                                           \
 772         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))                      \
 773                 (einode)->xtime.tv_sec =                                       \
 774                         (signed)le32_to_cpu((raw_inode)->xtime);               \
 775         else                                                                   \
 776                 (einode)->xtime.tv_sec = 0;                                    \
 777         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))            \
 778                 ext4_decode_extra_time(&(einode)->xtime,                       \
 779                                        raw_inode->xtime ## _extra);            \
 780         else                                                                   \
 781                 (einode)->xtime.tv_nsec = 0;                                   \
 782 } while (0)
 783
 784 #define i_disk_version osd1.linux1.l_i_version
 785
 786 #if defined(__KERNEL__) || defined(__linux__)
 787 #define i_reserved1     osd1.linux1.l_i_reserved1
 788 #define i_file_acl_high osd2.linux2.l_i_file_acl_high
 789 #define i_blocks_high   osd2.linux2.l_i_blocks_high
 790 #define i_uid_low       i_uid
 791 #define i_gid_low       i_gid
 792 #define i_uid_high      osd2.linux2.l_i_uid_high
 793 #define i_gid_high      osd2.linux2.l_i_gid_high
 794 #define i_checksum_lo   osd2.linux2.l_i_checksum_lo
 795
 796 #elif defined(__GNU__)
 797
 798 #define i_translator    osd1.hurd1.h_i_translator
 799 #define i_uid_high      osd2.hurd2.h_i_uid_high
 800 #define i_gid_high      osd2.hurd2.h_i_gid_high
 801 #define i_author        osd2.hurd2.h_i_author
 802
 803 #elif defined(__masix__)
 804
 805 #define i_reserved1     osd1.masix1.m_i_reserved1
 806 #define i_file_acl_high osd2.masix2.m_i_file_acl_high
 807 #define i_reserved2     osd2.masix2.m_i_reserved2
 808
 809 #endif /* defined(__KERNEL__) || defined(__linux__) */
 810
 811 #include "extents_status.h"
 812
 813 /*
 814  * fourth extended file system inode data in memory
 815  */
 816 struct ext4_inode_info {
 817         __le32  i_data[15];     /* unconverted */
 818         __u32   i_dtime;
 819         ext4_fsblk_t    i_file_acl;
 820
 821         /*
 822          * i_block_group is the number of the block group which contains
 823          * this file's inode.  Constant across the lifetime of the inode,
 824          * it is ued for making block allocation decisions - we try to
 825          * place a file's data blocks near its inode block, and new inodes
 826          * near to their parent directory's inode.
 827          */
 828         ext4_group_t    i_block_group;
 829         ext4_lblk_t     i_dir_start_lookup;
 830 #if (BITS_PER_LONG < 64)
 831         unsigned long   i_state_flags;          /* Dynamic state flags */
 832 #endif
 833         unsigned long   i_flags;
 834
 835         /*
 836          * Extended attributes can be read independently of the main file
 837          * data. Taking i_mutex even when reading would cause contention
 838          * between readers of EAs and writers of regular file data, so
 839          * instead we synchronize on xattr_sem when reading or changing
 840          * EAs.
 841          */
 842         struct rw_semaphore xattr_sem;
 843
 844         struct list_head i_orphan;      /* unlinked but open inodes */
 845
 846         /*
 847          * i_disksize keeps track of what the inode size is ON DISK, not
 848          * in memory.  During truncate, i_size is set to the new size by
 849          * the VFS prior to calling ext4_truncate(), but the filesystem won't
 850          * set i_disksize to 0 until the truncate is actually under way.
 851          *
 852          * The intent is that i_disksize always represents the blocks which
 853          * are used by this file.  This allows recovery to restart truncate
 854          * on orphans if we crash during truncate.  We actually write i_disksize
 855          * into the on-disk inode when writing inodes out, instead of i_size.
 856          *
 857          * The only time when i_disksize and i_size may be different is when
 858          * a truncate is in progress.  The only things which change i_disksize
 859          * are ext4_get_block (growth) and ext4_truncate (shrinkth).
 860          */
 861         loff_t  i_disksize;
 862
 863         /*
 864          * i_data_sem is for serialising ext4_truncate() against
 865          * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
 866          * data tree are chopped off during truncate. We can't do that in
 867          * ext4 because whenever we perform intermediate commits during
 868          * truncate, the inode and all the metadata blocks *must* be in a
 869          * consistent state which allows truncation of the orphans to restart
 870          * during recovery.  Hence we must fix the get_block-vs-truncate race
 871          * by other means, so we have i_data_sem.
 872          */
 873         struct rw_semaphore i_data_sem;
 874         struct inode vfs_inode;
 875         struct jbd2_inode *jinode;
 876
 877         spinlock_t i_raw_lock;  /* protects updates to the raw inode */
 878
 879         /*
 880          * File creation time. Its function is same as that of
 881          * struct timespec i_{a,c,m}time in the generic inode.
 882          */
 883         struct timespec i_crtime;
 884
 885         /* mballoc */
 886         struct list_head i_prealloc_list;
 887         spinlock_t i_prealloc_lock;
 888
 889         /* extents status tree */
 890         struct ext4_es_tree i_es_tree;
 891         rwlock_t i_es_lock;
 892         struct list_head i_es_lru;
 893         unsigned int i_es_all_nr;       /* protected by i_es_lock */
 894         unsigned int i_es_lru_nr;       /* protected by i_es_lock */
 895         unsigned long i_touch_when;     /* jiffies of last accessing */
 896
 897         /* ialloc */
 898         ext4_group_t    i_last_alloc_group;
 899
 900         /* allocation reservation info for delalloc */
 901         /* In case of bigalloc, these refer to clusters rather than blocks */
 902         unsigned int i_reserved_data_blocks;
 903         unsigned int i_reserved_meta_blocks;
 904         unsigned int i_allocated_meta_blocks;
 905         ext4_lblk_t i_da_metadata_calc_last_lblock;
 906         int i_da_metadata_calc_len;
 907
 908         /* on-disk additional length */
 909         __u16 i_extra_isize;
 910
 911         /* Indicate the inline data space. */
 912         u16 i_inline_off;
 913         u16 i_inline_size;
 914
 915 #ifdef CONFIG_QUOTA
 916         /* quota space reservation, managed internally by quota code */
 917         qsize_t i_reserved_quota;
 918 #endif
 919
 920         /* Lock protecting lists below */
 921         spinlock_t i_completed_io_lock;
 922         /*
 923          * Completed IOs that need unwritten extents handling and have
 924          * transaction reserved
 925          */
 926         struct list_head i_rsv_conversion_list;
 927         /*
 928          * Completed IOs that need unwritten extents handling and don't have
 929          * transaction reserved
 930          */
 931         atomic_t i_ioend_count; /* Number of outstanding io_end structs */
 932         atomic_t i_unwritten; /* Nr. of inflight conversions pending */
 933         struct work_struct i_rsv_conversion_work;
 934
 935         spinlock_t i_block_reservation_lock;
 936
 937         /*
 938          * Transactions that contain inode's metadata needed to complete
 939          * fsync and fdatasync, respectively.
 940          */
 941         tid_t i_sync_tid;
 942         tid_t i_datasync_tid;
 943
 944 #ifdef CONFIG_QUOTA
 945         struct dquot *i_dquot[MAXQUOTAS];
 946 #endif
 947
 948         /* Precomputed uuid+inum+igen checksum for seeding inode checksums */
 949         __u32 i_csum_seed;
 950 };
 951
 952 /*
 953  * File system states
 954  */
 955 #define EXT4_VALID_FS                   0x0001  /* Unmounted cleanly */
 956 #define EXT4_ERROR_FS                   0x0002  /* Errors detected */
 957 #define EXT4_ORPHAN_FS                  0x0004  /* Orphans being recovered */
 958
 959 /*
 960  * Misc. filesystem flags
 961  */
 962 #define EXT2_FLAGS_SIGNED_HASH          0x0001  /* Signed dirhash in use */
 963 #define EXT2_FLAGS_UNSIGNED_HASH        0x0002  /* Unsigned dirhash in use */
 964 #define EXT2_FLAGS_TEST_FILESYS         0x0004  /* to test development code */
 965
 966 /*
 967  * Mount flags set via mount options or defaults
 968  */
 969 #define EXT4_MOUNT_GRPID                0x00004 /* Create files with directory's group */
 970 #define EXT4_MOUNT_DEBUG                0x00008 /* Some debugging messages */
 971 #define EXT4_MOUNT_ERRORS_CONT          0x00010 /* Continue on errors */
 972 #define EXT4_MOUNT_ERRORS_RO            0x00020 /* Remount fs ro on errors */
 973 #define EXT4_MOUNT_ERRORS_PANIC         0x00040 /* Panic on errors */
 974 #define EXT4_MOUNT_ERRORS_MASK          0x00070
 975 #define EXT4_MOUNT_MINIX_DF             0x00080 /* Mimics the Minix statfs */
 976 #define EXT4_MOUNT_NOLOAD               0x00100 /* Don't use existing journal*/
 977 #define EXT4_MOUNT_DATA_FLAGS           0x00C00 /* Mode for data writes: */
 978 #define EXT4_MOUNT_JOURNAL_DATA         0x00400 /* Write data to journal */
 979 #define EXT4_MOUNT_ORDERED_DATA         0x00800 /* Flush data before commit */
 980 #define EXT4_MOUNT_WRITEBACK_DATA       0x00C00 /* No data ordering */
 981 #define EXT4_MOUNT_UPDATE_JOURNAL       0x01000 /* Update the journal format */
 982 #define EXT4_MOUNT_NO_UID32             0x02000  /* Disable 32-bit UIDs */
 983 #define EXT4_MOUNT_XATTR_USER           0x04000 /* Extended user attributes */
 984 #define EXT4_MOUNT_POSIX_ACL            0x08000 /* POSIX Access Control Lists */
 985 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC     0x10000 /* No auto delalloc mapping */
 986 #define EXT4_MOUNT_BARRIER              0x20000 /* Use block barriers */
 987 #define EXT4_MOUNT_QUOTA                0x80000 /* Some quota option set */
 988 #define EXT4_MOUNT_USRQUOTA             0x100000 /* "old" user quota */
 989 #define EXT4_MOUNT_GRPQUOTA             0x200000 /* "old" group quota */
 990 #define EXT4_MOUNT_DIOREAD_NOLOCK       0x400000 /* Enable support for dio read nolocking */
 991 #define EXT4_MOUNT_JOURNAL_CHECKSUM     0x800000 /* Journal checksums */
 992 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT 0x1000000 /* Journal Async Commit */
 993 #define EXT4_MOUNT_DELALLOC             0x8000000 /* Delalloc support */
 994 #define EXT4_MOUNT_DATA_ERR_ABORT       0x10000000 /* Abort on file data write */
 995 #define EXT4_MOUNT_BLOCK_VALIDITY       0x20000000 /* Block validity checking */
 996 #define EXT4_MOUNT_DISCARD              0x40000000 /* Issue DISCARD requests */
 997 #define EXT4_MOUNT_INIT_INODE_TABLE     0x80000000 /* Initialize uninitialized itables */
 998
 999 /*
1000  * Mount flags set either automatically (could not be set by mount option)
1001  * based on per file system feature or property or in special cases such as
1002  * distinguishing between explicit mount option definition and default.
1003  */
1004 #define EXT4_MOUNT2_EXPLICIT_DELALLOC   0x00000001 /* User explicitly
1005                                                       specified delalloc */
1006 #define EXT4_MOUNT2_STD_GROUP_SIZE      0x00000002 /* We have standard group
1007                                                       size of blocksize * 8
1008                                                       blocks */
1009 #define EXT4_MOUNT2_HURD_COMPAT         0x00000004 /* Support HURD-castrated
1010                                                       file systems */
1011
1012 #define clear_opt(sb, opt)              EXT4_SB(sb)->s_mount_opt &= \
1013                                                 ~EXT4_MOUNT_##opt
1014 #define set_opt(sb, opt)                EXT4_SB(sb)->s_mount_opt |= \
1015                                                 EXT4_MOUNT_##opt
1016 #define test_opt(sb, opt)               (EXT4_SB(sb)->s_mount_opt & \
1017                                          EXT4_MOUNT_##opt)
1018
1019 #define clear_opt2(sb, opt)             EXT4_SB(sb)->s_mount_opt2 &= \
1020                                                 ~EXT4_MOUNT2_##opt
1021 #define set_opt2(sb, opt)               EXT4_SB(sb)->s_mount_opt2 |= \
1022                                                 EXT4_MOUNT2_##opt
1023 #define test_opt2(sb, opt)              (EXT4_SB(sb)->s_mount_opt2 & \
1024                                          EXT4_MOUNT2_##opt)
1025
1026 #define ext4_test_and_set_bit           __test_and_set_bit_le
1027 #define ext4_set_bit                    __set_bit_le
1028 #define ext4_set_bit_atomic             ext2_set_bit_atomic
1029 #define ext4_test_and_clear_bit         __test_and_clear_bit_le
1030 #define ext4_clear_bit                  __clear_bit_le
1031 #define ext4_clear_bit_atomic           ext2_clear_bit_atomic
1032 #define ext4_test_bit                   test_bit_le
1033 #define ext4_find_next_zero_bit         find_next_zero_bit_le
1034 #define ext4_find_next_bit              find_next_bit_le
1035
1036 extern void ext4_set_bits(void *bm, int cur, int len);
1037
1038 /*
1039  * Maximal mount counts between two filesystem checks
1040  */
1041 #define EXT4_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
1042 #define EXT4_DFL_CHECKINTERVAL          0       /* Don't use interval check */
1043
1044 /*
1045  * Behaviour when detecting errors
1046  */
1047 #define EXT4_ERRORS_CONTINUE            1       /* Continue execution */
1048 #define EXT4_ERRORS_RO                  2       /* Remount fs read-only */
1049 #define EXT4_ERRORS_PANIC               3       /* Panic */
1050 #define EXT4_ERRORS_DEFAULT             EXT4_ERRORS_CONTINUE
1051
1052 /* Metadata checksum algorithm codes */
1053 #define EXT4_CRC32C_CHKSUM              1
1054
1055 /*
1056  * Structure of the super block
1057  */
1058 struct ext4_super_block {
1059 /*00*/  __le32  s_inodes_count;         /* Inodes count */
1060         __le32  s_blocks_count_lo;      /* Blocks count */
1061         __le32  s_r_blocks_count_lo;    /* Reserved blocks count */
1062         __le32  s_free_blocks_count_lo; /* Free blocks count */
1063 /*10*/  __le32  s_free_inodes_count;    /* Free inodes count */
1064         __le32  s_first_data_block;     /* First Data Block */
1065         __le32  s_log_block_size;       /* Block size */
1066         __le32  s_log_cluster_size;     /* Allocation cluster size */
1067 /*20*/  __le32  s_blocks_per_group;     /* # Blocks per group */
1068         __le32  s_clusters_per_group;   /* # Clusters per group */
1069         __le32  s_inodes_per_group;     /* # Inodes per group */
1070         __le32  s_mtime;                /* Mount time */
1071 /*30*/  __le32  s_wtime;                /* Write time */
1072         __le16  s_mnt_count;            /* Mount count */
1073         __le16  s_max_mnt_count;        /* Maximal mount count */
1074         __le16  s_magic;                /* Magic signature */
1075         __le16  s_state;                /* File system state */
1076         __le16  s_errors;               /* Behaviour when detecting errors */
1077         __le16  s_minor_rev_level;      /* minor revision level */
1078 /*40*/  __le32  s_lastcheck;            /* time of last check */
1079         __le32  s_checkinterval;        /* max. time between checks */
1080         __le32  s_creator_os;           /* OS */
1081         __le32  s_rev_level;            /* Revision level */
1082 /*50*/  __le16  s_def_resuid;           /* Default uid for reserved blocks */
1083         __le16  s_def_resgid;           /* Default gid for reserved blocks */
1084         /*
1085          * These fields are for EXT4_DYNAMIC_REV superblocks only.
1086          *
1087          * Note: the difference between the compatible feature set and
1088          * the incompatible feature set is that if there is a bit set
1089          * in the incompatible feature set that the kernel doesn't
1090          * know about, it should refuse to mount the filesystem.
1091          *
1092          * e2fsck's requirements are more strict; if it doesn't know
1093          * about a feature in either the compatible or incompatible
1094          * feature set, it must abort and not try to meddle with
1095          * things it doesn't understand...
1096          */
1097         __le32  s_first_ino;            /* First non-reserved inode */
1098         __le16  s_inode_size;           /* size of inode structure */
1099         __le16  s_block_group_nr;       /* block group # of this superblock */
1100         __le32  s_feature_compat;       /* compatible feature set */
1101 /*60*/  __le32  s_feature_incompat;     /* incompatible feature set */
1102         __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
1103 /*68*/  __u8    s_uuid[16];             /* 128-bit uuid for volume */
1104 /*78*/  char    s_volume_name[16];      /* volume name */
1105 /*88*/  char    s_last_mounted[64];     /* directory where last mounted */
1106 /*C8*/  __le32  s_algorithm_usage_bitmap; /* For compression */
1107         /*
1108          * Performance hints.  Directory preallocation should only
1109          * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
1110          */
1111         __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
1112         __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
1113         __le16  s_reserved_gdt_blocks;  /* Per group desc for online growth */
1114         /*
1115          * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
1116          */
1117 /*D0*/  __u8    s_journal_uuid[16];     /* uuid of journal superblock */
1118 /*E0*/  __le32  s_journal_inum;         /* inode number of journal file */
1119         __le32  s_journal_dev;          /* device number of journal file */
1120         __le32  s_last_orphan;          /* start of list of inodes to delete */
1121         __le32  s_hash_seed[4];         /* HTREE hash seed */
1122         __u8    s_def_hash_version;     /* Default hash version to use */
1123         __u8    s_jnl_backup_type;
1124         __le16  s_desc_size;            /* size of group descriptor */
1125 /*100*/ __le32  s_default_mount_opts;
1126         __le32  s_first_meta_bg;        /* First metablock block group */
1127         __le32  s_mkfs_time;            /* When the filesystem was created */
1128         __le32  s_jnl_blocks[17];       /* Backup of the journal inode */
1129         /* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
1130 /*150*/ __le32  s_blocks_count_hi;      /* Blocks count */
1131         __le32  s_r_blocks_count_hi;    /* Reserved blocks count */
1132         __le32  s_free_blocks_count_hi; /* Free blocks count */
1133         __le16  s_min_extra_isize;      /* All inodes have at least # bytes */
1134         __le16  s_want_extra_isize;     /* New inodes should reserve # bytes */
1135         __le32  s_flags;                /* Miscellaneous flags */
1136         __le16  s_raid_stride;          /* RAID stride */
1137         __le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */
1138         __le64  s_mmp_block;            /* Block for multi-mount protection */
1139         __le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1140         __u8    s_log_groups_per_flex;  /* FLEX_BG group size */
1141         __u8    s_checksum_type;        /* metadata checksum algorithm used */
1142         __le16  s_reserved_pad;
1143         __le64  s_kbytes_written;       /* nr of lifetime kilobytes written */
1144         __le32  s_snapshot_inum;        /* Inode number of active snapshot */
1145         __le32  s_snapshot_id;          /* sequential ID of active snapshot */
1146         __le64  s_snapshot_r_blocks_count; /* reserved blocks for active
1147                                               snapshot's future use */
1148         __le32  s_snapshot_list;        /* inode number of the head of the
1149                                            on-disk snapshot list */
1150 #define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
1151         __le32  s_error_count;          /* number of fs errors */
1152         __le32  s_first_error_time;     /* first time an error happened */
1153         __le32  s_first_error_ino;      /* inode involved in first error */
1154         __le64  s_first_error_block;    /* block involved of first error */
1155         __u8    s_first_error_func[32]; /* function where the error happened */
1156         __le32  s_first_error_line;     /* line number where error happened */
1157         __le32  s_last_error_time;      /* most recent time of an error */
1158         __le32  s_last_error_ino;       /* inode involved in last error */
1159         __le32  s_last_error_line;      /* line number where error happened */
1160         __le64  s_last_error_block;     /* block involved of last error */
1161         __u8    s_last_error_func[32];  /* function where the error happened */
1162 #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
1163         __u8    s_mount_opts[64];
1164         __le32  s_usr_quota_inum;       /* inode for tracking user quota */
1165         __le32  s_grp_quota_inum;       /* inode for tracking group quota */
1166         __le32  s_overhead_clusters;    /* overhead blocks/clusters in fs */
1167         __le32  s_backup_bgs[2];        /* groups with sparse_super2 SBs */
1168         __le32  s_reserved[106];        /* Padding to the end of the block */
1169         __le32  s_checksum;             /* crc32c(superblock) */
1170 };
1171
1172 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1173
1174 #ifdef __KERNEL__
1175
1176 /*
1177  * run-time mount flags
1178  */
1179 #define EXT4_MF_MNTDIR_SAMPLED  0x0001
1180 #define EXT4_MF_FS_ABORTED      0x0002  /* Fatal error detected */
1181
1182 /* Number of quota types we support */
1183 #define EXT4_MAXQUOTAS 2
1184
1185 /*
1186  * fourth extended-fs super-block data in memory
1187  */
1188 struct ext4_sb_info {
1189         unsigned long s_desc_size;      /* Size of a group descriptor in bytes */
1190         unsigned long s_inodes_per_block;/* Number of inodes per block */
1191         unsigned long s_blocks_per_group;/* Number of blocks in a group */
1192         unsigned long s_clusters_per_group; /* Number of clusters in a group */
1193         unsigned long s_inodes_per_group;/* Number of inodes in a group */
1194         unsigned long s_itb_per_group;  /* Number of inode table blocks per group */
1195         unsigned long s_gdb_count;      /* Number of group descriptor blocks */
1196         unsigned long s_desc_per_block; /* Number of group descriptors per block */
1197         ext4_group_t s_groups_count;    /* Number of groups in the fs */
1198         ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1199         unsigned long s_overhead;  /* # of fs overhead clusters */
1200         unsigned int s_cluster_ratio;   /* Number of blocks per cluster */
1201         unsigned int s_cluster_bits;    /* log2 of s_cluster_ratio */
1202         loff_t s_bitmap_maxbytes;       /* max bytes for bitmap files */
1203         struct buffer_head * s_sbh;     /* Buffer containing the super block */
1204         struct ext4_super_block *s_es;  /* Pointer to the super block in the buffer */
1205         struct buffer_head **s_group_desc;
1206         unsigned int s_mount_opt;
1207         unsigned int s_mount_opt2;
1208         unsigned int s_mount_flags;
1209         unsigned int s_def_mount_opt;
1210         ext4_fsblk_t s_sb_block;
1211         atomic64_t s_resv_clusters;
1212         kuid_t s_resuid;
1213         kgid_t s_resgid;
1214         unsigned short s_mount_state;
1215         unsigned short s_pad;
1216         int s_addr_per_block_bits;
1217         int s_desc_per_block_bits;
1218         int s_inode_size;
1219         int s_first_ino;
1220         unsigned int s_inode_readahead_blks;
1221         unsigned int s_inode_goal;
1222         spinlock_t s_next_gen_lock;
1223         u32 s_next_generation;
1224         u32 s_hash_seed[4];
1225         int s_def_hash_version;
1226         int s_hash_unsigned;    /* 3 if hash should be signed, 0 if not */
1227         struct percpu_counter s_freeclusters_counter;
1228         struct percpu_counter s_freeinodes_counter;
1229         struct percpu_counter s_dirs_counter;
1230         struct percpu_counter s_dirtyclusters_counter;
1231         struct blockgroup_lock *s_blockgroup_lock;
1232         struct proc_dir_entry *s_proc;
1233         struct kobject s_kobj;
1234         struct completion s_kobj_unregister;
1235         struct super_block *s_sb;
1236
1237         /* Journaling */
1238         struct journal_s *s_journal;
1239         struct list_head s_orphan;
1240         struct mutex s_orphan_lock;
1241         unsigned long s_resize_flags;           /* Flags indicating if there
1242                                                    is a resizer */
1243         unsigned long s_commit_interval;
1244         u32 s_max_batch_time;
1245         u32 s_min_batch_time;
1246         struct block_device *journal_bdev;
1247 #ifdef CONFIG_QUOTA
1248         char *s_qf_names[EXT4_MAXQUOTAS];       /* Names of quota files with journalled quota */
1249         int s_jquota_fmt;                       /* Format of quota to use */
1250 #endif
1251         unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1252         struct rb_root system_blks;
1253
1254 #ifdef EXTENTS_STATS
1255         /* ext4 extents stats */
1256         unsigned long s_ext_min;
1257         unsigned long s_ext_max;
1258         unsigned long s_depth_max;
1259         spinlock_t s_ext_stats_lock;
1260         unsigned long s_ext_blocks;
1261         unsigned long s_ext_extents;
1262 #endif
1263
1264         /* for buddy allocator */
1265         struct ext4_group_info ***s_group_info;
1266         struct inode *s_buddy_cache;
1267         spinlock_t s_md_lock;
1268         unsigned short *s_mb_offsets;
1269         unsigned int *s_mb_maxs;
1270         unsigned int s_group_info_size;
1271
1272         /* tunables */
1273         unsigned long s_stripe;
1274         unsigned int s_mb_stream_request;
1275         unsigned int s_mb_max_to_scan;
1276         unsigned int s_mb_min_to_scan;
1277         unsigned int s_mb_stats;
1278         unsigned int s_mb_order2_reqs;
1279         unsigned int s_mb_group_prealloc;
1280         unsigned int s_max_dir_size_kb;
1281         /* where last allocation was done - for stream allocation */
1282         unsigned long s_mb_last_group;
1283         unsigned long s_mb_last_start;
1284
1285         /* stats for buddy allocator */
1286         atomic_t s_bal_reqs;    /* number of reqs with len > 1 */
1287         atomic_t s_bal_success; /* we found long enough chunks */
1288         atomic_t s_bal_allocated;       /* in blocks */
1289         atomic_t s_bal_ex_scanned;      /* total extents scanned */
1290         atomic_t s_bal_goals;   /* goal hits */
1291         atomic_t s_bal_breaks;  /* too long searches */
1292         atomic_t s_bal_2orders; /* 2^order hits */
1293         spinlock_t s_bal_lock;
1294         unsigned long s_mb_buddies_generated;
1295         unsigned long long s_mb_generation_time;
1296         atomic_t s_mb_lost_chunks;
1297         atomic_t s_mb_preallocated;
1298         atomic_t s_mb_discarded;
1299         atomic_t s_lock_busy;
1300
1301         /* locality groups */
1302         struct ext4_locality_group __percpu *s_locality_groups;
1303
1304         /* for write statistics */
1305         unsigned long s_sectors_written_start;
1306         u64 s_kbytes_written;
1307
1308         /* the size of zero-out chunk */
1309         unsigned int s_extent_max_zeroout_kb;
1310
1311         unsigned int s_log_groups_per_flex;
1312         struct flex_groups *s_flex_groups;
1313         ext4_group_t s_flex_groups_allocated;
1314
1315         /* workqueue for reserved extent conversions (buffered io) */
1316         struct workqueue_struct *rsv_conversion_wq;
1317
1318         /* timer for periodic error stats printing */
1319         struct timer_list s_err_report;
1320
1321         /* Lazy inode table initialization info */
1322         struct ext4_li_request *s_li_request;
1323         /* Wait multiplier for lazy initialization thread */
1324         unsigned int s_li_wait_mult;
1325
1326         /* Kernel thread for multiple mount protection */
1327         struct task_struct *s_mmp_tsk;
1328
1329         /* record the last minlen when FITRIM is called. */
1330         atomic_t s_last_trim_minblks;
1331
1332         /* Reference to checksum algorithm driver via cryptoapi */
1333         struct crypto_shash *s_chksum_driver;
1334
1335         /* Precomputed FS UUID checksum for seeding other checksums */
1336         __u32 s_csum_seed;
1337
1338         /* Reclaim extents from extent status tree */
1339         struct shrinker s_es_shrinker;
1340         struct list_head s_es_lru;
1341         struct ext4_es_stats s_es_stats;
1342         struct mb_cache *s_mb_cache;
1343         spinlock_t s_es_lru_lock ____cacheline_aligned_in_smp;
1344
1345         /* Ratelimit ext4 messages. */
1346         struct ratelimit_state s_err_ratelimit_state;
1347         struct ratelimit_state s_warning_ratelimit_state;
1348         struct ratelimit_state s_msg_ratelimit_state;
1349 };
1350
1351 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1352 {
1353         return sb->s_fs_info;
1354 }
1355 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1356 {
1357         return container_of(inode, struct ext4_inode_info, vfs_inode);
1358 }
1359
1360 static inline struct timespec ext4_current_time(struct inode *inode)
1361 {
1362         return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1363                 current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1364 }
1365
1366 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1367 {
1368         return ino == EXT4_ROOT_INO ||
1369                 ino == EXT4_USR_QUOTA_INO ||
1370                 ino == EXT4_GRP_QUOTA_INO ||
1371                 ino == EXT4_BOOT_LOADER_INO ||
1372                 ino == EXT4_JOURNAL_INO ||
1373                 ino == EXT4_RESIZE_INO ||
1374                 (ino >= EXT4_FIRST_INO(sb) &&
1375                  ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1376 }
1377
1378 static inline void ext4_set_io_unwritten_flag(struct inode *inode,
1379                                               struct ext4_io_end *io_end)
1380 {
1381         if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
1382                 io_end->flag |= EXT4_IO_END_UNWRITTEN;
1383                 atomic_inc(&EXT4_I(inode)->i_unwritten);
1384         }
1385 }
1386
1387 static inline ext4_io_end_t *ext4_inode_aio(struct inode *inode)
1388 {
1389         return inode->i_private;
1390 }
1391
1392 static inline void ext4_inode_aio_set(struct inode *inode, ext4_io_end_t *io)
1393 {
1394         inode->i_private = io;
1395 }
1396
1397 /*
1398  * Inode dynamic state flags
1399  */
1400 enum {
1401         EXT4_STATE_JDATA,               /* journaled data exists */
1402         EXT4_STATE_NEW,                 /* inode is newly created */
1403         EXT4_STATE_XATTR,               /* has in-inode xattrs */
1404         EXT4_STATE_NO_EXPAND,           /* No space for expansion */
1405         EXT4_STATE_DA_ALLOC_CLOSE,      /* Alloc DA blks on close */
1406         EXT4_STATE_EXT_MIGRATE,         /* Inode is migrating */
1407         EXT4_STATE_DIO_UNWRITTEN,       /* need convert on dio done*/
1408         EXT4_STATE_NEWENTRY,            /* File just added to dir */
1409         EXT4_STATE_DIOREAD_LOCK,        /* Disable support for dio read
1410                                            nolocking */
1411         EXT4_STATE_MAY_INLINE_DATA,     /* may have in-inode data */
1412         EXT4_STATE_ORDERED_MODE,        /* data=ordered mode */
1413         EXT4_STATE_EXT_PRECACHED,       /* extents have been precached */
1414 };
1415
1416 #define EXT4_INODE_BIT_FNS(name, field, offset)                         \
1417 static inline int ext4_test_inode_##name(struct inode *inode, int bit)  \
1418 {                                                                       \
1419         return test_bit(bit + (offset), &EXT4_I(inode)->i_##field);     \
1420 }                                                                       \
1421 static inline void ext4_set_inode_##name(struct inode *inode, int bit)  \
1422 {                                                                       \
1423         set_bit(bit + (offset), &EXT4_I(inode)->i_##field);             \
1424 }                                                                       \
1425 static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1426 {                                                                       \
1427         clear_bit(bit + (offset), &EXT4_I(inode)->i_##field);           \
1428 }
1429
1430 /* Add these declarations here only so that these functions can be
1431  * found by name.  Otherwise, they are very hard to locate. */
1432 static inline int ext4_test_inode_flag(struct inode *inode, int bit);
1433 static inline void ext4_set_inode_flag(struct inode *inode, int bit);
1434 static inline void ext4_clear_inode_flag(struct inode *inode, int bit);
1435 EXT4_INODE_BIT_FNS(flag, flags, 0)
1436
1437 /* Add these declarations here only so that these functions can be
1438  * found by name.  Otherwise, they are very hard to locate. */
1439 static inline int ext4_test_inode_state(struct inode *inode, int bit);
1440 static inline void ext4_set_inode_state(struct inode *inode, int bit);
1441 static inline void ext4_clear_inode_state(struct inode *inode, int bit);
1442 #if (BITS_PER_LONG < 64)
1443 EXT4_INODE_BIT_FNS(state, state_flags, 0)
1444
1445 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1446 {
1447         (ei)->i_state_flags = 0;
1448 }
1449 #else
1450 EXT4_INODE_BIT_FNS(state, flags, 32)
1451
1452 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1453 {
1454         /* We depend on the fact that callers will set i_flags */
1455 }
1456 #endif
1457 #else
1458 /* Assume that user mode programs are passing in an ext4fs superblock, not
1459  * a kernel struct super_block.  This will allow us to call the feature-test
1460  * macros from user land. */
1461 #define EXT4_SB(sb)     (sb)
1462 #endif
1463
1464 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1465
1466 /*
1467  * Codes for operating systems
1468  */
1469 #define EXT4_OS_LINUX           0
1470 #define EXT4_OS_HURD            1
1471 #define EXT4_OS_MASIX           2
1472 #define EXT4_OS_FREEBSD         3
1473 #define EXT4_OS_LITES           4
1474
1475 /*
1476  * Revision levels
1477  */
1478 #define EXT4_GOOD_OLD_REV       0       /* The good old (original) format */
1479 #define EXT4_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
1480
1481 #define EXT4_CURRENT_REV        EXT4_GOOD_OLD_REV
1482 #define EXT4_MAX_SUPP_REV       EXT4_DYNAMIC_REV
1483
1484 #define EXT4_GOOD_OLD_INODE_SIZE 128
1485
1486 /*
1487  * Feature set definitions
1488  */
1489
1490 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)                        \
1491         ((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1492 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
1493         ((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1494 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)                      \
1495         ((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1496 #define EXT4_SET_COMPAT_FEATURE(sb,mask)                        \
1497         EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1498 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)                     \
1499         EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1500 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)                      \
1501         EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1502 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)                      \
1503         EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1504 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
1505         EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1506 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
1507         EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1508
1509 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC        0x0001
1510 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES       0x0002
1511 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL         0x0004
1512 #define EXT4_FEATURE_COMPAT_EXT_ATTR            0x0008
1513 #define EXT4_FEATURE_COMPAT_RESIZE_INODE        0x0010
1514 #define EXT4_FEATURE_COMPAT_DIR_INDEX           0x0020
1515 #define EXT4_FEATURE_COMPAT_SPARSE_SUPER2       0x0200
1516
1517 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
1518 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
1519 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
1520 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1521 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM         0x0010
1522 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK        0x0020
1523 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE      0x0040
1524 #define EXT4_FEATURE_RO_COMPAT_QUOTA            0x0100
1525 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC         0x0200
1526 /*
1527  * METADATA_CSUM also enables group descriptor checksums (GDT_CSUM).  When
1528  * METADATA_CSUM is set, group descriptor checksums use the same algorithm as
1529  * all other data structures' checksums.  However, the METADATA_CSUM and
1530  * GDT_CSUM bits are mutually exclusive.
1531  */
1532 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM    0x0400
1533
1534 #define EXT4_FEATURE_INCOMPAT_COMPRESSION       0x0001
1535 #define EXT4_FEATURE_INCOMPAT_FILETYPE          0x0002
1536 #define EXT4_FEATURE_INCOMPAT_RECOVER           0x0004 /* Needs recovery */
1537 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008 /* Journal device */
1538 #define EXT4_FEATURE_INCOMPAT_META_BG           0x0010
1539 #define EXT4_FEATURE_INCOMPAT_EXTENTS           0x0040 /* extents support */
1540 #define EXT4_FEATURE_INCOMPAT_64BIT             0x0080
1541 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1542 #define EXT4_FEATURE_INCOMPAT_FLEX_BG           0x0200
1543 #define EXT4_FEATURE_INCOMPAT_EA_INODE          0x0400 /* EA in inode */
1544 #define EXT4_FEATURE_INCOMPAT_DIRDATA           0x1000 /* data in dirent */
1545 #define EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM  0x2000 /* use crc32c for bg */
1546 #define EXT4_FEATURE_INCOMPAT_LARGEDIR          0x4000 /* >2GB or 3-lvl htree */
1547 #define EXT4_FEATURE_INCOMPAT_INLINE_DATA       0x8000 /* data in inode */
1548
1549 #define EXT2_FEATURE_COMPAT_SUPP        EXT4_FEATURE_COMPAT_EXT_ATTR
1550 #define EXT2_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1551                                          EXT4_FEATURE_INCOMPAT_META_BG)
1552 #define EXT2_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1553                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1554                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1555
1556 #define EXT3_FEATURE_COMPAT_SUPP        EXT4_FEATURE_COMPAT_EXT_ATTR
1557 #define EXT3_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1558                                          EXT4_FEATURE_INCOMPAT_RECOVER| \
1559                                          EXT4_FEATURE_INCOMPAT_META_BG)
1560 #define EXT3_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1561                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1562                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1563
1564 #define EXT4_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
1565 #define EXT4_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1566                                          EXT4_FEATURE_INCOMPAT_RECOVER| \
1567                                          EXT4_FEATURE_INCOMPAT_META_BG| \
1568                                          EXT4_FEATURE_INCOMPAT_EXTENTS| \
1569                                          EXT4_FEATURE_INCOMPAT_64BIT| \
1570                                          EXT4_FEATURE_INCOMPAT_FLEX_BG| \
1571                                          EXT4_FEATURE_INCOMPAT_MMP |    \
1572                                          EXT4_FEATURE_INCOMPAT_INLINE_DATA)
1573 #define EXT4_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1574                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1575                                          EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1576                                          EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1577                                          EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1578                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1579                                          EXT4_FEATURE_RO_COMPAT_HUGE_FILE |\
1580                                          EXT4_FEATURE_RO_COMPAT_BIGALLOC |\
1581                                          EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
1582                                          EXT4_FEATURE_RO_COMPAT_QUOTA)
1583
1584 /*
1585  * Default values for user and/or group using reserved blocks
1586  */
1587 #define EXT4_DEF_RESUID         0
1588 #define EXT4_DEF_RESGID         0
1589
1590 #define EXT4_DEF_INODE_READAHEAD_BLKS   32
1591
1592 /*
1593  * Default mount options
1594  */
1595 #define EXT4_DEFM_DEBUG         0x0001
1596 #define EXT4_DEFM_BSDGROUPS     0x0002
1597 #define EXT4_DEFM_XATTR_USER    0x0004
1598 #define EXT4_DEFM_ACL           0x0008
1599 #define EXT4_DEFM_UID16         0x0010
1600 #define EXT4_DEFM_JMODE         0x0060
1601 #define EXT4_DEFM_JMODE_DATA    0x0020
1602 #define EXT4_DEFM_JMODE_ORDERED 0x0040
1603 #define EXT4_DEFM_JMODE_WBACK   0x0060
1604 #define EXT4_DEFM_NOBARRIER     0x0100
1605 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
1606 #define EXT4_DEFM_DISCARD       0x0400
1607 #define EXT4_DEFM_NODELALLOC    0x0800
1608
1609 /*
1610  * Default journal batch times
1611  */
1612 #define EXT4_DEF_MIN_BATCH_TIME 0
1613 #define EXT4_DEF_MAX_BATCH_TIME 15000 /* 15ms */
1614
1615 /*
1616  * Minimum number of groups in a flexgroup before we separate out
1617  * directories into the first block group of a flexgroup
1618  */
1619 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME 4
1620
1621 /*
1622  * Structure of a directory entry
1623  */
1624 #define EXT4_NAME_LEN 255
1625
1626 struct ext4_dir_entry {
1627         __le32  inode;                  /* Inode number */
1628         __le16  rec_len;                /* Directory entry length */
1629         __le16  name_len;               /* Name length */
1630         char    name[EXT4_NAME_LEN];    /* File name */
1631 };
1632
1633 /*
1634  * The new version of the directory entry.  Since EXT4 structures are
1635  * stored in intel byte order, and the name_len field could never be
1636  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1637  * file_type field.
1638  */
1639 struct ext4_dir_entry_2 {
1640         __le32  inode;                  /* Inode number */
1641         __le16  rec_len;                /* Directory entry length */
1642         __u8    name_len;               /* Name length */
1643         __u8    file_type;
1644         char    name[EXT4_NAME_LEN];    /* File name */
1645 };
1646
1647 /*
1648  * This is a bogus directory entry at the end of each leaf block that
1649  * records checksums.
1650  */
1651 struct ext4_dir_entry_tail {
1652         __le32  det_reserved_zero1;     /* Pretend to be unused */
1653         __le16  det_rec_len;            /* 12 */
1654         __u8    det_reserved_zero2;     /* Zero name length */
1655         __u8    det_reserved_ft;        /* 0xDE, fake file type */
1656         __le32  det_checksum;           /* crc32c(uuid+inum+dirblock) */
1657 };
1658
1659 #define EXT4_DIRENT_TAIL(block, blocksize) \
1660         ((struct ext4_dir_entry_tail *)(((void *)(block)) + \
1661                                         ((blocksize) - \
1662                                          sizeof(struct ext4_dir_entry_tail))))
1663
1664 /*
1665  * Ext4 directory file types.  Only the low 3 bits are used.  The
1666  * other bits are reserved for now.
1667  */
1668 #define EXT4_FT_UNKNOWN         0
1669 #define EXT4_FT_REG_FILE        1
1670 #define EXT4_FT_DIR             2
1671 #define EXT4_FT_CHRDEV          3
1672 #define EXT4_FT_BLKDEV          4
1673 #define EXT4_FT_FIFO            5
1674 #define EXT4_FT_SOCK            6
1675 #define EXT4_FT_SYMLINK         7
1676
1677 #define EXT4_FT_MAX             8
1678
1679 #define EXT4_FT_DIR_CSUM        0xDE
1680
1681 /*
1682  * EXT4_DIR_PAD defines the directory entries boundaries
1683  *
1684  * NOTE: It must be a multiple of 4
1685  */
1686 #define EXT4_DIR_PAD                    4
1687 #define EXT4_DIR_ROUND                  (EXT4_DIR_PAD - 1)
1688 #define EXT4_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT4_DIR_ROUND) & \
1689                                          ~EXT4_DIR_ROUND)
1690 #define EXT4_MAX_REC_LEN                ((1<<16)-1)
1691
1692 /*
1693  * If we ever get support for fs block sizes > page_size, we'll need
1694  * to remove the #if statements in the next two functions...
1695  */
1696 static inline unsigned int
1697 ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
1698 {
1699         unsigned len = le16_to_cpu(dlen);
1700
1701 #if (PAGE_CACHE_SIZE >= 65536)
1702         if (len == EXT4_MAX_REC_LEN || len == 0)
1703                 return blocksize;
1704         return (len & 65532) | ((len & 3) << 16);
1705 #else
1706         return len;
1707 #endif
1708 }
1709
1710 static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
1711 {
1712         if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
1713                 BUG();
1714 #if (PAGE_CACHE_SIZE >= 65536)
1715         if (len < 65536)
1716                 return cpu_to_le16(len);
1717         if (len == blocksize) {
1718                 if (blocksize == 65536)
1719                         return cpu_to_le16(EXT4_MAX_REC_LEN);
1720                 else
1721                         return cpu_to_le16(0);
1722         }
1723         return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
1724 #else
1725         return cpu_to_le16(len);
1726 #endif
1727 }
1728
1729 /*
1730  * Hash Tree Directory indexing
1731  * (c) Daniel Phillips, 2001
1732  */
1733
1734 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1735                                       EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1736                     ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
1737 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1738 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1739
1740 /* Legal values for the dx_root hash_version field: */
1741
1742 #define DX_HASH_LEGACY          0
1743 #define DX_HASH_HALF_MD4        1
1744 #define DX_HASH_TEA             2
1745 #define DX_HASH_LEGACY_UNSIGNED 3
1746 #define DX_HASH_HALF_MD4_UNSIGNED       4
1747 #define DX_HASH_TEA_UNSIGNED            5
1748
1749 static inline u32 ext4_chksum(struct ext4_sb_info *sbi, u32 crc,
1750                               const void *address, unsigned int length)
1751 {
1752         struct {
1753                 struct shash_desc shash;
1754                 char ctx[4];
1755         } desc;
1756         int err;
1757
1758         BUG_ON(crypto_shash_descsize(sbi->s_chksum_driver)!=sizeof(desc.ctx));
1759
1760         desc.shash.tfm = sbi->s_chksum_driver;
1761         desc.shash.flags = 0;
1762         *(u32 *)desc.ctx = crc;
1763
1764         err = crypto_shash_update(&desc.shash, address, length);
1765         BUG_ON(err);
1766
1767         return *(u32 *)desc.ctx;
1768 }
1769
1770 #ifdef __KERNEL__
1771
1772 /* hash info structure used by the directory hash */
1773 struct dx_hash_info
1774 {
1775         u32             hash;
1776         u32             minor_hash;
1777         int             hash_version;
1778         u32             *seed;
1779 };
1780
1781
1782 /* 32 and 64 bit signed EOF for dx directories */
1783 #define EXT4_HTREE_EOF_32BIT   ((1UL  << (32 - 1)) - 1)
1784 #define EXT4_HTREE_EOF_64BIT   ((1ULL << (64 - 1)) - 1)
1785
1786
1787 /*
1788  * Control parameters used by ext4_htree_next_block
1789  */
1790 #define HASH_NB_ALWAYS          1
1791
1792
1793 /*
1794  * Describe an inode's exact location on disk and in memory
1795  */
1796 struct ext4_iloc
1797 {
1798         struct buffer_head *bh;
1799         unsigned long offset;
1800         ext4_group_t block_group;
1801 };
1802
1803 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1804 {
1805         return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1806 }
1807
1808 /*
1809  * This structure is stuffed into the struct file's private_data field
1810  * for directories.  It is where we put information so that we can do
1811  * readdir operations in hash tree order.
1812  */
1813 struct dir_private_info {
1814         struct rb_root  root;
1815         struct rb_node  *curr_node;
1816         struct fname    *extra_fname;
1817         loff_t          last_pos;
1818         __u32           curr_hash;
1819         __u32           curr_minor_hash;
1820         __u32           next_hash;
1821 };
1822
1823 /* calculate the first block number of the group */
1824 static inline ext4_fsblk_t
1825 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1826 {
1827         return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1828                 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1829 }
1830
1831 /*
1832  * Special error return code only used by dx_probe() and its callers.
1833  */
1834 #define ERR_BAD_DX_DIR  (-(MAX_ERRNO - 1))
1835
1836 /*
1837  * Timeout and state flag for lazy initialization inode thread.
1838  */
1839 #define EXT4_DEF_LI_WAIT_MULT                   10
1840 #define EXT4_DEF_LI_MAX_START_DELAY             5
1841 #define EXT4_LAZYINIT_QUIT                      0x0001
1842 #define EXT4_LAZYINIT_RUNNING                   0x0002
1843
1844 /*
1845  * Lazy inode table initialization info
1846  */
1847 struct ext4_lazy_init {
1848         unsigned long           li_state;
1849         struct list_head        li_request_list;
1850         struct mutex            li_list_mtx;
1851 };
1852
1853 struct ext4_li_request {
1854         struct super_block      *lr_super;
1855         struct ext4_sb_info     *lr_sbi;
1856         ext4_group_t            lr_next_group;
1857         struct list_head        lr_request;
1858         unsigned long           lr_next_sched;
1859         unsigned long           lr_timeout;
1860 };
1861
1862 struct ext4_features {
1863         struct kobject f_kobj;
1864         struct completion f_kobj_unregister;
1865 };
1866
1867 /*
1868  * This structure will be used for multiple mount protection. It will be
1869  * written into the block number saved in the s_mmp_block field in the
1870  * superblock. Programs that check MMP should assume that if
1871  * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
1872  * to use the filesystem, regardless of how old the timestamp is.
1873  */
1874 #define EXT4_MMP_MAGIC     0x004D4D50U /* ASCII for MMP */
1875 #define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
1876 #define EXT4_MMP_SEQ_FSCK  0xE24D4D50U /* mmp_seq value when being fscked */
1877 #define EXT4_MMP_SEQ_MAX   0xE24D4D4FU /* maximum valid mmp_seq value */
1878
1879 struct mmp_struct {
1880         __le32  mmp_magic;              /* Magic number for MMP */
1881         __le32  mmp_seq;                /* Sequence no. updated periodically */
1882
1883         /*
1884          * mmp_time, mmp_nodename & mmp_bdevname are only used for information
1885          * purposes and do not affect the correctness of the algorithm
1886          */
1887         __le64  mmp_time;               /* Time last updated */
1888         char    mmp_nodename[64];       /* Node which last updated MMP block */
1889         char    mmp_bdevname[32];       /* Bdev which last updated MMP block */
1890
1891         /*
1892          * mmp_check_interval is used to verify if the MMP block has been
1893          * updated on the block device. The value is updated based on the
1894          * maximum time to write the MMP block during an update cycle.
1895          */
1896         __le16  mmp_check_interval;
1897
1898         __le16  mmp_pad1;
1899         __le32  mmp_pad2[226];
1900         __le32  mmp_checksum;           /* crc32c(uuid+mmp_block) */
1901 };
1902
1903 /* arguments passed to the mmp thread */
1904 struct mmpd_data {
1905         struct buffer_head *bh; /* bh from initial read_mmp_block() */
1906         struct super_block *sb;  /* super block of the fs */
1907 };
1908
1909 /*
1910  * Check interval multiplier
1911  * The MMP block is written every update interval and initially checked every
1912  * update interval x the multiplier (the value is then adapted based on the
1913  * write latency). The reason is that writes can be delayed under load and we
1914  * don't want readers to incorrectly assume that the filesystem is no longer
1915  * in use.
1916  */
1917 #define EXT4_MMP_CHECK_MULT             2UL
1918
1919 /*
1920  * Minimum interval for MMP checking in seconds.
1921  */
1922 #define EXT4_MMP_MIN_CHECK_INTERVAL     5UL
1923
1924 /*
1925  * Maximum interval for MMP checking in seconds.
1926  */
1927 #define EXT4_MMP_MAX_CHECK_INTERVAL     300UL
1928
1929 /*
1930  * Function prototypes
1931  */
1932
1933 /*
1934  * Ok, these declarations are also in <linux/kernel.h> but none of the
1935  * ext4 source programs needs to include it so they are duplicated here.
1936  */
1937 # define NORET_TYPE     /**/
1938 # define ATTRIB_NORET   __attribute__((noreturn))
1939 # define NORET_AND      noreturn,
1940
1941 /* bitmap.c */
1942 extern unsigned int ext4_count_free(char *bitmap, unsigned numchars);
1943 void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1944                                 struct ext4_group_desc *gdp,
1945                                 struct buffer_head *bh, int sz);
1946 int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1947                                   struct ext4_group_desc *gdp,
1948                                   struct buffer_head *bh, int sz);
1949 void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
1950                                 struct ext4_group_desc *gdp,
1951                                 struct buffer_head *bh);
1952 int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
1953                                   struct ext4_group_desc *gdp,
1954                                   struct buffer_head *bh);
1955
1956 /* balloc.c */
1957 extern void ext4_get_group_no_and_offset(struct super_block *sb,
1958                                          ext4_fsblk_t blocknr,
1959                                          ext4_group_t *blockgrpp,
1960                                          ext4_grpblk_t *offsetp);
1961 extern ext4_group_t ext4_get_group_number(struct super_block *sb,
1962                                           ext4_fsblk_t block);
1963
1964 extern unsigned int ext4_block_group(struct super_block *sb,
1965                         ext4_fsblk_t blocknr);
1966 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1967                         ext4_fsblk_t blocknr);
1968 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1969 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1970                         ext4_group_t group);
1971 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1972                                          ext4_fsblk_t goal,
1973                                          unsigned int flags,
1974                                          unsigned long *count,
1975                                          int *errp);
1976 extern int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
1977                                     s64 nclusters, unsigned int flags);
1978 extern ext4_fsblk_t ext4_count_free_clusters(struct super_block *);
1979 extern void ext4_check_blocks_bitmap(struct super_block *);
1980 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1981                                                     ext4_group_t block_group,
1982                                                     struct buffer_head ** bh);
1983 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1984
1985 extern struct buffer_head *ext4_read_block_bitmap_nowait(struct super_block *sb,
1986                                                 ext4_group_t block_group);
1987 extern int ext4_wait_block_bitmap(struct super_block *sb,
1988                                   ext4_group_t block_group,
1989                                   struct buffer_head *bh);
1990 extern struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1991                                                   ext4_group_t block_group);
1992 extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
1993                                               ext4_group_t block_group,
1994                                               struct ext4_group_desc *gdp);
1995 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
1996
1997 /* dir.c */
1998 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
1999                                   struct file *,
2000                                   struct ext4_dir_entry_2 *,
2001                                   struct buffer_head *, char *, int,
2002                                   unsigned int);
2003 #define ext4_check_dir_entry(dir, filp, de, bh, buf, size, offset)      \
2004         unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
2005                                         (de), (bh), (buf), (size), (offset)))
2006 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
2007                                     __u32 minor_hash,
2008                                     struct ext4_dir_entry_2 *dirent);
2009 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
2010 extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
2011                              struct buffer_head *bh,
2012                              void *buf, int buf_size,
2013                              const char *name, int namelen,
2014                              struct ext4_dir_entry_2 **dest_de);
2015 void ext4_insert_dentry(struct inode *inode,
2016                         struct ext4_dir_entry_2 *de,
2017                         int buf_size,
2018                         const char *name, int namelen);
2019 static inline void ext4_update_dx_flag(struct inode *inode)
2020 {
2021         if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
2022                                      EXT4_FEATURE_COMPAT_DIR_INDEX))
2023                 ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
2024 }
2025 static unsigned char ext4_filetype_table[] = {
2026         DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
2027 };
2028
2029 static inline  unsigned char get_dtype(struct super_block *sb, int filetype)
2030 {
2031         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE) ||
2032             (filetype >= EXT4_FT_MAX))
2033                 return DT_UNKNOWN;
2034
2035         return ext4_filetype_table[filetype];
2036 }
2037 extern int ext4_check_all_de(struct inode *dir, struct buffer_head *bh,
2038                              void *buf, int buf_size);
2039
2040 /* fsync.c */
2041 extern int ext4_sync_file(struct file *, loff_t, loff_t, int);
2042
2043 /* hash.c */
2044 extern int ext4fs_dirhash(const char *name, int len, struct
2045                           dx_hash_info *hinfo);
2046
2047 /* ialloc.c */
2048 extern struct inode *__ext4_new_inode(handle_t *, struct inode *, umode_t,
2049                                       const struct qstr *qstr, __u32 goal,
2050                                       uid_t *owner, int handle_type,
2051                                       unsigned int line_no, int nblocks);
2052
2053 #define ext4_new_inode(handle, dir, mode, qstr, goal, owner) \
2054         __ext4_new_inode((handle), (dir), (mode), (qstr), (goal), (owner), \
2055                          0, 0, 0)
2056 #define ext4_new_inode_start_handle(dir, mode, qstr, goal, owner, \
2057                                     type, nblocks)                  \
2058         __ext4_new_inode(NULL, (dir), (mode), (qstr), (goal), (owner), \
2059                          (type), __LINE__, (nblocks))
2060
2061
2062 extern void ext4_free_inode(handle_t *, struct inode *);
2063 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
2064 extern unsigned long ext4_count_free_inodes(struct super_block *);
2065 extern unsigned long ext4_count_dirs(struct super_block *);
2066 extern void ext4_check_inodes_bitmap(struct super_block *);
2067 extern void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
2068 extern int ext4_init_inode_table(struct super_block *sb,
2069                                  ext4_group_t group, int barrier);
2070 extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
2071
2072 /* mballoc.c */
2073 extern long ext4_mb_stats;
2074 extern long ext4_mb_max_to_scan;
2075 extern int ext4_mb_init(struct super_block *);
2076 extern int ext4_mb_release(struct super_block *);
2077 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
2078                                 struct ext4_allocation_request *, int *);
2079 extern int ext4_mb_reserve_blocks(struct super_block *, int);
2080 extern void ext4_discard_preallocations(struct inode *);
2081 extern int __init ext4_init_mballoc(void);
2082 extern void ext4_exit_mballoc(void);
2083 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
2084                              struct buffer_head *bh, ext4_fsblk_t block,
2085                              unsigned long count, int flags);
2086 extern int ext4_mb_alloc_groupinfo(struct super_block *sb,
2087                                    ext4_group_t ngroups);
2088 extern int ext4_mb_add_groupinfo(struct super_block *sb,
2089                 ext4_group_t i, struct ext4_group_desc *desc);
2090 extern int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
2091                                 ext4_fsblk_t block, unsigned long count);
2092 extern int ext4_trim_fs(struct super_block *, struct fstrim_range *);
2093
2094 /* inode.c */
2095 struct buffer_head *ext4_getblk(handle_t *, struct inode *, ext4_lblk_t, int);
2096 struct buffer_head *ext4_bread(handle_t *, struct inode *, ext4_lblk_t, int);
2097 int ext4_get_block_write(struct inode *inode, sector_t iblock,
2098                          struct buffer_head *bh_result, int create);
2099 int ext4_get_block(struct inode *inode, sector_t iblock,
2100                                 struct buffer_head *bh_result, int create);
2101 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
2102                            struct buffer_head *bh, int create);
2103 int ext4_walk_page_buffers(handle_t *handle,
2104                            struct buffer_head *head,
2105                            unsigned from,
2106                            unsigned to,
2107                            int *partial,
2108                            int (*fn)(handle_t *handle,
2109                                      struct buffer_head *bh));
2110 int do_journal_get_write_access(handle_t *handle,
2111                                 struct buffer_head *bh);
2112 #define FALL_BACK_TO_NONDELALLOC 1
2113 #define CONVERT_INLINE_DATA      2
2114
2115 extern struct inode *ext4_iget(struct super_block *, unsigned long);
2116 extern struct inode *ext4_iget_normal(struct super_block *, unsigned long);
2117 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
2118 extern int  ext4_setattr(struct dentry *, struct iattr *);
2119 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
2120                                 struct kstat *stat);
2121 extern void ext4_evict_inode(struct inode *);
2122 extern void ext4_clear_inode(struct inode *);
2123 extern int  ext4_sync_inode(handle_t *, struct inode *);
2124 extern void ext4_dirty_inode(struct inode *, int);
2125 extern int ext4_change_inode_journal_flag(struct inode *, int);
2126 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
2127 extern int ext4_inode_attach_jinode(struct inode *inode);
2128 extern int ext4_can_truncate(struct inode *inode);
2129 extern void ext4_truncate(struct inode *);
2130 extern int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length);
2131 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
2132 extern void ext4_set_inode_flags(struct inode *);
2133 extern void ext4_get_inode_flags(struct ext4_inode_info *);
2134 extern int ext4_alloc_da_blocks(struct inode *inode);
2135 extern void ext4_set_aops(struct inode *inode);
2136 extern int ext4_writepage_trans_blocks(struct inode *);
2137 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
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                                 struct iov_iter *iter, loff_t offset);
2150 extern int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock);
2151 extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks);
2152 extern void ext4_ind_truncate(handle_t *, struct inode *inode);
2153 extern int ext4_ind_remove_space(handle_t *handle, struct inode *inode,
2154                                  ext4_lblk_t start, ext4_lblk_t end);
2155
2156 /* ioctl.c */
2157 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
2158 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
2159
2160 /* migrate.c */
2161 extern int ext4_ext_migrate(struct inode *);
2162 extern int ext4_ind_migrate(struct inode *inode);
2163
2164 /* namei.c */
2165 extern int ext4_dirent_csum_verify(struct inode *inode,
2166                                    struct ext4_dir_entry *dirent);
2167 extern int ext4_orphan_add(handle_t *, struct inode *);
2168 extern int ext4_orphan_del(handle_t *, struct inode *);
2169 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
2170                                 __u32 start_minor_hash, __u32 *next_hash);
2171 extern int search_dir(struct buffer_head *bh,
2172                       char *search_buf,
2173                       int buf_size,
2174                       struct inode *dir,
2175                       const struct qstr *d_name,
2176                       unsigned int offset,
2177                       struct ext4_dir_entry_2 **res_dir);
2178 extern int ext4_generic_delete_entry(handle_t *handle,
2179                                      struct inode *dir,
2180                                      struct ext4_dir_entry_2 *de_del,
2181                                      struct buffer_head *bh,
2182                                      void *entry_buf,
2183                                      int buf_size,
2184                                      int csum_size);
2185
2186 /* resize.c */
2187 extern int ext4_group_add(struct super_block *sb,
2188                                 struct ext4_new_group_data *input);
2189 extern int ext4_group_extend(struct super_block *sb,
2190                                 struct ext4_super_block *es,
2191                                 ext4_fsblk_t n_blocks_count);
2192 extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
2193
2194 /* super.c */
2195 extern int ext4_calculate_overhead(struct super_block *sb);
2196 extern void ext4_superblock_csum_set(struct super_block *sb);
2197 extern void *ext4_kvmalloc(size_t size, gfp_t flags);
2198 extern void *ext4_kvzalloc(size_t size, gfp_t flags);
2199 extern void ext4_kvfree(void *ptr);
2200 extern int ext4_alloc_flex_bg_array(struct super_block *sb,
2201                                     ext4_group_t ngroup);
2202 extern const char *ext4_decode_error(struct super_block *sb, int errno,
2203                                      char nbuf[16]);
2204
2205 extern __printf(4, 5)
2206 void __ext4_error(struct super_block *, const char *, unsigned int,
2207                   const char *, ...);
2208 extern __printf(5, 6)
2209 void __ext4_error_inode(struct inode *, const char *, unsigned int, ext4_fsblk_t,
2210                       const char *, ...);
2211 extern __printf(5, 6)
2212 void __ext4_error_file(struct file *, const char *, unsigned int, ext4_fsblk_t,
2213                      const char *, ...);
2214 extern void __ext4_std_error(struct super_block *, const char *,
2215                              unsigned int, int);
2216 extern __printf(4, 5)
2217 void __ext4_abort(struct super_block *, const char *, unsigned int,
2218                   const char *, ...);
2219 extern __printf(4, 5)
2220 void __ext4_warning(struct super_block *, const char *, unsigned int,
2221                     const char *, ...);
2222 extern __printf(3, 4)
2223 void __ext4_msg(struct super_block *, const char *, const char *, ...);
2224 extern void __dump_mmp_msg(struct super_block *, struct mmp_struct *mmp,
2225                            const char *, unsigned int, const char *);
2226 extern __printf(7, 8)
2227 void __ext4_grp_locked_error(const char *, unsigned int,
2228                              struct super_block *, ext4_group_t,
2229                              unsigned long, ext4_fsblk_t,
2230                              const char *, ...);
2231
2232 #ifdef CONFIG_PRINTK
2233
2234 #define ext4_error_inode(inode, func, line, block, fmt, ...)            \
2235         __ext4_error_inode(inode, func, line, block, fmt, ##__VA_ARGS__)
2236 #define ext4_error_file(file, func, line, block, fmt, ...)              \
2237         __ext4_error_file(file, func, line, block, fmt, ##__VA_ARGS__)
2238 #define ext4_error(sb, fmt, ...)                                        \
2239         __ext4_error(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2240 #define ext4_abort(sb, fmt, ...)                                        \
2241         __ext4_abort(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2242 #define ext4_warning(sb, fmt, ...)                                      \
2243         __ext4_warning(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2244 #define ext4_msg(sb, level, fmt, ...)                           \
2245         __ext4_msg(sb, level, fmt, ##__VA_ARGS__)
2246 #define dump_mmp_msg(sb, mmp, msg)                                      \
2247         __dump_mmp_msg(sb, mmp, __func__, __LINE__, msg)
2248 #define ext4_grp_locked_error(sb, grp, ino, block, fmt, ...)            \
2249         __ext4_grp_locked_error(__func__, __LINE__, sb, grp, ino, block, \
2250                                 fmt, ##__VA_ARGS__)
2251
2252 #else
2253
2254 #define ext4_error_inode(inode, func, line, block, fmt, ...)            \
2255 do {                                                                    \
2256         no_printk(fmt, ##__VA_ARGS__);                                  \
2257         __ext4_error_inode(inode, "", 0, block, " ");                   \
2258 } while (0)
2259 #define ext4_error_file(file, func, line, block, fmt, ...)              \
2260 do {                                                                    \
2261         no_printk(fmt, ##__VA_ARGS__);                                  \
2262         __ext4_error_file(file, "", 0, block, " ");                     \
2263 } while (0)
2264 #define ext4_error(sb, fmt, ...)                                        \
2265 do {                                                                    \
2266         no_printk(fmt, ##__VA_ARGS__);                                  \
2267         __ext4_error(sb, "", 0, " ");                                   \
2268 } while (0)
2269 #define ext4_abort(sb, fmt, ...)                                        \
2270 do {                                                                    \
2271         no_printk(fmt, ##__VA_ARGS__);                                  \
2272         __ext4_abort(sb, "", 0, " ");                                   \
2273 } while (0)
2274 #define ext4_warning(sb, fmt, ...)                                      \
2275 do {                                                                    \
2276         no_printk(fmt, ##__VA_ARGS__);                                  \
2277         __ext4_warning(sb, "", 0, " ");                                 \
2278 } while (0)
2279 #define ext4_msg(sb, level, fmt, ...)                                   \
2280 do {                                                                    \
2281         no_printk(fmt, ##__VA_ARGS__);                                  \
2282         __ext4_msg(sb, "", " ");                                        \
2283 } while (0)
2284 #define dump_mmp_msg(sb, mmp, msg)                                      \
2285         __dump_mmp_msg(sb, mmp, "", 0, "")
2286 #define ext4_grp_locked_error(sb, grp, ino, block, fmt, ...)            \
2287 do {                                                                    \
2288         no_printk(fmt, ##__VA_ARGS__);                          \
2289         __ext4_grp_locked_error("", 0, sb, grp, ino, block, " ");       \
2290 } while (0)
2291
2292 #endif
2293
2294 extern void ext4_update_dynamic_rev(struct super_block *sb);
2295 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
2296                                         __u32 compat);
2297 extern int ext4_update_rocompat_feature(handle_t *handle,
2298                                         struct super_block *sb, __u32 rocompat);
2299 extern int ext4_update_incompat_feature(handle_t *handle,
2300                                         struct super_block *sb, __u32 incompat);
2301 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
2302                                       struct ext4_group_desc *bg);
2303 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
2304                                       struct ext4_group_desc *bg);
2305 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
2306                                      struct ext4_group_desc *bg);
2307 extern __u32 ext4_free_group_clusters(struct super_block *sb,
2308                                       struct ext4_group_desc *bg);
2309 extern __u32 ext4_free_inodes_count(struct super_block *sb,
2310                                  struct ext4_group_desc *bg);
2311 extern __u32 ext4_used_dirs_count(struct super_block *sb,
2312                                 struct ext4_group_desc *bg);
2313 extern __u32 ext4_itable_unused_count(struct super_block *sb,
2314                                    struct ext4_group_desc *bg);
2315 extern void ext4_block_bitmap_set(struct super_block *sb,
2316                                   struct ext4_group_desc *bg, ext4_fsblk_t blk);
2317 extern void ext4_inode_bitmap_set(struct super_block *sb,
2318                                   struct ext4_group_desc *bg, ext4_fsblk_t blk);
2319 extern void ext4_inode_table_set(struct super_block *sb,
2320                                  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2321 extern void ext4_free_group_clusters_set(struct super_block *sb,
2322                                          struct ext4_group_desc *bg,
2323                                          __u32 count);
2324 extern void ext4_free_inodes_set(struct super_block *sb,
2325                                 struct ext4_group_desc *bg, __u32 count);
2326 extern void ext4_used_dirs_set(struct super_block *sb,
2327                                 struct ext4_group_desc *bg, __u32 count);
2328 extern void ext4_itable_unused_set(struct super_block *sb,
2329                                    struct ext4_group_desc *bg, __u32 count);
2330 extern int ext4_group_desc_csum_verify(struct super_block *sb, __u32 group,
2331                                        struct ext4_group_desc *gdp);
2332 extern void ext4_group_desc_csum_set(struct super_block *sb, __u32 group,
2333                                      struct ext4_group_desc *gdp);
2334 extern int ext4_register_li_request(struct super_block *sb,
2335                                     ext4_group_t first_not_zeroed);
2336
2337 static inline int ext4_has_group_desc_csum(struct super_block *sb)
2338 {
2339         return EXT4_HAS_RO_COMPAT_FEATURE(sb,
2340                                           EXT4_FEATURE_RO_COMPAT_GDT_CSUM) ||
2341                (EXT4_SB(sb)->s_chksum_driver != NULL);
2342 }
2343
2344 static inline int ext4_has_metadata_csum(struct super_block *sb)
2345 {
2346         WARN_ON_ONCE(EXT4_HAS_RO_COMPAT_FEATURE(sb,
2347                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
2348                      !EXT4_SB(sb)->s_chksum_driver);
2349
2350         return (EXT4_SB(sb)->s_chksum_driver != NULL);
2351 }
2352 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
2353 {
2354         return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
2355                 le32_to_cpu(es->s_blocks_count_lo);
2356 }
2357
2358 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
2359 {
2360         return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
2361                 le32_to_cpu(es->s_r_blocks_count_lo);
2362 }
2363
2364 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
2365 {
2366         return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
2367                 le32_to_cpu(es->s_free_blocks_count_lo);
2368 }
2369
2370 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
2371                                          ext4_fsblk_t blk)
2372 {
2373         es->s_blocks_count_lo = cpu_to_le32((u32)blk);
2374         es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
2375 }
2376
2377 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
2378                                               ext4_fsblk_t blk)
2379 {
2380         es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
2381         es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
2382 }
2383
2384 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
2385                                            ext4_fsblk_t blk)
2386 {
2387         es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
2388         es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
2389 }
2390
2391 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
2392 {
2393         if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
2394                 return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
2395                         le32_to_cpu(raw_inode->i_size_lo);
2396         else
2397                 return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
2398 }
2399
2400 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
2401 {
2402         raw_inode->i_size_lo = cpu_to_le32(i_size);
2403         raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
2404 }
2405
2406 static inline
2407 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
2408                                             ext4_group_t group)
2409 {
2410          struct ext4_group_info ***grp_info;
2411          long indexv, indexh;
2412          BUG_ON(group >= EXT4_SB(sb)->s_groups_count);
2413          grp_info = EXT4_SB(sb)->s_group_info;
2414          indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
2415          indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
2416          return grp_info[indexv][indexh];
2417 }
2418
2419 /*
2420  * Reading s_groups_count requires using smp_rmb() afterwards.  See
2421  * the locking protocol documented in the comments of ext4_group_add()
2422  * in resize.c
2423  */
2424 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
2425 {
2426         ext4_group_t    ngroups = EXT4_SB(sb)->s_groups_count;
2427
2428         smp_rmb();
2429         return ngroups;
2430 }
2431
2432 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
2433                                              ext4_group_t block_group)
2434 {
2435         return block_group >> sbi->s_log_groups_per_flex;
2436 }
2437
2438 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
2439 {
2440         return 1 << sbi->s_log_groups_per_flex;
2441 }
2442
2443 #define ext4_std_error(sb, errno)                               \
2444 do {                                                            \
2445         if ((errno))                                            \
2446                 __ext4_std_error((sb), __func__, __LINE__, (errno));    \
2447 } while (0)
2448
2449 #ifdef CONFIG_SMP
2450 /* Each CPU can accumulate percpu_counter_batch clusters in their local
2451  * counters. So we need to make sure we have free clusters more
2452  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
2453  */
2454 #define EXT4_FREECLUSTERS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
2455 #else
2456 #define EXT4_FREECLUSTERS_WATERMARK 0
2457 #endif
2458
2459 /* Update i_disksize. Requires i_mutex to avoid races with truncate */
2460 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
2461 {
2462         WARN_ON_ONCE(S_ISREG(inode->i_mode) &&
2463                      !mutex_is_locked(&inode->i_mutex));
2464         down_write(&EXT4_I(inode)->i_data_sem);
2465         if (newsize > EXT4_I(inode)->i_disksize)
2466                 EXT4_I(inode)->i_disksize = newsize;
2467         up_write(&EXT4_I(inode)->i_data_sem);
2468 }
2469
2470 /* Update i_size, i_disksize. Requires i_mutex to avoid races with truncate */
2471 static inline int ext4_update_inode_size(struct inode *inode, loff_t newsize)
2472 {
2473         int changed = 0;
2474
2475         if (newsize > inode->i_size) {
2476                 i_size_write(inode, newsize);
2477                 changed = 1;
2478         }
2479         if (newsize > EXT4_I(inode)->i_disksize) {
2480                 ext4_update_i_disksize(inode, newsize);
2481                 changed |= 2;
2482         }
2483         return changed;
2484 }
2485
2486 struct ext4_group_info {
2487         unsigned long   bb_state;
2488         struct rb_root  bb_free_root;
2489         ext4_grpblk_t   bb_first_free;  /* first free block */
2490         ext4_grpblk_t   bb_free;        /* total free blocks */
2491         ext4_grpblk_t   bb_fragments;   /* nr of freespace fragments */
2492         ext4_grpblk_t   bb_largest_free_order;/* order of largest frag in BG */
2493         struct          list_head bb_prealloc_list;
2494 #ifdef DOUBLE_CHECK
2495         void            *bb_bitmap;
2496 #endif
2497         struct rw_semaphore alloc_sem;
2498         ext4_grpblk_t   bb_counters[];  /* Nr of free power-of-two-block
2499                                          * regions, index is order.
2500                                          * bb_counters[3] = 5 means
2501                                          * 5 free 8-block regions. */
2502 };
2503
2504 #define EXT4_GROUP_INFO_NEED_INIT_BIT           0
2505 #define EXT4_GROUP_INFO_WAS_TRIMMED_BIT         1
2506 #define EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT     2
2507 #define EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT     3
2508
2509 #define EXT4_MB_GRP_NEED_INIT(grp)      \
2510         (test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
2511 #define EXT4_MB_GRP_BBITMAP_CORRUPT(grp)        \
2512         (test_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
2513 #define EXT4_MB_GRP_IBITMAP_CORRUPT(grp)        \
2514         (test_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
2515
2516 #define EXT4_MB_GRP_WAS_TRIMMED(grp)    \
2517         (test_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2518 #define EXT4_MB_GRP_SET_TRIMMED(grp)    \
2519         (set_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2520 #define EXT4_MB_GRP_CLEAR_TRIMMED(grp)  \
2521         (clear_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2522
2523 #define EXT4_MAX_CONTENTION             8
2524 #define EXT4_CONTENTION_THRESHOLD       2
2525
2526 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
2527                                               ext4_group_t group)
2528 {
2529         return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
2530 }
2531
2532 /*
2533  * Returns true if the filesystem is busy enough that attempts to
2534  * access the block group locks has run into contention.
2535  */
2536 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
2537 {
2538         return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
2539 }
2540
2541 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
2542 {
2543         spinlock_t *lock = ext4_group_lock_ptr(sb, group);
2544         if (spin_trylock(lock))
2545                 /*
2546                  * We're able to grab the lock right away, so drop the
2547                  * lock contention counter.
2548                  */
2549                 atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
2550         else {
2551                 /*
2552                  * The lock is busy, so bump the contention counter,
2553                  * and then wait on the spin lock.
2554                  */
2555                 atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
2556                                   EXT4_MAX_CONTENTION);
2557                 spin_lock(lock);
2558         }
2559 }
2560
2561 static inline void ext4_unlock_group(struct super_block *sb,
2562                                         ext4_group_t group)
2563 {
2564         spin_unlock(ext4_group_lock_ptr(sb, group));
2565 }
2566
2567 /*
2568  * Block validity checking
2569  */
2570 #define ext4_check_indirect_blockref(inode, bh)                         \
2571         ext4_check_blockref(__func__, __LINE__, inode,                  \
2572                             (__le32 *)(bh)->b_data,                     \
2573                             EXT4_ADDR_PER_BLOCK((inode)->i_sb))
2574
2575 #define ext4_ind_check_inode(inode)                                     \
2576         ext4_check_blockref(__func__, __LINE__, inode,                  \
2577                             EXT4_I(inode)->i_data,                      \
2578                             EXT4_NDIR_BLOCKS)
2579
2580 /*
2581  * Inodes and files operations
2582  */
2583
2584 /* dir.c */
2585 extern const struct file_operations ext4_dir_operations;
2586
2587 /* file.c */
2588 extern const struct inode_operations ext4_file_inode_operations;
2589 extern const struct file_operations ext4_file_operations;
2590 extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
2591
2592 /* inline.c */
2593 extern int ext4_get_max_inline_size(struct inode *inode);
2594 extern int ext4_find_inline_data_nolock(struct inode *inode);
2595 extern int ext4_init_inline_data(handle_t *handle, struct inode *inode,
2596                                  unsigned int len);
2597 extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);
2598
2599 extern int ext4_readpage_inline(struct inode *inode, struct page *page);
2600 extern int ext4_try_to_write_inline_data(struct address_space *mapping,
2601                                          struct inode *inode,
2602                                          loff_t pos, unsigned len,
2603                                          unsigned flags,
2604                                          struct page **pagep);
2605 extern int ext4_write_inline_data_end(struct inode *inode,
2606                                       loff_t pos, unsigned len,
2607                                       unsigned copied,
2608                                       struct page *page);
2609 extern struct buffer_head *
2610 ext4_journalled_write_inline_data(struct inode *inode,
2611                                   unsigned len,
2612                                   struct page *page);
2613 extern int ext4_da_write_inline_data_begin(struct address_space *mapping,
2614                                            struct inode *inode,
2615                                            loff_t pos, unsigned len,
2616                                            unsigned flags,
2617                                            struct page **pagep,
2618                                            void **fsdata);
2619 extern int ext4_da_write_inline_data_end(struct inode *inode, loff_t pos,
2620                                          unsigned len, unsigned copied,
2621                                          struct page *page);
2622 extern int ext4_try_add_inline_entry(handle_t *handle, struct dentry *dentry,
2623                                      struct inode *inode);
2624 extern int ext4_try_create_inline_dir(handle_t *handle,
2625                                       struct inode *parent,
2626                                       struct inode *inode);
2627 extern int ext4_read_inline_dir(struct file *filp,
2628                                 struct dir_context *ctx,
2629                                 int *has_inline_data);
2630 extern int htree_inlinedir_to_tree(struct file *dir_file,
2631                                    struct inode *dir, ext4_lblk_t block,
2632                                    struct dx_hash_info *hinfo,
2633                                    __u32 start_hash, __u32 start_minor_hash,
2634                                    int *has_inline_data);
2635 extern struct buffer_head *ext4_find_inline_entry(struct inode *dir,
2636                                         const struct qstr *d_name,
2637                                         struct ext4_dir_entry_2 **res_dir,
2638                                         int *has_inline_data);
2639 extern int ext4_delete_inline_entry(handle_t *handle,
2640                                     struct inode *dir,
2641                                     struct ext4_dir_entry_2 *de_del,
2642                                     struct buffer_head *bh,
2643                                     int *has_inline_data);
2644 extern int empty_inline_dir(struct inode *dir, int *has_inline_data);
2645 extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
2646                                         struct ext4_dir_entry_2 **parent_de,
2647                                         int *retval);
2648 extern int ext4_inline_data_fiemap(struct inode *inode,
2649                                    struct fiemap_extent_info *fieinfo,
2650                                    int *has_inline);
2651 extern int ext4_try_to_evict_inline_data(handle_t *handle,
2652                                          struct inode *inode,
2653                                          int needed);
2654 extern void ext4_inline_data_truncate(struct inode *inode, int *has_inline);
2655
2656 extern int ext4_convert_inline_data(struct inode *inode);
2657
2658 static inline int ext4_has_inline_data(struct inode *inode)
2659 {
2660         return ext4_test_inode_flag(inode, EXT4_INODE_INLINE_DATA) &&
2661                EXT4_I(inode)->i_inline_off;
2662 }
2663
2664 /* namei.c */
2665 extern const struct inode_operations ext4_dir_inode_operations;
2666 extern const struct inode_operations ext4_special_inode_operations;
2667 extern struct dentry *ext4_get_parent(struct dentry *child);
2668 extern struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2669                                  struct ext4_dir_entry_2 *de,
2670                                  int blocksize, int csum_size,
2671                                  unsigned int parent_ino, int dotdot_real_len);
2672 extern void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
2673                                    unsigned int blocksize);
2674 extern int ext4_handle_dirty_dirent_node(handle_t *handle,
2675                                          struct inode *inode,
2676                                          struct buffer_head *bh);
2677 #define S_SHIFT 12
2678 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
2679         [S_IFREG >> S_SHIFT]    = EXT4_FT_REG_FILE,
2680         [S_IFDIR >> S_SHIFT]    = EXT4_FT_DIR,
2681         [S_IFCHR >> S_SHIFT]    = EXT4_FT_CHRDEV,
2682         [S_IFBLK >> S_SHIFT]    = EXT4_FT_BLKDEV,
2683         [S_IFIFO >> S_SHIFT]    = EXT4_FT_FIFO,
2684         [S_IFSOCK >> S_SHIFT]   = EXT4_FT_SOCK,
2685         [S_IFLNK >> S_SHIFT]    = EXT4_FT_SYMLINK,
2686 };
2687
2688 static inline void ext4_set_de_type(struct super_block *sb,
2689                                 struct ext4_dir_entry_2 *de,
2690                                 umode_t mode) {
2691         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
2692                 de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
2693 }
2694
2695
2696 /* symlink.c */
2697 extern const struct inode_operations ext4_symlink_inode_operations;
2698 extern const struct inode_operations ext4_fast_symlink_inode_operations;
2699
2700 /* block_validity */
2701 extern void ext4_release_system_zone(struct super_block *sb);
2702 extern int ext4_setup_system_zone(struct super_block *sb);
2703 extern int __init ext4_init_system_zone(void);
2704 extern void ext4_exit_system_zone(void);
2705 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
2706                                  ext4_fsblk_t start_blk,
2707                                  unsigned int count);
2708 extern int ext4_check_blockref(const char *, unsigned int,
2709                                struct inode *, __le32 *, unsigned int);
2710
2711 /* extents.c */
2712 struct ext4_ext_path;
2713 struct ext4_extent;
2714
2715 /*
2716  * Maximum number of logical blocks in a file; ext4_extent's ee_block is
2717  * __le32.
2718  */
2719 #define EXT_MAX_BLOCKS  0xffffffff
2720
2721 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
2722 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
2723 extern int ext4_ext_index_trans_blocks(struct inode *inode, int extents);
2724 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
2725                                struct ext4_map_blocks *map, int flags);
2726 extern void ext4_ext_truncate(handle_t *, struct inode *);
2727 extern int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2728                                  ext4_lblk_t end);
2729 extern void ext4_ext_init(struct super_block *);
2730 extern void ext4_ext_release(struct super_block *);
2731 extern long ext4_fallocate(struct file *file, int mode, loff_t offset,
2732                           loff_t len);
2733 extern int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
2734                                           loff_t offset, ssize_t len);
2735 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
2736                            struct ext4_map_blocks *map, int flags);
2737 extern int ext4_ext_calc_metadata_amount(struct inode *inode,
2738                                          ext4_lblk_t lblocks);
2739 extern int ext4_extent_tree_init(handle_t *, struct inode *);
2740 extern int ext4_ext_calc_credits_for_single_extent(struct inode *inode,
2741                                                    int num,
2742                                                    struct ext4_ext_path *path);
2743 extern int ext4_can_extents_be_merged(struct inode *inode,
2744                                       struct ext4_extent *ex1,
2745                                       struct ext4_extent *ex2);
2746 extern int ext4_ext_insert_extent(handle_t *, struct inode *,
2747                                   struct ext4_ext_path **,
2748                                   struct ext4_extent *, int);
2749 extern struct ext4_ext_path *ext4_find_extent(struct inode *, ext4_lblk_t,
2750                                               struct ext4_ext_path **,
2751                                               int flags);
2752 extern void ext4_ext_drop_refs(struct ext4_ext_path *);
2753 extern int ext4_ext_check_inode(struct inode *inode);
2754 extern int ext4_find_delalloc_range(struct inode *inode,
2755                                     ext4_lblk_t lblk_start,
2756                                     ext4_lblk_t lblk_end);
2757 extern int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk);
2758 extern ext4_lblk_t ext4_ext_next_allocated_block(struct ext4_ext_path *path);
2759 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
2760                         __u64 start, __u64 len);
2761 extern int ext4_ext_precache(struct inode *inode);
2762 extern int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len);
2763 extern int ext4_swap_extents(handle_t *handle, struct inode *inode1,
2764                                 struct inode *inode2, ext4_lblk_t lblk1,
2765                              ext4_lblk_t lblk2,  ext4_lblk_t count,
2766                              int mark_unwritten,int *err);
2767
2768 /* move_extent.c */
2769 extern void ext4_double_down_write_data_sem(struct inode *first,
2770                                             struct inode *second);
2771 extern void ext4_double_up_write_data_sem(struct inode *orig_inode,
2772                                           struct inode *donor_inode);
2773 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
2774                              __u64 start_orig, __u64 start_donor,
2775                              __u64 len, __u64 *moved_len);
2776
2777 /* page-io.c */
2778 extern int __init ext4_init_pageio(void);
2779 extern void ext4_exit_pageio(void);
2780 extern ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags);
2781 extern ext4_io_end_t *ext4_get_io_end(ext4_io_end_t *io_end);
2782 extern int ext4_put_io_end(ext4_io_end_t *io_end);
2783 extern void ext4_put_io_end_defer(ext4_io_end_t *io_end);
2784 extern void ext4_io_submit_init(struct ext4_io_submit *io,
2785                                 struct writeback_control *wbc);
2786 extern void ext4_end_io_rsv_work(struct work_struct *work);
2787 extern void ext4_io_submit(struct ext4_io_submit *io);
2788 extern int ext4_bio_write_page(struct ext4_io_submit *io,
2789                                struct page *page,
2790                                int len,
2791                                struct writeback_control *wbc,
2792                                bool keep_towrite);
2793
2794 /* mmp.c */
2795 extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
2796
2797 /*
2798  * Note that these flags will never ever appear in a buffer_head's state flag.
2799  * See EXT4_MAP_... to see where this is used.
2800  */
2801 enum ext4_state_bits {
2802         BH_AllocFromCluster     /* allocated blocks were part of already
2803                                  * allocated cluster. */
2804         = BH_JBDPrivateStart
2805 };
2806
2807 /*
2808  * Add new method to test whether block and inode bitmaps are properly
2809  * initialized. With uninit_bg reading the block from disk is not enough
2810  * to mark the bitmap uptodate. We need to also zero-out the bitmap
2811  */
2812 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
2813
2814 static inline int bitmap_uptodate(struct buffer_head *bh)
2815 {
2816         return (buffer_uptodate(bh) &&
2817                         test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
2818 }
2819 static inline void set_bitmap_uptodate(struct buffer_head *bh)
2820 {
2821         set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
2822 }
2823
2824 /*
2825  * Disable DIO read nolock optimization, so new dioreaders will be forced
2826  * to grab i_mutex
2827  */
2828 static inline void ext4_inode_block_unlocked_dio(struct inode *inode)
2829 {
2830         ext4_set_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
2831         smp_mb();
2832 }
2833 static inline void ext4_inode_resume_unlocked_dio(struct inode *inode)
2834 {
2835         smp_mb();
2836         ext4_clear_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
2837 }
2838
2839 #define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
2840
2841 /* For ioend & aio unwritten conversion wait queues */
2842 #define EXT4_WQ_HASH_SZ         37
2843 #define ext4_ioend_wq(v)   (&ext4__ioend_wq[((unsigned long)(v)) %\
2844                                             EXT4_WQ_HASH_SZ])
2845 #define ext4_aio_mutex(v)  (&ext4__aio_mutex[((unsigned long)(v)) %\
2846                                              EXT4_WQ_HASH_SZ])
2847 extern wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
2848 extern struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
2849
2850 #define EXT4_RESIZING   0
2851 extern int ext4_resize_begin(struct super_block *sb);
2852 extern void ext4_resize_end(struct super_block *sb);
2853
2854 #endif  /* __KERNEL__ */
2855
2856 #endif  /* _EXT4_H */