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
  33 /*
  34  * The fourth extended filesystem constants/structures
  35  */
  36
  37 /*
  38  * Define EXT4FS_DEBUG to produce debug messages
  39  */
  40 #undef EXT4FS_DEBUG
  41
  42 /*
  43  * Debug code
  44  */
  45 #ifdef EXT4FS_DEBUG
  46 #define ext4_debug(f, a...)                                             \
  47         do {                                                            \
  48                 printk(KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:",        \
  49                         __FILE__, __LINE__, __func__);                  \
  50                 printk(KERN_DEBUG f, ## a);                             \
  51         } while (0)
  52 #else
  53 #define ext4_debug(f, a...)     do {} while (0)
  54 #endif
  55
  56 /* data type for block offset of block group */
  57 typedef int ext4_grpblk_t;
  58
  59 /* data type for filesystem-wide blocks number */
  60 typedef unsigned long long ext4_fsblk_t;
  61
  62 /* data type for file logical block number */
  63 typedef __u32 ext4_lblk_t;
  64
  65 /* data type for block group number */
  66 typedef unsigned int ext4_group_t;
  67
  68 /*
  69  * Flags used in mballoc's allocation_context flags field.
  70  *
  71  * Also used to show what's going on for debugging purposes when the
  72  * flag field is exported via the traceport interface
  73  */
  74
  75 /* prefer goal again. length */
  76 #define EXT4_MB_HINT_MERGE              0x0001
  77 /* blocks already reserved */
  78 #define EXT4_MB_HINT_RESERVED           0x0002
  79 /* metadata is being allocated */
  80 #define EXT4_MB_HINT_METADATA           0x0004
  81 /* first blocks in the file */
  82 #define EXT4_MB_HINT_FIRST              0x0008
  83 /* search for the best chunk */
  84 #define EXT4_MB_HINT_BEST               0x0010
  85 /* data is being allocated */
  86 #define EXT4_MB_HINT_DATA               0x0020
  87 /* don't preallocate (for tails) */
  88 #define EXT4_MB_HINT_NOPREALLOC         0x0040
  89 /* allocate for locality group */
  90 #define EXT4_MB_HINT_GROUP_ALLOC        0x0080
  91 /* allocate goal blocks or none */
  92 #define EXT4_MB_HINT_GOAL_ONLY          0x0100
  93 /* goal is meaningful */
  94 #define EXT4_MB_HINT_TRY_GOAL           0x0200
  95 /* blocks already pre-reserved by delayed allocation */
  96 #define EXT4_MB_DELALLOC_RESERVED       0x0400
  97 /* We are doing stream allocation */
  98 #define EXT4_MB_STREAM_ALLOC            0x0800
  99
 100
 101 struct ext4_allocation_request {
 102         /* target inode for block we're allocating */
 103         struct inode *inode;
 104         /* how many blocks we want to allocate */
 105         unsigned int len;
 106         /* logical block in target inode */
 107         ext4_lblk_t logical;
 108         /* the closest logical allocated block to the left */
 109         ext4_lblk_t lleft;
 110         /* the closest logical allocated block to the right */
 111         ext4_lblk_t lright;
 112         /* phys. target (a hint) */
 113         ext4_fsblk_t goal;
 114         /* phys. block for the closest logical allocated block to the left */
 115         ext4_fsblk_t pleft;
 116         /* phys. block for the closest logical allocated block to the right */
 117         ext4_fsblk_t pright;
 118         /* flags. see above EXT4_MB_HINT_* */
 119         unsigned int flags;
 120 };
 121
 122 /*
 123  * For delayed allocation tracking
 124  */
 125 struct mpage_da_data {
 126         struct inode *inode;
 127         sector_t b_blocknr;             /* start block number of extent */
 128         size_t b_size;                  /* size of extent */
 129         unsigned long b_state;          /* state of the extent */
 130         unsigned long first_page, next_page;    /* extent of pages */
 131         struct writeback_control *wbc;
 132         int io_done;
 133         int pages_written;
 134         int retval;
 135 };
 136 #define DIO_AIO_UNWRITTEN       0x1
 137 typedef struct ext4_io_end {
 138         struct list_head        list;           /* per-file finished AIO list */
 139         struct inode            *inode;         /* file being written to */
 140         unsigned int            flag;           /* unwritten or not */
 141         int                     error;          /* I/O error code */
 142         ext4_lblk_t             offset;         /* offset in the file */
 143         size_t                  size;           /* size of the extent */
 144         struct work_struct      work;           /* data work queue */
 145 } ext4_io_end_t;
 146
 147 /*
 148  * Special inodes numbers
 149  */
 150 #define EXT4_BAD_INO             1      /* Bad blocks inode */
 151 #define EXT4_ROOT_INO            2      /* Root inode */
 152 #define EXT4_BOOT_LOADER_INO     5      /* Boot loader inode */
 153 #define EXT4_UNDEL_DIR_INO       6      /* Undelete directory inode */
 154 #define EXT4_RESIZE_INO          7      /* Reserved group descriptors inode */
 155 #define EXT4_JOURNAL_INO         8      /* Journal inode */
 156
 157 /* First non-reserved inode for old ext4 filesystems */
 158 #define EXT4_GOOD_OLD_FIRST_INO 11
 159
 160 /*
 161  * Maximal count of links to a file
 162  */
 163 #define EXT4_LINK_MAX           65000
 164
 165 /*
 166  * Macro-instructions used to manage several block sizes
 167  */
 168 #define EXT4_MIN_BLOCK_SIZE             1024
 169 #define EXT4_MAX_BLOCK_SIZE             65536
 170 #define EXT4_MIN_BLOCK_LOG_SIZE         10
 171 #ifdef __KERNEL__
 172 # define EXT4_BLOCK_SIZE(s)             ((s)->s_blocksize)
 173 #else
 174 # define EXT4_BLOCK_SIZE(s)             (EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
 175 #endif
 176 #define EXT4_ADDR_PER_BLOCK(s)          (EXT4_BLOCK_SIZE(s) / sizeof(__u32))
 177 #ifdef __KERNEL__
 178 # define EXT4_BLOCK_SIZE_BITS(s)        ((s)->s_blocksize_bits)
 179 #else
 180 # define EXT4_BLOCK_SIZE_BITS(s)        ((s)->s_log_block_size + 10)
 181 #endif
 182 #ifdef __KERNEL__
 183 #define EXT4_ADDR_PER_BLOCK_BITS(s)     (EXT4_SB(s)->s_addr_per_block_bits)
 184 #define EXT4_INODE_SIZE(s)              (EXT4_SB(s)->s_inode_size)
 185 #define EXT4_FIRST_INO(s)               (EXT4_SB(s)->s_first_ino)
 186 #else
 187 #define EXT4_INODE_SIZE(s)      (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
 188                                  EXT4_GOOD_OLD_INODE_SIZE : \
 189                                  (s)->s_inode_size)
 190 #define EXT4_FIRST_INO(s)       (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
 191                                  EXT4_GOOD_OLD_FIRST_INO : \
 192                                  (s)->s_first_ino)
 193 #endif
 194 #define EXT4_BLOCK_ALIGN(size, blkbits)         ALIGN((size), (1 << (blkbits)))
 195
 196 /*
 197  * Structure of a blocks group descriptor
 198  */
 199 struct ext4_group_desc
 200 {
 201         __le32  bg_block_bitmap_lo;     /* Blocks bitmap block */
 202         __le32  bg_inode_bitmap_lo;     /* Inodes bitmap block */
 203         __le32  bg_inode_table_lo;      /* Inodes table block */
 204         __le16  bg_free_blocks_count_lo;/* Free blocks count */
 205         __le16  bg_free_inodes_count_lo;/* Free inodes count */
 206         __le16  bg_used_dirs_count_lo;  /* Directories count */
 207         __le16  bg_flags;               /* EXT4_BG_flags (INODE_UNINIT, etc) */
 208         __u32   bg_reserved[2];         /* Likely block/inode bitmap checksum */
 209         __le16  bg_itable_unused_lo;    /* Unused inodes count */
 210         __le16  bg_checksum;            /* crc16(sb_uuid+group+desc) */
 211         __le32  bg_block_bitmap_hi;     /* Blocks bitmap block MSB */
 212         __le32  bg_inode_bitmap_hi;     /* Inodes bitmap block MSB */
 213         __le32  bg_inode_table_hi;      /* Inodes table block MSB */
 214         __le16  bg_free_blocks_count_hi;/* Free blocks count MSB */
 215         __le16  bg_free_inodes_count_hi;/* Free inodes count MSB */
 216         __le16  bg_used_dirs_count_hi;  /* Directories count MSB */
 217         __le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
 218         __u32   bg_reserved2[3];
 219 };
 220
 221 /*
 222  * Structure of a flex block group info
 223  */
 224
 225 struct flex_groups {
 226         atomic_t free_inodes;
 227         atomic_t free_blocks;
 228         atomic_t used_dirs;
 229 };
 230
 231 #define EXT4_BG_INODE_UNINIT    0x0001 /* Inode table/bitmap not in use */
 232 #define EXT4_BG_BLOCK_UNINIT    0x0002 /* Block bitmap not in use */
 233 #define EXT4_BG_INODE_ZEROED    0x0004 /* On-disk itable initialized to zero */
 234
 235 /*
 236  * Macro-instructions used to manage group descriptors
 237  */
 238 #define EXT4_MIN_DESC_SIZE              32
 239 #define EXT4_MIN_DESC_SIZE_64BIT        64
 240 #define EXT4_MAX_DESC_SIZE              EXT4_MIN_BLOCK_SIZE
 241 #define EXT4_DESC_SIZE(s)               (EXT4_SB(s)->s_desc_size)
 242 #ifdef __KERNEL__
 243 # define EXT4_BLOCKS_PER_GROUP(s)       (EXT4_SB(s)->s_blocks_per_group)
 244 # define EXT4_DESC_PER_BLOCK(s)         (EXT4_SB(s)->s_desc_per_block)
 245 # define EXT4_INODES_PER_GROUP(s)       (EXT4_SB(s)->s_inodes_per_group)
 246 # define EXT4_DESC_PER_BLOCK_BITS(s)    (EXT4_SB(s)->s_desc_per_block_bits)
 247 #else
 248 # define EXT4_BLOCKS_PER_GROUP(s)       ((s)->s_blocks_per_group)
 249 # define EXT4_DESC_PER_BLOCK(s)         (EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
 250 # define EXT4_INODES_PER_GROUP(s)       ((s)->s_inodes_per_group)
 251 #endif
 252
 253 /*
 254  * Constants relative to the data blocks
 255  */
 256 #define EXT4_NDIR_BLOCKS                12
 257 #define EXT4_IND_BLOCK                  EXT4_NDIR_BLOCKS
 258 #define EXT4_DIND_BLOCK                 (EXT4_IND_BLOCK + 1)
 259 #define EXT4_TIND_BLOCK                 (EXT4_DIND_BLOCK + 1)
 260 #define EXT4_N_BLOCKS                   (EXT4_TIND_BLOCK + 1)
 261
 262 /*
 263  * Inode flags
 264  */
 265 #define EXT4_SECRM_FL                   0x00000001 /* Secure deletion */
 266 #define EXT4_UNRM_FL                    0x00000002 /* Undelete */
 267 #define EXT4_COMPR_FL                   0x00000004 /* Compress file */
 268 #define EXT4_SYNC_FL                    0x00000008 /* Synchronous updates */
 269 #define EXT4_IMMUTABLE_FL               0x00000010 /* Immutable file */
 270 #define EXT4_APPEND_FL                  0x00000020 /* writes to file may only append */
 271 #define EXT4_NODUMP_FL                  0x00000040 /* do not dump file */
 272 #define EXT4_NOATIME_FL                 0x00000080 /* do not update atime */
 273 /* Reserved for compression usage... */
 274 #define EXT4_DIRTY_FL                   0x00000100
 275 #define EXT4_COMPRBLK_FL                0x00000200 /* One or more compressed clusters */
 276 #define EXT4_NOCOMPR_FL                 0x00000400 /* Don't compress */
 277 #define EXT4_ECOMPR_FL                  0x00000800 /* Compression error */
 278 /* End compression flags --- maybe not all used */
 279 #define EXT4_INDEX_FL                   0x00001000 /* hash-indexed directory */
 280 #define EXT4_IMAGIC_FL                  0x00002000 /* AFS directory */
 281 #define EXT4_JOURNAL_DATA_FL            0x00004000 /* file data should be journaled */
 282 #define EXT4_NOTAIL_FL                  0x00008000 /* file tail should not be merged */
 283 #define EXT4_DIRSYNC_FL                 0x00010000 /* dirsync behaviour (directories only) */
 284 #define EXT4_TOPDIR_FL                  0x00020000 /* Top of directory hierarchies*/
 285 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
 286 #define EXT4_EXTENTS_FL                 0x00080000 /* Inode uses extents */
 287 #define EXT4_RESERVED_FL                0x80000000 /* reserved for ext4 lib */
 288
 289 #define EXT4_FL_USER_VISIBLE            0x000BDFFF /* User visible flags */
 290 #define EXT4_FL_USER_MODIFIABLE         0x000B80FF /* User modifiable flags */
 291
 292 /* Flags that should be inherited by new inodes from their parent. */
 293 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
 294                            EXT4_SYNC_FL | EXT4_IMMUTABLE_FL | EXT4_APPEND_FL |\
 295                            EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
 296                            EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
 297                            EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
 298
 299 /* Flags that are appropriate for regular files (all but dir-specific ones). */
 300 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
 301
 302 /* Flags that are appropriate for non-directories/regular files. */
 303 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
 304
 305 /* Mask out flags that are inappropriate for the given type of inode. */
 306 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
 307 {
 308         if (S_ISDIR(mode))
 309                 return flags;
 310         else if (S_ISREG(mode))
 311                 return flags & EXT4_REG_FLMASK;
 312         else
 313                 return flags & EXT4_OTHER_FLMASK;
 314 }
 315
 316 /*
 317  * Inode dynamic state flags
 318  */
 319 #define EXT4_STATE_JDATA                0x00000001 /* journaled data exists */
 320 #define EXT4_STATE_NEW                  0x00000002 /* inode is newly created */
 321 #define EXT4_STATE_XATTR                0x00000004 /* has in-inode xattrs */
 322 #define EXT4_STATE_NO_EXPAND            0x00000008 /* No space for expansion */
 323 #define EXT4_STATE_DA_ALLOC_CLOSE       0x00000010 /* Alloc DA blks on close */
 324 #define EXT4_STATE_EXT_MIGRATE          0x00000020 /* Inode is migrating */
 325
 326 /* Used to pass group descriptor data when online resize is done */
 327 struct ext4_new_group_input {
 328         __u32 group;            /* Group number for this data */
 329         __u64 block_bitmap;     /* Absolute block number of block bitmap */
 330         __u64 inode_bitmap;     /* Absolute block number of inode bitmap */
 331         __u64 inode_table;      /* Absolute block number of inode table start */
 332         __u32 blocks_count;     /* Total number of blocks in this group */
 333         __u16 reserved_blocks;  /* Number of reserved blocks in this group */
 334         __u16 unused;
 335 };
 336
 337 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
 338 struct ext4_new_group_data {
 339         __u32 group;
 340         __u64 block_bitmap;
 341         __u64 inode_bitmap;
 342         __u64 inode_table;
 343         __u32 blocks_count;
 344         __u16 reserved_blocks;
 345         __u16 unused;
 346         __u32 free_blocks_count;
 347 };
 348
 349 /*
 350  * Flags used by ext4_get_blocks()
 351  */
 352         /* Allocate any needed blocks and/or convert an unitialized
 353            extent to be an initialized ext4 */
 354 #define EXT4_GET_BLOCKS_CREATE                  0x0001
 355         /* Request the creation of an unitialized extent */
 356 #define EXT4_GET_BLOCKS_UNINIT_EXT              0x0002
 357 #define EXT4_GET_BLOCKS_CREATE_UNINIT_EXT       (EXT4_GET_BLOCKS_UNINIT_EXT|\
 358                                                  EXT4_GET_BLOCKS_CREATE)
 359         /* Caller is from the delayed allocation writeout path,
 360            so set the magic i_delalloc_reserve_flag after taking the
 361            inode allocation semaphore for */
 362 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE        0x0004
 363         /* Call ext4_da_update_reserve_space() after successfully
 364            allocating the blocks */
 365 #define EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE    0x0008
 366         /* caller is from the direct IO path, request to creation of an
 367         unitialized extents if not allocated, split the uninitialized
 368         extent if blocks has been preallocated already*/
 369 #define EXT4_GET_BLOCKS_DIO                     0x0010
 370 #define EXT4_GET_BLOCKS_CONVERT                 0x0020
 371 #define EXT4_GET_BLOCKS_DIO_CREATE_EXT          (EXT4_GET_BLOCKS_DIO|\
 372                                          EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
 373         /* Convert extent to initialized after direct IO complete */
 374 #define EXT4_GET_BLOCKS_DIO_CONVERT_EXT         (EXT4_GET_BLOCKS_CONVERT|\
 375                                          EXT4_GET_BLOCKS_DIO_CREATE_EXT)
 376
 377 /*
 378  * ioctl commands
 379  */
 380 #define EXT4_IOC_GETFLAGS               FS_IOC_GETFLAGS
 381 #define EXT4_IOC_SETFLAGS               FS_IOC_SETFLAGS
 382 #define EXT4_IOC_GETVERSION             _IOR('f', 3, long)
 383 #define EXT4_IOC_SETVERSION             _IOW('f', 4, long)
 384 #define EXT4_IOC_GETVERSION_OLD         FS_IOC_GETVERSION
 385 #define EXT4_IOC_SETVERSION_OLD         FS_IOC_SETVERSION
 386 #ifdef CONFIG_JBD2_DEBUG
 387 #define EXT4_IOC_WAIT_FOR_READONLY      _IOR('f', 99, long)
 388 #endif
 389 #define EXT4_IOC_GETRSVSZ               _IOR('f', 5, long)
 390 #define EXT4_IOC_SETRSVSZ               _IOW('f', 6, long)
 391 #define EXT4_IOC_GROUP_EXTEND           _IOW('f', 7, unsigned long)
 392 #define EXT4_IOC_GROUP_ADD              _IOW('f', 8, struct ext4_new_group_input)
 393 #define EXT4_IOC_MIGRATE                _IO('f', 9)
 394  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
 395  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
 396 #define EXT4_IOC_ALLOC_DA_BLKS          _IO('f', 12)
 397 #define EXT4_IOC_MOVE_EXT               _IOWR('f', 15, struct move_extent)
 398
 399 /*
 400  * ioctl commands in 32 bit emulation
 401  */
 402 #define EXT4_IOC32_GETFLAGS             FS_IOC32_GETFLAGS
 403 #define EXT4_IOC32_SETFLAGS             FS_IOC32_SETFLAGS
 404 #define EXT4_IOC32_GETVERSION           _IOR('f', 3, int)
 405 #define EXT4_IOC32_SETVERSION           _IOW('f', 4, int)
 406 #define EXT4_IOC32_GETRSVSZ             _IOR('f', 5, int)
 407 #define EXT4_IOC32_SETRSVSZ             _IOW('f', 6, int)
 408 #define EXT4_IOC32_GROUP_EXTEND         _IOW('f', 7, unsigned int)
 409 #ifdef CONFIG_JBD2_DEBUG
 410 #define EXT4_IOC32_WAIT_FOR_READONLY    _IOR('f', 99, int)
 411 #endif
 412 #define EXT4_IOC32_GETVERSION_OLD       FS_IOC32_GETVERSION
 413 #define EXT4_IOC32_SETVERSION_OLD       FS_IOC32_SETVERSION
 414
 415
 416 /*
 417  *  Mount options
 418  */
 419 struct ext4_mount_options {
 420         unsigned long s_mount_opt;
 421         uid_t s_resuid;
 422         gid_t s_resgid;
 423         unsigned long s_commit_interval;
 424         u32 s_min_batch_time, s_max_batch_time;
 425 #ifdef CONFIG_QUOTA
 426         int s_jquota_fmt;
 427         char *s_qf_names[MAXQUOTAS];
 428 #endif
 429 };
 430
 431 /* Max physical block we can addres w/o extents */
 432 #define EXT4_MAX_BLOCK_FILE_PHYS        0xFFFFFFFF
 433
 434 /*
 435  * Structure of an inode on the disk
 436  */
 437 struct ext4_inode {
 438         __le16  i_mode;         /* File mode */
 439         __le16  i_uid;          /* Low 16 bits of Owner Uid */
 440         __le32  i_size_lo;      /* Size in bytes */
 441         __le32  i_atime;        /* Access time */
 442         __le32  i_ctime;        /* Inode Change time */
 443         __le32  i_mtime;        /* Modification time */
 444         __le32  i_dtime;        /* Deletion Time */
 445         __le16  i_gid;          /* Low 16 bits of Group Id */
 446         __le16  i_links_count;  /* Links count */
 447         __le32  i_blocks_lo;    /* Blocks count */
 448         __le32  i_flags;        /* File flags */
 449         union {
 450                 struct {
 451                         __le32  l_i_version;
 452                 } linux1;
 453                 struct {
 454                         __u32  h_i_translator;
 455                 } hurd1;
 456                 struct {
 457                         __u32  m_i_reserved1;
 458                 } masix1;
 459         } osd1;                         /* OS dependent 1 */
 460         __le32  i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
 461         __le32  i_generation;   /* File version (for NFS) */
 462         __le32  i_file_acl_lo;  /* File ACL */
 463         __le32  i_size_high;
 464         __le32  i_obso_faddr;   /* Obsoleted fragment address */
 465         union {
 466                 struct {
 467                         __le16  l_i_blocks_high; /* were l_i_reserved1 */
 468                         __le16  l_i_file_acl_high;
 469                         __le16  l_i_uid_high;   /* these 2 fields */
 470                         __le16  l_i_gid_high;   /* were reserved2[0] */
 471                         __u32   l_i_reserved2;
 472                 } linux2;
 473                 struct {
 474                         __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
 475                         __u16   h_i_mode_high;
 476                         __u16   h_i_uid_high;
 477                         __u16   h_i_gid_high;
 478                         __u32   h_i_author;
 479                 } hurd2;
 480                 struct {
 481                         __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
 482                         __le16  m_i_file_acl_high;
 483                         __u32   m_i_reserved2[2];
 484                 } masix2;
 485         } osd2;                         /* OS dependent 2 */
 486         __le16  i_extra_isize;
 487         __le16  i_pad1;
 488         __le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
 489         __le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
 490         __le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
 491         __le32  i_crtime;       /* File Creation time */
 492         __le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
 493         __le32  i_version_hi;   /* high 32 bits for 64-bit version */
 494 };
 495
 496 struct move_extent {
 497         __u32 reserved;         /* should be zero */
 498         __u32 donor_fd;         /* donor file descriptor */
 499         __u64 orig_start;       /* logical start offset in block for orig */
 500         __u64 donor_start;      /* logical start offset in block for donor */
 501         __u64 len;              /* block length to be moved */
 502         __u64 moved_len;        /* moved block length */
 503 };
 504
 505 #define EXT4_EPOCH_BITS 2
 506 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
 507 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
 508
 509 /*
 510  * Extended fields will fit into an inode if the filesystem was formatted
 511  * with large inodes (-I 256 or larger) and there are not currently any EAs
 512  * consuming all of the available space. For new inodes we always reserve
 513  * enough space for the kernel's known extended fields, but for inodes
 514  * created with an old kernel this might not have been the case. None of
 515  * the extended inode fields is critical for correct filesystem operation.
 516  * This macro checks if a certain field fits in the inode. Note that
 517  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
 518  */
 519 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)   \
 520         ((offsetof(typeof(*ext4_inode), field) +        \
 521           sizeof((ext4_inode)->field))                  \
 522         <= (EXT4_GOOD_OLD_INODE_SIZE +                  \
 523             (einode)->i_extra_isize))                   \
 524
 525 static inline __le32 ext4_encode_extra_time(struct timespec *time)
 526 {
 527        return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
 528                            (time->tv_sec >> 32) & EXT4_EPOCH_MASK : 0) |
 529                           ((time->tv_nsec << EXT4_EPOCH_BITS) & EXT4_NSEC_MASK));
 530 }
 531
 532 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
 533 {
 534        if (sizeof(time->tv_sec) > 4)
 535                time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
 536                                << 32;
 537        time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
 538 }
 539
 540 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)                          \
 541 do {                                                                           \
 542         (raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);               \
 543         if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
 544                 (raw_inode)->xtime ## _extra =                                 \
 545                                 ext4_encode_extra_time(&(inode)->xtime);       \
 546 } while (0)
 547
 548 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)                        \
 549 do {                                                                           \
 550         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))                      \
 551                 (raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
 552         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))            \
 553                 (raw_inode)->xtime ## _extra =                                 \
 554                                 ext4_encode_extra_time(&(einode)->xtime);      \
 555 } while (0)
 556
 557 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)                          \
 558 do {                                                                           \
 559         (inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
 560         if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
 561                 ext4_decode_extra_time(&(inode)->xtime,                        \
 562                                        raw_inode->xtime ## _extra);            \
 563 } while (0)
 564
 565 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)                        \
 566 do {                                                                           \
 567         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))                      \
 568                 (einode)->xtime.tv_sec =                                       \
 569                         (signed)le32_to_cpu((raw_inode)->xtime);               \
 570         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))            \
 571                 ext4_decode_extra_time(&(einode)->xtime,                       \
 572                                        raw_inode->xtime ## _extra);            \
 573 } while (0)
 574
 575 #define i_disk_version osd1.linux1.l_i_version
 576
 577 #if defined(__KERNEL__) || defined(__linux__)
 578 #define i_reserved1     osd1.linux1.l_i_reserved1
 579 #define i_file_acl_high osd2.linux2.l_i_file_acl_high
 580 #define i_blocks_high   osd2.linux2.l_i_blocks_high
 581 #define i_uid_low       i_uid
 582 #define i_gid_low       i_gid
 583 #define i_uid_high      osd2.linux2.l_i_uid_high
 584 #define i_gid_high      osd2.linux2.l_i_gid_high
 585 #define i_reserved2     osd2.linux2.l_i_reserved2
 586
 587 #elif defined(__GNU__)
 588
 589 #define i_translator    osd1.hurd1.h_i_translator
 590 #define i_uid_high      osd2.hurd2.h_i_uid_high
 591 #define i_gid_high      osd2.hurd2.h_i_gid_high
 592 #define i_author        osd2.hurd2.h_i_author
 593
 594 #elif defined(__masix__)
 595
 596 #define i_reserved1     osd1.masix1.m_i_reserved1
 597 #define i_file_acl_high osd2.masix2.m_i_file_acl_high
 598 #define i_reserved2     osd2.masix2.m_i_reserved2
 599
 600 #endif /* defined(__KERNEL__) || defined(__linux__) */
 601
 602 /*
 603  * storage for cached extent
 604  */
 605 struct ext4_ext_cache {
 606         ext4_fsblk_t    ec_start;
 607         ext4_lblk_t     ec_block;
 608         __u32           ec_len; /* must be 32bit to return holes */
 609         __u32           ec_type;
 610 };
 611
 612 /*
 613  * fourth extended file system inode data in memory
 614  */
 615 struct ext4_inode_info {
 616         __le32  i_data[15];     /* unconverted */
 617         __u32   i_flags;
 618         ext4_fsblk_t    i_file_acl;
 619         __u32   i_dtime;
 620
 621         /*
 622          * i_block_group is the number of the block group which contains
 623          * this file's inode.  Constant across the lifetime of the inode,
 624          * it is ued for making block allocation decisions - we try to
 625          * place a file's data blocks near its inode block, and new inodes
 626          * near to their parent directory's inode.
 627          */
 628         ext4_group_t    i_block_group;
 629         __u32   i_state;                /* Dynamic state flags for ext4 */
 630
 631         ext4_lblk_t             i_dir_start_lookup;
 632 #ifdef CONFIG_EXT4_FS_XATTR
 633         /*
 634          * Extended attributes can be read independently of the main file
 635          * data. Taking i_mutex even when reading would cause contention
 636          * between readers of EAs and writers of regular file data, so
 637          * instead we synchronize on xattr_sem when reading or changing
 638          * EAs.
 639          */
 640         struct rw_semaphore xattr_sem;
 641 #endif
 642
 643         struct list_head i_orphan;      /* unlinked but open inodes */
 644
 645         /*
 646          * i_disksize keeps track of what the inode size is ON DISK, not
 647          * in memory.  During truncate, i_size is set to the new size by
 648          * the VFS prior to calling ext4_truncate(), but the filesystem won't
 649          * set i_disksize to 0 until the truncate is actually under way.
 650          *
 651          * The intent is that i_disksize always represents the blocks which
 652          * are used by this file.  This allows recovery to restart truncate
 653          * on orphans if we crash during truncate.  We actually write i_disksize
 654          * into the on-disk inode when writing inodes out, instead of i_size.
 655          *
 656          * The only time when i_disksize and i_size may be different is when
 657          * a truncate is in progress.  The only things which change i_disksize
 658          * are ext4_get_block (growth) and ext4_truncate (shrinkth).
 659          */
 660         loff_t  i_disksize;
 661
 662         /*
 663          * i_data_sem is for serialising ext4_truncate() against
 664          * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
 665          * data tree are chopped off during truncate. We can't do that in
 666          * ext4 because whenever we perform intermediate commits during
 667          * truncate, the inode and all the metadata blocks *must* be in a
 668          * consistent state which allows truncation of the orphans to restart
 669          * during recovery.  Hence we must fix the get_block-vs-truncate race
 670          * by other means, so we have i_data_sem.
 671          */
 672         struct rw_semaphore i_data_sem;
 673         struct inode vfs_inode;
 674         struct jbd2_inode jinode;
 675
 676         struct ext4_ext_cache i_cached_extent;
 677         /*
 678          * File creation time. Its function is same as that of
 679          * struct timespec i_{a,c,m}time in the generic inode.
 680          */
 681         struct timespec i_crtime;
 682
 683         /* mballoc */
 684         struct list_head i_prealloc_list;
 685         spinlock_t i_prealloc_lock;
 686
 687         /* ialloc */
 688         ext4_group_t    i_last_alloc_group;
 689
 690         /* allocation reservation info for delalloc */
 691         unsigned int i_reserved_data_blocks;
 692         unsigned int i_reserved_meta_blocks;
 693         unsigned int i_allocated_meta_blocks;
 694         unsigned short i_delalloc_reserved_flag;
 695
 696         /* on-disk additional length */
 697         __u16 i_extra_isize;
 698
 699         spinlock_t i_block_reservation_lock;
 700
 701         /* completed async DIOs that might need unwritten extents handling */
 702         struct list_head i_aio_dio_complete_list;
 703         /* current io_end structure for async DIO write*/
 704         ext4_io_end_t *cur_aio_dio;
 705 };
 706
 707 /*
 708  * File system states
 709  */
 710 #define EXT4_VALID_FS                   0x0001  /* Unmounted cleanly */
 711 #define EXT4_ERROR_FS                   0x0002  /* Errors detected */
 712 #define EXT4_ORPHAN_FS                  0x0004  /* Orphans being recovered */
 713
 714 /*
 715  * Misc. filesystem flags
 716  */
 717 #define EXT2_FLAGS_SIGNED_HASH          0x0001  /* Signed dirhash in use */
 718 #define EXT2_FLAGS_UNSIGNED_HASH        0x0002  /* Unsigned dirhash in use */
 719 #define EXT2_FLAGS_TEST_FILESYS         0x0004  /* to test development code */
 720
 721 /*
 722  * Mount flags
 723  */
 724 #define EXT4_MOUNT_OLDALLOC             0x00002  /* Don't use the new Orlov allocator */
 725 #define EXT4_MOUNT_GRPID                0x00004 /* Create files with directory's group */
 726 #define EXT4_MOUNT_DEBUG                0x00008 /* Some debugging messages */
 727 #define EXT4_MOUNT_ERRORS_CONT          0x00010 /* Continue on errors */
 728 #define EXT4_MOUNT_ERRORS_RO            0x00020 /* Remount fs ro on errors */
 729 #define EXT4_MOUNT_ERRORS_PANIC         0x00040 /* Panic on errors */
 730 #define EXT4_MOUNT_MINIX_DF             0x00080 /* Mimics the Minix statfs */
 731 #define EXT4_MOUNT_NOLOAD               0x00100 /* Don't use existing journal*/
 732 #define EXT4_MOUNT_DATA_FLAGS           0x00C00 /* Mode for data writes: */
 733 #define EXT4_MOUNT_JOURNAL_DATA         0x00400 /* Write data to journal */
 734 #define EXT4_MOUNT_ORDERED_DATA         0x00800 /* Flush data before commit */
 735 #define EXT4_MOUNT_WRITEBACK_DATA       0x00C00 /* No data ordering */
 736 #define EXT4_MOUNT_UPDATE_JOURNAL       0x01000 /* Update the journal format */
 737 #define EXT4_MOUNT_NO_UID32             0x02000  /* Disable 32-bit UIDs */
 738 #define EXT4_MOUNT_XATTR_USER           0x04000 /* Extended user attributes */
 739 #define EXT4_MOUNT_POSIX_ACL            0x08000 /* POSIX Access Control Lists */
 740 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC     0x10000 /* No auto delalloc mapping */
 741 #define EXT4_MOUNT_BARRIER              0x20000 /* Use block barriers */
 742 #define EXT4_MOUNT_NOBH                 0x40000 /* No bufferheads */
 743 #define EXT4_MOUNT_QUOTA                0x80000 /* Some quota option set */
 744 #define EXT4_MOUNT_USRQUOTA             0x100000 /* "old" user quota */
 745 #define EXT4_MOUNT_GRPQUOTA             0x200000 /* "old" group quota */
 746 #define EXT4_MOUNT_JOURNAL_CHECKSUM     0x800000 /* Journal checksums */
 747 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT 0x1000000 /* Journal Async Commit */
 748 #define EXT4_MOUNT_I_VERSION            0x2000000 /* i_version support */
 749 #define EXT4_MOUNT_DELALLOC             0x8000000 /* Delalloc support */
 750 #define EXT4_MOUNT_DATA_ERR_ABORT       0x10000000 /* Abort on file data write */
 751 #define EXT4_MOUNT_BLOCK_VALIDITY       0x20000000 /* Block validity checking */
 752
 753 #define clear_opt(o, opt)               o &= ~EXT4_MOUNT_##opt
 754 #define set_opt(o, opt)                 o |= EXT4_MOUNT_##opt
 755 #define test_opt(sb, opt)               (EXT4_SB(sb)->s_mount_opt & \
 756                                          EXT4_MOUNT_##opt)
 757
 758 #define ext4_set_bit                    ext2_set_bit
 759 #define ext4_set_bit_atomic             ext2_set_bit_atomic
 760 #define ext4_clear_bit                  ext2_clear_bit
 761 #define ext4_clear_bit_atomic           ext2_clear_bit_atomic
 762 #define ext4_test_bit                   ext2_test_bit
 763 #define ext4_find_first_zero_bit        ext2_find_first_zero_bit
 764 #define ext4_find_next_zero_bit         ext2_find_next_zero_bit
 765 #define ext4_find_next_bit              ext2_find_next_bit
 766
 767 /*
 768  * Maximal mount counts between two filesystem checks
 769  */
 770 #define EXT4_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
 771 #define EXT4_DFL_CHECKINTERVAL          0       /* Don't use interval check */
 772
 773 /*
 774  * Behaviour when detecting errors
 775  */
 776 #define EXT4_ERRORS_CONTINUE            1       /* Continue execution */
 777 #define EXT4_ERRORS_RO                  2       /* Remount fs read-only */
 778 #define EXT4_ERRORS_PANIC               3       /* Panic */
 779 #define EXT4_ERRORS_DEFAULT             EXT4_ERRORS_CONTINUE
 780
 781 /*
 782  * Structure of the super block
 783  */
 784 struct ext4_super_block {
 785 /*00*/  __le32  s_inodes_count;         /* Inodes count */
 786         __le32  s_blocks_count_lo;      /* Blocks count */
 787         __le32  s_r_blocks_count_lo;    /* Reserved blocks count */
 788         __le32  s_free_blocks_count_lo; /* Free blocks count */
 789 /*10*/  __le32  s_free_inodes_count;    /* Free inodes count */
 790         __le32  s_first_data_block;     /* First Data Block */
 791         __le32  s_log_block_size;       /* Block size */
 792         __le32  s_obso_log_frag_size;   /* Obsoleted fragment size */
 793 /*20*/  __le32  s_blocks_per_group;     /* # Blocks per group */
 794         __le32  s_obso_frags_per_group; /* Obsoleted fragments per group */
 795         __le32  s_inodes_per_group;     /* # Inodes per group */
 796         __le32  s_mtime;                /* Mount time */
 797 /*30*/  __le32  s_wtime;                /* Write time */
 798         __le16  s_mnt_count;            /* Mount count */
 799         __le16  s_max_mnt_count;        /* Maximal mount count */
 800         __le16  s_magic;                /* Magic signature */
 801         __le16  s_state;                /* File system state */
 802         __le16  s_errors;               /* Behaviour when detecting errors */
 803         __le16  s_minor_rev_level;      /* minor revision level */
 804 /*40*/  __le32  s_lastcheck;            /* time of last check */
 805         __le32  s_checkinterval;        /* max. time between checks */
 806         __le32  s_creator_os;           /* OS */
 807         __le32  s_rev_level;            /* Revision level */
 808 /*50*/  __le16  s_def_resuid;           /* Default uid for reserved blocks */
 809         __le16  s_def_resgid;           /* Default gid for reserved blocks */
 810         /*
 811          * These fields are for EXT4_DYNAMIC_REV superblocks only.
 812          *
 813          * Note: the difference between the compatible feature set and
 814          * the incompatible feature set is that if there is a bit set
 815          * in the incompatible feature set that the kernel doesn't
 816          * know about, it should refuse to mount the filesystem.
 817          *
 818          * e2fsck's requirements are more strict; if it doesn't know
 819          * about a feature in either the compatible or incompatible
 820          * feature set, it must abort and not try to meddle with
 821          * things it doesn't understand...
 822          */
 823         __le32  s_first_ino;            /* First non-reserved inode */
 824         __le16  s_inode_size;           /* size of inode structure */
 825         __le16  s_block_group_nr;       /* block group # of this superblock */
 826         __le32  s_feature_compat;       /* compatible feature set */
 827 /*60*/  __le32  s_feature_incompat;     /* incompatible feature set */
 828         __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
 829 /*68*/  __u8    s_uuid[16];             /* 128-bit uuid for volume */
 830 /*78*/  char    s_volume_name[16];      /* volume name */
 831 /*88*/  char    s_last_mounted[64];     /* directory where last mounted */
 832 /*C8*/  __le32  s_algorithm_usage_bitmap; /* For compression */
 833         /*
 834          * Performance hints.  Directory preallocation should only
 835          * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
 836          */
 837         __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
 838         __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
 839         __le16  s_reserved_gdt_blocks;  /* Per group desc for online growth */
 840         /*
 841          * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
 842          */
 843 /*D0*/  __u8    s_journal_uuid[16];     /* uuid of journal superblock */
 844 /*E0*/  __le32  s_journal_inum;         /* inode number of journal file */
 845         __le32  s_journal_dev;          /* device number of journal file */
 846         __le32  s_last_orphan;          /* start of list of inodes to delete */
 847         __le32  s_hash_seed[4];         /* HTREE hash seed */
 848         __u8    s_def_hash_version;     /* Default hash version to use */
 849         __u8    s_reserved_char_pad;
 850         __le16  s_desc_size;            /* size of group descriptor */
 851 /*100*/ __le32  s_default_mount_opts;
 852         __le32  s_first_meta_bg;        /* First metablock block group */
 853         __le32  s_mkfs_time;            /* When the filesystem was created */
 854         __le32  s_jnl_blocks[17];       /* Backup of the journal inode */
 855         /* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
 856 /*150*/ __le32  s_blocks_count_hi;      /* Blocks count */
 857         __le32  s_r_blocks_count_hi;    /* Reserved blocks count */
 858         __le32  s_free_blocks_count_hi; /* Free blocks count */
 859         __le16  s_min_extra_isize;      /* All inodes have at least # bytes */
 860         __le16  s_want_extra_isize;     /* New inodes should reserve # bytes */
 861         __le32  s_flags;                /* Miscellaneous flags */
 862         __le16  s_raid_stride;          /* RAID stride */
 863         __le16  s_mmp_interval;         /* # seconds to wait in MMP checking */
 864         __le64  s_mmp_block;            /* Block for multi-mount protection */
 865         __le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
 866         __u8    s_log_groups_per_flex;  /* FLEX_BG group size */
 867         __u8    s_reserved_char_pad2;
 868         __le16  s_reserved_pad;
 869         __le64  s_kbytes_written;       /* nr of lifetime kilobytes written */
 870         __u32   s_reserved[160];        /* Padding to the end of the block */
 871 };
 872
 873 #ifdef __KERNEL__
 874
 875 /*
 876  * run-time mount flags
 877  */
 878 #define EXT4_MF_MNTDIR_SAMPLED  0x0001
 879 #define EXT4_MF_FS_ABORTED      0x0002  /* Fatal error detected */
 880
 881 /*
 882  * fourth extended-fs super-block data in memory
 883  */
 884 struct ext4_sb_info {
 885         unsigned long s_desc_size;      /* Size of a group descriptor in bytes */
 886         unsigned long s_inodes_per_block;/* Number of inodes per block */
 887         unsigned long s_blocks_per_group;/* Number of blocks in a group */
 888         unsigned long s_inodes_per_group;/* Number of inodes in a group */
 889         unsigned long s_itb_per_group;  /* Number of inode table blocks per group */
 890         unsigned long s_gdb_count;      /* Number of group descriptor blocks */
 891         unsigned long s_desc_per_block; /* Number of group descriptors per block */
 892         ext4_group_t s_groups_count;    /* Number of groups in the fs */
 893         ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
 894         unsigned long s_overhead_last;  /* Last calculated overhead */
 895         unsigned long s_blocks_last;    /* Last seen block count */
 896         loff_t s_bitmap_maxbytes;       /* max bytes for bitmap files */
 897         struct buffer_head * s_sbh;     /* Buffer containing the super block */
 898         struct ext4_super_block *s_es;  /* Pointer to the super block in the buffer */
 899         struct buffer_head **s_group_desc;
 900         unsigned int s_mount_opt;
 901         unsigned int s_mount_flags;
 902         ext4_fsblk_t s_sb_block;
 903         uid_t s_resuid;
 904         gid_t s_resgid;
 905         unsigned short s_mount_state;
 906         unsigned short s_pad;
 907         int s_addr_per_block_bits;
 908         int s_desc_per_block_bits;
 909         int s_inode_size;
 910         int s_first_ino;
 911         unsigned int s_inode_readahead_blks;
 912         unsigned int s_inode_goal;
 913         spinlock_t s_next_gen_lock;
 914         u32 s_next_generation;
 915         u32 s_hash_seed[4];
 916         int s_def_hash_version;
 917         int s_hash_unsigned;    /* 3 if hash should be signed, 0 if not */
 918         struct percpu_counter s_freeblocks_counter;
 919         struct percpu_counter s_freeinodes_counter;
 920         struct percpu_counter s_dirs_counter;
 921         struct percpu_counter s_dirtyblocks_counter;
 922         struct blockgroup_lock *s_blockgroup_lock;
 923         struct proc_dir_entry *s_proc;
 924         struct kobject s_kobj;
 925         struct completion s_kobj_unregister;
 926
 927         /* Journaling */
 928         struct inode *s_journal_inode;
 929         struct journal_s *s_journal;
 930         struct list_head s_orphan;
 931         struct mutex s_orphan_lock;
 932         struct mutex s_resize_lock;
 933         unsigned long s_commit_interval;
 934         u32 s_max_batch_time;
 935         u32 s_min_batch_time;
 936         struct block_device *journal_bdev;
 937 #ifdef CONFIG_JBD2_DEBUG
 938         struct timer_list turn_ro_timer;        /* For turning read-only (crash simulation) */
 939         wait_queue_head_t ro_wait_queue;        /* For people waiting for the fs to go read-only */
 940 #endif
 941 #ifdef CONFIG_QUOTA
 942         char *s_qf_names[MAXQUOTAS];            /* Names of quota files with journalled quota */
 943         int s_jquota_fmt;                       /* Format of quota to use */
 944 #endif
 945         unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
 946         struct rb_root system_blks;
 947
 948 #ifdef EXTENTS_STATS
 949         /* ext4 extents stats */
 950         unsigned long s_ext_min;
 951         unsigned long s_ext_max;
 952         unsigned long s_depth_max;
 953         spinlock_t s_ext_stats_lock;
 954         unsigned long s_ext_blocks;
 955         unsigned long s_ext_extents;
 956 #endif
 957
 958         /* for buddy allocator */
 959         struct ext4_group_info ***s_group_info;
 960         struct inode *s_buddy_cache;
 961         long s_blocks_reserved;
 962         spinlock_t s_reserve_lock;
 963         spinlock_t s_md_lock;
 964         tid_t s_last_transaction;
 965         unsigned short *s_mb_offsets;
 966         unsigned int *s_mb_maxs;
 967
 968         /* tunables */
 969         unsigned long s_stripe;
 970         unsigned int s_mb_stream_request;
 971         unsigned int s_mb_max_to_scan;
 972         unsigned int s_mb_min_to_scan;
 973         unsigned int s_mb_stats;
 974         unsigned int s_mb_order2_reqs;
 975         unsigned int s_mb_group_prealloc;
 976         unsigned int s_max_writeback_mb_bump;
 977         /* where last allocation was done - for stream allocation */
 978         unsigned long s_mb_last_group;
 979         unsigned long s_mb_last_start;
 980
 981         /* stats for buddy allocator */
 982         spinlock_t s_mb_pa_lock;
 983         atomic_t s_bal_reqs;    /* number of reqs with len > 1 */
 984         atomic_t s_bal_success; /* we found long enough chunks */
 985         atomic_t s_bal_allocated;       /* in blocks */
 986         atomic_t s_bal_ex_scanned;      /* total extents scanned */
 987         atomic_t s_bal_goals;   /* goal hits */
 988         atomic_t s_bal_breaks;  /* too long searches */
 989         atomic_t s_bal_2orders; /* 2^order hits */
 990         spinlock_t s_bal_lock;
 991         unsigned long s_mb_buddies_generated;
 992         unsigned long long s_mb_generation_time;
 993         atomic_t s_mb_lost_chunks;
 994         atomic_t s_mb_preallocated;
 995         atomic_t s_mb_discarded;
 996         atomic_t s_lock_busy;
 997
 998         /* locality groups */
 999         struct ext4_locality_group *s_locality_groups;
1000
1001         /* for write statistics */
1002         unsigned long s_sectors_written_start;
1003         u64 s_kbytes_written;
1004
1005         unsigned int s_log_groups_per_flex;
1006         struct flex_groups *s_flex_groups;
1007
1008         /* workqueue for dio unwritten */
1009         struct workqueue_struct *dio_unwritten_wq;
1010 };
1011
1012 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1013 {
1014         return sb->s_fs_info;
1015 }
1016 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1017 {
1018         return container_of(inode, struct ext4_inode_info, vfs_inode);
1019 }
1020
1021 static inline struct timespec ext4_current_time(struct inode *inode)
1022 {
1023         return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1024                 current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1025 }
1026
1027 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1028 {
1029         return ino == EXT4_ROOT_INO ||
1030                 ino == EXT4_JOURNAL_INO ||
1031                 ino == EXT4_RESIZE_INO ||
1032                 (ino >= EXT4_FIRST_INO(sb) &&
1033                  ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1034 }
1035 #else
1036 /* Assume that user mode programs are passing in an ext4fs superblock, not
1037  * a kernel struct super_block.  This will allow us to call the feature-test
1038  * macros from user land. */
1039 #define EXT4_SB(sb)     (sb)
1040 #endif
1041
1042 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1043
1044 /*
1045  * Codes for operating systems
1046  */
1047 #define EXT4_OS_LINUX           0
1048 #define EXT4_OS_HURD            1
1049 #define EXT4_OS_MASIX           2
1050 #define EXT4_OS_FREEBSD         3
1051 #define EXT4_OS_LITES           4
1052
1053 /*
1054  * Revision levels
1055  */
1056 #define EXT4_GOOD_OLD_REV       0       /* The good old (original) format */
1057 #define EXT4_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
1058
1059 #define EXT4_CURRENT_REV        EXT4_GOOD_OLD_REV
1060 #define EXT4_MAX_SUPP_REV       EXT4_DYNAMIC_REV
1061
1062 #define EXT4_GOOD_OLD_INODE_SIZE 128
1063
1064 /*
1065  * Feature set definitions
1066  */
1067
1068 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)                        \
1069         ((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1070 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
1071         ((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1072 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)                      \
1073         ((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1074 #define EXT4_SET_COMPAT_FEATURE(sb,mask)                        \
1075         EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1076 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)                     \
1077         EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1078 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)                      \
1079         EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1080 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)                      \
1081         EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1082 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
1083         EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1084 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
1085         EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1086
1087 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC        0x0001
1088 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES       0x0002
1089 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL         0x0004
1090 #define EXT4_FEATURE_COMPAT_EXT_ATTR            0x0008
1091 #define EXT4_FEATURE_COMPAT_RESIZE_INODE        0x0010
1092 #define EXT4_FEATURE_COMPAT_DIR_INDEX           0x0020
1093
1094 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
1095 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
1096 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
1097 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1098 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM         0x0010
1099 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK        0x0020
1100 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE      0x0040
1101
1102 #define EXT4_FEATURE_INCOMPAT_COMPRESSION       0x0001
1103 #define EXT4_FEATURE_INCOMPAT_FILETYPE          0x0002
1104 #define EXT4_FEATURE_INCOMPAT_RECOVER           0x0004 /* Needs recovery */
1105 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008 /* Journal device */
1106 #define EXT4_FEATURE_INCOMPAT_META_BG           0x0010
1107 #define EXT4_FEATURE_INCOMPAT_EXTENTS           0x0040 /* extents support */
1108 #define EXT4_FEATURE_INCOMPAT_64BIT             0x0080
1109 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1110 #define EXT4_FEATURE_INCOMPAT_FLEX_BG           0x0200
1111
1112 #define EXT4_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
1113 #define EXT4_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1114                                          EXT4_FEATURE_INCOMPAT_RECOVER| \
1115                                          EXT4_FEATURE_INCOMPAT_META_BG| \
1116                                          EXT4_FEATURE_INCOMPAT_EXTENTS| \
1117                                          EXT4_FEATURE_INCOMPAT_64BIT| \
1118                                          EXT4_FEATURE_INCOMPAT_FLEX_BG)
1119 #define EXT4_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1120                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1121                                          EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1122                                          EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1123                                          EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1124                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1125                                          EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
1126
1127 /*
1128  * Default values for user and/or group using reserved blocks
1129  */
1130 #define EXT4_DEF_RESUID         0
1131 #define EXT4_DEF_RESGID         0
1132
1133 #define EXT4_DEF_INODE_READAHEAD_BLKS   32
1134
1135 /*
1136  * Default mount options
1137  */
1138 #define EXT4_DEFM_DEBUG         0x0001
1139 #define EXT4_DEFM_BSDGROUPS     0x0002
1140 #define EXT4_DEFM_XATTR_USER    0x0004
1141 #define EXT4_DEFM_ACL           0x0008
1142 #define EXT4_DEFM_UID16         0x0010
1143 #define EXT4_DEFM_JMODE         0x0060
1144 #define EXT4_DEFM_JMODE_DATA    0x0020
1145 #define EXT4_DEFM_JMODE_ORDERED 0x0040
1146 #define EXT4_DEFM_JMODE_WBACK   0x0060
1147
1148 /*
1149  * Default journal batch times
1150  */
1151 #define EXT4_DEF_MIN_BATCH_TIME 0
1152 #define EXT4_DEF_MAX_BATCH_TIME 15000 /* 15ms */
1153
1154 /*
1155  * Minimum number of groups in a flexgroup before we separate out
1156  * directories into the first block group of a flexgroup
1157  */
1158 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME 4
1159
1160 /*
1161  * Structure of a directory entry
1162  */
1163 #define EXT4_NAME_LEN 255
1164
1165 struct ext4_dir_entry {
1166         __le32  inode;                  /* Inode number */
1167         __le16  rec_len;                /* Directory entry length */
1168         __le16  name_len;               /* Name length */
1169         char    name[EXT4_NAME_LEN];    /* File name */
1170 };
1171
1172 /*
1173  * The new version of the directory entry.  Since EXT4 structures are
1174  * stored in intel byte order, and the name_len field could never be
1175  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1176  * file_type field.
1177  */
1178 struct ext4_dir_entry_2 {
1179         __le32  inode;                  /* Inode number */
1180         __le16  rec_len;                /* Directory entry length */
1181         __u8    name_len;               /* Name length */
1182         __u8    file_type;
1183         char    name[EXT4_NAME_LEN];    /* File name */
1184 };
1185
1186 /*
1187  * Ext4 directory file types.  Only the low 3 bits are used.  The
1188  * other bits are reserved for now.
1189  */
1190 #define EXT4_FT_UNKNOWN         0
1191 #define EXT4_FT_REG_FILE        1
1192 #define EXT4_FT_DIR             2
1193 #define EXT4_FT_CHRDEV          3
1194 #define EXT4_FT_BLKDEV          4
1195 #define EXT4_FT_FIFO            5
1196 #define EXT4_FT_SOCK            6
1197 #define EXT4_FT_SYMLINK         7
1198
1199 #define EXT4_FT_MAX             8
1200
1201 /*
1202  * EXT4_DIR_PAD defines the directory entries boundaries
1203  *
1204  * NOTE: It must be a multiple of 4
1205  */
1206 #define EXT4_DIR_PAD                    4
1207 #define EXT4_DIR_ROUND                  (EXT4_DIR_PAD - 1)
1208 #define EXT4_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT4_DIR_ROUND) & \
1209                                          ~EXT4_DIR_ROUND)
1210 #define EXT4_MAX_REC_LEN                ((1<<16)-1)
1211
1212 /*
1213  * Hash Tree Directory indexing
1214  * (c) Daniel Phillips, 2001
1215  */
1216
1217 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1218                                       EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1219                       (EXT4_I(dir)->i_flags & EXT4_INDEX_FL))
1220 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1221 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1222
1223 /* Legal values for the dx_root hash_version field: */
1224
1225 #define DX_HASH_LEGACY          0
1226 #define DX_HASH_HALF_MD4        1
1227 #define DX_HASH_TEA             2
1228 #define DX_HASH_LEGACY_UNSIGNED 3
1229 #define DX_HASH_HALF_MD4_UNSIGNED       4
1230 #define DX_HASH_TEA_UNSIGNED            5
1231
1232 #ifdef __KERNEL__
1233
1234 /* hash info structure used by the directory hash */
1235 struct dx_hash_info
1236 {
1237         u32             hash;
1238         u32             minor_hash;
1239         int             hash_version;
1240         u32             *seed;
1241 };
1242
1243 #define EXT4_HTREE_EOF  0x7fffffff
1244
1245 /*
1246  * Control parameters used by ext4_htree_next_block
1247  */
1248 #define HASH_NB_ALWAYS          1
1249
1250
1251 /*
1252  * Describe an inode's exact location on disk and in memory
1253  */
1254 struct ext4_iloc
1255 {
1256         struct buffer_head *bh;
1257         unsigned long offset;
1258         ext4_group_t block_group;
1259 };
1260
1261 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1262 {
1263         return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1264 }
1265
1266 /*
1267  * This structure is stuffed into the struct file's private_data field
1268  * for directories.  It is where we put information so that we can do
1269  * readdir operations in hash tree order.
1270  */
1271 struct dir_private_info {
1272         struct rb_root  root;
1273         struct rb_node  *curr_node;
1274         struct fname    *extra_fname;
1275         loff_t          last_pos;
1276         __u32           curr_hash;
1277         __u32           curr_minor_hash;
1278         __u32           next_hash;
1279 };
1280
1281 /* calculate the first block number of the group */
1282 static inline ext4_fsblk_t
1283 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1284 {
1285         return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1286                 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1287 }
1288
1289 /*
1290  * Special error return code only used by dx_probe() and its callers.
1291  */
1292 #define ERR_BAD_DX_DIR  -75000
1293
1294 void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
1295                         ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp);
1296
1297 extern struct proc_dir_entry *ext4_proc_root;
1298
1299 /*
1300  * Function prototypes
1301  */
1302
1303 /*
1304  * Ok, these declarations are also in <linux/kernel.h> but none of the
1305  * ext4 source programs needs to include it so they are duplicated here.
1306  */
1307 # define NORET_TYPE     /**/
1308 # define ATTRIB_NORET   __attribute__((noreturn))
1309 # define NORET_AND      noreturn,
1310
1311 /* bitmap.c */
1312 extern unsigned int ext4_count_free(struct buffer_head *, unsigned);
1313
1314 /* balloc.c */
1315 extern unsigned int ext4_block_group(struct super_block *sb,
1316                         ext4_fsblk_t blocknr);
1317 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1318                         ext4_fsblk_t blocknr);
1319 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1320 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1321                         ext4_group_t group);
1322 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1323                         ext4_fsblk_t goal, unsigned long *count, int *errp);
1324 extern int ext4_claim_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
1325 extern int ext4_has_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
1326 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
1327                         ext4_fsblk_t block, unsigned long count, int metadata);
1328 extern void ext4_add_groupblocks(handle_t *handle, struct super_block *sb,
1329                                 ext4_fsblk_t block, unsigned long count);
1330 extern ext4_fsblk_t ext4_count_free_blocks(struct super_block *);
1331 extern void ext4_check_blocks_bitmap(struct super_block *);
1332 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1333                                                     ext4_group_t block_group,
1334                                                     struct buffer_head ** bh);
1335 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1336 struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1337                                       ext4_group_t block_group);
1338 extern unsigned ext4_init_block_bitmap(struct super_block *sb,
1339                                        struct buffer_head *bh,
1340                                        ext4_group_t group,
1341                                        struct ext4_group_desc *desc);
1342 #define ext4_free_blocks_after_init(sb, group, desc)                    \
1343                 ext4_init_block_bitmap(sb, NULL, group, desc)
1344
1345 /* dir.c */
1346 extern int ext4_check_dir_entry(const char *, struct inode *,
1347                                 struct ext4_dir_entry_2 *,
1348                                 struct buffer_head *, unsigned int);
1349 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1350                                     __u32 minor_hash,
1351                                     struct ext4_dir_entry_2 *dirent);
1352 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
1353
1354 /* fsync.c */
1355 extern int ext4_sync_file(struct file *, struct dentry *, int);
1356
1357 /* hash.c */
1358 extern int ext4fs_dirhash(const char *name, int len, struct
1359                           dx_hash_info *hinfo);
1360
1361 /* ialloc.c */
1362 extern struct inode *ext4_new_inode(handle_t *, struct inode *, int,
1363                                     const struct qstr *qstr, __u32 goal);
1364 extern void ext4_free_inode(handle_t *, struct inode *);
1365 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
1366 extern unsigned long ext4_count_free_inodes(struct super_block *);
1367 extern unsigned long ext4_count_dirs(struct super_block *);
1368 extern void ext4_check_inodes_bitmap(struct super_block *);
1369 extern unsigned ext4_init_inode_bitmap(struct super_block *sb,
1370                                        struct buffer_head *bh,
1371                                        ext4_group_t group,
1372                                        struct ext4_group_desc *desc);
1373 extern void mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
1374
1375 /* mballoc.c */
1376 extern long ext4_mb_stats;
1377 extern long ext4_mb_max_to_scan;
1378 extern int ext4_mb_init(struct super_block *, int);
1379 extern int ext4_mb_release(struct super_block *);
1380 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
1381                                 struct ext4_allocation_request *, int *);
1382 extern int ext4_mb_reserve_blocks(struct super_block *, int);
1383 extern void ext4_discard_preallocations(struct inode *);
1384 extern int __init init_ext4_mballoc(void);
1385 extern void exit_ext4_mballoc(void);
1386 extern void ext4_mb_free_blocks(handle_t *, struct inode *,
1387                 ext4_fsblk_t, unsigned long, int, unsigned long *);
1388 extern int ext4_mb_add_groupinfo(struct super_block *sb,
1389                 ext4_group_t i, struct ext4_group_desc *desc);
1390 extern int ext4_mb_get_buddy_cache_lock(struct super_block *, ext4_group_t);
1391 extern void ext4_mb_put_buddy_cache_lock(struct super_block *,
1392                                                 ext4_group_t, int);
1393 /* inode.c */
1394 int ext4_forget(handle_t *handle, int is_metadata, struct inode *inode,
1395                 struct buffer_head *bh, ext4_fsblk_t blocknr);
1396 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
1397                                                 ext4_lblk_t, int, int *);
1398 struct buffer_head *ext4_bread(handle_t *, struct inode *,
1399                                                 ext4_lblk_t, int, int *);
1400 int ext4_get_block(struct inode *inode, sector_t iblock,
1401                                 struct buffer_head *bh_result, int create);
1402
1403 extern struct inode *ext4_iget(struct super_block *, unsigned long);
1404 extern int  ext4_write_inode(struct inode *, int);
1405 extern int  ext4_setattr(struct dentry *, struct iattr *);
1406 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
1407                                 struct kstat *stat);
1408 extern void ext4_delete_inode(struct inode *);
1409 extern int  ext4_sync_inode(handle_t *, struct inode *);
1410 extern void ext4_dirty_inode(struct inode *);
1411 extern int ext4_change_inode_journal_flag(struct inode *, int);
1412 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
1413 extern int ext4_can_truncate(struct inode *inode);
1414 extern void ext4_truncate(struct inode *);
1415 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
1416 extern void ext4_set_inode_flags(struct inode *);
1417 extern void ext4_get_inode_flags(struct ext4_inode_info *);
1418 extern int ext4_alloc_da_blocks(struct inode *inode);
1419 extern void ext4_set_aops(struct inode *inode);
1420 extern int ext4_writepage_trans_blocks(struct inode *);
1421 extern int ext4_meta_trans_blocks(struct inode *, int nrblocks, int idxblocks);
1422 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
1423 extern int ext4_block_truncate_page(handle_t *handle,
1424                 struct address_space *mapping, loff_t from);
1425 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
1426 extern qsize_t ext4_get_reserved_space(struct inode *inode);
1427 extern int flush_aio_dio_completed_IO(struct inode *inode);
1428 /* ioctl.c */
1429 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
1430 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
1431
1432 /* migrate.c */
1433 extern int ext4_ext_migrate(struct inode *);
1434
1435 /* namei.c */
1436 extern unsigned int ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize);
1437 extern __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize);
1438 extern int ext4_orphan_add(handle_t *, struct inode *);
1439 extern int ext4_orphan_del(handle_t *, struct inode *);
1440 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1441                                 __u32 start_minor_hash, __u32 *next_hash);
1442
1443 /* resize.c */
1444 extern int ext4_group_add(struct super_block *sb,
1445                                 struct ext4_new_group_data *input);
1446 extern int ext4_group_extend(struct super_block *sb,
1447                                 struct ext4_super_block *es,
1448                                 ext4_fsblk_t n_blocks_count);
1449
1450 /* super.c */
1451 extern void ext4_error(struct super_block *, const char *, const char *, ...)
1452         __attribute__ ((format (printf, 3, 4)));
1453 extern void __ext4_std_error(struct super_block *, const char *, int);
1454 extern void ext4_abort(struct super_block *, const char *, const char *, ...)
1455         __attribute__ ((format (printf, 3, 4)));
1456 extern void ext4_warning(struct super_block *, const char *, const char *, ...)
1457         __attribute__ ((format (printf, 3, 4)));
1458 extern void ext4_msg(struct super_block *, const char *, const char *, ...)
1459         __attribute__ ((format (printf, 3, 4)));
1460 extern void ext4_grp_locked_error(struct super_block *, ext4_group_t,
1461                                 const char *, const char *, ...)
1462         __attribute__ ((format (printf, 4, 5)));
1463 extern void ext4_update_dynamic_rev(struct super_block *sb);
1464 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
1465                                         __u32 compat);
1466 extern int ext4_update_rocompat_feature(handle_t *handle,
1467                                         struct super_block *sb, __u32 rocompat);
1468 extern int ext4_update_incompat_feature(handle_t *handle,
1469                                         struct super_block *sb, __u32 incompat);
1470 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
1471                                       struct ext4_group_desc *bg);
1472 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
1473                                       struct ext4_group_desc *bg);
1474 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
1475                                      struct ext4_group_desc *bg);
1476 extern __u32 ext4_free_blks_count(struct super_block *sb,
1477                                 struct ext4_group_desc *bg);
1478 extern __u32 ext4_free_inodes_count(struct super_block *sb,
1479                                  struct ext4_group_desc *bg);
1480 extern __u32 ext4_used_dirs_count(struct super_block *sb,
1481                                 struct ext4_group_desc *bg);
1482 extern __u32 ext4_itable_unused_count(struct super_block *sb,
1483                                    struct ext4_group_desc *bg);
1484 extern void ext4_block_bitmap_set(struct super_block *sb,
1485                                   struct ext4_group_desc *bg, ext4_fsblk_t blk);
1486 extern void ext4_inode_bitmap_set(struct super_block *sb,
1487                                   struct ext4_group_desc *bg, ext4_fsblk_t blk);
1488 extern void ext4_inode_table_set(struct super_block *sb,
1489                                  struct ext4_group_desc *bg, ext4_fsblk_t blk);
1490 extern void ext4_free_blks_set(struct super_block *sb,
1491                                struct ext4_group_desc *bg, __u32 count);
1492 extern void ext4_free_inodes_set(struct super_block *sb,
1493                                 struct ext4_group_desc *bg, __u32 count);
1494 extern void ext4_used_dirs_set(struct super_block *sb,
1495                                 struct ext4_group_desc *bg, __u32 count);
1496 extern void ext4_itable_unused_set(struct super_block *sb,
1497                                    struct ext4_group_desc *bg, __u32 count);
1498 extern __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 group,
1499                                    struct ext4_group_desc *gdp);
1500 extern int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 group,
1501                                        struct ext4_group_desc *gdp);
1502
1503 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
1504 {
1505         return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
1506                 le32_to_cpu(es->s_blocks_count_lo);
1507 }
1508
1509 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
1510 {
1511         return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
1512                 le32_to_cpu(es->s_r_blocks_count_lo);
1513 }
1514
1515 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
1516 {
1517         return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
1518                 le32_to_cpu(es->s_free_blocks_count_lo);
1519 }
1520
1521 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
1522                                          ext4_fsblk_t blk)
1523 {
1524         es->s_blocks_count_lo = cpu_to_le32((u32)blk);
1525         es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
1526 }
1527
1528 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
1529                                               ext4_fsblk_t blk)
1530 {
1531         es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
1532         es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
1533 }
1534
1535 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
1536                                            ext4_fsblk_t blk)
1537 {
1538         es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
1539         es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
1540 }
1541
1542 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
1543 {
1544         if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
1545                 return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
1546                         le32_to_cpu(raw_inode->i_size_lo);
1547         else
1548                 return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
1549 }
1550
1551 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
1552 {
1553         raw_inode->i_size_lo = cpu_to_le32(i_size);
1554         raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
1555 }
1556
1557 static inline
1558 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
1559                                             ext4_group_t group)
1560 {
1561          struct ext4_group_info ***grp_info;
1562          long indexv, indexh;
1563          grp_info = EXT4_SB(sb)->s_group_info;
1564          indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
1565          indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
1566          return grp_info[indexv][indexh];
1567 }
1568
1569 /*
1570  * Reading s_groups_count requires using smp_rmb() afterwards.  See
1571  * the locking protocol documented in the comments of ext4_group_add()
1572  * in resize.c
1573  */
1574 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
1575 {
1576         ext4_group_t    ngroups = EXT4_SB(sb)->s_groups_count;
1577
1578         smp_rmb();
1579         return ngroups;
1580 }
1581
1582 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
1583                                              ext4_group_t block_group)
1584 {
1585         return block_group >> sbi->s_log_groups_per_flex;
1586 }
1587
1588 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
1589 {
1590         return 1 << sbi->s_log_groups_per_flex;
1591 }
1592
1593 #define ext4_std_error(sb, errno)                               \
1594 do {                                                            \
1595         if ((errno))                                            \
1596                 __ext4_std_error((sb), __func__, (errno));      \
1597 } while (0)
1598
1599 #ifdef CONFIG_SMP
1600 /* Each CPU can accumulate percpu_counter_batch blocks in their local
1601  * counters. So we need to make sure we have free blocks more
1602  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
1603  */
1604 #define EXT4_FREEBLOCKS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
1605 #else
1606 #define EXT4_FREEBLOCKS_WATERMARK 0
1607 #endif
1608
1609 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
1610 {
1611         /*
1612          * XXX: replace with spinlock if seen contended -bzzz
1613          */
1614         down_write(&EXT4_I(inode)->i_data_sem);
1615         if (newsize > EXT4_I(inode)->i_disksize)
1616                 EXT4_I(inode)->i_disksize = newsize;
1617         up_write(&EXT4_I(inode)->i_data_sem);
1618         return ;
1619 }
1620
1621 struct ext4_group_info {
1622         unsigned long   bb_state;
1623         struct rb_root  bb_free_root;
1624         ext4_grpblk_t   bb_first_free;  /* first free block */
1625         ext4_grpblk_t   bb_free;        /* total free blocks */
1626         ext4_grpblk_t   bb_fragments;   /* nr of freespace fragments */
1627         struct          list_head bb_prealloc_list;
1628 #ifdef DOUBLE_CHECK
1629         void            *bb_bitmap;
1630 #endif
1631         struct rw_semaphore alloc_sem;
1632         ext4_grpblk_t   bb_counters[];  /* Nr of free power-of-two-block
1633                                          * regions, index is order.
1634                                          * bb_counters[3] = 5 means
1635                                          * 5 free 8-block regions. */
1636 };
1637
1638 #define EXT4_GROUP_INFO_NEED_INIT_BIT   0
1639
1640 #define EXT4_MB_GRP_NEED_INIT(grp)      \
1641         (test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
1642
1643 #define EXT4_MAX_CONTENTION             8
1644 #define EXT4_CONTENTION_THRESHOLD       2
1645
1646 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
1647                                               ext4_group_t group)
1648 {
1649         return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
1650 }
1651
1652 /*
1653  * Returns true if the filesystem is busy enough that attempts to
1654  * access the block group locks has run into contention.
1655  */
1656 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
1657 {
1658         return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
1659 }
1660
1661 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
1662 {
1663         spinlock_t *lock = ext4_group_lock_ptr(sb, group);
1664         if (spin_trylock(lock))
1665                 /*
1666                  * We're able to grab the lock right away, so drop the
1667                  * lock contention counter.
1668                  */
1669                 atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
1670         else {
1671                 /*
1672                  * The lock is busy, so bump the contention counter,
1673                  * and then wait on the spin lock.
1674                  */
1675                 atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
1676                                   EXT4_MAX_CONTENTION);
1677                 spin_lock(lock);
1678         }
1679 }
1680
1681 static inline void ext4_unlock_group(struct super_block *sb,
1682                                         ext4_group_t group)
1683 {
1684         spin_unlock(ext4_group_lock_ptr(sb, group));
1685 }
1686
1687 /*
1688  * Inodes and files operations
1689  */
1690
1691 /* dir.c */
1692 extern const struct file_operations ext4_dir_operations;
1693
1694 /* file.c */
1695 extern const struct inode_operations ext4_file_inode_operations;
1696 extern const struct file_operations ext4_file_operations;
1697
1698 /* namei.c */
1699 extern const struct inode_operations ext4_dir_inode_operations;
1700 extern const struct inode_operations ext4_special_inode_operations;
1701 extern struct dentry *ext4_get_parent(struct dentry *child);
1702
1703 /* symlink.c */
1704 extern const struct inode_operations ext4_symlink_inode_operations;
1705 extern const struct inode_operations ext4_fast_symlink_inode_operations;
1706
1707 /* block_validity */
1708 extern void ext4_release_system_zone(struct super_block *sb);
1709 extern int ext4_setup_system_zone(struct super_block *sb);
1710 extern int __init init_ext4_system_zone(void);
1711 extern void exit_ext4_system_zone(void);
1712 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
1713                                  ext4_fsblk_t start_blk,
1714                                  unsigned int count);
1715
1716 /* extents.c */
1717 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
1718 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
1719 extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks,
1720                                        int chunk);
1721 extern int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
1722                                ext4_lblk_t iblock, unsigned int max_blocks,
1723                                struct buffer_head *bh_result, int flags);
1724 extern void ext4_ext_truncate(struct inode *);
1725 extern void ext4_ext_init(struct super_block *);
1726 extern void ext4_ext_release(struct super_block *);
1727 extern long ext4_fallocate(struct inode *inode, int mode, loff_t offset,
1728                           loff_t len);
1729 extern int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
1730                           loff_t len);
1731 extern int ext4_get_blocks(handle_t *handle, struct inode *inode,
1732                            sector_t block, unsigned int max_blocks,
1733                            struct buffer_head *bh, int flags);
1734 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
1735                         __u64 start, __u64 len);
1736 /* move_extent.c */
1737 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
1738                              __u64 start_orig, __u64 start_donor,
1739                              __u64 len, __u64 *moved_len);
1740
1741
1742 /*
1743  * Add new method to test wether block and inode bitmaps are properly
1744  * initialized. With uninit_bg reading the block from disk is not enough
1745  * to mark the bitmap uptodate. We need to also zero-out the bitmap
1746  */
1747 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
1748
1749 static inline int bitmap_uptodate(struct buffer_head *bh)
1750 {
1751         return (buffer_uptodate(bh) &&
1752                         test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
1753 }
1754 static inline void set_bitmap_uptodate(struct buffer_head *bh)
1755 {
1756         set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
1757 }
1758
1759 #endif  /* __KERNEL__ */
1760
1761 #endif  /* _EXT4_H */