fs/xfs/xfs_btree.h

   1 /*
   2  * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18 #ifndef __XFS_BTREE_H__
  19 #define __XFS_BTREE_H__
  20
  21 struct xfs_buf;
  22 struct xfs_bmap_free;
  23 struct xfs_inode;
  24 struct xfs_mount;
  25 struct xfs_trans;
  26
  27 extern kmem_zone_t      *xfs_btree_cur_zone;
  28
  29 /*
  30  * This nonsense is to make -wlint happy.
  31  */
  32 #define XFS_LOOKUP_EQ   ((xfs_lookup_t)XFS_LOOKUP_EQi)
  33 #define XFS_LOOKUP_LE   ((xfs_lookup_t)XFS_LOOKUP_LEi)
  34 #define XFS_LOOKUP_GE   ((xfs_lookup_t)XFS_LOOKUP_GEi)
  35
  36 #define XFS_BTNUM_BNO   ((xfs_btnum_t)XFS_BTNUM_BNOi)
  37 #define XFS_BTNUM_CNT   ((xfs_btnum_t)XFS_BTNUM_CNTi)
  38 #define XFS_BTNUM_BMAP  ((xfs_btnum_t)XFS_BTNUM_BMAPi)
  39 #define XFS_BTNUM_INO   ((xfs_btnum_t)XFS_BTNUM_INOi)
  40
  41 /*
  42  * Short form header: space allocation btrees.
  43  */
  44 typedef struct xfs_btree_sblock {
  45         __be32          bb_magic;       /* magic number for block type */
  46         __be16          bb_level;       /* 0 is a leaf */
  47         __be16          bb_numrecs;     /* current # of data records */
  48         __be32          bb_leftsib;     /* left sibling block or NULLAGBLOCK */
  49         __be32          bb_rightsib;    /* right sibling block or NULLAGBLOCK */
  50 } xfs_btree_sblock_t;
  51
  52 /*
  53  * Long form header: bmap btrees.
  54  */
  55 typedef struct xfs_btree_lblock {
  56         __be32          bb_magic;       /* magic number for block type */
  57         __be16          bb_level;       /* 0 is a leaf */
  58         __be16          bb_numrecs;     /* current # of data records */
  59         __be64          bb_leftsib;     /* left sibling block or NULLDFSBNO */
  60         __be64          bb_rightsib;    /* right sibling block or NULLDFSBNO */
  61 } xfs_btree_lblock_t;
  62
  63 /*
  64  * Combined header and structure, used by common code.
  65  */
  66 typedef struct xfs_btree_block {
  67         __be32          bb_magic;       /* magic number for block type */
  68         __be16          bb_level;       /* 0 is a leaf */
  69         __be16          bb_numrecs;     /* current # of data records */
  70         union {
  71                 struct {
  72                         __be32          bb_leftsib;
  73                         __be32          bb_rightsib;
  74                 } s;                    /* short form pointers */
  75                 struct  {
  76                         __be64          bb_leftsib;
  77                         __be64          bb_rightsib;
  78                 } l;                    /* long form pointers */
  79         } bb_u;                         /* rest */
  80 } xfs_btree_block_t;
  81
  82 /*
  83  * Generic key, ptr and record wrapper structures.
  84  *
  85  * These are disk format structures, and are converted where necessary
  86  * by the btree specific code that needs to interpret them.
  87  */
  88 union xfs_btree_ptr {
  89         __be32                  s;      /* short form ptr */
  90         __be64                  l;      /* long form ptr */
  91 };
  92
  93 union xfs_btree_key {
  94         xfs_bmbt_key_t          bmbt;
  95         xfs_bmdr_key_t          bmbr;   /* bmbt root block */
  96         xfs_alloc_key_t         alloc;
  97         xfs_inobt_key_t         inobt;
  98 };
  99
 100 union xfs_btree_rec {
 101         xfs_bmbt_rec_t          bmbt;
 102         xfs_bmdr_rec_t          bmbr;   /* bmbt root block */
 103         xfs_alloc_rec_t         alloc;
 104         xfs_inobt_rec_t         inobt;
 105 };
 106
 107 /*
 108  * For logging record fields.
 109  */
 110 #define XFS_BB_MAGIC            0x01
 111 #define XFS_BB_LEVEL            0x02
 112 #define XFS_BB_NUMRECS          0x04
 113 #define XFS_BB_LEFTSIB          0x08
 114 #define XFS_BB_RIGHTSIB         0x10
 115 #define XFS_BB_NUM_BITS         5
 116 #define XFS_BB_ALL_BITS         ((1 << XFS_BB_NUM_BITS) - 1)
 117
 118 /*
 119  * Magic numbers for btree blocks.
 120  */
 121 extern const __uint32_t xfs_magics[];
 122
 123 /*
 124  * Generic stats interface
 125  */
 126 #define __XFS_BTREE_STATS_INC(type, stat) \
 127         XFS_STATS_INC(xs_ ## type ## _2_ ## stat)
 128 #define XFS_BTREE_STATS_INC(cur, stat)  \
 129 do {    \
 130         switch (cur->bc_btnum) {  \
 131         case XFS_BTNUM_BNO: __XFS_BTREE_STATS_INC(abtb, stat); break;   \
 132         case XFS_BTNUM_CNT: __XFS_BTREE_STATS_INC(abtc, stat); break;   \
 133         case XFS_BTNUM_BMAP: __XFS_BTREE_STATS_INC(bmbt, stat); break;  \
 134         case XFS_BTNUM_INO: __XFS_BTREE_STATS_INC(ibt, stat); break;    \
 135         case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break;       \
 136         }       \
 137 } while (0)
 138
 139 #define __XFS_BTREE_STATS_ADD(type, stat, val) \
 140         XFS_STATS_ADD(xs_ ## type ## _2_ ## stat, val)
 141 #define XFS_BTREE_STATS_ADD(cur, stat, val)  \
 142 do {    \
 143         switch (cur->bc_btnum) {  \
 144         case XFS_BTNUM_BNO: __XFS_BTREE_STATS_ADD(abtb, stat, val); break; \
 145         case XFS_BTNUM_CNT: __XFS_BTREE_STATS_ADD(abtc, stat, val); break; \
 146         case XFS_BTNUM_BMAP: __XFS_BTREE_STATS_ADD(bmbt, stat, val); break; \
 147         case XFS_BTNUM_INO: __XFS_BTREE_STATS_ADD(ibt, stat, val); break; \
 148         case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break;       \
 149         }       \
 150 } while (0)
 151
 152 /*
 153  * Record, key, and pointer address calculation macros.
 154  * Given block size, type prefix, block pointer, and index of requested entry
 155  * (first entry numbered 1).
 156  */
 157 #define XFS_BTREE_REC_ADDR(t,bb,i)      \
 158         ((t ## _rec_t *)((char *)(bb) + sizeof(t ## _block_t) + \
 159          ((i) - 1) * sizeof(t ## _rec_t)))
 160 #define XFS_BTREE_KEY_ADDR(t,bb,i)      \
 161         ((t ## _key_t *)((char *)(bb) + sizeof(t ## _block_t) + \
 162          ((i) - 1) * sizeof(t ## _key_t)))
 163 #define XFS_BTREE_PTR_ADDR(t,bb,i,mxr)  \
 164         ((t ## _ptr_t *)((char *)(bb) + sizeof(t ## _block_t) + \
 165          (mxr) * sizeof(t ## _key_t) + ((i) - 1) * sizeof(t ## _ptr_t)))
 166
 167 #define XFS_BTREE_MAXLEVELS     8       /* max of all btrees */
 168
 169 struct xfs_btree_ops {
 170         /* size of the key and record structures */
 171         size_t  key_len;
 172         size_t  rec_len;
 173
 174         /* cursor operations */
 175         struct xfs_btree_cur *(*dup_cursor)(struct xfs_btree_cur *);
 176         void    (*update_cursor)(struct xfs_btree_cur *src,
 177                                  struct xfs_btree_cur *dst);
 178
 179         /* update btree root pointer */
 180         void    (*set_root)(struct xfs_btree_cur *cur,
 181                                 union xfs_btree_ptr *nptr, int level_change);
 182         int     (*kill_root)(struct xfs_btree_cur *cur, struct xfs_buf *bp,
 183                                 int level, union xfs_btree_ptr *newroot);
 184
 185         /* block allocation / freeing */
 186         int     (*alloc_block)(struct xfs_btree_cur *cur,
 187                                union xfs_btree_ptr *start_bno,
 188                                union xfs_btree_ptr *new_bno,
 189                                int length, int *stat);
 190         int     (*free_block)(struct xfs_btree_cur *cur, struct xfs_buf *bp);
 191
 192         /* update last record information */
 193         void    (*update_lastrec)(struct xfs_btree_cur *cur,
 194                                   struct xfs_btree_block *block,
 195                                   union xfs_btree_rec *rec,
 196                                   int ptr, int reason);
 197
 198         /* records in block/level */
 199         int     (*get_minrecs)(struct xfs_btree_cur *cur, int level);
 200         int     (*get_maxrecs)(struct xfs_btree_cur *cur, int level);
 201
 202         /* records on disk.  Matter for the root in inode case. */
 203         int     (*get_dmaxrecs)(struct xfs_btree_cur *cur, int level);
 204
 205         /* init values of btree structures */
 206         void    (*init_key_from_rec)(union xfs_btree_key *key,
 207                                      union xfs_btree_rec *rec);
 208         void    (*init_rec_from_key)(union xfs_btree_key *key,
 209                                      union xfs_btree_rec *rec);
 210         void    (*init_rec_from_cur)(struct xfs_btree_cur *cur,
 211                                      union xfs_btree_rec *rec);
 212         void    (*init_ptr_from_cur)(struct xfs_btree_cur *cur,
 213                                      union xfs_btree_ptr *ptr);
 214
 215         /* difference between key value and cursor value */
 216         __int64_t (*key_diff)(struct xfs_btree_cur *cur,
 217                               union xfs_btree_key *key);
 218
 219 #ifdef DEBUG
 220         /* check that k1 is lower than k2 */
 221         int     (*keys_inorder)(struct xfs_btree_cur *cur,
 222                                 union xfs_btree_key *k1,
 223                                 union xfs_btree_key *k2);
 224
 225         /* check that r1 is lower than r2 */
 226         int     (*recs_inorder)(struct xfs_btree_cur *cur,
 227                                 union xfs_btree_rec *r1,
 228                                 union xfs_btree_rec *r2);
 229 #endif
 230
 231         /* btree tracing */
 232 #ifdef XFS_BTREE_TRACE
 233         void            (*trace_enter)(struct xfs_btree_cur *, const char *,
 234                                        char *, int, int, __psunsigned_t,
 235                                        __psunsigned_t, __psunsigned_t,
 236                                        __psunsigned_t, __psunsigned_t,
 237                                        __psunsigned_t, __psunsigned_t,
 238                                        __psunsigned_t, __psunsigned_t,
 239                                        __psunsigned_t, __psunsigned_t);
 240         void            (*trace_cursor)(struct xfs_btree_cur *, __uint32_t *,
 241                                         __uint64_t *, __uint64_t *);
 242         void            (*trace_key)(struct xfs_btree_cur *,
 243                                      union xfs_btree_key *, __uint64_t *,
 244                                      __uint64_t *);
 245         void            (*trace_record)(struct xfs_btree_cur *,
 246                                         union xfs_btree_rec *, __uint64_t *,
 247                                         __uint64_t *, __uint64_t *);
 248 #endif
 249 };
 250
 251 /*
 252  * Reasons for the update_lastrec method to be called.
 253  */
 254 #define LASTREC_UPDATE  0
 255 #define LASTREC_INSREC  1
 256 #define LASTREC_DELREC  2
 257
 258
 259 /*
 260  * Btree cursor structure.
 261  * This collects all information needed by the btree code in one place.
 262  */
 263 typedef struct xfs_btree_cur
 264 {
 265         struct xfs_trans        *bc_tp; /* transaction we're in, if any */
 266         struct xfs_mount        *bc_mp; /* file system mount struct */
 267         const struct xfs_btree_ops *bc_ops;
 268         uint                    bc_flags; /* btree features - below */
 269         union {
 270                 xfs_alloc_rec_incore_t  a;
 271                 xfs_bmbt_irec_t         b;
 272                 xfs_inobt_rec_incore_t  i;
 273         }               bc_rec;         /* current insert/search record value */
 274         struct xfs_buf  *bc_bufs[XFS_BTREE_MAXLEVELS];  /* buf ptr per level */
 275         int             bc_ptrs[XFS_BTREE_MAXLEVELS];   /* key/record # */
 276         __uint8_t       bc_ra[XFS_BTREE_MAXLEVELS];     /* readahead bits */
 277 #define XFS_BTCUR_LEFTRA        1       /* left sibling has been read-ahead */
 278 #define XFS_BTCUR_RIGHTRA       2       /* right sibling has been read-ahead */
 279         __uint8_t       bc_nlevels;     /* number of levels in the tree */
 280         __uint8_t       bc_blocklog;    /* log2(blocksize) of btree blocks */
 281         xfs_btnum_t     bc_btnum;       /* identifies which btree type */
 282         union {
 283                 struct {                        /* needed for BNO, CNT, INO */
 284                         struct xfs_buf  *agbp;  /* agf/agi buffer pointer */
 285                         xfs_agnumber_t  agno;   /* ag number */
 286                 } a;
 287                 struct {                        /* needed for BMAP */
 288                         struct xfs_inode *ip;   /* pointer to our inode */
 289                         struct xfs_bmap_free *flist;    /* list to free after */
 290                         xfs_fsblock_t   firstblock;     /* 1st blk allocated */
 291                         int             allocated;      /* count of alloced */
 292                         short           forksize;       /* fork's inode space */
 293                         char            whichfork;      /* data or attr fork */
 294                         char            flags;          /* flags */
 295 #define XFS_BTCUR_BPRV_WASDEL   1                       /* was delayed */
 296                 } b;
 297         }               bc_private;     /* per-btree type data */
 298 } xfs_btree_cur_t;
 299
 300 /* cursor flags */
 301 #define XFS_BTREE_LONG_PTRS             (1<<0)  /* pointers are 64bits long */
 302 #define XFS_BTREE_ROOT_IN_INODE         (1<<1)  /* root may be variable size */
 303 #define XFS_BTREE_LASTREC_UPDATE        (1<<2)  /* track last rec externally */
 304
 305
 306 #define XFS_BTREE_NOERROR       0
 307 #define XFS_BTREE_ERROR         1
 308
 309 /*
 310  * Convert from buffer to btree block header.
 311  */
 312 #define XFS_BUF_TO_BLOCK(bp)    ((xfs_btree_block_t *)XFS_BUF_PTR(bp))
 313 #define XFS_BUF_TO_LBLOCK(bp)   ((xfs_btree_lblock_t *)XFS_BUF_PTR(bp))
 314 #define XFS_BUF_TO_SBLOCK(bp)   ((xfs_btree_sblock_t *)XFS_BUF_PTR(bp))
 315
 316
 317 /*
 318  * Check that long form block header is ok.
 319  */
 320 int                                     /* error (0 or EFSCORRUPTED) */
 321 xfs_btree_check_lblock(
 322         struct xfs_btree_cur    *cur,   /* btree cursor */
 323         struct xfs_btree_lblock *block, /* btree long form block pointer */
 324         int                     level,  /* level of the btree block */
 325         struct xfs_buf          *bp);   /* buffer containing block, if any */
 326
 327 /*
 328  * Check that block header is ok.
 329  */
 330 int
 331 xfs_btree_check_block(
 332         struct xfs_btree_cur    *cur,   /* btree cursor */
 333         struct xfs_btree_block  *block, /* generic btree block pointer */
 334         int                     level,  /* level of the btree block */
 335         struct xfs_buf          *bp);   /* buffer containing block, if any */
 336
 337 /*
 338  * Check that (long) pointer is ok.
 339  */
 340 int                                     /* error (0 or EFSCORRUPTED) */
 341 xfs_btree_check_lptr(
 342         struct xfs_btree_cur    *cur,   /* btree cursor */
 343         xfs_dfsbno_t            ptr,    /* btree block disk address */
 344         int                     level); /* btree block level */
 345
 346 /*
 347  * Delete the btree cursor.
 348  */
 349 void
 350 xfs_btree_del_cursor(
 351         xfs_btree_cur_t         *cur,   /* btree cursor */
 352         int                     error); /* del because of error */
 353
 354 /*
 355  * Duplicate the btree cursor.
 356  * Allocate a new one, copy the record, re-get the buffers.
 357  */
 358 int                                     /* error */
 359 xfs_btree_dup_cursor(
 360         xfs_btree_cur_t         *cur,   /* input cursor */
 361         xfs_btree_cur_t         **ncur);/* output cursor */
 362
 363 /*
 364  * Get a buffer for the block, return it with no data read.
 365  * Long-form addressing.
 366  */
 367 struct xfs_buf *                                /* buffer for fsbno */
 368 xfs_btree_get_bufl(
 369         struct xfs_mount        *mp,    /* file system mount point */
 370         struct xfs_trans        *tp,    /* transaction pointer */
 371         xfs_fsblock_t           fsbno,  /* file system block number */
 372         uint                    lock);  /* lock flags for get_buf */
 373
 374 /*
 375  * Get a buffer for the block, return it with no data read.
 376  * Short-form addressing.
 377  */
 378 struct xfs_buf *                                /* buffer for agno/agbno */
 379 xfs_btree_get_bufs(
 380         struct xfs_mount        *mp,    /* file system mount point */
 381         struct xfs_trans        *tp,    /* transaction pointer */
 382         xfs_agnumber_t          agno,   /* allocation group number */
 383         xfs_agblock_t           agbno,  /* allocation group block number */
 384         uint                    lock);  /* lock flags for get_buf */
 385
 386 /*
 387  * Check for the cursor referring to the last block at the given level.
 388  */
 389 int                                     /* 1=is last block, 0=not last block */
 390 xfs_btree_islastblock(
 391         xfs_btree_cur_t         *cur,   /* btree cursor */
 392         int                     level); /* level to check */
 393
 394 /*
 395  * Compute first and last byte offsets for the fields given.
 396  * Interprets the offsets table, which contains struct field offsets.
 397  */
 398 void
 399 xfs_btree_offsets(
 400         __int64_t               fields, /* bitmask of fields */
 401         const short             *offsets,/* table of field offsets */
 402         int                     nbits,  /* number of bits to inspect */
 403         int                     *first, /* output: first byte offset */
 404         int                     *last); /* output: last byte offset */
 405
 406 /*
 407  * Get a buffer for the block, return it read in.
 408  * Long-form addressing.
 409  */
 410 int                                     /* error */
 411 xfs_btree_read_bufl(
 412         struct xfs_mount        *mp,    /* file system mount point */
 413         struct xfs_trans        *tp,    /* transaction pointer */
 414         xfs_fsblock_t           fsbno,  /* file system block number */
 415         uint                    lock,   /* lock flags for read_buf */
 416         struct xfs_buf          **bpp,  /* buffer for fsbno */
 417         int                     refval);/* ref count value for buffer */
 418
 419 /*
 420  * Get a buffer for the block, return it read in.
 421  * Short-form addressing.
 422  */
 423 int                                     /* error */
 424 xfs_btree_read_bufs(
 425         struct xfs_mount        *mp,    /* file system mount point */
 426         struct xfs_trans        *tp,    /* transaction pointer */
 427         xfs_agnumber_t          agno,   /* allocation group number */
 428         xfs_agblock_t           agbno,  /* allocation group block number */
 429         uint                    lock,   /* lock flags for read_buf */
 430         struct xfs_buf          **bpp,  /* buffer for agno/agbno */
 431         int                     refval);/* ref count value for buffer */
 432
 433 /*
 434  * Read-ahead the block, don't wait for it, don't return a buffer.
 435  * Long-form addressing.
 436  */
 437 void                                    /* error */
 438 xfs_btree_reada_bufl(
 439         struct xfs_mount        *mp,    /* file system mount point */
 440         xfs_fsblock_t           fsbno,  /* file system block number */
 441         xfs_extlen_t            count); /* count of filesystem blocks */
 442
 443 /*
 444  * Read-ahead the block, don't wait for it, don't return a buffer.
 445  * Short-form addressing.
 446  */
 447 void                                    /* error */
 448 xfs_btree_reada_bufs(
 449         struct xfs_mount        *mp,    /* file system mount point */
 450         xfs_agnumber_t          agno,   /* allocation group number */
 451         xfs_agblock_t           agbno,  /* allocation group block number */
 452         xfs_extlen_t            count); /* count of filesystem blocks */
 453
 454 /*
 455  * Set the buffer for level "lev" in the cursor to bp, releasing
 456  * any previous buffer.
 457  */
 458 void
 459 xfs_btree_setbuf(
 460         xfs_btree_cur_t         *cur,   /* btree cursor */
 461         int                     lev,    /* level in btree */
 462         struct xfs_buf          *bp);   /* new buffer to set */
 463
 464
 465 /*
 466  * Common btree core entry points.
 467  */
 468 int xfs_btree_increment(struct xfs_btree_cur *, int, int *);
 469 int xfs_btree_decrement(struct xfs_btree_cur *, int, int *);
 470 int xfs_btree_lookup(struct xfs_btree_cur *, xfs_lookup_t, int *);
 471 int xfs_btree_update(struct xfs_btree_cur *, union xfs_btree_rec *);
 472 int xfs_btree_new_iroot(struct xfs_btree_cur *, int *, int *);
 473 int xfs_btree_kill_iroot(struct xfs_btree_cur *);
 474 int xfs_btree_insert(struct xfs_btree_cur *, int *);
 475 int xfs_btree_delete(struct xfs_btree_cur *, int *);
 476 int xfs_btree_get_rec(struct xfs_btree_cur *, union xfs_btree_rec **, int *);
 477
 478 /*
 479  * Internal btree helpers also used by xfs_bmap.c.
 480  */
 481 void xfs_btree_log_block(struct xfs_btree_cur *, struct xfs_buf *, int);
 482 void xfs_btree_log_recs(struct xfs_btree_cur *, struct xfs_buf *, int, int);
 483
 484 /*
 485  * Helpers.
 486  */
 487 static inline int xfs_btree_get_numrecs(struct xfs_btree_block *block)
 488 {
 489         return be16_to_cpu(block->bb_numrecs);
 490 }
 491
 492 static inline void xfs_btree_set_numrecs(struct xfs_btree_block *block,
 493                 __uint16_t numrecs)
 494 {
 495         block->bb_numrecs = cpu_to_be16(numrecs);
 496 }
 497
 498 static inline int xfs_btree_get_level(struct xfs_btree_block *block)
 499 {
 500         return be16_to_cpu(block->bb_level);
 501 }
 502
 503
 504 /*
 505  * Min and max functions for extlen, agblock, fileoff, and filblks types.
 506  */
 507 #define XFS_EXTLEN_MIN(a,b)     min_t(xfs_extlen_t, (a), (b))
 508 #define XFS_EXTLEN_MAX(a,b)     max_t(xfs_extlen_t, (a), (b))
 509 #define XFS_AGBLOCK_MIN(a,b)    min_t(xfs_agblock_t, (a), (b))
 510 #define XFS_AGBLOCK_MAX(a,b)    max_t(xfs_agblock_t, (a), (b))
 511 #define XFS_FILEOFF_MIN(a,b)    min_t(xfs_fileoff_t, (a), (b))
 512 #define XFS_FILEOFF_MAX(a,b)    max_t(xfs_fileoff_t, (a), (b))
 513 #define XFS_FILBLKS_MIN(a,b)    min_t(xfs_filblks_t, (a), (b))
 514 #define XFS_FILBLKS_MAX(a,b)    max_t(xfs_filblks_t, (a), (b))
 515
 516 #define XFS_FSB_SANITY_CHECK(mp,fsb)    \
 517         (XFS_FSB_TO_AGNO(mp, fsb) < mp->m_sb.sb_agcount && \
 518                 XFS_FSB_TO_AGBNO(mp, fsb) < mp->m_sb.sb_agblocks)
 519
 520 #endif  /* __XFS_BTREE_H__ */