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  * Maximum and minimum records in a btree block.
 153  * Given block size, type prefix, and leaf flag (0 or 1).
 154  * The divisor below is equivalent to lf ? (e1) : (e2) but that produces
 155  * compiler warnings.
 156  */
 157 #define XFS_BTREE_BLOCK_MAXRECS(bsz,t,lf)       \
 158         ((int)(((bsz) - (uint)sizeof(t ## _block_t)) / \
 159          (((lf) * (uint)sizeof(t ## _rec_t)) + \
 160           ((1 - (lf)) * \
 161            ((uint)sizeof(t ## _key_t) + (uint)sizeof(t ## _ptr_t))))))
 162 #define XFS_BTREE_BLOCK_MINRECS(bsz,t,lf)       \
 163         (XFS_BTREE_BLOCK_MAXRECS(bsz,t,lf) / 2)
 164
 165 /*
 166  * Record, key, and pointer address calculation macros.
 167  * Given block size, type prefix, block pointer, and index of requested entry
 168  * (first entry numbered 1).
 169  */
 170 #define XFS_BTREE_REC_ADDR(t,bb,i)      \
 171         ((t ## _rec_t *)((char *)(bb) + sizeof(t ## _block_t) + \
 172          ((i) - 1) * sizeof(t ## _rec_t)))
 173 #define XFS_BTREE_KEY_ADDR(t,bb,i)      \
 174         ((t ## _key_t *)((char *)(bb) + sizeof(t ## _block_t) + \
 175          ((i) - 1) * sizeof(t ## _key_t)))
 176 #define XFS_BTREE_PTR_ADDR(t,bb,i,mxr)  \
 177         ((t ## _ptr_t *)((char *)(bb) + sizeof(t ## _block_t) + \
 178          (mxr) * sizeof(t ## _key_t) + ((i) - 1) * sizeof(t ## _ptr_t)))
 179
 180 #define XFS_BTREE_MAXLEVELS     8       /* max of all btrees */
 181
 182 struct xfs_btree_ops {
 183         /* size of the key and record structures */
 184         size_t  key_len;
 185         size_t  rec_len;
 186
 187         /* cursor operations */
 188         struct xfs_btree_cur *(*dup_cursor)(struct xfs_btree_cur *);
 189         void    (*update_cursor)(struct xfs_btree_cur *src,
 190                                  struct xfs_btree_cur *dst);
 191
 192         /* update btree root pointer */
 193         void    (*set_root)(struct xfs_btree_cur *cur,
 194                                 union xfs_btree_ptr *nptr, int level_change);
 195         int     (*kill_root)(struct xfs_btree_cur *cur, struct xfs_buf *bp,
 196                                 int level, union xfs_btree_ptr *newroot);
 197
 198         /* block allocation / freeing */
 199         int     (*alloc_block)(struct xfs_btree_cur *cur,
 200                                union xfs_btree_ptr *start_bno,
 201                                union xfs_btree_ptr *new_bno,
 202                                int length, int *stat);
 203         int     (*free_block)(struct xfs_btree_cur *cur, struct xfs_buf *bp);
 204
 205         /* update last record information */
 206         void    (*update_lastrec)(struct xfs_btree_cur *cur,
 207                                   struct xfs_btree_block *block,
 208                                   union xfs_btree_rec *rec,
 209                                   int ptr, int reason);
 210
 211         /* records in block/level */
 212         int     (*get_minrecs)(struct xfs_btree_cur *cur, int level);
 213         int     (*get_maxrecs)(struct xfs_btree_cur *cur, int level);
 214
 215         /* records on disk.  Matter for the root in inode case. */
 216         int     (*get_dmaxrecs)(struct xfs_btree_cur *cur, int level);
 217
 218         /* init values of btree structures */
 219         void    (*init_key_from_rec)(union xfs_btree_key *key,
 220                                      union xfs_btree_rec *rec);
 221         void    (*init_rec_from_key)(union xfs_btree_key *key,
 222                                      union xfs_btree_rec *rec);
 223         void    (*init_rec_from_cur)(struct xfs_btree_cur *cur,
 224                                      union xfs_btree_rec *rec);
 225         void    (*init_ptr_from_cur)(struct xfs_btree_cur *cur,
 226                                      union xfs_btree_ptr *ptr);
 227
 228         /* difference between key value and cursor value */
 229         __int64_t (*key_diff)(struct xfs_btree_cur *cur,
 230                               union xfs_btree_key *key);
 231
 232         /* btree tracing */
 233 #ifdef XFS_BTREE_TRACE
 234         void            (*trace_enter)(struct xfs_btree_cur *, const char *,
 235                                        char *, int, int, __psunsigned_t,
 236                                        __psunsigned_t, __psunsigned_t,
 237                                        __psunsigned_t, __psunsigned_t,
 238                                        __psunsigned_t, __psunsigned_t,
 239                                        __psunsigned_t, __psunsigned_t,
 240                                        __psunsigned_t, __psunsigned_t);
 241         void            (*trace_cursor)(struct xfs_btree_cur *, __uint32_t *,
 242                                         __uint64_t *, __uint64_t *);
 243         void            (*trace_key)(struct xfs_btree_cur *,
 244                                      union xfs_btree_key *, __uint64_t *,
 245                                      __uint64_t *);
 246         void            (*trace_record)(struct xfs_btree_cur *,
 247                                         union xfs_btree_rec *, __uint64_t *,
 248                                         __uint64_t *, __uint64_t *);
 249 #endif
 250 };
 251
 252 /*
 253  * Reasons for the update_lastrec method to be called.
 254  */
 255 #define LASTREC_UPDATE  0
 256 #define LASTREC_INSREC  1
 257 #define LASTREC_DELREC  2
 258
 259
 260 /*
 261  * Btree cursor structure.
 262  * This collects all information needed by the btree code in one place.
 263  */
 264 typedef struct xfs_btree_cur
 265 {
 266         struct xfs_trans        *bc_tp; /* transaction we're in, if any */
 267         struct xfs_mount        *bc_mp; /* file system mount struct */
 268         const struct xfs_btree_ops *bc_ops;
 269         uint                    bc_flags; /* btree features - below */
 270         union {
 271                 xfs_alloc_rec_incore_t  a;
 272                 xfs_bmbt_irec_t         b;
 273                 xfs_inobt_rec_incore_t  i;
 274         }               bc_rec;         /* current insert/search record value */
 275         struct xfs_buf  *bc_bufs[XFS_BTREE_MAXLEVELS];  /* buf ptr per level */
 276         int             bc_ptrs[XFS_BTREE_MAXLEVELS];   /* key/record # */
 277         __uint8_t       bc_ra[XFS_BTREE_MAXLEVELS];     /* readahead bits */
 278 #define XFS_BTCUR_LEFTRA        1       /* left sibling has been read-ahead */
 279 #define XFS_BTCUR_RIGHTRA       2       /* right sibling has been read-ahead */
 280         __uint8_t       bc_nlevels;     /* number of levels in the tree */
 281         __uint8_t       bc_blocklog;    /* log2(blocksize) of btree blocks */
 282         xfs_btnum_t     bc_btnum;       /* identifies which btree type */
 283         union {
 284                 struct {                        /* needed for BNO, CNT, INO */
 285                         struct xfs_buf  *agbp;  /* agf/agi buffer pointer */
 286                         xfs_agnumber_t  agno;   /* ag number */
 287                 } a;
 288                 struct {                        /* needed for BMAP */
 289                         struct xfs_inode *ip;   /* pointer to our inode */
 290                         struct xfs_bmap_free *flist;    /* list to free after */
 291                         xfs_fsblock_t   firstblock;     /* 1st blk allocated */
 292                         int             allocated;      /* count of alloced */
 293                         short           forksize;       /* fork's inode space */
 294                         char            whichfork;      /* data or attr fork */
 295                         char            flags;          /* flags */
 296 #define XFS_BTCUR_BPRV_WASDEL   1                       /* was delayed */
 297                 } b;
 298         }               bc_private;     /* per-btree type data */
 299 } xfs_btree_cur_t;
 300
 301 /* cursor flags */
 302 #define XFS_BTREE_LONG_PTRS             (1<<0)  /* pointers are 64bits long */
 303 #define XFS_BTREE_ROOT_IN_INODE         (1<<1)  /* root may be variable size */
 304 #define XFS_BTREE_LASTREC_UPDATE        (1<<2)  /* track last rec externally */
 305
 306
 307 #define XFS_BTREE_NOERROR       0
 308 #define XFS_BTREE_ERROR         1
 309
 310 /*
 311  * Convert from buffer to btree block header.
 312  */
 313 #define XFS_BUF_TO_BLOCK(bp)    ((xfs_btree_block_t *)XFS_BUF_PTR(bp))
 314 #define XFS_BUF_TO_LBLOCK(bp)   ((xfs_btree_lblock_t *)XFS_BUF_PTR(bp))
 315 #define XFS_BUF_TO_SBLOCK(bp)   ((xfs_btree_sblock_t *)XFS_BUF_PTR(bp))
 316
 317
 318 #ifdef __KERNEL__
 319
 320 /*
 321  * Check that long form block header is ok.
 322  */
 323 int                                     /* error (0 or EFSCORRUPTED) */
 324 xfs_btree_check_lblock(
 325         struct xfs_btree_cur    *cur,   /* btree cursor */
 326         struct xfs_btree_lblock *block, /* btree long form block pointer */
 327         int                     level,  /* level of the btree block */
 328         struct xfs_buf          *bp);   /* buffer containing block, if any */
 329
 330 /*
 331  * Check that short form block header is ok.
 332  */
 333 int                                     /* error (0 or EFSCORRUPTED) */
 334 xfs_btree_check_sblock(
 335         struct xfs_btree_cur    *cur,   /* btree cursor */
 336         struct xfs_btree_sblock *block, /* btree short form block pointer */
 337         int                     level,  /* level of the btree block */
 338         struct xfs_buf          *bp);   /* buffer containing block */
 339
 340 /*
 341  * Check that block header is ok.
 342  */
 343 int
 344 xfs_btree_check_block(
 345         struct xfs_btree_cur    *cur,   /* btree cursor */
 346         struct xfs_btree_block  *block, /* generic btree block pointer */
 347         int                     level,  /* level of the btree block */
 348         struct xfs_buf          *bp);   /* buffer containing block, if any */
 349
 350 /*
 351  * Check that (long) pointer is ok.
 352  */
 353 int                                     /* error (0 or EFSCORRUPTED) */
 354 xfs_btree_check_lptr(
 355         struct xfs_btree_cur    *cur,   /* btree cursor */
 356         xfs_dfsbno_t            ptr,    /* btree block disk address */
 357         int                     level); /* btree block level */
 358
 359 #define xfs_btree_check_lptr_disk(cur, ptr, level) \
 360         xfs_btree_check_lptr(cur, be64_to_cpu(ptr), level)
 361
 362
 363 /*
 364  * Check that (short) pointer is ok.
 365  */
 366 int                                     /* error (0 or EFSCORRUPTED) */
 367 xfs_btree_check_sptr(
 368         struct xfs_btree_cur    *cur,   /* btree cursor */
 369         xfs_agblock_t           ptr,    /* btree block disk address */
 370         int                     level); /* btree block level */
 371
 372 /*
 373  * Check that (short) pointer is ok.
 374  */
 375 int                                     /* error (0 or EFSCORRUPTED) */
 376 xfs_btree_check_ptr(
 377         struct xfs_btree_cur    *cur,   /* btree cursor */
 378         union xfs_btree_ptr     *ptr,   /* btree block disk address */
 379         int                     index,  /* offset from ptr to check */
 380         int                     level); /* btree block level */
 381
 382 #ifdef DEBUG
 383
 384 /*
 385  * Debug routine: check that keys are in the right order.
 386  */
 387 void
 388 xfs_btree_check_key(
 389         xfs_btnum_t             btnum,  /* btree identifier */
 390         void                    *ak1,   /* pointer to left (lower) key */
 391         void                    *ak2);  /* pointer to right (higher) key */
 392
 393 /*
 394  * Debug routine: check that records are in the right order.
 395  */
 396 void
 397 xfs_btree_check_rec(
 398         xfs_btnum_t             btnum,  /* btree identifier */
 399         void                    *ar1,   /* pointer to left (lower) record */
 400         void                    *ar2);  /* pointer to right (higher) record */
 401 #else
 402 #define xfs_btree_check_key(a, b, c)
 403 #define xfs_btree_check_rec(a, b, c)
 404 #endif  /* DEBUG */
 405
 406 /*
 407  * Delete the btree cursor.
 408  */
 409 void
 410 xfs_btree_del_cursor(
 411         xfs_btree_cur_t         *cur,   /* btree cursor */
 412         int                     error); /* del because of error */
 413
 414 /*
 415  * Duplicate the btree cursor.
 416  * Allocate a new one, copy the record, re-get the buffers.
 417  */
 418 int                                     /* error */
 419 xfs_btree_dup_cursor(
 420         xfs_btree_cur_t         *cur,   /* input cursor */
 421         xfs_btree_cur_t         **ncur);/* output cursor */
 422
 423 /*
 424  * Change the cursor to point to the first record in the current block
 425  * at the given level.  Other levels are unaffected.
 426  */
 427 int                                     /* success=1, failure=0 */
 428 xfs_btree_firstrec(
 429         xfs_btree_cur_t         *cur,   /* btree cursor */
 430         int                     level); /* level to change */
 431
 432 /*
 433  * Get a buffer for the block, return it with no data read.
 434  * Long-form addressing.
 435  */
 436 struct xfs_buf *                                /* buffer for fsbno */
 437 xfs_btree_get_bufl(
 438         struct xfs_mount        *mp,    /* file system mount point */
 439         struct xfs_trans        *tp,    /* transaction pointer */
 440         xfs_fsblock_t           fsbno,  /* file system block number */
 441         uint                    lock);  /* lock flags for get_buf */
 442
 443 /*
 444  * Get a buffer for the block, return it with no data read.
 445  * Short-form addressing.
 446  */
 447 struct xfs_buf *                                /* buffer for agno/agbno */
 448 xfs_btree_get_bufs(
 449         struct xfs_mount        *mp,    /* file system mount point */
 450         struct xfs_trans        *tp,    /* transaction pointer */
 451         xfs_agnumber_t          agno,   /* allocation group number */
 452         xfs_agblock_t           agbno,  /* allocation group block number */
 453         uint                    lock);  /* lock flags for get_buf */
 454
 455 /*
 456  * Check for the cursor referring to the last block at the given level.
 457  */
 458 int                                     /* 1=is last block, 0=not last block */
 459 xfs_btree_islastblock(
 460         xfs_btree_cur_t         *cur,   /* btree cursor */
 461         int                     level); /* level to check */
 462
 463 /*
 464  * Change the cursor to point to the last record in the current block
 465  * at the given level.  Other levels are unaffected.
 466  */
 467 int                                     /* success=1, failure=0 */
 468 xfs_btree_lastrec(
 469         xfs_btree_cur_t         *cur,   /* btree cursor */
 470         int                     level); /* level to change */
 471
 472 /*
 473  * Compute first and last byte offsets for the fields given.
 474  * Interprets the offsets table, which contains struct field offsets.
 475  */
 476 void
 477 xfs_btree_offsets(
 478         __int64_t               fields, /* bitmask of fields */
 479         const short             *offsets,/* table of field offsets */
 480         int                     nbits,  /* number of bits to inspect */
 481         int                     *first, /* output: first byte offset */
 482         int                     *last); /* output: last byte offset */
 483
 484 /*
 485  * Get a buffer for the block, return it read in.
 486  * Long-form addressing.
 487  */
 488 int                                     /* error */
 489 xfs_btree_read_bufl(
 490         struct xfs_mount        *mp,    /* file system mount point */
 491         struct xfs_trans        *tp,    /* transaction pointer */
 492         xfs_fsblock_t           fsbno,  /* file system block number */
 493         uint                    lock,   /* lock flags for read_buf */
 494         struct xfs_buf          **bpp,  /* buffer for fsbno */
 495         int                     refval);/* ref count value for buffer */
 496
 497 /*
 498  * Get a buffer for the block, return it read in.
 499  * Short-form addressing.
 500  */
 501 int                                     /* error */
 502 xfs_btree_read_bufs(
 503         struct xfs_mount        *mp,    /* file system mount point */
 504         struct xfs_trans        *tp,    /* transaction pointer */
 505         xfs_agnumber_t          agno,   /* allocation group number */
 506         xfs_agblock_t           agbno,  /* allocation group block number */
 507         uint                    lock,   /* lock flags for read_buf */
 508         struct xfs_buf          **bpp,  /* buffer for agno/agbno */
 509         int                     refval);/* ref count value for buffer */
 510
 511 /*
 512  * Read-ahead the block, don't wait for it, don't return a buffer.
 513  * Long-form addressing.
 514  */
 515 void                                    /* error */
 516 xfs_btree_reada_bufl(
 517         struct xfs_mount        *mp,    /* file system mount point */
 518         xfs_fsblock_t           fsbno,  /* file system block number */
 519         xfs_extlen_t            count); /* count of filesystem blocks */
 520
 521 /*
 522  * Read-ahead the block, don't wait for it, don't return a buffer.
 523  * Short-form addressing.
 524  */
 525 void                                    /* error */
 526 xfs_btree_reada_bufs(
 527         struct xfs_mount        *mp,    /* file system mount point */
 528         xfs_agnumber_t          agno,   /* allocation group number */
 529         xfs_agblock_t           agbno,  /* allocation group block number */
 530         xfs_extlen_t            count); /* count of filesystem blocks */
 531
 532 /*
 533  * Read-ahead btree blocks, at the given level.
 534  * Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA.
 535  */
 536 int                                     /* readahead block count */
 537 xfs_btree_readahead(
 538         xfs_btree_cur_t         *cur,   /* btree cursor */
 539         int                     lev,    /* level in btree */
 540         int                     lr);    /* left/right bits */
 541
 542 /*
 543  * Set the buffer for level "lev" in the cursor to bp, releasing
 544  * any previous buffer.
 545  */
 546 void
 547 xfs_btree_setbuf(
 548         xfs_btree_cur_t         *cur,   /* btree cursor */
 549         int                     lev,    /* level in btree */
 550         struct xfs_buf          *bp);   /* new buffer to set */
 551
 552
 553 /*
 554  * Common btree core entry points.
 555  */
 556 int xfs_btree_increment(struct xfs_btree_cur *, int, int *);
 557 int xfs_btree_decrement(struct xfs_btree_cur *, int, int *);
 558 int xfs_btree_lookup(struct xfs_btree_cur *, xfs_lookup_t, int *);
 559 int xfs_btree_updkey(struct xfs_btree_cur *, union xfs_btree_key *, int);
 560 int xfs_btree_update(struct xfs_btree_cur *, union xfs_btree_rec *);
 561 int xfs_btree_lshift(struct xfs_btree_cur *, int, int *);
 562 int xfs_btree_rshift(struct xfs_btree_cur *, int, int *);
 563 int xfs_btree_split(struct xfs_btree_cur *, int, union xfs_btree_ptr *,
 564                 union xfs_btree_key *, struct xfs_btree_cur **, int *);
 565 int xfs_btree_new_root(struct xfs_btree_cur *, int *);
 566 int xfs_btree_new_iroot(struct xfs_btree_cur *, int *, int *);
 567 int xfs_btree_kill_iroot(struct xfs_btree_cur *);
 568 int xfs_btree_insert(struct xfs_btree_cur *, int *);
 569 int xfs_btree_delete(struct xfs_btree_cur *, int *);
 570 int xfs_btree_get_rec(struct xfs_btree_cur *, union xfs_btree_rec **, int *);
 571
 572 /*
 573  * Helpers.
 574  */
 575 static inline int xfs_btree_get_numrecs(struct xfs_btree_block *block)
 576 {
 577         return be16_to_cpu(block->bb_numrecs);
 578 }
 579
 580 static inline void xfs_btree_set_numrecs(struct xfs_btree_block *block,
 581                 __uint16_t numrecs)
 582 {
 583         block->bb_numrecs = cpu_to_be16(numrecs);
 584 }
 585
 586 static inline int xfs_btree_get_level(struct xfs_btree_block *block)
 587 {
 588         return be16_to_cpu(block->bb_level);
 589 }
 590
 591 #endif  /* __KERNEL__ */
 592
 593
 594 /*
 595  * Min and max functions for extlen, agblock, fileoff, and filblks types.
 596  */
 597 #define XFS_EXTLEN_MIN(a,b)     min_t(xfs_extlen_t, (a), (b))
 598 #define XFS_EXTLEN_MAX(a,b)     max_t(xfs_extlen_t, (a), (b))
 599 #define XFS_AGBLOCK_MIN(a,b)    min_t(xfs_agblock_t, (a), (b))
 600 #define XFS_AGBLOCK_MAX(a,b)    max_t(xfs_agblock_t, (a), (b))
 601 #define XFS_FILEOFF_MIN(a,b)    min_t(xfs_fileoff_t, (a), (b))
 602 #define XFS_FILEOFF_MAX(a,b)    max_t(xfs_fileoff_t, (a), (b))
 603 #define XFS_FILBLKS_MIN(a,b)    min_t(xfs_filblks_t, (a), (b))
 604 #define XFS_FILBLKS_MAX(a,b)    max_t(xfs_filblks_t, (a), (b))
 605
 606 #define XFS_FSB_SANITY_CHECK(mp,fsb)    \
 607         (XFS_FSB_TO_AGNO(mp, fsb) < mp->m_sb.sb_agcount && \
 608                 XFS_FSB_TO_AGBNO(mp, fsb) < mp->m_sb.sb_agblocks)
 609
 610 #endif  /* __XFS_BTREE_H__ */