fs/xfs/xfs_btree.h

   1 /*
   2  * Copyright (c) 2000-2001 Silicon Graphics, Inc.  All Rights Reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of version 2 of the GNU General Public License as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it would be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  11  *
  12  * Further, this software is distributed without any warranty that it is
  13  * free of the rightful claim of any third person regarding infringement
  14  * or the like.  Any license provided herein, whether implied or
  15  * otherwise, applies only to this software file.  Patent licenses, if
  16  * any, provided herein do not apply to combinations of this program with
  17  * other software, or any other product whatsoever.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write the Free Software Foundation, Inc., 59
  21  * Temple Place - Suite 330, Boston MA 02111-1307, USA.
  22  *
  23  * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
  24  * Mountain View, CA  94043, or:
  25  *
  26  * http://www.sgi.com
  27  *
  28  * For further information regarding this notice, see:
  29  *
  30  * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
  31  */
  32 #ifndef __XFS_BTREE_H__
  33 #define __XFS_BTREE_H__
  34
  35 struct xfs_buf;
  36 struct xfs_bmap_free;
  37 struct xfs_inode;
  38 struct xfs_mount;
  39 struct xfs_trans;
  40
  41 /*
  42  * This nonsense is to make -wlint happy.
  43  */
  44 #define XFS_LOOKUP_EQ   ((xfs_lookup_t)XFS_LOOKUP_EQi)
  45 #define XFS_LOOKUP_LE   ((xfs_lookup_t)XFS_LOOKUP_LEi)
  46 #define XFS_LOOKUP_GE   ((xfs_lookup_t)XFS_LOOKUP_GEi)
  47
  48 #define XFS_BTNUM_BNO   ((xfs_btnum_t)XFS_BTNUM_BNOi)
  49 #define XFS_BTNUM_CNT   ((xfs_btnum_t)XFS_BTNUM_CNTi)
  50 #define XFS_BTNUM_BMAP  ((xfs_btnum_t)XFS_BTNUM_BMAPi)
  51 #define XFS_BTNUM_INO   ((xfs_btnum_t)XFS_BTNUM_INOi)
  52
  53 /*
  54  * Short form header: space allocation btrees.
  55  */
  56 typedef struct xfs_btree_sblock
  57 {
  58         __uint32_t      bb_magic;       /* magic number for block type */
  59         __uint16_t      bb_level;       /* 0 is a leaf */
  60         __uint16_t      bb_numrecs;     /* current # of data records */
  61         xfs_agblock_t   bb_leftsib;     /* left sibling block or NULLAGBLOCK */
  62         xfs_agblock_t   bb_rightsib;    /* right sibling block or NULLAGBLOCK */
  63 } xfs_btree_sblock_t;
  64
  65 /*
  66  * Long form header: bmap btrees.
  67  */
  68 typedef struct xfs_btree_lblock
  69 {
  70         __uint32_t      bb_magic;       /* magic number for block type */
  71         __uint16_t      bb_level;       /* 0 is a leaf */
  72         __uint16_t      bb_numrecs;     /* current # of data records */
  73         xfs_dfsbno_t    bb_leftsib;     /* left sibling block or NULLDFSBNO */
  74         xfs_dfsbno_t    bb_rightsib;    /* right sibling block or NULLDFSBNO */
  75 } xfs_btree_lblock_t;
  76
  77 /*
  78  * Combined header and structure, used by common code.
  79  */
  80 typedef struct xfs_btree_hdr
  81 {
  82         __uint32_t      bb_magic;       /* magic number for block type */
  83         __uint16_t      bb_level;       /* 0 is a leaf */
  84         __uint16_t      bb_numrecs;     /* current # of data records */
  85 } xfs_btree_hdr_t;
  86
  87 typedef struct xfs_btree_block
  88 {
  89         xfs_btree_hdr_t bb_h;           /* header */
  90         union           {
  91                 struct  {
  92                         xfs_agblock_t   bb_leftsib;
  93                         xfs_agblock_t   bb_rightsib;
  94                 }       s;              /* short form pointers */
  95                 struct  {
  96                         xfs_dfsbno_t    bb_leftsib;
  97                         xfs_dfsbno_t    bb_rightsib;
  98                 }       l;              /* long form pointers */
  99         }               bb_u;           /* rest */
 100 } xfs_btree_block_t;
 101
 102 /*
 103  * For logging record fields.
 104  */
 105 #define XFS_BB_MAGIC            0x01
 106 #define XFS_BB_LEVEL            0x02
 107 #define XFS_BB_NUMRECS          0x04
 108 #define XFS_BB_LEFTSIB          0x08
 109 #define XFS_BB_RIGHTSIB         0x10
 110 #define XFS_BB_NUM_BITS         5
 111 #define XFS_BB_ALL_BITS         ((1 << XFS_BB_NUM_BITS) - 1)
 112
 113 /*
 114  * Boolean to select which form of xfs_btree_block_t.bb_u to use.
 115  */
 116 #define XFS_BTREE_LONG_PTRS(btnum)      ((btnum) == XFS_BTNUM_BMAP)
 117
 118 /*
 119  * Magic numbers for btree blocks.
 120  */
 121 extern const __uint32_t xfs_magics[];
 122
 123 /*
 124  * Maximum and minimum records in a btree block.
 125  * Given block size, type prefix, and leaf flag (0 or 1).
 126  * The divisor below is equivalent to lf ? (e1) : (e2) but that produces
 127  * compiler warnings.
 128  */
 129 #define XFS_BTREE_BLOCK_MAXRECS(bsz,t,lf)       \
 130         ((int)(((bsz) - (uint)sizeof(t ## _block_t)) / \
 131          (((lf) * (uint)sizeof(t ## _rec_t)) + \
 132           ((1 - (lf)) * \
 133            ((uint)sizeof(t ## _key_t) + (uint)sizeof(t ## _ptr_t))))))
 134 #define XFS_BTREE_BLOCK_MINRECS(bsz,t,lf)       \
 135         (XFS_BTREE_BLOCK_MAXRECS(bsz,t,lf) / 2)
 136
 137 /*
 138  * Record, key, and pointer address calculation macros.
 139  * Given block size, type prefix, block pointer, and index of requested entry
 140  * (first entry numbered 1).
 141  */
 142 #define XFS_BTREE_REC_ADDR(bsz,t,bb,i,mxr)      \
 143         ((t ## _rec_t *)((char *)(bb) + sizeof(t ## _block_t) + \
 144          ((i) - 1) * sizeof(t ## _rec_t)))
 145 #define XFS_BTREE_KEY_ADDR(bsz,t,bb,i,mxr)      \
 146         ((t ## _key_t *)((char *)(bb) + sizeof(t ## _block_t) + \
 147          ((i) - 1) * sizeof(t ## _key_t)))
 148 #define XFS_BTREE_PTR_ADDR(bsz,t,bb,i,mxr)      \
 149         ((t ## _ptr_t *)((char *)(bb) + sizeof(t ## _block_t) + \
 150          (mxr) * sizeof(t ## _key_t) + ((i) - 1) * sizeof(t ## _ptr_t)))
 151
 152 #define XFS_BTREE_MAXLEVELS     8       /* max of all btrees */
 153
 154 /*
 155  * Btree cursor structure.
 156  * This collects all information needed by the btree code in one place.
 157  */
 158 typedef struct xfs_btree_cur
 159 {
 160         struct xfs_trans        *bc_tp; /* transaction we're in, if any */
 161         struct xfs_mount        *bc_mp; /* file system mount struct */
 162         union {
 163                 xfs_alloc_rec_t         a;
 164                 xfs_bmbt_irec_t         b;
 165                 xfs_inobt_rec_t         i;
 166         }               bc_rec;         /* current insert/search record value */
 167         struct xfs_buf  *bc_bufs[XFS_BTREE_MAXLEVELS];  /* buf ptr per level */
 168         int             bc_ptrs[XFS_BTREE_MAXLEVELS];   /* key/record # */
 169         __uint8_t       bc_ra[XFS_BTREE_MAXLEVELS];     /* readahead bits */
 170 #define XFS_BTCUR_LEFTRA        1       /* left sibling has been read-ahead */
 171 #define XFS_BTCUR_RIGHTRA       2       /* right sibling has been read-ahead */
 172         __uint8_t       bc_nlevels;     /* number of levels in the tree */
 173         __uint8_t       bc_blocklog;    /* log2(blocksize) of btree blocks */
 174         xfs_btnum_t     bc_btnum;       /* identifies which btree type */
 175         union {
 176                 struct {                        /* needed for BNO, CNT */
 177                         struct xfs_buf  *agbp;  /* agf buffer pointer */
 178                         xfs_agnumber_t  agno;   /* ag number */
 179                 } a;
 180                 struct {                        /* needed for BMAP */
 181                         struct xfs_inode *ip;   /* pointer to our inode */
 182                         struct xfs_bmap_free *flist;    /* list to free after */
 183                         xfs_fsblock_t   firstblock;     /* 1st blk allocated */
 184                         int             allocated;      /* count of alloced */
 185                         short           forksize;       /* fork's inode space */
 186                         char            whichfork;      /* data or attr fork */
 187                         char            flags;          /* flags */
 188 #define XFS_BTCUR_BPRV_WASDEL   1                       /* was delayed */
 189                 } b;
 190                 struct {                        /* needed for INO */
 191                         struct xfs_buf  *agbp;  /* agi buffer pointer */
 192                         xfs_agnumber_t  agno;   /* ag number */
 193                 } i;
 194         }               bc_private;     /* per-btree type data */
 195 } xfs_btree_cur_t;
 196
 197 #define XFS_BTREE_NOERROR       0
 198 #define XFS_BTREE_ERROR         1
 199
 200 /*
 201  * Convert from buffer to btree block header.
 202  */
 203 #define XFS_BUF_TO_BLOCK(bp)    ((xfs_btree_block_t *)XFS_BUF_PTR(bp))
 204 #define XFS_BUF_TO_LBLOCK(bp)   ((xfs_btree_lblock_t *)XFS_BUF_PTR(bp))
 205 #define XFS_BUF_TO_SBLOCK(bp)   ((xfs_btree_sblock_t *)XFS_BUF_PTR(bp))
 206
 207
 208 #ifdef __KERNEL__
 209
 210 #ifdef DEBUG
 211 /*
 212  * Debug routine: check that block header is ok.
 213  */
 214 void
 215 xfs_btree_check_block(
 216         xfs_btree_cur_t         *cur,   /* btree cursor */
 217         xfs_btree_block_t       *block, /* generic btree block pointer */
 218         int                     level,  /* level of the btree block */
 219         struct xfs_buf          *bp);   /* buffer containing block, if any */
 220
 221 /*
 222  * Debug routine: check that keys are in the right order.
 223  */
 224 void
 225 xfs_btree_check_key(
 226         xfs_btnum_t             btnum,  /* btree identifier */
 227         void                    *ak1,   /* pointer to left (lower) key */
 228         void                    *ak2);  /* pointer to right (higher) key */
 229
 230 /*
 231  * Debug routine: check that records are in the right order.
 232  */
 233 void
 234 xfs_btree_check_rec(
 235         xfs_btnum_t             btnum,  /* btree identifier */
 236         void                    *ar1,   /* pointer to left (lower) record */
 237         void                    *ar2);  /* pointer to right (higher) record */
 238 #else
 239 #define xfs_btree_check_block(a,b,c,d)
 240 #define xfs_btree_check_key(a,b,c)
 241 #define xfs_btree_check_rec(a,b,c)
 242 #endif  /* DEBUG */
 243
 244 /*
 245  * Checking routine: check that long form block header is ok.
 246  */
 247 int                                     /* error (0 or EFSCORRUPTED) */
 248 xfs_btree_check_lblock(
 249         xfs_btree_cur_t         *cur,   /* btree cursor */
 250         xfs_btree_lblock_t      *block, /* btree long form block pointer */
 251         int                     level,  /* level of the btree block */
 252         struct xfs_buf          *bp);   /* buffer containing block, if any */
 253
 254 /*
 255  * Checking routine: check that (long) pointer is ok.
 256  */
 257 int                                     /* error (0 or EFSCORRUPTED) */
 258 xfs_btree_check_lptr(
 259         xfs_btree_cur_t         *cur,   /* btree cursor */
 260         xfs_dfsbno_t            ptr,    /* btree block disk address */
 261         int                     level); /* btree block level */
 262
 263 /*
 264  * Checking routine: check that short form block header is ok.
 265  */
 266 int                                     /* error (0 or EFSCORRUPTED) */
 267 xfs_btree_check_sblock(
 268         xfs_btree_cur_t         *cur,   /* btree cursor */
 269         xfs_btree_sblock_t      *block, /* btree short form block pointer */
 270         int                     level,  /* level of the btree block */
 271         struct xfs_buf          *bp);   /* buffer containing block */
 272
 273 /*
 274  * Checking routine: check that (short) pointer is ok.
 275  */
 276 int                                     /* error (0 or EFSCORRUPTED) */
 277 xfs_btree_check_sptr(
 278         xfs_btree_cur_t         *cur,   /* btree cursor */
 279         xfs_agblock_t           ptr,    /* btree block disk address */
 280         int                     level); /* btree block level */
 281
 282 /*
 283  * Delete the btree cursor.
 284  */
 285 void
 286 xfs_btree_del_cursor(
 287         xfs_btree_cur_t         *cur,   /* btree cursor */
 288         int                     error); /* del because of error */
 289
 290 /*
 291  * Duplicate the btree cursor.
 292  * Allocate a new one, copy the record, re-get the buffers.
 293  */
 294 int                                     /* error */
 295 xfs_btree_dup_cursor(
 296         xfs_btree_cur_t         *cur,   /* input cursor */
 297         xfs_btree_cur_t         **ncur);/* output cursor */
 298
 299 /*
 300  * Change the cursor to point to the first record in the current block
 301  * at the given level.  Other levels are unaffected.
 302  */
 303 int                                     /* success=1, failure=0 */
 304 xfs_btree_firstrec(
 305         xfs_btree_cur_t         *cur,   /* btree cursor */
 306         int                     level); /* level to change */
 307
 308 /*
 309  * Get a buffer for the block, return it with no data read.
 310  * Long-form addressing.
 311  */
 312 struct xfs_buf *                                /* buffer for fsbno */
 313 xfs_btree_get_bufl(
 314         struct xfs_mount        *mp,    /* file system mount point */
 315         struct xfs_trans        *tp,    /* transaction pointer */
 316         xfs_fsblock_t           fsbno,  /* file system block number */
 317         uint                    lock);  /* lock flags for get_buf */
 318
 319 /*
 320  * Get a buffer for the block, return it with no data read.
 321  * Short-form addressing.
 322  */
 323 struct xfs_buf *                                /* buffer for agno/agbno */
 324 xfs_btree_get_bufs(
 325         struct xfs_mount        *mp,    /* file system mount point */
 326         struct xfs_trans        *tp,    /* transaction pointer */
 327         xfs_agnumber_t          agno,   /* allocation group number */
 328         xfs_agblock_t           agbno,  /* allocation group block number */
 329         uint                    lock);  /* lock flags for get_buf */
 330
 331 /*
 332  * Allocate a new btree cursor.
 333  * The cursor is either for allocation (A) or bmap (B).
 334  */
 335 xfs_btree_cur_t *                       /* new btree cursor */
 336 xfs_btree_init_cursor(
 337         struct xfs_mount        *mp,    /* file system mount point */
 338         struct xfs_trans        *tp,    /* transaction pointer */
 339         struct xfs_buf          *agbp,  /* (A only) buffer for agf structure */
 340         xfs_agnumber_t          agno,   /* (A only) allocation group number */
 341         xfs_btnum_t             btnum,  /* btree identifier */
 342         struct xfs_inode        *ip,    /* (B only) inode owning the btree */
 343         int                     whichfork); /* (B only) data/attr fork */
 344
 345 /*
 346  * Check for the cursor referring to the last block at the given level.
 347  */
 348 int                                     /* 1=is last block, 0=not last block */
 349 xfs_btree_islastblock(
 350         xfs_btree_cur_t         *cur,   /* btree cursor */
 351         int                     level); /* level to check */
 352
 353 /*
 354  * Change the cursor to point to the last record in the current block
 355  * at the given level.  Other levels are unaffected.
 356  */
 357 int                                     /* success=1, failure=0 */
 358 xfs_btree_lastrec(
 359         xfs_btree_cur_t         *cur,   /* btree cursor */
 360         int                     level); /* level to change */
 361
 362 /*
 363  * Compute first and last byte offsets for the fields given.
 364  * Interprets the offsets table, which contains struct field offsets.
 365  */
 366 void
 367 xfs_btree_offsets(
 368         __int64_t               fields, /* bitmask of fields */
 369         const short             *offsets,/* table of field offsets */
 370         int                     nbits,  /* number of bits to inspect */
 371         int                     *first, /* output: first byte offset */
 372         int                     *last); /* output: last byte offset */
 373
 374 /*
 375  * Get a buffer for the block, return it read in.
 376  * Long-form addressing.
 377  */
 378 int                                     /* error */
 379 xfs_btree_read_bufl(
 380         struct xfs_mount        *mp,    /* file system mount point */
 381         struct xfs_trans        *tp,    /* transaction pointer */
 382         xfs_fsblock_t           fsbno,  /* file system block number */
 383         uint                    lock,   /* lock flags for read_buf */
 384         struct xfs_buf          **bpp,  /* buffer for fsbno */
 385         int                     refval);/* ref count value for buffer */
 386
 387 /*
 388  * Get a buffer for the block, return it read in.
 389  * Short-form addressing.
 390  */
 391 int                                     /* error */
 392 xfs_btree_read_bufs(
 393         struct xfs_mount        *mp,    /* file system mount point */
 394         struct xfs_trans        *tp,    /* transaction pointer */
 395         xfs_agnumber_t          agno,   /* allocation group number */
 396         xfs_agblock_t           agbno,  /* allocation group block number */
 397         uint                    lock,   /* lock flags for read_buf */
 398         struct xfs_buf          **bpp,  /* buffer for agno/agbno */
 399         int                     refval);/* ref count value for buffer */
 400
 401 /*
 402  * Read-ahead the block, don't wait for it, don't return a buffer.
 403  * Long-form addressing.
 404  */
 405 void                                    /* error */
 406 xfs_btree_reada_bufl(
 407         struct xfs_mount        *mp,    /* file system mount point */
 408         xfs_fsblock_t           fsbno,  /* file system block number */
 409         xfs_extlen_t            count); /* count of filesystem blocks */
 410
 411 /*
 412  * Read-ahead the block, don't wait for it, don't return a buffer.
 413  * Short-form addressing.
 414  */
 415 void                                    /* error */
 416 xfs_btree_reada_bufs(
 417         struct xfs_mount        *mp,    /* file system mount point */
 418         xfs_agnumber_t          agno,   /* allocation group number */
 419         xfs_agblock_t           agbno,  /* allocation group block number */
 420         xfs_extlen_t            count); /* count of filesystem blocks */
 421
 422 /*
 423  * Read-ahead btree blocks, at the given level.
 424  * Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA.
 425  */
 426 int                                     /* readahead block count */
 427 xfs_btree_readahead_core(
 428         xfs_btree_cur_t         *cur,   /* btree cursor */
 429         int                     lev,    /* level in btree */
 430         int                     lr);    /* left/right bits */
 431
 432 static inline int                       /* readahead block count */
 433 xfs_btree_readahead(
 434         xfs_btree_cur_t         *cur,   /* btree cursor */
 435         int                     lev,    /* level in btree */
 436         int                     lr)     /* left/right bits */
 437 {
 438         if ((cur->bc_ra[lev] | lr) == cur->bc_ra[lev])
 439                 return 0;
 440
 441         return xfs_btree_readahead_core(cur, lev, lr);
 442 }
 443
 444
 445 /*
 446  * Set the buffer for level "lev" in the cursor to bp, releasing
 447  * any previous buffer.
 448  */
 449 void
 450 xfs_btree_setbuf(
 451         xfs_btree_cur_t         *cur,   /* btree cursor */
 452         int                     lev,    /* level in btree */
 453         struct xfs_buf          *bp);   /* new buffer to set */
 454
 455 #endif  /* __KERNEL__ */
 456
 457
 458 /*
 459  * Min and max functions for extlen, agblock, fileoff, and filblks types.
 460  */
 461 #define XFS_EXTLEN_MIN(a,b)     \
 462         ((xfs_extlen_t)(a) < (xfs_extlen_t)(b) ? \
 463                 (xfs_extlen_t)(a) : (xfs_extlen_t)(b))
 464 #define XFS_EXTLEN_MAX(a,b)     \
 465         ((xfs_extlen_t)(a) > (xfs_extlen_t)(b) ? \
 466                 (xfs_extlen_t)(a) : (xfs_extlen_t)(b))
 467 #define XFS_AGBLOCK_MIN(a,b)    \
 468         ((xfs_agblock_t)(a) < (xfs_agblock_t)(b) ? \
 469                 (xfs_agblock_t)(a) : (xfs_agblock_t)(b))
 470 #define XFS_AGBLOCK_MAX(a,b)    \
 471         ((xfs_agblock_t)(a) > (xfs_agblock_t)(b) ? \
 472                 (xfs_agblock_t)(a) : (xfs_agblock_t)(b))
 473 #define XFS_FILEOFF_MIN(a,b)    \
 474         ((xfs_fileoff_t)(a) < (xfs_fileoff_t)(b) ? \
 475                 (xfs_fileoff_t)(a) : (xfs_fileoff_t)(b))
 476 #define XFS_FILEOFF_MAX(a,b)    \
 477         ((xfs_fileoff_t)(a) > (xfs_fileoff_t)(b) ? \
 478                 (xfs_fileoff_t)(a) : (xfs_fileoff_t)(b))
 479 #define XFS_FILBLKS_MIN(a,b)    \
 480         ((xfs_filblks_t)(a) < (xfs_filblks_t)(b) ? \
 481                 (xfs_filblks_t)(a) : (xfs_filblks_t)(b))
 482 #define XFS_FILBLKS_MAX(a,b)    \
 483         ((xfs_filblks_t)(a) > (xfs_filblks_t)(b) ? \
 484                 (xfs_filblks_t)(a) : (xfs_filblks_t)(b))
 485
 486 #define XFS_FSB_SANITY_CHECK(mp,fsb)    \
 487         (XFS_FSB_TO_AGNO(mp, fsb) < mp->m_sb.sb_agcount && \
 488                 XFS_FSB_TO_AGBNO(mp, fsb) < mp->m_sb.sb_agblocks)
 489
 490 #endif  /* __XFS_BTREE_H__ */