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  * Generic btree header.
  43  *
  44  * This is a combination of the actual format used on disk for short and long
  45  * format btrees.  The first three fields are shared by both format, but
  46  * the pointers are different and should be used with care.
  47  *
  48  * To get the size of the actual short or long form headers please use
  49  * the size macros below.  Never use sizeof(xfs_btree_block).
  50  */
  51 struct xfs_btree_block {
  52         __be32          bb_magic;       /* magic number for block type */
  53         __be16          bb_level;       /* 0 is a leaf */
  54         __be16          bb_numrecs;     /* current # of data records */
  55         union {
  56                 struct {
  57                         __be32          bb_leftsib;
  58                         __be32          bb_rightsib;
  59                 } s;                    /* short form pointers */
  60                 struct  {
  61                         __be64          bb_leftsib;
  62                         __be64          bb_rightsib;
  63                 } l;                    /* long form pointers */
  64         } bb_u;                         /* rest */
  65 };
  66
  67 #define XFS_BTREE_SBLOCK_LEN    16      /* size of a short form block */
  68 #define XFS_BTREE_LBLOCK_LEN    24      /* size of a long form block */
  69
  70
  71 /*
  72  * Generic key, ptr and record wrapper structures.
  73  *
  74  * These are disk format structures, and are converted where necessary
  75  * by the btree specific code that needs to interpret them.
  76  */
  77 union xfs_btree_ptr {
  78         __be32                  s;      /* short form ptr */
  79         __be64                  l;      /* long form ptr */
  80 };
  81
  82 union xfs_btree_key {
  83         xfs_bmbt_key_t          bmbt;
  84         xfs_bmdr_key_t          bmbr;   /* bmbt root block */
  85         xfs_alloc_key_t         alloc;
  86         xfs_inobt_key_t         inobt;
  87 };
  88
  89 union xfs_btree_rec {
  90         xfs_bmbt_rec_t          bmbt;
  91         xfs_bmdr_rec_t          bmbr;   /* bmbt root block */
  92         xfs_alloc_rec_t         alloc;
  93         xfs_inobt_rec_t         inobt;
  94 };
  95
  96 /*
  97  * For logging record fields.
  98  */
  99 #define XFS_BB_MAGIC            0x01
 100 #define XFS_BB_LEVEL            0x02
 101 #define XFS_BB_NUMRECS          0x04
 102 #define XFS_BB_LEFTSIB          0x08
 103 #define XFS_BB_RIGHTSIB         0x10
 104 #define XFS_BB_NUM_BITS         5
 105 #define XFS_BB_ALL_BITS         ((1 << XFS_BB_NUM_BITS) - 1)
 106
 107 /*
 108  * Magic numbers for btree blocks.
 109  */
 110 extern const __uint32_t xfs_magics[];
 111
 112 /*
 113  * Generic stats interface
 114  */
 115 #define __XFS_BTREE_STATS_INC(type, stat) \
 116         XFS_STATS_INC(xs_ ## type ## _2_ ## stat)
 117 #define XFS_BTREE_STATS_INC(cur, stat)  \
 118 do {    \
 119         switch (cur->bc_btnum) {  \
 120         case XFS_BTNUM_BNO: __XFS_BTREE_STATS_INC(abtb, stat); break;   \
 121         case XFS_BTNUM_CNT: __XFS_BTREE_STATS_INC(abtc, stat); break;   \
 122         case XFS_BTNUM_BMAP: __XFS_BTREE_STATS_INC(bmbt, stat); break;  \
 123         case XFS_BTNUM_INO: __XFS_BTREE_STATS_INC(ibt, stat); break;    \
 124         case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break;       \
 125         }       \
 126 } while (0)
 127
 128 #define __XFS_BTREE_STATS_ADD(type, stat, val) \
 129         XFS_STATS_ADD(xs_ ## type ## _2_ ## stat, val)
 130 #define XFS_BTREE_STATS_ADD(cur, stat, val)  \
 131 do {    \
 132         switch (cur->bc_btnum) {  \
 133         case XFS_BTNUM_BNO: __XFS_BTREE_STATS_ADD(abtb, stat, val); break; \
 134         case XFS_BTNUM_CNT: __XFS_BTREE_STATS_ADD(abtc, stat, val); break; \
 135         case XFS_BTNUM_BMAP: __XFS_BTREE_STATS_ADD(bmbt, stat, val); break; \
 136         case XFS_BTNUM_INO: __XFS_BTREE_STATS_ADD(ibt, stat, val); break; \
 137         case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break;       \
 138         }       \
 139 } while (0)
 140
 141 #define XFS_BTREE_MAXLEVELS     8       /* max of all btrees */
 142
 143 struct xfs_btree_ops {
 144         /* size of the key and record structures */
 145         size_t  key_len;
 146         size_t  rec_len;
 147
 148         /* cursor operations */
 149         struct xfs_btree_cur *(*dup_cursor)(struct xfs_btree_cur *);
 150         void    (*update_cursor)(struct xfs_btree_cur *src,
 151                                  struct xfs_btree_cur *dst);
 152
 153         /* update btree root pointer */
 154         void    (*set_root)(struct xfs_btree_cur *cur,
 155                             union xfs_btree_ptr *nptr, int level_change);
 156
 157         /* block allocation / freeing */
 158         int     (*alloc_block)(struct xfs_btree_cur *cur,
 159                                union xfs_btree_ptr *start_bno,
 160                                union xfs_btree_ptr *new_bno,
 161                                int length, int *stat);
 162         int     (*free_block)(struct xfs_btree_cur *cur, struct xfs_buf *bp);
 163
 164         /* update last record information */
 165         void    (*update_lastrec)(struct xfs_btree_cur *cur,
 166                                   struct xfs_btree_block *block,
 167                                   union xfs_btree_rec *rec,
 168                                   int ptr, int reason);
 169
 170         /* records in block/level */
 171         int     (*get_minrecs)(struct xfs_btree_cur *cur, int level);
 172         int     (*get_maxrecs)(struct xfs_btree_cur *cur, int level);
 173
 174         /* records on disk.  Matter for the root in inode case. */
 175         int     (*get_dmaxrecs)(struct xfs_btree_cur *cur, int level);
 176
 177         /* init values of btree structures */
 178         void    (*init_key_from_rec)(union xfs_btree_key *key,
 179                                      union xfs_btree_rec *rec);
 180         void    (*init_rec_from_key)(union xfs_btree_key *key,
 181                                      union xfs_btree_rec *rec);
 182         void    (*init_rec_from_cur)(struct xfs_btree_cur *cur,
 183                                      union xfs_btree_rec *rec);
 184         void    (*init_ptr_from_cur)(struct xfs_btree_cur *cur,
 185                                      union xfs_btree_ptr *ptr);
 186
 187         /* difference between key value and cursor value */
 188         __int64_t (*key_diff)(struct xfs_btree_cur *cur,
 189                               union xfs_btree_key *key);
 190
 191         void    (*read_verify)(struct xfs_buf *bp);
 192         void    (*write_verify)(struct xfs_buf *bp);
 193
 194 #ifdef DEBUG
 195         /* check that k1 is lower than k2 */
 196         int     (*keys_inorder)(struct xfs_btree_cur *cur,
 197                                 union xfs_btree_key *k1,
 198                                 union xfs_btree_key *k2);
 199
 200         /* check that r1 is lower than r2 */
 201         int     (*recs_inorder)(struct xfs_btree_cur *cur,
 202                                 union xfs_btree_rec *r1,
 203                                 union xfs_btree_rec *r2);
 204 #endif
 205 };
 206
 207 /*
 208  * Reasons for the update_lastrec method to be called.
 209  */
 210 #define LASTREC_UPDATE  0
 211 #define LASTREC_INSREC  1
 212 #define LASTREC_DELREC  2
 213
 214
 215 /*
 216  * Btree cursor structure.
 217  * This collects all information needed by the btree code in one place.
 218  */
 219 typedef struct xfs_btree_cur
 220 {
 221         struct xfs_trans        *bc_tp; /* transaction we're in, if any */
 222         struct xfs_mount        *bc_mp; /* file system mount struct */
 223         const struct xfs_btree_ops *bc_ops;
 224         uint                    bc_flags; /* btree features - below */
 225         union {
 226                 xfs_alloc_rec_incore_t  a;
 227                 xfs_bmbt_irec_t         b;
 228                 xfs_inobt_rec_incore_t  i;
 229         }               bc_rec;         /* current insert/search record value */
 230         struct xfs_buf  *bc_bufs[XFS_BTREE_MAXLEVELS];  /* buf ptr per level */
 231         int             bc_ptrs[XFS_BTREE_MAXLEVELS];   /* key/record # */
 232         __uint8_t       bc_ra[XFS_BTREE_MAXLEVELS];     /* readahead bits */
 233 #define XFS_BTCUR_LEFTRA        1       /* left sibling has been read-ahead */
 234 #define XFS_BTCUR_RIGHTRA       2       /* right sibling has been read-ahead */
 235         __uint8_t       bc_nlevels;     /* number of levels in the tree */
 236         __uint8_t       bc_blocklog;    /* log2(blocksize) of btree blocks */
 237         xfs_btnum_t     bc_btnum;       /* identifies which btree type */
 238         union {
 239                 struct {                        /* needed for BNO, CNT, INO */
 240                         struct xfs_buf  *agbp;  /* agf/agi buffer pointer */
 241                         xfs_agnumber_t  agno;   /* ag number */
 242                 } a;
 243                 struct {                        /* needed for BMAP */
 244                         struct xfs_inode *ip;   /* pointer to our inode */
 245                         struct xfs_bmap_free *flist;    /* list to free after */
 246                         xfs_fsblock_t   firstblock;     /* 1st blk allocated */
 247                         int             allocated;      /* count of alloced */
 248                         short           forksize;       /* fork's inode space */
 249                         char            whichfork;      /* data or attr fork */
 250                         char            flags;          /* flags */
 251 #define XFS_BTCUR_BPRV_WASDEL   1                       /* was delayed */
 252                 } b;
 253         }               bc_private;     /* per-btree type data */
 254 } xfs_btree_cur_t;
 255
 256 /* cursor flags */
 257 #define XFS_BTREE_LONG_PTRS             (1<<0)  /* pointers are 64bits long */
 258 #define XFS_BTREE_ROOT_IN_INODE         (1<<1)  /* root may be variable size */
 259 #define XFS_BTREE_LASTREC_UPDATE        (1<<2)  /* track last rec externally */
 260
 261
 262 #define XFS_BTREE_NOERROR       0
 263 #define XFS_BTREE_ERROR         1
 264
 265 /*
 266  * Convert from buffer to btree block header.
 267  */
 268 #define XFS_BUF_TO_BLOCK(bp)    ((struct xfs_btree_block *)((bp)->b_addr))
 269
 270
 271 /*
 272  * Check that block header is ok.
 273  */
 274 int
 275 xfs_btree_check_block(
 276         struct xfs_btree_cur    *cur,   /* btree cursor */
 277         struct xfs_btree_block  *block, /* generic btree block pointer */
 278         int                     level,  /* level of the btree block */
 279         struct xfs_buf          *bp);   /* buffer containing block, if any */
 280
 281 /*
 282  * Check that (long) pointer is ok.
 283  */
 284 int                                     /* error (0 or EFSCORRUPTED) */
 285 xfs_btree_check_lptr(
 286         struct xfs_btree_cur    *cur,   /* btree cursor */
 287         xfs_dfsbno_t            ptr,    /* btree block disk address */
 288         int                     level); /* btree block level */
 289
 290 /*
 291  * Delete the btree cursor.
 292  */
 293 void
 294 xfs_btree_del_cursor(
 295         xfs_btree_cur_t         *cur,   /* btree cursor */
 296         int                     error); /* del because of error */
 297
 298 /*
 299  * Duplicate the btree cursor.
 300  * Allocate a new one, copy the record, re-get the buffers.
 301  */
 302 int                                     /* error */
 303 xfs_btree_dup_cursor(
 304         xfs_btree_cur_t         *cur,   /* input cursor */
 305         xfs_btree_cur_t         **ncur);/* output cursor */
 306
 307 /*
 308  * Get a buffer for the block, return it with no data read.
 309  * Long-form addressing.
 310  */
 311 struct xfs_buf *                                /* buffer for fsbno */
 312 xfs_btree_get_bufl(
 313         struct xfs_mount        *mp,    /* file system mount point */
 314         struct xfs_trans        *tp,    /* transaction pointer */
 315         xfs_fsblock_t           fsbno,  /* file system block number */
 316         uint                    lock);  /* lock flags for get_buf */
 317
 318 /*
 319  * Get a buffer for the block, return it with no data read.
 320  * Short-form addressing.
 321  */
 322 struct xfs_buf *                                /* buffer for agno/agbno */
 323 xfs_btree_get_bufs(
 324         struct xfs_mount        *mp,    /* file system mount point */
 325         struct xfs_trans        *tp,    /* transaction pointer */
 326         xfs_agnumber_t          agno,   /* allocation group number */
 327         xfs_agblock_t           agbno,  /* allocation group block number */
 328         uint                    lock);  /* lock flags for get_buf */
 329
 330 /*
 331  * Check for the cursor referring to the last block at the given level.
 332  */
 333 int                                     /* 1=is last block, 0=not last block */
 334 xfs_btree_islastblock(
 335         xfs_btree_cur_t         *cur,   /* btree cursor */
 336         int                     level); /* level to check */
 337
 338 /*
 339  * Compute first and last byte offsets for the fields given.
 340  * Interprets the offsets table, which contains struct field offsets.
 341  */
 342 void
 343 xfs_btree_offsets(
 344         __int64_t               fields, /* bitmask of fields */
 345         const short             *offsets,/* table of field offsets */
 346         int                     nbits,  /* number of bits to inspect */
 347         int                     *first, /* output: first byte offset */
 348         int                     *last); /* output: last byte offset */
 349
 350 /*
 351  * Get a buffer for the block, return it read in.
 352  * Long-form addressing.
 353  */
 354 int                                     /* error */
 355 xfs_btree_read_bufl(
 356         struct xfs_mount        *mp,    /* file system mount point */
 357         struct xfs_trans        *tp,    /* transaction pointer */
 358         xfs_fsblock_t           fsbno,  /* file system block number */
 359         uint                    lock,   /* lock flags for read_buf */
 360         struct xfs_buf          **bpp,  /* buffer for fsbno */
 361         int                     refval, /* ref count value for buffer */
 362         xfs_buf_iodone_t        verify);
 363
 364 /*
 365  * Read-ahead the block, don't wait for it, don't return a buffer.
 366  * Long-form addressing.
 367  */
 368 void                                    /* error */
 369 xfs_btree_reada_bufl(
 370         struct xfs_mount        *mp,    /* file system mount point */
 371         xfs_fsblock_t           fsbno,  /* file system block number */
 372         xfs_extlen_t            count,  /* count of filesystem blocks */
 373         xfs_buf_iodone_t        verify);
 374
 375 /*
 376  * Read-ahead the block, don't wait for it, don't return a buffer.
 377  * Short-form addressing.
 378  */
 379 void                                    /* error */
 380 xfs_btree_reada_bufs(
 381         struct xfs_mount        *mp,    /* file system mount point */
 382         xfs_agnumber_t          agno,   /* allocation group number */
 383         xfs_agblock_t           agbno,  /* allocation group block number */
 384         xfs_extlen_t            count,  /* count of filesystem blocks */
 385         xfs_buf_iodone_t        verify);
 386
 387 /*
 388  * Initialise a new btree block header
 389  */
 390 void
 391 xfs_btree_init_block(
 392         struct xfs_mount *mp,
 393         struct xfs_buf  *bp,
 394         __u32           magic,
 395         __u16           level,
 396         __u16           numrecs,
 397         unsigned int    flags);
 398
 399 /*
 400  * Common btree core entry points.
 401  */
 402 int xfs_btree_increment(struct xfs_btree_cur *, int, int *);
 403 int xfs_btree_decrement(struct xfs_btree_cur *, int, int *);
 404 int xfs_btree_lookup(struct xfs_btree_cur *, xfs_lookup_t, int *);
 405 int xfs_btree_update(struct xfs_btree_cur *, union xfs_btree_rec *);
 406 int xfs_btree_new_iroot(struct xfs_btree_cur *, int *, int *);
 407 int xfs_btree_insert(struct xfs_btree_cur *, int *);
 408 int xfs_btree_delete(struct xfs_btree_cur *, int *);
 409 int xfs_btree_get_rec(struct xfs_btree_cur *, union xfs_btree_rec **, int *);
 410
 411 /*
 412  * Internal btree helpers also used by xfs_bmap.c.
 413  */
 414 void xfs_btree_log_block(struct xfs_btree_cur *, struct xfs_buf *, int);
 415 void xfs_btree_log_recs(struct xfs_btree_cur *, struct xfs_buf *, int, int);
 416
 417 /*
 418  * Helpers.
 419  */
 420 static inline int xfs_btree_get_numrecs(struct xfs_btree_block *block)
 421 {
 422         return be16_to_cpu(block->bb_numrecs);
 423 }
 424
 425 static inline void xfs_btree_set_numrecs(struct xfs_btree_block *block,
 426                 __uint16_t numrecs)
 427 {
 428         block->bb_numrecs = cpu_to_be16(numrecs);
 429 }
 430
 431 static inline int xfs_btree_get_level(struct xfs_btree_block *block)
 432 {
 433         return be16_to_cpu(block->bb_level);
 434 }
 435
 436
 437 /*
 438  * Min and max functions for extlen, agblock, fileoff, and filblks types.
 439  */
 440 #define XFS_EXTLEN_MIN(a,b)     min_t(xfs_extlen_t, (a), (b))
 441 #define XFS_EXTLEN_MAX(a,b)     max_t(xfs_extlen_t, (a), (b))
 442 #define XFS_AGBLOCK_MIN(a,b)    min_t(xfs_agblock_t, (a), (b))
 443 #define XFS_AGBLOCK_MAX(a,b)    max_t(xfs_agblock_t, (a), (b))
 444 #define XFS_FILEOFF_MIN(a,b)    min_t(xfs_fileoff_t, (a), (b))
 445 #define XFS_FILEOFF_MAX(a,b)    max_t(xfs_fileoff_t, (a), (b))
 446 #define XFS_FILBLKS_MIN(a,b)    min_t(xfs_filblks_t, (a), (b))
 447 #define XFS_FILBLKS_MAX(a,b)    max_t(xfs_filblks_t, (a), (b))
 448
 449 #define XFS_FSB_SANITY_CHECK(mp,fsb)    \
 450         (XFS_FSB_TO_AGNO(mp, fsb) < mp->m_sb.sb_agcount && \
 451                 XFS_FSB_TO_AGBNO(mp, fsb) < mp->m_sb.sb_agblocks)
 452
 453 /*
 454  * Trace hooks.  Currently not implemented as they need to be ported
 455  * over to the generic tracing functionality, which is some effort.
 456  *
 457  * i,j = integer (32 bit)
 458  * b = btree block buffer (xfs_buf_t)
 459  * p = btree ptr
 460  * r = btree record
 461  * k = btree key
 462  */
 463 #define XFS_BTREE_TRACE_ARGBI(c, b, i)
 464 #define XFS_BTREE_TRACE_ARGBII(c, b, i, j)
 465 #define XFS_BTREE_TRACE_ARGI(c, i)
 466 #define XFS_BTREE_TRACE_ARGIPK(c, i, p, s)
 467 #define XFS_BTREE_TRACE_ARGIPR(c, i, p, r)
 468 #define XFS_BTREE_TRACE_ARGIK(c, i, k)
 469 #define XFS_BTREE_TRACE_ARGR(c, r)
 470 #define XFS_BTREE_TRACE_CURSOR(c, t)
 471
 472 #endif  /* __XFS_BTREE_H__ */