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  * Generic key, ptr and record wrapper structures.
  31  *
  32  * These are disk format structures, and are converted where necessary
  33  * by the btree specific code that needs to interpret them.
  34  */
  35 union xfs_btree_ptr {
  36         __be32                  s;      /* short form ptr */
  37         __be64                  l;      /* long form ptr */
  38 };
  39
  40 union xfs_btree_key {
  41         xfs_bmbt_key_t          bmbt;
  42         xfs_bmdr_key_t          bmbr;   /* bmbt root block */
  43         xfs_alloc_key_t         alloc;
  44         xfs_inobt_key_t         inobt;
  45 };
  46
  47 union xfs_btree_rec {
  48         xfs_bmbt_rec_t          bmbt;
  49         xfs_bmdr_rec_t          bmbr;   /* bmbt root block */
  50         xfs_alloc_rec_t         alloc;
  51         xfs_inobt_rec_t         inobt;
  52 };
  53
  54 /*
  55  * This nonsense is to make -wlint happy.
  56  */
  57 #define XFS_LOOKUP_EQ   ((xfs_lookup_t)XFS_LOOKUP_EQi)
  58 #define XFS_LOOKUP_LE   ((xfs_lookup_t)XFS_LOOKUP_LEi)
  59 #define XFS_LOOKUP_GE   ((xfs_lookup_t)XFS_LOOKUP_GEi)
  60
  61 #define XFS_BTNUM_BNO   ((xfs_btnum_t)XFS_BTNUM_BNOi)
  62 #define XFS_BTNUM_CNT   ((xfs_btnum_t)XFS_BTNUM_CNTi)
  63 #define XFS_BTNUM_BMAP  ((xfs_btnum_t)XFS_BTNUM_BMAPi)
  64 #define XFS_BTNUM_INO   ((xfs_btnum_t)XFS_BTNUM_INOi)
  65
  66 /*
  67  * For logging record fields.
  68  */
  69 #define XFS_BB_MAGIC            (1 << 0)
  70 #define XFS_BB_LEVEL            (1 << 1)
  71 #define XFS_BB_NUMRECS          (1 << 2)
  72 #define XFS_BB_LEFTSIB          (1 << 3)
  73 #define XFS_BB_RIGHTSIB         (1 << 4)
  74 #define XFS_BB_BLKNO            (1 << 5)
  75 #define XFS_BB_LSN              (1 << 6)
  76 #define XFS_BB_UUID             (1 << 7)
  77 #define XFS_BB_OWNER            (1 << 8)
  78 #define XFS_BB_NUM_BITS         5
  79 #define XFS_BB_ALL_BITS         ((1 << XFS_BB_NUM_BITS) - 1)
  80 #define XFS_BB_NUM_BITS_CRC     9
  81 #define XFS_BB_ALL_BITS_CRC     ((1 << XFS_BB_NUM_BITS_CRC) - 1)
  82
  83 /*
  84  * Generic stats interface
  85  */
  86 #define __XFS_BTREE_STATS_INC(type, stat) \
  87         XFS_STATS_INC(xs_ ## type ## _2_ ## stat)
  88 #define XFS_BTREE_STATS_INC(cur, stat)  \
  89 do {    \
  90         switch (cur->bc_btnum) {  \
  91         case XFS_BTNUM_BNO: __XFS_BTREE_STATS_INC(abtb, stat); break;   \
  92         case XFS_BTNUM_CNT: __XFS_BTREE_STATS_INC(abtc, stat); break;   \
  93         case XFS_BTNUM_BMAP: __XFS_BTREE_STATS_INC(bmbt, stat); break;  \
  94         case XFS_BTNUM_INO: __XFS_BTREE_STATS_INC(ibt, stat); break;    \
  95         case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break;       \
  96         }       \
  97 } while (0)
  98
  99 #define __XFS_BTREE_STATS_ADD(type, stat, val) \
 100         XFS_STATS_ADD(xs_ ## type ## _2_ ## stat, val)
 101 #define XFS_BTREE_STATS_ADD(cur, stat, val)  \
 102 do {    \
 103         switch (cur->bc_btnum) {  \
 104         case XFS_BTNUM_BNO: __XFS_BTREE_STATS_ADD(abtb, stat, val); break; \
 105         case XFS_BTNUM_CNT: __XFS_BTREE_STATS_ADD(abtc, stat, val); break; \
 106         case XFS_BTNUM_BMAP: __XFS_BTREE_STATS_ADD(bmbt, stat, val); break; \
 107         case XFS_BTNUM_INO: __XFS_BTREE_STATS_ADD(ibt, stat, val); break; \
 108         case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break;       \
 109         }       \
 110 } while (0)
 111
 112 #define XFS_BTREE_MAXLEVELS     8       /* max of all btrees */
 113
 114 struct xfs_btree_ops {
 115         /* size of the key and record structures */
 116         size_t  key_len;
 117         size_t  rec_len;
 118
 119         /* cursor operations */
 120         struct xfs_btree_cur *(*dup_cursor)(struct xfs_btree_cur *);
 121         void    (*update_cursor)(struct xfs_btree_cur *src,
 122                                  struct xfs_btree_cur *dst);
 123
 124         /* update btree root pointer */
 125         void    (*set_root)(struct xfs_btree_cur *cur,
 126                             union xfs_btree_ptr *nptr, int level_change);
 127
 128         /* block allocation / freeing */
 129         int     (*alloc_block)(struct xfs_btree_cur *cur,
 130                                union xfs_btree_ptr *start_bno,
 131                                union xfs_btree_ptr *new_bno,
 132                                int length, int *stat);
 133         int     (*free_block)(struct xfs_btree_cur *cur, struct xfs_buf *bp);
 134
 135         /* update last record information */
 136         void    (*update_lastrec)(struct xfs_btree_cur *cur,
 137                                   struct xfs_btree_block *block,
 138                                   union xfs_btree_rec *rec,
 139                                   int ptr, int reason);
 140
 141         /* records in block/level */
 142         int     (*get_minrecs)(struct xfs_btree_cur *cur, int level);
 143         int     (*get_maxrecs)(struct xfs_btree_cur *cur, int level);
 144
 145         /* records on disk.  Matter for the root in inode case. */
 146         int     (*get_dmaxrecs)(struct xfs_btree_cur *cur, int level);
 147
 148         /* init values of btree structures */
 149         void    (*init_key_from_rec)(union xfs_btree_key *key,
 150                                      union xfs_btree_rec *rec);
 151         void    (*init_rec_from_key)(union xfs_btree_key *key,
 152                                      union xfs_btree_rec *rec);
 153         void    (*init_rec_from_cur)(struct xfs_btree_cur *cur,
 154                                      union xfs_btree_rec *rec);
 155         void    (*init_ptr_from_cur)(struct xfs_btree_cur *cur,
 156                                      union xfs_btree_ptr *ptr);
 157
 158         /* difference between key value and cursor value */
 159         __int64_t (*key_diff)(struct xfs_btree_cur *cur,
 160                               union xfs_btree_key *key);
 161
 162         const struct xfs_buf_ops        *buf_ops;
 163
 164 #if defined(DEBUG) || defined(XFS_WARN)
 165         /* check that k1 is lower than k2 */
 166         int     (*keys_inorder)(struct xfs_btree_cur *cur,
 167                                 union xfs_btree_key *k1,
 168                                 union xfs_btree_key *k2);
 169
 170         /* check that r1 is lower than r2 */
 171         int     (*recs_inorder)(struct xfs_btree_cur *cur,
 172                                 union xfs_btree_rec *r1,
 173                                 union xfs_btree_rec *r2);
 174 #endif
 175 };
 176
 177 /*
 178  * Reasons for the update_lastrec method to be called.
 179  */
 180 #define LASTREC_UPDATE  0
 181 #define LASTREC_INSREC  1
 182 #define LASTREC_DELREC  2
 183
 184
 185 /*
 186  * Btree cursor structure.
 187  * This collects all information needed by the btree code in one place.
 188  */
 189 typedef struct xfs_btree_cur
 190 {
 191         struct xfs_trans        *bc_tp; /* transaction we're in, if any */
 192         struct xfs_mount        *bc_mp; /* file system mount struct */
 193         const struct xfs_btree_ops *bc_ops;
 194         uint                    bc_flags; /* btree features - below */
 195         union {
 196                 xfs_alloc_rec_incore_t  a;
 197                 xfs_bmbt_irec_t         b;
 198                 xfs_inobt_rec_incore_t  i;
 199         }               bc_rec;         /* current insert/search record value */
 200         struct xfs_buf  *bc_bufs[XFS_BTREE_MAXLEVELS];  /* buf ptr per level */
 201         int             bc_ptrs[XFS_BTREE_MAXLEVELS];   /* key/record # */
 202         __uint8_t       bc_ra[XFS_BTREE_MAXLEVELS];     /* readahead bits */
 203 #define XFS_BTCUR_LEFTRA        1       /* left sibling has been read-ahead */
 204 #define XFS_BTCUR_RIGHTRA       2       /* right sibling has been read-ahead */
 205         __uint8_t       bc_nlevels;     /* number of levels in the tree */
 206         __uint8_t       bc_blocklog;    /* log2(blocksize) of btree blocks */
 207         xfs_btnum_t     bc_btnum;       /* identifies which btree type */
 208         union {
 209                 struct {                        /* needed for BNO, CNT, INO */
 210                         struct xfs_buf  *agbp;  /* agf/agi buffer pointer */
 211                         xfs_agnumber_t  agno;   /* ag number */
 212                 } a;
 213                 struct {                        /* needed for BMAP */
 214                         struct xfs_inode *ip;   /* pointer to our inode */
 215                         struct xfs_bmap_free *flist;    /* list to free after */
 216                         xfs_fsblock_t   firstblock;     /* 1st blk allocated */
 217                         int             allocated;      /* count of alloced */
 218                         short           forksize;       /* fork's inode space */
 219                         char            whichfork;      /* data or attr fork */
 220                         char            flags;          /* flags */
 221 #define XFS_BTCUR_BPRV_WASDEL   1                       /* was delayed */
 222                 } b;
 223         }               bc_private;     /* per-btree type data */
 224 } xfs_btree_cur_t;
 225
 226 /* cursor flags */
 227 #define XFS_BTREE_LONG_PTRS             (1<<0)  /* pointers are 64bits long */
 228 #define XFS_BTREE_ROOT_IN_INODE         (1<<1)  /* root may be variable size */
 229 #define XFS_BTREE_LASTREC_UPDATE        (1<<2)  /* track last rec externally */
 230 #define XFS_BTREE_CRC_BLOCKS            (1<<3)  /* uses extended btree blocks */
 231
 232
 233 #define XFS_BTREE_NOERROR       0
 234 #define XFS_BTREE_ERROR         1
 235
 236 /*
 237  * Convert from buffer to btree block header.
 238  */
 239 #define XFS_BUF_TO_BLOCK(bp)    ((struct xfs_btree_block *)((bp)->b_addr))
 240
 241
 242 /*
 243  * Check that block header is ok.
 244  */
 245 int
 246 xfs_btree_check_block(
 247         struct xfs_btree_cur    *cur,   /* btree cursor */
 248         struct xfs_btree_block  *block, /* generic btree block pointer */
 249         int                     level,  /* level of the btree block */
 250         struct xfs_buf          *bp);   /* buffer containing block, if any */
 251
 252 /*
 253  * Check that (long) pointer is ok.
 254  */
 255 int                                     /* error (0 or EFSCORRUPTED) */
 256 xfs_btree_check_lptr(
 257         struct xfs_btree_cur    *cur,   /* btree cursor */
 258         xfs_dfsbno_t            ptr,    /* btree block disk address */
 259         int                     level); /* btree block level */
 260
 261 /*
 262  * Delete the btree cursor.
 263  */
 264 void
 265 xfs_btree_del_cursor(
 266         xfs_btree_cur_t         *cur,   /* btree cursor */
 267         int                     error); /* del because of error */
 268
 269 /*
 270  * Duplicate the btree cursor.
 271  * Allocate a new one, copy the record, re-get the buffers.
 272  */
 273 int                                     /* error */
 274 xfs_btree_dup_cursor(
 275         xfs_btree_cur_t         *cur,   /* input cursor */
 276         xfs_btree_cur_t         **ncur);/* output cursor */
 277
 278 /*
 279  * Get a buffer for the block, return it with no data read.
 280  * Long-form addressing.
 281  */
 282 struct xfs_buf *                                /* buffer for fsbno */
 283 xfs_btree_get_bufl(
 284         struct xfs_mount        *mp,    /* file system mount point */
 285         struct xfs_trans        *tp,    /* transaction pointer */
 286         xfs_fsblock_t           fsbno,  /* file system block number */
 287         uint                    lock);  /* lock flags for get_buf */
 288
 289 /*
 290  * Get a buffer for the block, return it with no data read.
 291  * Short-form addressing.
 292  */
 293 struct xfs_buf *                                /* buffer for agno/agbno */
 294 xfs_btree_get_bufs(
 295         struct xfs_mount        *mp,    /* file system mount point */
 296         struct xfs_trans        *tp,    /* transaction pointer */
 297         xfs_agnumber_t          agno,   /* allocation group number */
 298         xfs_agblock_t           agbno,  /* allocation group block number */
 299         uint                    lock);  /* lock flags for get_buf */
 300
 301 /*
 302  * Check for the cursor referring to the last block at the given level.
 303  */
 304 int                                     /* 1=is last block, 0=not last block */
 305 xfs_btree_islastblock(
 306         xfs_btree_cur_t         *cur,   /* btree cursor */
 307         int                     level); /* level to check */
 308
 309 /*
 310  * Compute first and last byte offsets for the fields given.
 311  * Interprets the offsets table, which contains struct field offsets.
 312  */
 313 void
 314 xfs_btree_offsets(
 315         __int64_t               fields, /* bitmask of fields */
 316         const short             *offsets,/* table of field offsets */
 317         int                     nbits,  /* number of bits to inspect */
 318         int                     *first, /* output: first byte offset */
 319         int                     *last); /* output: last byte offset */
 320
 321 /*
 322  * Get a buffer for the block, return it read in.
 323  * Long-form addressing.
 324  */
 325 int                                     /* error */
 326 xfs_btree_read_bufl(
 327         struct xfs_mount        *mp,    /* file system mount point */
 328         struct xfs_trans        *tp,    /* transaction pointer */
 329         xfs_fsblock_t           fsbno,  /* file system block number */
 330         uint                    lock,   /* lock flags for read_buf */
 331         struct xfs_buf          **bpp,  /* buffer for fsbno */
 332         int                     refval, /* ref count value for buffer */
 333         const struct xfs_buf_ops *ops);
 334
 335 /*
 336  * Read-ahead the block, don't wait for it, don't return a buffer.
 337  * Long-form addressing.
 338  */
 339 void                                    /* error */
 340 xfs_btree_reada_bufl(
 341         struct xfs_mount        *mp,    /* file system mount point */
 342         xfs_fsblock_t           fsbno,  /* file system block number */
 343         xfs_extlen_t            count,  /* count of filesystem blocks */
 344         const struct xfs_buf_ops *ops);
 345
 346 /*
 347  * Read-ahead the block, don't wait for it, don't return a buffer.
 348  * Short-form addressing.
 349  */
 350 void                                    /* error */
 351 xfs_btree_reada_bufs(
 352         struct xfs_mount        *mp,    /* file system mount point */
 353         xfs_agnumber_t          agno,   /* allocation group number */
 354         xfs_agblock_t           agbno,  /* allocation group block number */
 355         xfs_extlen_t            count,  /* count of filesystem blocks */
 356         const struct xfs_buf_ops *ops);
 357
 358 /*
 359  * Initialise a new btree block header
 360  */
 361 void
 362 xfs_btree_init_block(
 363         struct xfs_mount *mp,
 364         struct xfs_buf  *bp,
 365         __u32           magic,
 366         __u16           level,
 367         __u16           numrecs,
 368         __u64           owner,
 369         unsigned int    flags);
 370
 371 void
 372 xfs_btree_init_block_int(
 373         struct xfs_mount        *mp,
 374         struct xfs_btree_block  *buf,
 375         xfs_daddr_t             blkno,
 376         __u32                   magic,
 377         __u16                   level,
 378         __u16                   numrecs,
 379         __u64                   owner,
 380         unsigned int            flags);
 381
 382 /*
 383  * Common btree core entry points.
 384  */
 385 int xfs_btree_increment(struct xfs_btree_cur *, int, int *);
 386 int xfs_btree_decrement(struct xfs_btree_cur *, int, int *);
 387 int xfs_btree_lookup(struct xfs_btree_cur *, xfs_lookup_t, int *);
 388 int xfs_btree_update(struct xfs_btree_cur *, union xfs_btree_rec *);
 389 int xfs_btree_new_iroot(struct xfs_btree_cur *, int *, int *);
 390 int xfs_btree_insert(struct xfs_btree_cur *, int *);
 391 int xfs_btree_delete(struct xfs_btree_cur *, int *);
 392 int xfs_btree_get_rec(struct xfs_btree_cur *, union xfs_btree_rec **, int *);
 393 int xfs_btree_change_owner(struct xfs_btree_cur *cur, __uint64_t new_owner,
 394                            struct list_head *buffer_list);
 395
 396 /*
 397  * btree block CRC helpers
 398  */
 399 void xfs_btree_lblock_calc_crc(struct xfs_buf *);
 400 bool xfs_btree_lblock_verify_crc(struct xfs_buf *);
 401 void xfs_btree_sblock_calc_crc(struct xfs_buf *);
 402 bool xfs_btree_sblock_verify_crc(struct xfs_buf *);
 403
 404 /*
 405  * Internal btree helpers also used by xfs_bmap.c.
 406  */
 407 void xfs_btree_log_block(struct xfs_btree_cur *, struct xfs_buf *, int);
 408 void xfs_btree_log_recs(struct xfs_btree_cur *, struct xfs_buf *, int, int);
 409
 410 /*
 411  * Helpers.
 412  */
 413 static inline int xfs_btree_get_numrecs(struct xfs_btree_block *block)
 414 {
 415         return be16_to_cpu(block->bb_numrecs);
 416 }
 417
 418 static inline void xfs_btree_set_numrecs(struct xfs_btree_block *block,
 419                 __uint16_t numrecs)
 420 {
 421         block->bb_numrecs = cpu_to_be16(numrecs);
 422 }
 423
 424 static inline int xfs_btree_get_level(struct xfs_btree_block *block)
 425 {
 426         return be16_to_cpu(block->bb_level);
 427 }
 428
 429
 430 /*
 431  * Min and max functions for extlen, agblock, fileoff, and filblks types.
 432  */
 433 #define XFS_EXTLEN_MIN(a,b)     min_t(xfs_extlen_t, (a), (b))
 434 #define XFS_EXTLEN_MAX(a,b)     max_t(xfs_extlen_t, (a), (b))
 435 #define XFS_AGBLOCK_MIN(a,b)    min_t(xfs_agblock_t, (a), (b))
 436 #define XFS_AGBLOCK_MAX(a,b)    max_t(xfs_agblock_t, (a), (b))
 437 #define XFS_FILEOFF_MIN(a,b)    min_t(xfs_fileoff_t, (a), (b))
 438 #define XFS_FILEOFF_MAX(a,b)    max_t(xfs_fileoff_t, (a), (b))
 439 #define XFS_FILBLKS_MIN(a,b)    min_t(xfs_filblks_t, (a), (b))
 440 #define XFS_FILBLKS_MAX(a,b)    max_t(xfs_filblks_t, (a), (b))
 441
 442 #define XFS_FSB_SANITY_CHECK(mp,fsb)    \
 443         (XFS_FSB_TO_AGNO(mp, fsb) < mp->m_sb.sb_agcount && \
 444                 XFS_FSB_TO_AGBNO(mp, fsb) < mp->m_sb.sb_agblocks)
 445
 446 /*
 447  * Trace hooks.  Currently not implemented as they need to be ported
 448  * over to the generic tracing functionality, which is some effort.
 449  *
 450  * i,j = integer (32 bit)
 451  * b = btree block buffer (xfs_buf_t)
 452  * p = btree ptr
 453  * r = btree record
 454  * k = btree key
 455  */
 456 #define XFS_BTREE_TRACE_ARGBI(c, b, i)
 457 #define XFS_BTREE_TRACE_ARGBII(c, b, i, j)
 458 #define XFS_BTREE_TRACE_ARGI(c, i)
 459 #define XFS_BTREE_TRACE_ARGIPK(c, i, p, s)
 460 #define XFS_BTREE_TRACE_ARGIPR(c, i, p, r)
 461 #define XFS_BTREE_TRACE_ARGIK(c, i, k)
 462 #define XFS_BTREE_TRACE_ARGR(c, r)
 463 #define XFS_BTREE_TRACE_CURSOR(c, t)
 464
 465 #endif  /* __XFS_BTREE_H__ */