LXR linux/fs/xfs/libxfs/xfs

   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
  21struct xfs_buf;
  22struct xfs_bmap_free;
  23struct xfs_inode;
  24struct xfs_mount;
  25struct xfs_trans;
  26
  27extern 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 */
  35union xfs_btree_ptr {
  36        __be32                  s;      /* short form ptr */
  37        __be64                  l;      /* long form ptr */
  38};
  39
  40union 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
  47union 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#define XFS_BTNUM_FINO  ((xfs_btnum_t)XFS_BTNUM_FINOi)
  66
  67/*
  68 * For logging record fields.
  69 */
  70#define XFS_BB_MAGIC            (1 << 0)
  71#define XFS_BB_LEVEL            (1 << 1)
  72#define XFS_BB_NUMRECS          (1 << 2)
  73#define XFS_BB_LEFTSIB          (1 << 3)
  74#define XFS_BB_RIGHTSIB         (1 << 4)
  75#define XFS_BB_BLKNO            (1 << 5)
  76#define XFS_BB_LSN              (1 << 6)
  77#define XFS_BB_UUID             (1 << 7)
  78#define XFS_BB_OWNER            (1 << 8)
  79#define XFS_BB_NUM_BITS         5
  80#define XFS_BB_ALL_BITS         ((1 << XFS_BB_NUM_BITS) - 1)
  81#define XFS_BB_NUM_BITS_CRC     9
  82#define XFS_BB_ALL_BITS_CRC     ((1 << XFS_BB_NUM_BITS_CRC) - 1)
  83
  84/*
  85 * Generic stats interface
  86 */
  87#define __XFS_BTREE_STATS_INC(mp, type, stat) \
  88        XFS_STATS_INC(mp, xs_ ## type ## _2_ ## stat)
  89#define XFS_BTREE_STATS_INC(cur, stat)  \
  90do {    \
  91        struct xfs_mount *__mp = cur->bc_mp; \
  92        switch (cur->bc_btnum) {  \
  93        case XFS_BTNUM_BNO: __XFS_BTREE_STATS_INC(__mp, abtb, stat); break; \
  94        case XFS_BTNUM_CNT: __XFS_BTREE_STATS_INC(__mp, abtc, stat); break; \
  95        case XFS_BTNUM_BMAP: __XFS_BTREE_STATS_INC(__mp, bmbt, stat); break; \
  96        case XFS_BTNUM_INO: __XFS_BTREE_STATS_INC(__mp, ibt, stat); break; \
  97        case XFS_BTNUM_FINO: __XFS_BTREE_STATS_INC(__mp, fibt, stat); break; \
  98        case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break;       \
  99        }       \
 100} while (0)
 101
 102#define __XFS_BTREE_STATS_ADD(mp, type, stat, val) \
 103        XFS_STATS_ADD(mp, xs_ ## type ## _2_ ## stat, val)
 104#define XFS_BTREE_STATS_ADD(cur, stat, val)  \
 105do {    \
 106        struct xfs_mount *__mp = cur->bc_mp; \
 107        switch (cur->bc_btnum) {  \
 108        case XFS_BTNUM_BNO:     \
 109                __XFS_BTREE_STATS_ADD(__mp, abtb, stat, val); break; \
 110        case XFS_BTNUM_CNT:     \
 111                __XFS_BTREE_STATS_ADD(__mp, abtc, stat, val); break; \
 112        case XFS_BTNUM_BMAP:    \
 113                __XFS_BTREE_STATS_ADD(__mp, bmbt, stat, val); break; \
 114        case XFS_BTNUM_INO:     \
 115                __XFS_BTREE_STATS_ADD(__mp, ibt, stat, val); break; \
 116        case XFS_BTNUM_FINO:    \
 117                __XFS_BTREE_STATS_ADD(__mp, fibt, stat, val); break; \
 118        case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break; \
 119        }       \
 120} while (0)
 121
 122#define XFS_BTREE_MAXLEVELS     8       /* max of all btrees */
 123
 124struct xfs_btree_ops {
 125        /* size of the key and record structures */
 126        size_t  key_len;
 127        size_t  rec_len;
 128
 129        /* cursor operations */
 130        struct xfs_btree_cur *(*dup_cursor)(struct xfs_btree_cur *);
 131        void    (*update_cursor)(struct xfs_btree_cur *src,
 132                                 struct xfs_btree_cur *dst);
 133
 134        /* update btree root pointer */
 135        void    (*set_root)(struct xfs_btree_cur *cur,
 136                            union xfs_btree_ptr *nptr, int level_change);
 137
 138        /* block allocation / freeing */
 139        int     (*alloc_block)(struct xfs_btree_cur *cur,
 140                               union xfs_btree_ptr *start_bno,
 141                               union xfs_btree_ptr *new_bno,
 142                               int *stat);
 143        int     (*free_block)(struct xfs_btree_cur *cur, struct xfs_buf *bp);
 144
 145        /* update last record information */
 146        void    (*update_lastrec)(struct xfs_btree_cur *cur,
 147                                  struct xfs_btree_block *block,
 148                                  union xfs_btree_rec *rec,
 149                                  int ptr, int reason);
 150
 151        /* records in block/level */
 152        int     (*get_minrecs)(struct xfs_btree_cur *cur, int level);
 153        int     (*get_maxrecs)(struct xfs_btree_cur *cur, int level);
 154
 155        /* records on disk.  Matter for the root in inode case. */
 156        int     (*get_dmaxrecs)(struct xfs_btree_cur *cur, int level);
 157
 158        /* init values of btree structures */
 159        void    (*init_key_from_rec)(union xfs_btree_key *key,
 160                                     union xfs_btree_rec *rec);
 161        void    (*init_rec_from_key)(union xfs_btree_key *key,
 162                                     union xfs_btree_rec *rec);
 163        void    (*init_rec_from_cur)(struct xfs_btree_cur *cur,
 164                                     union xfs_btree_rec *rec);
 165        void    (*init_ptr_from_cur)(struct xfs_btree_cur *cur,
 166                                     union xfs_btree_ptr *ptr);
 167
 168        /* difference between key value and cursor value */
 169        __int64_t (*key_diff)(struct xfs_btree_cur *cur,
 170                              union xfs_btree_key *key);
 171
 172        const struct xfs_buf_ops        *buf_ops;
 173
 174#if defined(DEBUG) || defined(XFS_WARN)
 175        /* check that k1 is lower than k2 */
 176        int     (*keys_inorder)(struct xfs_btree_cur *cur,
 177                                union xfs_btree_key *k1,
 178                                union xfs_btree_key *k2);
 179
 180        /* check that r1 is lower than r2 */
 181        int     (*recs_inorder)(struct xfs_btree_cur *cur,
 182                                union xfs_btree_rec *r1,
 183                                union xfs_btree_rec *r2);
 184#endif
 185};
 186
 187/*
 188 * Reasons for the update_lastrec method to be called.
 189 */
 190#define LASTREC_UPDATE  0
 191#define LASTREC_INSREC  1
 192#define LASTREC_DELREC  2
 193
 194
 195/*
 196 * Btree cursor structure.
 197 * This collects all information needed by the btree code in one place.
 198 */
 199typedef struct xfs_btree_cur
 200{
 201        struct xfs_trans        *bc_tp; /* transaction we're in, if any */
 202        struct xfs_mount        *bc_mp; /* file system mount struct */
 203        const struct xfs_btree_ops *bc_ops;
 204        uint                    bc_flags; /* btree features - below */
 205        union {
 206                xfs_alloc_rec_incore_t  a;
 207                xfs_bmbt_irec_t         b;
 208                xfs_inobt_rec_incore_t  i;
 209        }               bc_rec;         /* current insert/search record value */
 210        struct xfs_buf  *bc_bufs[XFS_BTREE_MAXLEVELS];  /* buf ptr per level */
 211        int             bc_ptrs[XFS_BTREE_MAXLEVELS];   /* key/record # */
 212        __uint8_t       bc_ra[XFS_BTREE_MAXLEVELS];     /* readahead bits */
 213#define XFS_BTCUR_LEFTRA        1       /* left sibling has been read-ahead */
 214#define XFS_BTCUR_RIGHTRA       2       /* right sibling has been read-ahead */
 215        __uint8_t       bc_nlevels;     /* number of levels in the tree */
 216        __uint8_t       bc_blocklog;    /* log2(blocksize) of btree blocks */
 217        xfs_btnum_t     bc_btnum;       /* identifies which btree type */
 218        union {
 219                struct {                        /* needed for BNO, CNT, INO */
 220                        struct xfs_buf  *agbp;  /* agf/agi buffer pointer */
 221                        xfs_agnumber_t  agno;   /* ag number */
 222                } a;
 223                struct {                        /* needed for BMAP */
 224                        struct xfs_inode *ip;   /* pointer to our inode */
 225                        struct xfs_bmap_free *flist;    /* list to free after */
 226                        xfs_fsblock_t   firstblock;     /* 1st blk allocated */
 227                        int             allocated;      /* count of alloced */
 228                        short           forksize;       /* fork's inode space */
 229                        char            whichfork;      /* data or attr fork */
 230                        char            flags;          /* flags */
 231#define XFS_BTCUR_BPRV_WASDEL   1                       /* was delayed */
 232                } b;
 233        }               bc_private;     /* per-btree type data */
 234} xfs_btree_cur_t;
 235
 236/* cursor flags */
 237#define XFS_BTREE_LONG_PTRS             (1<<0)  /* pointers are 64bits long */
 238#define XFS_BTREE_ROOT_IN_INODE         (1<<1)  /* root may be variable size */
 239#define XFS_BTREE_LASTREC_UPDATE        (1<<2)  /* track last rec externally */
 240#define XFS_BTREE_CRC_BLOCKS            (1<<3)  /* uses extended btree blocks */
 241
 242
 243#define XFS_BTREE_NOERROR       0
 244#define XFS_BTREE_ERROR         1
 245
 246/*
 247 * Convert from buffer to btree block header.
 248 */
 249#define XFS_BUF_TO_BLOCK(bp)    ((struct xfs_btree_block *)((bp)->b_addr))
 250
 251
 252/*
 253 * Check that block header is ok.
 254 */
 255int
 256xfs_btree_check_block(
 257        struct xfs_btree_cur    *cur,   /* btree cursor */
 258        struct xfs_btree_block  *block, /* generic btree block pointer */
 259        int                     level,  /* level of the btree block */
 260        struct xfs_buf          *bp);   /* buffer containing block, if any */
 261
 262/*
 263 * Check that (long) pointer is ok.
 264 */
 265int                                     /* error (0 or EFSCORRUPTED) */
 266xfs_btree_check_lptr(
 267        struct xfs_btree_cur    *cur,   /* btree cursor */
 268        xfs_fsblock_t           ptr,    /* btree block disk address */
 269        int                     level); /* btree block level */
 270
 271/*
 272 * Delete the btree cursor.
 273 */
 274void
 275xfs_btree_del_cursor(
 276        xfs_btree_cur_t         *cur,   /* btree cursor */
 277        int                     error); /* del because of error */
 278
 279/*
 280 * Duplicate the btree cursor.
 281 * Allocate a new one, copy the record, re-get the buffers.
 282 */
 283int                                     /* error */
 284xfs_btree_dup_cursor(
 285        xfs_btree_cur_t         *cur,   /* input cursor */
 286        xfs_btree_cur_t         **ncur);/* output cursor */
 287
 288/*
 289 * Get a buffer for the block, return it with no data read.
 290 * Long-form addressing.
 291 */
 292struct xfs_buf *                                /* buffer for fsbno */
 293xfs_btree_get_bufl(
 294        struct xfs_mount        *mp,    /* file system mount point */
 295        struct xfs_trans        *tp,    /* transaction pointer */
 296        xfs_fsblock_t           fsbno,  /* file system block number */
 297        uint                    lock);  /* lock flags for get_buf */
 298
 299/*
 300 * Get a buffer for the block, return it with no data read.
 301 * Short-form addressing.
 302 */
 303struct xfs_buf *                                /* buffer for agno/agbno */
 304xfs_btree_get_bufs(
 305        struct xfs_mount        *mp,    /* file system mount point */
 306        struct xfs_trans        *tp,    /* transaction pointer */
 307        xfs_agnumber_t          agno,   /* allocation group number */
 308        xfs_agblock_t           agbno,  /* allocation group block number */
 309        uint                    lock);  /* lock flags for get_buf */
 310
 311/*
 312 * Check for the cursor referring to the last block at the given level.
 313 */
 314int                                     /* 1=is last block, 0=not last block */
 315xfs_btree_islastblock(
 316        xfs_btree_cur_t         *cur,   /* btree cursor */
 317        int                     level); /* level to check */
 318
 319/*
 320 * Compute first and last byte offsets for the fields given.
 321 * Interprets the offsets table, which contains struct field offsets.
 322 */
 323void
 324xfs_btree_offsets(
 325        __int64_t               fields, /* bitmask of fields */
 326        const short             *offsets,/* table of field offsets */
 327        int                     nbits,  /* number of bits to inspect */
 328        int                     *first, /* output: first byte offset */
 329        int                     *last); /* output: last byte offset */
 330
 331/*
 332 * Get a buffer for the block, return it read in.
 333 * Long-form addressing.
 334 */
 335int                                     /* error */
 336xfs_btree_read_bufl(
 337        struct xfs_mount        *mp,    /* file system mount point */
 338        struct xfs_trans        *tp,    /* transaction pointer */
 339        xfs_fsblock_t           fsbno,  /* file system block number */
 340        uint                    lock,   /* lock flags for read_buf */
 341        struct xfs_buf          **bpp,  /* buffer for fsbno */
 342        int                     refval, /* ref count value for buffer */
 343        const struct xfs_buf_ops *ops);
 344
 345/*
 346 * Read-ahead the block, don't wait for it, don't return a buffer.
 347 * Long-form addressing.
 348 */
 349void                                    /* error */
 350xfs_btree_reada_bufl(
 351        struct xfs_mount        *mp,    /* file system mount point */
 352        xfs_fsblock_t           fsbno,  /* file system block number */
 353        xfs_extlen_t            count,  /* count of filesystem blocks */
 354        const struct xfs_buf_ops *ops);
 355
 356/*
 357 * Read-ahead the block, don't wait for it, don't return a buffer.
 358 * Short-form addressing.
 359 */
 360void                                    /* error */
 361xfs_btree_reada_bufs(
 362        struct xfs_mount        *mp,    /* file system mount point */
 363        xfs_agnumber_t          agno,   /* allocation group number */
 364        xfs_agblock_t           agbno,  /* allocation group block number */
 365        xfs_extlen_t            count,  /* count of filesystem blocks */
 366        const struct xfs_buf_ops *ops);
 367
 368/*
 369 * Initialise a new btree block header
 370 */
 371void
 372xfs_btree_init_block(
 373        struct xfs_mount *mp,
 374        struct xfs_buf  *bp,
 375        __u32           magic,
 376        __u16           level,
 377        __u16           numrecs,
 378        __u64           owner,
 379        unsigned int    flags);
 380
 381void
 382xfs_btree_init_block_int(
 383        struct xfs_mount        *mp,
 384        struct xfs_btree_block  *buf,
 385        xfs_daddr_t             blkno,
 386        __u32                   magic,
 387        __u16                   level,
 388        __u16                   numrecs,
 389        __u64                   owner,
 390        unsigned int            flags);
 391
 392/*
 393 * Common btree core entry points.
 394 */
 395int xfs_btree_increment(struct xfs_btree_cur *, int, int *);
 396int xfs_btree_decrement(struct xfs_btree_cur *, int, int *);
 397int xfs_btree_lookup(struct xfs_btree_cur *, xfs_lookup_t, int *);
 398int xfs_btree_update(struct xfs_btree_cur *, union xfs_btree_rec *);
 399int xfs_btree_new_iroot(struct xfs_btree_cur *, int *, int *);
 400int xfs_btree_insert(struct xfs_btree_cur *, int *);
 401int xfs_btree_delete(struct xfs_btree_cur *, int *);
 402int xfs_btree_get_rec(struct xfs_btree_cur *, union xfs_btree_rec **, int *);
 403int xfs_btree_change_owner(struct xfs_btree_cur *cur, __uint64_t new_owner,
 404                           struct list_head *buffer_list);
 405
 406/*
 407 * btree block CRC helpers
 408 */
 409void xfs_btree_lblock_calc_crc(struct xfs_buf *);
 410bool xfs_btree_lblock_verify_crc(struct xfs_buf *);
 411void xfs_btree_sblock_calc_crc(struct xfs_buf *);
 412bool xfs_btree_sblock_verify_crc(struct xfs_buf *);
 413
 414/*
 415 * Internal btree helpers also used by xfs_bmap.c.
 416 */
 417void xfs_btree_log_block(struct xfs_btree_cur *, struct xfs_buf *, int);
 418void xfs_btree_log_recs(struct xfs_btree_cur *, struct xfs_buf *, int, int);
 419
 420/*
 421 * Helpers.
 422 */
 423static inline int xfs_btree_get_numrecs(struct xfs_btree_block *block)
 424{
 425        return be16_to_cpu(block->bb_numrecs);
 426}
 427
 428static inline void xfs_btree_set_numrecs(struct xfs_btree_block *block,
 429                __uint16_t numrecs)
 430{
 431        block->bb_numrecs = cpu_to_be16(numrecs);
 432}
 433
 434static inline int xfs_btree_get_level(struct xfs_btree_block *block)
 435{
 436        return be16_to_cpu(block->bb_level);
 437}
 438
 439
 440/*
 441 * Min and max functions for extlen, agblock, fileoff, and filblks types.
 442 */
 443#define XFS_EXTLEN_MIN(a,b)     min_t(xfs_extlen_t, (a), (b))
 444#define XFS_EXTLEN_MAX(a,b)     max_t(xfs_extlen_t, (a), (b))
 445#define XFS_AGBLOCK_MIN(a,b)    min_t(xfs_agblock_t, (a), (b))
 446#define XFS_AGBLOCK_MAX(a,b)    max_t(xfs_agblock_t, (a), (b))
 447#define XFS_FILEOFF_MIN(a,b)    min_t(xfs_fileoff_t, (a), (b))
 448#define XFS_FILEOFF_MAX(a,b)    max_t(xfs_fileoff_t, (a), (b))
 449#define XFS_FILBLKS_MIN(a,b)    min_t(xfs_filblks_t, (a), (b))
 450#define XFS_FILBLKS_MAX(a,b)    max_t(xfs_filblks_t, (a), (b))
 451
 452#define XFS_FSB_SANITY_CHECK(mp,fsb)    \
 453        (XFS_FSB_TO_AGNO(mp, fsb) < mp->m_sb.sb_agcount && \
 454                XFS_FSB_TO_AGBNO(mp, fsb) < mp->m_sb.sb_agblocks)
 455
 456/*
 457 * Trace hooks.  Currently not implemented as they need to be ported
 458 * over to the generic tracing functionality, which is some effort.
 459 *
 460 * i,j = integer (32 bit)
 461 * b = btree block buffer (xfs_buf_t)
 462 * p = btree ptr
 463 * r = btree record
 464 * k = btree key
 465 */
 466#define XFS_BTREE_TRACE_ARGBI(c, b, i)
 467#define XFS_BTREE_TRACE_ARGBII(c, b, i, j)
 468#define XFS_BTREE_TRACE_ARGI(c, i)
 469#define XFS_BTREE_TRACE_ARGIPK(c, i, p, s)
 470#define XFS_BTREE_TRACE_ARGIPR(c, i, p, r)
 471#define XFS_BTREE_TRACE_ARGIK(c, i, k)
 472#define XFS_BTREE_TRACE_ARGR(c, r)
 473#define XFS_BTREE_TRACE_CURSOR(c, t)
 474
 475#endif  /* __XFS_BTREE_H__ */
 476