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_defer_ops;
  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
  40/*
  41 * The in-core btree key.  Overlapping btrees actually store two keys
  42 * per pointer, so we reserve enough memory to hold both.  The __*bigkey
  43 * items should never be accessed directly.
  44 */
  45union xfs_btree_key {
  46        struct xfs_bmbt_key             bmbt;
  47        xfs_bmdr_key_t                  bmbr;   /* bmbt root block */
  48        xfs_alloc_key_t                 alloc;
  49        struct xfs_inobt_key            inobt;
  50        struct xfs_rmap_key             rmap;
  51        struct xfs_rmap_key             __rmap_bigkey[2];
  52        struct xfs_refcount_key         refc;
  53};
  54
  55union xfs_btree_rec {
  56        struct xfs_bmbt_rec             bmbt;
  57        xfs_bmdr_rec_t                  bmbr;   /* bmbt root block */
  58        struct xfs_alloc_rec            alloc;
  59        struct xfs_inobt_rec            inobt;
  60        struct xfs_rmap_rec             rmap;
  61        struct xfs_refcount_rec         refc;
  62};
  63
  64/*
  65 * This nonsense is to make -wlint happy.
  66 */
  67#define XFS_LOOKUP_EQ   ((xfs_lookup_t)XFS_LOOKUP_EQi)
  68#define XFS_LOOKUP_LE   ((xfs_lookup_t)XFS_LOOKUP_LEi)
  69#define XFS_LOOKUP_GE   ((xfs_lookup_t)XFS_LOOKUP_GEi)
  70
  71#define XFS_BTNUM_BNO   ((xfs_btnum_t)XFS_BTNUM_BNOi)
  72#define XFS_BTNUM_CNT   ((xfs_btnum_t)XFS_BTNUM_CNTi)
  73#define XFS_BTNUM_BMAP  ((xfs_btnum_t)XFS_BTNUM_BMAPi)
  74#define XFS_BTNUM_INO   ((xfs_btnum_t)XFS_BTNUM_INOi)
  75#define XFS_BTNUM_FINO  ((xfs_btnum_t)XFS_BTNUM_FINOi)
  76#define XFS_BTNUM_RMAP  ((xfs_btnum_t)XFS_BTNUM_RMAPi)
  77#define XFS_BTNUM_REFC  ((xfs_btnum_t)XFS_BTNUM_REFCi)
  78
  79uint32_t xfs_btree_magic(int crc, xfs_btnum_t btnum);
  80
  81/*
  82 * For logging record fields.
  83 */
  84#define XFS_BB_MAGIC            (1 << 0)
  85#define XFS_BB_LEVEL            (1 << 1)
  86#define XFS_BB_NUMRECS          (1 << 2)
  87#define XFS_BB_LEFTSIB          (1 << 3)
  88#define XFS_BB_RIGHTSIB         (1 << 4)
  89#define XFS_BB_BLKNO            (1 << 5)
  90#define XFS_BB_LSN              (1 << 6)
  91#define XFS_BB_UUID             (1 << 7)
  92#define XFS_BB_OWNER            (1 << 8)
  93#define XFS_BB_NUM_BITS         5
  94#define XFS_BB_ALL_BITS         ((1 << XFS_BB_NUM_BITS) - 1)
  95#define XFS_BB_NUM_BITS_CRC     9
  96#define XFS_BB_ALL_BITS_CRC     ((1 << XFS_BB_NUM_BITS_CRC) - 1)
  97
  98/*
  99 * Generic stats interface
 100 */
 101#define XFS_BTREE_STATS_INC(cur, stat)  \
 102        XFS_STATS_INC_OFF((cur)->bc_mp, (cur)->bc_statoff + __XBTS_ ## stat)
 103#define XFS_BTREE_STATS_ADD(cur, stat, val)     \
 104        XFS_STATS_ADD_OFF((cur)->bc_mp, (cur)->bc_statoff + __XBTS_ ## stat, val)
 105
 106#define XFS_BTREE_MAXLEVELS     9       /* max of all btrees */
 107
 108struct xfs_btree_ops {
 109        /* size of the key and record structures */
 110        size_t  key_len;
 111        size_t  rec_len;
 112
 113        /* cursor operations */
 114        struct xfs_btree_cur *(*dup_cursor)(struct xfs_btree_cur *);
 115        void    (*update_cursor)(struct xfs_btree_cur *src,
 116                                 struct xfs_btree_cur *dst);
 117
 118        /* update btree root pointer */
 119        void    (*set_root)(struct xfs_btree_cur *cur,
 120                            union xfs_btree_ptr *nptr, int level_change);
 121
 122        /* block allocation / freeing */
 123        int     (*alloc_block)(struct xfs_btree_cur *cur,
 124                               union xfs_btree_ptr *start_bno,
 125                               union xfs_btree_ptr *new_bno,
 126                               int *stat);
 127        int     (*free_block)(struct xfs_btree_cur *cur, struct xfs_buf *bp);
 128
 129        /* update last record information */
 130        void    (*update_lastrec)(struct xfs_btree_cur *cur,
 131                                  struct xfs_btree_block *block,
 132                                  union xfs_btree_rec *rec,
 133                                  int ptr, int reason);
 134
 135        /* records in block/level */
 136        int     (*get_minrecs)(struct xfs_btree_cur *cur, int level);
 137        int     (*get_maxrecs)(struct xfs_btree_cur *cur, int level);
 138
 139        /* records on disk.  Matter for the root in inode case. */
 140        int     (*get_dmaxrecs)(struct xfs_btree_cur *cur, int level);
 141
 142        /* init values of btree structures */
 143        void    (*init_key_from_rec)(union xfs_btree_key *key,
 144                                     union xfs_btree_rec *rec);
 145        void    (*init_rec_from_cur)(struct xfs_btree_cur *cur,
 146                                     union xfs_btree_rec *rec);
 147        void    (*init_ptr_from_cur)(struct xfs_btree_cur *cur,
 148                                     union xfs_btree_ptr *ptr);
 149        void    (*init_high_key_from_rec)(union xfs_btree_key *key,
 150                                          union xfs_btree_rec *rec);
 151
 152        /* difference between key value and cursor value */
 153        int64_t (*key_diff)(struct xfs_btree_cur *cur,
 154                              union xfs_btree_key *key);
 155
 156        /*
 157         * Difference between key2 and key1 -- positive if key1 > key2,
 158         * negative if key1 < key2, and zero if equal.
 159         */
 160        int64_t (*diff_two_keys)(struct xfs_btree_cur *cur,
 161                                   union xfs_btree_key *key1,
 162                                   union xfs_btree_key *key2);
 163
 164        const struct xfs_buf_ops        *buf_ops;
 165
 166        /* check that k1 is lower than k2 */
 167        int     (*keys_inorder)(struct xfs_btree_cur *cur,
 168                                union xfs_btree_key *k1,
 169                                union xfs_btree_key *k2);
 170
 171        /* check that r1 is lower than r2 */
 172        int     (*recs_inorder)(struct xfs_btree_cur *cur,
 173                                union xfs_btree_rec *r1,
 174                                union xfs_btree_rec *r2);
 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
 185union xfs_btree_irec {
 186        struct xfs_alloc_rec_incore     a;
 187        struct xfs_bmbt_irec            b;
 188        struct xfs_inobt_rec_incore     i;
 189        struct xfs_rmap_irec            r;
 190        struct xfs_refcount_irec        rc;
 191};
 192
 193/* Per-AG btree private information. */
 194union xfs_btree_cur_private {
 195        struct {
 196                unsigned long   nr_ops;         /* # record updates */
 197                int             shape_changes;  /* # of extent splits */
 198        } refc;
 199};
 200
 201/*
 202 * Btree cursor structure.
 203 * This collects all information needed by the btree code in one place.
 204 */
 205typedef struct xfs_btree_cur
 206{
 207        struct xfs_trans        *bc_tp; /* transaction we're in, if any */
 208        struct xfs_mount        *bc_mp; /* file system mount struct */
 209        const struct xfs_btree_ops *bc_ops;
 210        uint                    bc_flags; /* btree features - below */
 211        union xfs_btree_irec    bc_rec; /* current insert/search record value */
 212        struct xfs_buf  *bc_bufs[XFS_BTREE_MAXLEVELS];  /* buf ptr per level */
 213        int             bc_ptrs[XFS_BTREE_MAXLEVELS];   /* key/record # */
 214        uint8_t         bc_ra[XFS_BTREE_MAXLEVELS];     /* readahead bits */
 215#define XFS_BTCUR_LEFTRA        1       /* left sibling has been read-ahead */
 216#define XFS_BTCUR_RIGHTRA       2       /* right sibling has been read-ahead */
 217        uint8_t         bc_nlevels;     /* number of levels in the tree */
 218        uint8_t         bc_blocklog;    /* log2(blocksize) of btree blocks */
 219        xfs_btnum_t     bc_btnum;       /* identifies which btree type */
 220        int             bc_statoff;     /* offset of btre stats array */
 221        union {
 222                struct {                        /* needed for BNO, CNT, INO */
 223                        struct xfs_buf  *agbp;  /* agf/agi buffer pointer */
 224                        struct xfs_defer_ops *dfops;    /* deferred updates */
 225                        xfs_agnumber_t  agno;   /* ag number */
 226                        union xfs_btree_cur_private     priv;
 227                } a;
 228                struct {                        /* needed for BMAP */
 229                        struct xfs_inode *ip;   /* pointer to our inode */
 230                        struct xfs_defer_ops *dfops;    /* deferred updates */
 231                        xfs_fsblock_t   firstblock;     /* 1st blk allocated */
 232                        int             allocated;      /* count of alloced */
 233                        short           forksize;       /* fork's inode space */
 234                        char            whichfork;      /* data or attr fork */
 235                        char            flags;          /* flags */
 236#define XFS_BTCUR_BPRV_WASDEL           (1<<0)          /* was delayed */
 237#define XFS_BTCUR_BPRV_INVALID_OWNER    (1<<1)          /* for ext swap */
 238                } b;
 239        }               bc_private;     /* per-btree type data */
 240} xfs_btree_cur_t;
 241
 242/* cursor flags */
 243#define XFS_BTREE_LONG_PTRS             (1<<0)  /* pointers are 64bits long */
 244#define XFS_BTREE_ROOT_IN_INODE         (1<<1)  /* root may be variable size */
 245#define XFS_BTREE_LASTREC_UPDATE        (1<<2)  /* track last rec externally */
 246#define XFS_BTREE_CRC_BLOCKS            (1<<3)  /* uses extended btree blocks */
 247#define XFS_BTREE_OVERLAPPING           (1<<4)  /* overlapping intervals */
 248
 249
 250#define XFS_BTREE_NOERROR       0
 251#define XFS_BTREE_ERROR         1
 252
 253/*
 254 * Convert from buffer to btree block header.
 255 */
 256#define XFS_BUF_TO_BLOCK(bp)    ((struct xfs_btree_block *)((bp)->b_addr))
 257
 258
 259/*
 260 * Check that block header is ok.
 261 */
 262int
 263xfs_btree_check_block(
 264        struct xfs_btree_cur    *cur,   /* btree cursor */
 265        struct xfs_btree_block  *block, /* generic btree block pointer */
 266        int                     level,  /* level of the btree block */
 267        struct xfs_buf          *bp);   /* buffer containing block, if any */
 268
 269/*
 270 * Check that (long) pointer is ok.
 271 */
 272int                                     /* error (0 or EFSCORRUPTED) */
 273xfs_btree_check_lptr(
 274        struct xfs_btree_cur    *cur,   /* btree cursor */
 275        xfs_fsblock_t           ptr,    /* btree block disk address */
 276        int                     level); /* btree block level */
 277
 278/*
 279 * Delete the btree cursor.
 280 */
 281void
 282xfs_btree_del_cursor(
 283        xfs_btree_cur_t         *cur,   /* btree cursor */
 284        int                     error); /* del because of error */
 285
 286/*
 287 * Duplicate the btree cursor.
 288 * Allocate a new one, copy the record, re-get the buffers.
 289 */
 290int                                     /* error */
 291xfs_btree_dup_cursor(
 292        xfs_btree_cur_t         *cur,   /* input cursor */
 293        xfs_btree_cur_t         **ncur);/* output cursor */
 294
 295/*
 296 * Get a buffer for the block, return it with no data read.
 297 * Long-form addressing.
 298 */
 299struct xfs_buf *                                /* buffer for fsbno */
 300xfs_btree_get_bufl(
 301        struct xfs_mount        *mp,    /* file system mount point */
 302        struct xfs_trans        *tp,    /* transaction pointer */
 303        xfs_fsblock_t           fsbno,  /* file system block number */
 304        uint                    lock);  /* lock flags for get_buf */
 305
 306/*
 307 * Get a buffer for the block, return it with no data read.
 308 * Short-form addressing.
 309 */
 310struct xfs_buf *                                /* buffer for agno/agbno */
 311xfs_btree_get_bufs(
 312        struct xfs_mount        *mp,    /* file system mount point */
 313        struct xfs_trans        *tp,    /* transaction pointer */
 314        xfs_agnumber_t          agno,   /* allocation group number */
 315        xfs_agblock_t           agbno,  /* allocation group block number */
 316        uint                    lock);  /* lock flags for get_buf */
 317
 318/*
 319 * Check for the cursor referring to the last block at the given level.
 320 */
 321int                                     /* 1=is last block, 0=not last block */
 322xfs_btree_islastblock(
 323        xfs_btree_cur_t         *cur,   /* btree cursor */
 324        int                     level); /* level to check */
 325
 326/*
 327 * Compute first and last byte offsets for the fields given.
 328 * Interprets the offsets table, which contains struct field offsets.
 329 */
 330void
 331xfs_btree_offsets(
 332        int64_t                 fields, /* bitmask of fields */
 333        const short             *offsets,/* table of field offsets */
 334        int                     nbits,  /* number of bits to inspect */
 335        int                     *first, /* output: first byte offset */
 336        int                     *last); /* output: last byte offset */
 337
 338/*
 339 * Get a buffer for the block, return it read in.
 340 * Long-form addressing.
 341 */
 342int                                     /* error */
 343xfs_btree_read_bufl(
 344        struct xfs_mount        *mp,    /* file system mount point */
 345        struct xfs_trans        *tp,    /* transaction pointer */
 346        xfs_fsblock_t           fsbno,  /* file system block number */
 347        uint                    lock,   /* lock flags for read_buf */
 348        struct xfs_buf          **bpp,  /* buffer for fsbno */
 349        int                     refval, /* ref count value for buffer */
 350        const struct xfs_buf_ops *ops);
 351
 352/*
 353 * Read-ahead the block, don't wait for it, don't return a buffer.
 354 * Long-form addressing.
 355 */
 356void                                    /* error */
 357xfs_btree_reada_bufl(
 358        struct xfs_mount        *mp,    /* file system mount point */
 359        xfs_fsblock_t           fsbno,  /* file system block number */
 360        xfs_extlen_t            count,  /* count of filesystem blocks */
 361        const struct xfs_buf_ops *ops);
 362
 363/*
 364 * Read-ahead the block, don't wait for it, don't return a buffer.
 365 * Short-form addressing.
 366 */
 367void                                    /* error */
 368xfs_btree_reada_bufs(
 369        struct xfs_mount        *mp,    /* file system mount point */
 370        xfs_agnumber_t          agno,   /* allocation group number */
 371        xfs_agblock_t           agbno,  /* allocation group block number */
 372        xfs_extlen_t            count,  /* count of filesystem blocks */
 373        const struct xfs_buf_ops *ops);
 374
 375/*
 376 * Initialise a new btree block header
 377 */
 378void
 379xfs_btree_init_block(
 380        struct xfs_mount *mp,
 381        struct xfs_buf  *bp,
 382        xfs_btnum_t     btnum,
 383        __u16           level,
 384        __u16           numrecs,
 385        __u64           owner,
 386        unsigned int    flags);
 387
 388void
 389xfs_btree_init_block_int(
 390        struct xfs_mount        *mp,
 391        struct xfs_btree_block  *buf,
 392        xfs_daddr_t             blkno,
 393        xfs_btnum_t             btnum,
 394        __u16                   level,
 395        __u16                   numrecs,
 396        __u64                   owner,
 397        unsigned int            flags);
 398
 399/*
 400 * Common btree core entry points.
 401 */
 402int xfs_btree_increment(struct xfs_btree_cur *, int, int *);
 403int xfs_btree_decrement(struct xfs_btree_cur *, int, int *);
 404int xfs_btree_lookup(struct xfs_btree_cur *, xfs_lookup_t, int *);
 405int xfs_btree_update(struct xfs_btree_cur *, union xfs_btree_rec *);
 406int xfs_btree_new_iroot(struct xfs_btree_cur *, int *, int *);
 407int xfs_btree_insert(struct xfs_btree_cur *, int *);
 408int xfs_btree_delete(struct xfs_btree_cur *, int *);
 409int xfs_btree_get_rec(struct xfs_btree_cur *, union xfs_btree_rec **, int *);
 410int xfs_btree_change_owner(struct xfs_btree_cur *cur, uint64_t new_owner,
 411                           struct list_head *buffer_list);
 412
 413/*
 414 * btree block CRC helpers
 415 */
 416void xfs_btree_lblock_calc_crc(struct xfs_buf *);
 417bool xfs_btree_lblock_verify_crc(struct xfs_buf *);
 418void xfs_btree_sblock_calc_crc(struct xfs_buf *);
 419bool xfs_btree_sblock_verify_crc(struct xfs_buf *);
 420
 421/*
 422 * Internal btree helpers also used by xfs_bmap.c.
 423 */
 424void xfs_btree_log_block(struct xfs_btree_cur *, struct xfs_buf *, int);
 425void xfs_btree_log_recs(struct xfs_btree_cur *, struct xfs_buf *, int, int);
 426
 427/*
 428 * Helpers.
 429 */
 430static inline int xfs_btree_get_numrecs(struct xfs_btree_block *block)
 431{
 432        return be16_to_cpu(block->bb_numrecs);
 433}
 434
 435static inline void xfs_btree_set_numrecs(struct xfs_btree_block *block,
 436                uint16_t numrecs)
 437{
 438        block->bb_numrecs = cpu_to_be16(numrecs);
 439}
 440
 441static inline int xfs_btree_get_level(struct xfs_btree_block *block)
 442{
 443        return be16_to_cpu(block->bb_level);
 444}
 445
 446
 447/*
 448 * Min and max functions for extlen, agblock, fileoff, and filblks types.
 449 */
 450#define XFS_EXTLEN_MIN(a,b)     min_t(xfs_extlen_t, (a), (b))
 451#define XFS_EXTLEN_MAX(a,b)     max_t(xfs_extlen_t, (a), (b))
 452#define XFS_AGBLOCK_MIN(a,b)    min_t(xfs_agblock_t, (a), (b))
 453#define XFS_AGBLOCK_MAX(a,b)    max_t(xfs_agblock_t, (a), (b))
 454#define XFS_FILEOFF_MIN(a,b)    min_t(xfs_fileoff_t, (a), (b))
 455#define XFS_FILEOFF_MAX(a,b)    max_t(xfs_fileoff_t, (a), (b))
 456#define XFS_FILBLKS_MIN(a,b)    min_t(xfs_filblks_t, (a), (b))
 457#define XFS_FILBLKS_MAX(a,b)    max_t(xfs_filblks_t, (a), (b))
 458
 459#define XFS_FSB_SANITY_CHECK(mp,fsb)    \
 460        (fsb && XFS_FSB_TO_AGNO(mp, fsb) < mp->m_sb.sb_agcount && \
 461                XFS_FSB_TO_AGBNO(mp, fsb) < mp->m_sb.sb_agblocks)
 462
 463/*
 464 * Trace hooks.  Currently not implemented as they need to be ported
 465 * over to the generic tracing functionality, which is some effort.
 466 *
 467 * i,j = integer (32 bit)
 468 * b = btree block buffer (xfs_buf_t)
 469 * p = btree ptr
 470 * r = btree record
 471 * k = btree key
 472 */
 473#define XFS_BTREE_TRACE_ARGBI(c, b, i)
 474#define XFS_BTREE_TRACE_ARGBII(c, b, i, j)
 475#define XFS_BTREE_TRACE_ARGI(c, i)
 476#define XFS_BTREE_TRACE_ARGIPK(c, i, p, s)
 477#define XFS_BTREE_TRACE_ARGIPR(c, i, p, r)
 478#define XFS_BTREE_TRACE_ARGIK(c, i, k)
 479#define XFS_BTREE_TRACE_ARGR(c, r)
 480#define XFS_BTREE_TRACE_CURSOR(c, t)
 481
 482bool xfs_btree_sblock_v5hdr_verify(struct xfs_buf *bp);
 483bool xfs_btree_sblock_verify(struct xfs_buf *bp, unsigned int max_recs);
 484uint xfs_btree_compute_maxlevels(struct xfs_mount *mp, uint *limits,
 485                                 unsigned long len);
 486xfs_extlen_t xfs_btree_calc_size(struct xfs_mount *mp, uint *limits,
 487                unsigned long long len);
 488
 489/* return codes */
 490#define XFS_BTREE_QUERY_RANGE_CONTINUE  0       /* keep iterating */
 491#define XFS_BTREE_QUERY_RANGE_ABORT     1       /* stop iterating */
 492typedef int (*xfs_btree_query_range_fn)(struct xfs_btree_cur *cur,
 493                union xfs_btree_rec *rec, void *priv);
 494
 495int xfs_btree_query_range(struct xfs_btree_cur *cur,
 496                union xfs_btree_irec *low_rec, union xfs_btree_irec *high_rec,
 497                xfs_btree_query_range_fn fn, void *priv);
 498int xfs_btree_query_all(struct xfs_btree_cur *cur, xfs_btree_query_range_fn fn,
 499                void *priv);
 500
 501typedef int (*xfs_btree_visit_blocks_fn)(struct xfs_btree_cur *cur, int level,
 502                void *data);
 503int xfs_btree_visit_blocks(struct xfs_btree_cur *cur,
 504                xfs_btree_visit_blocks_fn fn, void *data);
 505
 506int xfs_btree_count_blocks(struct xfs_btree_cur *cur, xfs_extlen_t *blocks);
 507
 508union xfs_btree_rec *xfs_btree_rec_addr(struct xfs_btree_cur *cur, int n,
 509                struct xfs_btree_block *block);
 510union xfs_btree_key *xfs_btree_key_addr(struct xfs_btree_cur *cur, int n,
 511                struct xfs_btree_block *block);
 512union xfs_btree_key *xfs_btree_high_key_addr(struct xfs_btree_cur *cur, int n,
 513                struct xfs_btree_block *block);
 514union xfs_btree_ptr *xfs_btree_ptr_addr(struct xfs_btree_cur *cur, int n,
 515                struct xfs_btree_block *block);
 516int xfs_btree_lookup_get_block(struct xfs_btree_cur *cur, int level,
 517                union xfs_btree_ptr *pp, struct xfs_btree_block **blkp);
 518struct xfs_btree_block *xfs_btree_get_block(struct xfs_btree_cur *cur,
 519                int level, struct xfs_buf **bpp);
 520
 521#endif  /* __XFS_BTREE_H__ */
 522