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