libxfs/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 #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)  \
  90 do {    \
  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)  \
 104 do {    \
 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
 117 struct 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  */
 192 typedef 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  */
 248 int
 249 xfs_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  */
 258 int                                     /* error (0 or EFSCORRUPTED) */
 259 xfs_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  */
 267 void
 268 xfs_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  */
 276 int                                     /* error */
 277 xfs_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  */
 285 struct xfs_buf *                                /* buffer for fsbno */
 286 xfs_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  */
 296 struct xfs_buf *                                /* buffer for agno/agbno */
 297 xfs_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  */
 307 int                                     /* 1=is last block, 0=not last block */
 308 xfs_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  */
 316 void
 317 xfs_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  */
 328 int                                     /* error */
 329 xfs_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  */
 342 void                                    /* error */
 343 xfs_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  */
 353 void                                    /* error */
 354 xfs_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  */
 364 void
 365 xfs_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
 374 void
 375 xfs_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  */
 388 int xfs_btree_increment(struct xfs_btree_cur *, int, int *);
 389 int xfs_btree_decrement(struct xfs_btree_cur *, int, int *);
 390 int xfs_btree_lookup(struct xfs_btree_cur *, xfs_lookup_t, int *);
 391 int xfs_btree_update(struct xfs_btree_cur *, union xfs_btree_rec *);
 392 int xfs_btree_new_iroot(struct xfs_btree_cur *, int *, int *);
 393 int xfs_btree_insert(struct xfs_btree_cur *, int *);
 394 int xfs_btree_delete(struct xfs_btree_cur *, int *);
 395 int xfs_btree_get_rec(struct xfs_btree_cur *, union xfs_btree_rec **, int *);
 396 int 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  */
 402 void xfs_btree_lblock_calc_crc(struct xfs_buf *);
 403 bool xfs_btree_lblock_verify_crc(struct xfs_buf *);
 404 void xfs_btree_sblock_calc_crc(struct xfs_buf *);
 405 bool xfs_btree_sblock_verify_crc(struct xfs_buf *);
 406
 407 /*
 408  * Internal btree helpers also used by xfs_bmap.c.
 409  */
 410 void xfs_btree_log_block(struct xfs_btree_cur *, struct xfs_buf *, int);
 411 void xfs_btree_log_recs(struct xfs_btree_cur *, struct xfs_buf *, int, int);
 412
 413 /*
 414  * Helpers.
 415  */
 416 static inline int xfs_btree_get_numrecs(struct xfs_btree_block *block)
 417 {
 418         return be16_to_cpu(block->bb_numrecs);
 419 }
 420
 421 static 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
 427 static 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__ */