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  * This nonsense is to make -wlint happy.
  31  */
  32 #define XFS_LOOKUP_EQ   ((xfs_lookup_t)XFS_LOOKUP_EQi)
  33 #define XFS_LOOKUP_LE   ((xfs_lookup_t)XFS_LOOKUP_LEi)
  34 #define XFS_LOOKUP_GE   ((xfs_lookup_t)XFS_LOOKUP_GEi)
  35
  36 #define XFS_BTNUM_BNO   ((xfs_btnum_t)XFS_BTNUM_BNOi)
  37 #define XFS_BTNUM_CNT   ((xfs_btnum_t)XFS_BTNUM_CNTi)
  38 #define XFS_BTNUM_BMAP  ((xfs_btnum_t)XFS_BTNUM_BMAPi)
  39 #define XFS_BTNUM_INO   ((xfs_btnum_t)XFS_BTNUM_INOi)
  40
  41 /*
  42  * Generic btree header.
  43  *
  44  * This is a combination of the actual format used on disk for short and long
  45  * format btrees.  The first three fields are shared by both format, but the
  46  * pointers are different and should be used with care.
  47  *
  48  * To get the size of the actual short or long form headers please use the size
  49  * macros below.  Never use sizeof(xfs_btree_block).
  50  *
  51  * The blkno, crc, lsn, owner and uuid fields are only available in filesystems
  52  * with the crc feature bit, and all accesses to them must be conditional on
  53  * that flag.
  54  */
  55 struct xfs_btree_block {
  56         __be32          bb_magic;       /* magic number for block type */
  57         __be16          bb_level;       /* 0 is a leaf */
  58         __be16          bb_numrecs;     /* current # of data records */
  59         union {
  60                 struct {
  61                         __be32          bb_leftsib;
  62                         __be32          bb_rightsib;
  63
  64                         __be64          bb_blkno;
  65                         __be64          bb_lsn;
  66                         uuid_t          bb_uuid;
  67                         __be32          bb_owner;
  68                         __le32          bb_crc;
  69                 } s;                    /* short form pointers */
  70                 struct  {
  71                         __be64          bb_leftsib;
  72                         __be64          bb_rightsib;
  73
  74                         __be64          bb_blkno;
  75                         __be64          bb_lsn;
  76                         uuid_t          bb_uuid;
  77                         __be64          bb_owner;
  78                         __le32          bb_crc;
  79                         __be32          bb_pad; /* padding for alignment */
  80                 } l;                    /* long form pointers */
  81         } bb_u;                         /* rest */
  82 };
  83
  84 #define XFS_BTREE_SBLOCK_LEN    16      /* size of a short form block */
  85 #define XFS_BTREE_LBLOCK_LEN    24      /* size of a long form block */
  86
  87 /* sizes of CRC enabled btree blocks */
  88 #define XFS_BTREE_SBLOCK_CRC_LEN        (XFS_BTREE_SBLOCK_LEN + 40)
  89 #define XFS_BTREE_LBLOCK_CRC_LEN        (XFS_BTREE_LBLOCK_LEN + 48)
  90
  91 #define XFS_BTREE_SBLOCK_CRC_OFF \
  92         offsetof(struct xfs_btree_block, bb_u.s.bb_crc)
  93 #define XFS_BTREE_LBLOCK_CRC_OFF \
  94         offsetof(struct xfs_btree_block, bb_u.l.bb_crc)
  95
  96 /*
  97  * Generic key, ptr and record wrapper structures.
  98  *
  99  * These are disk format structures, and are converted where necessary
 100  * by the btree specific code that needs to interpret them.
 101  */
 102 union xfs_btree_ptr {
 103         __be32                  s;      /* short form ptr */
 104         __be64                  l;      /* long form ptr */
 105 };
 106
 107 union xfs_btree_key {
 108         xfs_bmbt_key_t          bmbt;
 109         xfs_bmdr_key_t          bmbr;   /* bmbt root block */
 110         xfs_alloc_key_t         alloc;
 111         xfs_inobt_key_t         inobt;
 112 };
 113
 114 union xfs_btree_rec {
 115         xfs_bmbt_rec_t          bmbt;
 116         xfs_bmdr_rec_t          bmbr;   /* bmbt root block */
 117         xfs_alloc_rec_t         alloc;
 118         xfs_inobt_rec_t         inobt;
 119 };
 120
 121 /*
 122  * For logging record fields.
 123  */
 124 #define XFS_BB_MAGIC            (1 << 0)
 125 #define XFS_BB_LEVEL            (1 << 1)
 126 #define XFS_BB_NUMRECS          (1 << 2)
 127 #define XFS_BB_LEFTSIB          (1 << 3)
 128 #define XFS_BB_RIGHTSIB         (1 << 4)
 129 #define XFS_BB_BLKNO            (1 << 5)
 130 #define XFS_BB_LSN              (1 << 6)
 131 #define XFS_BB_UUID             (1 << 7)
 132 #define XFS_BB_OWNER            (1 << 8)
 133 #define XFS_BB_NUM_BITS         5
 134 #define XFS_BB_ALL_BITS         ((1 << XFS_BB_NUM_BITS) - 1)
 135 #define XFS_BB_NUM_BITS_CRC     9
 136 #define XFS_BB_ALL_BITS_CRC     ((1 << XFS_BB_NUM_BITS_CRC) - 1)
 137
 138 /*
 139  * Generic stats interface
 140  */
 141 #define __XFS_BTREE_STATS_INC(type, stat) \
 142         XFS_STATS_INC(xs_ ## type ## _2_ ## stat)
 143 #define XFS_BTREE_STATS_INC(cur, stat)  \
 144 do {    \
 145         switch (cur->bc_btnum) {  \
 146         case XFS_BTNUM_BNO: __XFS_BTREE_STATS_INC(abtb, stat); break;   \
 147         case XFS_BTNUM_CNT: __XFS_BTREE_STATS_INC(abtc, stat); break;   \
 148         case XFS_BTNUM_BMAP: __XFS_BTREE_STATS_INC(bmbt, stat); break;  \
 149         case XFS_BTNUM_INO: __XFS_BTREE_STATS_INC(ibt, stat); break;    \
 150         case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break;       \
 151         }       \
 152 } while (0)
 153
 154 #define __XFS_BTREE_STATS_ADD(type, stat, val) \
 155         XFS_STATS_ADD(xs_ ## type ## _2_ ## stat, val)
 156 #define XFS_BTREE_STATS_ADD(cur, stat, val)  \
 157 do {    \
 158         switch (cur->bc_btnum) {  \
 159         case XFS_BTNUM_BNO: __XFS_BTREE_STATS_ADD(abtb, stat, val); break; \
 160         case XFS_BTNUM_CNT: __XFS_BTREE_STATS_ADD(abtc, stat, val); break; \
 161         case XFS_BTNUM_BMAP: __XFS_BTREE_STATS_ADD(bmbt, stat, val); break; \
 162         case XFS_BTNUM_INO: __XFS_BTREE_STATS_ADD(ibt, stat, val); break; \
 163         case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break;       \
 164         }       \
 165 } while (0)
 166
 167 #define XFS_BTREE_MAXLEVELS     8       /* max of all btrees */
 168
 169 struct xfs_btree_ops {
 170         /* size of the key and record structures */
 171         size_t  key_len;
 172         size_t  rec_len;
 173
 174         /* cursor operations */
 175         struct xfs_btree_cur *(*dup_cursor)(struct xfs_btree_cur *);
 176         void    (*update_cursor)(struct xfs_btree_cur *src,
 177                                  struct xfs_btree_cur *dst);
 178
 179         /* update btree root pointer */
 180         void    (*set_root)(struct xfs_btree_cur *cur,
 181                             union xfs_btree_ptr *nptr, int level_change);
 182
 183         /* block allocation / freeing */
 184         int     (*alloc_block)(struct xfs_btree_cur *cur,
 185                                union xfs_btree_ptr *start_bno,
 186                                union xfs_btree_ptr *new_bno,
 187                                int length, int *stat);
 188         int     (*free_block)(struct xfs_btree_cur *cur, struct xfs_buf *bp);
 189
 190         /* update last record information */
 191         void    (*update_lastrec)(struct xfs_btree_cur *cur,
 192                                   struct xfs_btree_block *block,
 193                                   union xfs_btree_rec *rec,
 194                                   int ptr, int reason);
 195
 196         /* records in block/level */
 197         int     (*get_minrecs)(struct xfs_btree_cur *cur, int level);
 198         int     (*get_maxrecs)(struct xfs_btree_cur *cur, int level);
 199
 200         /* records on disk.  Matter for the root in inode case. */
 201         int     (*get_dmaxrecs)(struct xfs_btree_cur *cur, int level);
 202
 203         /* init values of btree structures */
 204         void    (*init_key_from_rec)(union xfs_btree_key *key,
 205                                      union xfs_btree_rec *rec);
 206         void    (*init_rec_from_key)(union xfs_btree_key *key,
 207                                      union xfs_btree_rec *rec);
 208         void    (*init_rec_from_cur)(struct xfs_btree_cur *cur,
 209                                      union xfs_btree_rec *rec);
 210         void    (*init_ptr_from_cur)(struct xfs_btree_cur *cur,
 211                                      union xfs_btree_ptr *ptr);
 212
 213         /* difference between key value and cursor value */
 214         __int64_t (*key_diff)(struct xfs_btree_cur *cur,
 215                               union xfs_btree_key *key);
 216
 217         const struct xfs_buf_ops        *buf_ops;
 218
 219 #if defined(DEBUG) || defined(XFS_WARN)
 220         /* check that k1 is lower than k2 */
 221         int     (*keys_inorder)(struct xfs_btree_cur *cur,
 222                                 union xfs_btree_key *k1,
 223                                 union xfs_btree_key *k2);
 224
 225         /* check that r1 is lower than r2 */
 226         int     (*recs_inorder)(struct xfs_btree_cur *cur,
 227                                 union xfs_btree_rec *r1,
 228                                 union xfs_btree_rec *r2);
 229 #endif
 230 };
 231
 232 /*
 233  * Reasons for the update_lastrec method to be called.
 234  */
 235 #define LASTREC_UPDATE  0
 236 #define LASTREC_INSREC  1
 237 #define LASTREC_DELREC  2
 238
 239
 240 /*
 241  * Btree cursor structure.
 242  * This collects all information needed by the btree code in one place.
 243  */
 244 typedef struct xfs_btree_cur
 245 {
 246         struct xfs_trans        *bc_tp; /* transaction we're in, if any */
 247         struct xfs_mount        *bc_mp; /* file system mount struct */
 248         const struct xfs_btree_ops *bc_ops;
 249         uint                    bc_flags; /* btree features - below */
 250         union {
 251                 xfs_alloc_rec_incore_t  a;
 252                 xfs_bmbt_irec_t         b;
 253                 xfs_inobt_rec_incore_t  i;
 254         }               bc_rec;         /* current insert/search record value */
 255         struct xfs_buf  *bc_bufs[XFS_BTREE_MAXLEVELS];  /* buf ptr per level */
 256         int             bc_ptrs[XFS_BTREE_MAXLEVELS];   /* key/record # */
 257         __uint8_t       bc_ra[XFS_BTREE_MAXLEVELS];     /* readahead bits */
 258 #define XFS_BTCUR_LEFTRA        1       /* left sibling has been read-ahead */
 259 #define XFS_BTCUR_RIGHTRA       2       /* right sibling has been read-ahead */
 260         __uint8_t       bc_nlevels;     /* number of levels in the tree */
 261         __uint8_t       bc_blocklog;    /* log2(blocksize) of btree blocks */
 262         xfs_btnum_t     bc_btnum;       /* identifies which btree type */
 263         union {
 264                 struct {                        /* needed for BNO, CNT, INO */
 265                         struct xfs_buf  *agbp;  /* agf/agi buffer pointer */
 266                         xfs_agnumber_t  agno;   /* ag number */
 267                 } a;
 268                 struct {                        /* needed for BMAP */
 269                         struct xfs_inode *ip;   /* pointer to our inode */
 270                         struct xfs_bmap_free *flist;    /* list to free after */
 271                         xfs_fsblock_t   firstblock;     /* 1st blk allocated */
 272                         int             allocated;      /* count of alloced */
 273                         short           forksize;       /* fork's inode space */
 274                         char            whichfork;      /* data or attr fork */
 275                         char            flags;          /* flags */
 276 #define XFS_BTCUR_BPRV_WASDEL   1                       /* was delayed */
 277                 } b;
 278         }               bc_private;     /* per-btree type data */
 279 } xfs_btree_cur_t;
 280
 281 /* cursor flags */
 282 #define XFS_BTREE_LONG_PTRS             (1<<0)  /* pointers are 64bits long */
 283 #define XFS_BTREE_ROOT_IN_INODE         (1<<1)  /* root may be variable size */
 284 #define XFS_BTREE_LASTREC_UPDATE        (1<<2)  /* track last rec externally */
 285 #define XFS_BTREE_CRC_BLOCKS            (1<<3)  /* uses extended btree blocks */
 286
 287
 288 #define XFS_BTREE_NOERROR       0
 289 #define XFS_BTREE_ERROR         1
 290
 291 /*
 292  * Convert from buffer to btree block header.
 293  */
 294 #define XFS_BUF_TO_BLOCK(bp)    ((struct xfs_btree_block *)((bp)->b_addr))
 295
 296
 297 /*
 298  * Check that block header is ok.
 299  */
 300 int
 301 xfs_btree_check_block(
 302         struct xfs_btree_cur    *cur,   /* btree cursor */
 303         struct xfs_btree_block  *block, /* generic btree block pointer */
 304         int                     level,  /* level of the btree block */
 305         struct xfs_buf          *bp);   /* buffer containing block, if any */
 306
 307 /*
 308  * Check that (long) pointer is ok.
 309  */
 310 int                                     /* error (0 or EFSCORRUPTED) */
 311 xfs_btree_check_lptr(
 312         struct xfs_btree_cur    *cur,   /* btree cursor */
 313         xfs_dfsbno_t            ptr,    /* btree block disk address */
 314         int                     level); /* btree block level */
 315
 316 /*
 317  * Delete the btree cursor.
 318  */
 319 void
 320 xfs_btree_del_cursor(
 321         xfs_btree_cur_t         *cur,   /* btree cursor */
 322         int                     error); /* del because of error */
 323
 324 /*
 325  * Duplicate the btree cursor.
 326  * Allocate a new one, copy the record, re-get the buffers.
 327  */
 328 int                                     /* error */
 329 xfs_btree_dup_cursor(
 330         xfs_btree_cur_t         *cur,   /* input cursor */
 331         xfs_btree_cur_t         **ncur);/* output cursor */
 332
 333 /*
 334  * Get a buffer for the block, return it with no data read.
 335  * Long-form addressing.
 336  */
 337 struct xfs_buf *                                /* buffer for fsbno */
 338 xfs_btree_get_bufl(
 339         struct xfs_mount        *mp,    /* file system mount point */
 340         struct xfs_trans        *tp,    /* transaction pointer */
 341         xfs_fsblock_t           fsbno,  /* file system block number */
 342         uint                    lock);  /* lock flags for get_buf */
 343
 344 /*
 345  * Get a buffer for the block, return it with no data read.
 346  * Short-form addressing.
 347  */
 348 struct xfs_buf *                                /* buffer for agno/agbno */
 349 xfs_btree_get_bufs(
 350         struct xfs_mount        *mp,    /* file system mount point */
 351         struct xfs_trans        *tp,    /* transaction pointer */
 352         xfs_agnumber_t          agno,   /* allocation group number */
 353         xfs_agblock_t           agbno,  /* allocation group block number */
 354         uint                    lock);  /* lock flags for get_buf */
 355
 356 /*
 357  * Check for the cursor referring to the last block at the given level.
 358  */
 359 int                                     /* 1=is last block, 0=not last block */
 360 xfs_btree_islastblock(
 361         xfs_btree_cur_t         *cur,   /* btree cursor */
 362         int                     level); /* level to check */
 363
 364 /*
 365  * Compute first and last byte offsets for the fields given.
 366  * Interprets the offsets table, which contains struct field offsets.
 367  */
 368 void
 369 xfs_btree_offsets(
 370         __int64_t               fields, /* bitmask of fields */
 371         const short             *offsets,/* table of field offsets */
 372         int                     nbits,  /* number of bits to inspect */
 373         int                     *first, /* output: first byte offset */
 374         int                     *last); /* output: last byte offset */
 375
 376 /*
 377  * Get a buffer for the block, return it read in.
 378  * Long-form addressing.
 379  */
 380 int                                     /* error */
 381 xfs_btree_read_bufl(
 382         struct xfs_mount        *mp,    /* file system mount point */
 383         struct xfs_trans        *tp,    /* transaction pointer */
 384         xfs_fsblock_t           fsbno,  /* file system block number */
 385         uint                    lock,   /* lock flags for read_buf */
 386         struct xfs_buf          **bpp,  /* buffer for fsbno */
 387         int                     refval, /* ref count value for buffer */
 388         const struct xfs_buf_ops *ops);
 389
 390 /*
 391  * Read-ahead the block, don't wait for it, don't return a buffer.
 392  * Long-form addressing.
 393  */
 394 void                                    /* error */
 395 xfs_btree_reada_bufl(
 396         struct xfs_mount        *mp,    /* file system mount point */
 397         xfs_fsblock_t           fsbno,  /* file system block number */
 398         xfs_extlen_t            count,  /* count of filesystem blocks */
 399         const struct xfs_buf_ops *ops);
 400
 401 /*
 402  * Read-ahead the block, don't wait for it, don't return a buffer.
 403  * Short-form addressing.
 404  */
 405 void                                    /* error */
 406 xfs_btree_reada_bufs(
 407         struct xfs_mount        *mp,    /* file system mount point */
 408         xfs_agnumber_t          agno,   /* allocation group number */
 409         xfs_agblock_t           agbno,  /* allocation group block number */
 410         xfs_extlen_t            count,  /* count of filesystem blocks */
 411         const struct xfs_buf_ops *ops);
 412
 413 /*
 414  * Initialise a new btree block header
 415  */
 416 void
 417 xfs_btree_init_block(
 418         struct xfs_mount *mp,
 419         struct xfs_buf  *bp,
 420         __u32           magic,
 421         __u16           level,
 422         __u16           numrecs,
 423         __u64           owner,
 424         unsigned int    flags);
 425
 426 void
 427 xfs_btree_init_block_int(
 428         struct xfs_mount        *mp,
 429         struct xfs_btree_block  *buf,
 430         xfs_daddr_t             blkno,
 431         __u32                   magic,
 432         __u16                   level,
 433         __u16                   numrecs,
 434         __u64                   owner,
 435         unsigned int            flags);
 436
 437 /*
 438  * Common btree core entry points.
 439  */
 440 int xfs_btree_increment(struct xfs_btree_cur *, int, int *);
 441 int xfs_btree_decrement(struct xfs_btree_cur *, int, int *);
 442 int xfs_btree_lookup(struct xfs_btree_cur *, xfs_lookup_t, int *);
 443 int xfs_btree_update(struct xfs_btree_cur *, union xfs_btree_rec *);
 444 int xfs_btree_new_iroot(struct xfs_btree_cur *, int *, int *);
 445 int xfs_btree_insert(struct xfs_btree_cur *, int *);
 446 int xfs_btree_delete(struct xfs_btree_cur *, int *);
 447 int xfs_btree_get_rec(struct xfs_btree_cur *, union xfs_btree_rec **, int *);
 448 int xfs_btree_change_owner(struct xfs_btree_cur *cur, __uint64_t new_owner,
 449                            struct list_head *buffer_list);
 450
 451 /*
 452  * btree block CRC helpers
 453  */
 454 void xfs_btree_lblock_calc_crc(struct xfs_buf *);
 455 bool xfs_btree_lblock_verify_crc(struct xfs_buf *);
 456 void xfs_btree_sblock_calc_crc(struct xfs_buf *);
 457 bool xfs_btree_sblock_verify_crc(struct xfs_buf *);
 458
 459 /*
 460  * Internal btree helpers also used by xfs_bmap.c.
 461  */
 462 void xfs_btree_log_block(struct xfs_btree_cur *, struct xfs_buf *, int);
 463 void xfs_btree_log_recs(struct xfs_btree_cur *, struct xfs_buf *, int, int);
 464
 465 /*
 466  * Helpers.
 467  */
 468 static inline int xfs_btree_get_numrecs(struct xfs_btree_block *block)
 469 {
 470         return be16_to_cpu(block->bb_numrecs);
 471 }
 472
 473 static inline void xfs_btree_set_numrecs(struct xfs_btree_block *block,
 474                 __uint16_t numrecs)
 475 {
 476         block->bb_numrecs = cpu_to_be16(numrecs);
 477 }
 478
 479 static inline int xfs_btree_get_level(struct xfs_btree_block *block)
 480 {
 481         return be16_to_cpu(block->bb_level);
 482 }
 483
 484
 485 /*
 486  * Min and max functions for extlen, agblock, fileoff, and filblks types.
 487  */
 488 #define XFS_EXTLEN_MIN(a,b)     min_t(xfs_extlen_t, (a), (b))
 489 #define XFS_EXTLEN_MAX(a,b)     max_t(xfs_extlen_t, (a), (b))
 490 #define XFS_AGBLOCK_MIN(a,b)    min_t(xfs_agblock_t, (a), (b))
 491 #define XFS_AGBLOCK_MAX(a,b)    max_t(xfs_agblock_t, (a), (b))
 492 #define XFS_FILEOFF_MIN(a,b)    min_t(xfs_fileoff_t, (a), (b))
 493 #define XFS_FILEOFF_MAX(a,b)    max_t(xfs_fileoff_t, (a), (b))
 494 #define XFS_FILBLKS_MIN(a,b)    min_t(xfs_filblks_t, (a), (b))
 495 #define XFS_FILBLKS_MAX(a,b)    max_t(xfs_filblks_t, (a), (b))
 496
 497 #define XFS_FSB_SANITY_CHECK(mp,fsb)    \
 498         (XFS_FSB_TO_AGNO(mp, fsb) < mp->m_sb.sb_agcount && \
 499                 XFS_FSB_TO_AGBNO(mp, fsb) < mp->m_sb.sb_agblocks)
 500
 501 /*
 502  * Trace hooks.  Currently not implemented as they need to be ported
 503  * over to the generic tracing functionality, which is some effort.
 504  *
 505  * i,j = integer (32 bit)
 506  * b = btree block buffer (xfs_buf_t)
 507  * p = btree ptr
 508  * r = btree record
 509  * k = btree key
 510  */
 511 #define XFS_BTREE_TRACE_ARGBI(c, b, i)
 512 #define XFS_BTREE_TRACE_ARGBII(c, b, i, j)
 513 #define XFS_BTREE_TRACE_ARGI(c, i)
 514 #define XFS_BTREE_TRACE_ARGIPK(c, i, p, s)
 515 #define XFS_BTREE_TRACE_ARGIPR(c, i, p, r)
 516 #define XFS_BTREE_TRACE_ARGIK(c, i, k)
 517 #define XFS_BTREE_TRACE_ARGR(c, r)
 518 #define XFS_BTREE_TRACE_CURSOR(c, t)
 519
 520 #endif  /* __XFS_BTREE_H__ */