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_defer_ops;
  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 /*
  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  */
  45 union 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
  55 union 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
  79 __uint32_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
 108 struct 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 #if defined(DEBUG) || defined(XFS_WARN)
 167         /* check that k1 is lower than k2 */
 168         int     (*keys_inorder)(struct xfs_btree_cur *cur,
 169                                 union xfs_btree_key *k1,
 170                                 union xfs_btree_key *k2);
 171
 172         /* check that r1 is lower than r2 */
 173         int     (*recs_inorder)(struct xfs_btree_cur *cur,
 174                                 union xfs_btree_rec *r1,
 175                                 union xfs_btree_rec *r2);
 176 #endif
 177 };
 178
 179 /*
 180  * Reasons for the update_lastrec method to be called.
 181  */
 182 #define LASTREC_UPDATE  0
 183 #define LASTREC_INSREC  1
 184 #define LASTREC_DELREC  2
 185
 186
 187 union xfs_btree_irec {
 188         struct xfs_alloc_rec_incore     a;
 189         struct xfs_bmbt_irec            b;
 190         struct xfs_inobt_rec_incore     i;
 191         struct xfs_rmap_irec            r;
 192         struct xfs_refcount_irec        rc;
 193 };
 194
 195 /* Per-AG btree private information. */
 196 union xfs_btree_cur_private {
 197         struct {
 198                 unsigned long   nr_ops;         /* # record updates */
 199                 int             shape_changes;  /* # of extent splits */
 200         } refc;
 201 };
 202
 203 /*
 204  * Btree cursor structure.
 205  * This collects all information needed by the btree code in one place.
 206  */
 207 typedef struct xfs_btree_cur
 208 {
 209         struct xfs_trans        *bc_tp; /* transaction we're in, if any */
 210         struct xfs_mount        *bc_mp; /* file system mount struct */
 211         const struct xfs_btree_ops *bc_ops;
 212         uint                    bc_flags; /* btree features - below */
 213         union xfs_btree_irec    bc_rec; /* current insert/search record value */
 214         struct xfs_buf  *bc_bufs[XFS_BTREE_MAXLEVELS];  /* buf ptr per level */
 215         int             bc_ptrs[XFS_BTREE_MAXLEVELS];   /* key/record # */
 216         __uint8_t       bc_ra[XFS_BTREE_MAXLEVELS];     /* readahead bits */
 217 #define XFS_BTCUR_LEFTRA        1       /* left sibling has been read-ahead */
 218 #define XFS_BTCUR_RIGHTRA       2       /* right sibling has been read-ahead */
 219         __uint8_t       bc_nlevels;     /* number of levels in the tree */
 220         __uint8_t       bc_blocklog;    /* log2(blocksize) of btree blocks */
 221         xfs_btnum_t     bc_btnum;       /* identifies which btree type */
 222         int             bc_statoff;     /* offset of btre stats array */
 223         union {
 224                 struct {                        /* needed for BNO, CNT, INO */
 225                         struct xfs_buf  *agbp;  /* agf/agi buffer pointer */
 226                         struct xfs_defer_ops *dfops;    /* deferred updates */
 227                         xfs_agnumber_t  agno;   /* ag number */
 228                         union xfs_btree_cur_private     priv;
 229                 } a;
 230                 struct {                        /* needed for BMAP */
 231                         struct xfs_inode *ip;   /* pointer to our inode */
 232                         struct xfs_defer_ops *dfops;    /* deferred updates */
 233                         xfs_fsblock_t   firstblock;     /* 1st blk allocated */
 234                         int             allocated;      /* count of alloced */
 235                         short           forksize;       /* fork's inode space */
 236                         char            whichfork;      /* data or attr fork */
 237                         char            flags;          /* flags */
 238 #define XFS_BTCUR_BPRV_WASDEL   1                       /* was delayed */
 239                 } b;
 240         }               bc_private;     /* per-btree type data */
 241 } xfs_btree_cur_t;
 242
 243 /* cursor flags */
 244 #define XFS_BTREE_LONG_PTRS             (1<<0)  /* pointers are 64bits long */
 245 #define XFS_BTREE_ROOT_IN_INODE         (1<<1)  /* root may be variable size */
 246 #define XFS_BTREE_LASTREC_UPDATE        (1<<2)  /* track last rec externally */
 247 #define XFS_BTREE_CRC_BLOCKS            (1<<3)  /* uses extended btree blocks */
 248 #define XFS_BTREE_OVERLAPPING           (1<<4)  /* overlapping intervals */
 249
 250
 251 #define XFS_BTREE_NOERROR       0
 252 #define XFS_BTREE_ERROR         1
 253
 254 /*
 255  * Convert from buffer to btree block header.
 256  */
 257 #define XFS_BUF_TO_BLOCK(bp)    ((struct xfs_btree_block *)((bp)->b_addr))
 258
 259
 260 /*
 261  * Check that block header is ok.
 262  */
 263 int
 264 xfs_btree_check_block(
 265         struct xfs_btree_cur    *cur,   /* btree cursor */
 266         struct xfs_btree_block  *block, /* generic btree block pointer */
 267         int                     level,  /* level of the btree block */
 268         struct xfs_buf          *bp);   /* buffer containing block, if any */
 269
 270 /*
 271  * Check that (long) pointer is ok.
 272  */
 273 int                                     /* error (0 or EFSCORRUPTED) */
 274 xfs_btree_check_lptr(
 275         struct xfs_btree_cur    *cur,   /* btree cursor */
 276         xfs_fsblock_t           ptr,    /* btree block disk address */
 277         int                     level); /* btree block level */
 278
 279 /*
 280  * Delete the btree cursor.
 281  */
 282 void
 283 xfs_btree_del_cursor(
 284         xfs_btree_cur_t         *cur,   /* btree cursor */
 285         int                     error); /* del because of error */
 286
 287 /*
 288  * Duplicate the btree cursor.
 289  * Allocate a new one, copy the record, re-get the buffers.
 290  */
 291 int                                     /* error */
 292 xfs_btree_dup_cursor(
 293         xfs_btree_cur_t         *cur,   /* input cursor */
 294         xfs_btree_cur_t         **ncur);/* output cursor */
 295
 296 /*
 297  * Get a buffer for the block, return it with no data read.
 298  * Long-form addressing.
 299  */
 300 struct xfs_buf *                                /* buffer for fsbno */
 301 xfs_btree_get_bufl(
 302         struct xfs_mount        *mp,    /* file system mount point */
 303         struct xfs_trans        *tp,    /* transaction pointer */
 304         xfs_fsblock_t           fsbno,  /* file system block number */
 305         uint                    lock);  /* lock flags for get_buf */
 306
 307 /*
 308  * Get a buffer for the block, return it with no data read.
 309  * Short-form addressing.
 310  */
 311 struct xfs_buf *                                /* buffer for agno/agbno */
 312 xfs_btree_get_bufs(
 313         struct xfs_mount        *mp,    /* file system mount point */
 314         struct xfs_trans        *tp,    /* transaction pointer */
 315         xfs_agnumber_t          agno,   /* allocation group number */
 316         xfs_agblock_t           agbno,  /* allocation group block number */
 317         uint                    lock);  /* lock flags for get_buf */
 318
 319 /*
 320  * Check for the cursor referring to the last block at the given level.
 321  */
 322 int                                     /* 1=is last block, 0=not last block */
 323 xfs_btree_islastblock(
 324         xfs_btree_cur_t         *cur,   /* btree cursor */
 325         int                     level); /* level to check */
 326
 327 /*
 328  * Compute first and last byte offsets for the fields given.
 329  * Interprets the offsets table, which contains struct field offsets.
 330  */
 331 void
 332 xfs_btree_offsets(
 333         __int64_t               fields, /* bitmask of fields */
 334         const short             *offsets,/* table of field offsets */
 335         int                     nbits,  /* number of bits to inspect */
 336         int                     *first, /* output: first byte offset */
 337         int                     *last); /* output: last byte offset */
 338
 339 /*
 340  * Get a buffer for the block, return it read in.
 341  * Long-form addressing.
 342  */
 343 int                                     /* error */
 344 xfs_btree_read_bufl(
 345         struct xfs_mount        *mp,    /* file system mount point */
 346         struct xfs_trans        *tp,    /* transaction pointer */
 347         xfs_fsblock_t           fsbno,  /* file system block number */
 348         uint                    lock,   /* lock flags for read_buf */
 349         struct xfs_buf          **bpp,  /* buffer for fsbno */
 350         int                     refval, /* ref count value for buffer */
 351         const struct xfs_buf_ops *ops);
 352
 353 /*
 354  * Read-ahead the block, don't wait for it, don't return a buffer.
 355  * Long-form addressing.
 356  */
 357 void                                    /* error */
 358 xfs_btree_reada_bufl(
 359         struct xfs_mount        *mp,    /* file system mount point */
 360         xfs_fsblock_t           fsbno,  /* file system block number */
 361         xfs_extlen_t            count,  /* count of filesystem blocks */
 362         const struct xfs_buf_ops *ops);
 363
 364 /*
 365  * Read-ahead the block, don't wait for it, don't return a buffer.
 366  * Short-form addressing.
 367  */
 368 void                                    /* error */
 369 xfs_btree_reada_bufs(
 370         struct xfs_mount        *mp,    /* file system mount point */
 371         xfs_agnumber_t          agno,   /* allocation group number */
 372         xfs_agblock_t           agbno,  /* allocation group block number */
 373         xfs_extlen_t            count,  /* count of filesystem blocks */
 374         const struct xfs_buf_ops *ops);
 375
 376 /*
 377  * Initialise a new btree block header
 378  */
 379 void
 380 xfs_btree_init_block(
 381         struct xfs_mount *mp,
 382         struct xfs_buf  *bp,
 383         __u32           magic,
 384         __u16           level,
 385         __u16           numrecs,
 386         __u64           owner,
 387         unsigned int    flags);
 388
 389 void
 390 xfs_btree_init_block_int(
 391         struct xfs_mount        *mp,
 392         struct xfs_btree_block  *buf,
 393         xfs_daddr_t             blkno,
 394         __u32                   magic,
 395         __u16                   level,
 396         __u16                   numrecs,
 397         __u64                   owner,
 398         unsigned int            flags);
 399
 400 /*
 401  * Common btree core entry points.
 402  */
 403 int xfs_btree_increment(struct xfs_btree_cur *, int, int *);
 404 int xfs_btree_decrement(struct xfs_btree_cur *, int, int *);
 405 int xfs_btree_lookup(struct xfs_btree_cur *, xfs_lookup_t, int *);
 406 int xfs_btree_update(struct xfs_btree_cur *, union xfs_btree_rec *);
 407 int xfs_btree_new_iroot(struct xfs_btree_cur *, int *, int *);
 408 int xfs_btree_insert(struct xfs_btree_cur *, int *);
 409 int xfs_btree_delete(struct xfs_btree_cur *, int *);
 410 int xfs_btree_get_rec(struct xfs_btree_cur *, union xfs_btree_rec **, int *);
 411 int xfs_btree_change_owner(struct xfs_btree_cur *cur, __uint64_t new_owner,
 412                            struct list_head *buffer_list);
 413
 414 /*
 415  * btree block CRC helpers
 416  */
 417 void xfs_btree_lblock_calc_crc(struct xfs_buf *);
 418 bool xfs_btree_lblock_verify_crc(struct xfs_buf *);
 419 void xfs_btree_sblock_calc_crc(struct xfs_buf *);
 420 bool xfs_btree_sblock_verify_crc(struct xfs_buf *);
 421
 422 /*
 423  * Internal btree helpers also used by xfs_bmap.c.
 424  */
 425 void xfs_btree_log_block(struct xfs_btree_cur *, struct xfs_buf *, int);
 426 void xfs_btree_log_recs(struct xfs_btree_cur *, struct xfs_buf *, int, int);
 427
 428 /*
 429  * Helpers.
 430  */
 431 static inline int xfs_btree_get_numrecs(struct xfs_btree_block *block)
 432 {
 433         return be16_to_cpu(block->bb_numrecs);
 434 }
 435
 436 static inline void xfs_btree_set_numrecs(struct xfs_btree_block *block,
 437                 __uint16_t numrecs)
 438 {
 439         block->bb_numrecs = cpu_to_be16(numrecs);
 440 }
 441
 442 static inline int xfs_btree_get_level(struct xfs_btree_block *block)
 443 {
 444         return be16_to_cpu(block->bb_level);
 445 }
 446
 447
 448 /*
 449  * Min and max functions for extlen, agblock, fileoff, and filblks types.
 450  */
 451 #define XFS_EXTLEN_MIN(a,b)     min_t(xfs_extlen_t, (a), (b))
 452 #define XFS_EXTLEN_MAX(a,b)     max_t(xfs_extlen_t, (a), (b))
 453 #define XFS_AGBLOCK_MIN(a,b)    min_t(xfs_agblock_t, (a), (b))
 454 #define XFS_AGBLOCK_MAX(a,b)    max_t(xfs_agblock_t, (a), (b))
 455 #define XFS_FILEOFF_MIN(a,b)    min_t(xfs_fileoff_t, (a), (b))
 456 #define XFS_FILEOFF_MAX(a,b)    max_t(xfs_fileoff_t, (a), (b))
 457 #define XFS_FILBLKS_MIN(a,b)    min_t(xfs_filblks_t, (a), (b))
 458 #define XFS_FILBLKS_MAX(a,b)    max_t(xfs_filblks_t, (a), (b))
 459
 460 #define XFS_FSB_SANITY_CHECK(mp,fsb)    \
 461         (XFS_FSB_TO_AGNO(mp, fsb) < mp->m_sb.sb_agcount && \
 462                 XFS_FSB_TO_AGBNO(mp, fsb) < mp->m_sb.sb_agblocks)
 463
 464 /*
 465  * Trace hooks.  Currently not implemented as they need to be ported
 466  * over to the generic tracing functionality, which is some effort.
 467  *
 468  * i,j = integer (32 bit)
 469  * b = btree block buffer (xfs_buf_t)
 470  * p = btree ptr
 471  * r = btree record
 472  * k = btree key
 473  */
 474 #define XFS_BTREE_TRACE_ARGBI(c, b, i)
 475 #define XFS_BTREE_TRACE_ARGBII(c, b, i, j)
 476 #define XFS_BTREE_TRACE_ARGI(c, i)
 477 #define XFS_BTREE_TRACE_ARGIPK(c, i, p, s)
 478 #define XFS_BTREE_TRACE_ARGIPR(c, i, p, r)
 479 #define XFS_BTREE_TRACE_ARGIK(c, i, k)
 480 #define XFS_BTREE_TRACE_ARGR(c, r)
 481 #define XFS_BTREE_TRACE_CURSOR(c, t)
 482
 483 bool xfs_btree_sblock_v5hdr_verify(struct xfs_buf *bp);
 484 bool xfs_btree_sblock_verify(struct xfs_buf *bp, unsigned int max_recs);
 485 uint xfs_btree_compute_maxlevels(struct xfs_mount *mp, uint *limits,
 486                                  unsigned long len);
 487 xfs_extlen_t xfs_btree_calc_size(struct xfs_mount *mp, uint *limits,
 488                 unsigned long long len);
 489
 490 /* return codes */
 491 #define XFS_BTREE_QUERY_RANGE_CONTINUE  0       /* keep iterating */
 492 #define XFS_BTREE_QUERY_RANGE_ABORT     1       /* stop iterating */
 493 typedef int (*xfs_btree_query_range_fn)(struct xfs_btree_cur *cur,
 494                 union xfs_btree_rec *rec, void *priv);
 495
 496 int xfs_btree_query_range(struct xfs_btree_cur *cur,
 497                 union xfs_btree_irec *low_rec, union xfs_btree_irec *high_rec,
 498                 xfs_btree_query_range_fn fn, void *priv);
 499
 500 typedef int (*xfs_btree_visit_blocks_fn)(struct xfs_btree_cur *cur, int level,
 501                 void *data);
 502 int xfs_btree_visit_blocks(struct xfs_btree_cur *cur,
 503                 xfs_btree_visit_blocks_fn fn, void *data);
 504
 505 int xfs_btree_count_blocks(struct xfs_btree_cur *cur, xfs_extlen_t *blocks);
 506
 507 #endif  /* __XFS_BTREE_H__ */