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 comination of the actual format used on disk for short and long
45 * format btrees. The first three fields are shared by both format, but
46 * the 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
49 * the size macros below. Never use sizeof(xfs_btree_block).
50 */
51 struct xfs_btree_block {
52 __be32 bb_magic; /* magic number for block type */
53 __be16 bb_level; /* 0 is a leaf */
54 __be16 bb_numrecs; /* current # of data records */
55 union {
56 struct {
57 __be32 bb_leftsib;
58 __be32 bb_rightsib;
59 } s; /* short form pointers */
60 struct {
61 __be64 bb_leftsib;
62 __be64 bb_rightsib;
63 } l; /* long form pointers */
64 } bb_u; /* rest */
65 };
66
67 #define XFS_BTREE_SBLOCK_LEN 16 /* size of a short form block */
68 #define XFS_BTREE_LBLOCK_LEN 24 /* size of a long form block */
69
70
71 /*
72 * Generic key, ptr and record wrapper structures.
73 *
74 * These are disk format structures, and are converted where necessary
75 * by the btree specific code that needs to interpret them.
76 */
77 union xfs_btree_ptr {
78 __be32 s; /* short form ptr */
79 __be64 l; /* long form ptr */
80 };
81
82 union xfs_btree_key {
83 xfs_bmbt_key_t bmbt;
84 xfs_bmdr_key_t bmbr; /* bmbt root block */
85 xfs_alloc_key_t alloc;
86 xfs_inobt_key_t inobt;
87 };
88
89 union xfs_btree_rec {
90 xfs_bmbt_rec_t bmbt;
91 xfs_bmdr_rec_t bmbr; /* bmbt root block */
92 xfs_alloc_rec_t alloc;
93 xfs_inobt_rec_t inobt;
94 };
95
96 /*
97 * For logging record fields.
98 */
99 #define XFS_BB_MAGIC 0x01
100 #define XFS_BB_LEVEL 0x02
101 #define XFS_BB_NUMRECS 0x04
102 #define XFS_BB_LEFTSIB 0x08
103 #define XFS_BB_RIGHTSIB 0x10
104 #define XFS_BB_NUM_BITS 5
105 #define XFS_BB_ALL_BITS ((1 << XFS_BB_NUM_BITS) - 1)
106
107 /*
108 * Magic numbers for btree blocks.
109 */
110 extern const __uint32_t xfs_magics[];
111
112 /*
113 * Generic stats interface
114 */
115 #define __XFS_BTREE_STATS_INC(type, stat) \
116 XFS_STATS_INC(xs_ ## type ## _2_ ## stat)
117 #define XFS_BTREE_STATS_INC(cur, stat) \
118 do { \
119 switch (cur->bc_btnum) { \
120 case XFS_BTNUM_BNO: __XFS_BTREE_STATS_INC(abtb, stat); break; \
121 case XFS_BTNUM_CNT: __XFS_BTREE_STATS_INC(abtc, stat); break; \
122 case XFS_BTNUM_BMAP: __XFS_BTREE_STATS_INC(bmbt, stat); break; \
123 case XFS_BTNUM_INO: __XFS_BTREE_STATS_INC(ibt, stat); break; \
124 case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break; \
125 } \
126 } while (0)
127
128 #define __XFS_BTREE_STATS_ADD(type, stat, val) \
129 XFS_STATS_ADD(xs_ ## type ## _2_ ## stat, val)
130 #define XFS_BTREE_STATS_ADD(cur, stat, val) \
131 do { \
132 switch (cur->bc_btnum) { \
133 case XFS_BTNUM_BNO: __XFS_BTREE_STATS_ADD(abtb, stat, val); break; \
134 case XFS_BTNUM_CNT: __XFS_BTREE_STATS_ADD(abtc, stat, val); break; \
135 case XFS_BTNUM_BMAP: __XFS_BTREE_STATS_ADD(bmbt, stat, val); break; \
136 case XFS_BTNUM_INO: __XFS_BTREE_STATS_ADD(ibt, stat, val); break; \
137 case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break; \
138 } \
139 } while (0)
140
141 #define XFS_BTREE_MAXLEVELS 8 /* max of all btrees */
142
143 struct xfs_btree_ops {
144 /* size of the key and record structures */
145 size_t key_len;
146 size_t rec_len;
147
148 /* cursor operations */
149 struct xfs_btree_cur *(*dup_cursor)(struct xfs_btree_cur *);
150 void (*update_cursor)(struct xfs_btree_cur *src,
151 struct xfs_btree_cur *dst);
152
153 /* update btree root pointer */
154 void (*set_root)(struct xfs_btree_cur *cur,
155 union xfs_btree_ptr *nptr, int level_change);
156 int (*kill_root)(struct xfs_btree_cur *cur, struct xfs_buf *bp,
157 int level, union xfs_btree_ptr *newroot);
158
159 /* block allocation / freeing */
160 int (*alloc_block)(struct xfs_btree_cur *cur,
161 union xfs_btree_ptr *start_bno,
162 union xfs_btree_ptr *new_bno,
163 int length, int *stat);
164 int (*free_block)(struct xfs_btree_cur *cur, struct xfs_buf *bp);
165
166 /* update last record information */
167 void (*update_lastrec)(struct xfs_btree_cur *cur,
168 struct xfs_btree_block *block,
169 union xfs_btree_rec *rec,
170 int ptr, int reason);
171
172 /* records in block/level */
173 int (*get_minrecs)(struct xfs_btree_cur *cur, int level);
174 int (*get_maxrecs)(struct xfs_btree_cur *cur, int level);
175
176 /* records on disk. Matter for the root in inode case. */
177 int (*get_dmaxrecs)(struct xfs_btree_cur *cur, int level);
178
179 /* init values of btree structures */
180 void (*init_key_from_rec)(union xfs_btree_key *key,
181 union xfs_btree_rec *rec);
182 void (*init_rec_from_key)(union xfs_btree_key *key,
183 union xfs_btree_rec *rec);
184 void (*init_rec_from_cur)(struct xfs_btree_cur *cur,
185 union xfs_btree_rec *rec);
186 void (*init_ptr_from_cur)(struct xfs_btree_cur *cur,
187 union xfs_btree_ptr *ptr);
188
189 /* difference between key value and cursor value */
190 __int64_t (*key_diff)(struct xfs_btree_cur *cur,
191 union xfs_btree_key *key);
192
193 #ifdef DEBUG
194 /* check that k1 is lower than k2 */
195 int (*keys_inorder)(struct xfs_btree_cur *cur,
196 union xfs_btree_key *k1,
197 union xfs_btree_key *k2);
198
199 /* check that r1 is lower than r2 */
200 int (*recs_inorder)(struct xfs_btree_cur *cur,
201 union xfs_btree_rec *r1,
202 union xfs_btree_rec *r2);
203 #endif
204
205 /* btree tracing */
206 #ifdef XFS_BTREE_TRACE
207 void (*trace_enter)(struct xfs_btree_cur *, const char *,
208 char *, int, int, __psunsigned_t,
209 __psunsigned_t, __psunsigned_t,
210 __psunsigned_t, __psunsigned_t,
211 __psunsigned_t, __psunsigned_t,
212 __psunsigned_t, __psunsigned_t,
213 __psunsigned_t, __psunsigned_t);
214 void (*trace_cursor)(struct xfs_btree_cur *, __uint32_t *,
215 __uint64_t *, __uint64_t *);
216 void (*trace_key)(struct xfs_btree_cur *,
217 union xfs_btree_key *, __uint64_t *,
218 __uint64_t *);
219 void (*trace_record)(struct xfs_btree_cur *,
220 union xfs_btree_rec *, __uint64_t *,
221 __uint64_t *, __uint64_t *);
222 #endif
223 };
224
225 /*
226 * Reasons for the update_lastrec method to be called.
227 */
228 #define LASTREC_UPDATE 0
229 #define LASTREC_INSREC 1
230 #define LASTREC_DELREC 2
231
232
233 /*
234 * Btree cursor structure.
235 * This collects all information needed by the btree code in one place.
236 */
237 typedef struct xfs_btree_cur
238 {
239 struct xfs_trans *bc_tp; /* transaction we're in, if any */
240 struct xfs_mount *bc_mp; /* file system mount struct */
241 const struct xfs_btree_ops *bc_ops;
242 uint bc_flags; /* btree features - below */
243 union {
244 xfs_alloc_rec_incore_t a;
245 xfs_bmbt_irec_t b;
246 xfs_inobt_rec_incore_t i;
247 } bc_rec; /* current insert/search record value */
248 struct xfs_buf *bc_bufs[XFS_BTREE_MAXLEVELS]; /* buf ptr per level */
249 int bc_ptrs[XFS_BTREE_MAXLEVELS]; /* key/record # */
250 __uint8_t bc_ra[XFS_BTREE_MAXLEVELS]; /* readahead bits */
251 #define XFS_BTCUR_LEFTRA 1 /* left sibling has been read-ahead */
252 #define XFS_BTCUR_RIGHTRA 2 /* right sibling has been read-ahead */
253 __uint8_t bc_nlevels; /* number of levels in the tree */
254 __uint8_t bc_blocklog; /* log2(blocksize) of btree blocks */
255 xfs_btnum_t bc_btnum; /* identifies which btree type */
256 union {
257 struct { /* needed for BNO, CNT, INO */
258 struct xfs_buf *agbp; /* agf/agi buffer pointer */
259 xfs_agnumber_t agno; /* ag number */
260 } a;
261 struct { /* needed for BMAP */
262 struct xfs_inode *ip; /* pointer to our inode */
263 struct xfs_bmap_free *flist; /* list to free after */
264 xfs_fsblock_t firstblock; /* 1st blk allocated */
265 int allocated; /* count of alloced */
266 short forksize; /* fork's inode space */
267 char whichfork; /* data or attr fork */
268 char flags; /* flags */
269 #define XFS_BTCUR_BPRV_WASDEL 1 /* was delayed */
270 } b;
271 } bc_private; /* per-btree type data */
272 } xfs_btree_cur_t;
273
274 /* cursor flags */
275 #define XFS_BTREE_LONG_PTRS (1<<0) /* pointers are 64bits long */
276 #define XFS_BTREE_ROOT_IN_INODE (1<<1) /* root may be variable size */
277 #define XFS_BTREE_LASTREC_UPDATE (1<<2) /* track last rec externally */
278
279
280 #define XFS_BTREE_NOERROR 0
281 #define XFS_BTREE_ERROR 1
282
283 /*
284 * Convert from buffer to btree block header.
285 */
286 #define XFS_BUF_TO_BLOCK(bp) ((struct xfs_btree_block *)XFS_BUF_PTR(bp))
287
288
289 /*
290 * Check that block header is ok.
291 */
292 int
293 xfs_btree_check_block(
294 struct xfs_btree_cur *cur, /* btree cursor */
295 struct xfs_btree_block *block, /* generic btree block pointer */
296 int level, /* level of the btree block */
297 struct xfs_buf *bp); /* buffer containing block, if any */
298
299 /*
300 * Check that (long) pointer is ok.
301 */
302 int /* error (0 or EFSCORRUPTED) */
303 xfs_btree_check_lptr(
304 struct xfs_btree_cur *cur, /* btree cursor */
305 xfs_dfsbno_t ptr, /* btree block disk address */
306 int level); /* btree block level */
307
308 /*
309 * Delete the btree cursor.
310 */
311 void
312 xfs_btree_del_cursor(
313 xfs_btree_cur_t *cur, /* btree cursor */
314 int error); /* del because of error */
315
316 /*
317 * Duplicate the btree cursor.
318 * Allocate a new one, copy the record, re-get the buffers.
319 */
320 int /* error */
321 xfs_btree_dup_cursor(
322 xfs_btree_cur_t *cur, /* input cursor */
323 xfs_btree_cur_t **ncur);/* output cursor */
324
325 /*
326 * Get a buffer for the block, return it with no data read.
327 * Long-form addressing.
328 */
329 struct xfs_buf * /* buffer for fsbno */
330 xfs_btree_get_bufl(
331 struct xfs_mount *mp, /* file system mount point */
332 struct xfs_trans *tp, /* transaction pointer */
333 xfs_fsblock_t fsbno, /* file system block number */
334 uint lock); /* lock flags for get_buf */
335
336 /*
337 * Get a buffer for the block, return it with no data read.
338 * Short-form addressing.
339 */
340 struct xfs_buf * /* buffer for agno/agbno */
341 xfs_btree_get_bufs(
342 struct xfs_mount *mp, /* file system mount point */
343 struct xfs_trans *tp, /* transaction pointer */
344 xfs_agnumber_t agno, /* allocation group number */
345 xfs_agblock_t agbno, /* allocation group block number */
346 uint lock); /* lock flags for get_buf */
347
348 /*
349 * Check for the cursor referring to the last block at the given level.
350 */
351 int /* 1=is last block, 0=not last block */
352 xfs_btree_islastblock(
353 xfs_btree_cur_t *cur, /* btree cursor */
354 int level); /* level to check */
355
356 /*
357 * Compute first and last byte offsets for the fields given.
358 * Interprets the offsets table, which contains struct field offsets.
359 */
360 void
361 xfs_btree_offsets(
362 __int64_t fields, /* bitmask of fields */
363 const short *offsets,/* table of field offsets */
364 int nbits, /* number of bits to inspect */
365 int *first, /* output: first byte offset */
366 int *last); /* output: last byte offset */
367
368 /*
369 * Get a buffer for the block, return it read in.
370 * Long-form addressing.
371 */
372 int /* error */
373 xfs_btree_read_bufl(
374 struct xfs_mount *mp, /* file system mount point */
375 struct xfs_trans *tp, /* transaction pointer */
376 xfs_fsblock_t fsbno, /* file system block number */
377 uint lock, /* lock flags for read_buf */
378 struct xfs_buf **bpp, /* buffer for fsbno */
379 int refval);/* ref count value for buffer */
380
381 /*
382 * Get a buffer for the block, return it read in.
383 * Short-form addressing.
384 */
385 int /* error */
386 xfs_btree_read_bufs(
387 struct xfs_mount *mp, /* file system mount point */
388 struct xfs_trans *tp, /* transaction pointer */
389 xfs_agnumber_t agno, /* allocation group number */
390 xfs_agblock_t agbno, /* allocation group block number */
391 uint lock, /* lock flags for read_buf */
392 struct xfs_buf **bpp, /* buffer for agno/agbno */
393 int refval);/* ref count value for buffer */
394
395 /*
396 * Read-ahead the block, don't wait for it, don't return a buffer.
397 * Long-form addressing.
398 */
399 void /* error */
400 xfs_btree_reada_bufl(
401 struct xfs_mount *mp, /* file system mount point */
402 xfs_fsblock_t fsbno, /* file system block number */
403 xfs_extlen_t count); /* count of filesystem blocks */
404
405 /*
406 * Read-ahead the block, don't wait for it, don't return a buffer.
407 * Short-form addressing.
408 */
409 void /* error */
410 xfs_btree_reada_bufs(
411 struct xfs_mount *mp, /* file system mount point */
412 xfs_agnumber_t agno, /* allocation group number */
413 xfs_agblock_t agbno, /* allocation group block number */
414 xfs_extlen_t count); /* count of filesystem blocks */
415
416 /*
417 * Set the buffer for level "lev" in the cursor to bp, releasing
418 * any previous buffer.
419 */
420 void
421 xfs_btree_setbuf(
422 xfs_btree_cur_t *cur, /* btree cursor */
423 int lev, /* level in btree */
424 struct xfs_buf *bp); /* new buffer to set */
425
426
427 /*
428 * Common btree core entry points.
429 */
430 int xfs_btree_increment(struct xfs_btree_cur *, int, int *);
431 int xfs_btree_decrement(struct xfs_btree_cur *, int, int *);
432 int xfs_btree_lookup(struct xfs_btree_cur *, xfs_lookup_t, int *);
433 int xfs_btree_update(struct xfs_btree_cur *, union xfs_btree_rec *);
434 int xfs_btree_new_iroot(struct xfs_btree_cur *, int *, int *);
435 int xfs_btree_kill_iroot(struct xfs_btree_cur *);
436 int xfs_btree_insert(struct xfs_btree_cur *, int *);
437 int xfs_btree_delete(struct xfs_btree_cur *, int *);
438 int xfs_btree_get_rec(struct xfs_btree_cur *, union xfs_btree_rec **, int *);
439
440 /*
441 * Internal btree helpers also used by xfs_bmap.c.
442 */
443 void xfs_btree_log_block(struct xfs_btree_cur *, struct xfs_buf *, int);
444 void xfs_btree_log_recs(struct xfs_btree_cur *, struct xfs_buf *, int, int);
445
446 /*
447 * Helpers.
448 */
xfs_btree_get_numrecs(struct xfs_btree_block * block)449 static inline int xfs_btree_get_numrecs(struct xfs_btree_block *block)
450 {
451 return be16_to_cpu(block->bb_numrecs);
452 }
453
xfs_btree_set_numrecs(struct xfs_btree_block * block,__uint16_t numrecs)454 static inline void xfs_btree_set_numrecs(struct xfs_btree_block *block,
455 __uint16_t numrecs)
456 {
457 block->bb_numrecs = cpu_to_be16(numrecs);
458 }
459
xfs_btree_get_level(struct xfs_btree_block * block)460 static inline int xfs_btree_get_level(struct xfs_btree_block *block)
461 {
462 return be16_to_cpu(block->bb_level);
463 }
464
465
466 /*
467 * Min and max functions for extlen, agblock, fileoff, and filblks types.
468 */
469 #define XFS_EXTLEN_MIN(a,b) min_t(xfs_extlen_t, (a), (b))
470 #define XFS_EXTLEN_MAX(a,b) max_t(xfs_extlen_t, (a), (b))
471 #define XFS_AGBLOCK_MIN(a,b) min_t(xfs_agblock_t, (a), (b))
472 #define XFS_AGBLOCK_MAX(a,b) max_t(xfs_agblock_t, (a), (b))
473 #define XFS_FILEOFF_MIN(a,b) min_t(xfs_fileoff_t, (a), (b))
474 #define XFS_FILEOFF_MAX(a,b) max_t(xfs_fileoff_t, (a), (b))
475 #define XFS_FILBLKS_MIN(a,b) min_t(xfs_filblks_t, (a), (b))
476 #define XFS_FILBLKS_MAX(a,b) max_t(xfs_filblks_t, (a), (b))
477
478 #define XFS_FSB_SANITY_CHECK(mp,fsb) \
479 (XFS_FSB_TO_AGNO(mp, fsb) < mp->m_sb.sb_agcount && \
480 XFS_FSB_TO_AGBNO(mp, fsb) < mp->m_sb.sb_agblocks)
481
482 #endif /* __XFS_BTREE_H__ */
483