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
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
157 /* block allocation / freeing */
158 int (*alloc_block)(struct xfs_btree_cur *cur,
159 union xfs_btree_ptr *start_bno,
160 union xfs_btree_ptr *new_bno,
161 int length, int *stat);
162 int (*free_block)(struct xfs_btree_cur *cur, struct xfs_buf *bp);
163
164 /* update last record information */
165 void (*update_lastrec)(struct xfs_btree_cur *cur,
166 struct xfs_btree_block *block,
167 union xfs_btree_rec *rec,
168 int ptr, int reason);
169
170 /* records in block/level */
171 int (*get_minrecs)(struct xfs_btree_cur *cur, int level);
172 int (*get_maxrecs)(struct xfs_btree_cur *cur, int level);
173
174 /* records on disk. Matter for the root in inode case. */
175 int (*get_dmaxrecs)(struct xfs_btree_cur *cur, int level);
176
177 /* init values of btree structures */
178 void (*init_key_from_rec)(union xfs_btree_key *key,
179 union xfs_btree_rec *rec);
180 void (*init_rec_from_key)(union xfs_btree_key *key,
181 union xfs_btree_rec *rec);
182 void (*init_rec_from_cur)(struct xfs_btree_cur *cur,
183 union xfs_btree_rec *rec);
184 void (*init_ptr_from_cur)(struct xfs_btree_cur *cur,
185 union xfs_btree_ptr *ptr);
186
187 /* difference between key value and cursor value */
188 __int64_t (*key_diff)(struct xfs_btree_cur *cur,
189 union xfs_btree_key *key);
190
191 #ifdef DEBUG
192 /* check that k1 is lower than k2 */
193 int (*keys_inorder)(struct xfs_btree_cur *cur,
194 union xfs_btree_key *k1,
195 union xfs_btree_key *k2);
196
197 /* check that r1 is lower than r2 */
198 int (*recs_inorder)(struct xfs_btree_cur *cur,
199 union xfs_btree_rec *r1,
200 union xfs_btree_rec *r2);
201 #endif
202
203 /* btree tracing */
204 #ifdef XFS_BTREE_TRACE
205 void (*trace_enter)(struct xfs_btree_cur *, const char *,
206 char *, int, int, __psunsigned_t,
207 __psunsigned_t, __psunsigned_t,
208 __psunsigned_t, __psunsigned_t,
209 __psunsigned_t, __psunsigned_t,
210 __psunsigned_t, __psunsigned_t,
211 __psunsigned_t, __psunsigned_t);
212 void (*trace_cursor)(struct xfs_btree_cur *, __uint32_t *,
213 __uint64_t *, __uint64_t *);
214 void (*trace_key)(struct xfs_btree_cur *,
215 union xfs_btree_key *, __uint64_t *,
216 __uint64_t *);
217 void (*trace_record)(struct xfs_btree_cur *,
218 union xfs_btree_rec *, __uint64_t *,
219 __uint64_t *, __uint64_t *);
220 #endif
221 };
222
223 /*
224 * Reasons for the update_lastrec method to be called.
225 */
226 #define LASTREC_UPDATE 0
227 #define LASTREC_INSREC 1
228 #define LASTREC_DELREC 2
229
230
231 /*
232 * Btree cursor structure.
233 * This collects all information needed by the btree code in one place.
234 */
235 typedef struct xfs_btree_cur
236 {
237 struct xfs_trans *bc_tp; /* transaction we're in, if any */
238 struct xfs_mount *bc_mp; /* file system mount struct */
239 const struct xfs_btree_ops *bc_ops;
240 uint bc_flags; /* btree features - below */
241 union {
242 xfs_alloc_rec_incore_t a;
243 xfs_bmbt_irec_t b;
244 xfs_inobt_rec_incore_t i;
245 } bc_rec; /* current insert/search record value */
246 struct xfs_buf *bc_bufs[XFS_BTREE_MAXLEVELS]; /* buf ptr per level */
247 int bc_ptrs[XFS_BTREE_MAXLEVELS]; /* key/record # */
248 __uint8_t bc_ra[XFS_BTREE_MAXLEVELS]; /* readahead bits */
249 #define XFS_BTCUR_LEFTRA 1 /* left sibling has been read-ahead */
250 #define XFS_BTCUR_RIGHTRA 2 /* right sibling has been read-ahead */
251 __uint8_t bc_nlevels; /* number of levels in the tree */
252 __uint8_t bc_blocklog; /* log2(blocksize) of btree blocks */
253 xfs_btnum_t bc_btnum; /* identifies which btree type */
254 union {
255 struct { /* needed for BNO, CNT, INO */
256 struct xfs_buf *agbp; /* agf/agi buffer pointer */
257 xfs_agnumber_t agno; /* ag number */
258 } a;
259 struct { /* needed for BMAP */
260 struct xfs_inode *ip; /* pointer to our inode */
261 struct xfs_bmap_free *flist; /* list to free after */
262 xfs_fsblock_t firstblock; /* 1st blk allocated */
263 int allocated; /* count of alloced */
264 short forksize; /* fork's inode space */
265 char whichfork; /* data or attr fork */
266 char flags; /* flags */
267 #define XFS_BTCUR_BPRV_WASDEL 1 /* was delayed */
268 } b;
269 } bc_private; /* per-btree type data */
270 } xfs_btree_cur_t;
271
272 /* cursor flags */
273 #define XFS_BTREE_LONG_PTRS (1<<0) /* pointers are 64bits long */
274 #define XFS_BTREE_ROOT_IN_INODE (1<<1) /* root may be variable size */
275 #define XFS_BTREE_LASTREC_UPDATE (1<<2) /* track last rec externally */
276
277
278 #define XFS_BTREE_NOERROR 0
279 #define XFS_BTREE_ERROR 1
280
281 /*
282 * Convert from buffer to btree block header.
283 */
284 #define XFS_BUF_TO_BLOCK(bp) ((struct xfs_btree_block *)XFS_BUF_PTR(bp))
285
286
287 /*
288 * Check that block header is ok.
289 */
290 int
291 xfs_btree_check_block(
292 struct xfs_btree_cur *cur, /* btree cursor */
293 struct xfs_btree_block *block, /* generic btree block pointer */
294 int level, /* level of the btree block */
295 struct xfs_buf *bp); /* buffer containing block, if any */
296
297 /*
298 * Check that (long) pointer is ok.
299 */
300 int /* error (0 or EFSCORRUPTED) */
301 xfs_btree_check_lptr(
302 struct xfs_btree_cur *cur, /* btree cursor */
303 xfs_dfsbno_t ptr, /* btree block disk address */
304 int level); /* btree block level */
305
306 /*
307 * Delete the btree cursor.
308 */
309 void
310 xfs_btree_del_cursor(
311 xfs_btree_cur_t *cur, /* btree cursor */
312 int error); /* del because of error */
313
314 /*
315 * Duplicate the btree cursor.
316 * Allocate a new one, copy the record, re-get the buffers.
317 */
318 int /* error */
319 xfs_btree_dup_cursor(
320 xfs_btree_cur_t *cur, /* input cursor */
321 xfs_btree_cur_t **ncur);/* output cursor */
322
323 /*
324 * Get a buffer for the block, return it with no data read.
325 * Long-form addressing.
326 */
327 struct xfs_buf * /* buffer for fsbno */
328 xfs_btree_get_bufl(
329 struct xfs_mount *mp, /* file system mount point */
330 struct xfs_trans *tp, /* transaction pointer */
331 xfs_fsblock_t fsbno, /* file system block number */
332 uint lock); /* lock flags for get_buf */
333
334 /*
335 * Get a buffer for the block, return it with no data read.
336 * Short-form addressing.
337 */
338 struct xfs_buf * /* buffer for agno/agbno */
339 xfs_btree_get_bufs(
340 struct xfs_mount *mp, /* file system mount point */
341 struct xfs_trans *tp, /* transaction pointer */
342 xfs_agnumber_t agno, /* allocation group number */
343 xfs_agblock_t agbno, /* allocation group block number */
344 uint lock); /* lock flags for get_buf */
345
346 /*
347 * Check for the cursor referring to the last block at the given level.
348 */
349 int /* 1=is last block, 0=not last block */
350 xfs_btree_islastblock(
351 xfs_btree_cur_t *cur, /* btree cursor */
352 int level); /* level to check */
353
354 /*
355 * Compute first and last byte offsets for the fields given.
356 * Interprets the offsets table, which contains struct field offsets.
357 */
358 void
359 xfs_btree_offsets(
360 __int64_t fields, /* bitmask of fields */
361 const short *offsets,/* table of field offsets */
362 int nbits, /* number of bits to inspect */
363 int *first, /* output: first byte offset */
364 int *last); /* output: last byte offset */
365
366 /*
367 * Get a buffer for the block, return it read in.
368 * Long-form addressing.
369 */
370 int /* error */
371 xfs_btree_read_bufl(
372 struct xfs_mount *mp, /* file system mount point */
373 struct xfs_trans *tp, /* transaction pointer */
374 xfs_fsblock_t fsbno, /* file system block number */
375 uint lock, /* lock flags for read_buf */
376 struct xfs_buf **bpp, /* buffer for fsbno */
377 int refval);/* ref count value for buffer */
378
379 /*
380 * Read-ahead the block, don't wait for it, don't return a buffer.
381 * Long-form addressing.
382 */
383 void /* error */
384 xfs_btree_reada_bufl(
385 struct xfs_mount *mp, /* file system mount point */
386 xfs_fsblock_t fsbno, /* file system block number */
387 xfs_extlen_t count); /* count of filesystem blocks */
388
389 /*
390 * Read-ahead the block, don't wait for it, don't return a buffer.
391 * Short-form addressing.
392 */
393 void /* error */
394 xfs_btree_reada_bufs(
395 struct xfs_mount *mp, /* file system mount point */
396 xfs_agnumber_t agno, /* allocation group number */
397 xfs_agblock_t agbno, /* allocation group block number */
398 xfs_extlen_t count); /* count of filesystem blocks */
399
400
401 /*
402 * Common btree core entry points.
403 */
404 int xfs_btree_increment(struct xfs_btree_cur *, int, int *);
405 int xfs_btree_decrement(struct xfs_btree_cur *, int, int *);
406 int xfs_btree_lookup(struct xfs_btree_cur *, xfs_lookup_t, int *);
407 int xfs_btree_update(struct xfs_btree_cur *, union xfs_btree_rec *);
408 int xfs_btree_new_iroot(struct xfs_btree_cur *, int *, int *);
409 int xfs_btree_insert(struct xfs_btree_cur *, int *);
410 int xfs_btree_delete(struct xfs_btree_cur *, int *);
411 int xfs_btree_get_rec(struct xfs_btree_cur *, union xfs_btree_rec **, int *);
412
413 /*
414 * Internal btree helpers also used by xfs_bmap.c.
415 */
416 void xfs_btree_log_block(struct xfs_btree_cur *, struct xfs_buf *, int);
417 void xfs_btree_log_recs(struct xfs_btree_cur *, struct xfs_buf *, int, int);
418
419 /*
420 * Helpers.
421 */
xfs_btree_get_numrecs(struct xfs_btree_block * block)422 static inline int xfs_btree_get_numrecs(struct xfs_btree_block *block)
423 {
424 return be16_to_cpu(block->bb_numrecs);
425 }
426
xfs_btree_set_numrecs(struct xfs_btree_block * block,__uint16_t numrecs)427 static inline void xfs_btree_set_numrecs(struct xfs_btree_block *block,
428 __uint16_t numrecs)
429 {
430 block->bb_numrecs = cpu_to_be16(numrecs);
431 }
432
xfs_btree_get_level(struct xfs_btree_block * block)433 static inline int xfs_btree_get_level(struct xfs_btree_block *block)
434 {
435 return be16_to_cpu(block->bb_level);
436 }
437
438
439 /*
440 * Min and max functions for extlen, agblock, fileoff, and filblks types.
441 */
442 #define XFS_EXTLEN_MIN(a,b) min_t(xfs_extlen_t, (a), (b))
443 #define XFS_EXTLEN_MAX(a,b) max_t(xfs_extlen_t, (a), (b))
444 #define XFS_AGBLOCK_MIN(a,b) min_t(xfs_agblock_t, (a), (b))
445 #define XFS_AGBLOCK_MAX(a,b) max_t(xfs_agblock_t, (a), (b))
446 #define XFS_FILEOFF_MIN(a,b) min_t(xfs_fileoff_t, (a), (b))
447 #define XFS_FILEOFF_MAX(a,b) max_t(xfs_fileoff_t, (a), (b))
448 #define XFS_FILBLKS_MIN(a,b) min_t(xfs_filblks_t, (a), (b))
449 #define XFS_FILBLKS_MAX(a,b) max_t(xfs_filblks_t, (a), (b))
450
451 #define XFS_FSB_SANITY_CHECK(mp,fsb) \
452 (XFS_FSB_TO_AGNO(mp, fsb) < mp->m_sb.sb_agcount && \
453 XFS_FSB_TO_AGBNO(mp, fsb) < mp->m_sb.sb_agblocks)
454
455 #endif /* __XFS_BTREE_H__ */
456