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
204 /*
205 * Reasons for the update_lastrec method to be called.
206 */
207 #define LASTREC_UPDATE 0
208 #define LASTREC_INSREC 1
209 #define LASTREC_DELREC 2
210
211
212 /*
213 * Btree cursor structure.
214 * This collects all information needed by the btree code in one place.
215 */
216 typedef struct xfs_btree_cur
217 {
218 struct xfs_trans *bc_tp; /* transaction we're in, if any */
219 struct xfs_mount *bc_mp; /* file system mount struct */
220 const struct xfs_btree_ops *bc_ops;
221 uint bc_flags; /* btree features - below */
222 union {
223 xfs_alloc_rec_incore_t a;
224 xfs_bmbt_irec_t b;
225 xfs_inobt_rec_incore_t i;
226 } bc_rec; /* current insert/search record value */
227 struct xfs_buf *bc_bufs[XFS_BTREE_MAXLEVELS]; /* buf ptr per level */
228 int bc_ptrs[XFS_BTREE_MAXLEVELS]; /* key/record # */
229 __uint8_t bc_ra[XFS_BTREE_MAXLEVELS]; /* readahead bits */
230 #define XFS_BTCUR_LEFTRA 1 /* left sibling has been read-ahead */
231 #define XFS_BTCUR_RIGHTRA 2 /* right sibling has been read-ahead */
232 __uint8_t bc_nlevels; /* number of levels in the tree */
233 __uint8_t bc_blocklog; /* log2(blocksize) of btree blocks */
234 xfs_btnum_t bc_btnum; /* identifies which btree type */
235 union {
236 struct { /* needed for BNO, CNT, INO */
237 struct xfs_buf *agbp; /* agf/agi buffer pointer */
238 xfs_agnumber_t agno; /* ag number */
239 } a;
240 struct { /* needed for BMAP */
241 struct xfs_inode *ip; /* pointer to our inode */
242 struct xfs_bmap_free *flist; /* list to free after */
243 xfs_fsblock_t firstblock; /* 1st blk allocated */
244 int allocated; /* count of alloced */
245 short forksize; /* fork's inode space */
246 char whichfork; /* data or attr fork */
247 char flags; /* flags */
248 #define XFS_BTCUR_BPRV_WASDEL 1 /* was delayed */
249 } b;
250 } bc_private; /* per-btree type data */
251 } xfs_btree_cur_t;
252
253 /* cursor flags */
254 #define XFS_BTREE_LONG_PTRS (1<<0) /* pointers are 64bits long */
255 #define XFS_BTREE_ROOT_IN_INODE (1<<1) /* root may be variable size */
256 #define XFS_BTREE_LASTREC_UPDATE (1<<2) /* track last rec externally */
257
258
259 #define XFS_BTREE_NOERROR 0
260 #define XFS_BTREE_ERROR 1
261
262 /*
263 * Convert from buffer to btree block header.
264 */
265 #define XFS_BUF_TO_BLOCK(bp) ((struct xfs_btree_block *)((bp)->b_addr))
266
267
268 /*
269 * Check that block header is ok.
270 */
271 int
272 xfs_btree_check_block(
273 struct xfs_btree_cur *cur, /* btree cursor */
274 struct xfs_btree_block *block, /* generic btree block pointer */
275 int level, /* level of the btree block */
276 struct xfs_buf *bp); /* buffer containing block, if any */
277
278 /*
279 * Check that (long) pointer is ok.
280 */
281 int /* error (0 or EFSCORRUPTED) */
282 xfs_btree_check_lptr(
283 struct xfs_btree_cur *cur, /* btree cursor */
284 xfs_dfsbno_t ptr, /* btree block disk address */
285 int level); /* btree block level */
286
287 /*
288 * Delete the btree cursor.
289 */
290 void
291 xfs_btree_del_cursor(
292 xfs_btree_cur_t *cur, /* btree cursor */
293 int error); /* del because of error */
294
295 /*
296 * Duplicate the btree cursor.
297 * Allocate a new one, copy the record, re-get the buffers.
298 */
299 int /* error */
300 xfs_btree_dup_cursor(
301 xfs_btree_cur_t *cur, /* input cursor */
302 xfs_btree_cur_t **ncur);/* output cursor */
303
304 /*
305 * Get a buffer for the block, return it with no data read.
306 * Long-form addressing.
307 */
308 struct xfs_buf * /* buffer for fsbno */
309 xfs_btree_get_bufl(
310 struct xfs_mount *mp, /* file system mount point */
311 struct xfs_trans *tp, /* transaction pointer */
312 xfs_fsblock_t fsbno, /* file system block number */
313 uint lock); /* lock flags for get_buf */
314
315 /*
316 * Get a buffer for the block, return it with no data read.
317 * Short-form addressing.
318 */
319 struct xfs_buf * /* buffer for agno/agbno */
320 xfs_btree_get_bufs(
321 struct xfs_mount *mp, /* file system mount point */
322 struct xfs_trans *tp, /* transaction pointer */
323 xfs_agnumber_t agno, /* allocation group number */
324 xfs_agblock_t agbno, /* allocation group block number */
325 uint lock); /* lock flags for get_buf */
326
327 /*
328 * Check for the cursor referring to the last block at the given level.
329 */
330 int /* 1=is last block, 0=not last block */
331 xfs_btree_islastblock(
332 xfs_btree_cur_t *cur, /* btree cursor */
333 int level); /* level to check */
334
335 /*
336 * Compute first and last byte offsets for the fields given.
337 * Interprets the offsets table, which contains struct field offsets.
338 */
339 void
340 xfs_btree_offsets(
341 __int64_t fields, /* bitmask of fields */
342 const short *offsets,/* table of field offsets */
343 int nbits, /* number of bits to inspect */
344 int *first, /* output: first byte offset */
345 int *last); /* output: last byte offset */
346
347 /*
348 * Get a buffer for the block, return it read in.
349 * Long-form addressing.
350 */
351 int /* error */
352 xfs_btree_read_bufl(
353 struct xfs_mount *mp, /* file system mount point */
354 struct xfs_trans *tp, /* transaction pointer */
355 xfs_fsblock_t fsbno, /* file system block number */
356 uint lock, /* lock flags for read_buf */
357 struct xfs_buf **bpp, /* buffer for fsbno */
358 int refval);/* ref count value for buffer */
359
360 /*
361 * Read-ahead the block, don't wait for it, don't return a buffer.
362 * Long-form addressing.
363 */
364 void /* error */
365 xfs_btree_reada_bufl(
366 struct xfs_mount *mp, /* file system mount point */
367 xfs_fsblock_t fsbno, /* file system block number */
368 xfs_extlen_t count); /* count of filesystem blocks */
369
370 /*
371 * Read-ahead the block, don't wait for it, don't return a buffer.
372 * Short-form addressing.
373 */
374 void /* error */
375 xfs_btree_reada_bufs(
376 struct xfs_mount *mp, /* file system mount point */
377 xfs_agnumber_t agno, /* allocation group number */
378 xfs_agblock_t agbno, /* allocation group block number */
379 xfs_extlen_t count); /* count of filesystem blocks */
380
381
382 /*
383 * Common btree core entry points.
384 */
385 int xfs_btree_increment(struct xfs_btree_cur *, int, int *);
386 int xfs_btree_decrement(struct xfs_btree_cur *, int, int *);
387 int xfs_btree_lookup(struct xfs_btree_cur *, xfs_lookup_t, int *);
388 int xfs_btree_update(struct xfs_btree_cur *, union xfs_btree_rec *);
389 int xfs_btree_new_iroot(struct xfs_btree_cur *, int *, int *);
390 int xfs_btree_insert(struct xfs_btree_cur *, int *);
391 int xfs_btree_delete(struct xfs_btree_cur *, int *);
392 int xfs_btree_get_rec(struct xfs_btree_cur *, union xfs_btree_rec **, int *);
393
394 /*
395 * Internal btree helpers also used by xfs_bmap.c.
396 */
397 void xfs_btree_log_block(struct xfs_btree_cur *, struct xfs_buf *, int);
398 void xfs_btree_log_recs(struct xfs_btree_cur *, struct xfs_buf *, int, int);
399
400 /*
401 * Helpers.
402 */
xfs_btree_get_numrecs(struct xfs_btree_block * block)403 static inline int xfs_btree_get_numrecs(struct xfs_btree_block *block)
404 {
405 return be16_to_cpu(block->bb_numrecs);
406 }
407
xfs_btree_set_numrecs(struct xfs_btree_block * block,__uint16_t numrecs)408 static inline void xfs_btree_set_numrecs(struct xfs_btree_block *block,
409 __uint16_t numrecs)
410 {
411 block->bb_numrecs = cpu_to_be16(numrecs);
412 }
413
xfs_btree_get_level(struct xfs_btree_block * block)414 static inline int xfs_btree_get_level(struct xfs_btree_block *block)
415 {
416 return be16_to_cpu(block->bb_level);
417 }
418
419
420 /*
421 * Min and max functions for extlen, agblock, fileoff, and filblks types.
422 */
423 #define XFS_EXTLEN_MIN(a,b) min_t(xfs_extlen_t, (a), (b))
424 #define XFS_EXTLEN_MAX(a,b) max_t(xfs_extlen_t, (a), (b))
425 #define XFS_AGBLOCK_MIN(a,b) min_t(xfs_agblock_t, (a), (b))
426 #define XFS_AGBLOCK_MAX(a,b) max_t(xfs_agblock_t, (a), (b))
427 #define XFS_FILEOFF_MIN(a,b) min_t(xfs_fileoff_t, (a), (b))
428 #define XFS_FILEOFF_MAX(a,b) max_t(xfs_fileoff_t, (a), (b))
429 #define XFS_FILBLKS_MIN(a,b) min_t(xfs_filblks_t, (a), (b))
430 #define XFS_FILBLKS_MAX(a,b) max_t(xfs_filblks_t, (a), (b))
431
432 #define XFS_FSB_SANITY_CHECK(mp,fsb) \
433 (XFS_FSB_TO_AGNO(mp, fsb) < mp->m_sb.sb_agcount && \
434 XFS_FSB_TO_AGBNO(mp, fsb) < mp->m_sb.sb_agblocks)
435
436 /*
437 * Trace hooks. Currently not implemented as they need to be ported
438 * over to the generic tracing functionality, which is some effort.
439 *
440 * i,j = integer (32 bit)
441 * b = btree block buffer (xfs_buf_t)
442 * p = btree ptr
443 * r = btree record
444 * k = btree key
445 */
446 #define XFS_BTREE_TRACE_ARGBI(c, b, i)
447 #define XFS_BTREE_TRACE_ARGBII(c, b, i, j)
448 #define XFS_BTREE_TRACE_ARGI(c, i)
449 #define XFS_BTREE_TRACE_ARGIPK(c, i, p, s)
450 #define XFS_BTREE_TRACE_ARGIPR(c, i, p, r)
451 #define XFS_BTREE_TRACE_ARGIK(c, i, k)
452 #define XFS_BTREE_TRACE_ARGR(c, r)
453 #define XFS_BTREE_TRACE_CURSOR(c, t)
454
455 #endif /* __XFS_BTREE_H__ */
456