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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Nathan Scott7b718762005-11-02 14:58:39 +11002 * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 *
Nathan Scott7b718762005-11-02 14:58:39 +11005 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 * published by the Free Software Foundation.
8 *
Nathan Scott7b718762005-11-02 14:58:39 +11009 * 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.
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 *
Nathan Scott7b718762005-11-02 14:58:39 +110014 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070017 */
18#ifndef __XFS_BTREE_H__
19#define __XFS_BTREE_H__
20
21struct xfs_buf;
22struct xfs_bmap_free;
23struct xfs_inode;
24struct xfs_mount;
25struct xfs_trans;
26
27/*
28 * This nonsense is to make -wlint happy.
29 */
30#define XFS_LOOKUP_EQ ((xfs_lookup_t)XFS_LOOKUP_EQi)
31#define XFS_LOOKUP_LE ((xfs_lookup_t)XFS_LOOKUP_LEi)
32#define XFS_LOOKUP_GE ((xfs_lookup_t)XFS_LOOKUP_GEi)
33
34#define XFS_BTNUM_BNO ((xfs_btnum_t)XFS_BTNUM_BNOi)
35#define XFS_BTNUM_CNT ((xfs_btnum_t)XFS_BTNUM_CNTi)
36#define XFS_BTNUM_BMAP ((xfs_btnum_t)XFS_BTNUM_BMAPi)
37#define XFS_BTNUM_INO ((xfs_btnum_t)XFS_BTNUM_INOi)
38
39/*
40 * Short form header: space allocation btrees.
41 */
Christoph Hellwig16259e72005-11-02 15:11:25 +110042typedef struct xfs_btree_sblock {
43 __be32 bb_magic; /* magic number for block type */
44 __be16 bb_level; /* 0 is a leaf */
45 __be16 bb_numrecs; /* current # of data records */
46 __be32 bb_leftsib; /* left sibling block or NULLAGBLOCK */
47 __be32 bb_rightsib; /* right sibling block or NULLAGBLOCK */
Linus Torvalds1da177e2005-04-16 15:20:36 -070048} xfs_btree_sblock_t;
49
50/*
51 * Long form header: bmap btrees.
52 */
Christoph Hellwig16259e72005-11-02 15:11:25 +110053typedef struct xfs_btree_lblock {
54 __be32 bb_magic; /* magic number for block type */
55 __be16 bb_level; /* 0 is a leaf */
56 __be16 bb_numrecs; /* current # of data records */
57 __be64 bb_leftsib; /* left sibling block or NULLDFSBNO */
58 __be64 bb_rightsib; /* right sibling block or NULLDFSBNO */
Linus Torvalds1da177e2005-04-16 15:20:36 -070059} xfs_btree_lblock_t;
60
61/*
62 * Combined header and structure, used by common code.
63 */
64typedef struct xfs_btree_hdr
65{
Christoph Hellwig16259e72005-11-02 15:11:25 +110066 __be32 bb_magic; /* magic number for block type */
67 __be16 bb_level; /* 0 is a leaf */
68 __be16 bb_numrecs; /* current # of data records */
Linus Torvalds1da177e2005-04-16 15:20:36 -070069} xfs_btree_hdr_t;
70
Christoph Hellwig16259e72005-11-02 15:11:25 +110071typedef struct xfs_btree_block {
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 xfs_btree_hdr_t bb_h; /* header */
Christoph Hellwig16259e72005-11-02 15:11:25 +110073 union {
74 struct {
75 __be32 bb_leftsib;
76 __be32 bb_rightsib;
77 } s; /* short form pointers */
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 struct {
Christoph Hellwig16259e72005-11-02 15:11:25 +110079 __be64 bb_leftsib;
80 __be64 bb_rightsib;
81 } l; /* long form pointers */
82 } bb_u; /* rest */
Linus Torvalds1da177e2005-04-16 15:20:36 -070083} xfs_btree_block_t;
84
85/*
86 * For logging record fields.
87 */
88#define XFS_BB_MAGIC 0x01
89#define XFS_BB_LEVEL 0x02
90#define XFS_BB_NUMRECS 0x04
91#define XFS_BB_LEFTSIB 0x08
92#define XFS_BB_RIGHTSIB 0x10
93#define XFS_BB_NUM_BITS 5
94#define XFS_BB_ALL_BITS ((1 << XFS_BB_NUM_BITS) - 1)
95
96/*
97 * Boolean to select which form of xfs_btree_block_t.bb_u to use.
98 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070099#define XFS_BTREE_LONG_PTRS(btnum) ((btnum) == XFS_BTNUM_BMAP)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100
101/*
102 * Magic numbers for btree blocks.
103 */
104extern const __uint32_t xfs_magics[];
105
106/*
107 * Maximum and minimum records in a btree block.
108 * Given block size, type prefix, and leaf flag (0 or 1).
109 * The divisor below is equivalent to lf ? (e1) : (e2) but that produces
110 * compiler warnings.
111 */
112#define XFS_BTREE_BLOCK_MAXRECS(bsz,t,lf) \
113 ((int)(((bsz) - (uint)sizeof(t ## _block_t)) / \
114 (((lf) * (uint)sizeof(t ## _rec_t)) + \
115 ((1 - (lf)) * \
116 ((uint)sizeof(t ## _key_t) + (uint)sizeof(t ## _ptr_t))))))
117#define XFS_BTREE_BLOCK_MINRECS(bsz,t,lf) \
118 (XFS_BTREE_BLOCK_MAXRECS(bsz,t,lf) / 2)
119
120/*
121 * Record, key, and pointer address calculation macros.
122 * Given block size, type prefix, block pointer, and index of requested entry
123 * (first entry numbered 1).
124 */
125#define XFS_BTREE_REC_ADDR(bsz,t,bb,i,mxr) \
126 ((t ## _rec_t *)((char *)(bb) + sizeof(t ## _block_t) + \
127 ((i) - 1) * sizeof(t ## _rec_t)))
128#define XFS_BTREE_KEY_ADDR(bsz,t,bb,i,mxr) \
129 ((t ## _key_t *)((char *)(bb) + sizeof(t ## _block_t) + \
130 ((i) - 1) * sizeof(t ## _key_t)))
131#define XFS_BTREE_PTR_ADDR(bsz,t,bb,i,mxr) \
132 ((t ## _ptr_t *)((char *)(bb) + sizeof(t ## _block_t) + \
133 (mxr) * sizeof(t ## _key_t) + ((i) - 1) * sizeof(t ## _ptr_t)))
134
135#define XFS_BTREE_MAXLEVELS 8 /* max of all btrees */
136
137/*
138 * Btree cursor structure.
139 * This collects all information needed by the btree code in one place.
140 */
141typedef struct xfs_btree_cur
142{
143 struct xfs_trans *bc_tp; /* transaction we're in, if any */
144 struct xfs_mount *bc_mp; /* file system mount struct */
145 union {
Christoph Hellwig16259e72005-11-02 15:11:25 +1100146 xfs_alloc_rec_incore_t a;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 xfs_bmbt_irec_t b;
Christoph Hellwig61a25842006-09-28 10:57:04 +1000148 xfs_inobt_rec_incore_t i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 } bc_rec; /* current insert/search record value */
150 struct xfs_buf *bc_bufs[XFS_BTREE_MAXLEVELS]; /* buf ptr per level */
151 int bc_ptrs[XFS_BTREE_MAXLEVELS]; /* key/record # */
152 __uint8_t bc_ra[XFS_BTREE_MAXLEVELS]; /* readahead bits */
153#define XFS_BTCUR_LEFTRA 1 /* left sibling has been read-ahead */
154#define XFS_BTCUR_RIGHTRA 2 /* right sibling has been read-ahead */
155 __uint8_t bc_nlevels; /* number of levels in the tree */
156 __uint8_t bc_blocklog; /* log2(blocksize) of btree blocks */
157 xfs_btnum_t bc_btnum; /* identifies which btree type */
158 union {
159 struct { /* needed for BNO, CNT */
160 struct xfs_buf *agbp; /* agf buffer pointer */
161 xfs_agnumber_t agno; /* ag number */
162 } a;
163 struct { /* needed for BMAP */
164 struct xfs_inode *ip; /* pointer to our inode */
165 struct xfs_bmap_free *flist; /* list to free after */
166 xfs_fsblock_t firstblock; /* 1st blk allocated */
167 int allocated; /* count of alloced */
168 short forksize; /* fork's inode space */
169 char whichfork; /* data or attr fork */
170 char flags; /* flags */
171#define XFS_BTCUR_BPRV_WASDEL 1 /* was delayed */
172 } b;
173 struct { /* needed for INO */
174 struct xfs_buf *agbp; /* agi buffer pointer */
175 xfs_agnumber_t agno; /* ag number */
176 } i;
177 } bc_private; /* per-btree type data */
178} xfs_btree_cur_t;
179
180#define XFS_BTREE_NOERROR 0
181#define XFS_BTREE_ERROR 1
182
183/*
184 * Convert from buffer to btree block header.
185 */
Nathan Scotta844f452005-11-02 14:38:42 +1100186#define XFS_BUF_TO_BLOCK(bp) ((xfs_btree_block_t *)XFS_BUF_PTR(bp))
187#define XFS_BUF_TO_LBLOCK(bp) ((xfs_btree_lblock_t *)XFS_BUF_PTR(bp))
188#define XFS_BUF_TO_SBLOCK(bp) ((xfs_btree_sblock_t *)XFS_BUF_PTR(bp))
189
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190
191#ifdef __KERNEL__
192
193#ifdef DEBUG
194/*
195 * Debug routine: check that block header is ok.
196 */
197void
198xfs_btree_check_block(
199 xfs_btree_cur_t *cur, /* btree cursor */
200 xfs_btree_block_t *block, /* generic btree block pointer */
201 int level, /* level of the btree block */
202 struct xfs_buf *bp); /* buffer containing block, if any */
203
204/*
205 * Debug routine: check that keys are in the right order.
206 */
207void
208xfs_btree_check_key(
209 xfs_btnum_t btnum, /* btree identifier */
210 void *ak1, /* pointer to left (lower) key */
211 void *ak2); /* pointer to right (higher) key */
212
213/*
214 * Debug routine: check that records are in the right order.
215 */
216void
217xfs_btree_check_rec(
218 xfs_btnum_t btnum, /* btree identifier */
219 void *ar1, /* pointer to left (lower) record */
220 void *ar2); /* pointer to right (higher) record */
221#else
222#define xfs_btree_check_block(a,b,c,d)
223#define xfs_btree_check_key(a,b,c)
224#define xfs_btree_check_rec(a,b,c)
225#endif /* DEBUG */
226
227/*
228 * Checking routine: check that long form block header is ok.
229 */
230int /* error (0 or EFSCORRUPTED) */
231xfs_btree_check_lblock(
232 xfs_btree_cur_t *cur, /* btree cursor */
233 xfs_btree_lblock_t *block, /* btree long form block pointer */
234 int level, /* level of the btree block */
235 struct xfs_buf *bp); /* buffer containing block, if any */
236
237/*
238 * Checking routine: check that (long) pointer is ok.
239 */
240int /* error (0 or EFSCORRUPTED) */
241xfs_btree_check_lptr(
242 xfs_btree_cur_t *cur, /* btree cursor */
243 xfs_dfsbno_t ptr, /* btree block disk address */
244 int level); /* btree block level */
245
Christoph Hellwigb113bcb2006-09-28 10:57:42 +1000246#define xfs_btree_check_lptr_disk(cur, ptr, level) \
Christoph Hellwig576039c2006-09-28 10:58:06 +1000247 xfs_btree_check_lptr(cur, be64_to_cpu(ptr), level)
Christoph Hellwigb113bcb2006-09-28 10:57:42 +1000248
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249/*
250 * Checking routine: check that short form block header is ok.
251 */
252int /* error (0 or EFSCORRUPTED) */
253xfs_btree_check_sblock(
254 xfs_btree_cur_t *cur, /* btree cursor */
255 xfs_btree_sblock_t *block, /* btree short form block pointer */
256 int level, /* level of the btree block */
257 struct xfs_buf *bp); /* buffer containing block */
258
259/*
260 * Checking routine: check that (short) pointer is ok.
261 */
262int /* error (0 or EFSCORRUPTED) */
263xfs_btree_check_sptr(
264 xfs_btree_cur_t *cur, /* btree cursor */
265 xfs_agblock_t ptr, /* btree block disk address */
266 int level); /* btree block level */
267
268/*
269 * Delete the btree cursor.
270 */
271void
272xfs_btree_del_cursor(
273 xfs_btree_cur_t *cur, /* btree cursor */
274 int error); /* del because of error */
275
276/*
277 * Duplicate the btree cursor.
278 * Allocate a new one, copy the record, re-get the buffers.
279 */
280int /* error */
281xfs_btree_dup_cursor(
282 xfs_btree_cur_t *cur, /* input cursor */
283 xfs_btree_cur_t **ncur);/* output cursor */
284
285/*
286 * Change the cursor to point to the first record in the current block
287 * at the given level. Other levels are unaffected.
288 */
289int /* success=1, failure=0 */
290xfs_btree_firstrec(
291 xfs_btree_cur_t *cur, /* btree cursor */
292 int level); /* level to change */
293
294/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295 * Get a buffer for the block, return it with no data read.
296 * Long-form addressing.
297 */
298struct xfs_buf * /* buffer for fsbno */
299xfs_btree_get_bufl(
300 struct xfs_mount *mp, /* file system mount point */
301 struct xfs_trans *tp, /* transaction pointer */
302 xfs_fsblock_t fsbno, /* file system block number */
303 uint lock); /* lock flags for get_buf */
304
305/*
306 * Get a buffer for the block, return it with no data read.
307 * Short-form addressing.
308 */
309struct xfs_buf * /* buffer for agno/agbno */
310xfs_btree_get_bufs(
311 struct xfs_mount *mp, /* file system mount point */
312 struct xfs_trans *tp, /* transaction pointer */
313 xfs_agnumber_t agno, /* allocation group number */
314 xfs_agblock_t agbno, /* allocation group block number */
315 uint lock); /* lock flags for get_buf */
316
317/*
318 * Allocate a new btree cursor.
319 * The cursor is either for allocation (A) or bmap (B).
320 */
321xfs_btree_cur_t * /* new btree cursor */
322xfs_btree_init_cursor(
323 struct xfs_mount *mp, /* file system mount point */
324 struct xfs_trans *tp, /* transaction pointer */
325 struct xfs_buf *agbp, /* (A only) buffer for agf structure */
326 xfs_agnumber_t agno, /* (A only) allocation group number */
327 xfs_btnum_t btnum, /* btree identifier */
328 struct xfs_inode *ip, /* (B only) inode owning the btree */
329 int whichfork); /* (B only) data/attr fork */
330
331/*
332 * Check for the cursor referring to the last block at the given level.
333 */
334int /* 1=is last block, 0=not last block */
335xfs_btree_islastblock(
336 xfs_btree_cur_t *cur, /* btree cursor */
337 int level); /* level to check */
338
339/*
340 * Change the cursor to point to the last record in the current block
341 * at the given level. Other levels are unaffected.
342 */
343int /* success=1, failure=0 */
344xfs_btree_lastrec(
345 xfs_btree_cur_t *cur, /* btree cursor */
346 int level); /* level to change */
347
348/*
349 * Compute first and last byte offsets for the fields given.
350 * Interprets the offsets table, which contains struct field offsets.
351 */
352void
353xfs_btree_offsets(
354 __int64_t fields, /* bitmask of fields */
355 const short *offsets,/* table of field offsets */
356 int nbits, /* number of bits to inspect */
357 int *first, /* output: first byte offset */
358 int *last); /* output: last byte offset */
359
360/*
361 * Get a buffer for the block, return it read in.
362 * Long-form addressing.
363 */
364int /* error */
365xfs_btree_read_bufl(
366 struct xfs_mount *mp, /* file system mount point */
367 struct xfs_trans *tp, /* transaction pointer */
368 xfs_fsblock_t fsbno, /* file system block number */
369 uint lock, /* lock flags for read_buf */
370 struct xfs_buf **bpp, /* buffer for fsbno */
371 int refval);/* ref count value for buffer */
372
373/*
374 * Get a buffer for the block, return it read in.
375 * Short-form addressing.
376 */
377int /* error */
378xfs_btree_read_bufs(
379 struct xfs_mount *mp, /* file system mount point */
380 struct xfs_trans *tp, /* transaction pointer */
381 xfs_agnumber_t agno, /* allocation group number */
382 xfs_agblock_t agbno, /* allocation group block number */
383 uint lock, /* lock flags for read_buf */
384 struct xfs_buf **bpp, /* buffer for agno/agbno */
385 int refval);/* ref count value for buffer */
386
387/*
388 * Read-ahead the block, don't wait for it, don't return a buffer.
389 * Long-form addressing.
390 */
391void /* error */
392xfs_btree_reada_bufl(
393 struct xfs_mount *mp, /* file system mount point */
394 xfs_fsblock_t fsbno, /* file system block number */
395 xfs_extlen_t count); /* count of filesystem blocks */
396
397/*
398 * Read-ahead the block, don't wait for it, don't return a buffer.
399 * Short-form addressing.
400 */
401void /* error */
402xfs_btree_reada_bufs(
403 struct xfs_mount *mp, /* file system mount point */
404 xfs_agnumber_t agno, /* allocation group number */
405 xfs_agblock_t agbno, /* allocation group block number */
406 xfs_extlen_t count); /* count of filesystem blocks */
407
408/*
409 * Read-ahead btree blocks, at the given level.
410 * Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA.
411 */
412int /* readahead block count */
413xfs_btree_readahead_core(
414 xfs_btree_cur_t *cur, /* btree cursor */
415 int lev, /* level in btree */
416 int lr); /* left/right bits */
417
418static inline int /* readahead block count */
419xfs_btree_readahead(
420 xfs_btree_cur_t *cur, /* btree cursor */
421 int lev, /* level in btree */
422 int lr) /* left/right bits */
423{
424 if ((cur->bc_ra[lev] | lr) == cur->bc_ra[lev])
425 return 0;
426
427 return xfs_btree_readahead_core(cur, lev, lr);
428}
429
430
431/*
432 * Set the buffer for level "lev" in the cursor to bp, releasing
433 * any previous buffer.
434 */
435void
436xfs_btree_setbuf(
437 xfs_btree_cur_t *cur, /* btree cursor */
438 int lev, /* level in btree */
439 struct xfs_buf *bp); /* new buffer to set */
440
441#endif /* __KERNEL__ */
442
443
444/*
445 * Min and max functions for extlen, agblock, fileoff, and filblks types.
446 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447#define XFS_EXTLEN_MIN(a,b) \
448 ((xfs_extlen_t)(a) < (xfs_extlen_t)(b) ? \
Nathan Scotta844f452005-11-02 14:38:42 +1100449 (xfs_extlen_t)(a) : (xfs_extlen_t)(b))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450#define XFS_EXTLEN_MAX(a,b) \
451 ((xfs_extlen_t)(a) > (xfs_extlen_t)(b) ? \
Nathan Scotta844f452005-11-02 14:38:42 +1100452 (xfs_extlen_t)(a) : (xfs_extlen_t)(b))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453#define XFS_AGBLOCK_MIN(a,b) \
454 ((xfs_agblock_t)(a) < (xfs_agblock_t)(b) ? \
Nathan Scotta844f452005-11-02 14:38:42 +1100455 (xfs_agblock_t)(a) : (xfs_agblock_t)(b))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456#define XFS_AGBLOCK_MAX(a,b) \
457 ((xfs_agblock_t)(a) > (xfs_agblock_t)(b) ? \
Nathan Scotta844f452005-11-02 14:38:42 +1100458 (xfs_agblock_t)(a) : (xfs_agblock_t)(b))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459#define XFS_FILEOFF_MIN(a,b) \
460 ((xfs_fileoff_t)(a) < (xfs_fileoff_t)(b) ? \
Nathan Scotta844f452005-11-02 14:38:42 +1100461 (xfs_fileoff_t)(a) : (xfs_fileoff_t)(b))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462#define XFS_FILEOFF_MAX(a,b) \
463 ((xfs_fileoff_t)(a) > (xfs_fileoff_t)(b) ? \
Nathan Scotta844f452005-11-02 14:38:42 +1100464 (xfs_fileoff_t)(a) : (xfs_fileoff_t)(b))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465#define XFS_FILBLKS_MIN(a,b) \
466 ((xfs_filblks_t)(a) < (xfs_filblks_t)(b) ? \
Nathan Scotta844f452005-11-02 14:38:42 +1100467 (xfs_filblks_t)(a) : (xfs_filblks_t)(b))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468#define XFS_FILBLKS_MAX(a,b) \
469 ((xfs_filblks_t)(a) > (xfs_filblks_t)(b) ? \
Nathan Scotta844f452005-11-02 14:38:42 +1100470 (xfs_filblks_t)(a) : (xfs_filblks_t)(b))
471
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472#define XFS_FSB_SANITY_CHECK(mp,fsb) \
473 (XFS_FSB_TO_AGNO(mp, fsb) < mp->m_sb.sb_agcount && \
Nathan Scotta844f452005-11-02 14:38:42 +1100474 XFS_FSB_TO_AGBNO(mp, fsb) < mp->m_sb.sb_agblocks)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475
476#endif /* __XFS_BTREE_H__ */