xref: /openbmc/linux/fs/xfs/libxfs/xfs_btree.h (revision 0883c2c0)
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  * 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 union xfs_btree_key {
41 	xfs_bmbt_key_t		bmbt;
42 	xfs_bmdr_key_t		bmbr;	/* bmbt root block */
43 	xfs_alloc_key_t		alloc;
44 	xfs_inobt_key_t		inobt;
45 };
46 
47 union xfs_btree_rec {
48 	xfs_bmbt_rec_t		bmbt;
49 	xfs_bmdr_rec_t		bmbr;	/* bmbt root block */
50 	xfs_alloc_rec_t		alloc;
51 	xfs_inobt_rec_t		inobt;
52 };
53 
54 /*
55  * This nonsense is to make -wlint happy.
56  */
57 #define	XFS_LOOKUP_EQ	((xfs_lookup_t)XFS_LOOKUP_EQi)
58 #define	XFS_LOOKUP_LE	((xfs_lookup_t)XFS_LOOKUP_LEi)
59 #define	XFS_LOOKUP_GE	((xfs_lookup_t)XFS_LOOKUP_GEi)
60 
61 #define	XFS_BTNUM_BNO	((xfs_btnum_t)XFS_BTNUM_BNOi)
62 #define	XFS_BTNUM_CNT	((xfs_btnum_t)XFS_BTNUM_CNTi)
63 #define	XFS_BTNUM_BMAP	((xfs_btnum_t)XFS_BTNUM_BMAPi)
64 #define	XFS_BTNUM_INO	((xfs_btnum_t)XFS_BTNUM_INOi)
65 #define	XFS_BTNUM_FINO	((xfs_btnum_t)XFS_BTNUM_FINOi)
66 
67 /*
68  * For logging record fields.
69  */
70 #define	XFS_BB_MAGIC		(1 << 0)
71 #define	XFS_BB_LEVEL		(1 << 1)
72 #define	XFS_BB_NUMRECS		(1 << 2)
73 #define	XFS_BB_LEFTSIB		(1 << 3)
74 #define	XFS_BB_RIGHTSIB		(1 << 4)
75 #define	XFS_BB_BLKNO		(1 << 5)
76 #define	XFS_BB_LSN		(1 << 6)
77 #define	XFS_BB_UUID		(1 << 7)
78 #define	XFS_BB_OWNER		(1 << 8)
79 #define	XFS_BB_NUM_BITS		5
80 #define	XFS_BB_ALL_BITS		((1 << XFS_BB_NUM_BITS) - 1)
81 #define	XFS_BB_NUM_BITS_CRC	9
82 #define	XFS_BB_ALL_BITS_CRC	((1 << XFS_BB_NUM_BITS_CRC) - 1)
83 
84 /*
85  * Generic stats interface
86  */
87 #define __XFS_BTREE_STATS_INC(mp, type, stat) \
88 	XFS_STATS_INC(mp, xs_ ## type ## _2_ ## stat)
89 #define XFS_BTREE_STATS_INC(cur, stat)	\
90 do {    \
91 	struct xfs_mount *__mp = cur->bc_mp; \
92 	switch (cur->bc_btnum) {  \
93 	case XFS_BTNUM_BNO: __XFS_BTREE_STATS_INC(__mp, abtb, stat); break; \
94 	case XFS_BTNUM_CNT: __XFS_BTREE_STATS_INC(__mp, abtc, stat); break; \
95 	case XFS_BTNUM_BMAP: __XFS_BTREE_STATS_INC(__mp, bmbt, stat); break; \
96 	case XFS_BTNUM_INO: __XFS_BTREE_STATS_INC(__mp, ibt, stat); break; \
97 	case XFS_BTNUM_FINO: __XFS_BTREE_STATS_INC(__mp, fibt, stat); break; \
98 	case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break;	\
99 	}       \
100 } while (0)
101 
102 #define __XFS_BTREE_STATS_ADD(mp, type, stat, val) \
103 	XFS_STATS_ADD(mp, xs_ ## type ## _2_ ## stat, val)
104 #define XFS_BTREE_STATS_ADD(cur, stat, val)  \
105 do {    \
106 	struct xfs_mount *__mp = cur->bc_mp; \
107 	switch (cur->bc_btnum) {  \
108 	case XFS_BTNUM_BNO:	\
109 		__XFS_BTREE_STATS_ADD(__mp, abtb, stat, val); break; \
110 	case XFS_BTNUM_CNT:	\
111 		__XFS_BTREE_STATS_ADD(__mp, abtc, stat, val); break; \
112 	case XFS_BTNUM_BMAP:	\
113 		__XFS_BTREE_STATS_ADD(__mp, bmbt, stat, val); break; \
114 	case XFS_BTNUM_INO:	\
115 		__XFS_BTREE_STATS_ADD(__mp, ibt, stat, val); break; \
116 	case XFS_BTNUM_FINO:	\
117 		__XFS_BTREE_STATS_ADD(__mp, fibt, stat, val); break; \
118 	case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break; \
119 	}       \
120 } while (0)
121 
122 #define	XFS_BTREE_MAXLEVELS	8	/* max of all btrees */
123 
124 struct xfs_btree_ops {
125 	/* size of the key and record structures */
126 	size_t	key_len;
127 	size_t	rec_len;
128 
129 	/* cursor operations */
130 	struct xfs_btree_cur *(*dup_cursor)(struct xfs_btree_cur *);
131 	void	(*update_cursor)(struct xfs_btree_cur *src,
132 				 struct xfs_btree_cur *dst);
133 
134 	/* update btree root pointer */
135 	void	(*set_root)(struct xfs_btree_cur *cur,
136 			    union xfs_btree_ptr *nptr, int level_change);
137 
138 	/* block allocation / freeing */
139 	int	(*alloc_block)(struct xfs_btree_cur *cur,
140 			       union xfs_btree_ptr *start_bno,
141 			       union xfs_btree_ptr *new_bno,
142 			       int *stat);
143 	int	(*free_block)(struct xfs_btree_cur *cur, struct xfs_buf *bp);
144 
145 	/* update last record information */
146 	void	(*update_lastrec)(struct xfs_btree_cur *cur,
147 				  struct xfs_btree_block *block,
148 				  union xfs_btree_rec *rec,
149 				  int ptr, int reason);
150 
151 	/* records in block/level */
152 	int	(*get_minrecs)(struct xfs_btree_cur *cur, int level);
153 	int	(*get_maxrecs)(struct xfs_btree_cur *cur, int level);
154 
155 	/* records on disk.  Matter for the root in inode case. */
156 	int	(*get_dmaxrecs)(struct xfs_btree_cur *cur, int level);
157 
158 	/* init values of btree structures */
159 	void	(*init_key_from_rec)(union xfs_btree_key *key,
160 				     union xfs_btree_rec *rec);
161 	void	(*init_rec_from_key)(union xfs_btree_key *key,
162 				     union xfs_btree_rec *rec);
163 	void	(*init_rec_from_cur)(struct xfs_btree_cur *cur,
164 				     union xfs_btree_rec *rec);
165 	void	(*init_ptr_from_cur)(struct xfs_btree_cur *cur,
166 				     union xfs_btree_ptr *ptr);
167 
168 	/* difference between key value and cursor value */
169 	__int64_t (*key_diff)(struct xfs_btree_cur *cur,
170 			      union xfs_btree_key *key);
171 
172 	const struct xfs_buf_ops	*buf_ops;
173 
174 #if defined(DEBUG) || defined(XFS_WARN)
175 	/* check that k1 is lower than k2 */
176 	int	(*keys_inorder)(struct xfs_btree_cur *cur,
177 				union xfs_btree_key *k1,
178 				union xfs_btree_key *k2);
179 
180 	/* check that r1 is lower than r2 */
181 	int	(*recs_inorder)(struct xfs_btree_cur *cur,
182 				union xfs_btree_rec *r1,
183 				union xfs_btree_rec *r2);
184 #endif
185 };
186 
187 /*
188  * Reasons for the update_lastrec method to be called.
189  */
190 #define LASTREC_UPDATE	0
191 #define LASTREC_INSREC	1
192 #define LASTREC_DELREC	2
193 
194 
195 /*
196  * Btree cursor structure.
197  * This collects all information needed by the btree code in one place.
198  */
199 typedef struct xfs_btree_cur
200 {
201 	struct xfs_trans	*bc_tp;	/* transaction we're in, if any */
202 	struct xfs_mount	*bc_mp;	/* file system mount struct */
203 	const struct xfs_btree_ops *bc_ops;
204 	uint			bc_flags; /* btree features - below */
205 	union {
206 		xfs_alloc_rec_incore_t	a;
207 		xfs_bmbt_irec_t		b;
208 		xfs_inobt_rec_incore_t	i;
209 	}		bc_rec;		/* current insert/search record value */
210 	struct xfs_buf	*bc_bufs[XFS_BTREE_MAXLEVELS];	/* buf ptr per level */
211 	int		bc_ptrs[XFS_BTREE_MAXLEVELS];	/* key/record # */
212 	__uint8_t	bc_ra[XFS_BTREE_MAXLEVELS];	/* readahead bits */
213 #define	XFS_BTCUR_LEFTRA	1	/* left sibling has been read-ahead */
214 #define	XFS_BTCUR_RIGHTRA	2	/* right sibling has been read-ahead */
215 	__uint8_t	bc_nlevels;	/* number of levels in the tree */
216 	__uint8_t	bc_blocklog;	/* log2(blocksize) of btree blocks */
217 	xfs_btnum_t	bc_btnum;	/* identifies which btree type */
218 	union {
219 		struct {			/* needed for BNO, CNT, INO */
220 			struct xfs_buf	*agbp;	/* agf/agi buffer pointer */
221 			xfs_agnumber_t	agno;	/* ag number */
222 		} a;
223 		struct {			/* needed for BMAP */
224 			struct xfs_inode *ip;	/* pointer to our inode */
225 			struct xfs_bmap_free *flist;	/* list to free after */
226 			xfs_fsblock_t	firstblock;	/* 1st blk allocated */
227 			int		allocated;	/* count of alloced */
228 			short		forksize;	/* fork's inode space */
229 			char		whichfork;	/* data or attr fork */
230 			char		flags;		/* flags */
231 #define	XFS_BTCUR_BPRV_WASDEL	1			/* was delayed */
232 		} b;
233 	}		bc_private;	/* per-btree type data */
234 } xfs_btree_cur_t;
235 
236 /* cursor flags */
237 #define XFS_BTREE_LONG_PTRS		(1<<0)	/* pointers are 64bits long */
238 #define XFS_BTREE_ROOT_IN_INODE		(1<<1)	/* root may be variable size */
239 #define XFS_BTREE_LASTREC_UPDATE	(1<<2)	/* track last rec externally */
240 #define XFS_BTREE_CRC_BLOCKS		(1<<3)	/* uses extended btree blocks */
241 
242 
243 #define	XFS_BTREE_NOERROR	0
244 #define	XFS_BTREE_ERROR		1
245 
246 /*
247  * Convert from buffer to btree block header.
248  */
249 #define	XFS_BUF_TO_BLOCK(bp)	((struct xfs_btree_block *)((bp)->b_addr))
250 
251 
252 /*
253  * Check that block header is ok.
254  */
255 int
256 xfs_btree_check_block(
257 	struct xfs_btree_cur	*cur,	/* btree cursor */
258 	struct xfs_btree_block	*block,	/* generic btree block pointer */
259 	int			level,	/* level of the btree block */
260 	struct xfs_buf		*bp);	/* buffer containing block, if any */
261 
262 /*
263  * Check that (long) pointer is ok.
264  */
265 int					/* error (0 or EFSCORRUPTED) */
266 xfs_btree_check_lptr(
267 	struct xfs_btree_cur	*cur,	/* btree cursor */
268 	xfs_fsblock_t		ptr,	/* btree block disk address */
269 	int			level);	/* btree block level */
270 
271 /*
272  * Delete the btree cursor.
273  */
274 void
275 xfs_btree_del_cursor(
276 	xfs_btree_cur_t		*cur,	/* btree cursor */
277 	int			error);	/* del because of error */
278 
279 /*
280  * Duplicate the btree cursor.
281  * Allocate a new one, copy the record, re-get the buffers.
282  */
283 int					/* error */
284 xfs_btree_dup_cursor(
285 	xfs_btree_cur_t		*cur,	/* input cursor */
286 	xfs_btree_cur_t		**ncur);/* output cursor */
287 
288 /*
289  * Get a buffer for the block, return it with no data read.
290  * Long-form addressing.
291  */
292 struct xfs_buf *				/* buffer for fsbno */
293 xfs_btree_get_bufl(
294 	struct xfs_mount	*mp,	/* file system mount point */
295 	struct xfs_trans	*tp,	/* transaction pointer */
296 	xfs_fsblock_t		fsbno,	/* file system block number */
297 	uint			lock);	/* lock flags for get_buf */
298 
299 /*
300  * Get a buffer for the block, return it with no data read.
301  * Short-form addressing.
302  */
303 struct xfs_buf *				/* buffer for agno/agbno */
304 xfs_btree_get_bufs(
305 	struct xfs_mount	*mp,	/* file system mount point */
306 	struct xfs_trans	*tp,	/* transaction pointer */
307 	xfs_agnumber_t		agno,	/* allocation group number */
308 	xfs_agblock_t		agbno,	/* allocation group block number */
309 	uint			lock);	/* lock flags for get_buf */
310 
311 /*
312  * Check for the cursor referring to the last block at the given level.
313  */
314 int					/* 1=is last block, 0=not last block */
315 xfs_btree_islastblock(
316 	xfs_btree_cur_t		*cur,	/* btree cursor */
317 	int			level);	/* level to check */
318 
319 /*
320  * Compute first and last byte offsets for the fields given.
321  * Interprets the offsets table, which contains struct field offsets.
322  */
323 void
324 xfs_btree_offsets(
325 	__int64_t		fields,	/* bitmask of fields */
326 	const short		*offsets,/* table of field offsets */
327 	int			nbits,	/* number of bits to inspect */
328 	int			*first,	/* output: first byte offset */
329 	int			*last);	/* output: last byte offset */
330 
331 /*
332  * Get a buffer for the block, return it read in.
333  * Long-form addressing.
334  */
335 int					/* error */
336 xfs_btree_read_bufl(
337 	struct xfs_mount	*mp,	/* file system mount point */
338 	struct xfs_trans	*tp,	/* transaction pointer */
339 	xfs_fsblock_t		fsbno,	/* file system block number */
340 	uint			lock,	/* lock flags for read_buf */
341 	struct xfs_buf		**bpp,	/* buffer for fsbno */
342 	int			refval,	/* ref count value for buffer */
343 	const struct xfs_buf_ops *ops);
344 
345 /*
346  * Read-ahead the block, don't wait for it, don't return a buffer.
347  * Long-form addressing.
348  */
349 void					/* error */
350 xfs_btree_reada_bufl(
351 	struct xfs_mount	*mp,	/* file system mount point */
352 	xfs_fsblock_t		fsbno,	/* file system block number */
353 	xfs_extlen_t		count,	/* count of filesystem blocks */
354 	const struct xfs_buf_ops *ops);
355 
356 /*
357  * Read-ahead the block, don't wait for it, don't return a buffer.
358  * Short-form addressing.
359  */
360 void					/* error */
361 xfs_btree_reada_bufs(
362 	struct xfs_mount	*mp,	/* file system mount point */
363 	xfs_agnumber_t		agno,	/* allocation group number */
364 	xfs_agblock_t		agbno,	/* allocation group block number */
365 	xfs_extlen_t		count,	/* count of filesystem blocks */
366 	const struct xfs_buf_ops *ops);
367 
368 /*
369  * Initialise a new btree block header
370  */
371 void
372 xfs_btree_init_block(
373 	struct xfs_mount *mp,
374 	struct xfs_buf	*bp,
375 	__u32		magic,
376 	__u16		level,
377 	__u16		numrecs,
378 	__u64		owner,
379 	unsigned int	flags);
380 
381 void
382 xfs_btree_init_block_int(
383 	struct xfs_mount	*mp,
384 	struct xfs_btree_block	*buf,
385 	xfs_daddr_t		blkno,
386 	__u32			magic,
387 	__u16			level,
388 	__u16			numrecs,
389 	__u64			owner,
390 	unsigned int		flags);
391 
392 /*
393  * Common btree core entry points.
394  */
395 int xfs_btree_increment(struct xfs_btree_cur *, int, int *);
396 int xfs_btree_decrement(struct xfs_btree_cur *, int, int *);
397 int xfs_btree_lookup(struct xfs_btree_cur *, xfs_lookup_t, int *);
398 int xfs_btree_update(struct xfs_btree_cur *, union xfs_btree_rec *);
399 int xfs_btree_new_iroot(struct xfs_btree_cur *, int *, int *);
400 int xfs_btree_insert(struct xfs_btree_cur *, int *);
401 int xfs_btree_delete(struct xfs_btree_cur *, int *);
402 int xfs_btree_get_rec(struct xfs_btree_cur *, union xfs_btree_rec **, int *);
403 int xfs_btree_change_owner(struct xfs_btree_cur *cur, __uint64_t new_owner,
404 			   struct list_head *buffer_list);
405 
406 /*
407  * btree block CRC helpers
408  */
409 void xfs_btree_lblock_calc_crc(struct xfs_buf *);
410 bool xfs_btree_lblock_verify_crc(struct xfs_buf *);
411 void xfs_btree_sblock_calc_crc(struct xfs_buf *);
412 bool xfs_btree_sblock_verify_crc(struct xfs_buf *);
413 
414 /*
415  * Internal btree helpers also used by xfs_bmap.c.
416  */
417 void xfs_btree_log_block(struct xfs_btree_cur *, struct xfs_buf *, int);
418 void xfs_btree_log_recs(struct xfs_btree_cur *, struct xfs_buf *, int, int);
419 
420 /*
421  * Helpers.
422  */
423 static inline int xfs_btree_get_numrecs(struct xfs_btree_block *block)
424 {
425 	return be16_to_cpu(block->bb_numrecs);
426 }
427 
428 static inline void xfs_btree_set_numrecs(struct xfs_btree_block *block,
429 		__uint16_t numrecs)
430 {
431 	block->bb_numrecs = cpu_to_be16(numrecs);
432 }
433 
434 static inline int xfs_btree_get_level(struct xfs_btree_block *block)
435 {
436 	return be16_to_cpu(block->bb_level);
437 }
438 
439 
440 /*
441  * Min and max functions for extlen, agblock, fileoff, and filblks types.
442  */
443 #define	XFS_EXTLEN_MIN(a,b)	min_t(xfs_extlen_t, (a), (b))
444 #define	XFS_EXTLEN_MAX(a,b)	max_t(xfs_extlen_t, (a), (b))
445 #define	XFS_AGBLOCK_MIN(a,b)	min_t(xfs_agblock_t, (a), (b))
446 #define	XFS_AGBLOCK_MAX(a,b)	max_t(xfs_agblock_t, (a), (b))
447 #define	XFS_FILEOFF_MIN(a,b)	min_t(xfs_fileoff_t, (a), (b))
448 #define	XFS_FILEOFF_MAX(a,b)	max_t(xfs_fileoff_t, (a), (b))
449 #define	XFS_FILBLKS_MIN(a,b)	min_t(xfs_filblks_t, (a), (b))
450 #define	XFS_FILBLKS_MAX(a,b)	max_t(xfs_filblks_t, (a), (b))
451 
452 #define	XFS_FSB_SANITY_CHECK(mp,fsb)	\
453 	(XFS_FSB_TO_AGNO(mp, fsb) < mp->m_sb.sb_agcount && \
454 		XFS_FSB_TO_AGBNO(mp, fsb) < mp->m_sb.sb_agblocks)
455 
456 /*
457  * Trace hooks.  Currently not implemented as they need to be ported
458  * over to the generic tracing functionality, which is some effort.
459  *
460  * i,j = integer (32 bit)
461  * b = btree block buffer (xfs_buf_t)
462  * p = btree ptr
463  * r = btree record
464  * k = btree key
465  */
466 #define	XFS_BTREE_TRACE_ARGBI(c, b, i)
467 #define	XFS_BTREE_TRACE_ARGBII(c, b, i, j)
468 #define	XFS_BTREE_TRACE_ARGI(c, i)
469 #define	XFS_BTREE_TRACE_ARGIPK(c, i, p, s)
470 #define	XFS_BTREE_TRACE_ARGIPR(c, i, p, r)
471 #define	XFS_BTREE_TRACE_ARGIK(c, i, k)
472 #define XFS_BTREE_TRACE_ARGR(c, r)
473 #define	XFS_BTREE_TRACE_CURSOR(c, t)
474 
475 bool xfs_btree_sblock_v5hdr_verify(struct xfs_buf *bp);
476 bool xfs_btree_sblock_verify(struct xfs_buf *bp, unsigned int max_recs);
477 
478 #endif	/* __XFS_BTREE_H__ */
479