xref: /openbmc/linux/fs/xfs/libxfs/xfs_btree.h (revision d3964221)
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_defer_ops;
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 /*
41  * The in-core btree key.  Overlapping btrees actually store two keys
42  * per pointer, so we reserve enough memory to hold both.  The __*bigkey
43  * items should never be accessed directly.
44  */
45 union xfs_btree_key {
46 	struct xfs_bmbt_key		bmbt;
47 	xfs_bmdr_key_t			bmbr;	/* bmbt root block */
48 	xfs_alloc_key_t			alloc;
49 	struct xfs_inobt_key		inobt;
50 	struct xfs_rmap_key		rmap;
51 	struct xfs_rmap_key		__rmap_bigkey[2];
52 	struct xfs_refcount_key		refc;
53 };
54 
55 union xfs_btree_rec {
56 	struct xfs_bmbt_rec		bmbt;
57 	xfs_bmdr_rec_t			bmbr;	/* bmbt root block */
58 	struct xfs_alloc_rec		alloc;
59 	struct xfs_inobt_rec		inobt;
60 	struct xfs_rmap_rec		rmap;
61 	struct xfs_refcount_rec		refc;
62 };
63 
64 /*
65  * This nonsense is to make -wlint happy.
66  */
67 #define	XFS_LOOKUP_EQ	((xfs_lookup_t)XFS_LOOKUP_EQi)
68 #define	XFS_LOOKUP_LE	((xfs_lookup_t)XFS_LOOKUP_LEi)
69 #define	XFS_LOOKUP_GE	((xfs_lookup_t)XFS_LOOKUP_GEi)
70 
71 #define	XFS_BTNUM_BNO	((xfs_btnum_t)XFS_BTNUM_BNOi)
72 #define	XFS_BTNUM_CNT	((xfs_btnum_t)XFS_BTNUM_CNTi)
73 #define	XFS_BTNUM_BMAP	((xfs_btnum_t)XFS_BTNUM_BMAPi)
74 #define	XFS_BTNUM_INO	((xfs_btnum_t)XFS_BTNUM_INOi)
75 #define	XFS_BTNUM_FINO	((xfs_btnum_t)XFS_BTNUM_FINOi)
76 #define	XFS_BTNUM_RMAP	((xfs_btnum_t)XFS_BTNUM_RMAPi)
77 #define	XFS_BTNUM_REFC	((xfs_btnum_t)XFS_BTNUM_REFCi)
78 
79 uint32_t xfs_btree_magic(int crc, xfs_btnum_t btnum);
80 
81 /*
82  * For logging record fields.
83  */
84 #define	XFS_BB_MAGIC		(1 << 0)
85 #define	XFS_BB_LEVEL		(1 << 1)
86 #define	XFS_BB_NUMRECS		(1 << 2)
87 #define	XFS_BB_LEFTSIB		(1 << 3)
88 #define	XFS_BB_RIGHTSIB		(1 << 4)
89 #define	XFS_BB_BLKNO		(1 << 5)
90 #define	XFS_BB_LSN		(1 << 6)
91 #define	XFS_BB_UUID		(1 << 7)
92 #define	XFS_BB_OWNER		(1 << 8)
93 #define	XFS_BB_NUM_BITS		5
94 #define	XFS_BB_ALL_BITS		((1 << XFS_BB_NUM_BITS) - 1)
95 #define	XFS_BB_NUM_BITS_CRC	9
96 #define	XFS_BB_ALL_BITS_CRC	((1 << XFS_BB_NUM_BITS_CRC) - 1)
97 
98 /*
99  * Generic stats interface
100  */
101 #define XFS_BTREE_STATS_INC(cur, stat)	\
102 	XFS_STATS_INC_OFF((cur)->bc_mp, (cur)->bc_statoff + __XBTS_ ## stat)
103 #define XFS_BTREE_STATS_ADD(cur, stat, val)	\
104 	XFS_STATS_ADD_OFF((cur)->bc_mp, (cur)->bc_statoff + __XBTS_ ## stat, val)
105 
106 #define	XFS_BTREE_MAXLEVELS	9	/* max of all btrees */
107 
108 struct xfs_btree_ops {
109 	/* size of the key and record structures */
110 	size_t	key_len;
111 	size_t	rec_len;
112 
113 	/* cursor operations */
114 	struct xfs_btree_cur *(*dup_cursor)(struct xfs_btree_cur *);
115 	void	(*update_cursor)(struct xfs_btree_cur *src,
116 				 struct xfs_btree_cur *dst);
117 
118 	/* update btree root pointer */
119 	void	(*set_root)(struct xfs_btree_cur *cur,
120 			    union xfs_btree_ptr *nptr, int level_change);
121 
122 	/* block allocation / freeing */
123 	int	(*alloc_block)(struct xfs_btree_cur *cur,
124 			       union xfs_btree_ptr *start_bno,
125 			       union xfs_btree_ptr *new_bno,
126 			       int *stat);
127 	int	(*free_block)(struct xfs_btree_cur *cur, struct xfs_buf *bp);
128 
129 	/* update last record information */
130 	void	(*update_lastrec)(struct xfs_btree_cur *cur,
131 				  struct xfs_btree_block *block,
132 				  union xfs_btree_rec *rec,
133 				  int ptr, int reason);
134 
135 	/* records in block/level */
136 	int	(*get_minrecs)(struct xfs_btree_cur *cur, int level);
137 	int	(*get_maxrecs)(struct xfs_btree_cur *cur, int level);
138 
139 	/* records on disk.  Matter for the root in inode case. */
140 	int	(*get_dmaxrecs)(struct xfs_btree_cur *cur, int level);
141 
142 	/* init values of btree structures */
143 	void	(*init_key_from_rec)(union xfs_btree_key *key,
144 				     union xfs_btree_rec *rec);
145 	void	(*init_rec_from_cur)(struct xfs_btree_cur *cur,
146 				     union xfs_btree_rec *rec);
147 	void	(*init_ptr_from_cur)(struct xfs_btree_cur *cur,
148 				     union xfs_btree_ptr *ptr);
149 	void	(*init_high_key_from_rec)(union xfs_btree_key *key,
150 					  union xfs_btree_rec *rec);
151 
152 	/* difference between key value and cursor value */
153 	int64_t (*key_diff)(struct xfs_btree_cur *cur,
154 			      union xfs_btree_key *key);
155 
156 	/*
157 	 * Difference between key2 and key1 -- positive if key1 > key2,
158 	 * negative if key1 < key2, and zero if equal.
159 	 */
160 	int64_t (*diff_two_keys)(struct xfs_btree_cur *cur,
161 				   union xfs_btree_key *key1,
162 				   union xfs_btree_key *key2);
163 
164 	const struct xfs_buf_ops	*buf_ops;
165 
166 	/* check that k1 is lower than k2 */
167 	int	(*keys_inorder)(struct xfs_btree_cur *cur,
168 				union xfs_btree_key *k1,
169 				union xfs_btree_key *k2);
170 
171 	/* check that r1 is lower than r2 */
172 	int	(*recs_inorder)(struct xfs_btree_cur *cur,
173 				union xfs_btree_rec *r1,
174 				union xfs_btree_rec *r2);
175 };
176 
177 /*
178  * Reasons for the update_lastrec method to be called.
179  */
180 #define LASTREC_UPDATE	0
181 #define LASTREC_INSREC	1
182 #define LASTREC_DELREC	2
183 
184 
185 union xfs_btree_irec {
186 	struct xfs_alloc_rec_incore	a;
187 	struct xfs_bmbt_irec		b;
188 	struct xfs_inobt_rec_incore	i;
189 	struct xfs_rmap_irec		r;
190 	struct xfs_refcount_irec	rc;
191 };
192 
193 /* Per-AG btree private information. */
194 union xfs_btree_cur_private {
195 	struct {
196 		unsigned long	nr_ops;		/* # record updates */
197 		int		shape_changes;	/* # of extent splits */
198 	} refc;
199 };
200 
201 /*
202  * Btree cursor structure.
203  * This collects all information needed by the btree code in one place.
204  */
205 typedef struct xfs_btree_cur
206 {
207 	struct xfs_trans	*bc_tp;	/* transaction we're in, if any */
208 	struct xfs_mount	*bc_mp;	/* file system mount struct */
209 	const struct xfs_btree_ops *bc_ops;
210 	uint			bc_flags; /* btree features - below */
211 	union xfs_btree_irec	bc_rec;	/* current insert/search record value */
212 	struct xfs_buf	*bc_bufs[XFS_BTREE_MAXLEVELS];	/* buf ptr per level */
213 	int		bc_ptrs[XFS_BTREE_MAXLEVELS];	/* key/record # */
214 	uint8_t		bc_ra[XFS_BTREE_MAXLEVELS];	/* readahead bits */
215 #define	XFS_BTCUR_LEFTRA	1	/* left sibling has been read-ahead */
216 #define	XFS_BTCUR_RIGHTRA	2	/* right sibling has been read-ahead */
217 	uint8_t		bc_nlevels;	/* number of levels in the tree */
218 	uint8_t		bc_blocklog;	/* log2(blocksize) of btree blocks */
219 	xfs_btnum_t	bc_btnum;	/* identifies which btree type */
220 	int		bc_statoff;	/* offset of btre stats array */
221 	union {
222 		struct {			/* needed for BNO, CNT, INO */
223 			struct xfs_buf	*agbp;	/* agf/agi buffer pointer */
224 			struct xfs_defer_ops *dfops;	/* deferred updates */
225 			xfs_agnumber_t	agno;	/* ag number */
226 			union xfs_btree_cur_private	priv;
227 		} a;
228 		struct {			/* needed for BMAP */
229 			struct xfs_inode *ip;	/* pointer to our inode */
230 			struct xfs_defer_ops *dfops;	/* deferred updates */
231 			xfs_fsblock_t	firstblock;	/* 1st blk allocated */
232 			int		allocated;	/* count of alloced */
233 			short		forksize;	/* fork's inode space */
234 			char		whichfork;	/* data or attr fork */
235 			char		flags;		/* flags */
236 #define	XFS_BTCUR_BPRV_WASDEL		(1<<0)		/* was delayed */
237 #define	XFS_BTCUR_BPRV_INVALID_OWNER	(1<<1)		/* for ext swap */
238 		} b;
239 	}		bc_private;	/* per-btree type data */
240 } xfs_btree_cur_t;
241 
242 /* cursor flags */
243 #define XFS_BTREE_LONG_PTRS		(1<<0)	/* pointers are 64bits long */
244 #define XFS_BTREE_ROOT_IN_INODE		(1<<1)	/* root may be variable size */
245 #define XFS_BTREE_LASTREC_UPDATE	(1<<2)	/* track last rec externally */
246 #define XFS_BTREE_CRC_BLOCKS		(1<<3)	/* uses extended btree blocks */
247 #define XFS_BTREE_OVERLAPPING		(1<<4)	/* overlapping intervals */
248 
249 
250 #define	XFS_BTREE_NOERROR	0
251 #define	XFS_BTREE_ERROR		1
252 
253 /*
254  * Convert from buffer to btree block header.
255  */
256 #define	XFS_BUF_TO_BLOCK(bp)	((struct xfs_btree_block *)((bp)->b_addr))
257 
258 
259 /*
260  * Check that block header is ok.
261  */
262 int
263 xfs_btree_check_block(
264 	struct xfs_btree_cur	*cur,	/* btree cursor */
265 	struct xfs_btree_block	*block,	/* generic btree block pointer */
266 	int			level,	/* level of the btree block */
267 	struct xfs_buf		*bp);	/* buffer containing block, if any */
268 
269 /*
270  * Check that (long) pointer is ok.
271  */
272 int					/* error (0 or EFSCORRUPTED) */
273 xfs_btree_check_lptr(
274 	struct xfs_btree_cur	*cur,	/* btree cursor */
275 	xfs_fsblock_t		ptr,	/* btree block disk address */
276 	int			level);	/* btree block level */
277 
278 /*
279  * Delete the btree cursor.
280  */
281 void
282 xfs_btree_del_cursor(
283 	xfs_btree_cur_t		*cur,	/* btree cursor */
284 	int			error);	/* del because of error */
285 
286 /*
287  * Duplicate the btree cursor.
288  * Allocate a new one, copy the record, re-get the buffers.
289  */
290 int					/* error */
291 xfs_btree_dup_cursor(
292 	xfs_btree_cur_t		*cur,	/* input cursor */
293 	xfs_btree_cur_t		**ncur);/* output cursor */
294 
295 /*
296  * Get a buffer for the block, return it with no data read.
297  * Long-form addressing.
298  */
299 struct xfs_buf *				/* buffer for fsbno */
300 xfs_btree_get_bufl(
301 	struct xfs_mount	*mp,	/* file system mount point */
302 	struct xfs_trans	*tp,	/* transaction pointer */
303 	xfs_fsblock_t		fsbno,	/* file system block number */
304 	uint			lock);	/* lock flags for get_buf */
305 
306 /*
307  * Get a buffer for the block, return it with no data read.
308  * Short-form addressing.
309  */
310 struct xfs_buf *				/* buffer for agno/agbno */
311 xfs_btree_get_bufs(
312 	struct xfs_mount	*mp,	/* file system mount point */
313 	struct xfs_trans	*tp,	/* transaction pointer */
314 	xfs_agnumber_t		agno,	/* allocation group number */
315 	xfs_agblock_t		agbno,	/* allocation group block number */
316 	uint			lock);	/* lock flags for get_buf */
317 
318 /*
319  * Check for the cursor referring to the last block at the given level.
320  */
321 int					/* 1=is last block, 0=not last block */
322 xfs_btree_islastblock(
323 	xfs_btree_cur_t		*cur,	/* btree cursor */
324 	int			level);	/* level to check */
325 
326 /*
327  * Compute first and last byte offsets for the fields given.
328  * Interprets the offsets table, which contains struct field offsets.
329  */
330 void
331 xfs_btree_offsets(
332 	int64_t			fields,	/* bitmask of fields */
333 	const short		*offsets,/* table of field offsets */
334 	int			nbits,	/* number of bits to inspect */
335 	int			*first,	/* output: first byte offset */
336 	int			*last);	/* output: last byte offset */
337 
338 /*
339  * Get a buffer for the block, return it read in.
340  * Long-form addressing.
341  */
342 int					/* error */
343 xfs_btree_read_bufl(
344 	struct xfs_mount	*mp,	/* file system mount point */
345 	struct xfs_trans	*tp,	/* transaction pointer */
346 	xfs_fsblock_t		fsbno,	/* file system block number */
347 	uint			lock,	/* lock flags for read_buf */
348 	struct xfs_buf		**bpp,	/* buffer for fsbno */
349 	int			refval,	/* ref count value for buffer */
350 	const struct xfs_buf_ops *ops);
351 
352 /*
353  * Read-ahead the block, don't wait for it, don't return a buffer.
354  * Long-form addressing.
355  */
356 void					/* error */
357 xfs_btree_reada_bufl(
358 	struct xfs_mount	*mp,	/* file system mount point */
359 	xfs_fsblock_t		fsbno,	/* file system block number */
360 	xfs_extlen_t		count,	/* count of filesystem blocks */
361 	const struct xfs_buf_ops *ops);
362 
363 /*
364  * Read-ahead the block, don't wait for it, don't return a buffer.
365  * Short-form addressing.
366  */
367 void					/* error */
368 xfs_btree_reada_bufs(
369 	struct xfs_mount	*mp,	/* file system mount point */
370 	xfs_agnumber_t		agno,	/* allocation group number */
371 	xfs_agblock_t		agbno,	/* allocation group block number */
372 	xfs_extlen_t		count,	/* count of filesystem blocks */
373 	const struct xfs_buf_ops *ops);
374 
375 /*
376  * Initialise a new btree block header
377  */
378 void
379 xfs_btree_init_block(
380 	struct xfs_mount *mp,
381 	struct xfs_buf	*bp,
382 	xfs_btnum_t	btnum,
383 	__u16		level,
384 	__u16		numrecs,
385 	__u64		owner,
386 	unsigned int	flags);
387 
388 void
389 xfs_btree_init_block_int(
390 	struct xfs_mount	*mp,
391 	struct xfs_btree_block	*buf,
392 	xfs_daddr_t		blkno,
393 	xfs_btnum_t		btnum,
394 	__u16			level,
395 	__u16			numrecs,
396 	__u64			owner,
397 	unsigned int		flags);
398 
399 /*
400  * Common btree core entry points.
401  */
402 int xfs_btree_increment(struct xfs_btree_cur *, int, int *);
403 int xfs_btree_decrement(struct xfs_btree_cur *, int, int *);
404 int xfs_btree_lookup(struct xfs_btree_cur *, xfs_lookup_t, int *);
405 int xfs_btree_update(struct xfs_btree_cur *, union xfs_btree_rec *);
406 int xfs_btree_new_iroot(struct xfs_btree_cur *, int *, int *);
407 int xfs_btree_insert(struct xfs_btree_cur *, int *);
408 int xfs_btree_delete(struct xfs_btree_cur *, int *);
409 int xfs_btree_get_rec(struct xfs_btree_cur *, union xfs_btree_rec **, int *);
410 int xfs_btree_change_owner(struct xfs_btree_cur *cur, uint64_t new_owner,
411 			   struct list_head *buffer_list);
412 
413 /*
414  * btree block CRC helpers
415  */
416 void xfs_btree_lblock_calc_crc(struct xfs_buf *);
417 bool xfs_btree_lblock_verify_crc(struct xfs_buf *);
418 void xfs_btree_sblock_calc_crc(struct xfs_buf *);
419 bool xfs_btree_sblock_verify_crc(struct xfs_buf *);
420 
421 /*
422  * Internal btree helpers also used by xfs_bmap.c.
423  */
424 void xfs_btree_log_block(struct xfs_btree_cur *, struct xfs_buf *, int);
425 void xfs_btree_log_recs(struct xfs_btree_cur *, struct xfs_buf *, int, int);
426 
427 /*
428  * Helpers.
429  */
430 static inline int xfs_btree_get_numrecs(struct xfs_btree_block *block)
431 {
432 	return be16_to_cpu(block->bb_numrecs);
433 }
434 
435 static inline void xfs_btree_set_numrecs(struct xfs_btree_block *block,
436 		uint16_t numrecs)
437 {
438 	block->bb_numrecs = cpu_to_be16(numrecs);
439 }
440 
441 static inline int xfs_btree_get_level(struct xfs_btree_block *block)
442 {
443 	return be16_to_cpu(block->bb_level);
444 }
445 
446 
447 /*
448  * Min and max functions for extlen, agblock, fileoff, and filblks types.
449  */
450 #define	XFS_EXTLEN_MIN(a,b)	min_t(xfs_extlen_t, (a), (b))
451 #define	XFS_EXTLEN_MAX(a,b)	max_t(xfs_extlen_t, (a), (b))
452 #define	XFS_AGBLOCK_MIN(a,b)	min_t(xfs_agblock_t, (a), (b))
453 #define	XFS_AGBLOCK_MAX(a,b)	max_t(xfs_agblock_t, (a), (b))
454 #define	XFS_FILEOFF_MIN(a,b)	min_t(xfs_fileoff_t, (a), (b))
455 #define	XFS_FILEOFF_MAX(a,b)	max_t(xfs_fileoff_t, (a), (b))
456 #define	XFS_FILBLKS_MIN(a,b)	min_t(xfs_filblks_t, (a), (b))
457 #define	XFS_FILBLKS_MAX(a,b)	max_t(xfs_filblks_t, (a), (b))
458 
459 #define	XFS_FSB_SANITY_CHECK(mp,fsb)	\
460 	(fsb && XFS_FSB_TO_AGNO(mp, fsb) < mp->m_sb.sb_agcount && \
461 		XFS_FSB_TO_AGBNO(mp, fsb) < mp->m_sb.sb_agblocks)
462 
463 /*
464  * Trace hooks.  Currently not implemented as they need to be ported
465  * over to the generic tracing functionality, which is some effort.
466  *
467  * i,j = integer (32 bit)
468  * b = btree block buffer (xfs_buf_t)
469  * p = btree ptr
470  * r = btree record
471  * k = btree key
472  */
473 #define	XFS_BTREE_TRACE_ARGBI(c, b, i)
474 #define	XFS_BTREE_TRACE_ARGBII(c, b, i, j)
475 #define	XFS_BTREE_TRACE_ARGI(c, i)
476 #define	XFS_BTREE_TRACE_ARGIPK(c, i, p, s)
477 #define	XFS_BTREE_TRACE_ARGIPR(c, i, p, r)
478 #define	XFS_BTREE_TRACE_ARGIK(c, i, k)
479 #define XFS_BTREE_TRACE_ARGR(c, r)
480 #define	XFS_BTREE_TRACE_CURSOR(c, t)
481 
482 bool xfs_btree_sblock_v5hdr_verify(struct xfs_buf *bp);
483 bool xfs_btree_sblock_verify(struct xfs_buf *bp, unsigned int max_recs);
484 uint xfs_btree_compute_maxlevels(struct xfs_mount *mp, uint *limits,
485 				 unsigned long len);
486 xfs_extlen_t xfs_btree_calc_size(struct xfs_mount *mp, uint *limits,
487 		unsigned long long len);
488 
489 /* return codes */
490 #define XFS_BTREE_QUERY_RANGE_CONTINUE	0	/* keep iterating */
491 #define XFS_BTREE_QUERY_RANGE_ABORT	1	/* stop iterating */
492 typedef int (*xfs_btree_query_range_fn)(struct xfs_btree_cur *cur,
493 		union xfs_btree_rec *rec, void *priv);
494 
495 int xfs_btree_query_range(struct xfs_btree_cur *cur,
496 		union xfs_btree_irec *low_rec, union xfs_btree_irec *high_rec,
497 		xfs_btree_query_range_fn fn, void *priv);
498 int xfs_btree_query_all(struct xfs_btree_cur *cur, xfs_btree_query_range_fn fn,
499 		void *priv);
500 
501 typedef int (*xfs_btree_visit_blocks_fn)(struct xfs_btree_cur *cur, int level,
502 		void *data);
503 int xfs_btree_visit_blocks(struct xfs_btree_cur *cur,
504 		xfs_btree_visit_blocks_fn fn, void *data);
505 
506 int xfs_btree_count_blocks(struct xfs_btree_cur *cur, xfs_extlen_t *blocks);
507 
508 union xfs_btree_rec *xfs_btree_rec_addr(struct xfs_btree_cur *cur, int n,
509 		struct xfs_btree_block *block);
510 union xfs_btree_key *xfs_btree_key_addr(struct xfs_btree_cur *cur, int n,
511 		struct xfs_btree_block *block);
512 union xfs_btree_key *xfs_btree_high_key_addr(struct xfs_btree_cur *cur, int n,
513 		struct xfs_btree_block *block);
514 union xfs_btree_ptr *xfs_btree_ptr_addr(struct xfs_btree_cur *cur, int n,
515 		struct xfs_btree_block *block);
516 int xfs_btree_lookup_get_block(struct xfs_btree_cur *cur, int level,
517 		union xfs_btree_ptr *pp, struct xfs_btree_block **blkp);
518 struct xfs_btree_block *xfs_btree_get_block(struct xfs_btree_cur *cur,
519 		int level, struct xfs_buf **bpp);
520 
521 #endif	/* __XFS_BTREE_H__ */
522