Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
/*
 * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#ifndef __XFS_BTREE_H__
#define	__XFS_BTREE_H__

struct xfs_buf;
struct xfs_bmap_free;
struct xfs_inode;
struct xfs_mount;
struct xfs_trans;

extern kmem_zone_t	*xfs_btree_cur_zone;

/*
 * This nonsense is to make -wlint happy.
 */
#define	XFS_LOOKUP_EQ	((xfs_lookup_t)XFS_LOOKUP_EQi)
#define	XFS_LOOKUP_LE	((xfs_lookup_t)XFS_LOOKUP_LEi)
#define	XFS_LOOKUP_GE	((xfs_lookup_t)XFS_LOOKUP_GEi)

#define	XFS_BTNUM_BNO	((xfs_btnum_t)XFS_BTNUM_BNOi)
#define	XFS_BTNUM_CNT	((xfs_btnum_t)XFS_BTNUM_CNTi)
#define	XFS_BTNUM_BMAP	((xfs_btnum_t)XFS_BTNUM_BMAPi)
#define	XFS_BTNUM_INO	((xfs_btnum_t)XFS_BTNUM_INOi)

/*
 * Generic btree header.
 *
 * This is a combination of the actual format used on disk for short and long
 * format btrees.  The first three fields are shared by both format, but the
 * pointers are different and should be used with care.
 *
 * To get the size of the actual short or long form headers please use the size
 * macros below.  Never use sizeof(xfs_btree_block).
 *
 * The blkno, crc, lsn, owner and uuid fields are only available in filesystems
 * with the crc feature bit, and all accesses to them must be conditional on
 * that flag.
 */
struct xfs_btree_block {
	__be32		bb_magic;	/* magic number for block type */
	__be16		bb_level;	/* 0 is a leaf */
	__be16		bb_numrecs;	/* current # of data records */
	union {
		struct {
			__be32		bb_leftsib;
			__be32		bb_rightsib;

			__be64		bb_blkno;
			__be64		bb_lsn;
			uuid_t		bb_uuid;
			__be32		bb_owner;
			__le32		bb_crc;
		} s;			/* short form pointers */
		struct	{
			__be64		bb_leftsib;
			__be64		bb_rightsib;

			__be64		bb_blkno;
			__be64		bb_lsn;
			uuid_t		bb_uuid;
			__be64		bb_owner;
			__le32		bb_crc;
			__be32		bb_pad; /* padding for alignment */
		} l;			/* long form pointers */
	} bb_u;				/* rest */
};

#define XFS_BTREE_SBLOCK_LEN	16	/* size of a short form block */
#define XFS_BTREE_LBLOCK_LEN	24	/* size of a long form block */

/* sizes of CRC enabled btree blocks */
#define XFS_BTREE_SBLOCK_CRC_LEN	(XFS_BTREE_SBLOCK_LEN + 40)
#define XFS_BTREE_LBLOCK_CRC_LEN	(XFS_BTREE_LBLOCK_LEN + 48)


#define XFS_BTREE_SBLOCK_CRC_OFF \
	offsetof(struct xfs_btree_block, bb_u.s.bb_crc)
#define XFS_BTREE_LBLOCK_CRC_OFF \
	offsetof(struct xfs_btree_block, bb_u.l.bb_crc)


/*
 * Generic key, ptr and record wrapper structures.
 *
 * These are disk format structures, and are converted where necessary
 * by the btree specific code that needs to interpret them.
 */
union xfs_btree_ptr {
	__be32			s;	/* short form ptr */
	__be64			l;	/* long form ptr */
};

union xfs_btree_key {
	xfs_bmbt_key_t		bmbt;
	xfs_bmdr_key_t		bmbr;	/* bmbt root block */
	xfs_alloc_key_t		alloc;
	xfs_inobt_key_t		inobt;
};

union xfs_btree_rec {
	xfs_bmbt_rec_t		bmbt;
	xfs_bmdr_rec_t		bmbr;	/* bmbt root block */
	xfs_alloc_rec_t		alloc;
	xfs_inobt_rec_t		inobt;
};

/*
 * For logging record fields.
 */
#define	XFS_BB_MAGIC		0x01
#define	XFS_BB_LEVEL		0x02
#define	XFS_BB_NUMRECS		0x04
#define	XFS_BB_LEFTSIB		0x08
#define	XFS_BB_RIGHTSIB		0x10
#define	XFS_BB_BLKNO		0x20
#define	XFS_BB_NUM_BITS		5
#define	XFS_BB_ALL_BITS		((1 << XFS_BB_NUM_BITS) - 1)
#define	XFS_BB_NUM_BITS_CRC	8
#define	XFS_BB_ALL_BITS_CRC	((1 << XFS_BB_NUM_BITS_CRC) - 1)

/*
 * Generic stats interface
 */
#define __XFS_BTREE_STATS_INC(type, stat) \
	XFS_STATS_INC(xs_ ## type ## _2_ ## stat)
#define XFS_BTREE_STATS_INC(cur, stat)  \
do {    \
	switch (cur->bc_btnum) {  \
	case XFS_BTNUM_BNO: __XFS_BTREE_STATS_INC(abtb, stat); break;	\
	case XFS_BTNUM_CNT: __XFS_BTREE_STATS_INC(abtc, stat); break;	\
	case XFS_BTNUM_BMAP: __XFS_BTREE_STATS_INC(bmbt, stat); break;	\
	case XFS_BTNUM_INO: __XFS_BTREE_STATS_INC(ibt, stat); break;	\
	case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break;	\
	}       \
} while (0)

#define __XFS_BTREE_STATS_ADD(type, stat, val) \
	XFS_STATS_ADD(xs_ ## type ## _2_ ## stat, val)
#define XFS_BTREE_STATS_ADD(cur, stat, val)  \
do {    \
	switch (cur->bc_btnum) {  \
	case XFS_BTNUM_BNO: __XFS_BTREE_STATS_ADD(abtb, stat, val); break; \
	case XFS_BTNUM_CNT: __XFS_BTREE_STATS_ADD(abtc, stat, val); break; \
	case XFS_BTNUM_BMAP: __XFS_BTREE_STATS_ADD(bmbt, stat, val); break; \
	case XFS_BTNUM_INO: __XFS_BTREE_STATS_ADD(ibt, stat, val); break; \
	case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break;	\
	}       \
} while (0)

#define	XFS_BTREE_MAXLEVELS	8	/* max of all btrees */

struct xfs_btree_ops {
	/* size of the key and record structures */
	size_t	key_len;
	size_t	rec_len;

	/* cursor operations */
	struct xfs_btree_cur *(*dup_cursor)(struct xfs_btree_cur *);
	void	(*update_cursor)(struct xfs_btree_cur *src,
				 struct xfs_btree_cur *dst);

	/* update btree root pointer */
	void	(*set_root)(struct xfs_btree_cur *cur,
			    union xfs_btree_ptr *nptr, int level_change);

	/* block allocation / freeing */
	int	(*alloc_block)(struct xfs_btree_cur *cur,
			       union xfs_btree_ptr *start_bno,
			       union xfs_btree_ptr *new_bno,
			       int length, int *stat);
	int	(*free_block)(struct xfs_btree_cur *cur, struct xfs_buf *bp);

	/* update last record information */
	void	(*update_lastrec)(struct xfs_btree_cur *cur,
				  struct xfs_btree_block *block,
				  union xfs_btree_rec *rec,
				  int ptr, int reason);

	/* records in block/level */
	int	(*get_minrecs)(struct xfs_btree_cur *cur, int level);
	int	(*get_maxrecs)(struct xfs_btree_cur *cur, int level);

	/* records on disk.  Matter for the root in inode case. */
	int	(*get_dmaxrecs)(struct xfs_btree_cur *cur, int level);

	/* init values of btree structures */
	void	(*init_key_from_rec)(union xfs_btree_key *key,
				     union xfs_btree_rec *rec);
	void	(*init_rec_from_key)(union xfs_btree_key *key,
				     union xfs_btree_rec *rec);
	void	(*init_rec_from_cur)(struct xfs_btree_cur *cur,
				     union xfs_btree_rec *rec);
	void	(*init_ptr_from_cur)(struct xfs_btree_cur *cur,
				     union xfs_btree_ptr *ptr);

	/* difference between key value and cursor value */
	__int64_t (*key_diff)(struct xfs_btree_cur *cur,
			      union xfs_btree_key *key);

	const struct xfs_buf_ops	*buf_ops;

#if defined(DEBUG) || defined(XFS_WARN)
	/* check that k1 is lower than k2 */
	int	(*keys_inorder)(struct xfs_btree_cur *cur,
				union xfs_btree_key *k1,
				union xfs_btree_key *k2);

	/* check that r1 is lower than r2 */
	int	(*recs_inorder)(struct xfs_btree_cur *cur,
				union xfs_btree_rec *r1,
				union xfs_btree_rec *r2);
#endif
};

/*
 * Reasons for the update_lastrec method to be called.
 */
#define LASTREC_UPDATE	0
#define LASTREC_INSREC	1
#define LASTREC_DELREC	2


/*
 * Btree cursor structure.
 * This collects all information needed by the btree code in one place.
 */
typedef struct xfs_btree_cur
{
	struct xfs_trans	*bc_tp;	/* transaction we're in, if any */
	struct xfs_mount	*bc_mp;	/* file system mount struct */
	const struct xfs_btree_ops *bc_ops;
	uint			bc_flags; /* btree features - below */
	union {
		xfs_alloc_rec_incore_t	a;
		xfs_bmbt_irec_t		b;
		xfs_inobt_rec_incore_t	i;
	}		bc_rec;		/* current insert/search record value */
	struct xfs_buf	*bc_bufs[XFS_BTREE_MAXLEVELS];	/* buf ptr per level */
	int		bc_ptrs[XFS_BTREE_MAXLEVELS];	/* key/record # */
	__uint8_t	bc_ra[XFS_BTREE_MAXLEVELS];	/* readahead bits */
#define	XFS_BTCUR_LEFTRA	1	/* left sibling has been read-ahead */
#define	XFS_BTCUR_RIGHTRA	2	/* right sibling has been read-ahead */
	__uint8_t	bc_nlevels;	/* number of levels in the tree */
	__uint8_t	bc_blocklog;	/* log2(blocksize) of btree blocks */
	xfs_btnum_t	bc_btnum;	/* identifies which btree type */
	union {
		struct {			/* needed for BNO, CNT, INO */
			struct xfs_buf	*agbp;	/* agf/agi buffer pointer */
			xfs_agnumber_t	agno;	/* ag number */
		} a;
		struct {			/* needed for BMAP */
			struct xfs_inode *ip;	/* pointer to our inode */
			struct xfs_bmap_free *flist;	/* list to free after */
			xfs_fsblock_t	firstblock;	/* 1st blk allocated */
			int		allocated;	/* count of alloced */
			short		forksize;	/* fork's inode space */
			char		whichfork;	/* data or attr fork */
			char		flags;		/* flags */
#define	XFS_BTCUR_BPRV_WASDEL	1			/* was delayed */
		} b;
	}		bc_private;	/* per-btree type data */
} xfs_btree_cur_t;

/* cursor flags */
#define XFS_BTREE_LONG_PTRS		(1<<0)	/* pointers are 64bits long */
#define XFS_BTREE_ROOT_IN_INODE		(1<<1)	/* root may be variable size */
#define XFS_BTREE_LASTREC_UPDATE	(1<<2)	/* track last rec externally */
#define XFS_BTREE_CRC_BLOCKS		(1<<3)	/* uses extended btree blocks */


#define	XFS_BTREE_NOERROR	0
#define	XFS_BTREE_ERROR		1

/*
 * Convert from buffer to btree block header.
 */
#define	XFS_BUF_TO_BLOCK(bp)	((struct xfs_btree_block *)((bp)->b_addr))


/*
 * Check that block header is ok.
 */
int
xfs_btree_check_block(
	struct xfs_btree_cur	*cur,	/* btree cursor */
	struct xfs_btree_block	*block,	/* generic btree block pointer */
	int			level,	/* level of the btree block */
	struct xfs_buf		*bp);	/* buffer containing block, if any */

/*
 * Check that (long) pointer is ok.
 */
int					/* error (0 or EFSCORRUPTED) */
xfs_btree_check_lptr(
	struct xfs_btree_cur	*cur,	/* btree cursor */
	xfs_dfsbno_t		ptr,	/* btree block disk address */
	int			level);	/* btree block level */

/*
 * Delete the btree cursor.
 */
void
xfs_btree_del_cursor(
	xfs_btree_cur_t		*cur,	/* btree cursor */
	int			error);	/* del because of error */

/*
 * Duplicate the btree cursor.
 * Allocate a new one, copy the record, re-get the buffers.
 */
int					/* error */
xfs_btree_dup_cursor(
	xfs_btree_cur_t		*cur,	/* input cursor */
	xfs_btree_cur_t		**ncur);/* output cursor */

/*
 * Get a buffer for the block, return it with no data read.
 * Long-form addressing.
 */
struct xfs_buf *				/* buffer for fsbno */
xfs_btree_get_bufl(
	struct xfs_mount	*mp,	/* file system mount point */
	struct xfs_trans	*tp,	/* transaction pointer */
	xfs_fsblock_t		fsbno,	/* file system block number */
	uint			lock);	/* lock flags for get_buf */

/*
 * Get a buffer for the block, return it with no data read.
 * Short-form addressing.
 */
struct xfs_buf *				/* buffer for agno/agbno */
xfs_btree_get_bufs(
	struct xfs_mount	*mp,	/* file system mount point */
	struct xfs_trans	*tp,	/* transaction pointer */
	xfs_agnumber_t		agno,	/* allocation group number */
	xfs_agblock_t		agbno,	/* allocation group block number */
	uint			lock);	/* lock flags for get_buf */

/*
 * Check for the cursor referring to the last block at the given level.
 */
int					/* 1=is last block, 0=not last block */
xfs_btree_islastblock(
	xfs_btree_cur_t		*cur,	/* btree cursor */
	int			level);	/* level to check */

/*
 * Compute first and last byte offsets for the fields given.
 * Interprets the offsets table, which contains struct field offsets.
 */
void
xfs_btree_offsets(
	__int64_t		fields,	/* bitmask of fields */
	const short		*offsets,/* table of field offsets */
	int			nbits,	/* number of bits to inspect */
	int			*first,	/* output: first byte offset */
	int			*last);	/* output: last byte offset */

/*
 * Get a buffer for the block, return it read in.
 * Long-form addressing.
 */
int					/* error */
xfs_btree_read_bufl(
	struct xfs_mount	*mp,	/* file system mount point */
	struct xfs_trans	*tp,	/* transaction pointer */
	xfs_fsblock_t		fsbno,	/* file system block number */
	uint			lock,	/* lock flags for read_buf */
	struct xfs_buf		**bpp,	/* buffer for fsbno */
	int			refval,	/* ref count value for buffer */
	const struct xfs_buf_ops *ops);

/*
 * Read-ahead the block, don't wait for it, don't return a buffer.
 * Long-form addressing.
 */
void					/* error */
xfs_btree_reada_bufl(
	struct xfs_mount	*mp,	/* file system mount point */
	xfs_fsblock_t		fsbno,	/* file system block number */
	xfs_extlen_t		count,	/* count of filesystem blocks */
	const struct xfs_buf_ops *ops);

/*
 * Read-ahead the block, don't wait for it, don't return a buffer.
 * Short-form addressing.
 */
void					/* error */
xfs_btree_reada_bufs(
	struct xfs_mount	*mp,	/* file system mount point */
	xfs_agnumber_t		agno,	/* allocation group number */
	xfs_agblock_t		agbno,	/* allocation group block number */
	xfs_extlen_t		count,	/* count of filesystem blocks */
	const struct xfs_buf_ops *ops);

/*
 * Initialise a new btree block header
 */
void
xfs_btree_init_block(
	struct xfs_mount *mp,
	struct xfs_buf	*bp,
	__u32		magic,
	__u16		level,
	__u16		numrecs,
	__u64		owner,
	unsigned int	flags);

void
xfs_btree_init_block_int(
	struct xfs_mount	*mp,
	struct xfs_btree_block	*buf,
	xfs_daddr_t		blkno,
	__u32			magic,
	__u16			level,
	__u16			numrecs,
	__u64			owner,
	unsigned int		flags);

/*
 * Common btree core entry points.
 */
int xfs_btree_increment(struct xfs_btree_cur *, int, int *);
int xfs_btree_decrement(struct xfs_btree_cur *, int, int *);
int xfs_btree_lookup(struct xfs_btree_cur *, xfs_lookup_t, int *);
int xfs_btree_update(struct xfs_btree_cur *, union xfs_btree_rec *);
int xfs_btree_new_iroot(struct xfs_btree_cur *, int *, int *);
int xfs_btree_insert(struct xfs_btree_cur *, int *);
int xfs_btree_delete(struct xfs_btree_cur *, int *);
int xfs_btree_get_rec(struct xfs_btree_cur *, union xfs_btree_rec **, int *);

/*
 * btree block CRC helpers
 */
void xfs_btree_lblock_calc_crc(struct xfs_buf *);
bool xfs_btree_lblock_verify_crc(struct xfs_buf *);
void xfs_btree_sblock_calc_crc(struct xfs_buf *);
bool xfs_btree_sblock_verify_crc(struct xfs_buf *);

/*
 * Internal btree helpers also used by xfs_bmap.c.
 */
void xfs_btree_log_block(struct xfs_btree_cur *, struct xfs_buf *, int);
void xfs_btree_log_recs(struct xfs_btree_cur *, struct xfs_buf *, int, int);

/*
 * Helpers.
 */
static inline int xfs_btree_get_numrecs(struct xfs_btree_block *block)
{
	return be16_to_cpu(block->bb_numrecs);
}

static inline void xfs_btree_set_numrecs(struct xfs_btree_block *block,
		__uint16_t numrecs)
{
	block->bb_numrecs = cpu_to_be16(numrecs);
}

static inline int xfs_btree_get_level(struct xfs_btree_block *block)
{
	return be16_to_cpu(block->bb_level);
}


/*
 * Min and max functions for extlen, agblock, fileoff, and filblks types.
 */
#define	XFS_EXTLEN_MIN(a,b)	min_t(xfs_extlen_t, (a), (b))
#define	XFS_EXTLEN_MAX(a,b)	max_t(xfs_extlen_t, (a), (b))
#define	XFS_AGBLOCK_MIN(a,b)	min_t(xfs_agblock_t, (a), (b))
#define	XFS_AGBLOCK_MAX(a,b)	max_t(xfs_agblock_t, (a), (b))
#define	XFS_FILEOFF_MIN(a,b)	min_t(xfs_fileoff_t, (a), (b))
#define	XFS_FILEOFF_MAX(a,b)	max_t(xfs_fileoff_t, (a), (b))
#define	XFS_FILBLKS_MIN(a,b)	min_t(xfs_filblks_t, (a), (b))
#define	XFS_FILBLKS_MAX(a,b)	max_t(xfs_filblks_t, (a), (b))

#define	XFS_FSB_SANITY_CHECK(mp,fsb)	\
	(XFS_FSB_TO_AGNO(mp, fsb) < mp->m_sb.sb_agcount && \
		XFS_FSB_TO_AGBNO(mp, fsb) < mp->m_sb.sb_agblocks)

/*
 * Trace hooks.  Currently not implemented as they need to be ported
 * over to the generic tracing functionality, which is some effort.
 *
 * i,j = integer (32 bit)
 * b = btree block buffer (xfs_buf_t)
 * p = btree ptr
 * r = btree record
 * k = btree key
 */
#define	XFS_BTREE_TRACE_ARGBI(c, b, i)
#define	XFS_BTREE_TRACE_ARGBII(c, b, i, j)
#define	XFS_BTREE_TRACE_ARGI(c, i)
#define	XFS_BTREE_TRACE_ARGIPK(c, i, p, s)
#define	XFS_BTREE_TRACE_ARGIPR(c, i, p, r)
#define	XFS_BTREE_TRACE_ARGIK(c, i, k)
#define XFS_BTREE_TRACE_ARGR(c, r)
#define	XFS_BTREE_TRACE_CURSOR(c, t)

#endif	/* __XFS_BTREE_H__ */