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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
4 * All Rights Reserved.
5 */
6#include "xfs.h"
7#include "xfs_fs.h"
8#include "xfs_shared.h"
9#include "xfs_format.h"
10#include "xfs_log_format.h"
11#include "xfs_trans_resv.h"
12#include "xfs_bit.h"
13#include "xfs_mount.h"
14#include "xfs_inode.h"
15#include "xfs_trans.h"
16#include "xfs_buf_item.h"
17#include "xfs_btree.h"
18#include "xfs_errortag.h"
19#include "xfs_error.h"
20#include "xfs_trace.h"
21#include "xfs_alloc.h"
22#include "xfs_log.h"
23#include "xfs_btree_staging.h"
24#include "xfs_ag.h"
25#include "xfs_alloc_btree.h"
26#include "xfs_ialloc_btree.h"
27#include "xfs_bmap_btree.h"
28#include "xfs_rmap_btree.h"
29#include "xfs_refcount_btree.h"
30
31/*
32 * Btree magic numbers.
33 */
34static const uint32_t xfs_magics[2][XFS_BTNUM_MAX] = {
35 { XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, 0, XFS_BMAP_MAGIC, XFS_IBT_MAGIC,
36 XFS_FIBT_MAGIC, 0 },
37 { XFS_ABTB_CRC_MAGIC, XFS_ABTC_CRC_MAGIC, XFS_RMAP_CRC_MAGIC,
38 XFS_BMAP_CRC_MAGIC, XFS_IBT_CRC_MAGIC, XFS_FIBT_CRC_MAGIC,
39 XFS_REFC_CRC_MAGIC }
40};
41
42uint32_t
43xfs_btree_magic(
44 int crc,
45 xfs_btnum_t btnum)
46{
47 uint32_t magic = xfs_magics[crc][btnum];
48
49 /* Ensure we asked for crc for crc-only magics. */
50 ASSERT(magic != 0);
51 return magic;
52}
53
54/*
55 * These sibling pointer checks are optimised for null sibling pointers. This
56 * happens a lot, and we don't need to byte swap at runtime if the sibling
57 * pointer is NULL.
58 *
59 * These are explicitly marked at inline because the cost of calling them as
60 * functions instead of inlining them is about 36 bytes extra code per call site
61 * on x86-64. Yes, gcc-11 fails to inline them, and explicit inlining of these
62 * two sibling check functions reduces the compiled code size by over 300
63 * bytes.
64 */
65static inline xfs_failaddr_t
66xfs_btree_check_lblock_siblings(
67 struct xfs_mount *mp,
68 struct xfs_btree_cur *cur,
69 int level,
70 xfs_fsblock_t fsb,
71 __be64 dsibling)
72{
73 xfs_fsblock_t sibling;
74
75 if (dsibling == cpu_to_be64(NULLFSBLOCK))
76 return NULL;
77
78 sibling = be64_to_cpu(dsibling);
79 if (sibling == fsb)
80 return __this_address;
81 if (level >= 0) {
82 if (!xfs_btree_check_lptr(cur, sibling, level + 1))
83 return __this_address;
84 } else {
85 if (!xfs_verify_fsbno(mp, sibling))
86 return __this_address;
87 }
88
89 return NULL;
90}
91
92static inline xfs_failaddr_t
93xfs_btree_check_sblock_siblings(
94 struct xfs_perag *pag,
95 struct xfs_btree_cur *cur,
96 int level,
97 xfs_agblock_t agbno,
98 __be32 dsibling)
99{
100 xfs_agblock_t sibling;
101
102 if (dsibling == cpu_to_be32(NULLAGBLOCK))
103 return NULL;
104
105 sibling = be32_to_cpu(dsibling);
106 if (sibling == agbno)
107 return __this_address;
108 if (level >= 0) {
109 if (!xfs_btree_check_sptr(cur, sibling, level + 1))
110 return __this_address;
111 } else {
112 if (!xfs_verify_agbno(pag, sibling))
113 return __this_address;
114 }
115 return NULL;
116}
117
118/*
119 * Check a long btree block header. Return the address of the failing check,
120 * or NULL if everything is ok.
121 */
122xfs_failaddr_t
123__xfs_btree_check_lblock(
124 struct xfs_btree_cur *cur,
125 struct xfs_btree_block *block,
126 int level,
127 struct xfs_buf *bp)
128{
129 struct xfs_mount *mp = cur->bc_mp;
130 xfs_btnum_t btnum = cur->bc_btnum;
131 int crc = xfs_has_crc(mp);
132 xfs_failaddr_t fa;
133 xfs_fsblock_t fsb = NULLFSBLOCK;
134
135 if (crc) {
136 if (!uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid))
137 return __this_address;
138 if (block->bb_u.l.bb_blkno !=
139 cpu_to_be64(bp ? xfs_buf_daddr(bp) : XFS_BUF_DADDR_NULL))
140 return __this_address;
141 if (block->bb_u.l.bb_pad != cpu_to_be32(0))
142 return __this_address;
143 }
144
145 if (be32_to_cpu(block->bb_magic) != xfs_btree_magic(crc, btnum))
146 return __this_address;
147 if (be16_to_cpu(block->bb_level) != level)
148 return __this_address;
149 if (be16_to_cpu(block->bb_numrecs) >
150 cur->bc_ops->get_maxrecs(cur, level))
151 return __this_address;
152
153 if (bp)
154 fsb = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp));
155
156 fa = xfs_btree_check_lblock_siblings(mp, cur, level, fsb,
157 block->bb_u.l.bb_leftsib);
158 if (!fa)
159 fa = xfs_btree_check_lblock_siblings(mp, cur, level, fsb,
160 block->bb_u.l.bb_rightsib);
161 return fa;
162}
163
164/* Check a long btree block header. */
165static int
166xfs_btree_check_lblock(
167 struct xfs_btree_cur *cur,
168 struct xfs_btree_block *block,
169 int level,
170 struct xfs_buf *bp)
171{
172 struct xfs_mount *mp = cur->bc_mp;
173 xfs_failaddr_t fa;
174
175 fa = __xfs_btree_check_lblock(cur, block, level, bp);
176 if (XFS_IS_CORRUPT(mp, fa != NULL) ||
177 XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BTREE_CHECK_LBLOCK)) {
178 if (bp)
179 trace_xfs_btree_corrupt(bp, _RET_IP_);
180 return -EFSCORRUPTED;
181 }
182 return 0;
183}
184
185/*
186 * Check a short btree block header. Return the address of the failing check,
187 * or NULL if everything is ok.
188 */
189xfs_failaddr_t
190__xfs_btree_check_sblock(
191 struct xfs_btree_cur *cur,
192 struct xfs_btree_block *block,
193 int level,
194 struct xfs_buf *bp)
195{
196 struct xfs_mount *mp = cur->bc_mp;
197 struct xfs_perag *pag = cur->bc_ag.pag;
198 xfs_btnum_t btnum = cur->bc_btnum;
199 int crc = xfs_has_crc(mp);
200 xfs_failaddr_t fa;
201 xfs_agblock_t agbno = NULLAGBLOCK;
202
203 if (crc) {
204 if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid))
205 return __this_address;
206 if (block->bb_u.s.bb_blkno !=
207 cpu_to_be64(bp ? xfs_buf_daddr(bp) : XFS_BUF_DADDR_NULL))
208 return __this_address;
209 }
210
211 if (be32_to_cpu(block->bb_magic) != xfs_btree_magic(crc, btnum))
212 return __this_address;
213 if (be16_to_cpu(block->bb_level) != level)
214 return __this_address;
215 if (be16_to_cpu(block->bb_numrecs) >
216 cur->bc_ops->get_maxrecs(cur, level))
217 return __this_address;
218
219 if (bp)
220 agbno = xfs_daddr_to_agbno(mp, xfs_buf_daddr(bp));
221
222 fa = xfs_btree_check_sblock_siblings(pag, cur, level, agbno,
223 block->bb_u.s.bb_leftsib);
224 if (!fa)
225 fa = xfs_btree_check_sblock_siblings(pag, cur, level, agbno,
226 block->bb_u.s.bb_rightsib);
227 return fa;
228}
229
230/* Check a short btree block header. */
231STATIC int
232xfs_btree_check_sblock(
233 struct xfs_btree_cur *cur,
234 struct xfs_btree_block *block,
235 int level,
236 struct xfs_buf *bp)
237{
238 struct xfs_mount *mp = cur->bc_mp;
239 xfs_failaddr_t fa;
240
241 fa = __xfs_btree_check_sblock(cur, block, level, bp);
242 if (XFS_IS_CORRUPT(mp, fa != NULL) ||
243 XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BTREE_CHECK_SBLOCK)) {
244 if (bp)
245 trace_xfs_btree_corrupt(bp, _RET_IP_);
246 return -EFSCORRUPTED;
247 }
248 return 0;
249}
250
251/*
252 * Debug routine: check that block header is ok.
253 */
254int
255xfs_btree_check_block(
256 struct xfs_btree_cur *cur, /* btree cursor */
257 struct xfs_btree_block *block, /* generic btree block pointer */
258 int level, /* level of the btree block */
259 struct xfs_buf *bp) /* buffer containing block, if any */
260{
261 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
262 return xfs_btree_check_lblock(cur, block, level, bp);
263 else
264 return xfs_btree_check_sblock(cur, block, level, bp);
265}
266
267/* Check that this long pointer is valid and points within the fs. */
268bool
269xfs_btree_check_lptr(
270 struct xfs_btree_cur *cur,
271 xfs_fsblock_t fsbno,
272 int level)
273{
274 if (level <= 0)
275 return false;
276 return xfs_verify_fsbno(cur->bc_mp, fsbno);
277}
278
279/* Check that this short pointer is valid and points within the AG. */
280bool
281xfs_btree_check_sptr(
282 struct xfs_btree_cur *cur,
283 xfs_agblock_t agbno,
284 int level)
285{
286 if (level <= 0)
287 return false;
288 return xfs_verify_agbno(cur->bc_ag.pag, agbno);
289}
290
291/*
292 * Check that a given (indexed) btree pointer at a certain level of a
293 * btree is valid and doesn't point past where it should.
294 */
295static int
296xfs_btree_check_ptr(
297 struct xfs_btree_cur *cur,
298 const union xfs_btree_ptr *ptr,
299 int index,
300 int level)
301{
302 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
303 if (xfs_btree_check_lptr(cur, be64_to_cpu((&ptr->l)[index]),
304 level))
305 return 0;
306 xfs_err(cur->bc_mp,
307"Inode %llu fork %d: Corrupt btree %d pointer at level %d index %d.",
308 cur->bc_ino.ip->i_ino,
309 cur->bc_ino.whichfork, cur->bc_btnum,
310 level, index);
311 } else {
312 if (xfs_btree_check_sptr(cur, be32_to_cpu((&ptr->s)[index]),
313 level))
314 return 0;
315 xfs_err(cur->bc_mp,
316"AG %u: Corrupt btree %d pointer at level %d index %d.",
317 cur->bc_ag.pag->pag_agno, cur->bc_btnum,
318 level, index);
319 }
320
321 return -EFSCORRUPTED;
322}
323
324#ifdef DEBUG
325# define xfs_btree_debug_check_ptr xfs_btree_check_ptr
326#else
327# define xfs_btree_debug_check_ptr(...) (0)
328#endif
329
330/*
331 * Calculate CRC on the whole btree block and stuff it into the
332 * long-form btree header.
333 *
334 * Prior to calculting the CRC, pull the LSN out of the buffer log item and put
335 * it into the buffer so recovery knows what the last modification was that made
336 * it to disk.
337 */
338void
339xfs_btree_lblock_calc_crc(
340 struct xfs_buf *bp)
341{
342 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
343 struct xfs_buf_log_item *bip = bp->b_log_item;
344
345 if (!xfs_has_crc(bp->b_mount))
346 return;
347 if (bip)
348 block->bb_u.l.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
349 xfs_buf_update_cksum(bp, XFS_BTREE_LBLOCK_CRC_OFF);
350}
351
352bool
353xfs_btree_lblock_verify_crc(
354 struct xfs_buf *bp)
355{
356 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
357 struct xfs_mount *mp = bp->b_mount;
358
359 if (xfs_has_crc(mp)) {
360 if (!xfs_log_check_lsn(mp, be64_to_cpu(block->bb_u.l.bb_lsn)))
361 return false;
362 return xfs_buf_verify_cksum(bp, XFS_BTREE_LBLOCK_CRC_OFF);
363 }
364
365 return true;
366}
367
368/*
369 * Calculate CRC on the whole btree block and stuff it into the
370 * short-form btree header.
371 *
372 * Prior to calculting the CRC, pull the LSN out of the buffer log item and put
373 * it into the buffer so recovery knows what the last modification was that made
374 * it to disk.
375 */
376void
377xfs_btree_sblock_calc_crc(
378 struct xfs_buf *bp)
379{
380 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
381 struct xfs_buf_log_item *bip = bp->b_log_item;
382
383 if (!xfs_has_crc(bp->b_mount))
384 return;
385 if (bip)
386 block->bb_u.s.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
387 xfs_buf_update_cksum(bp, XFS_BTREE_SBLOCK_CRC_OFF);
388}
389
390bool
391xfs_btree_sblock_verify_crc(
392 struct xfs_buf *bp)
393{
394 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
395 struct xfs_mount *mp = bp->b_mount;
396
397 if (xfs_has_crc(mp)) {
398 if (!xfs_log_check_lsn(mp, be64_to_cpu(block->bb_u.s.bb_lsn)))
399 return false;
400 return xfs_buf_verify_cksum(bp, XFS_BTREE_SBLOCK_CRC_OFF);
401 }
402
403 return true;
404}
405
406static int
407xfs_btree_free_block(
408 struct xfs_btree_cur *cur,
409 struct xfs_buf *bp)
410{
411 int error;
412
413 error = cur->bc_ops->free_block(cur, bp);
414 if (!error) {
415 xfs_trans_binval(cur->bc_tp, bp);
416 XFS_BTREE_STATS_INC(cur, free);
417 }
418 return error;
419}
420
421/*
422 * Delete the btree cursor.
423 */
424void
425xfs_btree_del_cursor(
426 struct xfs_btree_cur *cur, /* btree cursor */
427 int error) /* del because of error */
428{
429 int i; /* btree level */
430
431 /*
432 * Clear the buffer pointers and release the buffers. If we're doing
433 * this because of an error, inspect all of the entries in the bc_bufs
434 * array for buffers to be unlocked. This is because some of the btree
435 * code works from level n down to 0, and if we get an error along the
436 * way we won't have initialized all the entries down to 0.
437 */
438 for (i = 0; i < cur->bc_nlevels; i++) {
439 if (cur->bc_levels[i].bp)
440 xfs_trans_brelse(cur->bc_tp, cur->bc_levels[i].bp);
441 else if (!error)
442 break;
443 }
444
445 /*
446 * If we are doing a BMBT update, the number of unaccounted blocks
447 * allocated during this cursor life time should be zero. If it's not
448 * zero, then we should be shut down or on our way to shutdown due to
449 * cancelling a dirty transaction on error.
450 */
451 ASSERT(cur->bc_btnum != XFS_BTNUM_BMAP || cur->bc_ino.allocated == 0 ||
452 xfs_is_shutdown(cur->bc_mp) || error != 0);
453 if (unlikely(cur->bc_flags & XFS_BTREE_STAGING))
454 kmem_free(cur->bc_ops);
455 if (!(cur->bc_flags & XFS_BTREE_LONG_PTRS) && cur->bc_ag.pag)
456 xfs_perag_put(cur->bc_ag.pag);
457 kmem_cache_free(cur->bc_cache, cur);
458}
459
460/*
461 * Duplicate the btree cursor.
462 * Allocate a new one, copy the record, re-get the buffers.
463 */
464int /* error */
465xfs_btree_dup_cursor(
466 struct xfs_btree_cur *cur, /* input cursor */
467 struct xfs_btree_cur **ncur) /* output cursor */
468{
469 struct xfs_buf *bp; /* btree block's buffer pointer */
470 int error; /* error return value */
471 int i; /* level number of btree block */
472 xfs_mount_t *mp; /* mount structure for filesystem */
473 struct xfs_btree_cur *new; /* new cursor value */
474 xfs_trans_t *tp; /* transaction pointer, can be NULL */
475
476 tp = cur->bc_tp;
477 mp = cur->bc_mp;
478
479 /*
480 * Allocate a new cursor like the old one.
481 */
482 new = cur->bc_ops->dup_cursor(cur);
483
484 /*
485 * Copy the record currently in the cursor.
486 */
487 new->bc_rec = cur->bc_rec;
488
489 /*
490 * For each level current, re-get the buffer and copy the ptr value.
491 */
492 for (i = 0; i < new->bc_nlevels; i++) {
493 new->bc_levels[i].ptr = cur->bc_levels[i].ptr;
494 new->bc_levels[i].ra = cur->bc_levels[i].ra;
495 bp = cur->bc_levels[i].bp;
496 if (bp) {
497 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
498 xfs_buf_daddr(bp), mp->m_bsize,
499 0, &bp,
500 cur->bc_ops->buf_ops);
501 if (error) {
502 xfs_btree_del_cursor(new, error);
503 *ncur = NULL;
504 return error;
505 }
506 }
507 new->bc_levels[i].bp = bp;
508 }
509 *ncur = new;
510 return 0;
511}
512
513/*
514 * XFS btree block layout and addressing:
515 *
516 * There are two types of blocks in the btree: leaf and non-leaf blocks.
517 *
518 * The leaf record start with a header then followed by records containing
519 * the values. A non-leaf block also starts with the same header, and
520 * then first contains lookup keys followed by an equal number of pointers
521 * to the btree blocks at the previous level.
522 *
523 * +--------+-------+-------+-------+-------+-------+-------+
524 * Leaf: | header | rec 1 | rec 2 | rec 3 | rec 4 | rec 5 | rec N |
525 * +--------+-------+-------+-------+-------+-------+-------+
526 *
527 * +--------+-------+-------+-------+-------+-------+-------+
528 * Non-Leaf: | header | key 1 | key 2 | key N | ptr 1 | ptr 2 | ptr N |
529 * +--------+-------+-------+-------+-------+-------+-------+
530 *
531 * The header is called struct xfs_btree_block for reasons better left unknown
532 * and comes in different versions for short (32bit) and long (64bit) block
533 * pointers. The record and key structures are defined by the btree instances
534 * and opaque to the btree core. The block pointers are simple disk endian
535 * integers, available in a short (32bit) and long (64bit) variant.
536 *
537 * The helpers below calculate the offset of a given record, key or pointer
538 * into a btree block (xfs_btree_*_offset) or return a pointer to the given
539 * record, key or pointer (xfs_btree_*_addr). Note that all addressing
540 * inside the btree block is done using indices starting at one, not zero!
541 *
542 * If XFS_BTREE_OVERLAPPING is set, then this btree supports keys containing
543 * overlapping intervals. In such a tree, records are still sorted lowest to
544 * highest and indexed by the smallest key value that refers to the record.
545 * However, nodes are different: each pointer has two associated keys -- one
546 * indexing the lowest key available in the block(s) below (the same behavior
547 * as the key in a regular btree) and another indexing the highest key
548 * available in the block(s) below. Because records are /not/ sorted by the
549 * highest key, all leaf block updates require us to compute the highest key
550 * that matches any record in the leaf and to recursively update the high keys
551 * in the nodes going further up in the tree, if necessary. Nodes look like
552 * this:
553 *
554 * +--------+-----+-----+-----+-----+-----+-------+-------+-----+
555 * Non-Leaf: | header | lo1 | hi1 | lo2 | hi2 | ... | ptr 1 | ptr 2 | ... |
556 * +--------+-----+-----+-----+-----+-----+-------+-------+-----+
557 *
558 * To perform an interval query on an overlapped tree, perform the usual
559 * depth-first search and use the low and high keys to decide if we can skip
560 * that particular node. If a leaf node is reached, return the records that
561 * intersect the interval. Note that an interval query may return numerous
562 * entries. For a non-overlapped tree, simply search for the record associated
563 * with the lowest key and iterate forward until a non-matching record is
564 * found. Section 14.3 ("Interval Trees") of _Introduction to Algorithms_ by
565 * Cormen, Leiserson, Rivest, and Stein (2nd or 3rd ed. only) discuss this in
566 * more detail.
567 *
568 * Why do we care about overlapping intervals? Let's say you have a bunch of
569 * reverse mapping records on a reflink filesystem:
570 *
571 * 1: +- file A startblock B offset C length D -----------+
572 * 2: +- file E startblock F offset G length H --------------+
573 * 3: +- file I startblock F offset J length K --+
574 * 4: +- file L... --+
575 *
576 * Now say we want to map block (B+D) into file A at offset (C+D). Ideally,
577 * we'd simply increment the length of record 1. But how do we find the record
578 * that ends at (B+D-1) (i.e. record 1)? A LE lookup of (B+D-1) would return
579 * record 3 because the keys are ordered first by startblock. An interval
580 * query would return records 1 and 2 because they both overlap (B+D-1), and
581 * from that we can pick out record 1 as the appropriate left neighbor.
582 *
583 * In the non-overlapped case you can do a LE lookup and decrement the cursor
584 * because a record's interval must end before the next record.
585 */
586
587/*
588 * Return size of the btree block header for this btree instance.
589 */
590static inline size_t xfs_btree_block_len(struct xfs_btree_cur *cur)
591{
592 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
593 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
594 return XFS_BTREE_LBLOCK_CRC_LEN;
595 return XFS_BTREE_LBLOCK_LEN;
596 }
597 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
598 return XFS_BTREE_SBLOCK_CRC_LEN;
599 return XFS_BTREE_SBLOCK_LEN;
600}
601
602/*
603 * Return size of btree block pointers for this btree instance.
604 */
605static inline size_t xfs_btree_ptr_len(struct xfs_btree_cur *cur)
606{
607 return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
608 sizeof(__be64) : sizeof(__be32);
609}
610
611/*
612 * Calculate offset of the n-th record in a btree block.
613 */
614STATIC size_t
615xfs_btree_rec_offset(
616 struct xfs_btree_cur *cur,
617 int n)
618{
619 return xfs_btree_block_len(cur) +
620 (n - 1) * cur->bc_ops->rec_len;
621}
622
623/*
624 * Calculate offset of the n-th key in a btree block.
625 */
626STATIC size_t
627xfs_btree_key_offset(
628 struct xfs_btree_cur *cur,
629 int n)
630{
631 return xfs_btree_block_len(cur) +
632 (n - 1) * cur->bc_ops->key_len;
633}
634
635/*
636 * Calculate offset of the n-th high key in a btree block.
637 */
638STATIC size_t
639xfs_btree_high_key_offset(
640 struct xfs_btree_cur *cur,
641 int n)
642{
643 return xfs_btree_block_len(cur) +
644 (n - 1) * cur->bc_ops->key_len + (cur->bc_ops->key_len / 2);
645}
646
647/*
648 * Calculate offset of the n-th block pointer in a btree block.
649 */
650STATIC size_t
651xfs_btree_ptr_offset(
652 struct xfs_btree_cur *cur,
653 int n,
654 int level)
655{
656 return xfs_btree_block_len(cur) +
657 cur->bc_ops->get_maxrecs(cur, level) * cur->bc_ops->key_len +
658 (n - 1) * xfs_btree_ptr_len(cur);
659}
660
661/*
662 * Return a pointer to the n-th record in the btree block.
663 */
664union xfs_btree_rec *
665xfs_btree_rec_addr(
666 struct xfs_btree_cur *cur,
667 int n,
668 struct xfs_btree_block *block)
669{
670 return (union xfs_btree_rec *)
671 ((char *)block + xfs_btree_rec_offset(cur, n));
672}
673
674/*
675 * Return a pointer to the n-th key in the btree block.
676 */
677union xfs_btree_key *
678xfs_btree_key_addr(
679 struct xfs_btree_cur *cur,
680 int n,
681 struct xfs_btree_block *block)
682{
683 return (union xfs_btree_key *)
684 ((char *)block + xfs_btree_key_offset(cur, n));
685}
686
687/*
688 * Return a pointer to the n-th high key in the btree block.
689 */
690union xfs_btree_key *
691xfs_btree_high_key_addr(
692 struct xfs_btree_cur *cur,
693 int n,
694 struct xfs_btree_block *block)
695{
696 return (union xfs_btree_key *)
697 ((char *)block + xfs_btree_high_key_offset(cur, n));
698}
699
700/*
701 * Return a pointer to the n-th block pointer in the btree block.
702 */
703union xfs_btree_ptr *
704xfs_btree_ptr_addr(
705 struct xfs_btree_cur *cur,
706 int n,
707 struct xfs_btree_block *block)
708{
709 int level = xfs_btree_get_level(block);
710
711 ASSERT(block->bb_level != 0);
712
713 return (union xfs_btree_ptr *)
714 ((char *)block + xfs_btree_ptr_offset(cur, n, level));
715}
716
717struct xfs_ifork *
718xfs_btree_ifork_ptr(
719 struct xfs_btree_cur *cur)
720{
721 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
722
723 if (cur->bc_flags & XFS_BTREE_STAGING)
724 return cur->bc_ino.ifake->if_fork;
725 return xfs_ifork_ptr(cur->bc_ino.ip, cur->bc_ino.whichfork);
726}
727
728/*
729 * Get the root block which is stored in the inode.
730 *
731 * For now this btree implementation assumes the btree root is always
732 * stored in the if_broot field of an inode fork.
733 */
734STATIC struct xfs_btree_block *
735xfs_btree_get_iroot(
736 struct xfs_btree_cur *cur)
737{
738 struct xfs_ifork *ifp = xfs_btree_ifork_ptr(cur);
739
740 return (struct xfs_btree_block *)ifp->if_broot;
741}
742
743/*
744 * Retrieve the block pointer from the cursor at the given level.
745 * This may be an inode btree root or from a buffer.
746 */
747struct xfs_btree_block * /* generic btree block pointer */
748xfs_btree_get_block(
749 struct xfs_btree_cur *cur, /* btree cursor */
750 int level, /* level in btree */
751 struct xfs_buf **bpp) /* buffer containing the block */
752{
753 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
754 (level == cur->bc_nlevels - 1)) {
755 *bpp = NULL;
756 return xfs_btree_get_iroot(cur);
757 }
758
759 *bpp = cur->bc_levels[level].bp;
760 return XFS_BUF_TO_BLOCK(*bpp);
761}
762
763/*
764 * Change the cursor to point to the first record at the given level.
765 * Other levels are unaffected.
766 */
767STATIC int /* success=1, failure=0 */
768xfs_btree_firstrec(
769 struct xfs_btree_cur *cur, /* btree cursor */
770 int level) /* level to change */
771{
772 struct xfs_btree_block *block; /* generic btree block pointer */
773 struct xfs_buf *bp; /* buffer containing block */
774
775 /*
776 * Get the block pointer for this level.
777 */
778 block = xfs_btree_get_block(cur, level, &bp);
779 if (xfs_btree_check_block(cur, block, level, bp))
780 return 0;
781 /*
782 * It's empty, there is no such record.
783 */
784 if (!block->bb_numrecs)
785 return 0;
786 /*
787 * Set the ptr value to 1, that's the first record/key.
788 */
789 cur->bc_levels[level].ptr = 1;
790 return 1;
791}
792
793/*
794 * Change the cursor to point to the last record in the current block
795 * at the given level. Other levels are unaffected.
796 */
797STATIC int /* success=1, failure=0 */
798xfs_btree_lastrec(
799 struct xfs_btree_cur *cur, /* btree cursor */
800 int level) /* level to change */
801{
802 struct xfs_btree_block *block; /* generic btree block pointer */
803 struct xfs_buf *bp; /* buffer containing block */
804
805 /*
806 * Get the block pointer for this level.
807 */
808 block = xfs_btree_get_block(cur, level, &bp);
809 if (xfs_btree_check_block(cur, block, level, bp))
810 return 0;
811 /*
812 * It's empty, there is no such record.
813 */
814 if (!block->bb_numrecs)
815 return 0;
816 /*
817 * Set the ptr value to numrecs, that's the last record/key.
818 */
819 cur->bc_levels[level].ptr = be16_to_cpu(block->bb_numrecs);
820 return 1;
821}
822
823/*
824 * Compute first and last byte offsets for the fields given.
825 * Interprets the offsets table, which contains struct field offsets.
826 */
827void
828xfs_btree_offsets(
829 uint32_t fields, /* bitmask of fields */
830 const short *offsets, /* table of field offsets */
831 int nbits, /* number of bits to inspect */
832 int *first, /* output: first byte offset */
833 int *last) /* output: last byte offset */
834{
835 int i; /* current bit number */
836 uint32_t imask; /* mask for current bit number */
837
838 ASSERT(fields != 0);
839 /*
840 * Find the lowest bit, so the first byte offset.
841 */
842 for (i = 0, imask = 1u; ; i++, imask <<= 1) {
843 if (imask & fields) {
844 *first = offsets[i];
845 break;
846 }
847 }
848 /*
849 * Find the highest bit, so the last byte offset.
850 */
851 for (i = nbits - 1, imask = 1u << i; ; i--, imask >>= 1) {
852 if (imask & fields) {
853 *last = offsets[i + 1] - 1;
854 break;
855 }
856 }
857}
858
859/*
860 * Get a buffer for the block, return it read in.
861 * Long-form addressing.
862 */
863int
864xfs_btree_read_bufl(
865 struct xfs_mount *mp, /* file system mount point */
866 struct xfs_trans *tp, /* transaction pointer */
867 xfs_fsblock_t fsbno, /* file system block number */
868 struct xfs_buf **bpp, /* buffer for fsbno */
869 int refval, /* ref count value for buffer */
870 const struct xfs_buf_ops *ops)
871{
872 struct xfs_buf *bp; /* return value */
873 xfs_daddr_t d; /* real disk block address */
874 int error;
875
876 if (!xfs_verify_fsbno(mp, fsbno))
877 return -EFSCORRUPTED;
878 d = XFS_FSB_TO_DADDR(mp, fsbno);
879 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
880 mp->m_bsize, 0, &bp, ops);
881 if (error)
882 return error;
883 if (bp)
884 xfs_buf_set_ref(bp, refval);
885 *bpp = bp;
886 return 0;
887}
888
889/*
890 * Read-ahead the block, don't wait for it, don't return a buffer.
891 * Long-form addressing.
892 */
893/* ARGSUSED */
894void
895xfs_btree_reada_bufl(
896 struct xfs_mount *mp, /* file system mount point */
897 xfs_fsblock_t fsbno, /* file system block number */
898 xfs_extlen_t count, /* count of filesystem blocks */
899 const struct xfs_buf_ops *ops)
900{
901 xfs_daddr_t d;
902
903 ASSERT(fsbno != NULLFSBLOCK);
904 d = XFS_FSB_TO_DADDR(mp, fsbno);
905 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, ops);
906}
907
908/*
909 * Read-ahead the block, don't wait for it, don't return a buffer.
910 * Short-form addressing.
911 */
912/* ARGSUSED */
913void
914xfs_btree_reada_bufs(
915 struct xfs_mount *mp, /* file system mount point */
916 xfs_agnumber_t agno, /* allocation group number */
917 xfs_agblock_t agbno, /* allocation group block number */
918 xfs_extlen_t count, /* count of filesystem blocks */
919 const struct xfs_buf_ops *ops)
920{
921 xfs_daddr_t d;
922
923 ASSERT(agno != NULLAGNUMBER);
924 ASSERT(agbno != NULLAGBLOCK);
925 d = XFS_AGB_TO_DADDR(mp, agno, agbno);
926 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, ops);
927}
928
929STATIC int
930xfs_btree_readahead_lblock(
931 struct xfs_btree_cur *cur,
932 int lr,
933 struct xfs_btree_block *block)
934{
935 int rval = 0;
936 xfs_fsblock_t left = be64_to_cpu(block->bb_u.l.bb_leftsib);
937 xfs_fsblock_t right = be64_to_cpu(block->bb_u.l.bb_rightsib);
938
939 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLFSBLOCK) {
940 xfs_btree_reada_bufl(cur->bc_mp, left, 1,
941 cur->bc_ops->buf_ops);
942 rval++;
943 }
944
945 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLFSBLOCK) {
946 xfs_btree_reada_bufl(cur->bc_mp, right, 1,
947 cur->bc_ops->buf_ops);
948 rval++;
949 }
950
951 return rval;
952}
953
954STATIC int
955xfs_btree_readahead_sblock(
956 struct xfs_btree_cur *cur,
957 int lr,
958 struct xfs_btree_block *block)
959{
960 int rval = 0;
961 xfs_agblock_t left = be32_to_cpu(block->bb_u.s.bb_leftsib);
962 xfs_agblock_t right = be32_to_cpu(block->bb_u.s.bb_rightsib);
963
964
965 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLAGBLOCK) {
966 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_ag.pag->pag_agno,
967 left, 1, cur->bc_ops->buf_ops);
968 rval++;
969 }
970
971 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLAGBLOCK) {
972 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_ag.pag->pag_agno,
973 right, 1, cur->bc_ops->buf_ops);
974 rval++;
975 }
976
977 return rval;
978}
979
980/*
981 * Read-ahead btree blocks, at the given level.
982 * Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA.
983 */
984STATIC int
985xfs_btree_readahead(
986 struct xfs_btree_cur *cur, /* btree cursor */
987 int lev, /* level in btree */
988 int lr) /* left/right bits */
989{
990 struct xfs_btree_block *block;
991
992 /*
993 * No readahead needed if we are at the root level and the
994 * btree root is stored in the inode.
995 */
996 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
997 (lev == cur->bc_nlevels - 1))
998 return 0;
999
1000 if ((cur->bc_levels[lev].ra | lr) == cur->bc_levels[lev].ra)
1001 return 0;
1002
1003 cur->bc_levels[lev].ra |= lr;
1004 block = XFS_BUF_TO_BLOCK(cur->bc_levels[lev].bp);
1005
1006 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1007 return xfs_btree_readahead_lblock(cur, lr, block);
1008 return xfs_btree_readahead_sblock(cur, lr, block);
1009}
1010
1011STATIC int
1012xfs_btree_ptr_to_daddr(
1013 struct xfs_btree_cur *cur,
1014 const union xfs_btree_ptr *ptr,
1015 xfs_daddr_t *daddr)
1016{
1017 xfs_fsblock_t fsbno;
1018 xfs_agblock_t agbno;
1019 int error;
1020
1021 error = xfs_btree_check_ptr(cur, ptr, 0, 1);
1022 if (error)
1023 return error;
1024
1025 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1026 fsbno = be64_to_cpu(ptr->l);
1027 *daddr = XFS_FSB_TO_DADDR(cur->bc_mp, fsbno);
1028 } else {
1029 agbno = be32_to_cpu(ptr->s);
1030 *daddr = XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_ag.pag->pag_agno,
1031 agbno);
1032 }
1033
1034 return 0;
1035}
1036
1037/*
1038 * Readahead @count btree blocks at the given @ptr location.
1039 *
1040 * We don't need to care about long or short form btrees here as we have a
1041 * method of converting the ptr directly to a daddr available to us.
1042 */
1043STATIC void
1044xfs_btree_readahead_ptr(
1045 struct xfs_btree_cur *cur,
1046 union xfs_btree_ptr *ptr,
1047 xfs_extlen_t count)
1048{
1049 xfs_daddr_t daddr;
1050
1051 if (xfs_btree_ptr_to_daddr(cur, ptr, &daddr))
1052 return;
1053 xfs_buf_readahead(cur->bc_mp->m_ddev_targp, daddr,
1054 cur->bc_mp->m_bsize * count, cur->bc_ops->buf_ops);
1055}
1056
1057/*
1058 * Set the buffer for level "lev" in the cursor to bp, releasing
1059 * any previous buffer.
1060 */
1061STATIC void
1062xfs_btree_setbuf(
1063 struct xfs_btree_cur *cur, /* btree cursor */
1064 int lev, /* level in btree */
1065 struct xfs_buf *bp) /* new buffer to set */
1066{
1067 struct xfs_btree_block *b; /* btree block */
1068
1069 if (cur->bc_levels[lev].bp)
1070 xfs_trans_brelse(cur->bc_tp, cur->bc_levels[lev].bp);
1071 cur->bc_levels[lev].bp = bp;
1072 cur->bc_levels[lev].ra = 0;
1073
1074 b = XFS_BUF_TO_BLOCK(bp);
1075 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1076 if (b->bb_u.l.bb_leftsib == cpu_to_be64(NULLFSBLOCK))
1077 cur->bc_levels[lev].ra |= XFS_BTCUR_LEFTRA;
1078 if (b->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK))
1079 cur->bc_levels[lev].ra |= XFS_BTCUR_RIGHTRA;
1080 } else {
1081 if (b->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK))
1082 cur->bc_levels[lev].ra |= XFS_BTCUR_LEFTRA;
1083 if (b->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK))
1084 cur->bc_levels[lev].ra |= XFS_BTCUR_RIGHTRA;
1085 }
1086}
1087
1088bool
1089xfs_btree_ptr_is_null(
1090 struct xfs_btree_cur *cur,
1091 const union xfs_btree_ptr *ptr)
1092{
1093 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1094 return ptr->l == cpu_to_be64(NULLFSBLOCK);
1095 else
1096 return ptr->s == cpu_to_be32(NULLAGBLOCK);
1097}
1098
1099void
1100xfs_btree_set_ptr_null(
1101 struct xfs_btree_cur *cur,
1102 union xfs_btree_ptr *ptr)
1103{
1104 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1105 ptr->l = cpu_to_be64(NULLFSBLOCK);
1106 else
1107 ptr->s = cpu_to_be32(NULLAGBLOCK);
1108}
1109
1110/*
1111 * Get/set/init sibling pointers
1112 */
1113void
1114xfs_btree_get_sibling(
1115 struct xfs_btree_cur *cur,
1116 struct xfs_btree_block *block,
1117 union xfs_btree_ptr *ptr,
1118 int lr)
1119{
1120 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
1121
1122 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1123 if (lr == XFS_BB_RIGHTSIB)
1124 ptr->l = block->bb_u.l.bb_rightsib;
1125 else
1126 ptr->l = block->bb_u.l.bb_leftsib;
1127 } else {
1128 if (lr == XFS_BB_RIGHTSIB)
1129 ptr->s = block->bb_u.s.bb_rightsib;
1130 else
1131 ptr->s = block->bb_u.s.bb_leftsib;
1132 }
1133}
1134
1135void
1136xfs_btree_set_sibling(
1137 struct xfs_btree_cur *cur,
1138 struct xfs_btree_block *block,
1139 const union xfs_btree_ptr *ptr,
1140 int lr)
1141{
1142 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
1143
1144 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1145 if (lr == XFS_BB_RIGHTSIB)
1146 block->bb_u.l.bb_rightsib = ptr->l;
1147 else
1148 block->bb_u.l.bb_leftsib = ptr->l;
1149 } else {
1150 if (lr == XFS_BB_RIGHTSIB)
1151 block->bb_u.s.bb_rightsib = ptr->s;
1152 else
1153 block->bb_u.s.bb_leftsib = ptr->s;
1154 }
1155}
1156
1157void
1158xfs_btree_init_block_int(
1159 struct xfs_mount *mp,
1160 struct xfs_btree_block *buf,
1161 xfs_daddr_t blkno,
1162 xfs_btnum_t btnum,
1163 __u16 level,
1164 __u16 numrecs,
1165 __u64 owner,
1166 unsigned int flags)
1167{
1168 int crc = xfs_has_crc(mp);
1169 __u32 magic = xfs_btree_magic(crc, btnum);
1170
1171 buf->bb_magic = cpu_to_be32(magic);
1172 buf->bb_level = cpu_to_be16(level);
1173 buf->bb_numrecs = cpu_to_be16(numrecs);
1174
1175 if (flags & XFS_BTREE_LONG_PTRS) {
1176 buf->bb_u.l.bb_leftsib = cpu_to_be64(NULLFSBLOCK);
1177 buf->bb_u.l.bb_rightsib = cpu_to_be64(NULLFSBLOCK);
1178 if (crc) {
1179 buf->bb_u.l.bb_blkno = cpu_to_be64(blkno);
1180 buf->bb_u.l.bb_owner = cpu_to_be64(owner);
1181 uuid_copy(&buf->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid);
1182 buf->bb_u.l.bb_pad = 0;
1183 buf->bb_u.l.bb_lsn = 0;
1184 }
1185 } else {
1186 /* owner is a 32 bit value on short blocks */
1187 __u32 __owner = (__u32)owner;
1188
1189 buf->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
1190 buf->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
1191 if (crc) {
1192 buf->bb_u.s.bb_blkno = cpu_to_be64(blkno);
1193 buf->bb_u.s.bb_owner = cpu_to_be32(__owner);
1194 uuid_copy(&buf->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid);
1195 buf->bb_u.s.bb_lsn = 0;
1196 }
1197 }
1198}
1199
1200void
1201xfs_btree_init_block(
1202 struct xfs_mount *mp,
1203 struct xfs_buf *bp,
1204 xfs_btnum_t btnum,
1205 __u16 level,
1206 __u16 numrecs,
1207 __u64 owner)
1208{
1209 xfs_btree_init_block_int(mp, XFS_BUF_TO_BLOCK(bp), xfs_buf_daddr(bp),
1210 btnum, level, numrecs, owner, 0);
1211}
1212
1213void
1214xfs_btree_init_block_cur(
1215 struct xfs_btree_cur *cur,
1216 struct xfs_buf *bp,
1217 int level,
1218 int numrecs)
1219{
1220 __u64 owner;
1221
1222 /*
1223 * we can pull the owner from the cursor right now as the different
1224 * owners align directly with the pointer size of the btree. This may
1225 * change in future, but is safe for current users of the generic btree
1226 * code.
1227 */
1228 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1229 owner = cur->bc_ino.ip->i_ino;
1230 else
1231 owner = cur->bc_ag.pag->pag_agno;
1232
1233 xfs_btree_init_block_int(cur->bc_mp, XFS_BUF_TO_BLOCK(bp),
1234 xfs_buf_daddr(bp), cur->bc_btnum, level,
1235 numrecs, owner, cur->bc_flags);
1236}
1237
1238/*
1239 * Return true if ptr is the last record in the btree and
1240 * we need to track updates to this record. The decision
1241 * will be further refined in the update_lastrec method.
1242 */
1243STATIC int
1244xfs_btree_is_lastrec(
1245 struct xfs_btree_cur *cur,
1246 struct xfs_btree_block *block,
1247 int level)
1248{
1249 union xfs_btree_ptr ptr;
1250
1251 if (level > 0)
1252 return 0;
1253 if (!(cur->bc_flags & XFS_BTREE_LASTREC_UPDATE))
1254 return 0;
1255
1256 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1257 if (!xfs_btree_ptr_is_null(cur, &ptr))
1258 return 0;
1259 return 1;
1260}
1261
1262STATIC void
1263xfs_btree_buf_to_ptr(
1264 struct xfs_btree_cur *cur,
1265 struct xfs_buf *bp,
1266 union xfs_btree_ptr *ptr)
1267{
1268 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1269 ptr->l = cpu_to_be64(XFS_DADDR_TO_FSB(cur->bc_mp,
1270 xfs_buf_daddr(bp)));
1271 else {
1272 ptr->s = cpu_to_be32(xfs_daddr_to_agbno(cur->bc_mp,
1273 xfs_buf_daddr(bp)));
1274 }
1275}
1276
1277STATIC void
1278xfs_btree_set_refs(
1279 struct xfs_btree_cur *cur,
1280 struct xfs_buf *bp)
1281{
1282 switch (cur->bc_btnum) {
1283 case XFS_BTNUM_BNO:
1284 case XFS_BTNUM_CNT:
1285 xfs_buf_set_ref(bp, XFS_ALLOC_BTREE_REF);
1286 break;
1287 case XFS_BTNUM_INO:
1288 case XFS_BTNUM_FINO:
1289 xfs_buf_set_ref(bp, XFS_INO_BTREE_REF);
1290 break;
1291 case XFS_BTNUM_BMAP:
1292 xfs_buf_set_ref(bp, XFS_BMAP_BTREE_REF);
1293 break;
1294 case XFS_BTNUM_RMAP:
1295 xfs_buf_set_ref(bp, XFS_RMAP_BTREE_REF);
1296 break;
1297 case XFS_BTNUM_REFC:
1298 xfs_buf_set_ref(bp, XFS_REFC_BTREE_REF);
1299 break;
1300 default:
1301 ASSERT(0);
1302 }
1303}
1304
1305int
1306xfs_btree_get_buf_block(
1307 struct xfs_btree_cur *cur,
1308 const union xfs_btree_ptr *ptr,
1309 struct xfs_btree_block **block,
1310 struct xfs_buf **bpp)
1311{
1312 struct xfs_mount *mp = cur->bc_mp;
1313 xfs_daddr_t d;
1314 int error;
1315
1316 error = xfs_btree_ptr_to_daddr(cur, ptr, &d);
1317 if (error)
1318 return error;
1319 error = xfs_trans_get_buf(cur->bc_tp, mp->m_ddev_targp, d, mp->m_bsize,
1320 0, bpp);
1321 if (error)
1322 return error;
1323
1324 (*bpp)->b_ops = cur->bc_ops->buf_ops;
1325 *block = XFS_BUF_TO_BLOCK(*bpp);
1326 return 0;
1327}
1328
1329/*
1330 * Read in the buffer at the given ptr and return the buffer and
1331 * the block pointer within the buffer.
1332 */
1333int
1334xfs_btree_read_buf_block(
1335 struct xfs_btree_cur *cur,
1336 const union xfs_btree_ptr *ptr,
1337 int flags,
1338 struct xfs_btree_block **block,
1339 struct xfs_buf **bpp)
1340{
1341 struct xfs_mount *mp = cur->bc_mp;
1342 xfs_daddr_t d;
1343 int error;
1344
1345 /* need to sort out how callers deal with failures first */
1346 ASSERT(!(flags & XBF_TRYLOCK));
1347
1348 error = xfs_btree_ptr_to_daddr(cur, ptr, &d);
1349 if (error)
1350 return error;
1351 error = xfs_trans_read_buf(mp, cur->bc_tp, mp->m_ddev_targp, d,
1352 mp->m_bsize, flags, bpp,
1353 cur->bc_ops->buf_ops);
1354 if (error)
1355 return error;
1356
1357 xfs_btree_set_refs(cur, *bpp);
1358 *block = XFS_BUF_TO_BLOCK(*bpp);
1359 return 0;
1360}
1361
1362/*
1363 * Copy keys from one btree block to another.
1364 */
1365void
1366xfs_btree_copy_keys(
1367 struct xfs_btree_cur *cur,
1368 union xfs_btree_key *dst_key,
1369 const union xfs_btree_key *src_key,
1370 int numkeys)
1371{
1372 ASSERT(numkeys >= 0);
1373 memcpy(dst_key, src_key, numkeys * cur->bc_ops->key_len);
1374}
1375
1376/*
1377 * Copy records from one btree block to another.
1378 */
1379STATIC void
1380xfs_btree_copy_recs(
1381 struct xfs_btree_cur *cur,
1382 union xfs_btree_rec *dst_rec,
1383 union xfs_btree_rec *src_rec,
1384 int numrecs)
1385{
1386 ASSERT(numrecs >= 0);
1387 memcpy(dst_rec, src_rec, numrecs * cur->bc_ops->rec_len);
1388}
1389
1390/*
1391 * Copy block pointers from one btree block to another.
1392 */
1393void
1394xfs_btree_copy_ptrs(
1395 struct xfs_btree_cur *cur,
1396 union xfs_btree_ptr *dst_ptr,
1397 const union xfs_btree_ptr *src_ptr,
1398 int numptrs)
1399{
1400 ASSERT(numptrs >= 0);
1401 memcpy(dst_ptr, src_ptr, numptrs * xfs_btree_ptr_len(cur));
1402}
1403
1404/*
1405 * Shift keys one index left/right inside a single btree block.
1406 */
1407STATIC void
1408xfs_btree_shift_keys(
1409 struct xfs_btree_cur *cur,
1410 union xfs_btree_key *key,
1411 int dir,
1412 int numkeys)
1413{
1414 char *dst_key;
1415
1416 ASSERT(numkeys >= 0);
1417 ASSERT(dir == 1 || dir == -1);
1418
1419 dst_key = (char *)key + (dir * cur->bc_ops->key_len);
1420 memmove(dst_key, key, numkeys * cur->bc_ops->key_len);
1421}
1422
1423/*
1424 * Shift records one index left/right inside a single btree block.
1425 */
1426STATIC void
1427xfs_btree_shift_recs(
1428 struct xfs_btree_cur *cur,
1429 union xfs_btree_rec *rec,
1430 int dir,
1431 int numrecs)
1432{
1433 char *dst_rec;
1434
1435 ASSERT(numrecs >= 0);
1436 ASSERT(dir == 1 || dir == -1);
1437
1438 dst_rec = (char *)rec + (dir * cur->bc_ops->rec_len);
1439 memmove(dst_rec, rec, numrecs * cur->bc_ops->rec_len);
1440}
1441
1442/*
1443 * Shift block pointers one index left/right inside a single btree block.
1444 */
1445STATIC void
1446xfs_btree_shift_ptrs(
1447 struct xfs_btree_cur *cur,
1448 union xfs_btree_ptr *ptr,
1449 int dir,
1450 int numptrs)
1451{
1452 char *dst_ptr;
1453
1454 ASSERT(numptrs >= 0);
1455 ASSERT(dir == 1 || dir == -1);
1456
1457 dst_ptr = (char *)ptr + (dir * xfs_btree_ptr_len(cur));
1458 memmove(dst_ptr, ptr, numptrs * xfs_btree_ptr_len(cur));
1459}
1460
1461/*
1462 * Log key values from the btree block.
1463 */
1464STATIC void
1465xfs_btree_log_keys(
1466 struct xfs_btree_cur *cur,
1467 struct xfs_buf *bp,
1468 int first,
1469 int last)
1470{
1471
1472 if (bp) {
1473 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1474 xfs_trans_log_buf(cur->bc_tp, bp,
1475 xfs_btree_key_offset(cur, first),
1476 xfs_btree_key_offset(cur, last + 1) - 1);
1477 } else {
1478 xfs_trans_log_inode(cur->bc_tp, cur->bc_ino.ip,
1479 xfs_ilog_fbroot(cur->bc_ino.whichfork));
1480 }
1481}
1482
1483/*
1484 * Log record values from the btree block.
1485 */
1486void
1487xfs_btree_log_recs(
1488 struct xfs_btree_cur *cur,
1489 struct xfs_buf *bp,
1490 int first,
1491 int last)
1492{
1493
1494 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1495 xfs_trans_log_buf(cur->bc_tp, bp,
1496 xfs_btree_rec_offset(cur, first),
1497 xfs_btree_rec_offset(cur, last + 1) - 1);
1498
1499}
1500
1501/*
1502 * Log block pointer fields from a btree block (nonleaf).
1503 */
1504STATIC void
1505xfs_btree_log_ptrs(
1506 struct xfs_btree_cur *cur, /* btree cursor */
1507 struct xfs_buf *bp, /* buffer containing btree block */
1508 int first, /* index of first pointer to log */
1509 int last) /* index of last pointer to log */
1510{
1511
1512 if (bp) {
1513 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
1514 int level = xfs_btree_get_level(block);
1515
1516 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1517 xfs_trans_log_buf(cur->bc_tp, bp,
1518 xfs_btree_ptr_offset(cur, first, level),
1519 xfs_btree_ptr_offset(cur, last + 1, level) - 1);
1520 } else {
1521 xfs_trans_log_inode(cur->bc_tp, cur->bc_ino.ip,
1522 xfs_ilog_fbroot(cur->bc_ino.whichfork));
1523 }
1524
1525}
1526
1527/*
1528 * Log fields from a btree block header.
1529 */
1530void
1531xfs_btree_log_block(
1532 struct xfs_btree_cur *cur, /* btree cursor */
1533 struct xfs_buf *bp, /* buffer containing btree block */
1534 uint32_t fields) /* mask of fields: XFS_BB_... */
1535{
1536 int first; /* first byte offset logged */
1537 int last; /* last byte offset logged */
1538 static const short soffsets[] = { /* table of offsets (short) */
1539 offsetof(struct xfs_btree_block, bb_magic),
1540 offsetof(struct xfs_btree_block, bb_level),
1541 offsetof(struct xfs_btree_block, bb_numrecs),
1542 offsetof(struct xfs_btree_block, bb_u.s.bb_leftsib),
1543 offsetof(struct xfs_btree_block, bb_u.s.bb_rightsib),
1544 offsetof(struct xfs_btree_block, bb_u.s.bb_blkno),
1545 offsetof(struct xfs_btree_block, bb_u.s.bb_lsn),
1546 offsetof(struct xfs_btree_block, bb_u.s.bb_uuid),
1547 offsetof(struct xfs_btree_block, bb_u.s.bb_owner),
1548 offsetof(struct xfs_btree_block, bb_u.s.bb_crc),
1549 XFS_BTREE_SBLOCK_CRC_LEN
1550 };
1551 static const short loffsets[] = { /* table of offsets (long) */
1552 offsetof(struct xfs_btree_block, bb_magic),
1553 offsetof(struct xfs_btree_block, bb_level),
1554 offsetof(struct xfs_btree_block, bb_numrecs),
1555 offsetof(struct xfs_btree_block, bb_u.l.bb_leftsib),
1556 offsetof(struct xfs_btree_block, bb_u.l.bb_rightsib),
1557 offsetof(struct xfs_btree_block, bb_u.l.bb_blkno),
1558 offsetof(struct xfs_btree_block, bb_u.l.bb_lsn),
1559 offsetof(struct xfs_btree_block, bb_u.l.bb_uuid),
1560 offsetof(struct xfs_btree_block, bb_u.l.bb_owner),
1561 offsetof(struct xfs_btree_block, bb_u.l.bb_crc),
1562 offsetof(struct xfs_btree_block, bb_u.l.bb_pad),
1563 XFS_BTREE_LBLOCK_CRC_LEN
1564 };
1565
1566 if (bp) {
1567 int nbits;
1568
1569 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) {
1570 /*
1571 * We don't log the CRC when updating a btree
1572 * block but instead recreate it during log
1573 * recovery. As the log buffers have checksums
1574 * of their own this is safe and avoids logging a crc
1575 * update in a lot of places.
1576 */
1577 if (fields == XFS_BB_ALL_BITS)
1578 fields = XFS_BB_ALL_BITS_CRC;
1579 nbits = XFS_BB_NUM_BITS_CRC;
1580 } else {
1581 nbits = XFS_BB_NUM_BITS;
1582 }
1583 xfs_btree_offsets(fields,
1584 (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
1585 loffsets : soffsets,
1586 nbits, &first, &last);
1587 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1588 xfs_trans_log_buf(cur->bc_tp, bp, first, last);
1589 } else {
1590 xfs_trans_log_inode(cur->bc_tp, cur->bc_ino.ip,
1591 xfs_ilog_fbroot(cur->bc_ino.whichfork));
1592 }
1593}
1594
1595/*
1596 * Increment cursor by one record at the level.
1597 * For nonzero levels the leaf-ward information is untouched.
1598 */
1599int /* error */
1600xfs_btree_increment(
1601 struct xfs_btree_cur *cur,
1602 int level,
1603 int *stat) /* success/failure */
1604{
1605 struct xfs_btree_block *block;
1606 union xfs_btree_ptr ptr;
1607 struct xfs_buf *bp;
1608 int error; /* error return value */
1609 int lev;
1610
1611 ASSERT(level < cur->bc_nlevels);
1612
1613 /* Read-ahead to the right at this level. */
1614 xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
1615
1616 /* Get a pointer to the btree block. */
1617 block = xfs_btree_get_block(cur, level, &bp);
1618
1619#ifdef DEBUG
1620 error = xfs_btree_check_block(cur, block, level, bp);
1621 if (error)
1622 goto error0;
1623#endif
1624
1625 /* We're done if we remain in the block after the increment. */
1626 if (++cur->bc_levels[level].ptr <= xfs_btree_get_numrecs(block))
1627 goto out1;
1628
1629 /* Fail if we just went off the right edge of the tree. */
1630 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1631 if (xfs_btree_ptr_is_null(cur, &ptr))
1632 goto out0;
1633
1634 XFS_BTREE_STATS_INC(cur, increment);
1635
1636 /*
1637 * March up the tree incrementing pointers.
1638 * Stop when we don't go off the right edge of a block.
1639 */
1640 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1641 block = xfs_btree_get_block(cur, lev, &bp);
1642
1643#ifdef DEBUG
1644 error = xfs_btree_check_block(cur, block, lev, bp);
1645 if (error)
1646 goto error0;
1647#endif
1648
1649 if (++cur->bc_levels[lev].ptr <= xfs_btree_get_numrecs(block))
1650 break;
1651
1652 /* Read-ahead the right block for the next loop. */
1653 xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA);
1654 }
1655
1656 /*
1657 * If we went off the root then we are either seriously
1658 * confused or have the tree root in an inode.
1659 */
1660 if (lev == cur->bc_nlevels) {
1661 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1662 goto out0;
1663 ASSERT(0);
1664 error = -EFSCORRUPTED;
1665 goto error0;
1666 }
1667 ASSERT(lev < cur->bc_nlevels);
1668
1669 /*
1670 * Now walk back down the tree, fixing up the cursor's buffer
1671 * pointers and key numbers.
1672 */
1673 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1674 union xfs_btree_ptr *ptrp;
1675
1676 ptrp = xfs_btree_ptr_addr(cur, cur->bc_levels[lev].ptr, block);
1677 --lev;
1678 error = xfs_btree_read_buf_block(cur, ptrp, 0, &block, &bp);
1679 if (error)
1680 goto error0;
1681
1682 xfs_btree_setbuf(cur, lev, bp);
1683 cur->bc_levels[lev].ptr = 1;
1684 }
1685out1:
1686 *stat = 1;
1687 return 0;
1688
1689out0:
1690 *stat = 0;
1691 return 0;
1692
1693error0:
1694 return error;
1695}
1696
1697/*
1698 * Decrement cursor by one record at the level.
1699 * For nonzero levels the leaf-ward information is untouched.
1700 */
1701int /* error */
1702xfs_btree_decrement(
1703 struct xfs_btree_cur *cur,
1704 int level,
1705 int *stat) /* success/failure */
1706{
1707 struct xfs_btree_block *block;
1708 struct xfs_buf *bp;
1709 int error; /* error return value */
1710 int lev;
1711 union xfs_btree_ptr ptr;
1712
1713 ASSERT(level < cur->bc_nlevels);
1714
1715 /* Read-ahead to the left at this level. */
1716 xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA);
1717
1718 /* We're done if we remain in the block after the decrement. */
1719 if (--cur->bc_levels[level].ptr > 0)
1720 goto out1;
1721
1722 /* Get a pointer to the btree block. */
1723 block = xfs_btree_get_block(cur, level, &bp);
1724
1725#ifdef DEBUG
1726 error = xfs_btree_check_block(cur, block, level, bp);
1727 if (error)
1728 goto error0;
1729#endif
1730
1731 /* Fail if we just went off the left edge of the tree. */
1732 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
1733 if (xfs_btree_ptr_is_null(cur, &ptr))
1734 goto out0;
1735
1736 XFS_BTREE_STATS_INC(cur, decrement);
1737
1738 /*
1739 * March up the tree decrementing pointers.
1740 * Stop when we don't go off the left edge of a block.
1741 */
1742 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1743 if (--cur->bc_levels[lev].ptr > 0)
1744 break;
1745 /* Read-ahead the left block for the next loop. */
1746 xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA);
1747 }
1748
1749 /*
1750 * If we went off the root then we are seriously confused.
1751 * or the root of the tree is in an inode.
1752 */
1753 if (lev == cur->bc_nlevels) {
1754 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1755 goto out0;
1756 ASSERT(0);
1757 error = -EFSCORRUPTED;
1758 goto error0;
1759 }
1760 ASSERT(lev < cur->bc_nlevels);
1761
1762 /*
1763 * Now walk back down the tree, fixing up the cursor's buffer
1764 * pointers and key numbers.
1765 */
1766 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1767 union xfs_btree_ptr *ptrp;
1768
1769 ptrp = xfs_btree_ptr_addr(cur, cur->bc_levels[lev].ptr, block);
1770 --lev;
1771 error = xfs_btree_read_buf_block(cur, ptrp, 0, &block, &bp);
1772 if (error)
1773 goto error0;
1774 xfs_btree_setbuf(cur, lev, bp);
1775 cur->bc_levels[lev].ptr = xfs_btree_get_numrecs(block);
1776 }
1777out1:
1778 *stat = 1;
1779 return 0;
1780
1781out0:
1782 *stat = 0;
1783 return 0;
1784
1785error0:
1786 return error;
1787}
1788
1789int
1790xfs_btree_lookup_get_block(
1791 struct xfs_btree_cur *cur, /* btree cursor */
1792 int level, /* level in the btree */
1793 const union xfs_btree_ptr *pp, /* ptr to btree block */
1794 struct xfs_btree_block **blkp) /* return btree block */
1795{
1796 struct xfs_buf *bp; /* buffer pointer for btree block */
1797 xfs_daddr_t daddr;
1798 int error = 0;
1799
1800 /* special case the root block if in an inode */
1801 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1802 (level == cur->bc_nlevels - 1)) {
1803 *blkp = xfs_btree_get_iroot(cur);
1804 return 0;
1805 }
1806
1807 /*
1808 * If the old buffer at this level for the disk address we are
1809 * looking for re-use it.
1810 *
1811 * Otherwise throw it away and get a new one.
1812 */
1813 bp = cur->bc_levels[level].bp;
1814 error = xfs_btree_ptr_to_daddr(cur, pp, &daddr);
1815 if (error)
1816 return error;
1817 if (bp && xfs_buf_daddr(bp) == daddr) {
1818 *blkp = XFS_BUF_TO_BLOCK(bp);
1819 return 0;
1820 }
1821
1822 error = xfs_btree_read_buf_block(cur, pp, 0, blkp, &bp);
1823 if (error)
1824 return error;
1825
1826 /* Check the inode owner since the verifiers don't. */
1827 if (xfs_has_crc(cur->bc_mp) &&
1828 !(cur->bc_ino.flags & XFS_BTCUR_BMBT_INVALID_OWNER) &&
1829 (cur->bc_flags & XFS_BTREE_LONG_PTRS) &&
1830 be64_to_cpu((*blkp)->bb_u.l.bb_owner) !=
1831 cur->bc_ino.ip->i_ino)
1832 goto out_bad;
1833
1834 /* Did we get the level we were looking for? */
1835 if (be16_to_cpu((*blkp)->bb_level) != level)
1836 goto out_bad;
1837
1838 /* Check that internal nodes have at least one record. */
1839 if (level != 0 && be16_to_cpu((*blkp)->bb_numrecs) == 0)
1840 goto out_bad;
1841
1842 xfs_btree_setbuf(cur, level, bp);
1843 return 0;
1844
1845out_bad:
1846 *blkp = NULL;
1847 xfs_buf_mark_corrupt(bp);
1848 xfs_trans_brelse(cur->bc_tp, bp);
1849 return -EFSCORRUPTED;
1850}
1851
1852/*
1853 * Get current search key. For level 0 we don't actually have a key
1854 * structure so we make one up from the record. For all other levels
1855 * we just return the right key.
1856 */
1857STATIC union xfs_btree_key *
1858xfs_lookup_get_search_key(
1859 struct xfs_btree_cur *cur,
1860 int level,
1861 int keyno,
1862 struct xfs_btree_block *block,
1863 union xfs_btree_key *kp)
1864{
1865 if (level == 0) {
1866 cur->bc_ops->init_key_from_rec(kp,
1867 xfs_btree_rec_addr(cur, keyno, block));
1868 return kp;
1869 }
1870
1871 return xfs_btree_key_addr(cur, keyno, block);
1872}
1873
1874/*
1875 * Lookup the record. The cursor is made to point to it, based on dir.
1876 * stat is set to 0 if can't find any such record, 1 for success.
1877 */
1878int /* error */
1879xfs_btree_lookup(
1880 struct xfs_btree_cur *cur, /* btree cursor */
1881 xfs_lookup_t dir, /* <=, ==, or >= */
1882 int *stat) /* success/failure */
1883{
1884 struct xfs_btree_block *block; /* current btree block */
1885 int64_t diff; /* difference for the current key */
1886 int error; /* error return value */
1887 int keyno; /* current key number */
1888 int level; /* level in the btree */
1889 union xfs_btree_ptr *pp; /* ptr to btree block */
1890 union xfs_btree_ptr ptr; /* ptr to btree block */
1891
1892 XFS_BTREE_STATS_INC(cur, lookup);
1893
1894 /* No such thing as a zero-level tree. */
1895 if (XFS_IS_CORRUPT(cur->bc_mp, cur->bc_nlevels == 0))
1896 return -EFSCORRUPTED;
1897
1898 block = NULL;
1899 keyno = 0;
1900
1901 /* initialise start pointer from cursor */
1902 cur->bc_ops->init_ptr_from_cur(cur, &ptr);
1903 pp = &ptr;
1904
1905 /*
1906 * Iterate over each level in the btree, starting at the root.
1907 * For each level above the leaves, find the key we need, based
1908 * on the lookup record, then follow the corresponding block
1909 * pointer down to the next level.
1910 */
1911 for (level = cur->bc_nlevels - 1, diff = 1; level >= 0; level--) {
1912 /* Get the block we need to do the lookup on. */
1913 error = xfs_btree_lookup_get_block(cur, level, pp, &block);
1914 if (error)
1915 goto error0;
1916
1917 if (diff == 0) {
1918 /*
1919 * If we already had a key match at a higher level, we
1920 * know we need to use the first entry in this block.
1921 */
1922 keyno = 1;
1923 } else {
1924 /* Otherwise search this block. Do a binary search. */
1925
1926 int high; /* high entry number */
1927 int low; /* low entry number */
1928
1929 /* Set low and high entry numbers, 1-based. */
1930 low = 1;
1931 high = xfs_btree_get_numrecs(block);
1932 if (!high) {
1933 /* Block is empty, must be an empty leaf. */
1934 if (level != 0 || cur->bc_nlevels != 1) {
1935 XFS_CORRUPTION_ERROR(__func__,
1936 XFS_ERRLEVEL_LOW,
1937 cur->bc_mp, block,
1938 sizeof(*block));
1939 return -EFSCORRUPTED;
1940 }
1941
1942 cur->bc_levels[0].ptr = dir != XFS_LOOKUP_LE;
1943 *stat = 0;
1944 return 0;
1945 }
1946
1947 /* Binary search the block. */
1948 while (low <= high) {
1949 union xfs_btree_key key;
1950 union xfs_btree_key *kp;
1951
1952 XFS_BTREE_STATS_INC(cur, compare);
1953
1954 /* keyno is average of low and high. */
1955 keyno = (low + high) >> 1;
1956
1957 /* Get current search key */
1958 kp = xfs_lookup_get_search_key(cur, level,
1959 keyno, block, &key);
1960
1961 /*
1962 * Compute difference to get next direction:
1963 * - less than, move right
1964 * - greater than, move left
1965 * - equal, we're done
1966 */
1967 diff = cur->bc_ops->key_diff(cur, kp);
1968 if (diff < 0)
1969 low = keyno + 1;
1970 else if (diff > 0)
1971 high = keyno - 1;
1972 else
1973 break;
1974 }
1975 }
1976
1977 /*
1978 * If there are more levels, set up for the next level
1979 * by getting the block number and filling in the cursor.
1980 */
1981 if (level > 0) {
1982 /*
1983 * If we moved left, need the previous key number,
1984 * unless there isn't one.
1985 */
1986 if (diff > 0 && --keyno < 1)
1987 keyno = 1;
1988 pp = xfs_btree_ptr_addr(cur, keyno, block);
1989
1990 error = xfs_btree_debug_check_ptr(cur, pp, 0, level);
1991 if (error)
1992 goto error0;
1993
1994 cur->bc_levels[level].ptr = keyno;
1995 }
1996 }
1997
1998 /* Done with the search. See if we need to adjust the results. */
1999 if (dir != XFS_LOOKUP_LE && diff < 0) {
2000 keyno++;
2001 /*
2002 * If ge search and we went off the end of the block, but it's
2003 * not the last block, we're in the wrong block.
2004 */
2005 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
2006 if (dir == XFS_LOOKUP_GE &&
2007 keyno > xfs_btree_get_numrecs(block) &&
2008 !xfs_btree_ptr_is_null(cur, &ptr)) {
2009 int i;
2010
2011 cur->bc_levels[0].ptr = keyno;
2012 error = xfs_btree_increment(cur, 0, &i);
2013 if (error)
2014 goto error0;
2015 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1))
2016 return -EFSCORRUPTED;
2017 *stat = 1;
2018 return 0;
2019 }
2020 } else if (dir == XFS_LOOKUP_LE && diff > 0)
2021 keyno--;
2022 cur->bc_levels[0].ptr = keyno;
2023
2024 /* Return if we succeeded or not. */
2025 if (keyno == 0 || keyno > xfs_btree_get_numrecs(block))
2026 *stat = 0;
2027 else if (dir != XFS_LOOKUP_EQ || diff == 0)
2028 *stat = 1;
2029 else
2030 *stat = 0;
2031 return 0;
2032
2033error0:
2034 return error;
2035}
2036
2037/* Find the high key storage area from a regular key. */
2038union xfs_btree_key *
2039xfs_btree_high_key_from_key(
2040 struct xfs_btree_cur *cur,
2041 union xfs_btree_key *key)
2042{
2043 ASSERT(cur->bc_flags & XFS_BTREE_OVERLAPPING);
2044 return (union xfs_btree_key *)((char *)key +
2045 (cur->bc_ops->key_len / 2));
2046}
2047
2048/* Determine the low (and high if overlapped) keys of a leaf block */
2049STATIC void
2050xfs_btree_get_leaf_keys(
2051 struct xfs_btree_cur *cur,
2052 struct xfs_btree_block *block,
2053 union xfs_btree_key *key)
2054{
2055 union xfs_btree_key max_hkey;
2056 union xfs_btree_key hkey;
2057 union xfs_btree_rec *rec;
2058 union xfs_btree_key *high;
2059 int n;
2060
2061 rec = xfs_btree_rec_addr(cur, 1, block);
2062 cur->bc_ops->init_key_from_rec(key, rec);
2063
2064 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2065
2066 cur->bc_ops->init_high_key_from_rec(&max_hkey, rec);
2067 for (n = 2; n <= xfs_btree_get_numrecs(block); n++) {
2068 rec = xfs_btree_rec_addr(cur, n, block);
2069 cur->bc_ops->init_high_key_from_rec(&hkey, rec);
2070 if (xfs_btree_keycmp_gt(cur, &hkey, &max_hkey))
2071 max_hkey = hkey;
2072 }
2073
2074 high = xfs_btree_high_key_from_key(cur, key);
2075 memcpy(high, &max_hkey, cur->bc_ops->key_len / 2);
2076 }
2077}
2078
2079/* Determine the low (and high if overlapped) keys of a node block */
2080STATIC void
2081xfs_btree_get_node_keys(
2082 struct xfs_btree_cur *cur,
2083 struct xfs_btree_block *block,
2084 union xfs_btree_key *key)
2085{
2086 union xfs_btree_key *hkey;
2087 union xfs_btree_key *max_hkey;
2088 union xfs_btree_key *high;
2089 int n;
2090
2091 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2092 memcpy(key, xfs_btree_key_addr(cur, 1, block),
2093 cur->bc_ops->key_len / 2);
2094
2095 max_hkey = xfs_btree_high_key_addr(cur, 1, block);
2096 for (n = 2; n <= xfs_btree_get_numrecs(block); n++) {
2097 hkey = xfs_btree_high_key_addr(cur, n, block);
2098 if (xfs_btree_keycmp_gt(cur, hkey, max_hkey))
2099 max_hkey = hkey;
2100 }
2101
2102 high = xfs_btree_high_key_from_key(cur, key);
2103 memcpy(high, max_hkey, cur->bc_ops->key_len / 2);
2104 } else {
2105 memcpy(key, xfs_btree_key_addr(cur, 1, block),
2106 cur->bc_ops->key_len);
2107 }
2108}
2109
2110/* Derive the keys for any btree block. */
2111void
2112xfs_btree_get_keys(
2113 struct xfs_btree_cur *cur,
2114 struct xfs_btree_block *block,
2115 union xfs_btree_key *key)
2116{
2117 if (be16_to_cpu(block->bb_level) == 0)
2118 xfs_btree_get_leaf_keys(cur, block, key);
2119 else
2120 xfs_btree_get_node_keys(cur, block, key);
2121}
2122
2123/*
2124 * Decide if we need to update the parent keys of a btree block. For
2125 * a standard btree this is only necessary if we're updating the first
2126 * record/key. For an overlapping btree, we must always update the
2127 * keys because the highest key can be in any of the records or keys
2128 * in the block.
2129 */
2130static inline bool
2131xfs_btree_needs_key_update(
2132 struct xfs_btree_cur *cur,
2133 int ptr)
2134{
2135 return (cur->bc_flags & XFS_BTREE_OVERLAPPING) || ptr == 1;
2136}
2137
2138/*
2139 * Update the low and high parent keys of the given level, progressing
2140 * towards the root. If force_all is false, stop if the keys for a given
2141 * level do not need updating.
2142 */
2143STATIC int
2144__xfs_btree_updkeys(
2145 struct xfs_btree_cur *cur,
2146 int level,
2147 struct xfs_btree_block *block,
2148 struct xfs_buf *bp0,
2149 bool force_all)
2150{
2151 union xfs_btree_key key; /* keys from current level */
2152 union xfs_btree_key *lkey; /* keys from the next level up */
2153 union xfs_btree_key *hkey;
2154 union xfs_btree_key *nlkey; /* keys from the next level up */
2155 union xfs_btree_key *nhkey;
2156 struct xfs_buf *bp;
2157 int ptr;
2158
2159 ASSERT(cur->bc_flags & XFS_BTREE_OVERLAPPING);
2160
2161 /* Exit if there aren't any parent levels to update. */
2162 if (level + 1 >= cur->bc_nlevels)
2163 return 0;
2164
2165 trace_xfs_btree_updkeys(cur, level, bp0);
2166
2167 lkey = &key;
2168 hkey = xfs_btree_high_key_from_key(cur, lkey);
2169 xfs_btree_get_keys(cur, block, lkey);
2170 for (level++; level < cur->bc_nlevels; level++) {
2171#ifdef DEBUG
2172 int error;
2173#endif
2174 block = xfs_btree_get_block(cur, level, &bp);
2175 trace_xfs_btree_updkeys(cur, level, bp);
2176#ifdef DEBUG
2177 error = xfs_btree_check_block(cur, block, level, bp);
2178 if (error)
2179 return error;
2180#endif
2181 ptr = cur->bc_levels[level].ptr;
2182 nlkey = xfs_btree_key_addr(cur, ptr, block);
2183 nhkey = xfs_btree_high_key_addr(cur, ptr, block);
2184 if (!force_all &&
2185 xfs_btree_keycmp_eq(cur, nlkey, lkey) &&
2186 xfs_btree_keycmp_eq(cur, nhkey, hkey))
2187 break;
2188 xfs_btree_copy_keys(cur, nlkey, lkey, 1);
2189 xfs_btree_log_keys(cur, bp, ptr, ptr);
2190 if (level + 1 >= cur->bc_nlevels)
2191 break;
2192 xfs_btree_get_node_keys(cur, block, lkey);
2193 }
2194
2195 return 0;
2196}
2197
2198/* Update all the keys from some level in cursor back to the root. */
2199STATIC int
2200xfs_btree_updkeys_force(
2201 struct xfs_btree_cur *cur,
2202 int level)
2203{
2204 struct xfs_buf *bp;
2205 struct xfs_btree_block *block;
2206
2207 block = xfs_btree_get_block(cur, level, &bp);
2208 return __xfs_btree_updkeys(cur, level, block, bp, true);
2209}
2210
2211/*
2212 * Update the parent keys of the given level, progressing towards the root.
2213 */
2214STATIC int
2215xfs_btree_update_keys(
2216 struct xfs_btree_cur *cur,
2217 int level)
2218{
2219 struct xfs_btree_block *block;
2220 struct xfs_buf *bp;
2221 union xfs_btree_key *kp;
2222 union xfs_btree_key key;
2223 int ptr;
2224
2225 ASSERT(level >= 0);
2226
2227 block = xfs_btree_get_block(cur, level, &bp);
2228 if (cur->bc_flags & XFS_BTREE_OVERLAPPING)
2229 return __xfs_btree_updkeys(cur, level, block, bp, false);
2230
2231 /*
2232 * Go up the tree from this level toward the root.
2233 * At each level, update the key value to the value input.
2234 * Stop when we reach a level where the cursor isn't pointing
2235 * at the first entry in the block.
2236 */
2237 xfs_btree_get_keys(cur, block, &key);
2238 for (level++, ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) {
2239#ifdef DEBUG
2240 int error;
2241#endif
2242 block = xfs_btree_get_block(cur, level, &bp);
2243#ifdef DEBUG
2244 error = xfs_btree_check_block(cur, block, level, bp);
2245 if (error)
2246 return error;
2247#endif
2248 ptr = cur->bc_levels[level].ptr;
2249 kp = xfs_btree_key_addr(cur, ptr, block);
2250 xfs_btree_copy_keys(cur, kp, &key, 1);
2251 xfs_btree_log_keys(cur, bp, ptr, ptr);
2252 }
2253
2254 return 0;
2255}
2256
2257/*
2258 * Update the record referred to by cur to the value in the
2259 * given record. This either works (return 0) or gets an
2260 * EFSCORRUPTED error.
2261 */
2262int
2263xfs_btree_update(
2264 struct xfs_btree_cur *cur,
2265 union xfs_btree_rec *rec)
2266{
2267 struct xfs_btree_block *block;
2268 struct xfs_buf *bp;
2269 int error;
2270 int ptr;
2271 union xfs_btree_rec *rp;
2272
2273 /* Pick up the current block. */
2274 block = xfs_btree_get_block(cur, 0, &bp);
2275
2276#ifdef DEBUG
2277 error = xfs_btree_check_block(cur, block, 0, bp);
2278 if (error)
2279 goto error0;
2280#endif
2281 /* Get the address of the rec to be updated. */
2282 ptr = cur->bc_levels[0].ptr;
2283 rp = xfs_btree_rec_addr(cur, ptr, block);
2284
2285 /* Fill in the new contents and log them. */
2286 xfs_btree_copy_recs(cur, rp, rec, 1);
2287 xfs_btree_log_recs(cur, bp, ptr, ptr);
2288
2289 /*
2290 * If we are tracking the last record in the tree and
2291 * we are at the far right edge of the tree, update it.
2292 */
2293 if (xfs_btree_is_lastrec(cur, block, 0)) {
2294 cur->bc_ops->update_lastrec(cur, block, rec,
2295 ptr, LASTREC_UPDATE);
2296 }
2297
2298 /* Pass new key value up to our parent. */
2299 if (xfs_btree_needs_key_update(cur, ptr)) {
2300 error = xfs_btree_update_keys(cur, 0);
2301 if (error)
2302 goto error0;
2303 }
2304
2305 return 0;
2306
2307error0:
2308 return error;
2309}
2310
2311/*
2312 * Move 1 record left from cur/level if possible.
2313 * Update cur to reflect the new path.
2314 */
2315STATIC int /* error */
2316xfs_btree_lshift(
2317 struct xfs_btree_cur *cur,
2318 int level,
2319 int *stat) /* success/failure */
2320{
2321 struct xfs_buf *lbp; /* left buffer pointer */
2322 struct xfs_btree_block *left; /* left btree block */
2323 int lrecs; /* left record count */
2324 struct xfs_buf *rbp; /* right buffer pointer */
2325 struct xfs_btree_block *right; /* right btree block */
2326 struct xfs_btree_cur *tcur; /* temporary btree cursor */
2327 int rrecs; /* right record count */
2328 union xfs_btree_ptr lptr; /* left btree pointer */
2329 union xfs_btree_key *rkp = NULL; /* right btree key */
2330 union xfs_btree_ptr *rpp = NULL; /* right address pointer */
2331 union xfs_btree_rec *rrp = NULL; /* right record pointer */
2332 int error; /* error return value */
2333 int i;
2334
2335 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2336 level == cur->bc_nlevels - 1)
2337 goto out0;
2338
2339 /* Set up variables for this block as "right". */
2340 right = xfs_btree_get_block(cur, level, &rbp);
2341
2342#ifdef DEBUG
2343 error = xfs_btree_check_block(cur, right, level, rbp);
2344 if (error)
2345 goto error0;
2346#endif
2347
2348 /* If we've got no left sibling then we can't shift an entry left. */
2349 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2350 if (xfs_btree_ptr_is_null(cur, &lptr))
2351 goto out0;
2352
2353 /*
2354 * If the cursor entry is the one that would be moved, don't
2355 * do it... it's too complicated.
2356 */
2357 if (cur->bc_levels[level].ptr <= 1)
2358 goto out0;
2359
2360 /* Set up the left neighbor as "left". */
2361 error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
2362 if (error)
2363 goto error0;
2364
2365 /* If it's full, it can't take another entry. */
2366 lrecs = xfs_btree_get_numrecs(left);
2367 if (lrecs == cur->bc_ops->get_maxrecs(cur, level))
2368 goto out0;
2369
2370 rrecs = xfs_btree_get_numrecs(right);
2371
2372 /*
2373 * We add one entry to the left side and remove one for the right side.
2374 * Account for it here, the changes will be updated on disk and logged
2375 * later.
2376 */
2377 lrecs++;
2378 rrecs--;
2379
2380 XFS_BTREE_STATS_INC(cur, lshift);
2381 XFS_BTREE_STATS_ADD(cur, moves, 1);
2382
2383 /*
2384 * If non-leaf, copy a key and a ptr to the left block.
2385 * Log the changes to the left block.
2386 */
2387 if (level > 0) {
2388 /* It's a non-leaf. Move keys and pointers. */
2389 union xfs_btree_key *lkp; /* left btree key */
2390 union xfs_btree_ptr *lpp; /* left address pointer */
2391
2392 lkp = xfs_btree_key_addr(cur, lrecs, left);
2393 rkp = xfs_btree_key_addr(cur, 1, right);
2394
2395 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2396 rpp = xfs_btree_ptr_addr(cur, 1, right);
2397
2398 error = xfs_btree_debug_check_ptr(cur, rpp, 0, level);
2399 if (error)
2400 goto error0;
2401
2402 xfs_btree_copy_keys(cur, lkp, rkp, 1);
2403 xfs_btree_copy_ptrs(cur, lpp, rpp, 1);
2404
2405 xfs_btree_log_keys(cur, lbp, lrecs, lrecs);
2406 xfs_btree_log_ptrs(cur, lbp, lrecs, lrecs);
2407
2408 ASSERT(cur->bc_ops->keys_inorder(cur,
2409 xfs_btree_key_addr(cur, lrecs - 1, left), lkp));
2410 } else {
2411 /* It's a leaf. Move records. */
2412 union xfs_btree_rec *lrp; /* left record pointer */
2413
2414 lrp = xfs_btree_rec_addr(cur, lrecs, left);
2415 rrp = xfs_btree_rec_addr(cur, 1, right);
2416
2417 xfs_btree_copy_recs(cur, lrp, rrp, 1);
2418 xfs_btree_log_recs(cur, lbp, lrecs, lrecs);
2419
2420 ASSERT(cur->bc_ops->recs_inorder(cur,
2421 xfs_btree_rec_addr(cur, lrecs - 1, left), lrp));
2422 }
2423
2424 xfs_btree_set_numrecs(left, lrecs);
2425 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2426
2427 xfs_btree_set_numrecs(right, rrecs);
2428 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2429
2430 /*
2431 * Slide the contents of right down one entry.
2432 */
2433 XFS_BTREE_STATS_ADD(cur, moves, rrecs - 1);
2434 if (level > 0) {
2435 /* It's a nonleaf. operate on keys and ptrs */
2436 for (i = 0; i < rrecs; i++) {
2437 error = xfs_btree_debug_check_ptr(cur, rpp, i + 1, level);
2438 if (error)
2439 goto error0;
2440 }
2441
2442 xfs_btree_shift_keys(cur,
2443 xfs_btree_key_addr(cur, 2, right),
2444 -1, rrecs);
2445 xfs_btree_shift_ptrs(cur,
2446 xfs_btree_ptr_addr(cur, 2, right),
2447 -1, rrecs);
2448
2449 xfs_btree_log_keys(cur, rbp, 1, rrecs);
2450 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2451 } else {
2452 /* It's a leaf. operate on records */
2453 xfs_btree_shift_recs(cur,
2454 xfs_btree_rec_addr(cur, 2, right),
2455 -1, rrecs);
2456 xfs_btree_log_recs(cur, rbp, 1, rrecs);
2457 }
2458
2459 /*
2460 * Using a temporary cursor, update the parent key values of the
2461 * block on the left.
2462 */
2463 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2464 error = xfs_btree_dup_cursor(cur, &tcur);
2465 if (error)
2466 goto error0;
2467 i = xfs_btree_firstrec(tcur, level);
2468 if (XFS_IS_CORRUPT(tcur->bc_mp, i != 1)) {
2469 error = -EFSCORRUPTED;
2470 goto error0;
2471 }
2472
2473 error = xfs_btree_decrement(tcur, level, &i);
2474 if (error)
2475 goto error1;
2476
2477 /* Update the parent high keys of the left block, if needed. */
2478 error = xfs_btree_update_keys(tcur, level);
2479 if (error)
2480 goto error1;
2481
2482 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
2483 }
2484
2485 /* Update the parent keys of the right block. */
2486 error = xfs_btree_update_keys(cur, level);
2487 if (error)
2488 goto error0;
2489
2490 /* Slide the cursor value left one. */
2491 cur->bc_levels[level].ptr--;
2492
2493 *stat = 1;
2494 return 0;
2495
2496out0:
2497 *stat = 0;
2498 return 0;
2499
2500error0:
2501 return error;
2502
2503error1:
2504 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
2505 return error;
2506}
2507
2508/*
2509 * Move 1 record right from cur/level if possible.
2510 * Update cur to reflect the new path.
2511 */
2512STATIC int /* error */
2513xfs_btree_rshift(
2514 struct xfs_btree_cur *cur,
2515 int level,
2516 int *stat) /* success/failure */
2517{
2518 struct xfs_buf *lbp; /* left buffer pointer */
2519 struct xfs_btree_block *left; /* left btree block */
2520 struct xfs_buf *rbp; /* right buffer pointer */
2521 struct xfs_btree_block *right; /* right btree block */
2522 struct xfs_btree_cur *tcur; /* temporary btree cursor */
2523 union xfs_btree_ptr rptr; /* right block pointer */
2524 union xfs_btree_key *rkp; /* right btree key */
2525 int rrecs; /* right record count */
2526 int lrecs; /* left record count */
2527 int error; /* error return value */
2528 int i; /* loop counter */
2529
2530 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2531 (level == cur->bc_nlevels - 1))
2532 goto out0;
2533
2534 /* Set up variables for this block as "left". */
2535 left = xfs_btree_get_block(cur, level, &lbp);
2536
2537#ifdef DEBUG
2538 error = xfs_btree_check_block(cur, left, level, lbp);
2539 if (error)
2540 goto error0;
2541#endif
2542
2543 /* If we've got no right sibling then we can't shift an entry right. */
2544 xfs_btree_get_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2545 if (xfs_btree_ptr_is_null(cur, &rptr))
2546 goto out0;
2547
2548 /*
2549 * If the cursor entry is the one that would be moved, don't
2550 * do it... it's too complicated.
2551 */
2552 lrecs = xfs_btree_get_numrecs(left);
2553 if (cur->bc_levels[level].ptr >= lrecs)
2554 goto out0;
2555
2556 /* Set up the right neighbor as "right". */
2557 error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
2558 if (error)
2559 goto error0;
2560
2561 /* If it's full, it can't take another entry. */
2562 rrecs = xfs_btree_get_numrecs(right);
2563 if (rrecs == cur->bc_ops->get_maxrecs(cur, level))
2564 goto out0;
2565
2566 XFS_BTREE_STATS_INC(cur, rshift);
2567 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2568
2569 /*
2570 * Make a hole at the start of the right neighbor block, then
2571 * copy the last left block entry to the hole.
2572 */
2573 if (level > 0) {
2574 /* It's a nonleaf. make a hole in the keys and ptrs */
2575 union xfs_btree_key *lkp;
2576 union xfs_btree_ptr *lpp;
2577 union xfs_btree_ptr *rpp;
2578
2579 lkp = xfs_btree_key_addr(cur, lrecs, left);
2580 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2581 rkp = xfs_btree_key_addr(cur, 1, right);
2582 rpp = xfs_btree_ptr_addr(cur, 1, right);
2583
2584 for (i = rrecs - 1; i >= 0; i--) {
2585 error = xfs_btree_debug_check_ptr(cur, rpp, i, level);
2586 if (error)
2587 goto error0;
2588 }
2589
2590 xfs_btree_shift_keys(cur, rkp, 1, rrecs);
2591 xfs_btree_shift_ptrs(cur, rpp, 1, rrecs);
2592
2593 error = xfs_btree_debug_check_ptr(cur, lpp, 0, level);
2594 if (error)
2595 goto error0;
2596
2597 /* Now put the new data in, and log it. */
2598 xfs_btree_copy_keys(cur, rkp, lkp, 1);
2599 xfs_btree_copy_ptrs(cur, rpp, lpp, 1);
2600
2601 xfs_btree_log_keys(cur, rbp, 1, rrecs + 1);
2602 xfs_btree_log_ptrs(cur, rbp, 1, rrecs + 1);
2603
2604 ASSERT(cur->bc_ops->keys_inorder(cur, rkp,
2605 xfs_btree_key_addr(cur, 2, right)));
2606 } else {
2607 /* It's a leaf. make a hole in the records */
2608 union xfs_btree_rec *lrp;
2609 union xfs_btree_rec *rrp;
2610
2611 lrp = xfs_btree_rec_addr(cur, lrecs, left);
2612 rrp = xfs_btree_rec_addr(cur, 1, right);
2613
2614 xfs_btree_shift_recs(cur, rrp, 1, rrecs);
2615
2616 /* Now put the new data in, and log it. */
2617 xfs_btree_copy_recs(cur, rrp, lrp, 1);
2618 xfs_btree_log_recs(cur, rbp, 1, rrecs + 1);
2619 }
2620
2621 /*
2622 * Decrement and log left's numrecs, bump and log right's numrecs.
2623 */
2624 xfs_btree_set_numrecs(left, --lrecs);
2625 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2626
2627 xfs_btree_set_numrecs(right, ++rrecs);
2628 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2629
2630 /*
2631 * Using a temporary cursor, update the parent key values of the
2632 * block on the right.
2633 */
2634 error = xfs_btree_dup_cursor(cur, &tcur);
2635 if (error)
2636 goto error0;
2637 i = xfs_btree_lastrec(tcur, level);
2638 if (XFS_IS_CORRUPT(tcur->bc_mp, i != 1)) {
2639 error = -EFSCORRUPTED;
2640 goto error0;
2641 }
2642
2643 error = xfs_btree_increment(tcur, level, &i);
2644 if (error)
2645 goto error1;
2646
2647 /* Update the parent high keys of the left block, if needed. */
2648 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2649 error = xfs_btree_update_keys(cur, level);
2650 if (error)
2651 goto error1;
2652 }
2653
2654 /* Update the parent keys of the right block. */
2655 error = xfs_btree_update_keys(tcur, level);
2656 if (error)
2657 goto error1;
2658
2659 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
2660
2661 *stat = 1;
2662 return 0;
2663
2664out0:
2665 *stat = 0;
2666 return 0;
2667
2668error0:
2669 return error;
2670
2671error1:
2672 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
2673 return error;
2674}
2675
2676/*
2677 * Split cur/level block in half.
2678 * Return new block number and the key to its first
2679 * record (to be inserted into parent).
2680 */
2681STATIC int /* error */
2682__xfs_btree_split(
2683 struct xfs_btree_cur *cur,
2684 int level,
2685 union xfs_btree_ptr *ptrp,
2686 union xfs_btree_key *key,
2687 struct xfs_btree_cur **curp,
2688 int *stat) /* success/failure */
2689{
2690 union xfs_btree_ptr lptr; /* left sibling block ptr */
2691 struct xfs_buf *lbp; /* left buffer pointer */
2692 struct xfs_btree_block *left; /* left btree block */
2693 union xfs_btree_ptr rptr; /* right sibling block ptr */
2694 struct xfs_buf *rbp; /* right buffer pointer */
2695 struct xfs_btree_block *right; /* right btree block */
2696 union xfs_btree_ptr rrptr; /* right-right sibling ptr */
2697 struct xfs_buf *rrbp; /* right-right buffer pointer */
2698 struct xfs_btree_block *rrblock; /* right-right btree block */
2699 int lrecs;
2700 int rrecs;
2701 int src_index;
2702 int error; /* error return value */
2703 int i;
2704
2705 XFS_BTREE_STATS_INC(cur, split);
2706
2707 /* Set up left block (current one). */
2708 left = xfs_btree_get_block(cur, level, &lbp);
2709
2710#ifdef DEBUG
2711 error = xfs_btree_check_block(cur, left, level, lbp);
2712 if (error)
2713 goto error0;
2714#endif
2715
2716 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2717
2718 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2719 error = cur->bc_ops->alloc_block(cur, &lptr, &rptr, stat);
2720 if (error)
2721 goto error0;
2722 if (*stat == 0)
2723 goto out0;
2724 XFS_BTREE_STATS_INC(cur, alloc);
2725
2726 /* Set up the new block as "right". */
2727 error = xfs_btree_get_buf_block(cur, &rptr, &right, &rbp);
2728 if (error)
2729 goto error0;
2730
2731 /* Fill in the btree header for the new right block. */
2732 xfs_btree_init_block_cur(cur, rbp, xfs_btree_get_level(left), 0);
2733
2734 /*
2735 * Split the entries between the old and the new block evenly.
2736 * Make sure that if there's an odd number of entries now, that
2737 * each new block will have the same number of entries.
2738 */
2739 lrecs = xfs_btree_get_numrecs(left);
2740 rrecs = lrecs / 2;
2741 if ((lrecs & 1) && cur->bc_levels[level].ptr <= rrecs + 1)
2742 rrecs++;
2743 src_index = (lrecs - rrecs + 1);
2744
2745 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2746
2747 /* Adjust numrecs for the later get_*_keys() calls. */
2748 lrecs -= rrecs;
2749 xfs_btree_set_numrecs(left, lrecs);
2750 xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs);
2751
2752 /*
2753 * Copy btree block entries from the left block over to the
2754 * new block, the right. Update the right block and log the
2755 * changes.
2756 */
2757 if (level > 0) {
2758 /* It's a non-leaf. Move keys and pointers. */
2759 union xfs_btree_key *lkp; /* left btree key */
2760 union xfs_btree_ptr *lpp; /* left address pointer */
2761 union xfs_btree_key *rkp; /* right btree key */
2762 union xfs_btree_ptr *rpp; /* right address pointer */
2763
2764 lkp = xfs_btree_key_addr(cur, src_index, left);
2765 lpp = xfs_btree_ptr_addr(cur, src_index, left);
2766 rkp = xfs_btree_key_addr(cur, 1, right);
2767 rpp = xfs_btree_ptr_addr(cur, 1, right);
2768
2769 for (i = src_index; i < rrecs; i++) {
2770 error = xfs_btree_debug_check_ptr(cur, lpp, i, level);
2771 if (error)
2772 goto error0;
2773 }
2774
2775 /* Copy the keys & pointers to the new block. */
2776 xfs_btree_copy_keys(cur, rkp, lkp, rrecs);
2777 xfs_btree_copy_ptrs(cur, rpp, lpp, rrecs);
2778
2779 xfs_btree_log_keys(cur, rbp, 1, rrecs);
2780 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2781
2782 /* Stash the keys of the new block for later insertion. */
2783 xfs_btree_get_node_keys(cur, right, key);
2784 } else {
2785 /* It's a leaf. Move records. */
2786 union xfs_btree_rec *lrp; /* left record pointer */
2787 union xfs_btree_rec *rrp; /* right record pointer */
2788
2789 lrp = xfs_btree_rec_addr(cur, src_index, left);
2790 rrp = xfs_btree_rec_addr(cur, 1, right);
2791
2792 /* Copy records to the new block. */
2793 xfs_btree_copy_recs(cur, rrp, lrp, rrecs);
2794 xfs_btree_log_recs(cur, rbp, 1, rrecs);
2795
2796 /* Stash the keys of the new block for later insertion. */
2797 xfs_btree_get_leaf_keys(cur, right, key);
2798 }
2799
2800 /*
2801 * Find the left block number by looking in the buffer.
2802 * Adjust sibling pointers.
2803 */
2804 xfs_btree_get_sibling(cur, left, &rrptr, XFS_BB_RIGHTSIB);
2805 xfs_btree_set_sibling(cur, right, &rrptr, XFS_BB_RIGHTSIB);
2806 xfs_btree_set_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2807 xfs_btree_set_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2808
2809 xfs_btree_log_block(cur, rbp, XFS_BB_ALL_BITS);
2810 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
2811
2812 /*
2813 * If there's a block to the new block's right, make that block
2814 * point back to right instead of to left.
2815 */
2816 if (!xfs_btree_ptr_is_null(cur, &rrptr)) {
2817 error = xfs_btree_read_buf_block(cur, &rrptr,
2818 0, &rrblock, &rrbp);
2819 if (error)
2820 goto error0;
2821 xfs_btree_set_sibling(cur, rrblock, &rptr, XFS_BB_LEFTSIB);
2822 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
2823 }
2824
2825 /* Update the parent high keys of the left block, if needed. */
2826 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2827 error = xfs_btree_update_keys(cur, level);
2828 if (error)
2829 goto error0;
2830 }
2831
2832 /*
2833 * If the cursor is really in the right block, move it there.
2834 * If it's just pointing past the last entry in left, then we'll
2835 * insert there, so don't change anything in that case.
2836 */
2837 if (cur->bc_levels[level].ptr > lrecs + 1) {
2838 xfs_btree_setbuf(cur, level, rbp);
2839 cur->bc_levels[level].ptr -= lrecs;
2840 }
2841 /*
2842 * If there are more levels, we'll need another cursor which refers
2843 * the right block, no matter where this cursor was.
2844 */
2845 if (level + 1 < cur->bc_nlevels) {
2846 error = xfs_btree_dup_cursor(cur, curp);
2847 if (error)
2848 goto error0;
2849 (*curp)->bc_levels[level + 1].ptr++;
2850 }
2851 *ptrp = rptr;
2852 *stat = 1;
2853 return 0;
2854out0:
2855 *stat = 0;
2856 return 0;
2857
2858error0:
2859 return error;
2860}
2861
2862#ifdef __KERNEL__
2863struct xfs_btree_split_args {
2864 struct xfs_btree_cur *cur;
2865 int level;
2866 union xfs_btree_ptr *ptrp;
2867 union xfs_btree_key *key;
2868 struct xfs_btree_cur **curp;
2869 int *stat; /* success/failure */
2870 int result;
2871 bool kswapd; /* allocation in kswapd context */
2872 struct completion *done;
2873 struct work_struct work;
2874};
2875
2876/*
2877 * Stack switching interfaces for allocation
2878 */
2879static void
2880xfs_btree_split_worker(
2881 struct work_struct *work)
2882{
2883 struct xfs_btree_split_args *args = container_of(work,
2884 struct xfs_btree_split_args, work);
2885 unsigned long pflags;
2886 unsigned long new_pflags = 0;
2887
2888 /*
2889 * we are in a transaction context here, but may also be doing work
2890 * in kswapd context, and hence we may need to inherit that state
2891 * temporarily to ensure that we don't block waiting for memory reclaim
2892 * in any way.
2893 */
2894 if (args->kswapd)
2895 new_pflags |= PF_MEMALLOC | PF_KSWAPD;
2896
2897 current_set_flags_nested(&pflags, new_pflags);
2898 xfs_trans_set_context(args->cur->bc_tp);
2899
2900 args->result = __xfs_btree_split(args->cur, args->level, args->ptrp,
2901 args->key, args->curp, args->stat);
2902
2903 xfs_trans_clear_context(args->cur->bc_tp);
2904 current_restore_flags_nested(&pflags, new_pflags);
2905
2906 /*
2907 * Do not access args after complete() has run here. We don't own args
2908 * and the owner may run and free args before we return here.
2909 */
2910 complete(args->done);
2911
2912}
2913
2914/*
2915 * BMBT split requests often come in with little stack to work on so we push
2916 * them off to a worker thread so there is lots of stack to use. For the other
2917 * btree types, just call directly to avoid the context switch overhead here.
2918 *
2919 * Care must be taken here - the work queue rescuer thread introduces potential
2920 * AGF <> worker queue deadlocks if the BMBT block allocation has to lock new
2921 * AGFs to allocate blocks. A task being run by the rescuer could attempt to
2922 * lock an AGF that is already locked by a task queued to run by the rescuer,
2923 * resulting in an ABBA deadlock as the rescuer cannot run the lock holder to
2924 * release it until the current thread it is running gains the lock.
2925 *
2926 * To avoid this issue, we only ever queue BMBT splits that don't have an AGF
2927 * already locked to allocate from. The only place that doesn't hold an AGF
2928 * locked is unwritten extent conversion at IO completion, but that has already
2929 * been offloaded to a worker thread and hence has no stack consumption issues
2930 * we have to worry about.
2931 */
2932STATIC int /* error */
2933xfs_btree_split(
2934 struct xfs_btree_cur *cur,
2935 int level,
2936 union xfs_btree_ptr *ptrp,
2937 union xfs_btree_key *key,
2938 struct xfs_btree_cur **curp,
2939 int *stat) /* success/failure */
2940{
2941 struct xfs_btree_split_args args;
2942 DECLARE_COMPLETION_ONSTACK(done);
2943
2944 if (cur->bc_btnum != XFS_BTNUM_BMAP ||
2945 cur->bc_tp->t_highest_agno == NULLAGNUMBER)
2946 return __xfs_btree_split(cur, level, ptrp, key, curp, stat);
2947
2948 args.cur = cur;
2949 args.level = level;
2950 args.ptrp = ptrp;
2951 args.key = key;
2952 args.curp = curp;
2953 args.stat = stat;
2954 args.done = &done;
2955 args.kswapd = current_is_kswapd();
2956 INIT_WORK_ONSTACK(&args.work, xfs_btree_split_worker);
2957 queue_work(xfs_alloc_wq, &args.work);
2958 wait_for_completion(&done);
2959 destroy_work_on_stack(&args.work);
2960 return args.result;
2961}
2962#else
2963#define xfs_btree_split __xfs_btree_split
2964#endif /* __KERNEL__ */
2965
2966
2967/*
2968 * Copy the old inode root contents into a real block and make the
2969 * broot point to it.
2970 */
2971int /* error */
2972xfs_btree_new_iroot(
2973 struct xfs_btree_cur *cur, /* btree cursor */
2974 int *logflags, /* logging flags for inode */
2975 int *stat) /* return status - 0 fail */
2976{
2977 struct xfs_buf *cbp; /* buffer for cblock */
2978 struct xfs_btree_block *block; /* btree block */
2979 struct xfs_btree_block *cblock; /* child btree block */
2980 union xfs_btree_key *ckp; /* child key pointer */
2981 union xfs_btree_ptr *cpp; /* child ptr pointer */
2982 union xfs_btree_key *kp; /* pointer to btree key */
2983 union xfs_btree_ptr *pp; /* pointer to block addr */
2984 union xfs_btree_ptr nptr; /* new block addr */
2985 int level; /* btree level */
2986 int error; /* error return code */
2987 int i; /* loop counter */
2988
2989 XFS_BTREE_STATS_INC(cur, newroot);
2990
2991 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
2992
2993 level = cur->bc_nlevels - 1;
2994
2995 block = xfs_btree_get_iroot(cur);
2996 pp = xfs_btree_ptr_addr(cur, 1, block);
2997
2998 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2999 error = cur->bc_ops->alloc_block(cur, pp, &nptr, stat);
3000 if (error)
3001 goto error0;
3002 if (*stat == 0)
3003 return 0;
3004
3005 XFS_BTREE_STATS_INC(cur, alloc);
3006
3007 /* Copy the root into a real block. */
3008 error = xfs_btree_get_buf_block(cur, &nptr, &cblock, &cbp);
3009 if (error)
3010 goto error0;
3011
3012 /*
3013 * we can't just memcpy() the root in for CRC enabled btree blocks.
3014 * In that case have to also ensure the blkno remains correct
3015 */
3016 memcpy(cblock, block, xfs_btree_block_len(cur));
3017 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) {
3018 __be64 bno = cpu_to_be64(xfs_buf_daddr(cbp));
3019 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
3020 cblock->bb_u.l.bb_blkno = bno;
3021 else
3022 cblock->bb_u.s.bb_blkno = bno;
3023 }
3024
3025 be16_add_cpu(&block->bb_level, 1);
3026 xfs_btree_set_numrecs(block, 1);
3027 cur->bc_nlevels++;
3028 ASSERT(cur->bc_nlevels <= cur->bc_maxlevels);
3029 cur->bc_levels[level + 1].ptr = 1;
3030
3031 kp = xfs_btree_key_addr(cur, 1, block);
3032 ckp = xfs_btree_key_addr(cur, 1, cblock);
3033 xfs_btree_copy_keys(cur, ckp, kp, xfs_btree_get_numrecs(cblock));
3034
3035 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
3036 for (i = 0; i < be16_to_cpu(cblock->bb_numrecs); i++) {
3037 error = xfs_btree_debug_check_ptr(cur, pp, i, level);
3038 if (error)
3039 goto error0;
3040 }
3041
3042 xfs_btree_copy_ptrs(cur, cpp, pp, xfs_btree_get_numrecs(cblock));
3043
3044 error = xfs_btree_debug_check_ptr(cur, &nptr, 0, level);
3045 if (error)
3046 goto error0;
3047
3048 xfs_btree_copy_ptrs(cur, pp, &nptr, 1);
3049
3050 xfs_iroot_realloc(cur->bc_ino.ip,
3051 1 - xfs_btree_get_numrecs(cblock),
3052 cur->bc_ino.whichfork);
3053
3054 xfs_btree_setbuf(cur, level, cbp);
3055
3056 /*
3057 * Do all this logging at the end so that
3058 * the root is at the right level.
3059 */
3060 xfs_btree_log_block(cur, cbp, XFS_BB_ALL_BITS);
3061 xfs_btree_log_keys(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
3062 xfs_btree_log_ptrs(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
3063
3064 *logflags |=
3065 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_ino.whichfork);
3066 *stat = 1;
3067 return 0;
3068error0:
3069 return error;
3070}
3071
3072/*
3073 * Allocate a new root block, fill it in.
3074 */
3075STATIC int /* error */
3076xfs_btree_new_root(
3077 struct xfs_btree_cur *cur, /* btree cursor */
3078 int *stat) /* success/failure */
3079{
3080 struct xfs_btree_block *block; /* one half of the old root block */
3081 struct xfs_buf *bp; /* buffer containing block */
3082 int error; /* error return value */
3083 struct xfs_buf *lbp; /* left buffer pointer */
3084 struct xfs_btree_block *left; /* left btree block */
3085 struct xfs_buf *nbp; /* new (root) buffer */
3086 struct xfs_btree_block *new; /* new (root) btree block */
3087 int nptr; /* new value for key index, 1 or 2 */
3088 struct xfs_buf *rbp; /* right buffer pointer */
3089 struct xfs_btree_block *right; /* right btree block */
3090 union xfs_btree_ptr rptr;
3091 union xfs_btree_ptr lptr;
3092
3093 XFS_BTREE_STATS_INC(cur, newroot);
3094
3095 /* initialise our start point from the cursor */
3096 cur->bc_ops->init_ptr_from_cur(cur, &rptr);
3097
3098 /* Allocate the new block. If we can't do it, we're toast. Give up. */
3099 error = cur->bc_ops->alloc_block(cur, &rptr, &lptr, stat);
3100 if (error)
3101 goto error0;
3102 if (*stat == 0)
3103 goto out0;
3104 XFS_BTREE_STATS_INC(cur, alloc);
3105
3106 /* Set up the new block. */
3107 error = xfs_btree_get_buf_block(cur, &lptr, &new, &nbp);
3108 if (error)
3109 goto error0;
3110
3111 /* Set the root in the holding structure increasing the level by 1. */
3112 cur->bc_ops->set_root(cur, &lptr, 1);
3113
3114 /*
3115 * At the previous root level there are now two blocks: the old root,
3116 * and the new block generated when it was split. We don't know which
3117 * one the cursor is pointing at, so we set up variables "left" and
3118 * "right" for each case.
3119 */
3120 block = xfs_btree_get_block(cur, cur->bc_nlevels - 1, &bp);
3121
3122#ifdef DEBUG
3123 error = xfs_btree_check_block(cur, block, cur->bc_nlevels - 1, bp);
3124 if (error)
3125 goto error0;
3126#endif
3127
3128 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
3129 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
3130 /* Our block is left, pick up the right block. */
3131 lbp = bp;
3132 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
3133 left = block;
3134 error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
3135 if (error)
3136 goto error0;
3137 bp = rbp;
3138 nptr = 1;
3139 } else {
3140 /* Our block is right, pick up the left block. */
3141 rbp = bp;
3142 xfs_btree_buf_to_ptr(cur, rbp, &rptr);
3143 right = block;
3144 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
3145 error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
3146 if (error)
3147 goto error0;
3148 bp = lbp;
3149 nptr = 2;
3150 }
3151
3152 /* Fill in the new block's btree header and log it. */
3153 xfs_btree_init_block_cur(cur, nbp, cur->bc_nlevels, 2);
3154 xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS);
3155 ASSERT(!xfs_btree_ptr_is_null(cur, &lptr) &&
3156 !xfs_btree_ptr_is_null(cur, &rptr));
3157
3158 /* Fill in the key data in the new root. */
3159 if (xfs_btree_get_level(left) > 0) {
3160 /*
3161 * Get the keys for the left block's keys and put them directly
3162 * in the parent block. Do the same for the right block.
3163 */
3164 xfs_btree_get_node_keys(cur, left,
3165 xfs_btree_key_addr(cur, 1, new));
3166 xfs_btree_get_node_keys(cur, right,
3167 xfs_btree_key_addr(cur, 2, new));
3168 } else {
3169 /*
3170 * Get the keys for the left block's records and put them
3171 * directly in the parent block. Do the same for the right
3172 * block.
3173 */
3174 xfs_btree_get_leaf_keys(cur, left,
3175 xfs_btree_key_addr(cur, 1, new));
3176 xfs_btree_get_leaf_keys(cur, right,
3177 xfs_btree_key_addr(cur, 2, new));
3178 }
3179 xfs_btree_log_keys(cur, nbp, 1, 2);
3180
3181 /* Fill in the pointer data in the new root. */
3182 xfs_btree_copy_ptrs(cur,
3183 xfs_btree_ptr_addr(cur, 1, new), &lptr, 1);
3184 xfs_btree_copy_ptrs(cur,
3185 xfs_btree_ptr_addr(cur, 2, new), &rptr, 1);
3186 xfs_btree_log_ptrs(cur, nbp, 1, 2);
3187
3188 /* Fix up the cursor. */
3189 xfs_btree_setbuf(cur, cur->bc_nlevels, nbp);
3190 cur->bc_levels[cur->bc_nlevels].ptr = nptr;
3191 cur->bc_nlevels++;
3192 ASSERT(cur->bc_nlevels <= cur->bc_maxlevels);
3193 *stat = 1;
3194 return 0;
3195error0:
3196 return error;
3197out0:
3198 *stat = 0;
3199 return 0;
3200}
3201
3202STATIC int
3203xfs_btree_make_block_unfull(
3204 struct xfs_btree_cur *cur, /* btree cursor */
3205 int level, /* btree level */
3206 int numrecs,/* # of recs in block */
3207 int *oindex,/* old tree index */
3208 int *index, /* new tree index */
3209 union xfs_btree_ptr *nptr, /* new btree ptr */
3210 struct xfs_btree_cur **ncur, /* new btree cursor */
3211 union xfs_btree_key *key, /* key of new block */
3212 int *stat)
3213{
3214 int error = 0;
3215
3216 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
3217 level == cur->bc_nlevels - 1) {
3218 struct xfs_inode *ip = cur->bc_ino.ip;
3219
3220 if (numrecs < cur->bc_ops->get_dmaxrecs(cur, level)) {
3221 /* A root block that can be made bigger. */
3222 xfs_iroot_realloc(ip, 1, cur->bc_ino.whichfork);
3223 *stat = 1;
3224 } else {
3225 /* A root block that needs replacing */
3226 int logflags = 0;
3227
3228 error = xfs_btree_new_iroot(cur, &logflags, stat);
3229 if (error || *stat == 0)
3230 return error;
3231
3232 xfs_trans_log_inode(cur->bc_tp, ip, logflags);
3233 }
3234
3235 return 0;
3236 }
3237
3238 /* First, try shifting an entry to the right neighbor. */
3239 error = xfs_btree_rshift(cur, level, stat);
3240 if (error || *stat)
3241 return error;
3242
3243 /* Next, try shifting an entry to the left neighbor. */
3244 error = xfs_btree_lshift(cur, level, stat);
3245 if (error)
3246 return error;
3247
3248 if (*stat) {
3249 *oindex = *index = cur->bc_levels[level].ptr;
3250 return 0;
3251 }
3252
3253 /*
3254 * Next, try splitting the current block in half.
3255 *
3256 * If this works we have to re-set our variables because we
3257 * could be in a different block now.
3258 */
3259 error = xfs_btree_split(cur, level, nptr, key, ncur, stat);
3260 if (error || *stat == 0)
3261 return error;
3262
3263
3264 *index = cur->bc_levels[level].ptr;
3265 return 0;
3266}
3267
3268/*
3269 * Insert one record/level. Return information to the caller
3270 * allowing the next level up to proceed if necessary.
3271 */
3272STATIC int
3273xfs_btree_insrec(
3274 struct xfs_btree_cur *cur, /* btree cursor */
3275 int level, /* level to insert record at */
3276 union xfs_btree_ptr *ptrp, /* i/o: block number inserted */
3277 union xfs_btree_rec *rec, /* record to insert */
3278 union xfs_btree_key *key, /* i/o: block key for ptrp */
3279 struct xfs_btree_cur **curp, /* output: new cursor replacing cur */
3280 int *stat) /* success/failure */
3281{
3282 struct xfs_btree_block *block; /* btree block */
3283 struct xfs_buf *bp; /* buffer for block */
3284 union xfs_btree_ptr nptr; /* new block ptr */
3285 struct xfs_btree_cur *ncur = NULL; /* new btree cursor */
3286 union xfs_btree_key nkey; /* new block key */
3287 union xfs_btree_key *lkey;
3288 int optr; /* old key/record index */
3289 int ptr; /* key/record index */
3290 int numrecs;/* number of records */
3291 int error; /* error return value */
3292 int i;
3293 xfs_daddr_t old_bn;
3294
3295 ncur = NULL;
3296 lkey = &nkey;
3297
3298 /*
3299 * If we have an external root pointer, and we've made it to the
3300 * root level, allocate a new root block and we're done.
3301 */
3302 if (!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
3303 (level >= cur->bc_nlevels)) {
3304 error = xfs_btree_new_root(cur, stat);
3305 xfs_btree_set_ptr_null(cur, ptrp);
3306
3307 return error;
3308 }
3309
3310 /* If we're off the left edge, return failure. */
3311 ptr = cur->bc_levels[level].ptr;
3312 if (ptr == 0) {
3313 *stat = 0;
3314 return 0;
3315 }
3316
3317 optr = ptr;
3318
3319 XFS_BTREE_STATS_INC(cur, insrec);
3320
3321 /* Get pointers to the btree buffer and block. */
3322 block = xfs_btree_get_block(cur, level, &bp);
3323 old_bn = bp ? xfs_buf_daddr(bp) : XFS_BUF_DADDR_NULL;
3324 numrecs = xfs_btree_get_numrecs(block);
3325
3326#ifdef DEBUG
3327 error = xfs_btree_check_block(cur, block, level, bp);
3328 if (error)
3329 goto error0;
3330
3331 /* Check that the new entry is being inserted in the right place. */
3332 if (ptr <= numrecs) {
3333 if (level == 0) {
3334 ASSERT(cur->bc_ops->recs_inorder(cur, rec,
3335 xfs_btree_rec_addr(cur, ptr, block)));
3336 } else {
3337 ASSERT(cur->bc_ops->keys_inorder(cur, key,
3338 xfs_btree_key_addr(cur, ptr, block)));
3339 }
3340 }
3341#endif
3342
3343 /*
3344 * If the block is full, we can't insert the new entry until we
3345 * make the block un-full.
3346 */
3347 xfs_btree_set_ptr_null(cur, &nptr);
3348 if (numrecs == cur->bc_ops->get_maxrecs(cur, level)) {
3349 error = xfs_btree_make_block_unfull(cur, level, numrecs,
3350 &optr, &ptr, &nptr, &ncur, lkey, stat);
3351 if (error || *stat == 0)
3352 goto error0;
3353 }
3354
3355 /*
3356 * The current block may have changed if the block was
3357 * previously full and we have just made space in it.
3358 */
3359 block = xfs_btree_get_block(cur, level, &bp);
3360 numrecs = xfs_btree_get_numrecs(block);
3361
3362#ifdef DEBUG
3363 error = xfs_btree_check_block(cur, block, level, bp);
3364 if (error)
3365 goto error0;
3366#endif
3367
3368 /*
3369 * At this point we know there's room for our new entry in the block
3370 * we're pointing at.
3371 */
3372 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr + 1);
3373
3374 if (level > 0) {
3375 /* It's a nonleaf. make a hole in the keys and ptrs */
3376 union xfs_btree_key *kp;
3377 union xfs_btree_ptr *pp;
3378
3379 kp = xfs_btree_key_addr(cur, ptr, block);
3380 pp = xfs_btree_ptr_addr(cur, ptr, block);
3381
3382 for (i = numrecs - ptr; i >= 0; i--) {
3383 error = xfs_btree_debug_check_ptr(cur, pp, i, level);
3384 if (error)
3385 goto error0;
3386 }
3387
3388 xfs_btree_shift_keys(cur, kp, 1, numrecs - ptr + 1);
3389 xfs_btree_shift_ptrs(cur, pp, 1, numrecs - ptr + 1);
3390
3391 error = xfs_btree_debug_check_ptr(cur, ptrp, 0, level);
3392 if (error)
3393 goto error0;
3394
3395 /* Now put the new data in, bump numrecs and log it. */
3396 xfs_btree_copy_keys(cur, kp, key, 1);
3397 xfs_btree_copy_ptrs(cur, pp, ptrp, 1);
3398 numrecs++;
3399 xfs_btree_set_numrecs(block, numrecs);
3400 xfs_btree_log_ptrs(cur, bp, ptr, numrecs);
3401 xfs_btree_log_keys(cur, bp, ptr, numrecs);
3402#ifdef DEBUG
3403 if (ptr < numrecs) {
3404 ASSERT(cur->bc_ops->keys_inorder(cur, kp,
3405 xfs_btree_key_addr(cur, ptr + 1, block)));
3406 }
3407#endif
3408 } else {
3409 /* It's a leaf. make a hole in the records */
3410 union xfs_btree_rec *rp;
3411
3412 rp = xfs_btree_rec_addr(cur, ptr, block);
3413
3414 xfs_btree_shift_recs(cur, rp, 1, numrecs - ptr + 1);
3415
3416 /* Now put the new data in, bump numrecs and log it. */
3417 xfs_btree_copy_recs(cur, rp, rec, 1);
3418 xfs_btree_set_numrecs(block, ++numrecs);
3419 xfs_btree_log_recs(cur, bp, ptr, numrecs);
3420#ifdef DEBUG
3421 if (ptr < numrecs) {
3422 ASSERT(cur->bc_ops->recs_inorder(cur, rp,
3423 xfs_btree_rec_addr(cur, ptr + 1, block)));
3424 }
3425#endif
3426 }
3427
3428 /* Log the new number of records in the btree header. */
3429 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
3430
3431 /*
3432 * If we just inserted into a new tree block, we have to
3433 * recalculate nkey here because nkey is out of date.
3434 *
3435 * Otherwise we're just updating an existing block (having shoved
3436 * some records into the new tree block), so use the regular key
3437 * update mechanism.
3438 */
3439 if (bp && xfs_buf_daddr(bp) != old_bn) {
3440 xfs_btree_get_keys(cur, block, lkey);
3441 } else if (xfs_btree_needs_key_update(cur, optr)) {
3442 error = xfs_btree_update_keys(cur, level);
3443 if (error)
3444 goto error0;
3445 }
3446
3447 /*
3448 * If we are tracking the last record in the tree and
3449 * we are at the far right edge of the tree, update it.
3450 */
3451 if (xfs_btree_is_lastrec(cur, block, level)) {
3452 cur->bc_ops->update_lastrec(cur, block, rec,
3453 ptr, LASTREC_INSREC);
3454 }
3455
3456 /*
3457 * Return the new block number, if any.
3458 * If there is one, give back a record value and a cursor too.
3459 */
3460 *ptrp = nptr;
3461 if (!xfs_btree_ptr_is_null(cur, &nptr)) {
3462 xfs_btree_copy_keys(cur, key, lkey, 1);
3463 *curp = ncur;
3464 }
3465
3466 *stat = 1;
3467 return 0;
3468
3469error0:
3470 if (ncur)
3471 xfs_btree_del_cursor(ncur, error);
3472 return error;
3473}
3474
3475/*
3476 * Insert the record at the point referenced by cur.
3477 *
3478 * A multi-level split of the tree on insert will invalidate the original
3479 * cursor. All callers of this function should assume that the cursor is
3480 * no longer valid and revalidate it.
3481 */
3482int
3483xfs_btree_insert(
3484 struct xfs_btree_cur *cur,
3485 int *stat)
3486{
3487 int error; /* error return value */
3488 int i; /* result value, 0 for failure */
3489 int level; /* current level number in btree */
3490 union xfs_btree_ptr nptr; /* new block number (split result) */
3491 struct xfs_btree_cur *ncur; /* new cursor (split result) */
3492 struct xfs_btree_cur *pcur; /* previous level's cursor */
3493 union xfs_btree_key bkey; /* key of block to insert */
3494 union xfs_btree_key *key;
3495 union xfs_btree_rec rec; /* record to insert */
3496
3497 level = 0;
3498 ncur = NULL;
3499 pcur = cur;
3500 key = &bkey;
3501
3502 xfs_btree_set_ptr_null(cur, &nptr);
3503
3504 /* Make a key out of the record data to be inserted, and save it. */
3505 cur->bc_ops->init_rec_from_cur(cur, &rec);
3506 cur->bc_ops->init_key_from_rec(key, &rec);
3507
3508 /*
3509 * Loop going up the tree, starting at the leaf level.
3510 * Stop when we don't get a split block, that must mean that
3511 * the insert is finished with this level.
3512 */
3513 do {
3514 /*
3515 * Insert nrec/nptr into this level of the tree.
3516 * Note if we fail, nptr will be null.
3517 */
3518 error = xfs_btree_insrec(pcur, level, &nptr, &rec, key,
3519 &ncur, &i);
3520 if (error) {
3521 if (pcur != cur)
3522 xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR);
3523 goto error0;
3524 }
3525
3526 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
3527 error = -EFSCORRUPTED;
3528 goto error0;
3529 }
3530 level++;
3531
3532 /*
3533 * See if the cursor we just used is trash.
3534 * Can't trash the caller's cursor, but otherwise we should
3535 * if ncur is a new cursor or we're about to be done.
3536 */
3537 if (pcur != cur &&
3538 (ncur || xfs_btree_ptr_is_null(cur, &nptr))) {
3539 /* Save the state from the cursor before we trash it */
3540 if (cur->bc_ops->update_cursor)
3541 cur->bc_ops->update_cursor(pcur, cur);
3542 cur->bc_nlevels = pcur->bc_nlevels;
3543 xfs_btree_del_cursor(pcur, XFS_BTREE_NOERROR);
3544 }
3545 /* If we got a new cursor, switch to it. */
3546 if (ncur) {
3547 pcur = ncur;
3548 ncur = NULL;
3549 }
3550 } while (!xfs_btree_ptr_is_null(cur, &nptr));
3551
3552 *stat = i;
3553 return 0;
3554error0:
3555 return error;
3556}
3557
3558/*
3559 * Try to merge a non-leaf block back into the inode root.
3560 *
3561 * Note: the killroot names comes from the fact that we're effectively
3562 * killing the old root block. But because we can't just delete the
3563 * inode we have to copy the single block it was pointing to into the
3564 * inode.
3565 */
3566STATIC int
3567xfs_btree_kill_iroot(
3568 struct xfs_btree_cur *cur)
3569{
3570 int whichfork = cur->bc_ino.whichfork;
3571 struct xfs_inode *ip = cur->bc_ino.ip;
3572 struct xfs_ifork *ifp = xfs_ifork_ptr(ip, whichfork);
3573 struct xfs_btree_block *block;
3574 struct xfs_btree_block *cblock;
3575 union xfs_btree_key *kp;
3576 union xfs_btree_key *ckp;
3577 union xfs_btree_ptr *pp;
3578 union xfs_btree_ptr *cpp;
3579 struct xfs_buf *cbp;
3580 int level;
3581 int index;
3582 int numrecs;
3583 int error;
3584#ifdef DEBUG
3585 union xfs_btree_ptr ptr;
3586#endif
3587 int i;
3588
3589 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
3590 ASSERT(cur->bc_nlevels > 1);
3591
3592 /*
3593 * Don't deal with the root block needs to be a leaf case.
3594 * We're just going to turn the thing back into extents anyway.
3595 */
3596 level = cur->bc_nlevels - 1;
3597 if (level == 1)
3598 goto out0;
3599
3600 /*
3601 * Give up if the root has multiple children.
3602 */
3603 block = xfs_btree_get_iroot(cur);
3604 if (xfs_btree_get_numrecs(block) != 1)
3605 goto out0;
3606
3607 cblock = xfs_btree_get_block(cur, level - 1, &cbp);
3608 numrecs = xfs_btree_get_numrecs(cblock);
3609
3610 /*
3611 * Only do this if the next level will fit.
3612 * Then the data must be copied up to the inode,
3613 * instead of freeing the root you free the next level.
3614 */
3615 if (numrecs > cur->bc_ops->get_dmaxrecs(cur, level))
3616 goto out0;
3617
3618 XFS_BTREE_STATS_INC(cur, killroot);
3619
3620#ifdef DEBUG
3621 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
3622 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
3623 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
3624 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
3625#endif
3626
3627 index = numrecs - cur->bc_ops->get_maxrecs(cur, level);
3628 if (index) {
3629 xfs_iroot_realloc(cur->bc_ino.ip, index,
3630 cur->bc_ino.whichfork);
3631 block = ifp->if_broot;
3632 }
3633
3634 be16_add_cpu(&block->bb_numrecs, index);
3635 ASSERT(block->bb_numrecs == cblock->bb_numrecs);
3636
3637 kp = xfs_btree_key_addr(cur, 1, block);
3638 ckp = xfs_btree_key_addr(cur, 1, cblock);
3639 xfs_btree_copy_keys(cur, kp, ckp, numrecs);
3640
3641 pp = xfs_btree_ptr_addr(cur, 1, block);
3642 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
3643
3644 for (i = 0; i < numrecs; i++) {
3645 error = xfs_btree_debug_check_ptr(cur, cpp, i, level - 1);
3646 if (error)
3647 return error;
3648 }
3649
3650 xfs_btree_copy_ptrs(cur, pp, cpp, numrecs);
3651
3652 error = xfs_btree_free_block(cur, cbp);
3653 if (error)
3654 return error;
3655
3656 cur->bc_levels[level - 1].bp = NULL;
3657 be16_add_cpu(&block->bb_level, -1);
3658 xfs_trans_log_inode(cur->bc_tp, ip,
3659 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_ino.whichfork));
3660 cur->bc_nlevels--;
3661out0:
3662 return 0;
3663}
3664
3665/*
3666 * Kill the current root node, and replace it with it's only child node.
3667 */
3668STATIC int
3669xfs_btree_kill_root(
3670 struct xfs_btree_cur *cur,
3671 struct xfs_buf *bp,
3672 int level,
3673 union xfs_btree_ptr *newroot)
3674{
3675 int error;
3676
3677 XFS_BTREE_STATS_INC(cur, killroot);
3678
3679 /*
3680 * Update the root pointer, decreasing the level by 1 and then
3681 * free the old root.
3682 */
3683 cur->bc_ops->set_root(cur, newroot, -1);
3684
3685 error = xfs_btree_free_block(cur, bp);
3686 if (error)
3687 return error;
3688
3689 cur->bc_levels[level].bp = NULL;
3690 cur->bc_levels[level].ra = 0;
3691 cur->bc_nlevels--;
3692
3693 return 0;
3694}
3695
3696STATIC int
3697xfs_btree_dec_cursor(
3698 struct xfs_btree_cur *cur,
3699 int level,
3700 int *stat)
3701{
3702 int error;
3703 int i;
3704
3705 if (level > 0) {
3706 error = xfs_btree_decrement(cur, level, &i);
3707 if (error)
3708 return error;
3709 }
3710
3711 *stat = 1;
3712 return 0;
3713}
3714
3715/*
3716 * Single level of the btree record deletion routine.
3717 * Delete record pointed to by cur/level.
3718 * Remove the record from its block then rebalance the tree.
3719 * Return 0 for error, 1 for done, 2 to go on to the next level.
3720 */
3721STATIC int /* error */
3722xfs_btree_delrec(
3723 struct xfs_btree_cur *cur, /* btree cursor */
3724 int level, /* level removing record from */
3725 int *stat) /* fail/done/go-on */
3726{
3727 struct xfs_btree_block *block; /* btree block */
3728 union xfs_btree_ptr cptr; /* current block ptr */
3729 struct xfs_buf *bp; /* buffer for block */
3730 int error; /* error return value */
3731 int i; /* loop counter */
3732 union xfs_btree_ptr lptr; /* left sibling block ptr */
3733 struct xfs_buf *lbp; /* left buffer pointer */
3734 struct xfs_btree_block *left; /* left btree block */
3735 int lrecs = 0; /* left record count */
3736 int ptr; /* key/record index */
3737 union xfs_btree_ptr rptr; /* right sibling block ptr */
3738 struct xfs_buf *rbp; /* right buffer pointer */
3739 struct xfs_btree_block *right; /* right btree block */
3740 struct xfs_btree_block *rrblock; /* right-right btree block */
3741 struct xfs_buf *rrbp; /* right-right buffer pointer */
3742 int rrecs = 0; /* right record count */
3743 struct xfs_btree_cur *tcur; /* temporary btree cursor */
3744 int numrecs; /* temporary numrec count */
3745
3746 tcur = NULL;
3747
3748 /* Get the index of the entry being deleted, check for nothing there. */
3749 ptr = cur->bc_levels[level].ptr;
3750 if (ptr == 0) {
3751 *stat = 0;
3752 return 0;
3753 }
3754
3755 /* Get the buffer & block containing the record or key/ptr. */
3756 block = xfs_btree_get_block(cur, level, &bp);
3757 numrecs = xfs_btree_get_numrecs(block);
3758
3759#ifdef DEBUG
3760 error = xfs_btree_check_block(cur, block, level, bp);
3761 if (error)
3762 goto error0;
3763#endif
3764
3765 /* Fail if we're off the end of the block. */
3766 if (ptr > numrecs) {
3767 *stat = 0;
3768 return 0;
3769 }
3770
3771 XFS_BTREE_STATS_INC(cur, delrec);
3772 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr);
3773
3774 /* Excise the entries being deleted. */
3775 if (level > 0) {
3776 /* It's a nonleaf. operate on keys and ptrs */
3777 union xfs_btree_key *lkp;
3778 union xfs_btree_ptr *lpp;
3779
3780 lkp = xfs_btree_key_addr(cur, ptr + 1, block);
3781 lpp = xfs_btree_ptr_addr(cur, ptr + 1, block);
3782
3783 for (i = 0; i < numrecs - ptr; i++) {
3784 error = xfs_btree_debug_check_ptr(cur, lpp, i, level);
3785 if (error)
3786 goto error0;
3787 }
3788
3789 if (ptr < numrecs) {
3790 xfs_btree_shift_keys(cur, lkp, -1, numrecs - ptr);
3791 xfs_btree_shift_ptrs(cur, lpp, -1, numrecs - ptr);
3792 xfs_btree_log_keys(cur, bp, ptr, numrecs - 1);
3793 xfs_btree_log_ptrs(cur, bp, ptr, numrecs - 1);
3794 }
3795 } else {
3796 /* It's a leaf. operate on records */
3797 if (ptr < numrecs) {
3798 xfs_btree_shift_recs(cur,
3799 xfs_btree_rec_addr(cur, ptr + 1, block),
3800 -1, numrecs - ptr);
3801 xfs_btree_log_recs(cur, bp, ptr, numrecs - 1);
3802 }
3803 }
3804
3805 /*
3806 * Decrement and log the number of entries in the block.
3807 */
3808 xfs_btree_set_numrecs(block, --numrecs);
3809 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
3810
3811 /*
3812 * If we are tracking the last record in the tree and
3813 * we are at the far right edge of the tree, update it.
3814 */
3815 if (xfs_btree_is_lastrec(cur, block, level)) {
3816 cur->bc_ops->update_lastrec(cur, block, NULL,
3817 ptr, LASTREC_DELREC);
3818 }
3819
3820 /*
3821 * We're at the root level. First, shrink the root block in-memory.
3822 * Try to get rid of the next level down. If we can't then there's
3823 * nothing left to do.
3824 */
3825 if (level == cur->bc_nlevels - 1) {
3826 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3827 xfs_iroot_realloc(cur->bc_ino.ip, -1,
3828 cur->bc_ino.whichfork);
3829
3830 error = xfs_btree_kill_iroot(cur);
3831 if (error)
3832 goto error0;
3833
3834 error = xfs_btree_dec_cursor(cur, level, stat);
3835 if (error)
3836 goto error0;
3837 *stat = 1;
3838 return 0;
3839 }
3840
3841 /*
3842 * If this is the root level, and there's only one entry left,
3843 * and it's NOT the leaf level, then we can get rid of this
3844 * level.
3845 */
3846 if (numrecs == 1 && level > 0) {
3847 union xfs_btree_ptr *pp;
3848 /*
3849 * pp is still set to the first pointer in the block.
3850 * Make it the new root of the btree.
3851 */
3852 pp = xfs_btree_ptr_addr(cur, 1, block);
3853 error = xfs_btree_kill_root(cur, bp, level, pp);
3854 if (error)
3855 goto error0;
3856 } else if (level > 0) {
3857 error = xfs_btree_dec_cursor(cur, level, stat);
3858 if (error)
3859 goto error0;
3860 }
3861 *stat = 1;
3862 return 0;
3863 }
3864
3865 /*
3866 * If we deleted the leftmost entry in the block, update the
3867 * key values above us in the tree.
3868 */
3869 if (xfs_btree_needs_key_update(cur, ptr)) {
3870 error = xfs_btree_update_keys(cur, level);
3871 if (error)
3872 goto error0;
3873 }
3874
3875 /*
3876 * If the number of records remaining in the block is at least
3877 * the minimum, we're done.
3878 */
3879 if (numrecs >= cur->bc_ops->get_minrecs(cur, level)) {
3880 error = xfs_btree_dec_cursor(cur, level, stat);
3881 if (error)
3882 goto error0;
3883 return 0;
3884 }
3885
3886 /*
3887 * Otherwise, we have to move some records around to keep the
3888 * tree balanced. Look at the left and right sibling blocks to
3889 * see if we can re-balance by moving only one record.
3890 */
3891 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
3892 xfs_btree_get_sibling(cur, block, &lptr, XFS_BB_LEFTSIB);
3893
3894 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3895 /*
3896 * One child of root, need to get a chance to copy its contents
3897 * into the root and delete it. Can't go up to next level,
3898 * there's nothing to delete there.
3899 */
3900 if (xfs_btree_ptr_is_null(cur, &rptr) &&
3901 xfs_btree_ptr_is_null(cur, &lptr) &&
3902 level == cur->bc_nlevels - 2) {
3903 error = xfs_btree_kill_iroot(cur);
3904 if (!error)
3905 error = xfs_btree_dec_cursor(cur, level, stat);
3906 if (error)
3907 goto error0;
3908 return 0;
3909 }
3910 }
3911
3912 ASSERT(!xfs_btree_ptr_is_null(cur, &rptr) ||
3913 !xfs_btree_ptr_is_null(cur, &lptr));
3914
3915 /*
3916 * Duplicate the cursor so our btree manipulations here won't
3917 * disrupt the next level up.
3918 */
3919 error = xfs_btree_dup_cursor(cur, &tcur);
3920 if (error)
3921 goto error0;
3922
3923 /*
3924 * If there's a right sibling, see if it's ok to shift an entry
3925 * out of it.
3926 */
3927 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
3928 /*
3929 * Move the temp cursor to the last entry in the next block.
3930 * Actually any entry but the first would suffice.
3931 */
3932 i = xfs_btree_lastrec(tcur, level);
3933 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
3934 error = -EFSCORRUPTED;
3935 goto error0;
3936 }
3937
3938 error = xfs_btree_increment(tcur, level, &i);
3939 if (error)
3940 goto error0;
3941 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
3942 error = -EFSCORRUPTED;
3943 goto error0;
3944 }
3945
3946 i = xfs_btree_lastrec(tcur, level);
3947 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
3948 error = -EFSCORRUPTED;
3949 goto error0;
3950 }
3951
3952 /* Grab a pointer to the block. */
3953 right = xfs_btree_get_block(tcur, level, &rbp);
3954#ifdef DEBUG
3955 error = xfs_btree_check_block(tcur, right, level, rbp);
3956 if (error)
3957 goto error0;
3958#endif
3959 /* Grab the current block number, for future use. */
3960 xfs_btree_get_sibling(tcur, right, &cptr, XFS_BB_LEFTSIB);
3961
3962 /*
3963 * If right block is full enough so that removing one entry
3964 * won't make it too empty, and left-shifting an entry out
3965 * of right to us works, we're done.
3966 */
3967 if (xfs_btree_get_numrecs(right) - 1 >=
3968 cur->bc_ops->get_minrecs(tcur, level)) {
3969 error = xfs_btree_lshift(tcur, level, &i);
3970 if (error)
3971 goto error0;
3972 if (i) {
3973 ASSERT(xfs_btree_get_numrecs(block) >=
3974 cur->bc_ops->get_minrecs(tcur, level));
3975
3976 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3977 tcur = NULL;
3978
3979 error = xfs_btree_dec_cursor(cur, level, stat);
3980 if (error)
3981 goto error0;
3982 return 0;
3983 }
3984 }
3985
3986 /*
3987 * Otherwise, grab the number of records in right for
3988 * future reference, and fix up the temp cursor to point
3989 * to our block again (last record).
3990 */
3991 rrecs = xfs_btree_get_numrecs(right);
3992 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3993 i = xfs_btree_firstrec(tcur, level);
3994 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
3995 error = -EFSCORRUPTED;
3996 goto error0;
3997 }
3998
3999 error = xfs_btree_decrement(tcur, level, &i);
4000 if (error)
4001 goto error0;
4002 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
4003 error = -EFSCORRUPTED;
4004 goto error0;
4005 }
4006 }
4007 }
4008
4009 /*
4010 * If there's a left sibling, see if it's ok to shift an entry
4011 * out of it.
4012 */
4013 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
4014 /*
4015 * Move the temp cursor to the first entry in the
4016 * previous block.
4017 */
4018 i = xfs_btree_firstrec(tcur, level);
4019 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
4020 error = -EFSCORRUPTED;
4021 goto error0;
4022 }
4023
4024 error = xfs_btree_decrement(tcur, level, &i);
4025 if (error)
4026 goto error0;
4027 i = xfs_btree_firstrec(tcur, level);
4028 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
4029 error = -EFSCORRUPTED;
4030 goto error0;
4031 }
4032
4033 /* Grab a pointer to the block. */
4034 left = xfs_btree_get_block(tcur, level, &lbp);
4035#ifdef DEBUG
4036 error = xfs_btree_check_block(cur, left, level, lbp);
4037 if (error)
4038 goto error0;
4039#endif
4040 /* Grab the current block number, for future use. */
4041 xfs_btree_get_sibling(tcur, left, &cptr, XFS_BB_RIGHTSIB);
4042
4043 /*
4044 * If left block is full enough so that removing one entry
4045 * won't make it too empty, and right-shifting an entry out
4046 * of left to us works, we're done.
4047 */
4048 if (xfs_btree_get_numrecs(left) - 1 >=
4049 cur->bc_ops->get_minrecs(tcur, level)) {
4050 error = xfs_btree_rshift(tcur, level, &i);
4051 if (error)
4052 goto error0;
4053 if (i) {
4054 ASSERT(xfs_btree_get_numrecs(block) >=
4055 cur->bc_ops->get_minrecs(tcur, level));
4056 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
4057 tcur = NULL;
4058 if (level == 0)
4059 cur->bc_levels[0].ptr++;
4060
4061 *stat = 1;
4062 return 0;
4063 }
4064 }
4065
4066 /*
4067 * Otherwise, grab the number of records in right for
4068 * future reference.
4069 */
4070 lrecs = xfs_btree_get_numrecs(left);
4071 }
4072
4073 /* Delete the temp cursor, we're done with it. */
4074 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
4075 tcur = NULL;
4076
4077 /* If here, we need to do a join to keep the tree balanced. */
4078 ASSERT(!xfs_btree_ptr_is_null(cur, &cptr));
4079
4080 if (!xfs_btree_ptr_is_null(cur, &lptr) &&
4081 lrecs + xfs_btree_get_numrecs(block) <=
4082 cur->bc_ops->get_maxrecs(cur, level)) {
4083 /*
4084 * Set "right" to be the starting block,
4085 * "left" to be the left neighbor.
4086 */
4087 rptr = cptr;
4088 right = block;
4089 rbp = bp;
4090 error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
4091 if (error)
4092 goto error0;
4093
4094 /*
4095 * If that won't work, see if we can join with the right neighbor block.
4096 */
4097 } else if (!xfs_btree_ptr_is_null(cur, &rptr) &&
4098 rrecs + xfs_btree_get_numrecs(block) <=
4099 cur->bc_ops->get_maxrecs(cur, level)) {
4100 /*
4101 * Set "left" to be the starting block,
4102 * "right" to be the right neighbor.
4103 */
4104 lptr = cptr;
4105 left = block;
4106 lbp = bp;
4107 error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
4108 if (error)
4109 goto error0;
4110
4111 /*
4112 * Otherwise, we can't fix the imbalance.
4113 * Just return. This is probably a logic error, but it's not fatal.
4114 */
4115 } else {
4116 error = xfs_btree_dec_cursor(cur, level, stat);
4117 if (error)
4118 goto error0;
4119 return 0;
4120 }
4121
4122 rrecs = xfs_btree_get_numrecs(right);
4123 lrecs = xfs_btree_get_numrecs(left);
4124
4125 /*
4126 * We're now going to join "left" and "right" by moving all the stuff
4127 * in "right" to "left" and deleting "right".
4128 */
4129 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
4130 if (level > 0) {
4131 /* It's a non-leaf. Move keys and pointers. */
4132 union xfs_btree_key *lkp; /* left btree key */
4133 union xfs_btree_ptr *lpp; /* left address pointer */
4134 union xfs_btree_key *rkp; /* right btree key */
4135 union xfs_btree_ptr *rpp; /* right address pointer */
4136
4137 lkp = xfs_btree_key_addr(cur, lrecs + 1, left);
4138 lpp = xfs_btree_ptr_addr(cur, lrecs + 1, left);
4139 rkp = xfs_btree_key_addr(cur, 1, right);
4140 rpp = xfs_btree_ptr_addr(cur, 1, right);
4141
4142 for (i = 1; i < rrecs; i++) {
4143 error = xfs_btree_debug_check_ptr(cur, rpp, i, level);
4144 if (error)
4145 goto error0;
4146 }
4147
4148 xfs_btree_copy_keys(cur, lkp, rkp, rrecs);
4149 xfs_btree_copy_ptrs(cur, lpp, rpp, rrecs);
4150
4151 xfs_btree_log_keys(cur, lbp, lrecs + 1, lrecs + rrecs);
4152 xfs_btree_log_ptrs(cur, lbp, lrecs + 1, lrecs + rrecs);
4153 } else {
4154 /* It's a leaf. Move records. */
4155 union xfs_btree_rec *lrp; /* left record pointer */
4156 union xfs_btree_rec *rrp; /* right record pointer */
4157
4158 lrp = xfs_btree_rec_addr(cur, lrecs + 1, left);
4159 rrp = xfs_btree_rec_addr(cur, 1, right);
4160
4161 xfs_btree_copy_recs(cur, lrp, rrp, rrecs);
4162 xfs_btree_log_recs(cur, lbp, lrecs + 1, lrecs + rrecs);
4163 }
4164
4165 XFS_BTREE_STATS_INC(cur, join);
4166
4167 /*
4168 * Fix up the number of records and right block pointer in the
4169 * surviving block, and log it.
4170 */
4171 xfs_btree_set_numrecs(left, lrecs + rrecs);
4172 xfs_btree_get_sibling(cur, right, &cptr, XFS_BB_RIGHTSIB);
4173 xfs_btree_set_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
4174 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
4175
4176 /* If there is a right sibling, point it to the remaining block. */
4177 xfs_btree_get_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
4178 if (!xfs_btree_ptr_is_null(cur, &cptr)) {
4179 error = xfs_btree_read_buf_block(cur, &cptr, 0, &rrblock, &rrbp);
4180 if (error)
4181 goto error0;
4182 xfs_btree_set_sibling(cur, rrblock, &lptr, XFS_BB_LEFTSIB);
4183 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
4184 }
4185
4186 /* Free the deleted block. */
4187 error = xfs_btree_free_block(cur, rbp);
4188 if (error)
4189 goto error0;
4190
4191 /*
4192 * If we joined with the left neighbor, set the buffer in the
4193 * cursor to the left block, and fix up the index.
4194 */
4195 if (bp != lbp) {
4196 cur->bc_levels[level].bp = lbp;
4197 cur->bc_levels[level].ptr += lrecs;
4198 cur->bc_levels[level].ra = 0;
4199 }
4200 /*
4201 * If we joined with the right neighbor and there's a level above
4202 * us, increment the cursor at that level.
4203 */
4204 else if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) ||
4205 (level + 1 < cur->bc_nlevels)) {
4206 error = xfs_btree_increment(cur, level + 1, &i);
4207 if (error)
4208 goto error0;
4209 }
4210
4211 /*
4212 * Readjust the ptr at this level if it's not a leaf, since it's
4213 * still pointing at the deletion point, which makes the cursor
4214 * inconsistent. If this makes the ptr 0, the caller fixes it up.
4215 * We can't use decrement because it would change the next level up.
4216 */
4217 if (level > 0)
4218 cur->bc_levels[level].ptr--;
4219
4220 /*
4221 * We combined blocks, so we have to update the parent keys if the
4222 * btree supports overlapped intervals. However,
4223 * bc_levels[level + 1].ptr points to the old block so that the caller
4224 * knows which record to delete. Therefore, the caller must be savvy
4225 * enough to call updkeys for us if we return stat == 2. The other
4226 * exit points from this function don't require deletions further up
4227 * the tree, so they can call updkeys directly.
4228 */
4229
4230 /* Return value means the next level up has something to do. */
4231 *stat = 2;
4232 return 0;
4233
4234error0:
4235 if (tcur)
4236 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
4237 return error;
4238}
4239
4240/*
4241 * Delete the record pointed to by cur.
4242 * The cursor refers to the place where the record was (could be inserted)
4243 * when the operation returns.
4244 */
4245int /* error */
4246xfs_btree_delete(
4247 struct xfs_btree_cur *cur,
4248 int *stat) /* success/failure */
4249{
4250 int error; /* error return value */
4251 int level;
4252 int i;
4253 bool joined = false;
4254
4255 /*
4256 * Go up the tree, starting at leaf level.
4257 *
4258 * If 2 is returned then a join was done; go to the next level.
4259 * Otherwise we are done.
4260 */
4261 for (level = 0, i = 2; i == 2; level++) {
4262 error = xfs_btree_delrec(cur, level, &i);
4263 if (error)
4264 goto error0;
4265 if (i == 2)
4266 joined = true;
4267 }
4268
4269 /*
4270 * If we combined blocks as part of deleting the record, delrec won't
4271 * have updated the parent high keys so we have to do that here.
4272 */
4273 if (joined && (cur->bc_flags & XFS_BTREE_OVERLAPPING)) {
4274 error = xfs_btree_updkeys_force(cur, 0);
4275 if (error)
4276 goto error0;
4277 }
4278
4279 if (i == 0) {
4280 for (level = 1; level < cur->bc_nlevels; level++) {
4281 if (cur->bc_levels[level].ptr == 0) {
4282 error = xfs_btree_decrement(cur, level, &i);
4283 if (error)
4284 goto error0;
4285 break;
4286 }
4287 }
4288 }
4289
4290 *stat = i;
4291 return 0;
4292error0:
4293 return error;
4294}
4295
4296/*
4297 * Get the data from the pointed-to record.
4298 */
4299int /* error */
4300xfs_btree_get_rec(
4301 struct xfs_btree_cur *cur, /* btree cursor */
4302 union xfs_btree_rec **recp, /* output: btree record */
4303 int *stat) /* output: success/failure */
4304{
4305 struct xfs_btree_block *block; /* btree block */
4306 struct xfs_buf *bp; /* buffer pointer */
4307 int ptr; /* record number */
4308#ifdef DEBUG
4309 int error; /* error return value */
4310#endif
4311
4312 ptr = cur->bc_levels[0].ptr;
4313 block = xfs_btree_get_block(cur, 0, &bp);
4314
4315#ifdef DEBUG
4316 error = xfs_btree_check_block(cur, block, 0, bp);
4317 if (error)
4318 return error;
4319#endif
4320
4321 /*
4322 * Off the right end or left end, return failure.
4323 */
4324 if (ptr > xfs_btree_get_numrecs(block) || ptr <= 0) {
4325 *stat = 0;
4326 return 0;
4327 }
4328
4329 /*
4330 * Point to the record and extract its data.
4331 */
4332 *recp = xfs_btree_rec_addr(cur, ptr, block);
4333 *stat = 1;
4334 return 0;
4335}
4336
4337/* Visit a block in a btree. */
4338STATIC int
4339xfs_btree_visit_block(
4340 struct xfs_btree_cur *cur,
4341 int level,
4342 xfs_btree_visit_blocks_fn fn,
4343 void *data)
4344{
4345 struct xfs_btree_block *block;
4346 struct xfs_buf *bp;
4347 union xfs_btree_ptr rptr;
4348 int error;
4349
4350 /* do right sibling readahead */
4351 xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
4352 block = xfs_btree_get_block(cur, level, &bp);
4353
4354 /* process the block */
4355 error = fn(cur, level, data);
4356 if (error)
4357 return error;
4358
4359 /* now read rh sibling block for next iteration */
4360 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
4361 if (xfs_btree_ptr_is_null(cur, &rptr))
4362 return -ENOENT;
4363
4364 /*
4365 * We only visit blocks once in this walk, so we have to avoid the
4366 * internal xfs_btree_lookup_get_block() optimisation where it will
4367 * return the same block without checking if the right sibling points
4368 * back to us and creates a cyclic reference in the btree.
4369 */
4370 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
4371 if (be64_to_cpu(rptr.l) == XFS_DADDR_TO_FSB(cur->bc_mp,
4372 xfs_buf_daddr(bp)))
4373 return -EFSCORRUPTED;
4374 } else {
4375 if (be32_to_cpu(rptr.s) == xfs_daddr_to_agbno(cur->bc_mp,
4376 xfs_buf_daddr(bp)))
4377 return -EFSCORRUPTED;
4378 }
4379 return xfs_btree_lookup_get_block(cur, level, &rptr, &block);
4380}
4381
4382
4383/* Visit every block in a btree. */
4384int
4385xfs_btree_visit_blocks(
4386 struct xfs_btree_cur *cur,
4387 xfs_btree_visit_blocks_fn fn,
4388 unsigned int flags,
4389 void *data)
4390{
4391 union xfs_btree_ptr lptr;
4392 int level;
4393 struct xfs_btree_block *block = NULL;
4394 int error = 0;
4395
4396 cur->bc_ops->init_ptr_from_cur(cur, &lptr);
4397
4398 /* for each level */
4399 for (level = cur->bc_nlevels - 1; level >= 0; level--) {
4400 /* grab the left hand block */
4401 error = xfs_btree_lookup_get_block(cur, level, &lptr, &block);
4402 if (error)
4403 return error;
4404
4405 /* readahead the left most block for the next level down */
4406 if (level > 0) {
4407 union xfs_btree_ptr *ptr;
4408
4409 ptr = xfs_btree_ptr_addr(cur, 1, block);
4410 xfs_btree_readahead_ptr(cur, ptr, 1);
4411
4412 /* save for the next iteration of the loop */
4413 xfs_btree_copy_ptrs(cur, &lptr, ptr, 1);
4414
4415 if (!(flags & XFS_BTREE_VISIT_LEAVES))
4416 continue;
4417 } else if (!(flags & XFS_BTREE_VISIT_RECORDS)) {
4418 continue;
4419 }
4420
4421 /* for each buffer in the level */
4422 do {
4423 error = xfs_btree_visit_block(cur, level, fn, data);
4424 } while (!error);
4425
4426 if (error != -ENOENT)
4427 return error;
4428 }
4429
4430 return 0;
4431}
4432
4433/*
4434 * Change the owner of a btree.
4435 *
4436 * The mechanism we use here is ordered buffer logging. Because we don't know
4437 * how many buffers were are going to need to modify, we don't really want to
4438 * have to make transaction reservations for the worst case of every buffer in a
4439 * full size btree as that may be more space that we can fit in the log....
4440 *
4441 * We do the btree walk in the most optimal manner possible - we have sibling
4442 * pointers so we can just walk all the blocks on each level from left to right
4443 * in a single pass, and then move to the next level and do the same. We can
4444 * also do readahead on the sibling pointers to get IO moving more quickly,
4445 * though for slow disks this is unlikely to make much difference to performance
4446 * as the amount of CPU work we have to do before moving to the next block is
4447 * relatively small.
4448 *
4449 * For each btree block that we load, modify the owner appropriately, set the
4450 * buffer as an ordered buffer and log it appropriately. We need to ensure that
4451 * we mark the region we change dirty so that if the buffer is relogged in
4452 * a subsequent transaction the changes we make here as an ordered buffer are
4453 * correctly relogged in that transaction. If we are in recovery context, then
4454 * just queue the modified buffer as delayed write buffer so the transaction
4455 * recovery completion writes the changes to disk.
4456 */
4457struct xfs_btree_block_change_owner_info {
4458 uint64_t new_owner;
4459 struct list_head *buffer_list;
4460};
4461
4462static int
4463xfs_btree_block_change_owner(
4464 struct xfs_btree_cur *cur,
4465 int level,
4466 void *data)
4467{
4468 struct xfs_btree_block_change_owner_info *bbcoi = data;
4469 struct xfs_btree_block *block;
4470 struct xfs_buf *bp;
4471
4472 /* modify the owner */
4473 block = xfs_btree_get_block(cur, level, &bp);
4474 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
4475 if (block->bb_u.l.bb_owner == cpu_to_be64(bbcoi->new_owner))
4476 return 0;
4477 block->bb_u.l.bb_owner = cpu_to_be64(bbcoi->new_owner);
4478 } else {
4479 if (block->bb_u.s.bb_owner == cpu_to_be32(bbcoi->new_owner))
4480 return 0;
4481 block->bb_u.s.bb_owner = cpu_to_be32(bbcoi->new_owner);
4482 }
4483
4484 /*
4485 * If the block is a root block hosted in an inode, we might not have a
4486 * buffer pointer here and we shouldn't attempt to log the change as the
4487 * information is already held in the inode and discarded when the root
4488 * block is formatted into the on-disk inode fork. We still change it,
4489 * though, so everything is consistent in memory.
4490 */
4491 if (!bp) {
4492 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
4493 ASSERT(level == cur->bc_nlevels - 1);
4494 return 0;
4495 }
4496
4497 if (cur->bc_tp) {
4498 if (!xfs_trans_ordered_buf(cur->bc_tp, bp)) {
4499 xfs_btree_log_block(cur, bp, XFS_BB_OWNER);
4500 return -EAGAIN;
4501 }
4502 } else {
4503 xfs_buf_delwri_queue(bp, bbcoi->buffer_list);
4504 }
4505
4506 return 0;
4507}
4508
4509int
4510xfs_btree_change_owner(
4511 struct xfs_btree_cur *cur,
4512 uint64_t new_owner,
4513 struct list_head *buffer_list)
4514{
4515 struct xfs_btree_block_change_owner_info bbcoi;
4516
4517 bbcoi.new_owner = new_owner;
4518 bbcoi.buffer_list = buffer_list;
4519
4520 return xfs_btree_visit_blocks(cur, xfs_btree_block_change_owner,
4521 XFS_BTREE_VISIT_ALL, &bbcoi);
4522}
4523
4524/* Verify the v5 fields of a long-format btree block. */
4525xfs_failaddr_t
4526xfs_btree_lblock_v5hdr_verify(
4527 struct xfs_buf *bp,
4528 uint64_t owner)
4529{
4530 struct xfs_mount *mp = bp->b_mount;
4531 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
4532
4533 if (!xfs_has_crc(mp))
4534 return __this_address;
4535 if (!uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid))
4536 return __this_address;
4537 if (block->bb_u.l.bb_blkno != cpu_to_be64(xfs_buf_daddr(bp)))
4538 return __this_address;
4539 if (owner != XFS_RMAP_OWN_UNKNOWN &&
4540 be64_to_cpu(block->bb_u.l.bb_owner) != owner)
4541 return __this_address;
4542 return NULL;
4543}
4544
4545/* Verify a long-format btree block. */
4546xfs_failaddr_t
4547xfs_btree_lblock_verify(
4548 struct xfs_buf *bp,
4549 unsigned int max_recs)
4550{
4551 struct xfs_mount *mp = bp->b_mount;
4552 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
4553 xfs_fsblock_t fsb;
4554 xfs_failaddr_t fa;
4555
4556 /* numrecs verification */
4557 if (be16_to_cpu(block->bb_numrecs) > max_recs)
4558 return __this_address;
4559
4560 /* sibling pointer verification */
4561 fsb = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp));
4562 fa = xfs_btree_check_lblock_siblings(mp, NULL, -1, fsb,
4563 block->bb_u.l.bb_leftsib);
4564 if (!fa)
4565 fa = xfs_btree_check_lblock_siblings(mp, NULL, -1, fsb,
4566 block->bb_u.l.bb_rightsib);
4567 return fa;
4568}
4569
4570/**
4571 * xfs_btree_sblock_v5hdr_verify() -- verify the v5 fields of a short-format
4572 * btree block
4573 *
4574 * @bp: buffer containing the btree block
4575 */
4576xfs_failaddr_t
4577xfs_btree_sblock_v5hdr_verify(
4578 struct xfs_buf *bp)
4579{
4580 struct xfs_mount *mp = bp->b_mount;
4581 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
4582 struct xfs_perag *pag = bp->b_pag;
4583
4584 if (!xfs_has_crc(mp))
4585 return __this_address;
4586 if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid))
4587 return __this_address;
4588 if (block->bb_u.s.bb_blkno != cpu_to_be64(xfs_buf_daddr(bp)))
4589 return __this_address;
4590 if (pag && be32_to_cpu(block->bb_u.s.bb_owner) != pag->pag_agno)
4591 return __this_address;
4592 return NULL;
4593}
4594
4595/**
4596 * xfs_btree_sblock_verify() -- verify a short-format btree block
4597 *
4598 * @bp: buffer containing the btree block
4599 * @max_recs: maximum records allowed in this btree node
4600 */
4601xfs_failaddr_t
4602xfs_btree_sblock_verify(
4603 struct xfs_buf *bp,
4604 unsigned int max_recs)
4605{
4606 struct xfs_mount *mp = bp->b_mount;
4607 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
4608 xfs_agblock_t agbno;
4609 xfs_failaddr_t fa;
4610
4611 /* numrecs verification */
4612 if (be16_to_cpu(block->bb_numrecs) > max_recs)
4613 return __this_address;
4614
4615 /* sibling pointer verification */
4616 agbno = xfs_daddr_to_agbno(mp, xfs_buf_daddr(bp));
4617 fa = xfs_btree_check_sblock_siblings(bp->b_pag, NULL, -1, agbno,
4618 block->bb_u.s.bb_leftsib);
4619 if (!fa)
4620 fa = xfs_btree_check_sblock_siblings(bp->b_pag, NULL, -1, agbno,
4621 block->bb_u.s.bb_rightsib);
4622 return fa;
4623}
4624
4625/*
4626 * For the given limits on leaf and keyptr records per block, calculate the
4627 * height of the tree needed to index the number of leaf records.
4628 */
4629unsigned int
4630xfs_btree_compute_maxlevels(
4631 const unsigned int *limits,
4632 unsigned long long records)
4633{
4634 unsigned long long level_blocks = howmany_64(records, limits[0]);
4635 unsigned int height = 1;
4636
4637 while (level_blocks > 1) {
4638 level_blocks = howmany_64(level_blocks, limits[1]);
4639 height++;
4640 }
4641
4642 return height;
4643}
4644
4645/*
4646 * For the given limits on leaf and keyptr records per block, calculate the
4647 * number of blocks needed to index the given number of leaf records.
4648 */
4649unsigned long long
4650xfs_btree_calc_size(
4651 const unsigned int *limits,
4652 unsigned long long records)
4653{
4654 unsigned long long level_blocks = howmany_64(records, limits[0]);
4655 unsigned long long blocks = level_blocks;
4656
4657 while (level_blocks > 1) {
4658 level_blocks = howmany_64(level_blocks, limits[1]);
4659 blocks += level_blocks;
4660 }
4661
4662 return blocks;
4663}
4664
4665/*
4666 * Given a number of available blocks for the btree to consume with records and
4667 * pointers, calculate the height of the tree needed to index all the records
4668 * that space can hold based on the number of pointers each interior node
4669 * holds.
4670 *
4671 * We start by assuming a single level tree consumes a single block, then track
4672 * the number of blocks each node level consumes until we no longer have space
4673 * to store the next node level. At this point, we are indexing all the leaf
4674 * blocks in the space, and there's no more free space to split the tree any
4675 * further. That's our maximum btree height.
4676 */
4677unsigned int
4678xfs_btree_space_to_height(
4679 const unsigned int *limits,
4680 unsigned long long leaf_blocks)
4681{
4682 /*
4683 * The root btree block can have fewer than minrecs pointers in it
4684 * because the tree might not be big enough to require that amount of
4685 * fanout. Hence it has a minimum size of 2 pointers, not limits[1].
4686 */
4687 unsigned long long node_blocks = 2;
4688 unsigned long long blocks_left = leaf_blocks - 1;
4689 unsigned int height = 1;
4690
4691 if (leaf_blocks < 1)
4692 return 0;
4693
4694 while (node_blocks < blocks_left) {
4695 blocks_left -= node_blocks;
4696 node_blocks *= limits[1];
4697 height++;
4698 }
4699
4700 return height;
4701}
4702
4703/*
4704 * Query a regular btree for all records overlapping a given interval.
4705 * Start with a LE lookup of the key of low_rec and return all records
4706 * until we find a record with a key greater than the key of high_rec.
4707 */
4708STATIC int
4709xfs_btree_simple_query_range(
4710 struct xfs_btree_cur *cur,
4711 const union xfs_btree_key *low_key,
4712 const union xfs_btree_key *high_key,
4713 xfs_btree_query_range_fn fn,
4714 void *priv)
4715{
4716 union xfs_btree_rec *recp;
4717 union xfs_btree_key rec_key;
4718 int stat;
4719 bool firstrec = true;
4720 int error;
4721
4722 ASSERT(cur->bc_ops->init_high_key_from_rec);
4723 ASSERT(cur->bc_ops->diff_two_keys);
4724
4725 /*
4726 * Find the leftmost record. The btree cursor must be set
4727 * to the low record used to generate low_key.
4728 */
4729 stat = 0;
4730 error = xfs_btree_lookup(cur, XFS_LOOKUP_LE, &stat);
4731 if (error)
4732 goto out;
4733
4734 /* Nothing? See if there's anything to the right. */
4735 if (!stat) {
4736 error = xfs_btree_increment(cur, 0, &stat);
4737 if (error)
4738 goto out;
4739 }
4740
4741 while (stat) {
4742 /* Find the record. */
4743 error = xfs_btree_get_rec(cur, &recp, &stat);
4744 if (error || !stat)
4745 break;
4746
4747 /* Skip if low_key > high_key(rec). */
4748 if (firstrec) {
4749 cur->bc_ops->init_high_key_from_rec(&rec_key, recp);
4750 firstrec = false;
4751 if (xfs_btree_keycmp_gt(cur, low_key, &rec_key))
4752 goto advloop;
4753 }
4754
4755 /* Stop if low_key(rec) > high_key. */
4756 cur->bc_ops->init_key_from_rec(&rec_key, recp);
4757 if (xfs_btree_keycmp_gt(cur, &rec_key, high_key))
4758 break;
4759
4760 /* Callback */
4761 error = fn(cur, recp, priv);
4762 if (error)
4763 break;
4764
4765advloop:
4766 /* Move on to the next record. */
4767 error = xfs_btree_increment(cur, 0, &stat);
4768 if (error)
4769 break;
4770 }
4771
4772out:
4773 return error;
4774}
4775
4776/*
4777 * Query an overlapped interval btree for all records overlapping a given
4778 * interval. This function roughly follows the algorithm given in
4779 * "Interval Trees" of _Introduction to Algorithms_, which is section
4780 * 14.3 in the 2nd and 3rd editions.
4781 *
4782 * First, generate keys for the low and high records passed in.
4783 *
4784 * For any leaf node, generate the high and low keys for the record.
4785 * If the record keys overlap with the query low/high keys, pass the
4786 * record to the function iterator.
4787 *
4788 * For any internal node, compare the low and high keys of each
4789 * pointer against the query low/high keys. If there's an overlap,
4790 * follow the pointer.
4791 *
4792 * As an optimization, we stop scanning a block when we find a low key
4793 * that is greater than the query's high key.
4794 */
4795STATIC int
4796xfs_btree_overlapped_query_range(
4797 struct xfs_btree_cur *cur,
4798 const union xfs_btree_key *low_key,
4799 const union xfs_btree_key *high_key,
4800 xfs_btree_query_range_fn fn,
4801 void *priv)
4802{
4803 union xfs_btree_ptr ptr;
4804 union xfs_btree_ptr *pp;
4805 union xfs_btree_key rec_key;
4806 union xfs_btree_key rec_hkey;
4807 union xfs_btree_key *lkp;
4808 union xfs_btree_key *hkp;
4809 union xfs_btree_rec *recp;
4810 struct xfs_btree_block *block;
4811 int level;
4812 struct xfs_buf *bp;
4813 int i;
4814 int error;
4815
4816 /* Load the root of the btree. */
4817 level = cur->bc_nlevels - 1;
4818 cur->bc_ops->init_ptr_from_cur(cur, &ptr);
4819 error = xfs_btree_lookup_get_block(cur, level, &ptr, &block);
4820 if (error)
4821 return error;
4822 xfs_btree_get_block(cur, level, &bp);
4823 trace_xfs_btree_overlapped_query_range(cur, level, bp);
4824#ifdef DEBUG
4825 error = xfs_btree_check_block(cur, block, level, bp);
4826 if (error)
4827 goto out;
4828#endif
4829 cur->bc_levels[level].ptr = 1;
4830
4831 while (level < cur->bc_nlevels) {
4832 block = xfs_btree_get_block(cur, level, &bp);
4833
4834 /* End of node, pop back towards the root. */
4835 if (cur->bc_levels[level].ptr >
4836 be16_to_cpu(block->bb_numrecs)) {
4837pop_up:
4838 if (level < cur->bc_nlevels - 1)
4839 cur->bc_levels[level + 1].ptr++;
4840 level++;
4841 continue;
4842 }
4843
4844 if (level == 0) {
4845 /* Handle a leaf node. */
4846 recp = xfs_btree_rec_addr(cur, cur->bc_levels[0].ptr,
4847 block);
4848
4849 cur->bc_ops->init_high_key_from_rec(&rec_hkey, recp);
4850 cur->bc_ops->init_key_from_rec(&rec_key, recp);
4851
4852 /*
4853 * If (query's high key < record's low key), then there
4854 * are no more interesting records in this block. Pop
4855 * up to the leaf level to find more record blocks.
4856 *
4857 * If (record's high key >= query's low key) and
4858 * (query's high key >= record's low key), then
4859 * this record overlaps the query range; callback.
4860 */
4861 if (xfs_btree_keycmp_lt(cur, high_key, &rec_key))
4862 goto pop_up;
4863 if (xfs_btree_keycmp_ge(cur, &rec_hkey, low_key)) {
4864 error = fn(cur, recp, priv);
4865 if (error)
4866 break;
4867 }
4868 cur->bc_levels[level].ptr++;
4869 continue;
4870 }
4871
4872 /* Handle an internal node. */
4873 lkp = xfs_btree_key_addr(cur, cur->bc_levels[level].ptr, block);
4874 hkp = xfs_btree_high_key_addr(cur, cur->bc_levels[level].ptr,
4875 block);
4876 pp = xfs_btree_ptr_addr(cur, cur->bc_levels[level].ptr, block);
4877
4878 /*
4879 * If (query's high key < pointer's low key), then there are no
4880 * more interesting keys in this block. Pop up one leaf level
4881 * to continue looking for records.
4882 *
4883 * If (pointer's high key >= query's low key) and
4884 * (query's high key >= pointer's low key), then
4885 * this record overlaps the query range; follow pointer.
4886 */
4887 if (xfs_btree_keycmp_lt(cur, high_key, lkp))
4888 goto pop_up;
4889 if (xfs_btree_keycmp_ge(cur, hkp, low_key)) {
4890 level--;
4891 error = xfs_btree_lookup_get_block(cur, level, pp,
4892 &block);
4893 if (error)
4894 goto out;
4895 xfs_btree_get_block(cur, level, &bp);
4896 trace_xfs_btree_overlapped_query_range(cur, level, bp);
4897#ifdef DEBUG
4898 error = xfs_btree_check_block(cur, block, level, bp);
4899 if (error)
4900 goto out;
4901#endif
4902 cur->bc_levels[level].ptr = 1;
4903 continue;
4904 }
4905 cur->bc_levels[level].ptr++;
4906 }
4907
4908out:
4909 /*
4910 * If we don't end this function with the cursor pointing at a record
4911 * block, a subsequent non-error cursor deletion will not release
4912 * node-level buffers, causing a buffer leak. This is quite possible
4913 * with a zero-results range query, so release the buffers if we
4914 * failed to return any results.
4915 */
4916 if (cur->bc_levels[0].bp == NULL) {
4917 for (i = 0; i < cur->bc_nlevels; i++) {
4918 if (cur->bc_levels[i].bp) {
4919 xfs_trans_brelse(cur->bc_tp,
4920 cur->bc_levels[i].bp);
4921 cur->bc_levels[i].bp = NULL;
4922 cur->bc_levels[i].ptr = 0;
4923 cur->bc_levels[i].ra = 0;
4924 }
4925 }
4926 }
4927
4928 return error;
4929}
4930
4931static inline void
4932xfs_btree_key_from_irec(
4933 struct xfs_btree_cur *cur,
4934 union xfs_btree_key *key,
4935 const union xfs_btree_irec *irec)
4936{
4937 union xfs_btree_rec rec;
4938
4939 cur->bc_rec = *irec;
4940 cur->bc_ops->init_rec_from_cur(cur, &rec);
4941 cur->bc_ops->init_key_from_rec(key, &rec);
4942}
4943
4944/*
4945 * Query a btree for all records overlapping a given interval of keys. The
4946 * supplied function will be called with each record found; return one of the
4947 * XFS_BTREE_QUERY_RANGE_{CONTINUE,ABORT} values or the usual negative error
4948 * code. This function returns -ECANCELED, zero, or a negative error code.
4949 */
4950int
4951xfs_btree_query_range(
4952 struct xfs_btree_cur *cur,
4953 const union xfs_btree_irec *low_rec,
4954 const union xfs_btree_irec *high_rec,
4955 xfs_btree_query_range_fn fn,
4956 void *priv)
4957{
4958 union xfs_btree_key low_key;
4959 union xfs_btree_key high_key;
4960
4961 /* Find the keys of both ends of the interval. */
4962 xfs_btree_key_from_irec(cur, &high_key, high_rec);
4963 xfs_btree_key_from_irec(cur, &low_key, low_rec);
4964
4965 /* Enforce low key <= high key. */
4966 if (!xfs_btree_keycmp_le(cur, &low_key, &high_key))
4967 return -EINVAL;
4968
4969 if (!(cur->bc_flags & XFS_BTREE_OVERLAPPING))
4970 return xfs_btree_simple_query_range(cur, &low_key,
4971 &high_key, fn, priv);
4972 return xfs_btree_overlapped_query_range(cur, &low_key, &high_key,
4973 fn, priv);
4974}
4975
4976/* Query a btree for all records. */
4977int
4978xfs_btree_query_all(
4979 struct xfs_btree_cur *cur,
4980 xfs_btree_query_range_fn fn,
4981 void *priv)
4982{
4983 union xfs_btree_key low_key;
4984 union xfs_btree_key high_key;
4985
4986 memset(&cur->bc_rec, 0, sizeof(cur->bc_rec));
4987 memset(&low_key, 0, sizeof(low_key));
4988 memset(&high_key, 0xFF, sizeof(high_key));
4989
4990 return xfs_btree_simple_query_range(cur, &low_key, &high_key, fn, priv);
4991}
4992
4993static int
4994xfs_btree_count_blocks_helper(
4995 struct xfs_btree_cur *cur,
4996 int level,
4997 void *data)
4998{
4999 xfs_extlen_t *blocks = data;
5000 (*blocks)++;
5001
5002 return 0;
5003}
5004
5005/* Count the blocks in a btree and return the result in *blocks. */
5006int
5007xfs_btree_count_blocks(
5008 struct xfs_btree_cur *cur,
5009 xfs_extlen_t *blocks)
5010{
5011 *blocks = 0;
5012 return xfs_btree_visit_blocks(cur, xfs_btree_count_blocks_helper,
5013 XFS_BTREE_VISIT_ALL, blocks);
5014}
5015
5016/* Compare two btree pointers. */
5017int64_t
5018xfs_btree_diff_two_ptrs(
5019 struct xfs_btree_cur *cur,
5020 const union xfs_btree_ptr *a,
5021 const union xfs_btree_ptr *b)
5022{
5023 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
5024 return (int64_t)be64_to_cpu(a->l) - be64_to_cpu(b->l);
5025 return (int64_t)be32_to_cpu(a->s) - be32_to_cpu(b->s);
5026}
5027
5028struct xfs_btree_has_records {
5029 /* Keys for the start and end of the range we want to know about. */
5030 union xfs_btree_key start_key;
5031 union xfs_btree_key end_key;
5032
5033 /* Mask for key comparisons, if desired. */
5034 const union xfs_btree_key *key_mask;
5035
5036 /* Highest record key we've seen so far. */
5037 union xfs_btree_key high_key;
5038
5039 enum xbtree_recpacking outcome;
5040};
5041
5042STATIC int
5043xfs_btree_has_records_helper(
5044 struct xfs_btree_cur *cur,
5045 const union xfs_btree_rec *rec,
5046 void *priv)
5047{
5048 union xfs_btree_key rec_key;
5049 union xfs_btree_key rec_high_key;
5050 struct xfs_btree_has_records *info = priv;
5051 enum xbtree_key_contig key_contig;
5052
5053 cur->bc_ops->init_key_from_rec(&rec_key, rec);
5054
5055 if (info->outcome == XBTREE_RECPACKING_EMPTY) {
5056 info->outcome = XBTREE_RECPACKING_SPARSE;
5057
5058 /*
5059 * If the first record we find does not overlap the start key,
5060 * then there is a hole at the start of the search range.
5061 * Classify this as sparse and stop immediately.
5062 */
5063 if (xfs_btree_masked_keycmp_lt(cur, &info->start_key, &rec_key,
5064 info->key_mask))
5065 return -ECANCELED;
5066 } else {
5067 /*
5068 * If a subsequent record does not overlap with the any record
5069 * we've seen so far, there is a hole in the middle of the
5070 * search range. Classify this as sparse and stop.
5071 * If the keys overlap and this btree does not allow overlap,
5072 * signal corruption.
5073 */
5074 key_contig = cur->bc_ops->keys_contiguous(cur, &info->high_key,
5075 &rec_key, info->key_mask);
5076 if (key_contig == XBTREE_KEY_OVERLAP &&
5077 !(cur->bc_flags & XFS_BTREE_OVERLAPPING))
5078 return -EFSCORRUPTED;
5079 if (key_contig == XBTREE_KEY_GAP)
5080 return -ECANCELED;
5081 }
5082
5083 /*
5084 * If high_key(rec) is larger than any other high key we've seen,
5085 * remember it for later.
5086 */
5087 cur->bc_ops->init_high_key_from_rec(&rec_high_key, rec);
5088 if (xfs_btree_masked_keycmp_gt(cur, &rec_high_key, &info->high_key,
5089 info->key_mask))
5090 info->high_key = rec_high_key; /* struct copy */
5091
5092 return 0;
5093}
5094
5095/*
5096 * Scan part of the keyspace of a btree and tell us if that keyspace does not
5097 * map to any records; is fully mapped to records; or is partially mapped to
5098 * records. This is the btree record equivalent to determining if a file is
5099 * sparse.
5100 *
5101 * For most btree types, the record scan should use all available btree key
5102 * fields to compare the keys encountered. These callers should pass NULL for
5103 * @mask. However, some callers (e.g. scanning physical space in the rmapbt)
5104 * want to ignore some part of the btree record keyspace when performing the
5105 * comparison. These callers should pass in a union xfs_btree_key object with
5106 * the fields that *should* be a part of the comparison set to any nonzero
5107 * value, and the rest zeroed.
5108 */
5109int
5110xfs_btree_has_records(
5111 struct xfs_btree_cur *cur,
5112 const union xfs_btree_irec *low,
5113 const union xfs_btree_irec *high,
5114 const union xfs_btree_key *mask,
5115 enum xbtree_recpacking *outcome)
5116{
5117 struct xfs_btree_has_records info = {
5118 .outcome = XBTREE_RECPACKING_EMPTY,
5119 .key_mask = mask,
5120 };
5121 int error;
5122
5123 /* Not all btrees support this operation. */
5124 if (!cur->bc_ops->keys_contiguous) {
5125 ASSERT(0);
5126 return -EOPNOTSUPP;
5127 }
5128
5129 xfs_btree_key_from_irec(cur, &info.start_key, low);
5130 xfs_btree_key_from_irec(cur, &info.end_key, high);
5131
5132 error = xfs_btree_query_range(cur, low, high,
5133 xfs_btree_has_records_helper, &info);
5134 if (error == -ECANCELED)
5135 goto out;
5136 if (error)
5137 return error;
5138
5139 if (info.outcome == XBTREE_RECPACKING_EMPTY)
5140 goto out;
5141
5142 /*
5143 * If the largest high_key(rec) we saw during the walk is greater than
5144 * the end of the search range, classify this as full. Otherwise,
5145 * there is a hole at the end of the search range.
5146 */
5147 if (xfs_btree_masked_keycmp_ge(cur, &info.high_key, &info.end_key,
5148 mask))
5149 info.outcome = XBTREE_RECPACKING_FULL;
5150
5151out:
5152 *outcome = info.outcome;
5153 return 0;
5154}
5155
5156/* Are there more records in this btree? */
5157bool
5158xfs_btree_has_more_records(
5159 struct xfs_btree_cur *cur)
5160{
5161 struct xfs_btree_block *block;
5162 struct xfs_buf *bp;
5163
5164 block = xfs_btree_get_block(cur, 0, &bp);
5165
5166 /* There are still records in this block. */
5167 if (cur->bc_levels[0].ptr < xfs_btree_get_numrecs(block))
5168 return true;
5169
5170 /* There are more record blocks. */
5171 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
5172 return block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK);
5173 else
5174 return block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK);
5175}
5176
5177/* Set up all the btree cursor caches. */
5178int __init
5179xfs_btree_init_cur_caches(void)
5180{
5181 int error;
5182
5183 error = xfs_allocbt_init_cur_cache();
5184 if (error)
5185 return error;
5186 error = xfs_inobt_init_cur_cache();
5187 if (error)
5188 goto err;
5189 error = xfs_bmbt_init_cur_cache();
5190 if (error)
5191 goto err;
5192 error = xfs_rmapbt_init_cur_cache();
5193 if (error)
5194 goto err;
5195 error = xfs_refcountbt_init_cur_cache();
5196 if (error)
5197 goto err;
5198
5199 return 0;
5200err:
5201 xfs_btree_destroy_cur_caches();
5202 return error;
5203}
5204
5205/* Destroy all the btree cursor caches, if they've been allocated. */
5206void
5207xfs_btree_destroy_cur_caches(void)
5208{
5209 xfs_allocbt_destroy_cur_cache();
5210 xfs_inobt_destroy_cur_cache();
5211 xfs_bmbt_destroy_cur_cache();
5212 xfs_rmapbt_destroy_cur_cache();
5213 xfs_refcountbt_destroy_cur_cache();
5214}
5215
5216/* Move the btree cursor before the first record. */
5217int
5218xfs_btree_goto_left_edge(
5219 struct xfs_btree_cur *cur)
5220{
5221 int stat = 0;
5222 int error;
5223
5224 memset(&cur->bc_rec, 0, sizeof(cur->bc_rec));
5225 error = xfs_btree_lookup(cur, XFS_LOOKUP_LE, &stat);
5226 if (error)
5227 return error;
5228 if (!stat)
5229 return 0;
5230
5231 error = xfs_btree_decrement(cur, 0, &stat);
5232 if (error)
5233 return error;
5234 if (stat != 0) {
5235 ASSERT(0);
5236 return -EFSCORRUPTED;
5237 }
5238
5239 return 0;
5240}
1/*
2 * Copyright (c) 2000-2002,2005 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#include "xfs.h"
19#include "xfs_fs.h"
20#include "xfs_shared.h"
21#include "xfs_format.h"
22#include "xfs_log_format.h"
23#include "xfs_trans_resv.h"
24#include "xfs_bit.h"
25#include "xfs_mount.h"
26#include "xfs_defer.h"
27#include "xfs_inode.h"
28#include "xfs_trans.h"
29#include "xfs_inode_item.h"
30#include "xfs_buf_item.h"
31#include "xfs_btree.h"
32#include "xfs_error.h"
33#include "xfs_trace.h"
34#include "xfs_cksum.h"
35#include "xfs_alloc.h"
36#include "xfs_log.h"
37
38/*
39 * Cursor allocation zone.
40 */
41kmem_zone_t *xfs_btree_cur_zone;
42
43/*
44 * Btree magic numbers.
45 */
46static const __uint32_t xfs_magics[2][XFS_BTNUM_MAX] = {
47 { XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, 0, XFS_BMAP_MAGIC, XFS_IBT_MAGIC,
48 XFS_FIBT_MAGIC, 0 },
49 { XFS_ABTB_CRC_MAGIC, XFS_ABTC_CRC_MAGIC, XFS_RMAP_CRC_MAGIC,
50 XFS_BMAP_CRC_MAGIC, XFS_IBT_CRC_MAGIC, XFS_FIBT_CRC_MAGIC,
51 XFS_REFC_CRC_MAGIC }
52};
53#define xfs_btree_magic(cur) \
54 xfs_magics[!!((cur)->bc_flags & XFS_BTREE_CRC_BLOCKS)][cur->bc_btnum]
55
56STATIC int /* error (0 or EFSCORRUPTED) */
57xfs_btree_check_lblock(
58 struct xfs_btree_cur *cur, /* btree cursor */
59 struct xfs_btree_block *block, /* btree long form block pointer */
60 int level, /* level of the btree block */
61 struct xfs_buf *bp) /* buffer for block, if any */
62{
63 int lblock_ok = 1; /* block passes checks */
64 struct xfs_mount *mp; /* file system mount point */
65
66 mp = cur->bc_mp;
67
68 if (xfs_sb_version_hascrc(&mp->m_sb)) {
69 lblock_ok = lblock_ok &&
70 uuid_equal(&block->bb_u.l.bb_uuid,
71 &mp->m_sb.sb_meta_uuid) &&
72 block->bb_u.l.bb_blkno == cpu_to_be64(
73 bp ? bp->b_bn : XFS_BUF_DADDR_NULL);
74 }
75
76 lblock_ok = lblock_ok &&
77 be32_to_cpu(block->bb_magic) == xfs_btree_magic(cur) &&
78 be16_to_cpu(block->bb_level) == level &&
79 be16_to_cpu(block->bb_numrecs) <=
80 cur->bc_ops->get_maxrecs(cur, level) &&
81 block->bb_u.l.bb_leftsib &&
82 (block->bb_u.l.bb_leftsib == cpu_to_be64(NULLFSBLOCK) ||
83 XFS_FSB_SANITY_CHECK(mp,
84 be64_to_cpu(block->bb_u.l.bb_leftsib))) &&
85 block->bb_u.l.bb_rightsib &&
86 (block->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK) ||
87 XFS_FSB_SANITY_CHECK(mp,
88 be64_to_cpu(block->bb_u.l.bb_rightsib)));
89
90 if (unlikely(XFS_TEST_ERROR(!lblock_ok, mp,
91 XFS_ERRTAG_BTREE_CHECK_LBLOCK,
92 XFS_RANDOM_BTREE_CHECK_LBLOCK))) {
93 if (bp)
94 trace_xfs_btree_corrupt(bp, _RET_IP_);
95 XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
96 return -EFSCORRUPTED;
97 }
98 return 0;
99}
100
101STATIC int /* error (0 or EFSCORRUPTED) */
102xfs_btree_check_sblock(
103 struct xfs_btree_cur *cur, /* btree cursor */
104 struct xfs_btree_block *block, /* btree short form block pointer */
105 int level, /* level of the btree block */
106 struct xfs_buf *bp) /* buffer containing block */
107{
108 struct xfs_mount *mp; /* file system mount point */
109 struct xfs_buf *agbp; /* buffer for ag. freespace struct */
110 struct xfs_agf *agf; /* ag. freespace structure */
111 xfs_agblock_t agflen; /* native ag. freespace length */
112 int sblock_ok = 1; /* block passes checks */
113
114 mp = cur->bc_mp;
115 agbp = cur->bc_private.a.agbp;
116 agf = XFS_BUF_TO_AGF(agbp);
117 agflen = be32_to_cpu(agf->agf_length);
118
119 if (xfs_sb_version_hascrc(&mp->m_sb)) {
120 sblock_ok = sblock_ok &&
121 uuid_equal(&block->bb_u.s.bb_uuid,
122 &mp->m_sb.sb_meta_uuid) &&
123 block->bb_u.s.bb_blkno == cpu_to_be64(
124 bp ? bp->b_bn : XFS_BUF_DADDR_NULL);
125 }
126
127 sblock_ok = sblock_ok &&
128 be32_to_cpu(block->bb_magic) == xfs_btree_magic(cur) &&
129 be16_to_cpu(block->bb_level) == level &&
130 be16_to_cpu(block->bb_numrecs) <=
131 cur->bc_ops->get_maxrecs(cur, level) &&
132 (block->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK) ||
133 be32_to_cpu(block->bb_u.s.bb_leftsib) < agflen) &&
134 block->bb_u.s.bb_leftsib &&
135 (block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK) ||
136 be32_to_cpu(block->bb_u.s.bb_rightsib) < agflen) &&
137 block->bb_u.s.bb_rightsib;
138
139 if (unlikely(XFS_TEST_ERROR(!sblock_ok, mp,
140 XFS_ERRTAG_BTREE_CHECK_SBLOCK,
141 XFS_RANDOM_BTREE_CHECK_SBLOCK))) {
142 if (bp)
143 trace_xfs_btree_corrupt(bp, _RET_IP_);
144 XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
145 return -EFSCORRUPTED;
146 }
147 return 0;
148}
149
150/*
151 * Debug routine: check that block header is ok.
152 */
153int
154xfs_btree_check_block(
155 struct xfs_btree_cur *cur, /* btree cursor */
156 struct xfs_btree_block *block, /* generic btree block pointer */
157 int level, /* level of the btree block */
158 struct xfs_buf *bp) /* buffer containing block, if any */
159{
160 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
161 return xfs_btree_check_lblock(cur, block, level, bp);
162 else
163 return xfs_btree_check_sblock(cur, block, level, bp);
164}
165
166/*
167 * Check that (long) pointer is ok.
168 */
169int /* error (0 or EFSCORRUPTED) */
170xfs_btree_check_lptr(
171 struct xfs_btree_cur *cur, /* btree cursor */
172 xfs_fsblock_t bno, /* btree block disk address */
173 int level) /* btree block level */
174{
175 XFS_WANT_CORRUPTED_RETURN(cur->bc_mp,
176 level > 0 &&
177 bno != NULLFSBLOCK &&
178 XFS_FSB_SANITY_CHECK(cur->bc_mp, bno));
179 return 0;
180}
181
182#ifdef DEBUG
183/*
184 * Check that (short) pointer is ok.
185 */
186STATIC int /* error (0 or EFSCORRUPTED) */
187xfs_btree_check_sptr(
188 struct xfs_btree_cur *cur, /* btree cursor */
189 xfs_agblock_t bno, /* btree block disk address */
190 int level) /* btree block level */
191{
192 xfs_agblock_t agblocks = cur->bc_mp->m_sb.sb_agblocks;
193
194 XFS_WANT_CORRUPTED_RETURN(cur->bc_mp,
195 level > 0 &&
196 bno != NULLAGBLOCK &&
197 bno != 0 &&
198 bno < agblocks);
199 return 0;
200}
201
202/*
203 * Check that block ptr is ok.
204 */
205STATIC int /* error (0 or EFSCORRUPTED) */
206xfs_btree_check_ptr(
207 struct xfs_btree_cur *cur, /* btree cursor */
208 union xfs_btree_ptr *ptr, /* btree block disk address */
209 int index, /* offset from ptr to check */
210 int level) /* btree block level */
211{
212 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
213 return xfs_btree_check_lptr(cur,
214 be64_to_cpu((&ptr->l)[index]), level);
215 } else {
216 return xfs_btree_check_sptr(cur,
217 be32_to_cpu((&ptr->s)[index]), level);
218 }
219}
220#endif
221
222/*
223 * Calculate CRC on the whole btree block and stuff it into the
224 * long-form btree header.
225 *
226 * Prior to calculting the CRC, pull the LSN out of the buffer log item and put
227 * it into the buffer so recovery knows what the last modification was that made
228 * it to disk.
229 */
230void
231xfs_btree_lblock_calc_crc(
232 struct xfs_buf *bp)
233{
234 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
235 struct xfs_buf_log_item *bip = bp->b_fspriv;
236
237 if (!xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb))
238 return;
239 if (bip)
240 block->bb_u.l.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
241 xfs_buf_update_cksum(bp, XFS_BTREE_LBLOCK_CRC_OFF);
242}
243
244bool
245xfs_btree_lblock_verify_crc(
246 struct xfs_buf *bp)
247{
248 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
249 struct xfs_mount *mp = bp->b_target->bt_mount;
250
251 if (xfs_sb_version_hascrc(&mp->m_sb)) {
252 if (!xfs_log_check_lsn(mp, be64_to_cpu(block->bb_u.l.bb_lsn)))
253 return false;
254 return xfs_buf_verify_cksum(bp, XFS_BTREE_LBLOCK_CRC_OFF);
255 }
256
257 return true;
258}
259
260/*
261 * Calculate CRC on the whole btree block and stuff it into the
262 * short-form btree header.
263 *
264 * Prior to calculting the CRC, pull the LSN out of the buffer log item and put
265 * it into the buffer so recovery knows what the last modification was that made
266 * it to disk.
267 */
268void
269xfs_btree_sblock_calc_crc(
270 struct xfs_buf *bp)
271{
272 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
273 struct xfs_buf_log_item *bip = bp->b_fspriv;
274
275 if (!xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb))
276 return;
277 if (bip)
278 block->bb_u.s.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
279 xfs_buf_update_cksum(bp, XFS_BTREE_SBLOCK_CRC_OFF);
280}
281
282bool
283xfs_btree_sblock_verify_crc(
284 struct xfs_buf *bp)
285{
286 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
287 struct xfs_mount *mp = bp->b_target->bt_mount;
288
289 if (xfs_sb_version_hascrc(&mp->m_sb)) {
290 if (!xfs_log_check_lsn(mp, be64_to_cpu(block->bb_u.s.bb_lsn)))
291 return false;
292 return xfs_buf_verify_cksum(bp, XFS_BTREE_SBLOCK_CRC_OFF);
293 }
294
295 return true;
296}
297
298static int
299xfs_btree_free_block(
300 struct xfs_btree_cur *cur,
301 struct xfs_buf *bp)
302{
303 int error;
304
305 error = cur->bc_ops->free_block(cur, bp);
306 if (!error) {
307 xfs_trans_binval(cur->bc_tp, bp);
308 XFS_BTREE_STATS_INC(cur, free);
309 }
310 return error;
311}
312
313/*
314 * Delete the btree cursor.
315 */
316void
317xfs_btree_del_cursor(
318 xfs_btree_cur_t *cur, /* btree cursor */
319 int error) /* del because of error */
320{
321 int i; /* btree level */
322
323 /*
324 * Clear the buffer pointers, and release the buffers.
325 * If we're doing this in the face of an error, we
326 * need to make sure to inspect all of the entries
327 * in the bc_bufs array for buffers to be unlocked.
328 * This is because some of the btree code works from
329 * level n down to 0, and if we get an error along
330 * the way we won't have initialized all the entries
331 * down to 0.
332 */
333 for (i = 0; i < cur->bc_nlevels; i++) {
334 if (cur->bc_bufs[i])
335 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[i]);
336 else if (!error)
337 break;
338 }
339 /*
340 * Can't free a bmap cursor without having dealt with the
341 * allocated indirect blocks' accounting.
342 */
343 ASSERT(cur->bc_btnum != XFS_BTNUM_BMAP ||
344 cur->bc_private.b.allocated == 0);
345 /*
346 * Free the cursor.
347 */
348 kmem_zone_free(xfs_btree_cur_zone, cur);
349}
350
351/*
352 * Duplicate the btree cursor.
353 * Allocate a new one, copy the record, re-get the buffers.
354 */
355int /* error */
356xfs_btree_dup_cursor(
357 xfs_btree_cur_t *cur, /* input cursor */
358 xfs_btree_cur_t **ncur) /* output cursor */
359{
360 xfs_buf_t *bp; /* btree block's buffer pointer */
361 int error; /* error return value */
362 int i; /* level number of btree block */
363 xfs_mount_t *mp; /* mount structure for filesystem */
364 xfs_btree_cur_t *new; /* new cursor value */
365 xfs_trans_t *tp; /* transaction pointer, can be NULL */
366
367 tp = cur->bc_tp;
368 mp = cur->bc_mp;
369
370 /*
371 * Allocate a new cursor like the old one.
372 */
373 new = cur->bc_ops->dup_cursor(cur);
374
375 /*
376 * Copy the record currently in the cursor.
377 */
378 new->bc_rec = cur->bc_rec;
379
380 /*
381 * For each level current, re-get the buffer and copy the ptr value.
382 */
383 for (i = 0; i < new->bc_nlevels; i++) {
384 new->bc_ptrs[i] = cur->bc_ptrs[i];
385 new->bc_ra[i] = cur->bc_ra[i];
386 bp = cur->bc_bufs[i];
387 if (bp) {
388 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
389 XFS_BUF_ADDR(bp), mp->m_bsize,
390 0, &bp,
391 cur->bc_ops->buf_ops);
392 if (error) {
393 xfs_btree_del_cursor(new, error);
394 *ncur = NULL;
395 return error;
396 }
397 }
398 new->bc_bufs[i] = bp;
399 }
400 *ncur = new;
401 return 0;
402}
403
404/*
405 * XFS btree block layout and addressing:
406 *
407 * There are two types of blocks in the btree: leaf and non-leaf blocks.
408 *
409 * The leaf record start with a header then followed by records containing
410 * the values. A non-leaf block also starts with the same header, and
411 * then first contains lookup keys followed by an equal number of pointers
412 * to the btree blocks at the previous level.
413 *
414 * +--------+-------+-------+-------+-------+-------+-------+
415 * Leaf: | header | rec 1 | rec 2 | rec 3 | rec 4 | rec 5 | rec N |
416 * +--------+-------+-------+-------+-------+-------+-------+
417 *
418 * +--------+-------+-------+-------+-------+-------+-------+
419 * Non-Leaf: | header | key 1 | key 2 | key N | ptr 1 | ptr 2 | ptr N |
420 * +--------+-------+-------+-------+-------+-------+-------+
421 *
422 * The header is called struct xfs_btree_block for reasons better left unknown
423 * and comes in different versions for short (32bit) and long (64bit) block
424 * pointers. The record and key structures are defined by the btree instances
425 * and opaque to the btree core. The block pointers are simple disk endian
426 * integers, available in a short (32bit) and long (64bit) variant.
427 *
428 * The helpers below calculate the offset of a given record, key or pointer
429 * into a btree block (xfs_btree_*_offset) or return a pointer to the given
430 * record, key or pointer (xfs_btree_*_addr). Note that all addressing
431 * inside the btree block is done using indices starting at one, not zero!
432 *
433 * If XFS_BTREE_OVERLAPPING is set, then this btree supports keys containing
434 * overlapping intervals. In such a tree, records are still sorted lowest to
435 * highest and indexed by the smallest key value that refers to the record.
436 * However, nodes are different: each pointer has two associated keys -- one
437 * indexing the lowest key available in the block(s) below (the same behavior
438 * as the key in a regular btree) and another indexing the highest key
439 * available in the block(s) below. Because records are /not/ sorted by the
440 * highest key, all leaf block updates require us to compute the highest key
441 * that matches any record in the leaf and to recursively update the high keys
442 * in the nodes going further up in the tree, if necessary. Nodes look like
443 * this:
444 *
445 * +--------+-----+-----+-----+-----+-----+-------+-------+-----+
446 * Non-Leaf: | header | lo1 | hi1 | lo2 | hi2 | ... | ptr 1 | ptr 2 | ... |
447 * +--------+-----+-----+-----+-----+-----+-------+-------+-----+
448 *
449 * To perform an interval query on an overlapped tree, perform the usual
450 * depth-first search and use the low and high keys to decide if we can skip
451 * that particular node. If a leaf node is reached, return the records that
452 * intersect the interval. Note that an interval query may return numerous
453 * entries. For a non-overlapped tree, simply search for the record associated
454 * with the lowest key and iterate forward until a non-matching record is
455 * found. Section 14.3 ("Interval Trees") of _Introduction to Algorithms_ by
456 * Cormen, Leiserson, Rivest, and Stein (2nd or 3rd ed. only) discuss this in
457 * more detail.
458 *
459 * Why do we care about overlapping intervals? Let's say you have a bunch of
460 * reverse mapping records on a reflink filesystem:
461 *
462 * 1: +- file A startblock B offset C length D -----------+
463 * 2: +- file E startblock F offset G length H --------------+
464 * 3: +- file I startblock F offset J length K --+
465 * 4: +- file L... --+
466 *
467 * Now say we want to map block (B+D) into file A at offset (C+D). Ideally,
468 * we'd simply increment the length of record 1. But how do we find the record
469 * that ends at (B+D-1) (i.e. record 1)? A LE lookup of (B+D-1) would return
470 * record 3 because the keys are ordered first by startblock. An interval
471 * query would return records 1 and 2 because they both overlap (B+D-1), and
472 * from that we can pick out record 1 as the appropriate left neighbor.
473 *
474 * In the non-overlapped case you can do a LE lookup and decrement the cursor
475 * because a record's interval must end before the next record.
476 */
477
478/*
479 * Return size of the btree block header for this btree instance.
480 */
481static inline size_t xfs_btree_block_len(struct xfs_btree_cur *cur)
482{
483 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
484 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
485 return XFS_BTREE_LBLOCK_CRC_LEN;
486 return XFS_BTREE_LBLOCK_LEN;
487 }
488 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
489 return XFS_BTREE_SBLOCK_CRC_LEN;
490 return XFS_BTREE_SBLOCK_LEN;
491}
492
493/*
494 * Return size of btree block pointers for this btree instance.
495 */
496static inline size_t xfs_btree_ptr_len(struct xfs_btree_cur *cur)
497{
498 return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
499 sizeof(__be64) : sizeof(__be32);
500}
501
502/*
503 * Calculate offset of the n-th record in a btree block.
504 */
505STATIC size_t
506xfs_btree_rec_offset(
507 struct xfs_btree_cur *cur,
508 int n)
509{
510 return xfs_btree_block_len(cur) +
511 (n - 1) * cur->bc_ops->rec_len;
512}
513
514/*
515 * Calculate offset of the n-th key in a btree block.
516 */
517STATIC size_t
518xfs_btree_key_offset(
519 struct xfs_btree_cur *cur,
520 int n)
521{
522 return xfs_btree_block_len(cur) +
523 (n - 1) * cur->bc_ops->key_len;
524}
525
526/*
527 * Calculate offset of the n-th high key in a btree block.
528 */
529STATIC size_t
530xfs_btree_high_key_offset(
531 struct xfs_btree_cur *cur,
532 int n)
533{
534 return xfs_btree_block_len(cur) +
535 (n - 1) * cur->bc_ops->key_len + (cur->bc_ops->key_len / 2);
536}
537
538/*
539 * Calculate offset of the n-th block pointer in a btree block.
540 */
541STATIC size_t
542xfs_btree_ptr_offset(
543 struct xfs_btree_cur *cur,
544 int n,
545 int level)
546{
547 return xfs_btree_block_len(cur) +
548 cur->bc_ops->get_maxrecs(cur, level) * cur->bc_ops->key_len +
549 (n - 1) * xfs_btree_ptr_len(cur);
550}
551
552/*
553 * Return a pointer to the n-th record in the btree block.
554 */
555STATIC union xfs_btree_rec *
556xfs_btree_rec_addr(
557 struct xfs_btree_cur *cur,
558 int n,
559 struct xfs_btree_block *block)
560{
561 return (union xfs_btree_rec *)
562 ((char *)block + xfs_btree_rec_offset(cur, n));
563}
564
565/*
566 * Return a pointer to the n-th key in the btree block.
567 */
568STATIC union xfs_btree_key *
569xfs_btree_key_addr(
570 struct xfs_btree_cur *cur,
571 int n,
572 struct xfs_btree_block *block)
573{
574 return (union xfs_btree_key *)
575 ((char *)block + xfs_btree_key_offset(cur, n));
576}
577
578/*
579 * Return a pointer to the n-th high key in the btree block.
580 */
581STATIC union xfs_btree_key *
582xfs_btree_high_key_addr(
583 struct xfs_btree_cur *cur,
584 int n,
585 struct xfs_btree_block *block)
586{
587 return (union xfs_btree_key *)
588 ((char *)block + xfs_btree_high_key_offset(cur, n));
589}
590
591/*
592 * Return a pointer to the n-th block pointer in the btree block.
593 */
594STATIC union xfs_btree_ptr *
595xfs_btree_ptr_addr(
596 struct xfs_btree_cur *cur,
597 int n,
598 struct xfs_btree_block *block)
599{
600 int level = xfs_btree_get_level(block);
601
602 ASSERT(block->bb_level != 0);
603
604 return (union xfs_btree_ptr *)
605 ((char *)block + xfs_btree_ptr_offset(cur, n, level));
606}
607
608/*
609 * Get the root block which is stored in the inode.
610 *
611 * For now this btree implementation assumes the btree root is always
612 * stored in the if_broot field of an inode fork.
613 */
614STATIC struct xfs_btree_block *
615xfs_btree_get_iroot(
616 struct xfs_btree_cur *cur)
617{
618 struct xfs_ifork *ifp;
619
620 ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, cur->bc_private.b.whichfork);
621 return (struct xfs_btree_block *)ifp->if_broot;
622}
623
624/*
625 * Retrieve the block pointer from the cursor at the given level.
626 * This may be an inode btree root or from a buffer.
627 */
628STATIC struct xfs_btree_block * /* generic btree block pointer */
629xfs_btree_get_block(
630 struct xfs_btree_cur *cur, /* btree cursor */
631 int level, /* level in btree */
632 struct xfs_buf **bpp) /* buffer containing the block */
633{
634 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
635 (level == cur->bc_nlevels - 1)) {
636 *bpp = NULL;
637 return xfs_btree_get_iroot(cur);
638 }
639
640 *bpp = cur->bc_bufs[level];
641 return XFS_BUF_TO_BLOCK(*bpp);
642}
643
644/*
645 * Get a buffer for the block, return it with no data read.
646 * Long-form addressing.
647 */
648xfs_buf_t * /* buffer for fsbno */
649xfs_btree_get_bufl(
650 xfs_mount_t *mp, /* file system mount point */
651 xfs_trans_t *tp, /* transaction pointer */
652 xfs_fsblock_t fsbno, /* file system block number */
653 uint lock) /* lock flags for get_buf */
654{
655 xfs_daddr_t d; /* real disk block address */
656
657 ASSERT(fsbno != NULLFSBLOCK);
658 d = XFS_FSB_TO_DADDR(mp, fsbno);
659 return xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
660}
661
662/*
663 * Get a buffer for the block, return it with no data read.
664 * Short-form addressing.
665 */
666xfs_buf_t * /* buffer for agno/agbno */
667xfs_btree_get_bufs(
668 xfs_mount_t *mp, /* file system mount point */
669 xfs_trans_t *tp, /* transaction pointer */
670 xfs_agnumber_t agno, /* allocation group number */
671 xfs_agblock_t agbno, /* allocation group block number */
672 uint lock) /* lock flags for get_buf */
673{
674 xfs_daddr_t d; /* real disk block address */
675
676 ASSERT(agno != NULLAGNUMBER);
677 ASSERT(agbno != NULLAGBLOCK);
678 d = XFS_AGB_TO_DADDR(mp, agno, agbno);
679 return xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
680}
681
682/*
683 * Check for the cursor referring to the last block at the given level.
684 */
685int /* 1=is last block, 0=not last block */
686xfs_btree_islastblock(
687 xfs_btree_cur_t *cur, /* btree cursor */
688 int level) /* level to check */
689{
690 struct xfs_btree_block *block; /* generic btree block pointer */
691 xfs_buf_t *bp; /* buffer containing block */
692
693 block = xfs_btree_get_block(cur, level, &bp);
694 xfs_btree_check_block(cur, block, level, bp);
695 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
696 return block->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK);
697 else
698 return block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK);
699}
700
701/*
702 * Change the cursor to point to the first record at the given level.
703 * Other levels are unaffected.
704 */
705STATIC int /* success=1, failure=0 */
706xfs_btree_firstrec(
707 xfs_btree_cur_t *cur, /* btree cursor */
708 int level) /* level to change */
709{
710 struct xfs_btree_block *block; /* generic btree block pointer */
711 xfs_buf_t *bp; /* buffer containing block */
712
713 /*
714 * Get the block pointer for this level.
715 */
716 block = xfs_btree_get_block(cur, level, &bp);
717 xfs_btree_check_block(cur, block, level, bp);
718 /*
719 * It's empty, there is no such record.
720 */
721 if (!block->bb_numrecs)
722 return 0;
723 /*
724 * Set the ptr value to 1, that's the first record/key.
725 */
726 cur->bc_ptrs[level] = 1;
727 return 1;
728}
729
730/*
731 * Change the cursor to point to the last record in the current block
732 * at the given level. Other levels are unaffected.
733 */
734STATIC int /* success=1, failure=0 */
735xfs_btree_lastrec(
736 xfs_btree_cur_t *cur, /* btree cursor */
737 int level) /* level to change */
738{
739 struct xfs_btree_block *block; /* generic btree block pointer */
740 xfs_buf_t *bp; /* buffer containing block */
741
742 /*
743 * Get the block pointer for this level.
744 */
745 block = xfs_btree_get_block(cur, level, &bp);
746 xfs_btree_check_block(cur, block, level, bp);
747 /*
748 * It's empty, there is no such record.
749 */
750 if (!block->bb_numrecs)
751 return 0;
752 /*
753 * Set the ptr value to numrecs, that's the last record/key.
754 */
755 cur->bc_ptrs[level] = be16_to_cpu(block->bb_numrecs);
756 return 1;
757}
758
759/*
760 * Compute first and last byte offsets for the fields given.
761 * Interprets the offsets table, which contains struct field offsets.
762 */
763void
764xfs_btree_offsets(
765 __int64_t fields, /* bitmask of fields */
766 const short *offsets, /* table of field offsets */
767 int nbits, /* number of bits to inspect */
768 int *first, /* output: first byte offset */
769 int *last) /* output: last byte offset */
770{
771 int i; /* current bit number */
772 __int64_t imask; /* mask for current bit number */
773
774 ASSERT(fields != 0);
775 /*
776 * Find the lowest bit, so the first byte offset.
777 */
778 for (i = 0, imask = 1LL; ; i++, imask <<= 1) {
779 if (imask & fields) {
780 *first = offsets[i];
781 break;
782 }
783 }
784 /*
785 * Find the highest bit, so the last byte offset.
786 */
787 for (i = nbits - 1, imask = 1LL << i; ; i--, imask >>= 1) {
788 if (imask & fields) {
789 *last = offsets[i + 1] - 1;
790 break;
791 }
792 }
793}
794
795/*
796 * Get a buffer for the block, return it read in.
797 * Long-form addressing.
798 */
799int
800xfs_btree_read_bufl(
801 struct xfs_mount *mp, /* file system mount point */
802 struct xfs_trans *tp, /* transaction pointer */
803 xfs_fsblock_t fsbno, /* file system block number */
804 uint lock, /* lock flags for read_buf */
805 struct xfs_buf **bpp, /* buffer for fsbno */
806 int refval, /* ref count value for buffer */
807 const struct xfs_buf_ops *ops)
808{
809 struct xfs_buf *bp; /* return value */
810 xfs_daddr_t d; /* real disk block address */
811 int error;
812
813 if (!XFS_FSB_SANITY_CHECK(mp, fsbno))
814 return -EFSCORRUPTED;
815 d = XFS_FSB_TO_DADDR(mp, fsbno);
816 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
817 mp->m_bsize, lock, &bp, ops);
818 if (error)
819 return error;
820 if (bp)
821 xfs_buf_set_ref(bp, refval);
822 *bpp = bp;
823 return 0;
824}
825
826/*
827 * Read-ahead the block, don't wait for it, don't return a buffer.
828 * Long-form addressing.
829 */
830/* ARGSUSED */
831void
832xfs_btree_reada_bufl(
833 struct xfs_mount *mp, /* file system mount point */
834 xfs_fsblock_t fsbno, /* file system block number */
835 xfs_extlen_t count, /* count of filesystem blocks */
836 const struct xfs_buf_ops *ops)
837{
838 xfs_daddr_t d;
839
840 ASSERT(fsbno != NULLFSBLOCK);
841 d = XFS_FSB_TO_DADDR(mp, fsbno);
842 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, ops);
843}
844
845/*
846 * Read-ahead the block, don't wait for it, don't return a buffer.
847 * Short-form addressing.
848 */
849/* ARGSUSED */
850void
851xfs_btree_reada_bufs(
852 struct xfs_mount *mp, /* file system mount point */
853 xfs_agnumber_t agno, /* allocation group number */
854 xfs_agblock_t agbno, /* allocation group block number */
855 xfs_extlen_t count, /* count of filesystem blocks */
856 const struct xfs_buf_ops *ops)
857{
858 xfs_daddr_t d;
859
860 ASSERT(agno != NULLAGNUMBER);
861 ASSERT(agbno != NULLAGBLOCK);
862 d = XFS_AGB_TO_DADDR(mp, agno, agbno);
863 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, ops);
864}
865
866STATIC int
867xfs_btree_readahead_lblock(
868 struct xfs_btree_cur *cur,
869 int lr,
870 struct xfs_btree_block *block)
871{
872 int rval = 0;
873 xfs_fsblock_t left = be64_to_cpu(block->bb_u.l.bb_leftsib);
874 xfs_fsblock_t right = be64_to_cpu(block->bb_u.l.bb_rightsib);
875
876 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLFSBLOCK) {
877 xfs_btree_reada_bufl(cur->bc_mp, left, 1,
878 cur->bc_ops->buf_ops);
879 rval++;
880 }
881
882 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLFSBLOCK) {
883 xfs_btree_reada_bufl(cur->bc_mp, right, 1,
884 cur->bc_ops->buf_ops);
885 rval++;
886 }
887
888 return rval;
889}
890
891STATIC int
892xfs_btree_readahead_sblock(
893 struct xfs_btree_cur *cur,
894 int lr,
895 struct xfs_btree_block *block)
896{
897 int rval = 0;
898 xfs_agblock_t left = be32_to_cpu(block->bb_u.s.bb_leftsib);
899 xfs_agblock_t right = be32_to_cpu(block->bb_u.s.bb_rightsib);
900
901
902 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLAGBLOCK) {
903 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
904 left, 1, cur->bc_ops->buf_ops);
905 rval++;
906 }
907
908 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLAGBLOCK) {
909 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
910 right, 1, cur->bc_ops->buf_ops);
911 rval++;
912 }
913
914 return rval;
915}
916
917/*
918 * Read-ahead btree blocks, at the given level.
919 * Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA.
920 */
921STATIC int
922xfs_btree_readahead(
923 struct xfs_btree_cur *cur, /* btree cursor */
924 int lev, /* level in btree */
925 int lr) /* left/right bits */
926{
927 struct xfs_btree_block *block;
928
929 /*
930 * No readahead needed if we are at the root level and the
931 * btree root is stored in the inode.
932 */
933 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
934 (lev == cur->bc_nlevels - 1))
935 return 0;
936
937 if ((cur->bc_ra[lev] | lr) == cur->bc_ra[lev])
938 return 0;
939
940 cur->bc_ra[lev] |= lr;
941 block = XFS_BUF_TO_BLOCK(cur->bc_bufs[lev]);
942
943 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
944 return xfs_btree_readahead_lblock(cur, lr, block);
945 return xfs_btree_readahead_sblock(cur, lr, block);
946}
947
948STATIC xfs_daddr_t
949xfs_btree_ptr_to_daddr(
950 struct xfs_btree_cur *cur,
951 union xfs_btree_ptr *ptr)
952{
953 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
954 ASSERT(ptr->l != cpu_to_be64(NULLFSBLOCK));
955
956 return XFS_FSB_TO_DADDR(cur->bc_mp, be64_to_cpu(ptr->l));
957 } else {
958 ASSERT(cur->bc_private.a.agno != NULLAGNUMBER);
959 ASSERT(ptr->s != cpu_to_be32(NULLAGBLOCK));
960
961 return XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_private.a.agno,
962 be32_to_cpu(ptr->s));
963 }
964}
965
966/*
967 * Readahead @count btree blocks at the given @ptr location.
968 *
969 * We don't need to care about long or short form btrees here as we have a
970 * method of converting the ptr directly to a daddr available to us.
971 */
972STATIC void
973xfs_btree_readahead_ptr(
974 struct xfs_btree_cur *cur,
975 union xfs_btree_ptr *ptr,
976 xfs_extlen_t count)
977{
978 xfs_buf_readahead(cur->bc_mp->m_ddev_targp,
979 xfs_btree_ptr_to_daddr(cur, ptr),
980 cur->bc_mp->m_bsize * count, cur->bc_ops->buf_ops);
981}
982
983/*
984 * Set the buffer for level "lev" in the cursor to bp, releasing
985 * any previous buffer.
986 */
987STATIC void
988xfs_btree_setbuf(
989 xfs_btree_cur_t *cur, /* btree cursor */
990 int lev, /* level in btree */
991 xfs_buf_t *bp) /* new buffer to set */
992{
993 struct xfs_btree_block *b; /* btree block */
994
995 if (cur->bc_bufs[lev])
996 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[lev]);
997 cur->bc_bufs[lev] = bp;
998 cur->bc_ra[lev] = 0;
999
1000 b = XFS_BUF_TO_BLOCK(bp);
1001 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1002 if (b->bb_u.l.bb_leftsib == cpu_to_be64(NULLFSBLOCK))
1003 cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
1004 if (b->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK))
1005 cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
1006 } else {
1007 if (b->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK))
1008 cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
1009 if (b->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK))
1010 cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
1011 }
1012}
1013
1014STATIC int
1015xfs_btree_ptr_is_null(
1016 struct xfs_btree_cur *cur,
1017 union xfs_btree_ptr *ptr)
1018{
1019 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1020 return ptr->l == cpu_to_be64(NULLFSBLOCK);
1021 else
1022 return ptr->s == cpu_to_be32(NULLAGBLOCK);
1023}
1024
1025STATIC void
1026xfs_btree_set_ptr_null(
1027 struct xfs_btree_cur *cur,
1028 union xfs_btree_ptr *ptr)
1029{
1030 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1031 ptr->l = cpu_to_be64(NULLFSBLOCK);
1032 else
1033 ptr->s = cpu_to_be32(NULLAGBLOCK);
1034}
1035
1036/*
1037 * Get/set/init sibling pointers
1038 */
1039STATIC void
1040xfs_btree_get_sibling(
1041 struct xfs_btree_cur *cur,
1042 struct xfs_btree_block *block,
1043 union xfs_btree_ptr *ptr,
1044 int lr)
1045{
1046 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
1047
1048 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1049 if (lr == XFS_BB_RIGHTSIB)
1050 ptr->l = block->bb_u.l.bb_rightsib;
1051 else
1052 ptr->l = block->bb_u.l.bb_leftsib;
1053 } else {
1054 if (lr == XFS_BB_RIGHTSIB)
1055 ptr->s = block->bb_u.s.bb_rightsib;
1056 else
1057 ptr->s = block->bb_u.s.bb_leftsib;
1058 }
1059}
1060
1061STATIC void
1062xfs_btree_set_sibling(
1063 struct xfs_btree_cur *cur,
1064 struct xfs_btree_block *block,
1065 union xfs_btree_ptr *ptr,
1066 int lr)
1067{
1068 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
1069
1070 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1071 if (lr == XFS_BB_RIGHTSIB)
1072 block->bb_u.l.bb_rightsib = ptr->l;
1073 else
1074 block->bb_u.l.bb_leftsib = ptr->l;
1075 } else {
1076 if (lr == XFS_BB_RIGHTSIB)
1077 block->bb_u.s.bb_rightsib = ptr->s;
1078 else
1079 block->bb_u.s.bb_leftsib = ptr->s;
1080 }
1081}
1082
1083void
1084xfs_btree_init_block_int(
1085 struct xfs_mount *mp,
1086 struct xfs_btree_block *buf,
1087 xfs_daddr_t blkno,
1088 __u32 magic,
1089 __u16 level,
1090 __u16 numrecs,
1091 __u64 owner,
1092 unsigned int flags)
1093{
1094 buf->bb_magic = cpu_to_be32(magic);
1095 buf->bb_level = cpu_to_be16(level);
1096 buf->bb_numrecs = cpu_to_be16(numrecs);
1097
1098 if (flags & XFS_BTREE_LONG_PTRS) {
1099 buf->bb_u.l.bb_leftsib = cpu_to_be64(NULLFSBLOCK);
1100 buf->bb_u.l.bb_rightsib = cpu_to_be64(NULLFSBLOCK);
1101 if (flags & XFS_BTREE_CRC_BLOCKS) {
1102 buf->bb_u.l.bb_blkno = cpu_to_be64(blkno);
1103 buf->bb_u.l.bb_owner = cpu_to_be64(owner);
1104 uuid_copy(&buf->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid);
1105 buf->bb_u.l.bb_pad = 0;
1106 buf->bb_u.l.bb_lsn = 0;
1107 }
1108 } else {
1109 /* owner is a 32 bit value on short blocks */
1110 __u32 __owner = (__u32)owner;
1111
1112 buf->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
1113 buf->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
1114 if (flags & XFS_BTREE_CRC_BLOCKS) {
1115 buf->bb_u.s.bb_blkno = cpu_to_be64(blkno);
1116 buf->bb_u.s.bb_owner = cpu_to_be32(__owner);
1117 uuid_copy(&buf->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid);
1118 buf->bb_u.s.bb_lsn = 0;
1119 }
1120 }
1121}
1122
1123void
1124xfs_btree_init_block(
1125 struct xfs_mount *mp,
1126 struct xfs_buf *bp,
1127 __u32 magic,
1128 __u16 level,
1129 __u16 numrecs,
1130 __u64 owner,
1131 unsigned int flags)
1132{
1133 xfs_btree_init_block_int(mp, XFS_BUF_TO_BLOCK(bp), bp->b_bn,
1134 magic, level, numrecs, owner, flags);
1135}
1136
1137STATIC void
1138xfs_btree_init_block_cur(
1139 struct xfs_btree_cur *cur,
1140 struct xfs_buf *bp,
1141 int level,
1142 int numrecs)
1143{
1144 __u64 owner;
1145
1146 /*
1147 * we can pull the owner from the cursor right now as the different
1148 * owners align directly with the pointer size of the btree. This may
1149 * change in future, but is safe for current users of the generic btree
1150 * code.
1151 */
1152 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1153 owner = cur->bc_private.b.ip->i_ino;
1154 else
1155 owner = cur->bc_private.a.agno;
1156
1157 xfs_btree_init_block_int(cur->bc_mp, XFS_BUF_TO_BLOCK(bp), bp->b_bn,
1158 xfs_btree_magic(cur), level, numrecs,
1159 owner, cur->bc_flags);
1160}
1161
1162/*
1163 * Return true if ptr is the last record in the btree and
1164 * we need to track updates to this record. The decision
1165 * will be further refined in the update_lastrec method.
1166 */
1167STATIC int
1168xfs_btree_is_lastrec(
1169 struct xfs_btree_cur *cur,
1170 struct xfs_btree_block *block,
1171 int level)
1172{
1173 union xfs_btree_ptr ptr;
1174
1175 if (level > 0)
1176 return 0;
1177 if (!(cur->bc_flags & XFS_BTREE_LASTREC_UPDATE))
1178 return 0;
1179
1180 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1181 if (!xfs_btree_ptr_is_null(cur, &ptr))
1182 return 0;
1183 return 1;
1184}
1185
1186STATIC void
1187xfs_btree_buf_to_ptr(
1188 struct xfs_btree_cur *cur,
1189 struct xfs_buf *bp,
1190 union xfs_btree_ptr *ptr)
1191{
1192 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1193 ptr->l = cpu_to_be64(XFS_DADDR_TO_FSB(cur->bc_mp,
1194 XFS_BUF_ADDR(bp)));
1195 else {
1196 ptr->s = cpu_to_be32(xfs_daddr_to_agbno(cur->bc_mp,
1197 XFS_BUF_ADDR(bp)));
1198 }
1199}
1200
1201STATIC void
1202xfs_btree_set_refs(
1203 struct xfs_btree_cur *cur,
1204 struct xfs_buf *bp)
1205{
1206 switch (cur->bc_btnum) {
1207 case XFS_BTNUM_BNO:
1208 case XFS_BTNUM_CNT:
1209 xfs_buf_set_ref(bp, XFS_ALLOC_BTREE_REF);
1210 break;
1211 case XFS_BTNUM_INO:
1212 case XFS_BTNUM_FINO:
1213 xfs_buf_set_ref(bp, XFS_INO_BTREE_REF);
1214 break;
1215 case XFS_BTNUM_BMAP:
1216 xfs_buf_set_ref(bp, XFS_BMAP_BTREE_REF);
1217 break;
1218 case XFS_BTNUM_RMAP:
1219 xfs_buf_set_ref(bp, XFS_RMAP_BTREE_REF);
1220 break;
1221 case XFS_BTNUM_REFC:
1222 xfs_buf_set_ref(bp, XFS_REFC_BTREE_REF);
1223 break;
1224 default:
1225 ASSERT(0);
1226 }
1227}
1228
1229STATIC int
1230xfs_btree_get_buf_block(
1231 struct xfs_btree_cur *cur,
1232 union xfs_btree_ptr *ptr,
1233 int flags,
1234 struct xfs_btree_block **block,
1235 struct xfs_buf **bpp)
1236{
1237 struct xfs_mount *mp = cur->bc_mp;
1238 xfs_daddr_t d;
1239
1240 /* need to sort out how callers deal with failures first */
1241 ASSERT(!(flags & XBF_TRYLOCK));
1242
1243 d = xfs_btree_ptr_to_daddr(cur, ptr);
1244 *bpp = xfs_trans_get_buf(cur->bc_tp, mp->m_ddev_targp, d,
1245 mp->m_bsize, flags);
1246
1247 if (!*bpp)
1248 return -ENOMEM;
1249
1250 (*bpp)->b_ops = cur->bc_ops->buf_ops;
1251 *block = XFS_BUF_TO_BLOCK(*bpp);
1252 return 0;
1253}
1254
1255/*
1256 * Read in the buffer at the given ptr and return the buffer and
1257 * the block pointer within the buffer.
1258 */
1259STATIC int
1260xfs_btree_read_buf_block(
1261 struct xfs_btree_cur *cur,
1262 union xfs_btree_ptr *ptr,
1263 int flags,
1264 struct xfs_btree_block **block,
1265 struct xfs_buf **bpp)
1266{
1267 struct xfs_mount *mp = cur->bc_mp;
1268 xfs_daddr_t d;
1269 int error;
1270
1271 /* need to sort out how callers deal with failures first */
1272 ASSERT(!(flags & XBF_TRYLOCK));
1273
1274 d = xfs_btree_ptr_to_daddr(cur, ptr);
1275 error = xfs_trans_read_buf(mp, cur->bc_tp, mp->m_ddev_targp, d,
1276 mp->m_bsize, flags, bpp,
1277 cur->bc_ops->buf_ops);
1278 if (error)
1279 return error;
1280
1281 xfs_btree_set_refs(cur, *bpp);
1282 *block = XFS_BUF_TO_BLOCK(*bpp);
1283 return 0;
1284}
1285
1286/*
1287 * Copy keys from one btree block to another.
1288 */
1289STATIC void
1290xfs_btree_copy_keys(
1291 struct xfs_btree_cur *cur,
1292 union xfs_btree_key *dst_key,
1293 union xfs_btree_key *src_key,
1294 int numkeys)
1295{
1296 ASSERT(numkeys >= 0);
1297 memcpy(dst_key, src_key, numkeys * cur->bc_ops->key_len);
1298}
1299
1300/*
1301 * Copy records from one btree block to another.
1302 */
1303STATIC void
1304xfs_btree_copy_recs(
1305 struct xfs_btree_cur *cur,
1306 union xfs_btree_rec *dst_rec,
1307 union xfs_btree_rec *src_rec,
1308 int numrecs)
1309{
1310 ASSERT(numrecs >= 0);
1311 memcpy(dst_rec, src_rec, numrecs * cur->bc_ops->rec_len);
1312}
1313
1314/*
1315 * Copy block pointers from one btree block to another.
1316 */
1317STATIC void
1318xfs_btree_copy_ptrs(
1319 struct xfs_btree_cur *cur,
1320 union xfs_btree_ptr *dst_ptr,
1321 union xfs_btree_ptr *src_ptr,
1322 int numptrs)
1323{
1324 ASSERT(numptrs >= 0);
1325 memcpy(dst_ptr, src_ptr, numptrs * xfs_btree_ptr_len(cur));
1326}
1327
1328/*
1329 * Shift keys one index left/right inside a single btree block.
1330 */
1331STATIC void
1332xfs_btree_shift_keys(
1333 struct xfs_btree_cur *cur,
1334 union xfs_btree_key *key,
1335 int dir,
1336 int numkeys)
1337{
1338 char *dst_key;
1339
1340 ASSERT(numkeys >= 0);
1341 ASSERT(dir == 1 || dir == -1);
1342
1343 dst_key = (char *)key + (dir * cur->bc_ops->key_len);
1344 memmove(dst_key, key, numkeys * cur->bc_ops->key_len);
1345}
1346
1347/*
1348 * Shift records one index left/right inside a single btree block.
1349 */
1350STATIC void
1351xfs_btree_shift_recs(
1352 struct xfs_btree_cur *cur,
1353 union xfs_btree_rec *rec,
1354 int dir,
1355 int numrecs)
1356{
1357 char *dst_rec;
1358
1359 ASSERT(numrecs >= 0);
1360 ASSERT(dir == 1 || dir == -1);
1361
1362 dst_rec = (char *)rec + (dir * cur->bc_ops->rec_len);
1363 memmove(dst_rec, rec, numrecs * cur->bc_ops->rec_len);
1364}
1365
1366/*
1367 * Shift block pointers one index left/right inside a single btree block.
1368 */
1369STATIC void
1370xfs_btree_shift_ptrs(
1371 struct xfs_btree_cur *cur,
1372 union xfs_btree_ptr *ptr,
1373 int dir,
1374 int numptrs)
1375{
1376 char *dst_ptr;
1377
1378 ASSERT(numptrs >= 0);
1379 ASSERT(dir == 1 || dir == -1);
1380
1381 dst_ptr = (char *)ptr + (dir * xfs_btree_ptr_len(cur));
1382 memmove(dst_ptr, ptr, numptrs * xfs_btree_ptr_len(cur));
1383}
1384
1385/*
1386 * Log key values from the btree block.
1387 */
1388STATIC void
1389xfs_btree_log_keys(
1390 struct xfs_btree_cur *cur,
1391 struct xfs_buf *bp,
1392 int first,
1393 int last)
1394{
1395 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1396 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1397
1398 if (bp) {
1399 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1400 xfs_trans_log_buf(cur->bc_tp, bp,
1401 xfs_btree_key_offset(cur, first),
1402 xfs_btree_key_offset(cur, last + 1) - 1);
1403 } else {
1404 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1405 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1406 }
1407
1408 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1409}
1410
1411/*
1412 * Log record values from the btree block.
1413 */
1414void
1415xfs_btree_log_recs(
1416 struct xfs_btree_cur *cur,
1417 struct xfs_buf *bp,
1418 int first,
1419 int last)
1420{
1421 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1422 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1423
1424 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1425 xfs_trans_log_buf(cur->bc_tp, bp,
1426 xfs_btree_rec_offset(cur, first),
1427 xfs_btree_rec_offset(cur, last + 1) - 1);
1428
1429 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1430}
1431
1432/*
1433 * Log block pointer fields from a btree block (nonleaf).
1434 */
1435STATIC void
1436xfs_btree_log_ptrs(
1437 struct xfs_btree_cur *cur, /* btree cursor */
1438 struct xfs_buf *bp, /* buffer containing btree block */
1439 int first, /* index of first pointer to log */
1440 int last) /* index of last pointer to log */
1441{
1442 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1443 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1444
1445 if (bp) {
1446 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
1447 int level = xfs_btree_get_level(block);
1448
1449 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1450 xfs_trans_log_buf(cur->bc_tp, bp,
1451 xfs_btree_ptr_offset(cur, first, level),
1452 xfs_btree_ptr_offset(cur, last + 1, level) - 1);
1453 } else {
1454 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1455 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1456 }
1457
1458 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1459}
1460
1461/*
1462 * Log fields from a btree block header.
1463 */
1464void
1465xfs_btree_log_block(
1466 struct xfs_btree_cur *cur, /* btree cursor */
1467 struct xfs_buf *bp, /* buffer containing btree block */
1468 int fields) /* mask of fields: XFS_BB_... */
1469{
1470 int first; /* first byte offset logged */
1471 int last; /* last byte offset logged */
1472 static const short soffsets[] = { /* table of offsets (short) */
1473 offsetof(struct xfs_btree_block, bb_magic),
1474 offsetof(struct xfs_btree_block, bb_level),
1475 offsetof(struct xfs_btree_block, bb_numrecs),
1476 offsetof(struct xfs_btree_block, bb_u.s.bb_leftsib),
1477 offsetof(struct xfs_btree_block, bb_u.s.bb_rightsib),
1478 offsetof(struct xfs_btree_block, bb_u.s.bb_blkno),
1479 offsetof(struct xfs_btree_block, bb_u.s.bb_lsn),
1480 offsetof(struct xfs_btree_block, bb_u.s.bb_uuid),
1481 offsetof(struct xfs_btree_block, bb_u.s.bb_owner),
1482 offsetof(struct xfs_btree_block, bb_u.s.bb_crc),
1483 XFS_BTREE_SBLOCK_CRC_LEN
1484 };
1485 static const short loffsets[] = { /* table of offsets (long) */
1486 offsetof(struct xfs_btree_block, bb_magic),
1487 offsetof(struct xfs_btree_block, bb_level),
1488 offsetof(struct xfs_btree_block, bb_numrecs),
1489 offsetof(struct xfs_btree_block, bb_u.l.bb_leftsib),
1490 offsetof(struct xfs_btree_block, bb_u.l.bb_rightsib),
1491 offsetof(struct xfs_btree_block, bb_u.l.bb_blkno),
1492 offsetof(struct xfs_btree_block, bb_u.l.bb_lsn),
1493 offsetof(struct xfs_btree_block, bb_u.l.bb_uuid),
1494 offsetof(struct xfs_btree_block, bb_u.l.bb_owner),
1495 offsetof(struct xfs_btree_block, bb_u.l.bb_crc),
1496 offsetof(struct xfs_btree_block, bb_u.l.bb_pad),
1497 XFS_BTREE_LBLOCK_CRC_LEN
1498 };
1499
1500 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1501 XFS_BTREE_TRACE_ARGBI(cur, bp, fields);
1502
1503 if (bp) {
1504 int nbits;
1505
1506 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) {
1507 /*
1508 * We don't log the CRC when updating a btree
1509 * block but instead recreate it during log
1510 * recovery. As the log buffers have checksums
1511 * of their own this is safe and avoids logging a crc
1512 * update in a lot of places.
1513 */
1514 if (fields == XFS_BB_ALL_BITS)
1515 fields = XFS_BB_ALL_BITS_CRC;
1516 nbits = XFS_BB_NUM_BITS_CRC;
1517 } else {
1518 nbits = XFS_BB_NUM_BITS;
1519 }
1520 xfs_btree_offsets(fields,
1521 (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
1522 loffsets : soffsets,
1523 nbits, &first, &last);
1524 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1525 xfs_trans_log_buf(cur->bc_tp, bp, first, last);
1526 } else {
1527 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1528 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1529 }
1530
1531 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1532}
1533
1534/*
1535 * Increment cursor by one record at the level.
1536 * For nonzero levels the leaf-ward information is untouched.
1537 */
1538int /* error */
1539xfs_btree_increment(
1540 struct xfs_btree_cur *cur,
1541 int level,
1542 int *stat) /* success/failure */
1543{
1544 struct xfs_btree_block *block;
1545 union xfs_btree_ptr ptr;
1546 struct xfs_buf *bp;
1547 int error; /* error return value */
1548 int lev;
1549
1550 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1551 XFS_BTREE_TRACE_ARGI(cur, level);
1552
1553 ASSERT(level < cur->bc_nlevels);
1554
1555 /* Read-ahead to the right at this level. */
1556 xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
1557
1558 /* Get a pointer to the btree block. */
1559 block = xfs_btree_get_block(cur, level, &bp);
1560
1561#ifdef DEBUG
1562 error = xfs_btree_check_block(cur, block, level, bp);
1563 if (error)
1564 goto error0;
1565#endif
1566
1567 /* We're done if we remain in the block after the increment. */
1568 if (++cur->bc_ptrs[level] <= xfs_btree_get_numrecs(block))
1569 goto out1;
1570
1571 /* Fail if we just went off the right edge of the tree. */
1572 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1573 if (xfs_btree_ptr_is_null(cur, &ptr))
1574 goto out0;
1575
1576 XFS_BTREE_STATS_INC(cur, increment);
1577
1578 /*
1579 * March up the tree incrementing pointers.
1580 * Stop when we don't go off the right edge of a block.
1581 */
1582 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1583 block = xfs_btree_get_block(cur, lev, &bp);
1584
1585#ifdef DEBUG
1586 error = xfs_btree_check_block(cur, block, lev, bp);
1587 if (error)
1588 goto error0;
1589#endif
1590
1591 if (++cur->bc_ptrs[lev] <= xfs_btree_get_numrecs(block))
1592 break;
1593
1594 /* Read-ahead the right block for the next loop. */
1595 xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA);
1596 }
1597
1598 /*
1599 * If we went off the root then we are either seriously
1600 * confused or have the tree root in an inode.
1601 */
1602 if (lev == cur->bc_nlevels) {
1603 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1604 goto out0;
1605 ASSERT(0);
1606 error = -EFSCORRUPTED;
1607 goto error0;
1608 }
1609 ASSERT(lev < cur->bc_nlevels);
1610
1611 /*
1612 * Now walk back down the tree, fixing up the cursor's buffer
1613 * pointers and key numbers.
1614 */
1615 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1616 union xfs_btree_ptr *ptrp;
1617
1618 ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1619 --lev;
1620 error = xfs_btree_read_buf_block(cur, ptrp, 0, &block, &bp);
1621 if (error)
1622 goto error0;
1623
1624 xfs_btree_setbuf(cur, lev, bp);
1625 cur->bc_ptrs[lev] = 1;
1626 }
1627out1:
1628 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1629 *stat = 1;
1630 return 0;
1631
1632out0:
1633 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1634 *stat = 0;
1635 return 0;
1636
1637error0:
1638 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1639 return error;
1640}
1641
1642/*
1643 * Decrement cursor by one record at the level.
1644 * For nonzero levels the leaf-ward information is untouched.
1645 */
1646int /* error */
1647xfs_btree_decrement(
1648 struct xfs_btree_cur *cur,
1649 int level,
1650 int *stat) /* success/failure */
1651{
1652 struct xfs_btree_block *block;
1653 xfs_buf_t *bp;
1654 int error; /* error return value */
1655 int lev;
1656 union xfs_btree_ptr ptr;
1657
1658 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1659 XFS_BTREE_TRACE_ARGI(cur, level);
1660
1661 ASSERT(level < cur->bc_nlevels);
1662
1663 /* Read-ahead to the left at this level. */
1664 xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA);
1665
1666 /* We're done if we remain in the block after the decrement. */
1667 if (--cur->bc_ptrs[level] > 0)
1668 goto out1;
1669
1670 /* Get a pointer to the btree block. */
1671 block = xfs_btree_get_block(cur, level, &bp);
1672
1673#ifdef DEBUG
1674 error = xfs_btree_check_block(cur, block, level, bp);
1675 if (error)
1676 goto error0;
1677#endif
1678
1679 /* Fail if we just went off the left edge of the tree. */
1680 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
1681 if (xfs_btree_ptr_is_null(cur, &ptr))
1682 goto out0;
1683
1684 XFS_BTREE_STATS_INC(cur, decrement);
1685
1686 /*
1687 * March up the tree decrementing pointers.
1688 * Stop when we don't go off the left edge of a block.
1689 */
1690 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1691 if (--cur->bc_ptrs[lev] > 0)
1692 break;
1693 /* Read-ahead the left block for the next loop. */
1694 xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA);
1695 }
1696
1697 /*
1698 * If we went off the root then we are seriously confused.
1699 * or the root of the tree is in an inode.
1700 */
1701 if (lev == cur->bc_nlevels) {
1702 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1703 goto out0;
1704 ASSERT(0);
1705 error = -EFSCORRUPTED;
1706 goto error0;
1707 }
1708 ASSERT(lev < cur->bc_nlevels);
1709
1710 /*
1711 * Now walk back down the tree, fixing up the cursor's buffer
1712 * pointers and key numbers.
1713 */
1714 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1715 union xfs_btree_ptr *ptrp;
1716
1717 ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1718 --lev;
1719 error = xfs_btree_read_buf_block(cur, ptrp, 0, &block, &bp);
1720 if (error)
1721 goto error0;
1722 xfs_btree_setbuf(cur, lev, bp);
1723 cur->bc_ptrs[lev] = xfs_btree_get_numrecs(block);
1724 }
1725out1:
1726 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1727 *stat = 1;
1728 return 0;
1729
1730out0:
1731 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1732 *stat = 0;
1733 return 0;
1734
1735error0:
1736 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1737 return error;
1738}
1739
1740STATIC int
1741xfs_btree_lookup_get_block(
1742 struct xfs_btree_cur *cur, /* btree cursor */
1743 int level, /* level in the btree */
1744 union xfs_btree_ptr *pp, /* ptr to btree block */
1745 struct xfs_btree_block **blkp) /* return btree block */
1746{
1747 struct xfs_buf *bp; /* buffer pointer for btree block */
1748 int error = 0;
1749
1750 /* special case the root block if in an inode */
1751 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1752 (level == cur->bc_nlevels - 1)) {
1753 *blkp = xfs_btree_get_iroot(cur);
1754 return 0;
1755 }
1756
1757 /*
1758 * If the old buffer at this level for the disk address we are
1759 * looking for re-use it.
1760 *
1761 * Otherwise throw it away and get a new one.
1762 */
1763 bp = cur->bc_bufs[level];
1764 if (bp && XFS_BUF_ADDR(bp) == xfs_btree_ptr_to_daddr(cur, pp)) {
1765 *blkp = XFS_BUF_TO_BLOCK(bp);
1766 return 0;
1767 }
1768
1769 error = xfs_btree_read_buf_block(cur, pp, 0, blkp, &bp);
1770 if (error)
1771 return error;
1772
1773 /* Check the inode owner since the verifiers don't. */
1774 if (xfs_sb_version_hascrc(&cur->bc_mp->m_sb) &&
1775 (cur->bc_flags & XFS_BTREE_LONG_PTRS) &&
1776 be64_to_cpu((*blkp)->bb_u.l.bb_owner) !=
1777 cur->bc_private.b.ip->i_ino)
1778 goto out_bad;
1779
1780 /* Did we get the level we were looking for? */
1781 if (be16_to_cpu((*blkp)->bb_level) != level)
1782 goto out_bad;
1783
1784 /* Check that internal nodes have at least one record. */
1785 if (level != 0 && be16_to_cpu((*blkp)->bb_numrecs) == 0)
1786 goto out_bad;
1787
1788 xfs_btree_setbuf(cur, level, bp);
1789 return 0;
1790
1791out_bad:
1792 *blkp = NULL;
1793 xfs_trans_brelse(cur->bc_tp, bp);
1794 return -EFSCORRUPTED;
1795}
1796
1797/*
1798 * Get current search key. For level 0 we don't actually have a key
1799 * structure so we make one up from the record. For all other levels
1800 * we just return the right key.
1801 */
1802STATIC union xfs_btree_key *
1803xfs_lookup_get_search_key(
1804 struct xfs_btree_cur *cur,
1805 int level,
1806 int keyno,
1807 struct xfs_btree_block *block,
1808 union xfs_btree_key *kp)
1809{
1810 if (level == 0) {
1811 cur->bc_ops->init_key_from_rec(kp,
1812 xfs_btree_rec_addr(cur, keyno, block));
1813 return kp;
1814 }
1815
1816 return xfs_btree_key_addr(cur, keyno, block);
1817}
1818
1819/*
1820 * Lookup the record. The cursor is made to point to it, based on dir.
1821 * stat is set to 0 if can't find any such record, 1 for success.
1822 */
1823int /* error */
1824xfs_btree_lookup(
1825 struct xfs_btree_cur *cur, /* btree cursor */
1826 xfs_lookup_t dir, /* <=, ==, or >= */
1827 int *stat) /* success/failure */
1828{
1829 struct xfs_btree_block *block; /* current btree block */
1830 __int64_t diff; /* difference for the current key */
1831 int error; /* error return value */
1832 int keyno; /* current key number */
1833 int level; /* level in the btree */
1834 union xfs_btree_ptr *pp; /* ptr to btree block */
1835 union xfs_btree_ptr ptr; /* ptr to btree block */
1836
1837 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1838 XFS_BTREE_TRACE_ARGI(cur, dir);
1839
1840 XFS_BTREE_STATS_INC(cur, lookup);
1841
1842 /* No such thing as a zero-level tree. */
1843 if (cur->bc_nlevels == 0)
1844 return -EFSCORRUPTED;
1845
1846 block = NULL;
1847 keyno = 0;
1848
1849 /* initialise start pointer from cursor */
1850 cur->bc_ops->init_ptr_from_cur(cur, &ptr);
1851 pp = &ptr;
1852
1853 /*
1854 * Iterate over each level in the btree, starting at the root.
1855 * For each level above the leaves, find the key we need, based
1856 * on the lookup record, then follow the corresponding block
1857 * pointer down to the next level.
1858 */
1859 for (level = cur->bc_nlevels - 1, diff = 1; level >= 0; level--) {
1860 /* Get the block we need to do the lookup on. */
1861 error = xfs_btree_lookup_get_block(cur, level, pp, &block);
1862 if (error)
1863 goto error0;
1864
1865 if (diff == 0) {
1866 /*
1867 * If we already had a key match at a higher level, we
1868 * know we need to use the first entry in this block.
1869 */
1870 keyno = 1;
1871 } else {
1872 /* Otherwise search this block. Do a binary search. */
1873
1874 int high; /* high entry number */
1875 int low; /* low entry number */
1876
1877 /* Set low and high entry numbers, 1-based. */
1878 low = 1;
1879 high = xfs_btree_get_numrecs(block);
1880 if (!high) {
1881 /* Block is empty, must be an empty leaf. */
1882 ASSERT(level == 0 && cur->bc_nlevels == 1);
1883
1884 cur->bc_ptrs[0] = dir != XFS_LOOKUP_LE;
1885 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1886 *stat = 0;
1887 return 0;
1888 }
1889
1890 /* Binary search the block. */
1891 while (low <= high) {
1892 union xfs_btree_key key;
1893 union xfs_btree_key *kp;
1894
1895 XFS_BTREE_STATS_INC(cur, compare);
1896
1897 /* keyno is average of low and high. */
1898 keyno = (low + high) >> 1;
1899
1900 /* Get current search key */
1901 kp = xfs_lookup_get_search_key(cur, level,
1902 keyno, block, &key);
1903
1904 /*
1905 * Compute difference to get next direction:
1906 * - less than, move right
1907 * - greater than, move left
1908 * - equal, we're done
1909 */
1910 diff = cur->bc_ops->key_diff(cur, kp);
1911 if (diff < 0)
1912 low = keyno + 1;
1913 else if (diff > 0)
1914 high = keyno - 1;
1915 else
1916 break;
1917 }
1918 }
1919
1920 /*
1921 * If there are more levels, set up for the next level
1922 * by getting the block number and filling in the cursor.
1923 */
1924 if (level > 0) {
1925 /*
1926 * If we moved left, need the previous key number,
1927 * unless there isn't one.
1928 */
1929 if (diff > 0 && --keyno < 1)
1930 keyno = 1;
1931 pp = xfs_btree_ptr_addr(cur, keyno, block);
1932
1933#ifdef DEBUG
1934 error = xfs_btree_check_ptr(cur, pp, 0, level);
1935 if (error)
1936 goto error0;
1937#endif
1938 cur->bc_ptrs[level] = keyno;
1939 }
1940 }
1941
1942 /* Done with the search. See if we need to adjust the results. */
1943 if (dir != XFS_LOOKUP_LE && diff < 0) {
1944 keyno++;
1945 /*
1946 * If ge search and we went off the end of the block, but it's
1947 * not the last block, we're in the wrong block.
1948 */
1949 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1950 if (dir == XFS_LOOKUP_GE &&
1951 keyno > xfs_btree_get_numrecs(block) &&
1952 !xfs_btree_ptr_is_null(cur, &ptr)) {
1953 int i;
1954
1955 cur->bc_ptrs[0] = keyno;
1956 error = xfs_btree_increment(cur, 0, &i);
1957 if (error)
1958 goto error0;
1959 XFS_WANT_CORRUPTED_RETURN(cur->bc_mp, i == 1);
1960 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1961 *stat = 1;
1962 return 0;
1963 }
1964 } else if (dir == XFS_LOOKUP_LE && diff > 0)
1965 keyno--;
1966 cur->bc_ptrs[0] = keyno;
1967
1968 /* Return if we succeeded or not. */
1969 if (keyno == 0 || keyno > xfs_btree_get_numrecs(block))
1970 *stat = 0;
1971 else if (dir != XFS_LOOKUP_EQ || diff == 0)
1972 *stat = 1;
1973 else
1974 *stat = 0;
1975 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1976 return 0;
1977
1978error0:
1979 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1980 return error;
1981}
1982
1983/* Find the high key storage area from a regular key. */
1984STATIC union xfs_btree_key *
1985xfs_btree_high_key_from_key(
1986 struct xfs_btree_cur *cur,
1987 union xfs_btree_key *key)
1988{
1989 ASSERT(cur->bc_flags & XFS_BTREE_OVERLAPPING);
1990 return (union xfs_btree_key *)((char *)key +
1991 (cur->bc_ops->key_len / 2));
1992}
1993
1994/* Determine the low (and high if overlapped) keys of a leaf block */
1995STATIC void
1996xfs_btree_get_leaf_keys(
1997 struct xfs_btree_cur *cur,
1998 struct xfs_btree_block *block,
1999 union xfs_btree_key *key)
2000{
2001 union xfs_btree_key max_hkey;
2002 union xfs_btree_key hkey;
2003 union xfs_btree_rec *rec;
2004 union xfs_btree_key *high;
2005 int n;
2006
2007 rec = xfs_btree_rec_addr(cur, 1, block);
2008 cur->bc_ops->init_key_from_rec(key, rec);
2009
2010 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2011
2012 cur->bc_ops->init_high_key_from_rec(&max_hkey, rec);
2013 for (n = 2; n <= xfs_btree_get_numrecs(block); n++) {
2014 rec = xfs_btree_rec_addr(cur, n, block);
2015 cur->bc_ops->init_high_key_from_rec(&hkey, rec);
2016 if (cur->bc_ops->diff_two_keys(cur, &hkey, &max_hkey)
2017 > 0)
2018 max_hkey = hkey;
2019 }
2020
2021 high = xfs_btree_high_key_from_key(cur, key);
2022 memcpy(high, &max_hkey, cur->bc_ops->key_len / 2);
2023 }
2024}
2025
2026/* Determine the low (and high if overlapped) keys of a node block */
2027STATIC void
2028xfs_btree_get_node_keys(
2029 struct xfs_btree_cur *cur,
2030 struct xfs_btree_block *block,
2031 union xfs_btree_key *key)
2032{
2033 union xfs_btree_key *hkey;
2034 union xfs_btree_key *max_hkey;
2035 union xfs_btree_key *high;
2036 int n;
2037
2038 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2039 memcpy(key, xfs_btree_key_addr(cur, 1, block),
2040 cur->bc_ops->key_len / 2);
2041
2042 max_hkey = xfs_btree_high_key_addr(cur, 1, block);
2043 for (n = 2; n <= xfs_btree_get_numrecs(block); n++) {
2044 hkey = xfs_btree_high_key_addr(cur, n, block);
2045 if (cur->bc_ops->diff_two_keys(cur, hkey, max_hkey) > 0)
2046 max_hkey = hkey;
2047 }
2048
2049 high = xfs_btree_high_key_from_key(cur, key);
2050 memcpy(high, max_hkey, cur->bc_ops->key_len / 2);
2051 } else {
2052 memcpy(key, xfs_btree_key_addr(cur, 1, block),
2053 cur->bc_ops->key_len);
2054 }
2055}
2056
2057/* Derive the keys for any btree block. */
2058STATIC void
2059xfs_btree_get_keys(
2060 struct xfs_btree_cur *cur,
2061 struct xfs_btree_block *block,
2062 union xfs_btree_key *key)
2063{
2064 if (be16_to_cpu(block->bb_level) == 0)
2065 xfs_btree_get_leaf_keys(cur, block, key);
2066 else
2067 xfs_btree_get_node_keys(cur, block, key);
2068}
2069
2070/*
2071 * Decide if we need to update the parent keys of a btree block. For
2072 * a standard btree this is only necessary if we're updating the first
2073 * record/key. For an overlapping btree, we must always update the
2074 * keys because the highest key can be in any of the records or keys
2075 * in the block.
2076 */
2077static inline bool
2078xfs_btree_needs_key_update(
2079 struct xfs_btree_cur *cur,
2080 int ptr)
2081{
2082 return (cur->bc_flags & XFS_BTREE_OVERLAPPING) || ptr == 1;
2083}
2084
2085/*
2086 * Update the low and high parent keys of the given level, progressing
2087 * towards the root. If force_all is false, stop if the keys for a given
2088 * level do not need updating.
2089 */
2090STATIC int
2091__xfs_btree_updkeys(
2092 struct xfs_btree_cur *cur,
2093 int level,
2094 struct xfs_btree_block *block,
2095 struct xfs_buf *bp0,
2096 bool force_all)
2097{
2098 union xfs_btree_key key; /* keys from current level */
2099 union xfs_btree_key *lkey; /* keys from the next level up */
2100 union xfs_btree_key *hkey;
2101 union xfs_btree_key *nlkey; /* keys from the next level up */
2102 union xfs_btree_key *nhkey;
2103 struct xfs_buf *bp;
2104 int ptr;
2105
2106 ASSERT(cur->bc_flags & XFS_BTREE_OVERLAPPING);
2107
2108 /* Exit if there aren't any parent levels to update. */
2109 if (level + 1 >= cur->bc_nlevels)
2110 return 0;
2111
2112 trace_xfs_btree_updkeys(cur, level, bp0);
2113
2114 lkey = &key;
2115 hkey = xfs_btree_high_key_from_key(cur, lkey);
2116 xfs_btree_get_keys(cur, block, lkey);
2117 for (level++; level < cur->bc_nlevels; level++) {
2118#ifdef DEBUG
2119 int error;
2120#endif
2121 block = xfs_btree_get_block(cur, level, &bp);
2122 trace_xfs_btree_updkeys(cur, level, bp);
2123#ifdef DEBUG
2124 error = xfs_btree_check_block(cur, block, level, bp);
2125 if (error) {
2126 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2127 return error;
2128 }
2129#endif
2130 ptr = cur->bc_ptrs[level];
2131 nlkey = xfs_btree_key_addr(cur, ptr, block);
2132 nhkey = xfs_btree_high_key_addr(cur, ptr, block);
2133 if (!force_all &&
2134 !(cur->bc_ops->diff_two_keys(cur, nlkey, lkey) != 0 ||
2135 cur->bc_ops->diff_two_keys(cur, nhkey, hkey) != 0))
2136 break;
2137 xfs_btree_copy_keys(cur, nlkey, lkey, 1);
2138 xfs_btree_log_keys(cur, bp, ptr, ptr);
2139 if (level + 1 >= cur->bc_nlevels)
2140 break;
2141 xfs_btree_get_node_keys(cur, block, lkey);
2142 }
2143
2144 return 0;
2145}
2146
2147/* Update all the keys from some level in cursor back to the root. */
2148STATIC int
2149xfs_btree_updkeys_force(
2150 struct xfs_btree_cur *cur,
2151 int level)
2152{
2153 struct xfs_buf *bp;
2154 struct xfs_btree_block *block;
2155
2156 block = xfs_btree_get_block(cur, level, &bp);
2157 return __xfs_btree_updkeys(cur, level, block, bp, true);
2158}
2159
2160/*
2161 * Update the parent keys of the given level, progressing towards the root.
2162 */
2163STATIC int
2164xfs_btree_update_keys(
2165 struct xfs_btree_cur *cur,
2166 int level)
2167{
2168 struct xfs_btree_block *block;
2169 struct xfs_buf *bp;
2170 union xfs_btree_key *kp;
2171 union xfs_btree_key key;
2172 int ptr;
2173
2174 ASSERT(level >= 0);
2175
2176 block = xfs_btree_get_block(cur, level, &bp);
2177 if (cur->bc_flags & XFS_BTREE_OVERLAPPING)
2178 return __xfs_btree_updkeys(cur, level, block, bp, false);
2179
2180 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2181 XFS_BTREE_TRACE_ARGIK(cur, level, keyp);
2182
2183 /*
2184 * Go up the tree from this level toward the root.
2185 * At each level, update the key value to the value input.
2186 * Stop when we reach a level where the cursor isn't pointing
2187 * at the first entry in the block.
2188 */
2189 xfs_btree_get_keys(cur, block, &key);
2190 for (level++, ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) {
2191#ifdef DEBUG
2192 int error;
2193#endif
2194 block = xfs_btree_get_block(cur, level, &bp);
2195#ifdef DEBUG
2196 error = xfs_btree_check_block(cur, block, level, bp);
2197 if (error) {
2198 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2199 return error;
2200 }
2201#endif
2202 ptr = cur->bc_ptrs[level];
2203 kp = xfs_btree_key_addr(cur, ptr, block);
2204 xfs_btree_copy_keys(cur, kp, &key, 1);
2205 xfs_btree_log_keys(cur, bp, ptr, ptr);
2206 }
2207
2208 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2209 return 0;
2210}
2211
2212/*
2213 * Update the record referred to by cur to the value in the
2214 * given record. This either works (return 0) or gets an
2215 * EFSCORRUPTED error.
2216 */
2217int
2218xfs_btree_update(
2219 struct xfs_btree_cur *cur,
2220 union xfs_btree_rec *rec)
2221{
2222 struct xfs_btree_block *block;
2223 struct xfs_buf *bp;
2224 int error;
2225 int ptr;
2226 union xfs_btree_rec *rp;
2227
2228 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2229 XFS_BTREE_TRACE_ARGR(cur, rec);
2230
2231 /* Pick up the current block. */
2232 block = xfs_btree_get_block(cur, 0, &bp);
2233
2234#ifdef DEBUG
2235 error = xfs_btree_check_block(cur, block, 0, bp);
2236 if (error)
2237 goto error0;
2238#endif
2239 /* Get the address of the rec to be updated. */
2240 ptr = cur->bc_ptrs[0];
2241 rp = xfs_btree_rec_addr(cur, ptr, block);
2242
2243 /* Fill in the new contents and log them. */
2244 xfs_btree_copy_recs(cur, rp, rec, 1);
2245 xfs_btree_log_recs(cur, bp, ptr, ptr);
2246
2247 /*
2248 * If we are tracking the last record in the tree and
2249 * we are at the far right edge of the tree, update it.
2250 */
2251 if (xfs_btree_is_lastrec(cur, block, 0)) {
2252 cur->bc_ops->update_lastrec(cur, block, rec,
2253 ptr, LASTREC_UPDATE);
2254 }
2255
2256 /* Pass new key value up to our parent. */
2257 if (xfs_btree_needs_key_update(cur, ptr)) {
2258 error = xfs_btree_update_keys(cur, 0);
2259 if (error)
2260 goto error0;
2261 }
2262
2263 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2264 return 0;
2265
2266error0:
2267 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2268 return error;
2269}
2270
2271/*
2272 * Move 1 record left from cur/level if possible.
2273 * Update cur to reflect the new path.
2274 */
2275STATIC int /* error */
2276xfs_btree_lshift(
2277 struct xfs_btree_cur *cur,
2278 int level,
2279 int *stat) /* success/failure */
2280{
2281 struct xfs_buf *lbp; /* left buffer pointer */
2282 struct xfs_btree_block *left; /* left btree block */
2283 int lrecs; /* left record count */
2284 struct xfs_buf *rbp; /* right buffer pointer */
2285 struct xfs_btree_block *right; /* right btree block */
2286 struct xfs_btree_cur *tcur; /* temporary btree cursor */
2287 int rrecs; /* right record count */
2288 union xfs_btree_ptr lptr; /* left btree pointer */
2289 union xfs_btree_key *rkp = NULL; /* right btree key */
2290 union xfs_btree_ptr *rpp = NULL; /* right address pointer */
2291 union xfs_btree_rec *rrp = NULL; /* right record pointer */
2292 int error; /* error return value */
2293 int i;
2294
2295 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2296 XFS_BTREE_TRACE_ARGI(cur, level);
2297
2298 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2299 level == cur->bc_nlevels - 1)
2300 goto out0;
2301
2302 /* Set up variables for this block as "right". */
2303 right = xfs_btree_get_block(cur, level, &rbp);
2304
2305#ifdef DEBUG
2306 error = xfs_btree_check_block(cur, right, level, rbp);
2307 if (error)
2308 goto error0;
2309#endif
2310
2311 /* If we've got no left sibling then we can't shift an entry left. */
2312 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2313 if (xfs_btree_ptr_is_null(cur, &lptr))
2314 goto out0;
2315
2316 /*
2317 * If the cursor entry is the one that would be moved, don't
2318 * do it... it's too complicated.
2319 */
2320 if (cur->bc_ptrs[level] <= 1)
2321 goto out0;
2322
2323 /* Set up the left neighbor as "left". */
2324 error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
2325 if (error)
2326 goto error0;
2327
2328 /* If it's full, it can't take another entry. */
2329 lrecs = xfs_btree_get_numrecs(left);
2330 if (lrecs == cur->bc_ops->get_maxrecs(cur, level))
2331 goto out0;
2332
2333 rrecs = xfs_btree_get_numrecs(right);
2334
2335 /*
2336 * We add one entry to the left side and remove one for the right side.
2337 * Account for it here, the changes will be updated on disk and logged
2338 * later.
2339 */
2340 lrecs++;
2341 rrecs--;
2342
2343 XFS_BTREE_STATS_INC(cur, lshift);
2344 XFS_BTREE_STATS_ADD(cur, moves, 1);
2345
2346 /*
2347 * If non-leaf, copy a key and a ptr to the left block.
2348 * Log the changes to the left block.
2349 */
2350 if (level > 0) {
2351 /* It's a non-leaf. Move keys and pointers. */
2352 union xfs_btree_key *lkp; /* left btree key */
2353 union xfs_btree_ptr *lpp; /* left address pointer */
2354
2355 lkp = xfs_btree_key_addr(cur, lrecs, left);
2356 rkp = xfs_btree_key_addr(cur, 1, right);
2357
2358 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2359 rpp = xfs_btree_ptr_addr(cur, 1, right);
2360#ifdef DEBUG
2361 error = xfs_btree_check_ptr(cur, rpp, 0, level);
2362 if (error)
2363 goto error0;
2364#endif
2365 xfs_btree_copy_keys(cur, lkp, rkp, 1);
2366 xfs_btree_copy_ptrs(cur, lpp, rpp, 1);
2367
2368 xfs_btree_log_keys(cur, lbp, lrecs, lrecs);
2369 xfs_btree_log_ptrs(cur, lbp, lrecs, lrecs);
2370
2371 ASSERT(cur->bc_ops->keys_inorder(cur,
2372 xfs_btree_key_addr(cur, lrecs - 1, left), lkp));
2373 } else {
2374 /* It's a leaf. Move records. */
2375 union xfs_btree_rec *lrp; /* left record pointer */
2376
2377 lrp = xfs_btree_rec_addr(cur, lrecs, left);
2378 rrp = xfs_btree_rec_addr(cur, 1, right);
2379
2380 xfs_btree_copy_recs(cur, lrp, rrp, 1);
2381 xfs_btree_log_recs(cur, lbp, lrecs, lrecs);
2382
2383 ASSERT(cur->bc_ops->recs_inorder(cur,
2384 xfs_btree_rec_addr(cur, lrecs - 1, left), lrp));
2385 }
2386
2387 xfs_btree_set_numrecs(left, lrecs);
2388 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2389
2390 xfs_btree_set_numrecs(right, rrecs);
2391 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2392
2393 /*
2394 * Slide the contents of right down one entry.
2395 */
2396 XFS_BTREE_STATS_ADD(cur, moves, rrecs - 1);
2397 if (level > 0) {
2398 /* It's a nonleaf. operate on keys and ptrs */
2399#ifdef DEBUG
2400 int i; /* loop index */
2401
2402 for (i = 0; i < rrecs; i++) {
2403 error = xfs_btree_check_ptr(cur, rpp, i + 1, level);
2404 if (error)
2405 goto error0;
2406 }
2407#endif
2408 xfs_btree_shift_keys(cur,
2409 xfs_btree_key_addr(cur, 2, right),
2410 -1, rrecs);
2411 xfs_btree_shift_ptrs(cur,
2412 xfs_btree_ptr_addr(cur, 2, right),
2413 -1, rrecs);
2414
2415 xfs_btree_log_keys(cur, rbp, 1, rrecs);
2416 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2417 } else {
2418 /* It's a leaf. operate on records */
2419 xfs_btree_shift_recs(cur,
2420 xfs_btree_rec_addr(cur, 2, right),
2421 -1, rrecs);
2422 xfs_btree_log_recs(cur, rbp, 1, rrecs);
2423 }
2424
2425 /*
2426 * Using a temporary cursor, update the parent key values of the
2427 * block on the left.
2428 */
2429 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2430 error = xfs_btree_dup_cursor(cur, &tcur);
2431 if (error)
2432 goto error0;
2433 i = xfs_btree_firstrec(tcur, level);
2434 XFS_WANT_CORRUPTED_GOTO(tcur->bc_mp, i == 1, error0);
2435
2436 error = xfs_btree_decrement(tcur, level, &i);
2437 if (error)
2438 goto error1;
2439
2440 /* Update the parent high keys of the left block, if needed. */
2441 error = xfs_btree_update_keys(tcur, level);
2442 if (error)
2443 goto error1;
2444
2445 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
2446 }
2447
2448 /* Update the parent keys of the right block. */
2449 error = xfs_btree_update_keys(cur, level);
2450 if (error)
2451 goto error0;
2452
2453 /* Slide the cursor value left one. */
2454 cur->bc_ptrs[level]--;
2455
2456 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2457 *stat = 1;
2458 return 0;
2459
2460out0:
2461 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2462 *stat = 0;
2463 return 0;
2464
2465error0:
2466 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2467 return error;
2468
2469error1:
2470 XFS_BTREE_TRACE_CURSOR(tcur, XBT_ERROR);
2471 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
2472 return error;
2473}
2474
2475/*
2476 * Move 1 record right from cur/level if possible.
2477 * Update cur to reflect the new path.
2478 */
2479STATIC int /* error */
2480xfs_btree_rshift(
2481 struct xfs_btree_cur *cur,
2482 int level,
2483 int *stat) /* success/failure */
2484{
2485 struct xfs_buf *lbp; /* left buffer pointer */
2486 struct xfs_btree_block *left; /* left btree block */
2487 struct xfs_buf *rbp; /* right buffer pointer */
2488 struct xfs_btree_block *right; /* right btree block */
2489 struct xfs_btree_cur *tcur; /* temporary btree cursor */
2490 union xfs_btree_ptr rptr; /* right block pointer */
2491 union xfs_btree_key *rkp; /* right btree key */
2492 int rrecs; /* right record count */
2493 int lrecs; /* left record count */
2494 int error; /* error return value */
2495 int i; /* loop counter */
2496
2497 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2498 XFS_BTREE_TRACE_ARGI(cur, level);
2499
2500 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2501 (level == cur->bc_nlevels - 1))
2502 goto out0;
2503
2504 /* Set up variables for this block as "left". */
2505 left = xfs_btree_get_block(cur, level, &lbp);
2506
2507#ifdef DEBUG
2508 error = xfs_btree_check_block(cur, left, level, lbp);
2509 if (error)
2510 goto error0;
2511#endif
2512
2513 /* If we've got no right sibling then we can't shift an entry right. */
2514 xfs_btree_get_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2515 if (xfs_btree_ptr_is_null(cur, &rptr))
2516 goto out0;
2517
2518 /*
2519 * If the cursor entry is the one that would be moved, don't
2520 * do it... it's too complicated.
2521 */
2522 lrecs = xfs_btree_get_numrecs(left);
2523 if (cur->bc_ptrs[level] >= lrecs)
2524 goto out0;
2525
2526 /* Set up the right neighbor as "right". */
2527 error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
2528 if (error)
2529 goto error0;
2530
2531 /* If it's full, it can't take another entry. */
2532 rrecs = xfs_btree_get_numrecs(right);
2533 if (rrecs == cur->bc_ops->get_maxrecs(cur, level))
2534 goto out0;
2535
2536 XFS_BTREE_STATS_INC(cur, rshift);
2537 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2538
2539 /*
2540 * Make a hole at the start of the right neighbor block, then
2541 * copy the last left block entry to the hole.
2542 */
2543 if (level > 0) {
2544 /* It's a nonleaf. make a hole in the keys and ptrs */
2545 union xfs_btree_key *lkp;
2546 union xfs_btree_ptr *lpp;
2547 union xfs_btree_ptr *rpp;
2548
2549 lkp = xfs_btree_key_addr(cur, lrecs, left);
2550 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2551 rkp = xfs_btree_key_addr(cur, 1, right);
2552 rpp = xfs_btree_ptr_addr(cur, 1, right);
2553
2554#ifdef DEBUG
2555 for (i = rrecs - 1; i >= 0; i--) {
2556 error = xfs_btree_check_ptr(cur, rpp, i, level);
2557 if (error)
2558 goto error0;
2559 }
2560#endif
2561
2562 xfs_btree_shift_keys(cur, rkp, 1, rrecs);
2563 xfs_btree_shift_ptrs(cur, rpp, 1, rrecs);
2564
2565#ifdef DEBUG
2566 error = xfs_btree_check_ptr(cur, lpp, 0, level);
2567 if (error)
2568 goto error0;
2569#endif
2570
2571 /* Now put the new data in, and log it. */
2572 xfs_btree_copy_keys(cur, rkp, lkp, 1);
2573 xfs_btree_copy_ptrs(cur, rpp, lpp, 1);
2574
2575 xfs_btree_log_keys(cur, rbp, 1, rrecs + 1);
2576 xfs_btree_log_ptrs(cur, rbp, 1, rrecs + 1);
2577
2578 ASSERT(cur->bc_ops->keys_inorder(cur, rkp,
2579 xfs_btree_key_addr(cur, 2, right)));
2580 } else {
2581 /* It's a leaf. make a hole in the records */
2582 union xfs_btree_rec *lrp;
2583 union xfs_btree_rec *rrp;
2584
2585 lrp = xfs_btree_rec_addr(cur, lrecs, left);
2586 rrp = xfs_btree_rec_addr(cur, 1, right);
2587
2588 xfs_btree_shift_recs(cur, rrp, 1, rrecs);
2589
2590 /* Now put the new data in, and log it. */
2591 xfs_btree_copy_recs(cur, rrp, lrp, 1);
2592 xfs_btree_log_recs(cur, rbp, 1, rrecs + 1);
2593 }
2594
2595 /*
2596 * Decrement and log left's numrecs, bump and log right's numrecs.
2597 */
2598 xfs_btree_set_numrecs(left, --lrecs);
2599 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2600
2601 xfs_btree_set_numrecs(right, ++rrecs);
2602 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2603
2604 /*
2605 * Using a temporary cursor, update the parent key values of the
2606 * block on the right.
2607 */
2608 error = xfs_btree_dup_cursor(cur, &tcur);
2609 if (error)
2610 goto error0;
2611 i = xfs_btree_lastrec(tcur, level);
2612 XFS_WANT_CORRUPTED_GOTO(tcur->bc_mp, i == 1, error0);
2613
2614 error = xfs_btree_increment(tcur, level, &i);
2615 if (error)
2616 goto error1;
2617
2618 /* Update the parent high keys of the left block, if needed. */
2619 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2620 error = xfs_btree_update_keys(cur, level);
2621 if (error)
2622 goto error1;
2623 }
2624
2625 /* Update the parent keys of the right block. */
2626 error = xfs_btree_update_keys(tcur, level);
2627 if (error)
2628 goto error1;
2629
2630 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
2631
2632 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2633 *stat = 1;
2634 return 0;
2635
2636out0:
2637 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2638 *stat = 0;
2639 return 0;
2640
2641error0:
2642 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2643 return error;
2644
2645error1:
2646 XFS_BTREE_TRACE_CURSOR(tcur, XBT_ERROR);
2647 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
2648 return error;
2649}
2650
2651/*
2652 * Split cur/level block in half.
2653 * Return new block number and the key to its first
2654 * record (to be inserted into parent).
2655 */
2656STATIC int /* error */
2657__xfs_btree_split(
2658 struct xfs_btree_cur *cur,
2659 int level,
2660 union xfs_btree_ptr *ptrp,
2661 union xfs_btree_key *key,
2662 struct xfs_btree_cur **curp,
2663 int *stat) /* success/failure */
2664{
2665 union xfs_btree_ptr lptr; /* left sibling block ptr */
2666 struct xfs_buf *lbp; /* left buffer pointer */
2667 struct xfs_btree_block *left; /* left btree block */
2668 union xfs_btree_ptr rptr; /* right sibling block ptr */
2669 struct xfs_buf *rbp; /* right buffer pointer */
2670 struct xfs_btree_block *right; /* right btree block */
2671 union xfs_btree_ptr rrptr; /* right-right sibling ptr */
2672 struct xfs_buf *rrbp; /* right-right buffer pointer */
2673 struct xfs_btree_block *rrblock; /* right-right btree block */
2674 int lrecs;
2675 int rrecs;
2676 int src_index;
2677 int error; /* error return value */
2678#ifdef DEBUG
2679 int i;
2680#endif
2681
2682 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2683 XFS_BTREE_TRACE_ARGIPK(cur, level, *ptrp, key);
2684
2685 XFS_BTREE_STATS_INC(cur, split);
2686
2687 /* Set up left block (current one). */
2688 left = xfs_btree_get_block(cur, level, &lbp);
2689
2690#ifdef DEBUG
2691 error = xfs_btree_check_block(cur, left, level, lbp);
2692 if (error)
2693 goto error0;
2694#endif
2695
2696 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2697
2698 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2699 error = cur->bc_ops->alloc_block(cur, &lptr, &rptr, stat);
2700 if (error)
2701 goto error0;
2702 if (*stat == 0)
2703 goto out0;
2704 XFS_BTREE_STATS_INC(cur, alloc);
2705
2706 /* Set up the new block as "right". */
2707 error = xfs_btree_get_buf_block(cur, &rptr, 0, &right, &rbp);
2708 if (error)
2709 goto error0;
2710
2711 /* Fill in the btree header for the new right block. */
2712 xfs_btree_init_block_cur(cur, rbp, xfs_btree_get_level(left), 0);
2713
2714 /*
2715 * Split the entries between the old and the new block evenly.
2716 * Make sure that if there's an odd number of entries now, that
2717 * each new block will have the same number of entries.
2718 */
2719 lrecs = xfs_btree_get_numrecs(left);
2720 rrecs = lrecs / 2;
2721 if ((lrecs & 1) && cur->bc_ptrs[level] <= rrecs + 1)
2722 rrecs++;
2723 src_index = (lrecs - rrecs + 1);
2724
2725 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2726
2727 /* Adjust numrecs for the later get_*_keys() calls. */
2728 lrecs -= rrecs;
2729 xfs_btree_set_numrecs(left, lrecs);
2730 xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs);
2731
2732 /*
2733 * Copy btree block entries from the left block over to the
2734 * new block, the right. Update the right block and log the
2735 * changes.
2736 */
2737 if (level > 0) {
2738 /* It's a non-leaf. Move keys and pointers. */
2739 union xfs_btree_key *lkp; /* left btree key */
2740 union xfs_btree_ptr *lpp; /* left address pointer */
2741 union xfs_btree_key *rkp; /* right btree key */
2742 union xfs_btree_ptr *rpp; /* right address pointer */
2743
2744 lkp = xfs_btree_key_addr(cur, src_index, left);
2745 lpp = xfs_btree_ptr_addr(cur, src_index, left);
2746 rkp = xfs_btree_key_addr(cur, 1, right);
2747 rpp = xfs_btree_ptr_addr(cur, 1, right);
2748
2749#ifdef DEBUG
2750 for (i = src_index; i < rrecs; i++) {
2751 error = xfs_btree_check_ptr(cur, lpp, i, level);
2752 if (error)
2753 goto error0;
2754 }
2755#endif
2756
2757 /* Copy the keys & pointers to the new block. */
2758 xfs_btree_copy_keys(cur, rkp, lkp, rrecs);
2759 xfs_btree_copy_ptrs(cur, rpp, lpp, rrecs);
2760
2761 xfs_btree_log_keys(cur, rbp, 1, rrecs);
2762 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2763
2764 /* Stash the keys of the new block for later insertion. */
2765 xfs_btree_get_node_keys(cur, right, key);
2766 } else {
2767 /* It's a leaf. Move records. */
2768 union xfs_btree_rec *lrp; /* left record pointer */
2769 union xfs_btree_rec *rrp; /* right record pointer */
2770
2771 lrp = xfs_btree_rec_addr(cur, src_index, left);
2772 rrp = xfs_btree_rec_addr(cur, 1, right);
2773
2774 /* Copy records to the new block. */
2775 xfs_btree_copy_recs(cur, rrp, lrp, rrecs);
2776 xfs_btree_log_recs(cur, rbp, 1, rrecs);
2777
2778 /* Stash the keys of the new block for later insertion. */
2779 xfs_btree_get_leaf_keys(cur, right, key);
2780 }
2781
2782 /*
2783 * Find the left block number by looking in the buffer.
2784 * Adjust sibling pointers.
2785 */
2786 xfs_btree_get_sibling(cur, left, &rrptr, XFS_BB_RIGHTSIB);
2787 xfs_btree_set_sibling(cur, right, &rrptr, XFS_BB_RIGHTSIB);
2788 xfs_btree_set_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2789 xfs_btree_set_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2790
2791 xfs_btree_log_block(cur, rbp, XFS_BB_ALL_BITS);
2792 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
2793
2794 /*
2795 * If there's a block to the new block's right, make that block
2796 * point back to right instead of to left.
2797 */
2798 if (!xfs_btree_ptr_is_null(cur, &rrptr)) {
2799 error = xfs_btree_read_buf_block(cur, &rrptr,
2800 0, &rrblock, &rrbp);
2801 if (error)
2802 goto error0;
2803 xfs_btree_set_sibling(cur, rrblock, &rptr, XFS_BB_LEFTSIB);
2804 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
2805 }
2806
2807 /* Update the parent high keys of the left block, if needed. */
2808 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2809 error = xfs_btree_update_keys(cur, level);
2810 if (error)
2811 goto error0;
2812 }
2813
2814 /*
2815 * If the cursor is really in the right block, move it there.
2816 * If it's just pointing past the last entry in left, then we'll
2817 * insert there, so don't change anything in that case.
2818 */
2819 if (cur->bc_ptrs[level] > lrecs + 1) {
2820 xfs_btree_setbuf(cur, level, rbp);
2821 cur->bc_ptrs[level] -= lrecs;
2822 }
2823 /*
2824 * If there are more levels, we'll need another cursor which refers
2825 * the right block, no matter where this cursor was.
2826 */
2827 if (level + 1 < cur->bc_nlevels) {
2828 error = xfs_btree_dup_cursor(cur, curp);
2829 if (error)
2830 goto error0;
2831 (*curp)->bc_ptrs[level + 1]++;
2832 }
2833 *ptrp = rptr;
2834 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2835 *stat = 1;
2836 return 0;
2837out0:
2838 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2839 *stat = 0;
2840 return 0;
2841
2842error0:
2843 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2844 return error;
2845}
2846
2847struct xfs_btree_split_args {
2848 struct xfs_btree_cur *cur;
2849 int level;
2850 union xfs_btree_ptr *ptrp;
2851 union xfs_btree_key *key;
2852 struct xfs_btree_cur **curp;
2853 int *stat; /* success/failure */
2854 int result;
2855 bool kswapd; /* allocation in kswapd context */
2856 struct completion *done;
2857 struct work_struct work;
2858};
2859
2860/*
2861 * Stack switching interfaces for allocation
2862 */
2863static void
2864xfs_btree_split_worker(
2865 struct work_struct *work)
2866{
2867 struct xfs_btree_split_args *args = container_of(work,
2868 struct xfs_btree_split_args, work);
2869 unsigned long pflags;
2870 unsigned long new_pflags = PF_FSTRANS;
2871
2872 /*
2873 * we are in a transaction context here, but may also be doing work
2874 * in kswapd context, and hence we may need to inherit that state
2875 * temporarily to ensure that we don't block waiting for memory reclaim
2876 * in any way.
2877 */
2878 if (args->kswapd)
2879 new_pflags |= PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD;
2880
2881 current_set_flags_nested(&pflags, new_pflags);
2882
2883 args->result = __xfs_btree_split(args->cur, args->level, args->ptrp,
2884 args->key, args->curp, args->stat);
2885 complete(args->done);
2886
2887 current_restore_flags_nested(&pflags, new_pflags);
2888}
2889
2890/*
2891 * BMBT split requests often come in with little stack to work on. Push
2892 * them off to a worker thread so there is lots of stack to use. For the other
2893 * btree types, just call directly to avoid the context switch overhead here.
2894 */
2895STATIC int /* error */
2896xfs_btree_split(
2897 struct xfs_btree_cur *cur,
2898 int level,
2899 union xfs_btree_ptr *ptrp,
2900 union xfs_btree_key *key,
2901 struct xfs_btree_cur **curp,
2902 int *stat) /* success/failure */
2903{
2904 struct xfs_btree_split_args args;
2905 DECLARE_COMPLETION_ONSTACK(done);
2906
2907 if (cur->bc_btnum != XFS_BTNUM_BMAP)
2908 return __xfs_btree_split(cur, level, ptrp, key, curp, stat);
2909
2910 args.cur = cur;
2911 args.level = level;
2912 args.ptrp = ptrp;
2913 args.key = key;
2914 args.curp = curp;
2915 args.stat = stat;
2916 args.done = &done;
2917 args.kswapd = current_is_kswapd();
2918 INIT_WORK_ONSTACK(&args.work, xfs_btree_split_worker);
2919 queue_work(xfs_alloc_wq, &args.work);
2920 wait_for_completion(&done);
2921 destroy_work_on_stack(&args.work);
2922 return args.result;
2923}
2924
2925
2926/*
2927 * Copy the old inode root contents into a real block and make the
2928 * broot point to it.
2929 */
2930int /* error */
2931xfs_btree_new_iroot(
2932 struct xfs_btree_cur *cur, /* btree cursor */
2933 int *logflags, /* logging flags for inode */
2934 int *stat) /* return status - 0 fail */
2935{
2936 struct xfs_buf *cbp; /* buffer for cblock */
2937 struct xfs_btree_block *block; /* btree block */
2938 struct xfs_btree_block *cblock; /* child btree block */
2939 union xfs_btree_key *ckp; /* child key pointer */
2940 union xfs_btree_ptr *cpp; /* child ptr pointer */
2941 union xfs_btree_key *kp; /* pointer to btree key */
2942 union xfs_btree_ptr *pp; /* pointer to block addr */
2943 union xfs_btree_ptr nptr; /* new block addr */
2944 int level; /* btree level */
2945 int error; /* error return code */
2946#ifdef DEBUG
2947 int i; /* loop counter */
2948#endif
2949
2950 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2951 XFS_BTREE_STATS_INC(cur, newroot);
2952
2953 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
2954
2955 level = cur->bc_nlevels - 1;
2956
2957 block = xfs_btree_get_iroot(cur);
2958 pp = xfs_btree_ptr_addr(cur, 1, block);
2959
2960 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2961 error = cur->bc_ops->alloc_block(cur, pp, &nptr, stat);
2962 if (error)
2963 goto error0;
2964 if (*stat == 0) {
2965 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2966 return 0;
2967 }
2968 XFS_BTREE_STATS_INC(cur, alloc);
2969
2970 /* Copy the root into a real block. */
2971 error = xfs_btree_get_buf_block(cur, &nptr, 0, &cblock, &cbp);
2972 if (error)
2973 goto error0;
2974
2975 /*
2976 * we can't just memcpy() the root in for CRC enabled btree blocks.
2977 * In that case have to also ensure the blkno remains correct
2978 */
2979 memcpy(cblock, block, xfs_btree_block_len(cur));
2980 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) {
2981 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
2982 cblock->bb_u.l.bb_blkno = cpu_to_be64(cbp->b_bn);
2983 else
2984 cblock->bb_u.s.bb_blkno = cpu_to_be64(cbp->b_bn);
2985 }
2986
2987 be16_add_cpu(&block->bb_level, 1);
2988 xfs_btree_set_numrecs(block, 1);
2989 cur->bc_nlevels++;
2990 cur->bc_ptrs[level + 1] = 1;
2991
2992 kp = xfs_btree_key_addr(cur, 1, block);
2993 ckp = xfs_btree_key_addr(cur, 1, cblock);
2994 xfs_btree_copy_keys(cur, ckp, kp, xfs_btree_get_numrecs(cblock));
2995
2996 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
2997#ifdef DEBUG
2998 for (i = 0; i < be16_to_cpu(cblock->bb_numrecs); i++) {
2999 error = xfs_btree_check_ptr(cur, pp, i, level);
3000 if (error)
3001 goto error0;
3002 }
3003#endif
3004 xfs_btree_copy_ptrs(cur, cpp, pp, xfs_btree_get_numrecs(cblock));
3005
3006#ifdef DEBUG
3007 error = xfs_btree_check_ptr(cur, &nptr, 0, level);
3008 if (error)
3009 goto error0;
3010#endif
3011 xfs_btree_copy_ptrs(cur, pp, &nptr, 1);
3012
3013 xfs_iroot_realloc(cur->bc_private.b.ip,
3014 1 - xfs_btree_get_numrecs(cblock),
3015 cur->bc_private.b.whichfork);
3016
3017 xfs_btree_setbuf(cur, level, cbp);
3018
3019 /*
3020 * Do all this logging at the end so that
3021 * the root is at the right level.
3022 */
3023 xfs_btree_log_block(cur, cbp, XFS_BB_ALL_BITS);
3024 xfs_btree_log_keys(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
3025 xfs_btree_log_ptrs(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
3026
3027 *logflags |=
3028 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork);
3029 *stat = 1;
3030 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3031 return 0;
3032error0:
3033 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3034 return error;
3035}
3036
3037/*
3038 * Allocate a new root block, fill it in.
3039 */
3040STATIC int /* error */
3041xfs_btree_new_root(
3042 struct xfs_btree_cur *cur, /* btree cursor */
3043 int *stat) /* success/failure */
3044{
3045 struct xfs_btree_block *block; /* one half of the old root block */
3046 struct xfs_buf *bp; /* buffer containing block */
3047 int error; /* error return value */
3048 struct xfs_buf *lbp; /* left buffer pointer */
3049 struct xfs_btree_block *left; /* left btree block */
3050 struct xfs_buf *nbp; /* new (root) buffer */
3051 struct xfs_btree_block *new; /* new (root) btree block */
3052 int nptr; /* new value for key index, 1 or 2 */
3053 struct xfs_buf *rbp; /* right buffer pointer */
3054 struct xfs_btree_block *right; /* right btree block */
3055 union xfs_btree_ptr rptr;
3056 union xfs_btree_ptr lptr;
3057
3058 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3059 XFS_BTREE_STATS_INC(cur, newroot);
3060
3061 /* initialise our start point from the cursor */
3062 cur->bc_ops->init_ptr_from_cur(cur, &rptr);
3063
3064 /* Allocate the new block. If we can't do it, we're toast. Give up. */
3065 error = cur->bc_ops->alloc_block(cur, &rptr, &lptr, stat);
3066 if (error)
3067 goto error0;
3068 if (*stat == 0)
3069 goto out0;
3070 XFS_BTREE_STATS_INC(cur, alloc);
3071
3072 /* Set up the new block. */
3073 error = xfs_btree_get_buf_block(cur, &lptr, 0, &new, &nbp);
3074 if (error)
3075 goto error0;
3076
3077 /* Set the root in the holding structure increasing the level by 1. */
3078 cur->bc_ops->set_root(cur, &lptr, 1);
3079
3080 /*
3081 * At the previous root level there are now two blocks: the old root,
3082 * and the new block generated when it was split. We don't know which
3083 * one the cursor is pointing at, so we set up variables "left" and
3084 * "right" for each case.
3085 */
3086 block = xfs_btree_get_block(cur, cur->bc_nlevels - 1, &bp);
3087
3088#ifdef DEBUG
3089 error = xfs_btree_check_block(cur, block, cur->bc_nlevels - 1, bp);
3090 if (error)
3091 goto error0;
3092#endif
3093
3094 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
3095 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
3096 /* Our block is left, pick up the right block. */
3097 lbp = bp;
3098 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
3099 left = block;
3100 error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
3101 if (error)
3102 goto error0;
3103 bp = rbp;
3104 nptr = 1;
3105 } else {
3106 /* Our block is right, pick up the left block. */
3107 rbp = bp;
3108 xfs_btree_buf_to_ptr(cur, rbp, &rptr);
3109 right = block;
3110 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
3111 error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
3112 if (error)
3113 goto error0;
3114 bp = lbp;
3115 nptr = 2;
3116 }
3117
3118 /* Fill in the new block's btree header and log it. */
3119 xfs_btree_init_block_cur(cur, nbp, cur->bc_nlevels, 2);
3120 xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS);
3121 ASSERT(!xfs_btree_ptr_is_null(cur, &lptr) &&
3122 !xfs_btree_ptr_is_null(cur, &rptr));
3123
3124 /* Fill in the key data in the new root. */
3125 if (xfs_btree_get_level(left) > 0) {
3126 /*
3127 * Get the keys for the left block's keys and put them directly
3128 * in the parent block. Do the same for the right block.
3129 */
3130 xfs_btree_get_node_keys(cur, left,
3131 xfs_btree_key_addr(cur, 1, new));
3132 xfs_btree_get_node_keys(cur, right,
3133 xfs_btree_key_addr(cur, 2, new));
3134 } else {
3135 /*
3136 * Get the keys for the left block's records and put them
3137 * directly in the parent block. Do the same for the right
3138 * block.
3139 */
3140 xfs_btree_get_leaf_keys(cur, left,
3141 xfs_btree_key_addr(cur, 1, new));
3142 xfs_btree_get_leaf_keys(cur, right,
3143 xfs_btree_key_addr(cur, 2, new));
3144 }
3145 xfs_btree_log_keys(cur, nbp, 1, 2);
3146
3147 /* Fill in the pointer data in the new root. */
3148 xfs_btree_copy_ptrs(cur,
3149 xfs_btree_ptr_addr(cur, 1, new), &lptr, 1);
3150 xfs_btree_copy_ptrs(cur,
3151 xfs_btree_ptr_addr(cur, 2, new), &rptr, 1);
3152 xfs_btree_log_ptrs(cur, nbp, 1, 2);
3153
3154 /* Fix up the cursor. */
3155 xfs_btree_setbuf(cur, cur->bc_nlevels, nbp);
3156 cur->bc_ptrs[cur->bc_nlevels] = nptr;
3157 cur->bc_nlevels++;
3158 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3159 *stat = 1;
3160 return 0;
3161error0:
3162 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3163 return error;
3164out0:
3165 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3166 *stat = 0;
3167 return 0;
3168}
3169
3170STATIC int
3171xfs_btree_make_block_unfull(
3172 struct xfs_btree_cur *cur, /* btree cursor */
3173 int level, /* btree level */
3174 int numrecs,/* # of recs in block */
3175 int *oindex,/* old tree index */
3176 int *index, /* new tree index */
3177 union xfs_btree_ptr *nptr, /* new btree ptr */
3178 struct xfs_btree_cur **ncur, /* new btree cursor */
3179 union xfs_btree_key *key, /* key of new block */
3180 int *stat)
3181{
3182 int error = 0;
3183
3184 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
3185 level == cur->bc_nlevels - 1) {
3186 struct xfs_inode *ip = cur->bc_private.b.ip;
3187
3188 if (numrecs < cur->bc_ops->get_dmaxrecs(cur, level)) {
3189 /* A root block that can be made bigger. */
3190 xfs_iroot_realloc(ip, 1, cur->bc_private.b.whichfork);
3191 *stat = 1;
3192 } else {
3193 /* A root block that needs replacing */
3194 int logflags = 0;
3195
3196 error = xfs_btree_new_iroot(cur, &logflags, stat);
3197 if (error || *stat == 0)
3198 return error;
3199
3200 xfs_trans_log_inode(cur->bc_tp, ip, logflags);
3201 }
3202
3203 return 0;
3204 }
3205
3206 /* First, try shifting an entry to the right neighbor. */
3207 error = xfs_btree_rshift(cur, level, stat);
3208 if (error || *stat)
3209 return error;
3210
3211 /* Next, try shifting an entry to the left neighbor. */
3212 error = xfs_btree_lshift(cur, level, stat);
3213 if (error)
3214 return error;
3215
3216 if (*stat) {
3217 *oindex = *index = cur->bc_ptrs[level];
3218 return 0;
3219 }
3220
3221 /*
3222 * Next, try splitting the current block in half.
3223 *
3224 * If this works we have to re-set our variables because we
3225 * could be in a different block now.
3226 */
3227 error = xfs_btree_split(cur, level, nptr, key, ncur, stat);
3228 if (error || *stat == 0)
3229 return error;
3230
3231
3232 *index = cur->bc_ptrs[level];
3233 return 0;
3234}
3235
3236/*
3237 * Insert one record/level. Return information to the caller
3238 * allowing the next level up to proceed if necessary.
3239 */
3240STATIC int
3241xfs_btree_insrec(
3242 struct xfs_btree_cur *cur, /* btree cursor */
3243 int level, /* level to insert record at */
3244 union xfs_btree_ptr *ptrp, /* i/o: block number inserted */
3245 union xfs_btree_rec *rec, /* record to insert */
3246 union xfs_btree_key *key, /* i/o: block key for ptrp */
3247 struct xfs_btree_cur **curp, /* output: new cursor replacing cur */
3248 int *stat) /* success/failure */
3249{
3250 struct xfs_btree_block *block; /* btree block */
3251 struct xfs_buf *bp; /* buffer for block */
3252 union xfs_btree_ptr nptr; /* new block ptr */
3253 struct xfs_btree_cur *ncur; /* new btree cursor */
3254 union xfs_btree_key nkey; /* new block key */
3255 union xfs_btree_key *lkey;
3256 int optr; /* old key/record index */
3257 int ptr; /* key/record index */
3258 int numrecs;/* number of records */
3259 int error; /* error return value */
3260#ifdef DEBUG
3261 int i;
3262#endif
3263 xfs_daddr_t old_bn;
3264
3265 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3266 XFS_BTREE_TRACE_ARGIPR(cur, level, *ptrp, &rec);
3267
3268 ncur = NULL;
3269 lkey = &nkey;
3270
3271 /*
3272 * If we have an external root pointer, and we've made it to the
3273 * root level, allocate a new root block and we're done.
3274 */
3275 if (!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
3276 (level >= cur->bc_nlevels)) {
3277 error = xfs_btree_new_root(cur, stat);
3278 xfs_btree_set_ptr_null(cur, ptrp);
3279
3280 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3281 return error;
3282 }
3283
3284 /* If we're off the left edge, return failure. */
3285 ptr = cur->bc_ptrs[level];
3286 if (ptr == 0) {
3287 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3288 *stat = 0;
3289 return 0;
3290 }
3291
3292 optr = ptr;
3293
3294 XFS_BTREE_STATS_INC(cur, insrec);
3295
3296 /* Get pointers to the btree buffer and block. */
3297 block = xfs_btree_get_block(cur, level, &bp);
3298 old_bn = bp ? bp->b_bn : XFS_BUF_DADDR_NULL;
3299 numrecs = xfs_btree_get_numrecs(block);
3300
3301#ifdef DEBUG
3302 error = xfs_btree_check_block(cur, block, level, bp);
3303 if (error)
3304 goto error0;
3305
3306 /* Check that the new entry is being inserted in the right place. */
3307 if (ptr <= numrecs) {
3308 if (level == 0) {
3309 ASSERT(cur->bc_ops->recs_inorder(cur, rec,
3310 xfs_btree_rec_addr(cur, ptr, block)));
3311 } else {
3312 ASSERT(cur->bc_ops->keys_inorder(cur, key,
3313 xfs_btree_key_addr(cur, ptr, block)));
3314 }
3315 }
3316#endif
3317
3318 /*
3319 * If the block is full, we can't insert the new entry until we
3320 * make the block un-full.
3321 */
3322 xfs_btree_set_ptr_null(cur, &nptr);
3323 if (numrecs == cur->bc_ops->get_maxrecs(cur, level)) {
3324 error = xfs_btree_make_block_unfull(cur, level, numrecs,
3325 &optr, &ptr, &nptr, &ncur, lkey, stat);
3326 if (error || *stat == 0)
3327 goto error0;
3328 }
3329
3330 /*
3331 * The current block may have changed if the block was
3332 * previously full and we have just made space in it.
3333 */
3334 block = xfs_btree_get_block(cur, level, &bp);
3335 numrecs = xfs_btree_get_numrecs(block);
3336
3337#ifdef DEBUG
3338 error = xfs_btree_check_block(cur, block, level, bp);
3339 if (error)
3340 return error;
3341#endif
3342
3343 /*
3344 * At this point we know there's room for our new entry in the block
3345 * we're pointing at.
3346 */
3347 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr + 1);
3348
3349 if (level > 0) {
3350 /* It's a nonleaf. make a hole in the keys and ptrs */
3351 union xfs_btree_key *kp;
3352 union xfs_btree_ptr *pp;
3353
3354 kp = xfs_btree_key_addr(cur, ptr, block);
3355 pp = xfs_btree_ptr_addr(cur, ptr, block);
3356
3357#ifdef DEBUG
3358 for (i = numrecs - ptr; i >= 0; i--) {
3359 error = xfs_btree_check_ptr(cur, pp, i, level);
3360 if (error)
3361 return error;
3362 }
3363#endif
3364
3365 xfs_btree_shift_keys(cur, kp, 1, numrecs - ptr + 1);
3366 xfs_btree_shift_ptrs(cur, pp, 1, numrecs - ptr + 1);
3367
3368#ifdef DEBUG
3369 error = xfs_btree_check_ptr(cur, ptrp, 0, level);
3370 if (error)
3371 goto error0;
3372#endif
3373
3374 /* Now put the new data in, bump numrecs and log it. */
3375 xfs_btree_copy_keys(cur, kp, key, 1);
3376 xfs_btree_copy_ptrs(cur, pp, ptrp, 1);
3377 numrecs++;
3378 xfs_btree_set_numrecs(block, numrecs);
3379 xfs_btree_log_ptrs(cur, bp, ptr, numrecs);
3380 xfs_btree_log_keys(cur, bp, ptr, numrecs);
3381#ifdef DEBUG
3382 if (ptr < numrecs) {
3383 ASSERT(cur->bc_ops->keys_inorder(cur, kp,
3384 xfs_btree_key_addr(cur, ptr + 1, block)));
3385 }
3386#endif
3387 } else {
3388 /* It's a leaf. make a hole in the records */
3389 union xfs_btree_rec *rp;
3390
3391 rp = xfs_btree_rec_addr(cur, ptr, block);
3392
3393 xfs_btree_shift_recs(cur, rp, 1, numrecs - ptr + 1);
3394
3395 /* Now put the new data in, bump numrecs and log it. */
3396 xfs_btree_copy_recs(cur, rp, rec, 1);
3397 xfs_btree_set_numrecs(block, ++numrecs);
3398 xfs_btree_log_recs(cur, bp, ptr, numrecs);
3399#ifdef DEBUG
3400 if (ptr < numrecs) {
3401 ASSERT(cur->bc_ops->recs_inorder(cur, rp,
3402 xfs_btree_rec_addr(cur, ptr + 1, block)));
3403 }
3404#endif
3405 }
3406
3407 /* Log the new number of records in the btree header. */
3408 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
3409
3410 /*
3411 * If we just inserted into a new tree block, we have to
3412 * recalculate nkey here because nkey is out of date.
3413 *
3414 * Otherwise we're just updating an existing block (having shoved
3415 * some records into the new tree block), so use the regular key
3416 * update mechanism.
3417 */
3418 if (bp && bp->b_bn != old_bn) {
3419 xfs_btree_get_keys(cur, block, lkey);
3420 } else if (xfs_btree_needs_key_update(cur, optr)) {
3421 error = xfs_btree_update_keys(cur, level);
3422 if (error)
3423 goto error0;
3424 }
3425
3426 /*
3427 * If we are tracking the last record in the tree and
3428 * we are at the far right edge of the tree, update it.
3429 */
3430 if (xfs_btree_is_lastrec(cur, block, level)) {
3431 cur->bc_ops->update_lastrec(cur, block, rec,
3432 ptr, LASTREC_INSREC);
3433 }
3434
3435 /*
3436 * Return the new block number, if any.
3437 * If there is one, give back a record value and a cursor too.
3438 */
3439 *ptrp = nptr;
3440 if (!xfs_btree_ptr_is_null(cur, &nptr)) {
3441 xfs_btree_copy_keys(cur, key, lkey, 1);
3442 *curp = ncur;
3443 }
3444
3445 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3446 *stat = 1;
3447 return 0;
3448
3449error0:
3450 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3451 return error;
3452}
3453
3454/*
3455 * Insert the record at the point referenced by cur.
3456 *
3457 * A multi-level split of the tree on insert will invalidate the original
3458 * cursor. All callers of this function should assume that the cursor is
3459 * no longer valid and revalidate it.
3460 */
3461int
3462xfs_btree_insert(
3463 struct xfs_btree_cur *cur,
3464 int *stat)
3465{
3466 int error; /* error return value */
3467 int i; /* result value, 0 for failure */
3468 int level; /* current level number in btree */
3469 union xfs_btree_ptr nptr; /* new block number (split result) */
3470 struct xfs_btree_cur *ncur; /* new cursor (split result) */
3471 struct xfs_btree_cur *pcur; /* previous level's cursor */
3472 union xfs_btree_key bkey; /* key of block to insert */
3473 union xfs_btree_key *key;
3474 union xfs_btree_rec rec; /* record to insert */
3475
3476 level = 0;
3477 ncur = NULL;
3478 pcur = cur;
3479 key = &bkey;
3480
3481 xfs_btree_set_ptr_null(cur, &nptr);
3482
3483 /* Make a key out of the record data to be inserted, and save it. */
3484 cur->bc_ops->init_rec_from_cur(cur, &rec);
3485 cur->bc_ops->init_key_from_rec(key, &rec);
3486
3487 /*
3488 * Loop going up the tree, starting at the leaf level.
3489 * Stop when we don't get a split block, that must mean that
3490 * the insert is finished with this level.
3491 */
3492 do {
3493 /*
3494 * Insert nrec/nptr into this level of the tree.
3495 * Note if we fail, nptr will be null.
3496 */
3497 error = xfs_btree_insrec(pcur, level, &nptr, &rec, key,
3498 &ncur, &i);
3499 if (error) {
3500 if (pcur != cur)
3501 xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR);
3502 goto error0;
3503 }
3504
3505 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
3506 level++;
3507
3508 /*
3509 * See if the cursor we just used is trash.
3510 * Can't trash the caller's cursor, but otherwise we should
3511 * if ncur is a new cursor or we're about to be done.
3512 */
3513 if (pcur != cur &&
3514 (ncur || xfs_btree_ptr_is_null(cur, &nptr))) {
3515 /* Save the state from the cursor before we trash it */
3516 if (cur->bc_ops->update_cursor)
3517 cur->bc_ops->update_cursor(pcur, cur);
3518 cur->bc_nlevels = pcur->bc_nlevels;
3519 xfs_btree_del_cursor(pcur, XFS_BTREE_NOERROR);
3520 }
3521 /* If we got a new cursor, switch to it. */
3522 if (ncur) {
3523 pcur = ncur;
3524 ncur = NULL;
3525 }
3526 } while (!xfs_btree_ptr_is_null(cur, &nptr));
3527
3528 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3529 *stat = i;
3530 return 0;
3531error0:
3532 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3533 return error;
3534}
3535
3536/*
3537 * Try to merge a non-leaf block back into the inode root.
3538 *
3539 * Note: the killroot names comes from the fact that we're effectively
3540 * killing the old root block. But because we can't just delete the
3541 * inode we have to copy the single block it was pointing to into the
3542 * inode.
3543 */
3544STATIC int
3545xfs_btree_kill_iroot(
3546 struct xfs_btree_cur *cur)
3547{
3548 int whichfork = cur->bc_private.b.whichfork;
3549 struct xfs_inode *ip = cur->bc_private.b.ip;
3550 struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork);
3551 struct xfs_btree_block *block;
3552 struct xfs_btree_block *cblock;
3553 union xfs_btree_key *kp;
3554 union xfs_btree_key *ckp;
3555 union xfs_btree_ptr *pp;
3556 union xfs_btree_ptr *cpp;
3557 struct xfs_buf *cbp;
3558 int level;
3559 int index;
3560 int numrecs;
3561 int error;
3562#ifdef DEBUG
3563 union xfs_btree_ptr ptr;
3564 int i;
3565#endif
3566
3567 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3568
3569 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
3570 ASSERT(cur->bc_nlevels > 1);
3571
3572 /*
3573 * Don't deal with the root block needs to be a leaf case.
3574 * We're just going to turn the thing back into extents anyway.
3575 */
3576 level = cur->bc_nlevels - 1;
3577 if (level == 1)
3578 goto out0;
3579
3580 /*
3581 * Give up if the root has multiple children.
3582 */
3583 block = xfs_btree_get_iroot(cur);
3584 if (xfs_btree_get_numrecs(block) != 1)
3585 goto out0;
3586
3587 cblock = xfs_btree_get_block(cur, level - 1, &cbp);
3588 numrecs = xfs_btree_get_numrecs(cblock);
3589
3590 /*
3591 * Only do this if the next level will fit.
3592 * Then the data must be copied up to the inode,
3593 * instead of freeing the root you free the next level.
3594 */
3595 if (numrecs > cur->bc_ops->get_dmaxrecs(cur, level))
3596 goto out0;
3597
3598 XFS_BTREE_STATS_INC(cur, killroot);
3599
3600#ifdef DEBUG
3601 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
3602 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
3603 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
3604 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
3605#endif
3606
3607 index = numrecs - cur->bc_ops->get_maxrecs(cur, level);
3608 if (index) {
3609 xfs_iroot_realloc(cur->bc_private.b.ip, index,
3610 cur->bc_private.b.whichfork);
3611 block = ifp->if_broot;
3612 }
3613
3614 be16_add_cpu(&block->bb_numrecs, index);
3615 ASSERT(block->bb_numrecs == cblock->bb_numrecs);
3616
3617 kp = xfs_btree_key_addr(cur, 1, block);
3618 ckp = xfs_btree_key_addr(cur, 1, cblock);
3619 xfs_btree_copy_keys(cur, kp, ckp, numrecs);
3620
3621 pp = xfs_btree_ptr_addr(cur, 1, block);
3622 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
3623#ifdef DEBUG
3624 for (i = 0; i < numrecs; i++) {
3625 error = xfs_btree_check_ptr(cur, cpp, i, level - 1);
3626 if (error) {
3627 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3628 return error;
3629 }
3630 }
3631#endif
3632 xfs_btree_copy_ptrs(cur, pp, cpp, numrecs);
3633
3634 error = xfs_btree_free_block(cur, cbp);
3635 if (error) {
3636 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3637 return error;
3638 }
3639
3640 cur->bc_bufs[level - 1] = NULL;
3641 be16_add_cpu(&block->bb_level, -1);
3642 xfs_trans_log_inode(cur->bc_tp, ip,
3643 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork));
3644 cur->bc_nlevels--;
3645out0:
3646 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3647 return 0;
3648}
3649
3650/*
3651 * Kill the current root node, and replace it with it's only child node.
3652 */
3653STATIC int
3654xfs_btree_kill_root(
3655 struct xfs_btree_cur *cur,
3656 struct xfs_buf *bp,
3657 int level,
3658 union xfs_btree_ptr *newroot)
3659{
3660 int error;
3661
3662 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3663 XFS_BTREE_STATS_INC(cur, killroot);
3664
3665 /*
3666 * Update the root pointer, decreasing the level by 1 and then
3667 * free the old root.
3668 */
3669 cur->bc_ops->set_root(cur, newroot, -1);
3670
3671 error = xfs_btree_free_block(cur, bp);
3672 if (error) {
3673 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3674 return error;
3675 }
3676
3677 cur->bc_bufs[level] = NULL;
3678 cur->bc_ra[level] = 0;
3679 cur->bc_nlevels--;
3680
3681 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3682 return 0;
3683}
3684
3685STATIC int
3686xfs_btree_dec_cursor(
3687 struct xfs_btree_cur *cur,
3688 int level,
3689 int *stat)
3690{
3691 int error;
3692 int i;
3693
3694 if (level > 0) {
3695 error = xfs_btree_decrement(cur, level, &i);
3696 if (error)
3697 return error;
3698 }
3699
3700 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3701 *stat = 1;
3702 return 0;
3703}
3704
3705/*
3706 * Single level of the btree record deletion routine.
3707 * Delete record pointed to by cur/level.
3708 * Remove the record from its block then rebalance the tree.
3709 * Return 0 for error, 1 for done, 2 to go on to the next level.
3710 */
3711STATIC int /* error */
3712xfs_btree_delrec(
3713 struct xfs_btree_cur *cur, /* btree cursor */
3714 int level, /* level removing record from */
3715 int *stat) /* fail/done/go-on */
3716{
3717 struct xfs_btree_block *block; /* btree block */
3718 union xfs_btree_ptr cptr; /* current block ptr */
3719 struct xfs_buf *bp; /* buffer for block */
3720 int error; /* error return value */
3721 int i; /* loop counter */
3722 union xfs_btree_ptr lptr; /* left sibling block ptr */
3723 struct xfs_buf *lbp; /* left buffer pointer */
3724 struct xfs_btree_block *left; /* left btree block */
3725 int lrecs = 0; /* left record count */
3726 int ptr; /* key/record index */
3727 union xfs_btree_ptr rptr; /* right sibling block ptr */
3728 struct xfs_buf *rbp; /* right buffer pointer */
3729 struct xfs_btree_block *right; /* right btree block */
3730 struct xfs_btree_block *rrblock; /* right-right btree block */
3731 struct xfs_buf *rrbp; /* right-right buffer pointer */
3732 int rrecs = 0; /* right record count */
3733 struct xfs_btree_cur *tcur; /* temporary btree cursor */
3734 int numrecs; /* temporary numrec count */
3735
3736 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3737 XFS_BTREE_TRACE_ARGI(cur, level);
3738
3739 tcur = NULL;
3740
3741 /* Get the index of the entry being deleted, check for nothing there. */
3742 ptr = cur->bc_ptrs[level];
3743 if (ptr == 0) {
3744 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3745 *stat = 0;
3746 return 0;
3747 }
3748
3749 /* Get the buffer & block containing the record or key/ptr. */
3750 block = xfs_btree_get_block(cur, level, &bp);
3751 numrecs = xfs_btree_get_numrecs(block);
3752
3753#ifdef DEBUG
3754 error = xfs_btree_check_block(cur, block, level, bp);
3755 if (error)
3756 goto error0;
3757#endif
3758
3759 /* Fail if we're off the end of the block. */
3760 if (ptr > numrecs) {
3761 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3762 *stat = 0;
3763 return 0;
3764 }
3765
3766 XFS_BTREE_STATS_INC(cur, delrec);
3767 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr);
3768
3769 /* Excise the entries being deleted. */
3770 if (level > 0) {
3771 /* It's a nonleaf. operate on keys and ptrs */
3772 union xfs_btree_key *lkp;
3773 union xfs_btree_ptr *lpp;
3774
3775 lkp = xfs_btree_key_addr(cur, ptr + 1, block);
3776 lpp = xfs_btree_ptr_addr(cur, ptr + 1, block);
3777
3778#ifdef DEBUG
3779 for (i = 0; i < numrecs - ptr; i++) {
3780 error = xfs_btree_check_ptr(cur, lpp, i, level);
3781 if (error)
3782 goto error0;
3783 }
3784#endif
3785
3786 if (ptr < numrecs) {
3787 xfs_btree_shift_keys(cur, lkp, -1, numrecs - ptr);
3788 xfs_btree_shift_ptrs(cur, lpp, -1, numrecs - ptr);
3789 xfs_btree_log_keys(cur, bp, ptr, numrecs - 1);
3790 xfs_btree_log_ptrs(cur, bp, ptr, numrecs - 1);
3791 }
3792 } else {
3793 /* It's a leaf. operate on records */
3794 if (ptr < numrecs) {
3795 xfs_btree_shift_recs(cur,
3796 xfs_btree_rec_addr(cur, ptr + 1, block),
3797 -1, numrecs - ptr);
3798 xfs_btree_log_recs(cur, bp, ptr, numrecs - 1);
3799 }
3800 }
3801
3802 /*
3803 * Decrement and log the number of entries in the block.
3804 */
3805 xfs_btree_set_numrecs(block, --numrecs);
3806 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
3807
3808 /*
3809 * If we are tracking the last record in the tree and
3810 * we are at the far right edge of the tree, update it.
3811 */
3812 if (xfs_btree_is_lastrec(cur, block, level)) {
3813 cur->bc_ops->update_lastrec(cur, block, NULL,
3814 ptr, LASTREC_DELREC);
3815 }
3816
3817 /*
3818 * We're at the root level. First, shrink the root block in-memory.
3819 * Try to get rid of the next level down. If we can't then there's
3820 * nothing left to do.
3821 */
3822 if (level == cur->bc_nlevels - 1) {
3823 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3824 xfs_iroot_realloc(cur->bc_private.b.ip, -1,
3825 cur->bc_private.b.whichfork);
3826
3827 error = xfs_btree_kill_iroot(cur);
3828 if (error)
3829 goto error0;
3830
3831 error = xfs_btree_dec_cursor(cur, level, stat);
3832 if (error)
3833 goto error0;
3834 *stat = 1;
3835 return 0;
3836 }
3837
3838 /*
3839 * If this is the root level, and there's only one entry left,
3840 * and it's NOT the leaf level, then we can get rid of this
3841 * level.
3842 */
3843 if (numrecs == 1 && level > 0) {
3844 union xfs_btree_ptr *pp;
3845 /*
3846 * pp is still set to the first pointer in the block.
3847 * Make it the new root of the btree.
3848 */
3849 pp = xfs_btree_ptr_addr(cur, 1, block);
3850 error = xfs_btree_kill_root(cur, bp, level, pp);
3851 if (error)
3852 goto error0;
3853 } else if (level > 0) {
3854 error = xfs_btree_dec_cursor(cur, level, stat);
3855 if (error)
3856 goto error0;
3857 }
3858 *stat = 1;
3859 return 0;
3860 }
3861
3862 /*
3863 * If we deleted the leftmost entry in the block, update the
3864 * key values above us in the tree.
3865 */
3866 if (xfs_btree_needs_key_update(cur, ptr)) {
3867 error = xfs_btree_update_keys(cur, level);
3868 if (error)
3869 goto error0;
3870 }
3871
3872 /*
3873 * If the number of records remaining in the block is at least
3874 * the minimum, we're done.
3875 */
3876 if (numrecs >= cur->bc_ops->get_minrecs(cur, level)) {
3877 error = xfs_btree_dec_cursor(cur, level, stat);
3878 if (error)
3879 goto error0;
3880 return 0;
3881 }
3882
3883 /*
3884 * Otherwise, we have to move some records around to keep the
3885 * tree balanced. Look at the left and right sibling blocks to
3886 * see if we can re-balance by moving only one record.
3887 */
3888 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
3889 xfs_btree_get_sibling(cur, block, &lptr, XFS_BB_LEFTSIB);
3890
3891 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3892 /*
3893 * One child of root, need to get a chance to copy its contents
3894 * into the root and delete it. Can't go up to next level,
3895 * there's nothing to delete there.
3896 */
3897 if (xfs_btree_ptr_is_null(cur, &rptr) &&
3898 xfs_btree_ptr_is_null(cur, &lptr) &&
3899 level == cur->bc_nlevels - 2) {
3900 error = xfs_btree_kill_iroot(cur);
3901 if (!error)
3902 error = xfs_btree_dec_cursor(cur, level, stat);
3903 if (error)
3904 goto error0;
3905 return 0;
3906 }
3907 }
3908
3909 ASSERT(!xfs_btree_ptr_is_null(cur, &rptr) ||
3910 !xfs_btree_ptr_is_null(cur, &lptr));
3911
3912 /*
3913 * Duplicate the cursor so our btree manipulations here won't
3914 * disrupt the next level up.
3915 */
3916 error = xfs_btree_dup_cursor(cur, &tcur);
3917 if (error)
3918 goto error0;
3919
3920 /*
3921 * If there's a right sibling, see if it's ok to shift an entry
3922 * out of it.
3923 */
3924 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
3925 /*
3926 * Move the temp cursor to the last entry in the next block.
3927 * Actually any entry but the first would suffice.
3928 */
3929 i = xfs_btree_lastrec(tcur, level);
3930 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
3931
3932 error = xfs_btree_increment(tcur, level, &i);
3933 if (error)
3934 goto error0;
3935 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
3936
3937 i = xfs_btree_lastrec(tcur, level);
3938 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
3939
3940 /* Grab a pointer to the block. */
3941 right = xfs_btree_get_block(tcur, level, &rbp);
3942#ifdef DEBUG
3943 error = xfs_btree_check_block(tcur, right, level, rbp);
3944 if (error)
3945 goto error0;
3946#endif
3947 /* Grab the current block number, for future use. */
3948 xfs_btree_get_sibling(tcur, right, &cptr, XFS_BB_LEFTSIB);
3949
3950 /*
3951 * If right block is full enough so that removing one entry
3952 * won't make it too empty, and left-shifting an entry out
3953 * of right to us works, we're done.
3954 */
3955 if (xfs_btree_get_numrecs(right) - 1 >=
3956 cur->bc_ops->get_minrecs(tcur, level)) {
3957 error = xfs_btree_lshift(tcur, level, &i);
3958 if (error)
3959 goto error0;
3960 if (i) {
3961 ASSERT(xfs_btree_get_numrecs(block) >=
3962 cur->bc_ops->get_minrecs(tcur, level));
3963
3964 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3965 tcur = NULL;
3966
3967 error = xfs_btree_dec_cursor(cur, level, stat);
3968 if (error)
3969 goto error0;
3970 return 0;
3971 }
3972 }
3973
3974 /*
3975 * Otherwise, grab the number of records in right for
3976 * future reference, and fix up the temp cursor to point
3977 * to our block again (last record).
3978 */
3979 rrecs = xfs_btree_get_numrecs(right);
3980 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3981 i = xfs_btree_firstrec(tcur, level);
3982 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
3983
3984 error = xfs_btree_decrement(tcur, level, &i);
3985 if (error)
3986 goto error0;
3987 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
3988 }
3989 }
3990
3991 /*
3992 * If there's a left sibling, see if it's ok to shift an entry
3993 * out of it.
3994 */
3995 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3996 /*
3997 * Move the temp cursor to the first entry in the
3998 * previous block.
3999 */
4000 i = xfs_btree_firstrec(tcur, level);
4001 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
4002
4003 error = xfs_btree_decrement(tcur, level, &i);
4004 if (error)
4005 goto error0;
4006 i = xfs_btree_firstrec(tcur, level);
4007 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
4008
4009 /* Grab a pointer to the block. */
4010 left = xfs_btree_get_block(tcur, level, &lbp);
4011#ifdef DEBUG
4012 error = xfs_btree_check_block(cur, left, level, lbp);
4013 if (error)
4014 goto error0;
4015#endif
4016 /* Grab the current block number, for future use. */
4017 xfs_btree_get_sibling(tcur, left, &cptr, XFS_BB_RIGHTSIB);
4018
4019 /*
4020 * If left block is full enough so that removing one entry
4021 * won't make it too empty, and right-shifting an entry out
4022 * of left to us works, we're done.
4023 */
4024 if (xfs_btree_get_numrecs(left) - 1 >=
4025 cur->bc_ops->get_minrecs(tcur, level)) {
4026 error = xfs_btree_rshift(tcur, level, &i);
4027 if (error)
4028 goto error0;
4029 if (i) {
4030 ASSERT(xfs_btree_get_numrecs(block) >=
4031 cur->bc_ops->get_minrecs(tcur, level));
4032 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
4033 tcur = NULL;
4034 if (level == 0)
4035 cur->bc_ptrs[0]++;
4036 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
4037 *stat = 1;
4038 return 0;
4039 }
4040 }
4041
4042 /*
4043 * Otherwise, grab the number of records in right for
4044 * future reference.
4045 */
4046 lrecs = xfs_btree_get_numrecs(left);
4047 }
4048
4049 /* Delete the temp cursor, we're done with it. */
4050 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
4051 tcur = NULL;
4052
4053 /* If here, we need to do a join to keep the tree balanced. */
4054 ASSERT(!xfs_btree_ptr_is_null(cur, &cptr));
4055
4056 if (!xfs_btree_ptr_is_null(cur, &lptr) &&
4057 lrecs + xfs_btree_get_numrecs(block) <=
4058 cur->bc_ops->get_maxrecs(cur, level)) {
4059 /*
4060 * Set "right" to be the starting block,
4061 * "left" to be the left neighbor.
4062 */
4063 rptr = cptr;
4064 right = block;
4065 rbp = bp;
4066 error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
4067 if (error)
4068 goto error0;
4069
4070 /*
4071 * If that won't work, see if we can join with the right neighbor block.
4072 */
4073 } else if (!xfs_btree_ptr_is_null(cur, &rptr) &&
4074 rrecs + xfs_btree_get_numrecs(block) <=
4075 cur->bc_ops->get_maxrecs(cur, level)) {
4076 /*
4077 * Set "left" to be the starting block,
4078 * "right" to be the right neighbor.
4079 */
4080 lptr = cptr;
4081 left = block;
4082 lbp = bp;
4083 error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
4084 if (error)
4085 goto error0;
4086
4087 /*
4088 * Otherwise, we can't fix the imbalance.
4089 * Just return. This is probably a logic error, but it's not fatal.
4090 */
4091 } else {
4092 error = xfs_btree_dec_cursor(cur, level, stat);
4093 if (error)
4094 goto error0;
4095 return 0;
4096 }
4097
4098 rrecs = xfs_btree_get_numrecs(right);
4099 lrecs = xfs_btree_get_numrecs(left);
4100
4101 /*
4102 * We're now going to join "left" and "right" by moving all the stuff
4103 * in "right" to "left" and deleting "right".
4104 */
4105 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
4106 if (level > 0) {
4107 /* It's a non-leaf. Move keys and pointers. */
4108 union xfs_btree_key *lkp; /* left btree key */
4109 union xfs_btree_ptr *lpp; /* left address pointer */
4110 union xfs_btree_key *rkp; /* right btree key */
4111 union xfs_btree_ptr *rpp; /* right address pointer */
4112
4113 lkp = xfs_btree_key_addr(cur, lrecs + 1, left);
4114 lpp = xfs_btree_ptr_addr(cur, lrecs + 1, left);
4115 rkp = xfs_btree_key_addr(cur, 1, right);
4116 rpp = xfs_btree_ptr_addr(cur, 1, right);
4117#ifdef DEBUG
4118 for (i = 1; i < rrecs; i++) {
4119 error = xfs_btree_check_ptr(cur, rpp, i, level);
4120 if (error)
4121 goto error0;
4122 }
4123#endif
4124 xfs_btree_copy_keys(cur, lkp, rkp, rrecs);
4125 xfs_btree_copy_ptrs(cur, lpp, rpp, rrecs);
4126
4127 xfs_btree_log_keys(cur, lbp, lrecs + 1, lrecs + rrecs);
4128 xfs_btree_log_ptrs(cur, lbp, lrecs + 1, lrecs + rrecs);
4129 } else {
4130 /* It's a leaf. Move records. */
4131 union xfs_btree_rec *lrp; /* left record pointer */
4132 union xfs_btree_rec *rrp; /* right record pointer */
4133
4134 lrp = xfs_btree_rec_addr(cur, lrecs + 1, left);
4135 rrp = xfs_btree_rec_addr(cur, 1, right);
4136
4137 xfs_btree_copy_recs(cur, lrp, rrp, rrecs);
4138 xfs_btree_log_recs(cur, lbp, lrecs + 1, lrecs + rrecs);
4139 }
4140
4141 XFS_BTREE_STATS_INC(cur, join);
4142
4143 /*
4144 * Fix up the number of records and right block pointer in the
4145 * surviving block, and log it.
4146 */
4147 xfs_btree_set_numrecs(left, lrecs + rrecs);
4148 xfs_btree_get_sibling(cur, right, &cptr, XFS_BB_RIGHTSIB),
4149 xfs_btree_set_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
4150 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
4151
4152 /* If there is a right sibling, point it to the remaining block. */
4153 xfs_btree_get_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
4154 if (!xfs_btree_ptr_is_null(cur, &cptr)) {
4155 error = xfs_btree_read_buf_block(cur, &cptr, 0, &rrblock, &rrbp);
4156 if (error)
4157 goto error0;
4158 xfs_btree_set_sibling(cur, rrblock, &lptr, XFS_BB_LEFTSIB);
4159 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
4160 }
4161
4162 /* Free the deleted block. */
4163 error = xfs_btree_free_block(cur, rbp);
4164 if (error)
4165 goto error0;
4166
4167 /*
4168 * If we joined with the left neighbor, set the buffer in the
4169 * cursor to the left block, and fix up the index.
4170 */
4171 if (bp != lbp) {
4172 cur->bc_bufs[level] = lbp;
4173 cur->bc_ptrs[level] += lrecs;
4174 cur->bc_ra[level] = 0;
4175 }
4176 /*
4177 * If we joined with the right neighbor and there's a level above
4178 * us, increment the cursor at that level.
4179 */
4180 else if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) ||
4181 (level + 1 < cur->bc_nlevels)) {
4182 error = xfs_btree_increment(cur, level + 1, &i);
4183 if (error)
4184 goto error0;
4185 }
4186
4187 /*
4188 * Readjust the ptr at this level if it's not a leaf, since it's
4189 * still pointing at the deletion point, which makes the cursor
4190 * inconsistent. If this makes the ptr 0, the caller fixes it up.
4191 * We can't use decrement because it would change the next level up.
4192 */
4193 if (level > 0)
4194 cur->bc_ptrs[level]--;
4195
4196 /*
4197 * We combined blocks, so we have to update the parent keys if the
4198 * btree supports overlapped intervals. However, bc_ptrs[level + 1]
4199 * points to the old block so that the caller knows which record to
4200 * delete. Therefore, the caller must be savvy enough to call updkeys
4201 * for us if we return stat == 2. The other exit points from this
4202 * function don't require deletions further up the tree, so they can
4203 * call updkeys directly.
4204 */
4205
4206 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
4207 /* Return value means the next level up has something to do. */
4208 *stat = 2;
4209 return 0;
4210
4211error0:
4212 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
4213 if (tcur)
4214 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
4215 return error;
4216}
4217
4218/*
4219 * Delete the record pointed to by cur.
4220 * The cursor refers to the place where the record was (could be inserted)
4221 * when the operation returns.
4222 */
4223int /* error */
4224xfs_btree_delete(
4225 struct xfs_btree_cur *cur,
4226 int *stat) /* success/failure */
4227{
4228 int error; /* error return value */
4229 int level;
4230 int i;
4231 bool joined = false;
4232
4233 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
4234
4235 /*
4236 * Go up the tree, starting at leaf level.
4237 *
4238 * If 2 is returned then a join was done; go to the next level.
4239 * Otherwise we are done.
4240 */
4241 for (level = 0, i = 2; i == 2; level++) {
4242 error = xfs_btree_delrec(cur, level, &i);
4243 if (error)
4244 goto error0;
4245 if (i == 2)
4246 joined = true;
4247 }
4248
4249 /*
4250 * If we combined blocks as part of deleting the record, delrec won't
4251 * have updated the parent high keys so we have to do that here.
4252 */
4253 if (joined && (cur->bc_flags & XFS_BTREE_OVERLAPPING)) {
4254 error = xfs_btree_updkeys_force(cur, 0);
4255 if (error)
4256 goto error0;
4257 }
4258
4259 if (i == 0) {
4260 for (level = 1; level < cur->bc_nlevels; level++) {
4261 if (cur->bc_ptrs[level] == 0) {
4262 error = xfs_btree_decrement(cur, level, &i);
4263 if (error)
4264 goto error0;
4265 break;
4266 }
4267 }
4268 }
4269
4270 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
4271 *stat = i;
4272 return 0;
4273error0:
4274 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
4275 return error;
4276}
4277
4278/*
4279 * Get the data from the pointed-to record.
4280 */
4281int /* error */
4282xfs_btree_get_rec(
4283 struct xfs_btree_cur *cur, /* btree cursor */
4284 union xfs_btree_rec **recp, /* output: btree record */
4285 int *stat) /* output: success/failure */
4286{
4287 struct xfs_btree_block *block; /* btree block */
4288 struct xfs_buf *bp; /* buffer pointer */
4289 int ptr; /* record number */
4290#ifdef DEBUG
4291 int error; /* error return value */
4292#endif
4293
4294 ptr = cur->bc_ptrs[0];
4295 block = xfs_btree_get_block(cur, 0, &bp);
4296
4297#ifdef DEBUG
4298 error = xfs_btree_check_block(cur, block, 0, bp);
4299 if (error)
4300 return error;
4301#endif
4302
4303 /*
4304 * Off the right end or left end, return failure.
4305 */
4306 if (ptr > xfs_btree_get_numrecs(block) || ptr <= 0) {
4307 *stat = 0;
4308 return 0;
4309 }
4310
4311 /*
4312 * Point to the record and extract its data.
4313 */
4314 *recp = xfs_btree_rec_addr(cur, ptr, block);
4315 *stat = 1;
4316 return 0;
4317}
4318
4319/* Visit a block in a btree. */
4320STATIC int
4321xfs_btree_visit_block(
4322 struct xfs_btree_cur *cur,
4323 int level,
4324 xfs_btree_visit_blocks_fn fn,
4325 void *data)
4326{
4327 struct xfs_btree_block *block;
4328 struct xfs_buf *bp;
4329 union xfs_btree_ptr rptr;
4330 int error;
4331
4332 /* do right sibling readahead */
4333 xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
4334 block = xfs_btree_get_block(cur, level, &bp);
4335
4336 /* process the block */
4337 error = fn(cur, level, data);
4338 if (error)
4339 return error;
4340
4341 /* now read rh sibling block for next iteration */
4342 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
4343 if (xfs_btree_ptr_is_null(cur, &rptr))
4344 return -ENOENT;
4345
4346 return xfs_btree_lookup_get_block(cur, level, &rptr, &block);
4347}
4348
4349
4350/* Visit every block in a btree. */
4351int
4352xfs_btree_visit_blocks(
4353 struct xfs_btree_cur *cur,
4354 xfs_btree_visit_blocks_fn fn,
4355 void *data)
4356{
4357 union xfs_btree_ptr lptr;
4358 int level;
4359 struct xfs_btree_block *block = NULL;
4360 int error = 0;
4361
4362 cur->bc_ops->init_ptr_from_cur(cur, &lptr);
4363
4364 /* for each level */
4365 for (level = cur->bc_nlevels - 1; level >= 0; level--) {
4366 /* grab the left hand block */
4367 error = xfs_btree_lookup_get_block(cur, level, &lptr, &block);
4368 if (error)
4369 return error;
4370
4371 /* readahead the left most block for the next level down */
4372 if (level > 0) {
4373 union xfs_btree_ptr *ptr;
4374
4375 ptr = xfs_btree_ptr_addr(cur, 1, block);
4376 xfs_btree_readahead_ptr(cur, ptr, 1);
4377
4378 /* save for the next iteration of the loop */
4379 lptr = *ptr;
4380 }
4381
4382 /* for each buffer in the level */
4383 do {
4384 error = xfs_btree_visit_block(cur, level, fn, data);
4385 } while (!error);
4386
4387 if (error != -ENOENT)
4388 return error;
4389 }
4390
4391 return 0;
4392}
4393
4394/*
4395 * Change the owner of a btree.
4396 *
4397 * The mechanism we use here is ordered buffer logging. Because we don't know
4398 * how many buffers were are going to need to modify, we don't really want to
4399 * have to make transaction reservations for the worst case of every buffer in a
4400 * full size btree as that may be more space that we can fit in the log....
4401 *
4402 * We do the btree walk in the most optimal manner possible - we have sibling
4403 * pointers so we can just walk all the blocks on each level from left to right
4404 * in a single pass, and then move to the next level and do the same. We can
4405 * also do readahead on the sibling pointers to get IO moving more quickly,
4406 * though for slow disks this is unlikely to make much difference to performance
4407 * as the amount of CPU work we have to do before moving to the next block is
4408 * relatively small.
4409 *
4410 * For each btree block that we load, modify the owner appropriately, set the
4411 * buffer as an ordered buffer and log it appropriately. We need to ensure that
4412 * we mark the region we change dirty so that if the buffer is relogged in
4413 * a subsequent transaction the changes we make here as an ordered buffer are
4414 * correctly relogged in that transaction. If we are in recovery context, then
4415 * just queue the modified buffer as delayed write buffer so the transaction
4416 * recovery completion writes the changes to disk.
4417 */
4418struct xfs_btree_block_change_owner_info {
4419 __uint64_t new_owner;
4420 struct list_head *buffer_list;
4421};
4422
4423static int
4424xfs_btree_block_change_owner(
4425 struct xfs_btree_cur *cur,
4426 int level,
4427 void *data)
4428{
4429 struct xfs_btree_block_change_owner_info *bbcoi = data;
4430 struct xfs_btree_block *block;
4431 struct xfs_buf *bp;
4432
4433 /* modify the owner */
4434 block = xfs_btree_get_block(cur, level, &bp);
4435 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
4436 block->bb_u.l.bb_owner = cpu_to_be64(bbcoi->new_owner);
4437 else
4438 block->bb_u.s.bb_owner = cpu_to_be32(bbcoi->new_owner);
4439
4440 /*
4441 * If the block is a root block hosted in an inode, we might not have a
4442 * buffer pointer here and we shouldn't attempt to log the change as the
4443 * information is already held in the inode and discarded when the root
4444 * block is formatted into the on-disk inode fork. We still change it,
4445 * though, so everything is consistent in memory.
4446 */
4447 if (bp) {
4448 if (cur->bc_tp) {
4449 xfs_trans_ordered_buf(cur->bc_tp, bp);
4450 xfs_btree_log_block(cur, bp, XFS_BB_OWNER);
4451 } else {
4452 xfs_buf_delwri_queue(bp, bbcoi->buffer_list);
4453 }
4454 } else {
4455 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
4456 ASSERT(level == cur->bc_nlevels - 1);
4457 }
4458
4459 return 0;
4460}
4461
4462int
4463xfs_btree_change_owner(
4464 struct xfs_btree_cur *cur,
4465 __uint64_t new_owner,
4466 struct list_head *buffer_list)
4467{
4468 struct xfs_btree_block_change_owner_info bbcoi;
4469
4470 bbcoi.new_owner = new_owner;
4471 bbcoi.buffer_list = buffer_list;
4472
4473 return xfs_btree_visit_blocks(cur, xfs_btree_block_change_owner,
4474 &bbcoi);
4475}
4476
4477/**
4478 * xfs_btree_sblock_v5hdr_verify() -- verify the v5 fields of a short-format
4479 * btree block
4480 *
4481 * @bp: buffer containing the btree block
4482 * @max_recs: pointer to the m_*_mxr max records field in the xfs mount
4483 * @pag_max_level: pointer to the per-ag max level field
4484 */
4485bool
4486xfs_btree_sblock_v5hdr_verify(
4487 struct xfs_buf *bp)
4488{
4489 struct xfs_mount *mp = bp->b_target->bt_mount;
4490 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
4491 struct xfs_perag *pag = bp->b_pag;
4492
4493 if (!xfs_sb_version_hascrc(&mp->m_sb))
4494 return false;
4495 if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid))
4496 return false;
4497 if (block->bb_u.s.bb_blkno != cpu_to_be64(bp->b_bn))
4498 return false;
4499 if (pag && be32_to_cpu(block->bb_u.s.bb_owner) != pag->pag_agno)
4500 return false;
4501 return true;
4502}
4503
4504/**
4505 * xfs_btree_sblock_verify() -- verify a short-format btree block
4506 *
4507 * @bp: buffer containing the btree block
4508 * @max_recs: maximum records allowed in this btree node
4509 */
4510bool
4511xfs_btree_sblock_verify(
4512 struct xfs_buf *bp,
4513 unsigned int max_recs)
4514{
4515 struct xfs_mount *mp = bp->b_target->bt_mount;
4516 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
4517
4518 /* numrecs verification */
4519 if (be16_to_cpu(block->bb_numrecs) > max_recs)
4520 return false;
4521
4522 /* sibling pointer verification */
4523 if (!block->bb_u.s.bb_leftsib ||
4524 (be32_to_cpu(block->bb_u.s.bb_leftsib) >= mp->m_sb.sb_agblocks &&
4525 block->bb_u.s.bb_leftsib != cpu_to_be32(NULLAGBLOCK)))
4526 return false;
4527 if (!block->bb_u.s.bb_rightsib ||
4528 (be32_to_cpu(block->bb_u.s.bb_rightsib) >= mp->m_sb.sb_agblocks &&
4529 block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK)))
4530 return false;
4531
4532 return true;
4533}
4534
4535/*
4536 * Calculate the number of btree levels needed to store a given number of
4537 * records in a short-format btree.
4538 */
4539uint
4540xfs_btree_compute_maxlevels(
4541 struct xfs_mount *mp,
4542 uint *limits,
4543 unsigned long len)
4544{
4545 uint level;
4546 unsigned long maxblocks;
4547
4548 maxblocks = (len + limits[0] - 1) / limits[0];
4549 for (level = 1; maxblocks > 1; level++)
4550 maxblocks = (maxblocks + limits[1] - 1) / limits[1];
4551 return level;
4552}
4553
4554/*
4555 * Query a regular btree for all records overlapping a given interval.
4556 * Start with a LE lookup of the key of low_rec and return all records
4557 * until we find a record with a key greater than the key of high_rec.
4558 */
4559STATIC int
4560xfs_btree_simple_query_range(
4561 struct xfs_btree_cur *cur,
4562 union xfs_btree_key *low_key,
4563 union xfs_btree_key *high_key,
4564 xfs_btree_query_range_fn fn,
4565 void *priv)
4566{
4567 union xfs_btree_rec *recp;
4568 union xfs_btree_key rec_key;
4569 __int64_t diff;
4570 int stat;
4571 bool firstrec = true;
4572 int error;
4573
4574 ASSERT(cur->bc_ops->init_high_key_from_rec);
4575 ASSERT(cur->bc_ops->diff_two_keys);
4576
4577 /*
4578 * Find the leftmost record. The btree cursor must be set
4579 * to the low record used to generate low_key.
4580 */
4581 stat = 0;
4582 error = xfs_btree_lookup(cur, XFS_LOOKUP_LE, &stat);
4583 if (error)
4584 goto out;
4585
4586 /* Nothing? See if there's anything to the right. */
4587 if (!stat) {
4588 error = xfs_btree_increment(cur, 0, &stat);
4589 if (error)
4590 goto out;
4591 }
4592
4593 while (stat) {
4594 /* Find the record. */
4595 error = xfs_btree_get_rec(cur, &recp, &stat);
4596 if (error || !stat)
4597 break;
4598
4599 /* Skip if high_key(rec) < low_key. */
4600 if (firstrec) {
4601 cur->bc_ops->init_high_key_from_rec(&rec_key, recp);
4602 firstrec = false;
4603 diff = cur->bc_ops->diff_two_keys(cur, low_key,
4604 &rec_key);
4605 if (diff > 0)
4606 goto advloop;
4607 }
4608
4609 /* Stop if high_key < low_key(rec). */
4610 cur->bc_ops->init_key_from_rec(&rec_key, recp);
4611 diff = cur->bc_ops->diff_two_keys(cur, &rec_key, high_key);
4612 if (diff > 0)
4613 break;
4614
4615 /* Callback */
4616 error = fn(cur, recp, priv);
4617 if (error < 0 || error == XFS_BTREE_QUERY_RANGE_ABORT)
4618 break;
4619
4620advloop:
4621 /* Move on to the next record. */
4622 error = xfs_btree_increment(cur, 0, &stat);
4623 if (error)
4624 break;
4625 }
4626
4627out:
4628 return error;
4629}
4630
4631/*
4632 * Query an overlapped interval btree for all records overlapping a given
4633 * interval. This function roughly follows the algorithm given in
4634 * "Interval Trees" of _Introduction to Algorithms_, which is section
4635 * 14.3 in the 2nd and 3rd editions.
4636 *
4637 * First, generate keys for the low and high records passed in.
4638 *
4639 * For any leaf node, generate the high and low keys for the record.
4640 * If the record keys overlap with the query low/high keys, pass the
4641 * record to the function iterator.
4642 *
4643 * For any internal node, compare the low and high keys of each
4644 * pointer against the query low/high keys. If there's an overlap,
4645 * follow the pointer.
4646 *
4647 * As an optimization, we stop scanning a block when we find a low key
4648 * that is greater than the query's high key.
4649 */
4650STATIC int
4651xfs_btree_overlapped_query_range(
4652 struct xfs_btree_cur *cur,
4653 union xfs_btree_key *low_key,
4654 union xfs_btree_key *high_key,
4655 xfs_btree_query_range_fn fn,
4656 void *priv)
4657{
4658 union xfs_btree_ptr ptr;
4659 union xfs_btree_ptr *pp;
4660 union xfs_btree_key rec_key;
4661 union xfs_btree_key rec_hkey;
4662 union xfs_btree_key *lkp;
4663 union xfs_btree_key *hkp;
4664 union xfs_btree_rec *recp;
4665 struct xfs_btree_block *block;
4666 __int64_t ldiff;
4667 __int64_t hdiff;
4668 int level;
4669 struct xfs_buf *bp;
4670 int i;
4671 int error;
4672
4673 /* Load the root of the btree. */
4674 level = cur->bc_nlevels - 1;
4675 cur->bc_ops->init_ptr_from_cur(cur, &ptr);
4676 error = xfs_btree_lookup_get_block(cur, level, &ptr, &block);
4677 if (error)
4678 return error;
4679 xfs_btree_get_block(cur, level, &bp);
4680 trace_xfs_btree_overlapped_query_range(cur, level, bp);
4681#ifdef DEBUG
4682 error = xfs_btree_check_block(cur, block, level, bp);
4683 if (error)
4684 goto out;
4685#endif
4686 cur->bc_ptrs[level] = 1;
4687
4688 while (level < cur->bc_nlevels) {
4689 block = xfs_btree_get_block(cur, level, &bp);
4690
4691 /* End of node, pop back towards the root. */
4692 if (cur->bc_ptrs[level] > be16_to_cpu(block->bb_numrecs)) {
4693pop_up:
4694 if (level < cur->bc_nlevels - 1)
4695 cur->bc_ptrs[level + 1]++;
4696 level++;
4697 continue;
4698 }
4699
4700 if (level == 0) {
4701 /* Handle a leaf node. */
4702 recp = xfs_btree_rec_addr(cur, cur->bc_ptrs[0], block);
4703
4704 cur->bc_ops->init_high_key_from_rec(&rec_hkey, recp);
4705 ldiff = cur->bc_ops->diff_two_keys(cur, &rec_hkey,
4706 low_key);
4707
4708 cur->bc_ops->init_key_from_rec(&rec_key, recp);
4709 hdiff = cur->bc_ops->diff_two_keys(cur, high_key,
4710 &rec_key);
4711
4712 /*
4713 * If (record's high key >= query's low key) and
4714 * (query's high key >= record's low key), then
4715 * this record overlaps the query range; callback.
4716 */
4717 if (ldiff >= 0 && hdiff >= 0) {
4718 error = fn(cur, recp, priv);
4719 if (error < 0 ||
4720 error == XFS_BTREE_QUERY_RANGE_ABORT)
4721 break;
4722 } else if (hdiff < 0) {
4723 /* Record is larger than high key; pop. */
4724 goto pop_up;
4725 }
4726 cur->bc_ptrs[level]++;
4727 continue;
4728 }
4729
4730 /* Handle an internal node. */
4731 lkp = xfs_btree_key_addr(cur, cur->bc_ptrs[level], block);
4732 hkp = xfs_btree_high_key_addr(cur, cur->bc_ptrs[level], block);
4733 pp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[level], block);
4734
4735 ldiff = cur->bc_ops->diff_two_keys(cur, hkp, low_key);
4736 hdiff = cur->bc_ops->diff_two_keys(cur, high_key, lkp);
4737
4738 /*
4739 * If (pointer's high key >= query's low key) and
4740 * (query's high key >= pointer's low key), then
4741 * this record overlaps the query range; follow pointer.
4742 */
4743 if (ldiff >= 0 && hdiff >= 0) {
4744 level--;
4745 error = xfs_btree_lookup_get_block(cur, level, pp,
4746 &block);
4747 if (error)
4748 goto out;
4749 xfs_btree_get_block(cur, level, &bp);
4750 trace_xfs_btree_overlapped_query_range(cur, level, bp);
4751#ifdef DEBUG
4752 error = xfs_btree_check_block(cur, block, level, bp);
4753 if (error)
4754 goto out;
4755#endif
4756 cur->bc_ptrs[level] = 1;
4757 continue;
4758 } else if (hdiff < 0) {
4759 /* The low key is larger than the upper range; pop. */
4760 goto pop_up;
4761 }
4762 cur->bc_ptrs[level]++;
4763 }
4764
4765out:
4766 /*
4767 * If we don't end this function with the cursor pointing at a record
4768 * block, a subsequent non-error cursor deletion will not release
4769 * node-level buffers, causing a buffer leak. This is quite possible
4770 * with a zero-results range query, so release the buffers if we
4771 * failed to return any results.
4772 */
4773 if (cur->bc_bufs[0] == NULL) {
4774 for (i = 0; i < cur->bc_nlevels; i++) {
4775 if (cur->bc_bufs[i]) {
4776 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[i]);
4777 cur->bc_bufs[i] = NULL;
4778 cur->bc_ptrs[i] = 0;
4779 cur->bc_ra[i] = 0;
4780 }
4781 }
4782 }
4783
4784 return error;
4785}
4786
4787/*
4788 * Query a btree for all records overlapping a given interval of keys. The
4789 * supplied function will be called with each record found; return one of the
4790 * XFS_BTREE_QUERY_RANGE_{CONTINUE,ABORT} values or the usual negative error
4791 * code. This function returns XFS_BTREE_QUERY_RANGE_ABORT, zero, or a
4792 * negative error code.
4793 */
4794int
4795xfs_btree_query_range(
4796 struct xfs_btree_cur *cur,
4797 union xfs_btree_irec *low_rec,
4798 union xfs_btree_irec *high_rec,
4799 xfs_btree_query_range_fn fn,
4800 void *priv)
4801{
4802 union xfs_btree_rec rec;
4803 union xfs_btree_key low_key;
4804 union xfs_btree_key high_key;
4805
4806 /* Find the keys of both ends of the interval. */
4807 cur->bc_rec = *high_rec;
4808 cur->bc_ops->init_rec_from_cur(cur, &rec);
4809 cur->bc_ops->init_key_from_rec(&high_key, &rec);
4810
4811 cur->bc_rec = *low_rec;
4812 cur->bc_ops->init_rec_from_cur(cur, &rec);
4813 cur->bc_ops->init_key_from_rec(&low_key, &rec);
4814
4815 /* Enforce low key < high key. */
4816 if (cur->bc_ops->diff_two_keys(cur, &low_key, &high_key) > 0)
4817 return -EINVAL;
4818
4819 if (!(cur->bc_flags & XFS_BTREE_OVERLAPPING))
4820 return xfs_btree_simple_query_range(cur, &low_key,
4821 &high_key, fn, priv);
4822 return xfs_btree_overlapped_query_range(cur, &low_key, &high_key,
4823 fn, priv);
4824}
4825
4826/*
4827 * Calculate the number of blocks needed to store a given number of records
4828 * in a short-format (per-AG metadata) btree.
4829 */
4830xfs_extlen_t
4831xfs_btree_calc_size(
4832 struct xfs_mount *mp,
4833 uint *limits,
4834 unsigned long long len)
4835{
4836 int level;
4837 int maxrecs;
4838 xfs_extlen_t rval;
4839
4840 maxrecs = limits[0];
4841 for (level = 0, rval = 0; len > 1; level++) {
4842 len += maxrecs - 1;
4843 do_div(len, maxrecs);
4844 maxrecs = limits[1];
4845 rval += len;
4846 }
4847 return rval;
4848}
4849
4850static int
4851xfs_btree_count_blocks_helper(
4852 struct xfs_btree_cur *cur,
4853 int level,
4854 void *data)
4855{
4856 xfs_extlen_t *blocks = data;
4857 (*blocks)++;
4858
4859 return 0;
4860}
4861
4862/* Count the blocks in a btree and return the result in *blocks. */
4863int
4864xfs_btree_count_blocks(
4865 struct xfs_btree_cur *cur,
4866 xfs_extlen_t *blocks)
4867{
4868 *blocks = 0;
4869 return xfs_btree_visit_blocks(cur, xfs_btree_count_blocks_helper,
4870 blocks);
4871}