Loading...
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_inode.h"
27#include "xfs_trans.h"
28#include "xfs_inode_item.h"
29#include "xfs_buf_item.h"
30#include "xfs_btree.h"
31#include "xfs_error.h"
32#include "xfs_trace.h"
33#include "xfs_cksum.h"
34#include "xfs_alloc.h"
35#include "xfs_log.h"
36
37/*
38 * Cursor allocation zone.
39 */
40kmem_zone_t *xfs_btree_cur_zone;
41
42/*
43 * Btree magic numbers.
44 */
45static const __uint32_t xfs_magics[2][XFS_BTNUM_MAX] = {
46 { XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, XFS_BMAP_MAGIC, XFS_IBT_MAGIC,
47 XFS_FIBT_MAGIC },
48 { XFS_ABTB_CRC_MAGIC, XFS_ABTC_CRC_MAGIC,
49 XFS_BMAP_CRC_MAGIC, XFS_IBT_CRC_MAGIC, XFS_FIBT_CRC_MAGIC }
50};
51#define xfs_btree_magic(cur) \
52 xfs_magics[!!((cur)->bc_flags & XFS_BTREE_CRC_BLOCKS)][cur->bc_btnum]
53
54
55STATIC int /* error (0 or EFSCORRUPTED) */
56xfs_btree_check_lblock(
57 struct xfs_btree_cur *cur, /* btree cursor */
58 struct xfs_btree_block *block, /* btree long form block pointer */
59 int level, /* level of the btree block */
60 struct xfs_buf *bp) /* buffer for block, if any */
61{
62 int lblock_ok = 1; /* block passes checks */
63 struct xfs_mount *mp; /* file system mount point */
64
65 mp = cur->bc_mp;
66
67 if (xfs_sb_version_hascrc(&mp->m_sb)) {
68 lblock_ok = lblock_ok &&
69 uuid_equal(&block->bb_u.l.bb_uuid,
70 &mp->m_sb.sb_meta_uuid) &&
71 block->bb_u.l.bb_blkno == cpu_to_be64(
72 bp ? bp->b_bn : XFS_BUF_DADDR_NULL);
73 }
74
75 lblock_ok = lblock_ok &&
76 be32_to_cpu(block->bb_magic) == xfs_btree_magic(cur) &&
77 be16_to_cpu(block->bb_level) == level &&
78 be16_to_cpu(block->bb_numrecs) <=
79 cur->bc_ops->get_maxrecs(cur, level) &&
80 block->bb_u.l.bb_leftsib &&
81 (block->bb_u.l.bb_leftsib == cpu_to_be64(NULLFSBLOCK) ||
82 XFS_FSB_SANITY_CHECK(mp,
83 be64_to_cpu(block->bb_u.l.bb_leftsib))) &&
84 block->bb_u.l.bb_rightsib &&
85 (block->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK) ||
86 XFS_FSB_SANITY_CHECK(mp,
87 be64_to_cpu(block->bb_u.l.bb_rightsib)));
88
89 if (unlikely(XFS_TEST_ERROR(!lblock_ok, mp,
90 XFS_ERRTAG_BTREE_CHECK_LBLOCK,
91 XFS_RANDOM_BTREE_CHECK_LBLOCK))) {
92 if (bp)
93 trace_xfs_btree_corrupt(bp, _RET_IP_);
94 XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
95 return -EFSCORRUPTED;
96 }
97 return 0;
98}
99
100STATIC int /* error (0 or EFSCORRUPTED) */
101xfs_btree_check_sblock(
102 struct xfs_btree_cur *cur, /* btree cursor */
103 struct xfs_btree_block *block, /* btree short form block pointer */
104 int level, /* level of the btree block */
105 struct xfs_buf *bp) /* buffer containing block */
106{
107 struct xfs_mount *mp; /* file system mount point */
108 struct xfs_buf *agbp; /* buffer for ag. freespace struct */
109 struct xfs_agf *agf; /* ag. freespace structure */
110 xfs_agblock_t agflen; /* native ag. freespace length */
111 int sblock_ok = 1; /* block passes checks */
112
113 mp = cur->bc_mp;
114 agbp = cur->bc_private.a.agbp;
115 agf = XFS_BUF_TO_AGF(agbp);
116 agflen = be32_to_cpu(agf->agf_length);
117
118 if (xfs_sb_version_hascrc(&mp->m_sb)) {
119 sblock_ok = sblock_ok &&
120 uuid_equal(&block->bb_u.s.bb_uuid,
121 &mp->m_sb.sb_meta_uuid) &&
122 block->bb_u.s.bb_blkno == cpu_to_be64(
123 bp ? bp->b_bn : XFS_BUF_DADDR_NULL);
124 }
125
126 sblock_ok = sblock_ok &&
127 be32_to_cpu(block->bb_magic) == xfs_btree_magic(cur) &&
128 be16_to_cpu(block->bb_level) == level &&
129 be16_to_cpu(block->bb_numrecs) <=
130 cur->bc_ops->get_maxrecs(cur, level) &&
131 (block->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK) ||
132 be32_to_cpu(block->bb_u.s.bb_leftsib) < agflen) &&
133 block->bb_u.s.bb_leftsib &&
134 (block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK) ||
135 be32_to_cpu(block->bb_u.s.bb_rightsib) < agflen) &&
136 block->bb_u.s.bb_rightsib;
137
138 if (unlikely(XFS_TEST_ERROR(!sblock_ok, mp,
139 XFS_ERRTAG_BTREE_CHECK_SBLOCK,
140 XFS_RANDOM_BTREE_CHECK_SBLOCK))) {
141 if (bp)
142 trace_xfs_btree_corrupt(bp, _RET_IP_);
143 XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
144 return -EFSCORRUPTED;
145 }
146 return 0;
147}
148
149/*
150 * Debug routine: check that block header is ok.
151 */
152int
153xfs_btree_check_block(
154 struct xfs_btree_cur *cur, /* btree cursor */
155 struct xfs_btree_block *block, /* generic btree block pointer */
156 int level, /* level of the btree block */
157 struct xfs_buf *bp) /* buffer containing block, if any */
158{
159 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
160 return xfs_btree_check_lblock(cur, block, level, bp);
161 else
162 return xfs_btree_check_sblock(cur, block, level, bp);
163}
164
165/*
166 * Check that (long) pointer is ok.
167 */
168int /* error (0 or EFSCORRUPTED) */
169xfs_btree_check_lptr(
170 struct xfs_btree_cur *cur, /* btree cursor */
171 xfs_fsblock_t bno, /* btree block disk address */
172 int level) /* btree block level */
173{
174 XFS_WANT_CORRUPTED_RETURN(cur->bc_mp,
175 level > 0 &&
176 bno != NULLFSBLOCK &&
177 XFS_FSB_SANITY_CHECK(cur->bc_mp, bno));
178 return 0;
179}
180
181#ifdef DEBUG
182/*
183 * Check that (short) pointer is ok.
184 */
185STATIC int /* error (0 or EFSCORRUPTED) */
186xfs_btree_check_sptr(
187 struct xfs_btree_cur *cur, /* btree cursor */
188 xfs_agblock_t bno, /* btree block disk address */
189 int level) /* btree block level */
190{
191 xfs_agblock_t agblocks = cur->bc_mp->m_sb.sb_agblocks;
192
193 XFS_WANT_CORRUPTED_RETURN(cur->bc_mp,
194 level > 0 &&
195 bno != NULLAGBLOCK &&
196 bno != 0 &&
197 bno < agblocks);
198 return 0;
199}
200
201/*
202 * Check that block ptr is ok.
203 */
204STATIC int /* error (0 or EFSCORRUPTED) */
205xfs_btree_check_ptr(
206 struct xfs_btree_cur *cur, /* btree cursor */
207 union xfs_btree_ptr *ptr, /* btree block disk address */
208 int index, /* offset from ptr to check */
209 int level) /* btree block level */
210{
211 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
212 return xfs_btree_check_lptr(cur,
213 be64_to_cpu((&ptr->l)[index]), level);
214 } else {
215 return xfs_btree_check_sptr(cur,
216 be32_to_cpu((&ptr->s)[index]), level);
217 }
218}
219#endif
220
221/*
222 * Calculate CRC on the whole btree block and stuff it into the
223 * long-form btree header.
224 *
225 * Prior to calculting the CRC, pull the LSN out of the buffer log item and put
226 * it into the buffer so recovery knows what the last modification was that made
227 * it to disk.
228 */
229void
230xfs_btree_lblock_calc_crc(
231 struct xfs_buf *bp)
232{
233 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
234 struct xfs_buf_log_item *bip = bp->b_fspriv;
235
236 if (!xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb))
237 return;
238 if (bip)
239 block->bb_u.l.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
240 xfs_buf_update_cksum(bp, XFS_BTREE_LBLOCK_CRC_OFF);
241}
242
243bool
244xfs_btree_lblock_verify_crc(
245 struct xfs_buf *bp)
246{
247 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
248 struct xfs_mount *mp = bp->b_target->bt_mount;
249
250 if (xfs_sb_version_hascrc(&mp->m_sb)) {
251 if (!xfs_log_check_lsn(mp, be64_to_cpu(block->bb_u.l.bb_lsn)))
252 return false;
253 return xfs_buf_verify_cksum(bp, XFS_BTREE_LBLOCK_CRC_OFF);
254 }
255
256 return true;
257}
258
259/*
260 * Calculate CRC on the whole btree block and stuff it into the
261 * short-form btree header.
262 *
263 * Prior to calculting the CRC, pull the LSN out of the buffer log item and put
264 * it into the buffer so recovery knows what the last modification was that made
265 * it to disk.
266 */
267void
268xfs_btree_sblock_calc_crc(
269 struct xfs_buf *bp)
270{
271 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
272 struct xfs_buf_log_item *bip = bp->b_fspriv;
273
274 if (!xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb))
275 return;
276 if (bip)
277 block->bb_u.s.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
278 xfs_buf_update_cksum(bp, XFS_BTREE_SBLOCK_CRC_OFF);
279}
280
281bool
282xfs_btree_sblock_verify_crc(
283 struct xfs_buf *bp)
284{
285 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
286 struct xfs_mount *mp = bp->b_target->bt_mount;
287
288 if (xfs_sb_version_hascrc(&mp->m_sb)) {
289 if (!xfs_log_check_lsn(mp, be64_to_cpu(block->bb_u.s.bb_lsn)))
290 return false;
291 return xfs_buf_verify_cksum(bp, XFS_BTREE_SBLOCK_CRC_OFF);
292 }
293
294 return true;
295}
296
297static int
298xfs_btree_free_block(
299 struct xfs_btree_cur *cur,
300 struct xfs_buf *bp)
301{
302 int error;
303
304 error = cur->bc_ops->free_block(cur, bp);
305 if (!error) {
306 xfs_trans_binval(cur->bc_tp, bp);
307 XFS_BTREE_STATS_INC(cur, free);
308 }
309 return error;
310}
311
312/*
313 * Delete the btree cursor.
314 */
315void
316xfs_btree_del_cursor(
317 xfs_btree_cur_t *cur, /* btree cursor */
318 int error) /* del because of error */
319{
320 int i; /* btree level */
321
322 /*
323 * Clear the buffer pointers, and release the buffers.
324 * If we're doing this in the face of an error, we
325 * need to make sure to inspect all of the entries
326 * in the bc_bufs array for buffers to be unlocked.
327 * This is because some of the btree code works from
328 * level n down to 0, and if we get an error along
329 * the way we won't have initialized all the entries
330 * down to 0.
331 */
332 for (i = 0; i < cur->bc_nlevels; i++) {
333 if (cur->bc_bufs[i])
334 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[i]);
335 else if (!error)
336 break;
337 }
338 /*
339 * Can't free a bmap cursor without having dealt with the
340 * allocated indirect blocks' accounting.
341 */
342 ASSERT(cur->bc_btnum != XFS_BTNUM_BMAP ||
343 cur->bc_private.b.allocated == 0);
344 /*
345 * Free the cursor.
346 */
347 kmem_zone_free(xfs_btree_cur_zone, cur);
348}
349
350/*
351 * Duplicate the btree cursor.
352 * Allocate a new one, copy the record, re-get the buffers.
353 */
354int /* error */
355xfs_btree_dup_cursor(
356 xfs_btree_cur_t *cur, /* input cursor */
357 xfs_btree_cur_t **ncur) /* output cursor */
358{
359 xfs_buf_t *bp; /* btree block's buffer pointer */
360 int error; /* error return value */
361 int i; /* level number of btree block */
362 xfs_mount_t *mp; /* mount structure for filesystem */
363 xfs_btree_cur_t *new; /* new cursor value */
364 xfs_trans_t *tp; /* transaction pointer, can be NULL */
365
366 tp = cur->bc_tp;
367 mp = cur->bc_mp;
368
369 /*
370 * Allocate a new cursor like the old one.
371 */
372 new = cur->bc_ops->dup_cursor(cur);
373
374 /*
375 * Copy the record currently in the cursor.
376 */
377 new->bc_rec = cur->bc_rec;
378
379 /*
380 * For each level current, re-get the buffer and copy the ptr value.
381 */
382 for (i = 0; i < new->bc_nlevels; i++) {
383 new->bc_ptrs[i] = cur->bc_ptrs[i];
384 new->bc_ra[i] = cur->bc_ra[i];
385 bp = cur->bc_bufs[i];
386 if (bp) {
387 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
388 XFS_BUF_ADDR(bp), mp->m_bsize,
389 0, &bp,
390 cur->bc_ops->buf_ops);
391 if (error) {
392 xfs_btree_del_cursor(new, error);
393 *ncur = NULL;
394 return error;
395 }
396 }
397 new->bc_bufs[i] = bp;
398 }
399 *ncur = new;
400 return 0;
401}
402
403/*
404 * XFS btree block layout and addressing:
405 *
406 * There are two types of blocks in the btree: leaf and non-leaf blocks.
407 *
408 * The leaf record start with a header then followed by records containing
409 * the values. A non-leaf block also starts with the same header, and
410 * then first contains lookup keys followed by an equal number of pointers
411 * to the btree blocks at the previous level.
412 *
413 * +--------+-------+-------+-------+-------+-------+-------+
414 * Leaf: | header | rec 1 | rec 2 | rec 3 | rec 4 | rec 5 | rec N |
415 * +--------+-------+-------+-------+-------+-------+-------+
416 *
417 * +--------+-------+-------+-------+-------+-------+-------+
418 * Non-Leaf: | header | key 1 | key 2 | key N | ptr 1 | ptr 2 | ptr N |
419 * +--------+-------+-------+-------+-------+-------+-------+
420 *
421 * The header is called struct xfs_btree_block for reasons better left unknown
422 * and comes in different versions for short (32bit) and long (64bit) block
423 * pointers. The record and key structures are defined by the btree instances
424 * and opaque to the btree core. The block pointers are simple disk endian
425 * integers, available in a short (32bit) and long (64bit) variant.
426 *
427 * The helpers below calculate the offset of a given record, key or pointer
428 * into a btree block (xfs_btree_*_offset) or return a pointer to the given
429 * record, key or pointer (xfs_btree_*_addr). Note that all addressing
430 * inside the btree block is done using indices starting at one, not zero!
431 */
432
433/*
434 * Return size of the btree block header for this btree instance.
435 */
436static inline size_t xfs_btree_block_len(struct xfs_btree_cur *cur)
437{
438 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
439 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
440 return XFS_BTREE_LBLOCK_CRC_LEN;
441 return XFS_BTREE_LBLOCK_LEN;
442 }
443 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
444 return XFS_BTREE_SBLOCK_CRC_LEN;
445 return XFS_BTREE_SBLOCK_LEN;
446}
447
448/*
449 * Return size of btree block pointers for this btree instance.
450 */
451static inline size_t xfs_btree_ptr_len(struct xfs_btree_cur *cur)
452{
453 return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
454 sizeof(__be64) : sizeof(__be32);
455}
456
457/*
458 * Calculate offset of the n-th record in a btree block.
459 */
460STATIC size_t
461xfs_btree_rec_offset(
462 struct xfs_btree_cur *cur,
463 int n)
464{
465 return xfs_btree_block_len(cur) +
466 (n - 1) * cur->bc_ops->rec_len;
467}
468
469/*
470 * Calculate offset of the n-th key in a btree block.
471 */
472STATIC size_t
473xfs_btree_key_offset(
474 struct xfs_btree_cur *cur,
475 int n)
476{
477 return xfs_btree_block_len(cur) +
478 (n - 1) * cur->bc_ops->key_len;
479}
480
481/*
482 * Calculate offset of the n-th block pointer in a btree block.
483 */
484STATIC size_t
485xfs_btree_ptr_offset(
486 struct xfs_btree_cur *cur,
487 int n,
488 int level)
489{
490 return xfs_btree_block_len(cur) +
491 cur->bc_ops->get_maxrecs(cur, level) * cur->bc_ops->key_len +
492 (n - 1) * xfs_btree_ptr_len(cur);
493}
494
495/*
496 * Return a pointer to the n-th record in the btree block.
497 */
498STATIC union xfs_btree_rec *
499xfs_btree_rec_addr(
500 struct xfs_btree_cur *cur,
501 int n,
502 struct xfs_btree_block *block)
503{
504 return (union xfs_btree_rec *)
505 ((char *)block + xfs_btree_rec_offset(cur, n));
506}
507
508/*
509 * Return a pointer to the n-th key in the btree block.
510 */
511STATIC union xfs_btree_key *
512xfs_btree_key_addr(
513 struct xfs_btree_cur *cur,
514 int n,
515 struct xfs_btree_block *block)
516{
517 return (union xfs_btree_key *)
518 ((char *)block + xfs_btree_key_offset(cur, n));
519}
520
521/*
522 * Return a pointer to the n-th block pointer in the btree block.
523 */
524STATIC union xfs_btree_ptr *
525xfs_btree_ptr_addr(
526 struct xfs_btree_cur *cur,
527 int n,
528 struct xfs_btree_block *block)
529{
530 int level = xfs_btree_get_level(block);
531
532 ASSERT(block->bb_level != 0);
533
534 return (union xfs_btree_ptr *)
535 ((char *)block + xfs_btree_ptr_offset(cur, n, level));
536}
537
538/*
539 * Get the root block which is stored in the inode.
540 *
541 * For now this btree implementation assumes the btree root is always
542 * stored in the if_broot field of an inode fork.
543 */
544STATIC struct xfs_btree_block *
545xfs_btree_get_iroot(
546 struct xfs_btree_cur *cur)
547{
548 struct xfs_ifork *ifp;
549
550 ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, cur->bc_private.b.whichfork);
551 return (struct xfs_btree_block *)ifp->if_broot;
552}
553
554/*
555 * Retrieve the block pointer from the cursor at the given level.
556 * This may be an inode btree root or from a buffer.
557 */
558STATIC struct xfs_btree_block * /* generic btree block pointer */
559xfs_btree_get_block(
560 struct xfs_btree_cur *cur, /* btree cursor */
561 int level, /* level in btree */
562 struct xfs_buf **bpp) /* buffer containing the block */
563{
564 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
565 (level == cur->bc_nlevels - 1)) {
566 *bpp = NULL;
567 return xfs_btree_get_iroot(cur);
568 }
569
570 *bpp = cur->bc_bufs[level];
571 return XFS_BUF_TO_BLOCK(*bpp);
572}
573
574/*
575 * Get a buffer for the block, return it with no data read.
576 * Long-form addressing.
577 */
578xfs_buf_t * /* buffer for fsbno */
579xfs_btree_get_bufl(
580 xfs_mount_t *mp, /* file system mount point */
581 xfs_trans_t *tp, /* transaction pointer */
582 xfs_fsblock_t fsbno, /* file system block number */
583 uint lock) /* lock flags for get_buf */
584{
585 xfs_daddr_t d; /* real disk block address */
586
587 ASSERT(fsbno != NULLFSBLOCK);
588 d = XFS_FSB_TO_DADDR(mp, fsbno);
589 return xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
590}
591
592/*
593 * Get a buffer for the block, return it with no data read.
594 * Short-form addressing.
595 */
596xfs_buf_t * /* buffer for agno/agbno */
597xfs_btree_get_bufs(
598 xfs_mount_t *mp, /* file system mount point */
599 xfs_trans_t *tp, /* transaction pointer */
600 xfs_agnumber_t agno, /* allocation group number */
601 xfs_agblock_t agbno, /* allocation group block number */
602 uint lock) /* lock flags for get_buf */
603{
604 xfs_daddr_t d; /* real disk block address */
605
606 ASSERT(agno != NULLAGNUMBER);
607 ASSERT(agbno != NULLAGBLOCK);
608 d = XFS_AGB_TO_DADDR(mp, agno, agbno);
609 return xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
610}
611
612/*
613 * Check for the cursor referring to the last block at the given level.
614 */
615int /* 1=is last block, 0=not last block */
616xfs_btree_islastblock(
617 xfs_btree_cur_t *cur, /* btree cursor */
618 int level) /* level to check */
619{
620 struct xfs_btree_block *block; /* generic btree block pointer */
621 xfs_buf_t *bp; /* buffer containing block */
622
623 block = xfs_btree_get_block(cur, level, &bp);
624 xfs_btree_check_block(cur, block, level, bp);
625 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
626 return block->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK);
627 else
628 return block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK);
629}
630
631/*
632 * Change the cursor to point to the first record at the given level.
633 * Other levels are unaffected.
634 */
635STATIC int /* success=1, failure=0 */
636xfs_btree_firstrec(
637 xfs_btree_cur_t *cur, /* btree cursor */
638 int level) /* level to change */
639{
640 struct xfs_btree_block *block; /* generic btree block pointer */
641 xfs_buf_t *bp; /* buffer containing block */
642
643 /*
644 * Get the block pointer for this level.
645 */
646 block = xfs_btree_get_block(cur, level, &bp);
647 xfs_btree_check_block(cur, block, level, bp);
648 /*
649 * It's empty, there is no such record.
650 */
651 if (!block->bb_numrecs)
652 return 0;
653 /*
654 * Set the ptr value to 1, that's the first record/key.
655 */
656 cur->bc_ptrs[level] = 1;
657 return 1;
658}
659
660/*
661 * Change the cursor to point to the last record in the current block
662 * at the given level. Other levels are unaffected.
663 */
664STATIC int /* success=1, failure=0 */
665xfs_btree_lastrec(
666 xfs_btree_cur_t *cur, /* btree cursor */
667 int level) /* level to change */
668{
669 struct xfs_btree_block *block; /* generic btree block pointer */
670 xfs_buf_t *bp; /* buffer containing block */
671
672 /*
673 * Get the block pointer for this level.
674 */
675 block = xfs_btree_get_block(cur, level, &bp);
676 xfs_btree_check_block(cur, block, level, bp);
677 /*
678 * It's empty, there is no such record.
679 */
680 if (!block->bb_numrecs)
681 return 0;
682 /*
683 * Set the ptr value to numrecs, that's the last record/key.
684 */
685 cur->bc_ptrs[level] = be16_to_cpu(block->bb_numrecs);
686 return 1;
687}
688
689/*
690 * Compute first and last byte offsets for the fields given.
691 * Interprets the offsets table, which contains struct field offsets.
692 */
693void
694xfs_btree_offsets(
695 __int64_t fields, /* bitmask of fields */
696 const short *offsets, /* table of field offsets */
697 int nbits, /* number of bits to inspect */
698 int *first, /* output: first byte offset */
699 int *last) /* output: last byte offset */
700{
701 int i; /* current bit number */
702 __int64_t imask; /* mask for current bit number */
703
704 ASSERT(fields != 0);
705 /*
706 * Find the lowest bit, so the first byte offset.
707 */
708 for (i = 0, imask = 1LL; ; i++, imask <<= 1) {
709 if (imask & fields) {
710 *first = offsets[i];
711 break;
712 }
713 }
714 /*
715 * Find the highest bit, so the last byte offset.
716 */
717 for (i = nbits - 1, imask = 1LL << i; ; i--, imask >>= 1) {
718 if (imask & fields) {
719 *last = offsets[i + 1] - 1;
720 break;
721 }
722 }
723}
724
725/*
726 * Get a buffer for the block, return it read in.
727 * Long-form addressing.
728 */
729int
730xfs_btree_read_bufl(
731 struct xfs_mount *mp, /* file system mount point */
732 struct xfs_trans *tp, /* transaction pointer */
733 xfs_fsblock_t fsbno, /* file system block number */
734 uint lock, /* lock flags for read_buf */
735 struct xfs_buf **bpp, /* buffer for fsbno */
736 int refval, /* ref count value for buffer */
737 const struct xfs_buf_ops *ops)
738{
739 struct xfs_buf *bp; /* return value */
740 xfs_daddr_t d; /* real disk block address */
741 int error;
742
743 ASSERT(fsbno != NULLFSBLOCK);
744 d = XFS_FSB_TO_DADDR(mp, fsbno);
745 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
746 mp->m_bsize, lock, &bp, ops);
747 if (error)
748 return error;
749 if (bp)
750 xfs_buf_set_ref(bp, refval);
751 *bpp = bp;
752 return 0;
753}
754
755/*
756 * Read-ahead the block, don't wait for it, don't return a buffer.
757 * Long-form addressing.
758 */
759/* ARGSUSED */
760void
761xfs_btree_reada_bufl(
762 struct xfs_mount *mp, /* file system mount point */
763 xfs_fsblock_t fsbno, /* file system block number */
764 xfs_extlen_t count, /* count of filesystem blocks */
765 const struct xfs_buf_ops *ops)
766{
767 xfs_daddr_t d;
768
769 ASSERT(fsbno != NULLFSBLOCK);
770 d = XFS_FSB_TO_DADDR(mp, fsbno);
771 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, ops);
772}
773
774/*
775 * Read-ahead the block, don't wait for it, don't return a buffer.
776 * Short-form addressing.
777 */
778/* ARGSUSED */
779void
780xfs_btree_reada_bufs(
781 struct xfs_mount *mp, /* file system mount point */
782 xfs_agnumber_t agno, /* allocation group number */
783 xfs_agblock_t agbno, /* allocation group block number */
784 xfs_extlen_t count, /* count of filesystem blocks */
785 const struct xfs_buf_ops *ops)
786{
787 xfs_daddr_t d;
788
789 ASSERT(agno != NULLAGNUMBER);
790 ASSERT(agbno != NULLAGBLOCK);
791 d = XFS_AGB_TO_DADDR(mp, agno, agbno);
792 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, ops);
793}
794
795STATIC int
796xfs_btree_readahead_lblock(
797 struct xfs_btree_cur *cur,
798 int lr,
799 struct xfs_btree_block *block)
800{
801 int rval = 0;
802 xfs_fsblock_t left = be64_to_cpu(block->bb_u.l.bb_leftsib);
803 xfs_fsblock_t right = be64_to_cpu(block->bb_u.l.bb_rightsib);
804
805 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLFSBLOCK) {
806 xfs_btree_reada_bufl(cur->bc_mp, left, 1,
807 cur->bc_ops->buf_ops);
808 rval++;
809 }
810
811 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLFSBLOCK) {
812 xfs_btree_reada_bufl(cur->bc_mp, right, 1,
813 cur->bc_ops->buf_ops);
814 rval++;
815 }
816
817 return rval;
818}
819
820STATIC int
821xfs_btree_readahead_sblock(
822 struct xfs_btree_cur *cur,
823 int lr,
824 struct xfs_btree_block *block)
825{
826 int rval = 0;
827 xfs_agblock_t left = be32_to_cpu(block->bb_u.s.bb_leftsib);
828 xfs_agblock_t right = be32_to_cpu(block->bb_u.s.bb_rightsib);
829
830
831 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLAGBLOCK) {
832 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
833 left, 1, cur->bc_ops->buf_ops);
834 rval++;
835 }
836
837 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLAGBLOCK) {
838 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
839 right, 1, cur->bc_ops->buf_ops);
840 rval++;
841 }
842
843 return rval;
844}
845
846/*
847 * Read-ahead btree blocks, at the given level.
848 * Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA.
849 */
850STATIC int
851xfs_btree_readahead(
852 struct xfs_btree_cur *cur, /* btree cursor */
853 int lev, /* level in btree */
854 int lr) /* left/right bits */
855{
856 struct xfs_btree_block *block;
857
858 /*
859 * No readahead needed if we are at the root level and the
860 * btree root is stored in the inode.
861 */
862 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
863 (lev == cur->bc_nlevels - 1))
864 return 0;
865
866 if ((cur->bc_ra[lev] | lr) == cur->bc_ra[lev])
867 return 0;
868
869 cur->bc_ra[lev] |= lr;
870 block = XFS_BUF_TO_BLOCK(cur->bc_bufs[lev]);
871
872 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
873 return xfs_btree_readahead_lblock(cur, lr, block);
874 return xfs_btree_readahead_sblock(cur, lr, block);
875}
876
877STATIC xfs_daddr_t
878xfs_btree_ptr_to_daddr(
879 struct xfs_btree_cur *cur,
880 union xfs_btree_ptr *ptr)
881{
882 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
883 ASSERT(ptr->l != cpu_to_be64(NULLFSBLOCK));
884
885 return XFS_FSB_TO_DADDR(cur->bc_mp, be64_to_cpu(ptr->l));
886 } else {
887 ASSERT(cur->bc_private.a.agno != NULLAGNUMBER);
888 ASSERT(ptr->s != cpu_to_be32(NULLAGBLOCK));
889
890 return XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_private.a.agno,
891 be32_to_cpu(ptr->s));
892 }
893}
894
895/*
896 * Readahead @count btree blocks at the given @ptr location.
897 *
898 * We don't need to care about long or short form btrees here as we have a
899 * method of converting the ptr directly to a daddr available to us.
900 */
901STATIC void
902xfs_btree_readahead_ptr(
903 struct xfs_btree_cur *cur,
904 union xfs_btree_ptr *ptr,
905 xfs_extlen_t count)
906{
907 xfs_buf_readahead(cur->bc_mp->m_ddev_targp,
908 xfs_btree_ptr_to_daddr(cur, ptr),
909 cur->bc_mp->m_bsize * count, cur->bc_ops->buf_ops);
910}
911
912/*
913 * Set the buffer for level "lev" in the cursor to bp, releasing
914 * any previous buffer.
915 */
916STATIC void
917xfs_btree_setbuf(
918 xfs_btree_cur_t *cur, /* btree cursor */
919 int lev, /* level in btree */
920 xfs_buf_t *bp) /* new buffer to set */
921{
922 struct xfs_btree_block *b; /* btree block */
923
924 if (cur->bc_bufs[lev])
925 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[lev]);
926 cur->bc_bufs[lev] = bp;
927 cur->bc_ra[lev] = 0;
928
929 b = XFS_BUF_TO_BLOCK(bp);
930 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
931 if (b->bb_u.l.bb_leftsib == cpu_to_be64(NULLFSBLOCK))
932 cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
933 if (b->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK))
934 cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
935 } else {
936 if (b->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK))
937 cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
938 if (b->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK))
939 cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
940 }
941}
942
943STATIC int
944xfs_btree_ptr_is_null(
945 struct xfs_btree_cur *cur,
946 union xfs_btree_ptr *ptr)
947{
948 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
949 return ptr->l == cpu_to_be64(NULLFSBLOCK);
950 else
951 return ptr->s == cpu_to_be32(NULLAGBLOCK);
952}
953
954STATIC void
955xfs_btree_set_ptr_null(
956 struct xfs_btree_cur *cur,
957 union xfs_btree_ptr *ptr)
958{
959 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
960 ptr->l = cpu_to_be64(NULLFSBLOCK);
961 else
962 ptr->s = cpu_to_be32(NULLAGBLOCK);
963}
964
965/*
966 * Get/set/init sibling pointers
967 */
968STATIC void
969xfs_btree_get_sibling(
970 struct xfs_btree_cur *cur,
971 struct xfs_btree_block *block,
972 union xfs_btree_ptr *ptr,
973 int lr)
974{
975 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
976
977 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
978 if (lr == XFS_BB_RIGHTSIB)
979 ptr->l = block->bb_u.l.bb_rightsib;
980 else
981 ptr->l = block->bb_u.l.bb_leftsib;
982 } else {
983 if (lr == XFS_BB_RIGHTSIB)
984 ptr->s = block->bb_u.s.bb_rightsib;
985 else
986 ptr->s = block->bb_u.s.bb_leftsib;
987 }
988}
989
990STATIC void
991xfs_btree_set_sibling(
992 struct xfs_btree_cur *cur,
993 struct xfs_btree_block *block,
994 union xfs_btree_ptr *ptr,
995 int lr)
996{
997 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
998
999 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1000 if (lr == XFS_BB_RIGHTSIB)
1001 block->bb_u.l.bb_rightsib = ptr->l;
1002 else
1003 block->bb_u.l.bb_leftsib = ptr->l;
1004 } else {
1005 if (lr == XFS_BB_RIGHTSIB)
1006 block->bb_u.s.bb_rightsib = ptr->s;
1007 else
1008 block->bb_u.s.bb_leftsib = ptr->s;
1009 }
1010}
1011
1012void
1013xfs_btree_init_block_int(
1014 struct xfs_mount *mp,
1015 struct xfs_btree_block *buf,
1016 xfs_daddr_t blkno,
1017 __u32 magic,
1018 __u16 level,
1019 __u16 numrecs,
1020 __u64 owner,
1021 unsigned int flags)
1022{
1023 buf->bb_magic = cpu_to_be32(magic);
1024 buf->bb_level = cpu_to_be16(level);
1025 buf->bb_numrecs = cpu_to_be16(numrecs);
1026
1027 if (flags & XFS_BTREE_LONG_PTRS) {
1028 buf->bb_u.l.bb_leftsib = cpu_to_be64(NULLFSBLOCK);
1029 buf->bb_u.l.bb_rightsib = cpu_to_be64(NULLFSBLOCK);
1030 if (flags & XFS_BTREE_CRC_BLOCKS) {
1031 buf->bb_u.l.bb_blkno = cpu_to_be64(blkno);
1032 buf->bb_u.l.bb_owner = cpu_to_be64(owner);
1033 uuid_copy(&buf->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid);
1034 buf->bb_u.l.bb_pad = 0;
1035 buf->bb_u.l.bb_lsn = 0;
1036 }
1037 } else {
1038 /* owner is a 32 bit value on short blocks */
1039 __u32 __owner = (__u32)owner;
1040
1041 buf->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
1042 buf->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
1043 if (flags & XFS_BTREE_CRC_BLOCKS) {
1044 buf->bb_u.s.bb_blkno = cpu_to_be64(blkno);
1045 buf->bb_u.s.bb_owner = cpu_to_be32(__owner);
1046 uuid_copy(&buf->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid);
1047 buf->bb_u.s.bb_lsn = 0;
1048 }
1049 }
1050}
1051
1052void
1053xfs_btree_init_block(
1054 struct xfs_mount *mp,
1055 struct xfs_buf *bp,
1056 __u32 magic,
1057 __u16 level,
1058 __u16 numrecs,
1059 __u64 owner,
1060 unsigned int flags)
1061{
1062 xfs_btree_init_block_int(mp, XFS_BUF_TO_BLOCK(bp), bp->b_bn,
1063 magic, level, numrecs, owner, flags);
1064}
1065
1066STATIC void
1067xfs_btree_init_block_cur(
1068 struct xfs_btree_cur *cur,
1069 struct xfs_buf *bp,
1070 int level,
1071 int numrecs)
1072{
1073 __u64 owner;
1074
1075 /*
1076 * we can pull the owner from the cursor right now as the different
1077 * owners align directly with the pointer size of the btree. This may
1078 * change in future, but is safe for current users of the generic btree
1079 * code.
1080 */
1081 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1082 owner = cur->bc_private.b.ip->i_ino;
1083 else
1084 owner = cur->bc_private.a.agno;
1085
1086 xfs_btree_init_block_int(cur->bc_mp, XFS_BUF_TO_BLOCK(bp), bp->b_bn,
1087 xfs_btree_magic(cur), level, numrecs,
1088 owner, cur->bc_flags);
1089}
1090
1091/*
1092 * Return true if ptr is the last record in the btree and
1093 * we need to track updates to this record. The decision
1094 * will be further refined in the update_lastrec method.
1095 */
1096STATIC int
1097xfs_btree_is_lastrec(
1098 struct xfs_btree_cur *cur,
1099 struct xfs_btree_block *block,
1100 int level)
1101{
1102 union xfs_btree_ptr ptr;
1103
1104 if (level > 0)
1105 return 0;
1106 if (!(cur->bc_flags & XFS_BTREE_LASTREC_UPDATE))
1107 return 0;
1108
1109 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1110 if (!xfs_btree_ptr_is_null(cur, &ptr))
1111 return 0;
1112 return 1;
1113}
1114
1115STATIC void
1116xfs_btree_buf_to_ptr(
1117 struct xfs_btree_cur *cur,
1118 struct xfs_buf *bp,
1119 union xfs_btree_ptr *ptr)
1120{
1121 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1122 ptr->l = cpu_to_be64(XFS_DADDR_TO_FSB(cur->bc_mp,
1123 XFS_BUF_ADDR(bp)));
1124 else {
1125 ptr->s = cpu_to_be32(xfs_daddr_to_agbno(cur->bc_mp,
1126 XFS_BUF_ADDR(bp)));
1127 }
1128}
1129
1130STATIC void
1131xfs_btree_set_refs(
1132 struct xfs_btree_cur *cur,
1133 struct xfs_buf *bp)
1134{
1135 switch (cur->bc_btnum) {
1136 case XFS_BTNUM_BNO:
1137 case XFS_BTNUM_CNT:
1138 xfs_buf_set_ref(bp, XFS_ALLOC_BTREE_REF);
1139 break;
1140 case XFS_BTNUM_INO:
1141 case XFS_BTNUM_FINO:
1142 xfs_buf_set_ref(bp, XFS_INO_BTREE_REF);
1143 break;
1144 case XFS_BTNUM_BMAP:
1145 xfs_buf_set_ref(bp, XFS_BMAP_BTREE_REF);
1146 break;
1147 default:
1148 ASSERT(0);
1149 }
1150}
1151
1152STATIC int
1153xfs_btree_get_buf_block(
1154 struct xfs_btree_cur *cur,
1155 union xfs_btree_ptr *ptr,
1156 int flags,
1157 struct xfs_btree_block **block,
1158 struct xfs_buf **bpp)
1159{
1160 struct xfs_mount *mp = cur->bc_mp;
1161 xfs_daddr_t d;
1162
1163 /* need to sort out how callers deal with failures first */
1164 ASSERT(!(flags & XBF_TRYLOCK));
1165
1166 d = xfs_btree_ptr_to_daddr(cur, ptr);
1167 *bpp = xfs_trans_get_buf(cur->bc_tp, mp->m_ddev_targp, d,
1168 mp->m_bsize, flags);
1169
1170 if (!*bpp)
1171 return -ENOMEM;
1172
1173 (*bpp)->b_ops = cur->bc_ops->buf_ops;
1174 *block = XFS_BUF_TO_BLOCK(*bpp);
1175 return 0;
1176}
1177
1178/*
1179 * Read in the buffer at the given ptr and return the buffer and
1180 * the block pointer within the buffer.
1181 */
1182STATIC int
1183xfs_btree_read_buf_block(
1184 struct xfs_btree_cur *cur,
1185 union xfs_btree_ptr *ptr,
1186 int flags,
1187 struct xfs_btree_block **block,
1188 struct xfs_buf **bpp)
1189{
1190 struct xfs_mount *mp = cur->bc_mp;
1191 xfs_daddr_t d;
1192 int error;
1193
1194 /* need to sort out how callers deal with failures first */
1195 ASSERT(!(flags & XBF_TRYLOCK));
1196
1197 d = xfs_btree_ptr_to_daddr(cur, ptr);
1198 error = xfs_trans_read_buf(mp, cur->bc_tp, mp->m_ddev_targp, d,
1199 mp->m_bsize, flags, bpp,
1200 cur->bc_ops->buf_ops);
1201 if (error)
1202 return error;
1203
1204 xfs_btree_set_refs(cur, *bpp);
1205 *block = XFS_BUF_TO_BLOCK(*bpp);
1206 return 0;
1207}
1208
1209/*
1210 * Copy keys from one btree block to another.
1211 */
1212STATIC void
1213xfs_btree_copy_keys(
1214 struct xfs_btree_cur *cur,
1215 union xfs_btree_key *dst_key,
1216 union xfs_btree_key *src_key,
1217 int numkeys)
1218{
1219 ASSERT(numkeys >= 0);
1220 memcpy(dst_key, src_key, numkeys * cur->bc_ops->key_len);
1221}
1222
1223/*
1224 * Copy records from one btree block to another.
1225 */
1226STATIC void
1227xfs_btree_copy_recs(
1228 struct xfs_btree_cur *cur,
1229 union xfs_btree_rec *dst_rec,
1230 union xfs_btree_rec *src_rec,
1231 int numrecs)
1232{
1233 ASSERT(numrecs >= 0);
1234 memcpy(dst_rec, src_rec, numrecs * cur->bc_ops->rec_len);
1235}
1236
1237/*
1238 * Copy block pointers from one btree block to another.
1239 */
1240STATIC void
1241xfs_btree_copy_ptrs(
1242 struct xfs_btree_cur *cur,
1243 union xfs_btree_ptr *dst_ptr,
1244 union xfs_btree_ptr *src_ptr,
1245 int numptrs)
1246{
1247 ASSERT(numptrs >= 0);
1248 memcpy(dst_ptr, src_ptr, numptrs * xfs_btree_ptr_len(cur));
1249}
1250
1251/*
1252 * Shift keys one index left/right inside a single btree block.
1253 */
1254STATIC void
1255xfs_btree_shift_keys(
1256 struct xfs_btree_cur *cur,
1257 union xfs_btree_key *key,
1258 int dir,
1259 int numkeys)
1260{
1261 char *dst_key;
1262
1263 ASSERT(numkeys >= 0);
1264 ASSERT(dir == 1 || dir == -1);
1265
1266 dst_key = (char *)key + (dir * cur->bc_ops->key_len);
1267 memmove(dst_key, key, numkeys * cur->bc_ops->key_len);
1268}
1269
1270/*
1271 * Shift records one index left/right inside a single btree block.
1272 */
1273STATIC void
1274xfs_btree_shift_recs(
1275 struct xfs_btree_cur *cur,
1276 union xfs_btree_rec *rec,
1277 int dir,
1278 int numrecs)
1279{
1280 char *dst_rec;
1281
1282 ASSERT(numrecs >= 0);
1283 ASSERT(dir == 1 || dir == -1);
1284
1285 dst_rec = (char *)rec + (dir * cur->bc_ops->rec_len);
1286 memmove(dst_rec, rec, numrecs * cur->bc_ops->rec_len);
1287}
1288
1289/*
1290 * Shift block pointers one index left/right inside a single btree block.
1291 */
1292STATIC void
1293xfs_btree_shift_ptrs(
1294 struct xfs_btree_cur *cur,
1295 union xfs_btree_ptr *ptr,
1296 int dir,
1297 int numptrs)
1298{
1299 char *dst_ptr;
1300
1301 ASSERT(numptrs >= 0);
1302 ASSERT(dir == 1 || dir == -1);
1303
1304 dst_ptr = (char *)ptr + (dir * xfs_btree_ptr_len(cur));
1305 memmove(dst_ptr, ptr, numptrs * xfs_btree_ptr_len(cur));
1306}
1307
1308/*
1309 * Log key values from the btree block.
1310 */
1311STATIC void
1312xfs_btree_log_keys(
1313 struct xfs_btree_cur *cur,
1314 struct xfs_buf *bp,
1315 int first,
1316 int last)
1317{
1318 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1319 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1320
1321 if (bp) {
1322 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1323 xfs_trans_log_buf(cur->bc_tp, bp,
1324 xfs_btree_key_offset(cur, first),
1325 xfs_btree_key_offset(cur, last + 1) - 1);
1326 } else {
1327 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1328 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1329 }
1330
1331 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1332}
1333
1334/*
1335 * Log record values from the btree block.
1336 */
1337void
1338xfs_btree_log_recs(
1339 struct xfs_btree_cur *cur,
1340 struct xfs_buf *bp,
1341 int first,
1342 int last)
1343{
1344 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1345 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1346
1347 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1348 xfs_trans_log_buf(cur->bc_tp, bp,
1349 xfs_btree_rec_offset(cur, first),
1350 xfs_btree_rec_offset(cur, last + 1) - 1);
1351
1352 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1353}
1354
1355/*
1356 * Log block pointer fields from a btree block (nonleaf).
1357 */
1358STATIC void
1359xfs_btree_log_ptrs(
1360 struct xfs_btree_cur *cur, /* btree cursor */
1361 struct xfs_buf *bp, /* buffer containing btree block */
1362 int first, /* index of first pointer to log */
1363 int last) /* index of last pointer to log */
1364{
1365 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1366 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1367
1368 if (bp) {
1369 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
1370 int level = xfs_btree_get_level(block);
1371
1372 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1373 xfs_trans_log_buf(cur->bc_tp, bp,
1374 xfs_btree_ptr_offset(cur, first, level),
1375 xfs_btree_ptr_offset(cur, last + 1, level) - 1);
1376 } else {
1377 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1378 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1379 }
1380
1381 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1382}
1383
1384/*
1385 * Log fields from a btree block header.
1386 */
1387void
1388xfs_btree_log_block(
1389 struct xfs_btree_cur *cur, /* btree cursor */
1390 struct xfs_buf *bp, /* buffer containing btree block */
1391 int fields) /* mask of fields: XFS_BB_... */
1392{
1393 int first; /* first byte offset logged */
1394 int last; /* last byte offset logged */
1395 static const short soffsets[] = { /* table of offsets (short) */
1396 offsetof(struct xfs_btree_block, bb_magic),
1397 offsetof(struct xfs_btree_block, bb_level),
1398 offsetof(struct xfs_btree_block, bb_numrecs),
1399 offsetof(struct xfs_btree_block, bb_u.s.bb_leftsib),
1400 offsetof(struct xfs_btree_block, bb_u.s.bb_rightsib),
1401 offsetof(struct xfs_btree_block, bb_u.s.bb_blkno),
1402 offsetof(struct xfs_btree_block, bb_u.s.bb_lsn),
1403 offsetof(struct xfs_btree_block, bb_u.s.bb_uuid),
1404 offsetof(struct xfs_btree_block, bb_u.s.bb_owner),
1405 offsetof(struct xfs_btree_block, bb_u.s.bb_crc),
1406 XFS_BTREE_SBLOCK_CRC_LEN
1407 };
1408 static const short loffsets[] = { /* table of offsets (long) */
1409 offsetof(struct xfs_btree_block, bb_magic),
1410 offsetof(struct xfs_btree_block, bb_level),
1411 offsetof(struct xfs_btree_block, bb_numrecs),
1412 offsetof(struct xfs_btree_block, bb_u.l.bb_leftsib),
1413 offsetof(struct xfs_btree_block, bb_u.l.bb_rightsib),
1414 offsetof(struct xfs_btree_block, bb_u.l.bb_blkno),
1415 offsetof(struct xfs_btree_block, bb_u.l.bb_lsn),
1416 offsetof(struct xfs_btree_block, bb_u.l.bb_uuid),
1417 offsetof(struct xfs_btree_block, bb_u.l.bb_owner),
1418 offsetof(struct xfs_btree_block, bb_u.l.bb_crc),
1419 offsetof(struct xfs_btree_block, bb_u.l.bb_pad),
1420 XFS_BTREE_LBLOCK_CRC_LEN
1421 };
1422
1423 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1424 XFS_BTREE_TRACE_ARGBI(cur, bp, fields);
1425
1426 if (bp) {
1427 int nbits;
1428
1429 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) {
1430 /*
1431 * We don't log the CRC when updating a btree
1432 * block but instead recreate it during log
1433 * recovery. As the log buffers have checksums
1434 * of their own this is safe and avoids logging a crc
1435 * update in a lot of places.
1436 */
1437 if (fields == XFS_BB_ALL_BITS)
1438 fields = XFS_BB_ALL_BITS_CRC;
1439 nbits = XFS_BB_NUM_BITS_CRC;
1440 } else {
1441 nbits = XFS_BB_NUM_BITS;
1442 }
1443 xfs_btree_offsets(fields,
1444 (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
1445 loffsets : soffsets,
1446 nbits, &first, &last);
1447 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1448 xfs_trans_log_buf(cur->bc_tp, bp, first, last);
1449 } else {
1450 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1451 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1452 }
1453
1454 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1455}
1456
1457/*
1458 * Increment cursor by one record at the level.
1459 * For nonzero levels the leaf-ward information is untouched.
1460 */
1461int /* error */
1462xfs_btree_increment(
1463 struct xfs_btree_cur *cur,
1464 int level,
1465 int *stat) /* success/failure */
1466{
1467 struct xfs_btree_block *block;
1468 union xfs_btree_ptr ptr;
1469 struct xfs_buf *bp;
1470 int error; /* error return value */
1471 int lev;
1472
1473 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1474 XFS_BTREE_TRACE_ARGI(cur, level);
1475
1476 ASSERT(level < cur->bc_nlevels);
1477
1478 /* Read-ahead to the right at this level. */
1479 xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
1480
1481 /* Get a pointer to the btree block. */
1482 block = xfs_btree_get_block(cur, level, &bp);
1483
1484#ifdef DEBUG
1485 error = xfs_btree_check_block(cur, block, level, bp);
1486 if (error)
1487 goto error0;
1488#endif
1489
1490 /* We're done if we remain in the block after the increment. */
1491 if (++cur->bc_ptrs[level] <= xfs_btree_get_numrecs(block))
1492 goto out1;
1493
1494 /* Fail if we just went off the right edge of the tree. */
1495 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1496 if (xfs_btree_ptr_is_null(cur, &ptr))
1497 goto out0;
1498
1499 XFS_BTREE_STATS_INC(cur, increment);
1500
1501 /*
1502 * March up the tree incrementing pointers.
1503 * Stop when we don't go off the right edge of a block.
1504 */
1505 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1506 block = xfs_btree_get_block(cur, lev, &bp);
1507
1508#ifdef DEBUG
1509 error = xfs_btree_check_block(cur, block, lev, bp);
1510 if (error)
1511 goto error0;
1512#endif
1513
1514 if (++cur->bc_ptrs[lev] <= xfs_btree_get_numrecs(block))
1515 break;
1516
1517 /* Read-ahead the right block for the next loop. */
1518 xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA);
1519 }
1520
1521 /*
1522 * If we went off the root then we are either seriously
1523 * confused or have the tree root in an inode.
1524 */
1525 if (lev == cur->bc_nlevels) {
1526 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1527 goto out0;
1528 ASSERT(0);
1529 error = -EFSCORRUPTED;
1530 goto error0;
1531 }
1532 ASSERT(lev < cur->bc_nlevels);
1533
1534 /*
1535 * Now walk back down the tree, fixing up the cursor's buffer
1536 * pointers and key numbers.
1537 */
1538 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1539 union xfs_btree_ptr *ptrp;
1540
1541 ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1542 --lev;
1543 error = xfs_btree_read_buf_block(cur, ptrp, 0, &block, &bp);
1544 if (error)
1545 goto error0;
1546
1547 xfs_btree_setbuf(cur, lev, bp);
1548 cur->bc_ptrs[lev] = 1;
1549 }
1550out1:
1551 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1552 *stat = 1;
1553 return 0;
1554
1555out0:
1556 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1557 *stat = 0;
1558 return 0;
1559
1560error0:
1561 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1562 return error;
1563}
1564
1565/*
1566 * Decrement cursor by one record at the level.
1567 * For nonzero levels the leaf-ward information is untouched.
1568 */
1569int /* error */
1570xfs_btree_decrement(
1571 struct xfs_btree_cur *cur,
1572 int level,
1573 int *stat) /* success/failure */
1574{
1575 struct xfs_btree_block *block;
1576 xfs_buf_t *bp;
1577 int error; /* error return value */
1578 int lev;
1579 union xfs_btree_ptr ptr;
1580
1581 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1582 XFS_BTREE_TRACE_ARGI(cur, level);
1583
1584 ASSERT(level < cur->bc_nlevels);
1585
1586 /* Read-ahead to the left at this level. */
1587 xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA);
1588
1589 /* We're done if we remain in the block after the decrement. */
1590 if (--cur->bc_ptrs[level] > 0)
1591 goto out1;
1592
1593 /* Get a pointer to the btree block. */
1594 block = xfs_btree_get_block(cur, level, &bp);
1595
1596#ifdef DEBUG
1597 error = xfs_btree_check_block(cur, block, level, bp);
1598 if (error)
1599 goto error0;
1600#endif
1601
1602 /* Fail if we just went off the left edge of the tree. */
1603 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
1604 if (xfs_btree_ptr_is_null(cur, &ptr))
1605 goto out0;
1606
1607 XFS_BTREE_STATS_INC(cur, decrement);
1608
1609 /*
1610 * March up the tree decrementing pointers.
1611 * Stop when we don't go off the left edge of a block.
1612 */
1613 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1614 if (--cur->bc_ptrs[lev] > 0)
1615 break;
1616 /* Read-ahead the left block for the next loop. */
1617 xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA);
1618 }
1619
1620 /*
1621 * If we went off the root then we are seriously confused.
1622 * or the root of the tree is in an inode.
1623 */
1624 if (lev == cur->bc_nlevels) {
1625 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1626 goto out0;
1627 ASSERT(0);
1628 error = -EFSCORRUPTED;
1629 goto error0;
1630 }
1631 ASSERT(lev < cur->bc_nlevels);
1632
1633 /*
1634 * Now walk back down the tree, fixing up the cursor's buffer
1635 * pointers and key numbers.
1636 */
1637 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1638 union xfs_btree_ptr *ptrp;
1639
1640 ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1641 --lev;
1642 error = xfs_btree_read_buf_block(cur, ptrp, 0, &block, &bp);
1643 if (error)
1644 goto error0;
1645 xfs_btree_setbuf(cur, lev, bp);
1646 cur->bc_ptrs[lev] = xfs_btree_get_numrecs(block);
1647 }
1648out1:
1649 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1650 *stat = 1;
1651 return 0;
1652
1653out0:
1654 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1655 *stat = 0;
1656 return 0;
1657
1658error0:
1659 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1660 return error;
1661}
1662
1663STATIC int
1664xfs_btree_lookup_get_block(
1665 struct xfs_btree_cur *cur, /* btree cursor */
1666 int level, /* level in the btree */
1667 union xfs_btree_ptr *pp, /* ptr to btree block */
1668 struct xfs_btree_block **blkp) /* return btree block */
1669{
1670 struct xfs_buf *bp; /* buffer pointer for btree block */
1671 int error = 0;
1672
1673 /* special case the root block if in an inode */
1674 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1675 (level == cur->bc_nlevels - 1)) {
1676 *blkp = xfs_btree_get_iroot(cur);
1677 return 0;
1678 }
1679
1680 /*
1681 * If the old buffer at this level for the disk address we are
1682 * looking for re-use it.
1683 *
1684 * Otherwise throw it away and get a new one.
1685 */
1686 bp = cur->bc_bufs[level];
1687 if (bp && XFS_BUF_ADDR(bp) == xfs_btree_ptr_to_daddr(cur, pp)) {
1688 *blkp = XFS_BUF_TO_BLOCK(bp);
1689 return 0;
1690 }
1691
1692 error = xfs_btree_read_buf_block(cur, pp, 0, blkp, &bp);
1693 if (error)
1694 return error;
1695
1696 xfs_btree_setbuf(cur, level, bp);
1697 return 0;
1698}
1699
1700/*
1701 * Get current search key. For level 0 we don't actually have a key
1702 * structure so we make one up from the record. For all other levels
1703 * we just return the right key.
1704 */
1705STATIC union xfs_btree_key *
1706xfs_lookup_get_search_key(
1707 struct xfs_btree_cur *cur,
1708 int level,
1709 int keyno,
1710 struct xfs_btree_block *block,
1711 union xfs_btree_key *kp)
1712{
1713 if (level == 0) {
1714 cur->bc_ops->init_key_from_rec(kp,
1715 xfs_btree_rec_addr(cur, keyno, block));
1716 return kp;
1717 }
1718
1719 return xfs_btree_key_addr(cur, keyno, block);
1720}
1721
1722/*
1723 * Lookup the record. The cursor is made to point to it, based on dir.
1724 * stat is set to 0 if can't find any such record, 1 for success.
1725 */
1726int /* error */
1727xfs_btree_lookup(
1728 struct xfs_btree_cur *cur, /* btree cursor */
1729 xfs_lookup_t dir, /* <=, ==, or >= */
1730 int *stat) /* success/failure */
1731{
1732 struct xfs_btree_block *block; /* current btree block */
1733 __int64_t diff; /* difference for the current key */
1734 int error; /* error return value */
1735 int keyno; /* current key number */
1736 int level; /* level in the btree */
1737 union xfs_btree_ptr *pp; /* ptr to btree block */
1738 union xfs_btree_ptr ptr; /* ptr to btree block */
1739
1740 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1741 XFS_BTREE_TRACE_ARGI(cur, dir);
1742
1743 XFS_BTREE_STATS_INC(cur, lookup);
1744
1745 block = NULL;
1746 keyno = 0;
1747
1748 /* initialise start pointer from cursor */
1749 cur->bc_ops->init_ptr_from_cur(cur, &ptr);
1750 pp = &ptr;
1751
1752 /*
1753 * Iterate over each level in the btree, starting at the root.
1754 * For each level above the leaves, find the key we need, based
1755 * on the lookup record, then follow the corresponding block
1756 * pointer down to the next level.
1757 */
1758 for (level = cur->bc_nlevels - 1, diff = 1; level >= 0; level--) {
1759 /* Get the block we need to do the lookup on. */
1760 error = xfs_btree_lookup_get_block(cur, level, pp, &block);
1761 if (error)
1762 goto error0;
1763
1764 if (diff == 0) {
1765 /*
1766 * If we already had a key match at a higher level, we
1767 * know we need to use the first entry in this block.
1768 */
1769 keyno = 1;
1770 } else {
1771 /* Otherwise search this block. Do a binary search. */
1772
1773 int high; /* high entry number */
1774 int low; /* low entry number */
1775
1776 /* Set low and high entry numbers, 1-based. */
1777 low = 1;
1778 high = xfs_btree_get_numrecs(block);
1779 if (!high) {
1780 /* Block is empty, must be an empty leaf. */
1781 ASSERT(level == 0 && cur->bc_nlevels == 1);
1782
1783 cur->bc_ptrs[0] = dir != XFS_LOOKUP_LE;
1784 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1785 *stat = 0;
1786 return 0;
1787 }
1788
1789 /* Binary search the block. */
1790 while (low <= high) {
1791 union xfs_btree_key key;
1792 union xfs_btree_key *kp;
1793
1794 XFS_BTREE_STATS_INC(cur, compare);
1795
1796 /* keyno is average of low and high. */
1797 keyno = (low + high) >> 1;
1798
1799 /* Get current search key */
1800 kp = xfs_lookup_get_search_key(cur, level,
1801 keyno, block, &key);
1802
1803 /*
1804 * Compute difference to get next direction:
1805 * - less than, move right
1806 * - greater than, move left
1807 * - equal, we're done
1808 */
1809 diff = cur->bc_ops->key_diff(cur, kp);
1810 if (diff < 0)
1811 low = keyno + 1;
1812 else if (diff > 0)
1813 high = keyno - 1;
1814 else
1815 break;
1816 }
1817 }
1818
1819 /*
1820 * If there are more levels, set up for the next level
1821 * by getting the block number and filling in the cursor.
1822 */
1823 if (level > 0) {
1824 /*
1825 * If we moved left, need the previous key number,
1826 * unless there isn't one.
1827 */
1828 if (diff > 0 && --keyno < 1)
1829 keyno = 1;
1830 pp = xfs_btree_ptr_addr(cur, keyno, block);
1831
1832#ifdef DEBUG
1833 error = xfs_btree_check_ptr(cur, pp, 0, level);
1834 if (error)
1835 goto error0;
1836#endif
1837 cur->bc_ptrs[level] = keyno;
1838 }
1839 }
1840
1841 /* Done with the search. See if we need to adjust the results. */
1842 if (dir != XFS_LOOKUP_LE && diff < 0) {
1843 keyno++;
1844 /*
1845 * If ge search and we went off the end of the block, but it's
1846 * not the last block, we're in the wrong block.
1847 */
1848 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1849 if (dir == XFS_LOOKUP_GE &&
1850 keyno > xfs_btree_get_numrecs(block) &&
1851 !xfs_btree_ptr_is_null(cur, &ptr)) {
1852 int i;
1853
1854 cur->bc_ptrs[0] = keyno;
1855 error = xfs_btree_increment(cur, 0, &i);
1856 if (error)
1857 goto error0;
1858 XFS_WANT_CORRUPTED_RETURN(cur->bc_mp, i == 1);
1859 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1860 *stat = 1;
1861 return 0;
1862 }
1863 } else if (dir == XFS_LOOKUP_LE && diff > 0)
1864 keyno--;
1865 cur->bc_ptrs[0] = keyno;
1866
1867 /* Return if we succeeded or not. */
1868 if (keyno == 0 || keyno > xfs_btree_get_numrecs(block))
1869 *stat = 0;
1870 else if (dir != XFS_LOOKUP_EQ || diff == 0)
1871 *stat = 1;
1872 else
1873 *stat = 0;
1874 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1875 return 0;
1876
1877error0:
1878 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1879 return error;
1880}
1881
1882/*
1883 * Update keys at all levels from here to the root along the cursor's path.
1884 */
1885STATIC int
1886xfs_btree_updkey(
1887 struct xfs_btree_cur *cur,
1888 union xfs_btree_key *keyp,
1889 int level)
1890{
1891 struct xfs_btree_block *block;
1892 struct xfs_buf *bp;
1893 union xfs_btree_key *kp;
1894 int ptr;
1895
1896 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1897 XFS_BTREE_TRACE_ARGIK(cur, level, keyp);
1898
1899 ASSERT(!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) || level >= 1);
1900
1901 /*
1902 * Go up the tree from this level toward the root.
1903 * At each level, update the key value to the value input.
1904 * Stop when we reach a level where the cursor isn't pointing
1905 * at the first entry in the block.
1906 */
1907 for (ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) {
1908#ifdef DEBUG
1909 int error;
1910#endif
1911 block = xfs_btree_get_block(cur, level, &bp);
1912#ifdef DEBUG
1913 error = xfs_btree_check_block(cur, block, level, bp);
1914 if (error) {
1915 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1916 return error;
1917 }
1918#endif
1919 ptr = cur->bc_ptrs[level];
1920 kp = xfs_btree_key_addr(cur, ptr, block);
1921 xfs_btree_copy_keys(cur, kp, keyp, 1);
1922 xfs_btree_log_keys(cur, bp, ptr, ptr);
1923 }
1924
1925 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1926 return 0;
1927}
1928
1929/*
1930 * Update the record referred to by cur to the value in the
1931 * given record. This either works (return 0) or gets an
1932 * EFSCORRUPTED error.
1933 */
1934int
1935xfs_btree_update(
1936 struct xfs_btree_cur *cur,
1937 union xfs_btree_rec *rec)
1938{
1939 struct xfs_btree_block *block;
1940 struct xfs_buf *bp;
1941 int error;
1942 int ptr;
1943 union xfs_btree_rec *rp;
1944
1945 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1946 XFS_BTREE_TRACE_ARGR(cur, rec);
1947
1948 /* Pick up the current block. */
1949 block = xfs_btree_get_block(cur, 0, &bp);
1950
1951#ifdef DEBUG
1952 error = xfs_btree_check_block(cur, block, 0, bp);
1953 if (error)
1954 goto error0;
1955#endif
1956 /* Get the address of the rec to be updated. */
1957 ptr = cur->bc_ptrs[0];
1958 rp = xfs_btree_rec_addr(cur, ptr, block);
1959
1960 /* Fill in the new contents and log them. */
1961 xfs_btree_copy_recs(cur, rp, rec, 1);
1962 xfs_btree_log_recs(cur, bp, ptr, ptr);
1963
1964 /*
1965 * If we are tracking the last record in the tree and
1966 * we are at the far right edge of the tree, update it.
1967 */
1968 if (xfs_btree_is_lastrec(cur, block, 0)) {
1969 cur->bc_ops->update_lastrec(cur, block, rec,
1970 ptr, LASTREC_UPDATE);
1971 }
1972
1973 /* Updating first rec in leaf. Pass new key value up to our parent. */
1974 if (ptr == 1) {
1975 union xfs_btree_key key;
1976
1977 cur->bc_ops->init_key_from_rec(&key, rec);
1978 error = xfs_btree_updkey(cur, &key, 1);
1979 if (error)
1980 goto error0;
1981 }
1982
1983 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1984 return 0;
1985
1986error0:
1987 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1988 return error;
1989}
1990
1991/*
1992 * Move 1 record left from cur/level if possible.
1993 * Update cur to reflect the new path.
1994 */
1995STATIC int /* error */
1996xfs_btree_lshift(
1997 struct xfs_btree_cur *cur,
1998 int level,
1999 int *stat) /* success/failure */
2000{
2001 union xfs_btree_key key; /* btree key */
2002 struct xfs_buf *lbp; /* left buffer pointer */
2003 struct xfs_btree_block *left; /* left btree block */
2004 int lrecs; /* left record count */
2005 struct xfs_buf *rbp; /* right buffer pointer */
2006 struct xfs_btree_block *right; /* right btree block */
2007 int rrecs; /* right record count */
2008 union xfs_btree_ptr lptr; /* left btree pointer */
2009 union xfs_btree_key *rkp = NULL; /* right btree key */
2010 union xfs_btree_ptr *rpp = NULL; /* right address pointer */
2011 union xfs_btree_rec *rrp = NULL; /* right record pointer */
2012 int error; /* error return value */
2013
2014 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2015 XFS_BTREE_TRACE_ARGI(cur, level);
2016
2017 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2018 level == cur->bc_nlevels - 1)
2019 goto out0;
2020
2021 /* Set up variables for this block as "right". */
2022 right = xfs_btree_get_block(cur, level, &rbp);
2023
2024#ifdef DEBUG
2025 error = xfs_btree_check_block(cur, right, level, rbp);
2026 if (error)
2027 goto error0;
2028#endif
2029
2030 /* If we've got no left sibling then we can't shift an entry left. */
2031 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2032 if (xfs_btree_ptr_is_null(cur, &lptr))
2033 goto out0;
2034
2035 /*
2036 * If the cursor entry is the one that would be moved, don't
2037 * do it... it's too complicated.
2038 */
2039 if (cur->bc_ptrs[level] <= 1)
2040 goto out0;
2041
2042 /* Set up the left neighbor as "left". */
2043 error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
2044 if (error)
2045 goto error0;
2046
2047 /* If it's full, it can't take another entry. */
2048 lrecs = xfs_btree_get_numrecs(left);
2049 if (lrecs == cur->bc_ops->get_maxrecs(cur, level))
2050 goto out0;
2051
2052 rrecs = xfs_btree_get_numrecs(right);
2053
2054 /*
2055 * We add one entry to the left side and remove one for the right side.
2056 * Account for it here, the changes will be updated on disk and logged
2057 * later.
2058 */
2059 lrecs++;
2060 rrecs--;
2061
2062 XFS_BTREE_STATS_INC(cur, lshift);
2063 XFS_BTREE_STATS_ADD(cur, moves, 1);
2064
2065 /*
2066 * If non-leaf, copy a key and a ptr to the left block.
2067 * Log the changes to the left block.
2068 */
2069 if (level > 0) {
2070 /* It's a non-leaf. Move keys and pointers. */
2071 union xfs_btree_key *lkp; /* left btree key */
2072 union xfs_btree_ptr *lpp; /* left address pointer */
2073
2074 lkp = xfs_btree_key_addr(cur, lrecs, left);
2075 rkp = xfs_btree_key_addr(cur, 1, right);
2076
2077 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2078 rpp = xfs_btree_ptr_addr(cur, 1, right);
2079#ifdef DEBUG
2080 error = xfs_btree_check_ptr(cur, rpp, 0, level);
2081 if (error)
2082 goto error0;
2083#endif
2084 xfs_btree_copy_keys(cur, lkp, rkp, 1);
2085 xfs_btree_copy_ptrs(cur, lpp, rpp, 1);
2086
2087 xfs_btree_log_keys(cur, lbp, lrecs, lrecs);
2088 xfs_btree_log_ptrs(cur, lbp, lrecs, lrecs);
2089
2090 ASSERT(cur->bc_ops->keys_inorder(cur,
2091 xfs_btree_key_addr(cur, lrecs - 1, left), lkp));
2092 } else {
2093 /* It's a leaf. Move records. */
2094 union xfs_btree_rec *lrp; /* left record pointer */
2095
2096 lrp = xfs_btree_rec_addr(cur, lrecs, left);
2097 rrp = xfs_btree_rec_addr(cur, 1, right);
2098
2099 xfs_btree_copy_recs(cur, lrp, rrp, 1);
2100 xfs_btree_log_recs(cur, lbp, lrecs, lrecs);
2101
2102 ASSERT(cur->bc_ops->recs_inorder(cur,
2103 xfs_btree_rec_addr(cur, lrecs - 1, left), lrp));
2104 }
2105
2106 xfs_btree_set_numrecs(left, lrecs);
2107 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2108
2109 xfs_btree_set_numrecs(right, rrecs);
2110 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2111
2112 /*
2113 * Slide the contents of right down one entry.
2114 */
2115 XFS_BTREE_STATS_ADD(cur, moves, rrecs - 1);
2116 if (level > 0) {
2117 /* It's a nonleaf. operate on keys and ptrs */
2118#ifdef DEBUG
2119 int i; /* loop index */
2120
2121 for (i = 0; i < rrecs; i++) {
2122 error = xfs_btree_check_ptr(cur, rpp, i + 1, level);
2123 if (error)
2124 goto error0;
2125 }
2126#endif
2127 xfs_btree_shift_keys(cur,
2128 xfs_btree_key_addr(cur, 2, right),
2129 -1, rrecs);
2130 xfs_btree_shift_ptrs(cur,
2131 xfs_btree_ptr_addr(cur, 2, right),
2132 -1, rrecs);
2133
2134 xfs_btree_log_keys(cur, rbp, 1, rrecs);
2135 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2136 } else {
2137 /* It's a leaf. operate on records */
2138 xfs_btree_shift_recs(cur,
2139 xfs_btree_rec_addr(cur, 2, right),
2140 -1, rrecs);
2141 xfs_btree_log_recs(cur, rbp, 1, rrecs);
2142
2143 /*
2144 * If it's the first record in the block, we'll need a key
2145 * structure to pass up to the next level (updkey).
2146 */
2147 cur->bc_ops->init_key_from_rec(&key,
2148 xfs_btree_rec_addr(cur, 1, right));
2149 rkp = &key;
2150 }
2151
2152 /* Update the parent key values of right. */
2153 error = xfs_btree_updkey(cur, rkp, level + 1);
2154 if (error)
2155 goto error0;
2156
2157 /* Slide the cursor value left one. */
2158 cur->bc_ptrs[level]--;
2159
2160 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2161 *stat = 1;
2162 return 0;
2163
2164out0:
2165 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2166 *stat = 0;
2167 return 0;
2168
2169error0:
2170 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2171 return error;
2172}
2173
2174/*
2175 * Move 1 record right from cur/level if possible.
2176 * Update cur to reflect the new path.
2177 */
2178STATIC int /* error */
2179xfs_btree_rshift(
2180 struct xfs_btree_cur *cur,
2181 int level,
2182 int *stat) /* success/failure */
2183{
2184 union xfs_btree_key key; /* btree key */
2185 struct xfs_buf *lbp; /* left buffer pointer */
2186 struct xfs_btree_block *left; /* left btree block */
2187 struct xfs_buf *rbp; /* right buffer pointer */
2188 struct xfs_btree_block *right; /* right btree block */
2189 struct xfs_btree_cur *tcur; /* temporary btree cursor */
2190 union xfs_btree_ptr rptr; /* right block pointer */
2191 union xfs_btree_key *rkp; /* right btree key */
2192 int rrecs; /* right record count */
2193 int lrecs; /* left record count */
2194 int error; /* error return value */
2195 int i; /* loop counter */
2196
2197 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2198 XFS_BTREE_TRACE_ARGI(cur, level);
2199
2200 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2201 (level == cur->bc_nlevels - 1))
2202 goto out0;
2203
2204 /* Set up variables for this block as "left". */
2205 left = xfs_btree_get_block(cur, level, &lbp);
2206
2207#ifdef DEBUG
2208 error = xfs_btree_check_block(cur, left, level, lbp);
2209 if (error)
2210 goto error0;
2211#endif
2212
2213 /* If we've got no right sibling then we can't shift an entry right. */
2214 xfs_btree_get_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2215 if (xfs_btree_ptr_is_null(cur, &rptr))
2216 goto out0;
2217
2218 /*
2219 * If the cursor entry is the one that would be moved, don't
2220 * do it... it's too complicated.
2221 */
2222 lrecs = xfs_btree_get_numrecs(left);
2223 if (cur->bc_ptrs[level] >= lrecs)
2224 goto out0;
2225
2226 /* Set up the right neighbor as "right". */
2227 error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
2228 if (error)
2229 goto error0;
2230
2231 /* If it's full, it can't take another entry. */
2232 rrecs = xfs_btree_get_numrecs(right);
2233 if (rrecs == cur->bc_ops->get_maxrecs(cur, level))
2234 goto out0;
2235
2236 XFS_BTREE_STATS_INC(cur, rshift);
2237 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2238
2239 /*
2240 * Make a hole at the start of the right neighbor block, then
2241 * copy the last left block entry to the hole.
2242 */
2243 if (level > 0) {
2244 /* It's a nonleaf. make a hole in the keys and ptrs */
2245 union xfs_btree_key *lkp;
2246 union xfs_btree_ptr *lpp;
2247 union xfs_btree_ptr *rpp;
2248
2249 lkp = xfs_btree_key_addr(cur, lrecs, left);
2250 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2251 rkp = xfs_btree_key_addr(cur, 1, right);
2252 rpp = xfs_btree_ptr_addr(cur, 1, right);
2253
2254#ifdef DEBUG
2255 for (i = rrecs - 1; i >= 0; i--) {
2256 error = xfs_btree_check_ptr(cur, rpp, i, level);
2257 if (error)
2258 goto error0;
2259 }
2260#endif
2261
2262 xfs_btree_shift_keys(cur, rkp, 1, rrecs);
2263 xfs_btree_shift_ptrs(cur, rpp, 1, rrecs);
2264
2265#ifdef DEBUG
2266 error = xfs_btree_check_ptr(cur, lpp, 0, level);
2267 if (error)
2268 goto error0;
2269#endif
2270
2271 /* Now put the new data in, and log it. */
2272 xfs_btree_copy_keys(cur, rkp, lkp, 1);
2273 xfs_btree_copy_ptrs(cur, rpp, lpp, 1);
2274
2275 xfs_btree_log_keys(cur, rbp, 1, rrecs + 1);
2276 xfs_btree_log_ptrs(cur, rbp, 1, rrecs + 1);
2277
2278 ASSERT(cur->bc_ops->keys_inorder(cur, rkp,
2279 xfs_btree_key_addr(cur, 2, right)));
2280 } else {
2281 /* It's a leaf. make a hole in the records */
2282 union xfs_btree_rec *lrp;
2283 union xfs_btree_rec *rrp;
2284
2285 lrp = xfs_btree_rec_addr(cur, lrecs, left);
2286 rrp = xfs_btree_rec_addr(cur, 1, right);
2287
2288 xfs_btree_shift_recs(cur, rrp, 1, rrecs);
2289
2290 /* Now put the new data in, and log it. */
2291 xfs_btree_copy_recs(cur, rrp, lrp, 1);
2292 xfs_btree_log_recs(cur, rbp, 1, rrecs + 1);
2293
2294 cur->bc_ops->init_key_from_rec(&key, rrp);
2295 rkp = &key;
2296
2297 ASSERT(cur->bc_ops->recs_inorder(cur, rrp,
2298 xfs_btree_rec_addr(cur, 2, right)));
2299 }
2300
2301 /*
2302 * Decrement and log left's numrecs, bump and log right's numrecs.
2303 */
2304 xfs_btree_set_numrecs(left, --lrecs);
2305 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2306
2307 xfs_btree_set_numrecs(right, ++rrecs);
2308 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2309
2310 /*
2311 * Using a temporary cursor, update the parent key values of the
2312 * block on the right.
2313 */
2314 error = xfs_btree_dup_cursor(cur, &tcur);
2315 if (error)
2316 goto error0;
2317 i = xfs_btree_lastrec(tcur, level);
2318 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
2319
2320 error = xfs_btree_increment(tcur, level, &i);
2321 if (error)
2322 goto error1;
2323
2324 error = xfs_btree_updkey(tcur, rkp, level + 1);
2325 if (error)
2326 goto error1;
2327
2328 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
2329
2330 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2331 *stat = 1;
2332 return 0;
2333
2334out0:
2335 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2336 *stat = 0;
2337 return 0;
2338
2339error0:
2340 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2341 return error;
2342
2343error1:
2344 XFS_BTREE_TRACE_CURSOR(tcur, XBT_ERROR);
2345 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
2346 return error;
2347}
2348
2349/*
2350 * Split cur/level block in half.
2351 * Return new block number and the key to its first
2352 * record (to be inserted into parent).
2353 */
2354STATIC int /* error */
2355__xfs_btree_split(
2356 struct xfs_btree_cur *cur,
2357 int level,
2358 union xfs_btree_ptr *ptrp,
2359 union xfs_btree_key *key,
2360 struct xfs_btree_cur **curp,
2361 int *stat) /* success/failure */
2362{
2363 union xfs_btree_ptr lptr; /* left sibling block ptr */
2364 struct xfs_buf *lbp; /* left buffer pointer */
2365 struct xfs_btree_block *left; /* left btree block */
2366 union xfs_btree_ptr rptr; /* right sibling block ptr */
2367 struct xfs_buf *rbp; /* right buffer pointer */
2368 struct xfs_btree_block *right; /* right btree block */
2369 union xfs_btree_ptr rrptr; /* right-right sibling ptr */
2370 struct xfs_buf *rrbp; /* right-right buffer pointer */
2371 struct xfs_btree_block *rrblock; /* right-right btree block */
2372 int lrecs;
2373 int rrecs;
2374 int src_index;
2375 int error; /* error return value */
2376#ifdef DEBUG
2377 int i;
2378#endif
2379
2380 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2381 XFS_BTREE_TRACE_ARGIPK(cur, level, *ptrp, key);
2382
2383 XFS_BTREE_STATS_INC(cur, split);
2384
2385 /* Set up left block (current one). */
2386 left = xfs_btree_get_block(cur, level, &lbp);
2387
2388#ifdef DEBUG
2389 error = xfs_btree_check_block(cur, left, level, lbp);
2390 if (error)
2391 goto error0;
2392#endif
2393
2394 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2395
2396 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2397 error = cur->bc_ops->alloc_block(cur, &lptr, &rptr, stat);
2398 if (error)
2399 goto error0;
2400 if (*stat == 0)
2401 goto out0;
2402 XFS_BTREE_STATS_INC(cur, alloc);
2403
2404 /* Set up the new block as "right". */
2405 error = xfs_btree_get_buf_block(cur, &rptr, 0, &right, &rbp);
2406 if (error)
2407 goto error0;
2408
2409 /* Fill in the btree header for the new right block. */
2410 xfs_btree_init_block_cur(cur, rbp, xfs_btree_get_level(left), 0);
2411
2412 /*
2413 * Split the entries between the old and the new block evenly.
2414 * Make sure that if there's an odd number of entries now, that
2415 * each new block will have the same number of entries.
2416 */
2417 lrecs = xfs_btree_get_numrecs(left);
2418 rrecs = lrecs / 2;
2419 if ((lrecs & 1) && cur->bc_ptrs[level] <= rrecs + 1)
2420 rrecs++;
2421 src_index = (lrecs - rrecs + 1);
2422
2423 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2424
2425 /*
2426 * Copy btree block entries from the left block over to the
2427 * new block, the right. Update the right block and log the
2428 * changes.
2429 */
2430 if (level > 0) {
2431 /* It's a non-leaf. Move keys and pointers. */
2432 union xfs_btree_key *lkp; /* left btree key */
2433 union xfs_btree_ptr *lpp; /* left address pointer */
2434 union xfs_btree_key *rkp; /* right btree key */
2435 union xfs_btree_ptr *rpp; /* right address pointer */
2436
2437 lkp = xfs_btree_key_addr(cur, src_index, left);
2438 lpp = xfs_btree_ptr_addr(cur, src_index, left);
2439 rkp = xfs_btree_key_addr(cur, 1, right);
2440 rpp = xfs_btree_ptr_addr(cur, 1, right);
2441
2442#ifdef DEBUG
2443 for (i = src_index; i < rrecs; i++) {
2444 error = xfs_btree_check_ptr(cur, lpp, i, level);
2445 if (error)
2446 goto error0;
2447 }
2448#endif
2449
2450 xfs_btree_copy_keys(cur, rkp, lkp, rrecs);
2451 xfs_btree_copy_ptrs(cur, rpp, lpp, rrecs);
2452
2453 xfs_btree_log_keys(cur, rbp, 1, rrecs);
2454 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2455
2456 /* Grab the keys to the entries moved to the right block */
2457 xfs_btree_copy_keys(cur, key, rkp, 1);
2458 } else {
2459 /* It's a leaf. Move records. */
2460 union xfs_btree_rec *lrp; /* left record pointer */
2461 union xfs_btree_rec *rrp; /* right record pointer */
2462
2463 lrp = xfs_btree_rec_addr(cur, src_index, left);
2464 rrp = xfs_btree_rec_addr(cur, 1, right);
2465
2466 xfs_btree_copy_recs(cur, rrp, lrp, rrecs);
2467 xfs_btree_log_recs(cur, rbp, 1, rrecs);
2468
2469 cur->bc_ops->init_key_from_rec(key,
2470 xfs_btree_rec_addr(cur, 1, right));
2471 }
2472
2473
2474 /*
2475 * Find the left block number by looking in the buffer.
2476 * Adjust numrecs, sibling pointers.
2477 */
2478 xfs_btree_get_sibling(cur, left, &rrptr, XFS_BB_RIGHTSIB);
2479 xfs_btree_set_sibling(cur, right, &rrptr, XFS_BB_RIGHTSIB);
2480 xfs_btree_set_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2481 xfs_btree_set_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2482
2483 lrecs -= rrecs;
2484 xfs_btree_set_numrecs(left, lrecs);
2485 xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs);
2486
2487 xfs_btree_log_block(cur, rbp, XFS_BB_ALL_BITS);
2488 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
2489
2490 /*
2491 * If there's a block to the new block's right, make that block
2492 * point back to right instead of to left.
2493 */
2494 if (!xfs_btree_ptr_is_null(cur, &rrptr)) {
2495 error = xfs_btree_read_buf_block(cur, &rrptr,
2496 0, &rrblock, &rrbp);
2497 if (error)
2498 goto error0;
2499 xfs_btree_set_sibling(cur, rrblock, &rptr, XFS_BB_LEFTSIB);
2500 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
2501 }
2502 /*
2503 * If the cursor is really in the right block, move it there.
2504 * If it's just pointing past the last entry in left, then we'll
2505 * insert there, so don't change anything in that case.
2506 */
2507 if (cur->bc_ptrs[level] > lrecs + 1) {
2508 xfs_btree_setbuf(cur, level, rbp);
2509 cur->bc_ptrs[level] -= lrecs;
2510 }
2511 /*
2512 * If there are more levels, we'll need another cursor which refers
2513 * the right block, no matter where this cursor was.
2514 */
2515 if (level + 1 < cur->bc_nlevels) {
2516 error = xfs_btree_dup_cursor(cur, curp);
2517 if (error)
2518 goto error0;
2519 (*curp)->bc_ptrs[level + 1]++;
2520 }
2521 *ptrp = rptr;
2522 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2523 *stat = 1;
2524 return 0;
2525out0:
2526 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2527 *stat = 0;
2528 return 0;
2529
2530error0:
2531 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2532 return error;
2533}
2534
2535struct xfs_btree_split_args {
2536 struct xfs_btree_cur *cur;
2537 int level;
2538 union xfs_btree_ptr *ptrp;
2539 union xfs_btree_key *key;
2540 struct xfs_btree_cur **curp;
2541 int *stat; /* success/failure */
2542 int result;
2543 bool kswapd; /* allocation in kswapd context */
2544 struct completion *done;
2545 struct work_struct work;
2546};
2547
2548/*
2549 * Stack switching interfaces for allocation
2550 */
2551static void
2552xfs_btree_split_worker(
2553 struct work_struct *work)
2554{
2555 struct xfs_btree_split_args *args = container_of(work,
2556 struct xfs_btree_split_args, work);
2557 unsigned long pflags;
2558 unsigned long new_pflags = PF_FSTRANS;
2559
2560 /*
2561 * we are in a transaction context here, but may also be doing work
2562 * in kswapd context, and hence we may need to inherit that state
2563 * temporarily to ensure that we don't block waiting for memory reclaim
2564 * in any way.
2565 */
2566 if (args->kswapd)
2567 new_pflags |= PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD;
2568
2569 current_set_flags_nested(&pflags, new_pflags);
2570
2571 args->result = __xfs_btree_split(args->cur, args->level, args->ptrp,
2572 args->key, args->curp, args->stat);
2573 complete(args->done);
2574
2575 current_restore_flags_nested(&pflags, new_pflags);
2576}
2577
2578/*
2579 * BMBT split requests often come in with little stack to work on. Push
2580 * them off to a worker thread so there is lots of stack to use. For the other
2581 * btree types, just call directly to avoid the context switch overhead here.
2582 */
2583STATIC int /* error */
2584xfs_btree_split(
2585 struct xfs_btree_cur *cur,
2586 int level,
2587 union xfs_btree_ptr *ptrp,
2588 union xfs_btree_key *key,
2589 struct xfs_btree_cur **curp,
2590 int *stat) /* success/failure */
2591{
2592 struct xfs_btree_split_args args;
2593 DECLARE_COMPLETION_ONSTACK(done);
2594
2595 if (cur->bc_btnum != XFS_BTNUM_BMAP)
2596 return __xfs_btree_split(cur, level, ptrp, key, curp, stat);
2597
2598 args.cur = cur;
2599 args.level = level;
2600 args.ptrp = ptrp;
2601 args.key = key;
2602 args.curp = curp;
2603 args.stat = stat;
2604 args.done = &done;
2605 args.kswapd = current_is_kswapd();
2606 INIT_WORK_ONSTACK(&args.work, xfs_btree_split_worker);
2607 queue_work(xfs_alloc_wq, &args.work);
2608 wait_for_completion(&done);
2609 destroy_work_on_stack(&args.work);
2610 return args.result;
2611}
2612
2613
2614/*
2615 * Copy the old inode root contents into a real block and make the
2616 * broot point to it.
2617 */
2618int /* error */
2619xfs_btree_new_iroot(
2620 struct xfs_btree_cur *cur, /* btree cursor */
2621 int *logflags, /* logging flags for inode */
2622 int *stat) /* return status - 0 fail */
2623{
2624 struct xfs_buf *cbp; /* buffer for cblock */
2625 struct xfs_btree_block *block; /* btree block */
2626 struct xfs_btree_block *cblock; /* child btree block */
2627 union xfs_btree_key *ckp; /* child key pointer */
2628 union xfs_btree_ptr *cpp; /* child ptr pointer */
2629 union xfs_btree_key *kp; /* pointer to btree key */
2630 union xfs_btree_ptr *pp; /* pointer to block addr */
2631 union xfs_btree_ptr nptr; /* new block addr */
2632 int level; /* btree level */
2633 int error; /* error return code */
2634#ifdef DEBUG
2635 int i; /* loop counter */
2636#endif
2637
2638 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2639 XFS_BTREE_STATS_INC(cur, newroot);
2640
2641 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
2642
2643 level = cur->bc_nlevels - 1;
2644
2645 block = xfs_btree_get_iroot(cur);
2646 pp = xfs_btree_ptr_addr(cur, 1, block);
2647
2648 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2649 error = cur->bc_ops->alloc_block(cur, pp, &nptr, stat);
2650 if (error)
2651 goto error0;
2652 if (*stat == 0) {
2653 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2654 return 0;
2655 }
2656 XFS_BTREE_STATS_INC(cur, alloc);
2657
2658 /* Copy the root into a real block. */
2659 error = xfs_btree_get_buf_block(cur, &nptr, 0, &cblock, &cbp);
2660 if (error)
2661 goto error0;
2662
2663 /*
2664 * we can't just memcpy() the root in for CRC enabled btree blocks.
2665 * In that case have to also ensure the blkno remains correct
2666 */
2667 memcpy(cblock, block, xfs_btree_block_len(cur));
2668 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) {
2669 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
2670 cblock->bb_u.l.bb_blkno = cpu_to_be64(cbp->b_bn);
2671 else
2672 cblock->bb_u.s.bb_blkno = cpu_to_be64(cbp->b_bn);
2673 }
2674
2675 be16_add_cpu(&block->bb_level, 1);
2676 xfs_btree_set_numrecs(block, 1);
2677 cur->bc_nlevels++;
2678 cur->bc_ptrs[level + 1] = 1;
2679
2680 kp = xfs_btree_key_addr(cur, 1, block);
2681 ckp = xfs_btree_key_addr(cur, 1, cblock);
2682 xfs_btree_copy_keys(cur, ckp, kp, xfs_btree_get_numrecs(cblock));
2683
2684 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
2685#ifdef DEBUG
2686 for (i = 0; i < be16_to_cpu(cblock->bb_numrecs); i++) {
2687 error = xfs_btree_check_ptr(cur, pp, i, level);
2688 if (error)
2689 goto error0;
2690 }
2691#endif
2692 xfs_btree_copy_ptrs(cur, cpp, pp, xfs_btree_get_numrecs(cblock));
2693
2694#ifdef DEBUG
2695 error = xfs_btree_check_ptr(cur, &nptr, 0, level);
2696 if (error)
2697 goto error0;
2698#endif
2699 xfs_btree_copy_ptrs(cur, pp, &nptr, 1);
2700
2701 xfs_iroot_realloc(cur->bc_private.b.ip,
2702 1 - xfs_btree_get_numrecs(cblock),
2703 cur->bc_private.b.whichfork);
2704
2705 xfs_btree_setbuf(cur, level, cbp);
2706
2707 /*
2708 * Do all this logging at the end so that
2709 * the root is at the right level.
2710 */
2711 xfs_btree_log_block(cur, cbp, XFS_BB_ALL_BITS);
2712 xfs_btree_log_keys(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
2713 xfs_btree_log_ptrs(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
2714
2715 *logflags |=
2716 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork);
2717 *stat = 1;
2718 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2719 return 0;
2720error0:
2721 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2722 return error;
2723}
2724
2725/*
2726 * Allocate a new root block, fill it in.
2727 */
2728STATIC int /* error */
2729xfs_btree_new_root(
2730 struct xfs_btree_cur *cur, /* btree cursor */
2731 int *stat) /* success/failure */
2732{
2733 struct xfs_btree_block *block; /* one half of the old root block */
2734 struct xfs_buf *bp; /* buffer containing block */
2735 int error; /* error return value */
2736 struct xfs_buf *lbp; /* left buffer pointer */
2737 struct xfs_btree_block *left; /* left btree block */
2738 struct xfs_buf *nbp; /* new (root) buffer */
2739 struct xfs_btree_block *new; /* new (root) btree block */
2740 int nptr; /* new value for key index, 1 or 2 */
2741 struct xfs_buf *rbp; /* right buffer pointer */
2742 struct xfs_btree_block *right; /* right btree block */
2743 union xfs_btree_ptr rptr;
2744 union xfs_btree_ptr lptr;
2745
2746 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2747 XFS_BTREE_STATS_INC(cur, newroot);
2748
2749 /* initialise our start point from the cursor */
2750 cur->bc_ops->init_ptr_from_cur(cur, &rptr);
2751
2752 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2753 error = cur->bc_ops->alloc_block(cur, &rptr, &lptr, stat);
2754 if (error)
2755 goto error0;
2756 if (*stat == 0)
2757 goto out0;
2758 XFS_BTREE_STATS_INC(cur, alloc);
2759
2760 /* Set up the new block. */
2761 error = xfs_btree_get_buf_block(cur, &lptr, 0, &new, &nbp);
2762 if (error)
2763 goto error0;
2764
2765 /* Set the root in the holding structure increasing the level by 1. */
2766 cur->bc_ops->set_root(cur, &lptr, 1);
2767
2768 /*
2769 * At the previous root level there are now two blocks: the old root,
2770 * and the new block generated when it was split. We don't know which
2771 * one the cursor is pointing at, so we set up variables "left" and
2772 * "right" for each case.
2773 */
2774 block = xfs_btree_get_block(cur, cur->bc_nlevels - 1, &bp);
2775
2776#ifdef DEBUG
2777 error = xfs_btree_check_block(cur, block, cur->bc_nlevels - 1, bp);
2778 if (error)
2779 goto error0;
2780#endif
2781
2782 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
2783 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
2784 /* Our block is left, pick up the right block. */
2785 lbp = bp;
2786 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2787 left = block;
2788 error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
2789 if (error)
2790 goto error0;
2791 bp = rbp;
2792 nptr = 1;
2793 } else {
2794 /* Our block is right, pick up the left block. */
2795 rbp = bp;
2796 xfs_btree_buf_to_ptr(cur, rbp, &rptr);
2797 right = block;
2798 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2799 error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
2800 if (error)
2801 goto error0;
2802 bp = lbp;
2803 nptr = 2;
2804 }
2805 /* Fill in the new block's btree header and log it. */
2806 xfs_btree_init_block_cur(cur, nbp, cur->bc_nlevels, 2);
2807 xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS);
2808 ASSERT(!xfs_btree_ptr_is_null(cur, &lptr) &&
2809 !xfs_btree_ptr_is_null(cur, &rptr));
2810
2811 /* Fill in the key data in the new root. */
2812 if (xfs_btree_get_level(left) > 0) {
2813 xfs_btree_copy_keys(cur,
2814 xfs_btree_key_addr(cur, 1, new),
2815 xfs_btree_key_addr(cur, 1, left), 1);
2816 xfs_btree_copy_keys(cur,
2817 xfs_btree_key_addr(cur, 2, new),
2818 xfs_btree_key_addr(cur, 1, right), 1);
2819 } else {
2820 cur->bc_ops->init_key_from_rec(
2821 xfs_btree_key_addr(cur, 1, new),
2822 xfs_btree_rec_addr(cur, 1, left));
2823 cur->bc_ops->init_key_from_rec(
2824 xfs_btree_key_addr(cur, 2, new),
2825 xfs_btree_rec_addr(cur, 1, right));
2826 }
2827 xfs_btree_log_keys(cur, nbp, 1, 2);
2828
2829 /* Fill in the pointer data in the new root. */
2830 xfs_btree_copy_ptrs(cur,
2831 xfs_btree_ptr_addr(cur, 1, new), &lptr, 1);
2832 xfs_btree_copy_ptrs(cur,
2833 xfs_btree_ptr_addr(cur, 2, new), &rptr, 1);
2834 xfs_btree_log_ptrs(cur, nbp, 1, 2);
2835
2836 /* Fix up the cursor. */
2837 xfs_btree_setbuf(cur, cur->bc_nlevels, nbp);
2838 cur->bc_ptrs[cur->bc_nlevels] = nptr;
2839 cur->bc_nlevels++;
2840 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2841 *stat = 1;
2842 return 0;
2843error0:
2844 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2845 return error;
2846out0:
2847 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2848 *stat = 0;
2849 return 0;
2850}
2851
2852STATIC int
2853xfs_btree_make_block_unfull(
2854 struct xfs_btree_cur *cur, /* btree cursor */
2855 int level, /* btree level */
2856 int numrecs,/* # of recs in block */
2857 int *oindex,/* old tree index */
2858 int *index, /* new tree index */
2859 union xfs_btree_ptr *nptr, /* new btree ptr */
2860 struct xfs_btree_cur **ncur, /* new btree cursor */
2861 union xfs_btree_rec *nrec, /* new record */
2862 int *stat)
2863{
2864 union xfs_btree_key key; /* new btree key value */
2865 int error = 0;
2866
2867 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2868 level == cur->bc_nlevels - 1) {
2869 struct xfs_inode *ip = cur->bc_private.b.ip;
2870
2871 if (numrecs < cur->bc_ops->get_dmaxrecs(cur, level)) {
2872 /* A root block that can be made bigger. */
2873 xfs_iroot_realloc(ip, 1, cur->bc_private.b.whichfork);
2874 } else {
2875 /* A root block that needs replacing */
2876 int logflags = 0;
2877
2878 error = xfs_btree_new_iroot(cur, &logflags, stat);
2879 if (error || *stat == 0)
2880 return error;
2881
2882 xfs_trans_log_inode(cur->bc_tp, ip, logflags);
2883 }
2884
2885 return 0;
2886 }
2887
2888 /* First, try shifting an entry to the right neighbor. */
2889 error = xfs_btree_rshift(cur, level, stat);
2890 if (error || *stat)
2891 return error;
2892
2893 /* Next, try shifting an entry to the left neighbor. */
2894 error = xfs_btree_lshift(cur, level, stat);
2895 if (error)
2896 return error;
2897
2898 if (*stat) {
2899 *oindex = *index = cur->bc_ptrs[level];
2900 return 0;
2901 }
2902
2903 /*
2904 * Next, try splitting the current block in half.
2905 *
2906 * If this works we have to re-set our variables because we
2907 * could be in a different block now.
2908 */
2909 error = xfs_btree_split(cur, level, nptr, &key, ncur, stat);
2910 if (error || *stat == 0)
2911 return error;
2912
2913
2914 *index = cur->bc_ptrs[level];
2915 cur->bc_ops->init_rec_from_key(&key, nrec);
2916 return 0;
2917}
2918
2919/*
2920 * Insert one record/level. Return information to the caller
2921 * allowing the next level up to proceed if necessary.
2922 */
2923STATIC int
2924xfs_btree_insrec(
2925 struct xfs_btree_cur *cur, /* btree cursor */
2926 int level, /* level to insert record at */
2927 union xfs_btree_ptr *ptrp, /* i/o: block number inserted */
2928 union xfs_btree_rec *recp, /* i/o: record data inserted */
2929 struct xfs_btree_cur **curp, /* output: new cursor replacing cur */
2930 int *stat) /* success/failure */
2931{
2932 struct xfs_btree_block *block; /* btree block */
2933 struct xfs_buf *bp; /* buffer for block */
2934 union xfs_btree_key key; /* btree key */
2935 union xfs_btree_ptr nptr; /* new block ptr */
2936 struct xfs_btree_cur *ncur; /* new btree cursor */
2937 union xfs_btree_rec nrec; /* new record count */
2938 int optr; /* old key/record index */
2939 int ptr; /* key/record index */
2940 int numrecs;/* number of records */
2941 int error; /* error return value */
2942#ifdef DEBUG
2943 int i;
2944#endif
2945
2946 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2947 XFS_BTREE_TRACE_ARGIPR(cur, level, *ptrp, recp);
2948
2949 ncur = NULL;
2950
2951 /*
2952 * If we have an external root pointer, and we've made it to the
2953 * root level, allocate a new root block and we're done.
2954 */
2955 if (!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2956 (level >= cur->bc_nlevels)) {
2957 error = xfs_btree_new_root(cur, stat);
2958 xfs_btree_set_ptr_null(cur, ptrp);
2959
2960 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2961 return error;
2962 }
2963
2964 /* If we're off the left edge, return failure. */
2965 ptr = cur->bc_ptrs[level];
2966 if (ptr == 0) {
2967 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2968 *stat = 0;
2969 return 0;
2970 }
2971
2972 /* Make a key out of the record data to be inserted, and save it. */
2973 cur->bc_ops->init_key_from_rec(&key, recp);
2974
2975 optr = ptr;
2976
2977 XFS_BTREE_STATS_INC(cur, insrec);
2978
2979 /* Get pointers to the btree buffer and block. */
2980 block = xfs_btree_get_block(cur, level, &bp);
2981 numrecs = xfs_btree_get_numrecs(block);
2982
2983#ifdef DEBUG
2984 error = xfs_btree_check_block(cur, block, level, bp);
2985 if (error)
2986 goto error0;
2987
2988 /* Check that the new entry is being inserted in the right place. */
2989 if (ptr <= numrecs) {
2990 if (level == 0) {
2991 ASSERT(cur->bc_ops->recs_inorder(cur, recp,
2992 xfs_btree_rec_addr(cur, ptr, block)));
2993 } else {
2994 ASSERT(cur->bc_ops->keys_inorder(cur, &key,
2995 xfs_btree_key_addr(cur, ptr, block)));
2996 }
2997 }
2998#endif
2999
3000 /*
3001 * If the block is full, we can't insert the new entry until we
3002 * make the block un-full.
3003 */
3004 xfs_btree_set_ptr_null(cur, &nptr);
3005 if (numrecs == cur->bc_ops->get_maxrecs(cur, level)) {
3006 error = xfs_btree_make_block_unfull(cur, level, numrecs,
3007 &optr, &ptr, &nptr, &ncur, &nrec, stat);
3008 if (error || *stat == 0)
3009 goto error0;
3010 }
3011
3012 /*
3013 * The current block may have changed if the block was
3014 * previously full and we have just made space in it.
3015 */
3016 block = xfs_btree_get_block(cur, level, &bp);
3017 numrecs = xfs_btree_get_numrecs(block);
3018
3019#ifdef DEBUG
3020 error = xfs_btree_check_block(cur, block, level, bp);
3021 if (error)
3022 return error;
3023#endif
3024
3025 /*
3026 * At this point we know there's room for our new entry in the block
3027 * we're pointing at.
3028 */
3029 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr + 1);
3030
3031 if (level > 0) {
3032 /* It's a nonleaf. make a hole in the keys and ptrs */
3033 union xfs_btree_key *kp;
3034 union xfs_btree_ptr *pp;
3035
3036 kp = xfs_btree_key_addr(cur, ptr, block);
3037 pp = xfs_btree_ptr_addr(cur, ptr, block);
3038
3039#ifdef DEBUG
3040 for (i = numrecs - ptr; i >= 0; i--) {
3041 error = xfs_btree_check_ptr(cur, pp, i, level);
3042 if (error)
3043 return error;
3044 }
3045#endif
3046
3047 xfs_btree_shift_keys(cur, kp, 1, numrecs - ptr + 1);
3048 xfs_btree_shift_ptrs(cur, pp, 1, numrecs - ptr + 1);
3049
3050#ifdef DEBUG
3051 error = xfs_btree_check_ptr(cur, ptrp, 0, level);
3052 if (error)
3053 goto error0;
3054#endif
3055
3056 /* Now put the new data in, bump numrecs and log it. */
3057 xfs_btree_copy_keys(cur, kp, &key, 1);
3058 xfs_btree_copy_ptrs(cur, pp, ptrp, 1);
3059 numrecs++;
3060 xfs_btree_set_numrecs(block, numrecs);
3061 xfs_btree_log_ptrs(cur, bp, ptr, numrecs);
3062 xfs_btree_log_keys(cur, bp, ptr, numrecs);
3063#ifdef DEBUG
3064 if (ptr < numrecs) {
3065 ASSERT(cur->bc_ops->keys_inorder(cur, kp,
3066 xfs_btree_key_addr(cur, ptr + 1, block)));
3067 }
3068#endif
3069 } else {
3070 /* It's a leaf. make a hole in the records */
3071 union xfs_btree_rec *rp;
3072
3073 rp = xfs_btree_rec_addr(cur, ptr, block);
3074
3075 xfs_btree_shift_recs(cur, rp, 1, numrecs - ptr + 1);
3076
3077 /* Now put the new data in, bump numrecs and log it. */
3078 xfs_btree_copy_recs(cur, rp, recp, 1);
3079 xfs_btree_set_numrecs(block, ++numrecs);
3080 xfs_btree_log_recs(cur, bp, ptr, numrecs);
3081#ifdef DEBUG
3082 if (ptr < numrecs) {
3083 ASSERT(cur->bc_ops->recs_inorder(cur, rp,
3084 xfs_btree_rec_addr(cur, ptr + 1, block)));
3085 }
3086#endif
3087 }
3088
3089 /* Log the new number of records in the btree header. */
3090 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
3091
3092 /* If we inserted at the start of a block, update the parents' keys. */
3093 if (optr == 1) {
3094 error = xfs_btree_updkey(cur, &key, level + 1);
3095 if (error)
3096 goto error0;
3097 }
3098
3099 /*
3100 * If we are tracking the last record in the tree and
3101 * we are at the far right edge of the tree, update it.
3102 */
3103 if (xfs_btree_is_lastrec(cur, block, level)) {
3104 cur->bc_ops->update_lastrec(cur, block, recp,
3105 ptr, LASTREC_INSREC);
3106 }
3107
3108 /*
3109 * Return the new block number, if any.
3110 * If there is one, give back a record value and a cursor too.
3111 */
3112 *ptrp = nptr;
3113 if (!xfs_btree_ptr_is_null(cur, &nptr)) {
3114 *recp = nrec;
3115 *curp = ncur;
3116 }
3117
3118 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3119 *stat = 1;
3120 return 0;
3121
3122error0:
3123 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3124 return error;
3125}
3126
3127/*
3128 * Insert the record at the point referenced by cur.
3129 *
3130 * A multi-level split of the tree on insert will invalidate the original
3131 * cursor. All callers of this function should assume that the cursor is
3132 * no longer valid and revalidate it.
3133 */
3134int
3135xfs_btree_insert(
3136 struct xfs_btree_cur *cur,
3137 int *stat)
3138{
3139 int error; /* error return value */
3140 int i; /* result value, 0 for failure */
3141 int level; /* current level number in btree */
3142 union xfs_btree_ptr nptr; /* new block number (split result) */
3143 struct xfs_btree_cur *ncur; /* new cursor (split result) */
3144 struct xfs_btree_cur *pcur; /* previous level's cursor */
3145 union xfs_btree_rec rec; /* record to insert */
3146
3147 level = 0;
3148 ncur = NULL;
3149 pcur = cur;
3150
3151 xfs_btree_set_ptr_null(cur, &nptr);
3152 cur->bc_ops->init_rec_from_cur(cur, &rec);
3153
3154 /*
3155 * Loop going up the tree, starting at the leaf level.
3156 * Stop when we don't get a split block, that must mean that
3157 * the insert is finished with this level.
3158 */
3159 do {
3160 /*
3161 * Insert nrec/nptr into this level of the tree.
3162 * Note if we fail, nptr will be null.
3163 */
3164 error = xfs_btree_insrec(pcur, level, &nptr, &rec, &ncur, &i);
3165 if (error) {
3166 if (pcur != cur)
3167 xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR);
3168 goto error0;
3169 }
3170
3171 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
3172 level++;
3173
3174 /*
3175 * See if the cursor we just used is trash.
3176 * Can't trash the caller's cursor, but otherwise we should
3177 * if ncur is a new cursor or we're about to be done.
3178 */
3179 if (pcur != cur &&
3180 (ncur || xfs_btree_ptr_is_null(cur, &nptr))) {
3181 /* Save the state from the cursor before we trash it */
3182 if (cur->bc_ops->update_cursor)
3183 cur->bc_ops->update_cursor(pcur, cur);
3184 cur->bc_nlevels = pcur->bc_nlevels;
3185 xfs_btree_del_cursor(pcur, XFS_BTREE_NOERROR);
3186 }
3187 /* If we got a new cursor, switch to it. */
3188 if (ncur) {
3189 pcur = ncur;
3190 ncur = NULL;
3191 }
3192 } while (!xfs_btree_ptr_is_null(cur, &nptr));
3193
3194 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3195 *stat = i;
3196 return 0;
3197error0:
3198 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3199 return error;
3200}
3201
3202/*
3203 * Try to merge a non-leaf block back into the inode root.
3204 *
3205 * Note: the killroot names comes from the fact that we're effectively
3206 * killing the old root block. But because we can't just delete the
3207 * inode we have to copy the single block it was pointing to into the
3208 * inode.
3209 */
3210STATIC int
3211xfs_btree_kill_iroot(
3212 struct xfs_btree_cur *cur)
3213{
3214 int whichfork = cur->bc_private.b.whichfork;
3215 struct xfs_inode *ip = cur->bc_private.b.ip;
3216 struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork);
3217 struct xfs_btree_block *block;
3218 struct xfs_btree_block *cblock;
3219 union xfs_btree_key *kp;
3220 union xfs_btree_key *ckp;
3221 union xfs_btree_ptr *pp;
3222 union xfs_btree_ptr *cpp;
3223 struct xfs_buf *cbp;
3224 int level;
3225 int index;
3226 int numrecs;
3227 int error;
3228#ifdef DEBUG
3229 union xfs_btree_ptr ptr;
3230 int i;
3231#endif
3232
3233 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3234
3235 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
3236 ASSERT(cur->bc_nlevels > 1);
3237
3238 /*
3239 * Don't deal with the root block needs to be a leaf case.
3240 * We're just going to turn the thing back into extents anyway.
3241 */
3242 level = cur->bc_nlevels - 1;
3243 if (level == 1)
3244 goto out0;
3245
3246 /*
3247 * Give up if the root has multiple children.
3248 */
3249 block = xfs_btree_get_iroot(cur);
3250 if (xfs_btree_get_numrecs(block) != 1)
3251 goto out0;
3252
3253 cblock = xfs_btree_get_block(cur, level - 1, &cbp);
3254 numrecs = xfs_btree_get_numrecs(cblock);
3255
3256 /*
3257 * Only do this if the next level will fit.
3258 * Then the data must be copied up to the inode,
3259 * instead of freeing the root you free the next level.
3260 */
3261 if (numrecs > cur->bc_ops->get_dmaxrecs(cur, level))
3262 goto out0;
3263
3264 XFS_BTREE_STATS_INC(cur, killroot);
3265
3266#ifdef DEBUG
3267 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
3268 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
3269 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
3270 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
3271#endif
3272
3273 index = numrecs - cur->bc_ops->get_maxrecs(cur, level);
3274 if (index) {
3275 xfs_iroot_realloc(cur->bc_private.b.ip, index,
3276 cur->bc_private.b.whichfork);
3277 block = ifp->if_broot;
3278 }
3279
3280 be16_add_cpu(&block->bb_numrecs, index);
3281 ASSERT(block->bb_numrecs == cblock->bb_numrecs);
3282
3283 kp = xfs_btree_key_addr(cur, 1, block);
3284 ckp = xfs_btree_key_addr(cur, 1, cblock);
3285 xfs_btree_copy_keys(cur, kp, ckp, numrecs);
3286
3287 pp = xfs_btree_ptr_addr(cur, 1, block);
3288 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
3289#ifdef DEBUG
3290 for (i = 0; i < numrecs; i++) {
3291 error = xfs_btree_check_ptr(cur, cpp, i, level - 1);
3292 if (error) {
3293 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3294 return error;
3295 }
3296 }
3297#endif
3298 xfs_btree_copy_ptrs(cur, pp, cpp, numrecs);
3299
3300 error = xfs_btree_free_block(cur, cbp);
3301 if (error) {
3302 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3303 return error;
3304 }
3305
3306 cur->bc_bufs[level - 1] = NULL;
3307 be16_add_cpu(&block->bb_level, -1);
3308 xfs_trans_log_inode(cur->bc_tp, ip,
3309 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork));
3310 cur->bc_nlevels--;
3311out0:
3312 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3313 return 0;
3314}
3315
3316/*
3317 * Kill the current root node, and replace it with it's only child node.
3318 */
3319STATIC int
3320xfs_btree_kill_root(
3321 struct xfs_btree_cur *cur,
3322 struct xfs_buf *bp,
3323 int level,
3324 union xfs_btree_ptr *newroot)
3325{
3326 int error;
3327
3328 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3329 XFS_BTREE_STATS_INC(cur, killroot);
3330
3331 /*
3332 * Update the root pointer, decreasing the level by 1 and then
3333 * free the old root.
3334 */
3335 cur->bc_ops->set_root(cur, newroot, -1);
3336
3337 error = xfs_btree_free_block(cur, bp);
3338 if (error) {
3339 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3340 return error;
3341 }
3342
3343 cur->bc_bufs[level] = NULL;
3344 cur->bc_ra[level] = 0;
3345 cur->bc_nlevels--;
3346
3347 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3348 return 0;
3349}
3350
3351STATIC int
3352xfs_btree_dec_cursor(
3353 struct xfs_btree_cur *cur,
3354 int level,
3355 int *stat)
3356{
3357 int error;
3358 int i;
3359
3360 if (level > 0) {
3361 error = xfs_btree_decrement(cur, level, &i);
3362 if (error)
3363 return error;
3364 }
3365
3366 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3367 *stat = 1;
3368 return 0;
3369}
3370
3371/*
3372 * Single level of the btree record deletion routine.
3373 * Delete record pointed to by cur/level.
3374 * Remove the record from its block then rebalance the tree.
3375 * Return 0 for error, 1 for done, 2 to go on to the next level.
3376 */
3377STATIC int /* error */
3378xfs_btree_delrec(
3379 struct xfs_btree_cur *cur, /* btree cursor */
3380 int level, /* level removing record from */
3381 int *stat) /* fail/done/go-on */
3382{
3383 struct xfs_btree_block *block; /* btree block */
3384 union xfs_btree_ptr cptr; /* current block ptr */
3385 struct xfs_buf *bp; /* buffer for block */
3386 int error; /* error return value */
3387 int i; /* loop counter */
3388 union xfs_btree_key key; /* storage for keyp */
3389 union xfs_btree_key *keyp = &key; /* passed to the next level */
3390 union xfs_btree_ptr lptr; /* left sibling block ptr */
3391 struct xfs_buf *lbp; /* left buffer pointer */
3392 struct xfs_btree_block *left; /* left btree block */
3393 int lrecs = 0; /* left record count */
3394 int ptr; /* key/record index */
3395 union xfs_btree_ptr rptr; /* right sibling block ptr */
3396 struct xfs_buf *rbp; /* right buffer pointer */
3397 struct xfs_btree_block *right; /* right btree block */
3398 struct xfs_btree_block *rrblock; /* right-right btree block */
3399 struct xfs_buf *rrbp; /* right-right buffer pointer */
3400 int rrecs = 0; /* right record count */
3401 struct xfs_btree_cur *tcur; /* temporary btree cursor */
3402 int numrecs; /* temporary numrec count */
3403
3404 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3405 XFS_BTREE_TRACE_ARGI(cur, level);
3406
3407 tcur = NULL;
3408
3409 /* Get the index of the entry being deleted, check for nothing there. */
3410 ptr = cur->bc_ptrs[level];
3411 if (ptr == 0) {
3412 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3413 *stat = 0;
3414 return 0;
3415 }
3416
3417 /* Get the buffer & block containing the record or key/ptr. */
3418 block = xfs_btree_get_block(cur, level, &bp);
3419 numrecs = xfs_btree_get_numrecs(block);
3420
3421#ifdef DEBUG
3422 error = xfs_btree_check_block(cur, block, level, bp);
3423 if (error)
3424 goto error0;
3425#endif
3426
3427 /* Fail if we're off the end of the block. */
3428 if (ptr > numrecs) {
3429 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3430 *stat = 0;
3431 return 0;
3432 }
3433
3434 XFS_BTREE_STATS_INC(cur, delrec);
3435 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr);
3436
3437 /* Excise the entries being deleted. */
3438 if (level > 0) {
3439 /* It's a nonleaf. operate on keys and ptrs */
3440 union xfs_btree_key *lkp;
3441 union xfs_btree_ptr *lpp;
3442
3443 lkp = xfs_btree_key_addr(cur, ptr + 1, block);
3444 lpp = xfs_btree_ptr_addr(cur, ptr + 1, block);
3445
3446#ifdef DEBUG
3447 for (i = 0; i < numrecs - ptr; i++) {
3448 error = xfs_btree_check_ptr(cur, lpp, i, level);
3449 if (error)
3450 goto error0;
3451 }
3452#endif
3453
3454 if (ptr < numrecs) {
3455 xfs_btree_shift_keys(cur, lkp, -1, numrecs - ptr);
3456 xfs_btree_shift_ptrs(cur, lpp, -1, numrecs - ptr);
3457 xfs_btree_log_keys(cur, bp, ptr, numrecs - 1);
3458 xfs_btree_log_ptrs(cur, bp, ptr, numrecs - 1);
3459 }
3460
3461 /*
3462 * If it's the first record in the block, we'll need to pass a
3463 * key up to the next level (updkey).
3464 */
3465 if (ptr == 1)
3466 keyp = xfs_btree_key_addr(cur, 1, block);
3467 } else {
3468 /* It's a leaf. operate on records */
3469 if (ptr < numrecs) {
3470 xfs_btree_shift_recs(cur,
3471 xfs_btree_rec_addr(cur, ptr + 1, block),
3472 -1, numrecs - ptr);
3473 xfs_btree_log_recs(cur, bp, ptr, numrecs - 1);
3474 }
3475
3476 /*
3477 * If it's the first record in the block, we'll need a key
3478 * structure to pass up to the next level (updkey).
3479 */
3480 if (ptr == 1) {
3481 cur->bc_ops->init_key_from_rec(&key,
3482 xfs_btree_rec_addr(cur, 1, block));
3483 keyp = &key;
3484 }
3485 }
3486
3487 /*
3488 * Decrement and log the number of entries in the block.
3489 */
3490 xfs_btree_set_numrecs(block, --numrecs);
3491 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
3492
3493 /*
3494 * If we are tracking the last record in the tree and
3495 * we are at the far right edge of the tree, update it.
3496 */
3497 if (xfs_btree_is_lastrec(cur, block, level)) {
3498 cur->bc_ops->update_lastrec(cur, block, NULL,
3499 ptr, LASTREC_DELREC);
3500 }
3501
3502 /*
3503 * We're at the root level. First, shrink the root block in-memory.
3504 * Try to get rid of the next level down. If we can't then there's
3505 * nothing left to do.
3506 */
3507 if (level == cur->bc_nlevels - 1) {
3508 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3509 xfs_iroot_realloc(cur->bc_private.b.ip, -1,
3510 cur->bc_private.b.whichfork);
3511
3512 error = xfs_btree_kill_iroot(cur);
3513 if (error)
3514 goto error0;
3515
3516 error = xfs_btree_dec_cursor(cur, level, stat);
3517 if (error)
3518 goto error0;
3519 *stat = 1;
3520 return 0;
3521 }
3522
3523 /*
3524 * If this is the root level, and there's only one entry left,
3525 * and it's NOT the leaf level, then we can get rid of this
3526 * level.
3527 */
3528 if (numrecs == 1 && level > 0) {
3529 union xfs_btree_ptr *pp;
3530 /*
3531 * pp is still set to the first pointer in the block.
3532 * Make it the new root of the btree.
3533 */
3534 pp = xfs_btree_ptr_addr(cur, 1, block);
3535 error = xfs_btree_kill_root(cur, bp, level, pp);
3536 if (error)
3537 goto error0;
3538 } else if (level > 0) {
3539 error = xfs_btree_dec_cursor(cur, level, stat);
3540 if (error)
3541 goto error0;
3542 }
3543 *stat = 1;
3544 return 0;
3545 }
3546
3547 /*
3548 * If we deleted the leftmost entry in the block, update the
3549 * key values above us in the tree.
3550 */
3551 if (ptr == 1) {
3552 error = xfs_btree_updkey(cur, keyp, level + 1);
3553 if (error)
3554 goto error0;
3555 }
3556
3557 /*
3558 * If the number of records remaining in the block is at least
3559 * the minimum, we're done.
3560 */
3561 if (numrecs >= cur->bc_ops->get_minrecs(cur, level)) {
3562 error = xfs_btree_dec_cursor(cur, level, stat);
3563 if (error)
3564 goto error0;
3565 return 0;
3566 }
3567
3568 /*
3569 * Otherwise, we have to move some records around to keep the
3570 * tree balanced. Look at the left and right sibling blocks to
3571 * see if we can re-balance by moving only one record.
3572 */
3573 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
3574 xfs_btree_get_sibling(cur, block, &lptr, XFS_BB_LEFTSIB);
3575
3576 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3577 /*
3578 * One child of root, need to get a chance to copy its contents
3579 * into the root and delete it. Can't go up to next level,
3580 * there's nothing to delete there.
3581 */
3582 if (xfs_btree_ptr_is_null(cur, &rptr) &&
3583 xfs_btree_ptr_is_null(cur, &lptr) &&
3584 level == cur->bc_nlevels - 2) {
3585 error = xfs_btree_kill_iroot(cur);
3586 if (!error)
3587 error = xfs_btree_dec_cursor(cur, level, stat);
3588 if (error)
3589 goto error0;
3590 return 0;
3591 }
3592 }
3593
3594 ASSERT(!xfs_btree_ptr_is_null(cur, &rptr) ||
3595 !xfs_btree_ptr_is_null(cur, &lptr));
3596
3597 /*
3598 * Duplicate the cursor so our btree manipulations here won't
3599 * disrupt the next level up.
3600 */
3601 error = xfs_btree_dup_cursor(cur, &tcur);
3602 if (error)
3603 goto error0;
3604
3605 /*
3606 * If there's a right sibling, see if it's ok to shift an entry
3607 * out of it.
3608 */
3609 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
3610 /*
3611 * Move the temp cursor to the last entry in the next block.
3612 * Actually any entry but the first would suffice.
3613 */
3614 i = xfs_btree_lastrec(tcur, level);
3615 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
3616
3617 error = xfs_btree_increment(tcur, level, &i);
3618 if (error)
3619 goto error0;
3620 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
3621
3622 i = xfs_btree_lastrec(tcur, level);
3623 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
3624
3625 /* Grab a pointer to the block. */
3626 right = xfs_btree_get_block(tcur, level, &rbp);
3627#ifdef DEBUG
3628 error = xfs_btree_check_block(tcur, right, level, rbp);
3629 if (error)
3630 goto error0;
3631#endif
3632 /* Grab the current block number, for future use. */
3633 xfs_btree_get_sibling(tcur, right, &cptr, XFS_BB_LEFTSIB);
3634
3635 /*
3636 * If right block is full enough so that removing one entry
3637 * won't make it too empty, and left-shifting an entry out
3638 * of right to us works, we're done.
3639 */
3640 if (xfs_btree_get_numrecs(right) - 1 >=
3641 cur->bc_ops->get_minrecs(tcur, level)) {
3642 error = xfs_btree_lshift(tcur, level, &i);
3643 if (error)
3644 goto error0;
3645 if (i) {
3646 ASSERT(xfs_btree_get_numrecs(block) >=
3647 cur->bc_ops->get_minrecs(tcur, level));
3648
3649 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3650 tcur = NULL;
3651
3652 error = xfs_btree_dec_cursor(cur, level, stat);
3653 if (error)
3654 goto error0;
3655 return 0;
3656 }
3657 }
3658
3659 /*
3660 * Otherwise, grab the number of records in right for
3661 * future reference, and fix up the temp cursor to point
3662 * to our block again (last record).
3663 */
3664 rrecs = xfs_btree_get_numrecs(right);
3665 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3666 i = xfs_btree_firstrec(tcur, level);
3667 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
3668
3669 error = xfs_btree_decrement(tcur, level, &i);
3670 if (error)
3671 goto error0;
3672 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
3673 }
3674 }
3675
3676 /*
3677 * If there's a left sibling, see if it's ok to shift an entry
3678 * out of it.
3679 */
3680 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3681 /*
3682 * Move the temp cursor to the first entry in the
3683 * previous block.
3684 */
3685 i = xfs_btree_firstrec(tcur, level);
3686 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
3687
3688 error = xfs_btree_decrement(tcur, level, &i);
3689 if (error)
3690 goto error0;
3691 i = xfs_btree_firstrec(tcur, level);
3692 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
3693
3694 /* Grab a pointer to the block. */
3695 left = xfs_btree_get_block(tcur, level, &lbp);
3696#ifdef DEBUG
3697 error = xfs_btree_check_block(cur, left, level, lbp);
3698 if (error)
3699 goto error0;
3700#endif
3701 /* Grab the current block number, for future use. */
3702 xfs_btree_get_sibling(tcur, left, &cptr, XFS_BB_RIGHTSIB);
3703
3704 /*
3705 * If left block is full enough so that removing one entry
3706 * won't make it too empty, and right-shifting an entry out
3707 * of left to us works, we're done.
3708 */
3709 if (xfs_btree_get_numrecs(left) - 1 >=
3710 cur->bc_ops->get_minrecs(tcur, level)) {
3711 error = xfs_btree_rshift(tcur, level, &i);
3712 if (error)
3713 goto error0;
3714 if (i) {
3715 ASSERT(xfs_btree_get_numrecs(block) >=
3716 cur->bc_ops->get_minrecs(tcur, level));
3717 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3718 tcur = NULL;
3719 if (level == 0)
3720 cur->bc_ptrs[0]++;
3721 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3722 *stat = 1;
3723 return 0;
3724 }
3725 }
3726
3727 /*
3728 * Otherwise, grab the number of records in right for
3729 * future reference.
3730 */
3731 lrecs = xfs_btree_get_numrecs(left);
3732 }
3733
3734 /* Delete the temp cursor, we're done with it. */
3735 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3736 tcur = NULL;
3737
3738 /* If here, we need to do a join to keep the tree balanced. */
3739 ASSERT(!xfs_btree_ptr_is_null(cur, &cptr));
3740
3741 if (!xfs_btree_ptr_is_null(cur, &lptr) &&
3742 lrecs + xfs_btree_get_numrecs(block) <=
3743 cur->bc_ops->get_maxrecs(cur, level)) {
3744 /*
3745 * Set "right" to be the starting block,
3746 * "left" to be the left neighbor.
3747 */
3748 rptr = cptr;
3749 right = block;
3750 rbp = bp;
3751 error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
3752 if (error)
3753 goto error0;
3754
3755 /*
3756 * If that won't work, see if we can join with the right neighbor block.
3757 */
3758 } else if (!xfs_btree_ptr_is_null(cur, &rptr) &&
3759 rrecs + xfs_btree_get_numrecs(block) <=
3760 cur->bc_ops->get_maxrecs(cur, level)) {
3761 /*
3762 * Set "left" to be the starting block,
3763 * "right" to be the right neighbor.
3764 */
3765 lptr = cptr;
3766 left = block;
3767 lbp = bp;
3768 error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
3769 if (error)
3770 goto error0;
3771
3772 /*
3773 * Otherwise, we can't fix the imbalance.
3774 * Just return. This is probably a logic error, but it's not fatal.
3775 */
3776 } else {
3777 error = xfs_btree_dec_cursor(cur, level, stat);
3778 if (error)
3779 goto error0;
3780 return 0;
3781 }
3782
3783 rrecs = xfs_btree_get_numrecs(right);
3784 lrecs = xfs_btree_get_numrecs(left);
3785
3786 /*
3787 * We're now going to join "left" and "right" by moving all the stuff
3788 * in "right" to "left" and deleting "right".
3789 */
3790 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
3791 if (level > 0) {
3792 /* It's a non-leaf. Move keys and pointers. */
3793 union xfs_btree_key *lkp; /* left btree key */
3794 union xfs_btree_ptr *lpp; /* left address pointer */
3795 union xfs_btree_key *rkp; /* right btree key */
3796 union xfs_btree_ptr *rpp; /* right address pointer */
3797
3798 lkp = xfs_btree_key_addr(cur, lrecs + 1, left);
3799 lpp = xfs_btree_ptr_addr(cur, lrecs + 1, left);
3800 rkp = xfs_btree_key_addr(cur, 1, right);
3801 rpp = xfs_btree_ptr_addr(cur, 1, right);
3802#ifdef DEBUG
3803 for (i = 1; i < rrecs; i++) {
3804 error = xfs_btree_check_ptr(cur, rpp, i, level);
3805 if (error)
3806 goto error0;
3807 }
3808#endif
3809 xfs_btree_copy_keys(cur, lkp, rkp, rrecs);
3810 xfs_btree_copy_ptrs(cur, lpp, rpp, rrecs);
3811
3812 xfs_btree_log_keys(cur, lbp, lrecs + 1, lrecs + rrecs);
3813 xfs_btree_log_ptrs(cur, lbp, lrecs + 1, lrecs + rrecs);
3814 } else {
3815 /* It's a leaf. Move records. */
3816 union xfs_btree_rec *lrp; /* left record pointer */
3817 union xfs_btree_rec *rrp; /* right record pointer */
3818
3819 lrp = xfs_btree_rec_addr(cur, lrecs + 1, left);
3820 rrp = xfs_btree_rec_addr(cur, 1, right);
3821
3822 xfs_btree_copy_recs(cur, lrp, rrp, rrecs);
3823 xfs_btree_log_recs(cur, lbp, lrecs + 1, lrecs + rrecs);
3824 }
3825
3826 XFS_BTREE_STATS_INC(cur, join);
3827
3828 /*
3829 * Fix up the number of records and right block pointer in the
3830 * surviving block, and log it.
3831 */
3832 xfs_btree_set_numrecs(left, lrecs + rrecs);
3833 xfs_btree_get_sibling(cur, right, &cptr, XFS_BB_RIGHTSIB),
3834 xfs_btree_set_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
3835 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
3836
3837 /* If there is a right sibling, point it to the remaining block. */
3838 xfs_btree_get_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
3839 if (!xfs_btree_ptr_is_null(cur, &cptr)) {
3840 error = xfs_btree_read_buf_block(cur, &cptr, 0, &rrblock, &rrbp);
3841 if (error)
3842 goto error0;
3843 xfs_btree_set_sibling(cur, rrblock, &lptr, XFS_BB_LEFTSIB);
3844 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
3845 }
3846
3847 /* Free the deleted block. */
3848 error = xfs_btree_free_block(cur, rbp);
3849 if (error)
3850 goto error0;
3851
3852 /*
3853 * If we joined with the left neighbor, set the buffer in the
3854 * cursor to the left block, and fix up the index.
3855 */
3856 if (bp != lbp) {
3857 cur->bc_bufs[level] = lbp;
3858 cur->bc_ptrs[level] += lrecs;
3859 cur->bc_ra[level] = 0;
3860 }
3861 /*
3862 * If we joined with the right neighbor and there's a level above
3863 * us, increment the cursor at that level.
3864 */
3865 else if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) ||
3866 (level + 1 < cur->bc_nlevels)) {
3867 error = xfs_btree_increment(cur, level + 1, &i);
3868 if (error)
3869 goto error0;
3870 }
3871
3872 /*
3873 * Readjust the ptr at this level if it's not a leaf, since it's
3874 * still pointing at the deletion point, which makes the cursor
3875 * inconsistent. If this makes the ptr 0, the caller fixes it up.
3876 * We can't use decrement because it would change the next level up.
3877 */
3878 if (level > 0)
3879 cur->bc_ptrs[level]--;
3880
3881 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3882 /* Return value means the next level up has something to do. */
3883 *stat = 2;
3884 return 0;
3885
3886error0:
3887 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3888 if (tcur)
3889 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
3890 return error;
3891}
3892
3893/*
3894 * Delete the record pointed to by cur.
3895 * The cursor refers to the place where the record was (could be inserted)
3896 * when the operation returns.
3897 */
3898int /* error */
3899xfs_btree_delete(
3900 struct xfs_btree_cur *cur,
3901 int *stat) /* success/failure */
3902{
3903 int error; /* error return value */
3904 int level;
3905 int i;
3906
3907 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3908
3909 /*
3910 * Go up the tree, starting at leaf level.
3911 *
3912 * If 2 is returned then a join was done; go to the next level.
3913 * Otherwise we are done.
3914 */
3915 for (level = 0, i = 2; i == 2; level++) {
3916 error = xfs_btree_delrec(cur, level, &i);
3917 if (error)
3918 goto error0;
3919 }
3920
3921 if (i == 0) {
3922 for (level = 1; level < cur->bc_nlevels; level++) {
3923 if (cur->bc_ptrs[level] == 0) {
3924 error = xfs_btree_decrement(cur, level, &i);
3925 if (error)
3926 goto error0;
3927 break;
3928 }
3929 }
3930 }
3931
3932 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3933 *stat = i;
3934 return 0;
3935error0:
3936 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3937 return error;
3938}
3939
3940/*
3941 * Get the data from the pointed-to record.
3942 */
3943int /* error */
3944xfs_btree_get_rec(
3945 struct xfs_btree_cur *cur, /* btree cursor */
3946 union xfs_btree_rec **recp, /* output: btree record */
3947 int *stat) /* output: success/failure */
3948{
3949 struct xfs_btree_block *block; /* btree block */
3950 struct xfs_buf *bp; /* buffer pointer */
3951 int ptr; /* record number */
3952#ifdef DEBUG
3953 int error; /* error return value */
3954#endif
3955
3956 ptr = cur->bc_ptrs[0];
3957 block = xfs_btree_get_block(cur, 0, &bp);
3958
3959#ifdef DEBUG
3960 error = xfs_btree_check_block(cur, block, 0, bp);
3961 if (error)
3962 return error;
3963#endif
3964
3965 /*
3966 * Off the right end or left end, return failure.
3967 */
3968 if (ptr > xfs_btree_get_numrecs(block) || ptr <= 0) {
3969 *stat = 0;
3970 return 0;
3971 }
3972
3973 /*
3974 * Point to the record and extract its data.
3975 */
3976 *recp = xfs_btree_rec_addr(cur, ptr, block);
3977 *stat = 1;
3978 return 0;
3979}
3980
3981/*
3982 * Change the owner of a btree.
3983 *
3984 * The mechanism we use here is ordered buffer logging. Because we don't know
3985 * how many buffers were are going to need to modify, we don't really want to
3986 * have to make transaction reservations for the worst case of every buffer in a
3987 * full size btree as that may be more space that we can fit in the log....
3988 *
3989 * We do the btree walk in the most optimal manner possible - we have sibling
3990 * pointers so we can just walk all the blocks on each level from left to right
3991 * in a single pass, and then move to the next level and do the same. We can
3992 * also do readahead on the sibling pointers to get IO moving more quickly,
3993 * though for slow disks this is unlikely to make much difference to performance
3994 * as the amount of CPU work we have to do before moving to the next block is
3995 * relatively small.
3996 *
3997 * For each btree block that we load, modify the owner appropriately, set the
3998 * buffer as an ordered buffer and log it appropriately. We need to ensure that
3999 * we mark the region we change dirty so that if the buffer is relogged in
4000 * a subsequent transaction the changes we make here as an ordered buffer are
4001 * correctly relogged in that transaction. If we are in recovery context, then
4002 * just queue the modified buffer as delayed write buffer so the transaction
4003 * recovery completion writes the changes to disk.
4004 */
4005static int
4006xfs_btree_block_change_owner(
4007 struct xfs_btree_cur *cur,
4008 int level,
4009 __uint64_t new_owner,
4010 struct list_head *buffer_list)
4011{
4012 struct xfs_btree_block *block;
4013 struct xfs_buf *bp;
4014 union xfs_btree_ptr rptr;
4015
4016 /* do right sibling readahead */
4017 xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
4018
4019 /* modify the owner */
4020 block = xfs_btree_get_block(cur, level, &bp);
4021 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
4022 block->bb_u.l.bb_owner = cpu_to_be64(new_owner);
4023 else
4024 block->bb_u.s.bb_owner = cpu_to_be32(new_owner);
4025
4026 /*
4027 * If the block is a root block hosted in an inode, we might not have a
4028 * buffer pointer here and we shouldn't attempt to log the change as the
4029 * information is already held in the inode and discarded when the root
4030 * block is formatted into the on-disk inode fork. We still change it,
4031 * though, so everything is consistent in memory.
4032 */
4033 if (bp) {
4034 if (cur->bc_tp) {
4035 xfs_trans_ordered_buf(cur->bc_tp, bp);
4036 xfs_btree_log_block(cur, bp, XFS_BB_OWNER);
4037 } else {
4038 xfs_buf_delwri_queue(bp, buffer_list);
4039 }
4040 } else {
4041 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
4042 ASSERT(level == cur->bc_nlevels - 1);
4043 }
4044
4045 /* now read rh sibling block for next iteration */
4046 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
4047 if (xfs_btree_ptr_is_null(cur, &rptr))
4048 return -ENOENT;
4049
4050 return xfs_btree_lookup_get_block(cur, level, &rptr, &block);
4051}
4052
4053int
4054xfs_btree_change_owner(
4055 struct xfs_btree_cur *cur,
4056 __uint64_t new_owner,
4057 struct list_head *buffer_list)
4058{
4059 union xfs_btree_ptr lptr;
4060 int level;
4061 struct xfs_btree_block *block = NULL;
4062 int error = 0;
4063
4064 cur->bc_ops->init_ptr_from_cur(cur, &lptr);
4065
4066 /* for each level */
4067 for (level = cur->bc_nlevels - 1; level >= 0; level--) {
4068 /* grab the left hand block */
4069 error = xfs_btree_lookup_get_block(cur, level, &lptr, &block);
4070 if (error)
4071 return error;
4072
4073 /* readahead the left most block for the next level down */
4074 if (level > 0) {
4075 union xfs_btree_ptr *ptr;
4076
4077 ptr = xfs_btree_ptr_addr(cur, 1, block);
4078 xfs_btree_readahead_ptr(cur, ptr, 1);
4079
4080 /* save for the next iteration of the loop */
4081 lptr = *ptr;
4082 }
4083
4084 /* for each buffer in the level */
4085 do {
4086 error = xfs_btree_block_change_owner(cur, level,
4087 new_owner,
4088 buffer_list);
4089 } while (!error);
4090
4091 if (error != -ENOENT)
4092 return error;
4093 }
4094
4095 return 0;
4096}
4097
4098/**
4099 * xfs_btree_sblock_v5hdr_verify() -- verify the v5 fields of a short-format
4100 * btree block
4101 *
4102 * @bp: buffer containing the btree block
4103 * @max_recs: pointer to the m_*_mxr max records field in the xfs mount
4104 * @pag_max_level: pointer to the per-ag max level field
4105 */
4106bool
4107xfs_btree_sblock_v5hdr_verify(
4108 struct xfs_buf *bp)
4109{
4110 struct xfs_mount *mp = bp->b_target->bt_mount;
4111 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
4112 struct xfs_perag *pag = bp->b_pag;
4113
4114 if (!xfs_sb_version_hascrc(&mp->m_sb))
4115 return false;
4116 if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid))
4117 return false;
4118 if (block->bb_u.s.bb_blkno != cpu_to_be64(bp->b_bn))
4119 return false;
4120 if (pag && be32_to_cpu(block->bb_u.s.bb_owner) != pag->pag_agno)
4121 return false;
4122 return true;
4123}
4124
4125/**
4126 * xfs_btree_sblock_verify() -- verify a short-format btree block
4127 *
4128 * @bp: buffer containing the btree block
4129 * @max_recs: maximum records allowed in this btree node
4130 */
4131bool
4132xfs_btree_sblock_verify(
4133 struct xfs_buf *bp,
4134 unsigned int max_recs)
4135{
4136 struct xfs_mount *mp = bp->b_target->bt_mount;
4137 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
4138
4139 /* numrecs verification */
4140 if (be16_to_cpu(block->bb_numrecs) > max_recs)
4141 return false;
4142
4143 /* sibling pointer verification */
4144 if (!block->bb_u.s.bb_leftsib ||
4145 (be32_to_cpu(block->bb_u.s.bb_leftsib) >= mp->m_sb.sb_agblocks &&
4146 block->bb_u.s.bb_leftsib != cpu_to_be32(NULLAGBLOCK)))
4147 return false;
4148 if (!block->bb_u.s.bb_rightsib ||
4149 (be32_to_cpu(block->bb_u.s.bb_rightsib) >= mp->m_sb.sb_agblocks &&
4150 block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK)))
4151 return false;
4152
4153 return true;
4154}