nfsd4: typo logical vs bitwise negate for want_mask
[linux-btrfs-devel.git] / fs / xfs / xfs_btree.c
blobcabf4b5604aa6dff065ff2ab428a6e6efdd97a00
1 /*
2 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
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.
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.
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
18 #include "xfs.h"
19 #include "xfs_fs.h"
20 #include "xfs_types.h"
21 #include "xfs_bit.h"
22 #include "xfs_log.h"
23 #include "xfs_inum.h"
24 #include "xfs_trans.h"
25 #include "xfs_sb.h"
26 #include "xfs_ag.h"
27 #include "xfs_mount.h"
28 #include "xfs_bmap_btree.h"
29 #include "xfs_alloc_btree.h"
30 #include "xfs_ialloc_btree.h"
31 #include "xfs_dinode.h"
32 #include "xfs_inode.h"
33 #include "xfs_inode_item.h"
34 #include "xfs_btree.h"
35 #include "xfs_error.h"
36 #include "xfs_trace.h"
39 * Cursor allocation zone.
41 kmem_zone_t *xfs_btree_cur_zone;
44 * Btree magic numbers.
46 const __uint32_t xfs_magics[XFS_BTNUM_MAX] = {
47 XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, XFS_BMAP_MAGIC, XFS_IBT_MAGIC
51 STATIC int /* error (0 or EFSCORRUPTED) */
52 xfs_btree_check_lblock(
53 struct xfs_btree_cur *cur, /* btree cursor */
54 struct xfs_btree_block *block, /* btree long form block pointer */
55 int level, /* level of the btree block */
56 struct xfs_buf *bp) /* buffer for block, if any */
58 int lblock_ok; /* block passes checks */
59 struct xfs_mount *mp; /* file system mount point */
61 mp = cur->bc_mp;
62 lblock_ok =
63 be32_to_cpu(block->bb_magic) == xfs_magics[cur->bc_btnum] &&
64 be16_to_cpu(block->bb_level) == level &&
65 be16_to_cpu(block->bb_numrecs) <=
66 cur->bc_ops->get_maxrecs(cur, level) &&
67 block->bb_u.l.bb_leftsib &&
68 (block->bb_u.l.bb_leftsib == cpu_to_be64(NULLDFSBNO) ||
69 XFS_FSB_SANITY_CHECK(mp,
70 be64_to_cpu(block->bb_u.l.bb_leftsib))) &&
71 block->bb_u.l.bb_rightsib &&
72 (block->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO) ||
73 XFS_FSB_SANITY_CHECK(mp,
74 be64_to_cpu(block->bb_u.l.bb_rightsib)));
75 if (unlikely(XFS_TEST_ERROR(!lblock_ok, mp,
76 XFS_ERRTAG_BTREE_CHECK_LBLOCK,
77 XFS_RANDOM_BTREE_CHECK_LBLOCK))) {
78 if (bp)
79 trace_xfs_btree_corrupt(bp, _RET_IP_);
80 XFS_ERROR_REPORT("xfs_btree_check_lblock", XFS_ERRLEVEL_LOW,
81 mp);
82 return XFS_ERROR(EFSCORRUPTED);
84 return 0;
87 STATIC int /* error (0 or EFSCORRUPTED) */
88 xfs_btree_check_sblock(
89 struct xfs_btree_cur *cur, /* btree cursor */
90 struct xfs_btree_block *block, /* btree short form block pointer */
91 int level, /* level of the btree block */
92 struct xfs_buf *bp) /* buffer containing block */
94 struct xfs_buf *agbp; /* buffer for ag. freespace struct */
95 struct xfs_agf *agf; /* ag. freespace structure */
96 xfs_agblock_t agflen; /* native ag. freespace length */
97 int sblock_ok; /* block passes checks */
99 agbp = cur->bc_private.a.agbp;
100 agf = XFS_BUF_TO_AGF(agbp);
101 agflen = be32_to_cpu(agf->agf_length);
102 sblock_ok =
103 be32_to_cpu(block->bb_magic) == xfs_magics[cur->bc_btnum] &&
104 be16_to_cpu(block->bb_level) == level &&
105 be16_to_cpu(block->bb_numrecs) <=
106 cur->bc_ops->get_maxrecs(cur, level) &&
107 (block->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK) ||
108 be32_to_cpu(block->bb_u.s.bb_leftsib) < agflen) &&
109 block->bb_u.s.bb_leftsib &&
110 (block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK) ||
111 be32_to_cpu(block->bb_u.s.bb_rightsib) < agflen) &&
112 block->bb_u.s.bb_rightsib;
113 if (unlikely(XFS_TEST_ERROR(!sblock_ok, cur->bc_mp,
114 XFS_ERRTAG_BTREE_CHECK_SBLOCK,
115 XFS_RANDOM_BTREE_CHECK_SBLOCK))) {
116 if (bp)
117 trace_xfs_btree_corrupt(bp, _RET_IP_);
118 XFS_CORRUPTION_ERROR("xfs_btree_check_sblock",
119 XFS_ERRLEVEL_LOW, cur->bc_mp, block);
120 return XFS_ERROR(EFSCORRUPTED);
122 return 0;
126 * Debug routine: check that block header is ok.
129 xfs_btree_check_block(
130 struct xfs_btree_cur *cur, /* btree cursor */
131 struct xfs_btree_block *block, /* generic btree block pointer */
132 int level, /* level of the btree block */
133 struct xfs_buf *bp) /* buffer containing block, if any */
135 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
136 return xfs_btree_check_lblock(cur, block, level, bp);
137 else
138 return xfs_btree_check_sblock(cur, block, level, bp);
142 * Check that (long) pointer is ok.
144 int /* error (0 or EFSCORRUPTED) */
145 xfs_btree_check_lptr(
146 struct xfs_btree_cur *cur, /* btree cursor */
147 xfs_dfsbno_t bno, /* btree block disk address */
148 int level) /* btree block level */
150 XFS_WANT_CORRUPTED_RETURN(
151 level > 0 &&
152 bno != NULLDFSBNO &&
153 XFS_FSB_SANITY_CHECK(cur->bc_mp, bno));
154 return 0;
157 #ifdef DEBUG
159 * Check that (short) pointer is ok.
161 STATIC int /* error (0 or EFSCORRUPTED) */
162 xfs_btree_check_sptr(
163 struct xfs_btree_cur *cur, /* btree cursor */
164 xfs_agblock_t bno, /* btree block disk address */
165 int level) /* btree block level */
167 xfs_agblock_t agblocks = cur->bc_mp->m_sb.sb_agblocks;
169 XFS_WANT_CORRUPTED_RETURN(
170 level > 0 &&
171 bno != NULLAGBLOCK &&
172 bno != 0 &&
173 bno < agblocks);
174 return 0;
178 * Check that block ptr is ok.
180 STATIC int /* error (0 or EFSCORRUPTED) */
181 xfs_btree_check_ptr(
182 struct xfs_btree_cur *cur, /* btree cursor */
183 union xfs_btree_ptr *ptr, /* btree block disk address */
184 int index, /* offset from ptr to check */
185 int level) /* btree block level */
187 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
188 return xfs_btree_check_lptr(cur,
189 be64_to_cpu((&ptr->l)[index]), level);
190 } else {
191 return xfs_btree_check_sptr(cur,
192 be32_to_cpu((&ptr->s)[index]), level);
195 #endif
198 * Delete the btree cursor.
200 void
201 xfs_btree_del_cursor(
202 xfs_btree_cur_t *cur, /* btree cursor */
203 int error) /* del because of error */
205 int i; /* btree level */
208 * Clear the buffer pointers, and release the buffers.
209 * If we're doing this in the face of an error, we
210 * need to make sure to inspect all of the entries
211 * in the bc_bufs array for buffers to be unlocked.
212 * This is because some of the btree code works from
213 * level n down to 0, and if we get an error along
214 * the way we won't have initialized all the entries
215 * down to 0.
217 for (i = 0; i < cur->bc_nlevels; i++) {
218 if (cur->bc_bufs[i])
219 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[i]);
220 else if (!error)
221 break;
224 * Can't free a bmap cursor without having dealt with the
225 * allocated indirect blocks' accounting.
227 ASSERT(cur->bc_btnum != XFS_BTNUM_BMAP ||
228 cur->bc_private.b.allocated == 0);
230 * Free the cursor.
232 kmem_zone_free(xfs_btree_cur_zone, cur);
236 * Duplicate the btree cursor.
237 * Allocate a new one, copy the record, re-get the buffers.
239 int /* error */
240 xfs_btree_dup_cursor(
241 xfs_btree_cur_t *cur, /* input cursor */
242 xfs_btree_cur_t **ncur) /* output cursor */
244 xfs_buf_t *bp; /* btree block's buffer pointer */
245 int error; /* error return value */
246 int i; /* level number of btree block */
247 xfs_mount_t *mp; /* mount structure for filesystem */
248 xfs_btree_cur_t *new; /* new cursor value */
249 xfs_trans_t *tp; /* transaction pointer, can be NULL */
251 tp = cur->bc_tp;
252 mp = cur->bc_mp;
255 * Allocate a new cursor like the old one.
257 new = cur->bc_ops->dup_cursor(cur);
260 * Copy the record currently in the cursor.
262 new->bc_rec = cur->bc_rec;
265 * For each level current, re-get the buffer and copy the ptr value.
267 for (i = 0; i < new->bc_nlevels; i++) {
268 new->bc_ptrs[i] = cur->bc_ptrs[i];
269 new->bc_ra[i] = cur->bc_ra[i];
270 if ((bp = cur->bc_bufs[i])) {
271 if ((error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
272 XFS_BUF_ADDR(bp), mp->m_bsize, 0, &bp))) {
273 xfs_btree_del_cursor(new, error);
274 *ncur = NULL;
275 return error;
277 new->bc_bufs[i] = bp;
278 ASSERT(bp);
279 ASSERT(!XFS_BUF_GETERROR(bp));
280 } else
281 new->bc_bufs[i] = NULL;
283 *ncur = new;
284 return 0;
288 * XFS btree block layout and addressing:
290 * There are two types of blocks in the btree: leaf and non-leaf blocks.
292 * The leaf record start with a header then followed by records containing
293 * the values. A non-leaf block also starts with the same header, and
294 * then first contains lookup keys followed by an equal number of pointers
295 * to the btree blocks at the previous level.
297 * +--------+-------+-------+-------+-------+-------+-------+
298 * Leaf: | header | rec 1 | rec 2 | rec 3 | rec 4 | rec 5 | rec N |
299 * +--------+-------+-------+-------+-------+-------+-------+
301 * +--------+-------+-------+-------+-------+-------+-------+
302 * Non-Leaf: | header | key 1 | key 2 | key N | ptr 1 | ptr 2 | ptr N |
303 * +--------+-------+-------+-------+-------+-------+-------+
305 * The header is called struct xfs_btree_block for reasons better left unknown
306 * and comes in different versions for short (32bit) and long (64bit) block
307 * pointers. The record and key structures are defined by the btree instances
308 * and opaque to the btree core. The block pointers are simple disk endian
309 * integers, available in a short (32bit) and long (64bit) variant.
311 * The helpers below calculate the offset of a given record, key or pointer
312 * into a btree block (xfs_btree_*_offset) or return a pointer to the given
313 * record, key or pointer (xfs_btree_*_addr). Note that all addressing
314 * inside the btree block is done using indices starting at one, not zero!
318 * Return size of the btree block header for this btree instance.
320 static inline size_t xfs_btree_block_len(struct xfs_btree_cur *cur)
322 return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
323 XFS_BTREE_LBLOCK_LEN :
324 XFS_BTREE_SBLOCK_LEN;
328 * Return size of btree block pointers for this btree instance.
330 static inline size_t xfs_btree_ptr_len(struct xfs_btree_cur *cur)
332 return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
333 sizeof(__be64) : sizeof(__be32);
337 * Calculate offset of the n-th record in a btree block.
339 STATIC size_t
340 xfs_btree_rec_offset(
341 struct xfs_btree_cur *cur,
342 int n)
344 return xfs_btree_block_len(cur) +
345 (n - 1) * cur->bc_ops->rec_len;
349 * Calculate offset of the n-th key in a btree block.
351 STATIC size_t
352 xfs_btree_key_offset(
353 struct xfs_btree_cur *cur,
354 int n)
356 return xfs_btree_block_len(cur) +
357 (n - 1) * cur->bc_ops->key_len;
361 * Calculate offset of the n-th block pointer in a btree block.
363 STATIC size_t
364 xfs_btree_ptr_offset(
365 struct xfs_btree_cur *cur,
366 int n,
367 int level)
369 return xfs_btree_block_len(cur) +
370 cur->bc_ops->get_maxrecs(cur, level) * cur->bc_ops->key_len +
371 (n - 1) * xfs_btree_ptr_len(cur);
375 * Return a pointer to the n-th record in the btree block.
377 STATIC union xfs_btree_rec *
378 xfs_btree_rec_addr(
379 struct xfs_btree_cur *cur,
380 int n,
381 struct xfs_btree_block *block)
383 return (union xfs_btree_rec *)
384 ((char *)block + xfs_btree_rec_offset(cur, n));
388 * Return a pointer to the n-th key in the btree block.
390 STATIC union xfs_btree_key *
391 xfs_btree_key_addr(
392 struct xfs_btree_cur *cur,
393 int n,
394 struct xfs_btree_block *block)
396 return (union xfs_btree_key *)
397 ((char *)block + xfs_btree_key_offset(cur, n));
401 * Return a pointer to the n-th block pointer in the btree block.
403 STATIC union xfs_btree_ptr *
404 xfs_btree_ptr_addr(
405 struct xfs_btree_cur *cur,
406 int n,
407 struct xfs_btree_block *block)
409 int level = xfs_btree_get_level(block);
411 ASSERT(block->bb_level != 0);
413 return (union xfs_btree_ptr *)
414 ((char *)block + xfs_btree_ptr_offset(cur, n, level));
418 * Get a the root block which is stored in the inode.
420 * For now this btree implementation assumes the btree root is always
421 * stored in the if_broot field of an inode fork.
423 STATIC struct xfs_btree_block *
424 xfs_btree_get_iroot(
425 struct xfs_btree_cur *cur)
427 struct xfs_ifork *ifp;
429 ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, cur->bc_private.b.whichfork);
430 return (struct xfs_btree_block *)ifp->if_broot;
434 * Retrieve the block pointer from the cursor at the given level.
435 * This may be an inode btree root or from a buffer.
437 STATIC struct xfs_btree_block * /* generic btree block pointer */
438 xfs_btree_get_block(
439 struct xfs_btree_cur *cur, /* btree cursor */
440 int level, /* level in btree */
441 struct xfs_buf **bpp) /* buffer containing the block */
443 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
444 (level == cur->bc_nlevels - 1)) {
445 *bpp = NULL;
446 return xfs_btree_get_iroot(cur);
449 *bpp = cur->bc_bufs[level];
450 return XFS_BUF_TO_BLOCK(*bpp);
454 * Get a buffer for the block, return it with no data read.
455 * Long-form addressing.
457 xfs_buf_t * /* buffer for fsbno */
458 xfs_btree_get_bufl(
459 xfs_mount_t *mp, /* file system mount point */
460 xfs_trans_t *tp, /* transaction pointer */
461 xfs_fsblock_t fsbno, /* file system block number */
462 uint lock) /* lock flags for get_buf */
464 xfs_buf_t *bp; /* buffer pointer (return value) */
465 xfs_daddr_t d; /* real disk block address */
467 ASSERT(fsbno != NULLFSBLOCK);
468 d = XFS_FSB_TO_DADDR(mp, fsbno);
469 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
470 ASSERT(bp);
471 ASSERT(!XFS_BUF_GETERROR(bp));
472 return bp;
476 * Get a buffer for the block, return it with no data read.
477 * Short-form addressing.
479 xfs_buf_t * /* buffer for agno/agbno */
480 xfs_btree_get_bufs(
481 xfs_mount_t *mp, /* file system mount point */
482 xfs_trans_t *tp, /* transaction pointer */
483 xfs_agnumber_t agno, /* allocation group number */
484 xfs_agblock_t agbno, /* allocation group block number */
485 uint lock) /* lock flags for get_buf */
487 xfs_buf_t *bp; /* buffer pointer (return value) */
488 xfs_daddr_t d; /* real disk block address */
490 ASSERT(agno != NULLAGNUMBER);
491 ASSERT(agbno != NULLAGBLOCK);
492 d = XFS_AGB_TO_DADDR(mp, agno, agbno);
493 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
494 ASSERT(bp);
495 ASSERT(!XFS_BUF_GETERROR(bp));
496 return bp;
500 * Check for the cursor referring to the last block at the given level.
502 int /* 1=is last block, 0=not last block */
503 xfs_btree_islastblock(
504 xfs_btree_cur_t *cur, /* btree cursor */
505 int level) /* level to check */
507 struct xfs_btree_block *block; /* generic btree block pointer */
508 xfs_buf_t *bp; /* buffer containing block */
510 block = xfs_btree_get_block(cur, level, &bp);
511 xfs_btree_check_block(cur, block, level, bp);
512 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
513 return block->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO);
514 else
515 return block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK);
519 * Change the cursor to point to the first record at the given level.
520 * Other levels are unaffected.
522 STATIC int /* success=1, failure=0 */
523 xfs_btree_firstrec(
524 xfs_btree_cur_t *cur, /* btree cursor */
525 int level) /* level to change */
527 struct xfs_btree_block *block; /* generic btree block pointer */
528 xfs_buf_t *bp; /* buffer containing block */
531 * Get the block pointer for this level.
533 block = xfs_btree_get_block(cur, level, &bp);
534 xfs_btree_check_block(cur, block, level, bp);
536 * It's empty, there is no such record.
538 if (!block->bb_numrecs)
539 return 0;
541 * Set the ptr value to 1, that's the first record/key.
543 cur->bc_ptrs[level] = 1;
544 return 1;
548 * Change the cursor to point to the last record in the current block
549 * at the given level. Other levels are unaffected.
551 STATIC int /* success=1, failure=0 */
552 xfs_btree_lastrec(
553 xfs_btree_cur_t *cur, /* btree cursor */
554 int level) /* level to change */
556 struct xfs_btree_block *block; /* generic btree block pointer */
557 xfs_buf_t *bp; /* buffer containing block */
560 * Get the block pointer for this level.
562 block = xfs_btree_get_block(cur, level, &bp);
563 xfs_btree_check_block(cur, block, level, bp);
565 * It's empty, there is no such record.
567 if (!block->bb_numrecs)
568 return 0;
570 * Set the ptr value to numrecs, that's the last record/key.
572 cur->bc_ptrs[level] = be16_to_cpu(block->bb_numrecs);
573 return 1;
577 * Compute first and last byte offsets for the fields given.
578 * Interprets the offsets table, which contains struct field offsets.
580 void
581 xfs_btree_offsets(
582 __int64_t fields, /* bitmask of fields */
583 const short *offsets, /* table of field offsets */
584 int nbits, /* number of bits to inspect */
585 int *first, /* output: first byte offset */
586 int *last) /* output: last byte offset */
588 int i; /* current bit number */
589 __int64_t imask; /* mask for current bit number */
591 ASSERT(fields != 0);
593 * Find the lowest bit, so the first byte offset.
595 for (i = 0, imask = 1LL; ; i++, imask <<= 1) {
596 if (imask & fields) {
597 *first = offsets[i];
598 break;
602 * Find the highest bit, so the last byte offset.
604 for (i = nbits - 1, imask = 1LL << i; ; i--, imask >>= 1) {
605 if (imask & fields) {
606 *last = offsets[i + 1] - 1;
607 break;
613 * Get a buffer for the block, return it read in.
614 * Long-form addressing.
616 int /* error */
617 xfs_btree_read_bufl(
618 xfs_mount_t *mp, /* file system mount point */
619 xfs_trans_t *tp, /* transaction pointer */
620 xfs_fsblock_t fsbno, /* file system block number */
621 uint lock, /* lock flags for read_buf */
622 xfs_buf_t **bpp, /* buffer for fsbno */
623 int refval) /* ref count value for buffer */
625 xfs_buf_t *bp; /* return value */
626 xfs_daddr_t d; /* real disk block address */
627 int error;
629 ASSERT(fsbno != NULLFSBLOCK);
630 d = XFS_FSB_TO_DADDR(mp, fsbno);
631 if ((error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
632 mp->m_bsize, lock, &bp))) {
633 return error;
635 ASSERT(!bp || !XFS_BUF_GETERROR(bp));
636 if (bp)
637 XFS_BUF_SET_VTYPE_REF(bp, B_FS_MAP, refval);
638 *bpp = bp;
639 return 0;
643 * Read-ahead the block, don't wait for it, don't return a buffer.
644 * Long-form addressing.
646 /* ARGSUSED */
647 void
648 xfs_btree_reada_bufl(
649 xfs_mount_t *mp, /* file system mount point */
650 xfs_fsblock_t fsbno, /* file system block number */
651 xfs_extlen_t count) /* count of filesystem blocks */
653 xfs_daddr_t d;
655 ASSERT(fsbno != NULLFSBLOCK);
656 d = XFS_FSB_TO_DADDR(mp, fsbno);
657 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count);
661 * Read-ahead the block, don't wait for it, don't return a buffer.
662 * Short-form addressing.
664 /* ARGSUSED */
665 void
666 xfs_btree_reada_bufs(
667 xfs_mount_t *mp, /* file system mount point */
668 xfs_agnumber_t agno, /* allocation group number */
669 xfs_agblock_t agbno, /* allocation group block number */
670 xfs_extlen_t count) /* count of filesystem blocks */
672 xfs_daddr_t d;
674 ASSERT(agno != NULLAGNUMBER);
675 ASSERT(agbno != NULLAGBLOCK);
676 d = XFS_AGB_TO_DADDR(mp, agno, agbno);
677 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count);
680 STATIC int
681 xfs_btree_readahead_lblock(
682 struct xfs_btree_cur *cur,
683 int lr,
684 struct xfs_btree_block *block)
686 int rval = 0;
687 xfs_dfsbno_t left = be64_to_cpu(block->bb_u.l.bb_leftsib);
688 xfs_dfsbno_t right = be64_to_cpu(block->bb_u.l.bb_rightsib);
690 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLDFSBNO) {
691 xfs_btree_reada_bufl(cur->bc_mp, left, 1);
692 rval++;
695 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLDFSBNO) {
696 xfs_btree_reada_bufl(cur->bc_mp, right, 1);
697 rval++;
700 return rval;
703 STATIC int
704 xfs_btree_readahead_sblock(
705 struct xfs_btree_cur *cur,
706 int lr,
707 struct xfs_btree_block *block)
709 int rval = 0;
710 xfs_agblock_t left = be32_to_cpu(block->bb_u.s.bb_leftsib);
711 xfs_agblock_t right = be32_to_cpu(block->bb_u.s.bb_rightsib);
714 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLAGBLOCK) {
715 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
716 left, 1);
717 rval++;
720 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLAGBLOCK) {
721 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
722 right, 1);
723 rval++;
726 return rval;
730 * Read-ahead btree blocks, at the given level.
731 * Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA.
733 STATIC int
734 xfs_btree_readahead(
735 struct xfs_btree_cur *cur, /* btree cursor */
736 int lev, /* level in btree */
737 int lr) /* left/right bits */
739 struct xfs_btree_block *block;
742 * No readahead needed if we are at the root level and the
743 * btree root is stored in the inode.
745 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
746 (lev == cur->bc_nlevels - 1))
747 return 0;
749 if ((cur->bc_ra[lev] | lr) == cur->bc_ra[lev])
750 return 0;
752 cur->bc_ra[lev] |= lr;
753 block = XFS_BUF_TO_BLOCK(cur->bc_bufs[lev]);
755 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
756 return xfs_btree_readahead_lblock(cur, lr, block);
757 return xfs_btree_readahead_sblock(cur, lr, block);
761 * Set the buffer for level "lev" in the cursor to bp, releasing
762 * any previous buffer.
764 STATIC void
765 xfs_btree_setbuf(
766 xfs_btree_cur_t *cur, /* btree cursor */
767 int lev, /* level in btree */
768 xfs_buf_t *bp) /* new buffer to set */
770 struct xfs_btree_block *b; /* btree block */
772 if (cur->bc_bufs[lev])
773 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[lev]);
774 cur->bc_bufs[lev] = bp;
775 cur->bc_ra[lev] = 0;
777 b = XFS_BUF_TO_BLOCK(bp);
778 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
779 if (b->bb_u.l.bb_leftsib == cpu_to_be64(NULLDFSBNO))
780 cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
781 if (b->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO))
782 cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
783 } else {
784 if (b->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK))
785 cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
786 if (b->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK))
787 cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
791 STATIC int
792 xfs_btree_ptr_is_null(
793 struct xfs_btree_cur *cur,
794 union xfs_btree_ptr *ptr)
796 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
797 return ptr->l == cpu_to_be64(NULLDFSBNO);
798 else
799 return ptr->s == cpu_to_be32(NULLAGBLOCK);
802 STATIC void
803 xfs_btree_set_ptr_null(
804 struct xfs_btree_cur *cur,
805 union xfs_btree_ptr *ptr)
807 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
808 ptr->l = cpu_to_be64(NULLDFSBNO);
809 else
810 ptr->s = cpu_to_be32(NULLAGBLOCK);
814 * Get/set/init sibling pointers
816 STATIC void
817 xfs_btree_get_sibling(
818 struct xfs_btree_cur *cur,
819 struct xfs_btree_block *block,
820 union xfs_btree_ptr *ptr,
821 int lr)
823 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
825 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
826 if (lr == XFS_BB_RIGHTSIB)
827 ptr->l = block->bb_u.l.bb_rightsib;
828 else
829 ptr->l = block->bb_u.l.bb_leftsib;
830 } else {
831 if (lr == XFS_BB_RIGHTSIB)
832 ptr->s = block->bb_u.s.bb_rightsib;
833 else
834 ptr->s = block->bb_u.s.bb_leftsib;
838 STATIC void
839 xfs_btree_set_sibling(
840 struct xfs_btree_cur *cur,
841 struct xfs_btree_block *block,
842 union xfs_btree_ptr *ptr,
843 int lr)
845 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
847 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
848 if (lr == XFS_BB_RIGHTSIB)
849 block->bb_u.l.bb_rightsib = ptr->l;
850 else
851 block->bb_u.l.bb_leftsib = ptr->l;
852 } else {
853 if (lr == XFS_BB_RIGHTSIB)
854 block->bb_u.s.bb_rightsib = ptr->s;
855 else
856 block->bb_u.s.bb_leftsib = ptr->s;
860 STATIC void
861 xfs_btree_init_block(
862 struct xfs_btree_cur *cur,
863 int level,
864 int numrecs,
865 struct xfs_btree_block *new) /* new block */
867 new->bb_magic = cpu_to_be32(xfs_magics[cur->bc_btnum]);
868 new->bb_level = cpu_to_be16(level);
869 new->bb_numrecs = cpu_to_be16(numrecs);
871 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
872 new->bb_u.l.bb_leftsib = cpu_to_be64(NULLDFSBNO);
873 new->bb_u.l.bb_rightsib = cpu_to_be64(NULLDFSBNO);
874 } else {
875 new->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
876 new->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
881 * Return true if ptr is the last record in the btree and
882 * we need to track updateѕ to this record. The decision
883 * will be further refined in the update_lastrec method.
885 STATIC int
886 xfs_btree_is_lastrec(
887 struct xfs_btree_cur *cur,
888 struct xfs_btree_block *block,
889 int level)
891 union xfs_btree_ptr ptr;
893 if (level > 0)
894 return 0;
895 if (!(cur->bc_flags & XFS_BTREE_LASTREC_UPDATE))
896 return 0;
898 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
899 if (!xfs_btree_ptr_is_null(cur, &ptr))
900 return 0;
901 return 1;
904 STATIC void
905 xfs_btree_buf_to_ptr(
906 struct xfs_btree_cur *cur,
907 struct xfs_buf *bp,
908 union xfs_btree_ptr *ptr)
910 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
911 ptr->l = cpu_to_be64(XFS_DADDR_TO_FSB(cur->bc_mp,
912 XFS_BUF_ADDR(bp)));
913 else {
914 ptr->s = cpu_to_be32(xfs_daddr_to_agbno(cur->bc_mp,
915 XFS_BUF_ADDR(bp)));
919 STATIC xfs_daddr_t
920 xfs_btree_ptr_to_daddr(
921 struct xfs_btree_cur *cur,
922 union xfs_btree_ptr *ptr)
924 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
925 ASSERT(ptr->l != cpu_to_be64(NULLDFSBNO));
927 return XFS_FSB_TO_DADDR(cur->bc_mp, be64_to_cpu(ptr->l));
928 } else {
929 ASSERT(cur->bc_private.a.agno != NULLAGNUMBER);
930 ASSERT(ptr->s != cpu_to_be32(NULLAGBLOCK));
932 return XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_private.a.agno,
933 be32_to_cpu(ptr->s));
937 STATIC void
938 xfs_btree_set_refs(
939 struct xfs_btree_cur *cur,
940 struct xfs_buf *bp)
942 switch (cur->bc_btnum) {
943 case XFS_BTNUM_BNO:
944 case XFS_BTNUM_CNT:
945 XFS_BUF_SET_VTYPE_REF(bp, B_FS_MAP, XFS_ALLOC_BTREE_REF);
946 break;
947 case XFS_BTNUM_INO:
948 XFS_BUF_SET_VTYPE_REF(bp, B_FS_INOMAP, XFS_INO_BTREE_REF);
949 break;
950 case XFS_BTNUM_BMAP:
951 XFS_BUF_SET_VTYPE_REF(bp, B_FS_MAP, XFS_BMAP_BTREE_REF);
952 break;
953 default:
954 ASSERT(0);
958 STATIC int
959 xfs_btree_get_buf_block(
960 struct xfs_btree_cur *cur,
961 union xfs_btree_ptr *ptr,
962 int flags,
963 struct xfs_btree_block **block,
964 struct xfs_buf **bpp)
966 struct xfs_mount *mp = cur->bc_mp;
967 xfs_daddr_t d;
969 /* need to sort out how callers deal with failures first */
970 ASSERT(!(flags & XBF_TRYLOCK));
972 d = xfs_btree_ptr_to_daddr(cur, ptr);
973 *bpp = xfs_trans_get_buf(cur->bc_tp, mp->m_ddev_targp, d,
974 mp->m_bsize, flags);
976 ASSERT(*bpp);
977 ASSERT(!XFS_BUF_GETERROR(*bpp));
979 *block = XFS_BUF_TO_BLOCK(*bpp);
980 return 0;
984 * Read in the buffer at the given ptr and return the buffer and
985 * the block pointer within the buffer.
987 STATIC int
988 xfs_btree_read_buf_block(
989 struct xfs_btree_cur *cur,
990 union xfs_btree_ptr *ptr,
991 int level,
992 int flags,
993 struct xfs_btree_block **block,
994 struct xfs_buf **bpp)
996 struct xfs_mount *mp = cur->bc_mp;
997 xfs_daddr_t d;
998 int error;
1000 /* need to sort out how callers deal with failures first */
1001 ASSERT(!(flags & XBF_TRYLOCK));
1003 d = xfs_btree_ptr_to_daddr(cur, ptr);
1004 error = xfs_trans_read_buf(mp, cur->bc_tp, mp->m_ddev_targp, d,
1005 mp->m_bsize, flags, bpp);
1006 if (error)
1007 return error;
1009 ASSERT(*bpp != NULL);
1010 ASSERT(!XFS_BUF_GETERROR(*bpp));
1012 xfs_btree_set_refs(cur, *bpp);
1013 *block = XFS_BUF_TO_BLOCK(*bpp);
1015 error = xfs_btree_check_block(cur, *block, level, *bpp);
1016 if (error)
1017 xfs_trans_brelse(cur->bc_tp, *bpp);
1018 return error;
1022 * Copy keys from one btree block to another.
1024 STATIC void
1025 xfs_btree_copy_keys(
1026 struct xfs_btree_cur *cur,
1027 union xfs_btree_key *dst_key,
1028 union xfs_btree_key *src_key,
1029 int numkeys)
1031 ASSERT(numkeys >= 0);
1032 memcpy(dst_key, src_key, numkeys * cur->bc_ops->key_len);
1036 * Copy records from one btree block to another.
1038 STATIC void
1039 xfs_btree_copy_recs(
1040 struct xfs_btree_cur *cur,
1041 union xfs_btree_rec *dst_rec,
1042 union xfs_btree_rec *src_rec,
1043 int numrecs)
1045 ASSERT(numrecs >= 0);
1046 memcpy(dst_rec, src_rec, numrecs * cur->bc_ops->rec_len);
1050 * Copy block pointers from one btree block to another.
1052 STATIC void
1053 xfs_btree_copy_ptrs(
1054 struct xfs_btree_cur *cur,
1055 union xfs_btree_ptr *dst_ptr,
1056 union xfs_btree_ptr *src_ptr,
1057 int numptrs)
1059 ASSERT(numptrs >= 0);
1060 memcpy(dst_ptr, src_ptr, numptrs * xfs_btree_ptr_len(cur));
1064 * Shift keys one index left/right inside a single btree block.
1066 STATIC void
1067 xfs_btree_shift_keys(
1068 struct xfs_btree_cur *cur,
1069 union xfs_btree_key *key,
1070 int dir,
1071 int numkeys)
1073 char *dst_key;
1075 ASSERT(numkeys >= 0);
1076 ASSERT(dir == 1 || dir == -1);
1078 dst_key = (char *)key + (dir * cur->bc_ops->key_len);
1079 memmove(dst_key, key, numkeys * cur->bc_ops->key_len);
1083 * Shift records one index left/right inside a single btree block.
1085 STATIC void
1086 xfs_btree_shift_recs(
1087 struct xfs_btree_cur *cur,
1088 union xfs_btree_rec *rec,
1089 int dir,
1090 int numrecs)
1092 char *dst_rec;
1094 ASSERT(numrecs >= 0);
1095 ASSERT(dir == 1 || dir == -1);
1097 dst_rec = (char *)rec + (dir * cur->bc_ops->rec_len);
1098 memmove(dst_rec, rec, numrecs * cur->bc_ops->rec_len);
1102 * Shift block pointers one index left/right inside a single btree block.
1104 STATIC void
1105 xfs_btree_shift_ptrs(
1106 struct xfs_btree_cur *cur,
1107 union xfs_btree_ptr *ptr,
1108 int dir,
1109 int numptrs)
1111 char *dst_ptr;
1113 ASSERT(numptrs >= 0);
1114 ASSERT(dir == 1 || dir == -1);
1116 dst_ptr = (char *)ptr + (dir * xfs_btree_ptr_len(cur));
1117 memmove(dst_ptr, ptr, numptrs * xfs_btree_ptr_len(cur));
1121 * Log key values from the btree block.
1123 STATIC void
1124 xfs_btree_log_keys(
1125 struct xfs_btree_cur *cur,
1126 struct xfs_buf *bp,
1127 int first,
1128 int last)
1130 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1131 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1133 if (bp) {
1134 xfs_trans_log_buf(cur->bc_tp, bp,
1135 xfs_btree_key_offset(cur, first),
1136 xfs_btree_key_offset(cur, last + 1) - 1);
1137 } else {
1138 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1139 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1142 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1146 * Log record values from the btree block.
1148 void
1149 xfs_btree_log_recs(
1150 struct xfs_btree_cur *cur,
1151 struct xfs_buf *bp,
1152 int first,
1153 int last)
1155 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1156 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1158 xfs_trans_log_buf(cur->bc_tp, bp,
1159 xfs_btree_rec_offset(cur, first),
1160 xfs_btree_rec_offset(cur, last + 1) - 1);
1162 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1166 * Log block pointer fields from a btree block (nonleaf).
1168 STATIC void
1169 xfs_btree_log_ptrs(
1170 struct xfs_btree_cur *cur, /* btree cursor */
1171 struct xfs_buf *bp, /* buffer containing btree block */
1172 int first, /* index of first pointer to log */
1173 int last) /* index of last pointer to log */
1175 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1176 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1178 if (bp) {
1179 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
1180 int level = xfs_btree_get_level(block);
1182 xfs_trans_log_buf(cur->bc_tp, bp,
1183 xfs_btree_ptr_offset(cur, first, level),
1184 xfs_btree_ptr_offset(cur, last + 1, level) - 1);
1185 } else {
1186 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1187 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1190 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1194 * Log fields from a btree block header.
1196 void
1197 xfs_btree_log_block(
1198 struct xfs_btree_cur *cur, /* btree cursor */
1199 struct xfs_buf *bp, /* buffer containing btree block */
1200 int fields) /* mask of fields: XFS_BB_... */
1202 int first; /* first byte offset logged */
1203 int last; /* last byte offset logged */
1204 static const short soffsets[] = { /* table of offsets (short) */
1205 offsetof(struct xfs_btree_block, bb_magic),
1206 offsetof(struct xfs_btree_block, bb_level),
1207 offsetof(struct xfs_btree_block, bb_numrecs),
1208 offsetof(struct xfs_btree_block, bb_u.s.bb_leftsib),
1209 offsetof(struct xfs_btree_block, bb_u.s.bb_rightsib),
1210 XFS_BTREE_SBLOCK_LEN
1212 static const short loffsets[] = { /* table of offsets (long) */
1213 offsetof(struct xfs_btree_block, bb_magic),
1214 offsetof(struct xfs_btree_block, bb_level),
1215 offsetof(struct xfs_btree_block, bb_numrecs),
1216 offsetof(struct xfs_btree_block, bb_u.l.bb_leftsib),
1217 offsetof(struct xfs_btree_block, bb_u.l.bb_rightsib),
1218 XFS_BTREE_LBLOCK_LEN
1221 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1222 XFS_BTREE_TRACE_ARGBI(cur, bp, fields);
1224 if (bp) {
1225 xfs_btree_offsets(fields,
1226 (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
1227 loffsets : soffsets,
1228 XFS_BB_NUM_BITS, &first, &last);
1229 xfs_trans_log_buf(cur->bc_tp, bp, first, last);
1230 } else {
1231 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1232 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1235 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1239 * Increment cursor by one record at the level.
1240 * For nonzero levels the leaf-ward information is untouched.
1242 int /* error */
1243 xfs_btree_increment(
1244 struct xfs_btree_cur *cur,
1245 int level,
1246 int *stat) /* success/failure */
1248 struct xfs_btree_block *block;
1249 union xfs_btree_ptr ptr;
1250 struct xfs_buf *bp;
1251 int error; /* error return value */
1252 int lev;
1254 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1255 XFS_BTREE_TRACE_ARGI(cur, level);
1257 ASSERT(level < cur->bc_nlevels);
1259 /* Read-ahead to the right at this level. */
1260 xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
1262 /* Get a pointer to the btree block. */
1263 block = xfs_btree_get_block(cur, level, &bp);
1265 #ifdef DEBUG
1266 error = xfs_btree_check_block(cur, block, level, bp);
1267 if (error)
1268 goto error0;
1269 #endif
1271 /* We're done if we remain in the block after the increment. */
1272 if (++cur->bc_ptrs[level] <= xfs_btree_get_numrecs(block))
1273 goto out1;
1275 /* Fail if we just went off the right edge of the tree. */
1276 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1277 if (xfs_btree_ptr_is_null(cur, &ptr))
1278 goto out0;
1280 XFS_BTREE_STATS_INC(cur, increment);
1283 * March up the tree incrementing pointers.
1284 * Stop when we don't go off the right edge of a block.
1286 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1287 block = xfs_btree_get_block(cur, lev, &bp);
1289 #ifdef DEBUG
1290 error = xfs_btree_check_block(cur, block, lev, bp);
1291 if (error)
1292 goto error0;
1293 #endif
1295 if (++cur->bc_ptrs[lev] <= xfs_btree_get_numrecs(block))
1296 break;
1298 /* Read-ahead the right block for the next loop. */
1299 xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA);
1303 * If we went off the root then we are either seriously
1304 * confused or have the tree root in an inode.
1306 if (lev == cur->bc_nlevels) {
1307 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1308 goto out0;
1309 ASSERT(0);
1310 error = EFSCORRUPTED;
1311 goto error0;
1313 ASSERT(lev < cur->bc_nlevels);
1316 * Now walk back down the tree, fixing up the cursor's buffer
1317 * pointers and key numbers.
1319 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1320 union xfs_btree_ptr *ptrp;
1322 ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1323 error = xfs_btree_read_buf_block(cur, ptrp, --lev,
1324 0, &block, &bp);
1325 if (error)
1326 goto error0;
1328 xfs_btree_setbuf(cur, lev, bp);
1329 cur->bc_ptrs[lev] = 1;
1331 out1:
1332 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1333 *stat = 1;
1334 return 0;
1336 out0:
1337 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1338 *stat = 0;
1339 return 0;
1341 error0:
1342 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1343 return error;
1347 * Decrement cursor by one record at the level.
1348 * For nonzero levels the leaf-ward information is untouched.
1350 int /* error */
1351 xfs_btree_decrement(
1352 struct xfs_btree_cur *cur,
1353 int level,
1354 int *stat) /* success/failure */
1356 struct xfs_btree_block *block;
1357 xfs_buf_t *bp;
1358 int error; /* error return value */
1359 int lev;
1360 union xfs_btree_ptr ptr;
1362 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1363 XFS_BTREE_TRACE_ARGI(cur, level);
1365 ASSERT(level < cur->bc_nlevels);
1367 /* Read-ahead to the left at this level. */
1368 xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA);
1370 /* We're done if we remain in the block after the decrement. */
1371 if (--cur->bc_ptrs[level] > 0)
1372 goto out1;
1374 /* Get a pointer to the btree block. */
1375 block = xfs_btree_get_block(cur, level, &bp);
1377 #ifdef DEBUG
1378 error = xfs_btree_check_block(cur, block, level, bp);
1379 if (error)
1380 goto error0;
1381 #endif
1383 /* Fail if we just went off the left edge of the tree. */
1384 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
1385 if (xfs_btree_ptr_is_null(cur, &ptr))
1386 goto out0;
1388 XFS_BTREE_STATS_INC(cur, decrement);
1391 * March up the tree decrementing pointers.
1392 * Stop when we don't go off the left edge of a block.
1394 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1395 if (--cur->bc_ptrs[lev] > 0)
1396 break;
1397 /* Read-ahead the left block for the next loop. */
1398 xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA);
1402 * If we went off the root then we are seriously confused.
1403 * or the root of the tree is in an inode.
1405 if (lev == cur->bc_nlevels) {
1406 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1407 goto out0;
1408 ASSERT(0);
1409 error = EFSCORRUPTED;
1410 goto error0;
1412 ASSERT(lev < cur->bc_nlevels);
1415 * Now walk back down the tree, fixing up the cursor's buffer
1416 * pointers and key numbers.
1418 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1419 union xfs_btree_ptr *ptrp;
1421 ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1422 error = xfs_btree_read_buf_block(cur, ptrp, --lev,
1423 0, &block, &bp);
1424 if (error)
1425 goto error0;
1426 xfs_btree_setbuf(cur, lev, bp);
1427 cur->bc_ptrs[lev] = xfs_btree_get_numrecs(block);
1429 out1:
1430 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1431 *stat = 1;
1432 return 0;
1434 out0:
1435 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1436 *stat = 0;
1437 return 0;
1439 error0:
1440 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1441 return error;
1444 STATIC int
1445 xfs_btree_lookup_get_block(
1446 struct xfs_btree_cur *cur, /* btree cursor */
1447 int level, /* level in the btree */
1448 union xfs_btree_ptr *pp, /* ptr to btree block */
1449 struct xfs_btree_block **blkp) /* return btree block */
1451 struct xfs_buf *bp; /* buffer pointer for btree block */
1452 int error = 0;
1454 /* special case the root block if in an inode */
1455 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1456 (level == cur->bc_nlevels - 1)) {
1457 *blkp = xfs_btree_get_iroot(cur);
1458 return 0;
1462 * If the old buffer at this level for the disk address we are
1463 * looking for re-use it.
1465 * Otherwise throw it away and get a new one.
1467 bp = cur->bc_bufs[level];
1468 if (bp && XFS_BUF_ADDR(bp) == xfs_btree_ptr_to_daddr(cur, pp)) {
1469 *blkp = XFS_BUF_TO_BLOCK(bp);
1470 return 0;
1473 error = xfs_btree_read_buf_block(cur, pp, level, 0, blkp, &bp);
1474 if (error)
1475 return error;
1477 xfs_btree_setbuf(cur, level, bp);
1478 return 0;
1482 * Get current search key. For level 0 we don't actually have a key
1483 * structure so we make one up from the record. For all other levels
1484 * we just return the right key.
1486 STATIC union xfs_btree_key *
1487 xfs_lookup_get_search_key(
1488 struct xfs_btree_cur *cur,
1489 int level,
1490 int keyno,
1491 struct xfs_btree_block *block,
1492 union xfs_btree_key *kp)
1494 if (level == 0) {
1495 cur->bc_ops->init_key_from_rec(kp,
1496 xfs_btree_rec_addr(cur, keyno, block));
1497 return kp;
1500 return xfs_btree_key_addr(cur, keyno, block);
1504 * Lookup the record. The cursor is made to point to it, based on dir.
1505 * Return 0 if can't find any such record, 1 for success.
1507 int /* error */
1508 xfs_btree_lookup(
1509 struct xfs_btree_cur *cur, /* btree cursor */
1510 xfs_lookup_t dir, /* <=, ==, or >= */
1511 int *stat) /* success/failure */
1513 struct xfs_btree_block *block; /* current btree block */
1514 __int64_t diff; /* difference for the current key */
1515 int error; /* error return value */
1516 int keyno; /* current key number */
1517 int level; /* level in the btree */
1518 union xfs_btree_ptr *pp; /* ptr to btree block */
1519 union xfs_btree_ptr ptr; /* ptr to btree block */
1521 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1522 XFS_BTREE_TRACE_ARGI(cur, dir);
1524 XFS_BTREE_STATS_INC(cur, lookup);
1526 block = NULL;
1527 keyno = 0;
1529 /* initialise start pointer from cursor */
1530 cur->bc_ops->init_ptr_from_cur(cur, &ptr);
1531 pp = &ptr;
1534 * Iterate over each level in the btree, starting at the root.
1535 * For each level above the leaves, find the key we need, based
1536 * on the lookup record, then follow the corresponding block
1537 * pointer down to the next level.
1539 for (level = cur->bc_nlevels - 1, diff = 1; level >= 0; level--) {
1540 /* Get the block we need to do the lookup on. */
1541 error = xfs_btree_lookup_get_block(cur, level, pp, &block);
1542 if (error)
1543 goto error0;
1545 if (diff == 0) {
1547 * If we already had a key match at a higher level, we
1548 * know we need to use the first entry in this block.
1550 keyno = 1;
1551 } else {
1552 /* Otherwise search this block. Do a binary search. */
1554 int high; /* high entry number */
1555 int low; /* low entry number */
1557 /* Set low and high entry numbers, 1-based. */
1558 low = 1;
1559 high = xfs_btree_get_numrecs(block);
1560 if (!high) {
1561 /* Block is empty, must be an empty leaf. */
1562 ASSERT(level == 0 && cur->bc_nlevels == 1);
1564 cur->bc_ptrs[0] = dir != XFS_LOOKUP_LE;
1565 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1566 *stat = 0;
1567 return 0;
1570 /* Binary search the block. */
1571 while (low <= high) {
1572 union xfs_btree_key key;
1573 union xfs_btree_key *kp;
1575 XFS_BTREE_STATS_INC(cur, compare);
1577 /* keyno is average of low and high. */
1578 keyno = (low + high) >> 1;
1580 /* Get current search key */
1581 kp = xfs_lookup_get_search_key(cur, level,
1582 keyno, block, &key);
1585 * Compute difference to get next direction:
1586 * - less than, move right
1587 * - greater than, move left
1588 * - equal, we're done
1590 diff = cur->bc_ops->key_diff(cur, kp);
1591 if (diff < 0)
1592 low = keyno + 1;
1593 else if (diff > 0)
1594 high = keyno - 1;
1595 else
1596 break;
1601 * If there are more levels, set up for the next level
1602 * by getting the block number and filling in the cursor.
1604 if (level > 0) {
1606 * If we moved left, need the previous key number,
1607 * unless there isn't one.
1609 if (diff > 0 && --keyno < 1)
1610 keyno = 1;
1611 pp = xfs_btree_ptr_addr(cur, keyno, block);
1613 #ifdef DEBUG
1614 error = xfs_btree_check_ptr(cur, pp, 0, level);
1615 if (error)
1616 goto error0;
1617 #endif
1618 cur->bc_ptrs[level] = keyno;
1622 /* Done with the search. See if we need to adjust the results. */
1623 if (dir != XFS_LOOKUP_LE && diff < 0) {
1624 keyno++;
1626 * If ge search and we went off the end of the block, but it's
1627 * not the last block, we're in the wrong block.
1629 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1630 if (dir == XFS_LOOKUP_GE &&
1631 keyno > xfs_btree_get_numrecs(block) &&
1632 !xfs_btree_ptr_is_null(cur, &ptr)) {
1633 int i;
1635 cur->bc_ptrs[0] = keyno;
1636 error = xfs_btree_increment(cur, 0, &i);
1637 if (error)
1638 goto error0;
1639 XFS_WANT_CORRUPTED_RETURN(i == 1);
1640 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1641 *stat = 1;
1642 return 0;
1644 } else if (dir == XFS_LOOKUP_LE && diff > 0)
1645 keyno--;
1646 cur->bc_ptrs[0] = keyno;
1648 /* Return if we succeeded or not. */
1649 if (keyno == 0 || keyno > xfs_btree_get_numrecs(block))
1650 *stat = 0;
1651 else if (dir != XFS_LOOKUP_EQ || diff == 0)
1652 *stat = 1;
1653 else
1654 *stat = 0;
1655 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1656 return 0;
1658 error0:
1659 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1660 return error;
1664 * Update keys at all levels from here to the root along the cursor's path.
1666 STATIC int
1667 xfs_btree_updkey(
1668 struct xfs_btree_cur *cur,
1669 union xfs_btree_key *keyp,
1670 int level)
1672 struct xfs_btree_block *block;
1673 struct xfs_buf *bp;
1674 union xfs_btree_key *kp;
1675 int ptr;
1677 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1678 XFS_BTREE_TRACE_ARGIK(cur, level, keyp);
1680 ASSERT(!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) || level >= 1);
1683 * Go up the tree from this level toward the root.
1684 * At each level, update the key value to the value input.
1685 * Stop when we reach a level where the cursor isn't pointing
1686 * at the first entry in the block.
1688 for (ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) {
1689 #ifdef DEBUG
1690 int error;
1691 #endif
1692 block = xfs_btree_get_block(cur, level, &bp);
1693 #ifdef DEBUG
1694 error = xfs_btree_check_block(cur, block, level, bp);
1695 if (error) {
1696 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1697 return error;
1699 #endif
1700 ptr = cur->bc_ptrs[level];
1701 kp = xfs_btree_key_addr(cur, ptr, block);
1702 xfs_btree_copy_keys(cur, kp, keyp, 1);
1703 xfs_btree_log_keys(cur, bp, ptr, ptr);
1706 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1707 return 0;
1711 * Update the record referred to by cur to the value in the
1712 * given record. This either works (return 0) or gets an
1713 * EFSCORRUPTED error.
1716 xfs_btree_update(
1717 struct xfs_btree_cur *cur,
1718 union xfs_btree_rec *rec)
1720 struct xfs_btree_block *block;
1721 struct xfs_buf *bp;
1722 int error;
1723 int ptr;
1724 union xfs_btree_rec *rp;
1726 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1727 XFS_BTREE_TRACE_ARGR(cur, rec);
1729 /* Pick up the current block. */
1730 block = xfs_btree_get_block(cur, 0, &bp);
1732 #ifdef DEBUG
1733 error = xfs_btree_check_block(cur, block, 0, bp);
1734 if (error)
1735 goto error0;
1736 #endif
1737 /* Get the address of the rec to be updated. */
1738 ptr = cur->bc_ptrs[0];
1739 rp = xfs_btree_rec_addr(cur, ptr, block);
1741 /* Fill in the new contents and log them. */
1742 xfs_btree_copy_recs(cur, rp, rec, 1);
1743 xfs_btree_log_recs(cur, bp, ptr, ptr);
1746 * If we are tracking the last record in the tree and
1747 * we are at the far right edge of the tree, update it.
1749 if (xfs_btree_is_lastrec(cur, block, 0)) {
1750 cur->bc_ops->update_lastrec(cur, block, rec,
1751 ptr, LASTREC_UPDATE);
1754 /* Updating first rec in leaf. Pass new key value up to our parent. */
1755 if (ptr == 1) {
1756 union xfs_btree_key key;
1758 cur->bc_ops->init_key_from_rec(&key, rec);
1759 error = xfs_btree_updkey(cur, &key, 1);
1760 if (error)
1761 goto error0;
1764 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1765 return 0;
1767 error0:
1768 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1769 return error;
1773 * Move 1 record left from cur/level if possible.
1774 * Update cur to reflect the new path.
1776 STATIC int /* error */
1777 xfs_btree_lshift(
1778 struct xfs_btree_cur *cur,
1779 int level,
1780 int *stat) /* success/failure */
1782 union xfs_btree_key key; /* btree key */
1783 struct xfs_buf *lbp; /* left buffer pointer */
1784 struct xfs_btree_block *left; /* left btree block */
1785 int lrecs; /* left record count */
1786 struct xfs_buf *rbp; /* right buffer pointer */
1787 struct xfs_btree_block *right; /* right btree block */
1788 int rrecs; /* right record count */
1789 union xfs_btree_ptr lptr; /* left btree pointer */
1790 union xfs_btree_key *rkp = NULL; /* right btree key */
1791 union xfs_btree_ptr *rpp = NULL; /* right address pointer */
1792 union xfs_btree_rec *rrp = NULL; /* right record pointer */
1793 int error; /* error return value */
1795 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1796 XFS_BTREE_TRACE_ARGI(cur, level);
1798 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1799 level == cur->bc_nlevels - 1)
1800 goto out0;
1802 /* Set up variables for this block as "right". */
1803 right = xfs_btree_get_block(cur, level, &rbp);
1805 #ifdef DEBUG
1806 error = xfs_btree_check_block(cur, right, level, rbp);
1807 if (error)
1808 goto error0;
1809 #endif
1811 /* If we've got no left sibling then we can't shift an entry left. */
1812 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
1813 if (xfs_btree_ptr_is_null(cur, &lptr))
1814 goto out0;
1817 * If the cursor entry is the one that would be moved, don't
1818 * do it... it's too complicated.
1820 if (cur->bc_ptrs[level] <= 1)
1821 goto out0;
1823 /* Set up the left neighbor as "left". */
1824 error = xfs_btree_read_buf_block(cur, &lptr, level, 0, &left, &lbp);
1825 if (error)
1826 goto error0;
1828 /* If it's full, it can't take another entry. */
1829 lrecs = xfs_btree_get_numrecs(left);
1830 if (lrecs == cur->bc_ops->get_maxrecs(cur, level))
1831 goto out0;
1833 rrecs = xfs_btree_get_numrecs(right);
1836 * We add one entry to the left side and remove one for the right side.
1837 * Account for it here, the changes will be updated on disk and logged
1838 * later.
1840 lrecs++;
1841 rrecs--;
1843 XFS_BTREE_STATS_INC(cur, lshift);
1844 XFS_BTREE_STATS_ADD(cur, moves, 1);
1847 * If non-leaf, copy a key and a ptr to the left block.
1848 * Log the changes to the left block.
1850 if (level > 0) {
1851 /* It's a non-leaf. Move keys and pointers. */
1852 union xfs_btree_key *lkp; /* left btree key */
1853 union xfs_btree_ptr *lpp; /* left address pointer */
1855 lkp = xfs_btree_key_addr(cur, lrecs, left);
1856 rkp = xfs_btree_key_addr(cur, 1, right);
1858 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
1859 rpp = xfs_btree_ptr_addr(cur, 1, right);
1860 #ifdef DEBUG
1861 error = xfs_btree_check_ptr(cur, rpp, 0, level);
1862 if (error)
1863 goto error0;
1864 #endif
1865 xfs_btree_copy_keys(cur, lkp, rkp, 1);
1866 xfs_btree_copy_ptrs(cur, lpp, rpp, 1);
1868 xfs_btree_log_keys(cur, lbp, lrecs, lrecs);
1869 xfs_btree_log_ptrs(cur, lbp, lrecs, lrecs);
1871 ASSERT(cur->bc_ops->keys_inorder(cur,
1872 xfs_btree_key_addr(cur, lrecs - 1, left), lkp));
1873 } else {
1874 /* It's a leaf. Move records. */
1875 union xfs_btree_rec *lrp; /* left record pointer */
1877 lrp = xfs_btree_rec_addr(cur, lrecs, left);
1878 rrp = xfs_btree_rec_addr(cur, 1, right);
1880 xfs_btree_copy_recs(cur, lrp, rrp, 1);
1881 xfs_btree_log_recs(cur, lbp, lrecs, lrecs);
1883 ASSERT(cur->bc_ops->recs_inorder(cur,
1884 xfs_btree_rec_addr(cur, lrecs - 1, left), lrp));
1887 xfs_btree_set_numrecs(left, lrecs);
1888 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
1890 xfs_btree_set_numrecs(right, rrecs);
1891 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
1894 * Slide the contents of right down one entry.
1896 XFS_BTREE_STATS_ADD(cur, moves, rrecs - 1);
1897 if (level > 0) {
1898 /* It's a nonleaf. operate on keys and ptrs */
1899 #ifdef DEBUG
1900 int i; /* loop index */
1902 for (i = 0; i < rrecs; i++) {
1903 error = xfs_btree_check_ptr(cur, rpp, i + 1, level);
1904 if (error)
1905 goto error0;
1907 #endif
1908 xfs_btree_shift_keys(cur,
1909 xfs_btree_key_addr(cur, 2, right),
1910 -1, rrecs);
1911 xfs_btree_shift_ptrs(cur,
1912 xfs_btree_ptr_addr(cur, 2, right),
1913 -1, rrecs);
1915 xfs_btree_log_keys(cur, rbp, 1, rrecs);
1916 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
1917 } else {
1918 /* It's a leaf. operate on records */
1919 xfs_btree_shift_recs(cur,
1920 xfs_btree_rec_addr(cur, 2, right),
1921 -1, rrecs);
1922 xfs_btree_log_recs(cur, rbp, 1, rrecs);
1925 * If it's the first record in the block, we'll need a key
1926 * structure to pass up to the next level (updkey).
1928 cur->bc_ops->init_key_from_rec(&key,
1929 xfs_btree_rec_addr(cur, 1, right));
1930 rkp = &key;
1933 /* Update the parent key values of right. */
1934 error = xfs_btree_updkey(cur, rkp, level + 1);
1935 if (error)
1936 goto error0;
1938 /* Slide the cursor value left one. */
1939 cur->bc_ptrs[level]--;
1941 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1942 *stat = 1;
1943 return 0;
1945 out0:
1946 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1947 *stat = 0;
1948 return 0;
1950 error0:
1951 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1952 return error;
1956 * Move 1 record right from cur/level if possible.
1957 * Update cur to reflect the new path.
1959 STATIC int /* error */
1960 xfs_btree_rshift(
1961 struct xfs_btree_cur *cur,
1962 int level,
1963 int *stat) /* success/failure */
1965 union xfs_btree_key key; /* btree key */
1966 struct xfs_buf *lbp; /* left buffer pointer */
1967 struct xfs_btree_block *left; /* left btree block */
1968 struct xfs_buf *rbp; /* right buffer pointer */
1969 struct xfs_btree_block *right; /* right btree block */
1970 struct xfs_btree_cur *tcur; /* temporary btree cursor */
1971 union xfs_btree_ptr rptr; /* right block pointer */
1972 union xfs_btree_key *rkp; /* right btree key */
1973 int rrecs; /* right record count */
1974 int lrecs; /* left record count */
1975 int error; /* error return value */
1976 int i; /* loop counter */
1978 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1979 XFS_BTREE_TRACE_ARGI(cur, level);
1981 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1982 (level == cur->bc_nlevels - 1))
1983 goto out0;
1985 /* Set up variables for this block as "left". */
1986 left = xfs_btree_get_block(cur, level, &lbp);
1988 #ifdef DEBUG
1989 error = xfs_btree_check_block(cur, left, level, lbp);
1990 if (error)
1991 goto error0;
1992 #endif
1994 /* If we've got no right sibling then we can't shift an entry right. */
1995 xfs_btree_get_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
1996 if (xfs_btree_ptr_is_null(cur, &rptr))
1997 goto out0;
2000 * If the cursor entry is the one that would be moved, don't
2001 * do it... it's too complicated.
2003 lrecs = xfs_btree_get_numrecs(left);
2004 if (cur->bc_ptrs[level] >= lrecs)
2005 goto out0;
2007 /* Set up the right neighbor as "right". */
2008 error = xfs_btree_read_buf_block(cur, &rptr, level, 0, &right, &rbp);
2009 if (error)
2010 goto error0;
2012 /* If it's full, it can't take another entry. */
2013 rrecs = xfs_btree_get_numrecs(right);
2014 if (rrecs == cur->bc_ops->get_maxrecs(cur, level))
2015 goto out0;
2017 XFS_BTREE_STATS_INC(cur, rshift);
2018 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2021 * Make a hole at the start of the right neighbor block, then
2022 * copy the last left block entry to the hole.
2024 if (level > 0) {
2025 /* It's a nonleaf. make a hole in the keys and ptrs */
2026 union xfs_btree_key *lkp;
2027 union xfs_btree_ptr *lpp;
2028 union xfs_btree_ptr *rpp;
2030 lkp = xfs_btree_key_addr(cur, lrecs, left);
2031 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2032 rkp = xfs_btree_key_addr(cur, 1, right);
2033 rpp = xfs_btree_ptr_addr(cur, 1, right);
2035 #ifdef DEBUG
2036 for (i = rrecs - 1; i >= 0; i--) {
2037 error = xfs_btree_check_ptr(cur, rpp, i, level);
2038 if (error)
2039 goto error0;
2041 #endif
2043 xfs_btree_shift_keys(cur, rkp, 1, rrecs);
2044 xfs_btree_shift_ptrs(cur, rpp, 1, rrecs);
2046 #ifdef DEBUG
2047 error = xfs_btree_check_ptr(cur, lpp, 0, level);
2048 if (error)
2049 goto error0;
2050 #endif
2052 /* Now put the new data in, and log it. */
2053 xfs_btree_copy_keys(cur, rkp, lkp, 1);
2054 xfs_btree_copy_ptrs(cur, rpp, lpp, 1);
2056 xfs_btree_log_keys(cur, rbp, 1, rrecs + 1);
2057 xfs_btree_log_ptrs(cur, rbp, 1, rrecs + 1);
2059 ASSERT(cur->bc_ops->keys_inorder(cur, rkp,
2060 xfs_btree_key_addr(cur, 2, right)));
2061 } else {
2062 /* It's a leaf. make a hole in the records */
2063 union xfs_btree_rec *lrp;
2064 union xfs_btree_rec *rrp;
2066 lrp = xfs_btree_rec_addr(cur, lrecs, left);
2067 rrp = xfs_btree_rec_addr(cur, 1, right);
2069 xfs_btree_shift_recs(cur, rrp, 1, rrecs);
2071 /* Now put the new data in, and log it. */
2072 xfs_btree_copy_recs(cur, rrp, lrp, 1);
2073 xfs_btree_log_recs(cur, rbp, 1, rrecs + 1);
2075 cur->bc_ops->init_key_from_rec(&key, rrp);
2076 rkp = &key;
2078 ASSERT(cur->bc_ops->recs_inorder(cur, rrp,
2079 xfs_btree_rec_addr(cur, 2, right)));
2083 * Decrement and log left's numrecs, bump and log right's numrecs.
2085 xfs_btree_set_numrecs(left, --lrecs);
2086 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2088 xfs_btree_set_numrecs(right, ++rrecs);
2089 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2092 * Using a temporary cursor, update the parent key values of the
2093 * block on the right.
2095 error = xfs_btree_dup_cursor(cur, &tcur);
2096 if (error)
2097 goto error0;
2098 i = xfs_btree_lastrec(tcur, level);
2099 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
2101 error = xfs_btree_increment(tcur, level, &i);
2102 if (error)
2103 goto error1;
2105 error = xfs_btree_updkey(tcur, rkp, level + 1);
2106 if (error)
2107 goto error1;
2109 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
2111 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2112 *stat = 1;
2113 return 0;
2115 out0:
2116 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2117 *stat = 0;
2118 return 0;
2120 error0:
2121 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2122 return error;
2124 error1:
2125 XFS_BTREE_TRACE_CURSOR(tcur, XBT_ERROR);
2126 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
2127 return error;
2131 * Split cur/level block in half.
2132 * Return new block number and the key to its first
2133 * record (to be inserted into parent).
2135 STATIC int /* error */
2136 xfs_btree_split(
2137 struct xfs_btree_cur *cur,
2138 int level,
2139 union xfs_btree_ptr *ptrp,
2140 union xfs_btree_key *key,
2141 struct xfs_btree_cur **curp,
2142 int *stat) /* success/failure */
2144 union xfs_btree_ptr lptr; /* left sibling block ptr */
2145 struct xfs_buf *lbp; /* left buffer pointer */
2146 struct xfs_btree_block *left; /* left btree block */
2147 union xfs_btree_ptr rptr; /* right sibling block ptr */
2148 struct xfs_buf *rbp; /* right buffer pointer */
2149 struct xfs_btree_block *right; /* right btree block */
2150 union xfs_btree_ptr rrptr; /* right-right sibling ptr */
2151 struct xfs_buf *rrbp; /* right-right buffer pointer */
2152 struct xfs_btree_block *rrblock; /* right-right btree block */
2153 int lrecs;
2154 int rrecs;
2155 int src_index;
2156 int error; /* error return value */
2157 #ifdef DEBUG
2158 int i;
2159 #endif
2161 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2162 XFS_BTREE_TRACE_ARGIPK(cur, level, *ptrp, key);
2164 XFS_BTREE_STATS_INC(cur, split);
2166 /* Set up left block (current one). */
2167 left = xfs_btree_get_block(cur, level, &lbp);
2169 #ifdef DEBUG
2170 error = xfs_btree_check_block(cur, left, level, lbp);
2171 if (error)
2172 goto error0;
2173 #endif
2175 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2177 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2178 error = cur->bc_ops->alloc_block(cur, &lptr, &rptr, 1, stat);
2179 if (error)
2180 goto error0;
2181 if (*stat == 0)
2182 goto out0;
2183 XFS_BTREE_STATS_INC(cur, alloc);
2185 /* Set up the new block as "right". */
2186 error = xfs_btree_get_buf_block(cur, &rptr, 0, &right, &rbp);
2187 if (error)
2188 goto error0;
2190 /* Fill in the btree header for the new right block. */
2191 xfs_btree_init_block(cur, xfs_btree_get_level(left), 0, right);
2194 * Split the entries between the old and the new block evenly.
2195 * Make sure that if there's an odd number of entries now, that
2196 * each new block will have the same number of entries.
2198 lrecs = xfs_btree_get_numrecs(left);
2199 rrecs = lrecs / 2;
2200 if ((lrecs & 1) && cur->bc_ptrs[level] <= rrecs + 1)
2201 rrecs++;
2202 src_index = (lrecs - rrecs + 1);
2204 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2207 * Copy btree block entries from the left block over to the
2208 * new block, the right. Update the right block and log the
2209 * changes.
2211 if (level > 0) {
2212 /* It's a non-leaf. Move keys and pointers. */
2213 union xfs_btree_key *lkp; /* left btree key */
2214 union xfs_btree_ptr *lpp; /* left address pointer */
2215 union xfs_btree_key *rkp; /* right btree key */
2216 union xfs_btree_ptr *rpp; /* right address pointer */
2218 lkp = xfs_btree_key_addr(cur, src_index, left);
2219 lpp = xfs_btree_ptr_addr(cur, src_index, left);
2220 rkp = xfs_btree_key_addr(cur, 1, right);
2221 rpp = xfs_btree_ptr_addr(cur, 1, right);
2223 #ifdef DEBUG
2224 for (i = src_index; i < rrecs; i++) {
2225 error = xfs_btree_check_ptr(cur, lpp, i, level);
2226 if (error)
2227 goto error0;
2229 #endif
2231 xfs_btree_copy_keys(cur, rkp, lkp, rrecs);
2232 xfs_btree_copy_ptrs(cur, rpp, lpp, rrecs);
2234 xfs_btree_log_keys(cur, rbp, 1, rrecs);
2235 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2237 /* Grab the keys to the entries moved to the right block */
2238 xfs_btree_copy_keys(cur, key, rkp, 1);
2239 } else {
2240 /* It's a leaf. Move records. */
2241 union xfs_btree_rec *lrp; /* left record pointer */
2242 union xfs_btree_rec *rrp; /* right record pointer */
2244 lrp = xfs_btree_rec_addr(cur, src_index, left);
2245 rrp = xfs_btree_rec_addr(cur, 1, right);
2247 xfs_btree_copy_recs(cur, rrp, lrp, rrecs);
2248 xfs_btree_log_recs(cur, rbp, 1, rrecs);
2250 cur->bc_ops->init_key_from_rec(key,
2251 xfs_btree_rec_addr(cur, 1, right));
2256 * Find the left block number by looking in the buffer.
2257 * Adjust numrecs, sibling pointers.
2259 xfs_btree_get_sibling(cur, left, &rrptr, XFS_BB_RIGHTSIB);
2260 xfs_btree_set_sibling(cur, right, &rrptr, XFS_BB_RIGHTSIB);
2261 xfs_btree_set_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2262 xfs_btree_set_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2264 lrecs -= rrecs;
2265 xfs_btree_set_numrecs(left, lrecs);
2266 xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs);
2268 xfs_btree_log_block(cur, rbp, XFS_BB_ALL_BITS);
2269 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
2272 * If there's a block to the new block's right, make that block
2273 * point back to right instead of to left.
2275 if (!xfs_btree_ptr_is_null(cur, &rrptr)) {
2276 error = xfs_btree_read_buf_block(cur, &rrptr, level,
2277 0, &rrblock, &rrbp);
2278 if (error)
2279 goto error0;
2280 xfs_btree_set_sibling(cur, rrblock, &rptr, XFS_BB_LEFTSIB);
2281 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
2284 * If the cursor is really in the right block, move it there.
2285 * If it's just pointing past the last entry in left, then we'll
2286 * insert there, so don't change anything in that case.
2288 if (cur->bc_ptrs[level] > lrecs + 1) {
2289 xfs_btree_setbuf(cur, level, rbp);
2290 cur->bc_ptrs[level] -= lrecs;
2293 * If there are more levels, we'll need another cursor which refers
2294 * the right block, no matter where this cursor was.
2296 if (level + 1 < cur->bc_nlevels) {
2297 error = xfs_btree_dup_cursor(cur, curp);
2298 if (error)
2299 goto error0;
2300 (*curp)->bc_ptrs[level + 1]++;
2302 *ptrp = rptr;
2303 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2304 *stat = 1;
2305 return 0;
2306 out0:
2307 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2308 *stat = 0;
2309 return 0;
2311 error0:
2312 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2313 return error;
2317 * Copy the old inode root contents into a real block and make the
2318 * broot point to it.
2320 int /* error */
2321 xfs_btree_new_iroot(
2322 struct xfs_btree_cur *cur, /* btree cursor */
2323 int *logflags, /* logging flags for inode */
2324 int *stat) /* return status - 0 fail */
2326 struct xfs_buf *cbp; /* buffer for cblock */
2327 struct xfs_btree_block *block; /* btree block */
2328 struct xfs_btree_block *cblock; /* child btree block */
2329 union xfs_btree_key *ckp; /* child key pointer */
2330 union xfs_btree_ptr *cpp; /* child ptr pointer */
2331 union xfs_btree_key *kp; /* pointer to btree key */
2332 union xfs_btree_ptr *pp; /* pointer to block addr */
2333 union xfs_btree_ptr nptr; /* new block addr */
2334 int level; /* btree level */
2335 int error; /* error return code */
2336 #ifdef DEBUG
2337 int i; /* loop counter */
2338 #endif
2340 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2341 XFS_BTREE_STATS_INC(cur, newroot);
2343 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
2345 level = cur->bc_nlevels - 1;
2347 block = xfs_btree_get_iroot(cur);
2348 pp = xfs_btree_ptr_addr(cur, 1, block);
2350 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2351 error = cur->bc_ops->alloc_block(cur, pp, &nptr, 1, stat);
2352 if (error)
2353 goto error0;
2354 if (*stat == 0) {
2355 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2356 return 0;
2358 XFS_BTREE_STATS_INC(cur, alloc);
2360 /* Copy the root into a real block. */
2361 error = xfs_btree_get_buf_block(cur, &nptr, 0, &cblock, &cbp);
2362 if (error)
2363 goto error0;
2365 memcpy(cblock, block, xfs_btree_block_len(cur));
2367 be16_add_cpu(&block->bb_level, 1);
2368 xfs_btree_set_numrecs(block, 1);
2369 cur->bc_nlevels++;
2370 cur->bc_ptrs[level + 1] = 1;
2372 kp = xfs_btree_key_addr(cur, 1, block);
2373 ckp = xfs_btree_key_addr(cur, 1, cblock);
2374 xfs_btree_copy_keys(cur, ckp, kp, xfs_btree_get_numrecs(cblock));
2376 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
2377 #ifdef DEBUG
2378 for (i = 0; i < be16_to_cpu(cblock->bb_numrecs); i++) {
2379 error = xfs_btree_check_ptr(cur, pp, i, level);
2380 if (error)
2381 goto error0;
2383 #endif
2384 xfs_btree_copy_ptrs(cur, cpp, pp, xfs_btree_get_numrecs(cblock));
2386 #ifdef DEBUG
2387 error = xfs_btree_check_ptr(cur, &nptr, 0, level);
2388 if (error)
2389 goto error0;
2390 #endif
2391 xfs_btree_copy_ptrs(cur, pp, &nptr, 1);
2393 xfs_iroot_realloc(cur->bc_private.b.ip,
2394 1 - xfs_btree_get_numrecs(cblock),
2395 cur->bc_private.b.whichfork);
2397 xfs_btree_setbuf(cur, level, cbp);
2400 * Do all this logging at the end so that
2401 * the root is at the right level.
2403 xfs_btree_log_block(cur, cbp, XFS_BB_ALL_BITS);
2404 xfs_btree_log_keys(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
2405 xfs_btree_log_ptrs(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
2407 *logflags |=
2408 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork);
2409 *stat = 1;
2410 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2411 return 0;
2412 error0:
2413 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2414 return error;
2418 * Allocate a new root block, fill it in.
2420 STATIC int /* error */
2421 xfs_btree_new_root(
2422 struct xfs_btree_cur *cur, /* btree cursor */
2423 int *stat) /* success/failure */
2425 struct xfs_btree_block *block; /* one half of the old root block */
2426 struct xfs_buf *bp; /* buffer containing block */
2427 int error; /* error return value */
2428 struct xfs_buf *lbp; /* left buffer pointer */
2429 struct xfs_btree_block *left; /* left btree block */
2430 struct xfs_buf *nbp; /* new (root) buffer */
2431 struct xfs_btree_block *new; /* new (root) btree block */
2432 int nptr; /* new value for key index, 1 or 2 */
2433 struct xfs_buf *rbp; /* right buffer pointer */
2434 struct xfs_btree_block *right; /* right btree block */
2435 union xfs_btree_ptr rptr;
2436 union xfs_btree_ptr lptr;
2438 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2439 XFS_BTREE_STATS_INC(cur, newroot);
2441 /* initialise our start point from the cursor */
2442 cur->bc_ops->init_ptr_from_cur(cur, &rptr);
2444 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2445 error = cur->bc_ops->alloc_block(cur, &rptr, &lptr, 1, stat);
2446 if (error)
2447 goto error0;
2448 if (*stat == 0)
2449 goto out0;
2450 XFS_BTREE_STATS_INC(cur, alloc);
2452 /* Set up the new block. */
2453 error = xfs_btree_get_buf_block(cur, &lptr, 0, &new, &nbp);
2454 if (error)
2455 goto error0;
2457 /* Set the root in the holding structure increasing the level by 1. */
2458 cur->bc_ops->set_root(cur, &lptr, 1);
2461 * At the previous root level there are now two blocks: the old root,
2462 * and the new block generated when it was split. We don't know which
2463 * one the cursor is pointing at, so we set up variables "left" and
2464 * "right" for each case.
2466 block = xfs_btree_get_block(cur, cur->bc_nlevels - 1, &bp);
2468 #ifdef DEBUG
2469 error = xfs_btree_check_block(cur, block, cur->bc_nlevels - 1, bp);
2470 if (error)
2471 goto error0;
2472 #endif
2474 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
2475 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
2476 /* Our block is left, pick up the right block. */
2477 lbp = bp;
2478 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2479 left = block;
2480 error = xfs_btree_read_buf_block(cur, &rptr,
2481 cur->bc_nlevels - 1, 0, &right, &rbp);
2482 if (error)
2483 goto error0;
2484 bp = rbp;
2485 nptr = 1;
2486 } else {
2487 /* Our block is right, pick up the left block. */
2488 rbp = bp;
2489 xfs_btree_buf_to_ptr(cur, rbp, &rptr);
2490 right = block;
2491 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2492 error = xfs_btree_read_buf_block(cur, &lptr,
2493 cur->bc_nlevels - 1, 0, &left, &lbp);
2494 if (error)
2495 goto error0;
2496 bp = lbp;
2497 nptr = 2;
2499 /* Fill in the new block's btree header and log it. */
2500 xfs_btree_init_block(cur, cur->bc_nlevels, 2, new);
2501 xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS);
2502 ASSERT(!xfs_btree_ptr_is_null(cur, &lptr) &&
2503 !xfs_btree_ptr_is_null(cur, &rptr));
2505 /* Fill in the key data in the new root. */
2506 if (xfs_btree_get_level(left) > 0) {
2507 xfs_btree_copy_keys(cur,
2508 xfs_btree_key_addr(cur, 1, new),
2509 xfs_btree_key_addr(cur, 1, left), 1);
2510 xfs_btree_copy_keys(cur,
2511 xfs_btree_key_addr(cur, 2, new),
2512 xfs_btree_key_addr(cur, 1, right), 1);
2513 } else {
2514 cur->bc_ops->init_key_from_rec(
2515 xfs_btree_key_addr(cur, 1, new),
2516 xfs_btree_rec_addr(cur, 1, left));
2517 cur->bc_ops->init_key_from_rec(
2518 xfs_btree_key_addr(cur, 2, new),
2519 xfs_btree_rec_addr(cur, 1, right));
2521 xfs_btree_log_keys(cur, nbp, 1, 2);
2523 /* Fill in the pointer data in the new root. */
2524 xfs_btree_copy_ptrs(cur,
2525 xfs_btree_ptr_addr(cur, 1, new), &lptr, 1);
2526 xfs_btree_copy_ptrs(cur,
2527 xfs_btree_ptr_addr(cur, 2, new), &rptr, 1);
2528 xfs_btree_log_ptrs(cur, nbp, 1, 2);
2530 /* Fix up the cursor. */
2531 xfs_btree_setbuf(cur, cur->bc_nlevels, nbp);
2532 cur->bc_ptrs[cur->bc_nlevels] = nptr;
2533 cur->bc_nlevels++;
2534 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2535 *stat = 1;
2536 return 0;
2537 error0:
2538 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2539 return error;
2540 out0:
2541 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2542 *stat = 0;
2543 return 0;
2546 STATIC int
2547 xfs_btree_make_block_unfull(
2548 struct xfs_btree_cur *cur, /* btree cursor */
2549 int level, /* btree level */
2550 int numrecs,/* # of recs in block */
2551 int *oindex,/* old tree index */
2552 int *index, /* new tree index */
2553 union xfs_btree_ptr *nptr, /* new btree ptr */
2554 struct xfs_btree_cur **ncur, /* new btree cursor */
2555 union xfs_btree_rec *nrec, /* new record */
2556 int *stat)
2558 union xfs_btree_key key; /* new btree key value */
2559 int error = 0;
2561 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2562 level == cur->bc_nlevels - 1) {
2563 struct xfs_inode *ip = cur->bc_private.b.ip;
2565 if (numrecs < cur->bc_ops->get_dmaxrecs(cur, level)) {
2566 /* A root block that can be made bigger. */
2568 xfs_iroot_realloc(ip, 1, cur->bc_private.b.whichfork);
2569 } else {
2570 /* A root block that needs replacing */
2571 int logflags = 0;
2573 error = xfs_btree_new_iroot(cur, &logflags, stat);
2574 if (error || *stat == 0)
2575 return error;
2577 xfs_trans_log_inode(cur->bc_tp, ip, logflags);
2580 return 0;
2583 /* First, try shifting an entry to the right neighbor. */
2584 error = xfs_btree_rshift(cur, level, stat);
2585 if (error || *stat)
2586 return error;
2588 /* Next, try shifting an entry to the left neighbor. */
2589 error = xfs_btree_lshift(cur, level, stat);
2590 if (error)
2591 return error;
2593 if (*stat) {
2594 *oindex = *index = cur->bc_ptrs[level];
2595 return 0;
2599 * Next, try splitting the current block in half.
2601 * If this works we have to re-set our variables because we
2602 * could be in a different block now.
2604 error = xfs_btree_split(cur, level, nptr, &key, ncur, stat);
2605 if (error || *stat == 0)
2606 return error;
2609 *index = cur->bc_ptrs[level];
2610 cur->bc_ops->init_rec_from_key(&key, nrec);
2611 return 0;
2615 * Insert one record/level. Return information to the caller
2616 * allowing the next level up to proceed if necessary.
2618 STATIC int
2619 xfs_btree_insrec(
2620 struct xfs_btree_cur *cur, /* btree cursor */
2621 int level, /* level to insert record at */
2622 union xfs_btree_ptr *ptrp, /* i/o: block number inserted */
2623 union xfs_btree_rec *recp, /* i/o: record data inserted */
2624 struct xfs_btree_cur **curp, /* output: new cursor replacing cur */
2625 int *stat) /* success/failure */
2627 struct xfs_btree_block *block; /* btree block */
2628 struct xfs_buf *bp; /* buffer for block */
2629 union xfs_btree_key key; /* btree key */
2630 union xfs_btree_ptr nptr; /* new block ptr */
2631 struct xfs_btree_cur *ncur; /* new btree cursor */
2632 union xfs_btree_rec nrec; /* new record count */
2633 int optr; /* old key/record index */
2634 int ptr; /* key/record index */
2635 int numrecs;/* number of records */
2636 int error; /* error return value */
2637 #ifdef DEBUG
2638 int i;
2639 #endif
2641 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2642 XFS_BTREE_TRACE_ARGIPR(cur, level, *ptrp, recp);
2644 ncur = NULL;
2647 * If we have an external root pointer, and we've made it to the
2648 * root level, allocate a new root block and we're done.
2650 if (!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2651 (level >= cur->bc_nlevels)) {
2652 error = xfs_btree_new_root(cur, stat);
2653 xfs_btree_set_ptr_null(cur, ptrp);
2655 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2656 return error;
2659 /* If we're off the left edge, return failure. */
2660 ptr = cur->bc_ptrs[level];
2661 if (ptr == 0) {
2662 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2663 *stat = 0;
2664 return 0;
2667 /* Make a key out of the record data to be inserted, and save it. */
2668 cur->bc_ops->init_key_from_rec(&key, recp);
2670 optr = ptr;
2672 XFS_BTREE_STATS_INC(cur, insrec);
2674 /* Get pointers to the btree buffer and block. */
2675 block = xfs_btree_get_block(cur, level, &bp);
2676 numrecs = xfs_btree_get_numrecs(block);
2678 #ifdef DEBUG
2679 error = xfs_btree_check_block(cur, block, level, bp);
2680 if (error)
2681 goto error0;
2683 /* Check that the new entry is being inserted in the right place. */
2684 if (ptr <= numrecs) {
2685 if (level == 0) {
2686 ASSERT(cur->bc_ops->recs_inorder(cur, recp,
2687 xfs_btree_rec_addr(cur, ptr, block)));
2688 } else {
2689 ASSERT(cur->bc_ops->keys_inorder(cur, &key,
2690 xfs_btree_key_addr(cur, ptr, block)));
2693 #endif
2696 * If the block is full, we can't insert the new entry until we
2697 * make the block un-full.
2699 xfs_btree_set_ptr_null(cur, &nptr);
2700 if (numrecs == cur->bc_ops->get_maxrecs(cur, level)) {
2701 error = xfs_btree_make_block_unfull(cur, level, numrecs,
2702 &optr, &ptr, &nptr, &ncur, &nrec, stat);
2703 if (error || *stat == 0)
2704 goto error0;
2708 * The current block may have changed if the block was
2709 * previously full and we have just made space in it.
2711 block = xfs_btree_get_block(cur, level, &bp);
2712 numrecs = xfs_btree_get_numrecs(block);
2714 #ifdef DEBUG
2715 error = xfs_btree_check_block(cur, block, level, bp);
2716 if (error)
2717 return error;
2718 #endif
2721 * At this point we know there's room for our new entry in the block
2722 * we're pointing at.
2724 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr + 1);
2726 if (level > 0) {
2727 /* It's a nonleaf. make a hole in the keys and ptrs */
2728 union xfs_btree_key *kp;
2729 union xfs_btree_ptr *pp;
2731 kp = xfs_btree_key_addr(cur, ptr, block);
2732 pp = xfs_btree_ptr_addr(cur, ptr, block);
2734 #ifdef DEBUG
2735 for (i = numrecs - ptr; i >= 0; i--) {
2736 error = xfs_btree_check_ptr(cur, pp, i, level);
2737 if (error)
2738 return error;
2740 #endif
2742 xfs_btree_shift_keys(cur, kp, 1, numrecs - ptr + 1);
2743 xfs_btree_shift_ptrs(cur, pp, 1, numrecs - ptr + 1);
2745 #ifdef DEBUG
2746 error = xfs_btree_check_ptr(cur, ptrp, 0, level);
2747 if (error)
2748 goto error0;
2749 #endif
2751 /* Now put the new data in, bump numrecs and log it. */
2752 xfs_btree_copy_keys(cur, kp, &key, 1);
2753 xfs_btree_copy_ptrs(cur, pp, ptrp, 1);
2754 numrecs++;
2755 xfs_btree_set_numrecs(block, numrecs);
2756 xfs_btree_log_ptrs(cur, bp, ptr, numrecs);
2757 xfs_btree_log_keys(cur, bp, ptr, numrecs);
2758 #ifdef DEBUG
2759 if (ptr < numrecs) {
2760 ASSERT(cur->bc_ops->keys_inorder(cur, kp,
2761 xfs_btree_key_addr(cur, ptr + 1, block)));
2763 #endif
2764 } else {
2765 /* It's a leaf. make a hole in the records */
2766 union xfs_btree_rec *rp;
2768 rp = xfs_btree_rec_addr(cur, ptr, block);
2770 xfs_btree_shift_recs(cur, rp, 1, numrecs - ptr + 1);
2772 /* Now put the new data in, bump numrecs and log it. */
2773 xfs_btree_copy_recs(cur, rp, recp, 1);
2774 xfs_btree_set_numrecs(block, ++numrecs);
2775 xfs_btree_log_recs(cur, bp, ptr, numrecs);
2776 #ifdef DEBUG
2777 if (ptr < numrecs) {
2778 ASSERT(cur->bc_ops->recs_inorder(cur, rp,
2779 xfs_btree_rec_addr(cur, ptr + 1, block)));
2781 #endif
2784 /* Log the new number of records in the btree header. */
2785 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
2787 /* If we inserted at the start of a block, update the parents' keys. */
2788 if (optr == 1) {
2789 error = xfs_btree_updkey(cur, &key, level + 1);
2790 if (error)
2791 goto error0;
2795 * If we are tracking the last record in the tree and
2796 * we are at the far right edge of the tree, update it.
2798 if (xfs_btree_is_lastrec(cur, block, level)) {
2799 cur->bc_ops->update_lastrec(cur, block, recp,
2800 ptr, LASTREC_INSREC);
2804 * Return the new block number, if any.
2805 * If there is one, give back a record value and a cursor too.
2807 *ptrp = nptr;
2808 if (!xfs_btree_ptr_is_null(cur, &nptr)) {
2809 *recp = nrec;
2810 *curp = ncur;
2813 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2814 *stat = 1;
2815 return 0;
2817 error0:
2818 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2819 return error;
2823 * Insert the record at the point referenced by cur.
2825 * A multi-level split of the tree on insert will invalidate the original
2826 * cursor. All callers of this function should assume that the cursor is
2827 * no longer valid and revalidate it.
2830 xfs_btree_insert(
2831 struct xfs_btree_cur *cur,
2832 int *stat)
2834 int error; /* error return value */
2835 int i; /* result value, 0 for failure */
2836 int level; /* current level number in btree */
2837 union xfs_btree_ptr nptr; /* new block number (split result) */
2838 struct xfs_btree_cur *ncur; /* new cursor (split result) */
2839 struct xfs_btree_cur *pcur; /* previous level's cursor */
2840 union xfs_btree_rec rec; /* record to insert */
2842 level = 0;
2843 ncur = NULL;
2844 pcur = cur;
2846 xfs_btree_set_ptr_null(cur, &nptr);
2847 cur->bc_ops->init_rec_from_cur(cur, &rec);
2850 * Loop going up the tree, starting at the leaf level.
2851 * Stop when we don't get a split block, that must mean that
2852 * the insert is finished with this level.
2854 do {
2856 * Insert nrec/nptr into this level of the tree.
2857 * Note if we fail, nptr will be null.
2859 error = xfs_btree_insrec(pcur, level, &nptr, &rec, &ncur, &i);
2860 if (error) {
2861 if (pcur != cur)
2862 xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR);
2863 goto error0;
2866 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
2867 level++;
2870 * See if the cursor we just used is trash.
2871 * Can't trash the caller's cursor, but otherwise we should
2872 * if ncur is a new cursor or we're about to be done.
2874 if (pcur != cur &&
2875 (ncur || xfs_btree_ptr_is_null(cur, &nptr))) {
2876 /* Save the state from the cursor before we trash it */
2877 if (cur->bc_ops->update_cursor)
2878 cur->bc_ops->update_cursor(pcur, cur);
2879 cur->bc_nlevels = pcur->bc_nlevels;
2880 xfs_btree_del_cursor(pcur, XFS_BTREE_NOERROR);
2882 /* If we got a new cursor, switch to it. */
2883 if (ncur) {
2884 pcur = ncur;
2885 ncur = NULL;
2887 } while (!xfs_btree_ptr_is_null(cur, &nptr));
2889 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2890 *stat = i;
2891 return 0;
2892 error0:
2893 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2894 return error;
2898 * Try to merge a non-leaf block back into the inode root.
2900 * Note: the killroot names comes from the fact that we're effectively
2901 * killing the old root block. But because we can't just delete the
2902 * inode we have to copy the single block it was pointing to into the
2903 * inode.
2905 STATIC int
2906 xfs_btree_kill_iroot(
2907 struct xfs_btree_cur *cur)
2909 int whichfork = cur->bc_private.b.whichfork;
2910 struct xfs_inode *ip = cur->bc_private.b.ip;
2911 struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork);
2912 struct xfs_btree_block *block;
2913 struct xfs_btree_block *cblock;
2914 union xfs_btree_key *kp;
2915 union xfs_btree_key *ckp;
2916 union xfs_btree_ptr *pp;
2917 union xfs_btree_ptr *cpp;
2918 struct xfs_buf *cbp;
2919 int level;
2920 int index;
2921 int numrecs;
2922 #ifdef DEBUG
2923 union xfs_btree_ptr ptr;
2924 int i;
2925 #endif
2927 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2929 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
2930 ASSERT(cur->bc_nlevels > 1);
2933 * Don't deal with the root block needs to be a leaf case.
2934 * We're just going to turn the thing back into extents anyway.
2936 level = cur->bc_nlevels - 1;
2937 if (level == 1)
2938 goto out0;
2941 * Give up if the root has multiple children.
2943 block = xfs_btree_get_iroot(cur);
2944 if (xfs_btree_get_numrecs(block) != 1)
2945 goto out0;
2947 cblock = xfs_btree_get_block(cur, level - 1, &cbp);
2948 numrecs = xfs_btree_get_numrecs(cblock);
2951 * Only do this if the next level will fit.
2952 * Then the data must be copied up to the inode,
2953 * instead of freeing the root you free the next level.
2955 if (numrecs > cur->bc_ops->get_dmaxrecs(cur, level))
2956 goto out0;
2958 XFS_BTREE_STATS_INC(cur, killroot);
2960 #ifdef DEBUG
2961 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
2962 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
2963 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
2964 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
2965 #endif
2967 index = numrecs - cur->bc_ops->get_maxrecs(cur, level);
2968 if (index) {
2969 xfs_iroot_realloc(cur->bc_private.b.ip, index,
2970 cur->bc_private.b.whichfork);
2971 block = ifp->if_broot;
2974 be16_add_cpu(&block->bb_numrecs, index);
2975 ASSERT(block->bb_numrecs == cblock->bb_numrecs);
2977 kp = xfs_btree_key_addr(cur, 1, block);
2978 ckp = xfs_btree_key_addr(cur, 1, cblock);
2979 xfs_btree_copy_keys(cur, kp, ckp, numrecs);
2981 pp = xfs_btree_ptr_addr(cur, 1, block);
2982 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
2983 #ifdef DEBUG
2984 for (i = 0; i < numrecs; i++) {
2985 int error;
2987 error = xfs_btree_check_ptr(cur, cpp, i, level - 1);
2988 if (error) {
2989 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2990 return error;
2993 #endif
2994 xfs_btree_copy_ptrs(cur, pp, cpp, numrecs);
2996 cur->bc_ops->free_block(cur, cbp);
2997 XFS_BTREE_STATS_INC(cur, free);
2999 cur->bc_bufs[level - 1] = NULL;
3000 be16_add_cpu(&block->bb_level, -1);
3001 xfs_trans_log_inode(cur->bc_tp, ip,
3002 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork));
3003 cur->bc_nlevels--;
3004 out0:
3005 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3006 return 0;
3010 * Kill the current root node, and replace it with it's only child node.
3012 STATIC int
3013 xfs_btree_kill_root(
3014 struct xfs_btree_cur *cur,
3015 struct xfs_buf *bp,
3016 int level,
3017 union xfs_btree_ptr *newroot)
3019 int error;
3021 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3022 XFS_BTREE_STATS_INC(cur, killroot);
3025 * Update the root pointer, decreasing the level by 1 and then
3026 * free the old root.
3028 cur->bc_ops->set_root(cur, newroot, -1);
3030 error = cur->bc_ops->free_block(cur, bp);
3031 if (error) {
3032 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3033 return error;
3036 XFS_BTREE_STATS_INC(cur, free);
3038 cur->bc_bufs[level] = NULL;
3039 cur->bc_ra[level] = 0;
3040 cur->bc_nlevels--;
3042 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3043 return 0;
3046 STATIC int
3047 xfs_btree_dec_cursor(
3048 struct xfs_btree_cur *cur,
3049 int level,
3050 int *stat)
3052 int error;
3053 int i;
3055 if (level > 0) {
3056 error = xfs_btree_decrement(cur, level, &i);
3057 if (error)
3058 return error;
3061 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3062 *stat = 1;
3063 return 0;
3067 * Single level of the btree record deletion routine.
3068 * Delete record pointed to by cur/level.
3069 * Remove the record from its block then rebalance the tree.
3070 * Return 0 for error, 1 for done, 2 to go on to the next level.
3072 STATIC int /* error */
3073 xfs_btree_delrec(
3074 struct xfs_btree_cur *cur, /* btree cursor */
3075 int level, /* level removing record from */
3076 int *stat) /* fail/done/go-on */
3078 struct xfs_btree_block *block; /* btree block */
3079 union xfs_btree_ptr cptr; /* current block ptr */
3080 struct xfs_buf *bp; /* buffer for block */
3081 int error; /* error return value */
3082 int i; /* loop counter */
3083 union xfs_btree_key key; /* storage for keyp */
3084 union xfs_btree_key *keyp = &key; /* passed to the next level */
3085 union xfs_btree_ptr lptr; /* left sibling block ptr */
3086 struct xfs_buf *lbp; /* left buffer pointer */
3087 struct xfs_btree_block *left; /* left btree block */
3088 int lrecs = 0; /* left record count */
3089 int ptr; /* key/record index */
3090 union xfs_btree_ptr rptr; /* right sibling block ptr */
3091 struct xfs_buf *rbp; /* right buffer pointer */
3092 struct xfs_btree_block *right; /* right btree block */
3093 struct xfs_btree_block *rrblock; /* right-right btree block */
3094 struct xfs_buf *rrbp; /* right-right buffer pointer */
3095 int rrecs = 0; /* right record count */
3096 struct xfs_btree_cur *tcur; /* temporary btree cursor */
3097 int numrecs; /* temporary numrec count */
3099 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3100 XFS_BTREE_TRACE_ARGI(cur, level);
3102 tcur = NULL;
3104 /* Get the index of the entry being deleted, check for nothing there. */
3105 ptr = cur->bc_ptrs[level];
3106 if (ptr == 0) {
3107 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3108 *stat = 0;
3109 return 0;
3112 /* Get the buffer & block containing the record or key/ptr. */
3113 block = xfs_btree_get_block(cur, level, &bp);
3114 numrecs = xfs_btree_get_numrecs(block);
3116 #ifdef DEBUG
3117 error = xfs_btree_check_block(cur, block, level, bp);
3118 if (error)
3119 goto error0;
3120 #endif
3122 /* Fail if we're off the end of the block. */
3123 if (ptr > numrecs) {
3124 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3125 *stat = 0;
3126 return 0;
3129 XFS_BTREE_STATS_INC(cur, delrec);
3130 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr);
3132 /* Excise the entries being deleted. */
3133 if (level > 0) {
3134 /* It's a nonleaf. operate on keys and ptrs */
3135 union xfs_btree_key *lkp;
3136 union xfs_btree_ptr *lpp;
3138 lkp = xfs_btree_key_addr(cur, ptr + 1, block);
3139 lpp = xfs_btree_ptr_addr(cur, ptr + 1, block);
3141 #ifdef DEBUG
3142 for (i = 0; i < numrecs - ptr; i++) {
3143 error = xfs_btree_check_ptr(cur, lpp, i, level);
3144 if (error)
3145 goto error0;
3147 #endif
3149 if (ptr < numrecs) {
3150 xfs_btree_shift_keys(cur, lkp, -1, numrecs - ptr);
3151 xfs_btree_shift_ptrs(cur, lpp, -1, numrecs - ptr);
3152 xfs_btree_log_keys(cur, bp, ptr, numrecs - 1);
3153 xfs_btree_log_ptrs(cur, bp, ptr, numrecs - 1);
3157 * If it's the first record in the block, we'll need to pass a
3158 * key up to the next level (updkey).
3160 if (ptr == 1)
3161 keyp = xfs_btree_key_addr(cur, 1, block);
3162 } else {
3163 /* It's a leaf. operate on records */
3164 if (ptr < numrecs) {
3165 xfs_btree_shift_recs(cur,
3166 xfs_btree_rec_addr(cur, ptr + 1, block),
3167 -1, numrecs - ptr);
3168 xfs_btree_log_recs(cur, bp, ptr, numrecs - 1);
3172 * If it's the first record in the block, we'll need a key
3173 * structure to pass up to the next level (updkey).
3175 if (ptr == 1) {
3176 cur->bc_ops->init_key_from_rec(&key,
3177 xfs_btree_rec_addr(cur, 1, block));
3178 keyp = &key;
3183 * Decrement and log the number of entries in the block.
3185 xfs_btree_set_numrecs(block, --numrecs);
3186 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
3189 * If we are tracking the last record in the tree and
3190 * we are at the far right edge of the tree, update it.
3192 if (xfs_btree_is_lastrec(cur, block, level)) {
3193 cur->bc_ops->update_lastrec(cur, block, NULL,
3194 ptr, LASTREC_DELREC);
3198 * We're at the root level. First, shrink the root block in-memory.
3199 * Try to get rid of the next level down. If we can't then there's
3200 * nothing left to do.
3202 if (level == cur->bc_nlevels - 1) {
3203 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3204 xfs_iroot_realloc(cur->bc_private.b.ip, -1,
3205 cur->bc_private.b.whichfork);
3207 error = xfs_btree_kill_iroot(cur);
3208 if (error)
3209 goto error0;
3211 error = xfs_btree_dec_cursor(cur, level, stat);
3212 if (error)
3213 goto error0;
3214 *stat = 1;
3215 return 0;
3219 * If this is the root level, and there's only one entry left,
3220 * and it's NOT the leaf level, then we can get rid of this
3221 * level.
3223 if (numrecs == 1 && level > 0) {
3224 union xfs_btree_ptr *pp;
3226 * pp is still set to the first pointer in the block.
3227 * Make it the new root of the btree.
3229 pp = xfs_btree_ptr_addr(cur, 1, block);
3230 error = xfs_btree_kill_root(cur, bp, level, pp);
3231 if (error)
3232 goto error0;
3233 } else if (level > 0) {
3234 error = xfs_btree_dec_cursor(cur, level, stat);
3235 if (error)
3236 goto error0;
3238 *stat = 1;
3239 return 0;
3243 * If we deleted the leftmost entry in the block, update the
3244 * key values above us in the tree.
3246 if (ptr == 1) {
3247 error = xfs_btree_updkey(cur, keyp, level + 1);
3248 if (error)
3249 goto error0;
3253 * If the number of records remaining in the block is at least
3254 * the minimum, we're done.
3256 if (numrecs >= cur->bc_ops->get_minrecs(cur, level)) {
3257 error = xfs_btree_dec_cursor(cur, level, stat);
3258 if (error)
3259 goto error0;
3260 return 0;
3264 * Otherwise, we have to move some records around to keep the
3265 * tree balanced. Look at the left and right sibling blocks to
3266 * see if we can re-balance by moving only one record.
3268 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
3269 xfs_btree_get_sibling(cur, block, &lptr, XFS_BB_LEFTSIB);
3271 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3273 * One child of root, need to get a chance to copy its contents
3274 * into the root and delete it. Can't go up to next level,
3275 * there's nothing to delete there.
3277 if (xfs_btree_ptr_is_null(cur, &rptr) &&
3278 xfs_btree_ptr_is_null(cur, &lptr) &&
3279 level == cur->bc_nlevels - 2) {
3280 error = xfs_btree_kill_iroot(cur);
3281 if (!error)
3282 error = xfs_btree_dec_cursor(cur, level, stat);
3283 if (error)
3284 goto error0;
3285 return 0;
3289 ASSERT(!xfs_btree_ptr_is_null(cur, &rptr) ||
3290 !xfs_btree_ptr_is_null(cur, &lptr));
3293 * Duplicate the cursor so our btree manipulations here won't
3294 * disrupt the next level up.
3296 error = xfs_btree_dup_cursor(cur, &tcur);
3297 if (error)
3298 goto error0;
3301 * If there's a right sibling, see if it's ok to shift an entry
3302 * out of it.
3304 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
3306 * Move the temp cursor to the last entry in the next block.
3307 * Actually any entry but the first would suffice.
3309 i = xfs_btree_lastrec(tcur, level);
3310 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3312 error = xfs_btree_increment(tcur, level, &i);
3313 if (error)
3314 goto error0;
3315 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3317 i = xfs_btree_lastrec(tcur, level);
3318 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3320 /* Grab a pointer to the block. */
3321 right = xfs_btree_get_block(tcur, level, &rbp);
3322 #ifdef DEBUG
3323 error = xfs_btree_check_block(tcur, right, level, rbp);
3324 if (error)
3325 goto error0;
3326 #endif
3327 /* Grab the current block number, for future use. */
3328 xfs_btree_get_sibling(tcur, right, &cptr, XFS_BB_LEFTSIB);
3331 * If right block is full enough so that removing one entry
3332 * won't make it too empty, and left-shifting an entry out
3333 * of right to us works, we're done.
3335 if (xfs_btree_get_numrecs(right) - 1 >=
3336 cur->bc_ops->get_minrecs(tcur, level)) {
3337 error = xfs_btree_lshift(tcur, level, &i);
3338 if (error)
3339 goto error0;
3340 if (i) {
3341 ASSERT(xfs_btree_get_numrecs(block) >=
3342 cur->bc_ops->get_minrecs(tcur, level));
3344 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3345 tcur = NULL;
3347 error = xfs_btree_dec_cursor(cur, level, stat);
3348 if (error)
3349 goto error0;
3350 return 0;
3355 * Otherwise, grab the number of records in right for
3356 * future reference, and fix up the temp cursor to point
3357 * to our block again (last record).
3359 rrecs = xfs_btree_get_numrecs(right);
3360 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3361 i = xfs_btree_firstrec(tcur, level);
3362 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3364 error = xfs_btree_decrement(tcur, level, &i);
3365 if (error)
3366 goto error0;
3367 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3372 * If there's a left sibling, see if it's ok to shift an entry
3373 * out of it.
3375 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3377 * Move the temp cursor to the first entry in the
3378 * previous block.
3380 i = xfs_btree_firstrec(tcur, level);
3381 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3383 error = xfs_btree_decrement(tcur, level, &i);
3384 if (error)
3385 goto error0;
3386 i = xfs_btree_firstrec(tcur, level);
3387 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3389 /* Grab a pointer to the block. */
3390 left = xfs_btree_get_block(tcur, level, &lbp);
3391 #ifdef DEBUG
3392 error = xfs_btree_check_block(cur, left, level, lbp);
3393 if (error)
3394 goto error0;
3395 #endif
3396 /* Grab the current block number, for future use. */
3397 xfs_btree_get_sibling(tcur, left, &cptr, XFS_BB_RIGHTSIB);
3400 * If left block is full enough so that removing one entry
3401 * won't make it too empty, and right-shifting an entry out
3402 * of left to us works, we're done.
3404 if (xfs_btree_get_numrecs(left) - 1 >=
3405 cur->bc_ops->get_minrecs(tcur, level)) {
3406 error = xfs_btree_rshift(tcur, level, &i);
3407 if (error)
3408 goto error0;
3409 if (i) {
3410 ASSERT(xfs_btree_get_numrecs(block) >=
3411 cur->bc_ops->get_minrecs(tcur, level));
3412 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3413 tcur = NULL;
3414 if (level == 0)
3415 cur->bc_ptrs[0]++;
3416 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3417 *stat = 1;
3418 return 0;
3423 * Otherwise, grab the number of records in right for
3424 * future reference.
3426 lrecs = xfs_btree_get_numrecs(left);
3429 /* Delete the temp cursor, we're done with it. */
3430 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3431 tcur = NULL;
3433 /* If here, we need to do a join to keep the tree balanced. */
3434 ASSERT(!xfs_btree_ptr_is_null(cur, &cptr));
3436 if (!xfs_btree_ptr_is_null(cur, &lptr) &&
3437 lrecs + xfs_btree_get_numrecs(block) <=
3438 cur->bc_ops->get_maxrecs(cur, level)) {
3440 * Set "right" to be the starting block,
3441 * "left" to be the left neighbor.
3443 rptr = cptr;
3444 right = block;
3445 rbp = bp;
3446 error = xfs_btree_read_buf_block(cur, &lptr, level,
3447 0, &left, &lbp);
3448 if (error)
3449 goto error0;
3452 * If that won't work, see if we can join with the right neighbor block.
3454 } else if (!xfs_btree_ptr_is_null(cur, &rptr) &&
3455 rrecs + xfs_btree_get_numrecs(block) <=
3456 cur->bc_ops->get_maxrecs(cur, level)) {
3458 * Set "left" to be the starting block,
3459 * "right" to be the right neighbor.
3461 lptr = cptr;
3462 left = block;
3463 lbp = bp;
3464 error = xfs_btree_read_buf_block(cur, &rptr, level,
3465 0, &right, &rbp);
3466 if (error)
3467 goto error0;
3470 * Otherwise, we can't fix the imbalance.
3471 * Just return. This is probably a logic error, but it's not fatal.
3473 } else {
3474 error = xfs_btree_dec_cursor(cur, level, stat);
3475 if (error)
3476 goto error0;
3477 return 0;
3480 rrecs = xfs_btree_get_numrecs(right);
3481 lrecs = xfs_btree_get_numrecs(left);
3484 * We're now going to join "left" and "right" by moving all the stuff
3485 * in "right" to "left" and deleting "right".
3487 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
3488 if (level > 0) {
3489 /* It's a non-leaf. Move keys and pointers. */
3490 union xfs_btree_key *lkp; /* left btree key */
3491 union xfs_btree_ptr *lpp; /* left address pointer */
3492 union xfs_btree_key *rkp; /* right btree key */
3493 union xfs_btree_ptr *rpp; /* right address pointer */
3495 lkp = xfs_btree_key_addr(cur, lrecs + 1, left);
3496 lpp = xfs_btree_ptr_addr(cur, lrecs + 1, left);
3497 rkp = xfs_btree_key_addr(cur, 1, right);
3498 rpp = xfs_btree_ptr_addr(cur, 1, right);
3499 #ifdef DEBUG
3500 for (i = 1; i < rrecs; i++) {
3501 error = xfs_btree_check_ptr(cur, rpp, i, level);
3502 if (error)
3503 goto error0;
3505 #endif
3506 xfs_btree_copy_keys(cur, lkp, rkp, rrecs);
3507 xfs_btree_copy_ptrs(cur, lpp, rpp, rrecs);
3509 xfs_btree_log_keys(cur, lbp, lrecs + 1, lrecs + rrecs);
3510 xfs_btree_log_ptrs(cur, lbp, lrecs + 1, lrecs + rrecs);
3511 } else {
3512 /* It's a leaf. Move records. */
3513 union xfs_btree_rec *lrp; /* left record pointer */
3514 union xfs_btree_rec *rrp; /* right record pointer */
3516 lrp = xfs_btree_rec_addr(cur, lrecs + 1, left);
3517 rrp = xfs_btree_rec_addr(cur, 1, right);
3519 xfs_btree_copy_recs(cur, lrp, rrp, rrecs);
3520 xfs_btree_log_recs(cur, lbp, lrecs + 1, lrecs + rrecs);
3523 XFS_BTREE_STATS_INC(cur, join);
3526 * Fix up the number of records and right block pointer in the
3527 * surviving block, and log it.
3529 xfs_btree_set_numrecs(left, lrecs + rrecs);
3530 xfs_btree_get_sibling(cur, right, &cptr, XFS_BB_RIGHTSIB),
3531 xfs_btree_set_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
3532 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
3534 /* If there is a right sibling, point it to the remaining block. */
3535 xfs_btree_get_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
3536 if (!xfs_btree_ptr_is_null(cur, &cptr)) {
3537 error = xfs_btree_read_buf_block(cur, &cptr, level,
3538 0, &rrblock, &rrbp);
3539 if (error)
3540 goto error0;
3541 xfs_btree_set_sibling(cur, rrblock, &lptr, XFS_BB_LEFTSIB);
3542 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
3545 /* Free the deleted block. */
3546 error = cur->bc_ops->free_block(cur, rbp);
3547 if (error)
3548 goto error0;
3549 XFS_BTREE_STATS_INC(cur, free);
3552 * If we joined with the left neighbor, set the buffer in the
3553 * cursor to the left block, and fix up the index.
3555 if (bp != lbp) {
3556 cur->bc_bufs[level] = lbp;
3557 cur->bc_ptrs[level] += lrecs;
3558 cur->bc_ra[level] = 0;
3561 * If we joined with the right neighbor and there's a level above
3562 * us, increment the cursor at that level.
3564 else if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) ||
3565 (level + 1 < cur->bc_nlevels)) {
3566 error = xfs_btree_increment(cur, level + 1, &i);
3567 if (error)
3568 goto error0;
3572 * Readjust the ptr at this level if it's not a leaf, since it's
3573 * still pointing at the deletion point, which makes the cursor
3574 * inconsistent. If this makes the ptr 0, the caller fixes it up.
3575 * We can't use decrement because it would change the next level up.
3577 if (level > 0)
3578 cur->bc_ptrs[level]--;
3580 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3581 /* Return value means the next level up has something to do. */
3582 *stat = 2;
3583 return 0;
3585 error0:
3586 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3587 if (tcur)
3588 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
3589 return error;
3593 * Delete the record pointed to by cur.
3594 * The cursor refers to the place where the record was (could be inserted)
3595 * when the operation returns.
3597 int /* error */
3598 xfs_btree_delete(
3599 struct xfs_btree_cur *cur,
3600 int *stat) /* success/failure */
3602 int error; /* error return value */
3603 int level;
3604 int i;
3606 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3609 * Go up the tree, starting at leaf level.
3611 * If 2 is returned then a join was done; go to the next level.
3612 * Otherwise we are done.
3614 for (level = 0, i = 2; i == 2; level++) {
3615 error = xfs_btree_delrec(cur, level, &i);
3616 if (error)
3617 goto error0;
3620 if (i == 0) {
3621 for (level = 1; level < cur->bc_nlevels; level++) {
3622 if (cur->bc_ptrs[level] == 0) {
3623 error = xfs_btree_decrement(cur, level, &i);
3624 if (error)
3625 goto error0;
3626 break;
3631 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3632 *stat = i;
3633 return 0;
3634 error0:
3635 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3636 return error;
3640 * Get the data from the pointed-to record.
3642 int /* error */
3643 xfs_btree_get_rec(
3644 struct xfs_btree_cur *cur, /* btree cursor */
3645 union xfs_btree_rec **recp, /* output: btree record */
3646 int *stat) /* output: success/failure */
3648 struct xfs_btree_block *block; /* btree block */
3649 struct xfs_buf *bp; /* buffer pointer */
3650 int ptr; /* record number */
3651 #ifdef DEBUG
3652 int error; /* error return value */
3653 #endif
3655 ptr = cur->bc_ptrs[0];
3656 block = xfs_btree_get_block(cur, 0, &bp);
3658 #ifdef DEBUG
3659 error = xfs_btree_check_block(cur, block, 0, bp);
3660 if (error)
3661 return error;
3662 #endif
3665 * Off the right end or left end, return failure.
3667 if (ptr > xfs_btree_get_numrecs(block) || ptr <= 0) {
3668 *stat = 0;
3669 return 0;
3673 * Point to the record and extract its data.
3675 *recp = xfs_btree_rec_addr(cur, ptr, block);
3676 *stat = 1;
3677 return 0;