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xfs: check magic numbers in dir3 leaf verifier first
[deliverable/linux.git] / fs / xfs / xfs_btree.c
CommitLineData
1da177e4 1/*
7b718769
NS		 2 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
1da177e4 4 *
7b718769
NS		 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
1da177e4
LT		 7 * published by the Free Software Foundation.
8 *
7b718769
NS		 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.
1da177e4 13 *
7b718769
NS		 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
1da177e4 17 */
1da177e4 18#include "xfs.h"
a844f451 19#include "xfs_fs.h"
1da177e4 20#include "xfs_types.h"
a844f451 21#include "xfs_bit.h"
1da177e4
LT		 22#include "xfs_log.h"
23#include "xfs_trans.h"
24#include "xfs_sb.h"
25#include "xfs_ag.h"
1da177e4 26#include "xfs_mount.h"
1da177e4 27#include "xfs_bmap_btree.h"
a844f451 28#include "xfs_alloc_btree.h"
1da177e4 29#include "xfs_ialloc_btree.h"
1da177e4
LT		 30#include "xfs_dinode.h"
31#include "xfs_inode.h"
38bb7423 32#include "xfs_inode_item.h"
ee1a47ab 33#include "xfs_buf_item.h"
a844f451 34#include "xfs_btree.h"
1da177e4 35#include "xfs_error.h"
0b1b213f 36#include "xfs_trace.h"
ee1a47ab 37#include "xfs_cksum.h"
1da177e4
LT		 38
39/*
40 * Cursor allocation zone.
41 */
42kmem_zone_t *xfs_btree_cur_zone;
43
44/*
45 * Btree magic numbers.
46 */
ee1a47ab
CH		 47static const __uint32_t xfs_magics[2][XFS_BTNUM_MAX] = {
48 { XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, XFS_BMAP_MAGIC, XFS_IBT_MAGIC },
49 { XFS_ABTB_CRC_MAGIC, XFS_ABTC_CRC_MAGIC,
50 XFS_BMAP_CRC_MAGIC, XFS_IBT_CRC_MAGIC }
1da177e4 51};
ee1a47ab
CH		 52#define xfs_btree_magic(cur) \
53 xfs_magics[!!((cur)->bc_flags & XFS_BTREE_CRC_BLOCKS)][cur->bc_btnum]
1da177e4 54
1da177e4 55
7cc95a82 56STATIC int /* error (0 or EFSCORRUPTED) */
a23f6ef8
CH		 57xfs_btree_check_lblock(
58 struct xfs_btree_cur *cur, /* btree cursor */
7cc95a82 59 struct xfs_btree_block *block, /* btree long form block pointer */
a23f6ef8
CH		 60 int level, /* level of the btree block */
61 struct xfs_buf *bp) /* buffer for block, if any */
62{
ee1a47ab 63 int lblock_ok = 1; /* block passes checks */
a23f6ef8
CH		 64 struct xfs_mount *mp; /* file system mount point */
65
66 mp = cur->bc_mp;
ee1a47ab
CH		 67
68 if (xfs_sb_version_hascrc(&mp->m_sb)) {
69 lblock_ok = lblock_ok &&
70 uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_uuid) &&
71 block->bb_u.l.bb_blkno == cpu_to_be64(
72 bp ? bp->b_bn : XFS_BUF_DADDR_NULL);
73 }
74
75 lblock_ok = lblock_ok &&
76 be32_to_cpu(block->bb_magic) == xfs_btree_magic(cur) &&
a23f6ef8
CH		 77 be16_to_cpu(block->bb_level) == level &&
78 be16_to_cpu(block->bb_numrecs) <=
ce5e42db 79 cur->bc_ops->get_maxrecs(cur, level) &&
7cc95a82 80 block->bb_u.l.bb_leftsib &&
69ef921b 81 (block->bb_u.l.bb_leftsib == cpu_to_be64(NULLDFSBNO) ||
7cc95a82 82 XFS_FSB_SANITY_CHECK(mp,
ee1a47ab 83 be64_to_cpu(block->bb_u.l.bb_leftsib))) &&
7cc95a82 84 block->bb_u.l.bb_rightsib &&
69ef921b 85 (block->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO) ||
7cc95a82 86 XFS_FSB_SANITY_CHECK(mp,
ee1a47ab
CH		 87 be64_to_cpu(block->bb_u.l.bb_rightsib)));
88
a23f6ef8
CH		 89 if (unlikely(XFS_TEST_ERROR(!lblock_ok, mp,
90 XFS_ERRTAG_BTREE_CHECK_LBLOCK,
91 XFS_RANDOM_BTREE_CHECK_LBLOCK))) {
92 if (bp)
0b1b213f 93 trace_xfs_btree_corrupt(bp, _RET_IP_);
ee1a47ab 94 XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
a23f6ef8
CH		 95 return XFS_ERROR(EFSCORRUPTED);
96 }
97 return 0;
98}
99
3cc7524c 100STATIC int /* error (0 or EFSCORRUPTED) */
1da177e4 101xfs_btree_check_sblock(
a23f6ef8 102 struct xfs_btree_cur *cur, /* btree cursor */
7cc95a82 103 struct xfs_btree_block *block, /* btree short form block pointer */
1da177e4 104 int level, /* level of the btree block */
a23f6ef8 105 struct xfs_buf *bp) /* buffer containing block */
1da177e4 106{
ee1a47ab 107 struct xfs_mount *mp; /* file system mount point */
a23f6ef8
CH		 108 struct xfs_buf *agbp; /* buffer for ag. freespace struct */
109 struct xfs_agf *agf; /* ag. freespace structure */
1da177e4 110 xfs_agblock_t agflen; /* native ag. freespace length */
ee1a47ab 111 int sblock_ok = 1; /* block passes checks */
1da177e4 112
ee1a47ab 113 mp = cur->bc_mp;
1da177e4
LT		 114 agbp = cur->bc_private.a.agbp;
115 agf = XFS_BUF_TO_AGF(agbp);
16259e7d 116 agflen = be32_to_cpu(agf->agf_length);
ee1a47ab
CH		 117
118 if (xfs_sb_version_hascrc(&mp->m_sb)) {
119 sblock_ok = sblock_ok &&
120 uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_uuid) &&
121 block->bb_u.s.bb_blkno == cpu_to_be64(
122 bp ? bp->b_bn : XFS_BUF_DADDR_NULL);
123 }
124
125 sblock_ok = sblock_ok &&
126 be32_to_cpu(block->bb_magic) == xfs_btree_magic(cur) &&
16259e7d
CH		 127 be16_to_cpu(block->bb_level) == level &&
128 be16_to_cpu(block->bb_numrecs) <=
ce5e42db 129 cur->bc_ops->get_maxrecs(cur, level) &&
69ef921b 130 (block->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK) ||
7cc95a82
CH		 131 be32_to_cpu(block->bb_u.s.bb_leftsib) < agflen) &&
132 block->bb_u.s.bb_leftsib &&
69ef921b 133 (block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK) ||
7cc95a82
CH		 134 be32_to_cpu(block->bb_u.s.bb_rightsib) < agflen) &&
135 block->bb_u.s.bb_rightsib;
ee1a47ab
CH		 136
137 if (unlikely(XFS_TEST_ERROR(!sblock_ok, mp,
1da177e4
LT		 138 XFS_ERRTAG_BTREE_CHECK_SBLOCK,
139 XFS_RANDOM_BTREE_CHECK_SBLOCK))) {
140 if (bp)
0b1b213f 141 trace_xfs_btree_corrupt(bp, _RET_IP_);
ee1a47ab 142 XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
1da177e4
LT		 143 return XFS_ERROR(EFSCORRUPTED);
144 }
145 return 0;
146}
147
148/*
a23f6ef8
CH		 149 * Debug routine: check that block header is ok.
150 */
151int
152xfs_btree_check_block(
153 struct xfs_btree_cur *cur, /* btree cursor */
154 struct xfs_btree_block *block, /* generic btree block pointer */
155 int level, /* level of the btree block */
156 struct xfs_buf *bp) /* buffer containing block, if any */
157{
7cc95a82
CH		 158 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
159 return xfs_btree_check_lblock(cur, block, level, bp);
160 else
161 return xfs_btree_check_sblock(cur, block, level, bp);
a23f6ef8
CH		 162}
163
164/*
165 * Check that (long) pointer is ok.
166 */
167int /* error (0 or EFSCORRUPTED) */
168xfs_btree_check_lptr(
169 struct xfs_btree_cur *cur, /* btree cursor */
170 xfs_dfsbno_t bno, /* btree block disk address */
171 int level) /* btree block level */
172{
173 XFS_WANT_CORRUPTED_RETURN(
174 level > 0 &&
175 bno != NULLDFSBNO &&
176 XFS_FSB_SANITY_CHECK(cur->bc_mp, bno));
177 return 0;
178}
179
24ee0e49 180#ifdef DEBUG
a23f6ef8
CH		 181/*
182 * Check that (short) pointer is ok.
1da177e4 183 */
3cc7524c 184STATIC int /* error (0 or EFSCORRUPTED) */
1da177e4 185xfs_btree_check_sptr(
a23f6ef8
CH		 186 struct xfs_btree_cur *cur, /* btree cursor */
187 xfs_agblock_t bno, /* btree block disk address */
188 int level) /* btree block level */
1da177e4 189{
a23f6ef8 190 xfs_agblock_t agblocks = cur->bc_mp->m_sb.sb_agblocks;
1da177e4 191
1da177e4
LT		 192 XFS_WANT_CORRUPTED_RETURN(
193 level > 0 &&
a23f6ef8
CH		 194 bno != NULLAGBLOCK &&
195 bno != 0 &&
196 bno < agblocks);
1da177e4
LT		 197 return 0;
198}
199
a23f6ef8
CH		 200/*
201 * Check that block ptr is ok.
202 */
3cc7524c 203STATIC int /* error (0 or EFSCORRUPTED) */
a23f6ef8
CH		 204xfs_btree_check_ptr(
205 struct xfs_btree_cur *cur, /* btree cursor */
206 union xfs_btree_ptr *ptr, /* btree block disk address */
207 int index, /* offset from ptr to check */
208 int level) /* btree block level */
209{
210 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
211 return xfs_btree_check_lptr(cur,
212 be64_to_cpu((&ptr->l)[index]), level);
213 } else {
214 return xfs_btree_check_sptr(cur,
215 be32_to_cpu((&ptr->s)[index]), level);
216 }
217}
24ee0e49 218#endif
a23f6ef8 219
ee1a47ab
CH		 220/*
221 * Calculate CRC on the whole btree block and stuff it into the
222 * long-form btree header.
223 *
224 * Prior to calculting the CRC, pull the LSN out of the buffer log item and put
225 * it into the buffer so recovery knows what the last modifcation was that made
226 * it to disk.
227 */
228void
229xfs_btree_lblock_calc_crc(
230 struct xfs_buf *bp)
231{
232 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
233 struct xfs_buf_log_item *bip = bp->b_fspriv;
234
235 if (!xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb))
236 return;
237 if (bip)
238 block->bb_u.l.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
239 xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
240 XFS_BTREE_LBLOCK_CRC_OFF);
241}
242
243bool
244xfs_btree_lblock_verify_crc(
245 struct xfs_buf *bp)
246{
247 if (xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb))
248 return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
249 XFS_BTREE_LBLOCK_CRC_OFF);
250 return true;
251}
252
253/*
254 * Calculate CRC on the whole btree block and stuff it into the
255 * short-form btree header.
256 *
257 * Prior to calculting the CRC, pull the LSN out of the buffer log item and put
258 * it into the buffer so recovery knows what the last modifcation was that made
259 * it to disk.
260 */
261void
262xfs_btree_sblock_calc_crc(
263 struct xfs_buf *bp)
264{
265 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
266 struct xfs_buf_log_item *bip = bp->b_fspriv;
267
268 if (!xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb))
269 return;
270 if (bip)
271 block->bb_u.s.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
272 xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
273 XFS_BTREE_SBLOCK_CRC_OFF);
274}
275
276bool
277xfs_btree_sblock_verify_crc(
278 struct xfs_buf *bp)
279{
280 if (xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb))
281 return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
282 XFS_BTREE_SBLOCK_CRC_OFF);
283 return true;
284}
285
1da177e4
LT		 286/*
287 * Delete the btree cursor.
288 */
289void
290xfs_btree_del_cursor(
291 xfs_btree_cur_t *cur, /* btree cursor */
292 int error) /* del because of error */
293{
294 int i; /* btree level */
295
296 /*
297 * Clear the buffer pointers, and release the buffers.
298 * If we're doing this in the face of an error, we
299 * need to make sure to inspect all of the entries
300 * in the bc_bufs array for buffers to be unlocked.
301 * This is because some of the btree code works from
302 * level n down to 0, and if we get an error along
303 * the way we won't have initialized all the entries
304 * down to 0.
305 */
306 for (i = 0; i < cur->bc_nlevels; i++) {
307 if (cur->bc_bufs[i])
c0e59e1a 308 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[i]);
1da177e4
LT		 309 else if (!error)
310 break;
311 }
312 /*
313 * Can't free a bmap cursor without having dealt with the
314 * allocated indirect blocks' accounting.
315 */
316 ASSERT(cur->bc_btnum != XFS_BTNUM_BMAP ||
317 cur->bc_private.b.allocated == 0);
318 /*
319 * Free the cursor.
320 */
321 kmem_zone_free(xfs_btree_cur_zone, cur);
322}
323
324/*
325 * Duplicate the btree cursor.
326 * Allocate a new one, copy the record, re-get the buffers.
327 */
328int /* error */
329xfs_btree_dup_cursor(
330 xfs_btree_cur_t *cur, /* input cursor */
331 xfs_btree_cur_t **ncur) /* output cursor */
332{
333 xfs_buf_t *bp; /* btree block's buffer pointer */
334 int error; /* error return value */
335 int i; /* level number of btree block */
336 xfs_mount_t *mp; /* mount structure for filesystem */
337 xfs_btree_cur_t *new; /* new cursor value */
338 xfs_trans_t *tp; /* transaction pointer, can be NULL */
339
340 tp = cur->bc_tp;
341 mp = cur->bc_mp;
561f7d17 342
1da177e4
LT		 343 /*
344 * Allocate a new cursor like the old one.
345 */
561f7d17
CH		 346 new = cur->bc_ops->dup_cursor(cur);
347
1da177e4
LT		 348 /*
349 * Copy the record currently in the cursor.
350 */
351 new->bc_rec = cur->bc_rec;
561f7d17 352
1da177e4
LT		 353 /*
354 * For each level current, re-get the buffer and copy the ptr value.
355 */
356 for (i = 0; i < new->bc_nlevels; i++) {
357 new->bc_ptrs[i] = cur->bc_ptrs[i];
358 new->bc_ra[i] = cur->bc_ra[i];
c3f8fc73
DC		 359 bp = cur->bc_bufs[i];
360 if (bp) {
361 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
362 XFS_BUF_ADDR(bp), mp->m_bsize,
3d3e6f64 363 0, &bp,
1813dd64 364 cur->bc_ops->buf_ops);
c3f8fc73 365 if (error) {
1da177e4
LT		 366 xfs_btree_del_cursor(new, error);
367 *ncur = NULL;
368 return error;
369 }
ee1a47ab
CH		 370 }
371 new->bc_bufs[i] = bp;
1da177e4 372 }
1da177e4
LT		 373 *ncur = new;
374 return 0;
375}
376
65f1eaea
CH		 377/*
378 * XFS btree block layout and addressing:
379 *
380 * There are two types of blocks in the btree: leaf and non-leaf blocks.
381 *
382 * The leaf record start with a header then followed by records containing
383 * the values. A non-leaf block also starts with the same header, and
384 * then first contains lookup keys followed by an equal number of pointers
385 * to the btree blocks at the previous level.
386 *
387 * +--------+-------+-------+-------+-------+-------+-------+
388 * Leaf: | header | rec 1 | rec 2 | rec 3 | rec 4 | rec 5 | rec N |
389 * +--------+-------+-------+-------+-------+-------+-------+
390 *
391 * +--------+-------+-------+-------+-------+-------+-------+
392 * Non-Leaf: | header | key 1 | key 2 | key N | ptr 1 | ptr 2 | ptr N |
393 * +--------+-------+-------+-------+-------+-------+-------+
394 *
395 * The header is called struct xfs_btree_block for reasons better left unknown
396 * and comes in different versions for short (32bit) and long (64bit) block
397 * pointers. The record and key structures are defined by the btree instances
398 * and opaque to the btree core. The block pointers are simple disk endian
399 * integers, available in a short (32bit) and long (64bit) variant.
400 *
401 * The helpers below calculate the offset of a given record, key or pointer
402 * into a btree block (xfs_btree_*_offset) or return a pointer to the given
403 * record, key or pointer (xfs_btree_*_addr). Note that all addressing
404 * inside the btree block is done using indices starting at one, not zero!
405 */
406
407/*
408 * Return size of the btree block header for this btree instance.
409 */
410static inline size_t xfs_btree_block_len(struct xfs_btree_cur *cur)
411{
ee1a47ab
CH		 412 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
413 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
414 return XFS_BTREE_LBLOCK_CRC_LEN;
415 return XFS_BTREE_LBLOCK_LEN;
416 }
417 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
418 return XFS_BTREE_SBLOCK_CRC_LEN;
419 return XFS_BTREE_SBLOCK_LEN;
65f1eaea
CH		 420}
421
422/*
423 * Return size of btree block pointers for this btree instance.
424 */
425static inline size_t xfs_btree_ptr_len(struct xfs_btree_cur *cur)
426{
427 return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
428 sizeof(__be64) : sizeof(__be32);
429}
430
431/*
432 * Calculate offset of the n-th record in a btree block.
433 */
434STATIC size_t
435xfs_btree_rec_offset(
436 struct xfs_btree_cur *cur,
437 int n)
438{
439 return xfs_btree_block_len(cur) +
440 (n - 1) * cur->bc_ops->rec_len;
441}
442
443/*
444 * Calculate offset of the n-th key in a btree block.
445 */
446STATIC size_t
447xfs_btree_key_offset(
448 struct xfs_btree_cur *cur,
449 int n)
450{
451 return xfs_btree_block_len(cur) +
452 (n - 1) * cur->bc_ops->key_len;
453}
454
455/*
456 * Calculate offset of the n-th block pointer in a btree block.
457 */
458STATIC size_t
459xfs_btree_ptr_offset(
460 struct xfs_btree_cur *cur,
461 int n,
462 int level)
463{
464 return xfs_btree_block_len(cur) +
465 cur->bc_ops->get_maxrecs(cur, level) * cur->bc_ops->key_len +
466 (n - 1) * xfs_btree_ptr_len(cur);
467}
468
469/*
470 * Return a pointer to the n-th record in the btree block.
471 */
472STATIC union xfs_btree_rec *
473xfs_btree_rec_addr(
474 struct xfs_btree_cur *cur,
475 int n,
476 struct xfs_btree_block *block)
477{
478 return (union xfs_btree_rec *)
479 ((char *)block + xfs_btree_rec_offset(cur, n));
480}
481
482/*
483 * Return a pointer to the n-th key in the btree block.
484 */
485STATIC union xfs_btree_key *
486xfs_btree_key_addr(
487 struct xfs_btree_cur *cur,
488 int n,
489 struct xfs_btree_block *block)
490{
491 return (union xfs_btree_key *)
492 ((char *)block + xfs_btree_key_offset(cur, n));
493}
494
495/*
496 * Return a pointer to the n-th block pointer in the btree block.
497 */
498STATIC union xfs_btree_ptr *
499xfs_btree_ptr_addr(
500 struct xfs_btree_cur *cur,
501 int n,
502 struct xfs_btree_block *block)
503{
504 int level = xfs_btree_get_level(block);
505
506 ASSERT(block->bb_level != 0);
507
508 return (union xfs_btree_ptr *)
509 ((char *)block + xfs_btree_ptr_offset(cur, n, level));
510}
511
8186e517 512/*
1cb93863 513 * Get the root block which is stored in the inode.
8186e517
CH		 514 *
515 * For now this btree implementation assumes the btree root is always
516 * stored in the if_broot field of an inode fork.
517 */
518STATIC struct xfs_btree_block *
519xfs_btree_get_iroot(
520 struct xfs_btree_cur *cur)
521{
522 struct xfs_ifork *ifp;
523
524 ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, cur->bc_private.b.whichfork);
525 return (struct xfs_btree_block *)ifp->if_broot;
526}
527
1da177e4
LT		 528/*
529 * Retrieve the block pointer from the cursor at the given level.
8186e517 530 * This may be an inode btree root or from a buffer.
1da177e4 531 */
8186e517 532STATIC struct xfs_btree_block * /* generic btree block pointer */
1da177e4 533xfs_btree_get_block(
8186e517 534 struct xfs_btree_cur *cur, /* btree cursor */
1da177e4 535 int level, /* level in btree */
8186e517 536 struct xfs_buf **bpp) /* buffer containing the block */
1da177e4 537{
8186e517
CH		 538 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
539 (level == cur->bc_nlevels - 1)) {
540 *bpp = NULL;
541 return xfs_btree_get_iroot(cur);
1da177e4 542 }
8186e517
CH		 543
544 *bpp = cur->bc_bufs[level];
545 return XFS_BUF_TO_BLOCK(*bpp);
1da177e4
LT		 546}
547
548/*
549 * Get a buffer for the block, return it with no data read.
550 * Long-form addressing.
551 */
552xfs_buf_t * /* buffer for fsbno */
553xfs_btree_get_bufl(
554 xfs_mount_t *mp, /* file system mount point */
555 xfs_trans_t *tp, /* transaction pointer */
556 xfs_fsblock_t fsbno, /* file system block number */
557 uint lock) /* lock flags for get_buf */
558{
559 xfs_buf_t *bp; /* buffer pointer (return value) */
560 xfs_daddr_t d; /* real disk block address */
561
562 ASSERT(fsbno != NULLFSBLOCK);
563 d = XFS_FSB_TO_DADDR(mp, fsbno);
564 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
5a52c2a5 565 ASSERT(!xfs_buf_geterror(bp));
1da177e4
LT		 566 return bp;
567}
568
569/*
570 * Get a buffer for the block, return it with no data read.
571 * Short-form addressing.
572 */
573xfs_buf_t * /* buffer for agno/agbno */
574xfs_btree_get_bufs(
575 xfs_mount_t *mp, /* file system mount point */
576 xfs_trans_t *tp, /* transaction pointer */
577 xfs_agnumber_t agno, /* allocation group number */
578 xfs_agblock_t agbno, /* allocation group block number */
579 uint lock) /* lock flags for get_buf */
580{
581 xfs_buf_t *bp; /* buffer pointer (return value) */
582 xfs_daddr_t d; /* real disk block address */
583
584 ASSERT(agno != NULLAGNUMBER);
585 ASSERT(agbno != NULLAGBLOCK);
586 d = XFS_AGB_TO_DADDR(mp, agno, agbno);
587 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
5a52c2a5 588 ASSERT(!xfs_buf_geterror(bp));
1da177e4
LT		 589 return bp;
590}
591
1da177e4
LT		 592/*
593 * Check for the cursor referring to the last block at the given level.
594 */
595int /* 1=is last block, 0=not last block */
596xfs_btree_islastblock(
597 xfs_btree_cur_t *cur, /* btree cursor */
598 int level) /* level to check */
599{
7cc95a82 600 struct xfs_btree_block *block; /* generic btree block pointer */
1da177e4
LT		 601 xfs_buf_t *bp; /* buffer containing block */
602
603 block = xfs_btree_get_block(cur, level, &bp);
604 xfs_btree_check_block(cur, block, level, bp);
e99ab90d 605 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
69ef921b 606 return block->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO);
1da177e4 607 else
69ef921b 608 return block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK);
1da177e4
LT		 609}
610
cdcf4333
CH		 611/*
612 * Change the cursor to point to the first record at the given level.
613 * Other levels are unaffected.
614 */
3cc7524c 615STATIC int /* success=1, failure=0 */
cdcf4333
CH		 616xfs_btree_firstrec(
617 xfs_btree_cur_t *cur, /* btree cursor */
618 int level) /* level to change */
619{
7cc95a82 620 struct xfs_btree_block *block; /* generic btree block pointer */
cdcf4333
CH		 621 xfs_buf_t *bp; /* buffer containing block */
622
623 /*
624 * Get the block pointer for this level.
625 */
626 block = xfs_btree_get_block(cur, level, &bp);
627 xfs_btree_check_block(cur, block, level, bp);
628 /*
629 * It's empty, there is no such record.
630 */
f2277f06 631 if (!block->bb_numrecs)
cdcf4333
CH		 632 return 0;
633 /*
634 * Set the ptr value to 1, that's the first record/key.
635 */
636 cur->bc_ptrs[level] = 1;
637 return 1;
638}
639
1da177e4
LT		 640/*
641 * Change the cursor to point to the last record in the current block
642 * at the given level. Other levels are unaffected.
643 */
3cc7524c 644STATIC int /* success=1, failure=0 */
1da177e4
LT		 645xfs_btree_lastrec(
646 xfs_btree_cur_t *cur, /* btree cursor */
647 int level) /* level to change */
648{
7cc95a82 649 struct xfs_btree_block *block; /* generic btree block pointer */
1da177e4
LT		 650 xfs_buf_t *bp; /* buffer containing block */
651
652 /*
653 * Get the block pointer for this level.
654 */
655 block = xfs_btree_get_block(cur, level, &bp);
656 xfs_btree_check_block(cur, block, level, bp);
657 /*
658 * It's empty, there is no such record.
659 */
f2277f06 660 if (!block->bb_numrecs)
1da177e4
LT		 661 return 0;
662 /*
663 * Set the ptr value to numrecs, that's the last record/key.
664 */
f2277f06 665 cur->bc_ptrs[level] = be16_to_cpu(block->bb_numrecs);
1da177e4
LT		 666 return 1;
667}
668
669/*
670 * Compute first and last byte offsets for the fields given.
671 * Interprets the offsets table, which contains struct field offsets.
672 */
673void
674xfs_btree_offsets(
675 __int64_t fields, /* bitmask of fields */
676 const short *offsets, /* table of field offsets */
677 int nbits, /* number of bits to inspect */
678 int *first, /* output: first byte offset */
679 int *last) /* output: last byte offset */
680{
681 int i; /* current bit number */
682 __int64_t imask; /* mask for current bit number */
683
684 ASSERT(fields != 0);
685 /*
686 * Find the lowest bit, so the first byte offset.
687 */
688 for (i = 0, imask = 1LL; ; i++, imask <<= 1) {
689 if (imask & fields) {
690 *first = offsets[i];
691 break;
692 }
693 }
694 /*
695 * Find the highest bit, so the last byte offset.
696 */
697 for (i = nbits - 1, imask = 1LL << i; ; i--, imask >>= 1) {
698 if (imask & fields) {
699 *last = offsets[i + 1] - 1;
700 break;
701 }
702 }
703}
704
705/*
706 * Get a buffer for the block, return it read in.
707 * Long-form addressing.
708 */
3d3e6f64 709int
1da177e4 710xfs_btree_read_bufl(
3d3e6f64
DC		 711 struct xfs_mount *mp, /* file system mount point */
712 struct xfs_trans *tp, /* transaction pointer */
713 xfs_fsblock_t fsbno, /* file system block number */
714 uint lock, /* lock flags for read_buf */
715 struct xfs_buf **bpp, /* buffer for fsbno */
716 int refval, /* ref count value for buffer */
1813dd64 717 const struct xfs_buf_ops *ops)
1da177e4 718{
3d3e6f64 719 struct xfs_buf *bp; /* return value */
1da177e4 720 xfs_daddr_t d; /* real disk block address */
3d3e6f64 721 int error;
1da177e4
LT		 722
723 ASSERT(fsbno != NULLFSBLOCK);
724 d = XFS_FSB_TO_DADDR(mp, fsbno);
c3f8fc73 725 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
1813dd64 726 mp->m_bsize, lock, &bp, ops);
c3f8fc73 727 if (error)
1da177e4 728 return error;
5a52c2a5 729 ASSERT(!xfs_buf_geterror(bp));
821eb21d 730 if (bp)
38f23232 731 xfs_buf_set_ref(bp, refval);
1da177e4
LT		 732 *bpp = bp;
733 return 0;
734}
735
1da177e4
LT		 736/*
737 * Read-ahead the block, don't wait for it, don't return a buffer.
738 * Long-form addressing.
739 */
740/* ARGSUSED */
741void
742xfs_btree_reada_bufl(
3d3e6f64
DC		 743 struct xfs_mount *mp, /* file system mount point */
744 xfs_fsblock_t fsbno, /* file system block number */
745 xfs_extlen_t count, /* count of filesystem blocks */
1813dd64 746 const struct xfs_buf_ops *ops)
1da177e4
LT		 747{
748 xfs_daddr_t d;
749
750 ASSERT(fsbno != NULLFSBLOCK);
751 d = XFS_FSB_TO_DADDR(mp, fsbno);
1813dd64 752 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, ops);
1da177e4
LT		 753}
754
755/*
756 * Read-ahead the block, don't wait for it, don't return a buffer.
757 * Short-form addressing.
758 */
759/* ARGSUSED */
760void
761xfs_btree_reada_bufs(
3d3e6f64
DC		 762 struct xfs_mount *mp, /* file system mount point */
763 xfs_agnumber_t agno, /* allocation group number */
764 xfs_agblock_t agbno, /* allocation group block number */
765 xfs_extlen_t count, /* count of filesystem blocks */
1813dd64 766 const struct xfs_buf_ops *ops)
1da177e4
LT		 767{
768 xfs_daddr_t d;
769
770 ASSERT(agno != NULLAGNUMBER);
771 ASSERT(agbno != NULLAGBLOCK);
772 d = XFS_AGB_TO_DADDR(mp, agno, agbno);
1813dd64 773 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, ops);
1da177e4
LT		 774}
775
b524bfee
CH		 776STATIC int
777xfs_btree_readahead_lblock(
778 struct xfs_btree_cur *cur,
779 int lr,
780 struct xfs_btree_block *block)
781{
782 int rval = 0;
e6edbd1c
CH		 783 xfs_dfsbno_t left = be64_to_cpu(block->bb_u.l.bb_leftsib);
784 xfs_dfsbno_t right = be64_to_cpu(block->bb_u.l.bb_rightsib);
b524bfee
CH		 785
786 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLDFSBNO) {
3d3e6f64 787 xfs_btree_reada_bufl(cur->bc_mp, left, 1,
1813dd64 788 cur->bc_ops->buf_ops);
b524bfee
CH		 789 rval++;
790 }
791
792 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLDFSBNO) {
3d3e6f64 793 xfs_btree_reada_bufl(cur->bc_mp, right, 1,
1813dd64 794 cur->bc_ops->buf_ops);
b524bfee
CH		 795 rval++;
796 }
797
798 return rval;
799}
800
801STATIC int
802xfs_btree_readahead_sblock(
803 struct xfs_btree_cur *cur,
804 int lr,
805 struct xfs_btree_block *block)
806{
807 int rval = 0;
808 xfs_agblock_t left = be32_to_cpu(block->bb_u.s.bb_leftsib);
809 xfs_agblock_t right = be32_to_cpu(block->bb_u.s.bb_rightsib);
810
811
812 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLAGBLOCK) {
813 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
1813dd64 814 left, 1, cur->bc_ops->buf_ops);
b524bfee
CH		 815 rval++;
816 }
817
818 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLAGBLOCK) {
819 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
1813dd64 820 right, 1, cur->bc_ops->buf_ops);
b524bfee
CH		 821 rval++;
822 }
823
824 return rval;
825}
826
1da177e4
LT		 827/*
828 * Read-ahead btree blocks, at the given level.
829 * Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA.
830 */
3cc7524c 831STATIC int
b524bfee
CH		 832xfs_btree_readahead(
833 struct xfs_btree_cur *cur, /* btree cursor */
1da177e4
LT		 834 int lev, /* level in btree */
835 int lr) /* left/right bits */
836{
b524bfee
CH		 837 struct xfs_btree_block *block;
838
839 /*
840 * No readahead needed if we are at the root level and the
841 * btree root is stored in the inode.
842 */
843 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
844 (lev == cur->bc_nlevels - 1))
845 return 0;
846
847 if ((cur->bc_ra[lev] | lr) == cur->bc_ra[lev])
848 return 0;
1da177e4 849
1da177e4 850 cur->bc_ra[lev] |= lr;
b524bfee
CH		 851 block = XFS_BUF_TO_BLOCK(cur->bc_bufs[lev]);
852
853 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
854 return xfs_btree_readahead_lblock(cur, lr, block);
855 return xfs_btree_readahead_sblock(cur, lr, block);
1da177e4
LT		 856}
857
858/*
859 * Set the buffer for level "lev" in the cursor to bp, releasing
860 * any previous buffer.
861 */
c0e59e1a 862STATIC void
1da177e4
LT		 863xfs_btree_setbuf(
864 xfs_btree_cur_t *cur, /* btree cursor */
865 int lev, /* level in btree */
866 xfs_buf_t *bp) /* new buffer to set */
867{
7cc95a82 868 struct xfs_btree_block *b; /* btree block */
1da177e4 869
c0e59e1a
CH		 870 if (cur->bc_bufs[lev])
871 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[lev]);
1da177e4
LT		 872 cur->bc_bufs[lev] = bp;
873 cur->bc_ra[lev] = 0;
c0e59e1a 874
1da177e4 875 b = XFS_BUF_TO_BLOCK(bp);
e99ab90d 876 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
69ef921b 877 if (b->bb_u.l.bb_leftsib == cpu_to_be64(NULLDFSBNO))
1da177e4 878 cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
69ef921b 879 if (b->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO))
1da177e4
LT		 880 cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
881 } else {
69ef921b 882 if (b->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK))
1da177e4 883 cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
69ef921b 884 if (b->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK))
1da177e4
LT		 885 cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
886 }
887}
637aa50f
CH		 888
889STATIC int
890xfs_btree_ptr_is_null(
891 struct xfs_btree_cur *cur,
892 union xfs_btree_ptr *ptr)
893{
894 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
69ef921b 895 return ptr->l == cpu_to_be64(NULLDFSBNO);
637aa50f 896 else
69ef921b 897 return ptr->s == cpu_to_be32(NULLAGBLOCK);
637aa50f
CH		 898}
899
4b22a571
CH		 900STATIC void
901xfs_btree_set_ptr_null(
902 struct xfs_btree_cur *cur,
903 union xfs_btree_ptr *ptr)
904{
905 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
33ad965d 906 ptr->l = cpu_to_be64(NULLDFSBNO);
4b22a571
CH		 907 else
908 ptr->s = cpu_to_be32(NULLAGBLOCK);
909}
910
637aa50f
CH		 911/*
912 * Get/set/init sibling pointers
913 */
914STATIC void
915xfs_btree_get_sibling(
916 struct xfs_btree_cur *cur,
917 struct xfs_btree_block *block,
918 union xfs_btree_ptr *ptr,
919 int lr)
920{
921 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
922
923 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
924 if (lr == XFS_BB_RIGHTSIB)
925 ptr->l = block->bb_u.l.bb_rightsib;
926 else
927 ptr->l = block->bb_u.l.bb_leftsib;
928 } else {
929 if (lr == XFS_BB_RIGHTSIB)
930 ptr->s = block->bb_u.s.bb_rightsib;
931 else
932 ptr->s = block->bb_u.s.bb_leftsib;
933 }
934}
935
f5eb8e7c
CH		 936STATIC void
937xfs_btree_set_sibling(
938 struct xfs_btree_cur *cur,
939 struct xfs_btree_block *block,
940 union xfs_btree_ptr *ptr,
941 int lr)
942{
943 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
944
945 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
946 if (lr == XFS_BB_RIGHTSIB)
947 block->bb_u.l.bb_rightsib = ptr->l;
948 else
949 block->bb_u.l.bb_leftsib = ptr->l;
950 } else {
951 if (lr == XFS_BB_RIGHTSIB)
952 block->bb_u.s.bb_rightsib = ptr->s;
953 else
954 block->bb_u.s.bb_leftsib = ptr->s;
955 }
956}
957
ee1a47ab
CH		 958void
959xfs_btree_init_block_int(
960 struct xfs_mount *mp,
961 struct xfs_btree_block *buf,
962 xfs_daddr_t blkno,
963 __u32 magic,
964 __u16 level,
965 __u16 numrecs,
966 __u64 owner,
967 unsigned int flags)
968{
969 buf->bb_magic = cpu_to_be32(magic);
970 buf->bb_level = cpu_to_be16(level);
971 buf->bb_numrecs = cpu_to_be16(numrecs);
972
973 if (flags & XFS_BTREE_LONG_PTRS) {
974 buf->bb_u.l.bb_leftsib = cpu_to_be64(NULLDFSBNO);
975 buf->bb_u.l.bb_rightsib = cpu_to_be64(NULLDFSBNO);
976 if (flags & XFS_BTREE_CRC_BLOCKS) {
977 buf->bb_u.l.bb_blkno = cpu_to_be64(blkno);
978 buf->bb_u.l.bb_owner = cpu_to_be64(owner);
979 uuid_copy(&buf->bb_u.l.bb_uuid, &mp->m_sb.sb_uuid);
980 buf->bb_u.l.bb_pad = 0;
b58fa554 981 buf->bb_u.l.bb_lsn = 0;
ee1a47ab
CH		 982 }
983 } else {
984 /* owner is a 32 bit value on short blocks */
985 __u32 __owner = (__u32)owner;
986
987 buf->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
988 buf->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
989 if (flags & XFS_BTREE_CRC_BLOCKS) {
990 buf->bb_u.s.bb_blkno = cpu_to_be64(blkno);
991 buf->bb_u.s.bb_owner = cpu_to_be32(__owner);
992 uuid_copy(&buf->bb_u.s.bb_uuid, &mp->m_sb.sb_uuid);
b58fa554 993 buf->bb_u.s.bb_lsn = 0;
ee1a47ab
CH		 994 }
995 }
996}
997
b64f3a39 998void
f5eb8e7c 999xfs_btree_init_block(
b64f3a39
DC		 1000 struct xfs_mount *mp,
1001 struct xfs_buf *bp,
1002 __u32 magic,
1003 __u16 level,
1004 __u16 numrecs,
ee1a47ab 1005 __u64 owner,
b64f3a39 1006 unsigned int flags)
f5eb8e7c 1007{
ee1a47ab
CH		 1008 xfs_btree_init_block_int(mp, XFS_BUF_TO_BLOCK(bp), bp->b_bn,
1009 magic, level, numrecs, owner, flags);
f5eb8e7c
CH		 1010}
1011
b64f3a39
DC		 1012STATIC void
1013xfs_btree_init_block_cur(
1014 struct xfs_btree_cur *cur,
ee1a47ab 1015 struct xfs_buf *bp,
b64f3a39 1016 int level,
ee1a47ab 1017 int numrecs)
b64f3a39 1018{
ee1a47ab
CH		 1019 __u64 owner;
1020
1021 /*
1022 * we can pull the owner from the cursor right now as the different
1023 * owners align directly with the pointer size of the btree. This may
1024 * change in future, but is safe for current users of the generic btree
1025 * code.
1026 */
1027 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1028 owner = cur->bc_private.b.ip->i_ino;
1029 else
1030 owner = cur->bc_private.a.agno;
1031
1032 xfs_btree_init_block_int(cur->bc_mp, XFS_BUF_TO_BLOCK(bp), bp->b_bn,
1033 xfs_btree_magic(cur), level, numrecs,
1034 owner, cur->bc_flags);
b64f3a39
DC		 1035}
1036
278d0ca1
CH		 1037/*
1038 * Return true if ptr is the last record in the btree and
ee1a47ab 1039 * we need to track updates to this record. The decision
278d0ca1
CH		 1040 * will be further refined in the update_lastrec method.
1041 */
1042STATIC int
1043xfs_btree_is_lastrec(
1044 struct xfs_btree_cur *cur,
1045 struct xfs_btree_block *block,
1046 int level)
1047{
1048 union xfs_btree_ptr ptr;
1049
1050 if (level > 0)
1051 return 0;
1052 if (!(cur->bc_flags & XFS_BTREE_LASTREC_UPDATE))
1053 return 0;
1054
1055 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1056 if (!xfs_btree_ptr_is_null(cur, &ptr))
1057 return 0;
1058 return 1;
1059}
1060
f5eb8e7c
CH		 1061STATIC void
1062xfs_btree_buf_to_ptr(
1063 struct xfs_btree_cur *cur,
1064 struct xfs_buf *bp,
1065 union xfs_btree_ptr *ptr)
1066{
1067 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1068 ptr->l = cpu_to_be64(XFS_DADDR_TO_FSB(cur->bc_mp,
1069 XFS_BUF_ADDR(bp)));
1070 else {
9d87c319 1071 ptr->s = cpu_to_be32(xfs_daddr_to_agbno(cur->bc_mp,
f5eb8e7c
CH		 1072 XFS_BUF_ADDR(bp)));
1073 }
1074}
1075
637aa50f
CH		 1076STATIC xfs_daddr_t
1077xfs_btree_ptr_to_daddr(
1078 struct xfs_btree_cur *cur,
1079 union xfs_btree_ptr *ptr)
1080{
1081 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
69ef921b 1082 ASSERT(ptr->l != cpu_to_be64(NULLDFSBNO));
637aa50f
CH		 1083
1084 return XFS_FSB_TO_DADDR(cur->bc_mp, be64_to_cpu(ptr->l));
1085 } else {
1086 ASSERT(cur->bc_private.a.agno != NULLAGNUMBER);
69ef921b 1087 ASSERT(ptr->s != cpu_to_be32(NULLAGBLOCK));
637aa50f
CH		 1088
1089 return XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_private.a.agno,
1090 be32_to_cpu(ptr->s));
1091 }
1092}
1093
1094STATIC void
1095xfs_btree_set_refs(
1096 struct xfs_btree_cur *cur,
1097 struct xfs_buf *bp)
1098{
1099 switch (cur->bc_btnum) {
1100 case XFS_BTNUM_BNO:
1101 case XFS_BTNUM_CNT:
38f23232 1102 xfs_buf_set_ref(bp, XFS_ALLOC_BTREE_REF);
637aa50f
CH		 1103 break;
1104 case XFS_BTNUM_INO:
38f23232 1105 xfs_buf_set_ref(bp, XFS_INO_BTREE_REF);
637aa50f
CH		 1106 break;
1107 case XFS_BTNUM_BMAP:
38f23232 1108 xfs_buf_set_ref(bp, XFS_BMAP_BTREE_REF);
637aa50f
CH		 1109 break;
1110 default:
1111 ASSERT(0);
1112 }
1113}
1114
f5eb8e7c
CH		 1115STATIC int
1116xfs_btree_get_buf_block(
1117 struct xfs_btree_cur *cur,
1118 union xfs_btree_ptr *ptr,
1119 int flags,
1120 struct xfs_btree_block **block,
1121 struct xfs_buf **bpp)
1122{
1123 struct xfs_mount *mp = cur->bc_mp;
1124 xfs_daddr_t d;
1125
1126 /* need to sort out how callers deal with failures first */
0cadda1c 1127 ASSERT(!(flags & XBF_TRYLOCK));
f5eb8e7c
CH		 1128
1129 d = xfs_btree_ptr_to_daddr(cur, ptr);
1130 *bpp = xfs_trans_get_buf(cur->bc_tp, mp->m_ddev_targp, d,
1131 mp->m_bsize, flags);
1132
2a30f36d
CS		 1133 if (!*bpp)
1134 return ENOMEM;
f5eb8e7c 1135
1813dd64 1136 (*bpp)->b_ops = cur->bc_ops->buf_ops;
f5eb8e7c
CH		 1137 *block = XFS_BUF_TO_BLOCK(*bpp);
1138 return 0;
1139}
1140
637aa50f
CH		 1141/*
1142 * Read in the buffer at the given ptr and return the buffer and
1143 * the block pointer within the buffer.
1144 */
1145STATIC int
1146xfs_btree_read_buf_block(
1147 struct xfs_btree_cur *cur,
1148 union xfs_btree_ptr *ptr,
1149 int level,
1150 int flags,
1151 struct xfs_btree_block **block,
1152 struct xfs_buf **bpp)
1153{
1154 struct xfs_mount *mp = cur->bc_mp;
1155 xfs_daddr_t d;
1156 int error;
1157
1158 /* need to sort out how callers deal with failures first */
0cadda1c 1159 ASSERT(!(flags & XBF_TRYLOCK));
637aa50f
CH		 1160
1161 d = xfs_btree_ptr_to_daddr(cur, ptr);
1162 error = xfs_trans_read_buf(mp, cur->bc_tp, mp->m_ddev_targp, d,
3d3e6f64 1163 mp->m_bsize, flags, bpp,
1813dd64 1164 cur->bc_ops->buf_ops);
637aa50f
CH		 1165 if (error)
1166 return error;
1167
5a52c2a5 1168 ASSERT(!xfs_buf_geterror(*bpp));
637aa50f
CH		 1169 xfs_btree_set_refs(cur, *bpp);
1170 *block = XFS_BUF_TO_BLOCK(*bpp);
3d3e6f64 1171 return 0;
637aa50f
CH		 1172}
1173
38bb7423
CH		 1174/*
1175 * Copy keys from one btree block to another.
1176 */
1177STATIC void
1178xfs_btree_copy_keys(
1179 struct xfs_btree_cur *cur,
1180 union xfs_btree_key *dst_key,
1181 union xfs_btree_key *src_key,
1182 int numkeys)
1183{
1184 ASSERT(numkeys >= 0);
1185 memcpy(dst_key, src_key, numkeys * cur->bc_ops->key_len);
1186}
1187
278d0ca1
CH		 1188/*
1189 * Copy records from one btree block to another.
1190 */
1191STATIC void
1192xfs_btree_copy_recs(
1193 struct xfs_btree_cur *cur,
1194 union xfs_btree_rec *dst_rec,
1195 union xfs_btree_rec *src_rec,
1196 int numrecs)
1197{
1198 ASSERT(numrecs >= 0);
1199 memcpy(dst_rec, src_rec, numrecs * cur->bc_ops->rec_len);
1200}
1201
9eaead51
CH		 1202/*
1203 * Copy block pointers from one btree block to another.
1204 */
1205STATIC void
1206xfs_btree_copy_ptrs(
1207 struct xfs_btree_cur *cur,
1208 union xfs_btree_ptr *dst_ptr,
1209 union xfs_btree_ptr *src_ptr,
1210 int numptrs)
1211{
1212 ASSERT(numptrs >= 0);
1213 memcpy(dst_ptr, src_ptr, numptrs * xfs_btree_ptr_len(cur));
1214}
1215
1216/*
1217 * Shift keys one index left/right inside a single btree block.
1218 */
1219STATIC void
1220xfs_btree_shift_keys(
1221 struct xfs_btree_cur *cur,
1222 union xfs_btree_key *key,
1223 int dir,
1224 int numkeys)
1225{
1226 char *dst_key;
1227
1228 ASSERT(numkeys >= 0);
1229 ASSERT(dir == 1 || dir == -1);
1230
1231 dst_key = (char *)key + (dir * cur->bc_ops->key_len);
1232 memmove(dst_key, key, numkeys * cur->bc_ops->key_len);
1233}
1234
1235/*
1236 * Shift records one index left/right inside a single btree block.
1237 */
1238STATIC void
1239xfs_btree_shift_recs(
1240 struct xfs_btree_cur *cur,
1241 union xfs_btree_rec *rec,
1242 int dir,
1243 int numrecs)
1244{
1245 char *dst_rec;
1246
1247 ASSERT(numrecs >= 0);
1248 ASSERT(dir == 1 || dir == -1);
1249
1250 dst_rec = (char *)rec + (dir * cur->bc_ops->rec_len);
1251 memmove(dst_rec, rec, numrecs * cur->bc_ops->rec_len);
1252}
1253
1254/*
1255 * Shift block pointers one index left/right inside a single btree block.
1256 */
1257STATIC void
1258xfs_btree_shift_ptrs(
1259 struct xfs_btree_cur *cur,
1260 union xfs_btree_ptr *ptr,
1261 int dir,
1262 int numptrs)
1263{
1264 char *dst_ptr;
1265
1266 ASSERT(numptrs >= 0);
1267 ASSERT(dir == 1 || dir == -1);
1268
1269 dst_ptr = (char *)ptr + (dir * xfs_btree_ptr_len(cur));
1270 memmove(dst_ptr, ptr, numptrs * xfs_btree_ptr_len(cur));
1271}
1272
38bb7423
CH		 1273/*
1274 * Log key values from the btree block.
1275 */
1276STATIC void
1277xfs_btree_log_keys(
1278 struct xfs_btree_cur *cur,
1279 struct xfs_buf *bp,
1280 int first,
1281 int last)
1282{
1283 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1284 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1285
1286 if (bp) {
61fe135c 1287 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
38bb7423
CH		 1288 xfs_trans_log_buf(cur->bc_tp, bp,
1289 xfs_btree_key_offset(cur, first),
1290 xfs_btree_key_offset(cur, last + 1) - 1);
1291 } else {
1292 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1293 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1294 }
1295
1296 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1297}
1298
278d0ca1
CH		 1299/*
1300 * Log record values from the btree block.
1301 */
fd6bcc5b 1302void
278d0ca1
CH		 1303xfs_btree_log_recs(
1304 struct xfs_btree_cur *cur,
1305 struct xfs_buf *bp,
1306 int first,
1307 int last)
1308{
1309 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1310 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1311
61fe135c 1312 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
278d0ca1
CH		 1313 xfs_trans_log_buf(cur->bc_tp, bp,
1314 xfs_btree_rec_offset(cur, first),
1315 xfs_btree_rec_offset(cur, last + 1) - 1);
1316
1317 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1318}
1319
9eaead51
CH		 1320/*
1321 * Log block pointer fields from a btree block (nonleaf).
1322 */
1323STATIC void
1324xfs_btree_log_ptrs(
1325 struct xfs_btree_cur *cur, /* btree cursor */
1326 struct xfs_buf *bp, /* buffer containing btree block */
1327 int first, /* index of first pointer to log */
1328 int last) /* index of last pointer to log */
1329{
1330 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1331 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1332
1333 if (bp) {
1334 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
1335 int level = xfs_btree_get_level(block);
1336
61fe135c 1337 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
9eaead51
CH		 1338 xfs_trans_log_buf(cur->bc_tp, bp,
1339 xfs_btree_ptr_offset(cur, first, level),
1340 xfs_btree_ptr_offset(cur, last + 1, level) - 1);
1341 } else {
1342 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1343 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1344 }
1345
1346 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1347}
1348
1349/*
1350 * Log fields from a btree block header.
1351 */
fd6bcc5b 1352void
9eaead51
CH		 1353xfs_btree_log_block(
1354 struct xfs_btree_cur *cur, /* btree cursor */
1355 struct xfs_buf *bp, /* buffer containing btree block */
1356 int fields) /* mask of fields: XFS_BB_... */
1357{
1358 int first; /* first byte offset logged */
1359 int last; /* last byte offset logged */
1360 static const short soffsets[] = { /* table of offsets (short) */
7cc95a82
CH		 1361 offsetof(struct xfs_btree_block, bb_magic),
1362 offsetof(struct xfs_btree_block, bb_level),
1363 offsetof(struct xfs_btree_block, bb_numrecs),
1364 offsetof(struct xfs_btree_block, bb_u.s.bb_leftsib),
1365 offsetof(struct xfs_btree_block, bb_u.s.bb_rightsib),
ee1a47ab
CH		 1366 offsetof(struct xfs_btree_block, bb_u.s.bb_blkno),
1367 offsetof(struct xfs_btree_block, bb_u.s.bb_lsn),
1368 offsetof(struct xfs_btree_block, bb_u.s.bb_uuid),
1369 offsetof(struct xfs_btree_block, bb_u.s.bb_owner),
1370 offsetof(struct xfs_btree_block, bb_u.s.bb_crc),
1371 XFS_BTREE_SBLOCK_CRC_LEN
9eaead51
CH		 1372 };
1373 static const short loffsets[] = { /* table of offsets (long) */
7cc95a82
CH		 1374 offsetof(struct xfs_btree_block, bb_magic),
1375 offsetof(struct xfs_btree_block, bb_level),
1376 offsetof(struct xfs_btree_block, bb_numrecs),
1377 offsetof(struct xfs_btree_block, bb_u.l.bb_leftsib),
1378 offsetof(struct xfs_btree_block, bb_u.l.bb_rightsib),
ee1a47ab
CH		 1379 offsetof(struct xfs_btree_block, bb_u.l.bb_blkno),
1380 offsetof(struct xfs_btree_block, bb_u.l.bb_lsn),
1381 offsetof(struct xfs_btree_block, bb_u.l.bb_uuid),
1382 offsetof(struct xfs_btree_block, bb_u.l.bb_owner),
1383 offsetof(struct xfs_btree_block, bb_u.l.bb_crc),
1384 offsetof(struct xfs_btree_block, bb_u.l.bb_pad),
1385 XFS_BTREE_LBLOCK_CRC_LEN
9eaead51
CH		 1386 };
1387
1388 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1389 XFS_BTREE_TRACE_ARGBI(cur, bp, fields);
1390
1391 if (bp) {
ee1a47ab
CH		 1392 int nbits;
1393
1394 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) {
1395 /*
1396 * We don't log the CRC when updating a btree
1397 * block but instead recreate it during log
1398 * recovery. As the log buffers have checksums
1399 * of their own this is safe and avoids logging a crc
1400 * update in a lot of places.
1401 */
1402 if (fields == XFS_BB_ALL_BITS)
1403 fields = XFS_BB_ALL_BITS_CRC;
1404 nbits = XFS_BB_NUM_BITS_CRC;
1405 } else {
1406 nbits = XFS_BB_NUM_BITS;
1407 }
9eaead51
CH		 1408 xfs_btree_offsets(fields,
1409 (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
1410 loffsets : soffsets,
ee1a47ab 1411 nbits, &first, &last);
61fe135c 1412 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
9eaead51
CH		 1413 xfs_trans_log_buf(cur->bc_tp, bp, first, last);
1414 } else {
1415 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1416 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1417 }
1418
1419 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1420}
1421
637aa50f
CH		 1422/*
1423 * Increment cursor by one record at the level.
1424 * For nonzero levels the leaf-ward information is untouched.
1425 */
1426int /* error */
1427xfs_btree_increment(
1428 struct xfs_btree_cur *cur,
1429 int level,
1430 int *stat) /* success/failure */
1431{
1432 struct xfs_btree_block *block;
1433 union xfs_btree_ptr ptr;
1434 struct xfs_buf *bp;
1435 int error; /* error return value */
1436 int lev;
1437
1438 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1439 XFS_BTREE_TRACE_ARGI(cur, level);
1440
1441 ASSERT(level < cur->bc_nlevels);
1442
1443 /* Read-ahead to the right at this level. */
1444 xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
1445
1446 /* Get a pointer to the btree block. */
1447 block = xfs_btree_get_block(cur, level, &bp);
1448
1449#ifdef DEBUG
1450 error = xfs_btree_check_block(cur, block, level, bp);
1451 if (error)
1452 goto error0;
1453#endif
1454
1455 /* We're done if we remain in the block after the increment. */
1456 if (++cur->bc_ptrs[level] <= xfs_btree_get_numrecs(block))
1457 goto out1;
1458
1459 /* Fail if we just went off the right edge of the tree. */
1460 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1461 if (xfs_btree_ptr_is_null(cur, &ptr))
1462 goto out0;
1463
1464 XFS_BTREE_STATS_INC(cur, increment);
1465
1466 /*
1467 * March up the tree incrementing pointers.
1468 * Stop when we don't go off the right edge of a block.
1469 */
1470 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1471 block = xfs_btree_get_block(cur, lev, &bp);
1472
1473#ifdef DEBUG
1474 error = xfs_btree_check_block(cur, block, lev, bp);
1475 if (error)
1476 goto error0;
1477#endif
1478
1479 if (++cur->bc_ptrs[lev] <= xfs_btree_get_numrecs(block))
1480 break;
1481
1482 /* Read-ahead the right block for the next loop. */
1483 xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA);
1484 }
1485
1486 /*
1487 * If we went off the root then we are either seriously
1488 * confused or have the tree root in an inode.
1489 */
1490 if (lev == cur->bc_nlevels) {
1491 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1492 goto out0;
1493 ASSERT(0);
1494 error = EFSCORRUPTED;
1495 goto error0;
1496 }
1497 ASSERT(lev < cur->bc_nlevels);
1498
1499 /*
1500 * Now walk back down the tree, fixing up the cursor's buffer
1501 * pointers and key numbers.
1502 */
1503 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1504 union xfs_btree_ptr *ptrp;
1505
1506 ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1507 error = xfs_btree_read_buf_block(cur, ptrp, --lev,
1508 0, &block, &bp);
1509 if (error)
1510 goto error0;
1511
1512 xfs_btree_setbuf(cur, lev, bp);
1513 cur->bc_ptrs[lev] = 1;
1514 }
1515out1:
1516 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1517 *stat = 1;
1518 return 0;
1519
1520out0:
1521 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1522 *stat = 0;
1523 return 0;
1524
1525error0:
1526 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1527 return error;
1528}
8df4da4a
CH		 1529
1530/*
1531 * Decrement cursor by one record at the level.
1532 * For nonzero levels the leaf-ward information is untouched.
1533 */
1534int /* error */
1535xfs_btree_decrement(
1536 struct xfs_btree_cur *cur,
1537 int level,
1538 int *stat) /* success/failure */
1539{
1540 struct xfs_btree_block *block;
1541 xfs_buf_t *bp;
1542 int error; /* error return value */
1543 int lev;
1544 union xfs_btree_ptr ptr;
1545
1546 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1547 XFS_BTREE_TRACE_ARGI(cur, level);
1548
1549 ASSERT(level < cur->bc_nlevels);
1550
1551 /* Read-ahead to the left at this level. */
1552 xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA);
1553
1554 /* We're done if we remain in the block after the decrement. */
1555 if (--cur->bc_ptrs[level] > 0)
1556 goto out1;
1557
1558 /* Get a pointer to the btree block. */
1559 block = xfs_btree_get_block(cur, level, &bp);
1560
1561#ifdef DEBUG
1562 error = xfs_btree_check_block(cur, block, level, bp);
1563 if (error)
1564 goto error0;
1565#endif
1566
1567 /* Fail if we just went off the left edge of the tree. */
1568 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
1569 if (xfs_btree_ptr_is_null(cur, &ptr))
1570 goto out0;
1571
1572 XFS_BTREE_STATS_INC(cur, decrement);
1573
1574 /*
1575 * March up the tree decrementing pointers.
1576 * Stop when we don't go off the left edge of a block.
1577 */
1578 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1579 if (--cur->bc_ptrs[lev] > 0)
1580 break;
1581 /* Read-ahead the left block for the next loop. */
1582 xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA);
1583 }
1584
1585 /*
1586 * If we went off the root then we are seriously confused.
1587 * or the root of the tree is in an inode.
1588 */
1589 if (lev == cur->bc_nlevels) {
1590 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1591 goto out0;
1592 ASSERT(0);
1593 error = EFSCORRUPTED;
1594 goto error0;
1595 }
1596 ASSERT(lev < cur->bc_nlevels);
1597
1598 /*
1599 * Now walk back down the tree, fixing up the cursor's buffer
1600 * pointers and key numbers.
1601 */
1602 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1603 union xfs_btree_ptr *ptrp;
1604
1605 ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1606 error = xfs_btree_read_buf_block(cur, ptrp, --lev,
1607 0, &block, &bp);
1608 if (error)
1609 goto error0;
1610 xfs_btree_setbuf(cur, lev, bp);
1611 cur->bc_ptrs[lev] = xfs_btree_get_numrecs(block);
1612 }
1613out1:
1614 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1615 *stat = 1;
1616 return 0;
1617
1618out0:
1619 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1620 *stat = 0;
1621 return 0;
1622
1623error0:
1624 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1625 return error;
1626}
1627
fe033cc8
CH		 1628STATIC int
1629xfs_btree_lookup_get_block(
1630 struct xfs_btree_cur *cur, /* btree cursor */
1631 int level, /* level in the btree */
1632 union xfs_btree_ptr *pp, /* ptr to btree block */
1633 struct xfs_btree_block **blkp) /* return btree block */
1634{
1635 struct xfs_buf *bp; /* buffer pointer for btree block */
1636 int error = 0;
1637
1638 /* special case the root block if in an inode */
1639 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1640 (level == cur->bc_nlevels - 1)) {
1641 *blkp = xfs_btree_get_iroot(cur);
1642 return 0;
1643 }
1644
1645 /*
1646 * If the old buffer at this level for the disk address we are
1647 * looking for re-use it.
1648 *
1649 * Otherwise throw it away and get a new one.
1650 */
1651 bp = cur->bc_bufs[level];
1652 if (bp && XFS_BUF_ADDR(bp) == xfs_btree_ptr_to_daddr(cur, pp)) {
1653 *blkp = XFS_BUF_TO_BLOCK(bp);
1654 return 0;
1655 }
1656
1657 error = xfs_btree_read_buf_block(cur, pp, level, 0, blkp, &bp);
1658 if (error)
1659 return error;
1660
1661 xfs_btree_setbuf(cur, level, bp);
1662 return 0;
1663}
1664
1665/*
1666 * Get current search key. For level 0 we don't actually have a key
1667 * structure so we make one up from the record. For all other levels
1668 * we just return the right key.
1669 */
1670STATIC union xfs_btree_key *
1671xfs_lookup_get_search_key(
1672 struct xfs_btree_cur *cur,
1673 int level,
1674 int keyno,
1675 struct xfs_btree_block *block,
1676 union xfs_btree_key *kp)
1677{
1678 if (level == 0) {
1679 cur->bc_ops->init_key_from_rec(kp,
1680 xfs_btree_rec_addr(cur, keyno, block));
1681 return kp;
1682 }
1683
1684 return xfs_btree_key_addr(cur, keyno, block);
1685}
1686
1687/*
1688 * Lookup the record. The cursor is made to point to it, based on dir.
49d3da14 1689 * stat is set to 0 if can't find any such record, 1 for success.
fe033cc8
CH		 1690 */
1691int /* error */
1692xfs_btree_lookup(
1693 struct xfs_btree_cur *cur, /* btree cursor */
1694 xfs_lookup_t dir, /* <=, ==, or >= */
1695 int *stat) /* success/failure */
1696{
1697 struct xfs_btree_block *block; /* current btree block */
1698 __int64_t diff; /* difference for the current key */
1699 int error; /* error return value */
1700 int keyno; /* current key number */
1701 int level; /* level in the btree */
1702 union xfs_btree_ptr *pp; /* ptr to btree block */
1703 union xfs_btree_ptr ptr; /* ptr to btree block */
1704
1705 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1706 XFS_BTREE_TRACE_ARGI(cur, dir);
1707
1708 XFS_BTREE_STATS_INC(cur, lookup);
1709
1710 block = NULL;
1711 keyno = 0;
1712
1713 /* initialise start pointer from cursor */
1714 cur->bc_ops->init_ptr_from_cur(cur, &ptr);
1715 pp = &ptr;
1716
1717 /*
1718 * Iterate over each level in the btree, starting at the root.
1719 * For each level above the leaves, find the key we need, based
1720 * on the lookup record, then follow the corresponding block
1721 * pointer down to the next level.
1722 */
1723 for (level = cur->bc_nlevels - 1, diff = 1; level >= 0; level--) {
1724 /* Get the block we need to do the lookup on. */
1725 error = xfs_btree_lookup_get_block(cur, level, pp, &block);
1726 if (error)
1727 goto error0;
1728
1729 if (diff == 0) {
1730 /*
1731 * If we already had a key match at a higher level, we
1732 * know we need to use the first entry in this block.
1733 */
1734 keyno = 1;
1735 } else {
1736 /* Otherwise search this block. Do a binary search. */
1737
1738 int high; /* high entry number */
1739 int low; /* low entry number */
1740
1741 /* Set low and high entry numbers, 1-based. */
1742 low = 1;
1743 high = xfs_btree_get_numrecs(block);
1744 if (!high) {
1745 /* Block is empty, must be an empty leaf. */
1746 ASSERT(level == 0 && cur->bc_nlevels == 1);
1747
1748 cur->bc_ptrs[0] = dir != XFS_LOOKUP_LE;
1749 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1750 *stat = 0;
1751 return 0;
1752 }
1753
1754 /* Binary search the block. */
1755 while (low <= high) {
1756 union xfs_btree_key key;
1757 union xfs_btree_key *kp;
1758
1759 XFS_BTREE_STATS_INC(cur, compare);
1760
1761 /* keyno is average of low and high. */
1762 keyno = (low + high) >> 1;
1763
1764 /* Get current search key */
1765 kp = xfs_lookup_get_search_key(cur, level,
1766 keyno, block, &key);
1767
1768 /*
1769 * Compute difference to get next direction:
1770 * - less than, move right
1771 * - greater than, move left
1772 * - equal, we're done
1773 */
1774 diff = cur->bc_ops->key_diff(cur, kp);
1775 if (diff < 0)
1776 low = keyno + 1;
1777 else if (diff > 0)
1778 high = keyno - 1;
1779 else
1780 break;
1781 }
1782 }
1783
1784 /*
1785 * If there are more levels, set up for the next level
1786 * by getting the block number and filling in the cursor.
1787 */
1788 if (level > 0) {
1789 /*
1790 * If we moved left, need the previous key number,
1791 * unless there isn't one.
1792 */
1793 if (diff > 0 && --keyno < 1)
1794 keyno = 1;
1795 pp = xfs_btree_ptr_addr(cur, keyno, block);
1796
1797#ifdef DEBUG
1798 error = xfs_btree_check_ptr(cur, pp, 0, level);
1799 if (error)
1800 goto error0;
1801#endif
1802 cur->bc_ptrs[level] = keyno;
1803 }
1804 }
1805
1806 /* Done with the search. See if we need to adjust the results. */
1807 if (dir != XFS_LOOKUP_LE && diff < 0) {
1808 keyno++;
1809 /*
1810 * If ge search and we went off the end of the block, but it's
1811 * not the last block, we're in the wrong block.
1812 */
1813 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1814 if (dir == XFS_LOOKUP_GE &&
1815 keyno > xfs_btree_get_numrecs(block) &&
1816 !xfs_btree_ptr_is_null(cur, &ptr)) {
1817 int i;
1818
1819 cur->bc_ptrs[0] = keyno;
1820 error = xfs_btree_increment(cur, 0, &i);
1821 if (error)
1822 goto error0;
1823 XFS_WANT_CORRUPTED_RETURN(i == 1);
1824 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1825 *stat = 1;
1826 return 0;
1827 }
1828 } else if (dir == XFS_LOOKUP_LE && diff > 0)
1829 keyno--;
1830 cur->bc_ptrs[0] = keyno;
1831
1832 /* Return if we succeeded or not. */
1833 if (keyno == 0 || keyno > xfs_btree_get_numrecs(block))
1834 *stat = 0;
1835 else if (dir != XFS_LOOKUP_EQ || diff == 0)
1836 *stat = 1;
1837 else
1838 *stat = 0;
1839 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1840 return 0;
1841
1842error0:
1843 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1844 return error;
1845}
38bb7423
CH		 1846
1847/*
1848 * Update keys at all levels from here to the root along the cursor's path.
1849 */
3cc7524c 1850STATIC int
38bb7423
CH		 1851xfs_btree_updkey(
1852 struct xfs_btree_cur *cur,
1853 union xfs_btree_key *keyp,
1854 int level)
1855{
1856 struct xfs_btree_block *block;
1857 struct xfs_buf *bp;
1858 union xfs_btree_key *kp;
1859 int ptr;
1860
1861 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1862 XFS_BTREE_TRACE_ARGIK(cur, level, keyp);
1863
1864 ASSERT(!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) || level >= 1);
1865
1866 /*
1867 * Go up the tree from this level toward the root.
1868 * At each level, update the key value to the value input.
1869 * Stop when we reach a level where the cursor isn't pointing
1870 * at the first entry in the block.
1871 */
1872 for (ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) {
1873#ifdef DEBUG
1874 int error;
1875#endif
1876 block = xfs_btree_get_block(cur, level, &bp);
1877#ifdef DEBUG
1878 error = xfs_btree_check_block(cur, block, level, bp);
1879 if (error) {
1880 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1881 return error;
1882 }
1883#endif
1884 ptr = cur->bc_ptrs[level];
1885 kp = xfs_btree_key_addr(cur, ptr, block);
1886 xfs_btree_copy_keys(cur, kp, keyp, 1);
1887 xfs_btree_log_keys(cur, bp, ptr, ptr);
1888 }
1889
1890 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1891 return 0;
1892}
278d0ca1
CH		 1893
1894/*
1895 * Update the record referred to by cur to the value in the
1896 * given record. This either works (return 0) or gets an
1897 * EFSCORRUPTED error.
1898 */
1899int
1900xfs_btree_update(
1901 struct xfs_btree_cur *cur,
1902 union xfs_btree_rec *rec)
1903{
1904 struct xfs_btree_block *block;
1905 struct xfs_buf *bp;
1906 int error;
1907 int ptr;
1908 union xfs_btree_rec *rp;
1909
1910 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1911 XFS_BTREE_TRACE_ARGR(cur, rec);
1912
1913 /* Pick up the current block. */
1914 block = xfs_btree_get_block(cur, 0, &bp);
1915
1916#ifdef DEBUG
1917 error = xfs_btree_check_block(cur, block, 0, bp);
1918 if (error)
1919 goto error0;
1920#endif
1921 /* Get the address of the rec to be updated. */
1922 ptr = cur->bc_ptrs[0];
1923 rp = xfs_btree_rec_addr(cur, ptr, block);
1924
1925 /* Fill in the new contents and log them. */
1926 xfs_btree_copy_recs(cur, rp, rec, 1);
1927 xfs_btree_log_recs(cur, bp, ptr, ptr);
1928
1929 /*
1930 * If we are tracking the last record in the tree and
1931 * we are at the far right edge of the tree, update it.
1932 */
1933 if (xfs_btree_is_lastrec(cur, block, 0)) {
1934 cur->bc_ops->update_lastrec(cur, block, rec,
1935 ptr, LASTREC_UPDATE);
1936 }
1937
1938 /* Updating first rec in leaf. Pass new key value up to our parent. */
1939 if (ptr == 1) {
1940 union xfs_btree_key key;
1941
1942 cur->bc_ops->init_key_from_rec(&key, rec);
1943 error = xfs_btree_updkey(cur, &key, 1);
1944 if (error)
1945 goto error0;
1946 }
1947
1948 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1949 return 0;
1950
1951error0:
1952 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1953 return error;
1954}
1955
687b890a
CH		 1956/*
1957 * Move 1 record left from cur/level if possible.
1958 * Update cur to reflect the new path.
1959 */
3cc7524c 1960STATIC int /* error */
687b890a
CH		 1961xfs_btree_lshift(
1962 struct xfs_btree_cur *cur,
1963 int level,
1964 int *stat) /* success/failure */
1965{
1966 union xfs_btree_key key; /* btree key */
1967 struct xfs_buf *lbp; /* left buffer pointer */
1968 struct xfs_btree_block *left; /* left btree block */
1969 int lrecs; /* left record count */
1970 struct xfs_buf *rbp; /* right buffer pointer */
1971 struct xfs_btree_block *right; /* right btree block */
1972 int rrecs; /* right record count */
1973 union xfs_btree_ptr lptr; /* left btree pointer */
1974 union xfs_btree_key *rkp = NULL; /* right btree key */
1975 union xfs_btree_ptr *rpp = NULL; /* right address pointer */
1976 union xfs_btree_rec *rrp = NULL; /* right record pointer */
1977 int error; /* error return value */
1978
1979 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1980 XFS_BTREE_TRACE_ARGI(cur, level);
1981
1982 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1983 level == cur->bc_nlevels - 1)
1984 goto out0;
1985
1986 /* Set up variables for this block as "right". */
1987 right = xfs_btree_get_block(cur, level, &rbp);
1988
1989#ifdef DEBUG
1990 error = xfs_btree_check_block(cur, right, level, rbp);
1991 if (error)
1992 goto error0;
1993#endif
1994
1995 /* If we've got no left sibling then we can't shift an entry left. */
1996 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
1997 if (xfs_btree_ptr_is_null(cur, &lptr))
1998 goto out0;
1999
2000 /*
2001 * If the cursor entry is the one that would be moved, don't
2002 * do it... it's too complicated.
2003 */
2004 if (cur->bc_ptrs[level] <= 1)
2005 goto out0;
2006
2007 /* Set up the left neighbor as "left". */
2008 error = xfs_btree_read_buf_block(cur, &lptr, level, 0, &left, &lbp);
2009 if (error)
2010 goto error0;
2011
2012 /* If it's full, it can't take another entry. */
2013 lrecs = xfs_btree_get_numrecs(left);
2014 if (lrecs == cur->bc_ops->get_maxrecs(cur, level))
2015 goto out0;
2016
2017 rrecs = xfs_btree_get_numrecs(right);
2018
2019 /*
2020 * We add one entry to the left side and remove one for the right side.
9da096fd 2021 * Account for it here, the changes will be updated on disk and logged
687b890a
CH		 2022 * later.
2023 */
2024 lrecs++;
2025 rrecs--;
2026
2027 XFS_BTREE_STATS_INC(cur, lshift);
2028 XFS_BTREE_STATS_ADD(cur, moves, 1);
2029
2030 /*
2031 * If non-leaf, copy a key and a ptr to the left block.
2032 * Log the changes to the left block.
2033 */
2034 if (level > 0) {
2035 /* It's a non-leaf. Move keys and pointers. */
2036 union xfs_btree_key *lkp; /* left btree key */
2037 union xfs_btree_ptr *lpp; /* left address pointer */
2038
2039 lkp = xfs_btree_key_addr(cur, lrecs, left);
2040 rkp = xfs_btree_key_addr(cur, 1, right);
2041
2042 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2043 rpp = xfs_btree_ptr_addr(cur, 1, right);
2044#ifdef DEBUG
2045 error = xfs_btree_check_ptr(cur, rpp, 0, level);
2046 if (error)
2047 goto error0;
2048#endif
2049 xfs_btree_copy_keys(cur, lkp, rkp, 1);
2050 xfs_btree_copy_ptrs(cur, lpp, rpp, 1);
2051
2052 xfs_btree_log_keys(cur, lbp, lrecs, lrecs);
2053 xfs_btree_log_ptrs(cur, lbp, lrecs, lrecs);
2054
4a26e66e
CH		 2055 ASSERT(cur->bc_ops->keys_inorder(cur,
2056 xfs_btree_key_addr(cur, lrecs - 1, left), lkp));
687b890a
CH		 2057 } else {
2058 /* It's a leaf. Move records. */
2059 union xfs_btree_rec *lrp; /* left record pointer */
2060
2061 lrp = xfs_btree_rec_addr(cur, lrecs, left);
2062 rrp = xfs_btree_rec_addr(cur, 1, right);
2063
2064 xfs_btree_copy_recs(cur, lrp, rrp, 1);
2065 xfs_btree_log_recs(cur, lbp, lrecs, lrecs);
2066
4a26e66e
CH		 2067 ASSERT(cur->bc_ops->recs_inorder(cur,
2068 xfs_btree_rec_addr(cur, lrecs - 1, left), lrp));
687b890a
CH		 2069 }
2070
2071 xfs_btree_set_numrecs(left, lrecs);
2072 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2073
2074 xfs_btree_set_numrecs(right, rrecs);
2075 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2076
2077 /*
2078 * Slide the contents of right down one entry.
2079 */
2080 XFS_BTREE_STATS_ADD(cur, moves, rrecs - 1);
2081 if (level > 0) {
2082 /* It's a nonleaf. operate on keys and ptrs */
2083#ifdef DEBUG
2084 int i; /* loop index */
2085
2086 for (i = 0; i < rrecs; i++) {
2087 error = xfs_btree_check_ptr(cur, rpp, i + 1, level);
2088 if (error)
2089 goto error0;
2090 }
2091#endif
2092 xfs_btree_shift_keys(cur,
2093 xfs_btree_key_addr(cur, 2, right),
2094 -1, rrecs);
2095 xfs_btree_shift_ptrs(cur,
2096 xfs_btree_ptr_addr(cur, 2, right),
2097 -1, rrecs);
2098
2099 xfs_btree_log_keys(cur, rbp, 1, rrecs);
2100 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2101 } else {
2102 /* It's a leaf. operate on records */
2103 xfs_btree_shift_recs(cur,
2104 xfs_btree_rec_addr(cur, 2, right),
2105 -1, rrecs);
2106 xfs_btree_log_recs(cur, rbp, 1, rrecs);
2107
2108 /*
2109 * If it's the first record in the block, we'll need a key
2110 * structure to pass up to the next level (updkey).
2111 */
2112 cur->bc_ops->init_key_from_rec(&key,
2113 xfs_btree_rec_addr(cur, 1, right));
2114 rkp = &key;
2115 }
2116
2117 /* Update the parent key values of right. */
2118 error = xfs_btree_updkey(cur, rkp, level + 1);
2119 if (error)
2120 goto error0;
2121
2122 /* Slide the cursor value left one. */
2123 cur->bc_ptrs[level]--;
2124
2125 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2126 *stat = 1;
2127 return 0;
2128
2129out0:
2130 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2131 *stat = 0;
2132 return 0;
2133
2134error0:
2135 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2136 return error;
2137}
2138
9eaead51
CH		 2139/*
2140 * Move 1 record right from cur/level if possible.
2141 * Update cur to reflect the new path.
2142 */
3cc7524c 2143STATIC int /* error */
9eaead51
CH		 2144xfs_btree_rshift(
2145 struct xfs_btree_cur *cur,
2146 int level,
2147 int *stat) /* success/failure */
2148{
2149 union xfs_btree_key key; /* btree key */
2150 struct xfs_buf *lbp; /* left buffer pointer */
2151 struct xfs_btree_block *left; /* left btree block */
2152 struct xfs_buf *rbp; /* right buffer pointer */
2153 struct xfs_btree_block *right; /* right btree block */
2154 struct xfs_btree_cur *tcur; /* temporary btree cursor */
2155 union xfs_btree_ptr rptr; /* right block pointer */
2156 union xfs_btree_key *rkp; /* right btree key */
2157 int rrecs; /* right record count */
2158 int lrecs; /* left record count */
2159 int error; /* error return value */
2160 int i; /* loop counter */
2161
2162 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2163 XFS_BTREE_TRACE_ARGI(cur, level);
2164
2165 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2166 (level == cur->bc_nlevels - 1))
2167 goto out0;
2168
2169 /* Set up variables for this block as "left". */
2170 left = xfs_btree_get_block(cur, level, &lbp);
2171
2172#ifdef DEBUG
2173 error = xfs_btree_check_block(cur, left, level, lbp);
2174 if (error)
2175 goto error0;
2176#endif
2177
2178 /* If we've got no right sibling then we can't shift an entry right. */
2179 xfs_btree_get_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2180 if (xfs_btree_ptr_is_null(cur, &rptr))
2181 goto out0;
2182
2183 /*
2184 * If the cursor entry is the one that would be moved, don't
2185 * do it... it's too complicated.
2186 */
2187 lrecs = xfs_btree_get_numrecs(left);
2188 if (cur->bc_ptrs[level] >= lrecs)
2189 goto out0;
2190
2191 /* Set up the right neighbor as "right". */
2192 error = xfs_btree_read_buf_block(cur, &rptr, level, 0, &right, &rbp);
2193 if (error)
2194 goto error0;
2195
2196 /* If it's full, it can't take another entry. */
2197 rrecs = xfs_btree_get_numrecs(right);
2198 if (rrecs == cur->bc_ops->get_maxrecs(cur, level))
2199 goto out0;
2200
2201 XFS_BTREE_STATS_INC(cur, rshift);
2202 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2203
2204 /*
2205 * Make a hole at the start of the right neighbor block, then
2206 * copy the last left block entry to the hole.
2207 */
2208 if (level > 0) {
2209 /* It's a nonleaf. make a hole in the keys and ptrs */
2210 union xfs_btree_key *lkp;
2211 union xfs_btree_ptr *lpp;
2212 union xfs_btree_ptr *rpp;
2213
2214 lkp = xfs_btree_key_addr(cur, lrecs, left);
2215 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2216 rkp = xfs_btree_key_addr(cur, 1, right);
2217 rpp = xfs_btree_ptr_addr(cur, 1, right);
2218
2219#ifdef DEBUG
2220 for (i = rrecs - 1; i >= 0; i--) {
2221 error = xfs_btree_check_ptr(cur, rpp, i, level);
2222 if (error)
2223 goto error0;
2224 }
2225#endif
2226
2227 xfs_btree_shift_keys(cur, rkp, 1, rrecs);
2228 xfs_btree_shift_ptrs(cur, rpp, 1, rrecs);
2229
2230#ifdef DEBUG
2231 error = xfs_btree_check_ptr(cur, lpp, 0, level);
2232 if (error)
2233 goto error0;
2234#endif
2235
2236 /* Now put the new data in, and log it. */
2237 xfs_btree_copy_keys(cur, rkp, lkp, 1);
2238 xfs_btree_copy_ptrs(cur, rpp, lpp, 1);
2239
2240 xfs_btree_log_keys(cur, rbp, 1, rrecs + 1);
2241 xfs_btree_log_ptrs(cur, rbp, 1, rrecs + 1);
2242
4a26e66e
CH		 2243 ASSERT(cur->bc_ops->keys_inorder(cur, rkp,
2244 xfs_btree_key_addr(cur, 2, right)));
9eaead51
CH		 2245 } else {
2246 /* It's a leaf. make a hole in the records */
2247 union xfs_btree_rec *lrp;
2248 union xfs_btree_rec *rrp;
2249
2250 lrp = xfs_btree_rec_addr(cur, lrecs, left);
2251 rrp = xfs_btree_rec_addr(cur, 1, right);
2252
2253 xfs_btree_shift_recs(cur, rrp, 1, rrecs);
2254
2255 /* Now put the new data in, and log it. */
2256 xfs_btree_copy_recs(cur, rrp, lrp, 1);
2257 xfs_btree_log_recs(cur, rbp, 1, rrecs + 1);
2258
2259 cur->bc_ops->init_key_from_rec(&key, rrp);
2260 rkp = &key;
2261
4a26e66e
CH		 2262 ASSERT(cur->bc_ops->recs_inorder(cur, rrp,
2263 xfs_btree_rec_addr(cur, 2, right)));
9eaead51
CH		 2264 }
2265
2266 /*
2267 * Decrement and log left's numrecs, bump and log right's numrecs.
2268 */
2269 xfs_btree_set_numrecs(left, --lrecs);
2270 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2271
2272 xfs_btree_set_numrecs(right, ++rrecs);
2273 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2274
2275 /*
2276 * Using a temporary cursor, update the parent key values of the
2277 * block on the right.
2278 */
2279 error = xfs_btree_dup_cursor(cur, &tcur);
2280 if (error)
2281 goto error0;
2282 i = xfs_btree_lastrec(tcur, level);
2283 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
2284
2285 error = xfs_btree_increment(tcur, level, &i);
2286 if (error)
2287 goto error1;
2288
2289 error = xfs_btree_updkey(tcur, rkp, level + 1);
2290 if (error)
2291 goto error1;
2292
2293 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
2294
2295 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2296 *stat = 1;
2297 return 0;
2298
2299out0:
2300 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2301 *stat = 0;
2302 return 0;
2303
2304error0:
2305 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2306 return error;
2307
2308error1:
2309 XFS_BTREE_TRACE_CURSOR(tcur, XBT_ERROR);
2310 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
2311 return error;
2312}
f5eb8e7c
CH		 2313
2314/*
2315 * Split cur/level block in half.
2316 * Return new block number and the key to its first
2317 * record (to be inserted into parent).
2318 */
3cc7524c 2319STATIC int /* error */
f5eb8e7c
CH		 2320xfs_btree_split(
2321 struct xfs_btree_cur *cur,
2322 int level,
2323 union xfs_btree_ptr *ptrp,
2324 union xfs_btree_key *key,
2325 struct xfs_btree_cur **curp,
2326 int *stat) /* success/failure */
2327{
2328 union xfs_btree_ptr lptr; /* left sibling block ptr */
2329 struct xfs_buf *lbp; /* left buffer pointer */
2330 struct xfs_btree_block *left; /* left btree block */
2331 union xfs_btree_ptr rptr; /* right sibling block ptr */
2332 struct xfs_buf *rbp; /* right buffer pointer */
2333 struct xfs_btree_block *right; /* right btree block */
2334 union xfs_btree_ptr rrptr; /* right-right sibling ptr */
2335 struct xfs_buf *rrbp; /* right-right buffer pointer */
2336 struct xfs_btree_block *rrblock; /* right-right btree block */
2337 int lrecs;
2338 int rrecs;
2339 int src_index;
2340 int error; /* error return value */
2341#ifdef DEBUG
2342 int i;
2343#endif
2344
2345 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2346 XFS_BTREE_TRACE_ARGIPK(cur, level, *ptrp, key);
2347
2348 XFS_BTREE_STATS_INC(cur, split);
2349
2350 /* Set up left block (current one). */
2351 left = xfs_btree_get_block(cur, level, &lbp);
2352
2353#ifdef DEBUG
2354 error = xfs_btree_check_block(cur, left, level, lbp);
2355 if (error)
2356 goto error0;
2357#endif
2358
2359 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2360
2361 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2362 error = cur->bc_ops->alloc_block(cur, &lptr, &rptr, 1, stat);
2363 if (error)
2364 goto error0;
2365 if (*stat == 0)
2366 goto out0;
2367 XFS_BTREE_STATS_INC(cur, alloc);
2368
2369 /* Set up the new block as "right". */
2370 error = xfs_btree_get_buf_block(cur, &rptr, 0, &right, &rbp);
2371 if (error)
2372 goto error0;
2373
2374 /* Fill in the btree header for the new right block. */
ee1a47ab 2375 xfs_btree_init_block_cur(cur, rbp, xfs_btree_get_level(left), 0);
f5eb8e7c
CH		 2376
2377 /*
2378 * Split the entries between the old and the new block evenly.
2379 * Make sure that if there's an odd number of entries now, that
2380 * each new block will have the same number of entries.
2381 */
2382 lrecs = xfs_btree_get_numrecs(left);
2383 rrecs = lrecs / 2;
2384 if ((lrecs & 1) && cur->bc_ptrs[level] <= rrecs + 1)
2385 rrecs++;
2386 src_index = (lrecs - rrecs + 1);
2387
2388 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2389
2390 /*
2391 * Copy btree block entries from the left block over to the
2392 * new block, the right. Update the right block and log the
2393 * changes.
2394 */
2395 if (level > 0) {
2396 /* It's a non-leaf. Move keys and pointers. */
2397 union xfs_btree_key *lkp; /* left btree key */
2398 union xfs_btree_ptr *lpp; /* left address pointer */
2399 union xfs_btree_key *rkp; /* right btree key */
2400 union xfs_btree_ptr *rpp; /* right address pointer */
2401
2402 lkp = xfs_btree_key_addr(cur, src_index, left);
2403 lpp = xfs_btree_ptr_addr(cur, src_index, left);
2404 rkp = xfs_btree_key_addr(cur, 1, right);
2405 rpp = xfs_btree_ptr_addr(cur, 1, right);
2406
2407#ifdef DEBUG
2408 for (i = src_index; i < rrecs; i++) {
2409 error = xfs_btree_check_ptr(cur, lpp, i, level);
2410 if (error)
2411 goto error0;
2412 }
2413#endif
2414
2415 xfs_btree_copy_keys(cur, rkp, lkp, rrecs);
2416 xfs_btree_copy_ptrs(cur, rpp, lpp, rrecs);
2417
2418 xfs_btree_log_keys(cur, rbp, 1, rrecs);
2419 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2420
2421 /* Grab the keys to the entries moved to the right block */
2422 xfs_btree_copy_keys(cur, key, rkp, 1);
2423 } else {
2424 /* It's a leaf. Move records. */
2425 union xfs_btree_rec *lrp; /* left record pointer */
2426 union xfs_btree_rec *rrp; /* right record pointer */
2427
2428 lrp = xfs_btree_rec_addr(cur, src_index, left);
2429 rrp = xfs_btree_rec_addr(cur, 1, right);
2430
2431 xfs_btree_copy_recs(cur, rrp, lrp, rrecs);
2432 xfs_btree_log_recs(cur, rbp, 1, rrecs);
2433
2434 cur->bc_ops->init_key_from_rec(key,
2435 xfs_btree_rec_addr(cur, 1, right));
2436 }
2437
2438
2439 /*
2440 * Find the left block number by looking in the buffer.
2441 * Adjust numrecs, sibling pointers.
2442 */
2443 xfs_btree_get_sibling(cur, left, &rrptr, XFS_BB_RIGHTSIB);
2444 xfs_btree_set_sibling(cur, right, &rrptr, XFS_BB_RIGHTSIB);
2445 xfs_btree_set_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2446 xfs_btree_set_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2447
2448 lrecs -= rrecs;
2449 xfs_btree_set_numrecs(left, lrecs);
2450 xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs);
2451
2452 xfs_btree_log_block(cur, rbp, XFS_BB_ALL_BITS);
2453 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
2454
2455 /*
2456 * If there's a block to the new block's right, make that block
2457 * point back to right instead of to left.
2458 */
2459 if (!xfs_btree_ptr_is_null(cur, &rrptr)) {
2460 error = xfs_btree_read_buf_block(cur, &rrptr, level,
2461 0, &rrblock, &rrbp);
2462 if (error)
2463 goto error0;
2464 xfs_btree_set_sibling(cur, rrblock, &rptr, XFS_BB_LEFTSIB);
2465 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
2466 }
2467 /*
2468 * If the cursor is really in the right block, move it there.
2469 * If it's just pointing past the last entry in left, then we'll
2470 * insert there, so don't change anything in that case.
2471 */
2472 if (cur->bc_ptrs[level] > lrecs + 1) {
2473 xfs_btree_setbuf(cur, level, rbp);
2474 cur->bc_ptrs[level] -= lrecs;
2475 }
2476 /*
2477 * If there are more levels, we'll need another cursor which refers
2478 * the right block, no matter where this cursor was.
2479 */
2480 if (level + 1 < cur->bc_nlevels) {
2481 error = xfs_btree_dup_cursor(cur, curp);
2482 if (error)
2483 goto error0;
2484 (*curp)->bc_ptrs[level + 1]++;
2485 }
2486 *ptrp = rptr;
2487 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2488 *stat = 1;
2489 return 0;
2490out0:
2491 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2492 *stat = 0;
2493 return 0;
2494
2495error0:
2496 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2497 return error;
2498}
344207ce 2499
ea77b0a6
CH		 2500/*
2501 * Copy the old inode root contents into a real block and make the
2502 * broot point to it.
2503 */
2504int /* error */
2505xfs_btree_new_iroot(
2506 struct xfs_btree_cur *cur, /* btree cursor */
2507 int *logflags, /* logging flags for inode */
2508 int *stat) /* return status - 0 fail */
2509{
2510 struct xfs_buf *cbp; /* buffer for cblock */
2511 struct xfs_btree_block *block; /* btree block */
2512 struct xfs_btree_block *cblock; /* child btree block */
2513 union xfs_btree_key *ckp; /* child key pointer */
2514 union xfs_btree_ptr *cpp; /* child ptr pointer */
2515 union xfs_btree_key *kp; /* pointer to btree key */
2516 union xfs_btree_ptr *pp; /* pointer to block addr */
2517 union xfs_btree_ptr nptr; /* new block addr */
2518 int level; /* btree level */
2519 int error; /* error return code */
2520#ifdef DEBUG
2521 int i; /* loop counter */
2522#endif
2523
2524 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2525 XFS_BTREE_STATS_INC(cur, newroot);
2526
2527 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
2528
2529 level = cur->bc_nlevels - 1;
2530
2531 block = xfs_btree_get_iroot(cur);
2532 pp = xfs_btree_ptr_addr(cur, 1, block);
2533
2534 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2535 error = cur->bc_ops->alloc_block(cur, pp, &nptr, 1, stat);
2536 if (error)
2537 goto error0;
2538 if (*stat == 0) {
2539 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2540 return 0;
2541 }
2542 XFS_BTREE_STATS_INC(cur, alloc);
2543
2544 /* Copy the root into a real block. */
2545 error = xfs_btree_get_buf_block(cur, &nptr, 0, &cblock, &cbp);
2546 if (error)
2547 goto error0;
2548
088c9f67
DC		 2549 /*
2550 * we can't just memcpy() the root in for CRC enabled btree blocks.
2551 * In that case have to also ensure the blkno remains correct
2552 */
ea77b0a6 2553 memcpy(cblock, block, xfs_btree_block_len(cur));
088c9f67
DC		 2554 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) {
2555 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
2556 cblock->bb_u.l.bb_blkno = cpu_to_be64(cbp->b_bn);
2557 else
2558 cblock->bb_u.s.bb_blkno = cpu_to_be64(cbp->b_bn);
2559 }
ea77b0a6
CH		 2560
2561 be16_add_cpu(&block->bb_level, 1);
2562 xfs_btree_set_numrecs(block, 1);
2563 cur->bc_nlevels++;
2564 cur->bc_ptrs[level + 1] = 1;
2565
2566 kp = xfs_btree_key_addr(cur, 1, block);
2567 ckp = xfs_btree_key_addr(cur, 1, cblock);
2568 xfs_btree_copy_keys(cur, ckp, kp, xfs_btree_get_numrecs(cblock));
2569
2570 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
2571#ifdef DEBUG
2572 for (i = 0; i < be16_to_cpu(cblock->bb_numrecs); i++) {
2573 error = xfs_btree_check_ptr(cur, pp, i, level);
2574 if (error)
2575 goto error0;
2576 }
2577#endif
2578 xfs_btree_copy_ptrs(cur, cpp, pp, xfs_btree_get_numrecs(cblock));
2579
2580#ifdef DEBUG
2581 error = xfs_btree_check_ptr(cur, &nptr, 0, level);
2582 if (error)
2583 goto error0;
2584#endif
2585 xfs_btree_copy_ptrs(cur, pp, &nptr, 1);
2586
2587 xfs_iroot_realloc(cur->bc_private.b.ip,
2588 1 - xfs_btree_get_numrecs(cblock),
2589 cur->bc_private.b.whichfork);
2590
2591 xfs_btree_setbuf(cur, level, cbp);
2592
2593 /*
2594 * Do all this logging at the end so that
2595 * the root is at the right level.
2596 */
2597 xfs_btree_log_block(cur, cbp, XFS_BB_ALL_BITS);
2598 xfs_btree_log_keys(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
2599 xfs_btree_log_ptrs(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
2600
2601 *logflags |=
9d87c319 2602 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork);
ea77b0a6
CH		 2603 *stat = 1;
2604 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2605 return 0;
2606error0:
2607 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2608 return error;
2609}
2610
344207ce
CH		 2611/*
2612 * Allocate a new root block, fill it in.
2613 */
3cc7524c 2614STATIC int /* error */
344207ce
CH		 2615xfs_btree_new_root(
2616 struct xfs_btree_cur *cur, /* btree cursor */
2617 int *stat) /* success/failure */
2618{
2619 struct xfs_btree_block *block; /* one half of the old root block */
2620 struct xfs_buf *bp; /* buffer containing block */
2621 int error; /* error return value */
2622 struct xfs_buf *lbp; /* left buffer pointer */
2623 struct xfs_btree_block *left; /* left btree block */
2624 struct xfs_buf *nbp; /* new (root) buffer */
2625 struct xfs_btree_block *new; /* new (root) btree block */
2626 int nptr; /* new value for key index, 1 or 2 */
2627 struct xfs_buf *rbp; /* right buffer pointer */
2628 struct xfs_btree_block *right; /* right btree block */
2629 union xfs_btree_ptr rptr;
2630 union xfs_btree_ptr lptr;
2631
2632 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2633 XFS_BTREE_STATS_INC(cur, newroot);
2634
2635 /* initialise our start point from the cursor */
2636 cur->bc_ops->init_ptr_from_cur(cur, &rptr);
2637
2638 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2639 error = cur->bc_ops->alloc_block(cur, &rptr, &lptr, 1, stat);
2640 if (error)
2641 goto error0;
2642 if (*stat == 0)
2643 goto out0;
2644 XFS_BTREE_STATS_INC(cur, alloc);
2645
2646 /* Set up the new block. */
2647 error = xfs_btree_get_buf_block(cur, &lptr, 0, &new, &nbp);
2648 if (error)
2649 goto error0;
2650
2651 /* Set the root in the holding structure increasing the level by 1. */
2652 cur->bc_ops->set_root(cur, &lptr, 1);
2653
2654 /*
2655 * At the previous root level there are now two blocks: the old root,
2656 * and the new block generated when it was split. We don't know which
2657 * one the cursor is pointing at, so we set up variables "left" and
2658 * "right" for each case.
2659 */
2660 block = xfs_btree_get_block(cur, cur->bc_nlevels - 1, &bp);
2661
2662#ifdef DEBUG
2663 error = xfs_btree_check_block(cur, block, cur->bc_nlevels - 1, bp);
2664 if (error)
2665 goto error0;
2666#endif
2667
2668 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
2669 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
2670 /* Our block is left, pick up the right block. */
2671 lbp = bp;
2672 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2673 left = block;
2674 error = xfs_btree_read_buf_block(cur, &rptr,
2675 cur->bc_nlevels - 1, 0, &right, &rbp);
2676 if (error)
2677 goto error0;
2678 bp = rbp;
2679 nptr = 1;
2680 } else {
2681 /* Our block is right, pick up the left block. */
2682 rbp = bp;
2683 xfs_btree_buf_to_ptr(cur, rbp, &rptr);
2684 right = block;
2685 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2686 error = xfs_btree_read_buf_block(cur, &lptr,
2687 cur->bc_nlevels - 1, 0, &left, &lbp);
2688 if (error)
2689 goto error0;
2690 bp = lbp;
2691 nptr = 2;
2692 }
2693 /* Fill in the new block's btree header and log it. */
ee1a47ab 2694 xfs_btree_init_block_cur(cur, nbp, cur->bc_nlevels, 2);
344207ce
CH		 2695 xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS);
2696 ASSERT(!xfs_btree_ptr_is_null(cur, &lptr) &&
2697 !xfs_btree_ptr_is_null(cur, &rptr));
2698
2699 /* Fill in the key data in the new root. */
2700 if (xfs_btree_get_level(left) > 0) {
2701 xfs_btree_copy_keys(cur,
2702 xfs_btree_key_addr(cur, 1, new),
2703 xfs_btree_key_addr(cur, 1, left), 1);
2704 xfs_btree_copy_keys(cur,
2705 xfs_btree_key_addr(cur, 2, new),
2706 xfs_btree_key_addr(cur, 1, right), 1);
2707 } else {
2708 cur->bc_ops->init_key_from_rec(
2709 xfs_btree_key_addr(cur, 1, new),
2710 xfs_btree_rec_addr(cur, 1, left));
2711 cur->bc_ops->init_key_from_rec(
2712 xfs_btree_key_addr(cur, 2, new),
2713 xfs_btree_rec_addr(cur, 1, right));
2714 }
2715 xfs_btree_log_keys(cur, nbp, 1, 2);
2716
2717 /* Fill in the pointer data in the new root. */
2718 xfs_btree_copy_ptrs(cur,
2719 xfs_btree_ptr_addr(cur, 1, new), &lptr, 1);
2720 xfs_btree_copy_ptrs(cur,
2721 xfs_btree_ptr_addr(cur, 2, new), &rptr, 1);
2722 xfs_btree_log_ptrs(cur, nbp, 1, 2);
2723
2724 /* Fix up the cursor. */
2725 xfs_btree_setbuf(cur, cur->bc_nlevels, nbp);
2726 cur->bc_ptrs[cur->bc_nlevels] = nptr;
2727 cur->bc_nlevels++;
2728 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2729 *stat = 1;
2730 return 0;
2731error0:
2732 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2733 return error;
2734out0:
2735 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2736 *stat = 0;
2737 return 0;
2738}
4b22a571
CH		 2739
2740STATIC int
2741xfs_btree_make_block_unfull(
2742 struct xfs_btree_cur *cur, /* btree cursor */
2743 int level, /* btree level */
2744 int numrecs,/* # of recs in block */
2745 int *oindex,/* old tree index */
2746 int *index, /* new tree index */
2747 union xfs_btree_ptr *nptr, /* new btree ptr */
2748 struct xfs_btree_cur **ncur, /* new btree cursor */
2749 union xfs_btree_rec *nrec, /* new record */
2750 int *stat)
2751{
2752 union xfs_btree_key key; /* new btree key value */
2753 int error = 0;
2754
2755 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2756 level == cur->bc_nlevels - 1) {
2757 struct xfs_inode *ip = cur->bc_private.b.ip;
2758
2759 if (numrecs < cur->bc_ops->get_dmaxrecs(cur, level)) {
2760 /* A root block that can be made bigger. */
4b22a571
CH		 2761 xfs_iroot_realloc(ip, 1, cur->bc_private.b.whichfork);
2762 } else {
2763 /* A root block that needs replacing */
2764 int logflags = 0;
2765
2766 error = xfs_btree_new_iroot(cur, &logflags, stat);
2767 if (error || *stat == 0)
2768 return error;
2769
2770 xfs_trans_log_inode(cur->bc_tp, ip, logflags);
2771 }
2772
2773 return 0;
2774 }
2775
2776 /* First, try shifting an entry to the right neighbor. */
2777 error = xfs_btree_rshift(cur, level, stat);
2778 if (error || *stat)
2779 return error;
2780
2781 /* Next, try shifting an entry to the left neighbor. */
2782 error = xfs_btree_lshift(cur, level, stat);
2783 if (error)
2784 return error;
2785
2786 if (*stat) {
2787 *oindex = *index = cur->bc_ptrs[level];
2788 return 0;
2789 }
2790
2791 /*
2792 * Next, try splitting the current block in half.
2793 *
2794 * If this works we have to re-set our variables because we
2795 * could be in a different block now.
2796 */
2797 error = xfs_btree_split(cur, level, nptr, &key, ncur, stat);
2798 if (error || *stat == 0)
2799 return error;
2800
2801
2802 *index = cur->bc_ptrs[level];
2803 cur->bc_ops->init_rec_from_key(&key, nrec);
2804 return 0;
2805}
2806
2807/*
2808 * Insert one record/level. Return information to the caller
2809 * allowing the next level up to proceed if necessary.
2810 */
2811STATIC int
2812xfs_btree_insrec(
2813 struct xfs_btree_cur *cur, /* btree cursor */
2814 int level, /* level to insert record at */
2815 union xfs_btree_ptr *ptrp, /* i/o: block number inserted */
2816 union xfs_btree_rec *recp, /* i/o: record data inserted */
2817 struct xfs_btree_cur **curp, /* output: new cursor replacing cur */
2818 int *stat) /* success/failure */
2819{
2820 struct xfs_btree_block *block; /* btree block */
2821 struct xfs_buf *bp; /* buffer for block */
2822 union xfs_btree_key key; /* btree key */
2823 union xfs_btree_ptr nptr; /* new block ptr */
2824 struct xfs_btree_cur *ncur; /* new btree cursor */
2825 union xfs_btree_rec nrec; /* new record count */
2826 int optr; /* old key/record index */
2827 int ptr; /* key/record index */
2828 int numrecs;/* number of records */
2829 int error; /* error return value */
2830#ifdef DEBUG
2831 int i;
2832#endif
2833
2834 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2835 XFS_BTREE_TRACE_ARGIPR(cur, level, *ptrp, recp);
2836
2837 ncur = NULL;
2838
2839 /*
2840 * If we have an external root pointer, and we've made it to the
2841 * root level, allocate a new root block and we're done.
2842 */
2843 if (!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2844 (level >= cur->bc_nlevels)) {
2845 error = xfs_btree_new_root(cur, stat);
2846 xfs_btree_set_ptr_null(cur, ptrp);
2847
2848 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2849 return error;
2850 }
2851
2852 /* If we're off the left edge, return failure. */
2853 ptr = cur->bc_ptrs[level];
2854 if (ptr == 0) {
2855 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2856 *stat = 0;
2857 return 0;
2858 }
2859
2860 /* Make a key out of the record data to be inserted, and save it. */
2861 cur->bc_ops->init_key_from_rec(&key, recp);
2862
2863 optr = ptr;
2864
2865 XFS_BTREE_STATS_INC(cur, insrec);
2866
2867 /* Get pointers to the btree buffer and block. */
2868 block = xfs_btree_get_block(cur, level, &bp);
2869 numrecs = xfs_btree_get_numrecs(block);
2870
2871#ifdef DEBUG
2872 error = xfs_btree_check_block(cur, block, level, bp);
2873 if (error)
2874 goto error0;
2875
2876 /* Check that the new entry is being inserted in the right place. */
2877 if (ptr <= numrecs) {
2878 if (level == 0) {
4a26e66e
CH		 2879 ASSERT(cur->bc_ops->recs_inorder(cur, recp,
2880 xfs_btree_rec_addr(cur, ptr, block)));
4b22a571 2881 } else {
4a26e66e
CH		 2882 ASSERT(cur->bc_ops->keys_inorder(cur, &key,
2883 xfs_btree_key_addr(cur, ptr, block)));
4b22a571
CH		 2884 }
2885 }
2886#endif
2887
2888 /*
2889 * If the block is full, we can't insert the new entry until we
2890 * make the block un-full.
2891 */
2892 xfs_btree_set_ptr_null(cur, &nptr);
2893 if (numrecs == cur->bc_ops->get_maxrecs(cur, level)) {
2894 error = xfs_btree_make_block_unfull(cur, level, numrecs,
2895 &optr, &ptr, &nptr, &ncur, &nrec, stat);
2896 if (error || *stat == 0)
2897 goto error0;
2898 }
2899
2900 /*
2901 * The current block may have changed if the block was
2902 * previously full and we have just made space in it.
2903 */
2904 block = xfs_btree_get_block(cur, level, &bp);
2905 numrecs = xfs_btree_get_numrecs(block);
2906
2907#ifdef DEBUG
2908 error = xfs_btree_check_block(cur, block, level, bp);
2909 if (error)
2910 return error;
2911#endif
2912
2913 /*
2914 * At this point we know there's room for our new entry in the block
2915 * we're pointing at.
2916 */
2917 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr + 1);
2918
2919 if (level > 0) {
2920 /* It's a nonleaf. make a hole in the keys and ptrs */
2921 union xfs_btree_key *kp;
2922 union xfs_btree_ptr *pp;
2923
2924 kp = xfs_btree_key_addr(cur, ptr, block);
2925 pp = xfs_btree_ptr_addr(cur, ptr, block);
2926
2927#ifdef DEBUG
2928 for (i = numrecs - ptr; i >= 0; i--) {
2929 error = xfs_btree_check_ptr(cur, pp, i, level);
2930 if (error)
2931 return error;
2932 }
2933#endif
2934
2935 xfs_btree_shift_keys(cur, kp, 1, numrecs - ptr + 1);
2936 xfs_btree_shift_ptrs(cur, pp, 1, numrecs - ptr + 1);
2937
2938#ifdef DEBUG
2939 error = xfs_btree_check_ptr(cur, ptrp, 0, level);
2940 if (error)
2941 goto error0;
2942#endif
2943
2944 /* Now put the new data in, bump numrecs and log it. */
2945 xfs_btree_copy_keys(cur, kp, &key, 1);
2946 xfs_btree_copy_ptrs(cur, pp, ptrp, 1);
2947 numrecs++;
2948 xfs_btree_set_numrecs(block, numrecs);
2949 xfs_btree_log_ptrs(cur, bp, ptr, numrecs);
2950 xfs_btree_log_keys(cur, bp, ptr, numrecs);
2951#ifdef DEBUG
2952 if (ptr < numrecs) {
4a26e66e
CH		 2953 ASSERT(cur->bc_ops->keys_inorder(cur, kp,
2954 xfs_btree_key_addr(cur, ptr + 1, block)));
4b22a571
CH		 2955 }
2956#endif
2957 } else {
2958 /* It's a leaf. make a hole in the records */
2959 union xfs_btree_rec *rp;
2960
2961 rp = xfs_btree_rec_addr(cur, ptr, block);
2962
2963 xfs_btree_shift_recs(cur, rp, 1, numrecs - ptr + 1);
2964
2965 /* Now put the new data in, bump numrecs and log it. */
2966 xfs_btree_copy_recs(cur, rp, recp, 1);
2967 xfs_btree_set_numrecs(block, ++numrecs);
2968 xfs_btree_log_recs(cur, bp, ptr, numrecs);
2969#ifdef DEBUG
2970 if (ptr < numrecs) {
4a26e66e
CH		 2971 ASSERT(cur->bc_ops->recs_inorder(cur, rp,
2972 xfs_btree_rec_addr(cur, ptr + 1, block)));
4b22a571
CH		 2973 }
2974#endif
2975 }
2976
2977 /* Log the new number of records in the btree header. */
2978 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
2979
2980 /* If we inserted at the start of a block, update the parents' keys. */
2981 if (optr == 1) {
2982 error = xfs_btree_updkey(cur, &key, level + 1);
2983 if (error)
2984 goto error0;
2985 }
2986
2987 /*
2988 * If we are tracking the last record in the tree and
2989 * we are at the far right edge of the tree, update it.
2990 */
2991 if (xfs_btree_is_lastrec(cur, block, level)) {
2992 cur->bc_ops->update_lastrec(cur, block, recp,
2993 ptr, LASTREC_INSREC);
2994 }
2995
2996 /*
2997 * Return the new block number, if any.
2998 * If there is one, give back a record value and a cursor too.
2999 */
3000 *ptrp = nptr;
3001 if (!xfs_btree_ptr_is_null(cur, &nptr)) {
3002 *recp = nrec;
3003 *curp = ncur;
3004 }
3005
3006 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3007 *stat = 1;
3008 return 0;
3009
3010error0:
3011 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3012 return error;
3013}
3014
3015/*
3016 * Insert the record at the point referenced by cur.
3017 *
3018 * A multi-level split of the tree on insert will invalidate the original
3019 * cursor. All callers of this function should assume that the cursor is
3020 * no longer valid and revalidate it.
3021 */
3022int
3023xfs_btree_insert(
3024 struct xfs_btree_cur *cur,
3025 int *stat)
3026{
3027 int error; /* error return value */
3028 int i; /* result value, 0 for failure */
3029 int level; /* current level number in btree */
3030 union xfs_btree_ptr nptr; /* new block number (split result) */
3031 struct xfs_btree_cur *ncur; /* new cursor (split result) */
3032 struct xfs_btree_cur *pcur; /* previous level's cursor */
3033 union xfs_btree_rec rec; /* record to insert */
3034
3035 level = 0;
3036 ncur = NULL;
3037 pcur = cur;
3038
3039 xfs_btree_set_ptr_null(cur, &nptr);
3040 cur->bc_ops->init_rec_from_cur(cur, &rec);
3041
3042 /*
3043 * Loop going up the tree, starting at the leaf level.
3044 * Stop when we don't get a split block, that must mean that
3045 * the insert is finished with this level.
3046 */
3047 do {
3048 /*
3049 * Insert nrec/nptr into this level of the tree.
3050 * Note if we fail, nptr will be null.
3051 */
3052 error = xfs_btree_insrec(pcur, level, &nptr, &rec, &ncur, &i);
3053 if (error) {
3054 if (pcur != cur)
3055 xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR);
3056 goto error0;
3057 }
3058
3059 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3060 level++;
3061
3062 /*
3063 * See if the cursor we just used is trash.
3064 * Can't trash the caller's cursor, but otherwise we should
3065 * if ncur is a new cursor or we're about to be done.
3066 */
3067 if (pcur != cur &&
3068 (ncur || xfs_btree_ptr_is_null(cur, &nptr))) {
3069 /* Save the state from the cursor before we trash it */
3070 if (cur->bc_ops->update_cursor)
3071 cur->bc_ops->update_cursor(pcur, cur);
3072 cur->bc_nlevels = pcur->bc_nlevels;
3073 xfs_btree_del_cursor(pcur, XFS_BTREE_NOERROR);
3074 }
3075 /* If we got a new cursor, switch to it. */
3076 if (ncur) {
3077 pcur = ncur;
3078 ncur = NULL;
3079 }
3080 } while (!xfs_btree_ptr_is_null(cur, &nptr));
3081
3082 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3083 *stat = i;
3084 return 0;
3085error0:
3086 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3087 return error;
3088}
d4b3a4b7
CH		 3089
3090/*
3091 * Try to merge a non-leaf block back into the inode root.
3092 *
3093 * Note: the killroot names comes from the fact that we're effectively
3094 * killing the old root block. But because we can't just delete the
3095 * inode we have to copy the single block it was pointing to into the
3096 * inode.
3097 */
d96f8f89 3098STATIC int
d4b3a4b7
CH		 3099xfs_btree_kill_iroot(
3100 struct xfs_btree_cur *cur)
3101{
3102 int whichfork = cur->bc_private.b.whichfork;
3103 struct xfs_inode *ip = cur->bc_private.b.ip;
3104 struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork);
3105 struct xfs_btree_block *block;
3106 struct xfs_btree_block *cblock;
3107 union xfs_btree_key *kp;
3108 union xfs_btree_key *ckp;
3109 union xfs_btree_ptr *pp;
3110 union xfs_btree_ptr *cpp;
3111 struct xfs_buf *cbp;
3112 int level;
3113 int index;
3114 int numrecs;
3115#ifdef DEBUG
3116 union xfs_btree_ptr ptr;
3117 int i;
3118#endif
3119
3120 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3121
3122 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
3123 ASSERT(cur->bc_nlevels > 1);
3124
3125 /*
3126 * Don't deal with the root block needs to be a leaf case.
3127 * We're just going to turn the thing back into extents anyway.
3128 */
3129 level = cur->bc_nlevels - 1;
3130 if (level == 1)
3131 goto out0;
3132
3133 /*
3134 * Give up if the root has multiple children.
3135 */
3136 block = xfs_btree_get_iroot(cur);
3137 if (xfs_btree_get_numrecs(block) != 1)
3138 goto out0;
3139
3140 cblock = xfs_btree_get_block(cur, level - 1, &cbp);
3141 numrecs = xfs_btree_get_numrecs(cblock);
3142
3143 /*
3144 * Only do this if the next level will fit.
3145 * Then the data must be copied up to the inode,
3146 * instead of freeing the root you free the next level.
3147 */
3148 if (numrecs > cur->bc_ops->get_dmaxrecs(cur, level))
3149 goto out0;
3150
3151 XFS_BTREE_STATS_INC(cur, killroot);
3152
3153#ifdef DEBUG
3154 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
3155 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
3156 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
3157 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
3158#endif
3159
3160 index = numrecs - cur->bc_ops->get_maxrecs(cur, level);
3161 if (index) {
3162 xfs_iroot_realloc(cur->bc_private.b.ip, index,
3163 cur->bc_private.b.whichfork);
7cc95a82 3164 block = ifp->if_broot;
d4b3a4b7
CH		 3165 }
3166
3167 be16_add_cpu(&block->bb_numrecs, index);
3168 ASSERT(block->bb_numrecs == cblock->bb_numrecs);
3169
3170 kp = xfs_btree_key_addr(cur, 1, block);
3171 ckp = xfs_btree_key_addr(cur, 1, cblock);
3172 xfs_btree_copy_keys(cur, kp, ckp, numrecs);
3173
3174 pp = xfs_btree_ptr_addr(cur, 1, block);
3175 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
3176#ifdef DEBUG
3177 for (i = 0; i < numrecs; i++) {
3178 int error;
3179
3180 error = xfs_btree_check_ptr(cur, cpp, i, level - 1);
3181 if (error) {
3182 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3183 return error;
3184 }
3185 }
3186#endif
3187 xfs_btree_copy_ptrs(cur, pp, cpp, numrecs);
3188
3189 cur->bc_ops->free_block(cur, cbp);
3190 XFS_BTREE_STATS_INC(cur, free);
3191
3192 cur->bc_bufs[level - 1] = NULL;
3193 be16_add_cpu(&block->bb_level, -1);
3194 xfs_trans_log_inode(cur->bc_tp, ip,
9d87c319 3195 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork));
d4b3a4b7
CH		 3196 cur->bc_nlevels--;
3197out0:
3198 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3199 return 0;
3200}
91cca5df 3201
c0e59e1a
CH		 3202/*
3203 * Kill the current root node, and replace it with it's only child node.
3204 */
3205STATIC int
3206xfs_btree_kill_root(
3207 struct xfs_btree_cur *cur,
3208 struct xfs_buf *bp,
3209 int level,
3210 union xfs_btree_ptr *newroot)
3211{
3212 int error;
3213
3214 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3215 XFS_BTREE_STATS_INC(cur, killroot);
3216
3217 /*
3218 * Update the root pointer, decreasing the level by 1 and then
3219 * free the old root.
3220 */
3221 cur->bc_ops->set_root(cur, newroot, -1);
3222
3223 error = cur->bc_ops->free_block(cur, bp);
3224 if (error) {
3225 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3226 return error;
3227 }
3228
3229 XFS_BTREE_STATS_INC(cur, free);
3230
3231 cur->bc_bufs[level] = NULL;
3232 cur->bc_ra[level] = 0;
3233 cur->bc_nlevels--;
3234
3235 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3236 return 0;
3237}
3238
91cca5df
CH		 3239STATIC int
3240xfs_btree_dec_cursor(
3241 struct xfs_btree_cur *cur,
3242 int level,
3243 int *stat)
3244{
3245 int error;
3246 int i;
3247
3248 if (level > 0) {
3249 error = xfs_btree_decrement(cur, level, &i);
3250 if (error)
3251 return error;
3252 }
3253
3254 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3255 *stat = 1;
3256 return 0;
3257}
3258
3259/*
3260 * Single level of the btree record deletion routine.
3261 * Delete record pointed to by cur/level.
3262 * Remove the record from its block then rebalance the tree.
3263 * Return 0 for error, 1 for done, 2 to go on to the next level.
3264 */
3265STATIC int /* error */
3266xfs_btree_delrec(
3267 struct xfs_btree_cur *cur, /* btree cursor */
3268 int level, /* level removing record from */
3269 int *stat) /* fail/done/go-on */
3270{
3271 struct xfs_btree_block *block; /* btree block */
3272 union xfs_btree_ptr cptr; /* current block ptr */
3273 struct xfs_buf *bp; /* buffer for block */
3274 int error; /* error return value */
3275 int i; /* loop counter */
3276 union xfs_btree_key key; /* storage for keyp */
3277 union xfs_btree_key *keyp = &key; /* passed to the next level */
3278 union xfs_btree_ptr lptr; /* left sibling block ptr */
3279 struct xfs_buf *lbp; /* left buffer pointer */
3280 struct xfs_btree_block *left; /* left btree block */
3281 int lrecs = 0; /* left record count */
3282 int ptr; /* key/record index */
3283 union xfs_btree_ptr rptr; /* right sibling block ptr */
3284 struct xfs_buf *rbp; /* right buffer pointer */
3285 struct xfs_btree_block *right; /* right btree block */
3286 struct xfs_btree_block *rrblock; /* right-right btree block */
3287 struct xfs_buf *rrbp; /* right-right buffer pointer */
3288 int rrecs = 0; /* right record count */
3289 struct xfs_btree_cur *tcur; /* temporary btree cursor */
3290 int numrecs; /* temporary numrec count */
3291
3292 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3293 XFS_BTREE_TRACE_ARGI(cur, level);
3294
3295 tcur = NULL;
3296
3297 /* Get the index of the entry being deleted, check for nothing there. */
3298 ptr = cur->bc_ptrs[level];
3299 if (ptr == 0) {
3300 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3301 *stat = 0;
3302 return 0;
3303 }
3304
3305 /* Get the buffer & block containing the record or key/ptr. */
3306 block = xfs_btree_get_block(cur, level, &bp);
3307 numrecs = xfs_btree_get_numrecs(block);
3308
3309#ifdef DEBUG
3310 error = xfs_btree_check_block(cur, block, level, bp);
3311 if (error)
3312 goto error0;
3313#endif
3314
3315 /* Fail if we're off the end of the block. */
3316 if (ptr > numrecs) {
3317 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3318 *stat = 0;
3319 return 0;
3320 }
3321
3322 XFS_BTREE_STATS_INC(cur, delrec);
3323 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr);
3324
3325 /* Excise the entries being deleted. */
3326 if (level > 0) {
3327 /* It's a nonleaf. operate on keys and ptrs */
3328 union xfs_btree_key *lkp;
3329 union xfs_btree_ptr *lpp;
3330
3331 lkp = xfs_btree_key_addr(cur, ptr + 1, block);
3332 lpp = xfs_btree_ptr_addr(cur, ptr + 1, block);
3333
3334#ifdef DEBUG
3335 for (i = 0; i < numrecs - ptr; i++) {
3336 error = xfs_btree_check_ptr(cur, lpp, i, level);
3337 if (error)
3338 goto error0;
3339 }
3340#endif
3341
3342 if (ptr < numrecs) {
3343 xfs_btree_shift_keys(cur, lkp, -1, numrecs - ptr);
3344 xfs_btree_shift_ptrs(cur, lpp, -1, numrecs - ptr);
3345 xfs_btree_log_keys(cur, bp, ptr, numrecs - 1);
3346 xfs_btree_log_ptrs(cur, bp, ptr, numrecs - 1);
3347 }
3348
3349 /*
3350 * If it's the first record in the block, we'll need to pass a
3351 * key up to the next level (updkey).
3352 */
3353 if (ptr == 1)
3354 keyp = xfs_btree_key_addr(cur, 1, block);
3355 } else {
3356 /* It's a leaf. operate on records */
3357 if (ptr < numrecs) {
3358 xfs_btree_shift_recs(cur,
3359 xfs_btree_rec_addr(cur, ptr + 1, block),
3360 -1, numrecs - ptr);
3361 xfs_btree_log_recs(cur, bp, ptr, numrecs - 1);
3362 }
3363
3364 /*
3365 * If it's the first record in the block, we'll need a key
3366 * structure to pass up to the next level (updkey).
3367 */
3368 if (ptr == 1) {
3369 cur->bc_ops->init_key_from_rec(&key,
3370 xfs_btree_rec_addr(cur, 1, block));
3371 keyp = &key;
3372 }
3373 }
3374
3375 /*
3376 * Decrement and log the number of entries in the block.
3377 */
3378 xfs_btree_set_numrecs(block, --numrecs);
3379 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
3380
3381 /*
3382 * If we are tracking the last record in the tree and
3383 * we are at the far right edge of the tree, update it.
3384 */
3385 if (xfs_btree_is_lastrec(cur, block, level)) {
3386 cur->bc_ops->update_lastrec(cur, block, NULL,
3387 ptr, LASTREC_DELREC);
3388 }
3389
3390 /*
3391 * We're at the root level. First, shrink the root block in-memory.
3392 * Try to get rid of the next level down. If we can't then there's
3393 * nothing left to do.
3394 */
3395 if (level == cur->bc_nlevels - 1) {
3396 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3397 xfs_iroot_realloc(cur->bc_private.b.ip, -1,
3398 cur->bc_private.b.whichfork);
3399
3400 error = xfs_btree_kill_iroot(cur);
3401 if (error)
3402 goto error0;
3403
3404 error = xfs_btree_dec_cursor(cur, level, stat);
3405 if (error)
3406 goto error0;
3407 *stat = 1;
3408 return 0;
3409 }
3410
3411 /*
3412 * If this is the root level, and there's only one entry left,
3413 * and it's NOT the leaf level, then we can get rid of this
3414 * level.
3415 */
3416 if (numrecs == 1 && level > 0) {
3417 union xfs_btree_ptr *pp;
3418 /*
3419 * pp is still set to the first pointer in the block.
3420 * Make it the new root of the btree.
3421 */
3422 pp = xfs_btree_ptr_addr(cur, 1, block);
c0e59e1a 3423 error = xfs_btree_kill_root(cur, bp, level, pp);
91cca5df
CH		 3424 if (error)
3425 goto error0;
3426 } else if (level > 0) {
3427 error = xfs_btree_dec_cursor(cur, level, stat);
3428 if (error)
3429 goto error0;
3430 }
3431 *stat = 1;
3432 return 0;
3433 }
3434
3435 /*
3436 * If we deleted the leftmost entry in the block, update the
3437 * key values above us in the tree.
3438 */
3439 if (ptr == 1) {
3440 error = xfs_btree_updkey(cur, keyp, level + 1);
3441 if (error)
3442 goto error0;
3443 }
3444
3445 /*
3446 * If the number of records remaining in the block is at least
3447 * the minimum, we're done.
3448 */
3449 if (numrecs >= cur->bc_ops->get_minrecs(cur, level)) {
3450 error = xfs_btree_dec_cursor(cur, level, stat);
3451 if (error)
3452 goto error0;
3453 return 0;
3454 }
3455
3456 /*
3457 * Otherwise, we have to move some records around to keep the
3458 * tree balanced. Look at the left and right sibling blocks to
3459 * see if we can re-balance by moving only one record.
3460 */
3461 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
3462 xfs_btree_get_sibling(cur, block, &lptr, XFS_BB_LEFTSIB);
3463
3464 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3465 /*
3466 * One child of root, need to get a chance to copy its contents
3467 * into the root and delete it. Can't go up to next level,
3468 * there's nothing to delete there.
3469 */
3470 if (xfs_btree_ptr_is_null(cur, &rptr) &&
3471 xfs_btree_ptr_is_null(cur, &lptr) &&
3472 level == cur->bc_nlevels - 2) {
3473 error = xfs_btree_kill_iroot(cur);
3474 if (!error)
3475 error = xfs_btree_dec_cursor(cur, level, stat);
3476 if (error)
3477 goto error0;
3478 return 0;
3479 }
3480 }
3481
3482 ASSERT(!xfs_btree_ptr_is_null(cur, &rptr) ||
3483 !xfs_btree_ptr_is_null(cur, &lptr));
3484
3485 /*
3486 * Duplicate the cursor so our btree manipulations here won't
3487 * disrupt the next level up.
3488 */
3489 error = xfs_btree_dup_cursor(cur, &tcur);
3490 if (error)
3491 goto error0;
3492
3493 /*
3494 * If there's a right sibling, see if it's ok to shift an entry
3495 * out of it.
3496 */
3497 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
3498 /*
3499 * Move the temp cursor to the last entry in the next block.
3500 * Actually any entry but the first would suffice.
3501 */
3502 i = xfs_btree_lastrec(tcur, level);
3503 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3504
3505 error = xfs_btree_increment(tcur, level, &i);
3506 if (error)
3507 goto error0;
3508 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3509
3510 i = xfs_btree_lastrec(tcur, level);
3511 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3512
3513 /* Grab a pointer to the block. */
3514 right = xfs_btree_get_block(tcur, level, &rbp);
3515#ifdef DEBUG
3516 error = xfs_btree_check_block(tcur, right, level, rbp);
3517 if (error)
3518 goto error0;
3519#endif
3520 /* Grab the current block number, for future use. */
3521 xfs_btree_get_sibling(tcur, right, &cptr, XFS_BB_LEFTSIB);
3522
3523 /*
3524 * If right block is full enough so that removing one entry
3525 * won't make it too empty, and left-shifting an entry out
3526 * of right to us works, we're done.
3527 */
3528 if (xfs_btree_get_numrecs(right) - 1 >=
3529 cur->bc_ops->get_minrecs(tcur, level)) {
3530 error = xfs_btree_lshift(tcur, level, &i);
3531 if (error)
3532 goto error0;
3533 if (i) {
3534 ASSERT(xfs_btree_get_numrecs(block) >=
3535 cur->bc_ops->get_minrecs(tcur, level));
3536
3537 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3538 tcur = NULL;
3539
3540 error = xfs_btree_dec_cursor(cur, level, stat);
3541 if (error)
3542 goto error0;
3543 return 0;
3544 }
3545 }
3546
3547 /*
3548 * Otherwise, grab the number of records in right for
3549 * future reference, and fix up the temp cursor to point
3550 * to our block again (last record).
3551 */
3552 rrecs = xfs_btree_get_numrecs(right);
3553 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3554 i = xfs_btree_firstrec(tcur, level);
3555 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3556
3557 error = xfs_btree_decrement(tcur, level, &i);
3558 if (error)
3559 goto error0;
3560 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3561 }
3562 }
3563
3564 /*
3565 * If there's a left sibling, see if it's ok to shift an entry
3566 * out of it.
3567 */
3568 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3569 /*
3570 * Move the temp cursor to the first entry in the
3571 * previous block.
3572 */
3573 i = xfs_btree_firstrec(tcur, level);
3574 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3575
3576 error = xfs_btree_decrement(tcur, level, &i);
3577 if (error)
3578 goto error0;
3579 i = xfs_btree_firstrec(tcur, level);
3580 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3581
3582 /* Grab a pointer to the block. */
3583 left = xfs_btree_get_block(tcur, level, &lbp);
3584#ifdef DEBUG
3585 error = xfs_btree_check_block(cur, left, level, lbp);
3586 if (error)
3587 goto error0;
3588#endif
3589 /* Grab the current block number, for future use. */
3590 xfs_btree_get_sibling(tcur, left, &cptr, XFS_BB_RIGHTSIB);
3591
3592 /*
3593 * If left block is full enough so that removing one entry
3594 * won't make it too empty, and right-shifting an entry out
3595 * of left to us works, we're done.
3596 */
3597 if (xfs_btree_get_numrecs(left) - 1 >=
3598 cur->bc_ops->get_minrecs(tcur, level)) {
3599 error = xfs_btree_rshift(tcur, level, &i);
3600 if (error)
3601 goto error0;
3602 if (i) {
3603 ASSERT(xfs_btree_get_numrecs(block) >=
3604 cur->bc_ops->get_minrecs(tcur, level));
3605 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3606 tcur = NULL;
3607 if (level == 0)
3608 cur->bc_ptrs[0]++;
3609 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3610 *stat = 1;
3611 return 0;
3612 }
3613 }
3614
3615 /*
3616 * Otherwise, grab the number of records in right for
3617 * future reference.
3618 */
3619 lrecs = xfs_btree_get_numrecs(left);
3620 }
3621
3622 /* Delete the temp cursor, we're done with it. */
3623 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3624 tcur = NULL;
3625
3626 /* If here, we need to do a join to keep the tree balanced. */
3627 ASSERT(!xfs_btree_ptr_is_null(cur, &cptr));
3628
3629 if (!xfs_btree_ptr_is_null(cur, &lptr) &&
3630 lrecs + xfs_btree_get_numrecs(block) <=
3631 cur->bc_ops->get_maxrecs(cur, level)) {
3632 /*
3633 * Set "right" to be the starting block,
3634 * "left" to be the left neighbor.
3635 */
3636 rptr = cptr;
3637 right = block;
3638 rbp = bp;
3639 error = xfs_btree_read_buf_block(cur, &lptr, level,
3640 0, &left, &lbp);
3641 if (error)
3642 goto error0;
3643
3644 /*
3645 * If that won't work, see if we can join with the right neighbor block.
3646 */
3647 } else if (!xfs_btree_ptr_is_null(cur, &rptr) &&
3648 rrecs + xfs_btree_get_numrecs(block) <=
3649 cur->bc_ops->get_maxrecs(cur, level)) {
3650 /*
3651 * Set "left" to be the starting block,
3652 * "right" to be the right neighbor.
3653 */
3654 lptr = cptr;
3655 left = block;
3656 lbp = bp;
3657 error = xfs_btree_read_buf_block(cur, &rptr, level,
3658 0, &right, &rbp);
3659 if (error)
3660 goto error0;
3661
3662 /*
3663 * Otherwise, we can't fix the imbalance.
3664 * Just return. This is probably a logic error, but it's not fatal.
3665 */
3666 } else {
3667 error = xfs_btree_dec_cursor(cur, level, stat);
3668 if (error)
3669 goto error0;
3670 return 0;
3671 }
3672
3673 rrecs = xfs_btree_get_numrecs(right);
3674 lrecs = xfs_btree_get_numrecs(left);
3675
3676 /*
3677 * We're now going to join "left" and "right" by moving all the stuff
3678 * in "right" to "left" and deleting "right".
3679 */
3680 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
3681 if (level > 0) {
3682 /* It's a non-leaf. Move keys and pointers. */
3683 union xfs_btree_key *lkp; /* left btree key */
3684 union xfs_btree_ptr *lpp; /* left address pointer */
3685 union xfs_btree_key *rkp; /* right btree key */
3686 union xfs_btree_ptr *rpp; /* right address pointer */
3687
3688 lkp = xfs_btree_key_addr(cur, lrecs + 1, left);
3689 lpp = xfs_btree_ptr_addr(cur, lrecs + 1, left);
3690 rkp = xfs_btree_key_addr(cur, 1, right);
3691 rpp = xfs_btree_ptr_addr(cur, 1, right);
3692#ifdef DEBUG
3693 for (i = 1; i < rrecs; i++) {
3694 error = xfs_btree_check_ptr(cur, rpp, i, level);
3695 if (error)
3696 goto error0;
3697 }
3698#endif
3699 xfs_btree_copy_keys(cur, lkp, rkp, rrecs);
3700 xfs_btree_copy_ptrs(cur, lpp, rpp, rrecs);
3701
3702 xfs_btree_log_keys(cur, lbp, lrecs + 1, lrecs + rrecs);
3703 xfs_btree_log_ptrs(cur, lbp, lrecs + 1, lrecs + rrecs);
3704 } else {
3705 /* It's a leaf. Move records. */
3706 union xfs_btree_rec *lrp; /* left record pointer */
3707 union xfs_btree_rec *rrp; /* right record pointer */
3708
3709 lrp = xfs_btree_rec_addr(cur, lrecs + 1, left);
3710 rrp = xfs_btree_rec_addr(cur, 1, right);
3711
3712 xfs_btree_copy_recs(cur, lrp, rrp, rrecs);
3713 xfs_btree_log_recs(cur, lbp, lrecs + 1, lrecs + rrecs);
3714 }
3715
3716 XFS_BTREE_STATS_INC(cur, join);
3717
3718 /*
9da096fd 3719 * Fix up the number of records and right block pointer in the
91cca5df
CH		 3720 * surviving block, and log it.
3721 */
3722 xfs_btree_set_numrecs(left, lrecs + rrecs);
3723 xfs_btree_get_sibling(cur, right, &cptr, XFS_BB_RIGHTSIB),
3724 xfs_btree_set_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
3725 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
3726
3727 /* If there is a right sibling, point it to the remaining block. */
3728 xfs_btree_get_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
3729 if (!xfs_btree_ptr_is_null(cur, &cptr)) {
3730 error = xfs_btree_read_buf_block(cur, &cptr, level,
3731 0, &rrblock, &rrbp);
3732 if (error)
3733 goto error0;
3734 xfs_btree_set_sibling(cur, rrblock, &lptr, XFS_BB_LEFTSIB);
3735 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
3736 }
3737
3738 /* Free the deleted block. */
3739 error = cur->bc_ops->free_block(cur, rbp);
3740 if (error)
3741 goto error0;
3742 XFS_BTREE_STATS_INC(cur, free);
3743
3744 /*
3745 * If we joined with the left neighbor, set the buffer in the
3746 * cursor to the left block, and fix up the index.
3747 */
3748 if (bp != lbp) {
3749 cur->bc_bufs[level] = lbp;
3750 cur->bc_ptrs[level] += lrecs;
3751 cur->bc_ra[level] = 0;
3752 }
3753 /*
3754 * If we joined with the right neighbor and there's a level above
3755 * us, increment the cursor at that level.
3756 */
3757 else if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) ||
3758 (level + 1 < cur->bc_nlevels)) {
3759 error = xfs_btree_increment(cur, level + 1, &i);
3760 if (error)
3761 goto error0;
3762 }
3763
3764 /*
3765 * Readjust the ptr at this level if it's not a leaf, since it's
3766 * still pointing at the deletion point, which makes the cursor
3767 * inconsistent. If this makes the ptr 0, the caller fixes it up.
3768 * We can't use decrement because it would change the next level up.
3769 */
3770 if (level > 0)
3771 cur->bc_ptrs[level]--;
3772
3773 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3774 /* Return value means the next level up has something to do. */
3775 *stat = 2;
3776 return 0;
3777
3778error0:
3779 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3780 if (tcur)
3781 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
3782 return error;
3783}
3784
3785/*
3786 * Delete the record pointed to by cur.
3787 * The cursor refers to the place where the record was (could be inserted)
3788 * when the operation returns.
3789 */
3790int /* error */
3791xfs_btree_delete(
3792 struct xfs_btree_cur *cur,
3793 int *stat) /* success/failure */
3794{
3795 int error; /* error return value */
3796 int level;
3797 int i;
3798
3799 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3800
3801 /*
3802 * Go up the tree, starting at leaf level.
3803 *
3804 * If 2 is returned then a join was done; go to the next level.
3805 * Otherwise we are done.
3806 */
3807 for (level = 0, i = 2; i == 2; level++) {
3808 error = xfs_btree_delrec(cur, level, &i);
3809 if (error)
3810 goto error0;
3811 }
3812
3813 if (i == 0) {
3814 for (level = 1; level < cur->bc_nlevels; level++) {
3815 if (cur->bc_ptrs[level] == 0) {
3816 error = xfs_btree_decrement(cur, level, &i);
3817 if (error)
3818 goto error0;
3819 break;
3820 }
3821 }
3822 }
3823
3824 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3825 *stat = i;
3826 return 0;
3827error0:
3828 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3829 return error;
3830}
8cc938fe
CH		 3831
3832/*
3833 * Get the data from the pointed-to record.
3834 */
3835int /* error */
3836xfs_btree_get_rec(
3837 struct xfs_btree_cur *cur, /* btree cursor */
3838 union xfs_btree_rec **recp, /* output: btree record */
3839 int *stat) /* output: success/failure */
3840{
3841 struct xfs_btree_block *block; /* btree block */
3842 struct xfs_buf *bp; /* buffer pointer */
3843 int ptr; /* record number */
3844#ifdef DEBUG
3845 int error; /* error return value */
3846#endif
3847
3848 ptr = cur->bc_ptrs[0];
3849 block = xfs_btree_get_block(cur, 0, &bp);
3850
3851#ifdef DEBUG
3852 error = xfs_btree_check_block(cur, block, 0, bp);
3853 if (error)
3854 return error;
3855#endif
3856
3857 /*
3858 * Off the right end or left end, return failure.
3859 */
3860 if (ptr > xfs_btree_get_numrecs(block) || ptr <= 0) {
3861 *stat = 0;
3862 return 0;
3863 }
3864
3865 /*
3866 * Point to the record and extract its data.
3867 */
3868 *recp = xfs_btree_rec_addr(cur, ptr, block);
3869 *stat = 1;
3870 return 0;
3871}
Linux kernel - Deliverables
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