projects / GitHub / mt8127 / android_kernel_alcatel_ttab.git / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
xfs: connect up write verifiers to new buffers
[GitHub/mt8127/android_kernel_alcatel_ttab.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"
a844f451 33#include "xfs_btree.h"
1da177e4 34#include "xfs_error.h"
0b1b213f 35#include "xfs_trace.h"
1da177e4
LT		 36
37/*
38 * Cursor allocation zone.
39 */
40kmem_zone_t *xfs_btree_cur_zone;
41
42/*
43 * Btree magic numbers.
44 */
cdcf4333 45const __uint32_t xfs_magics[XFS_BTNUM_MAX] = {
1da177e4
LT		 46 XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, XFS_BMAP_MAGIC, XFS_IBT_MAGIC
47};
48
1da177e4 49
7cc95a82 50STATIC int /* error (0 or EFSCORRUPTED) */
a23f6ef8
CH		 51xfs_btree_check_lblock(
52 struct xfs_btree_cur *cur, /* btree cursor */
7cc95a82 53 struct xfs_btree_block *block, /* btree long form block pointer */
a23f6ef8
CH		 54 int level, /* level of the btree block */
55 struct xfs_buf *bp) /* buffer for block, if any */
56{
57 int lblock_ok; /* block passes checks */
58 struct xfs_mount *mp; /* file system mount point */
59
60 mp = cur->bc_mp;
61 lblock_ok =
62 be32_to_cpu(block->bb_magic) == xfs_magics[cur->bc_btnum] &&
63 be16_to_cpu(block->bb_level) == level &&
64 be16_to_cpu(block->bb_numrecs) <=
ce5e42db 65 cur->bc_ops->get_maxrecs(cur, level) &&
7cc95a82 66 block->bb_u.l.bb_leftsib &&
69ef921b 67 (block->bb_u.l.bb_leftsib == cpu_to_be64(NULLDFSBNO) ||
7cc95a82
CH		 68 XFS_FSB_SANITY_CHECK(mp,
69 be64_to_cpu(block->bb_u.l.bb_leftsib))) &&
70 block->bb_u.l.bb_rightsib &&
69ef921b 71 (block->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO) ||
7cc95a82
CH		 72 XFS_FSB_SANITY_CHECK(mp,
73 be64_to_cpu(block->bb_u.l.bb_rightsib)));
a23f6ef8
CH		 74 if (unlikely(XFS_TEST_ERROR(!lblock_ok, mp,
75 XFS_ERRTAG_BTREE_CHECK_LBLOCK,
76 XFS_RANDOM_BTREE_CHECK_LBLOCK))) {
77 if (bp)
0b1b213f 78 trace_xfs_btree_corrupt(bp, _RET_IP_);
a23f6ef8
CH		 79 XFS_ERROR_REPORT("xfs_btree_check_lblock", XFS_ERRLEVEL_LOW,
80 mp);
81 return XFS_ERROR(EFSCORRUPTED);
82 }
83 return 0;
84}
85
3cc7524c 86STATIC int /* error (0 or EFSCORRUPTED) */
1da177e4 87xfs_btree_check_sblock(
a23f6ef8 88 struct xfs_btree_cur *cur, /* btree cursor */
7cc95a82 89 struct xfs_btree_block *block, /* btree short form block pointer */
1da177e4 90 int level, /* level of the btree block */
a23f6ef8 91 struct xfs_buf *bp) /* buffer containing block */
1da177e4 92{
a23f6ef8
CH		 93 struct xfs_buf *agbp; /* buffer for ag. freespace struct */
94 struct xfs_agf *agf; /* ag. freespace structure */
1da177e4
LT		 95 xfs_agblock_t agflen; /* native ag. freespace length */
96 int sblock_ok; /* block passes checks */
97
98 agbp = cur->bc_private.a.agbp;
99 agf = XFS_BUF_TO_AGF(agbp);
16259e7d 100 agflen = be32_to_cpu(agf->agf_length);
1da177e4 101 sblock_ok =
16259e7d
CH		 102 be32_to_cpu(block->bb_magic) == xfs_magics[cur->bc_btnum] &&
103 be16_to_cpu(block->bb_level) == level &&
104 be16_to_cpu(block->bb_numrecs) <=
ce5e42db 105 cur->bc_ops->get_maxrecs(cur, level) &&
69ef921b 106 (block->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK) ||
7cc95a82
CH		 107 be32_to_cpu(block->bb_u.s.bb_leftsib) < agflen) &&
108 block->bb_u.s.bb_leftsib &&
69ef921b 109 (block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK) ||
7cc95a82
CH		 110 be32_to_cpu(block->bb_u.s.bb_rightsib) < agflen) &&
111 block->bb_u.s.bb_rightsib;
1da177e4
LT		 112 if (unlikely(XFS_TEST_ERROR(!sblock_ok, cur->bc_mp,
113 XFS_ERRTAG_BTREE_CHECK_SBLOCK,
114 XFS_RANDOM_BTREE_CHECK_SBLOCK))) {
115 if (bp)
0b1b213f 116 trace_xfs_btree_corrupt(bp, _RET_IP_);
e0c222c4
ES		 117 XFS_CORRUPTION_ERROR("xfs_btree_check_sblock",
118 XFS_ERRLEVEL_LOW, cur->bc_mp, block);
1da177e4
LT		 119 return XFS_ERROR(EFSCORRUPTED);
120 }
121 return 0;
122}
123
124/*
a23f6ef8
CH		 125 * Debug routine: check that block header is ok.
126 */
127int
128xfs_btree_check_block(
129 struct xfs_btree_cur *cur, /* btree cursor */
130 struct xfs_btree_block *block, /* generic btree block pointer */
131 int level, /* level of the btree block */
132 struct xfs_buf *bp) /* buffer containing block, if any */
133{
7cc95a82
CH		 134 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
135 return xfs_btree_check_lblock(cur, block, level, bp);
136 else
137 return xfs_btree_check_sblock(cur, block, level, bp);
a23f6ef8
CH		 138}
139
140/*
141 * Check that (long) pointer is ok.
142 */
143int /* error (0 or EFSCORRUPTED) */
144xfs_btree_check_lptr(
145 struct xfs_btree_cur *cur, /* btree cursor */
146 xfs_dfsbno_t bno, /* btree block disk address */
147 int level) /* btree block level */
148{
149 XFS_WANT_CORRUPTED_RETURN(
150 level > 0 &&
151 bno != NULLDFSBNO &&
152 XFS_FSB_SANITY_CHECK(cur->bc_mp, bno));
153 return 0;
154}
155
24ee0e49 156#ifdef DEBUG
a23f6ef8
CH		 157/*
158 * Check that (short) pointer is ok.
1da177e4 159 */
3cc7524c 160STATIC int /* error (0 or EFSCORRUPTED) */
1da177e4 161xfs_btree_check_sptr(
a23f6ef8
CH		 162 struct xfs_btree_cur *cur, /* btree cursor */
163 xfs_agblock_t bno, /* btree block disk address */
164 int level) /* btree block level */
1da177e4 165{
a23f6ef8 166 xfs_agblock_t agblocks = cur->bc_mp->m_sb.sb_agblocks;
1da177e4 167
1da177e4
LT		 168 XFS_WANT_CORRUPTED_RETURN(
169 level > 0 &&
a23f6ef8
CH		 170 bno != NULLAGBLOCK &&
171 bno != 0 &&
172 bno < agblocks);
1da177e4
LT		 173 return 0;
174}
175
a23f6ef8
CH		 176/*
177 * Check that block ptr is ok.
178 */
3cc7524c 179STATIC int /* error (0 or EFSCORRUPTED) */
a23f6ef8
CH		 180xfs_btree_check_ptr(
181 struct xfs_btree_cur *cur, /* btree cursor */
182 union xfs_btree_ptr *ptr, /* btree block disk address */
183 int index, /* offset from ptr to check */
184 int level) /* btree block level */
185{
186 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
187 return xfs_btree_check_lptr(cur,
188 be64_to_cpu((&ptr->l)[index]), level);
189 } else {
190 return xfs_btree_check_sptr(cur,
191 be32_to_cpu((&ptr->s)[index]), level);
192 }
193}
24ee0e49 194#endif
a23f6ef8 195
1da177e4
LT		 196/*
197 * Delete the btree cursor.
198 */
199void
200xfs_btree_del_cursor(
201 xfs_btree_cur_t *cur, /* btree cursor */
202 int error) /* del because of error */
203{
204 int i; /* btree level */
205
206 /*
207 * Clear the buffer pointers, and release the buffers.
208 * If we're doing this in the face of an error, we
209 * need to make sure to inspect all of the entries
210 * in the bc_bufs array for buffers to be unlocked.
211 * This is because some of the btree code works from
212 * level n down to 0, and if we get an error along
213 * the way we won't have initialized all the entries
214 * down to 0.
215 */
216 for (i = 0; i < cur->bc_nlevels; i++) {
217 if (cur->bc_bufs[i])
c0e59e1a 218 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[i]);
1da177e4
LT		 219 else if (!error)
220 break;
221 }
222 /*
223 * Can't free a bmap cursor without having dealt with the
224 * allocated indirect blocks' accounting.
225 */
226 ASSERT(cur->bc_btnum != XFS_BTNUM_BMAP ||
227 cur->bc_private.b.allocated == 0);
228 /*
229 * Free the cursor.
230 */
231 kmem_zone_free(xfs_btree_cur_zone, cur);
232}
233
234/*
235 * Duplicate the btree cursor.
236 * Allocate a new one, copy the record, re-get the buffers.
237 */
238int /* error */
239xfs_btree_dup_cursor(
240 xfs_btree_cur_t *cur, /* input cursor */
241 xfs_btree_cur_t **ncur) /* output cursor */
242{
243 xfs_buf_t *bp; /* btree block's buffer pointer */
244 int error; /* error return value */
245 int i; /* level number of btree block */
246 xfs_mount_t *mp; /* mount structure for filesystem */
247 xfs_btree_cur_t *new; /* new cursor value */
248 xfs_trans_t *tp; /* transaction pointer, can be NULL */
249
250 tp = cur->bc_tp;
251 mp = cur->bc_mp;
561f7d17 252
1da177e4
LT		 253 /*
254 * Allocate a new cursor like the old one.
255 */
561f7d17
CH		 256 new = cur->bc_ops->dup_cursor(cur);
257
1da177e4
LT		 258 /*
259 * Copy the record currently in the cursor.
260 */
261 new->bc_rec = cur->bc_rec;
561f7d17 262
1da177e4
LT		 263 /*
264 * For each level current, re-get the buffer and copy the ptr value.
265 */
266 for (i = 0; i < new->bc_nlevels; i++) {
267 new->bc_ptrs[i] = cur->bc_ptrs[i];
268 new->bc_ra[i] = cur->bc_ra[i];
c3f8fc73
DC		 269 bp = cur->bc_bufs[i];
270 if (bp) {
271 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
272 XFS_BUF_ADDR(bp), mp->m_bsize,
3d3e6f64
DC		 273 0, &bp,
274 cur->bc_ops->read_verify);
c3f8fc73 275 if (error) {
1da177e4
LT		 276 xfs_btree_del_cursor(new, error);
277 *ncur = NULL;
278 return error;
279 }
280 new->bc_bufs[i] = bp;
5a52c2a5 281 ASSERT(!xfs_buf_geterror(bp));
1da177e4
LT		 282 } else
283 new->bc_bufs[i] = NULL;
284 }
1da177e4
LT		 285 *ncur = new;
286 return 0;
287}
288
65f1eaea
CH		 289/*
290 * XFS btree block layout and addressing:
291 *
292 * There are two types of blocks in the btree: leaf and non-leaf blocks.
293 *
294 * The leaf record start with a header then followed by records containing
295 * the values. A non-leaf block also starts with the same header, and
296 * then first contains lookup keys followed by an equal number of pointers
297 * to the btree blocks at the previous level.
298 *
299 * +--------+-------+-------+-------+-------+-------+-------+
300 * Leaf: | header | rec 1 | rec 2 | rec 3 | rec 4 | rec 5 | rec N |
301 * +--------+-------+-------+-------+-------+-------+-------+
302 *
303 * +--------+-------+-------+-------+-------+-------+-------+
304 * Non-Leaf: | header | key 1 | key 2 | key N | ptr 1 | ptr 2 | ptr N |
305 * +--------+-------+-------+-------+-------+-------+-------+
306 *
307 * The header is called struct xfs_btree_block for reasons better left unknown
308 * and comes in different versions for short (32bit) and long (64bit) block
309 * pointers. The record and key structures are defined by the btree instances
310 * and opaque to the btree core. The block pointers are simple disk endian
311 * integers, available in a short (32bit) and long (64bit) variant.
312 *
313 * The helpers below calculate the offset of a given record, key or pointer
314 * into a btree block (xfs_btree_*_offset) or return a pointer to the given
315 * record, key or pointer (xfs_btree_*_addr). Note that all addressing
316 * inside the btree block is done using indices starting at one, not zero!
317 */
318
319/*
320 * Return size of the btree block header for this btree instance.
321 */
322static inline size_t xfs_btree_block_len(struct xfs_btree_cur *cur)
323{
324 return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
7cc95a82
CH		 325 XFS_BTREE_LBLOCK_LEN :
326 XFS_BTREE_SBLOCK_LEN;
65f1eaea
CH		 327}
328
329/*
330 * Return size of btree block pointers for this btree instance.
331 */
332static inline size_t xfs_btree_ptr_len(struct xfs_btree_cur *cur)
333{
334 return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
335 sizeof(__be64) : sizeof(__be32);
336}
337
338/*
339 * Calculate offset of the n-th record in a btree block.
340 */
341STATIC size_t
342xfs_btree_rec_offset(
343 struct xfs_btree_cur *cur,
344 int n)
345{
346 return xfs_btree_block_len(cur) +
347 (n - 1) * cur->bc_ops->rec_len;
348}
349
350/*
351 * Calculate offset of the n-th key in a btree block.
352 */
353STATIC size_t
354xfs_btree_key_offset(
355 struct xfs_btree_cur *cur,
356 int n)
357{
358 return xfs_btree_block_len(cur) +
359 (n - 1) * cur->bc_ops->key_len;
360}
361
362/*
363 * Calculate offset of the n-th block pointer in a btree block.
364 */
365STATIC size_t
366xfs_btree_ptr_offset(
367 struct xfs_btree_cur *cur,
368 int n,
369 int level)
370{
371 return xfs_btree_block_len(cur) +
372 cur->bc_ops->get_maxrecs(cur, level) * cur->bc_ops->key_len +
373 (n - 1) * xfs_btree_ptr_len(cur);
374}
375
376/*
377 * Return a pointer to the n-th record in the btree block.
378 */
379STATIC union xfs_btree_rec *
380xfs_btree_rec_addr(
381 struct xfs_btree_cur *cur,
382 int n,
383 struct xfs_btree_block *block)
384{
385 return (union xfs_btree_rec *)
386 ((char *)block + xfs_btree_rec_offset(cur, n));
387}
388
389/*
390 * Return a pointer to the n-th key in the btree block.
391 */
392STATIC union xfs_btree_key *
393xfs_btree_key_addr(
394 struct xfs_btree_cur *cur,
395 int n,
396 struct xfs_btree_block *block)
397{
398 return (union xfs_btree_key *)
399 ((char *)block + xfs_btree_key_offset(cur, n));
400}
401
402/*
403 * Return a pointer to the n-th block pointer in the btree block.
404 */
405STATIC union xfs_btree_ptr *
406xfs_btree_ptr_addr(
407 struct xfs_btree_cur *cur,
408 int n,
409 struct xfs_btree_block *block)
410{
411 int level = xfs_btree_get_level(block);
412
413 ASSERT(block->bb_level != 0);
414
415 return (union xfs_btree_ptr *)
416 ((char *)block + xfs_btree_ptr_offset(cur, n, level));
417}
418
8186e517
CH		 419/*
420 * Get a the root block which is stored in the inode.
421 *
422 * For now this btree implementation assumes the btree root is always
423 * stored in the if_broot field of an inode fork.
424 */
425STATIC struct xfs_btree_block *
426xfs_btree_get_iroot(
427 struct xfs_btree_cur *cur)
428{
429 struct xfs_ifork *ifp;
430
431 ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, cur->bc_private.b.whichfork);
432 return (struct xfs_btree_block *)ifp->if_broot;
433}
434
1da177e4
LT		 435/*
436 * Retrieve the block pointer from the cursor at the given level.
8186e517 437 * This may be an inode btree root or from a buffer.
1da177e4 438 */
8186e517 439STATIC struct xfs_btree_block * /* generic btree block pointer */
1da177e4 440xfs_btree_get_block(
8186e517 441 struct xfs_btree_cur *cur, /* btree cursor */
1da177e4 442 int level, /* level in btree */
8186e517 443 struct xfs_buf **bpp) /* buffer containing the block */
1da177e4 444{
8186e517
CH		 445 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
446 (level == cur->bc_nlevels - 1)) {
447 *bpp = NULL;
448 return xfs_btree_get_iroot(cur);
1da177e4 449 }
8186e517
CH		 450
451 *bpp = cur->bc_bufs[level];
452 return XFS_BUF_TO_BLOCK(*bpp);
1da177e4
LT		 453}
454
455/*
456 * Get a buffer for the block, return it with no data read.
457 * Long-form addressing.
458 */
459xfs_buf_t * /* buffer for fsbno */
460xfs_btree_get_bufl(
461 xfs_mount_t *mp, /* file system mount point */
462 xfs_trans_t *tp, /* transaction pointer */
463 xfs_fsblock_t fsbno, /* file system block number */
464 uint lock) /* lock flags for get_buf */
465{
466 xfs_buf_t *bp; /* buffer pointer (return value) */
467 xfs_daddr_t d; /* real disk block address */
468
469 ASSERT(fsbno != NULLFSBLOCK);
470 d = XFS_FSB_TO_DADDR(mp, fsbno);
471 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
5a52c2a5 472 ASSERT(!xfs_buf_geterror(bp));
1da177e4
LT		 473 return bp;
474}
475
476/*
477 * Get a buffer for the block, return it with no data read.
478 * Short-form addressing.
479 */
480xfs_buf_t * /* buffer for agno/agbno */
481xfs_btree_get_bufs(
482 xfs_mount_t *mp, /* file system mount point */
483 xfs_trans_t *tp, /* transaction pointer */
484 xfs_agnumber_t agno, /* allocation group number */
485 xfs_agblock_t agbno, /* allocation group block number */
486 uint lock) /* lock flags for get_buf */
487{
488 xfs_buf_t *bp; /* buffer pointer (return value) */
489 xfs_daddr_t d; /* real disk block address */
490
491 ASSERT(agno != NULLAGNUMBER);
492 ASSERT(agbno != NULLAGBLOCK);
493 d = XFS_AGB_TO_DADDR(mp, agno, agbno);
494 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
5a52c2a5 495 ASSERT(!xfs_buf_geterror(bp));
1da177e4
LT		 496 return bp;
497}
498
1da177e4
LT		 499/*
500 * Check for the cursor referring to the last block at the given level.
501 */
502int /* 1=is last block, 0=not last block */
503xfs_btree_islastblock(
504 xfs_btree_cur_t *cur, /* btree cursor */
505 int level) /* level to check */
506{
7cc95a82 507 struct xfs_btree_block *block; /* generic btree block pointer */
1da177e4
LT		 508 xfs_buf_t *bp; /* buffer containing block */
509
510 block = xfs_btree_get_block(cur, level, &bp);
511 xfs_btree_check_block(cur, block, level, bp);
e99ab90d 512 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
69ef921b 513 return block->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO);
1da177e4 514 else
69ef921b 515 return block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK);
1da177e4
LT		 516}
517
cdcf4333
CH		 518/*
519 * Change the cursor to point to the first record at the given level.
520 * Other levels are unaffected.
521 */
3cc7524c 522STATIC int /* success=1, failure=0 */
cdcf4333
CH		 523xfs_btree_firstrec(
524 xfs_btree_cur_t *cur, /* btree cursor */
525 int level) /* level to change */
526{
7cc95a82 527 struct xfs_btree_block *block; /* generic btree block pointer */
cdcf4333
CH		 528 xfs_buf_t *bp; /* buffer containing block */
529
530 /*
531 * Get the block pointer for this level.
532 */
533 block = xfs_btree_get_block(cur, level, &bp);
534 xfs_btree_check_block(cur, block, level, bp);
535 /*
536 * It's empty, there is no such record.
537 */
f2277f06 538 if (!block->bb_numrecs)
cdcf4333
CH		 539 return 0;
540 /*
541 * Set the ptr value to 1, that's the first record/key.
542 */
543 cur->bc_ptrs[level] = 1;
544 return 1;
545}
546
1da177e4
LT		 547/*
548 * Change the cursor to point to the last record in the current block
549 * at the given level. Other levels are unaffected.
550 */
3cc7524c 551STATIC int /* success=1, failure=0 */
1da177e4
LT		 552xfs_btree_lastrec(
553 xfs_btree_cur_t *cur, /* btree cursor */
554 int level) /* level to change */
555{
7cc95a82 556 struct xfs_btree_block *block; /* generic btree block pointer */
1da177e4
LT		 557 xfs_buf_t *bp; /* buffer containing block */
558
559 /*
560 * Get the block pointer for this level.
561 */
562 block = xfs_btree_get_block(cur, level, &bp);
563 xfs_btree_check_block(cur, block, level, bp);
564 /*
565 * It's empty, there is no such record.
566 */
f2277f06 567 if (!block->bb_numrecs)
1da177e4
LT		 568 return 0;
569 /*
570 * Set the ptr value to numrecs, that's the last record/key.
571 */
f2277f06 572 cur->bc_ptrs[level] = be16_to_cpu(block->bb_numrecs);
1da177e4
LT		 573 return 1;
574}
575
576/*
577 * Compute first and last byte offsets for the fields given.
578 * Interprets the offsets table, which contains struct field offsets.
579 */
580void
581xfs_btree_offsets(
582 __int64_t fields, /* bitmask of fields */
583 const short *offsets, /* table of field offsets */
584 int nbits, /* number of bits to inspect */
585 int *first, /* output: first byte offset */
586 int *last) /* output: last byte offset */
587{
588 int i; /* current bit number */
589 __int64_t imask; /* mask for current bit number */
590
591 ASSERT(fields != 0);
592 /*
593 * Find the lowest bit, so the first byte offset.
594 */
595 for (i = 0, imask = 1LL; ; i++, imask <<= 1) {
596 if (imask & fields) {
597 *first = offsets[i];
598 break;
599 }
600 }
601 /*
602 * Find the highest bit, so the last byte offset.
603 */
604 for (i = nbits - 1, imask = 1LL << i; ; i--, imask >>= 1) {
605 if (imask & fields) {
606 *last = offsets[i + 1] - 1;
607 break;
608 }
609 }
610}
611
612/*
613 * Get a buffer for the block, return it read in.
614 * Long-form addressing.
615 */
3d3e6f64 616int
1da177e4 617xfs_btree_read_bufl(
3d3e6f64
DC		 618 struct xfs_mount *mp, /* file system mount point */
619 struct xfs_trans *tp, /* transaction pointer */
620 xfs_fsblock_t fsbno, /* file system block number */
621 uint lock, /* lock flags for read_buf */
622 struct xfs_buf **bpp, /* buffer for fsbno */
623 int refval, /* ref count value for buffer */
624 xfs_buf_iodone_t verify)
1da177e4 625{
3d3e6f64 626 struct xfs_buf *bp; /* return value */
1da177e4 627 xfs_daddr_t d; /* real disk block address */
3d3e6f64 628 int error;
1da177e4
LT		 629
630 ASSERT(fsbno != NULLFSBLOCK);
631 d = XFS_FSB_TO_DADDR(mp, fsbno);
c3f8fc73 632 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
3d3e6f64 633 mp->m_bsize, lock, &bp, verify);
c3f8fc73 634 if (error)
1da177e4 635 return error;
5a52c2a5 636 ASSERT(!xfs_buf_geterror(bp));
821eb21d 637 if (bp)
38f23232 638 xfs_buf_set_ref(bp, refval);
1da177e4
LT		 639 *bpp = bp;
640 return 0;
641}
642
1da177e4
LT		 643/*
644 * Read-ahead the block, don't wait for it, don't return a buffer.
645 * Long-form addressing.
646 */
647/* ARGSUSED */
648void
649xfs_btree_reada_bufl(
3d3e6f64
DC		 650 struct xfs_mount *mp, /* file system mount point */
651 xfs_fsblock_t fsbno, /* file system block number */
652 xfs_extlen_t count, /* count of filesystem blocks */
653 xfs_buf_iodone_t verify)
1da177e4
LT		 654{
655 xfs_daddr_t d;
656
657 ASSERT(fsbno != NULLFSBLOCK);
658 d = XFS_FSB_TO_DADDR(mp, fsbno);
3d3e6f64 659 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, verify);
1da177e4
LT		 660}
661
662/*
663 * Read-ahead the block, don't wait for it, don't return a buffer.
664 * Short-form addressing.
665 */
666/* ARGSUSED */
667void
668xfs_btree_reada_bufs(
3d3e6f64
DC		 669 struct xfs_mount *mp, /* file system mount point */
670 xfs_agnumber_t agno, /* allocation group number */
671 xfs_agblock_t agbno, /* allocation group block number */
672 xfs_extlen_t count, /* count of filesystem blocks */
673 xfs_buf_iodone_t verify)
1da177e4
LT		 674{
675 xfs_daddr_t d;
676
677 ASSERT(agno != NULLAGNUMBER);
678 ASSERT(agbno != NULLAGBLOCK);
679 d = XFS_AGB_TO_DADDR(mp, agno, agbno);
3d3e6f64 680 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, verify);
1da177e4
LT		 681}
682
b524bfee
CH		 683STATIC int
684xfs_btree_readahead_lblock(
685 struct xfs_btree_cur *cur,
686 int lr,
687 struct xfs_btree_block *block)
688{
689 int rval = 0;
e6edbd1c
CH		 690 xfs_dfsbno_t left = be64_to_cpu(block->bb_u.l.bb_leftsib);
691 xfs_dfsbno_t right = be64_to_cpu(block->bb_u.l.bb_rightsib);
b524bfee
CH		 692
693 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLDFSBNO) {
3d3e6f64
DC		 694 xfs_btree_reada_bufl(cur->bc_mp, left, 1,
695 cur->bc_ops->read_verify);
b524bfee
CH		 696 rval++;
697 }
698
699 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLDFSBNO) {
3d3e6f64
DC		 700 xfs_btree_reada_bufl(cur->bc_mp, right, 1,
701 cur->bc_ops->read_verify);
b524bfee
CH		 702 rval++;
703 }
704
705 return rval;
706}
707
708STATIC int
709xfs_btree_readahead_sblock(
710 struct xfs_btree_cur *cur,
711 int lr,
712 struct xfs_btree_block *block)
713{
714 int rval = 0;
715 xfs_agblock_t left = be32_to_cpu(block->bb_u.s.bb_leftsib);
716 xfs_agblock_t right = be32_to_cpu(block->bb_u.s.bb_rightsib);
717
718
719 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLAGBLOCK) {
720 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
3d3e6f64 721 left, 1, cur->bc_ops->read_verify);
b524bfee
CH		 722 rval++;
723 }
724
725 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLAGBLOCK) {
726 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
3d3e6f64 727 right, 1, cur->bc_ops->read_verify);
b524bfee
CH		 728 rval++;
729 }
730
731 return rval;
732}
733
1da177e4
LT		 734/*
735 * Read-ahead btree blocks, at the given level.
736 * Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA.
737 */
3cc7524c 738STATIC int
b524bfee
CH		 739xfs_btree_readahead(
740 struct xfs_btree_cur *cur, /* btree cursor */
1da177e4
LT		 741 int lev, /* level in btree */
742 int lr) /* left/right bits */
743{
b524bfee
CH		 744 struct xfs_btree_block *block;
745
746 /*
747 * No readahead needed if we are at the root level and the
748 * btree root is stored in the inode.
749 */
750 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
751 (lev == cur->bc_nlevels - 1))
752 return 0;
753
754 if ((cur->bc_ra[lev] | lr) == cur->bc_ra[lev])
755 return 0;
1da177e4 756
1da177e4 757 cur->bc_ra[lev] |= lr;
b524bfee
CH		 758 block = XFS_BUF_TO_BLOCK(cur->bc_bufs[lev]);
759
760 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
761 return xfs_btree_readahead_lblock(cur, lr, block);
762 return xfs_btree_readahead_sblock(cur, lr, block);
1da177e4
LT		 763}
764
765/*
766 * Set the buffer for level "lev" in the cursor to bp, releasing
767 * any previous buffer.
768 */
c0e59e1a 769STATIC void
1da177e4
LT		 770xfs_btree_setbuf(
771 xfs_btree_cur_t *cur, /* btree cursor */
772 int lev, /* level in btree */
773 xfs_buf_t *bp) /* new buffer to set */
774{
7cc95a82 775 struct xfs_btree_block *b; /* btree block */
1da177e4 776
c0e59e1a
CH		 777 if (cur->bc_bufs[lev])
778 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[lev]);
1da177e4
LT		 779 cur->bc_bufs[lev] = bp;
780 cur->bc_ra[lev] = 0;
c0e59e1a 781
1da177e4 782 b = XFS_BUF_TO_BLOCK(bp);
e99ab90d 783 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
69ef921b 784 if (b->bb_u.l.bb_leftsib == cpu_to_be64(NULLDFSBNO))
1da177e4 785 cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
69ef921b 786 if (b->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO))
1da177e4
LT		 787 cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
788 } else {
69ef921b 789 if (b->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK))
1da177e4 790 cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
69ef921b 791 if (b->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK))
1da177e4
LT		 792 cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
793 }
794}
637aa50f
CH		 795
796STATIC int
797xfs_btree_ptr_is_null(
798 struct xfs_btree_cur *cur,
799 union xfs_btree_ptr *ptr)
800{
801 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
69ef921b 802 return ptr->l == cpu_to_be64(NULLDFSBNO);
637aa50f 803 else
69ef921b 804 return ptr->s == cpu_to_be32(NULLAGBLOCK);
637aa50f
CH		 805}
806
4b22a571
CH		 807STATIC void
808xfs_btree_set_ptr_null(
809 struct xfs_btree_cur *cur,
810 union xfs_btree_ptr *ptr)
811{
812 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
33ad965d 813 ptr->l = cpu_to_be64(NULLDFSBNO);
4b22a571
CH		 814 else
815 ptr->s = cpu_to_be32(NULLAGBLOCK);
816}
817
637aa50f
CH		 818/*
819 * Get/set/init sibling pointers
820 */
821STATIC void
822xfs_btree_get_sibling(
823 struct xfs_btree_cur *cur,
824 struct xfs_btree_block *block,
825 union xfs_btree_ptr *ptr,
826 int lr)
827{
828 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
829
830 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
831 if (lr == XFS_BB_RIGHTSIB)
832 ptr->l = block->bb_u.l.bb_rightsib;
833 else
834 ptr->l = block->bb_u.l.bb_leftsib;
835 } else {
836 if (lr == XFS_BB_RIGHTSIB)
837 ptr->s = block->bb_u.s.bb_rightsib;
838 else
839 ptr->s = block->bb_u.s.bb_leftsib;
840 }
841}
842
f5eb8e7c
CH		 843STATIC void
844xfs_btree_set_sibling(
845 struct xfs_btree_cur *cur,
846 struct xfs_btree_block *block,
847 union xfs_btree_ptr *ptr,
848 int lr)
849{
850 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
851
852 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
853 if (lr == XFS_BB_RIGHTSIB)
854 block->bb_u.l.bb_rightsib = ptr->l;
855 else
856 block->bb_u.l.bb_leftsib = ptr->l;
857 } else {
858 if (lr == XFS_BB_RIGHTSIB)
859 block->bb_u.s.bb_rightsib = ptr->s;
860 else
861 block->bb_u.s.bb_leftsib = ptr->s;
862 }
863}
864
b64f3a39 865void
f5eb8e7c 866xfs_btree_init_block(
b64f3a39
DC		 867 struct xfs_mount *mp,
868 struct xfs_buf *bp,
869 __u32 magic,
870 __u16 level,
871 __u16 numrecs,
872 unsigned int flags)
f5eb8e7c 873{
b64f3a39
DC		 874 struct xfs_btree_block *new = XFS_BUF_TO_BLOCK(bp);
875
876 new->bb_magic = cpu_to_be32(magic);
f5eb8e7c
CH		 877 new->bb_level = cpu_to_be16(level);
878 new->bb_numrecs = cpu_to_be16(numrecs);
879
b64f3a39 880 if (flags & XFS_BTREE_LONG_PTRS) {
33ad965d
DC		 881 new->bb_u.l.bb_leftsib = cpu_to_be64(NULLDFSBNO);
882 new->bb_u.l.bb_rightsib = cpu_to_be64(NULLDFSBNO);
f5eb8e7c
CH		 883 } else {
884 new->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
885 new->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
886 }
887}
888
b64f3a39
DC		 889STATIC void
890xfs_btree_init_block_cur(
891 struct xfs_btree_cur *cur,
892 int level,
893 int numrecs,
894 struct xfs_buf *bp)
895{
896 xfs_btree_init_block(cur->bc_mp, bp, xfs_magics[cur->bc_btnum],
897 level, numrecs, cur->bc_flags);
898}
899
278d0ca1
CH		 900/*
901 * Return true if ptr is the last record in the btree and
902 * we need to track updateѕ to this record. The decision
903 * will be further refined in the update_lastrec method.
904 */
905STATIC int
906xfs_btree_is_lastrec(
907 struct xfs_btree_cur *cur,
908 struct xfs_btree_block *block,
909 int level)
910{
911 union xfs_btree_ptr ptr;
912
913 if (level > 0)
914 return 0;
915 if (!(cur->bc_flags & XFS_BTREE_LASTREC_UPDATE))
916 return 0;
917
918 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
919 if (!xfs_btree_ptr_is_null(cur, &ptr))
920 return 0;
921 return 1;
922}
923
f5eb8e7c
CH		 924STATIC void
925xfs_btree_buf_to_ptr(
926 struct xfs_btree_cur *cur,
927 struct xfs_buf *bp,
928 union xfs_btree_ptr *ptr)
929{
930 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
931 ptr->l = cpu_to_be64(XFS_DADDR_TO_FSB(cur->bc_mp,
932 XFS_BUF_ADDR(bp)));
933 else {
9d87c319 934 ptr->s = cpu_to_be32(xfs_daddr_to_agbno(cur->bc_mp,
f5eb8e7c
CH		 935 XFS_BUF_ADDR(bp)));
936 }
937}
938
637aa50f
CH		 939STATIC xfs_daddr_t
940xfs_btree_ptr_to_daddr(
941 struct xfs_btree_cur *cur,
942 union xfs_btree_ptr *ptr)
943{
944 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
69ef921b 945 ASSERT(ptr->l != cpu_to_be64(NULLDFSBNO));
637aa50f
CH		 946
947 return XFS_FSB_TO_DADDR(cur->bc_mp, be64_to_cpu(ptr->l));
948 } else {
949 ASSERT(cur->bc_private.a.agno != NULLAGNUMBER);
69ef921b 950 ASSERT(ptr->s != cpu_to_be32(NULLAGBLOCK));
637aa50f
CH		 951
952 return XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_private.a.agno,
953 be32_to_cpu(ptr->s));
954 }
955}
956
957STATIC void
958xfs_btree_set_refs(
959 struct xfs_btree_cur *cur,
960 struct xfs_buf *bp)
961{
962 switch (cur->bc_btnum) {
963 case XFS_BTNUM_BNO:
964 case XFS_BTNUM_CNT:
38f23232 965 xfs_buf_set_ref(bp, XFS_ALLOC_BTREE_REF);
637aa50f
CH		 966 break;
967 case XFS_BTNUM_INO:
38f23232 968 xfs_buf_set_ref(bp, XFS_INO_BTREE_REF);
637aa50f
CH		 969 break;
970 case XFS_BTNUM_BMAP:
38f23232 971 xfs_buf_set_ref(bp, XFS_BMAP_BTREE_REF);
637aa50f
CH		 972 break;
973 default:
974 ASSERT(0);
975 }
976}
977
f5eb8e7c
CH		 978STATIC int
979xfs_btree_get_buf_block(
980 struct xfs_btree_cur *cur,
981 union xfs_btree_ptr *ptr,
982 int flags,
983 struct xfs_btree_block **block,
984 struct xfs_buf **bpp)
985{
986 struct xfs_mount *mp = cur->bc_mp;
987 xfs_daddr_t d;
988
989 /* need to sort out how callers deal with failures first */
0cadda1c 990 ASSERT(!(flags & XBF_TRYLOCK));
f5eb8e7c
CH		 991
992 d = xfs_btree_ptr_to_daddr(cur, ptr);
993 *bpp = xfs_trans_get_buf(cur->bc_tp, mp->m_ddev_targp, d,
994 mp->m_bsize, flags);
995
2a30f36d
CS		 996 if (!*bpp)
997 return ENOMEM;
f5eb8e7c 998
b0f539de 999 (*bpp)->b_pre_io = cur->bc_ops->write_verify;
f5eb8e7c
CH		 1000 *block = XFS_BUF_TO_BLOCK(*bpp);
1001 return 0;
1002}
1003
637aa50f
CH		 1004/*
1005 * Read in the buffer at the given ptr and return the buffer and
1006 * the block pointer within the buffer.
1007 */
1008STATIC int
1009xfs_btree_read_buf_block(
1010 struct xfs_btree_cur *cur,
1011 union xfs_btree_ptr *ptr,
1012 int level,
1013 int flags,
1014 struct xfs_btree_block **block,
1015 struct xfs_buf **bpp)
1016{
1017 struct xfs_mount *mp = cur->bc_mp;
1018 xfs_daddr_t d;
1019 int error;
1020
1021 /* need to sort out how callers deal with failures first */
0cadda1c 1022 ASSERT(!(flags & XBF_TRYLOCK));
637aa50f
CH		 1023
1024 d = xfs_btree_ptr_to_daddr(cur, ptr);
1025 error = xfs_trans_read_buf(mp, cur->bc_tp, mp->m_ddev_targp, d,
3d3e6f64
DC		 1026 mp->m_bsize, flags, bpp,
1027 cur->bc_ops->read_verify);
637aa50f
CH		 1028 if (error)
1029 return error;
1030
5a52c2a5 1031 ASSERT(!xfs_buf_geterror(*bpp));
637aa50f
CH		 1032 xfs_btree_set_refs(cur, *bpp);
1033 *block = XFS_BUF_TO_BLOCK(*bpp);
3d3e6f64 1034 return 0;
637aa50f
CH		 1035}
1036
38bb7423
CH		 1037/*
1038 * Copy keys from one btree block to another.
1039 */
1040STATIC void
1041xfs_btree_copy_keys(
1042 struct xfs_btree_cur *cur,
1043 union xfs_btree_key *dst_key,
1044 union xfs_btree_key *src_key,
1045 int numkeys)
1046{
1047 ASSERT(numkeys >= 0);
1048 memcpy(dst_key, src_key, numkeys * cur->bc_ops->key_len);
1049}
1050
278d0ca1
CH		 1051/*
1052 * Copy records from one btree block to another.
1053 */
1054STATIC void
1055xfs_btree_copy_recs(
1056 struct xfs_btree_cur *cur,
1057 union xfs_btree_rec *dst_rec,
1058 union xfs_btree_rec *src_rec,
1059 int numrecs)
1060{
1061 ASSERT(numrecs >= 0);
1062 memcpy(dst_rec, src_rec, numrecs * cur->bc_ops->rec_len);
1063}
1064
9eaead51
CH		 1065/*
1066 * Copy block pointers from one btree block to another.
1067 */
1068STATIC void
1069xfs_btree_copy_ptrs(
1070 struct xfs_btree_cur *cur,
1071 union xfs_btree_ptr *dst_ptr,
1072 union xfs_btree_ptr *src_ptr,
1073 int numptrs)
1074{
1075 ASSERT(numptrs >= 0);
1076 memcpy(dst_ptr, src_ptr, numptrs * xfs_btree_ptr_len(cur));
1077}
1078
1079/*
1080 * Shift keys one index left/right inside a single btree block.
1081 */
1082STATIC void
1083xfs_btree_shift_keys(
1084 struct xfs_btree_cur *cur,
1085 union xfs_btree_key *key,
1086 int dir,
1087 int numkeys)
1088{
1089 char *dst_key;
1090
1091 ASSERT(numkeys >= 0);
1092 ASSERT(dir == 1 || dir == -1);
1093
1094 dst_key = (char *)key + (dir * cur->bc_ops->key_len);
1095 memmove(dst_key, key, numkeys * cur->bc_ops->key_len);
1096}
1097
1098/*
1099 * Shift records one index left/right inside a single btree block.
1100 */
1101STATIC void
1102xfs_btree_shift_recs(
1103 struct xfs_btree_cur *cur,
1104 union xfs_btree_rec *rec,
1105 int dir,
1106 int numrecs)
1107{
1108 char *dst_rec;
1109
1110 ASSERT(numrecs >= 0);
1111 ASSERT(dir == 1 || dir == -1);
1112
1113 dst_rec = (char *)rec + (dir * cur->bc_ops->rec_len);
1114 memmove(dst_rec, rec, numrecs * cur->bc_ops->rec_len);
1115}
1116
1117/*
1118 * Shift block pointers one index left/right inside a single btree block.
1119 */
1120STATIC void
1121xfs_btree_shift_ptrs(
1122 struct xfs_btree_cur *cur,
1123 union xfs_btree_ptr *ptr,
1124 int dir,
1125 int numptrs)
1126{
1127 char *dst_ptr;
1128
1129 ASSERT(numptrs >= 0);
1130 ASSERT(dir == 1 || dir == -1);
1131
1132 dst_ptr = (char *)ptr + (dir * xfs_btree_ptr_len(cur));
1133 memmove(dst_ptr, ptr, numptrs * xfs_btree_ptr_len(cur));
1134}
1135
38bb7423
CH		 1136/*
1137 * Log key values from the btree block.
1138 */
1139STATIC void
1140xfs_btree_log_keys(
1141 struct xfs_btree_cur *cur,
1142 struct xfs_buf *bp,
1143 int first,
1144 int last)
1145{
1146 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1147 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1148
1149 if (bp) {
1150 xfs_trans_log_buf(cur->bc_tp, bp,
1151 xfs_btree_key_offset(cur, first),
1152 xfs_btree_key_offset(cur, last + 1) - 1);
1153 } else {
1154 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1155 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1156 }
1157
1158 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1159}
1160
278d0ca1
CH		 1161/*
1162 * Log record values from the btree block.
1163 */
fd6bcc5b 1164void
278d0ca1
CH		 1165xfs_btree_log_recs(
1166 struct xfs_btree_cur *cur,
1167 struct xfs_buf *bp,
1168 int first,
1169 int last)
1170{
1171 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1172 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1173
1174 xfs_trans_log_buf(cur->bc_tp, bp,
1175 xfs_btree_rec_offset(cur, first),
1176 xfs_btree_rec_offset(cur, last + 1) - 1);
1177
1178 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1179}
1180
9eaead51
CH		 1181/*
1182 * Log block pointer fields from a btree block (nonleaf).
1183 */
1184STATIC void
1185xfs_btree_log_ptrs(
1186 struct xfs_btree_cur *cur, /* btree cursor */
1187 struct xfs_buf *bp, /* buffer containing btree block */
1188 int first, /* index of first pointer to log */
1189 int last) /* index of last pointer to log */
1190{
1191 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1192 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1193
1194 if (bp) {
1195 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
1196 int level = xfs_btree_get_level(block);
1197
1198 xfs_trans_log_buf(cur->bc_tp, bp,
1199 xfs_btree_ptr_offset(cur, first, level),
1200 xfs_btree_ptr_offset(cur, last + 1, level) - 1);
1201 } else {
1202 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1203 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1204 }
1205
1206 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1207}
1208
1209/*
1210 * Log fields from a btree block header.
1211 */
fd6bcc5b 1212void
9eaead51
CH		 1213xfs_btree_log_block(
1214 struct xfs_btree_cur *cur, /* btree cursor */
1215 struct xfs_buf *bp, /* buffer containing btree block */
1216 int fields) /* mask of fields: XFS_BB_... */
1217{
1218 int first; /* first byte offset logged */
1219 int last; /* last byte offset logged */
1220 static const short soffsets[] = { /* table of offsets (short) */
7cc95a82
CH		 1221 offsetof(struct xfs_btree_block, bb_magic),
1222 offsetof(struct xfs_btree_block, bb_level),
1223 offsetof(struct xfs_btree_block, bb_numrecs),
1224 offsetof(struct xfs_btree_block, bb_u.s.bb_leftsib),
1225 offsetof(struct xfs_btree_block, bb_u.s.bb_rightsib),
1226 XFS_BTREE_SBLOCK_LEN
9eaead51
CH		 1227 };
1228 static const short loffsets[] = { /* table of offsets (long) */
7cc95a82
CH		 1229 offsetof(struct xfs_btree_block, bb_magic),
1230 offsetof(struct xfs_btree_block, bb_level),
1231 offsetof(struct xfs_btree_block, bb_numrecs),
1232 offsetof(struct xfs_btree_block, bb_u.l.bb_leftsib),
1233 offsetof(struct xfs_btree_block, bb_u.l.bb_rightsib),
1234 XFS_BTREE_LBLOCK_LEN
9eaead51
CH		 1235 };
1236
1237 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1238 XFS_BTREE_TRACE_ARGBI(cur, bp, fields);
1239
1240 if (bp) {
1241 xfs_btree_offsets(fields,
1242 (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
1243 loffsets : soffsets,
1244 XFS_BB_NUM_BITS, &first, &last);
1245 xfs_trans_log_buf(cur->bc_tp, bp, first, last);
1246 } else {
1247 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1248 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1249 }
1250
1251 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1252}
1253
637aa50f
CH		 1254/*
1255 * Increment cursor by one record at the level.
1256 * For nonzero levels the leaf-ward information is untouched.
1257 */
1258int /* error */
1259xfs_btree_increment(
1260 struct xfs_btree_cur *cur,
1261 int level,
1262 int *stat) /* success/failure */
1263{
1264 struct xfs_btree_block *block;
1265 union xfs_btree_ptr ptr;
1266 struct xfs_buf *bp;
1267 int error; /* error return value */
1268 int lev;
1269
1270 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1271 XFS_BTREE_TRACE_ARGI(cur, level);
1272
1273 ASSERT(level < cur->bc_nlevels);
1274
1275 /* Read-ahead to the right at this level. */
1276 xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
1277
1278 /* Get a pointer to the btree block. */
1279 block = xfs_btree_get_block(cur, level, &bp);
1280
1281#ifdef DEBUG
1282 error = xfs_btree_check_block(cur, block, level, bp);
1283 if (error)
1284 goto error0;
1285#endif
1286
1287 /* We're done if we remain in the block after the increment. */
1288 if (++cur->bc_ptrs[level] <= xfs_btree_get_numrecs(block))
1289 goto out1;
1290
1291 /* Fail if we just went off the right edge of the tree. */
1292 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1293 if (xfs_btree_ptr_is_null(cur, &ptr))
1294 goto out0;
1295
1296 XFS_BTREE_STATS_INC(cur, increment);
1297
1298 /*
1299 * March up the tree incrementing pointers.
1300 * Stop when we don't go off the right edge of a block.
1301 */
1302 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1303 block = xfs_btree_get_block(cur, lev, &bp);
1304
1305#ifdef DEBUG
1306 error = xfs_btree_check_block(cur, block, lev, bp);
1307 if (error)
1308 goto error0;
1309#endif
1310
1311 if (++cur->bc_ptrs[lev] <= xfs_btree_get_numrecs(block))
1312 break;
1313
1314 /* Read-ahead the right block for the next loop. */
1315 xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA);
1316 }
1317
1318 /*
1319 * If we went off the root then we are either seriously
1320 * confused or have the tree root in an inode.
1321 */
1322 if (lev == cur->bc_nlevels) {
1323 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1324 goto out0;
1325 ASSERT(0);
1326 error = EFSCORRUPTED;
1327 goto error0;
1328 }
1329 ASSERT(lev < cur->bc_nlevels);
1330
1331 /*
1332 * Now walk back down the tree, fixing up the cursor's buffer
1333 * pointers and key numbers.
1334 */
1335 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1336 union xfs_btree_ptr *ptrp;
1337
1338 ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1339 error = xfs_btree_read_buf_block(cur, ptrp, --lev,
1340 0, &block, &bp);
1341 if (error)
1342 goto error0;
1343
1344 xfs_btree_setbuf(cur, lev, bp);
1345 cur->bc_ptrs[lev] = 1;
1346 }
1347out1:
1348 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1349 *stat = 1;
1350 return 0;
1351
1352out0:
1353 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1354 *stat = 0;
1355 return 0;
1356
1357error0:
1358 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1359 return error;
1360}
8df4da4a
CH		 1361
1362/*
1363 * Decrement cursor by one record at the level.
1364 * For nonzero levels the leaf-ward information is untouched.
1365 */
1366int /* error */
1367xfs_btree_decrement(
1368 struct xfs_btree_cur *cur,
1369 int level,
1370 int *stat) /* success/failure */
1371{
1372 struct xfs_btree_block *block;
1373 xfs_buf_t *bp;
1374 int error; /* error return value */
1375 int lev;
1376 union xfs_btree_ptr ptr;
1377
1378 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1379 XFS_BTREE_TRACE_ARGI(cur, level);
1380
1381 ASSERT(level < cur->bc_nlevels);
1382
1383 /* Read-ahead to the left at this level. */
1384 xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA);
1385
1386 /* We're done if we remain in the block after the decrement. */
1387 if (--cur->bc_ptrs[level] > 0)
1388 goto out1;
1389
1390 /* Get a pointer to the btree block. */
1391 block = xfs_btree_get_block(cur, level, &bp);
1392
1393#ifdef DEBUG
1394 error = xfs_btree_check_block(cur, block, level, bp);
1395 if (error)
1396 goto error0;
1397#endif
1398
1399 /* Fail if we just went off the left edge of the tree. */
1400 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
1401 if (xfs_btree_ptr_is_null(cur, &ptr))
1402 goto out0;
1403
1404 XFS_BTREE_STATS_INC(cur, decrement);
1405
1406 /*
1407 * March up the tree decrementing pointers.
1408 * Stop when we don't go off the left edge of a block.
1409 */
1410 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1411 if (--cur->bc_ptrs[lev] > 0)
1412 break;
1413 /* Read-ahead the left block for the next loop. */
1414 xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA);
1415 }
1416
1417 /*
1418 * If we went off the root then we are seriously confused.
1419 * or the root of the tree is in an inode.
1420 */
1421 if (lev == cur->bc_nlevels) {
1422 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1423 goto out0;
1424 ASSERT(0);
1425 error = EFSCORRUPTED;
1426 goto error0;
1427 }
1428 ASSERT(lev < cur->bc_nlevels);
1429
1430 /*
1431 * Now walk back down the tree, fixing up the cursor's buffer
1432 * pointers and key numbers.
1433 */
1434 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1435 union xfs_btree_ptr *ptrp;
1436
1437 ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1438 error = xfs_btree_read_buf_block(cur, ptrp, --lev,
1439 0, &block, &bp);
1440 if (error)
1441 goto error0;
1442 xfs_btree_setbuf(cur, lev, bp);
1443 cur->bc_ptrs[lev] = xfs_btree_get_numrecs(block);
1444 }
1445out1:
1446 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1447 *stat = 1;
1448 return 0;
1449
1450out0:
1451 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1452 *stat = 0;
1453 return 0;
1454
1455error0:
1456 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1457 return error;
1458}
1459
fe033cc8
CH		 1460STATIC int
1461xfs_btree_lookup_get_block(
1462 struct xfs_btree_cur *cur, /* btree cursor */
1463 int level, /* level in the btree */
1464 union xfs_btree_ptr *pp, /* ptr to btree block */
1465 struct xfs_btree_block **blkp) /* return btree block */
1466{
1467 struct xfs_buf *bp; /* buffer pointer for btree block */
1468 int error = 0;
1469
1470 /* special case the root block if in an inode */
1471 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1472 (level == cur->bc_nlevels - 1)) {
1473 *blkp = xfs_btree_get_iroot(cur);
1474 return 0;
1475 }
1476
1477 /*
1478 * If the old buffer at this level for the disk address we are
1479 * looking for re-use it.
1480 *
1481 * Otherwise throw it away and get a new one.
1482 */
1483 bp = cur->bc_bufs[level];
1484 if (bp && XFS_BUF_ADDR(bp) == xfs_btree_ptr_to_daddr(cur, pp)) {
1485 *blkp = XFS_BUF_TO_BLOCK(bp);
1486 return 0;
1487 }
1488
1489 error = xfs_btree_read_buf_block(cur, pp, level, 0, blkp, &bp);
1490 if (error)
1491 return error;
1492
1493 xfs_btree_setbuf(cur, level, bp);
1494 return 0;
1495}
1496
1497/*
1498 * Get current search key. For level 0 we don't actually have a key
1499 * structure so we make one up from the record. For all other levels
1500 * we just return the right key.
1501 */
1502STATIC union xfs_btree_key *
1503xfs_lookup_get_search_key(
1504 struct xfs_btree_cur *cur,
1505 int level,
1506 int keyno,
1507 struct xfs_btree_block *block,
1508 union xfs_btree_key *kp)
1509{
1510 if (level == 0) {
1511 cur->bc_ops->init_key_from_rec(kp,
1512 xfs_btree_rec_addr(cur, keyno, block));
1513 return kp;
1514 }
1515
1516 return xfs_btree_key_addr(cur, keyno, block);
1517}
1518
1519/*
1520 * Lookup the record. The cursor is made to point to it, based on dir.
1521 * Return 0 if can't find any such record, 1 for success.
1522 */
1523int /* error */
1524xfs_btree_lookup(
1525 struct xfs_btree_cur *cur, /* btree cursor */
1526 xfs_lookup_t dir, /* <=, ==, or >= */
1527 int *stat) /* success/failure */
1528{
1529 struct xfs_btree_block *block; /* current btree block */
1530 __int64_t diff; /* difference for the current key */
1531 int error; /* error return value */
1532 int keyno; /* current key number */
1533 int level; /* level in the btree */
1534 union xfs_btree_ptr *pp; /* ptr to btree block */
1535 union xfs_btree_ptr ptr; /* ptr to btree block */
1536
1537 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1538 XFS_BTREE_TRACE_ARGI(cur, dir);
1539
1540 XFS_BTREE_STATS_INC(cur, lookup);
1541
1542 block = NULL;
1543 keyno = 0;
1544
1545 /* initialise start pointer from cursor */
1546 cur->bc_ops->init_ptr_from_cur(cur, &ptr);
1547 pp = &ptr;
1548
1549 /*
1550 * Iterate over each level in the btree, starting at the root.
1551 * For each level above the leaves, find the key we need, based
1552 * on the lookup record, then follow the corresponding block
1553 * pointer down to the next level.
1554 */
1555 for (level = cur->bc_nlevels - 1, diff = 1; level >= 0; level--) {
1556 /* Get the block we need to do the lookup on. */
1557 error = xfs_btree_lookup_get_block(cur, level, pp, &block);
1558 if (error)
1559 goto error0;
1560
1561 if (diff == 0) {
1562 /*
1563 * If we already had a key match at a higher level, we
1564 * know we need to use the first entry in this block.
1565 */
1566 keyno = 1;
1567 } else {
1568 /* Otherwise search this block. Do a binary search. */
1569
1570 int high; /* high entry number */
1571 int low; /* low entry number */
1572
1573 /* Set low and high entry numbers, 1-based. */
1574 low = 1;
1575 high = xfs_btree_get_numrecs(block);
1576 if (!high) {
1577 /* Block is empty, must be an empty leaf. */
1578 ASSERT(level == 0 && cur->bc_nlevels == 1);
1579
1580 cur->bc_ptrs[0] = dir != XFS_LOOKUP_LE;
1581 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1582 *stat = 0;
1583 return 0;
1584 }
1585
1586 /* Binary search the block. */
1587 while (low <= high) {
1588 union xfs_btree_key key;
1589 union xfs_btree_key *kp;
1590
1591 XFS_BTREE_STATS_INC(cur, compare);
1592
1593 /* keyno is average of low and high. */
1594 keyno = (low + high) >> 1;
1595
1596 /* Get current search key */
1597 kp = xfs_lookup_get_search_key(cur, level,
1598 keyno, block, &key);
1599
1600 /*
1601 * Compute difference to get next direction:
1602 * - less than, move right
1603 * - greater than, move left
1604 * - equal, we're done
1605 */
1606 diff = cur->bc_ops->key_diff(cur, kp);
1607 if (diff < 0)
1608 low = keyno + 1;
1609 else if (diff > 0)
1610 high = keyno - 1;
1611 else
1612 break;
1613 }
1614 }
1615
1616 /*
1617 * If there are more levels, set up for the next level
1618 * by getting the block number and filling in the cursor.
1619 */
1620 if (level > 0) {
1621 /*
1622 * If we moved left, need the previous key number,
1623 * unless there isn't one.
1624 */
1625 if (diff > 0 && --keyno < 1)
1626 keyno = 1;
1627 pp = xfs_btree_ptr_addr(cur, keyno, block);
1628
1629#ifdef DEBUG
1630 error = xfs_btree_check_ptr(cur, pp, 0, level);
1631 if (error)
1632 goto error0;
1633#endif
1634 cur->bc_ptrs[level] = keyno;
1635 }
1636 }
1637
1638 /* Done with the search. See if we need to adjust the results. */
1639 if (dir != XFS_LOOKUP_LE && diff < 0) {
1640 keyno++;
1641 /*
1642 * If ge search and we went off the end of the block, but it's
1643 * not the last block, we're in the wrong block.
1644 */
1645 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1646 if (dir == XFS_LOOKUP_GE &&
1647 keyno > xfs_btree_get_numrecs(block) &&
1648 !xfs_btree_ptr_is_null(cur, &ptr)) {
1649 int i;
1650
1651 cur->bc_ptrs[0] = keyno;
1652 error = xfs_btree_increment(cur, 0, &i);
1653 if (error)
1654 goto error0;
1655 XFS_WANT_CORRUPTED_RETURN(i == 1);
1656 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1657 *stat = 1;
1658 return 0;
1659 }
1660 } else if (dir == XFS_LOOKUP_LE && diff > 0)
1661 keyno--;
1662 cur->bc_ptrs[0] = keyno;
1663
1664 /* Return if we succeeded or not. */
1665 if (keyno == 0 || keyno > xfs_btree_get_numrecs(block))
1666 *stat = 0;
1667 else if (dir != XFS_LOOKUP_EQ || diff == 0)
1668 *stat = 1;
1669 else
1670 *stat = 0;
1671 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1672 return 0;
1673
1674error0:
1675 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1676 return error;
1677}
38bb7423
CH		 1678
1679/*
1680 * Update keys at all levels from here to the root along the cursor's path.
1681 */
3cc7524c 1682STATIC int
38bb7423
CH		 1683xfs_btree_updkey(
1684 struct xfs_btree_cur *cur,
1685 union xfs_btree_key *keyp,
1686 int level)
1687{
1688 struct xfs_btree_block *block;
1689 struct xfs_buf *bp;
1690 union xfs_btree_key *kp;
1691 int ptr;
1692
1693 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1694 XFS_BTREE_TRACE_ARGIK(cur, level, keyp);
1695
1696 ASSERT(!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) || level >= 1);
1697
1698 /*
1699 * Go up the tree from this level toward the root.
1700 * At each level, update the key value to the value input.
1701 * Stop when we reach a level where the cursor isn't pointing
1702 * at the first entry in the block.
1703 */
1704 for (ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) {
1705#ifdef DEBUG
1706 int error;
1707#endif
1708 block = xfs_btree_get_block(cur, level, &bp);
1709#ifdef DEBUG
1710 error = xfs_btree_check_block(cur, block, level, bp);
1711 if (error) {
1712 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1713 return error;
1714 }
1715#endif
1716 ptr = cur->bc_ptrs[level];
1717 kp = xfs_btree_key_addr(cur, ptr, block);
1718 xfs_btree_copy_keys(cur, kp, keyp, 1);
1719 xfs_btree_log_keys(cur, bp, ptr, ptr);
1720 }
1721
1722 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1723 return 0;
1724}
278d0ca1
CH		 1725
1726/*
1727 * Update the record referred to by cur to the value in the
1728 * given record. This either works (return 0) or gets an
1729 * EFSCORRUPTED error.
1730 */
1731int
1732xfs_btree_update(
1733 struct xfs_btree_cur *cur,
1734 union xfs_btree_rec *rec)
1735{
1736 struct xfs_btree_block *block;
1737 struct xfs_buf *bp;
1738 int error;
1739 int ptr;
1740 union xfs_btree_rec *rp;
1741
1742 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1743 XFS_BTREE_TRACE_ARGR(cur, rec);
1744
1745 /* Pick up the current block. */
1746 block = xfs_btree_get_block(cur, 0, &bp);
1747
1748#ifdef DEBUG
1749 error = xfs_btree_check_block(cur, block, 0, bp);
1750 if (error)
1751 goto error0;
1752#endif
1753 /* Get the address of the rec to be updated. */
1754 ptr = cur->bc_ptrs[0];
1755 rp = xfs_btree_rec_addr(cur, ptr, block);
1756
1757 /* Fill in the new contents and log them. */
1758 xfs_btree_copy_recs(cur, rp, rec, 1);
1759 xfs_btree_log_recs(cur, bp, ptr, ptr);
1760
1761 /*
1762 * If we are tracking the last record in the tree and
1763 * we are at the far right edge of the tree, update it.
1764 */
1765 if (xfs_btree_is_lastrec(cur, block, 0)) {
1766 cur->bc_ops->update_lastrec(cur, block, rec,
1767 ptr, LASTREC_UPDATE);
1768 }
1769
1770 /* Updating first rec in leaf. Pass new key value up to our parent. */
1771 if (ptr == 1) {
1772 union xfs_btree_key key;
1773
1774 cur->bc_ops->init_key_from_rec(&key, rec);
1775 error = xfs_btree_updkey(cur, &key, 1);
1776 if (error)
1777 goto error0;
1778 }
1779
1780 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1781 return 0;
1782
1783error0:
1784 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1785 return error;
1786}
1787
687b890a
CH		 1788/*
1789 * Move 1 record left from cur/level if possible.
1790 * Update cur to reflect the new path.
1791 */
3cc7524c 1792STATIC int /* error */
687b890a
CH		 1793xfs_btree_lshift(
1794 struct xfs_btree_cur *cur,
1795 int level,
1796 int *stat) /* success/failure */
1797{
1798 union xfs_btree_key key; /* btree key */
1799 struct xfs_buf *lbp; /* left buffer pointer */
1800 struct xfs_btree_block *left; /* left btree block */
1801 int lrecs; /* left record count */
1802 struct xfs_buf *rbp; /* right buffer pointer */
1803 struct xfs_btree_block *right; /* right btree block */
1804 int rrecs; /* right record count */
1805 union xfs_btree_ptr lptr; /* left btree pointer */
1806 union xfs_btree_key *rkp = NULL; /* right btree key */
1807 union xfs_btree_ptr *rpp = NULL; /* right address pointer */
1808 union xfs_btree_rec *rrp = NULL; /* right record pointer */
1809 int error; /* error return value */
1810
1811 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1812 XFS_BTREE_TRACE_ARGI(cur, level);
1813
1814 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1815 level == cur->bc_nlevels - 1)
1816 goto out0;
1817
1818 /* Set up variables for this block as "right". */
1819 right = xfs_btree_get_block(cur, level, &rbp);
1820
1821#ifdef DEBUG
1822 error = xfs_btree_check_block(cur, right, level, rbp);
1823 if (error)
1824 goto error0;
1825#endif
1826
1827 /* If we've got no left sibling then we can't shift an entry left. */
1828 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
1829 if (xfs_btree_ptr_is_null(cur, &lptr))
1830 goto out0;
1831
1832 /*
1833 * If the cursor entry is the one that would be moved, don't
1834 * do it... it's too complicated.
1835 */
1836 if (cur->bc_ptrs[level] <= 1)
1837 goto out0;
1838
1839 /* Set up the left neighbor as "left". */
1840 error = xfs_btree_read_buf_block(cur, &lptr, level, 0, &left, &lbp);
1841 if (error)
1842 goto error0;
1843
1844 /* If it's full, it can't take another entry. */
1845 lrecs = xfs_btree_get_numrecs(left);
1846 if (lrecs == cur->bc_ops->get_maxrecs(cur, level))
1847 goto out0;
1848
1849 rrecs = xfs_btree_get_numrecs(right);
1850
1851 /*
1852 * We add one entry to the left side and remove one for the right side.
9da096fd 1853 * Account for it here, the changes will be updated on disk and logged
687b890a
CH		 1854 * later.
1855 */
1856 lrecs++;
1857 rrecs--;
1858
1859 XFS_BTREE_STATS_INC(cur, lshift);
1860 XFS_BTREE_STATS_ADD(cur, moves, 1);
1861
1862 /*
1863 * If non-leaf, copy a key and a ptr to the left block.
1864 * Log the changes to the left block.
1865 */
1866 if (level > 0) {
1867 /* It's a non-leaf. Move keys and pointers. */
1868 union xfs_btree_key *lkp; /* left btree key */
1869 union xfs_btree_ptr *lpp; /* left address pointer */
1870
1871 lkp = xfs_btree_key_addr(cur, lrecs, left);
1872 rkp = xfs_btree_key_addr(cur, 1, right);
1873
1874 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
1875 rpp = xfs_btree_ptr_addr(cur, 1, right);
1876#ifdef DEBUG
1877 error = xfs_btree_check_ptr(cur, rpp, 0, level);
1878 if (error)
1879 goto error0;
1880#endif
1881 xfs_btree_copy_keys(cur, lkp, rkp, 1);
1882 xfs_btree_copy_ptrs(cur, lpp, rpp, 1);
1883
1884 xfs_btree_log_keys(cur, lbp, lrecs, lrecs);
1885 xfs_btree_log_ptrs(cur, lbp, lrecs, lrecs);
1886
4a26e66e
CH		 1887 ASSERT(cur->bc_ops->keys_inorder(cur,
1888 xfs_btree_key_addr(cur, lrecs - 1, left), lkp));
687b890a
CH		 1889 } else {
1890 /* It's a leaf. Move records. */
1891 union xfs_btree_rec *lrp; /* left record pointer */
1892
1893 lrp = xfs_btree_rec_addr(cur, lrecs, left);
1894 rrp = xfs_btree_rec_addr(cur, 1, right);
1895
1896 xfs_btree_copy_recs(cur, lrp, rrp, 1);
1897 xfs_btree_log_recs(cur, lbp, lrecs, lrecs);
1898
4a26e66e
CH		 1899 ASSERT(cur->bc_ops->recs_inorder(cur,
1900 xfs_btree_rec_addr(cur, lrecs - 1, left), lrp));
687b890a
CH		 1901 }
1902
1903 xfs_btree_set_numrecs(left, lrecs);
1904 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
1905
1906 xfs_btree_set_numrecs(right, rrecs);
1907 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
1908
1909 /*
1910 * Slide the contents of right down one entry.
1911 */
1912 XFS_BTREE_STATS_ADD(cur, moves, rrecs - 1);
1913 if (level > 0) {
1914 /* It's a nonleaf. operate on keys and ptrs */
1915#ifdef DEBUG
1916 int i; /* loop index */
1917
1918 for (i = 0; i < rrecs; i++) {
1919 error = xfs_btree_check_ptr(cur, rpp, i + 1, level);
1920 if (error)
1921 goto error0;
1922 }
1923#endif
1924 xfs_btree_shift_keys(cur,
1925 xfs_btree_key_addr(cur, 2, right),
1926 -1, rrecs);
1927 xfs_btree_shift_ptrs(cur,
1928 xfs_btree_ptr_addr(cur, 2, right),
1929 -1, rrecs);
1930
1931 xfs_btree_log_keys(cur, rbp, 1, rrecs);
1932 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
1933 } else {
1934 /* It's a leaf. operate on records */
1935 xfs_btree_shift_recs(cur,
1936 xfs_btree_rec_addr(cur, 2, right),
1937 -1, rrecs);
1938 xfs_btree_log_recs(cur, rbp, 1, rrecs);
1939
1940 /*
1941 * If it's the first record in the block, we'll need a key
1942 * structure to pass up to the next level (updkey).
1943 */
1944 cur->bc_ops->init_key_from_rec(&key,
1945 xfs_btree_rec_addr(cur, 1, right));
1946 rkp = &key;
1947 }
1948
1949 /* Update the parent key values of right. */
1950 error = xfs_btree_updkey(cur, rkp, level + 1);
1951 if (error)
1952 goto error0;
1953
1954 /* Slide the cursor value left one. */
1955 cur->bc_ptrs[level]--;
1956
1957 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1958 *stat = 1;
1959 return 0;
1960
1961out0:
1962 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1963 *stat = 0;
1964 return 0;
1965
1966error0:
1967 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1968 return error;
1969}
1970
9eaead51
CH		 1971/*
1972 * Move 1 record right from cur/level if possible.
1973 * Update cur to reflect the new path.
1974 */
3cc7524c 1975STATIC int /* error */
9eaead51
CH		 1976xfs_btree_rshift(
1977 struct xfs_btree_cur *cur,
1978 int level,
1979 int *stat) /* success/failure */
1980{
1981 union xfs_btree_key key; /* btree key */
1982 struct xfs_buf *lbp; /* left buffer pointer */
1983 struct xfs_btree_block *left; /* left btree block */
1984 struct xfs_buf *rbp; /* right buffer pointer */
1985 struct xfs_btree_block *right; /* right btree block */
1986 struct xfs_btree_cur *tcur; /* temporary btree cursor */
1987 union xfs_btree_ptr rptr; /* right block pointer */
1988 union xfs_btree_key *rkp; /* right btree key */
1989 int rrecs; /* right record count */
1990 int lrecs; /* left record count */
1991 int error; /* error return value */
1992 int i; /* loop counter */
1993
1994 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1995 XFS_BTREE_TRACE_ARGI(cur, level);
1996
1997 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1998 (level == cur->bc_nlevels - 1))
1999 goto out0;
2000
2001 /* Set up variables for this block as "left". */
2002 left = xfs_btree_get_block(cur, level, &lbp);
2003
2004#ifdef DEBUG
2005 error = xfs_btree_check_block(cur, left, level, lbp);
2006 if (error)
2007 goto error0;
2008#endif
2009
2010 /* If we've got no right sibling then we can't shift an entry right. */
2011 xfs_btree_get_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2012 if (xfs_btree_ptr_is_null(cur, &rptr))
2013 goto out0;
2014
2015 /*
2016 * If the cursor entry is the one that would be moved, don't
2017 * do it... it's too complicated.
2018 */
2019 lrecs = xfs_btree_get_numrecs(left);
2020 if (cur->bc_ptrs[level] >= lrecs)
2021 goto out0;
2022
2023 /* Set up the right neighbor as "right". */
2024 error = xfs_btree_read_buf_block(cur, &rptr, level, 0, &right, &rbp);
2025 if (error)
2026 goto error0;
2027
2028 /* If it's full, it can't take another entry. */
2029 rrecs = xfs_btree_get_numrecs(right);
2030 if (rrecs == cur->bc_ops->get_maxrecs(cur, level))
2031 goto out0;
2032
2033 XFS_BTREE_STATS_INC(cur, rshift);
2034 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2035
2036 /*
2037 * Make a hole at the start of the right neighbor block, then
2038 * copy the last left block entry to the hole.
2039 */
2040 if (level > 0) {
2041 /* It's a nonleaf. make a hole in the keys and ptrs */
2042 union xfs_btree_key *lkp;
2043 union xfs_btree_ptr *lpp;
2044 union xfs_btree_ptr *rpp;
2045
2046 lkp = xfs_btree_key_addr(cur, lrecs, left);
2047 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2048 rkp = xfs_btree_key_addr(cur, 1, right);
2049 rpp = xfs_btree_ptr_addr(cur, 1, right);
2050
2051#ifdef DEBUG
2052 for (i = rrecs - 1; i >= 0; i--) {
2053 error = xfs_btree_check_ptr(cur, rpp, i, level);
2054 if (error)
2055 goto error0;
2056 }
2057#endif
2058
2059 xfs_btree_shift_keys(cur, rkp, 1, rrecs);
2060 xfs_btree_shift_ptrs(cur, rpp, 1, rrecs);
2061
2062#ifdef DEBUG
2063 error = xfs_btree_check_ptr(cur, lpp, 0, level);
2064 if (error)
2065 goto error0;
2066#endif
2067
2068 /* Now put the new data in, and log it. */
2069 xfs_btree_copy_keys(cur, rkp, lkp, 1);
2070 xfs_btree_copy_ptrs(cur, rpp, lpp, 1);
2071
2072 xfs_btree_log_keys(cur, rbp, 1, rrecs + 1);
2073 xfs_btree_log_ptrs(cur, rbp, 1, rrecs + 1);
2074
4a26e66e
CH		 2075 ASSERT(cur->bc_ops->keys_inorder(cur, rkp,
2076 xfs_btree_key_addr(cur, 2, right)));
9eaead51
CH		 2077 } else {
2078 /* It's a leaf. make a hole in the records */
2079 union xfs_btree_rec *lrp;
2080 union xfs_btree_rec *rrp;
2081
2082 lrp = xfs_btree_rec_addr(cur, lrecs, left);
2083 rrp = xfs_btree_rec_addr(cur, 1, right);
2084
2085 xfs_btree_shift_recs(cur, rrp, 1, rrecs);
2086
2087 /* Now put the new data in, and log it. */
2088 xfs_btree_copy_recs(cur, rrp, lrp, 1);
2089 xfs_btree_log_recs(cur, rbp, 1, rrecs + 1);
2090
2091 cur->bc_ops->init_key_from_rec(&key, rrp);
2092 rkp = &key;
2093
4a26e66e
CH		 2094 ASSERT(cur->bc_ops->recs_inorder(cur, rrp,
2095 xfs_btree_rec_addr(cur, 2, right)));
9eaead51
CH		 2096 }
2097
2098 /*
2099 * Decrement and log left's numrecs, bump and log right's numrecs.
2100 */
2101 xfs_btree_set_numrecs(left, --lrecs);
2102 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2103
2104 xfs_btree_set_numrecs(right, ++rrecs);
2105 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2106
2107 /*
2108 * Using a temporary cursor, update the parent key values of the
2109 * block on the right.
2110 */
2111 error = xfs_btree_dup_cursor(cur, &tcur);
2112 if (error)
2113 goto error0;
2114 i = xfs_btree_lastrec(tcur, level);
2115 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
2116
2117 error = xfs_btree_increment(tcur, level, &i);
2118 if (error)
2119 goto error1;
2120
2121 error = xfs_btree_updkey(tcur, rkp, level + 1);
2122 if (error)
2123 goto error1;
2124
2125 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
2126
2127 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2128 *stat = 1;
2129 return 0;
2130
2131out0:
2132 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2133 *stat = 0;
2134 return 0;
2135
2136error0:
2137 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2138 return error;
2139
2140error1:
2141 XFS_BTREE_TRACE_CURSOR(tcur, XBT_ERROR);
2142 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
2143 return error;
2144}
f5eb8e7c
CH		 2145
2146/*
2147 * Split cur/level block in half.
2148 * Return new block number and the key to its first
2149 * record (to be inserted into parent).
2150 */
3cc7524c 2151STATIC int /* error */
f5eb8e7c
CH		 2152xfs_btree_split(
2153 struct xfs_btree_cur *cur,
2154 int level,
2155 union xfs_btree_ptr *ptrp,
2156 union xfs_btree_key *key,
2157 struct xfs_btree_cur **curp,
2158 int *stat) /* success/failure */
2159{
2160 union xfs_btree_ptr lptr; /* left sibling block ptr */
2161 struct xfs_buf *lbp; /* left buffer pointer */
2162 struct xfs_btree_block *left; /* left btree block */
2163 union xfs_btree_ptr rptr; /* right sibling block ptr */
2164 struct xfs_buf *rbp; /* right buffer pointer */
2165 struct xfs_btree_block *right; /* right btree block */
2166 union xfs_btree_ptr rrptr; /* right-right sibling ptr */
2167 struct xfs_buf *rrbp; /* right-right buffer pointer */
2168 struct xfs_btree_block *rrblock; /* right-right btree block */
2169 int lrecs;
2170 int rrecs;
2171 int src_index;
2172 int error; /* error return value */
2173#ifdef DEBUG
2174 int i;
2175#endif
2176
2177 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2178 XFS_BTREE_TRACE_ARGIPK(cur, level, *ptrp, key);
2179
2180 XFS_BTREE_STATS_INC(cur, split);
2181
2182 /* Set up left block (current one). */
2183 left = xfs_btree_get_block(cur, level, &lbp);
2184
2185#ifdef DEBUG
2186 error = xfs_btree_check_block(cur, left, level, lbp);
2187 if (error)
2188 goto error0;
2189#endif
2190
2191 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2192
2193 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2194 error = cur->bc_ops->alloc_block(cur, &lptr, &rptr, 1, stat);
2195 if (error)
2196 goto error0;
2197 if (*stat == 0)
2198 goto out0;
2199 XFS_BTREE_STATS_INC(cur, alloc);
2200
2201 /* Set up the new block as "right". */
2202 error = xfs_btree_get_buf_block(cur, &rptr, 0, &right, &rbp);
2203 if (error)
2204 goto error0;
2205
2206 /* Fill in the btree header for the new right block. */
b64f3a39 2207 xfs_btree_init_block_cur(cur, xfs_btree_get_level(left), 0, rbp);
f5eb8e7c
CH		 2208
2209 /*
2210 * Split the entries between the old and the new block evenly.
2211 * Make sure that if there's an odd number of entries now, that
2212 * each new block will have the same number of entries.
2213 */
2214 lrecs = xfs_btree_get_numrecs(left);
2215 rrecs = lrecs / 2;
2216 if ((lrecs & 1) && cur->bc_ptrs[level] <= rrecs + 1)
2217 rrecs++;
2218 src_index = (lrecs - rrecs + 1);
2219
2220 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2221
2222 /*
2223 * Copy btree block entries from the left block over to the
2224 * new block, the right. Update the right block and log the
2225 * changes.
2226 */
2227 if (level > 0) {
2228 /* It's a non-leaf. Move keys and pointers. */
2229 union xfs_btree_key *lkp; /* left btree key */
2230 union xfs_btree_ptr *lpp; /* left address pointer */
2231 union xfs_btree_key *rkp; /* right btree key */
2232 union xfs_btree_ptr *rpp; /* right address pointer */
2233
2234 lkp = xfs_btree_key_addr(cur, src_index, left);
2235 lpp = xfs_btree_ptr_addr(cur, src_index, left);
2236 rkp = xfs_btree_key_addr(cur, 1, right);
2237 rpp = xfs_btree_ptr_addr(cur, 1, right);
2238
2239#ifdef DEBUG
2240 for (i = src_index; i < rrecs; i++) {
2241 error = xfs_btree_check_ptr(cur, lpp, i, level);
2242 if (error)
2243 goto error0;
2244 }
2245#endif
2246
2247 xfs_btree_copy_keys(cur, rkp, lkp, rrecs);
2248 xfs_btree_copy_ptrs(cur, rpp, lpp, rrecs);
2249
2250 xfs_btree_log_keys(cur, rbp, 1, rrecs);
2251 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2252
2253 /* Grab the keys to the entries moved to the right block */
2254 xfs_btree_copy_keys(cur, key, rkp, 1);
2255 } else {
2256 /* It's a leaf. Move records. */
2257 union xfs_btree_rec *lrp; /* left record pointer */
2258 union xfs_btree_rec *rrp; /* right record pointer */
2259
2260 lrp = xfs_btree_rec_addr(cur, src_index, left);
2261 rrp = xfs_btree_rec_addr(cur, 1, right);
2262
2263 xfs_btree_copy_recs(cur, rrp, lrp, rrecs);
2264 xfs_btree_log_recs(cur, rbp, 1, rrecs);
2265
2266 cur->bc_ops->init_key_from_rec(key,
2267 xfs_btree_rec_addr(cur, 1, right));
2268 }
2269
2270
2271 /*
2272 * Find the left block number by looking in the buffer.
2273 * Adjust numrecs, sibling pointers.
2274 */
2275 xfs_btree_get_sibling(cur, left, &rrptr, XFS_BB_RIGHTSIB);
2276 xfs_btree_set_sibling(cur, right, &rrptr, XFS_BB_RIGHTSIB);
2277 xfs_btree_set_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2278 xfs_btree_set_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2279
2280 lrecs -= rrecs;
2281 xfs_btree_set_numrecs(left, lrecs);
2282 xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs);
2283
2284 xfs_btree_log_block(cur, rbp, XFS_BB_ALL_BITS);
2285 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
2286
2287 /*
2288 * If there's a block to the new block's right, make that block
2289 * point back to right instead of to left.
2290 */
2291 if (!xfs_btree_ptr_is_null(cur, &rrptr)) {
2292 error = xfs_btree_read_buf_block(cur, &rrptr, level,
2293 0, &rrblock, &rrbp);
2294 if (error)
2295 goto error0;
2296 xfs_btree_set_sibling(cur, rrblock, &rptr, XFS_BB_LEFTSIB);
2297 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
2298 }
2299 /*
2300 * If the cursor is really in the right block, move it there.
2301 * If it's just pointing past the last entry in left, then we'll
2302 * insert there, so don't change anything in that case.
2303 */
2304 if (cur->bc_ptrs[level] > lrecs + 1) {
2305 xfs_btree_setbuf(cur, level, rbp);
2306 cur->bc_ptrs[level] -= lrecs;
2307 }
2308 /*
2309 * If there are more levels, we'll need another cursor which refers
2310 * the right block, no matter where this cursor was.
2311 */
2312 if (level + 1 < cur->bc_nlevels) {
2313 error = xfs_btree_dup_cursor(cur, curp);
2314 if (error)
2315 goto error0;
2316 (*curp)->bc_ptrs[level + 1]++;
2317 }
2318 *ptrp = rptr;
2319 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2320 *stat = 1;
2321 return 0;
2322out0:
2323 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2324 *stat = 0;
2325 return 0;
2326
2327error0:
2328 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2329 return error;
2330}
344207ce 2331
ea77b0a6
CH		 2332/*
2333 * Copy the old inode root contents into a real block and make the
2334 * broot point to it.
2335 */
2336int /* error */
2337xfs_btree_new_iroot(
2338 struct xfs_btree_cur *cur, /* btree cursor */
2339 int *logflags, /* logging flags for inode */
2340 int *stat) /* return status - 0 fail */
2341{
2342 struct xfs_buf *cbp; /* buffer for cblock */
2343 struct xfs_btree_block *block; /* btree block */
2344 struct xfs_btree_block *cblock; /* child btree block */
2345 union xfs_btree_key *ckp; /* child key pointer */
2346 union xfs_btree_ptr *cpp; /* child ptr pointer */
2347 union xfs_btree_key *kp; /* pointer to btree key */
2348 union xfs_btree_ptr *pp; /* pointer to block addr */
2349 union xfs_btree_ptr nptr; /* new block addr */
2350 int level; /* btree level */
2351 int error; /* error return code */
2352#ifdef DEBUG
2353 int i; /* loop counter */
2354#endif
2355
2356 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2357 XFS_BTREE_STATS_INC(cur, newroot);
2358
2359 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
2360
2361 level = cur->bc_nlevels - 1;
2362
2363 block = xfs_btree_get_iroot(cur);
2364 pp = xfs_btree_ptr_addr(cur, 1, block);
2365
2366 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2367 error = cur->bc_ops->alloc_block(cur, pp, &nptr, 1, stat);
2368 if (error)
2369 goto error0;
2370 if (*stat == 0) {
2371 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2372 return 0;
2373 }
2374 XFS_BTREE_STATS_INC(cur, alloc);
2375
2376 /* Copy the root into a real block. */
2377 error = xfs_btree_get_buf_block(cur, &nptr, 0, &cblock, &cbp);
2378 if (error)
2379 goto error0;
2380
2381 memcpy(cblock, block, xfs_btree_block_len(cur));
2382
2383 be16_add_cpu(&block->bb_level, 1);
2384 xfs_btree_set_numrecs(block, 1);
2385 cur->bc_nlevels++;
2386 cur->bc_ptrs[level + 1] = 1;
2387
2388 kp = xfs_btree_key_addr(cur, 1, block);
2389 ckp = xfs_btree_key_addr(cur, 1, cblock);
2390 xfs_btree_copy_keys(cur, ckp, kp, xfs_btree_get_numrecs(cblock));
2391
2392 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
2393#ifdef DEBUG
2394 for (i = 0; i < be16_to_cpu(cblock->bb_numrecs); i++) {
2395 error = xfs_btree_check_ptr(cur, pp, i, level);
2396 if (error)
2397 goto error0;
2398 }
2399#endif
2400 xfs_btree_copy_ptrs(cur, cpp, pp, xfs_btree_get_numrecs(cblock));
2401
2402#ifdef DEBUG
2403 error = xfs_btree_check_ptr(cur, &nptr, 0, level);
2404 if (error)
2405 goto error0;
2406#endif
2407 xfs_btree_copy_ptrs(cur, pp, &nptr, 1);
2408
2409 xfs_iroot_realloc(cur->bc_private.b.ip,
2410 1 - xfs_btree_get_numrecs(cblock),
2411 cur->bc_private.b.whichfork);
2412
2413 xfs_btree_setbuf(cur, level, cbp);
2414
2415 /*
2416 * Do all this logging at the end so that
2417 * the root is at the right level.
2418 */
2419 xfs_btree_log_block(cur, cbp, XFS_BB_ALL_BITS);
2420 xfs_btree_log_keys(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
2421 xfs_btree_log_ptrs(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
2422
2423 *logflags |=
9d87c319 2424 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork);
ea77b0a6
CH		 2425 *stat = 1;
2426 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2427 return 0;
2428error0:
2429 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2430 return error;
2431}
2432
344207ce
CH		 2433/*
2434 * Allocate a new root block, fill it in.
2435 */
3cc7524c 2436STATIC int /* error */
344207ce
CH		 2437xfs_btree_new_root(
2438 struct xfs_btree_cur *cur, /* btree cursor */
2439 int *stat) /* success/failure */
2440{
2441 struct xfs_btree_block *block; /* one half of the old root block */
2442 struct xfs_buf *bp; /* buffer containing block */
2443 int error; /* error return value */
2444 struct xfs_buf *lbp; /* left buffer pointer */
2445 struct xfs_btree_block *left; /* left btree block */
2446 struct xfs_buf *nbp; /* new (root) buffer */
2447 struct xfs_btree_block *new; /* new (root) btree block */
2448 int nptr; /* new value for key index, 1 or 2 */
2449 struct xfs_buf *rbp; /* right buffer pointer */
2450 struct xfs_btree_block *right; /* right btree block */
2451 union xfs_btree_ptr rptr;
2452 union xfs_btree_ptr lptr;
2453
2454 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2455 XFS_BTREE_STATS_INC(cur, newroot);
2456
2457 /* initialise our start point from the cursor */
2458 cur->bc_ops->init_ptr_from_cur(cur, &rptr);
2459
2460 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2461 error = cur->bc_ops->alloc_block(cur, &rptr, &lptr, 1, stat);
2462 if (error)
2463 goto error0;
2464 if (*stat == 0)
2465 goto out0;
2466 XFS_BTREE_STATS_INC(cur, alloc);
2467
2468 /* Set up the new block. */
2469 error = xfs_btree_get_buf_block(cur, &lptr, 0, &new, &nbp);
2470 if (error)
2471 goto error0;
2472
2473 /* Set the root in the holding structure increasing the level by 1. */
2474 cur->bc_ops->set_root(cur, &lptr, 1);
2475
2476 /*
2477 * At the previous root level there are now two blocks: the old root,
2478 * and the new block generated when it was split. We don't know which
2479 * one the cursor is pointing at, so we set up variables "left" and
2480 * "right" for each case.
2481 */
2482 block = xfs_btree_get_block(cur, cur->bc_nlevels - 1, &bp);
2483
2484#ifdef DEBUG
2485 error = xfs_btree_check_block(cur, block, cur->bc_nlevels - 1, bp);
2486 if (error)
2487 goto error0;
2488#endif
2489
2490 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
2491 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
2492 /* Our block is left, pick up the right block. */
2493 lbp = bp;
2494 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2495 left = block;
2496 error = xfs_btree_read_buf_block(cur, &rptr,
2497 cur->bc_nlevels - 1, 0, &right, &rbp);
2498 if (error)
2499 goto error0;
2500 bp = rbp;
2501 nptr = 1;
2502 } else {
2503 /* Our block is right, pick up the left block. */
2504 rbp = bp;
2505 xfs_btree_buf_to_ptr(cur, rbp, &rptr);
2506 right = block;
2507 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2508 error = xfs_btree_read_buf_block(cur, &lptr,
2509 cur->bc_nlevels - 1, 0, &left, &lbp);
2510 if (error)
2511 goto error0;
2512 bp = lbp;
2513 nptr = 2;
2514 }
2515 /* Fill in the new block's btree header and log it. */
b64f3a39 2516 xfs_btree_init_block_cur(cur, cur->bc_nlevels, 2, nbp);
344207ce
CH		 2517 xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS);
2518 ASSERT(!xfs_btree_ptr_is_null(cur, &lptr) &&
2519 !xfs_btree_ptr_is_null(cur, &rptr));
2520
2521 /* Fill in the key data in the new root. */
2522 if (xfs_btree_get_level(left) > 0) {
2523 xfs_btree_copy_keys(cur,
2524 xfs_btree_key_addr(cur, 1, new),
2525 xfs_btree_key_addr(cur, 1, left), 1);
2526 xfs_btree_copy_keys(cur,
2527 xfs_btree_key_addr(cur, 2, new),
2528 xfs_btree_key_addr(cur, 1, right), 1);
2529 } else {
2530 cur->bc_ops->init_key_from_rec(
2531 xfs_btree_key_addr(cur, 1, new),
2532 xfs_btree_rec_addr(cur, 1, left));
2533 cur->bc_ops->init_key_from_rec(
2534 xfs_btree_key_addr(cur, 2, new),
2535 xfs_btree_rec_addr(cur, 1, right));
2536 }
2537 xfs_btree_log_keys(cur, nbp, 1, 2);
2538
2539 /* Fill in the pointer data in the new root. */
2540 xfs_btree_copy_ptrs(cur,
2541 xfs_btree_ptr_addr(cur, 1, new), &lptr, 1);
2542 xfs_btree_copy_ptrs(cur,
2543 xfs_btree_ptr_addr(cur, 2, new), &rptr, 1);
2544 xfs_btree_log_ptrs(cur, nbp, 1, 2);
2545
2546 /* Fix up the cursor. */
2547 xfs_btree_setbuf(cur, cur->bc_nlevels, nbp);
2548 cur->bc_ptrs[cur->bc_nlevels] = nptr;
2549 cur->bc_nlevels++;
2550 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2551 *stat = 1;
2552 return 0;
2553error0:
2554 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2555 return error;
2556out0:
2557 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2558 *stat = 0;
2559 return 0;
2560}
4b22a571
CH		 2561
2562STATIC int
2563xfs_btree_make_block_unfull(
2564 struct xfs_btree_cur *cur, /* btree cursor */
2565 int level, /* btree level */
2566 int numrecs,/* # of recs in block */
2567 int *oindex,/* old tree index */
2568 int *index, /* new tree index */
2569 union xfs_btree_ptr *nptr, /* new btree ptr */
2570 struct xfs_btree_cur **ncur, /* new btree cursor */
2571 union xfs_btree_rec *nrec, /* new record */
2572 int *stat)
2573{
2574 union xfs_btree_key key; /* new btree key value */
2575 int error = 0;
2576
2577 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2578 level == cur->bc_nlevels - 1) {
2579 struct xfs_inode *ip = cur->bc_private.b.ip;
2580
2581 if (numrecs < cur->bc_ops->get_dmaxrecs(cur, level)) {
2582 /* A root block that can be made bigger. */
2583
2584 xfs_iroot_realloc(ip, 1, cur->bc_private.b.whichfork);
2585 } else {
2586 /* A root block that needs replacing */
2587 int logflags = 0;
2588
2589 error = xfs_btree_new_iroot(cur, &logflags, stat);
2590 if (error || *stat == 0)
2591 return error;
2592
2593 xfs_trans_log_inode(cur->bc_tp, ip, logflags);
2594 }
2595
2596 return 0;
2597 }
2598
2599 /* First, try shifting an entry to the right neighbor. */
2600 error = xfs_btree_rshift(cur, level, stat);
2601 if (error || *stat)
2602 return error;
2603
2604 /* Next, try shifting an entry to the left neighbor. */
2605 error = xfs_btree_lshift(cur, level, stat);
2606 if (error)
2607 return error;
2608
2609 if (*stat) {
2610 *oindex = *index = cur->bc_ptrs[level];
2611 return 0;
2612 }
2613
2614 /*
2615 * Next, try splitting the current block in half.
2616 *
2617 * If this works we have to re-set our variables because we
2618 * could be in a different block now.
2619 */
2620 error = xfs_btree_split(cur, level, nptr, &key, ncur, stat);
2621 if (error || *stat == 0)
2622 return error;
2623
2624
2625 *index = cur->bc_ptrs[level];
2626 cur->bc_ops->init_rec_from_key(&key, nrec);
2627 return 0;
2628}
2629
2630/*
2631 * Insert one record/level. Return information to the caller
2632 * allowing the next level up to proceed if necessary.
2633 */
2634STATIC int
2635xfs_btree_insrec(
2636 struct xfs_btree_cur *cur, /* btree cursor */
2637 int level, /* level to insert record at */
2638 union xfs_btree_ptr *ptrp, /* i/o: block number inserted */
2639 union xfs_btree_rec *recp, /* i/o: record data inserted */
2640 struct xfs_btree_cur **curp, /* output: new cursor replacing cur */
2641 int *stat) /* success/failure */
2642{
2643 struct xfs_btree_block *block; /* btree block */
2644 struct xfs_buf *bp; /* buffer for block */
2645 union xfs_btree_key key; /* btree key */
2646 union xfs_btree_ptr nptr; /* new block ptr */
2647 struct xfs_btree_cur *ncur; /* new btree cursor */
2648 union xfs_btree_rec nrec; /* new record count */
2649 int optr; /* old key/record index */
2650 int ptr; /* key/record index */
2651 int numrecs;/* number of records */
2652 int error; /* error return value */
2653#ifdef DEBUG
2654 int i;
2655#endif
2656
2657 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2658 XFS_BTREE_TRACE_ARGIPR(cur, level, *ptrp, recp);
2659
2660 ncur = NULL;
2661
2662 /*
2663 * If we have an external root pointer, and we've made it to the
2664 * root level, allocate a new root block and we're done.
2665 */
2666 if (!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2667 (level >= cur->bc_nlevels)) {
2668 error = xfs_btree_new_root(cur, stat);
2669 xfs_btree_set_ptr_null(cur, ptrp);
2670
2671 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2672 return error;
2673 }
2674
2675 /* If we're off the left edge, return failure. */
2676 ptr = cur->bc_ptrs[level];
2677 if (ptr == 0) {
2678 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2679 *stat = 0;
2680 return 0;
2681 }
2682
2683 /* Make a key out of the record data to be inserted, and save it. */
2684 cur->bc_ops->init_key_from_rec(&key, recp);
2685
2686 optr = ptr;
2687
2688 XFS_BTREE_STATS_INC(cur, insrec);
2689
2690 /* Get pointers to the btree buffer and block. */
2691 block = xfs_btree_get_block(cur, level, &bp);
2692 numrecs = xfs_btree_get_numrecs(block);
2693
2694#ifdef DEBUG
2695 error = xfs_btree_check_block(cur, block, level, bp);
2696 if (error)
2697 goto error0;
2698
2699 /* Check that the new entry is being inserted in the right place. */
2700 if (ptr <= numrecs) {
2701 if (level == 0) {
4a26e66e
CH		 2702 ASSERT(cur->bc_ops->recs_inorder(cur, recp,
2703 xfs_btree_rec_addr(cur, ptr, block)));
4b22a571 2704 } else {
4a26e66e
CH		 2705 ASSERT(cur->bc_ops->keys_inorder(cur, &key,
2706 xfs_btree_key_addr(cur, ptr, block)));
4b22a571
CH		 2707 }
2708 }
2709#endif
2710
2711 /*
2712 * If the block is full, we can't insert the new entry until we
2713 * make the block un-full.
2714 */
2715 xfs_btree_set_ptr_null(cur, &nptr);
2716 if (numrecs == cur->bc_ops->get_maxrecs(cur, level)) {
2717 error = xfs_btree_make_block_unfull(cur, level, numrecs,
2718 &optr, &ptr, &nptr, &ncur, &nrec, stat);
2719 if (error || *stat == 0)
2720 goto error0;
2721 }
2722
2723 /*
2724 * The current block may have changed if the block was
2725 * previously full and we have just made space in it.
2726 */
2727 block = xfs_btree_get_block(cur, level, &bp);
2728 numrecs = xfs_btree_get_numrecs(block);
2729
2730#ifdef DEBUG
2731 error = xfs_btree_check_block(cur, block, level, bp);
2732 if (error)
2733 return error;
2734#endif
2735
2736 /*
2737 * At this point we know there's room for our new entry in the block
2738 * we're pointing at.
2739 */
2740 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr + 1);
2741
2742 if (level > 0) {
2743 /* It's a nonleaf. make a hole in the keys and ptrs */
2744 union xfs_btree_key *kp;
2745 union xfs_btree_ptr *pp;
2746
2747 kp = xfs_btree_key_addr(cur, ptr, block);
2748 pp = xfs_btree_ptr_addr(cur, ptr, block);
2749
2750#ifdef DEBUG
2751 for (i = numrecs - ptr; i >= 0; i--) {
2752 error = xfs_btree_check_ptr(cur, pp, i, level);
2753 if (error)
2754 return error;
2755 }
2756#endif
2757
2758 xfs_btree_shift_keys(cur, kp, 1, numrecs - ptr + 1);
2759 xfs_btree_shift_ptrs(cur, pp, 1, numrecs - ptr + 1);
2760
2761#ifdef DEBUG
2762 error = xfs_btree_check_ptr(cur, ptrp, 0, level);
2763 if (error)
2764 goto error0;
2765#endif
2766
2767 /* Now put the new data in, bump numrecs and log it. */
2768 xfs_btree_copy_keys(cur, kp, &key, 1);
2769 xfs_btree_copy_ptrs(cur, pp, ptrp, 1);
2770 numrecs++;
2771 xfs_btree_set_numrecs(block, numrecs);
2772 xfs_btree_log_ptrs(cur, bp, ptr, numrecs);
2773 xfs_btree_log_keys(cur, bp, ptr, numrecs);
2774#ifdef DEBUG
2775 if (ptr < numrecs) {
4a26e66e
CH		 2776 ASSERT(cur->bc_ops->keys_inorder(cur, kp,
2777 xfs_btree_key_addr(cur, ptr + 1, block)));
4b22a571
CH		 2778 }
2779#endif
2780 } else {
2781 /* It's a leaf. make a hole in the records */
2782 union xfs_btree_rec *rp;
2783
2784 rp = xfs_btree_rec_addr(cur, ptr, block);
2785
2786 xfs_btree_shift_recs(cur, rp, 1, numrecs - ptr + 1);
2787
2788 /* Now put the new data in, bump numrecs and log it. */
2789 xfs_btree_copy_recs(cur, rp, recp, 1);
2790 xfs_btree_set_numrecs(block, ++numrecs);
2791 xfs_btree_log_recs(cur, bp, ptr, numrecs);
2792#ifdef DEBUG
2793 if (ptr < numrecs) {
4a26e66e
CH		 2794 ASSERT(cur->bc_ops->recs_inorder(cur, rp,
2795 xfs_btree_rec_addr(cur, ptr + 1, block)));
4b22a571
CH		 2796 }
2797#endif
2798 }
2799
2800 /* Log the new number of records in the btree header. */
2801 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
2802
2803 /* If we inserted at the start of a block, update the parents' keys. */
2804 if (optr == 1) {
2805 error = xfs_btree_updkey(cur, &key, level + 1);
2806 if (error)
2807 goto error0;
2808 }
2809
2810 /*
2811 * If we are tracking the last record in the tree and
2812 * we are at the far right edge of the tree, update it.
2813 */
2814 if (xfs_btree_is_lastrec(cur, block, level)) {
2815 cur->bc_ops->update_lastrec(cur, block, recp,
2816 ptr, LASTREC_INSREC);
2817 }
2818
2819 /*
2820 * Return the new block number, if any.
2821 * If there is one, give back a record value and a cursor too.
2822 */
2823 *ptrp = nptr;
2824 if (!xfs_btree_ptr_is_null(cur, &nptr)) {
2825 *recp = nrec;
2826 *curp = ncur;
2827 }
2828
2829 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2830 *stat = 1;
2831 return 0;
2832
2833error0:
2834 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2835 return error;
2836}
2837
2838/*
2839 * Insert the record at the point referenced by cur.
2840 *
2841 * A multi-level split of the tree on insert will invalidate the original
2842 * cursor. All callers of this function should assume that the cursor is
2843 * no longer valid and revalidate it.
2844 */
2845int
2846xfs_btree_insert(
2847 struct xfs_btree_cur *cur,
2848 int *stat)
2849{
2850 int error; /* error return value */
2851 int i; /* result value, 0 for failure */
2852 int level; /* current level number in btree */
2853 union xfs_btree_ptr nptr; /* new block number (split result) */
2854 struct xfs_btree_cur *ncur; /* new cursor (split result) */
2855 struct xfs_btree_cur *pcur; /* previous level's cursor */
2856 union xfs_btree_rec rec; /* record to insert */
2857
2858 level = 0;
2859 ncur = NULL;
2860 pcur = cur;
2861
2862 xfs_btree_set_ptr_null(cur, &nptr);
2863 cur->bc_ops->init_rec_from_cur(cur, &rec);
2864
2865 /*
2866 * Loop going up the tree, starting at the leaf level.
2867 * Stop when we don't get a split block, that must mean that
2868 * the insert is finished with this level.
2869 */
2870 do {
2871 /*
2872 * Insert nrec/nptr into this level of the tree.
2873 * Note if we fail, nptr will be null.
2874 */
2875 error = xfs_btree_insrec(pcur, level, &nptr, &rec, &ncur, &i);
2876 if (error) {
2877 if (pcur != cur)
2878 xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR);
2879 goto error0;
2880 }
2881
2882 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
2883 level++;
2884
2885 /*
2886 * See if the cursor we just used is trash.
2887 * Can't trash the caller's cursor, but otherwise we should
2888 * if ncur is a new cursor or we're about to be done.
2889 */
2890 if (pcur != cur &&
2891 (ncur || xfs_btree_ptr_is_null(cur, &nptr))) {
2892 /* Save the state from the cursor before we trash it */
2893 if (cur->bc_ops->update_cursor)
2894 cur->bc_ops->update_cursor(pcur, cur);
2895 cur->bc_nlevels = pcur->bc_nlevels;
2896 xfs_btree_del_cursor(pcur, XFS_BTREE_NOERROR);
2897 }
2898 /* If we got a new cursor, switch to it. */
2899 if (ncur) {
2900 pcur = ncur;
2901 ncur = NULL;
2902 }
2903 } while (!xfs_btree_ptr_is_null(cur, &nptr));
2904
2905 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2906 *stat = i;
2907 return 0;
2908error0:
2909 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2910 return error;
2911}
d4b3a4b7
CH		 2912
2913/*
2914 * Try to merge a non-leaf block back into the inode root.
2915 *
2916 * Note: the killroot names comes from the fact that we're effectively
2917 * killing the old root block. But because we can't just delete the
2918 * inode we have to copy the single block it was pointing to into the
2919 * inode.
2920 */
d96f8f89 2921STATIC int
d4b3a4b7
CH		 2922xfs_btree_kill_iroot(
2923 struct xfs_btree_cur *cur)
2924{
2925 int whichfork = cur->bc_private.b.whichfork;
2926 struct xfs_inode *ip = cur->bc_private.b.ip;
2927 struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork);
2928 struct xfs_btree_block *block;
2929 struct xfs_btree_block *cblock;
2930 union xfs_btree_key *kp;
2931 union xfs_btree_key *ckp;
2932 union xfs_btree_ptr *pp;
2933 union xfs_btree_ptr *cpp;
2934 struct xfs_buf *cbp;
2935 int level;
2936 int index;
2937 int numrecs;
2938#ifdef DEBUG
2939 union xfs_btree_ptr ptr;
2940 int i;
2941#endif
2942
2943 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2944
2945 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
2946 ASSERT(cur->bc_nlevels > 1);
2947
2948 /*
2949 * Don't deal with the root block needs to be a leaf case.
2950 * We're just going to turn the thing back into extents anyway.
2951 */
2952 level = cur->bc_nlevels - 1;
2953 if (level == 1)
2954 goto out0;
2955
2956 /*
2957 * Give up if the root has multiple children.
2958 */
2959 block = xfs_btree_get_iroot(cur);
2960 if (xfs_btree_get_numrecs(block) != 1)
2961 goto out0;
2962
2963 cblock = xfs_btree_get_block(cur, level - 1, &cbp);
2964 numrecs = xfs_btree_get_numrecs(cblock);
2965
2966 /*
2967 * Only do this if the next level will fit.
2968 * Then the data must be copied up to the inode,
2969 * instead of freeing the root you free the next level.
2970 */
2971 if (numrecs > cur->bc_ops->get_dmaxrecs(cur, level))
2972 goto out0;
2973
2974 XFS_BTREE_STATS_INC(cur, killroot);
2975
2976#ifdef DEBUG
2977 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
2978 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
2979 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
2980 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
2981#endif
2982
2983 index = numrecs - cur->bc_ops->get_maxrecs(cur, level);
2984 if (index) {
2985 xfs_iroot_realloc(cur->bc_private.b.ip, index,
2986 cur->bc_private.b.whichfork);
7cc95a82 2987 block = ifp->if_broot;
d4b3a4b7
CH		 2988 }
2989
2990 be16_add_cpu(&block->bb_numrecs, index);
2991 ASSERT(block->bb_numrecs == cblock->bb_numrecs);
2992
2993 kp = xfs_btree_key_addr(cur, 1, block);
2994 ckp = xfs_btree_key_addr(cur, 1, cblock);
2995 xfs_btree_copy_keys(cur, kp, ckp, numrecs);
2996
2997 pp = xfs_btree_ptr_addr(cur, 1, block);
2998 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
2999#ifdef DEBUG
3000 for (i = 0; i < numrecs; i++) {
3001 int error;
3002
3003 error = xfs_btree_check_ptr(cur, cpp, i, level - 1);
3004 if (error) {
3005 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3006 return error;
3007 }
3008 }
3009#endif
3010 xfs_btree_copy_ptrs(cur, pp, cpp, numrecs);
3011
3012 cur->bc_ops->free_block(cur, cbp);
3013 XFS_BTREE_STATS_INC(cur, free);
3014
3015 cur->bc_bufs[level - 1] = NULL;
3016 be16_add_cpu(&block->bb_level, -1);
3017 xfs_trans_log_inode(cur->bc_tp, ip,
9d87c319 3018 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork));
d4b3a4b7
CH		 3019 cur->bc_nlevels--;
3020out0:
3021 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3022 return 0;
3023}
91cca5df 3024
c0e59e1a
CH		 3025/*
3026 * Kill the current root node, and replace it with it's only child node.
3027 */
3028STATIC int
3029xfs_btree_kill_root(
3030 struct xfs_btree_cur *cur,
3031 struct xfs_buf *bp,
3032 int level,
3033 union xfs_btree_ptr *newroot)
3034{
3035 int error;
3036
3037 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3038 XFS_BTREE_STATS_INC(cur, killroot);
3039
3040 /*
3041 * Update the root pointer, decreasing the level by 1 and then
3042 * free the old root.
3043 */
3044 cur->bc_ops->set_root(cur, newroot, -1);
3045
3046 error = cur->bc_ops->free_block(cur, bp);
3047 if (error) {
3048 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3049 return error;
3050 }
3051
3052 XFS_BTREE_STATS_INC(cur, free);
3053
3054 cur->bc_bufs[level] = NULL;
3055 cur->bc_ra[level] = 0;
3056 cur->bc_nlevels--;
3057
3058 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3059 return 0;
3060}
3061
91cca5df
CH		 3062STATIC int
3063xfs_btree_dec_cursor(
3064 struct xfs_btree_cur *cur,
3065 int level,
3066 int *stat)
3067{
3068 int error;
3069 int i;
3070
3071 if (level > 0) {
3072 error = xfs_btree_decrement(cur, level, &i);
3073 if (error)
3074 return error;
3075 }
3076
3077 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3078 *stat = 1;
3079 return 0;
3080}
3081
3082/*
3083 * Single level of the btree record deletion routine.
3084 * Delete record pointed to by cur/level.
3085 * Remove the record from its block then rebalance the tree.
3086 * Return 0 for error, 1 for done, 2 to go on to the next level.
3087 */
3088STATIC int /* error */
3089xfs_btree_delrec(
3090 struct xfs_btree_cur *cur, /* btree cursor */
3091 int level, /* level removing record from */
3092 int *stat) /* fail/done/go-on */
3093{
3094 struct xfs_btree_block *block; /* btree block */
3095 union xfs_btree_ptr cptr; /* current block ptr */
3096 struct xfs_buf *bp; /* buffer for block */
3097 int error; /* error return value */
3098 int i; /* loop counter */
3099 union xfs_btree_key key; /* storage for keyp */
3100 union xfs_btree_key *keyp = &key; /* passed to the next level */
3101 union xfs_btree_ptr lptr; /* left sibling block ptr */
3102 struct xfs_buf *lbp; /* left buffer pointer */
3103 struct xfs_btree_block *left; /* left btree block */
3104 int lrecs = 0; /* left record count */
3105 int ptr; /* key/record index */
3106 union xfs_btree_ptr rptr; /* right sibling block ptr */
3107 struct xfs_buf *rbp; /* right buffer pointer */
3108 struct xfs_btree_block *right; /* right btree block */
3109 struct xfs_btree_block *rrblock; /* right-right btree block */
3110 struct xfs_buf *rrbp; /* right-right buffer pointer */
3111 int rrecs = 0; /* right record count */
3112 struct xfs_btree_cur *tcur; /* temporary btree cursor */
3113 int numrecs; /* temporary numrec count */
3114
3115 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3116 XFS_BTREE_TRACE_ARGI(cur, level);
3117
3118 tcur = NULL;
3119
3120 /* Get the index of the entry being deleted, check for nothing there. */
3121 ptr = cur->bc_ptrs[level];
3122 if (ptr == 0) {
3123 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3124 *stat = 0;
3125 return 0;
3126 }
3127
3128 /* Get the buffer & block containing the record or key/ptr. */
3129 block = xfs_btree_get_block(cur, level, &bp);
3130 numrecs = xfs_btree_get_numrecs(block);
3131
3132#ifdef DEBUG
3133 error = xfs_btree_check_block(cur, block, level, bp);
3134 if (error)
3135 goto error0;
3136#endif
3137
3138 /* Fail if we're off the end of the block. */
3139 if (ptr > numrecs) {
3140 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3141 *stat = 0;
3142 return 0;
3143 }
3144
3145 XFS_BTREE_STATS_INC(cur, delrec);
3146 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr);
3147
3148 /* Excise the entries being deleted. */
3149 if (level > 0) {
3150 /* It's a nonleaf. operate on keys and ptrs */
3151 union xfs_btree_key *lkp;
3152 union xfs_btree_ptr *lpp;
3153
3154 lkp = xfs_btree_key_addr(cur, ptr + 1, block);
3155 lpp = xfs_btree_ptr_addr(cur, ptr + 1, block);
3156
3157#ifdef DEBUG
3158 for (i = 0; i < numrecs - ptr; i++) {
3159 error = xfs_btree_check_ptr(cur, lpp, i, level);
3160 if (error)
3161 goto error0;
3162 }
3163#endif
3164
3165 if (ptr < numrecs) {
3166 xfs_btree_shift_keys(cur, lkp, -1, numrecs - ptr);
3167 xfs_btree_shift_ptrs(cur, lpp, -1, numrecs - ptr);
3168 xfs_btree_log_keys(cur, bp, ptr, numrecs - 1);
3169 xfs_btree_log_ptrs(cur, bp, ptr, numrecs - 1);
3170 }
3171
3172 /*
3173 * If it's the first record in the block, we'll need to pass a
3174 * key up to the next level (updkey).
3175 */
3176 if (ptr == 1)
3177 keyp = xfs_btree_key_addr(cur, 1, block);
3178 } else {
3179 /* It's a leaf. operate on records */
3180 if (ptr < numrecs) {
3181 xfs_btree_shift_recs(cur,
3182 xfs_btree_rec_addr(cur, ptr + 1, block),
3183 -1, numrecs - ptr);
3184 xfs_btree_log_recs(cur, bp, ptr, numrecs - 1);
3185 }
3186
3187 /*
3188 * If it's the first record in the block, we'll need a key
3189 * structure to pass up to the next level (updkey).
3190 */
3191 if (ptr == 1) {
3192 cur->bc_ops->init_key_from_rec(&key,
3193 xfs_btree_rec_addr(cur, 1, block));
3194 keyp = &key;
3195 }
3196 }
3197
3198 /*
3199 * Decrement and log the number of entries in the block.
3200 */
3201 xfs_btree_set_numrecs(block, --numrecs);
3202 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
3203
3204 /*
3205 * If we are tracking the last record in the tree and
3206 * we are at the far right edge of the tree, update it.
3207 */
3208 if (xfs_btree_is_lastrec(cur, block, level)) {
3209 cur->bc_ops->update_lastrec(cur, block, NULL,
3210 ptr, LASTREC_DELREC);
3211 }
3212
3213 /*
3214 * We're at the root level. First, shrink the root block in-memory.
3215 * Try to get rid of the next level down. If we can't then there's
3216 * nothing left to do.
3217 */
3218 if (level == cur->bc_nlevels - 1) {
3219 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3220 xfs_iroot_realloc(cur->bc_private.b.ip, -1,
3221 cur->bc_private.b.whichfork);
3222
3223 error = xfs_btree_kill_iroot(cur);
3224 if (error)
3225 goto error0;
3226
3227 error = xfs_btree_dec_cursor(cur, level, stat);
3228 if (error)
3229 goto error0;
3230 *stat = 1;
3231 return 0;
3232 }
3233
3234 /*
3235 * If this is the root level, and there's only one entry left,
3236 * and it's NOT the leaf level, then we can get rid of this
3237 * level.
3238 */
3239 if (numrecs == 1 && level > 0) {
3240 union xfs_btree_ptr *pp;
3241 /*
3242 * pp is still set to the first pointer in the block.
3243 * Make it the new root of the btree.
3244 */
3245 pp = xfs_btree_ptr_addr(cur, 1, block);
c0e59e1a 3246 error = xfs_btree_kill_root(cur, bp, level, pp);
91cca5df
CH		 3247 if (error)
3248 goto error0;
3249 } else if (level > 0) {
3250 error = xfs_btree_dec_cursor(cur, level, stat);
3251 if (error)
3252 goto error0;
3253 }
3254 *stat = 1;
3255 return 0;
3256 }
3257
3258 /*
3259 * If we deleted the leftmost entry in the block, update the
3260 * key values above us in the tree.
3261 */
3262 if (ptr == 1) {
3263 error = xfs_btree_updkey(cur, keyp, level + 1);
3264 if (error)
3265 goto error0;
3266 }
3267
3268 /*
3269 * If the number of records remaining in the block is at least
3270 * the minimum, we're done.
3271 */
3272 if (numrecs >= cur->bc_ops->get_minrecs(cur, level)) {
3273 error = xfs_btree_dec_cursor(cur, level, stat);
3274 if (error)
3275 goto error0;
3276 return 0;
3277 }
3278
3279 /*
3280 * Otherwise, we have to move some records around to keep the
3281 * tree balanced. Look at the left and right sibling blocks to
3282 * see if we can re-balance by moving only one record.
3283 */
3284 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
3285 xfs_btree_get_sibling(cur, block, &lptr, XFS_BB_LEFTSIB);
3286
3287 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3288 /*
3289 * One child of root, need to get a chance to copy its contents
3290 * into the root and delete it. Can't go up to next level,
3291 * there's nothing to delete there.
3292 */
3293 if (xfs_btree_ptr_is_null(cur, &rptr) &&
3294 xfs_btree_ptr_is_null(cur, &lptr) &&
3295 level == cur->bc_nlevels - 2) {
3296 error = xfs_btree_kill_iroot(cur);
3297 if (!error)
3298 error = xfs_btree_dec_cursor(cur, level, stat);
3299 if (error)
3300 goto error0;
3301 return 0;
3302 }
3303 }
3304
3305 ASSERT(!xfs_btree_ptr_is_null(cur, &rptr) ||
3306 !xfs_btree_ptr_is_null(cur, &lptr));
3307
3308 /*
3309 * Duplicate the cursor so our btree manipulations here won't
3310 * disrupt the next level up.
3311 */
3312 error = xfs_btree_dup_cursor(cur, &tcur);
3313 if (error)
3314 goto error0;
3315
3316 /*
3317 * If there's a right sibling, see if it's ok to shift an entry
3318 * out of it.
3319 */
3320 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
3321 /*
3322 * Move the temp cursor to the last entry in the next block.
3323 * Actually any entry but the first would suffice.
3324 */
3325 i = xfs_btree_lastrec(tcur, level);
3326 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3327
3328 error = xfs_btree_increment(tcur, level, &i);
3329 if (error)
3330 goto error0;
3331 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3332
3333 i = xfs_btree_lastrec(tcur, level);
3334 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3335
3336 /* Grab a pointer to the block. */
3337 right = xfs_btree_get_block(tcur, level, &rbp);
3338#ifdef DEBUG
3339 error = xfs_btree_check_block(tcur, right, level, rbp);
3340 if (error)
3341 goto error0;
3342#endif
3343 /* Grab the current block number, for future use. */
3344 xfs_btree_get_sibling(tcur, right, &cptr, XFS_BB_LEFTSIB);
3345
3346 /*
3347 * If right block is full enough so that removing one entry
3348 * won't make it too empty, and left-shifting an entry out
3349 * of right to us works, we're done.
3350 */
3351 if (xfs_btree_get_numrecs(right) - 1 >=
3352 cur->bc_ops->get_minrecs(tcur, level)) {
3353 error = xfs_btree_lshift(tcur, level, &i);
3354 if (error)
3355 goto error0;
3356 if (i) {
3357 ASSERT(xfs_btree_get_numrecs(block) >=
3358 cur->bc_ops->get_minrecs(tcur, level));
3359
3360 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3361 tcur = NULL;
3362
3363 error = xfs_btree_dec_cursor(cur, level, stat);
3364 if (error)
3365 goto error0;
3366 return 0;
3367 }
3368 }
3369
3370 /*
3371 * Otherwise, grab the number of records in right for
3372 * future reference, and fix up the temp cursor to point
3373 * to our block again (last record).
3374 */
3375 rrecs = xfs_btree_get_numrecs(right);
3376 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3377 i = xfs_btree_firstrec(tcur, level);
3378 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3379
3380 error = xfs_btree_decrement(tcur, level, &i);
3381 if (error)
3382 goto error0;
3383 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3384 }
3385 }
3386
3387 /*
3388 * If there's a left sibling, see if it's ok to shift an entry
3389 * out of it.
3390 */
3391 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3392 /*
3393 * Move the temp cursor to the first entry in the
3394 * previous block.
3395 */
3396 i = xfs_btree_firstrec(tcur, level);
3397 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3398
3399 error = xfs_btree_decrement(tcur, level, &i);
3400 if (error)
3401 goto error0;
3402 i = xfs_btree_firstrec(tcur, level);
3403 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3404
3405 /* Grab a pointer to the block. */
3406 left = xfs_btree_get_block(tcur, level, &lbp);
3407#ifdef DEBUG
3408 error = xfs_btree_check_block(cur, left, level, lbp);
3409 if (error)
3410 goto error0;
3411#endif
3412 /* Grab the current block number, for future use. */
3413 xfs_btree_get_sibling(tcur, left, &cptr, XFS_BB_RIGHTSIB);
3414
3415 /*
3416 * If left block is full enough so that removing one entry
3417 * won't make it too empty, and right-shifting an entry out
3418 * of left to us works, we're done.
3419 */
3420 if (xfs_btree_get_numrecs(left) - 1 >=
3421 cur->bc_ops->get_minrecs(tcur, level)) {
3422 error = xfs_btree_rshift(tcur, level, &i);
3423 if (error)
3424 goto error0;
3425 if (i) {
3426 ASSERT(xfs_btree_get_numrecs(block) >=
3427 cur->bc_ops->get_minrecs(tcur, level));
3428 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3429 tcur = NULL;
3430 if (level == 0)
3431 cur->bc_ptrs[0]++;
3432 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3433 *stat = 1;
3434 return 0;
3435 }
3436 }
3437
3438 /*
3439 * Otherwise, grab the number of records in right for
3440 * future reference.
3441 */
3442 lrecs = xfs_btree_get_numrecs(left);
3443 }
3444
3445 /* Delete the temp cursor, we're done with it. */
3446 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3447 tcur = NULL;
3448
3449 /* If here, we need to do a join to keep the tree balanced. */
3450 ASSERT(!xfs_btree_ptr_is_null(cur, &cptr));
3451
3452 if (!xfs_btree_ptr_is_null(cur, &lptr) &&
3453 lrecs + xfs_btree_get_numrecs(block) <=
3454 cur->bc_ops->get_maxrecs(cur, level)) {
3455 /*
3456 * Set "right" to be the starting block,
3457 * "left" to be the left neighbor.
3458 */
3459 rptr = cptr;
3460 right = block;
3461 rbp = bp;
3462 error = xfs_btree_read_buf_block(cur, &lptr, level,
3463 0, &left, &lbp);
3464 if (error)
3465 goto error0;
3466
3467 /*
3468 * If that won't work, see if we can join with the right neighbor block.
3469 */
3470 } else if (!xfs_btree_ptr_is_null(cur, &rptr) &&
3471 rrecs + xfs_btree_get_numrecs(block) <=
3472 cur->bc_ops->get_maxrecs(cur, level)) {
3473 /*
3474 * Set "left" to be the starting block,
3475 * "right" to be the right neighbor.
3476 */
3477 lptr = cptr;
3478 left = block;
3479 lbp = bp;
3480 error = xfs_btree_read_buf_block(cur, &rptr, level,
3481 0, &right, &rbp);
3482 if (error)
3483 goto error0;
3484
3485 /*
3486 * Otherwise, we can't fix the imbalance.
3487 * Just return. This is probably a logic error, but it's not fatal.
3488 */
3489 } else {
3490 error = xfs_btree_dec_cursor(cur, level, stat);
3491 if (error)
3492 goto error0;
3493 return 0;
3494 }
3495
3496 rrecs = xfs_btree_get_numrecs(right);
3497 lrecs = xfs_btree_get_numrecs(left);
3498
3499 /*
3500 * We're now going to join "left" and "right" by moving all the stuff
3501 * in "right" to "left" and deleting "right".
3502 */
3503 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
3504 if (level > 0) {
3505 /* It's a non-leaf. Move keys and pointers. */
3506 union xfs_btree_key *lkp; /* left btree key */
3507 union xfs_btree_ptr *lpp; /* left address pointer */
3508 union xfs_btree_key *rkp; /* right btree key */
3509 union xfs_btree_ptr *rpp; /* right address pointer */
3510
3511 lkp = xfs_btree_key_addr(cur, lrecs + 1, left);
3512 lpp = xfs_btree_ptr_addr(cur, lrecs + 1, left);
3513 rkp = xfs_btree_key_addr(cur, 1, right);
3514 rpp = xfs_btree_ptr_addr(cur, 1, right);
3515#ifdef DEBUG
3516 for (i = 1; i < rrecs; i++) {
3517 error = xfs_btree_check_ptr(cur, rpp, i, level);
3518 if (error)
3519 goto error0;
3520 }
3521#endif
3522 xfs_btree_copy_keys(cur, lkp, rkp, rrecs);
3523 xfs_btree_copy_ptrs(cur, lpp, rpp, rrecs);
3524
3525 xfs_btree_log_keys(cur, lbp, lrecs + 1, lrecs + rrecs);
3526 xfs_btree_log_ptrs(cur, lbp, lrecs + 1, lrecs + rrecs);
3527 } else {
3528 /* It's a leaf. Move records. */
3529 union xfs_btree_rec *lrp; /* left record pointer */
3530 union xfs_btree_rec *rrp; /* right record pointer */
3531
3532 lrp = xfs_btree_rec_addr(cur, lrecs + 1, left);
3533 rrp = xfs_btree_rec_addr(cur, 1, right);
3534
3535 xfs_btree_copy_recs(cur, lrp, rrp, rrecs);
3536 xfs_btree_log_recs(cur, lbp, lrecs + 1, lrecs + rrecs);
3537 }
3538
3539 XFS_BTREE_STATS_INC(cur, join);
3540
3541 /*
9da096fd 3542 * Fix up the number of records and right block pointer in the
91cca5df
CH		 3543 * surviving block, and log it.
3544 */
3545 xfs_btree_set_numrecs(left, lrecs + rrecs);
3546 xfs_btree_get_sibling(cur, right, &cptr, XFS_BB_RIGHTSIB),
3547 xfs_btree_set_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
3548 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
3549
3550 /* If there is a right sibling, point it to the remaining block. */
3551 xfs_btree_get_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
3552 if (!xfs_btree_ptr_is_null(cur, &cptr)) {
3553 error = xfs_btree_read_buf_block(cur, &cptr, level,
3554 0, &rrblock, &rrbp);
3555 if (error)
3556 goto error0;
3557 xfs_btree_set_sibling(cur, rrblock, &lptr, XFS_BB_LEFTSIB);
3558 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
3559 }
3560
3561 /* Free the deleted block. */
3562 error = cur->bc_ops->free_block(cur, rbp);
3563 if (error)
3564 goto error0;
3565 XFS_BTREE_STATS_INC(cur, free);
3566
3567 /*
3568 * If we joined with the left neighbor, set the buffer in the
3569 * cursor to the left block, and fix up the index.
3570 */
3571 if (bp != lbp) {
3572 cur->bc_bufs[level] = lbp;
3573 cur->bc_ptrs[level] += lrecs;
3574 cur->bc_ra[level] = 0;
3575 }
3576 /*
3577 * If we joined with the right neighbor and there's a level above
3578 * us, increment the cursor at that level.
3579 */
3580 else if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) ||
3581 (level + 1 < cur->bc_nlevels)) {
3582 error = xfs_btree_increment(cur, level + 1, &i);
3583 if (error)
3584 goto error0;
3585 }
3586
3587 /*
3588 * Readjust the ptr at this level if it's not a leaf, since it's
3589 * still pointing at the deletion point, which makes the cursor
3590 * inconsistent. If this makes the ptr 0, the caller fixes it up.
3591 * We can't use decrement because it would change the next level up.
3592 */
3593 if (level > 0)
3594 cur->bc_ptrs[level]--;
3595
3596 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3597 /* Return value means the next level up has something to do. */
3598 *stat = 2;
3599 return 0;
3600
3601error0:
3602 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3603 if (tcur)
3604 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
3605 return error;
3606}
3607
3608/*
3609 * Delete the record pointed to by cur.
3610 * The cursor refers to the place where the record was (could be inserted)
3611 * when the operation returns.
3612 */
3613int /* error */
3614xfs_btree_delete(
3615 struct xfs_btree_cur *cur,
3616 int *stat) /* success/failure */
3617{
3618 int error; /* error return value */
3619 int level;
3620 int i;
3621
3622 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3623
3624 /*
3625 * Go up the tree, starting at leaf level.
3626 *
3627 * If 2 is returned then a join was done; go to the next level.
3628 * Otherwise we are done.
3629 */
3630 for (level = 0, i = 2; i == 2; level++) {
3631 error = xfs_btree_delrec(cur, level, &i);
3632 if (error)
3633 goto error0;
3634 }
3635
3636 if (i == 0) {
3637 for (level = 1; level < cur->bc_nlevels; level++) {
3638 if (cur->bc_ptrs[level] == 0) {
3639 error = xfs_btree_decrement(cur, level, &i);
3640 if (error)
3641 goto error0;
3642 break;
3643 }
3644 }
3645 }
3646
3647 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3648 *stat = i;
3649 return 0;
3650error0:
3651 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3652 return error;
3653}
8cc938fe
CH		 3654
3655/*
3656 * Get the data from the pointed-to record.
3657 */
3658int /* error */
3659xfs_btree_get_rec(
3660 struct xfs_btree_cur *cur, /* btree cursor */
3661 union xfs_btree_rec **recp, /* output: btree record */
3662 int *stat) /* output: success/failure */
3663{
3664 struct xfs_btree_block *block; /* btree block */
3665 struct xfs_buf *bp; /* buffer pointer */
3666 int ptr; /* record number */
3667#ifdef DEBUG
3668 int error; /* error return value */
3669#endif
3670
3671 ptr = cur->bc_ptrs[0];
3672 block = xfs_btree_get_block(cur, 0, &bp);
3673
3674#ifdef DEBUG
3675 error = xfs_btree_check_block(cur, block, 0, bp);
3676 if (error)
3677 return error;
3678#endif
3679
3680 /*
3681 * Off the right end or left end, return failure.
3682 */
3683 if (ptr > xfs_btree_get_numrecs(block) || ptr <= 0) {
3684 *stat = 0;
3685 return 0;
3686 }
3687
3688 /*
3689 * Point to the record and extract its data.
3690 */
3691 *recp = xfs_btree_rec_addr(cur, ptr, block);
3692 *stat = 1;
3693 return 0;
3694}
kernel source for telekom puls (alcatel/mediatek)