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Merge remote-tracking branch 'regmap/for-next'
[deliverable/linux.git] / fs / xfs / libxfs / 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"
70a9883c 20#include "xfs_shared.h"
a4fbe6ab 21#include "xfs_format.h"
239880ef
DC		 22#include "xfs_log_format.h"
23#include "xfs_trans_resv.h"
a844f451 24#include "xfs_bit.h"
1da177e4 25#include "xfs_mount.h"
3ab78df2 26#include "xfs_defer.h"
1da177e4 27#include "xfs_inode.h"
239880ef 28#include "xfs_trans.h"
38bb7423 29#include "xfs_inode_item.h"
ee1a47ab 30#include "xfs_buf_item.h"
a844f451 31#include "xfs_btree.h"
1da177e4 32#include "xfs_error.h"
0b1b213f 33#include "xfs_trace.h"
ee1a47ab 34#include "xfs_cksum.h"
cf11da9c 35#include "xfs_alloc.h"
a45086e2 36#include "xfs_log.h"
1da177e4
LT		 37
38/*
39 * Cursor allocation zone.
40 */
41kmem_zone_t *xfs_btree_cur_zone;
42
43/*
44 * Btree magic numbers.
45 */
ee1a47ab 46static const __uint32_t xfs_magics[2][XFS_BTNUM_MAX] = {
b8704944 47 { XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, 0, XFS_BMAP_MAGIC, XFS_IBT_MAGIC,
aafc3c24 48 XFS_FIBT_MAGIC },
b8704944 49 { XFS_ABTB_CRC_MAGIC, XFS_ABTC_CRC_MAGIC, XFS_RMAP_CRC_MAGIC,
aafc3c24 50 XFS_BMAP_CRC_MAGIC, XFS_IBT_CRC_MAGIC, XFS_FIBT_CRC_MAGIC }
1da177e4 51};
ee1a47ab
CH		 52#define xfs_btree_magic(cur) \
53 xfs_magics[!!((cur)->bc_flags & XFS_BTREE_CRC_BLOCKS)][cur->bc_btnum]
1da177e4 54
7cc95a82 55STATIC int /* error (0 or EFSCORRUPTED) */
a23f6ef8
CH		 56xfs_btree_check_lblock(
57 struct xfs_btree_cur *cur, /* btree cursor */
7cc95a82 58 struct xfs_btree_block *block, /* btree long form block pointer */
a23f6ef8
CH		 59 int level, /* level of the btree block */
60 struct xfs_buf *bp) /* buffer for block, if any */
61{
ee1a47ab 62 int lblock_ok = 1; /* block passes checks */
a23f6ef8
CH		 63 struct xfs_mount *mp; /* file system mount point */
64
65 mp = cur->bc_mp;
ee1a47ab
CH		 66
67 if (xfs_sb_version_hascrc(&mp->m_sb)) {
68 lblock_ok = lblock_ok &&
ce748eaa
ES		 69 uuid_equal(&block->bb_u.l.bb_uuid,
70 &mp->m_sb.sb_meta_uuid) &&
ee1a47ab
CH		 71 block->bb_u.l.bb_blkno == cpu_to_be64(
72 bp ? bp->b_bn : XFS_BUF_DADDR_NULL);
73 }
74
75 lblock_ok = lblock_ok &&
76 be32_to_cpu(block->bb_magic) == xfs_btree_magic(cur) &&
a23f6ef8
CH		 77 be16_to_cpu(block->bb_level) == level &&
78 be16_to_cpu(block->bb_numrecs) <=
ce5e42db 79 cur->bc_ops->get_maxrecs(cur, level) &&
7cc95a82 80 block->bb_u.l.bb_leftsib &&
d5cf09ba 81 (block->bb_u.l.bb_leftsib == cpu_to_be64(NULLFSBLOCK) ||
7cc95a82 82 XFS_FSB_SANITY_CHECK(mp,
ee1a47ab 83 be64_to_cpu(block->bb_u.l.bb_leftsib))) &&
7cc95a82 84 block->bb_u.l.bb_rightsib &&
d5cf09ba 85 (block->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK) ||
7cc95a82 86 XFS_FSB_SANITY_CHECK(mp,
ee1a47ab
CH		 87 be64_to_cpu(block->bb_u.l.bb_rightsib)));
88
a23f6ef8
CH		 89 if (unlikely(XFS_TEST_ERROR(!lblock_ok, mp,
90 XFS_ERRTAG_BTREE_CHECK_LBLOCK,
91 XFS_RANDOM_BTREE_CHECK_LBLOCK))) {
92 if (bp)
0b1b213f 93 trace_xfs_btree_corrupt(bp, _RET_IP_);
ee1a47ab 94 XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
2451337d 95 return -EFSCORRUPTED;
a23f6ef8
CH		 96 }
97 return 0;
98}
99
3cc7524c 100STATIC int /* error (0 or EFSCORRUPTED) */
1da177e4 101xfs_btree_check_sblock(
a23f6ef8 102 struct xfs_btree_cur *cur, /* btree cursor */
7cc95a82 103 struct xfs_btree_block *block, /* btree short form block pointer */
1da177e4 104 int level, /* level of the btree block */
a23f6ef8 105 struct xfs_buf *bp) /* buffer containing block */
1da177e4 106{
ee1a47ab 107 struct xfs_mount *mp; /* file system mount point */
a23f6ef8
CH		 108 struct xfs_buf *agbp; /* buffer for ag. freespace struct */
109 struct xfs_agf *agf; /* ag. freespace structure */
1da177e4 110 xfs_agblock_t agflen; /* native ag. freespace length */
ee1a47ab 111 int sblock_ok = 1; /* block passes checks */
1da177e4 112
ee1a47ab 113 mp = cur->bc_mp;
1da177e4
LT		 114 agbp = cur->bc_private.a.agbp;
115 agf = XFS_BUF_TO_AGF(agbp);
16259e7d 116 agflen = be32_to_cpu(agf->agf_length);
ee1a47ab
CH		 117
118 if (xfs_sb_version_hascrc(&mp->m_sb)) {
119 sblock_ok = sblock_ok &&
ce748eaa
ES		 120 uuid_equal(&block->bb_u.s.bb_uuid,
121 &mp->m_sb.sb_meta_uuid) &&
ee1a47ab
CH		 122 block->bb_u.s.bb_blkno == cpu_to_be64(
123 bp ? bp->b_bn : XFS_BUF_DADDR_NULL);
124 }
125
126 sblock_ok = sblock_ok &&
127 be32_to_cpu(block->bb_magic) == xfs_btree_magic(cur) &&
16259e7d
CH		 128 be16_to_cpu(block->bb_level) == level &&
129 be16_to_cpu(block->bb_numrecs) <=
ce5e42db 130 cur->bc_ops->get_maxrecs(cur, level) &&
69ef921b 131 (block->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK) ||
7cc95a82
CH		 132 be32_to_cpu(block->bb_u.s.bb_leftsib) < agflen) &&
133 block->bb_u.s.bb_leftsib &&
69ef921b 134 (block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK) ||
7cc95a82
CH		 135 be32_to_cpu(block->bb_u.s.bb_rightsib) < agflen) &&
136 block->bb_u.s.bb_rightsib;
ee1a47ab
CH		 137
138 if (unlikely(XFS_TEST_ERROR(!sblock_ok, mp,
1da177e4
LT		 139 XFS_ERRTAG_BTREE_CHECK_SBLOCK,
140 XFS_RANDOM_BTREE_CHECK_SBLOCK))) {
141 if (bp)
0b1b213f 142 trace_xfs_btree_corrupt(bp, _RET_IP_);
ee1a47ab 143 XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
2451337d 144 return -EFSCORRUPTED;
1da177e4
LT		 145 }
146 return 0;
147}
148
149/*
a23f6ef8
CH		 150 * Debug routine: check that block header is ok.
151 */
152int
153xfs_btree_check_block(
154 struct xfs_btree_cur *cur, /* btree cursor */
155 struct xfs_btree_block *block, /* generic btree block pointer */
156 int level, /* level of the btree block */
157 struct xfs_buf *bp) /* buffer containing block, if any */
158{
7cc95a82
CH		 159 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
160 return xfs_btree_check_lblock(cur, block, level, bp);
161 else
162 return xfs_btree_check_sblock(cur, block, level, bp);
a23f6ef8
CH		 163}
164
165/*
166 * Check that (long) pointer is ok.
167 */
168int /* error (0 or EFSCORRUPTED) */
169xfs_btree_check_lptr(
170 struct xfs_btree_cur *cur, /* btree cursor */
d5cf09ba 171 xfs_fsblock_t bno, /* btree block disk address */
a23f6ef8
CH		 172 int level) /* btree block level */
173{
5fb5aeee 174 XFS_WANT_CORRUPTED_RETURN(cur->bc_mp,
a23f6ef8 175 level > 0 &&
d5cf09ba 176 bno != NULLFSBLOCK &&
a23f6ef8
CH		 177 XFS_FSB_SANITY_CHECK(cur->bc_mp, bno));
178 return 0;
179}
180
24ee0e49 181#ifdef DEBUG
a23f6ef8
CH		 182/*
183 * Check that (short) pointer is ok.
1da177e4 184 */
3cc7524c 185STATIC int /* error (0 or EFSCORRUPTED) */
1da177e4 186xfs_btree_check_sptr(
a23f6ef8
CH		 187 struct xfs_btree_cur *cur, /* btree cursor */
188 xfs_agblock_t bno, /* btree block disk address */
189 int level) /* btree block level */
1da177e4 190{
a23f6ef8 191 xfs_agblock_t agblocks = cur->bc_mp->m_sb.sb_agblocks;
1da177e4 192
5fb5aeee 193 XFS_WANT_CORRUPTED_RETURN(cur->bc_mp,
1da177e4 194 level > 0 &&
a23f6ef8
CH		 195 bno != NULLAGBLOCK &&
196 bno != 0 &&
197 bno < agblocks);
1da177e4
LT		 198 return 0;
199}
200
a23f6ef8
CH		 201/*
202 * Check that block ptr is ok.
203 */
3cc7524c 204STATIC int /* error (0 or EFSCORRUPTED) */
a23f6ef8
CH		 205xfs_btree_check_ptr(
206 struct xfs_btree_cur *cur, /* btree cursor */
207 union xfs_btree_ptr *ptr, /* btree block disk address */
208 int index, /* offset from ptr to check */
209 int level) /* btree block level */
210{
211 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
212 return xfs_btree_check_lptr(cur,
213 be64_to_cpu((&ptr->l)[index]), level);
214 } else {
215 return xfs_btree_check_sptr(cur,
216 be32_to_cpu((&ptr->s)[index]), level);
217 }
218}
24ee0e49 219#endif
a23f6ef8 220
ee1a47ab
CH		 221/*
222 * Calculate CRC on the whole btree block and stuff it into the
223 * long-form btree header.
224 *
225 * Prior to calculting the CRC, pull the LSN out of the buffer log item and put
fef4ded8 226 * it into the buffer so recovery knows what the last modification was that made
ee1a47ab
CH		 227 * it to disk.
228 */
229void
230xfs_btree_lblock_calc_crc(
231 struct xfs_buf *bp)
232{
233 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
234 struct xfs_buf_log_item *bip = bp->b_fspriv;
235
236 if (!xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb))
237 return;
238 if (bip)
239 block->bb_u.l.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
f1dbcd7e 240 xfs_buf_update_cksum(bp, XFS_BTREE_LBLOCK_CRC_OFF);
ee1a47ab
CH		 241}
242
243bool
244xfs_btree_lblock_verify_crc(
245 struct xfs_buf *bp)
246{
a45086e2
BF		 247 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
248 struct xfs_mount *mp = bp->b_target->bt_mount;
249
250 if (xfs_sb_version_hascrc(&mp->m_sb)) {
251 if (!xfs_log_check_lsn(mp, be64_to_cpu(block->bb_u.l.bb_lsn)))
252 return false;
51582170 253 return xfs_buf_verify_cksum(bp, XFS_BTREE_LBLOCK_CRC_OFF);
a45086e2 254 }
51582170 255
ee1a47ab
CH		 256 return true;
257}
258
259/*
260 * Calculate CRC on the whole btree block and stuff it into the
261 * short-form btree header.
262 *
263 * Prior to calculting the CRC, pull the LSN out of the buffer log item and put
fef4ded8 264 * it into the buffer so recovery knows what the last modification was that made
ee1a47ab
CH		 265 * it to disk.
266 */
267void
268xfs_btree_sblock_calc_crc(
269 struct xfs_buf *bp)
270{
271 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
272 struct xfs_buf_log_item *bip = bp->b_fspriv;
273
274 if (!xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb))
275 return;
276 if (bip)
277 block->bb_u.s.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
f1dbcd7e 278 xfs_buf_update_cksum(bp, XFS_BTREE_SBLOCK_CRC_OFF);
ee1a47ab
CH		 279}
280
281bool
282xfs_btree_sblock_verify_crc(
283 struct xfs_buf *bp)
284{
a45086e2
BF		 285 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
286 struct xfs_mount *mp = bp->b_target->bt_mount;
287
288 if (xfs_sb_version_hascrc(&mp->m_sb)) {
289 if (!xfs_log_check_lsn(mp, be64_to_cpu(block->bb_u.s.bb_lsn)))
290 return false;
51582170 291 return xfs_buf_verify_cksum(bp, XFS_BTREE_SBLOCK_CRC_OFF);
a45086e2 292 }
51582170 293
ee1a47ab
CH		 294 return true;
295}
296
c46ee8ad
CH		 297static int
298xfs_btree_free_block(
299 struct xfs_btree_cur *cur,
300 struct xfs_buf *bp)
301{
302 int error;
303
304 error = cur->bc_ops->free_block(cur, bp);
edfd9dd5
CH		 305 if (!error) {
306 xfs_trans_binval(cur->bc_tp, bp);
c46ee8ad 307 XFS_BTREE_STATS_INC(cur, free);
edfd9dd5 308 }
c46ee8ad
CH		 309 return error;
310}
311
1da177e4
LT		 312/*
313 * Delete the btree cursor.
314 */
315void
316xfs_btree_del_cursor(
317 xfs_btree_cur_t *cur, /* btree cursor */
318 int error) /* del because of error */
319{
320 int i; /* btree level */
321
322 /*
323 * Clear the buffer pointers, and release the buffers.
324 * If we're doing this in the face of an error, we
325 * need to make sure to inspect all of the entries
326 * in the bc_bufs array for buffers to be unlocked.
327 * This is because some of the btree code works from
328 * level n down to 0, and if we get an error along
329 * the way we won't have initialized all the entries
330 * down to 0.
331 */
332 for (i = 0; i < cur->bc_nlevels; i++) {
333 if (cur->bc_bufs[i])
c0e59e1a 334 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[i]);
1da177e4
LT		 335 else if (!error)
336 break;
337 }
338 /*
339 * Can't free a bmap cursor without having dealt with the
340 * allocated indirect blocks' accounting.
341 */
342 ASSERT(cur->bc_btnum != XFS_BTNUM_BMAP ||
343 cur->bc_private.b.allocated == 0);
344 /*
345 * Free the cursor.
346 */
347 kmem_zone_free(xfs_btree_cur_zone, cur);
348}
349
350/*
351 * Duplicate the btree cursor.
352 * Allocate a new one, copy the record, re-get the buffers.
353 */
354int /* error */
355xfs_btree_dup_cursor(
356 xfs_btree_cur_t *cur, /* input cursor */
357 xfs_btree_cur_t **ncur) /* output cursor */
358{
359 xfs_buf_t *bp; /* btree block's buffer pointer */
360 int error; /* error return value */
361 int i; /* level number of btree block */
362 xfs_mount_t *mp; /* mount structure for filesystem */
363 xfs_btree_cur_t *new; /* new cursor value */
364 xfs_trans_t *tp; /* transaction pointer, can be NULL */
365
366 tp = cur->bc_tp;
367 mp = cur->bc_mp;
561f7d17 368
1da177e4
LT		 369 /*
370 * Allocate a new cursor like the old one.
371 */
561f7d17
CH		 372 new = cur->bc_ops->dup_cursor(cur);
373
1da177e4
LT		 374 /*
375 * Copy the record currently in the cursor.
376 */
377 new->bc_rec = cur->bc_rec;
561f7d17 378
1da177e4
LT		 379 /*
380 * For each level current, re-get the buffer and copy the ptr value.
381 */
382 for (i = 0; i < new->bc_nlevels; i++) {
383 new->bc_ptrs[i] = cur->bc_ptrs[i];
384 new->bc_ra[i] = cur->bc_ra[i];
c3f8fc73
DC		 385 bp = cur->bc_bufs[i];
386 if (bp) {
387 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
388 XFS_BUF_ADDR(bp), mp->m_bsize,
3d3e6f64 389 0, &bp,
1813dd64 390 cur->bc_ops->buf_ops);
c3f8fc73 391 if (error) {
1da177e4
LT		 392 xfs_btree_del_cursor(new, error);
393 *ncur = NULL;
394 return error;
395 }
ee1a47ab
CH		 396 }
397 new->bc_bufs[i] = bp;
1da177e4 398 }
1da177e4
LT		 399 *ncur = new;
400 return 0;
401}
402
65f1eaea
CH		 403/*
404 * XFS btree block layout and addressing:
405 *
406 * There are two types of blocks in the btree: leaf and non-leaf blocks.
407 *
408 * The leaf record start with a header then followed by records containing
409 * the values. A non-leaf block also starts with the same header, and
410 * then first contains lookup keys followed by an equal number of pointers
411 * to the btree blocks at the previous level.
412 *
413 * +--------+-------+-------+-------+-------+-------+-------+
414 * Leaf: | header | rec 1 | rec 2 | rec 3 | rec 4 | rec 5 | rec N |
415 * +--------+-------+-------+-------+-------+-------+-------+
416 *
417 * +--------+-------+-------+-------+-------+-------+-------+
418 * Non-Leaf: | header | key 1 | key 2 | key N | ptr 1 | ptr 2 | ptr N |
419 * +--------+-------+-------+-------+-------+-------+-------+
420 *
421 * The header is called struct xfs_btree_block for reasons better left unknown
422 * and comes in different versions for short (32bit) and long (64bit) block
423 * pointers. The record and key structures are defined by the btree instances
424 * and opaque to the btree core. The block pointers are simple disk endian
425 * integers, available in a short (32bit) and long (64bit) variant.
426 *
427 * The helpers below calculate the offset of a given record, key or pointer
428 * into a btree block (xfs_btree_*_offset) or return a pointer to the given
429 * record, key or pointer (xfs_btree_*_addr). Note that all addressing
430 * inside the btree block is done using indices starting at one, not zero!
2c813ad6
DW		 431 *
432 * If XFS_BTREE_OVERLAPPING is set, then this btree supports keys containing
433 * overlapping intervals. In such a tree, records are still sorted lowest to
434 * highest and indexed by the smallest key value that refers to the record.
435 * However, nodes are different: each pointer has two associated keys -- one
436 * indexing the lowest key available in the block(s) below (the same behavior
437 * as the key in a regular btree) and another indexing the highest key
438 * available in the block(s) below. Because records are /not/ sorted by the
439 * highest key, all leaf block updates require us to compute the highest key
440 * that matches any record in the leaf and to recursively update the high keys
441 * in the nodes going further up in the tree, if necessary. Nodes look like
442 * this:
443 *
444 * +--------+-----+-----+-----+-----+-----+-------+-------+-----+
445 * Non-Leaf: | header | lo1 | hi1 | lo2 | hi2 | ... | ptr 1 | ptr 2 | ... |
446 * +--------+-----+-----+-----+-----+-----+-------+-------+-----+
447 *
448 * To perform an interval query on an overlapped tree, perform the usual
449 * depth-first search and use the low and high keys to decide if we can skip
450 * that particular node. If a leaf node is reached, return the records that
451 * intersect the interval. Note that an interval query may return numerous
452 * entries. For a non-overlapped tree, simply search for the record associated
453 * with the lowest key and iterate forward until a non-matching record is
454 * found. Section 14.3 ("Interval Trees") of _Introduction to Algorithms_ by
455 * Cormen, Leiserson, Rivest, and Stein (2nd or 3rd ed. only) discuss this in
456 * more detail.
457 *
458 * Why do we care about overlapping intervals? Let's say you have a bunch of
459 * reverse mapping records on a reflink filesystem:
460 *
461 * 1: +- file A startblock B offset C length D -----------+
462 * 2: +- file E startblock F offset G length H --------------+
463 * 3: +- file I startblock F offset J length K --+
464 * 4: +- file L... --+
465 *
466 * Now say we want to map block (B+D) into file A at offset (C+D). Ideally,
467 * we'd simply increment the length of record 1. But how do we find the record
468 * that ends at (B+D-1) (i.e. record 1)? A LE lookup of (B+D-1) would return
469 * record 3 because the keys are ordered first by startblock. An interval
470 * query would return records 1 and 2 because they both overlap (B+D-1), and
471 * from that we can pick out record 1 as the appropriate left neighbor.
472 *
473 * In the non-overlapped case you can do a LE lookup and decrement the cursor
474 * because a record's interval must end before the next record.
65f1eaea
CH		 475 */
476
477/*
478 * Return size of the btree block header for this btree instance.
479 */
480static inline size_t xfs_btree_block_len(struct xfs_btree_cur *cur)
481{
ee1a47ab
CH		 482 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
483 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
484 return XFS_BTREE_LBLOCK_CRC_LEN;
485 return XFS_BTREE_LBLOCK_LEN;
486 }
487 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
488 return XFS_BTREE_SBLOCK_CRC_LEN;
489 return XFS_BTREE_SBLOCK_LEN;
65f1eaea
CH		 490}
491
492/*
493 * Return size of btree block pointers for this btree instance.
494 */
495static inline size_t xfs_btree_ptr_len(struct xfs_btree_cur *cur)
496{
497 return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
498 sizeof(__be64) : sizeof(__be32);
499}
500
501/*
502 * Calculate offset of the n-th record in a btree block.
503 */
504STATIC size_t
505xfs_btree_rec_offset(
506 struct xfs_btree_cur *cur,
507 int n)
508{
509 return xfs_btree_block_len(cur) +
510 (n - 1) * cur->bc_ops->rec_len;
511}
512
513/*
514 * Calculate offset of the n-th key in a btree block.
515 */
516STATIC size_t
517xfs_btree_key_offset(
518 struct xfs_btree_cur *cur,
519 int n)
520{
521 return xfs_btree_block_len(cur) +
522 (n - 1) * cur->bc_ops->key_len;
523}
524
2c813ad6
DW		 525/*
526 * Calculate offset of the n-th high key in a btree block.
527 */
528STATIC size_t
529xfs_btree_high_key_offset(
530 struct xfs_btree_cur *cur,
531 int n)
532{
533 return xfs_btree_block_len(cur) +
534 (n - 1) * cur->bc_ops->key_len + (cur->bc_ops->key_len / 2);
535}
536
65f1eaea
CH		 537/*
538 * Calculate offset of the n-th block pointer in a btree block.
539 */
540STATIC size_t
541xfs_btree_ptr_offset(
542 struct xfs_btree_cur *cur,
543 int n,
544 int level)
545{
546 return xfs_btree_block_len(cur) +
547 cur->bc_ops->get_maxrecs(cur, level) * cur->bc_ops->key_len +
548 (n - 1) * xfs_btree_ptr_len(cur);
549}
550
551/*
552 * Return a pointer to the n-th record in the btree block.
553 */
554STATIC union xfs_btree_rec *
555xfs_btree_rec_addr(
556 struct xfs_btree_cur *cur,
557 int n,
558 struct xfs_btree_block *block)
559{
560 return (union xfs_btree_rec *)
561 ((char *)block + xfs_btree_rec_offset(cur, n));
562}
563
564/*
565 * Return a pointer to the n-th key in the btree block.
566 */
567STATIC union xfs_btree_key *
568xfs_btree_key_addr(
569 struct xfs_btree_cur *cur,
570 int n,
571 struct xfs_btree_block *block)
572{
573 return (union xfs_btree_key *)
574 ((char *)block + xfs_btree_key_offset(cur, n));
575}
576
2c813ad6
DW		 577/*
578 * Return a pointer to the n-th high key in the btree block.
579 */
580STATIC union xfs_btree_key *
581xfs_btree_high_key_addr(
582 struct xfs_btree_cur *cur,
583 int n,
584 struct xfs_btree_block *block)
585{
586 return (union xfs_btree_key *)
587 ((char *)block + xfs_btree_high_key_offset(cur, n));
588}
589
65f1eaea
CH		 590/*
591 * Return a pointer to the n-th block pointer in the btree block.
592 */
593STATIC union xfs_btree_ptr *
594xfs_btree_ptr_addr(
595 struct xfs_btree_cur *cur,
596 int n,
597 struct xfs_btree_block *block)
598{
599 int level = xfs_btree_get_level(block);
600
601 ASSERT(block->bb_level != 0);
602
603 return (union xfs_btree_ptr *)
604 ((char *)block + xfs_btree_ptr_offset(cur, n, level));
605}
606
8186e517 607/*
1cb93863 608 * Get the root block which is stored in the inode.
8186e517
CH		 609 *
610 * For now this btree implementation assumes the btree root is always
611 * stored in the if_broot field of an inode fork.
612 */
613STATIC struct xfs_btree_block *
614xfs_btree_get_iroot(
fbfb24bf 615 struct xfs_btree_cur *cur)
8186e517 616{
fbfb24bf 617 struct xfs_ifork *ifp;
8186e517 618
fbfb24bf
KN		 619 ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, cur->bc_private.b.whichfork);
620 return (struct xfs_btree_block *)ifp->if_broot;
8186e517
CH		 621}
622
1da177e4
LT		 623/*
624 * Retrieve the block pointer from the cursor at the given level.
8186e517 625 * This may be an inode btree root or from a buffer.
1da177e4 626 */
8186e517 627STATIC struct xfs_btree_block * /* generic btree block pointer */
1da177e4 628xfs_btree_get_block(
8186e517 629 struct xfs_btree_cur *cur, /* btree cursor */
1da177e4 630 int level, /* level in btree */
8186e517 631 struct xfs_buf **bpp) /* buffer containing the block */
1da177e4 632{
8186e517
CH		 633 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
634 (level == cur->bc_nlevels - 1)) {
635 *bpp = NULL;
636 return xfs_btree_get_iroot(cur);
1da177e4 637 }
8186e517
CH		 638
639 *bpp = cur->bc_bufs[level];
640 return XFS_BUF_TO_BLOCK(*bpp);
1da177e4
LT		 641}
642
643/*
644 * Get a buffer for the block, return it with no data read.
645 * Long-form addressing.
646 */
647xfs_buf_t * /* buffer for fsbno */
648xfs_btree_get_bufl(
649 xfs_mount_t *mp, /* file system mount point */
650 xfs_trans_t *tp, /* transaction pointer */
651 xfs_fsblock_t fsbno, /* file system block number */
652 uint lock) /* lock flags for get_buf */
653{
1da177e4
LT		 654 xfs_daddr_t d; /* real disk block address */
655
656 ASSERT(fsbno != NULLFSBLOCK);
657 d = XFS_FSB_TO_DADDR(mp, fsbno);
36de9556 658 return xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
1da177e4
LT		 659}
660
661/*
662 * Get a buffer for the block, return it with no data read.
663 * Short-form addressing.
664 */
665xfs_buf_t * /* buffer for agno/agbno */
666xfs_btree_get_bufs(
667 xfs_mount_t *mp, /* file system mount point */
668 xfs_trans_t *tp, /* transaction pointer */
669 xfs_agnumber_t agno, /* allocation group number */
670 xfs_agblock_t agbno, /* allocation group block number */
671 uint lock) /* lock flags for get_buf */
672{
1da177e4
LT		 673 xfs_daddr_t d; /* real disk block address */
674
675 ASSERT(agno != NULLAGNUMBER);
676 ASSERT(agbno != NULLAGBLOCK);
677 d = XFS_AGB_TO_DADDR(mp, agno, agbno);
36de9556 678 return xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
1da177e4
LT		 679}
680
1da177e4
LT		 681/*
682 * Check for the cursor referring to the last block at the given level.
683 */
684int /* 1=is last block, 0=not last block */
685xfs_btree_islastblock(
686 xfs_btree_cur_t *cur, /* btree cursor */
687 int level) /* level to check */
688{
7cc95a82 689 struct xfs_btree_block *block; /* generic btree block pointer */
1da177e4
LT		 690 xfs_buf_t *bp; /* buffer containing block */
691
692 block = xfs_btree_get_block(cur, level, &bp);
693 xfs_btree_check_block(cur, block, level, bp);
e99ab90d 694 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
d5cf09ba 695 return block->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK);
1da177e4 696 else
69ef921b 697 return block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK);
1da177e4
LT		 698}
699
cdcf4333
CH		 700/*
701 * Change the cursor to point to the first record at the given level.
702 * Other levels are unaffected.
703 */
3cc7524c 704STATIC int /* success=1, failure=0 */
cdcf4333
CH		 705xfs_btree_firstrec(
706 xfs_btree_cur_t *cur, /* btree cursor */
707 int level) /* level to change */
708{
7cc95a82 709 struct xfs_btree_block *block; /* generic btree block pointer */
cdcf4333
CH		 710 xfs_buf_t *bp; /* buffer containing block */
711
712 /*
713 * Get the block pointer for this level.
714 */
715 block = xfs_btree_get_block(cur, level, &bp);
716 xfs_btree_check_block(cur, block, level, bp);
717 /*
718 * It's empty, there is no such record.
719 */
f2277f06 720 if (!block->bb_numrecs)
cdcf4333
CH		 721 return 0;
722 /*
723 * Set the ptr value to 1, that's the first record/key.
724 */
725 cur->bc_ptrs[level] = 1;
726 return 1;
727}
728
1da177e4
LT		 729/*
730 * Change the cursor to point to the last record in the current block
731 * at the given level. Other levels are unaffected.
732 */
3cc7524c 733STATIC int /* success=1, failure=0 */
1da177e4
LT		 734xfs_btree_lastrec(
735 xfs_btree_cur_t *cur, /* btree cursor */
736 int level) /* level to change */
737{
7cc95a82 738 struct xfs_btree_block *block; /* generic btree block pointer */
1da177e4
LT		 739 xfs_buf_t *bp; /* buffer containing block */
740
741 /*
742 * Get the block pointer for this level.
743 */
744 block = xfs_btree_get_block(cur, level, &bp);
745 xfs_btree_check_block(cur, block, level, bp);
746 /*
747 * It's empty, there is no such record.
748 */
f2277f06 749 if (!block->bb_numrecs)
1da177e4
LT		 750 return 0;
751 /*
752 * Set the ptr value to numrecs, that's the last record/key.
753 */
f2277f06 754 cur->bc_ptrs[level] = be16_to_cpu(block->bb_numrecs);
1da177e4
LT		 755 return 1;
756}
757
758/*
759 * Compute first and last byte offsets for the fields given.
760 * Interprets the offsets table, which contains struct field offsets.
761 */
762void
763xfs_btree_offsets(
764 __int64_t fields, /* bitmask of fields */
765 const short *offsets, /* table of field offsets */
766 int nbits, /* number of bits to inspect */
767 int *first, /* output: first byte offset */
768 int *last) /* output: last byte offset */
769{
770 int i; /* current bit number */
771 __int64_t imask; /* mask for current bit number */
772
773 ASSERT(fields != 0);
774 /*
775 * Find the lowest bit, so the first byte offset.
776 */
777 for (i = 0, imask = 1LL; ; i++, imask <<= 1) {
778 if (imask & fields) {
779 *first = offsets[i];
780 break;
781 }
782 }
783 /*
784 * Find the highest bit, so the last byte offset.
785 */
786 for (i = nbits - 1, imask = 1LL << i; ; i--, imask >>= 1) {
787 if (imask & fields) {
788 *last = offsets[i + 1] - 1;
789 break;
790 }
791 }
792}
793
794/*
795 * Get a buffer for the block, return it read in.
796 * Long-form addressing.
797 */
3d3e6f64 798int
1da177e4 799xfs_btree_read_bufl(
3d3e6f64
DC		 800 struct xfs_mount *mp, /* file system mount point */
801 struct xfs_trans *tp, /* transaction pointer */
802 xfs_fsblock_t fsbno, /* file system block number */
803 uint lock, /* lock flags for read_buf */
804 struct xfs_buf **bpp, /* buffer for fsbno */
805 int refval, /* ref count value for buffer */
1813dd64 806 const struct xfs_buf_ops *ops)
1da177e4 807{
3d3e6f64 808 struct xfs_buf *bp; /* return value */
1da177e4 809 xfs_daddr_t d; /* real disk block address */
3d3e6f64 810 int error;
1da177e4
LT		 811
812 ASSERT(fsbno != NULLFSBLOCK);
813 d = XFS_FSB_TO_DADDR(mp, fsbno);
c3f8fc73 814 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
1813dd64 815 mp->m_bsize, lock, &bp, ops);
c3f8fc73 816 if (error)
1da177e4 817 return error;
821eb21d 818 if (bp)
38f23232 819 xfs_buf_set_ref(bp, refval);
1da177e4
LT		 820 *bpp = bp;
821 return 0;
822}
823
1da177e4
LT		 824/*
825 * Read-ahead the block, don't wait for it, don't return a buffer.
826 * Long-form addressing.
827 */
828/* ARGSUSED */
829void
830xfs_btree_reada_bufl(
3d3e6f64
DC		 831 struct xfs_mount *mp, /* file system mount point */
832 xfs_fsblock_t fsbno, /* file system block number */
833 xfs_extlen_t count, /* count of filesystem blocks */
1813dd64 834 const struct xfs_buf_ops *ops)
1da177e4
LT		 835{
836 xfs_daddr_t d;
837
838 ASSERT(fsbno != NULLFSBLOCK);
839 d = XFS_FSB_TO_DADDR(mp, fsbno);
1813dd64 840 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, ops);
1da177e4
LT		 841}
842
843/*
844 * Read-ahead the block, don't wait for it, don't return a buffer.
845 * Short-form addressing.
846 */
847/* ARGSUSED */
848void
849xfs_btree_reada_bufs(
3d3e6f64
DC		 850 struct xfs_mount *mp, /* file system mount point */
851 xfs_agnumber_t agno, /* allocation group number */
852 xfs_agblock_t agbno, /* allocation group block number */
853 xfs_extlen_t count, /* count of filesystem blocks */
1813dd64 854 const struct xfs_buf_ops *ops)
1da177e4
LT		 855{
856 xfs_daddr_t d;
857
858 ASSERT(agno != NULLAGNUMBER);
859 ASSERT(agbno != NULLAGBLOCK);
860 d = XFS_AGB_TO_DADDR(mp, agno, agbno);
1813dd64 861 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, ops);
1da177e4
LT		 862}
863
b524bfee
CH		 864STATIC int
865xfs_btree_readahead_lblock(
866 struct xfs_btree_cur *cur,
867 int lr,
868 struct xfs_btree_block *block)
869{
870 int rval = 0;
d5cf09ba
CH		 871 xfs_fsblock_t left = be64_to_cpu(block->bb_u.l.bb_leftsib);
872 xfs_fsblock_t right = be64_to_cpu(block->bb_u.l.bb_rightsib);
b524bfee 873
d5cf09ba 874 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLFSBLOCK) {
3d3e6f64 875 xfs_btree_reada_bufl(cur->bc_mp, left, 1,
1813dd64 876 cur->bc_ops->buf_ops);
b524bfee
CH		 877 rval++;
878 }
879
d5cf09ba 880 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLFSBLOCK) {
3d3e6f64 881 xfs_btree_reada_bufl(cur->bc_mp, right, 1,
1813dd64 882 cur->bc_ops->buf_ops);
b524bfee
CH		 883 rval++;
884 }
885
886 return rval;
887}
888
889STATIC int
890xfs_btree_readahead_sblock(
891 struct xfs_btree_cur *cur,
892 int lr,
893 struct xfs_btree_block *block)
894{
895 int rval = 0;
896 xfs_agblock_t left = be32_to_cpu(block->bb_u.s.bb_leftsib);
897 xfs_agblock_t right = be32_to_cpu(block->bb_u.s.bb_rightsib);
898
899
900 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLAGBLOCK) {
901 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
1813dd64 902 left, 1, cur->bc_ops->buf_ops);
b524bfee
CH		 903 rval++;
904 }
905
906 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLAGBLOCK) {
907 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
1813dd64 908 right, 1, cur->bc_ops->buf_ops);
b524bfee
CH		 909 rval++;
910 }
911
912 return rval;
913}
914
1da177e4
LT		 915/*
916 * Read-ahead btree blocks, at the given level.
917 * Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA.
918 */
3cc7524c 919STATIC int
b524bfee
CH		 920xfs_btree_readahead(
921 struct xfs_btree_cur *cur, /* btree cursor */
1da177e4
LT		 922 int lev, /* level in btree */
923 int lr) /* left/right bits */
924{
b524bfee
CH		 925 struct xfs_btree_block *block;
926
927 /*
928 * No readahead needed if we are at the root level and the
929 * btree root is stored in the inode.
930 */
931 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
932 (lev == cur->bc_nlevels - 1))
933 return 0;
934
935 if ((cur->bc_ra[lev] | lr) == cur->bc_ra[lev])
936 return 0;
1da177e4 937
1da177e4 938 cur->bc_ra[lev] |= lr;
b524bfee
CH		 939 block = XFS_BUF_TO_BLOCK(cur->bc_bufs[lev]);
940
941 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
942 return xfs_btree_readahead_lblock(cur, lr, block);
943 return xfs_btree_readahead_sblock(cur, lr, block);
1da177e4
LT		 944}
945
21b5c978
DC		 946STATIC xfs_daddr_t
947xfs_btree_ptr_to_daddr(
948 struct xfs_btree_cur *cur,
949 union xfs_btree_ptr *ptr)
950{
951 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
d5cf09ba 952 ASSERT(ptr->l != cpu_to_be64(NULLFSBLOCK));
21b5c978
DC		 953
954 return XFS_FSB_TO_DADDR(cur->bc_mp, be64_to_cpu(ptr->l));
955 } else {
956 ASSERT(cur->bc_private.a.agno != NULLAGNUMBER);
957 ASSERT(ptr->s != cpu_to_be32(NULLAGBLOCK));
958
959 return XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_private.a.agno,
960 be32_to_cpu(ptr->s));
961 }
962}
963
964/*
965 * Readahead @count btree blocks at the given @ptr location.
966 *
967 * We don't need to care about long or short form btrees here as we have a
968 * method of converting the ptr directly to a daddr available to us.
969 */
970STATIC void
971xfs_btree_readahead_ptr(
972 struct xfs_btree_cur *cur,
973 union xfs_btree_ptr *ptr,
974 xfs_extlen_t count)
975{
976 xfs_buf_readahead(cur->bc_mp->m_ddev_targp,
977 xfs_btree_ptr_to_daddr(cur, ptr),
978 cur->bc_mp->m_bsize * count, cur->bc_ops->buf_ops);
979}
980
1da177e4
LT		 981/*
982 * Set the buffer for level "lev" in the cursor to bp, releasing
983 * any previous buffer.
984 */
c0e59e1a 985STATIC void
1da177e4
LT		 986xfs_btree_setbuf(
987 xfs_btree_cur_t *cur, /* btree cursor */
988 int lev, /* level in btree */
989 xfs_buf_t *bp) /* new buffer to set */
990{
7cc95a82 991 struct xfs_btree_block *b; /* btree block */
1da177e4 992
c0e59e1a
CH		 993 if (cur->bc_bufs[lev])
994 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[lev]);
1da177e4
LT		 995 cur->bc_bufs[lev] = bp;
996 cur->bc_ra[lev] = 0;
c0e59e1a 997
1da177e4 998 b = XFS_BUF_TO_BLOCK(bp);
e99ab90d 999 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
d5cf09ba 1000 if (b->bb_u.l.bb_leftsib == cpu_to_be64(NULLFSBLOCK))
1da177e4 1001 cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
d5cf09ba 1002 if (b->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK))
1da177e4
LT		 1003 cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
1004 } else {
69ef921b 1005 if (b->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK))
1da177e4 1006 cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
69ef921b 1007 if (b->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK))
1da177e4
LT		 1008 cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
1009 }
1010}
637aa50f
CH		 1011
1012STATIC int
1013xfs_btree_ptr_is_null(
1014 struct xfs_btree_cur *cur,
1015 union xfs_btree_ptr *ptr)
1016{
1017 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
d5cf09ba 1018 return ptr->l == cpu_to_be64(NULLFSBLOCK);
637aa50f 1019 else
69ef921b 1020 return ptr->s == cpu_to_be32(NULLAGBLOCK);
637aa50f
CH		 1021}
1022
4b22a571
CH		 1023STATIC void
1024xfs_btree_set_ptr_null(
1025 struct xfs_btree_cur *cur,
1026 union xfs_btree_ptr *ptr)
1027{
1028 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
d5cf09ba 1029 ptr->l = cpu_to_be64(NULLFSBLOCK);
4b22a571
CH		 1030 else
1031 ptr->s = cpu_to_be32(NULLAGBLOCK);
1032}
1033
637aa50f
CH		 1034/*
1035 * Get/set/init sibling pointers
1036 */
1037STATIC void
1038xfs_btree_get_sibling(
1039 struct xfs_btree_cur *cur,
1040 struct xfs_btree_block *block,
1041 union xfs_btree_ptr *ptr,
1042 int lr)
1043{
1044 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
1045
1046 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1047 if (lr == XFS_BB_RIGHTSIB)
1048 ptr->l = block->bb_u.l.bb_rightsib;
1049 else
1050 ptr->l = block->bb_u.l.bb_leftsib;
1051 } else {
1052 if (lr == XFS_BB_RIGHTSIB)
1053 ptr->s = block->bb_u.s.bb_rightsib;
1054 else
1055 ptr->s = block->bb_u.s.bb_leftsib;
1056 }
1057}
1058
f5eb8e7c
CH		 1059STATIC void
1060xfs_btree_set_sibling(
1061 struct xfs_btree_cur *cur,
1062 struct xfs_btree_block *block,
1063 union xfs_btree_ptr *ptr,
1064 int lr)
1065{
1066 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
1067
1068 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1069 if (lr == XFS_BB_RIGHTSIB)
1070 block->bb_u.l.bb_rightsib = ptr->l;
1071 else
1072 block->bb_u.l.bb_leftsib = ptr->l;
1073 } else {
1074 if (lr == XFS_BB_RIGHTSIB)
1075 block->bb_u.s.bb_rightsib = ptr->s;
1076 else
1077 block->bb_u.s.bb_leftsib = ptr->s;
1078 }
1079}
1080
ee1a47ab
CH		 1081void
1082xfs_btree_init_block_int(
1083 struct xfs_mount *mp,
1084 struct xfs_btree_block *buf,
1085 xfs_daddr_t blkno,
1086 __u32 magic,
1087 __u16 level,
1088 __u16 numrecs,
1089 __u64 owner,
1090 unsigned int flags)
1091{
1092 buf->bb_magic = cpu_to_be32(magic);
1093 buf->bb_level = cpu_to_be16(level);
1094 buf->bb_numrecs = cpu_to_be16(numrecs);
1095
1096 if (flags & XFS_BTREE_LONG_PTRS) {
d5cf09ba
CH		 1097 buf->bb_u.l.bb_leftsib = cpu_to_be64(NULLFSBLOCK);
1098 buf->bb_u.l.bb_rightsib = cpu_to_be64(NULLFSBLOCK);
ee1a47ab
CH		 1099 if (flags & XFS_BTREE_CRC_BLOCKS) {
1100 buf->bb_u.l.bb_blkno = cpu_to_be64(blkno);
1101 buf->bb_u.l.bb_owner = cpu_to_be64(owner);
ce748eaa 1102 uuid_copy(&buf->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid);
ee1a47ab 1103 buf->bb_u.l.bb_pad = 0;
b58fa554 1104 buf->bb_u.l.bb_lsn = 0;
ee1a47ab
CH		 1105 }
1106 } else {
1107 /* owner is a 32 bit value on short blocks */
1108 __u32 __owner = (__u32)owner;
1109
1110 buf->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
1111 buf->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
1112 if (flags & XFS_BTREE_CRC_BLOCKS) {
1113 buf->bb_u.s.bb_blkno = cpu_to_be64(blkno);
1114 buf->bb_u.s.bb_owner = cpu_to_be32(__owner);
ce748eaa 1115 uuid_copy(&buf->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid);
b58fa554 1116 buf->bb_u.s.bb_lsn = 0;
ee1a47ab
CH		 1117 }
1118 }
1119}
1120
b64f3a39 1121void
f5eb8e7c 1122xfs_btree_init_block(
b64f3a39
DC		 1123 struct xfs_mount *mp,
1124 struct xfs_buf *bp,
1125 __u32 magic,
1126 __u16 level,
1127 __u16 numrecs,
ee1a47ab 1128 __u64 owner,
b64f3a39 1129 unsigned int flags)
f5eb8e7c 1130{
ee1a47ab
CH		 1131 xfs_btree_init_block_int(mp, XFS_BUF_TO_BLOCK(bp), bp->b_bn,
1132 magic, level, numrecs, owner, flags);
f5eb8e7c
CH		 1133}
1134
b64f3a39
DC		 1135STATIC void
1136xfs_btree_init_block_cur(
1137 struct xfs_btree_cur *cur,
ee1a47ab 1138 struct xfs_buf *bp,
b64f3a39 1139 int level,
ee1a47ab 1140 int numrecs)
b64f3a39 1141{
ee1a47ab
CH		 1142 __u64 owner;
1143
1144 /*
1145 * we can pull the owner from the cursor right now as the different
1146 * owners align directly with the pointer size of the btree. This may
1147 * change in future, but is safe for current users of the generic btree
1148 * code.
1149 */
1150 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1151 owner = cur->bc_private.b.ip->i_ino;
1152 else
1153 owner = cur->bc_private.a.agno;
1154
1155 xfs_btree_init_block_int(cur->bc_mp, XFS_BUF_TO_BLOCK(bp), bp->b_bn,
1156 xfs_btree_magic(cur), level, numrecs,
1157 owner, cur->bc_flags);
b64f3a39
DC		 1158}
1159
278d0ca1
CH		 1160/*
1161 * Return true if ptr is the last record in the btree and
ee1a47ab 1162 * we need to track updates to this record. The decision
278d0ca1
CH		 1163 * will be further refined in the update_lastrec method.
1164 */
1165STATIC int
1166xfs_btree_is_lastrec(
1167 struct xfs_btree_cur *cur,
1168 struct xfs_btree_block *block,
1169 int level)
1170{
1171 union xfs_btree_ptr ptr;
1172
1173 if (level > 0)
1174 return 0;
1175 if (!(cur->bc_flags & XFS_BTREE_LASTREC_UPDATE))
1176 return 0;
1177
1178 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1179 if (!xfs_btree_ptr_is_null(cur, &ptr))
1180 return 0;
1181 return 1;
1182}
1183
f5eb8e7c
CH		 1184STATIC void
1185xfs_btree_buf_to_ptr(
1186 struct xfs_btree_cur *cur,
1187 struct xfs_buf *bp,
1188 union xfs_btree_ptr *ptr)
1189{
1190 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1191 ptr->l = cpu_to_be64(XFS_DADDR_TO_FSB(cur->bc_mp,
1192 XFS_BUF_ADDR(bp)));
1193 else {
9d87c319 1194 ptr->s = cpu_to_be32(xfs_daddr_to_agbno(cur->bc_mp,
f5eb8e7c
CH		 1195 XFS_BUF_ADDR(bp)));
1196 }
1197}
1198
637aa50f
CH		 1199STATIC void
1200xfs_btree_set_refs(
1201 struct xfs_btree_cur *cur,
1202 struct xfs_buf *bp)
1203{
1204 switch (cur->bc_btnum) {
1205 case XFS_BTNUM_BNO:
1206 case XFS_BTNUM_CNT:
38f23232 1207 xfs_buf_set_ref(bp, XFS_ALLOC_BTREE_REF);
637aa50f
CH		 1208 break;
1209 case XFS_BTNUM_INO:
aafc3c24 1210 case XFS_BTNUM_FINO:
38f23232 1211 xfs_buf_set_ref(bp, XFS_INO_BTREE_REF);
637aa50f
CH		 1212 break;
1213 case XFS_BTNUM_BMAP:
38f23232 1214 xfs_buf_set_ref(bp, XFS_BMAP_BTREE_REF);
637aa50f 1215 break;
035e00ac
DW		 1216 case XFS_BTNUM_RMAP:
1217 xfs_buf_set_ref(bp, XFS_RMAP_BTREE_REF);
1218 break;
637aa50f
CH		 1219 default:
1220 ASSERT(0);
1221 }
1222}
1223
f5eb8e7c
CH		 1224STATIC int
1225xfs_btree_get_buf_block(
1226 struct xfs_btree_cur *cur,
1227 union xfs_btree_ptr *ptr,
1228 int flags,
1229 struct xfs_btree_block **block,
1230 struct xfs_buf **bpp)
1231{
1232 struct xfs_mount *mp = cur->bc_mp;
1233 xfs_daddr_t d;
1234
1235 /* need to sort out how callers deal with failures first */
0cadda1c 1236 ASSERT(!(flags & XBF_TRYLOCK));
f5eb8e7c
CH		 1237
1238 d = xfs_btree_ptr_to_daddr(cur, ptr);
1239 *bpp = xfs_trans_get_buf(cur->bc_tp, mp->m_ddev_targp, d,
1240 mp->m_bsize, flags);
1241
2a30f36d 1242 if (!*bpp)
2451337d 1243 return -ENOMEM;
f5eb8e7c 1244
1813dd64 1245 (*bpp)->b_ops = cur->bc_ops->buf_ops;
f5eb8e7c
CH		 1246 *block = XFS_BUF_TO_BLOCK(*bpp);
1247 return 0;
1248}
1249
637aa50f
CH		 1250/*
1251 * Read in the buffer at the given ptr and return the buffer and
1252 * the block pointer within the buffer.
1253 */
1254STATIC int
1255xfs_btree_read_buf_block(
1256 struct xfs_btree_cur *cur,
1257 union xfs_btree_ptr *ptr,
637aa50f
CH		 1258 int flags,
1259 struct xfs_btree_block **block,
1260 struct xfs_buf **bpp)
1261{
1262 struct xfs_mount *mp = cur->bc_mp;
1263 xfs_daddr_t d;
1264 int error;
1265
1266 /* need to sort out how callers deal with failures first */
0cadda1c 1267 ASSERT(!(flags & XBF_TRYLOCK));
637aa50f
CH		 1268
1269 d = xfs_btree_ptr_to_daddr(cur, ptr);
1270 error = xfs_trans_read_buf(mp, cur->bc_tp, mp->m_ddev_targp, d,
3d3e6f64 1271 mp->m_bsize, flags, bpp,
1813dd64 1272 cur->bc_ops->buf_ops);
637aa50f
CH		 1273 if (error)
1274 return error;
1275
637aa50f
CH		 1276 xfs_btree_set_refs(cur, *bpp);
1277 *block = XFS_BUF_TO_BLOCK(*bpp);
3d3e6f64 1278 return 0;
637aa50f
CH		 1279}
1280
38bb7423
CH		 1281/*
1282 * Copy keys from one btree block to another.
1283 */
1284STATIC void
1285xfs_btree_copy_keys(
1286 struct xfs_btree_cur *cur,
1287 union xfs_btree_key *dst_key,
1288 union xfs_btree_key *src_key,
1289 int numkeys)
1290{
1291 ASSERT(numkeys >= 0);
1292 memcpy(dst_key, src_key, numkeys * cur->bc_ops->key_len);
1293}
1294
278d0ca1
CH		 1295/*
1296 * Copy records from one btree block to another.
1297 */
1298STATIC void
1299xfs_btree_copy_recs(
1300 struct xfs_btree_cur *cur,
1301 union xfs_btree_rec *dst_rec,
1302 union xfs_btree_rec *src_rec,
1303 int numrecs)
1304{
1305 ASSERT(numrecs >= 0);
1306 memcpy(dst_rec, src_rec, numrecs * cur->bc_ops->rec_len);
1307}
1308
9eaead51
CH		 1309/*
1310 * Copy block pointers from one btree block to another.
1311 */
1312STATIC void
1313xfs_btree_copy_ptrs(
1314 struct xfs_btree_cur *cur,
1315 union xfs_btree_ptr *dst_ptr,
1316 union xfs_btree_ptr *src_ptr,
1317 int numptrs)
1318{
1319 ASSERT(numptrs >= 0);
1320 memcpy(dst_ptr, src_ptr, numptrs * xfs_btree_ptr_len(cur));
1321}
1322
1323/*
1324 * Shift keys one index left/right inside a single btree block.
1325 */
1326STATIC void
1327xfs_btree_shift_keys(
1328 struct xfs_btree_cur *cur,
1329 union xfs_btree_key *key,
1330 int dir,
1331 int numkeys)
1332{
1333 char *dst_key;
1334
1335 ASSERT(numkeys >= 0);
1336 ASSERT(dir == 1 || dir == -1);
1337
1338 dst_key = (char *)key + (dir * cur->bc_ops->key_len);
1339 memmove(dst_key, key, numkeys * cur->bc_ops->key_len);
1340}
1341
1342/*
1343 * Shift records one index left/right inside a single btree block.
1344 */
1345STATIC void
1346xfs_btree_shift_recs(
1347 struct xfs_btree_cur *cur,
1348 union xfs_btree_rec *rec,
1349 int dir,
1350 int numrecs)
1351{
1352 char *dst_rec;
1353
1354 ASSERT(numrecs >= 0);
1355 ASSERT(dir == 1 || dir == -1);
1356
1357 dst_rec = (char *)rec + (dir * cur->bc_ops->rec_len);
1358 memmove(dst_rec, rec, numrecs * cur->bc_ops->rec_len);
1359}
1360
1361/*
1362 * Shift block pointers one index left/right inside a single btree block.
1363 */
1364STATIC void
1365xfs_btree_shift_ptrs(
1366 struct xfs_btree_cur *cur,
1367 union xfs_btree_ptr *ptr,
1368 int dir,
1369 int numptrs)
1370{
1371 char *dst_ptr;
1372
1373 ASSERT(numptrs >= 0);
1374 ASSERT(dir == 1 || dir == -1);
1375
1376 dst_ptr = (char *)ptr + (dir * xfs_btree_ptr_len(cur));
1377 memmove(dst_ptr, ptr, numptrs * xfs_btree_ptr_len(cur));
1378}
1379
38bb7423
CH		 1380/*
1381 * Log key values from the btree block.
1382 */
1383STATIC void
1384xfs_btree_log_keys(
1385 struct xfs_btree_cur *cur,
1386 struct xfs_buf *bp,
1387 int first,
1388 int last)
1389{
1390 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1391 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1392
1393 if (bp) {
61fe135c 1394 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
38bb7423
CH		 1395 xfs_trans_log_buf(cur->bc_tp, bp,
1396 xfs_btree_key_offset(cur, first),
1397 xfs_btree_key_offset(cur, last + 1) - 1);
1398 } else {
1399 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1400 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1401 }
1402
1403 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1404}
1405
278d0ca1
CH		 1406/*
1407 * Log record values from the btree block.
1408 */
fd6bcc5b 1409void
278d0ca1
CH		 1410xfs_btree_log_recs(
1411 struct xfs_btree_cur *cur,
1412 struct xfs_buf *bp,
1413 int first,
1414 int last)
1415{
1416 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1417 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1418
61fe135c 1419 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
278d0ca1
CH		 1420 xfs_trans_log_buf(cur->bc_tp, bp,
1421 xfs_btree_rec_offset(cur, first),
1422 xfs_btree_rec_offset(cur, last + 1) - 1);
1423
1424 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1425}
1426
9eaead51
CH		 1427/*
1428 * Log block pointer fields from a btree block (nonleaf).
1429 */
1430STATIC void
1431xfs_btree_log_ptrs(
1432 struct xfs_btree_cur *cur, /* btree cursor */
1433 struct xfs_buf *bp, /* buffer containing btree block */
1434 int first, /* index of first pointer to log */
1435 int last) /* index of last pointer to log */
1436{
1437 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1438 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1439
1440 if (bp) {
1441 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
1442 int level = xfs_btree_get_level(block);
1443
61fe135c 1444 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
9eaead51
CH		 1445 xfs_trans_log_buf(cur->bc_tp, bp,
1446 xfs_btree_ptr_offset(cur, first, level),
1447 xfs_btree_ptr_offset(cur, last + 1, level) - 1);
1448 } else {
1449 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1450 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1451 }
1452
1453 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1454}
1455
1456/*
1457 * Log fields from a btree block header.
1458 */
fd6bcc5b 1459void
9eaead51
CH		 1460xfs_btree_log_block(
1461 struct xfs_btree_cur *cur, /* btree cursor */
1462 struct xfs_buf *bp, /* buffer containing btree block */
1463 int fields) /* mask of fields: XFS_BB_... */
1464{
1465 int first; /* first byte offset logged */
1466 int last; /* last byte offset logged */
1467 static const short soffsets[] = { /* table of offsets (short) */
7cc95a82
CH		 1468 offsetof(struct xfs_btree_block, bb_magic),
1469 offsetof(struct xfs_btree_block, bb_level),
1470 offsetof(struct xfs_btree_block, bb_numrecs),
1471 offsetof(struct xfs_btree_block, bb_u.s.bb_leftsib),
1472 offsetof(struct xfs_btree_block, bb_u.s.bb_rightsib),
ee1a47ab
CH		 1473 offsetof(struct xfs_btree_block, bb_u.s.bb_blkno),
1474 offsetof(struct xfs_btree_block, bb_u.s.bb_lsn),
1475 offsetof(struct xfs_btree_block, bb_u.s.bb_uuid),
1476 offsetof(struct xfs_btree_block, bb_u.s.bb_owner),
1477 offsetof(struct xfs_btree_block, bb_u.s.bb_crc),
1478 XFS_BTREE_SBLOCK_CRC_LEN
9eaead51
CH		 1479 };
1480 static const short loffsets[] = { /* table of offsets (long) */
7cc95a82
CH		 1481 offsetof(struct xfs_btree_block, bb_magic),
1482 offsetof(struct xfs_btree_block, bb_level),
1483 offsetof(struct xfs_btree_block, bb_numrecs),
1484 offsetof(struct xfs_btree_block, bb_u.l.bb_leftsib),
1485 offsetof(struct xfs_btree_block, bb_u.l.bb_rightsib),
ee1a47ab
CH		 1486 offsetof(struct xfs_btree_block, bb_u.l.bb_blkno),
1487 offsetof(struct xfs_btree_block, bb_u.l.bb_lsn),
1488 offsetof(struct xfs_btree_block, bb_u.l.bb_uuid),
1489 offsetof(struct xfs_btree_block, bb_u.l.bb_owner),
1490 offsetof(struct xfs_btree_block, bb_u.l.bb_crc),
1491 offsetof(struct xfs_btree_block, bb_u.l.bb_pad),
1492 XFS_BTREE_LBLOCK_CRC_LEN
9eaead51
CH		 1493 };
1494
1495 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1496 XFS_BTREE_TRACE_ARGBI(cur, bp, fields);
1497
1498 if (bp) {
ee1a47ab
CH		 1499 int nbits;
1500
1501 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) {
1502 /*
1503 * We don't log the CRC when updating a btree
1504 * block but instead recreate it during log
1505 * recovery. As the log buffers have checksums
1506 * of their own this is safe and avoids logging a crc
1507 * update in a lot of places.
1508 */
1509 if (fields == XFS_BB_ALL_BITS)
1510 fields = XFS_BB_ALL_BITS_CRC;
1511 nbits = XFS_BB_NUM_BITS_CRC;
1512 } else {
1513 nbits = XFS_BB_NUM_BITS;
1514 }
9eaead51
CH		 1515 xfs_btree_offsets(fields,
1516 (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
1517 loffsets : soffsets,
ee1a47ab 1518 nbits, &first, &last);
61fe135c 1519 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
9eaead51
CH		 1520 xfs_trans_log_buf(cur->bc_tp, bp, first, last);
1521 } else {
1522 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1523 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1524 }
1525
1526 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1527}
1528
637aa50f
CH		 1529/*
1530 * Increment cursor by one record at the level.
1531 * For nonzero levels the leaf-ward information is untouched.
1532 */
1533int /* error */
1534xfs_btree_increment(
1535 struct xfs_btree_cur *cur,
1536 int level,
1537 int *stat) /* success/failure */
1538{
1539 struct xfs_btree_block *block;
1540 union xfs_btree_ptr ptr;
1541 struct xfs_buf *bp;
1542 int error; /* error return value */
1543 int lev;
1544
1545 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1546 XFS_BTREE_TRACE_ARGI(cur, level);
1547
1548 ASSERT(level < cur->bc_nlevels);
1549
1550 /* Read-ahead to the right at this level. */
1551 xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
1552
1553 /* Get a pointer to the btree block. */
1554 block = xfs_btree_get_block(cur, level, &bp);
1555
1556#ifdef DEBUG
1557 error = xfs_btree_check_block(cur, block, level, bp);
1558 if (error)
1559 goto error0;
1560#endif
1561
1562 /* We're done if we remain in the block after the increment. */
1563 if (++cur->bc_ptrs[level] <= xfs_btree_get_numrecs(block))
1564 goto out1;
1565
1566 /* Fail if we just went off the right edge of the tree. */
1567 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1568 if (xfs_btree_ptr_is_null(cur, &ptr))
1569 goto out0;
1570
1571 XFS_BTREE_STATS_INC(cur, increment);
1572
1573 /*
1574 * March up the tree incrementing pointers.
1575 * Stop when we don't go off the right edge of a block.
1576 */
1577 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1578 block = xfs_btree_get_block(cur, lev, &bp);
1579
1580#ifdef DEBUG
1581 error = xfs_btree_check_block(cur, block, lev, bp);
1582 if (error)
1583 goto error0;
1584#endif
1585
1586 if (++cur->bc_ptrs[lev] <= xfs_btree_get_numrecs(block))
1587 break;
1588
1589 /* Read-ahead the right block for the next loop. */
1590 xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA);
1591 }
1592
1593 /*
1594 * If we went off the root then we are either seriously
1595 * confused or have the tree root in an inode.
1596 */
1597 if (lev == cur->bc_nlevels) {
1598 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1599 goto out0;
1600 ASSERT(0);
2451337d 1601 error = -EFSCORRUPTED;
637aa50f
CH		 1602 goto error0;
1603 }
1604 ASSERT(lev < cur->bc_nlevels);
1605
1606 /*
1607 * Now walk back down the tree, fixing up the cursor's buffer
1608 * pointers and key numbers.
1609 */
1610 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1611 union xfs_btree_ptr *ptrp;
1612
1613 ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
0d7409b1
ES		 1614 --lev;
1615 error = xfs_btree_read_buf_block(cur, ptrp, 0, &block, &bp);
637aa50f
CH		 1616 if (error)
1617 goto error0;
1618
1619 xfs_btree_setbuf(cur, lev, bp);
1620 cur->bc_ptrs[lev] = 1;
1621 }
1622out1:
1623 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1624 *stat = 1;
1625 return 0;
1626
1627out0:
1628 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1629 *stat = 0;
1630 return 0;
1631
1632error0:
1633 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1634 return error;
1635}
8df4da4a
CH		 1636
1637/*
1638 * Decrement cursor by one record at the level.
1639 * For nonzero levels the leaf-ward information is untouched.
1640 */
1641int /* error */
1642xfs_btree_decrement(
1643 struct xfs_btree_cur *cur,
1644 int level,
1645 int *stat) /* success/failure */
1646{
1647 struct xfs_btree_block *block;
1648 xfs_buf_t *bp;
1649 int error; /* error return value */
1650 int lev;
1651 union xfs_btree_ptr ptr;
1652
1653 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1654 XFS_BTREE_TRACE_ARGI(cur, level);
1655
1656 ASSERT(level < cur->bc_nlevels);
1657
1658 /* Read-ahead to the left at this level. */
1659 xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA);
1660
1661 /* We're done if we remain in the block after the decrement. */
1662 if (--cur->bc_ptrs[level] > 0)
1663 goto out1;
1664
1665 /* Get a pointer to the btree block. */
1666 block = xfs_btree_get_block(cur, level, &bp);
1667
1668#ifdef DEBUG
1669 error = xfs_btree_check_block(cur, block, level, bp);
1670 if (error)
1671 goto error0;
1672#endif
1673
1674 /* Fail if we just went off the left edge of the tree. */
1675 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
1676 if (xfs_btree_ptr_is_null(cur, &ptr))
1677 goto out0;
1678
1679 XFS_BTREE_STATS_INC(cur, decrement);
1680
1681 /*
1682 * March up the tree decrementing pointers.
1683 * Stop when we don't go off the left edge of a block.
1684 */
1685 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1686 if (--cur->bc_ptrs[lev] > 0)
1687 break;
1688 /* Read-ahead the left block for the next loop. */
1689 xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA);
1690 }
1691
1692 /*
1693 * If we went off the root then we are seriously confused.
1694 * or the root of the tree is in an inode.
1695 */
1696 if (lev == cur->bc_nlevels) {
1697 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1698 goto out0;
1699 ASSERT(0);
2451337d 1700 error = -EFSCORRUPTED;
8df4da4a
CH		 1701 goto error0;
1702 }
1703 ASSERT(lev < cur->bc_nlevels);
1704
1705 /*
1706 * Now walk back down the tree, fixing up the cursor's buffer
1707 * pointers and key numbers.
1708 */
1709 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1710 union xfs_btree_ptr *ptrp;
1711
1712 ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
0d7409b1
ES		 1713 --lev;
1714 error = xfs_btree_read_buf_block(cur, ptrp, 0, &block, &bp);
8df4da4a
CH		 1715 if (error)
1716 goto error0;
1717 xfs_btree_setbuf(cur, lev, bp);
1718 cur->bc_ptrs[lev] = xfs_btree_get_numrecs(block);
1719 }
1720out1:
1721 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1722 *stat = 1;
1723 return 0;
1724
1725out0:
1726 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1727 *stat = 0;
1728 return 0;
1729
1730error0:
1731 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1732 return error;
1733}
1734
fe033cc8
CH		 1735STATIC int
1736xfs_btree_lookup_get_block(
1737 struct xfs_btree_cur *cur, /* btree cursor */
1738 int level, /* level in the btree */
1739 union xfs_btree_ptr *pp, /* ptr to btree block */
1740 struct xfs_btree_block **blkp) /* return btree block */
1741{
1742 struct xfs_buf *bp; /* buffer pointer for btree block */
1743 int error = 0;
1744
1745 /* special case the root block if in an inode */
1746 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1747 (level == cur->bc_nlevels - 1)) {
1748 *blkp = xfs_btree_get_iroot(cur);
1749 return 0;
1750 }
1751
1752 /*
1753 * If the old buffer at this level for the disk address we are
1754 * looking for re-use it.
1755 *
1756 * Otherwise throw it away and get a new one.
1757 */
1758 bp = cur->bc_bufs[level];
1759 if (bp && XFS_BUF_ADDR(bp) == xfs_btree_ptr_to_daddr(cur, pp)) {
1760 *blkp = XFS_BUF_TO_BLOCK(bp);
1761 return 0;
1762 }
1763
0d7409b1 1764 error = xfs_btree_read_buf_block(cur, pp, 0, blkp, &bp);
fe033cc8
CH		 1765 if (error)
1766 return error;
1767
1768 xfs_btree_setbuf(cur, level, bp);
1769 return 0;
1770}
1771
1772/*
1773 * Get current search key. For level 0 we don't actually have a key
1774 * structure so we make one up from the record. For all other levels
1775 * we just return the right key.
1776 */
1777STATIC union xfs_btree_key *
1778xfs_lookup_get_search_key(
1779 struct xfs_btree_cur *cur,
1780 int level,
1781 int keyno,
1782 struct xfs_btree_block *block,
1783 union xfs_btree_key *kp)
1784{
1785 if (level == 0) {
1786 cur->bc_ops->init_key_from_rec(kp,
1787 xfs_btree_rec_addr(cur, keyno, block));
1788 return kp;
1789 }
1790
1791 return xfs_btree_key_addr(cur, keyno, block);
1792}
1793
1794/*
1795 * Lookup the record. The cursor is made to point to it, based on dir.
49d3da14 1796 * stat is set to 0 if can't find any such record, 1 for success.
fe033cc8
CH		 1797 */
1798int /* error */
1799xfs_btree_lookup(
1800 struct xfs_btree_cur *cur, /* btree cursor */
1801 xfs_lookup_t dir, /* <=, ==, or >= */
1802 int *stat) /* success/failure */
1803{
1804 struct xfs_btree_block *block; /* current btree block */
1805 __int64_t diff; /* difference for the current key */
1806 int error; /* error return value */
1807 int keyno; /* current key number */
1808 int level; /* level in the btree */
1809 union xfs_btree_ptr *pp; /* ptr to btree block */
1810 union xfs_btree_ptr ptr; /* ptr to btree block */
1811
1812 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1813 XFS_BTREE_TRACE_ARGI(cur, dir);
1814
1815 XFS_BTREE_STATS_INC(cur, lookup);
1816
ed150e1a
DW		 1817 /* No such thing as a zero-level tree. */
1818 if (cur->bc_nlevels == 0)
1819 return -EFSCORRUPTED;
1820
fe033cc8
CH		 1821 block = NULL;
1822 keyno = 0;
1823
1824 /* initialise start pointer from cursor */
1825 cur->bc_ops->init_ptr_from_cur(cur, &ptr);
1826 pp = &ptr;
1827
1828 /*
1829 * Iterate over each level in the btree, starting at the root.
1830 * For each level above the leaves, find the key we need, based
1831 * on the lookup record, then follow the corresponding block
1832 * pointer down to the next level.
1833 */
1834 for (level = cur->bc_nlevels - 1, diff = 1; level >= 0; level--) {
1835 /* Get the block we need to do the lookup on. */
1836 error = xfs_btree_lookup_get_block(cur, level, pp, &block);
1837 if (error)
1838 goto error0;
1839
1840 if (diff == 0) {
1841 /*
1842 * If we already had a key match at a higher level, we
1843 * know we need to use the first entry in this block.
1844 */
1845 keyno = 1;
1846 } else {
1847 /* Otherwise search this block. Do a binary search. */
1848
1849 int high; /* high entry number */
1850 int low; /* low entry number */
1851
1852 /* Set low and high entry numbers, 1-based. */
1853 low = 1;
1854 high = xfs_btree_get_numrecs(block);
1855 if (!high) {
1856 /* Block is empty, must be an empty leaf. */
1857 ASSERT(level == 0 && cur->bc_nlevels == 1);
1858
1859 cur->bc_ptrs[0] = dir != XFS_LOOKUP_LE;
1860 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1861 *stat = 0;
1862 return 0;
1863 }
1864
1865 /* Binary search the block. */
1866 while (low <= high) {
1867 union xfs_btree_key key;
1868 union xfs_btree_key *kp;
1869
1870 XFS_BTREE_STATS_INC(cur, compare);
1871
1872 /* keyno is average of low and high. */
1873 keyno = (low + high) >> 1;
1874
1875 /* Get current search key */
1876 kp = xfs_lookup_get_search_key(cur, level,
1877 keyno, block, &key);
1878
1879 /*
1880 * Compute difference to get next direction:
1881 * - less than, move right
1882 * - greater than, move left
1883 * - equal, we're done
1884 */
1885 diff = cur->bc_ops->key_diff(cur, kp);
1886 if (diff < 0)
1887 low = keyno + 1;
1888 else if (diff > 0)
1889 high = keyno - 1;
1890 else
1891 break;
1892 }
1893 }
1894
1895 /*
1896 * If there are more levels, set up for the next level
1897 * by getting the block number and filling in the cursor.
1898 */
1899 if (level > 0) {
1900 /*
1901 * If we moved left, need the previous key number,
1902 * unless there isn't one.
1903 */
1904 if (diff > 0 && --keyno < 1)
1905 keyno = 1;
1906 pp = xfs_btree_ptr_addr(cur, keyno, block);
1907
1908#ifdef DEBUG
1909 error = xfs_btree_check_ptr(cur, pp, 0, level);
1910 if (error)
1911 goto error0;
1912#endif
1913 cur->bc_ptrs[level] = keyno;
1914 }
1915 }
1916
1917 /* Done with the search. See if we need to adjust the results. */
1918 if (dir != XFS_LOOKUP_LE && diff < 0) {
1919 keyno++;
1920 /*
1921 * If ge search and we went off the end of the block, but it's
1922 * not the last block, we're in the wrong block.
1923 */
1924 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1925 if (dir == XFS_LOOKUP_GE &&
1926 keyno > xfs_btree_get_numrecs(block) &&
1927 !xfs_btree_ptr_is_null(cur, &ptr)) {
1928 int i;
1929
1930 cur->bc_ptrs[0] = keyno;
1931 error = xfs_btree_increment(cur, 0, &i);
1932 if (error)
1933 goto error0;
5fb5aeee 1934 XFS_WANT_CORRUPTED_RETURN(cur->bc_mp, i == 1);
fe033cc8
CH		 1935 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1936 *stat = 1;
1937 return 0;
1938 }
1939 } else if (dir == XFS_LOOKUP_LE && diff > 0)
1940 keyno--;
1941 cur->bc_ptrs[0] = keyno;
1942
1943 /* Return if we succeeded or not. */
1944 if (keyno == 0 || keyno > xfs_btree_get_numrecs(block))
1945 *stat = 0;
1946 else if (dir != XFS_LOOKUP_EQ || diff == 0)
1947 *stat = 1;
1948 else
1949 *stat = 0;
1950 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1951 return 0;
1952
1953error0:
1954 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1955 return error;
1956}
38bb7423 1957
2c813ad6
DW		 1958/* Find the high key storage area from a regular key. */
1959STATIC union xfs_btree_key *
1960xfs_btree_high_key_from_key(
1961 struct xfs_btree_cur *cur,
1962 union xfs_btree_key *key)
1963{
1964 ASSERT(cur->bc_flags & XFS_BTREE_OVERLAPPING);
1965 return (union xfs_btree_key *)((char *)key +
1966 (cur->bc_ops->key_len / 2));
1967}
1968
973b8319
DW		 1969/* Determine the low (and high if overlapped) keys of a leaf block */
1970STATIC void
1971xfs_btree_get_leaf_keys(
2c813ad6
DW		 1972 struct xfs_btree_cur *cur,
1973 struct xfs_btree_block *block,
1974 union xfs_btree_key *key)
1975{
2c813ad6
DW		 1976 union xfs_btree_key max_hkey;
1977 union xfs_btree_key hkey;
973b8319 1978 union xfs_btree_rec *rec;
2c813ad6 1979 union xfs_btree_key *high;
973b8319 1980 int n;
2c813ad6 1981
2c813ad6
DW		 1982 rec = xfs_btree_rec_addr(cur, 1, block);
1983 cur->bc_ops->init_key_from_rec(key, rec);
1984
973b8319
DW		 1985 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
1986
1987 cur->bc_ops->init_high_key_from_rec(&max_hkey, rec);
1988 for (n = 2; n <= xfs_btree_get_numrecs(block); n++) {
1989 rec = xfs_btree_rec_addr(cur, n, block);
1990 cur->bc_ops->init_high_key_from_rec(&hkey, rec);
1991 if (cur->bc_ops->diff_two_keys(cur, &hkey, &max_hkey)
1992 > 0)
1993 max_hkey = hkey;
1994 }
2c813ad6 1995
973b8319
DW		 1996 high = xfs_btree_high_key_from_key(cur, key);
1997 memcpy(high, &max_hkey, cur->bc_ops->key_len / 2);
1998 }
2c813ad6
DW		 1999}
2000
973b8319
DW		 2001/* Determine the low (and high if overlapped) keys of a node block */
2002STATIC void
2003xfs_btree_get_node_keys(
2c813ad6
DW		 2004 struct xfs_btree_cur *cur,
2005 struct xfs_btree_block *block,
2006 union xfs_btree_key *key)
2007{
2c813ad6
DW		 2008 union xfs_btree_key *hkey;
2009 union xfs_btree_key *max_hkey;
2010 union xfs_btree_key *high;
973b8319 2011 int n;
2c813ad6 2012
973b8319
DW		 2013 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2014 memcpy(key, xfs_btree_key_addr(cur, 1, block),
2015 cur->bc_ops->key_len / 2);
2016
2017 max_hkey = xfs_btree_high_key_addr(cur, 1, block);
2018 for (n = 2; n <= xfs_btree_get_numrecs(block); n++) {
2019 hkey = xfs_btree_high_key_addr(cur, n, block);
2020 if (cur->bc_ops->diff_two_keys(cur, hkey, max_hkey) > 0)
2021 max_hkey = hkey;
2022 }
2c813ad6 2023
973b8319
DW		 2024 high = xfs_btree_high_key_from_key(cur, key);
2025 memcpy(high, max_hkey, cur->bc_ops->key_len / 2);
2026 } else {
2027 memcpy(key, xfs_btree_key_addr(cur, 1, block),
2028 cur->bc_ops->key_len);
2c813ad6 2029 }
2c813ad6
DW		 2030}
2031
70b22659
DW		 2032/* Derive the keys for any btree block. */
2033STATIC void
2034xfs_btree_get_keys(
2035 struct xfs_btree_cur *cur,
2036 struct xfs_btree_block *block,
2037 union xfs_btree_key *key)
2038{
2039 if (be16_to_cpu(block->bb_level) == 0)
973b8319 2040 xfs_btree_get_leaf_keys(cur, block, key);
70b22659 2041 else
973b8319 2042 xfs_btree_get_node_keys(cur, block, key);
70b22659
DW		 2043}
2044
38bb7423 2045/*
70b22659
DW		 2046 * Decide if we need to update the parent keys of a btree block. For
2047 * a standard btree this is only necessary if we're updating the first
2c813ad6
DW		 2048 * record/key. For an overlapping btree, we must always update the
2049 * keys because the highest key can be in any of the records or keys
2050 * in the block.
38bb7423 2051 */
70b22659
DW		 2052static inline bool
2053xfs_btree_needs_key_update(
2054 struct xfs_btree_cur *cur,
2055 int ptr)
2056{
2c813ad6
DW		 2057 return (cur->bc_flags & XFS_BTREE_OVERLAPPING) || ptr == 1;
2058}
2059
2060/*
2061 * Update the low and high parent keys of the given level, progressing
2062 * towards the root. If force_all is false, stop if the keys for a given
2063 * level do not need updating.
2064 */
2065STATIC int
2066__xfs_btree_updkeys(
2067 struct xfs_btree_cur *cur,
2068 int level,
2069 struct xfs_btree_block *block,
2070 struct xfs_buf *bp0,
2071 bool force_all)
2072{
2073 union xfs_btree_bigkey key; /* keys from current level */
2074 union xfs_btree_key *lkey; /* keys from the next level up */
2075 union xfs_btree_key *hkey;
2076 union xfs_btree_key *nlkey; /* keys from the next level up */
2077 union xfs_btree_key *nhkey;
2078 struct xfs_buf *bp;
2079 int ptr;
2080
2081 ASSERT(cur->bc_flags & XFS_BTREE_OVERLAPPING);
2082
2083 /* Exit if there aren't any parent levels to update. */
2084 if (level + 1 >= cur->bc_nlevels)
2085 return 0;
2086
2087 trace_xfs_btree_updkeys(cur, level, bp0);
2088
2089 lkey = (union xfs_btree_key *)&key;
2090 hkey = xfs_btree_high_key_from_key(cur, lkey);
2091 xfs_btree_get_keys(cur, block, lkey);
2092 for (level++; level < cur->bc_nlevels; level++) {
2093#ifdef DEBUG
2094 int error;
2095#endif
2096 block = xfs_btree_get_block(cur, level, &bp);
2097 trace_xfs_btree_updkeys(cur, level, bp);
2098#ifdef DEBUG
2099 error = xfs_btree_check_block(cur, block, level, bp);
2100 if (error) {
2101 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2102 return error;
2103 }
2104#endif
2105 ptr = cur->bc_ptrs[level];
2106 nlkey = xfs_btree_key_addr(cur, ptr, block);
2107 nhkey = xfs_btree_high_key_addr(cur, ptr, block);
2108 if (!force_all &&
2109 !(cur->bc_ops->diff_two_keys(cur, nlkey, lkey) != 0 ||
2110 cur->bc_ops->diff_two_keys(cur, nhkey, hkey) != 0))
2111 break;
2112 xfs_btree_copy_keys(cur, nlkey, lkey, 1);
2113 xfs_btree_log_keys(cur, bp, ptr, ptr);
2114 if (level + 1 >= cur->bc_nlevels)
2115 break;
973b8319 2116 xfs_btree_get_node_keys(cur, block, lkey);
2c813ad6
DW		 2117 }
2118
2119 return 0;
2120}
2121
2c813ad6
DW		 2122/* Update all the keys from some level in cursor back to the root. */
2123STATIC int
2124xfs_btree_updkeys_force(
2125 struct xfs_btree_cur *cur,
2126 int level)
2127{
2128 struct xfs_buf *bp;
2129 struct xfs_btree_block *block;
2130
2131 block = xfs_btree_get_block(cur, level, &bp);
2132 return __xfs_btree_updkeys(cur, level, block, bp, true);
70b22659
DW		 2133}
2134
2135/*
2136 * Update the parent keys of the given level, progressing towards the root.
2137 */
973b8319 2138STATIC int
70b22659 2139xfs_btree_update_keys(
38bb7423 2140 struct xfs_btree_cur *cur,
38bb7423
CH		 2141 int level)
2142{
2143 struct xfs_btree_block *block;
2144 struct xfs_buf *bp;
2145 union xfs_btree_key *kp;
70b22659 2146 union xfs_btree_key key;
38bb7423
CH		 2147 int ptr;
2148
973b8319
DW		 2149 ASSERT(level >= 0);
2150
2151 block = xfs_btree_get_block(cur, level, &bp);
2152 if (cur->bc_flags & XFS_BTREE_OVERLAPPING)
2153 return __xfs_btree_updkeys(cur, level, block, bp, false);
2c813ad6 2154
38bb7423
CH		 2155 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2156 XFS_BTREE_TRACE_ARGIK(cur, level, keyp);
2157
38bb7423
CH		 2158 /*
2159 * Go up the tree from this level toward the root.
2160 * At each level, update the key value to the value input.
2161 * Stop when we reach a level where the cursor isn't pointing
2162 * at the first entry in the block.
2163 */
70b22659
DW		 2164 xfs_btree_get_keys(cur, block, &key);
2165 for (level++, ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) {
38bb7423
CH		 2166#ifdef DEBUG
2167 int error;
2168#endif
2169 block = xfs_btree_get_block(cur, level, &bp);
2170#ifdef DEBUG
2171 error = xfs_btree_check_block(cur, block, level, bp);
2172 if (error) {
2173 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2174 return error;
2175 }
2176#endif
2177 ptr = cur->bc_ptrs[level];
2178 kp = xfs_btree_key_addr(cur, ptr, block);
70b22659 2179 xfs_btree_copy_keys(cur, kp, &key, 1);
38bb7423
CH		 2180 xfs_btree_log_keys(cur, bp, ptr, ptr);
2181 }
2182
2183 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2184 return 0;
2185}
278d0ca1
CH		 2186
2187/*
2188 * Update the record referred to by cur to the value in the
2189 * given record. This either works (return 0) or gets an
2190 * EFSCORRUPTED error.
2191 */
2192int
2193xfs_btree_update(
2194 struct xfs_btree_cur *cur,
2195 union xfs_btree_rec *rec)
2196{
2197 struct xfs_btree_block *block;
2198 struct xfs_buf *bp;
2199 int error;
2200 int ptr;
2201 union xfs_btree_rec *rp;
2202
2203 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2204 XFS_BTREE_TRACE_ARGR(cur, rec);
2205
2206 /* Pick up the current block. */
2207 block = xfs_btree_get_block(cur, 0, &bp);
2208
2209#ifdef DEBUG
2210 error = xfs_btree_check_block(cur, block, 0, bp);
2211 if (error)
2212 goto error0;
2213#endif
2214 /* Get the address of the rec to be updated. */
2215 ptr = cur->bc_ptrs[0];
2216 rp = xfs_btree_rec_addr(cur, ptr, block);
2217
2218 /* Fill in the new contents and log them. */
2219 xfs_btree_copy_recs(cur, rp, rec, 1);
2220 xfs_btree_log_recs(cur, bp, ptr, ptr);
2221
2222 /*
2223 * If we are tracking the last record in the tree and
2224 * we are at the far right edge of the tree, update it.
2225 */
2226 if (xfs_btree_is_lastrec(cur, block, 0)) {
2227 cur->bc_ops->update_lastrec(cur, block, rec,
2228 ptr, LASTREC_UPDATE);
2229 }
2230
2c813ad6 2231 /* Pass new key value up to our parent. */
70b22659 2232 if (xfs_btree_needs_key_update(cur, ptr)) {
973b8319 2233 error = xfs_btree_update_keys(cur, 0);
278d0ca1
CH		 2234 if (error)
2235 goto error0;
2236 }
2237
2238 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2239 return 0;
2240
2241error0:
2242 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2243 return error;
2244}
2245
687b890a
CH		 2246/*
2247 * Move 1 record left from cur/level if possible.
2248 * Update cur to reflect the new path.
2249 */
3cc7524c 2250STATIC int /* error */
687b890a
CH		 2251xfs_btree_lshift(
2252 struct xfs_btree_cur *cur,
2253 int level,
2254 int *stat) /* success/failure */
2255{
687b890a
CH		 2256 struct xfs_buf *lbp; /* left buffer pointer */
2257 struct xfs_btree_block *left; /* left btree block */
2258 int lrecs; /* left record count */
2259 struct xfs_buf *rbp; /* right buffer pointer */
2260 struct xfs_btree_block *right; /* right btree block */
2c813ad6 2261 struct xfs_btree_cur *tcur; /* temporary btree cursor */
687b890a
CH		 2262 int rrecs; /* right record count */
2263 union xfs_btree_ptr lptr; /* left btree pointer */
2264 union xfs_btree_key *rkp = NULL; /* right btree key */
2265 union xfs_btree_ptr *rpp = NULL; /* right address pointer */
2266 union xfs_btree_rec *rrp = NULL; /* right record pointer */
2267 int error; /* error return value */
2c813ad6 2268 int i;
687b890a
CH		 2269
2270 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2271 XFS_BTREE_TRACE_ARGI(cur, level);
2272
2273 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2274 level == cur->bc_nlevels - 1)
2275 goto out0;
2276
2277 /* Set up variables for this block as "right". */
2278 right = xfs_btree_get_block(cur, level, &rbp);
2279
2280#ifdef DEBUG
2281 error = xfs_btree_check_block(cur, right, level, rbp);
2282 if (error)
2283 goto error0;
2284#endif
2285
2286 /* If we've got no left sibling then we can't shift an entry left. */
2287 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2288 if (xfs_btree_ptr_is_null(cur, &lptr))
2289 goto out0;
2290
2291 /*
2292 * If the cursor entry is the one that would be moved, don't
2293 * do it... it's too complicated.
2294 */
2295 if (cur->bc_ptrs[level] <= 1)
2296 goto out0;
2297
2298 /* Set up the left neighbor as "left". */
0d7409b1 2299 error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
687b890a
CH		 2300 if (error)
2301 goto error0;
2302
2303 /* If it's full, it can't take another entry. */
2304 lrecs = xfs_btree_get_numrecs(left);
2305 if (lrecs == cur->bc_ops->get_maxrecs(cur, level))
2306 goto out0;
2307
2308 rrecs = xfs_btree_get_numrecs(right);
2309
2310 /*
2311 * We add one entry to the left side and remove one for the right side.
9da096fd 2312 * Account for it here, the changes will be updated on disk and logged
687b890a
CH		 2313 * later.
2314 */
2315 lrecs++;
2316 rrecs--;
2317
2318 XFS_BTREE_STATS_INC(cur, lshift);
2319 XFS_BTREE_STATS_ADD(cur, moves, 1);
2320
2321 /*
2322 * If non-leaf, copy a key and a ptr to the left block.
2323 * Log the changes to the left block.
2324 */
2325 if (level > 0) {
2326 /* It's a non-leaf. Move keys and pointers. */
2327 union xfs_btree_key *lkp; /* left btree key */
2328 union xfs_btree_ptr *lpp; /* left address pointer */
2329
2330 lkp = xfs_btree_key_addr(cur, lrecs, left);
2331 rkp = xfs_btree_key_addr(cur, 1, right);
2332
2333 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2334 rpp = xfs_btree_ptr_addr(cur, 1, right);
2335#ifdef DEBUG
2336 error = xfs_btree_check_ptr(cur, rpp, 0, level);
2337 if (error)
2338 goto error0;
2339#endif
2340 xfs_btree_copy_keys(cur, lkp, rkp, 1);
2341 xfs_btree_copy_ptrs(cur, lpp, rpp, 1);
2342
2343 xfs_btree_log_keys(cur, lbp, lrecs, lrecs);
2344 xfs_btree_log_ptrs(cur, lbp, lrecs, lrecs);
2345
4a26e66e
CH		 2346 ASSERT(cur->bc_ops->keys_inorder(cur,
2347 xfs_btree_key_addr(cur, lrecs - 1, left), lkp));
687b890a
CH		 2348 } else {
2349 /* It's a leaf. Move records. */
2350 union xfs_btree_rec *lrp; /* left record pointer */
2351
2352 lrp = xfs_btree_rec_addr(cur, lrecs, left);
2353 rrp = xfs_btree_rec_addr(cur, 1, right);
2354
2355 xfs_btree_copy_recs(cur, lrp, rrp, 1);
2356 xfs_btree_log_recs(cur, lbp, lrecs, lrecs);
2357
4a26e66e
CH		 2358 ASSERT(cur->bc_ops->recs_inorder(cur,
2359 xfs_btree_rec_addr(cur, lrecs - 1, left), lrp));
687b890a
CH		 2360 }
2361
2362 xfs_btree_set_numrecs(left, lrecs);
2363 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2364
2365 xfs_btree_set_numrecs(right, rrecs);
2366 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2367
2368 /*
2369 * Slide the contents of right down one entry.
2370 */
2371 XFS_BTREE_STATS_ADD(cur, moves, rrecs - 1);
2372 if (level > 0) {
2373 /* It's a nonleaf. operate on keys and ptrs */
2374#ifdef DEBUG
2375 int i; /* loop index */
2376
2377 for (i = 0; i < rrecs; i++) {
2378 error = xfs_btree_check_ptr(cur, rpp, i + 1, level);
2379 if (error)
2380 goto error0;
2381 }
2382#endif
2383 xfs_btree_shift_keys(cur,
2384 xfs_btree_key_addr(cur, 2, right),
2385 -1, rrecs);
2386 xfs_btree_shift_ptrs(cur,
2387 xfs_btree_ptr_addr(cur, 2, right),
2388 -1, rrecs);
2389
2390 xfs_btree_log_keys(cur, rbp, 1, rrecs);
2391 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2392 } else {
2393 /* It's a leaf. operate on records */
2394 xfs_btree_shift_recs(cur,
2395 xfs_btree_rec_addr(cur, 2, right),
2396 -1, rrecs);
2397 xfs_btree_log_recs(cur, rbp, 1, rrecs);
687b890a
CH		 2398 }
2399
2c813ad6
DW		 2400 /*
2401 * Using a temporary cursor, update the parent key values of the
2402 * block on the left.
2403 */
c1d22ae8
DW		 2404 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2405 error = xfs_btree_dup_cursor(cur, &tcur);
2406 if (error)
2407 goto error0;
2408 i = xfs_btree_firstrec(tcur, level);
2409 XFS_WANT_CORRUPTED_GOTO(tcur->bc_mp, i == 1, error0);
2c813ad6 2410
c1d22ae8
DW		 2411 error = xfs_btree_decrement(tcur, level, &i);
2412 if (error)
2413 goto error1;
2c813ad6 2414
c1d22ae8 2415 /* Update the parent high keys of the left block, if needed. */
973b8319 2416 error = xfs_btree_update_keys(tcur, level);
2c813ad6
DW		 2417 if (error)
2418 goto error1;
c1d22ae8
DW		 2419
2420 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
2c813ad6
DW		 2421 }
2422
c1d22ae8
DW		 2423 /* Update the parent keys of the right block. */
2424 error = xfs_btree_update_keys(cur, level);
2425 if (error)
2426 goto error0;
687b890a
CH		 2427
2428 /* Slide the cursor value left one. */
2429 cur->bc_ptrs[level]--;
2430
2431 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2432 *stat = 1;
2433 return 0;
2434
2435out0:
2436 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2437 *stat = 0;
2438 return 0;
2439
2440error0:
2441 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2442 return error;
2c813ad6
DW		 2443
2444error1:
2445 XFS_BTREE_TRACE_CURSOR(tcur, XBT_ERROR);
2446 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
2447 return error;
687b890a
CH		 2448}
2449
9eaead51
CH		 2450/*
2451 * Move 1 record right from cur/level if possible.
2452 * Update cur to reflect the new path.
2453 */
3cc7524c 2454STATIC int /* error */
9eaead51
CH		 2455xfs_btree_rshift(
2456 struct xfs_btree_cur *cur,
2457 int level,
2458 int *stat) /* success/failure */
2459{
9eaead51
CH		 2460 struct xfs_buf *lbp; /* left buffer pointer */
2461 struct xfs_btree_block *left; /* left btree block */
2462 struct xfs_buf *rbp; /* right buffer pointer */
2463 struct xfs_btree_block *right; /* right btree block */
2464 struct xfs_btree_cur *tcur; /* temporary btree cursor */
2465 union xfs_btree_ptr rptr; /* right block pointer */
2466 union xfs_btree_key *rkp; /* right btree key */
2467 int rrecs; /* right record count */
2468 int lrecs; /* left record count */
2469 int error; /* error return value */
2470 int i; /* loop counter */
2471
2472 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2473 XFS_BTREE_TRACE_ARGI(cur, level);
2474
2475 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2476 (level == cur->bc_nlevels - 1))
2477 goto out0;
2478
2479 /* Set up variables for this block as "left". */
2480 left = xfs_btree_get_block(cur, level, &lbp);
2481
2482#ifdef DEBUG
2483 error = xfs_btree_check_block(cur, left, level, lbp);
2484 if (error)
2485 goto error0;
2486#endif
2487
2488 /* If we've got no right sibling then we can't shift an entry right. */
2489 xfs_btree_get_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2490 if (xfs_btree_ptr_is_null(cur, &rptr))
2491 goto out0;
2492
2493 /*
2494 * If the cursor entry is the one that would be moved, don't
2495 * do it... it's too complicated.
2496 */
2497 lrecs = xfs_btree_get_numrecs(left);
2498 if (cur->bc_ptrs[level] >= lrecs)
2499 goto out0;
2500
2501 /* Set up the right neighbor as "right". */
0d7409b1 2502 error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
9eaead51
CH		 2503 if (error)
2504 goto error0;
2505
2506 /* If it's full, it can't take another entry. */
2507 rrecs = xfs_btree_get_numrecs(right);
2508 if (rrecs == cur->bc_ops->get_maxrecs(cur, level))
2509 goto out0;
2510
2511 XFS_BTREE_STATS_INC(cur, rshift);
2512 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2513
2514 /*
2515 * Make a hole at the start of the right neighbor block, then
2516 * copy the last left block entry to the hole.
2517 */
2518 if (level > 0) {
2519 /* It's a nonleaf. make a hole in the keys and ptrs */
2520 union xfs_btree_key *lkp;
2521 union xfs_btree_ptr *lpp;
2522 union xfs_btree_ptr *rpp;
2523
2524 lkp = xfs_btree_key_addr(cur, lrecs, left);
2525 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2526 rkp = xfs_btree_key_addr(cur, 1, right);
2527 rpp = xfs_btree_ptr_addr(cur, 1, right);
2528
2529#ifdef DEBUG
2530 for (i = rrecs - 1; i >= 0; i--) {
2531 error = xfs_btree_check_ptr(cur, rpp, i, level);
2532 if (error)
2533 goto error0;
2534 }
2535#endif
2536
2537 xfs_btree_shift_keys(cur, rkp, 1, rrecs);
2538 xfs_btree_shift_ptrs(cur, rpp, 1, rrecs);
2539
2540#ifdef DEBUG
2541 error = xfs_btree_check_ptr(cur, lpp, 0, level);
2542 if (error)
2543 goto error0;
2544#endif
2545
2546 /* Now put the new data in, and log it. */
2547 xfs_btree_copy_keys(cur, rkp, lkp, 1);
2548 xfs_btree_copy_ptrs(cur, rpp, lpp, 1);
2549
2550 xfs_btree_log_keys(cur, rbp, 1, rrecs + 1);
2551 xfs_btree_log_ptrs(cur, rbp, 1, rrecs + 1);
2552
4a26e66e
CH		 2553 ASSERT(cur->bc_ops->keys_inorder(cur, rkp,
2554 xfs_btree_key_addr(cur, 2, right)));
9eaead51
CH		 2555 } else {
2556 /* It's a leaf. make a hole in the records */
2557 union xfs_btree_rec *lrp;
2558 union xfs_btree_rec *rrp;
2559
2560 lrp = xfs_btree_rec_addr(cur, lrecs, left);
2561 rrp = xfs_btree_rec_addr(cur, 1, right);
2562
2563 xfs_btree_shift_recs(cur, rrp, 1, rrecs);
2564
2565 /* Now put the new data in, and log it. */
2566 xfs_btree_copy_recs(cur, rrp, lrp, 1);
2567 xfs_btree_log_recs(cur, rbp, 1, rrecs + 1);
9eaead51
CH		 2568 }
2569
2570 /*
2571 * Decrement and log left's numrecs, bump and log right's numrecs.
2572 */
2573 xfs_btree_set_numrecs(left, --lrecs);
2574 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2575
2576 xfs_btree_set_numrecs(right, ++rrecs);
2577 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2578
2579 /*
2580 * Using a temporary cursor, update the parent key values of the
2581 * block on the right.
2582 */
2583 error = xfs_btree_dup_cursor(cur, &tcur);
2584 if (error)
2585 goto error0;
2586 i = xfs_btree_lastrec(tcur, level);
c1d22ae8 2587 XFS_WANT_CORRUPTED_GOTO(tcur->bc_mp, i == 1, error0);
9eaead51
CH		 2588
2589 error = xfs_btree_increment(tcur, level, &i);
2590 if (error)
2591 goto error1;
2592
2c813ad6
DW		 2593 /* Update the parent high keys of the left block, if needed. */
2594 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
973b8319 2595 error = xfs_btree_update_keys(cur, level);
2c813ad6
DW		 2596 if (error)
2597 goto error1;
2598 }
2599
70b22659 2600 /* Update the parent keys of the right block. */
973b8319 2601 error = xfs_btree_update_keys(tcur, level);
9eaead51
CH		 2602 if (error)
2603 goto error1;
2604
2605 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
2606
2607 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2608 *stat = 1;
2609 return 0;
2610
2611out0:
2612 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2613 *stat = 0;
2614 return 0;
2615
2616error0:
2617 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2618 return error;
2619
2620error1:
2621 XFS_BTREE_TRACE_CURSOR(tcur, XBT_ERROR);
2622 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
2623 return error;
2624}
f5eb8e7c
CH		 2625
2626/*
2627 * Split cur/level block in half.
2628 * Return new block number and the key to its first
2629 * record (to be inserted into parent).
2630 */
3cc7524c 2631STATIC int /* error */
cf11da9c 2632__xfs_btree_split(
f5eb8e7c
CH		 2633 struct xfs_btree_cur *cur,
2634 int level,
2635 union xfs_btree_ptr *ptrp,
2636 union xfs_btree_key *key,
2637 struct xfs_btree_cur **curp,
2638 int *stat) /* success/failure */
2639{
2640 union xfs_btree_ptr lptr; /* left sibling block ptr */
2641 struct xfs_buf *lbp; /* left buffer pointer */
2642 struct xfs_btree_block *left; /* left btree block */
2643 union xfs_btree_ptr rptr; /* right sibling block ptr */
2644 struct xfs_buf *rbp; /* right buffer pointer */
2645 struct xfs_btree_block *right; /* right btree block */
2646 union xfs_btree_ptr rrptr; /* right-right sibling ptr */
2647 struct xfs_buf *rrbp; /* right-right buffer pointer */
2648 struct xfs_btree_block *rrblock; /* right-right btree block */
2649 int lrecs;
2650 int rrecs;
2651 int src_index;
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_ARGIPK(cur, level, *ptrp, key);
2659
2660 XFS_BTREE_STATS_INC(cur, split);
2661
2662 /* Set up left block (current one). */
2663 left = xfs_btree_get_block(cur, level, &lbp);
2664
2665#ifdef DEBUG
2666 error = xfs_btree_check_block(cur, left, level, lbp);
2667 if (error)
2668 goto error0;
2669#endif
2670
2671 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2672
2673 /* Allocate the new block. If we can't do it, we're toast. Give up. */
6f8950cd 2674 error = cur->bc_ops->alloc_block(cur, &lptr, &rptr, stat);
f5eb8e7c
CH		 2675 if (error)
2676 goto error0;
2677 if (*stat == 0)
2678 goto out0;
2679 XFS_BTREE_STATS_INC(cur, alloc);
2680
2681 /* Set up the new block as "right". */
2682 error = xfs_btree_get_buf_block(cur, &rptr, 0, &right, &rbp);
2683 if (error)
2684 goto error0;
2685
2686 /* Fill in the btree header for the new right block. */
ee1a47ab 2687 xfs_btree_init_block_cur(cur, rbp, xfs_btree_get_level(left), 0);
f5eb8e7c
CH		 2688
2689 /*
2690 * Split the entries between the old and the new block evenly.
2691 * Make sure that if there's an odd number of entries now, that
2692 * each new block will have the same number of entries.
2693 */
2694 lrecs = xfs_btree_get_numrecs(left);
2695 rrecs = lrecs / 2;
2696 if ((lrecs & 1) && cur->bc_ptrs[level] <= rrecs + 1)
2697 rrecs++;
2698 src_index = (lrecs - rrecs + 1);
2699
2700 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2701
70b22659
DW		 2702 /* Adjust numrecs for the later get_*_keys() calls. */
2703 lrecs -= rrecs;
2704 xfs_btree_set_numrecs(left, lrecs);
2705 xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs);
2706
f5eb8e7c
CH		 2707 /*
2708 * Copy btree block entries from the left block over to the
2709 * new block, the right. Update the right block and log the
2710 * changes.
2711 */
2712 if (level > 0) {
2713 /* It's a non-leaf. Move keys and pointers. */
2714 union xfs_btree_key *lkp; /* left btree key */
2715 union xfs_btree_ptr *lpp; /* left address pointer */
2716 union xfs_btree_key *rkp; /* right btree key */
2717 union xfs_btree_ptr *rpp; /* right address pointer */
2718
2719 lkp = xfs_btree_key_addr(cur, src_index, left);
2720 lpp = xfs_btree_ptr_addr(cur, src_index, left);
2721 rkp = xfs_btree_key_addr(cur, 1, right);
2722 rpp = xfs_btree_ptr_addr(cur, 1, right);
2723
2724#ifdef DEBUG
2725 for (i = src_index; i < rrecs; i++) {
2726 error = xfs_btree_check_ptr(cur, lpp, i, level);
2727 if (error)
2728 goto error0;
2729 }
2730#endif
2731
70b22659 2732 /* Copy the keys & pointers to the new block. */
f5eb8e7c
CH		 2733 xfs_btree_copy_keys(cur, rkp, lkp, rrecs);
2734 xfs_btree_copy_ptrs(cur, rpp, lpp, rrecs);
2735
2736 xfs_btree_log_keys(cur, rbp, 1, rrecs);
2737 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2738
70b22659 2739 /* Stash the keys of the new block for later insertion. */
973b8319 2740 xfs_btree_get_node_keys(cur, right, key);
f5eb8e7c
CH		 2741 } else {
2742 /* It's a leaf. Move records. */
2743 union xfs_btree_rec *lrp; /* left record pointer */
2744 union xfs_btree_rec *rrp; /* right record pointer */
2745
2746 lrp = xfs_btree_rec_addr(cur, src_index, left);
2747 rrp = xfs_btree_rec_addr(cur, 1, right);
2748
70b22659 2749 /* Copy records to the new block. */
f5eb8e7c
CH		 2750 xfs_btree_copy_recs(cur, rrp, lrp, rrecs);
2751 xfs_btree_log_recs(cur, rbp, 1, rrecs);
2752
70b22659 2753 /* Stash the keys of the new block for later insertion. */
973b8319 2754 xfs_btree_get_leaf_keys(cur, right, key);
f5eb8e7c
CH		 2755 }
2756
f5eb8e7c
CH		 2757 /*
2758 * Find the left block number by looking in the buffer.
70b22659 2759 * Adjust sibling pointers.
f5eb8e7c
CH		 2760 */
2761 xfs_btree_get_sibling(cur, left, &rrptr, XFS_BB_RIGHTSIB);
2762 xfs_btree_set_sibling(cur, right, &rrptr, XFS_BB_RIGHTSIB);
2763 xfs_btree_set_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2764 xfs_btree_set_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2765
f5eb8e7c
CH		 2766 xfs_btree_log_block(cur, rbp, XFS_BB_ALL_BITS);
2767 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
2768
2769 /*
2770 * If there's a block to the new block's right, make that block
2771 * point back to right instead of to left.
2772 */
2773 if (!xfs_btree_ptr_is_null(cur, &rrptr)) {
0d7409b1 2774 error = xfs_btree_read_buf_block(cur, &rrptr,
f5eb8e7c
CH		 2775 0, &rrblock, &rrbp);
2776 if (error)
2777 goto error0;
2778 xfs_btree_set_sibling(cur, rrblock, &rptr, XFS_BB_LEFTSIB);
2779 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
2780 }
2c813ad6
DW		 2781
2782 /* Update the parent high keys of the left block, if needed. */
2783 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
973b8319 2784 error = xfs_btree_update_keys(cur, level);
2c813ad6
DW		 2785 if (error)
2786 goto error0;
2787 }
2788
f5eb8e7c
CH		 2789 /*
2790 * If the cursor is really in the right block, move it there.
2791 * If it's just pointing past the last entry in left, then we'll
2792 * insert there, so don't change anything in that case.
2793 */
2794 if (cur->bc_ptrs[level] > lrecs + 1) {
2795 xfs_btree_setbuf(cur, level, rbp);
2796 cur->bc_ptrs[level] -= lrecs;
2797 }
2798 /*
2799 * If there are more levels, we'll need another cursor which refers
2800 * the right block, no matter where this cursor was.
2801 */
2802 if (level + 1 < cur->bc_nlevels) {
2803 error = xfs_btree_dup_cursor(cur, curp);
2804 if (error)
2805 goto error0;
2806 (*curp)->bc_ptrs[level + 1]++;
2807 }
2808 *ptrp = rptr;
2809 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2810 *stat = 1;
2811 return 0;
2812out0:
2813 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2814 *stat = 0;
2815 return 0;
2816
2817error0:
2818 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2819 return error;
2820}
344207ce 2821
cf11da9c
DC		 2822struct xfs_btree_split_args {
2823 struct xfs_btree_cur *cur;
2824 int level;
2825 union xfs_btree_ptr *ptrp;
2826 union xfs_btree_key *key;
2827 struct xfs_btree_cur **curp;
2828 int *stat; /* success/failure */
2829 int result;
2830 bool kswapd; /* allocation in kswapd context */
2831 struct completion *done;
2832 struct work_struct work;
2833};
2834
2835/*
2836 * Stack switching interfaces for allocation
2837 */
2838static void
2839xfs_btree_split_worker(
2840 struct work_struct *work)
2841{
2842 struct xfs_btree_split_args *args = container_of(work,
2843 struct xfs_btree_split_args, work);
2844 unsigned long pflags;
2845 unsigned long new_pflags = PF_FSTRANS;
2846
2847 /*
2848 * we are in a transaction context here, but may also be doing work
2849 * in kswapd context, and hence we may need to inherit that state
2850 * temporarily to ensure that we don't block waiting for memory reclaim
2851 * in any way.
2852 */
2853 if (args->kswapd)
2854 new_pflags |= PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD;
2855
2856 current_set_flags_nested(&pflags, new_pflags);
2857
2858 args->result = __xfs_btree_split(args->cur, args->level, args->ptrp,
2859 args->key, args->curp, args->stat);
2860 complete(args->done);
2861
2862 current_restore_flags_nested(&pflags, new_pflags);
2863}
2864
2865/*
2866 * BMBT split requests often come in with little stack to work on. Push
2867 * them off to a worker thread so there is lots of stack to use. For the other
2868 * btree types, just call directly to avoid the context switch overhead here.
2869 */
2870STATIC int /* error */
2871xfs_btree_split(
2872 struct xfs_btree_cur *cur,
2873 int level,
2874 union xfs_btree_ptr *ptrp,
2875 union xfs_btree_key *key,
2876 struct xfs_btree_cur **curp,
2877 int *stat) /* success/failure */
2878{
2879 struct xfs_btree_split_args args;
2880 DECLARE_COMPLETION_ONSTACK(done);
2881
2882 if (cur->bc_btnum != XFS_BTNUM_BMAP)
2883 return __xfs_btree_split(cur, level, ptrp, key, curp, stat);
2884
2885 args.cur = cur;
2886 args.level = level;
2887 args.ptrp = ptrp;
2888 args.key = key;
2889 args.curp = curp;
2890 args.stat = stat;
2891 args.done = &done;
2892 args.kswapd = current_is_kswapd();
2893 INIT_WORK_ONSTACK(&args.work, xfs_btree_split_worker);
2894 queue_work(xfs_alloc_wq, &args.work);
2895 wait_for_completion(&done);
2896 destroy_work_on_stack(&args.work);
2897 return args.result;
2898}
2899
2900
ea77b0a6
CH		 2901/*
2902 * Copy the old inode root contents into a real block and make the
2903 * broot point to it.
2904 */
2905int /* error */
2906xfs_btree_new_iroot(
2907 struct xfs_btree_cur *cur, /* btree cursor */
2908 int *logflags, /* logging flags for inode */
2909 int *stat) /* return status - 0 fail */
2910{
2911 struct xfs_buf *cbp; /* buffer for cblock */
2912 struct xfs_btree_block *block; /* btree block */
2913 struct xfs_btree_block *cblock; /* child btree block */
2914 union xfs_btree_key *ckp; /* child key pointer */
2915 union xfs_btree_ptr *cpp; /* child ptr pointer */
2916 union xfs_btree_key *kp; /* pointer to btree key */
2917 union xfs_btree_ptr *pp; /* pointer to block addr */
2918 union xfs_btree_ptr nptr; /* new block addr */
2919 int level; /* btree level */
2920 int error; /* error return code */
2921#ifdef DEBUG
2922 int i; /* loop counter */
2923#endif
2924
2925 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2926 XFS_BTREE_STATS_INC(cur, newroot);
2927
2928 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
2929
2930 level = cur->bc_nlevels - 1;
2931
2932 block = xfs_btree_get_iroot(cur);
2933 pp = xfs_btree_ptr_addr(cur, 1, block);
2934
2935 /* Allocate the new block. If we can't do it, we're toast. Give up. */
6f8950cd 2936 error = cur->bc_ops->alloc_block(cur, pp, &nptr, stat);
ea77b0a6
CH		 2937 if (error)
2938 goto error0;
2939 if (*stat == 0) {
2940 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2941 return 0;
2942 }
2943 XFS_BTREE_STATS_INC(cur, alloc);
2944
2945 /* Copy the root into a real block. */
2946 error = xfs_btree_get_buf_block(cur, &nptr, 0, &cblock, &cbp);
2947 if (error)
2948 goto error0;
2949
088c9f67
DC		 2950 /*
2951 * we can't just memcpy() the root in for CRC enabled btree blocks.
2952 * In that case have to also ensure the blkno remains correct
2953 */
ea77b0a6 2954 memcpy(cblock, block, xfs_btree_block_len(cur));
088c9f67
DC		 2955 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) {
2956 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
2957 cblock->bb_u.l.bb_blkno = cpu_to_be64(cbp->b_bn);
2958 else
2959 cblock->bb_u.s.bb_blkno = cpu_to_be64(cbp->b_bn);
2960 }
ea77b0a6
CH		 2961
2962 be16_add_cpu(&block->bb_level, 1);
2963 xfs_btree_set_numrecs(block, 1);
2964 cur->bc_nlevels++;
2965 cur->bc_ptrs[level + 1] = 1;
2966
2967 kp = xfs_btree_key_addr(cur, 1, block);
2968 ckp = xfs_btree_key_addr(cur, 1, cblock);
2969 xfs_btree_copy_keys(cur, ckp, kp, xfs_btree_get_numrecs(cblock));
2970
2971 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
2972#ifdef DEBUG
2973 for (i = 0; i < be16_to_cpu(cblock->bb_numrecs); i++) {
2974 error = xfs_btree_check_ptr(cur, pp, i, level);
2975 if (error)
2976 goto error0;
2977 }
2978#endif
2979 xfs_btree_copy_ptrs(cur, cpp, pp, xfs_btree_get_numrecs(cblock));
2980
2981#ifdef DEBUG
2982 error = xfs_btree_check_ptr(cur, &nptr, 0, level);
2983 if (error)
2984 goto error0;
2985#endif
2986 xfs_btree_copy_ptrs(cur, pp, &nptr, 1);
2987
2988 xfs_iroot_realloc(cur->bc_private.b.ip,
2989 1 - xfs_btree_get_numrecs(cblock),
2990 cur->bc_private.b.whichfork);
2991
2992 xfs_btree_setbuf(cur, level, cbp);
2993
2994 /*
2995 * Do all this logging at the end so that
2996 * the root is at the right level.
2997 */
2998 xfs_btree_log_block(cur, cbp, XFS_BB_ALL_BITS);
2999 xfs_btree_log_keys(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
3000 xfs_btree_log_ptrs(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
3001
3002 *logflags |=
9d87c319 3003 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork);
ea77b0a6
CH		 3004 *stat = 1;
3005 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3006 return 0;
3007error0:
3008 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3009 return error;
3010}
3011
344207ce
CH		 3012/*
3013 * Allocate a new root block, fill it in.
3014 */
3cc7524c 3015STATIC int /* error */
344207ce
CH		 3016xfs_btree_new_root(
3017 struct xfs_btree_cur *cur, /* btree cursor */
3018 int *stat) /* success/failure */
3019{
3020 struct xfs_btree_block *block; /* one half of the old root block */
3021 struct xfs_buf *bp; /* buffer containing block */
3022 int error; /* error return value */
3023 struct xfs_buf *lbp; /* left buffer pointer */
3024 struct xfs_btree_block *left; /* left btree block */
3025 struct xfs_buf *nbp; /* new (root) buffer */
3026 struct xfs_btree_block *new; /* new (root) btree block */
3027 int nptr; /* new value for key index, 1 or 2 */
3028 struct xfs_buf *rbp; /* right buffer pointer */
3029 struct xfs_btree_block *right; /* right btree block */
3030 union xfs_btree_ptr rptr;
3031 union xfs_btree_ptr lptr;
3032
3033 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3034 XFS_BTREE_STATS_INC(cur, newroot);
3035
3036 /* initialise our start point from the cursor */
3037 cur->bc_ops->init_ptr_from_cur(cur, &rptr);
3038
3039 /* Allocate the new block. If we can't do it, we're toast. Give up. */
6f8950cd 3040 error = cur->bc_ops->alloc_block(cur, &rptr, &lptr, stat);
344207ce
CH		 3041 if (error)
3042 goto error0;
3043 if (*stat == 0)
3044 goto out0;
3045 XFS_BTREE_STATS_INC(cur, alloc);
3046
3047 /* Set up the new block. */
3048 error = xfs_btree_get_buf_block(cur, &lptr, 0, &new, &nbp);
3049 if (error)
3050 goto error0;
3051
3052 /* Set the root in the holding structure increasing the level by 1. */
3053 cur->bc_ops->set_root(cur, &lptr, 1);
3054
3055 /*
3056 * At the previous root level there are now two blocks: the old root,
3057 * and the new block generated when it was split. We don't know which
3058 * one the cursor is pointing at, so we set up variables "left" and
3059 * "right" for each case.
3060 */
3061 block = xfs_btree_get_block(cur, cur->bc_nlevels - 1, &bp);
3062
3063#ifdef DEBUG
3064 error = xfs_btree_check_block(cur, block, cur->bc_nlevels - 1, bp);
3065 if (error)
3066 goto error0;
3067#endif
3068
3069 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
3070 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
3071 /* Our block is left, pick up the right block. */
3072 lbp = bp;
3073 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
3074 left = block;
0d7409b1 3075 error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
344207ce
CH		 3076 if (error)
3077 goto error0;
3078 bp = rbp;
3079 nptr = 1;
3080 } else {
3081 /* Our block is right, pick up the left block. */
3082 rbp = bp;
3083 xfs_btree_buf_to_ptr(cur, rbp, &rptr);
3084 right = block;
3085 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
0d7409b1 3086 error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
344207ce
CH		 3087 if (error)
3088 goto error0;
3089 bp = lbp;
3090 nptr = 2;
3091 }
70b22659 3092
344207ce 3093 /* Fill in the new block's btree header and log it. */
ee1a47ab 3094 xfs_btree_init_block_cur(cur, nbp, cur->bc_nlevels, 2);
344207ce
CH		 3095 xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS);
3096 ASSERT(!xfs_btree_ptr_is_null(cur, &lptr) &&
3097 !xfs_btree_ptr_is_null(cur, &rptr));
3098
3099 /* Fill in the key data in the new root. */
3100 if (xfs_btree_get_level(left) > 0) {
70b22659
DW		 3101 /*
3102 * Get the keys for the left block's keys and put them directly
3103 * in the parent block. Do the same for the right block.
3104 */
973b8319 3105 xfs_btree_get_node_keys(cur, left,
70b22659 3106 xfs_btree_key_addr(cur, 1, new));
973b8319 3107 xfs_btree_get_node_keys(cur, right,
70b22659 3108 xfs_btree_key_addr(cur, 2, new));
344207ce 3109 } else {
70b22659
DW		 3110 /*
3111 * Get the keys for the left block's records and put them
3112 * directly in the parent block. Do the same for the right
3113 * block.
3114 */
973b8319 3115 xfs_btree_get_leaf_keys(cur, left,
70b22659 3116 xfs_btree_key_addr(cur, 1, new));
973b8319 3117 xfs_btree_get_leaf_keys(cur, right,
70b22659 3118 xfs_btree_key_addr(cur, 2, new));
344207ce
CH		 3119 }
3120 xfs_btree_log_keys(cur, nbp, 1, 2);
3121
3122 /* Fill in the pointer data in the new root. */
3123 xfs_btree_copy_ptrs(cur,
3124 xfs_btree_ptr_addr(cur, 1, new), &lptr, 1);
3125 xfs_btree_copy_ptrs(cur,
3126 xfs_btree_ptr_addr(cur, 2, new), &rptr, 1);
3127 xfs_btree_log_ptrs(cur, nbp, 1, 2);
3128
3129 /* Fix up the cursor. */
3130 xfs_btree_setbuf(cur, cur->bc_nlevels, nbp);
3131 cur->bc_ptrs[cur->bc_nlevels] = nptr;
3132 cur->bc_nlevels++;
3133 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3134 *stat = 1;
3135 return 0;
3136error0:
3137 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3138 return error;
3139out0:
3140 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3141 *stat = 0;
3142 return 0;
3143}
4b22a571
CH		 3144
3145STATIC int
3146xfs_btree_make_block_unfull(
3147 struct xfs_btree_cur *cur, /* btree cursor */
3148 int level, /* btree level */
3149 int numrecs,/* # of recs in block */
3150 int *oindex,/* old tree index */
3151 int *index, /* new tree index */
3152 union xfs_btree_ptr *nptr, /* new btree ptr */
3153 struct xfs_btree_cur **ncur, /* new btree cursor */
70b22659 3154 union xfs_btree_key *key, /* key of new block */
4b22a571
CH		 3155 int *stat)
3156{
4b22a571
CH		 3157 int error = 0;
3158
3159 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
3160 level == cur->bc_nlevels - 1) {
3161 struct xfs_inode *ip = cur->bc_private.b.ip;
3162
3163 if (numrecs < cur->bc_ops->get_dmaxrecs(cur, level)) {
3164 /* A root block that can be made bigger. */
4b22a571 3165 xfs_iroot_realloc(ip, 1, cur->bc_private.b.whichfork);
0d309791 3166 *stat = 1;
4b22a571
CH		 3167 } else {
3168 /* A root block that needs replacing */
3169 int logflags = 0;
3170
3171 error = xfs_btree_new_iroot(cur, &logflags, stat);
3172 if (error || *stat == 0)
3173 return error;
3174
3175 xfs_trans_log_inode(cur->bc_tp, ip, logflags);
3176 }
3177
3178 return 0;
3179 }
3180
3181 /* First, try shifting an entry to the right neighbor. */
3182 error = xfs_btree_rshift(cur, level, stat);
3183 if (error || *stat)
3184 return error;
3185
3186 /* Next, try shifting an entry to the left neighbor. */
3187 error = xfs_btree_lshift(cur, level, stat);
3188 if (error)
3189 return error;
3190
3191 if (*stat) {
3192 *oindex = *index = cur->bc_ptrs[level];
3193 return 0;
3194 }
3195
3196 /*
3197 * Next, try splitting the current block in half.
3198 *
3199 * If this works we have to re-set our variables because we
3200 * could be in a different block now.
3201 */
e5821e57 3202 error = xfs_btree_split(cur, level, nptr, key, ncur, stat);
4b22a571
CH		 3203 if (error || *stat == 0)
3204 return error;
3205
3206
3207 *index = cur->bc_ptrs[level];
4b22a571
CH		 3208 return 0;
3209}
3210
3211/*
3212 * Insert one record/level. Return information to the caller
3213 * allowing the next level up to proceed if necessary.
3214 */
3215STATIC int
3216xfs_btree_insrec(
3217 struct xfs_btree_cur *cur, /* btree cursor */
3218 int level, /* level to insert record at */
3219 union xfs_btree_ptr *ptrp, /* i/o: block number inserted */
e5821e57
DW		 3220 union xfs_btree_rec *rec, /* record to insert */
3221 union xfs_btree_key *key, /* i/o: block key for ptrp */
4b22a571
CH		 3222 struct xfs_btree_cur **curp, /* output: new cursor replacing cur */
3223 int *stat) /* success/failure */
3224{
3225 struct xfs_btree_block *block; /* btree block */
3226 struct xfs_buf *bp; /* buffer for block */
4b22a571
CH		 3227 union xfs_btree_ptr nptr; /* new block ptr */
3228 struct xfs_btree_cur *ncur; /* new btree cursor */
2c813ad6
DW		 3229 union xfs_btree_bigkey nkey; /* new block key */
3230 union xfs_btree_key *lkey;
4b22a571
CH		 3231 int optr; /* old key/record index */
3232 int ptr; /* key/record index */
3233 int numrecs;/* number of records */
3234 int error; /* error return value */
3235#ifdef DEBUG
3236 int i;
3237#endif
2c813ad6 3238 xfs_daddr_t old_bn;
4b22a571
CH		 3239
3240 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
e5821e57 3241 XFS_BTREE_TRACE_ARGIPR(cur, level, *ptrp, &rec);
4b22a571
CH		 3242
3243 ncur = NULL;
2c813ad6 3244 lkey = (union xfs_btree_key *)&nkey;
4b22a571
CH		 3245
3246 /*
3247 * If we have an external root pointer, and we've made it to the
3248 * root level, allocate a new root block and we're done.
3249 */
3250 if (!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
3251 (level >= cur->bc_nlevels)) {
3252 error = xfs_btree_new_root(cur, stat);
3253 xfs_btree_set_ptr_null(cur, ptrp);
3254
3255 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3256 return error;
3257 }
3258
3259 /* If we're off the left edge, return failure. */
3260 ptr = cur->bc_ptrs[level];
3261 if (ptr == 0) {
3262 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3263 *stat = 0;
3264 return 0;
3265 }
3266
4b22a571
CH		 3267 optr = ptr;
3268
3269 XFS_BTREE_STATS_INC(cur, insrec);
3270
3271 /* Get pointers to the btree buffer and block. */
3272 block = xfs_btree_get_block(cur, level, &bp);
2c813ad6 3273 old_bn = bp ? bp->b_bn : XFS_BUF_DADDR_NULL;
4b22a571
CH		 3274 numrecs = xfs_btree_get_numrecs(block);
3275
3276#ifdef DEBUG
3277 error = xfs_btree_check_block(cur, block, level, bp);
3278 if (error)
3279 goto error0;
3280
3281 /* Check that the new entry is being inserted in the right place. */
3282 if (ptr <= numrecs) {
3283 if (level == 0) {
e5821e57 3284 ASSERT(cur->bc_ops->recs_inorder(cur, rec,
4a26e66e 3285 xfs_btree_rec_addr(cur, ptr, block)));
4b22a571 3286 } else {
e5821e57 3287 ASSERT(cur->bc_ops->keys_inorder(cur, key,
4a26e66e 3288 xfs_btree_key_addr(cur, ptr, block)));
4b22a571
CH		 3289 }
3290 }
3291#endif
3292
3293 /*
3294 * If the block is full, we can't insert the new entry until we
3295 * make the block un-full.
3296 */
3297 xfs_btree_set_ptr_null(cur, &nptr);
3298 if (numrecs == cur->bc_ops->get_maxrecs(cur, level)) {
3299 error = xfs_btree_make_block_unfull(cur, level, numrecs,
2c813ad6 3300 &optr, &ptr, &nptr, &ncur, lkey, stat);
4b22a571
CH		 3301 if (error || *stat == 0)
3302 goto error0;
3303 }
3304
3305 /*
3306 * The current block may have changed if the block was
3307 * previously full and we have just made space in it.
3308 */
3309 block = xfs_btree_get_block(cur, level, &bp);
3310 numrecs = xfs_btree_get_numrecs(block);
3311
3312#ifdef DEBUG
3313 error = xfs_btree_check_block(cur, block, level, bp);
3314 if (error)
3315 return error;
3316#endif
3317
3318 /*
3319 * At this point we know there's room for our new entry in the block
3320 * we're pointing at.
3321 */
3322 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr + 1);
3323
3324 if (level > 0) {
3325 /* It's a nonleaf. make a hole in the keys and ptrs */
3326 union xfs_btree_key *kp;
3327 union xfs_btree_ptr *pp;
3328
3329 kp = xfs_btree_key_addr(cur, ptr, block);
3330 pp = xfs_btree_ptr_addr(cur, ptr, block);
3331
3332#ifdef DEBUG
3333 for (i = numrecs - ptr; i >= 0; i--) {
3334 error = xfs_btree_check_ptr(cur, pp, i, level);
3335 if (error)
3336 return error;
3337 }
3338#endif
3339
3340 xfs_btree_shift_keys(cur, kp, 1, numrecs - ptr + 1);
3341 xfs_btree_shift_ptrs(cur, pp, 1, numrecs - ptr + 1);
3342
3343#ifdef DEBUG
3344 error = xfs_btree_check_ptr(cur, ptrp, 0, level);
3345 if (error)
3346 goto error0;
3347#endif
3348
3349 /* Now put the new data in, bump numrecs and log it. */
e5821e57 3350 xfs_btree_copy_keys(cur, kp, key, 1);
4b22a571
CH		 3351 xfs_btree_copy_ptrs(cur, pp, ptrp, 1);
3352 numrecs++;
3353 xfs_btree_set_numrecs(block, numrecs);
3354 xfs_btree_log_ptrs(cur, bp, ptr, numrecs);
3355 xfs_btree_log_keys(cur, bp, ptr, numrecs);
3356#ifdef DEBUG
3357 if (ptr < numrecs) {
4a26e66e
CH		 3358 ASSERT(cur->bc_ops->keys_inorder(cur, kp,
3359 xfs_btree_key_addr(cur, ptr + 1, block)));
4b22a571
CH		 3360 }
3361#endif
3362 } else {
3363 /* It's a leaf. make a hole in the records */
3364 union xfs_btree_rec *rp;
3365
3366 rp = xfs_btree_rec_addr(cur, ptr, block);
3367
3368 xfs_btree_shift_recs(cur, rp, 1, numrecs - ptr + 1);
3369
3370 /* Now put the new data in, bump numrecs and log it. */
e5821e57 3371 xfs_btree_copy_recs(cur, rp, rec, 1);
4b22a571
CH		 3372 xfs_btree_set_numrecs(block, ++numrecs);
3373 xfs_btree_log_recs(cur, bp, ptr, numrecs);
3374#ifdef DEBUG
3375 if (ptr < numrecs) {
4a26e66e
CH		 3376 ASSERT(cur->bc_ops->recs_inorder(cur, rp,
3377 xfs_btree_rec_addr(cur, ptr + 1, block)));
4b22a571
CH		 3378 }
3379#endif
3380 }
3381
3382 /* Log the new number of records in the btree header. */
3383 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
3384
2c813ad6
DW		 3385 /*
3386 * If we just inserted into a new tree block, we have to
3387 * recalculate nkey here because nkey is out of date.
3388 *
3389 * Otherwise we're just updating an existing block (having shoved
3390 * some records into the new tree block), so use the regular key
3391 * update mechanism.
3392 */
3393 if (bp && bp->b_bn != old_bn) {
3394 xfs_btree_get_keys(cur, block, lkey);
3395 } else if (xfs_btree_needs_key_update(cur, optr)) {
973b8319 3396 error = xfs_btree_update_keys(cur, level);
4b22a571
CH		 3397 if (error)
3398 goto error0;
3399 }
3400
3401 /*
3402 * If we are tracking the last record in the tree and
3403 * we are at the far right edge of the tree, update it.
3404 */
3405 if (xfs_btree_is_lastrec(cur, block, level)) {
e5821e57 3406 cur->bc_ops->update_lastrec(cur, block, rec,
4b22a571
CH		 3407 ptr, LASTREC_INSREC);
3408 }
3409
3410 /*
3411 * Return the new block number, if any.
3412 * If there is one, give back a record value and a cursor too.
3413 */
3414 *ptrp = nptr;
3415 if (!xfs_btree_ptr_is_null(cur, &nptr)) {
2c813ad6 3416 xfs_btree_copy_keys(cur, key, lkey, 1);
4b22a571
CH		 3417 *curp = ncur;
3418 }
3419
3420 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3421 *stat = 1;
3422 return 0;
3423
3424error0:
3425 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3426 return error;
3427}
3428
3429/*
3430 * Insert the record at the point referenced by cur.
3431 *
3432 * A multi-level split of the tree on insert will invalidate the original
3433 * cursor. All callers of this function should assume that the cursor is
3434 * no longer valid and revalidate it.
3435 */
3436int
3437xfs_btree_insert(
3438 struct xfs_btree_cur *cur,
3439 int *stat)
3440{
3441 int error; /* error return value */
3442 int i; /* result value, 0 for failure */
3443 int level; /* current level number in btree */
3444 union xfs_btree_ptr nptr; /* new block number (split result) */
3445 struct xfs_btree_cur *ncur; /* new cursor (split result) */
3446 struct xfs_btree_cur *pcur; /* previous level's cursor */
2c813ad6
DW		 3447 union xfs_btree_bigkey bkey; /* key of block to insert */
3448 union xfs_btree_key *key;
4b22a571
CH		 3449 union xfs_btree_rec rec; /* record to insert */
3450
3451 level = 0;
3452 ncur = NULL;
3453 pcur = cur;
2c813ad6 3454 key = (union xfs_btree_key *)&bkey;
4b22a571
CH		 3455
3456 xfs_btree_set_ptr_null(cur, &nptr);
e5821e57
DW		 3457
3458 /* Make a key out of the record data to be inserted, and save it. */
4b22a571 3459 cur->bc_ops->init_rec_from_cur(cur, &rec);
2c813ad6 3460 cur->bc_ops->init_key_from_rec(key, &rec);
4b22a571
CH		 3461
3462 /*
3463 * Loop going up the tree, starting at the leaf level.
3464 * Stop when we don't get a split block, that must mean that
3465 * the insert is finished with this level.
3466 */
3467 do {
3468 /*
3469 * Insert nrec/nptr into this level of the tree.
3470 * Note if we fail, nptr will be null.
3471 */
2c813ad6 3472 error = xfs_btree_insrec(pcur, level, &nptr, &rec, key,
e5821e57 3473 &ncur, &i);
4b22a571
CH		 3474 if (error) {
3475 if (pcur != cur)
3476 xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR);
3477 goto error0;
3478 }
3479
c29aad41 3480 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
4b22a571
CH		 3481 level++;
3482
3483 /*
3484 * See if the cursor we just used is trash.
3485 * Can't trash the caller's cursor, but otherwise we should
3486 * if ncur is a new cursor or we're about to be done.
3487 */
3488 if (pcur != cur &&
3489 (ncur || xfs_btree_ptr_is_null(cur, &nptr))) {
3490 /* Save the state from the cursor before we trash it */
3491 if (cur->bc_ops->update_cursor)
3492 cur->bc_ops->update_cursor(pcur, cur);
3493 cur->bc_nlevels = pcur->bc_nlevels;
3494 xfs_btree_del_cursor(pcur, XFS_BTREE_NOERROR);
3495 }
3496 /* If we got a new cursor, switch to it. */
3497 if (ncur) {
3498 pcur = ncur;
3499 ncur = NULL;
3500 }
3501 } while (!xfs_btree_ptr_is_null(cur, &nptr));
3502
3503 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3504 *stat = i;
3505 return 0;
3506error0:
3507 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3508 return error;
3509}
d4b3a4b7
CH		 3510
3511/*
3512 * Try to merge a non-leaf block back into the inode root.
3513 *
3514 * Note: the killroot names comes from the fact that we're effectively
3515 * killing the old root block. But because we can't just delete the
3516 * inode we have to copy the single block it was pointing to into the
3517 * inode.
3518 */
d96f8f89 3519STATIC int
d4b3a4b7
CH		 3520xfs_btree_kill_iroot(
3521 struct xfs_btree_cur *cur)
3522{
3523 int whichfork = cur->bc_private.b.whichfork;
3524 struct xfs_inode *ip = cur->bc_private.b.ip;
3525 struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork);
3526 struct xfs_btree_block *block;
3527 struct xfs_btree_block *cblock;
3528 union xfs_btree_key *kp;
3529 union xfs_btree_key *ckp;
3530 union xfs_btree_ptr *pp;
3531 union xfs_btree_ptr *cpp;
3532 struct xfs_buf *cbp;
3533 int level;
3534 int index;
3535 int numrecs;
196328ec 3536 int error;
d4b3a4b7
CH		 3537#ifdef DEBUG
3538 union xfs_btree_ptr ptr;
3539 int i;
3540#endif
3541
3542 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3543
3544 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
3545 ASSERT(cur->bc_nlevels > 1);
3546
3547 /*
3548 * Don't deal with the root block needs to be a leaf case.
3549 * We're just going to turn the thing back into extents anyway.
3550 */
3551 level = cur->bc_nlevels - 1;
3552 if (level == 1)
3553 goto out0;
3554
3555 /*
3556 * Give up if the root has multiple children.
3557 */
3558 block = xfs_btree_get_iroot(cur);
3559 if (xfs_btree_get_numrecs(block) != 1)
3560 goto out0;
3561
3562 cblock = xfs_btree_get_block(cur, level - 1, &cbp);
3563 numrecs = xfs_btree_get_numrecs(cblock);
3564
3565 /*
3566 * Only do this if the next level will fit.
3567 * Then the data must be copied up to the inode,
3568 * instead of freeing the root you free the next level.
3569 */
3570 if (numrecs > cur->bc_ops->get_dmaxrecs(cur, level))
3571 goto out0;
3572
3573 XFS_BTREE_STATS_INC(cur, killroot);
3574
3575#ifdef DEBUG
3576 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
3577 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
3578 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
3579 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
3580#endif
3581
3582 index = numrecs - cur->bc_ops->get_maxrecs(cur, level);
3583 if (index) {
3584 xfs_iroot_realloc(cur->bc_private.b.ip, index,
3585 cur->bc_private.b.whichfork);
7cc95a82 3586 block = ifp->if_broot;
d4b3a4b7
CH		 3587 }
3588
3589 be16_add_cpu(&block->bb_numrecs, index);
3590 ASSERT(block->bb_numrecs == cblock->bb_numrecs);
3591
3592 kp = xfs_btree_key_addr(cur, 1, block);
3593 ckp = xfs_btree_key_addr(cur, 1, cblock);
3594 xfs_btree_copy_keys(cur, kp, ckp, numrecs);
3595
3596 pp = xfs_btree_ptr_addr(cur, 1, block);
3597 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
3598#ifdef DEBUG
3599 for (i = 0; i < numrecs; i++) {
d4b3a4b7
CH		 3600 error = xfs_btree_check_ptr(cur, cpp, i, level - 1);
3601 if (error) {
3602 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3603 return error;
3604 }
3605 }
3606#endif
3607 xfs_btree_copy_ptrs(cur, pp, cpp, numrecs);
3608
c46ee8ad 3609 error = xfs_btree_free_block(cur, cbp);
196328ec
CH		 3610 if (error) {
3611 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3612 return error;
3613 }
d4b3a4b7
CH		 3614
3615 cur->bc_bufs[level - 1] = NULL;
3616 be16_add_cpu(&block->bb_level, -1);
3617 xfs_trans_log_inode(cur->bc_tp, ip,
9d87c319 3618 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork));
d4b3a4b7
CH		 3619 cur->bc_nlevels--;
3620out0:
3621 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3622 return 0;
3623}
91cca5df 3624
c0e59e1a
CH		 3625/*
3626 * Kill the current root node, and replace it with it's only child node.
3627 */
3628STATIC int
3629xfs_btree_kill_root(
3630 struct xfs_btree_cur *cur,
3631 struct xfs_buf *bp,
3632 int level,
3633 union xfs_btree_ptr *newroot)
3634{
3635 int error;
3636
3637 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3638 XFS_BTREE_STATS_INC(cur, killroot);
3639
3640 /*
3641 * Update the root pointer, decreasing the level by 1 and then
3642 * free the old root.
3643 */
3644 cur->bc_ops->set_root(cur, newroot, -1);
3645
c46ee8ad 3646 error = xfs_btree_free_block(cur, bp);
c0e59e1a
CH		 3647 if (error) {
3648 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3649 return error;
3650 }
3651
c0e59e1a
CH		 3652 cur->bc_bufs[level] = NULL;
3653 cur->bc_ra[level] = 0;
3654 cur->bc_nlevels--;
3655
3656 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3657 return 0;
3658}
3659
91cca5df
CH		 3660STATIC int
3661xfs_btree_dec_cursor(
3662 struct xfs_btree_cur *cur,
3663 int level,
3664 int *stat)
3665{
3666 int error;
3667 int i;
3668
3669 if (level > 0) {
3670 error = xfs_btree_decrement(cur, level, &i);
3671 if (error)
3672 return error;
3673 }
3674
3675 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3676 *stat = 1;
3677 return 0;
3678}
3679
3680/*
3681 * Single level of the btree record deletion routine.
3682 * Delete record pointed to by cur/level.
3683 * Remove the record from its block then rebalance the tree.
3684 * Return 0 for error, 1 for done, 2 to go on to the next level.
3685 */
3686STATIC int /* error */
3687xfs_btree_delrec(
3688 struct xfs_btree_cur *cur, /* btree cursor */
3689 int level, /* level removing record from */
3690 int *stat) /* fail/done/go-on */
3691{
3692 struct xfs_btree_block *block; /* btree block */
3693 union xfs_btree_ptr cptr; /* current block ptr */
3694 struct xfs_buf *bp; /* buffer for block */
3695 int error; /* error return value */
3696 int i; /* loop counter */
91cca5df
CH		 3697 union xfs_btree_ptr lptr; /* left sibling block ptr */
3698 struct xfs_buf *lbp; /* left buffer pointer */
3699 struct xfs_btree_block *left; /* left btree block */
3700 int lrecs = 0; /* left record count */
3701 int ptr; /* key/record index */
3702 union xfs_btree_ptr rptr; /* right sibling block ptr */
3703 struct xfs_buf *rbp; /* right buffer pointer */
3704 struct xfs_btree_block *right; /* right btree block */
3705 struct xfs_btree_block *rrblock; /* right-right btree block */
3706 struct xfs_buf *rrbp; /* right-right buffer pointer */
3707 int rrecs = 0; /* right record count */
3708 struct xfs_btree_cur *tcur; /* temporary btree cursor */
3709 int numrecs; /* temporary numrec count */
3710
3711 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3712 XFS_BTREE_TRACE_ARGI(cur, level);
3713
3714 tcur = NULL;
3715
3716 /* Get the index of the entry being deleted, check for nothing there. */
3717 ptr = cur->bc_ptrs[level];
3718 if (ptr == 0) {
3719 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3720 *stat = 0;
3721 return 0;
3722 }
3723
3724 /* Get the buffer & block containing the record or key/ptr. */
3725 block = xfs_btree_get_block(cur, level, &bp);
3726 numrecs = xfs_btree_get_numrecs(block);
3727
3728#ifdef DEBUG
3729 error = xfs_btree_check_block(cur, block, level, bp);
3730 if (error)
3731 goto error0;
3732#endif
3733
3734 /* Fail if we're off the end of the block. */
3735 if (ptr > numrecs) {
3736 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3737 *stat = 0;
3738 return 0;
3739 }
3740
3741 XFS_BTREE_STATS_INC(cur, delrec);
3742 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr);
3743
3744 /* Excise the entries being deleted. */
3745 if (level > 0) {
3746 /* It's a nonleaf. operate on keys and ptrs */
3747 union xfs_btree_key *lkp;
3748 union xfs_btree_ptr *lpp;
3749
3750 lkp = xfs_btree_key_addr(cur, ptr + 1, block);
3751 lpp = xfs_btree_ptr_addr(cur, ptr + 1, block);
3752
3753#ifdef DEBUG
3754 for (i = 0; i < numrecs - ptr; i++) {
3755 error = xfs_btree_check_ptr(cur, lpp, i, level);
3756 if (error)
3757 goto error0;
3758 }
3759#endif
3760
3761 if (ptr < numrecs) {
3762 xfs_btree_shift_keys(cur, lkp, -1, numrecs - ptr);
3763 xfs_btree_shift_ptrs(cur, lpp, -1, numrecs - ptr);
3764 xfs_btree_log_keys(cur, bp, ptr, numrecs - 1);
3765 xfs_btree_log_ptrs(cur, bp, ptr, numrecs - 1);
3766 }
91cca5df
CH		 3767 } else {
3768 /* It's a leaf. operate on records */
3769 if (ptr < numrecs) {
3770 xfs_btree_shift_recs(cur,
3771 xfs_btree_rec_addr(cur, ptr + 1, block),
3772 -1, numrecs - ptr);
3773 xfs_btree_log_recs(cur, bp, ptr, numrecs - 1);
3774 }
91cca5df
CH		 3775 }
3776
3777 /*
3778 * Decrement and log the number of entries in the block.
3779 */
3780 xfs_btree_set_numrecs(block, --numrecs);
3781 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
3782
3783 /*
3784 * If we are tracking the last record in the tree and
3785 * we are at the far right edge of the tree, update it.
3786 */
3787 if (xfs_btree_is_lastrec(cur, block, level)) {
3788 cur->bc_ops->update_lastrec(cur, block, NULL,
3789 ptr, LASTREC_DELREC);
3790 }
3791
3792 /*
3793 * We're at the root level. First, shrink the root block in-memory.
3794 * Try to get rid of the next level down. If we can't then there's
3795 * nothing left to do.
3796 */
3797 if (level == cur->bc_nlevels - 1) {
3798 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3799 xfs_iroot_realloc(cur->bc_private.b.ip, -1,
3800 cur->bc_private.b.whichfork);
3801
3802 error = xfs_btree_kill_iroot(cur);
3803 if (error)
3804 goto error0;
3805
3806 error = xfs_btree_dec_cursor(cur, level, stat);
3807 if (error)
3808 goto error0;
3809 *stat = 1;
3810 return 0;
3811 }
3812
3813 /*
3814 * If this is the root level, and there's only one entry left,
3815 * and it's NOT the leaf level, then we can get rid of this
3816 * level.
3817 */
3818 if (numrecs == 1 && level > 0) {
3819 union xfs_btree_ptr *pp;
3820 /*
3821 * pp is still set to the first pointer in the block.
3822 * Make it the new root of the btree.
3823 */
3824 pp = xfs_btree_ptr_addr(cur, 1, block);
c0e59e1a 3825 error = xfs_btree_kill_root(cur, bp, level, pp);
91cca5df
CH		 3826 if (error)
3827 goto error0;
3828 } else if (level > 0) {
3829 error = xfs_btree_dec_cursor(cur, level, stat);
3830 if (error)
3831 goto error0;
3832 }
3833 *stat = 1;
3834 return 0;
3835 }
3836
3837 /*
3838 * If we deleted the leftmost entry in the block, update the
3839 * key values above us in the tree.
3840 */
70b22659 3841 if (xfs_btree_needs_key_update(cur, ptr)) {
973b8319 3842 error = xfs_btree_update_keys(cur, level);
91cca5df
CH		 3843 if (error)
3844 goto error0;
3845 }
3846
3847 /*
3848 * If the number of records remaining in the block is at least
3849 * the minimum, we're done.
3850 */
3851 if (numrecs >= cur->bc_ops->get_minrecs(cur, level)) {
3852 error = xfs_btree_dec_cursor(cur, level, stat);
3853 if (error)
3854 goto error0;
3855 return 0;
3856 }
3857
3858 /*
3859 * Otherwise, we have to move some records around to keep the
3860 * tree balanced. Look at the left and right sibling blocks to
3861 * see if we can re-balance by moving only one record.
3862 */
3863 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
3864 xfs_btree_get_sibling(cur, block, &lptr, XFS_BB_LEFTSIB);
3865
3866 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3867 /*
3868 * One child of root, need to get a chance to copy its contents
3869 * into the root and delete it. Can't go up to next level,
3870 * there's nothing to delete there.
3871 */
3872 if (xfs_btree_ptr_is_null(cur, &rptr) &&
3873 xfs_btree_ptr_is_null(cur, &lptr) &&
3874 level == cur->bc_nlevels - 2) {
3875 error = xfs_btree_kill_iroot(cur);
3876 if (!error)
3877 error = xfs_btree_dec_cursor(cur, level, stat);
3878 if (error)
3879 goto error0;
3880 return 0;
3881 }
3882 }
3883
3884 ASSERT(!xfs_btree_ptr_is_null(cur, &rptr) ||
3885 !xfs_btree_ptr_is_null(cur, &lptr));
3886
3887 /*
3888 * Duplicate the cursor so our btree manipulations here won't
3889 * disrupt the next level up.
3890 */
3891 error = xfs_btree_dup_cursor(cur, &tcur);
3892 if (error)
3893 goto error0;
3894
3895 /*
3896 * If there's a right sibling, see if it's ok to shift an entry
3897 * out of it.
3898 */
3899 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
3900 /*
3901 * Move the temp cursor to the last entry in the next block.
3902 * Actually any entry but the first would suffice.
3903 */
3904 i = xfs_btree_lastrec(tcur, level);
c29aad41 3905 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
91cca5df
CH		 3906
3907 error = xfs_btree_increment(tcur, level, &i);
3908 if (error)
3909 goto error0;
c29aad41 3910 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
91cca5df
CH		 3911
3912 i = xfs_btree_lastrec(tcur, level);
c29aad41 3913 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
91cca5df
CH		 3914
3915 /* Grab a pointer to the block. */
3916 right = xfs_btree_get_block(tcur, level, &rbp);
3917#ifdef DEBUG
3918 error = xfs_btree_check_block(tcur, right, level, rbp);
3919 if (error)
3920 goto error0;
3921#endif
3922 /* Grab the current block number, for future use. */
3923 xfs_btree_get_sibling(tcur, right, &cptr, XFS_BB_LEFTSIB);
3924
3925 /*
3926 * If right block is full enough so that removing one entry
3927 * won't make it too empty, and left-shifting an entry out
3928 * of right to us works, we're done.
3929 */
3930 if (xfs_btree_get_numrecs(right) - 1 >=
3931 cur->bc_ops->get_minrecs(tcur, level)) {
3932 error = xfs_btree_lshift(tcur, level, &i);
3933 if (error)
3934 goto error0;
3935 if (i) {
3936 ASSERT(xfs_btree_get_numrecs(block) >=
3937 cur->bc_ops->get_minrecs(tcur, level));
3938
3939 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3940 tcur = NULL;
3941
3942 error = xfs_btree_dec_cursor(cur, level, stat);
3943 if (error)
3944 goto error0;
3945 return 0;
3946 }
3947 }
3948
3949 /*
3950 * Otherwise, grab the number of records in right for
3951 * future reference, and fix up the temp cursor to point
3952 * to our block again (last record).
3953 */
3954 rrecs = xfs_btree_get_numrecs(right);
3955 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3956 i = xfs_btree_firstrec(tcur, level);
c29aad41 3957 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
91cca5df
CH		 3958
3959 error = xfs_btree_decrement(tcur, level, &i);
3960 if (error)
3961 goto error0;
c29aad41 3962 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
91cca5df
CH		 3963 }
3964 }
3965
3966 /*
3967 * If there's a left sibling, see if it's ok to shift an entry
3968 * out of it.
3969 */
3970 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3971 /*
3972 * Move the temp cursor to the first entry in the
3973 * previous block.
3974 */
3975 i = xfs_btree_firstrec(tcur, level);
c29aad41 3976 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
91cca5df
CH		 3977
3978 error = xfs_btree_decrement(tcur, level, &i);
3979 if (error)
3980 goto error0;
3981 i = xfs_btree_firstrec(tcur, level);
c29aad41 3982 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
91cca5df
CH		 3983
3984 /* Grab a pointer to the block. */
3985 left = xfs_btree_get_block(tcur, level, &lbp);
3986#ifdef DEBUG
3987 error = xfs_btree_check_block(cur, left, level, lbp);
3988 if (error)
3989 goto error0;
3990#endif
3991 /* Grab the current block number, for future use. */
3992 xfs_btree_get_sibling(tcur, left, &cptr, XFS_BB_RIGHTSIB);
3993
3994 /*
3995 * If left block is full enough so that removing one entry
3996 * won't make it too empty, and right-shifting an entry out
3997 * of left to us works, we're done.
3998 */
3999 if (xfs_btree_get_numrecs(left) - 1 >=
4000 cur->bc_ops->get_minrecs(tcur, level)) {
4001 error = xfs_btree_rshift(tcur, level, &i);
4002 if (error)
4003 goto error0;
4004 if (i) {
4005 ASSERT(xfs_btree_get_numrecs(block) >=
4006 cur->bc_ops->get_minrecs(tcur, level));
4007 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
4008 tcur = NULL;
4009 if (level == 0)
4010 cur->bc_ptrs[0]++;
4011 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
4012 *stat = 1;
4013 return 0;
4014 }
4015 }
4016
4017 /*
4018 * Otherwise, grab the number of records in right for
4019 * future reference.
4020 */
4021 lrecs = xfs_btree_get_numrecs(left);
4022 }
4023
4024 /* Delete the temp cursor, we're done with it. */
4025 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
4026 tcur = NULL;
4027
4028 /* If here, we need to do a join to keep the tree balanced. */
4029 ASSERT(!xfs_btree_ptr_is_null(cur, &cptr));
4030
4031 if (!xfs_btree_ptr_is_null(cur, &lptr) &&
4032 lrecs + xfs_btree_get_numrecs(block) <=
4033 cur->bc_ops->get_maxrecs(cur, level)) {
4034 /*
4035 * Set "right" to be the starting block,
4036 * "left" to be the left neighbor.
4037 */
4038 rptr = cptr;
4039 right = block;
4040 rbp = bp;
0d7409b1 4041 error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
91cca5df
CH		 4042 if (error)
4043 goto error0;
4044
4045 /*
4046 * If that won't work, see if we can join with the right neighbor block.
4047 */
4048 } else if (!xfs_btree_ptr_is_null(cur, &rptr) &&
4049 rrecs + xfs_btree_get_numrecs(block) <=
4050 cur->bc_ops->get_maxrecs(cur, level)) {
4051 /*
4052 * Set "left" to be the starting block,
4053 * "right" to be the right neighbor.
4054 */
4055 lptr = cptr;
4056 left = block;
4057 lbp = bp;
0d7409b1 4058 error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
91cca5df
CH		 4059 if (error)
4060 goto error0;
4061
4062 /*
4063 * Otherwise, we can't fix the imbalance.
4064 * Just return. This is probably a logic error, but it's not fatal.
4065 */
4066 } else {
4067 error = xfs_btree_dec_cursor(cur, level, stat);
4068 if (error)
4069 goto error0;
4070 return 0;
4071 }
4072
4073 rrecs = xfs_btree_get_numrecs(right);
4074 lrecs = xfs_btree_get_numrecs(left);
4075
4076 /*
4077 * We're now going to join "left" and "right" by moving all the stuff
4078 * in "right" to "left" and deleting "right".
4079 */
4080 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
4081 if (level > 0) {
4082 /* It's a non-leaf. Move keys and pointers. */
4083 union xfs_btree_key *lkp; /* left btree key */
4084 union xfs_btree_ptr *lpp; /* left address pointer */
4085 union xfs_btree_key *rkp; /* right btree key */
4086 union xfs_btree_ptr *rpp; /* right address pointer */
4087
4088 lkp = xfs_btree_key_addr(cur, lrecs + 1, left);
4089 lpp = xfs_btree_ptr_addr(cur, lrecs + 1, left);
4090 rkp = xfs_btree_key_addr(cur, 1, right);
4091 rpp = xfs_btree_ptr_addr(cur, 1, right);
4092#ifdef DEBUG
4093 for (i = 1; i < rrecs; i++) {
4094 error = xfs_btree_check_ptr(cur, rpp, i, level);
4095 if (error)
4096 goto error0;
4097 }
4098#endif
4099 xfs_btree_copy_keys(cur, lkp, rkp, rrecs);
4100 xfs_btree_copy_ptrs(cur, lpp, rpp, rrecs);
4101
4102 xfs_btree_log_keys(cur, lbp, lrecs + 1, lrecs + rrecs);
4103 xfs_btree_log_ptrs(cur, lbp, lrecs + 1, lrecs + rrecs);
4104 } else {
4105 /* It's a leaf. Move records. */
4106 union xfs_btree_rec *lrp; /* left record pointer */
4107 union xfs_btree_rec *rrp; /* right record pointer */
4108
4109 lrp = xfs_btree_rec_addr(cur, lrecs + 1, left);
4110 rrp = xfs_btree_rec_addr(cur, 1, right);
4111
4112 xfs_btree_copy_recs(cur, lrp, rrp, rrecs);
4113 xfs_btree_log_recs(cur, lbp, lrecs + 1, lrecs + rrecs);
4114 }
4115
4116 XFS_BTREE_STATS_INC(cur, join);
4117
4118 /*
9da096fd 4119 * Fix up the number of records and right block pointer in the
91cca5df
CH		 4120 * surviving block, and log it.
4121 */
4122 xfs_btree_set_numrecs(left, lrecs + rrecs);
4123 xfs_btree_get_sibling(cur, right, &cptr, XFS_BB_RIGHTSIB),
4124 xfs_btree_set_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
4125 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
4126
4127 /* If there is a right sibling, point it to the remaining block. */
4128 xfs_btree_get_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
4129 if (!xfs_btree_ptr_is_null(cur, &cptr)) {
0d7409b1 4130 error = xfs_btree_read_buf_block(cur, &cptr, 0, &rrblock, &rrbp);
91cca5df
CH		 4131 if (error)
4132 goto error0;
4133 xfs_btree_set_sibling(cur, rrblock, &lptr, XFS_BB_LEFTSIB);
4134 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
4135 }
4136
4137 /* Free the deleted block. */
c46ee8ad 4138 error = xfs_btree_free_block(cur, rbp);
91cca5df
CH		 4139 if (error)
4140 goto error0;
91cca5df
CH		 4141
4142 /*
4143 * If we joined with the left neighbor, set the buffer in the
4144 * cursor to the left block, and fix up the index.
4145 */
4146 if (bp != lbp) {
4147 cur->bc_bufs[level] = lbp;
4148 cur->bc_ptrs[level] += lrecs;
4149 cur->bc_ra[level] = 0;
4150 }
4151 /*
4152 * If we joined with the right neighbor and there's a level above
4153 * us, increment the cursor at that level.
4154 */
4155 else if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) ||
4156 (level + 1 < cur->bc_nlevels)) {
4157 error = xfs_btree_increment(cur, level + 1, &i);
4158 if (error)
4159 goto error0;
4160 }
4161
4162 /*
4163 * Readjust the ptr at this level if it's not a leaf, since it's
4164 * still pointing at the deletion point, which makes the cursor
4165 * inconsistent. If this makes the ptr 0, the caller fixes it up.
4166 * We can't use decrement because it would change the next level up.
4167 */
4168 if (level > 0)
4169 cur->bc_ptrs[level]--;
4170
2c813ad6
DW		 4171 /*
4172 * We combined blocks, so we have to update the parent keys if the
4173 * btree supports overlapped intervals. However, bc_ptrs[level + 1]
4174 * points to the old block so that the caller knows which record to
4175 * delete. Therefore, the caller must be savvy enough to call updkeys
4176 * for us if we return stat == 2. The other exit points from this
4177 * function don't require deletions further up the tree, so they can
4178 * call updkeys directly.
4179 */
4180
91cca5df
CH		 4181 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
4182 /* Return value means the next level up has something to do. */
4183 *stat = 2;
4184 return 0;
4185
4186error0:
4187 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
4188 if (tcur)
4189 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
4190 return error;
4191}
4192
4193/*
4194 * Delete the record pointed to by cur.
4195 * The cursor refers to the place where the record was (could be inserted)
4196 * when the operation returns.
4197 */
4198int /* error */
4199xfs_btree_delete(
4200 struct xfs_btree_cur *cur,
4201 int *stat) /* success/failure */
4202{
4203 int error; /* error return value */
4204 int level;
4205 int i;
2c813ad6 4206 bool joined = false;
91cca5df
CH		 4207
4208 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
4209
4210 /*
4211 * Go up the tree, starting at leaf level.
4212 *
4213 * If 2 is returned then a join was done; go to the next level.
4214 * Otherwise we are done.
4215 */
4216 for (level = 0, i = 2; i == 2; level++) {
4217 error = xfs_btree_delrec(cur, level, &i);
4218 if (error)
4219 goto error0;
2c813ad6
DW		 4220 if (i == 2)
4221 joined = true;
4222 }
4223
4224 /*
4225 * If we combined blocks as part of deleting the record, delrec won't
4226 * have updated the parent high keys so we have to do that here.
4227 */
4228 if (joined && (cur->bc_flags & XFS_BTREE_OVERLAPPING)) {
4229 error = xfs_btree_updkeys_force(cur, 0);
4230 if (error)
4231 goto error0;
91cca5df
CH		 4232 }
4233
4234 if (i == 0) {
4235 for (level = 1; level < cur->bc_nlevels; level++) {
4236 if (cur->bc_ptrs[level] == 0) {
4237 error = xfs_btree_decrement(cur, level, &i);
4238 if (error)
4239 goto error0;
4240 break;
4241 }
4242 }
4243 }
4244
4245 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
4246 *stat = i;
4247 return 0;
4248error0:
4249 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
4250 return error;
4251}
8cc938fe
CH		 4252
4253/*
4254 * Get the data from the pointed-to record.
4255 */
4256int /* error */
4257xfs_btree_get_rec(
4258 struct xfs_btree_cur *cur, /* btree cursor */
4259 union xfs_btree_rec **recp, /* output: btree record */
4260 int *stat) /* output: success/failure */
4261{
4262 struct xfs_btree_block *block; /* btree block */
4263 struct xfs_buf *bp; /* buffer pointer */
4264 int ptr; /* record number */
4265#ifdef DEBUG
4266 int error; /* error return value */
4267#endif
4268
4269 ptr = cur->bc_ptrs[0];
4270 block = xfs_btree_get_block(cur, 0, &bp);
4271
4272#ifdef DEBUG
4273 error = xfs_btree_check_block(cur, block, 0, bp);
4274 if (error)
4275 return error;
4276#endif
4277
4278 /*
4279 * Off the right end or left end, return failure.
4280 */
4281 if (ptr > xfs_btree_get_numrecs(block) || ptr <= 0) {
4282 *stat = 0;
4283 return 0;
4284 }
4285
4286 /*
4287 * Point to the record and extract its data.
4288 */
4289 *recp = xfs_btree_rec_addr(cur, ptr, block);
4290 *stat = 1;
4291 return 0;
4292}
21b5c978 4293
28a89567
DW		 4294/* Visit a block in a btree. */
4295STATIC int
4296xfs_btree_visit_block(
4297 struct xfs_btree_cur *cur,
4298 int level,
4299 xfs_btree_visit_blocks_fn fn,
4300 void *data)
4301{
4302 struct xfs_btree_block *block;
4303 struct xfs_buf *bp;
4304 union xfs_btree_ptr rptr;
4305 int error;
4306
4307 /* do right sibling readahead */
4308 xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
4309 block = xfs_btree_get_block(cur, level, &bp);
4310
4311 /* process the block */
4312 error = fn(cur, level, data);
4313 if (error)
4314 return error;
4315
4316 /* now read rh sibling block for next iteration */
4317 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
4318 if (xfs_btree_ptr_is_null(cur, &rptr))
4319 return -ENOENT;
4320
4321 return xfs_btree_lookup_get_block(cur, level, &rptr, &block);
4322}
4323
4324
4325/* Visit every block in a btree. */
4326int
4327xfs_btree_visit_blocks(
4328 struct xfs_btree_cur *cur,
4329 xfs_btree_visit_blocks_fn fn,
4330 void *data)
4331{
4332 union xfs_btree_ptr lptr;
4333 int level;
4334 struct xfs_btree_block *block = NULL;
4335 int error = 0;
4336
4337 cur->bc_ops->init_ptr_from_cur(cur, &lptr);
4338
4339 /* for each level */
4340 for (level = cur->bc_nlevels - 1; level >= 0; level--) {
4341 /* grab the left hand block */
4342 error = xfs_btree_lookup_get_block(cur, level, &lptr, &block);
4343 if (error)
4344 return error;
4345
4346 /* readahead the left most block for the next level down */
4347 if (level > 0) {
4348 union xfs_btree_ptr *ptr;
4349
4350 ptr = xfs_btree_ptr_addr(cur, 1, block);
4351 xfs_btree_readahead_ptr(cur, ptr, 1);
4352
4353 /* save for the next iteration of the loop */
4354 lptr = *ptr;
4355 }
4356
4357 /* for each buffer in the level */
4358 do {
4359 error = xfs_btree_visit_block(cur, level, fn, data);
4360 } while (!error);
4361
4362 if (error != -ENOENT)
4363 return error;
4364 }
4365
4366 return 0;
4367}
4368
21b5c978
DC		 4369/*
4370 * Change the owner of a btree.
4371 *
4372 * The mechanism we use here is ordered buffer logging. Because we don't know
4373 * how many buffers were are going to need to modify, we don't really want to
4374 * have to make transaction reservations for the worst case of every buffer in a
4375 * full size btree as that may be more space that we can fit in the log....
4376 *
4377 * We do the btree walk in the most optimal manner possible - we have sibling
4378 * pointers so we can just walk all the blocks on each level from left to right
4379 * in a single pass, and then move to the next level and do the same. We can
4380 * also do readahead on the sibling pointers to get IO moving more quickly,
4381 * though for slow disks this is unlikely to make much difference to performance
4382 * as the amount of CPU work we have to do before moving to the next block is
4383 * relatively small.
4384 *
4385 * For each btree block that we load, modify the owner appropriately, set the
4386 * buffer as an ordered buffer and log it appropriately. We need to ensure that
4387 * we mark the region we change dirty so that if the buffer is relogged in
4388 * a subsequent transaction the changes we make here as an ordered buffer are
638f4416
DC		 4389 * correctly relogged in that transaction. If we are in recovery context, then
4390 * just queue the modified buffer as delayed write buffer so the transaction
4391 * recovery completion writes the changes to disk.
21b5c978 4392 */
28a89567
DW		 4393struct xfs_btree_block_change_owner_info {
4394 __uint64_t new_owner;
4395 struct list_head *buffer_list;
4396};
4397
21b5c978
DC		 4398static int
4399xfs_btree_block_change_owner(
4400 struct xfs_btree_cur *cur,
4401 int level,
28a89567 4402 void *data)
21b5c978 4403{
28a89567 4404 struct xfs_btree_block_change_owner_info *bbcoi = data;
21b5c978
DC		 4405 struct xfs_btree_block *block;
4406 struct xfs_buf *bp;
21b5c978
DC		 4407
4408 /* modify the owner */
4409 block = xfs_btree_get_block(cur, level, &bp);
4410 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
28a89567 4411 block->bb_u.l.bb_owner = cpu_to_be64(bbcoi->new_owner);
21b5c978 4412 else
28a89567 4413 block->bb_u.s.bb_owner = cpu_to_be32(bbcoi->new_owner);
21b5c978
DC		 4414
4415 /*
638f4416
DC		 4416 * If the block is a root block hosted in an inode, we might not have a
4417 * buffer pointer here and we shouldn't attempt to log the change as the
4418 * information is already held in the inode and discarded when the root
4419 * block is formatted into the on-disk inode fork. We still change it,
4420 * though, so everything is consistent in memory.
21b5c978
DC		 4421 */
4422 if (bp) {
638f4416
DC		 4423 if (cur->bc_tp) {
4424 xfs_trans_ordered_buf(cur->bc_tp, bp);
4425 xfs_btree_log_block(cur, bp, XFS_BB_OWNER);
4426 } else {
28a89567 4427 xfs_buf_delwri_queue(bp, bbcoi->buffer_list);
638f4416 4428 }
21b5c978
DC		 4429 } else {
4430 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
4431 ASSERT(level == cur->bc_nlevels - 1);
4432 }
4433
28a89567 4434 return 0;
21b5c978
DC		 4435}
4436
4437int
4438xfs_btree_change_owner(
4439 struct xfs_btree_cur *cur,
638f4416
DC		 4440 __uint64_t new_owner,
4441 struct list_head *buffer_list)
21b5c978 4442{
28a89567 4443 struct xfs_btree_block_change_owner_info bbcoi;
21b5c978 4444
28a89567
DW		 4445 bbcoi.new_owner = new_owner;
4446 bbcoi.buffer_list = buffer_list;
21b5c978 4447
28a89567
DW		 4448 return xfs_btree_visit_blocks(cur, xfs_btree_block_change_owner,
4449 &bbcoi);
21b5c978 4450}
c5ab131b
DW		 4451
4452/**
4453 * xfs_btree_sblock_v5hdr_verify() -- verify the v5 fields of a short-format
4454 * btree block
4455 *
4456 * @bp: buffer containing the btree block
4457 * @max_recs: pointer to the m_*_mxr max records field in the xfs mount
4458 * @pag_max_level: pointer to the per-ag max level field
4459 */
4460bool
4461xfs_btree_sblock_v5hdr_verify(
4462 struct xfs_buf *bp)
4463{
4464 struct xfs_mount *mp = bp->b_target->bt_mount;
4465 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
4466 struct xfs_perag *pag = bp->b_pag;
4467
4468 if (!xfs_sb_version_hascrc(&mp->m_sb))
4469 return false;
4470 if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid))
4471 return false;
4472 if (block->bb_u.s.bb_blkno != cpu_to_be64(bp->b_bn))
4473 return false;
4474 if (pag && be32_to_cpu(block->bb_u.s.bb_owner) != pag->pag_agno)
4475 return false;
4476 return true;
4477}
4478
4479/**
4480 * xfs_btree_sblock_verify() -- verify a short-format btree block
4481 *
4482 * @bp: buffer containing the btree block
4483 * @max_recs: maximum records allowed in this btree node
4484 */
4485bool
4486xfs_btree_sblock_verify(
4487 struct xfs_buf *bp,
4488 unsigned int max_recs)
4489{
4490 struct xfs_mount *mp = bp->b_target->bt_mount;
4491 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
4492
4493 /* numrecs verification */
4494 if (be16_to_cpu(block->bb_numrecs) > max_recs)
4495 return false;
4496
4497 /* sibling pointer verification */
4498 if (!block->bb_u.s.bb_leftsib ||
4499 (be32_to_cpu(block->bb_u.s.bb_leftsib) >= mp->m_sb.sb_agblocks &&
4500 block->bb_u.s.bb_leftsib != cpu_to_be32(NULLAGBLOCK)))
4501 return false;
4502 if (!block->bb_u.s.bb_rightsib ||
4503 (be32_to_cpu(block->bb_u.s.bb_rightsib) >= mp->m_sb.sb_agblocks &&
4504 block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK)))
4505 return false;
4506
4507 return true;
4508}
19b54ee6
DW		 4509
4510/*
4511 * Calculate the number of btree levels needed to store a given number of
4512 * records in a short-format btree.
4513 */
4514uint
4515xfs_btree_compute_maxlevels(
4516 struct xfs_mount *mp,
4517 uint *limits,
4518 unsigned long len)
4519{
4520 uint level;
4521 unsigned long maxblocks;
4522
4523 maxblocks = (len + limits[0] - 1) / limits[0];
4524 for (level = 1; maxblocks > 1; level++)
4525 maxblocks = (maxblocks + limits[1] - 1) / limits[1];
4526 return level;
4527}
105f7d83
DW		 4528
4529/*
4530 * Query a regular btree for all records overlapping a given interval.
4531 * Start with a LE lookup of the key of low_rec and return all records
4532 * until we find a record with a key greater than the key of high_rec.
4533 */
4534STATIC int
4535xfs_btree_simple_query_range(
4536 struct xfs_btree_cur *cur,
4537 union xfs_btree_key *low_key,
4538 union xfs_btree_key *high_key,
4539 xfs_btree_query_range_fn fn,
4540 void *priv)
4541{
4542 union xfs_btree_rec *recp;
4543 union xfs_btree_key rec_key;
4544 __int64_t diff;
4545 int stat;
4546 bool firstrec = true;
4547 int error;
4548
4549 ASSERT(cur->bc_ops->init_high_key_from_rec);
4550 ASSERT(cur->bc_ops->diff_two_keys);
4551
4552 /*
4553 * Find the leftmost record. The btree cursor must be set
4554 * to the low record used to generate low_key.
4555 */
4556 stat = 0;
4557 error = xfs_btree_lookup(cur, XFS_LOOKUP_LE, &stat);
4558 if (error)
4559 goto out;
4560
5b5c2dbd
DW		 4561 /* Nothing? See if there's anything to the right. */
4562 if (!stat) {
4563 error = xfs_btree_increment(cur, 0, &stat);
4564 if (error)
4565 goto out;
4566 }
4567
105f7d83
DW		 4568 while (stat) {
4569 /* Find the record. */
4570 error = xfs_btree_get_rec(cur, &recp, &stat);
4571 if (error || !stat)
4572 break;
105f7d83
DW		 4573
4574 /* Skip if high_key(rec) < low_key. */
4575 if (firstrec) {
72227899 4576 cur->bc_ops->init_high_key_from_rec(&rec_key, recp);
105f7d83
DW		 4577 firstrec = false;
4578 diff = cur->bc_ops->diff_two_keys(cur, low_key,
4579 &rec_key);
4580 if (diff > 0)
4581 goto advloop;
4582 }
4583
4584 /* Stop if high_key < low_key(rec). */
72227899 4585 cur->bc_ops->init_key_from_rec(&rec_key, recp);
105f7d83
DW		 4586 diff = cur->bc_ops->diff_two_keys(cur, &rec_key, high_key);
4587 if (diff > 0)
4588 break;
4589
4590 /* Callback */
4591 error = fn(cur, recp, priv);
4592 if (error < 0 || error == XFS_BTREE_QUERY_RANGE_ABORT)
4593 break;
4594
4595advloop:
4596 /* Move on to the next record. */
4597 error = xfs_btree_increment(cur, 0, &stat);
4598 if (error)
4599 break;
4600 }
4601
4602out:
4603 return error;
4604}
4605
4606/*
4607 * Query an overlapped interval btree for all records overlapping a given
4608 * interval. This function roughly follows the algorithm given in
4609 * "Interval Trees" of _Introduction to Algorithms_, which is section
4610 * 14.3 in the 2nd and 3rd editions.
4611 *
4612 * First, generate keys for the low and high records passed in.
4613 *
4614 * For any leaf node, generate the high and low keys for the record.
4615 * If the record keys overlap with the query low/high keys, pass the
4616 * record to the function iterator.
4617 *
4618 * For any internal node, compare the low and high keys of each
4619 * pointer against the query low/high keys. If there's an overlap,
4620 * follow the pointer.
4621 *
4622 * As an optimization, we stop scanning a block when we find a low key
4623 * that is greater than the query's high key.
4624 */
4625STATIC int
4626xfs_btree_overlapped_query_range(
4627 struct xfs_btree_cur *cur,
4628 union xfs_btree_key *low_key,
4629 union xfs_btree_key *high_key,
4630 xfs_btree_query_range_fn fn,
4631 void *priv)
4632{
4633 union xfs_btree_ptr ptr;
4634 union xfs_btree_ptr *pp;
4635 union xfs_btree_key rec_key;
4636 union xfs_btree_key rec_hkey;
4637 union xfs_btree_key *lkp;
4638 union xfs_btree_key *hkp;
4639 union xfs_btree_rec *recp;
4640 struct xfs_btree_block *block;
4641 __int64_t ldiff;
4642 __int64_t hdiff;
4643 int level;
4644 struct xfs_buf *bp;
4645 int i;
4646 int error;
4647
4648 /* Load the root of the btree. */
4649 level = cur->bc_nlevels - 1;
4650 cur->bc_ops->init_ptr_from_cur(cur, &ptr);
4651 error = xfs_btree_lookup_get_block(cur, level, &ptr, &block);
4652 if (error)
4653 return error;
4654 xfs_btree_get_block(cur, level, &bp);
4655 trace_xfs_btree_overlapped_query_range(cur, level, bp);
4656#ifdef DEBUG
4657 error = xfs_btree_check_block(cur, block, level, bp);
4658 if (error)
4659 goto out;
4660#endif
4661 cur->bc_ptrs[level] = 1;
4662
4663 while (level < cur->bc_nlevels) {
4664 block = xfs_btree_get_block(cur, level, &bp);
4665
4666 /* End of node, pop back towards the root. */
4667 if (cur->bc_ptrs[level] > be16_to_cpu(block->bb_numrecs)) {
4668pop_up:
4669 if (level < cur->bc_nlevels - 1)
4670 cur->bc_ptrs[level + 1]++;
4671 level++;
4672 continue;
4673 }
4674
4675 if (level == 0) {
4676 /* Handle a leaf node. */
4677 recp = xfs_btree_rec_addr(cur, cur->bc_ptrs[0], block);
4678
4679 cur->bc_ops->init_high_key_from_rec(&rec_hkey, recp);
4680 ldiff = cur->bc_ops->diff_two_keys(cur, &rec_hkey,
4681 low_key);
4682
4683 cur->bc_ops->init_key_from_rec(&rec_key, recp);
4684 hdiff = cur->bc_ops->diff_two_keys(cur, high_key,
4685 &rec_key);
4686
4687 /*
4688 * If (record's high key >= query's low key) and
4689 * (query's high key >= record's low key), then
4690 * this record overlaps the query range; callback.
4691 */
4692 if (ldiff >= 0 && hdiff >= 0) {
4693 error = fn(cur, recp, priv);
4694 if (error < 0 ||
4695 error == XFS_BTREE_QUERY_RANGE_ABORT)
4696 break;
4697 } else if (hdiff < 0) {
4698 /* Record is larger than high key; pop. */
4699 goto pop_up;
4700 }
4701 cur->bc_ptrs[level]++;
4702 continue;
4703 }
4704
4705 /* Handle an internal node. */
4706 lkp = xfs_btree_key_addr(cur, cur->bc_ptrs[level], block);
4707 hkp = xfs_btree_high_key_addr(cur, cur->bc_ptrs[level], block);
4708 pp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[level], block);
4709
4710 ldiff = cur->bc_ops->diff_two_keys(cur, hkp, low_key);
4711 hdiff = cur->bc_ops->diff_two_keys(cur, high_key, lkp);
4712
4713 /*
4714 * If (pointer's high key >= query's low key) and
4715 * (query's high key >= pointer's low key), then
4716 * this record overlaps the query range; follow pointer.
4717 */
4718 if (ldiff >= 0 && hdiff >= 0) {
4719 level--;
4720 error = xfs_btree_lookup_get_block(cur, level, pp,
4721 &block);
4722 if (error)
4723 goto out;
4724 xfs_btree_get_block(cur, level, &bp);
4725 trace_xfs_btree_overlapped_query_range(cur, level, bp);
4726#ifdef DEBUG
4727 error = xfs_btree_check_block(cur, block, level, bp);
4728 if (error)
4729 goto out;
4730#endif
4731 cur->bc_ptrs[level] = 1;
4732 continue;
4733 } else if (hdiff < 0) {
4734 /* The low key is larger than the upper range; pop. */
4735 goto pop_up;
4736 }
4737 cur->bc_ptrs[level]++;
4738 }
4739
4740out:
4741 /*
4742 * If we don't end this function with the cursor pointing at a record
4743 * block, a subsequent non-error cursor deletion will not release
4744 * node-level buffers, causing a buffer leak. This is quite possible
4745 * with a zero-results range query, so release the buffers if we
4746 * failed to return any results.
4747 */
4748 if (cur->bc_bufs[0] == NULL) {
4749 for (i = 0; i < cur->bc_nlevels; i++) {
4750 if (cur->bc_bufs[i]) {
4751 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[i]);
4752 cur->bc_bufs[i] = NULL;
4753 cur->bc_ptrs[i] = 0;
4754 cur->bc_ra[i] = 0;
4755 }
4756 }
4757 }
4758
4759 return error;
4760}
4761
4762/*
4763 * Query a btree for all records overlapping a given interval of keys. The
4764 * supplied function will be called with each record found; return one of the
4765 * XFS_BTREE_QUERY_RANGE_{CONTINUE,ABORT} values or the usual negative error
4766 * code. This function returns XFS_BTREE_QUERY_RANGE_ABORT, zero, or a
4767 * negative error code.
4768 */
4769int
4770xfs_btree_query_range(
4771 struct xfs_btree_cur *cur,
4772 union xfs_btree_irec *low_rec,
4773 union xfs_btree_irec *high_rec,
4774 xfs_btree_query_range_fn fn,
4775 void *priv)
4776{
4777 union xfs_btree_rec rec;
4778 union xfs_btree_key low_key;
4779 union xfs_btree_key high_key;
4780
4781 /* Find the keys of both ends of the interval. */
4782 cur->bc_rec = *high_rec;
4783 cur->bc_ops->init_rec_from_cur(cur, &rec);
4784 cur->bc_ops->init_key_from_rec(&high_key, &rec);
4785
4786 cur->bc_rec = *low_rec;
4787 cur->bc_ops->init_rec_from_cur(cur, &rec);
4788 cur->bc_ops->init_key_from_rec(&low_key, &rec);
4789
4790 /* Enforce low key < high key. */
4791 if (cur->bc_ops->diff_two_keys(cur, &low_key, &high_key) > 0)
4792 return -EINVAL;
4793
4794 if (!(cur->bc_flags & XFS_BTREE_OVERLAPPING))
4795 return xfs_btree_simple_query_range(cur, &low_key,
4796 &high_key, fn, priv);
4797 return xfs_btree_overlapped_query_range(cur, &low_key, &high_key,
4798 fn, priv);
4799}
Linux kernel - Deliverables
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