mm: fix exec activate_mm vs TLB shootdown and lazy tlb switching race
[linux/fpc-iii.git] / fs / xfs / libxfs / xfs_btree.c
blob5bfb88261c7e9542a0ba2fca0463c264a36be629
1 /*
2 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 #include "xfs.h"
19 #include "xfs_fs.h"
20 #include "xfs_shared.h"
21 #include "xfs_format.h"
22 #include "xfs_log_format.h"
23 #include "xfs_trans_resv.h"
24 #include "xfs_bit.h"
25 #include "xfs_mount.h"
26 #include "xfs_defer.h"
27 #include "xfs_inode.h"
28 #include "xfs_trans.h"
29 #include "xfs_inode_item.h"
30 #include "xfs_buf_item.h"
31 #include "xfs_btree.h"
32 #include "xfs_error.h"
33 #include "xfs_trace.h"
34 #include "xfs_cksum.h"
35 #include "xfs_alloc.h"
36 #include "xfs_log.h"
39 * Cursor allocation zone.
41 kmem_zone_t *xfs_btree_cur_zone;
44 * Btree magic numbers.
46 static const uint32_t xfs_magics[2][XFS_BTNUM_MAX] = {
47 { XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, 0, XFS_BMAP_MAGIC, XFS_IBT_MAGIC,
48 XFS_FIBT_MAGIC, 0 },
49 { XFS_ABTB_CRC_MAGIC, XFS_ABTC_CRC_MAGIC, XFS_RMAP_CRC_MAGIC,
50 XFS_BMAP_CRC_MAGIC, XFS_IBT_CRC_MAGIC, XFS_FIBT_CRC_MAGIC,
51 XFS_REFC_CRC_MAGIC }
54 uint32_t
55 xfs_btree_magic(
56 int crc,
57 xfs_btnum_t btnum)
59 uint32_t magic = xfs_magics[crc][btnum];
61 /* Ensure we asked for crc for crc-only magics. */
62 ASSERT(magic != 0);
63 return magic;
66 STATIC int /* error (0 or EFSCORRUPTED) */
67 xfs_btree_check_lblock(
68 struct xfs_btree_cur *cur, /* btree cursor */
69 struct xfs_btree_block *block, /* btree long form block pointer */
70 int level, /* level of the btree block */
71 struct xfs_buf *bp) /* buffer for block, if any */
73 int lblock_ok = 1; /* block passes checks */
74 struct xfs_mount *mp; /* file system mount point */
75 xfs_btnum_t btnum = cur->bc_btnum;
76 int crc;
78 mp = cur->bc_mp;
79 crc = xfs_sb_version_hascrc(&mp->m_sb);
81 if (crc) {
82 lblock_ok = lblock_ok &&
83 uuid_equal(&block->bb_u.l.bb_uuid,
84 &mp->m_sb.sb_meta_uuid) &&
85 block->bb_u.l.bb_blkno == cpu_to_be64(
86 bp ? bp->b_bn : XFS_BUF_DADDR_NULL);
89 lblock_ok = lblock_ok &&
90 be32_to_cpu(block->bb_magic) == xfs_btree_magic(crc, btnum) &&
91 be16_to_cpu(block->bb_level) == level &&
92 be16_to_cpu(block->bb_numrecs) <=
93 cur->bc_ops->get_maxrecs(cur, level) &&
94 block->bb_u.l.bb_leftsib &&
95 (block->bb_u.l.bb_leftsib == cpu_to_be64(NULLFSBLOCK) ||
96 XFS_FSB_SANITY_CHECK(mp,
97 be64_to_cpu(block->bb_u.l.bb_leftsib))) &&
98 block->bb_u.l.bb_rightsib &&
99 (block->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK) ||
100 XFS_FSB_SANITY_CHECK(mp,
101 be64_to_cpu(block->bb_u.l.bb_rightsib)));
103 if (unlikely(XFS_TEST_ERROR(!lblock_ok, mp,
104 XFS_ERRTAG_BTREE_CHECK_LBLOCK))) {
105 if (bp)
106 trace_xfs_btree_corrupt(bp, _RET_IP_);
107 XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
108 return -EFSCORRUPTED;
110 return 0;
113 STATIC int /* error (0 or EFSCORRUPTED) */
114 xfs_btree_check_sblock(
115 struct xfs_btree_cur *cur, /* btree cursor */
116 struct xfs_btree_block *block, /* btree short form block pointer */
117 int level, /* level of the btree block */
118 struct xfs_buf *bp) /* buffer containing block */
120 struct xfs_mount *mp; /* file system mount point */
121 struct xfs_buf *agbp; /* buffer for ag. freespace struct */
122 struct xfs_agf *agf; /* ag. freespace structure */
123 xfs_agblock_t agflen; /* native ag. freespace length */
124 int sblock_ok = 1; /* block passes checks */
125 xfs_btnum_t btnum = cur->bc_btnum;
126 int crc;
128 mp = cur->bc_mp;
129 crc = xfs_sb_version_hascrc(&mp->m_sb);
130 agbp = cur->bc_private.a.agbp;
131 agf = XFS_BUF_TO_AGF(agbp);
132 agflen = be32_to_cpu(agf->agf_length);
134 if (crc) {
135 sblock_ok = sblock_ok &&
136 uuid_equal(&block->bb_u.s.bb_uuid,
137 &mp->m_sb.sb_meta_uuid) &&
138 block->bb_u.s.bb_blkno == cpu_to_be64(
139 bp ? bp->b_bn : XFS_BUF_DADDR_NULL);
142 sblock_ok = sblock_ok &&
143 be32_to_cpu(block->bb_magic) == xfs_btree_magic(crc, btnum) &&
144 be16_to_cpu(block->bb_level) == level &&
145 be16_to_cpu(block->bb_numrecs) <=
146 cur->bc_ops->get_maxrecs(cur, level) &&
147 (block->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK) ||
148 be32_to_cpu(block->bb_u.s.bb_leftsib) < agflen) &&
149 block->bb_u.s.bb_leftsib &&
150 (block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK) ||
151 be32_to_cpu(block->bb_u.s.bb_rightsib) < agflen) &&
152 block->bb_u.s.bb_rightsib;
154 if (unlikely(XFS_TEST_ERROR(!sblock_ok, mp,
155 XFS_ERRTAG_BTREE_CHECK_SBLOCK))) {
156 if (bp)
157 trace_xfs_btree_corrupt(bp, _RET_IP_);
158 XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
159 return -EFSCORRUPTED;
161 return 0;
165 * Debug routine: check that block header is ok.
168 xfs_btree_check_block(
169 struct xfs_btree_cur *cur, /* btree cursor */
170 struct xfs_btree_block *block, /* generic btree block pointer */
171 int level, /* level of the btree block */
172 struct xfs_buf *bp) /* buffer containing block, if any */
174 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
175 return xfs_btree_check_lblock(cur, block, level, bp);
176 else
177 return xfs_btree_check_sblock(cur, block, level, bp);
181 * Check that (long) pointer is ok.
183 int /* error (0 or EFSCORRUPTED) */
184 xfs_btree_check_lptr(
185 struct xfs_btree_cur *cur, /* btree cursor */
186 xfs_fsblock_t bno, /* btree block disk address */
187 int level) /* btree block level */
189 XFS_WANT_CORRUPTED_RETURN(cur->bc_mp,
190 level > 0 &&
191 bno != NULLFSBLOCK &&
192 XFS_FSB_SANITY_CHECK(cur->bc_mp, bno));
193 return 0;
196 #ifdef DEBUG
198 * Check that (short) pointer is ok.
200 STATIC int /* error (0 or EFSCORRUPTED) */
201 xfs_btree_check_sptr(
202 struct xfs_btree_cur *cur, /* btree cursor */
203 xfs_agblock_t bno, /* btree block disk address */
204 int level) /* btree block level */
206 xfs_agblock_t agblocks = cur->bc_mp->m_sb.sb_agblocks;
208 XFS_WANT_CORRUPTED_RETURN(cur->bc_mp,
209 level > 0 &&
210 bno != NULLAGBLOCK &&
211 bno != 0 &&
212 bno < agblocks);
213 return 0;
217 * Check that block ptr is ok.
219 STATIC int /* error (0 or EFSCORRUPTED) */
220 xfs_btree_check_ptr(
221 struct xfs_btree_cur *cur, /* btree cursor */
222 union xfs_btree_ptr *ptr, /* btree block disk address */
223 int index, /* offset from ptr to check */
224 int level) /* btree block level */
226 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
227 return xfs_btree_check_lptr(cur,
228 be64_to_cpu((&ptr->l)[index]), level);
229 } else {
230 return xfs_btree_check_sptr(cur,
231 be32_to_cpu((&ptr->s)[index]), level);
234 #endif
237 * Calculate CRC on the whole btree block and stuff it into the
238 * long-form btree header.
240 * Prior to calculting the CRC, pull the LSN out of the buffer log item and put
241 * it into the buffer so recovery knows what the last modification was that made
242 * it to disk.
244 void
245 xfs_btree_lblock_calc_crc(
246 struct xfs_buf *bp)
248 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
249 struct xfs_buf_log_item *bip = bp->b_fspriv;
251 if (!xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb))
252 return;
253 if (bip)
254 block->bb_u.l.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
255 xfs_buf_update_cksum(bp, XFS_BTREE_LBLOCK_CRC_OFF);
258 bool
259 xfs_btree_lblock_verify_crc(
260 struct xfs_buf *bp)
262 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
263 struct xfs_mount *mp = bp->b_target->bt_mount;
265 if (xfs_sb_version_hascrc(&mp->m_sb)) {
266 if (!xfs_log_check_lsn(mp, be64_to_cpu(block->bb_u.l.bb_lsn)))
267 return false;
268 return xfs_buf_verify_cksum(bp, XFS_BTREE_LBLOCK_CRC_OFF);
271 return true;
275 * Calculate CRC on the whole btree block and stuff it into the
276 * short-form btree header.
278 * Prior to calculting the CRC, pull the LSN out of the buffer log item and put
279 * it into the buffer so recovery knows what the last modification was that made
280 * it to disk.
282 void
283 xfs_btree_sblock_calc_crc(
284 struct xfs_buf *bp)
286 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
287 struct xfs_buf_log_item *bip = bp->b_fspriv;
289 if (!xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb))
290 return;
291 if (bip)
292 block->bb_u.s.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
293 xfs_buf_update_cksum(bp, XFS_BTREE_SBLOCK_CRC_OFF);
296 bool
297 xfs_btree_sblock_verify_crc(
298 struct xfs_buf *bp)
300 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
301 struct xfs_mount *mp = bp->b_target->bt_mount;
303 if (xfs_sb_version_hascrc(&mp->m_sb)) {
304 if (!xfs_log_check_lsn(mp, be64_to_cpu(block->bb_u.s.bb_lsn)))
305 return false;
306 return xfs_buf_verify_cksum(bp, XFS_BTREE_SBLOCK_CRC_OFF);
309 return true;
312 static int
313 xfs_btree_free_block(
314 struct xfs_btree_cur *cur,
315 struct xfs_buf *bp)
317 int error;
319 error = cur->bc_ops->free_block(cur, bp);
320 if (!error) {
321 xfs_trans_binval(cur->bc_tp, bp);
322 XFS_BTREE_STATS_INC(cur, free);
324 return error;
328 * Delete the btree cursor.
330 void
331 xfs_btree_del_cursor(
332 xfs_btree_cur_t *cur, /* btree cursor */
333 int error) /* del because of error */
335 int i; /* btree level */
338 * Clear the buffer pointers, and release the buffers.
339 * If we're doing this in the face of an error, we
340 * need to make sure to inspect all of the entries
341 * in the bc_bufs array for buffers to be unlocked.
342 * This is because some of the btree code works from
343 * level n down to 0, and if we get an error along
344 * the way we won't have initialized all the entries
345 * down to 0.
347 for (i = 0; i < cur->bc_nlevels; i++) {
348 if (cur->bc_bufs[i])
349 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[i]);
350 else if (!error)
351 break;
354 * Can't free a bmap cursor without having dealt with the
355 * allocated indirect blocks' accounting.
357 ASSERT(cur->bc_btnum != XFS_BTNUM_BMAP ||
358 cur->bc_private.b.allocated == 0);
360 * Free the cursor.
362 kmem_zone_free(xfs_btree_cur_zone, cur);
366 * Duplicate the btree cursor.
367 * Allocate a new one, copy the record, re-get the buffers.
369 int /* error */
370 xfs_btree_dup_cursor(
371 xfs_btree_cur_t *cur, /* input cursor */
372 xfs_btree_cur_t **ncur) /* output cursor */
374 xfs_buf_t *bp; /* btree block's buffer pointer */
375 int error; /* error return value */
376 int i; /* level number of btree block */
377 xfs_mount_t *mp; /* mount structure for filesystem */
378 xfs_btree_cur_t *new; /* new cursor value */
379 xfs_trans_t *tp; /* transaction pointer, can be NULL */
381 tp = cur->bc_tp;
382 mp = cur->bc_mp;
385 * Allocate a new cursor like the old one.
387 new = cur->bc_ops->dup_cursor(cur);
390 * Copy the record currently in the cursor.
392 new->bc_rec = cur->bc_rec;
395 * For each level current, re-get the buffer and copy the ptr value.
397 for (i = 0; i < new->bc_nlevels; i++) {
398 new->bc_ptrs[i] = cur->bc_ptrs[i];
399 new->bc_ra[i] = cur->bc_ra[i];
400 bp = cur->bc_bufs[i];
401 if (bp) {
402 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
403 XFS_BUF_ADDR(bp), mp->m_bsize,
404 0, &bp,
405 cur->bc_ops->buf_ops);
406 if (error) {
407 xfs_btree_del_cursor(new, error);
408 *ncur = NULL;
409 return error;
412 new->bc_bufs[i] = bp;
414 *ncur = new;
415 return 0;
419 * XFS btree block layout and addressing:
421 * There are two types of blocks in the btree: leaf and non-leaf blocks.
423 * The leaf record start with a header then followed by records containing
424 * the values. A non-leaf block also starts with the same header, and
425 * then first contains lookup keys followed by an equal number of pointers
426 * to the btree blocks at the previous level.
428 * +--------+-------+-------+-------+-------+-------+-------+
429 * Leaf: | header | rec 1 | rec 2 | rec 3 | rec 4 | rec 5 | rec N |
430 * +--------+-------+-------+-------+-------+-------+-------+
432 * +--------+-------+-------+-------+-------+-------+-------+
433 * Non-Leaf: | header | key 1 | key 2 | key N | ptr 1 | ptr 2 | ptr N |
434 * +--------+-------+-------+-------+-------+-------+-------+
436 * The header is called struct xfs_btree_block for reasons better left unknown
437 * and comes in different versions for short (32bit) and long (64bit) block
438 * pointers. The record and key structures are defined by the btree instances
439 * and opaque to the btree core. The block pointers are simple disk endian
440 * integers, available in a short (32bit) and long (64bit) variant.
442 * The helpers below calculate the offset of a given record, key or pointer
443 * into a btree block (xfs_btree_*_offset) or return a pointer to the given
444 * record, key or pointer (xfs_btree_*_addr). Note that all addressing
445 * inside the btree block is done using indices starting at one, not zero!
447 * If XFS_BTREE_OVERLAPPING is set, then this btree supports keys containing
448 * overlapping intervals. In such a tree, records are still sorted lowest to
449 * highest and indexed by the smallest key value that refers to the record.
450 * However, nodes are different: each pointer has two associated keys -- one
451 * indexing the lowest key available in the block(s) below (the same behavior
452 * as the key in a regular btree) and another indexing the highest key
453 * available in the block(s) below. Because records are /not/ sorted by the
454 * highest key, all leaf block updates require us to compute the highest key
455 * that matches any record in the leaf and to recursively update the high keys
456 * in the nodes going further up in the tree, if necessary. Nodes look like
457 * this:
459 * +--------+-----+-----+-----+-----+-----+-------+-------+-----+
460 * Non-Leaf: | header | lo1 | hi1 | lo2 | hi2 | ... | ptr 1 | ptr 2 | ... |
461 * +--------+-----+-----+-----+-----+-----+-------+-------+-----+
463 * To perform an interval query on an overlapped tree, perform the usual
464 * depth-first search and use the low and high keys to decide if we can skip
465 * that particular node. If a leaf node is reached, return the records that
466 * intersect the interval. Note that an interval query may return numerous
467 * entries. For a non-overlapped tree, simply search for the record associated
468 * with the lowest key and iterate forward until a non-matching record is
469 * found. Section 14.3 ("Interval Trees") of _Introduction to Algorithms_ by
470 * Cormen, Leiserson, Rivest, and Stein (2nd or 3rd ed. only) discuss this in
471 * more detail.
473 * Why do we care about overlapping intervals? Let's say you have a bunch of
474 * reverse mapping records on a reflink filesystem:
476 * 1: +- file A startblock B offset C length D -----------+
477 * 2: +- file E startblock F offset G length H --------------+
478 * 3: +- file I startblock F offset J length K --+
479 * 4: +- file L... --+
481 * Now say we want to map block (B+D) into file A at offset (C+D). Ideally,
482 * we'd simply increment the length of record 1. But how do we find the record
483 * that ends at (B+D-1) (i.e. record 1)? A LE lookup of (B+D-1) would return
484 * record 3 because the keys are ordered first by startblock. An interval
485 * query would return records 1 and 2 because they both overlap (B+D-1), and
486 * from that we can pick out record 1 as the appropriate left neighbor.
488 * In the non-overlapped case you can do a LE lookup and decrement the cursor
489 * because a record's interval must end before the next record.
493 * Return size of the btree block header for this btree instance.
495 static inline size_t xfs_btree_block_len(struct xfs_btree_cur *cur)
497 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
498 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
499 return XFS_BTREE_LBLOCK_CRC_LEN;
500 return XFS_BTREE_LBLOCK_LEN;
502 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
503 return XFS_BTREE_SBLOCK_CRC_LEN;
504 return XFS_BTREE_SBLOCK_LEN;
508 * Return size of btree block pointers for this btree instance.
510 static inline size_t xfs_btree_ptr_len(struct xfs_btree_cur *cur)
512 return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
513 sizeof(__be64) : sizeof(__be32);
517 * Calculate offset of the n-th record in a btree block.
519 STATIC size_t
520 xfs_btree_rec_offset(
521 struct xfs_btree_cur *cur,
522 int n)
524 return xfs_btree_block_len(cur) +
525 (n - 1) * cur->bc_ops->rec_len;
529 * Calculate offset of the n-th key in a btree block.
531 STATIC size_t
532 xfs_btree_key_offset(
533 struct xfs_btree_cur *cur,
534 int n)
536 return xfs_btree_block_len(cur) +
537 (n - 1) * cur->bc_ops->key_len;
541 * Calculate offset of the n-th high key in a btree block.
543 STATIC size_t
544 xfs_btree_high_key_offset(
545 struct xfs_btree_cur *cur,
546 int n)
548 return xfs_btree_block_len(cur) +
549 (n - 1) * cur->bc_ops->key_len + (cur->bc_ops->key_len / 2);
553 * Calculate offset of the n-th block pointer in a btree block.
555 STATIC size_t
556 xfs_btree_ptr_offset(
557 struct xfs_btree_cur *cur,
558 int n,
559 int level)
561 return xfs_btree_block_len(cur) +
562 cur->bc_ops->get_maxrecs(cur, level) * cur->bc_ops->key_len +
563 (n - 1) * xfs_btree_ptr_len(cur);
567 * Return a pointer to the n-th record in the btree block.
569 union xfs_btree_rec *
570 xfs_btree_rec_addr(
571 struct xfs_btree_cur *cur,
572 int n,
573 struct xfs_btree_block *block)
575 return (union xfs_btree_rec *)
576 ((char *)block + xfs_btree_rec_offset(cur, n));
580 * Return a pointer to the n-th key in the btree block.
582 union xfs_btree_key *
583 xfs_btree_key_addr(
584 struct xfs_btree_cur *cur,
585 int n,
586 struct xfs_btree_block *block)
588 return (union xfs_btree_key *)
589 ((char *)block + xfs_btree_key_offset(cur, n));
593 * Return a pointer to the n-th high key in the btree block.
595 union xfs_btree_key *
596 xfs_btree_high_key_addr(
597 struct xfs_btree_cur *cur,
598 int n,
599 struct xfs_btree_block *block)
601 return (union xfs_btree_key *)
602 ((char *)block + xfs_btree_high_key_offset(cur, n));
606 * Return a pointer to the n-th block pointer in the btree block.
608 union xfs_btree_ptr *
609 xfs_btree_ptr_addr(
610 struct xfs_btree_cur *cur,
611 int n,
612 struct xfs_btree_block *block)
614 int level = xfs_btree_get_level(block);
616 ASSERT(block->bb_level != 0);
618 return (union xfs_btree_ptr *)
619 ((char *)block + xfs_btree_ptr_offset(cur, n, level));
623 * Get the root block which is stored in the inode.
625 * For now this btree implementation assumes the btree root is always
626 * stored in the if_broot field of an inode fork.
628 STATIC struct xfs_btree_block *
629 xfs_btree_get_iroot(
630 struct xfs_btree_cur *cur)
632 struct xfs_ifork *ifp;
634 ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, cur->bc_private.b.whichfork);
635 return (struct xfs_btree_block *)ifp->if_broot;
639 * Retrieve the block pointer from the cursor at the given level.
640 * This may be an inode btree root or from a buffer.
642 struct xfs_btree_block * /* generic btree block pointer */
643 xfs_btree_get_block(
644 struct xfs_btree_cur *cur, /* btree cursor */
645 int level, /* level in btree */
646 struct xfs_buf **bpp) /* buffer containing the block */
648 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
649 (level == cur->bc_nlevels - 1)) {
650 *bpp = NULL;
651 return xfs_btree_get_iroot(cur);
654 *bpp = cur->bc_bufs[level];
655 return XFS_BUF_TO_BLOCK(*bpp);
659 * Get a buffer for the block, return it with no data read.
660 * Long-form addressing.
662 xfs_buf_t * /* buffer for fsbno */
663 xfs_btree_get_bufl(
664 xfs_mount_t *mp, /* file system mount point */
665 xfs_trans_t *tp, /* transaction pointer */
666 xfs_fsblock_t fsbno, /* file system block number */
667 uint lock) /* lock flags for get_buf */
669 xfs_daddr_t d; /* real disk block address */
671 ASSERT(fsbno != NULLFSBLOCK);
672 d = XFS_FSB_TO_DADDR(mp, fsbno);
673 return xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
677 * Get a buffer for the block, return it with no data read.
678 * Short-form addressing.
680 xfs_buf_t * /* buffer for agno/agbno */
681 xfs_btree_get_bufs(
682 xfs_mount_t *mp, /* file system mount point */
683 xfs_trans_t *tp, /* transaction pointer */
684 xfs_agnumber_t agno, /* allocation group number */
685 xfs_agblock_t agbno, /* allocation group block number */
686 uint lock) /* lock flags for get_buf */
688 xfs_daddr_t d; /* real disk block address */
690 ASSERT(agno != NULLAGNUMBER);
691 ASSERT(agbno != NULLAGBLOCK);
692 d = XFS_AGB_TO_DADDR(mp, agno, agbno);
693 return xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
697 * Check for the cursor referring to the last block at the given level.
699 int /* 1=is last block, 0=not last block */
700 xfs_btree_islastblock(
701 xfs_btree_cur_t *cur, /* btree cursor */
702 int level) /* level to check */
704 struct xfs_btree_block *block; /* generic btree block pointer */
705 xfs_buf_t *bp; /* buffer containing block */
707 block = xfs_btree_get_block(cur, level, &bp);
708 xfs_btree_check_block(cur, block, level, bp);
709 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
710 return block->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK);
711 else
712 return block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK);
716 * Change the cursor to point to the first record at the given level.
717 * Other levels are unaffected.
719 STATIC int /* success=1, failure=0 */
720 xfs_btree_firstrec(
721 xfs_btree_cur_t *cur, /* btree cursor */
722 int level) /* level to change */
724 struct xfs_btree_block *block; /* generic btree block pointer */
725 xfs_buf_t *bp; /* buffer containing block */
728 * Get the block pointer for this level.
730 block = xfs_btree_get_block(cur, level, &bp);
731 if (xfs_btree_check_block(cur, block, level, bp))
732 return 0;
734 * It's empty, there is no such record.
736 if (!block->bb_numrecs)
737 return 0;
739 * Set the ptr value to 1, that's the first record/key.
741 cur->bc_ptrs[level] = 1;
742 return 1;
746 * Change the cursor to point to the last record in the current block
747 * at the given level. Other levels are unaffected.
749 STATIC int /* success=1, failure=0 */
750 xfs_btree_lastrec(
751 xfs_btree_cur_t *cur, /* btree cursor */
752 int level) /* level to change */
754 struct xfs_btree_block *block; /* generic btree block pointer */
755 xfs_buf_t *bp; /* buffer containing block */
758 * Get the block pointer for this level.
760 block = xfs_btree_get_block(cur, level, &bp);
761 if (xfs_btree_check_block(cur, block, level, bp))
762 return 0;
764 * It's empty, there is no such record.
766 if (!block->bb_numrecs)
767 return 0;
769 * Set the ptr value to numrecs, that's the last record/key.
771 cur->bc_ptrs[level] = be16_to_cpu(block->bb_numrecs);
772 return 1;
776 * Compute first and last byte offsets for the fields given.
777 * Interprets the offsets table, which contains struct field offsets.
779 void
780 xfs_btree_offsets(
781 int64_t fields, /* bitmask of fields */
782 const short *offsets, /* table of field offsets */
783 int nbits, /* number of bits to inspect */
784 int *first, /* output: first byte offset */
785 int *last) /* output: last byte offset */
787 int i; /* current bit number */
788 int64_t imask; /* mask for current bit number */
790 ASSERT(fields != 0);
792 * Find the lowest bit, so the first byte offset.
794 for (i = 0, imask = 1LL; ; i++, imask <<= 1) {
795 if (imask & fields) {
796 *first = offsets[i];
797 break;
801 * Find the highest bit, so the last byte offset.
803 for (i = nbits - 1, imask = 1LL << i; ; i--, imask >>= 1) {
804 if (imask & fields) {
805 *last = offsets[i + 1] - 1;
806 break;
812 * Get a buffer for the block, return it read in.
813 * Long-form addressing.
816 xfs_btree_read_bufl(
817 struct xfs_mount *mp, /* file system mount point */
818 struct xfs_trans *tp, /* transaction pointer */
819 xfs_fsblock_t fsbno, /* file system block number */
820 uint lock, /* lock flags for read_buf */
821 struct xfs_buf **bpp, /* buffer for fsbno */
822 int refval, /* ref count value for buffer */
823 const struct xfs_buf_ops *ops)
825 struct xfs_buf *bp; /* return value */
826 xfs_daddr_t d; /* real disk block address */
827 int error;
829 if (!XFS_FSB_SANITY_CHECK(mp, fsbno))
830 return -EFSCORRUPTED;
831 d = XFS_FSB_TO_DADDR(mp, fsbno);
832 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
833 mp->m_bsize, lock, &bp, ops);
834 if (error)
835 return error;
836 if (bp)
837 xfs_buf_set_ref(bp, refval);
838 *bpp = bp;
839 return 0;
843 * Read-ahead the block, don't wait for it, don't return a buffer.
844 * Long-form addressing.
846 /* ARGSUSED */
847 void
848 xfs_btree_reada_bufl(
849 struct xfs_mount *mp, /* file system mount point */
850 xfs_fsblock_t fsbno, /* file system block number */
851 xfs_extlen_t count, /* count of filesystem blocks */
852 const struct xfs_buf_ops *ops)
854 xfs_daddr_t d;
856 ASSERT(fsbno != NULLFSBLOCK);
857 d = XFS_FSB_TO_DADDR(mp, fsbno);
858 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, ops);
862 * Read-ahead the block, don't wait for it, don't return a buffer.
863 * Short-form addressing.
865 /* ARGSUSED */
866 void
867 xfs_btree_reada_bufs(
868 struct xfs_mount *mp, /* file system mount point */
869 xfs_agnumber_t agno, /* allocation group number */
870 xfs_agblock_t agbno, /* allocation group block number */
871 xfs_extlen_t count, /* count of filesystem blocks */
872 const struct xfs_buf_ops *ops)
874 xfs_daddr_t d;
876 ASSERT(agno != NULLAGNUMBER);
877 ASSERT(agbno != NULLAGBLOCK);
878 d = XFS_AGB_TO_DADDR(mp, agno, agbno);
879 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, ops);
882 STATIC int
883 xfs_btree_readahead_lblock(
884 struct xfs_btree_cur *cur,
885 int lr,
886 struct xfs_btree_block *block)
888 int rval = 0;
889 xfs_fsblock_t left = be64_to_cpu(block->bb_u.l.bb_leftsib);
890 xfs_fsblock_t right = be64_to_cpu(block->bb_u.l.bb_rightsib);
892 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLFSBLOCK) {
893 xfs_btree_reada_bufl(cur->bc_mp, left, 1,
894 cur->bc_ops->buf_ops);
895 rval++;
898 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLFSBLOCK) {
899 xfs_btree_reada_bufl(cur->bc_mp, right, 1,
900 cur->bc_ops->buf_ops);
901 rval++;
904 return rval;
907 STATIC int
908 xfs_btree_readahead_sblock(
909 struct xfs_btree_cur *cur,
910 int lr,
911 struct xfs_btree_block *block)
913 int rval = 0;
914 xfs_agblock_t left = be32_to_cpu(block->bb_u.s.bb_leftsib);
915 xfs_agblock_t right = be32_to_cpu(block->bb_u.s.bb_rightsib);
918 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLAGBLOCK) {
919 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
920 left, 1, cur->bc_ops->buf_ops);
921 rval++;
924 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLAGBLOCK) {
925 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
926 right, 1, cur->bc_ops->buf_ops);
927 rval++;
930 return rval;
934 * Read-ahead btree blocks, at the given level.
935 * Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA.
937 STATIC int
938 xfs_btree_readahead(
939 struct xfs_btree_cur *cur, /* btree cursor */
940 int lev, /* level in btree */
941 int lr) /* left/right bits */
943 struct xfs_btree_block *block;
946 * No readahead needed if we are at the root level and the
947 * btree root is stored in the inode.
949 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
950 (lev == cur->bc_nlevels - 1))
951 return 0;
953 if ((cur->bc_ra[lev] | lr) == cur->bc_ra[lev])
954 return 0;
956 cur->bc_ra[lev] |= lr;
957 block = XFS_BUF_TO_BLOCK(cur->bc_bufs[lev]);
959 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
960 return xfs_btree_readahead_lblock(cur, lr, block);
961 return xfs_btree_readahead_sblock(cur, lr, block);
964 STATIC xfs_daddr_t
965 xfs_btree_ptr_to_daddr(
966 struct xfs_btree_cur *cur,
967 union xfs_btree_ptr *ptr)
969 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
970 ASSERT(ptr->l != cpu_to_be64(NULLFSBLOCK));
972 return XFS_FSB_TO_DADDR(cur->bc_mp, be64_to_cpu(ptr->l));
973 } else {
974 ASSERT(cur->bc_private.a.agno != NULLAGNUMBER);
975 ASSERT(ptr->s != cpu_to_be32(NULLAGBLOCK));
977 return XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_private.a.agno,
978 be32_to_cpu(ptr->s));
983 * Readahead @count btree blocks at the given @ptr location.
985 * We don't need to care about long or short form btrees here as we have a
986 * method of converting the ptr directly to a daddr available to us.
988 STATIC void
989 xfs_btree_readahead_ptr(
990 struct xfs_btree_cur *cur,
991 union xfs_btree_ptr *ptr,
992 xfs_extlen_t count)
994 xfs_buf_readahead(cur->bc_mp->m_ddev_targp,
995 xfs_btree_ptr_to_daddr(cur, ptr),
996 cur->bc_mp->m_bsize * count, cur->bc_ops->buf_ops);
1000 * Set the buffer for level "lev" in the cursor to bp, releasing
1001 * any previous buffer.
1003 STATIC void
1004 xfs_btree_setbuf(
1005 xfs_btree_cur_t *cur, /* btree cursor */
1006 int lev, /* level in btree */
1007 xfs_buf_t *bp) /* new buffer to set */
1009 struct xfs_btree_block *b; /* btree block */
1011 if (cur->bc_bufs[lev])
1012 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[lev]);
1013 cur->bc_bufs[lev] = bp;
1014 cur->bc_ra[lev] = 0;
1016 b = XFS_BUF_TO_BLOCK(bp);
1017 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1018 if (b->bb_u.l.bb_leftsib == cpu_to_be64(NULLFSBLOCK))
1019 cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
1020 if (b->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK))
1021 cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
1022 } else {
1023 if (b->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK))
1024 cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
1025 if (b->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK))
1026 cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
1030 STATIC int
1031 xfs_btree_ptr_is_null(
1032 struct xfs_btree_cur *cur,
1033 union xfs_btree_ptr *ptr)
1035 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1036 return ptr->l == cpu_to_be64(NULLFSBLOCK);
1037 else
1038 return ptr->s == cpu_to_be32(NULLAGBLOCK);
1041 STATIC void
1042 xfs_btree_set_ptr_null(
1043 struct xfs_btree_cur *cur,
1044 union xfs_btree_ptr *ptr)
1046 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1047 ptr->l = cpu_to_be64(NULLFSBLOCK);
1048 else
1049 ptr->s = cpu_to_be32(NULLAGBLOCK);
1053 * Get/set/init sibling pointers
1055 STATIC void
1056 xfs_btree_get_sibling(
1057 struct xfs_btree_cur *cur,
1058 struct xfs_btree_block *block,
1059 union xfs_btree_ptr *ptr,
1060 int lr)
1062 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
1064 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1065 if (lr == XFS_BB_RIGHTSIB)
1066 ptr->l = block->bb_u.l.bb_rightsib;
1067 else
1068 ptr->l = block->bb_u.l.bb_leftsib;
1069 } else {
1070 if (lr == XFS_BB_RIGHTSIB)
1071 ptr->s = block->bb_u.s.bb_rightsib;
1072 else
1073 ptr->s = block->bb_u.s.bb_leftsib;
1077 STATIC void
1078 xfs_btree_set_sibling(
1079 struct xfs_btree_cur *cur,
1080 struct xfs_btree_block *block,
1081 union xfs_btree_ptr *ptr,
1082 int lr)
1084 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
1086 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1087 if (lr == XFS_BB_RIGHTSIB)
1088 block->bb_u.l.bb_rightsib = ptr->l;
1089 else
1090 block->bb_u.l.bb_leftsib = ptr->l;
1091 } else {
1092 if (lr == XFS_BB_RIGHTSIB)
1093 block->bb_u.s.bb_rightsib = ptr->s;
1094 else
1095 block->bb_u.s.bb_leftsib = ptr->s;
1099 void
1100 xfs_btree_init_block_int(
1101 struct xfs_mount *mp,
1102 struct xfs_btree_block *buf,
1103 xfs_daddr_t blkno,
1104 xfs_btnum_t btnum,
1105 __u16 level,
1106 __u16 numrecs,
1107 __u64 owner,
1108 unsigned int flags)
1110 int crc = xfs_sb_version_hascrc(&mp->m_sb);
1111 __u32 magic = xfs_btree_magic(crc, btnum);
1113 buf->bb_magic = cpu_to_be32(magic);
1114 buf->bb_level = cpu_to_be16(level);
1115 buf->bb_numrecs = cpu_to_be16(numrecs);
1117 if (flags & XFS_BTREE_LONG_PTRS) {
1118 buf->bb_u.l.bb_leftsib = cpu_to_be64(NULLFSBLOCK);
1119 buf->bb_u.l.bb_rightsib = cpu_to_be64(NULLFSBLOCK);
1120 if (crc) {
1121 buf->bb_u.l.bb_blkno = cpu_to_be64(blkno);
1122 buf->bb_u.l.bb_owner = cpu_to_be64(owner);
1123 uuid_copy(&buf->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid);
1124 buf->bb_u.l.bb_pad = 0;
1125 buf->bb_u.l.bb_lsn = 0;
1127 } else {
1128 /* owner is a 32 bit value on short blocks */
1129 __u32 __owner = (__u32)owner;
1131 buf->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
1132 buf->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
1133 if (crc) {
1134 buf->bb_u.s.bb_blkno = cpu_to_be64(blkno);
1135 buf->bb_u.s.bb_owner = cpu_to_be32(__owner);
1136 uuid_copy(&buf->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid);
1137 buf->bb_u.s.bb_lsn = 0;
1142 void
1143 xfs_btree_init_block(
1144 struct xfs_mount *mp,
1145 struct xfs_buf *bp,
1146 xfs_btnum_t btnum,
1147 __u16 level,
1148 __u16 numrecs,
1149 __u64 owner,
1150 unsigned int flags)
1152 xfs_btree_init_block_int(mp, XFS_BUF_TO_BLOCK(bp), bp->b_bn,
1153 btnum, level, numrecs, owner, flags);
1156 STATIC void
1157 xfs_btree_init_block_cur(
1158 struct xfs_btree_cur *cur,
1159 struct xfs_buf *bp,
1160 int level,
1161 int numrecs)
1163 __u64 owner;
1166 * we can pull the owner from the cursor right now as the different
1167 * owners align directly with the pointer size of the btree. This may
1168 * change in future, but is safe for current users of the generic btree
1169 * code.
1171 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1172 owner = cur->bc_private.b.ip->i_ino;
1173 else
1174 owner = cur->bc_private.a.agno;
1176 xfs_btree_init_block_int(cur->bc_mp, XFS_BUF_TO_BLOCK(bp), bp->b_bn,
1177 cur->bc_btnum, level, numrecs,
1178 owner, cur->bc_flags);
1182 * Return true if ptr is the last record in the btree and
1183 * we need to track updates to this record. The decision
1184 * will be further refined in the update_lastrec method.
1186 STATIC int
1187 xfs_btree_is_lastrec(
1188 struct xfs_btree_cur *cur,
1189 struct xfs_btree_block *block,
1190 int level)
1192 union xfs_btree_ptr ptr;
1194 if (level > 0)
1195 return 0;
1196 if (!(cur->bc_flags & XFS_BTREE_LASTREC_UPDATE))
1197 return 0;
1199 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1200 if (!xfs_btree_ptr_is_null(cur, &ptr))
1201 return 0;
1202 return 1;
1205 STATIC void
1206 xfs_btree_buf_to_ptr(
1207 struct xfs_btree_cur *cur,
1208 struct xfs_buf *bp,
1209 union xfs_btree_ptr *ptr)
1211 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1212 ptr->l = cpu_to_be64(XFS_DADDR_TO_FSB(cur->bc_mp,
1213 XFS_BUF_ADDR(bp)));
1214 else {
1215 ptr->s = cpu_to_be32(xfs_daddr_to_agbno(cur->bc_mp,
1216 XFS_BUF_ADDR(bp)));
1220 STATIC void
1221 xfs_btree_set_refs(
1222 struct xfs_btree_cur *cur,
1223 struct xfs_buf *bp)
1225 switch (cur->bc_btnum) {
1226 case XFS_BTNUM_BNO:
1227 case XFS_BTNUM_CNT:
1228 xfs_buf_set_ref(bp, XFS_ALLOC_BTREE_REF);
1229 break;
1230 case XFS_BTNUM_INO:
1231 case XFS_BTNUM_FINO:
1232 xfs_buf_set_ref(bp, XFS_INO_BTREE_REF);
1233 break;
1234 case XFS_BTNUM_BMAP:
1235 xfs_buf_set_ref(bp, XFS_BMAP_BTREE_REF);
1236 break;
1237 case XFS_BTNUM_RMAP:
1238 xfs_buf_set_ref(bp, XFS_RMAP_BTREE_REF);
1239 break;
1240 case XFS_BTNUM_REFC:
1241 xfs_buf_set_ref(bp, XFS_REFC_BTREE_REF);
1242 break;
1243 default:
1244 ASSERT(0);
1248 STATIC int
1249 xfs_btree_get_buf_block(
1250 struct xfs_btree_cur *cur,
1251 union xfs_btree_ptr *ptr,
1252 int flags,
1253 struct xfs_btree_block **block,
1254 struct xfs_buf **bpp)
1256 struct xfs_mount *mp = cur->bc_mp;
1257 xfs_daddr_t d;
1259 /* need to sort out how callers deal with failures first */
1260 ASSERT(!(flags & XBF_TRYLOCK));
1262 d = xfs_btree_ptr_to_daddr(cur, ptr);
1263 *bpp = xfs_trans_get_buf(cur->bc_tp, mp->m_ddev_targp, d,
1264 mp->m_bsize, flags);
1266 if (!*bpp)
1267 return -ENOMEM;
1269 (*bpp)->b_ops = cur->bc_ops->buf_ops;
1270 *block = XFS_BUF_TO_BLOCK(*bpp);
1271 return 0;
1275 * Read in the buffer at the given ptr and return the buffer and
1276 * the block pointer within the buffer.
1278 STATIC int
1279 xfs_btree_read_buf_block(
1280 struct xfs_btree_cur *cur,
1281 union xfs_btree_ptr *ptr,
1282 int flags,
1283 struct xfs_btree_block **block,
1284 struct xfs_buf **bpp)
1286 struct xfs_mount *mp = cur->bc_mp;
1287 xfs_daddr_t d;
1288 int error;
1290 /* need to sort out how callers deal with failures first */
1291 ASSERT(!(flags & XBF_TRYLOCK));
1293 d = xfs_btree_ptr_to_daddr(cur, ptr);
1294 error = xfs_trans_read_buf(mp, cur->bc_tp, mp->m_ddev_targp, d,
1295 mp->m_bsize, flags, bpp,
1296 cur->bc_ops->buf_ops);
1297 if (error)
1298 return error;
1300 xfs_btree_set_refs(cur, *bpp);
1301 *block = XFS_BUF_TO_BLOCK(*bpp);
1302 return 0;
1306 * Copy keys from one btree block to another.
1308 STATIC void
1309 xfs_btree_copy_keys(
1310 struct xfs_btree_cur *cur,
1311 union xfs_btree_key *dst_key,
1312 union xfs_btree_key *src_key,
1313 int numkeys)
1315 ASSERT(numkeys >= 0);
1316 memcpy(dst_key, src_key, numkeys * cur->bc_ops->key_len);
1320 * Copy records from one btree block to another.
1322 STATIC void
1323 xfs_btree_copy_recs(
1324 struct xfs_btree_cur *cur,
1325 union xfs_btree_rec *dst_rec,
1326 union xfs_btree_rec *src_rec,
1327 int numrecs)
1329 ASSERT(numrecs >= 0);
1330 memcpy(dst_rec, src_rec, numrecs * cur->bc_ops->rec_len);
1334 * Copy block pointers from one btree block to another.
1336 STATIC void
1337 xfs_btree_copy_ptrs(
1338 struct xfs_btree_cur *cur,
1339 union xfs_btree_ptr *dst_ptr,
1340 union xfs_btree_ptr *src_ptr,
1341 int numptrs)
1343 ASSERT(numptrs >= 0);
1344 memcpy(dst_ptr, src_ptr, numptrs * xfs_btree_ptr_len(cur));
1348 * Shift keys one index left/right inside a single btree block.
1350 STATIC void
1351 xfs_btree_shift_keys(
1352 struct xfs_btree_cur *cur,
1353 union xfs_btree_key *key,
1354 int dir,
1355 int numkeys)
1357 char *dst_key;
1359 ASSERT(numkeys >= 0);
1360 ASSERT(dir == 1 || dir == -1);
1362 dst_key = (char *)key + (dir * cur->bc_ops->key_len);
1363 memmove(dst_key, key, numkeys * cur->bc_ops->key_len);
1367 * Shift records one index left/right inside a single btree block.
1369 STATIC void
1370 xfs_btree_shift_recs(
1371 struct xfs_btree_cur *cur,
1372 union xfs_btree_rec *rec,
1373 int dir,
1374 int numrecs)
1376 char *dst_rec;
1378 ASSERT(numrecs >= 0);
1379 ASSERT(dir == 1 || dir == -1);
1381 dst_rec = (char *)rec + (dir * cur->bc_ops->rec_len);
1382 memmove(dst_rec, rec, numrecs * cur->bc_ops->rec_len);
1386 * Shift block pointers one index left/right inside a single btree block.
1388 STATIC void
1389 xfs_btree_shift_ptrs(
1390 struct xfs_btree_cur *cur,
1391 union xfs_btree_ptr *ptr,
1392 int dir,
1393 int numptrs)
1395 char *dst_ptr;
1397 ASSERT(numptrs >= 0);
1398 ASSERT(dir == 1 || dir == -1);
1400 dst_ptr = (char *)ptr + (dir * xfs_btree_ptr_len(cur));
1401 memmove(dst_ptr, ptr, numptrs * xfs_btree_ptr_len(cur));
1405 * Log key values from the btree block.
1407 STATIC void
1408 xfs_btree_log_keys(
1409 struct xfs_btree_cur *cur,
1410 struct xfs_buf *bp,
1411 int first,
1412 int last)
1414 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1415 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1417 if (bp) {
1418 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1419 xfs_trans_log_buf(cur->bc_tp, bp,
1420 xfs_btree_key_offset(cur, first),
1421 xfs_btree_key_offset(cur, last + 1) - 1);
1422 } else {
1423 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1424 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1427 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1431 * Log record values from the btree block.
1433 void
1434 xfs_btree_log_recs(
1435 struct xfs_btree_cur *cur,
1436 struct xfs_buf *bp,
1437 int first,
1438 int last)
1440 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1441 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1443 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1444 xfs_trans_log_buf(cur->bc_tp, bp,
1445 xfs_btree_rec_offset(cur, first),
1446 xfs_btree_rec_offset(cur, last + 1) - 1);
1448 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1452 * Log block pointer fields from a btree block (nonleaf).
1454 STATIC void
1455 xfs_btree_log_ptrs(
1456 struct xfs_btree_cur *cur, /* btree cursor */
1457 struct xfs_buf *bp, /* buffer containing btree block */
1458 int first, /* index of first pointer to log */
1459 int last) /* index of last pointer to log */
1461 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1462 XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1464 if (bp) {
1465 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
1466 int level = xfs_btree_get_level(block);
1468 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1469 xfs_trans_log_buf(cur->bc_tp, bp,
1470 xfs_btree_ptr_offset(cur, first, level),
1471 xfs_btree_ptr_offset(cur, last + 1, level) - 1);
1472 } else {
1473 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1474 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1477 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1481 * Log fields from a btree block header.
1483 void
1484 xfs_btree_log_block(
1485 struct xfs_btree_cur *cur, /* btree cursor */
1486 struct xfs_buf *bp, /* buffer containing btree block */
1487 int fields) /* mask of fields: XFS_BB_... */
1489 int first; /* first byte offset logged */
1490 int last; /* last byte offset logged */
1491 static const short soffsets[] = { /* table of offsets (short) */
1492 offsetof(struct xfs_btree_block, bb_magic),
1493 offsetof(struct xfs_btree_block, bb_level),
1494 offsetof(struct xfs_btree_block, bb_numrecs),
1495 offsetof(struct xfs_btree_block, bb_u.s.bb_leftsib),
1496 offsetof(struct xfs_btree_block, bb_u.s.bb_rightsib),
1497 offsetof(struct xfs_btree_block, bb_u.s.bb_blkno),
1498 offsetof(struct xfs_btree_block, bb_u.s.bb_lsn),
1499 offsetof(struct xfs_btree_block, bb_u.s.bb_uuid),
1500 offsetof(struct xfs_btree_block, bb_u.s.bb_owner),
1501 offsetof(struct xfs_btree_block, bb_u.s.bb_crc),
1502 XFS_BTREE_SBLOCK_CRC_LEN
1504 static const short loffsets[] = { /* table of offsets (long) */
1505 offsetof(struct xfs_btree_block, bb_magic),
1506 offsetof(struct xfs_btree_block, bb_level),
1507 offsetof(struct xfs_btree_block, bb_numrecs),
1508 offsetof(struct xfs_btree_block, bb_u.l.bb_leftsib),
1509 offsetof(struct xfs_btree_block, bb_u.l.bb_rightsib),
1510 offsetof(struct xfs_btree_block, bb_u.l.bb_blkno),
1511 offsetof(struct xfs_btree_block, bb_u.l.bb_lsn),
1512 offsetof(struct xfs_btree_block, bb_u.l.bb_uuid),
1513 offsetof(struct xfs_btree_block, bb_u.l.bb_owner),
1514 offsetof(struct xfs_btree_block, bb_u.l.bb_crc),
1515 offsetof(struct xfs_btree_block, bb_u.l.bb_pad),
1516 XFS_BTREE_LBLOCK_CRC_LEN
1519 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1520 XFS_BTREE_TRACE_ARGBI(cur, bp, fields);
1522 if (bp) {
1523 int nbits;
1525 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) {
1527 * We don't log the CRC when updating a btree
1528 * block but instead recreate it during log
1529 * recovery. As the log buffers have checksums
1530 * of their own this is safe and avoids logging a crc
1531 * update in a lot of places.
1533 if (fields == XFS_BB_ALL_BITS)
1534 fields = XFS_BB_ALL_BITS_CRC;
1535 nbits = XFS_BB_NUM_BITS_CRC;
1536 } else {
1537 nbits = XFS_BB_NUM_BITS;
1539 xfs_btree_offsets(fields,
1540 (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
1541 loffsets : soffsets,
1542 nbits, &first, &last);
1543 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1544 xfs_trans_log_buf(cur->bc_tp, bp, first, last);
1545 } else {
1546 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1547 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1550 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1554 * Increment cursor by one record at the level.
1555 * For nonzero levels the leaf-ward information is untouched.
1557 int /* error */
1558 xfs_btree_increment(
1559 struct xfs_btree_cur *cur,
1560 int level,
1561 int *stat) /* success/failure */
1563 struct xfs_btree_block *block;
1564 union xfs_btree_ptr ptr;
1565 struct xfs_buf *bp;
1566 int error; /* error return value */
1567 int lev;
1569 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1570 XFS_BTREE_TRACE_ARGI(cur, level);
1572 ASSERT(level < cur->bc_nlevels);
1574 /* Read-ahead to the right at this level. */
1575 xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
1577 /* Get a pointer to the btree block. */
1578 block = xfs_btree_get_block(cur, level, &bp);
1580 #ifdef DEBUG
1581 error = xfs_btree_check_block(cur, block, level, bp);
1582 if (error)
1583 goto error0;
1584 #endif
1586 /* We're done if we remain in the block after the increment. */
1587 if (++cur->bc_ptrs[level] <= xfs_btree_get_numrecs(block))
1588 goto out1;
1590 /* Fail if we just went off the right edge of the tree. */
1591 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1592 if (xfs_btree_ptr_is_null(cur, &ptr))
1593 goto out0;
1595 XFS_BTREE_STATS_INC(cur, increment);
1598 * March up the tree incrementing pointers.
1599 * Stop when we don't go off the right edge of a block.
1601 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1602 block = xfs_btree_get_block(cur, lev, &bp);
1604 #ifdef DEBUG
1605 error = xfs_btree_check_block(cur, block, lev, bp);
1606 if (error)
1607 goto error0;
1608 #endif
1610 if (++cur->bc_ptrs[lev] <= xfs_btree_get_numrecs(block))
1611 break;
1613 /* Read-ahead the right block for the next loop. */
1614 xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA);
1618 * If we went off the root then we are either seriously
1619 * confused or have the tree root in an inode.
1621 if (lev == cur->bc_nlevels) {
1622 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1623 goto out0;
1624 ASSERT(0);
1625 error = -EFSCORRUPTED;
1626 goto error0;
1628 ASSERT(lev < cur->bc_nlevels);
1631 * Now walk back down the tree, fixing up the cursor's buffer
1632 * pointers and key numbers.
1634 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1635 union xfs_btree_ptr *ptrp;
1637 ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1638 --lev;
1639 error = xfs_btree_read_buf_block(cur, ptrp, 0, &block, &bp);
1640 if (error)
1641 goto error0;
1643 xfs_btree_setbuf(cur, lev, bp);
1644 cur->bc_ptrs[lev] = 1;
1646 out1:
1647 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1648 *stat = 1;
1649 return 0;
1651 out0:
1652 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1653 *stat = 0;
1654 return 0;
1656 error0:
1657 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1658 return error;
1662 * Decrement cursor by one record at the level.
1663 * For nonzero levels the leaf-ward information is untouched.
1665 int /* error */
1666 xfs_btree_decrement(
1667 struct xfs_btree_cur *cur,
1668 int level,
1669 int *stat) /* success/failure */
1671 struct xfs_btree_block *block;
1672 xfs_buf_t *bp;
1673 int error; /* error return value */
1674 int lev;
1675 union xfs_btree_ptr ptr;
1677 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1678 XFS_BTREE_TRACE_ARGI(cur, level);
1680 ASSERT(level < cur->bc_nlevels);
1682 /* Read-ahead to the left at this level. */
1683 xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA);
1685 /* We're done if we remain in the block after the decrement. */
1686 if (--cur->bc_ptrs[level] > 0)
1687 goto out1;
1689 /* Get a pointer to the btree block. */
1690 block = xfs_btree_get_block(cur, level, &bp);
1692 #ifdef DEBUG
1693 error = xfs_btree_check_block(cur, block, level, bp);
1694 if (error)
1695 goto error0;
1696 #endif
1698 /* Fail if we just went off the left edge of the tree. */
1699 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
1700 if (xfs_btree_ptr_is_null(cur, &ptr))
1701 goto out0;
1703 XFS_BTREE_STATS_INC(cur, decrement);
1706 * March up the tree decrementing pointers.
1707 * Stop when we don't go off the left edge of a block.
1709 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1710 if (--cur->bc_ptrs[lev] > 0)
1711 break;
1712 /* Read-ahead the left block for the next loop. */
1713 xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA);
1717 * If we went off the root then we are seriously confused.
1718 * or the root of the tree is in an inode.
1720 if (lev == cur->bc_nlevels) {
1721 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1722 goto out0;
1723 ASSERT(0);
1724 error = -EFSCORRUPTED;
1725 goto error0;
1727 ASSERT(lev < cur->bc_nlevels);
1730 * Now walk back down the tree, fixing up the cursor's buffer
1731 * pointers and key numbers.
1733 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1734 union xfs_btree_ptr *ptrp;
1736 ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1737 --lev;
1738 error = xfs_btree_read_buf_block(cur, ptrp, 0, &block, &bp);
1739 if (error)
1740 goto error0;
1741 xfs_btree_setbuf(cur, lev, bp);
1742 cur->bc_ptrs[lev] = xfs_btree_get_numrecs(block);
1744 out1:
1745 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1746 *stat = 1;
1747 return 0;
1749 out0:
1750 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1751 *stat = 0;
1752 return 0;
1754 error0:
1755 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1756 return error;
1760 xfs_btree_lookup_get_block(
1761 struct xfs_btree_cur *cur, /* btree cursor */
1762 int level, /* level in the btree */
1763 union xfs_btree_ptr *pp, /* ptr to btree block */
1764 struct xfs_btree_block **blkp) /* return btree block */
1766 struct xfs_buf *bp; /* buffer pointer for btree block */
1767 int error = 0;
1769 /* special case the root block if in an inode */
1770 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1771 (level == cur->bc_nlevels - 1)) {
1772 *blkp = xfs_btree_get_iroot(cur);
1773 return 0;
1777 * If the old buffer at this level for the disk address we are
1778 * looking for re-use it.
1780 * Otherwise throw it away and get a new one.
1782 bp = cur->bc_bufs[level];
1783 if (bp && XFS_BUF_ADDR(bp) == xfs_btree_ptr_to_daddr(cur, pp)) {
1784 *blkp = XFS_BUF_TO_BLOCK(bp);
1785 return 0;
1788 error = xfs_btree_read_buf_block(cur, pp, 0, blkp, &bp);
1789 if (error)
1790 return error;
1792 /* Check the inode owner since the verifiers don't. */
1793 if (xfs_sb_version_hascrc(&cur->bc_mp->m_sb) &&
1794 !(cur->bc_private.b.flags & XFS_BTCUR_BPRV_INVALID_OWNER) &&
1795 (cur->bc_flags & XFS_BTREE_LONG_PTRS) &&
1796 be64_to_cpu((*blkp)->bb_u.l.bb_owner) !=
1797 cur->bc_private.b.ip->i_ino)
1798 goto out_bad;
1800 /* Did we get the level we were looking for? */
1801 if (be16_to_cpu((*blkp)->bb_level) != level)
1802 goto out_bad;
1804 /* Check that internal nodes have at least one record. */
1805 if (level != 0 && be16_to_cpu((*blkp)->bb_numrecs) == 0)
1806 goto out_bad;
1808 xfs_btree_setbuf(cur, level, bp);
1809 return 0;
1811 out_bad:
1812 *blkp = NULL;
1813 xfs_trans_brelse(cur->bc_tp, bp);
1814 return -EFSCORRUPTED;
1818 * Get current search key. For level 0 we don't actually have a key
1819 * structure so we make one up from the record. For all other levels
1820 * we just return the right key.
1822 STATIC union xfs_btree_key *
1823 xfs_lookup_get_search_key(
1824 struct xfs_btree_cur *cur,
1825 int level,
1826 int keyno,
1827 struct xfs_btree_block *block,
1828 union xfs_btree_key *kp)
1830 if (level == 0) {
1831 cur->bc_ops->init_key_from_rec(kp,
1832 xfs_btree_rec_addr(cur, keyno, block));
1833 return kp;
1836 return xfs_btree_key_addr(cur, keyno, block);
1840 * Lookup the record. The cursor is made to point to it, based on dir.
1841 * stat is set to 0 if can't find any such record, 1 for success.
1843 int /* error */
1844 xfs_btree_lookup(
1845 struct xfs_btree_cur *cur, /* btree cursor */
1846 xfs_lookup_t dir, /* <=, ==, or >= */
1847 int *stat) /* success/failure */
1849 struct xfs_btree_block *block; /* current btree block */
1850 int64_t diff; /* difference for the current key */
1851 int error; /* error return value */
1852 int keyno; /* current key number */
1853 int level; /* level in the btree */
1854 union xfs_btree_ptr *pp; /* ptr to btree block */
1855 union xfs_btree_ptr ptr; /* ptr to btree block */
1857 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1858 XFS_BTREE_TRACE_ARGI(cur, dir);
1860 XFS_BTREE_STATS_INC(cur, lookup);
1862 /* No such thing as a zero-level tree. */
1863 if (cur->bc_nlevels == 0)
1864 return -EFSCORRUPTED;
1866 block = NULL;
1867 keyno = 0;
1869 /* initialise start pointer from cursor */
1870 cur->bc_ops->init_ptr_from_cur(cur, &ptr);
1871 pp = &ptr;
1874 * Iterate over each level in the btree, starting at the root.
1875 * For each level above the leaves, find the key we need, based
1876 * on the lookup record, then follow the corresponding block
1877 * pointer down to the next level.
1879 for (level = cur->bc_nlevels - 1, diff = 1; level >= 0; level--) {
1880 /* Get the block we need to do the lookup on. */
1881 error = xfs_btree_lookup_get_block(cur, level, pp, &block);
1882 if (error)
1883 goto error0;
1885 if (diff == 0) {
1887 * If we already had a key match at a higher level, we
1888 * know we need to use the first entry in this block.
1890 keyno = 1;
1891 } else {
1892 /* Otherwise search this block. Do a binary search. */
1894 int high; /* high entry number */
1895 int low; /* low entry number */
1897 /* Set low and high entry numbers, 1-based. */
1898 low = 1;
1899 high = xfs_btree_get_numrecs(block);
1900 if (!high) {
1901 /* Block is empty, must be an empty leaf. */
1902 ASSERT(level == 0 && cur->bc_nlevels == 1);
1904 cur->bc_ptrs[0] = dir != XFS_LOOKUP_LE;
1905 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1906 *stat = 0;
1907 return 0;
1910 /* Binary search the block. */
1911 while (low <= high) {
1912 union xfs_btree_key key;
1913 union xfs_btree_key *kp;
1915 XFS_BTREE_STATS_INC(cur, compare);
1917 /* keyno is average of low and high. */
1918 keyno = (low + high) >> 1;
1920 /* Get current search key */
1921 kp = xfs_lookup_get_search_key(cur, level,
1922 keyno, block, &key);
1925 * Compute difference to get next direction:
1926 * - less than, move right
1927 * - greater than, move left
1928 * - equal, we're done
1930 diff = cur->bc_ops->key_diff(cur, kp);
1931 if (diff < 0)
1932 low = keyno + 1;
1933 else if (diff > 0)
1934 high = keyno - 1;
1935 else
1936 break;
1941 * If there are more levels, set up for the next level
1942 * by getting the block number and filling in the cursor.
1944 if (level > 0) {
1946 * If we moved left, need the previous key number,
1947 * unless there isn't one.
1949 if (diff > 0 && --keyno < 1)
1950 keyno = 1;
1951 pp = xfs_btree_ptr_addr(cur, keyno, block);
1953 #ifdef DEBUG
1954 error = xfs_btree_check_ptr(cur, pp, 0, level);
1955 if (error)
1956 goto error0;
1957 #endif
1958 cur->bc_ptrs[level] = keyno;
1962 /* Done with the search. See if we need to adjust the results. */
1963 if (dir != XFS_LOOKUP_LE && diff < 0) {
1964 keyno++;
1966 * If ge search and we went off the end of the block, but it's
1967 * not the last block, we're in the wrong block.
1969 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1970 if (dir == XFS_LOOKUP_GE &&
1971 keyno > xfs_btree_get_numrecs(block) &&
1972 !xfs_btree_ptr_is_null(cur, &ptr)) {
1973 int i;
1975 cur->bc_ptrs[0] = keyno;
1976 error = xfs_btree_increment(cur, 0, &i);
1977 if (error)
1978 goto error0;
1979 XFS_WANT_CORRUPTED_RETURN(cur->bc_mp, i == 1);
1980 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1981 *stat = 1;
1982 return 0;
1984 } else if (dir == XFS_LOOKUP_LE && diff > 0)
1985 keyno--;
1986 cur->bc_ptrs[0] = keyno;
1988 /* Return if we succeeded or not. */
1989 if (keyno == 0 || keyno > xfs_btree_get_numrecs(block))
1990 *stat = 0;
1991 else if (dir != XFS_LOOKUP_EQ || diff == 0)
1992 *stat = 1;
1993 else
1994 *stat = 0;
1995 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1996 return 0;
1998 error0:
1999 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2000 return error;
2003 /* Find the high key storage area from a regular key. */
2004 STATIC union xfs_btree_key *
2005 xfs_btree_high_key_from_key(
2006 struct xfs_btree_cur *cur,
2007 union xfs_btree_key *key)
2009 ASSERT(cur->bc_flags & XFS_BTREE_OVERLAPPING);
2010 return (union xfs_btree_key *)((char *)key +
2011 (cur->bc_ops->key_len / 2));
2014 /* Determine the low (and high if overlapped) keys of a leaf block */
2015 STATIC void
2016 xfs_btree_get_leaf_keys(
2017 struct xfs_btree_cur *cur,
2018 struct xfs_btree_block *block,
2019 union xfs_btree_key *key)
2021 union xfs_btree_key max_hkey;
2022 union xfs_btree_key hkey;
2023 union xfs_btree_rec *rec;
2024 union xfs_btree_key *high;
2025 int n;
2027 rec = xfs_btree_rec_addr(cur, 1, block);
2028 cur->bc_ops->init_key_from_rec(key, rec);
2030 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2032 cur->bc_ops->init_high_key_from_rec(&max_hkey, rec);
2033 for (n = 2; n <= xfs_btree_get_numrecs(block); n++) {
2034 rec = xfs_btree_rec_addr(cur, n, block);
2035 cur->bc_ops->init_high_key_from_rec(&hkey, rec);
2036 if (cur->bc_ops->diff_two_keys(cur, &hkey, &max_hkey)
2037 > 0)
2038 max_hkey = hkey;
2041 high = xfs_btree_high_key_from_key(cur, key);
2042 memcpy(high, &max_hkey, cur->bc_ops->key_len / 2);
2046 /* Determine the low (and high if overlapped) keys of a node block */
2047 STATIC void
2048 xfs_btree_get_node_keys(
2049 struct xfs_btree_cur *cur,
2050 struct xfs_btree_block *block,
2051 union xfs_btree_key *key)
2053 union xfs_btree_key *hkey;
2054 union xfs_btree_key *max_hkey;
2055 union xfs_btree_key *high;
2056 int n;
2058 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2059 memcpy(key, xfs_btree_key_addr(cur, 1, block),
2060 cur->bc_ops->key_len / 2);
2062 max_hkey = xfs_btree_high_key_addr(cur, 1, block);
2063 for (n = 2; n <= xfs_btree_get_numrecs(block); n++) {
2064 hkey = xfs_btree_high_key_addr(cur, n, block);
2065 if (cur->bc_ops->diff_two_keys(cur, hkey, max_hkey) > 0)
2066 max_hkey = hkey;
2069 high = xfs_btree_high_key_from_key(cur, key);
2070 memcpy(high, max_hkey, cur->bc_ops->key_len / 2);
2071 } else {
2072 memcpy(key, xfs_btree_key_addr(cur, 1, block),
2073 cur->bc_ops->key_len);
2077 /* Derive the keys for any btree block. */
2078 STATIC void
2079 xfs_btree_get_keys(
2080 struct xfs_btree_cur *cur,
2081 struct xfs_btree_block *block,
2082 union xfs_btree_key *key)
2084 if (be16_to_cpu(block->bb_level) == 0)
2085 xfs_btree_get_leaf_keys(cur, block, key);
2086 else
2087 xfs_btree_get_node_keys(cur, block, key);
2091 * Decide if we need to update the parent keys of a btree block. For
2092 * a standard btree this is only necessary if we're updating the first
2093 * record/key. For an overlapping btree, we must always update the
2094 * keys because the highest key can be in any of the records or keys
2095 * in the block.
2097 static inline bool
2098 xfs_btree_needs_key_update(
2099 struct xfs_btree_cur *cur,
2100 int ptr)
2102 return (cur->bc_flags & XFS_BTREE_OVERLAPPING) || ptr == 1;
2106 * Update the low and high parent keys of the given level, progressing
2107 * towards the root. If force_all is false, stop if the keys for a given
2108 * level do not need updating.
2110 STATIC int
2111 __xfs_btree_updkeys(
2112 struct xfs_btree_cur *cur,
2113 int level,
2114 struct xfs_btree_block *block,
2115 struct xfs_buf *bp0,
2116 bool force_all)
2118 union xfs_btree_key key; /* keys from current level */
2119 union xfs_btree_key *lkey; /* keys from the next level up */
2120 union xfs_btree_key *hkey;
2121 union xfs_btree_key *nlkey; /* keys from the next level up */
2122 union xfs_btree_key *nhkey;
2123 struct xfs_buf *bp;
2124 int ptr;
2126 ASSERT(cur->bc_flags & XFS_BTREE_OVERLAPPING);
2128 /* Exit if there aren't any parent levels to update. */
2129 if (level + 1 >= cur->bc_nlevels)
2130 return 0;
2132 trace_xfs_btree_updkeys(cur, level, bp0);
2134 lkey = &key;
2135 hkey = xfs_btree_high_key_from_key(cur, lkey);
2136 xfs_btree_get_keys(cur, block, lkey);
2137 for (level++; level < cur->bc_nlevels; level++) {
2138 #ifdef DEBUG
2139 int error;
2140 #endif
2141 block = xfs_btree_get_block(cur, level, &bp);
2142 trace_xfs_btree_updkeys(cur, level, bp);
2143 #ifdef DEBUG
2144 error = xfs_btree_check_block(cur, block, level, bp);
2145 if (error) {
2146 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2147 return error;
2149 #endif
2150 ptr = cur->bc_ptrs[level];
2151 nlkey = xfs_btree_key_addr(cur, ptr, block);
2152 nhkey = xfs_btree_high_key_addr(cur, ptr, block);
2153 if (!force_all &&
2154 !(cur->bc_ops->diff_two_keys(cur, nlkey, lkey) != 0 ||
2155 cur->bc_ops->diff_two_keys(cur, nhkey, hkey) != 0))
2156 break;
2157 xfs_btree_copy_keys(cur, nlkey, lkey, 1);
2158 xfs_btree_log_keys(cur, bp, ptr, ptr);
2159 if (level + 1 >= cur->bc_nlevels)
2160 break;
2161 xfs_btree_get_node_keys(cur, block, lkey);
2164 return 0;
2167 /* Update all the keys from some level in cursor back to the root. */
2168 STATIC int
2169 xfs_btree_updkeys_force(
2170 struct xfs_btree_cur *cur,
2171 int level)
2173 struct xfs_buf *bp;
2174 struct xfs_btree_block *block;
2176 block = xfs_btree_get_block(cur, level, &bp);
2177 return __xfs_btree_updkeys(cur, level, block, bp, true);
2181 * Update the parent keys of the given level, progressing towards the root.
2183 STATIC int
2184 xfs_btree_update_keys(
2185 struct xfs_btree_cur *cur,
2186 int level)
2188 struct xfs_btree_block *block;
2189 struct xfs_buf *bp;
2190 union xfs_btree_key *kp;
2191 union xfs_btree_key key;
2192 int ptr;
2194 ASSERT(level >= 0);
2196 block = xfs_btree_get_block(cur, level, &bp);
2197 if (cur->bc_flags & XFS_BTREE_OVERLAPPING)
2198 return __xfs_btree_updkeys(cur, level, block, bp, false);
2200 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2201 XFS_BTREE_TRACE_ARGIK(cur, level, keyp);
2204 * Go up the tree from this level toward the root.
2205 * At each level, update the key value to the value input.
2206 * Stop when we reach a level where the cursor isn't pointing
2207 * at the first entry in the block.
2209 xfs_btree_get_keys(cur, block, &key);
2210 for (level++, ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) {
2211 #ifdef DEBUG
2212 int error;
2213 #endif
2214 block = xfs_btree_get_block(cur, level, &bp);
2215 #ifdef DEBUG
2216 error = xfs_btree_check_block(cur, block, level, bp);
2217 if (error) {
2218 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2219 return error;
2221 #endif
2222 ptr = cur->bc_ptrs[level];
2223 kp = xfs_btree_key_addr(cur, ptr, block);
2224 xfs_btree_copy_keys(cur, kp, &key, 1);
2225 xfs_btree_log_keys(cur, bp, ptr, ptr);
2228 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2229 return 0;
2233 * Update the record referred to by cur to the value in the
2234 * given record. This either works (return 0) or gets an
2235 * EFSCORRUPTED error.
2238 xfs_btree_update(
2239 struct xfs_btree_cur *cur,
2240 union xfs_btree_rec *rec)
2242 struct xfs_btree_block *block;
2243 struct xfs_buf *bp;
2244 int error;
2245 int ptr;
2246 union xfs_btree_rec *rp;
2248 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2249 XFS_BTREE_TRACE_ARGR(cur, rec);
2251 /* Pick up the current block. */
2252 block = xfs_btree_get_block(cur, 0, &bp);
2254 #ifdef DEBUG
2255 error = xfs_btree_check_block(cur, block, 0, bp);
2256 if (error)
2257 goto error0;
2258 #endif
2259 /* Get the address of the rec to be updated. */
2260 ptr = cur->bc_ptrs[0];
2261 rp = xfs_btree_rec_addr(cur, ptr, block);
2263 /* Fill in the new contents and log them. */
2264 xfs_btree_copy_recs(cur, rp, rec, 1);
2265 xfs_btree_log_recs(cur, bp, ptr, ptr);
2268 * If we are tracking the last record in the tree and
2269 * we are at the far right edge of the tree, update it.
2271 if (xfs_btree_is_lastrec(cur, block, 0)) {
2272 cur->bc_ops->update_lastrec(cur, block, rec,
2273 ptr, LASTREC_UPDATE);
2276 /* Pass new key value up to our parent. */
2277 if (xfs_btree_needs_key_update(cur, ptr)) {
2278 error = xfs_btree_update_keys(cur, 0);
2279 if (error)
2280 goto error0;
2283 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2284 return 0;
2286 error0:
2287 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2288 return error;
2292 * Move 1 record left from cur/level if possible.
2293 * Update cur to reflect the new path.
2295 STATIC int /* error */
2296 xfs_btree_lshift(
2297 struct xfs_btree_cur *cur,
2298 int level,
2299 int *stat) /* success/failure */
2301 struct xfs_buf *lbp; /* left buffer pointer */
2302 struct xfs_btree_block *left; /* left btree block */
2303 int lrecs; /* left record count */
2304 struct xfs_buf *rbp; /* right buffer pointer */
2305 struct xfs_btree_block *right; /* right btree block */
2306 struct xfs_btree_cur *tcur; /* temporary btree cursor */
2307 int rrecs; /* right record count */
2308 union xfs_btree_ptr lptr; /* left btree pointer */
2309 union xfs_btree_key *rkp = NULL; /* right btree key */
2310 union xfs_btree_ptr *rpp = NULL; /* right address pointer */
2311 union xfs_btree_rec *rrp = NULL; /* right record pointer */
2312 int error; /* error return value */
2313 int i;
2315 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2316 XFS_BTREE_TRACE_ARGI(cur, level);
2318 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2319 level == cur->bc_nlevels - 1)
2320 goto out0;
2322 /* Set up variables for this block as "right". */
2323 right = xfs_btree_get_block(cur, level, &rbp);
2325 #ifdef DEBUG
2326 error = xfs_btree_check_block(cur, right, level, rbp);
2327 if (error)
2328 goto error0;
2329 #endif
2331 /* If we've got no left sibling then we can't shift an entry left. */
2332 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2333 if (xfs_btree_ptr_is_null(cur, &lptr))
2334 goto out0;
2337 * If the cursor entry is the one that would be moved, don't
2338 * do it... it's too complicated.
2340 if (cur->bc_ptrs[level] <= 1)
2341 goto out0;
2343 /* Set up the left neighbor as "left". */
2344 error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
2345 if (error)
2346 goto error0;
2348 /* If it's full, it can't take another entry. */
2349 lrecs = xfs_btree_get_numrecs(left);
2350 if (lrecs == cur->bc_ops->get_maxrecs(cur, level))
2351 goto out0;
2353 rrecs = xfs_btree_get_numrecs(right);
2356 * We add one entry to the left side and remove one for the right side.
2357 * Account for it here, the changes will be updated on disk and logged
2358 * later.
2360 lrecs++;
2361 rrecs--;
2363 XFS_BTREE_STATS_INC(cur, lshift);
2364 XFS_BTREE_STATS_ADD(cur, moves, 1);
2367 * If non-leaf, copy a key and a ptr to the left block.
2368 * Log the changes to the left block.
2370 if (level > 0) {
2371 /* It's a non-leaf. Move keys and pointers. */
2372 union xfs_btree_key *lkp; /* left btree key */
2373 union xfs_btree_ptr *lpp; /* left address pointer */
2375 lkp = xfs_btree_key_addr(cur, lrecs, left);
2376 rkp = xfs_btree_key_addr(cur, 1, right);
2378 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2379 rpp = xfs_btree_ptr_addr(cur, 1, right);
2380 #ifdef DEBUG
2381 error = xfs_btree_check_ptr(cur, rpp, 0, level);
2382 if (error)
2383 goto error0;
2384 #endif
2385 xfs_btree_copy_keys(cur, lkp, rkp, 1);
2386 xfs_btree_copy_ptrs(cur, lpp, rpp, 1);
2388 xfs_btree_log_keys(cur, lbp, lrecs, lrecs);
2389 xfs_btree_log_ptrs(cur, lbp, lrecs, lrecs);
2391 ASSERT(cur->bc_ops->keys_inorder(cur,
2392 xfs_btree_key_addr(cur, lrecs - 1, left), lkp));
2393 } else {
2394 /* It's a leaf. Move records. */
2395 union xfs_btree_rec *lrp; /* left record pointer */
2397 lrp = xfs_btree_rec_addr(cur, lrecs, left);
2398 rrp = xfs_btree_rec_addr(cur, 1, right);
2400 xfs_btree_copy_recs(cur, lrp, rrp, 1);
2401 xfs_btree_log_recs(cur, lbp, lrecs, lrecs);
2403 ASSERT(cur->bc_ops->recs_inorder(cur,
2404 xfs_btree_rec_addr(cur, lrecs - 1, left), lrp));
2407 xfs_btree_set_numrecs(left, lrecs);
2408 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2410 xfs_btree_set_numrecs(right, rrecs);
2411 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2414 * Slide the contents of right down one entry.
2416 XFS_BTREE_STATS_ADD(cur, moves, rrecs - 1);
2417 if (level > 0) {
2418 /* It's a nonleaf. operate on keys and ptrs */
2419 #ifdef DEBUG
2420 int i; /* loop index */
2422 for (i = 0; i < rrecs; i++) {
2423 error = xfs_btree_check_ptr(cur, rpp, i + 1, level);
2424 if (error)
2425 goto error0;
2427 #endif
2428 xfs_btree_shift_keys(cur,
2429 xfs_btree_key_addr(cur, 2, right),
2430 -1, rrecs);
2431 xfs_btree_shift_ptrs(cur,
2432 xfs_btree_ptr_addr(cur, 2, right),
2433 -1, rrecs);
2435 xfs_btree_log_keys(cur, rbp, 1, rrecs);
2436 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2437 } else {
2438 /* It's a leaf. operate on records */
2439 xfs_btree_shift_recs(cur,
2440 xfs_btree_rec_addr(cur, 2, right),
2441 -1, rrecs);
2442 xfs_btree_log_recs(cur, rbp, 1, rrecs);
2446 * Using a temporary cursor, update the parent key values of the
2447 * block on the left.
2449 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2450 error = xfs_btree_dup_cursor(cur, &tcur);
2451 if (error)
2452 goto error0;
2453 i = xfs_btree_firstrec(tcur, level);
2454 XFS_WANT_CORRUPTED_GOTO(tcur->bc_mp, i == 1, error0);
2456 error = xfs_btree_decrement(tcur, level, &i);
2457 if (error)
2458 goto error1;
2460 /* Update the parent high keys of the left block, if needed. */
2461 error = xfs_btree_update_keys(tcur, level);
2462 if (error)
2463 goto error1;
2465 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
2468 /* Update the parent keys of the right block. */
2469 error = xfs_btree_update_keys(cur, level);
2470 if (error)
2471 goto error0;
2473 /* Slide the cursor value left one. */
2474 cur->bc_ptrs[level]--;
2476 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2477 *stat = 1;
2478 return 0;
2480 out0:
2481 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2482 *stat = 0;
2483 return 0;
2485 error0:
2486 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2487 return error;
2489 error1:
2490 XFS_BTREE_TRACE_CURSOR(tcur, XBT_ERROR);
2491 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
2492 return error;
2496 * Move 1 record right from cur/level if possible.
2497 * Update cur to reflect the new path.
2499 STATIC int /* error */
2500 xfs_btree_rshift(
2501 struct xfs_btree_cur *cur,
2502 int level,
2503 int *stat) /* success/failure */
2505 struct xfs_buf *lbp; /* left buffer pointer */
2506 struct xfs_btree_block *left; /* left btree block */
2507 struct xfs_buf *rbp; /* right buffer pointer */
2508 struct xfs_btree_block *right; /* right btree block */
2509 struct xfs_btree_cur *tcur; /* temporary btree cursor */
2510 union xfs_btree_ptr rptr; /* right block pointer */
2511 union xfs_btree_key *rkp; /* right btree key */
2512 int rrecs; /* right record count */
2513 int lrecs; /* left record count */
2514 int error; /* error return value */
2515 int i; /* loop counter */
2517 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2518 XFS_BTREE_TRACE_ARGI(cur, level);
2520 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2521 (level == cur->bc_nlevels - 1))
2522 goto out0;
2524 /* Set up variables for this block as "left". */
2525 left = xfs_btree_get_block(cur, level, &lbp);
2527 #ifdef DEBUG
2528 error = xfs_btree_check_block(cur, left, level, lbp);
2529 if (error)
2530 goto error0;
2531 #endif
2533 /* If we've got no right sibling then we can't shift an entry right. */
2534 xfs_btree_get_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2535 if (xfs_btree_ptr_is_null(cur, &rptr))
2536 goto out0;
2539 * If the cursor entry is the one that would be moved, don't
2540 * do it... it's too complicated.
2542 lrecs = xfs_btree_get_numrecs(left);
2543 if (cur->bc_ptrs[level] >= lrecs)
2544 goto out0;
2546 /* Set up the right neighbor as "right". */
2547 error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
2548 if (error)
2549 goto error0;
2551 /* If it's full, it can't take another entry. */
2552 rrecs = xfs_btree_get_numrecs(right);
2553 if (rrecs == cur->bc_ops->get_maxrecs(cur, level))
2554 goto out0;
2556 XFS_BTREE_STATS_INC(cur, rshift);
2557 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2560 * Make a hole at the start of the right neighbor block, then
2561 * copy the last left block entry to the hole.
2563 if (level > 0) {
2564 /* It's a nonleaf. make a hole in the keys and ptrs */
2565 union xfs_btree_key *lkp;
2566 union xfs_btree_ptr *lpp;
2567 union xfs_btree_ptr *rpp;
2569 lkp = xfs_btree_key_addr(cur, lrecs, left);
2570 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2571 rkp = xfs_btree_key_addr(cur, 1, right);
2572 rpp = xfs_btree_ptr_addr(cur, 1, right);
2574 #ifdef DEBUG
2575 for (i = rrecs - 1; i >= 0; i--) {
2576 error = xfs_btree_check_ptr(cur, rpp, i, level);
2577 if (error)
2578 goto error0;
2580 #endif
2582 xfs_btree_shift_keys(cur, rkp, 1, rrecs);
2583 xfs_btree_shift_ptrs(cur, rpp, 1, rrecs);
2585 #ifdef DEBUG
2586 error = xfs_btree_check_ptr(cur, lpp, 0, level);
2587 if (error)
2588 goto error0;
2589 #endif
2591 /* Now put the new data in, and log it. */
2592 xfs_btree_copy_keys(cur, rkp, lkp, 1);
2593 xfs_btree_copy_ptrs(cur, rpp, lpp, 1);
2595 xfs_btree_log_keys(cur, rbp, 1, rrecs + 1);
2596 xfs_btree_log_ptrs(cur, rbp, 1, rrecs + 1);
2598 ASSERT(cur->bc_ops->keys_inorder(cur, rkp,
2599 xfs_btree_key_addr(cur, 2, right)));
2600 } else {
2601 /* It's a leaf. make a hole in the records */
2602 union xfs_btree_rec *lrp;
2603 union xfs_btree_rec *rrp;
2605 lrp = xfs_btree_rec_addr(cur, lrecs, left);
2606 rrp = xfs_btree_rec_addr(cur, 1, right);
2608 xfs_btree_shift_recs(cur, rrp, 1, rrecs);
2610 /* Now put the new data in, and log it. */
2611 xfs_btree_copy_recs(cur, rrp, lrp, 1);
2612 xfs_btree_log_recs(cur, rbp, 1, rrecs + 1);
2616 * Decrement and log left's numrecs, bump and log right's numrecs.
2618 xfs_btree_set_numrecs(left, --lrecs);
2619 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2621 xfs_btree_set_numrecs(right, ++rrecs);
2622 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2625 * Using a temporary cursor, update the parent key values of the
2626 * block on the right.
2628 error = xfs_btree_dup_cursor(cur, &tcur);
2629 if (error)
2630 goto error0;
2631 i = xfs_btree_lastrec(tcur, level);
2632 XFS_WANT_CORRUPTED_GOTO(tcur->bc_mp, i == 1, error0);
2634 error = xfs_btree_increment(tcur, level, &i);
2635 if (error)
2636 goto error1;
2638 /* Update the parent high keys of the left block, if needed. */
2639 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2640 error = xfs_btree_update_keys(cur, level);
2641 if (error)
2642 goto error1;
2645 /* Update the parent keys of the right block. */
2646 error = xfs_btree_update_keys(tcur, level);
2647 if (error)
2648 goto error1;
2650 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
2652 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2653 *stat = 1;
2654 return 0;
2656 out0:
2657 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2658 *stat = 0;
2659 return 0;
2661 error0:
2662 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2663 return error;
2665 error1:
2666 XFS_BTREE_TRACE_CURSOR(tcur, XBT_ERROR);
2667 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
2668 return error;
2672 * Split cur/level block in half.
2673 * Return new block number and the key to its first
2674 * record (to be inserted into parent).
2676 STATIC int /* error */
2677 __xfs_btree_split(
2678 struct xfs_btree_cur *cur,
2679 int level,
2680 union xfs_btree_ptr *ptrp,
2681 union xfs_btree_key *key,
2682 struct xfs_btree_cur **curp,
2683 int *stat) /* success/failure */
2685 union xfs_btree_ptr lptr; /* left sibling block ptr */
2686 struct xfs_buf *lbp; /* left buffer pointer */
2687 struct xfs_btree_block *left; /* left btree block */
2688 union xfs_btree_ptr rptr; /* right sibling block ptr */
2689 struct xfs_buf *rbp; /* right buffer pointer */
2690 struct xfs_btree_block *right; /* right btree block */
2691 union xfs_btree_ptr rrptr; /* right-right sibling ptr */
2692 struct xfs_buf *rrbp; /* right-right buffer pointer */
2693 struct xfs_btree_block *rrblock; /* right-right btree block */
2694 int lrecs;
2695 int rrecs;
2696 int src_index;
2697 int error; /* error return value */
2698 #ifdef DEBUG
2699 int i;
2700 #endif
2702 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2703 XFS_BTREE_TRACE_ARGIPK(cur, level, *ptrp, key);
2705 XFS_BTREE_STATS_INC(cur, split);
2707 /* Set up left block (current one). */
2708 left = xfs_btree_get_block(cur, level, &lbp);
2710 #ifdef DEBUG
2711 error = xfs_btree_check_block(cur, left, level, lbp);
2712 if (error)
2713 goto error0;
2714 #endif
2716 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2718 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2719 error = cur->bc_ops->alloc_block(cur, &lptr, &rptr, stat);
2720 if (error)
2721 goto error0;
2722 if (*stat == 0)
2723 goto out0;
2724 XFS_BTREE_STATS_INC(cur, alloc);
2726 /* Set up the new block as "right". */
2727 error = xfs_btree_get_buf_block(cur, &rptr, 0, &right, &rbp);
2728 if (error)
2729 goto error0;
2731 /* Fill in the btree header for the new right block. */
2732 xfs_btree_init_block_cur(cur, rbp, xfs_btree_get_level(left), 0);
2735 * Split the entries between the old and the new block evenly.
2736 * Make sure that if there's an odd number of entries now, that
2737 * each new block will have the same number of entries.
2739 lrecs = xfs_btree_get_numrecs(left);
2740 rrecs = lrecs / 2;
2741 if ((lrecs & 1) && cur->bc_ptrs[level] <= rrecs + 1)
2742 rrecs++;
2743 src_index = (lrecs - rrecs + 1);
2745 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2747 /* Adjust numrecs for the later get_*_keys() calls. */
2748 lrecs -= rrecs;
2749 xfs_btree_set_numrecs(left, lrecs);
2750 xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs);
2753 * Copy btree block entries from the left block over to the
2754 * new block, the right. Update the right block and log the
2755 * changes.
2757 if (level > 0) {
2758 /* It's a non-leaf. Move keys and pointers. */
2759 union xfs_btree_key *lkp; /* left btree key */
2760 union xfs_btree_ptr *lpp; /* left address pointer */
2761 union xfs_btree_key *rkp; /* right btree key */
2762 union xfs_btree_ptr *rpp; /* right address pointer */
2764 lkp = xfs_btree_key_addr(cur, src_index, left);
2765 lpp = xfs_btree_ptr_addr(cur, src_index, left);
2766 rkp = xfs_btree_key_addr(cur, 1, right);
2767 rpp = xfs_btree_ptr_addr(cur, 1, right);
2769 #ifdef DEBUG
2770 for (i = src_index; i < rrecs; i++) {
2771 error = xfs_btree_check_ptr(cur, lpp, i, level);
2772 if (error)
2773 goto error0;
2775 #endif
2777 /* Copy the keys & pointers to the new block. */
2778 xfs_btree_copy_keys(cur, rkp, lkp, rrecs);
2779 xfs_btree_copy_ptrs(cur, rpp, lpp, rrecs);
2781 xfs_btree_log_keys(cur, rbp, 1, rrecs);
2782 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2784 /* Stash the keys of the new block for later insertion. */
2785 xfs_btree_get_node_keys(cur, right, key);
2786 } else {
2787 /* It's a leaf. Move records. */
2788 union xfs_btree_rec *lrp; /* left record pointer */
2789 union xfs_btree_rec *rrp; /* right record pointer */
2791 lrp = xfs_btree_rec_addr(cur, src_index, left);
2792 rrp = xfs_btree_rec_addr(cur, 1, right);
2794 /* Copy records to the new block. */
2795 xfs_btree_copy_recs(cur, rrp, lrp, rrecs);
2796 xfs_btree_log_recs(cur, rbp, 1, rrecs);
2798 /* Stash the keys of the new block for later insertion. */
2799 xfs_btree_get_leaf_keys(cur, right, key);
2803 * Find the left block number by looking in the buffer.
2804 * Adjust sibling pointers.
2806 xfs_btree_get_sibling(cur, left, &rrptr, XFS_BB_RIGHTSIB);
2807 xfs_btree_set_sibling(cur, right, &rrptr, XFS_BB_RIGHTSIB);
2808 xfs_btree_set_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2809 xfs_btree_set_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2811 xfs_btree_log_block(cur, rbp, XFS_BB_ALL_BITS);
2812 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
2815 * If there's a block to the new block's right, make that block
2816 * point back to right instead of to left.
2818 if (!xfs_btree_ptr_is_null(cur, &rrptr)) {
2819 error = xfs_btree_read_buf_block(cur, &rrptr,
2820 0, &rrblock, &rrbp);
2821 if (error)
2822 goto error0;
2823 xfs_btree_set_sibling(cur, rrblock, &rptr, XFS_BB_LEFTSIB);
2824 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
2827 /* Update the parent high keys of the left block, if needed. */
2828 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2829 error = xfs_btree_update_keys(cur, level);
2830 if (error)
2831 goto error0;
2835 * If the cursor is really in the right block, move it there.
2836 * If it's just pointing past the last entry in left, then we'll
2837 * insert there, so don't change anything in that case.
2839 if (cur->bc_ptrs[level] > lrecs + 1) {
2840 xfs_btree_setbuf(cur, level, rbp);
2841 cur->bc_ptrs[level] -= lrecs;
2844 * If there are more levels, we'll need another cursor which refers
2845 * the right block, no matter where this cursor was.
2847 if (level + 1 < cur->bc_nlevels) {
2848 error = xfs_btree_dup_cursor(cur, curp);
2849 if (error)
2850 goto error0;
2851 (*curp)->bc_ptrs[level + 1]++;
2853 *ptrp = rptr;
2854 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2855 *stat = 1;
2856 return 0;
2857 out0:
2858 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2859 *stat = 0;
2860 return 0;
2862 error0:
2863 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2864 return error;
2867 struct xfs_btree_split_args {
2868 struct xfs_btree_cur *cur;
2869 int level;
2870 union xfs_btree_ptr *ptrp;
2871 union xfs_btree_key *key;
2872 struct xfs_btree_cur **curp;
2873 int *stat; /* success/failure */
2874 int result;
2875 bool kswapd; /* allocation in kswapd context */
2876 struct completion *done;
2877 struct work_struct work;
2881 * Stack switching interfaces for allocation
2883 static void
2884 xfs_btree_split_worker(
2885 struct work_struct *work)
2887 struct xfs_btree_split_args *args = container_of(work,
2888 struct xfs_btree_split_args, work);
2889 unsigned long pflags;
2890 unsigned long new_pflags = PF_MEMALLOC_NOFS;
2893 * we are in a transaction context here, but may also be doing work
2894 * in kswapd context, and hence we may need to inherit that state
2895 * temporarily to ensure that we don't block waiting for memory reclaim
2896 * in any way.
2898 if (args->kswapd)
2899 new_pflags |= PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD;
2901 current_set_flags_nested(&pflags, new_pflags);
2903 args->result = __xfs_btree_split(args->cur, args->level, args->ptrp,
2904 args->key, args->curp, args->stat);
2905 complete(args->done);
2907 current_restore_flags_nested(&pflags, new_pflags);
2911 * BMBT split requests often come in with little stack to work on. Push
2912 * them off to a worker thread so there is lots of stack to use. For the other
2913 * btree types, just call directly to avoid the context switch overhead here.
2915 STATIC int /* error */
2916 xfs_btree_split(
2917 struct xfs_btree_cur *cur,
2918 int level,
2919 union xfs_btree_ptr *ptrp,
2920 union xfs_btree_key *key,
2921 struct xfs_btree_cur **curp,
2922 int *stat) /* success/failure */
2924 struct xfs_btree_split_args args;
2925 DECLARE_COMPLETION_ONSTACK(done);
2927 if (cur->bc_btnum != XFS_BTNUM_BMAP)
2928 return __xfs_btree_split(cur, level, ptrp, key, curp, stat);
2930 args.cur = cur;
2931 args.level = level;
2932 args.ptrp = ptrp;
2933 args.key = key;
2934 args.curp = curp;
2935 args.stat = stat;
2936 args.done = &done;
2937 args.kswapd = current_is_kswapd();
2938 INIT_WORK_ONSTACK(&args.work, xfs_btree_split_worker);
2939 queue_work(xfs_alloc_wq, &args.work);
2940 wait_for_completion(&done);
2941 destroy_work_on_stack(&args.work);
2942 return args.result;
2947 * Copy the old inode root contents into a real block and make the
2948 * broot point to it.
2950 int /* error */
2951 xfs_btree_new_iroot(
2952 struct xfs_btree_cur *cur, /* btree cursor */
2953 int *logflags, /* logging flags for inode */
2954 int *stat) /* return status - 0 fail */
2956 struct xfs_buf *cbp; /* buffer for cblock */
2957 struct xfs_btree_block *block; /* btree block */
2958 struct xfs_btree_block *cblock; /* child btree block */
2959 union xfs_btree_key *ckp; /* child key pointer */
2960 union xfs_btree_ptr *cpp; /* child ptr pointer */
2961 union xfs_btree_key *kp; /* pointer to btree key */
2962 union xfs_btree_ptr *pp; /* pointer to block addr */
2963 union xfs_btree_ptr nptr; /* new block addr */
2964 int level; /* btree level */
2965 int error; /* error return code */
2966 #ifdef DEBUG
2967 int i; /* loop counter */
2968 #endif
2970 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2971 XFS_BTREE_STATS_INC(cur, newroot);
2973 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
2975 level = cur->bc_nlevels - 1;
2977 block = xfs_btree_get_iroot(cur);
2978 pp = xfs_btree_ptr_addr(cur, 1, block);
2980 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2981 error = cur->bc_ops->alloc_block(cur, pp, &nptr, stat);
2982 if (error)
2983 goto error0;
2984 if (*stat == 0) {
2985 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2986 return 0;
2988 XFS_BTREE_STATS_INC(cur, alloc);
2990 /* Copy the root into a real block. */
2991 error = xfs_btree_get_buf_block(cur, &nptr, 0, &cblock, &cbp);
2992 if (error)
2993 goto error0;
2996 * we can't just memcpy() the root in for CRC enabled btree blocks.
2997 * In that case have to also ensure the blkno remains correct
2999 memcpy(cblock, block, xfs_btree_block_len(cur));
3000 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) {
3001 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
3002 cblock->bb_u.l.bb_blkno = cpu_to_be64(cbp->b_bn);
3003 else
3004 cblock->bb_u.s.bb_blkno = cpu_to_be64(cbp->b_bn);
3007 be16_add_cpu(&block->bb_level, 1);
3008 xfs_btree_set_numrecs(block, 1);
3009 cur->bc_nlevels++;
3010 cur->bc_ptrs[level + 1] = 1;
3012 kp = xfs_btree_key_addr(cur, 1, block);
3013 ckp = xfs_btree_key_addr(cur, 1, cblock);
3014 xfs_btree_copy_keys(cur, ckp, kp, xfs_btree_get_numrecs(cblock));
3016 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
3017 #ifdef DEBUG
3018 for (i = 0; i < be16_to_cpu(cblock->bb_numrecs); i++) {
3019 error = xfs_btree_check_ptr(cur, pp, i, level);
3020 if (error)
3021 goto error0;
3023 #endif
3024 xfs_btree_copy_ptrs(cur, cpp, pp, xfs_btree_get_numrecs(cblock));
3026 #ifdef DEBUG
3027 error = xfs_btree_check_ptr(cur, &nptr, 0, level);
3028 if (error)
3029 goto error0;
3030 #endif
3031 xfs_btree_copy_ptrs(cur, pp, &nptr, 1);
3033 xfs_iroot_realloc(cur->bc_private.b.ip,
3034 1 - xfs_btree_get_numrecs(cblock),
3035 cur->bc_private.b.whichfork);
3037 xfs_btree_setbuf(cur, level, cbp);
3040 * Do all this logging at the end so that
3041 * the root is at the right level.
3043 xfs_btree_log_block(cur, cbp, XFS_BB_ALL_BITS);
3044 xfs_btree_log_keys(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
3045 xfs_btree_log_ptrs(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
3047 *logflags |=
3048 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork);
3049 *stat = 1;
3050 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3051 return 0;
3052 error0:
3053 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3054 return error;
3058 * Allocate a new root block, fill it in.
3060 STATIC int /* error */
3061 xfs_btree_new_root(
3062 struct xfs_btree_cur *cur, /* btree cursor */
3063 int *stat) /* success/failure */
3065 struct xfs_btree_block *block; /* one half of the old root block */
3066 struct xfs_buf *bp; /* buffer containing block */
3067 int error; /* error return value */
3068 struct xfs_buf *lbp; /* left buffer pointer */
3069 struct xfs_btree_block *left; /* left btree block */
3070 struct xfs_buf *nbp; /* new (root) buffer */
3071 struct xfs_btree_block *new; /* new (root) btree block */
3072 int nptr; /* new value for key index, 1 or 2 */
3073 struct xfs_buf *rbp; /* right buffer pointer */
3074 struct xfs_btree_block *right; /* right btree block */
3075 union xfs_btree_ptr rptr;
3076 union xfs_btree_ptr lptr;
3078 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3079 XFS_BTREE_STATS_INC(cur, newroot);
3081 /* initialise our start point from the cursor */
3082 cur->bc_ops->init_ptr_from_cur(cur, &rptr);
3084 /* Allocate the new block. If we can't do it, we're toast. Give up. */
3085 error = cur->bc_ops->alloc_block(cur, &rptr, &lptr, stat);
3086 if (error)
3087 goto error0;
3088 if (*stat == 0)
3089 goto out0;
3090 XFS_BTREE_STATS_INC(cur, alloc);
3092 /* Set up the new block. */
3093 error = xfs_btree_get_buf_block(cur, &lptr, 0, &new, &nbp);
3094 if (error)
3095 goto error0;
3097 /* Set the root in the holding structure increasing the level by 1. */
3098 cur->bc_ops->set_root(cur, &lptr, 1);
3101 * At the previous root level there are now two blocks: the old root,
3102 * and the new block generated when it was split. We don't know which
3103 * one the cursor is pointing at, so we set up variables "left" and
3104 * "right" for each case.
3106 block = xfs_btree_get_block(cur, cur->bc_nlevels - 1, &bp);
3108 #ifdef DEBUG
3109 error = xfs_btree_check_block(cur, block, cur->bc_nlevels - 1, bp);
3110 if (error)
3111 goto error0;
3112 #endif
3114 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
3115 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
3116 /* Our block is left, pick up the right block. */
3117 lbp = bp;
3118 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
3119 left = block;
3120 error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
3121 if (error)
3122 goto error0;
3123 bp = rbp;
3124 nptr = 1;
3125 } else {
3126 /* Our block is right, pick up the left block. */
3127 rbp = bp;
3128 xfs_btree_buf_to_ptr(cur, rbp, &rptr);
3129 right = block;
3130 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
3131 error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
3132 if (error)
3133 goto error0;
3134 bp = lbp;
3135 nptr = 2;
3138 /* Fill in the new block's btree header and log it. */
3139 xfs_btree_init_block_cur(cur, nbp, cur->bc_nlevels, 2);
3140 xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS);
3141 ASSERT(!xfs_btree_ptr_is_null(cur, &lptr) &&
3142 !xfs_btree_ptr_is_null(cur, &rptr));
3144 /* Fill in the key data in the new root. */
3145 if (xfs_btree_get_level(left) > 0) {
3147 * Get the keys for the left block's keys and put them directly
3148 * in the parent block. Do the same for the right block.
3150 xfs_btree_get_node_keys(cur, left,
3151 xfs_btree_key_addr(cur, 1, new));
3152 xfs_btree_get_node_keys(cur, right,
3153 xfs_btree_key_addr(cur, 2, new));
3154 } else {
3156 * Get the keys for the left block's records and put them
3157 * directly in the parent block. Do the same for the right
3158 * block.
3160 xfs_btree_get_leaf_keys(cur, left,
3161 xfs_btree_key_addr(cur, 1, new));
3162 xfs_btree_get_leaf_keys(cur, right,
3163 xfs_btree_key_addr(cur, 2, new));
3165 xfs_btree_log_keys(cur, nbp, 1, 2);
3167 /* Fill in the pointer data in the new root. */
3168 xfs_btree_copy_ptrs(cur,
3169 xfs_btree_ptr_addr(cur, 1, new), &lptr, 1);
3170 xfs_btree_copy_ptrs(cur,
3171 xfs_btree_ptr_addr(cur, 2, new), &rptr, 1);
3172 xfs_btree_log_ptrs(cur, nbp, 1, 2);
3174 /* Fix up the cursor. */
3175 xfs_btree_setbuf(cur, cur->bc_nlevels, nbp);
3176 cur->bc_ptrs[cur->bc_nlevels] = nptr;
3177 cur->bc_nlevels++;
3178 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3179 *stat = 1;
3180 return 0;
3181 error0:
3182 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3183 return error;
3184 out0:
3185 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3186 *stat = 0;
3187 return 0;
3190 STATIC int
3191 xfs_btree_make_block_unfull(
3192 struct xfs_btree_cur *cur, /* btree cursor */
3193 int level, /* btree level */
3194 int numrecs,/* # of recs in block */
3195 int *oindex,/* old tree index */
3196 int *index, /* new tree index */
3197 union xfs_btree_ptr *nptr, /* new btree ptr */
3198 struct xfs_btree_cur **ncur, /* new btree cursor */
3199 union xfs_btree_key *key, /* key of new block */
3200 int *stat)
3202 int error = 0;
3204 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
3205 level == cur->bc_nlevels - 1) {
3206 struct xfs_inode *ip = cur->bc_private.b.ip;
3208 if (numrecs < cur->bc_ops->get_dmaxrecs(cur, level)) {
3209 /* A root block that can be made bigger. */
3210 xfs_iroot_realloc(ip, 1, cur->bc_private.b.whichfork);
3211 *stat = 1;
3212 } else {
3213 /* A root block that needs replacing */
3214 int logflags = 0;
3216 error = xfs_btree_new_iroot(cur, &logflags, stat);
3217 if (error || *stat == 0)
3218 return error;
3220 xfs_trans_log_inode(cur->bc_tp, ip, logflags);
3223 return 0;
3226 /* First, try shifting an entry to the right neighbor. */
3227 error = xfs_btree_rshift(cur, level, stat);
3228 if (error || *stat)
3229 return error;
3231 /* Next, try shifting an entry to the left neighbor. */
3232 error = xfs_btree_lshift(cur, level, stat);
3233 if (error)
3234 return error;
3236 if (*stat) {
3237 *oindex = *index = cur->bc_ptrs[level];
3238 return 0;
3242 * Next, try splitting the current block in half.
3244 * If this works we have to re-set our variables because we
3245 * could be in a different block now.
3247 error = xfs_btree_split(cur, level, nptr, key, ncur, stat);
3248 if (error || *stat == 0)
3249 return error;
3252 *index = cur->bc_ptrs[level];
3253 return 0;
3257 * Insert one record/level. Return information to the caller
3258 * allowing the next level up to proceed if necessary.
3260 STATIC int
3261 xfs_btree_insrec(
3262 struct xfs_btree_cur *cur, /* btree cursor */
3263 int level, /* level to insert record at */
3264 union xfs_btree_ptr *ptrp, /* i/o: block number inserted */
3265 union xfs_btree_rec *rec, /* record to insert */
3266 union xfs_btree_key *key, /* i/o: block key for ptrp */
3267 struct xfs_btree_cur **curp, /* output: new cursor replacing cur */
3268 int *stat) /* success/failure */
3270 struct xfs_btree_block *block; /* btree block */
3271 struct xfs_buf *bp; /* buffer for block */
3272 union xfs_btree_ptr nptr; /* new block ptr */
3273 struct xfs_btree_cur *ncur; /* new btree cursor */
3274 union xfs_btree_key nkey; /* new block key */
3275 union xfs_btree_key *lkey;
3276 int optr; /* old key/record index */
3277 int ptr; /* key/record index */
3278 int numrecs;/* number of records */
3279 int error; /* error return value */
3280 #ifdef DEBUG
3281 int i;
3282 #endif
3283 xfs_daddr_t old_bn;
3285 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3286 XFS_BTREE_TRACE_ARGIPR(cur, level, *ptrp, &rec);
3288 ncur = NULL;
3289 lkey = &nkey;
3292 * If we have an external root pointer, and we've made it to the
3293 * root level, allocate a new root block and we're done.
3295 if (!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
3296 (level >= cur->bc_nlevels)) {
3297 error = xfs_btree_new_root(cur, stat);
3298 xfs_btree_set_ptr_null(cur, ptrp);
3300 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3301 return error;
3304 /* If we're off the left edge, return failure. */
3305 ptr = cur->bc_ptrs[level];
3306 if (ptr == 0) {
3307 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3308 *stat = 0;
3309 return 0;
3312 optr = ptr;
3314 XFS_BTREE_STATS_INC(cur, insrec);
3316 /* Get pointers to the btree buffer and block. */
3317 block = xfs_btree_get_block(cur, level, &bp);
3318 old_bn = bp ? bp->b_bn : XFS_BUF_DADDR_NULL;
3319 numrecs = xfs_btree_get_numrecs(block);
3321 #ifdef DEBUG
3322 error = xfs_btree_check_block(cur, block, level, bp);
3323 if (error)
3324 goto error0;
3326 /* Check that the new entry is being inserted in the right place. */
3327 if (ptr <= numrecs) {
3328 if (level == 0) {
3329 ASSERT(cur->bc_ops->recs_inorder(cur, rec,
3330 xfs_btree_rec_addr(cur, ptr, block)));
3331 } else {
3332 ASSERT(cur->bc_ops->keys_inorder(cur, key,
3333 xfs_btree_key_addr(cur, ptr, block)));
3336 #endif
3339 * If the block is full, we can't insert the new entry until we
3340 * make the block un-full.
3342 xfs_btree_set_ptr_null(cur, &nptr);
3343 if (numrecs == cur->bc_ops->get_maxrecs(cur, level)) {
3344 error = xfs_btree_make_block_unfull(cur, level, numrecs,
3345 &optr, &ptr, &nptr, &ncur, lkey, stat);
3346 if (error || *stat == 0)
3347 goto error0;
3351 * The current block may have changed if the block was
3352 * previously full and we have just made space in it.
3354 block = xfs_btree_get_block(cur, level, &bp);
3355 numrecs = xfs_btree_get_numrecs(block);
3357 #ifdef DEBUG
3358 error = xfs_btree_check_block(cur, block, level, bp);
3359 if (error)
3360 return error;
3361 #endif
3364 * At this point we know there's room for our new entry in the block
3365 * we're pointing at.
3367 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr + 1);
3369 if (level > 0) {
3370 /* It's a nonleaf. make a hole in the keys and ptrs */
3371 union xfs_btree_key *kp;
3372 union xfs_btree_ptr *pp;
3374 kp = xfs_btree_key_addr(cur, ptr, block);
3375 pp = xfs_btree_ptr_addr(cur, ptr, block);
3377 #ifdef DEBUG
3378 for (i = numrecs - ptr; i >= 0; i--) {
3379 error = xfs_btree_check_ptr(cur, pp, i, level);
3380 if (error)
3381 return error;
3383 #endif
3385 xfs_btree_shift_keys(cur, kp, 1, numrecs - ptr + 1);
3386 xfs_btree_shift_ptrs(cur, pp, 1, numrecs - ptr + 1);
3388 #ifdef DEBUG
3389 error = xfs_btree_check_ptr(cur, ptrp, 0, level);
3390 if (error)
3391 goto error0;
3392 #endif
3394 /* Now put the new data in, bump numrecs and log it. */
3395 xfs_btree_copy_keys(cur, kp, key, 1);
3396 xfs_btree_copy_ptrs(cur, pp, ptrp, 1);
3397 numrecs++;
3398 xfs_btree_set_numrecs(block, numrecs);
3399 xfs_btree_log_ptrs(cur, bp, ptr, numrecs);
3400 xfs_btree_log_keys(cur, bp, ptr, numrecs);
3401 #ifdef DEBUG
3402 if (ptr < numrecs) {
3403 ASSERT(cur->bc_ops->keys_inorder(cur, kp,
3404 xfs_btree_key_addr(cur, ptr + 1, block)));
3406 #endif
3407 } else {
3408 /* It's a leaf. make a hole in the records */
3409 union xfs_btree_rec *rp;
3411 rp = xfs_btree_rec_addr(cur, ptr, block);
3413 xfs_btree_shift_recs(cur, rp, 1, numrecs - ptr + 1);
3415 /* Now put the new data in, bump numrecs and log it. */
3416 xfs_btree_copy_recs(cur, rp, rec, 1);
3417 xfs_btree_set_numrecs(block, ++numrecs);
3418 xfs_btree_log_recs(cur, bp, ptr, numrecs);
3419 #ifdef DEBUG
3420 if (ptr < numrecs) {
3421 ASSERT(cur->bc_ops->recs_inorder(cur, rp,
3422 xfs_btree_rec_addr(cur, ptr + 1, block)));
3424 #endif
3427 /* Log the new number of records in the btree header. */
3428 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
3431 * If we just inserted into a new tree block, we have to
3432 * recalculate nkey here because nkey is out of date.
3434 * Otherwise we're just updating an existing block (having shoved
3435 * some records into the new tree block), so use the regular key
3436 * update mechanism.
3438 if (bp && bp->b_bn != old_bn) {
3439 xfs_btree_get_keys(cur, block, lkey);
3440 } else if (xfs_btree_needs_key_update(cur, optr)) {
3441 error = xfs_btree_update_keys(cur, level);
3442 if (error)
3443 goto error0;
3447 * If we are tracking the last record in the tree and
3448 * we are at the far right edge of the tree, update it.
3450 if (xfs_btree_is_lastrec(cur, block, level)) {
3451 cur->bc_ops->update_lastrec(cur, block, rec,
3452 ptr, LASTREC_INSREC);
3456 * Return the new block number, if any.
3457 * If there is one, give back a record value and a cursor too.
3459 *ptrp = nptr;
3460 if (!xfs_btree_ptr_is_null(cur, &nptr)) {
3461 xfs_btree_copy_keys(cur, key, lkey, 1);
3462 *curp = ncur;
3465 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3466 *stat = 1;
3467 return 0;
3469 error0:
3470 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3471 return error;
3475 * Insert the record at the point referenced by cur.
3477 * A multi-level split of the tree on insert will invalidate the original
3478 * cursor. All callers of this function should assume that the cursor is
3479 * no longer valid and revalidate it.
3482 xfs_btree_insert(
3483 struct xfs_btree_cur *cur,
3484 int *stat)
3486 int error; /* error return value */
3487 int i; /* result value, 0 for failure */
3488 int level; /* current level number in btree */
3489 union xfs_btree_ptr nptr; /* new block number (split result) */
3490 struct xfs_btree_cur *ncur; /* new cursor (split result) */
3491 struct xfs_btree_cur *pcur; /* previous level's cursor */
3492 union xfs_btree_key bkey; /* key of block to insert */
3493 union xfs_btree_key *key;
3494 union xfs_btree_rec rec; /* record to insert */
3496 level = 0;
3497 ncur = NULL;
3498 pcur = cur;
3499 key = &bkey;
3501 xfs_btree_set_ptr_null(cur, &nptr);
3503 /* Make a key out of the record data to be inserted, and save it. */
3504 cur->bc_ops->init_rec_from_cur(cur, &rec);
3505 cur->bc_ops->init_key_from_rec(key, &rec);
3508 * Loop going up the tree, starting at the leaf level.
3509 * Stop when we don't get a split block, that must mean that
3510 * the insert is finished with this level.
3512 do {
3514 * Insert nrec/nptr into this level of the tree.
3515 * Note if we fail, nptr will be null.
3517 error = xfs_btree_insrec(pcur, level, &nptr, &rec, key,
3518 &ncur, &i);
3519 if (error) {
3520 if (pcur != cur)
3521 xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR);
3522 goto error0;
3525 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
3526 level++;
3529 * See if the cursor we just used is trash.
3530 * Can't trash the caller's cursor, but otherwise we should
3531 * if ncur is a new cursor or we're about to be done.
3533 if (pcur != cur &&
3534 (ncur || xfs_btree_ptr_is_null(cur, &nptr))) {
3535 /* Save the state from the cursor before we trash it */
3536 if (cur->bc_ops->update_cursor)
3537 cur->bc_ops->update_cursor(pcur, cur);
3538 cur->bc_nlevels = pcur->bc_nlevels;
3539 xfs_btree_del_cursor(pcur, XFS_BTREE_NOERROR);
3541 /* If we got a new cursor, switch to it. */
3542 if (ncur) {
3543 pcur = ncur;
3544 ncur = NULL;
3546 } while (!xfs_btree_ptr_is_null(cur, &nptr));
3548 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3549 *stat = i;
3550 return 0;
3551 error0:
3552 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3553 return error;
3557 * Try to merge a non-leaf block back into the inode root.
3559 * Note: the killroot names comes from the fact that we're effectively
3560 * killing the old root block. But because we can't just delete the
3561 * inode we have to copy the single block it was pointing to into the
3562 * inode.
3564 STATIC int
3565 xfs_btree_kill_iroot(
3566 struct xfs_btree_cur *cur)
3568 int whichfork = cur->bc_private.b.whichfork;
3569 struct xfs_inode *ip = cur->bc_private.b.ip;
3570 struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork);
3571 struct xfs_btree_block *block;
3572 struct xfs_btree_block *cblock;
3573 union xfs_btree_key *kp;
3574 union xfs_btree_key *ckp;
3575 union xfs_btree_ptr *pp;
3576 union xfs_btree_ptr *cpp;
3577 struct xfs_buf *cbp;
3578 int level;
3579 int index;
3580 int numrecs;
3581 int error;
3582 #ifdef DEBUG
3583 union xfs_btree_ptr ptr;
3584 int i;
3585 #endif
3587 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3589 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
3590 ASSERT(cur->bc_nlevels > 1);
3593 * Don't deal with the root block needs to be a leaf case.
3594 * We're just going to turn the thing back into extents anyway.
3596 level = cur->bc_nlevels - 1;
3597 if (level == 1)
3598 goto out0;
3601 * Give up if the root has multiple children.
3603 block = xfs_btree_get_iroot(cur);
3604 if (xfs_btree_get_numrecs(block) != 1)
3605 goto out0;
3607 cblock = xfs_btree_get_block(cur, level - 1, &cbp);
3608 numrecs = xfs_btree_get_numrecs(cblock);
3611 * Only do this if the next level will fit.
3612 * Then the data must be copied up to the inode,
3613 * instead of freeing the root you free the next level.
3615 if (numrecs > cur->bc_ops->get_dmaxrecs(cur, level))
3616 goto out0;
3618 XFS_BTREE_STATS_INC(cur, killroot);
3620 #ifdef DEBUG
3621 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
3622 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
3623 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
3624 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
3625 #endif
3627 index = numrecs - cur->bc_ops->get_maxrecs(cur, level);
3628 if (index) {
3629 xfs_iroot_realloc(cur->bc_private.b.ip, index,
3630 cur->bc_private.b.whichfork);
3631 block = ifp->if_broot;
3634 be16_add_cpu(&block->bb_numrecs, index);
3635 ASSERT(block->bb_numrecs == cblock->bb_numrecs);
3637 kp = xfs_btree_key_addr(cur, 1, block);
3638 ckp = xfs_btree_key_addr(cur, 1, cblock);
3639 xfs_btree_copy_keys(cur, kp, ckp, numrecs);
3641 pp = xfs_btree_ptr_addr(cur, 1, block);
3642 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
3643 #ifdef DEBUG
3644 for (i = 0; i < numrecs; i++) {
3645 error = xfs_btree_check_ptr(cur, cpp, i, level - 1);
3646 if (error) {
3647 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3648 return error;
3651 #endif
3652 xfs_btree_copy_ptrs(cur, pp, cpp, numrecs);
3654 error = xfs_btree_free_block(cur, cbp);
3655 if (error) {
3656 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3657 return error;
3660 cur->bc_bufs[level - 1] = NULL;
3661 be16_add_cpu(&block->bb_level, -1);
3662 xfs_trans_log_inode(cur->bc_tp, ip,
3663 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork));
3664 cur->bc_nlevels--;
3665 out0:
3666 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3667 return 0;
3671 * Kill the current root node, and replace it with it's only child node.
3673 STATIC int
3674 xfs_btree_kill_root(
3675 struct xfs_btree_cur *cur,
3676 struct xfs_buf *bp,
3677 int level,
3678 union xfs_btree_ptr *newroot)
3680 int error;
3682 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3683 XFS_BTREE_STATS_INC(cur, killroot);
3686 * Update the root pointer, decreasing the level by 1 and then
3687 * free the old root.
3689 cur->bc_ops->set_root(cur, newroot, -1);
3691 error = xfs_btree_free_block(cur, bp);
3692 if (error) {
3693 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3694 return error;
3697 cur->bc_bufs[level] = NULL;
3698 cur->bc_ra[level] = 0;
3699 cur->bc_nlevels--;
3701 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3702 return 0;
3705 STATIC int
3706 xfs_btree_dec_cursor(
3707 struct xfs_btree_cur *cur,
3708 int level,
3709 int *stat)
3711 int error;
3712 int i;
3714 if (level > 0) {
3715 error = xfs_btree_decrement(cur, level, &i);
3716 if (error)
3717 return error;
3720 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3721 *stat = 1;
3722 return 0;
3726 * Single level of the btree record deletion routine.
3727 * Delete record pointed to by cur/level.
3728 * Remove the record from its block then rebalance the tree.
3729 * Return 0 for error, 1 for done, 2 to go on to the next level.
3731 STATIC int /* error */
3732 xfs_btree_delrec(
3733 struct xfs_btree_cur *cur, /* btree cursor */
3734 int level, /* level removing record from */
3735 int *stat) /* fail/done/go-on */
3737 struct xfs_btree_block *block; /* btree block */
3738 union xfs_btree_ptr cptr; /* current block ptr */
3739 struct xfs_buf *bp; /* buffer for block */
3740 int error; /* error return value */
3741 int i; /* loop counter */
3742 union xfs_btree_ptr lptr; /* left sibling block ptr */
3743 struct xfs_buf *lbp; /* left buffer pointer */
3744 struct xfs_btree_block *left; /* left btree block */
3745 int lrecs = 0; /* left record count */
3746 int ptr; /* key/record index */
3747 union xfs_btree_ptr rptr; /* right sibling block ptr */
3748 struct xfs_buf *rbp; /* right buffer pointer */
3749 struct xfs_btree_block *right; /* right btree block */
3750 struct xfs_btree_block *rrblock; /* right-right btree block */
3751 struct xfs_buf *rrbp; /* right-right buffer pointer */
3752 int rrecs = 0; /* right record count */
3753 struct xfs_btree_cur *tcur; /* temporary btree cursor */
3754 int numrecs; /* temporary numrec count */
3756 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3757 XFS_BTREE_TRACE_ARGI(cur, level);
3759 tcur = NULL;
3761 /* Get the index of the entry being deleted, check for nothing there. */
3762 ptr = cur->bc_ptrs[level];
3763 if (ptr == 0) {
3764 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3765 *stat = 0;
3766 return 0;
3769 /* Get the buffer & block containing the record or key/ptr. */
3770 block = xfs_btree_get_block(cur, level, &bp);
3771 numrecs = xfs_btree_get_numrecs(block);
3773 #ifdef DEBUG
3774 error = xfs_btree_check_block(cur, block, level, bp);
3775 if (error)
3776 goto error0;
3777 #endif
3779 /* Fail if we're off the end of the block. */
3780 if (ptr > numrecs) {
3781 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3782 *stat = 0;
3783 return 0;
3786 XFS_BTREE_STATS_INC(cur, delrec);
3787 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr);
3789 /* Excise the entries being deleted. */
3790 if (level > 0) {
3791 /* It's a nonleaf. operate on keys and ptrs */
3792 union xfs_btree_key *lkp;
3793 union xfs_btree_ptr *lpp;
3795 lkp = xfs_btree_key_addr(cur, ptr + 1, block);
3796 lpp = xfs_btree_ptr_addr(cur, ptr + 1, block);
3798 #ifdef DEBUG
3799 for (i = 0; i < numrecs - ptr; i++) {
3800 error = xfs_btree_check_ptr(cur, lpp, i, level);
3801 if (error)
3802 goto error0;
3804 #endif
3806 if (ptr < numrecs) {
3807 xfs_btree_shift_keys(cur, lkp, -1, numrecs - ptr);
3808 xfs_btree_shift_ptrs(cur, lpp, -1, numrecs - ptr);
3809 xfs_btree_log_keys(cur, bp, ptr, numrecs - 1);
3810 xfs_btree_log_ptrs(cur, bp, ptr, numrecs - 1);
3812 } else {
3813 /* It's a leaf. operate on records */
3814 if (ptr < numrecs) {
3815 xfs_btree_shift_recs(cur,
3816 xfs_btree_rec_addr(cur, ptr + 1, block),
3817 -1, numrecs - ptr);
3818 xfs_btree_log_recs(cur, bp, ptr, numrecs - 1);
3823 * Decrement and log the number of entries in the block.
3825 xfs_btree_set_numrecs(block, --numrecs);
3826 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
3829 * If we are tracking the last record in the tree and
3830 * we are at the far right edge of the tree, update it.
3832 if (xfs_btree_is_lastrec(cur, block, level)) {
3833 cur->bc_ops->update_lastrec(cur, block, NULL,
3834 ptr, LASTREC_DELREC);
3838 * We're at the root level. First, shrink the root block in-memory.
3839 * Try to get rid of the next level down. If we can't then there's
3840 * nothing left to do.
3842 if (level == cur->bc_nlevels - 1) {
3843 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3844 xfs_iroot_realloc(cur->bc_private.b.ip, -1,
3845 cur->bc_private.b.whichfork);
3847 error = xfs_btree_kill_iroot(cur);
3848 if (error)
3849 goto error0;
3851 error = xfs_btree_dec_cursor(cur, level, stat);
3852 if (error)
3853 goto error0;
3854 *stat = 1;
3855 return 0;
3859 * If this is the root level, and there's only one entry left,
3860 * and it's NOT the leaf level, then we can get rid of this
3861 * level.
3863 if (numrecs == 1 && level > 0) {
3864 union xfs_btree_ptr *pp;
3866 * pp is still set to the first pointer in the block.
3867 * Make it the new root of the btree.
3869 pp = xfs_btree_ptr_addr(cur, 1, block);
3870 error = xfs_btree_kill_root(cur, bp, level, pp);
3871 if (error)
3872 goto error0;
3873 } else if (level > 0) {
3874 error = xfs_btree_dec_cursor(cur, level, stat);
3875 if (error)
3876 goto error0;
3878 *stat = 1;
3879 return 0;
3883 * If we deleted the leftmost entry in the block, update the
3884 * key values above us in the tree.
3886 if (xfs_btree_needs_key_update(cur, ptr)) {
3887 error = xfs_btree_update_keys(cur, level);
3888 if (error)
3889 goto error0;
3893 * If the number of records remaining in the block is at least
3894 * the minimum, we're done.
3896 if (numrecs >= cur->bc_ops->get_minrecs(cur, level)) {
3897 error = xfs_btree_dec_cursor(cur, level, stat);
3898 if (error)
3899 goto error0;
3900 return 0;
3904 * Otherwise, we have to move some records around to keep the
3905 * tree balanced. Look at the left and right sibling blocks to
3906 * see if we can re-balance by moving only one record.
3908 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
3909 xfs_btree_get_sibling(cur, block, &lptr, XFS_BB_LEFTSIB);
3911 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3913 * One child of root, need to get a chance to copy its contents
3914 * into the root and delete it. Can't go up to next level,
3915 * there's nothing to delete there.
3917 if (xfs_btree_ptr_is_null(cur, &rptr) &&
3918 xfs_btree_ptr_is_null(cur, &lptr) &&
3919 level == cur->bc_nlevels - 2) {
3920 error = xfs_btree_kill_iroot(cur);
3921 if (!error)
3922 error = xfs_btree_dec_cursor(cur, level, stat);
3923 if (error)
3924 goto error0;
3925 return 0;
3929 ASSERT(!xfs_btree_ptr_is_null(cur, &rptr) ||
3930 !xfs_btree_ptr_is_null(cur, &lptr));
3933 * Duplicate the cursor so our btree manipulations here won't
3934 * disrupt the next level up.
3936 error = xfs_btree_dup_cursor(cur, &tcur);
3937 if (error)
3938 goto error0;
3941 * If there's a right sibling, see if it's ok to shift an entry
3942 * out of it.
3944 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
3946 * Move the temp cursor to the last entry in the next block.
3947 * Actually any entry but the first would suffice.
3949 i = xfs_btree_lastrec(tcur, level);
3950 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
3952 error = xfs_btree_increment(tcur, level, &i);
3953 if (error)
3954 goto error0;
3955 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
3957 i = xfs_btree_lastrec(tcur, level);
3958 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
3960 /* Grab a pointer to the block. */
3961 right = xfs_btree_get_block(tcur, level, &rbp);
3962 #ifdef DEBUG
3963 error = xfs_btree_check_block(tcur, right, level, rbp);
3964 if (error)
3965 goto error0;
3966 #endif
3967 /* Grab the current block number, for future use. */
3968 xfs_btree_get_sibling(tcur, right, &cptr, XFS_BB_LEFTSIB);
3971 * If right block is full enough so that removing one entry
3972 * won't make it too empty, and left-shifting an entry out
3973 * of right to us works, we're done.
3975 if (xfs_btree_get_numrecs(right) - 1 >=
3976 cur->bc_ops->get_minrecs(tcur, level)) {
3977 error = xfs_btree_lshift(tcur, level, &i);
3978 if (error)
3979 goto error0;
3980 if (i) {
3981 ASSERT(xfs_btree_get_numrecs(block) >=
3982 cur->bc_ops->get_minrecs(tcur, level));
3984 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3985 tcur = NULL;
3987 error = xfs_btree_dec_cursor(cur, level, stat);
3988 if (error)
3989 goto error0;
3990 return 0;
3995 * Otherwise, grab the number of records in right for
3996 * future reference, and fix up the temp cursor to point
3997 * to our block again (last record).
3999 rrecs = xfs_btree_get_numrecs(right);
4000 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
4001 i = xfs_btree_firstrec(tcur, level);
4002 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
4004 error = xfs_btree_decrement(tcur, level, &i);
4005 if (error)
4006 goto error0;
4007 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
4012 * If there's a left sibling, see if it's ok to shift an entry
4013 * out of it.
4015 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
4017 * Move the temp cursor to the first entry in the
4018 * previous block.
4020 i = xfs_btree_firstrec(tcur, level);
4021 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
4023 error = xfs_btree_decrement(tcur, level, &i);
4024 if (error)
4025 goto error0;
4026 i = xfs_btree_firstrec(tcur, level);
4027 XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
4029 /* Grab a pointer to the block. */
4030 left = xfs_btree_get_block(tcur, level, &lbp);
4031 #ifdef DEBUG
4032 error = xfs_btree_check_block(cur, left, level, lbp);
4033 if (error)
4034 goto error0;
4035 #endif
4036 /* Grab the current block number, for future use. */
4037 xfs_btree_get_sibling(tcur, left, &cptr, XFS_BB_RIGHTSIB);
4040 * If left block is full enough so that removing one entry
4041 * won't make it too empty, and right-shifting an entry out
4042 * of left to us works, we're done.
4044 if (xfs_btree_get_numrecs(left) - 1 >=
4045 cur->bc_ops->get_minrecs(tcur, level)) {
4046 error = xfs_btree_rshift(tcur, level, &i);
4047 if (error)
4048 goto error0;
4049 if (i) {
4050 ASSERT(xfs_btree_get_numrecs(block) >=
4051 cur->bc_ops->get_minrecs(tcur, level));
4052 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
4053 tcur = NULL;
4054 if (level == 0)
4055 cur->bc_ptrs[0]++;
4056 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
4057 *stat = 1;
4058 return 0;
4063 * Otherwise, grab the number of records in right for
4064 * future reference.
4066 lrecs = xfs_btree_get_numrecs(left);
4069 /* Delete the temp cursor, we're done with it. */
4070 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
4071 tcur = NULL;
4073 /* If here, we need to do a join to keep the tree balanced. */
4074 ASSERT(!xfs_btree_ptr_is_null(cur, &cptr));
4076 if (!xfs_btree_ptr_is_null(cur, &lptr) &&
4077 lrecs + xfs_btree_get_numrecs(block) <=
4078 cur->bc_ops->get_maxrecs(cur, level)) {
4080 * Set "right" to be the starting block,
4081 * "left" to be the left neighbor.
4083 rptr = cptr;
4084 right = block;
4085 rbp = bp;
4086 error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
4087 if (error)
4088 goto error0;
4091 * If that won't work, see if we can join with the right neighbor block.
4093 } else if (!xfs_btree_ptr_is_null(cur, &rptr) &&
4094 rrecs + xfs_btree_get_numrecs(block) <=
4095 cur->bc_ops->get_maxrecs(cur, level)) {
4097 * Set "left" to be the starting block,
4098 * "right" to be the right neighbor.
4100 lptr = cptr;
4101 left = block;
4102 lbp = bp;
4103 error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
4104 if (error)
4105 goto error0;
4108 * Otherwise, we can't fix the imbalance.
4109 * Just return. This is probably a logic error, but it's not fatal.
4111 } else {
4112 error = xfs_btree_dec_cursor(cur, level, stat);
4113 if (error)
4114 goto error0;
4115 return 0;
4118 rrecs = xfs_btree_get_numrecs(right);
4119 lrecs = xfs_btree_get_numrecs(left);
4122 * We're now going to join "left" and "right" by moving all the stuff
4123 * in "right" to "left" and deleting "right".
4125 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
4126 if (level > 0) {
4127 /* It's a non-leaf. Move keys and pointers. */
4128 union xfs_btree_key *lkp; /* left btree key */
4129 union xfs_btree_ptr *lpp; /* left address pointer */
4130 union xfs_btree_key *rkp; /* right btree key */
4131 union xfs_btree_ptr *rpp; /* right address pointer */
4133 lkp = xfs_btree_key_addr(cur, lrecs + 1, left);
4134 lpp = xfs_btree_ptr_addr(cur, lrecs + 1, left);
4135 rkp = xfs_btree_key_addr(cur, 1, right);
4136 rpp = xfs_btree_ptr_addr(cur, 1, right);
4137 #ifdef DEBUG
4138 for (i = 1; i < rrecs; i++) {
4139 error = xfs_btree_check_ptr(cur, rpp, i, level);
4140 if (error)
4141 goto error0;
4143 #endif
4144 xfs_btree_copy_keys(cur, lkp, rkp, rrecs);
4145 xfs_btree_copy_ptrs(cur, lpp, rpp, rrecs);
4147 xfs_btree_log_keys(cur, lbp, lrecs + 1, lrecs + rrecs);
4148 xfs_btree_log_ptrs(cur, lbp, lrecs + 1, lrecs + rrecs);
4149 } else {
4150 /* It's a leaf. Move records. */
4151 union xfs_btree_rec *lrp; /* left record pointer */
4152 union xfs_btree_rec *rrp; /* right record pointer */
4154 lrp = xfs_btree_rec_addr(cur, lrecs + 1, left);
4155 rrp = xfs_btree_rec_addr(cur, 1, right);
4157 xfs_btree_copy_recs(cur, lrp, rrp, rrecs);
4158 xfs_btree_log_recs(cur, lbp, lrecs + 1, lrecs + rrecs);
4161 XFS_BTREE_STATS_INC(cur, join);
4164 * Fix up the number of records and right block pointer in the
4165 * surviving block, and log it.
4167 xfs_btree_set_numrecs(left, lrecs + rrecs);
4168 xfs_btree_get_sibling(cur, right, &cptr, XFS_BB_RIGHTSIB),
4169 xfs_btree_set_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
4170 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
4172 /* If there is a right sibling, point it to the remaining block. */
4173 xfs_btree_get_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
4174 if (!xfs_btree_ptr_is_null(cur, &cptr)) {
4175 error = xfs_btree_read_buf_block(cur, &cptr, 0, &rrblock, &rrbp);
4176 if (error)
4177 goto error0;
4178 xfs_btree_set_sibling(cur, rrblock, &lptr, XFS_BB_LEFTSIB);
4179 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
4182 /* Free the deleted block. */
4183 error = xfs_btree_free_block(cur, rbp);
4184 if (error)
4185 goto error0;
4188 * If we joined with the left neighbor, set the buffer in the
4189 * cursor to the left block, and fix up the index.
4191 if (bp != lbp) {
4192 cur->bc_bufs[level] = lbp;
4193 cur->bc_ptrs[level] += lrecs;
4194 cur->bc_ra[level] = 0;
4197 * If we joined with the right neighbor and there's a level above
4198 * us, increment the cursor at that level.
4200 else if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) ||
4201 (level + 1 < cur->bc_nlevels)) {
4202 error = xfs_btree_increment(cur, level + 1, &i);
4203 if (error)
4204 goto error0;
4208 * Readjust the ptr at this level if it's not a leaf, since it's
4209 * still pointing at the deletion point, which makes the cursor
4210 * inconsistent. If this makes the ptr 0, the caller fixes it up.
4211 * We can't use decrement because it would change the next level up.
4213 if (level > 0)
4214 cur->bc_ptrs[level]--;
4217 * We combined blocks, so we have to update the parent keys if the
4218 * btree supports overlapped intervals. However, bc_ptrs[level + 1]
4219 * points to the old block so that the caller knows which record to
4220 * delete. Therefore, the caller must be savvy enough to call updkeys
4221 * for us if we return stat == 2. The other exit points from this
4222 * function don't require deletions further up the tree, so they can
4223 * call updkeys directly.
4226 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
4227 /* Return value means the next level up has something to do. */
4228 *stat = 2;
4229 return 0;
4231 error0:
4232 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
4233 if (tcur)
4234 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
4235 return error;
4239 * Delete the record pointed to by cur.
4240 * The cursor refers to the place where the record was (could be inserted)
4241 * when the operation returns.
4243 int /* error */
4244 xfs_btree_delete(
4245 struct xfs_btree_cur *cur,
4246 int *stat) /* success/failure */
4248 int error; /* error return value */
4249 int level;
4250 int i;
4251 bool joined = false;
4253 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
4256 * Go up the tree, starting at leaf level.
4258 * If 2 is returned then a join was done; go to the next level.
4259 * Otherwise we are done.
4261 for (level = 0, i = 2; i == 2; level++) {
4262 error = xfs_btree_delrec(cur, level, &i);
4263 if (error)
4264 goto error0;
4265 if (i == 2)
4266 joined = true;
4270 * If we combined blocks as part of deleting the record, delrec won't
4271 * have updated the parent high keys so we have to do that here.
4273 if (joined && (cur->bc_flags & XFS_BTREE_OVERLAPPING)) {
4274 error = xfs_btree_updkeys_force(cur, 0);
4275 if (error)
4276 goto error0;
4279 if (i == 0) {
4280 for (level = 1; level < cur->bc_nlevels; level++) {
4281 if (cur->bc_ptrs[level] == 0) {
4282 error = xfs_btree_decrement(cur, level, &i);
4283 if (error)
4284 goto error0;
4285 break;
4290 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
4291 *stat = i;
4292 return 0;
4293 error0:
4294 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
4295 return error;
4299 * Get the data from the pointed-to record.
4301 int /* error */
4302 xfs_btree_get_rec(
4303 struct xfs_btree_cur *cur, /* btree cursor */
4304 union xfs_btree_rec **recp, /* output: btree record */
4305 int *stat) /* output: success/failure */
4307 struct xfs_btree_block *block; /* btree block */
4308 struct xfs_buf *bp; /* buffer pointer */
4309 int ptr; /* record number */
4310 #ifdef DEBUG
4311 int error; /* error return value */
4312 #endif
4314 ptr = cur->bc_ptrs[0];
4315 block = xfs_btree_get_block(cur, 0, &bp);
4317 #ifdef DEBUG
4318 error = xfs_btree_check_block(cur, block, 0, bp);
4319 if (error)
4320 return error;
4321 #endif
4324 * Off the right end or left end, return failure.
4326 if (ptr > xfs_btree_get_numrecs(block) || ptr <= 0) {
4327 *stat = 0;
4328 return 0;
4332 * Point to the record and extract its data.
4334 *recp = xfs_btree_rec_addr(cur, ptr, block);
4335 *stat = 1;
4336 return 0;
4339 /* Visit a block in a btree. */
4340 STATIC int
4341 xfs_btree_visit_block(
4342 struct xfs_btree_cur *cur,
4343 int level,
4344 xfs_btree_visit_blocks_fn fn,
4345 void *data)
4347 struct xfs_btree_block *block;
4348 struct xfs_buf *bp;
4349 union xfs_btree_ptr rptr;
4350 int error;
4352 /* do right sibling readahead */
4353 xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
4354 block = xfs_btree_get_block(cur, level, &bp);
4356 /* process the block */
4357 error = fn(cur, level, data);
4358 if (error)
4359 return error;
4361 /* now read rh sibling block for next iteration */
4362 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
4363 if (xfs_btree_ptr_is_null(cur, &rptr))
4364 return -ENOENT;
4366 return xfs_btree_lookup_get_block(cur, level, &rptr, &block);
4370 /* Visit every block in a btree. */
4372 xfs_btree_visit_blocks(
4373 struct xfs_btree_cur *cur,
4374 xfs_btree_visit_blocks_fn fn,
4375 void *data)
4377 union xfs_btree_ptr lptr;
4378 int level;
4379 struct xfs_btree_block *block = NULL;
4380 int error = 0;
4382 cur->bc_ops->init_ptr_from_cur(cur, &lptr);
4384 /* for each level */
4385 for (level = cur->bc_nlevels - 1; level >= 0; level--) {
4386 /* grab the left hand block */
4387 error = xfs_btree_lookup_get_block(cur, level, &lptr, &block);
4388 if (error)
4389 return error;
4391 /* readahead the left most block for the next level down */
4392 if (level > 0) {
4393 union xfs_btree_ptr *ptr;
4395 ptr = xfs_btree_ptr_addr(cur, 1, block);
4396 xfs_btree_readahead_ptr(cur, ptr, 1);
4398 /* save for the next iteration of the loop */
4399 xfs_btree_copy_ptrs(cur, &lptr, ptr, 1);
4402 /* for each buffer in the level */
4403 do {
4404 error = xfs_btree_visit_block(cur, level, fn, data);
4405 } while (!error);
4407 if (error != -ENOENT)
4408 return error;
4411 return 0;
4415 * Change the owner of a btree.
4417 * The mechanism we use here is ordered buffer logging. Because we don't know
4418 * how many buffers were are going to need to modify, we don't really want to
4419 * have to make transaction reservations for the worst case of every buffer in a
4420 * full size btree as that may be more space that we can fit in the log....
4422 * We do the btree walk in the most optimal manner possible - we have sibling
4423 * pointers so we can just walk all the blocks on each level from left to right
4424 * in a single pass, and then move to the next level and do the same. We can
4425 * also do readahead on the sibling pointers to get IO moving more quickly,
4426 * though for slow disks this is unlikely to make much difference to performance
4427 * as the amount of CPU work we have to do before moving to the next block is
4428 * relatively small.
4430 * For each btree block that we load, modify the owner appropriately, set the
4431 * buffer as an ordered buffer and log it appropriately. We need to ensure that
4432 * we mark the region we change dirty so that if the buffer is relogged in
4433 * a subsequent transaction the changes we make here as an ordered buffer are
4434 * correctly relogged in that transaction. If we are in recovery context, then
4435 * just queue the modified buffer as delayed write buffer so the transaction
4436 * recovery completion writes the changes to disk.
4438 struct xfs_btree_block_change_owner_info {
4439 uint64_t new_owner;
4440 struct list_head *buffer_list;
4443 static int
4444 xfs_btree_block_change_owner(
4445 struct xfs_btree_cur *cur,
4446 int level,
4447 void *data)
4449 struct xfs_btree_block_change_owner_info *bbcoi = data;
4450 struct xfs_btree_block *block;
4451 struct xfs_buf *bp;
4453 /* modify the owner */
4454 block = xfs_btree_get_block(cur, level, &bp);
4455 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
4456 if (block->bb_u.l.bb_owner == cpu_to_be64(bbcoi->new_owner))
4457 return 0;
4458 block->bb_u.l.bb_owner = cpu_to_be64(bbcoi->new_owner);
4459 } else {
4460 if (block->bb_u.s.bb_owner == cpu_to_be32(bbcoi->new_owner))
4461 return 0;
4462 block->bb_u.s.bb_owner = cpu_to_be32(bbcoi->new_owner);
4466 * If the block is a root block hosted in an inode, we might not have a
4467 * buffer pointer here and we shouldn't attempt to log the change as the
4468 * information is already held in the inode and discarded when the root
4469 * block is formatted into the on-disk inode fork. We still change it,
4470 * though, so everything is consistent in memory.
4472 if (!bp) {
4473 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
4474 ASSERT(level == cur->bc_nlevels - 1);
4475 return 0;
4478 if (cur->bc_tp) {
4479 if (!xfs_trans_ordered_buf(cur->bc_tp, bp)) {
4480 xfs_btree_log_block(cur, bp, XFS_BB_OWNER);
4481 return -EAGAIN;
4483 } else {
4484 xfs_buf_delwri_queue(bp, bbcoi->buffer_list);
4487 return 0;
4491 xfs_btree_change_owner(
4492 struct xfs_btree_cur *cur,
4493 uint64_t new_owner,
4494 struct list_head *buffer_list)
4496 struct xfs_btree_block_change_owner_info bbcoi;
4498 bbcoi.new_owner = new_owner;
4499 bbcoi.buffer_list = buffer_list;
4501 return xfs_btree_visit_blocks(cur, xfs_btree_block_change_owner,
4502 &bbcoi);
4506 * xfs_btree_sblock_v5hdr_verify() -- verify the v5 fields of a short-format
4507 * btree block
4509 * @bp: buffer containing the btree block
4510 * @max_recs: pointer to the m_*_mxr max records field in the xfs mount
4511 * @pag_max_level: pointer to the per-ag max level field
4513 bool
4514 xfs_btree_sblock_v5hdr_verify(
4515 struct xfs_buf *bp)
4517 struct xfs_mount *mp = bp->b_target->bt_mount;
4518 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
4519 struct xfs_perag *pag = bp->b_pag;
4521 if (!xfs_sb_version_hascrc(&mp->m_sb))
4522 return false;
4523 if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid))
4524 return false;
4525 if (block->bb_u.s.bb_blkno != cpu_to_be64(bp->b_bn))
4526 return false;
4527 if (pag && be32_to_cpu(block->bb_u.s.bb_owner) != pag->pag_agno)
4528 return false;
4529 return true;
4533 * xfs_btree_sblock_verify() -- verify a short-format btree block
4535 * @bp: buffer containing the btree block
4536 * @max_recs: maximum records allowed in this btree node
4538 bool
4539 xfs_btree_sblock_verify(
4540 struct xfs_buf *bp,
4541 unsigned int max_recs)
4543 struct xfs_mount *mp = bp->b_target->bt_mount;
4544 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
4546 /* numrecs verification */
4547 if (be16_to_cpu(block->bb_numrecs) > max_recs)
4548 return false;
4550 /* sibling pointer verification */
4551 if (!block->bb_u.s.bb_leftsib ||
4552 (be32_to_cpu(block->bb_u.s.bb_leftsib) >= mp->m_sb.sb_agblocks &&
4553 block->bb_u.s.bb_leftsib != cpu_to_be32(NULLAGBLOCK)))
4554 return false;
4555 if (!block->bb_u.s.bb_rightsib ||
4556 (be32_to_cpu(block->bb_u.s.bb_rightsib) >= mp->m_sb.sb_agblocks &&
4557 block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK)))
4558 return false;
4560 return true;
4564 * Calculate the number of btree levels needed to store a given number of
4565 * records in a short-format btree.
4567 uint
4568 xfs_btree_compute_maxlevels(
4569 struct xfs_mount *mp,
4570 uint *limits,
4571 unsigned long len)
4573 uint level;
4574 unsigned long maxblocks;
4576 maxblocks = (len + limits[0] - 1) / limits[0];
4577 for (level = 1; maxblocks > 1; level++)
4578 maxblocks = (maxblocks + limits[1] - 1) / limits[1];
4579 return level;
4583 * Query a regular btree for all records overlapping a given interval.
4584 * Start with a LE lookup of the key of low_rec and return all records
4585 * until we find a record with a key greater than the key of high_rec.
4587 STATIC int
4588 xfs_btree_simple_query_range(
4589 struct xfs_btree_cur *cur,
4590 union xfs_btree_key *low_key,
4591 union xfs_btree_key *high_key,
4592 xfs_btree_query_range_fn fn,
4593 void *priv)
4595 union xfs_btree_rec *recp;
4596 union xfs_btree_key rec_key;
4597 int64_t diff;
4598 int stat;
4599 bool firstrec = true;
4600 int error;
4602 ASSERT(cur->bc_ops->init_high_key_from_rec);
4603 ASSERT(cur->bc_ops->diff_two_keys);
4606 * Find the leftmost record. The btree cursor must be set
4607 * to the low record used to generate low_key.
4609 stat = 0;
4610 error = xfs_btree_lookup(cur, XFS_LOOKUP_LE, &stat);
4611 if (error)
4612 goto out;
4614 /* Nothing? See if there's anything to the right. */
4615 if (!stat) {
4616 error = xfs_btree_increment(cur, 0, &stat);
4617 if (error)
4618 goto out;
4621 while (stat) {
4622 /* Find the record. */
4623 error = xfs_btree_get_rec(cur, &recp, &stat);
4624 if (error || !stat)
4625 break;
4627 /* Skip if high_key(rec) < low_key. */
4628 if (firstrec) {
4629 cur->bc_ops->init_high_key_from_rec(&rec_key, recp);
4630 firstrec = false;
4631 diff = cur->bc_ops->diff_two_keys(cur, low_key,
4632 &rec_key);
4633 if (diff > 0)
4634 goto advloop;
4637 /* Stop if high_key < low_key(rec). */
4638 cur->bc_ops->init_key_from_rec(&rec_key, recp);
4639 diff = cur->bc_ops->diff_two_keys(cur, &rec_key, high_key);
4640 if (diff > 0)
4641 break;
4643 /* Callback */
4644 error = fn(cur, recp, priv);
4645 if (error < 0 || error == XFS_BTREE_QUERY_RANGE_ABORT)
4646 break;
4648 advloop:
4649 /* Move on to the next record. */
4650 error = xfs_btree_increment(cur, 0, &stat);
4651 if (error)
4652 break;
4655 out:
4656 return error;
4660 * Query an overlapped interval btree for all records overlapping a given
4661 * interval. This function roughly follows the algorithm given in
4662 * "Interval Trees" of _Introduction to Algorithms_, which is section
4663 * 14.3 in the 2nd and 3rd editions.
4665 * First, generate keys for the low and high records passed in.
4667 * For any leaf node, generate the high and low keys for the record.
4668 * If the record keys overlap with the query low/high keys, pass the
4669 * record to the function iterator.
4671 * For any internal node, compare the low and high keys of each
4672 * pointer against the query low/high keys. If there's an overlap,
4673 * follow the pointer.
4675 * As an optimization, we stop scanning a block when we find a low key
4676 * that is greater than the query's high key.
4678 STATIC int
4679 xfs_btree_overlapped_query_range(
4680 struct xfs_btree_cur *cur,
4681 union xfs_btree_key *low_key,
4682 union xfs_btree_key *high_key,
4683 xfs_btree_query_range_fn fn,
4684 void *priv)
4686 union xfs_btree_ptr ptr;
4687 union xfs_btree_ptr *pp;
4688 union xfs_btree_key rec_key;
4689 union xfs_btree_key rec_hkey;
4690 union xfs_btree_key *lkp;
4691 union xfs_btree_key *hkp;
4692 union xfs_btree_rec *recp;
4693 struct xfs_btree_block *block;
4694 int64_t ldiff;
4695 int64_t hdiff;
4696 int level;
4697 struct xfs_buf *bp;
4698 int i;
4699 int error;
4701 /* Load the root of the btree. */
4702 level = cur->bc_nlevels - 1;
4703 cur->bc_ops->init_ptr_from_cur(cur, &ptr);
4704 error = xfs_btree_lookup_get_block(cur, level, &ptr, &block);
4705 if (error)
4706 return error;
4707 xfs_btree_get_block(cur, level, &bp);
4708 trace_xfs_btree_overlapped_query_range(cur, level, bp);
4709 #ifdef DEBUG
4710 error = xfs_btree_check_block(cur, block, level, bp);
4711 if (error)
4712 goto out;
4713 #endif
4714 cur->bc_ptrs[level] = 1;
4716 while (level < cur->bc_nlevels) {
4717 block = xfs_btree_get_block(cur, level, &bp);
4719 /* End of node, pop back towards the root. */
4720 if (cur->bc_ptrs[level] > be16_to_cpu(block->bb_numrecs)) {
4721 pop_up:
4722 if (level < cur->bc_nlevels - 1)
4723 cur->bc_ptrs[level + 1]++;
4724 level++;
4725 continue;
4728 if (level == 0) {
4729 /* Handle a leaf node. */
4730 recp = xfs_btree_rec_addr(cur, cur->bc_ptrs[0], block);
4732 cur->bc_ops->init_high_key_from_rec(&rec_hkey, recp);
4733 ldiff = cur->bc_ops->diff_two_keys(cur, &rec_hkey,
4734 low_key);
4736 cur->bc_ops->init_key_from_rec(&rec_key, recp);
4737 hdiff = cur->bc_ops->diff_two_keys(cur, high_key,
4738 &rec_key);
4741 * If (record's high key >= query's low key) and
4742 * (query's high key >= record's low key), then
4743 * this record overlaps the query range; callback.
4745 if (ldiff >= 0 && hdiff >= 0) {
4746 error = fn(cur, recp, priv);
4747 if (error < 0 ||
4748 error == XFS_BTREE_QUERY_RANGE_ABORT)
4749 break;
4750 } else if (hdiff < 0) {
4751 /* Record is larger than high key; pop. */
4752 goto pop_up;
4754 cur->bc_ptrs[level]++;
4755 continue;
4758 /* Handle an internal node. */
4759 lkp = xfs_btree_key_addr(cur, cur->bc_ptrs[level], block);
4760 hkp = xfs_btree_high_key_addr(cur, cur->bc_ptrs[level], block);
4761 pp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[level], block);
4763 ldiff = cur->bc_ops->diff_two_keys(cur, hkp, low_key);
4764 hdiff = cur->bc_ops->diff_two_keys(cur, high_key, lkp);
4767 * If (pointer's high key >= query's low key) and
4768 * (query's high key >= pointer's low key), then
4769 * this record overlaps the query range; follow pointer.
4771 if (ldiff >= 0 && hdiff >= 0) {
4772 level--;
4773 error = xfs_btree_lookup_get_block(cur, level, pp,
4774 &block);
4775 if (error)
4776 goto out;
4777 xfs_btree_get_block(cur, level, &bp);
4778 trace_xfs_btree_overlapped_query_range(cur, level, bp);
4779 #ifdef DEBUG
4780 error = xfs_btree_check_block(cur, block, level, bp);
4781 if (error)
4782 goto out;
4783 #endif
4784 cur->bc_ptrs[level] = 1;
4785 continue;
4786 } else if (hdiff < 0) {
4787 /* The low key is larger than the upper range; pop. */
4788 goto pop_up;
4790 cur->bc_ptrs[level]++;
4793 out:
4795 * If we don't end this function with the cursor pointing at a record
4796 * block, a subsequent non-error cursor deletion will not release
4797 * node-level buffers, causing a buffer leak. This is quite possible
4798 * with a zero-results range query, so release the buffers if we
4799 * failed to return any results.
4801 if (cur->bc_bufs[0] == NULL) {
4802 for (i = 0; i < cur->bc_nlevels; i++) {
4803 if (cur->bc_bufs[i]) {
4804 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[i]);
4805 cur->bc_bufs[i] = NULL;
4806 cur->bc_ptrs[i] = 0;
4807 cur->bc_ra[i] = 0;
4812 return error;
4816 * Query a btree for all records overlapping a given interval of keys. The
4817 * supplied function will be called with each record found; return one of the
4818 * XFS_BTREE_QUERY_RANGE_{CONTINUE,ABORT} values or the usual negative error
4819 * code. This function returns XFS_BTREE_QUERY_RANGE_ABORT, zero, or a
4820 * negative error code.
4823 xfs_btree_query_range(
4824 struct xfs_btree_cur *cur,
4825 union xfs_btree_irec *low_rec,
4826 union xfs_btree_irec *high_rec,
4827 xfs_btree_query_range_fn fn,
4828 void *priv)
4830 union xfs_btree_rec rec;
4831 union xfs_btree_key low_key;
4832 union xfs_btree_key high_key;
4834 /* Find the keys of both ends of the interval. */
4835 cur->bc_rec = *high_rec;
4836 cur->bc_ops->init_rec_from_cur(cur, &rec);
4837 cur->bc_ops->init_key_from_rec(&high_key, &rec);
4839 cur->bc_rec = *low_rec;
4840 cur->bc_ops->init_rec_from_cur(cur, &rec);
4841 cur->bc_ops->init_key_from_rec(&low_key, &rec);
4843 /* Enforce low key < high key. */
4844 if (cur->bc_ops->diff_two_keys(cur, &low_key, &high_key) > 0)
4845 return -EINVAL;
4847 if (!(cur->bc_flags & XFS_BTREE_OVERLAPPING))
4848 return xfs_btree_simple_query_range(cur, &low_key,
4849 &high_key, fn, priv);
4850 return xfs_btree_overlapped_query_range(cur, &low_key, &high_key,
4851 fn, priv);
4854 /* Query a btree for all records. */
4856 xfs_btree_query_all(
4857 struct xfs_btree_cur *cur,
4858 xfs_btree_query_range_fn fn,
4859 void *priv)
4861 union xfs_btree_key low_key;
4862 union xfs_btree_key high_key;
4864 memset(&cur->bc_rec, 0, sizeof(cur->bc_rec));
4865 memset(&low_key, 0, sizeof(low_key));
4866 memset(&high_key, 0xFF, sizeof(high_key));
4868 return xfs_btree_simple_query_range(cur, &low_key, &high_key, fn, priv);
4872 * Calculate the number of blocks needed to store a given number of records
4873 * in a short-format (per-AG metadata) btree.
4875 xfs_extlen_t
4876 xfs_btree_calc_size(
4877 struct xfs_mount *mp,
4878 uint *limits,
4879 unsigned long long len)
4881 int level;
4882 int maxrecs;
4883 xfs_extlen_t rval;
4885 maxrecs = limits[0];
4886 for (level = 0, rval = 0; len > 1; level++) {
4887 len += maxrecs - 1;
4888 do_div(len, maxrecs);
4889 maxrecs = limits[1];
4890 rval += len;
4892 return rval;
4895 static int
4896 xfs_btree_count_blocks_helper(
4897 struct xfs_btree_cur *cur,
4898 int level,
4899 void *data)
4901 xfs_extlen_t *blocks = data;
4902 (*blocks)++;
4904 return 0;
4907 /* Count the blocks in a btree and return the result in *blocks. */
4909 xfs_btree_count_blocks(
4910 struct xfs_btree_cur *cur,
4911 xfs_extlen_t *blocks)
4913 *blocks = 0;
4914 return xfs_btree_visit_blocks(cur, xfs_btree_count_blocks_helper,
4915 blocks);