1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
4 * All Rights Reserved.
5 */
6 #include "xfs.h"
7 #include "xfs_fs.h"
8 #include "xfs_shared.h"
9 #include "xfs_format.h"
10 #include "xfs_log_format.h"
11 #include "xfs_trans_resv.h"
12 #include "xfs_bit.h"
13 #include "xfs_mount.h"
14 #include "xfs_inode.h"
15 #include "xfs_trans.h"
16 #include "xfs_buf_item.h"
17 #include "xfs_btree.h"
18 #include "xfs_errortag.h"
19 #include "xfs_error.h"
20 #include "xfs_trace.h"
21 #include "xfs_alloc.h"
22 #include "xfs_log.h"
23 #include "xfs_btree_staging.h"
24 #include "xfs_ag.h"
25
26 /*
27 * Cursor allocation zone.
28 */
29 kmem_zone_t *xfs_btree_cur_zone;
30
31 /*
32 * Btree magic numbers.
33 */
34 static const uint32_t xfs_magics[2][XFS_BTNUM_MAX] = {
35 { XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, 0, XFS_BMAP_MAGIC, XFS_IBT_MAGIC,
36 XFS_FIBT_MAGIC, 0 },
37 { XFS_ABTB_CRC_MAGIC, XFS_ABTC_CRC_MAGIC, XFS_RMAP_CRC_MAGIC,
38 XFS_BMAP_CRC_MAGIC, XFS_IBT_CRC_MAGIC, XFS_FIBT_CRC_MAGIC,
39 XFS_REFC_CRC_MAGIC }
40 };
41
42 uint32_t
xfs_btree_magic(int crc,xfs_btnum_t btnum)43 xfs_btree_magic(
44 int crc,
45 xfs_btnum_t btnum)
46 {
47 uint32_t magic = xfs_magics[crc][btnum];
48
49 /* Ensure we asked for crc for crc-only magics. */
50 ASSERT(magic != 0);
51 return magic;
52 }
53
54 /*
55 * These sibling pointer checks are optimised for null sibling pointers. This
56 * happens a lot, and we don't need to byte swap at runtime if the sibling
57 * pointer is NULL.
58 *
59 * These are explicitly marked at inline because the cost of calling them as
60 * functions instead of inlining them is about 36 bytes extra code per call site
61 * on x86-64. Yes, gcc-11 fails to inline them, and explicit inlining of these
62 * two sibling check functions reduces the compiled code size by over 300
63 * bytes.
64 */
65 static inline xfs_failaddr_t
xfs_btree_check_lblock_siblings(struct xfs_mount * mp,struct xfs_btree_cur * cur,int level,xfs_fsblock_t fsb,__be64 dsibling)66 xfs_btree_check_lblock_siblings(
67 struct xfs_mount *mp,
68 struct xfs_btree_cur *cur,
69 int level,
70 xfs_fsblock_t fsb,
71 __be64 dsibling)
72 {
73 xfs_fsblock_t sibling;
74
75 if (dsibling == cpu_to_be64(NULLFSBLOCK))
76 return NULL;
77
78 sibling = be64_to_cpu(dsibling);
79 if (sibling == fsb)
80 return __this_address;
81 if (level >= 0) {
82 if (!xfs_btree_check_lptr(cur, sibling, level + 1))
83 return __this_address;
84 } else {
85 if (!xfs_verify_fsbno(mp, sibling))
86 return __this_address;
87 }
88
89 return NULL;
90 }
91
92 static inline xfs_failaddr_t
xfs_btree_check_sblock_siblings(struct xfs_mount * mp,struct xfs_btree_cur * cur,int level,xfs_agnumber_t agno,xfs_agblock_t agbno,__be32 dsibling)93 xfs_btree_check_sblock_siblings(
94 struct xfs_mount *mp,
95 struct xfs_btree_cur *cur,
96 int level,
97 xfs_agnumber_t agno,
98 xfs_agblock_t agbno,
99 __be32 dsibling)
100 {
101 xfs_agblock_t sibling;
102
103 if (dsibling == cpu_to_be32(NULLAGBLOCK))
104 return NULL;
105
106 sibling = be32_to_cpu(dsibling);
107 if (sibling == agbno)
108 return __this_address;
109 if (level >= 0) {
110 if (!xfs_btree_check_sptr(cur, sibling, level + 1))
111 return __this_address;
112 } else {
113 if (!xfs_verify_agbno(mp, agno, sibling))
114 return __this_address;
115 }
116 return NULL;
117 }
118
119 /*
120 * Check a long btree block header. Return the address of the failing check,
121 * or NULL if everything is ok.
122 */
123 xfs_failaddr_t
__xfs_btree_check_lblock(struct xfs_btree_cur * cur,struct xfs_btree_block * block,int level,struct xfs_buf * bp)124 __xfs_btree_check_lblock(
125 struct xfs_btree_cur *cur,
126 struct xfs_btree_block *block,
127 int level,
128 struct xfs_buf *bp)
129 {
130 struct xfs_mount *mp = cur->bc_mp;
131 xfs_btnum_t btnum = cur->bc_btnum;
132 int crc = xfs_has_crc(mp);
133 xfs_failaddr_t fa;
134 xfs_fsblock_t fsb = NULLFSBLOCK;
135
136 if (crc) {
137 if (!uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid))
138 return __this_address;
139 if (block->bb_u.l.bb_blkno !=
140 cpu_to_be64(bp ? xfs_buf_daddr(bp) : XFS_BUF_DADDR_NULL))
141 return __this_address;
142 if (block->bb_u.l.bb_pad != cpu_to_be32(0))
143 return __this_address;
144 }
145
146 if (be32_to_cpu(block->bb_magic) != xfs_btree_magic(crc, btnum))
147 return __this_address;
148 if (be16_to_cpu(block->bb_level) != level)
149 return __this_address;
150 if (be16_to_cpu(block->bb_numrecs) >
151 cur->bc_ops->get_maxrecs(cur, level))
152 return __this_address;
153
154 if (bp)
155 fsb = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp));
156
157 fa = xfs_btree_check_lblock_siblings(mp, cur, level, fsb,
158 block->bb_u.l.bb_leftsib);
159 if (!fa)
160 fa = xfs_btree_check_lblock_siblings(mp, cur, level, fsb,
161 block->bb_u.l.bb_rightsib);
162 return fa;
163 }
164
165 /* Check a long btree block header. */
166 static int
xfs_btree_check_lblock(struct xfs_btree_cur * cur,struct xfs_btree_block * block,int level,struct xfs_buf * bp)167 xfs_btree_check_lblock(
168 struct xfs_btree_cur *cur,
169 struct xfs_btree_block *block,
170 int level,
171 struct xfs_buf *bp)
172 {
173 struct xfs_mount *mp = cur->bc_mp;
174 xfs_failaddr_t fa;
175
176 fa = __xfs_btree_check_lblock(cur, block, level, bp);
177 if (XFS_IS_CORRUPT(mp, fa != NULL) ||
178 XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BTREE_CHECK_LBLOCK)) {
179 if (bp)
180 trace_xfs_btree_corrupt(bp, _RET_IP_);
181 return -EFSCORRUPTED;
182 }
183 return 0;
184 }
185
186 /*
187 * Check a short btree block header. Return the address of the failing check,
188 * or NULL if everything is ok.
189 */
190 xfs_failaddr_t
__xfs_btree_check_sblock(struct xfs_btree_cur * cur,struct xfs_btree_block * block,int level,struct xfs_buf * bp)191 __xfs_btree_check_sblock(
192 struct xfs_btree_cur *cur,
193 struct xfs_btree_block *block,
194 int level,
195 struct xfs_buf *bp)
196 {
197 struct xfs_mount *mp = cur->bc_mp;
198 xfs_btnum_t btnum = cur->bc_btnum;
199 int crc = xfs_has_crc(mp);
200 xfs_failaddr_t fa;
201 xfs_agblock_t agbno = NULLAGBLOCK;
202 xfs_agnumber_t agno = NULLAGNUMBER;
203
204 if (crc) {
205 if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid))
206 return __this_address;
207 if (block->bb_u.s.bb_blkno !=
208 cpu_to_be64(bp ? xfs_buf_daddr(bp) : XFS_BUF_DADDR_NULL))
209 return __this_address;
210 }
211
212 if (be32_to_cpu(block->bb_magic) != xfs_btree_magic(crc, btnum))
213 return __this_address;
214 if (be16_to_cpu(block->bb_level) != level)
215 return __this_address;
216 if (be16_to_cpu(block->bb_numrecs) >
217 cur->bc_ops->get_maxrecs(cur, level))
218 return __this_address;
219
220 if (bp) {
221 agbno = xfs_daddr_to_agbno(mp, xfs_buf_daddr(bp));
222 agno = xfs_daddr_to_agno(mp, xfs_buf_daddr(bp));
223 }
224
225 fa = xfs_btree_check_sblock_siblings(mp, cur, level, agno, agbno,
226 block->bb_u.s.bb_leftsib);
227 if (!fa)
228 fa = xfs_btree_check_sblock_siblings(mp, cur, level, agno,
229 agbno, block->bb_u.s.bb_rightsib);
230 return fa;
231 }
232
233 /* Check a short btree block header. */
234 STATIC int
xfs_btree_check_sblock(struct xfs_btree_cur * cur,struct xfs_btree_block * block,int level,struct xfs_buf * bp)235 xfs_btree_check_sblock(
236 struct xfs_btree_cur *cur,
237 struct xfs_btree_block *block,
238 int level,
239 struct xfs_buf *bp)
240 {
241 struct xfs_mount *mp = cur->bc_mp;
242 xfs_failaddr_t fa;
243
244 fa = __xfs_btree_check_sblock(cur, block, level, bp);
245 if (XFS_IS_CORRUPT(mp, fa != NULL) ||
246 XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BTREE_CHECK_SBLOCK)) {
247 if (bp)
248 trace_xfs_btree_corrupt(bp, _RET_IP_);
249 return -EFSCORRUPTED;
250 }
251 return 0;
252 }
253
254 /*
255 * Debug routine: check that block header is ok.
256 */
257 int
xfs_btree_check_block(struct xfs_btree_cur * cur,struct xfs_btree_block * block,int level,struct xfs_buf * bp)258 xfs_btree_check_block(
259 struct xfs_btree_cur *cur, /* btree cursor */
260 struct xfs_btree_block *block, /* generic btree block pointer */
261 int level, /* level of the btree block */
262 struct xfs_buf *bp) /* buffer containing block, if any */
263 {
264 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
265 return xfs_btree_check_lblock(cur, block, level, bp);
266 else
267 return xfs_btree_check_sblock(cur, block, level, bp);
268 }
269
270 /* Check that this long pointer is valid and points within the fs. */
271 bool
xfs_btree_check_lptr(struct xfs_btree_cur * cur,xfs_fsblock_t fsbno,int level)272 xfs_btree_check_lptr(
273 struct xfs_btree_cur *cur,
274 xfs_fsblock_t fsbno,
275 int level)
276 {
277 if (level <= 0)
278 return false;
279 return xfs_verify_fsbno(cur->bc_mp, fsbno);
280 }
281
282 /* Check that this short pointer is valid and points within the AG. */
283 bool
xfs_btree_check_sptr(struct xfs_btree_cur * cur,xfs_agblock_t agbno,int level)284 xfs_btree_check_sptr(
285 struct xfs_btree_cur *cur,
286 xfs_agblock_t agbno,
287 int level)
288 {
289 if (level <= 0)
290 return false;
291 return xfs_verify_agbno(cur->bc_mp, cur->bc_ag.pag->pag_agno, agbno);
292 }
293
294 /*
295 * Check that a given (indexed) btree pointer at a certain level of a
296 * btree is valid and doesn't point past where it should.
297 */
298 static int
xfs_btree_check_ptr(struct xfs_btree_cur * cur,const union xfs_btree_ptr * ptr,int index,int level)299 xfs_btree_check_ptr(
300 struct xfs_btree_cur *cur,
301 const union xfs_btree_ptr *ptr,
302 int index,
303 int level)
304 {
305 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
306 if (xfs_btree_check_lptr(cur, be64_to_cpu((&ptr->l)[index]),
307 level))
308 return 0;
309 xfs_err(cur->bc_mp,
310 "Inode %llu fork %d: Corrupt btree %d pointer at level %d index %d.",
311 cur->bc_ino.ip->i_ino,
312 cur->bc_ino.whichfork, cur->bc_btnum,
313 level, index);
314 } else {
315 if (xfs_btree_check_sptr(cur, be32_to_cpu((&ptr->s)[index]),
316 level))
317 return 0;
318 xfs_err(cur->bc_mp,
319 "AG %u: Corrupt btree %d pointer at level %d index %d.",
320 cur->bc_ag.pag->pag_agno, cur->bc_btnum,
321 level, index);
322 }
323
324 return -EFSCORRUPTED;
325 }
326
327 #ifdef DEBUG
328 # define xfs_btree_debug_check_ptr xfs_btree_check_ptr
329 #else
330 # define xfs_btree_debug_check_ptr(...) (0)
331 #endif
332
333 /*
334 * Calculate CRC on the whole btree block and stuff it into the
335 * long-form btree header.
336 *
337 * Prior to calculting the CRC, pull the LSN out of the buffer log item and put
338 * it into the buffer so recovery knows what the last modification was that made
339 * it to disk.
340 */
341 void
xfs_btree_lblock_calc_crc(struct xfs_buf * bp)342 xfs_btree_lblock_calc_crc(
343 struct xfs_buf *bp)
344 {
345 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
346 struct xfs_buf_log_item *bip = bp->b_log_item;
347
348 if (!xfs_has_crc(bp->b_mount))
349 return;
350 if (bip)
351 block->bb_u.l.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
352 xfs_buf_update_cksum(bp, XFS_BTREE_LBLOCK_CRC_OFF);
353 }
354
355 bool
xfs_btree_lblock_verify_crc(struct xfs_buf * bp)356 xfs_btree_lblock_verify_crc(
357 struct xfs_buf *bp)
358 {
359 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
360 struct xfs_mount *mp = bp->b_mount;
361
362 if (xfs_has_crc(mp)) {
363 if (!xfs_log_check_lsn(mp, be64_to_cpu(block->bb_u.l.bb_lsn)))
364 return false;
365 return xfs_buf_verify_cksum(bp, XFS_BTREE_LBLOCK_CRC_OFF);
366 }
367
368 return true;
369 }
370
371 /*
372 * Calculate CRC on the whole btree block and stuff it into the
373 * short-form btree header.
374 *
375 * Prior to calculting the CRC, pull the LSN out of the buffer log item and put
376 * it into the buffer so recovery knows what the last modification was that made
377 * it to disk.
378 */
379 void
xfs_btree_sblock_calc_crc(struct xfs_buf * bp)380 xfs_btree_sblock_calc_crc(
381 struct xfs_buf *bp)
382 {
383 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
384 struct xfs_buf_log_item *bip = bp->b_log_item;
385
386 if (!xfs_has_crc(bp->b_mount))
387 return;
388 if (bip)
389 block->bb_u.s.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
390 xfs_buf_update_cksum(bp, XFS_BTREE_SBLOCK_CRC_OFF);
391 }
392
393 bool
xfs_btree_sblock_verify_crc(struct xfs_buf * bp)394 xfs_btree_sblock_verify_crc(
395 struct xfs_buf *bp)
396 {
397 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
398 struct xfs_mount *mp = bp->b_mount;
399
400 if (xfs_has_crc(mp)) {
401 if (!xfs_log_check_lsn(mp, be64_to_cpu(block->bb_u.s.bb_lsn)))
402 return false;
403 return xfs_buf_verify_cksum(bp, XFS_BTREE_SBLOCK_CRC_OFF);
404 }
405
406 return true;
407 }
408
409 static int
xfs_btree_free_block(struct xfs_btree_cur * cur,struct xfs_buf * bp)410 xfs_btree_free_block(
411 struct xfs_btree_cur *cur,
412 struct xfs_buf *bp)
413 {
414 int error;
415
416 error = cur->bc_ops->free_block(cur, bp);
417 if (!error) {
418 xfs_trans_binval(cur->bc_tp, bp);
419 XFS_BTREE_STATS_INC(cur, free);
420 }
421 return error;
422 }
423
424 /*
425 * Delete the btree cursor.
426 */
427 void
xfs_btree_del_cursor(struct xfs_btree_cur * cur,int error)428 xfs_btree_del_cursor(
429 struct xfs_btree_cur *cur, /* btree cursor */
430 int error) /* del because of error */
431 {
432 int i; /* btree level */
433
434 /*
435 * Clear the buffer pointers and release the buffers. If we're doing
436 * this because of an error, inspect all of the entries in the bc_bufs
437 * array for buffers to be unlocked. This is because some of the btree
438 * code works from level n down to 0, and if we get an error along the
439 * way we won't have initialized all the entries down to 0.
440 */
441 for (i = 0; i < cur->bc_nlevels; i++) {
442 if (cur->bc_bufs[i])
443 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[i]);
444 else if (!error)
445 break;
446 }
447
448 /*
449 * If we are doing a BMBT update, the number of unaccounted blocks
450 * allocated during this cursor life time should be zero. If it's not
451 * zero, then we should be shut down or on our way to shutdown due to
452 * cancelling a dirty transaction on error.
453 */
454 ASSERT(cur->bc_btnum != XFS_BTNUM_BMAP || cur->bc_ino.allocated == 0 ||
455 xfs_is_shutdown(cur->bc_mp) || error != 0);
456 if (unlikely(cur->bc_flags & XFS_BTREE_STAGING))
457 kmem_free(cur->bc_ops);
458 if (!(cur->bc_flags & XFS_BTREE_LONG_PTRS) && cur->bc_ag.pag)
459 xfs_perag_put(cur->bc_ag.pag);
460 kmem_cache_free(xfs_btree_cur_zone, cur);
461 }
462
463 /*
464 * Duplicate the btree cursor.
465 * Allocate a new one, copy the record, re-get the buffers.
466 */
467 int /* error */
xfs_btree_dup_cursor(xfs_btree_cur_t * cur,xfs_btree_cur_t ** ncur)468 xfs_btree_dup_cursor(
469 xfs_btree_cur_t *cur, /* input cursor */
470 xfs_btree_cur_t **ncur) /* output cursor */
471 {
472 struct xfs_buf *bp; /* btree block's buffer pointer */
473 int error; /* error return value */
474 int i; /* level number of btree block */
475 xfs_mount_t *mp; /* mount structure for filesystem */
476 xfs_btree_cur_t *new; /* new cursor value */
477 xfs_trans_t *tp; /* transaction pointer, can be NULL */
478
479 tp = cur->bc_tp;
480 mp = cur->bc_mp;
481
482 /*
483 * Allocate a new cursor like the old one.
484 */
485 new = cur->bc_ops->dup_cursor(cur);
486
487 /*
488 * Copy the record currently in the cursor.
489 */
490 new->bc_rec = cur->bc_rec;
491
492 /*
493 * For each level current, re-get the buffer and copy the ptr value.
494 */
495 for (i = 0; i < new->bc_nlevels; i++) {
496 new->bc_ptrs[i] = cur->bc_ptrs[i];
497 new->bc_ra[i] = cur->bc_ra[i];
498 bp = cur->bc_bufs[i];
499 if (bp) {
500 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
501 xfs_buf_daddr(bp), mp->m_bsize,
502 0, &bp,
503 cur->bc_ops->buf_ops);
504 if (error) {
505 xfs_btree_del_cursor(new, error);
506 *ncur = NULL;
507 return error;
508 }
509 }
510 new->bc_bufs[i] = bp;
511 }
512 *ncur = new;
513 return 0;
514 }
515
516 /*
517 * XFS btree block layout and addressing:
518 *
519 * There are two types of blocks in the btree: leaf and non-leaf blocks.
520 *
521 * The leaf record start with a header then followed by records containing
522 * the values. A non-leaf block also starts with the same header, and
523 * then first contains lookup keys followed by an equal number of pointers
524 * to the btree blocks at the previous level.
525 *
526 * +--------+-------+-------+-------+-------+-------+-------+
527 * Leaf: | header | rec 1 | rec 2 | rec 3 | rec 4 | rec 5 | rec N |
528 * +--------+-------+-------+-------+-------+-------+-------+
529 *
530 * +--------+-------+-------+-------+-------+-------+-------+
531 * Non-Leaf: | header | key 1 | key 2 | key N | ptr 1 | ptr 2 | ptr N |
532 * +--------+-------+-------+-------+-------+-------+-------+
533 *
534 * The header is called struct xfs_btree_block for reasons better left unknown
535 * and comes in different versions for short (32bit) and long (64bit) block
536 * pointers. The record and key structures are defined by the btree instances
537 * and opaque to the btree core. The block pointers are simple disk endian
538 * integers, available in a short (32bit) and long (64bit) variant.
539 *
540 * The helpers below calculate the offset of a given record, key or pointer
541 * into a btree block (xfs_btree_*_offset) or return a pointer to the given
542 * record, key or pointer (xfs_btree_*_addr). Note that all addressing
543 * inside the btree block is done using indices starting at one, not zero!
544 *
545 * If XFS_BTREE_OVERLAPPING is set, then this btree supports keys containing
546 * overlapping intervals. In such a tree, records are still sorted lowest to
547 * highest and indexed by the smallest key value that refers to the record.
548 * However, nodes are different: each pointer has two associated keys -- one
549 * indexing the lowest key available in the block(s) below (the same behavior
550 * as the key in a regular btree) and another indexing the highest key
551 * available in the block(s) below. Because records are /not/ sorted by the
552 * highest key, all leaf block updates require us to compute the highest key
553 * that matches any record in the leaf and to recursively update the high keys
554 * in the nodes going further up in the tree, if necessary. Nodes look like
555 * this:
556 *
557 * +--------+-----+-----+-----+-----+-----+-------+-------+-----+
558 * Non-Leaf: | header | lo1 | hi1 | lo2 | hi2 | ... | ptr 1 | ptr 2 | ... |
559 * +--------+-----+-----+-----+-----+-----+-------+-------+-----+
560 *
561 * To perform an interval query on an overlapped tree, perform the usual
562 * depth-first search and use the low and high keys to decide if we can skip
563 * that particular node. If a leaf node is reached, return the records that
564 * intersect the interval. Note that an interval query may return numerous
565 * entries. For a non-overlapped tree, simply search for the record associated
566 * with the lowest key and iterate forward until a non-matching record is
567 * found. Section 14.3 ("Interval Trees") of _Introduction to Algorithms_ by
568 * Cormen, Leiserson, Rivest, and Stein (2nd or 3rd ed. only) discuss this in
569 * more detail.
570 *
571 * Why do we care about overlapping intervals? Let's say you have a bunch of
572 * reverse mapping records on a reflink filesystem:
573 *
574 * 1: +- file A startblock B offset C length D -----------+
575 * 2: +- file E startblock F offset G length H --------------+
576 * 3: +- file I startblock F offset J length K --+
577 * 4: +- file L... --+
578 *
579 * Now say we want to map block (B+D) into file A at offset (C+D). Ideally,
580 * we'd simply increment the length of record 1. But how do we find the record
581 * that ends at (B+D-1) (i.e. record 1)? A LE lookup of (B+D-1) would return
582 * record 3 because the keys are ordered first by startblock. An interval
583 * query would return records 1 and 2 because they both overlap (B+D-1), and
584 * from that we can pick out record 1 as the appropriate left neighbor.
585 *
586 * In the non-overlapped case you can do a LE lookup and decrement the cursor
587 * because a record's interval must end before the next record.
588 */
589
590 /*
591 * Return size of the btree block header for this btree instance.
592 */
xfs_btree_block_len(struct xfs_btree_cur * cur)593 static inline size_t xfs_btree_block_len(struct xfs_btree_cur *cur)
594 {
595 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
596 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
597 return XFS_BTREE_LBLOCK_CRC_LEN;
598 return XFS_BTREE_LBLOCK_LEN;
599 }
600 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
601 return XFS_BTREE_SBLOCK_CRC_LEN;
602 return XFS_BTREE_SBLOCK_LEN;
603 }
604
605 /*
606 * Return size of btree block pointers for this btree instance.
607 */
xfs_btree_ptr_len(struct xfs_btree_cur * cur)608 static inline size_t xfs_btree_ptr_len(struct xfs_btree_cur *cur)
609 {
610 return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
611 sizeof(__be64) : sizeof(__be32);
612 }
613
614 /*
615 * Calculate offset of the n-th record in a btree block.
616 */
617 STATIC size_t
xfs_btree_rec_offset(struct xfs_btree_cur * cur,int n)618 xfs_btree_rec_offset(
619 struct xfs_btree_cur *cur,
620 int n)
621 {
622 return xfs_btree_block_len(cur) +
623 (n - 1) * cur->bc_ops->rec_len;
624 }
625
626 /*
627 * Calculate offset of the n-th key in a btree block.
628 */
629 STATIC size_t
xfs_btree_key_offset(struct xfs_btree_cur * cur,int n)630 xfs_btree_key_offset(
631 struct xfs_btree_cur *cur,
632 int n)
633 {
634 return xfs_btree_block_len(cur) +
635 (n - 1) * cur->bc_ops->key_len;
636 }
637
638 /*
639 * Calculate offset of the n-th high key in a btree block.
640 */
641 STATIC size_t
xfs_btree_high_key_offset(struct xfs_btree_cur * cur,int n)642 xfs_btree_high_key_offset(
643 struct xfs_btree_cur *cur,
644 int n)
645 {
646 return xfs_btree_block_len(cur) +
647 (n - 1) * cur->bc_ops->key_len + (cur->bc_ops->key_len / 2);
648 }
649
650 /*
651 * Calculate offset of the n-th block pointer in a btree block.
652 */
653 STATIC size_t
xfs_btree_ptr_offset(struct xfs_btree_cur * cur,int n,int level)654 xfs_btree_ptr_offset(
655 struct xfs_btree_cur *cur,
656 int n,
657 int level)
658 {
659 return xfs_btree_block_len(cur) +
660 cur->bc_ops->get_maxrecs(cur, level) * cur->bc_ops->key_len +
661 (n - 1) * xfs_btree_ptr_len(cur);
662 }
663
664 /*
665 * Return a pointer to the n-th record in the btree block.
666 */
667 union xfs_btree_rec *
xfs_btree_rec_addr(struct xfs_btree_cur * cur,int n,struct xfs_btree_block * block)668 xfs_btree_rec_addr(
669 struct xfs_btree_cur *cur,
670 int n,
671 struct xfs_btree_block *block)
672 {
673 return (union xfs_btree_rec *)
674 ((char *)block + xfs_btree_rec_offset(cur, n));
675 }
676
677 /*
678 * Return a pointer to the n-th key in the btree block.
679 */
680 union xfs_btree_key *
xfs_btree_key_addr(struct xfs_btree_cur * cur,int n,struct xfs_btree_block * block)681 xfs_btree_key_addr(
682 struct xfs_btree_cur *cur,
683 int n,
684 struct xfs_btree_block *block)
685 {
686 return (union xfs_btree_key *)
687 ((char *)block + xfs_btree_key_offset(cur, n));
688 }
689
690 /*
691 * Return a pointer to the n-th high key in the btree block.
692 */
693 union xfs_btree_key *
xfs_btree_high_key_addr(struct xfs_btree_cur * cur,int n,struct xfs_btree_block * block)694 xfs_btree_high_key_addr(
695 struct xfs_btree_cur *cur,
696 int n,
697 struct xfs_btree_block *block)
698 {
699 return (union xfs_btree_key *)
700 ((char *)block + xfs_btree_high_key_offset(cur, n));
701 }
702
703 /*
704 * Return a pointer to the n-th block pointer in the btree block.
705 */
706 union xfs_btree_ptr *
xfs_btree_ptr_addr(struct xfs_btree_cur * cur,int n,struct xfs_btree_block * block)707 xfs_btree_ptr_addr(
708 struct xfs_btree_cur *cur,
709 int n,
710 struct xfs_btree_block *block)
711 {
712 int level = xfs_btree_get_level(block);
713
714 ASSERT(block->bb_level != 0);
715
716 return (union xfs_btree_ptr *)
717 ((char *)block + xfs_btree_ptr_offset(cur, n, level));
718 }
719
720 struct xfs_ifork *
xfs_btree_ifork_ptr(struct xfs_btree_cur * cur)721 xfs_btree_ifork_ptr(
722 struct xfs_btree_cur *cur)
723 {
724 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
725
726 if (cur->bc_flags & XFS_BTREE_STAGING)
727 return cur->bc_ino.ifake->if_fork;
728 return XFS_IFORK_PTR(cur->bc_ino.ip, cur->bc_ino.whichfork);
729 }
730
731 /*
732 * Get the root block which is stored in the inode.
733 *
734 * For now this btree implementation assumes the btree root is always
735 * stored in the if_broot field of an inode fork.
736 */
737 STATIC struct xfs_btree_block *
xfs_btree_get_iroot(struct xfs_btree_cur * cur)738 xfs_btree_get_iroot(
739 struct xfs_btree_cur *cur)
740 {
741 struct xfs_ifork *ifp = xfs_btree_ifork_ptr(cur);
742
743 return (struct xfs_btree_block *)ifp->if_broot;
744 }
745
746 /*
747 * Retrieve the block pointer from the cursor at the given level.
748 * This may be an inode btree root or from a buffer.
749 */
750 struct xfs_btree_block * /* generic btree block pointer */
xfs_btree_get_block(struct xfs_btree_cur * cur,int level,struct xfs_buf ** bpp)751 xfs_btree_get_block(
752 struct xfs_btree_cur *cur, /* btree cursor */
753 int level, /* level in btree */
754 struct xfs_buf **bpp) /* buffer containing the block */
755 {
756 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
757 (level == cur->bc_nlevels - 1)) {
758 *bpp = NULL;
759 return xfs_btree_get_iroot(cur);
760 }
761
762 *bpp = cur->bc_bufs[level];
763 return XFS_BUF_TO_BLOCK(*bpp);
764 }
765
766 /*
767 * Change the cursor to point to the first record at the given level.
768 * Other levels are unaffected.
769 */
770 STATIC int /* success=1, failure=0 */
xfs_btree_firstrec(xfs_btree_cur_t * cur,int level)771 xfs_btree_firstrec(
772 xfs_btree_cur_t *cur, /* btree cursor */
773 int level) /* level to change */
774 {
775 struct xfs_btree_block *block; /* generic btree block pointer */
776 struct xfs_buf *bp; /* buffer containing block */
777
778 /*
779 * Get the block pointer for this level.
780 */
781 block = xfs_btree_get_block(cur, level, &bp);
782 if (xfs_btree_check_block(cur, block, level, bp))
783 return 0;
784 /*
785 * It's empty, there is no such record.
786 */
787 if (!block->bb_numrecs)
788 return 0;
789 /*
790 * Set the ptr value to 1, that's the first record/key.
791 */
792 cur->bc_ptrs[level] = 1;
793 return 1;
794 }
795
796 /*
797 * Change the cursor to point to the last record in the current block
798 * at the given level. Other levels are unaffected.
799 */
800 STATIC int /* success=1, failure=0 */
xfs_btree_lastrec(xfs_btree_cur_t * cur,int level)801 xfs_btree_lastrec(
802 xfs_btree_cur_t *cur, /* btree cursor */
803 int level) /* level to change */
804 {
805 struct xfs_btree_block *block; /* generic btree block pointer */
806 struct xfs_buf *bp; /* buffer containing block */
807
808 /*
809 * Get the block pointer for this level.
810 */
811 block = xfs_btree_get_block(cur, level, &bp);
812 if (xfs_btree_check_block(cur, block, level, bp))
813 return 0;
814 /*
815 * It's empty, there is no such record.
816 */
817 if (!block->bb_numrecs)
818 return 0;
819 /*
820 * Set the ptr value to numrecs, that's the last record/key.
821 */
822 cur->bc_ptrs[level] = be16_to_cpu(block->bb_numrecs);
823 return 1;
824 }
825
826 /*
827 * Compute first and last byte offsets for the fields given.
828 * Interprets the offsets table, which contains struct field offsets.
829 */
830 void
xfs_btree_offsets(int64_t fields,const short * offsets,int nbits,int * first,int * last)831 xfs_btree_offsets(
832 int64_t fields, /* bitmask of fields */
833 const short *offsets, /* table of field offsets */
834 int nbits, /* number of bits to inspect */
835 int *first, /* output: first byte offset */
836 int *last) /* output: last byte offset */
837 {
838 int i; /* current bit number */
839 int64_t imask; /* mask for current bit number */
840
841 ASSERT(fields != 0);
842 /*
843 * Find the lowest bit, so the first byte offset.
844 */
845 for (i = 0, imask = 1LL; ; i++, imask <<= 1) {
846 if (imask & fields) {
847 *first = offsets[i];
848 break;
849 }
850 }
851 /*
852 * Find the highest bit, so the last byte offset.
853 */
854 for (i = nbits - 1, imask = 1LL << i; ; i--, imask >>= 1) {
855 if (imask & fields) {
856 *last = offsets[i + 1] - 1;
857 break;
858 }
859 }
860 }
861
862 /*
863 * Get a buffer for the block, return it read in.
864 * Long-form addressing.
865 */
866 int
xfs_btree_read_bufl(struct xfs_mount * mp,struct xfs_trans * tp,xfs_fsblock_t fsbno,struct xfs_buf ** bpp,int refval,const struct xfs_buf_ops * ops)867 xfs_btree_read_bufl(
868 struct xfs_mount *mp, /* file system mount point */
869 struct xfs_trans *tp, /* transaction pointer */
870 xfs_fsblock_t fsbno, /* file system block number */
871 struct xfs_buf **bpp, /* buffer for fsbno */
872 int refval, /* ref count value for buffer */
873 const struct xfs_buf_ops *ops)
874 {
875 struct xfs_buf *bp; /* return value */
876 xfs_daddr_t d; /* real disk block address */
877 int error;
878
879 if (!xfs_verify_fsbno(mp, fsbno))
880 return -EFSCORRUPTED;
881 d = XFS_FSB_TO_DADDR(mp, fsbno);
882 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
883 mp->m_bsize, 0, &bp, ops);
884 if (error)
885 return error;
886 if (bp)
887 xfs_buf_set_ref(bp, refval);
888 *bpp = bp;
889 return 0;
890 }
891
892 /*
893 * Read-ahead the block, don't wait for it, don't return a buffer.
894 * Long-form addressing.
895 */
896 /* ARGSUSED */
897 void
xfs_btree_reada_bufl(struct xfs_mount * mp,xfs_fsblock_t fsbno,xfs_extlen_t count,const struct xfs_buf_ops * ops)898 xfs_btree_reada_bufl(
899 struct xfs_mount *mp, /* file system mount point */
900 xfs_fsblock_t fsbno, /* file system block number */
901 xfs_extlen_t count, /* count of filesystem blocks */
902 const struct xfs_buf_ops *ops)
903 {
904 xfs_daddr_t d;
905
906 ASSERT(fsbno != NULLFSBLOCK);
907 d = XFS_FSB_TO_DADDR(mp, fsbno);
908 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, ops);
909 }
910
911 /*
912 * Read-ahead the block, don't wait for it, don't return a buffer.
913 * Short-form addressing.
914 */
915 /* ARGSUSED */
916 void
xfs_btree_reada_bufs(struct xfs_mount * mp,xfs_agnumber_t agno,xfs_agblock_t agbno,xfs_extlen_t count,const struct xfs_buf_ops * ops)917 xfs_btree_reada_bufs(
918 struct xfs_mount *mp, /* file system mount point */
919 xfs_agnumber_t agno, /* allocation group number */
920 xfs_agblock_t agbno, /* allocation group block number */
921 xfs_extlen_t count, /* count of filesystem blocks */
922 const struct xfs_buf_ops *ops)
923 {
924 xfs_daddr_t d;
925
926 ASSERT(agno != NULLAGNUMBER);
927 ASSERT(agbno != NULLAGBLOCK);
928 d = XFS_AGB_TO_DADDR(mp, agno, agbno);
929 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, ops);
930 }
931
932 STATIC int
xfs_btree_readahead_lblock(struct xfs_btree_cur * cur,int lr,struct xfs_btree_block * block)933 xfs_btree_readahead_lblock(
934 struct xfs_btree_cur *cur,
935 int lr,
936 struct xfs_btree_block *block)
937 {
938 int rval = 0;
939 xfs_fsblock_t left = be64_to_cpu(block->bb_u.l.bb_leftsib);
940 xfs_fsblock_t right = be64_to_cpu(block->bb_u.l.bb_rightsib);
941
942 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLFSBLOCK) {
943 xfs_btree_reada_bufl(cur->bc_mp, left, 1,
944 cur->bc_ops->buf_ops);
945 rval++;
946 }
947
948 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLFSBLOCK) {
949 xfs_btree_reada_bufl(cur->bc_mp, right, 1,
950 cur->bc_ops->buf_ops);
951 rval++;
952 }
953
954 return rval;
955 }
956
957 STATIC int
xfs_btree_readahead_sblock(struct xfs_btree_cur * cur,int lr,struct xfs_btree_block * block)958 xfs_btree_readahead_sblock(
959 struct xfs_btree_cur *cur,
960 int lr,
961 struct xfs_btree_block *block)
962 {
963 int rval = 0;
964 xfs_agblock_t left = be32_to_cpu(block->bb_u.s.bb_leftsib);
965 xfs_agblock_t right = be32_to_cpu(block->bb_u.s.bb_rightsib);
966
967
968 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLAGBLOCK) {
969 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_ag.pag->pag_agno,
970 left, 1, cur->bc_ops->buf_ops);
971 rval++;
972 }
973
974 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLAGBLOCK) {
975 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_ag.pag->pag_agno,
976 right, 1, cur->bc_ops->buf_ops);
977 rval++;
978 }
979
980 return rval;
981 }
982
983 /*
984 * Read-ahead btree blocks, at the given level.
985 * Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA.
986 */
987 STATIC int
xfs_btree_readahead(struct xfs_btree_cur * cur,int lev,int lr)988 xfs_btree_readahead(
989 struct xfs_btree_cur *cur, /* btree cursor */
990 int lev, /* level in btree */
991 int lr) /* left/right bits */
992 {
993 struct xfs_btree_block *block;
994
995 /*
996 * No readahead needed if we are at the root level and the
997 * btree root is stored in the inode.
998 */
999 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1000 (lev == cur->bc_nlevels - 1))
1001 return 0;
1002
1003 if ((cur->bc_ra[lev] | lr) == cur->bc_ra[lev])
1004 return 0;
1005
1006 cur->bc_ra[lev] |= lr;
1007 block = XFS_BUF_TO_BLOCK(cur->bc_bufs[lev]);
1008
1009 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1010 return xfs_btree_readahead_lblock(cur, lr, block);
1011 return xfs_btree_readahead_sblock(cur, lr, block);
1012 }
1013
1014 STATIC int
xfs_btree_ptr_to_daddr(struct xfs_btree_cur * cur,const union xfs_btree_ptr * ptr,xfs_daddr_t * daddr)1015 xfs_btree_ptr_to_daddr(
1016 struct xfs_btree_cur *cur,
1017 const union xfs_btree_ptr *ptr,
1018 xfs_daddr_t *daddr)
1019 {
1020 xfs_fsblock_t fsbno;
1021 xfs_agblock_t agbno;
1022 int error;
1023
1024 error = xfs_btree_check_ptr(cur, ptr, 0, 1);
1025 if (error)
1026 return error;
1027
1028 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1029 fsbno = be64_to_cpu(ptr->l);
1030 *daddr = XFS_FSB_TO_DADDR(cur->bc_mp, fsbno);
1031 } else {
1032 agbno = be32_to_cpu(ptr->s);
1033 *daddr = XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_ag.pag->pag_agno,
1034 agbno);
1035 }
1036
1037 return 0;
1038 }
1039
1040 /*
1041 * Readahead @count btree blocks at the given @ptr location.
1042 *
1043 * We don't need to care about long or short form btrees here as we have a
1044 * method of converting the ptr directly to a daddr available to us.
1045 */
1046 STATIC void
xfs_btree_readahead_ptr(struct xfs_btree_cur * cur,union xfs_btree_ptr * ptr,xfs_extlen_t count)1047 xfs_btree_readahead_ptr(
1048 struct xfs_btree_cur *cur,
1049 union xfs_btree_ptr *ptr,
1050 xfs_extlen_t count)
1051 {
1052 xfs_daddr_t daddr;
1053
1054 if (xfs_btree_ptr_to_daddr(cur, ptr, &daddr))
1055 return;
1056 xfs_buf_readahead(cur->bc_mp->m_ddev_targp, daddr,
1057 cur->bc_mp->m_bsize * count, cur->bc_ops->buf_ops);
1058 }
1059
1060 /*
1061 * Set the buffer for level "lev" in the cursor to bp, releasing
1062 * any previous buffer.
1063 */
1064 STATIC void
xfs_btree_setbuf(xfs_btree_cur_t * cur,int lev,struct xfs_buf * bp)1065 xfs_btree_setbuf(
1066 xfs_btree_cur_t *cur, /* btree cursor */
1067 int lev, /* level in btree */
1068 struct xfs_buf *bp) /* new buffer to set */
1069 {
1070 struct xfs_btree_block *b; /* btree block */
1071
1072 if (cur->bc_bufs[lev])
1073 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[lev]);
1074 cur->bc_bufs[lev] = bp;
1075 cur->bc_ra[lev] = 0;
1076
1077 b = XFS_BUF_TO_BLOCK(bp);
1078 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1079 if (b->bb_u.l.bb_leftsib == cpu_to_be64(NULLFSBLOCK))
1080 cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
1081 if (b->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK))
1082 cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
1083 } else {
1084 if (b->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK))
1085 cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
1086 if (b->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK))
1087 cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
1088 }
1089 }
1090
1091 bool
xfs_btree_ptr_is_null(struct xfs_btree_cur * cur,const union xfs_btree_ptr * ptr)1092 xfs_btree_ptr_is_null(
1093 struct xfs_btree_cur *cur,
1094 const union xfs_btree_ptr *ptr)
1095 {
1096 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1097 return ptr->l == cpu_to_be64(NULLFSBLOCK);
1098 else
1099 return ptr->s == cpu_to_be32(NULLAGBLOCK);
1100 }
1101
1102 void
xfs_btree_set_ptr_null(struct xfs_btree_cur * cur,union xfs_btree_ptr * ptr)1103 xfs_btree_set_ptr_null(
1104 struct xfs_btree_cur *cur,
1105 union xfs_btree_ptr *ptr)
1106 {
1107 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1108 ptr->l = cpu_to_be64(NULLFSBLOCK);
1109 else
1110 ptr->s = cpu_to_be32(NULLAGBLOCK);
1111 }
1112
1113 /*
1114 * Get/set/init sibling pointers
1115 */
1116 void
xfs_btree_get_sibling(struct xfs_btree_cur * cur,struct xfs_btree_block * block,union xfs_btree_ptr * ptr,int lr)1117 xfs_btree_get_sibling(
1118 struct xfs_btree_cur *cur,
1119 struct xfs_btree_block *block,
1120 union xfs_btree_ptr *ptr,
1121 int lr)
1122 {
1123 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
1124
1125 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1126 if (lr == XFS_BB_RIGHTSIB)
1127 ptr->l = block->bb_u.l.bb_rightsib;
1128 else
1129 ptr->l = block->bb_u.l.bb_leftsib;
1130 } else {
1131 if (lr == XFS_BB_RIGHTSIB)
1132 ptr->s = block->bb_u.s.bb_rightsib;
1133 else
1134 ptr->s = block->bb_u.s.bb_leftsib;
1135 }
1136 }
1137
1138 void
xfs_btree_set_sibling(struct xfs_btree_cur * cur,struct xfs_btree_block * block,const union xfs_btree_ptr * ptr,int lr)1139 xfs_btree_set_sibling(
1140 struct xfs_btree_cur *cur,
1141 struct xfs_btree_block *block,
1142 const union xfs_btree_ptr *ptr,
1143 int lr)
1144 {
1145 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
1146
1147 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1148 if (lr == XFS_BB_RIGHTSIB)
1149 block->bb_u.l.bb_rightsib = ptr->l;
1150 else
1151 block->bb_u.l.bb_leftsib = ptr->l;
1152 } else {
1153 if (lr == XFS_BB_RIGHTSIB)
1154 block->bb_u.s.bb_rightsib = ptr->s;
1155 else
1156 block->bb_u.s.bb_leftsib = ptr->s;
1157 }
1158 }
1159
1160 void
xfs_btree_init_block_int(struct xfs_mount * mp,struct xfs_btree_block * buf,xfs_daddr_t blkno,xfs_btnum_t btnum,__u16 level,__u16 numrecs,__u64 owner,unsigned int flags)1161 xfs_btree_init_block_int(
1162 struct xfs_mount *mp,
1163 struct xfs_btree_block *buf,
1164 xfs_daddr_t blkno,
1165 xfs_btnum_t btnum,
1166 __u16 level,
1167 __u16 numrecs,
1168 __u64 owner,
1169 unsigned int flags)
1170 {
1171 int crc = xfs_has_crc(mp);
1172 __u32 magic = xfs_btree_magic(crc, btnum);
1173
1174 buf->bb_magic = cpu_to_be32(magic);
1175 buf->bb_level = cpu_to_be16(level);
1176 buf->bb_numrecs = cpu_to_be16(numrecs);
1177
1178 if (flags & XFS_BTREE_LONG_PTRS) {
1179 buf->bb_u.l.bb_leftsib = cpu_to_be64(NULLFSBLOCK);
1180 buf->bb_u.l.bb_rightsib = cpu_to_be64(NULLFSBLOCK);
1181 if (crc) {
1182 buf->bb_u.l.bb_blkno = cpu_to_be64(blkno);
1183 buf->bb_u.l.bb_owner = cpu_to_be64(owner);
1184 uuid_copy(&buf->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid);
1185 buf->bb_u.l.bb_pad = 0;
1186 buf->bb_u.l.bb_lsn = 0;
1187 }
1188 } else {
1189 /* owner is a 32 bit value on short blocks */
1190 __u32 __owner = (__u32)owner;
1191
1192 buf->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
1193 buf->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
1194 if (crc) {
1195 buf->bb_u.s.bb_blkno = cpu_to_be64(blkno);
1196 buf->bb_u.s.bb_owner = cpu_to_be32(__owner);
1197 uuid_copy(&buf->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid);
1198 buf->bb_u.s.bb_lsn = 0;
1199 }
1200 }
1201 }
1202
1203 void
xfs_btree_init_block(struct xfs_mount * mp,struct xfs_buf * bp,xfs_btnum_t btnum,__u16 level,__u16 numrecs,__u64 owner)1204 xfs_btree_init_block(
1205 struct xfs_mount *mp,
1206 struct xfs_buf *bp,
1207 xfs_btnum_t btnum,
1208 __u16 level,
1209 __u16 numrecs,
1210 __u64 owner)
1211 {
1212 xfs_btree_init_block_int(mp, XFS_BUF_TO_BLOCK(bp), xfs_buf_daddr(bp),
1213 btnum, level, numrecs, owner, 0);
1214 }
1215
1216 void
xfs_btree_init_block_cur(struct xfs_btree_cur * cur,struct xfs_buf * bp,int level,int numrecs)1217 xfs_btree_init_block_cur(
1218 struct xfs_btree_cur *cur,
1219 struct xfs_buf *bp,
1220 int level,
1221 int numrecs)
1222 {
1223 __u64 owner;
1224
1225 /*
1226 * we can pull the owner from the cursor right now as the different
1227 * owners align directly with the pointer size of the btree. This may
1228 * change in future, but is safe for current users of the generic btree
1229 * code.
1230 */
1231 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1232 owner = cur->bc_ino.ip->i_ino;
1233 else
1234 owner = cur->bc_ag.pag->pag_agno;
1235
1236 xfs_btree_init_block_int(cur->bc_mp, XFS_BUF_TO_BLOCK(bp),
1237 xfs_buf_daddr(bp), cur->bc_btnum, level,
1238 numrecs, owner, cur->bc_flags);
1239 }
1240
1241 /*
1242 * Return true if ptr is the last record in the btree and
1243 * we need to track updates to this record. The decision
1244 * will be further refined in the update_lastrec method.
1245 */
1246 STATIC int
xfs_btree_is_lastrec(struct xfs_btree_cur * cur,struct xfs_btree_block * block,int level)1247 xfs_btree_is_lastrec(
1248 struct xfs_btree_cur *cur,
1249 struct xfs_btree_block *block,
1250 int level)
1251 {
1252 union xfs_btree_ptr ptr;
1253
1254 if (level > 0)
1255 return 0;
1256 if (!(cur->bc_flags & XFS_BTREE_LASTREC_UPDATE))
1257 return 0;
1258
1259 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1260 if (!xfs_btree_ptr_is_null(cur, &ptr))
1261 return 0;
1262 return 1;
1263 }
1264
1265 STATIC void
xfs_btree_buf_to_ptr(struct xfs_btree_cur * cur,struct xfs_buf * bp,union xfs_btree_ptr * ptr)1266 xfs_btree_buf_to_ptr(
1267 struct xfs_btree_cur *cur,
1268 struct xfs_buf *bp,
1269 union xfs_btree_ptr *ptr)
1270 {
1271 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1272 ptr->l = cpu_to_be64(XFS_DADDR_TO_FSB(cur->bc_mp,
1273 xfs_buf_daddr(bp)));
1274 else {
1275 ptr->s = cpu_to_be32(xfs_daddr_to_agbno(cur->bc_mp,
1276 xfs_buf_daddr(bp)));
1277 }
1278 }
1279
1280 STATIC void
xfs_btree_set_refs(struct xfs_btree_cur * cur,struct xfs_buf * bp)1281 xfs_btree_set_refs(
1282 struct xfs_btree_cur *cur,
1283 struct xfs_buf *bp)
1284 {
1285 switch (cur->bc_btnum) {
1286 case XFS_BTNUM_BNO:
1287 case XFS_BTNUM_CNT:
1288 xfs_buf_set_ref(bp, XFS_ALLOC_BTREE_REF);
1289 break;
1290 case XFS_BTNUM_INO:
1291 case XFS_BTNUM_FINO:
1292 xfs_buf_set_ref(bp, XFS_INO_BTREE_REF);
1293 break;
1294 case XFS_BTNUM_BMAP:
1295 xfs_buf_set_ref(bp, XFS_BMAP_BTREE_REF);
1296 break;
1297 case XFS_BTNUM_RMAP:
1298 xfs_buf_set_ref(bp, XFS_RMAP_BTREE_REF);
1299 break;
1300 case XFS_BTNUM_REFC:
1301 xfs_buf_set_ref(bp, XFS_REFC_BTREE_REF);
1302 break;
1303 default:
1304 ASSERT(0);
1305 }
1306 }
1307
1308 int
xfs_btree_get_buf_block(struct xfs_btree_cur * cur,const union xfs_btree_ptr * ptr,struct xfs_btree_block ** block,struct xfs_buf ** bpp)1309 xfs_btree_get_buf_block(
1310 struct xfs_btree_cur *cur,
1311 const union xfs_btree_ptr *ptr,
1312 struct xfs_btree_block **block,
1313 struct xfs_buf **bpp)
1314 {
1315 struct xfs_mount *mp = cur->bc_mp;
1316 xfs_daddr_t d;
1317 int error;
1318
1319 error = xfs_btree_ptr_to_daddr(cur, ptr, &d);
1320 if (error)
1321 return error;
1322 error = xfs_trans_get_buf(cur->bc_tp, mp->m_ddev_targp, d, mp->m_bsize,
1323 0, bpp);
1324 if (error)
1325 return error;
1326
1327 (*bpp)->b_ops = cur->bc_ops->buf_ops;
1328 *block = XFS_BUF_TO_BLOCK(*bpp);
1329 return 0;
1330 }
1331
1332 /*
1333 * Read in the buffer at the given ptr and return the buffer and
1334 * the block pointer within the buffer.
1335 */
1336 STATIC int
xfs_btree_read_buf_block(struct xfs_btree_cur * cur,const union xfs_btree_ptr * ptr,int flags,struct xfs_btree_block ** block,struct xfs_buf ** bpp)1337 xfs_btree_read_buf_block(
1338 struct xfs_btree_cur *cur,
1339 const union xfs_btree_ptr *ptr,
1340 int flags,
1341 struct xfs_btree_block **block,
1342 struct xfs_buf **bpp)
1343 {
1344 struct xfs_mount *mp = cur->bc_mp;
1345 xfs_daddr_t d;
1346 int error;
1347
1348 /* need to sort out how callers deal with failures first */
1349 ASSERT(!(flags & XBF_TRYLOCK));
1350
1351 error = xfs_btree_ptr_to_daddr(cur, ptr, &d);
1352 if (error)
1353 return error;
1354 error = xfs_trans_read_buf(mp, cur->bc_tp, mp->m_ddev_targp, d,
1355 mp->m_bsize, flags, bpp,
1356 cur->bc_ops->buf_ops);
1357 if (error)
1358 return error;
1359
1360 xfs_btree_set_refs(cur, *bpp);
1361 *block = XFS_BUF_TO_BLOCK(*bpp);
1362 return 0;
1363 }
1364
1365 /*
1366 * Copy keys from one btree block to another.
1367 */
1368 void
xfs_btree_copy_keys(struct xfs_btree_cur * cur,union xfs_btree_key * dst_key,const union xfs_btree_key * src_key,int numkeys)1369 xfs_btree_copy_keys(
1370 struct xfs_btree_cur *cur,
1371 union xfs_btree_key *dst_key,
1372 const union xfs_btree_key *src_key,
1373 int numkeys)
1374 {
1375 ASSERT(numkeys >= 0);
1376 memcpy(dst_key, src_key, numkeys * cur->bc_ops->key_len);
1377 }
1378
1379 /*
1380 * Copy records from one btree block to another.
1381 */
1382 STATIC void
xfs_btree_copy_recs(struct xfs_btree_cur * cur,union xfs_btree_rec * dst_rec,union xfs_btree_rec * src_rec,int numrecs)1383 xfs_btree_copy_recs(
1384 struct xfs_btree_cur *cur,
1385 union xfs_btree_rec *dst_rec,
1386 union xfs_btree_rec *src_rec,
1387 int numrecs)
1388 {
1389 ASSERT(numrecs >= 0);
1390 memcpy(dst_rec, src_rec, numrecs * cur->bc_ops->rec_len);
1391 }
1392
1393 /*
1394 * Copy block pointers from one btree block to another.
1395 */
1396 void
xfs_btree_copy_ptrs(struct xfs_btree_cur * cur,union xfs_btree_ptr * dst_ptr,const union xfs_btree_ptr * src_ptr,int numptrs)1397 xfs_btree_copy_ptrs(
1398 struct xfs_btree_cur *cur,
1399 union xfs_btree_ptr *dst_ptr,
1400 const union xfs_btree_ptr *src_ptr,
1401 int numptrs)
1402 {
1403 ASSERT(numptrs >= 0);
1404 memcpy(dst_ptr, src_ptr, numptrs * xfs_btree_ptr_len(cur));
1405 }
1406
1407 /*
1408 * Shift keys one index left/right inside a single btree block.
1409 */
1410 STATIC void
xfs_btree_shift_keys(struct xfs_btree_cur * cur,union xfs_btree_key * key,int dir,int numkeys)1411 xfs_btree_shift_keys(
1412 struct xfs_btree_cur *cur,
1413 union xfs_btree_key *key,
1414 int dir,
1415 int numkeys)
1416 {
1417 char *dst_key;
1418
1419 ASSERT(numkeys >= 0);
1420 ASSERT(dir == 1 || dir == -1);
1421
1422 dst_key = (char *)key + (dir * cur->bc_ops->key_len);
1423 memmove(dst_key, key, numkeys * cur->bc_ops->key_len);
1424 }
1425
1426 /*
1427 * Shift records one index left/right inside a single btree block.
1428 */
1429 STATIC void
xfs_btree_shift_recs(struct xfs_btree_cur * cur,union xfs_btree_rec * rec,int dir,int numrecs)1430 xfs_btree_shift_recs(
1431 struct xfs_btree_cur *cur,
1432 union xfs_btree_rec *rec,
1433 int dir,
1434 int numrecs)
1435 {
1436 char *dst_rec;
1437
1438 ASSERT(numrecs >= 0);
1439 ASSERT(dir == 1 || dir == -1);
1440
1441 dst_rec = (char *)rec + (dir * cur->bc_ops->rec_len);
1442 memmove(dst_rec, rec, numrecs * cur->bc_ops->rec_len);
1443 }
1444
1445 /*
1446 * Shift block pointers one index left/right inside a single btree block.
1447 */
1448 STATIC void
xfs_btree_shift_ptrs(struct xfs_btree_cur * cur,union xfs_btree_ptr * ptr,int dir,int numptrs)1449 xfs_btree_shift_ptrs(
1450 struct xfs_btree_cur *cur,
1451 union xfs_btree_ptr *ptr,
1452 int dir,
1453 int numptrs)
1454 {
1455 char *dst_ptr;
1456
1457 ASSERT(numptrs >= 0);
1458 ASSERT(dir == 1 || dir == -1);
1459
1460 dst_ptr = (char *)ptr + (dir * xfs_btree_ptr_len(cur));
1461 memmove(dst_ptr, ptr, numptrs * xfs_btree_ptr_len(cur));
1462 }
1463
1464 /*
1465 * Log key values from the btree block.
1466 */
1467 STATIC void
xfs_btree_log_keys(struct xfs_btree_cur * cur,struct xfs_buf * bp,int first,int last)1468 xfs_btree_log_keys(
1469 struct xfs_btree_cur *cur,
1470 struct xfs_buf *bp,
1471 int first,
1472 int last)
1473 {
1474
1475 if (bp) {
1476 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1477 xfs_trans_log_buf(cur->bc_tp, bp,
1478 xfs_btree_key_offset(cur, first),
1479 xfs_btree_key_offset(cur, last + 1) - 1);
1480 } else {
1481 xfs_trans_log_inode(cur->bc_tp, cur->bc_ino.ip,
1482 xfs_ilog_fbroot(cur->bc_ino.whichfork));
1483 }
1484 }
1485
1486 /*
1487 * Log record values from the btree block.
1488 */
1489 void
xfs_btree_log_recs(struct xfs_btree_cur * cur,struct xfs_buf * bp,int first,int last)1490 xfs_btree_log_recs(
1491 struct xfs_btree_cur *cur,
1492 struct xfs_buf *bp,
1493 int first,
1494 int last)
1495 {
1496
1497 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1498 xfs_trans_log_buf(cur->bc_tp, bp,
1499 xfs_btree_rec_offset(cur, first),
1500 xfs_btree_rec_offset(cur, last + 1) - 1);
1501
1502 }
1503
1504 /*
1505 * Log block pointer fields from a btree block (nonleaf).
1506 */
1507 STATIC void
xfs_btree_log_ptrs(struct xfs_btree_cur * cur,struct xfs_buf * bp,int first,int last)1508 xfs_btree_log_ptrs(
1509 struct xfs_btree_cur *cur, /* btree cursor */
1510 struct xfs_buf *bp, /* buffer containing btree block */
1511 int first, /* index of first pointer to log */
1512 int last) /* index of last pointer to log */
1513 {
1514
1515 if (bp) {
1516 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
1517 int level = xfs_btree_get_level(block);
1518
1519 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1520 xfs_trans_log_buf(cur->bc_tp, bp,
1521 xfs_btree_ptr_offset(cur, first, level),
1522 xfs_btree_ptr_offset(cur, last + 1, level) - 1);
1523 } else {
1524 xfs_trans_log_inode(cur->bc_tp, cur->bc_ino.ip,
1525 xfs_ilog_fbroot(cur->bc_ino.whichfork));
1526 }
1527
1528 }
1529
1530 /*
1531 * Log fields from a btree block header.
1532 */
1533 void
xfs_btree_log_block(struct xfs_btree_cur * cur,struct xfs_buf * bp,int fields)1534 xfs_btree_log_block(
1535 struct xfs_btree_cur *cur, /* btree cursor */
1536 struct xfs_buf *bp, /* buffer containing btree block */
1537 int fields) /* mask of fields: XFS_BB_... */
1538 {
1539 int first; /* first byte offset logged */
1540 int last; /* last byte offset logged */
1541 static const short soffsets[] = { /* table of offsets (short) */
1542 offsetof(struct xfs_btree_block, bb_magic),
1543 offsetof(struct xfs_btree_block, bb_level),
1544 offsetof(struct xfs_btree_block, bb_numrecs),
1545 offsetof(struct xfs_btree_block, bb_u.s.bb_leftsib),
1546 offsetof(struct xfs_btree_block, bb_u.s.bb_rightsib),
1547 offsetof(struct xfs_btree_block, bb_u.s.bb_blkno),
1548 offsetof(struct xfs_btree_block, bb_u.s.bb_lsn),
1549 offsetof(struct xfs_btree_block, bb_u.s.bb_uuid),
1550 offsetof(struct xfs_btree_block, bb_u.s.bb_owner),
1551 offsetof(struct xfs_btree_block, bb_u.s.bb_crc),
1552 XFS_BTREE_SBLOCK_CRC_LEN
1553 };
1554 static const short loffsets[] = { /* table of offsets (long) */
1555 offsetof(struct xfs_btree_block, bb_magic),
1556 offsetof(struct xfs_btree_block, bb_level),
1557 offsetof(struct xfs_btree_block, bb_numrecs),
1558 offsetof(struct xfs_btree_block, bb_u.l.bb_leftsib),
1559 offsetof(struct xfs_btree_block, bb_u.l.bb_rightsib),
1560 offsetof(struct xfs_btree_block, bb_u.l.bb_blkno),
1561 offsetof(struct xfs_btree_block, bb_u.l.bb_lsn),
1562 offsetof(struct xfs_btree_block, bb_u.l.bb_uuid),
1563 offsetof(struct xfs_btree_block, bb_u.l.bb_owner),
1564 offsetof(struct xfs_btree_block, bb_u.l.bb_crc),
1565 offsetof(struct xfs_btree_block, bb_u.l.bb_pad),
1566 XFS_BTREE_LBLOCK_CRC_LEN
1567 };
1568
1569 if (bp) {
1570 int nbits;
1571
1572 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) {
1573 /*
1574 * We don't log the CRC when updating a btree
1575 * block but instead recreate it during log
1576 * recovery. As the log buffers have checksums
1577 * of their own this is safe and avoids logging a crc
1578 * update in a lot of places.
1579 */
1580 if (fields == XFS_BB_ALL_BITS)
1581 fields = XFS_BB_ALL_BITS_CRC;
1582 nbits = XFS_BB_NUM_BITS_CRC;
1583 } else {
1584 nbits = XFS_BB_NUM_BITS;
1585 }
1586 xfs_btree_offsets(fields,
1587 (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
1588 loffsets : soffsets,
1589 nbits, &first, &last);
1590 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1591 xfs_trans_log_buf(cur->bc_tp, bp, first, last);
1592 } else {
1593 xfs_trans_log_inode(cur->bc_tp, cur->bc_ino.ip,
1594 xfs_ilog_fbroot(cur->bc_ino.whichfork));
1595 }
1596 }
1597
1598 /*
1599 * Increment cursor by one record at the level.
1600 * For nonzero levels the leaf-ward information is untouched.
1601 */
1602 int /* error */
xfs_btree_increment(struct xfs_btree_cur * cur,int level,int * stat)1603 xfs_btree_increment(
1604 struct xfs_btree_cur *cur,
1605 int level,
1606 int *stat) /* success/failure */
1607 {
1608 struct xfs_btree_block *block;
1609 union xfs_btree_ptr ptr;
1610 struct xfs_buf *bp;
1611 int error; /* error return value */
1612 int lev;
1613
1614 ASSERT(level < cur->bc_nlevels);
1615
1616 /* Read-ahead to the right at this level. */
1617 xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
1618
1619 /* Get a pointer to the btree block. */
1620 block = xfs_btree_get_block(cur, level, &bp);
1621
1622 #ifdef DEBUG
1623 error = xfs_btree_check_block(cur, block, level, bp);
1624 if (error)
1625 goto error0;
1626 #endif
1627
1628 /* We're done if we remain in the block after the increment. */
1629 if (++cur->bc_ptrs[level] <= xfs_btree_get_numrecs(block))
1630 goto out1;
1631
1632 /* Fail if we just went off the right edge of the tree. */
1633 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1634 if (xfs_btree_ptr_is_null(cur, &ptr))
1635 goto out0;
1636
1637 XFS_BTREE_STATS_INC(cur, increment);
1638
1639 /*
1640 * March up the tree incrementing pointers.
1641 * Stop when we don't go off the right edge of a block.
1642 */
1643 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1644 block = xfs_btree_get_block(cur, lev, &bp);
1645
1646 #ifdef DEBUG
1647 error = xfs_btree_check_block(cur, block, lev, bp);
1648 if (error)
1649 goto error0;
1650 #endif
1651
1652 if (++cur->bc_ptrs[lev] <= xfs_btree_get_numrecs(block))
1653 break;
1654
1655 /* Read-ahead the right block for the next loop. */
1656 xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA);
1657 }
1658
1659 /*
1660 * If we went off the root then we are either seriously
1661 * confused or have the tree root in an inode.
1662 */
1663 if (lev == cur->bc_nlevels) {
1664 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1665 goto out0;
1666 ASSERT(0);
1667 error = -EFSCORRUPTED;
1668 goto error0;
1669 }
1670 ASSERT(lev < cur->bc_nlevels);
1671
1672 /*
1673 * Now walk back down the tree, fixing up the cursor's buffer
1674 * pointers and key numbers.
1675 */
1676 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1677 union xfs_btree_ptr *ptrp;
1678
1679 ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1680 --lev;
1681 error = xfs_btree_read_buf_block(cur, ptrp, 0, &block, &bp);
1682 if (error)
1683 goto error0;
1684
1685 xfs_btree_setbuf(cur, lev, bp);
1686 cur->bc_ptrs[lev] = 1;
1687 }
1688 out1:
1689 *stat = 1;
1690 return 0;
1691
1692 out0:
1693 *stat = 0;
1694 return 0;
1695
1696 error0:
1697 return error;
1698 }
1699
1700 /*
1701 * Decrement cursor by one record at the level.
1702 * For nonzero levels the leaf-ward information is untouched.
1703 */
1704 int /* error */
xfs_btree_decrement(struct xfs_btree_cur * cur,int level,int * stat)1705 xfs_btree_decrement(
1706 struct xfs_btree_cur *cur,
1707 int level,
1708 int *stat) /* success/failure */
1709 {
1710 struct xfs_btree_block *block;
1711 struct xfs_buf *bp;
1712 int error; /* error return value */
1713 int lev;
1714 union xfs_btree_ptr ptr;
1715
1716 ASSERT(level < cur->bc_nlevels);
1717
1718 /* Read-ahead to the left at this level. */
1719 xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA);
1720
1721 /* We're done if we remain in the block after the decrement. */
1722 if (--cur->bc_ptrs[level] > 0)
1723 goto out1;
1724
1725 /* Get a pointer to the btree block. */
1726 block = xfs_btree_get_block(cur, level, &bp);
1727
1728 #ifdef DEBUG
1729 error = xfs_btree_check_block(cur, block, level, bp);
1730 if (error)
1731 goto error0;
1732 #endif
1733
1734 /* Fail if we just went off the left edge of the tree. */
1735 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
1736 if (xfs_btree_ptr_is_null(cur, &ptr))
1737 goto out0;
1738
1739 XFS_BTREE_STATS_INC(cur, decrement);
1740
1741 /*
1742 * March up the tree decrementing pointers.
1743 * Stop when we don't go off the left edge of a block.
1744 */
1745 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1746 if (--cur->bc_ptrs[lev] > 0)
1747 break;
1748 /* Read-ahead the left block for the next loop. */
1749 xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA);
1750 }
1751
1752 /*
1753 * If we went off the root then we are seriously confused.
1754 * or the root of the tree is in an inode.
1755 */
1756 if (lev == cur->bc_nlevels) {
1757 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1758 goto out0;
1759 ASSERT(0);
1760 error = -EFSCORRUPTED;
1761 goto error0;
1762 }
1763 ASSERT(lev < cur->bc_nlevels);
1764
1765 /*
1766 * Now walk back down the tree, fixing up the cursor's buffer
1767 * pointers and key numbers.
1768 */
1769 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1770 union xfs_btree_ptr *ptrp;
1771
1772 ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1773 --lev;
1774 error = xfs_btree_read_buf_block(cur, ptrp, 0, &block, &bp);
1775 if (error)
1776 goto error0;
1777 xfs_btree_setbuf(cur, lev, bp);
1778 cur->bc_ptrs[lev] = xfs_btree_get_numrecs(block);
1779 }
1780 out1:
1781 *stat = 1;
1782 return 0;
1783
1784 out0:
1785 *stat = 0;
1786 return 0;
1787
1788 error0:
1789 return error;
1790 }
1791
1792 int
xfs_btree_lookup_get_block(struct xfs_btree_cur * cur,int level,const union xfs_btree_ptr * pp,struct xfs_btree_block ** blkp)1793 xfs_btree_lookup_get_block(
1794 struct xfs_btree_cur *cur, /* btree cursor */
1795 int level, /* level in the btree */
1796 const union xfs_btree_ptr *pp, /* ptr to btree block */
1797 struct xfs_btree_block **blkp) /* return btree block */
1798 {
1799 struct xfs_buf *bp; /* buffer pointer for btree block */
1800 xfs_daddr_t daddr;
1801 int error = 0;
1802
1803 /* special case the root block if in an inode */
1804 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1805 (level == cur->bc_nlevels - 1)) {
1806 *blkp = xfs_btree_get_iroot(cur);
1807 return 0;
1808 }
1809
1810 /*
1811 * If the old buffer at this level for the disk address we are
1812 * looking for re-use it.
1813 *
1814 * Otherwise throw it away and get a new one.
1815 */
1816 bp = cur->bc_bufs[level];
1817 error = xfs_btree_ptr_to_daddr(cur, pp, &daddr);
1818 if (error)
1819 return error;
1820 if (bp && xfs_buf_daddr(bp) == daddr) {
1821 *blkp = XFS_BUF_TO_BLOCK(bp);
1822 return 0;
1823 }
1824
1825 error = xfs_btree_read_buf_block(cur, pp, 0, blkp, &bp);
1826 if (error)
1827 return error;
1828
1829 /* Check the inode owner since the verifiers don't. */
1830 if (xfs_has_crc(cur->bc_mp) &&
1831 !(cur->bc_ino.flags & XFS_BTCUR_BMBT_INVALID_OWNER) &&
1832 (cur->bc_flags & XFS_BTREE_LONG_PTRS) &&
1833 be64_to_cpu((*blkp)->bb_u.l.bb_owner) !=
1834 cur->bc_ino.ip->i_ino)
1835 goto out_bad;
1836
1837 /* Did we get the level we were looking for? */
1838 if (be16_to_cpu((*blkp)->bb_level) != level)
1839 goto out_bad;
1840
1841 /* Check that internal nodes have at least one record. */
1842 if (level != 0 && be16_to_cpu((*blkp)->bb_numrecs) == 0)
1843 goto out_bad;
1844
1845 xfs_btree_setbuf(cur, level, bp);
1846 return 0;
1847
1848 out_bad:
1849 *blkp = NULL;
1850 xfs_buf_mark_corrupt(bp);
1851 xfs_trans_brelse(cur->bc_tp, bp);
1852 return -EFSCORRUPTED;
1853 }
1854
1855 /*
1856 * Get current search key. For level 0 we don't actually have a key
1857 * structure so we make one up from the record. For all other levels
1858 * we just return the right key.
1859 */
1860 STATIC union xfs_btree_key *
xfs_lookup_get_search_key(struct xfs_btree_cur * cur,int level,int keyno,struct xfs_btree_block * block,union xfs_btree_key * kp)1861 xfs_lookup_get_search_key(
1862 struct xfs_btree_cur *cur,
1863 int level,
1864 int keyno,
1865 struct xfs_btree_block *block,
1866 union xfs_btree_key *kp)
1867 {
1868 if (level == 0) {
1869 cur->bc_ops->init_key_from_rec(kp,
1870 xfs_btree_rec_addr(cur, keyno, block));
1871 return kp;
1872 }
1873
1874 return xfs_btree_key_addr(cur, keyno, block);
1875 }
1876
1877 /*
1878 * Lookup the record. The cursor is made to point to it, based on dir.
1879 * stat is set to 0 if can't find any such record, 1 for success.
1880 */
1881 int /* error */
xfs_btree_lookup(struct xfs_btree_cur * cur,xfs_lookup_t dir,int * stat)1882 xfs_btree_lookup(
1883 struct xfs_btree_cur *cur, /* btree cursor */
1884 xfs_lookup_t dir, /* <=, ==, or >= */
1885 int *stat) /* success/failure */
1886 {
1887 struct xfs_btree_block *block; /* current btree block */
1888 int64_t diff; /* difference for the current key */
1889 int error; /* error return value */
1890 int keyno; /* current key number */
1891 int level; /* level in the btree */
1892 union xfs_btree_ptr *pp; /* ptr to btree block */
1893 union xfs_btree_ptr ptr; /* ptr to btree block */
1894
1895 XFS_BTREE_STATS_INC(cur, lookup);
1896
1897 /* No such thing as a zero-level tree. */
1898 if (XFS_IS_CORRUPT(cur->bc_mp, cur->bc_nlevels == 0))
1899 return -EFSCORRUPTED;
1900
1901 block = NULL;
1902 keyno = 0;
1903
1904 /* initialise start pointer from cursor */
1905 cur->bc_ops->init_ptr_from_cur(cur, &ptr);
1906 pp = &ptr;
1907
1908 /*
1909 * Iterate over each level in the btree, starting at the root.
1910 * For each level above the leaves, find the key we need, based
1911 * on the lookup record, then follow the corresponding block
1912 * pointer down to the next level.
1913 */
1914 for (level = cur->bc_nlevels - 1, diff = 1; level >= 0; level--) {
1915 /* Get the block we need to do the lookup on. */
1916 error = xfs_btree_lookup_get_block(cur, level, pp, &block);
1917 if (error)
1918 goto error0;
1919
1920 if (diff == 0) {
1921 /*
1922 * If we already had a key match at a higher level, we
1923 * know we need to use the first entry in this block.
1924 */
1925 keyno = 1;
1926 } else {
1927 /* Otherwise search this block. Do a binary search. */
1928
1929 int high; /* high entry number */
1930 int low; /* low entry number */
1931
1932 /* Set low and high entry numbers, 1-based. */
1933 low = 1;
1934 high = xfs_btree_get_numrecs(block);
1935 if (!high) {
1936 /* Block is empty, must be an empty leaf. */
1937 if (level != 0 || cur->bc_nlevels != 1) {
1938 XFS_CORRUPTION_ERROR(__func__,
1939 XFS_ERRLEVEL_LOW,
1940 cur->bc_mp, block,
1941 sizeof(*block));
1942 return -EFSCORRUPTED;
1943 }
1944
1945 cur->bc_ptrs[0] = dir != XFS_LOOKUP_LE;
1946 *stat = 0;
1947 return 0;
1948 }
1949
1950 /* Binary search the block. */
1951 while (low <= high) {
1952 union xfs_btree_key key;
1953 union xfs_btree_key *kp;
1954
1955 XFS_BTREE_STATS_INC(cur, compare);
1956
1957 /* keyno is average of low and high. */
1958 keyno = (low + high) >> 1;
1959
1960 /* Get current search key */
1961 kp = xfs_lookup_get_search_key(cur, level,
1962 keyno, block, &key);
1963
1964 /*
1965 * Compute difference to get next direction:
1966 * - less than, move right
1967 * - greater than, move left
1968 * - equal, we're done
1969 */
1970 diff = cur->bc_ops->key_diff(cur, kp);
1971 if (diff < 0)
1972 low = keyno + 1;
1973 else if (diff > 0)
1974 high = keyno - 1;
1975 else
1976 break;
1977 }
1978 }
1979
1980 /*
1981 * If there are more levels, set up for the next level
1982 * by getting the block number and filling in the cursor.
1983 */
1984 if (level > 0) {
1985 /*
1986 * If we moved left, need the previous key number,
1987 * unless there isn't one.
1988 */
1989 if (diff > 0 && --keyno < 1)
1990 keyno = 1;
1991 pp = xfs_btree_ptr_addr(cur, keyno, block);
1992
1993 error = xfs_btree_debug_check_ptr(cur, pp, 0, level);
1994 if (error)
1995 goto error0;
1996
1997 cur->bc_ptrs[level] = keyno;
1998 }
1999 }
2000
2001 /* Done with the search. See if we need to adjust the results. */
2002 if (dir != XFS_LOOKUP_LE && diff < 0) {
2003 keyno++;
2004 /*
2005 * If ge search and we went off the end of the block, but it's
2006 * not the last block, we're in the wrong block.
2007 */
2008 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
2009 if (dir == XFS_LOOKUP_GE &&
2010 keyno > xfs_btree_get_numrecs(block) &&
2011 !xfs_btree_ptr_is_null(cur, &ptr)) {
2012 int i;
2013
2014 cur->bc_ptrs[0] = keyno;
2015 error = xfs_btree_increment(cur, 0, &i);
2016 if (error)
2017 goto error0;
2018 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1))
2019 return -EFSCORRUPTED;
2020 *stat = 1;
2021 return 0;
2022 }
2023 } else if (dir == XFS_LOOKUP_LE && diff > 0)
2024 keyno--;
2025 cur->bc_ptrs[0] = keyno;
2026
2027 /* Return if we succeeded or not. */
2028 if (keyno == 0 || keyno > xfs_btree_get_numrecs(block))
2029 *stat = 0;
2030 else if (dir != XFS_LOOKUP_EQ || diff == 0)
2031 *stat = 1;
2032 else
2033 *stat = 0;
2034 return 0;
2035
2036 error0:
2037 return error;
2038 }
2039
2040 /* Find the high key storage area from a regular key. */
2041 union xfs_btree_key *
xfs_btree_high_key_from_key(struct xfs_btree_cur * cur,union xfs_btree_key * key)2042 xfs_btree_high_key_from_key(
2043 struct xfs_btree_cur *cur,
2044 union xfs_btree_key *key)
2045 {
2046 ASSERT(cur->bc_flags & XFS_BTREE_OVERLAPPING);
2047 return (union xfs_btree_key *)((char *)key +
2048 (cur->bc_ops->key_len / 2));
2049 }
2050
2051 /* Determine the low (and high if overlapped) keys of a leaf block */
2052 STATIC void
xfs_btree_get_leaf_keys(struct xfs_btree_cur * cur,struct xfs_btree_block * block,union xfs_btree_key * key)2053 xfs_btree_get_leaf_keys(
2054 struct xfs_btree_cur *cur,
2055 struct xfs_btree_block *block,
2056 union xfs_btree_key *key)
2057 {
2058 union xfs_btree_key max_hkey;
2059 union xfs_btree_key hkey;
2060 union xfs_btree_rec *rec;
2061 union xfs_btree_key *high;
2062 int n;
2063
2064 rec = xfs_btree_rec_addr(cur, 1, block);
2065 cur->bc_ops->init_key_from_rec(key, rec);
2066
2067 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2068
2069 cur->bc_ops->init_high_key_from_rec(&max_hkey, rec);
2070 for (n = 2; n <= xfs_btree_get_numrecs(block); n++) {
2071 rec = xfs_btree_rec_addr(cur, n, block);
2072 cur->bc_ops->init_high_key_from_rec(&hkey, rec);
2073 if (cur->bc_ops->diff_two_keys(cur, &hkey, &max_hkey)
2074 > 0)
2075 max_hkey = hkey;
2076 }
2077
2078 high = xfs_btree_high_key_from_key(cur, key);
2079 memcpy(high, &max_hkey, cur->bc_ops->key_len / 2);
2080 }
2081 }
2082
2083 /* Determine the low (and high if overlapped) keys of a node block */
2084 STATIC void
xfs_btree_get_node_keys(struct xfs_btree_cur * cur,struct xfs_btree_block * block,union xfs_btree_key * key)2085 xfs_btree_get_node_keys(
2086 struct xfs_btree_cur *cur,
2087 struct xfs_btree_block *block,
2088 union xfs_btree_key *key)
2089 {
2090 union xfs_btree_key *hkey;
2091 union xfs_btree_key *max_hkey;
2092 union xfs_btree_key *high;
2093 int n;
2094
2095 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2096 memcpy(key, xfs_btree_key_addr(cur, 1, block),
2097 cur->bc_ops->key_len / 2);
2098
2099 max_hkey = xfs_btree_high_key_addr(cur, 1, block);
2100 for (n = 2; n <= xfs_btree_get_numrecs(block); n++) {
2101 hkey = xfs_btree_high_key_addr(cur, n, block);
2102 if (cur->bc_ops->diff_two_keys(cur, hkey, max_hkey) > 0)
2103 max_hkey = hkey;
2104 }
2105
2106 high = xfs_btree_high_key_from_key(cur, key);
2107 memcpy(high, max_hkey, cur->bc_ops->key_len / 2);
2108 } else {
2109 memcpy(key, xfs_btree_key_addr(cur, 1, block),
2110 cur->bc_ops->key_len);
2111 }
2112 }
2113
2114 /* Derive the keys for any btree block. */
2115 void
xfs_btree_get_keys(struct xfs_btree_cur * cur,struct xfs_btree_block * block,union xfs_btree_key * key)2116 xfs_btree_get_keys(
2117 struct xfs_btree_cur *cur,
2118 struct xfs_btree_block *block,
2119 union xfs_btree_key *key)
2120 {
2121 if (be16_to_cpu(block->bb_level) == 0)
2122 xfs_btree_get_leaf_keys(cur, block, key);
2123 else
2124 xfs_btree_get_node_keys(cur, block, key);
2125 }
2126
2127 /*
2128 * Decide if we need to update the parent keys of a btree block. For
2129 * a standard btree this is only necessary if we're updating the first
2130 * record/key. For an overlapping btree, we must always update the
2131 * keys because the highest key can be in any of the records or keys
2132 * in the block.
2133 */
2134 static inline bool
xfs_btree_needs_key_update(struct xfs_btree_cur * cur,int ptr)2135 xfs_btree_needs_key_update(
2136 struct xfs_btree_cur *cur,
2137 int ptr)
2138 {
2139 return (cur->bc_flags & XFS_BTREE_OVERLAPPING) || ptr == 1;
2140 }
2141
2142 /*
2143 * Update the low and high parent keys of the given level, progressing
2144 * towards the root. If force_all is false, stop if the keys for a given
2145 * level do not need updating.
2146 */
2147 STATIC int
__xfs_btree_updkeys(struct xfs_btree_cur * cur,int level,struct xfs_btree_block * block,struct xfs_buf * bp0,bool force_all)2148 __xfs_btree_updkeys(
2149 struct xfs_btree_cur *cur,
2150 int level,
2151 struct xfs_btree_block *block,
2152 struct xfs_buf *bp0,
2153 bool force_all)
2154 {
2155 union xfs_btree_key key; /* keys from current level */
2156 union xfs_btree_key *lkey; /* keys from the next level up */
2157 union xfs_btree_key *hkey;
2158 union xfs_btree_key *nlkey; /* keys from the next level up */
2159 union xfs_btree_key *nhkey;
2160 struct xfs_buf *bp;
2161 int ptr;
2162
2163 ASSERT(cur->bc_flags & XFS_BTREE_OVERLAPPING);
2164
2165 /* Exit if there aren't any parent levels to update. */
2166 if (level + 1 >= cur->bc_nlevels)
2167 return 0;
2168
2169 trace_xfs_btree_updkeys(cur, level, bp0);
2170
2171 lkey = &key;
2172 hkey = xfs_btree_high_key_from_key(cur, lkey);
2173 xfs_btree_get_keys(cur, block, lkey);
2174 for (level++; level < cur->bc_nlevels; level++) {
2175 #ifdef DEBUG
2176 int error;
2177 #endif
2178 block = xfs_btree_get_block(cur, level, &bp);
2179 trace_xfs_btree_updkeys(cur, level, bp);
2180 #ifdef DEBUG
2181 error = xfs_btree_check_block(cur, block, level, bp);
2182 if (error)
2183 return error;
2184 #endif
2185 ptr = cur->bc_ptrs[level];
2186 nlkey = xfs_btree_key_addr(cur, ptr, block);
2187 nhkey = xfs_btree_high_key_addr(cur, ptr, block);
2188 if (!force_all &&
2189 !(cur->bc_ops->diff_two_keys(cur, nlkey, lkey) != 0 ||
2190 cur->bc_ops->diff_two_keys(cur, nhkey, hkey) != 0))
2191 break;
2192 xfs_btree_copy_keys(cur, nlkey, lkey, 1);
2193 xfs_btree_log_keys(cur, bp, ptr, ptr);
2194 if (level + 1 >= cur->bc_nlevels)
2195 break;
2196 xfs_btree_get_node_keys(cur, block, lkey);
2197 }
2198
2199 return 0;
2200 }
2201
2202 /* Update all the keys from some level in cursor back to the root. */
2203 STATIC int
xfs_btree_updkeys_force(struct xfs_btree_cur * cur,int level)2204 xfs_btree_updkeys_force(
2205 struct xfs_btree_cur *cur,
2206 int level)
2207 {
2208 struct xfs_buf *bp;
2209 struct xfs_btree_block *block;
2210
2211 block = xfs_btree_get_block(cur, level, &bp);
2212 return __xfs_btree_updkeys(cur, level, block, bp, true);
2213 }
2214
2215 /*
2216 * Update the parent keys of the given level, progressing towards the root.
2217 */
2218 STATIC int
xfs_btree_update_keys(struct xfs_btree_cur * cur,int level)2219 xfs_btree_update_keys(
2220 struct xfs_btree_cur *cur,
2221 int level)
2222 {
2223 struct xfs_btree_block *block;
2224 struct xfs_buf *bp;
2225 union xfs_btree_key *kp;
2226 union xfs_btree_key key;
2227 int ptr;
2228
2229 ASSERT(level >= 0);
2230
2231 block = xfs_btree_get_block(cur, level, &bp);
2232 if (cur->bc_flags & XFS_BTREE_OVERLAPPING)
2233 return __xfs_btree_updkeys(cur, level, block, bp, false);
2234
2235 /*
2236 * Go up the tree from this level toward the root.
2237 * At each level, update the key value to the value input.
2238 * Stop when we reach a level where the cursor isn't pointing
2239 * at the first entry in the block.
2240 */
2241 xfs_btree_get_keys(cur, block, &key);
2242 for (level++, ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) {
2243 #ifdef DEBUG
2244 int error;
2245 #endif
2246 block = xfs_btree_get_block(cur, level, &bp);
2247 #ifdef DEBUG
2248 error = xfs_btree_check_block(cur, block, level, bp);
2249 if (error)
2250 return error;
2251 #endif
2252 ptr = cur->bc_ptrs[level];
2253 kp = xfs_btree_key_addr(cur, ptr, block);
2254 xfs_btree_copy_keys(cur, kp, &key, 1);
2255 xfs_btree_log_keys(cur, bp, ptr, ptr);
2256 }
2257
2258 return 0;
2259 }
2260
2261 /*
2262 * Update the record referred to by cur to the value in the
2263 * given record. This either works (return 0) or gets an
2264 * EFSCORRUPTED error.
2265 */
2266 int
xfs_btree_update(struct xfs_btree_cur * cur,union xfs_btree_rec * rec)2267 xfs_btree_update(
2268 struct xfs_btree_cur *cur,
2269 union xfs_btree_rec *rec)
2270 {
2271 struct xfs_btree_block *block;
2272 struct xfs_buf *bp;
2273 int error;
2274 int ptr;
2275 union xfs_btree_rec *rp;
2276
2277 /* Pick up the current block. */
2278 block = xfs_btree_get_block(cur, 0, &bp);
2279
2280 #ifdef DEBUG
2281 error = xfs_btree_check_block(cur, block, 0, bp);
2282 if (error)
2283 goto error0;
2284 #endif
2285 /* Get the address of the rec to be updated. */
2286 ptr = cur->bc_ptrs[0];
2287 rp = xfs_btree_rec_addr(cur, ptr, block);
2288
2289 /* Fill in the new contents and log them. */
2290 xfs_btree_copy_recs(cur, rp, rec, 1);
2291 xfs_btree_log_recs(cur, bp, ptr, ptr);
2292
2293 /*
2294 * If we are tracking the last record in the tree and
2295 * we are at the far right edge of the tree, update it.
2296 */
2297 if (xfs_btree_is_lastrec(cur, block, 0)) {
2298 cur->bc_ops->update_lastrec(cur, block, rec,
2299 ptr, LASTREC_UPDATE);
2300 }
2301
2302 /* Pass new key value up to our parent. */
2303 if (xfs_btree_needs_key_update(cur, ptr)) {
2304 error = xfs_btree_update_keys(cur, 0);
2305 if (error)
2306 goto error0;
2307 }
2308
2309 return 0;
2310
2311 error0:
2312 return error;
2313 }
2314
2315 /*
2316 * Move 1 record left from cur/level if possible.
2317 * Update cur to reflect the new path.
2318 */
2319 STATIC int /* error */
xfs_btree_lshift(struct xfs_btree_cur * cur,int level,int * stat)2320 xfs_btree_lshift(
2321 struct xfs_btree_cur *cur,
2322 int level,
2323 int *stat) /* success/failure */
2324 {
2325 struct xfs_buf *lbp; /* left buffer pointer */
2326 struct xfs_btree_block *left; /* left btree block */
2327 int lrecs; /* left record count */
2328 struct xfs_buf *rbp; /* right buffer pointer */
2329 struct xfs_btree_block *right; /* right btree block */
2330 struct xfs_btree_cur *tcur; /* temporary btree cursor */
2331 int rrecs; /* right record count */
2332 union xfs_btree_ptr lptr; /* left btree pointer */
2333 union xfs_btree_key *rkp = NULL; /* right btree key */
2334 union xfs_btree_ptr *rpp = NULL; /* right address pointer */
2335 union xfs_btree_rec *rrp = NULL; /* right record pointer */
2336 int error; /* error return value */
2337 int i;
2338
2339 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2340 level == cur->bc_nlevels - 1)
2341 goto out0;
2342
2343 /* Set up variables for this block as "right". */
2344 right = xfs_btree_get_block(cur, level, &rbp);
2345
2346 #ifdef DEBUG
2347 error = xfs_btree_check_block(cur, right, level, rbp);
2348 if (error)
2349 goto error0;
2350 #endif
2351
2352 /* If we've got no left sibling then we can't shift an entry left. */
2353 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2354 if (xfs_btree_ptr_is_null(cur, &lptr))
2355 goto out0;
2356
2357 /*
2358 * If the cursor entry is the one that would be moved, don't
2359 * do it... it's too complicated.
2360 */
2361 if (cur->bc_ptrs[level] <= 1)
2362 goto out0;
2363
2364 /* Set up the left neighbor as "left". */
2365 error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
2366 if (error)
2367 goto error0;
2368
2369 /* If it's full, it can't take another entry. */
2370 lrecs = xfs_btree_get_numrecs(left);
2371 if (lrecs == cur->bc_ops->get_maxrecs(cur, level))
2372 goto out0;
2373
2374 rrecs = xfs_btree_get_numrecs(right);
2375
2376 /*
2377 * We add one entry to the left side and remove one for the right side.
2378 * Account for it here, the changes will be updated on disk and logged
2379 * later.
2380 */
2381 lrecs++;
2382 rrecs--;
2383
2384 XFS_BTREE_STATS_INC(cur, lshift);
2385 XFS_BTREE_STATS_ADD(cur, moves, 1);
2386
2387 /*
2388 * If non-leaf, copy a key and a ptr to the left block.
2389 * Log the changes to the left block.
2390 */
2391 if (level > 0) {
2392 /* It's a non-leaf. Move keys and pointers. */
2393 union xfs_btree_key *lkp; /* left btree key */
2394 union xfs_btree_ptr *lpp; /* left address pointer */
2395
2396 lkp = xfs_btree_key_addr(cur, lrecs, left);
2397 rkp = xfs_btree_key_addr(cur, 1, right);
2398
2399 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2400 rpp = xfs_btree_ptr_addr(cur, 1, right);
2401
2402 error = xfs_btree_debug_check_ptr(cur, rpp, 0, level);
2403 if (error)
2404 goto error0;
2405
2406 xfs_btree_copy_keys(cur, lkp, rkp, 1);
2407 xfs_btree_copy_ptrs(cur, lpp, rpp, 1);
2408
2409 xfs_btree_log_keys(cur, lbp, lrecs, lrecs);
2410 xfs_btree_log_ptrs(cur, lbp, lrecs, lrecs);
2411
2412 ASSERT(cur->bc_ops->keys_inorder(cur,
2413 xfs_btree_key_addr(cur, lrecs - 1, left), lkp));
2414 } else {
2415 /* It's a leaf. Move records. */
2416 union xfs_btree_rec *lrp; /* left record pointer */
2417
2418 lrp = xfs_btree_rec_addr(cur, lrecs, left);
2419 rrp = xfs_btree_rec_addr(cur, 1, right);
2420
2421 xfs_btree_copy_recs(cur, lrp, rrp, 1);
2422 xfs_btree_log_recs(cur, lbp, lrecs, lrecs);
2423
2424 ASSERT(cur->bc_ops->recs_inorder(cur,
2425 xfs_btree_rec_addr(cur, lrecs - 1, left), lrp));
2426 }
2427
2428 xfs_btree_set_numrecs(left, lrecs);
2429 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2430
2431 xfs_btree_set_numrecs(right, rrecs);
2432 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2433
2434 /*
2435 * Slide the contents of right down one entry.
2436 */
2437 XFS_BTREE_STATS_ADD(cur, moves, rrecs - 1);
2438 if (level > 0) {
2439 /* It's a nonleaf. operate on keys and ptrs */
2440 for (i = 0; i < rrecs; i++) {
2441 error = xfs_btree_debug_check_ptr(cur, rpp, i + 1, level);
2442 if (error)
2443 goto error0;
2444 }
2445
2446 xfs_btree_shift_keys(cur,
2447 xfs_btree_key_addr(cur, 2, right),
2448 -1, rrecs);
2449 xfs_btree_shift_ptrs(cur,
2450 xfs_btree_ptr_addr(cur, 2, right),
2451 -1, rrecs);
2452
2453 xfs_btree_log_keys(cur, rbp, 1, rrecs);
2454 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2455 } else {
2456 /* It's a leaf. operate on records */
2457 xfs_btree_shift_recs(cur,
2458 xfs_btree_rec_addr(cur, 2, right),
2459 -1, rrecs);
2460 xfs_btree_log_recs(cur, rbp, 1, rrecs);
2461 }
2462
2463 /*
2464 * Using a temporary cursor, update the parent key values of the
2465 * block on the left.
2466 */
2467 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2468 error = xfs_btree_dup_cursor(cur, &tcur);
2469 if (error)
2470 goto error0;
2471 i = xfs_btree_firstrec(tcur, level);
2472 if (XFS_IS_CORRUPT(tcur->bc_mp, i != 1)) {
2473 error = -EFSCORRUPTED;
2474 goto error0;
2475 }
2476
2477 error = xfs_btree_decrement(tcur, level, &i);
2478 if (error)
2479 goto error1;
2480
2481 /* Update the parent high keys of the left block, if needed. */
2482 error = xfs_btree_update_keys(tcur, level);
2483 if (error)
2484 goto error1;
2485
2486 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
2487 }
2488
2489 /* Update the parent keys of the right block. */
2490 error = xfs_btree_update_keys(cur, level);
2491 if (error)
2492 goto error0;
2493
2494 /* Slide the cursor value left one. */
2495 cur->bc_ptrs[level]--;
2496
2497 *stat = 1;
2498 return 0;
2499
2500 out0:
2501 *stat = 0;
2502 return 0;
2503
2504 error0:
2505 return error;
2506
2507 error1:
2508 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
2509 return error;
2510 }
2511
2512 /*
2513 * Move 1 record right from cur/level if possible.
2514 * Update cur to reflect the new path.
2515 */
2516 STATIC int /* error */
xfs_btree_rshift(struct xfs_btree_cur * cur,int level,int * stat)2517 xfs_btree_rshift(
2518 struct xfs_btree_cur *cur,
2519 int level,
2520 int *stat) /* success/failure */
2521 {
2522 struct xfs_buf *lbp; /* left buffer pointer */
2523 struct xfs_btree_block *left; /* left btree block */
2524 struct xfs_buf *rbp; /* right buffer pointer */
2525 struct xfs_btree_block *right; /* right btree block */
2526 struct xfs_btree_cur *tcur; /* temporary btree cursor */
2527 union xfs_btree_ptr rptr; /* right block pointer */
2528 union xfs_btree_key *rkp; /* right btree key */
2529 int rrecs; /* right record count */
2530 int lrecs; /* left record count */
2531 int error; /* error return value */
2532 int i; /* loop counter */
2533
2534 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2535 (level == cur->bc_nlevels - 1))
2536 goto out0;
2537
2538 /* Set up variables for this block as "left". */
2539 left = xfs_btree_get_block(cur, level, &lbp);
2540
2541 #ifdef DEBUG
2542 error = xfs_btree_check_block(cur, left, level, lbp);
2543 if (error)
2544 goto error0;
2545 #endif
2546
2547 /* If we've got no right sibling then we can't shift an entry right. */
2548 xfs_btree_get_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2549 if (xfs_btree_ptr_is_null(cur, &rptr))
2550 goto out0;
2551
2552 /*
2553 * If the cursor entry is the one that would be moved, don't
2554 * do it... it's too complicated.
2555 */
2556 lrecs = xfs_btree_get_numrecs(left);
2557 if (cur->bc_ptrs[level] >= lrecs)
2558 goto out0;
2559
2560 /* Set up the right neighbor as "right". */
2561 error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
2562 if (error)
2563 goto error0;
2564
2565 /* If it's full, it can't take another entry. */
2566 rrecs = xfs_btree_get_numrecs(right);
2567 if (rrecs == cur->bc_ops->get_maxrecs(cur, level))
2568 goto out0;
2569
2570 XFS_BTREE_STATS_INC(cur, rshift);
2571 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2572
2573 /*
2574 * Make a hole at the start of the right neighbor block, then
2575 * copy the last left block entry to the hole.
2576 */
2577 if (level > 0) {
2578 /* It's a nonleaf. make a hole in the keys and ptrs */
2579 union xfs_btree_key *lkp;
2580 union xfs_btree_ptr *lpp;
2581 union xfs_btree_ptr *rpp;
2582
2583 lkp = xfs_btree_key_addr(cur, lrecs, left);
2584 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2585 rkp = xfs_btree_key_addr(cur, 1, right);
2586 rpp = xfs_btree_ptr_addr(cur, 1, right);
2587
2588 for (i = rrecs - 1; i >= 0; i--) {
2589 error = xfs_btree_debug_check_ptr(cur, rpp, i, level);
2590 if (error)
2591 goto error0;
2592 }
2593
2594 xfs_btree_shift_keys(cur, rkp, 1, rrecs);
2595 xfs_btree_shift_ptrs(cur, rpp, 1, rrecs);
2596
2597 error = xfs_btree_debug_check_ptr(cur, lpp, 0, level);
2598 if (error)
2599 goto error0;
2600
2601 /* Now put the new data in, and log it. */
2602 xfs_btree_copy_keys(cur, rkp, lkp, 1);
2603 xfs_btree_copy_ptrs(cur, rpp, lpp, 1);
2604
2605 xfs_btree_log_keys(cur, rbp, 1, rrecs + 1);
2606 xfs_btree_log_ptrs(cur, rbp, 1, rrecs + 1);
2607
2608 ASSERT(cur->bc_ops->keys_inorder(cur, rkp,
2609 xfs_btree_key_addr(cur, 2, right)));
2610 } else {
2611 /* It's a leaf. make a hole in the records */
2612 union xfs_btree_rec *lrp;
2613 union xfs_btree_rec *rrp;
2614
2615 lrp = xfs_btree_rec_addr(cur, lrecs, left);
2616 rrp = xfs_btree_rec_addr(cur, 1, right);
2617
2618 xfs_btree_shift_recs(cur, rrp, 1, rrecs);
2619
2620 /* Now put the new data in, and log it. */
2621 xfs_btree_copy_recs(cur, rrp, lrp, 1);
2622 xfs_btree_log_recs(cur, rbp, 1, rrecs + 1);
2623 }
2624
2625 /*
2626 * Decrement and log left's numrecs, bump and log right's numrecs.
2627 */
2628 xfs_btree_set_numrecs(left, --lrecs);
2629 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2630
2631 xfs_btree_set_numrecs(right, ++rrecs);
2632 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2633
2634 /*
2635 * Using a temporary cursor, update the parent key values of the
2636 * block on the right.
2637 */
2638 error = xfs_btree_dup_cursor(cur, &tcur);
2639 if (error)
2640 goto error0;
2641 i = xfs_btree_lastrec(tcur, level);
2642 if (XFS_IS_CORRUPT(tcur->bc_mp, i != 1)) {
2643 error = -EFSCORRUPTED;
2644 goto error0;
2645 }
2646
2647 error = xfs_btree_increment(tcur, level, &i);
2648 if (error)
2649 goto error1;
2650
2651 /* Update the parent high keys of the left block, if needed. */
2652 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2653 error = xfs_btree_update_keys(cur, level);
2654 if (error)
2655 goto error1;
2656 }
2657
2658 /* Update the parent keys of the right block. */
2659 error = xfs_btree_update_keys(tcur, level);
2660 if (error)
2661 goto error1;
2662
2663 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
2664
2665 *stat = 1;
2666 return 0;
2667
2668 out0:
2669 *stat = 0;
2670 return 0;
2671
2672 error0:
2673 return error;
2674
2675 error1:
2676 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
2677 return error;
2678 }
2679
2680 /*
2681 * Split cur/level block in half.
2682 * Return new block number and the key to its first
2683 * record (to be inserted into parent).
2684 */
2685 STATIC int /* error */
__xfs_btree_split(struct xfs_btree_cur * cur,int level,union xfs_btree_ptr * ptrp,union xfs_btree_key * key,struct xfs_btree_cur ** curp,int * stat)2686 __xfs_btree_split(
2687 struct xfs_btree_cur *cur,
2688 int level,
2689 union xfs_btree_ptr *ptrp,
2690 union xfs_btree_key *key,
2691 struct xfs_btree_cur **curp,
2692 int *stat) /* success/failure */
2693 {
2694 union xfs_btree_ptr lptr; /* left sibling block ptr */
2695 struct xfs_buf *lbp; /* left buffer pointer */
2696 struct xfs_btree_block *left; /* left btree block */
2697 union xfs_btree_ptr rptr; /* right sibling block ptr */
2698 struct xfs_buf *rbp; /* right buffer pointer */
2699 struct xfs_btree_block *right; /* right btree block */
2700 union xfs_btree_ptr rrptr; /* right-right sibling ptr */
2701 struct xfs_buf *rrbp; /* right-right buffer pointer */
2702 struct xfs_btree_block *rrblock; /* right-right btree block */
2703 int lrecs;
2704 int rrecs;
2705 int src_index;
2706 int error; /* error return value */
2707 int i;
2708
2709 XFS_BTREE_STATS_INC(cur, split);
2710
2711 /* Set up left block (current one). */
2712 left = xfs_btree_get_block(cur, level, &lbp);
2713
2714 #ifdef DEBUG
2715 error = xfs_btree_check_block(cur, left, level, lbp);
2716 if (error)
2717 goto error0;
2718 #endif
2719
2720 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2721
2722 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2723 error = cur->bc_ops->alloc_block(cur, &lptr, &rptr, stat);
2724 if (error)
2725 goto error0;
2726 if (*stat == 0)
2727 goto out0;
2728 XFS_BTREE_STATS_INC(cur, alloc);
2729
2730 /* Set up the new block as "right". */
2731 error = xfs_btree_get_buf_block(cur, &rptr, &right, &rbp);
2732 if (error)
2733 goto error0;
2734
2735 /* Fill in the btree header for the new right block. */
2736 xfs_btree_init_block_cur(cur, rbp, xfs_btree_get_level(left), 0);
2737
2738 /*
2739 * Split the entries between the old and the new block evenly.
2740 * Make sure that if there's an odd number of entries now, that
2741 * each new block will have the same number of entries.
2742 */
2743 lrecs = xfs_btree_get_numrecs(left);
2744 rrecs = lrecs / 2;
2745 if ((lrecs & 1) && cur->bc_ptrs[level] <= rrecs + 1)
2746 rrecs++;
2747 src_index = (lrecs - rrecs + 1);
2748
2749 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2750
2751 /* Adjust numrecs for the later get_*_keys() calls. */
2752 lrecs -= rrecs;
2753 xfs_btree_set_numrecs(left, lrecs);
2754 xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs);
2755
2756 /*
2757 * Copy btree block entries from the left block over to the
2758 * new block, the right. Update the right block and log the
2759 * changes.
2760 */
2761 if (level > 0) {
2762 /* It's a non-leaf. Move keys and pointers. */
2763 union xfs_btree_key *lkp; /* left btree key */
2764 union xfs_btree_ptr *lpp; /* left address pointer */
2765 union xfs_btree_key *rkp; /* right btree key */
2766 union xfs_btree_ptr *rpp; /* right address pointer */
2767
2768 lkp = xfs_btree_key_addr(cur, src_index, left);
2769 lpp = xfs_btree_ptr_addr(cur, src_index, left);
2770 rkp = xfs_btree_key_addr(cur, 1, right);
2771 rpp = xfs_btree_ptr_addr(cur, 1, right);
2772
2773 for (i = src_index; i < rrecs; i++) {
2774 error = xfs_btree_debug_check_ptr(cur, lpp, i, level);
2775 if (error)
2776 goto error0;
2777 }
2778
2779 /* Copy the keys & pointers to the new block. */
2780 xfs_btree_copy_keys(cur, rkp, lkp, rrecs);
2781 xfs_btree_copy_ptrs(cur, rpp, lpp, rrecs);
2782
2783 xfs_btree_log_keys(cur, rbp, 1, rrecs);
2784 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2785
2786 /* Stash the keys of the new block for later insertion. */
2787 xfs_btree_get_node_keys(cur, right, key);
2788 } else {
2789 /* It's a leaf. Move records. */
2790 union xfs_btree_rec *lrp; /* left record pointer */
2791 union xfs_btree_rec *rrp; /* right record pointer */
2792
2793 lrp = xfs_btree_rec_addr(cur, src_index, left);
2794 rrp = xfs_btree_rec_addr(cur, 1, right);
2795
2796 /* Copy records to the new block. */
2797 xfs_btree_copy_recs(cur, rrp, lrp, rrecs);
2798 xfs_btree_log_recs(cur, rbp, 1, rrecs);
2799
2800 /* Stash the keys of the new block for later insertion. */
2801 xfs_btree_get_leaf_keys(cur, right, key);
2802 }
2803
2804 /*
2805 * Find the left block number by looking in the buffer.
2806 * Adjust sibling pointers.
2807 */
2808 xfs_btree_get_sibling(cur, left, &rrptr, XFS_BB_RIGHTSIB);
2809 xfs_btree_set_sibling(cur, right, &rrptr, XFS_BB_RIGHTSIB);
2810 xfs_btree_set_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2811 xfs_btree_set_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2812
2813 xfs_btree_log_block(cur, rbp, XFS_BB_ALL_BITS);
2814 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
2815
2816 /*
2817 * If there's a block to the new block's right, make that block
2818 * point back to right instead of to left.
2819 */
2820 if (!xfs_btree_ptr_is_null(cur, &rrptr)) {
2821 error = xfs_btree_read_buf_block(cur, &rrptr,
2822 0, &rrblock, &rrbp);
2823 if (error)
2824 goto error0;
2825 xfs_btree_set_sibling(cur, rrblock, &rptr, XFS_BB_LEFTSIB);
2826 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
2827 }
2828
2829 /* Update the parent high keys of the left block, if needed. */
2830 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2831 error = xfs_btree_update_keys(cur, level);
2832 if (error)
2833 goto error0;
2834 }
2835
2836 /*
2837 * If the cursor is really in the right block, move it there.
2838 * If it's just pointing past the last entry in left, then we'll
2839 * insert there, so don't change anything in that case.
2840 */
2841 if (cur->bc_ptrs[level] > lrecs + 1) {
2842 xfs_btree_setbuf(cur, level, rbp);
2843 cur->bc_ptrs[level] -= lrecs;
2844 }
2845 /*
2846 * If there are more levels, we'll need another cursor which refers
2847 * the right block, no matter where this cursor was.
2848 */
2849 if (level + 1 < cur->bc_nlevels) {
2850 error = xfs_btree_dup_cursor(cur, curp);
2851 if (error)
2852 goto error0;
2853 (*curp)->bc_ptrs[level + 1]++;
2854 }
2855 *ptrp = rptr;
2856 *stat = 1;
2857 return 0;
2858 out0:
2859 *stat = 0;
2860 return 0;
2861
2862 error0:
2863 return error;
2864 }
2865
2866 struct xfs_btree_split_args {
2867 struct xfs_btree_cur *cur;
2868 int level;
2869 union xfs_btree_ptr *ptrp;
2870 union xfs_btree_key *key;
2871 struct xfs_btree_cur **curp;
2872 int *stat; /* success/failure */
2873 int result;
2874 bool kswapd; /* allocation in kswapd context */
2875 struct completion *done;
2876 struct work_struct work;
2877 };
2878
2879 /*
2880 * Stack switching interfaces for allocation
2881 */
2882 static void
xfs_btree_split_worker(struct work_struct * work)2883 xfs_btree_split_worker(
2884 struct work_struct *work)
2885 {
2886 struct xfs_btree_split_args *args = container_of(work,
2887 struct xfs_btree_split_args, work);
2888 unsigned long pflags;
2889 unsigned long new_pflags = 0;
2890
2891 /*
2892 * we are in a transaction context here, but may also be doing work
2893 * in kswapd context, and hence we may need to inherit that state
2894 * temporarily to ensure that we don't block waiting for memory reclaim
2895 * in any way.
2896 */
2897 if (args->kswapd)
2898 new_pflags |= PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD;
2899
2900 current_set_flags_nested(&pflags, new_pflags);
2901 xfs_trans_set_context(args->cur->bc_tp);
2902
2903 args->result = __xfs_btree_split(args->cur, args->level, args->ptrp,
2904 args->key, args->curp, args->stat);
2905
2906 xfs_trans_clear_context(args->cur->bc_tp);
2907 current_restore_flags_nested(&pflags, new_pflags);
2908
2909 /*
2910 * Do not access args after complete() has run here. We don't own args
2911 * and the owner may run and free args before we return here.
2912 */
2913 complete(args->done);
2914
2915 }
2916
2917 /*
2918 * BMBT split requests often come in with little stack to work on. Push
2919 * them off to a worker thread so there is lots of stack to use. For the other
2920 * btree types, just call directly to avoid the context switch overhead here.
2921 */
2922 STATIC int /* error */
xfs_btree_split(struct xfs_btree_cur * cur,int level,union xfs_btree_ptr * ptrp,union xfs_btree_key * key,struct xfs_btree_cur ** curp,int * stat)2923 xfs_btree_split(
2924 struct xfs_btree_cur *cur,
2925 int level,
2926 union xfs_btree_ptr *ptrp,
2927 union xfs_btree_key *key,
2928 struct xfs_btree_cur **curp,
2929 int *stat) /* success/failure */
2930 {
2931 struct xfs_btree_split_args args;
2932 DECLARE_COMPLETION_ONSTACK(done);
2933
2934 if (cur->bc_btnum != XFS_BTNUM_BMAP)
2935 return __xfs_btree_split(cur, level, ptrp, key, curp, stat);
2936
2937 args.cur = cur;
2938 args.level = level;
2939 args.ptrp = ptrp;
2940 args.key = key;
2941 args.curp = curp;
2942 args.stat = stat;
2943 args.done = &done;
2944 args.kswapd = current_is_kswapd();
2945 INIT_WORK_ONSTACK(&args.work, xfs_btree_split_worker);
2946 queue_work(xfs_alloc_wq, &args.work);
2947 wait_for_completion(&done);
2948 destroy_work_on_stack(&args.work);
2949 return args.result;
2950 }
2951
2952
2953 /*
2954 * Copy the old inode root contents into a real block and make the
2955 * broot point to it.
2956 */
2957 int /* error */
xfs_btree_new_iroot(struct xfs_btree_cur * cur,int * logflags,int * stat)2958 xfs_btree_new_iroot(
2959 struct xfs_btree_cur *cur, /* btree cursor */
2960 int *logflags, /* logging flags for inode */
2961 int *stat) /* return status - 0 fail */
2962 {
2963 struct xfs_buf *cbp; /* buffer for cblock */
2964 struct xfs_btree_block *block; /* btree block */
2965 struct xfs_btree_block *cblock; /* child btree block */
2966 union xfs_btree_key *ckp; /* child key pointer */
2967 union xfs_btree_ptr *cpp; /* child ptr pointer */
2968 union xfs_btree_key *kp; /* pointer to btree key */
2969 union xfs_btree_ptr *pp; /* pointer to block addr */
2970 union xfs_btree_ptr nptr; /* new block addr */
2971 int level; /* btree level */
2972 int error; /* error return code */
2973 int i; /* loop counter */
2974
2975 XFS_BTREE_STATS_INC(cur, newroot);
2976
2977 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
2978
2979 level = cur->bc_nlevels - 1;
2980
2981 block = xfs_btree_get_iroot(cur);
2982 pp = xfs_btree_ptr_addr(cur, 1, block);
2983
2984 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2985 error = cur->bc_ops->alloc_block(cur, pp, &nptr, stat);
2986 if (error)
2987 goto error0;
2988 if (*stat == 0)
2989 return 0;
2990
2991 XFS_BTREE_STATS_INC(cur, alloc);
2992
2993 /* Copy the root into a real block. */
2994 error = xfs_btree_get_buf_block(cur, &nptr, &cblock, &cbp);
2995 if (error)
2996 goto error0;
2997
2998 /*
2999 * we can't just memcpy() the root in for CRC enabled btree blocks.
3000 * In that case have to also ensure the blkno remains correct
3001 */
3002 memcpy(cblock, block, xfs_btree_block_len(cur));
3003 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) {
3004 __be64 bno = cpu_to_be64(xfs_buf_daddr(cbp));
3005 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
3006 cblock->bb_u.l.bb_blkno = bno;
3007 else
3008 cblock->bb_u.s.bb_blkno = bno;
3009 }
3010
3011 be16_add_cpu(&block->bb_level, 1);
3012 xfs_btree_set_numrecs(block, 1);
3013 cur->bc_nlevels++;
3014 cur->bc_ptrs[level + 1] = 1;
3015
3016 kp = xfs_btree_key_addr(cur, 1, block);
3017 ckp = xfs_btree_key_addr(cur, 1, cblock);
3018 xfs_btree_copy_keys(cur, ckp, kp, xfs_btree_get_numrecs(cblock));
3019
3020 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
3021 for (i = 0; i < be16_to_cpu(cblock->bb_numrecs); i++) {
3022 error = xfs_btree_debug_check_ptr(cur, pp, i, level);
3023 if (error)
3024 goto error0;
3025 }
3026
3027 xfs_btree_copy_ptrs(cur, cpp, pp, xfs_btree_get_numrecs(cblock));
3028
3029 error = xfs_btree_debug_check_ptr(cur, &nptr, 0, level);
3030 if (error)
3031 goto error0;
3032
3033 xfs_btree_copy_ptrs(cur, pp, &nptr, 1);
3034
3035 xfs_iroot_realloc(cur->bc_ino.ip,
3036 1 - xfs_btree_get_numrecs(cblock),
3037 cur->bc_ino.whichfork);
3038
3039 xfs_btree_setbuf(cur, level, cbp);
3040
3041 /*
3042 * Do all this logging at the end so that
3043 * the root is at the right level.
3044 */
3045 xfs_btree_log_block(cur, cbp, XFS_BB_ALL_BITS);
3046 xfs_btree_log_keys(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
3047 xfs_btree_log_ptrs(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
3048
3049 *logflags |=
3050 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_ino.whichfork);
3051 *stat = 1;
3052 return 0;
3053 error0:
3054 return error;
3055 }
3056
3057 /*
3058 * Allocate a new root block, fill it in.
3059 */
3060 STATIC int /* error */
xfs_btree_new_root(struct xfs_btree_cur * cur,int * stat)3061 xfs_btree_new_root(
3062 struct xfs_btree_cur *cur, /* btree cursor */
3063 int *stat) /* success/failure */
3064 {
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;
3077
3078 XFS_BTREE_STATS_INC(cur, newroot);
3079
3080 /* initialise our start point from the cursor */
3081 cur->bc_ops->init_ptr_from_cur(cur, &rptr);
3082
3083 /* Allocate the new block. If we can't do it, we're toast. Give up. */
3084 error = cur->bc_ops->alloc_block(cur, &rptr, &lptr, stat);
3085 if (error)
3086 goto error0;
3087 if (*stat == 0)
3088 goto out0;
3089 XFS_BTREE_STATS_INC(cur, alloc);
3090
3091 /* Set up the new block. */
3092 error = xfs_btree_get_buf_block(cur, &lptr, &new, &nbp);
3093 if (error)
3094 goto error0;
3095
3096 /* Set the root in the holding structure increasing the level by 1. */
3097 cur->bc_ops->set_root(cur, &lptr, 1);
3098
3099 /*
3100 * At the previous root level there are now two blocks: the old root,
3101 * and the new block generated when it was split. We don't know which
3102 * one the cursor is pointing at, so we set up variables "left" and
3103 * "right" for each case.
3104 */
3105 block = xfs_btree_get_block(cur, cur->bc_nlevels - 1, &bp);
3106
3107 #ifdef DEBUG
3108 error = xfs_btree_check_block(cur, block, cur->bc_nlevels - 1, bp);
3109 if (error)
3110 goto error0;
3111 #endif
3112
3113 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
3114 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
3115 /* Our block is left, pick up the right block. */
3116 lbp = bp;
3117 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
3118 left = block;
3119 error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
3120 if (error)
3121 goto error0;
3122 bp = rbp;
3123 nptr = 1;
3124 } else {
3125 /* Our block is right, pick up the left block. */
3126 rbp = bp;
3127 xfs_btree_buf_to_ptr(cur, rbp, &rptr);
3128 right = block;
3129 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
3130 error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
3131 if (error)
3132 goto error0;
3133 bp = lbp;
3134 nptr = 2;
3135 }
3136
3137 /* Fill in the new block's btree header and log it. */
3138 xfs_btree_init_block_cur(cur, nbp, cur->bc_nlevels, 2);
3139 xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS);
3140 ASSERT(!xfs_btree_ptr_is_null(cur, &lptr) &&
3141 !xfs_btree_ptr_is_null(cur, &rptr));
3142
3143 /* Fill in the key data in the new root. */
3144 if (xfs_btree_get_level(left) > 0) {
3145 /*
3146 * Get the keys for the left block's keys and put them directly
3147 * in the parent block. Do the same for the right block.
3148 */
3149 xfs_btree_get_node_keys(cur, left,
3150 xfs_btree_key_addr(cur, 1, new));
3151 xfs_btree_get_node_keys(cur, right,
3152 xfs_btree_key_addr(cur, 2, new));
3153 } else {
3154 /*
3155 * Get the keys for the left block's records and put them
3156 * directly in the parent block. Do the same for the right
3157 * block.
3158 */
3159 xfs_btree_get_leaf_keys(cur, left,
3160 xfs_btree_key_addr(cur, 1, new));
3161 xfs_btree_get_leaf_keys(cur, right,
3162 xfs_btree_key_addr(cur, 2, new));
3163 }
3164 xfs_btree_log_keys(cur, nbp, 1, 2);
3165
3166 /* Fill in the pointer data in the new root. */
3167 xfs_btree_copy_ptrs(cur,
3168 xfs_btree_ptr_addr(cur, 1, new), &lptr, 1);
3169 xfs_btree_copy_ptrs(cur,
3170 xfs_btree_ptr_addr(cur, 2, new), &rptr, 1);
3171 xfs_btree_log_ptrs(cur, nbp, 1, 2);
3172
3173 /* Fix up the cursor. */
3174 xfs_btree_setbuf(cur, cur->bc_nlevels, nbp);
3175 cur->bc_ptrs[cur->bc_nlevels] = nptr;
3176 cur->bc_nlevels++;
3177 *stat = 1;
3178 return 0;
3179 error0:
3180 return error;
3181 out0:
3182 *stat = 0;
3183 return 0;
3184 }
3185
3186 STATIC int
xfs_btree_make_block_unfull(struct xfs_btree_cur * cur,int level,int numrecs,int * oindex,int * index,union xfs_btree_ptr * nptr,struct xfs_btree_cur ** ncur,union xfs_btree_key * key,int * stat)3187 xfs_btree_make_block_unfull(
3188 struct xfs_btree_cur *cur, /* btree cursor */
3189 int level, /* btree level */
3190 int numrecs,/* # of recs in block */
3191 int *oindex,/* old tree index */
3192 int *index, /* new tree index */
3193 union xfs_btree_ptr *nptr, /* new btree ptr */
3194 struct xfs_btree_cur **ncur, /* new btree cursor */
3195 union xfs_btree_key *key, /* key of new block */
3196 int *stat)
3197 {
3198 int error = 0;
3199
3200 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
3201 level == cur->bc_nlevels - 1) {
3202 struct xfs_inode *ip = cur->bc_ino.ip;
3203
3204 if (numrecs < cur->bc_ops->get_dmaxrecs(cur, level)) {
3205 /* A root block that can be made bigger. */
3206 xfs_iroot_realloc(ip, 1, cur->bc_ino.whichfork);
3207 *stat = 1;
3208 } else {
3209 /* A root block that needs replacing */
3210 int logflags = 0;
3211
3212 error = xfs_btree_new_iroot(cur, &logflags, stat);
3213 if (error || *stat == 0)
3214 return error;
3215
3216 xfs_trans_log_inode(cur->bc_tp, ip, logflags);
3217 }
3218
3219 return 0;
3220 }
3221
3222 /* First, try shifting an entry to the right neighbor. */
3223 error = xfs_btree_rshift(cur, level, stat);
3224 if (error || *stat)
3225 return error;
3226
3227 /* Next, try shifting an entry to the left neighbor. */
3228 error = xfs_btree_lshift(cur, level, stat);
3229 if (error)
3230 return error;
3231
3232 if (*stat) {
3233 *oindex = *index = cur->bc_ptrs[level];
3234 return 0;
3235 }
3236
3237 /*
3238 * Next, try splitting the current block in half.
3239 *
3240 * If this works we have to re-set our variables because we
3241 * could be in a different block now.
3242 */
3243 error = xfs_btree_split(cur, level, nptr, key, ncur, stat);
3244 if (error || *stat == 0)
3245 return error;
3246
3247
3248 *index = cur->bc_ptrs[level];
3249 return 0;
3250 }
3251
3252 /*
3253 * Insert one record/level. Return information to the caller
3254 * allowing the next level up to proceed if necessary.
3255 */
3256 STATIC int
xfs_btree_insrec(struct xfs_btree_cur * cur,int level,union xfs_btree_ptr * ptrp,union xfs_btree_rec * rec,union xfs_btree_key * key,struct xfs_btree_cur ** curp,int * stat)3257 xfs_btree_insrec(
3258 struct xfs_btree_cur *cur, /* btree cursor */
3259 int level, /* level to insert record at */
3260 union xfs_btree_ptr *ptrp, /* i/o: block number inserted */
3261 union xfs_btree_rec *rec, /* record to insert */
3262 union xfs_btree_key *key, /* i/o: block key for ptrp */
3263 struct xfs_btree_cur **curp, /* output: new cursor replacing cur */
3264 int *stat) /* success/failure */
3265 {
3266 struct xfs_btree_block *block; /* btree block */
3267 struct xfs_buf *bp; /* buffer for block */
3268 union xfs_btree_ptr nptr; /* new block ptr */
3269 struct xfs_btree_cur *ncur = NULL; /* new btree cursor */
3270 union xfs_btree_key nkey; /* new block key */
3271 union xfs_btree_key *lkey;
3272 int optr; /* old key/record index */
3273 int ptr; /* key/record index */
3274 int numrecs;/* number of records */
3275 int error; /* error return value */
3276 int i;
3277 xfs_daddr_t old_bn;
3278
3279 ncur = NULL;
3280 lkey = &nkey;
3281
3282 /*
3283 * If we have an external root pointer, and we've made it to the
3284 * root level, allocate a new root block and we're done.
3285 */
3286 if (!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
3287 (level >= cur->bc_nlevels)) {
3288 error = xfs_btree_new_root(cur, stat);
3289 xfs_btree_set_ptr_null(cur, ptrp);
3290
3291 return error;
3292 }
3293
3294 /* If we're off the left edge, return failure. */
3295 ptr = cur->bc_ptrs[level];
3296 if (ptr == 0) {
3297 *stat = 0;
3298 return 0;
3299 }
3300
3301 optr = ptr;
3302
3303 XFS_BTREE_STATS_INC(cur, insrec);
3304
3305 /* Get pointers to the btree buffer and block. */
3306 block = xfs_btree_get_block(cur, level, &bp);
3307 old_bn = bp ? xfs_buf_daddr(bp) : XFS_BUF_DADDR_NULL;
3308 numrecs = xfs_btree_get_numrecs(block);
3309
3310 #ifdef DEBUG
3311 error = xfs_btree_check_block(cur, block, level, bp);
3312 if (error)
3313 goto error0;
3314
3315 /* Check that the new entry is being inserted in the right place. */
3316 if (ptr <= numrecs) {
3317 if (level == 0) {
3318 ASSERT(cur->bc_ops->recs_inorder(cur, rec,
3319 xfs_btree_rec_addr(cur, ptr, block)));
3320 } else {
3321 ASSERT(cur->bc_ops->keys_inorder(cur, key,
3322 xfs_btree_key_addr(cur, ptr, block)));
3323 }
3324 }
3325 #endif
3326
3327 /*
3328 * If the block is full, we can't insert the new entry until we
3329 * make the block un-full.
3330 */
3331 xfs_btree_set_ptr_null(cur, &nptr);
3332 if (numrecs == cur->bc_ops->get_maxrecs(cur, level)) {
3333 error = xfs_btree_make_block_unfull(cur, level, numrecs,
3334 &optr, &ptr, &nptr, &ncur, lkey, stat);
3335 if (error || *stat == 0)
3336 goto error0;
3337 }
3338
3339 /*
3340 * The current block may have changed if the block was
3341 * previously full and we have just made space in it.
3342 */
3343 block = xfs_btree_get_block(cur, level, &bp);
3344 numrecs = xfs_btree_get_numrecs(block);
3345
3346 #ifdef DEBUG
3347 error = xfs_btree_check_block(cur, block, level, bp);
3348 if (error)
3349 goto error0;
3350 #endif
3351
3352 /*
3353 * At this point we know there's room for our new entry in the block
3354 * we're pointing at.
3355 */
3356 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr + 1);
3357
3358 if (level > 0) {
3359 /* It's a nonleaf. make a hole in the keys and ptrs */
3360 union xfs_btree_key *kp;
3361 union xfs_btree_ptr *pp;
3362
3363 kp = xfs_btree_key_addr(cur, ptr, block);
3364 pp = xfs_btree_ptr_addr(cur, ptr, block);
3365
3366 for (i = numrecs - ptr; i >= 0; i--) {
3367 error = xfs_btree_debug_check_ptr(cur, pp, i, level);
3368 if (error)
3369 goto error0;
3370 }
3371
3372 xfs_btree_shift_keys(cur, kp, 1, numrecs - ptr + 1);
3373 xfs_btree_shift_ptrs(cur, pp, 1, numrecs - ptr + 1);
3374
3375 error = xfs_btree_debug_check_ptr(cur, ptrp, 0, level);
3376 if (error)
3377 goto error0;
3378
3379 /* Now put the new data in, bump numrecs and log it. */
3380 xfs_btree_copy_keys(cur, kp, key, 1);
3381 xfs_btree_copy_ptrs(cur, pp, ptrp, 1);
3382 numrecs++;
3383 xfs_btree_set_numrecs(block, numrecs);
3384 xfs_btree_log_ptrs(cur, bp, ptr, numrecs);
3385 xfs_btree_log_keys(cur, bp, ptr, numrecs);
3386 #ifdef DEBUG
3387 if (ptr < numrecs) {
3388 ASSERT(cur->bc_ops->keys_inorder(cur, kp,
3389 xfs_btree_key_addr(cur, ptr + 1, block)));
3390 }
3391 #endif
3392 } else {
3393 /* It's a leaf. make a hole in the records */
3394 union xfs_btree_rec *rp;
3395
3396 rp = xfs_btree_rec_addr(cur, ptr, block);
3397
3398 xfs_btree_shift_recs(cur, rp, 1, numrecs - ptr + 1);
3399
3400 /* Now put the new data in, bump numrecs and log it. */
3401 xfs_btree_copy_recs(cur, rp, rec, 1);
3402 xfs_btree_set_numrecs(block, ++numrecs);
3403 xfs_btree_log_recs(cur, bp, ptr, numrecs);
3404 #ifdef DEBUG
3405 if (ptr < numrecs) {
3406 ASSERT(cur->bc_ops->recs_inorder(cur, rp,
3407 xfs_btree_rec_addr(cur, ptr + 1, block)));
3408 }
3409 #endif
3410 }
3411
3412 /* Log the new number of records in the btree header. */
3413 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
3414
3415 /*
3416 * If we just inserted into a new tree block, we have to
3417 * recalculate nkey here because nkey is out of date.
3418 *
3419 * Otherwise we're just updating an existing block (having shoved
3420 * some records into the new tree block), so use the regular key
3421 * update mechanism.
3422 */
3423 if (bp && xfs_buf_daddr(bp) != old_bn) {
3424 xfs_btree_get_keys(cur, block, lkey);
3425 } else if (xfs_btree_needs_key_update(cur, optr)) {
3426 error = xfs_btree_update_keys(cur, level);
3427 if (error)
3428 goto error0;
3429 }
3430
3431 /*
3432 * If we are tracking the last record in the tree and
3433 * we are at the far right edge of the tree, update it.
3434 */
3435 if (xfs_btree_is_lastrec(cur, block, level)) {
3436 cur->bc_ops->update_lastrec(cur, block, rec,
3437 ptr, LASTREC_INSREC);
3438 }
3439
3440 /*
3441 * Return the new block number, if any.
3442 * If there is one, give back a record value and a cursor too.
3443 */
3444 *ptrp = nptr;
3445 if (!xfs_btree_ptr_is_null(cur, &nptr)) {
3446 xfs_btree_copy_keys(cur, key, lkey, 1);
3447 *curp = ncur;
3448 }
3449
3450 *stat = 1;
3451 return 0;
3452
3453 error0:
3454 if (ncur)
3455 xfs_btree_del_cursor(ncur, error);
3456 return error;
3457 }
3458
3459 /*
3460 * Insert the record at the point referenced by cur.
3461 *
3462 * A multi-level split of the tree on insert will invalidate the original
3463 * cursor. All callers of this function should assume that the cursor is
3464 * no longer valid and revalidate it.
3465 */
3466 int
xfs_btree_insert(struct xfs_btree_cur * cur,int * stat)3467 xfs_btree_insert(
3468 struct xfs_btree_cur *cur,
3469 int *stat)
3470 {
3471 int error; /* error return value */
3472 int i; /* result value, 0 for failure */
3473 int level; /* current level number in btree */
3474 union xfs_btree_ptr nptr; /* new block number (split result) */
3475 struct xfs_btree_cur *ncur; /* new cursor (split result) */
3476 struct xfs_btree_cur *pcur; /* previous level's cursor */
3477 union xfs_btree_key bkey; /* key of block to insert */
3478 union xfs_btree_key *key;
3479 union xfs_btree_rec rec; /* record to insert */
3480
3481 level = 0;
3482 ncur = NULL;
3483 pcur = cur;
3484 key = &bkey;
3485
3486 xfs_btree_set_ptr_null(cur, &nptr);
3487
3488 /* Make a key out of the record data to be inserted, and save it. */
3489 cur->bc_ops->init_rec_from_cur(cur, &rec);
3490 cur->bc_ops->init_key_from_rec(key, &rec);
3491
3492 /*
3493 * Loop going up the tree, starting at the leaf level.
3494 * Stop when we don't get a split block, that must mean that
3495 * the insert is finished with this level.
3496 */
3497 do {
3498 /*
3499 * Insert nrec/nptr into this level of the tree.
3500 * Note if we fail, nptr will be null.
3501 */
3502 error = xfs_btree_insrec(pcur, level, &nptr, &rec, key,
3503 &ncur, &i);
3504 if (error) {
3505 if (pcur != cur)
3506 xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR);
3507 goto error0;
3508 }
3509
3510 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
3511 error = -EFSCORRUPTED;
3512 goto error0;
3513 }
3514 level++;
3515
3516 /*
3517 * See if the cursor we just used is trash.
3518 * Can't trash the caller's cursor, but otherwise we should
3519 * if ncur is a new cursor or we're about to be done.
3520 */
3521 if (pcur != cur &&
3522 (ncur || xfs_btree_ptr_is_null(cur, &nptr))) {
3523 /* Save the state from the cursor before we trash it */
3524 if (cur->bc_ops->update_cursor)
3525 cur->bc_ops->update_cursor(pcur, cur);
3526 cur->bc_nlevels = pcur->bc_nlevels;
3527 xfs_btree_del_cursor(pcur, XFS_BTREE_NOERROR);
3528 }
3529 /* If we got a new cursor, switch to it. */
3530 if (ncur) {
3531 pcur = ncur;
3532 ncur = NULL;
3533 }
3534 } while (!xfs_btree_ptr_is_null(cur, &nptr));
3535
3536 *stat = i;
3537 return 0;
3538 error0:
3539 return error;
3540 }
3541
3542 /*
3543 * Try to merge a non-leaf block back into the inode root.
3544 *
3545 * Note: the killroot names comes from the fact that we're effectively
3546 * killing the old root block. But because we can't just delete the
3547 * inode we have to copy the single block it was pointing to into the
3548 * inode.
3549 */
3550 STATIC int
xfs_btree_kill_iroot(struct xfs_btree_cur * cur)3551 xfs_btree_kill_iroot(
3552 struct xfs_btree_cur *cur)
3553 {
3554 int whichfork = cur->bc_ino.whichfork;
3555 struct xfs_inode *ip = cur->bc_ino.ip;
3556 struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork);
3557 struct xfs_btree_block *block;
3558 struct xfs_btree_block *cblock;
3559 union xfs_btree_key *kp;
3560 union xfs_btree_key *ckp;
3561 union xfs_btree_ptr *pp;
3562 union xfs_btree_ptr *cpp;
3563 struct xfs_buf *cbp;
3564 int level;
3565 int index;
3566 int numrecs;
3567 int error;
3568 #ifdef DEBUG
3569 union xfs_btree_ptr ptr;
3570 #endif
3571 int i;
3572
3573 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
3574 ASSERT(cur->bc_nlevels > 1);
3575
3576 /*
3577 * Don't deal with the root block needs to be a leaf case.
3578 * We're just going to turn the thing back into extents anyway.
3579 */
3580 level = cur->bc_nlevels - 1;
3581 if (level == 1)
3582 goto out0;
3583
3584 /*
3585 * Give up if the root has multiple children.
3586 */
3587 block = xfs_btree_get_iroot(cur);
3588 if (xfs_btree_get_numrecs(block) != 1)
3589 goto out0;
3590
3591 cblock = xfs_btree_get_block(cur, level - 1, &cbp);
3592 numrecs = xfs_btree_get_numrecs(cblock);
3593
3594 /*
3595 * Only do this if the next level will fit.
3596 * Then the data must be copied up to the inode,
3597 * instead of freeing the root you free the next level.
3598 */
3599 if (numrecs > cur->bc_ops->get_dmaxrecs(cur, level))
3600 goto out0;
3601
3602 XFS_BTREE_STATS_INC(cur, killroot);
3603
3604 #ifdef DEBUG
3605 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
3606 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
3607 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
3608 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
3609 #endif
3610
3611 index = numrecs - cur->bc_ops->get_maxrecs(cur, level);
3612 if (index) {
3613 xfs_iroot_realloc(cur->bc_ino.ip, index,
3614 cur->bc_ino.whichfork);
3615 block = ifp->if_broot;
3616 }
3617
3618 be16_add_cpu(&block->bb_numrecs, index);
3619 ASSERT(block->bb_numrecs == cblock->bb_numrecs);
3620
3621 kp = xfs_btree_key_addr(cur, 1, block);
3622 ckp = xfs_btree_key_addr(cur, 1, cblock);
3623 xfs_btree_copy_keys(cur, kp, ckp, numrecs);
3624
3625 pp = xfs_btree_ptr_addr(cur, 1, block);
3626 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
3627
3628 for (i = 0; i < numrecs; i++) {
3629 error = xfs_btree_debug_check_ptr(cur, cpp, i, level - 1);
3630 if (error)
3631 return error;
3632 }
3633
3634 xfs_btree_copy_ptrs(cur, pp, cpp, numrecs);
3635
3636 error = xfs_btree_free_block(cur, cbp);
3637 if (error)
3638 return error;
3639
3640 cur->bc_bufs[level - 1] = NULL;
3641 be16_add_cpu(&block->bb_level, -1);
3642 xfs_trans_log_inode(cur->bc_tp, ip,
3643 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_ino.whichfork));
3644 cur->bc_nlevels--;
3645 out0:
3646 return 0;
3647 }
3648
3649 /*
3650 * Kill the current root node, and replace it with it's only child node.
3651 */
3652 STATIC int
xfs_btree_kill_root(struct xfs_btree_cur * cur,struct xfs_buf * bp,int level,union xfs_btree_ptr * newroot)3653 xfs_btree_kill_root(
3654 struct xfs_btree_cur *cur,
3655 struct xfs_buf *bp,
3656 int level,
3657 union xfs_btree_ptr *newroot)
3658 {
3659 int error;
3660
3661 XFS_BTREE_STATS_INC(cur, killroot);
3662
3663 /*
3664 * Update the root pointer, decreasing the level by 1 and then
3665 * free the old root.
3666 */
3667 cur->bc_ops->set_root(cur, newroot, -1);
3668
3669 error = xfs_btree_free_block(cur, bp);
3670 if (error)
3671 return error;
3672
3673 cur->bc_bufs[level] = NULL;
3674 cur->bc_ra[level] = 0;
3675 cur->bc_nlevels--;
3676
3677 return 0;
3678 }
3679
3680 STATIC int
xfs_btree_dec_cursor(struct xfs_btree_cur * cur,int level,int * stat)3681 xfs_btree_dec_cursor(
3682 struct xfs_btree_cur *cur,
3683 int level,
3684 int *stat)
3685 {
3686 int error;
3687 int i;
3688
3689 if (level > 0) {
3690 error = xfs_btree_decrement(cur, level, &i);
3691 if (error)
3692 return error;
3693 }
3694
3695 *stat = 1;
3696 return 0;
3697 }
3698
3699 /*
3700 * Single level of the btree record deletion routine.
3701 * Delete record pointed to by cur/level.
3702 * Remove the record from its block then rebalance the tree.
3703 * Return 0 for error, 1 for done, 2 to go on to the next level.
3704 */
3705 STATIC int /* error */
xfs_btree_delrec(struct xfs_btree_cur * cur,int level,int * stat)3706 xfs_btree_delrec(
3707 struct xfs_btree_cur *cur, /* btree cursor */
3708 int level, /* level removing record from */
3709 int *stat) /* fail/done/go-on */
3710 {
3711 struct xfs_btree_block *block; /* btree block */
3712 union xfs_btree_ptr cptr; /* current block ptr */
3713 struct xfs_buf *bp; /* buffer for block */
3714 int error; /* error return value */
3715 int i; /* loop counter */
3716 union xfs_btree_ptr lptr; /* left sibling block ptr */
3717 struct xfs_buf *lbp; /* left buffer pointer */
3718 struct xfs_btree_block *left; /* left btree block */
3719 int lrecs = 0; /* left record count */
3720 int ptr; /* key/record index */
3721 union xfs_btree_ptr rptr; /* right sibling block ptr */
3722 struct xfs_buf *rbp; /* right buffer pointer */
3723 struct xfs_btree_block *right; /* right btree block */
3724 struct xfs_btree_block *rrblock; /* right-right btree block */
3725 struct xfs_buf *rrbp; /* right-right buffer pointer */
3726 int rrecs = 0; /* right record count */
3727 struct xfs_btree_cur *tcur; /* temporary btree cursor */
3728 int numrecs; /* temporary numrec count */
3729
3730 tcur = NULL;
3731
3732 /* Get the index of the entry being deleted, check for nothing there. */
3733 ptr = cur->bc_ptrs[level];
3734 if (ptr == 0) {
3735 *stat = 0;
3736 return 0;
3737 }
3738
3739 /* Get the buffer & block containing the record or key/ptr. */
3740 block = xfs_btree_get_block(cur, level, &bp);
3741 numrecs = xfs_btree_get_numrecs(block);
3742
3743 #ifdef DEBUG
3744 error = xfs_btree_check_block(cur, block, level, bp);
3745 if (error)
3746 goto error0;
3747 #endif
3748
3749 /* Fail if we're off the end of the block. */
3750 if (ptr > numrecs) {
3751 *stat = 0;
3752 return 0;
3753 }
3754
3755 XFS_BTREE_STATS_INC(cur, delrec);
3756 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr);
3757
3758 /* Excise the entries being deleted. */
3759 if (level > 0) {
3760 /* It's a nonleaf. operate on keys and ptrs */
3761 union xfs_btree_key *lkp;
3762 union xfs_btree_ptr *lpp;
3763
3764 lkp = xfs_btree_key_addr(cur, ptr + 1, block);
3765 lpp = xfs_btree_ptr_addr(cur, ptr + 1, block);
3766
3767 for (i = 0; i < numrecs - ptr; i++) {
3768 error = xfs_btree_debug_check_ptr(cur, lpp, i, level);
3769 if (error)
3770 goto error0;
3771 }
3772
3773 if (ptr < numrecs) {
3774 xfs_btree_shift_keys(cur, lkp, -1, numrecs - ptr);
3775 xfs_btree_shift_ptrs(cur, lpp, -1, numrecs - ptr);
3776 xfs_btree_log_keys(cur, bp, ptr, numrecs - 1);
3777 xfs_btree_log_ptrs(cur, bp, ptr, numrecs - 1);
3778 }
3779 } else {
3780 /* It's a leaf. operate on records */
3781 if (ptr < numrecs) {
3782 xfs_btree_shift_recs(cur,
3783 xfs_btree_rec_addr(cur, ptr + 1, block),
3784 -1, numrecs - ptr);
3785 xfs_btree_log_recs(cur, bp, ptr, numrecs - 1);
3786 }
3787 }
3788
3789 /*
3790 * Decrement and log the number of entries in the block.
3791 */
3792 xfs_btree_set_numrecs(block, --numrecs);
3793 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
3794
3795 /*
3796 * If we are tracking the last record in the tree and
3797 * we are at the far right edge of the tree, update it.
3798 */
3799 if (xfs_btree_is_lastrec(cur, block, level)) {
3800 cur->bc_ops->update_lastrec(cur, block, NULL,
3801 ptr, LASTREC_DELREC);
3802 }
3803
3804 /*
3805 * We're at the root level. First, shrink the root block in-memory.
3806 * Try to get rid of the next level down. If we can't then there's
3807 * nothing left to do.
3808 */
3809 if (level == cur->bc_nlevels - 1) {
3810 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3811 xfs_iroot_realloc(cur->bc_ino.ip, -1,
3812 cur->bc_ino.whichfork);
3813
3814 error = xfs_btree_kill_iroot(cur);
3815 if (error)
3816 goto error0;
3817
3818 error = xfs_btree_dec_cursor(cur, level, stat);
3819 if (error)
3820 goto error0;
3821 *stat = 1;
3822 return 0;
3823 }
3824
3825 /*
3826 * If this is the root level, and there's only one entry left,
3827 * and it's NOT the leaf level, then we can get rid of this
3828 * level.
3829 */
3830 if (numrecs == 1 && level > 0) {
3831 union xfs_btree_ptr *pp;
3832 /*
3833 * pp is still set to the first pointer in the block.
3834 * Make it the new root of the btree.
3835 */
3836 pp = xfs_btree_ptr_addr(cur, 1, block);
3837 error = xfs_btree_kill_root(cur, bp, level, pp);
3838 if (error)
3839 goto error0;
3840 } else if (level > 0) {
3841 error = xfs_btree_dec_cursor(cur, level, stat);
3842 if (error)
3843 goto error0;
3844 }
3845 *stat = 1;
3846 return 0;
3847 }
3848
3849 /*
3850 * If we deleted the leftmost entry in the block, update the
3851 * key values above us in the tree.
3852 */
3853 if (xfs_btree_needs_key_update(cur, ptr)) {
3854 error = xfs_btree_update_keys(cur, level);
3855 if (error)
3856 goto error0;
3857 }
3858
3859 /*
3860 * If the number of records remaining in the block is at least
3861 * the minimum, we're done.
3862 */
3863 if (numrecs >= cur->bc_ops->get_minrecs(cur, level)) {
3864 error = xfs_btree_dec_cursor(cur, level, stat);
3865 if (error)
3866 goto error0;
3867 return 0;
3868 }
3869
3870 /*
3871 * Otherwise, we have to move some records around to keep the
3872 * tree balanced. Look at the left and right sibling blocks to
3873 * see if we can re-balance by moving only one record.
3874 */
3875 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
3876 xfs_btree_get_sibling(cur, block, &lptr, XFS_BB_LEFTSIB);
3877
3878 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3879 /*
3880 * One child of root, need to get a chance to copy its contents
3881 * into the root and delete it. Can't go up to next level,
3882 * there's nothing to delete there.
3883 */
3884 if (xfs_btree_ptr_is_null(cur, &rptr) &&
3885 xfs_btree_ptr_is_null(cur, &lptr) &&
3886 level == cur->bc_nlevels - 2) {
3887 error = xfs_btree_kill_iroot(cur);
3888 if (!error)
3889 error = xfs_btree_dec_cursor(cur, level, stat);
3890 if (error)
3891 goto error0;
3892 return 0;
3893 }
3894 }
3895
3896 ASSERT(!xfs_btree_ptr_is_null(cur, &rptr) ||
3897 !xfs_btree_ptr_is_null(cur, &lptr));
3898
3899 /*
3900 * Duplicate the cursor so our btree manipulations here won't
3901 * disrupt the next level up.
3902 */
3903 error = xfs_btree_dup_cursor(cur, &tcur);
3904 if (error)
3905 goto error0;
3906
3907 /*
3908 * If there's a right sibling, see if it's ok to shift an entry
3909 * out of it.
3910 */
3911 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
3912 /*
3913 * Move the temp cursor to the last entry in the next block.
3914 * Actually any entry but the first would suffice.
3915 */
3916 i = xfs_btree_lastrec(tcur, level);
3917 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
3918 error = -EFSCORRUPTED;
3919 goto error0;
3920 }
3921
3922 error = xfs_btree_increment(tcur, level, &i);
3923 if (error)
3924 goto error0;
3925 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
3926 error = -EFSCORRUPTED;
3927 goto error0;
3928 }
3929
3930 i = xfs_btree_lastrec(tcur, level);
3931 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
3932 error = -EFSCORRUPTED;
3933 goto error0;
3934 }
3935
3936 /* Grab a pointer to the block. */
3937 right = xfs_btree_get_block(tcur, level, &rbp);
3938 #ifdef DEBUG
3939 error = xfs_btree_check_block(tcur, right, level, rbp);
3940 if (error)
3941 goto error0;
3942 #endif
3943 /* Grab the current block number, for future use. */
3944 xfs_btree_get_sibling(tcur, right, &cptr, XFS_BB_LEFTSIB);
3945
3946 /*
3947 * If right block is full enough so that removing one entry
3948 * won't make it too empty, and left-shifting an entry out
3949 * of right to us works, we're done.
3950 */
3951 if (xfs_btree_get_numrecs(right) - 1 >=
3952 cur->bc_ops->get_minrecs(tcur, level)) {
3953 error = xfs_btree_lshift(tcur, level, &i);
3954 if (error)
3955 goto error0;
3956 if (i) {
3957 ASSERT(xfs_btree_get_numrecs(block) >=
3958 cur->bc_ops->get_minrecs(tcur, level));
3959
3960 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3961 tcur = NULL;
3962
3963 error = xfs_btree_dec_cursor(cur, level, stat);
3964 if (error)
3965 goto error0;
3966 return 0;
3967 }
3968 }
3969
3970 /*
3971 * Otherwise, grab the number of records in right for
3972 * future reference, and fix up the temp cursor to point
3973 * to our block again (last record).
3974 */
3975 rrecs = xfs_btree_get_numrecs(right);
3976 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3977 i = xfs_btree_firstrec(tcur, level);
3978 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
3979 error = -EFSCORRUPTED;
3980 goto error0;
3981 }
3982
3983 error = xfs_btree_decrement(tcur, level, &i);
3984 if (error)
3985 goto error0;
3986 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
3987 error = -EFSCORRUPTED;
3988 goto error0;
3989 }
3990 }
3991 }
3992
3993 /*
3994 * If there's a left sibling, see if it's ok to shift an entry
3995 * out of it.
3996 */
3997 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3998 /*
3999 * Move the temp cursor to the first entry in the
4000 * previous block.
4001 */
4002 i = xfs_btree_firstrec(tcur, level);
4003 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
4004 error = -EFSCORRUPTED;
4005 goto error0;
4006 }
4007
4008 error = xfs_btree_decrement(tcur, level, &i);
4009 if (error)
4010 goto error0;
4011 i = xfs_btree_firstrec(tcur, level);
4012 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
4013 error = -EFSCORRUPTED;
4014 goto error0;
4015 }
4016
4017 /* Grab a pointer to the block. */
4018 left = xfs_btree_get_block(tcur, level, &lbp);
4019 #ifdef DEBUG
4020 error = xfs_btree_check_block(cur, left, level, lbp);
4021 if (error)
4022 goto error0;
4023 #endif
4024 /* Grab the current block number, for future use. */
4025 xfs_btree_get_sibling(tcur, left, &cptr, XFS_BB_RIGHTSIB);
4026
4027 /*
4028 * If left block is full enough so that removing one entry
4029 * won't make it too empty, and right-shifting an entry out
4030 * of left to us works, we're done.
4031 */
4032 if (xfs_btree_get_numrecs(left) - 1 >=
4033 cur->bc_ops->get_minrecs(tcur, level)) {
4034 error = xfs_btree_rshift(tcur, level, &i);
4035 if (error)
4036 goto error0;
4037 if (i) {
4038 ASSERT(xfs_btree_get_numrecs(block) >=
4039 cur->bc_ops->get_minrecs(tcur, level));
4040 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
4041 tcur = NULL;
4042 if (level == 0)
4043 cur->bc_ptrs[0]++;
4044
4045 *stat = 1;
4046 return 0;
4047 }
4048 }
4049
4050 /*
4051 * Otherwise, grab the number of records in right for
4052 * future reference.
4053 */
4054 lrecs = xfs_btree_get_numrecs(left);
4055 }
4056
4057 /* Delete the temp cursor, we're done with it. */
4058 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
4059 tcur = NULL;
4060
4061 /* If here, we need to do a join to keep the tree balanced. */
4062 ASSERT(!xfs_btree_ptr_is_null(cur, &cptr));
4063
4064 if (!xfs_btree_ptr_is_null(cur, &lptr) &&
4065 lrecs + xfs_btree_get_numrecs(block) <=
4066 cur->bc_ops->get_maxrecs(cur, level)) {
4067 /*
4068 * Set "right" to be the starting block,
4069 * "left" to be the left neighbor.
4070 */
4071 rptr = cptr;
4072 right = block;
4073 rbp = bp;
4074 error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
4075 if (error)
4076 goto error0;
4077
4078 /*
4079 * If that won't work, see if we can join with the right neighbor block.
4080 */
4081 } else if (!xfs_btree_ptr_is_null(cur, &rptr) &&
4082 rrecs + xfs_btree_get_numrecs(block) <=
4083 cur->bc_ops->get_maxrecs(cur, level)) {
4084 /*
4085 * Set "left" to be the starting block,
4086 * "right" to be the right neighbor.
4087 */
4088 lptr = cptr;
4089 left = block;
4090 lbp = bp;
4091 error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
4092 if (error)
4093 goto error0;
4094
4095 /*
4096 * Otherwise, we can't fix the imbalance.
4097 * Just return. This is probably a logic error, but it's not fatal.
4098 */
4099 } else {
4100 error = xfs_btree_dec_cursor(cur, level, stat);
4101 if (error)
4102 goto error0;
4103 return 0;
4104 }
4105
4106 rrecs = xfs_btree_get_numrecs(right);
4107 lrecs = xfs_btree_get_numrecs(left);
4108
4109 /*
4110 * We're now going to join "left" and "right" by moving all the stuff
4111 * in "right" to "left" and deleting "right".
4112 */
4113 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
4114 if (level > 0) {
4115 /* It's a non-leaf. Move keys and pointers. */
4116 union xfs_btree_key *lkp; /* left btree key */
4117 union xfs_btree_ptr *lpp; /* left address pointer */
4118 union xfs_btree_key *rkp; /* right btree key */
4119 union xfs_btree_ptr *rpp; /* right address pointer */
4120
4121 lkp = xfs_btree_key_addr(cur, lrecs + 1, left);
4122 lpp = xfs_btree_ptr_addr(cur, lrecs + 1, left);
4123 rkp = xfs_btree_key_addr(cur, 1, right);
4124 rpp = xfs_btree_ptr_addr(cur, 1, right);
4125
4126 for (i = 1; i < rrecs; i++) {
4127 error = xfs_btree_debug_check_ptr(cur, rpp, i, level);
4128 if (error)
4129 goto error0;
4130 }
4131
4132 xfs_btree_copy_keys(cur, lkp, rkp, rrecs);
4133 xfs_btree_copy_ptrs(cur, lpp, rpp, rrecs);
4134
4135 xfs_btree_log_keys(cur, lbp, lrecs + 1, lrecs + rrecs);
4136 xfs_btree_log_ptrs(cur, lbp, lrecs + 1, lrecs + rrecs);
4137 } else {
4138 /* It's a leaf. Move records. */
4139 union xfs_btree_rec *lrp; /* left record pointer */
4140 union xfs_btree_rec *rrp; /* right record pointer */
4141
4142 lrp = xfs_btree_rec_addr(cur, lrecs + 1, left);
4143 rrp = xfs_btree_rec_addr(cur, 1, right);
4144
4145 xfs_btree_copy_recs(cur, lrp, rrp, rrecs);
4146 xfs_btree_log_recs(cur, lbp, lrecs + 1, lrecs + rrecs);
4147 }
4148
4149 XFS_BTREE_STATS_INC(cur, join);
4150
4151 /*
4152 * Fix up the number of records and right block pointer in the
4153 * surviving block, and log it.
4154 */
4155 xfs_btree_set_numrecs(left, lrecs + rrecs);
4156 xfs_btree_get_sibling(cur, right, &cptr, XFS_BB_RIGHTSIB);
4157 xfs_btree_set_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
4158 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
4159
4160 /* If there is a right sibling, point it to the remaining block. */
4161 xfs_btree_get_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
4162 if (!xfs_btree_ptr_is_null(cur, &cptr)) {
4163 error = xfs_btree_read_buf_block(cur, &cptr, 0, &rrblock, &rrbp);
4164 if (error)
4165 goto error0;
4166 xfs_btree_set_sibling(cur, rrblock, &lptr, XFS_BB_LEFTSIB);
4167 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
4168 }
4169
4170 /* Free the deleted block. */
4171 error = xfs_btree_free_block(cur, rbp);
4172 if (error)
4173 goto error0;
4174
4175 /*
4176 * If we joined with the left neighbor, set the buffer in the
4177 * cursor to the left block, and fix up the index.
4178 */
4179 if (bp != lbp) {
4180 cur->bc_bufs[level] = lbp;
4181 cur->bc_ptrs[level] += lrecs;
4182 cur->bc_ra[level] = 0;
4183 }
4184 /*
4185 * If we joined with the right neighbor and there's a level above
4186 * us, increment the cursor at that level.
4187 */
4188 else if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) ||
4189 (level + 1 < cur->bc_nlevels)) {
4190 error = xfs_btree_increment(cur, level + 1, &i);
4191 if (error)
4192 goto error0;
4193 }
4194
4195 /*
4196 * Readjust the ptr at this level if it's not a leaf, since it's
4197 * still pointing at the deletion point, which makes the cursor
4198 * inconsistent. If this makes the ptr 0, the caller fixes it up.
4199 * We can't use decrement because it would change the next level up.
4200 */
4201 if (level > 0)
4202 cur->bc_ptrs[level]--;
4203
4204 /*
4205 * We combined blocks, so we have to update the parent keys if the
4206 * btree supports overlapped intervals. However, bc_ptrs[level + 1]
4207 * points to the old block so that the caller knows which record to
4208 * delete. Therefore, the caller must be savvy enough to call updkeys
4209 * for us if we return stat == 2. The other exit points from this
4210 * function don't require deletions further up the tree, so they can
4211 * call updkeys directly.
4212 */
4213
4214 /* Return value means the next level up has something to do. */
4215 *stat = 2;
4216 return 0;
4217
4218 error0:
4219 if (tcur)
4220 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
4221 return error;
4222 }
4223
4224 /*
4225 * Delete the record pointed to by cur.
4226 * The cursor refers to the place where the record was (could be inserted)
4227 * when the operation returns.
4228 */
4229 int /* error */
xfs_btree_delete(struct xfs_btree_cur * cur,int * stat)4230 xfs_btree_delete(
4231 struct xfs_btree_cur *cur,
4232 int *stat) /* success/failure */
4233 {
4234 int error; /* error return value */
4235 int level;
4236 int i;
4237 bool joined = false;
4238
4239 /*
4240 * Go up the tree, starting at leaf level.
4241 *
4242 * If 2 is returned then a join was done; go to the next level.
4243 * Otherwise we are done.
4244 */
4245 for (level = 0, i = 2; i == 2; level++) {
4246 error = xfs_btree_delrec(cur, level, &i);
4247 if (error)
4248 goto error0;
4249 if (i == 2)
4250 joined = true;
4251 }
4252
4253 /*
4254 * If we combined blocks as part of deleting the record, delrec won't
4255 * have updated the parent high keys so we have to do that here.
4256 */
4257 if (joined && (cur->bc_flags & XFS_BTREE_OVERLAPPING)) {
4258 error = xfs_btree_updkeys_force(cur, 0);
4259 if (error)
4260 goto error0;
4261 }
4262
4263 if (i == 0) {
4264 for (level = 1; level < cur->bc_nlevels; level++) {
4265 if (cur->bc_ptrs[level] == 0) {
4266 error = xfs_btree_decrement(cur, level, &i);
4267 if (error)
4268 goto error0;
4269 break;
4270 }
4271 }
4272 }
4273
4274 *stat = i;
4275 return 0;
4276 error0:
4277 return error;
4278 }
4279
4280 /*
4281 * Get the data from the pointed-to record.
4282 */
4283 int /* error */
xfs_btree_get_rec(struct xfs_btree_cur * cur,union xfs_btree_rec ** recp,int * stat)4284 xfs_btree_get_rec(
4285 struct xfs_btree_cur *cur, /* btree cursor */
4286 union xfs_btree_rec **recp, /* output: btree record */
4287 int *stat) /* output: success/failure */
4288 {
4289 struct xfs_btree_block *block; /* btree block */
4290 struct xfs_buf *bp; /* buffer pointer */
4291 int ptr; /* record number */
4292 #ifdef DEBUG
4293 int error; /* error return value */
4294 #endif
4295
4296 ptr = cur->bc_ptrs[0];
4297 block = xfs_btree_get_block(cur, 0, &bp);
4298
4299 #ifdef DEBUG
4300 error = xfs_btree_check_block(cur, block, 0, bp);
4301 if (error)
4302 return error;
4303 #endif
4304
4305 /*
4306 * Off the right end or left end, return failure.
4307 */
4308 if (ptr > xfs_btree_get_numrecs(block) || ptr <= 0) {
4309 *stat = 0;
4310 return 0;
4311 }
4312
4313 /*
4314 * Point to the record and extract its data.
4315 */
4316 *recp = xfs_btree_rec_addr(cur, ptr, block);
4317 *stat = 1;
4318 return 0;
4319 }
4320
4321 /* Visit a block in a btree. */
4322 STATIC int
xfs_btree_visit_block(struct xfs_btree_cur * cur,int level,xfs_btree_visit_blocks_fn fn,void * data)4323 xfs_btree_visit_block(
4324 struct xfs_btree_cur *cur,
4325 int level,
4326 xfs_btree_visit_blocks_fn fn,
4327 void *data)
4328 {
4329 struct xfs_btree_block *block;
4330 struct xfs_buf *bp;
4331 union xfs_btree_ptr rptr;
4332 int error;
4333
4334 /* do right sibling readahead */
4335 xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
4336 block = xfs_btree_get_block(cur, level, &bp);
4337
4338 /* process the block */
4339 error = fn(cur, level, data);
4340 if (error)
4341 return error;
4342
4343 /* now read rh sibling block for next iteration */
4344 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
4345 if (xfs_btree_ptr_is_null(cur, &rptr))
4346 return -ENOENT;
4347
4348 /*
4349 * We only visit blocks once in this walk, so we have to avoid the
4350 * internal xfs_btree_lookup_get_block() optimisation where it will
4351 * return the same block without checking if the right sibling points
4352 * back to us and creates a cyclic reference in the btree.
4353 */
4354 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
4355 if (be64_to_cpu(rptr.l) == XFS_DADDR_TO_FSB(cur->bc_mp,
4356 xfs_buf_daddr(bp)))
4357 return -EFSCORRUPTED;
4358 } else {
4359 if (be32_to_cpu(rptr.s) == xfs_daddr_to_agbno(cur->bc_mp,
4360 xfs_buf_daddr(bp)))
4361 return -EFSCORRUPTED;
4362 }
4363 return xfs_btree_lookup_get_block(cur, level, &rptr, &block);
4364 }
4365
4366
4367 /* Visit every block in a btree. */
4368 int
xfs_btree_visit_blocks(struct xfs_btree_cur * cur,xfs_btree_visit_blocks_fn fn,unsigned int flags,void * data)4369 xfs_btree_visit_blocks(
4370 struct xfs_btree_cur *cur,
4371 xfs_btree_visit_blocks_fn fn,
4372 unsigned int flags,
4373 void *data)
4374 {
4375 union xfs_btree_ptr lptr;
4376 int level;
4377 struct xfs_btree_block *block = NULL;
4378 int error = 0;
4379
4380 cur->bc_ops->init_ptr_from_cur(cur, &lptr);
4381
4382 /* for each level */
4383 for (level = cur->bc_nlevels - 1; level >= 0; level--) {
4384 /* grab the left hand block */
4385 error = xfs_btree_lookup_get_block(cur, level, &lptr, &block);
4386 if (error)
4387 return error;
4388
4389 /* readahead the left most block for the next level down */
4390 if (level > 0) {
4391 union xfs_btree_ptr *ptr;
4392
4393 ptr = xfs_btree_ptr_addr(cur, 1, block);
4394 xfs_btree_readahead_ptr(cur, ptr, 1);
4395
4396 /* save for the next iteration of the loop */
4397 xfs_btree_copy_ptrs(cur, &lptr, ptr, 1);
4398
4399 if (!(flags & XFS_BTREE_VISIT_LEAVES))
4400 continue;
4401 } else if (!(flags & XFS_BTREE_VISIT_RECORDS)) {
4402 continue;
4403 }
4404
4405 /* for each buffer in the level */
4406 do {
4407 error = xfs_btree_visit_block(cur, level, fn, data);
4408 } while (!error);
4409
4410 if (error != -ENOENT)
4411 return error;
4412 }
4413
4414 return 0;
4415 }
4416
4417 /*
4418 * Change the owner of a btree.
4419 *
4420 * The mechanism we use here is ordered buffer logging. Because we don't know
4421 * how many buffers were are going to need to modify, we don't really want to
4422 * have to make transaction reservations for the worst case of every buffer in a
4423 * full size btree as that may be more space that we can fit in the log....
4424 *
4425 * We do the btree walk in the most optimal manner possible - we have sibling
4426 * pointers so we can just walk all the blocks on each level from left to right
4427 * in a single pass, and then move to the next level and do the same. We can
4428 * also do readahead on the sibling pointers to get IO moving more quickly,
4429 * though for slow disks this is unlikely to make much difference to performance
4430 * as the amount of CPU work we have to do before moving to the next block is
4431 * relatively small.
4432 *
4433 * For each btree block that we load, modify the owner appropriately, set the
4434 * buffer as an ordered buffer and log it appropriately. We need to ensure that
4435 * we mark the region we change dirty so that if the buffer is relogged in
4436 * a subsequent transaction the changes we make here as an ordered buffer are
4437 * correctly relogged in that transaction. If we are in recovery context, then
4438 * just queue the modified buffer as delayed write buffer so the transaction
4439 * recovery completion writes the changes to disk.
4440 */
4441 struct xfs_btree_block_change_owner_info {
4442 uint64_t new_owner;
4443 struct list_head *buffer_list;
4444 };
4445
4446 static int
xfs_btree_block_change_owner(struct xfs_btree_cur * cur,int level,void * data)4447 xfs_btree_block_change_owner(
4448 struct xfs_btree_cur *cur,
4449 int level,
4450 void *data)
4451 {
4452 struct xfs_btree_block_change_owner_info *bbcoi = data;
4453 struct xfs_btree_block *block;
4454 struct xfs_buf *bp;
4455
4456 /* modify the owner */
4457 block = xfs_btree_get_block(cur, level, &bp);
4458 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
4459 if (block->bb_u.l.bb_owner == cpu_to_be64(bbcoi->new_owner))
4460 return 0;
4461 block->bb_u.l.bb_owner = cpu_to_be64(bbcoi->new_owner);
4462 } else {
4463 if (block->bb_u.s.bb_owner == cpu_to_be32(bbcoi->new_owner))
4464 return 0;
4465 block->bb_u.s.bb_owner = cpu_to_be32(bbcoi->new_owner);
4466 }
4467
4468 /*
4469 * If the block is a root block hosted in an inode, we might not have a
4470 * buffer pointer here and we shouldn't attempt to log the change as the
4471 * information is already held in the inode and discarded when the root
4472 * block is formatted into the on-disk inode fork. We still change it,
4473 * though, so everything is consistent in memory.
4474 */
4475 if (!bp) {
4476 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
4477 ASSERT(level == cur->bc_nlevels - 1);
4478 return 0;
4479 }
4480
4481 if (cur->bc_tp) {
4482 if (!xfs_trans_ordered_buf(cur->bc_tp, bp)) {
4483 xfs_btree_log_block(cur, bp, XFS_BB_OWNER);
4484 return -EAGAIN;
4485 }
4486 } else {
4487 xfs_buf_delwri_queue(bp, bbcoi->buffer_list);
4488 }
4489
4490 return 0;
4491 }
4492
4493 int
xfs_btree_change_owner(struct xfs_btree_cur * cur,uint64_t new_owner,struct list_head * buffer_list)4494 xfs_btree_change_owner(
4495 struct xfs_btree_cur *cur,
4496 uint64_t new_owner,
4497 struct list_head *buffer_list)
4498 {
4499 struct xfs_btree_block_change_owner_info bbcoi;
4500
4501 bbcoi.new_owner = new_owner;
4502 bbcoi.buffer_list = buffer_list;
4503
4504 return xfs_btree_visit_blocks(cur, xfs_btree_block_change_owner,
4505 XFS_BTREE_VISIT_ALL, &bbcoi);
4506 }
4507
4508 /* Verify the v5 fields of a long-format btree block. */
4509 xfs_failaddr_t
xfs_btree_lblock_v5hdr_verify(struct xfs_buf * bp,uint64_t owner)4510 xfs_btree_lblock_v5hdr_verify(
4511 struct xfs_buf *bp,
4512 uint64_t owner)
4513 {
4514 struct xfs_mount *mp = bp->b_mount;
4515 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
4516
4517 if (!xfs_has_crc(mp))
4518 return __this_address;
4519 if (!uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid))
4520 return __this_address;
4521 if (block->bb_u.l.bb_blkno != cpu_to_be64(xfs_buf_daddr(bp)))
4522 return __this_address;
4523 if (owner != XFS_RMAP_OWN_UNKNOWN &&
4524 be64_to_cpu(block->bb_u.l.bb_owner) != owner)
4525 return __this_address;
4526 return NULL;
4527 }
4528
4529 /* Verify a long-format btree block. */
4530 xfs_failaddr_t
xfs_btree_lblock_verify(struct xfs_buf * bp,unsigned int max_recs)4531 xfs_btree_lblock_verify(
4532 struct xfs_buf *bp,
4533 unsigned int max_recs)
4534 {
4535 struct xfs_mount *mp = bp->b_mount;
4536 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
4537 xfs_fsblock_t fsb;
4538 xfs_failaddr_t fa;
4539
4540 /* numrecs verification */
4541 if (be16_to_cpu(block->bb_numrecs) > max_recs)
4542 return __this_address;
4543
4544 /* sibling pointer verification */
4545 fsb = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp));
4546 fa = xfs_btree_check_lblock_siblings(mp, NULL, -1, fsb,
4547 block->bb_u.l.bb_leftsib);
4548 if (!fa)
4549 fa = xfs_btree_check_lblock_siblings(mp, NULL, -1, fsb,
4550 block->bb_u.l.bb_rightsib);
4551 return fa;
4552 }
4553
4554 /**
4555 * xfs_btree_sblock_v5hdr_verify() -- verify the v5 fields of a short-format
4556 * btree block
4557 *
4558 * @bp: buffer containing the btree block
4559 */
4560 xfs_failaddr_t
xfs_btree_sblock_v5hdr_verify(struct xfs_buf * bp)4561 xfs_btree_sblock_v5hdr_verify(
4562 struct xfs_buf *bp)
4563 {
4564 struct xfs_mount *mp = bp->b_mount;
4565 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
4566 struct xfs_perag *pag = bp->b_pag;
4567
4568 if (!xfs_has_crc(mp))
4569 return __this_address;
4570 if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid))
4571 return __this_address;
4572 if (block->bb_u.s.bb_blkno != cpu_to_be64(xfs_buf_daddr(bp)))
4573 return __this_address;
4574 if (pag && be32_to_cpu(block->bb_u.s.bb_owner) != pag->pag_agno)
4575 return __this_address;
4576 return NULL;
4577 }
4578
4579 /**
4580 * xfs_btree_sblock_verify() -- verify a short-format btree block
4581 *
4582 * @bp: buffer containing the btree block
4583 * @max_recs: maximum records allowed in this btree node
4584 */
4585 xfs_failaddr_t
xfs_btree_sblock_verify(struct xfs_buf * bp,unsigned int max_recs)4586 xfs_btree_sblock_verify(
4587 struct xfs_buf *bp,
4588 unsigned int max_recs)
4589 {
4590 struct xfs_mount *mp = bp->b_mount;
4591 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
4592 xfs_agnumber_t agno;
4593 xfs_agblock_t agbno;
4594 xfs_failaddr_t fa;
4595
4596 /* numrecs verification */
4597 if (be16_to_cpu(block->bb_numrecs) > max_recs)
4598 return __this_address;
4599
4600 /* sibling pointer verification */
4601 agno = xfs_daddr_to_agno(mp, xfs_buf_daddr(bp));
4602 agbno = xfs_daddr_to_agbno(mp, xfs_buf_daddr(bp));
4603 fa = xfs_btree_check_sblock_siblings(mp, NULL, -1, agno, agbno,
4604 block->bb_u.s.bb_leftsib);
4605 if (!fa)
4606 fa = xfs_btree_check_sblock_siblings(mp, NULL, -1, agno, agbno,
4607 block->bb_u.s.bb_rightsib);
4608 return fa;
4609 }
4610
4611 /*
4612 * Calculate the number of btree levels needed to store a given number of
4613 * records in a short-format btree.
4614 */
4615 uint
xfs_btree_compute_maxlevels(uint * limits,unsigned long len)4616 xfs_btree_compute_maxlevels(
4617 uint *limits,
4618 unsigned long len)
4619 {
4620 uint level;
4621 unsigned long maxblocks;
4622
4623 maxblocks = (len + limits[0] - 1) / limits[0];
4624 for (level = 1; maxblocks > 1; level++)
4625 maxblocks = (maxblocks + limits[1] - 1) / limits[1];
4626 return level;
4627 }
4628
4629 /*
4630 * Query a regular btree for all records overlapping a given interval.
4631 * Start with a LE lookup of the key of low_rec and return all records
4632 * until we find a record with a key greater than the key of high_rec.
4633 */
4634 STATIC int
xfs_btree_simple_query_range(struct xfs_btree_cur * cur,const union xfs_btree_key * low_key,const union xfs_btree_key * high_key,xfs_btree_query_range_fn fn,void * priv)4635 xfs_btree_simple_query_range(
4636 struct xfs_btree_cur *cur,
4637 const union xfs_btree_key *low_key,
4638 const union xfs_btree_key *high_key,
4639 xfs_btree_query_range_fn fn,
4640 void *priv)
4641 {
4642 union xfs_btree_rec *recp;
4643 union xfs_btree_key rec_key;
4644 int64_t diff;
4645 int stat;
4646 bool firstrec = true;
4647 int error;
4648
4649 ASSERT(cur->bc_ops->init_high_key_from_rec);
4650 ASSERT(cur->bc_ops->diff_two_keys);
4651
4652 /*
4653 * Find the leftmost record. The btree cursor must be set
4654 * to the low record used to generate low_key.
4655 */
4656 stat = 0;
4657 error = xfs_btree_lookup(cur, XFS_LOOKUP_LE, &stat);
4658 if (error)
4659 goto out;
4660
4661 /* Nothing? See if there's anything to the right. */
4662 if (!stat) {
4663 error = xfs_btree_increment(cur, 0, &stat);
4664 if (error)
4665 goto out;
4666 }
4667
4668 while (stat) {
4669 /* Find the record. */
4670 error = xfs_btree_get_rec(cur, &recp, &stat);
4671 if (error || !stat)
4672 break;
4673
4674 /* Skip if high_key(rec) < low_key. */
4675 if (firstrec) {
4676 cur->bc_ops->init_high_key_from_rec(&rec_key, recp);
4677 firstrec = false;
4678 diff = cur->bc_ops->diff_two_keys(cur, low_key,
4679 &rec_key);
4680 if (diff > 0)
4681 goto advloop;
4682 }
4683
4684 /* Stop if high_key < low_key(rec). */
4685 cur->bc_ops->init_key_from_rec(&rec_key, recp);
4686 diff = cur->bc_ops->diff_two_keys(cur, &rec_key, high_key);
4687 if (diff > 0)
4688 break;
4689
4690 /* Callback */
4691 error = fn(cur, recp, priv);
4692 if (error)
4693 break;
4694
4695 advloop:
4696 /* Move on to the next record. */
4697 error = xfs_btree_increment(cur, 0, &stat);
4698 if (error)
4699 break;
4700 }
4701
4702 out:
4703 return error;
4704 }
4705
4706 /*
4707 * Query an overlapped interval btree for all records overlapping a given
4708 * interval. This function roughly follows the algorithm given in
4709 * "Interval Trees" of _Introduction to Algorithms_, which is section
4710 * 14.3 in the 2nd and 3rd editions.
4711 *
4712 * First, generate keys for the low and high records passed in.
4713 *
4714 * For any leaf node, generate the high and low keys for the record.
4715 * If the record keys overlap with the query low/high keys, pass the
4716 * record to the function iterator.
4717 *
4718 * For any internal node, compare the low and high keys of each
4719 * pointer against the query low/high keys. If there's an overlap,
4720 * follow the pointer.
4721 *
4722 * As an optimization, we stop scanning a block when we find a low key
4723 * that is greater than the query's high key.
4724 */
4725 STATIC int
xfs_btree_overlapped_query_range(struct xfs_btree_cur * cur,const union xfs_btree_key * low_key,const union xfs_btree_key * high_key,xfs_btree_query_range_fn fn,void * priv)4726 xfs_btree_overlapped_query_range(
4727 struct xfs_btree_cur *cur,
4728 const union xfs_btree_key *low_key,
4729 const union xfs_btree_key *high_key,
4730 xfs_btree_query_range_fn fn,
4731 void *priv)
4732 {
4733 union xfs_btree_ptr ptr;
4734 union xfs_btree_ptr *pp;
4735 union xfs_btree_key rec_key;
4736 union xfs_btree_key rec_hkey;
4737 union xfs_btree_key *lkp;
4738 union xfs_btree_key *hkp;
4739 union xfs_btree_rec *recp;
4740 struct xfs_btree_block *block;
4741 int64_t ldiff;
4742 int64_t hdiff;
4743 int level;
4744 struct xfs_buf *bp;
4745 int i;
4746 int error;
4747
4748 /* Load the root of the btree. */
4749 level = cur->bc_nlevels - 1;
4750 cur->bc_ops->init_ptr_from_cur(cur, &ptr);
4751 error = xfs_btree_lookup_get_block(cur, level, &ptr, &block);
4752 if (error)
4753 return error;
4754 xfs_btree_get_block(cur, level, &bp);
4755 trace_xfs_btree_overlapped_query_range(cur, level, bp);
4756 #ifdef DEBUG
4757 error = xfs_btree_check_block(cur, block, level, bp);
4758 if (error)
4759 goto out;
4760 #endif
4761 cur->bc_ptrs[level] = 1;
4762
4763 while (level < cur->bc_nlevels) {
4764 block = xfs_btree_get_block(cur, level, &bp);
4765
4766 /* End of node, pop back towards the root. */
4767 if (cur->bc_ptrs[level] > be16_to_cpu(block->bb_numrecs)) {
4768 pop_up:
4769 if (level < cur->bc_nlevels - 1)
4770 cur->bc_ptrs[level + 1]++;
4771 level++;
4772 continue;
4773 }
4774
4775 if (level == 0) {
4776 /* Handle a leaf node. */
4777 recp = xfs_btree_rec_addr(cur, cur->bc_ptrs[0], block);
4778
4779 cur->bc_ops->init_high_key_from_rec(&rec_hkey, recp);
4780 ldiff = cur->bc_ops->diff_two_keys(cur, &rec_hkey,
4781 low_key);
4782
4783 cur->bc_ops->init_key_from_rec(&rec_key, recp);
4784 hdiff = cur->bc_ops->diff_two_keys(cur, high_key,
4785 &rec_key);
4786
4787 /*
4788 * If (record's high key >= query's low key) and
4789 * (query's high key >= record's low key), then
4790 * this record overlaps the query range; callback.
4791 */
4792 if (ldiff >= 0 && hdiff >= 0) {
4793 error = fn(cur, recp, priv);
4794 if (error)
4795 break;
4796 } else if (hdiff < 0) {
4797 /* Record is larger than high key; pop. */
4798 goto pop_up;
4799 }
4800 cur->bc_ptrs[level]++;
4801 continue;
4802 }
4803
4804 /* Handle an internal node. */
4805 lkp = xfs_btree_key_addr(cur, cur->bc_ptrs[level], block);
4806 hkp = xfs_btree_high_key_addr(cur, cur->bc_ptrs[level], block);
4807 pp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[level], block);
4808
4809 ldiff = cur->bc_ops->diff_two_keys(cur, hkp, low_key);
4810 hdiff = cur->bc_ops->diff_two_keys(cur, high_key, lkp);
4811
4812 /*
4813 * If (pointer's high key >= query's low key) and
4814 * (query's high key >= pointer's low key), then
4815 * this record overlaps the query range; follow pointer.
4816 */
4817 if (ldiff >= 0 && hdiff >= 0) {
4818 level--;
4819 error = xfs_btree_lookup_get_block(cur, level, pp,
4820 &block);
4821 if (error)
4822 goto out;
4823 xfs_btree_get_block(cur, level, &bp);
4824 trace_xfs_btree_overlapped_query_range(cur, level, bp);
4825 #ifdef DEBUG
4826 error = xfs_btree_check_block(cur, block, level, bp);
4827 if (error)
4828 goto out;
4829 #endif
4830 cur->bc_ptrs[level] = 1;
4831 continue;
4832 } else if (hdiff < 0) {
4833 /* The low key is larger than the upper range; pop. */
4834 goto pop_up;
4835 }
4836 cur->bc_ptrs[level]++;
4837 }
4838
4839 out:
4840 /*
4841 * If we don't end this function with the cursor pointing at a record
4842 * block, a subsequent non-error cursor deletion will not release
4843 * node-level buffers, causing a buffer leak. This is quite possible
4844 * with a zero-results range query, so release the buffers if we
4845 * failed to return any results.
4846 */
4847 if (cur->bc_bufs[0] == NULL) {
4848 for (i = 0; i < cur->bc_nlevels; i++) {
4849 if (cur->bc_bufs[i]) {
4850 xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[i]);
4851 cur->bc_bufs[i] = NULL;
4852 cur->bc_ptrs[i] = 0;
4853 cur->bc_ra[i] = 0;
4854 }
4855 }
4856 }
4857
4858 return error;
4859 }
4860
4861 /*
4862 * Query a btree for all records overlapping a given interval of keys. The
4863 * supplied function will be called with each record found; return one of the
4864 * XFS_BTREE_QUERY_RANGE_{CONTINUE,ABORT} values or the usual negative error
4865 * code. This function returns -ECANCELED, zero, or a negative error code.
4866 */
4867 int
xfs_btree_query_range(struct xfs_btree_cur * cur,const union xfs_btree_irec * low_rec,const union xfs_btree_irec * high_rec,xfs_btree_query_range_fn fn,void * priv)4868 xfs_btree_query_range(
4869 struct xfs_btree_cur *cur,
4870 const union xfs_btree_irec *low_rec,
4871 const union xfs_btree_irec *high_rec,
4872 xfs_btree_query_range_fn fn,
4873 void *priv)
4874 {
4875 union xfs_btree_rec rec;
4876 union xfs_btree_key low_key;
4877 union xfs_btree_key high_key;
4878
4879 /* Find the keys of both ends of the interval. */
4880 cur->bc_rec = *high_rec;
4881 cur->bc_ops->init_rec_from_cur(cur, &rec);
4882 cur->bc_ops->init_key_from_rec(&high_key, &rec);
4883
4884 cur->bc_rec = *low_rec;
4885 cur->bc_ops->init_rec_from_cur(cur, &rec);
4886 cur->bc_ops->init_key_from_rec(&low_key, &rec);
4887
4888 /* Enforce low key < high key. */
4889 if (cur->bc_ops->diff_two_keys(cur, &low_key, &high_key) > 0)
4890 return -EINVAL;
4891
4892 if (!(cur->bc_flags & XFS_BTREE_OVERLAPPING))
4893 return xfs_btree_simple_query_range(cur, &low_key,
4894 &high_key, fn, priv);
4895 return xfs_btree_overlapped_query_range(cur, &low_key, &high_key,
4896 fn, priv);
4897 }
4898
4899 /* Query a btree for all records. */
4900 int
xfs_btree_query_all(struct xfs_btree_cur * cur,xfs_btree_query_range_fn fn,void * priv)4901 xfs_btree_query_all(
4902 struct xfs_btree_cur *cur,
4903 xfs_btree_query_range_fn fn,
4904 void *priv)
4905 {
4906 union xfs_btree_key low_key;
4907 union xfs_btree_key high_key;
4908
4909 memset(&cur->bc_rec, 0, sizeof(cur->bc_rec));
4910 memset(&low_key, 0, sizeof(low_key));
4911 memset(&high_key, 0xFF, sizeof(high_key));
4912
4913 return xfs_btree_simple_query_range(cur, &low_key, &high_key, fn, priv);
4914 }
4915
4916 /*
4917 * Calculate the number of blocks needed to store a given number of records
4918 * in a short-format (per-AG metadata) btree.
4919 */
4920 unsigned long long
xfs_btree_calc_size(uint * limits,unsigned long long len)4921 xfs_btree_calc_size(
4922 uint *limits,
4923 unsigned long long len)
4924 {
4925 int level;
4926 int maxrecs;
4927 unsigned long long rval;
4928
4929 maxrecs = limits[0];
4930 for (level = 0, rval = 0; len > 1; level++) {
4931 len += maxrecs - 1;
4932 do_div(len, maxrecs);
4933 maxrecs = limits[1];
4934 rval += len;
4935 }
4936 return rval;
4937 }
4938
4939 static int
xfs_btree_count_blocks_helper(struct xfs_btree_cur * cur,int level,void * data)4940 xfs_btree_count_blocks_helper(
4941 struct xfs_btree_cur *cur,
4942 int level,
4943 void *data)
4944 {
4945 xfs_extlen_t *blocks = data;
4946 (*blocks)++;
4947
4948 return 0;
4949 }
4950
4951 /* Count the blocks in a btree and return the result in *blocks. */
4952 int
xfs_btree_count_blocks(struct xfs_btree_cur * cur,xfs_extlen_t * blocks)4953 xfs_btree_count_blocks(
4954 struct xfs_btree_cur *cur,
4955 xfs_extlen_t *blocks)
4956 {
4957 *blocks = 0;
4958 return xfs_btree_visit_blocks(cur, xfs_btree_count_blocks_helper,
4959 XFS_BTREE_VISIT_ALL, blocks);
4960 }
4961
4962 /* Compare two btree pointers. */
4963 int64_t
xfs_btree_diff_two_ptrs(struct xfs_btree_cur * cur,const union xfs_btree_ptr * a,const union xfs_btree_ptr * b)4964 xfs_btree_diff_two_ptrs(
4965 struct xfs_btree_cur *cur,
4966 const union xfs_btree_ptr *a,
4967 const union xfs_btree_ptr *b)
4968 {
4969 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
4970 return (int64_t)be64_to_cpu(a->l) - be64_to_cpu(b->l);
4971 return (int64_t)be32_to_cpu(a->s) - be32_to_cpu(b->s);
4972 }
4973
4974 /* If there's an extent, we're done. */
4975 STATIC int
xfs_btree_has_record_helper(struct xfs_btree_cur * cur,const union xfs_btree_rec * rec,void * priv)4976 xfs_btree_has_record_helper(
4977 struct xfs_btree_cur *cur,
4978 const union xfs_btree_rec *rec,
4979 void *priv)
4980 {
4981 return -ECANCELED;
4982 }
4983
4984 /* Is there a record covering a given range of keys? */
4985 int
xfs_btree_has_record(struct xfs_btree_cur * cur,const union xfs_btree_irec * low,const union xfs_btree_irec * high,bool * exists)4986 xfs_btree_has_record(
4987 struct xfs_btree_cur *cur,
4988 const union xfs_btree_irec *low,
4989 const union xfs_btree_irec *high,
4990 bool *exists)
4991 {
4992 int error;
4993
4994 error = xfs_btree_query_range(cur, low, high,
4995 &xfs_btree_has_record_helper, NULL);
4996 if (error == -ECANCELED) {
4997 *exists = true;
4998 return 0;
4999 }
5000 *exists = false;
5001 return error;
5002 }
5003
5004 /* Are there more records in this btree? */
5005 bool
xfs_btree_has_more_records(struct xfs_btree_cur * cur)5006 xfs_btree_has_more_records(
5007 struct xfs_btree_cur *cur)
5008 {
5009 struct xfs_btree_block *block;
5010 struct xfs_buf *bp;
5011
5012 block = xfs_btree_get_block(cur, 0, &bp);
5013
5014 /* There are still records in this block. */
5015 if (cur->bc_ptrs[0] < xfs_btree_get_numrecs(block))
5016 return true;
5017
5018 /* There are more record blocks. */
5019 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
5020 return block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK);
5021 else
5022 return block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK);
5023 }
5024