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 #include "xfs_alloc_btree.h"
26 #include "xfs_ialloc_btree.h"
27 #include "xfs_bmap_btree.h"
28 #include "xfs_rmap_btree.h"
29 #include "xfs_refcount_btree.h"
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_perag * pag,struct xfs_btree_cur * cur,int level,xfs_agblock_t agbno,__be32 dsibling)93 xfs_btree_check_sblock_siblings(
94 struct xfs_perag *pag,
95 struct xfs_btree_cur *cur,
96 int level,
97 xfs_agblock_t agbno,
98 __be32 dsibling)
99 {
100 xfs_agblock_t sibling;
101
102 if (dsibling == cpu_to_be32(NULLAGBLOCK))
103 return NULL;
104
105 sibling = be32_to_cpu(dsibling);
106 if (sibling == agbno)
107 return __this_address;
108 if (level >= 0) {
109 if (!xfs_btree_check_sptr(cur, sibling, level + 1))
110 return __this_address;
111 } else {
112 if (!xfs_verify_agbno(pag, sibling))
113 return __this_address;
114 }
115 return NULL;
116 }
117
118 /*
119 * Check a long btree block header. Return the address of the failing check,
120 * or NULL if everything is ok.
121 */
122 xfs_failaddr_t
__xfs_btree_check_lblock(struct xfs_btree_cur * cur,struct xfs_btree_block * block,int level,struct xfs_buf * bp)123 __xfs_btree_check_lblock(
124 struct xfs_btree_cur *cur,
125 struct xfs_btree_block *block,
126 int level,
127 struct xfs_buf *bp)
128 {
129 struct xfs_mount *mp = cur->bc_mp;
130 xfs_btnum_t btnum = cur->bc_btnum;
131 int crc = xfs_has_crc(mp);
132 xfs_failaddr_t fa;
133 xfs_fsblock_t fsb = NULLFSBLOCK;
134
135 if (crc) {
136 if (!uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid))
137 return __this_address;
138 if (block->bb_u.l.bb_blkno !=
139 cpu_to_be64(bp ? xfs_buf_daddr(bp) : XFS_BUF_DADDR_NULL))
140 return __this_address;
141 if (block->bb_u.l.bb_pad != cpu_to_be32(0))
142 return __this_address;
143 }
144
145 if (be32_to_cpu(block->bb_magic) != xfs_btree_magic(crc, btnum))
146 return __this_address;
147 if (be16_to_cpu(block->bb_level) != level)
148 return __this_address;
149 if (be16_to_cpu(block->bb_numrecs) >
150 cur->bc_ops->get_maxrecs(cur, level))
151 return __this_address;
152
153 if (bp)
154 fsb = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp));
155
156 fa = xfs_btree_check_lblock_siblings(mp, cur, level, fsb,
157 block->bb_u.l.bb_leftsib);
158 if (!fa)
159 fa = xfs_btree_check_lblock_siblings(mp, cur, level, fsb,
160 block->bb_u.l.bb_rightsib);
161 return fa;
162 }
163
164 /* Check a long btree block header. */
165 static int
xfs_btree_check_lblock(struct xfs_btree_cur * cur,struct xfs_btree_block * block,int level,struct xfs_buf * bp)166 xfs_btree_check_lblock(
167 struct xfs_btree_cur *cur,
168 struct xfs_btree_block *block,
169 int level,
170 struct xfs_buf *bp)
171 {
172 struct xfs_mount *mp = cur->bc_mp;
173 xfs_failaddr_t fa;
174
175 fa = __xfs_btree_check_lblock(cur, block, level, bp);
176 if (XFS_IS_CORRUPT(mp, fa != NULL) ||
177 XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BTREE_CHECK_LBLOCK)) {
178 if (bp)
179 trace_xfs_btree_corrupt(bp, _RET_IP_);
180 return -EFSCORRUPTED;
181 }
182 return 0;
183 }
184
185 /*
186 * Check a short btree block header. Return the address of the failing check,
187 * or NULL if everything is ok.
188 */
189 xfs_failaddr_t
__xfs_btree_check_sblock(struct xfs_btree_cur * cur,struct xfs_btree_block * block,int level,struct xfs_buf * bp)190 __xfs_btree_check_sblock(
191 struct xfs_btree_cur *cur,
192 struct xfs_btree_block *block,
193 int level,
194 struct xfs_buf *bp)
195 {
196 struct xfs_mount *mp = cur->bc_mp;
197 struct xfs_perag *pag = cur->bc_ag.pag;
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
203 if (crc) {
204 if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid))
205 return __this_address;
206 if (block->bb_u.s.bb_blkno !=
207 cpu_to_be64(bp ? xfs_buf_daddr(bp) : XFS_BUF_DADDR_NULL))
208 return __this_address;
209 }
210
211 if (be32_to_cpu(block->bb_magic) != xfs_btree_magic(crc, btnum))
212 return __this_address;
213 if (be16_to_cpu(block->bb_level) != level)
214 return __this_address;
215 if (be16_to_cpu(block->bb_numrecs) >
216 cur->bc_ops->get_maxrecs(cur, level))
217 return __this_address;
218
219 if (bp)
220 agbno = xfs_daddr_to_agbno(mp, xfs_buf_daddr(bp));
221
222 fa = xfs_btree_check_sblock_siblings(pag, cur, level, agbno,
223 block->bb_u.s.bb_leftsib);
224 if (!fa)
225 fa = xfs_btree_check_sblock_siblings(pag, cur, level, agbno,
226 block->bb_u.s.bb_rightsib);
227 return fa;
228 }
229
230 /* Check a short btree block header. */
231 STATIC int
xfs_btree_check_sblock(struct xfs_btree_cur * cur,struct xfs_btree_block * block,int level,struct xfs_buf * bp)232 xfs_btree_check_sblock(
233 struct xfs_btree_cur *cur,
234 struct xfs_btree_block *block,
235 int level,
236 struct xfs_buf *bp)
237 {
238 struct xfs_mount *mp = cur->bc_mp;
239 xfs_failaddr_t fa;
240
241 fa = __xfs_btree_check_sblock(cur, block, level, bp);
242 if (XFS_IS_CORRUPT(mp, fa != NULL) ||
243 XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BTREE_CHECK_SBLOCK)) {
244 if (bp)
245 trace_xfs_btree_corrupt(bp, _RET_IP_);
246 return -EFSCORRUPTED;
247 }
248 return 0;
249 }
250
251 /*
252 * Debug routine: check that block header is ok.
253 */
254 int
xfs_btree_check_block(struct xfs_btree_cur * cur,struct xfs_btree_block * block,int level,struct xfs_buf * bp)255 xfs_btree_check_block(
256 struct xfs_btree_cur *cur, /* btree cursor */
257 struct xfs_btree_block *block, /* generic btree block pointer */
258 int level, /* level of the btree block */
259 struct xfs_buf *bp) /* buffer containing block, if any */
260 {
261 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
262 return xfs_btree_check_lblock(cur, block, level, bp);
263 else
264 return xfs_btree_check_sblock(cur, block, level, bp);
265 }
266
267 /* Check that this long pointer is valid and points within the fs. */
268 bool
xfs_btree_check_lptr(struct xfs_btree_cur * cur,xfs_fsblock_t fsbno,int level)269 xfs_btree_check_lptr(
270 struct xfs_btree_cur *cur,
271 xfs_fsblock_t fsbno,
272 int level)
273 {
274 if (level <= 0)
275 return false;
276 return xfs_verify_fsbno(cur->bc_mp, fsbno);
277 }
278
279 /* Check that this short pointer is valid and points within the AG. */
280 bool
xfs_btree_check_sptr(struct xfs_btree_cur * cur,xfs_agblock_t agbno,int level)281 xfs_btree_check_sptr(
282 struct xfs_btree_cur *cur,
283 xfs_agblock_t agbno,
284 int level)
285 {
286 if (level <= 0)
287 return false;
288 return xfs_verify_agbno(cur->bc_ag.pag, agbno);
289 }
290
291 /*
292 * Check that a given (indexed) btree pointer at a certain level of a
293 * btree is valid and doesn't point past where it should.
294 */
295 static int
xfs_btree_check_ptr(struct xfs_btree_cur * cur,const union xfs_btree_ptr * ptr,int index,int level)296 xfs_btree_check_ptr(
297 struct xfs_btree_cur *cur,
298 const union xfs_btree_ptr *ptr,
299 int index,
300 int level)
301 {
302 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
303 if (xfs_btree_check_lptr(cur, be64_to_cpu((&ptr->l)[index]),
304 level))
305 return 0;
306 xfs_err(cur->bc_mp,
307 "Inode %llu fork %d: Corrupt btree %d pointer at level %d index %d.",
308 cur->bc_ino.ip->i_ino,
309 cur->bc_ino.whichfork, cur->bc_btnum,
310 level, index);
311 } else {
312 if (xfs_btree_check_sptr(cur, be32_to_cpu((&ptr->s)[index]),
313 level))
314 return 0;
315 xfs_err(cur->bc_mp,
316 "AG %u: Corrupt btree %d pointer at level %d index %d.",
317 cur->bc_ag.pag->pag_agno, cur->bc_btnum,
318 level, index);
319 }
320
321 return -EFSCORRUPTED;
322 }
323
324 #ifdef DEBUG
325 # define xfs_btree_debug_check_ptr xfs_btree_check_ptr
326 #else
327 # define xfs_btree_debug_check_ptr(...) (0)
328 #endif
329
330 /*
331 * Calculate CRC on the whole btree block and stuff it into the
332 * long-form btree header.
333 *
334 * Prior to calculting the CRC, pull the LSN out of the buffer log item and put
335 * it into the buffer so recovery knows what the last modification was that made
336 * it to disk.
337 */
338 void
xfs_btree_lblock_calc_crc(struct xfs_buf * bp)339 xfs_btree_lblock_calc_crc(
340 struct xfs_buf *bp)
341 {
342 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
343 struct xfs_buf_log_item *bip = bp->b_log_item;
344
345 if (!xfs_has_crc(bp->b_mount))
346 return;
347 if (bip)
348 block->bb_u.l.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
349 xfs_buf_update_cksum(bp, XFS_BTREE_LBLOCK_CRC_OFF);
350 }
351
352 bool
xfs_btree_lblock_verify_crc(struct xfs_buf * bp)353 xfs_btree_lblock_verify_crc(
354 struct xfs_buf *bp)
355 {
356 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
357 struct xfs_mount *mp = bp->b_mount;
358
359 if (xfs_has_crc(mp)) {
360 if (!xfs_log_check_lsn(mp, be64_to_cpu(block->bb_u.l.bb_lsn)))
361 return false;
362 return xfs_buf_verify_cksum(bp, XFS_BTREE_LBLOCK_CRC_OFF);
363 }
364
365 return true;
366 }
367
368 /*
369 * Calculate CRC on the whole btree block and stuff it into the
370 * short-form btree header.
371 *
372 * Prior to calculting the CRC, pull the LSN out of the buffer log item and put
373 * it into the buffer so recovery knows what the last modification was that made
374 * it to disk.
375 */
376 void
xfs_btree_sblock_calc_crc(struct xfs_buf * bp)377 xfs_btree_sblock_calc_crc(
378 struct xfs_buf *bp)
379 {
380 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
381 struct xfs_buf_log_item *bip = bp->b_log_item;
382
383 if (!xfs_has_crc(bp->b_mount))
384 return;
385 if (bip)
386 block->bb_u.s.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
387 xfs_buf_update_cksum(bp, XFS_BTREE_SBLOCK_CRC_OFF);
388 }
389
390 bool
xfs_btree_sblock_verify_crc(struct xfs_buf * bp)391 xfs_btree_sblock_verify_crc(
392 struct xfs_buf *bp)
393 {
394 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
395 struct xfs_mount *mp = bp->b_mount;
396
397 if (xfs_has_crc(mp)) {
398 if (!xfs_log_check_lsn(mp, be64_to_cpu(block->bb_u.s.bb_lsn)))
399 return false;
400 return xfs_buf_verify_cksum(bp, XFS_BTREE_SBLOCK_CRC_OFF);
401 }
402
403 return true;
404 }
405
406 static int
xfs_btree_free_block(struct xfs_btree_cur * cur,struct xfs_buf * bp)407 xfs_btree_free_block(
408 struct xfs_btree_cur *cur,
409 struct xfs_buf *bp)
410 {
411 int error;
412
413 error = cur->bc_ops->free_block(cur, bp);
414 if (!error) {
415 xfs_trans_binval(cur->bc_tp, bp);
416 XFS_BTREE_STATS_INC(cur, free);
417 }
418 return error;
419 }
420
421 /*
422 * Delete the btree cursor.
423 */
424 void
xfs_btree_del_cursor(struct xfs_btree_cur * cur,int error)425 xfs_btree_del_cursor(
426 struct xfs_btree_cur *cur, /* btree cursor */
427 int error) /* del because of error */
428 {
429 int i; /* btree level */
430
431 /*
432 * Clear the buffer pointers and release the buffers. If we're doing
433 * this because of an error, inspect all of the entries in the bc_bufs
434 * array for buffers to be unlocked. This is because some of the btree
435 * code works from level n down to 0, and if we get an error along the
436 * way we won't have initialized all the entries down to 0.
437 */
438 for (i = 0; i < cur->bc_nlevels; i++) {
439 if (cur->bc_levels[i].bp)
440 xfs_trans_brelse(cur->bc_tp, cur->bc_levels[i].bp);
441 else if (!error)
442 break;
443 }
444
445 /*
446 * If we are doing a BMBT update, the number of unaccounted blocks
447 * allocated during this cursor life time should be zero. If it's not
448 * zero, then we should be shut down or on our way to shutdown due to
449 * cancelling a dirty transaction on error.
450 */
451 ASSERT(cur->bc_btnum != XFS_BTNUM_BMAP || cur->bc_ino.allocated == 0 ||
452 xfs_is_shutdown(cur->bc_mp) || error != 0);
453 if (unlikely(cur->bc_flags & XFS_BTREE_STAGING))
454 kmem_free(cur->bc_ops);
455 if (!(cur->bc_flags & XFS_BTREE_LONG_PTRS) && cur->bc_ag.pag)
456 xfs_perag_put(cur->bc_ag.pag);
457 kmem_cache_free(cur->bc_cache, cur);
458 }
459
460 /*
461 * Duplicate the btree cursor.
462 * Allocate a new one, copy the record, re-get the buffers.
463 */
464 int /* error */
xfs_btree_dup_cursor(struct xfs_btree_cur * cur,struct xfs_btree_cur ** ncur)465 xfs_btree_dup_cursor(
466 struct xfs_btree_cur *cur, /* input cursor */
467 struct xfs_btree_cur **ncur) /* output cursor */
468 {
469 struct xfs_buf *bp; /* btree block's buffer pointer */
470 int error; /* error return value */
471 int i; /* level number of btree block */
472 xfs_mount_t *mp; /* mount structure for filesystem */
473 struct xfs_btree_cur *new; /* new cursor value */
474 xfs_trans_t *tp; /* transaction pointer, can be NULL */
475
476 tp = cur->bc_tp;
477 mp = cur->bc_mp;
478
479 /*
480 * Allocate a new cursor like the old one.
481 */
482 new = cur->bc_ops->dup_cursor(cur);
483
484 /*
485 * Copy the record currently in the cursor.
486 */
487 new->bc_rec = cur->bc_rec;
488
489 /*
490 * For each level current, re-get the buffer and copy the ptr value.
491 */
492 for (i = 0; i < new->bc_nlevels; i++) {
493 new->bc_levels[i].ptr = cur->bc_levels[i].ptr;
494 new->bc_levels[i].ra = cur->bc_levels[i].ra;
495 bp = cur->bc_levels[i].bp;
496 if (bp) {
497 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
498 xfs_buf_daddr(bp), mp->m_bsize,
499 0, &bp,
500 cur->bc_ops->buf_ops);
501 if (error) {
502 xfs_btree_del_cursor(new, error);
503 *ncur = NULL;
504 return error;
505 }
506 }
507 new->bc_levels[i].bp = bp;
508 }
509 *ncur = new;
510 return 0;
511 }
512
513 /*
514 * XFS btree block layout and addressing:
515 *
516 * There are two types of blocks in the btree: leaf and non-leaf blocks.
517 *
518 * The leaf record start with a header then followed by records containing
519 * the values. A non-leaf block also starts with the same header, and
520 * then first contains lookup keys followed by an equal number of pointers
521 * to the btree blocks at the previous level.
522 *
523 * +--------+-------+-------+-------+-------+-------+-------+
524 * Leaf: | header | rec 1 | rec 2 | rec 3 | rec 4 | rec 5 | rec N |
525 * +--------+-------+-------+-------+-------+-------+-------+
526 *
527 * +--------+-------+-------+-------+-------+-------+-------+
528 * Non-Leaf: | header | key 1 | key 2 | key N | ptr 1 | ptr 2 | ptr N |
529 * +--------+-------+-------+-------+-------+-------+-------+
530 *
531 * The header is called struct xfs_btree_block for reasons better left unknown
532 * and comes in different versions for short (32bit) and long (64bit) block
533 * pointers. The record and key structures are defined by the btree instances
534 * and opaque to the btree core. The block pointers are simple disk endian
535 * integers, available in a short (32bit) and long (64bit) variant.
536 *
537 * The helpers below calculate the offset of a given record, key or pointer
538 * into a btree block (xfs_btree_*_offset) or return a pointer to the given
539 * record, key or pointer (xfs_btree_*_addr). Note that all addressing
540 * inside the btree block is done using indices starting at one, not zero!
541 *
542 * If XFS_BTREE_OVERLAPPING is set, then this btree supports keys containing
543 * overlapping intervals. In such a tree, records are still sorted lowest to
544 * highest and indexed by the smallest key value that refers to the record.
545 * However, nodes are different: each pointer has two associated keys -- one
546 * indexing the lowest key available in the block(s) below (the same behavior
547 * as the key in a regular btree) and another indexing the highest key
548 * available in the block(s) below. Because records are /not/ sorted by the
549 * highest key, all leaf block updates require us to compute the highest key
550 * that matches any record in the leaf and to recursively update the high keys
551 * in the nodes going further up in the tree, if necessary. Nodes look like
552 * this:
553 *
554 * +--------+-----+-----+-----+-----+-----+-------+-------+-----+
555 * Non-Leaf: | header | lo1 | hi1 | lo2 | hi2 | ... | ptr 1 | ptr 2 | ... |
556 * +--------+-----+-----+-----+-----+-----+-------+-------+-----+
557 *
558 * To perform an interval query on an overlapped tree, perform the usual
559 * depth-first search and use the low and high keys to decide if we can skip
560 * that particular node. If a leaf node is reached, return the records that
561 * intersect the interval. Note that an interval query may return numerous
562 * entries. For a non-overlapped tree, simply search for the record associated
563 * with the lowest key and iterate forward until a non-matching record is
564 * found. Section 14.3 ("Interval Trees") of _Introduction to Algorithms_ by
565 * Cormen, Leiserson, Rivest, and Stein (2nd or 3rd ed. only) discuss this in
566 * more detail.
567 *
568 * Why do we care about overlapping intervals? Let's say you have a bunch of
569 * reverse mapping records on a reflink filesystem:
570 *
571 * 1: +- file A startblock B offset C length D -----------+
572 * 2: +- file E startblock F offset G length H --------------+
573 * 3: +- file I startblock F offset J length K --+
574 * 4: +- file L... --+
575 *
576 * Now say we want to map block (B+D) into file A at offset (C+D). Ideally,
577 * we'd simply increment the length of record 1. But how do we find the record
578 * that ends at (B+D-1) (i.e. record 1)? A LE lookup of (B+D-1) would return
579 * record 3 because the keys are ordered first by startblock. An interval
580 * query would return records 1 and 2 because they both overlap (B+D-1), and
581 * from that we can pick out record 1 as the appropriate left neighbor.
582 *
583 * In the non-overlapped case you can do a LE lookup and decrement the cursor
584 * because a record's interval must end before the next record.
585 */
586
587 /*
588 * Return size of the btree block header for this btree instance.
589 */
xfs_btree_block_len(struct xfs_btree_cur * cur)590 static inline size_t xfs_btree_block_len(struct xfs_btree_cur *cur)
591 {
592 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
593 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
594 return XFS_BTREE_LBLOCK_CRC_LEN;
595 return XFS_BTREE_LBLOCK_LEN;
596 }
597 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
598 return XFS_BTREE_SBLOCK_CRC_LEN;
599 return XFS_BTREE_SBLOCK_LEN;
600 }
601
602 /*
603 * Return size of btree block pointers for this btree instance.
604 */
xfs_btree_ptr_len(struct xfs_btree_cur * cur)605 static inline size_t xfs_btree_ptr_len(struct xfs_btree_cur *cur)
606 {
607 return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
608 sizeof(__be64) : sizeof(__be32);
609 }
610
611 /*
612 * Calculate offset of the n-th record in a btree block.
613 */
614 STATIC size_t
xfs_btree_rec_offset(struct xfs_btree_cur * cur,int n)615 xfs_btree_rec_offset(
616 struct xfs_btree_cur *cur,
617 int n)
618 {
619 return xfs_btree_block_len(cur) +
620 (n - 1) * cur->bc_ops->rec_len;
621 }
622
623 /*
624 * Calculate offset of the n-th key in a btree block.
625 */
626 STATIC size_t
xfs_btree_key_offset(struct xfs_btree_cur * cur,int n)627 xfs_btree_key_offset(
628 struct xfs_btree_cur *cur,
629 int n)
630 {
631 return xfs_btree_block_len(cur) +
632 (n - 1) * cur->bc_ops->key_len;
633 }
634
635 /*
636 * Calculate offset of the n-th high key in a btree block.
637 */
638 STATIC size_t
xfs_btree_high_key_offset(struct xfs_btree_cur * cur,int n)639 xfs_btree_high_key_offset(
640 struct xfs_btree_cur *cur,
641 int n)
642 {
643 return xfs_btree_block_len(cur) +
644 (n - 1) * cur->bc_ops->key_len + (cur->bc_ops->key_len / 2);
645 }
646
647 /*
648 * Calculate offset of the n-th block pointer in a btree block.
649 */
650 STATIC size_t
xfs_btree_ptr_offset(struct xfs_btree_cur * cur,int n,int level)651 xfs_btree_ptr_offset(
652 struct xfs_btree_cur *cur,
653 int n,
654 int level)
655 {
656 return xfs_btree_block_len(cur) +
657 cur->bc_ops->get_maxrecs(cur, level) * cur->bc_ops->key_len +
658 (n - 1) * xfs_btree_ptr_len(cur);
659 }
660
661 /*
662 * Return a pointer to the n-th record in the btree block.
663 */
664 union xfs_btree_rec *
xfs_btree_rec_addr(struct xfs_btree_cur * cur,int n,struct xfs_btree_block * block)665 xfs_btree_rec_addr(
666 struct xfs_btree_cur *cur,
667 int n,
668 struct xfs_btree_block *block)
669 {
670 return (union xfs_btree_rec *)
671 ((char *)block + xfs_btree_rec_offset(cur, n));
672 }
673
674 /*
675 * Return a pointer to the n-th key in the btree block.
676 */
677 union xfs_btree_key *
xfs_btree_key_addr(struct xfs_btree_cur * cur,int n,struct xfs_btree_block * block)678 xfs_btree_key_addr(
679 struct xfs_btree_cur *cur,
680 int n,
681 struct xfs_btree_block *block)
682 {
683 return (union xfs_btree_key *)
684 ((char *)block + xfs_btree_key_offset(cur, n));
685 }
686
687 /*
688 * Return a pointer to the n-th high key in the btree block.
689 */
690 union xfs_btree_key *
xfs_btree_high_key_addr(struct xfs_btree_cur * cur,int n,struct xfs_btree_block * block)691 xfs_btree_high_key_addr(
692 struct xfs_btree_cur *cur,
693 int n,
694 struct xfs_btree_block *block)
695 {
696 return (union xfs_btree_key *)
697 ((char *)block + xfs_btree_high_key_offset(cur, n));
698 }
699
700 /*
701 * Return a pointer to the n-th block pointer in the btree block.
702 */
703 union xfs_btree_ptr *
xfs_btree_ptr_addr(struct xfs_btree_cur * cur,int n,struct xfs_btree_block * block)704 xfs_btree_ptr_addr(
705 struct xfs_btree_cur *cur,
706 int n,
707 struct xfs_btree_block *block)
708 {
709 int level = xfs_btree_get_level(block);
710
711 ASSERT(block->bb_level != 0);
712
713 return (union xfs_btree_ptr *)
714 ((char *)block + xfs_btree_ptr_offset(cur, n, level));
715 }
716
717 struct xfs_ifork *
xfs_btree_ifork_ptr(struct xfs_btree_cur * cur)718 xfs_btree_ifork_ptr(
719 struct xfs_btree_cur *cur)
720 {
721 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
722
723 if (cur->bc_flags & XFS_BTREE_STAGING)
724 return cur->bc_ino.ifake->if_fork;
725 return xfs_ifork_ptr(cur->bc_ino.ip, cur->bc_ino.whichfork);
726 }
727
728 /*
729 * Get the root block which is stored in the inode.
730 *
731 * For now this btree implementation assumes the btree root is always
732 * stored in the if_broot field of an inode fork.
733 */
734 STATIC struct xfs_btree_block *
xfs_btree_get_iroot(struct xfs_btree_cur * cur)735 xfs_btree_get_iroot(
736 struct xfs_btree_cur *cur)
737 {
738 struct xfs_ifork *ifp = xfs_btree_ifork_ptr(cur);
739
740 return (struct xfs_btree_block *)ifp->if_broot;
741 }
742
743 /*
744 * Retrieve the block pointer from the cursor at the given level.
745 * This may be an inode btree root or from a buffer.
746 */
747 struct xfs_btree_block * /* generic btree block pointer */
xfs_btree_get_block(struct xfs_btree_cur * cur,int level,struct xfs_buf ** bpp)748 xfs_btree_get_block(
749 struct xfs_btree_cur *cur, /* btree cursor */
750 int level, /* level in btree */
751 struct xfs_buf **bpp) /* buffer containing the block */
752 {
753 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
754 (level == cur->bc_nlevels - 1)) {
755 *bpp = NULL;
756 return xfs_btree_get_iroot(cur);
757 }
758
759 *bpp = cur->bc_levels[level].bp;
760 return XFS_BUF_TO_BLOCK(*bpp);
761 }
762
763 /*
764 * Change the cursor to point to the first record at the given level.
765 * Other levels are unaffected.
766 */
767 STATIC int /* success=1, failure=0 */
xfs_btree_firstrec(struct xfs_btree_cur * cur,int level)768 xfs_btree_firstrec(
769 struct xfs_btree_cur *cur, /* btree cursor */
770 int level) /* level to change */
771 {
772 struct xfs_btree_block *block; /* generic btree block pointer */
773 struct xfs_buf *bp; /* buffer containing block */
774
775 /*
776 * Get the block pointer for this level.
777 */
778 block = xfs_btree_get_block(cur, level, &bp);
779 if (xfs_btree_check_block(cur, block, level, bp))
780 return 0;
781 /*
782 * It's empty, there is no such record.
783 */
784 if (!block->bb_numrecs)
785 return 0;
786 /*
787 * Set the ptr value to 1, that's the first record/key.
788 */
789 cur->bc_levels[level].ptr = 1;
790 return 1;
791 }
792
793 /*
794 * Change the cursor to point to the last record in the current block
795 * at the given level. Other levels are unaffected.
796 */
797 STATIC int /* success=1, failure=0 */
xfs_btree_lastrec(struct xfs_btree_cur * cur,int level)798 xfs_btree_lastrec(
799 struct xfs_btree_cur *cur, /* btree cursor */
800 int level) /* level to change */
801 {
802 struct xfs_btree_block *block; /* generic btree block pointer */
803 struct xfs_buf *bp; /* buffer containing block */
804
805 /*
806 * Get the block pointer for this level.
807 */
808 block = xfs_btree_get_block(cur, level, &bp);
809 if (xfs_btree_check_block(cur, block, level, bp))
810 return 0;
811 /*
812 * It's empty, there is no such record.
813 */
814 if (!block->bb_numrecs)
815 return 0;
816 /*
817 * Set the ptr value to numrecs, that's the last record/key.
818 */
819 cur->bc_levels[level].ptr = be16_to_cpu(block->bb_numrecs);
820 return 1;
821 }
822
823 /*
824 * Compute first and last byte offsets for the fields given.
825 * Interprets the offsets table, which contains struct field offsets.
826 */
827 void
xfs_btree_offsets(uint32_t fields,const short * offsets,int nbits,int * first,int * last)828 xfs_btree_offsets(
829 uint32_t fields, /* bitmask of fields */
830 const short *offsets, /* table of field offsets */
831 int nbits, /* number of bits to inspect */
832 int *first, /* output: first byte offset */
833 int *last) /* output: last byte offset */
834 {
835 int i; /* current bit number */
836 uint32_t imask; /* mask for current bit number */
837
838 ASSERT(fields != 0);
839 /*
840 * Find the lowest bit, so the first byte offset.
841 */
842 for (i = 0, imask = 1u; ; i++, imask <<= 1) {
843 if (imask & fields) {
844 *first = offsets[i];
845 break;
846 }
847 }
848 /*
849 * Find the highest bit, so the last byte offset.
850 */
851 for (i = nbits - 1, imask = 1u << i; ; i--, imask >>= 1) {
852 if (imask & fields) {
853 *last = offsets[i + 1] - 1;
854 break;
855 }
856 }
857 }
858
859 /*
860 * Get a buffer for the block, return it read in.
861 * Long-form addressing.
862 */
863 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)864 xfs_btree_read_bufl(
865 struct xfs_mount *mp, /* file system mount point */
866 struct xfs_trans *tp, /* transaction pointer */
867 xfs_fsblock_t fsbno, /* file system block number */
868 struct xfs_buf **bpp, /* buffer for fsbno */
869 int refval, /* ref count value for buffer */
870 const struct xfs_buf_ops *ops)
871 {
872 struct xfs_buf *bp; /* return value */
873 xfs_daddr_t d; /* real disk block address */
874 int error;
875
876 if (!xfs_verify_fsbno(mp, fsbno))
877 return -EFSCORRUPTED;
878 d = XFS_FSB_TO_DADDR(mp, fsbno);
879 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
880 mp->m_bsize, 0, &bp, ops);
881 if (error)
882 return error;
883 if (bp)
884 xfs_buf_set_ref(bp, refval);
885 *bpp = bp;
886 return 0;
887 }
888
889 /*
890 * Read-ahead the block, don't wait for it, don't return a buffer.
891 * Long-form addressing.
892 */
893 /* ARGSUSED */
894 void
xfs_btree_reada_bufl(struct xfs_mount * mp,xfs_fsblock_t fsbno,xfs_extlen_t count,const struct xfs_buf_ops * ops)895 xfs_btree_reada_bufl(
896 struct xfs_mount *mp, /* file system mount point */
897 xfs_fsblock_t fsbno, /* file system block number */
898 xfs_extlen_t count, /* count of filesystem blocks */
899 const struct xfs_buf_ops *ops)
900 {
901 xfs_daddr_t d;
902
903 ASSERT(fsbno != NULLFSBLOCK);
904 d = XFS_FSB_TO_DADDR(mp, fsbno);
905 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, ops);
906 }
907
908 /*
909 * Read-ahead the block, don't wait for it, don't return a buffer.
910 * Short-form addressing.
911 */
912 /* ARGSUSED */
913 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)914 xfs_btree_reada_bufs(
915 struct xfs_mount *mp, /* file system mount point */
916 xfs_agnumber_t agno, /* allocation group number */
917 xfs_agblock_t agbno, /* allocation group block number */
918 xfs_extlen_t count, /* count of filesystem blocks */
919 const struct xfs_buf_ops *ops)
920 {
921 xfs_daddr_t d;
922
923 ASSERT(agno != NULLAGNUMBER);
924 ASSERT(agbno != NULLAGBLOCK);
925 d = XFS_AGB_TO_DADDR(mp, agno, agbno);
926 xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, ops);
927 }
928
929 STATIC int
xfs_btree_readahead_lblock(struct xfs_btree_cur * cur,int lr,struct xfs_btree_block * block)930 xfs_btree_readahead_lblock(
931 struct xfs_btree_cur *cur,
932 int lr,
933 struct xfs_btree_block *block)
934 {
935 int rval = 0;
936 xfs_fsblock_t left = be64_to_cpu(block->bb_u.l.bb_leftsib);
937 xfs_fsblock_t right = be64_to_cpu(block->bb_u.l.bb_rightsib);
938
939 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLFSBLOCK) {
940 xfs_btree_reada_bufl(cur->bc_mp, left, 1,
941 cur->bc_ops->buf_ops);
942 rval++;
943 }
944
945 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLFSBLOCK) {
946 xfs_btree_reada_bufl(cur->bc_mp, right, 1,
947 cur->bc_ops->buf_ops);
948 rval++;
949 }
950
951 return rval;
952 }
953
954 STATIC int
xfs_btree_readahead_sblock(struct xfs_btree_cur * cur,int lr,struct xfs_btree_block * block)955 xfs_btree_readahead_sblock(
956 struct xfs_btree_cur *cur,
957 int lr,
958 struct xfs_btree_block *block)
959 {
960 int rval = 0;
961 xfs_agblock_t left = be32_to_cpu(block->bb_u.s.bb_leftsib);
962 xfs_agblock_t right = be32_to_cpu(block->bb_u.s.bb_rightsib);
963
964
965 if ((lr & XFS_BTCUR_LEFTRA) && left != NULLAGBLOCK) {
966 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_ag.pag->pag_agno,
967 left, 1, cur->bc_ops->buf_ops);
968 rval++;
969 }
970
971 if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLAGBLOCK) {
972 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_ag.pag->pag_agno,
973 right, 1, cur->bc_ops->buf_ops);
974 rval++;
975 }
976
977 return rval;
978 }
979
980 /*
981 * Read-ahead btree blocks, at the given level.
982 * Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA.
983 */
984 STATIC int
xfs_btree_readahead(struct xfs_btree_cur * cur,int lev,int lr)985 xfs_btree_readahead(
986 struct xfs_btree_cur *cur, /* btree cursor */
987 int lev, /* level in btree */
988 int lr) /* left/right bits */
989 {
990 struct xfs_btree_block *block;
991
992 /*
993 * No readahead needed if we are at the root level and the
994 * btree root is stored in the inode.
995 */
996 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
997 (lev == cur->bc_nlevels - 1))
998 return 0;
999
1000 if ((cur->bc_levels[lev].ra | lr) == cur->bc_levels[lev].ra)
1001 return 0;
1002
1003 cur->bc_levels[lev].ra |= lr;
1004 block = XFS_BUF_TO_BLOCK(cur->bc_levels[lev].bp);
1005
1006 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1007 return xfs_btree_readahead_lblock(cur, lr, block);
1008 return xfs_btree_readahead_sblock(cur, lr, block);
1009 }
1010
1011 STATIC int
xfs_btree_ptr_to_daddr(struct xfs_btree_cur * cur,const union xfs_btree_ptr * ptr,xfs_daddr_t * daddr)1012 xfs_btree_ptr_to_daddr(
1013 struct xfs_btree_cur *cur,
1014 const union xfs_btree_ptr *ptr,
1015 xfs_daddr_t *daddr)
1016 {
1017 xfs_fsblock_t fsbno;
1018 xfs_agblock_t agbno;
1019 int error;
1020
1021 error = xfs_btree_check_ptr(cur, ptr, 0, 1);
1022 if (error)
1023 return error;
1024
1025 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1026 fsbno = be64_to_cpu(ptr->l);
1027 *daddr = XFS_FSB_TO_DADDR(cur->bc_mp, fsbno);
1028 } else {
1029 agbno = be32_to_cpu(ptr->s);
1030 *daddr = XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_ag.pag->pag_agno,
1031 agbno);
1032 }
1033
1034 return 0;
1035 }
1036
1037 /*
1038 * Readahead @count btree blocks at the given @ptr location.
1039 *
1040 * We don't need to care about long or short form btrees here as we have a
1041 * method of converting the ptr directly to a daddr available to us.
1042 */
1043 STATIC void
xfs_btree_readahead_ptr(struct xfs_btree_cur * cur,union xfs_btree_ptr * ptr,xfs_extlen_t count)1044 xfs_btree_readahead_ptr(
1045 struct xfs_btree_cur *cur,
1046 union xfs_btree_ptr *ptr,
1047 xfs_extlen_t count)
1048 {
1049 xfs_daddr_t daddr;
1050
1051 if (xfs_btree_ptr_to_daddr(cur, ptr, &daddr))
1052 return;
1053 xfs_buf_readahead(cur->bc_mp->m_ddev_targp, daddr,
1054 cur->bc_mp->m_bsize * count, cur->bc_ops->buf_ops);
1055 }
1056
1057 /*
1058 * Set the buffer for level "lev" in the cursor to bp, releasing
1059 * any previous buffer.
1060 */
1061 STATIC void
xfs_btree_setbuf(struct xfs_btree_cur * cur,int lev,struct xfs_buf * bp)1062 xfs_btree_setbuf(
1063 struct xfs_btree_cur *cur, /* btree cursor */
1064 int lev, /* level in btree */
1065 struct xfs_buf *bp) /* new buffer to set */
1066 {
1067 struct xfs_btree_block *b; /* btree block */
1068
1069 if (cur->bc_levels[lev].bp)
1070 xfs_trans_brelse(cur->bc_tp, cur->bc_levels[lev].bp);
1071 cur->bc_levels[lev].bp = bp;
1072 cur->bc_levels[lev].ra = 0;
1073
1074 b = XFS_BUF_TO_BLOCK(bp);
1075 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1076 if (b->bb_u.l.bb_leftsib == cpu_to_be64(NULLFSBLOCK))
1077 cur->bc_levels[lev].ra |= XFS_BTCUR_LEFTRA;
1078 if (b->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK))
1079 cur->bc_levels[lev].ra |= XFS_BTCUR_RIGHTRA;
1080 } else {
1081 if (b->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK))
1082 cur->bc_levels[lev].ra |= XFS_BTCUR_LEFTRA;
1083 if (b->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK))
1084 cur->bc_levels[lev].ra |= XFS_BTCUR_RIGHTRA;
1085 }
1086 }
1087
1088 bool
xfs_btree_ptr_is_null(struct xfs_btree_cur * cur,const union xfs_btree_ptr * ptr)1089 xfs_btree_ptr_is_null(
1090 struct xfs_btree_cur *cur,
1091 const union xfs_btree_ptr *ptr)
1092 {
1093 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1094 return ptr->l == cpu_to_be64(NULLFSBLOCK);
1095 else
1096 return ptr->s == cpu_to_be32(NULLAGBLOCK);
1097 }
1098
1099 void
xfs_btree_set_ptr_null(struct xfs_btree_cur * cur,union xfs_btree_ptr * ptr)1100 xfs_btree_set_ptr_null(
1101 struct xfs_btree_cur *cur,
1102 union xfs_btree_ptr *ptr)
1103 {
1104 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1105 ptr->l = cpu_to_be64(NULLFSBLOCK);
1106 else
1107 ptr->s = cpu_to_be32(NULLAGBLOCK);
1108 }
1109
1110 /*
1111 * Get/set/init sibling pointers
1112 */
1113 void
xfs_btree_get_sibling(struct xfs_btree_cur * cur,struct xfs_btree_block * block,union xfs_btree_ptr * ptr,int lr)1114 xfs_btree_get_sibling(
1115 struct xfs_btree_cur *cur,
1116 struct xfs_btree_block *block,
1117 union xfs_btree_ptr *ptr,
1118 int lr)
1119 {
1120 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
1121
1122 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1123 if (lr == XFS_BB_RIGHTSIB)
1124 ptr->l = block->bb_u.l.bb_rightsib;
1125 else
1126 ptr->l = block->bb_u.l.bb_leftsib;
1127 } else {
1128 if (lr == XFS_BB_RIGHTSIB)
1129 ptr->s = block->bb_u.s.bb_rightsib;
1130 else
1131 ptr->s = block->bb_u.s.bb_leftsib;
1132 }
1133 }
1134
1135 void
xfs_btree_set_sibling(struct xfs_btree_cur * cur,struct xfs_btree_block * block,const union xfs_btree_ptr * ptr,int lr)1136 xfs_btree_set_sibling(
1137 struct xfs_btree_cur *cur,
1138 struct xfs_btree_block *block,
1139 const union xfs_btree_ptr *ptr,
1140 int lr)
1141 {
1142 ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
1143
1144 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1145 if (lr == XFS_BB_RIGHTSIB)
1146 block->bb_u.l.bb_rightsib = ptr->l;
1147 else
1148 block->bb_u.l.bb_leftsib = ptr->l;
1149 } else {
1150 if (lr == XFS_BB_RIGHTSIB)
1151 block->bb_u.s.bb_rightsib = ptr->s;
1152 else
1153 block->bb_u.s.bb_leftsib = ptr->s;
1154 }
1155 }
1156
1157 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)1158 xfs_btree_init_block_int(
1159 struct xfs_mount *mp,
1160 struct xfs_btree_block *buf,
1161 xfs_daddr_t blkno,
1162 xfs_btnum_t btnum,
1163 __u16 level,
1164 __u16 numrecs,
1165 __u64 owner,
1166 unsigned int flags)
1167 {
1168 int crc = xfs_has_crc(mp);
1169 __u32 magic = xfs_btree_magic(crc, btnum);
1170
1171 buf->bb_magic = cpu_to_be32(magic);
1172 buf->bb_level = cpu_to_be16(level);
1173 buf->bb_numrecs = cpu_to_be16(numrecs);
1174
1175 if (flags & XFS_BTREE_LONG_PTRS) {
1176 buf->bb_u.l.bb_leftsib = cpu_to_be64(NULLFSBLOCK);
1177 buf->bb_u.l.bb_rightsib = cpu_to_be64(NULLFSBLOCK);
1178 if (crc) {
1179 buf->bb_u.l.bb_blkno = cpu_to_be64(blkno);
1180 buf->bb_u.l.bb_owner = cpu_to_be64(owner);
1181 uuid_copy(&buf->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid);
1182 buf->bb_u.l.bb_pad = 0;
1183 buf->bb_u.l.bb_lsn = 0;
1184 }
1185 } else {
1186 /* owner is a 32 bit value on short blocks */
1187 __u32 __owner = (__u32)owner;
1188
1189 buf->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
1190 buf->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
1191 if (crc) {
1192 buf->bb_u.s.bb_blkno = cpu_to_be64(blkno);
1193 buf->bb_u.s.bb_owner = cpu_to_be32(__owner);
1194 uuid_copy(&buf->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid);
1195 buf->bb_u.s.bb_lsn = 0;
1196 }
1197 }
1198 }
1199
1200 void
xfs_btree_init_block(struct xfs_mount * mp,struct xfs_buf * bp,xfs_btnum_t btnum,__u16 level,__u16 numrecs,__u64 owner)1201 xfs_btree_init_block(
1202 struct xfs_mount *mp,
1203 struct xfs_buf *bp,
1204 xfs_btnum_t btnum,
1205 __u16 level,
1206 __u16 numrecs,
1207 __u64 owner)
1208 {
1209 xfs_btree_init_block_int(mp, XFS_BUF_TO_BLOCK(bp), xfs_buf_daddr(bp),
1210 btnum, level, numrecs, owner, 0);
1211 }
1212
1213 void
xfs_btree_init_block_cur(struct xfs_btree_cur * cur,struct xfs_buf * bp,int level,int numrecs)1214 xfs_btree_init_block_cur(
1215 struct xfs_btree_cur *cur,
1216 struct xfs_buf *bp,
1217 int level,
1218 int numrecs)
1219 {
1220 __u64 owner;
1221
1222 /*
1223 * we can pull the owner from the cursor right now as the different
1224 * owners align directly with the pointer size of the btree. This may
1225 * change in future, but is safe for current users of the generic btree
1226 * code.
1227 */
1228 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1229 owner = cur->bc_ino.ip->i_ino;
1230 else
1231 owner = cur->bc_ag.pag->pag_agno;
1232
1233 xfs_btree_init_block_int(cur->bc_mp, XFS_BUF_TO_BLOCK(bp),
1234 xfs_buf_daddr(bp), cur->bc_btnum, level,
1235 numrecs, owner, cur->bc_flags);
1236 }
1237
1238 /*
1239 * Return true if ptr is the last record in the btree and
1240 * we need to track updates to this record. The decision
1241 * will be further refined in the update_lastrec method.
1242 */
1243 STATIC int
xfs_btree_is_lastrec(struct xfs_btree_cur * cur,struct xfs_btree_block * block,int level)1244 xfs_btree_is_lastrec(
1245 struct xfs_btree_cur *cur,
1246 struct xfs_btree_block *block,
1247 int level)
1248 {
1249 union xfs_btree_ptr ptr;
1250
1251 if (level > 0)
1252 return 0;
1253 if (!(cur->bc_flags & XFS_BTREE_LASTREC_UPDATE))
1254 return 0;
1255
1256 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1257 if (!xfs_btree_ptr_is_null(cur, &ptr))
1258 return 0;
1259 return 1;
1260 }
1261
1262 STATIC void
xfs_btree_buf_to_ptr(struct xfs_btree_cur * cur,struct xfs_buf * bp,union xfs_btree_ptr * ptr)1263 xfs_btree_buf_to_ptr(
1264 struct xfs_btree_cur *cur,
1265 struct xfs_buf *bp,
1266 union xfs_btree_ptr *ptr)
1267 {
1268 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1269 ptr->l = cpu_to_be64(XFS_DADDR_TO_FSB(cur->bc_mp,
1270 xfs_buf_daddr(bp)));
1271 else {
1272 ptr->s = cpu_to_be32(xfs_daddr_to_agbno(cur->bc_mp,
1273 xfs_buf_daddr(bp)));
1274 }
1275 }
1276
1277 STATIC void
xfs_btree_set_refs(struct xfs_btree_cur * cur,struct xfs_buf * bp)1278 xfs_btree_set_refs(
1279 struct xfs_btree_cur *cur,
1280 struct xfs_buf *bp)
1281 {
1282 switch (cur->bc_btnum) {
1283 case XFS_BTNUM_BNO:
1284 case XFS_BTNUM_CNT:
1285 xfs_buf_set_ref(bp, XFS_ALLOC_BTREE_REF);
1286 break;
1287 case XFS_BTNUM_INO:
1288 case XFS_BTNUM_FINO:
1289 xfs_buf_set_ref(bp, XFS_INO_BTREE_REF);
1290 break;
1291 case XFS_BTNUM_BMAP:
1292 xfs_buf_set_ref(bp, XFS_BMAP_BTREE_REF);
1293 break;
1294 case XFS_BTNUM_RMAP:
1295 xfs_buf_set_ref(bp, XFS_RMAP_BTREE_REF);
1296 break;
1297 case XFS_BTNUM_REFC:
1298 xfs_buf_set_ref(bp, XFS_REFC_BTREE_REF);
1299 break;
1300 default:
1301 ASSERT(0);
1302 }
1303 }
1304
1305 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)1306 xfs_btree_get_buf_block(
1307 struct xfs_btree_cur *cur,
1308 const union xfs_btree_ptr *ptr,
1309 struct xfs_btree_block **block,
1310 struct xfs_buf **bpp)
1311 {
1312 struct xfs_mount *mp = cur->bc_mp;
1313 xfs_daddr_t d;
1314 int error;
1315
1316 error = xfs_btree_ptr_to_daddr(cur, ptr, &d);
1317 if (error)
1318 return error;
1319 error = xfs_trans_get_buf(cur->bc_tp, mp->m_ddev_targp, d, mp->m_bsize,
1320 0, bpp);
1321 if (error)
1322 return error;
1323
1324 (*bpp)->b_ops = cur->bc_ops->buf_ops;
1325 *block = XFS_BUF_TO_BLOCK(*bpp);
1326 return 0;
1327 }
1328
1329 /*
1330 * Read in the buffer at the given ptr and return the buffer and
1331 * the block pointer within the buffer.
1332 */
1333 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)1334 xfs_btree_read_buf_block(
1335 struct xfs_btree_cur *cur,
1336 const union xfs_btree_ptr *ptr,
1337 int flags,
1338 struct xfs_btree_block **block,
1339 struct xfs_buf **bpp)
1340 {
1341 struct xfs_mount *mp = cur->bc_mp;
1342 xfs_daddr_t d;
1343 int error;
1344
1345 /* need to sort out how callers deal with failures first */
1346 ASSERT(!(flags & XBF_TRYLOCK));
1347
1348 error = xfs_btree_ptr_to_daddr(cur, ptr, &d);
1349 if (error)
1350 return error;
1351 error = xfs_trans_read_buf(mp, cur->bc_tp, mp->m_ddev_targp, d,
1352 mp->m_bsize, flags, bpp,
1353 cur->bc_ops->buf_ops);
1354 if (error)
1355 return error;
1356
1357 xfs_btree_set_refs(cur, *bpp);
1358 *block = XFS_BUF_TO_BLOCK(*bpp);
1359 return 0;
1360 }
1361
1362 /*
1363 * Copy keys from one btree block to another.
1364 */
1365 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)1366 xfs_btree_copy_keys(
1367 struct xfs_btree_cur *cur,
1368 union xfs_btree_key *dst_key,
1369 const union xfs_btree_key *src_key,
1370 int numkeys)
1371 {
1372 ASSERT(numkeys >= 0);
1373 memcpy(dst_key, src_key, numkeys * cur->bc_ops->key_len);
1374 }
1375
1376 /*
1377 * Copy records from one btree block to another.
1378 */
1379 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)1380 xfs_btree_copy_recs(
1381 struct xfs_btree_cur *cur,
1382 union xfs_btree_rec *dst_rec,
1383 union xfs_btree_rec *src_rec,
1384 int numrecs)
1385 {
1386 ASSERT(numrecs >= 0);
1387 memcpy(dst_rec, src_rec, numrecs * cur->bc_ops->rec_len);
1388 }
1389
1390 /*
1391 * Copy block pointers from one btree block to another.
1392 */
1393 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)1394 xfs_btree_copy_ptrs(
1395 struct xfs_btree_cur *cur,
1396 union xfs_btree_ptr *dst_ptr,
1397 const union xfs_btree_ptr *src_ptr,
1398 int numptrs)
1399 {
1400 ASSERT(numptrs >= 0);
1401 memcpy(dst_ptr, src_ptr, numptrs * xfs_btree_ptr_len(cur));
1402 }
1403
1404 /*
1405 * Shift keys one index left/right inside a single btree block.
1406 */
1407 STATIC void
xfs_btree_shift_keys(struct xfs_btree_cur * cur,union xfs_btree_key * key,int dir,int numkeys)1408 xfs_btree_shift_keys(
1409 struct xfs_btree_cur *cur,
1410 union xfs_btree_key *key,
1411 int dir,
1412 int numkeys)
1413 {
1414 char *dst_key;
1415
1416 ASSERT(numkeys >= 0);
1417 ASSERT(dir == 1 || dir == -1);
1418
1419 dst_key = (char *)key + (dir * cur->bc_ops->key_len);
1420 memmove(dst_key, key, numkeys * cur->bc_ops->key_len);
1421 }
1422
1423 /*
1424 * Shift records one index left/right inside a single btree block.
1425 */
1426 STATIC void
xfs_btree_shift_recs(struct xfs_btree_cur * cur,union xfs_btree_rec * rec,int dir,int numrecs)1427 xfs_btree_shift_recs(
1428 struct xfs_btree_cur *cur,
1429 union xfs_btree_rec *rec,
1430 int dir,
1431 int numrecs)
1432 {
1433 char *dst_rec;
1434
1435 ASSERT(numrecs >= 0);
1436 ASSERT(dir == 1 || dir == -1);
1437
1438 dst_rec = (char *)rec + (dir * cur->bc_ops->rec_len);
1439 memmove(dst_rec, rec, numrecs * cur->bc_ops->rec_len);
1440 }
1441
1442 /*
1443 * Shift block pointers one index left/right inside a single btree block.
1444 */
1445 STATIC void
xfs_btree_shift_ptrs(struct xfs_btree_cur * cur,union xfs_btree_ptr * ptr,int dir,int numptrs)1446 xfs_btree_shift_ptrs(
1447 struct xfs_btree_cur *cur,
1448 union xfs_btree_ptr *ptr,
1449 int dir,
1450 int numptrs)
1451 {
1452 char *dst_ptr;
1453
1454 ASSERT(numptrs >= 0);
1455 ASSERT(dir == 1 || dir == -1);
1456
1457 dst_ptr = (char *)ptr + (dir * xfs_btree_ptr_len(cur));
1458 memmove(dst_ptr, ptr, numptrs * xfs_btree_ptr_len(cur));
1459 }
1460
1461 /*
1462 * Log key values from the btree block.
1463 */
1464 STATIC void
xfs_btree_log_keys(struct xfs_btree_cur * cur,struct xfs_buf * bp,int first,int last)1465 xfs_btree_log_keys(
1466 struct xfs_btree_cur *cur,
1467 struct xfs_buf *bp,
1468 int first,
1469 int last)
1470 {
1471
1472 if (bp) {
1473 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1474 xfs_trans_log_buf(cur->bc_tp, bp,
1475 xfs_btree_key_offset(cur, first),
1476 xfs_btree_key_offset(cur, last + 1) - 1);
1477 } else {
1478 xfs_trans_log_inode(cur->bc_tp, cur->bc_ino.ip,
1479 xfs_ilog_fbroot(cur->bc_ino.whichfork));
1480 }
1481 }
1482
1483 /*
1484 * Log record values from the btree block.
1485 */
1486 void
xfs_btree_log_recs(struct xfs_btree_cur * cur,struct xfs_buf * bp,int first,int last)1487 xfs_btree_log_recs(
1488 struct xfs_btree_cur *cur,
1489 struct xfs_buf *bp,
1490 int first,
1491 int last)
1492 {
1493
1494 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1495 xfs_trans_log_buf(cur->bc_tp, bp,
1496 xfs_btree_rec_offset(cur, first),
1497 xfs_btree_rec_offset(cur, last + 1) - 1);
1498
1499 }
1500
1501 /*
1502 * Log block pointer fields from a btree block (nonleaf).
1503 */
1504 STATIC void
xfs_btree_log_ptrs(struct xfs_btree_cur * cur,struct xfs_buf * bp,int first,int last)1505 xfs_btree_log_ptrs(
1506 struct xfs_btree_cur *cur, /* btree cursor */
1507 struct xfs_buf *bp, /* buffer containing btree block */
1508 int first, /* index of first pointer to log */
1509 int last) /* index of last pointer to log */
1510 {
1511
1512 if (bp) {
1513 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
1514 int level = xfs_btree_get_level(block);
1515
1516 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1517 xfs_trans_log_buf(cur->bc_tp, bp,
1518 xfs_btree_ptr_offset(cur, first, level),
1519 xfs_btree_ptr_offset(cur, last + 1, level) - 1);
1520 } else {
1521 xfs_trans_log_inode(cur->bc_tp, cur->bc_ino.ip,
1522 xfs_ilog_fbroot(cur->bc_ino.whichfork));
1523 }
1524
1525 }
1526
1527 /*
1528 * Log fields from a btree block header.
1529 */
1530 void
xfs_btree_log_block(struct xfs_btree_cur * cur,struct xfs_buf * bp,uint32_t fields)1531 xfs_btree_log_block(
1532 struct xfs_btree_cur *cur, /* btree cursor */
1533 struct xfs_buf *bp, /* buffer containing btree block */
1534 uint32_t fields) /* mask of fields: XFS_BB_... */
1535 {
1536 int first; /* first byte offset logged */
1537 int last; /* last byte offset logged */
1538 static const short soffsets[] = { /* table of offsets (short) */
1539 offsetof(struct xfs_btree_block, bb_magic),
1540 offsetof(struct xfs_btree_block, bb_level),
1541 offsetof(struct xfs_btree_block, bb_numrecs),
1542 offsetof(struct xfs_btree_block, bb_u.s.bb_leftsib),
1543 offsetof(struct xfs_btree_block, bb_u.s.bb_rightsib),
1544 offsetof(struct xfs_btree_block, bb_u.s.bb_blkno),
1545 offsetof(struct xfs_btree_block, bb_u.s.bb_lsn),
1546 offsetof(struct xfs_btree_block, bb_u.s.bb_uuid),
1547 offsetof(struct xfs_btree_block, bb_u.s.bb_owner),
1548 offsetof(struct xfs_btree_block, bb_u.s.bb_crc),
1549 XFS_BTREE_SBLOCK_CRC_LEN
1550 };
1551 static const short loffsets[] = { /* table of offsets (long) */
1552 offsetof(struct xfs_btree_block, bb_magic),
1553 offsetof(struct xfs_btree_block, bb_level),
1554 offsetof(struct xfs_btree_block, bb_numrecs),
1555 offsetof(struct xfs_btree_block, bb_u.l.bb_leftsib),
1556 offsetof(struct xfs_btree_block, bb_u.l.bb_rightsib),
1557 offsetof(struct xfs_btree_block, bb_u.l.bb_blkno),
1558 offsetof(struct xfs_btree_block, bb_u.l.bb_lsn),
1559 offsetof(struct xfs_btree_block, bb_u.l.bb_uuid),
1560 offsetof(struct xfs_btree_block, bb_u.l.bb_owner),
1561 offsetof(struct xfs_btree_block, bb_u.l.bb_crc),
1562 offsetof(struct xfs_btree_block, bb_u.l.bb_pad),
1563 XFS_BTREE_LBLOCK_CRC_LEN
1564 };
1565
1566 if (bp) {
1567 int nbits;
1568
1569 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) {
1570 /*
1571 * We don't log the CRC when updating a btree
1572 * block but instead recreate it during log
1573 * recovery. As the log buffers have checksums
1574 * of their own this is safe and avoids logging a crc
1575 * update in a lot of places.
1576 */
1577 if (fields == XFS_BB_ALL_BITS)
1578 fields = XFS_BB_ALL_BITS_CRC;
1579 nbits = XFS_BB_NUM_BITS_CRC;
1580 } else {
1581 nbits = XFS_BB_NUM_BITS;
1582 }
1583 xfs_btree_offsets(fields,
1584 (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
1585 loffsets : soffsets,
1586 nbits, &first, &last);
1587 xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1588 xfs_trans_log_buf(cur->bc_tp, bp, first, last);
1589 } else {
1590 xfs_trans_log_inode(cur->bc_tp, cur->bc_ino.ip,
1591 xfs_ilog_fbroot(cur->bc_ino.whichfork));
1592 }
1593 }
1594
1595 /*
1596 * Increment cursor by one record at the level.
1597 * For nonzero levels the leaf-ward information is untouched.
1598 */
1599 int /* error */
xfs_btree_increment(struct xfs_btree_cur * cur,int level,int * stat)1600 xfs_btree_increment(
1601 struct xfs_btree_cur *cur,
1602 int level,
1603 int *stat) /* success/failure */
1604 {
1605 struct xfs_btree_block *block;
1606 union xfs_btree_ptr ptr;
1607 struct xfs_buf *bp;
1608 int error; /* error return value */
1609 int lev;
1610
1611 ASSERT(level < cur->bc_nlevels);
1612
1613 /* Read-ahead to the right at this level. */
1614 xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
1615
1616 /* Get a pointer to the btree block. */
1617 block = xfs_btree_get_block(cur, level, &bp);
1618
1619 #ifdef DEBUG
1620 error = xfs_btree_check_block(cur, block, level, bp);
1621 if (error)
1622 goto error0;
1623 #endif
1624
1625 /* We're done if we remain in the block after the increment. */
1626 if (++cur->bc_levels[level].ptr <= xfs_btree_get_numrecs(block))
1627 goto out1;
1628
1629 /* Fail if we just went off the right edge of the tree. */
1630 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1631 if (xfs_btree_ptr_is_null(cur, &ptr))
1632 goto out0;
1633
1634 XFS_BTREE_STATS_INC(cur, increment);
1635
1636 /*
1637 * March up the tree incrementing pointers.
1638 * Stop when we don't go off the right edge of a block.
1639 */
1640 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1641 block = xfs_btree_get_block(cur, lev, &bp);
1642
1643 #ifdef DEBUG
1644 error = xfs_btree_check_block(cur, block, lev, bp);
1645 if (error)
1646 goto error0;
1647 #endif
1648
1649 if (++cur->bc_levels[lev].ptr <= xfs_btree_get_numrecs(block))
1650 break;
1651
1652 /* Read-ahead the right block for the next loop. */
1653 xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA);
1654 }
1655
1656 /*
1657 * If we went off the root then we are either seriously
1658 * confused or have the tree root in an inode.
1659 */
1660 if (lev == cur->bc_nlevels) {
1661 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1662 goto out0;
1663 ASSERT(0);
1664 error = -EFSCORRUPTED;
1665 goto error0;
1666 }
1667 ASSERT(lev < cur->bc_nlevels);
1668
1669 /*
1670 * Now walk back down the tree, fixing up the cursor's buffer
1671 * pointers and key numbers.
1672 */
1673 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1674 union xfs_btree_ptr *ptrp;
1675
1676 ptrp = xfs_btree_ptr_addr(cur, cur->bc_levels[lev].ptr, block);
1677 --lev;
1678 error = xfs_btree_read_buf_block(cur, ptrp, 0, &block, &bp);
1679 if (error)
1680 goto error0;
1681
1682 xfs_btree_setbuf(cur, lev, bp);
1683 cur->bc_levels[lev].ptr = 1;
1684 }
1685 out1:
1686 *stat = 1;
1687 return 0;
1688
1689 out0:
1690 *stat = 0;
1691 return 0;
1692
1693 error0:
1694 return error;
1695 }
1696
1697 /*
1698 * Decrement cursor by one record at the level.
1699 * For nonzero levels the leaf-ward information is untouched.
1700 */
1701 int /* error */
xfs_btree_decrement(struct xfs_btree_cur * cur,int level,int * stat)1702 xfs_btree_decrement(
1703 struct xfs_btree_cur *cur,
1704 int level,
1705 int *stat) /* success/failure */
1706 {
1707 struct xfs_btree_block *block;
1708 struct xfs_buf *bp;
1709 int error; /* error return value */
1710 int lev;
1711 union xfs_btree_ptr ptr;
1712
1713 ASSERT(level < cur->bc_nlevels);
1714
1715 /* Read-ahead to the left at this level. */
1716 xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA);
1717
1718 /* We're done if we remain in the block after the decrement. */
1719 if (--cur->bc_levels[level].ptr > 0)
1720 goto out1;
1721
1722 /* Get a pointer to the btree block. */
1723 block = xfs_btree_get_block(cur, level, &bp);
1724
1725 #ifdef DEBUG
1726 error = xfs_btree_check_block(cur, block, level, bp);
1727 if (error)
1728 goto error0;
1729 #endif
1730
1731 /* Fail if we just went off the left edge of the tree. */
1732 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
1733 if (xfs_btree_ptr_is_null(cur, &ptr))
1734 goto out0;
1735
1736 XFS_BTREE_STATS_INC(cur, decrement);
1737
1738 /*
1739 * March up the tree decrementing pointers.
1740 * Stop when we don't go off the left edge of a block.
1741 */
1742 for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1743 if (--cur->bc_levels[lev].ptr > 0)
1744 break;
1745 /* Read-ahead the left block for the next loop. */
1746 xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA);
1747 }
1748
1749 /*
1750 * If we went off the root then we are seriously confused.
1751 * or the root of the tree is in an inode.
1752 */
1753 if (lev == cur->bc_nlevels) {
1754 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1755 goto out0;
1756 ASSERT(0);
1757 error = -EFSCORRUPTED;
1758 goto error0;
1759 }
1760 ASSERT(lev < cur->bc_nlevels);
1761
1762 /*
1763 * Now walk back down the tree, fixing up the cursor's buffer
1764 * pointers and key numbers.
1765 */
1766 for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1767 union xfs_btree_ptr *ptrp;
1768
1769 ptrp = xfs_btree_ptr_addr(cur, cur->bc_levels[lev].ptr, block);
1770 --lev;
1771 error = xfs_btree_read_buf_block(cur, ptrp, 0, &block, &bp);
1772 if (error)
1773 goto error0;
1774 xfs_btree_setbuf(cur, lev, bp);
1775 cur->bc_levels[lev].ptr = xfs_btree_get_numrecs(block);
1776 }
1777 out1:
1778 *stat = 1;
1779 return 0;
1780
1781 out0:
1782 *stat = 0;
1783 return 0;
1784
1785 error0:
1786 return error;
1787 }
1788
1789 int
xfs_btree_lookup_get_block(struct xfs_btree_cur * cur,int level,const union xfs_btree_ptr * pp,struct xfs_btree_block ** blkp)1790 xfs_btree_lookup_get_block(
1791 struct xfs_btree_cur *cur, /* btree cursor */
1792 int level, /* level in the btree */
1793 const union xfs_btree_ptr *pp, /* ptr to btree block */
1794 struct xfs_btree_block **blkp) /* return btree block */
1795 {
1796 struct xfs_buf *bp; /* buffer pointer for btree block */
1797 xfs_daddr_t daddr;
1798 int error = 0;
1799
1800 /* special case the root block if in an inode */
1801 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1802 (level == cur->bc_nlevels - 1)) {
1803 *blkp = xfs_btree_get_iroot(cur);
1804 return 0;
1805 }
1806
1807 /*
1808 * If the old buffer at this level for the disk address we are
1809 * looking for re-use it.
1810 *
1811 * Otherwise throw it away and get a new one.
1812 */
1813 bp = cur->bc_levels[level].bp;
1814 error = xfs_btree_ptr_to_daddr(cur, pp, &daddr);
1815 if (error)
1816 return error;
1817 if (bp && xfs_buf_daddr(bp) == daddr) {
1818 *blkp = XFS_BUF_TO_BLOCK(bp);
1819 return 0;
1820 }
1821
1822 error = xfs_btree_read_buf_block(cur, pp, 0, blkp, &bp);
1823 if (error)
1824 return error;
1825
1826 /* Check the inode owner since the verifiers don't. */
1827 if (xfs_has_crc(cur->bc_mp) &&
1828 !(cur->bc_ino.flags & XFS_BTCUR_BMBT_INVALID_OWNER) &&
1829 (cur->bc_flags & XFS_BTREE_LONG_PTRS) &&
1830 be64_to_cpu((*blkp)->bb_u.l.bb_owner) !=
1831 cur->bc_ino.ip->i_ino)
1832 goto out_bad;
1833
1834 /* Did we get the level we were looking for? */
1835 if (be16_to_cpu((*blkp)->bb_level) != level)
1836 goto out_bad;
1837
1838 /* Check that internal nodes have at least one record. */
1839 if (level != 0 && be16_to_cpu((*blkp)->bb_numrecs) == 0)
1840 goto out_bad;
1841
1842 xfs_btree_setbuf(cur, level, bp);
1843 return 0;
1844
1845 out_bad:
1846 *blkp = NULL;
1847 xfs_buf_mark_corrupt(bp);
1848 xfs_trans_brelse(cur->bc_tp, bp);
1849 return -EFSCORRUPTED;
1850 }
1851
1852 /*
1853 * Get current search key. For level 0 we don't actually have a key
1854 * structure so we make one up from the record. For all other levels
1855 * we just return the right key.
1856 */
1857 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)1858 xfs_lookup_get_search_key(
1859 struct xfs_btree_cur *cur,
1860 int level,
1861 int keyno,
1862 struct xfs_btree_block *block,
1863 union xfs_btree_key *kp)
1864 {
1865 if (level == 0) {
1866 cur->bc_ops->init_key_from_rec(kp,
1867 xfs_btree_rec_addr(cur, keyno, block));
1868 return kp;
1869 }
1870
1871 return xfs_btree_key_addr(cur, keyno, block);
1872 }
1873
1874 /*
1875 * Lookup the record. The cursor is made to point to it, based on dir.
1876 * stat is set to 0 if can't find any such record, 1 for success.
1877 */
1878 int /* error */
xfs_btree_lookup(struct xfs_btree_cur * cur,xfs_lookup_t dir,int * stat)1879 xfs_btree_lookup(
1880 struct xfs_btree_cur *cur, /* btree cursor */
1881 xfs_lookup_t dir, /* <=, ==, or >= */
1882 int *stat) /* success/failure */
1883 {
1884 struct xfs_btree_block *block; /* current btree block */
1885 int64_t diff; /* difference for the current key */
1886 int error; /* error return value */
1887 int keyno; /* current key number */
1888 int level; /* level in the btree */
1889 union xfs_btree_ptr *pp; /* ptr to btree block */
1890 union xfs_btree_ptr ptr; /* ptr to btree block */
1891
1892 XFS_BTREE_STATS_INC(cur, lookup);
1893
1894 /* No such thing as a zero-level tree. */
1895 if (XFS_IS_CORRUPT(cur->bc_mp, cur->bc_nlevels == 0))
1896 return -EFSCORRUPTED;
1897
1898 block = NULL;
1899 keyno = 0;
1900
1901 /* initialise start pointer from cursor */
1902 cur->bc_ops->init_ptr_from_cur(cur, &ptr);
1903 pp = &ptr;
1904
1905 /*
1906 * Iterate over each level in the btree, starting at the root.
1907 * For each level above the leaves, find the key we need, based
1908 * on the lookup record, then follow the corresponding block
1909 * pointer down to the next level.
1910 */
1911 for (level = cur->bc_nlevels - 1, diff = 1; level >= 0; level--) {
1912 /* Get the block we need to do the lookup on. */
1913 error = xfs_btree_lookup_get_block(cur, level, pp, &block);
1914 if (error)
1915 goto error0;
1916
1917 if (diff == 0) {
1918 /*
1919 * If we already had a key match at a higher level, we
1920 * know we need to use the first entry in this block.
1921 */
1922 keyno = 1;
1923 } else {
1924 /* Otherwise search this block. Do a binary search. */
1925
1926 int high; /* high entry number */
1927 int low; /* low entry number */
1928
1929 /* Set low and high entry numbers, 1-based. */
1930 low = 1;
1931 high = xfs_btree_get_numrecs(block);
1932 if (!high) {
1933 /* Block is empty, must be an empty leaf. */
1934 if (level != 0 || cur->bc_nlevels != 1) {
1935 XFS_CORRUPTION_ERROR(__func__,
1936 XFS_ERRLEVEL_LOW,
1937 cur->bc_mp, block,
1938 sizeof(*block));
1939 return -EFSCORRUPTED;
1940 }
1941
1942 cur->bc_levels[0].ptr = dir != XFS_LOOKUP_LE;
1943 *stat = 0;
1944 return 0;
1945 }
1946
1947 /* Binary search the block. */
1948 while (low <= high) {
1949 union xfs_btree_key key;
1950 union xfs_btree_key *kp;
1951
1952 XFS_BTREE_STATS_INC(cur, compare);
1953
1954 /* keyno is average of low and high. */
1955 keyno = (low + high) >> 1;
1956
1957 /* Get current search key */
1958 kp = xfs_lookup_get_search_key(cur, level,
1959 keyno, block, &key);
1960
1961 /*
1962 * Compute difference to get next direction:
1963 * - less than, move right
1964 * - greater than, move left
1965 * - equal, we're done
1966 */
1967 diff = cur->bc_ops->key_diff(cur, kp);
1968 if (diff < 0)
1969 low = keyno + 1;
1970 else if (diff > 0)
1971 high = keyno - 1;
1972 else
1973 break;
1974 }
1975 }
1976
1977 /*
1978 * If there are more levels, set up for the next level
1979 * by getting the block number and filling in the cursor.
1980 */
1981 if (level > 0) {
1982 /*
1983 * If we moved left, need the previous key number,
1984 * unless there isn't one.
1985 */
1986 if (diff > 0 && --keyno < 1)
1987 keyno = 1;
1988 pp = xfs_btree_ptr_addr(cur, keyno, block);
1989
1990 error = xfs_btree_debug_check_ptr(cur, pp, 0, level);
1991 if (error)
1992 goto error0;
1993
1994 cur->bc_levels[level].ptr = keyno;
1995 }
1996 }
1997
1998 /* Done with the search. See if we need to adjust the results. */
1999 if (dir != XFS_LOOKUP_LE && diff < 0) {
2000 keyno++;
2001 /*
2002 * If ge search and we went off the end of the block, but it's
2003 * not the last block, we're in the wrong block.
2004 */
2005 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
2006 if (dir == XFS_LOOKUP_GE &&
2007 keyno > xfs_btree_get_numrecs(block) &&
2008 !xfs_btree_ptr_is_null(cur, &ptr)) {
2009 int i;
2010
2011 cur->bc_levels[0].ptr = keyno;
2012 error = xfs_btree_increment(cur, 0, &i);
2013 if (error)
2014 goto error0;
2015 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1))
2016 return -EFSCORRUPTED;
2017 *stat = 1;
2018 return 0;
2019 }
2020 } else if (dir == XFS_LOOKUP_LE && diff > 0)
2021 keyno--;
2022 cur->bc_levels[0].ptr = keyno;
2023
2024 /* Return if we succeeded or not. */
2025 if (keyno == 0 || keyno > xfs_btree_get_numrecs(block))
2026 *stat = 0;
2027 else if (dir != XFS_LOOKUP_EQ || diff == 0)
2028 *stat = 1;
2029 else
2030 *stat = 0;
2031 return 0;
2032
2033 error0:
2034 return error;
2035 }
2036
2037 /* Find the high key storage area from a regular key. */
2038 union xfs_btree_key *
xfs_btree_high_key_from_key(struct xfs_btree_cur * cur,union xfs_btree_key * key)2039 xfs_btree_high_key_from_key(
2040 struct xfs_btree_cur *cur,
2041 union xfs_btree_key *key)
2042 {
2043 ASSERT(cur->bc_flags & XFS_BTREE_OVERLAPPING);
2044 return (union xfs_btree_key *)((char *)key +
2045 (cur->bc_ops->key_len / 2));
2046 }
2047
2048 /* Determine the low (and high if overlapped) keys of a leaf block */
2049 STATIC void
xfs_btree_get_leaf_keys(struct xfs_btree_cur * cur,struct xfs_btree_block * block,union xfs_btree_key * key)2050 xfs_btree_get_leaf_keys(
2051 struct xfs_btree_cur *cur,
2052 struct xfs_btree_block *block,
2053 union xfs_btree_key *key)
2054 {
2055 union xfs_btree_key max_hkey;
2056 union xfs_btree_key hkey;
2057 union xfs_btree_rec *rec;
2058 union xfs_btree_key *high;
2059 int n;
2060
2061 rec = xfs_btree_rec_addr(cur, 1, block);
2062 cur->bc_ops->init_key_from_rec(key, rec);
2063
2064 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2065
2066 cur->bc_ops->init_high_key_from_rec(&max_hkey, rec);
2067 for (n = 2; n <= xfs_btree_get_numrecs(block); n++) {
2068 rec = xfs_btree_rec_addr(cur, n, block);
2069 cur->bc_ops->init_high_key_from_rec(&hkey, rec);
2070 if (cur->bc_ops->diff_two_keys(cur, &hkey, &max_hkey)
2071 > 0)
2072 max_hkey = hkey;
2073 }
2074
2075 high = xfs_btree_high_key_from_key(cur, key);
2076 memcpy(high, &max_hkey, cur->bc_ops->key_len / 2);
2077 }
2078 }
2079
2080 /* Determine the low (and high if overlapped) keys of a node block */
2081 STATIC void
xfs_btree_get_node_keys(struct xfs_btree_cur * cur,struct xfs_btree_block * block,union xfs_btree_key * key)2082 xfs_btree_get_node_keys(
2083 struct xfs_btree_cur *cur,
2084 struct xfs_btree_block *block,
2085 union xfs_btree_key *key)
2086 {
2087 union xfs_btree_key *hkey;
2088 union xfs_btree_key *max_hkey;
2089 union xfs_btree_key *high;
2090 int n;
2091
2092 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2093 memcpy(key, xfs_btree_key_addr(cur, 1, block),
2094 cur->bc_ops->key_len / 2);
2095
2096 max_hkey = xfs_btree_high_key_addr(cur, 1, block);
2097 for (n = 2; n <= xfs_btree_get_numrecs(block); n++) {
2098 hkey = xfs_btree_high_key_addr(cur, n, block);
2099 if (cur->bc_ops->diff_two_keys(cur, hkey, max_hkey) > 0)
2100 max_hkey = hkey;
2101 }
2102
2103 high = xfs_btree_high_key_from_key(cur, key);
2104 memcpy(high, max_hkey, cur->bc_ops->key_len / 2);
2105 } else {
2106 memcpy(key, xfs_btree_key_addr(cur, 1, block),
2107 cur->bc_ops->key_len);
2108 }
2109 }
2110
2111 /* Derive the keys for any btree block. */
2112 void
xfs_btree_get_keys(struct xfs_btree_cur * cur,struct xfs_btree_block * block,union xfs_btree_key * key)2113 xfs_btree_get_keys(
2114 struct xfs_btree_cur *cur,
2115 struct xfs_btree_block *block,
2116 union xfs_btree_key *key)
2117 {
2118 if (be16_to_cpu(block->bb_level) == 0)
2119 xfs_btree_get_leaf_keys(cur, block, key);
2120 else
2121 xfs_btree_get_node_keys(cur, block, key);
2122 }
2123
2124 /*
2125 * Decide if we need to update the parent keys of a btree block. For
2126 * a standard btree this is only necessary if we're updating the first
2127 * record/key. For an overlapping btree, we must always update the
2128 * keys because the highest key can be in any of the records or keys
2129 * in the block.
2130 */
2131 static inline bool
xfs_btree_needs_key_update(struct xfs_btree_cur * cur,int ptr)2132 xfs_btree_needs_key_update(
2133 struct xfs_btree_cur *cur,
2134 int ptr)
2135 {
2136 return (cur->bc_flags & XFS_BTREE_OVERLAPPING) || ptr == 1;
2137 }
2138
2139 /*
2140 * Update the low and high parent keys of the given level, progressing
2141 * towards the root. If force_all is false, stop if the keys for a given
2142 * level do not need updating.
2143 */
2144 STATIC int
__xfs_btree_updkeys(struct xfs_btree_cur * cur,int level,struct xfs_btree_block * block,struct xfs_buf * bp0,bool force_all)2145 __xfs_btree_updkeys(
2146 struct xfs_btree_cur *cur,
2147 int level,
2148 struct xfs_btree_block *block,
2149 struct xfs_buf *bp0,
2150 bool force_all)
2151 {
2152 union xfs_btree_key key; /* keys from current level */
2153 union xfs_btree_key *lkey; /* keys from the next level up */
2154 union xfs_btree_key *hkey;
2155 union xfs_btree_key *nlkey; /* keys from the next level up */
2156 union xfs_btree_key *nhkey;
2157 struct xfs_buf *bp;
2158 int ptr;
2159
2160 ASSERT(cur->bc_flags & XFS_BTREE_OVERLAPPING);
2161
2162 /* Exit if there aren't any parent levels to update. */
2163 if (level + 1 >= cur->bc_nlevels)
2164 return 0;
2165
2166 trace_xfs_btree_updkeys(cur, level, bp0);
2167
2168 lkey = &key;
2169 hkey = xfs_btree_high_key_from_key(cur, lkey);
2170 xfs_btree_get_keys(cur, block, lkey);
2171 for (level++; level < cur->bc_nlevels; level++) {
2172 #ifdef DEBUG
2173 int error;
2174 #endif
2175 block = xfs_btree_get_block(cur, level, &bp);
2176 trace_xfs_btree_updkeys(cur, level, bp);
2177 #ifdef DEBUG
2178 error = xfs_btree_check_block(cur, block, level, bp);
2179 if (error)
2180 return error;
2181 #endif
2182 ptr = cur->bc_levels[level].ptr;
2183 nlkey = xfs_btree_key_addr(cur, ptr, block);
2184 nhkey = xfs_btree_high_key_addr(cur, ptr, block);
2185 if (!force_all &&
2186 !(cur->bc_ops->diff_two_keys(cur, nlkey, lkey) != 0 ||
2187 cur->bc_ops->diff_two_keys(cur, nhkey, hkey) != 0))
2188 break;
2189 xfs_btree_copy_keys(cur, nlkey, lkey, 1);
2190 xfs_btree_log_keys(cur, bp, ptr, ptr);
2191 if (level + 1 >= cur->bc_nlevels)
2192 break;
2193 xfs_btree_get_node_keys(cur, block, lkey);
2194 }
2195
2196 return 0;
2197 }
2198
2199 /* Update all the keys from some level in cursor back to the root. */
2200 STATIC int
xfs_btree_updkeys_force(struct xfs_btree_cur * cur,int level)2201 xfs_btree_updkeys_force(
2202 struct xfs_btree_cur *cur,
2203 int level)
2204 {
2205 struct xfs_buf *bp;
2206 struct xfs_btree_block *block;
2207
2208 block = xfs_btree_get_block(cur, level, &bp);
2209 return __xfs_btree_updkeys(cur, level, block, bp, true);
2210 }
2211
2212 /*
2213 * Update the parent keys of the given level, progressing towards the root.
2214 */
2215 STATIC int
xfs_btree_update_keys(struct xfs_btree_cur * cur,int level)2216 xfs_btree_update_keys(
2217 struct xfs_btree_cur *cur,
2218 int level)
2219 {
2220 struct xfs_btree_block *block;
2221 struct xfs_buf *bp;
2222 union xfs_btree_key *kp;
2223 union xfs_btree_key key;
2224 int ptr;
2225
2226 ASSERT(level >= 0);
2227
2228 block = xfs_btree_get_block(cur, level, &bp);
2229 if (cur->bc_flags & XFS_BTREE_OVERLAPPING)
2230 return __xfs_btree_updkeys(cur, level, block, bp, false);
2231
2232 /*
2233 * Go up the tree from this level toward the root.
2234 * At each level, update the key value to the value input.
2235 * Stop when we reach a level where the cursor isn't pointing
2236 * at the first entry in the block.
2237 */
2238 xfs_btree_get_keys(cur, block, &key);
2239 for (level++, ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) {
2240 #ifdef DEBUG
2241 int error;
2242 #endif
2243 block = xfs_btree_get_block(cur, level, &bp);
2244 #ifdef DEBUG
2245 error = xfs_btree_check_block(cur, block, level, bp);
2246 if (error)
2247 return error;
2248 #endif
2249 ptr = cur->bc_levels[level].ptr;
2250 kp = xfs_btree_key_addr(cur, ptr, block);
2251 xfs_btree_copy_keys(cur, kp, &key, 1);
2252 xfs_btree_log_keys(cur, bp, ptr, ptr);
2253 }
2254
2255 return 0;
2256 }
2257
2258 /*
2259 * Update the record referred to by cur to the value in the
2260 * given record. This either works (return 0) or gets an
2261 * EFSCORRUPTED error.
2262 */
2263 int
xfs_btree_update(struct xfs_btree_cur * cur,union xfs_btree_rec * rec)2264 xfs_btree_update(
2265 struct xfs_btree_cur *cur,
2266 union xfs_btree_rec *rec)
2267 {
2268 struct xfs_btree_block *block;
2269 struct xfs_buf *bp;
2270 int error;
2271 int ptr;
2272 union xfs_btree_rec *rp;
2273
2274 /* Pick up the current block. */
2275 block = xfs_btree_get_block(cur, 0, &bp);
2276
2277 #ifdef DEBUG
2278 error = xfs_btree_check_block(cur, block, 0, bp);
2279 if (error)
2280 goto error0;
2281 #endif
2282 /* Get the address of the rec to be updated. */
2283 ptr = cur->bc_levels[0].ptr;
2284 rp = xfs_btree_rec_addr(cur, ptr, block);
2285
2286 /* Fill in the new contents and log them. */
2287 xfs_btree_copy_recs(cur, rp, rec, 1);
2288 xfs_btree_log_recs(cur, bp, ptr, ptr);
2289
2290 /*
2291 * If we are tracking the last record in the tree and
2292 * we are at the far right edge of the tree, update it.
2293 */
2294 if (xfs_btree_is_lastrec(cur, block, 0)) {
2295 cur->bc_ops->update_lastrec(cur, block, rec,
2296 ptr, LASTREC_UPDATE);
2297 }
2298
2299 /* Pass new key value up to our parent. */
2300 if (xfs_btree_needs_key_update(cur, ptr)) {
2301 error = xfs_btree_update_keys(cur, 0);
2302 if (error)
2303 goto error0;
2304 }
2305
2306 return 0;
2307
2308 error0:
2309 return error;
2310 }
2311
2312 /*
2313 * Move 1 record left from cur/level if possible.
2314 * Update cur to reflect the new path.
2315 */
2316 STATIC int /* error */
xfs_btree_lshift(struct xfs_btree_cur * cur,int level,int * stat)2317 xfs_btree_lshift(
2318 struct xfs_btree_cur *cur,
2319 int level,
2320 int *stat) /* success/failure */
2321 {
2322 struct xfs_buf *lbp; /* left buffer pointer */
2323 struct xfs_btree_block *left; /* left btree block */
2324 int lrecs; /* left record count */
2325 struct xfs_buf *rbp; /* right buffer pointer */
2326 struct xfs_btree_block *right; /* right btree block */
2327 struct xfs_btree_cur *tcur; /* temporary btree cursor */
2328 int rrecs; /* right record count */
2329 union xfs_btree_ptr lptr; /* left btree pointer */
2330 union xfs_btree_key *rkp = NULL; /* right btree key */
2331 union xfs_btree_ptr *rpp = NULL; /* right address pointer */
2332 union xfs_btree_rec *rrp = NULL; /* right record pointer */
2333 int error; /* error return value */
2334 int i;
2335
2336 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2337 level == cur->bc_nlevels - 1)
2338 goto out0;
2339
2340 /* Set up variables for this block as "right". */
2341 right = xfs_btree_get_block(cur, level, &rbp);
2342
2343 #ifdef DEBUG
2344 error = xfs_btree_check_block(cur, right, level, rbp);
2345 if (error)
2346 goto error0;
2347 #endif
2348
2349 /* If we've got no left sibling then we can't shift an entry left. */
2350 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2351 if (xfs_btree_ptr_is_null(cur, &lptr))
2352 goto out0;
2353
2354 /*
2355 * If the cursor entry is the one that would be moved, don't
2356 * do it... it's too complicated.
2357 */
2358 if (cur->bc_levels[level].ptr <= 1)
2359 goto out0;
2360
2361 /* Set up the left neighbor as "left". */
2362 error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
2363 if (error)
2364 goto error0;
2365
2366 /* If it's full, it can't take another entry. */
2367 lrecs = xfs_btree_get_numrecs(left);
2368 if (lrecs == cur->bc_ops->get_maxrecs(cur, level))
2369 goto out0;
2370
2371 rrecs = xfs_btree_get_numrecs(right);
2372
2373 /*
2374 * We add one entry to the left side and remove one for the right side.
2375 * Account for it here, the changes will be updated on disk and logged
2376 * later.
2377 */
2378 lrecs++;
2379 rrecs--;
2380
2381 XFS_BTREE_STATS_INC(cur, lshift);
2382 XFS_BTREE_STATS_ADD(cur, moves, 1);
2383
2384 /*
2385 * If non-leaf, copy a key and a ptr to the left block.
2386 * Log the changes to the left block.
2387 */
2388 if (level > 0) {
2389 /* It's a non-leaf. Move keys and pointers. */
2390 union xfs_btree_key *lkp; /* left btree key */
2391 union xfs_btree_ptr *lpp; /* left address pointer */
2392
2393 lkp = xfs_btree_key_addr(cur, lrecs, left);
2394 rkp = xfs_btree_key_addr(cur, 1, right);
2395
2396 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2397 rpp = xfs_btree_ptr_addr(cur, 1, right);
2398
2399 error = xfs_btree_debug_check_ptr(cur, rpp, 0, level);
2400 if (error)
2401 goto error0;
2402
2403 xfs_btree_copy_keys(cur, lkp, rkp, 1);
2404 xfs_btree_copy_ptrs(cur, lpp, rpp, 1);
2405
2406 xfs_btree_log_keys(cur, lbp, lrecs, lrecs);
2407 xfs_btree_log_ptrs(cur, lbp, lrecs, lrecs);
2408
2409 ASSERT(cur->bc_ops->keys_inorder(cur,
2410 xfs_btree_key_addr(cur, lrecs - 1, left), lkp));
2411 } else {
2412 /* It's a leaf. Move records. */
2413 union xfs_btree_rec *lrp; /* left record pointer */
2414
2415 lrp = xfs_btree_rec_addr(cur, lrecs, left);
2416 rrp = xfs_btree_rec_addr(cur, 1, right);
2417
2418 xfs_btree_copy_recs(cur, lrp, rrp, 1);
2419 xfs_btree_log_recs(cur, lbp, lrecs, lrecs);
2420
2421 ASSERT(cur->bc_ops->recs_inorder(cur,
2422 xfs_btree_rec_addr(cur, lrecs - 1, left), lrp));
2423 }
2424
2425 xfs_btree_set_numrecs(left, lrecs);
2426 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2427
2428 xfs_btree_set_numrecs(right, rrecs);
2429 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2430
2431 /*
2432 * Slide the contents of right down one entry.
2433 */
2434 XFS_BTREE_STATS_ADD(cur, moves, rrecs - 1);
2435 if (level > 0) {
2436 /* It's a nonleaf. operate on keys and ptrs */
2437 for (i = 0; i < rrecs; i++) {
2438 error = xfs_btree_debug_check_ptr(cur, rpp, i + 1, level);
2439 if (error)
2440 goto error0;
2441 }
2442
2443 xfs_btree_shift_keys(cur,
2444 xfs_btree_key_addr(cur, 2, right),
2445 -1, rrecs);
2446 xfs_btree_shift_ptrs(cur,
2447 xfs_btree_ptr_addr(cur, 2, right),
2448 -1, rrecs);
2449
2450 xfs_btree_log_keys(cur, rbp, 1, rrecs);
2451 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2452 } else {
2453 /* It's a leaf. operate on records */
2454 xfs_btree_shift_recs(cur,
2455 xfs_btree_rec_addr(cur, 2, right),
2456 -1, rrecs);
2457 xfs_btree_log_recs(cur, rbp, 1, rrecs);
2458 }
2459
2460 /*
2461 * Using a temporary cursor, update the parent key values of the
2462 * block on the left.
2463 */
2464 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2465 error = xfs_btree_dup_cursor(cur, &tcur);
2466 if (error)
2467 goto error0;
2468 i = xfs_btree_firstrec(tcur, level);
2469 if (XFS_IS_CORRUPT(tcur->bc_mp, i != 1)) {
2470 error = -EFSCORRUPTED;
2471 goto error0;
2472 }
2473
2474 error = xfs_btree_decrement(tcur, level, &i);
2475 if (error)
2476 goto error1;
2477
2478 /* Update the parent high keys of the left block, if needed. */
2479 error = xfs_btree_update_keys(tcur, level);
2480 if (error)
2481 goto error1;
2482
2483 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
2484 }
2485
2486 /* Update the parent keys of the right block. */
2487 error = xfs_btree_update_keys(cur, level);
2488 if (error)
2489 goto error0;
2490
2491 /* Slide the cursor value left one. */
2492 cur->bc_levels[level].ptr--;
2493
2494 *stat = 1;
2495 return 0;
2496
2497 out0:
2498 *stat = 0;
2499 return 0;
2500
2501 error0:
2502 return error;
2503
2504 error1:
2505 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
2506 return error;
2507 }
2508
2509 /*
2510 * Move 1 record right from cur/level if possible.
2511 * Update cur to reflect the new path.
2512 */
2513 STATIC int /* error */
xfs_btree_rshift(struct xfs_btree_cur * cur,int level,int * stat)2514 xfs_btree_rshift(
2515 struct xfs_btree_cur *cur,
2516 int level,
2517 int *stat) /* success/failure */
2518 {
2519 struct xfs_buf *lbp; /* left buffer pointer */
2520 struct xfs_btree_block *left; /* left btree block */
2521 struct xfs_buf *rbp; /* right buffer pointer */
2522 struct xfs_btree_block *right; /* right btree block */
2523 struct xfs_btree_cur *tcur; /* temporary btree cursor */
2524 union xfs_btree_ptr rptr; /* right block pointer */
2525 union xfs_btree_key *rkp; /* right btree key */
2526 int rrecs; /* right record count */
2527 int lrecs; /* left record count */
2528 int error; /* error return value */
2529 int i; /* loop counter */
2530
2531 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2532 (level == cur->bc_nlevels - 1))
2533 goto out0;
2534
2535 /* Set up variables for this block as "left". */
2536 left = xfs_btree_get_block(cur, level, &lbp);
2537
2538 #ifdef DEBUG
2539 error = xfs_btree_check_block(cur, left, level, lbp);
2540 if (error)
2541 goto error0;
2542 #endif
2543
2544 /* If we've got no right sibling then we can't shift an entry right. */
2545 xfs_btree_get_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2546 if (xfs_btree_ptr_is_null(cur, &rptr))
2547 goto out0;
2548
2549 /*
2550 * If the cursor entry is the one that would be moved, don't
2551 * do it... it's too complicated.
2552 */
2553 lrecs = xfs_btree_get_numrecs(left);
2554 if (cur->bc_levels[level].ptr >= lrecs)
2555 goto out0;
2556
2557 /* Set up the right neighbor as "right". */
2558 error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
2559 if (error)
2560 goto error0;
2561
2562 /* If it's full, it can't take another entry. */
2563 rrecs = xfs_btree_get_numrecs(right);
2564 if (rrecs == cur->bc_ops->get_maxrecs(cur, level))
2565 goto out0;
2566
2567 XFS_BTREE_STATS_INC(cur, rshift);
2568 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2569
2570 /*
2571 * Make a hole at the start of the right neighbor block, then
2572 * copy the last left block entry to the hole.
2573 */
2574 if (level > 0) {
2575 /* It's a nonleaf. make a hole in the keys and ptrs */
2576 union xfs_btree_key *lkp;
2577 union xfs_btree_ptr *lpp;
2578 union xfs_btree_ptr *rpp;
2579
2580 lkp = xfs_btree_key_addr(cur, lrecs, left);
2581 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2582 rkp = xfs_btree_key_addr(cur, 1, right);
2583 rpp = xfs_btree_ptr_addr(cur, 1, right);
2584
2585 for (i = rrecs - 1; i >= 0; i--) {
2586 error = xfs_btree_debug_check_ptr(cur, rpp, i, level);
2587 if (error)
2588 goto error0;
2589 }
2590
2591 xfs_btree_shift_keys(cur, rkp, 1, rrecs);
2592 xfs_btree_shift_ptrs(cur, rpp, 1, rrecs);
2593
2594 error = xfs_btree_debug_check_ptr(cur, lpp, 0, level);
2595 if (error)
2596 goto error0;
2597
2598 /* Now put the new data in, and log it. */
2599 xfs_btree_copy_keys(cur, rkp, lkp, 1);
2600 xfs_btree_copy_ptrs(cur, rpp, lpp, 1);
2601
2602 xfs_btree_log_keys(cur, rbp, 1, rrecs + 1);
2603 xfs_btree_log_ptrs(cur, rbp, 1, rrecs + 1);
2604
2605 ASSERT(cur->bc_ops->keys_inorder(cur, rkp,
2606 xfs_btree_key_addr(cur, 2, right)));
2607 } else {
2608 /* It's a leaf. make a hole in the records */
2609 union xfs_btree_rec *lrp;
2610 union xfs_btree_rec *rrp;
2611
2612 lrp = xfs_btree_rec_addr(cur, lrecs, left);
2613 rrp = xfs_btree_rec_addr(cur, 1, right);
2614
2615 xfs_btree_shift_recs(cur, rrp, 1, rrecs);
2616
2617 /* Now put the new data in, and log it. */
2618 xfs_btree_copy_recs(cur, rrp, lrp, 1);
2619 xfs_btree_log_recs(cur, rbp, 1, rrecs + 1);
2620 }
2621
2622 /*
2623 * Decrement and log left's numrecs, bump and log right's numrecs.
2624 */
2625 xfs_btree_set_numrecs(left, --lrecs);
2626 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2627
2628 xfs_btree_set_numrecs(right, ++rrecs);
2629 xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2630
2631 /*
2632 * Using a temporary cursor, update the parent key values of the
2633 * block on the right.
2634 */
2635 error = xfs_btree_dup_cursor(cur, &tcur);
2636 if (error)
2637 goto error0;
2638 i = xfs_btree_lastrec(tcur, level);
2639 if (XFS_IS_CORRUPT(tcur->bc_mp, i != 1)) {
2640 error = -EFSCORRUPTED;
2641 goto error0;
2642 }
2643
2644 error = xfs_btree_increment(tcur, level, &i);
2645 if (error)
2646 goto error1;
2647
2648 /* Update the parent high keys of the left block, if needed. */
2649 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2650 error = xfs_btree_update_keys(cur, level);
2651 if (error)
2652 goto error1;
2653 }
2654
2655 /* Update the parent keys of the right block. */
2656 error = xfs_btree_update_keys(tcur, level);
2657 if (error)
2658 goto error1;
2659
2660 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
2661
2662 *stat = 1;
2663 return 0;
2664
2665 out0:
2666 *stat = 0;
2667 return 0;
2668
2669 error0:
2670 return error;
2671
2672 error1:
2673 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
2674 return error;
2675 }
2676
2677 /*
2678 * Split cur/level block in half.
2679 * Return new block number and the key to its first
2680 * record (to be inserted into parent).
2681 */
2682 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)2683 __xfs_btree_split(
2684 struct xfs_btree_cur *cur,
2685 int level,
2686 union xfs_btree_ptr *ptrp,
2687 union xfs_btree_key *key,
2688 struct xfs_btree_cur **curp,
2689 int *stat) /* success/failure */
2690 {
2691 union xfs_btree_ptr lptr; /* left sibling block ptr */
2692 struct xfs_buf *lbp; /* left buffer pointer */
2693 struct xfs_btree_block *left; /* left btree block */
2694 union xfs_btree_ptr rptr; /* right sibling block ptr */
2695 struct xfs_buf *rbp; /* right buffer pointer */
2696 struct xfs_btree_block *right; /* right btree block */
2697 union xfs_btree_ptr rrptr; /* right-right sibling ptr */
2698 struct xfs_buf *rrbp; /* right-right buffer pointer */
2699 struct xfs_btree_block *rrblock; /* right-right btree block */
2700 int lrecs;
2701 int rrecs;
2702 int src_index;
2703 int error; /* error return value */
2704 int i;
2705
2706 XFS_BTREE_STATS_INC(cur, split);
2707
2708 /* Set up left block (current one). */
2709 left = xfs_btree_get_block(cur, level, &lbp);
2710
2711 #ifdef DEBUG
2712 error = xfs_btree_check_block(cur, left, level, lbp);
2713 if (error)
2714 goto error0;
2715 #endif
2716
2717 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2718
2719 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2720 error = cur->bc_ops->alloc_block(cur, &lptr, &rptr, stat);
2721 if (error)
2722 goto error0;
2723 if (*stat == 0)
2724 goto out0;
2725 XFS_BTREE_STATS_INC(cur, alloc);
2726
2727 /* Set up the new block as "right". */
2728 error = xfs_btree_get_buf_block(cur, &rptr, &right, &rbp);
2729 if (error)
2730 goto error0;
2731
2732 /* Fill in the btree header for the new right block. */
2733 xfs_btree_init_block_cur(cur, rbp, xfs_btree_get_level(left), 0);
2734
2735 /*
2736 * Split the entries between the old and the new block evenly.
2737 * Make sure that if there's an odd number of entries now, that
2738 * each new block will have the same number of entries.
2739 */
2740 lrecs = xfs_btree_get_numrecs(left);
2741 rrecs = lrecs / 2;
2742 if ((lrecs & 1) && cur->bc_levels[level].ptr <= rrecs + 1)
2743 rrecs++;
2744 src_index = (lrecs - rrecs + 1);
2745
2746 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2747
2748 /* Adjust numrecs for the later get_*_keys() calls. */
2749 lrecs -= rrecs;
2750 xfs_btree_set_numrecs(left, lrecs);
2751 xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs);
2752
2753 /*
2754 * Copy btree block entries from the left block over to the
2755 * new block, the right. Update the right block and log the
2756 * changes.
2757 */
2758 if (level > 0) {
2759 /* It's a non-leaf. Move keys and pointers. */
2760 union xfs_btree_key *lkp; /* left btree key */
2761 union xfs_btree_ptr *lpp; /* left address pointer */
2762 union xfs_btree_key *rkp; /* right btree key */
2763 union xfs_btree_ptr *rpp; /* right address pointer */
2764
2765 lkp = xfs_btree_key_addr(cur, src_index, left);
2766 lpp = xfs_btree_ptr_addr(cur, src_index, left);
2767 rkp = xfs_btree_key_addr(cur, 1, right);
2768 rpp = xfs_btree_ptr_addr(cur, 1, right);
2769
2770 for (i = src_index; i < rrecs; i++) {
2771 error = xfs_btree_debug_check_ptr(cur, lpp, i, level);
2772 if (error)
2773 goto error0;
2774 }
2775
2776 /* Copy the keys & pointers to the new block. */
2777 xfs_btree_copy_keys(cur, rkp, lkp, rrecs);
2778 xfs_btree_copy_ptrs(cur, rpp, lpp, rrecs);
2779
2780 xfs_btree_log_keys(cur, rbp, 1, rrecs);
2781 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2782
2783 /* Stash the keys of the new block for later insertion. */
2784 xfs_btree_get_node_keys(cur, right, key);
2785 } else {
2786 /* It's a leaf. Move records. */
2787 union xfs_btree_rec *lrp; /* left record pointer */
2788 union xfs_btree_rec *rrp; /* right record pointer */
2789
2790 lrp = xfs_btree_rec_addr(cur, src_index, left);
2791 rrp = xfs_btree_rec_addr(cur, 1, right);
2792
2793 /* Copy records to the new block. */
2794 xfs_btree_copy_recs(cur, rrp, lrp, rrecs);
2795 xfs_btree_log_recs(cur, rbp, 1, rrecs);
2796
2797 /* Stash the keys of the new block for later insertion. */
2798 xfs_btree_get_leaf_keys(cur, right, key);
2799 }
2800
2801 /*
2802 * Find the left block number by looking in the buffer.
2803 * Adjust sibling pointers.
2804 */
2805 xfs_btree_get_sibling(cur, left, &rrptr, XFS_BB_RIGHTSIB);
2806 xfs_btree_set_sibling(cur, right, &rrptr, XFS_BB_RIGHTSIB);
2807 xfs_btree_set_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2808 xfs_btree_set_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2809
2810 xfs_btree_log_block(cur, rbp, XFS_BB_ALL_BITS);
2811 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
2812
2813 /*
2814 * If there's a block to the new block's right, make that block
2815 * point back to right instead of to left.
2816 */
2817 if (!xfs_btree_ptr_is_null(cur, &rrptr)) {
2818 error = xfs_btree_read_buf_block(cur, &rrptr,
2819 0, &rrblock, &rrbp);
2820 if (error)
2821 goto error0;
2822 xfs_btree_set_sibling(cur, rrblock, &rptr, XFS_BB_LEFTSIB);
2823 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
2824 }
2825
2826 /* Update the parent high keys of the left block, if needed. */
2827 if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
2828 error = xfs_btree_update_keys(cur, level);
2829 if (error)
2830 goto error0;
2831 }
2832
2833 /*
2834 * If the cursor is really in the right block, move it there.
2835 * If it's just pointing past the last entry in left, then we'll
2836 * insert there, so don't change anything in that case.
2837 */
2838 if (cur->bc_levels[level].ptr > lrecs + 1) {
2839 xfs_btree_setbuf(cur, level, rbp);
2840 cur->bc_levels[level].ptr -= lrecs;
2841 }
2842 /*
2843 * If there are more levels, we'll need another cursor which refers
2844 * the right block, no matter where this cursor was.
2845 */
2846 if (level + 1 < cur->bc_nlevels) {
2847 error = xfs_btree_dup_cursor(cur, curp);
2848 if (error)
2849 goto error0;
2850 (*curp)->bc_levels[level + 1].ptr++;
2851 }
2852 *ptrp = rptr;
2853 *stat = 1;
2854 return 0;
2855 out0:
2856 *stat = 0;
2857 return 0;
2858
2859 error0:
2860 return error;
2861 }
2862
2863 #ifdef __KERNEL__
2864 struct xfs_btree_split_args {
2865 struct xfs_btree_cur *cur;
2866 int level;
2867 union xfs_btree_ptr *ptrp;
2868 union xfs_btree_key *key;
2869 struct xfs_btree_cur **curp;
2870 int *stat; /* success/failure */
2871 int result;
2872 bool kswapd; /* allocation in kswapd context */
2873 struct completion *done;
2874 struct work_struct work;
2875 };
2876
2877 /*
2878 * Stack switching interfaces for allocation
2879 */
2880 static void
xfs_btree_split_worker(struct work_struct * work)2881 xfs_btree_split_worker(
2882 struct work_struct *work)
2883 {
2884 struct xfs_btree_split_args *args = container_of(work,
2885 struct xfs_btree_split_args, work);
2886 unsigned long pflags;
2887 unsigned long new_pflags = 0;
2888
2889 /*
2890 * we are in a transaction context here, but may also be doing work
2891 * in kswapd context, and hence we may need to inherit that state
2892 * temporarily to ensure that we don't block waiting for memory reclaim
2893 * in any way.
2894 */
2895 if (args->kswapd)
2896 new_pflags |= PF_MEMALLOC | PF_KSWAPD;
2897
2898 current_set_flags_nested(&pflags, new_pflags);
2899 xfs_trans_set_context(args->cur->bc_tp);
2900
2901 args->result = __xfs_btree_split(args->cur, args->level, args->ptrp,
2902 args->key, args->curp, args->stat);
2903
2904 xfs_trans_clear_context(args->cur->bc_tp);
2905 current_restore_flags_nested(&pflags, new_pflags);
2906
2907 /*
2908 * Do not access args after complete() has run here. We don't own args
2909 * and the owner may run and free args before we return here.
2910 */
2911 complete(args->done);
2912
2913 }
2914
2915 /*
2916 * BMBT split requests often come in with little stack to work on. Push
2917 * them off to a worker thread so there is lots of stack to use. For the other
2918 * btree types, just call directly to avoid the context switch overhead here.
2919 */
2920 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)2921 xfs_btree_split(
2922 struct xfs_btree_cur *cur,
2923 int level,
2924 union xfs_btree_ptr *ptrp,
2925 union xfs_btree_key *key,
2926 struct xfs_btree_cur **curp,
2927 int *stat) /* success/failure */
2928 {
2929 struct xfs_btree_split_args args;
2930 DECLARE_COMPLETION_ONSTACK(done);
2931
2932 if (cur->bc_btnum != XFS_BTNUM_BMAP)
2933 return __xfs_btree_split(cur, level, ptrp, key, curp, stat);
2934
2935 args.cur = cur;
2936 args.level = level;
2937 args.ptrp = ptrp;
2938 args.key = key;
2939 args.curp = curp;
2940 args.stat = stat;
2941 args.done = &done;
2942 args.kswapd = current_is_kswapd();
2943 INIT_WORK_ONSTACK(&args.work, xfs_btree_split_worker);
2944 queue_work(xfs_alloc_wq, &args.work);
2945 wait_for_completion(&done);
2946 destroy_work_on_stack(&args.work);
2947 return args.result;
2948 }
2949 #else
2950 #define xfs_btree_split __xfs_btree_split
2951 #endif /* __KERNEL__ */
2952
2953
2954 /*
2955 * Copy the old inode root contents into a real block and make the
2956 * broot point to it.
2957 */
2958 int /* error */
xfs_btree_new_iroot(struct xfs_btree_cur * cur,int * logflags,int * stat)2959 xfs_btree_new_iroot(
2960 struct xfs_btree_cur *cur, /* btree cursor */
2961 int *logflags, /* logging flags for inode */
2962 int *stat) /* return status - 0 fail */
2963 {
2964 struct xfs_buf *cbp; /* buffer for cblock */
2965 struct xfs_btree_block *block; /* btree block */
2966 struct xfs_btree_block *cblock; /* child btree block */
2967 union xfs_btree_key *ckp; /* child key pointer */
2968 union xfs_btree_ptr *cpp; /* child ptr pointer */
2969 union xfs_btree_key *kp; /* pointer to btree key */
2970 union xfs_btree_ptr *pp; /* pointer to block addr */
2971 union xfs_btree_ptr nptr; /* new block addr */
2972 int level; /* btree level */
2973 int error; /* error return code */
2974 int i; /* loop counter */
2975
2976 XFS_BTREE_STATS_INC(cur, newroot);
2977
2978 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
2979
2980 level = cur->bc_nlevels - 1;
2981
2982 block = xfs_btree_get_iroot(cur);
2983 pp = xfs_btree_ptr_addr(cur, 1, block);
2984
2985 /* Allocate the new block. If we can't do it, we're toast. Give up. */
2986 error = cur->bc_ops->alloc_block(cur, pp, &nptr, stat);
2987 if (error)
2988 goto error0;
2989 if (*stat == 0)
2990 return 0;
2991
2992 XFS_BTREE_STATS_INC(cur, alloc);
2993
2994 /* Copy the root into a real block. */
2995 error = xfs_btree_get_buf_block(cur, &nptr, &cblock, &cbp);
2996 if (error)
2997 goto error0;
2998
2999 /*
3000 * we can't just memcpy() the root in for CRC enabled btree blocks.
3001 * In that case have to also ensure the blkno remains correct
3002 */
3003 memcpy(cblock, block, xfs_btree_block_len(cur));
3004 if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) {
3005 __be64 bno = cpu_to_be64(xfs_buf_daddr(cbp));
3006 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
3007 cblock->bb_u.l.bb_blkno = bno;
3008 else
3009 cblock->bb_u.s.bb_blkno = bno;
3010 }
3011
3012 be16_add_cpu(&block->bb_level, 1);
3013 xfs_btree_set_numrecs(block, 1);
3014 cur->bc_nlevels++;
3015 ASSERT(cur->bc_nlevels <= cur->bc_maxlevels);
3016 cur->bc_levels[level + 1].ptr = 1;
3017
3018 kp = xfs_btree_key_addr(cur, 1, block);
3019 ckp = xfs_btree_key_addr(cur, 1, cblock);
3020 xfs_btree_copy_keys(cur, ckp, kp, xfs_btree_get_numrecs(cblock));
3021
3022 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
3023 for (i = 0; i < be16_to_cpu(cblock->bb_numrecs); i++) {
3024 error = xfs_btree_debug_check_ptr(cur, pp, i, level);
3025 if (error)
3026 goto error0;
3027 }
3028
3029 xfs_btree_copy_ptrs(cur, cpp, pp, xfs_btree_get_numrecs(cblock));
3030
3031 error = xfs_btree_debug_check_ptr(cur, &nptr, 0, level);
3032 if (error)
3033 goto error0;
3034
3035 xfs_btree_copy_ptrs(cur, pp, &nptr, 1);
3036
3037 xfs_iroot_realloc(cur->bc_ino.ip,
3038 1 - xfs_btree_get_numrecs(cblock),
3039 cur->bc_ino.whichfork);
3040
3041 xfs_btree_setbuf(cur, level, cbp);
3042
3043 /*
3044 * Do all this logging at the end so that
3045 * the root is at the right level.
3046 */
3047 xfs_btree_log_block(cur, cbp, XFS_BB_ALL_BITS);
3048 xfs_btree_log_keys(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
3049 xfs_btree_log_ptrs(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
3050
3051 *logflags |=
3052 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_ino.whichfork);
3053 *stat = 1;
3054 return 0;
3055 error0:
3056 return error;
3057 }
3058
3059 /*
3060 * Allocate a new root block, fill it in.
3061 */
3062 STATIC int /* error */
xfs_btree_new_root(struct xfs_btree_cur * cur,int * stat)3063 xfs_btree_new_root(
3064 struct xfs_btree_cur *cur, /* btree cursor */
3065 int *stat) /* success/failure */
3066 {
3067 struct xfs_btree_block *block; /* one half of the old root block */
3068 struct xfs_buf *bp; /* buffer containing block */
3069 int error; /* error return value */
3070 struct xfs_buf *lbp; /* left buffer pointer */
3071 struct xfs_btree_block *left; /* left btree block */
3072 struct xfs_buf *nbp; /* new (root) buffer */
3073 struct xfs_btree_block *new; /* new (root) btree block */
3074 int nptr; /* new value for key index, 1 or 2 */
3075 struct xfs_buf *rbp; /* right buffer pointer */
3076 struct xfs_btree_block *right; /* right btree block */
3077 union xfs_btree_ptr rptr;
3078 union xfs_btree_ptr lptr;
3079
3080 XFS_BTREE_STATS_INC(cur, newroot);
3081
3082 /* initialise our start point from the cursor */
3083 cur->bc_ops->init_ptr_from_cur(cur, &rptr);
3084
3085 /* Allocate the new block. If we can't do it, we're toast. Give up. */
3086 error = cur->bc_ops->alloc_block(cur, &rptr, &lptr, stat);
3087 if (error)
3088 goto error0;
3089 if (*stat == 0)
3090 goto out0;
3091 XFS_BTREE_STATS_INC(cur, alloc);
3092
3093 /* Set up the new block. */
3094 error = xfs_btree_get_buf_block(cur, &lptr, &new, &nbp);
3095 if (error)
3096 goto error0;
3097
3098 /* Set the root in the holding structure increasing the level by 1. */
3099 cur->bc_ops->set_root(cur, &lptr, 1);
3100
3101 /*
3102 * At the previous root level there are now two blocks: the old root,
3103 * and the new block generated when it was split. We don't know which
3104 * one the cursor is pointing at, so we set up variables "left" and
3105 * "right" for each case.
3106 */
3107 block = xfs_btree_get_block(cur, cur->bc_nlevels - 1, &bp);
3108
3109 #ifdef DEBUG
3110 error = xfs_btree_check_block(cur, block, cur->bc_nlevels - 1, bp);
3111 if (error)
3112 goto error0;
3113 #endif
3114
3115 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
3116 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
3117 /* Our block is left, pick up the right block. */
3118 lbp = bp;
3119 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
3120 left = block;
3121 error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
3122 if (error)
3123 goto error0;
3124 bp = rbp;
3125 nptr = 1;
3126 } else {
3127 /* Our block is right, pick up the left block. */
3128 rbp = bp;
3129 xfs_btree_buf_to_ptr(cur, rbp, &rptr);
3130 right = block;
3131 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
3132 error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
3133 if (error)
3134 goto error0;
3135 bp = lbp;
3136 nptr = 2;
3137 }
3138
3139 /* Fill in the new block's btree header and log it. */
3140 xfs_btree_init_block_cur(cur, nbp, cur->bc_nlevels, 2);
3141 xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS);
3142 ASSERT(!xfs_btree_ptr_is_null(cur, &lptr) &&
3143 !xfs_btree_ptr_is_null(cur, &rptr));
3144
3145 /* Fill in the key data in the new root. */
3146 if (xfs_btree_get_level(left) > 0) {
3147 /*
3148 * Get the keys for the left block's keys and put them directly
3149 * in the parent block. Do the same for the right block.
3150 */
3151 xfs_btree_get_node_keys(cur, left,
3152 xfs_btree_key_addr(cur, 1, new));
3153 xfs_btree_get_node_keys(cur, right,
3154 xfs_btree_key_addr(cur, 2, new));
3155 } else {
3156 /*
3157 * Get the keys for the left block's records and put them
3158 * directly in the parent block. Do the same for the right
3159 * block.
3160 */
3161 xfs_btree_get_leaf_keys(cur, left,
3162 xfs_btree_key_addr(cur, 1, new));
3163 xfs_btree_get_leaf_keys(cur, right,
3164 xfs_btree_key_addr(cur, 2, new));
3165 }
3166 xfs_btree_log_keys(cur, nbp, 1, 2);
3167
3168 /* Fill in the pointer data in the new root. */
3169 xfs_btree_copy_ptrs(cur,
3170 xfs_btree_ptr_addr(cur, 1, new), &lptr, 1);
3171 xfs_btree_copy_ptrs(cur,
3172 xfs_btree_ptr_addr(cur, 2, new), &rptr, 1);
3173 xfs_btree_log_ptrs(cur, nbp, 1, 2);
3174
3175 /* Fix up the cursor. */
3176 xfs_btree_setbuf(cur, cur->bc_nlevels, nbp);
3177 cur->bc_levels[cur->bc_nlevels].ptr = nptr;
3178 cur->bc_nlevels++;
3179 ASSERT(cur->bc_nlevels <= cur->bc_maxlevels);
3180 *stat = 1;
3181 return 0;
3182 error0:
3183 return error;
3184 out0:
3185 *stat = 0;
3186 return 0;
3187 }
3188
3189 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)3190 xfs_btree_make_block_unfull(
3191 struct xfs_btree_cur *cur, /* btree cursor */
3192 int level, /* btree level */
3193 int numrecs,/* # of recs in block */
3194 int *oindex,/* old tree index */
3195 int *index, /* new tree index */
3196 union xfs_btree_ptr *nptr, /* new btree ptr */
3197 struct xfs_btree_cur **ncur, /* new btree cursor */
3198 union xfs_btree_key *key, /* key of new block */
3199 int *stat)
3200 {
3201 int error = 0;
3202
3203 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
3204 level == cur->bc_nlevels - 1) {
3205 struct xfs_inode *ip = cur->bc_ino.ip;
3206
3207 if (numrecs < cur->bc_ops->get_dmaxrecs(cur, level)) {
3208 /* A root block that can be made bigger. */
3209 xfs_iroot_realloc(ip, 1, cur->bc_ino.whichfork);
3210 *stat = 1;
3211 } else {
3212 /* A root block that needs replacing */
3213 int logflags = 0;
3214
3215 error = xfs_btree_new_iroot(cur, &logflags, stat);
3216 if (error || *stat == 0)
3217 return error;
3218
3219 xfs_trans_log_inode(cur->bc_tp, ip, logflags);
3220 }
3221
3222 return 0;
3223 }
3224
3225 /* First, try shifting an entry to the right neighbor. */
3226 error = xfs_btree_rshift(cur, level, stat);
3227 if (error || *stat)
3228 return error;
3229
3230 /* Next, try shifting an entry to the left neighbor. */
3231 error = xfs_btree_lshift(cur, level, stat);
3232 if (error)
3233 return error;
3234
3235 if (*stat) {
3236 *oindex = *index = cur->bc_levels[level].ptr;
3237 return 0;
3238 }
3239
3240 /*
3241 * Next, try splitting the current block in half.
3242 *
3243 * If this works we have to re-set our variables because we
3244 * could be in a different block now.
3245 */
3246 error = xfs_btree_split(cur, level, nptr, key, ncur, stat);
3247 if (error || *stat == 0)
3248 return error;
3249
3250
3251 *index = cur->bc_levels[level].ptr;
3252 return 0;
3253 }
3254
3255 /*
3256 * Insert one record/level. Return information to the caller
3257 * allowing the next level up to proceed if necessary.
3258 */
3259 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)3260 xfs_btree_insrec(
3261 struct xfs_btree_cur *cur, /* btree cursor */
3262 int level, /* level to insert record at */
3263 union xfs_btree_ptr *ptrp, /* i/o: block number inserted */
3264 union xfs_btree_rec *rec, /* record to insert */
3265 union xfs_btree_key *key, /* i/o: block key for ptrp */
3266 struct xfs_btree_cur **curp, /* output: new cursor replacing cur */
3267 int *stat) /* success/failure */
3268 {
3269 struct xfs_btree_block *block; /* btree block */
3270 struct xfs_buf *bp; /* buffer for block */
3271 union xfs_btree_ptr nptr; /* new block ptr */
3272 struct xfs_btree_cur *ncur = NULL; /* new btree cursor */
3273 union xfs_btree_key nkey; /* new block key */
3274 union xfs_btree_key *lkey;
3275 int optr; /* old key/record index */
3276 int ptr; /* key/record index */
3277 int numrecs;/* number of records */
3278 int error; /* error return value */
3279 int i;
3280 xfs_daddr_t old_bn;
3281
3282 ncur = NULL;
3283 lkey = &nkey;
3284
3285 /*
3286 * If we have an external root pointer, and we've made it to the
3287 * root level, allocate a new root block and we're done.
3288 */
3289 if (!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
3290 (level >= cur->bc_nlevels)) {
3291 error = xfs_btree_new_root(cur, stat);
3292 xfs_btree_set_ptr_null(cur, ptrp);
3293
3294 return error;
3295 }
3296
3297 /* If we're off the left edge, return failure. */
3298 ptr = cur->bc_levels[level].ptr;
3299 if (ptr == 0) {
3300 *stat = 0;
3301 return 0;
3302 }
3303
3304 optr = ptr;
3305
3306 XFS_BTREE_STATS_INC(cur, insrec);
3307
3308 /* Get pointers to the btree buffer and block. */
3309 block = xfs_btree_get_block(cur, level, &bp);
3310 old_bn = bp ? xfs_buf_daddr(bp) : XFS_BUF_DADDR_NULL;
3311 numrecs = xfs_btree_get_numrecs(block);
3312
3313 #ifdef DEBUG
3314 error = xfs_btree_check_block(cur, block, level, bp);
3315 if (error)
3316 goto error0;
3317
3318 /* Check that the new entry is being inserted in the right place. */
3319 if (ptr <= numrecs) {
3320 if (level == 0) {
3321 ASSERT(cur->bc_ops->recs_inorder(cur, rec,
3322 xfs_btree_rec_addr(cur, ptr, block)));
3323 } else {
3324 ASSERT(cur->bc_ops->keys_inorder(cur, key,
3325 xfs_btree_key_addr(cur, ptr, block)));
3326 }
3327 }
3328 #endif
3329
3330 /*
3331 * If the block is full, we can't insert the new entry until we
3332 * make the block un-full.
3333 */
3334 xfs_btree_set_ptr_null(cur, &nptr);
3335 if (numrecs == cur->bc_ops->get_maxrecs(cur, level)) {
3336 error = xfs_btree_make_block_unfull(cur, level, numrecs,
3337 &optr, &ptr, &nptr, &ncur, lkey, stat);
3338 if (error || *stat == 0)
3339 goto error0;
3340 }
3341
3342 /*
3343 * The current block may have changed if the block was
3344 * previously full and we have just made space in it.
3345 */
3346 block = xfs_btree_get_block(cur, level, &bp);
3347 numrecs = xfs_btree_get_numrecs(block);
3348
3349 #ifdef DEBUG
3350 error = xfs_btree_check_block(cur, block, level, bp);
3351 if (error)
3352 goto error0;
3353 #endif
3354
3355 /*
3356 * At this point we know there's room for our new entry in the block
3357 * we're pointing at.
3358 */
3359 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr + 1);
3360
3361 if (level > 0) {
3362 /* It's a nonleaf. make a hole in the keys and ptrs */
3363 union xfs_btree_key *kp;
3364 union xfs_btree_ptr *pp;
3365
3366 kp = xfs_btree_key_addr(cur, ptr, block);
3367 pp = xfs_btree_ptr_addr(cur, ptr, block);
3368
3369 for (i = numrecs - ptr; i >= 0; i--) {
3370 error = xfs_btree_debug_check_ptr(cur, pp, i, level);
3371 if (error)
3372 goto error0;
3373 }
3374
3375 xfs_btree_shift_keys(cur, kp, 1, numrecs - ptr + 1);
3376 xfs_btree_shift_ptrs(cur, pp, 1, numrecs - ptr + 1);
3377
3378 error = xfs_btree_debug_check_ptr(cur, ptrp, 0, level);
3379 if (error)
3380 goto error0;
3381
3382 /* Now put the new data in, bump numrecs and log it. */
3383 xfs_btree_copy_keys(cur, kp, key, 1);
3384 xfs_btree_copy_ptrs(cur, pp, ptrp, 1);
3385 numrecs++;
3386 xfs_btree_set_numrecs(block, numrecs);
3387 xfs_btree_log_ptrs(cur, bp, ptr, numrecs);
3388 xfs_btree_log_keys(cur, bp, ptr, numrecs);
3389 #ifdef DEBUG
3390 if (ptr < numrecs) {
3391 ASSERT(cur->bc_ops->keys_inorder(cur, kp,
3392 xfs_btree_key_addr(cur, ptr + 1, block)));
3393 }
3394 #endif
3395 } else {
3396 /* It's a leaf. make a hole in the records */
3397 union xfs_btree_rec *rp;
3398
3399 rp = xfs_btree_rec_addr(cur, ptr, block);
3400
3401 xfs_btree_shift_recs(cur, rp, 1, numrecs - ptr + 1);
3402
3403 /* Now put the new data in, bump numrecs and log it. */
3404 xfs_btree_copy_recs(cur, rp, rec, 1);
3405 xfs_btree_set_numrecs(block, ++numrecs);
3406 xfs_btree_log_recs(cur, bp, ptr, numrecs);
3407 #ifdef DEBUG
3408 if (ptr < numrecs) {
3409 ASSERT(cur->bc_ops->recs_inorder(cur, rp,
3410 xfs_btree_rec_addr(cur, ptr + 1, block)));
3411 }
3412 #endif
3413 }
3414
3415 /* Log the new number of records in the btree header. */
3416 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
3417
3418 /*
3419 * If we just inserted into a new tree block, we have to
3420 * recalculate nkey here because nkey is out of date.
3421 *
3422 * Otherwise we're just updating an existing block (having shoved
3423 * some records into the new tree block), so use the regular key
3424 * update mechanism.
3425 */
3426 if (bp && xfs_buf_daddr(bp) != old_bn) {
3427 xfs_btree_get_keys(cur, block, lkey);
3428 } else if (xfs_btree_needs_key_update(cur, optr)) {
3429 error = xfs_btree_update_keys(cur, level);
3430 if (error)
3431 goto error0;
3432 }
3433
3434 /*
3435 * If we are tracking the last record in the tree and
3436 * we are at the far right edge of the tree, update it.
3437 */
3438 if (xfs_btree_is_lastrec(cur, block, level)) {
3439 cur->bc_ops->update_lastrec(cur, block, rec,
3440 ptr, LASTREC_INSREC);
3441 }
3442
3443 /*
3444 * Return the new block number, if any.
3445 * If there is one, give back a record value and a cursor too.
3446 */
3447 *ptrp = nptr;
3448 if (!xfs_btree_ptr_is_null(cur, &nptr)) {
3449 xfs_btree_copy_keys(cur, key, lkey, 1);
3450 *curp = ncur;
3451 }
3452
3453 *stat = 1;
3454 return 0;
3455
3456 error0:
3457 if (ncur)
3458 xfs_btree_del_cursor(ncur, error);
3459 return error;
3460 }
3461
3462 /*
3463 * Insert the record at the point referenced by cur.
3464 *
3465 * A multi-level split of the tree on insert will invalidate the original
3466 * cursor. All callers of this function should assume that the cursor is
3467 * no longer valid and revalidate it.
3468 */
3469 int
xfs_btree_insert(struct xfs_btree_cur * cur,int * stat)3470 xfs_btree_insert(
3471 struct xfs_btree_cur *cur,
3472 int *stat)
3473 {
3474 int error; /* error return value */
3475 int i; /* result value, 0 for failure */
3476 int level; /* current level number in btree */
3477 union xfs_btree_ptr nptr; /* new block number (split result) */
3478 struct xfs_btree_cur *ncur; /* new cursor (split result) */
3479 struct xfs_btree_cur *pcur; /* previous level's cursor */
3480 union xfs_btree_key bkey; /* key of block to insert */
3481 union xfs_btree_key *key;
3482 union xfs_btree_rec rec; /* record to insert */
3483
3484 level = 0;
3485 ncur = NULL;
3486 pcur = cur;
3487 key = &bkey;
3488
3489 xfs_btree_set_ptr_null(cur, &nptr);
3490
3491 /* Make a key out of the record data to be inserted, and save it. */
3492 cur->bc_ops->init_rec_from_cur(cur, &rec);
3493 cur->bc_ops->init_key_from_rec(key, &rec);
3494
3495 /*
3496 * Loop going up the tree, starting at the leaf level.
3497 * Stop when we don't get a split block, that must mean that
3498 * the insert is finished with this level.
3499 */
3500 do {
3501 /*
3502 * Insert nrec/nptr into this level of the tree.
3503 * Note if we fail, nptr will be null.
3504 */
3505 error = xfs_btree_insrec(pcur, level, &nptr, &rec, key,
3506 &ncur, &i);
3507 if (error) {
3508 if (pcur != cur)
3509 xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR);
3510 goto error0;
3511 }
3512
3513 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
3514 error = -EFSCORRUPTED;
3515 goto error0;
3516 }
3517 level++;
3518
3519 /*
3520 * See if the cursor we just used is trash.
3521 * Can't trash the caller's cursor, but otherwise we should
3522 * if ncur is a new cursor or we're about to be done.
3523 */
3524 if (pcur != cur &&
3525 (ncur || xfs_btree_ptr_is_null(cur, &nptr))) {
3526 /* Save the state from the cursor before we trash it */
3527 if (cur->bc_ops->update_cursor)
3528 cur->bc_ops->update_cursor(pcur, cur);
3529 cur->bc_nlevels = pcur->bc_nlevels;
3530 xfs_btree_del_cursor(pcur, XFS_BTREE_NOERROR);
3531 }
3532 /* If we got a new cursor, switch to it. */
3533 if (ncur) {
3534 pcur = ncur;
3535 ncur = NULL;
3536 }
3537 } while (!xfs_btree_ptr_is_null(cur, &nptr));
3538
3539 *stat = i;
3540 return 0;
3541 error0:
3542 return error;
3543 }
3544
3545 /*
3546 * Try to merge a non-leaf block back into the inode root.
3547 *
3548 * Note: the killroot names comes from the fact that we're effectively
3549 * killing the old root block. But because we can't just delete the
3550 * inode we have to copy the single block it was pointing to into the
3551 * inode.
3552 */
3553 STATIC int
xfs_btree_kill_iroot(struct xfs_btree_cur * cur)3554 xfs_btree_kill_iroot(
3555 struct xfs_btree_cur *cur)
3556 {
3557 int whichfork = cur->bc_ino.whichfork;
3558 struct xfs_inode *ip = cur->bc_ino.ip;
3559 struct xfs_ifork *ifp = xfs_ifork_ptr(ip, whichfork);
3560 struct xfs_btree_block *block;
3561 struct xfs_btree_block *cblock;
3562 union xfs_btree_key *kp;
3563 union xfs_btree_key *ckp;
3564 union xfs_btree_ptr *pp;
3565 union xfs_btree_ptr *cpp;
3566 struct xfs_buf *cbp;
3567 int level;
3568 int index;
3569 int numrecs;
3570 int error;
3571 #ifdef DEBUG
3572 union xfs_btree_ptr ptr;
3573 #endif
3574 int i;
3575
3576 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
3577 ASSERT(cur->bc_nlevels > 1);
3578
3579 /*
3580 * Don't deal with the root block needs to be a leaf case.
3581 * We're just going to turn the thing back into extents anyway.
3582 */
3583 level = cur->bc_nlevels - 1;
3584 if (level == 1)
3585 goto out0;
3586
3587 /*
3588 * Give up if the root has multiple children.
3589 */
3590 block = xfs_btree_get_iroot(cur);
3591 if (xfs_btree_get_numrecs(block) != 1)
3592 goto out0;
3593
3594 cblock = xfs_btree_get_block(cur, level - 1, &cbp);
3595 numrecs = xfs_btree_get_numrecs(cblock);
3596
3597 /*
3598 * Only do this if the next level will fit.
3599 * Then the data must be copied up to the inode,
3600 * instead of freeing the root you free the next level.
3601 */
3602 if (numrecs > cur->bc_ops->get_dmaxrecs(cur, level))
3603 goto out0;
3604
3605 XFS_BTREE_STATS_INC(cur, killroot);
3606
3607 #ifdef DEBUG
3608 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
3609 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
3610 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
3611 ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
3612 #endif
3613
3614 index = numrecs - cur->bc_ops->get_maxrecs(cur, level);
3615 if (index) {
3616 xfs_iroot_realloc(cur->bc_ino.ip, index,
3617 cur->bc_ino.whichfork);
3618 block = ifp->if_broot;
3619 }
3620
3621 be16_add_cpu(&block->bb_numrecs, index);
3622 ASSERT(block->bb_numrecs == cblock->bb_numrecs);
3623
3624 kp = xfs_btree_key_addr(cur, 1, block);
3625 ckp = xfs_btree_key_addr(cur, 1, cblock);
3626 xfs_btree_copy_keys(cur, kp, ckp, numrecs);
3627
3628 pp = xfs_btree_ptr_addr(cur, 1, block);
3629 cpp = xfs_btree_ptr_addr(cur, 1, cblock);
3630
3631 for (i = 0; i < numrecs; i++) {
3632 error = xfs_btree_debug_check_ptr(cur, cpp, i, level - 1);
3633 if (error)
3634 return error;
3635 }
3636
3637 xfs_btree_copy_ptrs(cur, pp, cpp, numrecs);
3638
3639 error = xfs_btree_free_block(cur, cbp);
3640 if (error)
3641 return error;
3642
3643 cur->bc_levels[level - 1].bp = NULL;
3644 be16_add_cpu(&block->bb_level, -1);
3645 xfs_trans_log_inode(cur->bc_tp, ip,
3646 XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_ino.whichfork));
3647 cur->bc_nlevels--;
3648 out0:
3649 return 0;
3650 }
3651
3652 /*
3653 * Kill the current root node, and replace it with it's only child node.
3654 */
3655 STATIC int
xfs_btree_kill_root(struct xfs_btree_cur * cur,struct xfs_buf * bp,int level,union xfs_btree_ptr * newroot)3656 xfs_btree_kill_root(
3657 struct xfs_btree_cur *cur,
3658 struct xfs_buf *bp,
3659 int level,
3660 union xfs_btree_ptr *newroot)
3661 {
3662 int error;
3663
3664 XFS_BTREE_STATS_INC(cur, killroot);
3665
3666 /*
3667 * Update the root pointer, decreasing the level by 1 and then
3668 * free the old root.
3669 */
3670 cur->bc_ops->set_root(cur, newroot, -1);
3671
3672 error = xfs_btree_free_block(cur, bp);
3673 if (error)
3674 return error;
3675
3676 cur->bc_levels[level].bp = NULL;
3677 cur->bc_levels[level].ra = 0;
3678 cur->bc_nlevels--;
3679
3680 return 0;
3681 }
3682
3683 STATIC int
xfs_btree_dec_cursor(struct xfs_btree_cur * cur,int level,int * stat)3684 xfs_btree_dec_cursor(
3685 struct xfs_btree_cur *cur,
3686 int level,
3687 int *stat)
3688 {
3689 int error;
3690 int i;
3691
3692 if (level > 0) {
3693 error = xfs_btree_decrement(cur, level, &i);
3694 if (error)
3695 return error;
3696 }
3697
3698 *stat = 1;
3699 return 0;
3700 }
3701
3702 /*
3703 * Single level of the btree record deletion routine.
3704 * Delete record pointed to by cur/level.
3705 * Remove the record from its block then rebalance the tree.
3706 * Return 0 for error, 1 for done, 2 to go on to the next level.
3707 */
3708 STATIC int /* error */
xfs_btree_delrec(struct xfs_btree_cur * cur,int level,int * stat)3709 xfs_btree_delrec(
3710 struct xfs_btree_cur *cur, /* btree cursor */
3711 int level, /* level removing record from */
3712 int *stat) /* fail/done/go-on */
3713 {
3714 struct xfs_btree_block *block; /* btree block */
3715 union xfs_btree_ptr cptr; /* current block ptr */
3716 struct xfs_buf *bp; /* buffer for block */
3717 int error; /* error return value */
3718 int i; /* loop counter */
3719 union xfs_btree_ptr lptr; /* left sibling block ptr */
3720 struct xfs_buf *lbp; /* left buffer pointer */
3721 struct xfs_btree_block *left; /* left btree block */
3722 int lrecs = 0; /* left record count */
3723 int ptr; /* key/record index */
3724 union xfs_btree_ptr rptr; /* right sibling block ptr */
3725 struct xfs_buf *rbp; /* right buffer pointer */
3726 struct xfs_btree_block *right; /* right btree block */
3727 struct xfs_btree_block *rrblock; /* right-right btree block */
3728 struct xfs_buf *rrbp; /* right-right buffer pointer */
3729 int rrecs = 0; /* right record count */
3730 struct xfs_btree_cur *tcur; /* temporary btree cursor */
3731 int numrecs; /* temporary numrec count */
3732
3733 tcur = NULL;
3734
3735 /* Get the index of the entry being deleted, check for nothing there. */
3736 ptr = cur->bc_levels[level].ptr;
3737 if (ptr == 0) {
3738 *stat = 0;
3739 return 0;
3740 }
3741
3742 /* Get the buffer & block containing the record or key/ptr. */
3743 block = xfs_btree_get_block(cur, level, &bp);
3744 numrecs = xfs_btree_get_numrecs(block);
3745
3746 #ifdef DEBUG
3747 error = xfs_btree_check_block(cur, block, level, bp);
3748 if (error)
3749 goto error0;
3750 #endif
3751
3752 /* Fail if we're off the end of the block. */
3753 if (ptr > numrecs) {
3754 *stat = 0;
3755 return 0;
3756 }
3757
3758 XFS_BTREE_STATS_INC(cur, delrec);
3759 XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr);
3760
3761 /* Excise the entries being deleted. */
3762 if (level > 0) {
3763 /* It's a nonleaf. operate on keys and ptrs */
3764 union xfs_btree_key *lkp;
3765 union xfs_btree_ptr *lpp;
3766
3767 lkp = xfs_btree_key_addr(cur, ptr + 1, block);
3768 lpp = xfs_btree_ptr_addr(cur, ptr + 1, block);
3769
3770 for (i = 0; i < numrecs - ptr; i++) {
3771 error = xfs_btree_debug_check_ptr(cur, lpp, i, level);
3772 if (error)
3773 goto error0;
3774 }
3775
3776 if (ptr < numrecs) {
3777 xfs_btree_shift_keys(cur, lkp, -1, numrecs - ptr);
3778 xfs_btree_shift_ptrs(cur, lpp, -1, numrecs - ptr);
3779 xfs_btree_log_keys(cur, bp, ptr, numrecs - 1);
3780 xfs_btree_log_ptrs(cur, bp, ptr, numrecs - 1);
3781 }
3782 } else {
3783 /* It's a leaf. operate on records */
3784 if (ptr < numrecs) {
3785 xfs_btree_shift_recs(cur,
3786 xfs_btree_rec_addr(cur, ptr + 1, block),
3787 -1, numrecs - ptr);
3788 xfs_btree_log_recs(cur, bp, ptr, numrecs - 1);
3789 }
3790 }
3791
3792 /*
3793 * Decrement and log the number of entries in the block.
3794 */
3795 xfs_btree_set_numrecs(block, --numrecs);
3796 xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
3797
3798 /*
3799 * If we are tracking the last record in the tree and
3800 * we are at the far right edge of the tree, update it.
3801 */
3802 if (xfs_btree_is_lastrec(cur, block, level)) {
3803 cur->bc_ops->update_lastrec(cur, block, NULL,
3804 ptr, LASTREC_DELREC);
3805 }
3806
3807 /*
3808 * We're at the root level. First, shrink the root block in-memory.
3809 * Try to get rid of the next level down. If we can't then there's
3810 * nothing left to do.
3811 */
3812 if (level == cur->bc_nlevels - 1) {
3813 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3814 xfs_iroot_realloc(cur->bc_ino.ip, -1,
3815 cur->bc_ino.whichfork);
3816
3817 error = xfs_btree_kill_iroot(cur);
3818 if (error)
3819 goto error0;
3820
3821 error = xfs_btree_dec_cursor(cur, level, stat);
3822 if (error)
3823 goto error0;
3824 *stat = 1;
3825 return 0;
3826 }
3827
3828 /*
3829 * If this is the root level, and there's only one entry left,
3830 * and it's NOT the leaf level, then we can get rid of this
3831 * level.
3832 */
3833 if (numrecs == 1 && level > 0) {
3834 union xfs_btree_ptr *pp;
3835 /*
3836 * pp is still set to the first pointer in the block.
3837 * Make it the new root of the btree.
3838 */
3839 pp = xfs_btree_ptr_addr(cur, 1, block);
3840 error = xfs_btree_kill_root(cur, bp, level, pp);
3841 if (error)
3842 goto error0;
3843 } else if (level > 0) {
3844 error = xfs_btree_dec_cursor(cur, level, stat);
3845 if (error)
3846 goto error0;
3847 }
3848 *stat = 1;
3849 return 0;
3850 }
3851
3852 /*
3853 * If we deleted the leftmost entry in the block, update the
3854 * key values above us in the tree.
3855 */
3856 if (xfs_btree_needs_key_update(cur, ptr)) {
3857 error = xfs_btree_update_keys(cur, level);
3858 if (error)
3859 goto error0;
3860 }
3861
3862 /*
3863 * If the number of records remaining in the block is at least
3864 * the minimum, we're done.
3865 */
3866 if (numrecs >= cur->bc_ops->get_minrecs(cur, level)) {
3867 error = xfs_btree_dec_cursor(cur, level, stat);
3868 if (error)
3869 goto error0;
3870 return 0;
3871 }
3872
3873 /*
3874 * Otherwise, we have to move some records around to keep the
3875 * tree balanced. Look at the left and right sibling blocks to
3876 * see if we can re-balance by moving only one record.
3877 */
3878 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
3879 xfs_btree_get_sibling(cur, block, &lptr, XFS_BB_LEFTSIB);
3880
3881 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3882 /*
3883 * One child of root, need to get a chance to copy its contents
3884 * into the root and delete it. Can't go up to next level,
3885 * there's nothing to delete there.
3886 */
3887 if (xfs_btree_ptr_is_null(cur, &rptr) &&
3888 xfs_btree_ptr_is_null(cur, &lptr) &&
3889 level == cur->bc_nlevels - 2) {
3890 error = xfs_btree_kill_iroot(cur);
3891 if (!error)
3892 error = xfs_btree_dec_cursor(cur, level, stat);
3893 if (error)
3894 goto error0;
3895 return 0;
3896 }
3897 }
3898
3899 ASSERT(!xfs_btree_ptr_is_null(cur, &rptr) ||
3900 !xfs_btree_ptr_is_null(cur, &lptr));
3901
3902 /*
3903 * Duplicate the cursor so our btree manipulations here won't
3904 * disrupt the next level up.
3905 */
3906 error = xfs_btree_dup_cursor(cur, &tcur);
3907 if (error)
3908 goto error0;
3909
3910 /*
3911 * If there's a right sibling, see if it's ok to shift an entry
3912 * out of it.
3913 */
3914 if (!xfs_btree_ptr_is_null(cur, &rptr)) {
3915 /*
3916 * Move the temp cursor to the last entry in the next block.
3917 * Actually any entry but the first would suffice.
3918 */
3919 i = xfs_btree_lastrec(tcur, level);
3920 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
3921 error = -EFSCORRUPTED;
3922 goto error0;
3923 }
3924
3925 error = xfs_btree_increment(tcur, level, &i);
3926 if (error)
3927 goto error0;
3928 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
3929 error = -EFSCORRUPTED;
3930 goto error0;
3931 }
3932
3933 i = xfs_btree_lastrec(tcur, level);
3934 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
3935 error = -EFSCORRUPTED;
3936 goto error0;
3937 }
3938
3939 /* Grab a pointer to the block. */
3940 right = xfs_btree_get_block(tcur, level, &rbp);
3941 #ifdef DEBUG
3942 error = xfs_btree_check_block(tcur, right, level, rbp);
3943 if (error)
3944 goto error0;
3945 #endif
3946 /* Grab the current block number, for future use. */
3947 xfs_btree_get_sibling(tcur, right, &cptr, XFS_BB_LEFTSIB);
3948
3949 /*
3950 * If right block is full enough so that removing one entry
3951 * won't make it too empty, and left-shifting an entry out
3952 * of right to us works, we're done.
3953 */
3954 if (xfs_btree_get_numrecs(right) - 1 >=
3955 cur->bc_ops->get_minrecs(tcur, level)) {
3956 error = xfs_btree_lshift(tcur, level, &i);
3957 if (error)
3958 goto error0;
3959 if (i) {
3960 ASSERT(xfs_btree_get_numrecs(block) >=
3961 cur->bc_ops->get_minrecs(tcur, level));
3962
3963 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3964 tcur = NULL;
3965
3966 error = xfs_btree_dec_cursor(cur, level, stat);
3967 if (error)
3968 goto error0;
3969 return 0;
3970 }
3971 }
3972
3973 /*
3974 * Otherwise, grab the number of records in right for
3975 * future reference, and fix up the temp cursor to point
3976 * to our block again (last record).
3977 */
3978 rrecs = xfs_btree_get_numrecs(right);
3979 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3980 i = xfs_btree_firstrec(tcur, level);
3981 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
3982 error = -EFSCORRUPTED;
3983 goto error0;
3984 }
3985
3986 error = xfs_btree_decrement(tcur, level, &i);
3987 if (error)
3988 goto error0;
3989 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
3990 error = -EFSCORRUPTED;
3991 goto error0;
3992 }
3993 }
3994 }
3995
3996 /*
3997 * If there's a left sibling, see if it's ok to shift an entry
3998 * out of it.
3999 */
4000 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
4001 /*
4002 * Move the temp cursor to the first entry in the
4003 * previous block.
4004 */
4005 i = xfs_btree_firstrec(tcur, level);
4006 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
4007 error = -EFSCORRUPTED;
4008 goto error0;
4009 }
4010
4011 error = xfs_btree_decrement(tcur, level, &i);
4012 if (error)
4013 goto error0;
4014 i = xfs_btree_firstrec(tcur, level);
4015 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
4016 error = -EFSCORRUPTED;
4017 goto error0;
4018 }
4019
4020 /* Grab a pointer to the block. */
4021 left = xfs_btree_get_block(tcur, level, &lbp);
4022 #ifdef DEBUG
4023 error = xfs_btree_check_block(cur, left, level, lbp);
4024 if (error)
4025 goto error0;
4026 #endif
4027 /* Grab the current block number, for future use. */
4028 xfs_btree_get_sibling(tcur, left, &cptr, XFS_BB_RIGHTSIB);
4029
4030 /*
4031 * If left block is full enough so that removing one entry
4032 * won't make it too empty, and right-shifting an entry out
4033 * of left to us works, we're done.
4034 */
4035 if (xfs_btree_get_numrecs(left) - 1 >=
4036 cur->bc_ops->get_minrecs(tcur, level)) {
4037 error = xfs_btree_rshift(tcur, level, &i);
4038 if (error)
4039 goto error0;
4040 if (i) {
4041 ASSERT(xfs_btree_get_numrecs(block) >=
4042 cur->bc_ops->get_minrecs(tcur, level));
4043 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
4044 tcur = NULL;
4045 if (level == 0)
4046 cur->bc_levels[0].ptr++;
4047
4048 *stat = 1;
4049 return 0;
4050 }
4051 }
4052
4053 /*
4054 * Otherwise, grab the number of records in right for
4055 * future reference.
4056 */
4057 lrecs = xfs_btree_get_numrecs(left);
4058 }
4059
4060 /* Delete the temp cursor, we're done with it. */
4061 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
4062 tcur = NULL;
4063
4064 /* If here, we need to do a join to keep the tree balanced. */
4065 ASSERT(!xfs_btree_ptr_is_null(cur, &cptr));
4066
4067 if (!xfs_btree_ptr_is_null(cur, &lptr) &&
4068 lrecs + xfs_btree_get_numrecs(block) <=
4069 cur->bc_ops->get_maxrecs(cur, level)) {
4070 /*
4071 * Set "right" to be the starting block,
4072 * "left" to be the left neighbor.
4073 */
4074 rptr = cptr;
4075 right = block;
4076 rbp = bp;
4077 error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
4078 if (error)
4079 goto error0;
4080
4081 /*
4082 * If that won't work, see if we can join with the right neighbor block.
4083 */
4084 } else if (!xfs_btree_ptr_is_null(cur, &rptr) &&
4085 rrecs + xfs_btree_get_numrecs(block) <=
4086 cur->bc_ops->get_maxrecs(cur, level)) {
4087 /*
4088 * Set "left" to be the starting block,
4089 * "right" to be the right neighbor.
4090 */
4091 lptr = cptr;
4092 left = block;
4093 lbp = bp;
4094 error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
4095 if (error)
4096 goto error0;
4097
4098 /*
4099 * Otherwise, we can't fix the imbalance.
4100 * Just return. This is probably a logic error, but it's not fatal.
4101 */
4102 } else {
4103 error = xfs_btree_dec_cursor(cur, level, stat);
4104 if (error)
4105 goto error0;
4106 return 0;
4107 }
4108
4109 rrecs = xfs_btree_get_numrecs(right);
4110 lrecs = xfs_btree_get_numrecs(left);
4111
4112 /*
4113 * We're now going to join "left" and "right" by moving all the stuff
4114 * in "right" to "left" and deleting "right".
4115 */
4116 XFS_BTREE_STATS_ADD(cur, moves, rrecs);
4117 if (level > 0) {
4118 /* It's a non-leaf. Move keys and pointers. */
4119 union xfs_btree_key *lkp; /* left btree key */
4120 union xfs_btree_ptr *lpp; /* left address pointer */
4121 union xfs_btree_key *rkp; /* right btree key */
4122 union xfs_btree_ptr *rpp; /* right address pointer */
4123
4124 lkp = xfs_btree_key_addr(cur, lrecs + 1, left);
4125 lpp = xfs_btree_ptr_addr(cur, lrecs + 1, left);
4126 rkp = xfs_btree_key_addr(cur, 1, right);
4127 rpp = xfs_btree_ptr_addr(cur, 1, right);
4128
4129 for (i = 1; i < rrecs; i++) {
4130 error = xfs_btree_debug_check_ptr(cur, rpp, i, level);
4131 if (error)
4132 goto error0;
4133 }
4134
4135 xfs_btree_copy_keys(cur, lkp, rkp, rrecs);
4136 xfs_btree_copy_ptrs(cur, lpp, rpp, rrecs);
4137
4138 xfs_btree_log_keys(cur, lbp, lrecs + 1, lrecs + rrecs);
4139 xfs_btree_log_ptrs(cur, lbp, lrecs + 1, lrecs + rrecs);
4140 } else {
4141 /* It's a leaf. Move records. */
4142 union xfs_btree_rec *lrp; /* left record pointer */
4143 union xfs_btree_rec *rrp; /* right record pointer */
4144
4145 lrp = xfs_btree_rec_addr(cur, lrecs + 1, left);
4146 rrp = xfs_btree_rec_addr(cur, 1, right);
4147
4148 xfs_btree_copy_recs(cur, lrp, rrp, rrecs);
4149 xfs_btree_log_recs(cur, lbp, lrecs + 1, lrecs + rrecs);
4150 }
4151
4152 XFS_BTREE_STATS_INC(cur, join);
4153
4154 /*
4155 * Fix up the number of records and right block pointer in the
4156 * surviving block, and log it.
4157 */
4158 xfs_btree_set_numrecs(left, lrecs + rrecs);
4159 xfs_btree_get_sibling(cur, right, &cptr, XFS_BB_RIGHTSIB);
4160 xfs_btree_set_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
4161 xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
4162
4163 /* If there is a right sibling, point it to the remaining block. */
4164 xfs_btree_get_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
4165 if (!xfs_btree_ptr_is_null(cur, &cptr)) {
4166 error = xfs_btree_read_buf_block(cur, &cptr, 0, &rrblock, &rrbp);
4167 if (error)
4168 goto error0;
4169 xfs_btree_set_sibling(cur, rrblock, &lptr, XFS_BB_LEFTSIB);
4170 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
4171 }
4172
4173 /* Free the deleted block. */
4174 error = xfs_btree_free_block(cur, rbp);
4175 if (error)
4176 goto error0;
4177
4178 /*
4179 * If we joined with the left neighbor, set the buffer in the
4180 * cursor to the left block, and fix up the index.
4181 */
4182 if (bp != lbp) {
4183 cur->bc_levels[level].bp = lbp;
4184 cur->bc_levels[level].ptr += lrecs;
4185 cur->bc_levels[level].ra = 0;
4186 }
4187 /*
4188 * If we joined with the right neighbor and there's a level above
4189 * us, increment the cursor at that level.
4190 */
4191 else if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) ||
4192 (level + 1 < cur->bc_nlevels)) {
4193 error = xfs_btree_increment(cur, level + 1, &i);
4194 if (error)
4195 goto error0;
4196 }
4197
4198 /*
4199 * Readjust the ptr at this level if it's not a leaf, since it's
4200 * still pointing at the deletion point, which makes the cursor
4201 * inconsistent. If this makes the ptr 0, the caller fixes it up.
4202 * We can't use decrement because it would change the next level up.
4203 */
4204 if (level > 0)
4205 cur->bc_levels[level].ptr--;
4206
4207 /*
4208 * We combined blocks, so we have to update the parent keys if the
4209 * btree supports overlapped intervals. However,
4210 * bc_levels[level + 1].ptr points to the old block so that the caller
4211 * knows which record to delete. Therefore, the caller must be savvy
4212 * enough to call updkeys for us if we return stat == 2. The other
4213 * exit points from this function don't require deletions further up
4214 * the tree, so they can call updkeys directly.
4215 */
4216
4217 /* Return value means the next level up has something to do. */
4218 *stat = 2;
4219 return 0;
4220
4221 error0:
4222 if (tcur)
4223 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
4224 return error;
4225 }
4226
4227 /*
4228 * Delete the record pointed to by cur.
4229 * The cursor refers to the place where the record was (could be inserted)
4230 * when the operation returns.
4231 */
4232 int /* error */
xfs_btree_delete(struct xfs_btree_cur * cur,int * stat)4233 xfs_btree_delete(
4234 struct xfs_btree_cur *cur,
4235 int *stat) /* success/failure */
4236 {
4237 int error; /* error return value */
4238 int level;
4239 int i;
4240 bool joined = false;
4241
4242 /*
4243 * Go up the tree, starting at leaf level.
4244 *
4245 * If 2 is returned then a join was done; go to the next level.
4246 * Otherwise we are done.
4247 */
4248 for (level = 0, i = 2; i == 2; level++) {
4249 error = xfs_btree_delrec(cur, level, &i);
4250 if (error)
4251 goto error0;
4252 if (i == 2)
4253 joined = true;
4254 }
4255
4256 /*
4257 * If we combined blocks as part of deleting the record, delrec won't
4258 * have updated the parent high keys so we have to do that here.
4259 */
4260 if (joined && (cur->bc_flags & XFS_BTREE_OVERLAPPING)) {
4261 error = xfs_btree_updkeys_force(cur, 0);
4262 if (error)
4263 goto error0;
4264 }
4265
4266 if (i == 0) {
4267 for (level = 1; level < cur->bc_nlevels; level++) {
4268 if (cur->bc_levels[level].ptr == 0) {
4269 error = xfs_btree_decrement(cur, level, &i);
4270 if (error)
4271 goto error0;
4272 break;
4273 }
4274 }
4275 }
4276
4277 *stat = i;
4278 return 0;
4279 error0:
4280 return error;
4281 }
4282
4283 /*
4284 * Get the data from the pointed-to record.
4285 */
4286 int /* error */
xfs_btree_get_rec(struct xfs_btree_cur * cur,union xfs_btree_rec ** recp,int * stat)4287 xfs_btree_get_rec(
4288 struct xfs_btree_cur *cur, /* btree cursor */
4289 union xfs_btree_rec **recp, /* output: btree record */
4290 int *stat) /* output: success/failure */
4291 {
4292 struct xfs_btree_block *block; /* btree block */
4293 struct xfs_buf *bp; /* buffer pointer */
4294 int ptr; /* record number */
4295 #ifdef DEBUG
4296 int error; /* error return value */
4297 #endif
4298
4299 ptr = cur->bc_levels[0].ptr;
4300 block = xfs_btree_get_block(cur, 0, &bp);
4301
4302 #ifdef DEBUG
4303 error = xfs_btree_check_block(cur, block, 0, bp);
4304 if (error)
4305 return error;
4306 #endif
4307
4308 /*
4309 * Off the right end or left end, return failure.
4310 */
4311 if (ptr > xfs_btree_get_numrecs(block) || ptr <= 0) {
4312 *stat = 0;
4313 return 0;
4314 }
4315
4316 /*
4317 * Point to the record and extract its data.
4318 */
4319 *recp = xfs_btree_rec_addr(cur, ptr, block);
4320 *stat = 1;
4321 return 0;
4322 }
4323
4324 /* Visit a block in a btree. */
4325 STATIC int
xfs_btree_visit_block(struct xfs_btree_cur * cur,int level,xfs_btree_visit_blocks_fn fn,void * data)4326 xfs_btree_visit_block(
4327 struct xfs_btree_cur *cur,
4328 int level,
4329 xfs_btree_visit_blocks_fn fn,
4330 void *data)
4331 {
4332 struct xfs_btree_block *block;
4333 struct xfs_buf *bp;
4334 union xfs_btree_ptr rptr;
4335 int error;
4336
4337 /* do right sibling readahead */
4338 xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
4339 block = xfs_btree_get_block(cur, level, &bp);
4340
4341 /* process the block */
4342 error = fn(cur, level, data);
4343 if (error)
4344 return error;
4345
4346 /* now read rh sibling block for next iteration */
4347 xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
4348 if (xfs_btree_ptr_is_null(cur, &rptr))
4349 return -ENOENT;
4350
4351 /*
4352 * We only visit blocks once in this walk, so we have to avoid the
4353 * internal xfs_btree_lookup_get_block() optimisation where it will
4354 * return the same block without checking if the right sibling points
4355 * back to us and creates a cyclic reference in the btree.
4356 */
4357 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
4358 if (be64_to_cpu(rptr.l) == XFS_DADDR_TO_FSB(cur->bc_mp,
4359 xfs_buf_daddr(bp)))
4360 return -EFSCORRUPTED;
4361 } else {
4362 if (be32_to_cpu(rptr.s) == xfs_daddr_to_agbno(cur->bc_mp,
4363 xfs_buf_daddr(bp)))
4364 return -EFSCORRUPTED;
4365 }
4366 return xfs_btree_lookup_get_block(cur, level, &rptr, &block);
4367 }
4368
4369
4370 /* Visit every block in a btree. */
4371 int
xfs_btree_visit_blocks(struct xfs_btree_cur * cur,xfs_btree_visit_blocks_fn fn,unsigned int flags,void * data)4372 xfs_btree_visit_blocks(
4373 struct xfs_btree_cur *cur,
4374 xfs_btree_visit_blocks_fn fn,
4375 unsigned int flags,
4376 void *data)
4377 {
4378 union xfs_btree_ptr lptr;
4379 int level;
4380 struct xfs_btree_block *block = NULL;
4381 int error = 0;
4382
4383 cur->bc_ops->init_ptr_from_cur(cur, &lptr);
4384
4385 /* for each level */
4386 for (level = cur->bc_nlevels - 1; level >= 0; level--) {
4387 /* grab the left hand block */
4388 error = xfs_btree_lookup_get_block(cur, level, &lptr, &block);
4389 if (error)
4390 return error;
4391
4392 /* readahead the left most block for the next level down */
4393 if (level > 0) {
4394 union xfs_btree_ptr *ptr;
4395
4396 ptr = xfs_btree_ptr_addr(cur, 1, block);
4397 xfs_btree_readahead_ptr(cur, ptr, 1);
4398
4399 /* save for the next iteration of the loop */
4400 xfs_btree_copy_ptrs(cur, &lptr, ptr, 1);
4401
4402 if (!(flags & XFS_BTREE_VISIT_LEAVES))
4403 continue;
4404 } else if (!(flags & XFS_BTREE_VISIT_RECORDS)) {
4405 continue;
4406 }
4407
4408 /* for each buffer in the level */
4409 do {
4410 error = xfs_btree_visit_block(cur, level, fn, data);
4411 } while (!error);
4412
4413 if (error != -ENOENT)
4414 return error;
4415 }
4416
4417 return 0;
4418 }
4419
4420 /*
4421 * Change the owner of a btree.
4422 *
4423 * The mechanism we use here is ordered buffer logging. Because we don't know
4424 * how many buffers were are going to need to modify, we don't really want to
4425 * have to make transaction reservations for the worst case of every buffer in a
4426 * full size btree as that may be more space that we can fit in the log....
4427 *
4428 * We do the btree walk in the most optimal manner possible - we have sibling
4429 * pointers so we can just walk all the blocks on each level from left to right
4430 * in a single pass, and then move to the next level and do the same. We can
4431 * also do readahead on the sibling pointers to get IO moving more quickly,
4432 * though for slow disks this is unlikely to make much difference to performance
4433 * as the amount of CPU work we have to do before moving to the next block is
4434 * relatively small.
4435 *
4436 * For each btree block that we load, modify the owner appropriately, set the
4437 * buffer as an ordered buffer and log it appropriately. We need to ensure that
4438 * we mark the region we change dirty so that if the buffer is relogged in
4439 * a subsequent transaction the changes we make here as an ordered buffer are
4440 * correctly relogged in that transaction. If we are in recovery context, then
4441 * just queue the modified buffer as delayed write buffer so the transaction
4442 * recovery completion writes the changes to disk.
4443 */
4444 struct xfs_btree_block_change_owner_info {
4445 uint64_t new_owner;
4446 struct list_head *buffer_list;
4447 };
4448
4449 static int
xfs_btree_block_change_owner(struct xfs_btree_cur * cur,int level,void * data)4450 xfs_btree_block_change_owner(
4451 struct xfs_btree_cur *cur,
4452 int level,
4453 void *data)
4454 {
4455 struct xfs_btree_block_change_owner_info *bbcoi = data;
4456 struct xfs_btree_block *block;
4457 struct xfs_buf *bp;
4458
4459 /* modify the owner */
4460 block = xfs_btree_get_block(cur, level, &bp);
4461 if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
4462 if (block->bb_u.l.bb_owner == cpu_to_be64(bbcoi->new_owner))
4463 return 0;
4464 block->bb_u.l.bb_owner = cpu_to_be64(bbcoi->new_owner);
4465 } else {
4466 if (block->bb_u.s.bb_owner == cpu_to_be32(bbcoi->new_owner))
4467 return 0;
4468 block->bb_u.s.bb_owner = cpu_to_be32(bbcoi->new_owner);
4469 }
4470
4471 /*
4472 * If the block is a root block hosted in an inode, we might not have a
4473 * buffer pointer here and we shouldn't attempt to log the change as the
4474 * information is already held in the inode and discarded when the root
4475 * block is formatted into the on-disk inode fork. We still change it,
4476 * though, so everything is consistent in memory.
4477 */
4478 if (!bp) {
4479 ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
4480 ASSERT(level == cur->bc_nlevels - 1);
4481 return 0;
4482 }
4483
4484 if (cur->bc_tp) {
4485 if (!xfs_trans_ordered_buf(cur->bc_tp, bp)) {
4486 xfs_btree_log_block(cur, bp, XFS_BB_OWNER);
4487 return -EAGAIN;
4488 }
4489 } else {
4490 xfs_buf_delwri_queue(bp, bbcoi->buffer_list);
4491 }
4492
4493 return 0;
4494 }
4495
4496 int
xfs_btree_change_owner(struct xfs_btree_cur * cur,uint64_t new_owner,struct list_head * buffer_list)4497 xfs_btree_change_owner(
4498 struct xfs_btree_cur *cur,
4499 uint64_t new_owner,
4500 struct list_head *buffer_list)
4501 {
4502 struct xfs_btree_block_change_owner_info bbcoi;
4503
4504 bbcoi.new_owner = new_owner;
4505 bbcoi.buffer_list = buffer_list;
4506
4507 return xfs_btree_visit_blocks(cur, xfs_btree_block_change_owner,
4508 XFS_BTREE_VISIT_ALL, &bbcoi);
4509 }
4510
4511 /* Verify the v5 fields of a long-format btree block. */
4512 xfs_failaddr_t
xfs_btree_lblock_v5hdr_verify(struct xfs_buf * bp,uint64_t owner)4513 xfs_btree_lblock_v5hdr_verify(
4514 struct xfs_buf *bp,
4515 uint64_t owner)
4516 {
4517 struct xfs_mount *mp = bp->b_mount;
4518 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
4519
4520 if (!xfs_has_crc(mp))
4521 return __this_address;
4522 if (!uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid))
4523 return __this_address;
4524 if (block->bb_u.l.bb_blkno != cpu_to_be64(xfs_buf_daddr(bp)))
4525 return __this_address;
4526 if (owner != XFS_RMAP_OWN_UNKNOWN &&
4527 be64_to_cpu(block->bb_u.l.bb_owner) != owner)
4528 return __this_address;
4529 return NULL;
4530 }
4531
4532 /* Verify a long-format btree block. */
4533 xfs_failaddr_t
xfs_btree_lblock_verify(struct xfs_buf * bp,unsigned int max_recs)4534 xfs_btree_lblock_verify(
4535 struct xfs_buf *bp,
4536 unsigned int max_recs)
4537 {
4538 struct xfs_mount *mp = bp->b_mount;
4539 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
4540 xfs_fsblock_t fsb;
4541 xfs_failaddr_t fa;
4542
4543 /* numrecs verification */
4544 if (be16_to_cpu(block->bb_numrecs) > max_recs)
4545 return __this_address;
4546
4547 /* sibling pointer verification */
4548 fsb = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp));
4549 fa = xfs_btree_check_lblock_siblings(mp, NULL, -1, fsb,
4550 block->bb_u.l.bb_leftsib);
4551 if (!fa)
4552 fa = xfs_btree_check_lblock_siblings(mp, NULL, -1, fsb,
4553 block->bb_u.l.bb_rightsib);
4554 return fa;
4555 }
4556
4557 /**
4558 * xfs_btree_sblock_v5hdr_verify() -- verify the v5 fields of a short-format
4559 * btree block
4560 *
4561 * @bp: buffer containing the btree block
4562 */
4563 xfs_failaddr_t
xfs_btree_sblock_v5hdr_verify(struct xfs_buf * bp)4564 xfs_btree_sblock_v5hdr_verify(
4565 struct xfs_buf *bp)
4566 {
4567 struct xfs_mount *mp = bp->b_mount;
4568 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
4569 struct xfs_perag *pag = bp->b_pag;
4570
4571 if (!xfs_has_crc(mp))
4572 return __this_address;
4573 if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid))
4574 return __this_address;
4575 if (block->bb_u.s.bb_blkno != cpu_to_be64(xfs_buf_daddr(bp)))
4576 return __this_address;
4577 if (pag && be32_to_cpu(block->bb_u.s.bb_owner) != pag->pag_agno)
4578 return __this_address;
4579 return NULL;
4580 }
4581
4582 /**
4583 * xfs_btree_sblock_verify() -- verify a short-format btree block
4584 *
4585 * @bp: buffer containing the btree block
4586 * @max_recs: maximum records allowed in this btree node
4587 */
4588 xfs_failaddr_t
xfs_btree_sblock_verify(struct xfs_buf * bp,unsigned int max_recs)4589 xfs_btree_sblock_verify(
4590 struct xfs_buf *bp,
4591 unsigned int max_recs)
4592 {
4593 struct xfs_mount *mp = bp->b_mount;
4594 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
4595 xfs_agblock_t agbno;
4596 xfs_failaddr_t fa;
4597
4598 /* numrecs verification */
4599 if (be16_to_cpu(block->bb_numrecs) > max_recs)
4600 return __this_address;
4601
4602 /* sibling pointer verification */
4603 agbno = xfs_daddr_to_agbno(mp, xfs_buf_daddr(bp));
4604 fa = xfs_btree_check_sblock_siblings(bp->b_pag, NULL, -1, agbno,
4605 block->bb_u.s.bb_leftsib);
4606 if (!fa)
4607 fa = xfs_btree_check_sblock_siblings(bp->b_pag, NULL, -1, agbno,
4608 block->bb_u.s.bb_rightsib);
4609 return fa;
4610 }
4611
4612 /*
4613 * For the given limits on leaf and keyptr records per block, calculate the
4614 * height of the tree needed to index the number of leaf records.
4615 */
4616 unsigned int
xfs_btree_compute_maxlevels(const unsigned int * limits,unsigned long long records)4617 xfs_btree_compute_maxlevels(
4618 const unsigned int *limits,
4619 unsigned long long records)
4620 {
4621 unsigned long long level_blocks = howmany_64(records, limits[0]);
4622 unsigned int height = 1;
4623
4624 while (level_blocks > 1) {
4625 level_blocks = howmany_64(level_blocks, limits[1]);
4626 height++;
4627 }
4628
4629 return height;
4630 }
4631
4632 /*
4633 * For the given limits on leaf and keyptr records per block, calculate the
4634 * number of blocks needed to index the given number of leaf records.
4635 */
4636 unsigned long long
xfs_btree_calc_size(const unsigned int * limits,unsigned long long records)4637 xfs_btree_calc_size(
4638 const unsigned int *limits,
4639 unsigned long long records)
4640 {
4641 unsigned long long level_blocks = howmany_64(records, limits[0]);
4642 unsigned long long blocks = level_blocks;
4643
4644 while (level_blocks > 1) {
4645 level_blocks = howmany_64(level_blocks, limits[1]);
4646 blocks += level_blocks;
4647 }
4648
4649 return blocks;
4650 }
4651
4652 /*
4653 * Given a number of available blocks for the btree to consume with records and
4654 * pointers, calculate the height of the tree needed to index all the records
4655 * that space can hold based on the number of pointers each interior node
4656 * holds.
4657 *
4658 * We start by assuming a single level tree consumes a single block, then track
4659 * the number of blocks each node level consumes until we no longer have space
4660 * to store the next node level. At this point, we are indexing all the leaf
4661 * blocks in the space, and there's no more free space to split the tree any
4662 * further. That's our maximum btree height.
4663 */
4664 unsigned int
xfs_btree_space_to_height(const unsigned int * limits,unsigned long long leaf_blocks)4665 xfs_btree_space_to_height(
4666 const unsigned int *limits,
4667 unsigned long long leaf_blocks)
4668 {
4669 unsigned long long node_blocks = limits[1];
4670 unsigned long long blocks_left = leaf_blocks - 1;
4671 unsigned int height = 1;
4672
4673 if (leaf_blocks < 1)
4674 return 0;
4675
4676 while (node_blocks < blocks_left) {
4677 blocks_left -= node_blocks;
4678 node_blocks *= limits[1];
4679 height++;
4680 }
4681
4682 return height;
4683 }
4684
4685 /*
4686 * Query a regular btree for all records overlapping a given interval.
4687 * Start with a LE lookup of the key of low_rec and return all records
4688 * until we find a record with a key greater than the key of high_rec.
4689 */
4690 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)4691 xfs_btree_simple_query_range(
4692 struct xfs_btree_cur *cur,
4693 const union xfs_btree_key *low_key,
4694 const union xfs_btree_key *high_key,
4695 xfs_btree_query_range_fn fn,
4696 void *priv)
4697 {
4698 union xfs_btree_rec *recp;
4699 union xfs_btree_key rec_key;
4700 int64_t diff;
4701 int stat;
4702 bool firstrec = true;
4703 int error;
4704
4705 ASSERT(cur->bc_ops->init_high_key_from_rec);
4706 ASSERT(cur->bc_ops->diff_two_keys);
4707
4708 /*
4709 * Find the leftmost record. The btree cursor must be set
4710 * to the low record used to generate low_key.
4711 */
4712 stat = 0;
4713 error = xfs_btree_lookup(cur, XFS_LOOKUP_LE, &stat);
4714 if (error)
4715 goto out;
4716
4717 /* Nothing? See if there's anything to the right. */
4718 if (!stat) {
4719 error = xfs_btree_increment(cur, 0, &stat);
4720 if (error)
4721 goto out;
4722 }
4723
4724 while (stat) {
4725 /* Find the record. */
4726 error = xfs_btree_get_rec(cur, &recp, &stat);
4727 if (error || !stat)
4728 break;
4729
4730 /* Skip if high_key(rec) < low_key. */
4731 if (firstrec) {
4732 cur->bc_ops->init_high_key_from_rec(&rec_key, recp);
4733 firstrec = false;
4734 diff = cur->bc_ops->diff_two_keys(cur, low_key,
4735 &rec_key);
4736 if (diff > 0)
4737 goto advloop;
4738 }
4739
4740 /* Stop if high_key < low_key(rec). */
4741 cur->bc_ops->init_key_from_rec(&rec_key, recp);
4742 diff = cur->bc_ops->diff_two_keys(cur, &rec_key, high_key);
4743 if (diff > 0)
4744 break;
4745
4746 /* Callback */
4747 error = fn(cur, recp, priv);
4748 if (error)
4749 break;
4750
4751 advloop:
4752 /* Move on to the next record. */
4753 error = xfs_btree_increment(cur, 0, &stat);
4754 if (error)
4755 break;
4756 }
4757
4758 out:
4759 return error;
4760 }
4761
4762 /*
4763 * Query an overlapped interval btree for all records overlapping a given
4764 * interval. This function roughly follows the algorithm given in
4765 * "Interval Trees" of _Introduction to Algorithms_, which is section
4766 * 14.3 in the 2nd and 3rd editions.
4767 *
4768 * First, generate keys for the low and high records passed in.
4769 *
4770 * For any leaf node, generate the high and low keys for the record.
4771 * If the record keys overlap with the query low/high keys, pass the
4772 * record to the function iterator.
4773 *
4774 * For any internal node, compare the low and high keys of each
4775 * pointer against the query low/high keys. If there's an overlap,
4776 * follow the pointer.
4777 *
4778 * As an optimization, we stop scanning a block when we find a low key
4779 * that is greater than the query's high key.
4780 */
4781 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)4782 xfs_btree_overlapped_query_range(
4783 struct xfs_btree_cur *cur,
4784 const union xfs_btree_key *low_key,
4785 const union xfs_btree_key *high_key,
4786 xfs_btree_query_range_fn fn,
4787 void *priv)
4788 {
4789 union xfs_btree_ptr ptr;
4790 union xfs_btree_ptr *pp;
4791 union xfs_btree_key rec_key;
4792 union xfs_btree_key rec_hkey;
4793 union xfs_btree_key *lkp;
4794 union xfs_btree_key *hkp;
4795 union xfs_btree_rec *recp;
4796 struct xfs_btree_block *block;
4797 int64_t ldiff;
4798 int64_t hdiff;
4799 int level;
4800 struct xfs_buf *bp;
4801 int i;
4802 int error;
4803
4804 /* Load the root of the btree. */
4805 level = cur->bc_nlevels - 1;
4806 cur->bc_ops->init_ptr_from_cur(cur, &ptr);
4807 error = xfs_btree_lookup_get_block(cur, level, &ptr, &block);
4808 if (error)
4809 return error;
4810 xfs_btree_get_block(cur, level, &bp);
4811 trace_xfs_btree_overlapped_query_range(cur, level, bp);
4812 #ifdef DEBUG
4813 error = xfs_btree_check_block(cur, block, level, bp);
4814 if (error)
4815 goto out;
4816 #endif
4817 cur->bc_levels[level].ptr = 1;
4818
4819 while (level < cur->bc_nlevels) {
4820 block = xfs_btree_get_block(cur, level, &bp);
4821
4822 /* End of node, pop back towards the root. */
4823 if (cur->bc_levels[level].ptr >
4824 be16_to_cpu(block->bb_numrecs)) {
4825 pop_up:
4826 if (level < cur->bc_nlevels - 1)
4827 cur->bc_levels[level + 1].ptr++;
4828 level++;
4829 continue;
4830 }
4831
4832 if (level == 0) {
4833 /* Handle a leaf node. */
4834 recp = xfs_btree_rec_addr(cur, cur->bc_levels[0].ptr,
4835 block);
4836
4837 cur->bc_ops->init_high_key_from_rec(&rec_hkey, recp);
4838 ldiff = cur->bc_ops->diff_two_keys(cur, &rec_hkey,
4839 low_key);
4840
4841 cur->bc_ops->init_key_from_rec(&rec_key, recp);
4842 hdiff = cur->bc_ops->diff_two_keys(cur, high_key,
4843 &rec_key);
4844
4845 /*
4846 * If (record's high key >= query's low key) and
4847 * (query's high key >= record's low key), then
4848 * this record overlaps the query range; callback.
4849 */
4850 if (ldiff >= 0 && hdiff >= 0) {
4851 error = fn(cur, recp, priv);
4852 if (error)
4853 break;
4854 } else if (hdiff < 0) {
4855 /* Record is larger than high key; pop. */
4856 goto pop_up;
4857 }
4858 cur->bc_levels[level].ptr++;
4859 continue;
4860 }
4861
4862 /* Handle an internal node. */
4863 lkp = xfs_btree_key_addr(cur, cur->bc_levels[level].ptr, block);
4864 hkp = xfs_btree_high_key_addr(cur, cur->bc_levels[level].ptr,
4865 block);
4866 pp = xfs_btree_ptr_addr(cur, cur->bc_levels[level].ptr, block);
4867
4868 ldiff = cur->bc_ops->diff_two_keys(cur, hkp, low_key);
4869 hdiff = cur->bc_ops->diff_two_keys(cur, high_key, lkp);
4870
4871 /*
4872 * If (pointer's high key >= query's low key) and
4873 * (query's high key >= pointer's low key), then
4874 * this record overlaps the query range; follow pointer.
4875 */
4876 if (ldiff >= 0 && hdiff >= 0) {
4877 level--;
4878 error = xfs_btree_lookup_get_block(cur, level, pp,
4879 &block);
4880 if (error)
4881 goto out;
4882 xfs_btree_get_block(cur, level, &bp);
4883 trace_xfs_btree_overlapped_query_range(cur, level, bp);
4884 #ifdef DEBUG
4885 error = xfs_btree_check_block(cur, block, level, bp);
4886 if (error)
4887 goto out;
4888 #endif
4889 cur->bc_levels[level].ptr = 1;
4890 continue;
4891 } else if (hdiff < 0) {
4892 /* The low key is larger than the upper range; pop. */
4893 goto pop_up;
4894 }
4895 cur->bc_levels[level].ptr++;
4896 }
4897
4898 out:
4899 /*
4900 * If we don't end this function with the cursor pointing at a record
4901 * block, a subsequent non-error cursor deletion will not release
4902 * node-level buffers, causing a buffer leak. This is quite possible
4903 * with a zero-results range query, so release the buffers if we
4904 * failed to return any results.
4905 */
4906 if (cur->bc_levels[0].bp == NULL) {
4907 for (i = 0; i < cur->bc_nlevels; i++) {
4908 if (cur->bc_levels[i].bp) {
4909 xfs_trans_brelse(cur->bc_tp,
4910 cur->bc_levels[i].bp);
4911 cur->bc_levels[i].bp = NULL;
4912 cur->bc_levels[i].ptr = 0;
4913 cur->bc_levels[i].ra = 0;
4914 }
4915 }
4916 }
4917
4918 return error;
4919 }
4920
4921 /*
4922 * Query a btree for all records overlapping a given interval of keys. The
4923 * supplied function will be called with each record found; return one of the
4924 * XFS_BTREE_QUERY_RANGE_{CONTINUE,ABORT} values or the usual negative error
4925 * code. This function returns -ECANCELED, zero, or a negative error code.
4926 */
4927 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)4928 xfs_btree_query_range(
4929 struct xfs_btree_cur *cur,
4930 const union xfs_btree_irec *low_rec,
4931 const union xfs_btree_irec *high_rec,
4932 xfs_btree_query_range_fn fn,
4933 void *priv)
4934 {
4935 union xfs_btree_rec rec;
4936 union xfs_btree_key low_key;
4937 union xfs_btree_key high_key;
4938
4939 /* Find the keys of both ends of the interval. */
4940 cur->bc_rec = *high_rec;
4941 cur->bc_ops->init_rec_from_cur(cur, &rec);
4942 cur->bc_ops->init_key_from_rec(&high_key, &rec);
4943
4944 cur->bc_rec = *low_rec;
4945 cur->bc_ops->init_rec_from_cur(cur, &rec);
4946 cur->bc_ops->init_key_from_rec(&low_key, &rec);
4947
4948 /* Enforce low key < high key. */
4949 if (cur->bc_ops->diff_two_keys(cur, &low_key, &high_key) > 0)
4950 return -EINVAL;
4951
4952 if (!(cur->bc_flags & XFS_BTREE_OVERLAPPING))
4953 return xfs_btree_simple_query_range(cur, &low_key,
4954 &high_key, fn, priv);
4955 return xfs_btree_overlapped_query_range(cur, &low_key, &high_key,
4956 fn, priv);
4957 }
4958
4959 /* Query a btree for all records. */
4960 int
xfs_btree_query_all(struct xfs_btree_cur * cur,xfs_btree_query_range_fn fn,void * priv)4961 xfs_btree_query_all(
4962 struct xfs_btree_cur *cur,
4963 xfs_btree_query_range_fn fn,
4964 void *priv)
4965 {
4966 union xfs_btree_key low_key;
4967 union xfs_btree_key high_key;
4968
4969 memset(&cur->bc_rec, 0, sizeof(cur->bc_rec));
4970 memset(&low_key, 0, sizeof(low_key));
4971 memset(&high_key, 0xFF, sizeof(high_key));
4972
4973 return xfs_btree_simple_query_range(cur, &low_key, &high_key, fn, priv);
4974 }
4975
4976 static int
xfs_btree_count_blocks_helper(struct xfs_btree_cur * cur,int level,void * data)4977 xfs_btree_count_blocks_helper(
4978 struct xfs_btree_cur *cur,
4979 int level,
4980 void *data)
4981 {
4982 xfs_extlen_t *blocks = data;
4983 (*blocks)++;
4984
4985 return 0;
4986 }
4987
4988 /* Count the blocks in a btree and return the result in *blocks. */
4989 int
xfs_btree_count_blocks(struct xfs_btree_cur * cur,xfs_extlen_t * blocks)4990 xfs_btree_count_blocks(
4991 struct xfs_btree_cur *cur,
4992 xfs_extlen_t *blocks)
4993 {
4994 *blocks = 0;
4995 return xfs_btree_visit_blocks(cur, xfs_btree_count_blocks_helper,
4996 XFS_BTREE_VISIT_ALL, blocks);
4997 }
4998
4999 /* Compare two btree pointers. */
5000 int64_t
xfs_btree_diff_two_ptrs(struct xfs_btree_cur * cur,const union xfs_btree_ptr * a,const union xfs_btree_ptr * b)5001 xfs_btree_diff_two_ptrs(
5002 struct xfs_btree_cur *cur,
5003 const union xfs_btree_ptr *a,
5004 const union xfs_btree_ptr *b)
5005 {
5006 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
5007 return (int64_t)be64_to_cpu(a->l) - be64_to_cpu(b->l);
5008 return (int64_t)be32_to_cpu(a->s) - be32_to_cpu(b->s);
5009 }
5010
5011 /* If there's an extent, we're done. */
5012 STATIC int
xfs_btree_has_record_helper(struct xfs_btree_cur * cur,const union xfs_btree_rec * rec,void * priv)5013 xfs_btree_has_record_helper(
5014 struct xfs_btree_cur *cur,
5015 const union xfs_btree_rec *rec,
5016 void *priv)
5017 {
5018 return -ECANCELED;
5019 }
5020
5021 /* Is there a record covering a given range of keys? */
5022 int
xfs_btree_has_record(struct xfs_btree_cur * cur,const union xfs_btree_irec * low,const union xfs_btree_irec * high,bool * exists)5023 xfs_btree_has_record(
5024 struct xfs_btree_cur *cur,
5025 const union xfs_btree_irec *low,
5026 const union xfs_btree_irec *high,
5027 bool *exists)
5028 {
5029 int error;
5030
5031 error = xfs_btree_query_range(cur, low, high,
5032 &xfs_btree_has_record_helper, NULL);
5033 if (error == -ECANCELED) {
5034 *exists = true;
5035 return 0;
5036 }
5037 *exists = false;
5038 return error;
5039 }
5040
5041 /* Are there more records in this btree? */
5042 bool
xfs_btree_has_more_records(struct xfs_btree_cur * cur)5043 xfs_btree_has_more_records(
5044 struct xfs_btree_cur *cur)
5045 {
5046 struct xfs_btree_block *block;
5047 struct xfs_buf *bp;
5048
5049 block = xfs_btree_get_block(cur, 0, &bp);
5050
5051 /* There are still records in this block. */
5052 if (cur->bc_levels[0].ptr < xfs_btree_get_numrecs(block))
5053 return true;
5054
5055 /* There are more record blocks. */
5056 if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
5057 return block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK);
5058 else
5059 return block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK);
5060 }
5061
5062 /* Set up all the btree cursor caches. */
5063 int __init
xfs_btree_init_cur_caches(void)5064 xfs_btree_init_cur_caches(void)
5065 {
5066 int error;
5067
5068 error = xfs_allocbt_init_cur_cache();
5069 if (error)
5070 return error;
5071 error = xfs_inobt_init_cur_cache();
5072 if (error)
5073 goto err;
5074 error = xfs_bmbt_init_cur_cache();
5075 if (error)
5076 goto err;
5077 error = xfs_rmapbt_init_cur_cache();
5078 if (error)
5079 goto err;
5080 error = xfs_refcountbt_init_cur_cache();
5081 if (error)
5082 goto err;
5083
5084 return 0;
5085 err:
5086 xfs_btree_destroy_cur_caches();
5087 return error;
5088 }
5089
5090 /* Destroy all the btree cursor caches, if they've been allocated. */
5091 void
xfs_btree_destroy_cur_caches(void)5092 xfs_btree_destroy_cur_caches(void)
5093 {
5094 xfs_allocbt_destroy_cur_cache();
5095 xfs_inobt_destroy_cur_cache();
5096 xfs_bmbt_destroy_cur_cache();
5097 xfs_rmapbt_destroy_cur_cache();
5098 xfs_refcountbt_destroy_cur_cache();
5099 }
5100