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[mirror_ubuntu-hirsute-kernel.git] / fs / nilfs2 / btree.c
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * btree.c - NILFS B-tree.
4 *
5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
6 *
7 * Written by Koji Sato.
8 */
9
10 #include <linux/slab.h>
11 #include <linux/string.h>
12 #include <linux/errno.h>
13 #include <linux/pagevec.h>
14 #include "nilfs.h"
15 #include "page.h"
16 #include "btnode.h"
17 #include "btree.h"
18 #include "alloc.h"
19 #include "dat.h"
20
21 static void __nilfs_btree_init(struct nilfs_bmap *bmap);
22
23 static struct nilfs_btree_path *nilfs_btree_alloc_path(void)
24 {
25 struct nilfs_btree_path *path;
26 int level = NILFS_BTREE_LEVEL_DATA;
27
28 path = kmem_cache_alloc(nilfs_btree_path_cache, GFP_NOFS);
29 if (path == NULL)
30 goto out;
31
32 for (; level < NILFS_BTREE_LEVEL_MAX; level++) {
33 path[level].bp_bh = NULL;
34 path[level].bp_sib_bh = NULL;
35 path[level].bp_index = 0;
36 path[level].bp_oldreq.bpr_ptr = NILFS_BMAP_INVALID_PTR;
37 path[level].bp_newreq.bpr_ptr = NILFS_BMAP_INVALID_PTR;
38 path[level].bp_op = NULL;
39 }
40
41 out:
42 return path;
43 }
44
45 static void nilfs_btree_free_path(struct nilfs_btree_path *path)
46 {
47 int level = NILFS_BTREE_LEVEL_DATA;
48
49 for (; level < NILFS_BTREE_LEVEL_MAX; level++)
50 brelse(path[level].bp_bh);
51
52 kmem_cache_free(nilfs_btree_path_cache, path);
53 }
54
55 /*
56 * B-tree node operations
57 */
58 static int nilfs_btree_get_new_block(const struct nilfs_bmap *btree,
59 __u64 ptr, struct buffer_head **bhp)
60 {
61 struct address_space *btnc = &NILFS_BMAP_I(btree)->i_btnode_cache;
62 struct buffer_head *bh;
63
64 bh = nilfs_btnode_create_block(btnc, ptr);
65 if (!bh)
66 return -ENOMEM;
67
68 set_buffer_nilfs_volatile(bh);
69 *bhp = bh;
70 return 0;
71 }
72
73 static int nilfs_btree_node_get_flags(const struct nilfs_btree_node *node)
74 {
75 return node->bn_flags;
76 }
77
78 static void
79 nilfs_btree_node_set_flags(struct nilfs_btree_node *node, int flags)
80 {
81 node->bn_flags = flags;
82 }
83
84 static int nilfs_btree_node_root(const struct nilfs_btree_node *node)
85 {
86 return nilfs_btree_node_get_flags(node) & NILFS_BTREE_NODE_ROOT;
87 }
88
89 static int nilfs_btree_node_get_level(const struct nilfs_btree_node *node)
90 {
91 return node->bn_level;
92 }
93
94 static void
95 nilfs_btree_node_set_level(struct nilfs_btree_node *node, int level)
96 {
97 node->bn_level = level;
98 }
99
100 static int nilfs_btree_node_get_nchildren(const struct nilfs_btree_node *node)
101 {
102 return le16_to_cpu(node->bn_nchildren);
103 }
104
105 static void
106 nilfs_btree_node_set_nchildren(struct nilfs_btree_node *node, int nchildren)
107 {
108 node->bn_nchildren = cpu_to_le16(nchildren);
109 }
110
111 static int nilfs_btree_node_size(const struct nilfs_bmap *btree)
112 {
113 return i_blocksize(btree->b_inode);
114 }
115
116 static int nilfs_btree_nchildren_per_block(const struct nilfs_bmap *btree)
117 {
118 return btree->b_nchildren_per_block;
119 }
120
121 static __le64 *
122 nilfs_btree_node_dkeys(const struct nilfs_btree_node *node)
123 {
124 return (__le64 *)((char *)(node + 1) +
125 (nilfs_btree_node_root(node) ?
126 0 : NILFS_BTREE_NODE_EXTRA_PAD_SIZE));
127 }
128
129 static __le64 *
130 nilfs_btree_node_dptrs(const struct nilfs_btree_node *node, int ncmax)
131 {
132 return (__le64 *)(nilfs_btree_node_dkeys(node) + ncmax);
133 }
134
135 static __u64
136 nilfs_btree_node_get_key(const struct nilfs_btree_node *node, int index)
137 {
138 return le64_to_cpu(*(nilfs_btree_node_dkeys(node) + index));
139 }
140
141 static void
142 nilfs_btree_node_set_key(struct nilfs_btree_node *node, int index, __u64 key)
143 {
144 *(nilfs_btree_node_dkeys(node) + index) = cpu_to_le64(key);
145 }
146
147 static __u64
148 nilfs_btree_node_get_ptr(const struct nilfs_btree_node *node, int index,
149 int ncmax)
150 {
151 return le64_to_cpu(*(nilfs_btree_node_dptrs(node, ncmax) + index));
152 }
153
154 static void
155 nilfs_btree_node_set_ptr(struct nilfs_btree_node *node, int index, __u64 ptr,
156 int ncmax)
157 {
158 *(nilfs_btree_node_dptrs(node, ncmax) + index) = cpu_to_le64(ptr);
159 }
160
161 static void nilfs_btree_node_init(struct nilfs_btree_node *node, int flags,
162 int level, int nchildren, int ncmax,
163 const __u64 *keys, const __u64 *ptrs)
164 {
165 __le64 *dkeys;
166 __le64 *dptrs;
167 int i;
168
169 nilfs_btree_node_set_flags(node, flags);
170 nilfs_btree_node_set_level(node, level);
171 nilfs_btree_node_set_nchildren(node, nchildren);
172
173 dkeys = nilfs_btree_node_dkeys(node);
174 dptrs = nilfs_btree_node_dptrs(node, ncmax);
175 for (i = 0; i < nchildren; i++) {
176 dkeys[i] = cpu_to_le64(keys[i]);
177 dptrs[i] = cpu_to_le64(ptrs[i]);
178 }
179 }
180
181 /* Assume the buffer heads corresponding to left and right are locked. */
182 static void nilfs_btree_node_move_left(struct nilfs_btree_node *left,
183 struct nilfs_btree_node *right,
184 int n, int lncmax, int rncmax)
185 {
186 __le64 *ldkeys, *rdkeys;
187 __le64 *ldptrs, *rdptrs;
188 int lnchildren, rnchildren;
189
190 ldkeys = nilfs_btree_node_dkeys(left);
191 ldptrs = nilfs_btree_node_dptrs(left, lncmax);
192 lnchildren = nilfs_btree_node_get_nchildren(left);
193
194 rdkeys = nilfs_btree_node_dkeys(right);
195 rdptrs = nilfs_btree_node_dptrs(right, rncmax);
196 rnchildren = nilfs_btree_node_get_nchildren(right);
197
198 memcpy(ldkeys + lnchildren, rdkeys, n * sizeof(*rdkeys));
199 memcpy(ldptrs + lnchildren, rdptrs, n * sizeof(*rdptrs));
200 memmove(rdkeys, rdkeys + n, (rnchildren - n) * sizeof(*rdkeys));
201 memmove(rdptrs, rdptrs + n, (rnchildren - n) * sizeof(*rdptrs));
202
203 lnchildren += n;
204 rnchildren -= n;
205 nilfs_btree_node_set_nchildren(left, lnchildren);
206 nilfs_btree_node_set_nchildren(right, rnchildren);
207 }
208
209 /* Assume that the buffer heads corresponding to left and right are locked. */
210 static void nilfs_btree_node_move_right(struct nilfs_btree_node *left,
211 struct nilfs_btree_node *right,
212 int n, int lncmax, int rncmax)
213 {
214 __le64 *ldkeys, *rdkeys;
215 __le64 *ldptrs, *rdptrs;
216 int lnchildren, rnchildren;
217
218 ldkeys = nilfs_btree_node_dkeys(left);
219 ldptrs = nilfs_btree_node_dptrs(left, lncmax);
220 lnchildren = nilfs_btree_node_get_nchildren(left);
221
222 rdkeys = nilfs_btree_node_dkeys(right);
223 rdptrs = nilfs_btree_node_dptrs(right, rncmax);
224 rnchildren = nilfs_btree_node_get_nchildren(right);
225
226 memmove(rdkeys + n, rdkeys, rnchildren * sizeof(*rdkeys));
227 memmove(rdptrs + n, rdptrs, rnchildren * sizeof(*rdptrs));
228 memcpy(rdkeys, ldkeys + lnchildren - n, n * sizeof(*rdkeys));
229 memcpy(rdptrs, ldptrs + lnchildren - n, n * sizeof(*rdptrs));
230
231 lnchildren -= n;
232 rnchildren += n;
233 nilfs_btree_node_set_nchildren(left, lnchildren);
234 nilfs_btree_node_set_nchildren(right, rnchildren);
235 }
236
237 /* Assume that the buffer head corresponding to node is locked. */
238 static void nilfs_btree_node_insert(struct nilfs_btree_node *node, int index,
239 __u64 key, __u64 ptr, int ncmax)
240 {
241 __le64 *dkeys;
242 __le64 *dptrs;
243 int nchildren;
244
245 dkeys = nilfs_btree_node_dkeys(node);
246 dptrs = nilfs_btree_node_dptrs(node, ncmax);
247 nchildren = nilfs_btree_node_get_nchildren(node);
248 if (index < nchildren) {
249 memmove(dkeys + index + 1, dkeys + index,
250 (nchildren - index) * sizeof(*dkeys));
251 memmove(dptrs + index + 1, dptrs + index,
252 (nchildren - index) * sizeof(*dptrs));
253 }
254 dkeys[index] = cpu_to_le64(key);
255 dptrs[index] = cpu_to_le64(ptr);
256 nchildren++;
257 nilfs_btree_node_set_nchildren(node, nchildren);
258 }
259
260 /* Assume that the buffer head corresponding to node is locked. */
261 static void nilfs_btree_node_delete(struct nilfs_btree_node *node, int index,
262 __u64 *keyp, __u64 *ptrp, int ncmax)
263 {
264 __u64 key;
265 __u64 ptr;
266 __le64 *dkeys;
267 __le64 *dptrs;
268 int nchildren;
269
270 dkeys = nilfs_btree_node_dkeys(node);
271 dptrs = nilfs_btree_node_dptrs(node, ncmax);
272 key = le64_to_cpu(dkeys[index]);
273 ptr = le64_to_cpu(dptrs[index]);
274 nchildren = nilfs_btree_node_get_nchildren(node);
275 if (keyp != NULL)
276 *keyp = key;
277 if (ptrp != NULL)
278 *ptrp = ptr;
279
280 if (index < nchildren - 1) {
281 memmove(dkeys + index, dkeys + index + 1,
282 (nchildren - index - 1) * sizeof(*dkeys));
283 memmove(dptrs + index, dptrs + index + 1,
284 (nchildren - index - 1) * sizeof(*dptrs));
285 }
286 nchildren--;
287 nilfs_btree_node_set_nchildren(node, nchildren);
288 }
289
290 static int nilfs_btree_node_lookup(const struct nilfs_btree_node *node,
291 __u64 key, int *indexp)
292 {
293 __u64 nkey;
294 int index, low, high, s;
295
296 /* binary search */
297 low = 0;
298 high = nilfs_btree_node_get_nchildren(node) - 1;
299 index = 0;
300 s = 0;
301 while (low <= high) {
302 index = (low + high) / 2;
303 nkey = nilfs_btree_node_get_key(node, index);
304 if (nkey == key) {
305 s = 0;
306 goto out;
307 } else if (nkey < key) {
308 low = index + 1;
309 s = -1;
310 } else {
311 high = index - 1;
312 s = 1;
313 }
314 }
315
316 /* adjust index */
317 if (nilfs_btree_node_get_level(node) > NILFS_BTREE_LEVEL_NODE_MIN) {
318 if (s > 0 && index > 0)
319 index--;
320 } else if (s < 0)
321 index++;
322
323 out:
324 *indexp = index;
325
326 return s == 0;
327 }
328
329 /**
330 * nilfs_btree_node_broken - verify consistency of btree node
331 * @node: btree node block to be examined
332 * @size: node size (in bytes)
333 * @inode: host inode of btree
334 * @blocknr: block number
335 *
336 * Return Value: If node is broken, 1 is returned. Otherwise, 0 is returned.
337 */
338 static int nilfs_btree_node_broken(const struct nilfs_btree_node *node,
339 size_t size, struct inode *inode,
340 sector_t blocknr)
341 {
342 int level, flags, nchildren;
343 int ret = 0;
344
345 level = nilfs_btree_node_get_level(node);
346 flags = nilfs_btree_node_get_flags(node);
347 nchildren = nilfs_btree_node_get_nchildren(node);
348
349 if (unlikely(level < NILFS_BTREE_LEVEL_NODE_MIN ||
350 level >= NILFS_BTREE_LEVEL_MAX ||
351 (flags & NILFS_BTREE_NODE_ROOT) ||
352 nchildren < 0 ||
353 nchildren > NILFS_BTREE_NODE_NCHILDREN_MAX(size))) {
354 nilfs_crit(inode->i_sb,
355 "bad btree node (ino=%lu, blocknr=%llu): level = %d, flags = 0x%x, nchildren = %d",
356 inode->i_ino, (unsigned long long)blocknr, level,
357 flags, nchildren);
358 ret = 1;
359 }
360 return ret;
361 }
362
363 /**
364 * nilfs_btree_root_broken - verify consistency of btree root node
365 * @node: btree root node to be examined
366 * @inode: host inode of btree
367 *
368 * Return Value: If node is broken, 1 is returned. Otherwise, 0 is returned.
369 */
370 static int nilfs_btree_root_broken(const struct nilfs_btree_node *node,
371 struct inode *inode)
372 {
373 int level, flags, nchildren;
374 int ret = 0;
375
376 level = nilfs_btree_node_get_level(node);
377 flags = nilfs_btree_node_get_flags(node);
378 nchildren = nilfs_btree_node_get_nchildren(node);
379
380 if (unlikely(level < NILFS_BTREE_LEVEL_NODE_MIN ||
381 level >= NILFS_BTREE_LEVEL_MAX ||
382 nchildren < 0 ||
383 nchildren > NILFS_BTREE_ROOT_NCHILDREN_MAX)) {
384 nilfs_crit(inode->i_sb,
385 "bad btree root (ino=%lu): level = %d, flags = 0x%x, nchildren = %d",
386 inode->i_ino, level, flags, nchildren);
387 ret = 1;
388 }
389 return ret;
390 }
391
392 int nilfs_btree_broken_node_block(struct buffer_head *bh)
393 {
394 struct inode *inode;
395 int ret;
396
397 if (buffer_nilfs_checked(bh))
398 return 0;
399
400 inode = bh->b_page->mapping->host;
401 ret = nilfs_btree_node_broken((struct nilfs_btree_node *)bh->b_data,
402 bh->b_size, inode, bh->b_blocknr);
403 if (likely(!ret))
404 set_buffer_nilfs_checked(bh);
405 return ret;
406 }
407
408 static struct nilfs_btree_node *
409 nilfs_btree_get_root(const struct nilfs_bmap *btree)
410 {
411 return (struct nilfs_btree_node *)btree->b_u.u_data;
412 }
413
414 static struct nilfs_btree_node *
415 nilfs_btree_get_nonroot_node(const struct nilfs_btree_path *path, int level)
416 {
417 return (struct nilfs_btree_node *)path[level].bp_bh->b_data;
418 }
419
420 static struct nilfs_btree_node *
421 nilfs_btree_get_sib_node(const struct nilfs_btree_path *path, int level)
422 {
423 return (struct nilfs_btree_node *)path[level].bp_sib_bh->b_data;
424 }
425
426 static int nilfs_btree_height(const struct nilfs_bmap *btree)
427 {
428 return nilfs_btree_node_get_level(nilfs_btree_get_root(btree)) + 1;
429 }
430
431 static struct nilfs_btree_node *
432 nilfs_btree_get_node(const struct nilfs_bmap *btree,
433 const struct nilfs_btree_path *path,
434 int level, int *ncmaxp)
435 {
436 struct nilfs_btree_node *node;
437
438 if (level == nilfs_btree_height(btree) - 1) {
439 node = nilfs_btree_get_root(btree);
440 *ncmaxp = NILFS_BTREE_ROOT_NCHILDREN_MAX;
441 } else {
442 node = nilfs_btree_get_nonroot_node(path, level);
443 *ncmaxp = nilfs_btree_nchildren_per_block(btree);
444 }
445 return node;
446 }
447
448 static int nilfs_btree_bad_node(const struct nilfs_bmap *btree,
449 struct nilfs_btree_node *node, int level)
450 {
451 if (unlikely(nilfs_btree_node_get_level(node) != level)) {
452 dump_stack();
453 nilfs_crit(btree->b_inode->i_sb,
454 "btree level mismatch (ino=%lu): %d != %d",
455 btree->b_inode->i_ino,
456 nilfs_btree_node_get_level(node), level);
457 return 1;
458 }
459 return 0;
460 }
461
462 struct nilfs_btree_readahead_info {
463 struct nilfs_btree_node *node; /* parent node */
464 int max_ra_blocks; /* max nof blocks to read ahead */
465 int index; /* current index on the parent node */
466 int ncmax; /* nof children in the parent node */
467 };
468
469 static int __nilfs_btree_get_block(const struct nilfs_bmap *btree, __u64 ptr,
470 struct buffer_head **bhp,
471 const struct nilfs_btree_readahead_info *ra)
472 {
473 struct address_space *btnc = &NILFS_BMAP_I(btree)->i_btnode_cache;
474 struct buffer_head *bh, *ra_bh;
475 sector_t submit_ptr = 0;
476 int ret;
477
478 ret = nilfs_btnode_submit_block(btnc, ptr, 0, REQ_OP_READ, 0, &bh,
479 &submit_ptr);
480 if (ret) {
481 if (ret != -EEXIST)
482 return ret;
483 goto out_check;
484 }
485
486 if (ra) {
487 int i, n;
488 __u64 ptr2;
489
490 /* read ahead sibling nodes */
491 for (n = ra->max_ra_blocks, i = ra->index + 1;
492 n > 0 && i < ra->ncmax; n--, i++) {
493 ptr2 = nilfs_btree_node_get_ptr(ra->node, i, ra->ncmax);
494
495 ret = nilfs_btnode_submit_block(btnc, ptr2, 0,
496 REQ_OP_READ, REQ_RAHEAD,
497 &ra_bh, &submit_ptr);
498 if (likely(!ret || ret == -EEXIST))
499 brelse(ra_bh);
500 else if (ret != -EBUSY)
501 break;
502 if (!buffer_locked(bh))
503 goto out_no_wait;
504 }
505 }
506
507 wait_on_buffer(bh);
508
509 out_no_wait:
510 if (!buffer_uptodate(bh)) {
511 nilfs_err(btree->b_inode->i_sb,
512 "I/O error reading b-tree node block (ino=%lu, blocknr=%llu)",
513 btree->b_inode->i_ino, (unsigned long long)ptr);
514 brelse(bh);
515 return -EIO;
516 }
517
518 out_check:
519 if (nilfs_btree_broken_node_block(bh)) {
520 clear_buffer_uptodate(bh);
521 brelse(bh);
522 return -EINVAL;
523 }
524
525 *bhp = bh;
526 return 0;
527 }
528
529 static int nilfs_btree_get_block(const struct nilfs_bmap *btree, __u64 ptr,
530 struct buffer_head **bhp)
531 {
532 return __nilfs_btree_get_block(btree, ptr, bhp, NULL);
533 }
534
535 static int nilfs_btree_do_lookup(const struct nilfs_bmap *btree,
536 struct nilfs_btree_path *path,
537 __u64 key, __u64 *ptrp, int minlevel,
538 int readahead)
539 {
540 struct nilfs_btree_node *node;
541 struct nilfs_btree_readahead_info p, *ra;
542 __u64 ptr;
543 int level, index, found, ncmax, ret;
544
545 node = nilfs_btree_get_root(btree);
546 level = nilfs_btree_node_get_level(node);
547 if (level < minlevel || nilfs_btree_node_get_nchildren(node) <= 0)
548 return -ENOENT;
549
550 found = nilfs_btree_node_lookup(node, key, &index);
551 ptr = nilfs_btree_node_get_ptr(node, index,
552 NILFS_BTREE_ROOT_NCHILDREN_MAX);
553 path[level].bp_bh = NULL;
554 path[level].bp_index = index;
555
556 ncmax = nilfs_btree_nchildren_per_block(btree);
557
558 while (--level >= minlevel) {
559 ra = NULL;
560 if (level == NILFS_BTREE_LEVEL_NODE_MIN && readahead) {
561 p.node = nilfs_btree_get_node(btree, path, level + 1,
562 &p.ncmax);
563 p.index = index;
564 p.max_ra_blocks = 7;
565 ra = &p;
566 }
567 ret = __nilfs_btree_get_block(btree, ptr, &path[level].bp_bh,
568 ra);
569 if (ret < 0)
570 return ret;
571
572 node = nilfs_btree_get_nonroot_node(path, level);
573 if (nilfs_btree_bad_node(btree, node, level))
574 return -EINVAL;
575 if (!found)
576 found = nilfs_btree_node_lookup(node, key, &index);
577 else
578 index = 0;
579 if (index < ncmax) {
580 ptr = nilfs_btree_node_get_ptr(node, index, ncmax);
581 } else {
582 WARN_ON(found || level != NILFS_BTREE_LEVEL_NODE_MIN);
583 /* insert */
584 ptr = NILFS_BMAP_INVALID_PTR;
585 }
586 path[level].bp_index = index;
587 }
588 if (!found)
589 return -ENOENT;
590
591 if (ptrp != NULL)
592 *ptrp = ptr;
593
594 return 0;
595 }
596
597 static int nilfs_btree_do_lookup_last(const struct nilfs_bmap *btree,
598 struct nilfs_btree_path *path,
599 __u64 *keyp, __u64 *ptrp)
600 {
601 struct nilfs_btree_node *node;
602 __u64 ptr;
603 int index, level, ncmax, ret;
604
605 node = nilfs_btree_get_root(btree);
606 index = nilfs_btree_node_get_nchildren(node) - 1;
607 if (index < 0)
608 return -ENOENT;
609 level = nilfs_btree_node_get_level(node);
610 ptr = nilfs_btree_node_get_ptr(node, index,
611 NILFS_BTREE_ROOT_NCHILDREN_MAX);
612 path[level].bp_bh = NULL;
613 path[level].bp_index = index;
614 ncmax = nilfs_btree_nchildren_per_block(btree);
615
616 for (level--; level > 0; level--) {
617 ret = nilfs_btree_get_block(btree, ptr, &path[level].bp_bh);
618 if (ret < 0)
619 return ret;
620 node = nilfs_btree_get_nonroot_node(path, level);
621 if (nilfs_btree_bad_node(btree, node, level))
622 return -EINVAL;
623 index = nilfs_btree_node_get_nchildren(node) - 1;
624 ptr = nilfs_btree_node_get_ptr(node, index, ncmax);
625 path[level].bp_index = index;
626 }
627
628 if (keyp != NULL)
629 *keyp = nilfs_btree_node_get_key(node, index);
630 if (ptrp != NULL)
631 *ptrp = ptr;
632
633 return 0;
634 }
635
636 /**
637 * nilfs_btree_get_next_key - get next valid key from btree path array
638 * @btree: bmap struct of btree
639 * @path: array of nilfs_btree_path struct
640 * @minlevel: start level
641 * @nextkey: place to store the next valid key
642 *
643 * Return Value: If a next key was found, 0 is returned. Otherwise,
644 * -ENOENT is returned.
645 */
646 static int nilfs_btree_get_next_key(const struct nilfs_bmap *btree,
647 const struct nilfs_btree_path *path,
648 int minlevel, __u64 *nextkey)
649 {
650 struct nilfs_btree_node *node;
651 int maxlevel = nilfs_btree_height(btree) - 1;
652 int index, next_adj, level;
653
654 /* Next index is already set to bp_index for leaf nodes. */
655 next_adj = 0;
656 for (level = minlevel; level <= maxlevel; level++) {
657 if (level == maxlevel)
658 node = nilfs_btree_get_root(btree);
659 else
660 node = nilfs_btree_get_nonroot_node(path, level);
661
662 index = path[level].bp_index + next_adj;
663 if (index < nilfs_btree_node_get_nchildren(node)) {
664 /* Next key is in this node */
665 *nextkey = nilfs_btree_node_get_key(node, index);
666 return 0;
667 }
668 /* For non-leaf nodes, next index is stored at bp_index + 1. */
669 next_adj = 1;
670 }
671 return -ENOENT;
672 }
673
674 static int nilfs_btree_lookup(const struct nilfs_bmap *btree,
675 __u64 key, int level, __u64 *ptrp)
676 {
677 struct nilfs_btree_path *path;
678 int ret;
679
680 path = nilfs_btree_alloc_path();
681 if (path == NULL)
682 return -ENOMEM;
683
684 ret = nilfs_btree_do_lookup(btree, path, key, ptrp, level, 0);
685
686 nilfs_btree_free_path(path);
687
688 return ret;
689 }
690
691 static int nilfs_btree_lookup_contig(const struct nilfs_bmap *btree,
692 __u64 key, __u64 *ptrp,
693 unsigned int maxblocks)
694 {
695 struct nilfs_btree_path *path;
696 struct nilfs_btree_node *node;
697 struct inode *dat = NULL;
698 __u64 ptr, ptr2;
699 sector_t blocknr;
700 int level = NILFS_BTREE_LEVEL_NODE_MIN;
701 int ret, cnt, index, maxlevel, ncmax;
702 struct nilfs_btree_readahead_info p;
703
704 path = nilfs_btree_alloc_path();
705 if (path == NULL)
706 return -ENOMEM;
707
708 ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level, 1);
709 if (ret < 0)
710 goto out;
711
712 if (NILFS_BMAP_USE_VBN(btree)) {
713 dat = nilfs_bmap_get_dat(btree);
714 ret = nilfs_dat_translate(dat, ptr, &blocknr);
715 if (ret < 0)
716 goto out;
717 ptr = blocknr;
718 }
719 cnt = 1;
720 if (cnt == maxblocks)
721 goto end;
722
723 maxlevel = nilfs_btree_height(btree) - 1;
724 node = nilfs_btree_get_node(btree, path, level, &ncmax);
725 index = path[level].bp_index + 1;
726 for (;;) {
727 while (index < nilfs_btree_node_get_nchildren(node)) {
728 if (nilfs_btree_node_get_key(node, index) !=
729 key + cnt)
730 goto end;
731 ptr2 = nilfs_btree_node_get_ptr(node, index, ncmax);
732 if (dat) {
733 ret = nilfs_dat_translate(dat, ptr2, &blocknr);
734 if (ret < 0)
735 goto out;
736 ptr2 = blocknr;
737 }
738 if (ptr2 != ptr + cnt || ++cnt == maxblocks)
739 goto end;
740 index++;
741 continue;
742 }
743 if (level == maxlevel)
744 break;
745
746 /* look-up right sibling node */
747 p.node = nilfs_btree_get_node(btree, path, level + 1, &p.ncmax);
748 p.index = path[level + 1].bp_index + 1;
749 p.max_ra_blocks = 7;
750 if (p.index >= nilfs_btree_node_get_nchildren(p.node) ||
751 nilfs_btree_node_get_key(p.node, p.index) != key + cnt)
752 break;
753 ptr2 = nilfs_btree_node_get_ptr(p.node, p.index, p.ncmax);
754 path[level + 1].bp_index = p.index;
755
756 brelse(path[level].bp_bh);
757 path[level].bp_bh = NULL;
758
759 ret = __nilfs_btree_get_block(btree, ptr2, &path[level].bp_bh,
760 &p);
761 if (ret < 0)
762 goto out;
763 node = nilfs_btree_get_nonroot_node(path, level);
764 ncmax = nilfs_btree_nchildren_per_block(btree);
765 index = 0;
766 path[level].bp_index = index;
767 }
768 end:
769 *ptrp = ptr;
770 ret = cnt;
771 out:
772 nilfs_btree_free_path(path);
773 return ret;
774 }
775
776 static void nilfs_btree_promote_key(struct nilfs_bmap *btree,
777 struct nilfs_btree_path *path,
778 int level, __u64 key)
779 {
780 if (level < nilfs_btree_height(btree) - 1) {
781 do {
782 nilfs_btree_node_set_key(
783 nilfs_btree_get_nonroot_node(path, level),
784 path[level].bp_index, key);
785 if (!buffer_dirty(path[level].bp_bh))
786 mark_buffer_dirty(path[level].bp_bh);
787 } while ((path[level].bp_index == 0) &&
788 (++level < nilfs_btree_height(btree) - 1));
789 }
790
791 /* root */
792 if (level == nilfs_btree_height(btree) - 1) {
793 nilfs_btree_node_set_key(nilfs_btree_get_root(btree),
794 path[level].bp_index, key);
795 }
796 }
797
798 static void nilfs_btree_do_insert(struct nilfs_bmap *btree,
799 struct nilfs_btree_path *path,
800 int level, __u64 *keyp, __u64 *ptrp)
801 {
802 struct nilfs_btree_node *node;
803 int ncblk;
804
805 if (level < nilfs_btree_height(btree) - 1) {
806 node = nilfs_btree_get_nonroot_node(path, level);
807 ncblk = nilfs_btree_nchildren_per_block(btree);
808 nilfs_btree_node_insert(node, path[level].bp_index,
809 *keyp, *ptrp, ncblk);
810 if (!buffer_dirty(path[level].bp_bh))
811 mark_buffer_dirty(path[level].bp_bh);
812
813 if (path[level].bp_index == 0)
814 nilfs_btree_promote_key(btree, path, level + 1,
815 nilfs_btree_node_get_key(node,
816 0));
817 } else {
818 node = nilfs_btree_get_root(btree);
819 nilfs_btree_node_insert(node, path[level].bp_index,
820 *keyp, *ptrp,
821 NILFS_BTREE_ROOT_NCHILDREN_MAX);
822 }
823 }
824
825 static void nilfs_btree_carry_left(struct nilfs_bmap *btree,
826 struct nilfs_btree_path *path,
827 int level, __u64 *keyp, __u64 *ptrp)
828 {
829 struct nilfs_btree_node *node, *left;
830 int nchildren, lnchildren, n, move, ncblk;
831
832 node = nilfs_btree_get_nonroot_node(path, level);
833 left = nilfs_btree_get_sib_node(path, level);
834 nchildren = nilfs_btree_node_get_nchildren(node);
835 lnchildren = nilfs_btree_node_get_nchildren(left);
836 ncblk = nilfs_btree_nchildren_per_block(btree);
837 move = 0;
838
839 n = (nchildren + lnchildren + 1) / 2 - lnchildren;
840 if (n > path[level].bp_index) {
841 /* move insert point */
842 n--;
843 move = 1;
844 }
845
846 nilfs_btree_node_move_left(left, node, n, ncblk, ncblk);
847
848 if (!buffer_dirty(path[level].bp_bh))
849 mark_buffer_dirty(path[level].bp_bh);
850 if (!buffer_dirty(path[level].bp_sib_bh))
851 mark_buffer_dirty(path[level].bp_sib_bh);
852
853 nilfs_btree_promote_key(btree, path, level + 1,
854 nilfs_btree_node_get_key(node, 0));
855
856 if (move) {
857 brelse(path[level].bp_bh);
858 path[level].bp_bh = path[level].bp_sib_bh;
859 path[level].bp_sib_bh = NULL;
860 path[level].bp_index += lnchildren;
861 path[level + 1].bp_index--;
862 } else {
863 brelse(path[level].bp_sib_bh);
864 path[level].bp_sib_bh = NULL;
865 path[level].bp_index -= n;
866 }
867
868 nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
869 }
870
871 static void nilfs_btree_carry_right(struct nilfs_bmap *btree,
872 struct nilfs_btree_path *path,
873 int level, __u64 *keyp, __u64 *ptrp)
874 {
875 struct nilfs_btree_node *node, *right;
876 int nchildren, rnchildren, n, move, ncblk;
877
878 node = nilfs_btree_get_nonroot_node(path, level);
879 right = nilfs_btree_get_sib_node(path, level);
880 nchildren = nilfs_btree_node_get_nchildren(node);
881 rnchildren = nilfs_btree_node_get_nchildren(right);
882 ncblk = nilfs_btree_nchildren_per_block(btree);
883 move = 0;
884
885 n = (nchildren + rnchildren + 1) / 2 - rnchildren;
886 if (n > nchildren - path[level].bp_index) {
887 /* move insert point */
888 n--;
889 move = 1;
890 }
891
892 nilfs_btree_node_move_right(node, right, n, ncblk, ncblk);
893
894 if (!buffer_dirty(path[level].bp_bh))
895 mark_buffer_dirty(path[level].bp_bh);
896 if (!buffer_dirty(path[level].bp_sib_bh))
897 mark_buffer_dirty(path[level].bp_sib_bh);
898
899 path[level + 1].bp_index++;
900 nilfs_btree_promote_key(btree, path, level + 1,
901 nilfs_btree_node_get_key(right, 0));
902 path[level + 1].bp_index--;
903
904 if (move) {
905 brelse(path[level].bp_bh);
906 path[level].bp_bh = path[level].bp_sib_bh;
907 path[level].bp_sib_bh = NULL;
908 path[level].bp_index -= nilfs_btree_node_get_nchildren(node);
909 path[level + 1].bp_index++;
910 } else {
911 brelse(path[level].bp_sib_bh);
912 path[level].bp_sib_bh = NULL;
913 }
914
915 nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
916 }
917
918 static void nilfs_btree_split(struct nilfs_bmap *btree,
919 struct nilfs_btree_path *path,
920 int level, __u64 *keyp, __u64 *ptrp)
921 {
922 struct nilfs_btree_node *node, *right;
923 int nchildren, n, move, ncblk;
924
925 node = nilfs_btree_get_nonroot_node(path, level);
926 right = nilfs_btree_get_sib_node(path, level);
927 nchildren = nilfs_btree_node_get_nchildren(node);
928 ncblk = nilfs_btree_nchildren_per_block(btree);
929 move = 0;
930
931 n = (nchildren + 1) / 2;
932 if (n > nchildren - path[level].bp_index) {
933 n--;
934 move = 1;
935 }
936
937 nilfs_btree_node_move_right(node, right, n, ncblk, ncblk);
938
939 if (!buffer_dirty(path[level].bp_bh))
940 mark_buffer_dirty(path[level].bp_bh);
941 if (!buffer_dirty(path[level].bp_sib_bh))
942 mark_buffer_dirty(path[level].bp_sib_bh);
943
944 if (move) {
945 path[level].bp_index -= nilfs_btree_node_get_nchildren(node);
946 nilfs_btree_node_insert(right, path[level].bp_index,
947 *keyp, *ptrp, ncblk);
948
949 *keyp = nilfs_btree_node_get_key(right, 0);
950 *ptrp = path[level].bp_newreq.bpr_ptr;
951
952 brelse(path[level].bp_bh);
953 path[level].bp_bh = path[level].bp_sib_bh;
954 path[level].bp_sib_bh = NULL;
955 } else {
956 nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
957
958 *keyp = nilfs_btree_node_get_key(right, 0);
959 *ptrp = path[level].bp_newreq.bpr_ptr;
960
961 brelse(path[level].bp_sib_bh);
962 path[level].bp_sib_bh = NULL;
963 }
964
965 path[level + 1].bp_index++;
966 }
967
968 static void nilfs_btree_grow(struct nilfs_bmap *btree,
969 struct nilfs_btree_path *path,
970 int level, __u64 *keyp, __u64 *ptrp)
971 {
972 struct nilfs_btree_node *root, *child;
973 int n, ncblk;
974
975 root = nilfs_btree_get_root(btree);
976 child = nilfs_btree_get_sib_node(path, level);
977 ncblk = nilfs_btree_nchildren_per_block(btree);
978
979 n = nilfs_btree_node_get_nchildren(root);
980
981 nilfs_btree_node_move_right(root, child, n,
982 NILFS_BTREE_ROOT_NCHILDREN_MAX, ncblk);
983 nilfs_btree_node_set_level(root, level + 1);
984
985 if (!buffer_dirty(path[level].bp_sib_bh))
986 mark_buffer_dirty(path[level].bp_sib_bh);
987
988 path[level].bp_bh = path[level].bp_sib_bh;
989 path[level].bp_sib_bh = NULL;
990
991 nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
992
993 *keyp = nilfs_btree_node_get_key(child, 0);
994 *ptrp = path[level].bp_newreq.bpr_ptr;
995 }
996
997 static __u64 nilfs_btree_find_near(const struct nilfs_bmap *btree,
998 const struct nilfs_btree_path *path)
999 {
1000 struct nilfs_btree_node *node;
1001 int level, ncmax;
1002
1003 if (path == NULL)
1004 return NILFS_BMAP_INVALID_PTR;
1005
1006 /* left sibling */
1007 level = NILFS_BTREE_LEVEL_NODE_MIN;
1008 if (path[level].bp_index > 0) {
1009 node = nilfs_btree_get_node(btree, path, level, &ncmax);
1010 return nilfs_btree_node_get_ptr(node,
1011 path[level].bp_index - 1,
1012 ncmax);
1013 }
1014
1015 /* parent */
1016 level = NILFS_BTREE_LEVEL_NODE_MIN + 1;
1017 if (level <= nilfs_btree_height(btree) - 1) {
1018 node = nilfs_btree_get_node(btree, path, level, &ncmax);
1019 return nilfs_btree_node_get_ptr(node, path[level].bp_index,
1020 ncmax);
1021 }
1022
1023 return NILFS_BMAP_INVALID_PTR;
1024 }
1025
1026 static __u64 nilfs_btree_find_target_v(const struct nilfs_bmap *btree,
1027 const struct nilfs_btree_path *path,
1028 __u64 key)
1029 {
1030 __u64 ptr;
1031
1032 ptr = nilfs_bmap_find_target_seq(btree, key);
1033 if (ptr != NILFS_BMAP_INVALID_PTR)
1034 /* sequential access */
1035 return ptr;
1036
1037 ptr = nilfs_btree_find_near(btree, path);
1038 if (ptr != NILFS_BMAP_INVALID_PTR)
1039 /* near */
1040 return ptr;
1041
1042 /* block group */
1043 return nilfs_bmap_find_target_in_group(btree);
1044 }
1045
1046 static int nilfs_btree_prepare_insert(struct nilfs_bmap *btree,
1047 struct nilfs_btree_path *path,
1048 int *levelp, __u64 key, __u64 ptr,
1049 struct nilfs_bmap_stats *stats)
1050 {
1051 struct buffer_head *bh;
1052 struct nilfs_btree_node *node, *parent, *sib;
1053 __u64 sibptr;
1054 int pindex, level, ncmax, ncblk, ret;
1055 struct inode *dat = NULL;
1056
1057 stats->bs_nblocks = 0;
1058 level = NILFS_BTREE_LEVEL_DATA;
1059
1060 /* allocate a new ptr for data block */
1061 if (NILFS_BMAP_USE_VBN(btree)) {
1062 path[level].bp_newreq.bpr_ptr =
1063 nilfs_btree_find_target_v(btree, path, key);
1064 dat = nilfs_bmap_get_dat(btree);
1065 }
1066
1067 ret = nilfs_bmap_prepare_alloc_ptr(btree, &path[level].bp_newreq, dat);
1068 if (ret < 0)
1069 goto err_out_data;
1070
1071 ncblk = nilfs_btree_nchildren_per_block(btree);
1072
1073 for (level = NILFS_BTREE_LEVEL_NODE_MIN;
1074 level < nilfs_btree_height(btree) - 1;
1075 level++) {
1076 node = nilfs_btree_get_nonroot_node(path, level);
1077 if (nilfs_btree_node_get_nchildren(node) < ncblk) {
1078 path[level].bp_op = nilfs_btree_do_insert;
1079 stats->bs_nblocks++;
1080 goto out;
1081 }
1082
1083 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
1084 pindex = path[level + 1].bp_index;
1085
1086 /* left sibling */
1087 if (pindex > 0) {
1088 sibptr = nilfs_btree_node_get_ptr(parent, pindex - 1,
1089 ncmax);
1090 ret = nilfs_btree_get_block(btree, sibptr, &bh);
1091 if (ret < 0)
1092 goto err_out_child_node;
1093 sib = (struct nilfs_btree_node *)bh->b_data;
1094 if (nilfs_btree_node_get_nchildren(sib) < ncblk) {
1095 path[level].bp_sib_bh = bh;
1096 path[level].bp_op = nilfs_btree_carry_left;
1097 stats->bs_nblocks++;
1098 goto out;
1099 } else {
1100 brelse(bh);
1101 }
1102 }
1103
1104 /* right sibling */
1105 if (pindex < nilfs_btree_node_get_nchildren(parent) - 1) {
1106 sibptr = nilfs_btree_node_get_ptr(parent, pindex + 1,
1107 ncmax);
1108 ret = nilfs_btree_get_block(btree, sibptr, &bh);
1109 if (ret < 0)
1110 goto err_out_child_node;
1111 sib = (struct nilfs_btree_node *)bh->b_data;
1112 if (nilfs_btree_node_get_nchildren(sib) < ncblk) {
1113 path[level].bp_sib_bh = bh;
1114 path[level].bp_op = nilfs_btree_carry_right;
1115 stats->bs_nblocks++;
1116 goto out;
1117 } else {
1118 brelse(bh);
1119 }
1120 }
1121
1122 /* split */
1123 path[level].bp_newreq.bpr_ptr =
1124 path[level - 1].bp_newreq.bpr_ptr + 1;
1125 ret = nilfs_bmap_prepare_alloc_ptr(btree,
1126 &path[level].bp_newreq, dat);
1127 if (ret < 0)
1128 goto err_out_child_node;
1129 ret = nilfs_btree_get_new_block(btree,
1130 path[level].bp_newreq.bpr_ptr,
1131 &bh);
1132 if (ret < 0)
1133 goto err_out_curr_node;
1134
1135 stats->bs_nblocks++;
1136
1137 sib = (struct nilfs_btree_node *)bh->b_data;
1138 nilfs_btree_node_init(sib, 0, level, 0, ncblk, NULL, NULL);
1139 path[level].bp_sib_bh = bh;
1140 path[level].bp_op = nilfs_btree_split;
1141 }
1142
1143 /* root */
1144 node = nilfs_btree_get_root(btree);
1145 if (nilfs_btree_node_get_nchildren(node) <
1146 NILFS_BTREE_ROOT_NCHILDREN_MAX) {
1147 path[level].bp_op = nilfs_btree_do_insert;
1148 stats->bs_nblocks++;
1149 goto out;
1150 }
1151
1152 /* grow */
1153 path[level].bp_newreq.bpr_ptr = path[level - 1].bp_newreq.bpr_ptr + 1;
1154 ret = nilfs_bmap_prepare_alloc_ptr(btree, &path[level].bp_newreq, dat);
1155 if (ret < 0)
1156 goto err_out_child_node;
1157 ret = nilfs_btree_get_new_block(btree, path[level].bp_newreq.bpr_ptr,
1158 &bh);
1159 if (ret < 0)
1160 goto err_out_curr_node;
1161
1162 nilfs_btree_node_init((struct nilfs_btree_node *)bh->b_data,
1163 0, level, 0, ncblk, NULL, NULL);
1164 path[level].bp_sib_bh = bh;
1165 path[level].bp_op = nilfs_btree_grow;
1166
1167 level++;
1168 path[level].bp_op = nilfs_btree_do_insert;
1169
1170 /* a newly-created node block and a data block are added */
1171 stats->bs_nblocks += 2;
1172
1173 /* success */
1174 out:
1175 *levelp = level;
1176 return ret;
1177
1178 /* error */
1179 err_out_curr_node:
1180 nilfs_bmap_abort_alloc_ptr(btree, &path[level].bp_newreq, dat);
1181 err_out_child_node:
1182 for (level--; level > NILFS_BTREE_LEVEL_DATA; level--) {
1183 nilfs_btnode_delete(path[level].bp_sib_bh);
1184 nilfs_bmap_abort_alloc_ptr(btree, &path[level].bp_newreq, dat);
1185
1186 }
1187
1188 nilfs_bmap_abort_alloc_ptr(btree, &path[level].bp_newreq, dat);
1189 err_out_data:
1190 *levelp = level;
1191 stats->bs_nblocks = 0;
1192 return ret;
1193 }
1194
1195 static void nilfs_btree_commit_insert(struct nilfs_bmap *btree,
1196 struct nilfs_btree_path *path,
1197 int maxlevel, __u64 key, __u64 ptr)
1198 {
1199 struct inode *dat = NULL;
1200 int level;
1201
1202 set_buffer_nilfs_volatile((struct buffer_head *)((unsigned long)ptr));
1203 ptr = path[NILFS_BTREE_LEVEL_DATA].bp_newreq.bpr_ptr;
1204 if (NILFS_BMAP_USE_VBN(btree)) {
1205 nilfs_bmap_set_target_v(btree, key, ptr);
1206 dat = nilfs_bmap_get_dat(btree);
1207 }
1208
1209 for (level = NILFS_BTREE_LEVEL_NODE_MIN; level <= maxlevel; level++) {
1210 nilfs_bmap_commit_alloc_ptr(btree,
1211 &path[level - 1].bp_newreq, dat);
1212 path[level].bp_op(btree, path, level, &key, &ptr);
1213 }
1214
1215 if (!nilfs_bmap_dirty(btree))
1216 nilfs_bmap_set_dirty(btree);
1217 }
1218
1219 static int nilfs_btree_insert(struct nilfs_bmap *btree, __u64 key, __u64 ptr)
1220 {
1221 struct nilfs_btree_path *path;
1222 struct nilfs_bmap_stats stats;
1223 int level, ret;
1224
1225 path = nilfs_btree_alloc_path();
1226 if (path == NULL)
1227 return -ENOMEM;
1228
1229 ret = nilfs_btree_do_lookup(btree, path, key, NULL,
1230 NILFS_BTREE_LEVEL_NODE_MIN, 0);
1231 if (ret != -ENOENT) {
1232 if (ret == 0)
1233 ret = -EEXIST;
1234 goto out;
1235 }
1236
1237 ret = nilfs_btree_prepare_insert(btree, path, &level, key, ptr, &stats);
1238 if (ret < 0)
1239 goto out;
1240 nilfs_btree_commit_insert(btree, path, level, key, ptr);
1241 nilfs_inode_add_blocks(btree->b_inode, stats.bs_nblocks);
1242
1243 out:
1244 nilfs_btree_free_path(path);
1245 return ret;
1246 }
1247
1248 static void nilfs_btree_do_delete(struct nilfs_bmap *btree,
1249 struct nilfs_btree_path *path,
1250 int level, __u64 *keyp, __u64 *ptrp)
1251 {
1252 struct nilfs_btree_node *node;
1253 int ncblk;
1254
1255 if (level < nilfs_btree_height(btree) - 1) {
1256 node = nilfs_btree_get_nonroot_node(path, level);
1257 ncblk = nilfs_btree_nchildren_per_block(btree);
1258 nilfs_btree_node_delete(node, path[level].bp_index,
1259 keyp, ptrp, ncblk);
1260 if (!buffer_dirty(path[level].bp_bh))
1261 mark_buffer_dirty(path[level].bp_bh);
1262 if (path[level].bp_index == 0)
1263 nilfs_btree_promote_key(btree, path, level + 1,
1264 nilfs_btree_node_get_key(node, 0));
1265 } else {
1266 node = nilfs_btree_get_root(btree);
1267 nilfs_btree_node_delete(node, path[level].bp_index,
1268 keyp, ptrp,
1269 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1270 }
1271 }
1272
1273 static void nilfs_btree_borrow_left(struct nilfs_bmap *btree,
1274 struct nilfs_btree_path *path,
1275 int level, __u64 *keyp, __u64 *ptrp)
1276 {
1277 struct nilfs_btree_node *node, *left;
1278 int nchildren, lnchildren, n, ncblk;
1279
1280 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1281
1282 node = nilfs_btree_get_nonroot_node(path, level);
1283 left = nilfs_btree_get_sib_node(path, level);
1284 nchildren = nilfs_btree_node_get_nchildren(node);
1285 lnchildren = nilfs_btree_node_get_nchildren(left);
1286 ncblk = nilfs_btree_nchildren_per_block(btree);
1287
1288 n = (nchildren + lnchildren) / 2 - nchildren;
1289
1290 nilfs_btree_node_move_right(left, node, n, ncblk, ncblk);
1291
1292 if (!buffer_dirty(path[level].bp_bh))
1293 mark_buffer_dirty(path[level].bp_bh);
1294 if (!buffer_dirty(path[level].bp_sib_bh))
1295 mark_buffer_dirty(path[level].bp_sib_bh);
1296
1297 nilfs_btree_promote_key(btree, path, level + 1,
1298 nilfs_btree_node_get_key(node, 0));
1299
1300 brelse(path[level].bp_sib_bh);
1301 path[level].bp_sib_bh = NULL;
1302 path[level].bp_index += n;
1303 }
1304
1305 static void nilfs_btree_borrow_right(struct nilfs_bmap *btree,
1306 struct nilfs_btree_path *path,
1307 int level, __u64 *keyp, __u64 *ptrp)
1308 {
1309 struct nilfs_btree_node *node, *right;
1310 int nchildren, rnchildren, n, ncblk;
1311
1312 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1313
1314 node = nilfs_btree_get_nonroot_node(path, level);
1315 right = nilfs_btree_get_sib_node(path, level);
1316 nchildren = nilfs_btree_node_get_nchildren(node);
1317 rnchildren = nilfs_btree_node_get_nchildren(right);
1318 ncblk = nilfs_btree_nchildren_per_block(btree);
1319
1320 n = (nchildren + rnchildren) / 2 - nchildren;
1321
1322 nilfs_btree_node_move_left(node, right, n, ncblk, ncblk);
1323
1324 if (!buffer_dirty(path[level].bp_bh))
1325 mark_buffer_dirty(path[level].bp_bh);
1326 if (!buffer_dirty(path[level].bp_sib_bh))
1327 mark_buffer_dirty(path[level].bp_sib_bh);
1328
1329 path[level + 1].bp_index++;
1330 nilfs_btree_promote_key(btree, path, level + 1,
1331 nilfs_btree_node_get_key(right, 0));
1332 path[level + 1].bp_index--;
1333
1334 brelse(path[level].bp_sib_bh);
1335 path[level].bp_sib_bh = NULL;
1336 }
1337
1338 static void nilfs_btree_concat_left(struct nilfs_bmap *btree,
1339 struct nilfs_btree_path *path,
1340 int level, __u64 *keyp, __u64 *ptrp)
1341 {
1342 struct nilfs_btree_node *node, *left;
1343 int n, ncblk;
1344
1345 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1346
1347 node = nilfs_btree_get_nonroot_node(path, level);
1348 left = nilfs_btree_get_sib_node(path, level);
1349 ncblk = nilfs_btree_nchildren_per_block(btree);
1350
1351 n = nilfs_btree_node_get_nchildren(node);
1352
1353 nilfs_btree_node_move_left(left, node, n, ncblk, ncblk);
1354
1355 if (!buffer_dirty(path[level].bp_sib_bh))
1356 mark_buffer_dirty(path[level].bp_sib_bh);
1357
1358 nilfs_btnode_delete(path[level].bp_bh);
1359 path[level].bp_bh = path[level].bp_sib_bh;
1360 path[level].bp_sib_bh = NULL;
1361 path[level].bp_index += nilfs_btree_node_get_nchildren(left);
1362 }
1363
1364 static void nilfs_btree_concat_right(struct nilfs_bmap *btree,
1365 struct nilfs_btree_path *path,
1366 int level, __u64 *keyp, __u64 *ptrp)
1367 {
1368 struct nilfs_btree_node *node, *right;
1369 int n, ncblk;
1370
1371 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1372
1373 node = nilfs_btree_get_nonroot_node(path, level);
1374 right = nilfs_btree_get_sib_node(path, level);
1375 ncblk = nilfs_btree_nchildren_per_block(btree);
1376
1377 n = nilfs_btree_node_get_nchildren(right);
1378
1379 nilfs_btree_node_move_left(node, right, n, ncblk, ncblk);
1380
1381 if (!buffer_dirty(path[level].bp_bh))
1382 mark_buffer_dirty(path[level].bp_bh);
1383
1384 nilfs_btnode_delete(path[level].bp_sib_bh);
1385 path[level].bp_sib_bh = NULL;
1386 path[level + 1].bp_index++;
1387 }
1388
1389 static void nilfs_btree_shrink(struct nilfs_bmap *btree,
1390 struct nilfs_btree_path *path,
1391 int level, __u64 *keyp, __u64 *ptrp)
1392 {
1393 struct nilfs_btree_node *root, *child;
1394 int n, ncblk;
1395
1396 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1397
1398 root = nilfs_btree_get_root(btree);
1399 child = nilfs_btree_get_nonroot_node(path, level);
1400 ncblk = nilfs_btree_nchildren_per_block(btree);
1401
1402 nilfs_btree_node_delete(root, 0, NULL, NULL,
1403 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1404 nilfs_btree_node_set_level(root, level);
1405 n = nilfs_btree_node_get_nchildren(child);
1406 nilfs_btree_node_move_left(root, child, n,
1407 NILFS_BTREE_ROOT_NCHILDREN_MAX, ncblk);
1408
1409 nilfs_btnode_delete(path[level].bp_bh);
1410 path[level].bp_bh = NULL;
1411 }
1412
1413 static void nilfs_btree_nop(struct nilfs_bmap *btree,
1414 struct nilfs_btree_path *path,
1415 int level, __u64 *keyp, __u64 *ptrp)
1416 {
1417 }
1418
1419 static int nilfs_btree_prepare_delete(struct nilfs_bmap *btree,
1420 struct nilfs_btree_path *path,
1421 int *levelp,
1422 struct nilfs_bmap_stats *stats,
1423 struct inode *dat)
1424 {
1425 struct buffer_head *bh;
1426 struct nilfs_btree_node *node, *parent, *sib;
1427 __u64 sibptr;
1428 int pindex, dindex, level, ncmin, ncmax, ncblk, ret;
1429
1430 ret = 0;
1431 stats->bs_nblocks = 0;
1432 ncmin = NILFS_BTREE_NODE_NCHILDREN_MIN(nilfs_btree_node_size(btree));
1433 ncblk = nilfs_btree_nchildren_per_block(btree);
1434
1435 for (level = NILFS_BTREE_LEVEL_NODE_MIN, dindex = path[level].bp_index;
1436 level < nilfs_btree_height(btree) - 1;
1437 level++) {
1438 node = nilfs_btree_get_nonroot_node(path, level);
1439 path[level].bp_oldreq.bpr_ptr =
1440 nilfs_btree_node_get_ptr(node, dindex, ncblk);
1441 ret = nilfs_bmap_prepare_end_ptr(btree,
1442 &path[level].bp_oldreq, dat);
1443 if (ret < 0)
1444 goto err_out_child_node;
1445
1446 if (nilfs_btree_node_get_nchildren(node) > ncmin) {
1447 path[level].bp_op = nilfs_btree_do_delete;
1448 stats->bs_nblocks++;
1449 goto out;
1450 }
1451
1452 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
1453 pindex = path[level + 1].bp_index;
1454 dindex = pindex;
1455
1456 if (pindex > 0) {
1457 /* left sibling */
1458 sibptr = nilfs_btree_node_get_ptr(parent, pindex - 1,
1459 ncmax);
1460 ret = nilfs_btree_get_block(btree, sibptr, &bh);
1461 if (ret < 0)
1462 goto err_out_curr_node;
1463 sib = (struct nilfs_btree_node *)bh->b_data;
1464 if (nilfs_btree_node_get_nchildren(sib) > ncmin) {
1465 path[level].bp_sib_bh = bh;
1466 path[level].bp_op = nilfs_btree_borrow_left;
1467 stats->bs_nblocks++;
1468 goto out;
1469 } else {
1470 path[level].bp_sib_bh = bh;
1471 path[level].bp_op = nilfs_btree_concat_left;
1472 stats->bs_nblocks++;
1473 /* continue; */
1474 }
1475 } else if (pindex <
1476 nilfs_btree_node_get_nchildren(parent) - 1) {
1477 /* right sibling */
1478 sibptr = nilfs_btree_node_get_ptr(parent, pindex + 1,
1479 ncmax);
1480 ret = nilfs_btree_get_block(btree, sibptr, &bh);
1481 if (ret < 0)
1482 goto err_out_curr_node;
1483 sib = (struct nilfs_btree_node *)bh->b_data;
1484 if (nilfs_btree_node_get_nchildren(sib) > ncmin) {
1485 path[level].bp_sib_bh = bh;
1486 path[level].bp_op = nilfs_btree_borrow_right;
1487 stats->bs_nblocks++;
1488 goto out;
1489 } else {
1490 path[level].bp_sib_bh = bh;
1491 path[level].bp_op = nilfs_btree_concat_right;
1492 stats->bs_nblocks++;
1493 /*
1494 * When merging right sibling node
1495 * into the current node, pointer to
1496 * the right sibling node must be
1497 * terminated instead. The adjustment
1498 * below is required for that.
1499 */
1500 dindex = pindex + 1;
1501 /* continue; */
1502 }
1503 } else {
1504 /* no siblings */
1505 /* the only child of the root node */
1506 WARN_ON(level != nilfs_btree_height(btree) - 2);
1507 if (nilfs_btree_node_get_nchildren(node) - 1 <=
1508 NILFS_BTREE_ROOT_NCHILDREN_MAX) {
1509 path[level].bp_op = nilfs_btree_shrink;
1510 stats->bs_nblocks += 2;
1511 level++;
1512 path[level].bp_op = nilfs_btree_nop;
1513 goto shrink_root_child;
1514 } else {
1515 path[level].bp_op = nilfs_btree_do_delete;
1516 stats->bs_nblocks++;
1517 goto out;
1518 }
1519 }
1520 }
1521
1522 /* child of the root node is deleted */
1523 path[level].bp_op = nilfs_btree_do_delete;
1524 stats->bs_nblocks++;
1525
1526 shrink_root_child:
1527 node = nilfs_btree_get_root(btree);
1528 path[level].bp_oldreq.bpr_ptr =
1529 nilfs_btree_node_get_ptr(node, dindex,
1530 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1531
1532 ret = nilfs_bmap_prepare_end_ptr(btree, &path[level].bp_oldreq, dat);
1533 if (ret < 0)
1534 goto err_out_child_node;
1535
1536 /* success */
1537 out:
1538 *levelp = level;
1539 return ret;
1540
1541 /* error */
1542 err_out_curr_node:
1543 nilfs_bmap_abort_end_ptr(btree, &path[level].bp_oldreq, dat);
1544 err_out_child_node:
1545 for (level--; level >= NILFS_BTREE_LEVEL_NODE_MIN; level--) {
1546 brelse(path[level].bp_sib_bh);
1547 nilfs_bmap_abort_end_ptr(btree, &path[level].bp_oldreq, dat);
1548 }
1549 *levelp = level;
1550 stats->bs_nblocks = 0;
1551 return ret;
1552 }
1553
1554 static void nilfs_btree_commit_delete(struct nilfs_bmap *btree,
1555 struct nilfs_btree_path *path,
1556 int maxlevel, struct inode *dat)
1557 {
1558 int level;
1559
1560 for (level = NILFS_BTREE_LEVEL_NODE_MIN; level <= maxlevel; level++) {
1561 nilfs_bmap_commit_end_ptr(btree, &path[level].bp_oldreq, dat);
1562 path[level].bp_op(btree, path, level, NULL, NULL);
1563 }
1564
1565 if (!nilfs_bmap_dirty(btree))
1566 nilfs_bmap_set_dirty(btree);
1567 }
1568
1569 static int nilfs_btree_delete(struct nilfs_bmap *btree, __u64 key)
1570
1571 {
1572 struct nilfs_btree_path *path;
1573 struct nilfs_bmap_stats stats;
1574 struct inode *dat;
1575 int level, ret;
1576
1577 path = nilfs_btree_alloc_path();
1578 if (path == NULL)
1579 return -ENOMEM;
1580
1581 ret = nilfs_btree_do_lookup(btree, path, key, NULL,
1582 NILFS_BTREE_LEVEL_NODE_MIN, 0);
1583 if (ret < 0)
1584 goto out;
1585
1586
1587 dat = NILFS_BMAP_USE_VBN(btree) ? nilfs_bmap_get_dat(btree) : NULL;
1588
1589 ret = nilfs_btree_prepare_delete(btree, path, &level, &stats, dat);
1590 if (ret < 0)
1591 goto out;
1592 nilfs_btree_commit_delete(btree, path, level, dat);
1593 nilfs_inode_sub_blocks(btree->b_inode, stats.bs_nblocks);
1594
1595 out:
1596 nilfs_btree_free_path(path);
1597 return ret;
1598 }
1599
1600 static int nilfs_btree_seek_key(const struct nilfs_bmap *btree, __u64 start,
1601 __u64 *keyp)
1602 {
1603 struct nilfs_btree_path *path;
1604 const int minlevel = NILFS_BTREE_LEVEL_NODE_MIN;
1605 int ret;
1606
1607 path = nilfs_btree_alloc_path();
1608 if (!path)
1609 return -ENOMEM;
1610
1611 ret = nilfs_btree_do_lookup(btree, path, start, NULL, minlevel, 0);
1612 if (!ret)
1613 *keyp = start;
1614 else if (ret == -ENOENT)
1615 ret = nilfs_btree_get_next_key(btree, path, minlevel, keyp);
1616
1617 nilfs_btree_free_path(path);
1618 return ret;
1619 }
1620
1621 static int nilfs_btree_last_key(const struct nilfs_bmap *btree, __u64 *keyp)
1622 {
1623 struct nilfs_btree_path *path;
1624 int ret;
1625
1626 path = nilfs_btree_alloc_path();
1627 if (path == NULL)
1628 return -ENOMEM;
1629
1630 ret = nilfs_btree_do_lookup_last(btree, path, keyp, NULL);
1631
1632 nilfs_btree_free_path(path);
1633
1634 return ret;
1635 }
1636
1637 static int nilfs_btree_check_delete(struct nilfs_bmap *btree, __u64 key)
1638 {
1639 struct buffer_head *bh;
1640 struct nilfs_btree_node *root, *node;
1641 __u64 maxkey, nextmaxkey;
1642 __u64 ptr;
1643 int nchildren, ret;
1644
1645 root = nilfs_btree_get_root(btree);
1646 switch (nilfs_btree_height(btree)) {
1647 case 2:
1648 bh = NULL;
1649 node = root;
1650 break;
1651 case 3:
1652 nchildren = nilfs_btree_node_get_nchildren(root);
1653 if (nchildren > 1)
1654 return 0;
1655 ptr = nilfs_btree_node_get_ptr(root, nchildren - 1,
1656 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1657 ret = nilfs_btree_get_block(btree, ptr, &bh);
1658 if (ret < 0)
1659 return ret;
1660 node = (struct nilfs_btree_node *)bh->b_data;
1661 break;
1662 default:
1663 return 0;
1664 }
1665
1666 nchildren = nilfs_btree_node_get_nchildren(node);
1667 maxkey = nilfs_btree_node_get_key(node, nchildren - 1);
1668 nextmaxkey = (nchildren > 1) ?
1669 nilfs_btree_node_get_key(node, nchildren - 2) : 0;
1670 if (bh != NULL)
1671 brelse(bh);
1672
1673 return (maxkey == key) && (nextmaxkey < NILFS_BMAP_LARGE_LOW);
1674 }
1675
1676 static int nilfs_btree_gather_data(struct nilfs_bmap *btree,
1677 __u64 *keys, __u64 *ptrs, int nitems)
1678 {
1679 struct buffer_head *bh;
1680 struct nilfs_btree_node *node, *root;
1681 __le64 *dkeys;
1682 __le64 *dptrs;
1683 __u64 ptr;
1684 int nchildren, ncmax, i, ret;
1685
1686 root = nilfs_btree_get_root(btree);
1687 switch (nilfs_btree_height(btree)) {
1688 case 2:
1689 bh = NULL;
1690 node = root;
1691 ncmax = NILFS_BTREE_ROOT_NCHILDREN_MAX;
1692 break;
1693 case 3:
1694 nchildren = nilfs_btree_node_get_nchildren(root);
1695 WARN_ON(nchildren > 1);
1696 ptr = nilfs_btree_node_get_ptr(root, nchildren - 1,
1697 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1698 ret = nilfs_btree_get_block(btree, ptr, &bh);
1699 if (ret < 0)
1700 return ret;
1701 node = (struct nilfs_btree_node *)bh->b_data;
1702 ncmax = nilfs_btree_nchildren_per_block(btree);
1703 break;
1704 default:
1705 node = NULL;
1706 return -EINVAL;
1707 }
1708
1709 nchildren = nilfs_btree_node_get_nchildren(node);
1710 if (nchildren < nitems)
1711 nitems = nchildren;
1712 dkeys = nilfs_btree_node_dkeys(node);
1713 dptrs = nilfs_btree_node_dptrs(node, ncmax);
1714 for (i = 0; i < nitems; i++) {
1715 keys[i] = le64_to_cpu(dkeys[i]);
1716 ptrs[i] = le64_to_cpu(dptrs[i]);
1717 }
1718
1719 if (bh != NULL)
1720 brelse(bh);
1721
1722 return nitems;
1723 }
1724
1725 static int
1726 nilfs_btree_prepare_convert_and_insert(struct nilfs_bmap *btree, __u64 key,
1727 union nilfs_bmap_ptr_req *dreq,
1728 union nilfs_bmap_ptr_req *nreq,
1729 struct buffer_head **bhp,
1730 struct nilfs_bmap_stats *stats)
1731 {
1732 struct buffer_head *bh;
1733 struct inode *dat = NULL;
1734 int ret;
1735
1736 stats->bs_nblocks = 0;
1737
1738 /* for data */
1739 /* cannot find near ptr */
1740 if (NILFS_BMAP_USE_VBN(btree)) {
1741 dreq->bpr_ptr = nilfs_btree_find_target_v(btree, NULL, key);
1742 dat = nilfs_bmap_get_dat(btree);
1743 }
1744
1745 ret = nilfs_bmap_prepare_alloc_ptr(btree, dreq, dat);
1746 if (ret < 0)
1747 return ret;
1748
1749 *bhp = NULL;
1750 stats->bs_nblocks++;
1751 if (nreq != NULL) {
1752 nreq->bpr_ptr = dreq->bpr_ptr + 1;
1753 ret = nilfs_bmap_prepare_alloc_ptr(btree, nreq, dat);
1754 if (ret < 0)
1755 goto err_out_dreq;
1756
1757 ret = nilfs_btree_get_new_block(btree, nreq->bpr_ptr, &bh);
1758 if (ret < 0)
1759 goto err_out_nreq;
1760
1761 *bhp = bh;
1762 stats->bs_nblocks++;
1763 }
1764
1765 /* success */
1766 return 0;
1767
1768 /* error */
1769 err_out_nreq:
1770 nilfs_bmap_abort_alloc_ptr(btree, nreq, dat);
1771 err_out_dreq:
1772 nilfs_bmap_abort_alloc_ptr(btree, dreq, dat);
1773 stats->bs_nblocks = 0;
1774 return ret;
1775
1776 }
1777
1778 static void
1779 nilfs_btree_commit_convert_and_insert(struct nilfs_bmap *btree,
1780 __u64 key, __u64 ptr,
1781 const __u64 *keys, const __u64 *ptrs,
1782 int n,
1783 union nilfs_bmap_ptr_req *dreq,
1784 union nilfs_bmap_ptr_req *nreq,
1785 struct buffer_head *bh)
1786 {
1787 struct nilfs_btree_node *node;
1788 struct inode *dat;
1789 __u64 tmpptr;
1790 int ncblk;
1791
1792 /* free resources */
1793 if (btree->b_ops->bop_clear != NULL)
1794 btree->b_ops->bop_clear(btree);
1795
1796 /* ptr must be a pointer to a buffer head. */
1797 set_buffer_nilfs_volatile((struct buffer_head *)((unsigned long)ptr));
1798
1799 /* convert and insert */
1800 dat = NILFS_BMAP_USE_VBN(btree) ? nilfs_bmap_get_dat(btree) : NULL;
1801 __nilfs_btree_init(btree);
1802 if (nreq != NULL) {
1803 nilfs_bmap_commit_alloc_ptr(btree, dreq, dat);
1804 nilfs_bmap_commit_alloc_ptr(btree, nreq, dat);
1805
1806 /* create child node at level 1 */
1807 node = (struct nilfs_btree_node *)bh->b_data;
1808 ncblk = nilfs_btree_nchildren_per_block(btree);
1809 nilfs_btree_node_init(node, 0, 1, n, ncblk, keys, ptrs);
1810 nilfs_btree_node_insert(node, n, key, dreq->bpr_ptr, ncblk);
1811 if (!buffer_dirty(bh))
1812 mark_buffer_dirty(bh);
1813 if (!nilfs_bmap_dirty(btree))
1814 nilfs_bmap_set_dirty(btree);
1815
1816 brelse(bh);
1817
1818 /* create root node at level 2 */
1819 node = nilfs_btree_get_root(btree);
1820 tmpptr = nreq->bpr_ptr;
1821 nilfs_btree_node_init(node, NILFS_BTREE_NODE_ROOT, 2, 1,
1822 NILFS_BTREE_ROOT_NCHILDREN_MAX,
1823 &keys[0], &tmpptr);
1824 } else {
1825 nilfs_bmap_commit_alloc_ptr(btree, dreq, dat);
1826
1827 /* create root node at level 1 */
1828 node = nilfs_btree_get_root(btree);
1829 nilfs_btree_node_init(node, NILFS_BTREE_NODE_ROOT, 1, n,
1830 NILFS_BTREE_ROOT_NCHILDREN_MAX,
1831 keys, ptrs);
1832 nilfs_btree_node_insert(node, n, key, dreq->bpr_ptr,
1833 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1834 if (!nilfs_bmap_dirty(btree))
1835 nilfs_bmap_set_dirty(btree);
1836 }
1837
1838 if (NILFS_BMAP_USE_VBN(btree))
1839 nilfs_bmap_set_target_v(btree, key, dreq->bpr_ptr);
1840 }
1841
1842 /**
1843 * nilfs_btree_convert_and_insert -
1844 * @bmap:
1845 * @key:
1846 * @ptr:
1847 * @keys:
1848 * @ptrs:
1849 * @n:
1850 */
1851 int nilfs_btree_convert_and_insert(struct nilfs_bmap *btree,
1852 __u64 key, __u64 ptr,
1853 const __u64 *keys, const __u64 *ptrs, int n)
1854 {
1855 struct buffer_head *bh = NULL;
1856 union nilfs_bmap_ptr_req dreq, nreq, *di, *ni;
1857 struct nilfs_bmap_stats stats;
1858 int ret;
1859
1860 if (n + 1 <= NILFS_BTREE_ROOT_NCHILDREN_MAX) {
1861 di = &dreq;
1862 ni = NULL;
1863 } else if ((n + 1) <= NILFS_BTREE_NODE_NCHILDREN_MAX(
1864 nilfs_btree_node_size(btree))) {
1865 di = &dreq;
1866 ni = &nreq;
1867 } else {
1868 di = NULL;
1869 ni = NULL;
1870 BUG();
1871 }
1872
1873 ret = nilfs_btree_prepare_convert_and_insert(btree, key, di, ni, &bh,
1874 &stats);
1875 if (ret < 0)
1876 return ret;
1877 nilfs_btree_commit_convert_and_insert(btree, key, ptr, keys, ptrs, n,
1878 di, ni, bh);
1879 nilfs_inode_add_blocks(btree->b_inode, stats.bs_nblocks);
1880 return 0;
1881 }
1882
1883 static int nilfs_btree_propagate_p(struct nilfs_bmap *btree,
1884 struct nilfs_btree_path *path,
1885 int level,
1886 struct buffer_head *bh)
1887 {
1888 while ((++level < nilfs_btree_height(btree) - 1) &&
1889 !buffer_dirty(path[level].bp_bh))
1890 mark_buffer_dirty(path[level].bp_bh);
1891
1892 return 0;
1893 }
1894
1895 static int nilfs_btree_prepare_update_v(struct nilfs_bmap *btree,
1896 struct nilfs_btree_path *path,
1897 int level, struct inode *dat)
1898 {
1899 struct nilfs_btree_node *parent;
1900 int ncmax, ret;
1901
1902 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
1903 path[level].bp_oldreq.bpr_ptr =
1904 nilfs_btree_node_get_ptr(parent, path[level + 1].bp_index,
1905 ncmax);
1906 path[level].bp_newreq.bpr_ptr = path[level].bp_oldreq.bpr_ptr + 1;
1907 ret = nilfs_dat_prepare_update(dat, &path[level].bp_oldreq.bpr_req,
1908 &path[level].bp_newreq.bpr_req);
1909 if (ret < 0)
1910 return ret;
1911
1912 if (buffer_nilfs_node(path[level].bp_bh)) {
1913 path[level].bp_ctxt.oldkey = path[level].bp_oldreq.bpr_ptr;
1914 path[level].bp_ctxt.newkey = path[level].bp_newreq.bpr_ptr;
1915 path[level].bp_ctxt.bh = path[level].bp_bh;
1916 ret = nilfs_btnode_prepare_change_key(
1917 &NILFS_BMAP_I(btree)->i_btnode_cache,
1918 &path[level].bp_ctxt);
1919 if (ret < 0) {
1920 nilfs_dat_abort_update(dat,
1921 &path[level].bp_oldreq.bpr_req,
1922 &path[level].bp_newreq.bpr_req);
1923 return ret;
1924 }
1925 }
1926
1927 return 0;
1928 }
1929
1930 static void nilfs_btree_commit_update_v(struct nilfs_bmap *btree,
1931 struct nilfs_btree_path *path,
1932 int level, struct inode *dat)
1933 {
1934 struct nilfs_btree_node *parent;
1935 int ncmax;
1936
1937 nilfs_dat_commit_update(dat, &path[level].bp_oldreq.bpr_req,
1938 &path[level].bp_newreq.bpr_req,
1939 btree->b_ptr_type == NILFS_BMAP_PTR_VS);
1940
1941 if (buffer_nilfs_node(path[level].bp_bh)) {
1942 nilfs_btnode_commit_change_key(
1943 &NILFS_BMAP_I(btree)->i_btnode_cache,
1944 &path[level].bp_ctxt);
1945 path[level].bp_bh = path[level].bp_ctxt.bh;
1946 }
1947 set_buffer_nilfs_volatile(path[level].bp_bh);
1948
1949 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
1950 nilfs_btree_node_set_ptr(parent, path[level + 1].bp_index,
1951 path[level].bp_newreq.bpr_ptr, ncmax);
1952 }
1953
1954 static void nilfs_btree_abort_update_v(struct nilfs_bmap *btree,
1955 struct nilfs_btree_path *path,
1956 int level, struct inode *dat)
1957 {
1958 nilfs_dat_abort_update(dat, &path[level].bp_oldreq.bpr_req,
1959 &path[level].bp_newreq.bpr_req);
1960 if (buffer_nilfs_node(path[level].bp_bh))
1961 nilfs_btnode_abort_change_key(
1962 &NILFS_BMAP_I(btree)->i_btnode_cache,
1963 &path[level].bp_ctxt);
1964 }
1965
1966 static int nilfs_btree_prepare_propagate_v(struct nilfs_bmap *btree,
1967 struct nilfs_btree_path *path,
1968 int minlevel, int *maxlevelp,
1969 struct inode *dat)
1970 {
1971 int level, ret;
1972
1973 level = minlevel;
1974 if (!buffer_nilfs_volatile(path[level].bp_bh)) {
1975 ret = nilfs_btree_prepare_update_v(btree, path, level, dat);
1976 if (ret < 0)
1977 return ret;
1978 }
1979 while ((++level < nilfs_btree_height(btree) - 1) &&
1980 !buffer_dirty(path[level].bp_bh)) {
1981
1982 WARN_ON(buffer_nilfs_volatile(path[level].bp_bh));
1983 ret = nilfs_btree_prepare_update_v(btree, path, level, dat);
1984 if (ret < 0)
1985 goto out;
1986 }
1987
1988 /* success */
1989 *maxlevelp = level - 1;
1990 return 0;
1991
1992 /* error */
1993 out:
1994 while (--level > minlevel)
1995 nilfs_btree_abort_update_v(btree, path, level, dat);
1996 if (!buffer_nilfs_volatile(path[level].bp_bh))
1997 nilfs_btree_abort_update_v(btree, path, level, dat);
1998 return ret;
1999 }
2000
2001 static void nilfs_btree_commit_propagate_v(struct nilfs_bmap *btree,
2002 struct nilfs_btree_path *path,
2003 int minlevel, int maxlevel,
2004 struct buffer_head *bh,
2005 struct inode *dat)
2006 {
2007 int level;
2008
2009 if (!buffer_nilfs_volatile(path[minlevel].bp_bh))
2010 nilfs_btree_commit_update_v(btree, path, minlevel, dat);
2011
2012 for (level = minlevel + 1; level <= maxlevel; level++)
2013 nilfs_btree_commit_update_v(btree, path, level, dat);
2014 }
2015
2016 static int nilfs_btree_propagate_v(struct nilfs_bmap *btree,
2017 struct nilfs_btree_path *path,
2018 int level, struct buffer_head *bh)
2019 {
2020 int maxlevel = 0, ret;
2021 struct nilfs_btree_node *parent;
2022 struct inode *dat = nilfs_bmap_get_dat(btree);
2023 __u64 ptr;
2024 int ncmax;
2025
2026 get_bh(bh);
2027 path[level].bp_bh = bh;
2028 ret = nilfs_btree_prepare_propagate_v(btree, path, level, &maxlevel,
2029 dat);
2030 if (ret < 0)
2031 goto out;
2032
2033 if (buffer_nilfs_volatile(path[level].bp_bh)) {
2034 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
2035 ptr = nilfs_btree_node_get_ptr(parent,
2036 path[level + 1].bp_index,
2037 ncmax);
2038 ret = nilfs_dat_mark_dirty(dat, ptr);
2039 if (ret < 0)
2040 goto out;
2041 }
2042
2043 nilfs_btree_commit_propagate_v(btree, path, level, maxlevel, bh, dat);
2044
2045 out:
2046 brelse(path[level].bp_bh);
2047 path[level].bp_bh = NULL;
2048 return ret;
2049 }
2050
2051 static int nilfs_btree_propagate(struct nilfs_bmap *btree,
2052 struct buffer_head *bh)
2053 {
2054 struct nilfs_btree_path *path;
2055 struct nilfs_btree_node *node;
2056 __u64 key;
2057 int level, ret;
2058
2059 WARN_ON(!buffer_dirty(bh));
2060
2061 path = nilfs_btree_alloc_path();
2062 if (path == NULL)
2063 return -ENOMEM;
2064
2065 if (buffer_nilfs_node(bh)) {
2066 node = (struct nilfs_btree_node *)bh->b_data;
2067 key = nilfs_btree_node_get_key(node, 0);
2068 level = nilfs_btree_node_get_level(node);
2069 } else {
2070 key = nilfs_bmap_data_get_key(btree, bh);
2071 level = NILFS_BTREE_LEVEL_DATA;
2072 }
2073
2074 ret = nilfs_btree_do_lookup(btree, path, key, NULL, level + 1, 0);
2075 if (ret < 0) {
2076 if (unlikely(ret == -ENOENT))
2077 nilfs_crit(btree->b_inode->i_sb,
2078 "writing node/leaf block does not appear in b-tree (ino=%lu) at key=%llu, level=%d",
2079 btree->b_inode->i_ino,
2080 (unsigned long long)key, level);
2081 goto out;
2082 }
2083
2084 ret = NILFS_BMAP_USE_VBN(btree) ?
2085 nilfs_btree_propagate_v(btree, path, level, bh) :
2086 nilfs_btree_propagate_p(btree, path, level, bh);
2087
2088 out:
2089 nilfs_btree_free_path(path);
2090
2091 return ret;
2092 }
2093
2094 static int nilfs_btree_propagate_gc(struct nilfs_bmap *btree,
2095 struct buffer_head *bh)
2096 {
2097 return nilfs_dat_mark_dirty(nilfs_bmap_get_dat(btree), bh->b_blocknr);
2098 }
2099
2100 static void nilfs_btree_add_dirty_buffer(struct nilfs_bmap *btree,
2101 struct list_head *lists,
2102 struct buffer_head *bh)
2103 {
2104 struct list_head *head;
2105 struct buffer_head *cbh;
2106 struct nilfs_btree_node *node, *cnode;
2107 __u64 key, ckey;
2108 int level;
2109
2110 get_bh(bh);
2111 node = (struct nilfs_btree_node *)bh->b_data;
2112 key = nilfs_btree_node_get_key(node, 0);
2113 level = nilfs_btree_node_get_level(node);
2114 if (level < NILFS_BTREE_LEVEL_NODE_MIN ||
2115 level >= NILFS_BTREE_LEVEL_MAX) {
2116 dump_stack();
2117 nilfs_warn(btree->b_inode->i_sb,
2118 "invalid btree level: %d (key=%llu, ino=%lu, blocknr=%llu)",
2119 level, (unsigned long long)key,
2120 btree->b_inode->i_ino,
2121 (unsigned long long)bh->b_blocknr);
2122 return;
2123 }
2124
2125 list_for_each(head, &lists[level]) {
2126 cbh = list_entry(head, struct buffer_head, b_assoc_buffers);
2127 cnode = (struct nilfs_btree_node *)cbh->b_data;
2128 ckey = nilfs_btree_node_get_key(cnode, 0);
2129 if (key < ckey)
2130 break;
2131 }
2132 list_add_tail(&bh->b_assoc_buffers, head);
2133 }
2134
2135 static void nilfs_btree_lookup_dirty_buffers(struct nilfs_bmap *btree,
2136 struct list_head *listp)
2137 {
2138 struct address_space *btcache = &NILFS_BMAP_I(btree)->i_btnode_cache;
2139 struct list_head lists[NILFS_BTREE_LEVEL_MAX];
2140 struct pagevec pvec;
2141 struct buffer_head *bh, *head;
2142 pgoff_t index = 0;
2143 int level, i;
2144
2145 for (level = NILFS_BTREE_LEVEL_NODE_MIN;
2146 level < NILFS_BTREE_LEVEL_MAX;
2147 level++)
2148 INIT_LIST_HEAD(&lists[level]);
2149
2150 pagevec_init(&pvec);
2151
2152 while (pagevec_lookup_tag(&pvec, btcache, &index,
2153 PAGECACHE_TAG_DIRTY)) {
2154 for (i = 0; i < pagevec_count(&pvec); i++) {
2155 bh = head = page_buffers(pvec.pages[i]);
2156 do {
2157 if (buffer_dirty(bh))
2158 nilfs_btree_add_dirty_buffer(btree,
2159 lists, bh);
2160 } while ((bh = bh->b_this_page) != head);
2161 }
2162 pagevec_release(&pvec);
2163 cond_resched();
2164 }
2165
2166 for (level = NILFS_BTREE_LEVEL_NODE_MIN;
2167 level < NILFS_BTREE_LEVEL_MAX;
2168 level++)
2169 list_splice_tail(&lists[level], listp);
2170 }
2171
2172 static int nilfs_btree_assign_p(struct nilfs_bmap *btree,
2173 struct nilfs_btree_path *path,
2174 int level,
2175 struct buffer_head **bh,
2176 sector_t blocknr,
2177 union nilfs_binfo *binfo)
2178 {
2179 struct nilfs_btree_node *parent;
2180 __u64 key;
2181 __u64 ptr;
2182 int ncmax, ret;
2183
2184 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
2185 ptr = nilfs_btree_node_get_ptr(parent, path[level + 1].bp_index,
2186 ncmax);
2187 if (buffer_nilfs_node(*bh)) {
2188 path[level].bp_ctxt.oldkey = ptr;
2189 path[level].bp_ctxt.newkey = blocknr;
2190 path[level].bp_ctxt.bh = *bh;
2191 ret = nilfs_btnode_prepare_change_key(
2192 &NILFS_BMAP_I(btree)->i_btnode_cache,
2193 &path[level].bp_ctxt);
2194 if (ret < 0)
2195 return ret;
2196 nilfs_btnode_commit_change_key(
2197 &NILFS_BMAP_I(btree)->i_btnode_cache,
2198 &path[level].bp_ctxt);
2199 *bh = path[level].bp_ctxt.bh;
2200 }
2201
2202 nilfs_btree_node_set_ptr(parent, path[level + 1].bp_index, blocknr,
2203 ncmax);
2204
2205 key = nilfs_btree_node_get_key(parent, path[level + 1].bp_index);
2206 /* on-disk format */
2207 binfo->bi_dat.bi_blkoff = cpu_to_le64(key);
2208 binfo->bi_dat.bi_level = level;
2209
2210 return 0;
2211 }
2212
2213 static int nilfs_btree_assign_v(struct nilfs_bmap *btree,
2214 struct nilfs_btree_path *path,
2215 int level,
2216 struct buffer_head **bh,
2217 sector_t blocknr,
2218 union nilfs_binfo *binfo)
2219 {
2220 struct nilfs_btree_node *parent;
2221 struct inode *dat = nilfs_bmap_get_dat(btree);
2222 __u64 key;
2223 __u64 ptr;
2224 union nilfs_bmap_ptr_req req;
2225 int ncmax, ret;
2226
2227 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
2228 ptr = nilfs_btree_node_get_ptr(parent, path[level + 1].bp_index,
2229 ncmax);
2230 req.bpr_ptr = ptr;
2231 ret = nilfs_dat_prepare_start(dat, &req.bpr_req);
2232 if (ret < 0)
2233 return ret;
2234 nilfs_dat_commit_start(dat, &req.bpr_req, blocknr);
2235
2236 key = nilfs_btree_node_get_key(parent, path[level + 1].bp_index);
2237 /* on-disk format */
2238 binfo->bi_v.bi_vblocknr = cpu_to_le64(ptr);
2239 binfo->bi_v.bi_blkoff = cpu_to_le64(key);
2240
2241 return 0;
2242 }
2243
2244 static int nilfs_btree_assign(struct nilfs_bmap *btree,
2245 struct buffer_head **bh,
2246 sector_t blocknr,
2247 union nilfs_binfo *binfo)
2248 {
2249 struct nilfs_btree_path *path;
2250 struct nilfs_btree_node *node;
2251 __u64 key;
2252 int level, ret;
2253
2254 path = nilfs_btree_alloc_path();
2255 if (path == NULL)
2256 return -ENOMEM;
2257
2258 if (buffer_nilfs_node(*bh)) {
2259 node = (struct nilfs_btree_node *)(*bh)->b_data;
2260 key = nilfs_btree_node_get_key(node, 0);
2261 level = nilfs_btree_node_get_level(node);
2262 } else {
2263 key = nilfs_bmap_data_get_key(btree, *bh);
2264 level = NILFS_BTREE_LEVEL_DATA;
2265 }
2266
2267 ret = nilfs_btree_do_lookup(btree, path, key, NULL, level + 1, 0);
2268 if (ret < 0) {
2269 WARN_ON(ret == -ENOENT);
2270 goto out;
2271 }
2272
2273 ret = NILFS_BMAP_USE_VBN(btree) ?
2274 nilfs_btree_assign_v(btree, path, level, bh, blocknr, binfo) :
2275 nilfs_btree_assign_p(btree, path, level, bh, blocknr, binfo);
2276
2277 out:
2278 nilfs_btree_free_path(path);
2279
2280 return ret;
2281 }
2282
2283 static int nilfs_btree_assign_gc(struct nilfs_bmap *btree,
2284 struct buffer_head **bh,
2285 sector_t blocknr,
2286 union nilfs_binfo *binfo)
2287 {
2288 struct nilfs_btree_node *node;
2289 __u64 key;
2290 int ret;
2291
2292 ret = nilfs_dat_move(nilfs_bmap_get_dat(btree), (*bh)->b_blocknr,
2293 blocknr);
2294 if (ret < 0)
2295 return ret;
2296
2297 if (buffer_nilfs_node(*bh)) {
2298 node = (struct nilfs_btree_node *)(*bh)->b_data;
2299 key = nilfs_btree_node_get_key(node, 0);
2300 } else
2301 key = nilfs_bmap_data_get_key(btree, *bh);
2302
2303 /* on-disk format */
2304 binfo->bi_v.bi_vblocknr = cpu_to_le64((*bh)->b_blocknr);
2305 binfo->bi_v.bi_blkoff = cpu_to_le64(key);
2306
2307 return 0;
2308 }
2309
2310 static int nilfs_btree_mark(struct nilfs_bmap *btree, __u64 key, int level)
2311 {
2312 struct buffer_head *bh;
2313 struct nilfs_btree_path *path;
2314 __u64 ptr;
2315 int ret;
2316
2317 path = nilfs_btree_alloc_path();
2318 if (path == NULL)
2319 return -ENOMEM;
2320
2321 ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level + 1, 0);
2322 if (ret < 0) {
2323 WARN_ON(ret == -ENOENT);
2324 goto out;
2325 }
2326 ret = nilfs_btree_get_block(btree, ptr, &bh);
2327 if (ret < 0) {
2328 WARN_ON(ret == -ENOENT);
2329 goto out;
2330 }
2331
2332 if (!buffer_dirty(bh))
2333 mark_buffer_dirty(bh);
2334 brelse(bh);
2335 if (!nilfs_bmap_dirty(btree))
2336 nilfs_bmap_set_dirty(btree);
2337
2338 out:
2339 nilfs_btree_free_path(path);
2340 return ret;
2341 }
2342
2343 static const struct nilfs_bmap_operations nilfs_btree_ops = {
2344 .bop_lookup = nilfs_btree_lookup,
2345 .bop_lookup_contig = nilfs_btree_lookup_contig,
2346 .bop_insert = nilfs_btree_insert,
2347 .bop_delete = nilfs_btree_delete,
2348 .bop_clear = NULL,
2349
2350 .bop_propagate = nilfs_btree_propagate,
2351
2352 .bop_lookup_dirty_buffers = nilfs_btree_lookup_dirty_buffers,
2353
2354 .bop_assign = nilfs_btree_assign,
2355 .bop_mark = nilfs_btree_mark,
2356
2357 .bop_seek_key = nilfs_btree_seek_key,
2358 .bop_last_key = nilfs_btree_last_key,
2359
2360 .bop_check_insert = NULL,
2361 .bop_check_delete = nilfs_btree_check_delete,
2362 .bop_gather_data = nilfs_btree_gather_data,
2363 };
2364
2365 static const struct nilfs_bmap_operations nilfs_btree_ops_gc = {
2366 .bop_lookup = NULL,
2367 .bop_lookup_contig = NULL,
2368 .bop_insert = NULL,
2369 .bop_delete = NULL,
2370 .bop_clear = NULL,
2371
2372 .bop_propagate = nilfs_btree_propagate_gc,
2373
2374 .bop_lookup_dirty_buffers = nilfs_btree_lookup_dirty_buffers,
2375
2376 .bop_assign = nilfs_btree_assign_gc,
2377 .bop_mark = NULL,
2378
2379 .bop_seek_key = NULL,
2380 .bop_last_key = NULL,
2381
2382 .bop_check_insert = NULL,
2383 .bop_check_delete = NULL,
2384 .bop_gather_data = NULL,
2385 };
2386
2387 static void __nilfs_btree_init(struct nilfs_bmap *bmap)
2388 {
2389 bmap->b_ops = &nilfs_btree_ops;
2390 bmap->b_nchildren_per_block =
2391 NILFS_BTREE_NODE_NCHILDREN_MAX(nilfs_btree_node_size(bmap));
2392 }
2393
2394 int nilfs_btree_init(struct nilfs_bmap *bmap)
2395 {
2396 int ret = 0;
2397
2398 __nilfs_btree_init(bmap);
2399
2400 if (nilfs_btree_root_broken(nilfs_btree_get_root(bmap), bmap->b_inode))
2401 ret = -EIO;
2402 return ret;
2403 }
2404
2405 void nilfs_btree_init_gc(struct nilfs_bmap *bmap)
2406 {
2407 bmap->b_ops = &nilfs_btree_ops_gc;
2408 bmap->b_nchildren_per_block =
2409 NILFS_BTREE_NODE_NCHILDREN_MAX(nilfs_btree_node_size(bmap));
2410 }
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