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Merge branches 'for-4.4/upstream-fixes', 'for-4.5/async-suspend', 'for-4.5/container...
[mirror_ubuntu-artful-kernel.git] / fs / nilfs2 / btree.c
1 /*
2 * btree.c - NILFS B-tree.
3 *
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 *
20 * Written by Koji Sato <koji@osrg.net>.
21 */
22
23 #include <linux/slab.h>
24 #include <linux/string.h>
25 #include <linux/errno.h>
26 #include <linux/pagevec.h>
27 #include "nilfs.h"
28 #include "page.h"
29 #include "btnode.h"
30 #include "btree.h"
31 #include "alloc.h"
32 #include "dat.h"
33
34 static void __nilfs_btree_init(struct nilfs_bmap *bmap);
35
36 static struct nilfs_btree_path *nilfs_btree_alloc_path(void)
37 {
38 struct nilfs_btree_path *path;
39 int level = NILFS_BTREE_LEVEL_DATA;
40
41 path = kmem_cache_alloc(nilfs_btree_path_cache, GFP_NOFS);
42 if (path == NULL)
43 goto out;
44
45 for (; level < NILFS_BTREE_LEVEL_MAX; level++) {
46 path[level].bp_bh = NULL;
47 path[level].bp_sib_bh = NULL;
48 path[level].bp_index = 0;
49 path[level].bp_oldreq.bpr_ptr = NILFS_BMAP_INVALID_PTR;
50 path[level].bp_newreq.bpr_ptr = NILFS_BMAP_INVALID_PTR;
51 path[level].bp_op = NULL;
52 }
53
54 out:
55 return path;
56 }
57
58 static void nilfs_btree_free_path(struct nilfs_btree_path *path)
59 {
60 int level = NILFS_BTREE_LEVEL_DATA;
61
62 for (; level < NILFS_BTREE_LEVEL_MAX; level++)
63 brelse(path[level].bp_bh);
64
65 kmem_cache_free(nilfs_btree_path_cache, path);
66 }
67
68 /*
69 * B-tree node operations
70 */
71 static int nilfs_btree_get_new_block(const struct nilfs_bmap *btree,
72 __u64 ptr, struct buffer_head **bhp)
73 {
74 struct address_space *btnc = &NILFS_BMAP_I(btree)->i_btnode_cache;
75 struct buffer_head *bh;
76
77 bh = nilfs_btnode_create_block(btnc, ptr);
78 if (!bh)
79 return -ENOMEM;
80
81 set_buffer_nilfs_volatile(bh);
82 *bhp = bh;
83 return 0;
84 }
85
86 static int nilfs_btree_node_get_flags(const struct nilfs_btree_node *node)
87 {
88 return node->bn_flags;
89 }
90
91 static void
92 nilfs_btree_node_set_flags(struct nilfs_btree_node *node, int flags)
93 {
94 node->bn_flags = flags;
95 }
96
97 static int nilfs_btree_node_root(const struct nilfs_btree_node *node)
98 {
99 return nilfs_btree_node_get_flags(node) & NILFS_BTREE_NODE_ROOT;
100 }
101
102 static int nilfs_btree_node_get_level(const struct nilfs_btree_node *node)
103 {
104 return node->bn_level;
105 }
106
107 static void
108 nilfs_btree_node_set_level(struct nilfs_btree_node *node, int level)
109 {
110 node->bn_level = level;
111 }
112
113 static int nilfs_btree_node_get_nchildren(const struct nilfs_btree_node *node)
114 {
115 return le16_to_cpu(node->bn_nchildren);
116 }
117
118 static void
119 nilfs_btree_node_set_nchildren(struct nilfs_btree_node *node, int nchildren)
120 {
121 node->bn_nchildren = cpu_to_le16(nchildren);
122 }
123
124 static int nilfs_btree_node_size(const struct nilfs_bmap *btree)
125 {
126 return 1 << btree->b_inode->i_blkbits;
127 }
128
129 static int nilfs_btree_nchildren_per_block(const struct nilfs_bmap *btree)
130 {
131 return btree->b_nchildren_per_block;
132 }
133
134 static __le64 *
135 nilfs_btree_node_dkeys(const struct nilfs_btree_node *node)
136 {
137 return (__le64 *)((char *)(node + 1) +
138 (nilfs_btree_node_root(node) ?
139 0 : NILFS_BTREE_NODE_EXTRA_PAD_SIZE));
140 }
141
142 static __le64 *
143 nilfs_btree_node_dptrs(const struct nilfs_btree_node *node, int ncmax)
144 {
145 return (__le64 *)(nilfs_btree_node_dkeys(node) + ncmax);
146 }
147
148 static __u64
149 nilfs_btree_node_get_key(const struct nilfs_btree_node *node, int index)
150 {
151 return le64_to_cpu(*(nilfs_btree_node_dkeys(node) + index));
152 }
153
154 static void
155 nilfs_btree_node_set_key(struct nilfs_btree_node *node, int index, __u64 key)
156 {
157 *(nilfs_btree_node_dkeys(node) + index) = cpu_to_le64(key);
158 }
159
160 static __u64
161 nilfs_btree_node_get_ptr(const struct nilfs_btree_node *node, int index,
162 int ncmax)
163 {
164 return le64_to_cpu(*(nilfs_btree_node_dptrs(node, ncmax) + index));
165 }
166
167 static void
168 nilfs_btree_node_set_ptr(struct nilfs_btree_node *node, int index, __u64 ptr,
169 int ncmax)
170 {
171 *(nilfs_btree_node_dptrs(node, ncmax) + index) = cpu_to_le64(ptr);
172 }
173
174 static void nilfs_btree_node_init(struct nilfs_btree_node *node, int flags,
175 int level, int nchildren, int ncmax,
176 const __u64 *keys, const __u64 *ptrs)
177 {
178 __le64 *dkeys;
179 __le64 *dptrs;
180 int i;
181
182 nilfs_btree_node_set_flags(node, flags);
183 nilfs_btree_node_set_level(node, level);
184 nilfs_btree_node_set_nchildren(node, nchildren);
185
186 dkeys = nilfs_btree_node_dkeys(node);
187 dptrs = nilfs_btree_node_dptrs(node, ncmax);
188 for (i = 0; i < nchildren; i++) {
189 dkeys[i] = cpu_to_le64(keys[i]);
190 dptrs[i] = cpu_to_le64(ptrs[i]);
191 }
192 }
193
194 /* Assume the buffer heads corresponding to left and right are locked. */
195 static void nilfs_btree_node_move_left(struct nilfs_btree_node *left,
196 struct nilfs_btree_node *right,
197 int n, int lncmax, int rncmax)
198 {
199 __le64 *ldkeys, *rdkeys;
200 __le64 *ldptrs, *rdptrs;
201 int lnchildren, rnchildren;
202
203 ldkeys = nilfs_btree_node_dkeys(left);
204 ldptrs = nilfs_btree_node_dptrs(left, lncmax);
205 lnchildren = nilfs_btree_node_get_nchildren(left);
206
207 rdkeys = nilfs_btree_node_dkeys(right);
208 rdptrs = nilfs_btree_node_dptrs(right, rncmax);
209 rnchildren = nilfs_btree_node_get_nchildren(right);
210
211 memcpy(ldkeys + lnchildren, rdkeys, n * sizeof(*rdkeys));
212 memcpy(ldptrs + lnchildren, rdptrs, n * sizeof(*rdptrs));
213 memmove(rdkeys, rdkeys + n, (rnchildren - n) * sizeof(*rdkeys));
214 memmove(rdptrs, rdptrs + n, (rnchildren - n) * sizeof(*rdptrs));
215
216 lnchildren += n;
217 rnchildren -= n;
218 nilfs_btree_node_set_nchildren(left, lnchildren);
219 nilfs_btree_node_set_nchildren(right, rnchildren);
220 }
221
222 /* Assume that the buffer heads corresponding to left and right are locked. */
223 static void nilfs_btree_node_move_right(struct nilfs_btree_node *left,
224 struct nilfs_btree_node *right,
225 int n, int lncmax, int rncmax)
226 {
227 __le64 *ldkeys, *rdkeys;
228 __le64 *ldptrs, *rdptrs;
229 int lnchildren, rnchildren;
230
231 ldkeys = nilfs_btree_node_dkeys(left);
232 ldptrs = nilfs_btree_node_dptrs(left, lncmax);
233 lnchildren = nilfs_btree_node_get_nchildren(left);
234
235 rdkeys = nilfs_btree_node_dkeys(right);
236 rdptrs = nilfs_btree_node_dptrs(right, rncmax);
237 rnchildren = nilfs_btree_node_get_nchildren(right);
238
239 memmove(rdkeys + n, rdkeys, rnchildren * sizeof(*rdkeys));
240 memmove(rdptrs + n, rdptrs, rnchildren * sizeof(*rdptrs));
241 memcpy(rdkeys, ldkeys + lnchildren - n, n * sizeof(*rdkeys));
242 memcpy(rdptrs, ldptrs + lnchildren - n, n * sizeof(*rdptrs));
243
244 lnchildren -= n;
245 rnchildren += n;
246 nilfs_btree_node_set_nchildren(left, lnchildren);
247 nilfs_btree_node_set_nchildren(right, rnchildren);
248 }
249
250 /* Assume that the buffer head corresponding to node is locked. */
251 static void nilfs_btree_node_insert(struct nilfs_btree_node *node, int index,
252 __u64 key, __u64 ptr, int ncmax)
253 {
254 __le64 *dkeys;
255 __le64 *dptrs;
256 int nchildren;
257
258 dkeys = nilfs_btree_node_dkeys(node);
259 dptrs = nilfs_btree_node_dptrs(node, ncmax);
260 nchildren = nilfs_btree_node_get_nchildren(node);
261 if (index < nchildren) {
262 memmove(dkeys + index + 1, dkeys + index,
263 (nchildren - index) * sizeof(*dkeys));
264 memmove(dptrs + index + 1, dptrs + index,
265 (nchildren - index) * sizeof(*dptrs));
266 }
267 dkeys[index] = cpu_to_le64(key);
268 dptrs[index] = cpu_to_le64(ptr);
269 nchildren++;
270 nilfs_btree_node_set_nchildren(node, nchildren);
271 }
272
273 /* Assume that the buffer head corresponding to node is locked. */
274 static void nilfs_btree_node_delete(struct nilfs_btree_node *node, int index,
275 __u64 *keyp, __u64 *ptrp, int ncmax)
276 {
277 __u64 key;
278 __u64 ptr;
279 __le64 *dkeys;
280 __le64 *dptrs;
281 int nchildren;
282
283 dkeys = nilfs_btree_node_dkeys(node);
284 dptrs = nilfs_btree_node_dptrs(node, ncmax);
285 key = le64_to_cpu(dkeys[index]);
286 ptr = le64_to_cpu(dptrs[index]);
287 nchildren = nilfs_btree_node_get_nchildren(node);
288 if (keyp != NULL)
289 *keyp = key;
290 if (ptrp != NULL)
291 *ptrp = ptr;
292
293 if (index < nchildren - 1) {
294 memmove(dkeys + index, dkeys + index + 1,
295 (nchildren - index - 1) * sizeof(*dkeys));
296 memmove(dptrs + index, dptrs + index + 1,
297 (nchildren - index - 1) * sizeof(*dptrs));
298 }
299 nchildren--;
300 nilfs_btree_node_set_nchildren(node, nchildren);
301 }
302
303 static int nilfs_btree_node_lookup(const struct nilfs_btree_node *node,
304 __u64 key, int *indexp)
305 {
306 __u64 nkey;
307 int index, low, high, s;
308
309 /* binary search */
310 low = 0;
311 high = nilfs_btree_node_get_nchildren(node) - 1;
312 index = 0;
313 s = 0;
314 while (low <= high) {
315 index = (low + high) / 2;
316 nkey = nilfs_btree_node_get_key(node, index);
317 if (nkey == key) {
318 s = 0;
319 goto out;
320 } else if (nkey < key) {
321 low = index + 1;
322 s = -1;
323 } else {
324 high = index - 1;
325 s = 1;
326 }
327 }
328
329 /* adjust index */
330 if (nilfs_btree_node_get_level(node) > NILFS_BTREE_LEVEL_NODE_MIN) {
331 if (s > 0 && index > 0)
332 index--;
333 } else if (s < 0)
334 index++;
335
336 out:
337 *indexp = index;
338
339 return s == 0;
340 }
341
342 /**
343 * nilfs_btree_node_broken - verify consistency of btree node
344 * @node: btree node block to be examined
345 * @size: node size (in bytes)
346 * @blocknr: block number
347 *
348 * Return Value: If node is broken, 1 is returned. Otherwise, 0 is returned.
349 */
350 static int nilfs_btree_node_broken(const struct nilfs_btree_node *node,
351 size_t size, sector_t blocknr)
352 {
353 int level, flags, nchildren;
354 int ret = 0;
355
356 level = nilfs_btree_node_get_level(node);
357 flags = nilfs_btree_node_get_flags(node);
358 nchildren = nilfs_btree_node_get_nchildren(node);
359
360 if (unlikely(level < NILFS_BTREE_LEVEL_NODE_MIN ||
361 level >= NILFS_BTREE_LEVEL_MAX ||
362 (flags & NILFS_BTREE_NODE_ROOT) ||
363 nchildren < 0 ||
364 nchildren > NILFS_BTREE_NODE_NCHILDREN_MAX(size))) {
365 printk(KERN_CRIT "NILFS: bad btree node (blocknr=%llu): "
366 "level = %d, flags = 0x%x, nchildren = %d\n",
367 (unsigned long long)blocknr, level, flags, nchildren);
368 ret = 1;
369 }
370 return ret;
371 }
372
373 /**
374 * nilfs_btree_root_broken - verify consistency of btree root node
375 * @node: btree root node to be examined
376 * @ino: inode number
377 *
378 * Return Value: If node is broken, 1 is returned. Otherwise, 0 is returned.
379 */
380 static int nilfs_btree_root_broken(const struct nilfs_btree_node *node,
381 unsigned long ino)
382 {
383 int level, flags, nchildren;
384 int ret = 0;
385
386 level = nilfs_btree_node_get_level(node);
387 flags = nilfs_btree_node_get_flags(node);
388 nchildren = nilfs_btree_node_get_nchildren(node);
389
390 if (unlikely(level < NILFS_BTREE_LEVEL_NODE_MIN ||
391 level >= NILFS_BTREE_LEVEL_MAX ||
392 nchildren < 0 ||
393 nchildren > NILFS_BTREE_ROOT_NCHILDREN_MAX)) {
394 pr_crit("NILFS: bad btree root (inode number=%lu): level = %d, flags = 0x%x, nchildren = %d\n",
395 ino, level, flags, nchildren);
396 ret = 1;
397 }
398 return ret;
399 }
400
401 int nilfs_btree_broken_node_block(struct buffer_head *bh)
402 {
403 int ret;
404
405 if (buffer_nilfs_checked(bh))
406 return 0;
407
408 ret = nilfs_btree_node_broken((struct nilfs_btree_node *)bh->b_data,
409 bh->b_size, bh->b_blocknr);
410 if (likely(!ret))
411 set_buffer_nilfs_checked(bh);
412 return ret;
413 }
414
415 static struct nilfs_btree_node *
416 nilfs_btree_get_root(const struct nilfs_bmap *btree)
417 {
418 return (struct nilfs_btree_node *)btree->b_u.u_data;
419 }
420
421 static struct nilfs_btree_node *
422 nilfs_btree_get_nonroot_node(const struct nilfs_btree_path *path, int level)
423 {
424 return (struct nilfs_btree_node *)path[level].bp_bh->b_data;
425 }
426
427 static struct nilfs_btree_node *
428 nilfs_btree_get_sib_node(const struct nilfs_btree_path *path, int level)
429 {
430 return (struct nilfs_btree_node *)path[level].bp_sib_bh->b_data;
431 }
432
433 static int nilfs_btree_height(const struct nilfs_bmap *btree)
434 {
435 return nilfs_btree_node_get_level(nilfs_btree_get_root(btree)) + 1;
436 }
437
438 static struct nilfs_btree_node *
439 nilfs_btree_get_node(const struct nilfs_bmap *btree,
440 const struct nilfs_btree_path *path,
441 int level, int *ncmaxp)
442 {
443 struct nilfs_btree_node *node;
444
445 if (level == nilfs_btree_height(btree) - 1) {
446 node = nilfs_btree_get_root(btree);
447 *ncmaxp = NILFS_BTREE_ROOT_NCHILDREN_MAX;
448 } else {
449 node = nilfs_btree_get_nonroot_node(path, level);
450 *ncmaxp = nilfs_btree_nchildren_per_block(btree);
451 }
452 return node;
453 }
454
455 static int
456 nilfs_btree_bad_node(struct nilfs_btree_node *node, int level)
457 {
458 if (unlikely(nilfs_btree_node_get_level(node) != level)) {
459 dump_stack();
460 printk(KERN_CRIT "NILFS: btree level mismatch: %d != %d\n",
461 nilfs_btree_node_get_level(node), level);
462 return 1;
463 }
464 return 0;
465 }
466
467 struct nilfs_btree_readahead_info {
468 struct nilfs_btree_node *node; /* parent node */
469 int max_ra_blocks; /* max nof blocks to read ahead */
470 int index; /* current index on the parent node */
471 int ncmax; /* nof children in the parent node */
472 };
473
474 static int __nilfs_btree_get_block(const struct nilfs_bmap *btree, __u64 ptr,
475 struct buffer_head **bhp,
476 const struct nilfs_btree_readahead_info *ra)
477 {
478 struct address_space *btnc = &NILFS_BMAP_I(btree)->i_btnode_cache;
479 struct buffer_head *bh, *ra_bh;
480 sector_t submit_ptr = 0;
481 int ret;
482
483 ret = nilfs_btnode_submit_block(btnc, ptr, 0, READ, &bh, &submit_ptr);
484 if (ret) {
485 if (ret != -EEXIST)
486 return ret;
487 goto out_check;
488 }
489
490 if (ra) {
491 int i, n;
492 __u64 ptr2;
493
494 /* read ahead sibling nodes */
495 for (n = ra->max_ra_blocks, i = ra->index + 1;
496 n > 0 && i < ra->ncmax; n--, i++) {
497 ptr2 = nilfs_btree_node_get_ptr(ra->node, i, ra->ncmax);
498
499 ret = nilfs_btnode_submit_block(btnc, ptr2, 0, READA,
500 &ra_bh, &submit_ptr);
501 if (likely(!ret || ret == -EEXIST))
502 brelse(ra_bh);
503 else if (ret != -EBUSY)
504 break;
505 if (!buffer_locked(bh))
506 goto out_no_wait;
507 }
508 }
509
510 wait_on_buffer(bh);
511
512 out_no_wait:
513 if (!buffer_uptodate(bh)) {
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(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(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, unsigned maxblocks)
693 {
694 struct nilfs_btree_path *path;
695 struct nilfs_btree_node *node;
696 struct inode *dat = NULL;
697 __u64 ptr, ptr2;
698 sector_t blocknr;
699 int level = NILFS_BTREE_LEVEL_NODE_MIN;
700 int ret, cnt, index, maxlevel, ncmax;
701 struct nilfs_btree_readahead_info p;
702
703 path = nilfs_btree_alloc_path();
704 if (path == NULL)
705 return -ENOMEM;
706
707 ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level, 1);
708 if (ret < 0)
709 goto out;
710
711 if (NILFS_BMAP_USE_VBN(btree)) {
712 dat = nilfs_bmap_get_dat(btree);
713 ret = nilfs_dat_translate(dat, ptr, &blocknr);
714 if (ret < 0)
715 goto out;
716 ptr = blocknr;
717 }
718 cnt = 1;
719 if (cnt == maxblocks)
720 goto end;
721
722 maxlevel = nilfs_btree_height(btree) - 1;
723 node = nilfs_btree_get_node(btree, path, level, &ncmax);
724 index = path[level].bp_index + 1;
725 for (;;) {
726 while (index < nilfs_btree_node_get_nchildren(node)) {
727 if (nilfs_btree_node_get_key(node, index) !=
728 key + cnt)
729 goto end;
730 ptr2 = nilfs_btree_node_get_ptr(node, index, ncmax);
731 if (dat) {
732 ret = nilfs_dat_translate(dat, ptr2, &blocknr);
733 if (ret < 0)
734 goto out;
735 ptr2 = blocknr;
736 }
737 if (ptr2 != ptr + cnt || ++cnt == maxblocks)
738 goto end;
739 index++;
740 continue;
741 }
742 if (level == maxlevel)
743 break;
744
745 /* look-up right sibling node */
746 p.node = nilfs_btree_get_node(btree, path, level + 1, &p.ncmax);
747 p.index = path[level + 1].bp_index + 1;
748 p.max_ra_blocks = 7;
749 if (p.index >= nilfs_btree_node_get_nchildren(p.node) ||
750 nilfs_btree_node_get_key(p.node, p.index) != key + cnt)
751 break;
752 ptr2 = nilfs_btree_node_get_ptr(p.node, p.index, p.ncmax);
753 path[level + 1].bp_index = p.index;
754
755 brelse(path[level].bp_bh);
756 path[level].bp_bh = NULL;
757
758 ret = __nilfs_btree_get_block(btree, ptr2, &path[level].bp_bh,
759 &p);
760 if (ret < 0)
761 goto out;
762 node = nilfs_btree_get_nonroot_node(path, level);
763 ncmax = nilfs_btree_nchildren_per_block(btree);
764 index = 0;
765 path[level].bp_index = index;
766 }
767 end:
768 *ptrp = ptr;
769 ret = cnt;
770 out:
771 nilfs_btree_free_path(path);
772 return ret;
773 }
774
775 static void nilfs_btree_promote_key(struct nilfs_bmap *btree,
776 struct nilfs_btree_path *path,
777 int level, __u64 key)
778 {
779 if (level < nilfs_btree_height(btree) - 1) {
780 do {
781 nilfs_btree_node_set_key(
782 nilfs_btree_get_nonroot_node(path, level),
783 path[level].bp_index, key);
784 if (!buffer_dirty(path[level].bp_bh))
785 mark_buffer_dirty(path[level].bp_bh);
786 } while ((path[level].bp_index == 0) &&
787 (++level < nilfs_btree_height(btree) - 1));
788 }
789
790 /* root */
791 if (level == nilfs_btree_height(btree) - 1) {
792 nilfs_btree_node_set_key(nilfs_btree_get_root(btree),
793 path[level].bp_index, key);
794 }
795 }
796
797 static void nilfs_btree_do_insert(struct nilfs_bmap *btree,
798 struct nilfs_btree_path *path,
799 int level, __u64 *keyp, __u64 *ptrp)
800 {
801 struct nilfs_btree_node *node;
802 int ncblk;
803
804 if (level < nilfs_btree_height(btree) - 1) {
805 node = nilfs_btree_get_nonroot_node(path, level);
806 ncblk = nilfs_btree_nchildren_per_block(btree);
807 nilfs_btree_node_insert(node, path[level].bp_index,
808 *keyp, *ptrp, ncblk);
809 if (!buffer_dirty(path[level].bp_bh))
810 mark_buffer_dirty(path[level].bp_bh);
811
812 if (path[level].bp_index == 0)
813 nilfs_btree_promote_key(btree, path, level + 1,
814 nilfs_btree_node_get_key(node,
815 0));
816 } else {
817 node = nilfs_btree_get_root(btree);
818 nilfs_btree_node_insert(node, path[level].bp_index,
819 *keyp, *ptrp,
820 NILFS_BTREE_ROOT_NCHILDREN_MAX);
821 }
822 }
823
824 static void nilfs_btree_carry_left(struct nilfs_bmap *btree,
825 struct nilfs_btree_path *path,
826 int level, __u64 *keyp, __u64 *ptrp)
827 {
828 struct nilfs_btree_node *node, *left;
829 int nchildren, lnchildren, n, move, ncblk;
830
831 node = nilfs_btree_get_nonroot_node(path, level);
832 left = nilfs_btree_get_sib_node(path, level);
833 nchildren = nilfs_btree_node_get_nchildren(node);
834 lnchildren = nilfs_btree_node_get_nchildren(left);
835 ncblk = nilfs_btree_nchildren_per_block(btree);
836 move = 0;
837
838 n = (nchildren + lnchildren + 1) / 2 - lnchildren;
839 if (n > path[level].bp_index) {
840 /* move insert point */
841 n--;
842 move = 1;
843 }
844
845 nilfs_btree_node_move_left(left, node, n, ncblk, ncblk);
846
847 if (!buffer_dirty(path[level].bp_bh))
848 mark_buffer_dirty(path[level].bp_bh);
849 if (!buffer_dirty(path[level].bp_sib_bh))
850 mark_buffer_dirty(path[level].bp_sib_bh);
851
852 nilfs_btree_promote_key(btree, path, level + 1,
853 nilfs_btree_node_get_key(node, 0));
854
855 if (move) {
856 brelse(path[level].bp_bh);
857 path[level].bp_bh = path[level].bp_sib_bh;
858 path[level].bp_sib_bh = NULL;
859 path[level].bp_index += lnchildren;
860 path[level + 1].bp_index--;
861 } else {
862 brelse(path[level].bp_sib_bh);
863 path[level].bp_sib_bh = NULL;
864 path[level].bp_index -= n;
865 }
866
867 nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
868 }
869
870 static void nilfs_btree_carry_right(struct nilfs_bmap *btree,
871 struct nilfs_btree_path *path,
872 int level, __u64 *keyp, __u64 *ptrp)
873 {
874 struct nilfs_btree_node *node, *right;
875 int nchildren, rnchildren, n, move, ncblk;
876
877 node = nilfs_btree_get_nonroot_node(path, level);
878 right = nilfs_btree_get_sib_node(path, level);
879 nchildren = nilfs_btree_node_get_nchildren(node);
880 rnchildren = nilfs_btree_node_get_nchildren(right);
881 ncblk = nilfs_btree_nchildren_per_block(btree);
882 move = 0;
883
884 n = (nchildren + rnchildren + 1) / 2 - rnchildren;
885 if (n > nchildren - path[level].bp_index) {
886 /* move insert point */
887 n--;
888 move = 1;
889 }
890
891 nilfs_btree_node_move_right(node, right, n, ncblk, ncblk);
892
893 if (!buffer_dirty(path[level].bp_bh))
894 mark_buffer_dirty(path[level].bp_bh);
895 if (!buffer_dirty(path[level].bp_sib_bh))
896 mark_buffer_dirty(path[level].bp_sib_bh);
897
898 path[level + 1].bp_index++;
899 nilfs_btree_promote_key(btree, path, level + 1,
900 nilfs_btree_node_get_key(right, 0));
901 path[level + 1].bp_index--;
902
903 if (move) {
904 brelse(path[level].bp_bh);
905 path[level].bp_bh = path[level].bp_sib_bh;
906 path[level].bp_sib_bh = NULL;
907 path[level].bp_index -= nilfs_btree_node_get_nchildren(node);
908 path[level + 1].bp_index++;
909 } else {
910 brelse(path[level].bp_sib_bh);
911 path[level].bp_sib_bh = NULL;
912 }
913
914 nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
915 }
916
917 static void nilfs_btree_split(struct nilfs_bmap *btree,
918 struct nilfs_btree_path *path,
919 int level, __u64 *keyp, __u64 *ptrp)
920 {
921 struct nilfs_btree_node *node, *right;
922 int nchildren, n, move, ncblk;
923
924 node = nilfs_btree_get_nonroot_node(path, level);
925 right = nilfs_btree_get_sib_node(path, level);
926 nchildren = nilfs_btree_node_get_nchildren(node);
927 ncblk = nilfs_btree_nchildren_per_block(btree);
928 move = 0;
929
930 n = (nchildren + 1) / 2;
931 if (n > nchildren - path[level].bp_index) {
932 n--;
933 move = 1;
934 }
935
936 nilfs_btree_node_move_right(node, right, n, ncblk, ncblk);
937
938 if (!buffer_dirty(path[level].bp_bh))
939 mark_buffer_dirty(path[level].bp_bh);
940 if (!buffer_dirty(path[level].bp_sib_bh))
941 mark_buffer_dirty(path[level].bp_sib_bh);
942
943 if (move) {
944 path[level].bp_index -= nilfs_btree_node_get_nchildren(node);
945 nilfs_btree_node_insert(right, path[level].bp_index,
946 *keyp, *ptrp, ncblk);
947
948 *keyp = nilfs_btree_node_get_key(right, 0);
949 *ptrp = path[level].bp_newreq.bpr_ptr;
950
951 brelse(path[level].bp_bh);
952 path[level].bp_bh = path[level].bp_sib_bh;
953 path[level].bp_sib_bh = NULL;
954 } else {
955 nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
956
957 *keyp = nilfs_btree_node_get_key(right, 0);
958 *ptrp = path[level].bp_newreq.bpr_ptr;
959
960 brelse(path[level].bp_sib_bh);
961 path[level].bp_sib_bh = NULL;
962 }
963
964 path[level + 1].bp_index++;
965 }
966
967 static void nilfs_btree_grow(struct nilfs_bmap *btree,
968 struct nilfs_btree_path *path,
969 int level, __u64 *keyp, __u64 *ptrp)
970 {
971 struct nilfs_btree_node *root, *child;
972 int n, ncblk;
973
974 root = nilfs_btree_get_root(btree);
975 child = nilfs_btree_get_sib_node(path, level);
976 ncblk = nilfs_btree_nchildren_per_block(btree);
977
978 n = nilfs_btree_node_get_nchildren(root);
979
980 nilfs_btree_node_move_right(root, child, n,
981 NILFS_BTREE_ROOT_NCHILDREN_MAX, ncblk);
982 nilfs_btree_node_set_level(root, level + 1);
983
984 if (!buffer_dirty(path[level].bp_sib_bh))
985 mark_buffer_dirty(path[level].bp_sib_bh);
986
987 path[level].bp_bh = path[level].bp_sib_bh;
988 path[level].bp_sib_bh = NULL;
989
990 nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
991
992 *keyp = nilfs_btree_node_get_key(child, 0);
993 *ptrp = path[level].bp_newreq.bpr_ptr;
994 }
995
996 static __u64 nilfs_btree_find_near(const struct nilfs_bmap *btree,
997 const struct nilfs_btree_path *path)
998 {
999 struct nilfs_btree_node *node;
1000 int level, ncmax;
1001
1002 if (path == NULL)
1003 return NILFS_BMAP_INVALID_PTR;
1004
1005 /* left sibling */
1006 level = NILFS_BTREE_LEVEL_NODE_MIN;
1007 if (path[level].bp_index > 0) {
1008 node = nilfs_btree_get_node(btree, path, level, &ncmax);
1009 return nilfs_btree_node_get_ptr(node,
1010 path[level].bp_index - 1,
1011 ncmax);
1012 }
1013
1014 /* parent */
1015 level = NILFS_BTREE_LEVEL_NODE_MIN + 1;
1016 if (level <= nilfs_btree_height(btree) - 1) {
1017 node = nilfs_btree_get_node(btree, path, level, &ncmax);
1018 return nilfs_btree_node_get_ptr(node, path[level].bp_index,
1019 ncmax);
1020 }
1021
1022 return NILFS_BMAP_INVALID_PTR;
1023 }
1024
1025 static __u64 nilfs_btree_find_target_v(const struct nilfs_bmap *btree,
1026 const struct nilfs_btree_path *path,
1027 __u64 key)
1028 {
1029 __u64 ptr;
1030
1031 ptr = nilfs_bmap_find_target_seq(btree, key);
1032 if (ptr != NILFS_BMAP_INVALID_PTR)
1033 /* sequential access */
1034 return ptr;
1035 else {
1036 ptr = nilfs_btree_find_near(btree, path);
1037 if (ptr != NILFS_BMAP_INVALID_PTR)
1038 /* near */
1039 return ptr;
1040 }
1041 /* block group */
1042 return nilfs_bmap_find_target_in_group(btree);
1043 }
1044
1045 static int nilfs_btree_prepare_insert(struct nilfs_bmap *btree,
1046 struct nilfs_btree_path *path,
1047 int *levelp, __u64 key, __u64 ptr,
1048 struct nilfs_bmap_stats *stats)
1049 {
1050 struct buffer_head *bh;
1051 struct nilfs_btree_node *node, *parent, *sib;
1052 __u64 sibptr;
1053 int pindex, level, ncmax, ncblk, ret;
1054 struct inode *dat = NULL;
1055
1056 stats->bs_nblocks = 0;
1057 level = NILFS_BTREE_LEVEL_DATA;
1058
1059 /* allocate a new ptr for data block */
1060 if (NILFS_BMAP_USE_VBN(btree)) {
1061 path[level].bp_newreq.bpr_ptr =
1062 nilfs_btree_find_target_v(btree, path, key);
1063 dat = nilfs_bmap_get_dat(btree);
1064 }
1065
1066 ret = nilfs_bmap_prepare_alloc_ptr(btree, &path[level].bp_newreq, dat);
1067 if (ret < 0)
1068 goto err_out_data;
1069
1070 ncblk = nilfs_btree_nchildren_per_block(btree);
1071
1072 for (level = NILFS_BTREE_LEVEL_NODE_MIN;
1073 level < nilfs_btree_height(btree) - 1;
1074 level++) {
1075 node = nilfs_btree_get_nonroot_node(path, level);
1076 if (nilfs_btree_node_get_nchildren(node) < ncblk) {
1077 path[level].bp_op = nilfs_btree_do_insert;
1078 stats->bs_nblocks++;
1079 goto out;
1080 }
1081
1082 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
1083 pindex = path[level + 1].bp_index;
1084
1085 /* left sibling */
1086 if (pindex > 0) {
1087 sibptr = nilfs_btree_node_get_ptr(parent, pindex - 1,
1088 ncmax);
1089 ret = nilfs_btree_get_block(btree, sibptr, &bh);
1090 if (ret < 0)
1091 goto err_out_child_node;
1092 sib = (struct nilfs_btree_node *)bh->b_data;
1093 if (nilfs_btree_node_get_nchildren(sib) < ncblk) {
1094 path[level].bp_sib_bh = bh;
1095 path[level].bp_op = nilfs_btree_carry_left;
1096 stats->bs_nblocks++;
1097 goto out;
1098 } else {
1099 brelse(bh);
1100 }
1101 }
1102
1103 /* right sibling */
1104 if (pindex < nilfs_btree_node_get_nchildren(parent) - 1) {
1105 sibptr = nilfs_btree_node_get_ptr(parent, pindex + 1,
1106 ncmax);
1107 ret = nilfs_btree_get_block(btree, sibptr, &bh);
1108 if (ret < 0)
1109 goto err_out_child_node;
1110 sib = (struct nilfs_btree_node *)bh->b_data;
1111 if (nilfs_btree_node_get_nchildren(sib) < ncblk) {
1112 path[level].bp_sib_bh = bh;
1113 path[level].bp_op = nilfs_btree_carry_right;
1114 stats->bs_nblocks++;
1115 goto out;
1116 } else {
1117 brelse(bh);
1118 }
1119 }
1120
1121 /* split */
1122 path[level].bp_newreq.bpr_ptr =
1123 path[level - 1].bp_newreq.bpr_ptr + 1;
1124 ret = nilfs_bmap_prepare_alloc_ptr(btree,
1125 &path[level].bp_newreq, dat);
1126 if (ret < 0)
1127 goto err_out_child_node;
1128 ret = nilfs_btree_get_new_block(btree,
1129 path[level].bp_newreq.bpr_ptr,
1130 &bh);
1131 if (ret < 0)
1132 goto err_out_curr_node;
1133
1134 stats->bs_nblocks++;
1135
1136 sib = (struct nilfs_btree_node *)bh->b_data;
1137 nilfs_btree_node_init(sib, 0, level, 0, ncblk, NULL, NULL);
1138 path[level].bp_sib_bh = bh;
1139 path[level].bp_op = nilfs_btree_split;
1140 }
1141
1142 /* root */
1143 node = nilfs_btree_get_root(btree);
1144 if (nilfs_btree_node_get_nchildren(node) <
1145 NILFS_BTREE_ROOT_NCHILDREN_MAX) {
1146 path[level].bp_op = nilfs_btree_do_insert;
1147 stats->bs_nblocks++;
1148 goto out;
1149 }
1150
1151 /* grow */
1152 path[level].bp_newreq.bpr_ptr = path[level - 1].bp_newreq.bpr_ptr + 1;
1153 ret = nilfs_bmap_prepare_alloc_ptr(btree, &path[level].bp_newreq, dat);
1154 if (ret < 0)
1155 goto err_out_child_node;
1156 ret = nilfs_btree_get_new_block(btree, path[level].bp_newreq.bpr_ptr,
1157 &bh);
1158 if (ret < 0)
1159 goto err_out_curr_node;
1160
1161 nilfs_btree_node_init((struct nilfs_btree_node *)bh->b_data,
1162 0, level, 0, ncblk, NULL, NULL);
1163 path[level].bp_sib_bh = bh;
1164 path[level].bp_op = nilfs_btree_grow;
1165
1166 level++;
1167 path[level].bp_op = nilfs_btree_do_insert;
1168
1169 /* a newly-created node block and a data block are added */
1170 stats->bs_nblocks += 2;
1171
1172 /* success */
1173 out:
1174 *levelp = level;
1175 return ret;
1176
1177 /* error */
1178 err_out_curr_node:
1179 nilfs_bmap_abort_alloc_ptr(btree, &path[level].bp_newreq, dat);
1180 err_out_child_node:
1181 for (level--; level > NILFS_BTREE_LEVEL_DATA; level--) {
1182 nilfs_btnode_delete(path[level].bp_sib_bh);
1183 nilfs_bmap_abort_alloc_ptr(btree, &path[level].bp_newreq, dat);
1184
1185 }
1186
1187 nilfs_bmap_abort_alloc_ptr(btree, &path[level].bp_newreq, dat);
1188 err_out_data:
1189 *levelp = level;
1190 stats->bs_nblocks = 0;
1191 return ret;
1192 }
1193
1194 static void nilfs_btree_commit_insert(struct nilfs_bmap *btree,
1195 struct nilfs_btree_path *path,
1196 int maxlevel, __u64 key, __u64 ptr)
1197 {
1198 struct inode *dat = NULL;
1199 int level;
1200
1201 set_buffer_nilfs_volatile((struct buffer_head *)((unsigned long)ptr));
1202 ptr = path[NILFS_BTREE_LEVEL_DATA].bp_newreq.bpr_ptr;
1203 if (NILFS_BMAP_USE_VBN(btree)) {
1204 nilfs_bmap_set_target_v(btree, key, ptr);
1205 dat = nilfs_bmap_get_dat(btree);
1206 }
1207
1208 for (level = NILFS_BTREE_LEVEL_NODE_MIN; level <= maxlevel; level++) {
1209 nilfs_bmap_commit_alloc_ptr(btree,
1210 &path[level - 1].bp_newreq, dat);
1211 path[level].bp_op(btree, path, level, &key, &ptr);
1212 }
1213
1214 if (!nilfs_bmap_dirty(btree))
1215 nilfs_bmap_set_dirty(btree);
1216 }
1217
1218 static int nilfs_btree_insert(struct nilfs_bmap *btree, __u64 key, __u64 ptr)
1219 {
1220 struct nilfs_btree_path *path;
1221 struct nilfs_bmap_stats stats;
1222 int level, ret;
1223
1224 path = nilfs_btree_alloc_path();
1225 if (path == NULL)
1226 return -ENOMEM;
1227
1228 ret = nilfs_btree_do_lookup(btree, path, key, NULL,
1229 NILFS_BTREE_LEVEL_NODE_MIN, 0);
1230 if (ret != -ENOENT) {
1231 if (ret == 0)
1232 ret = -EEXIST;
1233 goto out;
1234 }
1235
1236 ret = nilfs_btree_prepare_insert(btree, path, &level, key, ptr, &stats);
1237 if (ret < 0)
1238 goto out;
1239 nilfs_btree_commit_insert(btree, path, level, key, ptr);
1240 nilfs_inode_add_blocks(btree->b_inode, stats.bs_nblocks);
1241
1242 out:
1243 nilfs_btree_free_path(path);
1244 return ret;
1245 }
1246
1247 static void nilfs_btree_do_delete(struct nilfs_bmap *btree,
1248 struct nilfs_btree_path *path,
1249 int level, __u64 *keyp, __u64 *ptrp)
1250 {
1251 struct nilfs_btree_node *node;
1252 int ncblk;
1253
1254 if (level < nilfs_btree_height(btree) - 1) {
1255 node = nilfs_btree_get_nonroot_node(path, level);
1256 ncblk = nilfs_btree_nchildren_per_block(btree);
1257 nilfs_btree_node_delete(node, path[level].bp_index,
1258 keyp, ptrp, ncblk);
1259 if (!buffer_dirty(path[level].bp_bh))
1260 mark_buffer_dirty(path[level].bp_bh);
1261 if (path[level].bp_index == 0)
1262 nilfs_btree_promote_key(btree, path, level + 1,
1263 nilfs_btree_node_get_key(node, 0));
1264 } else {
1265 node = nilfs_btree_get_root(btree);
1266 nilfs_btree_node_delete(node, path[level].bp_index,
1267 keyp, ptrp,
1268 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1269 }
1270 }
1271
1272 static void nilfs_btree_borrow_left(struct nilfs_bmap *btree,
1273 struct nilfs_btree_path *path,
1274 int level, __u64 *keyp, __u64 *ptrp)
1275 {
1276 struct nilfs_btree_node *node, *left;
1277 int nchildren, lnchildren, n, ncblk;
1278
1279 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1280
1281 node = nilfs_btree_get_nonroot_node(path, level);
1282 left = nilfs_btree_get_sib_node(path, level);
1283 nchildren = nilfs_btree_node_get_nchildren(node);
1284 lnchildren = nilfs_btree_node_get_nchildren(left);
1285 ncblk = nilfs_btree_nchildren_per_block(btree);
1286
1287 n = (nchildren + lnchildren) / 2 - nchildren;
1288
1289 nilfs_btree_node_move_right(left, node, n, ncblk, ncblk);
1290
1291 if (!buffer_dirty(path[level].bp_bh))
1292 mark_buffer_dirty(path[level].bp_bh);
1293 if (!buffer_dirty(path[level].bp_sib_bh))
1294 mark_buffer_dirty(path[level].bp_sib_bh);
1295
1296 nilfs_btree_promote_key(btree, path, level + 1,
1297 nilfs_btree_node_get_key(node, 0));
1298
1299 brelse(path[level].bp_sib_bh);
1300 path[level].bp_sib_bh = NULL;
1301 path[level].bp_index += n;
1302 }
1303
1304 static void nilfs_btree_borrow_right(struct nilfs_bmap *btree,
1305 struct nilfs_btree_path *path,
1306 int level, __u64 *keyp, __u64 *ptrp)
1307 {
1308 struct nilfs_btree_node *node, *right;
1309 int nchildren, rnchildren, n, ncblk;
1310
1311 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1312
1313 node = nilfs_btree_get_nonroot_node(path, level);
1314 right = nilfs_btree_get_sib_node(path, level);
1315 nchildren = nilfs_btree_node_get_nchildren(node);
1316 rnchildren = nilfs_btree_node_get_nchildren(right);
1317 ncblk = nilfs_btree_nchildren_per_block(btree);
1318
1319 n = (nchildren + rnchildren) / 2 - nchildren;
1320
1321 nilfs_btree_node_move_left(node, right, n, ncblk, ncblk);
1322
1323 if (!buffer_dirty(path[level].bp_bh))
1324 mark_buffer_dirty(path[level].bp_bh);
1325 if (!buffer_dirty(path[level].bp_sib_bh))
1326 mark_buffer_dirty(path[level].bp_sib_bh);
1327
1328 path[level + 1].bp_index++;
1329 nilfs_btree_promote_key(btree, path, level + 1,
1330 nilfs_btree_node_get_key(right, 0));
1331 path[level + 1].bp_index--;
1332
1333 brelse(path[level].bp_sib_bh);
1334 path[level].bp_sib_bh = NULL;
1335 }
1336
1337 static void nilfs_btree_concat_left(struct nilfs_bmap *btree,
1338 struct nilfs_btree_path *path,
1339 int level, __u64 *keyp, __u64 *ptrp)
1340 {
1341 struct nilfs_btree_node *node, *left;
1342 int n, ncblk;
1343
1344 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1345
1346 node = nilfs_btree_get_nonroot_node(path, level);
1347 left = nilfs_btree_get_sib_node(path, level);
1348 ncblk = nilfs_btree_nchildren_per_block(btree);
1349
1350 n = nilfs_btree_node_get_nchildren(node);
1351
1352 nilfs_btree_node_move_left(left, node, n, ncblk, ncblk);
1353
1354 if (!buffer_dirty(path[level].bp_sib_bh))
1355 mark_buffer_dirty(path[level].bp_sib_bh);
1356
1357 nilfs_btnode_delete(path[level].bp_bh);
1358 path[level].bp_bh = path[level].bp_sib_bh;
1359 path[level].bp_sib_bh = NULL;
1360 path[level].bp_index += nilfs_btree_node_get_nchildren(left);
1361 }
1362
1363 static void nilfs_btree_concat_right(struct nilfs_bmap *btree,
1364 struct nilfs_btree_path *path,
1365 int level, __u64 *keyp, __u64 *ptrp)
1366 {
1367 struct nilfs_btree_node *node, *right;
1368 int n, ncblk;
1369
1370 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1371
1372 node = nilfs_btree_get_nonroot_node(path, level);
1373 right = nilfs_btree_get_sib_node(path, level);
1374 ncblk = nilfs_btree_nchildren_per_block(btree);
1375
1376 n = nilfs_btree_node_get_nchildren(right);
1377
1378 nilfs_btree_node_move_left(node, right, n, ncblk, ncblk);
1379
1380 if (!buffer_dirty(path[level].bp_bh))
1381 mark_buffer_dirty(path[level].bp_bh);
1382
1383 nilfs_btnode_delete(path[level].bp_sib_bh);
1384 path[level].bp_sib_bh = NULL;
1385 path[level + 1].bp_index++;
1386 }
1387
1388 static void nilfs_btree_shrink(struct nilfs_bmap *btree,
1389 struct nilfs_btree_path *path,
1390 int level, __u64 *keyp, __u64 *ptrp)
1391 {
1392 struct nilfs_btree_node *root, *child;
1393 int n, ncblk;
1394
1395 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1396
1397 root = nilfs_btree_get_root(btree);
1398 child = nilfs_btree_get_nonroot_node(path, level);
1399 ncblk = nilfs_btree_nchildren_per_block(btree);
1400
1401 nilfs_btree_node_delete(root, 0, NULL, NULL,
1402 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1403 nilfs_btree_node_set_level(root, level);
1404 n = nilfs_btree_node_get_nchildren(child);
1405 nilfs_btree_node_move_left(root, child, n,
1406 NILFS_BTREE_ROOT_NCHILDREN_MAX, ncblk);
1407
1408 nilfs_btnode_delete(path[level].bp_bh);
1409 path[level].bp_bh = NULL;
1410 }
1411
1412 static void nilfs_btree_nop(struct nilfs_bmap *btree,
1413 struct nilfs_btree_path *path,
1414 int level, __u64 *keyp, __u64 *ptrp)
1415 {
1416 }
1417
1418 static int nilfs_btree_prepare_delete(struct nilfs_bmap *btree,
1419 struct nilfs_btree_path *path,
1420 int *levelp,
1421 struct nilfs_bmap_stats *stats,
1422 struct inode *dat)
1423 {
1424 struct buffer_head *bh;
1425 struct nilfs_btree_node *node, *parent, *sib;
1426 __u64 sibptr;
1427 int pindex, dindex, level, ncmin, ncmax, ncblk, ret;
1428
1429 ret = 0;
1430 stats->bs_nblocks = 0;
1431 ncmin = NILFS_BTREE_NODE_NCHILDREN_MIN(nilfs_btree_node_size(btree));
1432 ncblk = nilfs_btree_nchildren_per_block(btree);
1433
1434 for (level = NILFS_BTREE_LEVEL_NODE_MIN, dindex = path[level].bp_index;
1435 level < nilfs_btree_height(btree) - 1;
1436 level++) {
1437 node = nilfs_btree_get_nonroot_node(path, level);
1438 path[level].bp_oldreq.bpr_ptr =
1439 nilfs_btree_node_get_ptr(node, dindex, ncblk);
1440 ret = nilfs_bmap_prepare_end_ptr(btree,
1441 &path[level].bp_oldreq, dat);
1442 if (ret < 0)
1443 goto err_out_child_node;
1444
1445 if (nilfs_btree_node_get_nchildren(node) > ncmin) {
1446 path[level].bp_op = nilfs_btree_do_delete;
1447 stats->bs_nblocks++;
1448 goto out;
1449 }
1450
1451 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
1452 pindex = path[level + 1].bp_index;
1453 dindex = pindex;
1454
1455 if (pindex > 0) {
1456 /* left sibling */
1457 sibptr = nilfs_btree_node_get_ptr(parent, pindex - 1,
1458 ncmax);
1459 ret = nilfs_btree_get_block(btree, sibptr, &bh);
1460 if (ret < 0)
1461 goto err_out_curr_node;
1462 sib = (struct nilfs_btree_node *)bh->b_data;
1463 if (nilfs_btree_node_get_nchildren(sib) > ncmin) {
1464 path[level].bp_sib_bh = bh;
1465 path[level].bp_op = nilfs_btree_borrow_left;
1466 stats->bs_nblocks++;
1467 goto out;
1468 } else {
1469 path[level].bp_sib_bh = bh;
1470 path[level].bp_op = nilfs_btree_concat_left;
1471 stats->bs_nblocks++;
1472 /* continue; */
1473 }
1474 } else if (pindex <
1475 nilfs_btree_node_get_nchildren(parent) - 1) {
1476 /* right sibling */
1477 sibptr = nilfs_btree_node_get_ptr(parent, pindex + 1,
1478 ncmax);
1479 ret = nilfs_btree_get_block(btree, sibptr, &bh);
1480 if (ret < 0)
1481 goto err_out_curr_node;
1482 sib = (struct nilfs_btree_node *)bh->b_data;
1483 if (nilfs_btree_node_get_nchildren(sib) > ncmin) {
1484 path[level].bp_sib_bh = bh;
1485 path[level].bp_op = nilfs_btree_borrow_right;
1486 stats->bs_nblocks++;
1487 goto out;
1488 } else {
1489 path[level].bp_sib_bh = bh;
1490 path[level].bp_op = nilfs_btree_concat_right;
1491 stats->bs_nblocks++;
1492 /*
1493 * When merging right sibling node
1494 * into the current node, pointer to
1495 * the right sibling node must be
1496 * terminated instead. The adjustment
1497 * below is required for that.
1498 */
1499 dindex = pindex + 1;
1500 /* continue; */
1501 }
1502 } else {
1503 /* no siblings */
1504 /* the only child of the root node */
1505 WARN_ON(level != nilfs_btree_height(btree) - 2);
1506 if (nilfs_btree_node_get_nchildren(node) - 1 <=
1507 NILFS_BTREE_ROOT_NCHILDREN_MAX) {
1508 path[level].bp_op = nilfs_btree_shrink;
1509 stats->bs_nblocks += 2;
1510 level++;
1511 path[level].bp_op = nilfs_btree_nop;
1512 goto shrink_root_child;
1513 } else {
1514 path[level].bp_op = nilfs_btree_do_delete;
1515 stats->bs_nblocks++;
1516 goto out;
1517 }
1518 }
1519 }
1520
1521 /* child of the root node is deleted */
1522 path[level].bp_op = nilfs_btree_do_delete;
1523 stats->bs_nblocks++;
1524
1525 shrink_root_child:
1526 node = nilfs_btree_get_root(btree);
1527 path[level].bp_oldreq.bpr_ptr =
1528 nilfs_btree_node_get_ptr(node, dindex,
1529 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1530
1531 ret = nilfs_bmap_prepare_end_ptr(btree, &path[level].bp_oldreq, dat);
1532 if (ret < 0)
1533 goto err_out_child_node;
1534
1535 /* success */
1536 out:
1537 *levelp = level;
1538 return ret;
1539
1540 /* error */
1541 err_out_curr_node:
1542 nilfs_bmap_abort_end_ptr(btree, &path[level].bp_oldreq, dat);
1543 err_out_child_node:
1544 for (level--; level >= NILFS_BTREE_LEVEL_NODE_MIN; level--) {
1545 brelse(path[level].bp_sib_bh);
1546 nilfs_bmap_abort_end_ptr(btree, &path[level].bp_oldreq, dat);
1547 }
1548 *levelp = level;
1549 stats->bs_nblocks = 0;
1550 return ret;
1551 }
1552
1553 static void nilfs_btree_commit_delete(struct nilfs_bmap *btree,
1554 struct nilfs_btree_path *path,
1555 int maxlevel, struct inode *dat)
1556 {
1557 int level;
1558
1559 for (level = NILFS_BTREE_LEVEL_NODE_MIN; level <= maxlevel; level++) {
1560 nilfs_bmap_commit_end_ptr(btree, &path[level].bp_oldreq, dat);
1561 path[level].bp_op(btree, path, level, NULL, NULL);
1562 }
1563
1564 if (!nilfs_bmap_dirty(btree))
1565 nilfs_bmap_set_dirty(btree);
1566 }
1567
1568 static int nilfs_btree_delete(struct nilfs_bmap *btree, __u64 key)
1569
1570 {
1571 struct nilfs_btree_path *path;
1572 struct nilfs_bmap_stats stats;
1573 struct inode *dat;
1574 int level, ret;
1575
1576 path = nilfs_btree_alloc_path();
1577 if (path == NULL)
1578 return -ENOMEM;
1579
1580 ret = nilfs_btree_do_lookup(btree, path, key, NULL,
1581 NILFS_BTREE_LEVEL_NODE_MIN, 0);
1582 if (ret < 0)
1583 goto out;
1584
1585
1586 dat = NILFS_BMAP_USE_VBN(btree) ? nilfs_bmap_get_dat(btree) : NULL;
1587
1588 ret = nilfs_btree_prepare_delete(btree, path, &level, &stats, dat);
1589 if (ret < 0)
1590 goto out;
1591 nilfs_btree_commit_delete(btree, path, level, dat);
1592 nilfs_inode_sub_blocks(btree->b_inode, stats.bs_nblocks);
1593
1594 out:
1595 nilfs_btree_free_path(path);
1596 return ret;
1597 }
1598
1599 static int nilfs_btree_seek_key(const struct nilfs_bmap *btree, __u64 start,
1600 __u64 *keyp)
1601 {
1602 struct nilfs_btree_path *path;
1603 const int minlevel = NILFS_BTREE_LEVEL_NODE_MIN;
1604 int ret;
1605
1606 path = nilfs_btree_alloc_path();
1607 if (!path)
1608 return -ENOMEM;
1609
1610 ret = nilfs_btree_do_lookup(btree, path, start, NULL, minlevel, 0);
1611 if (!ret)
1612 *keyp = start;
1613 else if (ret == -ENOENT)
1614 ret = nilfs_btree_get_next_key(btree, path, minlevel, keyp);
1615
1616 nilfs_btree_free_path(path);
1617 return ret;
1618 }
1619
1620 static int nilfs_btree_last_key(const struct nilfs_bmap *btree, __u64 *keyp)
1621 {
1622 struct nilfs_btree_path *path;
1623 int ret;
1624
1625 path = nilfs_btree_alloc_path();
1626 if (path == NULL)
1627 return -ENOMEM;
1628
1629 ret = nilfs_btree_do_lookup_last(btree, path, keyp, NULL);
1630
1631 nilfs_btree_free_path(path);
1632
1633 return ret;
1634 }
1635
1636 static int nilfs_btree_check_delete(struct nilfs_bmap *btree, __u64 key)
1637 {
1638 struct buffer_head *bh;
1639 struct nilfs_btree_node *root, *node;
1640 __u64 maxkey, nextmaxkey;
1641 __u64 ptr;
1642 int nchildren, ret;
1643
1644 root = nilfs_btree_get_root(btree);
1645 switch (nilfs_btree_height(btree)) {
1646 case 2:
1647 bh = NULL;
1648 node = root;
1649 break;
1650 case 3:
1651 nchildren = nilfs_btree_node_get_nchildren(root);
1652 if (nchildren > 1)
1653 return 0;
1654 ptr = nilfs_btree_node_get_ptr(root, nchildren - 1,
1655 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1656 ret = nilfs_btree_get_block(btree, ptr, &bh);
1657 if (ret < 0)
1658 return ret;
1659 node = (struct nilfs_btree_node *)bh->b_data;
1660 break;
1661 default:
1662 return 0;
1663 }
1664
1665 nchildren = nilfs_btree_node_get_nchildren(node);
1666 maxkey = nilfs_btree_node_get_key(node, nchildren - 1);
1667 nextmaxkey = (nchildren > 1) ?
1668 nilfs_btree_node_get_key(node, nchildren - 2) : 0;
1669 if (bh != NULL)
1670 brelse(bh);
1671
1672 return (maxkey == key) && (nextmaxkey < NILFS_BMAP_LARGE_LOW);
1673 }
1674
1675 static int nilfs_btree_gather_data(struct nilfs_bmap *btree,
1676 __u64 *keys, __u64 *ptrs, int nitems)
1677 {
1678 struct buffer_head *bh;
1679 struct nilfs_btree_node *node, *root;
1680 __le64 *dkeys;
1681 __le64 *dptrs;
1682 __u64 ptr;
1683 int nchildren, ncmax, i, ret;
1684
1685 root = nilfs_btree_get_root(btree);
1686 switch (nilfs_btree_height(btree)) {
1687 case 2:
1688 bh = NULL;
1689 node = root;
1690 ncmax = NILFS_BTREE_ROOT_NCHILDREN_MAX;
1691 break;
1692 case 3:
1693 nchildren = nilfs_btree_node_get_nchildren(root);
1694 WARN_ON(nchildren > 1);
1695 ptr = nilfs_btree_node_get_ptr(root, nchildren - 1,
1696 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1697 ret = nilfs_btree_get_block(btree, ptr, &bh);
1698 if (ret < 0)
1699 return ret;
1700 node = (struct nilfs_btree_node *)bh->b_data;
1701 ncmax = nilfs_btree_nchildren_per_block(btree);
1702 break;
1703 default:
1704 node = NULL;
1705 return -EINVAL;
1706 }
1707
1708 nchildren = nilfs_btree_node_get_nchildren(node);
1709 if (nchildren < nitems)
1710 nitems = nchildren;
1711 dkeys = nilfs_btree_node_dkeys(node);
1712 dptrs = nilfs_btree_node_dptrs(node, ncmax);
1713 for (i = 0; i < nitems; i++) {
1714 keys[i] = le64_to_cpu(dkeys[i]);
1715 ptrs[i] = le64_to_cpu(dptrs[i]);
1716 }
1717
1718 if (bh != NULL)
1719 brelse(bh);
1720
1721 return nitems;
1722 }
1723
1724 static int
1725 nilfs_btree_prepare_convert_and_insert(struct nilfs_bmap *btree, __u64 key,
1726 union nilfs_bmap_ptr_req *dreq,
1727 union nilfs_bmap_ptr_req *nreq,
1728 struct buffer_head **bhp,
1729 struct nilfs_bmap_stats *stats)
1730 {
1731 struct buffer_head *bh;
1732 struct inode *dat = NULL;
1733 int ret;
1734
1735 stats->bs_nblocks = 0;
1736
1737 /* for data */
1738 /* cannot find near ptr */
1739 if (NILFS_BMAP_USE_VBN(btree)) {
1740 dreq->bpr_ptr = nilfs_btree_find_target_v(btree, NULL, key);
1741 dat = nilfs_bmap_get_dat(btree);
1742 }
1743
1744 ret = nilfs_bmap_prepare_alloc_ptr(btree, dreq, dat);
1745 if (ret < 0)
1746 return ret;
1747
1748 *bhp = NULL;
1749 stats->bs_nblocks++;
1750 if (nreq != NULL) {
1751 nreq->bpr_ptr = dreq->bpr_ptr + 1;
1752 ret = nilfs_bmap_prepare_alloc_ptr(btree, nreq, dat);
1753 if (ret < 0)
1754 goto err_out_dreq;
1755
1756 ret = nilfs_btree_get_new_block(btree, nreq->bpr_ptr, &bh);
1757 if (ret < 0)
1758 goto err_out_nreq;
1759
1760 *bhp = bh;
1761 stats->bs_nblocks++;
1762 }
1763
1764 /* success */
1765 return 0;
1766
1767 /* error */
1768 err_out_nreq:
1769 nilfs_bmap_abort_alloc_ptr(btree, nreq, dat);
1770 err_out_dreq:
1771 nilfs_bmap_abort_alloc_ptr(btree, dreq, dat);
1772 stats->bs_nblocks = 0;
1773 return ret;
1774
1775 }
1776
1777 static void
1778 nilfs_btree_commit_convert_and_insert(struct nilfs_bmap *btree,
1779 __u64 key, __u64 ptr,
1780 const __u64 *keys, const __u64 *ptrs,
1781 int n,
1782 union nilfs_bmap_ptr_req *dreq,
1783 union nilfs_bmap_ptr_req *nreq,
1784 struct buffer_head *bh)
1785 {
1786 struct nilfs_btree_node *node;
1787 struct inode *dat;
1788 __u64 tmpptr;
1789 int ncblk;
1790
1791 /* free resources */
1792 if (btree->b_ops->bop_clear != NULL)
1793 btree->b_ops->bop_clear(btree);
1794
1795 /* ptr must be a pointer to a buffer head. */
1796 set_buffer_nilfs_volatile((struct buffer_head *)((unsigned long)ptr));
1797
1798 /* convert and insert */
1799 dat = NILFS_BMAP_USE_VBN(btree) ? nilfs_bmap_get_dat(btree) : NULL;
1800 __nilfs_btree_init(btree);
1801 if (nreq != NULL) {
1802 nilfs_bmap_commit_alloc_ptr(btree, dreq, dat);
1803 nilfs_bmap_commit_alloc_ptr(btree, nreq, dat);
1804
1805 /* create child node at level 1 */
1806 node = (struct nilfs_btree_node *)bh->b_data;
1807 ncblk = nilfs_btree_nchildren_per_block(btree);
1808 nilfs_btree_node_init(node, 0, 1, n, ncblk, keys, ptrs);
1809 nilfs_btree_node_insert(node, n, key, dreq->bpr_ptr, ncblk);
1810 if (!buffer_dirty(bh))
1811 mark_buffer_dirty(bh);
1812 if (!nilfs_bmap_dirty(btree))
1813 nilfs_bmap_set_dirty(btree);
1814
1815 brelse(bh);
1816
1817 /* create root node at level 2 */
1818 node = nilfs_btree_get_root(btree);
1819 tmpptr = nreq->bpr_ptr;
1820 nilfs_btree_node_init(node, NILFS_BTREE_NODE_ROOT, 2, 1,
1821 NILFS_BTREE_ROOT_NCHILDREN_MAX,
1822 &keys[0], &tmpptr);
1823 } else {
1824 nilfs_bmap_commit_alloc_ptr(btree, dreq, dat);
1825
1826 /* create root node at level 1 */
1827 node = nilfs_btree_get_root(btree);
1828 nilfs_btree_node_init(node, NILFS_BTREE_NODE_ROOT, 1, n,
1829 NILFS_BTREE_ROOT_NCHILDREN_MAX,
1830 keys, ptrs);
1831 nilfs_btree_node_insert(node, n, key, dreq->bpr_ptr,
1832 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1833 if (!nilfs_bmap_dirty(btree))
1834 nilfs_bmap_set_dirty(btree);
1835 }
1836
1837 if (NILFS_BMAP_USE_VBN(btree))
1838 nilfs_bmap_set_target_v(btree, key, dreq->bpr_ptr);
1839 }
1840
1841 /**
1842 * nilfs_btree_convert_and_insert -
1843 * @bmap:
1844 * @key:
1845 * @ptr:
1846 * @keys:
1847 * @ptrs:
1848 * @n:
1849 */
1850 int nilfs_btree_convert_and_insert(struct nilfs_bmap *btree,
1851 __u64 key, __u64 ptr,
1852 const __u64 *keys, const __u64 *ptrs, int n)
1853 {
1854 struct buffer_head *bh = NULL;
1855 union nilfs_bmap_ptr_req dreq, nreq, *di, *ni;
1856 struct nilfs_bmap_stats stats;
1857 int ret;
1858
1859 if (n + 1 <= NILFS_BTREE_ROOT_NCHILDREN_MAX) {
1860 di = &dreq;
1861 ni = NULL;
1862 } else if ((n + 1) <= NILFS_BTREE_NODE_NCHILDREN_MAX(
1863 1 << btree->b_inode->i_blkbits)) {
1864 di = &dreq;
1865 ni = &nreq;
1866 } else {
1867 di = NULL;
1868 ni = NULL;
1869 BUG();
1870 }
1871
1872 ret = nilfs_btree_prepare_convert_and_insert(btree, key, di, ni, &bh,
1873 &stats);
1874 if (ret < 0)
1875 return ret;
1876 nilfs_btree_commit_convert_and_insert(btree, key, ptr, keys, ptrs, n,
1877 di, ni, bh);
1878 nilfs_inode_add_blocks(btree->b_inode, stats.bs_nblocks);
1879 return 0;
1880 }
1881
1882 static int nilfs_btree_propagate_p(struct nilfs_bmap *btree,
1883 struct nilfs_btree_path *path,
1884 int level,
1885 struct buffer_head *bh)
1886 {
1887 while ((++level < nilfs_btree_height(btree) - 1) &&
1888 !buffer_dirty(path[level].bp_bh))
1889 mark_buffer_dirty(path[level].bp_bh);
1890
1891 return 0;
1892 }
1893
1894 static int nilfs_btree_prepare_update_v(struct nilfs_bmap *btree,
1895 struct nilfs_btree_path *path,
1896 int level, struct inode *dat)
1897 {
1898 struct nilfs_btree_node *parent;
1899 int ncmax, ret;
1900
1901 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
1902 path[level].bp_oldreq.bpr_ptr =
1903 nilfs_btree_node_get_ptr(parent, path[level + 1].bp_index,
1904 ncmax);
1905 path[level].bp_newreq.bpr_ptr = path[level].bp_oldreq.bpr_ptr + 1;
1906 ret = nilfs_dat_prepare_update(dat, &path[level].bp_oldreq.bpr_req,
1907 &path[level].bp_newreq.bpr_req);
1908 if (ret < 0)
1909 return ret;
1910
1911 if (buffer_nilfs_node(path[level].bp_bh)) {
1912 path[level].bp_ctxt.oldkey = path[level].bp_oldreq.bpr_ptr;
1913 path[level].bp_ctxt.newkey = path[level].bp_newreq.bpr_ptr;
1914 path[level].bp_ctxt.bh = path[level].bp_bh;
1915 ret = nilfs_btnode_prepare_change_key(
1916 &NILFS_BMAP_I(btree)->i_btnode_cache,
1917 &path[level].bp_ctxt);
1918 if (ret < 0) {
1919 nilfs_dat_abort_update(dat,
1920 &path[level].bp_oldreq.bpr_req,
1921 &path[level].bp_newreq.bpr_req);
1922 return ret;
1923 }
1924 }
1925
1926 return 0;
1927 }
1928
1929 static void nilfs_btree_commit_update_v(struct nilfs_bmap *btree,
1930 struct nilfs_btree_path *path,
1931 int level, struct inode *dat)
1932 {
1933 struct nilfs_btree_node *parent;
1934 int ncmax;
1935
1936 nilfs_dat_commit_update(dat, &path[level].bp_oldreq.bpr_req,
1937 &path[level].bp_newreq.bpr_req,
1938 btree->b_ptr_type == NILFS_BMAP_PTR_VS);
1939
1940 if (buffer_nilfs_node(path[level].bp_bh)) {
1941 nilfs_btnode_commit_change_key(
1942 &NILFS_BMAP_I(btree)->i_btnode_cache,
1943 &path[level].bp_ctxt);
1944 path[level].bp_bh = path[level].bp_ctxt.bh;
1945 }
1946 set_buffer_nilfs_volatile(path[level].bp_bh);
1947
1948 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
1949 nilfs_btree_node_set_ptr(parent, path[level + 1].bp_index,
1950 path[level].bp_newreq.bpr_ptr, ncmax);
1951 }
1952
1953 static void nilfs_btree_abort_update_v(struct nilfs_bmap *btree,
1954 struct nilfs_btree_path *path,
1955 int level, struct inode *dat)
1956 {
1957 nilfs_dat_abort_update(dat, &path[level].bp_oldreq.bpr_req,
1958 &path[level].bp_newreq.bpr_req);
1959 if (buffer_nilfs_node(path[level].bp_bh))
1960 nilfs_btnode_abort_change_key(
1961 &NILFS_BMAP_I(btree)->i_btnode_cache,
1962 &path[level].bp_ctxt);
1963 }
1964
1965 static int nilfs_btree_prepare_propagate_v(struct nilfs_bmap *btree,
1966 struct nilfs_btree_path *path,
1967 int minlevel, int *maxlevelp,
1968 struct inode *dat)
1969 {
1970 int level, ret;
1971
1972 level = minlevel;
1973 if (!buffer_nilfs_volatile(path[level].bp_bh)) {
1974 ret = nilfs_btree_prepare_update_v(btree, path, level, dat);
1975 if (ret < 0)
1976 return ret;
1977 }
1978 while ((++level < nilfs_btree_height(btree) - 1) &&
1979 !buffer_dirty(path[level].bp_bh)) {
1980
1981 WARN_ON(buffer_nilfs_volatile(path[level].bp_bh));
1982 ret = nilfs_btree_prepare_update_v(btree, path, level, dat);
1983 if (ret < 0)
1984 goto out;
1985 }
1986
1987 /* success */
1988 *maxlevelp = level - 1;
1989 return 0;
1990
1991 /* error */
1992 out:
1993 while (--level > minlevel)
1994 nilfs_btree_abort_update_v(btree, path, level, dat);
1995 if (!buffer_nilfs_volatile(path[level].bp_bh))
1996 nilfs_btree_abort_update_v(btree, path, level, dat);
1997 return ret;
1998 }
1999
2000 static void nilfs_btree_commit_propagate_v(struct nilfs_bmap *btree,
2001 struct nilfs_btree_path *path,
2002 int minlevel, int maxlevel,
2003 struct buffer_head *bh,
2004 struct inode *dat)
2005 {
2006 int level;
2007
2008 if (!buffer_nilfs_volatile(path[minlevel].bp_bh))
2009 nilfs_btree_commit_update_v(btree, path, minlevel, dat);
2010
2011 for (level = minlevel + 1; level <= maxlevel; level++)
2012 nilfs_btree_commit_update_v(btree, path, level, dat);
2013 }
2014
2015 static int nilfs_btree_propagate_v(struct nilfs_bmap *btree,
2016 struct nilfs_btree_path *path,
2017 int level, struct buffer_head *bh)
2018 {
2019 int maxlevel = 0, ret;
2020 struct nilfs_btree_node *parent;
2021 struct inode *dat = nilfs_bmap_get_dat(btree);
2022 __u64 ptr;
2023 int ncmax;
2024
2025 get_bh(bh);
2026 path[level].bp_bh = bh;
2027 ret = nilfs_btree_prepare_propagate_v(btree, path, level, &maxlevel,
2028 dat);
2029 if (ret < 0)
2030 goto out;
2031
2032 if (buffer_nilfs_volatile(path[level].bp_bh)) {
2033 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
2034 ptr = nilfs_btree_node_get_ptr(parent,
2035 path[level + 1].bp_index,
2036 ncmax);
2037 ret = nilfs_dat_mark_dirty(dat, ptr);
2038 if (ret < 0)
2039 goto out;
2040 }
2041
2042 nilfs_btree_commit_propagate_v(btree, path, level, maxlevel, bh, dat);
2043
2044 out:
2045 brelse(path[level].bp_bh);
2046 path[level].bp_bh = NULL;
2047 return ret;
2048 }
2049
2050 static int nilfs_btree_propagate(struct nilfs_bmap *btree,
2051 struct buffer_head *bh)
2052 {
2053 struct nilfs_btree_path *path;
2054 struct nilfs_btree_node *node;
2055 __u64 key;
2056 int level, ret;
2057
2058 WARN_ON(!buffer_dirty(bh));
2059
2060 path = nilfs_btree_alloc_path();
2061 if (path == NULL)
2062 return -ENOMEM;
2063
2064 if (buffer_nilfs_node(bh)) {
2065 node = (struct nilfs_btree_node *)bh->b_data;
2066 key = nilfs_btree_node_get_key(node, 0);
2067 level = nilfs_btree_node_get_level(node);
2068 } else {
2069 key = nilfs_bmap_data_get_key(btree, bh);
2070 level = NILFS_BTREE_LEVEL_DATA;
2071 }
2072
2073 ret = nilfs_btree_do_lookup(btree, path, key, NULL, level + 1, 0);
2074 if (ret < 0) {
2075 if (unlikely(ret == -ENOENT))
2076 printk(KERN_CRIT "%s: key = %llu, level == %d\n",
2077 __func__, (unsigned long long)key, level);
2078 goto out;
2079 }
2080
2081 ret = NILFS_BMAP_USE_VBN(btree) ?
2082 nilfs_btree_propagate_v(btree, path, level, bh) :
2083 nilfs_btree_propagate_p(btree, path, level, bh);
2084
2085 out:
2086 nilfs_btree_free_path(path);
2087
2088 return ret;
2089 }
2090
2091 static int nilfs_btree_propagate_gc(struct nilfs_bmap *btree,
2092 struct buffer_head *bh)
2093 {
2094 return nilfs_dat_mark_dirty(nilfs_bmap_get_dat(btree), bh->b_blocknr);
2095 }
2096
2097 static void nilfs_btree_add_dirty_buffer(struct nilfs_bmap *btree,
2098 struct list_head *lists,
2099 struct buffer_head *bh)
2100 {
2101 struct list_head *head;
2102 struct buffer_head *cbh;
2103 struct nilfs_btree_node *node, *cnode;
2104 __u64 key, ckey;
2105 int level;
2106
2107 get_bh(bh);
2108 node = (struct nilfs_btree_node *)bh->b_data;
2109 key = nilfs_btree_node_get_key(node, 0);
2110 level = nilfs_btree_node_get_level(node);
2111 if (level < NILFS_BTREE_LEVEL_NODE_MIN ||
2112 level >= NILFS_BTREE_LEVEL_MAX) {
2113 dump_stack();
2114 printk(KERN_WARNING
2115 "%s: invalid btree level: %d (key=%llu, ino=%lu, "
2116 "blocknr=%llu)\n",
2117 __func__, level, (unsigned long long)key,
2118 NILFS_BMAP_I(btree)->vfs_inode.i_ino,
2119 (unsigned long long)bh->b_blocknr);
2120 return;
2121 }
2122
2123 list_for_each(head, &lists[level]) {
2124 cbh = list_entry(head, struct buffer_head, b_assoc_buffers);
2125 cnode = (struct nilfs_btree_node *)cbh->b_data;
2126 ckey = nilfs_btree_node_get_key(cnode, 0);
2127 if (key < ckey)
2128 break;
2129 }
2130 list_add_tail(&bh->b_assoc_buffers, head);
2131 }
2132
2133 static void nilfs_btree_lookup_dirty_buffers(struct nilfs_bmap *btree,
2134 struct list_head *listp)
2135 {
2136 struct address_space *btcache = &NILFS_BMAP_I(btree)->i_btnode_cache;
2137 struct list_head lists[NILFS_BTREE_LEVEL_MAX];
2138 struct pagevec pvec;
2139 struct buffer_head *bh, *head;
2140 pgoff_t index = 0;
2141 int level, i;
2142
2143 for (level = NILFS_BTREE_LEVEL_NODE_MIN;
2144 level < NILFS_BTREE_LEVEL_MAX;
2145 level++)
2146 INIT_LIST_HEAD(&lists[level]);
2147
2148 pagevec_init(&pvec, 0);
2149
2150 while (pagevec_lookup_tag(&pvec, btcache, &index, PAGECACHE_TAG_DIRTY,
2151 PAGEVEC_SIZE)) {
2152 for (i = 0; i < pagevec_count(&pvec); i++) {
2153 bh = head = page_buffers(pvec.pages[i]);
2154 do {
2155 if (buffer_dirty(bh))
2156 nilfs_btree_add_dirty_buffer(btree,
2157 lists, bh);
2158 } while ((bh = bh->b_this_page) != head);
2159 }
2160 pagevec_release(&pvec);
2161 cond_resched();
2162 }
2163
2164 for (level = NILFS_BTREE_LEVEL_NODE_MIN;
2165 level < NILFS_BTREE_LEVEL_MAX;
2166 level++)
2167 list_splice_tail(&lists[level], listp);
2168 }
2169
2170 static int nilfs_btree_assign_p(struct nilfs_bmap *btree,
2171 struct nilfs_btree_path *path,
2172 int level,
2173 struct buffer_head **bh,
2174 sector_t blocknr,
2175 union nilfs_binfo *binfo)
2176 {
2177 struct nilfs_btree_node *parent;
2178 __u64 key;
2179 __u64 ptr;
2180 int ncmax, ret;
2181
2182 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
2183 ptr = nilfs_btree_node_get_ptr(parent, path[level + 1].bp_index,
2184 ncmax);
2185 if (buffer_nilfs_node(*bh)) {
2186 path[level].bp_ctxt.oldkey = ptr;
2187 path[level].bp_ctxt.newkey = blocknr;
2188 path[level].bp_ctxt.bh = *bh;
2189 ret = nilfs_btnode_prepare_change_key(
2190 &NILFS_BMAP_I(btree)->i_btnode_cache,
2191 &path[level].bp_ctxt);
2192 if (ret < 0)
2193 return ret;
2194 nilfs_btnode_commit_change_key(
2195 &NILFS_BMAP_I(btree)->i_btnode_cache,
2196 &path[level].bp_ctxt);
2197 *bh = path[level].bp_ctxt.bh;
2198 }
2199
2200 nilfs_btree_node_set_ptr(parent, path[level + 1].bp_index, blocknr,
2201 ncmax);
2202
2203 key = nilfs_btree_node_get_key(parent, path[level + 1].bp_index);
2204 /* on-disk format */
2205 binfo->bi_dat.bi_blkoff = cpu_to_le64(key);
2206 binfo->bi_dat.bi_level = level;
2207
2208 return 0;
2209 }
2210
2211 static int nilfs_btree_assign_v(struct nilfs_bmap *btree,
2212 struct nilfs_btree_path *path,
2213 int level,
2214 struct buffer_head **bh,
2215 sector_t blocknr,
2216 union nilfs_binfo *binfo)
2217 {
2218 struct nilfs_btree_node *parent;
2219 struct inode *dat = nilfs_bmap_get_dat(btree);
2220 __u64 key;
2221 __u64 ptr;
2222 union nilfs_bmap_ptr_req req;
2223 int ncmax, ret;
2224
2225 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
2226 ptr = nilfs_btree_node_get_ptr(parent, path[level + 1].bp_index,
2227 ncmax);
2228 req.bpr_ptr = ptr;
2229 ret = nilfs_dat_prepare_start(dat, &req.bpr_req);
2230 if (ret < 0)
2231 return ret;
2232 nilfs_dat_commit_start(dat, &req.bpr_req, blocknr);
2233
2234 key = nilfs_btree_node_get_key(parent, path[level + 1].bp_index);
2235 /* on-disk format */
2236 binfo->bi_v.bi_vblocknr = cpu_to_le64(ptr);
2237 binfo->bi_v.bi_blkoff = cpu_to_le64(key);
2238
2239 return 0;
2240 }
2241
2242 static int nilfs_btree_assign(struct nilfs_bmap *btree,
2243 struct buffer_head **bh,
2244 sector_t blocknr,
2245 union nilfs_binfo *binfo)
2246 {
2247 struct nilfs_btree_path *path;
2248 struct nilfs_btree_node *node;
2249 __u64 key;
2250 int level, ret;
2251
2252 path = nilfs_btree_alloc_path();
2253 if (path == NULL)
2254 return -ENOMEM;
2255
2256 if (buffer_nilfs_node(*bh)) {
2257 node = (struct nilfs_btree_node *)(*bh)->b_data;
2258 key = nilfs_btree_node_get_key(node, 0);
2259 level = nilfs_btree_node_get_level(node);
2260 } else {
2261 key = nilfs_bmap_data_get_key(btree, *bh);
2262 level = NILFS_BTREE_LEVEL_DATA;
2263 }
2264
2265 ret = nilfs_btree_do_lookup(btree, path, key, NULL, level + 1, 0);
2266 if (ret < 0) {
2267 WARN_ON(ret == -ENOENT);
2268 goto out;
2269 }
2270
2271 ret = NILFS_BMAP_USE_VBN(btree) ?
2272 nilfs_btree_assign_v(btree, path, level, bh, blocknr, binfo) :
2273 nilfs_btree_assign_p(btree, path, level, bh, blocknr, binfo);
2274
2275 out:
2276 nilfs_btree_free_path(path);
2277
2278 return ret;
2279 }
2280
2281 static int nilfs_btree_assign_gc(struct nilfs_bmap *btree,
2282 struct buffer_head **bh,
2283 sector_t blocknr,
2284 union nilfs_binfo *binfo)
2285 {
2286 struct nilfs_btree_node *node;
2287 __u64 key;
2288 int ret;
2289
2290 ret = nilfs_dat_move(nilfs_bmap_get_dat(btree), (*bh)->b_blocknr,
2291 blocknr);
2292 if (ret < 0)
2293 return ret;
2294
2295 if (buffer_nilfs_node(*bh)) {
2296 node = (struct nilfs_btree_node *)(*bh)->b_data;
2297 key = nilfs_btree_node_get_key(node, 0);
2298 } else
2299 key = nilfs_bmap_data_get_key(btree, *bh);
2300
2301 /* on-disk format */
2302 binfo->bi_v.bi_vblocknr = cpu_to_le64((*bh)->b_blocknr);
2303 binfo->bi_v.bi_blkoff = cpu_to_le64(key);
2304
2305 return 0;
2306 }
2307
2308 static int nilfs_btree_mark(struct nilfs_bmap *btree, __u64 key, int level)
2309 {
2310 struct buffer_head *bh;
2311 struct nilfs_btree_path *path;
2312 __u64 ptr;
2313 int ret;
2314
2315 path = nilfs_btree_alloc_path();
2316 if (path == NULL)
2317 return -ENOMEM;
2318
2319 ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level + 1, 0);
2320 if (ret < 0) {
2321 WARN_ON(ret == -ENOENT);
2322 goto out;
2323 }
2324 ret = nilfs_btree_get_block(btree, ptr, &bh);
2325 if (ret < 0) {
2326 WARN_ON(ret == -ENOENT);
2327 goto out;
2328 }
2329
2330 if (!buffer_dirty(bh))
2331 mark_buffer_dirty(bh);
2332 brelse(bh);
2333 if (!nilfs_bmap_dirty(btree))
2334 nilfs_bmap_set_dirty(btree);
2335
2336 out:
2337 nilfs_btree_free_path(path);
2338 return ret;
2339 }
2340
2341 static const struct nilfs_bmap_operations nilfs_btree_ops = {
2342 .bop_lookup = nilfs_btree_lookup,
2343 .bop_lookup_contig = nilfs_btree_lookup_contig,
2344 .bop_insert = nilfs_btree_insert,
2345 .bop_delete = nilfs_btree_delete,
2346 .bop_clear = NULL,
2347
2348 .bop_propagate = nilfs_btree_propagate,
2349
2350 .bop_lookup_dirty_buffers = nilfs_btree_lookup_dirty_buffers,
2351
2352 .bop_assign = nilfs_btree_assign,
2353 .bop_mark = nilfs_btree_mark,
2354
2355 .bop_seek_key = nilfs_btree_seek_key,
2356 .bop_last_key = nilfs_btree_last_key,
2357
2358 .bop_check_insert = NULL,
2359 .bop_check_delete = nilfs_btree_check_delete,
2360 .bop_gather_data = nilfs_btree_gather_data,
2361 };
2362
2363 static const struct nilfs_bmap_operations nilfs_btree_ops_gc = {
2364 .bop_lookup = NULL,
2365 .bop_lookup_contig = NULL,
2366 .bop_insert = NULL,
2367 .bop_delete = NULL,
2368 .bop_clear = NULL,
2369
2370 .bop_propagate = nilfs_btree_propagate_gc,
2371
2372 .bop_lookup_dirty_buffers = nilfs_btree_lookup_dirty_buffers,
2373
2374 .bop_assign = nilfs_btree_assign_gc,
2375 .bop_mark = NULL,
2376
2377 .bop_seek_key = NULL,
2378 .bop_last_key = NULL,
2379
2380 .bop_check_insert = NULL,
2381 .bop_check_delete = NULL,
2382 .bop_gather_data = NULL,
2383 };
2384
2385 static void __nilfs_btree_init(struct nilfs_bmap *bmap)
2386 {
2387 bmap->b_ops = &nilfs_btree_ops;
2388 bmap->b_nchildren_per_block =
2389 NILFS_BTREE_NODE_NCHILDREN_MAX(nilfs_btree_node_size(bmap));
2390 }
2391
2392 int nilfs_btree_init(struct nilfs_bmap *bmap)
2393 {
2394 int ret = 0;
2395
2396 __nilfs_btree_init(bmap);
2397
2398 if (nilfs_btree_root_broken(nilfs_btree_get_root(bmap),
2399 bmap->b_inode->i_ino))
2400 ret = -EIO;
2401 return ret;
2402 }
2403
2404 void nilfs_btree_init_gc(struct nilfs_bmap *bmap)
2405 {
2406 bmap->b_ops = &nilfs_btree_ops_gc;
2407 bmap->b_nchildren_per_block =
2408 NILFS_BTREE_NODE_NCHILDREN_MAX(nilfs_btree_node_size(bmap));
2409 }
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