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