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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,
689 unsigned int maxblocks)
690 {
691 struct nilfs_btree_path *path;
692 struct nilfs_btree_node *node;
693 struct inode *dat = NULL;
694 __u64 ptr, ptr2;
695 sector_t blocknr;
696 int level = NILFS_BTREE_LEVEL_NODE_MIN;
697 int ret, cnt, index, maxlevel, ncmax;
698 struct nilfs_btree_readahead_info p;
699
700 path = nilfs_btree_alloc_path();
701 if (path == NULL)
702 return -ENOMEM;
703
704 ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level, 1);
705 if (ret < 0)
706 goto out;
707
708 if (NILFS_BMAP_USE_VBN(btree)) {
709 dat = nilfs_bmap_get_dat(btree);
710 ret = nilfs_dat_translate(dat, ptr, &blocknr);
711 if (ret < 0)
712 goto out;
713 ptr = blocknr;
714 }
715 cnt = 1;
716 if (cnt == maxblocks)
717 goto end;
718
719 maxlevel = nilfs_btree_height(btree) - 1;
720 node = nilfs_btree_get_node(btree, path, level, &ncmax);
721 index = path[level].bp_index + 1;
722 for (;;) {
723 while (index < nilfs_btree_node_get_nchildren(node)) {
724 if (nilfs_btree_node_get_key(node, index) !=
725 key + cnt)
726 goto end;
727 ptr2 = nilfs_btree_node_get_ptr(node, index, ncmax);
728 if (dat) {
729 ret = nilfs_dat_translate(dat, ptr2, &blocknr);
730 if (ret < 0)
731 goto out;
732 ptr2 = blocknr;
733 }
734 if (ptr2 != ptr + cnt || ++cnt == maxblocks)
735 goto end;
736 index++;
737 continue;
738 }
739 if (level == maxlevel)
740 break;
741
742 /* look-up right sibling node */
743 p.node = nilfs_btree_get_node(btree, path, level + 1, &p.ncmax);
744 p.index = path[level + 1].bp_index + 1;
745 p.max_ra_blocks = 7;
746 if (p.index >= nilfs_btree_node_get_nchildren(p.node) ||
747 nilfs_btree_node_get_key(p.node, p.index) != key + cnt)
748 break;
749 ptr2 = nilfs_btree_node_get_ptr(p.node, p.index, p.ncmax);
750 path[level + 1].bp_index = p.index;
751
752 brelse(path[level].bp_bh);
753 path[level].bp_bh = NULL;
754
755 ret = __nilfs_btree_get_block(btree, ptr2, &path[level].bp_bh,
756 &p);
757 if (ret < 0)
758 goto out;
759 node = nilfs_btree_get_nonroot_node(path, level);
760 ncmax = nilfs_btree_nchildren_per_block(btree);
761 index = 0;
762 path[level].bp_index = index;
763 }
764 end:
765 *ptrp = ptr;
766 ret = cnt;
767 out:
768 nilfs_btree_free_path(path);
769 return ret;
770 }
771
772 static void nilfs_btree_promote_key(struct nilfs_bmap *btree,
773 struct nilfs_btree_path *path,
774 int level, __u64 key)
775 {
776 if (level < nilfs_btree_height(btree) - 1) {
777 do {
778 nilfs_btree_node_set_key(
779 nilfs_btree_get_nonroot_node(path, level),
780 path[level].bp_index, key);
781 if (!buffer_dirty(path[level].bp_bh))
782 mark_buffer_dirty(path[level].bp_bh);
783 } while ((path[level].bp_index == 0) &&
784 (++level < nilfs_btree_height(btree) - 1));
785 }
786
787 /* root */
788 if (level == nilfs_btree_height(btree) - 1) {
789 nilfs_btree_node_set_key(nilfs_btree_get_root(btree),
790 path[level].bp_index, key);
791 }
792 }
793
794 static void nilfs_btree_do_insert(struct nilfs_bmap *btree,
795 struct nilfs_btree_path *path,
796 int level, __u64 *keyp, __u64 *ptrp)
797 {
798 struct nilfs_btree_node *node;
799 int ncblk;
800
801 if (level < nilfs_btree_height(btree) - 1) {
802 node = nilfs_btree_get_nonroot_node(path, level);
803 ncblk = nilfs_btree_nchildren_per_block(btree);
804 nilfs_btree_node_insert(node, path[level].bp_index,
805 *keyp, *ptrp, ncblk);
806 if (!buffer_dirty(path[level].bp_bh))
807 mark_buffer_dirty(path[level].bp_bh);
808
809 if (path[level].bp_index == 0)
810 nilfs_btree_promote_key(btree, path, level + 1,
811 nilfs_btree_node_get_key(node,
812 0));
813 } else {
814 node = nilfs_btree_get_root(btree);
815 nilfs_btree_node_insert(node, path[level].bp_index,
816 *keyp, *ptrp,
817 NILFS_BTREE_ROOT_NCHILDREN_MAX);
818 }
819 }
820
821 static void nilfs_btree_carry_left(struct nilfs_bmap *btree,
822 struct nilfs_btree_path *path,
823 int level, __u64 *keyp, __u64 *ptrp)
824 {
825 struct nilfs_btree_node *node, *left;
826 int nchildren, lnchildren, n, move, ncblk;
827
828 node = nilfs_btree_get_nonroot_node(path, level);
829 left = nilfs_btree_get_sib_node(path, level);
830 nchildren = nilfs_btree_node_get_nchildren(node);
831 lnchildren = nilfs_btree_node_get_nchildren(left);
832 ncblk = nilfs_btree_nchildren_per_block(btree);
833 move = 0;
834
835 n = (nchildren + lnchildren + 1) / 2 - lnchildren;
836 if (n > path[level].bp_index) {
837 /* move insert point */
838 n--;
839 move = 1;
840 }
841
842 nilfs_btree_node_move_left(left, node, n, ncblk, ncblk);
843
844 if (!buffer_dirty(path[level].bp_bh))
845 mark_buffer_dirty(path[level].bp_bh);
846 if (!buffer_dirty(path[level].bp_sib_bh))
847 mark_buffer_dirty(path[level].bp_sib_bh);
848
849 nilfs_btree_promote_key(btree, path, level + 1,
850 nilfs_btree_node_get_key(node, 0));
851
852 if (move) {
853 brelse(path[level].bp_bh);
854 path[level].bp_bh = path[level].bp_sib_bh;
855 path[level].bp_sib_bh = NULL;
856 path[level].bp_index += lnchildren;
857 path[level + 1].bp_index--;
858 } else {
859 brelse(path[level].bp_sib_bh);
860 path[level].bp_sib_bh = NULL;
861 path[level].bp_index -= n;
862 }
863
864 nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
865 }
866
867 static void nilfs_btree_carry_right(struct nilfs_bmap *btree,
868 struct nilfs_btree_path *path,
869 int level, __u64 *keyp, __u64 *ptrp)
870 {
871 struct nilfs_btree_node *node, *right;
872 int nchildren, rnchildren, n, move, ncblk;
873
874 node = nilfs_btree_get_nonroot_node(path, level);
875 right = nilfs_btree_get_sib_node(path, level);
876 nchildren = nilfs_btree_node_get_nchildren(node);
877 rnchildren = nilfs_btree_node_get_nchildren(right);
878 ncblk = nilfs_btree_nchildren_per_block(btree);
879 move = 0;
880
881 n = (nchildren + rnchildren + 1) / 2 - rnchildren;
882 if (n > nchildren - path[level].bp_index) {
883 /* move insert point */
884 n--;
885 move = 1;
886 }
887
888 nilfs_btree_node_move_right(node, right, n, ncblk, ncblk);
889
890 if (!buffer_dirty(path[level].bp_bh))
891 mark_buffer_dirty(path[level].bp_bh);
892 if (!buffer_dirty(path[level].bp_sib_bh))
893 mark_buffer_dirty(path[level].bp_sib_bh);
894
895 path[level + 1].bp_index++;
896 nilfs_btree_promote_key(btree, path, level + 1,
897 nilfs_btree_node_get_key(right, 0));
898 path[level + 1].bp_index--;
899
900 if (move) {
901 brelse(path[level].bp_bh);
902 path[level].bp_bh = path[level].bp_sib_bh;
903 path[level].bp_sib_bh = NULL;
904 path[level].bp_index -= nilfs_btree_node_get_nchildren(node);
905 path[level + 1].bp_index++;
906 } else {
907 brelse(path[level].bp_sib_bh);
908 path[level].bp_sib_bh = NULL;
909 }
910
911 nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
912 }
913
914 static void nilfs_btree_split(struct nilfs_bmap *btree,
915 struct nilfs_btree_path *path,
916 int level, __u64 *keyp, __u64 *ptrp)
917 {
918 struct nilfs_btree_node *node, *right;
919 int nchildren, n, move, ncblk;
920
921 node = nilfs_btree_get_nonroot_node(path, level);
922 right = nilfs_btree_get_sib_node(path, level);
923 nchildren = nilfs_btree_node_get_nchildren(node);
924 ncblk = nilfs_btree_nchildren_per_block(btree);
925 move = 0;
926
927 n = (nchildren + 1) / 2;
928 if (n > nchildren - path[level].bp_index) {
929 n--;
930 move = 1;
931 }
932
933 nilfs_btree_node_move_right(node, right, n, ncblk, ncblk);
934
935 if (!buffer_dirty(path[level].bp_bh))
936 mark_buffer_dirty(path[level].bp_bh);
937 if (!buffer_dirty(path[level].bp_sib_bh))
938 mark_buffer_dirty(path[level].bp_sib_bh);
939
940 if (move) {
941 path[level].bp_index -= nilfs_btree_node_get_nchildren(node);
942 nilfs_btree_node_insert(right, path[level].bp_index,
943 *keyp, *ptrp, ncblk);
944
945 *keyp = nilfs_btree_node_get_key(right, 0);
946 *ptrp = path[level].bp_newreq.bpr_ptr;
947
948 brelse(path[level].bp_bh);
949 path[level].bp_bh = path[level].bp_sib_bh;
950 path[level].bp_sib_bh = NULL;
951 } else {
952 nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
953
954 *keyp = nilfs_btree_node_get_key(right, 0);
955 *ptrp = path[level].bp_newreq.bpr_ptr;
956
957 brelse(path[level].bp_sib_bh);
958 path[level].bp_sib_bh = NULL;
959 }
960
961 path[level + 1].bp_index++;
962 }
963
964 static void nilfs_btree_grow(struct nilfs_bmap *btree,
965 struct nilfs_btree_path *path,
966 int level, __u64 *keyp, __u64 *ptrp)
967 {
968 struct nilfs_btree_node *root, *child;
969 int n, ncblk;
970
971 root = nilfs_btree_get_root(btree);
972 child = nilfs_btree_get_sib_node(path, level);
973 ncblk = nilfs_btree_nchildren_per_block(btree);
974
975 n = nilfs_btree_node_get_nchildren(root);
976
977 nilfs_btree_node_move_right(root, child, n,
978 NILFS_BTREE_ROOT_NCHILDREN_MAX, ncblk);
979 nilfs_btree_node_set_level(root, level + 1);
980
981 if (!buffer_dirty(path[level].bp_sib_bh))
982 mark_buffer_dirty(path[level].bp_sib_bh);
983
984 path[level].bp_bh = path[level].bp_sib_bh;
985 path[level].bp_sib_bh = NULL;
986
987 nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
988
989 *keyp = nilfs_btree_node_get_key(child, 0);
990 *ptrp = path[level].bp_newreq.bpr_ptr;
991 }
992
993 static __u64 nilfs_btree_find_near(const struct nilfs_bmap *btree,
994 const struct nilfs_btree_path *path)
995 {
996 struct nilfs_btree_node *node;
997 int level, ncmax;
998
999 if (path == NULL)
1000 return NILFS_BMAP_INVALID_PTR;
1001
1002 /* left sibling */
1003 level = NILFS_BTREE_LEVEL_NODE_MIN;
1004 if (path[level].bp_index > 0) {
1005 node = nilfs_btree_get_node(btree, path, level, &ncmax);
1006 return nilfs_btree_node_get_ptr(node,
1007 path[level].bp_index - 1,
1008 ncmax);
1009 }
1010
1011 /* parent */
1012 level = NILFS_BTREE_LEVEL_NODE_MIN + 1;
1013 if (level <= nilfs_btree_height(btree) - 1) {
1014 node = nilfs_btree_get_node(btree, path, level, &ncmax);
1015 return nilfs_btree_node_get_ptr(node, path[level].bp_index,
1016 ncmax);
1017 }
1018
1019 return NILFS_BMAP_INVALID_PTR;
1020 }
1021
1022 static __u64 nilfs_btree_find_target_v(const struct nilfs_bmap *btree,
1023 const struct nilfs_btree_path *path,
1024 __u64 key)
1025 {
1026 __u64 ptr;
1027
1028 ptr = nilfs_bmap_find_target_seq(btree, key);
1029 if (ptr != NILFS_BMAP_INVALID_PTR)
1030 /* sequential access */
1031 return ptr;
1032 else {
1033 ptr = nilfs_btree_find_near(btree, path);
1034 if (ptr != NILFS_BMAP_INVALID_PTR)
1035 /* near */
1036 return ptr;
1037 }
1038 /* block group */
1039 return nilfs_bmap_find_target_in_group(btree);
1040 }
1041
1042 static int nilfs_btree_prepare_insert(struct nilfs_bmap *btree,
1043 struct nilfs_btree_path *path,
1044 int *levelp, __u64 key, __u64 ptr,
1045 struct nilfs_bmap_stats *stats)
1046 {
1047 struct buffer_head *bh;
1048 struct nilfs_btree_node *node, *parent, *sib;
1049 __u64 sibptr;
1050 int pindex, level, ncmax, ncblk, ret;
1051 struct inode *dat = NULL;
1052
1053 stats->bs_nblocks = 0;
1054 level = NILFS_BTREE_LEVEL_DATA;
1055
1056 /* allocate a new ptr for data block */
1057 if (NILFS_BMAP_USE_VBN(btree)) {
1058 path[level].bp_newreq.bpr_ptr =
1059 nilfs_btree_find_target_v(btree, path, key);
1060 dat = nilfs_bmap_get_dat(btree);
1061 }
1062
1063 ret = nilfs_bmap_prepare_alloc_ptr(btree, &path[level].bp_newreq, dat);
1064 if (ret < 0)
1065 goto err_out_data;
1066
1067 ncblk = nilfs_btree_nchildren_per_block(btree);
1068
1069 for (level = NILFS_BTREE_LEVEL_NODE_MIN;
1070 level < nilfs_btree_height(btree) - 1;
1071 level++) {
1072 node = nilfs_btree_get_nonroot_node(path, level);
1073 if (nilfs_btree_node_get_nchildren(node) < ncblk) {
1074 path[level].bp_op = nilfs_btree_do_insert;
1075 stats->bs_nblocks++;
1076 goto out;
1077 }
1078
1079 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
1080 pindex = path[level + 1].bp_index;
1081
1082 /* left sibling */
1083 if (pindex > 0) {
1084 sibptr = nilfs_btree_node_get_ptr(parent, pindex - 1,
1085 ncmax);
1086 ret = nilfs_btree_get_block(btree, sibptr, &bh);
1087 if (ret < 0)
1088 goto err_out_child_node;
1089 sib = (struct nilfs_btree_node *)bh->b_data;
1090 if (nilfs_btree_node_get_nchildren(sib) < ncblk) {
1091 path[level].bp_sib_bh = bh;
1092 path[level].bp_op = nilfs_btree_carry_left;
1093 stats->bs_nblocks++;
1094 goto out;
1095 } else {
1096 brelse(bh);
1097 }
1098 }
1099
1100 /* right sibling */
1101 if (pindex < nilfs_btree_node_get_nchildren(parent) - 1) {
1102 sibptr = nilfs_btree_node_get_ptr(parent, pindex + 1,
1103 ncmax);
1104 ret = nilfs_btree_get_block(btree, sibptr, &bh);
1105 if (ret < 0)
1106 goto err_out_child_node;
1107 sib = (struct nilfs_btree_node *)bh->b_data;
1108 if (nilfs_btree_node_get_nchildren(sib) < ncblk) {
1109 path[level].bp_sib_bh = bh;
1110 path[level].bp_op = nilfs_btree_carry_right;
1111 stats->bs_nblocks++;
1112 goto out;
1113 } else {
1114 brelse(bh);
1115 }
1116 }
1117
1118 /* split */
1119 path[level].bp_newreq.bpr_ptr =
1120 path[level - 1].bp_newreq.bpr_ptr + 1;
1121 ret = nilfs_bmap_prepare_alloc_ptr(btree,
1122 &path[level].bp_newreq, dat);
1123 if (ret < 0)
1124 goto err_out_child_node;
1125 ret = nilfs_btree_get_new_block(btree,
1126 path[level].bp_newreq.bpr_ptr,
1127 &bh);
1128 if (ret < 0)
1129 goto err_out_curr_node;
1130
1131 stats->bs_nblocks++;
1132
1133 sib = (struct nilfs_btree_node *)bh->b_data;
1134 nilfs_btree_node_init(sib, 0, level, 0, ncblk, NULL, NULL);
1135 path[level].bp_sib_bh = bh;
1136 path[level].bp_op = nilfs_btree_split;
1137 }
1138
1139 /* root */
1140 node = nilfs_btree_get_root(btree);
1141 if (nilfs_btree_node_get_nchildren(node) <
1142 NILFS_BTREE_ROOT_NCHILDREN_MAX) {
1143 path[level].bp_op = nilfs_btree_do_insert;
1144 stats->bs_nblocks++;
1145 goto out;
1146 }
1147
1148 /* grow */
1149 path[level].bp_newreq.bpr_ptr = path[level - 1].bp_newreq.bpr_ptr + 1;
1150 ret = nilfs_bmap_prepare_alloc_ptr(btree, &path[level].bp_newreq, dat);
1151 if (ret < 0)
1152 goto err_out_child_node;
1153 ret = nilfs_btree_get_new_block(btree, path[level].bp_newreq.bpr_ptr,
1154 &bh);
1155 if (ret < 0)
1156 goto err_out_curr_node;
1157
1158 nilfs_btree_node_init((struct nilfs_btree_node *)bh->b_data,
1159 0, level, 0, ncblk, NULL, NULL);
1160 path[level].bp_sib_bh = bh;
1161 path[level].bp_op = nilfs_btree_grow;
1162
1163 level++;
1164 path[level].bp_op = nilfs_btree_do_insert;
1165
1166 /* a newly-created node block and a data block are added */
1167 stats->bs_nblocks += 2;
1168
1169 /* success */
1170 out:
1171 *levelp = level;
1172 return ret;
1173
1174 /* error */
1175 err_out_curr_node:
1176 nilfs_bmap_abort_alloc_ptr(btree, &path[level].bp_newreq, dat);
1177 err_out_child_node:
1178 for (level--; level > NILFS_BTREE_LEVEL_DATA; level--) {
1179 nilfs_btnode_delete(path[level].bp_sib_bh);
1180 nilfs_bmap_abort_alloc_ptr(btree, &path[level].bp_newreq, dat);
1181
1182 }
1183
1184 nilfs_bmap_abort_alloc_ptr(btree, &path[level].bp_newreq, dat);
1185 err_out_data:
1186 *levelp = level;
1187 stats->bs_nblocks = 0;
1188 return ret;
1189 }
1190
1191 static void nilfs_btree_commit_insert(struct nilfs_bmap *btree,
1192 struct nilfs_btree_path *path,
1193 int maxlevel, __u64 key, __u64 ptr)
1194 {
1195 struct inode *dat = NULL;
1196 int level;
1197
1198 set_buffer_nilfs_volatile((struct buffer_head *)((unsigned long)ptr));
1199 ptr = path[NILFS_BTREE_LEVEL_DATA].bp_newreq.bpr_ptr;
1200 if (NILFS_BMAP_USE_VBN(btree)) {
1201 nilfs_bmap_set_target_v(btree, key, ptr);
1202 dat = nilfs_bmap_get_dat(btree);
1203 }
1204
1205 for (level = NILFS_BTREE_LEVEL_NODE_MIN; level <= maxlevel; level++) {
1206 nilfs_bmap_commit_alloc_ptr(btree,
1207 &path[level - 1].bp_newreq, dat);
1208 path[level].bp_op(btree, path, level, &key, &ptr);
1209 }
1210
1211 if (!nilfs_bmap_dirty(btree))
1212 nilfs_bmap_set_dirty(btree);
1213 }
1214
1215 static int nilfs_btree_insert(struct nilfs_bmap *btree, __u64 key, __u64 ptr)
1216 {
1217 struct nilfs_btree_path *path;
1218 struct nilfs_bmap_stats stats;
1219 int level, ret;
1220
1221 path = nilfs_btree_alloc_path();
1222 if (path == NULL)
1223 return -ENOMEM;
1224
1225 ret = nilfs_btree_do_lookup(btree, path, key, NULL,
1226 NILFS_BTREE_LEVEL_NODE_MIN, 0);
1227 if (ret != -ENOENT) {
1228 if (ret == 0)
1229 ret = -EEXIST;
1230 goto out;
1231 }
1232
1233 ret = nilfs_btree_prepare_insert(btree, path, &level, key, ptr, &stats);
1234 if (ret < 0)
1235 goto out;
1236 nilfs_btree_commit_insert(btree, path, level, key, ptr);
1237 nilfs_inode_add_blocks(btree->b_inode, stats.bs_nblocks);
1238
1239 out:
1240 nilfs_btree_free_path(path);
1241 return ret;
1242 }
1243
1244 static void nilfs_btree_do_delete(struct nilfs_bmap *btree,
1245 struct nilfs_btree_path *path,
1246 int level, __u64 *keyp, __u64 *ptrp)
1247 {
1248 struct nilfs_btree_node *node;
1249 int ncblk;
1250
1251 if (level < nilfs_btree_height(btree) - 1) {
1252 node = nilfs_btree_get_nonroot_node(path, level);
1253 ncblk = nilfs_btree_nchildren_per_block(btree);
1254 nilfs_btree_node_delete(node, path[level].bp_index,
1255 keyp, ptrp, ncblk);
1256 if (!buffer_dirty(path[level].bp_bh))
1257 mark_buffer_dirty(path[level].bp_bh);
1258 if (path[level].bp_index == 0)
1259 nilfs_btree_promote_key(btree, path, level + 1,
1260 nilfs_btree_node_get_key(node, 0));
1261 } else {
1262 node = nilfs_btree_get_root(btree);
1263 nilfs_btree_node_delete(node, path[level].bp_index,
1264 keyp, ptrp,
1265 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1266 }
1267 }
1268
1269 static void nilfs_btree_borrow_left(struct nilfs_bmap *btree,
1270 struct nilfs_btree_path *path,
1271 int level, __u64 *keyp, __u64 *ptrp)
1272 {
1273 struct nilfs_btree_node *node, *left;
1274 int nchildren, lnchildren, n, ncblk;
1275
1276 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1277
1278 node = nilfs_btree_get_nonroot_node(path, level);
1279 left = nilfs_btree_get_sib_node(path, level);
1280 nchildren = nilfs_btree_node_get_nchildren(node);
1281 lnchildren = nilfs_btree_node_get_nchildren(left);
1282 ncblk = nilfs_btree_nchildren_per_block(btree);
1283
1284 n = (nchildren + lnchildren) / 2 - nchildren;
1285
1286 nilfs_btree_node_move_right(left, node, n, ncblk, ncblk);
1287
1288 if (!buffer_dirty(path[level].bp_bh))
1289 mark_buffer_dirty(path[level].bp_bh);
1290 if (!buffer_dirty(path[level].bp_sib_bh))
1291 mark_buffer_dirty(path[level].bp_sib_bh);
1292
1293 nilfs_btree_promote_key(btree, path, level + 1,
1294 nilfs_btree_node_get_key(node, 0));
1295
1296 brelse(path[level].bp_sib_bh);
1297 path[level].bp_sib_bh = NULL;
1298 path[level].bp_index += n;
1299 }
1300
1301 static void nilfs_btree_borrow_right(struct nilfs_bmap *btree,
1302 struct nilfs_btree_path *path,
1303 int level, __u64 *keyp, __u64 *ptrp)
1304 {
1305 struct nilfs_btree_node *node, *right;
1306 int nchildren, rnchildren, n, ncblk;
1307
1308 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1309
1310 node = nilfs_btree_get_nonroot_node(path, level);
1311 right = nilfs_btree_get_sib_node(path, level);
1312 nchildren = nilfs_btree_node_get_nchildren(node);
1313 rnchildren = nilfs_btree_node_get_nchildren(right);
1314 ncblk = nilfs_btree_nchildren_per_block(btree);
1315
1316 n = (nchildren + rnchildren) / 2 - nchildren;
1317
1318 nilfs_btree_node_move_left(node, right, n, ncblk, ncblk);
1319
1320 if (!buffer_dirty(path[level].bp_bh))
1321 mark_buffer_dirty(path[level].bp_bh);
1322 if (!buffer_dirty(path[level].bp_sib_bh))
1323 mark_buffer_dirty(path[level].bp_sib_bh);
1324
1325 path[level + 1].bp_index++;
1326 nilfs_btree_promote_key(btree, path, level + 1,
1327 nilfs_btree_node_get_key(right, 0));
1328 path[level + 1].bp_index--;
1329
1330 brelse(path[level].bp_sib_bh);
1331 path[level].bp_sib_bh = NULL;
1332 }
1333
1334 static void nilfs_btree_concat_left(struct nilfs_bmap *btree,
1335 struct nilfs_btree_path *path,
1336 int level, __u64 *keyp, __u64 *ptrp)
1337 {
1338 struct nilfs_btree_node *node, *left;
1339 int n, ncblk;
1340
1341 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1342
1343 node = nilfs_btree_get_nonroot_node(path, level);
1344 left = nilfs_btree_get_sib_node(path, level);
1345 ncblk = nilfs_btree_nchildren_per_block(btree);
1346
1347 n = nilfs_btree_node_get_nchildren(node);
1348
1349 nilfs_btree_node_move_left(left, node, n, ncblk, ncblk);
1350
1351 if (!buffer_dirty(path[level].bp_sib_bh))
1352 mark_buffer_dirty(path[level].bp_sib_bh);
1353
1354 nilfs_btnode_delete(path[level].bp_bh);
1355 path[level].bp_bh = path[level].bp_sib_bh;
1356 path[level].bp_sib_bh = NULL;
1357 path[level].bp_index += nilfs_btree_node_get_nchildren(left);
1358 }
1359
1360 static void nilfs_btree_concat_right(struct nilfs_bmap *btree,
1361 struct nilfs_btree_path *path,
1362 int level, __u64 *keyp, __u64 *ptrp)
1363 {
1364 struct nilfs_btree_node *node, *right;
1365 int n, ncblk;
1366
1367 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1368
1369 node = nilfs_btree_get_nonroot_node(path, level);
1370 right = nilfs_btree_get_sib_node(path, level);
1371 ncblk = nilfs_btree_nchildren_per_block(btree);
1372
1373 n = nilfs_btree_node_get_nchildren(right);
1374
1375 nilfs_btree_node_move_left(node, right, n, ncblk, ncblk);
1376
1377 if (!buffer_dirty(path[level].bp_bh))
1378 mark_buffer_dirty(path[level].bp_bh);
1379
1380 nilfs_btnode_delete(path[level].bp_sib_bh);
1381 path[level].bp_sib_bh = NULL;
1382 path[level + 1].bp_index++;
1383 }
1384
1385 static void nilfs_btree_shrink(struct nilfs_bmap *btree,
1386 struct nilfs_btree_path *path,
1387 int level, __u64 *keyp, __u64 *ptrp)
1388 {
1389 struct nilfs_btree_node *root, *child;
1390 int n, ncblk;
1391
1392 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1393
1394 root = nilfs_btree_get_root(btree);
1395 child = nilfs_btree_get_nonroot_node(path, level);
1396 ncblk = nilfs_btree_nchildren_per_block(btree);
1397
1398 nilfs_btree_node_delete(root, 0, NULL, NULL,
1399 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1400 nilfs_btree_node_set_level(root, level);
1401 n = nilfs_btree_node_get_nchildren(child);
1402 nilfs_btree_node_move_left(root, child, n,
1403 NILFS_BTREE_ROOT_NCHILDREN_MAX, ncblk);
1404
1405 nilfs_btnode_delete(path[level].bp_bh);
1406 path[level].bp_bh = NULL;
1407 }
1408
1409 static void nilfs_btree_nop(struct nilfs_bmap *btree,
1410 struct nilfs_btree_path *path,
1411 int level, __u64 *keyp, __u64 *ptrp)
1412 {
1413 }
1414
1415 static int nilfs_btree_prepare_delete(struct nilfs_bmap *btree,
1416 struct nilfs_btree_path *path,
1417 int *levelp,
1418 struct nilfs_bmap_stats *stats,
1419 struct inode *dat)
1420 {
1421 struct buffer_head *bh;
1422 struct nilfs_btree_node *node, *parent, *sib;
1423 __u64 sibptr;
1424 int pindex, dindex, level, ncmin, ncmax, ncblk, ret;
1425
1426 ret = 0;
1427 stats->bs_nblocks = 0;
1428 ncmin = NILFS_BTREE_NODE_NCHILDREN_MIN(nilfs_btree_node_size(btree));
1429 ncblk = nilfs_btree_nchildren_per_block(btree);
1430
1431 for (level = NILFS_BTREE_LEVEL_NODE_MIN, dindex = path[level].bp_index;
1432 level < nilfs_btree_height(btree) - 1;
1433 level++) {
1434 node = nilfs_btree_get_nonroot_node(path, level);
1435 path[level].bp_oldreq.bpr_ptr =
1436 nilfs_btree_node_get_ptr(node, dindex, ncblk);
1437 ret = nilfs_bmap_prepare_end_ptr(btree,
1438 &path[level].bp_oldreq, dat);
1439 if (ret < 0)
1440 goto err_out_child_node;
1441
1442 if (nilfs_btree_node_get_nchildren(node) > ncmin) {
1443 path[level].bp_op = nilfs_btree_do_delete;
1444 stats->bs_nblocks++;
1445 goto out;
1446 }
1447
1448 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
1449 pindex = path[level + 1].bp_index;
1450 dindex = pindex;
1451
1452 if (pindex > 0) {
1453 /* left sibling */
1454 sibptr = nilfs_btree_node_get_ptr(parent, pindex - 1,
1455 ncmax);
1456 ret = nilfs_btree_get_block(btree, sibptr, &bh);
1457 if (ret < 0)
1458 goto err_out_curr_node;
1459 sib = (struct nilfs_btree_node *)bh->b_data;
1460 if (nilfs_btree_node_get_nchildren(sib) > ncmin) {
1461 path[level].bp_sib_bh = bh;
1462 path[level].bp_op = nilfs_btree_borrow_left;
1463 stats->bs_nblocks++;
1464 goto out;
1465 } else {
1466 path[level].bp_sib_bh = bh;
1467 path[level].bp_op = nilfs_btree_concat_left;
1468 stats->bs_nblocks++;
1469 /* continue; */
1470 }
1471 } else if (pindex <
1472 nilfs_btree_node_get_nchildren(parent) - 1) {
1473 /* right sibling */
1474 sibptr = nilfs_btree_node_get_ptr(parent, pindex + 1,
1475 ncmax);
1476 ret = nilfs_btree_get_block(btree, sibptr, &bh);
1477 if (ret < 0)
1478 goto err_out_curr_node;
1479 sib = (struct nilfs_btree_node *)bh->b_data;
1480 if (nilfs_btree_node_get_nchildren(sib) > ncmin) {
1481 path[level].bp_sib_bh = bh;
1482 path[level].bp_op = nilfs_btree_borrow_right;
1483 stats->bs_nblocks++;
1484 goto out;
1485 } else {
1486 path[level].bp_sib_bh = bh;
1487 path[level].bp_op = nilfs_btree_concat_right;
1488 stats->bs_nblocks++;
1489 /*
1490 * When merging right sibling node
1491 * into the current node, pointer to
1492 * the right sibling node must be
1493 * terminated instead. The adjustment
1494 * below is required for that.
1495 */
1496 dindex = pindex + 1;
1497 /* continue; */
1498 }
1499 } else {
1500 /* no siblings */
1501 /* the only child of the root node */
1502 WARN_ON(level != nilfs_btree_height(btree) - 2);
1503 if (nilfs_btree_node_get_nchildren(node) - 1 <=
1504 NILFS_BTREE_ROOT_NCHILDREN_MAX) {
1505 path[level].bp_op = nilfs_btree_shrink;
1506 stats->bs_nblocks += 2;
1507 level++;
1508 path[level].bp_op = nilfs_btree_nop;
1509 goto shrink_root_child;
1510 } else {
1511 path[level].bp_op = nilfs_btree_do_delete;
1512 stats->bs_nblocks++;
1513 goto out;
1514 }
1515 }
1516 }
1517
1518 /* child of the root node is deleted */
1519 path[level].bp_op = nilfs_btree_do_delete;
1520 stats->bs_nblocks++;
1521
1522 shrink_root_child:
1523 node = nilfs_btree_get_root(btree);
1524 path[level].bp_oldreq.bpr_ptr =
1525 nilfs_btree_node_get_ptr(node, dindex,
1526 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1527
1528 ret = nilfs_bmap_prepare_end_ptr(btree, &path[level].bp_oldreq, dat);
1529 if (ret < 0)
1530 goto err_out_child_node;
1531
1532 /* success */
1533 out:
1534 *levelp = level;
1535 return ret;
1536
1537 /* error */
1538 err_out_curr_node:
1539 nilfs_bmap_abort_end_ptr(btree, &path[level].bp_oldreq, dat);
1540 err_out_child_node:
1541 for (level--; level >= NILFS_BTREE_LEVEL_NODE_MIN; level--) {
1542 brelse(path[level].bp_sib_bh);
1543 nilfs_bmap_abort_end_ptr(btree, &path[level].bp_oldreq, dat);
1544 }
1545 *levelp = level;
1546 stats->bs_nblocks = 0;
1547 return ret;
1548 }
1549
1550 static void nilfs_btree_commit_delete(struct nilfs_bmap *btree,
1551 struct nilfs_btree_path *path,
1552 int maxlevel, struct inode *dat)
1553 {
1554 int level;
1555
1556 for (level = NILFS_BTREE_LEVEL_NODE_MIN; level <= maxlevel; level++) {
1557 nilfs_bmap_commit_end_ptr(btree, &path[level].bp_oldreq, dat);
1558 path[level].bp_op(btree, path, level, NULL, NULL);
1559 }
1560
1561 if (!nilfs_bmap_dirty(btree))
1562 nilfs_bmap_set_dirty(btree);
1563 }
1564
1565 static int nilfs_btree_delete(struct nilfs_bmap *btree, __u64 key)
1566
1567 {
1568 struct nilfs_btree_path *path;
1569 struct nilfs_bmap_stats stats;
1570 struct inode *dat;
1571 int level, ret;
1572
1573 path = nilfs_btree_alloc_path();
1574 if (path == NULL)
1575 return -ENOMEM;
1576
1577 ret = nilfs_btree_do_lookup(btree, path, key, NULL,
1578 NILFS_BTREE_LEVEL_NODE_MIN, 0);
1579 if (ret < 0)
1580 goto out;
1581
1582
1583 dat = NILFS_BMAP_USE_VBN(btree) ? nilfs_bmap_get_dat(btree) : NULL;
1584
1585 ret = nilfs_btree_prepare_delete(btree, path, &level, &stats, dat);
1586 if (ret < 0)
1587 goto out;
1588 nilfs_btree_commit_delete(btree, path, level, dat);
1589 nilfs_inode_sub_blocks(btree->b_inode, stats.bs_nblocks);
1590
1591 out:
1592 nilfs_btree_free_path(path);
1593 return ret;
1594 }
1595
1596 static int nilfs_btree_seek_key(const struct nilfs_bmap *btree, __u64 start,
1597 __u64 *keyp)
1598 {
1599 struct nilfs_btree_path *path;
1600 const int minlevel = NILFS_BTREE_LEVEL_NODE_MIN;
1601 int ret;
1602
1603 path = nilfs_btree_alloc_path();
1604 if (!path)
1605 return -ENOMEM;
1606
1607 ret = nilfs_btree_do_lookup(btree, path, start, NULL, minlevel, 0);
1608 if (!ret)
1609 *keyp = start;
1610 else if (ret == -ENOENT)
1611 ret = nilfs_btree_get_next_key(btree, path, minlevel, keyp);
1612
1613 nilfs_btree_free_path(path);
1614 return ret;
1615 }
1616
1617 static int nilfs_btree_last_key(const struct nilfs_bmap *btree, __u64 *keyp)
1618 {
1619 struct nilfs_btree_path *path;
1620 int ret;
1621
1622 path = nilfs_btree_alloc_path();
1623 if (path == NULL)
1624 return -ENOMEM;
1625
1626 ret = nilfs_btree_do_lookup_last(btree, path, keyp, NULL);
1627
1628 nilfs_btree_free_path(path);
1629
1630 return ret;
1631 }
1632
1633 static int nilfs_btree_check_delete(struct nilfs_bmap *btree, __u64 key)
1634 {
1635 struct buffer_head *bh;
1636 struct nilfs_btree_node *root, *node;
1637 __u64 maxkey, nextmaxkey;
1638 __u64 ptr;
1639 int nchildren, ret;
1640
1641 root = nilfs_btree_get_root(btree);
1642 switch (nilfs_btree_height(btree)) {
1643 case 2:
1644 bh = NULL;
1645 node = root;
1646 break;
1647 case 3:
1648 nchildren = nilfs_btree_node_get_nchildren(root);
1649 if (nchildren > 1)
1650 return 0;
1651 ptr = nilfs_btree_node_get_ptr(root, nchildren - 1,
1652 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1653 ret = nilfs_btree_get_block(btree, ptr, &bh);
1654 if (ret < 0)
1655 return ret;
1656 node = (struct nilfs_btree_node *)bh->b_data;
1657 break;
1658 default:
1659 return 0;
1660 }
1661
1662 nchildren = nilfs_btree_node_get_nchildren(node);
1663 maxkey = nilfs_btree_node_get_key(node, nchildren - 1);
1664 nextmaxkey = (nchildren > 1) ?
1665 nilfs_btree_node_get_key(node, nchildren - 2) : 0;
1666 if (bh != NULL)
1667 brelse(bh);
1668
1669 return (maxkey == key) && (nextmaxkey < NILFS_BMAP_LARGE_LOW);
1670 }
1671
1672 static int nilfs_btree_gather_data(struct nilfs_bmap *btree,
1673 __u64 *keys, __u64 *ptrs, int nitems)
1674 {
1675 struct buffer_head *bh;
1676 struct nilfs_btree_node *node, *root;
1677 __le64 *dkeys;
1678 __le64 *dptrs;
1679 __u64 ptr;
1680 int nchildren, ncmax, i, ret;
1681
1682 root = nilfs_btree_get_root(btree);
1683 switch (nilfs_btree_height(btree)) {
1684 case 2:
1685 bh = NULL;
1686 node = root;
1687 ncmax = NILFS_BTREE_ROOT_NCHILDREN_MAX;
1688 break;
1689 case 3:
1690 nchildren = nilfs_btree_node_get_nchildren(root);
1691 WARN_ON(nchildren > 1);
1692 ptr = nilfs_btree_node_get_ptr(root, nchildren - 1,
1693 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1694 ret = nilfs_btree_get_block(btree, ptr, &bh);
1695 if (ret < 0)
1696 return ret;
1697 node = (struct nilfs_btree_node *)bh->b_data;
1698 ncmax = nilfs_btree_nchildren_per_block(btree);
1699 break;
1700 default:
1701 node = NULL;
1702 return -EINVAL;
1703 }
1704
1705 nchildren = nilfs_btree_node_get_nchildren(node);
1706 if (nchildren < nitems)
1707 nitems = nchildren;
1708 dkeys = nilfs_btree_node_dkeys(node);
1709 dptrs = nilfs_btree_node_dptrs(node, ncmax);
1710 for (i = 0; i < nitems; i++) {
1711 keys[i] = le64_to_cpu(dkeys[i]);
1712 ptrs[i] = le64_to_cpu(dptrs[i]);
1713 }
1714
1715 if (bh != NULL)
1716 brelse(bh);
1717
1718 return nitems;
1719 }
1720
1721 static int
1722 nilfs_btree_prepare_convert_and_insert(struct nilfs_bmap *btree, __u64 key,
1723 union nilfs_bmap_ptr_req *dreq,
1724 union nilfs_bmap_ptr_req *nreq,
1725 struct buffer_head **bhp,
1726 struct nilfs_bmap_stats *stats)
1727 {
1728 struct buffer_head *bh;
1729 struct inode *dat = NULL;
1730 int ret;
1731
1732 stats->bs_nblocks = 0;
1733
1734 /* for data */
1735 /* cannot find near ptr */
1736 if (NILFS_BMAP_USE_VBN(btree)) {
1737 dreq->bpr_ptr = nilfs_btree_find_target_v(btree, NULL, key);
1738 dat = nilfs_bmap_get_dat(btree);
1739 }
1740
1741 ret = nilfs_bmap_prepare_alloc_ptr(btree, dreq, dat);
1742 if (ret < 0)
1743 return ret;
1744
1745 *bhp = NULL;
1746 stats->bs_nblocks++;
1747 if (nreq != NULL) {
1748 nreq->bpr_ptr = dreq->bpr_ptr + 1;
1749 ret = nilfs_bmap_prepare_alloc_ptr(btree, nreq, dat);
1750 if (ret < 0)
1751 goto err_out_dreq;
1752
1753 ret = nilfs_btree_get_new_block(btree, nreq->bpr_ptr, &bh);
1754 if (ret < 0)
1755 goto err_out_nreq;
1756
1757 *bhp = bh;
1758 stats->bs_nblocks++;
1759 }
1760
1761 /* success */
1762 return 0;
1763
1764 /* error */
1765 err_out_nreq:
1766 nilfs_bmap_abort_alloc_ptr(btree, nreq, dat);
1767 err_out_dreq:
1768 nilfs_bmap_abort_alloc_ptr(btree, dreq, dat);
1769 stats->bs_nblocks = 0;
1770 return ret;
1771
1772 }
1773
1774 static void
1775 nilfs_btree_commit_convert_and_insert(struct nilfs_bmap *btree,
1776 __u64 key, __u64 ptr,
1777 const __u64 *keys, const __u64 *ptrs,
1778 int n,
1779 union nilfs_bmap_ptr_req *dreq,
1780 union nilfs_bmap_ptr_req *nreq,
1781 struct buffer_head *bh)
1782 {
1783 struct nilfs_btree_node *node;
1784 struct inode *dat;
1785 __u64 tmpptr;
1786 int ncblk;
1787
1788 /* free resources */
1789 if (btree->b_ops->bop_clear != NULL)
1790 btree->b_ops->bop_clear(btree);
1791
1792 /* ptr must be a pointer to a buffer head. */
1793 set_buffer_nilfs_volatile((struct buffer_head *)((unsigned long)ptr));
1794
1795 /* convert and insert */
1796 dat = NILFS_BMAP_USE_VBN(btree) ? nilfs_bmap_get_dat(btree) : NULL;
1797 __nilfs_btree_init(btree);
1798 if (nreq != NULL) {
1799 nilfs_bmap_commit_alloc_ptr(btree, dreq, dat);
1800 nilfs_bmap_commit_alloc_ptr(btree, nreq, dat);
1801
1802 /* create child node at level 1 */
1803 node = (struct nilfs_btree_node *)bh->b_data;
1804 ncblk = nilfs_btree_nchildren_per_block(btree);
1805 nilfs_btree_node_init(node, 0, 1, n, ncblk, keys, ptrs);
1806 nilfs_btree_node_insert(node, n, key, dreq->bpr_ptr, ncblk);
1807 if (!buffer_dirty(bh))
1808 mark_buffer_dirty(bh);
1809 if (!nilfs_bmap_dirty(btree))
1810 nilfs_bmap_set_dirty(btree);
1811
1812 brelse(bh);
1813
1814 /* create root node at level 2 */
1815 node = nilfs_btree_get_root(btree);
1816 tmpptr = nreq->bpr_ptr;
1817 nilfs_btree_node_init(node, NILFS_BTREE_NODE_ROOT, 2, 1,
1818 NILFS_BTREE_ROOT_NCHILDREN_MAX,
1819 &keys[0], &tmpptr);
1820 } else {
1821 nilfs_bmap_commit_alloc_ptr(btree, dreq, dat);
1822
1823 /* create root node at level 1 */
1824 node = nilfs_btree_get_root(btree);
1825 nilfs_btree_node_init(node, NILFS_BTREE_NODE_ROOT, 1, n,
1826 NILFS_BTREE_ROOT_NCHILDREN_MAX,
1827 keys, ptrs);
1828 nilfs_btree_node_insert(node, n, key, dreq->bpr_ptr,
1829 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1830 if (!nilfs_bmap_dirty(btree))
1831 nilfs_bmap_set_dirty(btree);
1832 }
1833
1834 if (NILFS_BMAP_USE_VBN(btree))
1835 nilfs_bmap_set_target_v(btree, key, dreq->bpr_ptr);
1836 }
1837
1838 /**
1839 * nilfs_btree_convert_and_insert -
1840 * @bmap:
1841 * @key:
1842 * @ptr:
1843 * @keys:
1844 * @ptrs:
1845 * @n:
1846 */
1847 int nilfs_btree_convert_and_insert(struct nilfs_bmap *btree,
1848 __u64 key, __u64 ptr,
1849 const __u64 *keys, const __u64 *ptrs, int n)
1850 {
1851 struct buffer_head *bh = NULL;
1852 union nilfs_bmap_ptr_req dreq, nreq, *di, *ni;
1853 struct nilfs_bmap_stats stats;
1854 int ret;
1855
1856 if (n + 1 <= NILFS_BTREE_ROOT_NCHILDREN_MAX) {
1857 di = &dreq;
1858 ni = NULL;
1859 } else if ((n + 1) <= NILFS_BTREE_NODE_NCHILDREN_MAX(
1860 1 << btree->b_inode->i_blkbits)) {
1861 di = &dreq;
1862 ni = &nreq;
1863 } else {
1864 di = NULL;
1865 ni = NULL;
1866 BUG();
1867 }
1868
1869 ret = nilfs_btree_prepare_convert_and_insert(btree, key, di, ni, &bh,
1870 &stats);
1871 if (ret < 0)
1872 return ret;
1873 nilfs_btree_commit_convert_and_insert(btree, key, ptr, keys, ptrs, n,
1874 di, ni, bh);
1875 nilfs_inode_add_blocks(btree->b_inode, stats.bs_nblocks);
1876 return 0;
1877 }
1878
1879 static int nilfs_btree_propagate_p(struct nilfs_bmap *btree,
1880 struct nilfs_btree_path *path,
1881 int level,
1882 struct buffer_head *bh)
1883 {
1884 while ((++level < nilfs_btree_height(btree) - 1) &&
1885 !buffer_dirty(path[level].bp_bh))
1886 mark_buffer_dirty(path[level].bp_bh);
1887
1888 return 0;
1889 }
1890
1891 static int nilfs_btree_prepare_update_v(struct nilfs_bmap *btree,
1892 struct nilfs_btree_path *path,
1893 int level, struct inode *dat)
1894 {
1895 struct nilfs_btree_node *parent;
1896 int ncmax, ret;
1897
1898 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
1899 path[level].bp_oldreq.bpr_ptr =
1900 nilfs_btree_node_get_ptr(parent, path[level + 1].bp_index,
1901 ncmax);
1902 path[level].bp_newreq.bpr_ptr = path[level].bp_oldreq.bpr_ptr + 1;
1903 ret = nilfs_dat_prepare_update(dat, &path[level].bp_oldreq.bpr_req,
1904 &path[level].bp_newreq.bpr_req);
1905 if (ret < 0)
1906 return ret;
1907
1908 if (buffer_nilfs_node(path[level].bp_bh)) {
1909 path[level].bp_ctxt.oldkey = path[level].bp_oldreq.bpr_ptr;
1910 path[level].bp_ctxt.newkey = path[level].bp_newreq.bpr_ptr;
1911 path[level].bp_ctxt.bh = path[level].bp_bh;
1912 ret = nilfs_btnode_prepare_change_key(
1913 &NILFS_BMAP_I(btree)->i_btnode_cache,
1914 &path[level].bp_ctxt);
1915 if (ret < 0) {
1916 nilfs_dat_abort_update(dat,
1917 &path[level].bp_oldreq.bpr_req,
1918 &path[level].bp_newreq.bpr_req);
1919 return ret;
1920 }
1921 }
1922
1923 return 0;
1924 }
1925
1926 static void nilfs_btree_commit_update_v(struct nilfs_bmap *btree,
1927 struct nilfs_btree_path *path,
1928 int level, struct inode *dat)
1929 {
1930 struct nilfs_btree_node *parent;
1931 int ncmax;
1932
1933 nilfs_dat_commit_update(dat, &path[level].bp_oldreq.bpr_req,
1934 &path[level].bp_newreq.bpr_req,
1935 btree->b_ptr_type == NILFS_BMAP_PTR_VS);
1936
1937 if (buffer_nilfs_node(path[level].bp_bh)) {
1938 nilfs_btnode_commit_change_key(
1939 &NILFS_BMAP_I(btree)->i_btnode_cache,
1940 &path[level].bp_ctxt);
1941 path[level].bp_bh = path[level].bp_ctxt.bh;
1942 }
1943 set_buffer_nilfs_volatile(path[level].bp_bh);
1944
1945 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
1946 nilfs_btree_node_set_ptr(parent, path[level + 1].bp_index,
1947 path[level].bp_newreq.bpr_ptr, ncmax);
1948 }
1949
1950 static void nilfs_btree_abort_update_v(struct nilfs_bmap *btree,
1951 struct nilfs_btree_path *path,
1952 int level, struct inode *dat)
1953 {
1954 nilfs_dat_abort_update(dat, &path[level].bp_oldreq.bpr_req,
1955 &path[level].bp_newreq.bpr_req);
1956 if (buffer_nilfs_node(path[level].bp_bh))
1957 nilfs_btnode_abort_change_key(
1958 &NILFS_BMAP_I(btree)->i_btnode_cache,
1959 &path[level].bp_ctxt);
1960 }
1961
1962 static int nilfs_btree_prepare_propagate_v(struct nilfs_bmap *btree,
1963 struct nilfs_btree_path *path,
1964 int minlevel, int *maxlevelp,
1965 struct inode *dat)
1966 {
1967 int level, ret;
1968
1969 level = minlevel;
1970 if (!buffer_nilfs_volatile(path[level].bp_bh)) {
1971 ret = nilfs_btree_prepare_update_v(btree, path, level, dat);
1972 if (ret < 0)
1973 return ret;
1974 }
1975 while ((++level < nilfs_btree_height(btree) - 1) &&
1976 !buffer_dirty(path[level].bp_bh)) {
1977
1978 WARN_ON(buffer_nilfs_volatile(path[level].bp_bh));
1979 ret = nilfs_btree_prepare_update_v(btree, path, level, dat);
1980 if (ret < 0)
1981 goto out;
1982 }
1983
1984 /* success */
1985 *maxlevelp = level - 1;
1986 return 0;
1987
1988 /* error */
1989 out:
1990 while (--level > minlevel)
1991 nilfs_btree_abort_update_v(btree, path, level, dat);
1992 if (!buffer_nilfs_volatile(path[level].bp_bh))
1993 nilfs_btree_abort_update_v(btree, path, level, dat);
1994 return ret;
1995 }
1996
1997 static void nilfs_btree_commit_propagate_v(struct nilfs_bmap *btree,
1998 struct nilfs_btree_path *path,
1999 int minlevel, int maxlevel,
2000 struct buffer_head *bh,
2001 struct inode *dat)
2002 {
2003 int level;
2004
2005 if (!buffer_nilfs_volatile(path[minlevel].bp_bh))
2006 nilfs_btree_commit_update_v(btree, path, minlevel, dat);
2007
2008 for (level = minlevel + 1; level <= maxlevel; level++)
2009 nilfs_btree_commit_update_v(btree, path, level, dat);
2010 }
2011
2012 static int nilfs_btree_propagate_v(struct nilfs_bmap *btree,
2013 struct nilfs_btree_path *path,
2014 int level, struct buffer_head *bh)
2015 {
2016 int maxlevel = 0, ret;
2017 struct nilfs_btree_node *parent;
2018 struct inode *dat = nilfs_bmap_get_dat(btree);
2019 __u64 ptr;
2020 int ncmax;
2021
2022 get_bh(bh);
2023 path[level].bp_bh = bh;
2024 ret = nilfs_btree_prepare_propagate_v(btree, path, level, &maxlevel,
2025 dat);
2026 if (ret < 0)
2027 goto out;
2028
2029 if (buffer_nilfs_volatile(path[level].bp_bh)) {
2030 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
2031 ptr = nilfs_btree_node_get_ptr(parent,
2032 path[level + 1].bp_index,
2033 ncmax);
2034 ret = nilfs_dat_mark_dirty(dat, ptr);
2035 if (ret < 0)
2036 goto out;
2037 }
2038
2039 nilfs_btree_commit_propagate_v(btree, path, level, maxlevel, bh, dat);
2040
2041 out:
2042 brelse(path[level].bp_bh);
2043 path[level].bp_bh = NULL;
2044 return ret;
2045 }
2046
2047 static int nilfs_btree_propagate(struct nilfs_bmap *btree,
2048 struct buffer_head *bh)
2049 {
2050 struct nilfs_btree_path *path;
2051 struct nilfs_btree_node *node;
2052 __u64 key;
2053 int level, ret;
2054
2055 WARN_ON(!buffer_dirty(bh));
2056
2057 path = nilfs_btree_alloc_path();
2058 if (path == NULL)
2059 return -ENOMEM;
2060
2061 if (buffer_nilfs_node(bh)) {
2062 node = (struct nilfs_btree_node *)bh->b_data;
2063 key = nilfs_btree_node_get_key(node, 0);
2064 level = nilfs_btree_node_get_level(node);
2065 } else {
2066 key = nilfs_bmap_data_get_key(btree, bh);
2067 level = NILFS_BTREE_LEVEL_DATA;
2068 }
2069
2070 ret = nilfs_btree_do_lookup(btree, path, key, NULL, level + 1, 0);
2071 if (ret < 0) {
2072 if (unlikely(ret == -ENOENT))
2073 printk(KERN_CRIT "%s: key = %llu, level == %d\n",
2074 __func__, (unsigned long long)key, level);
2075 goto out;
2076 }
2077
2078 ret = NILFS_BMAP_USE_VBN(btree) ?
2079 nilfs_btree_propagate_v(btree, path, level, bh) :
2080 nilfs_btree_propagate_p(btree, path, level, bh);
2081
2082 out:
2083 nilfs_btree_free_path(path);
2084
2085 return ret;
2086 }
2087
2088 static int nilfs_btree_propagate_gc(struct nilfs_bmap *btree,
2089 struct buffer_head *bh)
2090 {
2091 return nilfs_dat_mark_dirty(nilfs_bmap_get_dat(btree), bh->b_blocknr);
2092 }
2093
2094 static void nilfs_btree_add_dirty_buffer(struct nilfs_bmap *btree,
2095 struct list_head *lists,
2096 struct buffer_head *bh)
2097 {
2098 struct list_head *head;
2099 struct buffer_head *cbh;
2100 struct nilfs_btree_node *node, *cnode;
2101 __u64 key, ckey;
2102 int level;
2103
2104 get_bh(bh);
2105 node = (struct nilfs_btree_node *)bh->b_data;
2106 key = nilfs_btree_node_get_key(node, 0);
2107 level = nilfs_btree_node_get_level(node);
2108 if (level < NILFS_BTREE_LEVEL_NODE_MIN ||
2109 level >= NILFS_BTREE_LEVEL_MAX) {
2110 dump_stack();
2111 printk(KERN_WARNING
2112 "%s: invalid btree level: %d (key=%llu, ino=%lu, "
2113 "blocknr=%llu)\n",
2114 __func__, level, (unsigned long long)key,
2115 NILFS_BMAP_I(btree)->vfs_inode.i_ino,
2116 (unsigned long long)bh->b_blocknr);
2117 return;
2118 }
2119
2120 list_for_each(head, &lists[level]) {
2121 cbh = list_entry(head, struct buffer_head, b_assoc_buffers);
2122 cnode = (struct nilfs_btree_node *)cbh->b_data;
2123 ckey = nilfs_btree_node_get_key(cnode, 0);
2124 if (key < ckey)
2125 break;
2126 }
2127 list_add_tail(&bh->b_assoc_buffers, head);
2128 }
2129
2130 static void nilfs_btree_lookup_dirty_buffers(struct nilfs_bmap *btree,
2131 struct list_head *listp)
2132 {
2133 struct address_space *btcache = &NILFS_BMAP_I(btree)->i_btnode_cache;
2134 struct list_head lists[NILFS_BTREE_LEVEL_MAX];
2135 struct pagevec pvec;
2136 struct buffer_head *bh, *head;
2137 pgoff_t index = 0;
2138 int level, i;
2139
2140 for (level = NILFS_BTREE_LEVEL_NODE_MIN;
2141 level < NILFS_BTREE_LEVEL_MAX;
2142 level++)
2143 INIT_LIST_HEAD(&lists[level]);
2144
2145 pagevec_init(&pvec, 0);
2146
2147 while (pagevec_lookup_tag(&pvec, btcache, &index, PAGECACHE_TAG_DIRTY,
2148 PAGEVEC_SIZE)) {
2149 for (i = 0; i < pagevec_count(&pvec); i++) {
2150 bh = head = page_buffers(pvec.pages[i]);
2151 do {
2152 if (buffer_dirty(bh))
2153 nilfs_btree_add_dirty_buffer(btree,
2154 lists, bh);
2155 } while ((bh = bh->b_this_page) != head);
2156 }
2157 pagevec_release(&pvec);
2158 cond_resched();
2159 }
2160
2161 for (level = NILFS_BTREE_LEVEL_NODE_MIN;
2162 level < NILFS_BTREE_LEVEL_MAX;
2163 level++)
2164 list_splice_tail(&lists[level], listp);
2165 }
2166
2167 static int nilfs_btree_assign_p(struct nilfs_bmap *btree,
2168 struct nilfs_btree_path *path,
2169 int level,
2170 struct buffer_head **bh,
2171 sector_t blocknr,
2172 union nilfs_binfo *binfo)
2173 {
2174 struct nilfs_btree_node *parent;
2175 __u64 key;
2176 __u64 ptr;
2177 int ncmax, ret;
2178
2179 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
2180 ptr = nilfs_btree_node_get_ptr(parent, path[level + 1].bp_index,
2181 ncmax);
2182 if (buffer_nilfs_node(*bh)) {
2183 path[level].bp_ctxt.oldkey = ptr;
2184 path[level].bp_ctxt.newkey = blocknr;
2185 path[level].bp_ctxt.bh = *bh;
2186 ret = nilfs_btnode_prepare_change_key(
2187 &NILFS_BMAP_I(btree)->i_btnode_cache,
2188 &path[level].bp_ctxt);
2189 if (ret < 0)
2190 return ret;
2191 nilfs_btnode_commit_change_key(
2192 &NILFS_BMAP_I(btree)->i_btnode_cache,
2193 &path[level].bp_ctxt);
2194 *bh = path[level].bp_ctxt.bh;
2195 }
2196
2197 nilfs_btree_node_set_ptr(parent, path[level + 1].bp_index, blocknr,
2198 ncmax);
2199
2200 key = nilfs_btree_node_get_key(parent, path[level + 1].bp_index);
2201 /* on-disk format */
2202 binfo->bi_dat.bi_blkoff = cpu_to_le64(key);
2203 binfo->bi_dat.bi_level = level;
2204
2205 return 0;
2206 }
2207
2208 static int nilfs_btree_assign_v(struct nilfs_bmap *btree,
2209 struct nilfs_btree_path *path,
2210 int level,
2211 struct buffer_head **bh,
2212 sector_t blocknr,
2213 union nilfs_binfo *binfo)
2214 {
2215 struct nilfs_btree_node *parent;
2216 struct inode *dat = nilfs_bmap_get_dat(btree);
2217 __u64 key;
2218 __u64 ptr;
2219 union nilfs_bmap_ptr_req req;
2220 int ncmax, ret;
2221
2222 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
2223 ptr = nilfs_btree_node_get_ptr(parent, path[level + 1].bp_index,
2224 ncmax);
2225 req.bpr_ptr = ptr;
2226 ret = nilfs_dat_prepare_start(dat, &req.bpr_req);
2227 if (ret < 0)
2228 return ret;
2229 nilfs_dat_commit_start(dat, &req.bpr_req, blocknr);
2230
2231 key = nilfs_btree_node_get_key(parent, path[level + 1].bp_index);
2232 /* on-disk format */
2233 binfo->bi_v.bi_vblocknr = cpu_to_le64(ptr);
2234 binfo->bi_v.bi_blkoff = cpu_to_le64(key);
2235
2236 return 0;
2237 }
2238
2239 static int nilfs_btree_assign(struct nilfs_bmap *btree,
2240 struct buffer_head **bh,
2241 sector_t blocknr,
2242 union nilfs_binfo *binfo)
2243 {
2244 struct nilfs_btree_path *path;
2245 struct nilfs_btree_node *node;
2246 __u64 key;
2247 int level, ret;
2248
2249 path = nilfs_btree_alloc_path();
2250 if (path == NULL)
2251 return -ENOMEM;
2252
2253 if (buffer_nilfs_node(*bh)) {
2254 node = (struct nilfs_btree_node *)(*bh)->b_data;
2255 key = nilfs_btree_node_get_key(node, 0);
2256 level = nilfs_btree_node_get_level(node);
2257 } else {
2258 key = nilfs_bmap_data_get_key(btree, *bh);
2259 level = NILFS_BTREE_LEVEL_DATA;
2260 }
2261
2262 ret = nilfs_btree_do_lookup(btree, path, key, NULL, level + 1, 0);
2263 if (ret < 0) {
2264 WARN_ON(ret == -ENOENT);
2265 goto out;
2266 }
2267
2268 ret = NILFS_BMAP_USE_VBN(btree) ?
2269 nilfs_btree_assign_v(btree, path, level, bh, blocknr, binfo) :
2270 nilfs_btree_assign_p(btree, path, level, bh, blocknr, binfo);
2271
2272 out:
2273 nilfs_btree_free_path(path);
2274
2275 return ret;
2276 }
2277
2278 static int nilfs_btree_assign_gc(struct nilfs_bmap *btree,
2279 struct buffer_head **bh,
2280 sector_t blocknr,
2281 union nilfs_binfo *binfo)
2282 {
2283 struct nilfs_btree_node *node;
2284 __u64 key;
2285 int ret;
2286
2287 ret = nilfs_dat_move(nilfs_bmap_get_dat(btree), (*bh)->b_blocknr,
2288 blocknr);
2289 if (ret < 0)
2290 return ret;
2291
2292 if (buffer_nilfs_node(*bh)) {
2293 node = (struct nilfs_btree_node *)(*bh)->b_data;
2294 key = nilfs_btree_node_get_key(node, 0);
2295 } else
2296 key = nilfs_bmap_data_get_key(btree, *bh);
2297
2298 /* on-disk format */
2299 binfo->bi_v.bi_vblocknr = cpu_to_le64((*bh)->b_blocknr);
2300 binfo->bi_v.bi_blkoff = cpu_to_le64(key);
2301
2302 return 0;
2303 }
2304
2305 static int nilfs_btree_mark(struct nilfs_bmap *btree, __u64 key, int level)
2306 {
2307 struct buffer_head *bh;
2308 struct nilfs_btree_path *path;
2309 __u64 ptr;
2310 int ret;
2311
2312 path = nilfs_btree_alloc_path();
2313 if (path == NULL)
2314 return -ENOMEM;
2315
2316 ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level + 1, 0);
2317 if (ret < 0) {
2318 WARN_ON(ret == -ENOENT);
2319 goto out;
2320 }
2321 ret = nilfs_btree_get_block(btree, ptr, &bh);
2322 if (ret < 0) {
2323 WARN_ON(ret == -ENOENT);
2324 goto out;
2325 }
2326
2327 if (!buffer_dirty(bh))
2328 mark_buffer_dirty(bh);
2329 brelse(bh);
2330 if (!nilfs_bmap_dirty(btree))
2331 nilfs_bmap_set_dirty(btree);
2332
2333 out:
2334 nilfs_btree_free_path(path);
2335 return ret;
2336 }
2337
2338 static const struct nilfs_bmap_operations nilfs_btree_ops = {
2339 .bop_lookup = nilfs_btree_lookup,
2340 .bop_lookup_contig = nilfs_btree_lookup_contig,
2341 .bop_insert = nilfs_btree_insert,
2342 .bop_delete = nilfs_btree_delete,
2343 .bop_clear = NULL,
2344
2345 .bop_propagate = nilfs_btree_propagate,
2346
2347 .bop_lookup_dirty_buffers = nilfs_btree_lookup_dirty_buffers,
2348
2349 .bop_assign = nilfs_btree_assign,
2350 .bop_mark = nilfs_btree_mark,
2351
2352 .bop_seek_key = nilfs_btree_seek_key,
2353 .bop_last_key = nilfs_btree_last_key,
2354
2355 .bop_check_insert = NULL,
2356 .bop_check_delete = nilfs_btree_check_delete,
2357 .bop_gather_data = nilfs_btree_gather_data,
2358 };
2359
2360 static const struct nilfs_bmap_operations nilfs_btree_ops_gc = {
2361 .bop_lookup = NULL,
2362 .bop_lookup_contig = NULL,
2363 .bop_insert = NULL,
2364 .bop_delete = NULL,
2365 .bop_clear = NULL,
2366
2367 .bop_propagate = nilfs_btree_propagate_gc,
2368
2369 .bop_lookup_dirty_buffers = nilfs_btree_lookup_dirty_buffers,
2370
2371 .bop_assign = nilfs_btree_assign_gc,
2372 .bop_mark = NULL,
2373
2374 .bop_seek_key = NULL,
2375 .bop_last_key = NULL,
2376
2377 .bop_check_insert = NULL,
2378 .bop_check_delete = NULL,
2379 .bop_gather_data = NULL,
2380 };
2381
2382 static void __nilfs_btree_init(struct nilfs_bmap *bmap)
2383 {
2384 bmap->b_ops = &nilfs_btree_ops;
2385 bmap->b_nchildren_per_block =
2386 NILFS_BTREE_NODE_NCHILDREN_MAX(nilfs_btree_node_size(bmap));
2387 }
2388
2389 int nilfs_btree_init(struct nilfs_bmap *bmap)
2390 {
2391 int ret = 0;
2392
2393 __nilfs_btree_init(bmap);
2394
2395 if (nilfs_btree_root_broken(nilfs_btree_get_root(bmap),
2396 bmap->b_inode->i_ino))
2397 ret = -EIO;
2398 return ret;
2399 }
2400
2401 void nilfs_btree_init_gc(struct nilfs_bmap *bmap)
2402 {
2403 bmap->b_ops = &nilfs_btree_ops_gc;
2404 bmap->b_nchildren_per_block =
2405 NILFS_BTREE_NODE_NCHILDREN_MAX(nilfs_btree_node_size(bmap));
2406 }
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