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Merge tag 'clk-for-linus-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/clk...
[deliverable/linux.git] / fs / nilfs2 / btree.c
1 /*
2 * btree.c - NILFS B-tree.
3 *
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * 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, REQ_OP_READ, 0, &bh,
480 &submit_ptr);
481 if (ret) {
482 if (ret != -EEXIST)
483 return ret;
484 goto out_check;
485 }
486
487 if (ra) {
488 int i, n;
489 __u64 ptr2;
490
491 /* read ahead sibling nodes */
492 for (n = ra->max_ra_blocks, i = ra->index + 1;
493 n > 0 && i < ra->ncmax; n--, i++) {
494 ptr2 = nilfs_btree_node_get_ptr(ra->node, i, ra->ncmax);
495
496 ret = nilfs_btnode_submit_block(btnc, ptr2, 0,
497 REQ_OP_READ, REQ_RAHEAD,
498 &ra_bh, &submit_ptr);
499 if (likely(!ret || ret == -EEXIST))
500 brelse(ra_bh);
501 else if (ret != -EBUSY)
502 break;
503 if (!buffer_locked(bh))
504 goto out_no_wait;
505 }
506 }
507
508 wait_on_buffer(bh);
509
510 out_no_wait:
511 if (!buffer_uptodate(bh)) {
512 brelse(bh);
513 return -EIO;
514 }
515
516 out_check:
517 if (nilfs_btree_broken_node_block(bh)) {
518 clear_buffer_uptodate(bh);
519 brelse(bh);
520 return -EINVAL;
521 }
522
523 *bhp = bh;
524 return 0;
525 }
526
527 static int nilfs_btree_get_block(const struct nilfs_bmap *btree, __u64 ptr,
528 struct buffer_head **bhp)
529 {
530 return __nilfs_btree_get_block(btree, ptr, bhp, NULL);
531 }
532
533 static int nilfs_btree_do_lookup(const struct nilfs_bmap *btree,
534 struct nilfs_btree_path *path,
535 __u64 key, __u64 *ptrp, int minlevel,
536 int readahead)
537 {
538 struct nilfs_btree_node *node;
539 struct nilfs_btree_readahead_info p, *ra;
540 __u64 ptr;
541 int level, index, found, ncmax, ret;
542
543 node = nilfs_btree_get_root(btree);
544 level = nilfs_btree_node_get_level(node);
545 if (level < minlevel || nilfs_btree_node_get_nchildren(node) <= 0)
546 return -ENOENT;
547
548 found = nilfs_btree_node_lookup(node, key, &index);
549 ptr = nilfs_btree_node_get_ptr(node, index,
550 NILFS_BTREE_ROOT_NCHILDREN_MAX);
551 path[level].bp_bh = NULL;
552 path[level].bp_index = index;
553
554 ncmax = nilfs_btree_nchildren_per_block(btree);
555
556 while (--level >= minlevel) {
557 ra = NULL;
558 if (level == NILFS_BTREE_LEVEL_NODE_MIN && readahead) {
559 p.node = nilfs_btree_get_node(btree, path, level + 1,
560 &p.ncmax);
561 p.index = index;
562 p.max_ra_blocks = 7;
563 ra = &p;
564 }
565 ret = __nilfs_btree_get_block(btree, ptr, &path[level].bp_bh,
566 ra);
567 if (ret < 0)
568 return ret;
569
570 node = nilfs_btree_get_nonroot_node(path, level);
571 if (nilfs_btree_bad_node(node, level))
572 return -EINVAL;
573 if (!found)
574 found = nilfs_btree_node_lookup(node, key, &index);
575 else
576 index = 0;
577 if (index < ncmax) {
578 ptr = nilfs_btree_node_get_ptr(node, index, ncmax);
579 } else {
580 WARN_ON(found || level != NILFS_BTREE_LEVEL_NODE_MIN);
581 /* insert */
582 ptr = NILFS_BMAP_INVALID_PTR;
583 }
584 path[level].bp_index = index;
585 }
586 if (!found)
587 return -ENOENT;
588
589 if (ptrp != NULL)
590 *ptrp = ptr;
591
592 return 0;
593 }
594
595 static int nilfs_btree_do_lookup_last(const struct nilfs_bmap *btree,
596 struct nilfs_btree_path *path,
597 __u64 *keyp, __u64 *ptrp)
598 {
599 struct nilfs_btree_node *node;
600 __u64 ptr;
601 int index, level, ncmax, ret;
602
603 node = nilfs_btree_get_root(btree);
604 index = nilfs_btree_node_get_nchildren(node) - 1;
605 if (index < 0)
606 return -ENOENT;
607 level = nilfs_btree_node_get_level(node);
608 ptr = nilfs_btree_node_get_ptr(node, index,
609 NILFS_BTREE_ROOT_NCHILDREN_MAX);
610 path[level].bp_bh = NULL;
611 path[level].bp_index = index;
612 ncmax = nilfs_btree_nchildren_per_block(btree);
613
614 for (level--; level > 0; level--) {
615 ret = nilfs_btree_get_block(btree, ptr, &path[level].bp_bh);
616 if (ret < 0)
617 return ret;
618 node = nilfs_btree_get_nonroot_node(path, level);
619 if (nilfs_btree_bad_node(node, level))
620 return -EINVAL;
621 index = nilfs_btree_node_get_nchildren(node) - 1;
622 ptr = nilfs_btree_node_get_ptr(node, index, ncmax);
623 path[level].bp_index = index;
624 }
625
626 if (keyp != NULL)
627 *keyp = nilfs_btree_node_get_key(node, index);
628 if (ptrp != NULL)
629 *ptrp = ptr;
630
631 return 0;
632 }
633
634 /**
635 * nilfs_btree_get_next_key - get next valid key from btree path array
636 * @btree: bmap struct of btree
637 * @path: array of nilfs_btree_path struct
638 * @minlevel: start level
639 * @nextkey: place to store the next valid key
640 *
641 * Return Value: If a next key was found, 0 is returned. Otherwise,
642 * -ENOENT is returned.
643 */
644 static int nilfs_btree_get_next_key(const struct nilfs_bmap *btree,
645 const struct nilfs_btree_path *path,
646 int minlevel, __u64 *nextkey)
647 {
648 struct nilfs_btree_node *node;
649 int maxlevel = nilfs_btree_height(btree) - 1;
650 int index, next_adj, level;
651
652 /* Next index is already set to bp_index for leaf nodes. */
653 next_adj = 0;
654 for (level = minlevel; level <= maxlevel; level++) {
655 if (level == maxlevel)
656 node = nilfs_btree_get_root(btree);
657 else
658 node = nilfs_btree_get_nonroot_node(path, level);
659
660 index = path[level].bp_index + next_adj;
661 if (index < nilfs_btree_node_get_nchildren(node)) {
662 /* Next key is in this node */
663 *nextkey = nilfs_btree_node_get_key(node, index);
664 return 0;
665 }
666 /* For non-leaf nodes, next index is stored at bp_index + 1. */
667 next_adj = 1;
668 }
669 return -ENOENT;
670 }
671
672 static int nilfs_btree_lookup(const struct nilfs_bmap *btree,
673 __u64 key, int level, __u64 *ptrp)
674 {
675 struct nilfs_btree_path *path;
676 int ret;
677
678 path = nilfs_btree_alloc_path();
679 if (path == NULL)
680 return -ENOMEM;
681
682 ret = nilfs_btree_do_lookup(btree, path, key, ptrp, level, 0);
683
684 nilfs_btree_free_path(path);
685
686 return ret;
687 }
688
689 static int nilfs_btree_lookup_contig(const struct nilfs_bmap *btree,
690 __u64 key, __u64 *ptrp,
691 unsigned int maxblocks)
692 {
693 struct nilfs_btree_path *path;
694 struct nilfs_btree_node *node;
695 struct inode *dat = NULL;
696 __u64 ptr, ptr2;
697 sector_t blocknr;
698 int level = NILFS_BTREE_LEVEL_NODE_MIN;
699 int ret, cnt, index, maxlevel, ncmax;
700 struct nilfs_btree_readahead_info p;
701
702 path = nilfs_btree_alloc_path();
703 if (path == NULL)
704 return -ENOMEM;
705
706 ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level, 1);
707 if (ret < 0)
708 goto out;
709
710 if (NILFS_BMAP_USE_VBN(btree)) {
711 dat = nilfs_bmap_get_dat(btree);
712 ret = nilfs_dat_translate(dat, ptr, &blocknr);
713 if (ret < 0)
714 goto out;
715 ptr = blocknr;
716 }
717 cnt = 1;
718 if (cnt == maxblocks)
719 goto end;
720
721 maxlevel = nilfs_btree_height(btree) - 1;
722 node = nilfs_btree_get_node(btree, path, level, &ncmax);
723 index = path[level].bp_index + 1;
724 for (;;) {
725 while (index < nilfs_btree_node_get_nchildren(node)) {
726 if (nilfs_btree_node_get_key(node, index) !=
727 key + cnt)
728 goto end;
729 ptr2 = nilfs_btree_node_get_ptr(node, index, ncmax);
730 if (dat) {
731 ret = nilfs_dat_translate(dat, ptr2, &blocknr);
732 if (ret < 0)
733 goto out;
734 ptr2 = blocknr;
735 }
736 if (ptr2 != ptr + cnt || ++cnt == maxblocks)
737 goto end;
738 index++;
739 continue;
740 }
741 if (level == maxlevel)
742 break;
743
744 /* look-up right sibling node */
745 p.node = nilfs_btree_get_node(btree, path, level + 1, &p.ncmax);
746 p.index = path[level + 1].bp_index + 1;
747 p.max_ra_blocks = 7;
748 if (p.index >= nilfs_btree_node_get_nchildren(p.node) ||
749 nilfs_btree_node_get_key(p.node, p.index) != key + cnt)
750 break;
751 ptr2 = nilfs_btree_node_get_ptr(p.node, p.index, p.ncmax);
752 path[level + 1].bp_index = p.index;
753
754 brelse(path[level].bp_bh);
755 path[level].bp_bh = NULL;
756
757 ret = __nilfs_btree_get_block(btree, ptr2, &path[level].bp_bh,
758 &p);
759 if (ret < 0)
760 goto out;
761 node = nilfs_btree_get_nonroot_node(path, level);
762 ncmax = nilfs_btree_nchildren_per_block(btree);
763 index = 0;
764 path[level].bp_index = index;
765 }
766 end:
767 *ptrp = ptr;
768 ret = cnt;
769 out:
770 nilfs_btree_free_path(path);
771 return ret;
772 }
773
774 static void nilfs_btree_promote_key(struct nilfs_bmap *btree,
775 struct nilfs_btree_path *path,
776 int level, __u64 key)
777 {
778 if (level < nilfs_btree_height(btree) - 1) {
779 do {
780 nilfs_btree_node_set_key(
781 nilfs_btree_get_nonroot_node(path, level),
782 path[level].bp_index, key);
783 if (!buffer_dirty(path[level].bp_bh))
784 mark_buffer_dirty(path[level].bp_bh);
785 } while ((path[level].bp_index == 0) &&
786 (++level < nilfs_btree_height(btree) - 1));
787 }
788
789 /* root */
790 if (level == nilfs_btree_height(btree) - 1) {
791 nilfs_btree_node_set_key(nilfs_btree_get_root(btree),
792 path[level].bp_index, key);
793 }
794 }
795
796 static void nilfs_btree_do_insert(struct nilfs_bmap *btree,
797 struct nilfs_btree_path *path,
798 int level, __u64 *keyp, __u64 *ptrp)
799 {
800 struct nilfs_btree_node *node;
801 int ncblk;
802
803 if (level < nilfs_btree_height(btree) - 1) {
804 node = nilfs_btree_get_nonroot_node(path, level);
805 ncblk = nilfs_btree_nchildren_per_block(btree);
806 nilfs_btree_node_insert(node, path[level].bp_index,
807 *keyp, *ptrp, ncblk);
808 if (!buffer_dirty(path[level].bp_bh))
809 mark_buffer_dirty(path[level].bp_bh);
810
811 if (path[level].bp_index == 0)
812 nilfs_btree_promote_key(btree, path, level + 1,
813 nilfs_btree_node_get_key(node,
814 0));
815 } else {
816 node = nilfs_btree_get_root(btree);
817 nilfs_btree_node_insert(node, path[level].bp_index,
818 *keyp, *ptrp,
819 NILFS_BTREE_ROOT_NCHILDREN_MAX);
820 }
821 }
822
823 static void nilfs_btree_carry_left(struct nilfs_bmap *btree,
824 struct nilfs_btree_path *path,
825 int level, __u64 *keyp, __u64 *ptrp)
826 {
827 struct nilfs_btree_node *node, *left;
828 int nchildren, lnchildren, n, move, ncblk;
829
830 node = nilfs_btree_get_nonroot_node(path, level);
831 left = nilfs_btree_get_sib_node(path, level);
832 nchildren = nilfs_btree_node_get_nchildren(node);
833 lnchildren = nilfs_btree_node_get_nchildren(left);
834 ncblk = nilfs_btree_nchildren_per_block(btree);
835 move = 0;
836
837 n = (nchildren + lnchildren + 1) / 2 - lnchildren;
838 if (n > path[level].bp_index) {
839 /* move insert point */
840 n--;
841 move = 1;
842 }
843
844 nilfs_btree_node_move_left(left, node, n, ncblk, ncblk);
845
846 if (!buffer_dirty(path[level].bp_bh))
847 mark_buffer_dirty(path[level].bp_bh);
848 if (!buffer_dirty(path[level].bp_sib_bh))
849 mark_buffer_dirty(path[level].bp_sib_bh);
850
851 nilfs_btree_promote_key(btree, path, level + 1,
852 nilfs_btree_node_get_key(node, 0));
853
854 if (move) {
855 brelse(path[level].bp_bh);
856 path[level].bp_bh = path[level].bp_sib_bh;
857 path[level].bp_sib_bh = NULL;
858 path[level].bp_index += lnchildren;
859 path[level + 1].bp_index--;
860 } else {
861 brelse(path[level].bp_sib_bh);
862 path[level].bp_sib_bh = NULL;
863 path[level].bp_index -= n;
864 }
865
866 nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
867 }
868
869 static void nilfs_btree_carry_right(struct nilfs_bmap *btree,
870 struct nilfs_btree_path *path,
871 int level, __u64 *keyp, __u64 *ptrp)
872 {
873 struct nilfs_btree_node *node, *right;
874 int nchildren, rnchildren, n, move, ncblk;
875
876 node = nilfs_btree_get_nonroot_node(path, level);
877 right = nilfs_btree_get_sib_node(path, level);
878 nchildren = nilfs_btree_node_get_nchildren(node);
879 rnchildren = nilfs_btree_node_get_nchildren(right);
880 ncblk = nilfs_btree_nchildren_per_block(btree);
881 move = 0;
882
883 n = (nchildren + rnchildren + 1) / 2 - rnchildren;
884 if (n > nchildren - path[level].bp_index) {
885 /* move insert point */
886 n--;
887 move = 1;
888 }
889
890 nilfs_btree_node_move_right(node, right, n, ncblk, ncblk);
891
892 if (!buffer_dirty(path[level].bp_bh))
893 mark_buffer_dirty(path[level].bp_bh);
894 if (!buffer_dirty(path[level].bp_sib_bh))
895 mark_buffer_dirty(path[level].bp_sib_bh);
896
897 path[level + 1].bp_index++;
898 nilfs_btree_promote_key(btree, path, level + 1,
899 nilfs_btree_node_get_key(right, 0));
900 path[level + 1].bp_index--;
901
902 if (move) {
903 brelse(path[level].bp_bh);
904 path[level].bp_bh = path[level].bp_sib_bh;
905 path[level].bp_sib_bh = NULL;
906 path[level].bp_index -= nilfs_btree_node_get_nchildren(node);
907 path[level + 1].bp_index++;
908 } else {
909 brelse(path[level].bp_sib_bh);
910 path[level].bp_sib_bh = NULL;
911 }
912
913 nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
914 }
915
916 static void nilfs_btree_split(struct nilfs_bmap *btree,
917 struct nilfs_btree_path *path,
918 int level, __u64 *keyp, __u64 *ptrp)
919 {
920 struct nilfs_btree_node *node, *right;
921 int nchildren, n, move, ncblk;
922
923 node = nilfs_btree_get_nonroot_node(path, level);
924 right = nilfs_btree_get_sib_node(path, level);
925 nchildren = nilfs_btree_node_get_nchildren(node);
926 ncblk = nilfs_btree_nchildren_per_block(btree);
927 move = 0;
928
929 n = (nchildren + 1) / 2;
930 if (n > nchildren - path[level].bp_index) {
931 n--;
932 move = 1;
933 }
934
935 nilfs_btree_node_move_right(node, right, n, ncblk, ncblk);
936
937 if (!buffer_dirty(path[level].bp_bh))
938 mark_buffer_dirty(path[level].bp_bh);
939 if (!buffer_dirty(path[level].bp_sib_bh))
940 mark_buffer_dirty(path[level].bp_sib_bh);
941
942 if (move) {
943 path[level].bp_index -= nilfs_btree_node_get_nchildren(node);
944 nilfs_btree_node_insert(right, path[level].bp_index,
945 *keyp, *ptrp, ncblk);
946
947 *keyp = nilfs_btree_node_get_key(right, 0);
948 *ptrp = path[level].bp_newreq.bpr_ptr;
949
950 brelse(path[level].bp_bh);
951 path[level].bp_bh = path[level].bp_sib_bh;
952 path[level].bp_sib_bh = NULL;
953 } else {
954 nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
955
956 *keyp = nilfs_btree_node_get_key(right, 0);
957 *ptrp = path[level].bp_newreq.bpr_ptr;
958
959 brelse(path[level].bp_sib_bh);
960 path[level].bp_sib_bh = NULL;
961 }
962
963 path[level + 1].bp_index++;
964 }
965
966 static void nilfs_btree_grow(struct nilfs_bmap *btree,
967 struct nilfs_btree_path *path,
968 int level, __u64 *keyp, __u64 *ptrp)
969 {
970 struct nilfs_btree_node *root, *child;
971 int n, ncblk;
972
973 root = nilfs_btree_get_root(btree);
974 child = nilfs_btree_get_sib_node(path, level);
975 ncblk = nilfs_btree_nchildren_per_block(btree);
976
977 n = nilfs_btree_node_get_nchildren(root);
978
979 nilfs_btree_node_move_right(root, child, n,
980 NILFS_BTREE_ROOT_NCHILDREN_MAX, ncblk);
981 nilfs_btree_node_set_level(root, level + 1);
982
983 if (!buffer_dirty(path[level].bp_sib_bh))
984 mark_buffer_dirty(path[level].bp_sib_bh);
985
986 path[level].bp_bh = path[level].bp_sib_bh;
987 path[level].bp_sib_bh = NULL;
988
989 nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
990
991 *keyp = nilfs_btree_node_get_key(child, 0);
992 *ptrp = path[level].bp_newreq.bpr_ptr;
993 }
994
995 static __u64 nilfs_btree_find_near(const struct nilfs_bmap *btree,
996 const struct nilfs_btree_path *path)
997 {
998 struct nilfs_btree_node *node;
999 int level, ncmax;
1000
1001 if (path == NULL)
1002 return NILFS_BMAP_INVALID_PTR;
1003
1004 /* left sibling */
1005 level = NILFS_BTREE_LEVEL_NODE_MIN;
1006 if (path[level].bp_index > 0) {
1007 node = nilfs_btree_get_node(btree, path, level, &ncmax);
1008 return nilfs_btree_node_get_ptr(node,
1009 path[level].bp_index - 1,
1010 ncmax);
1011 }
1012
1013 /* parent */
1014 level = NILFS_BTREE_LEVEL_NODE_MIN + 1;
1015 if (level <= nilfs_btree_height(btree) - 1) {
1016 node = nilfs_btree_get_node(btree, path, level, &ncmax);
1017 return nilfs_btree_node_get_ptr(node, path[level].bp_index,
1018 ncmax);
1019 }
1020
1021 return NILFS_BMAP_INVALID_PTR;
1022 }
1023
1024 static __u64 nilfs_btree_find_target_v(const struct nilfs_bmap *btree,
1025 const struct nilfs_btree_path *path,
1026 __u64 key)
1027 {
1028 __u64 ptr;
1029
1030 ptr = nilfs_bmap_find_target_seq(btree, key);
1031 if (ptr != NILFS_BMAP_INVALID_PTR)
1032 /* sequential access */
1033 return ptr;
1034
1035 ptr = nilfs_btree_find_near(btree, path);
1036 if (ptr != NILFS_BMAP_INVALID_PTR)
1037 /* near */
1038 return ptr;
1039
1040 /* block group */
1041 return nilfs_bmap_find_target_in_group(btree);
1042 }
1043
1044 static int nilfs_btree_prepare_insert(struct nilfs_bmap *btree,
1045 struct nilfs_btree_path *path,
1046 int *levelp, __u64 key, __u64 ptr,
1047 struct nilfs_bmap_stats *stats)
1048 {
1049 struct buffer_head *bh;
1050 struct nilfs_btree_node *node, *parent, *sib;
1051 __u64 sibptr;
1052 int pindex, level, ncmax, ncblk, ret;
1053 struct inode *dat = NULL;
1054
1055 stats->bs_nblocks = 0;
1056 level = NILFS_BTREE_LEVEL_DATA;
1057
1058 /* allocate a new ptr for data block */
1059 if (NILFS_BMAP_USE_VBN(btree)) {
1060 path[level].bp_newreq.bpr_ptr =
1061 nilfs_btree_find_target_v(btree, path, key);
1062 dat = nilfs_bmap_get_dat(btree);
1063 }
1064
1065 ret = nilfs_bmap_prepare_alloc_ptr(btree, &path[level].bp_newreq, dat);
1066 if (ret < 0)
1067 goto err_out_data;
1068
1069 ncblk = nilfs_btree_nchildren_per_block(btree);
1070
1071 for (level = NILFS_BTREE_LEVEL_NODE_MIN;
1072 level < nilfs_btree_height(btree) - 1;
1073 level++) {
1074 node = nilfs_btree_get_nonroot_node(path, level);
1075 if (nilfs_btree_node_get_nchildren(node) < ncblk) {
1076 path[level].bp_op = nilfs_btree_do_insert;
1077 stats->bs_nblocks++;
1078 goto out;
1079 }
1080
1081 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
1082 pindex = path[level + 1].bp_index;
1083
1084 /* left sibling */
1085 if (pindex > 0) {
1086 sibptr = nilfs_btree_node_get_ptr(parent, pindex - 1,
1087 ncmax);
1088 ret = nilfs_btree_get_block(btree, sibptr, &bh);
1089 if (ret < 0)
1090 goto err_out_child_node;
1091 sib = (struct nilfs_btree_node *)bh->b_data;
1092 if (nilfs_btree_node_get_nchildren(sib) < ncblk) {
1093 path[level].bp_sib_bh = bh;
1094 path[level].bp_op = nilfs_btree_carry_left;
1095 stats->bs_nblocks++;
1096 goto out;
1097 } else {
1098 brelse(bh);
1099 }
1100 }
1101
1102 /* right sibling */
1103 if (pindex < nilfs_btree_node_get_nchildren(parent) - 1) {
1104 sibptr = nilfs_btree_node_get_ptr(parent, pindex + 1,
1105 ncmax);
1106 ret = nilfs_btree_get_block(btree, sibptr, &bh);
1107 if (ret < 0)
1108 goto err_out_child_node;
1109 sib = (struct nilfs_btree_node *)bh->b_data;
1110 if (nilfs_btree_node_get_nchildren(sib) < ncblk) {
1111 path[level].bp_sib_bh = bh;
1112 path[level].bp_op = nilfs_btree_carry_right;
1113 stats->bs_nblocks++;
1114 goto out;
1115 } else {
1116 brelse(bh);
1117 }
1118 }
1119
1120 /* split */
1121 path[level].bp_newreq.bpr_ptr =
1122 path[level - 1].bp_newreq.bpr_ptr + 1;
1123 ret = nilfs_bmap_prepare_alloc_ptr(btree,
1124 &path[level].bp_newreq, dat);
1125 if (ret < 0)
1126 goto err_out_child_node;
1127 ret = nilfs_btree_get_new_block(btree,
1128 path[level].bp_newreq.bpr_ptr,
1129 &bh);
1130 if (ret < 0)
1131 goto err_out_curr_node;
1132
1133 stats->bs_nblocks++;
1134
1135 sib = (struct nilfs_btree_node *)bh->b_data;
1136 nilfs_btree_node_init(sib, 0, level, 0, ncblk, NULL, NULL);
1137 path[level].bp_sib_bh = bh;
1138 path[level].bp_op = nilfs_btree_split;
1139 }
1140
1141 /* root */
1142 node = nilfs_btree_get_root(btree);
1143 if (nilfs_btree_node_get_nchildren(node) <
1144 NILFS_BTREE_ROOT_NCHILDREN_MAX) {
1145 path[level].bp_op = nilfs_btree_do_insert;
1146 stats->bs_nblocks++;
1147 goto out;
1148 }
1149
1150 /* grow */
1151 path[level].bp_newreq.bpr_ptr = path[level - 1].bp_newreq.bpr_ptr + 1;
1152 ret = nilfs_bmap_prepare_alloc_ptr(btree, &path[level].bp_newreq, dat);
1153 if (ret < 0)
1154 goto err_out_child_node;
1155 ret = nilfs_btree_get_new_block(btree, path[level].bp_newreq.bpr_ptr,
1156 &bh);
1157 if (ret < 0)
1158 goto err_out_curr_node;
1159
1160 nilfs_btree_node_init((struct nilfs_btree_node *)bh->b_data,
1161 0, level, 0, ncblk, NULL, NULL);
1162 path[level].bp_sib_bh = bh;
1163 path[level].bp_op = nilfs_btree_grow;
1164
1165 level++;
1166 path[level].bp_op = nilfs_btree_do_insert;
1167
1168 /* a newly-created node block and a data block are added */
1169 stats->bs_nblocks += 2;
1170
1171 /* success */
1172 out:
1173 *levelp = level;
1174 return ret;
1175
1176 /* error */
1177 err_out_curr_node:
1178 nilfs_bmap_abort_alloc_ptr(btree, &path[level].bp_newreq, dat);
1179 err_out_child_node:
1180 for (level--; level > NILFS_BTREE_LEVEL_DATA; level--) {
1181 nilfs_btnode_delete(path[level].bp_sib_bh);
1182 nilfs_bmap_abort_alloc_ptr(btree, &path[level].bp_newreq, dat);
1183
1184 }
1185
1186 nilfs_bmap_abort_alloc_ptr(btree, &path[level].bp_newreq, dat);
1187 err_out_data:
1188 *levelp = level;
1189 stats->bs_nblocks = 0;
1190 return ret;
1191 }
1192
1193 static void nilfs_btree_commit_insert(struct nilfs_bmap *btree,
1194 struct nilfs_btree_path *path,
1195 int maxlevel, __u64 key, __u64 ptr)
1196 {
1197 struct inode *dat = NULL;
1198 int level;
1199
1200 set_buffer_nilfs_volatile((struct buffer_head *)((unsigned long)ptr));
1201 ptr = path[NILFS_BTREE_LEVEL_DATA].bp_newreq.bpr_ptr;
1202 if (NILFS_BMAP_USE_VBN(btree)) {
1203 nilfs_bmap_set_target_v(btree, key, ptr);
1204 dat = nilfs_bmap_get_dat(btree);
1205 }
1206
1207 for (level = NILFS_BTREE_LEVEL_NODE_MIN; level <= maxlevel; level++) {
1208 nilfs_bmap_commit_alloc_ptr(btree,
1209 &path[level - 1].bp_newreq, dat);
1210 path[level].bp_op(btree, path, level, &key, &ptr);
1211 }
1212
1213 if (!nilfs_bmap_dirty(btree))
1214 nilfs_bmap_set_dirty(btree);
1215 }
1216
1217 static int nilfs_btree_insert(struct nilfs_bmap *btree, __u64 key, __u64 ptr)
1218 {
1219 struct nilfs_btree_path *path;
1220 struct nilfs_bmap_stats stats;
1221 int level, ret;
1222
1223 path = nilfs_btree_alloc_path();
1224 if (path == NULL)
1225 return -ENOMEM;
1226
1227 ret = nilfs_btree_do_lookup(btree, path, key, NULL,
1228 NILFS_BTREE_LEVEL_NODE_MIN, 0);
1229 if (ret != -ENOENT) {
1230 if (ret == 0)
1231 ret = -EEXIST;
1232 goto out;
1233 }
1234
1235 ret = nilfs_btree_prepare_insert(btree, path, &level, key, ptr, &stats);
1236 if (ret < 0)
1237 goto out;
1238 nilfs_btree_commit_insert(btree, path, level, key, ptr);
1239 nilfs_inode_add_blocks(btree->b_inode, stats.bs_nblocks);
1240
1241 out:
1242 nilfs_btree_free_path(path);
1243 return ret;
1244 }
1245
1246 static void nilfs_btree_do_delete(struct nilfs_bmap *btree,
1247 struct nilfs_btree_path *path,
1248 int level, __u64 *keyp, __u64 *ptrp)
1249 {
1250 struct nilfs_btree_node *node;
1251 int ncblk;
1252
1253 if (level < nilfs_btree_height(btree) - 1) {
1254 node = nilfs_btree_get_nonroot_node(path, level);
1255 ncblk = nilfs_btree_nchildren_per_block(btree);
1256 nilfs_btree_node_delete(node, path[level].bp_index,
1257 keyp, ptrp, ncblk);
1258 if (!buffer_dirty(path[level].bp_bh))
1259 mark_buffer_dirty(path[level].bp_bh);
1260 if (path[level].bp_index == 0)
1261 nilfs_btree_promote_key(btree, path, level + 1,
1262 nilfs_btree_node_get_key(node, 0));
1263 } else {
1264 node = nilfs_btree_get_root(btree);
1265 nilfs_btree_node_delete(node, path[level].bp_index,
1266 keyp, ptrp,
1267 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1268 }
1269 }
1270
1271 static void nilfs_btree_borrow_left(struct nilfs_bmap *btree,
1272 struct nilfs_btree_path *path,
1273 int level, __u64 *keyp, __u64 *ptrp)
1274 {
1275 struct nilfs_btree_node *node, *left;
1276 int nchildren, lnchildren, n, ncblk;
1277
1278 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1279
1280 node = nilfs_btree_get_nonroot_node(path, level);
1281 left = nilfs_btree_get_sib_node(path, level);
1282 nchildren = nilfs_btree_node_get_nchildren(node);
1283 lnchildren = nilfs_btree_node_get_nchildren(left);
1284 ncblk = nilfs_btree_nchildren_per_block(btree);
1285
1286 n = (nchildren + lnchildren) / 2 - nchildren;
1287
1288 nilfs_btree_node_move_right(left, node, n, ncblk, ncblk);
1289
1290 if (!buffer_dirty(path[level].bp_bh))
1291 mark_buffer_dirty(path[level].bp_bh);
1292 if (!buffer_dirty(path[level].bp_sib_bh))
1293 mark_buffer_dirty(path[level].bp_sib_bh);
1294
1295 nilfs_btree_promote_key(btree, path, level + 1,
1296 nilfs_btree_node_get_key(node, 0));
1297
1298 brelse(path[level].bp_sib_bh);
1299 path[level].bp_sib_bh = NULL;
1300 path[level].bp_index += n;
1301 }
1302
1303 static void nilfs_btree_borrow_right(struct nilfs_bmap *btree,
1304 struct nilfs_btree_path *path,
1305 int level, __u64 *keyp, __u64 *ptrp)
1306 {
1307 struct nilfs_btree_node *node, *right;
1308 int nchildren, rnchildren, n, ncblk;
1309
1310 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1311
1312 node = nilfs_btree_get_nonroot_node(path, level);
1313 right = nilfs_btree_get_sib_node(path, level);
1314 nchildren = nilfs_btree_node_get_nchildren(node);
1315 rnchildren = nilfs_btree_node_get_nchildren(right);
1316 ncblk = nilfs_btree_nchildren_per_block(btree);
1317
1318 n = (nchildren + rnchildren) / 2 - nchildren;
1319
1320 nilfs_btree_node_move_left(node, right, n, ncblk, ncblk);
1321
1322 if (!buffer_dirty(path[level].bp_bh))
1323 mark_buffer_dirty(path[level].bp_bh);
1324 if (!buffer_dirty(path[level].bp_sib_bh))
1325 mark_buffer_dirty(path[level].bp_sib_bh);
1326
1327 path[level + 1].bp_index++;
1328 nilfs_btree_promote_key(btree, path, level + 1,
1329 nilfs_btree_node_get_key(right, 0));
1330 path[level + 1].bp_index--;
1331
1332 brelse(path[level].bp_sib_bh);
1333 path[level].bp_sib_bh = NULL;
1334 }
1335
1336 static void nilfs_btree_concat_left(struct nilfs_bmap *btree,
1337 struct nilfs_btree_path *path,
1338 int level, __u64 *keyp, __u64 *ptrp)
1339 {
1340 struct nilfs_btree_node *node, *left;
1341 int n, ncblk;
1342
1343 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1344
1345 node = nilfs_btree_get_nonroot_node(path, level);
1346 left = nilfs_btree_get_sib_node(path, level);
1347 ncblk = nilfs_btree_nchildren_per_block(btree);
1348
1349 n = nilfs_btree_node_get_nchildren(node);
1350
1351 nilfs_btree_node_move_left(left, node, n, ncblk, ncblk);
1352
1353 if (!buffer_dirty(path[level].bp_sib_bh))
1354 mark_buffer_dirty(path[level].bp_sib_bh);
1355
1356 nilfs_btnode_delete(path[level].bp_bh);
1357 path[level].bp_bh = path[level].bp_sib_bh;
1358 path[level].bp_sib_bh = NULL;
1359 path[level].bp_index += nilfs_btree_node_get_nchildren(left);
1360 }
1361
1362 static void nilfs_btree_concat_right(struct nilfs_bmap *btree,
1363 struct nilfs_btree_path *path,
1364 int level, __u64 *keyp, __u64 *ptrp)
1365 {
1366 struct nilfs_btree_node *node, *right;
1367 int n, ncblk;
1368
1369 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1370
1371 node = nilfs_btree_get_nonroot_node(path, level);
1372 right = nilfs_btree_get_sib_node(path, level);
1373 ncblk = nilfs_btree_nchildren_per_block(btree);
1374
1375 n = nilfs_btree_node_get_nchildren(right);
1376
1377 nilfs_btree_node_move_left(node, right, n, ncblk, ncblk);
1378
1379 if (!buffer_dirty(path[level].bp_bh))
1380 mark_buffer_dirty(path[level].bp_bh);
1381
1382 nilfs_btnode_delete(path[level].bp_sib_bh);
1383 path[level].bp_sib_bh = NULL;
1384 path[level + 1].bp_index++;
1385 }
1386
1387 static void nilfs_btree_shrink(struct nilfs_bmap *btree,
1388 struct nilfs_btree_path *path,
1389 int level, __u64 *keyp, __u64 *ptrp)
1390 {
1391 struct nilfs_btree_node *root, *child;
1392 int n, ncblk;
1393
1394 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1395
1396 root = nilfs_btree_get_root(btree);
1397 child = nilfs_btree_get_nonroot_node(path, level);
1398 ncblk = nilfs_btree_nchildren_per_block(btree);
1399
1400 nilfs_btree_node_delete(root, 0, NULL, NULL,
1401 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1402 nilfs_btree_node_set_level(root, level);
1403 n = nilfs_btree_node_get_nchildren(child);
1404 nilfs_btree_node_move_left(root, child, n,
1405 NILFS_BTREE_ROOT_NCHILDREN_MAX, ncblk);
1406
1407 nilfs_btnode_delete(path[level].bp_bh);
1408 path[level].bp_bh = NULL;
1409 }
1410
1411 static void nilfs_btree_nop(struct nilfs_bmap *btree,
1412 struct nilfs_btree_path *path,
1413 int level, __u64 *keyp, __u64 *ptrp)
1414 {
1415 }
1416
1417 static int nilfs_btree_prepare_delete(struct nilfs_bmap *btree,
1418 struct nilfs_btree_path *path,
1419 int *levelp,
1420 struct nilfs_bmap_stats *stats,
1421 struct inode *dat)
1422 {
1423 struct buffer_head *bh;
1424 struct nilfs_btree_node *node, *parent, *sib;
1425 __u64 sibptr;
1426 int pindex, dindex, level, ncmin, ncmax, ncblk, ret;
1427
1428 ret = 0;
1429 stats->bs_nblocks = 0;
1430 ncmin = NILFS_BTREE_NODE_NCHILDREN_MIN(nilfs_btree_node_size(btree));
1431 ncblk = nilfs_btree_nchildren_per_block(btree);
1432
1433 for (level = NILFS_BTREE_LEVEL_NODE_MIN, dindex = path[level].bp_index;
1434 level < nilfs_btree_height(btree) - 1;
1435 level++) {
1436 node = nilfs_btree_get_nonroot_node(path, level);
1437 path[level].bp_oldreq.bpr_ptr =
1438 nilfs_btree_node_get_ptr(node, dindex, ncblk);
1439 ret = nilfs_bmap_prepare_end_ptr(btree,
1440 &path[level].bp_oldreq, dat);
1441 if (ret < 0)
1442 goto err_out_child_node;
1443
1444 if (nilfs_btree_node_get_nchildren(node) > ncmin) {
1445 path[level].bp_op = nilfs_btree_do_delete;
1446 stats->bs_nblocks++;
1447 goto out;
1448 }
1449
1450 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
1451 pindex = path[level + 1].bp_index;
1452 dindex = pindex;
1453
1454 if (pindex > 0) {
1455 /* left sibling */
1456 sibptr = nilfs_btree_node_get_ptr(parent, pindex - 1,
1457 ncmax);
1458 ret = nilfs_btree_get_block(btree, sibptr, &bh);
1459 if (ret < 0)
1460 goto err_out_curr_node;
1461 sib = (struct nilfs_btree_node *)bh->b_data;
1462 if (nilfs_btree_node_get_nchildren(sib) > ncmin) {
1463 path[level].bp_sib_bh = bh;
1464 path[level].bp_op = nilfs_btree_borrow_left;
1465 stats->bs_nblocks++;
1466 goto out;
1467 } else {
1468 path[level].bp_sib_bh = bh;
1469 path[level].bp_op = nilfs_btree_concat_left;
1470 stats->bs_nblocks++;
1471 /* continue; */
1472 }
1473 } else if (pindex <
1474 nilfs_btree_node_get_nchildren(parent) - 1) {
1475 /* right sibling */
1476 sibptr = nilfs_btree_node_get_ptr(parent, pindex + 1,
1477 ncmax);
1478 ret = nilfs_btree_get_block(btree, sibptr, &bh);
1479 if (ret < 0)
1480 goto err_out_curr_node;
1481 sib = (struct nilfs_btree_node *)bh->b_data;
1482 if (nilfs_btree_node_get_nchildren(sib) > ncmin) {
1483 path[level].bp_sib_bh = bh;
1484 path[level].bp_op = nilfs_btree_borrow_right;
1485 stats->bs_nblocks++;
1486 goto out;
1487 } else {
1488 path[level].bp_sib_bh = bh;
1489 path[level].bp_op = nilfs_btree_concat_right;
1490 stats->bs_nblocks++;
1491 /*
1492 * When merging right sibling node
1493 * into the current node, pointer to
1494 * the right sibling node must be
1495 * terminated instead. The adjustment
1496 * below is required for that.
1497 */
1498 dindex = pindex + 1;
1499 /* continue; */
1500 }
1501 } else {
1502 /* no siblings */
1503 /* the only child of the root node */
1504 WARN_ON(level != nilfs_btree_height(btree) - 2);
1505 if (nilfs_btree_node_get_nchildren(node) - 1 <=
1506 NILFS_BTREE_ROOT_NCHILDREN_MAX) {
1507 path[level].bp_op = nilfs_btree_shrink;
1508 stats->bs_nblocks += 2;
1509 level++;
1510 path[level].bp_op = nilfs_btree_nop;
1511 goto shrink_root_child;
1512 } else {
1513 path[level].bp_op = nilfs_btree_do_delete;
1514 stats->bs_nblocks++;
1515 goto out;
1516 }
1517 }
1518 }
1519
1520 /* child of the root node is deleted */
1521 path[level].bp_op = nilfs_btree_do_delete;
1522 stats->bs_nblocks++;
1523
1524 shrink_root_child:
1525 node = nilfs_btree_get_root(btree);
1526 path[level].bp_oldreq.bpr_ptr =
1527 nilfs_btree_node_get_ptr(node, dindex,
1528 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1529
1530 ret = nilfs_bmap_prepare_end_ptr(btree, &path[level].bp_oldreq, dat);
1531 if (ret < 0)
1532 goto err_out_child_node;
1533
1534 /* success */
1535 out:
1536 *levelp = level;
1537 return ret;
1538
1539 /* error */
1540 err_out_curr_node:
1541 nilfs_bmap_abort_end_ptr(btree, &path[level].bp_oldreq, dat);
1542 err_out_child_node:
1543 for (level--; level >= NILFS_BTREE_LEVEL_NODE_MIN; level--) {
1544 brelse(path[level].bp_sib_bh);
1545 nilfs_bmap_abort_end_ptr(btree, &path[level].bp_oldreq, dat);
1546 }
1547 *levelp = level;
1548 stats->bs_nblocks = 0;
1549 return ret;
1550 }
1551
1552 static void nilfs_btree_commit_delete(struct nilfs_bmap *btree,
1553 struct nilfs_btree_path *path,
1554 int maxlevel, struct inode *dat)
1555 {
1556 int level;
1557
1558 for (level = NILFS_BTREE_LEVEL_NODE_MIN; level <= maxlevel; level++) {
1559 nilfs_bmap_commit_end_ptr(btree, &path[level].bp_oldreq, dat);
1560 path[level].bp_op(btree, path, level, NULL, NULL);
1561 }
1562
1563 if (!nilfs_bmap_dirty(btree))
1564 nilfs_bmap_set_dirty(btree);
1565 }
1566
1567 static int nilfs_btree_delete(struct nilfs_bmap *btree, __u64 key)
1568
1569 {
1570 struct nilfs_btree_path *path;
1571 struct nilfs_bmap_stats stats;
1572 struct inode *dat;
1573 int level, ret;
1574
1575 path = nilfs_btree_alloc_path();
1576 if (path == NULL)
1577 return -ENOMEM;
1578
1579 ret = nilfs_btree_do_lookup(btree, path, key, NULL,
1580 NILFS_BTREE_LEVEL_NODE_MIN, 0);
1581 if (ret < 0)
1582 goto out;
1583
1584
1585 dat = NILFS_BMAP_USE_VBN(btree) ? nilfs_bmap_get_dat(btree) : NULL;
1586
1587 ret = nilfs_btree_prepare_delete(btree, path, &level, &stats, dat);
1588 if (ret < 0)
1589 goto out;
1590 nilfs_btree_commit_delete(btree, path, level, dat);
1591 nilfs_inode_sub_blocks(btree->b_inode, stats.bs_nblocks);
1592
1593 out:
1594 nilfs_btree_free_path(path);
1595 return ret;
1596 }
1597
1598 static int nilfs_btree_seek_key(const struct nilfs_bmap *btree, __u64 start,
1599 __u64 *keyp)
1600 {
1601 struct nilfs_btree_path *path;
1602 const int minlevel = NILFS_BTREE_LEVEL_NODE_MIN;
1603 int ret;
1604
1605 path = nilfs_btree_alloc_path();
1606 if (!path)
1607 return -ENOMEM;
1608
1609 ret = nilfs_btree_do_lookup(btree, path, start, NULL, minlevel, 0);
1610 if (!ret)
1611 *keyp = start;
1612 else if (ret == -ENOENT)
1613 ret = nilfs_btree_get_next_key(btree, path, minlevel, keyp);
1614
1615 nilfs_btree_free_path(path);
1616 return ret;
1617 }
1618
1619 static int nilfs_btree_last_key(const struct nilfs_bmap *btree, __u64 *keyp)
1620 {
1621 struct nilfs_btree_path *path;
1622 int ret;
1623
1624 path = nilfs_btree_alloc_path();
1625 if (path == NULL)
1626 return -ENOMEM;
1627
1628 ret = nilfs_btree_do_lookup_last(btree, path, keyp, NULL);
1629
1630 nilfs_btree_free_path(path);
1631
1632 return ret;
1633 }
1634
1635 static int nilfs_btree_check_delete(struct nilfs_bmap *btree, __u64 key)
1636 {
1637 struct buffer_head *bh;
1638 struct nilfs_btree_node *root, *node;
1639 __u64 maxkey, nextmaxkey;
1640 __u64 ptr;
1641 int nchildren, ret;
1642
1643 root = nilfs_btree_get_root(btree);
1644 switch (nilfs_btree_height(btree)) {
1645 case 2:
1646 bh = NULL;
1647 node = root;
1648 break;
1649 case 3:
1650 nchildren = nilfs_btree_node_get_nchildren(root);
1651 if (nchildren > 1)
1652 return 0;
1653 ptr = nilfs_btree_node_get_ptr(root, nchildren - 1,
1654 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1655 ret = nilfs_btree_get_block(btree, ptr, &bh);
1656 if (ret < 0)
1657 return ret;
1658 node = (struct nilfs_btree_node *)bh->b_data;
1659 break;
1660 default:
1661 return 0;
1662 }
1663
1664 nchildren = nilfs_btree_node_get_nchildren(node);
1665 maxkey = nilfs_btree_node_get_key(node, nchildren - 1);
1666 nextmaxkey = (nchildren > 1) ?
1667 nilfs_btree_node_get_key(node, nchildren - 2) : 0;
1668 if (bh != NULL)
1669 brelse(bh);
1670
1671 return (maxkey == key) && (nextmaxkey < NILFS_BMAP_LARGE_LOW);
1672 }
1673
1674 static int nilfs_btree_gather_data(struct nilfs_bmap *btree,
1675 __u64 *keys, __u64 *ptrs, int nitems)
1676 {
1677 struct buffer_head *bh;
1678 struct nilfs_btree_node *node, *root;
1679 __le64 *dkeys;
1680 __le64 *dptrs;
1681 __u64 ptr;
1682 int nchildren, ncmax, i, ret;
1683
1684 root = nilfs_btree_get_root(btree);
1685 switch (nilfs_btree_height(btree)) {
1686 case 2:
1687 bh = NULL;
1688 node = root;
1689 ncmax = NILFS_BTREE_ROOT_NCHILDREN_MAX;
1690 break;
1691 case 3:
1692 nchildren = nilfs_btree_node_get_nchildren(root);
1693 WARN_ON(nchildren > 1);
1694 ptr = nilfs_btree_node_get_ptr(root, nchildren - 1,
1695 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1696 ret = nilfs_btree_get_block(btree, ptr, &bh);
1697 if (ret < 0)
1698 return ret;
1699 node = (struct nilfs_btree_node *)bh->b_data;
1700 ncmax = nilfs_btree_nchildren_per_block(btree);
1701 break;
1702 default:
1703 node = NULL;
1704 return -EINVAL;
1705 }
1706
1707 nchildren = nilfs_btree_node_get_nchildren(node);
1708 if (nchildren < nitems)
1709 nitems = nchildren;
1710 dkeys = nilfs_btree_node_dkeys(node);
1711 dptrs = nilfs_btree_node_dptrs(node, ncmax);
1712 for (i = 0; i < nitems; i++) {
1713 keys[i] = le64_to_cpu(dkeys[i]);
1714 ptrs[i] = le64_to_cpu(dptrs[i]);
1715 }
1716
1717 if (bh != NULL)
1718 brelse(bh);
1719
1720 return nitems;
1721 }
1722
1723 static int
1724 nilfs_btree_prepare_convert_and_insert(struct nilfs_bmap *btree, __u64 key,
1725 union nilfs_bmap_ptr_req *dreq,
1726 union nilfs_bmap_ptr_req *nreq,
1727 struct buffer_head **bhp,
1728 struct nilfs_bmap_stats *stats)
1729 {
1730 struct buffer_head *bh;
1731 struct inode *dat = NULL;
1732 int ret;
1733
1734 stats->bs_nblocks = 0;
1735
1736 /* for data */
1737 /* cannot find near ptr */
1738 if (NILFS_BMAP_USE_VBN(btree)) {
1739 dreq->bpr_ptr = nilfs_btree_find_target_v(btree, NULL, key);
1740 dat = nilfs_bmap_get_dat(btree);
1741 }
1742
1743 ret = nilfs_bmap_prepare_alloc_ptr(btree, dreq, dat);
1744 if (ret < 0)
1745 return ret;
1746
1747 *bhp = NULL;
1748 stats->bs_nblocks++;
1749 if (nreq != NULL) {
1750 nreq->bpr_ptr = dreq->bpr_ptr + 1;
1751 ret = nilfs_bmap_prepare_alloc_ptr(btree, nreq, dat);
1752 if (ret < 0)
1753 goto err_out_dreq;
1754
1755 ret = nilfs_btree_get_new_block(btree, nreq->bpr_ptr, &bh);
1756 if (ret < 0)
1757 goto err_out_nreq;
1758
1759 *bhp = bh;
1760 stats->bs_nblocks++;
1761 }
1762
1763 /* success */
1764 return 0;
1765
1766 /* error */
1767 err_out_nreq:
1768 nilfs_bmap_abort_alloc_ptr(btree, nreq, dat);
1769 err_out_dreq:
1770 nilfs_bmap_abort_alloc_ptr(btree, dreq, dat);
1771 stats->bs_nblocks = 0;
1772 return ret;
1773
1774 }
1775
1776 static void
1777 nilfs_btree_commit_convert_and_insert(struct nilfs_bmap *btree,
1778 __u64 key, __u64 ptr,
1779 const __u64 *keys, const __u64 *ptrs,
1780 int n,
1781 union nilfs_bmap_ptr_req *dreq,
1782 union nilfs_bmap_ptr_req *nreq,
1783 struct buffer_head *bh)
1784 {
1785 struct nilfs_btree_node *node;
1786 struct inode *dat;
1787 __u64 tmpptr;
1788 int ncblk;
1789
1790 /* free resources */
1791 if (btree->b_ops->bop_clear != NULL)
1792 btree->b_ops->bop_clear(btree);
1793
1794 /* ptr must be a pointer to a buffer head. */
1795 set_buffer_nilfs_volatile((struct buffer_head *)((unsigned long)ptr));
1796
1797 /* convert and insert */
1798 dat = NILFS_BMAP_USE_VBN(btree) ? nilfs_bmap_get_dat(btree) : NULL;
1799 __nilfs_btree_init(btree);
1800 if (nreq != NULL) {
1801 nilfs_bmap_commit_alloc_ptr(btree, dreq, dat);
1802 nilfs_bmap_commit_alloc_ptr(btree, nreq, dat);
1803
1804 /* create child node at level 1 */
1805 node = (struct nilfs_btree_node *)bh->b_data;
1806 ncblk = nilfs_btree_nchildren_per_block(btree);
1807 nilfs_btree_node_init(node, 0, 1, n, ncblk, keys, ptrs);
1808 nilfs_btree_node_insert(node, n, key, dreq->bpr_ptr, ncblk);
1809 if (!buffer_dirty(bh))
1810 mark_buffer_dirty(bh);
1811 if (!nilfs_bmap_dirty(btree))
1812 nilfs_bmap_set_dirty(btree);
1813
1814 brelse(bh);
1815
1816 /* create root node at level 2 */
1817 node = nilfs_btree_get_root(btree);
1818 tmpptr = nreq->bpr_ptr;
1819 nilfs_btree_node_init(node, NILFS_BTREE_NODE_ROOT, 2, 1,
1820 NILFS_BTREE_ROOT_NCHILDREN_MAX,
1821 &keys[0], &tmpptr);
1822 } else {
1823 nilfs_bmap_commit_alloc_ptr(btree, dreq, dat);
1824
1825 /* create root node at level 1 */
1826 node = nilfs_btree_get_root(btree);
1827 nilfs_btree_node_init(node, NILFS_BTREE_NODE_ROOT, 1, n,
1828 NILFS_BTREE_ROOT_NCHILDREN_MAX,
1829 keys, ptrs);
1830 nilfs_btree_node_insert(node, n, key, dreq->bpr_ptr,
1831 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1832 if (!nilfs_bmap_dirty(btree))
1833 nilfs_bmap_set_dirty(btree);
1834 }
1835
1836 if (NILFS_BMAP_USE_VBN(btree))
1837 nilfs_bmap_set_target_v(btree, key, dreq->bpr_ptr);
1838 }
1839
1840 /**
1841 * nilfs_btree_convert_and_insert -
1842 * @bmap:
1843 * @key:
1844 * @ptr:
1845 * @keys:
1846 * @ptrs:
1847 * @n:
1848 */
1849 int nilfs_btree_convert_and_insert(struct nilfs_bmap *btree,
1850 __u64 key, __u64 ptr,
1851 const __u64 *keys, const __u64 *ptrs, int n)
1852 {
1853 struct buffer_head *bh = NULL;
1854 union nilfs_bmap_ptr_req dreq, nreq, *di, *ni;
1855 struct nilfs_bmap_stats stats;
1856 int ret;
1857
1858 if (n + 1 <= NILFS_BTREE_ROOT_NCHILDREN_MAX) {
1859 di = &dreq;
1860 ni = NULL;
1861 } else if ((n + 1) <= NILFS_BTREE_NODE_NCHILDREN_MAX(
1862 1 << btree->b_inode->i_blkbits)) {
1863 di = &dreq;
1864 ni = &nreq;
1865 } else {
1866 di = NULL;
1867 ni = NULL;
1868 BUG();
1869 }
1870
1871 ret = nilfs_btree_prepare_convert_and_insert(btree, key, di, ni, &bh,
1872 &stats);
1873 if (ret < 0)
1874 return ret;
1875 nilfs_btree_commit_convert_and_insert(btree, key, ptr, keys, ptrs, n,
1876 di, ni, bh);
1877 nilfs_inode_add_blocks(btree->b_inode, stats.bs_nblocks);
1878 return 0;
1879 }
1880
1881 static int nilfs_btree_propagate_p(struct nilfs_bmap *btree,
1882 struct nilfs_btree_path *path,
1883 int level,
1884 struct buffer_head *bh)
1885 {
1886 while ((++level < nilfs_btree_height(btree) - 1) &&
1887 !buffer_dirty(path[level].bp_bh))
1888 mark_buffer_dirty(path[level].bp_bh);
1889
1890 return 0;
1891 }
1892
1893 static int nilfs_btree_prepare_update_v(struct nilfs_bmap *btree,
1894 struct nilfs_btree_path *path,
1895 int level, struct inode *dat)
1896 {
1897 struct nilfs_btree_node *parent;
1898 int ncmax, ret;
1899
1900 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
1901 path[level].bp_oldreq.bpr_ptr =
1902 nilfs_btree_node_get_ptr(parent, path[level + 1].bp_index,
1903 ncmax);
1904 path[level].bp_newreq.bpr_ptr = path[level].bp_oldreq.bpr_ptr + 1;
1905 ret = nilfs_dat_prepare_update(dat, &path[level].bp_oldreq.bpr_req,
1906 &path[level].bp_newreq.bpr_req);
1907 if (ret < 0)
1908 return ret;
1909
1910 if (buffer_nilfs_node(path[level].bp_bh)) {
1911 path[level].bp_ctxt.oldkey = path[level].bp_oldreq.bpr_ptr;
1912 path[level].bp_ctxt.newkey = path[level].bp_newreq.bpr_ptr;
1913 path[level].bp_ctxt.bh = path[level].bp_bh;
1914 ret = nilfs_btnode_prepare_change_key(
1915 &NILFS_BMAP_I(btree)->i_btnode_cache,
1916 &path[level].bp_ctxt);
1917 if (ret < 0) {
1918 nilfs_dat_abort_update(dat,
1919 &path[level].bp_oldreq.bpr_req,
1920 &path[level].bp_newreq.bpr_req);
1921 return ret;
1922 }
1923 }
1924
1925 return 0;
1926 }
1927
1928 static void nilfs_btree_commit_update_v(struct nilfs_bmap *btree,
1929 struct nilfs_btree_path *path,
1930 int level, struct inode *dat)
1931 {
1932 struct nilfs_btree_node *parent;
1933 int ncmax;
1934
1935 nilfs_dat_commit_update(dat, &path[level].bp_oldreq.bpr_req,
1936 &path[level].bp_newreq.bpr_req,
1937 btree->b_ptr_type == NILFS_BMAP_PTR_VS);
1938
1939 if (buffer_nilfs_node(path[level].bp_bh)) {
1940 nilfs_btnode_commit_change_key(
1941 &NILFS_BMAP_I(btree)->i_btnode_cache,
1942 &path[level].bp_ctxt);
1943 path[level].bp_bh = path[level].bp_ctxt.bh;
1944 }
1945 set_buffer_nilfs_volatile(path[level].bp_bh);
1946
1947 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
1948 nilfs_btree_node_set_ptr(parent, path[level + 1].bp_index,
1949 path[level].bp_newreq.bpr_ptr, ncmax);
1950 }
1951
1952 static void nilfs_btree_abort_update_v(struct nilfs_bmap *btree,
1953 struct nilfs_btree_path *path,
1954 int level, struct inode *dat)
1955 {
1956 nilfs_dat_abort_update(dat, &path[level].bp_oldreq.bpr_req,
1957 &path[level].bp_newreq.bpr_req);
1958 if (buffer_nilfs_node(path[level].bp_bh))
1959 nilfs_btnode_abort_change_key(
1960 &NILFS_BMAP_I(btree)->i_btnode_cache,
1961 &path[level].bp_ctxt);
1962 }
1963
1964 static int nilfs_btree_prepare_propagate_v(struct nilfs_bmap *btree,
1965 struct nilfs_btree_path *path,
1966 int minlevel, int *maxlevelp,
1967 struct inode *dat)
1968 {
1969 int level, ret;
1970
1971 level = minlevel;
1972 if (!buffer_nilfs_volatile(path[level].bp_bh)) {
1973 ret = nilfs_btree_prepare_update_v(btree, path, level, dat);
1974 if (ret < 0)
1975 return ret;
1976 }
1977 while ((++level < nilfs_btree_height(btree) - 1) &&
1978 !buffer_dirty(path[level].bp_bh)) {
1979
1980 WARN_ON(buffer_nilfs_volatile(path[level].bp_bh));
1981 ret = nilfs_btree_prepare_update_v(btree, path, level, dat);
1982 if (ret < 0)
1983 goto out;
1984 }
1985
1986 /* success */
1987 *maxlevelp = level - 1;
1988 return 0;
1989
1990 /* error */
1991 out:
1992 while (--level > minlevel)
1993 nilfs_btree_abort_update_v(btree, path, level, dat);
1994 if (!buffer_nilfs_volatile(path[level].bp_bh))
1995 nilfs_btree_abort_update_v(btree, path, level, dat);
1996 return ret;
1997 }
1998
1999 static void nilfs_btree_commit_propagate_v(struct nilfs_bmap *btree,
2000 struct nilfs_btree_path *path,
2001 int minlevel, int maxlevel,
2002 struct buffer_head *bh,
2003 struct inode *dat)
2004 {
2005 int level;
2006
2007 if (!buffer_nilfs_volatile(path[minlevel].bp_bh))
2008 nilfs_btree_commit_update_v(btree, path, minlevel, dat);
2009
2010 for (level = minlevel + 1; level <= maxlevel; level++)
2011 nilfs_btree_commit_update_v(btree, path, level, dat);
2012 }
2013
2014 static int nilfs_btree_propagate_v(struct nilfs_bmap *btree,
2015 struct nilfs_btree_path *path,
2016 int level, struct buffer_head *bh)
2017 {
2018 int maxlevel = 0, ret;
2019 struct nilfs_btree_node *parent;
2020 struct inode *dat = nilfs_bmap_get_dat(btree);
2021 __u64 ptr;
2022 int ncmax;
2023
2024 get_bh(bh);
2025 path[level].bp_bh = bh;
2026 ret = nilfs_btree_prepare_propagate_v(btree, path, level, &maxlevel,
2027 dat);
2028 if (ret < 0)
2029 goto out;
2030
2031 if (buffer_nilfs_volatile(path[level].bp_bh)) {
2032 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
2033 ptr = nilfs_btree_node_get_ptr(parent,
2034 path[level + 1].bp_index,
2035 ncmax);
2036 ret = nilfs_dat_mark_dirty(dat, ptr);
2037 if (ret < 0)
2038 goto out;
2039 }
2040
2041 nilfs_btree_commit_propagate_v(btree, path, level, maxlevel, bh, dat);
2042
2043 out:
2044 brelse(path[level].bp_bh);
2045 path[level].bp_bh = NULL;
2046 return ret;
2047 }
2048
2049 static int nilfs_btree_propagate(struct nilfs_bmap *btree,
2050 struct buffer_head *bh)
2051 {
2052 struct nilfs_btree_path *path;
2053 struct nilfs_btree_node *node;
2054 __u64 key;
2055 int level, ret;
2056
2057 WARN_ON(!buffer_dirty(bh));
2058
2059 path = nilfs_btree_alloc_path();
2060 if (path == NULL)
2061 return -ENOMEM;
2062
2063 if (buffer_nilfs_node(bh)) {
2064 node = (struct nilfs_btree_node *)bh->b_data;
2065 key = nilfs_btree_node_get_key(node, 0);
2066 level = nilfs_btree_node_get_level(node);
2067 } else {
2068 key = nilfs_bmap_data_get_key(btree, bh);
2069 level = NILFS_BTREE_LEVEL_DATA;
2070 }
2071
2072 ret = nilfs_btree_do_lookup(btree, path, key, NULL, level + 1, 0);
2073 if (ret < 0) {
2074 if (unlikely(ret == -ENOENT))
2075 printk(KERN_CRIT "%s: key = %llu, level == %d\n",
2076 __func__, (unsigned long long)key, level);
2077 goto out;
2078 }
2079
2080 ret = NILFS_BMAP_USE_VBN(btree) ?
2081 nilfs_btree_propagate_v(btree, path, level, bh) :
2082 nilfs_btree_propagate_p(btree, path, level, bh);
2083
2084 out:
2085 nilfs_btree_free_path(path);
2086
2087 return ret;
2088 }
2089
2090 static int nilfs_btree_propagate_gc(struct nilfs_bmap *btree,
2091 struct buffer_head *bh)
2092 {
2093 return nilfs_dat_mark_dirty(nilfs_bmap_get_dat(btree), bh->b_blocknr);
2094 }
2095
2096 static void nilfs_btree_add_dirty_buffer(struct nilfs_bmap *btree,
2097 struct list_head *lists,
2098 struct buffer_head *bh)
2099 {
2100 struct list_head *head;
2101 struct buffer_head *cbh;
2102 struct nilfs_btree_node *node, *cnode;
2103 __u64 key, ckey;
2104 int level;
2105
2106 get_bh(bh);
2107 node = (struct nilfs_btree_node *)bh->b_data;
2108 key = nilfs_btree_node_get_key(node, 0);
2109 level = nilfs_btree_node_get_level(node);
2110 if (level < NILFS_BTREE_LEVEL_NODE_MIN ||
2111 level >= NILFS_BTREE_LEVEL_MAX) {
2112 dump_stack();
2113 printk(KERN_WARNING
2114 "%s: invalid btree level: %d (key=%llu, ino=%lu, "
2115 "blocknr=%llu)\n",
2116 __func__, level, (unsigned long long)key,
2117 NILFS_BMAP_I(btree)->vfs_inode.i_ino,
2118 (unsigned long long)bh->b_blocknr);
2119 return;
2120 }
2121
2122 list_for_each(head, &lists[level]) {
2123 cbh = list_entry(head, struct buffer_head, b_assoc_buffers);
2124 cnode = (struct nilfs_btree_node *)cbh->b_data;
2125 ckey = nilfs_btree_node_get_key(cnode, 0);
2126 if (key < ckey)
2127 break;
2128 }
2129 list_add_tail(&bh->b_assoc_buffers, head);
2130 }
2131
2132 static void nilfs_btree_lookup_dirty_buffers(struct nilfs_bmap *btree,
2133 struct list_head *listp)
2134 {
2135 struct address_space *btcache = &NILFS_BMAP_I(btree)->i_btnode_cache;
2136 struct list_head lists[NILFS_BTREE_LEVEL_MAX];
2137 struct pagevec pvec;
2138 struct buffer_head *bh, *head;
2139 pgoff_t index = 0;
2140 int level, i;
2141
2142 for (level = NILFS_BTREE_LEVEL_NODE_MIN;
2143 level < NILFS_BTREE_LEVEL_MAX;
2144 level++)
2145 INIT_LIST_HEAD(&lists[level]);
2146
2147 pagevec_init(&pvec, 0);
2148
2149 while (pagevec_lookup_tag(&pvec, btcache, &index, PAGECACHE_TAG_DIRTY,
2150 PAGEVEC_SIZE)) {
2151 for (i = 0; i < pagevec_count(&pvec); i++) {
2152 bh = head = page_buffers(pvec.pages[i]);
2153 do {
2154 if (buffer_dirty(bh))
2155 nilfs_btree_add_dirty_buffer(btree,
2156 lists, bh);
2157 } while ((bh = bh->b_this_page) != head);
2158 }
2159 pagevec_release(&pvec);
2160 cond_resched();
2161 }
2162
2163 for (level = NILFS_BTREE_LEVEL_NODE_MIN;
2164 level < NILFS_BTREE_LEVEL_MAX;
2165 level++)
2166 list_splice_tail(&lists[level], listp);
2167 }
2168
2169 static int nilfs_btree_assign_p(struct nilfs_bmap *btree,
2170 struct nilfs_btree_path *path,
2171 int level,
2172 struct buffer_head **bh,
2173 sector_t blocknr,
2174 union nilfs_binfo *binfo)
2175 {
2176 struct nilfs_btree_node *parent;
2177 __u64 key;
2178 __u64 ptr;
2179 int ncmax, ret;
2180
2181 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
2182 ptr = nilfs_btree_node_get_ptr(parent, path[level + 1].bp_index,
2183 ncmax);
2184 if (buffer_nilfs_node(*bh)) {
2185 path[level].bp_ctxt.oldkey = ptr;
2186 path[level].bp_ctxt.newkey = blocknr;
2187 path[level].bp_ctxt.bh = *bh;
2188 ret = nilfs_btnode_prepare_change_key(
2189 &NILFS_BMAP_I(btree)->i_btnode_cache,
2190 &path[level].bp_ctxt);
2191 if (ret < 0)
2192 return ret;
2193 nilfs_btnode_commit_change_key(
2194 &NILFS_BMAP_I(btree)->i_btnode_cache,
2195 &path[level].bp_ctxt);
2196 *bh = path[level].bp_ctxt.bh;
2197 }
2198
2199 nilfs_btree_node_set_ptr(parent, path[level + 1].bp_index, blocknr,
2200 ncmax);
2201
2202 key = nilfs_btree_node_get_key(parent, path[level + 1].bp_index);
2203 /* on-disk format */
2204 binfo->bi_dat.bi_blkoff = cpu_to_le64(key);
2205 binfo->bi_dat.bi_level = level;
2206
2207 return 0;
2208 }
2209
2210 static int nilfs_btree_assign_v(struct nilfs_bmap *btree,
2211 struct nilfs_btree_path *path,
2212 int level,
2213 struct buffer_head **bh,
2214 sector_t blocknr,
2215 union nilfs_binfo *binfo)
2216 {
2217 struct nilfs_btree_node *parent;
2218 struct inode *dat = nilfs_bmap_get_dat(btree);
2219 __u64 key;
2220 __u64 ptr;
2221 union nilfs_bmap_ptr_req req;
2222 int ncmax, ret;
2223
2224 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
2225 ptr = nilfs_btree_node_get_ptr(parent, path[level + 1].bp_index,
2226 ncmax);
2227 req.bpr_ptr = ptr;
2228 ret = nilfs_dat_prepare_start(dat, &req.bpr_req);
2229 if (ret < 0)
2230 return ret;
2231 nilfs_dat_commit_start(dat, &req.bpr_req, blocknr);
2232
2233 key = nilfs_btree_node_get_key(parent, path[level + 1].bp_index);
2234 /* on-disk format */
2235 binfo->bi_v.bi_vblocknr = cpu_to_le64(ptr);
2236 binfo->bi_v.bi_blkoff = cpu_to_le64(key);
2237
2238 return 0;
2239 }
2240
2241 static int nilfs_btree_assign(struct nilfs_bmap *btree,
2242 struct buffer_head **bh,
2243 sector_t blocknr,
2244 union nilfs_binfo *binfo)
2245 {
2246 struct nilfs_btree_path *path;
2247 struct nilfs_btree_node *node;
2248 __u64 key;
2249 int level, ret;
2250
2251 path = nilfs_btree_alloc_path();
2252 if (path == NULL)
2253 return -ENOMEM;
2254
2255 if (buffer_nilfs_node(*bh)) {
2256 node = (struct nilfs_btree_node *)(*bh)->b_data;
2257 key = nilfs_btree_node_get_key(node, 0);
2258 level = nilfs_btree_node_get_level(node);
2259 } else {
2260 key = nilfs_bmap_data_get_key(btree, *bh);
2261 level = NILFS_BTREE_LEVEL_DATA;
2262 }
2263
2264 ret = nilfs_btree_do_lookup(btree, path, key, NULL, level + 1, 0);
2265 if (ret < 0) {
2266 WARN_ON(ret == -ENOENT);
2267 goto out;
2268 }
2269
2270 ret = NILFS_BMAP_USE_VBN(btree) ?
2271 nilfs_btree_assign_v(btree, path, level, bh, blocknr, binfo) :
2272 nilfs_btree_assign_p(btree, path, level, bh, blocknr, binfo);
2273
2274 out:
2275 nilfs_btree_free_path(path);
2276
2277 return ret;
2278 }
2279
2280 static int nilfs_btree_assign_gc(struct nilfs_bmap *btree,
2281 struct buffer_head **bh,
2282 sector_t blocknr,
2283 union nilfs_binfo *binfo)
2284 {
2285 struct nilfs_btree_node *node;
2286 __u64 key;
2287 int ret;
2288
2289 ret = nilfs_dat_move(nilfs_bmap_get_dat(btree), (*bh)->b_blocknr,
2290 blocknr);
2291 if (ret < 0)
2292 return ret;
2293
2294 if (buffer_nilfs_node(*bh)) {
2295 node = (struct nilfs_btree_node *)(*bh)->b_data;
2296 key = nilfs_btree_node_get_key(node, 0);
2297 } else
2298 key = nilfs_bmap_data_get_key(btree, *bh);
2299
2300 /* on-disk format */
2301 binfo->bi_v.bi_vblocknr = cpu_to_le64((*bh)->b_blocknr);
2302 binfo->bi_v.bi_blkoff = cpu_to_le64(key);
2303
2304 return 0;
2305 }
2306
2307 static int nilfs_btree_mark(struct nilfs_bmap *btree, __u64 key, int level)
2308 {
2309 struct buffer_head *bh;
2310 struct nilfs_btree_path *path;
2311 __u64 ptr;
2312 int ret;
2313
2314 path = nilfs_btree_alloc_path();
2315 if (path == NULL)
2316 return -ENOMEM;
2317
2318 ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level + 1, 0);
2319 if (ret < 0) {
2320 WARN_ON(ret == -ENOENT);
2321 goto out;
2322 }
2323 ret = nilfs_btree_get_block(btree, ptr, &bh);
2324 if (ret < 0) {
2325 WARN_ON(ret == -ENOENT);
2326 goto out;
2327 }
2328
2329 if (!buffer_dirty(bh))
2330 mark_buffer_dirty(bh);
2331 brelse(bh);
2332 if (!nilfs_bmap_dirty(btree))
2333 nilfs_bmap_set_dirty(btree);
2334
2335 out:
2336 nilfs_btree_free_path(path);
2337 return ret;
2338 }
2339
2340 static const struct nilfs_bmap_operations nilfs_btree_ops = {
2341 .bop_lookup = nilfs_btree_lookup,
2342 .bop_lookup_contig = nilfs_btree_lookup_contig,
2343 .bop_insert = nilfs_btree_insert,
2344 .bop_delete = nilfs_btree_delete,
2345 .bop_clear = NULL,
2346
2347 .bop_propagate = nilfs_btree_propagate,
2348
2349 .bop_lookup_dirty_buffers = nilfs_btree_lookup_dirty_buffers,
2350
2351 .bop_assign = nilfs_btree_assign,
2352 .bop_mark = nilfs_btree_mark,
2353
2354 .bop_seek_key = nilfs_btree_seek_key,
2355 .bop_last_key = nilfs_btree_last_key,
2356
2357 .bop_check_insert = NULL,
2358 .bop_check_delete = nilfs_btree_check_delete,
2359 .bop_gather_data = nilfs_btree_gather_data,
2360 };
2361
2362 static const struct nilfs_bmap_operations nilfs_btree_ops_gc = {
2363 .bop_lookup = NULL,
2364 .bop_lookup_contig = NULL,
2365 .bop_insert = NULL,
2366 .bop_delete = NULL,
2367 .bop_clear = NULL,
2368
2369 .bop_propagate = nilfs_btree_propagate_gc,
2370
2371 .bop_lookup_dirty_buffers = nilfs_btree_lookup_dirty_buffers,
2372
2373 .bop_assign = nilfs_btree_assign_gc,
2374 .bop_mark = NULL,
2375
2376 .bop_seek_key = NULL,
2377 .bop_last_key = NULL,
2378
2379 .bop_check_insert = NULL,
2380 .bop_check_delete = NULL,
2381 .bop_gather_data = NULL,
2382 };
2383
2384 static void __nilfs_btree_init(struct nilfs_bmap *bmap)
2385 {
2386 bmap->b_ops = &nilfs_btree_ops;
2387 bmap->b_nchildren_per_block =
2388 NILFS_BTREE_NODE_NCHILDREN_MAX(nilfs_btree_node_size(bmap));
2389 }
2390
2391 int nilfs_btree_init(struct nilfs_bmap *bmap)
2392 {
2393 int ret = 0;
2394
2395 __nilfs_btree_init(bmap);
2396
2397 if (nilfs_btree_root_broken(nilfs_btree_get_root(bmap),
2398 bmap->b_inode->i_ino))
2399 ret = -EIO;
2400 return ret;
2401 }
2402
2403 void nilfs_btree_init_gc(struct nilfs_bmap *bmap)
2404 {
2405 bmap->b_ops = &nilfs_btree_ops_gc;
2406 bmap->b_nchildren_per_block =
2407 NILFS_BTREE_NODE_NCHILDREN_MAX(nilfs_btree_node_size(bmap));
2408 }
Linux kernel - Deliverables
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