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AFS: Documentation updates
[linux-2.6/mini2440.git] / fs / nilfs2 / btree.c
blobaa412724b64eb41ab297c029b166ea3849de4710
1 /*
2 * btree.c - NILFS B-tree.
3 *
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 *
20 * Written by Koji Sato <koji@osrg.net>.
21 */
22
23 #include <linux/slab.h>
24 #include <linux/string.h>
25 #include <linux/errno.h>
26 #include <linux/pagevec.h>
27 #include "nilfs.h"
28 #include "page.h"
29 #include "btnode.h"
30 #include "btree.h"
31 #include "alloc.h"
32 #include "dat.h"
33
34 /**
35 * struct nilfs_btree_path - A path on which B-tree operations are executed
36 * @bp_bh: buffer head of node block
37 * @bp_sib_bh: buffer head of sibling node block
38 * @bp_index: index of child node
39 * @bp_oldreq: ptr end request for old ptr
40 * @bp_newreq: ptr alloc request for new ptr
41 * @bp_op: rebalance operation
42 */
43 struct nilfs_btree_path {
44 struct buffer_head *bp_bh;
45 struct buffer_head *bp_sib_bh;
46 int bp_index;
47 union nilfs_bmap_ptr_req bp_oldreq;
48 union nilfs_bmap_ptr_req bp_newreq;
49 struct nilfs_btnode_chkey_ctxt bp_ctxt;
50 void (*bp_op)(struct nilfs_btree *, struct nilfs_btree_path *,
51 int, __u64 *, __u64 *);
52 };
53
54 /*
55 * B-tree path operations
56 */
57
58 static struct kmem_cache *nilfs_btree_path_cache;
59
60 int __init nilfs_btree_path_cache_init(void)
61 {
62 nilfs_btree_path_cache =
63 kmem_cache_create("nilfs2_btree_path_cache",
64 sizeof(struct nilfs_btree_path) *
65 NILFS_BTREE_LEVEL_MAX, 0, 0, NULL);
66 return (nilfs_btree_path_cache != NULL) ? 0 : -ENOMEM;
67 }
68
69 void nilfs_btree_path_cache_destroy(void)
70 {
71 kmem_cache_destroy(nilfs_btree_path_cache);
72 }
73
74 static inline struct nilfs_btree_path *
75 nilfs_btree_alloc_path(const struct nilfs_btree *btree)
76 {
77 return (struct nilfs_btree_path *)
78 kmem_cache_alloc(nilfs_btree_path_cache, GFP_NOFS);
79 }
80
81 static inline void nilfs_btree_free_path(const struct nilfs_btree *btree,
82 struct nilfs_btree_path *path)
83 {
84 kmem_cache_free(nilfs_btree_path_cache, path);
85 }
86
87 static void nilfs_btree_init_path(const struct nilfs_btree *btree,
88 struct nilfs_btree_path *path)
89 {
90 int level;
91
92 for (level = NILFS_BTREE_LEVEL_DATA;
93 level < NILFS_BTREE_LEVEL_MAX;
94 level++) {
95 path[level].bp_bh = NULL;
96 path[level].bp_sib_bh = NULL;
97 path[level].bp_index = 0;
98 path[level].bp_oldreq.bpr_ptr = NILFS_BMAP_INVALID_PTR;
99 path[level].bp_newreq.bpr_ptr = NILFS_BMAP_INVALID_PTR;
100 path[level].bp_op = NULL;
101 }
102 }
103
104 static void nilfs_btree_clear_path(const struct nilfs_btree *btree,
105 struct nilfs_btree_path *path)
106 {
107 int level;
108
109 for (level = NILFS_BTREE_LEVEL_DATA;
110 level < NILFS_BTREE_LEVEL_MAX;
111 level++) {
112 if (path[level].bp_bh != NULL) {
113 brelse(path[level].bp_bh);
114 path[level].bp_bh = NULL;
115 }
116 /* sib_bh is released or deleted by prepare or commit
117 * operations. */
118 path[level].bp_sib_bh = NULL;
119 path[level].bp_index = 0;
120 path[level].bp_oldreq.bpr_ptr = NILFS_BMAP_INVALID_PTR;
121 path[level].bp_newreq.bpr_ptr = NILFS_BMAP_INVALID_PTR;
122 path[level].bp_op = NULL;
123 }
124 }
125
126 /*
127 * B-tree node operations
128 */
129 static int nilfs_btree_get_block(const struct nilfs_btree *btree, __u64 ptr,
130 struct buffer_head **bhp)
131 {
132 struct address_space *btnc =
133 &NILFS_BMAP_I((struct nilfs_bmap *)btree)->i_btnode_cache;
134 return nilfs_btnode_get(btnc, ptr, 0, bhp, 0);
135 }
136
137 static int nilfs_btree_get_new_block(const struct nilfs_btree *btree,
138 __u64 ptr, struct buffer_head **bhp)
139 {
140 struct address_space *btnc =
141 &NILFS_BMAP_I((struct nilfs_bmap *)btree)->i_btnode_cache;
142 int ret;
143
144 ret = nilfs_btnode_get(btnc, ptr, 0, bhp, 1);
145 if (!ret)
146 set_buffer_nilfs_volatile(*bhp);
147 return ret;
148 }
149
150 static inline int
151 nilfs_btree_node_get_flags(const struct nilfs_btree *btree,
152 const struct nilfs_btree_node *node)
153 {
154 return node->bn_flags;
155 }
156
157 static inline void
158 nilfs_btree_node_set_flags(struct nilfs_btree *btree,
159 struct nilfs_btree_node *node,
160 int flags)
161 {
162 node->bn_flags = flags;
163 }
164
165 static inline int nilfs_btree_node_root(const struct nilfs_btree *btree,
166 const struct nilfs_btree_node *node)
167 {
168 return nilfs_btree_node_get_flags(btree, node) & NILFS_BTREE_NODE_ROOT;
169 }
170
171 static inline int
172 nilfs_btree_node_get_level(const struct nilfs_btree *btree,
173 const struct nilfs_btree_node *node)
174 {
175 return node->bn_level;
176 }
177
178 static inline void
179 nilfs_btree_node_set_level(struct nilfs_btree *btree,
180 struct nilfs_btree_node *node,
181 int level)
182 {
183 node->bn_level = level;
184 }
185
186 static inline int
187 nilfs_btree_node_get_nchildren(const struct nilfs_btree *btree,
188 const struct nilfs_btree_node *node)
189 {
190 return le16_to_cpu(node->bn_nchildren);
191 }
192
193 static inline void
194 nilfs_btree_node_set_nchildren(struct nilfs_btree *btree,
195 struct nilfs_btree_node *node,
196 int nchildren)
197 {
198 node->bn_nchildren = cpu_to_le16(nchildren);
199 }
200
201 static inline int
202 nilfs_btree_node_size(const struct nilfs_btree *btree)
203 {
204 return 1 << btree->bt_bmap.b_inode->i_blkbits;
205 }
206
207 static inline int
208 nilfs_btree_node_nchildren_min(const struct nilfs_btree *btree,
209 const struct nilfs_btree_node *node)
210 {
211 return nilfs_btree_node_root(btree, node) ?
212 NILFS_BTREE_ROOT_NCHILDREN_MIN :
213 NILFS_BTREE_NODE_NCHILDREN_MIN(nilfs_btree_node_size(btree));
214 }
215
216 static inline int
217 nilfs_btree_node_nchildren_max(const struct nilfs_btree *btree,
218 const struct nilfs_btree_node *node)
219 {
220 return nilfs_btree_node_root(btree, node) ?
221 NILFS_BTREE_ROOT_NCHILDREN_MAX :
222 NILFS_BTREE_NODE_NCHILDREN_MAX(nilfs_btree_node_size(btree));
223 }
224
225 static inline __le64 *
226 nilfs_btree_node_dkeys(const struct nilfs_btree *btree,
227 const struct nilfs_btree_node *node)
228 {
229 return (__le64 *)((char *)(node + 1) +
230 (nilfs_btree_node_root(btree, node) ?
231 0 : NILFS_BTREE_NODE_EXTRA_PAD_SIZE));
232 }
233
234 static inline __le64 *
235 nilfs_btree_node_dptrs(const struct nilfs_btree *btree,
236 const struct nilfs_btree_node *node)
237 {
238 return (__le64 *)(nilfs_btree_node_dkeys(btree, node) +
239 nilfs_btree_node_nchildren_max(btree, node));
240 }
241
242 static inline __u64
243 nilfs_btree_node_get_key(const struct nilfs_btree *btree,
244 const struct nilfs_btree_node *node, int index)
245 {
246 return nilfs_bmap_dkey_to_key(*(nilfs_btree_node_dkeys(btree, node) +
247 index));
248 }
249
250 static inline void
251 nilfs_btree_node_set_key(struct nilfs_btree *btree,
252 struct nilfs_btree_node *node, int index, __u64 key)
253 {
254 *(nilfs_btree_node_dkeys(btree, node) + index) =
255 nilfs_bmap_key_to_dkey(key);
256 }
257
258 static inline __u64
259 nilfs_btree_node_get_ptr(const struct nilfs_btree *btree,
260 const struct nilfs_btree_node *node,
261 int index)
262 {
263 return nilfs_bmap_dptr_to_ptr(*(nilfs_btree_node_dptrs(btree, node) +
264 index));
265 }
266
267 static inline void
268 nilfs_btree_node_set_ptr(struct nilfs_btree *btree,
269 struct nilfs_btree_node *node,
270 int index,
271 __u64 ptr)
272 {
273 *(nilfs_btree_node_dptrs(btree, node) + index) =
274 nilfs_bmap_ptr_to_dptr(ptr);
275 }
276
277 static void nilfs_btree_node_init(struct nilfs_btree *btree,
278 struct nilfs_btree_node *node,
279 int flags, int level, int nchildren,
280 const __u64 *keys, const __u64 *ptrs)
281 {
282 __le64 *dkeys;
283 __le64 *dptrs;
284 int i;
285
286 nilfs_btree_node_set_flags(btree, node, flags);
287 nilfs_btree_node_set_level(btree, node, level);
288 nilfs_btree_node_set_nchildren(btree, node, nchildren);
289
290 dkeys = nilfs_btree_node_dkeys(btree, node);
291 dptrs = nilfs_btree_node_dptrs(btree, node);
292 for (i = 0; i < nchildren; i++) {
293 dkeys[i] = nilfs_bmap_key_to_dkey(keys[i]);
294 dptrs[i] = nilfs_bmap_ptr_to_dptr(ptrs[i]);
295 }
296 }
297
298 /* Assume the buffer heads corresponding to left and right are locked. */
299 static void nilfs_btree_node_move_left(struct nilfs_btree *btree,
300 struct nilfs_btree_node *left,
301 struct nilfs_btree_node *right,
302 int n)
303 {
304 __le64 *ldkeys, *rdkeys;
305 __le64 *ldptrs, *rdptrs;
306 int lnchildren, rnchildren;
307
308 ldkeys = nilfs_btree_node_dkeys(btree, left);
309 ldptrs = nilfs_btree_node_dptrs(btree, left);
310 lnchildren = nilfs_btree_node_get_nchildren(btree, left);
311
312 rdkeys = nilfs_btree_node_dkeys(btree, right);
313 rdptrs = nilfs_btree_node_dptrs(btree, right);
314 rnchildren = nilfs_btree_node_get_nchildren(btree, right);
315
316 memcpy(ldkeys + lnchildren, rdkeys, n * sizeof(*rdkeys));
317 memcpy(ldptrs + lnchildren, rdptrs, n * sizeof(*rdptrs));
318 memmove(rdkeys, rdkeys + n, (rnchildren - n) * sizeof(*rdkeys));
319 memmove(rdptrs, rdptrs + n, (rnchildren - n) * sizeof(*rdptrs));
320
321 lnchildren += n;
322 rnchildren -= n;
323 nilfs_btree_node_set_nchildren(btree, left, lnchildren);
324 nilfs_btree_node_set_nchildren(btree, right, rnchildren);
325 }
326
327 /* Assume that the buffer heads corresponding to left and right are locked. */
328 static void nilfs_btree_node_move_right(struct nilfs_btree *btree,
329 struct nilfs_btree_node *left,
330 struct nilfs_btree_node *right,
331 int n)
332 {
333 __le64 *ldkeys, *rdkeys;
334 __le64 *ldptrs, *rdptrs;
335 int lnchildren, rnchildren;
336
337 ldkeys = nilfs_btree_node_dkeys(btree, left);
338 ldptrs = nilfs_btree_node_dptrs(btree, left);
339 lnchildren = nilfs_btree_node_get_nchildren(btree, left);
340
341 rdkeys = nilfs_btree_node_dkeys(btree, right);
342 rdptrs = nilfs_btree_node_dptrs(btree, right);
343 rnchildren = nilfs_btree_node_get_nchildren(btree, right);
344
345 memmove(rdkeys + n, rdkeys, rnchildren * sizeof(*rdkeys));
346 memmove(rdptrs + n, rdptrs, rnchildren * sizeof(*rdptrs));
347 memcpy(rdkeys, ldkeys + lnchildren - n, n * sizeof(*rdkeys));
348 memcpy(rdptrs, ldptrs + lnchildren - n, n * sizeof(*rdptrs));
349
350 lnchildren -= n;
351 rnchildren += n;
352 nilfs_btree_node_set_nchildren(btree, left, lnchildren);
353 nilfs_btree_node_set_nchildren(btree, right, rnchildren);
354 }
355
356 /* Assume that the buffer head corresponding to node is locked. */
357 static void nilfs_btree_node_insert(struct nilfs_btree *btree,
358 struct nilfs_btree_node *node,
359 __u64 key, __u64 ptr, int index)
360 {
361 __le64 *dkeys;
362 __le64 *dptrs;
363 int nchildren;
364
365 dkeys = nilfs_btree_node_dkeys(btree, node);
366 dptrs = nilfs_btree_node_dptrs(btree, node);
367 nchildren = nilfs_btree_node_get_nchildren(btree, node);
368 if (index < nchildren) {
369 memmove(dkeys + index + 1, dkeys + index,
370 (nchildren - index) * sizeof(*dkeys));
371 memmove(dptrs + index + 1, dptrs + index,
372 (nchildren - index) * sizeof(*dptrs));
373 }
374 dkeys[index] = nilfs_bmap_key_to_dkey(key);
375 dptrs[index] = nilfs_bmap_ptr_to_dptr(ptr);
376 nchildren++;
377 nilfs_btree_node_set_nchildren(btree, node, nchildren);
378 }
379
380 /* Assume that the buffer head corresponding to node is locked. */
381 static void nilfs_btree_node_delete(struct nilfs_btree *btree,
382 struct nilfs_btree_node *node,
383 __u64 *keyp, __u64 *ptrp, int index)
384 {
385 __u64 key;
386 __u64 ptr;
387 __le64 *dkeys;
388 __le64 *dptrs;
389 int nchildren;
390
391 dkeys = nilfs_btree_node_dkeys(btree, node);
392 dptrs = nilfs_btree_node_dptrs(btree, node);
393 key = nilfs_bmap_dkey_to_key(dkeys[index]);
394 ptr = nilfs_bmap_dptr_to_ptr(dptrs[index]);
395 nchildren = nilfs_btree_node_get_nchildren(btree, node);
396 if (keyp != NULL)
397 *keyp = key;
398 if (ptrp != NULL)
399 *ptrp = ptr;
400
401 if (index < nchildren - 1) {
402 memmove(dkeys + index, dkeys + index + 1,
403 (nchildren - index - 1) * sizeof(*dkeys));
404 memmove(dptrs + index, dptrs + index + 1,
405 (nchildren - index - 1) * sizeof(*dptrs));
406 }
407 nchildren--;
408 nilfs_btree_node_set_nchildren(btree, node, nchildren);
409 }
410
411 static int nilfs_btree_node_lookup(const struct nilfs_btree *btree,
412 const struct nilfs_btree_node *node,
413 __u64 key, int *indexp)
414 {
415 __u64 nkey;
416 int index, low, high, s;
417
418 /* binary search */
419 low = 0;
420 high = nilfs_btree_node_get_nchildren(btree, node) - 1;
421 index = 0;
422 s = 0;
423 while (low <= high) {
424 index = (low + high) / 2;
425 nkey = nilfs_btree_node_get_key(btree, node, index);
426 if (nkey == key) {
427 s = 0;
428 goto out;
429 } else if (nkey < key) {
430 low = index + 1;
431 s = -1;
432 } else {
433 high = index - 1;
434 s = 1;
435 }
436 }
437
438 /* adjust index */
439 if (nilfs_btree_node_get_level(btree, node) >
440 NILFS_BTREE_LEVEL_NODE_MIN) {
441 if ((s > 0) && (index > 0))
442 index--;
443 } else if (s < 0)
444 index++;
445
446 out:
447 *indexp = index;
448
449 return s == 0;
450 }
451
452 static inline struct nilfs_btree_node *
453 nilfs_btree_get_root(const struct nilfs_btree *btree)
454 {
455 return (struct nilfs_btree_node *)btree->bt_bmap.b_u.u_data;
456 }
457
458 static inline struct nilfs_btree_node *
459 nilfs_btree_get_nonroot_node(const struct nilfs_btree *btree,
460 const struct nilfs_btree_path *path,
461 int level)
462 {
463 return (struct nilfs_btree_node *)path[level].bp_bh->b_data;
464 }
465
466 static inline struct nilfs_btree_node *
467 nilfs_btree_get_sib_node(const struct nilfs_btree *btree,
468 const struct nilfs_btree_path *path,
469 int level)
470 {
471 return (struct nilfs_btree_node *)path[level].bp_sib_bh->b_data;
472 }
473
474 static inline int nilfs_btree_height(const struct nilfs_btree *btree)
475 {
476 return nilfs_btree_node_get_level(btree, nilfs_btree_get_root(btree))
477 + 1;
478 }
479
480 static inline struct nilfs_btree_node *
481 nilfs_btree_get_node(const struct nilfs_btree *btree,
482 const struct nilfs_btree_path *path,
483 int level)
484 {
485 return (level == nilfs_btree_height(btree) - 1) ?
486 nilfs_btree_get_root(btree) :
487 nilfs_btree_get_nonroot_node(btree, path, level);
488 }
489
490 static int nilfs_btree_do_lookup(const struct nilfs_btree *btree,
491 struct nilfs_btree_path *path,
492 __u64 key, __u64 *ptrp, int minlevel)
493 {
494 struct nilfs_btree_node *node;
495 __u64 ptr;
496 int level, index, found, ret;
497
498 node = nilfs_btree_get_root(btree);
499 level = nilfs_btree_node_get_level(btree, node);
500 if ((level < minlevel) ||
501 (nilfs_btree_node_get_nchildren(btree, node) <= 0))
502 return -ENOENT;
503
504 found = nilfs_btree_node_lookup(btree, node, key, &index);
505 ptr = nilfs_btree_node_get_ptr(btree, node, index);
506 path[level].bp_bh = NULL;
507 path[level].bp_index = index;
508
509 for (level--; level >= minlevel; level--) {
510 ret = nilfs_btree_get_block(btree, ptr, &path[level].bp_bh);
511 if (ret < 0)
512 return ret;
513 node = nilfs_btree_get_nonroot_node(btree, path, level);
514 BUG_ON(level != nilfs_btree_node_get_level(btree, node));
515 if (!found)
516 found = nilfs_btree_node_lookup(btree, node, key,
517 &index);
518 else
519 index = 0;
520 if (index < nilfs_btree_node_nchildren_max(btree, node))
521 ptr = nilfs_btree_node_get_ptr(btree, node, index);
522 else {
523 WARN_ON(found || level != NILFS_BTREE_LEVEL_NODE_MIN);
524 /* insert */
525 ptr = NILFS_BMAP_INVALID_PTR;
526 }
527 path[level].bp_index = index;
528 }
529 if (!found)
530 return -ENOENT;
531
532 if (ptrp != NULL)
533 *ptrp = ptr;
534
535 return 0;
536 }
537
538 static int nilfs_btree_do_lookup_last(const struct nilfs_btree *btree,
539 struct nilfs_btree_path *path,
540 __u64 *keyp, __u64 *ptrp)
541 {
542 struct nilfs_btree_node *node;
543 __u64 ptr;
544 int index, level, ret;
545
546 node = nilfs_btree_get_root(btree);
547 index = nilfs_btree_node_get_nchildren(btree, node) - 1;
548 if (index < 0)
549 return -ENOENT;
550 level = nilfs_btree_node_get_level(btree, node);
551 ptr = nilfs_btree_node_get_ptr(btree, node, index);
552 path[level].bp_bh = NULL;
553 path[level].bp_index = index;
554
555 for (level--; level > 0; level--) {
556 ret = nilfs_btree_get_block(btree, ptr, &path[level].bp_bh);
557 if (ret < 0)
558 return ret;
559 node = nilfs_btree_get_nonroot_node(btree, path, level);
560 BUG_ON(level != nilfs_btree_node_get_level(btree, node));
561 index = nilfs_btree_node_get_nchildren(btree, node) - 1;
562 ptr = nilfs_btree_node_get_ptr(btree, node, index);
563 path[level].bp_index = index;
564 }
565
566 if (keyp != NULL)
567 *keyp = nilfs_btree_node_get_key(btree, node, index);
568 if (ptrp != NULL)
569 *ptrp = ptr;
570
571 return 0;
572 }
573
574 static int nilfs_btree_lookup(const struct nilfs_bmap *bmap,
575 __u64 key, int level, __u64 *ptrp)
576 {
577 struct nilfs_btree *btree;
578 struct nilfs_btree_path *path;
579 __u64 ptr;
580 int ret;
581
582 btree = (struct nilfs_btree *)bmap;
583 path = nilfs_btree_alloc_path(btree);
584 if (path == NULL)
585 return -ENOMEM;
586 nilfs_btree_init_path(btree, path);
587
588 ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level);
589
590 if (ptrp != NULL)
591 *ptrp = ptr;
592
593 nilfs_btree_clear_path(btree, path);
594 nilfs_btree_free_path(btree, path);
595
596 return ret;
597 }
598
599 static int nilfs_btree_lookup_contig(const struct nilfs_bmap *bmap,
600 __u64 key, __u64 *ptrp, unsigned maxblocks)
601 {
602 struct nilfs_btree *btree = (struct nilfs_btree *)bmap;
603 struct nilfs_btree_path *path;
604 struct nilfs_btree_node *node;
605 struct inode *dat = NULL;
606 __u64 ptr, ptr2;
607 sector_t blocknr;
608 int level = NILFS_BTREE_LEVEL_NODE_MIN;
609 int ret, cnt, index, maxlevel;
610
611 path = nilfs_btree_alloc_path(btree);
612 if (path == NULL)
613 return -ENOMEM;
614 nilfs_btree_init_path(btree, path);
615 ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level);
616 if (ret < 0)
617 goto out;
618
619 if (NILFS_BMAP_USE_VBN(bmap)) {
620 dat = nilfs_bmap_get_dat(bmap);
621 ret = nilfs_dat_translate(dat, ptr, &blocknr);
622 if (ret < 0)
623 goto out;
624 ptr = blocknr;
625 }
626 cnt = 1;
627 if (cnt == maxblocks)
628 goto end;
629
630 maxlevel = nilfs_btree_height(btree) - 1;
631 node = nilfs_btree_get_node(btree, path, level);
632 index = path[level].bp_index + 1;
633 for (;;) {
634 while (index < nilfs_btree_node_get_nchildren(btree, node)) {
635 if (nilfs_btree_node_get_key(btree, node, index) !=
636 key + cnt)
637 goto end;
638 ptr2 = nilfs_btree_node_get_ptr(btree, node, index);
639 if (dat) {
640 ret = nilfs_dat_translate(dat, ptr2, &blocknr);
641 if (ret < 0)
642 goto out;
643 ptr2 = blocknr;
644 }
645 if (ptr2 != ptr + cnt || ++cnt == maxblocks)
646 goto end;
647 index++;
648 continue;
649 }
650 if (level == maxlevel)
651 break;
652
653 /* look-up right sibling node */
654 node = nilfs_btree_get_node(btree, path, level + 1);
655 index = path[level + 1].bp_index + 1;
656 if (index >= nilfs_btree_node_get_nchildren(btree, node) ||
657 nilfs_btree_node_get_key(btree, node, index) != key + cnt)
658 break;
659 ptr2 = nilfs_btree_node_get_ptr(btree, node, index);
660 path[level + 1].bp_index = index;
661
662 brelse(path[level].bp_bh);
663 path[level].bp_bh = NULL;
664 ret = nilfs_btree_get_block(btree, ptr2, &path[level].bp_bh);
665 if (ret < 0)
666 goto out;
667 node = nilfs_btree_get_nonroot_node(btree, path, level);
668 index = 0;
669 path[level].bp_index = index;
670 }
671 end:
672 *ptrp = ptr;
673 ret = cnt;
674 out:
675 nilfs_btree_clear_path(btree, path);
676 nilfs_btree_free_path(btree, path);
677 return ret;
678 }
679
680 static void nilfs_btree_promote_key(struct nilfs_btree *btree,
681 struct nilfs_btree_path *path,
682 int level, __u64 key)
683 {
684 if (level < nilfs_btree_height(btree) - 1) {
685 do {
686 lock_buffer(path[level].bp_bh);
687 nilfs_btree_node_set_key(
688 btree,
689 nilfs_btree_get_nonroot_node(
690 btree, path, level),
691 path[level].bp_index, key);
692 if (!buffer_dirty(path[level].bp_bh))
693 nilfs_btnode_mark_dirty(path[level].bp_bh);
694 unlock_buffer(path[level].bp_bh);
695 } while ((path[level].bp_index == 0) &&
696 (++level < nilfs_btree_height(btree) - 1));
697 }
698
699 /* root */
700 if (level == nilfs_btree_height(btree) - 1) {
701 nilfs_btree_node_set_key(btree,
702 nilfs_btree_get_root(btree),
703 path[level].bp_index, key);
704 }
705 }
706
707 static void nilfs_btree_do_insert(struct nilfs_btree *btree,
708 struct nilfs_btree_path *path,
709 int level, __u64 *keyp, __u64 *ptrp)
710 {
711 struct nilfs_btree_node *node;
712
713 if (level < nilfs_btree_height(btree) - 1) {
714 lock_buffer(path[level].bp_bh);
715 node = nilfs_btree_get_nonroot_node(btree, path, level);
716 nilfs_btree_node_insert(btree, node, *keyp, *ptrp,
717 path[level].bp_index);
718 if (!buffer_dirty(path[level].bp_bh))
719 nilfs_btnode_mark_dirty(path[level].bp_bh);
720 unlock_buffer(path[level].bp_bh);
721
722 if (path[level].bp_index == 0)
723 nilfs_btree_promote_key(btree, path, level + 1,
724 nilfs_btree_node_get_key(
725 btree, node, 0));
726 } else {
727 node = nilfs_btree_get_root(btree);
728 nilfs_btree_node_insert(btree, node, *keyp, *ptrp,
729 path[level].bp_index);
730 }
731 }
732
733 static void nilfs_btree_carry_left(struct nilfs_btree *btree,
734 struct nilfs_btree_path *path,
735 int level, __u64 *keyp, __u64 *ptrp)
736 {
737 struct nilfs_btree_node *node, *left;
738 int nchildren, lnchildren, n, move;
739
740 lock_buffer(path[level].bp_bh);
741 lock_buffer(path[level].bp_sib_bh);
742
743 node = nilfs_btree_get_nonroot_node(btree, path, level);
744 left = nilfs_btree_get_sib_node(btree, path, level);
745 nchildren = nilfs_btree_node_get_nchildren(btree, node);
746 lnchildren = nilfs_btree_node_get_nchildren(btree, left);
747 move = 0;
748
749 n = (nchildren + lnchildren + 1) / 2 - lnchildren;
750 if (n > path[level].bp_index) {
751 /* move insert point */
752 n--;
753 move = 1;
754 }
755
756 nilfs_btree_node_move_left(btree, left, node, n);
757
758 if (!buffer_dirty(path[level].bp_bh))
759 nilfs_btnode_mark_dirty(path[level].bp_bh);
760 if (!buffer_dirty(path[level].bp_sib_bh))
761 nilfs_btnode_mark_dirty(path[level].bp_sib_bh);
762
763 unlock_buffer(path[level].bp_bh);
764 unlock_buffer(path[level].bp_sib_bh);
765
766 nilfs_btree_promote_key(btree, path, level + 1,
767 nilfs_btree_node_get_key(btree, node, 0));
768
769 if (move) {
770 brelse(path[level].bp_bh);
771 path[level].bp_bh = path[level].bp_sib_bh;
772 path[level].bp_sib_bh = NULL;
773 path[level].bp_index += lnchildren;
774 path[level + 1].bp_index--;
775 } else {
776 brelse(path[level].bp_sib_bh);
777 path[level].bp_sib_bh = NULL;
778 path[level].bp_index -= n;
779 }
780
781 nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
782 }
783
784 static void nilfs_btree_carry_right(struct nilfs_btree *btree,
785 struct nilfs_btree_path *path,
786 int level, __u64 *keyp, __u64 *ptrp)
787 {
788 struct nilfs_btree_node *node, *right;
789 int nchildren, rnchildren, n, move;
790
791 lock_buffer(path[level].bp_bh);
792 lock_buffer(path[level].bp_sib_bh);
793
794 node = nilfs_btree_get_nonroot_node(btree, path, level);
795 right = nilfs_btree_get_sib_node(btree, path, level);
796 nchildren = nilfs_btree_node_get_nchildren(btree, node);
797 rnchildren = nilfs_btree_node_get_nchildren(btree, right);
798 move = 0;
799
800 n = (nchildren + rnchildren + 1) / 2 - rnchildren;
801 if (n > nchildren - path[level].bp_index) {
802 /* move insert point */
803 n--;
804 move = 1;
805 }
806
807 nilfs_btree_node_move_right(btree, node, right, n);
808
809 if (!buffer_dirty(path[level].bp_bh))
810 nilfs_btnode_mark_dirty(path[level].bp_bh);
811 if (!buffer_dirty(path[level].bp_sib_bh))
812 nilfs_btnode_mark_dirty(path[level].bp_sib_bh);
813
814 unlock_buffer(path[level].bp_bh);
815 unlock_buffer(path[level].bp_sib_bh);
816
817 path[level + 1].bp_index++;
818 nilfs_btree_promote_key(btree, path, level + 1,
819 nilfs_btree_node_get_key(btree, right, 0));
820 path[level + 1].bp_index--;
821
822 if (move) {
823 brelse(path[level].bp_bh);
824 path[level].bp_bh = path[level].bp_sib_bh;
825 path[level].bp_sib_bh = NULL;
826 path[level].bp_index -=
827 nilfs_btree_node_get_nchildren(btree, node);
828 path[level + 1].bp_index++;
829 } else {
830 brelse(path[level].bp_sib_bh);
831 path[level].bp_sib_bh = NULL;
832 }
833
834 nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
835 }
836
837 static void nilfs_btree_split(struct nilfs_btree *btree,
838 struct nilfs_btree_path *path,
839 int level, __u64 *keyp, __u64 *ptrp)
840 {
841 struct nilfs_btree_node *node, *right;
842 __u64 newkey;
843 __u64 newptr;
844 int nchildren, n, move;
845
846 lock_buffer(path[level].bp_bh);
847 lock_buffer(path[level].bp_sib_bh);
848
849 node = nilfs_btree_get_nonroot_node(btree, path, level);
850 right = nilfs_btree_get_sib_node(btree, path, level);
851 nchildren = nilfs_btree_node_get_nchildren(btree, node);
852 move = 0;
853
854 n = (nchildren + 1) / 2;
855 if (n > nchildren - path[level].bp_index) {
856 n--;
857 move = 1;
858 }
859
860 nilfs_btree_node_move_right(btree, node, right, n);
861
862 if (!buffer_dirty(path[level].bp_bh))
863 nilfs_btnode_mark_dirty(path[level].bp_bh);
864 if (!buffer_dirty(path[level].bp_sib_bh))
865 nilfs_btnode_mark_dirty(path[level].bp_sib_bh);
866
867 unlock_buffer(path[level].bp_bh);
868 unlock_buffer(path[level].bp_sib_bh);
869
870 newkey = nilfs_btree_node_get_key(btree, right, 0);
871 newptr = path[level].bp_newreq.bpr_ptr;
872
873 if (move) {
874 path[level].bp_index -=
875 nilfs_btree_node_get_nchildren(btree, node);
876 nilfs_btree_node_insert(btree, right, *keyp, *ptrp,
877 path[level].bp_index);
878
879 *keyp = nilfs_btree_node_get_key(btree, right, 0);
880 *ptrp = path[level].bp_newreq.bpr_ptr;
881
882 brelse(path[level].bp_bh);
883 path[level].bp_bh = path[level].bp_sib_bh;
884 path[level].bp_sib_bh = NULL;
885 } else {
886 nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
887
888 *keyp = nilfs_btree_node_get_key(btree, right, 0);
889 *ptrp = path[level].bp_newreq.bpr_ptr;
890
891 brelse(path[level].bp_sib_bh);
892 path[level].bp_sib_bh = NULL;
893 }
894
895 path[level + 1].bp_index++;
896 }
897
898 static void nilfs_btree_grow(struct nilfs_btree *btree,
899 struct nilfs_btree_path *path,
900 int level, __u64 *keyp, __u64 *ptrp)
901 {
902 struct nilfs_btree_node *root, *child;
903 int n;
904
905 lock_buffer(path[level].bp_sib_bh);
906
907 root = nilfs_btree_get_root(btree);
908 child = nilfs_btree_get_sib_node(btree, path, level);
909
910 n = nilfs_btree_node_get_nchildren(btree, root);
911
912 nilfs_btree_node_move_right(btree, root, child, n);
913 nilfs_btree_node_set_level(btree, root, level + 1);
914
915 if (!buffer_dirty(path[level].bp_sib_bh))
916 nilfs_btnode_mark_dirty(path[level].bp_sib_bh);
917
918 unlock_buffer(path[level].bp_sib_bh);
919
920 path[level].bp_bh = path[level].bp_sib_bh;
921 path[level].bp_sib_bh = NULL;
922
923 nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
924
925 *keyp = nilfs_btree_node_get_key(btree, child, 0);
926 *ptrp = path[level].bp_newreq.bpr_ptr;
927 }
928
929 static __u64 nilfs_btree_find_near(const struct nilfs_btree *btree,
930 const struct nilfs_btree_path *path)
931 {
932 struct nilfs_btree_node *node;
933 int level;
934
935 if (path == NULL)
936 return NILFS_BMAP_INVALID_PTR;
937
938 /* left sibling */
939 level = NILFS_BTREE_LEVEL_NODE_MIN;
940 if (path[level].bp_index > 0) {
941 node = nilfs_btree_get_node(btree, path, level);
942 return nilfs_btree_node_get_ptr(btree, node,
943 path[level].bp_index - 1);
944 }
945
946 /* parent */
947 level = NILFS_BTREE_LEVEL_NODE_MIN + 1;
948 if (level <= nilfs_btree_height(btree) - 1) {
949 node = nilfs_btree_get_node(btree, path, level);
950 return nilfs_btree_node_get_ptr(btree, node,
951 path[level].bp_index);
952 }
953
954 return NILFS_BMAP_INVALID_PTR;
955 }
956
957 static __u64 nilfs_btree_find_target_v(const struct nilfs_btree *btree,
958 const struct nilfs_btree_path *path,
959 __u64 key)
960 {
961 __u64 ptr;
962
963 ptr = nilfs_bmap_find_target_seq(&btree->bt_bmap, key);
964 if (ptr != NILFS_BMAP_INVALID_PTR)
965 /* sequential access */
966 return ptr;
967 else {
968 ptr = nilfs_btree_find_near(btree, path);
969 if (ptr != NILFS_BMAP_INVALID_PTR)
970 /* near */
971 return ptr;
972 }
973 /* block group */
974 return nilfs_bmap_find_target_in_group(&btree->bt_bmap);
975 }
976
977 static void nilfs_btree_set_target_v(struct nilfs_btree *btree, __u64 key,
978 __u64 ptr)
979 {
980 btree->bt_bmap.b_last_allocated_key = key;
981 btree->bt_bmap.b_last_allocated_ptr = ptr;
982 }
983
984 static int nilfs_btree_prepare_insert(struct nilfs_btree *btree,
985 struct nilfs_btree_path *path,
986 int *levelp, __u64 key, __u64 ptr,
987 struct nilfs_bmap_stats *stats)
988 {
989 struct buffer_head *bh;
990 struct nilfs_btree_node *node, *parent, *sib;
991 __u64 sibptr;
992 int pindex, level, ret;
993
994 stats->bs_nblocks = 0;
995 level = NILFS_BTREE_LEVEL_DATA;
996
997 /* allocate a new ptr for data block */
998 if (NILFS_BMAP_USE_VBN(&btree->bt_bmap))
999 path[level].bp_newreq.bpr_ptr =
1000 nilfs_btree_find_target_v(btree, path, key);
1001
1002 ret = nilfs_bmap_prepare_alloc_ptr(&btree->bt_bmap,
1003 &path[level].bp_newreq);
1004 if (ret < 0)
1005 goto err_out_data;
1006
1007 for (level = NILFS_BTREE_LEVEL_NODE_MIN;
1008 level < nilfs_btree_height(btree) - 1;
1009 level++) {
1010 node = nilfs_btree_get_nonroot_node(btree, path, level);
1011 if (nilfs_btree_node_get_nchildren(btree, node) <
1012 nilfs_btree_node_nchildren_max(btree, node)) {
1013 path[level].bp_op = nilfs_btree_do_insert;
1014 stats->bs_nblocks++;
1015 goto out;
1016 }
1017
1018 parent = nilfs_btree_get_node(btree, path, level + 1);
1019 pindex = path[level + 1].bp_index;
1020
1021 /* left sibling */
1022 if (pindex > 0) {
1023 sibptr = nilfs_btree_node_get_ptr(btree, parent,
1024 pindex - 1);
1025 ret = nilfs_btree_get_block(btree, sibptr, &bh);
1026 if (ret < 0)
1027 goto err_out_child_node;
1028 sib = (struct nilfs_btree_node *)bh->b_data;
1029 if (nilfs_btree_node_get_nchildren(btree, sib) <
1030 nilfs_btree_node_nchildren_max(btree, sib)) {
1031 path[level].bp_sib_bh = bh;
1032 path[level].bp_op = nilfs_btree_carry_left;
1033 stats->bs_nblocks++;
1034 goto out;
1035 } else
1036 brelse(bh);
1037 }
1038
1039 /* right sibling */
1040 if (pindex <
1041 nilfs_btree_node_get_nchildren(btree, parent) - 1) {
1042 sibptr = nilfs_btree_node_get_ptr(btree, parent,
1043 pindex + 1);
1044 ret = nilfs_btree_get_block(btree, sibptr, &bh);
1045 if (ret < 0)
1046 goto err_out_child_node;
1047 sib = (struct nilfs_btree_node *)bh->b_data;
1048 if (nilfs_btree_node_get_nchildren(btree, sib) <
1049 nilfs_btree_node_nchildren_max(btree, sib)) {
1050 path[level].bp_sib_bh = bh;
1051 path[level].bp_op = nilfs_btree_carry_right;
1052 stats->bs_nblocks++;
1053 goto out;
1054 } else
1055 brelse(bh);
1056 }
1057
1058 /* split */
1059 path[level].bp_newreq.bpr_ptr =
1060 path[level - 1].bp_newreq.bpr_ptr + 1;
1061 ret = nilfs_bmap_prepare_alloc_ptr(&btree->bt_bmap,
1062 &path[level].bp_newreq);
1063 if (ret < 0)
1064 goto err_out_child_node;
1065 ret = nilfs_btree_get_new_block(btree,
1066 path[level].bp_newreq.bpr_ptr,
1067 &bh);
1068 if (ret < 0)
1069 goto err_out_curr_node;
1070
1071 stats->bs_nblocks++;
1072
1073 lock_buffer(bh);
1074 nilfs_btree_node_init(btree,
1075 (struct nilfs_btree_node *)bh->b_data,
1076 0, level, 0, NULL, NULL);
1077 unlock_buffer(bh);
1078 path[level].bp_sib_bh = bh;
1079 path[level].bp_op = nilfs_btree_split;
1080 }
1081
1082 /* root */
1083 node = nilfs_btree_get_root(btree);
1084 if (nilfs_btree_node_get_nchildren(btree, node) <
1085 nilfs_btree_node_nchildren_max(btree, node)) {
1086 path[level].bp_op = nilfs_btree_do_insert;
1087 stats->bs_nblocks++;
1088 goto out;
1089 }
1090
1091 /* grow */
1092 path[level].bp_newreq.bpr_ptr = path[level - 1].bp_newreq.bpr_ptr + 1;
1093 ret = nilfs_bmap_prepare_alloc_ptr(&btree->bt_bmap,
1094 &path[level].bp_newreq);
1095 if (ret < 0)
1096 goto err_out_child_node;
1097 ret = nilfs_btree_get_new_block(btree, path[level].bp_newreq.bpr_ptr,
1098 &bh);
1099 if (ret < 0)
1100 goto err_out_curr_node;
1101
1102 lock_buffer(bh);
1103 nilfs_btree_node_init(btree, (struct nilfs_btree_node *)bh->b_data,
1104 0, level, 0, NULL, NULL);
1105 unlock_buffer(bh);
1106 path[level].bp_sib_bh = bh;
1107 path[level].bp_op = nilfs_btree_grow;
1108
1109 level++;
1110 path[level].bp_op = nilfs_btree_do_insert;
1111
1112 /* a newly-created node block and a data block are added */
1113 stats->bs_nblocks += 2;
1114
1115 /* success */
1116 out:
1117 *levelp = level;
1118 return ret;
1119
1120 /* error */
1121 err_out_curr_node:
1122 nilfs_bmap_abort_alloc_ptr(&btree->bt_bmap, &path[level].bp_newreq);
1123 err_out_child_node:
1124 for (level--; level > NILFS_BTREE_LEVEL_DATA; level--) {
1125 nilfs_btnode_delete(path[level].bp_sib_bh);
1126 nilfs_bmap_abort_alloc_ptr(&btree->bt_bmap,
1127 &path[level].bp_newreq);
1128
1129 }
1130
1131 nilfs_bmap_abort_alloc_ptr(&btree->bt_bmap, &path[level].bp_newreq);
1132 err_out_data:
1133 *levelp = level;
1134 stats->bs_nblocks = 0;
1135 return ret;
1136 }
1137
1138 static void nilfs_btree_commit_insert(struct nilfs_btree *btree,
1139 struct nilfs_btree_path *path,
1140 int maxlevel, __u64 key, __u64 ptr)
1141 {
1142 int level;
1143
1144 set_buffer_nilfs_volatile((struct buffer_head *)((unsigned long)ptr));
1145 ptr = path[NILFS_BTREE_LEVEL_DATA].bp_newreq.bpr_ptr;
1146 if (NILFS_BMAP_USE_VBN(&btree->bt_bmap))
1147 nilfs_btree_set_target_v(btree, key, ptr);
1148
1149 for (level = NILFS_BTREE_LEVEL_NODE_MIN; level <= maxlevel; level++) {
1150 nilfs_bmap_commit_alloc_ptr(&btree->bt_bmap,
1151 &path[level - 1].bp_newreq);
1152 path[level].bp_op(btree, path, level, &key, &ptr);
1153 }
1154
1155 if (!nilfs_bmap_dirty(&btree->bt_bmap))
1156 nilfs_bmap_set_dirty(&btree->bt_bmap);
1157 }
1158
1159 static int nilfs_btree_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
1160 {
1161 struct nilfs_btree *btree;
1162 struct nilfs_btree_path *path;
1163 struct nilfs_bmap_stats stats;
1164 int level, ret;
1165
1166 btree = (struct nilfs_btree *)bmap;
1167 path = nilfs_btree_alloc_path(btree);
1168 if (path == NULL)
1169 return -ENOMEM;
1170 nilfs_btree_init_path(btree, path);
1171
1172 ret = nilfs_btree_do_lookup(btree, path, key, NULL,
1173 NILFS_BTREE_LEVEL_NODE_MIN);
1174 if (ret != -ENOENT) {
1175 if (ret == 0)
1176 ret = -EEXIST;
1177 goto out;
1178 }
1179
1180 ret = nilfs_btree_prepare_insert(btree, path, &level, key, ptr, &stats);
1181 if (ret < 0)
1182 goto out;
1183 nilfs_btree_commit_insert(btree, path, level, key, ptr);
1184 nilfs_bmap_add_blocks(bmap, stats.bs_nblocks);
1185
1186 out:
1187 nilfs_btree_clear_path(btree, path);
1188 nilfs_btree_free_path(btree, path);
1189 return ret;
1190 }
1191
1192 static void nilfs_btree_do_delete(struct nilfs_btree *btree,
1193 struct nilfs_btree_path *path,
1194 int level, __u64 *keyp, __u64 *ptrp)
1195 {
1196 struct nilfs_btree_node *node;
1197
1198 if (level < nilfs_btree_height(btree) - 1) {
1199 lock_buffer(path[level].bp_bh);
1200 node = nilfs_btree_get_nonroot_node(btree, path, level);
1201 nilfs_btree_node_delete(btree, node, keyp, ptrp,
1202 path[level].bp_index);
1203 if (!buffer_dirty(path[level].bp_bh))
1204 nilfs_btnode_mark_dirty(path[level].bp_bh);
1205 unlock_buffer(path[level].bp_bh);
1206 if (path[level].bp_index == 0)
1207 nilfs_btree_promote_key(btree, path, level + 1,
1208 nilfs_btree_node_get_key(btree, node, 0));
1209 } else {
1210 node = nilfs_btree_get_root(btree);
1211 nilfs_btree_node_delete(btree, node, keyp, ptrp,
1212 path[level].bp_index);
1213 }
1214 }
1215
1216 static void nilfs_btree_borrow_left(struct nilfs_btree *btree,
1217 struct nilfs_btree_path *path,
1218 int level, __u64 *keyp, __u64 *ptrp)
1219 {
1220 struct nilfs_btree_node *node, *left;
1221 int nchildren, lnchildren, n;
1222
1223 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1224
1225 lock_buffer(path[level].bp_bh);
1226 lock_buffer(path[level].bp_sib_bh);
1227
1228 node = nilfs_btree_get_nonroot_node(btree, path, level);
1229 left = nilfs_btree_get_sib_node(btree, path, level);
1230 nchildren = nilfs_btree_node_get_nchildren(btree, node);
1231 lnchildren = nilfs_btree_node_get_nchildren(btree, left);
1232
1233 n = (nchildren + lnchildren) / 2 - nchildren;
1234
1235 nilfs_btree_node_move_right(btree, left, node, n);
1236
1237 if (!buffer_dirty(path[level].bp_bh))
1238 nilfs_btnode_mark_dirty(path[level].bp_bh);
1239 if (!buffer_dirty(path[level].bp_sib_bh))
1240 nilfs_btnode_mark_dirty(path[level].bp_sib_bh);
1241
1242 unlock_buffer(path[level].bp_bh);
1243 unlock_buffer(path[level].bp_sib_bh);
1244
1245 nilfs_btree_promote_key(btree, path, level + 1,
1246 nilfs_btree_node_get_key(btree, node, 0));
1247
1248 brelse(path[level].bp_sib_bh);
1249 path[level].bp_sib_bh = NULL;
1250 path[level].bp_index += n;
1251 }
1252
1253 static void nilfs_btree_borrow_right(struct nilfs_btree *btree,
1254 struct nilfs_btree_path *path,
1255 int level, __u64 *keyp, __u64 *ptrp)
1256 {
1257 struct nilfs_btree_node *node, *right;
1258 int nchildren, rnchildren, n;
1259
1260 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1261
1262 lock_buffer(path[level].bp_bh);
1263 lock_buffer(path[level].bp_sib_bh);
1264
1265 node = nilfs_btree_get_nonroot_node(btree, path, level);
1266 right = nilfs_btree_get_sib_node(btree, path, level);
1267 nchildren = nilfs_btree_node_get_nchildren(btree, node);
1268 rnchildren = nilfs_btree_node_get_nchildren(btree, right);
1269
1270 n = (nchildren + rnchildren) / 2 - nchildren;
1271
1272 nilfs_btree_node_move_left(btree, node, right, n);
1273
1274 if (!buffer_dirty(path[level].bp_bh))
1275 nilfs_btnode_mark_dirty(path[level].bp_bh);
1276 if (!buffer_dirty(path[level].bp_sib_bh))
1277 nilfs_btnode_mark_dirty(path[level].bp_sib_bh);
1278
1279 unlock_buffer(path[level].bp_bh);
1280 unlock_buffer(path[level].bp_sib_bh);
1281
1282 path[level + 1].bp_index++;
1283 nilfs_btree_promote_key(btree, path, level + 1,
1284 nilfs_btree_node_get_key(btree, right, 0));
1285 path[level + 1].bp_index--;
1286
1287 brelse(path[level].bp_sib_bh);
1288 path[level].bp_sib_bh = NULL;
1289 }
1290
1291 static void nilfs_btree_concat_left(struct nilfs_btree *btree,
1292 struct nilfs_btree_path *path,
1293 int level, __u64 *keyp, __u64 *ptrp)
1294 {
1295 struct nilfs_btree_node *node, *left;
1296 int n;
1297
1298 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1299
1300 lock_buffer(path[level].bp_bh);
1301 lock_buffer(path[level].bp_sib_bh);
1302
1303 node = nilfs_btree_get_nonroot_node(btree, path, level);
1304 left = nilfs_btree_get_sib_node(btree, path, level);
1305
1306 n = nilfs_btree_node_get_nchildren(btree, node);
1307
1308 nilfs_btree_node_move_left(btree, left, node, n);
1309
1310 if (!buffer_dirty(path[level].bp_sib_bh))
1311 nilfs_btnode_mark_dirty(path[level].bp_sib_bh);
1312
1313 unlock_buffer(path[level].bp_bh);
1314 unlock_buffer(path[level].bp_sib_bh);
1315
1316 nilfs_btnode_delete(path[level].bp_bh);
1317 path[level].bp_bh = path[level].bp_sib_bh;
1318 path[level].bp_sib_bh = NULL;
1319 path[level].bp_index += nilfs_btree_node_get_nchildren(btree, left);
1320 }
1321
1322 static void nilfs_btree_concat_right(struct nilfs_btree *btree,
1323 struct nilfs_btree_path *path,
1324 int level, __u64 *keyp, __u64 *ptrp)
1325 {
1326 struct nilfs_btree_node *node, *right;
1327 int n;
1328
1329 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1330
1331 lock_buffer(path[level].bp_bh);
1332 lock_buffer(path[level].bp_sib_bh);
1333
1334 node = nilfs_btree_get_nonroot_node(btree, path, level);
1335 right = nilfs_btree_get_sib_node(btree, path, level);
1336
1337 n = nilfs_btree_node_get_nchildren(btree, right);
1338
1339 nilfs_btree_node_move_left(btree, node, right, n);
1340
1341 if (!buffer_dirty(path[level].bp_bh))
1342 nilfs_btnode_mark_dirty(path[level].bp_bh);
1343
1344 unlock_buffer(path[level].bp_bh);
1345 unlock_buffer(path[level].bp_sib_bh);
1346
1347 nilfs_btnode_delete(path[level].bp_sib_bh);
1348 path[level].bp_sib_bh = NULL;
1349 path[level + 1].bp_index++;
1350 }
1351
1352 static void nilfs_btree_shrink(struct nilfs_btree *btree,
1353 struct nilfs_btree_path *path,
1354 int level, __u64 *keyp, __u64 *ptrp)
1355 {
1356 struct nilfs_btree_node *root, *child;
1357 int n;
1358
1359 nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1360
1361 lock_buffer(path[level].bp_bh);
1362 root = nilfs_btree_get_root(btree);
1363 child = nilfs_btree_get_nonroot_node(btree, path, level);
1364
1365 nilfs_btree_node_delete(btree, root, NULL, NULL, 0);
1366 nilfs_btree_node_set_level(btree, root, level);
1367 n = nilfs_btree_node_get_nchildren(btree, child);
1368 nilfs_btree_node_move_left(btree, root, child, n);
1369 unlock_buffer(path[level].bp_bh);
1370
1371 nilfs_btnode_delete(path[level].bp_bh);
1372 path[level].bp_bh = NULL;
1373 }
1374
1375
1376 static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
1377 struct nilfs_btree_path *path,
1378 int *levelp,
1379 struct nilfs_bmap_stats *stats)
1380 {
1381 struct buffer_head *bh;
1382 struct nilfs_btree_node *node, *parent, *sib;
1383 __u64 sibptr;
1384 int pindex, level, ret;
1385
1386 ret = 0;
1387 stats->bs_nblocks = 0;
1388 for (level = NILFS_BTREE_LEVEL_NODE_MIN;
1389 level < nilfs_btree_height(btree) - 1;
1390 level++) {
1391 node = nilfs_btree_get_nonroot_node(btree, path, level);
1392 path[level].bp_oldreq.bpr_ptr =
1393 nilfs_btree_node_get_ptr(btree, node,
1394 path[level].bp_index);
1395 ret = nilfs_bmap_prepare_end_ptr(&btree->bt_bmap,
1396 &path[level].bp_oldreq);
1397 if (ret < 0)
1398 goto err_out_child_node;
1399
1400 if (nilfs_btree_node_get_nchildren(btree, node) >
1401 nilfs_btree_node_nchildren_min(btree, node)) {
1402 path[level].bp_op = nilfs_btree_do_delete;
1403 stats->bs_nblocks++;
1404 goto out;
1405 }
1406
1407 parent = nilfs_btree_get_node(btree, path, level + 1);
1408 pindex = path[level + 1].bp_index;
1409
1410 if (pindex > 0) {
1411 /* left sibling */
1412 sibptr = nilfs_btree_node_get_ptr(btree, parent,
1413 pindex - 1);
1414 ret = nilfs_btree_get_block(btree, sibptr, &bh);
1415 if (ret < 0)
1416 goto err_out_curr_node;
1417 sib = (struct nilfs_btree_node *)bh->b_data;
1418 if (nilfs_btree_node_get_nchildren(btree, sib) >
1419 nilfs_btree_node_nchildren_min(btree, sib)) {
1420 path[level].bp_sib_bh = bh;
1421 path[level].bp_op = nilfs_btree_borrow_left;
1422 stats->bs_nblocks++;
1423 goto out;
1424 } else {
1425 path[level].bp_sib_bh = bh;
1426 path[level].bp_op = nilfs_btree_concat_left;
1427 stats->bs_nblocks++;
1428 /* continue; */
1429 }
1430 } else if (pindex <
1431 nilfs_btree_node_get_nchildren(btree, parent) - 1) {
1432 /* right sibling */
1433 sibptr = nilfs_btree_node_get_ptr(btree, parent,
1434 pindex + 1);
1435 ret = nilfs_btree_get_block(btree, sibptr, &bh);
1436 if (ret < 0)
1437 goto err_out_curr_node;
1438 sib = (struct nilfs_btree_node *)bh->b_data;
1439 if (nilfs_btree_node_get_nchildren(btree, sib) >
1440 nilfs_btree_node_nchildren_min(btree, sib)) {
1441 path[level].bp_sib_bh = bh;
1442 path[level].bp_op = nilfs_btree_borrow_right;
1443 stats->bs_nblocks++;
1444 goto out;
1445 } else {
1446 path[level].bp_sib_bh = bh;
1447 path[level].bp_op = nilfs_btree_concat_right;
1448 stats->bs_nblocks++;
1449 /* continue; */
1450 }
1451 } else {
1452 /* no siblings */
1453 /* the only child of the root node */
1454 WARN_ON(level != nilfs_btree_height(btree) - 2);
1455 if (nilfs_btree_node_get_nchildren(btree, node) - 1 <=
1456 NILFS_BTREE_ROOT_NCHILDREN_MAX) {
1457 path[level].bp_op = nilfs_btree_shrink;
1458 stats->bs_nblocks += 2;
1459 } else {
1460 path[level].bp_op = nilfs_btree_do_delete;
1461 stats->bs_nblocks++;
1462 }
1463
1464 goto out;
1465
1466 }
1467 }
1468
1469 node = nilfs_btree_get_root(btree);
1470 path[level].bp_oldreq.bpr_ptr =
1471 nilfs_btree_node_get_ptr(btree, node, path[level].bp_index);
1472
1473 ret = nilfs_bmap_prepare_end_ptr(&btree->bt_bmap,
1474 &path[level].bp_oldreq);
1475 if (ret < 0)
1476 goto err_out_child_node;
1477
1478 /* child of the root node is deleted */
1479 path[level].bp_op = nilfs_btree_do_delete;
1480 stats->bs_nblocks++;
1481
1482 /* success */
1483 out:
1484 *levelp = level;
1485 return ret;
1486
1487 /* error */
1488 err_out_curr_node:
1489 nilfs_bmap_abort_end_ptr(&btree->bt_bmap, &path[level].bp_oldreq);
1490 err_out_child_node:
1491 for (level--; level >= NILFS_BTREE_LEVEL_NODE_MIN; level--) {
1492 brelse(path[level].bp_sib_bh);
1493 nilfs_bmap_abort_end_ptr(&btree->bt_bmap,
1494 &path[level].bp_oldreq);
1495 }
1496 *levelp = level;
1497 stats->bs_nblocks = 0;
1498 return ret;
1499 }
1500
1501 static void nilfs_btree_commit_delete(struct nilfs_btree *btree,
1502 struct nilfs_btree_path *path,
1503 int maxlevel)
1504 {
1505 int level;
1506
1507 for (level = NILFS_BTREE_LEVEL_NODE_MIN; level <= maxlevel; level++) {
1508 nilfs_bmap_commit_end_ptr(&btree->bt_bmap,
1509 &path[level].bp_oldreq);
1510 path[level].bp_op(btree, path, level, NULL, NULL);
1511 }
1512
1513 if (!nilfs_bmap_dirty(&btree->bt_bmap))
1514 nilfs_bmap_set_dirty(&btree->bt_bmap);
1515 }
1516
1517 static int nilfs_btree_delete(struct nilfs_bmap *bmap, __u64 key)
1518
1519 {
1520 struct nilfs_btree *btree;
1521 struct nilfs_btree_path *path;
1522 struct nilfs_bmap_stats stats;
1523 int level, ret;
1524
1525 btree = (struct nilfs_btree *)bmap;
1526 path = nilfs_btree_alloc_path(btree);
1527 if (path == NULL)
1528 return -ENOMEM;
1529 nilfs_btree_init_path(btree, path);
1530 ret = nilfs_btree_do_lookup(btree, path, key, NULL,
1531 NILFS_BTREE_LEVEL_NODE_MIN);
1532 if (ret < 0)
1533 goto out;
1534
1535 ret = nilfs_btree_prepare_delete(btree, path, &level, &stats);
1536 if (ret < 0)
1537 goto out;
1538 nilfs_btree_commit_delete(btree, path, level);
1539 nilfs_bmap_sub_blocks(bmap, stats.bs_nblocks);
1540
1541 out:
1542 nilfs_btree_clear_path(btree, path);
1543 nilfs_btree_free_path(btree, path);
1544 return ret;
1545 }
1546
1547 static int nilfs_btree_last_key(const struct nilfs_bmap *bmap, __u64 *keyp)
1548 {
1549 struct nilfs_btree *btree;
1550 struct nilfs_btree_path *path;
1551 int ret;
1552
1553 btree = (struct nilfs_btree *)bmap;
1554 path = nilfs_btree_alloc_path(btree);
1555 if (path == NULL)
1556 return -ENOMEM;
1557 nilfs_btree_init_path(btree, path);
1558
1559 ret = nilfs_btree_do_lookup_last(btree, path, keyp, NULL);
1560
1561 nilfs_btree_clear_path(btree, path);
1562 nilfs_btree_free_path(btree, path);
1563
1564 return ret;
1565 }
1566
1567 static int nilfs_btree_check_delete(struct nilfs_bmap *bmap, __u64 key)
1568 {
1569 struct buffer_head *bh;
1570 struct nilfs_btree *btree;
1571 struct nilfs_btree_node *root, *node;
1572 __u64 maxkey, nextmaxkey;
1573 __u64 ptr;
1574 int nchildren, ret;
1575
1576 btree = (struct nilfs_btree *)bmap;
1577 root = nilfs_btree_get_root(btree);
1578 switch (nilfs_btree_height(btree)) {
1579 case 2:
1580 bh = NULL;
1581 node = root;
1582 break;
1583 case 3:
1584 nchildren = nilfs_btree_node_get_nchildren(btree, root);
1585 if (nchildren > 1)
1586 return 0;
1587 ptr = nilfs_btree_node_get_ptr(btree, root, nchildren - 1);
1588 ret = nilfs_btree_get_block(btree, ptr, &bh);
1589 if (ret < 0)
1590 return ret;
1591 node = (struct nilfs_btree_node *)bh->b_data;
1592 break;
1593 default:
1594 return 0;
1595 }
1596
1597 nchildren = nilfs_btree_node_get_nchildren(btree, node);
1598 maxkey = nilfs_btree_node_get_key(btree, node, nchildren - 1);
1599 nextmaxkey = (nchildren > 1) ?
1600 nilfs_btree_node_get_key(btree, node, nchildren - 2) : 0;
1601 if (bh != NULL)
1602 brelse(bh);
1603
1604 return (maxkey == key) && (nextmaxkey < NILFS_BMAP_LARGE_LOW);
1605 }
1606
1607 static int nilfs_btree_gather_data(struct nilfs_bmap *bmap,
1608 __u64 *keys, __u64 *ptrs, int nitems)
1609 {
1610 struct buffer_head *bh;
1611 struct nilfs_btree *btree;
1612 struct nilfs_btree_node *node, *root;
1613 __le64 *dkeys;
1614 __le64 *dptrs;
1615 __u64 ptr;
1616 int nchildren, i, ret;
1617
1618 btree = (struct nilfs_btree *)bmap;
1619 root = nilfs_btree_get_root(btree);
1620 switch (nilfs_btree_height(btree)) {
1621 case 2:
1622 bh = NULL;
1623 node = root;
1624 break;
1625 case 3:
1626 nchildren = nilfs_btree_node_get_nchildren(btree, root);
1627 WARN_ON(nchildren > 1);
1628 ptr = nilfs_btree_node_get_ptr(btree, root, nchildren - 1);
1629 ret = nilfs_btree_get_block(btree, ptr, &bh);
1630 if (ret < 0)
1631 return ret;
1632 node = (struct nilfs_btree_node *)bh->b_data;
1633 break;
1634 default:
1635 node = NULL;
1636 return -EINVAL;
1637 }
1638
1639 nchildren = nilfs_btree_node_get_nchildren(btree, node);
1640 if (nchildren < nitems)
1641 nitems = nchildren;
1642 dkeys = nilfs_btree_node_dkeys(btree, node);
1643 dptrs = nilfs_btree_node_dptrs(btree, node);
1644 for (i = 0; i < nitems; i++) {
1645 keys[i] = nilfs_bmap_dkey_to_key(dkeys[i]);
1646 ptrs[i] = nilfs_bmap_dptr_to_ptr(dptrs[i]);
1647 }
1648
1649 if (bh != NULL)
1650 brelse(bh);
1651
1652 return nitems;
1653 }
1654
1655 static int
1656 nilfs_btree_prepare_convert_and_insert(struct nilfs_bmap *bmap, __u64 key,
1657 union nilfs_bmap_ptr_req *dreq,
1658 union nilfs_bmap_ptr_req *nreq,
1659 struct buffer_head **bhp,
1660 struct nilfs_bmap_stats *stats)
1661 {
1662 struct buffer_head *bh;
1663 struct nilfs_btree *btree;
1664 int ret;
1665
1666 btree = (struct nilfs_btree *)bmap;
1667 stats->bs_nblocks = 0;
1668
1669 /* for data */
1670 /* cannot find near ptr */
1671 if (NILFS_BMAP_USE_VBN(bmap))
1672 dreq->bpr_ptr = nilfs_btree_find_target_v(btree, NULL, key);
1673
1674 ret = nilfs_bmap_prepare_alloc_ptr(bmap, dreq);
1675 if (ret < 0)
1676 return ret;
1677
1678 *bhp = NULL;
1679 stats->bs_nblocks++;
1680 if (nreq != NULL) {
1681 nreq->bpr_ptr = dreq->bpr_ptr + 1;
1682 ret = nilfs_bmap_prepare_alloc_ptr(bmap, nreq);
1683 if (ret < 0)
1684 goto err_out_dreq;
1685
1686 ret = nilfs_btree_get_new_block(btree, nreq->bpr_ptr, &bh);
1687 if (ret < 0)
1688 goto err_out_nreq;
1689
1690 *bhp = bh;
1691 stats->bs_nblocks++;
1692 }
1693
1694 /* success */
1695 return 0;
1696
1697 /* error */
1698 err_out_nreq:
1699 nilfs_bmap_abort_alloc_ptr(bmap, nreq);
1700 err_out_dreq:
1701 nilfs_bmap_abort_alloc_ptr(bmap, dreq);
1702 stats->bs_nblocks = 0;
1703 return ret;
1704
1705 }
1706
1707 static void
1708 nilfs_btree_commit_convert_and_insert(struct nilfs_bmap *bmap,
1709 __u64 key, __u64 ptr,
1710 const __u64 *keys, const __u64 *ptrs,
1711 int n,
1712 union nilfs_bmap_ptr_req *dreq,
1713 union nilfs_bmap_ptr_req *nreq,
1714 struct buffer_head *bh)
1715 {
1716 struct nilfs_btree *btree;
1717 struct nilfs_btree_node *node;
1718 __u64 tmpptr;
1719
1720 /* free resources */
1721 if (bmap->b_ops->bop_clear != NULL)
1722 bmap->b_ops->bop_clear(bmap);
1723
1724 /* ptr must be a pointer to a buffer head. */
1725 set_buffer_nilfs_volatile((struct buffer_head *)((unsigned long)ptr));
1726
1727 /* convert and insert */
1728 btree = (struct nilfs_btree *)bmap;
1729 nilfs_btree_init(bmap);
1730 if (nreq != NULL) {
1731 nilfs_bmap_commit_alloc_ptr(bmap, dreq);
1732 nilfs_bmap_commit_alloc_ptr(bmap, nreq);
1733
1734 /* create child node at level 1 */
1735 lock_buffer(bh);
1736 node = (struct nilfs_btree_node *)bh->b_data;
1737 nilfs_btree_node_init(btree, node, 0, 1, n, keys, ptrs);
1738 nilfs_btree_node_insert(btree, node,
1739 key, dreq->bpr_ptr, n);
1740 if (!buffer_dirty(bh))
1741 nilfs_btnode_mark_dirty(bh);
1742 if (!nilfs_bmap_dirty(bmap))
1743 nilfs_bmap_set_dirty(bmap);
1744
1745 unlock_buffer(bh);
1746 brelse(bh);
1747
1748 /* create root node at level 2 */
1749 node = nilfs_btree_get_root(btree);
1750 tmpptr = nreq->bpr_ptr;
1751 nilfs_btree_node_init(btree, node, NILFS_BTREE_NODE_ROOT,
1752 2, 1, &keys[0], &tmpptr);
1753 } else {
1754 nilfs_bmap_commit_alloc_ptr(bmap, dreq);
1755
1756 /* create root node at level 1 */
1757 node = nilfs_btree_get_root(btree);
1758 nilfs_btree_node_init(btree, node, NILFS_BTREE_NODE_ROOT,
1759 1, n, keys, ptrs);
1760 nilfs_btree_node_insert(btree, node,
1761 key, dreq->bpr_ptr, n);
1762 if (!nilfs_bmap_dirty(bmap))
1763 nilfs_bmap_set_dirty(bmap);
1764 }
1765
1766 if (NILFS_BMAP_USE_VBN(bmap))
1767 nilfs_btree_set_target_v(btree, key, dreq->bpr_ptr);
1768 }
1769
1770 /**
1771 * nilfs_btree_convert_and_insert -
1772 * @bmap:
1773 * @key:
1774 * @ptr:
1775 * @keys:
1776 * @ptrs:
1777 * @n:
1778 */
1779 int nilfs_btree_convert_and_insert(struct nilfs_bmap *bmap,
1780 __u64 key, __u64 ptr,
1781 const __u64 *keys, const __u64 *ptrs, int n)
1782 {
1783 struct buffer_head *bh;
1784 union nilfs_bmap_ptr_req dreq, nreq, *di, *ni;
1785 struct nilfs_bmap_stats stats;
1786 int ret;
1787
1788 if (n + 1 <= NILFS_BTREE_ROOT_NCHILDREN_MAX) {
1789 di = &dreq;
1790 ni = NULL;
1791 } else if ((n + 1) <= NILFS_BTREE_NODE_NCHILDREN_MAX(
1792 1 << bmap->b_inode->i_blkbits)) {
1793 di = &dreq;
1794 ni = &nreq;
1795 } else {
1796 di = NULL;
1797 ni = NULL;
1798 BUG();
1799 }
1800
1801 ret = nilfs_btree_prepare_convert_and_insert(bmap, key, di, ni, &bh,
1802 &stats);
1803 if (ret < 0)
1804 return ret;
1805 nilfs_btree_commit_convert_and_insert(bmap, key, ptr, keys, ptrs, n,
1806 di, ni, bh);
1807 nilfs_bmap_add_blocks(bmap, stats.bs_nblocks);
1808 return 0;
1809 }
1810
1811 static int nilfs_btree_propagate_p(struct nilfs_btree *btree,
1812 struct nilfs_btree_path *path,
1813 int level,
1814 struct buffer_head *bh)
1815 {
1816 while ((++level < nilfs_btree_height(btree) - 1) &&
1817 !buffer_dirty(path[level].bp_bh))
1818 nilfs_btnode_mark_dirty(path[level].bp_bh);
1819
1820 return 0;
1821 }
1822
1823 static int nilfs_btree_prepare_update_v(struct nilfs_btree *btree,
1824 struct nilfs_btree_path *path,
1825 int level)
1826 {
1827 struct nilfs_btree_node *parent;
1828 int ret;
1829
1830 parent = nilfs_btree_get_node(btree, path, level + 1);
1831 path[level].bp_oldreq.bpr_ptr =
1832 nilfs_btree_node_get_ptr(btree, parent,
1833 path[level + 1].bp_index);
1834 path[level].bp_newreq.bpr_ptr = path[level].bp_oldreq.bpr_ptr + 1;
1835 ret = nilfs_bmap_prepare_update_v(&btree->bt_bmap,
1836 &path[level].bp_oldreq,
1837 &path[level].bp_newreq);
1838 if (ret < 0)
1839 return ret;
1840
1841 if (buffer_nilfs_node(path[level].bp_bh)) {
1842 path[level].bp_ctxt.oldkey = path[level].bp_oldreq.bpr_ptr;
1843 path[level].bp_ctxt.newkey = path[level].bp_newreq.bpr_ptr;
1844 path[level].bp_ctxt.bh = path[level].bp_bh;
1845 ret = nilfs_btnode_prepare_change_key(
1846 &NILFS_BMAP_I(&btree->bt_bmap)->i_btnode_cache,
1847 &path[level].bp_ctxt);
1848 if (ret < 0) {
1849 nilfs_bmap_abort_update_v(&btree->bt_bmap,
1850 &path[level].bp_oldreq,
1851 &path[level].bp_newreq);
1852 return ret;
1853 }
1854 }
1855
1856 return 0;
1857 }
1858
1859 static void nilfs_btree_commit_update_v(struct nilfs_btree *btree,
1860 struct nilfs_btree_path *path,
1861 int level)
1862 {
1863 struct nilfs_btree_node *parent;
1864
1865 nilfs_bmap_commit_update_v(&btree->bt_bmap,
1866 &path[level].bp_oldreq,
1867 &path[level].bp_newreq);
1868
1869 if (buffer_nilfs_node(path[level].bp_bh)) {
1870 nilfs_btnode_commit_change_key(
1871 &NILFS_BMAP_I(&btree->bt_bmap)->i_btnode_cache,
1872 &path[level].bp_ctxt);
1873 path[level].bp_bh = path[level].bp_ctxt.bh;
1874 }
1875 set_buffer_nilfs_volatile(path[level].bp_bh);
1876
1877 parent = nilfs_btree_get_node(btree, path, level + 1);
1878 nilfs_btree_node_set_ptr(btree, parent, path[level + 1].bp_index,
1879 path[level].bp_newreq.bpr_ptr);
1880 }
1881
1882 static void nilfs_btree_abort_update_v(struct nilfs_btree *btree,
1883 struct nilfs_btree_path *path,
1884 int level)
1885 {
1886 nilfs_bmap_abort_update_v(&btree->bt_bmap,
1887 &path[level].bp_oldreq,
1888 &path[level].bp_newreq);
1889 if (buffer_nilfs_node(path[level].bp_bh))
1890 nilfs_btnode_abort_change_key(
1891 &NILFS_BMAP_I(&btree->bt_bmap)->i_btnode_cache,
1892 &path[level].bp_ctxt);
1893 }
1894
1895 static int nilfs_btree_prepare_propagate_v(struct nilfs_btree *btree,
1896 struct nilfs_btree_path *path,
1897 int minlevel,
1898 int *maxlevelp)
1899 {
1900 int level, ret;
1901
1902 level = minlevel;
1903 if (!buffer_nilfs_volatile(path[level].bp_bh)) {
1904 ret = nilfs_btree_prepare_update_v(btree, path, level);
1905 if (ret < 0)
1906 return ret;
1907 }
1908 while ((++level < nilfs_btree_height(btree) - 1) &&
1909 !buffer_dirty(path[level].bp_bh)) {
1910
1911 WARN_ON(buffer_nilfs_volatile(path[level].bp_bh));
1912 ret = nilfs_btree_prepare_update_v(btree, path, level);
1913 if (ret < 0)
1914 goto out;
1915 }
1916
1917 /* success */
1918 *maxlevelp = level - 1;
1919 return 0;
1920
1921 /* error */
1922 out:
1923 while (--level > minlevel)
1924 nilfs_btree_abort_update_v(btree, path, level);
1925 if (!buffer_nilfs_volatile(path[level].bp_bh))
1926 nilfs_btree_abort_update_v(btree, path, level);
1927 return ret;
1928 }
1929
1930 static void nilfs_btree_commit_propagate_v(struct nilfs_btree *btree,
1931 struct nilfs_btree_path *path,
1932 int minlevel,
1933 int maxlevel,
1934 struct buffer_head *bh)
1935 {
1936 int level;
1937
1938 if (!buffer_nilfs_volatile(path[minlevel].bp_bh))
1939 nilfs_btree_commit_update_v(btree, path, minlevel);
1940
1941 for (level = minlevel + 1; level <= maxlevel; level++)
1942 nilfs_btree_commit_update_v(btree, path, level);
1943 }
1944
1945 static int nilfs_btree_propagate_v(struct nilfs_btree *btree,
1946 struct nilfs_btree_path *path,
1947 int level,
1948 struct buffer_head *bh)
1949 {
1950 int maxlevel, ret;
1951 struct nilfs_btree_node *parent;
1952 __u64 ptr;
1953
1954 get_bh(bh);
1955 path[level].bp_bh = bh;
1956 ret = nilfs_btree_prepare_propagate_v(btree, path, level, &maxlevel);
1957 if (ret < 0)
1958 goto out;
1959
1960 if (buffer_nilfs_volatile(path[level].bp_bh)) {
1961 parent = nilfs_btree_get_node(btree, path, level + 1);
1962 ptr = nilfs_btree_node_get_ptr(btree, parent,
1963 path[level + 1].bp_index);
1964 ret = nilfs_bmap_mark_dirty(&btree->bt_bmap, ptr);
1965 if (ret < 0)
1966 goto out;
1967 }
1968
1969 nilfs_btree_commit_propagate_v(btree, path, level, maxlevel, bh);
1970
1971 out:
1972 brelse(path[level].bp_bh);
1973 path[level].bp_bh = NULL;
1974 return ret;
1975 }
1976
1977 static int nilfs_btree_propagate(const struct nilfs_bmap *bmap,
1978 struct buffer_head *bh)
1979 {
1980 struct nilfs_btree *btree;
1981 struct nilfs_btree_path *path;
1982 struct nilfs_btree_node *node;
1983 __u64 key;
1984 int level, ret;
1985
1986 WARN_ON(!buffer_dirty(bh));
1987
1988 btree = (struct nilfs_btree *)bmap;
1989 path = nilfs_btree_alloc_path(btree);
1990 if (path == NULL)
1991 return -ENOMEM;
1992 nilfs_btree_init_path(btree, path);
1993
1994 if (buffer_nilfs_node(bh)) {
1995 node = (struct nilfs_btree_node *)bh->b_data;
1996 key = nilfs_btree_node_get_key(btree, node, 0);
1997 level = nilfs_btree_node_get_level(btree, node);
1998 } else {
1999 key = nilfs_bmap_data_get_key(bmap, bh);
2000 level = NILFS_BTREE_LEVEL_DATA;
2001 }
2002
2003 ret = nilfs_btree_do_lookup(btree, path, key, NULL, level + 1);
2004 if (ret < 0) {
2005 if (unlikely(ret == -ENOENT))
2006 printk(KERN_CRIT "%s: key = %llu, level == %d\n",
2007 __func__, (unsigned long long)key, level);
2008 goto out;
2009 }
2010
2011 ret = NILFS_BMAP_USE_VBN(bmap) ?
2012 nilfs_btree_propagate_v(btree, path, level, bh) :
2013 nilfs_btree_propagate_p(btree, path, level, bh);
2014
2015 out:
2016 nilfs_btree_clear_path(btree, path);
2017 nilfs_btree_free_path(btree, path);
2018
2019 return ret;
2020 }
2021
2022 static int nilfs_btree_propagate_gc(const struct nilfs_bmap *bmap,
2023 struct buffer_head *bh)
2024 {
2025 return nilfs_bmap_mark_dirty(bmap, bh->b_blocknr);
2026 }
2027
2028 static void nilfs_btree_add_dirty_buffer(struct nilfs_btree *btree,
2029 struct list_head *lists,
2030 struct buffer_head *bh)
2031 {
2032 struct list_head *head;
2033 struct buffer_head *cbh;
2034 struct nilfs_btree_node *node, *cnode;
2035 __u64 key, ckey;
2036 int level;
2037
2038 get_bh(bh);
2039 node = (struct nilfs_btree_node *)bh->b_data;
2040 key = nilfs_btree_node_get_key(btree, node, 0);
2041 level = nilfs_btree_node_get_level(btree, node);
2042 list_for_each(head, &lists[level]) {
2043 cbh = list_entry(head, struct buffer_head, b_assoc_buffers);
2044 cnode = (struct nilfs_btree_node *)cbh->b_data;
2045 ckey = nilfs_btree_node_get_key(btree, cnode, 0);
2046 if (key < ckey)
2047 break;
2048 }
2049 list_add_tail(&bh->b_assoc_buffers, head);
2050 }
2051
2052 static void nilfs_btree_lookup_dirty_buffers(struct nilfs_bmap *bmap,
2053 struct list_head *listp)
2054 {
2055 struct nilfs_btree *btree = (struct nilfs_btree *)bmap;
2056 struct address_space *btcache = &NILFS_BMAP_I(bmap)->i_btnode_cache;
2057 struct list_head lists[NILFS_BTREE_LEVEL_MAX];
2058 struct pagevec pvec;
2059 struct buffer_head *bh, *head;
2060 pgoff_t index = 0;
2061 int level, i;
2062
2063 for (level = NILFS_BTREE_LEVEL_NODE_MIN;
2064 level < NILFS_BTREE_LEVEL_MAX;
2065 level++)
2066 INIT_LIST_HEAD(&lists[level]);
2067
2068 pagevec_init(&pvec, 0);
2069
2070 while (pagevec_lookup_tag(&pvec, btcache, &index, PAGECACHE_TAG_DIRTY,
2071 PAGEVEC_SIZE)) {
2072 for (i = 0; i < pagevec_count(&pvec); i++) {
2073 bh = head = page_buffers(pvec.pages[i]);
2074 do {
2075 if (buffer_dirty(bh))
2076 nilfs_btree_add_dirty_buffer(btree,
2077 lists, bh);
2078 } while ((bh = bh->b_this_page) != head);
2079 }
2080 pagevec_release(&pvec);
2081 cond_resched();
2082 }
2083
2084 for (level = NILFS_BTREE_LEVEL_NODE_MIN;
2085 level < NILFS_BTREE_LEVEL_MAX;
2086 level++)
2087 list_splice(&lists[level], listp->prev);
2088 }
2089
2090 static int nilfs_btree_assign_p(struct nilfs_btree *btree,
2091 struct nilfs_btree_path *path,
2092 int level,
2093 struct buffer_head **bh,
2094 sector_t blocknr,
2095 union nilfs_binfo *binfo)
2096 {
2097 struct nilfs_btree_node *parent;
2098 __u64 key;
2099 __u64 ptr;
2100 int ret;
2101
2102 parent = nilfs_btree_get_node(btree, path, level + 1);
2103 ptr = nilfs_btree_node_get_ptr(btree, parent,
2104 path[level + 1].bp_index);
2105 if (buffer_nilfs_node(*bh)) {
2106 path[level].bp_ctxt.oldkey = ptr;
2107 path[level].bp_ctxt.newkey = blocknr;
2108 path[level].bp_ctxt.bh = *bh;
2109 ret = nilfs_btnode_prepare_change_key(
2110 &NILFS_BMAP_I(&btree->bt_bmap)->i_btnode_cache,
2111 &path[level].bp_ctxt);
2112 if (ret < 0)
2113 return ret;
2114 nilfs_btnode_commit_change_key(
2115 &NILFS_BMAP_I(&btree->bt_bmap)->i_btnode_cache,
2116 &path[level].bp_ctxt);
2117 *bh = path[level].bp_ctxt.bh;
2118 }
2119
2120 nilfs_btree_node_set_ptr(btree, parent,
2121 path[level + 1].bp_index, blocknr);
2122
2123 key = nilfs_btree_node_get_key(btree, parent,
2124 path[level + 1].bp_index);
2125 /* on-disk format */
2126 binfo->bi_dat.bi_blkoff = nilfs_bmap_key_to_dkey(key);
2127 binfo->bi_dat.bi_level = level;
2128
2129 return 0;
2130 }
2131
2132 static int nilfs_btree_assign_v(struct nilfs_btree *btree,
2133 struct nilfs_btree_path *path,
2134 int level,
2135 struct buffer_head **bh,
2136 sector_t blocknr,
2137 union nilfs_binfo *binfo)
2138 {
2139 struct nilfs_btree_node *parent;
2140 __u64 key;
2141 __u64 ptr;
2142 union nilfs_bmap_ptr_req req;
2143 int ret;
2144
2145 parent = nilfs_btree_get_node(btree, path, level + 1);
2146 ptr = nilfs_btree_node_get_ptr(btree, parent,
2147 path[level + 1].bp_index);
2148 req.bpr_ptr = ptr;
2149 ret = nilfs_bmap_start_v(&btree->bt_bmap, &req, blocknr);
2150 if (unlikely(ret < 0))
2151 return ret;
2152
2153 key = nilfs_btree_node_get_key(btree, parent,
2154 path[level + 1].bp_index);
2155 /* on-disk format */
2156 binfo->bi_v.bi_vblocknr = nilfs_bmap_ptr_to_dptr(ptr);
2157 binfo->bi_v.bi_blkoff = nilfs_bmap_key_to_dkey(key);
2158
2159 return 0;
2160 }
2161
2162 static int nilfs_btree_assign(struct nilfs_bmap *bmap,
2163 struct buffer_head **bh,
2164 sector_t blocknr,
2165 union nilfs_binfo *binfo)
2166 {
2167 struct nilfs_btree *btree;
2168 struct nilfs_btree_path *path;
2169 struct nilfs_btree_node *node;
2170 __u64 key;
2171 int level, ret;
2172
2173 btree = (struct nilfs_btree *)bmap;
2174 path = nilfs_btree_alloc_path(btree);
2175 if (path == NULL)
2176 return -ENOMEM;
2177 nilfs_btree_init_path(btree, path);
2178
2179 if (buffer_nilfs_node(*bh)) {
2180 node = (struct nilfs_btree_node *)(*bh)->b_data;
2181 key = nilfs_btree_node_get_key(btree, node, 0);
2182 level = nilfs_btree_node_get_level(btree, node);
2183 } else {
2184 key = nilfs_bmap_data_get_key(bmap, *bh);
2185 level = NILFS_BTREE_LEVEL_DATA;
2186 }
2187
2188 ret = nilfs_btree_do_lookup(btree, path, key, NULL, level + 1);
2189 if (ret < 0) {
2190 WARN_ON(ret == -ENOENT);
2191 goto out;
2192 }
2193
2194 ret = NILFS_BMAP_USE_VBN(bmap) ?
2195 nilfs_btree_assign_v(btree, path, level, bh, blocknr, binfo) :
2196 nilfs_btree_assign_p(btree, path, level, bh, blocknr, binfo);
2197
2198 out:
2199 nilfs_btree_clear_path(btree, path);
2200 nilfs_btree_free_path(btree, path);
2201
2202 return ret;
2203 }
2204
2205 static int nilfs_btree_assign_gc(struct nilfs_bmap *bmap,
2206 struct buffer_head **bh,
2207 sector_t blocknr,
2208 union nilfs_binfo *binfo)
2209 {
2210 struct nilfs_btree *btree;
2211 struct nilfs_btree_node *node;
2212 __u64 key;
2213 int ret;
2214
2215 btree = (struct nilfs_btree *)bmap;
2216 ret = nilfs_bmap_move_v(bmap, (*bh)->b_blocknr, blocknr);
2217 if (ret < 0)
2218 return ret;
2219
2220 if (buffer_nilfs_node(*bh)) {
2221 node = (struct nilfs_btree_node *)(*bh)->b_data;
2222 key = nilfs_btree_node_get_key(btree, node, 0);
2223 } else
2224 key = nilfs_bmap_data_get_key(bmap, *bh);
2225
2226 /* on-disk format */
2227 binfo->bi_v.bi_vblocknr = cpu_to_le64((*bh)->b_blocknr);
2228 binfo->bi_v.bi_blkoff = nilfs_bmap_key_to_dkey(key);
2229
2230 return 0;
2231 }
2232
2233 static int nilfs_btree_mark(struct nilfs_bmap *bmap, __u64 key, int level)
2234 {
2235 struct buffer_head *bh;
2236 struct nilfs_btree *btree;
2237 struct nilfs_btree_path *path;
2238 __u64 ptr;
2239 int ret;
2240
2241 btree = (struct nilfs_btree *)bmap;
2242 path = nilfs_btree_alloc_path(btree);
2243 if (path == NULL)
2244 return -ENOMEM;
2245 nilfs_btree_init_path(btree, path);
2246
2247 ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level + 1);
2248 if (ret < 0) {
2249 WARN_ON(ret == -ENOENT);
2250 goto out;
2251 }
2252 ret = nilfs_btree_get_block(btree, ptr, &bh);
2253 if (ret < 0) {
2254 WARN_ON(ret == -ENOENT);
2255 goto out;
2256 }
2257
2258 if (!buffer_dirty(bh))
2259 nilfs_btnode_mark_dirty(bh);
2260 brelse(bh);
2261 if (!nilfs_bmap_dirty(&btree->bt_bmap))
2262 nilfs_bmap_set_dirty(&btree->bt_bmap);
2263
2264 out:
2265 nilfs_btree_clear_path(btree, path);
2266 nilfs_btree_free_path(btree, path);
2267 return ret;
2268 }
2269
2270 static const struct nilfs_bmap_operations nilfs_btree_ops = {
2271 .bop_lookup = nilfs_btree_lookup,
2272 .bop_lookup_contig = nilfs_btree_lookup_contig,
2273 .bop_insert = nilfs_btree_insert,
2274 .bop_delete = nilfs_btree_delete,
2275 .bop_clear = NULL,
2276
2277 .bop_propagate = nilfs_btree_propagate,
2278
2279 .bop_lookup_dirty_buffers = nilfs_btree_lookup_dirty_buffers,
2280
2281 .bop_assign = nilfs_btree_assign,
2282 .bop_mark = nilfs_btree_mark,
2283
2284 .bop_last_key = nilfs_btree_last_key,
2285 .bop_check_insert = NULL,
2286 .bop_check_delete = nilfs_btree_check_delete,
2287 .bop_gather_data = nilfs_btree_gather_data,
2288 };
2289
2290 static const struct nilfs_bmap_operations nilfs_btree_ops_gc = {
2291 .bop_lookup = NULL,
2292 .bop_lookup_contig = NULL,
2293 .bop_insert = NULL,
2294 .bop_delete = NULL,
2295 .bop_clear = NULL,
2296
2297 .bop_propagate = nilfs_btree_propagate_gc,
2298
2299 .bop_lookup_dirty_buffers = nilfs_btree_lookup_dirty_buffers,
2300
2301 .bop_assign = nilfs_btree_assign_gc,
2302 .bop_mark = NULL,
2303
2304 .bop_last_key = NULL,
2305 .bop_check_insert = NULL,
2306 .bop_check_delete = NULL,
2307 .bop_gather_data = NULL,
2308 };
2309
2310 int nilfs_btree_init(struct nilfs_bmap *bmap)
2311 {
2312 bmap->b_ops = &nilfs_btree_ops;
2313 return 0;
2314 }
2315
2316 void nilfs_btree_init_gc(struct nilfs_bmap *bmap)
2317 {
2318 bmap->b_ops = &nilfs_btree_ops_gc;
2319 }
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